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A  TEXT-BOOK 


OF 


PHYSIOLOGY 


BY 

M.  FIOSTER,  M.A.,  M.D.,  LL.D.,  F.R.S., 

rtt'-FnritjK  ov  i-hysiotouy  in  toe  i'mvkfwtv  ok  CAiiEHinGE,  and  rEUX>w  «f  trinity 


FOURTH  AMERICAN, 

FK>>M  THE  ni-TH  ESIil.ISH  EI>IT1I>S,  THORIIUGHLV  REVISED,  WITU  NOTES,  ADDITIONS, 
AND  TWO  HINDKED  ANIl  EKiHTV-TWIi  ILU'STKATIONP, 


I'HILADKLPHIA: 

LEA    KROTIIERS    &    CO., 

18iH. 

•1 


PREFACE  TO   PART  I. 


Ih  the  preaent  ediUoo  I  have  made  oonridenble  chuiges  and  addition! ; 
bat  in  the  changes  I  have  tried  to  nudntain  the  cbaiw^er  of  the  book  as 
{weaented  in  in«yioiu  edition! ;  and  the  additions,  with  the  ezoefAion  of 
tbe  histological  paragraphs,  are  oaosed  not  by  any  attempt  to  add  new 
matter  or  to  enlarge  the  goural  soc^  of  the  work,  but  by  an  efibrt  to 
•zplain  more  fdWj  and  at  greater  length  what  seem  to  me  to  be  the  most 
fbndamental  and  most  important  topics.  I  hare  beoi  led  to  introdnce 
some  bistolopcal  stiUements,  not  with  uie  view  of  in  any  way  relieving 
tbe  stndent  from  tbe  neoeaity  nf  sbidying  distinct  histolc^ical  treatises, 
bat  in  Older  to  bring  him  to  the  phyuologjcal  problem  with  the  histological 
data  fresh  in  bis  mind.  I  have  therefim  dealt  very  briefly  with  the 
several  histological  points  and  confined  myself  to  matters  having  a  physio- - 
logical  bearing.  Hy  friends.  Dr.  Gaskell,  Mr.  Langley,  and  Dr.  Lea,  have 
given  me  great  assistance  throughout,  and  their  names  might  fitly  appear 
on  the  title-page,  were  it  not  that  the  present  arrangement  makes  me  alone 
responsible  for  all  shortcomings.  I  have  also  to  thank  my  senior  demon- 
strator, Mr.  L.  E.  Shore,  M.B.,  and  my  junior  demonstrator,  Mr.  Wing- 
field,  M.A.,  for  much  valuable  aid.  The  second  and  third  parts  will  follow 
this  first  part  as  soon  as  possible.  . 


PREFACE   TO   PART   III. 


I  AM  of  course  aware  of  the  disad vantages  of  issuing  this  edition  of  my 
Text-boot  in  instalments,  and  very  much  regret  that  this  part  does  not 
complete  the  work.  The  failure  to  get  the  whole  of  the  remainder  ready 
has  been  due  to  lack,  not  of  will,  but  of  ability  and  opportunity. 

I  take  this  opportunity  of  thanking  my  friend.  Dr.  Gowers,  for  the  loan 
of  two  woodcuts,  as  well  as  for  much  valuable  advice.  Throughout  the 
whole  of  this  part  I  have  been  largely  assisted  by  my  colleague,  Mr. 
Langley,  and  by  my  friend  aud  former  pupil.  Dr.  Sherrington.  The 
latter,  besides  helping  me  with  criticisms,  has  prepared  for  me  most  of  the 
figures  after  original  drawings  by  himself  What  little  merit  there  may 
be  in  this  part  is  largely  due  to  these  two  gentlemen. 

M.  FOSTER. 

CiMBKiDcm,  September,  ISflO. 


AMERICAN  PUBLISHERS'   NOTICE. 


Thb  Mtthor's  pn&oeB  to  the  eeveral  parte,  in  which  this  edition  was 
imied  in  fiogland,  will  show  how  thorough  has  l>eeQ  the  revision  to  which 
H  hw  beeo  Bafajected.  Tlie  task  of  the  Amerioan  editor  has,  therefore, 
bean  mostly  coofined  to  the  adaptation  of  the  work  to  the  wonts  of  the 
Asmioaa  stad^t,  Among  the  principal  additions  will  be  found  refer- 
eooee  to  the  phyriolo^cal  action  of  some  of  the  more  important  drags, 
and  the  test  has  been  elucidated  bj  an  increased  number  of  illustra- 
tioais.  All  matter  thns  introdaoed  has  been  distinguished  hy  inolosure  in 
bnckets  [— ]. 

Pb  1 1.1  DELPHI  A,  October.  ISSI. 


CONTENTS. 


PAGE 

ISTFOprCTlOX .33 


BOOK    I. 

BL'Hip.    THE  TISSUES  OF  MOVEMKNT.    THE  VABCILAR  MECIIAKISM. 


CHATTER    I. 
BLOOD. 

The  Clotting  of  Blood -ii 

The  ( "onmscles  of  the  Blood :  The  Red  Corpuscles -H 

The  W'liile  or  (itolorless  CorjmscleB Ill 

Hl.xxi  PlateletH 68 

Tin- '  'heniicul  Compoeiiion  of  Blo<id KO 

Tlie  ijiiiinlit^  of  Blood,  and  itn  Distribution  in  the  Body    .        .        .        .  Tl 

CHAFTKK    II. 
THE  a>STRACTILE  TIPf-UES. 

The  Phenomena  of  Miiwcle  and  Nerve :  Muscular  and  Nervous  Irritability  73 

The  I'henometia  of  u  Simple  Miiacuiur  Ponlrflftion f^'i 

Tetanii;  l.'ontrHctiona 'J1 

*  In  the  Chanpw  which  Take  I'hicv  in  a  Muscle  Dnringii  ('mitriiction:  The 

t  'han^e  in  Form      ...........  94 

The  i  'heraiatrv  of  Muscle 1U4 

Thermal  Changes Ill 

Klt-ctrical  Chaiijres 113 

The  ("hanger  in  ii  Nerve  during  the  I'lumiige  of  a  Nerviin^  Jjnjiulsc  .UN 

The  Nature  of  (he  Changes  through  which  an   Electric  i  urrciil  is  Able  to 

(ienerate  a  Nervoun  Imiiulw:   Action  of  the  Conwlant  Current  .!:;■< 

The  Muaele-nerve  Preparation  aa  a  Miichiiie I3,i 


X  CONTENTS. 

rAi;y. 
The  Circu instances  which  DeCermiDe  the  Degree  of  Irritability  of  Muscles 

and  Nerves 140 

The  Energy  of  Muscle  and  Nerve,  and  the  Nature  of  Muscular  and  Nervous 

Action I4<) 

On  Some  Other  FormH  oC  Contractile  TiMue:  Plain,  Smooth  or  Unstriated 

Muscular  Tissue 149 

Ciliary  Movement  .....                  154 

Amceboid  Moveinenta 157 


CHAPTER   III, 
GENERAL  FE.\TUEEH  OF  NERVOUS  TISSUES.         .     IW 


CHAPTER    IV. 
THE  VASCULAR   .MICCHANISM. 


The  Structure  and  Main  Featuresof  the  Vascular  Apparatus  ,  17.'! 

The  Structure  of  Arteries,  Capillaries,  and  Veins 173 

The  Main  Features  of  the  Apparatus 18!i 

The  Main  Facts  of  the  Circulation 184 

Hydraulic  Principles  of  the  Circulation 193 

Circumstances  Determining  the  Rate  of  the  Flow 199 

The  Heart a06 

The  Phenomena  of  the  Normal  Beat 20<i 

Endocardiac  Prmsure 213 

Summar; :]24 

The  Work  Done 22."> 

The  Pulse 22G 

The  Regulation  and  .Adaptation  of  the  Vascular  Mechanism  :  The  Regula- 
tion of  the  Beat  of  the  Heart 240 

The  Histology  of  the  Heart 241 

The  Development  of  the  Normal  Beat 24-"i 

The  Government  of  Heart-beat  by  the  Nervous  System       ....  2.';J 

Other  luliuenceg  Regulating  or  Modifying  the  Beat  of  the  Heart       .        .  2<>:! 

Changes  in  the  Calibre  of  the  Minute  Arteriex.    Vasomotor  Actions  .        .  26-~> 

The  tkiursc  of  Vaao- constrictor  and  Vasodilator  Fibres      ....  27:! 

The  Effects  of  Vanomolor  Actions 27.') 

Vasomotor  Functions  of  the  Central  Nervous  System  .....  27i! 

The  Capillary  Circiiluti'in 2.S(> 

Changes  in  the  t^uiintiiy  of  Blood 291 

A  Ueview  of  Some  of  the  Features  of  the  Circulation  ....  292 


CONTEXTS.  xi 


BOOK    II. 

THE  TISSDE3  OF  CHEMICAL  ACTION  WITH  THEIR  RE3PECTIVE 
MECHANISMS.    KUTBITIOX. 


CHAPTER    I. 
THE  TLSSUES  AND  MECHANISMS  OF  DIGESTION. 

FAQE 

The  Oharactera  and  Properties  of  Salira  aad  Gastric  Juice:  Saliva    .        .  302 

<  raatric  Juice 307 

The  tilriicture  of  tlie  Salivary  Gland«,  ihe  Gastric  JIueoua  Membrane,  the 

I'kDcreas,  and  the  CEsophagus ''IT 

The  Siructure  of  the  Stomach 319 

The  .'■alivary  Glands ^^^ 

The  I'aDcTeaa 328 

The  Structure  of  Ihe  (£«o]>h&gus 330 

The  Act  of  Secretion  of  Saliva  aod  Gastric  Juice  and  the  Nervous  Meelian- 

i^mt  which  Hegulate  it 332 

The  Changes  in  a  Gland  Constituting  the  Act  of  Secretion  ,  ,  .  339 
The   rroperties  anil   OharacteM  of   Bile,  Pancreatic    Juice    and   Succus 

KntericUH 351 

Itile :«! 

I'auiTe.itii;  Juice 3.54 

."■iiccus  Kntericus   ,...,.-...■■  358 

Tlie  Secreiiim  of  Pancreatic  Juice  and  of  Bile    ......  3o9 

The  Structure  of  the  Intestines:  The  Small  Inleatine           ....  365 

Tiie  Lar^ce  Intestine 3i4 

The  Muwular  Mcchanisni!>  of  Di^jestioii 375 

Tb.'  Changes  which  the  Food  I'ndergoet  in  the  .Vlinientary  Canal              .  3W 

The  (.'hnnges  in  the  Stomavh ■*'*■' 

In  the  Small  InteHtine ■'«! 

Ill  the  Large  Intestine   .......-■■  39;) 

Till-  Fei-ew 3!''> 

The  Lacteal)!  and  the  Lymphatic  Syntt-ni 31Nj 

The  Lyriipliatic  Veiwels '■'•*' 

Lymph  ciipil la rie.* '■'■'•'' 

TI»'.'=trnctureof  Lympliaiictilunds -1"- 

The  Nature  and  MovenieiitM  of  Lymph  (Irirhidirig  Chyle)  .                            -  -1'"* 

The  Chnratters  of  Lymph ^"'■^ 

Tlip  Movemt-nta  of  Lympli ^ll 

.\li-iirptiiin  from  the  .Uimeiil:Lry  Canal 419 

Tin- CoumeTalien  l>y  the  Several  I'roiluct.-*  of  Hige-tLiiu      ....  IIH 

The  Slechani^ni  of  Ahsiirptiori -I-'* 


Xn  CONTENTS. 

CHAPTER    II. 

RESPIRATION. 

The  Structure  of  the  Lungs  and  Broucbiul  PMssagen 4:11 

The  Mechanics  of  PulmoQiiry  Res gii  ration 43K 

The  Respiratory  Movements -i*-* 

Changes  of  the  Air  in  Respiration 44!> 

The  Respiratory  Changes  in  the  BiooU *)I 

The  Relations  of  0:cygen  in  the  Blood 4-35 

Products  of  the  Decomposition  of  Haemoglobin 4I>3 

The  Relations  of  the  Carbonic  Acid  in  the  Blood 4)iii 

The  Relations  ot  the  Nitrogen  in  the  Bloi>d 4ti7 

The  Resjjiratory  Changes  in  the  Lungs :  The  Entrance  of  Oiygen     .        .  4Gr 

ThcEititof  Carbonic  Acid 470 

The  Respiratory  Changes  in  the  Tissues 471 

The  Nervous  Mecbaniam  of  Respiration 475 

The  Effects  of  Changes  in  the  Composition   and  Pressure  of  the  Air 

Breathed 402 

The  Relations  of  the  Respiratory  System   to  the  Vascular  and  Olher 

Systems .        .' 496 

Modified  Respiratory  Jfovements ■"•"O 

CHAPTER    III. 
THE  ELIMINATION  OF  WASTE   PRODUCT^*, 

The  Structure  of  the  Kidney .  ■'ill 

The  Composition  and  Characters  of  Urine '>24 

AmountH  of  the  Several   Urinary  Constituents   Passed  in  Twenty-four 

hours.    (After  Parkes.) -J2S 

The  .Secretion  of  Urine '>29 

Secretion  of  the  Renal  Epithelium 't^i' 

The  Discharge  of  Urine ■'>46 

Micturition '>48 

The  Structure  of  the  Skin V)] 

The  Nature  and  Amount  of  Perspiration      .......  'iW 

Cutaneous  Respiration .IliO 

The  Mechanism  of  the  Secretion  of  Sweat .'•112 


CHAPTER  IV. 

THE  METABOLIC  PROCESSK-;  OF  THE   HODY. 

The  Structure  of  the  Liver .'•(i-'i 

The  History  of  tilyc'ipeu 'iT'.i 

Diabetes ■'•^'- 


CONTENTS.  Xlli 

PAUI 

The  S{ile«n TiSS 

The  FDrmation  of  the  Conatitueats  of  Bile 595 

On  Urea  and  on  Nitrogenous  Metabolisin  in  Ueneral 599 

On  i*onie  Structures  and  FroceeneH  of  Obscure  Nature        ....  607 

The  History  of  Fat.     Adipose  Tissue 614 

The  Mkmmary  Uland 620 

Avt-rage  Com poei lion  of  Milli  in  Diflerent  AnimnU 624 


CHAPTER     V. 
XUTRITION. 

The  fftatlstics  of  Nutrition 628 

(.'o[n]iiiriBon  of  Income  and  Output  of  Material 630 

The  Enerpy  uf  tlie  llody:  Tbe  Income  of  Energy 637 

The  Expenditure 638 

Animal  Heat 641 

On  Nutrition  iu  General 662 

«>n  Diet 660 


BOOK    III. 

TilK  TESTRAL    SERVOf.S   SYSTK-M    AND    ITS    INSTRrMKNTS. 

CHAPTER    I. 

THE  piIMXAL  CORD. 

( *u  Slime  Features  of  the  Spinal  Neries  671 

The  ."Structure  iif  the  ."Spinal  ( Vird 676 

The  Reflei  Actions  of  the  I^piiial  Cord 711 

The  -Autumatic  .Vctions  of  the  Spinal  C'ird 724 

CIlAI'TKH     11. 

THE    ItKAIX. 

t >ri  S(.me  General  Featurex  of  tliv  Slnutiirr  of  the  Brain    ....  731 

The  itulh  7;!(i 

The  lJis|>osition  and  Oonneciiipii-  <>!'  tin'  Oriiv  and  White  .Mutter  <>(  the 

Ilrain:  Theliray  llatler T4'< 


XIT  CONTENTS. 

The  Central  Gray  Matter  and  the  Nuclei  of  the  Cranial  Nerves  .  748 

The  Superficial  Grny  Matter 762 

The  Intermediate  Gray  Mailer  of  the  Crural  System 762 

Other  Collections  of  Gray  Matter 772 

The  Arrangement  of  the  Fibres  of  the  Brain 774 

Longitudinal  Fibres  of  the  Pedal  Sytitem 775 

Longitudinal  Fibres  of  the  Tegmental  System 778 

Tranarerse  or  so-called  Commissural  Fibres 781 

Summary 782 

On  the  Phenomena  Exhibited  by  an  Animal  Deprived  of  its  Cerebral 

Hemispheres T>^4 

The  Machinery  of  Coordinated  Movements 790 

On  Some  Histological  Features  of  the  Brain 79^ 

The  Superficial  Gray  Matter  of  the  Cerebellum 800 

The  Cerebral  Cortex 803 

On  Voluntary  Movements 808 

On  the  Development  within  the  Central  Nervous  System  of  Visual  and  of 

some  Other  Sensations :  Visual  Sensations 83ti 

Sensations  of  Smell 847 

Sensations  of  Taste 8o() 

Sensations  of  Hearing S-'iO 

On  the  Development  of  Cutaneous  and  some  Other  Sensations   .  S'>I 

Some  Other  Aspects  of  the  Functions  of  the  Brain K6''i 

On  the  Time  taken  up  by  Cerebral  Operations 873 

The  Lymphatic  Arrangements  of  the  Brain  and  Spinal  Cord      .  676 

The  Vascular  Arrangeinenls  of  the  Brain  and  Spinal  Cord  ....  881 


CHAPTER    in. 

SIGHT. 

Pbysiolc^ical  Anatomy  of  the  Eye 887 

Dioptric  Mechanisms:  The  Formation  of  the  Image 894 

Accommodation S'J^'i 

Imperfections  in  the  Dioptric  Apparatua 90.'> 

Visual  Sensations 908 

The  Origin  of  Visual  Impulses 909 

Simple  SenaatioDs 'Jl."> 

Color  Sensations 918 

Visual  Perceptionii 9L'-% 

Modified  Perceptions 927 

Binofuiar  Vision  :  Corresponding  or  Identical  Points 9;it) 

Movements  of  the  Eyeballs 9:W 

The  Horopter 9:i4 

Visual  Judgments 934 

The  Protected  Mechiinisma  of  the  Eve 9:!7 


C0XTENT3,  XV 

CHAPTER    IV. 

HEARiNO,  SMELL,  AND  TASTE. 

lleurin);;   I'hjsiott^icHl  Anatomy  of  the  Enr                 939 

The  AcnuHtti'  ApparalU"         ...                                     ....  946 

Au<]itory  ^nxAtiniis       ....                         ,                ...  94S 

Auditury  ,Iuclginetit« !iri2 

SiufU:  rb.vsiulogicsl  Anatomy  of  (be  Nasal  Fusiia! 9.'>3 

Tafte  :  I'hjBiologicai  Anatomy  of  the  Gustatory  Mucous  Membran*^           .  !>M 

C'lIAPTEIt    \. 

FEELING    AND  TOL'fH, 

■  ieneriil  Sensibility  and  Tactile  Perceptions 960 

Tnctilf  Sensations :  SeasHtions  of  Prew'Ure Dtil 

.-^f  niuitii)nB  of  Temperature 9(>2 

Tactile  PerceptionH  and  Judgmcnr^ 9t!4 

The  Muscular  Sense 966 

CHATTKR    A' I. 
SPECIAL   MUSCULAR   MECHANiyMS. 

TheVoiie;  The  Pliysiologlca)  Anatamy  of  llii- Larynx       .                           .  fHiS 

Sjieech ;  Vowelii                        .....  974 

l.Vmmtnaiils      ....  97^1 

I.oconiiitur  Mf('hu^il^mB                                                                                   .  977 


BOOK     IV. 

THE  Tlss^■^:.<5  ,\si>  mechasisms  or  HEritcun'mox. 

(.11  APTKi;     I. 
UlUiANS  (H-  KEl'imiin  TKIN. 
Tlie  I'hT!'ii)logiciil  .\ii»tiifny  of  ilie  "rpirm 'irdeniTutioii .  9S2 

CllA  I'TKi;     1  I. 

MENsrillATHiN     .  .      us? 


XVI  CONTENTS. 


CHAPTER    III 


PACE 

IMPREGXATION 991) 


UHAPTKR    lY. 
THE  NITRITION   OF  THE   EMBRYO  .  .      WT 

CHAPTER     V. 

PARTIRITIOS nm 

rHAPTEU    VI. 
THE   PHAGES  OF  I.IFE  .     J'"*'. 

CHAPTER    VII. 

DEATH  .     1013 

A  P  P  K  X  D I  X . 
THE  CHEMICAL  BA:?IS  OF  THE  ANIMAL  lODY        .     lOL". 


A  TEXT-BOOK  or  rilVSIOUHiY. 


I 


I 


INTRODUCTION. 


|L  Dnurriox,  aM«l  l)f  tuIcroMoptcal  examination,  IcitobM  us  ihat 
Iba  bodr  of  uuui  is  vamt\«  un  >i(  c*^riain  kiiiiltt  uf  uauHftl,  «»  ilifli^ring  Anm 
Mch  niMf  In  uptical  iio'l  oilier  |ili)'*ir'itl  oliuractora  ami  *o  built  up  logCtlMtr 
a»  lo  gift  ibt  body  cvrbiin  olructural  fmturM.  Clii-iiiiunI  I'xaininntioD 
flutbtr  UMba  IM  UuU  iIkw  IciiKlo  i>f  nuit'-rinl  nn-  r4iiii)Hi«n)  of  various 
dMBlical  aubOAnOM,*  largr  niiriitwr  tif  iihicli  liitvi?  lliiM  vliitnuumti'' thnt 
Ibftjr  |M«MB  •  CDtuidArable  luiiutiDl  ol'  pvlvutial  vficrgy  <:iii>iiblo  of  Imidk  mI 
frw.  fmiUTtd  actual,  by  oxi'Iittion  or  Kitno  other  dM-micnl  cluingc.  Thus 
ibr  bndj,  u  a  whuk-.  may.  fmm  a  cbemtciil  point  of  viow,  Ira  ct)usidorod  as 
■  u*m  of  various  cht^micml  substADflM,  rpprawnling  altogether  a  oonsidora- 
bU  capital  of  {Mtential  energy. 

iS.  Tbb  Inxly  rnny  exisl  fith<-r  tis  a  living  body  or  (for  n  certain  time 
■1  tSBSl)  as  a  dead  body,  and  the  living  l>ody  may  at  any  time  booome  a 
dMd  body.  At  what  is  geoerallv  calle<l  the  moment  of  death  (Itut  arlifi- 
eUly  to,  for  as  we  aliafl  see  t^e  processes  of  death  are  numeroiia  and 
gnHMnl)  tbe  dead  body  so  fkr  as  structure  and  chemicnl  romiMiaition  an 
CBdOCrasd  >•  esceedbgly  like  the  living  biMly  ;  indevl  the  dittVri-im;*  b«- 
tWMn  iba  two  are  Hicb  us  can  Iw  deuruiined  unly  by  vi-Ty  carofnl  i'i«niiaa- 
tiao.  six)  are  ritll  tit  a  largi'  I'xlcnt  estimated  by  drawing  infrivncoi  rnlhor 
actually  <>Wrveil.  At  any  rate  the  dead  l»Hly  at  llii>  luonieiit  of  death 
ibla  thi-  living  body  id  hu  fur  an  it  rcpnveoUa  GUfNtal  of  potential 
Pront  tliat  mofncot  ouwsnl.  hnwovrr,  the  cnptMl  is  expended ;  by 
vbich  nn-  Inrp'ly  i!u.w  of  oxidiiiirin,  ihc  ttoi.-rKy  i"  gnidoslly  dis- 
aipBlad,  leaviDg  the  Iwdy  chii-tly  i»  tlie  form  of  heal.  While  thc»e  ohomical 
[wwcBMM  atw  going  on  Uio  structural  features  disappsar,  and  the  btxty,  witb 
tbm  ln«  nf  nearly  all  ittfenergr,  if  «i  hut  rasolv«d  into  "dust  and  aahoe." 

Tfao  tiharacterislic  of  the  dead  bixly  then  is  that.  Iwing  n  maw  of  sub- 
■laaciv  of  coDiidcrable  polcnlial  eaergr,  it  0  always  more  or  tern  elowly 
{■lag  seergT,  never  gaining  energy ;  ibe  capital  of  energy  preecnt  nt  the 
■ooMit  of  oMtb  is  more  or  less  slowly  diminishod,  m  never  increased  or 

|3.  When  on  tli«  ntfaer  band  we  study  a  living  body  wo  ar«  struck  witb 
ibc  fullowinj^  Ntlicnl  fads : 

1.  Tbe  living  body  moves  of  iUelf.  cither  moving  one  part  of  the  body 
on  a04itber  or  raoviug  tbe  whole  body  frtm   [iloce  lo  place.     These  utov*- 

arc  active;  llie  biidy  in  not  (iiniply  pulled  or  pushed  by  external 
lann,  but  i1m>  motive  powfr  id  in  the  body  itself,  tbe  energy  of  each  more- 
nsttl  i*  supplieil  by  tbe  budr  it»elf. 

2.  TbflK  niovtrnuiits  uo  OetnrmitKil  and  inSnenocd,  indeed  often  sewn  to 
slan4<l,  by  duugM  in  the  surronndintpi  of  the  body.    iSuddeu  contact 

the  sur&oo  of  tb*  b"dv  and  wme  foreign  oliject  will  often  call 

8 


IKTBODWOTIO!*. 


fortli  n  nifivcciipiit.  Tb«  body  is  wosilive  to  chonxen  iu  iu  surroun<  _  . 
arKl  tlii;  fcnniLivi-iK-H  u  iDaDifceud  uoi  only  by  niovenictila  tmi  by  OtStt 
choDgcs  in  thn  boctr. 

3.  Il  is  contintiiillr  gtroerftting  heat  and  giving  out  bent  losurrouiidiii); 
things,  the  produdioii  nixl  Ium  of  ht-nl,  m  lh«  vnbw  ol'  nimi  uod  ci^rtniit 
oilier  aDimslR,  being  to  ii<iju>l<(l  Omt  lliv  uliulti  burly  i«  wurm,  tliul  t*  of  ■ 
l€iui«rtiiurc  Iiiglior  thiiti  tliut  ot  KUrroiiodiiig  ihitigit. 

4.  From  lime  to  time  It  cnU,  thm  is  to  «ty  tnlc<:i  into  itself  supplies  of 
ccrtnio  eubnlntices  known  m  fooil,  ihvm  sutMlmici-s  boiiig  in  lliv  moin  rirailnr 
to  that  which  compoee  Iho  buity,  itni]  bi-ing  ]ik<-  ihcm  dicmicfll  bodiiv  of 
OODBldeniblfi  potential  energy,  cnpnblc  tbrougli  oxiiljilion  or  other  chemiciil 
cbangee  of  setting  free  n  considcntble  (luunlily  of  energy. 

5.  h  is  continually  brenllilng,  that  is,  Inking  in  from  the  surrounding  air 
supplies  of  osygcu. 

6.  It  is  continually,  or  from  time  to  lime,  discharging  from  itself  into  ile 
turroundings  eo-called  waste  matters,  which  waete  matters  mny  be  broadly 
described  as  products  of  oxidation  of  the  substances  taken  in  as  food,  or  of 
ihv  tiubstances  c'omjKiBing  the  body. 

Heuce  the  liviuj;  body  maybeaaid  to  hedistin^ished  from  the  dead  body 
by  liircb  main  features. 

The  living  hoily  like  the  dead  is  continually  losing  energy  (and  lonng  it 
more  rapidly  than  ibe  dead  body,  the  si>ecial  breathing  arrangements  jier- 
nitting  a  m«re  rapid  oxidation  of  its  sulistanee),  but  unlike  the  dead  Ixxly 
is  by  loeana  of  fond  continually  restoring  its  substance  and  replenishing  its 
store  of  energy. 

The  energy  set  free  in  the  dead  body  by  the  oxidation  and  other  chemical 
changes  of  its  tiibslance  leaves  tlie  body  almost  exclusively  in  tbe  form  of 
beat,  nberens  ci  great  deal  of  energy  leave*  (ho  living  body  as  mechanical 
work,  the  result  of  various  movements  of  the  body,  and  as  ne  shall  see  a 
gre«t  deal  of  the  energy  which  ultimately  leaves  tlie  t>o<ly  ns  heiit,  exists  for 
a  while  iriibin  tbe  living  body  in  other  ibrms  than  heal,  though  eventually 
trsnnformed  into  heat. 

The  cbaogea  in  the  surrounding  aflect  the  body  at  a  slow  rale  and  in  a 
general  way  only,  simply  letKomg  or  increasing  the  amount  or  rate  of 
cheivical  change  and  the  quantity  of  beat  thereby  fct  free,  but  never 
diverting  the  energy  into  fuaie  olher  form  such  ns  that  of  movement; 
vhereai  changes  in  tbe  surroundings  may  in  the  case  of  the  living  body 
npidlv,  profoundly,  and  in  special  wava  affect  not  only  the  amount  but  also 
tbe  kind  of  ener^  set  free.    The  dead  body  leH  to  itself  slowly  fiUls  lo 

Eiccra.  slowly  dissipates  its  store  of  energy,  and  slowlv  give«  out  beat;  a 
igber  or  lower  leniperuturc,  more  or  len  moisture,  a  free  or  scanty  supply 
of  oxygen,  the  advenl  of  many  or  few  putrefkctive  organitunH,  tb't«e  may 
auicken  or  xlack^n  the  rate  ut  ublcb  energy  is  being  tli.-elpaied  but  do  not 
diveH  that  energy  from  heat  into  motion  ;  whereas  in  the  living  l>udy  so 
slight  a  change  of  surroundingn  oa  the  mere  touch  by  n  bair  of  some  par- 
turn  lu*  turfacVi  may  so  aflect  the  setting  fixe  of  energy  as  to  lead  to  such  a 
disdMlf^  of  mergv  in  tbe  furm  of  movemi^nt  that  the  previously  appar- 
ently quiescent  bcHly  may  be  suddenly  thrown  into  tbe  mo»t  violent  oouvul- 
sion». 

The  difference,  therdbre.  between  living  snljslantT  and  dead  sulislnnce 
though  recondite  arc  very  great,  and  the  ultimate  object  of  pbysiulogy 
b  to  ascertain  how  it  is  that  living  substiincc  c«n  do  what  dnid  sub- 
stance cannot,  can  renew  its  substanoe,  and  leiilcnish  the  energy  which  it  is 
cvnliuually  loeing,  and  can,  according  to  the  nature  of  its  surroundings, 
vary  not  only  tbe  amount  but  also  the  kind  of  energy  which  it  sets  free. 


J 


INTlIOItCCTIOX. 


35 


Thw  ihtrr  oiT  two  gmt  (livtuon*  of  ph^Klalggv  :  uoc  having  to  ilo  nitli  the 
nBM««l  of  MbMaoM  wu)  tho  rojtU-tnuhinvnt  or  oicrgy.  tbo  Uher  having  to 
de  with  th«  Mttiiig  Art  of  «Dorg}-. 

14,  Now  thtr  body  "f  nmu  (or  oih-  oI'  iIh-  hi):tirr  iLnininU)  in  n  very  d^ni- 
piMstvil  ■trucluiv.  cuii«i#tiiij;  ol'  ilitli-mil  kiixU  oC  i)iali'ri«l,  which  nv  call 
litamm,  Mirh  le  innsculur,  i»rvifii«,  (iMiin^ocivo,  nnd  cho  likv,  variuuMly 
amspd  in  organs  snrh  lu  hwirl.  1iii)g«.  mutclpe,  «kin.  vtc,  all  built  up  i<i 
fern  UM  bud^  awoMin);  l<i  o-naiii  nn'riiliol'igimi  Iswh.  But  all  this  vum 
pUoatioo,  though  lulvautngt'oug  and  indeed  nccvesary  Tor  ihu  fulkr  lifts  of 
ia  oeL  taKUtial  lo  the  existcnvo  of  life.     Th«  amwha  (Fig.  1]  is  a 

(Fw  I. 


I 


a«»rtnmiMa»ii»lnilllfcWial>iniiH]u».c)— nuil  br  ■■MwmiiuilmU.I 

bctoj;  il  ran^WM  its  Mibdnnce,  rvpVni»h«9i  il«  fivro  of  encrf-y,  and 
eaergjr  now  in  one  form,  now  in  unolli^r;  and  yet  tho  »m(Bba  may 
he  <•■>]  ti)  hare  no  (ueunt  and  no  orgnni! ;  al  nil  cvx'nt«  Ihis  is  true  of  cliiaely 
alltnl  Uui  not  ft  well  known  simpU'  b«ings.  U*int;  iho  more  fHniiltar 
maaaln  aa  a  lyp<^.  and.  lbcr«fori.>,  leaving  on  one  Fide  ihc  nucleua.  and  aor 
ifclllii  linn  between  enduurc  nud  eclcKin-,  wv  may  say  that  iu  Imly  W 
boataceaMUB  in  thf  aeoac  (hat  if  we  divided  it  inio  small  piecea,  each  pleoe 
vmtlalM!  lik«  all  the  nthera.  In  another  sense  it  is  not  bomoffeaeoua.  For 
wa  knn**  (bat  the  amioba  T««eivee  into  its  sulwiaut.'e  inateriu  m*  fuod,  and 
tk*i  thu  frxid  or  part  of  it  reruaius  lodged  in  the  body,  unul  it  is  made  um 
of  and  liuilt  up  iul^t  ibe  living  substance  of  the  Itodj,  and  each  niece  of  the 
Bvios  Mibatancr  «f  the  body  mum  have  in  or  near  it  some  of  the  material 
«Ud  tt  ••  al>»ut  to  build  up  into  itaelf.  Further,  we  know  (hat  ihe  aniwha 
^vw  PUl  watte  mattvra  mcfa  a«  carbttnic  acid  and  other  subttaiicea,  and  each 

ecc  of  Uio  aiarrtw  lauu  contain  Kiiite  nf  theae  wnate  maUers  abotit  to  be. 
(  not  yat,  iliachatgad  frofo  the  |>iece.  Each  piece  of  ihe  amoeba  will, 
tbatvlhrw,  mntain  ibMO  three  Ihinga,  the  actual  living  subalanoe,  the  food 
at-  I"  living  (tibatiiDCo,  and  the  waate  matter*  which  have  eesaed 

U..rftcr,  wv  have  renauno  to  think  (.hnl  the  living  »iib*tanoe  doea  not 
hnak  down  int»  (hv  waMo  mattcm  which  K«ve  ih*!  Imdy  ui  a  dngle  bound. 
iMt  ihara  arc  Mui.'v*  in  (he  d'lnnwiirti  pntgnw  liciwe«n  the  one  aud  the 
•char,  fjimiliirly.  ibongh  uiir  knnwlivlge  mi  rhio  (H)int  in  !<■**  inrv,  we  have 
naaiiri  U>  Ihink  that  ih*?  lnttA  is  not  iDOi>rj>oral<-il  into  (he  livingnbatanco  at 
atio^  tie]!,  but  that  there  arc  Xagea  in  llw  nimard  prngreai  f^om  the 
'  food  to  the  llvinjc  aubatancc.    Each  piece  of  the  body  of  the  am<»bii 


IlfTBODUCTION. 


nil],  Uierofure,  contain  Bubstancoa  npreeeiiting  various  etages  of  becomioK 
liviag,  Bnd  of  oea^iii];  to  be  living,  as  well  as  the  living  substAiice  ilself. 
And  we  may  safely  uinke  ilib  slateiiieiit,  though  we  are  <iuite  uoable  to 
draw  ihc  line,  where  the  dead  foixl  mi  iu  way  up  becomes  living,  or  tbe 
liring  tiibnlaticc  on  iu  way  down  bec<iiuee  dead. 

Sft.  Nor  id  it  nece*iBary  for  our  present  [iur[i<we  In  be  able  to  jioint  out 
under  thv  inicnwrofM;,  or  li>  itotcribe  frurn  ii  bial(>l(i){ii.-«il  )ii)inl  uf  view,  tlie 
part^  nhirh  are  living'  and  llie  purlii  uhicb  an^  dfad  fiiod  nr  drad  wanu. 
jIiv  biHly  of  till-  ani<i;ba  in  rri-<|Ui.''iiliy  sjinki-n  uf  a*  ounMtiling  of  "  jiroto- 
plasm."  Tlie  name  wita  orifiinaH >  given  in  the  niiiUcr  funning  thv  iirimor- 
dial  utricle  of  ihu  v^Mab)*:  fell  n-'  ili»tiu|iii9ln'd  fnim  tlic  d-ll  walfoo  the 
on«  hand,  aud  frum  thn  fluid  c»nt<'nl>  ot  Iha-  oi-ll  or  l-cII  sap  on  die  othrr, 
and  hIho  wo  may  add  t'ntm  the  niicli'ue.  It  ha»  «inco  been  applied  very 
generally  to  Ruch  parlx  of  animal  boiltcs  as  n^cimble.  in  their  general  fea- 
lure«,  tlie  primonlinl  utricle.  Thus  the  l><>dy  of  a  while  blood -corpuscle,  or 
of  a  gland  eell,  or  of  n  nerve  cell,  i*  said  to  consist  of  protoplasm.  8uch 
pans  of  animal  bodies  &;<  do  not  in  their  general  filatures  re^mlile  the 
matter  of  tbe  primordial  utricle  are  not  called  protoplasm,  or,  if  they  at 
•ome  earlier  stage  did  benr  such  resamblance,  but  no  lunger  do  so,  are  some-' 
tiroes,  as  in  the  case  of  the  substance  of  a  muscular  fibre,  called  "diireren- 
lialed  proto[ilflsm."  I'roloplnsm  in  this  sense  Bometimca  appeals,  as  in  tbe 
outer  part  of  most  amceba:.  as  a  luaaa  of  glaesy-lonking  material,  either  con- 
tinuous or  interrupted  by  mure  or  less  spberica]  suaces  or  vaouolen  6lled 
with  Buid,  sometimes  as  in  a  |;land  <%ll  as  a  more  retractive,  cloudy -I  looking, 
or  finely  granular  material  arrau^ed  in  a  more  or  lc«a  irn'gnlar  network,  or 
spnngowork,  the  inier*ticeH  of  which  are  occupied  cither  by  fluid  nr  by  *ame 
material  iliflerent  IVoni  itself.  We  »halt  return,  however,  to  the  fvuturcM  of 
this  "  prulopliwm  "  when  we  conic  to  treat  of  white  blood-corpuscbis  and 
olber  "protoplonmic"  <truclurKL     Mentiwkile  it  is  sufficient  for  our  present 

iturpose  to  note  tliat  lodged  in  the  protoplasm,  discontinuous  with  it,  and 
brmiog  no  part  of  it.  are  in  the  firvt  place  collections  of  fluid,  of  watery 
solutions  of  various  substances,  oci'Upyiog  the  more  regular  vacuoles  or 
the  more  irregular  epaoes  of  the  network,  and  in  tJie  second  place  discrete 
granules  of  one  kind  or  another,  also  forming  no  part  of  tbe  protoploiiu 
iLsvlf,  but  lodged  citbei-  in  the  bars  or  substance  of  the  protoplasm  or  in  the 
vacuoles  or  meshes. 

Now,  there  can  be  little  doubt  that  the  fluids  and  the  discrete  gnmulu  ara 
d*Md  foixl  or  dead  waele.  but  the  present  state  of  our  knowleiTgir  will  not 
permit  us  to  make  any  ver)-  definite  statement  nboul  the  prot«i]ilnsui  it*elf. 
We  may  prubably  cuucludc.  indeed  we  may  be  almii>l  Hunr,  that  pnitnplnsm 
in  the  above  sense  is  uot  all  livinjc  Hubstauce,  that  it  i*  made  up  partly  of 
the  real  living  iiulbtnni'e,  and  partly  of  material  nbieh  n  bovuming  living  or 
luis  cpiUM.-d  Ui  lie  living;  aud  in  the  caa^  wlien^  prtrtuplasm  is  dnoribco  as 
fenniog  a  network,  ii  is  iiiK'>ible  that  some  of  tbu  mnicrial  occuprin^'  the 
mcshm  of  the  notwnrk  may  W,  like  ^rt  of  the  network  itm^ll'.  really  alive. 
"  Pnrtopbism"  in  fact,  »-■•  in  the  nwiio  in  which  wc  arc  now  using  it,  and  shiill 
continue  to  use  it,  i»  a  nwrfihuliMjiml  lerni ;  but  it  tnust  be  iMime  in  mind  that 
llio  same  woni  "protoplasm"  L*  alwi  Irpiiuently  used  to  denote  what  we  have 
just  now  called  "the  rtial  living  sulxrtnnre."  The  word  llien  embodies  a  fihy- 
niologiealidfii;  so  UMil  it  may  Iw  applied  to  the  living  eubittauceof  all  liviOK 
Btnicturre,  whatever  the  microecopicnl  features  of  tboec  Htructures;  in  this 
sense  it  cannot  at  prrcont,  and  piwsibly  never  will  be  recognized  by  the  micro- 
scope, and  onr  knowledge  of  its  nature  must  be  bused  on  iufereooea. 

Keeping  then  to  (he  phrase  "living  subslmiee"  we  may  say  tliat  each 
piece  of  the  body  of  tbe  araai?ba  consists  of  living  substance,  in  which  are 


I 
I 


tXTROnVeTtOK. 


87 


lodnd,  or  wiih  wim-li  nrv  l>uill  uj)  in  mih^  vay  or  utbcr,  food  sod  wnste  in 
TmiVHu  lUgte. 

Now.  M)  ftRioba  nay  divide  itself  into  Iwo,  acb  half  exhibiting  nil  the 
phrBoHMOa  of  lh«  whole;  and  we  caD  easily  imnKine  the  proccM  lu  be 
rHHU«d,  until  the  amatba  was  divided  idIo  b  niuUitudc  of  exceedingly 
Mtaota  aintrbii-,  cat-h  having  aJI  the  properties  of  the  orij;inu).  Hut  it  ia 
slnrioa*,  *■  iu  ihv  like  divisioii  of  a  maea  of  a  clieniical  Hubttuiiee.  that  the 
ditrUoa  owild  ui>t  he  repeated  indctiiiilely.  Just  an  tu  divi«ioi>  uf  the  cbein- 
kal  mtm  we  r<»iuc  to  (he  cWinicul  molecule,  further  divUion  of  which 
ihangw  iIm  pruiwrtiee  of  the  HuhDtnnt^,  *»  ia  Ihe  ooutitiued  divbiun  of  the 
amrrha  we  should  runte  lo  a  aiiae  iu  which  further  diviaioit  interr«re<)  with 
tl  "gicnl  si-li<>»d>.  we  iJimitd  ui>iii«toAphy«ii)lc>;;ifal  unit, curnwjioiid- 

iii.i  ;rv«lly  niun*  couij>lex  ihoo  the  chemical  inoleailc.'     Thid  tinit  lO 

nmain  «  iibyvioliijtical  unit  and  to  conlinne  to  live  muitt  viiniaiu  um  only  a 
pwnluci  of  tltv  livinj;  KuliMaDou  but  alto  the  food  for  that  liviuj^  itulMtance, 
ID  MTtral  at  li<«)4  of  tlw  Mak^.  frum  th*3  iniliid  raw  I'ihhI  up  lt>  ihc  liiml 
**  living"  siiigvB,  and  niuvt  itinnlarlr  contain  variuui  ttaifui  of  wa»tc. 

{  6.  rJow,  ihf-  grwil  cliaraclmMic  of  the  lypicu)  aoHchn  (Icarin^  out  ihc 
BO-'——  '-  that,  ■■  far  ■•  we  mi  ucertnio,  all  the  [>hy»iii]Dgical  unit*  arc 
ml  bU  do  tlH^  «nif  thing*.     Kach  and  every  purt  of  tin-  body 

r*!-.  iif  i—,l  nun  nr  lew  raw  and  builds  it  up  into  iUown  livln);  Kulwtancc ; 
nach  aiul  ttn-ry  part  of  tlw  biKlr  may  bf  nt  oiie  timv  ijuiwcoDt  and  at  another 
in  nntian;  oadi  and  every  part  if  sensilivo  and  rngmnds  by  muvvmeHt  or 
albiniiaB  lo  varioaa  ehangca  in  tls  aitrroundini^. 

Tlte  Wly  of  nun,  in  it>  firet  eta^c,  while  it  in  yet  an  ovum,  if  wc  li^iv« 
•aiiie  the  nucleua  Mtd  Mglet't  ditTerencee  caused  by  ihc  unequal  distribution 
«if  fotal  material  or  yolk,  may  alao  be  raid  to  bo  <mmpoiied  uf  like  parts  or 
like  |4iT*ii>lof:ical  unita. 

Br  tlw  art  nf  MffoneDtatloii,  hiiwevcr,  the  ovum  lit  divided  into  PArLS  or 
e«li*  which  early  aDow  dillurencca  from  each  other;  and  these  diOerenoea 
ra|tidly  iiwreM*  ■•  ctoTelopmeut  proeeeda.  Some  rell*  put  on  certain  ohar- 
metrr'  and  ntlHn  Other  dtanolen— thai  it  to  May.  the  eell«  undergo  hidologi' 
»i  'iallon.     AikI  thit  lakt*  place  in  *iieh  a  way  that  a  number  ol 

eci„  :. ...,:  Kigvlhrr  in  a  group  become  eventually  convened  into  a  Hmha, 
and  Iho  whuk  IhmIv  boeofdM  a  ooltociion  of  such  tiMn<.«  arnntftiil  together 
acmrdio;:  to  morphologtcnl  lawg,  rnich  tiMue  having  a  definite  •tructure.  its 
aallular  nature  Ining  H>mc4iRi<«  proaervcd.  aomatimee  o)wcun-d  or  ev<in  loot. 

Tfaifl  hisiologicikl  <It8e rent iat inn  h  accompanied  by  a  phyawtnt/ienl  divitioH 
tflalor.  Each  tiaane  may  bo  supjmeed  to  Ih?  composed  of  physiologicid  unilM, 
UM  units  of  the  tame  tieeue  being  alike  but  difleriiig  (mm  the  unit*  of  other 
tiaww  ;  and  orrwjmniling  to  ihi^ditrerenceof  «tnictiire,  the  units  of  ditfeniit 
li»»iia  behave  m  act  dilferently.  Instead  of  all  the  units,  as  in  tlie  amo'tigi, 
daiay  iIm<  Kam^  things  e<iually  well,  the  units  of  one  tinuo  are  told  off,  u  it 
m^n,  >'  '  hiu):  eH{<e«ially  well,  or  especially  fully,  and  thus  tho  whola 

labPT'  i>  ii  divided  amonK  tlie  several  tissue*. 

rnl  lissties  may  thu»  be  clnx^itied  according  to  the  work  «hi«li 
ll.' .      '  ' .  and  the  Gnt  great  dUlinciioii  is  into  (1)  the  tinues  wbj«li 

■!•  omovnifd  in  the  wttio);  IVm-  of  ener[.'y  in  sjx-cinl  ways,  and  CI  i  the  tiam«e 
whirh  air  ci>nccnii<d  in  n:pl<-ni>>hin);  tl>e^ub?tan«'alldt)')rvlIening  the  energy 
*f 

1 :.  ,  ivsioloftient  tinSt  nf  tlio  nmivbu  while  it  b  engaged  in  setting  Ave 

*aar|cy  an  a*  to  move  itfflf,  and  hy  rcaum  of  ilv  wnBitivenen  so  directing  that 
flsatiQr  as  Iu  jirtHluce  a  movamtnt  vuiuble  to  ilio  condillous  of  ita  uurround* 

■  Sorli  •  ]ilijik>luK>«l  «nil  miflkl  la  e»\Ui  ■  ttmmntt. 


INTBODUCTIOW. 


ingit,  liANat  th*>  nnme  time  to  t»-jtr  ibc  bibur  nf  uikin^  in  mw  foni],  Qfiiclrctitig 
tliat  pari  «f  the  mw  fmiil  wliioh  Li  ii^criil  mii)  nycfling  thut  which  if  iisclcn, 
and  of  worlciiiK  up  ihc  nccitpti^)  piirl  ihrnugh  n  vnriHv  of  vla^e«  into  It*  onn 
living  sub«litnce — that  U  In  my,  it  hat  nt  tlii;  Minic  lim<?  thnt  it  is  lecling  and 
iDoring  to  currj  on  llio  wurk  of  <ligwting  niid  v«iniilating.  It  has,  more- 
over, at  the  same  time  to  throw  out  tbu  waelo  tnatterv  niifiin);  from  tb« 
changes  inking  ))lum  in  its  own  substiuice,  having  lirsl  bmuglit  l)ief«  waste 
nsttere  into  u  roniiitinn  »iiilnbtc<  for  bdng  thrown  out. 

§  S.  Id  the  body  of  tiiiin.  niovemcnts,  as  we  shall  see,  are,  broadlj  speak- 
li)t(.  parried  nut  by  iiictiii»  of  niiiacnlar  tii>Bue,  and  the  cbaDfee  in  niuscular 
tidaue  which  lead  to  the  setting  free  of  ener)ry  id  ihe  form  of  nioveiuenc  are 
directed),  governed,  and  adapted  lu  the  surrDiiudiuus  of  man.  by  means  of 
nervous  lissuet.  Kays  of  light  fall  on  ilie  uorviitis  liiibataDce  of  the  eye  culled 
Ihe  retina,  and  set  up  iu  the  retina  changes  which  induce  in  the  optic  nerve 
other  rhaiigeH,  wliieli  in  turn  are  propagaled  t»  the  bruiu  as  iifrvnuA  iinpulst*, 
both  the  exdtjiliun  and  the  propa^lioD  involving  an  ex|iem)il.iire  of  enei^. 
Tbcac  nervous  iiupiilaes  reaching  the  brain  may  iudiici-  otlitr  nervous  im- 
pulMi  w'hiob,  travelling  down  ciTtuin  nerv<«  lo  cerinin  nninclvK,  may  lead  to 
change*  in  thoae  rouscW  by  which  they  suddenly  gmw  ^liort  and  pull  upon 
tht  MDO  or  other  structure*  to  which  they  are  attached,  in  which  unae  we 
SDT  the  man  starla ;  or  the  uen'oii*  impulsi-»  rciu'hing  the  brain  may  produce 
soniG  ntlicr  elTbct*.  Similarly  iMiuud  falling  on  the  ciir,  or  contact  uelwecn 
tiie  Hkin  and  snme  t()reign  body,  or  some  change  in  the  nir  or  other  surround* 
tngs  of  the  hodv,  or  Minie  change  wilhin  the  body  it^rlf  may  w)  nflcct  thft 
nervous  tiswie  of  the  iKxIy  that  nervomt  impiilM-s  an  Marlci  and  Inivcl  to 
tbb  point  or  that,  to  thv-  brnin  or  cl»cwh<'rc,  and  evcnlunlly  mny  cither  rcJwh 
•ome  niii-H-uhir  tinuc  and  ko  gira  riM  to  movements,  or  may  reach  Oth 
ti»ues  and  )>r<>iJuce  some  other  eflf^ 

The  muscular  ti«8U0  then  may  be  conndered  as  given  up  to  the  production 
of  muveiuenl,  and  the  nervous  tifeiio  nt  given  up  lo  the  generation,  tranil'or- 
mnttim,  and  propagation  of  nervous  impulses.  In  each  case  there  is  an 
expenditure  of  ener>;y.  which  in  the  ease  of  the  muscle,  as  we  ^ball  see,  leave* 
the  bodv  partly  as  heat,  and  partly  as  work  done,  but  in  the  case  of  nervous 
tlaaiie  is  wholly  or  almost  wholly  transformed  into  heal  before  it  leaves  the 
bodj;  and  thtH  expenditure  necessitates  a  replenishment  of  tatergy  and  a 
lenewid  of  .lulistanoe. 

§  9.  In  onler  thnt  these  master  tissues,  the  nervous  and  miisoutar  tissues,, 
may  carry  oii  their  important  works  to  the  best  wlvauiage.  they  are  relieved 
of  much  of  the  labor  that  falls  upon  each  physiological  unit  of  the  amicba. 
Tfaej  are  not  pre^iited  with  mw  food,  they  are  not  required  to  carry  out  tha 
neonniry  tranifunuutioDS  of  their  immediate  waste  matter*.  TIk  whole  uf 
the  nst  of  the  body  is  engaged  (I)  in  so  preparing  the  mw  fooil.  and  u 
bringing  it  lo  tin*  nervous  and  muscular  tissuw  that  lhe.ie  may  build  it  up 
into  their  own  solmtamv  with  the  least  trouble,  and  (2)  in  receiving  the 
vraste  matters  whiih  arm-  tn  muscular  and  ner\-ous  tismea,  and  preparing 
them  for  rapid  and  easy  eji-cliun  from  the  bmly. 

Thus  to  ocrliiin  liwrno,  nlncb  ne  may  siH-iik  of  bnindly  as  "tiwues 
digestion,"  is  allotted  lh<'  duty  (>f  acting  un  Ine  fiiod  and  pn-puring  it  for  tha 
use  of  the  muscular  and  m-rvouj  tiiuues;  and  to  other  tiiuu<'-'>,  which  wn  maf 
apeak  of  as  "tinaes  of  excretion."  i"  alloiied  the  duty  of  clcnriug  the  bwly 
from  the  waste  mattera  geiicrnlrtl  hy  the  muscular  and  ucn'nn:^  liisucs. 

^  10.  Thew  tisauea  are  for  the  mcnt  part  arrange)]  in  machine  or  rarcban> 
isms  called  organs,  and  the  working  of  ihiawor^ns  tnvii|vi:i>  movement.  The 
maveroeniB  of  then  orgnn«  arc  carried  out,  lilce  the  other  movements  nf  the 
body,  chieflj  by  means  of  muscular  tiaiuc  governed   by  nervous  tissue. 


\ 


I 

ag 


J 


ISTBODCCTTOIT. 

B<f><v  or  may  nixkc  ■  dwliDclion  betireco  tlie  niuscla  wluck  ar«  coDoerued 
in  pfTialdciu);  ■»  elfcci  gii  the  world  ouuitlo  man's  bodj,  the  muBclce  by  wbkh 
MM  il<na  nt«  imrk  io  the  norld,  anil  ilw  nituotei  which  nre  oonoerDod  iu 
snrinK  <Mt  th«  raovemeota  or  the  ioteraa)  orgaiia.  Aiid  we  ma^  atmilarly 
■ako  ■  •litUucLinn  belweeo  tbi-  nervous  tissue  concemeil  in  citrrying  oul  the 
alerokl  work  of  tbe  body  aud  Ibat  coawmed  iu  re^u'ttinK  the  moreineuta 
■ad,  M  we  sbftll  see.  the  general  conduct  of  the  interiiul  ur^is.  But  rheM 
t«o  clawei  uf  muscular  and  nervou*  tiMue  Lh<>U|;h  dUtinct  ui  work,  ami,  lu 
M  shall  see,  ofleti  diflereot  in  structure,  are  nut  nejinnited  or  isolated.  On 
llw  CDDtrary,  while  it  is  the  main  duly  uf  tk«  nervous  tissue  as  a  whole,  the 
wrmw  system,  an  we  may  call  il,  tu  carry  oul,  by  means  of  nervous  impulsus 

raiag  bitber  and  thitlier,  what  may  be  spoken  of  as  llie  work  of  miin.  iirul 
this  aanw  is  tlie  master  linue,  it  abo  serves  as  n  bond  of  union  liiitwiTO 
itwlf  and  th«'  muscka  doing  external  work  on  the  one  hiind,  and  the  organs 
if  digaatioD  or  excretion  on  tlw  olher.  mi  that  (be  iictivily  anil  comlocl  nf 
iW  laurr  may  b>'  iwloquntcly  udiipttd  In  tbi-  iieedii  of  the  former. 

(  U.  I.^utly.  tbe  fiHid  jirepirpd  bikI  i- In  bo  rated  by  the  digestive  urgiuin  is 
arriad  nod  preMnlcd  to  the  musouhir  imd  nervous  titsuea  m  the  form  of  a 
tfMnfdax  fluid  known  as  blood,  whit-h.  driviMi  by  incana  of  a  compIical«d 
ikrrhantsn)  known  a*  tlic  vascular  apleni,  circulatea  all  over  ifae  body,  viitit- 
iuf  in  turn  all  the  tiwuct  of  the  body,  nod  br  a  Kpccial  nrraiiceioont  known 
m  Iba  rwpiralory  Riix-hanism.  carrying  in  itM^lf  to  the  sovvnil  tusum  a  supply 
•f  aiygcn  as  woll  as  of  food  mnro  properly  so  callod. 

Tbn  motive  power  of  this  vascular  system  is  supplied,  as  in  the  case  of  the 
figMtiw  system,  by  means  of  muscular  tiwue.  the  activity  of  which  i*  sinii- 
bnjr  governed  by  the  nervous  syslem,  and  hence  the  lloa- of  blood  to  this 
jtn  or  that  pari  is  rO|i;iilaleil  sccordinK  to  the  n«eds  of  the  pari. 

f  U.  The  above  alii;bt  sketch  will  perhaps  suflice  to  show  not  only  how 
saaieroas  but  how  varied  are  the  problems  with  wliich  physiology  bos  to 
JeaL 

la  ibr  fini  pln<«  there  are  what  mity  be  eallol  jceiienil  problems,  suob  aa 
Uoa  tbr  f  H«l  nltrr  its  preiianiti'iii  and  idulKirntiou  into  bloiul  is  built  up 
isfi  Itic  living  outwtnuce  of  the  several  ItMuc?  How  the  living  sulMtiinoe 
bnaki  down  into  lh«  deail  niiotc?  Huw  the  building  up  and  breaking 
4nm  liithr  in  tbc  diH^ront  tissues  in  such  a  way  that  energy  i«  set  free  in 
dftrvat  mode*,  the  rauscubir  tissue  contracting,  tlie  nervous  timuc  thrilling 
•kb  a  oervotis  im|HiUc,  tbc  secreting  ti»iie  doing  cbeniicnl  work,  and  the 
Eke?  Til  tbaso  eeucnl  4U(»tions  the  an»wcn  which  we  can  nt  present  give 
can  banlly  Im  called  answors  at  all. 

la  the  serond  place  there  nre  what  may  be  called  special  problems,  sueb 
as  What  are  the  various  steps  by  which  the  blood  is  kept  rvplcnishcl  with 
bod  aud  oxygen,  and  kept  free  from  an  occumulalioa  of  ffaat«,  and  how  is 
tbr  anirity  of  the  digwtive.  respiratory,  and  excretory  oigans,  whicli  eJTeot 
Ibta,  rv-ifulsled  and  adapted  to  the  stress  of  drcuntstances?  What  aro  the 
detail*  "f  <be  working  of  tlw  vascnlnr  meclitini^ni  by  which  each  and  every 
IIMM  b  fc««ver  baihed  with  fresh  blDo<l.  and  how  i»  that  working  delicutely 
adaftad  lo  all  the  varied  ebanKes  of  the  bodyT  And,  compared  with  which 
■U  oOwr  special  probleou  are  iu^ik'nitioaut  and  preparatory  only.  How  do 
mnaut  impubes  so  flit  to  and  (r^  within  the  nervous  svstem  aa  to  issue  to 
tbe  movements  which  muke  uii  what  we  aoraelimes  call  tVe  life  of  man?  It 
is  la  ihtve  special  jtrobleni.t  llmt  ne  must  obieily  confine  our  attenttou,  aud 
«•  may  fitly  begin  with  a  study  of  tbc  blood. 


BOOK  r. 


BU»n.    THK  TISSl'ES  OF  MOVDJKNT.    THE  VASCUUR  MtCIIAMSif. 


CHAPTEU   I. 


BLOOD. 


I 


k 


its.  Ttie  wvrnl  linur*  nm  Iriivcnni  bv  inhiuio  tubes,  iIk  c*)iil)arv 
l>loedv«a•cl^  u>  whicb  blood  i*  brought  by  'th«  Mlvrirs,  bik)  frcnn  nhicn 
blood  y  Muriwl  Kiiiiy  by  ilw  veiiw.  Tlww  cntiillnrin'  f«ni>  ncivorka  ilw 
■wfcr*  of  itbich.  rlirU'rins  in  rortii  nnd  riw  in  ibc  diltvn-Hl  ltnuo«.  arc  oceu- 
pM  by  ibr  clrmpiiK  oi  Inc  tJMUO  irhkh  coiweijiJCDlly  liv  mihidf  ih«  Mfnl* 

Tbr  hliHi't  flowing  through  Ihii  cniiillnrin  coiisut*.  under  tiorirml  com)!- 
lioiM,  of  an  uliDoat  «o1orle»  fluid,  tbe  filaiwa,  in  which  are  carried  n  tium- 
btr  «f  bodin,  th«  r*tl,  «nd  the  u-hiu  (x/rfnurtf.  OuiBtde  the  vapillary  wnlls, 
fiKngnpHich  ■[incnoa  exist  beiwceii  the  capillary  valla  and  Ihecelln  or  (ibiee 
sf  Iba  tiKiic,  or  belweeii  tbe  eleuitnis  uf  tbe  tiMue  lh«iiii»elrea,  is  fomiil  ft 
«okir)Ma  fluid,  reAcniblinj;  in  niaoy  m>iN.ft»  ilic  pliuina  of  blood  and  called 
tfmpli.  TliuM  nil  (Kb  elements  uf  th«  tu*uc  and  the  outfidn  of  nil  iht^  nijiil- 
MTW«  arc  li«tlM><)  nilb  lyinjib.  uhirb,  a*  wcslwll  «ce  bcrraftvr.  i*  continimlly 
Aowioir  annr  from  ihc  tlvtic  alonif  i>|Nxial  chaiineU  lo  (MM  into  lymphatic 
VOMela  ami  ihmi-v  iiilo  ibe  blixid. 

As  thr  bliMKl  tliiwR  ihmu^b  ihr  cnpillaripf  certain  ciinfiitunils  of  tbe 
phunin  Mogvlher  wilb,  al  tiium,  nhttc  ixiriniK-le*.  and  under  t'seeiilinDal 
cirruni*lannii  red  c(ir]>itft(rK-« i   pBM    through    tbp   c«|>illnrT   nail    into   the 
lynjih,  and  crrlniu  i:on«liiuciilt>  of  ibr  lymph  pnM  tbruugb  the  mpillwry 
«all  into  ihr  blmwl  Miiliiu  tbe  enpillnry.     Thero  is  ihiie  an  iitlcrehango  uf 
Matirrial  b<'l«i-cii  the  Mood  wilbiu  the  mpiltary  and  the  Irniph  oiil#idc.     A 
•imilar  inli-rchBii^  of  material  if  at  the  Ftiine  (iine  B'^nj;  oti  betweeo  tbe 
Unipb  nuil  tbo  tiMUe  ilwlf     Ueuoe.  by  nicuno  of  the  Tympli  nrting  at  mid- 
atrman,  ■  diwihle  inierehsMKe  uf  maleriiil  takes  place  beineen  lh«  blood 
■itbia  tl»F  nipillary  atid  llie  It^xite  Kiitsi'Ie  the  capillary.     In  every  li»ue, 
•1  bioi;  as  life  lasts  and  the  lili«<il  flows  lhruii|;h  the  bl«<>dveHeli).  a  double 
(■T*«tn.  anw  mpid.  n«u  filowr,  is  |iat»iii);  Irum  the  blood  to  tbe  Ibeue  and 
fmu  ibe  tissue  1»  the  bliHul.     The  sireaiii  IW>ui  the  blood  to  tbe  tusue  car- 
tir*  to  ibe  liMin-  ibr  nial'rinl  nhich  the  tinue  needs  for  buildini;  itf>elf  up 
amt  f'f  iIjiUii;  it.-  work,  iiirtiidiii^'  the  all-imporlani  oxygeu.     The  stream 
fr  :  atue  to  the  btoml  rarrin<  ii>t<i  the  hhiod  t^riain  of  the  products  of 

it.  ...    ......il  cbaiigva  which  havr  b(-('ii  taking'  plaeti  in  iho  luiue,  pnxlurta 

■bkb  mar  he  simple  vtaMe.  to  be  oM  otit  of  the  budv  as  soon  as  powlble, 
•r  which  may  bv  budin  ca{>nble  uf  bfitig  mn<le  txK  at  by  aome  oUier  tisauc 


1/  IH.'i'ili. 

A  iliii'l  Kifiitiii,  ilini  IV'tiu  lli'T  lyififili  lyiii;;  in  tli>r  rhinks  and  craoQiee  of 

III'    li> 1    iil'iHtr   ll'i'   Iv'l'l'   <'liFinrii']4   t<>  tin:   lur(;t;r   l_vm[>b  vessels,  carried 

Mwiiy  li'iiii  llii'  lii'iii'T  >^<ii')i  |iiirlK  'if  ill'!  iiiiiUiriiil  coining  from  the  blood  as 
till  iikJ  iiiti'ii  iiji  liy  till'  lir.'ii''  iiri^ir  iiri'l  Midi  |>iirti^  of  the  material  coming 
tiitiii  ill'  lirn'ii  iiR  il'i  ji'il  liiid  llii-ir  U'li}  itil"  tin:  hloiMlveflsel. 

Ill  tiiii'-i  I iniiii'",  iin  ill  iiiii-i'ji-  fur  inntiuiftf-,  the  capillarv'  network  is  bo 
I  liiwi  ml  iiii'l  ilii'  iiiiini'iiliir  liltrii  li'-M  HO  nimr  to  the  bloodvessel  that  the 
lyiii|ili  liiliv'i'ii  til''  lwoc\i>ilN  onlv  iiM  II  viTy  thin  nheet;  but  in  some  tis- 
BiiKM,  (in  III  iiiiiilii)t<',  ill''  lilci'irlv'iv'-lN  lir  nil  ihu  oiitttide  of  a  large  mass  of 
tlMii".  Ihi'  IiiIi'H'Ijiiiik"  Im'Iwi'ii  the  ri>iilritl  jiiirlH  of  which  and  tne  nearest 

i<ti|'lll'ii  V  I'l Ivcnni'l  in  I'lii-rii'il  'in  throU|;h  a  liin^  stretch  of  lymph  paBsages. 

Mill  III  I'li'li  I'lini'  lliii  iiriiii'i)il>'  in  tlii'  niiik-;  the  tissue,  by  the  help  of  lymph, 
^iii  1  "11  Ihi  l'lii\«l :  iiii'l  nlii'ii  ill  Hiiirifiliiiir  pu^eii  wc  speak  of  changes  oe- 
liiriiii  llii>  liliiiiil  mill  till'  liHNiii'H,  il  will  be  iiiidi'rstoud,  whether  expressly 
al'ili'd  ml  111  ii>i[,  tliiii  llii<  i>hiiii;;ii<  iiri'  cUt'cli-'l  by  moans  iif  the  lymph.  The 
bli'iiil  iiiii\  tliiii  Ih'  ri'fviiiti'il  iiH  1(11  iiilrni-if  iii-'iliiini,  benrtng  the  same  rela- 
Mmin  111  lliii  r.<iiiiili)i'iit  lix.iiK'*  llmt  the  cxlcrniil  miHtium.  the  world,  does  to 
(lii>  »liii|i>  nutitiiliiiil.  .liiM  11^  l1u>  whole  nrj^tiiiiein  lives  on  the  things 
iiixiiiiil  ii,  111  lilt  mill  \i^  I'lHul.  HO  ihi'  si'ViTiil  iiiu>iii>it  livo  on  the  complex  fluid 
lit  uliwli  ilii't  iiiv  nil  liiiihi'il  tiiiil  whii'h  is  Co  ihcm  their  imme«liate  air  and 

( I 

\n  ili<<  ii»uiv>  t  ikt'  M)>  i-wp'ii  iVi'iii  ibi'  bWd  and  fi\t'  up  carbonic  acid 
III  ili>'  l>li-.',l,  biU  iu<<  ii1».t>it  III  ibi-  s.-uiii'  r.iic  or  At  the  $ame  liiue.  More- 
I'v.t  t!i.'  v'M'i^ii  iiwii.s  l.iki'  i!|'  iV-'iii  ilio  li!.hi.i  and  j;ive  up  to  the  bloid 
vi/i.i  .1  ilvivir,  tilings  .'v  liu-  'ii:!!!-  tbitip^  a:  diilVwiit  nttw  or  at  difierent 
ii.'.'i- 

■.\w  ^•■■•c  ::A\:<i.  :h:i:  ti'.o  ivuuv«ii:i->ii  and  ohsrac- 

'"••.\Atr  i.irx;;-;  iv,  .lir^Vrv:;;  -.•arts  ol  tiie  l»iy  and 

:■.•  .-I'u- ■:'.:<."  i.  :.-V.  :\:c  :.::.:ii  ai,i!  a  >f  all  the 

-'■,  s",  •;  ■■.;*■.•..,■(:■■.  a::  .iv:-i_ir  ■-■^::'.r'u  i.''ai>.'eitii>o 

V  ■-■  ».vv  il  s''.:*:'.^,>  «!-. ■..">.  b'.  ■•>i  s  tn.iwn  t>i 

■   .;  ■     '-.■  «,-\trr*'.  ;;**:;>»■-".'.   xj;  "x-   waI:  with 

1  .(■■■.      \;-.i:-  ,■■■.;■    -v.Ut  :  :.t  .-;i*i:i«li:cL     At 

.    ^     ■.  .■,■  ■:.:\-.-.  ■'iJi'.:'>.-i  <:  ;!i  a-^  rn»eat«il 

\.iv     ■■..■  *>„',;;■  .i  i-:j.    ,.-r-:i  :  -  ;i-;  i.amya 

-.^        •  1.1-.  .  "■;  ".■  K  K-.t  7^  -.:'  Z--C  rj)i  ai-.-K  im- 


V 

■,\**"    ;  ■  "H  ', 

*'••*  .'X**.  **:* 

u*  ■• 

.'^i    "    ».   *v 

*.M          •.' 

■.  ■  V",    i"" 

\^     ,A"'l  *■■^ 

■          V« 

,  ■»      ? ' , » ^  ,    ,  ,' 

•-{  ;/  o>    i> 

■■ 

■  -"    **    ■  .*    ," 

'  tv*  ,'        ■     \- 

»            ■        ■ 

._■■    i» 

'  'ilV*l,'^ 

i  ',*     ■    !•  .    1  I.  ■■  ■^■■-  :.■..■"  ;>!»;■»    i'  t       'i^  I'd"  » wrwrtLT 

'  ■           1  .  ^' ,  ^     -s  ■.■          •    x".    ■.■!*.  -Mi;;."  -T-iia  --.-iigm  w 

"•1                            T^                          -   :-»-■  ■■:     .  .                          ••:    \   ;■   .  ■    'l.a*     l'    ll'^i-I    lOtUr 

'-*   ■  •                     -■  '":'      .!«*     :  ■    i::i,'j  r  i-j»  it—a  sded 

--'_■■.                      «  ■                                :■    ,'■       :    ^Hlic  *J.'iiL      I^bi 

<                     .'  ■          -•..:■.  1,;  :    ;    -ii-*ri;l"  suUtKi 

■  ■«.  .   -     .         ..^    -  .^^j.  _       \  ^    i_'     ^ 

_  ,1   ,-.:>?      «s*-.   1  -fci*    iriD* 

-              —             -  -                        ~.--  -      ;    ;:v  -i.:-^*:  -t  rhe 

-    ,  ^       _~     ■■"...-   "?  i>TfcJ-  i  T-uin 

-  .        --  .         .:,  -sa  liT  a-fr^ 

-->:.■-  -.-Tj.  1    ■•■■iC 


TUB   CLOTTIXO    or   BLOOD. 


43 


«r  ArttMam<n/M«i,  flonting  in  n  |i«r(ectU  fluli]  xrruui.  [Pig.  3.]  Th«  thriiikiug 
•ad  owMkoMtiou  of  tbe  clot,  luid  lh«  (virrtvpoiidiiii;  iRoraaM  of  thr  wTiim, 
PMtipM  fiir  aune  tiia&    TIm-  iiivikt  Mirfiui-  of  ihi-  clot  b  g«D«rnll}-  Hli^htly 


[TM.  1 


;»!■.  a, 


>t  dT  (viwnllir  tomoUM  Uaid, 


Unwl  nt  ■BnipiliiU'l  tiluil.  arm  laotrv 
liii<rn.tbawtii(tlwclolccinln«(ilui<ldoM> 
liiK  In  tlH)  ADid  (MVui.    Al)*t  I'lLiulcl 


Me<«va.    A  porUoD  of  lh«  clot  vxamincd  under  t)i«  laionwcopo  ia  MW  (o 

oMMiK  of  «  n-Uwork  of  6n«  gniiiulnr  fibrils,  iu  lti«  niMhw  of  whicb  an 

mtaafUd  tlM'  ml  aii<l  wliiie  ovrpiui'lM  of  the  bloo<l.     la  the  mnim  iiothipg 

(Ml  be  ae«n  but  a  few  stntf  curpui- 

tim.  chiefly  white.    Tbe  MbriU  «ro  l>^"  * 

cnrapoaed    of    a    hi  balance    nllecl 

/kritk.    (Fm.  ■!.]     Ileiicc  we   m»j 

•{M«k  of   ihe  ulot  u  coDakling  of 

Abrin  and  corpusclei;  an)  ibe  act 

of  duUine  Is  obvioaily  a  Buwtitu- 

tm  Ibr  tno  planna  of  AbriD  ami 

arav.  ftillonnj  by  a  acpaimtioo  of 

tbi  fibrin  aiul  «>T|iuaclei  ffura  the 


OnfUtiMd  aiola.  *lM<rti>t  Ik  nbrltteul  mq- 
dMIOB.    AAm  Dauok-J 


^>  Ib  nan,  blow]  when  *b«d  bocninat 
Tiarid  in  about  tww  or  ihn-o  iiiinutut, 
«mI  «Dlrn  tbp  jvlly  tin^}  in  nbiitit 
irvur  ten  minutes.    AOi^r  tlie  lapM 

■  of  anaiher  few  tninuton  the  lint 
ditipi  itf  BcniBi  areeeeD.nnd  dolling 
ii  gUimally  cotunlelc  in  fmin  o4ie  to 
ivmal  boun.     The  (ime,  however. 

■  win  Iw  found  lo  vary  acoarding  lo 
(ireuBMHoceo.  AmoD^  anitnali  tbe 
npidity  uf  duttiug  vanm  excee^ii);;ly  in  iliHerenl  speeixM.  The  blood  of  tbe 
bom  clut4  with  reiDsrkable  alowoeMt;  at)  bIdwIv.  indwd.  that  many  of  the 
rod  and  alw  loDie  of  the  white  corpuscles  (botli  tbeae  being  Bpecifi<'ally 
bearirr  than  the  plasma)  bare  litue  to  Mnk  before  viscidity  aets  iu.  In  con* 
sa^MHim  ihara  ainirmii  nn  tlwsur&oe  of  the  blond  an  up|>er  layer  of  oolorieas 
fhfift.  oMOt^nlng  In  its  dwper  panions  many  c»ii>rl«s9  corpiuclat  (which 
an  lighter  ihnn  the  r*il>.  'lliis  Uycr  rlntu  liki-  t)ic  ntlwr  |«na  iif  the  hlood, 
fcrolnff  th«  »i>'Ciill<vl  "  butTv  I'nai."  A  ainiiliir  butTy  cunt  i*  Mimfitiiucs  Mvn 
ta  thr  bl'--l  of  Minn,  !n  o-riuin  atmurmni  rnuilitiom  ot  tli«  body. 

If  a  [K-ttioii  of  txirwV   hl'Mx)   lie  mimmndcd  by  a  cooling   miilur*  of  Ec* 
aad  mil,  and  thiu  krpt  nt  ntmut  il"  C,  clotting  may  benlmoot  indefiniloly 
puMponoJ.     Under  ih'we  cin-urasluoeo*  n  iu»rt'  oompltM  (lesccut  of  the  cor- 
[WIN  111  takue  pliu-c.  imd  a  oontfalraabK-  iiuiinlity  of  oolorlus  traniparvat 
froe  from  blood  oorjnwpka  may  be  ohlulnetL    A  |mftion   uf  this 


BI.OOP. 


piiumn  rctDOved  fmrn  the  ftvninn  uiUtiire  dnU  tii  tbc  *IUM  manDrr  u  (liit« 
the  vnlirv  Ulo'nl.  It  firal  bcomiat  vim-id  nnil  i1i«d  forma  n  jelly,  which  sub- 
■•qiiOtiUy  M-fiaintfs  into  n  oolorlcM  akruukeit  clot  oui)  acriini.  Tliicahow* 
thnt  iIm)  niriiijuclet  nrc  not  an  caeniial  pitn  nr  the  c1a|. 

It  a  few  cubic  rpntimrircf  of  chi«  oolorltw  plHtiina,  or  ofa  niniiUr  plMma 
which  tnnr  Im'  ohuiiiivd  fnim  nlmwt  nay  blixxl  hy  menm  n'bich  we  will 
pmcntly 'JM^TiliO.  I>c  ililuU-il  with  m«iij- liin«  il«  bulk  of  n  <t.W  per  wni. 
tnluli'Mi  of  Hixliuin  chloride'  clotliiig  i»  much  rcUinliyl,  iiiiil  iho  vnHoiig  stages 
Rutv  Im)  infirv  Muily  wMcbwl.  A»  the  Itiiiil  i*  bivomin^  ricci'l,  lino  fibrils 
of  Alirin  will  b«  Men  to  bo  dovel»|>t.-il  in  il,  cs|*cctully  nt  the  hJc«  of  cbe  con- 
lniniii(,'  vM*al.  As  tiioM  fibril*  multiply  in  iiutnltiT.  the  tloiil  becomes  more 
nn<l  tii'ir>'i>f  (he  i^nsistcncfof  u  jelly  nnd  st  the  Mime  time  somewhat  opaque. 
Klirntl  or  pulh^  nbuut  uitli  n  needle,  the  libril§  shrink  up  into  a  arnall 
o|iiii|iie  Htriogjr  iDlin;  and  n  very  eoDHideruble  bulk  of  the  jelly  may  by 
n};itikliuii  b«  reeolved  into  n  mimite  frnj^menl  of  ■lirunkeii  fibrin  ilotilin);  in  h 
(((lantiiy  of  what  t§  really  diluted  serum.  If  a  Bf>ecimen  of  such  diluted 
plaamn  ho  stirred  I'runi  time  to  time,  as  soon  ua  clotting  begins,  with  a  needle 
or  gliUM  rod,  the  nhriii  may  be  removed  piecemeal  as  it  fornix,  and  the  jelly 
•ta^-  tiiay  he  ult'i^uther  done  away  with.  When  fresh  blood  which  has  not 
yi-t  hnd  time  |i>  clot  U  xlirrwl  ur  whi|i|>eil  with  a  bundle  of  rods  (or  anything 
proMUlinj;  n  InrKu  umotini  ot  ruut;li  aurfaeet,  no  jellydike  clotting  take* 
plaoot  Itiit  till'  mdit  liceomo  covered  with  a  mnsa  of  tikrunketi  fibrin.  Blood 
thiia  whip|>eii  until  lihrin  ccniHW  to  be  deposited,  is  found  to  have  entirely 
\iM  l\M  (lowcr  >)f  cl'itling. 

I'utling  tlie»e  fuels  logollier.  it  i*  very  clear  tlini  th«  phciiomnia  of 
the  clotlini;  of  blood  arc  cnutcd  by  the  apjieurance  in  the  pliwmn  of  fine 
flbrila  of  fibrin.  S<i  hm^  a"  thaw  ar«  «ciuity,  the  bUicKl  i*  ximply  vixoid. 
Wh«U  they  ticcomc  siiHicieiilly  numerous,  they  eiv<-  the  blood  the  firmness 
of  a  j'<Uy.  Soon  nller  ll)eir  rurmnli<ii]  they  Dcgin  to  shrink,  and  while 
shrinkiti);  endow  in  llwir  um»Imw  the  corpu«cle«.  but  squeeze  out  the  fluid 
parts  of  ih»  bItHK).  llenc«  the  appearance  of  the  shrunken  colored  clot  and 
tlw  cidorli<eB  scrum. 

5  13.  Kilirin,  whether  «I>tuit>ed  hy  whipping  freshly  sbed  blood,  or  by 
wiuihiiig  cilhcr  a  uormni  clot,  or  a  clot  obtained  from  oulorleM  piaBtna. 
exhibits  the  Mme  ti^-ncral  cltaractera.  It  beloajn  to  that  olasi  nf  complex 
utMiable  niirDgvDous  btHltrv  railed  protrid*.  wbien  form  a  tarjce  portioD  of  all 
liviiit;  iNMlins  bimI  an  uwntiid  jiaH  of  all  living  stnidurea. 

Our  kmiwlnlge  of  pn>teida  v-  at  pnwent  too  inii>erfecf,  and  pmbahly  nam 
of  thvni  have  yet  Ix'cn  |>n-]Mml  iu  mUijuate  purity  to  justify  in  in  nltemptiiig 
to  Mvun  '■>  lliem  any  drtinilc  fnrmuU ;  but  it  is  imptirtani  to  renieinbet  ibeir 
gtatnu  ci>ii>l>>isiti'>n.  UK)  |iart>  of  a  pn>tetd  enmiaJu  miher  roon-  than  &0 
pans  1^  cnrlxia,  rather  ntun  than  IS  of  ntuugco,  about  7  of  hydragvo,  and 
rather  uorv  than  M  of  oxygen :  that  is  to  ny.  tber  eootain  about  £Uf  their 
wdsrht  of  carboii,  and  uoir  about  i  iMr  w^'glit  t^  nitmgai :  aul  vet,  m  wc 
■ImIi  m«,  tbav  are  emioenuy  lb*  iutn«nious  HibMAucnt  of  ibe  b»dy.  They 
wwllycaM^  aHHtllqitaalirf  (I  orz  per  cvnL)  of  sulphur,  and  manvalso 
h«**  mmt  pkuiplMraa  attariwn  lo  Ibaaa  m  sobm  way  or  other.  When  norot 
Umv  Wra  •  wiaUe  «|aaaUiy  of  aah,  mtMStine  of  inorganic  mite  of  whicb 
iWrh—  MS  cMeir  aoJiwn  and  poOHmtn.  and  tne  ncMe  chiefly  hydrochloric. 

ilwy  all  i^iwcMtain  f«ni.liWM.  by  whicb  their  prMence  may  be  neo^ited ; 
of  tbtw  iW  mtm  tbniafirrirt  ai«  tfae  folloains  :  Bnikil  with  aitnc  and 
ikay  gin  a  yalhw  eUar,  «fckb  iiw|gMa  iaiw  ««<uige  upon  the  ndditiaa  of 


I 
I 

I 


TUB  CI.OTTIXG    OF    BLOOl). 


4A 


■awooim.  Tbil  k  cklted  ihr  xanthitproiiiie  t«st ;  the  color  h  due  lo  a  product 
of  iMunipMJUOn.  Bt^leil  witli  llto  mixture  of  lOPKuric  anil  iiiercurous 
Dimtra  kiiowB  M  Millim't  r'-aynt,  Ihcv  |pvc  n  pink  wlor.  Mixed  nilli  n 
alroaf;  •olmii-n  of  ^ndii-bviinUi- tln-vgivp.  cm  ihr  nddiliun  of  a  dnn>»r  two  (\f 
m  wvy  ««ik  s-dutiuii  of  cuprii'  Hiil|itial(%  n  viokt  or  pink  color  uliiuii  def|M'DK 
oaMUiag.  Tbcw  nn- aniliml  rt-acliunK,  nut  ttir'>uiti):  tuui:)i  if  aor  liubt 
anlbtCUOMilMlioDuf  proU'itU;  bitl  llit-y  nrr  iieclul  as  praclii-al  lr«u  ctinblt'ng 
oa  U>  tiMcct  llii-ir  pmejica. 

TIn  Mvcnl  mrmbon  tif  the  pruidd  group  iiro  at  prmeiit  diRtingtibbod 
Ai^  tadi  tUfaoT  chit'tl^  \ty  thdr  rn>{wctive  aolubilities,  ee[»eciajly  in  viiriuiti 
■tUaa  atlutinna.  Fibnn  i»  one  n{  the  l«uM  enliible ;  it  is  iotoluble  in  wKlvr, 
■JiwMt  insidiiblr  in  dilute  itciilnt)  Hti1in«  solittione,  aud  rerv  npuringlir  wuIiiUb 
IB  nmns  coon-nlrutw)  neiitnil  HiliDc  tototioiis  niid  in  dilule  acide  and  tlkAlwi. 
In  (tniDK  acids  aud  alkaliM  it  diasolrea,  but  in  ibe  procNa  beooiDCi  mn- 
plaUljr  cnaogcd  into  Bomelhio;;  which  is  nu  luiiKer  fibrin.  In  dilute  iicMf  it 
•■■Ik  up  and  l)«<<(>ni«B  trains pArcnt,  but  nben  tbe  acid  ia  neuLratized  rMunia 
Iji  Its  pivTioufl  cunditiuii.  Wlxrn  suBpendc<l  in  water  and  liciited  lo  tOO*  C, 
or  crm  to  To"  C,  it  beconwa  ch«i)|j[Ml,  and  Hiill  leut  Mduble  ihtui  tx-foro ;  it  it 
M*d  JD  tliit  tmm>  la  be  eoagnlatnl  l>y  tUe  beat,  aiid,  ha  we  «ball  mc,  nearly  nil 
|MH«Ua  bav«  the  prujierty  '>f  beiiiji  chaujii-d  iu  iiatuiv,  of  uodorsoiDg 
OMjCtiUtion  and  ao  Itpcimiiig  leM  aoluble  than  bcforn,  hy  being  cxpoaea  lo  a 
Mrtain  hi|;b  tt^>ii|H'r»tiire. 

f'itirin,  tbfii,  ia  a  protvid  dUtingublietl  from  oilier  proteidii  by  itK  cmallcr 
wlubility;  it  i*  fiirlber  dialiufcunbed  by  itc  iM>ctiliar  iilainiMitod*  stnict- 
oiv,  thv  c4bL-r  jiroleida  when  oliliiinefl  in  a  •olid  foroi  appearing  either  in 
aotorvbou*  granulr*  or,  at  miMl,  in  rUcid  masKa. 

I  If.  W«  may  now  n-lum  m  the  tmim. 

Tbia  b  perfectly  fldid,  nnd  rcmniRi  duid  until  it  deconinoeee.  It  ia  of  a 
ftint  ttmnculor,  dueto  the  pirsencoof  a  special  pigment  subatUDoe,  diflering 
frun  lh«'  red  niiilter  wbicb  Rives  red»e»  to  the  red  corpusclea. 

Tmed  by  iIh-  xanthoproteic  am]  other  lots  it  obvioUBlr  ountitinii  n  Urge 
mtantiij  of  proteid  uatler,  ami  upon  exnniiiuition  ire  flDa  llial  at  Imat  two 
iliaiioei  prulind  Mibatanoea  arc  preaeot  in  it. 

If  rry*tnb  of  magnesium  sulphate  !>«  added  tn  Aenim  and  gv^ntly  atirrt^ 
uaiil  ihny  divanlvc,  Jl  will  be  iteen  that  thi.-  »eruni  att  it  appn«cht»  uitumiion 
tritb  tbv  Mlt  lieconea  turbid  itutead  uf  renniiiiiu),'  clear,  n»d  «veiiltialiy  a 
vhtir  amor^dtiiiM  frnuiular  nr  flooculeni  pn-4-i|iiIit|i--  uiakM  Jt.i  ap|M-iiriincr. 
Thi>  pn.-c>pttatt'  tntiy  Ix-  MiKiraifxl  by  dvcautaliun  Dr  BUratiou,  waabud  witli 
iaiamtnt  MiliitiouH  nl'  mtiv'i !•''■■  ■"■i  lulpbate,  in  nhicli  it  iit  inaolubic,  until  it 
ia  frwl  fniui  idt  'ilbcr  I'lnntituciitit  of  lh«  leruiD,  and  ibufl  obtaimil  Ibirly 
INirr.  It  ia  llwn  fmjtid  ui  Iw  a  proteid  IhhIy,  dittiuguiabiil  by  ihv  liiljowiiig 
riiaractvni  iimoiig  oibi-n: 

1,  It  in  (kIii-h  I'rtM-d  fnim  iiny  iidherciit  nuigoij^luni  Milphalc)  iutnlubh)  in 
■lialill**!  waiir;  it  i*  inxiliiliU^  in  onft-niriiHnj  xilutlona  of  iwutraj  Balinc 
bodin.  Mit'h  a*  mngnniiitn  ■ulphnt'^,  Mxlium  i'hluride,Me.,bul  rMdily  aolublo 
to  dilute  ('.  y,,  1  |>er  M'Ot.i  M>lution«  of  ihc  naine  n4>uiral  Mdiuc  boiliee. 
Iliftrr  fniiD  it*  »oluli(Hi»  iu  the  latter  il  mav  l>e  prrcipit«tv<l  vitbfr  by  adding 
tnnre  aeiitral  Mline  sulwtnum  ur  by  removing  bv  dialyaia  tlM  muall  ijuantity 
„f  .,i;.,..  i^jljatBtir-e  prexent.  Who'll  i)t»laiiMd  in  a  prccipitaWd  Jorrii,  and 
*  :  in  (liidilltNl  water,  it  readily  dixwilve*  into  a  clear  solution  upon 

ibrBo.iiMtiiirasiDall  •i^tinntity  of  soiiK'iK'Ulral  saline  bixiy.  Hy  t  bene  various 
^utiond  and  jirr4.'ipiljilKi»s  it  is  not  n-aliy  ehaiigod  in  nature. 

'i.  Il  rrndily  ilim-ilves  in  very  dilute  acide  {r.i/  .'m  h^ilrwlilorie  aetd  neo 
wbefi  (liltneil  to  far  Ivm  than  I  jier  cent.),  and  il  ■«  •innliirly  Milubic  in  diluio 
aikaliQ*,  but  ill  Iwing  ibas  dissolved  it  is  irbolly  cbangv<)  iii  nature,  and  the 


46 


B  1.000. 


B<>liilii>ns  of  h  in  diltile  acitl  nnd  dilute  sHulics  eiv*  rcai-ttons  quite  dtdoi  ___ 
frDiti  i.l)u§G  •>{  tho  suliitioii  of  llie  siibetance  in  dilute  npuiral  snliue  wdiitiooi.-- 
Ity  tlic  acid  it  is  ooiivcrled  inLo  nliat  is  c&llod  (ici(/-u//i((riiin,  liy  ll>e  alkali 
iuto  alkiili-'tlbumin.  butik  of  wliicb  bodiei  ve  shall  hiive  to  Hludy  later  on. 

'i.  Wben  it  b  suspended  in  wnter  and  healed  ii  becomca  altered  in  cliar- 
acter,  mai/ulatrJ.  aud  nil  its  reuctions  are  chaujred.  It  ia  no  loDger  aolulile 
in  dilute  iiviitiid  aaliue  solutioiis,  nut  even  in  dilute  acida  and  idkulie*;  it 
haa  bceoQit;  coatittfaltd  protxid,  and  in  now  even  less  eoluble  than  fn-fii  fibrin. 
When  a  loluiiou  of  it  in  dilute  neutral  aalioc  eoluiiou  id  Nimilarly  ItcBtcd.  a 
•iinilar  cbonge  lakea  pliieo,  n  [ireeipiiale  falla  down  which  mi  cxaminiiUon 
if  fi)un<l  to  hv  cungulnlL-d  pmteiO.  Tile  iciiijionitiirc  at  which  l)ii«  changD 
tnkts  |>lac«  ia  sumewberu  nboiit  T-t~  C,  though  nhilling  itlighcl)'  acoMrding  to 
the  (]uantity  i)f  nnliiie  Kubttnncv  prment  in  Uic  Koltitinn. 

Tlicntirive  |.bn.-i.'  ruactiunii  arn  given  by  n  nuinlipruf  protctd  b<:)dies  foninn^ 
m  griiup  cullfd  alohulint,  tind  the  [lurliciiliir  gtohulii)  pra«cnt  in  blood-eenim 
is  vuUvd  jiaraijlohnliu. 

One  i>r  Ihc  pniii'id*  prenent  in  blood  m runt  in  then  pariiglnbulin,  charac- 
lerixeil  by  its  »i)liibility  in  dilute  neutral  Mlinv  x>Iution«,  ii»  in»oIubiliiy  in 
dietilird  wnter  nnd  co u <.■<.■  n I ratol  wiline  colutiouF,  its  n-iulv  Mtlubility.  and  at 
ibe  Himc  time  convcreiun  into  other  bodies,  in  dilute  acida  and  alkalictt.  and 
ID  iia  becutuing  convertml  into  coagidatcd  proteid,  and  «o  beut];  precipitated 
fVom  its  GoKitiun*  at  7<>°  C- 

The  BDifliint  of  it  present  iti  blood-serum  varies  in  ritrious  animalB,  am) 
apparently  in  the  same  animal  at  diflerent  timts.  In  1U[>  ports  by  weight  of 
serum  there  are  penerally  present  about  8  or  9  parts  of  proields  altogether, 
and  of  these  some  3  or  4,  more  or  less,  may  be  taken  as  para|;)obulin. 

§  17.  If  the  serum  from  which  the  parajilobutin  has  been  pivcipitated  t>^ 
the  addition  of  neutral  .lult,  and  removed  by  tiltrstiun,  be  subjected  to  dia- 
lysi*.  the  valt  added  may  b<!  remiivi-d,  and  a  clear,  Mmewhal  dilute*)  mtnim 
free  from  iiaraglobtiliii  may  be  obtivinetl. 

This  still  gives  abundant  pniteid  rvuicliouH,  ko  that  the  xerum  Mill  coataioa 
a  proteid.  nr  wuiie  proteidv  *lill  more  mdiiblc  than  the  globulins,  since  they 
will  remain  in  sidultou,  nnd  nrc  n-'l  pn-cipitatrd,  even  when  dialyia  is  con- 
tiinicd  until  thi-  nriim  is  pructitnlly  frx-rd  from  both  the  nuutnd  mIi  added 
to  it  lutd  the  dilTuaiblc  hiIis  previously  present  in  ibe  natural  fenini. 

When  this  scrum  is  hcnleil  to  T')"  L'.  a  precipitate  mokes  iU  appearanco; 
the  prolcids  still  present  arc  caa(;iitalcd  at  this  temperature. 

\\  c  have  some  reasons  for  thinking  that  more  thnn  one  prnteid  is  present, 
but  ihey  are  all  clowly  allied  to  each  other,  and  wc  may  for  the  prveciil 
speak  of  them  as  if  they  ueie  one,  and  call  the  proteid  loft  in  scrum,  afler 
removal  of  the  paraglobuliii.  by  the  name  of  alhunn'n,  or,  to  diatingiiish  it 
from  other  albumins  found  elsewhere,  rmnn-aibuinin.  Serum -a  I  bum  in  is 
diiJtlnguifihed  by  being  more  soluble  than  the  globulins,  since  it  is  soluble  tn 
distilled  water,  even  in  the  absence  of  all  neutral  salts.  Like  the  globulins, 
though  with  much  lets  eoue,  it  ia  converted  by  dilute  acids  and  dilute  alkalies 
iuluacid-or  into  atkati-albumin.  The  percentage  amount  of  senim-albumin 
ill  xtrum  may  be  put  donn  as  4  or  o,  more  or  less,  but  it  varien  and  some- 
limcd  io  l<Mi  abundant  ihaiipaiaglobulin.  luBomeanimala  (suak<»)it  is  said 
to  dirapjit-iir  during  Marvation. 

TIh'  more  imp'irinnt  chiiraclcnt  of  the  throe  pmteids  wbioh  we  have  jiial 
ttitdicd  may  l>c  atati^d  a^  lolluu'ii: 

BoIiiMb  til  <li>tlllf4  wklor  bdiI  In  mIidc  t-iluli<inf  of  nil  ^IreuElli*      -    nenin-aUiimi* 
InKiliiMr  in  ilidiUt^t  walxr,  nodll/  riliiUto  inililiil*  (alin^  KtlnUcin*, 

Intvtiitl*  lu  omcaiiiraidl  •iillno  mliiUoDa  paragbtMim. 

tnioliiMa  ID  illitlllnl  wjilcr.  Ii-ir^llr  iviuMa  at  sll  id  ililiiU  aUfno 
KiluUon*.  an4  vvr;  tliUatuIuUsIn  nraiv  (OdivntraiMl  mIIuohiIu' 
tko* .iftria. 


I 

I 

I 

I 

t 

1 
I 

I 


rnS   L-LOTTtA'O   OP   BLOOU. 


47 


I 


Bndiln  (inniglobiilln  slid  ecru lu-al bum iit,  wruin  couiniiM  ii'verjr  luge 
n ■!■!>■  f  nf  subMuDCM,  f^enernlly  iii  mduII  <iiiiiut!(r,  wliicli.  miico  tki^  )iiit« 
to  b*  ntnMlt«)  hy  b|«cibI  n>vth(><ls  arc  i-ailetl  txtracliK":  of  lli«#c  tti'mc  U« 
Mtr<i1t*onu>,  anioe  noD-aiirogeooti*.  .Serum  vi>ntaiii>  boridca  i»)|Mttaiit  iiior- 
(snir  HtitK*  mlwtaDcn:  but  lo  th<9«  ire  duitl  n-lunt. 

t  IS.  With  the  knuwlttl^L' wbifh  we  liavegaiwil  ofllH-  iiroirtdn  ofcIiKltiJ 
bloi^  wr  mav  e*)  t>a<.'k  to  Uw  'iix-MlioH :  Clotting  Wing  (liii*  In  (he  ai>iirnr< 
aiK«  in  bliMxl  |iln--iiiii  «t'  a  proteiil  MibslADCC,  liliriii,  vthU-li  iitvvuiii^Iv  din  not 
tairt  in  it  aa  w-h.  w  hm  an-  iliv  miisM  whldi  Inl  f >  l)iv  ni>|>Mirniirc  of  Hbrin  t 

W«  Irani  MiniHtiiiif;  bv  ndidying  llii>  iui«t  ini|iiirrniil  irxUToal  ciiviim- 
Maneat  which  aircci  ibi.-  rapidity  niili  which  Uw  blutxl  ul'  lli«  sain«  indirtiluat 
dstt  mhto  thcd.    Thm!  arc  m  Ibllowa: 

A  uiDpt>ntmvnr'10°  C  xhidi  b  aboul  or  fllgbtly  «bo\-f>  tho  tempemlure 
of  lb*  Uoorf  »f  KHrni-bliMdcd  anrnwl^.  la  |>i.Tlin[«  the  moM  favorable  lo  clot- 
tiag.  A  Airllwr  n*t>  of  a  few  dterMs  i*  ii^i|<arcntl}r  alio  bcii«6cial,  or  at 
toM  sol  Injiirimii ;  btlt  upon  a  eliirriirthcr  tw  lh«  rHc«t  chancn,  and  when 
bleed  ii  npidly  heated  to  M^  C  do  cluUing  nl  all  mav  Ukc  gtlBce.  At  this 
iMBpoMurt  evrtain  pmMidsof  tbv  IiIwhI  an  oungufntcd  and  prMJpiiaied 
h^on  elcUioc  i-aii  laao  iJacr-,  and  With  this  cbaage  tbc  power  of  the  blo«xl 
to  clot  is  whMly  hwt.  ir,  hoWL'Tcr,  the  hcaliDg  be  not  very  rapid,  tho  blood 
naijr  clot  bcforv  this  changD  hns  time  to  cone  on.  When  ihe  (emperatore 
ioalcad  uf  being  miM^I  is  lowered  below  i.0'  C  tliir  cloltinj'  l)e<x>Ttiee  d«layeil 
aail  pmlongeil ;  and  at  the  lenipenilure  of  0°  or  1"  C.  the  Mood  will  r«maiji 
flaid,  and  yvt  capable  of  clollin^^  whi^o  willidrawn  from  llic  adverec  drcuin- 
■cuwca,  for  •  rtrt  lonf*.  it  niit;ht  alaraat  be  aaid,  for  an  indefinite  lime. 

A  (cnall  quantity  of  hhMid  ihcd  into  a  small  vewel  clote  sooner  than  a  large 

■  onsMity  •htil  into  a  larger  <>»e ;  and  in  general  the  greater  tbc  amount  of 
Ml  ail  n  furrncc  with  which  the  blood  conxw  in  I'vniait  tlw  more  rapid  ihc 
dnUtBg.  y>'htu  vhrd  blood  i*  Mlrrcd  or  "u'hip[N.-d"  the  fibrin  niakca  its 
■ppMrance  mh-imt  than  when  the  blood  n  Icll  l»  clot  in  tbo  ordinary  way ; 
■t>  that  hi-iT,  tiKi,  ihtt  acccK'niling  iiitluvncv  of  contact  with  furei^  bodiea 
Bakes  ilwlf  ft'lt.  Similarly,  niuvi-nu-iit  of  fhcil  blo<Ml  hnaloDii  clodmg,  ritice 
il  iscrraHK  the  amount  of  contact  with  foreign  bodioL     So  aleo  iho  addition 

■  wf  MoagT  (ilatinuni  «r  of  powdered  charcoal,  or  of  other  inert  powderv,  to 
lardilf  riulline  liloml,  will  by  inflncnoe  of  ftiirfaco.  basleu  dotting.  Con> 
vmtfV,  bloiwl  brought  iut'>  d^nlad  with  pure  oil  docs  not  clot  to  rapidly  ns 


la  coiiiact  Mill)  gliiw  or  metal;  n»d  blood  will  continue  to  tluw  for  a 
_  time  without  clotting  throiigb  n  lube  »ineared  innide  with  oil  than 
ihlOTgb  a  tube  not  to  nmenrcd.  The  inlliienoc  of  the  oil  in  Buch  cnaee  is  a 
|itiy«irml  not  a  chemical  one ;  any  pure  neutral  inert  oil  will  do.  Ae  far  as 
wa  ktiuw  thp(«  inlluencea  afleet  "oly  the  rapidity  uith  which  the  clutling 
take*  place— that  if,  the  rapidity  with  which  the  fibrin  niakee  its  appear- 
ancv,  iMit  the  amount  of  clot,  not  tlie  (junnlily  nf  fibrin  formed,  though 
when  clotting  it  very  much  retarded  by  cold  changes  may  ensue  whereby 
tbe  aoMNint  of  dotting  which  eventually  takes  phicc  is  indirectly  aflected. 

Iftn  etpoaure  l<>  air  eserls  apparently  little  influence  on  Ihe  process  of 
deuisf.  Blood  mllecled  direct  from  n  hloudveairl  over  mercury  so  as 
wboUy  to  exclude  the  air,  clots,  in  a  general  way,  as  rewlily  a«  blood  freely 
fX|NMd  to  thv  air.  It  b  only  when  blood  ii>  much  laden  with  carbonic  acio. 
lb*  prewDce  of  which  it  antagonistic  to  clotting,  that  excluHon  of  air,  by 
UlMlefio|t  the  escape  of  ll»e  exetw  of  carbonic  ncid,  delays  clotting. 

TImm  ncta  icaui  us  that  6brin  ihiee  not,  an  was  once  thixight,  make  its 
■PpMrinn»  In  alitd  bloixl  because  ihe  blood  when  shed  oeosea  tu  share  i»  the 
iiimiineHl  of  tbc  circulation,  or  because  the  bl(K>l  is  cooled  on  leaving  the 
warn  bodr.or  because  the  blood  is  then  nioro  freely  cs]Msrd  to  the  air;  they 


Li 


48 


BLOOD. 


further  ftigEHl  |fa«  view  tliiil  ihv  Hbrinbtlie  result  of  some  cbemical  _ 

the  cxHiviMvioa  ioto  libriii  of  mimL'thiiitc  tvliiob  U  not  tibriii,  the  cbuige  like 
Otli«r  clicmica]  cbangei  Iwiiig  nicwt  uclivt;  at  iiii  ofilimum  tempenitlire,  and 
like  fo  ninnv  otber  chcfnicnl  clinii^ro,  Iwing  nsHniinl  by  ihi'  iiiHu€Deea  cocflrtcd 
by  the  [imwiiM  of  iiwrt  bwiiw. 

And  nc  have  direct  I'xpcrinivntul  evidence  thnl  pliutitm  does  contain  aa 
SQle4.-eddiit  nt'  tibrin  whidi,  by  rlit'niicnl  change,  it  convvrlMl  itito  fibriu.       fl 

§  19.  If  bloud  bo  rvcoivcd  ditvL't  rrom  ibe  blood vrsM-ls  into  oue-ttiird  il^ 
bulk  of  a  aaturaced  soltilion  of  toniv  tit'iiCrnl  iHilt  Fiich  m  iiiae>"'iuni  :iu]|>bnti.>. 
and  the  two  gently  but  thoniiighly  niised.  clotting,  <ii|iuriiUlv  iil  u  mixk-r- 
iiU^ly  low  tcni]>er«tiire,  will  be  deferred  for  ii  very  long  limo.    tf  tbs  tnixtuxd 
lie  nllowed  to  stand,  the  corpuHi-lea  will  bink,  iind  ii  uoWlov  nlanni  will  1^1 
obtained  siinitar  t«the  {ilaaina  ^tiined  froni  horse':'  blood  by  mid,  cxcvpl  thnt 
it  contains  an  excess  of  ibc  neutral  salt.     The  presence  of  thv  neutral  «alt 
luu  actod  in  the  same  direction  as  cold  ;  it  bus  prevented  the  occurrence  of 
clotting.    It  liaa  noidestroyed  the  fibrin:  for  if  some  of  the  plasmu  Iw  diluted 
with  from  liv«  to  ten  timea  its  bulk  of  water,  it  will  clot  speedily  in  quite  a 
normal  fashiou.  with  the  production  of  ijuite  oonua)  librin.  h 

Tlic  separation  n(  the  fluiJ  pluma  from  the  corpuicle*  and  from  other  bodE^I 
heavier  lann  th<>  pluimn  U  much  fiurilitiilpd  by  thr  u»c  of  the  cpnlrifagnl  machine. 
Thia  cuiisintfl  nLionUnlly  afu  lirelcm  wheel  with  suvernl  ipvkes.  placed  in  a  hori- 
ziiQlal  podUou  and  tiiude  to  rdvulvewltli  great  velocity  ilWx*  reToIuttons  per 
minute  for  iottaDca)  around  it«  axis.  Tubc«  of  metal  or  very  Strang  gloM  arc 
Hut|>eiided  at  the  ends  of  tlie  >|iokni  by  carefully  at^ustod  joint*.  Aji  the  wheel 
roinies  with  increaung  relciiiity,  eoi-li  tube  gradually  Maumoi  a  horitoolal  poal- 
licm.  bothim  outward,  without  iipilllng  any  of  Its  conienla.  Ai  the  rairfd  TOtatioD 
cofitiuuH  the  corpiixulcti  and  heavier  particles  are  driven  to  the  bo4tofnof  th« 
lube,  and  il  n  very  rapid  movooiont  be  continued  for  a  long  time  will  form  a  com- 
pact cuke  nl  the  bottom  of  tlic  tube.  When  the  rointion  in  stopped  the  lub«a 
gradually  return  li>  llieir  upright  poaltioo  njrnin  wilhnut  anything  beins  npilt. 


an^ 


the  cl«ar  pluania  in  cocb  tube  can  then  be  decanted  oil'. 

If  some  of  the  colorleaa  tranaparcni  ptasmn,  obtained  either  by  ibe  action 
of  noulrul  sall«  from  any  blood,  or  by  llie  help  of  cold  flrooi  horee'e  blood,  he 
treattnl  niib  some  solid  ntiiirul  sail,  siicb  an  Imodium  chloride,  to  saturation,  a 
white  ilaky,  soruewhai  eiiL'ky  pii?cipiiate  will  make  itn  ap|>earaiice:.  If  thia 
precipitate  be  removed,  the  fluid  no  longer  pcaaewct  the  p(iwi:!r  of  clotting 
(or  very  oliKbtly  so),  even  tbougb  the  neutral  salt  pr«wciit  bi^  removed  b^ 
ilinlyaU,  nr  iu  influence  leeaeueil  by  dilution.  Wilh  the  removal  of  tlte  suH| 
niaiice  prcnpiialed,  the  plaima  ban  lo!<t  itsi  power  nf  clotting.  ^^ 

If  the  ]rreci])itate  itwif,  afl<T  beiiij;  washed  with  a  mturati'd  Molution  of 
the  neutnd  salt  i,in  whlc-li  it  i.i  insoluble)  to  a*  tn  get  rid  of  at!  wrum  and 
other  eonslituenld  of  the  pbiyma.  be  Ireut^tl  with  n  smnll  ijuiintity  of  waMr, 
it  readily  dtMolvea,'  and  thi;  foliitinn  riipidly  filtered  givc«  a  cicnr,  colorleas 
liltraiv,  whidi  i«  at  ftr*t  jM-rfrclly  tinid.  i^on,  however,  the  flinditv  givea 
way  to  vi«'idily,  and  lhi»  in  turn  In  n  jelly  condition,  and  linally  thcjclly 
Ghriukv  into  u  dot  fltMttn^  in  ii  dcnr  Huid  ;  in  other  wonls,  the  filtrate  clot* 
like  plasma.  ThiiN  tbon-  is  iirtvcnl  in  cooled  plasma,  and  in  pliismn  kept 
JVoia  clotting  by  the  pn^-noe  of  neutral  salu.  it  somethiiiif  pn^ci  pi  table  by 
mtnntion  with  uculnd  ^nlUi — a  Foni<'ihing  which,  aiuee  il  is  soluble  in  very 
dilute  Mlini^soliuinns.  cannot  he  tibrin  itself,  but  which  in  solution  speediljr 

K'ves  Hm  to  thti  appearance  of  tibrin.     To  this  subnauc«  iia  discovered 
enb,  gave  the  name  of  plaimiue.  ^ 

>  Tbt  iiibManM  luctr  ti  Dot  tolnUe  in  eliUIked  wtivi,  i>ut  ■  umiitliy  ol  thv  nnilml  mII*  alinui 
(Man  to  tbv  ivMirliaw,  •ii'l  <Hi»  Ilia  a-bllUon  ot  w>M  rlnuatfy  gtm  rtt  lo  dilute  lalltM  aduilLin, 
fa  oalcli  Uw  •utaiauw  ■•  rniOll]'  wlubli:. 


THK   CLOTTISO   OF  Dl.OOt). 


-49 


I 


TIm  MihaUincc  Ihii*  nrvciptlmlcil  U  not  how«rer  n  Kn^h;  )>lh1v.  bul  n  mix- 
tan  of  M  \auA  tito  botliea.  Ifsudium  clilondo  b«  i-xn'tulU-  luliW  lu  pljuma 
h>  mtt  •XMOl  of  kImuI  n  |i«r  cvni.  n  wliiie  fliiky  vi*ci<l  pmciplntv  ix  ilirunra 
Aoma  Xfrx  much  like  iiliuniini:.  If  alU-r  ihc  rcmo\-»I  ol'thv  Rm  |(r«(-i(iiutl« 
•tijiuai  chloridr,  Miil  <'«(ir>:inlly  if  iiiAgtmium  sulphsto  bo  mlilrt).  a 
'  precipitate  u  tlirowii  duwii.  Iu<«  viitckl  nnd  inure  ffruiiil&r  tliAii  the 
int. 

Tha  aMond  pnvipiUiii;  whcii  <'xam!n<?l  i«  found  ut  bd  identical  vilh  Uto 
fmrmgiahmiut.  cMigiilnliiig  at  7'}^  C.  which  we  have  nircadj  aeen  to  Im  » 

«fMMUl4Mllt  uf  WrilRI. 

Tba  Ani  pret-i|>iuil«  ia  also  a  proteid  balongioi;  to  lli?  (clobullQ  ([roup,  but 

ftn  lV<>iii  |>;vrit;;lubuliR,  not  otilr  in  beinj:  rnure  r«n'lil>'  prccipttutud  by 
waUrn  chloride,  and  in  b<-in^  wh«n  procipilaied  inure  vineid,  but  ubto  in 
(4iMr  rspww.  and  eepeoiallr  in  being  coagulated  at  a  far  lowor  tvinpornturv 
tkao  |MtnicI»bia,  vix.,  at  S(i°  C,  Now,  nhile  i^ulatvd  pamglubia  canuol  by 
may  maaM  known  to  ua  be  converted  into  6brin.  and  aa  ti«  procnoc  in  the 
MMxUted  plawnine  doea  not  aeem  to  be  OMeaiiu)  to  the  formation  of  6brio 
oat  of  itlaamiDe,  tbe  preaenoe  iu  plaamine  of  ih«  IhhI y  oiiapiUting  at  56'  C, 
4o«  aaaoi  oiMutial  to  the  otKireraiMi  of  pla^tmine  into  fibrin,  and  we  have 
fMin  S>r  thinkinir  that  it  'n  tUeU  ctjnverlc<),  in  pitrt  nt  least,  into  fibrin. 
Hmc*  it  ha*  rvceiveil  the  name  of  filiriHw/en. 

d  so.  The  n-atritLH  for  thU  v'mv!  nri;  an  folloWM: 

Bfaidai  blood  wbioh  clot*  naturalljr  when  ahad.  thert-  are  Mrtnin  fluids  in 
iba  bsdjr  which  do  not  elot  nniunilly,  citber  io  the  b.idr  or  whuti  abed,  but 
which  t>r  cvriiiin  artifir'iitl  mean*  may  b«  mado  to  clot,  and  in  cloltinj^  tu 
jriaJd  ^nttr  normal  fibrin. 

Thoe  tb«  »0'i-all(Nl  ecroin  fluid  lakrii  Mroc  hours  after  death' f^om  the 
perifanlial,  pleural,  or  peritoneal  t-avities.  the  ituid  found  in  the  volarved 
tareaaakc  uf  the  leatis,  known  ad  bylro^-ele  lluid.  and  iitb<-r  »imiliir  fluids, 
«91  is  the  majority  of  oues,  wlteii  ubiaineil  free  I'roui  blood  or  othi-r  admix- 
lana,  rwmain  fluiil  almost  iudeRoitoly,  shuwinjf  no  diipiwiiiuu  whnlerer  to 
doc'     Yet,  in  muK  t-adce  at  uU  events.  tli«M:  Ituidd,  when  a  little  blood,  or  a 

St  of  blood  olot,  or  a  little  terura  h  addul  lo  iliem.  will  clot  rapidly  and 
Ir.'  g:ivin);  riae  to  nu  uoroiMakable  clul  of  nomal  fibrin.  ditTiiring  only 
fritn  tk<>  clot  of  blowl  in  that,  wlieu  ■crum  ia  usad,  it  i«  colorless,  being  fnt 
from  rtti  corriuidot. 

Nnw  blood  (or  blood  clot,  or  iwrum>  contains  manv  thinga,  to  any  one  of 
vUch  the  clouiog  power  ihuvuvcn  mixhl  beatlribiiUM).  But  it  h  fuiind  that 
ia  BMuy  ouea  dotting  may  Ix.-  induced  in  the  Buidt  of  which  we  are  speak- 
iac  hj  the  mttf  addition,  and  llial  i-ven  in  <:xciixlingly  small  iguantity,  of  a 
PiMlUK!*  which  (»n  bo  cxlracl^-d  from  l>I'x>d,  or  from  serum,  or  from  blu:)d 
doCurerMi  fnim  waithed  librin,  or  iitiL-cl  fryjm  olhor  aourcea,  a  subataooe 
whoM  rxMct  nalurr  i;  unn-rlniii,  it  Ik-Ir);  doubtful  whecber  It  is  a  protaid  at 
alt.  aoil  whoM'  acii«ii  i*  jMrouliar. 

If  eenim,  or  wh!pj>nl  blood  or  a  brokcn'Up  olot  be  mixed  with  a  large 

riBlity  of  alcohol  and  altowHt  to  ataad  some  days,  the  prvileids  preseai  are 
tine  M  changed  by  the  alct^Mt)  as  to  become  insoluble  in  water.  Hence 
if  tbe  orpiooa  precijpitote  caused  by  the  nlrobol,  after  long  aiandinjc.  be  sepa* 
rated  hr  filtraiion  from  tbe  alonbol,  dried  at  a  low  temperature,  ugt  excead* 
la(  40  C,  and  exlmcte<l  with  dutilled  water,  the  aiiueous  extras  contAiitt 
tittle  protetd  matter,  indeed  very  little  organic  matter  at  all.     NeTSi^* 


1  ir  H  b«  tnoavwl  InawluMi  tlUi  iIhiIi  u  gaiisrally  cM>  rMdltr  aad  dralv.  ftilai  ■  oolarlcM 
CM  OMiMtBe  of  sum  •iM  >(dta  owiouIm. 

•  la  BM*  (faiDiHai.  iM«*<t>.  •  ■■•MUaaint  oMfoWiiB,  sft.'»llr  iltsiii,  tat  iii  «xotf€iaiwl 
•■■•  maMf*.  mtj  Im  ulaanwL 

•  tM«S»w*aaM^eMsid*»aaaruiib«tbrtiid*<v4. 

« 


50 


The 


tbelcae,  eveii  8  aninl!  tuinntity  of  lliis  afjiiPfnis  extract  milled  aliDe  to  oertitto 
sneciiQctiBiirby<)r>H-elc  tluiJ  or  other  of  ihe  HnkU  H[>i>ke(i  of  above,  will  brio;; 
Kuotit  a  Hi^edy  dottiug.  The  eaiiie  a>iueoi»  extract  has  alau  a  remark  a  b£ 
l^l^l;cl  in  biuteDiun;  the  dolung  at'  Hiiids  which.  I.hougb  they  nill  eveotually 
cloL,  do  so  ver^  slowly.  ThiM  ptaNiiia  may,  l>y  the  careful  addiiJoD  »f  n  cer- 
tain quBiittty  uf  neutral  «alt  hdiI  water,  be  reduce*)  ti>  mich  a  condition  tliat 
it  i:l»i*  Terv'iilowly  indeeil,  taking  perhapM  day*  in  cDnipleli;  the  proccM.  Tlte 
addition  111  a  Anall  ijuaiitity  of  thi:  »i|iie<iiiK  estrart  wc  are  iJeacribing 
huwi.-vi-r.  bring  abiiut  a  i-Inlliii);  which  w  at  i>nc«  lapiil  and  complete 

The  active  rubotancc,  uhaltrvrr  it  he,  in  thii<  a<)ucons  «xlmct  exists 
rmatl  quantity  only,  anci  iiR  cintiing  virtues  are  at  odcc  and  forever 
when  the  wintion  i«  boiled.  Further,  there  is  no  reason  to  think  thai 
active  8ul)s(iince  actually  enters  into  the  formation  of  the  tibrin  to  whieh  it 
glTM  rise.  It  appears  to  belong  to  a  clasi  of  bodies  playing  ad  imiw.rlnnt 
pitrt  in  pb^'siologicn I  proc^iMS,  and  called  fermenU.ot  which  wo  shall  have 
more  to  say  hcrcaficr.  We  may,  therefore,  ^peak  of  it  as  xhv ^rin  ferment, 
tbe  DBiue  ^iven  l»  it  by  its  discoverer,  Alexander  Schmidt. 

This  Kbriii  fcniit-nt  is  prec«Dt  id  and  tuny  beeilraclcd  from  dolled  or 
whipped  blood,  itnd  from  both  tbe  dot'  and  the  serum  of  dolled  blood  ;  and 
bince  in  moel,  if  not  all.  cases  where  blond  or  blood  clot  or  serum  produces 
clottiuK  in  hydrocele  or  peiicardial  Huid,  an  exactly  similar  dolhinv  may  be 
induced  by  the  mere  additiou  of  fibrin  ferment,  we  seem  justifieu  in  eon- 
duding  that  the  doitiiiK  virtues  uf  the  former  are  due  to  tbe  ferment  whic 
ibey  contain. 

>i«w,  when  fibrinogen  b  precipitated  from  planma,  as  above  devcribttl,  L  ^ 
sodium  chloride,  redissolvetl,  aud  renrrcipitated,  more  than  onoc,  it  may  be 
obtained  in  wlution,  by  h«lp  uf  a  iJilute  neulnil  mlinv  solulion,  in  an  *E^ 
proximnielv  ptirv  condition,  nt  all  evciiM  free  from  oilier  protCKU.    Such  d 
solution  will  not  dot  ■poiilHiieoiisly;  it  may  remain  fluid  indclinitely ;  an^^ 
yet  on  the  addition  of  a  little  Hbrin  fcnueni  it  wilt  clot  readily  and  firmly, 
yiddinc  quite  normal  fibrin. 

This  body  libriiiogcn  is  also  present  and  maybe  separated  out  ftom  ti 
spccimcDB  of  hydrocele,  pcrieaniinl,  and  otlier  fluids  which  clot  on  tli 
addition  of  fibrin  ferment,  and  when  the  fibrinogen  has  been  wholly  retuovi 
from  these  fluids  they  lefuse  to  clot  on  ibe  addition  of  Abrin  fttmeut. 

raist;h'bulin,on  ibe  other  hand,  whether  pieparcd  from  ploamine  by  scpa- 
ration  of  ibe  fibrinogen,  or  from  aeruni.  or  from  other  fluids  in  whidi  it  ij 
found,  cannot  be  converted  by  flbrio  ferment,  or  indeed  by  any  other  mrat^l 
into  tibiin.     .\nd  fibrinogen   i.wlaled.  as  dMcrihed  above,  or  serous  tlutda 
which  I'oiitaiu  fibrinogen,  nin  he  made,  by  mcanc  uf  fibrin  ferment,  to  yi«l<l 
quite  uiirnml  ^hrin  in  ihe  <um|i1eie  abwnce  of  paraglobulin.     A  solution  of 
paraglobulin  obtained  from  »erum  or  blood  dot  will,  it  in  Inie,  clot  pcricar- 
car<luU  or  hydnicdc  tltildii  containing  fibrinogen,  or  indeed  a  KiluliDa  of 
fibrinogen,  but  thi«  U  apiiarenlly  due  to  tbe  fact  ihal  the  imirnglobiilin  ban 
in  ihm  cucn  fonie  fibrin   fcrmrnt  mixed  with  it ;  it   is  aUo  puiixible  tbut, 
under  rcrlain  C4>ndiiioiis,  the  pr«»enc«  of  paniglobulin  mny  he  tiivorable  I^h 
the  action  of  the  lermenU  H 

When  the  so  caDtd  pln^mine  is  preelpilatcd.  a»  directed  in  S  19,  fibrin  fer- 
ment is  carried  down  wiib  ihe  fibrinogen  and  paraglobulin,  and  when  tbe 
pliismine  is  iC'diHolvcd  ihe   ficiment  i»  prrsent  in  the  solniinn  and  ready 
act  on  the  fibrinogen.     Hence  ihe  redissolvcd  plasmine  dole  spoDtaneou»lj 
When  flbriuogen  ts  isolated  from  plasma  by  repealed  precipitation  and  aolu 


Kin- 
»Iv. 

i 


the 

i 


■  A  wtKrlUI  wlaUon  «f  nbtln  fcRirtiil  mty  l*  rMdllr  |>ni*n<l  !■)'  tUa\it 
bliH'd  I'lol  vtll  ■  lU(*ruDI.  »tiiil<in  or  •■xlluni  chloriilc. 


xmrUna  •  wulicd 


TUK   CLOTTING    OF    DLOOU. 


51 


P 


tfaa,  ibfl  CtmuMl  H  WMhed  nway  from  it,  vnil  [he  nura  fcnnvnC-rrvi'  (ibriii- 
mtm,  ultinuiti'lr  obtaiiHy),  i\i>ts»  not  dot  «ponlaD<i»ii«ly. 

iki  fmr  it  mvhio  cl«iir  thai  thciv  doos  oxMt  ■  proteld  hndy,  Rhnnoga},  which 
mmj  by  the  m-tJon  of  fibrin  ferment  hv  <)!rrclly,  u-ithuiit  tht  intcrvi-iition  i>f 
NtMT  proleidA.  <:i>avi.'ttr(l  iolo  ibc  ]*>«  m>lubic  fibrio.  Our  kiiowlnlge  <>j'  lliv 
nnnHllilifin  of  proteid  Ixxlics  is  too  iin|>crfoct  to  eiiablo  us  lu  iiiako  unv  v«ry 
ddbilta  M*leiu«nt  ■»  to  the  cxiict  nnUira  of  Iho  chnn^  thus  dTcctcd  ;  but  we 
mj  MT  ibie  mucli.  Kibrinof;cn  anil  fibrin  hnve  iibinit  iho  trntav  (.'li'iucntary 
■OBpcaitloD,  fibriu  ouuUiniiiK  fl  triHe  inoro  nilro);eii.  When  fibrinogen  ib 
eMmrtrd  into  6brin  by  nwans  of  Kbrin  fermcDl,  the  weight  of  the  Hhrin 
ptvdocBd  k  aJwayn  l«i>s>  than  that  of  ibe  Rbrinogen  which  ia  consumixl.  and 
tbvre  y  bIwos  jiroductii  at  the  aanie  time  n  t'ertaiu  quHutitr  of  nnothrr  pro- 
Uid.  iMloogiug  tu  the  );lubu1iu  family.  There  are  reaauna,  liuwever,  why  we 
OkOM*  ipaak  of  the  furmcul.  un  tjttitliH^  up  6brinu^D  into  librin  and  a  glo- 
bolin :  it  avcmi  moro  fmihHbl«  that  tike  ferment  cmverU  the  librinogen  lirst 
into  m  liodv  whi<^ti  «i-  luivht  call  toluhU ^rin,  aiul  then  turua  this  body  iutn 
rentable  lihriii ;  l>iit  furihvr  iH(|uine«  un  lite  subject  are  needed. 

It  nay  b«  uihU-fl  ihiil  among  thi;  cnnditiom  ncM«iary  fur  the  due  action 
of  Sbrin  rr-rawDt  on  fibrimigCD,  the  pruwooe  of  a  certain  quantity  uf  sonn 
Hairal  talt  Kvns  to  b«  one.  In  the  total  abaence  of  all  neutral  aalin  the 
ftmmX  oinnot  convert  th«  fibriDogvn  into  fibrin.  There  arc  itume  reuaouB 
ako  Jbr  thinking  that  the  pn-aciice  of  a  lime  .talt,  «uch  a«  calcium  aulphale, 
tlMOgli  it  nay  be  in  minijie  i^uMntity  oidr,  U  <-]wiiiiitl. 

ffi.  We  may  convlude.  Ihcu,  that  the  plnHnin  uf  hhxMl  when  Hhed,  or,  at 
•U  «f«Bla,a(KiD  after  it  h»»  l>e<.-»  *liL'd,  contnin*  librini<)|:en ;  and  it  al«o  Mcenia 
pn>lwbl«  that  the  clotting  cmiiiii  about  Ifcauio  ihf  Hlirinoj^  is  mnvurietl 
Btio  tMa  by  the  action  r<f  librin  fvrniritt. ;  but  wo  nrcilill  far  fmni  a  <Ivfiuit<> 
aanrar  to  the  (pMsliMi,  why  blood  remains  fluid  in  ibe  body  and  yet  clut« 
wbra  »hod7 

We  have  already  uid  that  blood,  or  blood  ploama,  brought  up  to  a  tem- 
pefBlttK of  56'^  C  »  «oon  as  |H«iiibIe  sAer  tla  removal  from  the  liviDB  blood- 
•MMk,  givM  a  proicid  pr«;ipiiate  and  1u«m»  it«  imwer  i>f  clotttnu.  This  may 
W  taken  to  *how  that  blood,  m  it  circnlaifo  in  the  Uvinfi  bloudvewela,  con- 
talaa  flbriaoiNn  a»  nich,  ami  that  nhm  the  hlui»l  ■•  heated  tu  56°  C.  which 
ia  tbe  cimguTating  point  of  libriHcrgcu,  the  fibrinogen  proteul  ia  cuaKulateil 
aul  preripitnltil,  and  conwK|ueully  no  librin  can  lie  formed. 

FurtlMT,  kIiiIi-  riotlod  blood  uiuluul.U-dly  i.i>niBini>  un  abundance  of  fibrin 
fcnerot,  ii»  fi*rn>ciil.  or  a  minimal  c|ii]tniiLy  only,  i»  preeent  in  blood  lu  jl 
Iravr*  llu>  blood v(tPi*l>.  If  ih*-  blond  be  rcceivt'd  directly  from  the  blood- 
weak  iutii  eloihol.  tlir  niiuentin  extract  pr\-|<an-d,  ai>  directed  above,  cou- 
taioe  Bii  frriiicnt,  or  mrr\'ty  a  truce.  Apparently  ihv  ferment  maktv  itM 
appearani-r  io  the  blood  ae  llie  result  of  eliangm  taking  place  in  the  blood 
aflcT  it  hat  licen  ahed, 

We  iiii):hL  from  ihia  1>e  inclini-d  to  (-oneUide  that  blood  cloU  wlM-n  lilied. 
bat  iMit  betori!,  heeaoHe,  fibrinogen  being  nlwaya  prreeut,  the  chethlinii  bringn 
abuut  ctumgea  ithieh  prMluce  fibrin  fernieiit,  not  previonely  csi«ling,  and 
thii  acting  on  the  (ibriiKigen  gives  riae  to  librin.  Itut  we  meet  with  lliv  fol 
kiwinf  difBirulty  :  A  very  couHidt-rablo  i)uaniily  of  very  active  ferment  may 
be  injected  into  the  b I oiid- current  of  a  living  animal  without  necrvvarily  pro- 
Jad^  any  cl'>tiing  at  all.  Obvi<Hifrly  either  hlood  within  the  blixidvemcls 
da«  twM  contain  liljrinot;en  ati  such,  and  the  librioogeo  detected  by  healing 
tko  bloud  tu  >'><{'  ('.  i*  the  ivsult  of  change*  which  have  already  eonted  Iwfore 
thai  lerap^mtun-  i«  nacheil :  or  in  the  living  i-irnilaiiou  there  are  agcocica 
■Cwwk  «hioh  provrni  any  ferment  which  m.iy  Im  tuLroduccil  into  the  cireu- 
Inlioa  from  pruduciog  iu  usual  efl^la  mi  tibrmo^n  ;  or  there  are  agvnctva 


62 


BIiOOD. 


at  work  which  dntro^,  or  do  away  willi  the  fibrin,  little  hy  little,  aa  Jt  b 
formed. 

$SS.  Antl  inilecti  when  wo  rvfl«ct  bnw  citi)])I«x  btoixl  ■»,  and  th«  toauj 
and  great  chniigra  U  is  simocptiblc.  wr  shnll  not  wonder  tlutl  ihe  quettion 
nre  mittiiiK  cnnnot  be  answorcd  off  hand. 


I 


The  coriiusclftt  with  which  liWd  ic  crowded  uro  living  stnieturei^ 
coniMKiiictitly  nro  continually  ticttng  upon  nnd  being  aeUd  upon  by  the 
pliuiDB,  The  rod  corpuscles  il  is  tniB  are,  m  n-e  AmU  h«.  pcctilinr  bodici, 
with  «  rc«tnct«d  life  and  a  very  speeialized  work,  and  pomblv  their  influ- 
cuc«  on  the  plasma  ii>  not  very  gn>at ;  but  we  have  reason  to  think  thai  ibe 
relations  boLwcen  ihe  while  corpuscles  and  the  plasma  are  close  and  im- 
portant. 

Then  af>ain  the  blood  is  not  only  acting  upon  and  being  acted  upon  by 
iho  several  ttsFues  oa  it  flows  tbrotigh  tlie  various  oamllaries,  but  along  tba 
whole  of  its  course,  tbruugli  the  heart.  ar(«riefl,  cnirillaries,  and  reins,  is  acl- 
io^;  upon  and  beiog  acted  upou  by  the  vascular  walls,  which  like  the  rest  of 
(he  body  are  alJve,  and  being  nlive  are  continually  undfirguin;i:  ami  promot- 
ing change. 

That  relution«  of  Aorae  kind,  haviug  a  direct  iufluonoeon  ihecloUingof 
blood,  do  exi»t  between  the  bl»od  and  ilin  vaMCiilur  walla  is  rthown  by  the 
following  facts: 

AiitT  d«aih,  when  all  motion  of  the  bloot)  haji  ocaM*!,  tlie  blood  r«(uaiat 
for  a  long  time  fluid.  Il  is  not  until  some  time  nfUrwnrd,  at  an  epoch 
when  post-Diortom  ehmigej*  in  tbc  IjIoikI  aiiil  in  the  bloodveMvl*  bas-e  hod 
time  to  develop  thcniscrvi's,  ihat  clotting  Iwgins.  Thus  Rome  houiv  after 
death  tbe  blood  i»  the  great  veins  may  he  found  i>lill  pcrfecllv  fluid.  Y(t 
such  bloorl  has  not  lost  its  power  of  dotting;  it  slill  cIoU  wlirn  removed 
from  the  body,  and  clots  too  when  received  over  niereiiry  without  exposure 
to  air.  showiug  that,  though  the  blood,  being  highly  venous,  b  rich  in  car- 
bonic acid  and  contains  little  ur  uo  oxygen,  iio  fluidity  is  not  due  bo  any 
execm  of  carbnuic  acid  or  abni^nee  of  oxygen,  Kventuatly  ii  does  dot  even 
within  tbe  ve-tii^lH.  but  |ierha|<!i  never  so  firmly  and  completely  at  wl»eu 
ahed.  Il  clots  tSriil  in  Uie  larger  ve>Mel-t,  but  reraainsflui<l  in  the  amaller  ves- 
sels for  o  very  loug  time,  for  ninny  houn  lu  fact,  «noc  in  thvse  theaauie  bulk 
of  blood  ia  expiKted  to  the  iulluence  nf,  and  reciprocally  exerta  an  influenty 
on,  a  larger  surface  of  the  viucutar  walU  ilmn  in  the  larger  venela.  And 
If  il  be  urged  that  the  re.iiiU  i.i  here  dui?  In  iiillui^nceo  exerted  br  tbc  bodi 
at  large,  by  the  tiasuM  us  well  ai>  by  the  viweular  wallit,  thin  objection  ~* 
not  bold  good  agaiDHl  the  fiillon'iag  exiicriinont. 

If  tbe  jugular  vein  of  a  lurg<!  aDiinal,  such  a«  an  ox  or  horse,  Iw  carefil 
ligalured  wneii  full  of  hlooil,  and  thu  ligatun-d  portion  cxdwil,  the  blj 
iu  many  caiHSt  remaimt  perfectly  fluid,  along  thr  greater  part  of  the  len^ 
of  the  piece,  for  twenty-four  or  oven  forly-dght  liours.  The  piece  so  liga- 
tured mav  be  eu«pcndcd  in  a  framework  and  opened  at  the  top  so  as  lo  imi- 
tate a  living  t(»t-tube,  and  yet  the  blood  will  ol\cn  remain  lone  fluid,  though 
a  portion  amoved  at  any  time  into  a  glass  or  other  ve&#el  will  clot  in  a  few 
mmutes.  If  tiro  such  living  teet-uibcs  be  prepared,  the  blood  may  be  poured 
from  one  to  the  other  without  clotting  takin;;  place. 

A  simitar  relation  of  the  fluid  to  its  coniainin;;  living  wall  is  seeil  io  tbe 
case  of  those  serou*  fluids  which  clot  spontaneously.  If,  oa  soon  after  death 
as  tbe  body  i*  coid  and  the  fat  is  solidified,  the  t>ericardium  be  carefully  re- 
moved fVotn  asbeep  by  an  incision  round  the  base  of  the  heart,  (be  pericardial 
fluid  (which,  as  we  ha>-e  already  seen,  during  life,  and  some  little  time  after 
death,  posacBsea  the  power  of  dotting^  may  be  kept  in  the  pericardial  bag  a* 


THE   CtOTTIN'O   OF   BI.OOD. 


68 


te  >  livioft  Clip  for  Riauy  boiin  wiiiioul  ilottiiif;,  utA  yet  a  iihaJI  porti»u  re- 
Bomil  mtli  n  |>i]>ette  rlols  st  once. 

Tkti  rvlKiioti  brinu-ii  tli«  IiIimmI  ami  the  vasculur  wnll  may  be  dialiirheil 
or  ovcniiMf-n :  cluilitii;  nmy  tiike  place  or  may  be  induced  niiliiii  itie  livluj; 
Uoodtv**!.  WIm'ii  iliu  liDiriK  uiviiitiiuD«  »  injured,  n«  irkeit  nil  arury  or 
win  h  ihsrply  lii;iil<in-il,  >jr  wlivu  it  w  diceaKd.  tu  fur  iDHtaiicc  in  Biieurwro, 
•  dot  i*  *\'l  lo  bv  li<riiiiH]  at  ibo  injured  ur  diM-tiH-tl  sixil ;  kikI  in  ccruin 
■oririd  eoodilioiM  of  the  body  eUitf  arr  r»rRi<s)  in  rani>uii  vaiwular  UitcU. 
AlnmeB  of  iBntion,  «hioh  in  vhtil  I>Iimh1  ii»  w  Imvc  »«en,  i«  unfuvorahic  to 
dattiiag,  1*  apt  "ilhtn  tlH<  bo>ly  tu  knd  h>  plotting.  Thiu,  uhen  iiti  nrlcry 
b  HpUnrrd,  tlic  blwid  in  lli«  tnct  of  llie  arlvry  on  the  curdini:  nidi;  of  the 
S|Uan>,  bolwcf'n  tbt>  iigaluir  aul  (hr  hninoli  Wt  givvn  citT  by  lh«  tirlcry, 
amtkof'  to  iban  in  tbv  circulation,  rvmaiuv  ingticinlcm  or  iKarly  ao,  aiid 
•Img  thb  tract  a  clot  (nrta%,  linni.-*t  nvxt  ti>  lli«  ligiiiure  nod  eoding  atmr 
■ban  iIm  branch  i»  given  off:  thii>  twrhap*  may  hv  cxplitincd  by  the  fact 
that  tba  walls  of  the  irsrt  Kiiflcr  in  rlicir  nutrition  by  Ihr  rtagnaiion  of  tJi« 
blood.  Ktwl  itial  cuQMqiHiilly  the  Dornial  relutioD  between  thcoi  and  the  cod- 
Uiaad  t>['-»l  is  dialurmd. 

Tbat  th«  blood  within  tlie  liring  hloodrcaacb,  though  not  actually  dolling 
nadar  DoraMtl  circuniKtanix.-^.  uiuy  cwily  be  made  to  o(ot.  Dint  the  blood  is, 
:.  av  t«  malt,  always  on  the  point  of  cloitiDK.  u  shown  by  llie  fact 
fonign  body,  nieli  as  a  oeedle  thrust  into  the  interior  ufa  bioodrnael 
fvad  drawn  lbrou;!h  amt  li-A  iu  a  Idoodvcaial.  is  apt  to  becoma  cot- 
«ilb  fibrin.     .Sotoo  influence  exer(e>I  by  tli«  needle  or  thread,  whatever 
ba  the  cfaiinu:tor  of  lliat  iofluence,  i»  sulHcienl  to  deteriuine  a  cloiliu);, 
Mbcfwite.  would  licit  have  taken  plaee. 

«a»c  iiutakiliir  of  the  hliHxl,  as  regarda  clotliu^',  is  strikinjciy  shown, 
caM  of  Iho  ra1il)it  nt  least,  br  the  rtsiilt  of  injttcline  into  tlic  blooil- 
a  snuill  ijuantity  of  a  solution  of  a  peculiar  proteid,  prOMired  from 
•truotun*  such  us  the  tbymiis  body.     Masiive  clotting  or  th«  blood 
iMt  all    the   blmxlveAsels.  snmll  and    large.  takc«  place  with  great 
y,  iMdinjc  to  the  »iddcn  death  of  the  animal.     In  cotilnut  to  this 
may  br  nwnti'Mied  (he  mull  of  iiijectin);  inio  the  bloodvessels  of  a  dotf 
qitaulitr   "f  u  tohitioD  of  a  body    called    albtimote,  of  which  we  shall 
h^wUrr  linve  lo  trnit  ns  a  product  of  ihe  dif^Uoo  of  proteid  sufaMancca. 
aatent  nf  (>M  jcTammc  |ier  kilo  of  body  weight.     So  far  fmio  priKluc- 
tiog,  Ihe  injcrlfd  nititinione  has  such  an  e^t  on  the  blood  thai  for 
houn  KJVr  ihi-  iiiictioD  shed  blood  will  refuse  to  cl»l  of  itself  and 
D  quilfi  fluid,  Uiou)(h  it  can  bo  made  to  clot  by  sjieciul  Ireatnicnl. 
SS.  All  thi-  forevoing  fiwta  tend  to  ohon'  that  the  blood  as  it  is  flowing 
the  htwlihy^loodvcanla  (■,  a*  far  aa  •■lotting  is  oonccroed,  in  a  state 
wguililiriutu,  which  mar  nt  any  inonK'nt  bn  uirvt ;  even  within 
lv«ael»,  iiu'l  which  is  upnet  directly  the  blood  i*  nWil.  with  clotiing 
ramiL     Our  pmteiit  knuwl<><Ige  does  not  itenuit  ii*  to  make  an  authori- 
alatemeol  n»  lo  the  vxttvl  naluni  of  this  etjuilibriuni.    There  are  rea- 
however,  for  thinking  ihnl  the  white  oorpuwU'w  play  lui  ini{ioritinl 
ki  the  tnattrr.     Wlimtver  cJuiiiDg  occurs  natumlly,  whitv  corpuscles 
I :  and  ihiu  is  true  not  only  of  blood  but  also  of  such  spocimena 
dial  or  other  serous  lluids  as  clot  niilurally.     Wlten  horse's  blood 
kept  fluid  by  luHnf;  relaineHl  within  the  jugular  rein,  lU  menliomd  a  llttla 
V  bock,  and  the  vein  is  hung  upright,  the  oonMiscka,  both  r«d  and  while, 
.,  leaving  an  u|-|K-r  laver  nf  plik^nia  almost  rrae  from  oorpuacles.    Thia 
ar  layer  will  l>e  foun<l  to  hare  lost  largely  its  power  of  clotting  spon- 
■ly,  though  iho  |iotier  Ii  at  once  refined  if  the  white  c>r|itiscla  from 
layrr*  beneath  be  relumed  to  lU     And  many  other  argunKnts,  which 


■bike  I 


MM  If  If.  I 
UW  Uyrn  1 


A 


the 


all  pcimrin^  lo  the  oaine  con- 
iinpuriai)t  juirl  iti  lUe  promss  of 


u'e  cannot  enter  upon  here,  mny  he  ndduced  all 
rluHiim,  thai  the  wiiiie  enrpuBcles  play  an        _  ^ 

clotting.  Jliit  it  uoiili]  lead  ua  tix>  tar  into  L-i>ntravertaaI  matten  lo  atleiiipt 
to  define  what  that  jmrt  ia,  or  to  explain  the  exact  nature  of  the  equilibrium 
of  wbidt  vc  have  anakeu,  or  to  diacuBS  such  <|uciitiiMi8  aa :  Whether  ib«  ordi- 
nary whit«  ei^r[iu*u[ea,  or  corpusolw  of  a  s|»et:ial  kind  are  cunccnicd  in  iW 
malterf  Whether  th«  oorpiiscles,  when  cloltine  taka  place,  e.^.,  fibrin- 
ogon  or  fi^rmeiit  or  both  oraomeihiiiK  else,  or  whether  the  onq>ilwIcii  »im- 
ply  in  womw  way  or  other  Hfsiitl  in  the  tmnnformnlii'in  of  .iOmo  prwiou*tj 
«jci»tiD]{  w>ii»litn«DU  of  ihc  plaiMDa?  Whethi^r  the  influenoo  exerted  by  tbc 
condition  of  (be  va»cii]nr  wall  it  exerted  dirwctly  on  the  plunma  or  indi- 
rectly on  the  corpuscle*?  Wlicihitr.  u  •ome  htive  ihoughr.  iliv  pcailiar 
bodie*.  of  which  w(!  shall  presently  upcsk  under  tJic  namo  nf  blood  plaleJete 
or  pia^uet,  hare  any  share  in  the  matter,  and  if  tra  what?  Th<««  que^iionB 
ar«  too  involved  and  the  discuwinu  of  thcni  too  long  to  ho  entered  upon  hero. 
What  we  do  know  thnt  in  blood  soon  aftor  it  has  been  elied.  the  body 
which  we  havo  called  fibrinogen  \t  present  a»  also  the  body  which  we  have 
called  fibrin  ferment,  that  the  lutter  actlnj;  on  the  forni>!r  will  produce 
fibrin,  and  that  the  appearance  of  Hhrin  is  undoubtedly  the  csu<e  of  what 
is  called  clotting.  Wfl  Beem  ju^litied  in  coticlitding  that  the  clotting  of  abed 
blood  ifl  due  to  the  ConrerHion  by  ferment  of  tibrinogeii  into  fibrin.  The 
furl  her  inlereiice  that  dotting  within  the  bmly  is  the  same  thing  as  clotting 
outside  the  body,  and  stmiUmy  due  to  the  trans  for  ion  tion  of  fihrinoji^u  by 
ferment  into  librin,  though  protMble,  la  not  proveil.  We  do  not  yet  know  thiB 
exact  nature  and  cundition  of  the  blood  within  the  livio);  bloodve«itla.  hd^B 
until  we  kudw  that  no  cimnot  nit ii»ftiut only  explain  wliy  htuod  in  the  living 
bloodveMelgi  is  iifiiallv  lliiid  hut  can  at  linuw  clot. 


The  Coi{i'i,'H(;i.iw  or  thi:  B1.0011. 
Tlie  Rfil  CorpMdf*. 

§  34.  Tlie  redneM  of  blood  is  due  exclusively  to  the  red  corpuaclea. 
plasma  a*  K«en  in  thin  layers  within  the  living  bloodvnaeU  appenn  rolor)<4«, 
Bsdoe*  a)M)a  thin  layerof  serum :  but  a  thick  layer  of  serum  (and  probsbty 
of  plattnm)  Iibh  a  faint  yellowish  tinge  due,  as  vre  have  said,  to  the  prcMnoo 
of  a  small  ipiantity  of  a  sfteml  pioiuMit. 

The  OorpusclM  appear  under  the  niicroM!0[H-  a*  fairly  horaogVQKHi*.  im* 
perfectly  traiwluccnt  biconcave  dLir*  with  a  diameter  of  7  to  A  yi  and  a  thick- 
neaa  of  I  to  2  />.  Bdng  dine*  they  arc  circulnr  in  outline  when  seen  on  the 
flat,  but  rodxhajmc!  when  »neii  in  prolilf  tus  thny  arc  liirntng  over.  [Fig.  'p. J 
Bdng  biconcAvc,  with  n  thicker  roiindM  rim  surrounding  ■  thinner  centre. 
the  rays  of  li^ht  in  piu«iing  thn)ugli  ilicm,  when  they  are  examioexl  by 
transmitted  It^ht,  arr^  more  n^fracled  at  the  nm  than  in  the  centre.  The 
etiect  of  thii>  i>>  that,  when  viewed  at  what  may  ho  considered  ihe  proper 
focUH,  the  centre  of  a  coqiusclc  np|>cnra  clear,  while  a  eliijht  opacity  mark* 
out  indinlinclly  the  inner  mnrgiti  uf  the  thicker  rim,  whereas,  when  ilie  foc-us 
is  shiAe<I  either  up  or  down,  the  centre  becomes  dark  and  the  rest  of  the 
corpuscle  clear.  Any  body  of  the  same  shape,  aud  composed  of  substanoe 
of  the  same  refractive  power,  would  produce  the  same  optical  eAeolS.  Other- 
wtw  the  corpuscle  appears  homogeneous,  without  distinction  of  part*  and 
without  a  nucleus.  A  single  corpuj«cIe  seen  by  iwelf  has  a  very  faint  cohir,^ 
looking  yellow  rather  than  red,  but  when  sevcml  corpuscles  lie  one  upon  tk 
top  of  t^e  other  die  miuu  is  disiinelJy  red. 


TIIK   COHPUacLKS   vr  THK    Dl.OOb. 


&s 


Tb«  f*d  corpuscle  i»  i-lftstic,  in  the  kdik  ibat  it  tstny  be  deforitied  lij 
ptamni  or  tnctloo,  bul  wlieo  Uie  pnasun;  ur  tni(-ii<>n  in  removed  rogaiai  iu 
pnviiMn  fbnn.     lt»  shape  b  also  touch  inHiiviii-t'd  bv  tbi;  phyncal  condilioM 


I 


irw.». 


Fio.a. 


fh).  9l— NcsikS  IhJinli  ^  ma  u>  Hit  VTini)  «tiiiK.  lUniiiiIDO'l  atoHit  IMDdlUBtUnkI 

I    I    Itmfh  Urt  IMI I IjlUKlUi,  r.r;  rvnliviiinwlcion  (belt  odc« UMl  rttwol  tli  t*alU*l 

'•,  mA  iMiBwtlti  ■n«niid  in  roulawii;  r.r.crmUc  iwl  cvrinMiln:  p,  ■  HMty  B'<»i>l'>r  I*!"  *•"• 
tm^t .  9,  •  nanvlf  (M»al*r  p*te  <«ir|iaKlP.    U-db  liarn  txu  uf  Ihitw  dliUnol  ncinln.  nod  *cfw 
wAnaoUit  cbaii^M  •>(  (hatB  at  lira  iDM»iri  of  •it'wfTiilkia  ^  ill  p  ■  tiuclcoa  tim  turn  rlilbUt. 
r>>  d-lliat.i  Kiti  cuHi^-nuu.  I.iin-.  !<t!i»LY  u<»'»i.unn>  Drm  Iumia    (At  wmsnderM 
Witi  ^w*r  at  Iha  nucrnBM)!*.  i  ] 


If 


irxi  I. 


8 


«f  tlMpla«Bm,Mrum.wrllui(l  in  which  firthi-  limo  being  it  i*.     If  tbe  {ilnsma 

«r  Ptmtn  be  diliihs]  with  water,  the  ilisc.  ulMi>rliin^  wiiler,  fniKlln  u|i  inl»  ii 

*pb«n>  [V\f.  *}].  becoming  a  disc  n|;tiiii  on  tbe  rciDOTsi  ol'  the  dilution.     " 

iMMTUm   be  coocentraied,  the  disc,  |>ivint;  out 

nl«r.  shrinks  imgubrly  and  aBsunrcs  vaH'xi* 

(^•rcM;  <)D(!  of  thcM  fornu  is  Ibsl  of  a  nuMilx-r 

of  Uodttd   |>MlubeTauu»i    pruimiin;;    ail   uvcr 

iW  Mirfiue  uf  tbe  t;ijrf>UH:lv,  wliifh  is  then  said 

%m  b*  crvnKte;  in  n  drop  of  blood  (.-xamined 

HMler  tlw  niurosopt',  vrenale  mrpiiM^'les  are 

«Aaa  aeeo  at  ihi-  nl^ie  of  the  cover  nlip  where 

«<npmii(iD  i»  leadins  li>  ronocn  I  ration  Df  the 

ptoawK,  or,  U  it  stuKifd  tWn   |H-r)in|M  rather  be 

called,  (Wiiro.     In  hlooU  jiut  ahrd  tlw  ml  cor- 

pnadM  arv  a|it  In  adhere  to  each  iitli«r  hr  iheir 

^,   .^^,,.^_  much  more  than  tt>  the  giiMi  or 

Hti  ■'  with  which  the  blood  ia  in  rontaci,  and  henoo  arrange  tbemMlTei 

ht  roll*      riiif  tendency,  howevar,  to  fiino  n>lla  very  etxin  diminishe*  nfUr  the 

blood  bihiMl. 


8  8 


4        t 

oo 


o-f,  >iici«ari*«  eilbtt*  "X  water 
ii|>iu  ■  ivl  (orpiuota:  /  <tlR«i  '4 
•uliitlna  uf  ibI(.  cniiutcd  :  f,  vllbft 
of  Waiiie  Kid.) 


Tbouli  n  •iii^lp  ri>rj>iiwl4-  '\*  Hinn-nrhal  trniuliiceDti  a  coniparalirely  thin 
kjvr  M  klotid  \»  <>|iiu)iip  ;  tvjH-.  for  iiiKiance,  cwtnoi  be  mtd  tKrough  eraD  ft 


IMCl 

thin  Uf  ar  of  blood. 

WlwR  a  i)uantitr  of  whipiiud  hlood  (or  blooil  otborwiM  depnved  uf  fihrio) 
ia  frvMO  ud  ihawi-d  Mvend  limes  ii  ehangea  eoJor,  bocuming  of  a  darker 


66 


ii3- 

inuP 


hiio,  iiml  if  tbrn  rotind  lo  l>c  niiicb  nioic  tninKparrnt.  *o  i)iot  ivfx-  win  roir 
b«  irn»ily  rvii't  tlinxigh  n  niu<l«rnU-lv  Ihin  luycr.  Il  u  then  ^fmlcrn  of  u 
iahfhiood.  The  winiv  rhniigo  niuy  lie  cflrctoil  by  »hiiking  ihp  blood  with 
ether,  or  by  ad(lin<'  n  smnll  <|iiRntily  r>f  bill-  snll^  and  iii  other  wnyi!.  Vikki 
cxaminaliou  of  laky  blood  il  is  fouiii)  tbnt  the  rr<t  oorpuroles  nre  "  brolcni 
np  "  or  al  li^asl  altered,  and  ihtit  the  rcdnns  nhk'h  nrvviiituly  was  oonlinrd 
to  tbem  ia  now  diffused  [broiii^h  the  Minini.  Normal  blood  is  opaque  bveauat 
each  corpiiEcle,  while  pcrniiUiiie  tome  mya  of  light  (etiielly  r«d)  to  oaa 
ihrougb,  refteclB  iiiaoy  otbers.  and  the  brigbliieM  of  the  hue  of  Donutil  blood 
»  due  lo  ihis  reHeclioii  of  liiihl  Iroin  the  «iirfiiceB  of  the  several  corpusoltt. 
I^ky  blood  ifl  traiisnareut  because  there  are  no  longer  inlact  corpufo)«*to 
preseut  Burfacn  fur  tlie  rellec-iioo  oT  light,  aod  the  darker  hue  of  laky  blood 
u  (iinilarlr  due  to  the  uttsfuce  of  reflecliun  from  the  several  ci-irpusclee. 

Wbeo  laky  blooil  is  allowed  to  atand  a  sedinieut  is  tbrmed  (and  may  be 
Mparated  bv  ibe  centrifu);ul  machiue)  ivhich  on  examinaliou  is  found  to 
conpist  of  dUcK,  or  frKftnieiiLt  of  iWws,  of  n  colorlew  auhstiince  exhibiting 
under  hi^h  power*  an  olweun-ly  Kpoiijiy  or  reticular  structure^  These  cotor- 
lof^,  thin  ili»('K  MTii  HuI-ivim;  ofirii  appear  a»  mere  rings.  The  aubstancfl 
oonii><i»ing  them  »tiiiii:<  wit)i  vurioun  rt*ag('iiti'  and  may  tlius  be  made  tDure 
evident.  jfl 

1'hu  rrd  corpuscle,  then,  con»i»ta  obviously  of  a  ooUiriut  frainontirk,  wIhB 
which  in  nortnsl  conditioiii;  n  red  coloring  matter  is  tURiciaU-d;  but  bjr 
various  means  the  coloring  matter  may  bv  driven  from  the  framework 
dissolved  in  the  serum. 

The  framework  is  spoken  of  se  ^rtmo :  it  is  n  modified  or  dilTereutinl 
protoplasm,  and  upon  chemical  analyeia  yields  proteid  suhftunceis  some  of 
them  at  least  belonging  to  llic  t/lohvlin  group,  and  olher  matters,  amoog 
vbichis  a  peculiar  complex  fat  called /nrMm,  of  which  we  shall  have  tospeatc 
In  treating  of  nervoua  tissue.  In  Ihe  nuclt-ated  led  corpuscles  of  the  lower 
vrrichraln  this  difl^utiated  ulroma,  though  forniiufi;  the  chief  part  of  the 
celMiriily  aniuud  the  nucleus,  is  accompanied  by  a  variable  amount  of  undif- 
fenniinied  protoj>laMii.  but  the  latter  in  ihe  miimmalian  iv<l  corixisele  b 
either  aWnl  nllo^lher  or  n-diiced  to  a  minimum.  Whethi'r  any  part  of 
this  stroma  is  living,  in  the  scnsi-  of  being  ctijrmbleof  carryineon  a  continual 
double  chemical  chang*.-,  of  i-onliuunlly  buili^ng  itself  up  as  it  breaks  dowiH 
il  a  qiieflion  too  liitliaill  to  he  <lii'ciin>ed  hcnr.  ■ 

The  red  coloring  matter  which  in  normal  conditions  i»  associali-il  with  thi» 
Stroma  may  by  nppTopriotc  means  be  isolutcti.  and,  in  iho  case  of  ihv  Mood 
of  many  auirosls,  obtained  in  a  crystalline  form.  It  is  called  hirmaghbiti, 
and  may  by  proper  methods  be  split  up  into  a  pruleid  belonging  to  the 
globulin  croup,  and  into  a  colored  pigment,  coniaiuing  iron,  ctdle<l  nirmatin, 
nsenioglobin  la,  therefore,  a  very  complejc  body.  Il  is  found  to  have  remarlt- 
mbl«  relations  to  oxygen,  and  indeed,  as  we  shall  see,  the  red  corpuscles  by 
virtue  of  their  hiemoglobin  have  a  sjiecial  work  in  respiration  ;  they  cany 
oxygen  from  the  lunga  to  the  several  tittuei*.  We  »faall  therefore  defer  the 
furtliir  study  of  birmoglobin  until  ne  have  lo  deal  mith  respiration. 

Tbo  red  corpuscle,  ihrn,  con»i»t»  of  u  ilinc  of  colorkrs  stroma  with  which 
is  acaociated  in  u  prculinr  way  the  complex  colored  btidy  haimoglobin. 
Thongh  the  hamocti-bin.  an  in  >ecn  in  laky  l)lood,  ts  readily  Mduble  in  serum 
(and  tl  is  nUo  soluble  in  pliisnm),  in  the  intact  normal  blood  it  rcmaJus  eou- 
fined  to  the  corpuscle;  obvitiuiily  there  is  Home  special  connection  between 
theatroroa  and  the  btenioglobin;  tl  is  not  until  the  Tlromn  is  altered,  we  may 
perhaps  say  kille<l  (ns  by  repeuted  frci-zing  nnd  thawing),  that  il  kwfl  its  liold 
on  the  hx'm<>>;l<>hiu,  which  thus  set  free  passes  int"  solution  in  theacrtim. 
The  dbc  of  stroma  when  separated  from  [be  bicmoglobin  ha«.aEweharcJi 


THE    CORPUSCLES    OP    THK    DLOOP. 


sr 


«U.  an  ot»eurclir  «iH>ne%-  Uixturp ;  but  w«  ')»  ool  know  aocuralcty  th«  cxscl 
eowliUnn  of  lbi>  Nlffuit  in  the  iiitacl  oonxiKlo  nr  how  it  holde  thi>  hiemo- 
sloUa.  Tlwn  b  nrluinly  poilvliniu-  mi'inhniiK;  nr envelope  to  lltcGornugcIc, 
nr  b]r  expoung  bliM>il  toabigli  lemin-nittin!.  tU>°  ('.,  the  oorpuBole  will  break 
apialoil>on4>rlcMs|>bmciil  pientt.eiich  still  i.xitii>itlin);ijf  Mroinaatld  b»RiO- 


Tbtt  qouitily  of  nromn  ncccsMrv  to  hold  a  qiiuoiiiir  of  lunooglobiti  w 
«ac«T<iit)p1y  small.    Of  ili«  total  Boliit  inaticr  of  a  corpu»d«  tuon  than  90 

Cr  cent  '»  luFtnoglolHii.  A  red  comiMrle  in  fad  is  a  ijiiantity  of  hieniouloliin 
U  (ogvther  id  the  form  of  a  dbc  by  a  rainiinal  ainntiiit  of  itroma.  lience 
wb»l«T«r  fflK;t  ihtt  stroow  per  te  may  have  u^ii  the  plasma,  this,  io  the 
ease  of  manuuala  at  all  ereuti,  muu  be  iiui(,'mticaiit ;  Ihe  red  corpuscle  is 
pcactirallr  Rtniply  a  carrier  of  hieinoirlubiti. 

i  SS.  "file  avemgie  number  of  rvd  ci>r|ftiicl«a  in  hiinian  blood  may  be 
probsUjr  put  down  at  about  5  millioitu  in  a  cubic  niillim(4re  (tli«  mn^  in 
diflcnal  ntauimals  i«  mid  to  be  from  '-i  tu  18  milltoii*),  hut  the  relation  of 
eariNHol*  to  nlaama  Tarin  a  good  deal  evi-n  in  hralih.  nnd  very  much  in 
dinw^  ObriuutlT  tba  relation  may  be  allwicd  ( 1 )  by  mi  iiitn-nim  nr  decnaae 
of  tba  pliRnn,  1 2>  by  iin  net  mil  decrcaieoriacmucof  red  oorpiisrlr*.  Now,  iliv 
fcrSMT  nuM  rmiucnljy  take  nlacc  The  blood,  as  ire  have  nln-mly  iir){i.'d,  is 
always  bring  acted  upnn  by  changm  in  the  timie*  nn<l.  indccl,  h  nn  itidi^s  df 
thomt  ehangn :  bCDCv  the  puiMmi  tniiet  l>e  «>iiliniially  chnnging.  though  atwAVN 
sUiviiW  III  n-luro  to  the  nurmni  L-oiiditioti.  Thus  irhcn  a  Inr^-r  >jiiiiiilily  of 
wmtar  b  •lischareeil  by  the  kidney,  the  skin  or  the  tK>wols,  ttint  water  citncs 
rvmflv  from  the  filtMo),  iim)  tho  drain  of  water  must  tend  to  diminish  ihn  bulk 
iif  tDO  plosniii,  anil  ri  to  increase  the  '•eialiit  number  of  red  corj>iiscU')i, 
tbmigh  tlir  etftfct  is  pmbnbly  mod  remedied  by  the  |iaf«a^  of  natcr  from  the 
tiiauf*  ititii  the  blixxl.  Ho  ai^ain  when  ii  Inr)^  i^unntity  of  water  is  drunk, 
tbia  piwrs  iniu  the  blood  nuil  li-nil.->  lempDmrily  lo  dilute  ibe  ulasraa  (and  so 
to  dimiaish  the  ntniivc  nuinWr  nf  red  oorpunclev),  iboufch  tbii  ooiKlition  ia 
ia  tnni  snuu  rf'a>edir<l  byihe|<a»>iigeof  tbeauperfluAiu>  fluid  to  tbu  ItMuea  aiMl 
axcrrtury  organs.  The  greater  or  liw  number  of  red  curpuide*.  tiKn,  in  a 
fhren  bulk  of  blood  may  be  >iiuply  duo  to  Iimi  or  mnn^  pla«ma,  Init  we  have 
rraaoo  tu  think  tluil  tbe  iictiml  nuiuhor  of  ih*-  eorpiiM'hv  in  iIh-  blomi  does 
Tan^  fmra  lin>c  tu  liuH-.  Thi>  in  rr-|>i.-cially  m-cu  to  t-ortain  formii  of  disease 
abieh  may  bo  spoken  of  under  tho  geneml  k-nn  of  anicmiii  AWri!  being 
Mveral  kiuils  of  aoatmiai.  in  which  the  number  of  red  corpuscla  is  dislincUy 
(Uslatilicd. 

Tba  rtdorsa  uf  blood  mny.  hone^'er,  be  Influenced  not  only  by  tW  uuml>er 
af  red  corpuscles  in  each  cubic  millimetre  of  blocMl,  but  also  by  tlic  amount 
af  haaM)|[lobin  in  eneh  corpurele.  and  to  a  le»  degree  by  tlie  siio  of  llie 
rorpBSCWS.  If  we  compare,  nilb  a  common  standard,  the  rednMs  I'f  two 
wpmtbamat  of  blood  unequally  red,  and  then  determine  tlw  relative  numU'r 
irt  oorpuaclta  in  each,  we  may  And  that  tbe  len  red  specimen  has  u  many 
rorposclr*  as  the  nilder  one.  or  at  least  the  deflcieocy  in  redness  is  grtMcr 
than  can  Ik-  accounted  for  by  llw  [inudty  of  n-d  corpuscles.  Obviously,  in 
socb  a  cw,  the  ml  corpuscles  have  too  little  ha-movl«bin.  In  Mme  coaea  of 
Boamia  ibe  dcKcicncv  nf  binnnglubin  in  each  corpuscle  a  more  Mriking 
tbaa  tba  acantincM  of  red  cuq>u8c)ca. 

Tb*  aDiulirr  at  (orpowln  in  ■  specimen  of  t>lo<Ml  U  dctetminH  by  mlalng  a 
Maall  but  carriulty  meaiiurtd  <iu»iitiiv  of  the  blond  with  a  Inrjce  <|iiantity  of  some 
iadiAravnt  Auid.  f.y,,  a  A  per  ceiil.  soliiiion  of  tiiillum  »ii1]i|iiit^.  nnil  then  uclunlly 
cowntiag  Ihr.  corpii*olr^  In  a  kn'>Hii  iiiiindiiiil  Imlk  of  ttie  mixture, 

'  ,  pcfbaii",  may  b«  mmt  ci-nvcuii'otly  done  by  Ihi-  itii'ilmil  gcoerally  known 


^^U^P 


DLOOD. 

■*  iluit  of  iiuwen  {HKtBKicjUMattet)  [Fig.  $}.  ltnproT«tl  b;  Maluwa.  A  glan 
bII<1«,  1b  •  m«uJ  rnun«,  ii  rwtd  into  minute  rM:Ui»t«>,  •■.  y..  \  mni.  Ii^  |  mm.,  m 
H  toglvf  &conT«nl«Dt«mof  Aof  o*n""^  ■"■"-  ThrrcuiuUI  x^vm  in  thernm* 
paraitt  a  novcralip  to  ht  bratiftbl  to  ■  fixnd  diatnnce,  <-  9.  i  inni..  from  the  Nuifaoe 
oflbraliilc.  Tb«  blood  bavinr  b«4i  diloinl.f.^.  tu  lUO  iiin«*  itn  ralonie,  •  amall 
iiuikntiljr  of  die  dtloieil  ^«Dtl  tburuusbl}'  mlivai  blood,  iofflctent  to  occap.v  fully 
UM  ■pftM  between  tbe  eurenhp  aiM  the  glaaa  alidfi  whed  lh«  formrr  i*  brouEht 
lolia  properpOililMi.ia  placed  on  tti«al>ile,«tid  the  oovenlip  broaght  dowa.    Tb« 

trw.  a. 


U» 


d 


A  liHWllbt  ■Wurtot  Uw  iHlWlin  mliiitan;  fl.  oiJlltJT  kiIr  foi  <.>  ..- irL.v  ),1:m>1;  c.  mil 
allb  OlTtiluni  on  *Me,  mv««ittuB  uid  upAiup:  D,  rami  (ob^i  iiilucliiiit.  ^  inlxtri  P,  siMrdnl 
■■•Mr'podnti-l  iiordls  fOrMlcilnxBniKV.) 

rolumoordiliitod  blood  now  lying  over  «acli  ortfafirfctaneliw  Kill  be  1)9  I  ^  X' J) 
of  m  cubic  mm. ;  and  if,  wb*ii  thr<  i">r|HiM;lM  have  ftulMiik-d,  ll»  number  uf  cur< 
piuelM  lyinn  within  ■  recungte  be  L-oLinto'l,  the  roHuli  irill  cive  the  number  of 
cnriKuclM  pievioualy  dlslrltiuted  through  tJo  of  a  cubic  mm.  of  the  diluted  blood. 
'riiiH  mullipliwi  by  lOU  will  give  the  nnmber  of  rorpa»clM  in  I  cubic  miu.  of  l)i« 
dilutetl  blood,  and  wain  iDultipHnl  by  lOO  tho  number  in  1  cubic  mm.  of  ihr  <>ntiro 
blood.  Il  io  advinibtn  lit  count  lli«  Dumber  of  cofpuMle*  in  iier«nil  of  lb»  rr«- 
tKDglM,  ami  to  lake  ibe  average.  Fur  the  c(tDveui«nce  of  counting,  each  mtansle 
la  aubdivided  Into  n  number  of  verv  amall  aquaroi,  r,  y.  into  30.  t»eb  wtUi  a  aide 
of  Jk  mm  .  Hiid  DO  an  nrea  of  ,Jlg  or  a  aqnarv  mm. 

Siner  (Iw  actual  numlier  of  tM  cnr{Hi»cle«  in  1  specimon  of  bloiMl  (irlilcli 
may  be  tjiken  lu  u  Ntm|)U-  of  ihi;  whol«  blood)  tssomelime*  more,  aomctinxM 
len,  it  is  i^bviouH  that  either  n-d  (.'orpuwtea  may  be  teRi|><>ninlv' withdrawn 
from  and  relunivd  to  the  grncnil  blood  current,  or  that  certain  re<l  corjmHctea 
are,  aA«r  a  while,  matlo  uwajr  wilh.iuid  that  iiea'  oiiim  ttiko  thi-ir  place,  We 
have  no  aatieficlory  cvitk-noe  of  the  former  heint;  the  ca»o  in  normal  condi- 
tions, wbereait  we  bavo  evidence  that  old  cor|>u<clM  do  ilio  and  thnt  new  ones 
nre  bnrn. 

^86.  Th«  red  oorpmclee,  we  have  already  siiid,  arc  cyiiitinuully  en-fa;;ed 
in  carrying  o»yj[e«,  by  moans  of  their  batmoglobiii.  fnno  the  long*  to  the 
liaauea;  tlie^  load  l)i«mBelvea  with  oxyK«n  at  lh«  luiiii*  and  nnloiid  at  th« 
tlMUCS.    ll  u  extremely  unlikely  that  tbia  act  should  be  rvpoated  indeliHltely 


rnt  coRpracLcs  or  rnic  blood. 


fi» 


I 


villtfKit  leoilins  t»  chkOfrefl  irhicti  may  be  fiiniiliarly  described  lu  w«ar  aud 
taar.  nntl  wtiii:!)  woub)  ulLintalely  leni)  to  the  denili  ut  t\\^  turpiisclw. 

Wfr  ftbull  hrtve  lu  stale  Inter  oti  thnl  ibe  liver  didcliaripa  into  the  nlinien- 
tmtj  ivnal,  lu  a  conMiiucut  of  biU'.  a  (Nminiderttble  ((uaiility  ul'  a  pit;n)vnt 
knnwn  n»  fiUirttbiH.  and  tliat  thin  iiuhi>iauoe  liiu  tvuiarksble  rolatioiu  with, 
»'■  I.  majr  he  rcKiinieti  as  a  derivative  of  Acmwi/ui,  wUicb,  as  w«  bav« 

•r<  .  •  ,  ii  a  prciiliK-t  of  th«  deoompotitioii  of  hn»uoglobui.     It  appcan 

)«T>faabl«.  ID  flirt,  that  ttic  hilinibfn  of  bile  I  aud  thin  ii»  vtir  nUall  woe  i*  Iba 
ctilrf  biltarr  |iif(UH'iil,  hihI  ih^  source  of  the  ntlicr  liilinry  pifjnicnls)  is  not 
fonnnl  wbollr  nin-w  in  tix^  budv,  but  id  maiitifucturtHl  ia  w>inc  ituy  ur  oilier 
ODt  nf  lueuiatiii  derived  from  liiuii(>gli>biu.  Tbt»  mtuil  cfiUiil  n  diiiljr  onn- 
•anptioB  of  a  consiik'ntblo  minntilr  <>f  hienioglobiii,  and,  »inec  ivc  kiiov,-  no 
Other  sourt*  of  bHtuogtobin  besides  Uio  red  corpuocW,  and  have  no  uvidutiuu 
of  rrd  eorpusclflt  coDtinutne  to  exist  after  having  lost  their  hemoglobin, 
(Diut,  Iherefiirc,  entail  a  daily  deatniction  of  mnny  r«d  vorpusclec. 

Eveo  in  health,  then,  n  number  of  red  oorputcJes  miut  be  continually 
duppearinj; ;  and  in  diseaM  the  rapid  and  f;rent  dimtmitinn  which  may 
take  place  in  the  ntiniber  of  red  corpusctea  »Iiowb  that  large  destruction 
aWTOcnir. 

We  cannot  at  present  accurately  trace  out  the  steps  of  this  disappearance 
of  red  eorpusclca.  In  lli«  spleen  pulp,  re<l  curpuscles  have  been  seen  id 
varioua  wiMgn  of  disorganiiation.  m>iuu  of  them  lying  within  the  suhetaiwe 
of  Urge  coRirleflB  mrpuscles,  aud  as  ii  iT«re  beinj;  eau-n  by  them.  There  is 
alsoerMence  that  deatruction  takes  place  in  lb«  liver  itMlf,  and.  indeed, 
alwwbvre.     But  the  subject  lias  Dot  yet  been  adec[untely  norknl  out. 

997.  Thia  dralniction  of  red  corpuscles  ncovMitatisi  the  birlh  of  new 
(nrjiuivlM,  to  kei'p  itp  the  uominl  mpply  of  bnnoglohin ;  imd.  indeul,  tlie 
ca«n>  in  which  after  even  grcnl  loss  i>l  blood  by  lieioorrhage  n  h4«lthy 
ruddiiMB*  return',  ami  that  often  raindly.ehoning  that  the  lost  corpiisclta 
bavr  htva  replaced,  as  well  as  the  cows  of  recovery  fVnin  the  disease  ana-min, 
tifnre  that  red  corpuscles  are,  even  in  adult   life,  bom  soinewhero  in  th« 

lo  the  deTClnpinf;  embryo  of  the  mammal  tlie  red  corpusclee  of  lite  blood 
af*  not  hKniof;|(ibin'huIdinK  non-uuclealeil  disra  of  stntma.  but  colored 
DucUaled  cells  which  have  artsea  in  the  followinj;  way. 

In  o-naio  re^oiM  of  the  etubrru  there  are  formed  neata  of  nuclei  imbedded 
in  that  kind  of  material  of  whii-h  we  have  already  (S  h)  spoken,  and  of 
wbMi  we  shall  have  B){»in  Ut  ii|N:ak,  aa  unililPeretiliated  protoplasm.  The 
Tf^f*"'  faalnrrv  »t'  ihi*  uiidilli-rvntiiUed  )irotu[>hu>m  are  due  to  the  maimer  iu 
which  iu  livio;:  biuin  1.^  -'>  .  in  i.-arryin;.'  iin  lUi  omlinui-d  building  up  and 
bmikinii  diiwn,  di-|iii«a*  of  itiw:lf.  iin  linid.  and  ilti  priMbn^ls.  These  arv  fur  a 
■  hil«i  to  arranged  M  to  lafm  a  cnlorlivs  iniu«  with  niinuln  colorltna  soli*) 
(lartjclra  or  c»l^csa  vacuole*  Initieddn]  in  ii,  tli<-  whole  having  a  granular 
appaftnUMv-  Afler  a  while  this  granular-lnokine  protoplaum  I*  in  laqt" 
OMMim  gnuliially  rvplaced  iiy  tnalcrial  of  dillvrcnt  optical  uml  chemical 
cbaract^w.  being,  fur  inrtnnce,  more  homoenMous  and  lcw"^nanutar"  in 
appearatKe :  this  new  material  i*  stroma,  and  as  it  is  formed,  there  it  funuod 
with  it,  and  in  SOUa  way  or  another  held  by  it,  a  ooloriiif'  matter,  bamio- 
KliAin.  We  cannot  at  piwent  say  aoylbinc  defioite  as  to  the  way  in  which 
and  |1m>  itefie  by  which  the  oriffinal  pnilopbfm  ii  thus  lo  a  large  ctlcnt 
diArantialM]  into  stroma  and  hmnoclobin.  All  we  know  is,  that  the  exist- 
of  what  we  have  calM  livinj;  •ttbstanoe  b  nectasory  to  the  formation 

atrena  and   hiemo|{lobin.     We,  therefore,  seem  juntiliiil   in  speaking  of 

Bvinjt  Mibstant-e  as  manufaotnrin;:  thoe  aubalanoM.  but  we  du  not  know 

ln«  living  sul»tanc«  tnras  itself,  so  to  apeak,  iiilu  stroma,  or  hoetno- 


60 


BLOOD. 


globin.or  both,  orwbotbkrbyHmcsKnCT,  tlii'  iinlnn!  of  which  i*  at  prcufciit^l 
unknown  to  iix.  it  cnovtrU  some  otihr  nuiti^rinl  wliicli  i«  prcwtit  in  the  | 

C>lo|ilium,  and  which  wc  may  rvgiint  lu  fwM\  for  itself,  into  oue  or  olhcr  or 
h  uf  tliCTc  b"idit'-«. 

When  this  ilitlorcniion  hiu  uk«n  pbuv,  or  while  it  »  stjll  gotnc  od,  Ute 
matcriHl  in  which  the  nucld  an  imbodded  diridc*  into  te]>itratv  cetl-bo<l!M 
for  ihe  eevernl  nuclei ;  and  thus  the  n«st  of  nuclei  is  traiigfornied  into  a 
group  of  niicIcal(Kl  red  corpUBL-les.  each  corpuscle  coDHieting  of  a  uucletw 
imbedded  in  a  ha<nia};lobin-holdiDf;  atroiun  to  which  is  »till  attached  man  or 
lesB  of  the  oriKinal  uodifltrenlialed  protoplasm.  ^ 

8tiU  later  on  in  the  life  of  the  «mhrvo  the  nucleated  ml  oorpuavles  *reH 
r^laced  hj-  nrduiary  red  corpuscles,  Uv  n  on -nucleated  diaca  coinpoaeil  aloioat 
exclutivelv  of  htcmoglobiuholdiDi;  slromn.  Ilovr  the  traotifuriiiution  tnkus 
place,  nud^  e^jieoiully  how  the  the  nucleus  corun  to  be  abwnt,  u  at  pnveiit  n 
matter  of  couniilerable  dispute;  Uien-  is  much,  however,  to  be  (aid  fur  tlie 
view  that  the  iiurmnl  red  ciirpiiscle  i»  n  portion  only  of  a  ell,  thut  it  in  n 
rrwment  of  cell  suhniance  which  hav  been  buddcil  oil'  and  sn  haii  Icll  tin; 
nuiileuii  behind.  ^ 

In  the-  ndult,  as  in  the  cmbri-o,  the  red  corpuKcles  appear  to  be  formed  oat  | 
of  nn7(H-diiig  colored  nuclenlea  crllt>. 

In  the  interior  of  bone*  is  n  pci-iilinr  ti«tiic  called  marrow,  which,  in  most 
pari*  being  very  full  of  blo(Hlvc*<<!|-«.  is  called  rnrf  umrrou-.  In  this  rwi 
marrow  the  capillaries  and  minute  veins  funn  an  inlncate  Inbyrinih  of  rolu- 
tirely  wide  paoages  with  very  thin  walls,  and  through  this  Inhyrinlh  tho 
How  of  blood  is  ci>mparatirely  slow.  In  the  passages  of  tliis  labyrioth  are 
found  colored  nucleated  cells,  thai  is  to  say,  cells  the  cell  substance  of  which 
has  undergone  mom  or  Ices  diSereniiation  into  hwmoglobin  and  stroma. 
And  there  sceiDs  to  be  going  on  in  red  marmw  a  multiplication  of  such 
oolorad  nucleated  cells,  some  of  which  tnu)i>foriiie<l,  in  sume  way  or  other. 
Into  red  uou-nucleat<><l  ilisua,  that  b,  into  ordinary  rc<l  curpusclea,  pan*  awny 
into  the  general  hhwul  ciirr«-nt.  In  other  wonln,  a  formation  of  red  i'»r(>t>s- 
cIM(  not  whoUv  unlike  thai  which  tiiknt  plaoc  in  the-  cmhryo,  is  in  thi^  iidull 
continually  going  on  in  the  red  niarmw  nf  (he  liuniv. 

According  to  flome  ulnorvem  tbi- ciilor^'d  nucleated  wlls  arise  by  division 
in  the  marrow  from  colurlc^s  cells,  not  unlike  hut  probably  diilincl  in  kind 
from  ordinary  while  corpuscles,  tlic  formation  of  biomoglobin  taking  pl«e« 
subsequont  to  cell-division.  Other  ohsorx-crs,  apparently  with  reamin,  urge 
that,  whatever  their  primal  origin,  these  c»1ore<t  nucleated  cells  arise  itiirinc 
post-em bryooic  life  by  the  division  of  previous  similar  colored  cells,  which 
thus  form  in  ihe  marrow  a  dislincl  class  of  cells  continually  undergoing 
division  and  thus  giving  rise  to  celU,  some  of  which  Iwonme  i«d  corpuscles 
and  pass  into  the  blood  stream,  while  others  remaiu  ia  the  marrow  to  undergo 
further  division  and  so  to  keep  up  Ihe  supply.  Such  repeatedly  dividing 
oells  may  6tlr  be  called  htematobltuU. 

A  «imilar  formation  of  red  corpuwlea  has  also  been  described,  though  with 
leas  c%'ideiic<>,  as  taking  place  in  the  spleen,  ngtecially  under  particular 
clrcumstancm,  surh  iu<  Hfler  i;i^ut  loss  of  blo(Hl. 

The  formation  of  red  eorpu»lw  i*,  therefore,  a  t)>ecial  procen.  taking 
place  in  !>|>ei-ial  regiims ;  wc  have  no  Mtlsflictory  evidence  that  tbc  ordinary 
white  eorpuseln  of  the  blood  are,  Ms  they  travel  in  tbo  current  of 
circulation,  tmii^formcd  into  red  corpuscle*. 

Tho  red  corpuscles  then,  to  sum  up,  are  iix-fiil  to  the  body  04i  acominl  of 
the  htemoglobin,  which  ronslilutes  to  nearly  the  whoU.>  of  their  solid  matter. 
What  funciiiins  the  Bironia  may  hnve  besidn  the  mere,  so  to  speak,  mechani- 
cal utie  of  holding  the  luemojjlobin  in  the  form  of  a  corpuscle  we  do  not 


I 


irith 

iilara 


TUB  COltPUSOLKS  OF  TUR    BLOOD. 


61 


K 


kawr.  Tbo  prinurjr  uw  of  the  bn-moglobio  is  to  curry  oxygen  rrom  tl>c 
UiBp  Id  the  toauM,  aod  il  would  appear  tliftl  it  ie  mivtmitiKeout  to  ibc  ocoif 
«aay  ihat  th«  hsMnoclobiii  ebouid  b«  ss  il  ir«re  boltled  iiji  in  corpii«dc8  rittWr 
ilaa  timpir  difflufid  tlirougb  (be  ploAtn*.  How  Umn  it  cor|Mi8ole  nii>y  livv 
tmnylnc  osyjreii  we  do  nol  exactly  know :  the  red  cor|iuscl«a  of  one  aniraiil, 
r.  y..  A  hir^l,  iiiJMtol  into  ibe  reoMk  of  nDotli«r,  e.  g..  a  mflininal.  disappear 
within  a  few  days;  but  this  aflbrds  no  roesaure  of  tn«  life  of  a  corpitMle  in 
hi  ova  bome.  Kveutually,  however,  the  red  corpuscle  dies,  iu  pinec  bting 
MpplUd  by  a  new  one.  Tlie  hieinoglobin  svt  fVe«  from  Uie  dead  i'nrj>uBdea 
a|Hiwii  to  have  a  Kcondary  use  in  forming  the  pigment  of  the  bile  and 
{Mfldblr  other  pigment*. 


The  n'hde  or  CtJarteu  Gnjnuttff. 


t  88.  Tbu  white  corpusol«s  arc  far  l«aB  numerous  than  the  red  ;  &  spect- 
mra  of  ordinary  healrhy  blood  will  contain  several  hundred  red  curpnsclea 
In  rmeh  white  curpuscle.  ihotifch  the  proporlioo.  even  in  health,  varies  coaud- 
«rably  onder  different  circuutslaoces.  rHiiKinjt  from  I  in  300  to  1  in  700. 
But  iboujrii  )<!»  numeruus,  the  while  i»r|tii<<.'lefl  are  {>robably  of  greater 
iaipavtaorr  to  the  blood  ilM^lf  thim  are  the  red  corpn^Ies;  the  latter  an 
(ftM^  Umiteil  to  liie  special  work  of  carrying  osypti  froni  the  ItiUKS  to  the 
while  ibe  ilirmer  prolmhly  enerl  a  oin^iili-roEle  inlluence  on  the  blood 
Uaelf,  and  help  tn  muiaDiiii  it  in  a  prti[ier  c<in<litiiin. 
Wb«D  Men  in  a  normid  condition,  and  "  at  r»t "  the  white  corpuscle  is  a 
«ll,  spberical,  colorluw  mow,  raryinK  in  siie,  hul  with  an  average  diameter 
of  abMI  10>.  and  prrwmio^  jtencraTly  a  lint-ly  but  ;«imetimea  ■  ooartelr 
^tmnular  appcanuici-.    [Fig.  9.J    The  surlincc.  even  when  tbo  corpoiolc  ti 

fWta.9. 

O 


I 


^4 
«.  wbUtcnnmirtnor  kiinwnMond;  il.  red  roryiBolio  (hl(h  |n««r}.) 


pHftctly  at  rR<t,  t»  not  absolutely  smooth  and  cvrn,  but  lomewhat  irregular, 
thvaby  coniribuiing  to  the  granular  appcsmmr:  and  at  times  thr»c  irrcgu- 
lariUaaa  ar«  exacgcnitixl  into  protulwrenccs  nr  "pwiulo|KHlia"  of  varring 
rise  »t  form,  iKe  corpuscle  in  this  way  asmmin^  various  forms  without 
^•Ogiug  its  bulk,  and  br  the  nssumption  of  a  senos  of  fomu  «hining  its 
pWc  Of  iheae  "  amwbold  moveinenis,"  as  they  are  called,  we  iball  have 
ta  spekk  later  on. 

In  oarryiug  on  theoe  Brmeboid  morctaents  the  mrpttscle  may  transform 
ilsalf  AtKO  a  spherical  mass  into  a  thin.  Hat.  irregular  plate  :  and  when  this 
cecan  there  mnr  be  seen  at  tintes  in  the  midst  of  the  extended  finely  granu- 
lar RiMa  r>r  rW/ Oddy,  a  smaller  bwly  of  different  aspect  and  refhictive  (Mwer, 
the  Nwe/nuL  Tlie  normal  prcaencie  of  a  nucle<i!t  in  the  white  corpuscle  mar 
■lao  be  shown  by  ircntiug  the  ciirpusele  with  dilute  accctc  acid,  which  swells 
op  aad  renders  more  transparent  the  cell  body  but  makes  the  imdotu  more 


63 


BLOOD. 


refniclivi.'  an<l  mora  Kliarpl;r  drliiiiH).  imd  »>  iuok  iitiupii-uouK,  nr  by  llie  ti*» 
uf  Hininiiig  KMgenU,  the  niinririly  i>t'  nhicb  iiiain  ihc  tuioltii*  niort-  ri-mlilr 
ttud  luuri-  deeply  lliiiu  ihr  nrU  IkhIv.  In  whnt  jxrhapw  may  lie  CQtii>i«l<^ri->l  a. 
tvpivul  while  curjiiiK'Iv,  Ihn  iiuclvu*  w  a  i>pboricii]  ninw  about  2-3  f  in 
diameter,  (Hit  it  variiii  in  aite  in  diflervnt  ixirpiMicU^.  and  not  iin(W-i(\ieatly  i» 
irregular  in  fomi,  at  leiW  after  lh*t  nction  of  rciigt-nt*.  It  oci-iwionnlly 
■I>pcan>  ai  if  obuut  to  diride  into  fmginrnto,  imd  soDiclimcg  a  (7nr|>u»de  may 
cunliiiii  two  or  rrvn  more  (then  gi-ncmllv  >niull)  nuclei.  Though  tlainiog 
rMdily  with  Rlaining  niigcnlv.  the  nuclcui  of  nii  onlinar^'  irbit«  cormisclc 
iloi-B  not  divw  the  nuclear  network  which  u  w  cluniclcrialic,  m  ne  »hall  mv, 
of  tbo  Duclej  of  many  eelis,  and  iihieh  in  tbew  i«  ih^.-  ]>arl  of  the  uuc]«us 
which  especially  stains;  in  the  clwely  allic<I  lymph  corpuftclc*,  to  which  vre 
shall  have  inimcdiaiely  to  refer,  a  nuelcAr  network  is  {ireacnt. 

The  cell  bo<ly  of  the  white  ciir|ni«cle  may  be  taken  as  a  good  example  of 
what  we  have  called  undi  Re  re  minted  protoplMm.  Optically,  it  con^ista  of  a 
unifonnly  transparent  but  Eomewhat  refractive  material  or  basis,  in  which 
are  imb^ded  minute  particlee.  generally  spherical  in  form,  and  in  which 
aumetimes  occur  minute  vacuoles  filled  with  fluid :  it  is  rarely,  if  ever,  that 
any  distinct  network,  like  that  which  is  itomelimes  obwrved  in  other  cetla, 
can  be  seen  in  the  cell  body  of  a  while  curnnsele  whether  Gtainedor  no.  The 
Imbedded  particlee  are  generally  very  email,  and  f>>r  the  must  part  distributed 
uniformly  over  the  cell  body,  ^viu)>  it  the  finely  granular  atipecl  spokea  of 
above;  Mtmeliuiee.  however,  the  particles  are  relatively  large,  makin);  the 
oorpuaclea  coarsely  ^^raunlnr.  the  ooanejmnuleii  \mi\^  l're>(iitntly  CMifiiied 
to  one  or  another  {Htri  uf  the  cell  body.  Titcse  partiileF  or  granule:},  whether 
coarw  or  fine,  var>'  iu  nature ;  some  of  tlieui.  as  shown  by  iheir  greater 
refractive  power,  ihetr  >iaiuiDg  with  osmic  acid,  and  Ibeir  wilutiwi  by  miIv 
«Dl(  of  fat,  are  fattr  in  nature;  others  luar  similarly  be  vhowii  by  thcirS 
reaction*  tn  he  pmteld  in  nature.  ™ 

The  material  in  which  thcw  granuln  arc  inibetlded,  and  which  fbrntf  iho 
greater  jiarlof  the  <-ell  bualy.  ha»  notpeeini  optical  features;  xofar  aacan  b« 
ascertnimd,  it  apix-am  under  the  micrM>ro|>e  \u  be  ho<nog«-nc<His ;  no  definite 
structure  can  be  detected  in  it.  It  muKt  be  bnmr  in  mind  that  the  whole 
corpuscle  connsis  largely  •  f  water,  the  total  mlid  matter  amounting  to  not 
much  more  than  l<i  per  ctaL  Tli«  transparent  material  of  the  cell  body 
must,  therefore,  be  in  a  condition  which  we  may  call  fwmilluid,  or  semisoliit. 
wilbout  beinc  called  upon  to  defiao  what  we  eiactly  mean  by  these  lemtt. 
Tbis  approach  to  fluidity  appearv  to  be  oxinertcd  with  the  gml  mobility  nl* 
the  c«ll  bmly.  as  shown  in  ils  anxrhoid  movements. 

$  26.  Wlttn  we  submit  to  chemical  examtnalion  a  sutKcieni  mass  uf  white 
corpUKlee.  «paraied  out  from  the  bl<<wl  by  special  means  and  obtained  toler- 
ably free  ftvaa  nd  coqiuackB  and  plasma  tor  apply  to  the  while  blood-cur- 
piudM  tbe  chemical  r«sulls  obtaiDM  ftvra  the  more  easily  procure*!  Iym]>h- 
corposelea,  which,  aa  we  shall  aee,  are  very  similar  to,  and,  indetd.  in  many 
wajra  niated  to  the  white  eorpiuelea  of  tbe  btood  i.  we  fin>l  Ihul  this  amaJl 
mImI  matter  of  tbe  corpuscle  coomMs  largely  of  certain  pnxeidt. 

One  uf  theee  |)rDtd<U  is  a  body  dtber  ideniioal  with,  or  closely  allied  (n, 
the  pruieid  called  mjnMN.  wbicb  we  shall  have  lu  etudy  more  fully  in  oon* 
i»ertiua  wtih  muscular  tiMut  At  present  we  may  umplr  aay  thai  mrcttn  !« 
a  body  intermediate  between  fibrin  and  globulin,  bein^  Icwt  iviuble  iluin  the 
latter  and  more  soluble  iban  the  former ;  thus  while  it  tr  hardly  at  all  wiluhlv 
is  a  1  per  cent,  wlution  uf  sodium  chloride  or  other  neutral  Nilt.  it  is,  unlike 
fibrin,  spctdily  ami  wbuUv  dimolred  br  a  tO  {wr  nal.  mlutivD.  My(«in  is 
fbrtJMf  iniervtiae  beoitiM,  as  we  shall  sew,  ju>t  a>  fibrin  is  formed  in  the 
douieg  of  bluod  tnu  fibrinngan,  so  mjixin  it  formed  uut  of  a  prvenliDi; 


TBS  CORPUSCLKS  OF  TDK    BLOOD. 


I 


mjMiiio|[«ii,  iltirinK  m  kuul  of  cIoIUuk  wbidi  lakes  plnco  Lu  iiiu»cular  fibro 
wd  vkirh  U  itiukeii  of  a»  rigor  inorlia.  Aud  w«  bavv  rmituii*  fur  ilihikioK 
tKst  in  tW  living  white  biMiil-coriiuMic  Iberc  dott  exM  a  body  idtnitciU 
Willi  or  kJli^'d  tn  iiijrudiDiigeD,  wbicn  nc  mtty  *pc»k  of  uh  Iwing  in  li  fluid  ena- 
ditioB :  and  whicb  nti  thr  dcatb  of  lliv  ttir|>*'*c'*=  'i  cnnvi-rlrcl,  by  ■  kind  of 
eloUlafc  iaio  myoain,  or  into  nii  nlliail  hmly,  wbii-h  boiug  wlici,  give*  tbs 
bodj  «  the  corpiucle  a  »lifliii-w  mul  rigidity  wbtrh  it  did  not  ponoM  during 

BmUm  thh  mrmia  or  Riyoein-liko  protrid,  tbc  white  corpunclce  nUo  con- 
tmia  nlhtr  parngl'ditilin  iiwif  or  some  ofh^^r  member  of  ibe  globulin  group, 
■*  well  u  n  tKMly  or  b'xliv*  like  or  tdentictd  nith  Mruin-nlbuniin. 

lo  Midiliun,  tbt-rr  is  prciwiit,  in  somoirhat  c»nsideniblc  quiuititr,  h  Biib- 
fltaiK*  of  m  [peculiar  naturv,  which,  sinoe  it  it  confined  lo  the  niiefe!  at  lite 
CM|»iwelw.  Mid  further  ^eems  lo  be  prewint  in  all  Duclei.  Iihh  been  called 
mmtUim.  Thit  uuclein.  Khicb  lhou);h  a  eoiDp]«X  Dttrogenmia  body  h  very 
diflhnal  in  rompoeitiou  and  nnlure  Irom  proteids,  i>  renitirknble  un  the  on« 
bani  for  being  a  very  stable  iuert  body,  and  on  the  other  for  eonlaining  a 
brg*  qoaniily  (aceording  lo  BQue  obeervers  nearly  10  per  cent.)  of  phos- 
pboma.  which  app«an  to  enter  more  cIokIj  into  ibe  ctmclureof  tbo  nM>l«cule 
Una  it  does  in  ta«  caee  of  prulei'Is. 

K«xt  ID  importance  lo  ine  proldd»,  os  constant  constituents  of  the  whitfl 
corpoacloi.  c.x>Rie  oerrain  fala.  Among  theae  the  nioflt  couBpieuous  is  the  com- 
plex falty  body  kcHAw. 

Id  tbe  uueof  niany  corpuscles  at  all  eveiiU  wc  have  evidence  of  tbe  pres- 
^KC  of  a  nieniber  of  the  large  rrmip  of  car)>uhydraie».  comurising  slarcliei 
■ad  njpir,  viz.,  the  tturuh-likc  body  gli/aigeM,  which  ne  shall  have  In  study 
man  fully  hemner.  This  glycogen  may  ext^t  in  the  living  corpuscle  a* 
gljrtngvn,  hut  it  m  very  apt,  aAor  Uto  dcatli  of  ihe  corpuitclc,  to  become 
cfc— grd  bj  h)  dnuiou  into  roma  torn  of  sugar,  nicli  as  nialtoM  or  dextrnee. 

I  itli  the  tub  of  the  white  corpuacles  is  chiiracteriu<l  by  coataioing  a 
frlativvly  large  quantity  of  |>otnseiuni  and  of  phosphates  and  by  biHng  reln- 
tiralT  pinr  in  chWidea  and  in  sodium.  But  in  this  respect  thu  corpuscle  is 
mmij  an  example  of  what  weuiH  to  be  a  general  role  (to  which,  however. 
llMnrw  tnay  be  exoeplMMia)  that  while  tbe  elements  of  the  tissues  themwlvcs 
are  rich  in  potassium  and  ph(*)phat«fl,  the  blood  plnsma  or  lymph  on  which 
ibey  live  abounds  in  chlorides  and  sodium  salts. 

i  30.  Id  the  broad  features  abuvc  lueniioned,  the  white  blood -corpuscle 
may  be  lakeu  as  »  picture  and  example  of  all  living  tissues.  If  we  examine 
llta  bisbilogica]  elemenls  of  any  tissue,  whether  wv  take  an  epithelium  cell, 
or  a  nerve  cell,  or  a  cartilage  cell,  or  a  muwrular  libre,  we  meet  with  very 
■ittiibtr  feaiurea  Studying  tbe  element  morpbologteally,  we  find  a  nucleus' 
and  a  irll  lioily,  llw  nuHcui  having  the  general  cbaraclera  described  above 
with  fmjuetilly  other  charactvrw  iiitniduood,  and  the  cell  body  cunsiHting  of 
■t  IcMI  more  than  one  kiml  nf  niiiteriiil,  the  mulerialH  being  aoroeiimea  ao 
dinieard  ■>  to  produce  the  npiiciil  i-tTtTi  nimply  i>f  ii  trauHparent  moss  in 
■rbidi  granule*  are  iriil><^lili.-d,  in  which  caM-  wi-  niieak  of  liie  cell  UkIv  us 
pretop&niic.  but  at  «[hi-r  limiv  f  iirrnngnl  that  tlie  oil  Wly  |iodfiesaes  dif- 
wmllated  structure.  Studyiuf;  the  clement  fmm  a  chemical  iwint  of  view. 
W»  tad  protcid*  alwny*  prcMnt.  and  nnioog  lh««e  bodies  idenlicAl  with  or 
atm  or  tess  closelv  iilliiil  to  niy<«in,  we  generally  have  eridence  of  Uw  prce- 
«Dre  alsn  of  fat  of'winie  kind  anil  of  fiioe  memltnr  or  members  of  tbe  earbo- 
liydrate  gn'uji.  niwl  the  wh  always  cunlains  potaiwium  nitd  |ili<M|>)mtfii,  with 
•Blpbatae.  chloridu,  sodium,  and  cnlcium,  to  which  may  If  adtled  magnesium 
au  iron. 

■  Ttw mlmnw  rf  ■ultfniiclnu ttrusmwi do» wnl  tWnA  tlw |i»i wit wyiim»nt. 


64 


BLOOD. 


We  sialwliu  the  lutroduction  Iliat  liring  matter  is  alwsya  un{ieT;gtNii 
clieniiciil  cbaDjte;  (liia  continued  chemical  dianiice  itc  tntty  ileiiote  by  the 
tonn  nietabolirm.  'iVo  fiirtlier  urged  tluit  as  looe  »  lirins  muter  ii  aliv«, 
llti^  (-beiukal  clituit(e  or  luelabulttin  u  of  ft  double  kiud.  On  tlie  one  band, 
till-  liviii);  NubntniR'f  Jit  CMiliiiually  breaking  ilimn  iiiti^  rimplcr  bodi««,  with 
a  nutting  froc  of  t.-uergr ;  this  jmrl  uf  tht-  miTiiihoU^m  w4t  may  apeak  of  lu 
roftde  up  of  katabolio  chaTigi-N.  On  the  other  baiiil,  the  living  •iib^taDoa  ia 
OontinuBlly  building  ilvcilf  np.  I'mhiHlving  ciivrgv  into  iim-ll'  and  ho  rcplcB' 
Hhing  it*  Htorv  of  riicrgy  ;  thi»  part  nt''  the  metabolism  wo  may  rpcak  of  at 
iDiide  up  of  nnaltolln  chang<3>.  Wo  alw)  urged  that  in  every  picpp  of  living 
tiaiUfl  there  might  In'  <  1 )  tha  actual  living  Kubtslance  itaclf,  (2)  matoniil  which 
is  nn«cnt  for  the  puriiose  of  becoming,  and  is  on  the  way  to  boeome  living 
Butistancfl — that  is  to  snv,  food  unilergoing  or  about  to  undergo  anabolw 
vhang««,  and  (A)  nintcrial  irhich  ha»  rcaullod  from,  or  is  reeuliing  from,  tba 
breaking  down  of  the  living  substance — that  is  to  say,  material  which  l;aa 
uudergone  or  is  undergoing  kalaholic  change;,  and  which  ne  speak  of  as 
waste.  Id  using  the  wor<I  "living  subetance,"  however,  we  must  remember 
tliat  iu  reality  it  ia  not  a  Bubslance  in  the  chemical  sense  of  the  irord,  but 
material  undergiiing  a  series  of  changes. 

If,  now,  we  lutk  the  <)ueeuoD,  which  pan  of  the  body  of  the  white  corpuscle 
<or  of  a  fimihir  element  of  auother  tiai^ue)  U  the  real  living  suh^tance.  and 
wbieh  jitirt  U  ftiod  or  waste,  we  ask  the  question  which  we  cannot  lU  vetdefi- 
ni[«lv  anawer.  We  have  at  preM^ot  no  adeijitnte  mornholozlcal  criteria  to 
enable  ua  to  judge,  by  optical  characters,  what  iji  really  living  mid  what  b 
not. 

On«  thlDg  we  may  )ierbajie  stay ;  the  nmterinl  which  appears  in  Uie  cell 
body  tn  tbe  form  of  distinct  giiuiu leu,  merely  liHlgei)  in  the  tnorv  tnuisparcnt 
ntatcriitl,  eunuot  be  part  of  the  txmiI  tivttig  substance;  it  must  lie  cither  food 
or  waste.  Many  of  these  graiiulei'  arc  fat,  nnd  we  have  at  times  an  opportunity 
of  observing  that  thcr  have  been  introduced  into  the  corpuscle  from  the  sur- 
rounding plasma.  The  white  cor|)UBclc,  as  we  have  said,  has  the  jM>wer  ef 
executing  amcelmid  movements ;  it  can  creep  around  objecia,  envelope  them 
with  its  own  substance,  and  so  pot  them  inside  it^lf.  The  granulea  of  fat 
thus  introduced  may  be  suluequently  extruded  or  may  disftp]»tiar  within  the 
<XHpu8cIe:  in  the  latter  case  they  are  obviously  cliaiiged.  and  ap|>arently 
made  use  of  by  the  corpuscle.  In  other  wunU,  thW  faity  ^rauulei  are  appa- 
rently food  material,  on  their  way  to  he  worked  up  in  the  living  substance 
of  the  corpuscle. 

But  we  have  also  evidence  that  dimilnr  granuleti  of  fat  rwv  make  their 
appearance  wholly  wilhiu  the  oorpuacle;  they  are  priHiocta  of  the  activity  of 
the  ooqmsele.  We  have  further  reason  to  ihiak  that  in  some  i-a-*eT<.  at  all 
events,  they  arise  from  lliu  breaking  down  of  the  living  Huhntancti  of  the  eor- 
puBcle,  that  ihey  are  what  we  have  calliH]  v/wtU:  prntluct*.  ^t 

Rut  all  the  granulcK  vJnihle  in  u  cnrriiiHcIe  are  n»t  neci^warily  fatty  i^l 
nnturo ;  aomo  of  them  may  undouhleilly  he  pniti^id  gritnules,  und  it  i*  )>os>i- 
blo  that  some  of  tliem  may  at  timoi  he  of  carbohydrate  or  other  nature, 
all  eases,  however,  they  are  either  fond  material  or  waste  products.     An 
what  i*  true  of  the  easily  distingui«hed  granules  is  also  true  of  other  sul 
•caiicat,  in  solution  or  in  a  nilid  form,  but  so  disjiosed  as  not  to  be  optically 
teowniied. 

Hcoce  a  part,  and  it  may  bo  no  inconsidemhie  part,  of  the  white  corpus- 
vie  may  be  nut  living  Guhstniico  at  all.  but  either  food  or  waste.  Furtl>er  it 
does  not  oeoeesarilr  follow  that  the  whole  of  any  quantity  of  material,  fatty 
or  othernbe,  introduced  into  the  corpuscle  from  without,  should  actually 
l>e  built  up  into  and  ■o  become  part  »f  the  living  subatance;  the  chau^ 


u9 


Tirx  c.'OBPi'act.Es  of  tiik  blood. 


65 


\ 


■at  raw  fnod  to  livhig  (ubclance  are,  u  we  bare  already  mii),  prolmiMy 

.  u)<l  it  inaT  Iw  ibat  after  a  ceHain  number  of  cluingeit,  frw  or  mnny. 

•nljr  of  tbe  material  it  accepted  aa  wcjrthy  uf  iKing  niu*!!;  alivv,  anil 

ml.  beiDf;  rejected,  beconia  at  ODr«  iradie  matter  ;  or  the  malarial  may, 

a  aftrr  it  lia*  under^oue  this  or  ifaat  rhon^,  nervr  acltially  enter  into 

tbr  liriojt  aubMutoe  but  all  become  wai^i'  inaitcr.     Wo  miv  wa*tc  matter, 

but  tliia  (Ion  not  mean  umIcm  auller.     Tho  mallrr  m  formnl   may  nilbotit 

niarinit  iutu  the  living  mib>4aD0i!  be  of  lonie  ^uWidiarr  use  to  tbc  corpiiecle, 

«r  M  (NTobohly  morv  otltn  bappomt,  bcios  diwhaiwu  from  tho  cnrpuwle, 

Ba^  lip  of  UM-  to  Kime  other  part  of  the  mdy.     AN  e  do  not  know  how  the 

Uthiie  •uh*taDi<e  bailds  ilMlf  up,  but  wo  aoem  <>ompcll«l  to  admit  that,  in 

(•ttaia  csfn  at  all  cvi-nls,  it  is  abk>  in  some  way  or  other  to  produce 

rkiK)^  iin  maleriid  while  that  matrrlid  is  Mill  oiiUide  the  liviiif;  eulwiance 

M  it  were,  before  it  enters  into  nnd  indeed  without  ile  ever  actually  entering 

inlallu!  cotnpofilion  of  the  livio^  fiub«tiiHce.     On  the  other  hand,  we  muol 

nptiOy  admit  that  tome  of  the  wnnte  friibetances  are  the  direct  pruducia  of 

kaiabolic  changes  of  the  livingt  subelance  il«elf— were  aL'tuallv  oure  |>iirt 

'if  lirtn^  mbetance.     Hence  nc  uu^bt,  |M>rbap«,  to  distiaguiJi  the  nruil- 

nf  the  aciiriiy  of  living  matter  into  waste  pruducta  proper,  the  <lirecl 

of  talaUilic  <-hhn]:ni.  and  into  hyc  produda  which  nre  the  rcHullii  of 

dfircCed  bv  the  living  nmtli-r  oui^tdi' it^ll'and  nbidi  cannot,  tbore- 

eODiiilercQ  an  Dcvrivarily  i-itlivr  iiimlHilic  nr  katatiulic. 

ine  llttebemical  chanclcni  of  Iht'  living  matter  itielf  wo  cAimot 

_.    make  anv  very  dvlinit<>  »talemcnu     V,\:  may  av  lliat  the  pmteid 

>.  or  rather  t^r  protcid  nntrcnient  i>r  unli^colent*  of  my  win,  enter  in 

■ay  into  iia  stniclure,  but  we  nre  not  jiiMiticd  in  Ntying  thai  the  living 

labiluce  cMiaisIs  unly  of  prnlcid  matter  in  n  peculiar  condition.     And,  in- 

tifcr-'  '•'■  -'-oiitency  with  which  aoiae  reprewntalive  of  fatty  bodies, and 
w-  iintive  of  carhuhyilnites  always  appear  in  living  tueue  would, 

pnitij-.  niiinrlrnd  u«  to  m|i[Hi»e  that  these  equally  wiili  proteid  material 
*r»  tanniinl  til  itM  Htructure.  Again,  though  the  behavior  of  the  nuck-ue 
m  oiDlraati-d  witli  that  of  the  ceW  budy,  lea<U  u*  to  Mippote  tlmt  the  living 
nhMaara  of  ibo  former  in  a  itifrmnl  kind  from  that  of  the  latter,  we  do 
BM  '  "'tly  in  what  iIk^  diU'iTt-nco  coiim*!*.     Thti  niiclFiii,  w  we  have 

•K.  nvctfiii  whiih.  peiha|t»,  «c  mav  regard  w  a  largely  modified 

pnu-t .  l-iii  htfiuff  a  body  which  it>  reinarkablf  (or  il»  ftability,  lor  the  diffi- 

I  fall)  oith  whii'h  it  la  changed  by  ehemicnl  rcngcnt».  cannot  be  regard«il  as 
■I  mnal  ftut  of  the  ecHenlially  mobile  living  »ibslnnce  of  the  nucIeuB. 
Ik  !&■  nmneetion  it  may  be  morth  while  to  again  call  attention  to  ibe 
kl  tW  the  «or]:u«-U-  contains  b  very  large  quantity  of  water,  vix.  alxHit 
MftrcraL  ftiii  of  tbi«,  we  do  not  know  how  much,  probably  exists  in  a 
■Mcorin*  definite  combinaliou  with  tho  protoplasm,  siimewbal  after  the 
■MBcr  nf,  lu  u«o  what  i«  a  mere  illustration,  the  trater  of  crTstallizaiion  of 
Mkib  If  we  imagine  a  whole  gmu^  of  dillbnnt  complex  salts  continually 
<gwfinl  in  (uni  in  being  cry«lalli»d  aitd  being  decryMalliied.  the  water 
lkM«Bf*getl  by  the  *allf  will  give  UM  a  rough  image  of  the  water  which 
MM!  a  and  uul  of  the  sobftance  of  the  cor|iu>clc  an  the  reault  of  its  meta- 
MBcactiriiy.  We  might  cull  this  "  water  of  metaboliiini."  Another  part 
<^  Ifca  water,  carrying  iu  this  esw  suliftnni-eii  in  solution,  iimlwbly  exisia  in 
ifarmoT  (Dlerriicee  too  small  to  be  seen  nith  even  llic  hiKbcxt  powers  of  (he 
aitnacnpr.  Btill  another  part  of  the  water  similarly  hutdiag  subMaoccs  In 
mtaiiim  cxbl«  at  linKs  in  dt-iiuiie  spaces  visible  under  the  mtcroaoopo,  Dton 
•rim  rvf^nlarly  spherii-ul.  and  called  vacuole*. 
■  WakBTed«rlt  thus  at  leugth  uu  the  nhite  cirpUK-h)  >d  the  fir«t  plaoo 
Baesna  as  we  Imvo  already  eaid  what  takes  place  in  U  is  in  A  atnao  *  picturo 


I 


6S 


of  wliut  takes  ;i1ni-e  in  *\]  lirin;;  elrucliim,  nn>i  iit  ihc  et-oiKl  ploop 
ll)L'  fiic-U  whioli  wre  linrc  mefilioDod  help  uh  (o  uiiilcmKifl  how  the 
ciirpiiM'U-  may  carrv  on  in  ilic  blond  a  n-ork  of  no  im|u>riunt  kiuii ;  for  from 
wliat  linn  iieeii  aitid  it  in  obviotin  itinl  the  white  curjKi^cIo  is  OJUlinunllv  itrt- 
ing  u(ioi)  mkI  Iwiti^'  iiaed  upon  by  ibe  plasma. 

$31.  To  II II  lie  ret  and.  however,  the  vriirk  of  these  while  ror|>uH)ea, 
inii»t  Ii^tni  nbot  U  known  of  their  historv. 

In  »iiPci.-Mivc  droiM  iif  bloml  taken  at  (iiflerent  times  fW>in  tlie  same  ini 
vidunl.  llic  number  of  colorlew  coqiusde.i  will  be  foiiii<l  to  vary  ^t-ry  luuc 
not  only  nOtlivdy  to  th<!  red  coqiuvoles,  l>ut  bIsu  ab«i.>lut«]y.     Th«y  iiiu 
tbereforo.  "  come  and  gti." 

In  treating  of  ttit;  lyinpliiitic  *yiit«m  vc  fhall  hnvc  to  point  out  tlini  a 
very  largu  iiimiility  of  tliiiii  enllud  Ivnijili,  ci^tiliiinint;  a  vnry  (,i>n«idrnible 
number  of  bodi(»i,  very  similar  in  thvir  gmrral  chiimctcrg  lo  the  white  cor 
]>ufic]eB  uf  the  Mood,  is  being  riinlinimlly  poured  Into  llio  vaxeiilar  erntcm  «( 
Ibe  point  where  llie  ihoratic  durl  ioinn  lliu  grc«t  veiu«  on  the  left  ai\v  of  the 
ueok,  and  tv  a  k^ra  exlrnl  whcir  llic  olhcr  tnrge  lymiihaties  join  the  venoos 
■VHleiu  on  tho  right  eiiie  ol'  th<-  nock.  Thetw  corpuscle*  of  lymph,  which,  as 
we  have  just  said.  ek«ely  rc«cnib)Ct  and,  indeed,  are  with  difficulty  distin- 
guisbeil  I'niiD  the  while  corpu^cloa  of  the  blood,  but  of  which,  when  they 
exist  outside  the  vaHcultir  eysleni,  it  will  be  convenient  to  speak  of  a^  Intro- 
eyttM,  are  found  along  the  whole  length  of  the  lymphatie  aystem,  but  are 
Diore  numerous  in  the  Ivmphfttic  veesela  aller  theae  have  paaaed  tlirougfa 
the  lymphatic  glands.  'Theae  lymphatic  glands  are  partly  eompoHed  uf 
whal  '»  kuown  as  adenoid  tissue, a  special  kind  of  connective  tatue  arranged 
an  a  dc-licaie  network.  The  inemheH  of  this  are  crowded  with  oolorlesa  nu> 
clr-atcil  cells,  which,  though  varying  iu  slxe.  are  fur  (he  most  part  •mall,  the 
nucleui)  lieing  surrounded  by  a  relatively  small  quantity  of  cell  iiilwUtiicv. 
Many  of  thv-w;  cells  show  signs  that  ihcy  are  undergoing  cell -4)1  vision,  and 
vre  have  rcuMnn  to  think  thai  ivlls  so  formed.  a<-(jiiir{ng  a  liirger  Hinoiint  of 
cell  substance,  become  veritable  Iciicjcytw.  In  other  wur«ls,  lencocyt** 
multiply  ill  tlic  lymphHtic  glandi!,  and  leaving  the  glands  by  the  lymphatic 
vessels,  make  their  way  lo  the  Mood.  I'att'hes  and  tracts  of  similar  adenol^ 
liasue.  not  nrmnged,  however,  us  distinct  glands,  but  similarly  oi'cupie^l  b^ 
developing  leucocyte*  and  similarly  connected  with  lymfilialtc  veawls,  are 
(bund  in  various  parts  of  the  body,  especially  in  the  nmeous  inombraaes. 
Hence.  W'e  may  conclude  that  from  varioua  parts  of  the  bmlv,  the  lyni- 
pbatios  are  continually  bringing  to  the  bhiiid  an  abundant  supply  of  leiico- 
cyi^a,  and  that  these  in  tbe  blood  become  urdinarv  white  4-orpUi>c1t«.  This 
is  probably  the  chief  source  of  the  white  corpuscles,  for  though  tht*  nhite 
our|>uscles  have  been  seen  dividing  in  the  bhxHl  Itself,  no  large  increase  takes 
place  in  that  way. 

£32.  It  follows  that  since  white  corpuscle:-  nrr  thus  continually  bciDe 
sduod  to  the  MoihI,  white  corpuscltni  must  as  continttiilly  either  be  ilcstroycu, 
or  be  transfonncd,  or  mcsjh^  mini  the  interior  of  the  blood vewels:  otherwise 
ihe  bloorl  Would  soon  be  Mocked  with  white  corpusi'Uw. 

Some  dn  leave  the  bhimlvi^Mcl*.  In  Ircntiiii;  of  the  circulation  wc  sball 
have  to  ]K(int  nut  that  while  eortiuscles  an-  abb'  to  pierce  the  wall*  of  the 
capillariiv  and  minute  veins,  nno  thus  to  mnkc  their  way  from  the  interior 
of  tbe  bluudvnw'U  into  K{iaces  filled  witli  lymph,  tbe  "lymph  spaces,"  as 
tbey  an  called,  of  the  tiwiue  lying  outside  the  bloodvessels.  This  is  spoken 
of  as  the  "migration  of  the  while  corpuscleH."  In  an  "ia6aiueil  area" 
large  nuiul>cr«  of  white  corpuscles  are  thus  drained  away  Uom  the  blood 
into  tie  lymph  spaces  of  the  tbsue;  and  it  is  probable  that  a  similar  Icaa 
takes  pUoe,  awire  or  less,  under  norma]  couditious.    lliese  migratiug 


se  migrauug  oc^ 


TUB  CORPUSrLBS  OP  THE    BLOUU. 


67 


I 


f  roDawiDK  ibe  d^-vioiii  tract*  of  tlic  lympli,  find  their  wny 
bluod:  toiDC  or  I  hem,  huwovcr,  may  reniuiii,  and  uridi.-ri^i 
vafioo*  ebanra.  Thus,  in  intlamcd  iireni).  when  »u|iMinili<)ii  rullowii  in- 
flaaattlioa.  t£«  whil«  <»r|iiiM>1c!t  which  have  niixrsied  may  Wi^itm'  "ihi» 
OMpOKlet,"  or.  where  thickoniiii;  nud  Kr<"*'l>  follow  ii|h>u  ii)flnmmnli»ii, 
OMT,  BflnQrilini;  to  uiiiBV  iiulhoritleE,  h6is>iii«  tmmrormed  intn  (em|iiirnrv  ur 
pvnnaiKnt  tuMiu.  ni|x'rin]ly  cimncctivt-  tlwue  ;  but  this  trantfitrmiitioii  mio 
dtm  b  dlifiuicd.  Wh^ii  nn  ititlBmnialiiiii  sulMtdett  withoni  U<nvirig  any 
dbct  ■  few  CT»q>uwl«i  only  wilt  Iw  found  iu  iho  tinuo ;  IhuM  which  had 
prwiottily  mignU'd  Diu*t,  ilicrefuro,  have  lii:rn  dii>[iijw>il  uf  in  fonie  war  or 

MMtiMr. 

In  iMBkbg  of  the  forniniioD  nf  rod  corptucU-s  ($27)  we  mw  that  not 
oaljr  it  la  not  pruvcti  thai  tli<*  iiui-lcatcd  oarpturclcs  wliich  give  rJM  to  red 
VorfNncka  are  ordinary  nhitv  cornii»cle«,  bnt  that  in  all  probabililv  Ihe  real 
banwtobluiv.  the  pnrcnu  of  rwi  corpuwJcs,  arc  spvcisl  corpuscW  devel- 
•|icd  in  Hue  »ituation]^  irhcro  Iho  niiimifiiclura  uf  rcl  corfiuscles  takea  place. 
iio  6u,  tbcrtri'ore.  from  an»uminK,  at  is  eomelirncfl  done,  that  ihe  white  car- 

ricl«a  of  llie  blood  ut«  all  of  tnein  on  their  way  to  become  red  corpiisclea, 
may  Iw  duubtei)  whetlier  any  of  ihem  are.  In  any  cii*e,  hnwever,  «rei) 
■•ktnt;  atlowaa<«  for  thotw  which  mit^rate,  a  very  coitiderable  uumhcrof 
tb«  whiu  oorpuaeUa  matt  "disappear"  in  some  nay  or  oilier  frum  ih<'  blood 
Unam,  Will  in  may,  pcrhap*,  siieak  of  tiieir  di«tpj>eiinin<'e  an  being  n 
•*  dwintction "  or  "  dlwolution."  We  have,  us  ret,  no  exact  kuo<rlei]gn  to 
■•iiiiti-  ti*  in  tliv  tuaitter,  but  ne  cait  readily  imauiiie,  tliiit  uuun  the  death  of 
'j'liaclei,  ibc  •ulwtaneea  >'iinip(Ming  it,  after  unilergomj^  chaiigra,  are 
.._...  i^l  by  and  become  part  uf  the  planmiL  If  dc^,  the  ct>rpiiiicU's  a«  they 
di*  noat  t«i>eale<tly  influcooe  tlw  coni|Mk<jii<iii  and  nature  of  the  plnsma. 

But  if  (hey  thus  aliect  the  plainia  in  ihcir  death,  it  is  even  more  proba- 
ble that  ihev  influence  it  during  ihoir  life  Beinj;;  alive  they  must  he  cou- 
tiimally  laliiuf:  in  and  giving  out.  Ah  we  have  already  said  they  arc 
knonn  to  iu;;e9l.  after  the  fiLthioii  of  an  amaba,  solid  panicles  of  varJou* 
Unda,  Micb  a»  fat  or  eariiiiac,  pmeut  in  the  pliuma,  and  prolwbly  digcut 
Mda  of  thno  particlca  u  are  uulrilious.  ItuI  if  ihev  iu(Cfi»t  iheM  xilid 
etatUn  ibry  iintlably  abn  carry  out  the  easier  toak  0!*  inf(e«ling  diawlvud 
BtatMca.  li^.  however,  ibi-y  thua  take  iu.  they  niiist  abo  give  out ;  and  Ihua 
br  llw  rvmiival  on  the  oue  huud  of  variotin  niil»lanctA  from  the  plainui, 
aod  bj  the  addition  ou  tite  other  hiind  of  othrni.  they  niuat  be  iMnliually 
tafliMBdnK  the  plaama.  We  have  aln-iuty  :iuiil  that  thr  nhite  oorpuH-lr*  in 
lfc»d  U4iad  a*  ttiey  dio  are  aupiXM^d  to  pliiy  un  imji-irtnnt  jMrt  in  thv  clot- 
ifnif  of  bkiod :  Biniilorly  they  may  during  their  nhiJc  life  be  engngiHl  tg 
t^rr*''"'  ■■•<\  rhangn  in  the  pmleiilit  of  tlic  plutnin  which  ihi  not  lead  lo 
di-'  which  prepare  them  for  their  vnri<m»  uh'^  iu  tb<*  body. 

r,>.u-..--h.<^«l  facia  alforil  Mi)p|Hirl  to  Ihii' vivw.  TbcdiMMue  callmJ  leiicn- 
ntbcoiia  (or  Inkieniia)  is  chamcli-riccd  by  an  incivaev  of  ibe  white  corpua- 
cin,  both  absolute  and  relative  to  the  reil  cor|>ii»claa,  the  incrvaae,  due  to 
■a  sai;nenl«d  production  or  poosibly  (o  a  rrtarded  dostruciioti.  being  ut 
tinea  m  xnul  ai  to  |.iv<>  thu  blood  a  iiinkieh-gmy  nppeaimnce,  like  tlut  of 
Uoad  aispd  with  pus.  We  accordingly  liml  that  in  lliia  diauw  the  plasma 
if  to  Rtaoy  wavH  pr<ifoundlv  alfevt«d  and  fails  to  noiiri^  the  tisuea.  Aa 
a  ftirtWr  illui-lratiun  of  tbe  pomble  acltou  of  the  white  eorpusclca  we 
mmf  (talir  tliat,  acciinliiig  lo  ^>me  ob^rvers  iu  cert^iiu  diseasea  in  which 
•imt«  orgnnumi'  micIi  ns  bacteria  make  iJieir  api>e«>auoe  in  tbe  bli>od, 
Iba  white  mrpuMrlra  "  lake  up"  ihew  baderiu  into  their  subMaaoe,  aod  tbaa 
pvMbahiT,  hv  irxeniog  tin  influence  on  ihem,  modify  the  coarse  of  tbe  dbtan 
«f  wb><^  ihoe  organism*  ara  tl>e  ««sealiu)  cause. 


BLOOD. 

If  ttiu  while  uorputcJcs  are  thus  eugugtd  during  lli«lr  life  in  carryiii);  fM 
iaiporUUit  Inliora,  vre  may  exiiert  ihcm  to  diiTi-r  in  a[>))eHrance  acoonjiiis  to 
their  CQD(liti»Ti.  Some  of  tliu  cur[»uid€M  arc  iipikcn  of  lu  "  faintly  or 
*'  finely"  graniilnr.  Otlior  MimiM^lm  are  niwkwi  nf  tut"  euanfcly  "  gmaulir. 
Iheirooll  Fiibntance  bcinu  l(M<Ivd  with  c»i)iipinioii»lv  diicrfie  graoults.  It 
may  bo,  uf  coiinfc,  thnt  tncra  nru  tw»  di»iinc't  klDcIs  of  corpuitdee,  baving 
dHfcmit  fttnctioiJH  ami  pmrnihly  diflVrent  origioa  and  histories;  Ixit  sioco 
intcnnedialc  fonnii  nrp  mtt  with  ontoinine  a  lew  cunru  gniniiln  only,  il  it 
more  prohnb)«  timl  llio  otic  tVm  ix  n  pbaso  of  the  olbrr;  ihni  a  faintly 
granufar  corpUHclp.  by  laklog  in  granuks  ftom  without  or  by  producing 
granules  within  itself  ae  product*  i>f  it."  mctabolitn),  may  become  a  coarcely 
granular  corposde, 

Wlicthtr.  however,  the  white  corpu«clc«  are  roally  all  of  one  kind, 
whetlier  they  ure  dilfereiit  kind»  jMrforming  dilTerent  functiona,  mait- 
preaent  he  left  au  open  question. 


Stood  Plaltkt*. 

§  33.  [n  a  drop  of  blood  oxamiued  with  care  immediately  after  renioi 
may  ho  f>ccit  a  Dombor  of  esveedingly  timall  bodies  ('into  3^  in  diamrlpr 
fircqiientlr  disc  shaped,  but  Dometiincti  of  a  rounded  <ir  irregular  furni,  hnini  _ 
geuooiu  in  apposrancr  when  quite  fresh,  but  apt  tn  aMiinie  a  faintly  gniiiiilar 

l^irct.  Tlier  are  culled  blrivd  platrlth,  or  itfooti 


|Ra  10. 


(tln'jHfu.     Tni-y  have  been  «ui>piK>i.il  bv  sonie  |M 
K'coniu  ilcvi-hjpi'il  into,  iind.'iiidrcd,  to  be  cnrijm 


een 

1 


HiiigfS  of,  the  red  curpufcle:',  and  lienrv  have 
been  called  lucmutoblnate ;   but    this  view  Iiiib 
not  been  confirmed  ;   indeed,  as  ne  hare  seen 
(S  27),  the  re«l  hse m a tob lasts,  or  developing 
corpuscles,  are  of  quite  a  difltrent  nature. 

They  speedily  uuder;;D  chaDRe  aOer  reninri 
from  the  hodv.  apparently  dissolvtug   in    ihu 

StasTDB ;  ihey  hrenk  Up,  part  of  their  Bubetjince 
isRppeariug,  uhile  the  r««t  beconiea  granular. 
Their  granular  remains  are  apt  to  run  togclhcr, 
forming  in  the  i)Ia§ma  the  shapeleda  inawes 
whirh  have  h-iig  Wen  knowu  nnu  descrilied  as 
■■  hinipx  of  proloplasm."  Br  appropriule  rw- 
ttgpiils,  huwever,  these  plaieleta  may  he  fixed 
and  EilaiiKst  in  the  ctiRililion  in  which  the^_ 
ajipear  afttT  leaving  the  bcnly.  ^M 

The  aiiliNtaiire  ei.ini[ia>ing  them  is  [leculiill^ 
and,  though  we  may  pvrhaM  ajicak  of  them  ua 
iHiOAisting  iif  living  nialeriiu,  tlieir  luitnre  is  at 
|>riiH-nt  mmcure.     They  mayhcscfn  within  the 
living  htoodve£Bels[Fig.  1(1],  and  tbercfitre  miiM  he  regarded  ss  real  parts 
the  blood,  and  not  as  pr*idiict»  of  the  change*  taking  place  in  blood  after 
has  been  ahvd. 

When  a  needle  or  thread  or  other  foreign  hotly  is  introduced  into  I 
interior  of  a  hlo^jdvevsel,  they  are  apt  to  collect  upon,  and,  indeed,  are  the 
precurMira  of  the  clot  which  in  most  cases  forms  around  the  ne^le  or  thread. 
They  are  abo  found  ia  the  tfiromf/i  or  pings  which  sometimes  form  iu  the 
bloodveiMb  as  tiUi  mult  of  diseaac  or  ioiury.  Indeed,  it  hu  been  main- 
tained that  what  are  called  whiU  thrombi  (to  dislingiiisb  them  from 


m«i!<  ilUKi-iri  I'm  Blriijip 

A.  network  «(  nhrlii.  tkiowa  anet 
WMbtiiii  aiaar  lbs  corT>uiclD»  Riiui 
«  |>rti>*nll»iicrt  blood  Ibkt  iMa  br«n 
■llcnrcrf  lo  cint:  maniF  of  llin  llln. 
Btmi  ndlHtc  Ifota  miitll  clum|B 
oftilowl  lilatflcu,  n  iftDiu  Otirrt. 
Uux)  cuH'UWln  ukI  vlciiicntury 
|«l1ICta  otIiIcKil  plnlFJDU  mltlilo 
a  >iiibU  lelu.) 


he 

I 


09 

M,  wlir4-li  ftrc  |>Iu^  of  cnr|>iif>c)««  anil  filirim  are  Jii  rtfalhr  aKi;ref;a- 
tiMu  of  MoimI  jilniolola:  nixl  for  various  r»uiiiiti>  IiIlhiiI  pluUileu  Imve  been 
•Oppond  tu  |ilitT  nn  im)Hiniiiil  jiiirt  in  tb^;  clottiug  of  bltiod,  rarrjing 
Mit  Um  work  wbifli,  iii  tlil>  riv|>ix't,  U  by  nlh«n  nltribiiicd  la  tlie  wbite 
eorpinlw.  Itut  no  vorr  (kfiiiiii*  xtaii-tiiKitt  mii  iit  prc^iit  hv-  madft  about 
Udi:  uid.  [lulaed,  tb«  origin  ati<l  wb>iU-  iinturc  of  Uhvw  bloin)  iiUielciU  a  at 
pnaMil  ofaMartf. 

TlIK   CniJIICAL   COMI-OMTIOK    OT    Bl^OI). 


1 91  We  n»Bjr  now  paas  brii-flir  in  review  the  chief  cberoical  clmrocK'n  of 
Uood,  reHMinbMnitg  aJway?  tlint^  ns  wo  hitvi;  nir«iu)y  urgod,  the  '-bief  I'heini- 
lal  iatunia  uf  blood  ar«  nUni'bed  to  ihv  oban^^  «  bicb  it  unilert;oo»  in  tbu 
wranU  tfaaiiw ;  these  will  be  cuoHidored  in  connection  with  each  tisHie  at  tbe 
BppT"  prist  r  place. 

T  ,•(!  siM'i-itic  K"'vitr  of  human  blood  i»  lOW,  varying  from  1045 

lo  I'  <  hin  till-  limiu  of  health. 

Tbr  rxTAction  of  blond  M  h  lloirii  from  (be  bloudreMcta  U  found  to  be  db- 
lioriK  tli..ii;;b  fifbly  alkaline.  If  a  dmphe  plaoeil  on  a  piac<!  of  faintly  red, 
ht^  I  liiniuit  paper,  and  then  wiped  utf,  a  Muc  »tuin  will  be  left 

li.- It   lilooil  cuntaiiu  a  cvrinin  ifuiintilv  of  gw^  vti.,  oxyt^i.  car- 

bonir  Bciil,  and  nitrogrn,  whii:!h  iirv  b4>Id  in  the  bluoil  in  n  [let'uliar  wav, 
whifh  vary  in  itiirvri-nt  kind-i  uf  blood,  and  »o  itcrvu  cfpuciAlIy  b>  dUlinj^idli 
arterial  fn>ni  veft«u>  blmid,  iiiid  which  iiiny  be  given  off  from  blooil  when 
esfwanl  to  an  atnioipher*-,  accord! nj,'  to  lh<-  composition  of  llnit  atmosphere. 
Tmm  gatea  of  blixHl  wi-  Fbnil  ntudy  in  ronnvetion  wilh  rvapinUion. 

the  oamtal  blood  con«iHi«  of  c^Tpiudet  and  ptntma. 

If  llMeDr|KHelw  be  suppcwod  to  retain  the  ani^iiol  of  water  proper  to  then). 
bland  iiuiy.  in  ^i-n«nil  ti-rnt*.  In-  iMii>>idi'nr<i  as  con^istio^'  bv  woighl  of  I'roa 
abmi  one-third  bi  oomewbal  lens  Ihnn  one-half  of  eorjiuiclea,  the  feat  being 
plaama.  As  we  have  alnauly  kch,  (he  Dumber  of  ciirpusclea  in  a  ajweinien 
of  hinod  i«  fr'uml  u>  vary  ennsiderably.  imt  onlv  in  different  aniuiaU  and  in 
diAnuit  inl*.  but  iu  the  aame  individual  at  dilferenl  times. 

Tbe  ;         '      -  rnudvtst  by  the  cloltinic  of  ibe  \>Wni  into  «^iim  and  fibriH, 

I  Si.  The  MTiiM  eoniaini  in  HH)  parts  : 


FrBtaM  tobMiMw 

hU.  vMWua  MtirwtivM,  asil  mliao  oinlUn 


■bnut  H  ort  p*rU. 
3  or  I  part. 
m      larta. 


Tlw  pnitiridi)  arv  pnrttgMtulin  anrl  >mim-tiibumin  (there  being  probaM/ 
than  lutp   kind  of  M!nim*atbiiM))u  I  in  varyiDK  proportion.     We  miij, 
p«H'*'-   r-niiihly  "peaking,  my  lliat  tbey  ifccur  in  about  equal  quaulitie*. 

'  <tis  iind  linking  nt  are  the  restilre  of  cloltinj*,  niaiwive  a»  appear* 

10  U  ..'■  •  -'-l  whii'h  \a  fiirme<l,  it  must  be  remembered  that  by  far  tbe  greater 
(ttrt  uf  ibc  clot  consists  of  corfHiselea.  The  amount  by  wei;gbl  of  Bbrin 
ranitired  to  bind  togeiber  a  number  of  corpusclei,  in  order  to  form  even 
a  larse.  tirra  clot,  ta  exceetliugly  small.  Ttiu*.  the  average  •piantitv  by 
■r'  "  '  :  'niii  in  buuiiiii  blood  is  <«id  lo  l»e  0.2  percent.;  tbe  amount,  bow- 
iin  W  obiaine'l  from  a  given  <|uautlty  of  pliumu  variea  extremely, 
ti>t  due  not  only  lo  circuinsCaneet  affecting  the  blooil,  but 
I  empluyed. 
l>  are  Manly,  excel)!  attar  a  nical  or  in  certain  palbolngical 
i  I  of  the  neutral  fiiU — ileario,  {lalmitin,  and  ob-io — with  a 
Y  ihi-ir  n -ji'Tlivo  nlkaliiie  woapt.  The  i>eculiar  cotuplex 
'  r.'  in  viTv  (uiill  'luantitic*  only :  ifae  amount  prcHQl  of  th« 


(be  ^:ll 

■f 


70 


BLOOD. 


peculiar  iilcobol  <'h<>1<«lenti ,  wliirli  hiiK  *a  fiitty  iin  npiminiiKN!,  is  al»n  sma 
Among  the  cxltaclivc^  jiriwiit  in  .iL-rum  niuy  W  [lut  ijohd  nearly  nil  th« 
nitrogi'iiotiii  nixl  ollii-r  i>tiii«liiiu'cii  nhifli  I'orm  lli«  i'xtriu?liv<'!>  of  the  btxlf  nod 
of  food,  riJc'li  B«  itn-ii.  kn  ntiii,  >ii^ar.  Iiu'ticacid.  tic.  A  very  InrgR  Diirnbrr 
of  tlic»c  Imvt  Item  di#iiiv(.r<d  in  ilii-  Moud  under  vitriquo  cirvuiiiKtaiirn.  (he 
cotixidcrntioti  of  which  niu^t  lie  IcfV  for  the  prcMiil,  The  peculiar  oddr  ttt 
blood  or  of  Ecnini  is  prol>atdy  duo  In  ihc  prcwtire  of  volatile  bodioB  of  tlic 
fatty  acid  wrie*.  The  laint  yellow  cidor  of  eeruin  it  duo  lo  a  K[iecial  yellow 
pij-ment.  The  tnoet  charactvriittic  aod  imporioDt  chetnical  feature  of  tbo 
saline  conGlitulioii  of  the  ecnim  is  the  pre|ii:<Dderaiice,  at  lea«t  in  man  and 
most  aniiiinli',  of  fodium  mltii  over  those  of  potiuwuni.  In  thb  mpvel  the 
aeruiu  offers  a  tnoikcd  conlrnsl  (o  the  corpuscles.  Lees  marked,  but  still 
Striking,  is  the  abuodnnce  of  chlorides  and  l)i«  poverty  of  phoepliates  in  the 
aeiuiD,  OS  compared  wilh  the  coqiufcle^  Tlie  mlti  inay  in  fact  briefly  b« 
described  ns  cuDsUliug  chielly  of  eu'liuin  chloride,  aitli  ioiue  amount  of 
sodiiiin  carboDste,  or  more  correctly  Midium  hii-arliuimte,  and  |ioia»iuiii 
chloride,  with  small  quaotiiien  of  mdiuin  uilphali',  Medium  ohiwphale,  cal- 
cium idioHphale.  and  ninK"^>"ni  phoq>hate:.  And  of  fvtn  tin-  small  <juan- 
lity  of  ]ih«»phati.-!i  found  in  the  aab,  part  of  the  yhfinyhunit  eiialti  in  (he 
•erum  ilnvlf,  DOl  as  a  phcitphnte,  but  an  phiisphiiriiH  in  »>nu'  orgfiiuic  hudy. 

§  36.  The  rtd  torpvtctt*  contain  le»  wiili-r  limn  the  H-ntm.  ihc  amount  of 
colid  tnalter  being  variou^y  Mtimat«'d  m  from  .'iO  tu -ll)  or  more  pt^r  ci-nt. 
Tho  solid*  arv  almcjat  entirely  organic  matter,  the  iiiorvnnic  salt*  amounting 
to  lt»«  than  I  jier  cent.  Of  the  iir^anic  matter  n^ain  hy  far  the  largt-r  jwrt 
coneiste  of  ha'muglohin.  In  I'lO  )inrT!i  of  ihc  driH  <irgnnic  matter  of  ''~' 
corpuRclcs  of  human  blood,  about  !H)  jiarlii  are  hn-nioglnhin,  about  8  part* 
proteid  euhnlanccs,  am)  nliout  '2  purls  niv  other  (ulwlnnccs.  Of  (he  last. 
Df  the  niosl  important,  forming  about  a  <]uortcr  of  them  and  apparcQtljr 
being  always  prexeiit,  is  tedlliiu.  Lliolesierin  appears  also  to  be  nonnslly 
jimeDi.  The  priiicida  which  fi>rDi  ihe  sironia  of  the  red  eorpusclee  ap]>e*r 
to  belong  chiefly  to  the  ulnliuliji  I'limily.  As  regards  the  inorganic  constitu- 
ents, the  corpuscles  are  diBlin;,-iiiabed  by  the  relative  abundance  of  ihe  walla 
of  polait-iuiu  and  of  |>h(L^|>baii'6,  This  at  leirnt  i»  the  ea^  in  man ;  the  re' 
tive  i|Uiiutilies  of  «odium  imd  polaiuitim  iu  the  corpuscle*  and  M-rum  reo 
tivvly  upgimr,  however,  to  vary  Ju  dilTerent  animals;  in  aoino  the  »i>d 
tnlle  life  in  excrr*  even  lU  llir  corpuscles. 

S  37.  The  pioteid  uialrix  of  the  whitr  rorptiiolrr  we  have  stated  t«  be 
Oomp<we«l  of  my  AMU  (or  an  nllieil  hmly  >,  |iiirnglohulin.  and  ponibly  other 
proteids.  The  nuclei  contain  nueli-in.  The?  while  onrjiiKiili-*  are  found  to 
contain,  in  ndditiou  to  proteid  material,  lecithin  and  olher  fa t»,  glycogen , 
eslractivcs  and  inorganic  salts,  there  being  in  the  asli,  as  in  that  of  the  red 
corpuscles,  a  preponderance  of  polassium  sidts  and  of  phosphates. 

The  main  faciN  of  interest  then  in  tho  chemical  eompo^itioo  of  the  blood 
arc  as  loliows;  The  red  corpuisclcs  consist  chic  tly  of  hu^mnglobin,  I'lie  organ  to 
•olids  of  Mrum  consist  portly  of  serum-albumin,  and  partly  of  iiaraglobuliu. 
Thcitcrum  or  plasma  conlntMs.io  man  at  leoM,  with  (lie  corpuM:W.  inasmuch 
n«  the  former  contains  ehii-tly  ehloridw  mid  sodium  salts,  whik*  the  latter  are 
richer  in  pbi^fphatcs  and  jioiaMiiiin  suits.  The  extraciiveti  uf  the  hluoil  are 
reninrlcahle  rather  for  tluir  nurnl>er  and  variability  than  for  iheir  almndaiicc^ 
the  mint  coDslaot  and  im[Hnlaut  heiiig  jierhaps  urea,  kreatin,  sugar, 
lactic  ncid. 


;>ari 

1 


waiia 
Hum 


rilK   gCAICTITV    ANlJ    IiISTRtBOTION    OF   THE   BLOOP.      71 


TiiK  Qt'ASTiTY  or  Blood.  as&  m  jytgrRMnmov  is  the  Body. 


,  38.  T1>. 


1.1 


whul« 


ayrtem 


ImImk*  •tnii'k  Wtni-eii  (be  lifsoes  whirli  | 
frofB.  lb*  bloM).  Tbiis  tlic  [inaoe  uf  llic  alimenUr;  »iial  larjii^ly  luld  lo  tliv 
blood  nier  odcI  tli«  mmerial  ilerivcd  from  food,  ivliik-  llie  extri-iory  Dfuiiuti 
larnly  Ukc  anar  water  itn'l  the  other  subet«iivea  ooDDlituiiu;;  lli«  fxc-ntioiis. 
OtMT  Uaaea  botli  i;iTe  and  lake  ;  aw)  the  consUlenble  dmiii  fnim  ihi'  UI'Mid 
tv  tbo  l^mph  sfincea  wliicli  takw  [iliuv  iu  the  cit[HllarM«  b  met  by  thu  flow  of 
lynpli  intu  ibe  jrreat  veina. 

Frun  (lie  mult  of  a  tew  nliierriiliuuji  oti  esociilcil  rnmiiialH  it  ba.i  \kkii 

candutlal  tlint  thu  Ifital  ({uaiitily  of  blimd  in  the  huiuuu  biHly  in  aWiit  ii^lli 

I  at  iba  bxily  wi-ijibt.     But  in  vnrinii.i  aiiiiiinla,  the  prupurtinn  of  the  weight 

I  at  ibe  b4<mi|  li>  that  nf  the  biolv  iiiin  lM>t-ti  f»iiiid  to  vary  vfry  c<>n«idvrnbly 

io  i)ifl«rriit  individiiaU;  and  prolinbly  thin  holds  giiod  lur  mim  iilsti,  nt  all 

rmu  aithin  ccrtuin  liniil.t. 

Id  ibr  uiiiip  individiinl  tlte  <iiiiintitv  prububly  doca  doI  vary  largely.  A 
MMldrti  dniio  iijmn  ihi-  water  of  (!»■  hl<>ml  by  Kftnt  aclivily  of  the  eserolorv 
MCkix.a*  )>j  {ifKfiiwdwriUin^.Qr  iinuddeii  ad'Hlioii  to  (he  niilerof  thu  bl<x>ii, 
M  by  dfinkini:  large  qnnntilice  of  wnter  nr  by  inJcc-liDg  Snid  iii(»  the  blmxl- 
rnarla,  i>  ni|>idly  coinpcDMtled  by  the  pMNiige  of  ntiter  from  the  liwiint  to 
the  hluoal,  nr  froin  the  blood  to  iho  tiMiics.  Aa  we  have  already  said,  (he 
IMMn  mtr  ojutiiiually  •trifiii^  to  ki'cp  up  an  average  coni|H»)tioii  of  the 
MomI,  anil  in  to  Aoin^  ke«p  np  an  average  qiinntity.  In  starvation  the  <|uaD- 
lity  land  i|ualUy  j  of  the  bloutl  b  nutintained  for  a  1uD(;  linie  at  the  ex{>enBe 
ft  Um  tinuts.  DO  that  uAer  eume  days'  deprivation  of  fwid  and  driuk.  while 
lfc«  fiU.  llw  muaclc*.  nod  nlher  tiiMiua  have  beeu  largely  diiuiuiihed,  the  ijiian- 
tity  of  Uood  rcmaiitt  nearly  the  tame. 

TWima]  i|Hiintily  or  blow)  preaeDi  In  nn  animal  body  la  eailmnted  in  the  fol- 
InwlBg  w*j :  S*  n\\t\i  litood  •»  jioHible  i*  alluircil  to  mvaiic  from  (lie  veatela ; 
tkU  U  Riv^urcl  flir(H.-t1y.  Tlie  rrurU  are  th«n  washed  out  with  water  or  normal 
miixtn  kJuiIixi.  hii'I  ibi;  wailiinjt*  cnrcrully  c»IIe(il«iL  mtxed.  iind  mcamred.  A 
kwnra  ijaaMiiy '•(  blmxl  U  diluted  nrilh  wiiler  ur  normal  Miline  solution  until  It 
paMMMM  ihc  saine  tint  as  a  measured  si^eciini-ii  of  (he  washliigit.  This  gires  the 
fg^auot  ■■■  1'  ■  ■!  'nr  rather  of  hfetnog lolling  in  ihe  nn-axir*'!  itiiecimen.  Trom  which 
iho  tMa  in  llir  vh'ile  wuhliiKu  u  cnlniUtn].    l.iutlf ,  the  whole  tiixly  la 

OnfWIj  t-  I  .  :iiitl  nB>b«d  free  from  bluml.  The  wuhiiif,'*  are  eollected  and 
ikavad.  ami  the  aiiii'Uiil  of  blood  in  iheni  ia  estliDaled.  at  before,  by  eomparlaod 
«teb  a  Meciaieii  ni'  diiiiinl  bl'ioil.  The  ijuantity  or  blood,  a«  caleulatml  from  tho 
Xmn  wMting*,  together  with  the  awapad  aud  directly  ineaurod  blood,  giro*  tlio 


I  ifoafitiiy  >>(  biwid  in  ihe  body. 

The  »ribAd  U  not  free  frotn  M>jte(loB»,  but  other  metlioda  are  even  more  Im- 
P#rCKt. 

Tbr  blood  b  in  round  iiuinber*  dolribiited  as  follow*  : 
Abuai  niMyfourth  in  the  heart,  lungs,  birgo  nrtericH  and  vciiu. 
About  one-fourth  in  iIk-  liver. 
Aboal  (mthfuurib  in  ihu  skdeial  muMk*. 
Abosi  ona-fiwrlh  in  the  other  orguifl. 

^vrm  in  (lie  heart  and  |;reai  bloodvwoela  ihfl  b)owl  is  simply  in  transit, 

^•mt\  nndcrff'itnK  niiy  );reat  (-hiuijcea  (and  in  llio  lungs,  as  far  as  we  know, 

■  !  (o  tt«pirali>ry  rhajiiceH).  il  fulIowH  that  the  allerulions  whirh 

II  ibe  IiIoihI  [iiirainK  throojth  the  liver  uimI  iikelelal  uiu«el(«  far 

CMwed  thorn  arhicfa  occur  in  tha  ml  ul^lh«  body. 


CHAPTER   II. 


THE  CONTKACTILB  TISSUBS. 

^  39.  In  otflvr  tbBt  (be  bltiiHl  may  nouriiib  lli«  aereral  ttMua*  il  »  ■ 
lo  and  from  thum  )>v  tli'^  voni'iilar  iii^i'luiiiuin ;  ami  (hii  nuriagc  i*!; 
&ctiT«  niovoiDciitit.     1(1  onk'r  that  iIk!  I>U»)iI  mitr  (ulvqiintfly  nCKircfli  ihc 
sues,  it  tnuRt  lie  rcpIcniKWl  by  futHi  from  the  nbniciittiry  canal,  and  nurif 
fmru  Wtc  by  the- rxcrclory  or);uii* ',  nii>)  )i<itli  thi-wr  |mtcnM»  ciilAit  moi 
ni«Dt8.     IIcnc«  bolbrv  n«  jiiyicol'^I  furllicr  wa  niuHl  HUidy  some  of  tbe  geoer 
chankcilere  of  tho  inovcRicni«  of  iho  botly. 

M<Ml  of  tlie  movomcule  of  ilie  body  nro  cnrried  out  Ity  mMm  of  tbe  mi 
olra  of  l)i«  Inink  nnd  lituba,  whiub  beiii;;  connccled  nilli  th«  flkeliHftn  are 
fnH|U«otlir  called  skoletnl  muaclee.  A  fikeleta)  muscle  wfaen  subjected  to 
wrlain  infliienoes  suddenly  aborifiis.  briiiffiii);  its  two  etub  nearer  together ; 
and  it !»  tli<'  Hborteuing,  ai^liu;;  ujiun  varioris  bony  levers  or  by  liotp  of  odier 
tueohunR-nl  iirrnnKeiueuu.  wliicli  itntduccs  the  inoven»nt.  i>ticli  ■  triniHtnu-y 
febortciiiRg.  cidb^l  liirtb  by  iH-rtniti  mfluenoe*,  and  due  as  westinll  iM*  to  clt!uigM| 
taking  |>Itic>'  in  the  iniiNciiliir  liiuiie  forming  the  chief  part  of  the  ii)ii.'>f|i:,  ^| 
technically  cnllcil  a  foHtraidwn  of  tbo  muxdv:  and  llit-  niUMUiliir  Imiip  isfpoken 
of  lu  a  coDtrnclilc  ti»uv.  Tbc  hnnrt  in  cbittfly  cMinii'isnl  iif  muKctibir  ti«*iie. 
ditfcring  in  cortnin  minor  foittunt*  fmm  tin'  mii»ciilur  tiMuo  of  the  Kkplciiil 
miiDcl«^,  and  tbe  bent  of  the  beurt  is  eiueniiiilly  a  conlmction  of  tbe  iiiUMular 
tisiuc  conirMKinK  it,  a  .ihortenin^  of  the  peculiar  muwular  Rbm  of  which  the 
benrt  Is  obiclly  made  up.  The  luuvumeiils  of  tlie  atiinentary  cannl  and  of 
many  olbvr  organs  are  similarly  tbo  results  of  Ihe  contnu-tinn  of  tbe  njuf- 
eular  tissue  entering  intu  lb«  coraptMltion  of  thrise  orgnno,  of  the  iihorloning 
of  certatD  muscular  fibre*  built  up  into  thiMC  orgaiu.  In  fact,  almml  all  tho 
movements  of  the  body  aro  the  result  of  the  eontraetioD  of  muacalor  fibrMt 
of  various  nature  and  variously  dUp'Morl. 

Some  few  movements,  howevor.  am  carried  out  by  »tnieMir«>«  which  mnnoC 
Ih-  called  muscular.  TbiiH,  in  the  piiluionarr  posfunt  nixl  elsewhere,  more- 
lupnt  b  eflbcted  by  means  of  cilin  atlaeliC'I  to  cpitheliuni  cells:  and  else- 
where, W  in  the  case  of  tlie  nii;;r»ling  white  corpuscles  i>f  the  bloud,  Iraas- 
ftrcnec  from  place  to  place  in  the  body  is  brou^^ht  about  by  amabolfl 
mo\-ementM.  But  as  we  shall  see  the  changes  in  the  epithelium  cell  dH 
while  corpuscle  which  are  at  Ihe  bottom  of  ciliary  or  amiebuid  moveneata 
are,  in  all  probability,  fundamentally  tbe  same  as  thow  which  take  pinoo  ' 
n  mu«citlar  libre  wb(*n  it  contraoU :  lliey  arc  of  the  nature  of  a  cnnirartin 
and  hence  we  may  Npeak  of  all  tliuie  Ojt  diflervnt  forujti  of  canlrnctilr  tissu^ 

Of  all  these  variouH  finon  of  cuntraclile  liMue,  the  skeletal  muscles, 
account  of  the  more  complete  devL-lopmeiit  of  their  functions,  will  l>e  holt 
studied  tirsl ;  the  others,  on  account  of  Lbeir  very  ninipticily,  are  in  many 
respects  les  nlisfiictorily  unden>t(iml, 

All  the  ordinary  skeli>tal  muxeUv  nrv  onnected  witli  nerrn.    We  have  i 
reoaoa  for  thinking  that  they  are  thrown  into  contraetioo,  under  nur 
conditions,  oiherwiH*  ihau  by  the  agency  of  nerves.  ^ 

Mu»cles  and  iterves  being  thus  so  clowly  allied,  and  having  bcsidea  M 
many  nro|>ertictt  in  common,  it  will  conduce  to  clearness  and  brevity  if  w< 
treat  them  logother. 


eat* 
o  ^_ 

isufl 

:S 

...any 
veifl 


TiTK  piiffxoiiKirA  or  iidsclb  avd  kbrte. 


73 


I 


I 


^^^V  Tub-  ruE:(oMe.vA  of  Musclb  and  Nemvk. 

^F  Miuciilor  and  Jt^moHi  IiTtlMiily. 

i  40.  Tb«  •ItolcWl  uu»clet  of  u  Trog,  th«  tmiii  aiid  spinal  cord  of  which 
Wt*  beta  docnmd,  do  uot  sxbibil  tny  »pi>iitanei>ii3  Diovemenu  or  contnu> 
llniM.  CTCB  thoagh  lh«  nervm  he  oihorniK  iiuitv  inluut.  Jjifl  uDdietiirbml, 
tba  vboU  IkmIjt  mny  dwomium;  wiihuui  auy  ooalruocion  of  May  of  Um 
•kfttfjil  na»cl«)i  hiiving  bccii  witmwfil.  Neither  the  akeletal  iuuscl«e  nor 
lb*  nvrmt  di»lrihulrd  lo  thpin  ihhw^ss  mu'  powttr  ul  auloainLic  action. 

If.  hiifitiTer,  ft  tiiuvcic  1>«  hiiil  Iwiv  ami  he  more  or  Ivm  violently  dis- 
turbed—ilT,  for  iiuUiiM-.  il  Ih-  pinched,  or  tuuchud  with  ii  hot  wire,  ur  brought 
isln  niDtmct  nilh  ivrtuin  chvmicnl  milietanevM,  or  ttuhjeclAd  to  the  a<;tiun  of 
(aK-snlr  nirn>nta— il  will  move,  thnt  is.  cuntrnol,  whenever  it  b  thus  dis- 
torbnl.  Th<Hi};h  nol  exhibilin^'  miy  epontaiieoiiA  iiotivity,  iho  muvcle  id  (imd 
a«itiatw>  for  some  time  afl«r  the  j^oiwriil  dejih  of  lh>:  nuimiil  to  be)  irritubU. 
Tbouffa  il  remaiui  <)uilo  lukiti-cnt  whoii  lell  untouched,  its  iiDironi  are  then 
domBal  (inly— uitt  ahwiil.  Thf««  require  lo  he  routed  nr  "tftimulntMl"  bj 
•oOM  ebattge  or  disltirbunoe  in  urdt^r  thai  ihcy  ttiny  nuin!l!vt  thrmselve*. 
Tb«  MibtUDoe*  or  «|[enta  which  are  thus,  able  to  evoke  ihc  aclivily  of  an 
irritable  miurle  are  ^j>i>keii  of  as  Himuli. 

But  to  prtMluc*  a  cvnlroctiun  tn  a  muscle  the  Btlmuhia  n«ed  not  hv  applied 

dinBcUr  to  the  muiich-;  il  may  he  applied  indir«ctly  hjr  mcnana  of  tbi-  ner%-«, 

TblM.  if  lh«  trunk  i>f  a  nt^rve  Ite  pinched,  or  Mibjeclml  lu  xudden  heat,  or 

dipp^    in  crrlnin  cheniioal  niilMtaiMes,  or  acted  U]>->n  hv  various  calvnniu 

canvnu.  ruiitrartiuui  are  wen  in  ibe  munlea  lo  which  brancbee  of  tJue  uervo 

aiv  dtrtributcd. 

_       The  iit-rvi.-,  like  the  muscle,  is  irritable :  it  U  throwp  into  a  state  of  actlTity 

■  bv  a  ^iniulua;   bul,  unltkc  (be  muscJc,  It  dom  not  iltcif  ooiilncL    The 

^Kg£ni   '       '  'vs  not  (riv«  riio  in  the  ncrrc  to  any  visible  change  of  fiirm:  but 

^Hb:  -  of  M>me  kind  or  other  are  Ht  up  and  pmpagmted  along  th« 

^^^^re  U'.'«<n  to  the  miuclo  is  sliowa  by  the  fact  that  the  muRclc  conlracU 

mUmt  ■  pArt  of  the  aent  at  some  distance  from  itself  is  stimulated.     B<Mb 

nemr  and  nuitole  are  irritablv.  hul  only  the  muBi-Ie  is  contractile— i.r,,  raani- 

tmta  ita  irrir utility  hr  a  coulractiou.     The  nerve  maniftnls  its  irritability  by 

itj[  [taclf,  without  any   ri&ible  alleraiiun  of  form,  ocrtaia 

<   :.'«  vet  up  hy  the  stimulus.     We  shall  cull  tbeee  cbaogca 

■  (has  prwtwgat«il  along  a  nerve,  *'  nervous  impulses." 
f  41.  Wt  Iwe  slalM  ahovr  thai  the  mii*cle  ruay  lie  Uirown  into  conlrac- 
linaa  by  Mimnli  appliitl  din-ctly  tu  itself.  Kui  It  miKhl  fairly  he  nrf<tA  that 
lb«  nntnictioMi  so  pr<><lni-4Hl  are  in  rcsility  due  lo  the  fact  that  tlw  stiroulos, 
aliboagfa  n{fparenlly  applied  direnlly  to  this  muncle,  in  alVer  all  brought  to 
b<ar  on  sunte  or  i>lh«ir  of  the  many  fim:  nurvn-bninchtii,  which  as  we  shall 
«*«  arr  abiinduni  in  ihe  mu»cle,  piuvini;  amung  anil  bc*irevn  the  niUHcular 
Ohw,  (n  which  th»y  fimilly  end.  The  fdlowing  facl«.  however,  go  fsr  to 
ptwc  that  Ihe  nuscular  fibres  iheniM-lvcs  arc  capable  of  being  directly 
«tiBOl•^  '  '*'  I'i  the  intervention  of  any  ncrv«s:  Wlicn  a  frog  (or  other 
aninal  ed  with  urari.  the  uctves  may  b«  subjectcal  to  the  slrongc«t 

■linali  ><  i::l  'Ui  i.-iuihiu^  any  contractions  in  the  muscles  lo  which  they  arc 
dJtfHhutnl ;  yet  cvi'ii  .irdinary  stimdii,  applieil  dir*;clly  to  the  innsclc,  readily 
eonlractioni.  It'.  Ix-fore  intr>idiicin){  the  urari  into  the  t>ystcm,  a  lies* 
ht-  p«M«<l  iin<tcn»-nth  the  »>-intic  norve  in  one  le^— for  instance,  Uie 
!  Iriiwn  lightly  muml  the  wh'ile  leg  lo  the  eichision  of  the  nerve. 
Hi-  '<:   thai  the  urari  whi'n  inji-clisl  into  the  luok  of  the  animal  nill 

faia  Kvsa  to  the  Hgbl  sciatic  iien'e  above  the  ligature,  bul  uot  below,  while 


74 


THB   CONTRACTILE   TISSUKS. 


it  nil)  huve  frco  accHs  tu  the  r^st  uf  tlie  body,  includtiig  llic  ivlio)« 
sciatic.  If,  as  good  as  the  iiniri  lias  taken  cllect,  the  two  sciatic  nervei< 
Btiraillated,  uo  niovemeat  of  llie  left  le;;  nill  be  jirodiiced  by  ^tintulnling  if 
left  Bciatic,  vfliereaa  stront;  foniractious  of  the  luuseles  nf  the  riybl  le|f  below 
the  licsliire  will  follow  eiimulHtion  of  the  right  aciattc,  wlKther  the  uerve  be 
MiiuuTiilod  almve  or  b«luw  Ihe  ligature.  Now,  BiDce  tite  iip|>er  parla  of  both 
9dati<»  lire  i-cjually  expoeed  to  tlic  action  of  the  poituttj,  it  u  dear  that  the 
(iiiliire  of  llic  left  nerve  to  cause  coutrai'lion  i.-<  tint  Httribnliilik  to  aiiy  cbajige 
liiiTiti/  liikt^ii  iiliicv  t:j  the  iijijier  purliuM  of  the  iiltvc,  eliae  why  Hhould  uqfl 
tbr  ri}{hl,  whifli  lins  in  ltd  ii]ii>er  [xiriion  liri.*n  c({UHlly  rxpoicd  lu  the  adioifl 
of  thr  poiiMm,  aU'i  fail?  Kvideiilty  li'e  poi»iin  ncl#  on  Mumi-  |>arta  of  ll>e 
ncrvo  loKvr  dunn.  If  a  single  niiL^clv  Wi  removed  from  the  t'irculatioii  (by 
li^turing  ilK  ljliKidv*wi'lj'J,  previous  lo  the  poisoning  with  iirari.  that  wutcte 
nru)  coiitJttct  whc-n  nny  pnrt  of  the  nerve  going  to  it  it  stJmiilnti-d,  ihotigh  iio 
other  muscle  ill  the  Wly  will  contract  when  its  nene  if  KtiniMliil>.il.  Hi-re 
the  whole  nerx-e  right  dovni  tu  the  muscle  baa  been  exposed  lo  the  action  of 
the  potwn.  and  yet  it  has  lost  none  of  its  poner  over  the  muscle.  On  the 
other  hand,  if  tbe  muscle  be  allowed  to  retuain  iu  the  body,  and  su  be 
exposed  to  tbe  action  of  the  poison,  but  tbe  Dcrve  be  divided  bigh  up  and  tbe 

Jnrtcoiinccied  with  tbe  miiscte  gently  lifted  uji  before  Ihe  urari  is  intto- 
uoed  into  tlie  ayttem.  so  that  no  blood  flown  to  it  ami  so  that  it  is  protedeit 
from  the  Inltnonco  of  the  poison,  stimulation  of  the  iiLTve  will  be  found  lo 
pniduce  no  ciuilraetioua  in  Ihe  muscle,  though  ntimuli  applied  ilireclly  to 
the  niiibclv  III  once  cauw*  it  to  i-oniraet.  From  tlicse  facia  it  b  dear  that 
uniri  {HiiHiofl  the  erdii  nt  tlx-  nervt^  tvllhin  the  muiicle  long  before  it  alTects 
the  trunk  ;  and  it  in  cxceedinj'ly  probubli;  that  it  U  the-  very  extreme  ends  of 
tbe  nervcn  (noRiihly  the  enil-|>liitra.  or  {Kieuliar  xtriii'tnnit  in  which  the  nerve 
Hhm  end  in  the  muscular  tibrcs.  for  urari  poisoning,  at  least  when  pro- 
found, causes  a  slight  but  yet  dislinclly  recojijnizahlo  cHect  in  the  inicn> 
Mopic  appearance  of  these  siructures)  which  are  aflecled.  The  phcuomeDii 
of  uniri  poboning,  theretbre,  go  far  to  prove  that  muselea  are  capable  of 
being  made  to  contract  by  slimuli  applied  ilireclly  Iu  the  muscular  fibres 
lliemselvcH;  and  tbcrv  ure  other  faels  which  support  ibis  view. 

$  48.  When,  io  a  rec«nlly  killeil  Ihijr,  we  i<timulale  by  various  means  ai 
in  various  ways  tbe  uiuHcleit  and  nerves,  it  will  ht:  obw-rved  that  the  mov 
mentd  thus  produced,  though  very  varioun.  may  bo  distinguUhed  lo  be  of 
two  kind*.     On  ihc  one  hand,  the  ri,i<uU  may  be  n  mere  twitch,  lu  it  were, 
of  thii  or  thai  mur>clc;  on  the  »lher  bitnd,  one  or  more  muscles  may  remain 
sliortoned  or  coolractci!  for  a  ['■>ll*id^^lbU■  lime — n  limb,  for  inslanee.  being 
miscd  upor  stretched  out.  nnd  kept  raised  up  or  stnMched  oul   fnr  many 
seconds.     And  we  lind.  upon  cxiiminiitiou.  ihiil  a  stimulus  may  1h-  apptitu 
either  in  such  a  way  as  lo  produce  n  mere  Iwilch,  a  passing  rajiid  cotilro^ 
tion  which  is  over  iind  gone  in  a  fraction  of  a  second,  or  in  such  a  way  lu  (O 
kcci>  ihe  muscle  shortened  or  conlriicted  for  as  long  a  lime  as,  up  to  oertaia 
liiuils.'we  may  choose.     The  mere  twitch  is  called  a  t'niyle or sim}>{K  miwru|^| 
(lonlraftion  :  the  sustained  contraction,  which,  as  we  shall  s«e,  is  really  t^l 
result  of  rapidly  re|iealed  tiimple  contractions,  is  calkvl  a  Manie  Mntriuiitm. 

§43.  [n  onler  to  siudy  ibefie  contractions  adeipiately,  wc  must  hav 
recourse  to  the  "graphic  meiboil,"  OS  it  is  called,  aud  obliiin  a  tracing 
other  record  of  llic  change  i>f  form  of  tlie  muscle.  To  do  thU  coDvenieullj 
it  is  best  to  o|>erale  with  a  muscle  isolated  fmni  the  n-*l  nf  the  body  of  A 
recently  killed  animal,  and  ciirefully  jircpurcd  in  >uch  n  way  a#  lo  remain 
irriinbti'  for  some  time.  The  niusclci'  "f  pold-bloodcil  iininiala  ronmin  irri- 
table after  r^innval  from  the  Imdy  far  UmgtT  tbnn  those  of  warm-hl<Mi<lcd 
aniniiiU,  uml  hiiice  those  of  ihe  frcg  iire  generally  made  use  of     Wo  shall 


1 


♦BK   rnE.VOMBS'A   or    MUSCLB   AXn   SERVE. 

tlitHT  piwtiiilv  ifir  ci>n'litii>D*  whicli  ili'inrmim-  thU  mninirnamv  of  the  iiri- 
tability  uf  muH-lc*  ami  imti'o!  »(\vt  n-movnl  fmni  thv  bi.xiy, 

A  ntMelf  thus  iMiUlt-il.  with  ils  dctvp  kft  Hllsclird  to  it,  is  railed  a 
m^utU'm'ryr  frrpamlioH.  Tlie  iiK«t  Cf>nvnii(iil  mufcle  for  lliia  [lUrpoee  in 
Um  tng  t*,  pn"!)*!*.  iW  gatlrocncmiiif^  which  shoiili]  be  diswded  uut  eo  ts 
lo  IrsTi'  rarvfiilK  pnccrvnl  the  ntlmch merit  to  th«  feniiir  ubuve, kiiuc  porlioa 
of  %bt  t<-nJifn  I  lrnil()-j\chillUl  Iioliiw,  and  u  oonudcrublt;  Icufrlh  ot'tbe  »dalic 
mrr*  kiUi  iu  btsiK-h«a  p'iti];  lu  tli«  luiiad^.    <Fif;.  1].) 

1^,.  II. 


•ff 


.4a. 


Sp>V 

A  MuruMitsvK  l*BKr«iunuii. 
IkB  ■»■>*.  «w«nKa«iilUi  of  (K* ;  ■.  Ibe  w4MK-  nm*.  «l:  lli«  Iinwkn  Mna  rui  imB;  exixpt 
mfftjtnf  ilin  n><««l<  ,  /,  Inoiir:  it.  riaiiip:  L«-.  •nnlo-AcliUlli .  it-f-.t'Oiol  •|ii»I  niisL 

^L^SM.  We  may  nfipiv In  tut'h  n  niusclt^nerrv  pr«psratioii  the  rnrioua  kinds 
^■^^tali  ajKik^ii  III'  iiliiii'r  ;  iiirrhiinind,  mrh  m  iitiikii)];  or  piurhing ;  iher- 
^^I^Kck  a*  lud'li-it  hcnlifi^  :  i-lM-niical,  rucb  lU'  aciil^  or  ntlior  wtive  dwini- 
■     «ail  fnWlnii(v»>.  or  clrctriciil ;  iiii<i  iIk-j*  wo  nmr  apptv  either  l«  the  intu<cli> 

IdinTlW  <ir  In  ihn  wrvr.  ihtu  iitr<>>-tin^  ihv  inii>cl«  inOirectljr.  Of  nil  lliew 
•Itntuli  Viv  fitr  lb<-  nimt  cunvi-iiiriit  l'r>r  ^^eni-nit  iiurpOMS  are  cleclrirat  »uniuli 
of  T«ri'iu»  kind-  ;  mid  lh«-»*.  cswpl  fiT  (jH-cisi  piiqioK*,  nrc  hvA  appli<^  lo 
IIm  Denr«,  aitd  n'>t  •lirM-tly  to  tW  iiiiim-1i-. 
Of  «l«ctri<.'nl  atiiituli,  ngaiii,  ihc  rurrcDtn,  «»  they  ere  nlled,  gCDvnitnl  by 
m  voltftW  ovll,  itrv  aw^t  cv>nv('niciit.  lhi>U[,di  ihc  elorlririty  gcui-mtcil  bv  a 
rvtBling  mA);ii'-l.  or  Uuil  iinxliieol  by  rrii-tiiMi  mny  tw  tniploynl.  MalciDg 
iwe  of  K  wH  <>r  ImiTy  of  rclla— DunittirK.  Gruvc'fi.  l.«4'liitich£,  or  any  olbor 
— ««  mufi  di*iin|;iii»li  bclWMii  ibe  current  prvduwd  by  lh«  veil  ilsolf,  tbo 
eonManl  rurmtl,  il*  ««  «lmll  call  it,  ami  the  iiuliu^-d  nirrvjit  ohlaioed  fmni 
lb*  conMAtit  rurrrnt  by  m«unB  of  u»  induction  cd),  u  It  i«  colled  ;  fur  the 
{Ajifetogit'Bl  i-ilfcts  of  [bu  two  kinds  of  L-urrent  are  in  many  ways  diDcreut. 

It  naj,  |>rrlia|Mi,  bi>  worth  irLilp  li>  rtmind  the  rcxlrr  uf  the  rollowini;  facia: 
In  a  galtaDic  battery,  ihir  luluiante  (jilatc  of  lioc,  lur  icilaof e)  iiliich  U  trlnl 
npno  and  iiwd  up  by  the  liquid  ia  raiird  Ibe  potitirt  clrmeDt.  anil  Ibe  Mibitauce 


76 


THE    OONTBACTILK    TISSUES. 


which  Ih  not  10  acted  ii)>oii  aoiluDBd  up(|)]Ht«,cic..  orco))per.  pUUiiiim.or  outiol 
elv.)  is  called  tlie  ntffattie  olvmdnt.  A  gmlvnnic  action  in  Ret  Ufi  wlirn  tlio  jKnitin 
(nine)  nnil  thr  n«galivo  (copper)  eleiaonta  nro  conceiTitHl  oubido  the  iMUery  by 
•omfl  coniluclirig  material,  •ucb  lu  a  wire,  and  (b«  curredt  U  aaid  U  flow  in  a  cir- 
eult  or  circle  from  Ibe  xIdc  or  poBitlvc  element  ta  itie  oojiper  or  negative  element 
iiutdi  iKe  hatttnj,  and  then  froin  tlie  oopmr  or  nwatlve  element  tiack  to  the  linc 
or  poailive  elemool  Ihroitgh  Ihi^  wire  ouMV^r  the  balirry.  If  the  coaductiog  wire 
bv  cut  llirnuKli.  the  ciirtcnt  ccuscs  la  flow ;  but  If  the  cut  enOa  he  brought  into 
coiiLact,  the  current  in  rcf-fttablitbed  aod  coutiiiues  to  Uuw  ao  lui^  aa  the  coniai-i 
U  good.  The  end*  of  ibe  wirea  are  called  "  polm,"  or  wben  uaed  for  pliyaiological 
purpose*,  Id  wliich  case  ihoy  any  be  fashioned  in  varioui  wajra,  are  spoken  of  ai 
tietlroda.  Wbcn  the  pnlm  nro  brouffbt  inln  cnntact  or  are  connccird  by  fitne 
conducting  lunteriul,  ^ilvuoic  n<:ti(in  is  set  uii.  mid  the  current  Buwi  Ibroujch  (be 
bailer;^  aod  wires;  ihii  ia  spoken  of  at  "making;  ibe  c(irr<!nt"or  '' ciHupIetinr  or 
cloaing  the  circuit."  U'hen  the  poles  nic  (Iniwn  ajmrt.  from  each  other,  or  wncn 
tODie  non-condurting  material  is  ititcrposeil  between  thum,  the  Knlvaoie  action  u 
arrMted:  thisi*  npoken  of  a*  "breakinir  the  current"  or"  opening  lliecircaiL"  The 
current  panMa  froui  tJie  wire  cuanectea  with  the  negative  (copper)  element  In  the 
baiterrlo  the  wire  coitiiecledwitbthei>oritIve(Kiiiu)elGinenl  in  ibebaKety  :  hence. 
^« polocoonected  with  lhocopper(n<ffAtive)  element  is  called  th'-z'tMi'iV pole,  and 
that  coDDOCtcd  with  the  linc  (poaitive)  cli'tnenl  i*  called  the  it'^iiitv  pule.  When 
uaed  for  phyaiologienl  purpoiea  the  piuiitivc  ixile  betMnK-a  the  posiiiire  rlcclrudc. 
aud  the  negative  poltr  the  iieKHllre  electrode.  The  pii^llve  electrode  is  often 
epokeu  of  aa  the  imo<U  (ann,  up),  and  the  ncgntive  electrode  aa  the  kaihtdi  (kata, 
down). 

A  piece  of  riorre  of  ordinary  length,  though  not  a  good  coodactor,  ia  atill  ■ 
coaduclor,  and  when  placed  on  the  eleciroilea  iMinpluioe  the  oircnll.  permiiting 
ihc  current  to  paai  ibroUKh  it;  in  order  lo  remove  the  nerve  froiu  the  iullitcnce 
of  the  current  it  must  beliftod  oCT  from  the  vloctrodca.  Tbii  is  obviously  inoon- 
vcnient ;  and  hence  it  is  uxual  to  nrranfce  a  meana  of  opening  nr  rlooiinii;  the  cir* 
cult  at  (time  puint  along  one  of  tbe  two  wire*.  This  may  be  done  in  vnrioua  war* 
—by  faateiiing  one  part  of  the  wire  into  a  cup  of  mercury,  nnd  >o  by  dippini;  the 
other  »art  of  the  iriro  int>>  the  cup  to  close  tbe  circuit  anil  make  the'  mrreot.  and 
by  lining  it  out  nf  tlii?  mercury  to  open  Ibe  circuit  anil  break  the  current;  or  by 
armngiiig  bctwcAu  the  tw'i  p.irts  of  the  wirw  a  movable  bridge  of  good  con- 
ducting material,  aach  us  braitt,  which  can  be  put  down  to  clone  the  circnit  or 
raised  up  to  open  the  circuit ;  or  in  other  ways.  Such  a  meniu  of  el'Ming  and 
opening  a  circuit,  and  ao  of  making  or  breaking  a  current,  L«  called  a  kry. 

A  key  whidi  is  frequently  used  by  physiologiata  goes  by  tbe  name  of  Du  B'lls- 
Reymond's  key.  Thouitb  undtvirnbli'  iu  many  reapects.  it  hiu  Iho  adTaniage  that  il 
can  be  used  in  twodiifervnt  nrsT*:  when  arraoguaas  in  A.  t'ig.  12,  the  brass  hridj^e 
of  K.  the  key,  being  down,  and  forming  n  nieans  of  good  cuuduciiou  bctKi-en  t 
braas  platea  to  whirn  the  wires  are  •creive<l.  the  circnll  it  closed  and  the  cnrrc 
pasaea  from  thn  positive  pole  (end  of  the  negative  (copper)  element)  to  tbe  poi 
tire  elcctmde.  cir  anode.  An.,  ttirougb  the  nerve,  to  Ine  ntmlira  eloctrode, 
kathode.  K^ti..  uml  thence  bavk  to  tbe  negative  pole  (end  or  tbe  posi^ve  (aind. 
element)  in  the  bsttery;  nn  raising  tbe  braM  bridge,  the  circuit  i*  njiciied.  the 
correut  broken.  uikI  no  current  passes  tbrongb  the  electrode*.  Wben  arranged  as  in 
B.  if  the  bnus  bridge  bo  "  down."  the  rosiatance  oQered  bv  it  ia  so  (mall, eomp.-i red 
with  the  reiustance  ulTered  by  the  nerve  between  the  efectrodes,  that  the  whole 
current  from  the  battery  pWes  through  the  bridge  back  lo  the  battery,  and  none, 
or  onljr  an  inflnitetinial  p'lriinn.  pawes  into  the  nerve.  When,  on  the  irther  hand, 
tbe  bridge  is  raised,  and  so  the  conduction  beiweeu  tbe  two  sidett  <<ut|fended,  the 
current  is  not  ubli>  t'>  pu.ii  directly  from  one  side  to  the  other,  but  r^n  and  doee 
pM«  niong  tbe  wire  tliruuuh  the  nerve  back  lo  the  bntter>-.  Ilvncc,  in  srnuige- 
meot  A,  potting  down  the  key,"  a*  il  it  called,  nialcra  ii  current  io  the  nerv«, 
and  "raising"  or  "opening  thi>  key  "  break*  the  currenl.  In  arrangenent  B, 
hou'pver,  putting  d':iTrn  the  key  divorta  the  current  from  the  iierv*  by  aendlng  It 
tbrou;{h  lAc  bridge,  aud  so  back  tu  the  battery ;  the  current,  instead  of  making 
the  longer  cin-ult  througb  the  eleetrodw,  make*  tbe  sh'irier  circuit  tbroush  the 
key;  hence,  this  is  called  "short'clrculting,"  When  thi>  bridge  ia  miscdihe  cur- 
rent pMse*  through  the  nerve  on  the  eicctrodea.  Tbns,  "  putting  dowu  "  and 
"raising"  or"opening"  thckoy  havcooatrary  edect«  in  A  and  D.    In  B,  il  wlU_ 


I 


b«  afcNiTcd,  ili«  bnllvrr  U  nlirkra  M  work,  tli«  ciirtent  u  nlwa^H  IIoitIuk  tUhtt 
ikfwoith  Ut«  el»rtn>il«(l(er  up)  or  through  the  kcylkpy  donu);  m  A,ihel>ii«*ry 
ia  tMt  kt  wutk  ntiLil  tlie  otn-uii  i*  nude  67  [lulUnK  down  the  ivy.  And  in  mnny 
«M*  ll  U  drtirablc  tu  take.  «o  in  aptak.  a  Mmplv  of  ibe  current  while  the  bdtlcry 
k  in  (tall  ■wJnif.  rather  tbnn  Juh  •»  it  l)«fi»«  to  work,  Mori-ottr,  in  1)  tlie  elec- 
llvilra  Mr.  libra  Ibr  key  ii  dnirn.  wholly  ibiit  off  from  tlio  clirrDnt;  wherciw.  Ill 
A,  «b*n  U)»  k^j  in  up,  one  electrode  i>  •till  in  direct  connrriion  wiib  the  bitllery, 
•ad  thh  connection  Icailine  to  what  h  known  a*  unipulnr  acliim,  may  jtire  rimi  to 
■tinulaiiiiii  (if  iht  iirrve.     ilencc  tbc  ui«^  of  Ihe  key  iu  ibe  rorm  B. 

iJiliri  rutin*  of  kvy  may  be  uaod.  Thin, in  the  Moivc  key(r,  Fi^.  13)  oonlMt  ia 
k  Bwl*  by  iiraaiDE  down  a  lever  bamlle  ( An)  :  when  the  prmxiro  ■•  remoTtHl.  the 
taMfldlo,  dri*eit  ap  by  ■  (pTing,  hrcnki  contact.  In  ihe  Nrrangrmrnt  >liown  in  Ibe 
Inirv,  ooa  win  frmn  itie  bsiier>'  being  brought  to  the  binding  *«rev  6,  while  tbe 
bbirdJiiit  ecrew  a  iacoiincefol  with  the  other  wire,  [laitiog  down  Ihe  handle,  tuakcn 
ecnuiecliiin  belwrrn  a  itnd  A,  nnd  ihuH  makn  a  current.  By  nirsnuiog  the  wirta 
U  lb*  urvrnxl  biixlini;  *itt<vn  in  a ditl'rrent  way, the  making  contact  by  deprtiwing 
lb*  hudle  may  be  UMd  to  ibort-clrcuiL 

fm.  n. 


DitntAm  w*  tic  BiA-ltrntoiitt  Kty  Va 
A.AaBBkla«*niltteBtU«;  B,  to •koiiHdKelUar 

'  iniluctiun  i-ull,"  figs.  13  and  H,  the  wire  conticctinK  the  two  eleinctita 

Brrr  is  toivted  at  »oiuc  n*n  of  ita  course  into  a  cloac  •pira),  called  lllv 

primary  tvu.    Tbtia,  ia  Pig.  13.  iJiv  wire  t'".  connected  with  the  copprr  or  nrga- 

Itaptelc/'.ol  the  hatieiT.  £.  Joina  tbe  (iriniary  coil, /T.r..  aad  then  paiaec  on 

M  jT''.  ihrouicb  iht"\ty'"  F.  to  the  poatlive  Innci  plttf  i./-.  of  the  battery. 

Uref  tbu  primary  coil.  Irat  tjiiite  unconnected  with  it,  •lide*  aaotber  coil,  the 

■laa  f  II J  oh/,  'r. :  the  raA*  of  the  wire  foriDiiig  tbi«  coil,  y"  and  r",  are  con* 

tamni  «a  in  tlie  arrunKninent  illuMrated  in  tbe  li^ure  aa  y'  and  y,  ukI  aa  x'  and 

T.asfl  irnninato  in  elect r<'itea.     If  thme  clectr"deH  are  in  contact  or  connected 

^h  cosdacling  matf  rial,  the  citcuii  of  iho  MTondary  coil  i*  md  to  be  clowd ; 

etltvntlea  It  ia  open. 

In  an^  an  arrangetnctit  it  U  found  that  at  tbe  loomenl  when  ibe  primary  dr- 

'  nil  ;•  Mt.i  .1   1. 1 ,  wbeo  the  jirimnry  currrnt  la  "  made,"  a  aecoudary  "  induced  " 

cat :  t  an  exc«tilingly  bTief  |-crlod  of  liine,  net  up  in  tbe  aecoiidary  coll. 

Thi'-  ,18,  when,  by  raovine  the  '"key"  A' y"' aoa  »'"(  prcriouaJy  not  In 

ronDf^tKiM  with  e^cfa  other,  are  put  iiiin  cflniH-clioii,  and  the  primary  cnrremt  tbaa 

■adc.  at  that  iiMtjiiii  u  currrnt  appear*  in  the  nircH  y". j^".etc.,  liut  almoat  imm*- 

dlMely  dUappeHr*.   A  kiniilar  nliiiosi  liwiantiinroua  current  ia  alao  dereloped  when 

Iba  firliuary  current  ia  "  brulcen,"  but  not  till  then.    So  long  Be  tbe  prisiarv  cur- 

mt  flows  Willi  uniform  liitenuty.  no  eurrcBl  ia  induced  in  tuo  eeeoDdary  coil.     '' 


!<■  tte  mrdiii  rli(iiibp[«(aiMliiluglb«  BiiiWlt-iH.'  ,  ,-.:..iliMi.  "ni*  iiiniwlp  ■,  K)|i|«ttail  brtlw 
clamixil..  ohlcli  tinnif  f'l*  Ibrcnilof  tt>i:  flfmur/.  Uoannwtad  hf  nmnidf  ikc  ^hook  ■  uut  a 
iluaul  mlUiiiis  lever  I.  plocol  btloii  ih*  idqI<i  cluDbtr.  !>«  niims.  wlili  ■  ynnloa  ef  ilw*pla*l 
oolnms  K'tull  uurlml  bi  li,  ■■  iiluxl  on  ths  •(■rtm-lMil'lat ''>  i>i  omUiM  l•ll^  ihv  win*  t,  v.  !%• 
ntholear  thelotM'.rtror  tbe  elm  com  (t.  It  Wpt  slunM  wHIi  innlMKM,  and  ikc  clRlrado-bolikT 
kiacMiKnu!i*llluu*i>lernor  laaMriMil  UMIIna'[«tcr  mtjhi  pUrfil  ou  ti  irliiunii  «Anilii(  iBIa 
wnatt  wiui  tha  Dort*. 

S.  nenralTbic  QtliHler  bnrKti  Iheiaokied  p*p«"»  "Olob  Um  lisvot  wrttn. 

Clhillali-RaiiiMad'ikcTMimactdlOTibDtt-clniilllac-    TIicBtRB>>i>^l>arth«tliKtn9>l»-hoU*r 


TOK  MIK^'oMK^A  or  urAcLit  and  nervu. 


79 


curirni  apfican  lo  UM  ncoirniAry  vihi.  f  u  eacu  com  IBe  ear- 
f  diirntiiin,  gone  io  an  inxtont  almnat,  aiij  maf  therefon  be 
li<ji'k,"  Mil  liitlucUon  sbuvk  :  beine  cnlled  n  "  nuking  «hook," 
<y  ttir  inRtinn;,  and  ii  "  brtf^kking  slioiik.''  wbva  it  m  cjUM<d  b/ 


^ 


1*  oalj  «hfn  tti4>  pficDHtT  current  i«  «ilb«-  nude  or  brakea.  or  suddoolj^  rariu 
1«  ialMttltj-.  tliai  ■  currpQi  Apf««n  in  tint  nvninAntj  cM.     fu  each  com  tbe  ctir- 
nal  b  of  r»Tj  britff  durntin 
•p«k«n  of  M  "■  s)igi' 
wfcia  It  ta  c>ui«(l  by 

tb  bi««kin|-,  of  the  prjinnn  circuit.  Th«  diivclion  of  the  ctirrcat  in  the  making 
•bo«k  b  "priiiBed  la  tbai  of  ibe  primary  current ;  tliiH.  in  ihe  ttgute,  while  th« 
ptimMj  rurrrnl  flom  from  x"-'  to  y'",  the  jtidui.'i!ii  miilcin);  ihuck  lloin  from  y  lo 
'■  Tfc«  (tirrvBt  of  th«  bn-akio;  aknek,  <io  the  uthi!r  hand.  Saw*  in  the  ume 
liirvdlMi  a«  tliD  iiriiiiAry  current  frntn  ^  to  y.  and  l«  therefure  in  direction  ttaa 
re<«rw  <if  tb*  making  iJMck.  Compare  Pig.  14.  yrbere  orrangtweot  i<  ofaown  in 
a  iltefrmauBatlc  manner. 

Vu..  I*. 


IRlnlia  or  IK  iMIiirniiM  Ollt. 
•  fuMtn  pato,  «Bd  of  n^tflf  V  cteuHail ;  -  dwiUv*  pita.  Ml  of  imKUre  e)r<iHnt  of  IMis.-y :  K, 
Pa  am  Ki)wuwr»k«yi>r.  t.^t»>Ooc<l.eiirtwmM>wnbTlhH>wp*«rro«;«r  t.  MonuUtywU. 
nwwBi  itntn  bf  mkiihutd  am*. 


Tb*  cnrrmt  from 


aloof  tne 

— __  o»n  to  a  DM 

aad  tbrrefim  lending 


om  the  toUerj.  U|>an  lu  fint  i>ntrHnv«  int/i  the  pHmnry  i-oi|,  m  II 
h  twiti  -if  thot  coil,  t'ivm  rv*  in  tbe  neb^Uboring  tiriHU  uf  the 


10  o«l1  to  m  nKnuvaUrv  induc^l  ciirri^at  hnvinj;  m  liifMtmi  opposite  lo  iu  own, 
to'veftken  iUcir.    Il  UnotuuUI  lltU  "MlMntiucUou"  Una 


r 


■awnvi  Ikmoak  hIaAlnfl  temn  In  Hw  Boar  nf  lb*  mnlM  tttuntivr  wltb  lli*  wlrai  i',  y',  and 
aMMcand  IBtMkcT.MKiHi  i4ltirrM*.  ItiiWuinc  kfT»raklu<lxN)  (lie  oltMV.)'*.  catnip 
— WU^MTOBflu  r.  iif  llM  lixliii-|hKi<rnlt  1>     Tl>i>  •cunniltrT  dill  eau  la  nuOn  la  •lid*  ai> 
ia*«r  lb*  tntmufoM  f*  r..  aitb  vtiloli  an  r^nn(rii!<t  ilw  laawlra  i"  >nd  ir**;  ^"b 
dMcOf  wlOionfolc— (cvliuuaer.  lliBappn-pntcFp  ctf  llw  ballerrX,' r*'l*e>rilt9l  lo 
■■■a.  «.of  lhi>  Mfmii  tvy  /*,  and  U  roiiUuuad  u  yi*  fium  wunliv  UniUna  Nnw,  t|  of 
tha  t<V  M  u*  its*  |i>la  I  p.  lit  iha  taitnT' 

•4«TilMiia  h-  lir  Bfnntnl.  aa^  the  hallCTr  I'hariwl :  em  ilapmiliia  Iha  haadle  a*,  of 
tar  /',  a  ninmi  alll  Iv  maJg  In  ItH  |i(lau7  will  jir  (  ,  paidiut  ftum  «.  p  Uironfft  r"  to 
^, «.  ■adtaMoaUuiHuby"  !■>«,  (i-ii>ia  lu  ti. and  lu  Ihivacli  »■•  lu  )  v  iinnmoTlns  the  fiiiaar 
taM  **  kaiHlla  uf  r.  a  Minnv  tliraita  ■!>  Um  baalk.  and  Hip  iinuiBrv  dnnii  li  In  OMMsfQawa 
IfkKiikn 

ih»l  llv  rAMM«y  enrKoi  l*  cHkw  hmiI*  ■■hmaMi.aalnducail  BUnMil  la  iDrike 
■wiiuyil  in  111"  Mnwutwy  wM  «.  f.    II  iin  onafclf  A  hi  Mb  Pa  BitoBiTawJ^  hwt* 


^ 


rn  la  iWlliirk  Hiu  laUwlnimi,  llin  «!•■  c*.  r*.  >.  iba  iun«  batwavn  lli«al«DUDd«i 
a*(tka  ali^*,  ■'.  ir*,  IWai  Uit«i>u|ilrtf<*om<lary  dicult.  ami  (h«  nnrra  ooanqooiitlr  *iprncii«ia 
.  M  Imtlnv  tudatt)<Mi«boek  whcm-ni  ilis  ivlmarr  enmal  I*  maile  or  bNttm  If  Ika 
td  ilv  Im  IM»-lti7»aMl  ka;  >•  (aiit  il-iA.  u  In  Ilia  dMIcd  tlD«  Via  ik«  t^m.  tlw 
Hf  Ibr  rnivkarU  n>U(l>l  cionraml  nllh  ikaiuf  IM  ncnv  anrtu'  I  ho  ali«*  sohig  n»in 
ta*  h>r  *»  Uw  iMnc.  Mat  Uh)  abulc  accondnir  (IDdocaij  camni  \mma  iniB  ^  lii  v'  (M  Ouui  y*  lo 
4^ aiMB  tka rus'l*'.  and  |«ac*l«allr  b«d*  |«iBi  tnioUi«  n«rr*.  Tba  nom,  Wns  lk«a  '■•bort- 
.'  u  Ml  adbctad  lif  aiij  cbaafM  to  iW  ciinaiil. 

UUilmlol  lacnl/ tnUhHUaleUw  (uupral  inotk«ila(  KiuljtOS  NiiwUlarooiilnioUun  : 
NN  •><  1.1  !■  MipfaadUiBiih* 'Mali*  bonvtmiar*  ualir«nalIradapie<l,«.iuiIaBl.ili«lisM  toall 


80 


THE    COSTBACTILE    TISSUES. 


8 used  off  that  the  current  id  the  primary  coil  is  eatHbliBbed  in  its  Aiil  atrengih. 
wing  to  tbiB  delay  in  the  full  eBtublishment  of  the  current  in  the  primarj  coil, 
the  induced  current  in  the  aecondary  coil  ib  developed  more  bIowIv  than  it  would 
be  were  no  such  "  self-induction  "  present.  On  the  other  hand,  when  the  current 
from  ihe  batter;  is  "broken"  or  "abut  off''  from  the  primary  coi),  no  such  delay 
1b  ofiered  to  its  disappearance,  and  consequently  the  induced  current  in  the  second- 
ary coil  is  developed  with  unimpeded  rapidity.  We  shall  see  later  on  that  a 
rapidly  developed  current  is  more  effective  as  a  stimulus  than  is  a  more  slowly 
developed  current.  Hence  the  making  shock,  where  rapidity  of  production  is 
interfered  with  by  the  self-induction  of  the  primary  coil,  is  less  effective  aa  a 
stimulus  than  the  breaking  shock  whose  development  is  not  thus  interfered  with. 
The  strength  of  the  induced  current  depends,  on  the  one  hand,  on  the  strength 
of  the  current  passing  through  the  primary  coil — that  is,  on  the  strength  of  the 
battery.  It  also  depends  on  the  relative  position  of  the  two  coils.  Thus  a  second- 
ary coil  ia  brought  nearer  and  nearer  to  the  primary  coil  and  made  to  overlap  it 
more  and  more ;  the  induced  current  becomes  stronger  and  stronger,  though  the 
current  from  tbe  battery  remains  the  same.  With  an  ordinary  battery,  toe  sec- 
ondary coil  may  be  pushed  to  some  distance  away  from  the  primary  coil,  and  yet 
shocks  sufficient  to  stimulate  a  muscle  wilt  be  obtained.  For  this  puipoee,  how- 
ever, the  two  coils  should  be  in  the  same  line ;  when  the  secondary  coil  is  placed 
crosswise,  at  right  angles  to  the  primary,  no  induced  current  is  developed,  and  at 
intermediate  angles  the  induced  current  has  intermediate  strengths. 

Fill.  IS, 


TlTE  MAliNETIC  iNTEKBI  ITOB. 


When  the  primary  current  is  repeatedly  and  rapidly  made  and  broken,  the 
secondary  current  being  developed  with  each  make  and  with  each  break,  a  rapidly 
recurring  series  of  alternating  currents  is  developed  in  the  secondary  coil  aod 
passed  through  its  electrodes.  We  shall  frequently  speak  of  this  aa  the  in/errupted 
induction  current,  or  more  briefly  the  interrupted  current ;  it  is  eometimes  spoken 
of  as  the  faratiic  current,  and  the  application  of  it  to  any  tissue  is  spoken  of  aa 
faradiznUon. 

Such  a  repeated  breaking  and  mafiing  of  tbe  primary  current  may  be  effected 
in  many  various  ways.  In  the  instruments  commonly  used  for  the  purjiose,  the 
primary  current  is  made  and  broken  by  means  of  a  vibrating  steel  slip  working 
against  a  ningnet;  hence  the  instrument  is  called  a  magnetic  interruptor.     See 

%■  '■'"'■ 
The  two  wires  x  and  y  from  the  battery  are  connected  with  the  two  brass  pillows 

a  and  d  by  means  of  screws.    Directly  contact  is  thus  made  the  current,  indicated 

in  the  figure  by  the  CAi'i;*  interrupted  line,  passes  in  the  direction  of  the  arrows. 


THB    PUKNOMENA   OP    ML'8CI.B   AN'D   KKRVK. 


81 


mp  tito  pillar  a.  ftlang  the  tt(«1  •priiig  h.  u  Ut  m  t]i«  iwtvw  e,  tbe  pgiot  of  whicb, 
um^  with  plUlnuRi.  I*  in  conUct  witli  ■  ooiall  pluiuuaa  plxte  on  4.  Tlie  cnr- 
n«l  pMMM  frum  6  tbrouxh  e  uid  «  connectiaf  wire  into  tbe  prlmuy  coil  p.  I'pou 
te  MUrinf  ioui  ibv  iirimorT  coil,  ui  inilucM  (laaUnfr)  current  U  for  tlic  inaUxii 
Jwleped  in  tbe  wcondarr  coil  (not  ■bown  iii  tb*  fignn).  ('rom  the  iiriiusrT 
Mil  p  UW  cuncni  pMsee,  bv  a  connecting  wire,  throueb  the  double  tpiral  m,  iui<l, 
dU  Kotblng  happen.  wmiM  ciiiiinni;  lo  p«»  frnm  m  ttf  m  coontctlng  wire  to  the 
plUsT  J,  and  wa  by  the  wire  y  to  the  battery.  Tie  whole  of  Ihb  eourw  b  imll- 
anted  bj  tbe  thick  inlrrruplcil  line  with  its  arrows. 


Pd^  W. 


'V 


:c. 


■4 


/?5 


Tki  MaowRW  bTiaatmia  with  IbuniMR  AuuimuttyT  nm  KaciuoM 
twi  UiKi  um  Unuk  inn'u. 

As  tbfl  rurreot.  h«wevrr.  psnm  ibrouKfa  the  xpirsU  m,  the  iron  cores  of  tli««e 
rw  Mttde  nugnetic  TImjt  In  comMjoenoe  draw  do«m  Uh  iron  iMr  e,  fixed  at  the 
cad  of  Ihv  ijiring  b,  the  Oeilbilltj  of  the  aptiog  allowiu  ibi*.  But  wbca  i  i* 
dnn  down,  the  platinum  plate  on  the  iipp«r  lurTace  ot  fr  b  abo  drawn  awar 
ft«B  tlMactew  <-,  and  thu«  the  current  b  "uoken"  at  6.  (ScoBttJlMalhe  screw/' 
b  «>  amuigwl  that  wlien  c  a  drawn  down  a  plnliiiitin  tilnte  on  (he  tmiirr  lurfnoo  of 
i  ia  beaa(bt  inta  oooiacc  with  the  platiiium-ariniii  [loiiii  of  the  ikt^w/.  Tbe  cur* 
real  ibeti  riM-nt  frntn  A  not  to  e  bat  to/,  itiiil  wt  down  tbe  pillar  i^,  iii  tbe  directton 
kndicaln)  by  the  Min  iiit^rrnpted  Hue,  aixi  out  to  the  batlerir  by  the  win-  <r,  and 
tt  thot  rni  r.if  from  thi-  primary  coil.  But  ihia  srrwifemetit  i"  unnccewiify)  At 
tk'  I  iDt  llic  current  in  tbim  broken  and  •»  cat  otT  rmn  ihe  priiuiirr  coil, 

ae  '  iirenkini;)  current  is  fur  the  mument  developed  In  the  ««coiidaxy  coil. 

Ital  Uui  burteut  b  cut  olT  noi  only  from  Ihe  primary  oo|].  but  abo  ftom  the  aplnb 
■■ ;  In  eoiHoinetice  ibeir  core*  cease  lo  Im  macneiized,  the  bu  t  CMiMi  la  be 
•nncUd  bf  iheoB.  aod  tbe  aprinii/i,  br  Tirtueuf  it*  etaiticily.  rwunMS  Ita  former 
Milllo*  111  oonbict  wiib  the  anvn  r.  'i'htt  rrlurn  of  [he  ■prini;.  howerer,  rcAitah- 
KAm  the  carrenl  In  the  primary  «>il  and  in  tlie  npimU.  unit  the  H>rliit  b  drawn 
ihiii'B,  to  be  reltmid  onoe  more  in  ilie  Mine  mnnner  u  Wr'-re.  Tbos  M  long  m 
llw  carrtnt  b  fwMng  along  ^  ibe  contact  of  t>  wiib  r  is  sltrrnmely  being  made 
■■d  bnkM,  MM  the  current  b  comlantly  paasiuK  into  and  beinx  ■hui  '>ir  frum />, 
llw  pednds  of  alternation  being  determined  by  Ibe  Mriodi  of  vibration  of  the 
if*{a(  A.  With  each  pa«^e  oiUie  curreai  iuU>,  or  withdrawal  tr«ta  the  primary 
<mI.  an  lixlueexl  (msking  aad.  respectively,  breaking)  carrent  is  developed  In  a 
•eeowlar;  coil. 

As  thtH  need,  each  "  making  iJiock."  a*  esplmned  abora,  b  less  powerftil  than 
iW  OKrvapUBdlag  "  brealcing  »hock ;"  and,  indeed.  It  sometimes  happenn  that 

« 


TKB  COXTRACTItE  TISBCBS. 


iiutMiI  of  «ac]i  mtke,  u  well  u  eftcb  kieiik,  >eliii(  u  ■  •timnliu,  eiTiag  ri*e  to  ■ 
conlractloti,  the  "break*"  onlf  are  eiFi^ctivc,  the  Hreral  "  luakea'  gimg  riw  to 
BO  ronlmclions. 

But  what  in  knoirn  an  HelinholD:'ii  armngumeDt.  Fig.  IC,  how«ver,  the  makiiig 
•od  breaking  thocka  amy  be  equalixed.  Kor  Lliis  purpoM  the  ktcw  c  u  niiscil  out 
of  reach  of  Uie  «xcuntoiia  of  Uie  S|iria{;  t,  &111]  n  iiiuilcraielv  tblck  wire  v.  ulfering 
A  certain  amounl  only  of  rMUtance,  is  interposed  between  lue  Dj)per  biadine  acrvir 
a'  on  tb«  pilUr  <i,  and  the  binding  kkk  q'  lending  to  the  primary  coil.  L'ndef 
time  arrariKcmooIii  ibe  current  froin  tbo  battery  pussM  thniugfaa'.aloii^lhi?  iiitvr- 
pofted  wire  to  <•',  through  the  primary  coil  uud  tljus  as  before  to  m.  As  before  by 
tlie  ma^uellzation  ofm.r  in  drawn  donn  and  6  brought  iii  ccictaci  with/.  Aa  the 
rwult  «■  lhi«  cnntjiet,  the  currpnl  from  the  bnilery  can  now  im*«  by  m,/.  mid  4 

Sbown  by  Ibc  thin  interruptt^d  line]  buck  to  ilie  buttery;  but  not  ihr  whulp  nf 
e  current,  rtunii^  uf  it  can  «iill  piuH  nlong  the  wire  w  to  the  primury  coil,  the  rela- 
tive amount  being  deiennined  by  the  relative  resistAnce  ulfered  by  the  two  cuutM*. 
Hence  at  cnch  ■ncceuivi'  mnsnotiiution  ofrn.  the  curr^'nl  in  ibe  jirimary  coil  doea 
not  entirely  diHiippenr  when  t  i*  bruuirht  in  cnnlnctwith/;  it  is  only  »o  far  dimin- 
tfhei]  Ihul  'II  ceuses  lo  ullrftt-l  c,  and  hence  by  the  rcletme  of  4  from  /  tile  whole 
vurrrni  uiice  mure  jiasHM  alone  to.  Since,  at  what  eorreHponds  to  Oie  "  break  " 
the  cuneot  in  the  primnry  coil  i«  diminitihod  only,  not  abaolutely  done  away  with, 
aelf-induclion  makr«  itn  appearance  at  the  "  brejik  "  oc  well  a»  at  the  "loake;" 
thoa  tbe  "breaking"  and  "nukiDg''  inducvd  currentu  or  shocks  in  theaocondary 
coil  are  ec|uulix«i).  They  are  both  reduced  lu  the  lower  efficiency  of  the  "  mak- 
ing" aliock  lu  the  old  armiigeraent ;  hence  to  produce  the  same  streaglfa  of  «timu- 
liu  wilfa  thia  arrHngcmenl  a  stronger  curreni  mniit  be  nrplicd  or  the  *«coudaTy 
«oil  poshed  over  the  primary  coil  to  a  greater  extent  than  with  ibe  olJicf  arraDg«> 
men  I. 


The  ilienomcna  oj  a  Simple  Afutcular  Oontractum. 


4 


S  46.  If  the  far  end  ot  the  nerre  of  a  muscle-nerve  urepnnitioii.  Ftp.  1 1 
and  IS.  be  Inid  on  olectrodeB  cootiect^d  with  ilic  K-cnntlnry  coil  of  nit  indue- 
tion-mAcbine,  the  paxsage  of  a  nngle  Induction  (hock,  which  may  he  taken 
at  a  cnnvenient  form  of  an  almotit  momentary  stimnliii,  will  produce  110 
visible  change  in  tlio  nerve,  but  tbe  iuu«clo  will  give  a  twitch,  a  «hort.  sharp 
contraction,  1'.  e.,  will  for  an  iDilanl  ■horten  itaolf,  boooming  thicker  tm 
while,  and  then  return  to  ite  previous  condition.  If  one  end  nf  llie  muscle 
be  nitaohed  to  a  Ic^Tr,  while  the  other  \t  lixcd,  the  lever  will  by  its  move- 
ments indicate  the  extent  and  duration  of  (he  shortening.  If  the  point  of 
ilie  tever  be  brought  to  bear  on  some  rapidly  travelliiig  surfnoo.  on  which  it 
leaves  a  tuark  1^ being  for  this  purpose  nrmod  witli  a  ucn  and  ink  if  the  sur- 
(kce  lie  plain  paper,  or  with  u  bristle  or  finely  pointed  piece  of  platinum  foil 
if  tbe  surlaoe  be  smoked  gla^  or  paiwr^  so  long  as  tbe  muscle  remains  ai 
rest  tbe  lever  will  describe  an  even  line,  which  we  may  call  the  base  lioe. 
I^  liowcver,  the  mascle  ihorleus  the  lever  will  riae  above  the  base  line  and 
thus  d«tcrlbe  some  sort  of  curve  above  the  base  Hue.  Now  it  is  found  tliat 
when  B  single  inductiou-Hhoclc  is  sent  tliruugh  tlie  nerve  tbe  twitch  whidi  the 
mtucle  gives  causea  tbe  lever  to  desoribe  some  such  cur%'e  oa  that  shown  in 
Fig.  17;  the  levrr(anrra  brief  inltrval  immediately  auooeed in ^  Ihe  oi>cu!ng 
or  diutiiug  the  key,  of  which  wi;  shall  apeak  presently)  rises  at  lirvt  rapidly 
but  nflerwnnl  mnn.-  niowly,  stiowinu;  tlmt  llit-  um»ele  is  correspond ingly 
rbortcninjf ;  then  ceaum  to  rise,  showing  llinl  tin-  muncile  i*  ceasing  tii  grow 
shorter:  Uien  dtvccndK,  ehnwing  that  the  nuiticlc  in  liMiglhening  again,  and 
finally,  sooner  or  Inter,  renches  iiiid  join*  tin-  baw;  line,  vhowing  that  the 
muscie  utter  the  shortening  biu  regained!  its  prt-vioit*  nuturat  growlJi.  8uch 
a  curve  deecribcil  by  a  muscle  during  a  hvilch  or  simple  iDiiScular  contrao- 
tiuu,  caused  by  a  single  iiiduclion -shock  or  by  any  other  stimulus  productng 


rne  phknohe.va  or  ml'sclr  axo  nebvb. 


88 


•a*  «Atf,i>ctIlMl  I  curvAof  H  iqni|il«  muiwdliu-  oontraoioii,  or,  mora 
'■hvtl*.  •  "miuoltt-ciifvc."  U  b  nlimiu  thnt  th«  rsact  form  of  (be  ctirro 
dnvi^ml  Uy  UirM'uMl  roolrncliaiu  of  il  miiiicle  will  <lpp''iiil  i>ii  tlif  rft]>ic)itv 
«kb  which  Oir  rpcvmling  surr'uw  i*  Irnvcllioji.  Thu»if  ihi-  ^iirfliN  be  (r«v«J. 
Bm  cJtiwIj  ibe  ii(>-ir<>ki'  i^'im-^jHitiiliiig  to  ilic  tJiitrU'tiiii^  will  Iw  vert'  abrupt 
mad  tbv  ((u«i D-«ln>kv  also  vvrv  KUtji.  l<^  in  Fig.  1)1,  winch  u  n  curve  froia  ft 


•.IT. 


Fus-li 


VTw 


..»:.. 


II I  I  <>H  iirr  ri«iTiiooriHii>  i>r  mi  Pkm.    Tlili  cum.  likv  «ll  mnndlnc  oiis, 

iW  -ti'4,  i(  lo  iB  mtd  frn«  kftio  lUIit— ilMiltisnjr.  whilpihe  lentimd  i«iiln(- 

•  •taitiii.>r)  iiic  MrartiBf  (OfTHv  oM  tmiolUns  ttiHn  ilEbltD  InlL 

mtm  Uir  BoiiMti  at  ohttli  ibr  brdwiion-tluH'lt  i*  xuii  Idu>  ilu>  nnr*.  b  Uh  niiiiiiiiiiiimiiwii. 

lf»i>au  uKl  it  Ik*  rloar  nf  iIh  OMUnffUin. 

lh*«aKl»«iirvrl>iliiic>inr']n<iub]fiituDlBc.n)[knuikliwloa<IoUtikVibniUaniaM«oad. 

vplrtir  fune  nrfcmiiuiic  (benKm  ouv  biiiulmlili  of  ■  bomuL 


fencl>ralill9  iii(iarl«  of  n  friw,  tnkru  vrilh  a  Hlowlr  inuvirifr  drum.  tli« 
fl^lbrk  b«iii^  tbe  tumio  ft«  ibn)  iind  in  Fig.  17 ;  inilfcil,  njih  ii  vrrv'  t\ow 
wvimcnt,  ihf  twti  mtty  be  hanlly  •cpiimble  Ham  each  oUht.  Oh  tbr  olhvr 
IhumI.  if  the  •urtiLcc  irnrH  verv  rairidly  th«  curve  mfty  Iw  iinnii»diit«lir  long 
tlrmwn  uat,  *n  in  Fig.  I!',  whicli  is  »  curvo  from  a  giutrocncmiuH  muscle  of 
a  frtifi.  taketi  with  a  very  rapitlly  moving  pendulum  monvgrnph,  the  tuiiiiiff- 
(oA  mftrking  Blwtit  t'lOO  vibrations  a  feeond.  On  exnniiiiHtioD,  however,  it 
will  ho  IbuQU  that  both  these  extreme  curves  are  liindaiiicii tally  the  same  aft 
lb*  nadium  one,  wbea  tooouat  it  taken  of  th«  diSnreut  rapidities  of  the 
ii»T«lluH  surface  in  ibe  sereral  caoM. 

Ib  oftfer  to  make  ihc  "  mu*cle  curve  *'  complete,  il  is  nc>oe»arr  to  mark 
Ml  ilw  rccordii)][  surface  the  exiiet  time  at  itbieb  the  inductian-sbock  ia  seut 
laut  ibt  aerve,  and  also  to  note  the  apeetl  at  whieh  the  recording  etifface  h 
umntOat. 

Ib  th*  pendulum  mvograph  the  rate  of  movenieut  can  be  calcuUiMl  from 
iK*  ttogtfa  of  the  poiiilulum:  but  even  io  this  il  it  eouveniem,  and  >a  the 
ea»  uf  the  aprinfc  MTu^'^ph  and  rerolring  cylinder  is  neoesaarr.  to  roeaturc 
tba  nklf  of  mm-enx-ni  direvilv  by  means  of  a  vibrating  tuniug-fork,  or  of 
wiB«  body  rihiHling  re^iilarfy.  IndetNl  it  ia  beet  to  make  such  a  dirvct 
BManrMBMit  with  eai'h  curve  thai  l-  btkini. 

A  taniav-fork,  as  i*  kuown,  vibrate*  ao  many  umea  a  Mcond  according  to 
ila  f>Hdb.  if  a  inning  fork,  arrmil  with  a  light  murker  on  one  uf  iu  prungs ' 
■M  ribrating  mv  l""  a  tccood — r.  r.,  <is«>'uliiig  a  duuble  vibnilion,  muring 
ferwmnl  and  liai-kwan).  1**0  timet  a  second —h«  brought  while  vibrating  Iu 
■ak'  a  tn^-iRL'  "B  the  recunling  nirftee  immcdiaiely  Iwlow  the  lever  l>c)ong- 
iap  '  '.  w<*  (3in  um:  the  cnrvL-  or  ralhiir  t-urv<v  di3'i'ril>o<I  by  the 

toD'-  '  Mim  thv  dunition  of  any  pari  nr  of  tlie  wholr  of  the  miu- 

clt>e«irv«.  It  is  i-eMnnlial  thai  nl  *(nrliug  ihr  [Hiint  of  llie  miirkcr  of  tba 
lastaf-fork  th»u)d  l>c  trxnelly  umli-nii-iilh  ibi'  marker  of  ihr  Ivvur,  ut  rather, 
■nrr  the  fiini  <>f  (he  lever  w  ii  move*  uii  and  ilnwn  dtwcrilxa  not  a  Mraieht 


but  an  arr  'if  a  circle  uf  which  iVt  fitlcruiii  i»  the  cvOlre  and  ilself  i,fn>m 


TUB   COJfTRACTItK  TtSSnS. 


lli«  fiilcTimi  to  iWtipof  llie  iiiai'kcri  the  raHiu»,  that  llie  jmiDt  of  the  luarker 
oftho  tuntng-rurk  Hhoiitd  be  exactly  mi  the  arc  described  hy  the  marker  nflbv 
lever,  either  above  or  below  it.  ai  may  jirove  mnu 
I"'"*  con  veil  ieut.     If,   iheD.  at   MartioK   the  lAiDiiiR-fork 

marker  be  thus  uii  the  arc  of  the  lever  marker,  «iti) 
we  tiuie  tiu  the  curve  of  the  tuning-fork  the  place 
ithere  llie  arc  of  the  lever  cula  it  at  the  Iw^iiuinv 
and  at  the  mil  of  the  miiscic- curve,  as  at  Pij;.  1', 
we  call  cdiiiil  the  luimlaTof  I'ihralionn  of  the  luiiiDg- 
fi)rk  which  have  taken  place  belnviMi  the  two  niarkik 
aivl  »i>  niKHMiaiii  the  whole  timu  nf  the  inuAcle  ctirvc; 
if,  for  inotanct-,  there  have  I>c«-d  10  ilouhle  vibration*. 
<!ac'h  occupying  ,  J^  »eci>iiil,  the  whi>lc  curve  hn»  takes 
,'n  so'oiti)  to  i»nl(e.  In  the  Miuie  nny  wo  Can  uivKMire 
the  dtirntion  of  ilie  ri«;  of  tlie  curw  or  of  ibr  jall,  or 
of  any  part  of  it. 

Though  the  tuning-fork  may,  br  »niply  rtriking 
it,  be  set  going  long  enough  for  the  purpoam  of  an 
otwervntion,  it  is  convenient  to  ke«p  it  going  by  weans 
of  an  electric  current  and  a  magnet,  ve^-  much  at 
the  spring  in  the  magnetic  uiterruptor  (Fig-  15)  is 
kept  going. 

It  is  not  ueceteary  lo  uee  an  actual  tuning-fork; 
any  rod.  armed  with  a  murker,  which  can  W  made  to 
vibrate  regularly,  and  whoi^e  time  of  vibration  ii 
known,  may  lie  used  for  the  purjxwe;  lliua  a  reetl, 
made  to  vibrate  by  a  blast  of  air,  is  tometiioee  eui- 
ploveil. 

Thv  exact  moment  at  wliich  the  induetioti'i>hock  ii 
(brown  into  the  nerve  may  be  rvcoriled  ou  the  niuicle- 
curve  by  menns  of  a  "  NgnnI,"  which  may  be  Mjiptiiil 
in  varioMi'  ways, 

A  light  steel  lever  anned  with  n  marker  U  arrancod 
ovM  ■  Kiuiill  coil  by  mean*  of  a  lifibt  ipriutt  in  Mich  a 
way  that  when  the  euil  by  the  iiiuwngc  of  a  current 
\  through  it  becoum  n  iniignet  it  palls  ibe  lever  ilown  lo 
ilBcll-  on  Ibet-iinenl  being  lirolcnn.nnil  the  mnunetizaliuo 
of  the  coil  ceiHinK,  ibc  lever  by  help  of  the  *i>rioic  Hie* 
lip.  The  marker  of  ouch  a  lever  in  pliiced  iiniuediiti-ty 
under— i.r.,  at  some  point  on  the  arc  de«cril>ed  by— ibe 
uinrker  of  the  intisele  (or  other)  lever.  Hence  by  making 
a  current  In  ilie  coil  and  pulling  tbn  li^al  lever  down. 
nr  by  bicinking  iin  iilrcndr  exi:itii>|r  current,  and  lettinj; 
the  iiidniil  lever  By  up,  we  can  uiake  at  pleaHure  a  mniK 
eorreiponding  to  any  part  we  please  of  the  miuclclor 
other)  eari'e. 

If,  in  order  to  ningnetir«  the  roil  of  the  •ignal,  we  tM«, 
an  we  may  dn,  the  priinury  current  which  Reuerale*  the 
indurtioii-nbock.  the  breaking  or  making  or  the  orimaij 
cnrienl.  whidiever  we  u»ii  lo  proiluce  the  inouctino- 
■bu<^k,  will  make  the  Mgnal  lever  Hy  up  or  come  down. 
Bvace  we  ibnll  huTr  mi  ibe  recording  nirface,  under  tli« 
niuarlr,  a  mark  indimiiug  the  exact  mometii  at  wliidi 
tlip  pritiinry  current  was  broken  or  made.  Now  the  <iai« 
taken  up  by  the  generation  of  the  induced  current  and  ita 
M0Mge  into  Ibe  nerve  betneen  the  clei'triidti'  i*  wi  inliniie*imally  >maU.  thai  w« 
nay,  without  appreciable  error,  take  the  mouient  of  tlie  breaking  or  making  of 


THE  COSTKArriLK  TlgSVEi*. 


tbe  primary  curr«DC  a«  the  monieiit  of  ibe  eDtr)in(«nrili«  InOitclioii-ehoci:  (iitutke 
nerve.  Thiu  wc  csn  mnrk  Wlow  ilic>  niaKl«-curT«,  or  hy  dcKribin);  ih«  «rc  of 
tlko  niMcIo  lovpf,  'in  ilir  mumOc  rurrp  it«iHf.  clir  exact  niMiieat  at  nliicfa  the 
inducUon-sliock  lalls  into  Ibc  nervv  between  tbe  elrclrodtn,  na  U  dofic  at  a  in 
RgB.  17.  18. 19. 

In  the  peoduluni  mvogmph  a  «e|>arnte  iiii^nal  is  not  needed.  If.  harinK  placed 
the  mufcle  tever  in  the  pn*itinn  in  iThi<!h  w«i  intvnd  to  make  it  rm«ril.  we  allow 
tbpglaM  pinto  lo  descend  until  Ilie  tontli  n'  jwit  toi>chei  the  nxl  r(ta  ihai  the  rod 
ia  juiit  iiltuut  lo  be  knocked  down,  uud  *o  Ureuic  tbe  primary  circuii)  and  oiake  on 
tbe  baite  line,  wblch  is  meannliile  being  dettcribed  hv  the  lever  marker,  a  mark  to 
iitdlcnto  irheie  the  point  of  tbe  marker  u  under  iliv*c  drcunutancn,  and  then 
brinf;  hnck  the  plate  to  ilK  projirr  pwilion,  ibr  mark  wbidi  we  have  made  will 
mark  th«  muuieut  nf  tbe  breaking  of  tbe  primari'  circuit,  aud  no  of  tbe  entraiKe 
of  Um  ill  duo  I  ion -9  book  into  the  nerve.  For  il  is  juM  wben.  ati  tbe  iilaM'  plaie 
airings  down,  tbe  murker  of  the  l«Ter  comen  to  the  mark  nhicb  we  bare  made 
that  the  rod  f  i>  knocked  hark  and  ihe  primary  current  b  broken. 

A  "aixual  "  like  ibc  above,  in  an  impr»ved  form  knuwn  oi  D«iipn^t):'s,  may  be 
lacd  aUo  Ui  record  liine,  and  ibua  ibc  awkwatdneM  of  bringing  a  larve  tuning- 
fofk  up  to  the  recording  aurracc  obTiaied.  For  this  pnrnote  the  signal  i«  intro- 
duced into  fl  circuit  the  current  of  nblcb  ia  coulinunlly  ticing  made  and  broken 
by  a  tuning-folk  I  t'ig.  21  ].  Tbe  tuninu-fbrk  once  net  ribmlini!  continues  to  moke 
and  break  ibe  cutreiil  at  e«cb  of  its  vibrations,  and  ai  Hinted  above  ia  kept  vibrai- 
ing  by  the  current.  Bui  each  make  or  breiik  cHuwd  by  the  ttininic-fork  alTecia 
■lao  tbe  email  roll  of  ibe  nlgDal.  causing  the  Icvrr  of  ihaaignnl  u>  fall  down  or  fly 
up.  Tliuii  the  Bignnl  dcMfibea  vibration  curves  nyncbrorioua  with  lho>c  of  the 
tuiiiD{>fu(k  driving  it.  TbeaiKnal  may  similarly  be  worked  by  ineaiiiof  vibrating 
^^Bta  other  than  a  tuniog-fDrk. 

Varioutt  recording  aurfacea  may  h«  u»ed.  The  form  moat  generally  iisefbl  ia  a 
cylinder  covered  irith  imoked  paper  and  made  to  revolve  by  clockwork  or  otbcr- 
wife:  auch  a  cylinder  driven  by  clockwork  id  aliown  in  t'ig.  IS,  B.  ^  naiiR  > 
eyiiiiderof  tar^-erailiua  wlthade<|uaiegeaT.  a  high  apeetl  forliiaumce,  in  aaeoood. 
eaa  be  obiaincd.  In  the  ^Ttn;;  mi/r/i/raph  a  amolced  glaaa  plate  la  thrust  npidly 
fbrward  aloog  a  groove  by  means  of  a  spring  suddenly  ttirown  into  action.    In  the 

t\endiilum  m-zoffrufih.  Fig.  20.  a  amoked  ^ln«>  plate  atlHched  lo  tb«  lower  end  of  a 
ong  fmine  avinitioi:  likr  a  pendulum,  ia  auddrniy  let  go  at  a  certain  height,  and 
so  swiuga  rapidtv  through  an  am  of  a  circle.  The  diuidrautxge  tit  tbe  last  two 
methods  ia  that  the  surface  travels  nt  a  contiDually  ^hangiug  rate,  whereas,  in  the 
nvolving  cylinder,  cnreful  con^iriiction  and  ndjuslment  niill  secure  a  very  uniform 
rate. 

§  46.  Htivine  thus  obtained  a  time  record,  and  an  indication  ol'tlie  exact 
tuoincnt  at  which  Ihe  induction -shock  talis  into  the  nerv-e,  we  may  for  preeent 
pur[KMe)t  coiiiudcr  tbe  muscle-curve  complete.  The  study  of  such  a  cur\-«, 
nafor  inslauce  that  ahowu  in  Pig.  17,  taken  from  ihegnUrocnctDiusof  a  fW)g. 
teaches  u»  thu  follivwinK  facts: 

1.  Thrit  nllhgii^h  the  piiaau^e  of  the  indueeil  current  from  oleciro<lc  U) 
cloclrode  »  |inictx«illy  iuKtantuncotia.  iUcflcct,  mwuiiirwl  from  I  he  oil  trance 
of  the  shock  into  thi-  nerve  to  the  reluro  of  the  muscle  lo  it«  nntnrnl  length 
after  the  sharteniiig,  takn  no  appreciable  time.     In  the  figure,  the  whole 

llbeldta  that  pvTIlun  lir  Ihv  lonlhu'OBlotiliutan  ihr  micIi  v.  In  Ibetonnaof  llaralna  UielnMh 
a*  ooinlfic  tn  coniBin  wlihihct^oJeetlnaitMlrtiilf,  kii<>ckiliui>unualdolmoUie|>odtlanln4loawl 
bytb«  i1«ll*<l  lliiv  r'.  Tbe  nid  rii  In  «j«trti]  fuiiUnulljr  villi  llii>  wlrv  i  of  tbe  |frtuiaiy  coll  of  Ml 
luductlon-iiiachliiiF  Tlii'  (rnrw  rf  la  ■linllarly  til  vli<ctrld  MntlniilCT  "^^  11"  o^rv  yof  tlMMBC  |>rl> 
fuary  ooU,  Tlia  fora^v  tf  aiiJ  Ibc  itrt  i' '  rv  armi-d  wjili  flaUnum  ai  ihv  ]vilu<a  la  trhlcti  tlw7  an  In 
eeutuct.  and  bmli  ai«  limiUlnl  liy  iiil9Ui>  ii{  lliv  cbniilii-  lilwk  t  X>  1iiii(  a>  '  anil  •!  am  In  rontacl 
UiDClrinill  oT  llw  iitliimtrCDtl  U>  Hhlch  i  aii<l  u  buloiiK  I*  cl-awl.  W  lien  In  lu  naUu  (be  iDuihtr* 
kuockiraua;  trom  it.  ai  tbat  liuTanI  tb«  rtmill  in  broken,  aiid  a  "lumkiue"  ibuek  li  agiil  lti|ea|li 
tin  tliclniili'i  uiiiiivL'ii>a  Willi  Uio  iiBCOiu1ar7  Mil  nf  (tin  nuirlilni>,  aiul  iti  tlimiigb  lb*  atrn.  Ibe 
lover  r.  lb*  Fill)  only  ^•i  urlilrli  i<thown  tn  tbe  dfnn-,  !•  brouKhi  lo  btarou  (bcalaa  plaie.  and  wbni 
Bimtileachbaaimliihi  tlni.-,  or  inoTseUiOllr  an  on.'  of  a  Plrelc  or  larito  ndllK  Tbo  luallia-Airk/. 
Iheend«nUl]":>Illiclvn>tliDla<>ri>blcbat«abnwnlnlb*ngun|dat«dltHM0lB(«lyMOlr  Dntlncr. 
Sttvea  to  niark  tbe  Ilia*, 


TUE    I'llKNOMKNA    of    UUSCI.K    AKD    XKBVK. 


87 


mrr*  tnn  a  lad  takca  up  alxiut  tl>e  tumw  time  u elcron  iluuliti*  vibrntiou 
of  ibe  iDotoK-fork.  Siiicv  Mcb  doiilile  viliraliou  Iktc  rvpRacnU  lUOlh  ot  a 
wcwmI,  U)9  diiniii<>n  ol'  the  wbnlc  i.iirvo  L«  ralhvr  auirv  iUbd  I'n  m.-cou(). 

2.  In  tlw  tint  pufium  of  ihiit  period,  ftnm  u  to  b,  l)i«ny  b  no  viaible 
rfwuy.  nu  niiiine  nf  tlw  levcir,  »<■  ihoncnltig  of  th?  n)u»cli'. 

T ItfenaiuDiil/'.  thut  i»lowy.»IWlli«  lijiMof  sUitit  1<lOlhM'c«n<l.  tlint 
i1m>  •bortftttog  tx^iii-  Tb»  thMteninr  ■»  *h»wn  by  ihi-  ourvr  i*  ni  lirst  slow, 
bat  ■•-■m  hccmuM  mon-  r«]>i<l,  ami  liirn  I'tnckuii*  sgvi'i  until  it  fvnc)i«»  a 

tsiRium  atr;  thsntiok-  i>liiritouitig  ucctipyiug  rather  titurv  (ban  f|„»eoiiul. 


ria.  ». 


TW  nmrM  tbmi  altof  Ik*  wlcr/mniMFIrd  wllh  Ihr  rnliliP  I  -  >  t*>'v  ''r  <■)')  or  tW  wfillt* 
.  .VinritokkHay,  Uinach  IlKlnnlnii  fl:>rt.>toini  Uie|>lii  ooUDMIal  slih  ltW(B>l->rihalair«r 
,  hi  lU  iiMKaij  la  Uw  «|i  hf,  anil  to  by*  itlia  I'liawu  In  ncu(v>  1ft  lbs  Uitdliif  ten*': 
I  IMa  MadlBC  actvir  [art  Of  Uw  viinviil  Bow  (limuirli  ili«  cnll  4  bKwcKi  the  pnnip  ot  lh» 
I  tbtUM  ti)  ike  Kin  <  lo  ilic  lilniliiiR  >fit«  a,  whll«  ■nothar  pul  >ovi  llimiMik  lli« 
I  iIm  colt  of  Iha  t*et|inu  ilunul  burli  by  ibc  nliv  b,  loUwUiuBiicicmr  il   Kraiu  lh« 
r « Ika  eutnal  IMM*  buk  tuiii*iir|ailv*i  — >  |ol#orc«<lnrth«ps«lllv«al(**iui^irf 
AtUwcwmii  Sinn  Uifnnith  ihv  n(41<y  ih*  I>iii[iniii  •icnal  rrampWI^  Ike  ran)  (■(cull 
[^■COrtlavd  ilnin40Bti  Uw  luiKmiribaaignal     Adhcrnimni  llainlbinuah  IbSCcild, 
rofllMi  iiill,  alan  IcoHiiliif  mitcnellHMl.  •Itainap  Ibc  lover  immi  u(  lli«  lirrt     Dul  Uw  |da 
ln»M)— I  fl  Ihatitwdnialiiir  ■i-i'ibo  iimic  UfU  ibt  fudatof  Ux  >4ii  niiiorilic  rattTiiry.    Iiiroii- 
I  til*  oimal  Mill  Ibiia  b(nk*a  at  llf,  Dckiii  iiritbir  IbRinjfb  >l  tuw  thfuifh  ihc  Imiovii 
ta  ww>|i»MWf.  IhefvMT  of  Ihr  liisi«i!U  thoa  CHUlrii  to  Iv  iimcnvllHil.  Iti*  miukti  flli-* 
Mai  OBMlly  aa^ilvl  liy*(prtD|  nw*  (bamiln  tbe  llfum     But  In  iun**qiii>iip«i.itiliaeiirr«Dl 
[  la  Id**  Ikroatk  4  liio  oui*  oT  4  waw  lo  lift  op  itu  pronit.  aai)  ibv  iilii,  in  Ui*  dwmni  of 
t.  intka  OMIafl  noc*  stw  alUi  (Iw  oian^rr.    Tbt  n^aubluhmunl  nf  ibc  cumni.  hrni- 
iaui«acUa(«a  Uw  two  mIKaaala  pull*  Oma  itio  niukvror  ibcitKnal.  ainl  a«iklii  Xir 
■■■t>aMn«<4|«lka[>Uiv  i«nna  aii4  oma  mon  bnnkt  uia  aiiRwa    Thiu  ih«  vurmt 
%t>f  HNUloand  UiAt*.  iw  niilitltrnruir  imcmipUoaaMwJatcniiined  bit  tberlbntiiia 
>  M  Uw  luklar'ntk.  Bod  ibo  Ivvci  •■€  iw  U|[iu[  tWaf  and  fclUns  ■nicbninuiuly  uua  ika 
■  «f  tkaunilf«-AHk 


4.  Arri^'«d  at  llir  tnaximiim  of  sliortcning,  llic  tnuHcle  at  nuLv  Wgin*  in 
ralas.  the  lowr  ilniiyiiiliiig  al  lint  hIiiwIt.  then  molt'  rapiilly,  anti  at  liwl 
OWt*  tlowly  agaiD.  until  at  J  tlir  niiiflr  hut  n^^intnl  itn  natural  length  ; 
Uw  wholt  rMuni  from  th«  miLsimtiin  of  contrnctinn  tg  tho  natural  kiiglh 
nemiiyin);  ratbrr  more  than  jig  Mcnml. 

Tbiu  a  Mni|>lc  muMnlar  conlnietion,  a  simple  spasm  or  twitch,  praducMl 
by  ■  nonenlarT  aliniuliu.  such  as  a  nnijle  m<lui;lioD-»hock,  cottiiMs  of  three 
iHMii  pliaaM ' 

1.  A  pboMt  aiit>?oed«iit  to  any  vuihle  atteraiioD  in  the  muscle.  This 
phiwi.  dariD);  which  ini-igibl«  preparutory  changes  are  takiug  place  in  lb« 
atrr*  taii  muscle,  is  called  the  "  l-iltitl  periwt." 

%  A  [iliaso  of  aborteniug  or,  iu  tbe  nwre  Mrtct  meaning  of  tbe  word, 
CBOlrartion. 

a.   A  phase  of  relasatioti  or  return  to  the  orixiual  I«:ii|{tb. 

In  the  cose  we  are  coitftderiiij;.  iht  clectroijeii  «n>  ?u[i|>ai«<)  t"  lie  applied 
lo  tfas  oerrc  at  soDie  dbuuice  th>in  the  laiucle.    I'oiuequeDtlr  the  latent 


86 


THE   COXTBACTILK  TISSl'BS. 


pt-rioil  of  ihp  ciirv^'  contprwcs  not  only  the  pre|iiinUorif  actioiisi  ip-in^  <iti  in 
ihc  titUDclc  ilsrlf.  liiil  iil«o  tbo  cbaneM  nevMHirv  it'  conduct  lln:  iitiinnliate 
eflwl  of  the  induct! on  shock  from  the  pnrl  nf  ln«  nerve  IwIwwd  the  I'leo- 
trodcs  itlong  n  cunndcrnblc  length  of  ni.-n,'e  <1«wm  to  tht*  niii«cJr.  tl  in  iihr(. 
ou«  thiit  llicef  Ittltcr  ehiingcs  might  be  climinoteil  hv  placing  the  clcclrudtt 
on  the  muscli?  iteetf  or  oii  the  nerve  close  to  the  nuisclc.  If  this  were  ilonc, 
the  muscle  niid  lever  being  exactly  as  tiofoiv,  nnd  cnra  were  taken  ihnt  the 
in<luclit>n-^iock  eutered  into  the  nerve  at  the  new  epot,  *l  the  momrnt  wltcn 
the  jKiiut  of  the  lever  had  reached  exactly  the  t&ioe  point  of  the  trakvelling 
fturfuce  as  before,  two  curves  would  be  gained  haviug  the  relation*  »honn  in 
Fig.  22.  Tlie  two  curves  reaenible  eaon  other  in  aTmoet  all  point*,  except 
tliat  in  the  curve  taken  with  the  ahorter  piece  of  nerve,  the  Itilent  period, 
ibii  <liatance  a  to  A  a«  compareil  with  the  dtstnaoe  atoh'  U  sliortened  ;  the 
coDiraetion  begins  rattier  earlier.  A  Miidy  nf  the  two  curves  teaches  ae  the 
following  two  fact* : 

no. -a 


0('ii\'™  ii.untinTiwi  Till:  MiMi-suKXT  Of  TiiK  VtiMTrr  nr  *  Xmrow  iMrviA; 

Till!  Mim  tnOKle-iicrTi  |icv|«mllnn  IifMmuUlai  ill  uAirtu  pcslblc  trova  ibo  miMplt.  Oiaa  naai 
M  lUMOile  laitui  muwlc:  tvitbeaauaMantam  K|tl*t*(vil  iii*i«:tl;  llicMauitn)' 

In  |1>  UidiliuuluiiinWnilia  iienv  kt  Iho  llatt  IndlwUid  by  iIm  Un«<i,  IhcountnulloD  bnrliuBib': 
Hid  «  IidU  Uunt  [ie(1iK3.  UwnfUrc,  la  tndlcklcd  17  ihadliQuin  Itoiua  v>  V. 

IB  III  ttiv  •iliniiltiK  niitpn  Ilia  nam  U  ulselly  llin  Hiino  tliiiu  n :  tb(  OnnlnwUon  heflna  U  ft ;  IhC 
lalDQI  [aloil.  ilivRftiir.  I>  liullautd  bf  tha  illgUUM  bvlimn  u  anil  A. 

Thv  Itma  lakoii  iiii  bj'  Uio  iiorvmu  JmtiDlH  In  luainR  »linie  ilu.-  Icnttth  of  aem  lietwwD  I  aiul  I 
li.  Ihcrvfiirc.  lii'tlmtc-l  tiy  thv  i|<«laiicr  balwurs  ft  aiu]  ft',  wtili'li  iiu)  In  mmtund  h;  lb*  limliie-lbrb 
EiiTTo below:  cmctadnablBtllinUouof  ibFiunliv-mk  mrmipuniliiul'lJilof  ilUW8i«0MuJ. 

1.  Shifting  the  electrod«»  ftum  n  point  nf  the  nerve  at  some  distance 
IVoiH  the  muscle  to  &  point  of  the  nerve  close  to  the  muscle  hiif  only  short- 
ened the  Intent  period  a  very  little.  Rron  when  m  very  long  piece  of  nerve 
i«  lakeu  the  iliflerence  in  the  two  curves  ie  very  email,  and,  indeed,  in  order 
that  il  niny  be  clearly  recognized  or  measured,  the  Iravellins  surface  raust 
be  made  to  travel  very  rapidly.  It  is  obvious,  therefore,  tnat  by  fiir  the 
greater  part  of  the  latent  period  in  taken  up  by  changes  in  the  miiicle  iiadf, 
ehanns  preiiumtory  tu  the  actual  visible  ahortenink'.  Of  cuiirae,  even  when 
tbe  ^otroda  are  placed  close  to  tlie  luusole,  the  latent  iteriud  iuchideo  the 
dianeea  going  nii  in  the  iihi<rt  piece  of  nerre  still  K-inii  biMween  tbu  elect  nodes 
and  the  mu«eular  fihrex.  To  eliuiinHte  thi)  with  a  view  of  determining  the 
Intent  period  in  the  musiile  itself,  the  electrodes  might  be  placed  iljrr«Uy  on 
llie  muscle  poiMonvd  niih  nniri.  If  thix  were  done,  it  would  be  found  tluit 
lite  latent  period  reninined  about  the  Nime,  that  is  to  M>y,  that  in  all  case*  the 
Intent  period  is  chieHy  taken  up  by  clinnges  in  the  muscular  w  ilislinguishod 
from  llie  nervous  element*. 

2.  Hiich  iliHerence  as  docs  exist  bclwc«n  the  two  curves  id  the  figure, 
indicates  the  time  taken  up  by  the  propagation,  along  the  piece  of  nerve,  of 
the  chnnge^  set  up  at  the  far  end  of  the  nerve  by  the  induction -shock.  Thcae 
chatigei  we  have  already  ^^poken  of  as  constituting  a  nervous  imi>ul«e  :  and 
ihe  wTiovc  ex|)ei-imeDt  shows  that  it  takes  a  small  but  yet  distinctly  appreci- 


THE   PHK:C0]IEXA   of    UL'SCLB   AST)   SKRVE. 


Mm  Un»  for  ■  Dervoua  iinpiilBe  in  mvtl  atoag  m  aurve.  In  tlie  figure  ihe 
dlflWwKW  betw««n  tbe  two  laleni  iwri'Mln,  the  <Ii4Uinc«  between  b  ainl  h', 
MMDi  «]in«t  too  small  to  ueaMiro  Mcciiraivly ;  btit  it'  a  Umk  piece  of  iierve 
tw  iww)  for  the  experiment,  am)  the  r(>corOiiig  surlacc  bo  made  lo  travel  tery 
&•!.  the  iltfl'creDm  Itclweeu  the  diimli'ni  nl'  tlw  tatcnl  periud  viheu  iW  iniiuc- 
tioo^bock  i*  MOit  ill  ut  a  jMiiui  diwv  to  th<^  ninecle,  and  that  uliea  it  is  seal 
ia  At  a  pnni  a»  far  aviijr  a*  powhlfi  frotu  itic  muitcle.  msy  be  wtidfavtoriljr 
■*—w<a  in  fnictiou  of  a  aocoiid.  If  the  leagili  of  nerve  between  the  two 
|>iijaBi  ba  accnnUtflf  mcaaurtrl,  thv  nil«  at  whicb  a  nervous  impuhe  LraveU 
akmc  Hk  ixirva  to  a  niii«cl<-  ran  tliii«  Ih!  easily  cnlciilated.  Tbii  liru  lie«n 
fiiuM  to  bv  in  the  frug  about  '2'^.  and  in  man  about  33  ni«trt»  |Kir  micoihI, 
bat  raiia*  ci)D8i<k-ra)ily.  csiK-ciallr  in  warin- blooded  auiaiulA. 

Tboa  when  a  inonteDlary  stimulus,  suoli  ns  a  ftincle  iiiduvti(>n-«liock,  i«  wnt 
iDto  a  Bcrve  oODMit.-tetl  with  a  muHcle,  tbe  folUininK  <!vent:i  Inkr  pbu%:  a 
aerroiuitnptiUeiaitsrled  in  the  iten,'e  and  thin  trai-ellingdowii  to  the  muscle 
ptvdacBt  in  ilie  hiuk'Ic:.  lint  the  invisible  cb&n^  which  coiwtitulc  tbu  latent 
pwiod,  aerondiv  Ibf  chanK*"  which  bring  about  Uw  »horteniiig  or  cotilntction 
proMr.uid  thirdly  the  changes  which  brin^  about  the  r*.-lnKatiun  and  rclum 
to  tW  original  Iciii^tlt.  The  change*  taking  place  in  ench  of  these  ihno 
pkaaa  an  change*  of  living  mattvr ;  th<;y  van  with  the  eondition  of  tbfi 
liTiBg  anbatance  of  ibo  ntiuclo,  ami  only  tnke  [ilncr  ra  long  as  tbe  muscle  is 
•liva.  ThoBf[b  the  ralaxntion  which  bring*  back  the  muwle  to  ita  original 
length  ia  aamt«d  by  tiie  muach)  being  loaded  with  a  weight  or  oiherwiM 
Mmcbed,  tbia  ia  not  Msratial  to  tbe  actual  relaxntinn.  and  with  the  same 
load  the  retain  will  vnry  according  to  the  condition  of  tlie  niuecle;  tbe 
rcljuatian  intiit  be  c.xi^idered  as  itn  essential  part  of  the  whole  cuotraction 
DO  IcM  than  ihr  nhorictiiui;  ii^lf. 

$47.  No*  only,  an  we  sliall  ace  later  ou,  dna  the  whole  eontruction  vary 
ia  extant  and  diararter  according  to  the  rondilimi  cif  the  mnm'Ic,  thi- 
•CrtBgth  tif  tbe  indiiction-alKick,  (hi>  loail  whidi  the  muHo  i»  benring,  and 
variottt  attendant  circumntanrM,  but  the  three  phaw*  may  varr  inilepeod- 
■otly.  Tlie  latent  period  may  Ih-  longer  or  thorter,  the  shortening  may  take 
ft  ItUftr  i<r  ahoTter  time  to  rcaoh  tbe  Mine  height,  and  espccinlly  the  relaxa- 
tioe  aiaT  be  aluw  nr  rapid,  complete  or  impiTfect.  Etch  when  the  same 
•Cnngth'of  indaction-altock  is  used  the  oontrartton  may  be  short  and  sharp 
iK  Terr  Xaog  drawn  out.  ao  that  tbo  curves  described  on  a  n^irding  surface 
traTeiliDg  at  the  same  rate  in  tbe  two  c«isca  appear  very  different;  and 
tUMbr  eertain  <-irammanc«.  as  wlien  a  muscle  is  fatigued,  the  relaxation, 
mon  peiticularly  the  laM  part  of  it.  may  be  »o  slow,  that  it  may  be  several 
lecqaai  before  tl>o  tnuselc  really  regaina  its  original  length. 

Hcntn  ifweeay  that  the  duration  of  a  i-imple  muHciilar  contraction  nf  tbe 
gasUvcaemiut  of  a  frog  under  onlinary  cireunuitafltiea  id  about  ^^  second, 
«f  wbirh  jij  is  taken  up  by  (hv  laivni  [>eriod,  f^g  by  the  coiiirarliim,  and 
yfi  br  the  lelasalioD,  those  must  U-  takt^n  as  "round  numli^r*,"  Mated  so 
ae  tn  fce  vaaily  reiBembered.  Thr  duratinn  of  eacji  pha.->e  ti.i  well  ns  of  the 
vfcola  oiiotraciion  varies  in  diffcrrnt  niiimnia,  iu  ditltn^nt  iniiiti'Iw  of  the  tante 
a^flMl,  and  in  tbr  same  muscle  und<'r  ililfi-runt  cnuililious. 

Thr  miiK' If -curve  which  we  have  been  diiw-UKiiiiit  in  a  curve  of  changes 
IB  Ihr  Uugth  onlv  lit  the  rousclo;  Uit  if  the  mu»ote.  Instead  of  lieing  sus- 
peaded.  werv  laid  flat  I'n  a  glass  ptatt.'  aiwi  a  luvcr  laid  over  it«  bcllv,  we 
•hould  Hait,  u|H>a  M'ndini;  an  induct  ion -shook  into  the  nerve,  that  tlie  lever 
«a*  raarti,  ebiiwitig  that  tbe  muscle  during  the  <;ontraciJon  became  thicker. 
Aad,  if  wr  liMkk  a  graphic  r«>eord  of  the  movemente  of  the  lever,  we  should 
in  a  cur^-o  vori'  aimilar  tu  ilte  one  just  diacttssed ;  n^r  a  latent  |ieri<Ml 


iJm  lervr  wuiild  rise,  showing  tliat  the  mitaek  was  getting  thicker,  and 


90 


THK  CONTRACTILE    TISSUKS. 


nftern-Hn)  wciul>)  fnll.  vhouing  that  the  mitsclp  vrxs  beoiming  thiti  m^silL 
In  iillivr  woriI>,  in  coiilracrioii  th<'  Icswiiinz  ot'  lh«  iiitiM-lc  loiigthMisc  is 
ECcxrtiipniiied  hv  nn  iriomiw  croetwiw :  iiideeJ.  m»  ire  shnll  eec  Inlcr  on.  the 
muwie  in  ranCriicling  U  not  ttiriiii)ieh»I  in  l>iilk  nt  all  (or  only  lo  au  exceed- 
iDglv  »mnll  pxiciit.  nbout  htUif  of  ''«  'o^jil  bulk),  bnl  iiiiik«e  up  for  iu 
dimmiitinti  in  length  by  iiicreasing  in  its  other  diaiiKten. 

§4B.  A  single  inOiictioii  shock  if,  ne  we  have  »aii],  the  roost  couvenieot 
form  vl'  atimuTiis  for  proilucinK  a  simple  luusciiUr  coDiroution.  but  thb  may 
also  be  obtained  br  other  aiiniiili  proriileil  that  these  afe  suffidenllv  sudileii 
and  short  io  their  action,  as.  fur  iiisunx'c.  hy  a  priuk  of,  or  a  slurp  blow  oil, 
the  nerve  or  iniuole.  For  the  production  of  a  aingic  Moiple  rauMular  con* 
tmeiion  the  changea  in  the  ncrvi'  Itndini;  Id  the  mu«ol«  miut  be  of  nidi  ■ 
kind  a»  to  coDstitute  wlial  iimr  l>e  cullod  a  kiiiglc  iicrvoua  impube,  and  any 
slituuluB  nhii'b  will  ovoke  a  single  ni!rv»ti:>  iinpulac  only  may  Iw  uwd  tu 
]in)duce  a  tiiinple  mUK'uliir  contraction. 

Aa  a  rule,  howevur,  numt  stimuli,  olhrr  thnn  lingh-  indiitrtlon-thockfl,  toiil 
to  pnxlnce  in  a  lurrvt;  neveral  ni>rvoii.«  impiiUc*.  and,  »n  we  -ihall  sec,  the 
ucrvous  impiilxo  wlii'rh  tmw  from  tin-  central  nerv'itiF  nyeleni  iin<l  m>  mm 
along  nerrcsi  l">  mu»>I(7<.  arc.  n'  a  riik-.  iml  Bini,'lc  and  simple,  but.  i-omplcx. 
Hence,  am  a  mmirr  of  fact,  n  *i:iiplv  niusciilnr  contraction  t>  within  the 
livEog  bo<ly  n  conipiirntirely  rnrv  e\-ent  (at  toiut  m  far  as  the  *keletiil  mus- 
clw  are  concenicd).  and  cunnol  easily  be  produced  onlside  the  b'>dy  ollver- 
wine  than  bv  a  single  induction  shock.  The  ordinsry  lorm  of  muHciilar 
coiilraelinn  is  not  a  finiple  muscular  contraction,  but  the  more  complex 
form  known  as  a  teianic  contmction,  to  tbe  study  of  vhiob  we  must  now 
turn. 

Tehmie  Contndioiu. 

-^49.  If  n  single  inductionnhock  l>e  fidluwed  at  a  certain  interval  by  a 
Swond  i>hcick  of  the  t»tnt:  strength,  the  fir»t  simple  contraction  will  be  fol- 
luued  by  a  wecond  simple  coolraelioii.  both  contractions  being  separate  oikI 
dutincl ;  and  if  the  «liocks  be  repeated  n  series  of  rhythniicallv  recurrioi 
neparatv  Nimple  conlrai-tioiis  may  be  obtained.  If,  however,  the  inienM 
betni-on  two»hocki<  be  made  short,  if,  for  instatioe.  it  he  made  only  just  long 
emmgb  to  allow  the  tirst  contraction  to  have  passed  its  maximum  before  tbe 
Intent  jwriud  of  the  second  is  over,  the  curves  of  the  two  eontructiona  «UI 
iK-dir  some  fwh  relation  to  each  other  aa  thai  shown  iu  Vig.  23.    It  will  Ik 

Fnxa. 


TsuiXQ  or  A  Doi  DLK  Mtxrt.K-'  tjiive, 
n'liUcibe  miuctc  (sutrocnomlut  of  fmKi  hm  ciisucnl  in  iIh  nm  saamoiloo  iubwi  comiM* 
<iMnr.  Iiiul  iiutliliit  InMmnal.  It  liiilinUHl  to  Ilio  diilUil  Uni-i,  *  Hti>i»l  liiilopUuii  •lji>-k   <rmt 
thtDOO  In.al  metis  tlin«  Umi  (Iw  «K:ciud  ronlractloii  Iietan  Jiirt  w  (he  nm  HM  beRliiiilua  loile- 
<lto>.    T1iaTCU»idcur*cI>M*ulaaUn  ftoiiillicafM.M<toa«UiefllnfWiuibeh»»»-UlM. 


observed  that  the  second  curve  is  almost  in  all  reepocla  like  the  first  except 
Uial  it  starts,  so  to  speak,  from  the  linn  curve  iuHtejitl  of  from  the  baae-liue. 


TDK    PSBNOUKXA    OF    Ur9CLK    AM)    NKHVE. 


01 


Tbc  (ceoail  nerruui  inipulw  has  acted  on  the  already  eontraclcd  muacle, 
uiil  Rutdo  it  conlrnii  itKoin  JuM  u  it  would  liav«  dune  if  there  had  be«n  no 
lint  itnpulM  and  (lie  muM-1e  bad  been  M  rcaL  Tbe  tnouunlraclkius  «» 
•ddad  tofvtber  and  tlie  Icwr  u  rntHx)  iiearly  double  tbe  heigbt  ii  would 
bsva  bmo  by  i-iihcr  aloiic.  If  in  the  Mmv  way  a  [bird  shock  follows  the 
Mooad  at  ■  auftii-irtitlv  •liort  iiilirvnl,  a  iblnl  curve  U  pileil  on  (oji  uf  tbe 
Mormd:  t)i«  laruc  wilti  n  fntirlli,  bikI  to  on.  A  more  or  Im*  similar  nwilt 
wnaU  occur  if  tbe  M^iind  cunt rad inn  (K'gnn  nl  another  phaw  of  the  tint. 
Tb*  eombiiiMl  t^ltct  i*.  of  eiiiinM.'.  grvat<vi  whi>fl  iho  Mcond  contmution 
WwJQi  at  ihi*  niiixiniiitn  <>f  the  lint,  being  U-it^  Ixilh  befuni  and  anerwKrd. 

llMin-,  the  mull  uf  a  r<-|H'(iti(>ii  of  thockx  will  depend  lar^ly  OD  the 
mu  of  repetition.     U*,  as  id  Pig.  !24,  the  shocks  follow  each  oilier  »o  slowly 


MtKiJxTvrx.   NBa<  iKvecTiMi  iaota  lurBiTCD  turnvt. 

llutonv  runtrarlion  i>  oTor,  or  almost  over,  before  lh«  next  liegtni,  wch 
tuttractton  will  Iw  dittincl.  or  ncwrly  dialiiict,  and  tli«rv  will  be  littlo  or  no 
cDBibiaed  rifoct. 

If,  b'lwever,  th*  ahucka  be  raiMatMl  mare  rapidly,  lu^  in  Fig.  Ift,  each  mic* 
vediaif  t^utilndiMl  wi)]  Mart  mini  aome  {wrt  of  tlte  prt'ctsliiig  one,  »ud  llie 
Wer  will  l>e  raised  to  a  greater  hei^fal  at  each  contrsc^ioD. 


Miana-erati:.  SaaiM,  Inwcnon  BMoot  Rn-Miiv  Ytott  nirfiM.v, 

If  the  fre()uency  of  the  aliocks  be  eiill  further  iacreaseil.  as  in  Fipf.  2$, 
lit  riae  iluc  to  tbe  coRibiaati'Mi  of  iMnlrction  will  be  still  more  rapid,  and  a 
Waller  part  oi  each  conlnntiou  will  be  visible  on  the  curve. 

la  cacb  nf  tbwe  three  curve»  it  will  be  itoticed  thai  the  character  of  the 
nrrt  dwngw  •omowhat  durinu;  iu  derelopmeoi.    The  change  ts  the  nwult 
of  cocatuneing  fatipie,  cauMid  bjr  the  repetition  of  ihe  contractiofin,  the 
lat^aa  manlfntinf;  iiiielf  bv  aiwt  inereittiii^  prulotiKation  of  rach  ontrac- 
•bowti  especinily  in  a  delay  of  relaxation,  and  by  an  increaning  dioii- 
in  tbe  height  i>f  tlie  conlrnclion.     Thun,  In  Fig.  24,  the  coninctiona 
distinct  at  hr^.  bcc«me  fu*ed  hiier;  the  fiflh  contraction,  for  iniilance, 
a  pcoloBged  to  that  the  ilstb  bvgina  beforr'  tJiO  lever  has  mcbrd  the  ba« 
Im* :  tM  the  *ummit  of  the  sixth  t»  hardly  higher  than  the  BUininit  of  (he 
fifth,  nace  the  sixth,  tliuttgh  itartiiig  at  a  higher  level,  !■  a  somewhat 
weskkrr  contraction.    8ee  also,  in  Fig,  *j'i,  iba  lover  rises  mpidly  at  first  but 


92 


TIIK    COXTHACTILE    TISSUES. 


more  stotvlv  nllenvard,  owiiij^  to  iin  iQcroii^ing  diminution  in  the  liviglit  nf 
tli«  ein>;le  oontr>iclioit«.  In  i-'ig.  '2G  itie  iiiL'reii]«nt  ol'  Hm  of  ihv  ?iirv<'  due 
to  each  cuutraclioo  diiiiitiiahes  verj*  rapidly.  And  though  the  lovor  does  cna- 
tiDtie  to  ri«e  during  the  wiinle  eeries,  tne  oeoent  ttft«r  uliout  ilic  sixtli  cm- 
traction  In  very  t;'''i''"al  itidee^l,  mid  the  iodicntiona  of  tbe  indiviiiuB)  con- 
tractiuiia  are  luucb  lueii  marked  tlian  at  lirst. 


Mi>''i.t<vitv&   SmoLR  bantctuai  iuocx  Rtnuicii  Snix  Monx  RATHni-r 

Hriice,  when  shocks  tin:  rp|j*:iit(.'>l  nitli  sufficient  raiudity,  it  mutta  that 
alter  a  certain  number  of  Hbocki,  the  aittcciMHliutj;  iiiij)ul»e8  do  not  caiue  hny 
lurthur  shortening  of  the  mnicli;.  any  further  raisiof;  of  the  leTer.  but 
merely  keep  un  tbe  i-ont ruction  alrcnily  exixtiog.  The  curve  thus  reachea  a 
maxiiiiuin,  which  it  maintalnE,  subject  tf>  the  depressing  eHects  of  exhaus- 
ti<Hi.  «(>  Icing  as  tJie  shocks  are  n^pcitlcd.  Wlieii  these  cease  to  be  given,  the 
muH'lv  mtums  to  its  natural  length. 

Whun  the  .shocks  succeed  each  other  elill  more  rnpidlv  tluui  in  Fig.  36, 
■  be  individual  contractions,  visible  at  first,  may  become  fused  togttbor  and 
wholly  lost  (o  view  in  the  latter  pait  of  the  curve,  fflieo  the  snocks  suc- 
ceed each  other  still  more  rapidly  i  the  fecond  contraction  banning  inltw 
ascendinfc  (Kirlion  nf  the  fintt)  it  becumet  difficult  or  imnonible  to  ttMB 
nut  any  of  the  nngle  contractions.'     Tbe  curve  then  descriWl  by  the  tw^r 


nruc*  ratamD  wru  Tire  ohiihiibt  Hwano  tmaRi-ma  or  tn  ixin'mosMucMa'a. 

iR(<oiii>liriii»irilwau»vsUlasitiiiily.) 

TIic  lnl«mi[it«l  ciUTeiit  U  lliraw>  In  «l  0. 

Uof  the  kind  ibowo  in  Pig.  '27.  where  the  primary  current  of  an  induction- 
machine  vm  rapidly  made  and  broken  by  the  mit^etic  interruptor.  Ki|{.  \^. 

•  Tbe  <•>•  nlih  nhub  Oir  iciilivl.liul  «(niinuUQM  «m  Ii*  aMilc  otii  ilu|it»4t  la  iMn.  II  uwri 
Innlly  boBtld.iB  Ibenpwlnr '■■(■>"'■"''' "'*'""'*"*'  •"•«>■»  mnl. 


TUB   rilKNOUENA  or   MI'SCLR   axd  nkrvk. 


98 


I 


I 


TIm  l«T«r.  it  trill  bo  obfm-Ml,  rian  nl  a  (ihe  roeording  Hirface  is  tntrolling 
too  aluwljr  to  nllow  th«  Intent  p!^ril>>)  tt>  ho  dialin^nicbi'd),  at  firat  very 
lapidlr,  in  fact  iti  nu  unbroken  bikI  iilmnrt  s  vertical  line,  sinl  mi  v«ry 
ipffrdiW  rrMtMfl  tbe  maxiiniim.  nhich  is  iDttiDlJiin«d  m  Iod;*  m  the  sItocM 
aoattouc  Id  be  gircn :  whva  tbew-  rvaso  to  bi'  given,  tbe  curve  <le6i-etid5  at 
fltiC  nrj  rmpiilTy  and  tben  more  nod  more  graduBlljr  toward  th«  baK-lioc, 
«Uel)  ]t  mchea  just  at  the  end  or  ihe  li^ure. 

Tb^  onxtrtion  of  mtiH-le,  broiisbt  about  bj  rapidly  repeated  aliockit,  thia 
ftiaioB  uf  a  number  ul'  simple  tnicliea  into  an  apparenllv  unoolh  coutinuout 
•Act.  li  knuvB  aa  lefamu  or  utaiiit  eontraetutH.  'i  h«  afwve  fteu  ar«  mott 
daatli'  (liowQ  when  induct ioii-obticka,  or  at  leaM  galvanic  currents  id  aonM 
(bfTD  or  <i<ber,  arc  enploved.  Tbey  are  tevn,  however,  nbut^virr  bo  ihf  form 
of  rtiniulti*  enploTMl.  Tliut,  in  the  cow  of  nirchaiiical  Miniuli,  nhilc  a 
Bingtv  i|aick  bloit  tuny  eaiuie  a  ijngb;  iwilfb,  a  pruiMunL-ed  telanux  may  bo 
obuiovd  by  r«i>idty  ntriking  iiuccCMvely  frtwh  {mrtionii  nf  a  uervi;.  With 
rbcmieoJ  Minintatinn,  n.*  nbcn  a  nrrve  in  dip[>e(l  in  noid,  it  a  imponiibki  to 
M«ra  a  iiionMjiitarv  applicalton ;  bciic«  t«taDu»,  generally  invgular  in  rhar- 
■cc«r.  i»  tbo  normal  n.*iilt  uf  thin  mod*  of  slimufation.  tn  tho  living  body. 
tbm  diHirartions  of  thu  fkclctnl  nniFcle*,  bnnight  aboat  cither  by  Ihe  will  or 
aCbanriae,  an  g«D«rsUy  (etanie  tii  vhararler.  Kvcn  very  short  sUarp  raove- 
Wl  at  I.  micb  as  a  sud4l«n  jerk  of  a  limb  or  a  wink  of  tlie  eyelid,  are  in  mlity 
ejUUBttlti  of  telaiiu!'  of  snort  ditrntion. 

Ifiht  fever,  instead  of  being  fastened  to  the  tendon  of  a  muscle  hung  rer- 
tleallT,  be  laid  aenea  tbe  belly  of  »  tuasole  placed  in  a  hortxonlal  position 
and  ihf  wuscte  be  thrown  iiilo  tetanus  by  a  rt-jwiilion  of  indiK-tion-shocka,  it 
will  be  seen  that  each  »lii)nenint;  of  tbe  muiu'le  is  aocompiuiied  b^  a  corni- 
■pawdtpg  thickening,  and  thai  tlit?  tulal  shurieniiii.'  ^^f  'bt-  tetanus  is  accom* 
pntl^*^  by  a  r<>rrr"])"nditi^'  total  lliie kitting.  Ami,  imler^l,  in  lelanit*  we  can 
obwrrs  more  easily  than  in  u  Hltiglo  oontraetiou  that  Ihe  muscle  in  coniraet- 
htg  cJuiagfa  in  form  onlv'-not  in  tmlk.  If  a  living  muscte  or  group  of 
wpaclfti  be  pla»<l  in  ■  glaaa  jar  or  chamber,  (he  cIomvI  lop  of  whivn  is  pro- 
IniMial  into  a  narrow  glasB  lube,  aud  tlie  chamber  be  filled  with  water  (or 
plWMbly  with  a  solution  of  sodium  chloride,  0.6  per  ocot.  in  strength, 
noallT  eallol  "  normal  *aliDe  solution,"  which  is  kas  injurious  to  the  tiuue 
than  nm|)le  water)  until  the  water  rises  into  iIk-  narrow  tube,  it  is  obvious 
tliai  any  change  in  the  bulk  of  tbe  muscle  will  be  easily  shown  by  a  rising 
or  UIIbc  of  tlie  column  of  fluid  in  the  oarraw  tube.  It  is  found  that  wbieu 
lb*  mmole  i*  made  to  contract,  even  tn  the  most  forcible  manner,  ihe  obange 
of  l*f<ri  in  tbe  beighl  of  the  column  which  con  be  observed  is  practically 
inrffiiiii  am  :  there  apfiears  to  be  a  fall  indicating  a  diiDinnliou  of  bulk  to 
lbo«xl«iilofal>oul»ne  ten-thousandth  uftlw  total  bulkufibemuM-le.  ^hi  that 
««  Btay  fiiirly  wiv  that  in  a  tetanus,  iu>d  henoe  in  a  ximnle  ountraclioii,  tbe 
l^Broing  iif  tlii>  length  uf  ibe  muscle  causes  a  c<>rrt?|iunding  inerva>e  tn  tliC 
otWr  rlin-<-iJoM :  tbe  aubstaace  of  ihi-  muwobr  in  diH|ilaccd,  o«  diminisbad. 

f  M.  .Si  far  we  liaresfMiken  simply  of  an  indiietmn-aliock  orof  inductfen- 
■bnaks  withool  any  referencv  t»  their  Mnmgth,  and  of  a  living  or  irritablu 
moscU  viihoui  any  reference  to  the  degree  or  extent  of  it*  irritjtbility.  But 
indvcti'ia-shaeks  may  vary  in  i4rcngt£,  and  tlm  irritability  of  the  niuxcle 
nsr  Tarr. 

if  «T  slide  tbe  secondary  cnil  a  long  way  from  iIh^  primary*  coil,  and  thus 
anke  use  of  extremely  feoule  induct ion-shiicks.  we  shall  probably  Hnd  that 
iteBabocka,  applieil  even  to  a  <)Liilc  fn?>h  miuch- nerve  preparation,  produce 
SO  oMtlraottoo.  If  ne  then  gradually  *lide  the  K-conoary  coil  twarer  and 
SSWar  the  primary  coil,  ami  keep  un  trying  the  etfecis  of  tbe  shocks,  we  fhall 
i»d  tbit  kftar  a'while,  in  a  certain  position  of  the  coils,  a  very  feeble  ooo- 


»4 


THE    CONTBACTILK   TISSUES. 


IrHctioii  nmkiw  iu  sppcaranoe.  As  the  tocondary  coil  comn  still  nnrar  to 
iitv  [irimary  coil,  the  coutniCtiotiH  gmw  grenlcr  anil  greater.  AD«r  n  wliilo, 
however — nml  that,  indeed,  in  onlinnr}'  circiiiniitiiiiri^,  vcrv  ipccdilv — incroms- 
injf  rha^ntreiigthof  the*Iii)ck  no  loiiu^r  ini.TniuN.w  thu  height  >rf  Lht:  roninidion  ; 
the  msxiniuni  contnu-linii  of  which  the  iniiwle  u  cnpahlo  with  «ucb  shocks, 
Imwcvct  strong,  hiw  Ih-wi  rwiohcl. 

If  wc  080  a  tetiuiixing  or  interrupted  cnrn'nl,  we  ehall  ohtjiin  ihe  same 
gcnernl  results:  wo  Ria)-,  nccnn)ii>g  la  the  stnmglh  of  the  current,  get  no 
eoNtrmcli'on  at  nil.  or  cuntrncttoRfi  >.'(  vnrioue  extent  up  to  a  maximum,  which 
eiiunot  be  exceeded.  Under  fnvomble  eonditiaii»  the  maximum  ooniractiun 
niny  be  very  considerable:  the  shortening  in  tetanus  may  amouiit  to  three- 
fifths  of  the  total  length  of  the  muscle. 

The  amount  of  coDtmctiou,  then,  depends  on  the  strength  of  the  Mimului, 
whatever  be  Ihe  stimulus:  but  this  holds  good  wiili in  certain  liinilaooly; 
lo  this  poiDl,  however,  we  shall  return  later  on. 

S  91.  If,  having  ascerlaioed  in  a  wrtectly  freeh  luueele-nerve  pre|«rnLiun 
the  amount  of  c;nlrai:tiiiu  produced  by  this  aud  thnt  eitreuglh  of  »iimulu«, 
ire  leave  tlie  preparation  by  itself  for  some  time — auy  for  a  few  hount — and 
then  repeat  the  observitliuus.  we  shall  Sud  that  stronger  stimuli — atrongor 
^flcks,  for  intttanee — an>  reijuired  l»  produce  the  «iue  iinmunt  of  cnnlractiiu 
lift  before;  that  in  to  tiay,  tlie  irritability  of  tlie  preiiuretiou,  the  power  to 
respond  to  stimuli,  hti^i  in  the  meanwhile  d i nil iii shed.  Af^r  a  lurthor 
iDlorvaJ  we  sliould  find  the  iTritabilily  still  fnrlbrr  diminishv<l :  even  very 
strong  shocks  would  he  unable  tu  uvgke  ci>T>travliiini>  lU'  large  n*  thoet-  pre- 
Tinush-  caused  by  w«ik  shocks.  At  laat  we  ■■■hoiild  lind  that  no  shocks,  no 
stimuli,  however  strong,  were  able  to  produce  any  visible  oonlrnction  what- 
ever. The  amount  of  •■ontriiriiuii.  in  fuel,  evoked  by  a  stimulus  depends  not 
only  on  the  Atren^th  of  the  stimulus,  but  also  on  the  degree  of  irritability  of 
Uie  musclu-Dorve  preparation. 

Imniediiitely  upon  removal  from  the  body,  Ihe  preparation  poawnoca  • 
certain  amount  of  irrilabilily,  not  ditTerin^  very  materially  from  that  which 
the  muscle  nml  nerve  puuewM  while  witbm  mid  formioK  an  int(!(cral  [Jitrt  of 
the  body;  but  after  removal  fn)m  the  body  the  preparation  loaeairritabilily, 
the  rale' of  lorn  bein^  dep)-iidcnt  ud  ii  variety  of  cin-umatanoea;  and  thixgotw 
on  until,  since  no  stimulus  which  wi-  can  apply  will  give  liae  to  a  oontraC' 
tion.  we  say  the  irriuibilily  bus  wholly  dinappctAred. 

We  might  lake  this  diiappcaranoe  of  irrittibility  bh  marking  the  death  of 
the  preparation,  but  it  is  followed  aocmer  or  later  by  it  curimi:!  change  iu  the 
luuBcle,  nhich  is  called  rigor  mortis,  and  which  wr  4iall  Mudy  pnveiilly  :  and 
it  is  convenient  to  regard  this  rigor  morti."  iw  niarkinu;  thu  death  of  the  muscle. 

Tbe  irntable  muscle,  then,  when  slimuUlcd  eitlicr  directly,  the  stimulus 
Mail  aiipliixl  to  itself,  or  indirectly,  the  slirauhi:>  being  applied  lo  iis  nerve, 
reapond»  to  the  elimulus  bv  n  change  of  form  which  in  i,«w,-Jilinlly  a  shorten- 
ing and  tliiekening.  By  the  »horU;ntng  (mid  ihickiiiiiig)  the  muscle  in  oon- 
trndiiig  i*  able  to  do  work,  to  move  the  |uiri«  to  which  it  is  attached ;  it  thus 
tol*  free  energy.  We  have  now  lo  study  more  in  detail  how  this  energy 
i^  set  fn-e,  and  the  laws  which  regulate  it«  oxpvnditure. 

Ox   TIIK  C'IIaKQIA   which   TaKK  PlAPB   in    a    Ml'SC'LE  DCKIXO    A 

■  OoNTKAt-TION.  ^M 

B  The  Cbanffe  in  Form.  ^H 

^fiS-  Tfie  yrat*  tirveUirf  of  mimrtc.  An  nrdinart'  skeletal  iniiscle  onn- 
nsta  of  e/onenturjr  muKUjibret,  bouod  together  in  variously  arranged  bttodles 


CIlANOES    IN    A    UL'SCLE   DrRING   CONTRACTION. 


95 


.acctive  tMue  wliicli  carria  bli>odT««el>,  avrves,  ■itd  1]rmphatie&  [Fig. 

The  Min«  cMiDcdlve  timoe,  IwvhIm  Aipjilyin^  u  mora  ur  tcM  ilistinot 

tiffiaf  fctr  Uw  wboU  mutclc.  Toraut  thr  two  ■■tiili  ol'  the  iiiiieclc.  Iteing  Iters 


(mn  KUltv.  lu  «l>ef«  tliv  miitK-lc  iipix-im  lo  be  iJirectly  nltached  to  R 
Imoc^  aai  %  •null  amuutit  oiilr  ot  wnncctivo  titwic  joins  th«  niusoulitr  fibrae 
to  tbr  iicri'ii4<-uni,  M>tnetiiii(4  nliuiidimt,  us  when  tli«  cunnoctive  tissue  in 
whkh  tor  muvnilnr  tilinv  imiiHilintrlr  end  is  prolonged  iuUi  a  tendiMi. 

EmIi  flkaiCDlarjr  fibre,  nhich  viim«  ev«it  in  the  lunnimiit  in  li-nL-tb  and 
brMkdtb  (ta  ibt  tng  iW  dimrn; ions  vnry  rcry  iri^tely  <,  but  may  he  «aid,  on  an 
Avcngt,  lo  be  30  or  40  mm,  in  length  and  'iOu  to  30"  in  breailtb,  coosieU  of 
•a  ifiiitic  botnogtDMiu^  or  fnintl}-  librilhiied  «Ii«aili  of  peculiar  nature,  the 
mrt»hmma.   which  embrmcn  »nd  lurms  on  enrelufX!  fur   thi:  ttriaUd   miu- 

'jr  m^antf  tiiihin.    [Fig.  29.]     Each  fibre,  cj'lindrical  in  form,  giving  a 

rin.  Ifc 


.  MmoM  rwiii  Till  nnutn-HMTOtD  im  Han  (mapiUWil  M  ilmMi      u.  tiWi- 
•■I  tMtatfitan:  hlMalcDhn;  r.  iiiwtnal  pmmr^ami  d.Mn. 
nk.  w  — Fuajoan  or  fttRmir  KitMartmy  Pibmw.  tiitdrDM  i  Clurivt  n  orMiran  DnacnoM 
I  «■  aiMBHcrx. 

Itlamcr.  Ttao Uwcltodlntl aiiAitiianvnennMaKhiitfaMvii.  Aotnc lansitndtnal 
r  anil  *klrt  ihkii  tin  nM,  u>4  an  out  aHMImunD  IMin  end  to  *n>L  Tliln  naiilu  Itom 
■  of  tlwMtlllr.  caWllaMfonMfrcanncaBMlisrbr  TlotonMiltlMtookSiinUl 
.■Mlnwkad  tgtimmwwtlla«»crmt||inrlilt>iotlnncoBUieatrp:t'<*miiijwiHwo 
■  nnmwntf  inminwl  brtha  MfaimioddiifleaMllv  mwnMsbly  nucniiMj:  at  r*  iba 
I  inBmam  Iiiimm*  all  pntVdlx  ncnitanf.  •'•'I  ll>r  mrlUilFd  tfaicn  ivrMilr  nMaiifo- 
bar  M  ■*  llw  konlcn  m  ^aUiifsd  am]  the  tfiaaii  Inail-Iitr.  Wbcii  mon  (Ilnlatl  and  deDiillp. 
am  HaWfc  tWBM  llw  fc«»it  ut  Ihao  app^mneai. 

•lai«W&   Tka  Imgllndlaal  llnoi  an  tnmilj  TWbl*    s.  inconiplrtr  ftutor*  bHOB- 

niDuatf  •  4Ih)  wlilch  •(>«•<*<•  aCTCB  Ibe  lMer«a>  and  (ttaini  the  tnvfniniHmJl 

TW>d|*«>4*utibc»iif  tUa  diM  an  •*•«  tu  t*  ■iuuMl)'  jmnulu.  tte  inaaiih* 

laflnitir  tiitli»iiilckM«<>rtk«dlMaAd  tn  ibr  dMaaov  Mratvn  Uw  Mhi  laatHuilliial 

■tM  bomIt  •StiiibDl :   y.  ilttaclMil  AIM.  mut*  bifklj  tnacnlacd.  alioaliw  lh« 


r 


KwiiMiIti 

or  laM  circular  outliiK  in  iransverw  aection,  ^nerally  taper*  oS  at  each 
^d  in  a  cunJeal  fonn. 

Ai  oub  «n<l  of  ihtt  fibre  the  mroolemma.  to  which  in  life  the  muscular 
■abMuKV  i*  lullimnl,  bvoomea  continuouH  with  fibrilUe  of  connective  tissue. 
Whao  Uw  «tul  of  lliv  fibre  li««  ni  the  end  of  the  muacle,  these  conntwlive- 
^mam  fihrilln  |Maa  directly  intii  the  tendon  (or  into  the  ueiiaateuin,  etc.)  and 
ia  (nat*  CBMB  of  uniill  muvctui  which  are  no  longer  tnun  their  conatitueut 
Ana,  CMcIt  fibre  may  ihui  join  at  <«cfa  end  uf  iLMlf.  by  means  of  its  aareo- 
Jmmos.  the  t«Dd>in,  ur  other  ending  of  the  muMle.  In  a  verr  large  number 
«f  ■iitlw.  b»wovcr,  the  niuM-Ie  >•  liir  lunger  than  any  of  iiH  fibres,  and  there 
m^  be  «Ten  whole  twndica  of  tibrca  io  lue  middle  uf  tW  muscle  which  do 


X 


96 


TrtE    COVTRAi-TlLK    TISSfES. 


DOt  renc^  to  either  cud.  In  such  com  the  ominective  tinuc  in  wtiich  tbt 
t»n!o\emma  ends  is  L''.>ntii)UouR  with  ihc  couiicctive  Iimuo  which,  niiiRin^ 
l>etweci)  the  fibres  mid  between  the  I>uiid]e8.  hinds  ihe  fibm  intu  email 
biiudles.  aiid  the  !»Jitaller  Iniixllcs  intu  ]ar)^r  buiidlca. 

Tlie  conlraetioo  of  a  riiusele  is  the  c-uutracliciii  of  all  or  eome  of  il» 
cknieiilury  librea.  the  timneelive  liiaue  Wiuu  paaiive;  heoce  while  thoee 
fihrta  of  the  iiiuttcle  which  end  direetly  iti  the  tetidoii.  in  coutraeiiu);  pull 
directly  on  the  teudon,  ihuoe  which  do  Dot  ho  ciid  |iuU  iiitllreetlT  on  the  teudoo 
bv  nMuini>  of  tbe  cunnei-live  liwue  between  the  bundles,  wbicb  connective 
tfariie  ia  <^AUtiiiuoui«  with  the  teiidou. 

Th«  bloodv«aseli  run  in  the  coiin«ctivtt  tiwue  hotwet-n  the  buodlee  and 
bctw«cii  the  Gbres.aiid  Ihe  capillariM  form  mori;  or  K«>  rectangular  networks 
i  mined  lately  outside  ilie  narcoleitinin.  [Fig.  30.]  Lympbaiic  vc«els  al>»  run 
iu  the  coDne(.'ii\'(.-  ti»iui\  id  llio  lymjih  tipncv?  of  which  they  bcE'i-  Kacli 
iiiufcularlihre  isthu»Kiirrounde'l  by  lymjih  fpnt-c*  and  capilliirj' bti>odvca«eU. 
but  tlw  active  uuiBriilar  MutNitancc  of  the  Irbre  is  »(<paralG>d  from  the*C  by  ibe 
uroolemnia;  hi-in-*-  ibe  interchange  between  the  blood  and  tlie  CDUKiilar 
8ubaUui€«  a  i-arrieil  on  backward  and  forward  througti  the  cajiillary  wall, 
tbrou|rii  aomo  >>t'  tho  Irninh  gpacea.  and  through  the  earcoletnina. 

Each  luusclv  i»  «iiiiphcd  by  one  or  more  branches  of  ner\'e#  ronipowd  of 
luedullalod  fibres,  with  n  certain  proportion  of  n(m-iiiedullate<l  Hbm.  Time 
branehos  running  in  tbe  ci^nneoiive  ttEsue  divide  into  Bnmller  branehea  and 
IwigB  between  tbcbuniUesaiid  fibres.  S.i[iie  of  the  nerve  fibres  are  dislributMl 
Ki  tlte  bloodvcKels.  and  otherv  end  iu  a  manner  of  which  we  shall  s|)eak  later 
t>n  in  lrealin<;  of  muscular  ^nBatimid;  but  by  fur  the  greater  pan  of  tbe 
iiiedullaled  fibres  end  in  the  muHeuhir  tihrRt,  llicnrraiigement  being  such  that 
every  muscular  fibre  is  ;uppli(h]    with  ut  least  one  niedullat«d  nerve  fibre, 

which  joins  the  niuHculnr  fibre  somewltere  abotit 
the  middle  between  Its  ttro  ends  or  winietimei 
nearer  one  end,  in  a  special  norve  ending,  of 
which  we  shall  pi'eseiitly  havo  to  e]>cak,  called 
an  fit'l-p/ate.  [Hr.  31. J  Tbe  norvc  lihn"»  thua 
ii<-»tinei:l  lo  end  iu  the  niUHColar  fibre?  divide 
as  they  enter  the  luujcle,  so  that  what,  as  U 
enters  tbe  luusole,  i«  a  single  nerve  fibre,  may, 

in.., «. 


r! 


I  MiM-LE,  ^juicn.  mini  moaiuK  or  Ooul 


CIIA>*fllI8    IK    A    XL'SCLK    l>l'lll>'0    roNTRAl'TION. 


97 


I 


by  (IWiilingi.  end  iu>  »cv«nil  ucrve  fibrcB  In  MrenI  musctilnr  llttrt^.  SntiietiiDM 
twoDarwlibttt  j<^iaoii«  tnu»citlnr  ftbre.  line  in  thin  caw  (lio  i>iiiI-i>1bi«  of  c«rh 
tiem  ^br«  i*  •Ull  lU  totao  duiunri'  rniiu  lht>  end  of  lh«  tiiunciiliir  fibre.  It 
Mknn  tb»i  wtiCD  ■  mtiMulMr  fibre  i>  MimulAtiHl  by  nioiiiu  nC  n  nnrvc  tibrc, 
Um  DfTVow  imputw  tnNfllin^  ilon-n  lh«  ii«n-«  fibiv  fulU  inln  ihc  iiiii«c>ilftr 
Sbra  Oflt  It  MM  rD<)  but  Hi  nlioiit  ibi  mitbllp;  ii  Ik  tin:  ^tilltlK^  of  llii'  fibri> 
which  it  mitbeui  firet  by  the  ncrvout  iinpiiW,  anil  l)ir  i-lninKiv  in  tl>u  muwTuUr 
mImum*  lUrUd  in  the  nii<t<)l(?  of  tlu'  miuciilnr  Hbri;.  Irnvt')  ih«Dc«  to  th«  tvro 
«iKlt  of  tfao  fibfo.  In  an  onlinary  ekckitil  nitieck.  h»w«rcr,  tm  wt  have  Mi<t, 
th«  flbrw  ami  Imiidlm  of  libm  Wgiu  and  end  al  dilTiTcnit  di»Iiinc»  from  l)i« 
tads  of  tb*>  mu«clt>,  and  the  nerve  or  ncfvr»  gnin];  to  ibc  mi»ol<>  dividv  itnd 
»pwd  oat  in  th«  mii6clt>  in  sucb  a  way  ibat  rlie  end-(>lat«a,  in  which  tb« 
ntdividoal  fibrea  of  the  nen-e  end,  are  distributed  wideir  over  the  rium-I)?  nt 
van*  tHflbrail  diataacw  (hini  the  endp  of  the  miifcle.  Hpnoe,  if  we  iiippuao 
•  '(m}e  nervooB  impulse.  Mich  ae  thnt  eeserated  by  a  tinjjle  induction -shock, 
or  KMrkaofsucb  impulsei*  to  lie  started  at  the  ^nie  time  at  sonic  nnrt  of  the 
■rank  of  the  iMrve  in  «ich  of  i)i«  fibres  of  the  nerve  ^'oinj*  to  tne  muscle, 
the«  impulMa  irill  mu-b  rery  diflerait  ports  ofthe  muscle  ai  about  the  same 
line  uia  tbe  eontrai-ttons  u'bi<^h  Ihey  set  >r<iin|;  will  bcf^n.so  to  speak,  nearly 
all  oTar  the  whole  uniMk  at  ihv  oiime  time,  iiud  will  not  all  stan  in  any  par- 
liealar  tone  or  area  of  ti»e  muscle. 

f  SS.  7%r  •I'liw  of  eonlraetion.  We  have  leeD,  however,  that  under  lh« 
iaBlMPca  of  uniri  th«  nervi?  fibre  i^i  iin:ilile  to  excite  cnntmctiona  in  a  mu*- 
rsUr  flbre,  altlmugb  iIk  irrilahilily  iif  ibv  muicular  fibre  itmlf  i«  retained. 
Hmmm  in  tt  miucla  poiwned  by  timri  the  contmotion  bl^^^«  nt  that  |uirl  of 
tbe  BiMDnUr  Mbaunce  which  io  finit  ntlvctcd  by  the  Mimulns,  and  vrt  inay 
•urt  a  tininnion  in  what  |>nrt  of  the  mutvlc  we  (ilouc  by  properly  placinjr 
lb*  plirirodea. 

Attar  niinclea,aovh  for  inetaooe  as  the  •nrforiiM  of  ihefras,  thouf^h  of  some 
ijctfa,  an  compneed  of  fibres  which  run  parallel  lo  each  other  tVom  one  end 
ibr  miucle  to  the  other.  If  such  a  muscle  be  poisoned  with  uraii  so  as  to 
If  the  action  of  the  nervce  and  itimulaied  iii  one  end  (an  iuducliou- 
Atk  vui  ibroufib  a  pair  of  electrotlM  placed  at  some  little  dblaoce  a|Mn 
tnm  each  uiber  at  the  end  of  tbeuiUM^le  may  lieempluyed.biit  betior  remlia 
■rwobuIneH  if  a  mo<le  of  mimulaiion.  of  which  we  shall  have  to  Mx-ak  jirm- 
cntlr,  vtL  thr  application  of  the  "  cunstani  current,"  Iw  Bdo]>t«il),  lh«-  con* 
inctinn  which  emueaHartit  from  ilwondnlimulaled,  ami  Inivcis  ih«nco  along 
lb*  BiMcle^  If  two  lever*  tn;  m»d<.' t<i  rc«ton,or  be  su^^jirnded  fnim.lwi  [Mirta 
nf  Mch  ft  tORDcl*  plac«d  horijiiinlally,  the  pnrla  being  at  n  known  dialancc 
fwvn*  iind  iVoni  the  part  (timnlatcd,  iheprwgrewof  the  conimctioa 

BMlr  U  in 

The  noreiDcnl*  of  ihr  li^%'cr*  indimtu  in  thui  cn,-«i>  lh<- thickcnio)!  of  tho 
flfana  which  U  takini;  place  ut  the  juiri*  '•»  which  Ihi-  lever*  nvi  or  to  which 
ibey  an  attached;  aiid  if  we  take  n  graphic  record  oJ'  ihme  movements, 
briegfaif  the  Iwo  h>ver!  to  mark,  one  immi-diately  below  the  other,  we  Khali 
felt  that  the  kver  near«r  the  part  «(imulatcd  hegiiw  to  mo^-e  earlier,  rnachea 
lu  amimura  rarlier.  and  return*  lo  n^t  earlier  than  dric«  the  further  lever, 
TIn  nAlraction.  started  by  the  ctimnlus.  in  travelling  nhing  the  oiuacle  from 
iba  pari  iiimnlated  raaohea  the  nearer  lever  some  little  lime  before  it  reaches 
the  (briber  lever,  aud  has  passed  by  the  nearer  lever  some  littto  lime  Iwfore 
t(  baa  fauaed  bv  the  further  lever;  ami  the  fnrther  apart  the  Iwo  levers  are 
I  In  Miaali  I  will  Iw  th^-diNVrence  in  time  between  their  movements.     In  oiher 

wiinU,  thv  ' ti  iraveU  aloiij;  ihe  muscle  in  the  form  of  n  wave,  each 

jmn  uf  tbi  II.  succmnon  from  the  end  Blitnuluteil  swelling;  out  and 

ibartaniog  aa  the  contraelioo  reacbea  it,  and  then  reiuniioK  to  ils  oripnnl 


98 


THB  CONTBACTILK  TISS0] 


atnlo.  And  nhat  in  true  of  the  oJlectiini  of  iiHratli>l  fil>ron  nhich  vn-  cnll  tl 
RHiwlc  U  alio  Irii6  uf  ciu'h  fibrv.  tar  tin*  s»Flliiij;  ut  iiiiy  [ictrt  uf  tin-  inusole  if 
ooly  the  ftiim  af  thi^  •wolUii);  ol'  lli<;  iinltviiluiil  &\in» ;  aiKl  if  irv  wera  aUv  to 
uk«  n  Hiiigle  long  fibrv  nml  MiniiiliUi'  it  itt  one  vml.  we  »hoiilil  be  nble, 
iindrr  tlif  mierwcopc,  lo  ««MniwrIling  or  bulging  ncciimpnniitl  bv»  eniTfr- 
■pnn<)iiig»liorlciiiiig,  I.  r,  toMu  n  con  traction,  «vrccpuluiig  (hetibre  fronj  end 
to  end. 

If,  !n  (he  graphic  rccnnl  of  the  two  icvtn  jiiM  mentioned,  wo  count  tbe 
Dumber  of  ribmlione  of  llie  tuning-fork  which  iDlcrreiie  Wtwecn  the  mark 
on  tho  record  which  iudicatce  the  ttcginning  of  the  rise  of  the  near  lever 
FthBtis.lh«nrrivHl  of  the  contraction  wni'cnt  lhi«  lever)  and  the  lunrk  which 
indicaim  the  Wftinniiig  of  ihc  ru«  of  the  tar  lever,  thia  will  give  ub  the  tiuie 
which  it  has  tnken  the  coutraclian  w.tve  lo  trtivel  from  the  near  to  the  fttr 
lever.  Let  uh  suppoM?  lhi»io  he  0.006  wcoiid.  Let  iia  euppose  the  dttitanve 
between  llie  two  levers  to  he  lo  mm.  The  coiiiraclion  w»ve.  then,  hn*  taken 
0.006  wcdnd  to  travel  lo  mm.,  that  is  to  sia.v  it  has  travelled  at  the  rate  of  3 
oieirM  per  tti-ruud.  And  indeed  we  liiid  l\r  thia.  or  hy  otlier  loethodn,  ttiat  in  the 
frog'*  muHeteD  the  cuutractiou  wave  dues  travel  at  a  rale  which  may  Iv  put 
down  Hf  from  '-i  tn  4  nietrai  u  second,  thmixh  ii  varie«  umlrr  'litfcn'iu  mndi* 
tioHH.  In  ihr  wiirni-hliiiHhxl  nmmiiml  the  rate  b  aonewhat  greiiter,  nnd  majr 
pnilmhl  y  l>e  put  down  tit  5  roetrcii  a  iccntid  iu  the  exdaed  miiH'lc,  rising  poe- 
*ibly  to  10  niein:'?  in  x  nuivcle  within  the  living  body. 

If,  ognin,  in  thu  graphic  recoril  of  the  two  leven  we  couni,  in  th*  esse  of 
cither  l«ver,  the  number  of  vibrittiona  of  the  tuning-fork  trhieb  intervene 
betwe«n  the  mark  where  the  lever  liegin«  to  rise  an<l  the  murk  where  it  ha* 
finished  ilH  fnll  nml  returnni  to  the  ba»e-line,  we  onii  menxitre  the  time  inter- 
vening between  the  contraction  wave  rr-aching  the  la\'er  and  Icnving  tbo  lever 
on  its  way  onward,  Ihikt  is  to  say  wc  on  mi-asurv  the  time  which  it  hB«  taken 
the  contraction  wave  to  para  over  the  part  of  tbe  muiicle  on  which  the  Ivrer 
is  rwting.  Let  ua  aupjHHe  this  time  to  be,  say,  0.1  Eccond.  But  a  wave  which 
iit  travelling  at  the  rate  of  3  metres  a  eecond  and  takes  0.1  docuiiiI  to  paw 
over  anv  |<oint  muhl  lie  300  mm.  long.  And.  indet^^l,  we  find  that  in  the 
trva  the  length  uf  the  couti-action  wave  may  be  ]>ui  down  as  varying  froni 
200  li>  -too  mm.,  ami  in  the  mnmnial  it  h  not  very  dillWent. 

Now,  a*  wf  have  naid,  thL>  very  longt«l  luiisciilar  tlbre  U  Jttatei)  to  br  at 
Bi«iet  •inly  about  40  mm.  in  li^ngth  ;  hence,  in  an  ordinary  cmniraction. during 
the  gmiter  part  of  the  durutiou  of  the  contraction  the  wbolo  IflUgih  »f  the 
Gbra  will  be  occupied  liy  the  eoti tract  ion  wave.  Just  at  the  bo^nlug  of  tlie 
contraction  then-  will  be  n  time  when  the  front  of  the  contrwitiOD  wave  haa 
reached  for  instance  only  halfway  down  the  libra  leuppoting  tbe  stlmuhiG  to 
be  ap(died,  as  in  the  caae  we  have  licen  diaeuBring.  at  one  oad  only  J,  and  jiiat 
at  toe  end  of  (be  contraction  there  fill  l>e  a  lime,  fjr  instance,  when  the  »>ii- 
traelJou  hna  lell  the  half  of  the  Hhro  nest  to  theatimuUia,  but  haa  nnl  ret 
cleared  away  from  tho  other  half.  But  neartv  all  the  rest  of  the  time  every 
(lart  of  the  fibre  will  l)o  in  some  phaae  or  other  of  contraotion,  though  the 

fioriit  nearer  the  stimulus  will  be  in  more  advanced  phaae*  Ihan  the  part* 
iirlher  from  tlie  stimulus. 

This  b  true  wheu  n  muacle  of  parallel  fibras  is  ntiniulaled  artificially  at 
one  end  of  the  muscles,  and  when,  therefore,  each  libri;  i^  Htimulaiisl  at  one 
eaul.  It  ia,  of  course,  all  the  mure  true  wheu  a  muacle  of  urdluaiy  coo* 
■tnictiou  b  «timu1ate<l  by  tueaun  of  its  nerve.  Tbe  Hiululu^  of  tli«  nervouf 
inipulMr  impingM.  in  Ihia  caae,  on  the  niii:>ch'  lihn;  at  the  cnd-plat«  which,  a* 
we  have  aaid,  in  placed  toward  the  miildli.-  of  lh<-  tibrc,  and  the  contraction 
wave  traveli  from  the  end-plate  tu  opposite  direction)'  lowunt  encli  end,  and 
bw  accordingly  only  ahuui  half  the  Ivngih  of  the  librr  to  run  iu.    Ail  the 


\ 


CtlAXaRS    IN    A    MUttCLB    UL'RINO    CONTUACTION.  99 

mure  thnntot*.  must  the  whale  fibre  \»  io  a  state  of  coulractioii  at  the  wnae 
tian*. 

It  will  be  ohecn-e<l  tliat  in  whni  has  juet  beeti  said  tlie  oonlraclion  wave 
tarn  b(m  lakeD  lo  include  not  <ml>'  the  onlrnetioo  proper,  ttie  ihiokeDing 
MkI  •borteniii)t,  but  also  the  reUxnlioD  und  return  tu  the  DatuntI  form;  ibe 
Ar>l  [Hirl  of  tlie  nave  up  tu  the  suiuiuit  of  the  creel  comnKHuU  to  tb« 
■  li-'rtruitii;  nnd  itiickinio);.  the  decline  from  llie  siiiuiuit  ouirard  CorKe[Kin<k 
bi  Ihe  rvlaxaiiiin.  But  we  have  nlrendy  iDBiHUHl  that  tbe  relaxolion  is  an 
— aatial  part  of  iho  nhulc^act;  inde«(l,  in  a  certain  ^eoae,  aseaeentia)  ait  the 
•hurttnlDk:  il*cir. 

I M.  JUiiiuir  ttnitinrt  of  mutevtar  fibrt.  60  far  we  have  beeo  dealiug 
m\ilk  (b«  miiwie  a>  a  wbol«  and  ai  obM.T\'eil  with  tiie  naked  eye,  though  we 
ban  itKtdeoialljr  'IKikeD  of  fibre*.  W«  have  noo',  confining  our  Htteniiou 
csdaiiTely  to  tikcli-tal  niuw:]i.'ii.  lu  coibud«r  nhat  tiiicr«ACo|>ic  changut  lukt^ 
placv  doriDK  a  contraction,  what  arv  tbc  rulatioua  uf  Ihe  hirtulogicut  feature* 
■if  tba  muK'iv  fibre  Ui  tbe  act  of  eouumction. 

Tba  liHiK  cylindrical  fbcnth  of  snrcolomma  t*  nccupicd  by  niiiMit sub<tancc. 
AfUr  ilMkUi  lIm:  iiiiitlc  nultFinncc  may  M^pnr.ite  from  tbc  Knrcolcmnia,  U-4iving 
lb«  Wucr  as  a  distinct 'lifAlh,  liul  during  lite  iho  muscloaulwUnce  is  adhervnt 
tM  1^  iknvdrninia,  h<  that  no  line  of  iicpnnUion  belwcMi  tlit-  two  can  l>e 
■uub  oat ;  thu  niovenients  of  tin.-  one  follow  exactly  all  Ui«  movement*  of  Ibe 
other.  , 

.■<^lt-m)  in  the  rniiM.-le  snbslHDce.  but,  in  the  mamma),  lyiii^  for  the  moi>t 
pan  rfnf<^  imiU'r  iIh-  ■^nnsilt'oiDin.  are  n  nunilicr  ofniirtei,  oral  in  sha|ie.  witb 
iImi'  ites  parallel  to  the  length  of  the  fibre.     Around  each  uuclein  is 

a  ii<  1  i>f  KrMnular-Iooking  suDManee  very  similar  in  appesran<'e  t<i  that 

faraBMrUw  iKxIy  of  a  white  biood-corpn^cle,  nnd  like  that  oftCD  spoken  of 
as  tnuAnnilaiod  prolophiain.  A  shmII  i|imiitity  of  cite  hbdm  stmnular  imb- 
Ksam  u  pml'iuji^il  fur  iMime  ilixtniicc  lU  a  narrow  coui<'jil  Mreak  from  oach 
ta\  of  ih>?  noclcii*.  alon^f  the  lcn;j;th  of  the  fibrv. 

With  the  csixplion  of  tbtM  nuclei  with  tW-ir  grauulnr  looking  bol  and 
4*  end -plate  ••r  i;nd-nlalc8.  toW  precvntlv  dvccrilx^,  all  thereat  ortbe»|iaG« 
tpfliwail  by  iIk-  snrculetnma  fiMU  on«  en<f  of  (he  (ibrc  to  lliv  other  apficara  to 
b  eompinl  bv  u  {Hvuliar  rnnlerial,  lirialtd  muWr  /mtulaiiec. 

It  m  cnlluJ  Hrialett  hccaiife  it  is  marknl  out,  ami  that  along  tlio  whole 
laqph  of  Ihe  Sbrv,  by  transvene  liandc  [Pig.  3:!],  stretchiiig  right  acrom  the 

[Plu  XL 


s 


Di«i«t.icNjiTR  RxraaoT^raw  or  jt  Hcaoia^uR. 
■Mil— 1« f rlwii,  BB«<Wli<of>l>«»»*li"<*'M«l»roJi!  tfc  Anld «Wuw«.I 

ftiV,  nf  aubMance  which  is  very  Irait^parenl,  hriyhl  »abiUiHef,  altcmaling 
•itb  Mrailar  bands  of  substance  which  has  a  dim  cloudy  appearnncv,  dim 
aiMcnw;  llial  b  to  any  the  6bre  ia  marked  out  alonp^  iu  Wliole  length  by 
ttUnMn  brifhl  baml*  and  'lim  h'lndt.  Tlie  briglil  bands  are  on  an  average 
about  \  por  !■•>  »  and  the  dini  bands  about  2.6  «  or  ^i  •>  thick.  Bv  care- 
hi  toattiiam,  both  bright  bandi  ami  dim  b«niis  may  be  traoed  tlirough 
tha  wkJa  laickiMM  of  tin:  fibre,  .io  (hat  the  wrbolo  fibre  appears  to  be  com- 
pMd  of  bdskt  disc*  muI  dim  Aae*  placed  alternately  one  upon  ihe  other 
ala^  i1m  whole  length  of  tlie  fibrv,  tbc  amingGiuent  being  brviken  by  ilie 


I  i    -ON  rRACTII.E    TISSUES. 

•  'k «kw>iti   '(l)iv  »  trvaled  with  dilute  mineral  acids  it  a  very  apt 

.    ,.  ..|-  iMu.ic>n(;I>  iucvdiiM-s  [Fig. 3'2],  the  sarcolemma  being  diaaolvM, 

■  ■iv.Mi   ■&  juruiv  c\>  divide  into  fragments  corresponding  to  the  dines ; 

.    :r4    ud,_<>  .iiiiR.  b<  obtxinet]  ao  thin  as  to  comprise  oaly  a  single  dim  or 

■  „.:.    >H.iM,  'i-tJiru  twuu)  with  a  thin  layer  of  bright  substance  above  aod 

\    ■..     I,    ,\m  •■iiMtHipf  having  taicen  place  along  the  middle  of  the  bright 

«t  'K->  '«uKt\.>i  «iih  tvrtain  reagents,  alcohol,  chromic  acid,  etc.,  the  fibre 

■  >,.<  if'.  I"  ^'U\.  M)*  i.aiid  the  splitting  up  may  be  assisted  by  "  teasing") 
-. .„.!•.. iiiiikl.k  luivi  ivliiiuits  of  variable  thickness,  some  of  which  however 
..-v  v  vv4\luij;ly  thin,  and  are  then  sometimes  spoken  of  as  "  fibrillK." 
n.lt  .iv'H'  ^(ini.'ti  Hiid  tibritlte  are  artificial  products,  the  results  of  a  trans- 
...^  >i  k-u^itkidinal  cleavage  of  the  dead,  hardened,  or  otherwise  prepared 
u.i-Aiv  lutvitMUtv.  'I'hev  may  moreover  be  obtained  in  almost  any  tbicknea 
1  i-iiiiiuvw.  Aitd  thvw  tliscs  and  fibrillfe  do  not  by  themselves  prove  much 
>,  >>gi.t  iht-  iWt  thai  t\w  libre  tends  to  cleave  in  the  two  directions. 

Ihv  lis  Ills  lilirt>  hiiwfver,  though  at  times  quite  glassy  looking,  the  bright 
\.>i.U  ft|>t«-Mi'i»K  likti  trans^tarent  glass  and  the  dim  bands  like  ground  glass, 
'•  ti  othvi  iiim*>  marked  with  longitudinal  lines  giving  rise  to  a  longitudinal 
..•i.tti^'ii.  H<u»>l iiiim  iHiDspicuous  and  occasionally'  obscuring  the  transverse 
A'MLUti  III  lht<  iiuim'Im  of  some  insects  each  dim  band  has  a  distinct  p&li> 
..t.'v'  •t|>)>t>HiMii<H>  an  if  made  up  of  a  number  ot  "  fibrille  "  or  "  rods  "  placed 
.i>lv  t>t  ■»!>'  ami  iiiibtilded  in  some  material  of  a  different  nature ;  moreover 
>k.H'  iDiiillii'  or  nidd  may,  with  greater  difficulty,  be  traced  through  the 
ixi^Ki  bit  I  >d  4,  and  lliitt  at  times  along  the  whole  length  of  the  fibre.  And 
ili.'U'  ii  H  ijivat  dt-al  of  evidence,  into  which  we  cannot  enter  here,  which 
i^oix  li>  I'li'Vt'  lliitl  in  alt  striated  muscle,  mammalian  muscle  included,  the 
iiiMv  U<  iiitwtHiiiv  \»  nmlly  composed  of  longitudinally  placed  natural ^ArtVAs 
.'I  n  iviiaiii  iiHlum,  imtVddeil  in  an  interfibrillar  suDstance  of  a  ditferait 
ii.tititv  III  iiiiiiuniHlian  nuisoloand  vertebrate  muscle  generally  these  fibril  lie 
iiu  iMiviiingly  tiiiii  and  in  most  cases  are  not  sharply  defined  by  optical 
ilniitu'tKia  iVotii  ihi'ir  intertibrillar  bed;  in  insect  muscles  and  some  other 
iiiiiti  \vm  ihcv  am  rt-lalivt'ly  large,  well  defined,  and  conspicuous.  The  artifi- 
k'Kil  iiliitll(*<  uliliiini'il  bv  iciwiiig  may  perhaps  in  some  cases  where  they  are 
I  \i>'i'iliii>tly  iliin  I'lun'HiMind  to  these  natural  fibrillse,  but  in  the  majority  of 
uiii'H  ihov  t'ci'tidnly  di>  not. 

Ill  it'i'liiiii  iiiaiH-l  iiinMcUi<  each  bright  band  has  in  it  two  (or  sometimes 
iiiuiio  iliiik  liiiM  which  are  granular  in  appearance  and  may  be  resolved  by 
.idi'>|iiiiiii  iiiiignitViiig  (HiwiT  into  rows  of  granules.  Since  they  may  bv  focQs- 
ui;'  lii>  liiii'i'd  lliviuigh  tl)e  whole  thickness  of  the  fibre  the  lines  are  the 
I  t)iii'si)iiiii  i>r  liiiH'H.  l''rfi|U('i)tly  the  tinea  in  the  bright  bands  are  bo  conepic- 
ilkU'  111  li'  riinii'iliuti<  a  givaler  share  to  the  transverse  striation  of  the  fiore 
lliiiii  iln  lilt'  dim  IiiiiiiIh.  Similar  granular  lines  (rows  or  rather  discs  of 
Kiiuiuli>.->i  uiiiy  uiiio  bo  Hccii,  though  less  distinctly,  in  vertebrate,  including 
iiiiiiiiiiiidiiiii,  iiiiiHi'li'. 

Il<niili<ii  iliiviK  griiniitnr  liiici>  whose  position  in  the  bright  band  is  near  to 
I  ill  I  Inn  liaiiili,  nHcn  tipjicnriiig  to  form,  as  it  were,  the  upper  edge  of  the  dim 
l-iiiiil  liiliiH  iiiid  tlm  lowiT  cilgc  of  the  dim  band  above,  there  may  be  also 
n..iii,ununlrHfrd  aunt  her  Iransverae  thin  line  in  the  very  middle  of  the  bright 
luiiid.  'I'hix  lint',  like  Ihit  other  lines  (or  bands),  is  the  expression  of  a  disc 
and  liiiB  liiTii  ludd  by  wmw  observers  to  represent  a  membrane  stretched 
iiii.i-w  lim  nliiili>  ihickncHii  of  the  fibre  and  adherent  at  the  circumference 
Hilli  llm  BHiriilniiiiiii ;  ill  this  sense  it  is  spoken  of  as  Krame'i  nwinbraiie. 
Till'  iriiMuiiB  I'm  Inlioving  that  the  line  really  represents  a  definite  membrane 


I 


I 


tM>t  however  ap(i«ar  to  he  adeiiiiate. 
metliiitc  line." 

Wli«n  ■  itiiii  trniuvftrM  secUon  of  frnxcii  muM'lc  n  cxaminetl  quile  IVo>U 
Hod'T  u  tii^h  pi>w(!r,  tlin  iini.-u-lf  Kutuiniici- within  the  Huvoltoima  ia  wcu  tp 
ba  niurlcil  oul  into  n  uutulxr '>f  umiill  motv  or  lew  polygon nl  Area*.  AD d  it 
aitDilar  nmtiif(<:nH-nt  iuto  nntu  miiy  al«i>  bo  Mwn  in  tmitsvunM.-  xn^tion*  of 
prefwrad  inuNcIc,  though  lh<-  iVtiturrs  of  the  nrcif  orp  somcnhat  liillvrout 
from  thorn  mod  in  thoi  fmli  living  libre.  Thcw  areas  are  B|x>ki>a  of  M 
"  Cohnheim'fl  nrfm* ;"  they  ano  vcn-  much  larg«i:  than  the  dinawtcr  of  a 
RKrilla  as  iodicatMl  bv  t}i«  ioniiituiUDal  etrialion,  and  indoed  corrupond  to 
a  whole  hundle  of  suoh  tibrilla>.  Their  exwlence  teeaa  to  iodicnte  tnat  the 
ftbriUje  are  arrao^'ed  in  lort);itiiilinal  prisiiia  separated  from  each  oliter  hr  a 
larser  nniount  of  iiiterhbrillar  subitaiice  than  tbtU  uniting  to^'ether  the  tndi- 
ridual  libriliw  formin};  each  priam. 

LiMtiy  i(  way  be  mentiun«(l  that  not  only  are  the  various  Kranular  linet 
»1  times  visible  with  diliiculiv  or  iiuite  invbible.  but  that  even  the  diAtino- 
tinn  belReeu  dim  and  bright  band»  in  uccAsii>iinily  very  faint  or  olwcure,  the 
whoh-  muiii:i<^  »u balance.  n|>art  from  the  iiudei. apftearing  almoet  huiuoKetieouk, 

Withuui  attemi>tinx  to  diwuw  the  many  and  varioui  inlerpretatioiia  of  ihu 
■Imvv  flixl  ithtir  lUtaila  conoerninfc  the  minute  vtmctiire  of  striated  musctilar 
(ibr(>.  n<>  may  here  oiHilvfit  outsvlvM  with  the  following  general  conclusion*: 

(1,1  That  ihv  am»ch  ituliKtiuicc  i*  t^ompiMed  of  longitudinally  di«po«ed 
Jibriltir  I  priilNttily  (■ylindricat  in  general  form  an<l  itrolMbly  arrangcil  in 
h>OK>ludinn)  pri'inii)  rm)>r(td<)d  in  an  inlrrfi/irlllar  notiaaee,  whi<'h  ap|H-iir« 
111  Fh-  Inw  ililWentiatfil  thiin  th^t  lihriltic  ihemaclvci  and  which  i«  probably 
cfintinuoita  with  the  undiircreii[>at«<t  protoplmm  round  tin-  nuclei.  Thv 
iiitcrtibriUnr  fubrtaooe  etains  morv  raidily  with  n^ld  rhloridv  than  do  the 
fibriliir,  and  hrnce  in  gotd  chloride  epodmcM  appear  a*  a  rort  of  mcsliaork, 
wilb  hingitudinal  i-paoet^  correHpondlng  to  th«  fihrillffi. 

(2i  That  the  inierlibrillar  Bubolancc  w,  relatively  to  tlie  fihrilljB,  more 
abuntlaoi  in  the  musclei  of  some  animale  than  iu  thow  of  others,  heiug  for 
instaiioe  very  roiispicuoua  in  lli«  nitiHcles  of  insects,  in  whicii  animals  we 
■bnuld  naturally  expect  the  leas  ditferentiaied  material  to  be  more  plentiful 
than  til  the  muscles  of  the  more  highly  developed  mammal. 

('■H  That  ihe  Gbrillie  and  interSbrillar  substance  baviuK  dilferent  refcac* 
live  jHiwerv,  some  of  the  optical  featurea  of  muscle  may  t>e  due.  on  the  one 
haira  til  the  relative  proportion  of  tibHII»  to  incerfihrillar  «ubsiance,  and  on 
tlie  other  IuuhI  to  tine  librillie  not  beint:  cylindrical  throujthout  the  length 
nf  tin'  tilire  hut  contitHcted  at  intcnaU,  and  thus  l>ecoming  headed  or 
OKMiditortu  ;  for  iiwtancifl  the  roiva  of  granules  xi><>kuii  ufabovi-  arc  by  lunnc 
rtpu-<lrd  111  carrM|H>»ilini[  to  aggregation*  of  mtertibrillar  maliTial  lilliiig 
lip  the  r|iar>-«  where  ihr  fihrilhe  arc  nu«l  coitttrinted.  But  it  dow  not  Mem 
pLMihln  at  the  prTMenl  time  to  make  any  ftalenivnt  which  nill  mtbfoctorily 
explain  all  lb«  varioUN  appoaraiicew  met  with. 

t  AB.  We  may  now  rettim  to  the  •lutvlion.  What  happen*  when  a  conlruc- 
lioD  wnv  Nwiyip*  over  Ihe  fibre? 

MuMTular  fibre*  may  be  examined  oven  un<ler  high  power*  of  the  raicro- 
«CQp«  while  they  are  yet  living  and  contractile:  the  oonlraclion  tiself  may 
U  (cen,  biit  the  rate  at  which  the  wave  travels  u  too  rapid  to  [>crmit  Katis- 
faclury  observations  being  made  a§  to  the  minute  changix'  which  accompany 
cotilraclton.  It  fre<jueiitly  happens  however  that  when  living  muBCle 
l>cen  treated  with  certain  reagents,  as  for  instance  with  otimic  aeid  vupor, 
•ubpe<]i>ently  prepareil  for  examination,  fibres  are  found  in  which  a 
ig,  a  tbickeniitit  and  shortetiing,  over  a  greater  or  leee  part  of  the  length 


i 


THE  COKTBACTILE   TI890E3. 


of  the  Abre,  has  been  Bxed  by  ihe  oemtc  acM  or  olber  iVAgeiit.  Such  b 
bulginK  ubvioiuly  difl^ra  ttom  a  normal  ountrectioti  in  being  conffoeil  to  a 
pnrt  ov  Ihe  lotifili  of  ilie  fibre,  v.')i«rea«,  aa  we  ha\-(-  nuiil,  a  normal  wavo  of 
contrutioD,  btiDg  v«ry  inii<^)i  longer  ibaii  any  fibre,  •>ccur>iM  t)i«  uIkiIc 
loi^t4i  of  tbe  fibrfl  at  once.  W«  mar  Iiuwrvcr  n-)^nl  lhi«  bulgtiii;  w  a  vi-n- 
slwit.  a  very  abbr«viiit<<(l  wnv<-  »f  riiotriK-rion,  unil  nwuine  lb»i  th«'  t'lian^ 
visiblo  in  sucb  a  short  bulging  iiU»  tiiki.-  jilitcv  in  n  normal  contmciioii. 

Admitting  ibis  avuinpUon.  wc  learn  fr»m  siicb  prepanttions  tbal  in  the 
cunlrnciing  region  of  the  fibre,  while  lioth  dim  nnd  bright  banda  become 
braaderncroea  lh«  fibr«,  nnd  correspondingly  thinner  nlong  tlw  Icnglh  of  tbe 
fibre,  B  remarkable  change  takee  place  hetwe«n  the  dim  bands,  brignt  haDda, 
and  granular  lin««.  We  have  seen  ibat  in  Ihe  fibre  at  rest  the  inter  mediate 
line  in  ibe  bright  baud  t<  in  moM  casea  iucuDspicuoui ;  in  tlie  contracting 
fibre,  on  (h«  contrary,  a  dark  lin«  in  the  middle  of  the  bright  band  in  tbe 
ptieiiioD  of  the  intermediate  line  becomee  very  distinct.  As  we  ]mum  along 
tbe  libre  Irom  (be  beginning  of  tbe  coiitrartion  wave  (o  the  summit  of  the 
wave,  where  the  thickening  ia  great4»t,  thi>t  line  beooinftt  more  ami  more 
•tri king,  until  at  the  height  of  the  contrai'tion  it  beoomes  a  rerv  marked 
dark  line  or  thin  itnrk  band.  Pari  fintm  with  thid  changr,  th<r  diMinctioo 
between  t)iv  dim  nn'l  bri;;lil  liiuiiln  become  leHs  and  Irm  Jiiarked  ;  thne 
aitjuMir  to  bcoi>mc  ciinfii#c<l  Ingiaher,  until  nt  th<;  hi^ight  of  the  oontraclioR, 
the  whole  space  between  esich  tivo  now  cnnxpiciioti''  dark  linw  is  occupied  by 
a  •iib<4nnc«  which  can  be  called  neither  dim  nor  bright,  but  which  m  con- 
triMt  to  the  dark  line  apjHtars  more  or  hw  bright  and  transparent.  So  thai 
in  lll«  contracting  part  there  is,  at  the  height  of  the  contraction,  n  rev^ntal 
of  the  state  of  things  proper  to  the  part  at  rest.  The  place  occupietl  bv  Tlif 
bright  baud,  in  the  state  of  rest,  is  now  largely  tilled  by  a  conspicuoiiH  dark 
line  which  previously  was  represented  by  llw  inconspicuous  mlermediale 
line,  and  the  place  occtipiiii  by  the  eon^picuous  dim  band  of  the  llbre  at  roM 
now  Mcm*  bv  ooinpnriMon  with  the  dark  line  tbe  brighter  pan  of  iIk-  fibre. 
Th«  contracting  fibre  ts,  like  tbe  fibre  at  reit,  striated,  but  its  striaiion  is  dif> 
Ibrent  in  icii  natur«  fr^xn  the  natural  striaiion  of  tlte  railing  fibre ;  and  it  is 
hdd  bv  wHue  that  in  the  earlier  phii»i=«  of  the  contraction,  white  the  old  natu- 
ral itruition  is  being  replaced  by  the  new  uriation,  there  m  a  alagv  in  wbldi 
all  striaiion  is  lest. 

We  may  add  that  the  outline  of  the  sarcolcm ma,  which  in  the  fibre  at  rest 
is  quite  even,  becomes  during  the  contraction  indented  opposite  the  interme- 
diate line,  and  bulges  out  in  the  interval  l^tween  flach  two  ioteroiedbita 
lines,  the  bulging  and  indentation  becoming  more  narked  the  gmUr  tb* 
con  tract  ion. 

§  96.  We  can  learn  something  further  about  this  remarkable  cbangn  by 
examining  the  fibre  under  polariiHMl  light. 

Wli«ii  urdinary  light  U  aetil  tliruu^h  h  XIcoI  prism  (which  is  a  rhoinb  i>r  [ne- 
laud  «psr  divided  Inlo  two  in  a  cerlflin  directloa,  the  faalrei  being  Mib»i>i)ueriily 
oemeated  U^thor  Jn  a  special  way)  it  undergoes  a  ebange  la  jMsaing  through  tbe 
prism  and  is  said  to  bo  polarhrH.  One  e(^t  of  this  |>oUriallon  ia  that  a  ray 
of  light  which  bus  pn»ed  through  one  Nicol  prism  will  or  will  not  pMS  tfaroucb  a 
semoil  Nicol  Hcconllng  to  the  ri-lallv«'  jiusltion  of  thu  (»<•  iinKinn.  Than,  if  the 
second  Nicol  be  so  placed  that  what  i«  cnl1c<!  ii«  ''  optic  ai'is  '  b«  in  a  line  with  or 
psrallel  to  the  optic  nxii' of  the  Hnt  Nicol  the  light  passing  through  the  II rot  Nlcul 
will  also  (MUD  through  tbe  Kccond.  Etui  if  ihc  second  Nicol  W  roMl«d  until  its 
<^e  axb  ia  at  right  angles  with  tbe  optic  axis  or  the  fint  Nicol  wiat  of  tii«  light 
]>aMlRglhruugbthefom>erwillpaMthrough  the  latter;  iheprisuis  in  this  posliioo 
ar«  ssld  to  be  "  crossed,"  In  intermediate  posilioDs  more  or  Ic-m  light  paaiiea 
ihriugb  the  sccoixt  Nicol  according  to  tbe  nngle  bsfweon  the  two  optic  nxm. 

ileiHM)  when  one  Nicol  is  placed  beiwath  the  stage  of  a  microMOpe  mi  tlmt  tbe 


k 


U  Irom  th^  mirnif  in  t^iit  tliroui'li  it.  hiiJ  aiintlier  Ntcol  is  plitoed  in  tli«  «y«- 
,  r«.  tlir  tiriil  of  Ihi-  inii;m(ico(i«i  i*ill  ap)i««r  ilnrb  «b«n  th«  ey^-pieee  Niool  ia 
nitktfld  »•>  tliHi  iu  optic  iixia  i«  kt  Hghl  Anglm  to  the  i>|tlic  ftxii  of  thr  lower  Xicol, 
Mi'l  coiM«<iuent1y  tht?  light  pawing  throusii  (ho  l<iw«r  Nicol  in  •Ii>|i|)e<l  by  it.  ir, 
buwrvrr.  tli«  "plic  axi"  <if  the  t'_v<'-ii!ccc  Nico]  iH  piirallfrl  toikuturilie  tower  Nicol. 
ilio  liichl  from  thr  Intirr  will  [.ftKi  ihrouEh  the  hnaet  am)  the  Held  will  be  bright: 
lUKlaa  tbvcTv-piMie  m  srMluntty  roiaief  fVoiit  oiiepmition  tn  theolkM  tb«  brlgbt< 
ncM  of  ilie  i!l«)d  will  tlunioioh  nr  increMe. 

Botli  ilie  Niool«  ar*  «>RipoMHl  of  ihiubly  rofrnctlve  niuterinl.  If  now  a  ihlrd 
iImiIi])-  trfrHciive  aial«ri«t  lie  pUcoil  mi  Ibe  vtuge.  aiitl  tlierefore  between  ihe  two 
Nirol*.  [he  liicht  pMai up  through  ihe  loirer  Nicol  will  (in  a  certain  poaitiixi  «f  the 
ilonbly  refriLiivc  mntenal  on  the  xtaee,  that  is  to  aay.  whcii  itn  optic  *xm  hava  a 
i-rnain  r'niiion}  paai  ihningh  it,  ana  alxi  through  the  rrairej  Nieol  iu  the  eye- 
(liece.  ilencc  tbe  doubly  refraclivr  mntrrial  on  the  Hlage  (or  -tioh  [iflrtH  of  It  aa 
ar>'  i"  ff'i-  irfnper  poaition  in  rwjiew  to  iheir  oplic  axw)  will,  when  the  eye-piece 
Ni  -ed.  nmiMf  llliiiuinale']  ami  bright  on  a  ilnrk  field.      In  thin  way  the 

et  I  -  I  iluubl;  ivfraeiire  malorial  in  a  prepiuatiiiii  may  be  iletcclvd. 

When  tnu»cle  [ireparecl  nnd  n>04int«<)  En  Catioiia  bttlaum  u  exatained  in 
th«  microecupt!  Iwtweeii  Nioo)  jinanii'.  oik  uii  tbe  vUiK^  helow  lh«  •.ibjoul,  and 
tbe  (itber  iu  the  i'v(:-|>i«<x-,  t])«  Hbrm  stand  unl  iw  bnght  objvctn  on  Ibi;  <lHrk 
DDtl  of  III*'  li<^ld  when  llut  axes  of  tbe  |>riKtna  nn;  cnNwed.  On  cUmrf 
linatioa  it  L«  nvco  that  the  parts  whieh  iin-  )>n^lil  urv  chi«flj  thv  dim 
m.  Thia  Indii-nlea  that  it  is  the  dim  iMiidit  which  arc  dmibly  n-frH«tivc, 
iMtrfrD/fM-,  or  an-  ehii-fiT  made  up  of  anisotropic  subatnnce;  tluire  sc«rii». 
eter,  to  be  iu>nie  slight  nmouQt  of  nniaotropic  subaUan  in  tbe  bright 
ada,  thiiueb  thot:  lis  a  whole  appear  single  refntelivo  or  itolropic.  The 
tibn  iceonliDKly  apjwars  banded  or  rtrialod  with  alternate  bnnds  of  nniao- 
tnipic  noi)  iaotropie  materia).  According  to  most  auihore  such  nn  alterna- 
tiiiD  (if  anisotropic  and  (chiefly)  iaotropic  bands  which  is  obvious  in  a  dead 
■mi  preiMred  fibre  exists  also  in  ihe  living  fibre ;  but  some  maintain  thai  the 
iviOK  filire  in  uniformly  aubotr<ipie. 

~~"ow,  when  a  fibre  raulracta,in  »])iteol"the  confunion  preriAiMlj  mentioned 
reodini  and  bri^hi  Iwodx,  there  i»  no  eouftiKiou  between  liie  anisotnipio 
nd  iantrapic  materia).  The  ani»otr»iiie.  duubly  refmetive  bands,  bright 
under  crm»ed  Nicxtli,  tMieuprin):  tlie  poititiou  of  the  dim  ban<ta  in  tbe  resting 
Rbrr,  remain  iloul))}'  refract ive.liright  tindiTr  croiaed  Nicu)s,  ev«D  at  the  very 
of  the  eontmclioii.  Th«isotr<i|>ic.  Kiiigly  refractive  )>andi'.  darlc  under 
'  Nicolii,  iKiciipyiiig  thft  pavition  of  the  l>riu;hl  bandi>  in  the  fibre  at  rest, 
iaotropic  and  dark  uiiderenj*«i^l  NicoU  ni  tlie  very  height  of  the 
txHUradlon.  A)l  tliiit  cnn  )>vMen  is  that  the  singly  refruciiveisotro)tic  btinda 
bevome  ver^-  thin  indeed  during  Ihe  cu  lit  mot  ion,  while  the  nni»oln)pic  tiandM, 
tbough  of  contw  becoming  thinner  mid  bronder  in  the  coutriKriion,  ilo  not 
mc-  so  thin  U  do  the  i<<>tropic  bands :  in  other  vrontf,  while  liolh  )>ikuiU 
me  ihinDvr  and  broader,  tne  donbty  refractive  iini>^olr(ipic  band  si,-«nis 
norcMse  at  tbe  expense  of  the  singly  refractive  isi^ronic  liitnd. 
$  07.  We  ea)l  attention  to  these  tads  because  they  »how  him-  complex  ifl 
the  a<-t  «f  contraction.  The  mere  broadening  and  shortening  of  i-aeh  seetton 
of  ihv  fibre  is  at  bollom,  a  translocation  of  the  molecules  of  the  muscle  siih< 
tUQon.  If  we  imagine  a  company  of  100  soldiers  ten  nuiks  deU|>,  with  ten 
mHi  b  Meli  rank,  rapidly,  but  by  a  series  of  grnilutions.  to  ext«n(l  out  into 
a  diinble  line  with  oO  men  in  each  line,  we  ^hall  have  a  rouffh  image  of  tho 
iBDV^mcnl  iif  the  nmleeulea  during  a  muscular  coiitrvdion.  But,  from  what 
Ilia  tiM-n  Milil.  it  is  obvioun  Ihni  the  movement,  in  striateil  mnsele  at  least,  is 
a  very  nimplicntMt  on<> ;  in  uilii^r  forms  of  contractile  tiMiie  it  may  be,  as  we 
■ball  «<•,  more  "imple.  Why  the  movement  ii  so  complicated  in  striated 
nu*clv,  wbal  purpumi  it  eerven,  why  the  nkek-ul  musetn*  are  titrialed,  we  do 


toll: 


THB  OONTBACTITiB 

ont  *t  |»mcni  kimw.  A|i|Mir«Dtlv  wlu^rc  Nwift  and  nii>id  oontnifiiitii  it 
requintl  iho  coiitraciili-  iiMtio  in  Mnutol  inuMtk ;  but  how  Ute  Mriatioii  hvlim. 
•0  to  )t|K9ik,  th<:  ciiiil  tiirltiiu  vri-  <)<>  not  kniiw.  We  l'hiiikiL  nay  vrhnt  Khiiro  in 
lh«  net  of  coDtrnctivn  i.*  t»  bo  ttlliaCol  U>  lh«  ocvrrul  juarta.  .Sincr.  during 
K  cuuUmi^ion,  the  fibro  hkilgaw  out  awrv  0|>|x)»it«  to  cficli  dim  di>c.  nnd 
\b  indented  opposite  to  c«ck  bright  disc,  «inc«  tliv  ilini  di>c  i«  mora  largely 
(vxDpoced  of  anisotropic  mau-rial  than  the  rwt  of  tbo  fibre,  and  siooe  Uk 
anisotropic  nutl«rtnl  in  the  |x>sition  of  the  dim  disc  iiicmiMa'  <liiring  a  cod- 
triK-iiou.  nc  might  porhajw  infer  tUiit  the  dim  disc  mthor  than  tlic  brij^bt 
disc  is  lh«  eneDtially  active  rmrt.  Awiimini^  thiit  lh«  fibrillar  substaDcc  is 
more  abundaut  in  tlie  dim  discs,  while  the  micrlihrillar  substance  ta  more 
abundant  iu  th«  bright  discs,  and  that  the  fibrillar  substance  is  anisotropic 
(and  hence  ilie  dim  discs  larKcIv  nuUotrupic),  while  th«  inicilibritlar  sub- 
stance  is  isotropio,  ne  mifht  also  be  inclined  to  iufer  it  is  the  6brillar  and 
nol  (be  iuterfibrillar  subetauoe  which  reallir  carries  out  the  coutractiou ;  but 
even  tliia  much  iu  ni>t  yet  definitely  jiroved. 

One  tliiu^  mujit  !>«  remembered.  The  muscle  substance,  though  it  p<j»- 
»vsii-i  the  ouiujiliculed  ttnicture,  and  t^M  through  the  remarkabUr  channi 
whirh  We  have  <lt-»cnb«l,  \a  while  it  h  uviag  and  intact  in  a  condition  which 
wc  are  dnvc.ii  to  t\teak  of  ux  nemi-Htiid.  Tlie  whole  of  itU  ewcnliiilly  miJtlle. 
T)u>  very  act  of  coutmi-liiui  indin-d  nhowsthb;  but  it  in  nmttik  in  the  sciisic  that 
no  part  of  it,  except  of  counw  the  nuclei  ami  itarccilcmma,  neither  dim  nor 
l>rif(ht  futwtanee,  neither  fibrillar  nor  iut«rfibrillur  nulMiaiicv.  «ui  tw  regarded 
a*  a  hard  nnd  fimt  structure.  A  minute  ueniatoid  wonn  has  been  scon  wan- 
<lvnng  in  the  nmlst  of  tlie  substance  of  n  living  contrnctiletibrc:  wi  it  moved 
along,  tlvo  muscle  stibelanec  gave  way  iH-fore  it,  ami  closed  upii«ain  bebiud  it, 
dim  band)' and  bright  bauds  all  falling  back  into  their  proper  pMuva.  We  may 
suppoM  that  in  this  case  the  norm  Itircnded  its  way  in  a  lluid  intertibrillar 
suoshioce  between  and  anmiig  highly  extensible  and  clastic  6bri)l(e.  But 
even  on  auch  a  view,  and  .ilill  more  on  liie  view  that  the  tibrillar  aub^tance 
also  U'u  broken  and  clooecl  u»  agwn,  (he  maintenance  ot  such  definite  hii<to- 
Iflgical  fbatures  oa  (hoee  whicn  we  have  deeeribed  in  malarial  ao  mobile  can 
Mily  be  eflibcted,  even  in  the  Hbre  at  reel,  at  some  conudenible  exiwodttitre 
ofener^:  which  energy  it  may  be  expected  hasa  cJieniical  muroe.  During 
the  contraction  tliciv  ia  a  Mill  ftirtber  expenditure  of  ejier(,'y,  mm*>  of  which, 
as  we  have  seen,  may  l«avo  the  muacle  aa  *'  work  dune ;"  thh  energy-,  lik^ 
wise,  may  Im*  cxpeclc<l  to  have  a  chemical  aouroe.  We  miisi,  tbcivfore.  now 
luni  to  the  cliumistry  of  miiade. 

T/if  Cftmintry  0/  Mwrft. 

$  98.  We  said  in  the  Introduction  that  it  was  difficult  to  make  out  with 
certainty  the  exact  chemical  ditferencee  between  dead  and  living  nub- 
ittance.  Muscle,  however,  in  dying  undergoes  a  remarkable  ebemical  change, 
uliii-h  may  be  studied  with  comiiaratire  ease.  We  have  alrvatly  niA  that 
all  miucl»,  within  a  certain  time  aAer  removal  from  th«  body,  or.  if  still 
n'nniining  jiarl  of  tlie  boily,  within  a  certain  time  after  "geocral"  death  of 
lh«'  Wly,  l«*e  their  irrituhiliiy,  and  that  the  lose  of  irritability,  which,  even 
when  rapid,  t«  gradual,  in  {•uccedlcl  by  an  event  which  io  Mmcwhat  more 
sodden,  vir_,  ihv  entrance  into  tho  condition  known  as  riyor  inorlU.  The 
oocurreiice  of  rigor  mortis,  or  cadaveric  rigidity,  lu  it  is  sometimes  caiile<d, 
which  may  be  ci>i)«idercd  im  the  token  of  tbo  death  of  the  muscle,  is  marked 
by  the  following  features:  The  living  muscle  pooaassas  a  certain  Iranslucency. 
the  rigid  muscle  n  distinctly  more  opaque.  The  living  muscle  is  very  exten- 
sible and  elastic,  it  siretchee  readily  and  to  a  oooaiaerabto  esleni  when  a 


VBTeDsUnT    The  entrance  into  rigor  nortb  », 

'  ft  dtoneniug  or  coiitractiuu,  which  inaj, un<ter  oe: 

liderable.    The  energv  of  thU  (vintractinu  In  t»n  ^rent,  fu>  tlint  any 
iboricaingiseui)y|)rt!veui«(l  by  the  |irt!Miiii.-vi>l'eTeiiui'li^ht  ^pjiwing 


the  cWuiral  fviiluKu  of  th«  t\md  r^id  inuwlc  art  idso  Mrikiiigly  dif' 
rotii  ihm^  «>'  thn  living  tuiiiKitv. 

^n  lifid  miijWi-,  fnim  which  itll  flit,  uihIod.  fnsciH,  and  oonoectivo 
He  btruiu  much  lu  (xi^ihio  n^niovm).  <>i)d  which  hiu  bMfi  Awod  from 
^ho  iiijrctiuii  of  "  normnl "  siiline  solution,  be  ini»M-<l  nnd  n-])aitcdlT 

with  wntcr,  the  wnshin^  will  coiiuiD  corlaiii  furnis  of  nUiiiiiiiii  nnd 
«xlniclit'«  IxMJies.of  which  ««■  sbsll  apoalt  directly,  Wtieii  ihe  wiish- 
■  been  continue'l  uniil  the  wesb>waier  Kires  no  proteid  reaction,  a 
IWtion  of  muscle  will  Mill  remain  nudiaeolved.  If  (IiiB  be  trenled  with 
roenl.  Aoluiion  uf  a  neutral  saH,  aminonium  chlonde  betiiK  'be  heal, 

portion  of  it  will  Itecome  dissolved ;  llie  mduiion.  liowever.  la  iDOre  or 
perfect  and  5Iten  with  dilficulty.  If  the  filtrate  be  alloired  to  fall 
y  dn>]>  into  a  Isr^rc  ijuauiitv  t>f  ilintillnl  witter,  a  while  flucculeiit 
will  be  {irecipilat*^!.  Tlii.i  ifoivuleni  prvcifiitale  ia  myiMiii.  MyoaJn 
KrH),  (living  the  oritinnry  jioiU'id  ri-itctionn.  un<l  haviii^  the  turne  geU' 
liunttnry  <'>itN|<naili(in  mi  other  pr<>tci<li>.  Il  in  ixilulilio  in  dilute  MiliDft 
m,  aqHioiallv  IbixK  of  ammouiuni  chloride,  and  niav'  Im  i:1bm>c-<1  in  (he 
I  fiiinily,  cltmigh  i(  is  not  so  soluble  as  {laraglouulin,  requiring  a 
r  mtuUitii  of  a  neutral  •all  to  diiaolve  it ;  (htis.  while  soluble  in  a  A 
nr  n>tH.  soluti^m  of  such  a  sail,  it  is  far  leas  soluble  in  a  1  per  mnt. 
I,  which,  ns  we  have  seen,  readily  dissolves  parsglobulin.  From  its 
IS  in  ueuintl  saline  solution   it  is  precipitated  by  saturatioD  with  n 

snlt,   jtreferably  sodium  chloride,   and  may  be  purified   by  being 

with  a  saturated  solution,  dt»olved  a^cain  in  a  weaker  solution,  and 
jitaied  by  saturBtion.  Dinotved  in  saline  solutions  it  readily  cua^;- 
wtteti   heate<t — i.e,,  U  couvert^sl  into  eoajjulaled  proteid — and  it  is 

■if  tiotiee  (bat  it  coafculute?  ai  a  comparatively  low  temperature,  vi^., 
6°  C. ;  thiM  it  will  Im  remembered  is  ihe  temperature  at  which  Hbrin- 

congulnletl,  wliere**  pwraglnbulin,  senim-albumin.  and  many  otber 
I  dii  not  (VM^iliite  until  a  higher  tcm|H-rHture,  7'>°  C,  i^  reached, 

aiif  inyiMin  are  |ire(!i|iilat4.-<l  by  alcotiol,  and  the  tireclpitate,  an  In  the 
|ker  ^rolvidi.  bocooMi.  by  continuv«l  action  of  the  alcohol,  altered 


88  THE   COXTBACTILE    TISSUES. 

state.  And  what  U  true  of  the  collection  of  parallel  Bbres  which  we  call  the 
muscle  is  aW  true  of  each  fibre,  for  the  Bwelliug  at  any  part  of  the  muscle  a 
only  the  sum  of  the  swelling  of  the  individual  fibres;  and  if  we  were  able  to 
take  n  single  long  fibre  and  stimulate  it  at  one  end,  we  should  be  able, 
under  the  microscope,  to  see  u  swelling  or  bulging  accompanied  by  a  corre- 
sponding shortening,  i'.  e.,  to  see  a  contraction,  sweep  along  the  fibre  from  end 
to  end. 

If,  in  the  graphic  record  of  the  two  levers  just  mentioned,  we  count  the 
number  of  vibnilions  of  the  tuning-fork  which  intervene  between  the  mark 
on  the  record  which  indicates  the  l>eginnin^  of  the  rise  of  the  near  lever 
(that  is,  the  arrival  of  the  contraction  waveat  tbU  lever)  and  the  mark  which 
indicates  the  liej^inning  of  the  rise  of  the  far  lever,  this  will  give  us  the  time 
which  it  has  taken  (he  eontniclion  wave  to  travel  from  the  near  to  the  Air 
lever.  Let  us  sup|>0Ke  this  to  l)e  0.1)05  second.  Let  us  suppose  the  distance 
between  the  two  levers  to  be  lo  nmi.  The  contraction  wave,  then,  has  taken 
0.005  second  to  travel  15  mm.,  that  is  to  iray  it  has  travelled  at  the  rate  of  3 
metres  per  second.  And  indeed  we  find  by  this,  or  by  other  methods,  that  in  the 
frog's  mnscles  the  contraction  wave  does  travel  at  a  rate  which  may  be  put 
down  as  front  3  to  4  metres  a  second,  though  it  varies  under  diflerent  condi- 
tions. In  the  warm-blooded  mammal  the  rate  is  somewhat  greater,  and  may 
probably  Ik  put  down  at  5  metres  u  second  in  the  excised  muscle, rieing  po«- 
eibly  to  10  metres  in  n  muscle  within  the  Jiving  body. 

If,  acain,  in  the  graphic  record  of  the  two  levers  we  count,  iu  the  case  of 
either  lever,  the  number  of  vibrations  of  the  tuning-fork  which  interrene 
between  the  murk  where  the  lever  itegiiis  to  ri:^  and  the  mark  where  it  has 
finisheil  its  fall  and  returned  to  the  Itase-line,  wc  can  measure  the  time  inter- 
vening between  the  contraction  wave  reaching  the  lever  and  leaving  the  lever 
on  its  way  onward,  that  is  to  say  wccan  meoiiure  thctime  which  it  has  taken 
the  contraction  wave  to  \ituv  over  the  part  of  the  muscle  on  which  the  lever 
is  resting.  Let  its  suppoi^e  this  time  to  be,  say,  <>.l  second.  But  a  wave  which 
is  travelling  at  the  rate  of  3  metres  n  second  and  takes  0.1  second  to  pass 
over  any  jmint  niui^t  be  300  mm.  long.  And,  indeed,  we  find  that  iu  the 
frog  the  length  id'  the  coutraction  wave  may  be  put  down  as  varj'ing  from 
200  to  AW  mm.,  and  in  the  miiminal  it  is  not  verv  different. 

Now,  as  we  have  sai(i,  the  very  longesl  muscular  fibre  is  stated  to  be  at 
moat  oidy  about  40  mm.  in  length ;  hence,  in  an  ordinary  contraction,  during 
the  greater  jiart  of  the  duration  of  the  contraction  the  whole  length  of  the 
fibre  will  be  occupied  by  the  contniction  wave.  Just  at  the  bwinmng  of  the 
contraction  there  will  be  a  time  when  tJic  front  of  the  contraction  wave  has 
reached  for  instance  only  half  way  down  the  fibre  (supposing  the  stimulus  to 
be  applied,  as  iu  the  case  we  hiive  been  discussing,  at  one  end  only),  and  just 
at  the  end  of  the  contraction  there  will  be  a  lime,  for  instance,  when  the  con- 
traction has  left  the  half  of  the  fil)re  next  to  the  stimulus,  but  has  not  yet 
cleared  away  from  the  other  half.  Hut  nearly  all  the  rest  of  the  time  every 
part  of  the  tibre  will  be  in  some  phniie  or  other  of  contraction,  though  the 

(larti^  nearer  the  slinmlus  will  be  in  more  ailvauced  ])bases  than  the  parts 
iirtbcr  from  the  stimulus. 

This  is  true  when  a  mu^le  of  parallel  fibres  is  stimulated  artificially  at 
one  end  of  the  muscles,  and  when,  tbei'efore.  each  fibre  is  stimulated  at  one 
end.  It  is,  of  course,  all  the  more  true  when  u  muscle  of  ordinary  con- 
struction is  stinuilated  by  means  of  its  nerve.  The  stimulus  of  the  nervous 
impulse  impinges,  iu  this  case,  on  the  muscle  fibre  at  the  end-plate  which,  as 
we  have  said,  is  placed  toward  ijie  middle  of  the  fibre,  and  the  contraction 
wave  travels  from  the  endplate  iu  <>p]i<>.-iite  directions  toward  each  end,  nod 
has  accordingly  only  about  half  the  length  of  ibe  fibre  to  run  in.     All  the 


CRA!?OBS   I^T    JL    MCSC1.E    DL'RIXO  CONTRACTION', 


99 


I 


tnuK.  liierefore,  must  the  wliole  fibre  b«  in  a  state  ot' ooutravlion  at  lh«  MUBi 
lini*. 

It  will  be  observed  (liat  in  wUat  has  ju«t  b««u  aaitl  i)i«  raairacti^ii  wave 
hiu  liOFn  takeu  to  include  not  uul^  ilu-  cmntriictuin  propvr.  ilia,'  thickening 
Mill  K boric niiifc,  but  aliMi  Ihe  lelBxiitiou  and  rvturn  (»  llii;  iiiiliinil  form  ;  ibi- 
lin>L  |Mrt  >•(  ihe  \iu\-t:  up  to  the  Kuminit  of  ibi-  crast  oorratpuids  to  tbe 
■tinrtcniii^  nml  thirk<'niiig,  ih*'  di-clinc!  from  the  «iimmit  onwara  crimepontb 
lu  tba  n-luxBiioti.  Biii  w«  Have  aln-wlv  iiuiiitcd  tliiii  tliv  relaxation  ig  ao 
tial  [wrt  ••('  ihr  whole  act!  imlMil,  tn  a  lortaiii  wriiM<,  n»  fwrntial  as  t\w 
iMi-iiini:  iiM'lt*. 
_  5  44,  Miii'itr  linteluri:'.  n)  miueulnr  fibn.  S«>  far  we  have  1»ecii  dcalin;; 
with  the  iniK'C'U'  a*  it  whole  and  m  obvcneil  with  the  oaked  eye,  though  ne 
have  iueidrjttally  s{ii>kvN  of  fibres.  We  havn  now,  ronliuing  tiur  atlcntion 
cxoliir^ively  to  skeletal  aiusctcs,  1o  ocwitider  what  iDicrwonpic  changes  take 
[ilatsr  durins  a  eontraction,  what  are  the  rehUioHs  of  the  hiatologiciU  feature) 
tif  (be  DtuBcle  fibre  to  tlie  act  of  coulraL'tiuii. 

The  luuK  cylindrical  abealh  ofuircoleuiiua  is  occupied  hy  muscle  subtitaooe. 
After  death  the  muscle  substance  may  separate  from  the  sarcoleinma,  leaving 
lh«  latter  ea  a  distinct  nheath,  but  durioK  life  the  muscle  siilwtanoe  is  adherent 
to  tlie  san-okniHia,  so  that  uo  Hoe  i>f  sejiaration  between  the  two  can  be 
maila  out ;  liie  inovementa  of  tlif  oue  follow  exaetly  all  the  laovenveuta  of  tbo 
oii»cr,  , 

SaUtend  in  the  mmcle  sulioiaiu'e,  but,  in  the  mammal,  lying  for  the  iikmI 
imK  oloao  under  tiw  rtmmleuiina.  are  a  uuiul>er  of  nuclei,  oval  in  «ha|w,  nilh 
their  long  axo*  paralh-l  to  tbu  K-iiiith  of  th<;  lihro.  Around  each  nucli?ti»  \* 
a  tliin  layi'r  of  grauular-lookitig  nubolanci'  very  Mniilnr  In  ap|>earancfi  to  that 
fonunc  the  body  of  ii  whitr  blood'C»r|HiMrb',  and  like  iJiiil  ol^en  njiokon  of 
as  aaduTerantiatiid  pr»topliu>m.  A  small  •juniility  of  (ho  Mtnv  granular  itub- 
BtatMv  is  |in>lo»gi>il  (or  i«>me  dinlanoc,  iik  a  narrow  conical  streitk  from  uach 
end  of  thu  nucliip^  along  tbo  k-iigtli  of  the  fibrv. 

With  tha  exir|iU<M)  of  cboM  nuclei  with  their  granular  looking  bed  and 
thi?  end -plate  «r  eiid-|ilal<?s,  tolie  pmentlv  dtecribM,  all  lite  xtM  of  tliv  s(Hi«e 
eni'loaod  liy  the  surcolomma  from  one  eoti  of  tbo  Bbri'  to  the  other  apjwara  to 
tie  ouuupit^l  by  a  peculiar  material,  'Irintfl  niiur/i'  riiittiuire. 

It  i»  ittlli'd  rtrialed  boauM  it  is  marke<louI.  and  that  along  the  whole 
IsAgUi  uf  iti«  (ihrv.  br  tniiuveree  bandft  [Fig.  'i'i].  stretching  right  acrwe  the 

ir»a  K. 


s 


14 

l>i*>ia«NH«nc  tanwaanxivm  or  i  llunaoia. 
iw,  iwew-MWM.  wa<*U^of «  bUBdloctfiuu«cle-(«dsi  ft,  iWd  «utala»M.| 

lihrt.  of  »ulKlaiicei  which  is  very  iruiLipnrent,  bri-jhl  mAttntiCf,  alternating 
with  tiniilar  Imitds  of  >til>staii<«  which  has  a  dim  cloudy  appearance,  -iim 
mbMunfr ;  that  ia  ta  uy  the  tihrt!  is  marked  out  along  it^  whole  leugtli  by 
allamato  bright  band*  aud  ''na  IxihiU.  The  bright  bands  are  on  an  average 
about  1  ^  or  U>  n  aod  the  dim  baniU  about  2.5 /<  or  3  ^  ibick.  Bv  care- 
ful focuasing,  both  brigtit  hand*  aixl  dim  tMUfJs  may  be  traced  tlirough 
t}i«  whole  tcickiMMt  of  the  fibre,  w  that  the  whole  fibre  ap])ean  to  be  com- 
piaod  uf  bright  disca  lutd  dim  diacs  j>lnocd  alleni«t«ly  one  u|>ou  the  other 
ili>ng  tin*  nholc  length  of  tXw  f)l>re.  th<'  arrmngeBMDt  being  broken  hy  the 
cnd-jilBM  awl  here  aw)  there  by  the  uueWL 


TUB   COSTBACTltE  TlgSVSS. 

Whcii  n  mtifctilnr  fil>r«  is  tmi(vd  with  dilute  mioeral  itcids  it  »  vtrr  ipt 
to  hrvnk  up  tmiisvftrwly  iiito  diwe  [Fi^.  S'i],  ihr  mrcolemmii  beio);  dinolred, 
or  ao  nltvnil  lut  ciuily  to  dindo  into  fragmrnta  oormpoDding  to  the  diMs; 
•imI  ft  disc  ttMy  thus  be  obuincd  so  ihiD  as  to  comprise  only  a  Bingle  dim  or 
bright  band,  or  a  dim  baod  iritfa  a  thin  lnyvr  of  bright  subsiaDce  above  and 
bolow  it,  the  clearnce  having  taken  place  alon^  the  middle  of  the  bright 
bands. 

Wbei)  Imted  wicii  oertain  reagents,  alcohol,  chromic  acid,  elo.,  the  fihre 
is  rerv  apt  to  aplii  up  (and  the  splitting  up  may  be  aasisted  by  "  teiialiic") 
loiigitudiiially  into  ouIucuqs  of  variable  thickneas,  some  of  which  iioivcver 
may  be  escee<liii^Iy  thin,  and  are  then  sumetitnea  spoken  of  m  "  tibrillir." 
Uolh  ihe«i.'  di.-H-s  luid  fitiriltiu  arc  artilicia)  prrtducts,  the  resultn  of  a  trntiit- 
verse  w  luDj^'itiidinBl  ck-ava^  of  the  dead,  hanlcnr*!.  or  olhenriiie  pn'mr^l 
Uiirt'lir  :-ut»lunc<'.     Tli<-t  may  Ri<irv<)V«r  W  obtained  in  nlmuU  any  ihit'KnciM 

thinnciM,  and  thivt'  ai*>»  and  tibrillie  do  not  by  lhriniwlv««  provi'  iiiacb 
l>eyond  th«  fact  that  the  fibre  tendit  to  cleave  in  tbi-  two  directJoDS. 

The  living  fibre  himcvcr,  Uioiigfa  at  limei  i)uilc  glantr  looking,  thv  bright 
bands  appearing  like  transparent  giais  and  iIh;  dim  band*  tikr  gnxtnd  gtaw. 
!•  at  other  titne»  marked  with  loiigititdina!  Iin«s  giving  rise  to  a  longitudinal 
siriation,  sometimes  conspicuous  and  oc<-asioRftlIy  obscuring  the  lmn*v«rai 
StriatioD.  In  the  musclm  of  some  insects  each  dim  band  hns  a  dislinc-l  |»li* 
siulc  appearance  as  if  made  up  of  a  number  uf  "tibrillie"  or"  rods"  plaoed 
side  bv  side  and  imbedded  in  some  material  of  a  diflerenl  nature ;  moreover 
tbeMubrilln  or  roda  may,  with  greater  dilhculty.  W  iraoed  tbrongh  the 
britcht  bands,  and  tJiat  at  tiroee  luoug  the  whole  length  of  the  tihre.  And 
there  ia  a  great  ileal  of  evidence,  into  which  we  cannot  enter  here,  which 
goes  to  prove  that  ill  all  striated  muscle,  mammalian  muscle  incttidird,  ilie 
muscli'  nuliMtancc  is  rally  eomnoaed  of  longitudinally  tilaoed  natural  ^'^riVte 
of  a  c«innin  nature,  inifieddi-d  in  nn  iitlerfil/riKtir  suMiance  of  a  ditTereat 
nature.  In  maiuiualmn  muHcb-  and  verU'bnile  uiusi:le  generally  theao  Bbrillm 
are  exceedingly  thin  and  in  most  case*  are  not  sliarply  deBi'ted  by  nptical 
cbaraclera  from  their  intcrfihritlar  bed;  in  insect  muKlm  and  aoiiie  nibfr 
musclm  they  arc  reliitiwiy  large,  well  ilefined.  and  coiw])ieiiiiu*.  The  arlirt- 
oial  librilla)  obtjiincd  by  tciu^ing  may  [icrhaiM  in  some  canv*  when^  thi.^'  an 
exoredingly  thin  correspond  to  tbcso  natural  fibrillie,  but  in  llw  roiyontr  uT 
cwM  they  certainly  do  not. 

In  ceiiain  insect  muscles  each  bright  band  has  in  it  two  (onoioetimes 
more)  dark  lines  which  are  granular  in  appearance  and  may  Iw  motrcd  by 
iu)e<|uale  inxguifying  power  into  rows  of  ffranuln.  8iuoe  Ihev  may  hv  focus- 
sing be  traced  throusb  the  whole  thickness  of  the  Hbro  tde  lines  arc  the 
expression  of  discs.  Freijuently  the  lines  iu  the  bright  bande  are  so  ooiisuio- 
uous  as  li>  contribute  a  greater  share  to  the  iranerene  strialion  of  the  libre 
than  do  thtt  dim  bands.  Similar  gniniilnr  lines  (rows  or  rather  disosof 
granules  <  mar  also  be  seen,  though  less  distinctly,  in  vertebrate,  including 
mammalian,  muscle. 

Besides  Ihcac  granular  lines  whose  position  in  ibe  bri^dit  Ivand  is  nt-ar  to 
tlic  dim  bands,  ollcn  aiipenrin^  to  form,  es  it  were,  the  upper  ed^re  of  tbt-  dim 
hand  Mavi  and  the  lowir  eiigi'  ••>'  the  dim  band  aliovi-,  then-  mav  if  al»» 
sometimes  traced  nmilhiT  iraii>ivtir«i^  tbin  lin«  in  tbt?  very  middle  iif  lli<'  bright 
Iwnd,  This  liiiv.  like  the  ulhtir  lines  /or  luuidii),  is  the  expn-iuion  of  ii  ilint* 
and  has  hvea  bclil  by  Mwne  obsvrvcm  tii  rcj>rei*nt  a  meiuhrane  stn-lflied 
arroas  the  whole  thickiieM  of  the  Kbrc  and  a<lhcrent  at  the  cin'timftu'viice 
with  the  snrcolemran  :  in  this  sente  it  [»  spoken  of  n«  Kt'ixuui*  Hinnbroiif. 
The  reasons  for  believing  that  the  lino  milly  re|»re«ents  a  <lelin{te  mcmbnim* 


» 


I 


ntit  liov«v«r  appear  lo  h*!  Mk-quaW.  Il  may  Ik  >poke»  of  as  tliv  "  inUr- 
Bi«diat«  Vhk" 

Wlicii  a  thin  traiwveno  *cctii>n  of  froEcii  niu»clu  w  I'xnniineil  quiu-  fradi 
nnilrf  a  U'tgh  |H>wcr,  the  niii»cli!  KiiWtunott  within  tboMroolcmnin  Im  M-L*n  Co 
lie  iiiiirkrtl  out  intii  n  niimbiT  ot'«nuil]  more  or  lem  poljgODal  an--iM,  nod  n 
flioiilnr  nrrniii^cnK'nt  into  antiu  RtHy  also  be  seen  in  transverae  »vctii>n*  of 
prr]>art.><l  niu«cle.  though  lh«  foutiim  of  the  arvw  are  somcnhat  <liK'erenl 
from  thiMe  Men  in  t\w  fresh  living  tibre.  Tbeec  areas  are  tjiDken  of  lu 
"  Gnhaheim'e  areas  ;"  thciy  are  very  much  larger  than  the  dinmcti;r  of  a 
tihrilla  as  iuilicateil  hv  the  lon^'ituilinal  rtrialioo,  and  iuile«(i  corresuuiK)  to 
■  ii'htile  bumlle  of  sucn  tihrilln^.  TiK-ir  existence  seeius  to  indicate  itiBt  llie 
tilirilhu  are  nrranKed  in  hmKitiidinal  prisms  sep«raled  from  each  otlier  by  a 
lander  nmouoi  »f  inleTtlbrillar  fmbdtauce  tiiaii  thai  uuttiajf  to|{ether  the  iudi- 
vtdual  Hbrillie  furmiu^ea<th  prism. 

I.ji»i)y  il  may  bi-  meiitiouni  thai  not  nnl^  are  the  various  k'^i'iIa'  liaet 
M  tiiii<>«  VMibto  with  ditRculty  or  quite  invistlile,  but  that  eveu  tlie  di«tii)c- 
Uou  t>et«i4^i  dim  and  brij^lit  bands  is  M-caiiioiially  very  faint  i>r  obscure,  tlie 
wIkiIi'  niuwOr  stihstaDi*.  ajxtrt  from  the  nuclei,  a)i[M-arin^  almnnt  homogen<Niiis, 

Wiiboot  iitutiiiniiiiif  to  disciHN  the  manvand  varimi*  iuterpnetations  of  the 
al>ov«  niul  other  it<-liiiu  concerning  the  minute  structure  iif  stHat«d  muMular 
fibre,  «(«  may  ht're  oHiti-nt  nunxdvtii  with  the  fDltowing  j^ueral  coiicluaioDs: 

(1;  That  thi:  miwle  ftiilwtaiici:  is  iiun|>o«H>d  of  bngituiliiially  i)itipos«d 
JihrHlr   iprifliahly  rylli>.|ricHl  in  ptncml  form    and    iiM)liably  arranged  in 

aeiliidimil   pri>uiii  im)ic^dcd   in  an  iitirrfiiiriUny  fiiMannt,  which  appears 

^M  Ian  dintrMitialol  tlmn  the  fihrillig  thaiast^vfa  and  which  is  jirobnMy 
'  loous  with  the  unditfcreiitiatci  protopleaia  round  Ihv  nuclei.  The 
ilertilirillar  sub*tnnce  stains  more  readily  with  gold  chloride  than  il<>  the 
fibrillK,  and  hence  in  gold  chloride  tpcdmcua  appear  as  ii  sort  of  Ricshwork, 
vilb  InnKittidinal  epace^i  corresponding  to  the  fibrillin. 

<'i)  That  the  iniertibrillar  subsianoe  is,  relaliTely  to  the  6brill»,  more 
abuiMJant  in  the  muj<il«E  of  some  animab  than  in  those  of  others,  being  tur 
instance  very  conspicuous  in  the  muscles  of  iiuects,  in  which  animaU  we 
shiiulil  iiniurally  expect  the  less  dillerentiated  material  to  be  more  plentiful 
tlian  in  the  muwlesof  the  more  hixhly  developed  mammal. 

(.1;  That  Ihe  fibrillH.-  and  iuterAbrillar  subsiance  having  Oift^rent  refrac- 
the  fxivrrre.  some  of  the  oiitical  featura  of  niunclc  muy  he  due,  on  (he  one 
hand  t'l  thv  relative  pr«>)nrtion  of  fibriltw  lo  iiiierrilirilliir  Mibslance,  and  on 
th<-  uthiT  haiiil  li>  thtt  fibrillin  not  \ieinic  cylindricitl  tliroiighout  the  length 
tlip  iibri-  but  cuualrictvl  at  intervals,  uiiil  thus  becoming  lieaded  or 
lilif'irm  ;  fur  liMiUice  ihfi  TDwa  of  granulni  npoki^u  of  abitve  arc  by  somv 

_  inliil  lui  comspondine  to  a^rtgations  of  inlnrtilirilUr  matiirial  Htlitig 
ip  ihi-  *|inrre  where  the  6l>rilU'  arc  moat  coiMtrictnd.     But  it  dow  not  seem 
imsiblf  Hi  ihf)  prciteRt  time  to  make  any  «iatcnK-Qt  which  will  salisJaclorily 
•Xplaiii  all  the  various  appciamiior;'  mot  wich- 

t  fiS.  Wa  mar  now  r^'turn  to  the  ijuotion.  What  hapjwns  when  a  contrac- 
tlno  wave  "wi-cps  over  ihe  fibre? 

MiiwTular  fibres  may  he  examined  eT«n  under  high  powers  of  th«  micro- 
Kope  while  they  arc  yet  living  and  contractile :  the  contraction  ilself  may 
l<e  *vrt>,  hut  lh«  rate  at  which  the  wave  travels  is  too  rapid  to  permit  satis- 
bctory  observations  beiii^  made  as  to  the  minute  changm  which  accompany 
crintrDdion.  It  freipienlly  happens  however  that  when  living  muscle 
Itenn  trealMl  with  t?erlain  reagents,  as  for  instance  with  osmic  acid  vanor, 
*ub*«^iKtitty  prtpiired  for  examiiuUion,  fibres  are  found  in  which  a 
tog,  a  thickening:  and  sbortening,  over  a  greeter  or  leas  part  of  the  length 


THE  eOXTRACTlLB   TtSSCES, 

of  tho  librc.  hns  )>c«n  lixcd  by  the  o«niu<  ncjil  or  other  ri;agent.  Such  a 
bul|,nDc  obviously  i)itl«re  f^om  n  normal  contraclion  in  beiof;  coofitie^l  to  a 
part  of  the  l«apth  of  the  tibiv,  whercne,  at  we  have  eaid.  a  Doroial  wave  of 
contraction,  bein^  very  much  longer  than  any  fibre,  occupi«  llie  whole 
leofflii  of  the  fibre  at  onoe.  We  may  however  repird  this  bul^ns  bs  b  rery 
■hon.  a  ven'  abbreviate<t  wave  of  contraction,  and  aaaume  tlial  the  dion^ 
rUible  in  micb  a  ithort  bulging  also  take  place  in  a  nnrmal  oontraclitX). 

Admitting  thin  ostium ptii^n,  we  learn  fVom  such  preimnitions  Umt  in  the 
ooDtraeting  region  of  the  fibre,  while  Iioili  dim  and  oright  bamU  Wome 
brooder  acroM  the  fibre,  and  corrcNimndingly  thiuncr  oloiig  (Itc  l^n^th  of  (he 
fibre,  n  remarkable  change  lakce  pinou  between  thr  diiii  buiuls,  brigln  bnnd«, 
and  granular  Ithi'H.  We  have  wen  that  in  (hf;  fibre  at  rest  Ihe  intiTinciiiatc 
line  in  the  briglil  band  is  in  moat  caM«  iiiconiipiciioii* ;  in  the  ■■i>n[racling 
fibre,  on  the  contrnry,  a  dark  lino  in  the  middle  of  thr  bright  band  in  the 
porition  of  the  intermediate  lino  becomes  very  distinct.  \t  m  pass  along 
the  fibre  from  the  beginning  of  the  cmilniction  nave  to  the  summit  of  the 
nave,  where  the  thickening  ie  grcuto^t,  this  line  becomes  more  and  ntore 
tiriking,  until  at  the  lieignt  of  the  conlraction  it  becomes  a  very  marked 
dark  Ime  or  thin  dark  band,  ftiri  f/'ittii  with  this  change,  the  distiuctinn 
between  the  dim  and  brijfhl  bauds  become  leaa  and  leasjnarked;  these 
appear  to  become  confused  together,  until  at  the  height  of  the  contradkni, 
the  whole  apace  between  eacli  tn'o  now  conspicuuiiA  dark  line)  is  occupied  by 
a  subiCance  which  can  be  called  neither  dim  nor  briglil,  but  which  in  oon- 
trnsl  to  the  dark  line  apiMwr^  more  or  leM  bright  luid  irausparcnt,  So  that 
in  the  contracting  jutrt  there  in.  ut  the  heighl  of  the  contraction,  a  rorereal 
of  the  atate  of  thing*  proper  to  the  pari  at  re«t.  The  place  occupied  by  the 
bright  band,  in  the  state  "f  rwt.  im  now  largely  filled  by  a  roiigpicuoua  dark 
line  which  previously  was  represented  by  the  inconspicuous  intermediate 
line,  and  the  place  occupied  by  the  conspicuous  dim  band  of  the  fibre  at  leat 
DOW  sectnB  by  oompariaon  with  the  dark  line  the  brighter  part  of  the  fibre. 
The  contracting  fibre  is,  like  the  fiiire  at  rest,  striated,  but  iia  striatitin  i>  dif- 
ferent in  its  nature  fmrn  the  niilunil  ^trialion  of  the  resting  fibr«;  and  tl  la 
bdd  by  sofoe  that  in  the  earlier  phiues  of  the  coutraction,  while  the  old  uiilu- 
ral  utriatiea  is  liciiig  replaced  by  ibe  new  slriatiun,  there  U  a  Mage  in  which 
all  Ml  rial  ion  Is  lost. 

We  may  add  thnl  the  outline  of  the  sarcolemma,  which  in  the  fibre  at  rest 
is  (piitc  even,  bcconicj'  during  the  contraction  indented  oppocito  the  inlerme- 
diate  line,  and  bulges  out  in  the  interval  hctweon  each  two  iDtcrme«Iiail« 
linca,  Iho  bulging  and  indentation  becoming  mora  marked  the  greater  the 
con  traction, 

588.  We  can  learn  something  further  about  this  remarkable  change  by 
examining  the  fibre  under  polarized  light, 

When  ordinary  light  la  sent  through  a  Nicol  prism  (nbieh  Is  a  rhomb  of  toe- 
land  spardiviiied  into  two  in  a  cortam  dircciinii.  the  halve*  being  Mbsequetilly 
cemcntrd  tngctbrr  in  a  special  wav)  it  uiirl<incucH  a  change  in  juMJiig  through  the 
prism  and  is  mid  to  be  polarited.  One  rflecl  of  this  iiolarimtiea  ia  that  a  ray 
of  liglii  whii-li  lias  piMcd  through  one  Xii-ul  prism  will  or  will  nut  pass  lhrotu[h  a 
•econd  Nicol  according  to  the  relHtive  positcui  of  tlie  two  prisms.  Thus,  If  the 
second  Nicnl  be  so  plntrd  thnt  whnl  is  cnllcrl  it*  ''  nptlc  axis  be  in  a  line  wllh  or 
(Mirallcl  to  the  optir  axis  of  the  lir«t  Nicol  the  lixlit  pns*ing  through  the  first  Nicol 
aill  also  poM  through  the  necoiid.  But  if  the  second  Nicol  be  rotntod  until  its 
optic  axis  iaat  right  aagtes  with  the  optic  axis  of  the  Anit  Nicol  uoueuf  the  lioht 
passing  through  the  former  will  poM  through  the  latter ;  the  prisms  lu  this  position 
are  said  In  be '' crossed.''  In  iiilermeHiaie  positions  more  or  lest  light  passes 
tlir»u)[h  the  M-cond  Nicol  according  ti  the  nngli;  betn-ccn  the  two  optic  axiv. 

Hence  when  one  Nicol  is  placed  beneath  the  stage  of  a  mtcnMcope  so  thai  the 


CIIANOES  IN    A    HVSCtE   DCRiyo   COKTRACTION. 


r 

■  Ucbt  tan  ika  mirrvr  i*  wat  Uirough  it.  anil  anoilier  NIro)  it  placed  in  llie  ne- 
'  ptfc*.  lb*  fifid  nf  rtio  aiictoMopc  will  appear  ilHtk  •rhrn  ibo  cyo-ptccr  Ntcol  b 

n>tAi«d  an  that  luoplir  axii  in  al  right  aiifira  to  ihi-  ofilic  axborUic  lower  Ninil. 

awl  totMMUMiilr  ibc  light  pmmiag  ihrouih  ih«  tower  Niool  ia  aupped  br  it.     If, 

bfvrrrr.  l&c  optii-  nxU  of  ibe  eye- picc« Niool  i*]>aralld  loiliatuf  tlielowt-r  NIcol, 

ihr  tiybl  from  the  latlrr  will  pMa  ibroneh  lb«  former  aixl  the  Mt\  will  lie  bright; 

iMi  aa  Uw  pr«-t>icc«  i«  emduall^  roiaieif  from  on*  pMilion  tn  tbe  other  ibe  brinkt- 

nmm  of  lb*  MM  will  dlminidi  «r  iiit'r«M4>. 

Baib  tbi  Nicola  are  ci>iu|mm*()  of  doubljr  refractive  oiaiciial.     If  now  n  third 

dacblj  r*tr»etiv*  mnl«rlnl  ba  |>laced  on  the  au^,  and  tlierefurv  betwocn  iho  twn 

INkak.  I'  |-a«un|c  thrrxigh  lb«lower  Nicol  will  (inactftain  piwilioti  of  lh« 

dotibh  -  tuatcrial  on  the  stave,  tbat  i*  to  aay.  when  iu  optic  dim  bare  a 

f^ftaJn  ^--.I'fn  I  I'aax  thr<>ii|;h  il,  and  alao  throogb  the  trot*td  Nicol  in  tb«  eye- 
fiwnt.  llrnirt  ilii-  d'Mildy  refractive  material  on  the  alage  (or  nucb  paria  of  1(  aa 
»n  Id  tbp  proprr  poaition  In  rtapeci  to  their  optic  aita)  will,  when  the  efe-iriae« 
yteal  U  riMMd,  Bp|war  illuminated  and  bright  on  a  dark  Sc\<l.  In  thin  way  the 
Rafa(as<«  of  donblj  rtfraciiva  niatarial  Ui  n  preparation  may  be  ili-tect«d. 
Wbra  tDuacle  prvpurod  «ihI  nouottd  in  OiiiwIk  balsam  b  examined  iii 
tb«  micnwcope  bM«eeo  Nicnl  prism*,  on«  ou  the  tufe  b«loM'  tb«  ohjw!!,  Aud 
Ibr  iTtbvr  In  tbo  «y«-pJKW,  the  &bm  atand  out  na  bright  ohJeciA  on  the  tliu-lc 
(rauntl  of  thr  ti«M  wh«D  ibe  *xe»  of  ihv  jinmiM  are  crwaed.  Ou  cl»er 
■tion  il  ia  Mm  that  iIk-  |iAria  which  iirc  britcht  nr«  chJi-fly  th«  dim 
Tbia  indieaiM  Uint  il  is  tW  dim  bnii<)«  which  iir«-  doiibty  rrrrnctivc, 
vtuptnpif,  or  an  cbjcfly  tn&de  up  of  itniMHrvpic  subaUuKC;  thore  sceuw, 
•r,  to  be  toam  alight  nniouni  of  aniaotropic  mibtlsnn  In  the  bt^ht 
.  tbnuffh  these  aa  ■  wltole  n{>|)«ar  fingk  refmclive  or  itotropU.  Th* 
Sbn  tcnritoglr  appcan  banded  or  <tnatc<l  with  allrmale  bunds  of  anno- 
Iropi^  aod  woiropir  mnteriiil.  Aoconliog  to  tnoat  aulhorB  auch  an  altcma- 
in  uf  aniaoirMpic  lutd  ^chi^tlv)  i^utnijiic  banda  which  ia  obrioua  in  a  dead 
nd  pfvnrcd  fibre  exitta  bIh)  ia  tba  living  fibre ;  but  aotue  mikinUia  thai  tlie 
MB|fllire  b  unifomilr  ani»i>tra|>ic. 

SM,  when  n  fibrv  iiintracto.  la  «[Mle  of  the  coiifliAioti  previouulT  mentioned 
bllMHldun  and  briicht  WniU,  ihrrv  ia  no  cunfuniuti  bclnceii  tin;  auiai>tropic 
«d  iaotlBpio  maMnal.  The  aniaotnipic,  doubly  refrnctive  baud*,  bright 
wiar  cnwed  Nicola,  oocupring  tb<'  poailion  of  the  dim  band*  in  Ibe  reatiog 
Sbf«.  rendo  doubly  refractrvc.  bright  under  enixard  NI«olB,eTen  at  the  verjr 
Uflil  at  Uw  coDtraitino.  The  iiwtm|HC,  einely  refradirc  bnnd.->.  dark  under 
iMMDd  NicfiKoccdpytn);  the  poeitii>&  of  the  bright  liiiml>t  in  the  fibre  iit  r«M, 
IIMUO  Hiiiruiiic  and  dark  uiidcr  croeacd  Nicoh>  nl  the  vrr}'  height  uf  the 
flsUvctioD.  All  Uiat  can  becMO  ia  that  iherRinglTrPl'mcltveiMtrujiic  tMuida 
t«naw  very  thin  indeed  during  the  cnnimctiou,  while  the  nnivitnipic  ImuiJn, 
rtmigli  of  courw  becomioK  thinner  and  broader  ia  the  contriittion.  dn  not 
io  tbiu  M  do  the  iiotropiir  band*;  in  other  word^.  while  both  biitidn 
thinner  aud  bruader.  ine  doubly  refntctive  ani!>»trqpic  bimd  mviii* 


MiaenMe  at  ibe  expense  of  tito  »in(;ly  re&activc  iiiolnjriic  Imnd. 

{ff.  We  call  altrniion  (u  these  Mcta  because  they  "now  how  complex  la 
fe  hC  "f  f-iinimctiDn.  The  mer<'  broadeuinx  and  «hortt'iiinK  of  each  MClion 
If  tba  0bn?  i*  at  ItoUom,  a  L ran* I- •en (ion  of  llie  ntolecules  of  tli«  iiiusi'lo  hiIk 
Canoa.  If  we  imagiin'  n  cjiniMny  of  100  »oldier«  ten  ranks  deep,  with  l«n 
aM«  in  rach  rank,  mpidly,  but  by  u  Mriea  of  );ntdiiiians.  to  extend  out  into 
a  doable  line  with  'lO  ura  in  cnc^  line,  wc  ihall  have  a  roii;;b  image  of  the 
■MVtfmcnt  of  the  molevnlta  during  a  muKCiilar  cmtraclion.  But,  from  what 
Ua  b«an  mM.  it  ia  obvious  that  tlio  moveiiii-nl,  in  Ktriatei)  muwle  at  l«aM,  is 
a  Twry  eomplicate'l  otie ;  in  other  forms  of  cuntmctile  tiwiie  it  uuiv  be,  as  we 
«kUI  aot.  more  simple.  Why  the  muvr-mcul  Is  so  complicatml  in  strialeil 
mud*,  what  purpuaes  it  serves,  why  ibu  skelcMl  intisclcs  an;  (triat«d,  we  do 


104 


Tni    COXTRACTir.K    TlSSfEB. 


ii'>(  ai  i>r»eiit  kiuivt.  Afitiareutlj'  where  xtvlfl  nod  ntjud  contraction  h 
roguirLHl  llit- coiitraclik- t'lMtie  iti.ilriauil  iiiunck':  but  how  the  ttrUtioti  Mft, 
an  Ui  upeak,  tli«  cuntrii<;ti»ii  wo  ilo  ti»(  kimw.  Wu  latirn't  !i»y  wlint  fbnrc  in 
thr  net  of  coDtrnctioii  U  to  be  alli)iu.-ij  tn  iIr*  avvfi-ii]  jiaiia.  Sinci*,  durine 
a  conlntctioii,  the  fibrv  biilgi-n  out  more  <i])ji'»iti.-  In  mcli  dim  dM',  nnil 
IN  in(Iir:itri)  itppotiiu-  Id  witli  brljihl  disc,  since  tliL*  •liin  ili>c  i>  luorr  largely 
('(irii|)D«cd  i>f  HMiKolriijiIc  iiint<-riitl  lliiiu  l.hc  Jval  ul'  thr  fil>n-,  nnd  »iticc  the 
aiiiHDtropic  nintcrhil  in  ihi!  |»<H>itI'>ii  of  llie  dim  disc  incrvtiMv  ilnring  a  con- 
l  nidi  on.  we  might  iwrlmjw  iiifvr  ihiil  thr  dim  diec  nilht'r  ihnii  the  brizhl 
diai:  It  tho  csk'iitially  active  niirt.  Ae^iiniiiij^  that  itic  Dhrillar  Euhstance  is 
more  ahundaiit  in  the  dim  discn,  while  rliu  interlibrillnr  substance  U  more 
abutidajil  in  the  bright  disc*,  and  ihiit  the  fibrillar  subUaoce  is  anisotropic 
(and  hence  the  dim  discs  largely  an  is  n  tropic),  while  the  intviKbrillar  sub- 
stance is  ieotropic,  we  niigbl  also  be  inclinet]  to  infer  it  is  the  fibrillar  and 
not  the  intertibrillar  substance  which  really  carries  out  the  contraction  ;  but 
even  this  much  is  not  yet  definitely  proved. 

One  lIiiD]{  must  be  remembered.  The  muscle  sulalance,  thouj;!)  it  po*- 
»et«cs  llie  ooniplioated  structure,  and  ^oes  tbiriugh  the  remarkable  chan|^ 
which  we  have  deacribed,  is  while  it  is  living  and  iuutct  iu  a  condition  whicli 
we  are  driven  to  »])Mik  of  ai  *cmi-IUiid.  The  whole  ut  ii  is  e^ttciiiinlly  nn/itile, 
Th«  very  act  ot'coiilrartioti  indeed  ahows  thk ;  btit  it  it>  uiohile  in  the  Mnse  that 
ii'i  part  uf  it,  vxivpl  of  <!ciui'<R  the  iiuciri  and  sarcnlemma,  nvither  dint  nor 
lirifcht  giulKtlnnct-',  iii-ilher  lihrJUar  nor  intvrfilirillar  aulMancc,  cnii  be  regarded 
an  a  hard  and  limt  structure.  A  minute  nematiiid  worm  hat  been  xeon  wan- 
dering in  the  midst  of  lliesulislnnce  uf  a  living  rnntritctilc  fibre  ;  as  it  moved 
nlonf:,  the.  muH-lcsnhstHnce  gave  way  In-fore  it,  nndclowd  up  again  behind  ii, 
dim  bandx  and  bright  bands  all  falling  back  into  their  proper  placo;.  We  may 
wippotv  that  in  this  case  the  worm  threaded  its  way  in  a  Huid  interfibrillar 
Buhslance  between  and  among  highly  extensible  and  elastic  tibrilltt'.  Bui 
even  on  such  a  view,  and  Mill  more  cm  the  view  that  the  fibrillar  sulmtuneu 
also  was  bruken  and  closed  up  again,  the  mainieuRnce  of  sucbdelinit*  bintct- 
loKical  features  as  tho«e  whidi  we  have  dwcribed  iu  material  so  mobile  can 
only  be  etfecied,  even  in  the  fibre  at  rexl.  at  mime  considerable  ox{i«uidituro 
ofeiii-rgy  :  which  energy  it  may  be  ex|)ecieil  haa  a  cJicniical  sourctv  During 
the  CuDtraction  then'  i.->  a  still  further  exjieudilure  of  energy,  some  of  which, 
■■  we  have  seen,  nmy  leave  the  muscle  u-i  "  work  dune;"  thi*  vaergy,  Uke- 
wiiH',  may  be  rxpccti-il  t<i  have  a  dicmical  source.  \Vc  miirt,  thfirelore.  now 
lura  Iu  the  chemistry  of  muscle. 

The  Cliemistiy  of  ^ftt»r!f. 

$58.  We  said  in  the  Introduction  that  it  was  difficult  to  make  out  with 
certainty  the  exact  chemical  dift'eremes  between  tlead  and  livios  «ui>- 
Mance.  Muscle,  however,  in  dyini^  uudergues  a  reuiarkalile  chemical  eliaug*, 
which  may  l>e  studied  with  comparative  ease.  We  have  already  said  that 
nil  nm.tcles,  within  a  certain  time  after  removal  from  the  biuly,  or,  if  still 
rcRuiiiiin)c  part  of  the  budy,  within  a  cerLaiu  time  atliM*  "  p;neral  "  death  of 
thv  body,  low  their  irritability,  luid  that  the  low  nf  irri lability,  which,  even 
when  rapid,  is  graduul,  is  unccwded  by  an  event  which  i*  somewhat  more 
sudden,  vit..  the  aiirmiicu  inio  the  condition  known  ns  ri</or  utorlit.  The 
occumonce  of  rigor  mortis,  or  cadaveric  rigidity,  ns  it  is  sometimes  called, 
which  may  be  considerwl  ns  the  token  uf  the  death  of  the  muscle,  is  marked 
by  the  following  features  :  The  living  muscle  poeseBKe  n  certain  tranj-lucencv, 
the  rigid  muscle  is  distinctly  more  opaijue.  The  living  muscle  is  very  exteu- 
»iii|«  and  elastic,  it  stretches  readily  ami  to  a  considerable  extent  whtin  a 


OIIANCIKS   IN    A    MI~Sl'I.£   DCRINU    COXTH ACTION.       105 


nvte^i  b  bUDi;  upon  it,  or  vlieu  uiy  truction  is  applied  Co  i(.  bui  a)ice>lily 
innd,  under  normal  circa nuuuwce.  c«iupl«telv  relurna  lo  iu  oriKiual  leiif|;tn 
twWn  tbe  w«i|;ht  or  moUan  is  mn->ved ;  as  w«  shall  see.  however,  the 
twpfdiir  and  cuiupleteuen  of  the  mtuni  dejie>iiU  on  tlie  c»udilioTi  oPthu 
nDKlr.  a  xell-auuriahed  activo  inuacle  n->:aiiiiiiK  il»  normal  lcu;,'Lh  much 
Mnr*  mpdiy  and  cuoiplelcly  thnu  n  timl  uiid  cxhausiud  muacle.  A  diwii 
ri^d  MiMaJe  ia  muelt  l«a»  #x[iiisil>li>,  and  nt  ihv  Mimv  lime  miidi  lean  dantic : 
lh»  MHela  DOW  nquina  oonri<Uniblv  I'on-v  to  xiretcli  it.  niid  vrhi>n  the  forci' 
h  iVMand,  Aot»  not.  aa  before,  ruturn  to  it*  fomivt  loiijclh.  To  the  Imtch 
tbt  nglMl  maicle  hiw  loK  miirli  <>(  il*  formtr  sofliwff.  and  bun  become  lirmvr 
■ad  Bar»  raaiitaot.  Tbe  cntmnoc  iiilo  rigur  morti*  u,  moreover,  itccurapn- 
itini  bf  s  ilioneniiig  or  contraclion,  irhich  may,  under  nrtain  circunMaiict*. 
W  (■■Mdrnhle.  The  energy  of  thi«  coiitnietioo  is  not  great,  ao  iliat  any 
MUial  •borteningMenailr  [irevcttted  by  the  prcscnceofeveu  a  Blight  oppoaing 

Now  tbe  cbenii<^l  features  of  the  dead  rigid  mu»cle  are  also  6trikiu|;ly  dif- 
I  trrtnl  Tnttn  those  of  ibe  living  muscle. 

t  W.  If  a  (if-iJ  tntiM/e,  from  which  all  bl,  teiidon,  fascia,  and  connective 
bate  Ijeaiaa  much  a*  puaaible  mmoTcd,  andHbicb  baa  been  &eed  from 
,„.  _  !>r  the  injection  of  "  nonunl"  ulineaolution,  be  minced  and  re|Matedlr 
•■•bed  with  water,  the  wii!ibiii>;ii  will  <-<>maiii  ciTlitlu  f  irma  of  albumin  nnil 
•vitain  eitntcUve  iKxtiex,  of  »)iich  we  •hull  ^\K-ii\t  iliroi-lly.  Wbt^ii  tbe  nii^h- 
ir^  bia  bevB  oontinuud  until  ihr  Kii.->h'W'iiti.'r  give*  no  proteid  rmetioii.  a 
hm  portion  of  tnuKb'  will  iilill  ri'muiii  iitnliiwilvvi).    If  lhi«  l>c  treated  with 

■  tOpiraetlt.  aolutinn  of  n  iiuutnil  itnit,  ummmiinm  chloride  Iwin^  (be  be«t, 

■  luM  portion  of  it  will  Uvmu-  dlwilvcd  ;  the  Foliitioii,  htiut'vcr,  w  more  or 
!(■  UBparfiKt  and  Hlten  vith  didicully.  If  tbe  filtrate  be  atloncd  to  full 
it9p  vf  drop  into  a  large  i^uantiiy  of  distilled  water,  a  while  Hocculent 
MU«r  will  M  j)reeipitat«d.  Tliis  tlocculeut  pret^ipitale  ia  iiiytMin.  Myosin 
»t(ir»ieH.  ifiviniE  ibe  ordinary  pmteid  reaction*,  and  having  the  tame  geu- 
titi  rlvnieoiary  eom|N3ailiu«  a*  other  pr»teiilit.  It  is  soluble  iu  dilute  sidiue 
Mhliuiw,  rejieciallr  tboae  of  ammonium  chloride,  and  may  be  classed  in  the 
^oknlia  family,  t]»ough  it  it  not  xo  eolubh'  an  pa  rag  In  but  in,  requiring  a 
Nrafn-aolnUan  of  a  neutral  mlt  t<t  dinolve  it;  thim,  while  soluble  i»a5 
•rlOptr  cMt.  solution  nf  giich  a  #nlt.  it  w  far  len  ihiIuIiIc  in  a  1  per  cent, 
•cimfaa.  wtiieb,  B«  nr  have  SM11.  rvudilv  diiwilvt^  piimglnbulin.  Fnim  ila 
•(■ina  la  iMulral  saline  Mlutioii  it  i*  prccipilntol  by  Mturntion  with  n 
■Mtal  alt,  preferably  sixliuin  ehloride.  and  may  be  piirilieil  by  Iwing 
•kM  with  a  Mturale<i  »>luiio(i,  diaaolved  sgnin  in  a  weaker  solution,  and 
rr  I  by  Mliiraiioo.  Diavilved  in  saline  solutions  it  readily  conx- 
HI'  I  healed — i. «..  ia  conveHed  into  coagulated  proleid — and  il  in 
•wiliy  nf  notice  thai  it  congululcd  at  a  coinpttratively  low  toinpernlure,  viz., 
*b«l  08'  C  ;  this  il  will  be  remeiulvered  lb  the  temperature  al  which  tibriii- 
in  It  oiagulated,  whereas  paragloliuliu.  scnim-alliumiu,  and  many  other 
pteifis  do  wA  coagulate  until  a  hichiT  lem|ienilure,  75°  C,  is  rea^'hed. 
Skttirf)*  of  myoeiu  are  precipiiatt<<l  by  alcnho),  and  tlie  precipiiate,  as  in  tbe 
mt  <■•{  otiirr  pn>leid*,  IwennieK,  by  continued  action  of  tbe  alcohol,  alterol 
aa*<\«gulBie<l  imraluble  prnt'-id. 

VTe  bavc  seen  that  par^lobulin.  aitd.  indeed,  any  member  of  the  globulin 
(nap.  b  vciT  midily  changed  by  the  action  of  ilihite  acida  into  u  body 
aSta  'M^-<iANiniN,  chamot^riited  by  not  being  soluble  viilicr  in  water  or  in 
Ah*  Mlioe  aolutions  bul  rciidily  tolublc  in  oiluto  acid*  an<t  nlknli<«.  from 
ili Mladom  in  either  of  which  il  i«  precipitatdl  by  iieutralintion,  and  by 
I  iW  &cl  that  the  sotuliona  in  dilute  aciils  and  alkalies  are  not  ooogulated  by 
tML     When,  therefore,  a  globulin  is  diceolved  in  dilute  acid,  what  lakes 


10« 


piloe  ianota  Di«re  solutioa  but  a  ch^tiiical  change;  the  glMmliM  caniint  be 
got  batik  ft«tn  ihe  eohiliou,  it  h»s  been  chnn^red  iiilo  «ci>l-nlhiimin.  8itn!- 
larly  vhen  (>lubulin  is  diseolvwl  ia  dilute  alkaliefl  it  i?  changed  into  n/^1/4- 
nlbumin :  and  bruadir  B{>eakinK  alkali-albitmin  pr«(npiui«d  by  Deutraliu- 
tion  i-uu  Ite  cbsujted  by  Boliition  with  diliiie  ncidM  into  add-albutuin,  uid 
add-albiiniiii  by  dilotc  mikalies  itito  alkali  albumin. 

Now  my<H>iR  i°  nimilurly.  nixl  even  mure  readily  tlian  is  t;I<>l>"li<i<  M"' 
vertei]  imn  iioidnlbumiii.  niid  by  Ireutiii);  a  niU!«lc,  either  M-BBhe<l  or  OM, 
directly  with  dilute  hy()rrirhli>ri<-  ndd,  the  myiK>in  may  be  c»uveri«d  iaUt 
lt«i(l-nll)uniin  and  duwilvcd  out.  Acid-nlbuinin  oblniucd  by  dit<Milvitig 
riukIo  in  dilute  acid  ux'd  to  be  culled  minlo'iin,  niid  it  uxed  to  Iw  Mid  that 
n  n)u»cl(!  ointained  «ynloiiin  ;  th«  ntURclc.  howcrcr,  contain*  myovin,  nut 
i>yn[iiiiin.  btii  it  may  bo  ueeful  to  retain  the  word  syntotiin  to  drtiotc  nrid- 
klbumin  ohijiined  )>y  iho  action  of  dilute  ncid  on  niyotin.  Jty  ibe  notiun  of 
diluU'  nikniira,  myosin  may  «imilarly  bo  conv«ricd  into  alkali-albumin. 

From  whul  bti«  be«n  above  Hated  it  is  obvious  that  mvoein  has  mnny 
annlofpes  with  fibrin,  and  wg  have  yet  to  mention  eome  Btnkin);  annlocin; 
it  h,  hoirefer,  much  more  soluble  than  librin.  and  speakinf;  generally  it 
may  be  said  to  be  iuterniediate  in  its  charaeler  between  librin  and  clobulin. 
On  keepiuft,  and  especially  on  drving.  its  solubiUty  ia  much  diminislied. 

or  (he  suliaiances  which  are  feft  in  washed  muscle,  from  whidi  alt  ibe 
mvosin  liaa  been  extracted  by  ammoniuiu  chloride  solution,  little  b  known. 
if  iraabed  mii^le  l>e  treated  directly  with  dilute  hydroobloric  a<rid,  a  targv 
p«n  of  the  material  of  tlie  mumle  pattM,  as  we  Imve  it»i<l,  at  once  into  svo- 
touiii.  The  iiuantity  of  •ynctmiii  thuft  ob(«in«<l  may  he  taken  aa  roughly 
rqnwBeniing  tne  ((uantity  of  rayoi>in  provioutly  esi>iting  in  the  mutclc.  A 
more  prolonged  action  of  the  ncid  may  distolrc  out  otlior  protcidf,  l>««i(lei 
inyiMin,  left  afler  the  washing.  The  portion  inxolubk-  in  dilute  hydro- 
chloric ncid  oUNsts  in  part  of  the  ^tatin  yielding  and  otiier  siibelasces  of 
the  wrcolemma  and  of  the  conneolive  and  other  timuos  between  tb«  bun- 
dles, of  the  nuclei  of  thcee  li^eiiee  and  of  the  librw  themselves,  and  in  part, 
possibly,  of  some  |)ortioDs  of  the  muscle  subetsncc  itself.  We  are  not,  now* 
ever,  at  preaeDt  in  a  position  to  make  any  very  deHniie  sutciuent  as  10  the 
relation  of  the  myosin  to  the  Mtructural  lealurai  of  muade.  Since  the  dim 
bands  are  remtereii  very  indiiiin't  bv  the  action  of  a  I"  per  cent,  sodium 
chloride  ^lutinn,  we  may,  |«rli(ni^,  int'ir  that  mvwin  enters  larKely  into  the 
oompooition  nf  the  dim  buul^  mm  I  Ik  relbre,  of  the  librillni;  but  it  would 
be  haznrdimx  to  nay  much  itu'ii;  iluxi  Uu.h. 

^60.  Living  nuwie  may  be  fmiccu,  and  yet,  afYor  osrtnin  precauiiom 
will,  uo  being  ihawml,  n:)^in  its  irritability,  or  at  all  evcnl4  will  for  a  time 
be  fiHind  to  be  still  livinc  in  thu  wiwc  that  it  ha*  not  yot  paavcd  biio  rigor 
iaorti».  We  mayi  therefore,  toko  living  musole  which  has  bemi  froMU  as 
still  living. 

If  liriaif  fttalrnetih  mtuelt,  freed  ns  much  as  poMiblc  from  blood,  be 
frozen,  and  while  frozen,  minc^rd,  and  rubbed  up  in  a  mortar  with  four  timss 
its  weight  of  snow  cunisining  I  per  cent,  of  sodium  chloride,  a  mixlur«  b 
obtained  which  at  a  (em)iernturo  just  below  Q"  C  «■  sulKcienlly  fluid  to  ba 
filter«<l,  thouuh  with  ditfieulty.  '1  he  slightly  opntevcenl  filtrate,  or  wii-"'^ 
plamia  iw  it  in  calleii,  i&  at  tirsl  r|Uile  fliiid,  but  will,  when  exposed 
ordiniiry  lem|HTaliii*,  become  a  solid  icily,  and  afterward  separate  into  a 
e/ol  and Tiiiri.  It  will,  in  fact,  coaeufate  like  blood-plasma,  with  ibis  dif- 
femiK'C,  that  the  clot  itf  not  llrni  and  Rbrillar,  but  Ioom,  granular  and  lloc- 
culent.  During  the  coagulation  the  fluid,  which  before  was  neutral  or 
slightly  alkaline,  l)ccome«  distinctly  acid. 


cnAxose  tn  a  mitscle  Di'itixo  contraction. 


Tlkf  dot  b  mytmn.  It  givn  ill  tbe  raifltioiu  of  myotiit  obtninvil  (Vi)iu 
<1mcI  wnacl*. 

Tb»  «ran  rontaitu  tn  altKimin  -vtry  timiUr  to,  if  not  Hiciitimi  wilb, 
vrtim-mlbumin.  ■  globulin  <)ifl«rin^  ■umi^whiU  I'rDni,  Kn<l  cmi&ulitiiig  at  it 
)<>««r  iMnpvnilun'  ihuD  pn»f;lobiilJii.  mn<\  which  lo  (Itningtiifh  it  IVoiii  tbe 
globalin  uf  bimxl  hiu  bwD  (.-itlleH  mwylohuUn,  eorav  ii|h«r  jiroti-itli'  ohicb 
Dol  bv  (UscHbed  heiv.  and  various  "estnclJTea"  of  vrhifh  nrp  fbaM 
.  dlrectlr.  Such  muscles  as  are  red  also  conlnin  a  buiaII  quantity  of 
[lobtn,  and  of  anotltet  allied  jitgnient  allied  hitlolurmatiH,  to  which 
ptCMaia.  iotlnxl.  Ib«ir  r«dna«  is  due. 

Tkoa,  whil«  demd  muwli'  cunlaiw  myoain.  stbuniiD,  aud  Mber  protcids, 
•ztraetir**,  ami  ccruin  inuluble  nuitten.  in^ther  irilh  gi'laiinuus  aud  oth«r 
wib*anm  Dot  referable  tu  tb^  niUNcJe  Kulmtam-c  iliwlf,  living  mii.*cle  euniaiDe 
OM  aa^Min,  but  aonc  iulwtance  or  •nlwtancr-!'  which  Ixuir  MMDewhnt  Ihf  Mime 
n-Utiun  Kt  mTottn  thai  the  ant««cdfDi»  of  tikrin  d»  to  fibrin,  and  which  jitve 
nM>  lit  BijiMin  u]>nn  iW  denth  of  the  muscle.  There  arc,  imltiHl,  rutuMUis  for 
thinktDff  that  thv  inynHn  ari«c«  from  tlu'  (»nvcnii>n  of  n  prcvioiuly  existing 
bndy  wfiidi  may  be  cntlnl  myMino^fH,  and  that  tli«  c»nvcn>ion  lake*  [ilaee, 
nr  nay  lake  placf.  br  ilic  iiction  of  n  special  fermont,  ihv  L-oovcrsiaii  of 
Byaaaunn  into  inyodin  bein^  viry  analogous  to  the  conversion  of  tihrinogon 
iMfl6bnii. 

W«  nay,  in  fact,  apeak  of  riitor  mi>rtU  na  characieriEed  by  a  con^'nlation 
of  Um  muacle-plasfna,  oomparanle  to  tbe  coaijulation  of  blxod-platmn.  hut 
JUfciny  fWmi  it  inaanucli  aa  tbe  product  ia  ixrt  tibrin  but  myosin.  Tlie 
rijtidliy,  ibe  Um  of  vupplenea*,  iimJ  tbe  diininl»lied  translucency  appear  tu 
Iw  at  kII  e\-«iita  hir;(^lv,  ihotijtb  pn>hubty  not  wholly,  due  iti  tbe  ehunife  frutn 
tbe  lltiid  plMHUt  lo  tlw  tolid  niyu«io.  We  miebl  oonijmre  a  living  imml« 
t"  a  nnmber  nf  fine  tramparmt  ai«nihr«»ous  tnues  containing  plood-pln«niB. 
Wb«9  ihla  blood- plasma  entered  into  the  "jelly"  stage  of  con^ulaiion,  tli« 
mlvin  of  tubffi  would  present  many  of  the  phennmenn  of  ngor  ntortb. 
Tbry  nouM  lose  much  of  their  suppleneaa  and  tronshicrncy,  and  aoquiiv  a 
evrteiB  aoKMinl  nf  rigidity. 

(61.  Time  b.  however,  one  very  marked  and  important  diBereoce  be- 
imva  Um  riffor  mortis  of  muici*-  and  tbe  angulation  of  blood.  Blood  dur- 
bi^  iU  onaipualion  undergot*  n  uligbi  chan^i'  «4ily  in  its  reaction :  hut  mus- 
eW  4ariag  the  oniet  of  rieor  mortis  liec«'nn-  diDlinctly  acid. 

A  livm  muscle  at  n*t  in  in  rcAotiim  miilnil,  or,  pumibly  from  aome 
"TTwfrr  uf  lymph  ailhering  to  it.  fninliy  nlkiiline.  [f,  on  the  other  hand, 
tW  naelian  of  a  ihorunchly  rigid  miiKch'  he  ttvleil,  it  wilt  Iw  found  to  Im 
MCM  (bitlnctlr  add.  This  development  of  an  acid  reaction  is  witueaied  not 
obI/ in  tbe  solid  iiiitotiched  fibre  but  alw  in  expresacd  mttMl»-planDft ;  It 
•MBa  tn  be  awH>etnt«)  in  mmv  way  with  ibc  nppearnnce  of  the  mynstn. 

TW  exst-l  caumtioti  of  this  acid  rcartion  hns  not  iil  urrscnt  brcn  clc«riy 
Mnrknl  utit.  8iuce  the  coloration  of  the  litmus  priwfuccd  is  permanent, 
nrhonir  acid,  which,  as  we  shall  immediately  state,  is  set  free  at  tbe  i<ume 
tine,  rann"!  he  regarded  ah  the  active  acid,  for  the  reddening  «if  litmus 
neoduoril  by  cnrlxxiic  otid  »i)e«iily  dbappean  on  exposure.  On  tbe  other 
Inod  il  ■*  [v>wi)>[i>  ut  rxirad  fnxii  n^'id  raiuKle  a  certain  ououtity  of  lactic 
•did,  or  nuber  of  a  varii-tv  of  lactic  uctd  known  an  urcyilactic  acid : '  and 
il  Im*  baea  thought  that  tdc  appearanoe  of  tbe  iict<l  reaction  nf  rigid  muscle 
m  da*  lo  ft  new  jbmation  or  to  an  increased  formulii>ii  of  thin  Mrcolacllc 


\MmSX 


■MD  «wMla>  or  lactic  uM.  «Mc4i  ua  iMaatfto.  tiarlaf  thir  midi  ooiDpotflM), 
~    ta(lMltt«HibM>»4  afsddlTlaiheuMSUiyolllKlr  ilMi^ta.    TbomiHty 
tt  dWlatiil«b«d  »  aFMlwUcicU. 


108 


THB   CO,VTKACT[I.K  TISftlTRS. 


a€td.    Then  is  much  U>  he  eaid  io  favar  of  tbia  vieir,  but  i(  cannot  at 
pnaent  b«  regarded  a*  eeiabti^hed  beyoad  dispute. 

Coincident  vvUh  the  appearance  of  tliia  aoid  reaclioo,  tbou^b.  ae  we  have 
said,  not  the  din>ci  cause  of  it.  a  lari:e  development  of  carbonic  add  laka 
place  wbeu  luuscle  becomes  rifcid.  Irrilable  living  muscular  sulutauce.  like 
all  liviii{{  aubittaiice,  in  coutiuually  reapiriiig,  that  h  in  i>»y,  U  cuutirmatly 
consuming  oxyjcun  and  ttiviug  out  carbuiiic  aciil.  In  the  h^dy,  the  arterial 
bkiod  ffoEug  In  the  miia<^^  givt»  up  some  of  its  oxygun,  and  gain*  ft  quiintiir 
of  cartioiiit'  acid,  tliiiii  bccuniiug  venous  iis  tC  puKM*  through  ll>e  iniiwlc 
Cii]>illarit«.  Eviru  nlU-r  rviiioval  IViim  the  bcMly,  the  living  niujclc  coiilinuea 
to  taku  up  front  the  vurruunding  atimifphorv  a  certain  i]uantity  of  Qxygta 
and  to  give  out  n  certain  quantity  ut'  carbonic  acid. 

At  the  onset  of  rigor  niorlis  there  is  n  very  lari^c  and  nudden  inctvaae  in 
this  production  of  cnrbnnic  acid,  in  tact  an  oiitliurct  n»  it  were  of  thnt  gst. 
Thi«  ia  ft  )ihcn(imeiion  dcecrving  suecinl  atlcntioii.  Knowing  that  the  car- 
bonic ncid  ivhicb  is  the  outcjiue  ol  the  respiration  of  the  wbole  body  i#  the 
nwult  of  the  nxidatioD  of  carbon-huldiu^'  aubslances.  we  might  very  natu- 
rally suppose  that  the  increascti  production  of  carbonic  acid  atteodaul  on  the 
development  of  ri;>or  niorlia  i»  doe  to  the  fact  that  during  tliai  ereut  a 
certain  quantity  of  the  carbon -holding  cunatituenl«  of  the  niucole  are  sud- 
deulv  oxidized,  llut  Huch  a  view  is  negatived  by  the  following  facl^ :  In 
the  itrst  place,  the  increased  production  of  carbonic  acid  during  rigor  inortu 
is  not  accompanied  by  a  correagxindiug  iucreaAe  in  the  oouauiaption  of 
oxyeen.  In  the  aeooiid  place,  a  iiiuacle  (of  a  frog  for  inhtance)  oontaina  in 
itMlf  DO  free  or  loivcly  attacbe<l  oxygen ;  wheii  subjected  Ut  the  action  of  a 
merctirial  air-pump  it  gives  olf  no  oxygen  to  a  vacuum.  oHering  in  thi*  n- 
•peel  a  marked  contrast  to  bhiud  ;  ami  yet,  when  placed  in  an  atiuodphero 
free  from  oxygen,  it  will  not  only  contimifi  tu  give  off  carboDic  acid  while  U 
rtDiaini  alive,  but  will  also  exhibit  at  the  onwt  of  rigor  mniti*  the  sntne 
incnawd  production  of  carbonic  acid  that  i*  ehonn  by  n  muwlc  placed  in 
u  umoaphere  containiitg  oxygen.  It  is  obvioui  that  iu  »uch  a  caM-  tlw 
oarbonic  acid  does  not  arise  from  the  direct  oxidation  of  the  muscle  sub- 
Glance,  for  there  is  no  oxygen  present  nt  the  lime  to  carry  on  that  oxidation. 
We  are  driven  to  suppose  that  during  rigor  mortis,  some  complex  body,  con- 
taining in  itself  ready  formed  oarbonic  acid,  so  to  speak,  ifl  split  up,  nud 
ihiii  carbonic  acid  is  «t  free,  the  process  of  oxidation  by  which  tliat  c«r- 
I>onic  acid  was  formed  out  of  the  cnrbou-holdiug  ooustitueuta  of  llie  musol« 
haviuK  taken  place  at  some  anterior  date. 

Living  reitin;:  mo^de,  then,  in  alkaline  or  neutral  iu  reaction,  and  the 
subdtance  uf  iia  tibrtu  contains  a  coagulable  plasma.  Dead  rigid  muscle  on 
ibe  other  hand  in  acid  in  reaction,  and  no  longer  oouiains  a  ctiagulablc 
jiliunui,  but  in  laden  with  the  Kolid  mrosin.  Furilier,  the  change  from  llie 
jiving  irritaldf  condition  ^>  that  of  rigijr  mortis  ii>  accomjninicd  by  a  largv 
and  Kudden  dcrelopnicnt  of  cjirbonic  aoid. 

It  is  found,  mortvover,  that  there  is  a  certain  amount  of  {wrmlleliMa 
between  the  intcnsitv  of  the  rigor  mortis,  the  degree  of  ncid  rcucUon  and 
the  (quantity  »f  cnr^lic  acid  given  out.  If  wc  suppo«e,  h  wo  fairly 
mny  do,  that  the  iutensitr  of  the  rigidity  is  dcpeiidunt  on  the  minntity  of 
myosin  defweileil  in  the  fibres  and  the  acid  reaction  to  the  development  if 
not  of  lactic  acid,  at  least  of  some  other  subslanoe.  the  parallelism  betircvn 
the  three  products,  myooin,  acid-producing  substance,  and  carbonic  acid, 
would  suggest  the  idea  that  all  three  are  the  I'c^'ulls  of  the  spliiting-upof  the 
•ante  highly  complex  sulwumce,  Xo  one  has  at  present,  however,  succeeded 
in  isolating  or  in  otherwi*e  ilelliiiti-ly  proving  the  existence  of  such  a  twdv, 
and  though  the  iilen  teems  tempting,  it  mny  in  the  end  prove  lotally 
erruiwAus. 


CHA\OX»   IN    A    Ht'BCLR    l>VRI.VO   CONTRACTION.       109 


I 
I 


I 


I  n.  A«  to  ttie  nlh«r  prnteids  of  tnuscle,  such  ts  the  albuiDin  and  the 
yMmHa,  we  know  as  yet  »i>i)iin);'  rotmrning  tl>e  parts  trhich  ihey  pUv  and 
Um  elMBfe*  wbicli  they  undergo  in  itie  livii))>  muscle  or  in  ri;;<>r  morti*. 

Biriiu  the  Jot  which  ta  found,  and  that  nat  iiofre'iiienilr  in  nbundnnce, 
in  ibe  cunnectira  tiaane  between  the  fibres,  there  is  also  ptva^ut  iu  the  tnu«- 
cwkir  aalMtance  wiibin  ihe  MircoIeRtniA,  Kluays  n-jme,  and  at  timea  a  Krout 
AmX.  of  fat,  chieflv  ordioary  fai.  vii..  Mearin,  [Mlmitin,  and  olein  iu  variable 
pfopcwtioo,  but  also  ihe  lUAfe  complex  fat  K-Htbtn.  Aa  Iu  the  AiDdivn  uf 
tba*  arvwrKl  &ta  in  tite  life  of  the  minwle  ne  Icm-w  little  or  nothing. 

OKtiwkfiimtm,  ibe  third  of  the  (hre«  grnit  claiuu-ii  in  which  wc  may  ^ruup 
Um  CBVfgy-boldhlK  aufaMJUtcea  of  which  thi?  animal  body  and  it.-<  t<icid  an- 
alike  cunpcMil.  tic,  proteidit,  &(,  ami  mrbobydrat^-M,  are  rvprvMMite<I  in 
iBUfcle  bjr  a  nvculinr  body,  ^yerHjm,  which  n'l-  »hiill  bnvi'  to  xtnily  in  detail 
btarno.  ^\«mu•t  here  nK-rely  wiy  Ihnt  glyoogrn  i»  a  Ijorly  cIiKwIy  iillicfi 
bt  March,  haviae  a  formntn,  which  may  Ix-  included  under  the  gt'iH-ral 
(maola  fi>r  ■taroMS.Jr  (C,H,,0,),  and  may  like  it  be  c»nverled  by  the  af-lion 
i>f  acwl*.  ur  by  the  action  of  paniculnr  fermente  known  as  amvlolTtic  fiT- 
Mtnta.  into  Mtme  form  of  Migar,  dextruee  (CiH|,0,).  or  some  allied  sugar. 
Maoy.  if  not  nil.  living  niMM'lee  contain  a  ivrtain  amount,  and  some,  under 
rartaia  eircuniiitances,  a  cun^idcrable  amount  of  glycoceu.  During  or  after 
tianr  lawiiu  this  gtycoji;eo  is  very  apt  to  be  converted  into  dcitroee,  or  an 
uBed  angar.  The  mnsclea  of  Ibe  embryo  at  an  early  trtage  contain  a  relu- 
ilnslj  eoonnoas  quantity  of  KlvcuKeu,  a  fact  which  attgi^iB  thai  the  xlycn- 
fun  M  moacle  n  carbohydrate  jood  nf  the  u)ii$cle  about  to  be  irruuglit  up 
nto  the  living  muBcular  »ulMta»ee. 

TW  bodica  which  we  have  calle<l  ejrtmefiftt  are  numerous  and  varied. 
TImt  art  wpeciaily  intcrettiiig.  since  It  lecnis  probable  that  they  uru  waite 
y€vaaeU  of  the  mclabniigm  <>r  ihc  niui>ctilar  subsianoe,  and  the  study  of 
then  BMT  be  expected  to  throw  light  on  the  chemical  change  which  luus- 
cabr  MiHtance  nndcrgno  during  life.  -Since,  as  we  shall  see.  musctilar 
wbaianea  forms  bv  far  the  grniter  part  of  tlie  nitrogenous,  that  is.  proteid 
poetioa  of  the  body,  ihe  nitrogenous  exlraclix'cs  of  muscle  demand  peculiar 
attratioci.  Now  the  body  urtti.  which  we  i^hall  have  to  study  in  detail  later 
«a.  &r  nceetis  in  importance  all  the  oiher  nitrot^nous  extractives  of  the 
body  aa  a  whole,  since  it  is  practically  the  one  form  in  which  nitrof^noiis 
WHCaa  loves  the  body;  if  we  include  with  urea  the  cineely  allied  uric  add 
(whieli  for  present  pur]Kisee  may  aiuiply  lie  regarded!  as  a  varietr  nf 
Br*w>.  we  mny  «ay  that  all  the  nitrofren  taken  in  as  food  sooner  or  later 
kav(*  tlw  body  aa  urea;  cumpari-d  with  ihii>  all  other  uiiniKcnoua  waste 
ifarown  out  from  (be  bwly  is  Inugnittcant.  Of  the  urea  which  thus  leaves 
iIm  bodv,  a  iv)fiuderal>le  portion  must  at  sonic  time  or  other  have  existeil,  or 
M  afaak  more  eiactly.  ilK  nilrogi'ii  niLj»t  hiivi;  i-xlHtcd  nx  the  nitrogen  of  the 
pnMMa  of  nnsailar  ntulMtan (.■.■.  Ni-vrrthi-liiu.  no  un-n  nt  all  I-",  in  unrmal 
modltkaa.  pieaent  in  muncular  subvlatm'  citht-r  livinj,'  and  irritabli'  or  dead 
aed  rigid:  un-a  iiin-»  not  arise  in  muK-uIar  Milxitanix-  il»ell'  ns  oik-  of  thir 
tMS0adiat«  waste  pniduct*  nf  miiu-ular  Mibstance. 

Tbfvc  ia.  however,  alwuyi^  prrat-nt  in  relatively  considerable  amount,  on  an 
avvfkp  ab(«ut  U.'i.S  |)er  ocni.  of  wet  muKclc.  a  remarkable  body,  trrttlin.  Tim 
■^  in  one  sense,  a  comtmund  of  urea  :  it  may  be  split  up  into  una  aiul  sar- 
aain,  Tbia  latter  iKMiy  is  a  methyl  glycin,  (hat  w  to  say,  a  glycin  in  which 
lilbyl  has  li^n  substituted  for  hydrof^en.  and  glycin  iiwlf  is  nmido-ncetic 
acid,  a  ctiit)j>ouud  nf  amidof;en,  that  is  a  repre«entntive  of  ammonia  anil 
MStie  acid.  Kence  kreatin  oinlaint  urea,  which  has  close  relations  with 
uaasunia,  toi:ethcr  with  another  r>>prefentative  of  amniDnia.  and  a  surplus 
«f  carbna  and  hydrogen  ermnj[ed  as  a  body  beloDgitig  to  the  ftilty  acid 


110 


TUB  CONTRACTILK   TISSCSS. 


•eriM.    Wc  sIiilU  I>nvc  to  reUiru  Lo  th!«  kn>iiiiii  niid  «ondd«r  its  nktioo ' 
urra  und  Ui  muiidi.-  nhcn  wc  oome  lo  deal  with  urine 

The  oilier  iiiir<?gciiou»  oxirnctivcH,  •ii>:)i  hn  kcniiD,  lij'puxanthiti  i.or 
earkin),  xaiilhiti,  luuriii,  vtc,  ix-cur  ill  snitill  ijutiiitity.  nnd  a<xii  not  be  dvelt 
00  here. 

Anibug  Doii-tiitrog«iiouB  extractives  the  most  important  is  th«  sarcolacUc 
ttcid,  of  which  we  hiivo  nircndv  i^pokcii :  to  this  may  be  added  sui^ar  in  sonie 
fom  OT  other  either  cumiDt;  Iruni  glvcogeo  or  from  fome  other  eoun.'e. 

The  nsh  of  muscle,  like  the  a^ii  ol'  the  blood  corpuscles,  and,  indeed,  ihe 
usli  of  the  tiMueti  in  frenersi,  ea  dUtini^'uighed  from  the  blood,  or  idasma,  or 
lyin)>b  on  nhich  the  tit«ue«  live,  i«  charBct«riz«d  by  the  nrepon<IeraD(«  of 
|Mlai«iuni  aalt>  mid  uf  phufiphates ;  these  form,  io  favt,  nearly  dO  per  ceut.  of 
ihe  whoh)  a«h. 

j  63,  Wc  may  uuw  past  on  to  the  queetiou,  What  art  the  chemicsJ 
cltnnges  which  take  pbive  when  a  liviii^  nstinK  mutcle  entvn  into  u  conirac- 
linn?  Tbcw!  clioii^  arv  mou  evident  otW  Uie  inuwle  hait  been  aiibjcc 
lo  a  proloDgcid  lotuiiu.i ;  hut  there  CUD  be  no  doubt  that  the  chemical  mt 
of  It  li'Miiiiii'  lire,  likd  the  pliysimi  eruiU.  dimply  ilie  itum  of  the  multa  31 
tliv  iiinstitiivnt  »ingk-  contraolioiiK. 

In  iho  tint  tilnci.-  llii?  niii«cl<-  bcconicai  add,  nol  so  ncid  ait  in  rigor  luortia, 
but  Etill  Huttiuiciilly  so  Hl\cr  n  vigorous  tetanus  to  tiini  blue  Ittmtis  distinctly 
I'ed.  The  cause  uf  the  acid  roncUnn,  like  tbnt  of  rigor  mortis,  is  doubtfiil, 
but  is  in  all  prubability  the  same  in  both  niiK-s. 

Ill  the  secoDr]  place,  a  coDsidvmblc  (lusnlity  of  cnrbonic  acid  if  set  free; 
and  the  prodtiftioii  of  carbonic  ncid  in  muscular  ooiitrsction  is  ullogetker 
»iiuilar  to  the  produeti'iD  of  carbonic  acid  during  rigor  niorti§ ;  it  is  not 
accompanied  by  any  corresponding  increiise  in  the  consumption  uf  oxygen, 
lliis  n  evident  even  in  a  muscle  through  nhicb  the  circulation  of  blood  k 
villi  going  on  ;  for  though  t)ie  blond  pawing  through  a  coutractliii;  muscle 
gives  up  more  oxygen  ihaii  the  bliHHl  piu^iug  through  a  iwting  idukcIo,  the 
incmsi-  in  the  aioounl  uf  uxyj;en  lukitu  up  futlii  bu-luw  tlie  incruuc  iu  the 
carbonic  acid  given  out.  But  it  is  ntill  more  mnrkislly  nbowu  in  a  muscle 
removed  from  the  boiiy ;  for  in  «uch  u  muscle  both  tUv  coiitiuctioii  and  the 
incr^-iisr  in  tbc  |)roduclion  of  (rarbonii-  sciil  will  go  on  in  the  absence  of  oxy- 
gen. A  frog's  muscle auapeodetl  in  an  ntnioxtdurc  of  uilmgcn  will  remain 
irilable  for  some  condderable  time,  and  ut  cttcfi  viguroua  letauus  an  incrcaee 
in  the  pruductiou  of  carbonic  ncid  may  bo  readily  nsccnaincd. 

.Moreover,  itiere  seems  to  bo  a  con«spood«ncc  between  the  eoeivy  of  the 
cootraotiou  and  the  amount  of  carbonic  acid  and  the  degree  of  aoia  rewition 
produced,  so  that,  though  we  are  now  trending  on  somewhat  uncertain  ground. 
we  are  naturally  led  Ui  the  view  that  the  emcntial  chemical  proc««  Ijing  at 
tJkc  bottom  of  a  mu»cular  oontraciion  as  of  rigor  mortis  is  Ihe  spliliiug  up  of 
some  highly  eomplex  subtlaaoe.  But  here  the  reBemUaooe  between  rigor 
morlio  nnd  cootraclion  ends.  We  have  no  satisfactory  evidence  of  the  formii' 
lion  during  a  euutraction  of  any  lio<Jy  like  myonin.  And  thb  dilference  in 
cJiemical  nwilu  tatlii-n  with  an  iniiuirtant  dilfereuce  between  rigid  muscle 
nnd  contracting  niunclc  The  rigid  mUHelc,  ui>  we  have  seen,  heeocuca  leas 
extensible.  IcMs  ehistic,  IcsN  (nin»hiii^it;  liic  i-outraoting  muscle  remains  no 
less  transhicenl.  elastic,  and  extensible  ihiui  the  renliug  muecle,  indev<l,  there 
arc  rmsons  for  thinking  that  the  muscle  in  couLraeting  becomes  actually 
more  extensible  for  the  lime  being, 

But  if  during  a  eontmction  myosin  is  not  formed,  what  ehaiigm  of  protcid 
or  nitrogenous  matter  do  take  place !^     We  do  not  know.     Wc  have  no  evi- 
dence that  kreaiin,  or  any  other  nitrogenous  extractive.  Is  incmaaed  by 
coniriictioD  of  muM-le ;  we  have  no  evi<ience  of  any  nitrogen  waste  at  all 


CIIASOX!*   IN    A    XrSCLB    UCRINO   COrCTRACTtON*.       Ill 

alt  of  n  coHtmcUun ;  nnd,  indiml,  ii»  w  thmlt  MC  Ulvr  oil,  thv  tlxidy 
ih»  wsiUr  prodiiCU  of  lti«  body  iw  it  whulw  Icjid  u«  lu  believe  that  th« 
wtgy  of  ifav  vnirlc  don*  by  lb«  qium-K-*  of  tho  IkkIj:  oo«im  from  the  polpii- 
tU  —Brgv  (if  ckHmo  ronitwundi.  mid  noi  of  nilngcQ  ootupounds  »1  all. 
Bat  la  ihi»  point  wv  aha)!  hnvv  (o  return. 
^     t  M.  \V»  nay  ram  up  the  elt«tnistrr  of  muscle  somewhat  la  follows ; 

Duriae  lift  tbe  tnoKtilur  eubetuDcc  is  contiDually  taking  u|>  from  the 

|blo«Ml,  tnat  ta,  from  the  lymph,  protcid.  fatly  and  catb'ihydraie  lunterinl, 

[■■IbM  iMrttMv  and  oxyneo;  theiw  it  huihU  up  into  itself,  bow  we  do  itol 

kutxB.  aod  Ml  forms  ih«  peculiar  moipiei  liviBg  muscular  aubstaui-«.     Tlic 

[•srnct  oalure  of  tiita  liviu|{  Kibataoce  ii  unknown  to  us.     What  «f  do  kium 

1 1»  tbkl  it  ■•  largely  coiojw«ed  of  nrateid  tuaterial,  iiud  Ihai  kucIi  budir*  nx 

■jwiBogni,  inyogloUiliD.  aud  nlbumin   have  voitieihiug   to  do  with   tiitt 

J  of  it  up. 

DBrtei  nU  tlito  muscular  »ubiilan<<e,  while  litkiiijc  in  nwl  building  ilMilf 

ttwtNiI  of  ur  by  moiiwof  tl»eabov<:-iuentioiii;il  malvtiiik  is  cHuittiniaily  giving 

wC oubaair  acid  ami  cootiounlly  funniug  nilmgvnouN  wnrtv  tuch  as  kmtin. 

It  kW  prubably  );iTiH  oB*  aofoc  amount  of  wireolactic  a«-id,  and  poMibly 

aiimr  DOD-nitngMious  walite  m«tlvn>. 

I>unng  n  oontractioii  therv  '»  »  gn-ut  incrawv  of  carlmnic  acid  given  ofl' 
<i(  nlbvr  Udte  acid  ur  some  other  stibstniitv  giving  rise  to  an  ncid  reiioltun. 
•  pvaUr  oonmiraptimi  of  oxygen,  though  the  inereaau  b  nut  equal  to  the 
inercaM  nf  rarbonic  nvid,  but,  a»  far  as  wi>  can  lenrn,  no  inereflse  of  niin^ 

During  rigor  morti*  there  is  n  siniihir  increiised  produelion  of  nirhorno 
lad  and  of  some  ulhfr  ucid- producing  sttlielaDte.  uccM(ii|)iuite<l  by  a  remark* 
■Ut  OMivcrwoD  of  myoeioogen  into  myoeio,  by  which  tbe  ngtdiiy  of  iht 
iW  Ibre  u  brought  abouL 

Thermal  Chaugt*. 

I  tt.    Tbe  cbemical  cbangce  durin)*  a  eontractivu  set  free  a  ijuuititr  of 

n,  but  only  a  portion  .if  this  eoer^ty  appeart  in  (be  "  uork  done."  a  nm* 
Ir  portion  lake*  on  tbt  form  of  heat.    TbouKh  we  shall  hav«  her«*ncr 
klnat  ibis  subject  more  fully,  (lie  leailiui;  (kcu  may  be  given  here. 

Whenever  a  muscle  Diolracts  iln  teinjwnitiire  rixa,  indicating  thai  hwit 
iip^'u  iiul.  When  a  mercury-  tltenDOnieber  ia  plungml  into  a  maaii  of  mus- 
dbb  lucb  n«  tl>Me  of  tbe  ibijih  of  tlw  doff.  ■  rbe  of  the  nitfrc-ury  is  nliKrmt 
lpNilki>  muscl««  Wing  ibrowo  into  n  prolonged  miilnii-timi.  More  exact 
Mlltt,  b«iir«T*r,  arc  olxuimil  by  inean:i  of  a  thcriii'miii.-.  by  tht  h*lp  of 
■Uik  tb«  ritv  of  ifin|>*-mtur«  caused  br  a  ft-m  repeau-<l  linglc  coniriictKHW, 
* illiiil  liy  a  Mngli-  oinlractlon,  may  be  obMrvnl,  mid  the  anioiuit  of  beat 
fina  nut  approximately  mcainrcd. 

TW  tlMnnO]Mle  may  mniiit  either  of  a  linjili'  junclion  in  lh«  rorm  of  a  awdlfl 
fAuffd  lain  tbe  aubstaucc  of  the  iniuctr,  or  of  levtral  juiiciiuuB  riihcr  in  tbt 
4if«  of  a  Hal  surCkce  carefully  o|>pMed  to  llie  surrai-i.-  ot  muscle  (ibeiHle  being 
IMMcvd  ao  »•  to  move  irilb  the  r<>iittnctiiig  inuRcIc.  and  thus  to  keep  tn«  ctiniact 
■net),  or  )a  tli«  «taap«  of  a  IhiQ  nr<)j(«.  ih«  edge  of  wlilcb  coraprininc  the  aciiisl 
jactHMM.  U  ibnwl  into  a  maiu  i>f  musctM  and  add  in  poaitioo  by  ilirm.  In  stl 
OKI  lb«  Hrllow-juBctlon  or  juoutions  must  be  kept  at  a  coostaui  lemperature. 

AaolJwr  lielliala  mMlwd  of  dfteraiining  the  cliBiiirea  of  tempernluTe  of  ■  Ihsue 
■  haMd  oiHKi  tli4>  nMunrancnl  of  altera tions  in  electric  reumanci-  which  a  (iii« 
•V*.  in  contJM-t  vitb  or  plunged  into  tbe  ibauo,  ondrrgoca  u  (he  temperature  of 
a»  timam  ehan|tM. 


us 


TltK    COXTBACTILE    TtSSl'ICS. 


It  has  b««n  oJeulsUtl  that  lli«  beat  given  out  bv  the  inuwl«ii  of  the  thigh 
ofn  frog  in  n  single  cantrnt-tii)!)  knitHiiiU  Ui  3.1  mifrt>-unibt  of  heat'  f!ir  Mich 
frrnmine  of  tnll3Cl•^  lliv  n^ull  lieinK'  dbuiinM]  b):  <livii]iiii;  by  five  the  UAu\ 
BRintiiit  of  Itviit  givcu  utit  in  tive  micct'K'tve  finite  contracliuDit.  It  irill,  bov- 
vvrr,  bo  iHtri.-r  U>  rcKnnl  llitw;  figiin.-'  nf  illustmtivc  of  iht*  fnct  ihiit  tbr  hmt 
Kiven  out  ti  coiinmcrablR,  riithcr  thnn  il*  diita  iSir  clnbc>ml«  cnlnilaiiiiii«. 
Sloreover.  we  have  no  wtiidacUin,'  (iiinnlitmive  ilcl«trriiiiiiilifnw  of  ihp  heal 
i;iven  out  by  the  miwi-lc*  of  warm -blood  ei  I  ntiiiiinls,  though  there  can  !>e  do 
<li>ubt  that  it  is  much  grenter  than  thai  given  out  by  tbe  mii«cU'«  of  the  I'rog. 

There  cait  hanll}*  1k^  imy  •luiibc  that  the  heat  thus  M>t  free  is  the  product  uf 
chemical  ehanges  within  the  rniiscle — elinngcs  which,  thotigh  (hey  cannxt  for 
tbe  reiiBonH  given  above  (^  Hli )  he  regarded  na  simple  and  direct  oxidatioiu, 
vet,  since  they  are  procoaees  dependent  on  the  antecedent  entrance  of  oxygen 
into  the  muicle,  may  be  spoken  of  in  general  terms  aa  a  ooiubtiHliuD  :  eo  UuU 
the  muBcle  mny  be  likened  to  a  Bieam-eagiue,  in  which  tbe  cotubuMinn  of  a 
certain  amuiini  of  material  gives  riae  to  the  development  of  euer^y  in  two 
fornu,  as  beat  and  aa  movement,  there  being  certain  (guautitativt-  relntiont 
b«iw«ein  tbe  amount  of  energy  aet  free  aa  heat  and  ibat  giving  ria«  to  nio^H 
ment.  We  niual.  however,  carelVilIy  guard  ourselree  again»t  prewin^  **^^| 
nnnl'igr  too  cluaely.  In  the  steam  engine  we  can  dialiugiiish  clearly  bi'iwe^^ 
tbc!  fuel  wliich,  ibruugh  ita  i-onibiiMi<in,  i.i  the  ^ilc  source  of  energy,  and  the 
niachiiK-.ry,  which  is  nut  ci>DHUiued  to  provide  miergy,  and  only  wfl^rx  near 
nnii  ii-ur.  In  the  muscle  ne  cannot  with  certainly  at  nrnent  make  eucb  a 
dittinclion.  It  may  t)e  that  the  (■bimiiciil  ohaiigea  at  tlio  bottom  of  a  con- 
Imi'iion  do  not  involve  ibc  real  living  mnlcrinr  of  the  librr.  hut  only  tome 
»iib»lnncc  muniifactun^d  hv  tbe  living  miitcrial  and  loifgi-d  in  unmc  way.  wc 
do  Dot  know  how,  in  th«  living  mnterinl.  It  may  be  that  when  a  lihre  con- 
tracia  it  i«  this  niilKitann-  vrilhin  the  fibre  which  explode^  and  nut  tbe  fibre 
it»elf.  If  we  further  suppose  that  this  substance  is  some  complex  oouipound 
of  carbon  and  hydrogen,  into  whivh  no  nitrogen  enters,  we  ■ball  have  an 
explanation  of  the  difScuhy  referred  to  above  ($6''J),  namely,  that  tiitro- 
geninrs  waste  is  not  increased  by  a  contraction.  The  special  ooiitractiie, 
carbon -hydrogen  substance,  mav  then  be  compared  to  the  charge  of  a  gun, 
the  products  of  its  explosion  being  carbonic  and  .'tfircolaciii'  acitbi,  «  hilc  the 
real  living  niutennl  of  the  fibri;  may  be  conipun-d  lo  the  gun  itwif,  but  toa 
^n  which  itm-lf  is  continually  nnd*-i^iing  <'hHngv  farlK-yimd  nH-re  wear  and 
tvar,  among  the  prnihiclH  of  which  chnnge  nitrogcnouH  bniiirx  likr  krcntin 
an-  convpicuou*.  Thi»  view  will  cortuinly  explain  whv  krealin  ir  pot 
increii«'il  during  the  cr.ntmclinn,  while  the  carbonic  and  lactic  acid*  are. 
Hut  it  must  be  rcmi'mhcn-it  ihnt  wicli  n  view  is  not  yet  proved:  it  ninr  be 
the  living  tnnurial  <>f  \hv  fibre.  n»  n  wliole,  which  is  continually  breaking 
down  in  nn  expii.uivc  ihroniposition.  and  as  continually  building  itself  Dp 
again  out  of  ihc  nmicrinl  supplied  by  the  blood. 

In  a  steam-engine  only  a  certain  amount  of  the  total  potential  enerj^'  of 
the  fuel  issues  as  work,  the  rest  being  lost  as  heat,  the  proportion  varying, 
but  the  work  rarely,  if  ever,  exceeding  oue-tenib  of  the  total  energy,  and 
{{^nerally  being  Icm.  In  the  case  of  the  muscle  we  are  not  at  present  iu  a 
pcsition  to  draw  up  an  exact  equation  between  the  latent  energy  on  the  o«e 
hand,  and  tbe  two  forms  of  actual  energy  on  the  other.  We  have  renson  to 
think  that  lh<-  pi-oporlion  l>etneen  heat  and  work  varies  conxiilerablv  under 
dil1er4-iit  nrcumi'lanct'S,  the  work  .viiiit-iinm  ri*iiig  nn  higti  u*  nne-fil^ti,  itoni^ 
linu-H  poi>»ihly  »inking  na  luw  an  one  twenty-fourth  of  tn<i  total  energ}' :  and 

t  llicnurTO-aiiltlieliiiBiuliliKraiiiiiwiir  uAtor  mlud  one (legTM OnlicmW. 


CRAN'OKS   l>;    A    UrSCLK    DCItlXO   CONTRACTION.       118 


ohMwatiow  kcoi  to  afaow  that  ihe  );reat«r  tlie  reebtaooe  wlikh  ilie  iuu*c)e 
ham  to  overconw,  llie  larger  Uie  proportion  uf  the  total  energy  exneiidnl 
wbieb  ifMS  out  as  work  done.  The  niuscle,  in  fact.  »eeiiid  to  be  no  tor  M>]r- 
nyntMia^  that  lii«  more  work  it  liua  tu  do  tiie  greater,  within  oertaiQ 
U^la^  ii  tbe  eranomir  with  whidi  it  mirksL 

I^tfdjr,  il  niuM  be  ren>eu]l<«n-<)  that  the  giving  out  uf  h«at  bj-  the  niuti'le 
h  Bot  eanfioeil  to  the  oocOAiunii  when  il  U  nclitiilly  contracting.  Wbeii,  at  a 
laMr  MrioH,  no  trval  of  tho  bent  of  tbc  body  gcnenUIy,  Gvi(lciK.<o  will  Iw 
bnMgDt  furwonl  that  lb«  niuaeltis,  «vi-ti  wbrii  at.  rent,  are  giving  ri««i  to  Iwtit, 
•o  thftt  tW  bmt  giYOO  out  at  a  contraction  is  not  some  wholly  new  plHiiion- 
MKwi,  but  a  t4-inporary  exaggeration  of  what  is  conlinually  going  on  at  a 
mon  SMble  nU\ 

Elettrieal  Chan'jt$. 

t  M.  Braidoi  ohemical  and  tberouil  cbaiigea,  a  remarkable  electric  cfaango 
ukr«  plaop  wbsMver  a  mutcle  oontnirtA. 

MtmU-eurrmti'. — If  n  muscle  be  rcmovrd  iii  an  onliuary  manner  from 
tW  bidy,  mihI  two  non-polariuiblc  eb-ctrndcit,'  conii«ctc<l  with  n  delicxtc 
plTanomctor  of  many  convolutions  nnd  high  resistance,  bc  plncL-d  on  two 


ri«.». 


■-if 

XoK-FouuusLB  ELsnnoon, 

AOtilM*  tmbti  i.ik>  anulcunkifd  dBc  fllpa  eenMctal  Mil l>  ihvir  tQ-r«t4]TC«i1na;  t.a,ib« 
■M  adfkM*  •■'■Una ;  M  /^  Uk  |4iisi4  fUna-otar:  (',  Itn  torUonof  (he  rtiln>-cli)  |iluf  teqjeH- 
mimmltm^maal  ikviuto;  ihUcuibcwMlitnl  IntDtOTrwiulntfonn. 

piint*  of  th«  surface  of  the  muscle,  a  dellection  of  the  galvanometer  will 
plftM.  iiitlicaiitig  iliv  exiUenwof  a  current  giaasing  through  iliu  gal- 
from  Ihn  uJw  |HMnt  of  the  muMie  to  the  other,  the  direction  uid 
(if  the  ilcHrction  varying  accurdiug  to  the  position  of  iIh>  pcnnta. 
IVe  "  DiUMlr-curivntA  "  thuK  revealed  are  seen  to  the  best  advimtag*-  when 
ijha  nuBck  ebown  i>  n  cylindrical  or  prismatic  one  with  parallel  fibres,  and 
ehm  lb«  two  tcndiiuwis  cndi  ar«  cut  off  by  clean  iuciaionn  at  right  luigles  to 
tha  tottc  axi«  of  the  Riu>i-)e.  The  niusrle  then  presents  a  tntnsvcnH;  section 
I'anlfleulf  at  each  end  and  n  l()iii!ilu<linitl  sur&ceL  We  may  «p«ok  of  the 
luur  as  tieioK  divideil  into  two  c<ium1  \wris  hy  an  imaginary  tmn^crse  line 

•  n«i  CTlt  Mn  MiM^il  •■•enttall;oI*iJlpn(UifindWi<mKi4}nMriMilnG.dl|>|4nCtiilOB  aVarafml 
■iMU^araMMllteiv.  wlDcb  la  tnni  l>  biautlii  into  (»tui«dton  with  the  Dorm  otiDUKtctnr 
•^^  HS  Wtm  a*  MOct  or  •MiiB4t>r  nalMtaeil  vllk  Bunnal  lalliiiQ  clilurU*  (dIuOui ;  It  II 
MIMMM  (Iw)  1)^  ■<<■>'  •■louM  bt  Uii>iniiKhlr  uiul^naM.  TliU  fiinii  ••(  «)«oliDd«  sIt*  iIm  m 
M  MMlaUOn  Uiaii  ^  rfinpU  |<l*Uiiim  "t  miirw  <*t«l(odW  riir  <>1>T  Bllbrai  ■  toaaiKOiUt 
tmmJM.  m  i>M  •nil  tiw  ikaiu.  hIiIpIi  ntOttcr  mu  ob  ibc  iIhuc  iMir  !•  lelul  do  br  tin  Ubdc 
tMbn  <t  •nr  uauM  ottdi  «nppt«  or  plaUiuna  It  Id  IM*lf  mndcM  to  tfrrelop  ■  omont. 

8 


114 


THK    UONTBACTrLB   TISSUES. 


OB  \tB  aurfiioe  called  tbe  "  eiiiialor,"  coDinii)iDK  all  the  [toints  of  tli«  nurfiace 
midws}'  between  Uie  Iwo  end^  Fig.  -il  U  »  iTiajfrauimatii-  represenUUtoD  of 
such  a  muwlc  the  lint!  of/  hvlm;  the  eijuiitor.  lu  «uch  a  iuuhU  iHa  develop- 
ment nf  the  muidc-i-urn-tiU  b>  fiiuinl  to  be  aa  follovm : 

Tlic  grmMvt  lU^HfCltciD  i.>>  (rlntcrreil  wlicn  iiiiu  electrode  i*  [tlacoil  iit  tt>S 
mH-poiiit  or  efjtinlor  of  th«  iiiiiiicic,  iinil  the  o()u-r  ■(  oithtr  cut  end  ;  nod 
the  dedection  is  of  »iich  »  kiml  iw  Ui  xhow  llial  [lotitire  cumnti'  are  con* 
tinunlly  pacing  from  thf  equator  ihrnugh  the  ciilv«noiDe(cr  to  tbe  ctit  end ; 
that  is  to  WIT.  the  cut  end  m  oegntive.  rclnttvi.My,  to  the  equator.  The  cur- 
rents oubdde  the  muticle  mar  Im'  coiisidenxl  as  citmpleled  by  ourreots  in  the 
munefe  frota  the  cut  end  tn  the  equator.     In  the  diagram.  Fig.  'M,  the  arrows 

Fim.u. 


It  ** 


:....---<y 


DTiunjkH  iLLi-ftainini  mi  Ei Jx-nuc  CXnun*  or  Knvi  *m  HtwLK. 

ncliiK  I'Unl]  •lJiiK"""'<*i'c.  «  '■"<}  wrvE  fnca  i4Ma  (dtbator  nmvcorof  ipUMElVk  oxc*)*  IbM  Ux 
(mmul*  ■!  ih*  irsiifircw  MoUon  nnntit  l)c  uliown  la  ■mrre.  Tbt  arron  ihovr  ih*  4l»cUini  or 
the  cumnt  thraiiRli  ili«  Rtlnnoiuolor. 

nti  Uro  oiuiMf-  Tlio  >lNiiim<iil  riirrcrili  kr*  IIuiM  ■hown  by  Uiv  duk  ^m,  U  (Mm  d,  ■! 
F'jUDilnr,  (A  >  iir  lo  y  «l  ibv  ctjl  viiilg,  Tbr  cutn-iil  rrain  <■  lo  c  ii  mmker  than  fram  a  to  y,  (houcli 
bolU,  ■*  nhowo  by  Uip  arrout,  liavi?  the  mhuc  <ILrucUaD-  A  ontfvTkT  [■  hhc>uD  f^gm  «.  ulilob  U  a^U 
UwwiuMur.  tu  /,  wlilcb  la  riiiilior  rmiii  IIih  pr|tiaiar  Tlwcurninl  (In  tniwrloi  (ruin  •  total  In  Um 
ctroiiuIcnnM  10  •  iioint  n«sn>r  the  cralrvur  ttit  inniVDnN  «ecUoii  li  fhmvn  al  tK  Fram  a  to  ho 
t*am  I  lev.  Ibvn  u  do  nunol.  wIuUcbIiM  b; tbo dotlcd Uo 

indicBte  the  direction  of  the  ciirrenU.  If  the  one  electrode  placed  al  th* 
equator  ab,  Ihe  elfecl  ix  tli«  j>aiui?  at  whichever  of  tbe  two  cut  ends,  x  or  y, 
llie  other  ia  placed.  If.  uito  elevtr<ide  renmiiiiti|i  at  the  equator,  the  other  be 
ahiAed  from  the  cut  etid  to  n  sjiot  (c)  noaror  1"  the  eq^iialor,  ihe  current  c"n- 
tioues  to  have  the  >ame  dirn-tion,  but  \*  of  li-s.-<  iotciisitv  in  ]ini|Hirliou  to  ihe 
neameu  of  tbe  elccimde.i  to  each  other.  If  thi'  Ino  efiHclniiltn  be  plactil  at 
nnf<{Ual  diatanceii 'f  and/),  line  n:i  either  «idc  of  the  eijiintor,  there  itill  he 
a  ft<i-hle  current  frimi  the  one  nearer  llie  cquutor  to  the  one  further  oA*.  and 
ih-'  i-urnml  will  be  the  fii-lilcr  the  more  nearly  ihey  arc  «i)ui(li«t»nt  fr«m  tbe 
e<|uiktiir.  If  they  are  uuitv  equidiaiant — as,  lor  instance,  when  one  is  placed  on 
one  cut  end  (jr)  and  the  olher  on  the  other  cut  end  (y)— tliere  will  be  no  cui^ 
rent  at  all. 

If  one  electrode  be  placed  at  llie  circumference  of  the  transverse  seclion 
and  the  other  at  the  centre  of  the  transverse  section,  there  will  be  a  ourretil 
through  the  gntvanomeler  from  the  former  to  the  latter;  there  irill  be  a  cur- 
rent of  similar  direction,  but  of  leas  intensity,  when  one  elecUode  is  at  tbe 
circumftnence  ^g)  of  the  transverse  section  and  the  other  at  8oiDe  point  (A) 


CIIAXQKS   IN    .1    MISCLB   OIRINO   COSTRACTIO.V.       115 


I 


liiwwr  Um  Mntn  oT  Uw  tnimr«TBe  •ection.  In  fact,  Umj  i>ointa  which  nrc 
wtali>tly  DK»l  potitivs  uwl  m<M  atpi\i\i-  to  each  other  »rv  pninl^  mi  tho 
■laaMr  Bod  Um  two  entrw  of  the  imiiovrnH;  HcLton« ;  nnd  t\v!  xMnmty  o( 
iMcnrraot  Iwtwfwi  wijr  trro  pornti  will  depen'l  on  the  rcfpcctivr  disUiu.'c* 
of  tkow  points  front  the  c^untor  and  from  thv  centre  of  thp  ininaveree 


Asilar  currenu  may  be  obserred  nhoo  the  longitudinal  surfiioct  a  not  the 
Datanl  but  an  anificinl  (^ne:  indc«l,  tliev  mar  be  wiuiesMd  Id  even  a  piece 
of  miMcle,  provided  it  be  of  cylindricof  Bhape  and  coropoaed  of  parallel 
6  bra. 

Tb«M  "roiuclft-ctimalB"  an  »o4  mere  transitorv  ourrents.  dbaipi>enring 
•a  aooo  aa  the  circuit  M  cloaeil ;  on  the  contrary,  tlief  last  a  very  c»iiiudfir> 
able  lime.  They  inuM.  Iherefoiv,  be  inaintaiued  by  tome  ehnnjcea  ft<noK  mi 
in  ib«  mDfcl»— bv  continued  chemical  action,  in  fact.  They  diditpjicnr  a» 
tb«  irritabilitv  of  tl>e  muscle  vnniiibi».  and  are  ooiioecled  with  tluBie  nutritive. 
•(>-<k1I**I  vilnl.  rhangtt  whioh  mninliUD  th«'  irrilithility  uf  the  uiusd<^ 

MMclr-cunrntJi  ouch  iin  have  iuM  Ih-<-J)  dcetcribfd,  may,  wu  repeal,  Im- 
nbaamd  in  any  cylindrical  oiumic  niitably  prepared,  and  similar  curreiitJt. 
witb  varialkna  which  need  not  he  diiwuNMtl  litre,  may  b«  aeea  in  miixcUv  of 
imiptlar  aluipo  with  obliquely  <>r  otlii;rwii>c  arranj^ed  fibreiL     And  du  Iioia> 
BfyBMMMl.  to  whom  dliefly  wo  ak  iadfibted  for  mir  knowlcdgv  of  ihcw  cur- 
fOda,  baa  been  lod  to  regard  Ihoni  aji  naCDtinl  and  important  pnifn-nire  of 
KviBr  aitMl^    He  has,  moreover,  ndvanoed  the  theory  that  nnucle  may  be 
WMaml  m  comimMil  of  eledro-motivfl  porticlca  or  mokcules,  Mcn  of 
•hidi,  like  the  niii»cle  at  large,  hiu  n  positive  equator  and  negative  cods,  the 
*hcile  mueele  being  made  up  of  thew  molticulm  in  eomcwliat  the  same  way 
(Ut  ow  an  illuAtralioo  which  must  not,  however,  bo  slrnimil  or  ronsideriKl  u 
ID  Hact  uaej  aa  a  raaxnet  may  be  aupptMed  to  be  mode  up  of  ma^netie  par- 
tick*  each  with  ita  north  and  south  pole. 

Then  aiT  rca«noK,  however,  fur  iDinkinn  that  Uwae  mnscle-currenta  have 
MHich  ftioiUraieiital  origin,  that  they  are,  in  fact,  of  surface,  and,  indeed,  of. 
tnttdal  i>ri);iD.  Wiilcut  entering  into  the  cuulroversy  on  thin  qu««tlon, 
tkUlowing  ini{iorlunt  fai;ti>  miiv  l>e  roeniionnl. 
1.  Vbcn  a  muKlc  in  esamiixsl  wliJle  it  ntitl  relainn  untnjurwl  iiji  natural 
tarminatioDR,  the  cvirrenUi  an*  miii-h  wtmker  than  when  artificial 
•eelioDS  have  Itven  niiuh- ;  ihe  natural  ti-niliiiiiiin  end  is  toM  iMin- 
lit  than  ll>e  cut  guriMc-.  Hut  the  tdnitiiioii.-  end  !>i'rama  at  oneo  Motive 
■km  it  »  dippvHl  in  wnler  or  nci<l— imU-cd,  whi-n  il  i«  in  any  way  injured. 
At  la*  roughly,  in  fact,  a  riiim-Io  in  ln-»led  thv  Ii^m  evident  are  t^>:  nmiicle- 
qratMa:  aad  it  is  maintained  that  if  adequate  caro  be  taken  to  nutinlain  a 
Hsde  in  an  absolutely  natural  condition,  no  such  currents  as  those  we  have 
bndeKribing  cxiM  at  all— llutt  nalunj  living  muscle  is  itotUdrie,  as  it  ia 
olM, 

1  The  surface  of  the  uninjured  inactive'  ventricleof  the  frog's  heart,  which 
iipnrtically  a  mass  of  muscle,  b  isolectric,  no  airrent  is  ubuinod  when  the 
Jwtrodsn  are  placed  on  any  two  points  of  the  surface.  If,  however,  any 
pn  of  the  surface  be  injured,  or  if  Uie  ventricle  be  cut  acroBso  as  to  expose 
tnit  Mirfai.'c,  the  injured  spot  or  the  cuiHirfaeebeooDiesatODoeiaott  power- 
bUf  Mfpilve  toward  the  uiiinjurml  surface,  a  strong  current  being  developed 
•Istfc  fWRt*  thniugh  the  |j;HlvBnoa>elcr  from  the  uninjured  surface  lo  the  cut 
mftoa  or  to  the  ii)iure<T  spot.  Tlte  negativity  thuH  developed  in  a  cut 
wfen  pHMK  ofi*  in  tite  course  of  aumc  houn,  but  may  be  restored  by  making 
tftnb  eat  aiul  eiposing  a  ttvth  surface. 

■  Tlia  ncnaMIr  at  It*  iKIiil  InMtln  will  t*  «(■  NtMsquwilly. 


116 


THB    CONTRACTILE    TIBSfES. 


The  temptnvry  duratioo  of  the  ncgstiriiy  after  injury,  »iiH  its  nae 
opOB  freah  injury,  io  the  case  of  ihe  ventricle,  iii  coutraat  to  the  man  peiv 
inineDt  n«4^[iviiy  of  injured  akek-tal  mUBcle,  U  explained  by  Ihe  diilerenl 
atnivturo  of  the  two  kioda  of  iiiuaole.  The  cardiac  muscle,  aa  we  •ball  here- 
nfWrtee,  is  oontpoeed  of  ahort  fibre-oella;  when  a  cut  is  mode  a  oerlaiii  uuro- 
her  <>f  thcae  fibre-cells  are  injured,  giving  riee  to  negativity,  but  the  injurv 
done  to  them  iao]m  witli  ibeio,  and  is  doi  ]>ropagated  to  the  oells  with  which 
ibcy  nre  iu  otiiituct ;  beuce  ui)uu  their  death  the  uegutivity  and  the  current 
<lisnp|H-ur.  A  friwh  cut,  involving  new  cutis,  pr<Hluces  trtiAx  nQ{«tivitv  attd 
a  new  ciirrtint.  In  the  lou^  librcs  of  the  itkulctal  niimclc',  on  [he  other  hand, 
the  eAbct«  of  thv  injury  nre  ulciwly  ]>r(i|uigut(.il  tiloug  the  fibrv  from  the  fpt>l 
injured. 

Now,  tvhcn  a  mtifcle  in  cut  or  injured,  thu  «ulvtancc  of  the  fibm  dies  at 
the  cut  or  injured  Kurfm^.  And  nmiiy  iihyxinlngivt*.  among  whom  tho  oxMt 
prominent  is  Hertiitnin,  hnvi;  liccii  M  by  ihv  iihorc  and  ulhrr  tact»  to  the 
conclusion  that  muflLlc currents  do  not  cxitt  nalurally  in  unloucbed,  unin- 
jured muBcIetf,  that  the  muHcular  subetanra  h  naturally,  when  livinc, 
isoelectric,  but  that  whenever  a  portion  of  the  muscular  substance  dtea,  it 
becouifD,  tvhilf  dyiii'j,  negative  to  the  living  eubetiince.  iiud  thus  givee  rice  to 
ourreiits.  They  explain  the  typical  curronis  (as  I  hey  might  be  called)  inaiii* 
feM«d  by  a  muscle  with  a  ualural  longitudinal  surliice  aud  ariiticiul  trans- 
vtsna  seotioiis,  by  the  fact  that  the  dying  cut  ends  are  negative  relatively  lo 
the  T«#t  of  ihe  muscle. 

Du  Buis-Heyuioud  and  those  with  bim  ofler  special  explanations  of  tho 
above  facts  and  of  <it her  objections  which  have  been  urKe<l  against  the  thvory 
of  naturally  existing  electro- imilive  moleculea.  Into  theae  wc  cannot  enter 
here.  Wc  mu»t  rest  conlvnt  with  the  atatement  that  in  nu  ordinary  tauacl* 
currents  such  ns  have  been  described  may  be  niln^'sscd,  but  that  atronc 
arguments  may  l)c  adduced  in  favor  of  the  view  that  these  currents  are  not 
"  natural  "  phenonienn,  but  ciwcntially  of  artilicial  origin.  It  will,  therefore, 
be  lie«[  lo  G]>eak  of  them  as  currmU  vf  rest. 

i  67,  Currviitt  of  action.  Xri/atiii!  I'ariitUon  of  the  miuolc-eurmi(.~-The 
c(introvcrsy  whether  the  "  curreui^  of  rest"  observable  in  a  muscle  be  tif 
natural  origin  or  not,  dow  not  atiect  the  Inith  or  tho  importance  of  ibe  fact 
that  nn  electrical  change  takes  place  and  a  current  is  devetii|>ed  in  a  muaclc 
whenever  it  enters  into  a  contraction.  When  currents  of  r«t  are  observable 
in  a  miwclc,  tbtse  are  found  lo  undergo  a  diminution  u|Hm  the  occurrcnoe  of 
a  contraction,  and  this  diminution  is  «{iokeii  of  as  "  ilie  negative  variation  " 
of  the  currents  of  rest.  The  negative  variation  may  be  teen  when  a  miiKle 
is  thrown  into  a  ^ugl^  con  traction,  but  is  must  readily  thown  when  the 
muscle  is  tvianiuxl.  Thus,  if  a  pair  of  electrodea  be  placed  on  a  mitscle, 
one  at  tho  iKjunior  and  the  other  at  or  near  the  transvene  section,  so  that  a 
cousidcmhie  drflectiou  of  the  galvnuonieter  ueedle,  indicating  a  considerable 
current  of  roit,  be  gained,  the  needle  of  (he  galra^»nlt^ter  will,  when  the 
muscle  in  totaniu-d  by  an  interrupted  current  mmi  through  its  nerve  (at  a 
point  too  l»r  from  the  muscle  to  allow  of  any  vscRfm  of  tho  current  into  the 
electrodes  connected  with  ihe  gid vuuo meter),  swing  buck  toward  zero;  it 
Kturua  to  its  original  dcHcction  when  the  tctanidng  curront  is  ^ut  olf. 

Not  only  nay  this  negative  variation  be  shown  by  llie  gBh'anoine4er,  but 
it)  M  well  as  the  current  of  rest,  niiiy  be  used  as  a  galvanic  shock,  and  *o 
employed  to  stimulate  n  muscle,  as  in  tho  experiment  knuwu  aa  "  the  rheo* 
tcopic  frog."  l''or  this  pur|>osc  the  muscles  and  nerves  need  to  be  very  irri- 
table and  in  thoroughly  good  condition.  Two  muscle-nerve  preparations  A 
and  B  having  been  made,  and  each  p!ac»l  on  a  gluss  plate  fur  theaake  of 
insulation,  the  nerve  of  the  one  U  is  allowed  to  fall  on  the  niuaole  of  the 


CHAXOES 


A    MUSCLE    DL'RINO    L'ONTltACTlOS.        !17 


Mh«r  A  in  naeh 


tllBt< 


of  ihe 


I 


f 


Dorve  cotiiM  in  coniaot  witli  tbe 
»|B»tar  of  (bt  mtMcU,  uni)  miutlicr  point  with  one  end  of  the  muBcle  or  with 
•  potat  «t  Utm»  diflBncc  from  (he  oiuator.  At  the  moment  the  nerve  is  let 
fiul  wmI  conlart  mailr,  >  cnireni — vir,  the  "  current  of  rest  "  of  the  mnacle 
A — (Mar*  ibroaeh  (he  nerve;  thi»  nclH  na  a  ittimntuB  to  the  nerve,  and  m> 
CHBMi  ■  mntnicliun  in  tbe  miwcte  eonnecte<l  with  a  nerve.  Thus,  the  muscle 
A  BCt*  a*  »  b«tU!fy,  the  completion  of  the  circuit  of  which  by  means  of  ifae 
Dvrre  of  B  ivrvr^  m  a  itimutua,  eauaiiiK  the  luuftcle  B  to  conlraot. 

If.  while  the  Dcrve  of  JIH  stilt  iu  «<i>nlact  wiih  ih«  musclenf  J,  the  Oftrre 
of  iha  tatMt  is  tetaniied  with  an  inl«rruplcil  current,  not  milir  is  the  muscle 
>'.f  .1  ifarown  into  teunuD,  but  aim*  that  nf  B,  the  reason  heiuft  lu  fulluwa: 
Al  eadi  spasoi  of  which  the  loianun  of  A  ia  made  up.  there  is  a  negative 
Tsrialinnoftberonicle^urreiilor^.  Kavh  negative  variation  of  the  raiitck- 
mrrvnt  of  A  servcB  w  a  >limuli»  Lo  the  nerve  of  B,  and  u  hence  the  cause  of 
m  i|— >  io  the  muscle  of  A;  and  the  stimuli  fotlnwin);  each  other  ra]>i(ltv,ns 
Wit^  imduce'l  hy  the  tvtanit*  i>f  .-1  ihry  miu>t  d<i,  the  spaatus  in  li  lu  wfii<'h 
thtif  giw  rwe  arv  alMi  fuiii'd  into  n  tt'liiniia  in  li.  H,  in  fact,  cuntracl«  in 
banaocir  with  A.  This  csjxTimrnt  rhn-Hr.  that  thi^  negative  variation  ncootn- 
puijriitg  Uw  uianus  i>f  a  mtiKic,  though  it  caiiiei  odIjt  a  onzlo  Kwinir  of  the 
gstvBBonMer,  Is  really  made  up  of  a  scric»  of  negative  rnriations,  each  tingle 
B^pttlv*  variation  corresponding  to  tbe  single  mmxam  of  which  the  tetnotu 
is  RMJa  up. 

Hill  an  circlrical  chang«  may  be  manifeiiled  even  in  cases  nhcn  no  ciirr«>t« 
of  m\  tfsift.  Wo  bare  stated  <§  titi)  that  the  'iirfnci?  of  the  uninjured  inac- 
tive ventricle  of  the  frog's  heart  is  isoelectric,  no  currents  being  observed 
mhta  the  electrodes  of  a  galvanometer  arc  placed  on  two  points  of  the  sur- 
botk  Neveribeleea,  a  tnuat  dblinct  current  is  develo|)e(l  whanenr  tbe  ven- 
tricle omtractsL  Tht*  may  be  (liowa  eitlier  hy  tli«  Kalvanonieter  or  by  the 
ifcwacoptc  flrea.  If  the  nerve  of  an  irritable  musc&nerve  pre]>aration  tw 
Ud  OVCT  a  puMUing  ventricle,  each  beat  i»  responded  to  by  a  twitch  of  tbe 
■MBit  nf  tbe  ]>repar«tion.  In  the  eiue  <>f  onlinary  lausolea,  too,  instances  nocur 
In  wKiefa  It  vetm  impoKiblci  to  rceard  the  electrical  change  niunifniMd 
doriai;  iW  contrmctiun  as  the  mere  diminution  of  a  preexisting  currvnt. 

Acntrdingly.  thuar  who  deny  the  cxb'tence  of  "  natural  "  muncle  currents 
yak  iifa  uidscte  as  ileveloping  during  a  contraction  a  "  currunt  of  action," 
iiiasiniiul.  a«  they  believe,  by  tbe  muscular  sululimcv  nx  it  in  entering  into 
ika  siste  of  cMntraction  becoming  negative  toward  the  muscular  suUtAUC* 
•Udb  it  BtttI  at  rest,  or  baa  returned  to  a 
M(*  nf  net.  In  fact,  they  regard  tbe 
o^pttivtty  of  muscular  sulwtance  as  char- 
KMrwiic  alikeof  beginning  death  uud  of  a 
kfinniiiic  wntraction.  So  that,  in  museu- 
br  onutrartioo  a  ware  of  negativitv,  sturt- 
iag  fniin  the  end-plate  when  indirect,  or 
ran  the  {joint  stimulate*!  when  direct 
ttinolatlon  it  used,  (Huaca  along  the  mus- 
oilat  sabftance  to  the  ends  or  end  of  tlie 
On. 

If.  for  in*t«iioe,  we  tupnote  two  el«ctr>>d«a 
flsml  on  two  ]M>ints  (Fie-  ^'* '  A  and  B  of 
lUt«  about  to  he  slimuTated  by  a  single 
MnctioB-alKick  at  one  itid.  &:fbre  tne 
idmutati'in  the  Hhre  is  tsocleclric,  and  tbe 

Mnile  of  the  galvanometer  dands  at    leru.     At  a  certain    time  alW  (he 
4fvk  haa  been  sent  thmugb  the  stimulating  electrodes  (r),  as  the  ware  of 


|ria.  ». 


118 


THK  CON'TRACTILE    TtfiSUKS. 


OOntraeUon  ie  tmreUilw  down  the  fibre,  iheBecliou  of  the  fibre  beneath  .i  wil 
become  neRnlive  toward  tibe  rest  of  the  fibre,  and  so  negiklive  touard  lh«r  jior- 
lion  of  the  fibre  under  H—i.c,  A  will  be  negative  relatively  lo  /i,  and 
this  will  be  shown  by  a  deflealion  of  the  needle.  A  little  later  B  will  be 
eiiterinK  in  lu  contraction,  and  will  be  beeimihij;  iiei;atiTG  toward  the  rut  of  the 
fibre,  incltidin^  the  \mn  under  A.  wlitee  oefriiciviLy  by  tins  tiniv  i*  iMMinj;  off 
— that  u  t^i  any.  B  will  now  be  negative  towani  A,  ami  ihin  will  be  *nuwn  by  « 
d«declioti  of  Uie  needle  in  a  direction  oppotite  tti  thut  nf  thit  dtiHrciioii  which 
haa  juNt  previously  taken  place.  Hl-iio-,  Imtwcen  two  el«etmil«v  plno(>H  along 
n  fibre  n  uugle  wavu  of  c-ontntnlion  viill  give  rice  to  two  cnrrenli>  of  diKerriit 
phn«c«.  b>  a  <]ipliiMio  diange ;  and  thitt,  indrtsl,  it  finind  to  be  th«  ciwc. 

This  being  ko,  it  i»  obvious  that  the  clectrirni  rcault  of  t^lanizing  a  mutcle 
when  wnvf  tttier  wave  followx  along  each  tibrc  is  a  complex  matter ;  but  it 
it  nmintainedtliat  the  npuurojit  negative  variutioD  of  t«tanuscaD  be  explained 
V  til*  net  mult  of  a  aeriM  of  ourrentfl  of  action  due  to  the  individual  con- 
metioiiE,  the  second  phase  of  the  current  in  each  contraction  being  l«88 
Durked  than  the  first  phase.  We  ciinnol,  hoivever,  enter  niore  fijUf  here 
into  a  discussion  of  this  difiicult  subject. 

Whichever  view  be  taken  of  ihe  nature  of  these  muscle-currents,  anil  of 
tlie  electric  change  during  conlrnction.  whether  we  rei^rl  that  change  lu  a 
"  negative  variation,"  or  as  a  "  current  of  action,"  it  h  iiii|>orlant  to  reruemtier 
tliat  it  takes  place  entirely  during  the  latent  ]>eriod.  It  is  not  in  any  way 
tlw  reault  of  the  dinnge  of  form,  it  is  the  furerunuer  of  that  change  of  funu. 
Jurt  a*  a  nervous  impultw  jiaases  down  the  nerve  to  the  niuicle  without  any 
rbible  changes,  to  a  nicile<iular  change  of  Hoine  kind,  attended  by  no  vtniblc 
cv«nt«  kcniwn  to  u*  at  prment,  but  only  by  au  electrical  chaug«,  rundi  along 
ihe  muscular  fibre  from  the  cnd-phite  to  the  end*  of  the  fibre,  prefMiring  the 
way  for  ihe  vieihle  chungt'  of  form  which  is  to  tuUow.  This  molecular  itivi» 
iblfl  change  is  the  work  of  the  latent  periixl.  and  careful  obaervftlions  have 
shown  that  it,  like  the  visible  contraction  which  foltom  at  its  heels,  travels 
along  the  fibre  from  a  spot  stimulated  toward  iJie  end  of  the  tibrea,  in  the 
Ibrm  of  a  wav-e  having  about  the  same  velocity  as  the  contraction,  TU.,  about 
3  metra  a  eecoud.' 


T^fl  Changes  in  a  Xcrv!  during  Ihe  I\tt»a</e  of  a  Xtrvotu  Impttte. 

g  68.  The  change  in  the  form  of  a  niu»clo  during  itc  contraction  Ua  Ihing 
which  can  be  socl^  and  felt;  but  thr^  chruigoi  in  n  norvu  during  it»  activity 
are  invisible  and  impalpable.  Wo  :^timulnlo  one  i^ml  of  a  oorvc  going  to  a 
muscle,  and  uc  see  this  followed  by  a  cm  traction  uf  (he  muscle  altat'lied  to 
tlie  other  end  ;  or  we  etiiuulnle  a  nerve  still  connected  ntlh  thi.'  central  ner- 
TOUB  ayatem,  an<l  we  sec  this  followed  by  certain  movenKints.  or  by  other 
tokena  which  show  that  disturbances  have  been  set  up  in  the  central  nervous 
•y«teni.  We  know,  therefore,  that  some  changes  or  other,  ooustituting  what 
we  have  called  a  nervous  impulse,  have  been  propagated  along  the  nerve ; 
but  the  clinnges  are  ouch  as  we  cannot  see.  It  ia  paeaible,  however,  to  learn 
something  about  tbem. 

Strveture  of  a  nerve.  An  ordinary  nerve  going  to  a  muscle  is  composed 
of  elementary  nerve  fihrca,  luialogous  to  the  elementary  muiiicJe  Bbree,  rnu- 
ning  lengthwise  nlong  the  nerve  and  hound  up  together  by  oounectlre  tivmea 
carrying  blood vcucls  and  lymphatics.  [Fi>!.  lift.]  Each  fibre  Is  a  long  ro<l 
or  cylinder,  varying  in  diumeicr  froni  U-ss  than  '2  ^  t«>  20  *>,  or  even  more,  and 

>  Iiillw  mttMlnoT  IM  troit :  liui.  u  wrhnTciwri,  tinvlns  pnitubl;  a  lilehsr  vclodir  In  tlie  Inlacl 
iiuniultui  miualM.  wlUilu  lh«  living  boiljr.  ftiul  nryiue  ncKinlliig  w  dttFomitUKM. 


CUAXOBS 


A    Hl'SCLE   Dt'RINO   COSTBACTION.       118 


Um  MTwml  6brN  mrr  uriuigvd  hj  llic  codhocUvo  tissue  into  buiidlw  or  oordti 
■ng  *loDg  tliv  length  of  th«  ti«rv«.     A  largo  n«rvp.  micb  us  thi;  scinlii;, 
many  conk  of  varioiu  uwm;  in  such  b  case  the  t'^nnevtivc  tinue 

(Fib.  as. 


^-^^. 


II.    -   iLiii    NutviorlUii.    IHMuMld.l 
'<<1  Imnnlln'     Kk.  [iruefM  ttom  tW  f^^' 
-  ..iinincciHiUDuoiwwIibtbouidaiitaiMini, 
'IIw  MUiUpaUiv-ltoiM  nbrlla  oT  Um  vmlimvu- 


I 


r*Bi  or  t  6lan»Mi  Of  on  at  mi.  i^i  - 1.  < 
f.  fiMmfllmia.  anwIMIni  ot  ■  nnmtor  ol  r/ 
•MMBB,  t«MtiHlliitolteliil«ttcra(UwliinlFi.i 
«  liMeHa  tolUHMDu  Una*  taweni  tlx  lune-lltinji. 
asB  M»  tMU  cut  KiiaM  ■•  nno  pdn«  oAan  kpicarlns  io  mibMlli  Hut  lunrMlbnB  with  a  olrcU  of 
■taatitiiMinrtl^MUIiaf  Koyuid  BtUW.  Kuuicluoa  DUck!  uT  oaDOCcUw-Ilana  cslliwo  «Ui- 
kiMnlia  ik(  cBdODMUl^ :  r.  twtlouorsIika>liMHl  ) 

krtWMO  th«  fibm  in  eadi  corcl  in  niurc  dolirule  tliun  tliut  trhivh  biodj  Uie 

conlt  tngetlur:  eHch  oonl  bw  n  io<irr  <>r  Iiw»  ilixtiiicl  ibeuili  of  ooitDectlv* 

liwK,  UM  s  BiuilAT  but  MautCT  >l>uitlh  pnit<.-clii  the  whole  nerve.    In  smmDer 

BCTTW  the  oord*  ure  law  ia  atimbcj',  niiu  m  vrrr  tininll  nvrvo  inny  <'i>nHiiit,  to 

to^iwk,  «f  one  corH  irnly,  ihnt  i»  to  mir,  it  )iii»  one  ■•ht^'iith  for  ihv  whi>l« 

■trr*  snd  fine  cnuiivotive  lianie  binding  together  all  the  (ibret  within  the 

ihaUi.     When  n  large  oerre  dividn  or  seoda  oS  brancbea,  one  or  n>ar« 

ofdi  l«va  the  tnink  to  form  tlie  braoob ;  when  nervea  are  joined  to  form  a 

(JbtM,  one  or  more  cords  leavinj;  one  nerve  join  another  nerve ;  it  is.  as  a 

ntioolrwheo  averir sioal)  nerreiedividin;;  neurits  end  into  delicate  twigs 

ihlfivMon  or  brauobing  of  tlie  nerve  i.-  clTccliiil  or  owisled  by  division  of 

(kofrre  fibea  Ifaemaelvea. 

iiulf  all  the  nerve  flbrea  commsiiiK  nn  onlinary  nerre.  Much  oi  that  goiiu; 
(•■naaolv,  Ihougfa  varying  much  in  lhickn«Rf,hav«  thcsiiim' feAturo*,  whlcG 
*it  K  follom:  ^eeo  under  the  micrrBcopv  In  n  ]H:rfvcl1y  frunb  cuadicion, 
■ilkat  the  nae  of  any  n-iig<-nl«.  ivcb  Hbrr  appvan  iw  a  trniuiparcnt,  but 
— iwhsl  reft«etiTe.  and  therofoni  brigb^lonkin^.  rod,  with  ii  shMqilvib? fined 
Mlliiw.  wbii-h  I*  fbnrai!(<-ristteally  double,  Ihnt  is  to  mv,  the «harplinv  which 
■■is  the  iMilude  of  tW  6bro  is  on  nicb  side  uf  the  fibre  ncconiftanied  by  a 
•nttd  UlMplinUlol  to  iliclf  aiid  following  such  gentle  curves  lu  it  fthows, 
hliMher  iu*arcr  thr  Kxii>  of  the  fibre.  This  it  ispokeii  of  as  the  lioubU  eon- 
^^[Fi^.  •i7].  Biiit  is  naturally  more  oouspicuou*'  and  niorv  easily  even  in 
ll>  '":'■■  ritim  ill  the  thinn-T  fibreii.  The  sub^litnm  of  the  fibre  betirMO 
r  conioiir  linos  apnean,  in  the  perlmly  ftvsh  libre.  honiogenMlW. 
U  uw  tiknt  be  inu-cd  ulong  lU  eourae  for  some  little  distnno-  there  will  be 
taaat  intervals  an  appearancw  na  if  the  fibre  bad  been  straiit;!*^''  !>>'  a  Iig«* 
lue  linl  tightly  round  it ;  iu  IransTerse  diameter  is  mddenly  narrowed, 
tal  the  double  contour  lost.  Uie  fibre  above  and  below  being  united  by  a 
■smi*  »hi.rt  isthmus  ouly.  [Fig.  3H.)  This  in  cnlied  ii  awU.  a  ii.xle  of  Kan- 
nrr.  and  ugwu  exaininatinn  it  will  be  found  that  each  Rbrc  is  markitl  regu- 
bth  abmg  its  Im^th  l>v  nodn*  nl  interviils  of  about  a  roillinietre.  If  llie 
Un  kp  vxamtned  with  ^urthrr  am  tbero  will  be  teen,  or  may  l>e  seen,  about 
■iJoay  brtweeti  every  tu-<i  dihIw,  im  oval  nucleus  lying  cmliedded,  as  it  were, 
it  ths  iwiilin*  of  the  librr',  with  its  long  axis  itarallel.  or  nmrlr  m>,  to  the  axis 


IlitlUH  XKHic-nnaL    (UapiUlulKO 

TlilW  of  Ihvin  nn  Hm:  niiv  iif  wlilnli 
It  rvufttHT,  one  of  mIdillliiiE  iMclmta, 

Uilcll,    IHo   nf  whlth   lire   'louUecon 
loured. ui<] oiic  ullhcniiuoiuoiulnnu.] 


KuiVE-rtMS  niuiitVruTioXEavKor  KiiiKii.  aitib 

ACTIOS  or  N'mttTi  or  Sunm. 

■L  Hint  Conani  by  ihlokonvd  ntamtnnv  of  tehwu* 

(uoda  Of  tuttnltfj.    •»,  whiic  iidI»iw)c«  or  sehwim 

rtndKKd  iwnrraniK  liy  flrmrta.  rp.  Crliiiil«t4Sli, 
mIiIcIi  JuiiabciVi.-iiidlnliiH'  tbolvnl  nC  tboaimularM*- 
•tnciliiii  ]<r<-ii«tiu  tliu  tint*  n(  Fiuiiibuuid  ] 


im..». 


IS"' 


."f 


the  primitive  nhealii,  ur  newiletnma.^  Lving  in  the  axiit  i)f  tbiii  Hbeflth,  nnd 
wmetimai  prnjeciinx  fur  ADnii?  <]i»lnn(v  innn  the  torn  end  cifu  fibre,  uhctbt^r 
the  vboalli  b«  diHiifuyed  or  no,  niiiy,  in  JNiniv  ciimoi,  bu  «ocii  u  dim,  nr  very 
luiiilly,  gmuulRr  hitncl  or  tiiriMid,  uboutoiie-thinl  or  bnlf  the  diviivicr  of  tb*, 
fibre ;  ibis  is  the  .inVry/ifftr  (Fig-  39] ;  it  Wcom«« 
](»t  lo  view  n:>  *Fc  trace  it  bftck  to  wboro  the  tibr«  a*- 
Eiinies  n  itoublv  cotilour.  This  nxi»-cyliuder  euio! 
rcAdily  with  ordinary  stiiining  rvaeents,  aod  beiof;  ia 
this  and  in  ulhtr  respects  itUied  in  uature  la  the 
col] -substance  of  a  leucocyte  or  lo  the  muscle-sub- 
slaiicc  or  a  miisciilsr  libre,  hoa  often  been  spoken  of 
ne  pi'otop)iisnilc. 

LyioK  about  Cbo  torn  ends  of  the  Hbrea  mar  be  soea 
drops  or  miiiule  irrt-gul«r  niawtt  rumiirkiible  for  ex* 
bibiiinK'  a  double  contour  Hkv  that  of  the  uerve-fibni 
itself;  and  indeed  drunt of  ihi» double  oo»toun-d  sub- 
stance niiiy  tie  *ecii  i:>«uiiif:  from  the  torn  <<nds  of 
ihu  fihn*  [we  Fig.  .^"].  Treated  with  oeniic  acid 
thew  dn>p«  and  innsaea  are  tltiiiK-il  hlui^;  they  net  as  powerful  reducing 
mgeuts,  and  the  rvduced  o«niiuai  givct  the  black  color.   Treated  with  ether 

1  TMi  Irnrd  ti  fi>  lorrr^frii  it  wit  u-  ili-ri<iir  ilie  ooTtiiocEJvc  iIhiic  iliHtli  wnppins  round  1h«  vbo^ 

nervr.    Iikitti'.  '.  to  iiHi»:.i>iirh  unnloiiiiu  umuiwurmli'niinaini)  nmrl- 

lODinuifiit  lU'  1.  aiialiiay.aml  l»'ii-i;  iiviirlltinau  Unonnxd  (brthalnui  of 

UKnnruuMii  .  1. 1  ^ .  i^  lo  Ibe  Mnxil«iusui  lu  miUEic,  til.,  Uw  ibcuU  of  llw  Stuc- 


buQiuM  or  SrarcTnax  i^r 

UlM'lUTKII  linviM-iiui*, 

I.  !<i«nlclnlDB  nr  ■tintli 

ofMivMitt.   £.  Mnlullaty 

■htaUl.    ^  AilMTUndcrl 


I 


CnA?faE5  JX   A    MDSOLt  DCBTSO   COSTnACTtOX.        121 


or  oUmt  aolreoiB  of  fal  tbejF  moreoTer  tnoiv  or  less  rHidiiT  diswrlve.  Olf 
viontljr  Ik*;  «»  Urgeir  conipcwd  of  fat.  and  we  aliall  ee«  t'tiat  the  fat  com- 
ptmuta  tbeoi  it  of  a  very  eomplex  itature.  Now  a  itei^'e-Kbiv  ahowJDg  a 
double  contour  Mains  black  with  u>n)ic  acvi ;  but  the  MainJoi.'  is  abeent  or 
T«rT  tlt);)ii  wlter«  th«  doubb  couioiir  eeibiM  tw  at  u  turn  end  nr  at  the  Dodm 
vf  kanrier:  llie  axidojrlinder  utainii  wry  slighily  iiidei'd  with  uamic  acid 
•ad  the  abealh  hanlly  at  all.  Su,  nUa,  whi-u  a  trannvfrM:  Mii-tion  la  made 
ihrounfaa  ttfrvt  or  aiwrvvoonl.each  librc  nppmra  i»  K-cliooaou  dark  black 
riog  MrroundiDg  a  niui-h  nwre  fiiinllj  rtninccl  ceoErnl  nrctt.  Furlhrr.  when 
a  (loabl*  cualoiirvd  nrrvr-libn-  i*  tn'^tiwl  with  clhrr.  or  other  tolvciiln  nf  t'lit. 
tbrfluobUconloiit  vntii«h«^«.  and  tht-  whole  tihrc  become*  more  lritnit|)(in-»l : 
Mnt\  if  lurh  a  tibrv,  either  before  or  aft" r  the  trcnimctitwith  ether,  U'Miiincd 
■  itb  oarmtne  or  oth«r  dye.  the  axis-<-y1iiK)er  will  hv  seen  nt  n  nninnl  Itaiid 
or  ihmd  lying  in  the  axis  of  n  tulHitar  upace  dolincd  by  the  tinarilemmn 
wbicb  atain*  only  sliKbllj  except  at  and  around  the  oiiclci.  nhich.  iis  we 
hse*  atan.  an  embodued  in  it  at  inicrvnl».  In  tlie  entire  lihro  the  lubiilnr 
MBcw  between  tbeaxM-cylindcr  and  the  slieaih  is  filled  nilh  a  fnltr  material, 
lae  mrtluUa,  wbirh.  Tram  its  fatty  nature,  bm  Huch  n  refritctive  power  ns  to 
iliit  a  ilonble  contour  when  aeeo  with  Iranaiuilted  ltf[bt.  on  which  account 
6tirr  ii«elfhn»  a  double  oonlour.  It  islhi*  refractive  power  of  t lie  medulla 
b  Kirea  to  a  nerve-fibre  and  atill  more  ao  to  a  biiuale  of  i>en,'e-fibre«  or 
ta  a  wkoJe  nerve  a  characteriMic  opaque  white  color  when  viewed  bv  rellecleil 

At  we  shall  we,  all  nerve-fibre*  do  not  iioeoew  a  medulla,  an<l  hence  euch 
■  Hire  aa  we  are  describing  it  cadled  a  meaiti/aUd  fibre. 
X  iJP***^  luedullaied  fibre  conaitt*,  then,  of  the  fullowinK  parte: 
1.  tie  a/w-4'yit4'/rr,  a  central  cylindriciil  oofvof  eo-oallen  "prolopiaaraic" 
■U«ria),  (Mime  in  nature,  and  readily  utidctKoing  diange,  soroeliinm  swel- 
lia|««l.^>ni>'iim<««hrink!iit;.  and  hence  in  various  fpecinien^  appearing  now 
vilkick  baud,  iiuw  as  a  ihin  Mreak  in  the  axis  of  the  tubular  gheath.  and 
cMig  fal  enm  McUoq  aonetinwe  a  circular,  somctiines  an  oval,  and  not  un- 
nqimdjr  a  quite  irre^lar  outline.  Probably  in  a  perfectly  natural  con- 
mi  it  oecapiee  about  one-half  the  diameter  of  the  nerve,  but  even  ile 
auii]  mte  varies  in  different  nerve-flbreo.  Witen  teen  <|uiie  fresh  it  has 
■iaply  a  dim  cloudy,  or,  at  most,  a  faintly  Kranular  apjiearance :  under  the 
■Mtnoeof  resK^nta  it  ia  apt  to  become  fihrillated  lonffitudiually,  and  has 
^naiippoaed  to  be  in  reality  <^(>IU)MM7d  of  a  uuniber  of  delicate  longitudinal 
ftrilbe  united  by  an  interflbrillur  tulMtance.  but  thii  is  not  certain.  It  b 
knhn  Mid  to  be  prote«l«d  on  ii>  ciiii>ide  by  a  truuxpareui  sheath,  the  axis- 
rrliniler  theath.  but  tliis  alf)  in  divputnl. 

Tbt  axi»-cyliti>k'r  jimmisi  uubmken  thrmiiih  luiccewivc  nodes  of  Itanvier, 
lh»r>«ttrictKHiof  the  node  nut  afTectiuK  it  othcrwiM)  than  iierbajM  to  narrow 
il  Now  the  fibiesof  a  Npiiuil  nerve  I  omitting  for  the  pmeut  the  libres 
■■in  frutn  the  *yni|)«ith«-t)c  nerves)  may  be  trni-ed  bock  «ithvr  to  the  spinal 
pmHno  on  the  |iu>(f  rior  root,  or  along  the  anterior  riKit  t»  the  anterior 
WMa  of  the  •(linal  con) ;  nnd.nn  weaball  aeo,  the  uxi«-cyHndcr«  nf  the  fibm 
m,  ia  butli  <■«<«■»'.  prulongaiions  oi"  procrasee  of  nerv«-cclli',  in  the  former 
MHufoelUof  ih<-  ganglion,  in  the  latter  ciwe  of  cells  of  the  anterior  ooraua. 
b ikIi  ease  a  DnxHvi  of  a  cell  W-oming  the  axii-crlindcr  of  a  nerve-fibre 
nm  an  unbroKi-n  coiirM^  pasaos  as  n  continuous  band  of  [leculiar  living 
MUrr,  through  node  uflcr  node  right  down  to  tho  termination  of  the  fibre  tu 
Ur  iMcie  in  which  the  fibre  ends  ;  tlie  only  obvious  change  which  it  under- 
^  il  that,  in  many  if  not  nil  c:k<e«,  it  divides  near  its  lerniiRatioii  in  ibo 
taaw^  and  in  eoinc  canes  the  divisions  are  numerous,  and  jo\a  or  anaMtoraoaa 
ftMlf-    Obviously  the  axia-cylinder  ti  the  easential  |>art  of  the  nerve-fibi^ 


122 


THE   CO.VTRACTILK    TISSCK3. 


'2.  Th«  primitive  ^tvath  or  tKurilemma.  a  tubular  jtheaih  of  tnuupnreiiL 
appareatljr  bomogeooou*  niiitoml,  not  unliki-  that  iirnmrculeniniK  iu  iiitltirv. 
At  eavh  ni)dc  the  DvuriloiDinti  i«  ccitixtrictivl  »o  m  lo  ■■lubrtoc  th«  iixu-cylin- 
<)er  cIomIj-,  but  is  nt  the  vune  tirno  thickrnivl  by  »nmc  kind  of  ocnic&t  luate- 
riiil.  StiiinitiB  rca^iibi.  wpeciiilly  silver  nitrntc,  nppcnr  lo  enter  tbc  nerve 
libru  fnim  without  more  n-Atlily  al  a  nude  than  elsewhere,  itnining  lb«-  libre 
tiutH  n(  ihe  Dode,  and  creepio);  upward  nnd  downwnn)  from  the  ixxli;  iilimg 
tbc  axis-cjlind«r ;  hence  il  hns  beeu  ituppirised  that  the  uiitritive  flui<l.  ibe 
lymph,  oncora  into  the  fibn  i:  !  -  <  (^ts  access  to  the  8St§>eTlini[er  more 
rcttiiily  Rt  tlie  nodes  than  >!-  i-.h-  AImuI  midnay  lielween  every  two 

nodes  is  plac«<l  a  Ion)*  oval  mn  {■  n-.  <iti  the  imide  of  the  ueurilentran,  pushing 
the  medulla,  aa  il  wen;,  inminl.  ual  so  lyiiiK  in  a  shallow  bay  of  that  siih- 
Slsoce.  Immediately  surroundiu);  the  nucleui>  h  u  thin  layer  of  t;ranular 
subetanoe  of  the  kind  which  we  havo  ii[H}ken  uf  aa  undifTerentiated  proto- 
plasm :  in  young  newly  fornKil  librc  at  all  eveiiU  and  iKMnibly  in  all  fibres 
a  very  lliin  lny<ir  of  tliis  aamc  8ub«lance  lit  continued  all  over  the  aegment 
between  tbo  iio(Uv,  on  the  inner  snrfacc  of  tlic  nenrili'mma  between  it  aud 
the  medulla. 

3.  TV  nifjUtUa.  This  ia  a  hollow  cylinder  of  fatty  material  of  a  peculiar 
nature  filling  alt  the  space  between  the  neurilemma  on  the  outside  and  the 
axis-cylinder  within,  and  suddenly  ccasin^^  nl  each  node.  It  thus  fomn  a 
close  htting  hollow  Jacket  for  the  asis-eyliuder  between  every  two  nodes. 
The  fatty  malerial  is  lluid.  nt  least  at  the  temperature  of  Ihe  body,  but 
appears  (o  be  held  in  its  place  as  il  were  by  a  network  of  a  stibstano-  called 
neurokenMlin,  allied  to  the  siibtttanco  herutia,  which  is  the  basis  of  the  bomj 
scales  of  the  epidermis  and  of  other  horny  structures ;  this  network  i*  most 
marked  toward  the  outaiile  of  the  mediilln. 

8o  long  aa  ibe  nerre  in  in  a  frenh  living,  perfectly  normal  condition,  the 
medulla  appcnrs  smooth  and  continuous,  showing  no  mark*  l>eyund  the  double 
contour;  but  in  nerves  removed  from  the  body  forcxaminntton  (and  accord- 
ing to  SDuio  observere,  at  times  in  nerves  stifl  within  the  bmly)  clefts  make 
iheir  appeHrance  in  the  medulla  running  obli'jiioly  innan)  Irom  lJi«  neuri- 
lemma to  the  axis-cylinder,  and  freanently  splitting  up  the  medulla  in  lueh 
a  way  that  it  appears  to  lie  composeo  of  a  number  of  hollow  con«s  [Hirtially 
slid  one  over  the  other  along  the  axis-cylinder.  These  clefts  are  spoken  gf 
as  indealationM,  At  a  later  stage  of  alteration  the  medulla  may  divide  into 
a  number  of  small  irrei-iilar  ina^eti  separated  by  floid  ;  and  since  ea«'h  small 
pieee  thus  Hoparatt-d  haa  a  double  contmir.  like  a  drop  of  medulla  exnded 
from  the  euil  nf  a  Ittire,  the  whole  tihre  baa  au  irregular  "  curdy"  appearance. 

The  esaeutiai  pun  tbuii  i>f  n  medullateil  nerve  fibre  (of  a  spinal  nerve)  is 
the  axis-cylindiT,  which  is  really  n  ^irobugaliou  of  a  procea*  fh>m  a  nerve 
cell  in  a  apiual  eunglion  or  in  the  spinal  mnl,  running  au  uubrokeai  course 
through  ncidi:  nuer  node,  never  in  it»  cour*i%  a»  far  as  we  know,  joining 
aoother  axis-cylinder  nnd  very  rarely  dividing  until  it  upproaeties  its  end, 
where  it  may  divide  freely,  the  diviBions  in  sunn;  casej"  annstomoaiui;  freely. 
We  may  conclude,  and  al  I  we  know  sup|iurU  the  concltisioo,  that  the  changee, 
making  up  what  we  have  called  a  nervous  impulse,  take  place,  primarily  aud 
chiolly  nt  all  events,  in  this  essential  part  of  the  nerve  fibre,  tlH-axis-cvlinder. 
The  ucurilemma  and  medulla  together  form  a  wrapping  fbr  the  nourishment 
and  protection  of  the  axis-cylinder,  tJie  fatty  medulla  probably  serving 
partly  as  pn>]>ared  ftiod  for  the  ax 'is-cy Under,  partly  as  a  mechanical  sup- 
port; possibly  it  may  also  play  a  part  aa  an  insulator  iu  tlie  electric  phe- 
nomena. 

It  is  eamy  moreover  to  see  tbnt  while  the  axis-cylinder  along  its  whole 
Icugth  is  practically  t^whatever  \nt  the  exact  manner  of  its  funualion  in  the 


CUASG83  i:?  X   311'aCLE  DURING   CONTRACTION.       123 


vo>  m  i»n  of  the  eall  of  whii^  it  is  ma  vlongUwl  pfocnii  mch  nocment 
ttrn  txrre  two  nodes  rrprcwnls  a  cell  wrnpping  rouiid  the  iuct*crTiii(liir 
rtiw,  i>r  wfiicb  D)-ll  the  nucleii*  brtwcvu  thv  tradu  is  the  ODcIeiu,  llio  n«u- 
I  riWmiD*  ihr  mivcIom  or  cell  irslt,  and  (though  this  a  mrhupe  not  ijuitu  to 
\damr)  the  iiifdHlU  iW  c«ll  suMmiice  Iu^It  converted  into  tatty  tnaleria),  a 
n*ll  in  tut  wbiob  it  raiUf  uiitfide  the  axis-cyliiidcr  or  nerve  libiv  pro|>er. 
It  u  alaoy  the  ftxi»«yUod«r  that  the  uervoiis  impul^ei  sneep.  and  each  wrap- 
pinjt  rrll  only  serves  to  noumb  and  protect  the  seumeut  of  the  axuKtylinder 
bp|<B««v  iia  two  nodea.  And  we  acrordinftly  6»d  that  both  Mt  the  beginniug 
nf  the  aerre  6bK  in  the  ganKlion  '«n  or  ^pianl  cord,  and  at  its  end  in  the 
.  h<iUi  neurilemuia  and  medulla  dlsajijienr,  the  axi^cylinder  only  heiujt 


hA. 

A  nem  soing  to  a  muael«  is  chJvtly  (x)tii|iuiH!d  of  iiiedii Haled  Gbrw  aa  juiit 
HIhmI.  the  uinjority  at  which,  i-:idiug  in  cud-plnl«s  in  the  rauaculnr  tlbres, 
atv  the  fibres  which  cuoducl  thi*  nefvouN  iiii|MilwM  to  the  mtiitcle,  cniuin;;  it 
to  eoauact.  aiul  ma^  haDn  be»pokcii  of  a»  awtor  nerve  fibrcH.  Some  of  the 
Cbttv  however  cu<l  tn  other  partx,  such  n»  the  lendoD,  or  the  ci>iiiiectivc  Um- 
•os  between  the  bundlw.  and  mme  in  tbo  bloodvcstels.  There  are  rcnsoni* 
for  thinking  that  lonio  of  tbvef  ccinvey  impiil«s  from  the  muscle  to  tho  ccn> 
timl  aerrous  system  and  an  consequently  Rpokcn  of  as  sensory  or  afffrenl 
ftbns.  conoeming  tboee  connected  with  the  bloodvoMels  ne  sball  speak  io 
iMiu  with  the  rsseuiar  ayaUm. 

t  tm.  \errr-enitinyt  in  ttrialfd  mttmitar /ibrtt.  A  nerve  on  eoieiiDg  a 
BMcle  divides  into  n  number  of  hrancfaee  which,  runnins  in  the  conneeUve 
IMW  of  the  muscle,  form  a  plesua  rotmd  the  bundles  of  muscle  6bres,  tlie 
tsaller  branches  forming;  a  plexus  round  lite  muscle  fibrw  ihemselves. 
Fma  this  plesua  are  given  off  a  nund>er  of  nerve  fibres,  runnini;  ainj^ly, 
wkef  which  Joinings  niiude  fibre  eiiilf  in  an  cnd-pl&tv.  In  furniinj^  these 
[hniH  ihr  irxlividiiiil  nt-rvi'  libra*  divide  rejHTiili'dly,  the  diviiii»n  ulwny* 
tikfait  plofv  at  a  niHt<!  of  Kanvier,  so  lliul  wlial  in  it  xinglct  nerv*-'  tihn:  iii>  tuc 
SSTintrn  the  muK-lc  may  give  rise  to  sovomi  tu-rvo  lihnv  ending  in  wve- 
hImbmIc  fibm.  Tlie  tier\'c  fibre  joins  the  niiiscto  fibre  n*-  about  its  middle 
trniaewfaat  nearer  one  end,  and  occasionally  two  nerve  librM  may  join  one 
nH*  fibn-  and  form  two  efld-plales.  The  gonvml  distribution  of  the  bun- 
fc  <if  n«rve  fibtvs  and  single  nerve  fibres  is  eueh  that  some  portion  of  the 
■Mtin  is  left  fVee  frufl)  nerve  6bres;  thus  at  the  lower  and  at  the  upper  end 
■'lb  Mrtorins  of  the  frog  there  is  a  portion  of  muscle  quite  tree  from  tterve 


X  mi)[k  nerve  fibre,  ninniuf;  by  itself,  has,  outside  (be  neurilemma  an 
iHiiuiwil  delicate  «heath  of  Rn«  connective  tissue  known  as  UenW*  Aet^h. 
sUcfc  nnpeara  to  be  a  continuation  of  the  connective  tisuie  forming  the 
iksih  (if  ike  nerve  branch  from  which  the  fibre  spraii||C,  or  uniting  the  fibres 
tvohcr  in  the  branch. 

The  actual  ending  of  llie  nerve  fibre  in  the  muscle  fibre  dtflbrs  in  different 
dHBW  of  animals. 

la  nammals  and  some  Dth<>r  animals  the  nngle  nerve  fibre  Joins  the  nius* 
difbn  in  a  iwelUng  or  projectiufi  having  a  more  or  Icat  oval  btuic,  and 

rwtng  wliea  seea  iid«mys  as  a  low  conical  or  nmndeil  cminenoc.  At 
Minmit  of  this  eninaoce  the  nerve  fibre  Wot  both  iu  slivuth  of  Ueiile 
nk  il»  neurilemma,  ono  or  other  or  Imth  (for  on  this  point  observers  do  Dot 
•PfeJ  becoming  continuous  with  the  sarrolemma  of  the  muscle  fibre.  At 
tb  wnaiBit  of  the  eminence,  where  the  shcutlis  fuse,  ihe  fibre,  now  coiwiattng 
«ly  uf  nxi«-cytindcr  and  medulla,  loees  its  medulla  abruptly  <  in  Ihe  mus- 
chs  of  the  lon^'ue  the  nerve' fibre  in  many  caeca  Uxtee  its  medulla  at  sotne 
qaiiderahle  distance  before  it  joins  the  muscle  fibre  to  form  the  end-plnte). 


1S4 


TKE    CONTRACTILE    T1S3LE8. 


while  llic  axin-eyliTiiler  liranc-fac*  out  in  all  dir«rtiom,  lite  Monwivliiil  vni 
briiiiclitv,  whicli  wiini^liiiKW  niiiivtonxBU!,  forming  a  li>w  roniuHl  niiMi,  tr.  _ 
whiMi  viewbi  fruiu  abnvn  hiui  nn  BrhorcMci'-tit  »r  labyrinthinr  niiiM-nrann:. 
Ou  ilw  brnDchm  of  this  aborwccnco  mny  lie  unc  or  more  somcwhai  sriinulBr 
ftvnl"  iiiiclci.  The  nborcsccncc  ilsclC  hns.  like  the  nxw-cylindcr  of  which  it  b 
II  lUvciopmeut,  a  vita*  taiotlv  granulsr  or  cloudy  anpenninoc,  hut  lying  hv- 
twwti  it  niid  the  iictiial  muscle  aubstftticB  is  n  disc  or  bed  of  »om«Kh4il 
coaraely  granular  inBterial,  called  the  lole  of  the  end-plate,  on  which  lh« 
romilied  arbcire«ceiit  axi^cylinder  rests,  more  or  leas  overlapping  it  at  the 
edge,  but  with  which  it  appears  not  to  be  actually  continuous.  Lying  in 
the  iiiidat  of  this  "  sole  "  are  a  uuniber  of  dear  oval  transparent  nuclei. 

The  end-plate  theo  beaoaib  the  sarcolemma  consUta  of  two  parU,  the  rami- 
Bed  axis-cylinder,  and  the  granular  nucleated  a»le,  the  two  apgmreutly, 
thmigh  iu  juxlapMition.  imt  heiDg  ■.■»ntiniiini#.  Accunllngtu  t>onie obsen'en 
the  Vile  In  conliuuoii^  with  and  indeeil  is  a  sjiecinliztHl  part  nf  that  substance 
pervadins  the  whnl«  muitnilnr  fibre  which  we  spoke  of  nn  iutnrnbrillar  sub- 
ttatic&  W«  cnnnol  eiiliT  here  into  a  diMCUwion  of  the  jtrolinblc  mfniti»){  auil 
UM  of  tb(«('  iilnictiirce  or  how  ihry  cfTect  what  xccm*  obviouKly  their  Itinc* 
lion,  ihe  trani>  format  ion  of  the  chanpw  constituting  u  nervoun  impulw  into 
the  changes,  which  running  along  the  muscle  libro  in  the  latent  period  a* 
fur^runners  of  the  changes  cnlniliDg  actual  contraction,  may  bu  »nokvn  of  as 
cou>liluting  a  muscle  impulse.  It  is  of  inlereet  to  obwrvc  ttiat  orrtain 
analogies  may  bo  drawn  between  an  end-plnle  and  the  histological  elen»cnt> 
of  the  so-called  electrical  organs  of  certain  animals.  The  element  of  the 
electric  organ  of  the  torpedo,  for  instance,  may  be  regarded  as  a  muscle 
fibre  in  which  the  nerve  ending  haa  become  highly  developed,  while  the 
muscle  substance  has  been  arrested  in  ita  development  and  lia-t  not  become 
striated. 

In  amphibia  (f. ;/.,  in  fVogs)  the  ending  nf  a  ner\-e  fibre  in  a  inttacle  fibre 
b  Mntro'hnt  ililTcrcnl-  A  nerve  fihrp  about  to  end  in  a  muicle  flhr«  dirtdea 
into  a  hruch  of  several  nerve  tibrcs,  r«ch  of  which,  losing  it*  xheath  of 
Benle  aod  sarcolomma.  enters  th«  same  inusclo  fibre,  and  ihcn  Iiwing  il*  ni^ 
flnlU  runs  longitudinally  along  the  6brc  for  vome  distano^,  it  and  its  branebt* 
dividing  several  times  in  a  chnrncteHslicnlty  tbrkcil  manner,  and  Iwafiilg  U 
iniervats  oval  nuclei.  In  other  animnlfi  fi'rms  of  nt-rve  ending  an*  met  with 
more  or  lees  intermediate  between  thiit  seen  in  the  mammal  and  that  Mtcn  in 
the  frog. 

S  70.  llesides  the  medullated  nerve  fibres  described  in  S  6i!,  thont  are  In 
ini^l  nerves  going  to  muscles  a  few  and  in  some  nerves,  going  to  other  parts, 
a  large  number  of  nerve  fibres  which  do  not  possess  a  nieilulln,  and  hi.^nce  ore 
culled  •ton-meilit!tateii  ttl/rai :  these  are  ce^iecially  abundant  in  ihe  so  called 
syin)>iaihetic  nervuH. 

A  nou-medullated  fibre  which,  like  a  medullaled  llbre,  may  have  any 
diameter  from  '2  ^  or  Icki  to  20  "  or  more,  i»  practically  a  naked  axi^-crliiider. 
not  coverr<l  with  medullu,  but  liearing  on  it.i  outside  at  iuten'aU  oval  nuclei 
diapoied  loiiiritudinally.  Theso  nuclei  appmr  wholly  analuguus  lo  tlie  nuclei 
of  tlw  neiiriieninia  or  n  raedullattHi  fibrv,  and  proliably  belong  to  a  aheaih 
enclosing  eacli  fibre,  though  it  is  not  uiwy  to  denion«lmt«  the  independent 
existence  of  such  a  sheath  in  the  case  of  n»o«  ooii-mwlullated  fibres.  In 
the  similar  fibres  constituting  (he  olfactory'  nerve  a  sheath  in  i]uitt.'  oonspicti- 
ous.  Unlike  the  medullaicd  fibres  these  non-mo()ullatod  divide  and  alw  join 
freely:  like  them  eaob  may  be  regarded  as  a  proecw  of  a  nerve  ocll. 

Of  such  non-raedullated  fibivs  a  scanty  number  are  found  in  ncrvca  g<Miig 
to  muKlee  acatlered  anion^  the  medullate<l  fibres  and  bound  up  with  then 
bj  eonneotire  tissue.    They  appear  to  have  uo  connection  with  llw  muaculw 


ji»^ 


CtlAXnES    IN    A    IIUSCLB    Pl'RIN'Q    CONTRACTION. 


126 


fibns,  bat  to  be  dUiribuivil  clii«Hv  tn  tbe  bloudfesMl* :  mkI  lh«  ftincliou  of 
wa-SMlBlliutl  (ilinv  hid  beller  m  coDiidtied  in  coDn«*:ti<Ki  iritli  n«rve<i  nf 
vbidl  tbtjr  fonn  »  Inn;*  pun.  Mich  m  certuin  nerve*  goiog  to  bluwhwwU 
aod  lo  Mcntil^  QrgWM.  But  it  miiy  W  iiUt^il  thnt  though  thej  piwvtM  DO 
awdalia  ibtj  sr*  capable  of  pri>|>iigiaiag  uorvuiw  iinpulvu*  in  thv  sumo  way 
■»  Ottdalklcd  nurvw:  uiti  (bU  Tact  iniij  be  taken  u  inilknting  tliiit  llii* 
Bvdalla  caMDOt  serve  uiy  vcn-  important  function  m  an  vlectriv  insiiUt^ir. 

t  71.  TA<  rJiemiMry  of«  »enf.  We  havo  apoken  of  tfa«  lovilullii  ne  iHtiy, 
and  }Tt  it  in  in  reality  vcrr  largely  compoaed  of  asubatanoe  which  ia  nui  )in 
tbv  Mriet  mwe  of  the  won!)  a  lat.  When  wocxiimiDechernicollF  a  'juaniity 
otttmrrt  (or  wbat  la  practically  the  Bame  thing,  a  (tuauiilv  uf  thai  jwit  of  tbe 
nrntnU  nervmia  BystetD  uhicb  b  called  uiiilf  mailer,  and  which  as  we  shall 
an  i»  duaflv  cmnpoeed,  like  a  nerve,  of  niedullaled  nerves,  luid  is  to  be  pre- 
fcrrad  far  cotntcal  exaininatiuo  b«(.-uuK  it cootainB  a  relatively  l^InaII  (|uantity 
of  omMCtirv  tiauie),  we  find  that  a  very  large  proportion,  acoordiiiE  to  some 
•banvn  about  half,  of  tbe  dried  matter  «onsista  of  the  peculiar  bmly. 
flAal(«(«riM.  Now, cboteateriu  it  not  a  fat  but  an  alcohol;  like  glycerin, faow- 
•W,  which  i*  at*u  an  ulcobol,  it  fornw  ciom(Hiiiiiii>  with  fativ  nriil*;  lutd 
ihMgll  we  do  not  kn<>n  ilHinitrly  the  cbcniicnl  ivniilition  in  which  vhulvtittrin 
txbla  daring  life  in  Ihc  nH-diiUa.  it  i*  iiiorr  than  ]ir<>l>iil>k'  that  it  ex'au  in 
MM*  eonbitiation  with  aoiae  of  the  really  latty  bodic*  also  prownt  in  thv 
■(daibi,  and  not  in  a  Am  mlatcd  rtntc.  It  i*  >iDgtibir  ihat  liotiiti.'v  being 
in  Mcb  large  <|uanlitica  in  ncrvoua  tisHio,  and  to  a  small  extent  in 
Ikmca  and  in  blood,  cholcstorio  is  a  normal  constituent  of  biU-,  and 


tthagrcMer  partof  gall-Monea  when  th«wan  preocol;  in  galUtonea  it 
*  ttadoabudly  preaent  in  a  free  suio.  B«Nd«s  dioleet«rio  "  while  "  nervous 
aailer  cuntaim  a  leaa  but  still  coneiderabte  t^iiauiiiy  of  a  complex  fat.  wbtise 
Man  ia  dbpnicd.  According  to  ftumc  authoritiee  rather  lau  than  half  (hi* 
iMplii  &l  matint  of  the  peculiar  body  (eriihrn,  vrhioli  we  have  already 
«tt  la  ba  praMDt  abu  in  bloutl  curpusolo  and  in  muacle.  Lecithin  contains 
ititKliela  of  elaaric  acid  (or  of  oldc,  or  of  jMliiiide  octd)  aMoelatcd  tiot.  as 
iimfiaarr  6tU,  with  aimnlc  glycerin,  but  witlt  the  more  complex  glycerin- 
(btphuric  acid,  and  fiirttier  combined  with  a  nitrogenous  body.  »riirin,  an 
■aawaia  cumpound  of  some  eonsidi'mhlv  cumplexity;  il  is  tbercfora  of 
iHarkablr  nature,  sinoi!.  though  n  fnl,  it  conlniiis  bulh  nitrogen  and  phns- 
tiana.  Acoording  to  the  laina  aullioritits  the  rcmaindec  of  thr  complex 
■leMiiMa  of  another  fattv  body,  also  apparently  containing  nitrogKii  but 
hi lAosphonia,  called  etrtbrin.  Other  anthorilics  regard  both  these  bodice, 
Imtkia  and  cerebrin,  as  products  of  decomnosition  of  n  slill  more  complex 
bl.  failed  pfwtayoM.  Obvionaly  the  tal  of  the  whitr  mntler  of  the  central 
Mftoas  syMcffl  and  of  spinal  nerves  (of  which  fat  by  far  the  greater  part 
as«  asi*  in  the  a>edulla,  and  form  nearly  the  whole  of  tJie  medulla)  is  a 
my  tnmplex  body  indeed,  apecially  so  if  the  cholesterin  exists  in  coiubiiia- 
lica  «ttb  the  Ici-itliio,  or  cerebrin  (.or  prolacon).  Being  so  complex  il  ia 
sttatally  very  uiiMoble,  and  indeed,  in  its  instability  resembW  j^roteiil 
■BUar.  Hence,  prubahlr.  tbe  reason  nhy  the  medulla  obaogee  so  raindly 
ad  to  profocindly  aller  llie  drnth  of  the  nerve.  It  Mciua.  moreover,  that  a 
cmain  ihuugh  otinill  i|uautity  of  proit-id  matter  forme  part  of  the  medulla, 
•4  )l  M  puwihte  that  iht*  rxists  in  aoinc  kind  of  combinalioD  with  tbe  ouiu- 
fln  bt :  bnt  our  knunleilge  nn  this  point  is  inii«rfeLl. 

Tba  pcvcDOv  in  such  large  •(uamily  I'f  thi»  complex  futty  medulla  render* 
iksebsnieal  examinali^m  of  the  olhvr  con-ititueiitv  uf  a  iterve  very  difficult, 
lai  «ur  knowledge  of  the  chemical  nature  of,  and  of  the  chemiial  ehangra 
pianon  in  the  axis-cylinder,  is  very  limited.  Kxaiiiint-il  undvr  thi.-  micnj- 
w^  the  axia-eyllnder  gives  ibe  xaothopniUio  reaction  ami  otlier  iiMlicatious 


ise 


rHE   ro.VTBACTILK  TISafBS, 


thai  it  is  proteiit  in  nature ;  beyond  thu<  we  nre  lurgelr  confinetl  lo  inf 
W«  infer  that  ile  eheniical  niilLire  im  in  a  ^n^ral  way  ^milur  to  ibai  of 
oell  Klbetonoe  of  th«  uerre  <.-ell  of  irhicli  it  is  a  proceai.  \\\-  iufi^r  llial  th» 
chemical  nature  of  the  cell  imbalance  ut' a  nerve  all,  heingof  lh<f  kind  ithifili 
iit  fr«i]ueally  called  "  prutoptasmic."  is,  in  a  general  way,  mtnilnr  lu  that  of 
other  "proloplouuic"  eelU,  fi>r  tiialiiuue  of  a  leucocyb:.  Now  wbcrt^  wo  rao 
rxnmint:  convenientir  such  celli  we  find,  ati  we  hare  uid  ID  $  -lO,  thv  nrotvidt 
pmeiit  in  them  to  nc  M>ine  form  of  albumin,  m>me  form  of  elobulin,  aod 
either  niyonii  itiwif,  or  niiit- wdiTnix  of  myoBiii.  or  maic  allied  boav.  Id  otli«r 
words,  tbo  prolcid  hiwiii  of  tlie  kind  of  cell  aubitlaiicc  which  is  frmguently 
spokeD  of  as  "  imd>t)Vrvntiat«id  [>roloplii»m,"  does  not.  ia  its  broad  feature*, 
differ  inntcrinlly  from  the  pnitvid  tia«is  of  thut  "  diftcrcnliatcd  proioplasm  " 
whii'li  we  linvi-  cnllcd  tmimile  siihstaniT.  Hpdcc  we  infer  ibnt  in  their  broad 
chonii<^'aI  featiireii  the  axis  cylinder  of  a  nrrvo  librc  and  the  cell  iKxIy  of  a 
nerve  cell  resemble  the  substanre  of  n  mmcic  fibre;  and  this  view  b  sup- 
ported by  the  fact  that  both  )cr«»lin  and  lactic  acid  are  present  as  "e:x- 
traotivee,"  certainly  in  the  central  nervous  system,  attd  pronably  in  nerrea. 
The  reaeniblancc  is,  of  conrvo,  only  a  funeral  one;  there  must  be  ditloreiicca 
in  eberoieal  nature  between  the  asi^eylitider  which  propagates  a  iiervotu 
impulse  without  cliange  of  outward  liirm,  and  the  muscle  6bre  which  oon* 
liaela;  but  we  eanuot  at  prcDeiit  aiate  exactly  what  these  difference*  really 
are. 

After  tlie  fats  of  the  medulla  (and  the  much  amaller  quautltv  of  bt 
[iroent  in  the  axiit-eyliuder),  the  protelds  of  the  axit-eylinder,  and  ifie  oibei 
soluble  subatuDcea  preiienl  in  one  or  the  other,  or  gathered  round  the  nuclei 
oftfae  neurilemma,  have  by  variouH  inctuia  beendisolveduutof  a  ni^rvvlibre, 
certain  substances  still  remain.  Oueof  tb<fleinsaiaIlc|Liiuit)tyisthe  nuclein 
of  the  nuclei ;  another  in  larger  r|uaiility  '»  ihe  substance  nnmJ)emtiti  which 
forms,  as  wc  have  sovii,  a  supporting  framework  for  the  medulla,  and  whose 
moat  marke<l  charact«riitic  is,  perhnpt,  il4  mixtimee  to  iolution. 

In  the  ash  of  nerves  there  is  a  prepcinderaiico  of  potaasiuiu  salts  and  phot- 
phatei»,  but  not  so  marked  ne  in  the  case  of  muscle. 

Ji  72.  7'/te  nermu*  impwlte.  The  chemical  analogy  between  the  aubstauoa 
of  the  mtieole  and  that  of  the  axis-cylinder  wuulil  naturally  lead  up  to  (tip- 
poae  that  the  progrew  of  a  nervoua  impulse  along  a  nerre  fibre  was 
acooinjianieil  by  chemical  cbungei^  similar  to  those  taking  place  in  a  iniiad* 
fibre.  Whatever  changes,  however,  do  or  tuny  take  place  are  too  slight  to 
be  recuguiy«(l  by  the  means  ut  our  (li»p<)e>iil.  We  have  no  satfafactory 
evidence  thut  in  a  nen'e  oven  n.-pe'jited  nervous  impuKii  can  gi\-e  rise  lo  an 
lU'id  reaction,  or  that  the  dt-alh  of  a  nerve  libn;  leuda  to  such  a  reaction. 
The  ifniy  matter  of  the  central  nerv><>us  -^ystem.it  is  true,  is  said  to  be  slightly 
ucid  during  life  and  to  tieconie  ni»n-  acid  oAer  death  ;  but  in  this  gray  matter, 
nerro  cells  are  relatively  abundant;  the  white  matter,  compoeed  chiefly  of 
nerre  fibres,  is  and  remains,  during  action  as  well  as  rat,  and  even  after 
ikiatb.  neutral  or  ulighily  alkaline. 

Nor  have  we  iiali* factory  evidence  that  the  progras  of  a  nervous  Impuba 
is  accompanied  by  any  setting  free  of  energy  in  the  form  of  heat. 

In  fact,  l>eyond  the  terminal  results,  such  as  a  muscular  contraction  in  the 
case  of  a  nerve  going  to  a  muscle,  or  soma  affection  of  the  central  uervoiit 
system  in  the  cose  of  a  nerve  still  in  connection  with  its  nervous  centre, 
Uier«  is  one  event  and  one  event  only  which  we  are  able  lo  reoogiiixe  as  the 
objective  token  of  a  nervous  impulse,  and  that  is  an  electric  change.  For  a 
piece  of  nerve  removed  from  the  body  exhibits  nearly  the  same  electric 
pbsDOTOCoa  as  a  pieoe  of  muscle.  It  baa  an  equator  whidi  is  electrically 
pMgliv«  rslaliTcly  to  the  two  cut  ends-     lu  fact,  the  dJagnm  Fig.  84,  and 


ODASOKfl   IN    X    UVHVUK   Dl'BINO  CONTRACTION.       12" 


ilk*  dnoiptioD  which  waa  siveD  in  $  6<1  of  tbe  el«ctrio  change*  in  mtucle 
mmj  Ui  applied  bIrkmI  u  well  to  a  nerve,  except  that  the  currents  are  in  all 
cBMt  anirb  roun-  (evMv  In  the  caie  of  nerrea  thanofmiMcleB,  and  the  ipecial 
mrrvata  IVani  tlm  circatattreaix  to  the  centre  i>f  the  iransvene  sections 
cBaout  wll  In'  nhoKU  iii  a  sletider  nen'e;  indceil,  it  is  ilouhifiil  if  ihev  exist 
at  a!i. 

During  thv  iMfMgo  of  a  uervouit  impubu  the  "iiuiunil  iierro-vurreot" 
I  nrinUivo  varintitiii,  junl  a*  llw  "  iintumi  niuwle  iiurri-nl "  iiiidor- 


■  a  nigatiii  variali"ii  iluriii^  a  cuotrnction.     Thom  iirc,  moreover,  naMnii 
Um  cwa  of  the  DUtc,  an  in  iht  raMi  of  tin-  inunclr,  which  li^ul  uk  to  douht 


lb«  prafxIstenM  uf  any  «uch  "  imturnl "  currcntx.  A  ntrvo  in  nn  nlwoliicvly 
lutarml  niaditinti  ap|>mrF  to  be.  like  a  muflclc,  iwKlvclHc  ;  hoiicr  ne  may  say 
that  is  a  anxr  (hiring  llic  jinwaige  of  a  nervous  impulso,  as  in  a  muscle 
dsrina  a  muK-ular  contmclion,  a  "  ciirrcDt  of  action  "  ia  developed. 

^'tw  "  current  of  aclioo  "  or  "  itcgnlivc  vnnation  "  may  be  shoim  either 
bv  tht  icalvaiHMnetcr  or  br  the  rhewcopic  frog.  If  the  nerve  of  I  lie  "  muscle 
avm  pmMralioD,"  Jl  (tee  §  ti7>  be  placed  in  an  npproprinte  manner  (m  a 
llM*«aglify  irrilalileuerve,  J  (to  shicn.  of  course,  DO  luuscte  Deed  t>e  aiuiched), 
M»eUag  for  instance  the  equator  and  one  end  of  ilie  nerve,  tlien  siueU 
tadwtioo-aliocks  sent  into  the  ftr  end  i-f  A  will  cause  sioffle  Hpiutuia  in  llic 
tmsrlf  of  //,  whil<r  leiniiixation  of  A,  i.e.,  rapidly  ni|>oated  thocks  »ent  into 
A.  will  cause  ti-uiiiin  of  the  muscle  of  B. 

Hiat  lilt*  <iirr«iii,  nhdhrr  it  be  regarded  ait  au  iudc)i«Hdeiil  "  current  of 

Mliso  **  or  as  a  iiejjativi'  vBrmli<in  nf  a"  prMxisting"  current,  ts  nn  nwrntial 

latiirr  of  a  nrrvoiu  inipulM;  i!<  »lion'n  by  the  fact  that  the  degree  or  intensitv 

tf  Ih*  one  vnri<-»  milh  iliut  of  the  other.     They  l»olh  truvcl,  loii.  at  the  Htine 

an.    In  da>cribing  tlifl  muscle -curve,  ami  the  niclho<l  of  measuring  the 

■SK»br  lalmt  [wnod.  ire  have  incidcDlally  shown  (^  ■lli)  bow  at  the  aame 

tas  the  velocity  of  the  oervoue  impulse  may  be  measured,  and  staled   (hat 

lis  rale  ill  tbe  nerves  of  a  fru);  b  about  IJ^S  meters  per  second.    By  means  of  a 

•pnil  snd  Mrocnhat  complicated  apparatus  it  is  ascertained  that  tlte  current 

■f  (rtiiai  travels  aIoD)(  au  iwlatc^l  piece  of  nerve  at  the  same  rate.     It  also. 

likrtW  nwleciilar  choose  in  a  muscle  precedioK  the  coutntcuon,  and  indfed 

iW  conlradion  itself,  traveb  in  the  form  of  u  wave,  risiiifc  rupidlv  to  a 

am  at  each  [loiiit  uf  the  nerve  and  then  morc)j;rHdiiiilly  declininB 

Tlw  length  of  the  wave  may  by  speciul  mcjiiis  be  measured,  and  is 

laul  III  br  about  IM  mm. 

ITIvn  an  irtilaied  piece  of  itcn-e  i*  .^timuluied  iu  the  middle,  lb?  oiirrcnl 

ittiti'a  i*  |>n>|>af(aied  (Kfually  ncll  in  liulh  ilinictioiia,  and  that  whether  the 

r  Ilea  cliieflyaBDMnror  a  cliiefly  motor  nerve,  or  iiide<-d  if  il  he  a  ncrve- 

OQUpaised  excloiivwy  of  motor  or  ofuauury  (ibrcn.     Tnkiii);  the  curroiK 

«f  acftinn  as  the  lok(.'n  of  a  iirrvous  impulxc,  we  infer  from  this  that  when  n 

flbr«  ia  BtiniuUti'd  artiticially  at  any  juirt  of  il«  course,  the  nervous 

going  Irnvvls  in  both  direction)^ 

naeil  jost  DO«r  the  phrase  "  tclanizntion  of  a  nerve,"  meaning  the 

^pUaAioD  to  a  n^Tve  of  rapidly  repeated  shocks  nieli  as  ironid  pr<iduc« 

tAtmt  in  tbe  muscle  to  which  the  nerve  was  attachiil,  and  we  shall  have 

hysiit  nccasioD  to  employ  the  phrase.     It  must,  bowcver,  be  anderstood 

Am  tWv  ia  in  tbe  nerve,  in  an  ordina^  way,  no  summation  of  nervoua 

eiim|)antble  to  the  Himmation  of  muscular  contractions.     Putting 

(vrtain  enseo  which  we  cannot  discuss  here,  we  may  say  that  the  series 

rfifcuks  *mit  in  at  the  far  eiwi  of  the  nerve  start  a  scrieH  of  impulses ;  these 

ttntl  down  the  nerve  and  reach  (he  muscle  as  a  series  of  distinct  impuWa  ; 

«4  iW  tint  change*  iu  (he  niiifcle.  (he  molecular  la(en(-period  chan^,  also 

Itm  A  acrirs  ibe  memlwre  of  which  are  distinct.     It  is  not  unul  these 


sdktvrt 


128 


THE   L*ONTBACTIt,E  TISSt'BB. 


molecular  (.■liaii;:ea  bec»rae  irBnaforroed  into  visible  changes  of  fiina  that  tmy 
flisioD  or  eiimiuultoi)  tnkee  place. 

$73.  ruttiiiK  [i)|:«ilier  Lbe  facts  oontaiii^l  in  lIiU  anrl  tlie  jin'CHltDg  *ee- 
Umu,  the  fiillim  ii];;  luuy  be  taken  as  u  brief  n|]|>foximnl<:  liWlonF-  at  what 
l»kc«  place  in  a  niuMte  and  oervc  when  itie  Inner  t*  lubjected  U>  n  fiiivle 
iiMliiction-aliuc'k.  At  the  intitaiii  tbtu  tbe  induwd  current  immki'  inu>  tne 
□ervG.  cliKiigvn  uociir.  of  wbo«e  natiin;  wc  know  nolliiiig  corlam,  oxa-ii*  that 
they  cnu»c  n  "  current  of  action  "  or  '■  negative  variation  "  <jf  the  "  natural  " 
nerve  current.  Thwc  clmngw  profiHgiitc  llKrinwlvra  along  iIh'  ncrxT  in  hoth 
(Iirv<ctions  as  n  ncrvnti»  impulou  in  the  form  of  a  wave,  haviug  a  wavv-len^b 
of  about  18  mm.,  and  a  velocity  (in  frog'«  nerve)  of  about  'la  m.  per  MocmcL 
I'lUNng  down  the  ucrve  fibres  to  the  niM«clc,  flowing  along  lbe  branching 
and  narrowing  tracts,  iho  wave  at  last  breaks  on  the  end-ptatcs  of  the  fibree 
of  tbe  muscle.  Here  it  is  lriiusntut«d  into  what  we  may  call  a  nmsde 
impnlae,  with  a  shorter,  Elcejwr  wnve,  and  a  greatly  dimintfhed  velocity 
(aooui  3  ni.  pier  secoDd).  Thii)  muscle  impulse,  of  which  we  know  hardiT 
tuone  than  that  it  is  nmrked  by  a  current  of  action,  travela  fraiu  each  ena- 
plate.  in  both  itireciions,  to  the  eiul  of  the  tibre.  where  it  appears  to  be  Iom  ; 
at  all  eveuta,  we  do  not  know  wliat  becomee  of  it.  As  this  impulse  wave, 
whose  develupmeni  lak<«  plac«  eulirely  within  the  latent  period,  leaves  the 
end-plate,  it  i->  fnlKiwed  by  an  explosive  deciim position  «f  material,  )c«dtug 
to  a  iliHchar;^'  "f  carbonic  acid,  to  tbe  apgwaranoe  of  soom  subcitaur«  or 
iiul)«tJUic<3t  with  an  acid  reaction,  and  probably  of  other  unknown  thi 
with  a  ciin.-iideriihle  development  of  heal.  This  ex]>loitive  deoompoaitioii  g[' 
rise  to  the  vLtiblc  contraction  wave,  which  travebi  behind  the  inviiiible  m' 
de  impube  at  about  the  tame  rate,  but  with  a  vastly  increatcd  wave-length. 
Tti«  fibre  a»  the  wai.'e  paaMs  over  it,  awells  and  diorteoa,  and  ibiu  brings  its 
two  nwit  nMtn>r  together. 

When  repented  shock;  are  given,  wave  followo  wave  of  nervous  impulse, 
ninscle  impulse,  and  visible  coniraclii>n  :  but  the  last  do  not  knep  dislinct ; 
they  are  fused  into  the  coutinued  shortening  which  we  call  tetanus, 


The  Nature  of  the  Chashbs  Throitoh  which  as  ELixTRir  CV brext 
IB  Able  to  Uexrbats  a  Nervoi»  iHruL^K. 


.licfion  of  the  CoixMatU  OunviU. 

i  74.  In  the  preceding  account,  the  slimuhi»  applied  in  order  to  give  ii»e 
to  a  nervous  inipiiUt!  hib>  always  been  siippi^'<l  to  he  an  induction-* hock, 
single  or  rcpeate<l.  Thi*  choice  of  slimuliu  hns  been  made  on  accoiinl  of 
the  nimoft  momentary  duration  of  the  induced  cnrront.  Had  wc  used  a 
current  lasting  tor  some  considerable  time,  the  problems  before  u«  would 
have  become  more  complex,  in  consequenoc  of  our  having  to  distinguish 
between  the  eveiiis  taking  place  while  the  current  was  passing  through  the 
nerve  from  those  which  occurred  at  the  monient  when  the  current  WM 
thrown  into  the  nerve  or  nt  the  motnent  when  it  wns  shut  ofl'  from  the  nerve. 
Ttiwe  complications  do  arise  when,  instead  of  employing  the  induced  current 
aa  a  stimulus,  we  use  n  eoiitlaul  enrveni,  I.e.,  wheu  we  paas  thn>ugh  the  nerve 
(or  muscle)  a  current  direct  from  the  Italtery  without  the  intervention  of 
any  iuduelion-cQil. 

Ilefore  making  tlie  actual  experiment,  we  might,  perhaps,  naturally  >un- 
]>o)e  thiit  the  cou.-itant  current  wotild  act  an  a  Mimulus  ihroughoul  the  wltole 
lime  during  which  it  wan  applied  ;  that,  ho  lonv  a*  the  current  passed  along 
Iho  iwrve,  nervous  imnulitvti  u»uli)  be  gcni-nili.-*r;  and  tJnU  thwe  would  throw 
lh«  musde  into  sometliing,  at  all  event-'*,  like  telunu*.     And,  under  certain 


S'TIJHTl.rS  BT   BLECTRTC  Cl'RRBNT. 


129 


I.  thu  >lix«  Ink*-  |iltw«;  ocoukiuiillv  il  does  liii|i]>ai)  Oiiii  at  tlie 

b«  ctimiil  ia  itimwti  into  (Im  nerve  IIm:  iiiiux'li;  uf  the  iiiui>cli'- nerve 

p*«|)*nui«i  fall*  iiiii)  n  teuinii*.  which  u  c<jui»ii>mJ  nmil  the  ctirn-iii  is  ihut 

vt;  but  •uch  >  nwilt  U  cxivpliiiimt.     In  l)i«  vnsl  luitjoritir  of  cn*es  wh&t 

'"rr^"'  ^  **  fvllovrs:   At  the  mooieut  ilmi  ih<-  drciiii  h  raadv.  tko  mo- 

n«U  tbU  tlio  current  if  thnmn  into  iIh'  urrvn,  n  tiaelij  twiu'b.  n  >^m[i)e 

ooMnctina.  tbi-  k^-cxIImI  auikiny  fonlmeiion,  io  witniwciT;  but  uflcr  tbU  ling 

fw  I  sasr  the  muM-l«  remaiiiA  nltmlulrly  iiiiiwcoDt,  in  ipile  of  iW  current 

diotinuinc  topsM  ibr^iugh  the  ncne,  ami  lhi«  fjuiSManctH  miiinlnined  until 

Um  circuit  t^  broken,  until  ibc  current  ie  shut  utT  fnna  the  nert'e,  wii«D 

■Dolhrr  Hnipl«  cituintctioD,  tlie  so-called  tirmHny  mntmrlion,  n  observed. 

TIm  nrrv  pHwaffe  of  a  conatajit  curnnl  of  unironn  inlciuity  ihn^n^h  a  nerve 

4o»  DM,  uodvr  urdinarr  eircumslancee.  net  as  n  Btinmlus  (•eneraliuji;  ii  M«rv- 

utM  ini|Mib*:  Mick  ttoimpukeitfODly  set  up  when  the  current  either  falls  iaio 

ur  b  •but  olT  frxiin  the  nerve,     ft  is  tli«  entrance  or  liie  exit  of  the  current, 

aad  Ddt  the  continuKDce  of  tli«  current,  which  is  the  Htimuliia.    The  •|uii»- 

MOW  uf  ib«  nerve  uid  mu»cle  during  tlie  pawaj^  of  the  curreut  i»,  howercr, 

ifarwiiitm  on  the  current. rtminininv  unifunu  in  intenAily,  or,  at  letui.  not 

Inn^  MtddrolT  increu«d  or  diminiiibMl.     Any  mflicieiitJy  middeu  and  Inree 

iMMM  or  diniiautioD  of  itir  inU-iiMij  uf  'i)ie  curreut  will  act  like  t£a 

OMfsof*  or  nit  of  a  ctirront.  and  by  j^ncratinK  n  nervous  impuljte  give  rise 

H  a  cKMiinu-tion.     If  tW  inlc4uil^  at  the  cnrrwit,  however,  be  very  tduwly 

■ad  ^Tvdnnlly  incmi»ed  or  dimioiiihi-d,  a  very  wide  rutgv  of  iuienoily  may 

W  (awvil  ihniiigh  willMdl  any  c»ntrac(ion  lidog  mcji.     It  »  the  xudden 

tlufD  froa  MM)  oooditioD  to  aiiirther.  aoil  not  Uie  condition  it(«lf.  which 

laaai  Uw  nervous  impnlM. 

Id  manr  ooMi,  bolli  a  "  making"  ami  n  "breaking"  contradion,  each  a 
uplc  twiteh,  ar«  oWrvol,  au'I  Um  ift,  perbugu,  the  commoDeet  event ;  bnt 
*W  ibe  current  ia  very  we«k,  and  again  when  the  current  U  very  strong, 
dibr  tbe  brmkinz  »r  the  miikiuj^  iHniiraction  may  be  absent;  t.  e,,  there 
Mf  b«  a  ouniraciion  unly  when  lh«  i-tirreut  is  thrown  into  the  nerve,  or 
•■rr  afaan  il  i>  «Uut  »S  fnmi  the  nerve. 

tnikr  onlinarv  cirounLiiauccii  the  omtriictixiis  wituemetl  wtlh  tha  eOD- 
Nai  current  rilfier  at  the  make  or  nl  the  break,  are  of  tbe  natnro  of  a 
'4mfit "  oontractioo  :  but.  m  lia«  alreiuly  be«-n  naid,  the  ap|dic«lioti  of  the 
mmi  BM/  giro  rUc  to  a  very  pronouucnJ  letanud.  Huch  a  t«UinuB  ia  seen 
■WliBHa  when  tiM  current  >»  tnw<h;  Infttii^'  during  the  application  of  llie 
wm,  aometiaMi  when  tlw  nirrvnt  i*  broken,  laMing  »onic  time  after  tbe 
(Rent  baa  been  wholly  removnl  fmni  tbe  nerves  The  former  i»  apokeoi  of 
■  t "  Making."  th«  lattt^ra*  a  "bronking"  lelaniu.  liitt  ihote  exceptional 
naki  of  the  application  of  thf  onnniant  current  nwtl  »ol  <tetaiii  u«  now. 

n*  graal  inicreal  «tta>-hctl  to  the  action  i>t'  the  consl^uit  current  lies  in 
At  6m  that,  during  the  pgifnijn*  of  the  vurreiil.  in  «pile  of  the  abwn<-e  of 
ll  avTOOB  inipulc«>.  ami  llicr^Tore  of  all  muscular  c<inlraclionB.  ihe  nerve 
kfcrlba  line  both  bclni.m  and  on  each  "idc  of  liie  electrodes  priifitundly 
mtiti  la  a  owat  peculiar  manner.  This  mtHliticalioii,  important  bi>lb  for 
A*  %fc»  h  throws  on  the  genenilion  of  n«n,-i>u»  impuisM  and  for  its  pravli- 
•I aBpSortlona,  ia  kmiwu  under  the  name  of  <Jr<tivt<inu*. 

\ilC  fitarfrotontw.— The  markeil  rcalur«  of  tbe  riectrotonic  condition  b 
llai  tlta  oerve,  though  apparently  'luiewent,  is  chanct-d  in  reaped  to  itA 
BrittUity:  and  tlui  iu  a  dittereut  way  in  the  nrighborfaood  of  the  two 
ihdnaW  raspeetively. 

S»ffimm  that  on  tlie  iwrve  of  a  muscle-uerve  prepanilion  are  plai^  two 
1—  [ailatiiatiliij  ctecln>dea  (Fig.  40,  u,  t),  connected  with  a  battery  and 
>)  with  a  key,  to  that  a  constant  current  can  at  pleasure  be  Uirown 


-JlIE  I'DNTBAC'Tll-E  TI8SCBB. 


into  or  shut  off  from  the  nerve.  TliiH  M>ii«(aui  c-urivnt.  w)iii»e  efleci>  u-( 
■bout  to  stiiily.  may  be  c»lle«l  the  "  |i»lariiin};  ctirix^iit."  L<?t  n  \n:  the  puct 
live  ekctroilo  or  anode,  aad  k  lite  nejraiive  doclriKie  or  knlbiMk-,  both  jiliiccd 
St  H>nie  dislaDCo  from  the  ii)usi-le.  iitid  nlito  yrhh  n  cerliiiii  inU'-r«-Bl  Ih-Mvcmi 
cftch  other.  At  lh«  jMJiit  x  lec  lher>e  be  npplk-d  n  piiir  of  vWlr\>d<» 
Dectod  witti  iiD  iiKluL'Uui)  eoil.  I^et  the  tiiiiw^lt'  I'lirihnr  hv  coniicrtnl  wi  _ 
lever,  M  that  ila  i>iiiiimc(ionii  tun  In;  ret-orckil  iim)  tboir  mnouiit  mra»iin-d. 
Before  the  |i»lnriziii|c  current  in  ihroMii  inln  the  i)or\-t^,  let  k  niil'Ic  in<bicti<>D- 
(iinck  of  kiionn  iiitrimitr  (n  «mk  nan  bi-ing  chomi,  or,  at  k-Jifl,  not  one 
nbioh  vroulil  ciuim*  id  the  iiiii»t'If  ii  Duixtniiini  <><>ii tract toit)  he  tltruwn  in  ■! 
r.    A  votitriK-tioD  nf  «  oerntiD  nnwiint  will  fnllon-.    That  coiitmctiQU  niar 

rio.  ul 


\ 


B 


Itnajtrtmxi.  pjttt^axTiaia, -"ixli  ibn  arrrv  ntxmA  In  A  ivailMRwIteffiiiuIla  Sioui 
■uaoiIiAfcnuiinuiriirTuaL 

Inmrh  n  Li  Ihv  BiiiVli.-.  ('  inv  lnKlimlv  of  iliv  miutaiil  fiiirfiit:  i  repnWDtt  llM  (t«l  dlien  lk| 
liuliii'lliiii.*hijc^,  uteJ  10  ini  ihL-  IntlHliilII}  oT  l)i«  intrmaru  anit  Id. 

\k  tnkcu  as  n  luenaure  of  tb?  irritJibility  of  th«  iwrvc  at  th«  pcunt  f.  Nov 
let  itie  |H)IuriEiug  ctirr«nt  be  (hrown  in  iiikI  lot  the  kathude  or  iieRmtive  [Hilr 
1>C  m-urt-Bt  the  luuw^le,  as  in  Fig.  -10,  A.  »>  thiit  the  curr«at  pawcB  alntig  tbr 
ncrVL*  ii)  a  direction  from  the  central  nervows  syRteui  lowarxl  the  tnUKk; 
BlK'b  a  current  is  B{K>keu  of  a;*  a  ilr-rerti'liny  one.  The  entrance  of  l)i«  polai^ 
iiing  current  into  the  nerve  will  produce  a  "  makinj;  "  cootravtion  ;  this  m 
niD)'  neglect.  If  while  the  current  is  possiDj;  the  «ain«  uidueliiin-*bock  nc 
b«rarc  be  sent  tliroueh  X,  the  contraction  which  rceulls  will  ht-  found  to  Ix- 
greater  tliau  on  tbe  former  occuiton.  If  the  |i<>liiri/inK  ciirroni  hv  aaw  Mhnt 
offj  B  "  hri-akiug  "  coutracliou  « ill  |>njliably  he  )>ri>diU'ed  ;  thiH  wc  lUwi  may 
neglect.  If,  now,  the  jniiut  jt.  idler  a  short  interval,  he  U|[iiin  tested  with  the 
same  imluctinn-Hhuck  ait  before,  tlie  coutraotion  will  be  no  lonmr  greater, 
but  of  the  same  amonnt,  nr  ]ierhn|iit  not  >a  great  lu  at  tint.  .During  tbe 
pnriwg.ci  of  the  polarising  mrrent.  therefore,  the  irritability  of  tbe  nerve  at 
tbe  point  r  hi>»  hcfn  tvniporurily  iHertnt^il,  v\di*  thi'  >amc  «hork  applied  to 
il  caiiM*  a  grv-ater  cnntnu-tioii  during  the  prewJiiw;  than  :n  the  abMinoe  of  the 
current.  But  thi»  i»  only  trnr  iu>  long  il-  the  ])iiluri»ng  current  in  a  descend- 
tag  one— so  long  lu  thv  jKiint  x  lir»  on  thi-  hicIi-  nf  tho  kathode.  On  tbe  other 
hiuid,  if  the  pijlarij:iiig  runrnt  had  l>r<-n  nn  nKi-ntitiiiy  one.  with  the  anode  or 
poaitive  pole  ncnrcj^l  Ihc  miisclc.  a»  in  Fig.  ^0,  B.  the  irritiibilitv  of  tbe  nerve 
at  T  wmild  have  been  found  \o\Kiii)iiii\i»hrd,xnt\nu\  of  iiicrcasea, byibe  ]>(]lar- 
izjug  cun^iit ;  tlie  cunlraclion  ohtaimxl  during  the  paseage  of  the  cuu»tMUl 


»TI»CLt:B   Br    ELKCTRIC  CIRHKST. 


ISl 


eamml  «(niM  bv  Ine  tlwn  bi-fuiv  the  pntsage  of  the  cumnl.  or  niieht  be 

•IhM  altDgaUwr,  ani)  the  viminiclion  iiftvr  ihc  rurronc   Imic)  been  «Aut  oiT 

■■■Id  ba  w  grtmt,  or  jtt'rlia|»  gix^nlcr.  tlinn  bcfoix--     Tlinl  is  to  tuy,  irheii  a 

nMMtsai  riirrent  is  iim'licH  lonlicn-p.  ibo  irrilubilitr  of  llie  iwtvo  lietween 

thm  piiUriiiit);  vlcclrijilM  mnA  ibt?  musrle  is.  during  the  passage  of  tbc  curr«Dt, 

I  kIh-ii  the  kalliocle  i*  nearest  ibr  niiiscle  (and  the  polarmii);  ouirenl 

llDU.i  flud  illiiiiiiishcil  uli«D  tlie  auode  is  iienrcMt  the  muscle  (and  the 

{■lubitii;  tnineiit  nsccitilinK '-     Ttie  same  result,  mutiilu  mulaiiditt.  aud  witlt 

HMB  i|aBlifi('aLio(ifi  wliich  we  iKeil  uot  disouas,  would  be  gained  if  J'  were 

fbccd,  nut  between  ihe  inuitole  and  the  [lolariziiiK  (.■urreiit,  but  i>u  the  far 

»im  »f  tbe  latter.     Hence,  it  way  be  ataied  ^■^"^"^"T  ''■i*'  during  the 

|aMBg«  uf  a  cunnlani  current  (brouj^h  a  tier^'e  tlie  irrilnbility  of  tbc  nerve  ia 

vtenamd  m  lite  regtnu  nf  the  kaibotte.  and  <linruiijlied  In  tlie  region  of  the 

uufAm.    Tbe  dtnngn  in  the  nerve  which  give  riie  to  this  increujfe  of  irrita- 

hililT  in  tb«  rci(ioii  of  tJie  kathodes  are  «|>(>ken  of  a«  hilelwlrult>tiu4,  and  ihe 

MfTc  b  Mid  to  bo  In  a  kalelecimlonic  i-nndiiion.    HJiuilnrly  tho  change*  in 

tl«  rnfion  of  tb«  anod?  arc  vjioken  uf  an  <i>ii-/irfroto»tut,  and  the  nerve  i*  nid 

to  be  in  an  aiflwiniloDic  t-ondition.     It  ix  alM  oAen  unial  to  «[tcak  of  tb« 

UivtectmiMiir  incrawc,  and  luii-lertrotonic  ilocrtMC  of  JrHmbility. 

Tkia  Uw  mMiw  tnie  nhnlcvtir  Iw  the  ni<ide  adopted  for  di.-icrmininK  the 
ifriubPitir.  The  rt^till  hol'U  k"-"!  not  only  with  a  xinglu  induction -vlitick, 
bil  tbo  with  n  tctaniiiiig  inli'rni[ii(.'4l  current,  with  chrmicjil  and  mochani* 
olriiMli.  li  further  Hpiware  to  bold  good  not  only  in  a  diisrclcd  nerve- 
MkIs  preparalioii  l>ut  also  in  the  intact  n«rve«  of  the  livini:  bo<)y.  Tbe 
and  (k-creiisp  of  irritabililr  arc   most   niarkc<l  in   ihv  inimwliale 


MUbdrbuod  of  the  otc<;trodes,  but  spread  for  a  considerable  dii>tuncw  in 
•aradiTfcUoa  in  the  eiimpoinr  ref,'ions.  The  same  moililicalion  is  not  con- 
laalbi  tbeexlra|M>hir  rcfinon,  but  exiata  al»u  in  ihe  in tnipolar  region.  In 
tW  intrajNilar  region  (here  luuAt  be,  of  uourae,  a  neulrnl  or  indilfvrvnt  jwint . 
tbot  the  katdectronic  incn-ave  niergcn  into  the  an  elect  rot  »nic  decreaae, 
uJ  wbtffi.  therefore,  tbe  irriiabiliiy  i^i  unchangetl.  When  the  )i»lariiing 
nnwiiiaifeak  one,  thin  iudilfcr^nt  jxiint  u  nt^nrer  the  anode  than  the 
krib«dt,bat  U  iIk  nolari«iii)i!  ciim-nt  increuM*  in  inlonsity,  dram  nearer 
u4  Huvr  tbe  kathode  im  Fig.  41  J. 

fm.  II. 


»■*■!«  tLUnrmim  TH>  ViHUtnoB  ur  iHBttian/TT  ui-uiNi  Ri^tcnDMNOh  wnn 
rouauisa  rtunvim  nr  IvrttiaHO  tnnsiTT,    irroin  fRogar) 
n*IKat>  I*  viiqnnd  Id  U*  iJaoXl  at  .1.  ilie  k41b«d*  al  8 :  AB  li  luiuHiaDndT  (hn  InimiJOlit 
Matt.   toM«kiirUnibr«*«>u-io«,Uioiianlana(ili«tiimb«to«'llwliM«Bn<t rvjifSHnwdlMln- 
■If,  llut>  tlbim.  tnvraucil  lirlutitlnr.    n  Wftiwim  lh»  (Okn  ot  •  inak  cumnl :  lliB 
I  tuaal  r,  U  nmi  IW  nnule  A.     In  |>i.  ■  nroDCH  I'umBl.  Ihe  liidlfltinil  pc4ii(  t.  It  iwanr 
I  Ik  iM  dnnlnunan  ••!  LrrlWUIIiy  la  uwitoiniioiKit  ■sJ  ili*  luprMw  i<>  knialccuuionut 
rUsn  Imp,:  IbeeflMI  ■!»  ipnail*  Air  a  (ivtar  dliUum  Along  Ibr  «i(ra]vUir  nt(ini» 
iHt  AMH^    In  rttb«<aB>n>iiuai«MeuK>beMUImoi«  mulwl- 

TW  ■OMKUil  of  IncrcMM  and  decrease  iadepewient:  (1)  On  tb6 >ti«Dglb 
tf  tk»  «nnu.  iba  Nronger  current  up  to  a  cerlain  limit  producing  the 


1S2 


THE   COXTHACTM.E  TlSflirgS. 


Knier  eHbot,     (2)  On  ihe  irrilHbility  of  ibe  nen-e.  lUe   more  irritAhle, 
ttr  condiiioDed  nen'e  beiog  the  more  aHectetl  by  a  current  of  the  «une 
tatvnaity. 

In  the  cx|>erim«nu  jii»t  de«crtbed  the  increase  or  decreuM  of  irritiibilitf 
t8  ukcn  u>  mean  tbat  the  tame  stiniuluH  maru  in  ifae  oDe  ease  a  lar^r  or 
more  powerful,  ami  iu  the  olber  case  a  smaller  or  le»  ener^Uc  impulse; 
bill  we  hav«  remioii  to  tliink  that  iJie  mere  tirojiagation  or  conuuction  uf  im- 
pulsra  slarlcd  el«ewbcre  la  aldo  alTected  by  Ine  elevtrutouic  CODdition.  At  nil 
evenU  Knclf^'lrotonujt  appeam  to  uffvr  an  ob*Uu-lc  to  the  punge  of  m  nvrvoiui 
imputee. 

§  76.  Eteeirotoiiie  currenti.  During  tlie  paatage  of  a  conswnt  current  tbmuxb 
a  nerrc,  varlallon*  In  the  electric  currents  belonging  to  the  nerve  iiMlf  mav  be 
obMTTed;  and  Uieno  VBTiationH  have  ceriAin  relation*  U>  tlip  varinlions  of  tlie 
■rrilability  of  the  nerre.    Thus  if  a  convtant  current  supplied  by  Ibe  battetj 

Fw.  e. 


h 


< 


Oijiotun  iu.i«i>Aniin  SUcmnognc  CcannrTK 
/•ihv  tnlorlilDS  bAiierr.-wItblB  liii<r.  p  ib«  anoAp.auJ  p' lh«  kaihodr.  At  ih«  Uft  •Bdt«f  < 
|dttp«of  nciTc  lUt  uniiml  curronc  Oouv  (lirounn  Ihe  jpiInrHimeler  Q  ttvtn  g  ioff\  ia  tiiVdlracO 
oT  iLu  nrruHt;  )i>aiirer(lou.  ihenthiir.  !■  (tio  tmiisai  Uinrof  the  inlvUlDR  cormit:  waM^ocntlr  ft 
■IiiaanlamunJ,  ulddlailHltiTlhiMlBii  t .  Th>  ounviil  at  llio  othor  «.tiil  <rf  tbe  |ilN*  of  ii«r*«^ 
IhHd  A  lo  A'.  ihroUBb  Uie  vilranoiagier  M,  floni  In  ■  coatnr)'  dIrceUmi  to  itw  poUrfdac  cnnvnt ;  R 
oonMi|U*QU)  appBB  Lu  br  illinliilttiiiil,  u  liKllCBtal  by  tboiltcii  — . 

X.B.-Pradmiiltdtjr'iMkr.  ttic  |»lBrlidnr  tumiit  IdiarttUITaWl  to  be  Ilirawii  limttha  nldill* 
at ■  FfNnor ncrrc, and tIWKiil»nuiaL>ivr  r'*™*)  >'  t'lu  iwovmlf.  of  coiin(lti*1llb»iiiiil«iMoo4 
Uiat  ths  Akiiuit  nuy  I«  Ibfowii  in  anjiwhvia.  atiil  tbv  litter  onnnn-lci)  wllb  1U15  two  pAlnof  (dnli 
wbMh  nlll  glT^ramata. 

P  (Fig.  4a)  be  applied  to  a  piece  of  nerve  by  means  of  two  non-polnriuibie 
eleclrodc*  p,  //,  tlie  "current*  of  re«t"  olitainable  frura  the  rannuH  pnims 
of  the  nm-e  will  be  diflerent  duriuK  the  paMaee  of  tbr  pulariiJuit  current 
friMn  tbone  which  were  uianifist  before  ur  nK«r  tlie  current  waa  applied ;  and, 
moreover,  the  obau£«a  lu  the  uerve-curreote  produced  by  tbc  pofarisiug  cur- 


DTIMDLrs    BY    KLKfTRIC   d'HRKNT. 


183 


I 


will  ihM  b*  lb«  MUM  in  the  nfijthborhDud  of  tbc  ■node  (;i)  m  tbonc  in 
IW  Mi^borboiid  of  Uw  kath»<)«  (p'y  Tbtw  let  O  aud  H  b«  two  gii]viui«< 
M»t<r»  ao  coBn«cUr<l  niili  tlio  iwo  piitta  of  th«  nerv«  aa  to  alTord  i;ood  aiid  dmr 
•v14«BCa  of  tlir  ''ciirrrnl*  of  r««l."  Itvfnrci  th*>  pnlariKJi)^  current  is  llirovn 
iMo  tk4  B«m.  thr  a<-r>11o  nf  //  will  onruny  ii  pmition  inilicnlinfc  ilic  puiaj(«  of  a 
WtraatofK  c«rt«in  iiiitiisiir  frocii  A  tu  A' ihruugb  the  nlvsnoniPtcr  (from  the 
MUivvlaticlludiiinl  Mrftice' to  tbe  ofigitiro  cut  «ud  or  the  nerve),  the  circoic 
Wlaf  e<MDpM*d  by  «  currcoE  ui  lhen«rre  ftvin  h'  to  A,  i. «..  tbe  currvnl  will  How 
l>  Um  lUnctioa  of  tbe  arrow.  t^imiUrl^  thv  n«odl«  of  0  will,  b^  iix  dcAactioR, 
Mkue  tlw  exlMcnce  of  ■  currenl  fluwinx  from  ^  to  jr*  tbruugb  tbc  Kalvunome- 
ter,  u»d  tnm  9'  toy  ihruugb  tli«  nerve,  io  ibc  directiixi  of  ib«  arrow. 

At  lbs  iaitKDt  that  the  poUrUln);  current  1*  tlirowii  Into  the  norve  at  ;>;>'.  tbe 

fwiWila  at  jm'.  AA'  will  undtrgo  a  "oqfstive  varintinn."  that  in.  the  nerre  at 

MCh  point  will  exhibit  a  "current  of  action"  ci>rrRtpniidinf:  I«  thu  ncrvoua  im* 

|«1m.  which,  at  the  mnking  of  the  polaririoK  current.  pOMUo  in  bath  direclion* 

■hMK  the  oerTo.  am)  may  csuM  a  oootraotioo  in  the  atlached  muscle.    The  our- 

nttt  at  action  ii,  as  wo  hare  teen,  of  eitrrmcly  short  danUion.  it  Is  over  and 

|MW  (a  a  mail  fraction  of  u  atcond.     II.  therefore,  munt  not  be  oonfounded  with 

sMnnaaani  effect  which,  in  tli«  cas«  we  iir«  deuliii^'  with.  !■  observed  iu  both 

pItaBiMMUn.    nia  ell«ct.  which  11  de|)t'iidi'rit  mi  the  directi'jii  of  ihe  |H>1arle- 

■(CWrml,  MM  follows;  .Supposing  tlial  tbc  polari/.ine  current  is  Hnwing  In  tb« 

Antdn  of  the  arrow  in  the  nftnro.  that  i«,  passn  in  the  nerrc  fmm  the  ixwilive 

Jmiode  or  anode  p  to  the  negative  electrode  or  kathode  //.  it  i>  Tounil  thut  the 

nrtvnt  tbroagh  the  g^VBtiooieier  O  ia  iacnaBcd,  while  tluil  through  J7k  dimin- 

xbid,    Tbe  (KiIariRlng  current  has  caused  tbe  appearance  in  the  oerTe  outside 

ihs4Klfnd^  of  a  current,  baring  tbe  wtme  direction  aj>  itself,  called  the  "elec> 

tntnir  "  current  -  nnd  this  e1«ctrotonic  current  mliU  to,  or  Ukn  nirsT  frirm.  the 

MMal  oerre-cttrrenl  or  "current  nf  rent"  sceording  at  il  is  flowing  iii  tbeaatne 

JbMieu  sa  that  or  in  an  opposite  direction. 

1W  iliwBitih  of  tbe  electrotonic  current  is  dependent  on  the  >lr«iiKth  of  the 
pahiiiliit  airreot.  and  on  the  length  of  tbc  inirs)>olar  region  which  is  exposed 
L  to  the  fUmtitiBK  cnrrent.  When  a  stmnit  potariiintt  current  in  used,  tho  eleetro- 
B  Hlln  fiwce  of  tbe  electrotonic  current  may  be  uiucb  |{re«tcr  than  thai  of  tbe 
■    aunl  Mr«»-carrent. 

H  Thi ttrencllt  of  the  electrotonic  currcnl  vsHm  with  the  Irritability,  or  vital 
H  rwsftliM  or  th»  n«rve,  being  greater  with  the  more  irritjtblc  nerve ,  and  a  dead 
P  Btm  will  not  nuniresC  electrotonic  current*.  Moreover,  the  propagation  of  tbc 
[^       uiJHsi  b  Mopped  by  a  ligature,  or  by  crushing  the  nerve. 

W*  najT  apMk  or  tbe  conditions  which  girc  rise  to  this  electrotonic  current  as 
a f  >>wH/el«€tro«oniu  nnalogoaa  lo  th*t  pliyiolngieat  elvetrotonus  which  is  made 
bna  by  variations  in  irrilaoility.  Tbc  phyiical  electrotonic  current  ia  probably 
fo  U>  the  aacaife  of  tbc  (Hilariung  ctirrcnt  along  the  uerrc  under  the  peculiar 
oadllleos  of  toe  Hrinf;  nerve;  but  we  oinit  not  allempt  to  enter  here  tiitu  ibb 
Wall  subject  nr  ini'i  tbe  allied  quoilion  as  to  tbe  riaci  connection  between  the 

apical  and  tbe  phyiinlogical  clectrotonu*.  though  there  can  he  tittle  doubt  that 
I  latter  la  dependent  on  the  former. 

(fl.  Tbaae  variations  of  irritahtticy  at  the  kath'xlc  ami  anode  reapec- 
Irwif,  IfaiM  brni)f;hi  about  by  the  action  of  tbe  coitstAiii  current,  are  inter- 
Ming  ihenrelicnlly,  boonase  we  may  trace  n  connecliou  between  ihetu  nur) 
tbi  ncrvow  iDipulae  which  la  the  reaiilt  of  the  making  or  breaking  nf  n 
tmtrnA  current. 

Par  we  have  evideitce  that  a  nervous  impulfte  is  gencniled  when  a  portion 
if  tbe  nerve  puaea  auddeiily  from  a  norniul  condition  to  n  Mnle  of  Icatclvc- 
tMsoBS  or  fitm  a  atate  nf  notilec-iruionu^  hack  to  a  uormal  euiuliiion,  but 
telka  panajfc  from  a  oorninl  <<ondilion  tn  aiiele«lralcuus  or  from  knti'lcc- 
inMKia  back  to  a  uomml  condition  Is  unuble  to  gvnernlc  an  impg|»e. 
Hoe*  wben  a  i^nslnnt  ciirri'iit  is  "roado"  the  impuW  is  gi-uvrati-a!  only  itt 
lla  kathode  where  th^  nerve  [HMtifi  ninldenly  inUi  kntelei'lmt'imi*;  when 
ttamrmt  on  the  other  hand  is  "  litoken  "  tbe  iiuputsc  in  gcneratcil  unlv  at 
■iUiand*  where  iJie  i»erve  |MtsiN.>e  suddenly  luick  from  aneUictrotonus  into 


THK   CO:?TYIAOTIt.B   TlSSCBfl. 


»  nomia]  oandilion.  Wo  have  au  imlin^t  proof  uf  iIim  in  ihu  Factii  lu 
which  ff«  <lrew  atteutiou  ii  little  while  buck,  rix.,  thnt  a  coiitrnctioD  aoine- 
liincs  oceuni  at  the  "  bre&king"  only,  MmHintcs  nl  the  "nuikio^"  only  of 
the  coD»lniit  currvnt,  tometimo  nt  hoth.  Fur  it  in  fotiml  thnl  thtg  ijcponds 
partly  on  tho  mrcngth  of  tho  current  in  relation  to  ttir  irritability  nt'  tbr 
iivrTc,  pnrtly  on  the  direction  of  tho  current,  whether  iiM;cn<liDg  or  ^csceiid' 
ing;  and  tho  results  obtained  with  Aitron;^,  medium  and  wonk  descending 
and  asronding  cnrrcnls  have  been  slnlod  in  tho  Ibrm  of  a  "  law  at'  cotitroc- 
lioii."  Wo  need  not  enter  into  tho  details  of  this  "law"  but  will  merely 
say  that  tlie  results  which  it  formulates  are  bc^t  oxplaine'l  by  the  hypocbe- 
eisjnsl  elated.  We  may  gidd  that  when  the  constant  current  is  applied  to 
certain  structure)!  comiKised  of  plain  niuitculAr  Kbrcs,  whose  rale  of  cnolrac- 
tion  we  have  seen  to  fa«  slow,  the  maklnf;  contraction  nmy  be  actually  ae^ii 
to  b^in  ai  the  kathode  and  travel  toward  the  aitode,  and  the  break'toff  oon- 
traction  to  bei^in  at  the  anode  and  travel  thence  toward  the  kathode. 

Since  in  katelectrotoDuii  the  irritability  ia  increased,  and  in  aneteolrolonua 
det-reaaed,  both  the  entraiii-e  from  the  normal  cuiKlilion  Into  katelectroioDiu 
aod  the  return  from  auelcclrotonua  to  the  normal  condition  arc  iiulanci^  of 
ji  uawajte  from  &  lower  Atage  of  irritability  In  a  higher  Htage  of  irritability. 
Hence,  the  pbenomena  of  electro  ton  iih  wnuld  lead  us  to  the  oonoepiiuii  that 
a  atimulutt  in  provoking  a  nervoun  impulte  pntduceH  itn  effect  by,  in  »oinc 
way  or  other,  suddenly  raising  the  irritability  to  a  higher  pitch.  But  what 
wc  are  exactly  to  uiidemtand  by  raising  the  irritability,  what  molecular 
change  i«  Ibc  («ti«e  of  the  rise,  and  hnw  either  electric  or  other  stimuli  cnn 
produce  lbi«  cliangc,  are  mutters  which  we  cannot  discniu  here. 

Bendw  their  tbuorvtic-al  im[i.irtiiine,  the  phenomona  of  electrotoou^  hare 
nita  B  practical  interest.  When  mi  iis<-cttding  current  is  piuwtl  along  a  nerve 
goiiig  to  a  mtticle  or  group  of  mus^le^,  the  region  between  the  electrodes  and 
tne  muscle  is  tlirown  into  anelectrotonti^  and  its  irritability  is  dimintshetl. 
If  the  current  be  of  aderiiialc  strength,  the  irritability  may  bo  »>  much 
teteened  that  nervous  impulses  cannot  be  generated  in  thai  [inrt  of  the  n«rn 
or  cannot  paea  along  it.  Hence,  by  this  means  the  irrejjular  contracliun*  ot 
muscles  known  aa  "  cramp  "  may  be  abolbhed.  Similarly,  by  brlngiuff  into 
a  condition  of  aneleotrotonus.  a  portion  of  a  sensory  nerve  in  whieh  vinleni 
impulses  are  being  generaletl,  giving  rise  in  the  central  nervous  syaicni  Ia 
scnaalions  of  pain,  the  impulses  are  toned  down  or  wholly  abolished,  and  the 
pain  c«BM«.  ^.  on  the  other  hand,  we  may  at  jtleasuru  heighten  lite  irrita- 
bility of  a  part  by  throwing  it  into  katelectnitouuii.  In  l£b  way  tho  con- 
slant  current,  pni)ierly  niiplied,  becomes  a  powerful  remedial  innsua. 

We  said  just  now  that  probably  every  ttimuIuH  produces  ita  tdaol  oq  a 
nerve  by  doing  wliat  ibo  conntnnt  current  docc  when  it  a<Ms  as  a  Stimulus^ 
vis.,  tuildrnly  raising  the  irritability  of  the  uvrro  to  a  higher  pitch.  At  any 
rate,  the  etimuluK  «o  ot^n  employnd  in  experiinents — the  induction-f bock- 
acts  exactly  in  the  mmc  way  as  tho  constant  current.  The  induct  ion -shock 
is  a  current  of  short  duration,  developed  very  suddenly  but  disuppeariDK 
more  grnduitlly,  and  thii^  is  true  both  of  n  making  induction  shuck,  a  shock 
due  to  the  making  of  the  primary  current,  and  of  a  bmking  shook,  a  abock 
due  tn  the  breaking'  of  the  primary  current.  The  two  dtHer  in  direction 
(beoce,  if  the  makinj;  shock  be  ascending,  tbe  breaking  shuck  will  be  deaccud* 
ing,  awl  viet  ivnvj ),  and  in  the  &ot  that  lite  breaking  shock  is  more  sudileiily 
developed,  and  hence  more  (loteot  than  the  making  shock;  but  otherwise 
tliey  act  in  the  name  way.  In  each  case,  nnce  the  induce<l  current  is  devel- 
uned  rapidly  but  diMpjiears  more  slowly,  there  ia  a  sudden  development  ot 
electrotonus,  of  kalelectn>t()nus  at  the  kathode,  and  of  anelectrotoiiun  at  the 
aaoiie.  and  a  more  grmlual  return  to  the  normal  condition.     Now,  ih«rc  are 


rnx    XUflCLR-NSRVB    FKEl'ABATION    AS   A    MACHINE.      196 


I 


muiy  rttmrnm  for  thinking  (hat  in  »)l  ohm  (he  jnauii};  horn  lli«  normal  uon- 
4idi>n  111  k»l«lwtroioniM  ■(  th«  knlli<x(c  is  a  nxjro  potent  siiiiiiiliis  than  tli^ 
ntani  (rtmt  antlectrotonna  to  tW  uurmal  cuuililloii  ai  ihi?  iiiiudi.',  and  lliia 
•ill  b»  itill  Biora  M  if  lh«  return  to  the  uormal  ritihlitiott  lio  much  «loiror 
tiuui  tha  entiancs  into  el«ctruionus,  as  ia  the  caae  in  iin  iii(tiictinn-#lu)cik. 
AimI  ii  wixtid  appear  that  in  an  intluciioii -shuck,  which,  lu*  wc  hiivomid, 
clHapjNvn  much  more  slowlj  than  it  ii  lievelnped,  wc  hiivu  to  'teal  nut  with 
two  atimuli— one  at  the  shook  |<ttAiinK  into  a  nerve,  and  one  at  thc*hiick 
IfBvinit  ibf  nerve— but  nith  aiw  uulc,  thnt  pruduoeil  at  the  thwk  passing 
tnUi  tlie  nerve,  ilenee,  irhen  itn  tnductiuii-sliock  in  mnt  into  a  nerve,  ono 
lus  unlj  is  develo|>cd.  and  that  at  the  kalhoJu  only,  the  eslnblishmeBl 
lUB.  This  iR  true  whether  tliu  #hock  be  n  making  i>r  a  brewk- 
__  dinek — I. «.,  line  to  the  inakiuK  or  brcnking  of  llio  primarr  current-- 
thnugfa,  of  course,  owing  to  the  change  "f  ilirvction  in  the  induced  ciirreal, 
•fast  WBB  the  kathode  ni  the  making  shock  booooiea  llie  aoodo  at  the  break- 
luahock. 

l^rily,  though  Iff  arc  doling  now  with  nerves  going  to  ran«clee — that  is 
\a  Mjr,  wilh  motor  iH-rvm  only— vf«  may  nild  that  nhal  ne  linve  said  about 
tlectroluaua  and  the  dvv<'lopBwnl  of  nervotis  impulses  by  it  appears  to  apply 
t^uallr  wall  to  Pttaary  nrn'ea. 
(  n.  In  a  general  way  niosciilar  fibr^^f  b*'have  toward  an  electric  etirrent 
r*  aiurli  nji  do  nervf  fibrt^  ;  but  (here  nre  certain  inijiorUmt  dilfervnc*^ 
In  Ibo  lirM  plnM-.  niupcular  fibres,  dermd  of  nerve  libra,  are  much  more 
rradilj  thrown  into  contractions  by  the  breaking  an<l  making  ol'  a  eouitanl 
niTTMit  than  by  the  more  transient  induction ■ehook  ;  the  muACular  Mib^tance 
iMia*  to  be  more  sluggish  than  the  nervous  sub6taiii.-e,  and  require!  to  be 
Mlad  npoa  for  a  hitger  time.  This  fact  may  be  made  ime  of,  aim).  ind«ed, 
ii  b  wdkal  praelice  made  mm  of,  to  del«rmine  the  comlitioii  of  the  n«rve« 
•■i)iplyiDE  a  muMrle.  I  ( the  intni-muAciilar  nervo  be  Mlill  in  gcMKi  condition, 
the  noMle.  to  a  whole,  rojionil*  nmdily  tu  single  induct  ion -shocks,  beoause 
ikae  tsa  a4;l  upon  tbc  inlra-muM-ular  nerve*.  If  these  nervtv,  on  the  other 
ka»'  I<wt  their  irritability,  the  muM'Ie  diMv  not  r<«|iond  readily  in 

aa^-  iua-«hucka,  or  to  thv  inta-rru ptt^l  i-iirrcnl,  but  can  still  easily  be 

ihiima  ink'  c«ntraeiii>nit  by  the  ci>n<4AnL  current. 

Id  liie  eeuind  |»laoe,  while  in  a  nerve  no  iiupulsos,  as  a  mie.  generated 
Joriac  tbr  |M«age  of  a  ountHnni  mrrenl.  between  the  brenk  and  the  make, 
fntun]  tliai  it  ia  not  ton  drong,  and  ihtU  it  remains  unilunu  in  strength, 
Ik  HI  urariznl  nin>M:li.-.  on  the  oilier  hand,  even  with  moderate  and  perfectly 
aaifiMin  rumrni*.  a  kind  of  tetanus  or  iipp«rently  a  series  of  rbytnmically 
NfBlcd  ctmtractioDs  ts  very  freiiiieully  wiinesKd  during  the  padsage  of  the 
•anal.  Tbe  exact  nature  and  cause  of  these  phenomena  in  muscle,  we 
■wt  >!«,  however,  diecuss  here. 


TnK   Mtr^iCLe-NERVK   PkBI-ARATIOX    ah   a    ?tlA(')IING. 


tYI.  The  &ct*  described  in  the  foregoing  tvelions ifhuw  lUatn  miit«le  with 
ikaenrc  may  hv  juKtIy  reganled  as  a  machine  which,  when  oiimnlated.  will 
^  1  eertain  unuMini  of  wurk.  Hut  (he  actual  amotint  of  work  which  a 
aowle-nrrvr  [>rfparat>oo  will  do  ts  ftuiiid  bo  depend  on  a  large  number  of 
■vaUMaDrca,  and  oi>nK»)Uently  to  vary  within  very  wide  limits.  Then 
wiatinns  will  be  largely  determined  by  the  condition  of  the  muscle  and 
Wn*  bl  rcapoct  to  their  notriliou  ;  in  other  words,  by  the  degrc«  of  irrita> 
tSqr  ■lanUeMei)  by  the  niitM.-le  or  by  the  nerve,  or  by  lM>th.  I3nt  quite 
■fart  tnta  the  general  influences  alfecting  its  nutrition  nttd  thus  its  irrilit- 


ISA 


THE   0OSTllACTIt,K  TISSrBS 


bililr,  n  muiclc'ncn'i^  prppnnilion  t!>  mflt-i'tt^I  nn  n-tfitrtlit  llic  ainnunt  of  \t» 
vrniU  by  a  variety  of  othrr  <'ireiitimtaD<<M,  ivhi<'li  vc  ihmv  bricHy  CAiintlvr 
horc.  rcsprviiig  to  it  «iiPOc^cliiig  mxIioii  the  oltiiiy  nf  vsrialixii!'  iii  irritnltilitv. 

Tlif  injlufriw  nf  (lit  nnlnrr  unii  madr  nf  njiplictlit>H  of  thf  utimnlm.  Wbrn 
WO  Apply  n  wcnk  etimului — u  -kv^M  in(fiiition->'hopk— to  R  nerv«  wc  gvt  a 
smnll  con  Unction,  n  «[ight  »)i'>ru-niii|i:  of  Ihc  ttiiiM-lr;  irhm  ire  npfilv  A 
8in>nt!Pr  etimrilii!— n  Hlrongtur  in<lucli<in*hiH'k — wp  gel  ■  lnrj»r  t-imniiclloo. 
a  fireutcr  »IiorlPiiiii^  of  tlio  iniisdc.  Wt-  Inke.  olh«r  lliings  Ining  cmiu&I,  the 
BiDdUDt  of  <.-oi)ti'aclion  nf  the  muide  iis  a  mmsuif  of  tbi'  nerroiis  imptilee. 
an<)  my  that  in  Ihe  forni«r  case  n  ivenk  nr  sli};hl,  in  the  InlU-v  cn^e  n  slmn^r 
or  liirgiT.  oervoui  impiilBe  \\\\%  he«ii  ;;i?neriiio(],  Xou',  the  mu»cl«  of  the 
inu^cle-nerve  itrepiirali'm  coii^iiilti  of  niuoy  nntscular  tibree.  niid  thft  aerVA  of 
uatiy  nerve  6brc«:  and  we  may  fairly  Buppnife  thai  in  two  ex[«rinenta  we 
may  iu  the  one  experiuieiit  bring  ihe  iutiiii^tion-ahock  or  oiher  eiimuliu  to 
Iiear  on  a  few  flbrea  outy,  and  in  ibe  other  experiment  on  many  or  even  all 
the  fibres  of  thf  nerve.  Iu  the  former  case,  only  those  muscular  fihreit  in 
vbich  the  few  nerve  tIbreH*[imulaleil  enil  will  be  llirowu  into  contract  ion. 
the  others  remuininj;  <|uict,  and  the  shortening  of  the  muscle,  aa  a  vltole, 
aince  only  n  fen  librMi  lake  pan  in  it.  tvill  neccnmnlr  be  1cm  than  ythta  all 
tlic  RbrcH  of  the  nrrve  arc  stimulad^l  and  all  the  fifireM  of  the  mnacle  con- 
tmcl.  That  w  to  Miy,  thv  amount  of  contractinn  wtU  d<-]icnd  mi  tbv  number 
of  librcf  stimulated.  For  timplicily'*  nake.  however,  we  will  in  what  fol- 
low*, exeepl  when  otlicrwicr  indicatMl,  mippn*'  ibnt  when  a  nerve  \*  otimu- 
lated.  all  the  fibres  ar«  Htimulated  and  all  the  miundHr  tihrri!  ronlract. 

In  »iieh  a  case  the  Mrongvr  or  larger  nervous  impulse  leading  to  the 
crmler  contraclion  will  mean  the  greater  disliirliance  in  each  of  the  nem 
hbree.  What  we  exactly  mean  by  th«  grent«r  disturbance  we  mu^t  not  dis- 
cura  here ;  we  must  be  content  with  re^nrding  the  greater  or  more  jKiwer^l 
or  more  intense  nervous  impulse  as  that  in  which,  by  some  mode  or  other, 
mora  energy  in  *ei  free. 

So  far  i»  we  know  at  pmunil  this  ilillen-'nee  in  anintint  or  intensity.  «f  the 
eacrgy  »rt  Iree,  is  ihe  ebief  diflerence  between  \-ariiWs  nervous  imiMilsc*. 
NerroUM  impulM-s  mav  diRer  in  the  velocity  which  they  travel,  in  tlte  length 
and  {NMsibly  in  the  form  i)f  the  impnlsi!  wave,  but  the  chief  ilill'erence  u  in 
Strength,  in,  su  to  speak  the  height,  of  Ihe  wave.  And  our  prexonl  knowl- 
edge wilt  not  permit  n*  to  point  out  any  other  ilifTereneee.  any  diflercnc«  in 
fundamental  nature  for  instance,  between  nervous  impulses  generated  by 
different  slimuli,  between  lor  example  the  nervous  impulse  generated  by 
electric  currents  and  those  genernted  by  chemic-ttl  or  mechaoieni  stimuli,  or 
by  lh<«e  changes  in  the  central  ner^'ous  system  which  (;ive  rise  to  what  may 
be  called  natural  motor  nervous  impulses  as  distinj^imhed  from  tlioee  pro- 
duced by  nrtilicial  stimulaliun  of  motor  nerves.' 

This  being  preutiseti.  we  may  any  that,  other  things  being  equal,  the  ma^- 
nilude  of  a  nervous  impuUe,  and  so  the  luagtiitude  of  the  enauing  conlraclton. 
ix  dirai'tly  dependent  on  what  we  may  tall  the  siren<;ih  of  the  stimulus. 
ThiiH  taking  a  single  induction -shock  as  llie  moat  manageable  stimulus,  we 
find  that  if,  before  we  begin,  we  place  the  secondary  coil  (^Fig.  14,  >en.  e.)  a 
long  nay  olT  the  primary  coil  nr.  r.,  no  visible  effect  at  all  follows  u|<on  th« 
discliarge  of  the  iuduelion-fiboek.  Tlie  pawage  of  the  momentary  weak  cur' 
rent  is  either  unable  to  produn-  tiny  nerroiis  impulse  at  all.  or  the  weak 
nervous  impulse  to  nhich  it  giv««  rise  is  unable  to  atir  the  sluggish  muscular 
Bubslanoe  to  a  visible  contraction.  As  we  slide  the  secondary  coil  toward 
the  primary,  sending  in  an  induction-shuck  at  each  new   position,  we  fiml 

I  U  will  hr  olwrrcil  thai  w«ara  sivakltia  nnw  vxrliiiirslj-nC  Ihp  iirrvv  (>f  n  KiUM'lij'nRte  tman- 
tlAa.l.r,  orvhii  >ic*l>uil  henmfli-ririm h inalni  iierrv.  WiudierKnwiylint'liliMiIIIIkrefficatiBlljr 
than  nuilor  iia|iii]t»  u  lU  la  fiiiiUrml  laim  »ii 


TnR    MUHCLK-XKIIVE    fKEI'A  It  ATIUN    AH    A    UACHIXE.      ISl 


k 


I 


lfa»l  at  m  reruin  diflUoee  between  theEMmodarv  itii<l  pHniiry  coils.  tht>  tiiui- 
Hr  nmftendt  In  Htcli  itiilufliou-shiMilc'  wil'i  a  coutniction  which  ninkc^  ilMlf 
viijble  in  Ibe  ■[i)[)i[«M  |Kjet»ible  rise  uf  ihe  ik(iacl>i>d  lever.  TIiih  pavilion  of 
lbs  onib,  tlw  hnlU'ry  rrmuiiiinf;;  tii«  tame  and  oiliur  thin^  IwiBjf  e(|iinl, 
■Mrfc*  Ihe  wini'miiV  niiuulus  jfiviiiK  riae  W  the  ruiuinial  iM:intraclJi>n.  Aa  the 
■Mooilarr  mil  i.-<  Im'UKlii  nearer  to  the  prinuirv,  (he  ci^ntracltoiM  increiwe  in 
Iwigbt  cnfTiM|»tiJiii>:  ti>  ibe  UiervHM  iu  the  iHU-nnily  of  the«tiniiilu!i.  Wry 
aoaa  hammtr  na  incmiiH;  in  the  MimuluN  Cftiued  by  furihrr  cliilinK  >1k- 
MCMwianr  coil  ovr>r  the  primnry  failK  to  enuM  anr  iricrvuw  in  thv  oritrniv 
lioii.  Tbi*  iiidii'at'i  that  tbv  Majrtm'i/Mimiitnit  ^viiiji  Hoc  to  ihu  niaitimnl 
«aati»cliun  htu  If4'«ii  rvuchw) ;  thougb  the  shoclut  incmiw  in  inCvtmily  a« 
the  wcoadary  ooil  i*  pudNd  furtber  and  riirthi-r  over  Ibe  primary,  the  con- 
tnrtlona  mnain  »t'  the  nine  height,  until  fuiiguo  lower*  them. 

With  «ingle  indiK-tian-sliocks  llien  tht-  miiKruliir  contraotion.  aD<l  by 
iaftrmce  tlw  nervvtu  iiapulM.  incn;af>v»  with  an  incroiiw  in  tbe  intensity  of 
the  ititDultW,  bMireon  the  limit*  of  the  minimal  and  iniisinial  uimuli ;  and 
lUf  dMMSwkKUie  »f  the  nervous  impulse,  and  so  of  ihe  contractioo.  on  the 
MTCogtA  of  tbe  stimultis  may  l>c  oWrve^i  not  only  in  eleetrio  but  in  all 
UiMb  of  Mimall 

It  mavhera  b«  remarked  that  in  order  for  n  stimuluH  to  beetl^tire,  a 
<*TUin  atm[ADeBS  in  its  cetion  is  oeoeaaarT.  Thus  aa  ire  have  »een  the  con- 
>L>nl  ctinvnt  when  il  b  fMAinj;  throcigh  a  nerve  with  uniform  inleiiitity  does 
Mt  pvi;  riae  to  a  nen-oua  imputac.  and  indeed  it  may  lie  incmiiKil  or 
<fiMini»he<l  to  aluwet  any  extent  without  ftenerulin^'  nenvma  impiiUta.  pro- 
vUmI  ifaai  tbe  ehange  be  made  (•radually  eiioujch  ;  il  t^  only  when  tlterc  'i» 
■  addon  «bMi|{e  that  the  current  beonmen  eHi.>4:live  ns  a  miraului'.  .\iid  llie 
ntmto  why  tbe  breakiii):  induciion-sliuck  in  murL-  piient  iu>  a  miniidu*  than 
the  malcing  «back  is  bcxaitu>!  an  we  luive  sorn  i  M-t  >  (he  current  whii-h  ia 
iMlncwl  in  thr  MVondary  coil  of  an  imlurtion- machine  at  the  breaking  of  the 
(mmary  circuit,  is  mon  rapitlly  (level<>)xi(l,  and  has  n  sharper  rise  than  the 
tarrrnt  which  ap|>rAre  nhi^i  tbe  priniary  circuit  in  made.  Similarly  a  sharp 
lafi  r>n    a  nvrre  irill  pmdu<?c  a  contraction,  when  a  gradually  increouiig 

Iiiwaurv  will  fnil  to  do  so  :  ami  in  evnenti  the  efficiency  of  a  atimulua  of  any 
,iad  will  depend  in  pan  on  the  MiJdcDnesa  or  nbrupln«ee  of  its  action. 

A  •tiinuliis  in  ortlcr  that  it  may  be  effective,  muat  havo  an  action  of  a 
ivrtaiu  itiimlion.  the  time  ncceeeary  to  produce  an  effect  varying  according 
In  tbe  strength  of  the  •tiiiiulus  and  beiuf;  ditlWreni.  in  the  case  of  a  nerve 
IVnm  wbnt  it  ia  in  thecMeof  a  muscle,  [t  would  appear  that  an  eUtrlnccur- 
not  applied  to  a  nerve  muat  have  a  duration  of  at  Wet  about  O.UOIS  *etv>ii<l 
In  oiuap  any  nintraciion  at  all.  and  needi  a  longer  time  than  iht*  to  produce 
ill  Atll  effect.  A  muac-lelibre  a|>aTi  from  its  nerve  fibre  re>)uires  a  &u]l 
kdgcr  duration  of  the  ttiiniulua.  and  henee,  u  we  have  alreiidy  rotated,  a 
■iMde  puiMUt^l  by  iirari.  ornhieb  kaa  otltcrwiM  loM  the  acliiin  of  iu  uerves, 
■ill  n«i  rupcxid  an  readily  to  inductiou-sfaocka  as  to  the  more  slowly  acting, 
hlMtkiog  and  making  of  a  conuant  current. 

Ib  Um  om  of  clirclric  uimuli.  tbe  Bamc  current  irill  prwluoe  a  stron|^ 
nMraetiMi  wh<m  it  ia  *ent  along  t)ie  nerve  than  irbuii  it  ii  aent  aerom  tbe 
wnre:  indeed  il  ia  mainminiMl  that  n  current  which  {Mate*  tbrougli  a  uerve 
b  n  ahtolufly  tnuufvenc  directiun  in  ]>on'CrlM»  Ui  generate  impuuea^ 

It  would  aU(>  nppMr,  at  all  evcutN  up  to  certain  liniltji,  that  the  longer  tlie 
(inr  of  nerve  through  which  the  currviit  poase*,  tbe  greater  is  the  eifect  of 
lieMimtilii*. 


._ Mihtv  ikt  WmUiit  w  nuKUiaikoekBreMkeBied.  DM  iMSFtlmw  c—  aal 

«•  oikrr.  a*.  M  !*•  luin  <MU>d,  Ibv  Irni  U«d*  uf  ikMk  dUftn  Iu  dlDcttocT.  Ik*  bnaklaf 
(to  BM*  fDiani 


188 


THE   CONTRACriLB   T1S8UBS. 


When  twu  pain  u(  electroden  itre  pincod  on  the  nerv«  of  n  long  uirl  per* 
fealy  l're»h  mid  Hucoeuful  Derve-pr«]»t ration,  one  near  to  the  cut  end,  and 
the  other  nearer  the  muscle,  it  in  round  thnl  the  Htmc  vtimuiiis  producee  a 
gre»(cr  contrnclion  irhen  iipplied  through  the  former  pair  uf  electrodes  ihtia 
ihiMu^h  the  latter.  This  has  been  interpreted  as  meaning  tliat  the  impulse 
Staiteit  at  the  further  eleclrodee  |^the»  islrengih,  like  an  a\'nlaiiehe,  in  ila 
progreaii  to  the  mu«cle.  It  is  mom  probable,  however.  Chat  the  larger  con* 
traction  produced  by  Himiilatioii  of  the  pari  of  the  nerve  near  the  cut  end 
is  due  to  the  stimulus  !<ettiiiK^f<^'!  a  larger  impulse,  i.  e..  to  tliii  part  of  tha 
npTve  beinj;  luun?  irritabk-.  The  men  seotion,  possibly  hy  deTelopttiK  ii«rvu 
currents,  luirreaitai  fur  a  lime  the  irritability  at  the  cut  end.  A  .similar 
l^reaier  irritability  mav  honever  nl«o  tie  observed  in  tho  ptirt  of  the  uem 
nearer  the  ipinul  mrd  while  ii  ix  mill  in  oonucctioii  with  the  spinal  cord  ; 
ami  it  ia  pus^ibli:  ihut  the  irritnbilily  of  a  nerve  nuiy  vary  oon«i<lerably  at 
dilfereDt  puiniit  of  it^i  c'iun>c. 

$  60.  We  have  luvii  that  when  oin^Ic  xtimuli  aru  ntpcated  with  Kullicient 
frei)iiency,  the  individual  coiitrnction*  arc  fuied  tnli>  tetanus;  nc  the  fre* 
queiicyuf  the  ropotition  is  incrc4UH^,  thu  individual  oonlraolions  are  leas 
obvious  tin  the  curve,  until  at  last  wo  got  a  curve  on  whifh  they  iwcm  to  be 
entirely  lotft  and  which  ne  may  qwak  of  n»  a  complete  tetanus.  Br  such  a 
tetauuit  a  much  ^Evter  contrnclion.  a  much  ^rvalcr  shortening  of  tl>e  muscle 
U  of  course  obtained  than  by  sin^ilc  contractions. 

Tbo  exact  IreijUcncy  of  repetition  rcijuired  to  produce  complclc  tetanus 
will  depend  chiedy  on  the  length  of  the  individual  contractione.  and  ihia 
Taries  in  different  aniuiaia.  in  dilferent  niuiclcs  of  the  same  animal,  and  in 
the  tame  muscle  under  ditferent  condilions.  In  a  cold'blooded  animal  a 
dngle  contraction  is  as  a  rule  mure  prolon^^d  than  in  a  narm-blooded  ani- 
mal, and  tetanus  is  caiise<iiifntly  piuduced  in  the  former  by  a  lea*  ft«>|uent 
repeUtion  of  die  utimuluti.  A  lirml  muscle  has  a  longer  contraciton  than  a 
freah  muscle,  and  hence  in  many  Ivljuius  curves  the  individual  ontrnctiona. 
eauiy  reci))(ni/i,il  at  lirst.  dieiip{H'itr  later  un,  owing  tn  the  individual  contrac- 
tions belli)!  It-n^thcned  out  by  the  exhaustion  ciiii»cd  by  the  telanu*  itaelf 
In  many  niiiiunT»,  p.  7.,  the  rabbit,  somi^  musi-lis?  i.siich  as  the  adductor  mae- 
nus  fciiiorin^  arc  paio,  while  other*  (such  n.i  the  «emiicn<lino«iis)  are  rea. 
TIte  Kid  muitclnt  arc  not  only  mora  richlysupnlied  with  bloodvcwcls,  but  the 
muscle  suli»innc«  of  the  fibres  ooutains  more  nwraoglobin  than  the  pale,  and 
there  arc  other  etnicturnl  dilI«rcneeB.  Now  tho  single  contraction  of  one  of 
thaw  re<)  muj>clcs  is  more  prolonged  than  a  single  contraclion  of  one  of  the 
{Mite  muM-les  produc-ed  by  the  same  stimulus.  Hence  the  red  muscles  are 
ibiuwn  into  complete  tetanus  with  a  repetition  of  much  less  frequency  than 
that  rcijuircd  for  the  pnle  nmaeles.  Tlius,  ten  stininli  in  a  second  are  qnit« 
sufBdcnt  to  throw  the  red  muscles  of  the  rabbit  into  complete  tetanus, 
while  the  pale  inusclot  reuuire  at  least  twenty  stimuli  in  a  second. 

Ho  long  sa  signs  of  the  individual  contrai-'tions  are  visible  on  the  onrra  of 
teuuius  it  is  easy  to  recoguiiii!  that  each  Htiiuiilation  priidueix  one  of  tli«  cou* 
Miluenl  single  contrmrlionH,  and  Unit  the  number  su  to  .4{iLmk  of  thtt  vibra- 
tiofis  of  the  muscle  making  up  tht-  tetanus  correniiouiU  to  the  number  of 
stimulations;  Imt  the  <^u(»tinn  whether,  when  we  increiuH'  the  number  of 
stiiuulatiuns  l>eyond  that  iiccmiary  to  produce  a  complete  letanuK,  we  still 
increase  the  nnniWr  of  rtm^titm-ni  single  contractions  w  one  not  so  easy  to 
answer.  And  connected  with  this  r|U4«tion  is  another  diHicult  one.  What  is 
the  rule  of  regietition  of  single  contraciiims  making  up  thow  tetanic  contrac- 
tions which  us  wo  have  »aid  are  ihi;  kind  of  contntctions  by  which  thevolnn- 
tan-,  find  indeed  otlicr  natiirnt,  movement*  of  the  body  are  carrieil  out? 
WW  is  the  evidence  that  lIick-  are  really  tetanic  in  character? 


J 


I 


TIIC    HL'SCLB-XEBl'K    fHHPARATION    Aft  A    MACUINK.      189 

WbsD  a  mwde  is  lUrowu  into  teuiiuii,  «  wore  ur  lew  iniuioM]  Mnnd  li 
prixlucnl.  Thb  may  be  heard  by  upnlyiD)r  a  M«Uwwopc  dirwtly  ovtr  a 
floBirwrttu^  lauaele,  and  a  dmilar  aouoa  but  uf  a  more  mixixl  origin  and  ka* 
iraMwoctky  may  be  heard  when  tlte  maixeicr  iiiUNcle*  are  furvibly  conUmcud 
or  «beB  ■  finger  ii  placml  iu  tl»e  «ar,  ami  iliu  muscla  of  ibe  Mine  ann  an 
eootneUd. 

Wbfa  the  M«ihoaoofi«  b  plan<l  over  a  Riu*clv,tbvnorvoof  whicli  iHvlimu- 
Istad  by  Miicii<<ii»liod(a  repeated  with  viirviiii>  rrxviui-ncy.  llii<  itotc  heard 
vQI  vary  wiib  tlii-  iroqucncy  or  (he  ihiM'k*.  Wing  of  hie\ivr  pitch  wtlh  Ura 
moro  rr^«lu*^ut  ■hwlc*.  Now  ic  ha*  bwn  thought  ihal  Uii-  Tihntti'Mtc  of  tho 
muack  giviii);  riw  to  Uw  "  inutoU-  Miund"  arv  tdniticaJ  with  ihv  liitgk-  con> 
uractioDN  making  uit  the  tvtttniui  of  tho  n>u»cK  Aod  eiiit.-o,  iu  the  luimnn 
body,  when  a  luuacle  i>  thrown  into  (.-onlnictioQ  in  n  voluntary  cITori,  or 
incHad  in  any  of  tb«  ordinary  natunil  movi.-menle  of  the  body,  (ho  funds- 
meatal  tone  of  tb«  sound  oorrmponds  U>  about  Hi  or  20  vibrations  a  Becood. 
it  ha*  bera  eoocludnl  that  the  contraction  takinc  place  in  eucb  cnsee  ■•  a 
'T^f  Ttr  cf  which  the  inilividuat  coolniclionH  fottow  each  other  about  19 
or  20  llaWi  a  c«4.'ond.  Itui  invntij^nliona  st-eni  to  show  that  the  vibrnlionB 
giviag  rne  to  the  muscle  sound  do  not  renlly  correepood  to  the  9hon«iun|p 
aad  nlaxaiioiu  of  the  individual  contractions,  and  that  the  pilch  of  the  note 
maooL  tbereface  bs  taken  as  so  indictiiioii  of  the  number  uf  ^iugle  vontrao* 
ligae  BUtking  op  the  tetanus ;  iiidee^l,  ait  w«  nlmll  ba  iu  iij)eaking  of  the 
MMiMfa  of  tlie  heart,  a  single  muMular  contruciiou  may  produce  a  sound 
■Uch  tboggh  dilleriotf  fruui  ih«  »ound  given  out  during  tvtatiu*  has  to  a 
BNlain  axtent  mueicaf  olioracterB.  Neverth6l«n  the  ;i|>ecinl  cbarHctcr*  of 
Ihk  noMle  Muod  ^ven  out  by  muwlee  in  the  nniural  movcmi^ni*  uf  the 
body  may  be  taken  es  showing  at  leut  that  the  contniotiomt  of  the  mii*clc 
a  Umm  Biovementa  arc  Ictaiiic  in  nalnra,  and  tho  stmilnriLy  of  the  note  in 
■U  Uw  voltintary  eflbrta  of  tho  body  and  itidwd  in  all  niovements  carried 
out  by  the  central  nervons  system  is  ai  \ftut  consonant  with  the  view  that 
tW  rvptrtitioo  of  sinck  contractions  is  of  about  tlio  Mme  fret|uency  iu  all 
(bar  niiiTenienis.  \\  hat  that  frec)uency  is,  and  nhclher  it  t<>  cxaetiy  ideiiti- 
ral  in  all  tbeM  movements,  b  not  at  pnsent  perhaps  absolutely  determined  : 
b(t  OBTtam  mrkinjp  on  the  my<)>craphic  tracing  of  thew  uoveweutti  and 
olltar  Iwu  eeem  to  mdicaie  that  ii  is  about  I J  a  second. 

I  BL  7%e  itijiuenee o/ Ike  tond.  It  might  be  iniagioed  lhal  a  muscle  which, 
«bcfi  loaded  with  a  given  weight  and  stimulated  bv  a  current  of  a  given 
iairtuity,  had  coniracietl  to  a  certain  extent,  woul<f  only  contract  M  half 
lluU  rxt«ut  wbeii  loaded  ailh  twice  the  weight  and  stimulated  with  the  huoh! 
ttfliahia.  Such,  howi-ver.  is  not  neoesurity  ilie  case ;  the  lieight  to  which 
tW  weight  b  ni6vt\  may  lie  in  thv  second  Inatanoe  as  great,  or  even  greater, 
ikan  in  thv  fint.  That  b  to  say.  the  neeistance  ofTcfeil  t<>  ilio  coniractioD 
sttuallr  auiimentd  tlte  ooatiaction  ;  the  tensiou  of  thi-  muscular  fibre  iucreosea 
ite  Csnlity  wttli  which  tho  csploMvc  chaiigex  nstulting  in  a  oontrnctiou  take 
fhra.  And  wc  have  other  evidence  that  anything  which  ti-nds  to  stretch 
the  muacnhir  fibres  ;  that  luiv  tennioti  of  the  mu*cutnr  ttbrvH,  whether  during 
Mt  or  during  contraction.  increaM«  the  motalMlism  of  the  muMlc.  There 
Kof  cvtirv,  a  limit  tii  thi*  favorable  action  of  the  resistance.  Aj  the  load 
cNitimits  to  be  incrtaM'd,  tho  height  of  the  contraction  is  diminbhu'l,  aiul  at 
Isai  a  point  b  reached  at  whicli  the  muscle  ii>  unable  'oven  when  the  stimulus 
ibosra  b  ihasiroogeMt  poaiibU<)  to  lift  the  loiwl  at  all. 

la  a  musclSTMwed  as  a  machine  wr  have  to  dcjil.  mH  merely  with  the 
W^bl  of  the  contraction— that  if,  with  tho  amount  of  xhortcniitg — but  with 
'•wnrit  dtmek     Aod  this  is  measure*)  by  multiply inj;  the  tiiimber  of  units 

LM^t  to  which  tlw  load  a  raised  into  the  nuiiiber  of  nnitu  of  weight  of 


140 


TUB  C0NTBAC1 


u 

K 

lOO 

IM 

IMC 

ffiO 

It 

• 

T 

a 

1 

u 

tJ 

•W 

Tl» 

tw 

«w 

u 

tbe  load.  Hence,  it  ia  obvious  fVom  th«  foregoing  observatioaa  that  the  wor 
done  moat  be  Inr^ly  tlepciKleiii  on  tlie  weight  itwtf  Thus,  there  b  n  certuin 
wcijfht  ijf  lotid  with  whi<:!i,  in  any  given  luuule  Btirauliit^l  hv  a  i^veu 
BtiiniiliiH,  the  incut  work  will  lie  done,  aa  may  foo  Men  iVom  ih«  follnwiDg 
examfile : 

Ijnil.  Ill  eni.iiiiii«* 

Haiubi  or  oonmcatm.  In  inlUIuiMna  . 
WwliU'JiM,  III  grmni'inllUniuLrai   .... 

i  8S.  The  ttijlumi^  0/  Iht  mxe  and  form  of  the  mvtele.  Since  all  liuown 
mutciiliir  liliTTfl  arc  much  ehorier  than  the  wavo-l?ngth  of  a  contraction,  it 
is  ohviouH  ihsc  (he  lon^'«r  the  tilin?  ihe  grenter  wit!  bo  ihe  sborlening  ciiu»ed 
by  the  mine  contnictiori  wiive ;  the  i>realer  will  be  the  heighl  of  (he  con- 
Iraetion  with  the  mtnv  itiiitiiiluH.  Hence,  in  n  niuecle  of  pariillel  tibree,  the 
hd^bt  to  which  tlie  louil  in  rained  nii  the  result  of  a  giren  fttimulus  applied 
to  Its  nerve,  will  dejiend  mi  the  tenj,'lh  of  ihe  fil)r«e,  while  the  nMisinium 
weiirht  of  load  <:ii|)ttbli<  nf  lining  lilted  will  ilepend  on  (he  number  of  the 
fibres,  ^imt  the  loud  i.-<  dintriliulcil  among  them,  uf  two  uiusclee,  tliereCore, 
of  equal  length  (iind  of  the  mme  nunlity)  the  ranet  work  will  be  dune  by 
that  whirh  hnn  (bn  lnrg<-r  numlM^r  ol  librai ;  that  ia  (o  aar,  the  6bree.  being 
of  e>|iial  width,  which  ha*  thr  ^reiitiT  Hcctional  area,  iiud  of  two  musclea 
with  eijtial  MOlionnl  arcu.".  the  niont  work  will  he  d<ioe  by  that  which  ia  the 
loufj^r.  If  the  two  muKch-K  iirc  unrcjiml  both  in  length  mid  actional  nrea, 
the  work  done  will  hu  th«;  grcntor  in  the  one  wbith  hiia  the  larger  bulk, 
whii'h  contain"  (he  grvntcr  niimher  of  cubic  unilit.  In  xpi-aking.  ihcrrfnre^ 
of  the  work  which  cnn  Iw  done  by  a  muscle,  we  mny  uki-  il->  n  Miindaril  a 
cubic  unit  of  bulk  :  or,  the  dpccilic  grnvity  of  the  mu.idc  being  the  Mimo,  n 
nnit  of  weight 

Wo  lourn,  then,  from  (he  foregoing  paragraphs  that  the  work  done  by  a 
niui'cte' nerve  prepanilion  will  dei^end,  not  only  on  the  nctivity  nf  the  nern 
and  muscle  as  detenuined  by  iheir  own  irritability,  but  tiho  ou  the  chnmcler 
and  mode  of  applteutlou  of  the  Rlirnulus:  on  the  kind  of  con  traction  (whether 
8  single  eiia^ni,  or  a  sKiivly  re)>eated  or  a  rapitlly  repe&led  tetanna)  o«  (he 
load  itself;  and  'ui  the  »mi  and  form  of  (he  muscle.  Taking  (he  iiioel  Ihror- 
able  circuniNlanci-ti,  vix.,  a  well-nourikhed,  lively  preparation — a  maximum 
uiniuliiM  caiuinga  rnpid  tetunux  and  an  appropria(e  load — we  may  deter 
mint?  the  maxininni  work  done  by  a  given  weight  of  muscle.  «ay  one  granirne. 
Thift  in  thii  i:nM!  nf  ihc  niuHcU-i*  of  the  frog  has  been  estimated  at  about  four 
grani-nietre»  fur  one  gramme  of  niuide. 


Tin:  CfUfUMHTASCKS  WIIICEI    DlH'KKMlSi;  TItE   DkUKKR  OK  IltltlTAUILITY 
OF   MVUCLKS   ASU   NeRVIM. 

*i  83.  A  muscle- nerve  pret>aration  at  the  time  that  it  is  rcmored  from  the 
body  [KMUMaci  a  certain  ilet;r^<e  of  irritability ;  it  rc^^ponds  by  a  contrat-tiou 
of  a  ct^rtain  iiniouDt  (o  ■  atiniuluH  of  a  certain  slren^'lh  applied  to  (he  nerve 
or  to  the  muscle.  After  u  nhilc^  the  exact  period,  depeu<Iiag  on  a  variety 
(if  cireumstaiiccD,  (he  xnine  Ktimuluo  pmdueei^  a  smaller  contniction  ;  ■'.«.,  the 
irri(abili(y  ol  the  prepanitiuu  ha:>  iliminlKlied.  In  other  words,  ibe  muade 
or  nerve  or  both  have  become  jiurtiiillv  "  exhausted,"  and  the  exliaustion 
Buhwinently  incrrn«ca,  tbu  luuiie  stimuliin  pnidiiciug  smaller  oun tract ious, 
until  lit  last  all  irrlUibility  i*  l<»t,  no  ^timiilnn,  however  Ktroug,  pniducing 
any  contraction,  wlicihcr  appliitl  to  the  iKiri'e  or  din^itly  to  the  muH-le  ;  tuid 
eventually  the  muFcIc,  tus  wc  have  mi:.a,  become*  rigid.  The  pnign^to  of  lhi» 
exhaustion  it  more  rapid  in  the  nerves  than  in  the  niusclca;  for  some  time 


iXflRIE   OP    IRRITABILITY   OP   MlfiCLES    AND   SKKVKS.      141 


\ 


\ 


•the  DtTW-tnink  Km  ctattd  to  raepoiid  to  even  the  «troD)i[fist  slirnuluB. 
tractioDi  niftv  Iw  obuincd  hj  apptrinf;  iho  stimulue  directly  to  tlie  diiib- 
«)&  It  ia  much  more  rapid  iti  ihu  wsnii-hlnuiled  lliiin  in  lh«  o<ild-l>liii>i]c<) 
■ni— bi  TIm  muscica  and  nervi^a  of  tbu  former  low  thi^ir  irritability  when 
naDBTod  from  the  body,  tSter  a  period  varyiog  MCcorditiL'  to  droumntaiiocK, 
ftwB  a  few  iDiDuta  to  two  or  three  boun;  thoae  of  cold- blooded  luiiniiilii 
(or  «  Icut  of  an  amphibian  or  a  reptile)  mav.  onder  f«vonblc  conditiutiH, 
ivautia  irritable  for  two,  three,  or  even  more  ilaya.  Tbi;  duralitui  of  irrita- 
bilU;  in  warni-blaoded  animaU  m»r.  however,  be  coiividerably  pn>UMigod 
bjr  ivduciug  the  temperature  of  the  Dody  before  death- 

If  with  aocne  thin  \>odj  a  Bharfi  blow  be  ttniclc  acruM  a  miucle  which  linn 
•(Htf«d  lato  the  later  *i(agw  of  (•shaumioa  n  wheal  laalin^  Tor  ai-veral  *ecr>ii<U  U 
4«««loptd.  Thu  wheal  appcani  la  bt-  a  cODtraction  wave  liinilcd  iti  tbi'  pnrt 
atrttck,  aad  diaappearing  very  «towly  without  extending  to  Ihc  nciubbnriu^  luua- 
•alar  Mihetaitce.  It  haa  been  called  an  "ii/ta-inunfyar''  mutraclmn,  because  it 
■af  ha  bmaghl  out  evea  when  ordinary  Mtimoli  liaTeceaaed  to  produce  any  elTcrt. 
Il  ■•¥.  bowever.  be  accenpanted  at  it*  bffpnning  by  an  ordinary  coutraction.  It 
b  nMWr  produce<l  in  the  livinic  body  on  the  pectoral  and  other  mtuclea  of  per- 
ana  anlMing  from  phthlab  and  other  exliaujitirig  diaeaaes. 

Tht#  natural  exhauniou  and  diniinutioo  of  {rrilnbility  in  mii»c)e#  and 
■errea  removed  from  the  body  may  be  modilied  Imib  in  the  rum  of  the  aiue- 
de  and  of  the  nerve  by  a  variety  of  drcumnljinoe*.  Similarly,  while  the 
arrre  aod  muacle  Mill  remaio  lu  the  body,  the  irritability  of  the  one  or  of 
th»  olbcr  may  be  inodified  eiilier  in  tlie  way  of  inerca^c  or  of  decrcR^e  by 
eanain  general  influeucea,  of  which  the  niuat  important  are  acveratice  from 
iheccDirmI  nervous  ayMem  and  variatiooa  in  tem|>enilun),  in  blood-mpply 
tttd  in  functional  activity. 

n*  rffft<»  of  tefmnct  from  the  etntrai  nerwuu  tfftietn.  When  a  nerve, 
fudi,  tor  inauuifle,  ••  iJm  aciatic,  is  divided  in  tUu.  in  the  livins  body,  there 
»,  flist  of  all.  olMwrvod  a  alight  incrcAH-  of  irritebiliiy,  noticeable  eapcciftlly 
tmx  llw  eat  end.  but  after  a  whilo  the  irritubiliiy  dimtnbhee  and  gmdually 
fcyHiWra.  Uuth  the  slight  initinl  incrcaw  and  the  Bub«(]uent  dccreate 
bpa  •!  the  col  ntd  and  advance  cctitrifupnily  toward  the  |Kiriphcral  ter- 
■ftalinmi  This  ccniriln^al  fcuUire  of  the  Iom  of  irrilidnlity  ih  ofti'ii  spoken 
<f  M  tbe  Ritlcr-Valli  law.  In  a  mammal  it  may  he  tu<t  or  l\\TW  ilavx  :  in 
tfrog,  aa  maJiT.orevcu  more  week^.  boliire  irriiabilltr  hiu  duiapiicurcil  friiro 
the  Derre-trunlt.  It  is  mainlaine^I  in  tlie  >imali  laiid  utpv-^cially  in  tbe  intra- 
nntcalar)  braodHa  fin*  Mill  loiifjer  periixie. 

Thb  oentrifb^  Iocs  of  irritubility  ia  the  forerunner  in  the  i>eriphera] 
wrtioo  of  ibe  divided  nerve  of  airuetural  chanif^  nbich  proceed  in  a  sini- 
W  centril'uptl  manner.  The  medulla  Miflera  ^uu))cea  iumilar  to  thoae  seen 
fa  Dcm  llbrea  aA«r  removal  from  tbe  body;  Its  double  contour  and  its 
ehanuitariatic  indentations  booDme  mure  marked;  it  breaks  uti  into  small, 
imgvlar  fracmenta  or  drops.  Mingled  witJi  the  fat  particles  of  the  m4Nlulla 
at  aaan  amaJl  DUUi»  of  pnitcid  material,  which  appear  tii  Ih-  derived  from 
iha  proloplaam  around  tlw  nuclei.     Meanwhile  the  axis-cylinder  also  brealti 

Sinto  IVai^nMtita,  and  the  nuclei  <>r  the  DMirili-mmu  divide  and  multiply, 
r  bitty  (-KUiitituenla  wbaoquently  dc^-reoM-  in  amount,  tbe  prolcid  material 
iacnaaiog  or  not  dinnnishtne.  aihI  thus  the  contents  of  tbe  neurilemma 
htavan  each  two  uodm  is  reduced  to  a  mass  of  protrid  malcrial,  in  which 
tte  f^agmeota  of  tbe  aiisHjjliiider  can  no  longer  be  reooniiaed.  This  man, 
tbich  sUl)  rMaina  sonia  tat  globules,  is  studd^  with  nudei.  If  no  regcner* 
itioa  tak<«  place  theeo  nuclei,  with  ihfir  proteid  hc^l.  eventually  dinpjtear. 
Id  the  cctttrul  porttoo  of  the  divided  ucrvir  similar  cbangen  may  be  tracetl 


142 


TU£  CONTRACTILE    TISSUES. 


M  tttV  only  M  tbe  next  node  of  Ranvier.  Beyond  thk  the  oerre  unielly 
remiiili*  in  H  nunnul  con  il  it  ion. 

RweueriiLiun,  n'hi-ji  it  iircuni,  iit  njipiirvutlr  cnrriM]  ant  hy  lliv  pcrijihvrnl 
pvtwin  of  till!  uxis-iyliuilrni  of  llii!  iutjit't  o<»itrul  porlion.  WIk'II  tliv  cul 
endu  of  the  aurw  an*  clmw  top-thcr  the  iisiK-oylimlont  grawingout  froiD  the 
c^nlrnl  [wrtion  niii  into  uuA  lii-twci'ii  tliv  *hnink(^  ncurilMQmBa  of  the 
IwHphrnil  |H>rlinii ;  hut  iniicli  iin<'i>rliiiiily  »tiU  cxii>l»  u  to  the  enact  nnrt« 
wliicli  the  prolirrrnlcd  n^^iiclfi  iiml  llic  proleiil  mntvrinl  rcftirred  to  abore, 
fltid  tliv  iiUI  nxi^'L-ylinilcrB  of  the  pcnphornl  p.irlioii  respeoiively  play  io 
jfiviiic  rieo  tu  the  new  stniclurc*  of  the  rep'nprnlod  tiltro. 

Saon  a  degCiieTatiun  mnr  bo  uWrved  to  ^xteiid  down  to  the  very  endings 
of  the  tierve  ici  l)ie  mii§cle,  iDeluding  the  end-plnte»,  but  does  uot  at  firsi 
atfect  the  inuBL-iiltir  eiib«tnDee  il<«lf.  The  iiiiiscfe,  ihouith  it  bad  h«l  all  its 
tien'oiiaelenieiiU,  still  reiiiaiDH  irritahlo  towani  stimuli  applied  directly  to 
itMlf:  an  additional  pruof  of  the  existance  of  an  independent  inux-'uLar 
irritability. 

For  aonie  tiin«  th«  irrilnhility  or  tho  mtuclo.  n  w«U  toward  utimuli  applied 
directly  Ut  ilnelf  nc  toward  iboM-  upplivtl  ibrousb  tbc  iinpaiird  ncrvu.  •ceni*  to  bo 
ditniiiiabed :  but  after  u  u'liile  a  pvL-uliHr  i-i>iiiliiloa  (to  wliidi  we  bnve  already 
alluded,  {  78)_  oeta  in,  in  wliich  Ihe  muscle  1h  found  to  bo  oot  eaally  Bliinulaie<)  by 
single  induction -shocks  but  to  rtvpond  ritndily  to  tlie  innke  or  break  of  a  eon»lant 
current,  [n  Tact,  it  ia  said  lo  bc<u)mv  nvcn  nxirc  lenntive  to  tlio  Utt«r  mode  of 
utimulation  than  it  vru  when  lis  nerve  vtHa  iuUi<.-t  luid  KiDCtJonally  acUve.  .4t  the 
mme  time  it  also  beconiM  more  irritable  toward  direct  mechanical  dtiniuli.  and 
Tery  frequently  fibrillar  contmciiunH.  more  or  Iom  rhythmic  and  apparenily  of 
Bpnntaneous  origin,  (hougli  thc^ir  cHUsntion  is  ohscure,  moko  their  ap|>earanc«i 
TliiR  plinkc  of  hci);bleiie(l  seiisilivcnvaa  of  u  musde.MpEicially  to  the  constant 
current,  nppenra  to  reach  ii^  maximum  lu  man  ui  about  tbe  seveutb  week  alter 
nervoun  impulses  have  tensed,  owing  to  [lyury  lo  tbe  aervea  or  nerToiu  centre  to 
mich  the  muscle. 

If  the  tnusciv  thus  dcprivoil  of  ila  nervous  elements  bo  left  to  il«elf  iia 
irritability,  however  teetMl,  woner  or  later  diminishes;  but  if  (be  muscle  be 
iwri'idieally  thrown  into  contractions  by  tirtilieinl  stimulation  nilh  the  oou- 
Miuit  current,  the  decline  of  irrilnhility  and  atlendnnl  loss  of  nutritive  power 
inav  be  poel{>oned  for  some  conniderable  time.  But  as  far  as  onr  esperieuce 
goce  at  present  the  arlitieial  atinuilalion  cannot  fully  replace  the  natural  dae, 
and  9u»uer  or  later  Itie  muscle  like  the  nerve  suHere  degeneration,  loeet^  all 
irritability  and  uUimulely  its  place  is  taken  by  connective  tissue. 

§  84.  Tiir  iiijiuenK  of  (r-mpenilurc.  We  have  already  seen  ibai  sudden 
heat  (and  llie  same  might  he  said  of  cold  when  sufhciently  intense),  applied 
1(1  a  limti«<l  )iartof  a  nerve  or  muscle,  as  when  the  nerve  or  muscle  is  touched 
with  H  hut  wire,  will  act  as  a  stimulus.  It  is,  however,  much  more  difficult 
to  generate  nerv<iuK  or  muscular  impnUea  l>y  cxjKNting  a  whule  nerve  or 
tDUscle  tn  a  gradual  rise  <>{  lem[Jiirtiture.  Thus,  according  to  mott  obflerras, 
R  nerve  bolonifiug  to  a  niimcle'  may  be  either  cooled  to  0*  ('.  or  below,  or 
heated  to  W  C.  or  ercn  100°  C,  without  discharging  any  n«rvoui>  impulses, 
u  shown  hy  the  nbeeucc  of  contraction  iu  the  attaclicil  tnuscle.  The  con- 
tractions, niorvorer,  may  be  alMint  even  wlicn  the  heating  ba:<  uot  been  very 
IfTndual. 

A  muscle  may  be  gradually  cooled  to  0°  C.  or  below  without  any  contrac- 
tion bein;;  caused ;  but  when  it  »  heated  lo  a  limit,  which  in  tne  case  of 
fr()|;'s  musules  is  about  4.^^  C..  of  mammalian  muscles  about  50"  C,  a  sud- 
den change  lakes  place :  the  muscle  fulls  at  the  limiting  temperature  into  a 
rigor  mortis,  which  is  initiated  by  a  forcible  contraction  or  at  least  sliortvning. 

<  T1iaBeUon<irnldui<llie*laiiM(uary  utnvirLlltr«<ouiiid(n«(liaRl«Hrp(intotio(ilioir«fk. 


^DKOIiri  or  ItRtTABtLlTY  OT   VTSCLSS  ASV   XERVKS. 


I 


M-xl<raic  w«nntli,  e.  y.,  id  the  fro^-  an  lucmu  of  t«ni|Ji-m[i)ti.-  u[i  (u 
•oOM'wbBt  below  -lo^  C,  ftvufs  bolli  niuscular  and  nervniu  irritnbiliiy.  All 
|(m  molFCiiIar  jtmcoees  are  ti«st«ne<l  nitil  fiidliuitnl :  lli«  oonirni-Uun  it  far 
*  ipveo  ctimulut  greater  aiit)  nvore  rapid,  >.  r..  of  i>hon<T  (|uni(i»n,  mm)  iirr- 
X"m  impillw*  are  geiiented  morv  rauiily  by  »ltglil  »tiriiuli.  Owing  to  tlic 
<|aklcrmitf;  of  the  cbcmical  vhango*.  ibc  viipiilj-  of  new  niiucriiil  may  prnve 
iiaoutlinrnt :  benee  muacl«4  and  ttcrvM  rcmovct  from  tliL*  budy  Wme  thi'ir 
irrilBtnlitr  mun'  ni|>idly  iil  n  hi^h  limn  at  a  low  t<'iii|H'rnlure. 

Thr  );r>(lual  njijilicntuin  of  4'uld  tn  a  lu-rvi',  f»|ic(-iiiUr  wbcii  tW  tcnipera- 
tarv  i*  ihiH  bmuglii  near  t<i  0°  C.,  >tnckcii«  all  lli«  iiiulcnilur  girocfMes,  so 
lltal  (b«  mm  itf  iH'n-iMis  im^iulfo  i»  li-xci-ncil  mid  |iix>Ibn;;eiJ.  llie  vclocilT  of 
ita  patimgr  Inriti};  niucli  >tiniiiiiiibci).  e.  y..  (ntta  'lH  metren  to  1  metre  |)er  MCotuI 
At  abiiui  {)'  C,  ibr  irritubililr  of  th«  ni-rvc  di«appear»  allof^her. 

Wfa<-u  a  mitM'le  u  vx\».v*a  to  similar  fold,  <:  9.,  lu  a  tern)  tern  lure  very 
lilltv  alwiTe  Kcro,  llic  eoiitrni:tiniiR  are  retnorkably  prDlan;;ed  :  iliev  ari; 
(liniiiii'luHl  in  bright  nt  llbc  f^me  timei  bul  not  iu  proporlioii  to  tbe  iiicreaae 
itf  tticir  duration.  ExjkimhI  to  a  temperature  ut'iero  or  b«[ow,  niuM-ltn  aioh 
loHtllHr  irritabiliiy,  wilbotit.  however,  imderKotu^  ri);or  raorlia.  AlW  aii 
cspmirv  of  not  inure  titan  a  few  eei-onda  to  a  lemjienUurt.-  not  nm<-b  below 
ibry  may  be  mtored  by  Kraduiil  wanutb  tu  »u  irriliilik  cotidilion, 
Uxiugb  Ihey  nuiy  npitcar  to  bave  been  frown.  Wlieii  kc]>l  froKvn, 
r,  for  aonie  few  luinuio.  or  when  exputed  for  n  IfM  linir  tu  tcnipcra- 
tara*  nf  apveral  degrees  below  iiero,  ilietr  irritability  is  ]K-riuaneiillv 
itHmytd,  WlM>n  al\«r  tbn  Ihey  arc  thawed  ihey  arc  at  firvt  »uppK-,  am), 
aa  ve  b«v«  aeon,  may  )>e  uituh  to  yiuld  miiM-lu  pliiMiii:  but  th<.'y  ver>- 
ipwdily  enter  into  rig<ir  mortis  of  u  lunM  i>i\inoiincc<]  cbaracl«r. 

1  8&   Tlf  I'nylii/Tiw  0/  biood-wupply.     When  a  uiiaelo  still  within  the  hodv 

b  ityrixtii  by  iiity  nioBD*  of  lt»  proper  blood-«upnly,  m  when  the  hloud- 

vn«M  gotag  to  it  are  ligntiirvd,  tbe  same  i^adual  loea  of  irrilabilily  and 

tul  ■npfliiiii  of  rii-nr  ntiirlw  nre  ohsen'ed  as  in  muscles  ivmoved  froin 

tb  bodr.     Thus  if  iKe  alidoniinal  iiurlu  be  ligntored,  (hu  miieelee  of  the 

kntr  linba  !<««  their  irrilitbilily  and  tinally  become  rigid.     ^k>  also  in  sys- 

Hode  dtatb,  wheD  the  blood  supply  t<:i  the  miiacla  is  cut  off  by  the  oeasBtion 

of  fhe  dmilation,  loss  of  irritabiliiy  eiieuu,  luid  rigor  mortia  evoDtuallv 

r»|hiw*.     In  a  human  corpm  the  nuacla  of  tlie  l>oily  eiiU-r  into  rifpiT  murii!' 

A  m  6xrd  order ;  Brsi,  thoae  of  the  jaw  and  neck,  then  ihusM:  of  the  trunk. 

MTt  %hom  of  tbe  anna,  and  la«tly  those  of  the  legs.    Tbe  rupiiliiy  with 

tUeh  ripH-  motib  ctomes  en  ufter  death  varies  counderahly,  Wxojt  deter- 

■iaad  tiotb  by  exiemal  circumsluicea  and  by  the  iniemul  i.»iii]i[ioa!>  of  the 

Wt.     Tbu*,  exifrnal  warmth  hnMcua  and  cold  retard*  ibe  tmm,*!.     AlVr 

(nat    mtucular  exertion,  ns   in    hnnu^l    auimal*.  and   when  diiitb  clowe^ 

•Mlin^  (li»*«»r»,  riiror  morli^  in  mort  mm.«  cumtv  i>n  rapidly.     \t  a  i;encral 

nit,  ii  ttiuv  Ih-  Miid  that  the  Inter  it  i«  in  making  it;!  appearance  the  more 

ffooouDcrrl  il  i»,  iind  the  longer  it  Instc:  but  there  are  many  exception*. 

ad  wbeit  the  >tiUi*  i»  n>c-ogiiiM-d  a«  boiiig  fundamenially  duo  I0  a  clotting  of 

attain,  it  b  eaar  to  undenlnml  ihnt  the  amount  of  rigidity,  ■'.  f.,  the  amount 

i/tbe  r)ot,  ana  the  rapidity  nf  the  onset.  ■■ «.,  the  uiiiekiiesB  with  nhich 

>t«|palalioa  tak«  place,  may  vary  independently.     The  rapidity  of  odh-I 

i&cr  mutcular  eser^^iK  and  wasting  disease  may,  tierhaps,  be  in  iiarl  dejM'ud- 

won  an  iiH'Teaae  of  acid  reaction,  which  ia  produced  tinder  tnoee  circum- 

*M(a  U)  the  muscle,  for  thia  leema  lo  be  favorttble  to  the  coagulation  uf 

iWatutcIe  plaama.     When  rigor  mortis  has  once  become  ifaorougfaly  ntab- 

b)M  in  a  muscle  through  de|)rivalion  of  blood,  it  cannot  be  removed  by 

uy  tuh*eouetit  supply  of  blood.    Thus,  where  the  abdomiital  aorta  ho* 

itnuinrd  llgaiurtu  until  tlie  lower  limbs  have  beconte  completely  rigid, 


144 


TUE   CONTUACTILH:    TldtJL'KS. 


untying  the  lignliirc  trill  doi  iv^tore  tho  miisolM  to  sn  irritable  coD<liti<ia: 
it  feiiuply  hnshrns  the  ilecom posit iuii  of  the  deud  tiaeues  by  eiipplyiii>;  ihetD 
vilb  uxygQa  mid,  in  the  ituic  i>f  thp  mniDiDitl.  wilh  warmth  aleu.  A  miucle, 
however,  mny  nciiiirt-  us  ti  whole  a  certaio  nmoiiiit  of  rigidity  on  account  wf 
BOiueuf  the  fibres  bpcoiiiing  rigid,  while  the  remainder,  though  (hey  have 
lott  iheir  irritiibilily.  have  not  yet  advancerl  intii  riji-ir  iJiHrtii*,  At  sucli  » 
juncture  ii  renewiil  of  the  bluod-siream  may  leaiore  the  irriluliiliiy  of  iltuM 
lilires  which  were  not  yet  rigid,  and  ihua  appear  to  do  awuy  wilh  rigor 
mnrlia;  yet,  it  appears  that  in  sauh  vanen  Iht-  tiliro  which  havr  a<'tu(illy 
become  ri>rid  never  regain  their  irritability,  but  und^r^o  diiR-neratiiui. 

Mere  liAi  of  irriiahilily,  even  thxiigh  oumjiltrtf,  if  st<>[>pin)(  *horl  Df  the 
Actual  coagulation  of  the  muj^cle  )<iilHitun»>.  may  be  with  care  removed. 
ThuD.  if  ■  Ktrcum  of  bUnvi  he  aent  urtillcially  through  the  vcffcU  of  »  K-pn- 
ratctl  (mtniinulian)  niiiM^le,  the  irrilnbibty  niay  Ih-  imiintftincd  for  a  vcrv 
considomblc  time.  On  Ht<>|)|)ing  the  artilicini  circidntioii,  the  irritability 
dimiiii«hp«  ntid  in  lime  entirely  dinappi^rv;  if,  however,  the  eimm  Ik^  at 
once  resumed,  the  irritability  will  Ih-  recovered.  By  ivgulatiug  the  flow, 
(he  irril«hilily  mny  he  lowered  and  (up  to  a  certain  limit)  ruiicd  at  pkiistirt, 
From  iheeiioeb,  however,  of  inlj'rfcrcnce  with  the  normal  b]o4xi-stivam  thero 
is  a  gradual  dimimiliim  in  the  rcsponaet  to  stimuli,  and  ultimately  the  mus- 
cle KiBes  all  its  irriuibilily  iitid  Mntmea  rigid,  however  well  the  artitiiial 
circiilalion  be  ki^pt  up.  This  fnilure  is  probably  in  great  part  doe  lu  the 
blood  sent  through  the  tissues  not  being  in  a  perfectly  normal  L-undition  ;  but 
we  have  at  present  very  little  information  on  this  point.  Indeed,  with 
re#])ect  to  the  ^tiit/iVy  of  blocxl  thus  emeiitial  to  tlic  maintenance  or  reAtore- 
lion  of  irritability,  our  knowledge  is  definite  with  regard  to  one  factor  onir, 
vii.,  the  oxygen.  If  blood  deprived  of  its  onygen  be  sent  through  a  muscle 
itmoved  from  the  body,  irritability,  so  far  from  being  maintained,  ^eeius 
mther  to  have  it^  diiiappeanmce  baHtened.  In  fact,  il  vem>u#  bloud  cun- 
tinncs  lo  lie  driven  through  u  miuele,  the  irritubilitv  of  the  muscle  is  lost 
even  more  miiidly  than  in  the  entire  abnenct!  of  hlooa.  It  would  seem  that 
venous  blootl  ii*  more  injurious  than  mine  at  all.  If  exbauv^on  b«  not 
carried  loo  far  the  muscle  may,  huwatver,  be  revived  by  a  proper  supply  of 
oxygenated  blood. 

Ine  influence  of  blood-nipply  cnnnot  be  so  satisfactorily  studied  in  the 
oaae  of  neim  aa  in  the  ease  ol  hium^Itv  ;  there  can,  however,  be  little  doubt 
tliot  tlie  effects  nre  analogous. 

§  86.  TItr  iiijtwnrr-  oi Jiinrtinnnl  arliribj.  This,  too,  is  more  easily  studied 
in  (be  case  of  musclcn  than  of  nerves. 

When  a  muscle  within  ihc  body  is  unused,  it  wastes  ;  when  used  it  (within 
ccrtiiin  limiU)  grows.  Both  these  facts  show  that  the  nutrition  of  a  muscle 
is  favorably  aflecled  by  its  functional  activity.  I'art  of  this  may  be  an 
indirect  effect  of  the  increased  blood-supply  which  occurs  when  a  muitele 
contnietA.  When  a  nerve  going  to  a  mitscie  ia  stiiuulalcd,  the  blood vawelii 
nf  the  muscle  dilate.  Hence  at  the  time  of  the  contraction  mort  bhiod 
flows  through  (be  muscle,  and  this  increased  How  continues  for  some  little 
white  ttA«r  the  uuntractioii  of  the  muscle  has  ceased.  But,  apart  from  the 
blood -supply,  it  is  jirobable  that  the  exhaustion  caused  hy  a  ooutraetioii  is 
imnteiliulely  Ibtlowed  by  a  reaction  favorable  to  the  nnlriuon  of  the  muscle; 
and  this  i*  a  roMii,  [Mwihly  the  chief  reason,  why  a  muscle  is  iucre«kM>d  by 
use,  that  is  to  «ay,  the  ItMe  of  sulMtanoe  and  energy  caused  by  the  coiitnic- 
lion  is  subHK|ueiitly  more  than  mode  for  by  ini-rensed  metabolism  during  the 
fallowing  period  of  rest. 

Whether  (here  be  n  third  factor,  whether  mu»:les  for  instance  arc  govcrued 
by  >o-called  trophic  ncrx'ea  which  affect  their  nutrition  directly  in  some  other 


I 


I 


*ay  than  hy  [iiSu«Dcin)[  cither  tli«ir  blood-siippi/  or  tbeir  aetivity,  aiuM  m 
wrai  b*  kn  tiiiilf^-iitol. 

A  aimelc,  «v>-ii  wiiliin  the  body,  after  prolaoK«<l  action  i*  fatigued,  •'.  it., 
A  MrmMr  aiiaiuliM  ix  ivquirerl  to  ptMliice  th«  sami.'  cuiUnitrliuii:  in  other 
woffik.  Ua  Irritabililv  may  Iw  Itiwtiwsl  by  functional  nativity.  Wb(Hh«r 
fuartjuDal  nrtiviiy,  lb<'n-liirr,  i<  iiijiiniHi*  or  biini^fu-iiil  ilci|Hiiibi  on  iCM  amoiiiil 
in  rvlaiifin  to  tb<'  comlilion  q(  ihv  muKck.  It  niiiv  lii;  here  rcmurk^sl  that  tu 
a  ntiacla  bM-otim  more  anil  more  (btigucd,  #lininli  of  «hort  duration,  Mich  as 
leductioD-afaocks.  looner  h«c  th«ir  efficacy  tlian  do  vtimuliofluiigdrdunitioD, 
tucfa  M  ibe  break  and  make  nf  Iht-  c^niitaiit  curn-nt. 

IImi  wnee  of  &tig»«  of  irhich,  aRer  iirolonged  or  unLieaal  exortjon,  we  arc 
nMMemiu  in  our  own  b<idi«a,  ii  prcibably  of  complex  orieiti.  and  its  Dalure, 
hikm  ihmt  of  the  nonnnl  luuBculnr  ecitw  of  which  we  sliall  bave  to  speak 
hsvaAcr,  ia  al  preaenl  ool  thoroiiffhly  umkralood.  It  seems  to  be  ia  the  firM 
|d«ce  tbe  mult  uf  chaiigi^s  in  the  iDUseles  thoiDBclrGe.  hut  ia  poauhly  abo 
ewmd  bjr  changes  in  the  nerroua  apparatus  conwrDi?<l  iu  muat-ular  nclioo, 
aad  ntMctally  in  thoae  parta  of  tbe  central  n«r\'ou(i  •j'sleni  which  are  cod- 
oncxl  ia  the  productiou  uf  voluntary  iiupulaea.  [n  any  oaae  it  cannot  be 
ukrn  na  an  ailoiuiite  mciuure  of  tbe  actual  futisue  of  the  muaclea ;  for  a 
■an  who  -■•y*  he  i!i  iibaolutely  cshauMed  niuy,  iitiJi-r  ext-iicm«[it,  pcrforni  a 
my  luge  amiiuni  of  work  uilh  hit  already  weary  uiuKtilcM.  The  vtill,  in 
hcU  niralv  if  cvi^r  calln  fnitb  the  grcaUH  conlractiiiuii  of  whivh  the  niuccl« 
■n  eapabfe. 

Awolul*  (tcntpornry)  cxbauttion  of  the  mii»clo#,  to  that  the  strongeat 
■thauli  product  no  coiilracitun,  may  be  producnl  even  within  the  body  by 
uMtiaS  *iitniilaii<Hi :  nwxvry  lakm  p)ac«  on  rmU  Out  of  the  body  abwluU) 
tshttuKion  lakca  plan'  n-udily.  Hen.',  alcr,  itvovery  may  take  place, 
Vbalber  in  any  given  aa»e  it  does  occur  or  nut.  ia  determiDed  by  the  aiumtot 
•d  eoBinictMin  atuing  the  exhaustion,  and  by  the  previous  cnudilion  of  tbe 
Made.  In  all  cases  recorery  it  basleool  by  renewal  {natural  or  artificial) 
«f  iha  bliHid-Alreain. 

Tbt  BKtR  rapidly  ihe  eootractiaQS  follow  eat-h  other,  tltc  lew  the  iiilorval 
bitncn  any  two  contractions,  the  more  raiiid  the  exbauwiou.  A  certain 
nabar  of  ainuli*  inductioD-^ooks  rcpeateJ  rniiidly,  say  cverr  second  or 
<Aanr,  bring  about  •'simuMire  Iom  of  irHlabiliiy  more  rapidly  than  the 
«as  anmbw  of  aboclu  repealed  1i>m  rapidly,  fur  liiNtanw  ewry  5  or  10 
wails,     RcBM  l«tanui  ■•  a  ready  mean.t  uf  pr>iihji'itig  t^'x hiiuslion. 

!•  axfaaiiMn)  mu»cl4!«  the  I'hutticicy  in  much  diniinislit-d :  the  tired  muscle 
Miras  Um  n-ndily  to  Itn  imiurnl  U-uglh  ihnn  doc*  tli<-  I'mit  one. 

The  pxhauslitxi  du«  t»  cunt nu-lt<m  may  be  ihi'  result  either— of  tbe  con- 
■isMiitn  of  thr  More  nf  ready  ountrartilc  material  prcwnt  <o  tbe  muscle; 
<4Hi  tbr  Bccnmulatiun  iu  tbe  tiMiicof  the  proclucUof  ibeact  of  oontraciJoD; 
«i  «f  both  i)f  these  iwuet. 

TW  rfMomtive  influence  of  rest,  in  the  caw  of  a  miisclo  removed  from  tbe 
limitation,  may  bt-  explained  by  supposing  that  during  the  repoee.  eitlier 
tti  Bieraal  chan^ea  of  the  tissue  manufHcturc  new  exp!i)t>ivc  matenal  out  of 
Asopaiparalively  raw  material  already  pr«scni  in  the  tibres,  or  the  directly 
hnfiil  pnnluols  of  the  act  uf  coniracliuu  undergo  changes  hv  which  they 
u»  nMircrted  into  comjiAratively  inert  bmlies.  A  stream  of  fro>h  blood 
«7  rxcft  its  reef>rative  inllueooe  not  only  by  quickening  tbe  above  two 
mat*,  bui  aim  by  oarryint:  nfT  the  immediate  waaie  products  while  at  the 
«M«  linM  II  briitn  now  raw  material,  li  in  not  known  to  what  extent  each 
•tthesa  part*  i*  tOaynl.  Thai  iIh-  proilitcta  of  contraction  are  exhauatiuK  in 
tUroKcts,  U  sliown  by  the  imiu  that  the  iiiJM?ti<in  of  a  a<dution  <>(  the 
aatdMXtraclivea  into  tbe  vcwvls  of  a  muscle  produce*  exhaustion,  and  that 

10 


THK  CONTRACTILS  TlSgtTBS. 

vxhaiisied  inuBcl«*  are  iwovfrwl  br  the  simple  injection  of  inert  snline 
foluttoue  iiitn  tUuir  bloo<lve«ols.  But  tb«  matter  hw  Doi  ytl  been  fullr 
worked  out. 

One  iiuix)rtnnt  clement  brought  by  freab  blood  b  oi^emi.  This,  u  we 
have  seen,  i»  mil  ncc?<«Niry  for  llie  tarrying  iml  f,{  Uie  acturiTcAnmction,  awj 
tct  n  et^e'iitinl  to  tb«  maintciiaiice  of  irritiibility.  Tito  nxTgvn  absorbed 
tnr  Che  mitn'k-  npjiiireDtly  ent«n  in  tome  itet-uliurwuy  into  tlie  fornmtiou  uf 
tnat  oomplvx  irxploaivo  niaterinl  the  de<^uiii[iiuiti(in'<>r  which  in  the  act  of 
oontiaotioii.  th<iiiph  it  jjives  rise  to  caHxinic  acid  iind  uthur  piwduou  of 
osidndoD,  u  Dot  in  ilwlf  a  pmcees  nf  direct  oxidation. 

Thi:  KxEBiiY  OP  Mt.>ot.i:  ami  Kkhvk.  and  the  Natuhe  or 
MlW-ULAR  AND  N'ERrotm  AcriuK. 

§  82.  We  may  briefly  revapitulaie  »ori«  of  tho  chief  results  arrived  at  iii 
thfi  preoi'iling  pngeii  im  followii : 

A  inimciilur  iimlraotinn  ibH-tl'  is  MMiitially  a  tnu»loeation  of  moleoulm.  n 
change  of  Ibrm,  not  of  bulk.  We  cannot  my.  however,  nnyibintc  defliiiir  &• 
to  tlie  nature  of  thi«  triin«l(>cjition  or  lu  to  tlio  way  in  nbich  it  h  bnmehi 
about.  For  in»tiinec>vc  cannot  stiti«riii-Ioriiyexplnin  the  eoDiieetinii  U-ttiivD 
the  Htnation  of  n  miisc-ular  fibre  niid  u  mtiiteiilur  contTttetiou.  Xritrlr  all 
rapidly  contracting  musclee  lire  strinled.  itnd  we  must  aupixve  tlint  the 
BtriaCion  m  of  Bonie  use ;  but  it  is  not  eweiiliHl  to  the  carrying  out  of  a  eou- 
trnttion.  for.  as  we  shall  see,  the  cunlraclion  of  a  nun-Atrinled  mtiacle  is 
fumUiineutally  the  Manu'  ti»  that  of  a  tiiriated  iiiti«;le.  Hut  whatever  be  the 
exact  nny  in  ivhioh  the  tiant^ioeation  a  ejected,  it  U  in  w^me  way  or  other 
the  result  of  n  chemical  cliango,  (if  an  cxplnMv*!  deconijKNiition  of  cenain 
part«  of  the  t]iii>ck-  KiilMlancc.  Tho  vni'rg>'  which  is  expended  in  the 
niechaDiral  work  done  by  the  muscle  hiu<  Itx  Knurce  in  the  eoerf-y  latent  in 
the  muscle  substance  and  set  free  by  thai  cxplonioii.  Concemiiif;  the  tuHiire 
of  that  explosion  we  only  know  nl  preecnt  that  it  rmulis  in  the  producli'jn 
of  earbonie  scid  mid  in  an  increase  of  ihc  acid  rcai'tinn,  and  lliai  beat  ii>  set 
fVee.afi  well  as  the  specitic  muscular  energy.  There  la  s  general  pnnillelism 
belwceu  the  extent  of  metabotiani  uihiug  pisce  and  the  amouul  ot  eDer;gy  act 
free;  the  greater  the  development  of  carbonic  acid,  the  lai^r  b  tliccan- 
Iraction  and  the  higher  tlie  temperature. 

It  i»  important  to  remcnitier  thal.iui  we  have  already  uived,  relnxalioo,  the 
return  to  llie  orfgiual  k-nglli,  i.n  an  ciiAeutial  |>ari  ol' the  wnole  cuntrn'tion  no 
Ins  thnn  ihe  yhdripiiing  itjtelf.  It  Ik  true  that  llie  return  to  thv  original 
Uinglb  i]>  H»»i9ti.-d  by  lh<- afri'lohiiig  exerli-d  bv  the  load,  and  in  the  cww  nf 
aiUBclcs  within  the  living  budy  **  nci'iired  1>y  the  action  of  aiitOgoniMie 
muscles  or  b^'  vnrioux  nnatomical  relalidUH ;  but  the  fact  that  the  cotDptete* 
ncMand  rapidity  uf  the  return  arc  ilopciident  on  tlie  cmiditian  of  the  muscle, 
that  is,  on  tne  complex  chuigt^  within  the  nnucle  making  up  wbit  we  call 
its  nutrition,  the  tired  muscle  retuxiug  much  more  slowly  than  the  untireil 
muscle,  shows  that  the  rnl&xntion  is  due  in  Ihc  niaiu  tii  intrinsic  proceMU 
going  on  in  ihe  muscle  itself,  proccsecs  which  n'e  might  chnmcteriie  aa  the 
reverse  of  lh«e  of  contraction.  lu  fact,  to  )>ut  the  matter  Ibrcibly.  adopting 
the  it  lustration  used  in  g57,  and  regarding  rclaxnliomutt  change  of  molecult* 
(Vwm  a  "  formatidU  "  uf  one  hundred  in  two  lines  of  fifty  each  lo  a  formation 
of  t«n  columns  each  ten  deep,  it  would  be  possible  lo  sup|>ort  the  tbesit  that 
the  rrally  active  foreo  in  muscle  arc  those  striving  to  maintain  the  latter 
formation  in  columns,  and  thai  the  falling  into  iloubtc  lines,  that  ts  to  aav 
the  pontraetion,  is  Ihe  mult  of  these  forces  ceasing  to  act ;  in  other  wortf$ 


J 


TUB  BNKHOr  OP  III^CI.K  AND  XERVE. 


14; 


Umi  iIm  mMiinuMd  atotc  of  tlw  miiftcvlnr  fibn>  U  what  iokv  hccnilod  Um 
wUural  lUte,  tli«t  ihc  rclaxcl  t-otulitUiti  i*  ntily  hrou^'hl  a\x>in  »I  tbn  cxpctiw 
of  ckaogM  cnuHlcratrtiii);  lite  nnliirni  [ondt'iicice  of  l}ic  tiltro.  Wilhout  gofn^ 
■D  Ihr  M  tliis,  bowi-ver,  we  may  still  rpco||;niz«  th&l  iwth  cuiilnwtion  nnd 
nlazsUMi  era  the  rmilt  uf  chnn^n  which,  niiof  ihcy  sccin  to  be  of  a  cheitiicnl 
BHun  in  ibc  iiiiv  <.'iu«,  nrr  pmlMibly  «o  it)  the  other  aJau.     A>i<l  thoUf;h  in  the 

iafai^Ma  nf  exact  knowk<d);e  il  in  (laiigerotis  to  speculnte,  ne  way  iiuncioe 
thai  ihtOT  chemical  events  leiuliog  to  relaxation  or  elongation  w  of  an 
ofio^U  ttt  BOtafonUtic  cluinii-ter  li>  ihoae  whoee  issue  ia  coDtractiou. 
It  luH  not  boen  possible  hitherto  to  draw  up  a  complete  equalioa  between 
iW  lalcBt  enericy  of  the  nislerial  and  the  two  fbrnis  of  actual  enei^  set 
frw.  bwU  anil  luovenM^uU  I1ie  pro^wrtioa  of  enerji^y  Kiveu  out  aa  lieat  to 
that  taking  on  tJi«  form  of  work  varies  under  different  circuniiitauc«a :  and 
it  w<wM  Bppou-  tliiit  iiu  ihe  whole  a  niuM^lc  wuuld  nut  be  much  more  i;lBoieiit 
tkaa  a  ttcam-eugiue  in  nwgiecl  to  the  ronvenUm  of  rhcmical  uctiuu  into 
BM^aaiod  work,  were  it  not  that  in  wann-hlocidetl  aniiutilH  tlie  liMt  );iven 
«nt  b  Dot,  ai  in  tli«  8teaiu-eui;iii«.  in«rc  Iom,  hut  by  k>'i>pii)g  iiji  tht-  Miimal 
KapcmoK  nrrea  tnanj  auhttiiliarr  purpuM*.  It  might  Ix'  iiup|>tNH.Hl  that  ill 
aoMUfVcUoD  by  whidi  work  a  actually  doi»,  as  RomptrttI  with  the  Mow 
oaMtaetfcHi  wh«n  uo  work  i*  doue.  ibm  >«  a  diminuiion  of  the  increuM  of 
tuipmturr  (-urr«w|ii>ndlng  to  tli«  timouDl  of  work  d<>n<'.  that  i»  to  »y.  that 
Ik*  BWchonit-al  work  i*  ili<ne  at  lb*- vxpcnM  of  energy  which  olherwis)- would 
ft  D«it  a*  boat.  ProWhk-  as  this  nuiy  ttvn,  it  has  nut  yot  been  expvri- 
SMMaJly  verilWd. 

Of  lh«  exact  Datiin*  of  the  chemical  chan^-^  which  underlie  a  mutcular 
naUactkui  we  know  viyry  little,  the  must  importaol  fact  bein^;.  thai  the  ooii- 
indjoa  m  not  th«  outcome  of  a  dirccl  oxidation,  hut  the  splitting  up  or 
tzplaitve  d«ooinpontioi)  of  some  complex  suiiMaiice  or  Auhttaocea.  The 
■Mil*  dott  ooDHine  oxyi^n,  and  the  pmducttt  of  muscular  awtabolism  are 
btW  nd  prodncU  of  oxidation,  but  the  oxy){i>M  ap|>eara  to  be  introduced 
Kt  It  tiie  niutnent  of  expl<itii<iu  but  ai  some  earlier  date.  As  to  the  leal 
•Mm  of  th»  exploBire  material  ne  are  as  vet  in  the  dark :  we  An  uui  know 
It  (ertain  whellier  we  ought  to  R-fcui^l  it  bh  a  sin^cli;  suWtaiice  '  in  the 
ctmieal  tenae)  or  as  a  mixture  of  more  «ub*(Aiic»  than  one.  We  may, 
tnvvtr.  pvrbapi  be  allowed  pruvitionally  to  speak  of  it  at  all  event*  a*  a 
ai|tk  Mbataooe  and  to  call  it  "  cxmlraciile  aiaterial,"  or  we  may  ndo|>t  a 
Mm  vUeh  hat  lieen  suggettei)  and  aill  it  inayn. 

W«  iImII  hare  ooowon  to  i>i>int  out  taler  on.  that  the  hving  stitwtance  of 
ante  nil*  it  abb  lo  aiaoutactiire  and  lo  lodi^  in  the  tubetaiice  of  the  ocU 
aWtaly  eooakiarabk  qiiaiitilicii  at  lat  whcichy  the  cell  becomn  a  fat  cell. 
ibhl  ao  Jbrmed  and  lo<)gcd  being  sub«c<(uently  by  some  means  or  other 
fcthafgnl  from  tliecell.  Wo  shall  also  have  occasion  to  point  out  that  in  a 
■—■hit  siuilar  way  the  living  material  of  certain  gland  cells  nuiuulactum 
■■I  1m)(M  id  itacif  ourtain  nubetanece  which,  when  the  cell  "secr«t«»," 
taimfi  man  or  leas  change  and  are  ejected  frum  the  cell.  Theae  suhataocea 
Mar  to  be  produolaof  the  activity  of  llie  living  subataoce  of  the  cell,  and 
tobf  *o  telatod  to  that  living  substance  that,  though  discontinuous  with  it 
oi  urrrly  lodged  in  it  they  are  still  capable  of  beiug  mi  iuHuenccd  by  it  as 
h  aaikiyo  change  more  or  teea  aud<Wii.  more  or  luu  profound.  And  we 
^,ttao^oo  theaaalof^of  thenfiucelhiaud  gland  cells.auppnee  that  the 
hncnbaUuee  of  the  muade  roanufacturca  and  ludgtu  iu  itself  this  con- 
taw*  taaMrlal  or  inggen  which  ia  capoblo  of  lK<ing  »»  iidluenoed  by  the 
liiiiy  aubMaDco  aj  to  ui>dergo  an  «xp»(«ive  decomiNMittou.  But  we  here 
•Mwltli  a  difficulty. 
■  he  tniMcular  tlhre  aa  a  whole  in  emineotly  a  niiro^cenouit  proteid  body : 


148 


THB  CONTBACTILB  TISSUES. 


th«  rniiiiculiir  fibres  of  tfiv  hoily  riirni  tlio  greater  [lurL  uf  the  wliolc  pmicid 
BUUK  of  the  body.  MiinHiv«r  ihi;  onltnnrj  ooiitiiiutMl  mcUboliMa  of  tb« 
roiiKulnr  fibrv  m  ■  whole  is  «»i-nimllv  ii  uilrogciiotts  meubolisiD :  m  wv 
Bbflll  baveto  point  out  luter  on,  th«  muscles  uiidoubiodljsupplyagrent  i>art 
of  that  Urge  oitrogenous  waste  which  appears  in  the  urine  as  iin^:  th« 
nitm);eiioug  metaboliitm  of  the  muscle  during  the  twenty-four  hour«  must 
lherffi.>ri?  be  con^idernble,  and  under  ceriflin  circumetaii(;ea,  as  for  inMUDce 
during  fever,  this  nitroceiiouB  metsboligm  may  be  still  fbrther  larftely 
iiici-ciified. 

On  the  other  band,  as  we  have  already  nhf>wn,  there  can  tte  no  doubt  lliat 
the  act  of  L-outraciiou,  the  explosive  decouipoaitiun  of  the  tiio)^ii.  iloe*  not 
in«reaBe  the  nitro^uous  metabolism  of  the  muscle.  8hall  we  oonclude  ihcn 
thai  the  inogeti  ih  ofiseutially  a  noo-nitroftenouB  body  lod^l  in  the  nitn>' 
nQouf  miiaJle  ^ubniaucey  Not  ouly  have  we  no  positive  evidi^icc  uf  thb, 
out  the  mmlugy  lietween  tontraelion  ami  ri|{or  mortis  is  directly  »p[>o>eil  to 
lucl)  a  vi«iv  ;  for  it  U  aliu<>«t  impimtble  to  mist  the  voncluiiiou  tluil  thv  >tu6r 
which  givcjt  riiw  to  the  niyiwin  I'lot,  thu  carbonic  acid,  and  lactic  acid  or 
Ptlier  Bcid- producing  viibntaHOM  of  ri^or  mortis,  iii  the  same  vliilT  which 
giTC*  rise  to  thi-  trarbonic  acid  and  Int-tic  acid  or  otlicr  add- producing  sub- 
stances of  n  contraction.  The  dittcrynco  Imwwn  the  two  sc«ms  to  bo  that  in 
tli«  conlractioii  the  nitrogenous  product  of  the  decomposition  of  the  inojgMi 
does  not  ap|)car  as  mlid  myosin,  hut  anumes  the  form  of  some  soluble 
proteid.  The  imimrtant  fact  conceniing  the  two  aclx.  Hgor  mortis  and  con- 
traction, is  that,  whilti  the  gn-at  non- nitrogenous  proiluct  of  the  dccon  posit  ion 
of  the  inogen,  m.  carbonic  acid,  is  simple  waste  matter  containing  no  energy, 
fit  only  to  be  cast  out  of  the  l>ody  nt  once  fand  the  same  is  nearly  true  of  th* 
other  non-nitrogenous  product,  lai'tic  acid ).  the  nitrogenous  produet  being  a 
proteid  is  '.till  a  body  containing  much  onei^iy.  whioh  in  the  cu»e  of  tin*  living 
muKcle  may  aAcr  the  contraction  lie  utilized  by  the  mu^dc  itmdf  or,  being 
carried  awav  into  the  blood -stream,  bv  ff>me  other  [larta  of  the  body. 

But  if  ihU  view  be  correct  the  ordinary  melaboli.->ni  gning  on  while  ih« 
muscle  in  al  re&t  must  diflbr  in  kind  an  well  aa.  and  |X'rha|i»  more  thiin.  in 
degree  fn>m  the  nietftlwIiHin  of  contraction  ;  for  thn  furiner,  a*  wt  have  just 
nid,  is  (vM-ntially  a  nitrogenous  luetabolisju  largely  contributing  to  tlw  niiro 
genoiis  waste  of  the  bo(iy  at  large. 

Whether  in  the  muscle  at  n-wt  this  nitrogenous  mctalxdism  it  confined  to 
that  part  of  the  inuncle  in  which  the  iimgen  in  lodged  and  docs  not  involve 
tlio  inogcn  itself.  »t  whether  the  iiio]^n  an  well  as  the  n»l  of  the  fibre  (inder 
goes  metahotism  when  the  mnnclc  is  at  rest,  going  olf  in  puflv,  ao  to  apeak, 
instead  of  in  a  largo  explosion,  its  nitrogcnouo  factore  being  at  tliesame  time 
involved  in  the  change,  are  •[ueetions  u.*liich  we  cannot  at  prcoent  settle. 

$  88.  While  in  muscle  the  chemical  events  are  so  pmminent  thai  we 
cannot  help  coneidoring  a  muscular  contraction  lo  be  ctwcntially  a  rbemical 
nroceas,  with  electrical  changes  as  attendant  phenomena  only,  the  ease  in  dif- 
HKtit  witli  nerves.  Here  the  electrical  phenomena  completely  overabadow 
the  chemical.  Our  knowledge  of  the  chemistry  of  nerves  is  at  preeent  of  the 
tcaiilieat,  and  the  little  we  know  as  to  the  eheudcal  chaii]t;es  of  nervous  sub- 
•tanoe  b  gitini-il  bv  the  study  of  the  central  nervous  or^ns  rather  lliau  of 
the  nerve*.  We  iioil  that  the  JrHlahility  of  the  former  is  closely  dependeni 
on  an  atlurpiate  lupply  uf  oxygen,  and  we  may  infer  from  thin  that  in  nervoua 
as  in  musciilamubataiiceauibtabolinm.orin  the  main  an  oicidalive  character, 
b  tlw  real  cause  of  the  development  of  L'nergy  ;  and  the  axi^-cylinder,  which 
as  we  have  seen  is  matt  probably  the  active  element  uf  a  nerve-fibn.',  na* 
donblcdly  resembles  in  many  of  iu  eheniiual  featurc:>  the  substance  of  a 
muscular  Rbre.     But  we  Imvc  as  yet  no  satiifactory  experimental  cvidctncc 


OS   AOUK   OTHKB    rOKMfl   OF  COXTHACTILE  TISStTB.      149 

the  pMMf^  of  •  nervous  inipul»e  aIoiik  a  oerve  b  th«  rwull,  like  iht 
eootncckn  of  a  maBculBrfibre.orcl>einicalcJmDgt«,aii<l  like  it  ncooinpuikd 
bjr  aa  crolntioD  of  beaL  On  the  other  hand,  the  electric  pbenonieiui  arc  no 
pVDiniiM-nt  that  Aonie  have  bceu  ieiii|iie<l  to  reftHnl  u  iiervuiiii  impiilxo  lu 
■aaninllv  an  Hwtrical  chaugo.  But  it  ihukI  be  reniomhertyl  i)inl  tbi.-  uotiml 
•oamr  IM  ft«e  in  a  utm'uua  iinpiilao  if,  wi  to  njiciik,  inHigDificuDt,  no  tlmt 
chllWiul  fihaaita  ttiu  iiliichl  to  be  n-oignixc)!  b_v  tn<?  incnriM  at  pitaoot  at  our 
di^jMil  MtniM  limply  Muflire  to  pmvitle  all  (he  i-iH-rgv  net  Im*.  On  thv  otlivr 
imiui.  the  rnlc  of'  Imiutniiwion  of  a  nervouo  impiilHi,  puttine  aeidp  other 
telBraa,  M  aJoot  aufllcim  to  prorc  that  it  is  nomelhiiiK  quite  djflercmt  from 
M  onliiMTT  electric  cum?«t. 

Tbr  ininiiu*  ilt*po«iliun  of  ihu  cml-platoi,  an<l  their  rcmnrkable  annlogr 
with  the  elvctric  organ*  which  arc  foiiDd  in  certain  animalB,  haa  suggc^tM 
th*  new  that  Ihr  jNUMige  »t'  a  nvr^-oui  impulse  from  the  nerve  fibre  iDto  the 
nuuvalar  mbitanoo  ie  •>('  the  nature  of  an  electric  (lisebarge.  But  ibeM 
■Mttra  are  too  difficult  and  too  abetrufie  to  bo  discuawd  here. 

tt  nay,  however.  )>«  worlh  nhilo  to  remind  th«  render  thiit  in  every  cod- 
tnrtioDof  a  luurcuiar  libro.  the  actual  change  of  lurm  U  preccdeil  by  invisible 
tlaagn  pruiaigat«cl  all  over  the  libro  and  occupyin)*  the  laleiil  j>eriod.  aod 
llal  tbci*  fBangea  reaenibie  in  their  fcaturee  the  nervous  iiupuUe  of  whiob 
tbrr  are.  fo  lo  fpeak.  ihe  eoutinualion  rntlier  than  the  coniraetion  of  which 
t^y  nn*  the  forerunu«rB  and  lo  which  they  give  rise.  So  that  a  muacle.evei) 
fMuiif  aaid«  the  risible  i«miinatious  of  Ihe  nerve,  b  AiudsmeDtaliy  a 
■Mill  sad  a  ncm  bMidaa. 


Oa  SoHB  OriiER  Forms  or  Coktractilk  Tib»vr. 

Jlain,  Smcolh  or  UnttriaUil  Mtumtar  Tunie. 

t  W.  This,  in  vertebrates  at  nil  ovcnt«,  rar«Iy  occurs  in  isolated  maoseaor 
aaRba,  aa  dam  striated  muscular  tiwue,  but  is  usnally  found  laking  pari  In 
litMniolure  of  complex  orifabs.  such  for  iiietanee  as  the  intestines ;  hence 
tW inveMi|[atii>n  of  its  properties  i^  beset  with  cuaiiy  diflicukiea. 

It  ii  mually  arranged  in  sbeels,  composed  of  flattened  bundlca  or  bauda 
h«ad  InKBtlwr  by  connective  liiHue  earrying  hloodvea^eU,  lympbatiua,  and 
tmn.  SDiDe  of  these  buudles  or  baD<ls  may  be  split  up  into  ^inallor  batid* 
aailarlr  untied  to  each  other  by  o'ninective  listiue,  but  in  inaiiv  cnM«  thu 
•Ua  ^oet  being  ibiu  is  made  ui>  directly  nl'  small  bauds,  h^ach  tniall 
imi  is  oompowii  of  a  ouniber  of  elenieiiiary  fibre*  nr  tilire  i-elU,  nhidi  in  a 
nnaiti  aetiac  ar«  analofroui  to  the  atrial^  elementary  iibr(r:<,  hut  in  many 
Mieetf  diOer  uldcly  fmrn  tbein. 

Eadi  uiWrtaleil  tlinneDturv  fibre  is  a  luiuute  i>bject,  from  60  „  to  '200  ^  in 
impk  and  fmru  A  ^  to  10  /•  tn  breadth  :  it  is  therrforci.  iti  «iz«.  of  a  wlmlly 
wnmt  nnler  froB)  a  Ktriatod  fibre.  [Fig-  4.S.I  It  is  futiform  or  epindle- 
^pr<l,  •otnvwhal  fiatli-iKil  in  the  mi<ldTr  ami  tapering  to  a  jxiint  at  the 
Md*.  ahich  In  vume  <■■■««>  are  branclivd;  but  the  exact  form  of  the  (ibrc 
aiii  (UHor  according  as  the  muscle  is  in  a  Mate  of  oootraction  or  relusation. 
Hidirny  between  tbo  two  cndo  and  in  the  centre  of  the  fusiform  body  lies 
■  uelaiu.  which  in  a  numml  randition  is  elliptical  in  outline,  with  its  long 
■SB  Inni;  lengthwiie.  but  which  under  the  influenoe  of  reogeala  ia  vary 
^^  Uttobeeowe  rod-shaped ;  hence  in  prepared  specimens  the  pnseooe  of  Iheae 
b  Mifcaped  nuclei  u  very  cbaracteTctttic  of  plain  mu^ular  tiauie. 
H  1W  Buoleus  baa  the  ordinary  characters  of  a  nucleus,  and  rery  fre- 
H   fMMly  two  nucleoli  are  coospicuouo.     Around  the  nuoleui  b  gather«<l  a 


TKB  eo;fTBACTII.B  TIflSOtS. 


1K10.O. 


/U 


UuMiK  Akirhw:  I.  fn>m  ihv 

pupQIMl  arlorr  ;  <t.Bllhniit ;  b. 
wllti  Rcollc  Mid.  i;frani  *  loanch 
or  thvaalvrinMIbUl ;  a,  iiucJoi  of 
(be  Bbni  (mwdUlwl  SM  llniei  I,  | 


nmll  '(onutiiy  of  grnnulnr  jirotuplajiin,  like  tlmt  around  the  niiolei  of  k 
Uintetl  fibre,  and  this  u  C(>(iliiiut.-il  alori>:  the  uxU  of  the  fibre  for  somo 
(Ibtlimce  from  vticb  jHtle  of  the  nucleufl,  gnid- 
tinlly  (n]>«riiig  uwav.  and  so  formint;  a  Blender 
grniiiilnr  crn-v  in  the  median  portioD  of  the  fibre. 

Th<-  n»i  iif  tb«  fibre,  fi>nnin)(  its  chief  iNirt,  is 
cumjiuMd  uf  II  tnuiHiiurcnl  but  sonteulinl  refrucrlive 
RuWtitnoe,  whieh  i:<  either  homo^ciicouiiurexhibiia 
n  delicate  loiigttiidionl  libnllutinn ;  tliiit  i»  tiit 
muRclo  •uljBtnntc  of  the  fibre  nml  <;orni«fK>n>li>  lo 
ttiG  ti>u«cl«  eiitwtnncc  of  lh«  9triiili.>d  librv,  btit  U 
not  striateil.  Sometimct  the  whole  fibre  it  tbrofrn 
into  n  »erice  of  tr«ni»vprw  wrinklw,  wbicb  give 
it  a  eirinted  appcnrnnco,  but  this  in  n  very  dif- 
ferent Btrinlion  from  thiit  producml  bj  an  alterna- 
tion of  dim  anil  bright  bandi.  No  »m'h  allerna- 
doD  of  ban<l»  if  lo  be  feen  in  tho  plain  miiBciilnr 
fibre;  the  whole  of  the  eubelance  of  the  fibre 
around  the  nucleus  and  cure  is  homntfeneoua.  or 
at  leaat  exbibiis  no  diflereutialion  beyond  that 
into  fibrillie  and  intertlbrillar  xubstance,  and  even 
this  distinction  ia  doubtful. 

The  fibre  has  a  sharfi  clear  outline  but  is  not 
limited  by  any  diiitinct  sheath  comeapondiug  to 
the  sarcolemma,  at  least  according  to  mo«t  ob- 
ftervurs. 
It  ia  obrioue  that  the  plain  muscular  Bbre  i»  a  nucleated  cell,  the  oell  oub- 
stance  of  which  has  become  diRcreDtialed  into  contractile  sub«tauce.  the  cell 
otherwise  being  but  slightly  changed :  whcrNU  the  niiich  larger  slrialcl  fibre 
is  either  a  nutnlier  »t'  cclU  fu>-ed  together  or  a  ucll  which  has  undergone 
multiplication  in  i>o  far  thai  its  nucleus  hn»  given  rise  to  several  nuclei,  but 
in  trhich  no  diri»ion  of  cell  »ul»lance  has  taken  place. 

A  number  of  such  fuHifonn  nucWied  cells  or  libree  or  fibre  cells  are 
united  logellicr,  not  by  connective  tissue  but  by  a  |>eculiar  proleid  cement 
aabnaooe  into  a  tial  band  or  bundle,  the  laperinj;  end  uf  one  Bbre  dovetail- 
ing in  between  the  bodies  of  otiier  Hbre^.  8u  lun|{  as  this  cement  eubsuinee 
is  intact  it  ia  very  ditiiculi  tu  i^nlate  an  individual  fibre,  but  various  reagents 
will  dttoolve  or  la^iwn  ihi.H  ceiueni.  and  then  the  fibres  se|}arate. 

Small  flat  bandA  tliu«  formeil  of  fibres  oeoiented  together  are  variously 
amneed  by  mciiiia  of  cunnective  tissue,  sometimes  into  a  plexus,  sometimes 
into  thicker  birgt-r  bands,  which  in  turn  may  be  bound  uji.  as  we  have  luiid. 
into  shccl»  of  varying  thicknoM. 

In  the  pIfxuB,  of  cnunn',  the  lumda  run  in  various  directions,  but  in  tlic 
Rhe«ls  or  meinbruiio'  they  follow  i<>r  l)ii>  most  part  the  sntiie  direction,  and  n 
thin  tninsvciw  section  of  a  winwwhnt  thick  sheet  presents  a  number  of 
smaller  or  larger  areas,  oorrt«ponding  to  the  smaller  or  larger  bands  which 
are  e»it  acroe«.  The  limits  ol  each  arcii  arc  more  or  less  clearly  drlim-fl  by 
the  connectire  liseiic  in  which  bluodvcsietB  may  bo  seen,  the  nrcji  itself  being 
mnpoeei)  of  a  number  of  oval  iuiltiii»i,  the  soctionis  of  l.hc  flattened  indi- 
vidoftl  fibree;  in  hardened  specimens  the  outlines  may  from  mutual  pmaure 
appear  polygonal.  In  the  centre  of  some  of  these  sections  of  fibres  the 
nucleus  may  be  seen,  but  it  will,  of  course,  he  abseut  from  those  fibres  in 
which  the  plane  of  section  has  passed  eitlier  above  or  below  the  nucleus. 
When  a  tliin  sheet  of  plain  muscle  is  spread  out  or  leased  oui  under  the 
mierovrope,  the  baiKls  may  also  be  recoguixed.  and  at  the  torn  ends  of  some 


ox    SOUK   OTHER    FORU3   OF   CONTKAOTILK    TIASUU.      1A1 


I 


of  Ifcc  Iwncb  tlie  imlivUlual  fibrec  nur  Iw  >ceu  prujcctiag  nder  the  fashion  of 

BloodnMeh  mud  lymphuioi  are  nrriwi  by  lh«  conDoctive  tinuc,  uid  form 
owitUry  networks  and  Ivmtihatic  pWxu»n>  round  (h«  ainiillvr  bands. 

1  M.  Thtt  anaiig«aM-(if  <■/  llw  norvm  it)  unmriatcd  muscle  difRtra  from  ihat 

in  (tfiaivd  muncJe.     WhcnMic  in  Mrinlci)  miudc  mcdiillated  tibree  ooiuin); 

dina  tnta  tltv  anterior  mnUi  nf  #{)4nai  nerves  iiredominale.  in  plain  muitcle 

OW  ■xdllUaUd  fibrv«  urc  iD<wt  abuodnul ;  in  fact  the  nervw  gaiDg  to  plain 

OismIm  Mv  not  only  smnll   but  are  nlinoet  exclufiively  (.■omtmaed  of  uvii* 

nHdollMad  fibfee  aud  conic  to  iIr-  miisclefl  frum  tbe  Bo-cul]e<i  lyntpaLlieiic 

mum.     Pawng  ■ut')  the  coanectivc  tiwuc  betweftn  the  bundlea  th«  nerve*) 

•iiiidt>aDd,ji>iiiin)^  ngmin,  fonn  b  plexus  around  tbe  buudie«;  thai  is  tAiuiy,  a 

t«ig  conxiftiHK  of  a  few,  or  perhaps  only  one  axis-vvliuder,  coming  from 

bfaocb  will  mn  alougside  of  or  join  a  itiniilar  «mall  twig  »>miiig  from 

Itmich ;  ibe  individual  ax ia-cy linden,  however,  d»  noi  thcjaiwlvM 

Kriim  sut-b  prinmry  plexuiu,  in  which  u  few  mrdulbiuul  tibrw 

H«  pnaeol  amoD);  tbe  iion-miKliillaied  tibi^,  arc  given  ofl'Mill  finer,  "  inler- 

Mfiluie"   plexuses  oiiwtAliag  excliisivclv  of  nun -mcdiillaiod  f;brc« :  thm 

fb»»ee  ths  smaller  bundle*  nf  rou»ctifar  fibre*.    The  branches  of  those 

flkmmm  majr  oonaiat  of  a  lingk  axi»-cylinil<-r,  or  may  even  be  (ilamenla  cor- 

Mpoadins  to  several  or  a  few  only  of  the  librillie  nf  which  an  axis-cylinder 

i>  Mppneeo  tn  be  coAiposm).     From  thwc  intvrmwiiacc  plexuses  ore  ;>iven  ofl* 

■i(ie  (brills  or  vcrv  small  tiiiodlt*  of  Rbnllir,  which  running;  iu  tbe  ceraeni 

■fafance  between  ibv  iti<lividual  libru  form  n  Kiie  network  around  ilie  indi- 

titaal  6bn»,  which  network  dilfers  frcini  the  plexuses  just  spitktu  of,  ina.4- 

nneh  M  sotuc  of  tli«  fil»nivnl«  composing  it  nppear  to  o<ialeK«.    The  ultimate 

MlbiK  of  this  network  has  not  yet  been  conclusively  traced ;  but  it  *eem> 

■ntaible  that  fibrils  from  live  network  lenuiuate  in  imiall  knobf  or  oirellings 

tfiaf  en  tbe  subsUuice  uf  the  muM-ular  l!breii,  somewhat  Jtdi-r  the  fn»hion  of 

■imile  end-plfllea. 

A  timilar  temiiDation  uf  nerven  in  a  pk'xiu  or  network  is  met  with  in 
mW  tisaues,  and  is  not  cimtined  to  uun-ni«dullaud  fibre).  A  mc^liillated 
fln  may  end  in  a  plexus,  and  when  it  does  ao  loses  Jinit  its  medulU  and 
nAis^flentiy  it*  neurilemma,  the  picxu*  becoming  uUinint<tIy  like  (hat  formed 
ha  Dun-mtdullntcil  fibre  nml  con»i.'>liug  of  attcnusictt  axis-cyiinilers  with 
uiokmin^  nnd  Htmrliniiv  with  wuctci.  at  the  nodal  points. 

itl.  As  far  n«  we  kimw,  plain  nui »cii hi r  tissue  in  its  chetuical  features 
nmaliln  strinlt^  muscular  tiwuc.  It  cinltiins  nibumin.  Aoine  formn  of 
dthslio.  and  anieeeduts  of  myosin  which  u|>on  tlie  death  of  the  fibres 
Mine  mronn  ;  for  plain  muscular  tissue  after  death  heoornes  ri^'id.  losing 
h  WenribilitT  and  probably  becoming'  acid,  ihouj^b  the  aetttity  \*  nut  M 
■vfcnl  as  in  ftrialcd  muscle.  Kreatin  has  also  been  found,  m  well  as 
fl^fogva,  and,  indeed,  it  swais  probable  that  the  ftbole  metabolisoi  of  ptab 
nmtar  tisaue  is  fundanwntally  tbe  same  as  that  of  the  tttriated  mueoka. 

t  n.  In  tlieir  {general  physioal  feaUiru  plain  muscular  fibres  nko  reeemble 
^risioi  fibres,  aiw)  like  tneni  they  are  irritable  and  contracltlc :  when  sUinu- 
htol  ibey  riinlraet.  Tbe  fibres  vary  in  natural  length  in  ditforont  •ituations, 
ikss  of  the  bloddveiMla,  for  iiwtjiuce,  being  shorter  and  mouivr  than  thoM 
W  the  intmtiu«  ;  but  in  iW  name  vituation  the  fibres  may  also  he  found  in 
*•  af  two  diflereul  rvMiditions.  In  the  one  ouc  the  tibna  are  long  and  thin, 
h  lh«  Dthrr  onse  they  arr  reducr<l  in  length,  it  may  he  to  one-half  or  even 
*f  •ae-thirr),  ami  are  c«)rr«wpoudingly  tliioker.  hroiuler,  and  Ins  poinicxt  nt 
Asiadf,  their  total  bulk  remniuiiit;  unBlCered.  In  the  former  case  they  are 
nknd  or  elongated,  in  ihe  inlter  caw  tbey  are  conlractctl. 
Til*  bets  of  the  ootilractioD  of  plain  muscular  tissue  may  be  studieal  in 


lo2 


TBB   OO.VTKACTILIC   TtHSUI 


tin  inUMin«,  tbe  miiacular  coat  of  which  coiiHists  of  an  uttter  thin  aheel 
oompoaed  of  fibrea  ajid  bundla  of  tibree  di9jioi«<i  lonfptuiliiiiillv.  ninl  of  on 
iunerniucb  iliicker  sheet  of  flbres  dispoBe^l  uircularlir;  m  the  uratera  similar 
«rnui]^tii<.'rii  of  two  coatA  oblaiu^ 

If  a  mechaDJcal  or  electrical  (or,  iiidted.  imv  uiher)  ftiniuluK  he  braufiht 
to  bear  <mi  a  [tan  of  a  fre^h.  living,  still  wurm  iiiluiliiie  (the  >mall  iuKwIim: 
is  th?  Kitt  to  work  wilh)  a  circular  cijriU'ticiiiiii  i»  Mxn  to  take  place  nt  the 
»IKit  iiliniulated:  tlic  iniisliiie  »eeiu»  nifiiHMl  in  ringwJM;,  n»  if  tied  miind  wilh 
an  inviitiblf  coni.  mid  llie  [larl  »ii  CDiistriitcd,  previously  vascular  and  red, 
becoueB  pnlu  and  bl<KiilIra».  Thr  individual  librcs  of  ibe  cm-ular  oooil  in 
the  region  stimnliited  have  ruch  htnyime  :<h()rtcr,  nod  the  total  effeei  of  ibe 
BhorteniD);  of  the  mullitude  of  fibres  all  having  the  same  circular  di8|>06iti«ia 
is  to  coDiilrict  or  narrow  the  lumen  or  lube  af  the  ioteetine.  The  longitudi- 
nallv  dispoiied  fibres  of  the  outer  lon);i[uiliDat  coat  will  at  the  eame  time 
aimilarlv  contract  ui  i^horl«D  in  a  loDjfitiidtnal  ilirecliitn.  but  (his  coal  Iwio); 
relatively  much  lliiutier  than  tbe  circular  coat,  the  lonKiludiiial  coolractiou 
in  allojiitfiher  oveti*hadowed  by  the  circular  cunUacliun.  A  similar  mode  of 
»iniracti<m  u  also  aeeu  uheu  the  ureter  is  oimilarly  stimulated. 

Tliv  contrnction  thuit  induced  in  preceded  by  a  very  Iniix  latent  (teriod  and 
lu»t>  a  very  coniiidi^rnhle  time,  iu  fact,  several  seooiitb,  after  which  relaxa- 
tiiin  (lowly  takni  jilace.  We  may  »ay  tlieo  thnt  over  die  Hrculnrly  diitpor 
fibres  of  tbe  iiitentiiie  (or  ureter)  at  the  spot  in  queittioii  iheri'  lins  pawcdj 
conlmction-wavc  remarkable,  fur  it«  long  lateJit  tn-riod  nnd  for  the  tlowiii 
of  it*  dovcl"[)mcnt.  the  wave  being  propH^tcd  Jrom  fibre  to  fibra.  From 
tbe  »pot  so  directly  stimulatnl  the  cx»ntraetion  may  piw  also  as  a  wave  (with 
a  len^'lb  of  I  cm.  and  a  velocity  of  from  'iV  to  ■in  millimetres  a  second  in 
the  ureter),  along  tbe  circular  cont  both  iipaard*  and  downward*.  The 
loofptudinal  6bres  at  the  sput  stimulatefi  ari>,  ns  we  have  nid,  also  thrown 
into  contractions  of  altogether  ainiilnr  character,  and  a  wave  of  contraction 
war  tbiu  also  travel  longitudinally  along  the  longitudiual  coal  butb  upwards 
and  ilowun-ania.  It  is  evident,  liuwever.  tluit  the  nave  of  contraction,  of 
which  we  are  now  ii|)eai(iiig.  u.  in  one  rt^jieet,  dillereut  from  tbe  wave  of 
ciintraetiou  lrcate<I  of  in  dealing  with  tilriaietl  miUK'le.  In  the  latter  i'AM 
the  ci>ntraet ion- wave  i.->  a  sinijile  wave  propa^iUid  along  the  individual  fibre, 
niid  starting  from  tbe  I'mt-philo  or,  in  the  ciim>  of  din-ct  stimulation,  from 
the  ])art  of  the  fibn-  first  ailectiil  by  the  otimtilus  ;  wc  have  no  i-vidcnc*^  that 
the  c-untniction  of  one  film-  can  communicate  conlractinn  to  neighboring 
6bres,  or,  indeed,  in  nnv  way  inHucnce  neighboring  fibres.  In  iho  case  of 
tlM  inUAine  or  urel«r  tltc  wave  w  complex,  being  the  sum  of  the  cuntmcti<Hi- 
WSTCS  of  several  fibres  engaged  in  <liliercnl  phases,  and  is  propagated  from 
flbre  to  fibre,  both  in  the  direction  of  the  fibres,  an  when  the  whole  circum- 
ference of  the  inteetiue  is  engaged  in  tbe  contraction,  or  wlien  the  wave 
travels  longitudinally  along  the  longitudinal  coal,  and  also  in  a  direction  al 
right  angles  t<i  the  axes  of  the  librea.  as  when  the  con  tract  ion -wave  travels 
lengthways  along  the  circular  coat  of  the  intestine,  or  when  it  paaies  acrots 
u  breadth  of  lite  longitudinal  coat ;  that  is  to  say.  the  changes  leading  to 
Ooniraction  aiv  communicated  tint  only  in  a  dire<a  manner  across  the  cement 
■ubslance  uniting  ihir  fibri-s  nf  a  liundtr,  hut  also  in  an  indirect  mantKr, 
probably  bv  nieaimof  nervi-  fibri^i  (Vom  bundle  to  bundle  acniwt  the  connvctive 
tissue  between  them.  Moreover,  it  is  obvious  that  even  tbe  oont ruction -wa\-v 
whidi  i}n»^  iilorig  a  single  unslriatcd  Khre  dificrs  from  that  pamiiig  alone  a 
frtrialed  Kbrv,  in  the  very  great  length  both  of  its  latent  jieriod  and  of  the 
duration  of  its  contraction.  lieiice,  much  more  •.■VBit  than  in  the  ciue  of  ■ 
Striated  muicle.  the  whole  of  each  fibre  must  be  occupied  by  the  contraction- 


A 


ox   SOMK    OTHER    rOKUa    OF    CONTRACTII.B    TI&HI'E.       1&8 

v«v*,  ud.  iodAet),  be  in  nearly  tli«  mine  phase  o(  tlie  coDlractivn  nt  tbe 
■Mline. 

\^*an*  of  DODLraolioD  tbiu  puwiiiji  aliinc  U»e  circular  and  loiii-iluduia) 
k  ■>f  ibe  iniesiirw!  raoBtiiute  irtiat  b  (-allt<il  pemialiic  at-tioo. 
jk«  xhv  <i>iitracti<JDi  of  vtrimlMl  uiU)M:Ii.-  the  coutniclioua  uf  plain  niuecles 

\t  b»  »t*nin]  hy  ttimulKtiuti  of  uiu-vtn  ic^ng  tu  the  part,  the  nerrea  sup- 
|i}ilif  plain  niiiMaUr  tilMie.  ruiinin);  fur  tlie  most  [tart,  u  ne  tiave  said,  in 
tbir*»w)e(l  *yn>p«lbetic  kynteni.  but  being,  ox  ni-  iiball  M-r.  iiltiiuutelx  c»u- 
DRWd  witb  thr  kpinnl  cnril  or  brain.  Hi-iv,  Ii<iwev<:r.  wi-  runiu  upuo  au 
Ifiiilllil  dUlinrlHrn  bHwm-n  ibv  ntrialnl  nkclttal  niuoi.'U'H,  ami  the  pluiu 
■wlw  of  tlM'  vMconu  Af  a  ^ncrnl  niliv  ibc  AHt-liil  niuiu;lt»  art;  thn>wn 
iUm  cvintnaninD  only  by  n«rvou'  impnli>e«  rracbine  them  ubin^  thoJr  nerriM; 
ifMUuMMU  tnuvvRicnis  of  tho  i^kclctiil  nuiBclra.  ibat  h.  contraction*  nrlalng 
nuof  changes  in  the  musclca  lh«inM)v«8  are  rstrcnicly  rare,  and  whcii  tboy 
genir  atr  abnormal ;  au-called  "  cramps  ''  for  Instancf .  which  are  pnilvngvtl 
Kinir  i.-iint  rati  ions  of  skeletal  inutclea  lodependeDt  of  tlio  will.  tli(>U);fa  tbeir 
Kttmae*  w  larvelj  due  to  tbe  ooudiiion  of  the  muscle  itself,  genernlly  the 
mull  (if  overnork,  are  probably  ai'tually  started  by  ncrv<iu»  impultee  reach- 
bctbcBi  truiu  without.  Un  llw  other  baud,  the  plain  muaclcs  of  tbe  viscera, 
(f  ^  blflstJiw.  uteni*.  and  ureti^r,  fur  iitMunc«,  and  uf  the  bloodvcMeU  very 
bi^wntly  fill)  into  coulractioiia  and  ao  carry  out  movements  of  the  organs 
u>  whirfa  ihey  belong  iguile  {nd^JcndcDtly  of  the  central  nervous  aystem. 
Tltar  (irgiaoi  exhibit  "  9j>ontimeou»  "  niovcmenU  <]uite  apart  from  tlie  will, 
ipirapttn  from  tbc  tvntral  nur^'nun  *y#ten),  and  under  favorable  circum- 
tiBtm  continue  to  do  tht*  for  »i>m«  time  after  thev  bav4-  been  entirely  isolated 
■d  rmuvnl  from  the  Univ.  80  slight,  indeed,  ii  the  connection  betweem 
■hanaranaitt  of  oi^ns  and  part*  ^lupplinl  nilb  pluin  miii'i-iilur  fibrea  and 
inW,  lluit  thcae  muKtilar  tibrea  have  ometiince  been  called  involuotaiy 
aoitiB:  but  this  name  ■•  undesirable. since  some  muwlM GOOneting  eiitirvly 
dftma  moacular  librea  (e.g.,  tlie  ciliary  muHclea  by  vbioh  tbe  eye  is  bccoiu- 
MataJ  for  riewing  objects  at  ditl^renl  diatancw)  are  directly  under  tbe 
iMiimwe  of  the  irill.  and  some  muaclea  conipoeed  of  striated  Kbrea  (c.  y., 
iha*  of  the  heart)  are  wholly  removed  fhint  tlie  influence  of  the  irill. 

Va  ihall  bt&i  siuily.  Imweror,  the  facta  relating  to  the  movements  of  parts 
fnriiM  with  plain  iniiacular  fi bras,  when  we  come  to  oonaider  the  parts 
AmmIvml 

UId*  the  skeletal  mu»clc»,  vdioec  iwr^'ous  element*  have  t>een  rendered 

fcHtiooally  iDcn|iable  (i  78),  plain  muscles  are  muoh  more  iwnHitive  to  the 

■king  and    breaking  of  a  constant  current  than  to  induction  nhurks ;  a 

~1|irat,  kIwu  very  bnof,  like  that  of  an  induciion-iJiock,  produce*  little  or 

.•ftvl- 

Thc  plain  iiiuxrlfla  iMm  to  be  remnrknbly  aufccnlible  to  the  iiiHiicnt-cs  uf 
lm[irratiire.  When  exposed  to  low  Umpi-tiitun^  tiicy  rcndily  low  ihc  (inwer 
*f  minrttDg  :  thus  the  movements  of  the  intcMJnc  nri'  »iiid  to  ccim;'  at  n 
ImpamUire  below  \it°  ('.  Vnriatii>n<  In  tcmperaiuro  have  aU'>  very  nmrked 
•fnt  nn  tlwi  duration  and  extent  of  the  contractions.  Aaaocialcl  probably 
tah  thi>  susceptibility  iii  ibo  rapidity  witb  which  plain  muscular  libra,  even 
b  eoU-blooded  vertebrates.  lo»e  tlieir  irritability  after  removal  from  the 
M*  and  severance  fmrn  their  blood-supply.  Thus  while,  an  we  have  seen, 
Ikticeleial  muaclea  of  a  frog  can  be  e3C[)eriitiented  upon  for  many  lioun  (or 
nw  fit  two  or  three  dava)  after  removal  from  tlie  lutdy.  and  the  skeletal 
■■■tia  of  a  manmal  fi>r  a  much  lees  but  alill  comitlurable  time,  it  !•  ■ 
WUffnf  rrry  gnM  dilficullr  to  im.-cuiv  the  c<intinuu»cv  of  luovemeoi*  of 
AtiuMtine  or  utherotgans  supplied  with  plain  iuu>culnr  librni.  even  in  the 
■Msf  Um  ftog.  for  any  long  |icriu<t  after  removal  from  the  body. 


164 


THE   CONTRACTILE  T198DES. 


TIm  contrnoiton  nf  nlnin  muttrtilitr  fibres  is,  u  w«  said,  very  ilnw 
dvwlopmeiit  iiiii)  very  long  in  it»  ilurttlion,  orcn  wh«B  sUrtmJ  liy  n  ni'tiiirii- 
tmry  atimuluR,  such  ru  n  einglc  inductimi-shoclc.  Tho  contriK-tum  :illor  h 
MiiauUtion  often  ImU  so  long  w  (o  rniso  tho  qimtion,  wluttber  irhRt  liii*  been 
produced  a  not  n  single  contraction  but  a  tctttniis.  TebiniiE,  how^riT.  thiit 
IK,  the  luaion  of  n  eeriei^  of  contritctions.  weins  to  be  of  rim  occurrence, 
lhou;;h  probably  it  may  be  indoceil  in  plain  muscular  tiaasuo:  but  the  eadt 
of  leianus  are  gained  by  a  kind  of  contraction  which,  ran  or  ni  lead  not 
prominent  in  skeletal  nuiecle.  beconiea  of  great  importance  in  plain  musculST 
tisaue  by  a  kind  of  coiilracliuu  call«d  a  (onie  contraotion.  l^ie  subject  is 
on«  not  without  difficultiett,  but  tt  would  ap(>ear  that  a  plain  muscular  fibre 
inay  remain  for  a  very  considerable  time  in  a  state  of  oontractJuu.  the 
amount  of  «liurt«oiny  thui  maiiitaiTied  bein;;  either  sniull  or  i^rcau  ;  it  t«  Iheu 
said  to  l>e  in  a  ttLale  of  tunic  contraction.  Thin  ta  eapcciallr  netm  in  the  c»»e 
of  tbu  pluin  muHciiIitr  tiiuiue  iif  lh<!  nrtt^riu*,  and  wc  shall  nave  to  return  tv 
tb!«  matter  in  di-aling  with  the  oirenlnlion. 

Till-  inusnilnr  liivmi^  nhich  enters'  into  the  ooniiU'uctton  of  the  Ikcart  is  of 
a  peciilinr  nature,  bi-in^  on  the  on«  hand  iitriutcd  and  on  the  other  in  aftinB 
nisneet*  Mmiliir  Ui  plain  muscular  tiMUO,  but  thi»  we  Mhall  considvr  in  dcalii 
witn  tho  bmrt  itself. 

Ciliartf  .VoweHiwif. 

^  93.  Nearly  all  the  iDovemeot«  of  the  body  which  are  not  due  to  phyiic 
causes,  such  as  gravity,  the  diHiiftion  of  liqnida,  etc.,  are  carried  out  by  mus- 
elee,  either  striated  or  plain  ;  but  some  small  and  important  etiecu  in  ibe 
way  of  movement  are  produced  by  the  action  of  cilia,  and  by  those  cbaugcs 
of  pruloplasin  which  are  <-alled  aniiebiiid. 

Cilia  nro  generally  n|>peii<lai[t!.H  of  epithelial  cellit.  An  epifhrlinm  cnn*ii)ti 
of  a  number  of  cellit  nrrangefl  in  a  layer,  ono,  two,  or  more  celU  deep,  the  cell 
bodies  of  the  coiKtttucnt  kkW*  being  in  contiict  with  each  other  or  united 
mcnly  bv  n  minimal  amouiU  of  wmeiit  onWlanee,  not  «panilc«l  by  nn 
aj>preciable  quantity  of  intercellular  material.  As  a  rule,  no  conoc^rtire 
tosue  or  bloodvcasef  pni«M  between  the  cells,  but  t)ie  layer  of  cell*  resU  on 
«  basis  of  vascular  connclive  tissue,  from  which  it  is  usually  separated  by  a 
more  or  lens  definite  bnscrnenl  membrune.  and  from  the  bloodvenolsof  whjeb 
its  cells  draw  their  nourishment.  The  cells  vary  in  tbrm,  nod  the  coll  body 
round  the  nucleus  may  be  protoplasmic  in  appearance  or  mav  he  diHenenti- 
aled  in  various  ways,  An  epithelium  bearing  cilia  is  eafled  a  ciliaieil 
epithelium.  Various  passages  of  the  body,  such  as,  in  the  mammal,  parts 
of  the  nasal  chambers  and  of  the  respiralory  and  generative  passages,  are 
lined  witJi  ciliated  epithelium,  and  by  the  action  of  cilia  fluid  couiuiniiig 
rarioin  panielm  und  ttt^uemllv  nior«  or  less  viacid  is  driven  outward  along 
the  pamagen  tnwnrd  the  exterior  of  the  body. 

A  typical  epithelium  cell,  .-luch  nn  may  be  found  in  the  trachea,  is  gvne* 
rally  sumewhiil  wedgushajied  with  its  broad  end  circular  or  rather  polygonal 
in  outline,  forming  purl  of  the  frcR  surface  of  the  rpitbcliuni,  and  wilh  tie 
narrow  end,  whieli  miiy  be  n  blunt  point  or  may  be  somewhat  hniiiched  and 
irrvRiilar.  plunged  among  small  subjacent  cells  of  tho  cpilhclinm.  or  renching 
to  the  ciuiticctive  lii»uc.  Iielow. 

The  cell  body  is.  over  the  greater  purl  of  its  <'Xt«nt,  composed  of  proto- 
|>lasm  <Tilh  the  usual  gniniilar  iip)>cnrHnce.  At  nbout  the  lowcrthird  of  tfa« 
cell  is  pluced.  wilh  ile  long  aiiis  vertical,  an  oval  nnclens,  having  the  ordi- 
nary cliaraclere  of  n  nucleus.  80  far  the  ciliated  cell  resembles  an  ordinary 
epithelium  cell ;  but  ilie  free  sur&ce  of  the  cell  is  forioed  by  a  layer 


ON  SOHB  OTUBR   FUltUS  OF  COKTnACTILB  TISSUK.      155 


kysliM  trnospareut  soroewluit  rvl'niciiv«  (uUunw  whinb,  whtm  ih«  nil  is 

MP.  M  unuftl.  ill  profile,  mppt^in  n  n  hyiilinc  rpfrnrtivo  bnEi<l  or  bonier. 

VroiB  U)i«  b<iT<lt>r  ihi'rc  |inij««t  ouiniiril  n  VAiiiibln  niiiiihi.T,  IC  t<>  -t'.),  tklU 

nttr  iBpmnfc  liair-liko  tilftmeoM,  Tnn'ine  i»  l<'ngih,  but  gvmi-rally  nboiit  ii 

•(tiuUT  or  ft  tliini  u  long  U  Uio  eolt  ibwlt';  thcw  arv  the  i-ilia.     liiinKtliatcly 

Mu«  llii*  hy«lini:!  lM>nlvr  iW  orll  Fulwiuictt  often  «xhibil»  more  or  Imr  ilis- 

tbetly  ■  luaKitu-liiuil  ftrmtiuti,  lini.-  linos  pM§ing  down  from  ibe  hyaline 

V  lowHnf  the  lower  part  of  the:  cell  euUtetici'  mund  the  niicloiu.     Tim 

bordar  itaelf  asuallr  cKhibiti^  a  striatiaii  as  if  it  n-ero  split  up  into 

■rh  block  corresponding  to  one  of  ibe  cilia,  nod  c«re(ul  examitia- 

liM  loMfa  to  the  conclusion  that  ( he  hyaline  Imrder  ia  really  ooinpoaed  of  tlie 

Ibtd  tbiokar  baeal  parts  of  the  cilia. 

Hi*  mail  body  has  no  distinct  external  luenibrane  or  envelope,  and  its  sub- 
KMCf  is  in  close  cuntact  with  that  of  its  iiei|;hbor»,  beiuK  nnited  to  them 
albcr  by  B  tbin  layer  of  Mine  ceiueiil  substaooe.  or  bv  the  siuiple  cohesion 
«f  ibHr  rutieclive  surfiices.  At  all  events  the  oetlfl  do  cnhere  laif^ly 
ii(Hbcr,  aii'l  it  'm  dilficull  to  obtain  an  itolntcd  livinf;  cell.  thou)[h  tlie  cells 
uy  be  evily  *cparaivU  from  each  other  when  dead  br  the  help  of  diMooial- 
iif  lluMii.  WbMi  a  cell  in  obuitued  is»]ut«l  in  a  living  state,  it  u  very 
twiacatlT  fwund  to  hare  Imi  iu  ncd)pi  fhii\v.  and  to  hari;  become  more  or 
^Jb  htnjtpberictl  ur  oven  Htibcrii-al ;  undi-r  the  Utnal  cxiditiuns,  and  fre«i| 
^|Bb  tlw  Mpport  of  its  ncigiibon.  the  cell  body  change*  it*  f»rm. 

^rksgnMralcharactenjuKt'liwrilmlnreooRinion  toall  ciliated  cpitbeliiiui 
(ilk  Ml  lbs  cell))  in  diircrciil  niluntiouH  vary  in  certain  |)articular«.  nivh  as 
Asritrl  form  of  the  cell  IicmIv,  the  number  and  length  of  the  cilia,  etc. 

I  H.  (~iliar}-  actinii,  in  lliv  ionn  in  which  il  is  moM  common,  in  mammals 
ud.  iodei-d.  vi-rtcbrsle*,  consists  in  tlw  cilium  ( ■'.  r..  th<^  tsfierinp  tilamvnt 
ifiikto  of  alxtvc  I  being  at  one  tnomeat  straight  or  vertical,  at  the  next 


wt  b«ia;c  beni  <loivn  suddenly  into  a  houk  or  Dii-kle  form,  and  then  more 
4mh  returning  to  the  straight  erect  ]>oailion.  WIteu  the  cilia  are  vigorous 
Ail  double  nwremeni  is  repeated  with  very  great  rapidity.  «(•  rapidly  that 
4r  indiridnal  movements  cannot  be  seen :  it  is  only  wlieo,  by  reason  of 
favun,  the  aotioa  becomes  slow  that  the  moveraeat  Itself  can  be  seen  ;  wliat 
itsMo  iithtinriTC  b  simply  tbe  efltrt  of  tl>e  movemenL  The  miiverucnis 
ttsBslow  hnvv  lM-enc»unied  at  about  eiubt  (double  nuyvetnenis>  in  aseciind; 
imMkly  when  rigonxn  they  are  leiNuiteci  from  twelve  to  twenty  tinuv  a 


IV  flrxiot)  lake*  ntim'  in  one  dircctiim  only,  aixl  all  the  cilta  of  each 
mI  and.  indrvil.  of  all  the  cell*  nf  tbe  name  epilheliiini  ni'ivc  in  the  safllO 
AiMfioo.  Moro')vi>r,  the  Mtmc  direction  >■  maintnimil  itiiring  Uie  whole  litiB 
rflheepttheliuoi;  thuo  iho  cilia  nf  th<^  epiihelinm  of  (hit  trachm  and  bmn- 
■Ual  oaaagaa  more  during  the  whole  of  life  in  »ueh  >  way  ss  to  drive  the 
JaU  Ijrlng  opon  them  upward  toward  th<-  mouth;  a«  ftir  as  we  know,  in 
rsias,  or  at  least  in  mamiDals,  the  dirvction  ts  not  ai»(l  cannot  by  any 
be  rweneil. 

TleBexion  it  rm-  rapid.  Uiil  the  return  to  (he  erect  |>i>^ition  is  mneb 
ikmt;  hence  the  total  etiect  of  the  blow,  supposing  the  ciliiim  and  the  cell 
)*)|«  Used,  is  to  drive  the  thin  layer  of  lliiid  in  which  the  cilium  is  working, 
•kl  which  always  exists  over  the  epithelium,  and  any  {)articlf»  whidi  nuiy 
Wfinstini;  in  that  Huid  in  tite  same  direction  as  that  in  which  the  blow  ia 
fina.  If  (he  cell  be  not  attached  but  Hoatin^  frv«  tbe  eflect  of  tbe  blow 
aav  bs  tu  drive  the  cell  iLwIf  backnanl;  and  when  perfectly  freali  ciliated 
rfiibiiuni  is  b»aed  out  and  examineil  in  an  enen  fluid,  such  us  nurmal 
alia*  fciliitiuu.  isolated  cells  or  amall  jft^ups  of  cells  may  be  ween  rowing 
Asodves  about  as  it  were  bv  the  action  of  their  cilia. 


1S6 


THE   CONTBACTILE   TISS0B8. 


All  th«  dim  of  a  od)  mov«,  a»  we  liave  juttt  Mid,  to  tilt  mow  dtTtntioil, 
bill  net  <iuile  nt  lite  aaoi*  time.  If  nv  cnll  llio  siclv  of  the  oell  townril  whkb 
the  viliii  bdiii  the  front  of  the  c<:!l  nud  th«  ornxMite  n-vin  th«  back,  tlit-  dlU 
Ht  the  bnck  move  n  tritlt-  bcf^irc  thiM«  at  toe  front.  e»  (lint  ihv  movement 
runt)  over  the  cell  in  tlii;  dircctiun  of  the  ixioveineDt  itself.  HimilnrlT,  taking 
nay  oDe  cell,  the  ciliu  of  the  c«lls  behiixl  it  move  slightly  before.  And  th* 
ciltn  of  the  L'clle  in  front  of  it  slightlr  iifker,  ile  uwn  cina  move.  Hence,  in 
tht»  wny,  aloD);  a  whole  elretch  of  epithelium,  the  inoveineDt  or  bending  of 
the  cilia  sweeps  over  ibe  snrfiice  in  rip|)]cs  or  waves,  very  niueh  as.  when  the 
win<t  blows,  siriiilnr  wnves  of  bending  sweep  over  a  field  of  com  or  (all  grtM. 
By  this  arraii;;emeiU  the  elRtacy  of  the  moveiueiit  i*  secured,  and  a  staoily 
stream  of  6util  carryiii;;  tiurllclea  is  ilriven  over  the  surface  iu  a  uniform 
coiiiiniied  ilireetion:  if  the  eilta  of  separate  cells,  and  atill  more  if  the 
segiarate  cilia  of  eueh  cell,  moved  iiule))endently  of  the  otliers,  all  that  would 
be  girudiieed  would  bo  a  leriea  of  niiuute  "  wubblM."  of  tu  little  use  (or  drir- 
inj;  the  lluid  dcfiiiilL-lv  onward  a»  the  ufTorla  of  a  boat'*  crew  all  ruwinjic  out 
of  lime  an  for  ]ini[H.-llinu[  the  boat. 

Swift  bending  nud  nliiwer  i>lniij;1ilcMiiig  in  the  form  of  eiliari'  movement 
generally  net  with  in  the  cilint<'d  epUbeliinii  of  mammalH  and.  indc^],  of 
vertebntteii ;  bill  nmong  the  iitverU'liruii^  vcv  find  other  kiiidii  nf  movonicot, 
such  ii>  a  irt  ami  fro  moveineiil.  c(|iially  rapid  in  Imth  din-ytionx,  a  i-urk-ecrtw 
movement,  a  Himple  uiiduliitory  moTement,  and  many  others.  lo  each  caw 
the  kind  of  movement  seems  adapted  to  secure'  a  snecial  t-od.  Thu«  even  in 
the  mammal  while  the  one-sided  blow  of  the  eilin  of  ihe  cpilhclial  cells 
Bocurea  S  How  of  tlnid  over  the  opithelhim.  ihe  tail  of  the  i'i>erninlazoon, 
vhieh  is  prnctieally  a  siuffle  cilium,  by  movinj;  to  nod-fro  in  an  iindulalory 
liashioD  drives  ibe  head  of  tbe  speruiato/.oon  onward  in  a  straight  line,  like 
a  boat  driveu  by  a  single  oar  worked  at  tbe  steru. 

Why  and  exactly  liow  ihe  cilium  t>f  tbe  upitbebal  cells  beads  swiftly  ami 
itmifcbtens  slowly,  nlway*  nctinj;  in  the  same  direction,  is  a  nroblem  difficult 
at  proont  tii  aiiNweT  fully.  Some  have  thought  that  the  body  of  the  cell  is 
conirnctile,  or  eonlnins  coutrtictile  mcchnuinmii  pulling  ujk»i  the  cilia,  which 
arc  thui'  riiuplc  pawivc  pupp*'t»  in  the  hands  of  ihe  oellii.  But  there  is  no 
satisfnetory  evidence  for  such  n  view.  On  tlic  whole  tbe  evidence  U  in  fnvvr 
of  the  view  that  the  action  is  carried  out  by  the  cilium  itaelf.  ihiil  the  Ix-nding 
is  a  coDtraction  of  tbe  cilium.  and  that  the  slraightoniDg  corre.<|H>tids  to  the 
relaxation  of  a  muscular  Hbre.  But  even  then  (he  exact  maaner  in  wbich 
the  conlraction  bends  nud  the  relaxation  strnightens  tbe  tilnraent  is  not  fijlly 
explained.  We  hnve  no  positive  evidence  that  a  longitudinal  half,  tbe  iDside 
we  mit>ht  say.  of  the  tilnineiit  is  conlructile.  and  the  other  half,  the  outside, 
eiaiilie,  a  suppoMtiou  which  has  been  made  to  explnin  the  bending  and 
Stmi};htL-ning.  In  fact,  no  adeipiate  explanation  of  the  niatler  has  as  yet 
been  given,  and  it  is  really  only  un  general  grouuds  we  conclude  that  the 
action  is  au  edeci  of  cuntnictility. 

In  the  vertebrate  animal  dliu  an-,  lu  far  a.«  ive  know,  whollr  independent 
of  ihe  lu-'rvous  system,  and  their  movement  ia  probably  c«nsefeea.  Iu  aucb 
nnimnb,  however,  ns  infusoria,  hydrnxun,  etc.,  the  movements  iu  a  ciliary 
tract  may  ollei)  be  seen  to  s[oj>  and  to  gu  on  ugaiu,  to  be  now  fast  itow  alow, 
according  (o  the  needs  of  the  economy,  and,  ns  it  almost  seems,  acoonllng  to 
the  wilt  of  the  creature;  indeed,  in  some  of  thew:  aiiimnls  the  ciltnry  move- 
ments nre  clearly  under  the  iritliicnce  of  the  nervous  system. 

Olieervations  with  gnlvnnic  currents,  constant  und  iuterruptcd,  have  uol 
led  lo  any  satisfactory  results,  and,  as  far  iw  wc  know  nt  prcsenl.  ciltnry 
action  i.i  moat  airecli.-<l  by  ehan^ea  of  temperature  and  chemical  media. 
Moderate  heat  ouickens  the  niovemeuts,  but  a  rise  of  temperature  beyond  a 
certain  limit  {about  40'  C.  jn  ibe  case  of  the  pharyngeal  membrane  of  the 


ox  iOXB  OTllKR    FORMS  OP  COyTttACTtLE  TISSL'E.      157 


from)  hnamt*  Injariout :  colil  raUnb.  Very  Hiluto  alknliw  «re  fitvonibU!, 
BCW*  u*  iajuriou*.  An  csccw  of  earhoiiic  nciJ  m  mn  nbofim  or  oxvgitn 
ditsiiaUM*  or  arnvt*  th<>  movcmeiiu,  nthft  u-mjxinirily  i>r  [>crni»i>rtitly, 
toooHiig  10  tb*  Icogtii  of  the  •xponiro.  Chloroform  or  pthor  in  sligl'it 
*  ~~~ldmlldriMiorwq>ta(ls  thttMUoD  t«iii()oninl]r,  in  L-xcna  kills  inil  dis- 
Ibeoelk 

AwrhtHrl  J/otemenb. 

tM.  Tlic  Khiti*  blood -rorpUKl«s.  m  we  hare  aaid  (_i3fi),  atv  sbl«  of 
iboMKlvM  to  dkuii'e  iheir  form  uid  by  repeated  change*  of  form  i«  move 
(MB  pUm  to  place.  Kiich  laovemcDtH  of  tM  aubstance  of  the  corpuselei  on 
(^M  RRKeboid.  siucc  ihey  clowlj-  resemble  and  appear  to  be  idcDtieal  fn 
wtaiTT  Willi  the  niovemenu  executed  by  tlie  aniceba  and  limilar  orftiinivott. 
IW  DinrciucDi  uf  ihc  eiiiloplosn]  of  tlie  vegetable  cell  Means  al»o  to  be  of  ilic 
■me  kind. 

Tbr  aiH'pba  obangn  ita  form  (and  ibifta  its  jtlwe)  by  throwing  out  pro* 
jcrtinni  of  ita  wbManoe,  cnllei)  {iM-uitopiHliu  which  uuiy  bo  blunt  and  abort. 
MWil  hiilginga  lu  it  vtn,  or  may  be  t«o  loug  and  tbiii  a^  to  be  men  filammta, 
•  may  br  '>f  an  inifrotedialc  cniimcter.  A«  ««  watch  the  outline  ul'  tJio 
bslnie  cvtoMrv  we  mny  *ec  n  [woiidopodium  bi!giniiin){  by  a  flight  bulging 
rftha  oatline:  the  bulging  incn-ntw  by  the  tiTighlxiring  pi>rhons  of  ihi' 
td/mn  moTing  iniu  it,  iIh-  movcRK'ni  iiiidcr  ihc  niirrorcopo  reniindiii);  one 
rf  iba  fl<nriiw  of  melted  ghm.  Af  the  jicoudopodium  grows  larger  and 
Mfia  the  whole  thickneac  of  the  eotccurc  at  the  spot,  ibe  graotike  of  (he 
mSmn  ri«t  be  wen  ftreamiug  into  il.  foraiioe  a  core  of  endoaare  in  the 
■idilk  of  li>e  bulging  of  ec(oear«.  The  peetidoixHlium  mny  continue  tit 
pw  largar  and  larger  at  tlie  cxpenae  of  the  r^t  uf  the  body,  nud  eveutunlly 
ik  wbcilp  of  lhi>  amn-ba  including  ihe  nucleua  may,  lu  »  were,  hiivr 
fMad  into  the  iiwudoptHliuiu:  the  body  of  the  aoweba  will  now  ncctipv 
Aa  bIm*  of  the  paeudoiioitiiini  iuateod  of  it«  old  place;  in  other  words,  il 
«(llw  cbMngina  ita  fonn  hare  aha  ebang«d  itd  plane. 

Daring  aU  t£s>«  movementa,  and  during  all  »iniiliir  nmaO>oid  movem«-nt*. 
iWkalk  uf  the  oiganiam  vill,  a*  far  a*  can  be  aNCLTtniuiil,  have  reinainc«l 
Mckaagnl:  the  ihroaingoiit  a  fwi'iidutiadiiiin  in  nnedirrction  U  nccnm|>anie(l 
bsmrmipondiiig  rttraclion  of  the  nody  in  other  dircrtimw-  If.  a*  N>me- 
liDin  ha{>]rRe,  the  i>r^ni«ni  throwa  Mit  nwiid>i|KHlia  in  varimx  directions  at 
ll>  Hne  time,  tbe  main  boily  from  nhicli  the  perudiipotlia  prnjccl  is  i^uced 
iidileluieaB ;  from  being  n  vplu-ricnl  tump,  lor  instance,  il  b<-cnn>ca  a  bmnched 
CIk.  The  moreoent  it  hmiighc  nltout  not  by  incrcar«  or  decrease  of  nub- 
Mum  Iwl  by  nere  tranalocntion  of  particles ;  a  particle  which  at  one  nM>meut 
W  ia  one  pawUon  nwves  into  a  new  [xjeition.  several  particles  thus  nioriitg 
ttaird  the  aarae  point  cause  a  bulging  at  thai  |N>ini,  and  several  pariidea 
■uriof  away  from  the  same  |>oinl  cause  a  retraction  at  that  ptint ;  but  no 
t*«  futielea  get  nearer  to  each  olher  m  as  to  occupy  together  Ibm  spacp  and 
tlai  had  to  oandenaotton  of  substauee.  or  get  furt^  tVoin  each  other  h>  a.i 
teiecupT  mote  apace  nnd  thus  lead  to  iocreme  of  bulk. 

la  tBu  rMpact,  in  that  there  is  no  change  uf  bulk  but  only  a  shifting  of 
(■Rklca  in  tncir  relative  position  to  each  other,  the  snin-butd  movement 
MHtbteaa  muacular  Mmlrairti'io;  but  in  other  reapecls  the  two  kind*  of 
■amaal  seem  diff)-n>ui,  and  the  (|U«Mi««  ariaea,  hare  we  the  right  to  apeak 
xt  (he  aabounce  which  can  oulv  exeoutc  niti<i-1md  niovementa  m  beiitg  eou- 

Wa  naT,  if  we  admit  that  contractility  ia  at  bottom  simply  the  power  of 
4ifiaw  ifie  relative  poailion  of  pnrticlte.  nnd  (hat  niu^cnlar  contraition  t*  n 
ifaraujze<l  fTw  nf  contraction.     In  n  plain  muscular  fibre  (which  we  may 


158 


THE   CU>'TBACTILi:  TISSDBS. 


tuk«  ukiinpler  itmti  tb<^  Atrtuied  muMle)  the ahiftlng  of  nartides  is  special- 
ised ill  the  trni-  ilint  it  tiiu  iilmiiyisdeniiiM  nlatioB  to  t&e  loDg  axis  of  liie 
fibre :  when  t\u-  RUtv.  coiitraciH  »  curtain  number  of  nartiolo  umiiue  a  nev 
nwition  by  moving  nl  riglil  aiiglisi  tn  the  King  iixii>  iif  the  fibre,  and  ihe  fibre 
in  cdtiwi^uiMRT  lin'onie*  vJiorler  anil  brotiJer.  lu  n  wbit«  blood 'Curputcle, 
UUKcbn,  or  other  urgnuiMii  fxeniting  umo-boi'l  miiv^mcnlii,  the  tliiAiiitf  of  tite 
particles  ia  not  limitod  to  taiy  axis  «l'  itu-  bmly  of  tbe  or^nnivm  ;  nl  the  immt 
moment  one  pnrLicl«  or  ono  sot  of  piiriiclot  inav  be  moving  in  one  diroctiun. 
mill  nnolher  pnrl!i.'l«  or  nnutlier  sel  of  particles  in  lUiolncr  ilireclion.  A 
pMudojHHliuin.  fbort  and  brand,  or  long,  tJiin  aiid  lilamcntoiis,  may  be  ihriM 
out  from  any  part  of  tlio  surface  of  the  body  and  in  any  direction  ;  and  a 

Sreviously  existing  pseudopoiliiim  may  be  sborLeiied.  or  be  wholly  dram 
Bck  into  tbe  siibsLance  of  the  body. 

In  tlie  plain  nmscle  fibre  tbe  fact  that  tbe  shifting  is  speeialixed  in  rolation 
to  the  long  axis  of  tbe  fibre,  KMCemUtes  that  in  a  conlrsctioD  tbe  shortening, 
due  to  tbe  particles  moving  at  right  angles  to  the  long  axis  of  the  fibre, 
should  be  followed  by  wbal  we  have  called  relaxation  due  to  the  particles 
moving  back  to  take  up  a  {tositiuii  in  tbe  long  axis ;  and  we  have  several 
timet)  insisted  on  relaxaiion  being  an  eosential  part  of  tbe  total  aci  of  con- 
Iraction.  If  no  sucb  moveuient  In  tbu  direction  of  relaxation  took  place, 
tbe  fibre  would  by  rejwuted  cnntracllona  be  tlatleiied  out  into  a  broad,  thin 
film  al  right  angles  to  Its  ongtiml  long  nxb,  and  would  ihuti  become  u»el««. 
A  spherical  while  bloiHl-curpiiicle  luay,  by  rv|>eaied  contract  ions,  r.  e.,  aimeboid 
niovemeuta,  tmiiHlorm  Itself  into  such  a  broad  thin  lilm;  btit  in  such  a  euo- 
dition  il  i»  not  useluo.  It  niuy  remain  in  that  cmidition  for  mime  lime,  ami 
by  further  eontracliuiia,  /.  i-.,  am<oboid  mnvcTnenta,  may  awiuDie  otlMir  shapes 
or  reviu't  to  the  »])liericid  form. 

So  long  nji  we  nnrrow  our  iileu  of  conlrai'tilitv  to  wlml  we  Me  in  a  muKCular 
tibre,  and  understand  by  contraction  a  movement  of  particles  in  relation  lo 
a  delinite  axis,  necessarily  followed  by  a  reversal  of  the  movement  in  tbe 
form  of  relaxation,  we  shall  lind  a  diliiciiliy  in  speaking  of  the  euljslance  of 
the  amixba  or  of  the  white  blood 'Corpuscle  as  being  coiilnictile.  If.  however, 
we  conceive  of  contractility  as  being  essentially  tbe  power  of  sbiftius  tJie 
position  of  particles  in  any  direction,  without  change  of  bulk  (tbe  shifting 
being  due  to  inirinsio  moleculiir  cbange^  abuui  which  we  know  little  aare 
that  chemical  decompowtions  are  concerned  in  the  inatler),  we  may  speak  of 
the  substance  of  tbe  oniceba  and  while  blood -corpuscle  as  being  contructile, 
and  of  muscular  contracdoti  uh  being  a  sjiecialized  kind  of  eonlractiou. 

llie  protoplasm  of  the  amoeba  or  of  u  uhile  corj>usole  is,  as  we  bare  Mud, 
of  a  contialency  which  we  for  want  of  l>etier  tenuit  call  iiemi-solid  or  mu^ 
tinid.  Consequently  when  no  tnteniat  cbunges  are  prompting  its  ]ianicl«t  Co 
more  to  this  or  that  direction,  the  influeiiiex  iif  the  surrounding  will  tend  tO 
give  the  body,  ii»  ihey  will  nthi-r  fluid  nr  M-mi-ftuld  drops,  a  apherirnl  form. 
Hence  the  naturitl  form  of  the  nhitt*  ccrpiiMcIc  iti  mure  or  leas  spherii'al.  If, 
under  the  influence  of  K>me  stimuhm  inte.riml  or  exlenud,  some  oT  the 
particles  are  stirred  to  »bifl  their  place,  emieboid  mnvenieiits  follow,  and  the 
■pherical  form  is  lo«t.  If.  however,  all  the  oitrticlus  wero  stirred  lo  move 
wtlb  equal  energy,  they  would  oeutralin^  cacti  other's  action,  no  protmnoa 
or  rctractioD  would  take  place  at  any  point  of  the  surliico,  and  tbe  body 
would  remain  a  sphere.  Honco  in  extreme  stimulation,  in  what  in  the 
OKHcle  corrffiponils  to  complete  tetanus,  the  form  of  the  body  is  the  same  as 
Id  rvst ;  and  the  tctaiiiied  sphere  would  not  be  apnreciably  smaller  than  tbe 
sphere  at  rest,  lor  that  would  imply  change  of  oiilk,  but  this  as  we  have 
teen  does  not  lako  place.  This  result  shows  strikingly  the  diflerence  between 
the  mneral  contractility  of  tbe  a]u<eba,  and  the  sjiecial  contractility  of  the 
macde. 


HAPTER    TH. 


(«  TIIF.  MOKE  (iKNERAL  FEATURES  OF  NERVOUS  TISSUKi. 


tM.  Ik  ibc  prcrexliug  rhii{itfr  wo  have  denll  witli  tb«!  pro|>«riieei>rii«rTe« 
pitf  lo  niHCK».  ih*-  ii«r\-c*  wliich  we  citllott  motor,  ami  linvc  iiicidGUtally 
HUiHl  of  Othif  nen-f*  which  wr  ciilli-d  rrnmry.  liulb  tfa^ic  kinds  of  tieri-ce 
vtoowiMtttl  witli  (l)i-  brnii)  iind  »|>iiinl  curd,  ami  fonii  pnrt  of  the  general 
■fmoj  ajvtrDi.  Wv  nhall  hnvp  to  study  hcrciiftcr  in  d<;iail  the  hrtiin  and 
4iuJ  ctiro ;  IniI  tlir  ncrvuits  »_V(U'm  inlervcncs  ei>  ropenlcHlly  in  the  procpt«efi 
dfriid  out  hy  other  Umum  thut  it  will  he  deeirnkte,  before  |)roce«diu|; 
faltkcr,  tu  diM-tiM  tOBM  of  it«  mora  general  features. 

Tht  oervmu  ayfrteni  iv)iMiBlB(l)  of  the  brnin  and  ^irnil  cord  [Via.  44]  form* 
i^loprtlier  Ibe  erreiiron/'imtl  Oirit  nr  erntml  iiemiu  lyt'ein,  (2)  of  the  iMrivv 
fwlKf  f^ih  lliikL  axis  to  nearly  alt  jtarla  of  ihv  bodv,  thwe  which  are 
«H«AmI  with  the  Hfiiiial  c-anl  h«iD^  culled  tfiiu-il  and  tliowt  Hhich  are  cuu- 
with  the  brain,  tiiihlo  tl»e  eraniuni,  being  called  emniW,  and  (3>  of 
ftta  distributed  along  the  nerves  in  varioua  paria  of  the  body, 
bf  tpitial  cord  obviouHly  oonalsis  of  a  number  of  veii^nieiila  or  nietamerca, 
ving  tu  niorewiiiai  aloog  its  usis,  each  metaraere  giving  off  on  cai^  aid* 
■  [air  nt  Bi>iiuil  uervcH ;  and  a  Hiniilur  divi.-iun  into  nurtaiuo-rfti  may  lit-  trnocd 
klhe  hraiu,  though  \em  di^linRtly,  linci^  iIm:  cranial  uervv*  tirv  arrungtd  in 
amatr  ■omcwhM  dJfiiBrail  frvm  ihiil  uf  tho  spinul  ucrvce.  Wv  may  take  ■ 
diA  apinal  metAin«r«,  r«(>reBeiit«d  diagrunimalicalty  in  Fig.  45,  as  illus- 
tnnu  ihc  general  features  of  Um  n«rToiU  system  ;  and  since  the  half  on 
<w  aw  of  ilie  median  line  reeetnblee  the  half  on  the  other  ude  we  may  deal 
«ilh  oae  lateral  half  only. 

EMxh  spinal  nerve  arises  by  two  roots.  The  metamere  of  the  oeotral  ner- 
IW  tytUm  i.'  consists,  as  we  slioll  hereafter  see,  of  ^ray  matter  Or  in  the 
iHmur  and  whit«  matter  M'  on  the  outside.  Fmm  the  anterior  part 
tf  (ny  matter  is  given  off  the  anterior  nerve  root  A  and  from  the  posterior 
luo  posterior  iK-rve  root  P.  The  Utter  naaaea  into  a  spelling  or  ^an- 
0,  "  the  ganglion  of  the  |MiMerior  root, '  or  more  shortly  "  Uie  uniial 
";  the  anterior  rout  di>e>  not  pit-w  into  thi»  nuigliou.  Ueyona  the 
.^  _.j  tfat  roots  join  11  form  the  ui^rvt'  trunk  .V.  Wc  ihall  later  un  giro 
isvidtoc*  thiil  Utv  nerve  lihrra  ci)m|H>tting  ihc  pcaitcrior  riHit  /'are.  a»  ikt 
kvc  know  at  pri-M'nt.  exdntivcly  ciccupinl  in  currying  ncrvoiui  im)>uhNa 
fiaa  ll>v  tiMuts  of  llw  iHHiy  to  the  central  uerromi  fy>t<-ni,  and  thai  the  f\hm 
•Vpodng  tl>c  anterior  rwA  A  arr  similarly  occupied  in  carrying  impulwcs 
fca  thr  n-nlral  nerrous  system  to  the  several  tissues:  lluit  in  to  say,  the 
iwaer  ia  ninde  up  of  ssiuory  fibres,  or,  i since  the  imnuhvs  |wwing  along 
Aon  m  the  ceolral  systom  may  give  rise  to  effects  otlier  tlian  iwnMitions) 
tfittmi  Abree,  while  the  Utter  ia  made  up  of  tiiotor,  or  (.since  the  impulsiw 
fnisf  along  them  from  the  central  nervous  system  may  produoe  eflocts 
■  than  movements),  (ffemit  6br«s.  Tlie  nerve  trunk  N  is  oonsciitcntly 
pnl  nerve  oorapoaed  of  aSerent  and  efferent  fibre;^ 
I  far  the  greater  |Murt  of  this  mixed  nerve,  dividing  into  various  brnuchet, 
»dNirifaated  i  .V)  to  the  skin  nud  the  skeletal  luiiAcles,  some  of  the  librtt 
'■nier)  ending  in  muscular  tibres  (JIf ).  others  (iteiiaory)  ending  in  cpithrlial 
■*IU($)  mnitected  with  the  ukin,  which  we  shall  oanaMer  hereailer  under 


[VW.  M.— l^KH  fKttnn  OR  Ham  or  mc  CiixknHi;ii  '>i>  Cmu»ki.i.i,-)i,  unit  «r  twk  l^w* 
Vjimui  «l^  «iori.L»  obiahuat*.  *v«)  tu«  Asntuon  Bir»rjict  or  tue  t-rixii  Cnu-.  to  Siio* 
Tia  UoDK  iw  Omii>iii  or  tiik  Siixti,  NcKris  frov  iiir.  srtmi.  i'okb.  tsn  the  ciukiii.  Xrrt 
rMW  mil  RixKoirTili;  DntiW,  n,  .i;  nrrbnil  Iit'iiiliphnn  ;  A,  rlHht  halfof  cpnhrll'un:  n.m^lallii 
tXAtntlfm:  atomhli  li>  trniiirrnciibllc  mam.  Ihc  poni  VanilU  ;  r.  r*.  (he  uplnikt  ounl.  (Iiuvliigii* 
cnrloal  ini)  IdnitxT  vnlBtitiuiiiUi,  knd  ll*i>jliiU'd  MniJtMtiuiu ; «.  (lip  lauditniulnii,  fdnntil  ligr  (ha 
«ltiiilist«l  nvuof  Ihu  limbuuid  mtnl  oamii  1  loa.  lb*  Kvnrnl  cniilnl  ncrvn .  artiln^  from  tbe 
hue  tl  Uic  bnilii  xnil  the  ulilc*  of  lh«  niedull*  oblFini^u.  Bulou  itioc.  on  cACb  «l<k.  arc  Ibc  roau 
er  Urifin*  oT  iHi;  ^v^n^l  ni*nrcv,  vTn  k'Rl. 'IrTwl  LuieiTeit.  wa'l  Mi^t^l  In  «nn^  ot  IbOHv  lliv  <lntihl« 
icM  «i>  be  iBtn,  >nil  (Iw  nvllliiR  nr  eiidhIIkii  on  tlii>  poalr-rlmr  mn.  n,  «,  ine  ■1III1I17  or  bnohtel 
Ilium.  Ibtnipd  bji  the  ftnii  luuvt  ivtvicnl  and  Dm  ilonoJ  iiilaiil  nerroi ;  L  Ihc  liunlaT  |ilai** :  ^  itw 
Mwml  ptcxtH.  (ImnM  br  (hiUut  lumbar  nrrv*  ami  llnl  fmir  lari^  hutyot  :  I,  ■hiiuta  idtrVoTlb* 
•IwiUiar  ih«  cord  oat  ap««i,UHl  Willi  UBfMtloo  or  tht  tiBftincnisin  ilflnUralai-iiD  wlil«U  fuiiwm 


rXBAL  rSATURSS  OP   NKBVODS  TISSL'KS.  161 

tk^iMnwofrnworycpilfarliml  cvlU.  whiknihcm,  .V,  alter iltviding  into  minul« 
UmiAm  Attd  Armiag  tilexuMV  ri><),  in  unys  aot  jrct  detiniUily  <)ct«rriiiDe<l, 
to  IMIM>  ■■ccitled  witb  Ibr  skin  mtul  >kv!piii)  miiMln.  &[orp)iol(ig»t«  ili*- 
tingviili  tbo  pBfts  which  ^  to  tunn  the  skin,  skclctiil  mutclra,  <-tc.,  n»  nturi'ifu, 
fno  lite  W&iimAniV  |iim»  which  pi  to  form  the  vitcvra.  Wr  mny,  nccurd- 
h^j.  atll  Utia  nuiin  pan  of  thi-  spinnl  n«rve  the  toauUie  division  <if  the 


Sw*  <lA«r  ih?  miscd  n«rve  .V  leaves  tiie  spinnl  canal  it  gWee  nff  n  small 
InaA  r,  which  under  ihe  name  of  (white)  ramtu  mnimHuiVvjiiJ'.  joins  one 
(f  B longiludinal  series  of  yiiny/iVi  t^i  cunsiiicuitus  in  the  tboms  lu  the  inaio 
tmfilktiie  chain.  This  Uranch  is  iltstiiied  to  supply  the  viscera,  and  raij;bt, 
iliRftK  be  called  tite  »pt<tnek»ie  divisiDii  of  the  spinal  nerve.  We  may  say 
M  ton,  witbout  eotering  into  dvtails,  that  the  whole  of  the  eytnpathetJo 
mliB,  with  its  gannlia  plucujwo,  aiid  nvrvee,  ut  to  be  rej^rded  as  a  develop- 
MM  or  vipAiuion  of  the  vi«c«ral  or  splauchnte  diviaioi»  of  certain  spinal 
Btms.  By  Di«uiM  of  thi«  sv*t«ni  splaachnic  fibm  from  the  central  rwrvoua 
tnCm  «n  distributed  tu  tbe  tuaucs  of  tb«  viw^ra.  *)tne  of  them  <>ii  tli«ir 
Mj  pasriuc  tbraagb  swoudary  ganglia  «,  and,  it  niny  bi-.  l^rtinrv  gutiglia. 
IWnsj*.  bowerer.as  wesliall  see,  orrlain  ncrVi^  or  fibnwwhirh  do  not  run 
la  ikr  aympnthflic  syMf oi,  aiwl  y«-t  itn>  ilistribiilisl  (o  tbe  vi.-ii-tira  and  an 
'iplaMDQle"  in  naturf'.  We  cnnnut,  [brrvfore,  iikc  tb«  word  •yni]ialh«lio 
l*4nMI«  all  the  Kbn>  which  nrv  sphinchnic  in  nature.  On  the  othiT  hand, 
lla~i|)4anoliiii<-  iM.-r%'«i"of  tli«  anatomist  form  n  part  only  of  tfauoidanchnic 
ifMn  in  ibv  idiovo  mow,  ihc  t^rm  thus  used  is  limiic'l  to  partiruhtr  nvrres 
«  Ibtiplanchnio  mteiii  distrihutcil  to  the  nlHlonteii :  and  (he  double  use  of 
tkiffin  splanchnic  might  lead  to  confusion.  The  dilfiuullv  may,  ]iorhn(«, 
bntidea  by  call in^  the  splanchnic  nerrca  of  the  anatomist  "  abdominal 
^IsodiBte."  The  majority  of  these  splancbnic  libra  seem  to  be  efferent  in 
nsuir.  i^arrii-inf;  tmpiilaeb  front  lbs  central  nerroufl  system  to  the  tissues, 
aaMcitdin];  in  plain  muscular  fibrw(mr  others  in  other  ways  (x);  but  some 
rflhaSbres  are  nllereni  and  ciinvey  impul»««  from  tbe  viscera  to  the  central 
■VTHs  iyst«U),  and  it  it  probable  thai  sotne  ofiheae  begin  or  end  in  epitbe- 
U  ndU  of  tltc  visoem  it). 

V«  shall  have  occnsi'Xi  in  tli«  nest  chapter  to  speak  uf  nerves  which 
pWB  ibe  bI'VHiveasels  of  tli4'  Wly,  the  aCHMlled  va»omi>tor  iicrvm.  A  eor- 
(i^diai  iif  th«4',  namely,  ibe  Ktw-MHS(rMitor  ncrvtv  or  fibre*  are  branches 
<f  ibesplanchniiT  division*  oflho  cvrebm  Kpinnl  nerren,  aiul.iia  we  shall  see, 
At  Taii>.OOQStri('tor  nervm  nf  |h<'  «ikel<Hnl  muscles,  okin,  aod  Other  part*  nip- 
"""'  bgrWBUitic  nervw,  after  nmuingfor  winn-  distnncw  in  the  splnndinic 
'm  ( I'),  turn  uide  (r.  r  and  r.  m)  and  join  the  eomatic  division,  tbe 
I  qf  which  tlu-v  necompanvnn  their  way  to  the  Usfuea  whose  bloodvoosels 

iiO*«y  »Mr-  ■ 

SSMS    J.  ■innnvrMfKUtii'ilicnnthihrcnrd,  iDihow  Um  fffniiorihspareKBBasrbNBK  la 

t»mi0rttti  otiUr  ■atuBiKT    /r.«(iDii»airikiiicp&n>.Biul>i»iiwnwnitaaneo(ihs<asl:Bad 
ftUMtr  'iiir  n«uuf  «  [«lre<  t[4iial  nccrw  jprlaftng  Ihon  utiMn  [ 

fHC  '  mi  Nimvtxir  *  ■D-nnnornn  (Mhal  Vuaa,    ifttmj,  irwhliQiiwiMr 

'qftal  camt  J  tiiuno*. /'faialarlamnl  tiRBnaniHi  oa  ilut  poiwnar  n»l.  .V  « bolt  tiem,  V 
*B*l  mm*  fTCfM,  «>4loalii  W  (krlttsl  ui  aiuuiUc  iuukIv,  .VuiiuUcMiiiKiry  tail  o  lurltuie,  Xln 
^t^V*-  r  tliw d  arm  mhlM  ami  Runnuinlcknii  janliis  UiasmiiBlton  of  lh«  tnotaUiaae 
•IMl,*arf  poaam  so  •*  I"  Id  •Uffil]'  Uir  inoreriliUat  pkOtUi'D  9.  Urm  ■■  F'lo  Um  ptrtptMnl 
pai>a  V  wHt  mill*  in  n  itlsathnic  iuumIcl  f  irtawtiiilc  wauy  tnU  or  nrlboc,  <  oUior  pcwtbls 
FS^aSi  from  1  !•  flTm  nA  Ihr  (nrbfiu  nm«  r  r  <i[n)r  luiiut  iiiwiiiialiaBil  wtilfib 
I  toctaanl  inHiiKl  tlMtplniil  ninl.ii4>]  pinlyniiHHi.  ■>.  in  otmnetdon  with  tM«|4nal 
\.mtaj/t*j  (■aiin>ilw<otiaMnclu(>atraii>ilie  midcI«  (•■'ja^bUadTtaalt  In  oauln  |iu1i^  toi 
.talS*  ll«li>.  :b.ta««rnir*l*Mili.-(taln  anlilnc  ihii  fUcUa  a(  >b«  SSrlM  1  Thn  linnl- 
•  ((IksetksrnMtOTMUas  nnn>  i.*  c' an  not sbovB, 

11 


(IRKERAt    PKAT^RKS   or    ITEftrOCS  TIflflPKS. 

We  Imvv  iMwii  (§  6H)  thai  a  uerve  ),">■>■)!  1"  »  'ouvcle  b  cotDpoacd  ofneiTe- 
fihrei,  chietl}'  m«diillated,  snmc,  liowever.  Iieinj:  non-iii6cliillaM(],  bMiai) 
toj^tber  hf  cnunei-iive  tiaaiie.  The  same  deecriplion  faolds  vooti  tor  llie 
whale  Boiuatic  divlsioti  >if  eacti  of  tbe  sjunal  nerves.  The  «piancDi)ic  <livisioii 
also  consists  of  luedulliileil  and  noti-medullaieil  libren  Unuml  lojtelbcr  by  ma- 
nectivc  tiaoufr,  bul  in  it  tbe  noa-Rie<Iu  Hated  Rbra^  pre|>onderate,  Mime  bmncbe* 
a|i|ienriflg  to  oontaiii  banllv  auy  tuedullaied  fibres  at  all.  Tbe  ouu  nie>lul- 
laled  Hbrea  which  are  found  in  the  soniatie  divisioo  appear  lo  bo  tibn-K  wbich 
have  joiuf d  that  diviHitin  fmiii  thct  splaDcbme  divUiou.  Su  pfimiiKiit  arr 
iioii-niedtiMiiled  filire*  in  nplanchiiic  nerve*  ami  lieiice  in  the  Nvnipubetic 
Nyalem  that  tbi-v  nrt;  »iiniiirinift>  called  9yni|iutbetic  tlbru. 

W«  hn\f.  Mild  tbuL  ibi*  axiii  cylinder,  whether  (if  a  medulla  led  or  dod- 
medullaied  fibre,  in  to  )»•  ci>iK-<itlvred  ii»  a  lung  drawn-odt  pnM.'CNi  uf  ■  neire 
i-oll.  Nerve  crIU  are  liiiind  in  thn^  Diain  *ittiation».  1.  In  the  i^-nlral  dot- 
volt*  «yi>toni,  tbn  brain,  anil  Kpiiml  curd.  'J.  In  the  wvcral  ganglin  placed 
along  the  counN-  of  the  ncrvcti,  both  the  spinal  {pmglia,  and  the  ganglia  of 
ihosnlfliichiiic  oraymptitliriir  "y^ti-ni.  'i.  At  the  Icnninntionii  nf  nrr\'»  in 
certain  tiffiun.  .Snme  of  tbcMir  bitter  nrcr  lo  hv-  rvgardcd  a»  ^ninll,  more  or 
IcH  terminal,  eonglia,  and  similar  minute  ^uglia  coDiti»ling  uf  Ino  or  three 
cells  only  arc  found  i'rciiucntly  aloo^  the  ci>ur»?  of  x planciinic  norvca  and 
occasionally  along  the  coureo  of  spinal  nvr^'es;  Mich  celU  really,  tbereforo, 
bcloDg  to  the  wcnnd  grnup.  Rut  be»id«»  tbi«,  in  rertuio  vitnaliona.  as  ibr 
inelance  in  certain  »rgnn«  of  the  skin,  and  in  the  organ*  of  special  eeoee. 
nerves,  j^nerally  allercnt  or  sensory  in  nature,  either  actually  end  in,  or  at 
tbeir  termination  ar«  connected  with,  cells  which  appear  lo  bo  of  a  nerroua 
nature;  such  cells  form  a  distinct  calei^ory  by  themselves. 

Uence  nlaun  its  whole  course  a  nen-e  consists  esclnsively  of  nerve  fibna 
(and  the  ooniicctive  liMue  lupporling  them},  except  in  tbe  central  nerrout 
syiten  from  which  it  vprJngn  m  tbe  ganglia,  great  ajul  amall,  through  wlucfa 
il  puttt,  or  which  an;  alta<'bi-d  lo  il  at  one  part  or  another  of  ita  oouiw,  io 
boib  of  which  sitoiUinns  nerve  crll»  are  found,  and  at  ita  terniiuatioii  wbcn- 
ib  fibres  niav  cod  in  nerve  celli>. 


Jjlipniiiiiiii  1 1  niiiiii  I  Till MiDiii.Knr  i(;ji>iiiiui(OMiii:  fivni-ioR  ItKiT  nr  0»K  or  ni« 

a,  tum*  Mot  fntvniig  thv  a>ngtloii  ^  i,  libra  lisilnu  llie  NUDitUon  lojoln  Ibtnoiud  ((tnal  Ddrrv, 
<HH<i»»r<lrn  llimrii  ir»i  f  ihi- (snctloii ;  •(.  |inni.i1|«l  i|nnip,if  nrrvDCVlli,  wttti  6bim fi^in ikua 
ft«B  *iiKiii|pi  III"  mIK  jirobiility  tu  iinli«  Ihv  loitutiii'IIn*nr  roiiiMnR  (irrrc  ninM  br  T-^hapt^ 
JOMtlnlu.] 

Tlie  features  of  these  nerve  cells  diHer  in  these  several  siluations.     T)>e 
eharacters  of  the  terminal  cell»  wbii-h,  an  we  have  »«id,  are  chicDy  evaaory. 


|Pra.4;, 


GBXKftAL    FKATCRES    Of    SKHVOVS   TlSSVItS. 

idI  ibr  Mmctiir«  of  (he  bniin  nml  npiiml  eon],  w<>  •hall  sludr  in  detail  Inter 
!«.  W«  nwy  hero  ronlinv  <Hir  lUtemioii  to  ihr  norvo  »IU  of  the  }rnii<jlii> 
■■I  ti Minitt  of  tho  bninil  fi'Uiiri.ii  <>f  llic  ncrv<7  colU  of  the  epinnl  cx>ni. 

)tT.  Sftiitiil  ijaHi/lia.  Whcn  ■  longiliiilinal  skIJod  of  ii  »|>innl  gaii^'lioii 
Iltuaiit»-i)  uniivr  n  l»w  iM)w«r,  tl»c  libra  nf  lh«  {lostorior  root  ns  llicy  tint«r 
tkpn^lion  «rc  ohm-rvnl  ta  sprond  out  and  {inn  batween  r«lativvly  \aTgK 
nl  nHMpi<^uiiti>>ty  titiuknlcd  c«ll>,  which  an-  to  a  large  extent  arrnuKifl  iit 
piM>.  «oiii«nliBl  nll4T  (he  fnaliioa  of  a  bunrb  nf  grapes.  [Fijt.  4<>  j  These 
wt  tW  flcrTf  cisIIb;  tUry  h«v«  frv^giiputly  ■  diameter  of  abuiic  IIM)^,  I>ut 
MT  bt  fiill  lafK^r  or  may  be  much  ininlkr.  In  a  inuuvvrse  ■evltiut  it  will 
WvlMTntil  that  A  lnri;i'  compact  maas  of  ihne  lvIIs  liea  on  the  outer  ride  of 
AfgUflion,  nii>)  that  the  raoeiDoec  ^roupa  on  the  iiiiter  ride  ar«  smaller.  A 
'ly  of  (woiwctive  tinae  ratrryiiiR  bloodreaseb  and  lympbntic*  run* 
Uie  pntipa,  UiA  paauDs  iiit<i  each  K/oup  runa  beinevn  the  oclln  and 
and  a  thick  wrapping  oTeooiWctiva  tuaue  cmtiuutMU  with  tlie  sbcmtta 
lb«  u«rve  fcurrvutidi  iiiid  fornu  a  aheath  for  the  wboli?  piiiBlion. 
Each  i>f  the  nerve  celk — (.-nDxliouic  celk,  aa  they  arc  culled — «xainin<Kl 
r  a  hi|;h«r  jHiwer,  ei(J>er  after  having  been  laolatecl  or  in  an  ttde(|Uat«ly 
■ad  nepsrad  aectioD,  will  presetii  tbo  fullovring  fieatuna : 
eell  ooniMtSof  a  kH  hudtf  nbich  is,  normally,  poorahniH-d  (Fig.  I7], 
a  bfMul  end  iu  which  U  ]ilucci]  tlic  nucleu*.  and  a  narrow  «>nd  whiCB 
out  itiKi  a  (udk,  and  is  eventually  cuu- 
lined  oii  a*  a  nrrve  libre.  The  xiibHtaoee  of 
Af  cdl  hotly  in  of  Ibc  kiwi  uhicb  we  call 
MygnuiaUr  protoplum;  Mmirtimea  there 
>  w  ap^raniw  of  fibrillatiun.  the  fibrillA 

niii  varioUB  riirocliotu  in  the  body  of 
I  and  beiitg  gathered  together  in  a 
kapladitwl  dirvction  in  the  stalk.  Some- 
tioM  iIm!  cell  body  immediately  aro4ind  the 
Mcltu*  api>ears  of  a  different  i^'rain  fntm  that 
MUtr  tlHt  stalk,  and  n<>t  untrequently  oenr 
At  gueleOB  !■  an  a|tK"'Ki't*^i>  cf  discrete  pig- 
Mat  yranules  imbedded  la  tJie  protoplasm. 

tW  ntitJevi.  like  the  nuclei  of  nearly  all 
■mealli.ia  brKcand  contpicuous,  and  when 
ittoomal  eumliiioa  is  remarkably  clear  and 
nAirtirr',  though  it  appears  to  consist  like 
<(Wr  BDclei  uf  a  nuclear  membrane  aii<l  nei- 
^rt  and  Dudcar  jntervtiliul  material.  Kven 
am  nnupiciiotis,  perliapa,  is  a  very  large 
H>rriml.  liigbly  n'fnictive  nveifoliu:  occaaioaally  more  than  one  atieleoliu 
itpraaat. 

i^miODdiitg  tk»  ocU  body  is  a  dtttinct  tUfnlh  or  eit/tnik  oontiatin^  of  a 
■nKaurnt.  hyaline,  or  faintly  fibrillatcd  nwnibnine,  lined  on  (be  Inude  by 
ia»  Miferar  by  two  layers  ot  flat,  |Milygunnl,  niiclmK^l  epitMioid  cella  or 
Mub;  that  is  to  aay,  ctlla  whieh  rriNiniliU'  e|>ith<;lium  i-eli>,  bnt  differ  not 
•aljia  being cilrem«ly  llnlieocH.  buialsoin  the  evil  IhkIv  Uiini;  Iranoformed 
h*  untinarr  graiHilar  protoplasm  into  n  anav  tntmparetil  dilferciitiiited 
WWrial.  In  ataim.ll  ii|>e<-imen8  the  niielei  of  tlti-sc  plnt>-e  are  very  cmopicu- 
<aa  Undtr  normal  condition:!  this  •hciith  i^  in  chwe  (.-ontaet  with  the  wlinle 
Wj  of  the  cell,  but  in  harth'nixl  nnd  prvparod  specimens  the  ivll  body  is 
•wrtmia  iM'U  shrunk  awiiy  from  the  'heath,  leaving  a  apac*  between  them. 
OHHiaaally  till'  cell  liody  while  remaining  at(a<-hed  to  ttlfllbeatb  at  three  or 
tmot  mora  potuta  is  reiraeted  elsewhere,  and  accordingly  assumes  a  more 


•rtsiimist  or  *  PvaiTOioi  oakhiJ' 

(ixn:  Kkkvs  Ctu, 
A,u«(inlln(UB«le:  B.soMnUac 
(DAranU.) 


0E:«ERAI.   riATUBBS  of   XKRTOCS  TIS81-SS. 


or  lev  Uellate  form :  but  ihU  aitiBcml  ooudilion  must  not  be  oonfouixled 
with  the  Datuml  branched  fi>riu  which,  as  we  tliali  aee,  other  kinds  of  nerve 
oell*  iMwewL 

Wnen  >  section  is  made  through  a  hardened  ganglion,  tlie  plane  of  the 
MCtion  psMiffi  ihroiifch  the  stallci  nf  few  only  of  the  ceils,  ajxl  that  rareljr  for 
nnr  grcnt  distance  aJooj;  tlie  stalk,  since  in  the  oase  of  many  of  the  celb  the 
«t«1lc  is  luoro  or  less  curved  and  ci>nsc>|uetilty  runs  nut  of  the  plane  of  sec- 
tion ;  but  ill  properly  iwlatuil  cell*  we  tun  itee  that  in  aianv  eases,  and  we 
liavo  rensoOM  tu  bdiovc  that  in  all  caat^  thi-  stalk  of  the  oell  b,  as  vre  liare 
nid,  cnnttiiiivd  on  into  ii  ntirve  fibre.  As  the  cell  body  narrows  ioto  tlie 
ttalk  scvcrul  nuclei  niiike  tlicir  npiMmiraDce,  lodged  on  it;  these  nre.  small 
emnulnr  niictd,  wholly  unlike  the  nucleus  of  the  cell  body  itM'lf,  and  more 
like,  ihoiii'h  not  (|iiilij  lik<',  the  nuclei  of  the  neurilemma  of  ■  m-rve.  Ther 
are  probnoly  of  tbo  «imc  nature  as  the  Inttcr;  nml,  indood.  ii*  wi-  trace  ihc 
luirrowiiig  stalk  <lowiivriir(I  n  fine  ddiwii*-  shwith.  which,  if  jin^rnt.  is  at 
least  not  oIivIook  over  (h«  cell  body,  makes  ilii  iipixTiirnncr,  nnil  n  little  further 
on,  between  this  ^hcalli.  which  i#  now  deiirly  n  m'uritcmma,  and  the  Ftalk  of 
the  cell  body,  which  hns  by  this  time  become  a  cylinder  of  unifomi  width 
and  is  now  obviously  an  axis-cylinder,  n  larcr  of  medulla,  very  line  at  ti»t, 
but  rapidly  thickening,  is  established.  Tlie  stalk  of  the  nerve  cell  thus 
becoraeb  an  ordinary  racdnllated  nerve  fibre.  The  sheath  of  the  cell  is  con* 
tintied  also  on  to  the  nerve  fibre,  uot  as  was  once  thought  ne  the  neurilonnna. 
but  as  that  special  sheath  of  connective  (isei'.t<  »f  which  we  have  already 
auoken  (§(>!<)  as  Uenl6*e  sheath,  and  which  ultimntely  becomes  fused  with 
tiie  connective  tissue  of  the  nerve. 

At  some  variable  distance  from  the  oell  l]ie  nen,'e  fibre  bears  the  firat 
node,  and  either  at  this  or  some  early  sucoeedinji  node  the  fibre  divides  into 
two;  iM  we  have  Mxn,  diviaion  of  a  medullated  nerve  6bre  alwavn  takca 
place  at  a  node.  The  two  diviiii<,itis  thiis  arising  run  in  opposite  diret-'lions, 
fonning  in  this  way  a  T-piccc:  and  whilv  one  division  runs  in  one  direction 
toward  ihc  iMWtcrior  root,  tin-  lUlior  runs  in  an  oppnsite  direction  toiranl  the 
nerve  trunk.  The  nerve  cell  is  ihtw.  ns  it  werv,  u  «ide  picc«  Bllttclie<l  to  a 
fibre  passing  through  the  ganglion  on  its  wtiy  from  the  posterior  root  to  the 
nerve  trunk.  It  cannot  be  said  that  in  any  one  f^in^lion  this  connection  has 
been  traced  in  the  case  of  every  nerve  cell  of  clie  ganglion ;  hut  thv  more 
care  w  tHkeii,  and  the  mora  successful  the  preparation,  the  greater  is  the 
number  of  cells  which  may  be  isolnt«l  with  their  r(«j>ective  T-picces ;  so 
that  we  may  conclude  that,  normally,  every  coll  of  a  ganglion  is  connoctod 
on  the  one  £and  with  a  fibre  of  the  posterior  root,  and  on  the  other  hand 
with  a  fibre  of  the  nerve  trunk.  We  have  reasons  further  to  believe  that 
every  fibre  of  the  posterior  root  in  passing  through  the  ganglion  on  its  way  to 
the  mUed  nerve  trunk  is  thus  connected  with  a  nerve  cell ;  but  this  has  heen 
caUed  in  ((uesttoa.  In  certain  animal" — for  instance,  certain  fishes — the  cells 
of  the  spinal  );anglia  are  not  pearshaped.  but  oval  or  fusiform,  and  each 
narrow  end  ia  prolouj^d  into  a  nerve  hbre,  one  end  thus  being  connected 
with  the  puelenur  root  and  the  other  with  the  nerve  trunk.  In  such  a  traae 
the  nerve  cell  in  simply  a  liirtct  i-n  large  men  t  of  the  axis-cylinder,  with  a 
nucleus  placed  in  the  eiiiarjcenient.  The  nerve  cells  above  descrilieil  are 
simihtr  eolartfemcnts,  also  hearing  nuclei,  placed  not  directly  in  tlie  courae 
of  the  axis-eylinder,  but  on  nnc  side,  and  connected  with  the  axis-cylinder 
by  the  croM-]>ie(«  of  the  T-i)i<-ce.  Hence  the  ordinary  ganglion  cell  is 
sjwken  of  u*  being  unipolar,  tno»e  of  fishes  being  culle<l  bipolar.     [Pig.  -48.] 

In  examining  spinal  ganglia  celU  are  sometimes  found  which  bear  no  trace 
of  any  pructw  connecting  them  with  a  nerve  libro.  Bucb  cells  are  spoken 
of  as  npolnr.     It  is  possible  that  such  a  cell  may  W  a  young  ncl)  whicli  has 


trio.nL 


VtHUCB  rOUU  at  GUMLMmC  VMBTL* 

k  »  M«>  MUsir  r«IK  <r1ik  ilNlr  pfDloovulm*.  (MtB  Um  Mltalw  honi  or  ih«  tnv  iDiilM  or  iba 
•IMd  iMl .  r.  tmw  nil  altli  M*  toii(i«ii«4  Wn.  IhMi  (In  uwrionitiBl*  <tf  tb*  ftoUl  iikI  auditor 
MtB  In  Om  ■—nn  aiidnniliw  [uutiua  of  the  ox ;  a.  cell  vail;  t.cell  ecntdui;  r,  iilKinmiai  il, 
■AMir.  pnlsai^uo*  lbrnila«  iW  tbwib  af  Ibt  Dbr*:  /.  nam  ilbrv:  a,  ntrrv  nil  rmm  th» 
iriMMa  »wml>«>  <if  ■■■  :  r.  laatlar  fell  ftnin  the  iplnal  ronl :  macnlllal  UO  lUuntun. 

iM.  Tbegiuig)i«<irth«  'p/'inrAnir  Bystcm,  liko  the  «{>inal  KftDel>><  ronaiat 
*rienre«du  Uid  Hbm  imIwHdci)  in  connpctlvo  tiwiit-,  irbicb.liowever,  m 
«(>kaWTUl<l  len  compftii  tiatur«  in  lh<!iii  tUitn  in  the  Hpiial  KtmsUa.  As 
kr ■  the  duincten  of  tbeir  nuclei,  ilie  nMureof  thoir  cell  siil>atance.  and 
AtpaKSMioD  of  B  sli«ath  ur«  coticenie<l.  what  haa  been  snid  concemiug  the 
MtTC  orila  of  apioal  ^^n^lia  holds,  in  genernl.  t[ood  for  those  of  splaiiehuie 
(iwlbi:  »nd,  iiMJeed.  in  certain  Kiiuglia  nf  the  B[ilaiichnie  >v»t«tn  connected 
Mo  the  rranial  nerves  the  nerve  cells  Atipnar  to  be  whollv  like  tlwwc  of 
fiwU  i^atiglia.  In  most  splniu-hnic  f^iin^lia,  howe\'er,  in  t^oK  which  nre 
piMnliT  allied  lympiilhetic  i^aiix'Hii,  two  iinjior- 
(■t  dHfennca  may  be  obM-rvod  l)«lwe«D  whnt 
n  may  call  the  <-tinraotcri8tic  iicrv*  cell  of  the 
^Ineknic  ganj^ion  and  the  cell  of  (be  ipiDal 

u  th«  lirsi  plaw.  while  tbt-  nrrvc  cell  of  the 
^inal  gangliii  hu  one  proocM  only,  the  ncnrc 
fill  vt  th4>  KplnncUnic  gnn^lin  may  bnre,  and 
^inaptly  ha>,  tw«,  ihrre,  or  even  fonr  or  tire 
it  ii  a  muitifojar  rell.  [Fig.  49.] 
iIm  viwfind  pUoi'.  while  these  proccBBtfl  of 
•pUnchnti-  ei"'?""')  cell  arc  continued  uti  ns 
libraw,  aa  U  tiu-  nnglc  process  of  the  Bpinnl 
mil.  ihri  nerve  nbrea  n  formed  nre,  iu 
of  mi»t  of  tlic  proceosea  of  a  cell,  and 
MWtinim  in  the  case  of  all  the  ptoeMMS,  Don- 
BMUillatM)  librr«,  nnd  remain  non-meditUkled  as 
hr  af  the^  can  be  truced.  In  aunie  iiiHtailMi  one  procMi  beconwt  at  a  little 
teanM  miin  (he  cell  a  tnedollated  Hhre,  while  the  other  proceaea  become 
■■hOMlu Hated  6brea :  and  we  nre  led  to  Iwl'un'e  tlm(  in  this  case  the  medul- 
filtre  is  proceeding  fo  the  <^ell  on  ii«  way  from  llie  central  nen'otu 


SnujTB    !lEaVE   CUX,    tMM 
TKK     NLELKlk    C^VIO*    CXiMlrV 

ll^>^^nlu•l  Vimlvub  Oou'umi 
iir  A  Form  or  8ii  Momim, 
i»«cnllM<aLI    Aftei  Buu.) 


106 


OENKRAL    FEATURES   OF    NERVOUS   TIS8t?EB. 


mtcm,  and  lluit  the  Don-niedultated  librw  are  proceedini;  Jrom  ih«  cell ' 
taeir  way  lo  m»re  [leripherally  [ilaced  parts ;  ilie  nerve  cell  seems  lo  »rve  u 
II  crntra  for  the  diviniun  of  n«rve  fibres,  and  also  fur  the  cIibd]^  fVom  ni«dul- 
Intcd  In  DDii-UMfdu Hated  fibres. 

[r  ci)iiiH.'i|tK'Uc-e  of  iU  tbus  poswwiug  mvotaI  procesMS.  the  splauchnic 
gnnclion  <-cM  !:>  more  or  lew  irre^lar  and  oft«D  alar-like  in  form,  in  otitrMl 
ro  tbr  pi'iir  Khu|ie  nf  tb«  »i>iniil  gangliun  cell.  But  iu  cN-rutin  .situation*  in 
cerUiin  auimnl* — lor  iiiatiintv,  in  (he  fVu^' — iti  many  of  lli<-  );angliu  nf  the 
abdomm.  uid  in  thi^  umiill  nui};lia  iu  llie  heart,  puar-;*hapfM)  i>pliini-hn>c 
ganglion  cclli^  arc  nint  wilb.  In  mich  euees  the  nucleated  shwilh  w  ilintinrtlr 
ncar-tt]i&rM.'i)  iirbnllodd-ihniHMl.aml  thi'  liir^ir  c>niiH|>ini'>ii»  nni'li'ii:!  i*  pla<»H,  n« 
ID  llic  Bpiiifil  gntigllon  ftll,  mar  ihe  hnwil  i-nd.  Inn  ih«  cell  Mib«it«nc«  of  tbe 
cell  is  gathered  nt  thi-  «tnlk,  n»t  into  ii  t>iii-_di-  librc.  hut  into  two  fibres,  one 
of  wliidi  in  etrnighl  and  tbu  olfat-r  twiwU-'l  K|)irally  round  tbe  utrnigbl  oae. 
T\w  tiro  libm  run  for  somr  di»tanw  tojnitlier  in  the  «ann!  funnel -shaped  pro- 
longation of  the  nucleated  sbealh  of  tin;  cell,  hiil  eventiiaiK  separate,  each 
fibre  acf|uiring  a  »henth  (sheath  of  Henle)  of  itn  own.  fienerally,  if  not 
always,  one  Hbre,  usuiilly  ibe  straight  one,  becnniM  a  mediillated  fibre,  while 
the  other,  usually  the  twisted  or  spiral  one,  i*  continued  as  a  uon-medn Hated 
libre.  While  within  the  common  nucleated  abeath  both  fibres,  eapedally  tbe 
Hpiral  one,  liear  nuclei  of  the  snme  cburacteras  those  seen  iu  a  oorrespouding 
riiluation  in  the  spinal  ganglion  cell.  It  hiis  been  uiaintatnetl  that  the  atraighl 
mill  npiral  libros  take  orimn  from  diHi^rent  part*  of  the  nerve  cell,  but  UtU 
bnn  not  been  definitely  proved. 

In  the  wntlla  of  the  iniestiiie,  in  connection  with  splanchnic  nerrev,  are 
found  [K^culiar  nerve  cells  fumiiiig  what  are  known  as  the  plexuses  of  Meias- 
ncr  and  Autrbach,  but  ue  shall  postpone  for  llie  present  any  dcacription  of 
thrac  or  of  other  peculiar  aplanchnii.-  cells. 

§  99.  In  the  eerUral  n«rvou»  mjfti-nt  nerve  celln  are  fotind  in  the  so-called 
jroji  matttr  only,  tbuy  mtf  alwont  from  the  while  tnatfrr.  In  iho  gray  maUer 
of  tlte  spinal  cord,  in  tbe  pnrln  .-iiiokon  of  ns  the  niilcrior  comua,  wc  meet 
with  remarkable  nerve  oclln  of  the  following  cliarucier;.  Th«  oelU  are  large, 
varying  in  diameter  from  oO^  to  140/'.  nnJcach  coiiai»t8  of  a  cell  body  sur- 
rcHiiiding  a  large  conspicuous  rcfraclivu  nucleus,  in  which  is  placed  an  even 
still  more  conspicuous  nucleolus.  The  nucleus  resembles  the  nuclei  of  the 
ganglion  cells  already  deHcribnl,  and  tJie  cell  body,  like  the  cell  body  of  tbe 
ganglioo  cells,  is  composed  of  finely  granular  piotoplasni.  oflen  fibrillated, 
though  generally  obscurely  so;  frequently  a  yellowish-brown  pigmi^ut  is 
depiwitfJ  in  a  jiart  of  tbe  eell  body  not  far  fn>m  the  nucleua.  Tbe  cell  bodr 
is  prnlonged  wimetimes  into  two  or  three  only,  but  generally  into  several 
procewoi,  which  appear  more  dislinctly  librlllat^l  than  the  more  oentral 
partM  of  ihi-  ei.*ll  bmly.  These  proceseeH  ar«  of  iui>  kinds.  One  proocia,  and. 
apparently,  "Ue  only,  hut  in  tJie  case  of  tbe  cells  nf  thi-  anterior  curuti, 
always  one,  i»  prolnugud  a^  a  thin  nnbranched  band,  which  n<liiiiiH  a  fairly 
uniform  dinmcle.r  fur  a  <-i)n9iderable  dlstaiioe  from  tht!  ci^ll,  and  when  suc- 
oessfully  traced  is  found  Hooner  or  later  to  RCjuire  a  nKilulln  and  to  become 
the  axis-cylinder  of  a  ncrv-e  fibre;  tbe  proccMce  which  ibii*  pan  out  from 
the  gray  matter  of  the  anterior  curnu  through  the  while  mnttor  form  the 
anterior  rools  of  the  spinal  nerve.  Such  a  pruccM  ix  uccordingly  called  the 
run»^liiuii-r  proKJif.  The  other  pmcowft*  of  the  cril  rapidly  branch,  and  so 
divide  IdIo  very  delicate  tilanicnts  which  are  soon  lost  lo  view  iu  tbe  aub- 
•laBee  of  the  gray  nialler.  Indeed,  the  gray  matter  is  parlly  made  up  of  a 
plexus  uf  delicate  tiiaments  arising,  on  the  one  hand,  from  thedivinoD  of 
procCMSS  of  tbe  nerve  cells,  and  on  the  other,  from  the  division  of  ifae  axis- 
vylioden  of  fibree  running  in  ilie  gray  matter. 


dk 


OKKBRAL  riATL'RBS  OP  XCRVOt'S  TISSUES. 


167 


TWceltt  ■  Dfit  HirroiiniM  like  the  ganglii>ii  cell  bj^aHislinct  sheath.  Aa 
*r  ifcall  mr  laur  on.  nhile  tnatint;  in  detail  of  the  ceiitnil  nervous  syHtem, 
kU  iki  nvn'oup  rlcnirnw  of  chL<  spinal  cord  are  supported  by  a  network  or 
yywtfrk  of  delivnte  peculiar  liaHie  called  ngtiroflia,  aiialofptus  to  and 
Mm|  Btuch  lite  nine  function  m  Kiit  diHereot  in  origin  and  nature  from 
cHMlttva  tiaua.  TIub  neurofjlia  forms  a  ahcolh  to  ihe  nerve  cell  and  to 
|lt|>nBMa,  M  well  ns  to  ihe  nerve  fibres  runnin);  both  in  the  white  and  tbo 
piTBdilter;  li en ce  within  the  eeiilral  nervous  Bjelem  the  fibres,  whether 
■MilnlUtcd  ur  no,  poasc  no  Mrparate  neurilemma:  tubular  sheaths  of  tlvc 
pfarofUa  give  the  axis-cylinder  and  nicdullA  all  the  suppuri  they  need. 

All  Ike  nerve  celb  Dftbe  anierior  cuniu  probably  poase«s  lui  axiii  cylinder 
mem,  and  other  e«iU  similarly  prnv><led  ntlh  an  axis  cylindi-r  pmcnui  lire 
land  in  oUwr  parti  of  tbe  gray  matter.  But  in  reriaiu  parts,  o*.  for  iiwtaiicc, 
btlw  |RMWrior  comu,  many  of  the  oella  appear  to  poiaew  no  axi^rylindcr 

Cs;  In  aueh«Mtaall  the  procMtei  appear  to  bmnch  out  rapiilly  into  lino 
nt«L  Except  for  thi«  abaenue,  apparent  or  real,  of  iia  axis -cylinder 
fraoaa,  Mch  cwlls  rOMUiblu  in  iheir  iceneml  liBatumt  the  celU  of  tbo  ontsrior 
(■nUithoagli  thay  aro  getwmllv  somenhai  smaller.  Sjitqikiug  gvoarslly 
ikmat  feature  of  the  ner^'e  ccfhi  of  the  central  nervmiK  «y*teni  nf  distia- 
fined  from  the  ganglion  cells  is  the  remarkable  nay  in  which  (heir  pro- 
MMsbmneb  nlT  into  a  number  of  delicate  lilamcnta,  oorr(»|innding  to  th« 
dsDtala  tlainenla  or  (ibnllir  in  which  at  lU  termination  in  (he  ticeuee  the 
tiit-crliiuler  fd'  ■  werw  oftvn  ends. 

i  idO.  PmcD  tbe  alxive  dcecri|itioti«  it  ia  obvious  that  in  the  spinal  cNird 
maUdl  ai  repnwnling  (he  (vnlnd  ncrroiin  syMem  we  may  at  proiieint  cou- 
iM  oataslfM,  iMviug  the  brain  tor  later  study)  aSeront  tibrw  <  hbres  of  the 
pauior  root)  an  io  some  way  by  meona  of  the  gray  mailer  brought  into 
OMictian  with  efi^rent  6bres  (iibrca  of  the  anterior  rnut  j ;  in  other  word*. 
iklMfaMi  oord  ia  a  ctoiire  unitini;  afl^rent  and  eOtrent  fibrvn.  The  npitial 
pOfM  am  tkot  centres  in  thi?  tteiine ;  the  nerve  cellti  oompiMiiiig  tin.'  ganglia 
maaiply  rvlnys  on  ih«  aStnnt  fdirc*  uf  tho  pouvriur  root,  they  have  no 
(MdMjad  whatever  with  i-tTvrcnt  flbroa,  ibey  are  conn«-ml  uitti  lihr«»  of 
a*  kind  only.  Conoeroing  the  ganglia  of  the  Hplaiiehnic  Kynteni  we  eaniiot 
bill  cwMa  make  at  present  a  p<Htitiri;  stalument,  but  the  evidpn<-e  to  fur  at 
MrdkpoHl  pointa  to  the  ooncluntnn  that  iu  tJiem  as  in  the  ipinal  ganglia 
vdl  aerve  call  belongs  to  fibre* of  »im'  function  only,  that  whore  several  pro- 
lof  a  cell  an^  prolonged  into  nerve  fibr«,  thi««  fibr««  have  all  the  MIID« 
>,  tbe  nerro  cell  being,  lu  in  the  apinnl  ganglia,  a  mere  relay.  We 
I  ■Wiihitofy  evidence  thnl  in  a  gnnglinn  the  fibres  snringing  from  or 
id  wilb  one  cell  join  nnolhiT  cell  so  n*  to  convert  the  ganglion  into 
joining  tugulber  cells,  wbuae  nerve  fibres  have  dilfcrent  liiiictions. 
r  shall  ban*  later  flo  to  bring  forward  evidence  that  tbe  nucleated  cell 
\»ij  iif  a  nerve  ell  in  a  ganglion  or  e)»«wbcre  i»  in  some  way  or  other  con* 
td  with  iIm-  outrilion.  the  growth  and  repair  of  the  nerve  Hbres  umnsing 
I  it.  Bcaidm  thir  nutritive  function  the  multipularcellnof  tbesplaaiailiio 
ipprar  to  serve  the  purpose  ■  if  multiplying  the  tracts  along  which 
B«  impulses  may  nassL  An  impulse,  for  instouce.  reaching  a  multip'ilnr 
I  line  of  the  proxiuiul  (■ympalhelic  ganglia  along  one  Dhre  or  pmoen 
tre  in  very  many  casea  being  a  medullated  &br«)  <«n  pOM  out  of  the 
■D  various  directions  akxig  several  proeeasea  or  fibr«a,  which,  in  tbe 
ity  of  CMMs,  if  not  alw«ya,are  non-mcdu Noted  llbrta.  Thux  theM'  nerve 
lOrgansof  distnlnitiou  for  iinpubes  of  the  wime  kind.  Wlnu  further 
liana  of  the  imniiLM«  thtu  imsalng  tlirough  tliem  ibeae  ganglia  may 
t  about  we  do  not  kn«n-. 
I  only  in  aome  few  iittiaiicea  that  vre  have  any  indications,  and  tliose  of 


ailTKRAI.    KKATPRK9  Or   WEBTOPS  TlSfltTKS. 


vittidratrn  froni  the  stiinuluH,  or  tlir  movenieDt  U  colcuUml  Ki  push  ur  wipe 
Bff  ay  the  auuulus.  In  other  words,  a  cenain  pitrpme  is  evident  In  Ike  refflei 
act  km. 

Thus  in  all  cases,  exc«pt  perhara  the  very  wmpleM,  ifae  rmiremenu  aall«l 
fivrl))  by  a  rv&vx  action  are  exceeoipgly  coniplt-x  cutiiiiarvH  nith  t\>a»  which 
result  IKiii)  tli«  direct  iititimlation  of  a  motor  trunk.  Wheit  tho  piTtphcnl 
Htmup  of  a  divided  Miativ  nerve  b  siiiniilnted  with  the  iaterruptcd  nurmit. 
the  mosclcit  of  the  )e)i  are  at  i)n<-e  thrown  into  tetanus,  cviiitinue  in  the  fawt 
rigid  iiinilitiim  diiriD)^  the  )NiitM|;e  uf  the  current,  nnd  nrlii\  inimii|iiit4!Jy  on 
the  mrr(-nt  l)rii)){  nhiit  otf.  Wlw-.n  (he  «amc  cunejit  U  iipiilicd  for  n  iieociiKl 
onlj,  tu  the  i>kin  nf  the  llnnk  ofit  hraiidcw  hn^,  iho  1«|;  io  dntwn  u|i  und  tbt 
fixit  nijiidly  ■wept  over  the  fpot  irrilitlei),  in  if  to  vii\>r  nwny  ihe  irritnlinsi 
hilt  ihi«  movirmr'nt  \r  a  complex  one.  rt«|iiiring  tho  (iinirmction  of  imrticulic 
miiKltti  in  a  dcRniir  BniuiTiio:,  with  a  ciirvfuIlT  Adjtiitod  pmportitHi  iMtweca 
Ihe  aniuiinlH  of  mnlriiciinn  of  the  individuiiC  nm»rlce.  And  this  complax 
movemenl.  lhii>  tialanc^l  niid  arranged  i>cric»  of  contractions,  innr  be  reneal«il 
more  than  once  as  the  result  of  a  sin);le  filinuilation  of  llw  «kin.  W  hen  S 
deep  breath  ii  caiwed  by  a  dash  of  cxild  water,  the  same  eoordiiiaUNl  aad 
carefully  iirrnnged  aeries  of  eoutradions  it  also  seen  to  result,  as  part  nf  a 
reHex  action,  from  a  simple  stinuilue.  Aud  toany  more  examples  mjglii  h« 
given. 

In  such  esMs  as  these,  the  complexity  may  he  iD  part  due  to  the  fact  that 
thesitmuluB  u  applied  (o  terminal  sensory  organs  oud  not  directly  to  a  nerve- 
trunk,  As  we  ijJiall  see  in  speaking;  of  the  senses,  the  impulstu  which  sie 
geaeralad  bv  the  application  of  a  stimulus  to  a  sensory  orsau  are  more  ooia- 
pl«X  than  tJiose  which  result  from  the  direct  stiinulntion  of  a  seiwory  uerve- 
trunk.  Keverliieleu.  r«flex  actionti  of  ^i«at  if  not  of  e<(uwl  complexity  twf 
be  induced  by  stiniuti  apj>1i<^d  <lirvctly  u>  a  nerve-trunk.  We  art-.  t)i«rcAnk 
oblijtcd  to  conclude  that  in  a  reflex  action,  the  proc<*»e»  which  are  originnKd 
in  tite  <vntn-  hy  the  arrival  of  even  itimplc  impiilM*  hIoiik  afivront  itvrvA 
may  be  highly  ooinplex ;  and  that  it  t*  the  ^vMWtitutiiui  nnd  condition  of  tbf 
cmtre  which  determine)*  the  complexity  and  character  of  the  movemMlU 
which  are  cfliNted.  In  other  uorils,  a  contn>  concerned  in  ii  rvllex  action  it 
to  lie  regarded  m  oonsiitutiuK  a  sort  of  molvcular  machinery,  the  charadtr 
of  tho  rcaulttng  movementa  being  dotorminei)  by  iIh-  nature  of  the  machinery 
Ml  going  and  its  condition  at  the  time  being,  the  chnntder  nnd  antount  w 
tho  aflerent  impiilseM  deterniiiiing  exactly  what  jinrta  of  and  how  far  lb* 
central  machinery  is  thrown  into  action, 

Throughout  Ihe  above  we  have  purposely  us«d  the  word  centre,  avoiiliof 
tlw  mention  of  uerve  cells.  Hut  iiuaoubiedly  the  pari  of  the  spinal  eora 
AVting  OS  centm  of  reHex  action  is  situated  in  tlte  uray  matter,  which  gray 
matter  is  chamcterixed  by  the  presence  of  uer^'e  cella ;  undouhiedly  also  [lie 
etlerent  fibres  are  coniiecied  with  the  afTereni  libres  by  means  of  cells,  cer- 
tainly by  the  eelle  uf  the  anterior  oomu  described  in  $  !>!*  aii<)  pruhuhly  also 
by  other  cellf<  in  tho  na8terii>r  curnu  or  elsewhere.  Hn  that  ii  n-tlex  nition  t* 
carried  on  undoubteoly  tfirouffh  cdls,.  Hut  it  docs  not  follow  that  a  cvllular 
mechaiiisui  is  eeseiitial  in  the  sense  at  nil  eveiitji  tiiat  the  unelei  of  the  evils 
have  anything  to  do  with  the  matter,  or  even  that  ibe  most  iniporinnt  of  the 
mnleviilar  processes  <H)iistiinting  Um  change*  taking  places  in  n  cenin-  during 
n  rellex  iicliim  an-  cjirn^'d  mit  onir  hy  the  cell  suliftanc*'  imuuxiialclv  sar- 
roiiiKliiig  iht!  nuclei.  The  jiowcr  of  carrying  out  a  reflex  action  in  proluibly 
contingent  on  tli«  natun-  nnd  arrangement  of  a xis-cyi indent,  a»>l  of  the 
branching  mstrrinl  hy  which  in  a  nerve  centre  tho  alfetvnt  and  efferent  nxi»- 
cylinder*  arc  joioeil  togi-ther,  the  nuclei  intervening  only  so  far  as  they  have 
to  do  with  tho  growth  and  repair  of  the  nervous  material. 


GINERAL    PCATUHES    OF    NERVOda   TI88UIS. 


169 


Mirmil impalws, nisy  mil  forth  it  cuiivuImvo  liluf  cuuf;hing,in  which  n  verj 
Ivyi  auinbvr  or  niutcln  xrc  thrown  into  rioletil  contrftcliuna;  vberMB  lIh- 
not  tiiBtirl  of  (he  hnir  wiih  oilier  eurliiccn  of  the  hotly  mny  produce  no 
(ktltra  cflisct  at  atl.  Similarly,  whilo  in  the  brainlcfe  but  otherwise  iiarmal 
ftvfti  ■light  touch  lU)  the  skui  of  the  Hnnk  will  produce  uolhin^  but  a  fuint 
titt  of  the  underlvin^  muitcl^  tiie  Bame  touch  on  the  same  part  of  a  frog 
ptMMl  will)  slfychiiiue  will  produre  violent  tasting  teianic  contntclions  of 
MVlt  di  the  mutctee  of  the  body.  Motor  inipulses.  at  ire  have  bc«d,  travel 
tbof  OMlor  nnrreit  «ttliout  any  ^ttM.  expenditure  of  eoergy.  and  probably 
widmt  IncreaMiiK  lluil  espeudJItiru  »  tbey  proeii-^d  ;  and  [W  same  is  ai>pa- 
nHlT  iW  CTur  with  allvreiil  impulH»  paunne  alonj;  aft'en-ni  n«rv«).  Wheti, 
hwVrr,  in  u  n:f)i-x  mti'iii  alli^reiil  impulses  reach  the  nerve  oeuira,  a  cliSDjte 
fallwMtDrv  Btul  uw)^iitiid«  of  the  iiupulM«  lak«s  pinoo.  It  is  uot  that  in 
iWMrr«  ectiin.-  Ihe  alfi>rvut  impulse*  sn  simply  turned  aside  »r  reflected 
bill  riltcvnt  impuliMX:  aud  hence  the  name  "  rellcx  "  uctinn  is  a  bod  one. 
It  n  rather  that  lh«  nllStreni  impnitea  ad  afreah,  at  it  wen.-,  tu  a  Mimulua  to 
Ibanrv  contiv,  producing  nccnrding  to  circnmstancea  and  cvHidiiions  cither 
■  Ira  >cak  vflintvnl  inipulMa  oraintiltituileof  utrong  one*.  Thv  nerve  rcnire 
Btt  W  rvgardeil  m  a  callcoiion  of  c xpluaive  chargi«  ready  to  be  dUcbnrged 
■il  M>  lo  atari  oHervtit  impulmy  along  cvitain  vtlm-nt  ncrvcv,  and  thote 
ikmtarvaoarraUMd  rim)  w  rcJatnl  ^l  crtntn  ttfli-rcnt  uerris,  that  alli;reiit 
isjalHa  loichinr  ua  ocntre  along  thom  ii(Tvn:>  may  in  one  t'iuw  dwchnrge  a 
Iff  anljr  of  the  cnargot,  and  so  give  rim  to  fwhle  movonionU.  and  in  nnutlMr 
^ttiBlAmtffi  a  very  large  numbor,  and  eo  give  rise  lo  large  and  violent 
Mnmnta.  In  a  reflex  aolioD  th«i  (h«  number.  inlen«iiy,  chnracler.  nnti 
ttuflntlon  of  the  eOerent  inpuleea,  and  so  the  kind  and  amount  of  raove- 
■nt,  will  depend  i^htefly  on  what  takes  place  in  the  eciilre.  and  this  will,  in 
Hro,  ibfwnd,  on  the  one  baud,  tin  ihe  cunditioo  uf  the  i^enire.  and,  ou  ihe 
mWt.oh  il*e  qiectal  relatiooi  nf  the  oeulre  of  Ur-  afTen-Jil  iinpultiee. 
At  tilt  ttme  lime  we  ore  able  Ut  recognize  in  uiunt  tuDi-x  notions  a  certain 
between  ihe  Mrenglh  i<f  ihe  utimuluH,  or  the  niaguitudi;  of  the  aller- 
impuhea  and  the  extent  nf  the  movi^mrnt  or  tbc  magnitude  of  the  etlVrenl 
The  nerro-ocn Ire  remaining  in  the  unmv  ronditiuu.  the  sironger 
iraan  inimeroua  atftrcnt  impnUcs  will  give  ri^  t»  the  more  forcible  or 
■or*  KimprahrnMiTe  niciviMnentH.  Thu«,  if  a  flank  of  a  hrainlen  iVog  lie 
nn  lightly  tuuchfci,  the  onl^-  reflex  movement  which  is  vifihle  is  a  nligbl 
ttiidiiDg  of  tbo  niuaclm  lying  inimtvliately  tindnrnralh  the  spot  of  skin 
itiaaklMl.  If  Ihe  stimulus  Ik-  int-rvnsc-d,  ih«  iDovoments  will  sptvwl  to  the 
Ukfrkg  nf  (lie  ■aim-  ojde,  which  fn:(|tiently  will  execute  a  niovemenl  ealcu* 
hud  lu  puab  ta  wipe  awny  the  rtimulu*.  Ry  forcibly  pinching  the  santc 
^>if  skin,  orotkerwis'-  inrrcnj>ing  the  stimulus,  the  rt^iilling  movemenlp 
aai  In-  led  to  rnibran^  ihv  forr-leg  of  the  same  side,  then  the  opivwile  side, 
•M  Gaally.  almiwt  all  th«-  inusclee  of  the  body.  In  other  word*,  the  disturb- 
I  RioiBg  in  Um'  cvntre.  confined  when  Ihe  stimulus  is  slight  to  a  small 
of  ifae  centre,  overflows,  su  U>  siieak.  nbeii  the  stimulus  ia  increased,  to 
pane  of  the  eenirv.  and  thus  throws  impulses  into  a  larger  and  larger 
tt  of  e&rent  nerves. 
Wt  laay  Mid.  without  going  more  fully  into  the  subjeet  here,  thai  in  mon 
ntrxai^oua  a  sjiectal  reialion  may  be  observed  h«tweeu  the  jiart  stimulale<l 
'  tke  resulting  mureraeoi.  In  the  simplBSt  eases  nf  reflex  action  thb  rela- 
ii  turrely  of  such  a  kind  thai  the  muaoJca  tbrowu  into  action  are  tbwe 
I  by  a  motor  uerve  which  b  tli«  ftiDow  of  tbe  sensory  nerve,  the 
latiiMt  of  whiHi  calls  forth  the  moveittent.  In  the  more  complex  reflex 
iiiM  of  the  brnJuleai  fnig,  and  in  other  cawa,  the  relation  is  of  aucfa  a  kind 
tbe  raaulting  movemeiii  heai»  an  adufAatioit  to  llic  stiniulua :  tbe  foot  i» 


170 


UEN£RAt.    FUATlfKUS   Uf    N£KV01IS   TISSL'CS. 


withdrawn  rrom  the  slitnultu,  or  the 
In  other  wo: 


llUB 


urd?, 


renient  is  ai]eulftt4!d  to  push  or 
a  c«riBin  purpow  is  evident  in  the  rvBez 


awftv  the  stimii 

IK-'tioD. 

Thus  ill  nil  cnsee,  eioept  perhaps  tlie  very  Mtnpleat,  the  inovenienu  unlM 
forih  hy  a  reBex  action  are  exceediii);ly  complex  cDiupnred  «iih  thoM'  which 
rtnilt  from  the  direct  atimulation  of  a  motor  Inink.  When  Ihe  f)eH|>h<^raI 
B|iiui[>  (if  a  divided  sciatic  nerve  is  sliniulaied  with  the  inlerrupted  etirreni, 
ihe  itiuiiHes  of  the  leg  are  at  oiiee  thri^vrii  inln  tetuuui>.  continue  iti  ih«  ^stne 
rigid  Liindiii'tu  (luriii);  il>e  puiMky:e  of  the  current,  aiid  relax  iinmediabely  on 
the  curreiil  bein^  abut  oS*.  When  the  Miiuie  current  u  applied  for  a  aecoad 
ouly,  lo  the  skin  uf  the  flajilc  of  a  bminlenii  {nig.  the  left  iiamurn  up  uihI  the 
foot  mpidly  Nwrpt  iivur  the  «pi>t  irritated,  tu  if  t»  wipe  away  llie  irritation : 
but  thi*  niovemi-nt  \»  a  complex  one,  nyjiiiring  tlie  (■oiitnictiuu  of  jittTticular 
hiumIm  in  It  defiiiilu  *ei|ut:iiM!,  with  a  cnrefullv  udjuflcal  (irojiortiou  bctwcail 
the  Binouiitu  of  contraction  of  the  individual  nnMtcloi.  And  thtf  complex 
movement,  thi*  biilancnl  and  nrnin^i  Hcrioi  of  coniraotiomt,  mav  ht  rcpmitcd 
tuurv  thiu)  onov  la  tlit-  rcsidl  of  a  *inglc  MimulalioD  of  thv  slcin.  W  hen  A 
deep  bnutth  i»  oiu^'.d  by  a  dni>h  of  coh)  water,  the  Minie  cnonlinntcd  nntl 
cnrciwlly  nrniiiged  Hcrit*  of  coiilrnclioni'  ij«  also  w«n  lo  nviill.  n>  part  of  a 
rcflax  action,  finom  a  simple  stimulus.     An<l  many  more  oximiplM  might  b« 

In  such  cams  iis  thesis,  the  complexity  may  be  in  pari  due  lo  the  fact  that 
the  stimulus  is  applied  lo  terminal  tvuf^rf  organs  mid  not  diric<ctly  (o  ii  uerve- 
truuk.  As  we  shall  see  in  speiiking  of  the  senMs,  the  impulses  which  are 
generated  W  the  application  of  a  stiiuiihis  to  n  sensory  organ  are  more  com- 
plex than  those  which  result  from  the  direct  stimulation  of  a  sensory  iierve- 
tnink.  Nevertheless,  reHex  actions  of  great  if  not  of  equal  complexity  mar 
be  induced  by  stimuli  applied  directly  to  a  nerve-trunk.  We  are,  therefore, 
obliged  to  conclude  that  in  ii  rutlex  actioti.  the  |>rocucie«  which  are  origiuaic<l 
in  the  reiitrn  br  the  arrival  of  even  simple  impulua  along  oflitreni  ncn-a> 
may  Ix)  highly  complex  ;  and  Ihul  it  i»  the  couMitntion  nnacondition  of  the 
centre  which  determine*  the  complexity  and  chnriieter  of  the  movements 
which  are  elTecied.  In  other  nords,  a  Mtutre  cuncerned  in  a  rtdlcx  aciion  is 
to  be  r^nrded  as  constituting  a  sort  of  niulecular  raachinorr.  the  character 
of  the  mulling  movements  liemg  detr:rminc<l  hr  the  nature  of  the  machinery 
Mt  going  and  its  ondrtiou  nt  the  lime  being,  the  chariicter  and  amnuni  of 
|]ie  aRi-rent  impntm-s  determining  exactly  what  |>arts  of  nnd  hoir  far  the 
ccnlntl  machinery  is  thr-iwn  into  iietioD. 

Throughout  the  above  wo  have  purtMisely  used  the  word  centre,  av')iding 
the  mention  of  ner^'e  cells.  Itut  um)i>nblcdlr  the  part  of  the  spinal  cord 
acting  as  centres  of  rcllex  action  is  situated  in  the  gray  matter,  which  gray 
mailer  is  chanicteri/^d  by  the  prciience  of  nerve  cells;  undoubbodlr  also  the 
eflerent  fibre#  are  connected  with  the  atleivnt  libres  by  means  of  cells,  eer- 
taiiily  by  the  cells  of  the  anterior  cuniu  (le«cril>e(i  in  !i  ti!>  and  probably  also 
by  other  cells  in  the  jx'iAti-rior  eornu  or  eiaeivhere.  So  that  a  retlex  acliou  b 
carried  on  undoubtedly  Ihrougli  celk  Dot  it  docs  not  follow  that  a  cellular 
m«chanism  t<  cwentiul  in  the  sense  at  all  eveuU  that  the  nuclei  of  the  cells 
have  uiythiog  to  do  wilJi  the  matter,  or  even  that  Die  niosl  importam  of  the 
tDolet'ular  proceiKii  conntituling  the  chanKca  taking  plai-e*  in  a  centre  during 
a  rellcx  action  ore  carnal  out  only  by  the  cell  Hul(siant«  luimediaiclv  mir- 
rounding  the  nuclei.  The  power  of  eiirrying  out  a  reflex  action  in  ]>n)liahly 
routingtmt  on  the  nature  and  nrranjiement  of  axiii-cvlindcrt,  and  of  the 
lininching  material  by  which  in  ii  nerve  (centre  the  alVrrcnt  nnd  eHi-'ivnt  axis- 
cylindcri  are  joincil  Ingethcr,  the  nuclei  inl^-rvwiiiig  only  so  far  as  Ihey  have 
10  do  with  the  growth  and  repair  of  the  nervous  material. 


OKffftllAL   rKATL'tlKS   OT  N8RVOCS   TISSCKS.  171 

:  101.  Aidamatif  iKii&nM.  Efforeoi  iin|)ulM»  froquently  iiiiie  frmu  the 
~  I  tad  vpioal  cnrd  mi)<l  su  give  ri«c  lo  mnrpmcntfl  without  Mag  ubvioutlj: 
by  ftnjr  BtiinuUtiuii.  Sucb  louvciovnts  bit  *pcikfti  uF  na  HuloitiKtiv 
auft.  Th«  d&fvnt  ioipulMs  in  xucb  cuws  tire  started  bj  chaDgw 
I  Bwva  ccnire  irKich  tirv  tuA  tbi.*  immediute  r«Hilt  of  lti«  nrrivxl  At  tlic 
lOMUv  of  «llen-Dt  impulse*  from  wiihoiiE.  Hiit  irliich  appcitr  to  ariu*  in 
mv*  OADltx'  itwlf.  CliHDi^  of  Ihis  kind  may  r«i-tir  rlirthmicslly  :  lliue, 
llhall  te*,  we  tikve  rcaMn  lo  thinit  ttml  in  n  cerlttin  part  of  the  mt-diilU 
.  cluuiKfa  of  the  o^rvotiB  materia),  recurring;  rhythmically,  lead  to 
kythmiv  dwrltarKv  alone  c«riaio  nervM  of  ei&renl  imputic*  wherry 
I  conneoted  wtlli  llii<  cbcei  nr«  riiytbinically  thruwn  iuto  soliun  and  it 
_  .  nically  r«peaioil  brealhinv  is  brought  about.  And  otli^r  Kimilnr  rhyth- 
Htaioiniilio  inovt:iii«iitt<  may  m  atrri^ti  out  br  other  parts  of  tli«  spinal  cord. 
Pnn  Ibo  bmiii  itself  a  much  mure  varied  ami  npfiar^uily  irrt.-|{ulur  di«- 
ttgpat  rtlirviil  iiii])ii)»t«.  net  lh«  obviuiia  nvull  of  any  iminvUiaivl^'  for?- 
fill  illtTeiii  impuliMtt,  and  t)M-rff»ni  not  formiiijt  part  of  reAex  actiona,  it 
WJ  atintnon,  miidtitiitinjt  what  we  apcalc  of  as  vulition,  eflereui  iinpulsM 
ikatuiiiib);  being  called  voliltunni  or  voluntary  itopuUe*.  The  npinal  oord 
qwifRMn  lite  limin  dow  not  appear  aipuhl«  of  «zAoiiting  thiM!  voluntary 
BMonmi* :  but  to  Xhm  au1>J4«t  w«  tludl  retuni  when  •m  come  to  ii[ioak  »f 
iWnnual  aarvoiu  nyvtem  in  detail. 

Wtmid  juRt  now  that  th«rc  i*  no  antisfaciwy  ev!i)cnoo  that  t)i«  ganiili*  of 
ibifUiichnic  •nrMnm  «vcr  ad  w  (M.-ntrc8  of  ra flex  action.  TIm  eruleiio*, 
iuiriv,  that  tnow  ganglia  may  Mrvc  as  conlra  of  rhythmie  Mitomatlc 
■MOM  at  firf>t  eight  of  »»mc  stirngth.  Several  organs  of  ihd  1>odr 
sing  naecular  tij«ue,  the  most  notabln  being  the  heart,  are  during  Vitt 
'\  IB  riiytfamic  autotnalic  iuovenieDt«.  and  in  niiinv  cato*  oonlinne  thtf* 
inis  aA«r  renMVal  frf>m  the  body.  In  nearly  all  titeae  caaea  (rau){lia 
vtpnacnt  in  oonnectlou  with  the  mutu.'ulur  tiMM«:  and  the  preaeooe  axul 
nMd  euulitjon  of  th«n  puiiiiia  t-am  nt  all  evenu  in  many  ouea  in  tone 
«iti«ent«al  to  (hi-  due  |iprformBn(«  of  (he  riiythmic  auiontalio  niovemi-nla. 
bjnd,  it  ha*  brvn  ihmitihi  thai  the  iDovementa  in  rjueition  are  DMilly  due 
biW  rhythmic  auiimialtc  generation  iu  the  cell*  of  thcai-  ganglia  of  uiTerout 
■ifalm  which  paaHngdowo  to  (he  a|>proprial«  muwular  fibrt*  call  forth 
kr  ifcrtliraic  movameDt.  WIku  wv  come  lo  otiidy  tlicao  mi>vemci)t«  in  detail, 
Wifaall  find  nMoiu  for  coming  to  the  conclusion  that  this  view  in  not  sup- 
|Mlal  by  luieqttMc  «vi(l«ocfi ;  and,  indeed,  though  it  i*  perhaps  immacurc  to 
•iki  a  dogmatic  ateiWMMit,  alt  tlw  evidence  goes,  aa  m«  have  alrcailyMid, 
titfew  tbat  i1k-  great  use  of  tlw  ganglia  of  the  snlanc!hDic  ^sleu,  like  that 
rflbtlpiltal  ganglia,  is  connectmTwith  the  nutrition  of  the  nerves,  and  tbat 
Aaaanifllam  do  no*  like  the  central  nervous  system  act  aa  centm  eitlicr 
Mt«atic  or  reflex. 

f  108.  Inkibiliiry  nenf.  We  have  said  that  the  fibrea  of  the  anterior 
nNiboutd  be  calM  eflerent  rather  than  motor,  becau»  thou);h  they  all 
any  inpiilaea  outa'ard  from  (he  central  nervous  aysteni  l<>  the  tiwttw,  the 
tataUa  vhich  they  cany  do  nut  in  all  casea  lead  to  tlie  eoutractton  of  miu- 
(w  Cbrva.  Some  of  titeae  eifervtit  l)br««  are  distributed  to  j^laodular  ttruo- 
>Mm,  ftir  instaoM  U>  the  aalivary  glanda,  and  impulses  pusaing  along  these 
lad  Id  changea  In  opiibdlal  eelu  and  their  surroundings  whereby,  without 
uymucnlar  oonlrai-tion  necvMMrily  inlerveniDg,  xecretion  u  brought  about; 
tkt  sdioD  of  tboM  libret  of  accrbiiou  we  shall  study  in  coniteciion  with 

BaHia  (his  ihert  are  efferent  fihre)>  going  to  muMuIar  tinue  or  at  all 
enats  tu  musmlar  orgaiw,  (he  inipulM*  piii<iiin>[  alung  which,  so  far  from 
Miimif  almtit  innN-nrnr  I'ontractiun.  diminisli,  hinder,  or  Mop  moveniculB 


172  QENEBAL    FSATUBBS    OT    NERVOUS    TlflSUBS. 

already  in  proeress.  Thus,  if  when  the  heart  is  beatin);  regularly,  that  is 
to  Miy,  wheii  me  muscular  fibres  which  make  up  the  greater  part  of  the 
heart  are  rhythmically  contracting,  the  branches  of  the  pneumogaatric  nerre 
going  U)  the  heart  he.  adequately  stimulated,  for  instance  with  the  interrupted 
current,  the  heart  will  stop  beating ;  and  that  not  because  the  muscles  of 
the  heart  are  thrown  into  a  continued  tetanus,  the  rhythmic  alternation  of 
contraction  and  relaxation  being  replaced  bv  sustained  coatraction,  but  be- 
cause contraction  disappears  altogether,  alt  the  muscular  fibres  of  the  heart 
remaining  for  a  considerable  time  in  complete  relaxation  and  the  whole  heart 
being  quite  flaccid.  If  a  weaker  stimulus  be  employed  the  beat  may  not  be 
actually  stopped  but  slowed  or  weakened.  And,  as  we  shall  see,  there  aie 
many  other  cases  where  the  stimulation  of  efferent  fibres  hinders,  weakens, 
or  altogether  stops  a  movement  already  in  progress.  Such  an  effect  is  called 
au  inhibition,  and  the  fibres  stimulation  of  which  produces  the  effect  aic 
called  "  inhibitory  "  fibres. 

The  phenomena  of  inhibition  are  not,  however,  confined  to  sucb  cases  u 
the  heart,  where  the  etferent  nerves  are  connected  with  muaculu-  tisBue& 
Thus  the  activity  of  a  secreting  gland  may  \t^  inhibited,  as  for  instanoe  whm 
emotion  stops  the  secretion  of  saliva,  and  the  mouth  becomes  dry  from  fear. 
In  this  instance,  however,  it  is  probable  that  inhibition  is  brought  about  not 
bv  inhibitory  impulses  passing  to  the  gland  and  arresting  secretion  in  the 
gland  itf^lf,  but  rather  by  an  arrest,  in  the  central  nervous  system,  of  the 
nervous  impulses  which,  normulty,  passing  down  to  the  gland,  excite  it  u 
we  shall  see  to  action.  And,  indeed,  as  we  shall  see  lat«r  on,  there  are  many 
illustrations  of  the  fact  that  ntferent  impulses  reaching  a  nervous  oratre, 
instead  of  stimulating  it  to  activity,  may  stop  or  inhibit  an  activity  preri- 
ously  going  on.  In  fact  it  ti<  probable,  though  not  actually  proved  m  every 
case,  that  wherever  in  any  tisiue,  cnei^y  is  being  set  free,  nervous  impulsn 
brought  to  bear  on  the  tissue  may  affect  the  rate  or  amount  of  the  energy 
set  free  in  two  different  Wat's ;  on  the  one  hand,  they  may  increase  or  quicken 
the  setting  free  of  energy,  and  on  the  other  hand,  they  may  slacken,  ninder, 
or  inhibit  the  ^letting  free  of  energy.  And  in  at  all  eventa  a  large  nnmber 
of  eases  it  is  possible  to  produce  the  one  effect  by  means  of  one  set  of  nerve 
fibrcH,  and  the  other  effect  hy  another  set  of  nerve  fibres.  We  shall  have 
occasion,  however,  to  study  the  several  instances  of  this  double  action  in  the 
appropriate  jtluces.  It  is  sufHcient  fur  us  at  the  present  to  recognize  that  a 
nervous  impulse  passing  along  a  nerve  fibre  need  not  always  set  free  energy 
when  it  reaches  its  goal,  it  may  hinder  or  stop  the  setting  free  of  energy  and 
is  then  calle<l  an  inhibitory-  impulse. 


The  blood,  ns  we  have  nid,  is  tlic  inlenial  luedimn  on  which  the 
tiatt  lire ;  from  it  these  drair  their  food  and  axvgea,  Ut  it  tber  give  up  ilio 
ptdmU  or  vme  inattere  which  the}'  Ibriu.  Yhe  tiaauM,  with  toiiic  fuw 
aaif&out,  MTt  tntreraed  l>r,  and  ihua  the  eJeraeolB  of  the  tiaiuei  Humuwled 
h,  Mtvorks  of  mtuute  lliin-wstled  lubee.  the  ra/iiflarii  bloodvetneU.  Tlie 
timmiuar  Mriuled  tuuscle  fibre,  for  iostaiiee.  ia  surnHiiideil  by  cnpillariM. 
nmaf  in  the  (vnmevtive  (iaaiie  otileitle  but  iluiM;  lo  the aarcolemma,  nrrangan 
biMKcrk  with  uKirt-  or  leM  n?ctaugular  nit'.ibeN.  Thriu- cupillnrtm  urv 
dtNd  tub<«  nith  <NjntiniiuuK  nidti,  and  the  hhmd,  nbich,  nit  nc  xltnll  ttx,  u 
flMmallf  Hrcamiog  through  tbem,  a  at  a  whole  »>iili(i«d  lo  tJicir  channela 
ml  iom  But  cacapv  fn>m  theiu.  The  elementa  of  the  tiwtiM  lie  out«iile  tin 
HulkriM  «od  forai  ettravimcular  xMrit,  nf  iliHbmit  forin  nnd  «iie  in  tliC 
diMat  ti«UM.  uirroiifiiU.ll  hjr  I'ttpillury  nHworlu.  Hut  the  nali»  of  the 
afQUnia  an  •»  (liin  and  of  nuch  n  nutiirr  thul  certain  of  the  const itii elite 
iftW  blnid  pim  frtiiu  ihe  inlrrior  tif  the  rapitlan'  thrr>ii)^h  the  rap)  I  In  ry 
nil  III  the  clcnicnls  of  tbt-  Iimuo  ouUid*  tlio  capillary,  and  siniilarlr  certain 
•f  iht  cuostiluentfi  of  the  tissue,  to  wit,  certain  sutwtanoes  the  result  of  tlte 
■rtiimltiiii  coolinually  K'^inK  on  in  the  liaeiie,  paaa  from  the  tiwue  i>iit<iide 
llNi;af>illarTUir<>uyh  tlte  <:apillary  wall  into  the  blood  flowiiig  throujih  tbe 
afilhrj.  Thua  u  we  have  already  nid,  $  13,  there  ia  a  coDliuual  int«r- 
daim  of  matenal  between  the  blood  in  the  capillary  and  the  elciaeudt  of 
ikuaite  outside  the  capillary,  the  Irniph  acting  aa  middleman.  By  UiU 
bhtthiaxv  the  tifuue  liv«  on  the  blood,  and  the  blood  \a  aflected  iiy  il« 
(Mife  tbnHi);!)  the  tiMue.  In  the  aruull  aruriea  which  end  in,  aud  in  the 
«*U  niiM  which  Itejcin  lu  the  capillance,  a  dmilar  interchange  take*  place : 
ta  the  amount  of  iiitcrchajice  diminishea  us,  paatlng  in  each  direction  from 
IW  capUario,  thu  wall*  of  the  arteries  and  veiux  become  thicker;  and 
iKkH,  in  all  but  tlu'  minute  veinH  luid  arlerin,  the  intrn'hange  is  m  Miiall 
ika  ii  may  prBclically  be  ncgU'Clod-  It  in  in  the  cnpilhinnt  (and  minute 
antria  and  Tcin^j  that  the  bui<iiieM>  of  the  blond  Lt  itntin^  it  i»  in  ihi.'w  that 
tW  inierclianp.-  Inkm  |>tnoe:  an<l  the  olijecl  of  thr  vnu'iilar  mcchnniiim  is  to 
nan  the  blooil  to  tl>.>n-  ihroiij^h  tht-ve  in  n  nianner  IkwI  ailuplcd  for  currying 
« tUi  bt«rchaiiuc  under  varying  ctrcumstanoca.  The  ii«n  of  the  art«nw  la 
ii  the  main  aimpTy  to  carry  the  bluod  in  n  auitablc  mauucr  from  the  heart  to 
thi  apillnrici.  t^e  uae  of  the  veina  ia  in  the  main  aimply  to  carry  tlic  blood 
hn  the  capillaries  back  to  the  heart,  and  the  uae  of  lh«  heart  is  in  the 
•ain  viBply  to  drive  the  blood  in  a  suitable  iDaaitor  through  tlic  arteriee 
<M«  the  ca[Hllaric8  and  from  the  capillnrim  back  along  the  vcitta  to  itself 
■pin.    The  structure  of  these  several  p«n«  is  tidttpt«d  to  these  several  uaaa. 


Tht  Sirvtiiift  of  ArUriet,  C'-apillarta,  and  I'eiiu. 

}10S.  On  tom«Jt»t»rtM  of  mnfKWtfw  (wti/-.     The  hrarl  and  bloodvaaeli 
ut,  broailly  speaking,  made  up  partly  of  iniwcular  liaMe  with  its  appropriate 


174 


THE    Vi8CI 


nervous  elenienie,  mid  parlly  ufcciiAiH  vurielim  of  the  imut-  known  n«  con- 
nvclive  tii»ue.  We  nha))  have  di  xpcnk  of  Momv  of  ih-  ftwlun^  of  counective 
tiuMO  of  i-ihynulo^iftil  )iii|Hir(nii('i^  whi-ii  nc  cnint'  to  dcul  wiili  tho  Irniphiitic 
Sfsloni.  for  lliio  synlwii  w  iiitimuU'lv  iimormtct)  with  ooimi-clivi;  liauv.  But 
an  iiiWH'iatkiii  rnilv  Ii-m  <-1>w  OxUli^  lictwwn  llio  blixjilvnitrh  mid  oonncctiw 
lisxip :  for  ojiintntivc  ti«<iii-  not  nnly  ontm  Inr^ly.  in  ono  or  otiier  of  iu 
fonnM.  into  iho  viruciurr  of  th<i  blood vrsvlo,  but  nUu  torrn:*  *  sort  of  bed  bulh 
for  Ibc  Inr^r  vctwln  on  tlicir  way  to  and  from  llio  several  tisf  ilea  aud  orgaiu 
and  for  Ibc  siniillor  rcwde,  including  thtr  cnpillarics,  u-iibin  each  tiasuc  and 
or^nn ;  ii>di.<vd.  n  cupillarr  may  bo  regarded  as  a  minute  tubular  [WMage 
hollowed  out  in  the  vi>i]Rcctive  tissue  whlrb  binds  together  the  elenienu  of  a 
ti»eue.  It  will  bo  dmrabK  thorefbrc,  to  point  out  at  ouce  a  few  of  the 
chnractc^rs  of  cunncctive  lissup. 

Tlie  coBDCClive  liwuc  of  tbe  adult  body  is  derived  from  certain  imviiblutic 
i-elU  of  the  embryo  and  cDDsietS  eseeiUially  of  certain  celU,  nbitdi  do  not  He 
in  close  contact  niib  eacb  other  as  do  liie  celU  nf  i^pittieliuni,  but  am 
if[iafated  by  more  or  lest)  inler-cellular  luaterinl  nhicli  tuny  in  <x'rtnin  c«Ma 
be  fluid  or  semi  fluid  but  which  is  {(enerally  wHd,  and  in  oitiiinioiity  ojiokca 
of  as  matrir.  [n  mu»l  fonuB  of  connective  tiwuo  the  matrix  in  rclutivvU-  ao 
abundant  and  proruini'iit.  that  the  (%1U,  or  mmeetivf  H/trw.  rorpuitciM  as  tWy 
art'  callcil,  become  incouiipir'nousi;  and,  speaking  gon^trally,  the  value  of 
cnnn«ctive  ligsue  to  the  body  degMtnclit  innoh  mora  on  tho  ([ualitJes  of  tbe 
Rintrix  ihiiu  on  tbe  activity  of  the  connective  lL-«ue  corpneolm. 

Tbe  kind  of  coiincclivo  tStnur,  itomclinii'H  cjilb^d  "  loose  conncctivu  tissue," 
which  wrajw  round  and  fnrmn  ii  WI  for  thi;  bloodvessels,  cunsista  of  an 
irregular  iDCuhwork  formed  by  tiitorlncing  bundles  of  various  snes  wbidi 
leave  bctwucn  llicni  ipacM  of  ver>-  variable  form  niid  aiie,  eonie  being  n>ere 
chinks  or  clen«,  uthcfs  being  larger  but  generally  Haltened  paawges.  all  cou- 
laiuiog  lymph  and  having  as  we  shall  »ee  s)>ecial  connections  with  ibo 
Iviiipfaalie  vessels.  The  larger  spaoee  are  someiiiuee  called  "areolar,"  and 
i)ii»  kind  of  connective  tissue  is  aometiines  spoken  of  aa"  areolar  ti»iu«." 
When  a  itnmll  portion  of  this  tissue  is  leased  out  carefully  under  the  niicr»- 
scope,  the  larger  butidli'a  may  be  Hejiaraled  into  liner  oundlM,  and  each 
biiitdle.  nbidi  gi'iieriilly  pumui-^  n  navy  ourxe,  has  a  fibrillated  apjitnmnu; 
W  if  made  up  uf  (?x(^t.itia^d y  tim:  fibrilltc;  treated  with  linie-watcr  or  haryta- 
waitr  the  bunillendfiartually  njilit  up  into  fine  wavy  fibrillicof  lott  than  1  (■  iii 
dinmetcr,  a  aulMtancc  of  tt  iieirultar  nature  which  iirevioiMlvcciucutcd  tbe 
(ibriihe  tiiftether  being  dii9olv<«l  out  from  belwuen  th<!iii.  Wlion  a  mass  of 
micb  libritln  i*  bnikil  with  water,  llicy  beoonie  converted  into  ^tnlin.  n  sub- 
Htancv  containing,  like  proteid  material,  carbon,  nitrogen,  hydrogen,  and 
oxygen,  with  a  siiinll  ijunntily  of  "ulpbur,  but  diflcrinjj  from  ]>ri)tt^id  material 
both  in  its  percentage,  compwition,  and  in  it«  proi>crlie».  A  remarkable  and 
well-known  feature  of  gvUiin  i*  that  its  solutions  while  fluid  at  a  tempernturo 
nfliailing  waltT  or  Iciw,  become  solid  or  a"j(illy  "  at  lower  temperatures.  The 
untouched  (ibrillic.  In  their  natural  condition,  bohavo  as  we  shall  se«  in 
B|>eaking  of  tbe  digestion  of  connective  tissue,  somewhat  iliiTerenlly  from 
prepared  gelatin  :  ihe  natural  Hbrilla,  therefore,  docs  iiot  consist  of  gelatin, 
unt  of  a  substance  which  by  boiling  is  readily  converted  into  gelatin.  The 
subetanco  soluble  in  lime-  or  baryta-water,  which  cements  a  number  of 
Bbrillae  into  a  bundle.  up|ieat«  to  be  allied  to  a  body,  of  which  ve  shall 
speak  lat«r  on,  called  mucin.  Since  the  fibrillie  form  by  far  the  greater  jMrt 
of  tbe  matrix  of  connective  titwiie,  a  ijuautjty  of  this  tissue  wl>en  boiled 
seeniB  almost  entirely  <Hinverled  into  gelatin. 

In  collective  tixaue,  Uien.  a  number  of  exceediuu;1y  line  gelatin! ferou« 
fihrillui  ore  ceinenteil  together  into  a  fine  microHcopiu  bundle,  end  a  auinbcr 


riATUKKS   or    VASCULAR    AI>PABATUS. 


175 


•f  tbtM  finer  buiiilk«  muy  be  aitnilarl}'  cetDetitetl  tocether  or  aiiuply  appowl 
HfitWt  to  fnnii  l»r)i;«r  buDdl«e  ;  Mtue  of  the  bundlee  U  leut  «p|)«Br  more- 
•nr  1.1  be  dr-tinnl  by  ■  ile)ic«tc  tnin!t|iar«nl  ^alh  of  a  Minewhat  peculiar 
oiUtT.  A  tiiinilirr  of  these  buiKllM,  tinall  and  In  rev,  are  arranged  aan 
wihaotk,  (hi-  irD'gular  tpacn  of  nbieb  are  oi^upieO  by  Iviiipb.  On  lh« 
«ln<i  ibr  tiiiiiiMtv  rnnani  iho  ipiiCMi  or  b«tnw:ii  llto  )>viKli<-s  wh^^re  titvw 
m  a  iiifuBilti)!!,  iil\r»  lyiii)f  in  nitimlr  tpuctd  hullnwe<l  out  in  ihi-  ii-inoiit  or 
pMnd  Nibkiitnc)-  uiiitior  ibv  binKlIra,  aro  rmiiiil  the  i-nDUiM'tivi!  (twiK-  cor* 
fchfc  I'jich  >if  thcM-  it  a  ri-ll  niQtiiiitiiiu  "f  ii  mic]i-ii>,  trritcnilly  oval  or 
ilwpf r .  •urriiuitili.ll  by  it  pnitoplai'mH'  ovll  body  u»iinlly  inv^'uhir  iti  lurni. 
Majt  Kinirliii)i.-a  invrvty  xpindli- fhit|icd.  bill  nxm  Tttf^ueutly  dnlindly 
kwM  or  iii-llatc.  and  iH-iirly  hIwmt*  inuoh  HatiitKi)  in  ■  plaiw  rorre- 
ifNtdin).'  to  tbr  ilirrvtion  of  the  fibrv*. or  buadlc*  of  the  Rinlrix.  Although 
■  or  hnvc  mid  lbi>  librillir  ara  ccnmud  toscth^  into  ■  buitdic,  nch  Kbrifla 
mtia*  iiilRdriitly  dixtinct  to  hav*  a  roareoil  rolractm-  vlK-c<  uii  raya  of 
%ld  lUliDg  upon  or  traiwinitml  ihrough  tbr  ttmiti'.  «u  thai  iho  bundW 
iffor  while  and  opaque ;  ht-nco  this  titwutf,  and  specially  n  morv  dense  fi>rui 
(<  it.  it  toraelimo  s]>oki-n  of  me  irhilo  tibrou*  tiemio.  Oirinz  bi  this  onority 
ik  nofr  df limle  connective  linue  corpuBclcw  arc  not  rctinily  visible  id  the 
MUinl  nxulituiu  of  (h«  tiHue.  They  may,  however,  U.^  brouglit  (o  view  by 
ikaclko  of  dilute  acid  «uch  as  acetio  acid.  L'mler  the  intliieiiee  of  lbi>) 
mIocIi  flbr^lta  swelb  out.  and  the  swollen  tibrilliv  prcv^ng  u|>i>n  each  other 
na*  Id  rcfnct  li^ht  so  mush  M  befbte.  Hod  thua  become  more  trnnspnreni, 
niyiDWPh  as  an  opaque  maes of  ttripa of  tringhui  beooinn  tmnepareni  when 
iWtffiia  are  swollen  by  bojliiijf ;  ihia  incnaaeof  irannpnrcncy  aJlows  lli« 
■wpamn,  whieh  are  not  mrullen  nul  rather  •hrunkeii  aixl  made  mor«  opaque 
fcf  ibr  artitm  n(  llie  arid,  to  become  visible.  The  prcwnoe  of  these  oor- 
fad*  nay  nltm  be  rovcali>d  by  lh<!  ui«:  of  MUch  Muiuing  rea^ccnu  a«.  whil« 
■M  4ainio^  ibo  fihrillatol  matrix,  ftain  the  nuclei  and  the  proioplanmlc 
kiCa  of  tbtt  ciirptivJoK 

BmUm  time  hmnchrd  irregtitiir-llnttrned  oonnwtive  timiio  cor^iUHclea. 
«kMi  do  Dot  oalurnlly  exhibit  any  nnio-boid  moreinentf,  Icucucvte*.  exbib- 
iuagmmor  Inam-tivc  moTcments.  are  fiitind  in  Iho  spncoa  of  llMtianw, 
kftUer  with  cnrpitw-leaof  a  third  kind  remariinblo  frxmi  the  la?]^  cnartr 
fmaaWa  «itb  which  the  cell  Nihalance  ii  etudtlod,  and  known  na  "  fdaama- 
tufmim." 

(lot.  When  eonnectire  liwiie  ia  rendered  tnin«pare»t  by  the  action  of 
•iilnr  acetic  arid,  there  come  into  rieir  befldes  the  <»rpiiiie]ee,  a  number  of 
Ua«  iGfletvut  I'nHn  the  ([^laiiiiiferous  fibres  not  only  in  not  beins  swollen 
•adiOKlered  tranapareut  by  the  action  of  (he  acid,  but  also  by  tneir  slae, 
thlinly  acuity  number,  clear  bold  outline,  and  sharply  ctirvetl  oourw.  The 
Amwjr  much  ia  uie,  aoine  licin)t  very  fine  »>  as  to  appear  mere  lioea, 
vkQi  Mben  are  very  )arj;e  with  a  diutin<.-t  double  outline.  Whether  small 
vbiye  cwb  6bre  is  a  linvlo  llbre,  mx  a  bundle,  and  cannot  be  split  up,  like 
albviirHnill  bundle  at  the  ordinary  matrix,  into  fibrillie.  ^ol  only  id 
thiir  nxirvF  iharply  i-urrcd  unlike  tlx.-  gently  aweeplng  outlinea  of  the  gela- 
liaifmius  fihree,  but  iltcy  divide  and  aiinntamoae  fte«ly,  thus  furmiDg  Dct* 
•wi*  of  vnrvtnic  shape :  the  gelatiuifemus  fibrillie.  a»  the  other  band.  uev«r 
diriia.  aiwl  tlie  Bundlea  int«rlaee  into  a  network  rather  than  anastomuae. 

Tie  Bumbrr  of  tbvvo  librea  occurring  in  fonincctive  iiwue  varv  much  (b 
difcent  «i(UBlionii,  and  ia  aone  pliiii%  a.*,  for  instance,  in  the  li^mfntmm 
■aricr  t4  certain  anim^  iMBrly  ihc  whole  liii:<uc  ih  ct>mii(ii«d  of  lar|^  librea 
(f  tha  kind,  having  in  the  man  a  yellow  color,  (he  oniinary  gelatinilcrous 
ihiv  biiiig  redurca  to  a  miniinuni.  In  nich  a  ttttualiou  a  remarkable  phy> 
<Wcku«ctar  of  tbtoe  fibrei  it  catJly  reeogniiMMl ;  ihey  are  in  a  high  degree 


176 


TllK    VASCULAR    MBCHAKISU. 


GxtMwi1)l«  Mid  elaMic;  hence  lliey  are  fret|uetillj' called  e^aW>>jt'i>'^>:  lt»»Bl 
ihvtr  )'i-tlowUh  nolor  thev  are  sometimes  oalled  fellow  elastic  fibres.  The 
whitr  grlntinifi'rouH  iibrilfwi,  uu  tbe  contrary,  pMseas  vary  liille  ex(«n>it>ility 
or  olairticity. 

WIk-ii  a  {Hirtton  nf  HKiuoentiiiu  diiuIi%  \a  frettl  hy  iirolonged  boiliug  fv>ra 
th<!  n-mniiiil  of  gclBtiniliiroii*  fibrt«  mixed  iiji  wilh  ilio  velluw  claolic  inaU- 
rial,  tbs  Inll'.T  t«  limiul  on  cbemiail  tn-iiiineiit  to  yi«l(l  a  mibtiiaim  called 
tlattiti,  nhicli  very  clowly  nveinblts  [iruteid  matter  m  clemtDtarr  cotuno- 
sUton,  excvpt  llint  it  contain*  no  fulphur,  and  wbicli  yet  probably  diftera 
wid«ly  IVom  it  in  nntiirv. 

Conneclivo  tiwuc  Ibwi  con»xti>  of  a  matrix  of  iuexlciisiblc  in«la»tio  irhile 
navy  );GlatiiiifrrouH  tibrilUv,  ccmcnU-il  inm  bundlr*  (iht-  bundl»  Xitat^ 
arranKeil.  in  Io<«o  coiiiiecitrc  tiAtic,  in  irregular  mt^hunrlci)  nilli  which  are 
ttwociated  in  varyitii;  abundnncc  anastnnnMiiiig  euHcd  ypllow  clashc  tibrea, 
flud  auion^  which  arc  embedded  limnclirii  coniictivc  tietuc  ciirgnifcle!!.  I^U- 
ooejUs  aod  pluma  cells  are  itl«a  found  in  th«  raMbn  or  aroolie  of  the  dimIi- 
work.    We  may  oou-  r«lurn  to  the  striicttirc  of  the  b1ood<r«Mela. 

%  107.  (^tpUlarie*.     A  capillary  if,  iis  vc  wid  abttve.  a  tubular  psfsage 
liollotved  out  ID  counective  timue.     Without  e|)cc)ul  prejMralion  all  inat  can 
be  K«n  under  the  microscope  is  the  outline  of  the  wall 
(ni>.U.  of  tbe  capillarv,  shoirinj'  under  hi);h  powent  a  double 

\  \  contour. and  marked  with  oval  nuclei  which  arelodced 

in  the  wall  at  inU-rval».  and  which  project  aonieirOBt 
into  the  lumen  or  canni  of  the  vessel.  IF  iff.  51]  Wbea, 
however,  the  tis^'Ue  coutalninK  the  capillaries  u  treated 
vflih  a  weak  eoUiltou  of  silver  nitrate,  and  after  being 
thoroughlv  washed  b  exposed  to  light  the  wall  of  tho 
oapiUnry  U  seen  to  be  marke4l  uut  oy  thin  black  line* 
into  »pitidlc-«lm|)ed  areon,  da\-«ituling  into  each  other, 
and  mi  rrlaliil  lo  (lie  nuclei  in  the  wall,  that  each  nu- 
cleus occupie:<  about  lh<-  ocntrc  of  an  area.  Krom  thi> 
and  from  other  liicU  vrv  concludv  that  ihe  laipillary 
wall  i»  built  of  Hal  luxifnrm  nucleated  plates  cemented 
together  at  their  cdsrs  by  some  cement  subalancc^ 
which  more  readily  abaorbs  and  retains  silver  nitrate 
than  do  the  plales  themselves,  and  hence  aAer  irtAt* 
mcni  uilh  llic  silver  salt  shows  in  tbe  form  of  black 
lines  the  silver  which  has  been  absorbed,  and  suddenly 
reduced.  Kach  plale  is  u  Halteoed  nucleated  c«ll.  the 
cell  body  of  whicn,  except  ti)r  a  remnant  of  undiilV-rni- 
tialed  protoplasm  round  ihe  nucleus,  haa  becuimr  con- 
vened into  transpareiU.  diOereotiated  material.  Sinoo 
the  cells,  except  )br  the  minimum  of  ocnK-ni  i>uhi>ianoe 
botwceti  tlicm,  are  in  dose  coiilaet  with  each  i>iher, 
wcmiglit  Rpeakof  them  asformiiifc  ana'pitliutium  ;  but 
on  account  of  their  cell  InHly  boiut;  reducnl  to  a  more 
plate,and(>tiaecountof  their  connection  both  hv  origin 
and  nature  with  mcNoblaHic  conncctivp  ti<vtiv  corpua- 
IHm,  it  is  convenient  to  speak  "f  ihi-m  ns  rpH/irlioid  a-Uf  or  plnto^  They  are 
■pmelimes  R|>okcn  of  as  rndothrliat  cells  or  plates.  In  a  small  capillary  tbe 
widtli  of  one  of  these  epithelioid  ))lal<«  al  its  widest  part,  where  Iho  nucleus 
lies,  may  be  of  nearly  the  wtmc  size  ns  the  rircumfervncc  of  the  even-distended 
capillary  ;  the  cells  consequent!  v  arc  placed  not  side  by  side,  but  more  or  len 
altarnate  with  each  other,  and  their  nuclei  priiject  alternately  into  the  liinien 
of  the  TCiML    The  larger  capillaric»  may,  however,  be  su  wide  that  two  or 


*- 


'fs 


\V 


Hratimiiror  *  uvi>r.i- 
nu.    triKii    Tkutub't 
Hfia  Sonmon  ft    Ni- 
laiTS  uj'  SiLvn. 
d.  CMt.    >.  Thdr  nil- 


rBATORKS  or  TASCOLAR   APPARATDS. 


177 


> 


i-ellii  lie  iikore  or  l^se  abrcasL    OuUide  the  CKiHtlnrv,  U'liich  is  tbus 

ft  Ikto  whJ  dclicale  menilinine.  a  m«re  {latcliwork  of  thin  epithelioid  cells 

OMBottal  toK«tJ»or,  i»  alnava  fuunil  tk  certain  nniouiit  of  couuective  tintiue, 

tlw  wall  of  Uie  capillar/  furniing  at  places  jkan  of  llie  witllfl  >if  the  lymph- 

boUiM  eannective  tiwiieqncta,  aiid  at  oltier  places  Imiujj  uiiitt^<)  by  cetui^nl 

aataml  tn  the  buixllt*,  bands,  or  alwets  of  tbe  same  coiiitcciive  lusuc.    Not 

itaf>«|ijmtly,  in   youuii;  iimmka,  branched  counective  lisnne  c(trpu»c:les   He 

•i[*ia  utd  rtntiraor  u  CAj^llBrv,  fonw  uf  tW  i>ri>cesiet  of  the  ckII  beiiij;  sitai'lied 

U>  tho  KUlaidi,'  of  tbc  rpitlx'liiiid  iilaliv  of  t^i>  eit[tillary.    Kvcii  in  llic  rapilla- 

of  aocb  a  Uiatie  as  niuscle,  tW  ni-lwurk  i>f  ciipillaric:!  i-nilirii<-iii^  a  nius- 

flbra  b  alwavR  surmuixli-d  by  a  crtAiti  ihuii^h  sonictitnrg'  a  miiall 

•MMai  aaW  of  nmm-clive  linue ;  iiidwd,  nhcrcver  capiltnntii  nin.  tliey  nro 

aOMatpaainl.  mt  wv  haw  wiid,  by  coonertivp  tiiwu«,  to  itint  overywheru  all 

0**r  lb*?  b«dy  Uie  blmxJ  in  tbc  capillnry  i«  «c|ii>riit«d  frnin  the  lymph  in  th« 

tfttcr*  of  the  c>onnectivo  tissue  br  iiolhiii)f  more  thati  the  oiceetli ugly  thin 

Wiw  of  the  cemented  epithelioid  plates,     ll  must  he  added,  however,  lliat 

th*  ifiaees  in  the  cuoDeclivo  tbsue  are  lbeim>elvca  fometimefl  lined  by  similar 

wuliclioiii  platea,  of  which  we  slinll  have  to  treftt  in  sfteakiog  of  the  lym- 

|M(KB,  ttt  that  in  placw  tbe  partition  between  tlw  blood  and  tlieM  lymph 

mar  Im'  a  double  one,  aod  consbt  of  two  layen  of  thin  plut«t. 

Ife  KDJ  ciiae,  howovcr,  the  [lartitJon  U  an  exceexliii^-ly  thin  one.  and  no  |ior- 

nniMi  that  it  alhm-s  nii  Hile<iiiately  rapid  iuterchau)^  of  inntenul  lietwi.i'n 

lWbto«lai>d  the  lymph.     As  wu  ithall  pri-rt-'ntly  M^e.  not  ufily  tluid.t— that 

ii^mtten  in  wliilioo — arc  able  to  piura  thr»U);h  the  riurtitiou  into  the  lymph, 

UtinUct  eurpusetm  Wh  rod  wid  while,  ea|>ecially  tlie  latter  may,  in  ovrtain 

cinanMUnc**.  niabf  Iheir  way  thniugh,  and  m>  paae  from  the  inurior  of  tho 

■fiBatr  IdIo  the  Irniph  »pace«  ixitxide.     It  is  probable,  however,  that  then 

mkt  ueir  way  chivtly.  if  not  cxvlitiiirelv.  through  the  cement  lines,  and 

■IMJally  at  ihe  point  where  the  <«inenl  linc»  of  three  or  more  cells  meat 

(DMlier,  and  where  the  cement  Fub»ljiDc«  exists  in  larger  amount  than  elafr- 

TW  «te  of  (be  capillaries  is  variable.  In  some  regions  of  tbe  bodj,  for 
OHUiiet,  in  the  Iudk^.  the  capillaries  arc,  on  the  whulo,  wider  than  in  other 
nti'ias,  fur  iiRiaucc.  the  xkin  ;  and  all  the  minute  vessels  joining  arteriea  to 
wisi  and  pfwwMint;  the  structural  featurra  jiist  described — that  ia,  bdag 
mil!  spill  arte* — will  out  always  have  the  $au>e  size,  even  iu  the  rante  region 
<l  (W  Dody ;  tbe  artrrr  may  gire  rise  to  Uiffe  capillaries  which  branch  into 
•■all  QBpiUnrMM,  and  these  iniir  again  join  into  lar^ecapillariee  before  uniting 
tifctn  raiiH.  Thus  one  i-api^larr  outy  be  so  narrow  tnut  a  single  (mamma- 
Su)  red  oorpuaclo  passe*  through  it  with  diliieulty,  whereas  anuliier  vapiil- 
hr?  may  he  ttid*  enough  to  afford  rotim  for  two  or  three  such  corpuscle*  to 
tr-  i>i.     Itt-viiles  (hi*,  ilu'  same  capillary,  may,  in  Ihe  living  boily, 

ii  i:ii  frxiii  time  m  time.     At  one  mi>meni,  as  when  (lie  etiininoe  on 

tt  utrrwl  rii\r  is  blm-kcl,  or  when  liIrnMl.  fur  Home  mason  or  another,  ceasea 
lalow  iDt>>  it.  (he  ciiiiilhirv  may  Ik-  i.-nipty  and  eollaiwed,  its  walU  in  eon- 
tut  and  its  lumen  nholishol  or  nciirlr  so;  and,  in  liawes  taken  from  ihc 
■bbl  budy  and  preparwl  for  niicmtcoitical  examination,  tbe  capillaries  are 
smmlly  thu«  cm|>(y  of  blood  and  (-iilliiji*"),  »i  (hat  they  can  be  seen  with 
etCnilty,  appeanuK  as  (hoy  then  do  as  ulinu»t  mere  tine*  with  swellingd  at 
>iu«rvalii  comspoiulini;  Ut  tlie  nuclei  of  iho  eoostituoiK  celU,  At  anotbar 
(IBS.  as  when  blood  is  flowing  into  it  a(  high  prwetm-.  the  capillary  may  bo 
viddy  diitnidfi).  In  the  variations  in  calibre,  the  walls  of  the  capillary 
fJsj  ■  paHTv  |iart :  the  maleriul  of  the  eirithclioid  phites  is  extcnsihk*,  and 
lis  fnman  of  tho  bl<Kid  within  the  capillary  diBlen4ls  the  wa)U,  aotl  the 
~  baing  also  elastic,  tbe  walls  shrink  and  colUpae  when  the  prewire 

13 


ITS 


TUB    VASCULAB    UBCUANI3U. 


ia  itnovcd.  being  iiMwtcf)  in  this  by  thv  prMsurc  oT  \ht  lymph  in  (he  ipM«» 
OUlnd«  tlic  cnptUtiry.  ItnC  iHifidcs  thi»,  in  i>  vnung  nniinnl,  itt  all  wcntf,  Um 
citpillnry  wnll  is,  to  »  oi^rltiiii  cxtpni,  cvnirnuiito ;  thi:  <:{utbelioid  ci-Ili',  which 
ihtrii  a[>|M-nr  lo  cont«iii  a  liti't'O  imiutinc  of  iimliftl-ienlinUxl  protoplaixii.  »n-m 
able,  iiii()<.T  the  intlticnco  tif  Mliiiiiili.  to  vhati^  tlirir  fiimi.  piiMiii);  t'mni  n 
loiigirr  aikI  narrower  nhape  lo  a  fllvirtcr  and  hruiidpr  otic,  and  (nii»  iiiHucndng 
ih?  calibre  of  the  iiibc  ot*  whioh  lli«y  Ibnn  the  weiIIh.  How  far  f\ich  an  aclivv 
chaii^'c  of  form  lakes  place  in  the  cnpillariot  uf  the  adult  body  haa  not  yet 
been  <letiiiilclv  determiited. 

Tlie  ^iruQlure  of  the  eapiDary  then  seems  adapted  lo  two  ends-  In  tke 
firel  place,  ilu  walla  lieiiin  penueablu  iire  adapted  for  cnrryioK  out  that  im- 
portant iuterfhaiixc  between  the  blond  uud  liaatie.  which,  aa  we  have  more 
than  nuoe  Mid,  laltcs  place  uliuiwt  oxduMvely  in  the  cunillary  rejijioiM.  In 
tbcsec-ond  pluru,  the  extenBibiltiyundelHAtiiity  nf  lut  wallit  permit  it  to  adapt 
■U  ealibru  lu  tho  amomit  ami  r>iri.-e  witli  which  the  bWd  ii>  llnwing  into  iu 

^  106.  Arlm^.  The  wall  nfmmintUi^  artrrtj,  i.  c,  nf  one  whiuh  imHHin  abuul 
to  breulc  up  inlu  capiliaricv,  and  which  i:<  •onieliniM  i^pokcn  of  iu>  an  (irtm'«t, 
coiuiitt*  uf  thtt  following  parts : 


(Ptd.  u. 


Pm-a. 


t' 


1,  ■twlkMlnfUTT ',  ^  Ummiaun  voaicl ;  3.  «sn«r  raiilllnnw :  4.  Hiier  cB|41l«tla  a.  Mruciurekio 
nmbniie  Mill  wlUi  waan  i>ii«lvl.  rt>[im(ntoll*e  o/  Ihe  tantca  vitliiu:  b,  uuold  of  Uie  biuku^t 
Mf»««IU;  I',  iiuckl  wlihlu  tlin  miiaII  artciy,  larbjti*  apiionaiiillig  lo  ui  mdoUwlliuiii  A  nuclei  tu 

Fbl  ^— aiUU.  AaiEKT  Tn  SaoH  iiiK  V<iiiui-i  l.trt;iT!i  uuicii  I'DHi-itn  n*  IVauo.  ■,  tniiy 
tfetSmn  ;;ft.  InUmal  cImUi-  luuiD*;f.rJrp>ilaruiiuculnr  fibrrt  ariliemlil>ll«ri>at:it.  ib«vonn*ctlt>*- 
danaiHUHrcpM— tunica  •dTnillU>iLuiM«'«i«»>Mi'iv*.  «!''■■  b?  iSUiliiuif,) 


There  ia  within  n  lining  of  fnHifono  epithelioid  oelts.  very  eimil»r  to  thnw 
of  a  capillary  and  aimilarly  ccmmted  together  into  a  membrane  t^'>^-  S-]- 


lirac  (liBiticicr  of  tbne  fueiform  cells,  irhich  «re  Mmoiimee  very  narrow, 

!■  pIacwT  luirnlli-l  in  tlii!  axis  of  tlio  artny. 

Oauitit'  tbu>  ipiilii-lHiiil  liniiif;  uoiaea  *  iliin  trenitpBrent  aM-ueturelew  or 

finely  lihrillali'd  mrmhmiie.  Aeeii  tii  an  itpticfti  or  other  secti'm  of  lh«  ftttm* 
_  a*  a  mrrc  liiir,  wliirli  ivrviw  hi>  a  fiu|>|x>rlii)i;  m«tu)>r«n«,  baiaciDcnl  inciubranc, 
■  W  mtTfirtna  finrpria,  for  i1m>  «pi(lt«lHii(l  velllt.  Tin*  inl-iDtiniiw  \*  similar  in 
^U^niiii->l  nnliin'  nncl  in  pmixiriin  In  tittt  olrurtii.'  fibnu  foiiiiil  in  con  inactive 
^flfair.  aoil  licniv  U  »|Kik<'n  of  an  the  tloMie  memhrnnc.  Tliv  f [lithi-ttoid  colli 
^^Sd  tW  clultc  fi>«ml>nin<-  t<ip?lh*r  arc  often  cfiukvn  of  m»  forming  tbo  inntr 

mtt  (ttmiVn  i'n(iui)  uf  thp  artrrr. 

IVi'ni)>|iril  inmaverwly  in  n  antn  or  Ipm  clutinctlj  wpirsl  manner  round 
lUi  iiibrr  niut,  and  imbedded  in  n  Kmiill  c^uanlily  ol  eonnective  tiwue.  tie  a 
nitnber  <if  [ilaiii  musetilnr  fibre*.  nrrnni.'''<l  id  the  i>malle«l  arteries  in  a  einijle 
Uftr,  in  the  larger  but  itill  »iiiiil1  iiitcrie*  in  mora  than  one  layer,  liiia 
iwtna  in  tkese  arteriea  ihe  mUlille  or  niiisctibir  eoaL  ( tiini'iM  mMia).  Outude 
Am  nuMuhir  coat  come*  the  external  eoat  {lunifu  esiinui)  conaiMing  of  con- 
nctiva  liHue  ilie  buudlee  of  which  are  disposed  for  the  moat  pari  I'>n}{ituili- 
DillT  And  contain  a  nitmlior  uf  eunne«tive-tinue  corpiudea  and  u  relatively 
brp  number  of  elsHtic  librra.  This  outer  cuat  ia  continuouH  with  the  coa- 
Mtivr-ltMue  \yiA  in  which  the  artery  lies. 

A  uioule  sKery  then  dilfeni  from  a  eapillary.  In  ihi?  ihickncw  of  lUt  walls 
vkmhr  (be  pertneabilitv  tu  cbaraetvrjstie  uf  the  cupillary  i^  tt>  u  gn-at  extent 
hH.  ia  the  itintiuet  development  of  elulic  elemeuti,  tbc!  Gla*l<e  rocmbranr  of 
A«iutf  coat,  and  the  clastie  librvn  uf  the  outer  eoat,  vhervhy  eliulic  >juali- 
ti«  wt  definitely  ntureil  tu  the  walk  of  the  veinel.  and  laHlv  and  chiefly  by 
iWMtmiee  >4  diriincl  muscular  eleroento.  It  ia  obvioiix,  that  while  by  tho 
<lnwfiMPl  of  ela)>ltc  clenx-'ntii,  pimve  rlinngM  of  calibre  have  a  grealer 
mpttkan  in  the  capillary,  active  ehan|.'c«  in  calibte,  irhich  in  tbe  capil* 
jnrm  al  best  doubtliil.  arc  ujsured  to  the  artery  by  llie  muscular  elementiL 
Hmi  these  trnnsvenbely  digpnoed  muscular  fibres  contract,  they  must  narrow 
ih  calibre  of  ihc  artery  and  may  do  that  against  even  rery  eonsiderable 
tWraal  prc»ure:  when  tliey  relax,  Ihey  allow  the  internal  preaaure  which 
■naiM.  ut  diHieiid  ihe  veuel  and  tenipomrily  to  increase  the  calibre. 

nbeii  Ruch  i>  Hmall  anery  break*  up  iniu  capillanftt  tlie  niuiicular  fibrca 
uA  flattie  nicmbrarie  dtwopear,  the  remnant  uf  the  niiMculnr  coal  being 
noMiBtit  coiilinueil  fi-r  a  shorl  diittunce  in  thi-  furm  of  a  single  libri'  stnig> 
(liwtD  a  i>]iiml  fiu<hi"u  muud  the  artery  toward  tlie  capillary,  and  all  that 
altsii  the  epithelioid  lining  of  tlic  inner  coat  with  a  little  oonDcctive  tiMiie 
■•nnment  the  outer  coat. 

i  108.  Tha  toryer  artrritt  rcMinble  tbe  minute  arteries  in  to  far  that  their 
■dia  maj  h(>  cons>(lere<l  n*  eompoeed  of  Ihrre  voate,  but  rjich  of  \iuxe  coats 
iiif  •  miirv  itT  lew  ounplvx  nature,  and  the  minor  detail*  of  their  struc-ture 
ilh  in  dillrnrnt  artorie*. 

biMieh  an  artery  as  the  carotid  or  radial,  the  three  coats  have  the  fblEow- 
■jtmeral  characters  [Fig.  -MiJ. 

iW  inner  eoat  is  composed  of  a  lining  of  epitbeJioid  cells  resting  not  on  n 

■a^  delicate  basement  membrane,  but  on  an  elastic  layer  of  some  thick- 

>■.  I  iMWistilj||,  diielly  of  a  so-called  "  fenealrated  "  elantic  membrane  or  of 

M«  ihao  itne  ttich  ntembrane,  together  with  some  amount  at  fine  elastic 

laad  in  some  enses  at  all  events  a  small  uuBDtily  of  white  conneclive 

L    A  "  fen<-«trated  "  membrane  is  a  membrane  conipnewd  of  the  Mine 

am  a*  the  elimtic  fibres,  perforated  imeKidarly  with  bolea.  and  more  nr 

l^aarkvd  with  indicatioosol  fibrH;  it  may  be  reyanled  aa  a  felinork  of 

•latii:  fibn*.  fused  or  beaten  out,  as  it  were  in  a  UMrv  or  K-m  mmplete  mem- 

Wua.  BDina  of  Uw  meidm  of  llie  feltwork  remaining  us  **  fenestne "  and 


and       ^A 


180 


THE    TASOVi:.AR    MB0HAN18H. 


tncwof  thellbna  being  xtill  hfi.  Suc-li  ri-ncAlrkted  nciiibnats,  »ntnc  thick, 
•OIU4  thin,  occur  hut!)  in  tliv  iinK-r  niid  riiiil<ll(>  ooaCa  of  tho  Uw^r  url^rius ; 
Dti'l  ill  dm  iiini'T  cant,  ti»iinliy  iinmctiiitolr  iindpr  th«  e|>ilhvii<ml  lining,  ibei* 
is  in  niu«t  Inr^v  tirtvri««  n  vooNpicuoiis  mcmhrnun  of  tliis  kiiiJ,  sometimes  to 
thick  nit  tn  give  n  wry  distinct  iloubic  ojlline  in  mentions  of  the  arlcrr  even 
umlor  nioilernlc  powcre.  nrn«filh  this  there  tnny  be  other  eimilsr  fenestniied 
membrnncs,  or  u  felt  of  tinv  cl«tic  fibres  held  together  hf  a  very  siuall 
({iiiintily  of  white  coDOCctive  tiwue.  In  iho  norta,  and  in  some  other  arteiiee, 
tlie  cpitholioii)  mIU  rat  imraeilialQly  not  oa  an  elaatio  membrane  but  i>q  h 
thin  layer  of  eo-called  "  iiub-epiihelioid  *'  tteauc,  which  cun^isla  of  oi>iiii«ctivc- 
licBiie  cor|>u8f!e§  imbedded  in  a  homogeneous  or  very  faintly  6brilla(ed 
matrix  or  };round  eub^lam.'e. 

The  epUbelioid  <.-ella  are  diiposed  loni;itudiiiallr.  that  is,  with  ttieir  loi 
diiiiii^iers  parallel  to  the  Kxis  uf  the  artery,  and  a  similar  hmgiludia 
armtigi-ment  obtains  to  a  greater  or  \tss  cjttent  iu  the  undprlyiiic  elnitlir  ele- 
mentA.  When  utler  death  the  arteries,  emptied  of  bloml.  bei-ome  narrowed 
or  cotutric'ted  by  the  r-oii  tract  ion  of  the  muKCiilar  element  of  the  middio 
colli,  lh«  inner  coat  is  throwu  into  longitudinal  wrinkle*  or  fotdi.  M  UiKl  io 
tniiiitvi-rr>u  necliuiiM  of  an  artery  in  thin  condition  the  inner  (wal  hai  •  dianwy 
t«riiitic  ptiekereil  appejirance. 

The  inner  cout  in  .lomewhat  delicate,  and  eunily  torn,  »t  that  in  injiirin  to 
arlcriiv,  an  ndieu  nn  artery  in  forcibly  ligatured,  it  in  ant  to  be  brokeJi. 

The  middle  ctmt,  which  in  gcnernlly  ninny  time*  tnick«r  than  the  inner 
coat,  <im»ixl»  of  clnNtic  Inyere  an<l  mn»cruiar  htyer*  plnircd  in  more  or  lem 
regular  alternation.  The  muscular  biyert  L-nnsist  of  band*  of  plain  muscular 
libn»  placed  tniiisvenely  and  united  together  by  a  very  itmiill  amount  of 
white  connective  tiseuc.  The  ela«tic  layer*  eonsiot  of  somcwhnl  (bick  fenes- 
trated membranes  or  of  feltworks  of  elastic  fibres  ninning  on  the  whole 
loDfpludinally,  but  not  uufiequenlly  more  or  leas  ublii^uely;  these  are  aUo 
bound  tof^ther  by  a  aiuall  quaulity  of  while  coniiectire  tiineue. 

The  ou[«r  coat  eonaista  of  feltworks  of  eltietic  fibres,  or  in  fome  iostancee 
of  ftDeelraied  inembrauee,  diftpueed  chiefly  lougitiidiDally,  and  aeparated  by 
buodlee  of  ordinary  white  connective  tUieue,  which  become  more  and  more 
Itredominant  in  the  outer  portions  of  the  coat.  In  many  arteriea  bund*  of 
j>)uin  mn!>eulHr  fihrr»  ore  pre!<ent  in  this  coat  also,  and  then  run  for  the  moat 
\»n  but  not  excliixively  in  a  longitiiiliual  ilireetiuu. 

Bloodvci«iel»  for  the  noun.ihmeiit  of  the  tiiniie  of  the  walls  (mm  wuorun) 
are  procrnt  in  the  larger  arterieii,  beiug  iu<i»t  abundant  in  tlie  outer  cont,  but 
penotraling  for  »ome  dint luice  into  the  middle  coat.  Nervex,  eonaia^ngcbioBy 
of  noD-iDcdullat<t<l  fibre*,  may  he  iraired  through  ihe  outer  coat  into  the 
middle  coat  wberv  they  apptrar  to  end  in  connection  wtib  the  muscular  libree. 

Lastiv,  in  iJie  case  <if  mwt  larger  nrteritv,  the  bed  of  eonncotivc  tinsue  lO 
which  the  artery  run*,  t;  fomicil  into  n  more  or  lew  distinct  shnith.  In  this 
•bealh,  tlic  white  connective  tiiwic  is  much  more  abundant  than  are  tbe 
rellow  elastic  elements,  so  thnt  the  sh<-iith  i'  far  lens  clastic  than  the  artery. 
Hence,  when  an  artery  and  it'  sheath  are  cooi|dctely  cut  acroe*,  (hb  artery 
is,  bv  elastic  shrioking.  retracted  within  its  sheath. 

Tlie  nut  important  structural  features  of  a  largo  artery  may  then  be 
Bummed  up,  by  saying  that  the  artery  conMsle  of  a  thin  inuer  cuat  onosisling 
of  an  eiiitheliind  lining  reeling  on  an  elastic  basia  of  no  ooutipicuoiu  thick- 
nan,  of  a  thick  mi<ldji'!  coat  consisting  partly  of  muscular  fihrw  disposed  for 
^e  moat  part  tranHvcrxely,  and  partly  of  stout  elaatie  elemeutA,  tliia  coat 
beEog  the  tliiektat  and  must  im|>oriant  of  all  three  coats,  and  of  an  outer 
coat  of  variable  Ihieknec^  cou^intinK  chiL.'fly  of  elastic  eleueota  ioiermixod 
with  an  increasing  aiuouiit  uf  white  connective  tissue. 


rSATCRSS   OF    VASCULAR    APPARATUS. 


181 


k 


I 


rteriM  powow  the  uhore  fealum.-    It  n>aj  furthpr  he  «ai(i,  that  as  n 

nile  lli«  Minfctilnr  ctemeni  bean  a  lurger  [Toiwrtion  lu  the  clastic 

io  the  (lualler  tliao  in  the  larger  arterif«,  that  is  to  eav.  (he  itiiialUr 

Otarin  kn  more  cboapicuoii^lv  museular.  aod  the  lar^r  arteries  more  coii- 

il^ODCNMljr  elastic    It  rauat  W  n?iiieiiihered,  huwrever.  that  the  several  arteries 

vf  IImj  boily  difler  coiisidenihly  in  minor  ledlures.  siich  as  llie  relative  die- 

poattiun  ftnd  UDount  of  tuuscttlar  aud  eluiic  eieiuenu  in  the  middle  coat, 

tlM  amount  of  miwcular  ibsue  in  the  outer  coal,  and  Die  proportion  of  white 

ovavctivo  Umup  prcxent  and  the  like;  iu  llie  aorta  Tor  imtanee,  a  vonMder< 

able  quantUjr  of  while  n>nti*«iivo  tiMiu«  U  pre*eiii  in  (be  middle  and,  indeed, 

b  ill*  laner  coal,  a»  well  tu  i»  the  outer  coat.     I-eavJog  the*e  (unaller  dilfer- 

neca  on  one  aide  wo  may  tmj.  that  while  all  thnM^  couih,  but  cw])edBlly  Um 

teporUDl  middI<^  coat,  ooDtribute  to  kIvc-  nii  nrtcry  it»  chflmclcrintic  elaHtio 

■Mlkiw.  by  virtiH-  nf  which  it  expands  remlily  under  iiilcriiiil  |>r(«.-<iire,  and 

■riab  again  wbvo  the  pm»tiro  w  rvmoved,  it  i*  (h«  niiddk  coiK  which  1>y 

■laMef  lira  abtiiidnnt  circularly  dispoced  inu^ciilur  tihriv,  now  through  tliv 

(■inrtioii  »{  thow  tihres  narrows  and  conslricti!.  now  through  their  rclaxa- 

Am  famiilfl  thf  widening  of  the  vessel.     The  iinporlaDce  ut  ihe  inner  cunt 

a  fmbably  cenlrMl  in  the  epithelioid  lining ;  in  ircatine  of  blood  (^  'i'i)  we 

««  RMon  to  think  that  the  bloodvesets  exerted  a  mariied,  though  obscure 

iilMMe  oo  tfae  blood  BtreaniinK  lhrotif;h  them ;  that  inlluence  in  all  proba- 

tA;  IB  eflteied  by  ihe  e[Hthcli<)id  nelk     The  elastic  elements  of  the  inner 

(Ml  are  pnbably  chiefly  of  value  in  jwnnittiuK  this  coat  to  follow  the 

iImm  of  the  nxkre  important  middle  coal.    The  outer  coat  while  increasing 

lb*  wutic  power  of  Ihe  whole  vewel,  in  especially  useful,  by  means  of  iu 

nail  blond vesae Is.  in  (-onveying  nourisbmeut  to  the  middle  cuut. 

illO.  The  m'iM.  Thc)«  vary  in  diflVrent  purm  of  the  itody  to  very 
■iJily,  that  it  is  difficult  to  eive  a  gcneml  dncription  »f  strurlurc  suitable 
bxDvnnsi  It  mav  Ih-  ui«l,  huwevvr,  ihal  ihry  dilTer  from  arteries  in  having 
Wtth  tfainnrr  walls,  and  in  ihusc  walls  containing  rclnlively  much  more 
■Ut*  otiDDeclive  litduc  and  much  lew  yellow  elastic  tissue. 

A  large  vein  [kdvcsbcs  like  an  arlcry  an  inner  coat  consisting  of  an  epitho- 
M  lining,  the  celts  of  which  are  eliorter  and  broader  than  iu  the  cornv 

riding  artery,  resting  on  an  elastic  basis,  which  is  leu  conspicuous  than  in 
EMTMpoodiiig  artery,  and  conaiMB  of  a  tine  feltwork  of  tihrw  rather  than 
afaulrated  menibraue,  and  ci>niain«  mure  white  connective  lifsue. 

laa  medium  med  vein  auch  as  the  sikphena  vein  it  is  porsihle  Io  disljn- 
|iUi  outside  the  inner  coal,  a  middle  and  an  outer  coaL  The  former 
eaMUof  white  conueetive  tiMiue.  with  a  scanty  supply  of  elaalio  Sbrea;  il 
Hnuias,  aometimea  iu  couMdeiable  ijunntiiy,  plain  rotiscular  6hres,  the 
kmdka  nf  which  form  a  meabwurk,  with  the  m«»hep  disposed  for  the  iDnu 
fan  trannertely.  The  latter  consists  also  of  white  coiiucvtivc  ti«*ue  with 
■W  elastic  fibrta  running  lnOfritudinally  and  <)hli<|Uely,  plain  Ku»c»lar 
flms  being  sonietiniM  |irtM-»l  and  wlien  prevent  diajHMNHl  chKfly  in  a  longi- 
laiim,\  direction.  Small  vasii  vusonim  arc  pro«util  in  the  outer  ouat  and 
Ottnd  into  the  middle  eOBL  In  many  large  vein*  lliero  in  no  sharp  diMinc- 
lisB  betwcvn  a  middle  and  ouir'r  i-oai ;  the  uhnlc  wrapping  round  the  inner 
Mt  cennile  of  white  connivlivc  with  n  vniiublc  (|uautily  of  clastic  liHUc, 
ud  i^f  muscular  fihre*  which  luu  chiedy  longitudiunlly  or  obli>|ucly  and 
•kick  may  be  very  scanty,  or  vhicb  as  in  the  vena  portie  may  be  abuitdant. 
TW  Mructure  of  the  v«'ins  iu  fact  varies  very  widely;  on  the  wlmle  tl^y 
Hy  be  said  to  be  cliennels.  the  walls  of  which  are  elastic  enough  to  adapt 
iMMlrcs  to  considerable  variations  in  tlie  ()uaiitiiy  of  blood  passbg  ihrtiugh 
Iha,  wilbout  poasewiDg,  as  do  the  arteries,  a  great  store  of  elaMk  ]H>uer  to 
■*■!  fTtat  variations  in  prcuure.  and  which  are  not  so  uniformly  muscular 


182 


THK    VAHCULAK    MKCHANISM, 


and  ooiitractil«  ax  nre  tlie  iirteri(!!'.  -  And  we  ahull  see  Utnt  this  [:«iierul  char* 
aoter  uf  paaaive  channels  is  adapted  tu  the  work  which  iht.-  vuiti«  Imve  (o  do. 
Tht*  (:«Dcral  chai'acl«r,  however,  U  modified  io  certain  situntiuii*  (o  m«et 
purtieiiitir  wanls ;  tbu!>  while  the  vein4  of  the  bones  and  of  ihi:  hriiiu  are 
devtiM  of  mtiituuiar  fibres,  uthera  such  m  tlie  v<-rin  |>i)rl:i'  mny  be  very  niuv 
I'ular;  and  in  .■niriie  veioH  such  iio  llia-x;  iif  th«  cxtri'tiiitic^  ii  c'l.invtdcrahk 
<(ijHiilitv  tif  eliL->ti<'  liHiio  io  ]ire>wDt. 

A  minutK  vfin  jiint  einergiii){  I'runi  i-a^iitlikrics  dill'ors  very  litllv  from  an 
artery  of  i.-iirfV9piiiiding  siw;  it  is  of  riiiJivr  wider  bora,  hiu  ikcidvdly  I(m 
muMciiIar  and  vluvtic  (i#iio,  and  ihn  c pillmlioid  rails  arc  shorter  and  broader. 

Many  veins,  eciiennlly  thosv  of  (he  limbs,  are  providi;!)  witli  valves  [Fin. 
&i  ami  'io\.  which  arc  pouch-like  folds  of  the  inner  coni,  the  muulh  of  we 
pouch  looking  away  from  the  uipillnries  toward  the  heart.  The  wall  of  each 
valve  cunKii^ts  ofa  fining  of  cpilhi-lioid  colls  uii  the  inside  and  on  the  outside, 
and  bcCweoD  the  two  a  Inycr  of  while  connective  tissue  sirenf^chened  with  a 
few  elastic  libres  and  somewhat  thicker  than  the  connective-tissue  baeis  of 
the  epithelioid  lining  of  lUe  veins  geDerally.  The  valves  may  occur  sin^^l/ 
or  may  lie  iw»  or  even  three  abreast.  The  veins  of  the  viscera,  those  oftba 
cenlml  nervous  system  and  lU  membraiiM,  aad  of  the  boDed,  do  not  poMcaa 
valves. 


TimvtTii  VjLTisorRK-  Alter  Dalton-I 


lattlac  lilt  t9y  laWnl  rbaanel. 


i)it>wm  of  Mend 
AMr  Dil.TOW.] 


SUl.  The  details  of  the  Alructni-i-  <if  the  fiifi^uliar  muscular  tis«i«  forming 
tbe  grcaU'r  part  of  the  heart  we  nhall  n^ierve  to  a  later  seotjon  :  but  we  may 
here  sar  that  the  iiilerior  of  thf  heart  ia  lined  with  a  membrane  (frido- 
Mftiiwwi)  ciirrCBpiindinK  to  the  innur  i-oat  of  the  bloodvessels,  and  consistioK 
of  u  lavcr  i)f  epithelioid  cells,  which,  however,  are  shorter  and  broader  than 
in  (he  Moodvntwls.  being  polygonal  rather  than  fuHifurm,  resting  on  a  con- 
nective tissue  basin  in  wbiob  are  present  elastic  fibres  and  in  places  plain 
muscular  fibres. 

The  valves  of  the  heart,  like  thow-  of  the  vein^-.  arc  liilds  of  (his  lining 
roCtnbraae.  sirenglhcncil  by  a  cmatderablc  development  or(<onnectivc  tisane. 
In  (he  middle  of  tbe  ihin  frw  border  of  each  of  the  srmilunar  valves  of  (he 
aorUi  and  pulmonsn-  iirtcry  biiiidlefl  of  this  connective  liKiiie,  meeting 
(ogMher,  are  mixed  with  i-artili^  cells  to  form  a  small  nodule  of  flbro- 
carlilaice  called  the  rorfmi  ar'intii. 

In  the  auriculovenlricolar  valve*  muiiL-ular  Bbres  pass  in  among  the  ooo- 
neelive  ttwue  fir  sonw  liulc  distance  from  the  attached  border. 

In  one  mipect  the  endocardium  dijfont  from  the  inner  coat  of  tbe  Idood- 
reseebt;  the  conneeiive  (issue  in  it  licar*  bloodvea^ela  and  lytu{diatira.     In 


rtATintss  or  vascular  APi-AKATrs.  183 

tbfOM  nf  ihci  auriculo- ventricular  t»1vm  littat  lilondvcBeb  of  ibo  tad<h 
ariiun  irAVnno  the  whole  ralve,  but  in  Uiq  caae  of  Utc  setnlluiiiir  valvw 
•up  thort  w-*r  lh<'  Atutdwd  bonier,  m  that  tlic  greater  purt  ii)'  tbc  vuItv  ii 
MwdtMk 

J/inn   t'raturf*  ef  the  Apparalut, 

ills.  W«  IDB7  Di>«  raw*  briefly  in  r<>vi»w  mime  nf  the  mnin  fMtunw  of 
lU  Mvuttl  pans  of  toe  vn»niliir  appiimlui,  heart,  nrtcriM.  veinc,  aad 
ounUarin. 

The  heart  ta  n  niUHiilnr  {>iim|>— tbat  is,  a  pump  th«  forcv  of  whnw  Urokw 
pMpplinl  by  the  iTininu'tion  of  muKtilar  fibres  nnrltin];  inlennitleolly,  the 
■trans  bchi):  repvalcit  n>  many  tim«s  (in  iiiaii  about  T'i  timea)  a  mioute- 
[1  ii  an  ron^ruclr*!  ami  funitshed  wilh  valvea  in  such  a  way  that  al  each 
itn>ki  il  ilrives  a  ceriaiu  iiuanlity  uf  bloMi  with  a  certain  force  and  a  certain 
a|>idity  frwu  the  left  wniriclp  inro  the  aorta  and  so  ini<>  ilie  arlerio*,  receiv- 
b|;durio|;  the  stroke  and  the  interval  lielwi-cn  that  dtnike  and  the  next  the 
anrquHUtily  of  hlouil  t'mni  ihe  veius  into  ihe  ri([tit  auricle.  We  omit  for 
ani'licily'!)  take  the  |H)lm<>tinry  circ^uluiton  by  wliii^h  the  aarae  mianlity  of 
Um  k  driven  at  the  llI^tkc  fnim  thu  ri^ilit  vciUnde  into  the  lunpt  and 
itciivtd  into  the  Ittl  nuHclc.  Tlit.-  rliyihra  of  the  lieiit.  thai  U  the  fre^iiiency 
of  NpMilku)  of  the  alr»ke).  aod  tin.-  cliaracter9<  t>T  each  heal  or  «trok«,  are 
drinmiaed  by  chanxv*  lakinj:  pinoc  in  the  tuMum  nf  the  heart  itMlf,  thouf^b 
tlvi  air  aW  tiitlurnof^l  by  cauMs  uorkiiit:  from  witboitL 

Vtf  •rli-riv*  tin  tulws,  with  rctattvelv  :<toul  uhIIk.  bninching  from  the 
Mfta  all  ovfrr  the  body.  The  (tonnliiulion  of  tbi-ir  udIIh.  ax  n'C  have  rttfo. 
•pdatly  of  the  rDiddleGnul,givi,w  the  ancric*  two  client  propi^rliea.  In 
ibtlini  plaor  they  an-  tfry  r/'utie,  in  thi-  iK-nw  thitl  ihcy  will  mrvlcb  rrwlily, 
koih  IfDj^hwaVi  and  eroaswtae,  when  pulled,  niKt  return  nuulily  to  their 
fcmvr  aize  and  abape  vhen  ibe  (hiU  is  taken  ofl".  If  fluid  he  driven  into  one 
foJ  uf  a  piece  of  artery,  the  other  end  of  which  is  lied,  the  arierr  will  swell 
oai  til  B  very  |;reet  extenl,  hut  returo  immediately  to  il»  former  calibre  when 
ihtlaid  ia  let  out.  'I1ib  elufiiciiy  is.  m  v«  have  aeen,  chiefly  due  to  ilie 
flMiie  eJrmeuta  in  the  ooatit.  elniuic  Diembranea  and  leltworks,  but  the  miu- 
nilnibns,  being  ibenuelvee  abn  elastic,  conlrthule  to  the  result.  By  reuou 
rf  Iblr  MMOiIiig  Hich  stout,  elastic  walls  ibi?  nrteriw  when  empty  do  not 
MiDipw,  iKit  ntmnin  iw  o|>eo  tulien.  In  the  second  place  tbe  nrli««.  by  virtue 
ifllitir  mutoiilar  elemeata,  are  ranlrarii/'- :  when  itimulaieil  either  diTts:llv, 
tthfmfiviag  an  elvctrio  or  ntcchtmical  •timuluit  lu  the  arterial  walla, or 
Wn(Uy,i)y  luoans  of  the  Mvcallml  vaxo-niotor  nenm,  which  we  A»\i  have 
la  Nady  prMvnlly,  the  urli-rii-a  shrink  in  calibm,  Uie  i-ircnlarly  dispowd 
"awllii'  fibtta  contract iuL'.  iiml  Mi,  in  proixirti'in  t4>  the  amount  of  tbcir 
iTClractMD,  Darroaiii);  ihnlumcn  or  bori'  of  the  vctvel.  The  i'»iiLmi'tiou  of 
■Wr  arterial  louacular  tibn'o,  like  that  of  ult  plain,  iion-nlriuUil  muM'iitar 
IIW.  b  eluw  and  l<mj;-<>->niinuvd.  with  a  long  Ut^'nt  jM^od.  ii^  com|iar«>l 
«uk  the  conlmction  of  Hkelrtnl  Mrialeil  mu-HMilnr  AbrvM.  Ovrin);  ta  thig 
■■nfair  eleim-nt  in  the  arierini  wall«.  the  calibre  of  an  artery  may  he  very 
tun*  or  very  wide,  or  in  an  intermediate  condition  hdmwo  the  two, 
adlbvr  very  nanuw  nor  very  wide,  according  aa  the  muscular  libru*  are  verv 
wuit  niniracted  or  not  conlrncted  at  all.  or  only  moderately  eonlrac*4Ml. 
V|  have  furllier  aeen  thai,  while  thi-  relative  projtortion  ol  eloMic  awl 
Maoplar  elvmenU  diHers  in  <lil1ereDl  arteries,  as  a  general  rule  the  clMli« 
iImhoU  predominate  in  (he  I arcer  arteries  and  the  tnuaoular  elentents  In 
(btmaller  ■itvrii-i.x  tliiU  ihc  I ■r>,'er  arteries  mav  be  spoken  of  a«  eniittcntly 
abitic,  or  a*  r«{><-<-ially  uveful  im  accKWint  of  tbeir  elastic  proMrlic:>.  and  tba 
Mnaltrr  artrriw  n»  eminently  muscular,  nr  lu  etpcciallj  useful  on  occiiunt  of 
thnr  iBuw;ular  pto|>t'rti<«.     Tbui,  in  the  minute  arteries  which  are  just  ^uaa- 


184 


THE    VASrCLAR    MECUAXISM. 


iog  into  C^IUrin  the  niiiKiilnr  i-iml,  though  ctiiii]inff()  nfton  of  n  single 
layer,  and  thst  •oinclimM  nn  imiH'rii^ot  imc,  of  miiiiciiliir  Itbrat,  in  ii  miicti 
Diore  (^ODHpictiftiiB  anil  imptirtjint  (mrt  of  thcnrlcrial  wnlllhaii  tlmt  furniKhcd 
by  th«  otnxtic  <■!(.■  iiK-iiu. 

The  arttirw*  brnmhing  out  fn>m  n  nitiglc  Hurln  down  m  niullitiidinou* 
capillarir*  in  murty  i-vi-ry  pnri  of  the  body  diminish  in  htire  m  ll»cy  ilivi<)c. 
Whera  un  nrlvry  dividt^  into  two  or  gives  olT  n  branch,  though  the  bore  of 
ODch  division  i*  len  thuii  thiil  of  the  am-ry  Ixtfore  the  division  or  brandiiog. 
the  two  together  nr(>  grcntcr:  th»t  is  to  say,  the  united  wclioDal  area  of  tbe 
branehes  is  greater  Uian  the  wctional  area  of  the  trunk.  Henoe.  tbe  aec- 
lional  area  of  the  arterial  bed  through  uhicb  tbe  blood  Aova  goa  on  iocrcM- 
iug  frDEu  tbenorla  tolhecapillariee.  If  all  the  artorinl  braochcv  were  throwa 
together  into  one  channel,  this  would  lorm  a  hollow  cone  with  iu  apex  at 
the  itoria  and  its  base  at  the  capillaries.  The  united  sectional  area  of  tlte 
capillnriea  may  be  taken  as  several  hundred  times  that  of  the  tectimial  area 
of  tbe  aorta,  ho  greatly  duen  tht.-  arterial  bed  widen  out. 

Tbe  capillariee  arv^  channels  i>f  variubk'  but  e:(«'ediiigly  vinali  utA.  Tlw 
thin  !>heet  of  cemented  epithelioid  |)hiti.i>  which  fonn.n  the  only  irnll  of  a 
cnpillani'  is  elaitic.  permitting  thi^  rhannel  ofli'nil  by  thr  Miino  capillary  to 
dilfcr  much  id  width  at  iliflt-ri-nt  tiincN  to  widen  whun  hluiMl  and  blood* 
corpu^tclcn  ar«!  being  pri-NX-d  through  it.  and  to  narrow  again  wben  the 
prr«8un?  is  loncned  or  cut  olf.  I'hc  Minic  thin  sheet  porniitt  wntor  and  sub- 
sta»i;ps,  including  canes,  in  solution  to  pics  through  il«elf  from  the  blt>od  Lo 
the  ti«ue  outside  the  cnpillnry,  nnd  from  tho  tissue  to  the  bliiod.  and  thu§ 
carries  on  the  interchange  of  malcrial  between  the  blood  and  the  tisautt.  In 
certain  cireumsiance*.  nl  all  events,  white  nnd  even  red  corpuscles  may  also 
pass  thn>ugh  the  wall  lo  the  lis.sne  outside. 

The  minute  arlerics  and  veins  with  which  the  capillaries  are  coulinuous 
allow  of  a  similar  interchange  of  lualerial.  the  more  ou  the  smaller  they  are. 

The  wuIIh  of  tbe  vein*  are  thinner,  iveuker,  aud  1cm  elastic  than  thoac  of 
the  arteries,  and  |iOH«e.-4t  a  very  variahle  aiunuiit  of  niuacntar  tiwuc;  ihcy 
oollap«(.-  when  the  vetus  am  i-m|>ty.  Though  all  veiu.H  are  more  or  lent  elaMic 
uhI  lonie  veins  ar«>  ilistinrily  niuncutar,  thu  veinii  as  a  whole  cannot,  like  tint 
artericVi  be  charactcrixed  ««  eminenllv  elH.'>tic  and  conlnictile  tul>v*;  ihcy 
■re  nlJier  to  Iw  rcgunlcil  ii;<  nimplc  cfiuuni'li>  for  couvcying  lh«  hkmd  from 
th«  capillaries  to  tbe  heart,  having  just  sit  much  ehutieily  an  will  enable 
tfaem  to  aeconimoilatc  ihenixelvi-ti  to  the  ijnnnlity  of  blond  piuning  through 
Ihem,  the  same  vein  l>cing  nt  one  lime  full  and  distended  and  nl  another 
time  empty  and  shrunk,  and  only  giflol  with  any  i;reat  amount  of  muscalar 
oontractility  in  s]>eciul  cases  for  »]>eeiat  reasons.  The  united  sectional  ari» 
of  the  veins,  like  thai  of  the  arteries,  diminishes  from  iho  capillaries  to  the 
beart ;  but  the  united  sectional  area  of  the  venncavie  at  their  junclton  with 
the  right  auricle  ia  greater  than,  nearly  twice  as  great  as,  that  of  tlie  aorta 
at  its  origin.  The  total  capacity  alao  of  the  veins  is  much  greater  tlian  iJiat 
of  the  artcrim.  Tbe  veim  aluue  can  hold  the  total  masa  of  blood  which  iu 
life  is  distributed  ovtr  bolh  nrterim  and  veins.  Indeed,  nearly  the  whole 
blood  is  cnjiahle  of  being  received  by  what  is  merely  a  pirt  of^  tbe  venous 
iystem,  vix.,  tbe  vena  porUe  and  iijt  branches. 

The  Mais  Facts  op  thk  Circulation. 


$  113.  BcJbre  we  attempt  lo  study  in  detail  tbe  Rorkitig  of  iheoe  aeverm) 
pans  of  tbe  mccluinism,  it  will  bo  well,  even  nt  the  ri^k  of  »ome  Aiture  repi- 
tttion,  to  take  a  very  bri«f  rarvi^  of  tone  of  the  nlivni  pointit. 


TUX    MAIN    rACTB   or   TIIK   i^  BCULATIOX. 


165 


Al  tacb  (mU  i>f  tho  heart,  which  in  miin  ia  ivi>piUi<<I  nimut  I'i  liroee  a 
jtoatr.  ibr  cotiiniolion  or  ctbIoIc  of  lh«  veniricteii  drives  a  cerlaio  ijiiuntUy 
I'STblml.  iMxilwblj'  Binoiiniing  to  abmit  180  c.c.  (4  lo  (I  ok.),  wiib  very  ifreal 
1m  iatn  the  aurta  (awl  ihe  aaioe  <iuanlit_v  of  blond  willi  l«w  force  into  the 
pliniiaarjr  an«ry).  Tli*  diKharge  of  blond  f^om  ibe  ventrirfe  into  ihe 
HTla  »  trry  rainil.  and  tlie  time  taiteD  u|i  by  it  a,  a>)  we  sbatl  itee,  niui-h  lea* 
ihiB  ibr  iiin«  wliii-b  iiit«rTen»  between  it  and  the  next  diMrhar^  of  the  next 
hat-  8n  ifaat  tlio  Aov  from  iht<  hesrt  into  lh«  arteries  'u  iwm  dialincUy 
iMtfvkleui,  •udilcrii  r»{iii)  discburjices  alt^niating  with  relatively  b>iig  iiiler- 
nlidurinK  wbtch  lh<<  iirU-riai  receive  do  bUxul  rnim  thf  heiirt. 

AlMch  brai  of  tbv  heart  jiirt  a»  uiiii'h  bloml  fluux,  un  we  ibnll  aeo,  from 
ib(  mill  inin  ilkc  right  aiindr  an  OMuipc*  from  lliv  left  ventricle  into  Ihv 
tMta;  hat,  aa  wc  «hiU  iiUo  ree,  thi«  inHow  ia  mudi  tlower,  lukoa  a  longer 
tee,  ihan  the  dbcbarg*  (ram  th«  WDtricle. 

Wbro  the  finger  U  plncT<t  on  an  nrten-  in  the  living  body  a  sense  of  rtsist* 
iOc»  i*  felt,  and  ihi*  rv«i!>iiincc  tevm*  to  be  incrcnsed  at  intcn.'als,  conwpond- 
ilf  la  the  hMirt-bcata,  ihv  arlfr>'  nt  eueli  hcnrt-Ix-nt  being  felt  lo  rise  up  or 
aatnil  under  the  fingor,  coiutituling  what  ne  shall  HtU'Iy  hercuilWr  aa  the 
fit  In  cprtntn  tirU'ri**  this  pol»e  may  be  eG«n  by  the  eye.  When  the 
fapr  ia  nniilsrly  plaivd  oti  n  cur ree ponding  vein  rery  tittio  reaislanoe  is  felt, 
mA.muU'r  ordinary  circunlslaDOe^  no  pube  can  be  perceived  by  the  touch 
•r  bt  Ihe  ^e. 

nlwa  an  artery  is  »evered,  the  How  of  blood  from  the  proximal  cut  enil, 
itaM  Uw  heart  side,  ia  not  ciuable,  but  comes  in  jets.  correepondinK  to  the 
iMK-beala.  though  the  tl»w  duw  n<'t  cenM"  beiweeti  ihe  jela.  'llie  blond  U 
•MMJ  mth  conmderable  furoe,  ami  may  in  a  lurj|:<^  arlery  uf  a  Inr^e  animal 
m^mneA  nut  lo  the  di«lanc«  of  some  fecL  The  lurjicer  Ihe  artery  and  the 
■mr  W  tbf  heart,  the  greater  the  furn:  with  which  the  blood  ijttiics,  aiul 
ik  aon  narked  the  iiilerRiillenceof  tb«  flow.  The  flow  from  thp  dirtnl  cut 
Miihat  awav  frtiiu  the  heart,  may  be  rcry  flight,  or  may  inko  place  with 
■Milrnihle  turn  and  marked  iiiKrmiltcnce,  aeconling  to  the  amount  of 
alhlwal  coRiniu»i(-alion. 

Wbto  a  CO rrcfpi Hiding  vein  i«  aevcrod,  tho  flow  of  blood,  which  la  chiefly 
6m  tlM  ilifllal  cut  i-nd.  that  in  connection  with  the  capillarim.  is  not  jerked 
bn  raDtinuous :  the  bloiMl  coniea  out  with  companilively  little  foree,  and 
'•tU*  up"  rather  thnn  "  »puTts  oiil."  The  flow  frwii  the  proximal  cut  end, 
ikd  ta  the  heart  Mde,  may  amouut  to  nolhtni;  at  all.  or  may  t>e  Hli|;ht.  or 
t  b*  eDBfltderBliIe,  depending  on  the  preeeooe  or  abociice  of  valves  and  the 
Laf  collateral  couimunii-atiou- 
I  an  orlery  is  liuauire)!  the  veswl  awella  on  the  proximal  side,  lowanl 
Ibbovt.  and  the  thrubbiu^-  of  the  pulte  may  lie  felt  right  up  to  the  li^-M> 
m.  On  the  diMal  tide  the  veiu^l  is  empty  and  Hhrtiuk,  and  no  pulae  can 
hUt  in  it  ohImb  tlwre  be  free  cullaleral  communication. 

Wbm  a  rein  la  liffatunil  the  veMvl  iiwellii  i>n  the  diilul  i<i<[o,  away  from 
tb  heart,  but  no  puuc  is  fell ;  while  ou  Ihe  proximal  t>i<ie.  toward  the  lieort, 
liirmptv  and  collaptfl  unloM  there  h«  liro  free  collateral  riimmunicatioO. 

1 114.  When  the  interior  of  an  artery — fur  inatancc,  tho  carotid — is 
in  oomrauntcaliou  with  a  long  glaitt  tnbe  uf  not  Ina  groat  a  Imre,  bold 
Jly,  tl>o  blo«<].  immediately  u|)on  the  oommu  mention  being  elfeclvd, 

She  Mm  to  rt)»b  into  and  to  fill  the  tulie  for  a  certain  diflance,  forming 
a  mlumn  of  hltxHl  of  a  certain  heighL     The  column  risca  not  sleiwlily, 
^  by  Im|»,  each  Inp  corn* |>»n< ling  to  a  heart-ttcnt,  and  each  leap  being 
tlhoii  ita  prtsir«e»or:  antl  thta  gooi*  on,  the  incn-nso  in  the  height  of  the 
Da  at  rui-h  heart-beat  each  time  diminiahing.  until  nt  laitt  the  oulumn 


nhiDi) 


Itftl  TUli:    VASCULAR     MKCHAKISH. 

ceases  tu  rise  aud  remains  fur  a  while  at  a  mean  level,  above  and  below  which 
it  uscillatea  with  slight  excursions  at  each  heait-beat. 

To  introduce  such  a  tube  an  artery— say  the  carotid  of  a  rabbit-^is  Iftid  bare, 
ligatured  at  a  convenient  spot.  /'  Fig.  6ti,  and  further  temporarily  closed  a  little 
distance  lower  down  nearer  the  heart  by  a  small  pair  of  "  bull  dog"  forceps,  bd, 
or  by  a  ligature  which  can  be  easily  slipped.  A  longitudinal  incision  is  now  made 
in  the  artery  between  the  forceps.  M,  and  the  ligature  /'  (only  the  drop  or  two  of 
blood  which  happens  to  remain  inclosed  between  the  two  being  lost) ;  the  end  of 
the  tube,  represented  by  c  in  the  figure,  is  introduced  into  the  artery  and  secnred 
by  the  ligature  I.  The  interior  of  the  tube  is  now  in  free  communication  with  lie 
interior  of  the  artery,  but  the  latter  ia  by  means  of  the  forceps  at  present  shut  off 
from  the  heart.  On  removing  the  forceps  a  direct  communication  is  at  onceeitab- 
lished  between  the  lube  and  the  artery  below ;  in  consequence  the  blood  from  the 
heart  flows  through  [he  artery  into  the  tube. 

This  experiment  shows  that  the  blood  as  it  is  flowing  into  the  carotid  ii 
exerting  a  cuDsideritble  pres.''ure  on  the  walls  of  the  artery.     At  the  moment 
when  the  forceps  are  removed  there  is  nothing  but  the  ordinary  pressure  of 
the  atmosphere  to  counterba lance  this  pressure  within  the  artery,  and  con- 
sequently a  quantity  of  blood  is  pressed  out  into  the  tube ;  and  this  goes  on 
until  the  column  of  blood  in  the  tube  reache:^  such  a  height  that  its  weight  ii 
equal  to  the  pressure  within  the  artery,  whereupon  no  more  blood  escapes. 
The  whole  column  continues  [o  he  raised  a  little  at  each  heart-beat,  butsinks 
a.''  much  during  the  interval   between  each  two  beats,  and  thus  oscillates,  as 
we  have  said,  above  and  below  a  mean  level.     In  a  rabbit  this  column  nf 
blood  will  generally  have  the  height  of  about  !)0  cm.  (■!  feet)  ;  that  is  to  say. 
the  pressure  which  the  blood  exerts  on  the  walls  of  the  carotid  of  a  rabbit  is 
equal   to  the  pressure  exerted  by  a  column  of  rabbit's  blood  90  em,  high. 
This  is  equal  to  the  pressure  of  a  column  of  water  about  95  cm.  high,  and  Kv 
the  pressure  of  a  column  of  mercury  about  70  mm.  high. 

If  a  like  tuite  be  siniilarly  introduced  into  a  corresponding  vein — say  the 
Jugular  vein — it  will  be  found  that  the  column  of  blood,  similarly  formed  in 
the  tube,  will  be  a  very  low  one,  not  more  than  a  very  few  centimetres  high.anA 
that  while  the  level  of  the  rolunm  may  vary  a  good  deal,  owing,  aa  we  shalL 
»:c  later,  to  the  influence  of  the  respiratory  movements,  there  will  not,  as  iw- 
the  artery,  be  oscillations  corresponding  to  the  heart-beats. 

We  learn,  then,  from  this  simple  esiwriment,  that  in  the  carotid  of  tb^ 
rabbit  the  blood  while  it  flows  through  that  vessel  is  exerting  a  considerable 
mean  pressure  on  the  arterial  \v;al1^,  equivalent  to  that  of  a  column  of  mer^ 
cury  about  Til  mm.  high,  but  that  in  the  jugular  vein  the  blood  exerts  on 
the  venous  wnlls  a  very  slight  mean  pressure,  equivalent  to  that  of  a  column 
of  mercury  'i  or  4  mm.  hifrii.  We  speak  of  this  mean  pressure  exerted  by 
the  blood  on  the  wiills  of  the  bloi>dveBsels  as  blood-prensure,  and  we  say  that 
the  bliM)d- pressure  in  the  carotid  of  the  rabbit  is  very  high  (70  mm.  Hg.), 
while  thai  in  the  jugular  vein  is  very  low  (only  3  or  4  mm.  Hg.). 

It)  the  nonuiil  state  of  things  the  blood  flows  through  the  carotid  to  the 
arterial  branches  beyond,  and  through  the  jugular  vein  toward  the  heart; 
the  pressure  excrlcfl  by  the  blood  on  the  artery  or  on  the  vein  is  a  latent 
pressure  on  the  walls  of  the  artery  and  vein,  respectively.  In  the  above  ex- 
])eriment  the  pressure  measured  is  not  exactly  tbis,  but  the  pressure  exerted 
at  the  end  of  the  artery  (or  of  the  vein)  where  the  tube  is  attached.  We 
might  directly  measure  the  lateral  pressure  in  the  carotid  by  somewhat 
moaifving  the  procedure  described  above.  We  might  c<mnect  the  carotid 
with  a  tube  the  end  of  which  wa-s  not  straight,  but  made  in  the  form  of  a 
T-piece,  and  might  introiiiice  the  T-piece  in  such  a  way  that  the  blood 
should   flow  along  one   liuib  (the  vertical  limb)  of  the  T-piece  from  the 


ArroMM  NIK  iHVBRmiTUHi  UiiMit'nt 

M  •■  ■)(•*  fteM-lwDd  rmvt  l«  wdo,  ob  ■■■  tBluvBd  mta.  Ibc  afoUil  uim.  *l*ai|iwt  bv  Ite 
M.  arUkiteMcauMTMljIaaliir  lUiMr,  T»a  •rivnr  tiw  b(i>ii  t1palun<1  •!  T  •■■d  IW  |(UM 
r  kM  ■■■■•  IMta)iii>*>l  Iniii  ihrwurir  IkImmii  ilir  lltnilniTraii'l  ilx  lVi*n|aM.  uHlaHwrtil 

^  '  •-  t>.l1lBca  aiiimlail  •uluUiMi cf  laUuin  i«rUiBaw nr •  oMUiai  oT 

ma^ >(  t|i,  sr.  lira,  u»1  (■■BbtoiiT  Ivlna  ralaw)  ur  luovrrd  at  pliBUan*. 

naalalMu  ikn>  Itt  iIib  ii»tK  p.'  ncuUUd  k;  Ika  iduup  C"  IMO  Ite  lub*  l,    A  iiiliicc.  ■Hh  ■  mofr 


188 


THB    VKSOUhAH    MErHANISK. 


proximnl  to  the  dUlul  part  of  the  cAixiiid,  and  at  tbe  »in«  time  by  tb«  oUwr 
(bonzoutal)  limb  nt'  the  T-piece  iiilti  th«  luaiii   upHj^bt   part  of  itio  gla« 
lul>e.     Tlic  tubulin  ii)'  l>Iti(icl    ill  tbu  tube  would  then  \>f  a  an-asarv  t>f  lh» 
pressure  which  thi*  bhioil  aa  it  iH  llowing  along  thu  carotid  it  ^-sorting  on  ■ 
portion  of  iu  wuIIh  correvpondiiig  to  the  mouth  oftbL-  hnrizontal  limb  of  the 
T-piece.     If  we  wt'te  to  inlroduw  inio  tlie  Hurts,  Kt  the  pinco  of  origin  of  the 
carotid,  a  •imiUr  (larger)  T-pirn:,  aiid  to  connect  the  glum  lube  with  the 
borizdiilal  limb  of  the  T-pivn  by  »  piece  of  cImiSc  tubing  of  the  nmc  length 
and  borv  ok  the  carotid,  llio  column  of  blood  rinng  tip  in  the  tube  would  be     I 
the  memurc  of  the  lalenil  preesnre  exerted  by  tbe  blood  on  the  walls  of  the 
torta  at  the  origin  nf  the  carotid  artery  and  ttnnBinitted  to  the  rigid  glafv 
tube  through   n  certain    length  of  elastic  tubing.     And.  indeed,   what  i^H 
tnciieiireil  in  the  experiment  previously  described  i»  not  the  lateral  preaauJ^H 
in  ibe  cjirolid  itself  at  tbe  spot  where  the  glass  tube  in  introduced,  but  this     ' 
lateral  pret»ure  of  the  aorta  at  tbe  origin  of  the  carotid  modified  bv  tlM 
influences  exerted  by  the  length  of  the  carotid  between  its  origin  ami  Ibe 
apot  where  the  tube  is  introduced. 

§  115.  Such  an  cxixrinient  as  the  one  deei-ribed  b»A  ihe  diaadvantagea 
tliat  tbi.>  animal  is  tviitkt-ne'l  by  the  loait  of  the  bl»oiI  which  goe«  to  form  the 
column  in  the  lube,  and  ihut  the  hloiHl  in  ihi-  tulK-  noon  clotv.  and  w>  bring* 
the  exjieriment  to  an  cod.  Blood-pretciure  may  be  mure  conveniently  aiudicd 
by  connecting  the  interior  of  the  artery  (or  vein  I  with  a  mercury  gauge  or 
DUDonietcr  (Pig-  06)  the  proximal  ileiicendiiig  limb  of  which,  m,  ik  tilled 
above  the  mercury  with  fonic  iniioeuoun  fluid,  ba  in  alto  the  tube  connecting 
tli«  manonielcr  with  the  artery.  Using  such  nn  iniilrunicni,  we  should 
observe  very  much  the  Mime  fnct*  na  in  the  more  simple  experiment, 

Imniediniely  that  communicnti'in  i»  «*tnbli!«hed  between  tbe  interior  of 
the  artery  and  the  manometer,  blood  ruithi')>  from-  the  former  intu  the  Intler. 
driving  some  of  the  meri:ury  from  the  descending  limb,  m,  into  the  n^icending 
limb,  wi',  and  thus  cauuiug  the  level  of  the  mercury  in  the  aacetidiug  limb  to 
rise  rapidly.  This  ri«!  is  marked  by  jerks  corresponding  with  the  heart- 
beats. Having  reaeheil  a  certain  level,  the  nmrcury  ceases  to  rise  anr  more. 
It  doea  not.  however,  rvmiiin  ubfululely  at  redt,  but  undergoee  oscilfatious; 
it  kee|i.H  risring  and  falling.  Eiich  nse,  wbicli  U  very  slight  compared  with 
the  total  height  t<i  which  the  mercury  has  risen,  ha.H  the  i&me  rhytbin  aa  ibe 
Ryiitole  of  the  ventricle,     similarly,  each  fall  cornatjionclii  with  the  diastole. 

If  a  float,  swimming  on  the  lop  of  thi!  mercury  in  the  aiicen<Iing  limb  of 
the  manometrr,  nnil  bearing  a  brush  or  other  marker,  be  brought  to  hfnx  on 
a  travelling  surface,  some  ■'ucb  tracing  as  that  rcpreaented  in  Fig.  57  will  be 
dcscribcil.  t^vch  of  the  smaller  curvi»  (p/)i  corrc*|ionds  to  a  heart-bent, 
the  rise  corresponding  to  ihc  systole  and  the  fall  to  liie  diastole  of  the  veu- 

eocli,  BBT  te  iub«Uiutv4  Silt  llio  IwHIr  unil  ■lUi'lin]  si  r".    Tlll^  iti<1>h>1,  I>  in  uuuijr  nvimil*  ■ 
more  tadTCDlcDi  plan-    Tbe  mi-- '  lonnri.i'iwi  uiiii  ihc  Iim-Ich  mtit  1,  iiml  iw itopaDek  e  aUli  ilw 

BunoiutUir.or  U'bleb  «  lathi'  I    <.   :iiilI>,  bqiI  tifac  aiipjiart     Tbv  nwr- 

mrrlnlliiSMaiiillDB  lliDb  U'.      >.  :i,>^<    ii>>    11 >    <  nxl  ailaclinl  in  which  1*  DUad 

wUbUieiicap.  wraiSEoa  ihc  iuuMIbk  •urtaucr.    Tlic  «I>in|.oL  at  the  ciul  al  tbt  tubal  bM  «n 
enaiifanwtn  ahoua  oti »  lar^nr  waloul  the  rliilii  hand  miliar  cunier. 

n«4anMvlla|luto  not  (ho  inauciindat  Hill]  ihg  mbalboing  nmuplalal}'  Hlled  tiimit  It*  irbela 
lanfUl  Wllb  fluid  to  ibe  exoliulmi  of  all  air,  thn  mnuta  « la  ail«d  wlih  ftuld,  (llppeil  lula  Ibo  opoa 
mi  ot  Iha  thick -vallfil  Iiiitia-njIiUt  lube  i.  unUl  It  mtou  tbe  tubs  ( (wboaa  poritko  wnblu  tlia 
iDdla-nblsr  (iilw  U  ikown  hr  the  itiillnl  llnnV  and  1*  Ibaii  •viTimlj'  Dxsd  In  Itila  p«alllni  by  iIm 

Tbt  •idpi'Mkir  t  aud  f*  an  anr  npcoM.  aad  the  proauni  bniilc  talHil  or  (luld  drfTOD  Is  bjr  U» 
tritniir  until  Ihe  mcreaiy  tn  lb«  uunoncMir  t>  ralMd  in  lh«  iVi]iilmI  belglit     The  rlamp  r"  Ii  then 
Blnatd  aiut  tin  loreeia  M  nuioml  Irani  the  adefT-    T^  pmaan:  ur  Ebc  XiioeA  in  Ibe  earottd  m  U 
'  la  eonsqiMne*  Iinuijbi  lu  I've  lhn-<U(h  (  u[idii  tb*  nieiriir)  lii  llie  maoomvter, 


^ 


THK    MAIS    rACTS   Of   THE   CIBCOLATIO JT. 


189 


trid*.    Tlitf' laripir  iiodulttions  (r  r)  in  the  tracing,  irhioh  are  retipirntor; 
In  origia.  will  M  dbciiastd  h«n>«ller.    In  Fig.  oH  are  given  tiro  tnciu^pR 


1^  X, 


nt^Hlto ovm*  )•  V  arv  U>r  rolawiiTC*.    Tti*i|«M  IKnn  r  (n  r  vmbmi'ca  n  rcrfdntiay  and*- 
M«  1Wln<ilai9>ukiiqnvB»dcc.B<>4U>B  lrn«uliulll«TWIiialiittucUKiwrn>|iM(illr  M«l 

nha  fromltbe  rarotid  of  a  rabbit ;  in  ili«  lower  curve  the  reci>nliiig  mirfiire 
iiinndlia^  inon;  rapidlv  lliuii  iii  tlie  umier  rurve:  utbemi«e  iliv  curves  iire 
ittaMd  repeat  the  Jteneral  f«tur«t  of  Ui«  curve  from  tlie  dog. 

no.  M. 


'*.J\y\^/Kj\J\^ 


liiflnnrKBmiac  Cnrai  meat  rai  C^ion*  or  B>MfT.  nix  lau  "*■"* 
in  uo  HUM  Uittom  Bbcdsm. 

fl—yltw  ^  rxfirriHtrnt.  In  a  CHrotiil.  or  other  bloodvMM],  |iroparti]  at  ex* 
(UmJ,  ■  Rdnall  RIM*  lube,  of  »utUbU-  liori'.  called  a  amata  a  introduced  by  Ibe 
Brihod  tleaoitied  atiove.  Aiid  ia  suliw<]UFDtly  ouniiecled,  by  eacaos  of  a  aliorl 
rwoaf  India  rubber  tubing  { Figi.  M  >),  aikI  s  Iciulfn  or  other  lube  <  which  U  al 
«n^lrlllil«  and  yet  ool  exiciuihic.  willi  lhi>  i)nii-en<lins  Itnih.  m.  of  ihc  nuuin- 
«M<crot  mtrcury  cauiir.  The  cnnulit,  (ubr.  anil  <ltiici.-ii<liii);  limb  of  the  nianu* 
twan  all  filled  with  toine  fluid,  which  tenil*  lu  {irrtent  clotting  of  the  hlood, 
innc  chnaen  bpinK  generally  a  atroiig  tolutloii  («[».  ^r,  |i>S3)  of  aoiliiim  bicar- 
•,  Uii  other  Hums  oiaj  ha  cbo««n.  In  order  to  avoid  Iom  of  blooil.  a  quao- 
'  flulil  i*  iiijrtMd  into  ibe  flexible  tube  auffieient  lo  nuBO  tbe  morcory  in  the 
(  limb  of  the  manometer  to  a  1»vf1  a  rery  little  Iwlow  irhni  niny  be 
■d  gn«Mtd  at  iw  the  irnibabic  meiiii  [ircMure.     When  llie  (oref|M  M  are 

h\,  the  prMHire  of  Ibe  bl'iod  in  tbe  carotid  in  irannniiiied   Ihrougb   Ihr 

luiUr  tnW  u>  the  muioBieter,  the  lrv«l  of  the  mercury  iii  the  lucciKliiie  limb 
«f  ehkh  falU  a  little,  oraioks  a  lillle  al  finil,  or  uiay  du  iivilher,  aecorJing  lu 
lb  MkfTvM  «iib  nhieh  itic  prubable  riivaii  prrwaiire  hnn  been  guooied.  anil  on- 
llnai  In  eihiblt  tbe  chiraetetinllc  oM-ilUll'init  until  thu  experiment  U  brought  to 


u  ml  by  iba  Miioil  ilotiinx  or  otbnririM;. 
ITneli^p  of  the  im<iv«<ii 


_      .    ^  iiv«<incnli  of  ibe  oitumn  of  mercury  in  tbe  manometer  may 

wukra  riihmm  a  mnohed  surface  of  a  revolving  cylinder  (Fig.  )l>.  or  by  m«anii 
«f  abnuh  and  lok  on  a  oiniinuoui  roll  of  tiaper,  aa  in  the  more  C"ai|ilcx  kvaiO' 
■id-ig.W)- 


IWl 


THK    VASCL'LAK    MKC'IIAMSM. 


S 116.  B^  iht  help  at  Uio  taanAtuot«r  a])pl!«d  to  various  art«r»eei  ntid  vt 
vn  iMrn  Uic  folluwiuic  tiu-i^: 

1.  Till'  iiii-uii  1>lii<iil-['ri'!«<iinr  la  liigli  iu  ull  tlie  arit-rioi,  tiui  i*  greater  in 
llic  lurgiT  nrtcrit^  iiritrcr  llii?  h^-nrl  tlinri  in  lli«  miiEillur  urieries  I'lirthi-r  tfum 
the  hmirt:  il  iliuiiiii.-'liot,  ill  fnci,  ulong  the  urterinl  Lnicl  frutn  ihe  liuirt 
l»vriiKl  (Iu-  (-ii|>illnrii-9'. 

'J.  Till-  nicnn  Wniid  jircMuru  id  luw  in  lln-  *'dii»  but,  io  grrali-r  in  tin' 
emalkr  leina  near<-r  lh(>  iiipilliiric*  tliun  in  llic  Inrgvr  vi-i:i»  imrtr  ttir  UiMtt, 
diniioishing.  in  fiicL,  Oom  the  i-apillariof  lowiirvl  (he  Iiviiri.  1»  tliu  largo 
veins  near  tlic  heart  it  may  bo  ifj-ilix-r.  thai  i*  to  rny.  the  pri'S^ure  ol'  hlmti 
ID  the  vein  bcarini^  on  the  proximal  dctudiiJitig  limb  of  the  ninnomclcr  ma]r 
be  leas  llinn  the  pr^MUrc  of  tb<<  alnio^phtrc  uii  ihi'  sHCfiiidinc  iliital  limb,  eo 
that  when  coiuniiinication  in  nindo  Wwccd  ihe  inieriur  of  tna  vein  and  the 
wunomeler,  the  nterivtiry  lunkt  in  lh«  distal  and  rises  in  tbe  proaiiual  limb, 
being  nuk.'ked  tip  Mwanl  the  vein. 

na.U. 


Si^l 


■--a  ■ 


tjCDWM't  XvaooRirii  roa  kaamnjiu  tin  a  CViNTtvunis  Kou.  up  I'atu. 

Thti  tnanomctor  cannot  well  bv  apniied  ui  the  capillarioa,  but  wo  maT 
ipcamirc  tbe  bloml-premtirv  in  the  cnpilhine«  in  an  imlirbct  war.  It  is  well 
knnn-n  that  when  any  portion  of  the  skin  in  prerned  upon,  it  becoin«  pal« 
and  bloodless ;  tiiio  is  due  to  the  preasiire  driving  the  bliHjd  out  of  the  ca]>il- 
lariea  and  miautc  veawls  and  prevenliu);  niiy  frtvh  blimd  t^ntcrtng  into  lb«D). 
By  earvrtilly  inveetiicittiog  the  iimouni  of  prtmnre  mxiitfiiry  to  prevent  tb« 
bli^xl  eiili^riiiK  ll>^  eapillarii«  and  miniii<<  nrt^riux  of  |h<<  nt-b  of  tbe  frog'a 
foot,  or  of  (he  nkin  bi>uvulh  the  oail  itrelMwhcrv  in  nmn.  the  iuternnl  pr<«- 
Hire  which  thtt  hbHHl  id  exerciiiiug  on  tht?  walla  of  lh«  capillariea  and  minute 


TIIE    MAIS    rACTS   OK   TIIK   C1KC17LATI0K, 


lOI 


■llfja  awl  v«itu  mav  be  Rpproxiinaiclr  <l«termiaoiJ.  In  the  froR's  web 
bMD  fuuiid  to  lie  e(|iiul  to  about  7  or  11  mm.  of  merciiry.  lo  tlie 
tb*  capillarT  liltKxI-gtre&tui^  n  naturally  higher  lliaii  thi*  aiid  maj 
!•(  ilowa  at  fruin  'JO  to  ^U  rtini.  It  is.  tlieivforv,  c»»»i(l«mble,  beiiiK 
ptawr  llian  thm  iii  lliv  vvmn  lUonKh   \tf»  itian  lliai  iu  ihe  Brl«ri«a^ 

JL  Tliprp  bi  llius  K  oniiiiitiifl  di-cliuL'  of  bliiiMi-pn-BMire  Trnm  tlie  nxil  of 
tk  aurla.  llinxigli  thv  arli^ncii.  t'lijiilliirirs,  hdiI  vi-iti.-t  Iu  lliv  tigltX  aiirirl«. 
Vrfiod,  bi>«rvrr,  iiii  I'xiiniiniiiinii  tliiil  tbe  mint  nmrkt^l  Inll  of  [iritc^nre 
lU*  |>la<v  bi-t<iti.-rti  tin-  kiiihII  ntte rim  un  lUu  utiv  xiilir  of  the  nipilliiruv  am) 
Ibtwiall  t*riiu  OD  iIm>  ntlier,  iIm'  i-iirvo  iif  {imviin-  IkJiij;  itomcwliril  of  tiie 
tm  given  ill  Pig.  t>0,  wlik'li  »  >iiii{>ly  iiK^nilftl  li>  tlmw  thw  fact  gnii>liinilly 
mi  bat  nM  bMO  ranMriirtei)  by  exact  ni«ii»iin-miiiU>. 

Fill.  cu. 


I'MOIUI*  or  niJUnlVPBBMtTlta. 

/*.  tcH|iliemln4tealmliiiili(Knnte*.<w|il1lrulei.aD4  vdai);  V.Miu. 

i  In  tW  art«Ti»  thk   meuo    pmaure  b  niarked  by  oadllations  cam- 
In  tbe  tienrt  beats,  each  wcillatiou  coosMtiiiii;  of  a  riwe  (iDcrease  of 
in  abote  tlie  nictm)  eorratpondiiiK  to  Ibe  systole  of  tlie  veiitriol«. 
by  a  Call  (dfcreaaeof  prctwire  below  tlie  moan)  eorRS{ionding  tu 

idiMtoM  of  the  vvutricle. 
Vum  owdllatioDH.  nhkb  yn  may  .-jirak  nf  iia  the  pulse,  an-  lurgcvt  and 
■M CM^iinwua  ill  the  l«rg«  arteric*  iK-iir  lliu  lioiirt.  dimiiiiiih  fnni  (ho  heart 
Wiwd  ibt  capillarioi,  niid  iire,  iiiiik-r  uriliniiry  (lircuiimtuiii-'uii,  vrholty  hIumiI 
fha  iba  Ttina  alnng  tbcir  nbolc  exirut  frvim  the  mpillnrim  lo  tlii^  hcnrt, 

ObriDualy  a  ^rvat  obangv  Iaki9  pliin-  in  tlint  piirliim  nf  thr  i-irviiliitioti 
vUdloamprion  the  mpillariiv,  the  iiiiuiiU^  arli-rii-n  li-iidin)i;  to  am)  ihc  minuto 
*tJH  laadmg  away  from  llio  capilliirii.^,  luid  nhich  w-  miiy  apvak  of  n»  the 
'pwiplmsl  rf^on.*'  It  is  hen-  that  n  great  drop  of  pmviiro  tnkM  plaec ;  it 
iikftalwi  that  thr  p^ilse  diMpmare. 

|UT.  If  lite  neb  of  n  lixiga  fixit  be  ciaminni  with  a  tnicnwcope.  the 
bliul,  aa  jiidgt*!  of  hy  the  nwvemvnts  of  the  corpuBclcs,  is  sevii  to  be  pnssin),' 
in  a  DuotuiuiMis  rtn-iim  from  the  small  arteries  through  the  ea[^llaries  to  the 
im».  The  vidoeity  is  giealcr  in  tlie  arteries  iIibii  in  the  vv'im,  and  greater 
ii  belli  llian  in  tlie  capinnries.  In  the  nrleries  fuiut  puliuitiunB.  ^ynehronoDS 
ailk  iba  heart's  bent,  nre  freipiently  visible  ;  b4it  these  dirapjtenr  in  tliv 
■nillariea,  in  whtvh  Ihe  llow  is  even,  that  it,  not  brokeo  by  piilsalioRs.  and 
t^  iTeDDceB  of  flow  is  continued  ou  alon;t  the  veins  as  far  as  we  enn  irnco 
iImo.  Nut  infre<(ueiitlT  vnriiilii>n-i  in  velocity  and  io  the  distribution  of 
lb*h|nud,  due  tocauM*  whieh  will  l>e  hereafter  ilit«uai«d.  are  witiwBsed  from 
liawif)  liine. 


102 


The  chRraclcr  of  fho  tlow  ihmugh  the  smaller  cspillnrira  is  wry  Tmriabl«. 
8oiiietiin««  the  curpiiecW  nre  seen  prntsint;  through  the  i-hnnii«l  in  siDf^le  6k 
with  great  ref^iilariiy;  nl  riiher  liiues  ttiey  inar  be  lew  luid  far  betn'e«ti. 
twnie  uf  the  capilliiric^,  as  we  li&ve  said  in  ^  107,  are  wide  eai>u]{b  to  permil 
two  or  more  carpiiBcle«  abreaat.  lu  k1)  caaee  llie  blnod  aa  it  paasos  ihrou;^ 
ttie  cspillary  Airetcbea  and  ex|)iiii<!s  the  walla.  Sunieiimcv  a  corpuscle  uuiy 
remain  aiaiiuiiary  at  Ihe  eiiirHiice  itilo  a  i-a|iillartr,  ihe  chauoel  itself  botng 
for  some  little  distance  enlirt-ly  live  frcnn  Gur|iuioles.  Saraetime*  many 
corputteJes  will  appear  to  rvmaiu  uratiuuary  in  one  or  mon  vapillaric*  for  ■ 
brief  period  aud  then  in  niiive  oa  uKaiii.  Any  one  of  ihettc  coitililioiu 
readily  \vtMti  inlo  iinulher;  and,  cii|>i.'cially  with  a  aamewhat  feeble  cireula- 
tiim,  itialniii'CAof  all  of  them  may  )ie«eeR  in  the  name  lli^ld  of  tbe  niicrniH'opc. 
It  in  only  «lii-ii  tbe  vt^itN.'li'  of  the  w<:b  arc  uHumially  full  i>f  hUiod  that  all 
the  cniiillnriw  r-an  he  «cn  vaiinlly  filled  with  corpuscle:!.  Tbo  long,  oval  rod 
ourpu»cle  inovra  wJlli  iv  long  axis  parallel  to  ihc  stream,  oceaeionnlly 
mUttin/^Dii  iu  lung  axis,  niid  ■i>inrl!me«,  in  the  ]nr;gcr  channels,  on  ir^  short 
axis.  The  flcxibilily  and  rlnxtiiiiy  of  a  Rorpusclo  are  well  seen  when  it  » 
being  driven  into  a  capillary  narrower  thtin  itself,  or  wben  it  bccomva  tetn- 
pornrily  lodged  al  the  angle  between  two  diverging  channels. 

Thno  ana  ntber  phenomena,  on  which  we  »tiall  dwell  Inter  on,  may  lie 
readily  seen  in  the  web  of  the  fn>g's  foot  or  in  ihe  stretched -out  tongue  or  in 
the  niewntery  of  the  frog;  sad  e»entially  similar  phenomena  may  be 
observed  in  the  mesentery  or  other  transparent  tissue  of  »  msmmal.  All 
over  the  body,  wherever  eapillaries  are  present,  the  corpuscles  and  tbe 
plauna  are  being  driven  in  a  eonlinuous  and  llinugh  somewhat  irregular  yet 
on  the  whide  Meady  flow  ihron^h  channels  so  minute  that  tbe  poasage  U 
maniftBtly  attended  with  cousiderable  dilUculliea. 

It  is  obviouH  that  the  peculiar  ebaracien  of  Ihe  flnw  through  Ihe  minute 
arl^irie*,  capillnriia,  and  veinn  affonL*  an  explanation  of  the  ffieat  change 
taking  place  in  thi-  |icri|iheni]  rt^ginn  between  lh«  arterial  flow  and  the 
venous  fluw.  The  muted  Mretinnal  area  of  tin*  capillaritv  tt,  n.*  we  have  seen, 
BOiDO  faundrvils  of  times  grvnier  than  the  sectinnul  tin-a  of  the  aorta;  but 
this  nnic<^il  wclionnl  area  is  nindc  tip  of  thousandH  of  minute  piuwigca, 
varying  in  mmi  fnim  ■>  U>  '.'(I  u.  some  ot  them,  tlien-fore.  being  in  an  undis- 
leaded  condition,  smaller  than  the  diameter  of  a  red  c(jr[Hiscle,  Kven  were 
tiw  blood  a  simple  liquid  free  from  all  eorpiiccles.  ihcw  extremely  miniile 
piWUflfii  would  occn«i(iu  an  enormous  amount  of  friction,  anil  thus  present  a 
oontaderable  o!>stacle  or  rvaiatttuee  to  the  How  of  blood  through  ibom.  StjII 
greater  must  be  tbe  friction  and  reftisinuce  oceasiontu)  by  tbe  ncliial  blood 
with  its  Tvd  and  white  corpuscles.  The  blood  in  fact  meets  with  great  difG- 
eultiee  in  its  pasan^'e  through  ihe  peripheral  region,  and  somelinies,  aa  we 
ahall  aee,  the  Iriciiou  aii<l  resistance  are  so  great  in  the  peripheral  reoaela  of 
ihia  or  that  area  ttial  no  bJmid  pa^tiea  through  them  at  all,  and  an  amat  of 
tlie  Jitiw  lakes  place  iu  the  nrea. 

Tbe  nwiHtauce  t<>  the  (l><w  of  bloud  thus  caused  by  the  friction  f^uerated 
in  Ml  many  minute  pawagen  i»  one  of  the  moet  important  ph_\-sioal  fiuita  in  tbe 
drculation.  In  the  large  art«rie«  the  friction  is  small ;  it  increases  gradually 
M  tbcy  dividi',  but  nn-rivM  iu  chief  and  most  imporluut  addition  in  the 
minute  art<iriv»  ttn<l  mpillnriv*,  it  ix  relatively  greati-r  in  the  minute  arteries 
than  in  the  ciipilliirii-*  nn  accoiinl  of  tin-  IIdw  being  more  rapiil  iu  the  fnrmer, 
for  friciinn  diniinii>h<«  riipidty  with  a  iliminiilion  iu  the  rale  of  tlow.  We 
may  speak  "f  it  as  tbe  "  i>eri[iheral  Irietion,"  and  the  roixtancu  which  it 
oflersus  Ihe  "|>eripheral  resiniance."  It  need  perhaps  hanlly  W  mid  that 
this  pheripheral  resistance  not  only  op|Hisc»  the  flow  of  blood  Uirough  the 
c*|^Iartue  and  minute  arteries  thonisvlves  where  it  is  generated,  but,  working 


THE  Mais  wxcra  of  tok  cibcdj-atjos. 


193 


■ckvard  Rlvng  the  whole  irurial  iyittftin,  has  to  b«  uveroome  by  th«  h«irt 
1  «acli  ■jraloJv  of  Ui«  ventricle. 

JlgdraHlie  Priaeiplr*  of  fh^  CirttutntloH. 

8.  In  ifav  drrulntinii,  th«n.  ihc  fotlowing*  three  Gictx  of  fuDdnnwital 
taiiM  MTt  net  wiib  : 

Ttw  >jr*iuJe  n(  the  vcDlricIc,  driving  at  intervals  a  certnin  tjuaDtilr  of 
Uood.  with  K  eortaiii  foixw,  into  the  tiorUi. 
3.  Tb»|Mripbnal  rtsistance  just  detcribed. 

S.  A   km;  MnKch  of  elastic  tubing  (the  arleriee>,  reaching  from  the 

to  tlu!  region  of  peripheral  resisuiDC«. 

<m  tfanc  fnds  wo  titaj  explain  the  main  phenomena  of  the  circulatiou, 

Aith  ««  have  previously  sketched,  on  purely  physical  piiadpl«s  without 

U<r  arptal   to  the  »{)ecial   pn>perti«a  of  liviuK  tiasuis,  beyood  the  provisioD 

Uai  tKr  veoirirle  remains  c»]>aDle  of  (pMvd  rhythmical  con  tractions,  that  lh« 

■fkrial  walls  retain  tlieir  elasticity,  and  that  the  friciiou  betwoeu  the  blood 

u4  Ih*  lininj;  of  the  peripheral  vessels  remains  tlie  same ;  nc  niuy  thus 

nyUo  the  htgb  prasurc  and  pulsatile  flow  iu  the  arteries,  the  steatly  streuin 

luMffb  tbe  capillarM«,  the  low  presanre  and  the  unilnrm  pulscltMS  lloir  in 

(bniBa.  aod  nnally  the  continued  flow  of  the  blood  tVom  the  aorta  to  lh< 

moiIm  air  the  vean  cavir. 

AH  ibe  atHive  phenonH-na  in  fart  are  the  simple  nviiItM  nf  iin  iiitrrnillteot 
firw(lilte  that  uf  the  sys't'Lilc  of  the  vrjilricle)  working  in  a  cl<.iM-d  circuit 
*f  Ismching  tulMs,  wi  iirningul  that  while  the  iudiviHiiiil  tubes  lirel 
^iamili  in  calibre  (fmni  ihr  heart  to  the  cnpillnrie*)  anil  then  incrvusc 
Am  (h«  capillarifv  td  the  hrurt).  the  area  of  the  bed  lint  increoHw  and 
Wi dimtnishts.  tlie  tubes  to;^iher  thus  forminf;  two  conee  placed  base  to 
it  the  capillaries,  wilh  their  apic.'cs  converging  to  the  heart,  aud  pro- 
at  their  conjointed  bases  a  conspicuous  peripheral  reaistaiifv,  tlio 
cm  one  side,  the  arterial,  bdtig  eminently  eluittic,  and  on  the  other,  lh« 
,  affiwdioff  a  (tee  aud  easy  panage  for  the  blood.  It  is  the  peripheral 
aae  ({or  tbe  reaistaoee  oftVred  by  the  friction  in  the  larner  vmmIs  may, 
•hso  nniDared  with  this,  be  practically  ueglecl«d),  reacting  through  tlie 
•Wc  walls  of  the  arteriea  upun  tlie  intermtlteut  force  of  the  hiuirt,  which 
pirn  the  drculatiou  of  the  blood  its  t)cculiar  fcaturu. 

iU9.  Virtumtlatuet  ilftirmmiuQ  Ihr.  charaeirr  of  lAe  fiow.  When  fluid 
k  dfivfO  t>r  an  iDiermittent  force,  as  by  n  piinip,  through  a  [lerrnctly  rigid 
M^  soeh  aa  n  glnas  one  for  a  fy*t«m  of  xuch  lulim),  there  nu-apvs  at  eavb 
mb  of  the  pump  from  the  di*tal  end  of  tbi.'  tube  (nr  .ivi>lem  of  1u1m»)  just 
■  ■aeh  fluid  AH  cutirt  it  at  the  proxiiiinl  end.  What  bnpiiciM  is  very  like 
ah*  woald  hapjien  if,  wilh  a  wide  glsn  tube  completely  Bllixl  wilh  biliinrd- 
Uls  lying  in  a  row.  an  additional  bail  were  puabcd  in  nt  one  end  ;  each 
hsD  would  )ir  p(i»li<Hl  on  in  turn  a  tl»fp  further  and  the  last  ball  at  the 
hither  end  «i>uhl  tumble  ont.  The  eacape,  morvovor,  takes  place  at  the 
—«»  lime  «a  the  entrance. 

Ihi*  rcanlt  remains  the  §anie  when  any  resistance  to  tbe  flow  is  introduoed 
Mo  the  tube,  as  for  instance  when  the  end  of  the  tiit)e  is  n.irrowed-     ThA 
:  of  the  pump  remaining  >he  same,  the  introduction  of  the  resistauoe 
•btedly  Icawns  tlie  ijiiantity  of  fluid  issuing  al  the  distal  end  at  each 
s,  Imt  it  at  the  same  time  let*«iis  tbe  quantity  entering  at  tbe  proximal 
lh«  iolluw  and  outflow  remain  cijual  to  each  other,  and  slill  occur  at 
saw  time. 
la  an  alattic  tube,  such  as  an  India-ratiher  one  (or  in  a  system  of  suoh 
nW).  whose  aectional  area  is  suflirientiv  great  to  oJler  but  little  reuatanoe 

13 " 


TIIS    VA801II.AR    UBcnAXltsW. 


Ik  iIh-  |>rogr«M  of  ihe  iluul,  the  flour  ciiused  br  an  iDtermiUeal  force  b  rIw 
inli'rnuttcut.  The  outfluw  beJOK  uearly  as  t-oAv  as  the  ioSow,  tlie  elulidlf 
of  till-  \>flllii  (>r  thf  tuW  i>  H-anvlv  iit  «)l  talletl  inio  (lUy.     The  Lube  behant 

SnctH'til))'  Itk).'  H  rigi<l  iuIk'.  \Vbi;ii,  h»w«ver,  auliickiit  rmMaDce  u  intn- 
ucc<l  into  liny  iitirl  of  tke  voiinto,  the  lltiiil  being  unnbte  to  pnat  by  ibt 
mwlancv  m  ntfHmr  ni>  it  eautn  tJw  tube  fmn)  i}i«  |iunii>,  lenilfl  to  acminiiliie 
on  thi>  nroxiniiil  inilo  of  iIhi  nxiialaiu'iv  Thi*  it  u  Able  to  ilu  by  ex[i<in(lia( 
tbeeinstic  wuli*  of  tbitliibv.  Atuivh  Mrukoof  the  fHimp  n  vertnin  ()iuuil)l}' 
of  fluid  ctitcn'  tli«  tube  at  l)ie  pruxiuwl  cud.  Of  iImh  only  n  fV«<-lioa  cu 
pBA  tJirough  t)i«  reMctiincc  duriag  the  »troli«.  At  ttic  iw>m«ni  whw  thi 
Mrokc  CM8W,  th«  rait  »til)  nrmainM  on  (he  |ir(>xinuii  aide  til'  the  nvislUM, 
tlK  elastic  tube  having  «xpaud«d  to  reoeivi;  it.  During  tb«  inivrAiil  bvlwwa 
tiiia  and  the  next  Rtroke,  um  dietendnl  elanlic  lulxi,  Hnviag  to  rrtum  in  !tt 
natural  tuidulanded  condition,  prcnn  on  lhi»  extra  ({uanttty  of  Huid  whidi 
il  coiitaina  and  tends  to  driro  it  past  tlie  mistnncw. 

Thiia.  in  lh«  rigid  lube  (and  in  the  oln^tic  tube  withotil  the  reoitaocf) 
tliere  ie«iic&.  f'runi  the  diolal  end  of  iho  tube  at  each  stroke,  just  as  nnifa 
fluid  as  eniere  it  at  the  proximal  end,  while  between  the  strokes  then  !■ 
perftet  (juiet.     In  tha  elaslic  lube  with  reustiuice,  on  the  ountrari-.  the  qiuu- 
titr  wHioh  jMxto  the  renalaace  is  only  a  I'rauiiou  of  thai  which  euienilit 
tiilte  fnun  the  pump  at  anyone  stroke,  the  remainder  or  a  portion  of  tlw 
reinnindcr  <'(mtiuiii»K  l*>  [>sm  durinjt  thv  iuler^'al  between  the  strokes.    U 
Uut  fonuer  ruav.  Llie  tube  u  uo  fuller  at  the  end  of  the  stroke  than  at  tW 
b^innin)! ;  in  the  latter  caae  there  in  an  necuniulation  of  fluid  between  ibe 
pomp  and  the  nsiHtuum,  and  a  eorreiipmditi};  distension  nf  thai  part  of  ibe 
tube  at  the  rtiBC  of  earh  »lriikt! — an  nci'timiilatiun  and  dislciiBtitu,  liowever< 
which  20  on  diniiniohiiie  during  ihir  iiitcrvul  hrtwevn  that  Mtriike  and  tb^ 
next.     The  nniminl  nf  fluid  ihiiii  remaiuin);  ufter  the  Htruke  will  depend  uO 
tke  amount  of  n-»i»Ca»pe  in  rclnliim  In  ili<;  force  of  the  sLroko  mm  on  ll>* 
tliateiuiibility  of  thit  luhr ;  and  cbr  amount  which  jiaflMM  tbo  mistance  Wnr^ 
the  next  rtroke  will  ilcpviiit  on  the  drgriv  of  elnstJc  rottction  of  which  tl»* 
tube  is  capable.     Thus,  if  l)i«  miRtnnco  be  very  iiinsiderabic  in  relation  t^ 
the  force  of  ihu  rtrokc.  and  the  tul>e  vtrry  di«tcn«iblc,  o«ly  a  »miiil  n>nioav' 
die  Saul  will  [lOW  the  rc«i«(iu)ce.  the  gn-nier  [Hirt  remaining  lodge*!  betwve** 
the  pumn  and  the  rwaistanoe.     If  the  elastic  roactioii  be  grent,  a  larife  po^' 
tiun  of  Ihis  will  be  pmed  on  through  the  mistanoe  before  the  next  stroke 
conies.     In  uther  wunU.  the  greater  tbe  resistance  (in  relation  to  the  for^ 
of  the  stroke^,  and  the  more  the  elastic  force  ia  brought  into  play,  the  lei^ 
iulermittent,  the  more  nearly  continuous,  will  be  tbe  Bow  on  Ihe  far  side<» 
tke  resistance. 

If  Ihe  first  stroke  be  succee<led  by  a  second  stroke  before  its  tpiautity  of 
fluid  has  all  passed  by  the  resistance,  there  will  be  an  ailditioual  accumula' 
tion  of  fluid  uD  the  near  side  of  the  resistance,  an  adililJonat  dbteurion  of 
tbe  tube,  an  ad<Utional  strain  on  its  elastic  powers,  and,  in  con*er]iieiice,  tbtr 
flow  hetneen  this  second  stroke  and  llie  tfaini  will  be  even  niont  miirki-d  thUL 
that  b«iweeu  tbe  first  and  second,  though  all  three  strnkcM  rn-ri'  of  ilw  sani* 
fom,  the  addition  being  due  to  the  extra  aiuouiit  of  diuttic  (•<nx  called  int» 
plav.    In  fact,  it  u>  PviiH-nt  ihut,  if  then.-  1h'  a  sufficient  store  iif  eliu^ic  power 
to  lall  back  u|>uu.  by  i^oniinually  repealing  the  strokea  a  state  of  thin|f<  will 
be  at  la*t  arnvwl  ut  in  which  ifie  plastic  force,  callc*)  into  play  by  the  coa- 
dnually  tncn-iuiiug  dinicnxiou  oi'  ilxi  tube  on  tlie  near  side  m  trie  reeiuanoe* 
will  befuRicii'iit  l<>  drive  thnnigh  llie  raualauoe,  between  each  two  siroksa* 
jtlst  a»  much  fluid  iw  cnlcm  the  nirar  end  of  the  syalem  al  eneh  stroke.    Ik* 
olber  words,  the  elastic  renclioii  of  ilu-  wnlU  of  tlie  tulx;  will  ha?e  OODVMtcA 
the  iut«riQitt«iit  uuo  a  ooutinuMia  How.    Tbe  flow  on  the  br  aide  c 


THE   MAIS    FACTS  OF  THB  CIBCUI-ATIOS. 

IM  [«  in  lh!s  <-«M  not  tlie  •/!>«¥<  reeull  of  the  strokes  of  i)iv  ]iuii]|>.  All 
v»  nf  ihc  pump  ie  epenl.  6ret  iu  getting  up,  and  afterward  iii  keopiiij; 
i^  tlio  ilieleo^ion  of  the  Uibe  on  the  near  eide  of  tl>G  resistance;  (ho  immft- 
Kte  caiiac  of  the  coDtiououa  How  lies  in  the  disteiiMon  of  the  tul)c  nhiob 
his  it  to  eoipt}'  itself  into  the  far  side  i>f  the  resistonee  at  suob  a  rui«  that 
dtschar][«8  tlimuifh  the  rrais(aii<-e  dnriii^  a  stroke  and  in  th<!  viiccecding 
l«ri  kI  Just  la  luucti  as  it  recirivui  frum  (he  pump  liy  thi?  ilrokc  itiitlf. 
Hiis  id  exactly  uhat  Inkm  plm-^  in  the  viiscuiur  avfllein.  The  friction  iu 
p  minuie  artc-ritv  and  ciipillntie*  pr<4eiil)i  a  coiini<MrruliI(!  rexuilaiiw  to  the 
f/n  of  hloiHl  through  ijieni  iiito  thi*  Kiunll  veins.  Iu  coni«-r|uence  of  tliis 
UatMice  the  ibroe  of  thr  ht-iirt')!  heiit  m  «pMit  in  niiiintainiiig  the  whoU  of 
te  arla^rial  pyoiem  in  a  ilntv  of  grent  di>Et'n>i>in  ;  ihr  nrlerinl  wiillii  are  put 
t^Mif  iiu  tli«  Htretch  br  tbe  preHura  of  ihi.^  hliiuil  thrust  into  (1r-iii  bv  the 
t|ar«trd  olroko  of  the  heart ;  this  U  (lie  prtroiiro  wliich  wo  Bpuko  of  above 
I  bluHl-pnwiiire.  The  ureatly  dii^leudtd  iirtrriul  qretcm  in.  br  the  elastic 
MolKMi  of  lis  elastic  walls,  eontiuually  lending  lo  rmptv  itself  by  uvertlow- 
p%  ikmuf^h  the  capillnrtes  into  the  venous  svMt'ni ;  and  it  ovcrtlows  »t  such 
tnUi  ihni  juBl  ne  much  titoixl  i>aai«s  from  the  nrteries  to  the  veii)»  durlug 
Mi  ajstole  and  iia  sucL-eediug  diastole  as  enters  the  aorta  at  each  sfelole. 

« 
ru.<t. 


■:l/fi 


Aatnu*t  Sirnm. 
— „il.  ball  clMI'*  inlxtn  n(«tMiil  ih*  trtmal  •jitem,  bnuicblni*!  X  nii'l  V.  and  (ndlns 
*kn^ninr  |i<Tl|>lwnl  mMtaim.  lacli>llnii(hocai>lllkrl«^(rblchBi«iinlutol  br  olUav  IoomIt 
'*'^IMU  jtvm  bI  tpiinc*  i*»  |«ru  iiliaoii  u  dilated  tn  llie  ngmr.  Tlw  ea|4UiiTlgi  air  galliond 
*'MUi  tmim  (j-tiiB.  ibiulol.  H'hKb  icnnlnaWaatU.  WaMr  I*  drlrtn  into  the  anntal  vj»\ma 
I'T**  "" '■  er  ail  i-laMt*  fe*|t<yrii>«D  <»  anr  o(hcT  ream  drpimpi,  C1aliiiaB»  ptu«<J  on  Ibn  iindl' 
"'''Mar,  (•,  p".  W'li(-n  llivw  Dlani[atanll«lili-iird,  Uiruiljr  accaa  Ibaltir  aatiir  it'Oa  ttiaanarlat 
'"'•••■aBMitalalliR'iialinii;4IMrd  parla  niird  wini  iirODg*,  whif h  e An  a  raiuldanbt*  nitat' 
^*<killO*ar  I<ildUm<ti|ibtbaln.  Wtttn  Ib(  plDin|danDlilaaK<!  HtcHiild  pwaca.  lalUi  OMtcfa 
"■MtNutra^  Hiimifh  ilio  iindllaHd  litbM>  Tliiu.  Iiy  ll|[hltaIuK  or  louMitii(  lh«  elamt*  tba 
'"Mmt'  naliiaiun  mtf  In  Intrt— <l  or  dIjnIoMml  M  jjwjnw. 

'**.<•  llMtfiariai -hie.  aiKiai  V.  oa  iho  nnon*  ilitc,  iMiwanetcncan  be  altaobed.  Aiatnd* 
^■Mtt  I  «iid  f  I,  bj  nmiiii  or  riaini*.  Itw  nuir  i>r  dald  ttt^  an  ait^vy  add  team  a  vidn,  ondar 
"^tcMIBwk  awr  l«  «t«tnO.   M  fa.  fa.  and  t^r.  t|ih]iiiia«n|ibi  may  be  appBtd. 

IIMI,  ladeeil,  the  tniportant  Incls  of  tbe  circuliitioii  which  we  have  not  iu> 
T*i  i>udtti)  may  In  roughly  bm  Hicccwfully  iroitnled  on  an  nrlificial  model. 


Fig.  61,  ill  whioli  an  elastic  syringe  reprefieoCs  ibe  heart,  a'loii(f  pi«v 
dasiic  liidia-rubWr  tubing  the  arteries,  anoilier  pie<.-e  uf  Iiibin;^  ttie  veins, 
and  a  number  of  Hiuallcr  (.-ounecting  pieces  the  minute  arteries  and  onpil- 
lari«e.  If  these  connecting  {liecea  be  uutde  at  Ant  aomcwlint  wide,  so  sa  to 
oSer  no  great  resistance  ti<  ihc  tluw  tVuin  the  artitidal  nrlerii^  to  the  artificial 
vdns,  but  Iw  eo  arranged  that  thev  maj  be  made  narrow  by  the  .tcrewiuK -up 
of  clainporotherwiiic,  it  i^  pouibli;  tti  illuHtrutc  the  behavior  of  the  vascular 
luechamain  wben  iJie  i>eripliural  resiAtancL-  in  lt«s  ttinii  umiul  (and  &•  vv  »)iall 
•e«  later  on  it  is  poMible  in  the  living  organism  either  to  reduce  or  to  iiicrcajc 
wtiat  tnay  be  considered  as  the  norinnl  jieriplieral  nwiAiancft),  and  to  conijwre 
that  behavior  with  the  WhMvior  uf  the  inecbaiiium  wbon  the  pt-riphcral 
n«i«tauce  ia  iucreaMd. 

TIh!  wliole  apparatUK  being  placed  Bat  on  n  table.KO  as  to  avoid  dilTerenocs 
in  level  in  dillerc.nt  parta  of  it,  and  with  water,  but  so  ns  not  to  distviid  the 
tubing,  the  iwa  iniui<>inet«ra  attached,  one  (A)  to  the  arterial  si<lv  of  the 
tubing  and  the  other  (V)  to  the  vchoub  side,  ought  to  show  the  mercury 
■landing  at  eipinl  heights  in  both  Mmlw  of  both  iu^irumcnls,  since  nuthiae 
but  the  pressure  of  the  atmosphere  is  bearing  on  the  fluid  in  the  tubes,  ana 
tat  equally 
If,u<)w,thc 


that  equally  all  o\'er. 

J  pieces  b 
reaistiince  being  verv  little,  we  imitate  a  ventricular  beat  by  ihi?  stroke  of  the 


he  conni'cting  pieces  being  fn>oly  open,  that  is  to  say,  the  peripheral 


pump,  we  aliall  observt:  the  following :  Almost  inimediatefy  after  the  stroke 
the  ntercury  in  the  arterial  manometer  will  rise,  but  will  at  once  fall  again, 
and  very  shortly  afterward  the  mercury  in  the  venous  tube  will  in  a  similar 
loaiuier  rise  and  fall.  If  we  repeal  the?  stnikes  with  a  ni>i  too  rapid  rhythm, 
eaoh  stroke  having  the  same  furoe,  and  make,  h^  may  by  a  iiimple  contrivance 
be  eflevted.  the  two  manometers  write  du  the  Katue  i«coi-diug surface,  ne  shall 
obtuu  curves  like  those  of  Fig.  62,  A  and  V.     At  each  utroke  of  the  pump 


no.  an 


TaAOirai  T*SB(  PMM  AR  Annnnii.  9rniuni,  with  rax  FKHiruniAi  KnoBrunx  Suuur. 
A,ut«U:  V.  Tvuoui  nuiunnoler-   TlitiOiiure,  ui  wntiocc,  !•  m  t  ■nullwMSle  Ikan  tboror- 

n«poiidina  r%.  <y. 

the  mercury  in  the  arterial  manoineten  riaet,  but  forthwith  fnllt  again  to  or 
nearly  to  tlto  l>a»o  line;  no  mean  arterial  prcMum,  or  very  litth^  in  •■tabliibcd, 
The  cionieoi*  of  the  ventricle  ("yringiO  thrown  into  the  arterial  »v*t*tm  dis- 
bsnd  it,  but  the  jiMmgo  through  the  jieriphcml  region  is  no  free  that  an  cQiial 
quantity  of  fluid  pas*v«  through  to  the  veins  inimedintelv.  and  hence  the 
iDorcurv  nl  once  falls.  But  the  fluid  thux  pnxfing  casilv  into  the  veins  dis* 
taoda  tteao  too,  and  the  mercury  in  th<nr  manometer  rfsce  too.  but  only  to 
&U  Bguii,  as  a  corresponding  quantity  i^ines  from  the  ends  of  the  veins  into 
tbe  basio.  which  »ervo!i  as  an  artilicial  auricle.  Now  introduce  "  peripheral 
fesMtonoo"  by  screwing  up  the  clamps  on  the  connecting  tubes,  and  set  tbe 


TDK 


^■i[>to  «Drk  again  u  bcfure.  With  Uw  liret  vtroko  th«  nwrmry  in  tbe 
wuwil  Mnowrttw  (Fig. 68.  A')  riw  ks  before,  but  inHeadaffiUUiiff  rapidly 
t  bSk  alowlf.  becBiiw  it  now  uk«a  ■  longer  (imfi  for  a  quantity  of  flui^ 
iqMl  ta  thai  wliidi  hns  Wn  thrun  into  th«  arterial  snum  or  tl)i>  veutrica- 
«^i«ka  Id  |HUa  llirt>ii)(li  the  narroireiJ  |icri|ili«ra)  region.    Defore  ibe  mirre 


Pni.«. 


V 


twaw  T<as9  raoH  ui  AimnatL  Scmc,  wim  nrx  PranmiL  tUMmuta  OmnKiuHa. 
A'.  HMrlal ;  V>,  nnoaa  iia  mill  nil 

bwUIni  til  tbr  baw  lin«.  boforo  the  arterial  i^vtem  has  had  lime  to  dia- 

thai]gc  lhniu)[b  ibi-  narnivroil  iH<ri[ib?ml  rpgioa  aa  roitoh  lluii)  as  it  receinjd 

I^M  tha  TTOtrirl)',  a  woiiii)  Ktrukv  <lnvr»  more  fluid  into  the  urterieA,  dis- 

Mtfiac  ibrm  tbi*  limi-  inori*  ihnn  it  ilid  before,  aiul  raitiiiijt  lite  luereury  to 

a  ffill  ht);h«-r  l«Vfl.     A  thini,  a  foiirtli.  itnd  suoeeeding  Mriike-  ginxiuce  tbe 

■airrflcrt,  cxcejit  tliHt  tbe  tulililionul  Jveigfat  to  which  tbe  uifreurv  h  roitHHl 

•t  taeb  (trc^v  becomes  at  each  'trxke  le«s  and  )i?s8,  uulii  a  ntatv  i>f  Iblii)^  is 

nocfctd  ill  whieb  the  mercury,  briof;  uu  the  fnll  wbei)  ibe  ntruke  lalcvn  {>[ac«, 

ft  bf  tb«  Mnike  raiMii  juHt  as  bi);b  as  it  wa«  before,  and  tlieii  )i«f(intiiuj;  to 

Ua|P^  is  aicaiu  raised  just  as  bi^cb,  and  so  nil.     Witb  i.-Ath  siii'c«<diiig 

Mnlw  the  arterial  ByUem  has  becooK  mure  and  Riom  dixleixleil ;  but  the 

■en  ilisiMKled  it  is  the  Kreaier  ia  tbe  elastic  reutriiun  brougbt  iuto  play :  this 

flMcr  clastic  lettctinn  more  aiid  mora  overcoaKS  tbe  obstacle  proaoDt«()  by 

la*  fcHpbrral  mietance  and  driv»  the  fluid  more  and  inoro  rapidly  tbrouKii 

tht  i«npberal  refcion.    At  laMt  tb«  iirtcrial  systam  !■  so  distandoo,  aiid  tLe 

faftc  of  llie  elastie  rcmotioii  Mt  ffreal,  tbat  durinc  the  sirokv  and  tbe  sucoeeil* 

m(  iaurval  just  ua  mucli  fluid  ]>aNN,x>  ibraugh  tbe  peripliemi  r^^ion  M  oiitara 

tb>  ■ftJ'rtm  Mt  (he  ■ln>kir.     In  ntlier  vrimls,  the  rcpratt^l  ttruk'*  have  catab- 

bbtd  a  menu  anrrinl  iirawiire  which,  lit  ibc  |H>itil  where  the  mnnometor 

ii  sAsad,  is  raised  sligtilly  at  eneb  vMitneular  Hroku  and  falls  slightly 

b<t«m  1^  strokes. 

Iteaiag  now  u>  tbe  vcn<Mis  maiKviocter,  Fig.  6S  V ',  w»  observe  ibiu  each 


198 


v^ 


Ctmlcc  nf  the  pump  [>^}<iLlcca  on  itiin  much  less  ofTort  than  it  dit)  Iwfon  L_ 
intriKluclioii  of  the  iiicrcuwd  ])criphcml  raeiitAnce.  The  iiiercurr.  inntewl^ 
diftinoUy  rising  aiwl  faUiDg  at  ench  Htroke.  now  shows  nothing  more  th>n 
v«rv  gentle  uuduUtions  ;  it  fe«lB  to  n  very  slight  degree  onlr  the  dirf^i  plfe<4 
of  the  ventricular  stroke;  it  ia  simply  raised  slightly  nbore  the  base  line, 
and  rcmitinB  lairly  steady  at  this  level.  Tlie  sli;;!it  riae  marks  the  nieMl 
prenare  exerted  by  the  fluid  at  the  place  of  attaclioient  of  the  manometer. 
This  tDefln  "  venous  "  protHure  ia  a  continuation  ul'  the  mean  arterial  preeuure 
BO  obvious  in  the  arterial  nmnonaeter,  but  a  much  leu  tlian  that  because  a 
large  part  nf  the  arterial  mean  pressure  has  been  exi>eiideil  in  driving  the 
fluid  past  the  periphera!  reeistant-e.  What  reiuatDx  i*.  hciw«ver,  ttultideiit  to 
drive  the  fluid  aloiiji;  the  wide  venous  tubing;  ri^ht  t<>  llie  upcn  end. 

Tliud  ihii  aritfifial  niiidcl  may  be  made  to  illuntrat*!  liovr  il  comi:*  about 
that  ibe  bli)iii]  ttiivi*  in  the  artdrie*  at  a  nOativrly  high  pn^3t«ure.  which  at 
aach  ventrioulnr  )>yst<d«  in  mi»ed  (lightly  iilii)Vi\  lux)  at  ■■Jkch  diikdolc  falls 
slightly  t>ejiiw,  a  cttrtitiii  nicjin  lcvl^l,  and  llowii  in  thi^  vi-ini>  at  a  much  lower 
prt^Mure,  which  iiutt  not  tihi)W  thu  immcdi.itc  i'iret:l«  of  each  heart-hwit. 

If  two  ma nomut •.■»>,  instead  of  une.  were  atlAcheil  Irt  the  arlfriiil  *y»lcm, 
one  near  the  pump  and  (he  othor  further  ofl'.  close  to  the  peHpheml  miM- 
anct,  the  prrasuiv  shown  by  the  near  mnnomolcr  would  hf  fuund  U>  be  grralcr 
than  that  shown  by  the  far  one.  The  pressure  at  the  far  point  l*  l«M 
becaHio  some  of  the  pressure  exerlod  at  the  near  point  has  been  uwd  to  drive 
tlie  Huid  from  the  near  ]ioint  to  the  far  one.  .'Similarly  on  ihe  venous  ude,  a 
luaDomotor  placed  close  to  the  peripheral  region  would  show  a  higher  prea- 
aure  ibaD  that  shown  by  one  further  off,  beeaiise  il  is  the  pressure  still  remain- 
ing iu  the  veins  near  the  eapillariee  which,  assisted,  as  we  shall  see,  by  other 
cv«nts,  drives  the  bloud  onward  to  the  larger  veins.  The  blood-pressure  is 
nt  ilM  highest  at  the  root  of  the  aorta,  and  al  irjt  hiwott  at  th«  mouths  of  the 
Tcnii;  cnviL',  luid  is  falling  all  tbe  way  from  une  point  to  the  uthi-r,  because 
all  the  way  it  i.->  beting  usi-d  up  to  move  the  blool  from  one  point  tn  the  otlier. 
The  great  drop  of  prewure  i»,  a^  we  have  said,  in  tlie  pcrijiherai  n^on, 
because  more  work  has  to  be  dono  in  driving  tlic  l>l<x>d  through  this  rvgimi 
than  in  drlviiig  the  blood  from  the  heart  to  this  region,  or  from  this  region 
to  the  heart. 

Tbe  manometer  on  the  arterial  side  of  the  model  shows,  as  we  have  seea, 
an  (^'illation  of  pressure,  a  pulse  due  to  each  heart-l>eat,  and  the  same  pulse 
nay  be  felt  by  placing  a  finger,  or  rendered  visible  by  placing  a  light  lever, 
on  the  arterial  tube.  It  may  fbrther  be  seen  that  this  pulse  is  most  marked 
DMTMt  tlie  pump,  and  becomes  fainter  us  we  paw  to  the  periphery;  but  we 
must  reserve  the  features  of  the  pulsa  for  a  sjiei-ial  study.  On  the  venoiia 
side  of  the  miwlel  no  pulse  can  be  detected  by  tbe  manometer  or  bv  tbe 
Soger,  provided  that  the  [leripheral  re*i»tancebeadoi{uatc  If  tbeperipWrol 
NMStaocc  be  iliminished,  aif  tiv  uiiKCrewing  the  ctamjvt,  tbeti,  as  ueoeaaarily 
follows  from  what  bus  gixie  biifore,  the  pnlxe  psjiseii  o\-er  on  to  tlM  veixxM 
side;  and.  ns  w'l-  iihall  have  uccneinn  to  putnt  out  later  on,  tn  the  living 
organism  tlw  (>crij>b«'rHl  nvistancu  in  {mrticular  an>ai>  may  beat  linKtao 
much  lessened  that  a  distinct  pulsation  anpcJin  in  thv  win*. 

If  in  tlie  model,  when  tho  pump  !■  in  lull  swing,  and  arlvrial  pNifun.'  well 
eMabltiiied.  ibe  arlerial  tube  be  pricked  or  cut,  or  the  sninll  xidn  tulw  a 
be  opi-ned,  the  water  iiill  gij*h  out  in  jets,  as  dues  blood  from  a  cut  artery  tn 
the  livin/  iMidy ;  whereas,  if  the  venous  tulie  i>e  similarly  pricked  or  nil,  or 
the  small  lulie  r  t>e  ojieoeit,  the  water  will  simply  ooze  out  or  well  up,  as 
does  bliKxl  fnrni  a  vein  in  tbe  living  body.  If  the  arterial  tube  be  ligatured, 
it  will  swell  on  tin-  puniji  Bide  aud  shrink  on  the  jteripberal  side;  if  the 
venous  tube  W  ligatured,  jt  will  swell  on  tlie  side  Dearwt  the  capillaries  and 


TMK    MAIN    rACTS   OV    TltK   CI  KCL'LATIOS.  199 

•Kriak  on  the  atber  sidv.     In  short,  the  dead  iHDdol  will  tliuw  all  tli«  niiila 
fbrta  of  lh«  circuliition  which  w«  have  as  yet  described. 

{  m.  Id  tbc-  livinc  lioily.  hi>wever.  there  ore  certain  bel[is  l«  titv  oircalii- 
tioa  which  oaniiot  be  iiniimed  by  *v<-h  n  roodd  wilhuut  intmdnciug  great 
•ad  UiMledrRble  coiupIinaiuiiB ;  bul  ttine  diietl)'  ittri-vt  the  How  iilniig  tlio 
xtiBm. 

TIm  TviDS  uv  in  nuuir  placm  provided  vith  valvts  so  t'nnatrudod  as  to 

oAr  little  or  no  naiMance  to  ilie  llnw  from  the  cii|Mll«rios  to  tliv  liparc,  but 

aallv  to  block  a  reitirn  lowanl  lh«  eaplllarirs.     Hencv  may  cxtvra*] 

n  Drought  t'<  War  urHiii  ii  vein  U-nds  to  help  the  blood  to  mnvo  for- 

lownrd   the  Itrnrt.      In  tbt.-  various  mo  vera  en  tn  carried  out  bv  the 

1  mitK-li-f,  [>u<:h  an  exleninl  prcmiire  is  brought  to  bear  on  many  of 

vriii*.  and  1m-dc«-  tht-sc  niovcnients  imi«t  the  circulation.     Even  juiiiaive 

KioTrini-nla  nf  the  limbn  have  n  nmiltir  ef^t.     So,  also,  the  in ov emeu  is  of 

the  alintentarr  canal,  carried  out  by  means  of  jdain  muHOUlar  tissue,  promote 

ihe  6u*  aliMig  the  veins  coming  fnini  that  canal,  and  when  we  eouie  to  deal 

vtlh  tbr  spleen  we  shall  see  ihat   ihe  plain  muscular  fibres  which  are  so 

■htiadatit  in  that  organ  in  mnie  animids,  serve  by  rhythiuieal  contractiona 

toPsnip  Ihe  blood  re^ularlr  away  iVurn  the  spleeu  along  tbeipleuic  veins. 

Wlwo  we  t!oni«  to  deal  n'lth  respinilion,  ue  shall  see  that  each  enlargement 
rflJM  cbeu  constituting  lui  iDi>|iiniiiou  tends  to  draw  the  bl»o<l  tiiwanl  the 
that,  and  each  return  i>r  reiracliou  of  the  cliesi  walls  in  expiration  lends  to 
Mrs  the  bhiud  away  frotn  the  chnt.  The  nrrangenienl  i>f  the  valvi-»  nf  the 
ban  cauaea  thin  actiun  of  the  rt^iiiradiry  pump  li>  prriniuU'  the  How  of  blood 
io Ike dlrvctioti  uf  (l>e  normal  circiilaliun  ;  and,  inilc^il,  nen?  ihr  hciirl  per- 
iuljr  iDntinnl<M>,  tlie  working  of  this  rir«piraiorv  ptimp  atone  would  li.'iid  to 
itin  t)if>  btood  from  the  venit  oavie  tlirom^h  the  heart  iuio  the  nortu,  and  so 
In  ksMt  op  the  circiilalioii ;  the  force  so  exerted,  however,  would,  without 
iktiia  of  llie  iK-art,  b«  able  to  overcome  s  verv  »iuall  part  only  of  ihe  resist- 
lon  ta  Ihe  capillaries  and  snull  vessels  of  the  lungs,  and  so  would  prove 
idiislly  inefTectual. 

Tbefe  are,  then,  several  heljM  to  the  flow  along  the  veins,  but  it  must  be 

imnabered  that,  however  useful,  they  are  helps  ooIt.  and  not  the  real  cause 

tl  thi>  cimilaliou.    The  real  came  of  the  flow  is  tlte  ventricular  stroke,  and 

liii  i*  iofficient  to  drive  the  bliMnl  from  the  tel\  veiilricle  tu  the  right  auricle, 

when  every  muscle  of  tlie  Ixidy  i.i  at  nnl  aii<l  hmtlhing  ii>  for  a  while 

1,  when,  tlterefore,  all  tlte  hcl]i«  we  are  speaking  of  urc  wanting. 

CCVrcHMMtoiuvi  DettrmiHmg  the  Rale  of  (Ac  Flow. 
i  132.  We  aaj  now  nun  on  to  consider  briefly  the  rate  at  which  the  blood 
Of  through  the  vfmelt>.  and  fim  the  rate  of  flow  in  fA«r  artfrie*. 
Vhen  even  a  small  artery  is  severed,  a  ronsidcrnble  qiiantily  of  blood 
faapn  tr\na  the  proximal  cut  end  in  a  very  short  sjiaee  uf  time.  Thai  is  to 
■t,  ihe  blood  moves  in  tlie  arterira  from  the  iiearl  lo  the  capillaries  with  a 
Tfty  ninaidemble  velocity.  By  various  methods,  this  velocity  of  the  blood- 
annir  ha*  been  measured  at  diflerent  parts  of  the  arterial  systein:  llie 
■»oli>,  owinK  to  iinpeifi'<-lio<u»  in  tlte  meibods  employed,  cannot  be  regarded 
m  Mtldaii'irily  exact,  iHit  may  be  Bi-cefneil  as  approximately  true.  They 
sluiw  that  the  vd'M-itv  of  the  arterial  >tivani  u.  greutnt  in  ihr  largest  aiteriea 
acar  the  heart,  and  liiniini^lxv  from  Ihe  hmn  toward  the  cajiillari(«.  TbuiL 
ba  UtYT  artery  of  n  Inrgi-  atiiinal.sucfa  a»th«  carotid  of  a  dog  or  hone,  and 
jirshab^  in  the  carotid  of  ii  niiiti,  thi-  I>Ioih1  Howm  ai  t)ic  rate  of  SOU  or  oOO 
■u.  a  irroud.  In  ibi<  very  tmull  arteries  Ihe  rale  i*  probably  only  m  ftw 
mtaiceaiKL 


£00 


yfrthaiii.  The  bicmndmiaiiTnelcr  nf  Vnifamann.  [t'ig.SI.]  An  •Hrry— '.  y..  » 
carotid— in  rlnmpod  in  two  pliCM.  ntid  dividi-d  bclwecii  thrclonip*.  TwocanulM, 
of  s  b<)r<!  an  iiMirly  e4unl  ni  riuMible  to  tbut  urtbo  urterv.  or  of  ■  Icddwd  Irotf.  mre 
Inaetti-il  iii  ilie  two  i-nds.  Tbe  two  cauulie  iiri-  cotiiiecieJ  by  mi'iuu  of  two  siop- 
coclCD.  whii'h  work  togtxher.  wiili  Ibe  two  endit  of  a  long  ^last  lube.  b«i)t  in  iltD 
Rhnpo  of  It  U.  and  filled  nilh  nnrmnl  inlino  Holutinn.  r>r  wilh  a  calorri)  inn<icui>a* 
fluid.  The  clnmpK  on  the  uricrv  lieini;  rnlciwud,  «  turn  of  the  stoficiwk*  pennit* 
tbe  blood  to  ealvt  the  proximuf  end  of  ibe  lone  U'lul^i  along  which  it  MMirae*. 
driTing  tbe  fluid  out  Into  ib«  arterj'  throuub  tlie  dUlnl  «iiil.  Attached  to  the 
tube  !■  a  graduiil^d  scale,  by  ii)e«ns  of  wbiiili  Ihe  vclociiv  wiih  which  iho  blood 
llovra  along  the  l<ib(  mny  bo  rpod  ofl'.  Even  vupjiwiiig  the  cnnulie  xa  he  of  tbe 
•ame  borp  im  Ihr  iirlorv.  it  in  evident  that  tbe  oenditioiis  of  the  flow  ibrouch  ihe 
tube  are  BUch  w  will  only  aduiit  of  the  result  tliuii  gained  being  coutlderea  »«  an 
approximative  eitimatlaa  of  the  real  veloolty  lu  the  artery  llselT. 

I  Flo.  M. 


/ 


7=" 


/ 


w 


J 


VnumASir*!  HjoiiniioianiicriEu. 
"nn  ronlaJ  [■mumi  i-i  <1<d  ln<tnimaii(  an  Inwrlvl  hi  ilii-  i-ot  gn<ti  of*  rein  or  MHrr.    Rjrl 
dMpIc  utameninclil  of  n  dbulilo  uoiixick  Iho  bloal-ciiiTciil  can  Lc  mule  l-i  T'Uk  ImniadlMcty 
UuDivli  tlw  i"aiT*n*  am,  •■  111  A,  or  (n  )dM  [littiugb  ilioBailiiaMU-thapod  tube,  w  lull.] 

The  rheomeler  (Slrorauhr)  of  T.iidnig.  Thii  cornuo*  of  two  glan  bulb*.  J  nixt 
B,  Kir.  C5,GamiiiunicatinK  Hbovc  with  eueh  other  Hnri  with  the  common  tube  '*, 
by  which  ^ey  can  be  filled.  Their  I'lwi-r  end*  arc  llxed  in  the  metal  d)«c  b. 
Wbii-h  can  be  mftde  to  ruUte,  through  two  right  anglea.  round  the  lorrt^r  dine  B. 
In  Ihe  upper  dlftc  are  two  hole?,  a  and  b.  cnnlinaon*  wlib  A  aod  B  rtejiectively, 
and  in  the  lower  di*c  are  Iwo  nimiliir  hole*,  a'  and  h'.  limilHrly  continuous  with 
tbe  tub«e  G  nnd  //.  Hence,  in  the  ptwition  of  the  dliirs  tthown  in  the  flgure.  the 
labe  (1  i"  conlinuou*  throueh  the  two  diao*  with  the  bulb  J,  and  the  luhe // 
vilb  the  Ifulb  B.  On  luming  tlie  diK-  D  thtbii):b  two  ri^jht  anplei.  tbe  tube  Q 
beoonea  contlnoou*  with  R  insieud  of  A.  and  the  tube  fl  with  A  Jmlead  of  B. 
There  b  a  further  armngemeni.  omitied  fioni  the  fiKuro  for  tbe  ntkeof  oimplieitjr, 
bv  which  when  the  dii>e  />iii  turned  Lhrou;:h  one  iniilend  of  two  right  anflea  from 
eilbcr  of  (he  alHire  poiiitioiiii.  fl  brevniw  directly  cuiilinuoiiii  with  H,  boib  being 
campletely  shut  olT  from  the  bulb*. 


TIIK    MAIS    KACTS  Of  TIIK  CI  K<ULAT10K. 


201 


Tb*  niila  hT  llie  iub«  H  and  O  an  oiute  (o  fit  exnclly  into  tmi  c«du1»  iiwrttd 
I  lb*  i«»  cni  enib  of  Ibe  »,nttj  ubnut  to  ti«  eiptvi mealed  upon,  and  Uavio);  a 
I  BMrlf  *(|iia1  u  jiOMibl«  t(>  Umt  of  tti«  artery. 


FM-tt. 


^< 


:5te- 


Lrwvti>>  Svaomnu  did  t  DiAi.aAXiMttc  IlKranarrtnoK  or  Tiik  i*xt. 

Ttt  sirtbod  of  experimcDlin^  Ih  ho  follows ;  The  dim*  D,  liciiig  pl«c«d  in  thv 
IHmiillal*  pontion.  tn  ibai  u  and  h  nrp  liotli  cut  olT  from  «'  and  b',  tin-  bulb  .1 
ii  DM  whb  pun  olive  nil  up  l'>  thi.'  mnrk  x.  and  Ibc  bulb  B,  tlie  rrst  of  A.  aud 
Itejuncilon  C,  viib  JclilriDnli'd  blood;  aad  V  M  tbcn  clampnl.  Tbe  tube*  II 
ni'itntiao  Bll«il  with  dclibtiiiiit«d  b1u<Hl,  ami  0  U  inaWod  into  tbe  canul* 
if  tt(  tMlral,  B  into  thai  of  the  i>eritib«rBl,  end  of  tiiv  iirt«r>-.  On  rcmuviDic 
Aadmn  from  tlw  arWry  the  blood  Bom  lbrouj;li  O  to  //,  mid  an  bark  into  tbe 
•fifty.  Tbe  obavtrraiioD  now  brgins  by  taniltig  the  due  D  into  thr  poailioa 
•km  ia  the  (iiture;  ibe  blood  tbrii  fltwi  inln  .1.  drinng  tbi-  oil  there  I'lmtaini^il 
«tWfor«  It  into  iIm  bulb  B,  iu  tbv  dircclioD  of  tbr  nnon-.  Ibe  dofibrliMied  blood 
"' — \j  pnwBt  In  B  poaunc  by  H  inlu  tin.'  iirtrrj.  and  au  into  tbe  nataoi.  At 
HMftit  tbat  Ihc  blood  la  an-n  la  irae  to  Ibe  mark  x,  ttie  disc  Dw  with  all 
lie  fsptilitv  tunieil  Ibrougb  two  ri|t;bi  noglea :  and  thiia  the  bulb  B.  now 
J  ftlltd  viib  oil,  placr<l  jn  commii nidation  nilh  O.  Tbe  blood-rtreum  DOW 
lira  tbe  nil  hack  iiilo  .f .  aitd  tliu  new  blood  in  .1  tbrouicb  II  into  ibe  arler^. 
Xumm'a  1.1  ibi-  nil  ban  wholly  tvtuinvd  lo  ita  original  [Haitioii.  the  iltM  {a  agnm 
Rrii  ind  A  raiev  taorr  placed  ia  conmunlcallon  with  O,  and  the  oil  onc« 

ma-  ,  :r<>m  A  to  It.     j^hd  tbts  la  repeated  aeveral  tinici.  jndrcd  eenerally 

■bJ  Utr  i-li'iiinK  if  lb«  blood  (It  ih«>  ailmixttire  nf  tbo  oil  with  Ibr  bloud  iiuta  an 
tu  Ibr  eiiicriEnrnt.     Tbiia  tbo  (low  nf  bl<)o<t  i*  uied  Iu  fill  uttcrtiat«ly  Willi 
'  HT  «dl  tbe  ainiv  of  the  iMilb  A,  whuac  caviiy  a*  far  ■■  the  maik  x  biu  Wen 
,'  MMHured  ;  boni-L'  if  ibu  imiubct  of  linitn  in  aay  j|;lve»  time  tlie  dUc  D 
ke  lurneil  nxind  bi-  kuowD,  the  uuinbcr  of  line*  A  baa  beoa  filled  b  alao 
a,  aad  tbn>  ilio  quaniity  of  blooil  wbti-h  baa  paatod  in  thai  time  througb 
Hia  connrftt-d  with  ihe  tube  O  in  directly  meanurcd.    For  instance,  an p- 
;lluit  ih<-  'piNKlily  hrUI  by  Ihc  Uiilb  J  when  tille'I  up  to  the  mark  z  iaSce,, 

,,  tj,„{  |',„g,  ti,^  moment  of  allowiog  Ibe  dxtX  li  c.c.  of  b1'>od  tn  b<f  in 

it<«  to  the  monienl  when  tbeCKa{>e  of  Ibe  laat  !^  c,c.  fmra  the  artery 
.    ;...  .    *■■  eoniplcte.  M)  Hconda  bad  elatwrd.  dnrinc  »bich  time  A  ex. 
'kal  been  recvived  ten  timea  into  tbe  tube  from  tbe  arte/y  (all  but  tbetaatG  c.c. 


'Mi 


THE    VASCILAR    MECHANISM. 


W\it)(  rcluriietl  inti>  ihe  dit>(al  |>ortioD  of  the  artery),  obviously  0.5  c.c.  of  blood 
liHil  Hl>^^'t^<l  t'miu  the  pruiimkl  a«ctiuD  of  the  anerj  id  one  Mcood.  Heoce,  up- 
)>iniiii>;  ilint  tW  diameter  uf  the  caDulK'(and  of  the  nrtery ,  the;  being  the  bum] 
were  2  mm.,  with  area  Ibt-refure  of  3.14  wguare  mm.,  an  outflow  tbroueh  the  tec- 
liiiii  iif  (t.f)  i-.o.  <>r  .MHi  cm.  in  h  lecond  would  give  (?"'')  a  Telocity  of  about  ISt 
mm.  ill  H  niHiinil. 

'I'lic  linnmilHi'liometer  of  Viemrdi  [Fig.  66]  is  constructed  on  the  principle  of 
iiii'iiHuriti);  the  vt'locitv  of  Ihe  current  bv  observing  the  amount  of  deviation  nudet- 
>I<iiLit  by  u  )H>iidiiliim.  the  tree  end  of  irbich  b»nga  loosely  ia  the  stream.  A  sqnsn 
or  reotangutar  chamber,  une  side  of  which  is  of  iIm 
anil  marked  with  a  graduated  scale  in  the  form  ot  *a 
an-  iif  a  circle,  is  coonected  by  means  of  two  slwrt 
tuliea  i(ith  the  two  cut  ends  of  an  artery ;  tiie  blood 
ciitige>|uently  Howh  from  the  proximal  (centrml)  px- 
lion  of  the  artery  through  the  chamber  into  the  disti] 
^H    II       ''  -^t  I  )'«>i'tion  of  the  artery.     Within  the  chamber  and  wf 

^\  '^  '\^^\   I  l«'inW  fri>m  its  roof  is  a  short  pendulum,  which  when 

I  ''jiji^J^^M  f  ||],>  b!iH>d-»tream  is  cut  off  from  the  chamber  huigi 

miitionkwH  in  a  vertical  position,  but  when  the  blood 
is  allowed  to  flow  through  the  chamber,  is  driven b; 
the  fon'e  of  the  current  out  of  its  position  of  rest.  Tbi 
iiriiiliiliiiii  in  i>o  |i1m'tit  lliMt  a  murker  attached  to  its  free  end  travels  close  to  [be 
joiii-r  HiirfiiiT  of  till'  glitMi  nidf  aUDig  tlie  arc  of  the  graduated  side.  Hence  tlie 
himiiuiit  iif  deviulioh  fMUi  u  vertical  position  may  easily  be  read  off  on  the  ictle 
(rum  (111-  ouliiile.  The  graduation  of  the  scale  having  been  carried  out  by  eiperi' 
iiii'iitlii^'  nitli  HircnuiH  of  known  velocity,  the  velocity  can  at  once  be  calcalited 
lioiiL  [lii>  iiiiiiMiiil  of  ilevialion. 

All  iiiiilnimeiil  liiiMi-d  on  the  siime  |>riiK'iplc  has  been  invented  byCbauveanud 
ii»i>tovi-d  liv  l.orli't,  Kif;.  tiT.  In  Ilii^i  the  part  which  correeponds  to  the  pend alum 
ill  N'iri'oiill'i'  iiiKtruno'iit  is  prolonged  onteide  the  chamber,  and  thus  the  portion 
ullliiii  till'  rliHinlii'r  is  iiiBik'  to  form  the  fhort  arm  of  a  lever,  the  fulcrum  of  whiti 
in  111  ilie  point  nhiTi-  ilie  wall  of  the  chiimlier  is  traversed,  and  the  long  arm  oi 


n  I  yi  VI  M  nitMi  LI  i;  ^ii    V  i>k- 

■  PIII'l.       11.  I'.  »11<  Mil  to '11-11-^  ] 


Kii.,  67. 


1!  1  ^IMAi-lllOll.n.Jl  Ml^  f'llA^'VKAU    AM>  LliRTET. 


»  Nii'li  iiiiijn  In  on(Hi<]<',  A  soniewliat  wide  tube,  the  wall  of  which  is  at  one  poiD* 
i'iiiii|io?>i'<l  i>f  nil  I  III  lilt  riiUKiT  iiiembranc,  is  Introduced  between  the  two  cut  ^**? 
Ill  111!  til  ii-r> ,  \  hnin  lij-lii  K'vcr  pierces  the  India  rubber  membrane.  The  Aot* 
ixiiiiiiiliil  HI  111  III  lliin  IfViT  jirojirliiig  within  the  tube  is  moved  on  its  fuleruni  »" 
ilu'  hidiii  iiililiir  riiij:  liy  llie  cnrrciit  of  blood  passing  through  the  lube,  ^"^ 
jiu'-ati'i  ihv  u-loi-iiy  of  lli'e  current,  the  larger  being  the  eicursion  of  the  lever- 


TOE   MAIir    PACTS  OT  THE  CI  KCfLATtO.V. 


n>  BMnnila  <iT  tb*  ihitrt  anii  glT«  ri»e  to  fxMTMpoiuliiig  iiioir«nirnli  in  the 
Iffrito  dlractkm  at  the  loag  um  buu)d«  ilie  tube,  and  ititac,  hj  ni«iiis  of  u 
BWlW  MUcbMl  to  tilt  end  of  ibr  long  arm,  nirty  bv  dir<>i:tlr  iriiicriticil  »n  ti 
NCMliaf  MufiiCr,  Thin  iniitriiRivnl  i*  vrr^  wall  iwh|ic«(l  Tor  nfa^trliiK  chmiffra 
It  tW  t«Ificlt]r  of  till'  flow.  In  drtcrmininK  kctditl  vvlocilics,  for  whicli  |>ur)>i(te 
h  tai  to  be  exfiertnraullr  gnuluat«d,  it  U  not  k>  tueftil. 

la  tbt  capUiarw,  llifl  mio  ia  Rtowmt  of  all.  In  lh<>  w«l>  nf  ihv  frag  th« 
Im  u  iudgeil  Ur  tho  movement  of  the  md  corptisclfw  mny  \k  diroctljr 
■■MfM  ua<ler  the  microeeope  br  me«ti8  <>r  n  mk-romvter,  anil  i»  fuuml  to 
U  iboul  half  ■  millimelrv  io  a  wmad ;  but  this  it  pmlitiMy  a  tour  t-slitnnttf, 
or*  h  m  ofilr  when  th«  rircnlstion  ia  somewhnt  slow,  slovrvr  [nrrhiiiw  thin 
ilal  oQffht  Ut  he  cotiaidered  the  normal  rale,  that  the  red  coriNifclea  cnti  Iw 
ditiliMljr  seeB.  In  the  mummnl  th«  mle  has  been  (Miniated  at  ibout  <J.7j^ 
lAliaaMrM  *  »ecoa'l.  but  U  pmbubly  ()Liiclcer  than  even  ihia. 

At  nnnts  tAe  rein*,  llie  flow  b  verj  aIuw  in  the  small  veins  eiuert;ii)t;  from 
Aa(H|dTlann,  but  JncreueiM  these  join  into  larger  truuk;*,  <intil  iu  «  larj^e 
WD.  rtirh  aa  ibe  iuK>ilar  <if  the  diij;,  the  rut*  is  ai>out  200  tnm   a  »ec()ii<l. 

ilSS.  It  will  lie  neci).  tliMi.  that  the  vcliidtj  of  the  tb>w  i.->  in  itiTenw 
fnfOrtkM)  to  the  width  nf  the  bt-d,  Ui  the  united  nectional  nrtOM  nf  the 
HML  It  i>  grMlr*t  at  the  aiirta,  it  diminuht*  aloD);  the  arlerial  xyKtcm  to 
tb» (Kpillarki.  to  the  imiicd  baaei  of  theconw  «|H>ktii  of  in  §  112,  wliere  it 
iltwi,BiKl  fimm  theniv  inenttmi  again  along  thv.  venotu  avRleni. 

XaA,  EimIhhI.  it  ix  tbi"  width  i>f  the  bed,  and  thi>  nl»n«.  which  tl«tcrmi»es 
ibevowrW  ve|i)eil_vi>ril)c  flow  nt  variou*  [)artii  of  the  ayrtem.  The  »lownc« 
it  Ike  flaw  ill  ibe  niplliiriea  u  not  due  to  there  Iteiiig  »o  much  more  friction 
htWir  narrow  cbanii«U  tbnn  in  the  wider  mnaU  nf  the  larp-r  arierif*. 
r«  lW  [•eripfaeml  reeisiance  atusctl  by  tho  IriotiuD  in  the  capilinriu>  and 
•■all  arleriea  ia  «ii  obuaele  not  only  to  the  flow  of  blo<xl  thrciti>;h  ibe»e  xmail 
nawb  where  the  rCMMaoee  b  actually  generated,  but  also  tn  tlte  escape  of 
thg  bliNxl  fVoni  the  Urge  into  tlie  small  arlcried.  and  indec<l  from  (be  nenrt 
iMtlW  Iwve  arteries.  It  eserta  ita  influence  alont;  the  whole  arterial  iraet. 
Aail  !i  \t  i^viouH  ilini  if  it  were  this  peripheral  rrsialanoe  which  cheeked 
tbf  flini  in  the  cnpillnriM,  then  could  be  no  recovery  of  velocity  along  the 
now*  tract. 

lit  lilood  ia  flowing  through  a  cloaeil  aratera  of  tubea,  the  blooilreiHeK  under 
tkr  influence  of  one  propelling  fi>n-e,  the  svstole  of  the  ventricle,  fbr  tliis  is 
llw  li>rfe  which  dri<rc*  the  bliHHl  from  ^-vutriett?  to  auricle,  though,  an  we  have 
■■■.iltaetlaDWmialifierl  in  thi- >eveml  parU  of  Ihesyatem.  In  xiich  a  >y>tem 
AtaiM  <)aantity  nf  fluid  muni  gum  each  aecllon  of  the  «)-*ti<in  at  the  wim« 
!(■(,  nthrrwiai-  ihen-  would  Iw  a  block  nt  one  place  and  a  deficiency  at 
i»<tkrr.  If,  for  in«tanev.  a  fluid  is  ma<le  to  flow  by  some  one  Ibroe,  premurc^ 
M  fravlir  ibrough  a  tulw  A  (Fig.  W)  with  nn  eHl«r;g«aH-n(  B,  it  i»  obrioui 
iW  the  *ame  quantity  of  fluid  miL<t  pan 
<^n^b  tbe  taction  h  os  \»bk*  through  the 
wii*  a  in  lh«  mme  tttne— for  insinnce.  » 
wa*4.  Othcrviec,  if  leas  panea  thrmigh  b 
tJaa  a,  tbe  fliiid  wuuld  aceumtilate  in  B,  or 
V*M«.  B  would  be  emptied.  In  the  same 
'<  juU  ea  much  lausl  y»^  tn  the  nntc  tinte 

■ifh  tlie  aeciioB  c  u  paasea  through  a  or 
t".    ikit  if  ju"(  ft*  many  particle*  of  water 

hm  U'  get  through  the  unTnui  teetiim  a  in  the  «ame  time  n*  tbey  have  to 
(H  ihruugli  the  br'vi>!er  'eeiiiin  v.  they  mutt  move  <)nirki-r  lhfi<iii;h  a  than 
linM^b  c,  or  more  nlowly  thmiigh  c  ihnn  thrutigh  m.  Fur  lh»  oamr  r<-iuion 
flawing  along  a  river  impelled  hy  ana  fbrc« — vix..  that  of  gravity — 


FU.  S1L 


904 


nisltea  ntpidly  ihitiuiijh  a  "nnrrovf"  nni]  flows  sluegUlily  wlieii  ilic  rivor 
widens  oui  iiiio  a  "  bruail."  The  flow  tbrotigb  B  will  be  iimilarly  9lack<*»cd 
if  B,  instead  of  beioft  simply  a  smgh  enlarge  men  I  of  tlic  tulie  A,  couslstK  of 
a  number  of  small  liibeti  hraiioliiu^  out  from  A,  wilti  a  uuiied  wHlioiial  nrra 
neater  Uiau  the  seclioiwl  area  of  A.  fr)  i-aeh  of  auch  smmll  tulxw.  nl  tbo 
nn«  c,  for  instuiire,  the  Row  will  be  ^lawer  thitu  at  a,  wlierc  the  *ranll  tubci> 
branch  out  from  A,  or  at  h,  wliere  they  join  RKsin  to  form  n  MR^le  labo. 
Heiicv  it  is  thai  iho  blood  rushes  swiflly  through  Lh<-  nrliu-i»,  tarrm  slowljr 
through  the  citgiillarius,  but  ipiickeiis  il*  |inco  i^aiii  in  ttie  vdi». 

An  apparent  wnlradii'tion  to  thiH  principle  t-tint  tliv  rat^  of  flow  in  depoo- 
dont  ou  the  widlli  of  the  bed  Ls  srcri  in  the  emu  wlivrv,  the  fluid  having 
allemativu  mutra,  one  of  the  route*  U  temporarily  widcmxl.  Suppose  a  tuM 
A  dividing  into  two  brnncbes  of  equal  length  x  and  y  which  unite  again  to 
form  the  tube  T.  Suppose,  to  stnrt  with,  that  J;  and  y  are  nf  equal  diameter; 
then  tlio  resistance  oHi^rcd  by  each  bein^  equal,  the  tli>w  nill  be  equally 
rapid  through  the  two.  being  juet  to  rapid  that  as  mucli  fluid  dbmcs  ta  a 
eiven  lime  tbrotij^h  r  and  y  together  a;^  pas8L«  thmugh  A  or  tnrough  f. 
But  Don'  suppose  II  to  be  widened  ;  the  widening  will  diminish  the  re«i!taDoe 
ofler«d  by  y.  nnd  in  cotiseqaeooe,  supposing  that  no  material  chnnge  lake* 
place  in  the  pra^ui'e  or  furct>  which  is  driving  the  fluid  along,  more  fluid  nitl 
now  \Mae  alonj;  t^  in  a  Kiven  time  than  did  before ;  that  is  to  say,  the  raptdi^ 
of  the  flow  in  ,v  *^'>11  h^  incn-ased.  It  will  be  increased  at  the  expense  of  the 
flow  thruu);h  ^,  since  it  will  still  hold  good  that  the  flow  through  f  and  y 
together  is  equal  to  the  flow  through  .4  and  through  I'.  We  shall  hare 
occasion  later  on  to  point  out  that  u  vmall  arlery,  or  a  set  of  small  artertee, 
Diay  lie  more  or  Inat  suddenly  widened  without  materi<llv  affecting  the 
general  bhMKl-jjrWMUr^  which  is  ilriving  the  blood  through  the  artery  or  set 
of  ait«'rii».  In  such  caaea  the  flow  of  blooil  l.hrongh  thi-  widt-nvd  artery  or 
arteries  is  lor  the  lime  bein;^  increased  in  rapidity,  not  only  in  »{utc  of,  but 
actually  in  consequence  of.  the  artery  beinK  widened. 

[t  must  be  understood  in  fact  that  this  dependence  of  lite  rapidity  of  tlie 
Sow  on  the  width  of  the  bed  applies  to  the  general  rate  of  flow  of  the  whole 
circulation,  and  that,  besides  the  above  instance,  other  special  and  trmporary 
varttilions  occur  due  to  particular  circumstances.  Thus  cJianges  of  pressure 
may  alter  the  rnjiidity  of  flow.  The  cause  of  the  How  through  l)i«  whole 
system  is  the  prmsnrc  of  the  ventrtt^ular  systole  mauitesied  as  what  we  have 
Qklled  blood- pre»u  re.  At  each  point  alou^  the  system  nearer  the  left 
veotxiole,  and  therefore  f\irlbcr  from  the  right  auricle,  the  pressure  is  greater 
than  at  a  point  further  fVoni  the  left  veutricTe  and  so  nearer  the  right  aurirle ; 
it  is  this  aitTcrenoc  of  prewure  which  id  the  real  cause  of  the  flow  from  the 
WW  p(^nt  li>  tlic  other;  and  other  things  being  equal  the  rapidity  of  the  flow 
will  depend  on  the  umounl  of  the  diiPcrence  of  pn!*ture.  Uence.  temporary 
or  local  variatiorm  in  rapiditv  of  flow  way  he  cau*cii  by  the  eatai)li»lunent 
ftf  IciDitorar}-  or  local  diflcrcnccs  of  prewure.  For  (example,  at  any  point 
«l<mg  the  arterial  itystem  the  How  is  incrcjiixil  in  rajiidity  during  the  tern* 

Sorary  incri'ase  of  preeture  due  to  the  ventricular  ayntole,  i.  r^  the  puUe,  and 
iminishcd  during  the  sulmcqueiit  Icmpnniry  dccrcn»i%  the  increaie  and 
deorease  being  the  more  marked  the  n<Mrcr  the  point  to  the  heart.  And  we 
•liaU  probnbly  meet  Inter  on  with  other  mstnncefl. 

S  IS4.  Time  of  Ifie  ftitirv  Mmiil.  It  is  obvious  from  ihu  for^>ing  that  a 
red  corpuscle  in  j>erforming  the  whole  circuit,  in  travilling  Irom  the  lel\ 
venlricle  back  to  the  left  ventricle,  would  spend  a  large  portion  of  it*  limo 
in  the  eapillarivs.  uiinule  arteries,  and  vetne.  The  eniirc  time  taken  up  in 
the  whole  cin-uil  has  been  approximately  attimaled  by  measuring  the  time  it 
takes  for  an  ca»ily  recoguiied  clieuical  substance  at^r  itijectioD  into  the 


TltK    MAIS    FACTS   OF  THE   CIRCULATION'. 


205 


» 


I 


Jnnkr  nin  of  one  aide  to  «ppesr  in  lh«  blood  of  ilie  jugular  v«io  of  the 
olWaiift. 

Wlii1«MBklI')iunllti«  (if  blood  an*  being  ilrawn  at  fiei)U«Dtl7  r«i)eaf«d  iut«rriilB 
A«fn  thp  jufnlar  vein  of  iin^Hiclc.  or  wlillf  Uieblowl  from  the  voin  Uboing  allovc^l 
«0  bll  in  a  uiiiiutr  Klrraui  on  in  ahaotbrnt  paper  cnverinK  loatti  traTrlUug  xurfacc, 
tfa  Imn  nit  mrli  aa  putamiiim  rrrrncyiniiJi'  (or  iinrfcrably  loiJiutn  frrrric^rnniile  ■« 
BMtiag  nora  innoruoiii)  b  injectPil  iiii'o  tlie  jugular  vrin  of  theotlit'r  nide.  If  Uie 
siwfl  of  tb«  Injecltod  be  Doled,  and  ibo  time  nder  Ibe  Injection  into  one  aide  at 
«i|iidi  vniltaco  of  the  pratVRca  of  (be  iron  aalt  can  bv  detected  in  tho  aaniple  of 
l>too<l  fron  llic  Tpio  of  the  fltber  lidr  ))«  nntod,  tbi*  Ki*^*"  tbr  time  it  baa  taken  ibe 
«aU  tm  pflrCwm  Ibe  cin-uit ;  and  on  the  «uppwiitiun  that  mere  difTuiiioB  doea  not 

anlwUly  aifrct  Ibc  n>«uli,  tbe  time  nblcb  it  takca  tbc  blood  lo  perform  tlte  tame 

dftaH  i«  ihenby  girvn. 

In  the  hone  Hub  time  baa  been  experinieDlallr  detenoined  at  about  30 
■MMwb  moA  ia  the  dog  at  about  IG  eecuada.  In  man  it  ia  ]>robablv  from  20 
10  35  wteuoda. 

TtkloK  the  mio  of  flow  ilirou(;b  tb«  capillaries  at  about  I  iniu.  a  second  it 
•uM  tue  ■  oorpuiwlc  as  lou^  a  time  lo  net  ihrouifU  about  20  miti.  of  capil- 
bm  na  to  perforin  (he  wbole  ciriMiit.  Ileo<«,  if  aiir  corpuscle  bad  iu  iu 
cinBlt  to  poaB  ibroui^b  10  iiiiu.  of  rapillariiis.  balf  ibe  abole  time  of  ila 
jmef  would  be  spent  in  the  narrow  obuiinelR  uf  the  capillarieiL  Iniuinticb 
aiW  iMir]nee0  served  by  ibe  bluod  are  ebietljr  carried  uut  i»  the  c-apillariv*, 
it  ii  oWiouslf  uf  Btlvaiilage  tbat  iU  atair  in  them  should  be  |>ruliiii^il. 
Hon,  bnwerer,  the  avera)|:v  leiiEtli  of  a  capilWy  is  sbout  O.S  mm.,  nlK>ut 
UfaieKind  isspeui  in  tbe  atpillaries  of  the  lIsHuex  and  another  half  tecond 
is  the  oapillMries  of  the  lunjpt. 

iUtSi  We  BIST  now  briefly  fuiuniariM'  tlio  broud  f«iturt»  of  the  dreulH' 
oco,  vhicli  Kc  bavr  wen  may  be  explained  on  purely  ph)>i«it  nrindples,  it 
biWuKiinex)  Ihat  the  ventricle  delivers  a  eerlnin  quanlUy  of  blond  nilh  a 
(ffUui  force  int'>  ih*  aorta  al  regular  intervals,  and  tliat  the  physical  pro|>- 
ettki  of  th«  btoodvcen-ls  remain  the  eame. 

Ws  bare  seen  that  owing  to  tho  poriphervl  rvcislanee  ofl'ered  by  the  cap)'' 
IniaaadKnall  vnseI»lhedi>Fvteflectof  ibe  ventricular  stroke  is  to  establisb 
to  tlie  artAries  a  mean  arterial  premiire  which  is  greatest  at  the  root  of  tbe 
aorta  and  diminishes  lowsrd  the  small  arieries,  some  of  it  bcinj*  useil  up  to 
4rffs  ibe  blood  from  the  aorta  to  the  small  arteries,  but  which  retains  at  tbe 
n|>M  of  the  small  arteria  euffldeiit  power  lo  drive  through  tbe  small 
sttHin.capillanci'.  and  reins  jusi  as  much  blood  as  is  beioE  thrown  into  the 
aula  by  the  ventrirular  strukt-.  We  have  seen,  further,  that  iu  the  large 
ift«i«  at  eaeb  stroke  ibe  proauro  lUiti  and  fnlla  a  little  above  and  belov 
tisHMan,  tbu--  omstiluiitig  tbe  puW,  but  ihai  thti  vxm  dbtension  with  tla 
•okuteat  recoil  dtminisbca  along  tlie  arterial  ltbci  and  liuallr  vaimlua ;  it 
diaiaUies  and  vaulBhes  beoiuise  it  loo,  like  the  wliole  force  uf  tlie  ventricular 
Hnlw,  of  a  fraction  of  which  it  i*  the  cxprcMtioti,  in  i»ed  up  in  eatabliohing 
tka  nam  pranure:  we  «hall,  however,  coiinder  ngnin  later  on  the  «jiecial 
falaras  of  ihU  pulse.  We  havi;  sura,  further,  ibnt  tbe  laak  of  driving  tbe 
Uwd  through  thi*  ]H'ripl>i.-nil  rmslnnee  of  tbe  sniall  arlerii.ii  and  canilTaries 
nOMiiBea  much  of  this  im-an  pmuiure,  which  ooiuequently  t*  much  \v»  in 
■Wsmtll  teioH  than  in  ibo  en rrc« ponding  rmall  arterii.v,  but  ihat  sullicienl 
HBahv  l»  drive  the  blinx),  even  without  tl>e  help  of  tbe  auxiliary  agenU 
*Ueb  arv  generally  in  action,  from  the  small  vetos  right  back  to  the  auricle. 
Ui^^  wtliav*  seen  Ibnt  while  tbe  aliovo  ia  ihe  cause  of  the  Bow  from 
vnlnde  to  auricle,  lh>-  cban^iing  rale  of  the  How,  the  diuiininbin^  nwiftncsa 
ia  ths  arterini,  the  sluf^fpoh  crawl  through  the  ciipillarice,  Ibe  incrcnung 


20ii 


THE    VASCl'I.AR    M  BCIl  AN'liiM  , 


qoicknesB  through  the  veins  are  determined  by  ibe  cliUigtDg  wliJlh  ot  tbe 
Tuoultr  "  bed," 

Befiire  vre  proceed  to  cunsider  any  ftirllier  dnnilH  lu  lo  ih"-  |iht>iii)TOi.*iw  iif 
the  Boir  tlirbUjih  the  veaieU,  we  aiuu  turu  iiiiulo  tu  fttutly  tliv  hi«rt. 

TlIK    HiLAKT. 

^  126.  'I'lie  heart  »  a  vitlvulnr  piiiii|>  which  works  on  inecbsiiiciil  ]trincU 
)>te:d.  bill  ihe  motive  (wwcr  of  which  is  supplied  by  tbe  contraetiuu  of  it* 
niuaouhir  6brci.  Its  Bt-lioii  conso<]uoiilly  presents  probleiuii  which  ate  piinly 
Riecbaiii<nl  and  partly  vital.  lie>;arded  lut  a  pump,  its  eflects  are  determiii«il 
by  Ihe  fre'iueiiry  ul'  the  beats,  by  tite  force  of  each  bent,  liy  the  vluiracUr  of 
oavh  beat — m  bether,  lor  ioatance.  slow  aiui  liiiiti-rinx.  <>r  Minldeii  and  Mhar|i — 
and  by  the  quantity  of  fluid  ejected  at  each  beat.  Ilen{«,  with  a  given 
frttqucuey,  force,  ana  character  uf  lieal.  and  a  given  quantity  i^bctMl  at  vach 
h<'tii,  the  pi-obleiiiB  which  have  to  be  deiili  tviih  uiv  for  the  miitit  inrt 
iticchaiiictil.  Tlie  viinl  prubleiuB  are  I'hictty  coiinecie<l  ivilh  tlic  c-humv  which 
(letcnuiiie  the  frci|ueucy,  fiirce,  nnd  cliaruut^r  of  the  bcMit.  The  qiinniity 
eivctml  III  wich  liuil  i*  govrrned  iiiore  by  the  iitnto  of  tins  r«l  of  the  Iwdy 
loan  hv  ihiit  of  the  heart  Ilnelf. 

The  Phnwmena  of  the  Normal  Beat 

The  vuibk  movenimts.  When  tbe  chest  of  n  iiianinml  is  opened  anil  arti* 
ficbil  reapimtiiiii  kept  up  tbe  heart  may  he  watetied  beatinff-  Owinjc  to  tb« 
ivinoval  of  the  ctiait-wall,  what  ia  aeeix  is  not  abwlulety  identind  with  what 
tak««  phtcc  within  tbe  intact  chest,  but  tlie  main  eventa  are  tlie  lamc  in  both 
ewes.  A  complete  beat  of  the  whole  heart  or  catdiac  cycle,  may  be  obwrv«d 
to  take  place  a»  t'ollnw^ : 

The  grvot  vetni>,  inferior  and  superior  renn  cavic,  and  pidmouary  reina 
are  seen,  while  full  of  blood,  to  contract  in  the  nuighburhood  of  the  bean ; 
the  contrnctioii  runs  in  a  peristaltic  wave  toward  tbe  auricles,  increasing  in 
inieiiHity  as  it  j^oes.  Arrived  st  the  auricles,  which  nre  then  full  of  blood, 
the  wave  suddenly  spreado,  at  a  nitc  totj  rapid  to  be  fairly  jud>,'ed  by  the  eye, 
over  tbe  whole  of  those  organs,  which  accordingly  contract  with  a  sudden 
(harp  fytitole.  In  the  systole,  the  walls  of  tbe  auricles  press  toward  the 
auriciilo-ventricular  orifices,  and  the  auricular  appendn^'cs  arc  drawn  inward, 
Wcuniiug  timallcr  and  paler.  I>urinK  the  auHoulitr  systole,  tlie  ventrioloi 
may  be  iteen  to  become  turgid.  Then  follows,  as  it  were  imrueUiately,  the 
the  v<'ntncuhir  «ystule,  during  which  the  ventricles  become  more  conical. 
Held  Wlwi-en  the  fingerii  tbey  are  felt  to  become  tense  and  hard.    A»  On 

Kitolc  progn«M>i,  the  aorta  aii<l  pulmonary  arteries  expand  and  elongnio, 
e  apex  u  tiltcid  tilighlly  upwanl,  and  llie  heart  Iwidta  Homewhal  on  ita  long 
azii,  moving  frnm  tne  \t(t  and  behind  toward  the  front  and  right  »o  that 
more  of  the  left,  ventricle  beoonie*  da^layetl.  Ait  the  MVNtolo  given  way  to 
Ibe  •uoceeding  ilitwtolc.  thp  vpntricl™  n-sunie  iJitir  firevniu!t  form  and  pOM- 
tion,  the  norla  and  pulmomiry  nrirry  shrink  aud  MlK>rli^n,  the  heart  tnmi 
back  toward  the  left,  and  thnu  the  cvcln  is  I'^iniplrifW. 

Ill  tbe  normal  l>cat,  the  two  venincleM  are  |H'rlci-lly  nvnobronout  in  action, 
they  contract  at  the  same  time  and  relax  at  ili"  :<nmc  lime,  and  the  two 
Uindee  are  similarly  synchronous  in  action.  It  has  Wm  maintttim-d,  how- 
•rer,  that  the  synchranism  may  at  times  tint  be  [lerlect. 

Beibre  we  atlempt  to  study  in  detail  the  several  [wirts  of  thia  complicated 
•orica  of  evenia.il  will  be  convenient  Intake  a  rapid  survey  of  what  is  taking 
plao«  within  the  heart  during  such  a  cycle. 


THK    IIKART. 


507 


I UT.  Thf  oirtiioe  rgtlf,  IVe  tany  lake  aa  ilie  end  of  ifa«  cycle  the  moment 
HvWb  the  vcolrkW  liitvint:  mptipil  th«ir  (.■onteois  have  relaxed  and 
nCnnriJ  (•>  tbc  diaslolic  or  rt^lin^'  [vi«jiiiiii  nnd  form.  At  ihiit  inoni^nt  the 
kbtd  k  flowing  frc«h-  with  n  fair  rapidity,  but  h«  we  have  aeeu  at  a  very  low 
pmtn,  ihrodgh  the  venv  l-svh-  into  (he  riKlit  auricle  <  we  inuy  I'uiitiiMi 
Mfflnt  at  firat  lo  (he  ri>,'ht  side),  am)  ^iiir«  ihtftv  a  now  ocithing  lo  kmp 
lt*liwiM|nd  valve  shut,  ^iii>e  uf  Ihis  bliiod  j)r<>biil>lv  KmU  ita  nay  into  itu) 
nnliM*  abo.  Thia  guea  on  for  aome  Hltle  lime,  aaJ  iheu  comt*  ihr  nharp, 
Awt  n«toI«  of  lh«  auricle,  whJeh,  since  U  heuiioii  ai>  wo  have  mmmi  iw>  a  wave 
if  cninctioD  ninniiit;  forwarxl  ulimg  ilic  emb  «r  the  row  cnvio,  driviw  Um) 
Uoij  net  baekwanl  iu(i>  iho  vciii.->  Imi  Kinvanl  iiidi  (he  vfiotriclti:  thifl  end 
b fclthar aeeurvd  by  thf  liivt  thai  (h«  ayttolv  bti*  bchiml  it  un  (hi-  veniiua 
MlJw  fmwurv  ul'  ihc  blixid  in  (be  rcin»,  incrtuuiiiit:  an  no  have  Eevo  back- 
Mnl Inward  tlie  cafiilliirU^,  aiid  before  i(  tbt^  ivlatively  empty  cavitv  of  lb« 
muide  in  wbich  the  ]>rw»iiire  ui  at  fintt  very  low.  By  the  eomplotc  oon- 
tflKtMO  of  the  auricular  wall*  (li<-  oi<mplclo  or  nearly  complete  emptying  of 
thttaTft*  i*  imturvd.  Nn  valvi-fl  an-  prtvcnt  io  the  mouth  of  the  eutterior 
*nacava,  for  (he^  arc  not  ntx-dtd ;  and  the  imperfect  Eustachian  valve  at 
ifenovtli  of  th*-  inferior  vena  cava  cannot  bo  of  any  gmt  use  in  the  adult, 
'i  in  its  BU'Tv  <lt-vclo|x<(l  mate  in  the  fo-tiis  it  hail  an  important  funeti'iD 
'  the  blood  of  the  inferior  vena  cava  thrmi^h  (lie  fommen  ovale 
;  anriclfk  Tbe  valvee  in  tbc  '-orouary  vein  ari-,  howercr,  probably 
'  DM  in  pT\-<rcn(int;  n  rertns  in(o  that  vessel. 
A*  llie  blooil  \a  being  driven  by  the  .-itiriciilar  systole  Into  the  rentiicle,  a 
irflut  current  ia  protmblv  tel  up,  by  which  the  blood,  passing  along  the 
I  of  the  ventricle,  |>elB  net  ween  iheiu  and  the  flap«  of  tbc  triiiiAjml  valve 
B  iMtda  to  flo»t  these  up,  IFigt.  t>9,  TO.j  It  is  further  probable  (hat  tbfi 
'  ntax  current,  continuing  komewhat  later  than  (be  niin  inii>  (ho  vvn- 
',  h  tufficient  (II  hrinz  the  flaiiH  into  ap|witiilion,  without  any  regurgitation 
inu  likC  snricle,  at  the  eroac  <>f  ihc  auricuUir  avfiole,  before  the  ventricular 


rnawi 


(riclr, 


[no-O*. 


7io.  70. 


PuiiatM  w  ViLTD  -ir  illl  (lutil.    AHk  Itiunh 


mute  haa  beyiiit.  According  to  wme  authoiv,  however,  the  cloeure  of  (he 
nln  m  vflected,  at  the  very  beg^nntne  of  (be  vcn(ricular  svHole,  bv  the 
Matrmctiua  of  the  papillary  mn«cle«;  the  churrUe  tcndiue»  of  a  papillary 

cU  are  attached  tu  the  adjnoiTni  edge*  of  two  Hajs.  »i>  that  (lie  shortening 

^  •  moacle  (end«  tu  bring  lh<M  edgoa  iolu  apposition. 


208 


TUK    VASCCLAR    M  ICCEt  ANiaU. 


The  mirit^iilnr  avHtolc  is  n"  we  Imre  Htii]  immcdiKtvly  folio' 
t]ie  ventricle.     Whether  th«  contrnclinti  of  the  vmtrii-ular  vniiie  (which  ks 
we  fhitll  a'«  ia  n  «iinnl«  though  prulungv.!  contraction  antl  not  a  tctunus) 
begin?  Kt  one  point  una  swiHtlr  tnivels  over  Ibo  rest  of  the  Hbres,  or  )>eeiiia 
alfovcr  the  ventricle  ut  unce,  ie  n  >(neeti()n  not  at  present  definitely  #eUled; 
but  ill  any  cose  the  wrnllB  exerl  on  the  contentM  it  preesure  which  in  aoon 
brought  to  bear  on  the  whole  conlcnte  uid  very  rapidly  rises  to  a  maxitouio. 
ITie  only  effeel  of  tliis  iiicrenaiug  iiilru-ventriculiir  pmcure  llpoD  the  vnlve 
ia  to  render  the  valve  more  and  ruore  tense,  and  in  consequence  more  tecure, 
llie  cbordot  tendiaie  (llie  slackeoinj;  of  which  through  the  change  of  form  of 
the  ventricle  is  pmbably  obviated  by  a  regulative  coiitraeiion  >if  the  impillar^ 
ntuscles)  at  the  eam«  time  preventing  the  valve  from  beinj^  inverted  or  cv«a 
bulging  largely  into  the  auricle,  and  indeed,  accur<ling  to  onuie  uhoerven, 
kiKiping  the  ralvular  aheet  actually  convex  to  the  ventricular  cavity,  br  I 
which  tuean»  ibi;  complete  emptying  of  the  ventricle  is  inore  fullr  eJlecWo.  < 
[Fipi.  tJO,  70-1  Thtt  connection,  to  which  we  have  juM  rderreil,  of  the  chordte  | 
of  tlie  Mimv  pnpillan*  inuxcle  with  the  ndjaoent  etjgee  of  two  tia\»,  ntiHi  iiMttU  i 
in  kvi;piu^  the  HiipK  in  more  complete  appiiiitiou.     Moreover  ihii  extreme 
bordcn^  of  the  vaiv<9,  oul*ide  ihc  attach  men  Li  of  the  chordiK,  are  oxomnvtly  1 
thin,  so  that  when  the  valve  i:<  closed,  ihete  thin  ;iiirti<iuii  an?  prcn>cd  flat 
together  bsek  to  buck  ;  bencc,  while  the  tougher  wnlral  piirl»  ol  the  vslve» 
bear  the  force  of  the  ventricular  tynUih,  the  iip|>ntcd    thin   memhranou* 
edge*.  pmMul  togvahcr  hy  the  blood,  niort-  cuiupletcly  Mccuru  the  cloewre  of 
the  orilice. 

At  the  cimi  men  cement  of  the  vontricular  syHlolo  the  semilnDar  vslves  of  i 
the  nulmonarv  artery  arc  ckifcil,  and  nnr  kept  elwcd  by  the  high  prcsnire  ot ' 
the  nlood  in  the  artery.     Ae,  however,  the  ventricle  continue*  to  pre»  with 
greater  and  greater  force  on  it«  contents,  making  the  ventricle  bard  ai>d 
teoBe  to  the  touch,  the  pressure  within  the  ventricle  becomes  greater  than 
that  in  the  pulmonary  artery  and  thin  greater  preeeure  forces  open  the  wmi- 
lunar  valves  and  allows  the  esca[>e  of  the  contents  into  the  artery.    The 
ventricular  arstole  nuiy  he  seen  and  felt  in  the  expiiseil  heart  to  he  of  wmie  | 
dnraliou  ;  it  i»  xtning  enough  and  long  enough  to  empty  the  ventricle  com* 
]>lelcly  ;  indeed,  n*  wc  ehslTsee,  it  pniliably  lusts  hinger  than  the  diseliargtti 
of  blood.  Ml  that  lliere  is  a  brief  period  <)uring  which  tlie  ventricle  is  riaptr: 
but  yet  contracted. 

I>iiring  the  ventricular  systole  the  .wmiliinar  valviw  are  prtascd  outwnni 
towan)  but  not  close  to  the  arterial  walln,  reflux  enrn'nl»  protmbly  keeping 
tbeiD  in  an  intermediate  position,  so  tbiiC  their  orifice  fornui  an  e<()iii lateral 
triangle  with  curved  sides ;  they  thus  offer  litlh-  ohi>tneIe  to  the  escape  uf 
blooa  from  the  cavity  of  the  ventricle.  The  ventricle  n»  we  have  seen  pro-, 
pels  the  blood  with  great  furce  and  rapidity  into  the  pulmonary  artery,  and! 
the  whole  contents  are  i^|>eeilily  t^oc1«d.  How,  when  a  force  which  is  driving 
a  fluid  with  great  rnpidiiy  along  ft  closed  channel  suddenly  ceases  to  act.  the, 
fluid,  by  its  momentum,  conlinuee  to  move  onward  aAer  the  force  has  ceased  ;: 
in  coDEequence  of  this  «  negative  pressure  makes  its  sppeanncc  in  the  rear: 
of  the  fluid,  uid.  sucking  the  fluid  back  again,  seU  up  a  reflux  current.  Sol 
when  the  last  portions  of  blood  leave  the  ventricle  a  negative  pressure  makes' 
its  apMArutce  behind  them,  and  leads  to  a  reflux  current  fnim  the  ar1«ry 
toward  the  ventricle.  This  alone  would  be  suflieient  to  bring  the  valreii 
Kweiber ;  and,  in  the  opinion  of  some,  is  tlie  real  cause  of  the  closure  of  tht, 
vdv4« ;  others,  however,  as  we  idiall  nee  later  on,  mainlniu  that  su1)se<p)eut  lo' 
tbi*  reflux  due  lo  mere  negative  preaaure  a  somewhat  later  reflux,  in  which 
the  elastic  reaction  of  the  arli-rmi  walU  in  cuiiri^rncd.  mure  cumplet<'ly  (ills 
and  rvndent  tense  llie  pocketx,  cauniug  their  free  margins  to  con>e  into  close 


^ 


THE    HRAHT. 


20B 


od  Irai  omUuit.  «oi)  thus  eoliv«ly  blocks  tlte  my.  Tim  corpora  Arnotii 
■■I  ii  iIm  etntn.  mkI  th«  tliiu  ineuibniiiouii  teabiona  or  luuulw  an  bn>ii)^t 
■Wtim  amavition.  As  in  tbe  tni^ua]>iil  valv(«.aa  here,  while  the  iiittHura 
4f  llvbhioa  ■  bont*  bj  ilie  tAu^bcr  bu'lies  of  i)ie  iwreral  vfth-M,  eii«h  two 
duD  idjMHii  luniilw,  prettied  to;^tber  br  tliv  bliiol  aL-iing  no  both  nidca  of 
lbaa.Bl*  kcM  in  ci>i»|ili!lf  cuiiloct,  n'tlbotil  nnr  Mraiii  being  put  ujioa  thuin ; 
iitUi  wftf  u*  orifice  ia  cbdol  iti  »  iiuutt  eflincni  itinDnt-r. 

nn»l«Baai4«|iwtef6and«tion  rorthcmw  put  hnrnt'l  by  BrQckv  Ibitt  durinc 
ilttHlrioiUf  (TKUile  the  flaps  are  prene<t  bjuk  ll*t  nxainst  tlir  arliTii!  witlt!>.  uiicf 
li  itt  ou«  of  tM  Kuri*  coinpl«teljr  cover  tip  lfa«  orifiMi*  of  the  corutiurj-  Hrirries, 
■  ikti  Uw  flow  «f  blood  from  tbc  aorta  ioto  ihe  ooronarf  arlerioa  can  ukc  plaL-e 
«lf  darinc  lb«  vanlricnlar  clia*lo)e  or  at  tfa*  "nrf  beginning  of  th«  ayatolv.  aoil 
Malal)<larlngihf  «7«tole  ila«lf. 

Tbt  vootriciiiar  ■r«to]«  now  ywM  olT.  tbe  mitMulKr  wnll«  reliix,  ibo 
taDUide  nrtitnu  to  it8  pnvioas  form  Ktid  positiun,  aiid  tiit?  cyd«  is  onoe 
anudwi 

What  tliui  Uiko  pUee  in  th«  rivht  tidti  tnkr»  ninety  in  the  teft  side  also, 
tWi  it  ihe  Hnic  Kiddon  »bnrp  uiriouUr  ayHtfilc  Wginnin^;  »t  the  roi>l«  of 
the  pilmuoary  vcin».  lb<'  kkhp  «y>Uile  of  tho  venlricli?.  but,  n«  n'e  ithni]  see, 
"M  murh  Hi'irc  |H>wiirfiil  wild  I'xvrting  niiurh  rioi'p  fi>rce ;  tho  mitral  Talv« 
w'tik  iu  iwu  fla^ig  n4-la  exactl;-  like  tlii!  trictispid  valve,  and  tbe  aotioD  of  the 
wilnnar  valvm  of  ibc  aorta  simply  rc|Mtata  that  of  the  v«jv«  of  the 
pafanaarjr  arter?. 

Wc  tmT  now  proceed  to  sludv  some  of  the  oardia«  eventa  in  deuil. 

fW.  IV  rJtaivfr  of  fartH.  'I'lie  exftct  detemiinulion  of  the  chan^  in 
Un  nd  poailioii  of  tbe  heart,  especially  of  the  veiitriclcs,  during  n  wdiao 
tjek  b  au«ud«()  with  difficullios- 

7W  vmtrielea.  f<>r  ini>lanov.  are  c'>ntinuallv  cbaoging  their  form  ;  they 
(faug*  wbik  llwir  cavitico  are  l>eiii)i  tilleil  I'rom  thu  auricles,  lliev  chan^ 
nVk  i1m  oiaifmctioD  of  their  wiilU  i-*  iMiinjc  up  the  prwaure  on  dicir  con. 
Kan,  Umj  ehaiw*  while  under  ihe  iiil1ii(-n<<e  of  that  pnwure  tbeJr  oont4«ta 
bitag  dbdiargM  imo  tbo  imeritv.  lunl  they  cbiui)^  wlico,  their  cBviliM 
hanig  bosn  enipti«d,  tbi-ir  mii«.-nliir  tnitl»  relax. 

.  Wa  may  tnk*-  it  f»r  icninteil  itiiU  the  intenml  ejivitics  are  oblitcraied  by 
tb(  qntou.  for  it  a  probable  Ibat  pmciir-iilly  tlte  nhotc  oonlcou  are  driven 
•01  tt  cacb  struko,  and  probulily  ido  each  citvity  is  emptied  from  ii»  apox 
maanl  iha  mouth  of  lb«  nrli^ry. 

VTitb  ragard  to  cbtiiijji-s  in  oxterniil  form,  there  sMou  do  doubt  that  the 
wle-ton'te  iliiuiMiter  is  much  leaseawd.  It  Mti-ms  also  clear  that  the  fro»l-to- 
kack  dtanteter  b  grciilrr  diiHttg  lh«  nhole  time  nl'  the  »y»tole  than  during 
thciiaKule,  the  incrcow  Lakin;;  |>Iii(M!  during  tlw  finl  part  of  tbe  sy»to1c.  u 
i%bl  lever  be  {ttaccl  on  (tit-  sorlnce  of  the  heart  of  a  mammal.  tl)L>  chesl 
hinsg  baao  opened  and  arlilicial  respiration  beinj;  kept  un,  some  such  curve 
« thu  raptCMnied  in  Fig.  7 1  is  obtained.  'Die  rise  of  tho  lever  in  dcMribing 
mA  a  curve  is  duo  to  the  elevation  of  iho  part  of  tbe  fr-int  turfac?  of  lli« 
heart  on  whicli  Ihe  lover  ia  resting,  ^^uch  an  clevnti'Xi  iui)<ht  be  caused, 
«ipMially  if  the  lever  avre  placed  near  the  apes,  by  Ihe  heiirl  being  "  tilted  " 
'  ntii  the  ayatule.  but  oiily  a  siimll  portion  at  most  of  ibe  rise  can 
.  Ill  tbia  cause :  the  rise  is  perhaps  best  aoen  when  tbe  lever  ia 
.  ui  lUc  middle  (loriiiii)  uf  the  ventricle,  and  inusl  be  chieHy  due  to  an 
I  ia  thr  fr'ini-li>-Uick  diumeler  of  tbe  ventricle  during  llie  heal,  Wu 
dwniaa  ihit  curve  later  on  iu  oonuevtiou  with  other  eurvee  and  may 
•|tly  aty  that  the  iiurt  uf  the  curve  IWtm  b'  to  </  probably  oorresmn^ 
lathe  actoai  ajntole  of  the  ventricle,  Ihal  ia  to  the  lioie  during  which  the 

II 


310 


THE   VASCtTLAR    UECHANISU. 


Gbr«a  of  ilie  ventrit^le  are  iiDd«rKoiu|t  contriictitm,  the  suilden  full  from  <£ 
(iiiH'iiH  r«]>reKDtiug  the  relaxntion  whii-li  i'onm  tlic  Orel  purt  of  lli«  <)i»>tale. 
If  (hU  iuterpretulion  of  ihe  curve  fie  eurreet,  it  U  ukviouii  llinL  the  froui'to- 
bitck  diameter  ia  K'^»'>r  duniifr  the  whule  of  the  nvslitle  ilmii  ti  1*  during , 
diuatole,  siiwe  tlie  lever  t.i  raueil  U]>  all  thin  time. 


nn.7L' 


THACIMH    nMI    IIUST  or  I'AV,  OUTjIIXKb    (V   rL.lt'U<i>  A   iJullT    LtlKn   UX    TUB    VCNTVIULI,  tH* 

Cnon  iuvi9(o  Bnn  nvciiMt.   Tar  Ivsisn-rciiLK  cuuve  hjhui  M  VmiuTiixai  r*a  Sannnv 

Tilis  increase  of  (he  froDC-to-bacIt  dinmeter  oonibinc<l  uith  a  decrease  of 
the  »i'k--to-eide  diameter  has  fur  u  rotult  a  chaoge  in  the  form  of  the  Mclioa 
of  the  bnso  of  the  ventricles.  I>uriiiK  the  diajitulc  thin  hiis  somewhat  ibe 
form  of  ail  ellipse  with  the  lon^;  axis  from  side  to  ude.  but  with  the  fr<><it 
part  of  the  ellipse  much  more  tunvex  ihaii  the  bock,  wnoe  the  back  siirfsc* 
of  tbe  veDtriclee  is  soiueMlmt  llatiencd.  DuriuK  ihosyMnle  Ibis  elli|M>e  is  by 
the  short«Diiig  of  the  siik-lo  aiile  diaint-ter  luji)  the  increiue  of  the  fniiiMo- 
back  diameter  cimverUil  iiilo  a  ti).'itrc:  much  mure  Dearly  ri'aeuibliiix  a  cirrJe. 
It  ii>  iir^tM),  moreover,  ihat  the  uhole  uf  the  bii-ii:  i>  const rii-lol.  and  that  lite 
greater  dficiency  "('the  iiurioiihi-vrutriridar  x'ulven  U  ihurtrliy  secured. 

An  Ut  the  bchaviur  of  the  long  diameler  frum  ban;  Ui  afiex  «bgH.-rv<:ri  arc 
not  acr(«d.  Some  maitilaiii  thai  it  in  Khurleiieil,  n:ut  tithere  that  it  u  prac- 
tically iinchaDgvil.  If  iiiiy  ■>hi'rlcnitig  dm*  lake  plarv,  it  iiiuttt  hv  largely 
conipennuted  by  the  clongatioii  of  tbe  gnmt  vvmcN,  which,  lu  iilalcd  above, 
may  be  MtMi  in  aii  iQ»|>ectioii  of  tbe  healing  hcnrt.  For  (here  i»  evidfocr 
that  the  apex,  though  ns  we  have  neon  it  i»  during  the  aysttdo  «omcwba( 
twisted  round  aiid  at  the  same  tiiDo  brought  closer  to  the  chMt-wall,  does 

I  "Rw  Tenia*)  oi  tnilua  ennai  llnH  (icxincrii  of  elrr In}  inlrudUMO  inio  ilili  niul  many  ulWr 
eUTTWUVOf  <u*  fat  tbe  burpotD-f  uiLiuurlDx  luiuor  Ihr  nnt\-r.  A  mii>|il<*U'  I'linu  iliuuld  eiblMI 
sn  "abvelMS"  Una.  TliU  hiht  Ut  iln^n  Ity  jiilnwitiii  ih^  U-vt^r^  nmuatfnl  t'tt  E.h<^  nivrliiivitl  bgl 
icmalntiWBl  mt.  toiurk  ullli  1k  |<:<1ii[  <m  ihv  monlliix  •urfaco  tti  Id  wison  :  n  atnttalil  line,  tlip 
■liiiiiwi  UEic,  I#  ibiu  4c«ct11jh1.  anil  nia)  betlmwn  tvSipear  aAcr  Oit^  oiirvu  tiHiir  H  inue.  aurl  nuj 
b*  pUcAd  BU-n  ur  tn*a>rKtily  brlrjw  Uicvunv.  Wluin  a  lunlnK-6>[lt  or  ulhi-r  llinv-iuaikDt  li>  luol 
tbvUni^nr  (tif  ij]-nk"tTijir^k.r  .-.r  n  i;nriln«^^i  in*-"!!;-!!  t>»<  c>nnw  if  iIjd  liiiilriK-'irk  will  «4vitf  m  40 
StaclWB  titiv.    Af:  liiu  bn-[i  iriro  <rilltiE  •iifftti?!.-  iliinilil  rt-  hrdiisht  t<*(\  imncli 

SfOAlUun  ihuT  i^j.  i<  luvc:  ix^m  <in<:  iTiIni  ■>f  ihv  ptiitv  ulik'b  It  liclHlrcd  bi 

aiuti  if  tlicluvv-.-  .  .  ijilv  mnrnl  n'  ■     iIl.  ,..i   r ..( rliu  1m tt  will  (l»<-rib«  •  wcnuail 

nf  ■  olrriv  lUir  ri^Mirr  til  itliijila  Itr*  mi  t^'  '<i  H^tffiuiii  •ifniM  Tiv  nudv  louf 

E«ioai[h  to  cm  luili  IIil-  ciitv*  rniil  ilic  >ii<  '  <it:  cimy  nr  nitici  Uni^iniirklni 

Ifakei  Wberv  UilaUiIruwii-    H}' itidvIi^  iTir^   '      '  ^  l[>I  iiTt<l  forfaiil  ^linlbit  vv^mmli 

oT  rlrclw  nujr  t»  liruwu  lti(T>u«li  iiiluT  .•  tin' liii»  <i.  0.  /  lu  Kie  ;i  won  Ibn) 

4nwu.    Tht  dittJ>n«  tM.<twrrii  inv  tv><  ''  vhu-  l»i  rjuiitunT)  uri  Uw  tunlrii^-lhTk 

0SI1C  or  DtbDr  Uiiiocurrc.  oroQ  lli«  nlivcb^i  -  n,.!  ,r    irio*  ni'tv  t>,-  ilmwia  oi>  lUn  inicliitf  ancf 

lumuuval  ttoiD  Ibu  ntunlliit;  liuimnuiut  in  liiu  loUouii^i:  *aj  i  TuKi'  i>  inirof  «>ii>[iaB«.  incliiu 
pdntt  «r  wlik'h  an  lixnl  iiui  m  far  ifian  M  Dii'  IitiuiIi  ■.•!  [)iu  li>vi*r  uvl  In  ihu  e>|«r4nirni. 
iMaNiPod  ttnnt  Ua  axil  tc>  lla  uruinf  i">JLii  l^i  iikrj^n-  •<<  \Ui-  ruEiiiiimMi^  eI^ipI  Uic  imviliinn  mi  tbv 
mttncof  ilicMnirvof  tin:  cln-lcnf  ubn-ii  r  itir  |>r>.'vi<iii-lF  ilniMti  <'i]rtnl  liniH  Umnt  a 

•KKiMiK-    Thniucli  it^  orati.iT  Omv  a  Jr  '  <  iTk-  hiivlkvA.    [Iy  Vorg^rte  imp  |kj4nt  nf  tbe 

eoDpaM  oil  I  111*  line  iiui  riii.iJnu  ii  niium  :  i -.  '  ■  iiiM  or  CKHnnI  a  •ci;iiiv<t(  '>(  a  ffrtl*  ina;i  b* 

ontwn  ■!>  K*  I'l  r<ii  piriv  |."ii'    'i  '  ii'    -nrrv  itu:  ;^;4lj  Imi  Jnlr>«l.  ikTiilnl«'i  ibi' nli«4<k>«4i  hfiponhM  oiiir 

kloe.    Siicli  aacciDijni  oj ii>  iir  luwl  for  Uie  tmmc  git^ri"^'*'^  "^  'l><^  nrt^liinl  \ttiv  atifl  may 

nnnibrror  nui^li  H^rnnr'i- "I'll  '•  'I'lmo 


TUB    IIKAKT. 


211 


bM  doD^  iti  [HMition  up  or  dowo — J. «.,  iu  tJie  lotifi  iixU  oi  tlto  body.  If 
iairabliii  or  iIi>k  u  needle  be  tbiuHt  tfanmicb  ibc  fhtHi-utill  m  Ibai  ita  iioiiit 
fliiDp*  i[il)>  ibe  n|>ex  of  tlie  heart,  ihouxb  tbo  uevdio  (piiviini,  itM  IkwI 
MW  neitber  up  our  down,  fts  il  would  do  if  iu  poiitl  in  tbu  apvx  moved 
d«*n  M  ti|i. 

Bnadly  ape«kiiig,  (ben,  dtiriuE  sj'sUtle  the  v<uilHcl*x>  uiidvnjn  n  dlmiDiilioQ 
tt  bul  vulufuD,  njiijil  Ut  ibe  voltime  uf  cxkiIviiIb  diM'bargvd  Into  Uh)  grvat 
imit{tor  tb'  wmllv  tlwnuvlvts,  like  nil  tiiU!«uUir  ittruclum,  niUiii  Uieir 
nliS*  dariaK  contractiuu,  **ve  for  i'linngni  wliicli  ninv  take  pliicc  in  the 
qoutitf  of  blood  cKintiiiDrd  iii  ibvir  bUH>ilv»M'!i>.  nr  of  lyni|>h  in  cbt.i  iiiler- 
■nmkr  t|wot«),  vrbilc  tiwy  iind«rgn  a  chunsc  nf  form  whiih  mov  be 
ilMrilMd  a»  that  from  a  ronghly  bemisphcricariigiira  wilh  un  irrcgularly 
tUlMiad  irction  t»  n  iiii>r>'  rvtruliir  com-  with  a  circular  biiw. 

fill.  I'-inUar  imi>ul*r.  If  (Ih-  haiiil  Id-  plitircd  oti  ih?  cbcat,  R  shock  or 
llfalM  will  be  fell  Ki  rncb  iM.'at.  mid  on  I'xnmiimiion  ihis  iiDpulse,  "  CArdiao 
bfviK"  <ii)l  be  limnd  l»  Ih<  >yiii-lironoii8  with  thi-  s)-«lolf  of  tbo  vontricle. 
In  mm,  the  cardiac  inip4iUp  niciy  \vt  must  dislinclty  fell  in  the  fillfa  cuetid 
intfipac*,  alMUt  an  inch  lioluw  und  a  tittle  to  tli«  meditiii  «ide  of  the  lell 
■fftfc  Id  an  animal  (he  wime  impulte  iiiny  also  be  felt  iu  ttnoUier  way — 
rit,  by  makiui;  nn  incision  throuch  (he  diuiilimgin  from  the  abduinen,  aod 
phnntC  (be  fin^vr  between  the  cheM-wall  and  the  apex.  It  ibeu  can  be  di»- 
(intllT  rccuentied  a»  the  retiull  of  (he  hardeiiin);  of  the  ventricle  during  the 
■iNiH.  Atid  the  impulse  which  is  feU  on  the  outside  i>f  the  cheM  it  chielly 
lM«Act  of  the  same  hardeuini^  uf  the  itatiunury  |>"r(iou  of  (he  vetitricio  In 
amaa  with  tlie  cb(«t  wall,  tmuimitted  thruuith  the  che«t-wull  to  (he  Rugvi, 
la  Mm  dacfid  elate,  during  dia!>lole,  the  apex  is  (iu  a  atmidin;;  )i<i»iti»n.  nl 
karti  ■(  (bin  )Hiiiil  iti  contact  with  the  cheit-wtti],  lyin^  Wini-en  it  and  the 
MhaUy  nviMaiit  (ttaphrazin.  During  the  »y>t<>lc,  wliilc  being  briiiight 
cMwr  to  the  chnt-aairby  (be  lihiug  of  iW  ventricle  and  by  the  move- 
Ifl  ihr  frrnit  iwd  to  the  right,  of  which  wc  hnvc  nlrcadv  tipoken.  it 
ly  gmwB  Iciiw  and  hanl.  The  vcntriclw.  in  executing  ificir  «yttale, 
l/i  cuntnict  agaiiiKt  n-«i«tnncc.  They  have  to  pru(lu«^  within  (heir 
anvm  pretMirrs  greater  than  those  in  the  noria  and  pulniuiiiiry  arteries, 
(■yoctifclr.  Thin  ii.  iit  fact,  tltc  object  of  the  •yctolf;  Hence,  during  the 
•idl  avtfote,  (be  ventricular  portion  of  the  hmrt  beoomca  suddenly  (eme, 
acamnat  id  Iheaame  way  hs  a  bladder  full  of  fluid  would  hcconie  (eose  and 
hwd  aban  fbrciblr  Mguee/^x).  The  sudden  pressure  eser(ed  by  (he  ventricle 
tW  twwiiata  suadenly  tense  and  hard,  aided  by  the  closer  coo(ac(  of  (be 

Ti  "tlh  tbe  ebea^waII  Iwhich,  however,  by  {(self  withou(  the  hardening 
tonuacliuu  wouUl  be  lOdutficieDt  to  produce  tbe  efl^t),  gives  au  itupuM 
ar  ihM-lt  Intb  to  the  cbcet-nall  ajid  to  the  diaphragm,  which  may  he  felt 
rmlily  both  uu  (he  cheat- wall,  and  also  through  the  diaifhragiu  when  tliv 
aUomni  i>  o|icued  and  the  tini^er  iuicrted.  If  the  miidilk-ation  of  (bo 
tfj^^uaiiti Bph  (of  w  hieb  au  nhull  s|)eak  in  dttaliug.  later  on,  with  the  i>uU«), 
ba  cardiograph.  \k  placed  on  (be  spot  where  tbe  impulse  it  felt  u>net 
'.  Um  \t\KT  t*  N-trn  to  be  raiwd  during  tlie  HVMute  of  Ibe  ventrtdt^, 
All  again  a.-<  the  syttule  |ia.-uie9  away,  very  much  aa  if  it  were  placed 
lh«  heart  dirvdly.  A  Inicing  may  thun  be  obtuiiM^l  laee  Fi^,  77),  uf 
ir«  aball  have  to  ^-ak  more  I'ully  immediately  (itee  ^  W.\\.  If  tbe 
of  the  lever  be  placed.  ni>t  un  (hv  exact  •«>(  of  (he  imimlse,  hut  ut  a 
iHancv  from  it,  (he  lever  will  be  >/epreue>' during  tbe  iyatole.  While 
*pnl  of  ini|iulH-  ilM'lf  the  roniact  of  the  ventricle  U  incraaacd  duriug 
,  away  fri'in  the  «(>»(  the  vi'niricle  rctirci  from  the  uhe«l-wull  (hy  th- 
ilJoD  of  ita  rigbl-to-leli  dinnicter),  and  hence,  by  the  mettinMiuul 
tttackainilt  of  (be  pericardium,  dmws  the  che*t-wall  alUr  it. 


»n  t- 


S13 


TnS    VA3CVI.AB    MKcnANISM 


S  130.  'Hie  *OHnd*  of  the  hmrt.  \Vli«n  the  ear  u  applied  La  llie  vIicbI. 
eiilior  cHrectly  or  hy  lueaiis  of  a,  Htetliwcope,  two  •ounds  are  Wari),  the  ftnt 
a  cttinfiuraiively  loiit;,  dull,  boomiug  snund.  ihe  second  a  short,  atiarp.  *uc)(l«a 
one.  Between  i\\v  liral  and  eecDud  ooundu  the  interval  of  l!nie  i«  wry  «liort — 
loo  vhort  ti>  be  uiensui-able— Itiit  between  the  fUMond  nud  the  nco«>'<lin^'  tint 
pound  there  i^;  a  dtstima  piiiise.  Tlic  ^uiidH  linv<-  lit.-«o  liknxsl  |«  tin*  pro- 
niinvifltioTi  nf  llie  sylUlilcs  lulili  d(l|i,  ah  thtit  the  inrdbr  cycle,  lu  far  a*  the 
«i>iind«  nn'.  ooncenit-il,  iiui^ht  Ih*  n-piisteDt^cl  by:  IQbh.  iViy,  piiiiov. 

Tiir  tffouil  mund.  whlc^h  U  cbiiri  niid  ithttrp,  prt^cnCii  iii>  didipulltts.  It  is 
oiinclilciil  ill  jiriini  of  liino  wiib  the  cli»iiiv  nf  (he  wmiliiQur  riilve*.  and  it 
h««nl  t<i  th(-  iKiit  lulvHiitn^t  uvi^r  ihu  a^ciiiid  righl  ooEal  carlilafru  cl<we  to  il« 
junction  with  ihe  ftcrniiRi — i.  r.,  at  tba  imiiit  where  the  imrtic  arch  niiii«C 
n(^»ri?«r  to  Ihr  ■iirra(«,  and  to  which  snimd*  ^nvrHt4.t)  at  th«  aoriic  orifice 
iTDuld  be  bent  cDndiiclvd.  Itii  oharuntcn  ar«  such  u  WDiitd  belong  to  a 
sound  genemtod  by  memhratie*  lik«  the  semilunar  vakte  bein>;  suddenly 
made  tense,  and  »o  thrown  ittl»  vibrations.  It  is  obscured  and  altered,  or 
replaced  by  "  a  murmur."  irhcii  the  semilunar  ralvcs  arc  allecled  by  diaeaw; 
and  may  ix  nrlilicinlly  obliterate!,  n  murmur  taking  its  place,  by  pasaing  a 
wire  down  thv  arteries  and  hoolcint;  up  the  auitic  valves.  There  cau  be  no 
doubt,  ill  fart,  that  the  second  sound  is  due  li>  the  semilunar  valves  being 
thrown  into  vibrations  at  their  sudden  closure.  The  sound  heard  at  the 
■econd  right  costal  caititage  is  chiefly  that  f^norated  by  the  aortic  valve*, 
and  murmurs  or  other  alterations  in  the  sound  cauited  by  chaii^is  in  the 
aortic  valves  are  beard  nioit  clearly  at  this  bjmH.  But  even  here  ihv  sound 
ia  nut  excluMvely  of  aoriic  ort).;iii,  ii>r  in  certain  cases  in  which  the  semibinar 
valvm  on  the  two  sidea  of  the  heart  are  not  wholly  syuchronuuii  in  aiuion  tbe 
»>iund  heard  here  i^  double  i "  twlu plicated  second  sound  "),  one  hdiig  due  to 
the  aorta,  and  miv  to  iht^  pulmonary  artery.  Wlien  lh«  sound  is  listened  to 
DD  the  lel\  «i<lc  of  the;  sternum  at  the  3>nme  Invel,  the  pulmonary  artcrr  is  sup- 
|ioecd  to  have  thccbiff  sharr  In  produciii);  what  is  hejird.and  changes  in  tbe 
Bound  beard  more  clearly  hem  than  on  the  right  side  are  talten  as  indicati  mm 
of  mischief  in  thu  milmomiry  valves. 

The  jir*l  Konnri.  longtT,  duller,  and  of  a  more  "  b'wming  "  character  than 
the  oecond,  hcartl  with  grenteKt  di'tinctneM  nt  lh«  s)>ot  where  the  cardiac 
impulse  is  felt,  nnwenix  many  diflicuhin'  in  the  way  of  a  complete  explana- 
tion. It  is  hcanl  diKtinctlr  when  the  ehi'^l-wallo  are  removed.  The  cardiac 
itnpulse,  therefore,  can  have  little  or  nothing  to  do  with  it.  In  piiint  of  lime 
It  19  coincident  with  the  >^ystole  nf  the  ventrioUv.  and  may  be  heard  to  the 
greatest  advantage  al  the  spot  of  the  cardiac  impulse — thai  ih  to  say,  at  tbe 
plac«  where  the  ventricles  come  nearest  to  the  snrlace,  and  to  which  si>uuds 
generate<l  in  the  ventricle  would  be  best  cnuduetHl, 

It  ii  more  closely  etjincidcnl  with  the  cloxuiv  and  eonseipient  vibrations  of 
the  auriculo'Ventriculiir  valves  than  with  the  entire  systole;  for,  on  the  one 
hand,  it  dies  away  beliirelbeseooud  sound  begins,  whereas,  as  we  shall  see,  the 
acttinl  st-stole  lasts  nit  to,  if  not  beyond,  the  etosure  of  the  semilunar  valvct; 
aihl.oniheotherhaiid,  the  Hurioulo-ventricular  valve  ceases  to  beteiucand  to 
vjbrnir  tm  soon  na  the  contonia  of  the  ventricle  are  driven  out.  Thin  aue^^tf 
that  the  sound  b  caused  by  the  sudden  tension  of  the  auriculo-renlncular 
valve*,  and  thi*  riew  U  !tup|M)rted  by  the  facts  that  the  sound  i»  obscured, 
altered,  or  n-plBir«<l  by  ninruiiim  when  tbe  trimiitpid  or  miira)  valre»  are  diB> 
eR(e<l,  and  (hat  the  r/iund  is  also  altered,  or,  according  tu  some  ot>M*rven, 
wholly  ilonc  away  wiih,  when  blood  i*  [wvenied  I'roiu  entering  the  vcn* 
tridee  by  ligature  of  the  vatiir  cava).  On  the  other  baml,  tlu;  sound  has  Dol 
thai  sharp  chamclcr  which  iiue  would  fxjiis:!  in  a  »)und  geiu'ratnl  br  tbe 
Ttbration  of  membranes  xiicli  us  the  valves  in  <iiicMiuo,  but  in  its  booming 


Tng    HEART. 


SIS 


I 


I 


<nMUiua  ratb«r  itti|ci;rau  a  luuflculHr  souimI.     Further,  acconliDK  to  some 

(mMrvrrv.  the  Buiitxl,  iboucb  ■i>iii«wbiit  motlifici).  mny  Blil)  l>o  hcanl  wheu 

ibe  Wkc  fcins  mn  (-btiti|KHl  an  tluil  lui  IiIchhI  <riiti-r>  itir  v«niric)i*.  iiml.  imlM'il, 

nor  b*!  rrcuciiiM^l  in  the  fi'w  bviil*  aivtm  by  n  iiiiiniiiiMlian  vcnlrii'lii  nipiily 

rut  <iut  nf  thf  living  IhmIv  1>r  an  loraiJoD  ciirrivl  W- 1  on' tin;  miri<-iil<>  ven- 

(rirular  rin^.     Hcni^  tU-  view  liiu  Itcon  ndoplctl  that  tlii*  lirvt  miiiMl  it  n 

ntnculRr  »i>uii<l.     Iti  (ljfcii8>iii^'  itif  ni(MCuUrw>itnd  »f  aki-l'-lnl  musclo  (wo 

illOX  Wtfwto  mi»i>n»  l»  •li'tniM  tlif  view  ihal  I  his  foiinH  nas  gwertWd  by 

Um  rvpoUcd  indivi'luitl  »iiiiiilp  coDtrnctioix  nhidi  mniif^  iii>  ihfl  tctaana,  Uiil 

Imbcb  cormpondm)  in  lotw  to  llie  nunilx'r  tit'  lltiiai.-  aimjiV  ra>t)tnctioii8  rt- 

pMitnl  io  A  woiind,  and  to  ndopt  the  view  thtii  ihv  s'tiind  nna  renlty  due  to  a 

n-fvlition  of  ui)i.-iti>i>l  IMMiong  oi'ciirniiK  in  n  muscle  iluriu^  llie  cuiitnujtion. 

Nu«.  ibcT«ntricular:^y»(ule  isuiidoubleilly  a»im|)lec<)ntra<.-tiuii.a  prolontp^] 

nmple  mntnu-liou,  wA  a  letanua.  mtd  therefore  uii<Ier  the  old  view  of  the 

Mtiiin-  nf  a  inTwcular  soiiiiil.  could  not  pnjiluce  such  a  sound ;  but.  acceptiug 

tktHihrr  vic-w.nnd  n^lleclint;  how  cixuplox  must  be  the  eouneof  theavHtolic 

mvf  iif  roll trai.-l ton  <iver  the  twiiied  fibres  of  the  ventricle,  w«  tball  nut  fiitd 

pnl  dirtit'ultv  in  impiMBiug  ibat  tliul  wave  iti  capable  lu  iu  pnignn  of  pro* 

^ariiii;  'ui-h  t(<)H.-tili<>iu>i{f  uni-'|uiil  tMisinns  lu  luighl  give  rw  to  ii"mii««ulitr 

wiimI."  and  ri>fi»cc|urnltj  in  n-j^inling  ihe  fint  toanti  iii>  mninly  •>)  cmutit. 

A<  -iich  n  vii-w  nf  Ibe  origin  of  the  nound,  w«  fhould  cxptM-'t  lo  find 

•■  if  ihc  niUMulnr  lihnf,  mid  w)  the  luitureof  tioiiml  d(![ieiidi'iit  on 

t!*'  .jjniiiuv  ■■r  Hirid  prrwnt  in  the  ventricular  nivilivf,  and  h<nce  nn)dilird 

bf  t>i,-alur«  >if  the  iiwiil  vrinj.  nnd  *till  more  hv  the  total  removnl  of  tlm 

auricir'  itifh  llip  niiriciilo-vrntricul.tr  vnlve*.     \\V  may  add  ihnl  y,v  »hi)iitd 

rijrri  111  f^nil  it  iiii'ititini  by  the  eecnjie  of  bhiod  IVdid  the  ventricle*  into  the 

anrriri  during;  the  syBtole  iiwlf.  Hnil  niit,'ht  rr^^rd  this  m  eiplaining  nhy  it 

ifaiaway  bc^n*  the  venini-le  ha.-,  eeutud  to  wiilfncl. 

MMTorn*. "i-i'iuK  thni  the  auriculo-venlrieiilar  valves  innU  be  thrown  into 
■Mm  irtuion  nl  the  oiufI  of  Ihe  venlricuhir  ^vitiole.  vrliJcb.  aa  we  have  aeon, 
it  ArttloMiJ  with  eoiisiderBhle  raimlily,  not  far  removed  at  all  event*  fti>ni 
At  npMitr  with  whicii  tfa«  teuiilunar  valreit  are  el<iiw<),  a  rapidliv.  ihertr- 
far,  npabV  of  giving  rive  to  ribraiiun>  of  the  valves  iideijunte  to  pmdure 
■  mand.  it  iadirtii-iilt  to  <«enpe  Ibe  condu^imi  that  the  eliiinirc  <if  thivv  ralve* 
■Ml  abo  irnenttr  a  tiiund.  whieli  in  ii  normally  be^tiug  heiirl  ix  mingled 
(a  MO*  «av  wilb  tb«  Mund  of  mtitcular  origin,  allliough  tbv  car  eannot 
dUKt  Ibe  muiure. 

If  we  accept  lhi>  view,  thai  ibe  Miund  Lu  of  itoiible  origin,  partly  "  miiBcu- 
Uf."  jMrtly  "  valvular."  I»>lh  eauiMrn  being  dependent  on  tbe  tension  of  the 
tnirteular  cavilic*.  wf  can  pt-rhaii*  more  euity  uiitlorstand  hon-  it  i«  that 
Ikr  wirninl  fint  round  is  nl  limes  to  larsriy,  indi-cd  w«  niay  say  so  com- 
(llttly,  altered  nnd  oWrured  in  disetifes  <>l  the  nuriculn-venlrieiilnr  valvea. 

^celhe  lett  vi-ntriele  foimf  (Ik-  entire  tell  apes  ofthelieiirl.  the  iiturmiin 
tctther  ehnBgesuf  tbe  lirst  si<und  heard  most  diftlinelly  at  I  tie  i<|>ot  of  cardiac 
ittpulw  belong  to  tbe  tiiilral  vnlve  of  itie  lel\  ventriele.  Monnunt  genemteil 
b  the  tricii^Did  vatve  of  the  riphi  ventiicle  tirv  beard  wore  dbtinctJy  In  th« 
wdiu  line  oelow  the  end  of  ibe  Kemuui. 


Kuiloenrtiiae  PrtMUre. 


* 


f  m.  Sinee  lh«  heart  oxbis  for  i1m>  pur|iaM  of  vxerling  presMire  on  the 
Utni  within  its  rat-ilie*.  hv  which  premurc  (be  eirenlntion  of  the  blood  is 
(it«t(d.  the  etudv  of  the  e^anicters  of  this  rndocardiae  pressure  poawsMa 
fital  intvtrsl.     t'nfonunately.  ihe  iibHTvalion  of  thia  pressure  la  stieoded 


314 


TIIK    VASCULAR    MK<'HANISM. 


witli  );TPat  r]ifl]ciilli«i.  The  ordinary  mercury  iiianr>iueltir  wliicli  m  on  user 
ill  studying  tlio  prcmiri?  in  tlic  iirlerica  fails  uit  wheu  applitN)  ui  ilie  lieart. 
It  ti  true  tliut  a  loit^*  canula,  or  lube  open  ai  (he  «Dfl,  lillad  vriili  sorliurn 
carbonate  solutiiii.  may  Iw  inirixiuccd  into  the  jujtular  vein  anil  wi  Kliniiefl 
dnno  iuto  eiiber  the  riglil  aurit-le  ur  ihe  ri]j|ii  venirii^le,  or  may  1h«  iiimilarly 
Intrniluoo']  into  Ibe  (.-aroiid  artm*  and  with  <-nrf  ulipjied  dowu  thnut){li  liii' 
oortn,  put  the  soniilunar  valves,  icii')  Iho  left  vt^ilnrle,  and  baviiig  been 
tbua  liilroduued  may,  like  the  ordinary  caoula  uned  in  studying  arU-nal 

1>reururc  ($  ll.O),  be  broiigbt  inui  c()iiueci)i>ii  with  a  niert-ury  mnnoinoteT. 
n  [biji  way,  nit  in  the  ca^  of  an  arlury,  a  prapbic  rtniord  may  uc  'ibtiiinvd  o( 
tbu  chnnjjcs  of  |irc«ure  lakiiijc  {)lace  in  thither  of  the  nb»vo  thret  cavitJM. 
But  tile  diniiges  in  llic  vcDlririilar  carici«<  are  m  grvat  aint  raptd,  that  the 
inertia  of  iht:  mrrcurv,  an  evil  in  tlw  cn»o  of  an  iirtery,  mmcs  w)  Iar),'*ly  into 
piny  that  ihc  curve  (l(Hcribvd  by  the  flout  on  tlio  mercury  is  far  from  beiag 
ail  accurate  n-cord  of  tbc  chaTigcit  of  prcsMire  in  llic  cavity. 

The  mcrt-iiry  nmiionwlcr  may.  htiwcvcr,  be  wade  to  yicfd  vnliialde  reeiill* 
by  ad  opt  in  (I  the  ingenious  conirivanc*  of  convening  the  ordinary  mnnomei«r 
iolo  u  niiixiruuin  or  a  minimum  inlrument. 

Tile  priiKi|>te  of  tbe  maxiniuu  mnnaineler,  F\g.  72,  uonitiiiO  in  (lie  inlroduetion 
into  ttii;  tulie  leading  fVoni  ibe  heart  to  tli<.>  mercury'  eoluntn,  <i(  n  (mudrficd  cap- 
aod'ball)  valve,  opening,  like  tlic  aortic  aeaiiliiiiar  valve«,  eu^ly  frani  tbe  hcan. 


rta.Ti 


Till!  MtituiH  Uxaeanna or  0*u>  mid  <".i i^ 

At '  ■  contwoUMi  U  auili;  sriih  Ihcliil*  iMdlni  lo  tbe  hMrC  Wbrn  the  •pn;v<UBp  t  Ic  eioavd, 
Ibt  mlTB  r  (•mil*  liibi  nrlluii,  *n(l  llio  luilrumcnl.  ID  llio  poililon  of  Ui*  rain  ilwun  la  tb*  l^nk 
l>  a  iMxlmiim  nutnoniitUf,  lly  rvivnliiii  iIhi  illnicilloii  of  t  li  !•  niii>«n«(1  Inlii  a  nlnlmum  nuu»- 
Omrtn.  Wliirn  t  Imptnad,  llic  (arlHUims  uf  |<r«Mun  ■»  miiitcJw)  Blong  a.  nod  Uie  UMmpRil  Uioi 
Mtt  llfc*  an  •mil  iiui]  iiuuiOQiDler. 

bat  cloMDg  firmly  nhen  iliiid  atlttmptc  t»  return  to  the  heart.  Tbe  liighmt  pres- 
Hire  it  that  which  dritra  Ihe  lungect  column  of  fluid  Tiwtt  the  voire,  raining  the 
mercury  ouluma  lo  a  currtHpoiiding  height.  Since  thii  culumn,  oan?  pa.it  the 
valve,  cannot  return,  the  mercury  reinaiDs  at  the  height  lo  whiuh  It  niu  raised 
hy  it  anil  tbu>  iccotd-  the  Biaximum  preanurc  By  r«ver«ing  the  direction  of  the 
lairo,  tile  manometer  i*  convert<<d  from  a  maximum  into  a  minimum  instrumeiit. 

TTw  mnximum  manometer  applied  to  the  cavity  of  either  ventricle  or  of 
tbe  right  auricle,  gives  a  rcoorJ  of  the  highest  pressure  reached  within  thiit 


TH-E    IIKART.  S15 

nrliT,  ami  thr  niinitiium  mauoincler  aiinilnrly  iliowtt  the  hiweu  prvwure 
utrifi,  (liiriDb'  il>c  lime  tltiii  lbs  iiuttrtiiuetil  in  np(ilieil. 

TWni««tntuiii  iTi&ii»met<>r  itiusemployMJ  tliow.-rtlint  the  maxitnum  jiroi- 
HTMO  llic  Uti  vciilriclr  t>  (Iminctir  (^reurcr  thuu  Itie  mcsii  urewiuK  in  the 
MUfllifi  ortlitiBry  ntPriniry  niMKHDcicr  ImviD);  previiiunly  giveu  lti«  [hita- 
dunl  rpMili.  due  In  tlx'  ittenia  or  Ihf  iiH>n-ury,  l!int  U)C  iii«nn  jin^Muro  ta 
ibt  IrA  vtintrkl^  iiiit,'lit  \tf  li-w  iIirii  in  lli<-  iionn  ^  thut  llir  nnixiinimi  jiro- 
■itin  Um  Hfcht  TOiilrii-l<-  ii  Ir^t  ihiiii  in  lh<'  left,  iiii'l  ill  lliu  right  nurivlc  b 
4111  Imil  la  Uivdofc.  lor  «'xiuii|>lc,  the  iiri-Miirp  in  ihr  left  vciiiridi*  nwcbM 
luiimum  nrnlxiiil  140  iiiiii.  :  iiii'riiiryi,  in  ihv  right  vciilricio  of  about  60 
Mi.uul  in  iIh'  rii^ht  aiirii'h-  ol'iilimit  'i^O  mm. 

Hal  lb*  chief  inimMt  ntlnchi^  in  the  miiiiiniim  (irvH^iirr  oWrvnl ;  fur  ihfl 
oiiiMiiu  ttwiKHnotfr  nv>r>l^  ii  uryliif  prcmiirc?  in  (he  cAvilieaul'the  hnut— 
iL t. ibmw  tbst  tbe  prwMirt-  in  ihi-m  mny  fail  bclxn  thtit  of  ihc  iitmmpherc. 
Tbnio  lb*  IcA  WDtrklp  (iif  thi-  d<%'i  n  minimum  |irt»<ure  v.iTviii};  from  — 
Ut*  — 20  IBID.  ttMy  hv  rcncbiil,  tin-  minimum  of  thv  ri|;hl  ventricle  being 
lh«B  — 17  to  — 16  nim„  iihi)  uf  Ihe  righl  niirii-Ie  from  —  12  to  —  IT  mm? 
hitof  this  dimiDUtion  of  prCMiire  in  the  ctirdiav  cat-itiee  luuy  be  due,  as 
•ill  b*  I'Xplnined  in  «  Inter  part  of  tliie  trurk.  \'i  the  iui>iratiou  of  lh«  (borax 
ii  ite  ft«pir«l<>ry  movenM-nt*.  Bill  even  wlieii  Ui«  tlionix  i»  opened,  and 
Biiicnl  mpintitw  kept  up.  uniter  which  circuinslaDcn  do  such  mpirati'm 
ubi  plu«,  a  ncftalive  pn'&Hire  i^  «till  uhwrved,  the  ptvasure  in  the  left  veii- 
trirlr  Jllll  tinkiiiK  o^  l<"^'  *^  — '^^  t^'Ri-  Now,  what  ibe  instrument  uctuallv 
ik^iis  thai  at  ituoie  lime  or  other  during  tlie  number  uf  bentM  which  took 
pbf*  while  tbe  instrument  wu  applied  i  and  thes«  mar  lutw  been  very  few) 
Ihf  fMMUR  In  tbe  ventricle  lonk  »o  many  mm  Ih-Iow  thatof  tbeatmoflphere 
nhi*  mTTBlivf  |>irM>iin.-  is  olimrved  when  the  heart  iti  Wating  nuiti-  regu- 
,nc\t  U-nt  Wing  exactiv  like  iho  wlhrre,  we  may  infer  that  a  nt.-gativ« 
Of*  im-un  at  s»nn-  p<!ri<Hl  or  lahcr  of  ench  canliiu'  i-vflo.  Itut  tho 
roiiK-ni  ■ibvlinii'ly  givcd  ii*  no  inl'orminion  w  to  the  exact  phaec  of  the 
hwiB  iihirh  the  ncg"tive  pnwiiri'  iM-curv;  to  thu  point  Its  wvll  M  to  tho 
iaaurtnnrr  of  (hi>  iii-gntiTe  jircsurr  "c  jhtill  return  pnwently, 

\\M  The  diHiruIlir*  duo  to  tlic  iiicriia  of  the  mercury  may  he  obviated 
kf  (ilcipting  the  nx'lhixj  of  Chauveiiii  iinil  Marvy  which  cuii*i<t«  in  inti*i>- 
Htiif  in  ■  largo  aniittiil  iucb  as  a  horce,  through  a  bloodvcaeel  into  a  cavity 
Wlhr  hnirl,  a  tulw  ending  in  nn  olu#lie  bag  i  t'ig.  7-t,  A )  fashioned  »i>inclhing 
Kk(  •  wmimI,  both  tulw  and  )>ag  Ixting  tilled  nith  air,  and  the  tube  being 
naotcMd  wiih  a  recording  "inmbuiir." 

A  taW of  appropriate  corvniurr.  A.  A,  Fig.  73.  la  ftimioheil  at  ita  and  with  on 
*laiti«ba]C  or  ''ani^utla"  -i.  Whi-n  it  ii  ili-nirrd  to  cxplurc  nimultaneoualy  Uotli 
diritl*  and  veninele,  the  mund  i-  I'liniinhed  vith  two  ninpulla-  with  tiro  amall 
•tMlr  l>*g*>  on«  at  the  extreme  end  and  the  other  at  such  a  diatance  that  when 
tbf  fannvr  u  within  thr  cavity  of  the  ventricle  tbe  latter  i«  in  the  cavity  of  the 
•■kir,  Huefa  an  iaatraiDOOt  iaijiokenof  ann  ''cardiac  souad."  Knrh  "aiupolla" 
mnicam  by  a  aeporate  air-tiglu  tulw  with  an  air-tight  tambour  (V'\g  '-i,  U) 
'»cb  a  levrr  rml*.  mi  thai  aiijr  iiri-^ure  on  the  aiiipulla  b  cuiuinuiiical«(l  to 
irity  of  ilH  re>t|H<rtiTe  tiiinbiiur,  the  lever  of  which  is  raiwd  in  jfojiortloR. 
two  anpullB>  are  iiaeit  thr  writin);  |»'iniit  of  biith  leven  arc  brought  to  bnr 
I  tmmt  fvconling  furfaee  pxiictly  niidrracstli  each  irther.  The  tobe  U  core- 
'iMroHarei)  through  the  right  j'l^iilar  veta  into  the  rijchi  side  nt  the  heart 
lb*  hrviT  t  ventricular  I  ani|>iilla  lo  (iiitly  \n  the  cavity  ol'  the  litcht  ventriola, 
I tcawrijarntly  the  UJ>i>«r  (nurivulnr)  ani|>ul1a  in  the  cavity  oflhc  riirht  aurici*. 
(loanraihl  prvTi-ureon  Mtlicr  aiu|iullri  Ibrn  cauw  iniweiniMili'nriliv  eurm|H>i>diaf[ 
When  tlir  preaMre,  fur  instaoce,  on  the  aiupulla  ia  the  aurkle  in  iDcroaaeJ, 

'  n^  kanikan  am  In  t*  nail  tuvt  mnvlf  a>  Innaari  i  irhich  kin  tn^  olBcnvd.  aad  OM  ai 
Hp>4««n  Itrm  ■  tus«  ai^ln  of  n**a 


St4 


THB    VASCUJjAR    M  Ei.'[I ANISM. 


With  grwii  (liffimltioB,  The  onlmary  m«rcury  muiionieter  which  \a  m  tiBemT 
in  ituih'ing  tlu-  pn^^iine  iu  the  artvrie*  failH  us  wbcu  npjiHoil  in  iho  heart. 
It  i«  tnir  ihsl  II  long  cuiiiila.  or  lube  open  iit  the  eiiil,  filkd  with  fto^lium 
citrWiintn  :i'>hili<in,  may  bi:  iiurniliicuil  iutu  the  ju)culnr  vein  hdiI  ita  vlifiped 
(l>>vrn  iiil'>  i^lliT  i\\v  right  nnricle  or  the  rl^ht  vtmtHt'lc,  or  may  be  i>iiailiirij 
iuir^xbiccul  tnli)  the  rnmtii]  tirt«ry  lun)  vtiln  I'ltn*  iilipTieil  Hnti'ti  tlirnugh  th« 
sortn,  piwt  the  scniiltiniir  vnlvM,  into  the  \ett  vcntru'lo,  ami  linviag  httn 
thtXi  intro<)i]CiC<)  mny,  like  llie  unlinnry  miiiiln  iiwrl  in  ■lintying  nrlcruil 
pmaon  ($  lI-'>),  be  brought  into  (wnnt'ctinn  with  ■  roemirv  minKimcter. 
In  this  wity,  nf  in  tlio  caw;  of  nn  itrtcry,  ii  ^riipbir  n^cord  niny  be  obtninetl  of 
the  changes  of  premure  taking  pUiM  in  cither  nf  tlic  nbor<i  tbr«e  cavitiM. 
Dili  the  chtiiige»  in  the  ventricn]:ir  caviliiM  nrc  to  gnwl  nnd  rapid,  thnt  the 
inertia  of  the  mercurr,  nn  evil  in  the  ctuc  of  nn  artory,  cnniM  m  largn^ly  into 
play  that  the  curv«  describod  by  the  float  ou  the  mercury  is  far  fruni  being 
nu  accurate  reoord  of  the  changes  of  promire  in  the  cavity. 

The  mcrciirr  mnnoinel^T  niay,  howerer,  be  made  to  yield  vabiable  mulls 
by  sdoptiiii;  the  iiigonioUB  contrivance  of  converting  the  oritinary  inauometer 
into  a  manioiuio  or  a  minimiiin  iDtriimeat. 

The  principle  of  the  maxiniuin  tnniKimvler,  t'ig.  7:2.  conamts  in  Lbe  introdiietioa 
into  the  tulip  ImdinK  fnim  tlie  heart  to  the  imrrcury  column,  uf  a  (mwlilieil  cnjr- 
anil-bnll)  valve,  openlug.  like  the  aortic  Miniluuur  vatvea.  easily  from  the  h«an, 

no.  Ii 


TiiK  HiiiKiH  UutoHsm  or  OvLis  «)n>  oivix 

At »  •  oaMiecQon  l>  awlu  Miili  tlie  lulio  laullnclQ  Ibehoin.  Wlicn  the  lercixlapiii  *  l«  Clowfl. 
IktnlrofoiiMliitaBrtloii.anillliD  limlruiiiviil,  Iii  iliv  innlUuu  of  lliu  nlr*  tltaan  la  ItW  SfUl^ 
It  •  iiniin«uni  muunneUr,  Ur  nnnliis  ilii-  dircciloii  of  i'  u  l>  convcrici)  iMu  ■  rnlalmwin  nuuk- 
DiBiAor.  Wlu-ii  tlio^wsad,  Ibe  vulnUuui  ur  iircatiirc  aru  copiDfvd  almif  u.  sad  Uic  ttuUanunt  Uwn 
Mb  Ilk*  nn  ontlEiMT  aananKMr. 

but  cloalng  flriair  wlien  fluid  atlcnpt*  to  return  tn  tlio  hearL  The  liighott  praa- 
•ure  is  tliai  whicli  drive*  the  longeat  column  of  Ruii!  {>iuit  the  vaWc,  raiting  tha 
mercury  L'olumn  to  a  corrMponiling  height.  Since  ibu  column,  oncv  pa«(  thB 
valve,  cnnimt  return,  the  mercury  remalas  at  the  heiglii  to  which  It  win  raised 
liy  it  ant)  iUuh  reconin  llie  iimviiiiuin  prMxure,  lly  reversing  the  direccitin  of  the 
valve,  the  munoineter  ia  converted  from  a  maximum  into  a  minimum  iiittiuaienU 

The  iDBiciinum  manamelvr  applied  to  the  cavity  of  cither  vcDlriele  or  of 
ibe  right  auricle,  gives  a  record  of  iho  higbi^<t  pKuiire  renchod  within  thni 


T1!K    HEART. 


215 


artr,  uxl  th<>  tniiiiiiiuiii  itiAiioincipr  iiiinilnrly  >li'>«r8  tb«  lowMt  |)r*mira 
imHwI,  durinj;  iltc  tiiii«  tKiit  ili«  iti*tritn>cnl  W  opplitvi. 

Thr  mkiiriiuiii  maiioiRftiT  iIiih  mi)|»I«v«<I  dinwrthat  ihv  mitximttni  ]>rM- 
■I*  lu  the  toA  v4-nirii'l«  »  >lt»iincllj  grcnlcr  Ihno  Iho  menn  prcmure  in  tht 
■■rtiilbr  onltnan'  mvreury  iiiniuk racier  Iinvinc  previously  giveii  ihe  |iuni- 
iniai  malt,  due  to  iIm-  inonia  uf  lh«  nier<-ury,  that  the  mcnn  prcesurc  in 
(blifl  mitmte  nii^'lil  Ix-  leiii'  ilmn  in  lli<>  uorta'.  thnt  ihe  niniiimim  proft- 
Mnin  Ihv  ri^l)t  retilrirle  b  tfiSB  tfawi  in  iW  l«ft.  iiod  in  ihe  H^ht  auricle  is 
Mill  Urn.  In  (tie  dot;,  fur  exiiiDpl«,  the  pressure  in  ttie  left  \-eiilriele  reiichoa 
latiimiiin  'ifatratit  1-10  mm.  I  nicreury),  in  the  rij^lit  Teiitricie  of  nbout  60 
M^  Aiid  Id  iIw  Tight  niirit'le  of  nbout  'i<)  mtn. 

Dm  the  rfaief  inlervKi  Htlncltfe  to  llie  niiiiiiiiiiiii  prwaiire  uWrved  ;  for  lh« 
afainsn  nanonieter  nsH>rtl'  u  ne^iliit  presgitre  in  the  eavilieanftiie  liean— 
i(L.«bm>  lliAt  ihe  pre*«iir«  in  l\wm  may  fall  beluu  ijjitt  uf  tli«  atmiupli«re. 
Tbiln  Uie  left  ventrifle  (of  iIm*  ci-ifii  n  oiiuiiiiiitn  |iivsHurc  varyiiijr  from  — 
VlU — 20  IDID.  (UHT  be  reuelivit,  l)i«  iiiiiiiiitiim  of  th<^  ri|;lit  v«D(riel«  beinjr 
fioa  — 17  lo  — 16  mm..  ainl  uf  ilw  HkIiI  auHi-le  from  —  12  m  —  1"  mm. 
E^nof  Ibi*  ilimiDUtion  nf  ]ir«Biir«  in  the  ciinline  i^vitin  may  he  iluc,  a* 
■til  W  npliUDetl  iD  a  ialer  parioniiiu  worlc.t^  the  ttamralioti  (ij'th«  thomx 
ii  lla  lOfiiratory  nxivinteni*.  Bin  uvea  when  iht'  thorax  i*  upeiieil,  itiid 
arliftfial  n>pinil>o<i  kv|K  up.  under  whieli  cin-iiini'runi««  no  i>iieh  anpiration 
tabi  place,  a  n«^tiv*-  pivwurv  i>  riill  •iImitv<'<I,  the  pri'miirc  in  the  lefl  vcn- 
iriflr«lill  linking  n»  Ion  m»  — 'li  mm,  Now,  whiil  the  in»tritmrnt  actiiiillv 
abuii  i*  that  at  i>om<-  linn-  or  other  Htiriuji  tlio  nnnibiT  nf  beittx  whii'h  took 
plat*  vliila  thv  iiutrunirnl  wan  npplir<l  i  iind  ihive  ninr  haw  bc«n  very  lew) 
ihifniiw  in  the  v«nlrid<t!uiMkf>o  mnnr  mm  In-low  ihiil  of  tb<^  atmnfphvrv 
9btn:  tbi-  ncftnlive  tirmxtiri'  in  iilui<rvi-d  when  the  heart  a  ln-ntinj;  <|iiile  re^u. 
Itflt,  i-arh  iM-ut  being  exnelly  like  tlie  i>lher«.  we  miiy  infer  thnt  a  ne|;Dlive 
«tv  iMxiirf  at  Kidie  period  or  olber  of  eaeh  eardiac  cycle.  Itut  tlw 
DSiTDt  obviously  f,'ivefi  u*  nn  information  as  to  the  exact  phiLse  of  ihfl 

til  whkh  the  oeKalive  pre»ure  ncenr»i  (o  ihia  pojol  as  well  as  (n  the 
on  if  ihis  ne^rative  preaaure  we  bHaII  returD  prvaeotly. 

I  US.  the  dilficiilliefi  due  to  the  inertia  uf  ihe  oKrcurr  may  bo  obviated 
by  iiloptlax  the  mcthitd  of  Cliuiiveiiu  lujil  Marer  wliit-h  conttiiU  in  iutro- 
Mrip^  in  a  iarye  animal  such  as  a  horse.  tbrou([h  a  bloodresMl  into  a  cavity 
«ftbe  benrl,  a  tube  ending  in  an  ehutii-  Imik  '  ^ig-  78,  A>  fashioncit  something 
likt  a  miiixl,  tioih  iul>e  and  liaj;  beiny  filled  with  air,  imd  the  tuln;  being 
mmtcu^  «ilh  a  recordinif  "lumWur." 

)  labe  of  siifiropriHle  curvature,  A.  ft,  Pip.  T^,  is  lbrn!«Iied  at  its  end  with  an 
klisj;  !•!  '■aBipiilln'-r,  Wlifn  it  i«  il.*ir(.I  lo  explore  simultaneously  botli 
it  aitil  Tvfiirlrli',  (lii>  Hiund  i*  riiiiii>hi-il  with  two  ninpu11«>  with  two  small 
*(aulc  iMfi*.  one  at  the  extreme  cnil  Hiiil  the  other  SI  inch  a  ilblancr  tliat  when 
ibc  f'TTRpr  ta  within  Ihe  i-Mviiy  of  the  ventrii-le  the  latter  is  in  the  cavity  of  the 
Mr-  I  IB  iaitriiuient  iii*iinkenora«a  "csr<lia<:  sound.''    Each  "ampulla" 

(DC.  by  a  MjianiU'  iiir  lijilit  tulie  vith  an  air-tiKht  tamUiur  (Fijc  7-E,  D) 

•«  •Uifli  a  Ii'K-r  r<Bts,  vi  ihul  uny  ptnaure  on  the  ampulla  ii  oJtumuaii.'itli'il  lo 
(br  (arhy  nf  its  resiiective  la'ulH>nr,  the  lever  of  irhli-'h  ii  raittd  in  profiortion. 
I  iwp  aoipullie  are  usi-il  ttit-  writing  points  of  botb  levers  sre  brought  to  bear 
Fsamr  reeurdinjt  >urli*i'i'  rinctly  underneath  cacli  other.  The  tube  t*  nre- 
'{fliraduatol  ihroueh  the  ri|{hl  jiiRutsr  vein  Into  the  riitht  siilc  of  tbr  heart 
IllMkrwer  {ventiicularl  an)]Millii  is  (nirly  hi  the  Cavity  of  the  richi  renlrU-ts^ 
iMSMnawtl^  the  upfier  tauricuhkrl  ampulla  in  the  cavity  of  the  riclit  suriclv. 
■BBtof  piv«uroon  either  ampulla  then  caiiMt  inovemeots  of  the  c«rrr«pi>ii'lina 
WbMi  the  prcwure.  Tor  inslsace.  uniboiunpullainUioaorickiit  incmumT 

*tb—  WMattwamobs  nxMlitrnrt  nmlv  >•  lawaiMai  aUoh  Imv*  )■«■  utrvsJ.  and  bMh 
<—Wihwwa  a—  a  toiye  nusUw  al  ■— 


i 


216 


THE    VASCLTLAR    MKfHASISM. 


tfa«  Hiiricolar  l«vtr  i*  rniif  il  and  drocribpa  on  Ui«  r«corcliii|{  nirikec  u  ■«ern<linK 
CDivr:  Klirn  Ilic  |iirsiiiirc  ii  liik«n  ofl'  Ihe  curve  tl«»cen<la;  and  to  alio  ir lib  die 
T*  lit  rifle. 

The  "iKiiind''  miiy  In  n  iiimilnr   munnvr  he  rpiiHUr  iitlmilurei]  ihrougti  ihp 
carotid  nrivn-  itilo  tliv  /^  vfntririr  and  the  cbunKn  ukiiig  pinve  in  ihui  chnml; 
a1«>  ciplotrd. 


A' 


Hr, 


rf 


A 

MiMT**  TAaaiii'K  «'iTii  Cakdi*c  Mi'miv 

A-  A  >Liniile  isTtllAP  totiurl  viicli  lu  Enaf  be  lihd  Ibr  cxplormUoti  ut  llw  Itft  nfU'iclo.  Itw  iort3£m 
•  olltii'  iiuii'illn  >1  llii>  villi  i*  t>(  III!  11  liiiI!ii'itiM>cr,  ttn>ti'l)vil  uiut  aii  ii|i*ii  fnniwuiirk  iitlli  imrlnUle 
nppiflti  gljuTciinit  bt'luiv.  ITii:  long  iu1«  ^  wrvn  lo  [iitnxliici' 11  Into  ihu  cavllf  Btilcli  It  liitBlnd 
loci|>l'in 

R  Tilt  utnlwiii.  I'lio  cnrUl  cliainlii'r  m  In  <nrigiv<l  111  mi  nli-tlghl  iiiBiiiicr  irilh  Ihr  IndU-mM** 
c,  bcarLiijE  &  ihlii  Qicliil  pUle  n'lu  vlilcli  h  atlvh^  Hit  Itvcr  I  iiio%inie  *>"  the  bliict  A,  Tbe  itlHikB 
UuiUiiir  iMii  W  iiliicol  liy  incmiiof  Ihc  i.-l*iii|ifViil*ii)'  lieidOliiu  Itiu  iii'ilglil  r.  Tlin  lii'Ua-nililivt 
liibr  rxtvn  lociiiiiivot  Ihr  Inii.'rl'itortliounit'iiirvltiipr  n1(b  ihoarltyornivuminillii  uf.t  or  mil  h 
Mnr  olhoi  CBVlir.  Siipiitnliii!  liini  ilio  tube  (  vttn  connci'lril  *  lUi  b.  kiiy  jiremun;  «■»(■«•!  on  ^  wuuld 
CMi«  Itw  >u4(«f  tbo  Umlnurlu  rite  anil  Uia  point  af  lti«  Ivvvr  woulil  b»  jirnjiutllciiiiild}'  mliwl. 

WIk'ii  lliLi  inHtniRK'nl  ia  iipplir-'I  (o  tliv  right  ntiriclo  iin<t  vrntriclr'  Knn« 
ituch  rvcori)  t*  uliiaiiic^l  nil  ihiit  i^liown  iii  Fig,  7 1,  whrrc  the  ui)p«r  curve  i»  t 
trnciiig  Itikrn  I'nim  ihc  right  iiiiriclc  Bin!  the  Inwrr  ciirvo  from  the  right 
vciilriclc  of  Iho  hi,ir»«.'.  Iwih  curve*  liiJHg  tJiki'ii  simultaneously  on  the  smne 
n;cnriJingfiirface. 

In  ihno  curvu  lliv  tisc^  uf  tho  lever  indicatefl  prcwure  exerlcd  upoD  the 
corrciwiiding  aniiniUii.  niid  the  upper  curvo  from  the  right  niiriclo  shon-s 
tbp  sudden  bripf  |>rcs<iir<'  ib)  pxcrlcd  by  the  ■uddcn  and  brief  auricular 
syetole.  The  lower  curve  froin  the  righl  ventricle  ^howit  ihnt  the  preanire 
exerted  by  Ihe  veutriciilar  sVfilule  beginii  nituoat  immedistely  after  the  auricu- 
lar BVfllole.  increflBee  very  rapidly  indeed,  so  that  the  lever  risee  in  alniixt  • 
elraight  line  up  lu  c,  is  coiiliuued  lor  eoiue  ounaidernblfi  time,  ami  then 
ftlls  very  rapidly  lo  reaoh  the  base  line.  Itul  it  may  be  duubted  wlwtber 
ifae  iDBlruineut  can  be  tnuted  lo  tell  much  more  than  tbio.  The  prasure 
noorded  by  each  lever  is  the  pressure  exerted  on  the  imipuUa,  and  ihb 
nay  coniinue  lo  be  exertc<l  after  all  hlmiil  hm  \ttren  i)ii><-harged  from 
cavity,  the  nulls  of  the  emptied  ca^nly  eliieing  round  and  prci«iiij[  un 
amiMilla.  Uut.  iia  Me  ohall  presently  M-e.  it  j^  of  gniit  inien«t  to  i)e<ermiiM<r 
Dot  only  the  furcu  and  duration  of  the  prevaure  exerted  by  ibe  ventricular 


Ttric  n«A«T. 


Flo-  -I 


,but  alio  wbetber  or  do  tlie  Gbrea  continue  cmlriict^d  iiti<l  i-x*'rlitig 
■n  for  RD  npprvcinble  lime  after  ibe  blooil  has  been  force<l  oui  o(  the 
miir.  Tb«  figure.  nii>reover,  it  i>eeil  banlly 
WaiM.  dwa  uot  by  ilftclf  tfive  any  iRfurtnu- 
liga  ■•  lo  tbe  relative  ainuuiils  of  pivwure  «s- 
ttbd  tw  the  auricle  and  veiitrid«  rMpeclively. 
liihorarve  ilie  auricular  lever  nixa  almiit 
Ufwhifth  a*  lli«  ventricular  lever;  Iml  vn^ 
■Ml  not  luAr  ftuni  tliw  ibat  the  aurit-iiUr 
<nkc  ii  half  aa  »Iroug  ut  the  veatrioilar 
Asko;  tba  fomtcr  in  amogoH  mi  ux  !•>  n»>v>- 
nnth  BDre  nawlily,  to  be  much  more  friivicivf 
IIm  the  lalliT.  The  iiwiruiiKritt.  it  i*  [rui-. 
iMf  be  cspcrinienlally  gra<liiu(r-i],  ami  ninv 
ikil  be  u(«d  li'i  ilctrnuiiti;  lln'  nclunl  ■ramitil 
rfuraailte;  but  fur  ihU  jMirjirHO  if  iiot  uhnlly 
■mclor^.  W«>  may  a<l<]  dial  ihi.'  irrt'^u- 
hMn  Men  on  thu  wiitnnilnr  vurvc  ilun'iig 
(b  mtriralnr  «yMoI«.  ami  un  the  nuriculnr 
nitr  Bt  itic  xiini«  limv,  hiivu  givi-ii  ri»c  la 
fluuh  iletiate,  uni]  ncnl  n«t  be  ilitcuwvil  here. 
0>  die  nbole,  thv  tnethod,  though  useful  for 

Jlnug  a  gnif>liie  T>ew  of  ihe  fcrira  of  eveniB  nithin  the  canllar  cavilira 
ung  a  canlioc'  cycle,  the  «hort  auricular  promure.  the  long*  eon  tinned  ven* 
tncaltf  fn^nn,  lafling  nearly  half  the  nholi-  period,  atid  the  $iibHx|UGnt 


KlniiT    \i  ( ■  ■■  ■      ■■  r.  I,  r  iinifui!  or 
tat.  Boi^'  uii  anil 


no-Ti, 


B 


n-a*a*  or  bDociuiuc  |-uo*uaa;    Pxia  Ltrr  Vixtatcu  or  tmo. 
Xa<tnratr«mllkC.II,*liHim>Mil}liniUuN.  boul.   Tlw  Mlvn  tu  tM* aa^  IM fiirMKaiaa 


2a> 


TIIK    VASCULAR    MEfll  A  SI3M. 


d«Keiil  lit'  tlie  k-ver  i.'linii^v»  In  rnli'.  liMimiiinj;  Inw  rapid,  c<>riv«pou<l' 

end  of  ilie  oultltiu  iVom  tht-  vt-iitriHc ;  )>iit  thii>  m  imt  n-rUiiii.  iind.  in>k>c<l, 

Um  exacl  internrelHtkin  ur  Ihin  pnn  nf  ih<-  nirro  i«  r«i>i>cislly  difficult. 

Ute  oeape  rrum  the  vuniricl^  iw  mptd  nnd  fi^rciUlf ;  tht^  rtnw  c<'ii>cs  fiid- 
4001}".  Hence,  a»  wc  hnvc  ntrr«ily  »iati-d,  S  I'J".  nwinp  Ui  the  mlutan  of 
bloml  teudiiif;  U>  move  "n  bv  virtup  nf  im  iiiprlin  iillcr  the  pr'iiTlling  force 
IiMCMMhI  ti>  net,  n  ticentivi-  ;>rx«»iire  m»kc»  its  appcuninre  bchinil  the  column 
of  blrxKl  ilWharKfil  friini  tlic  vcnlricte.  iind  us  eoon  its  the  culiiinii  is  Indgvil 
ill  till-  iKirlu  IchiIk  |i>  ji  irllpx  toward  the  ventride.  Thii  retliix  wnuld  nf 
ilH-lf  liiivo  llic  cflbct  of  oliwiitg  ihc  vnlves  even  vrere  the  tiurtn  ii  rigid  lube. 
But  the  iiortn  i«  extensible  and  elnstic  and  the  efl^(-l«  of  ihc  movement  uf 
the  column  of  fluid  arc  combined  with  the  effecls  of  the  movement  of  lb* 
trterial  nails ;  the  clastic  action  of  the  arterial  n-alU,  in  a  manner  nhioh  "« 
shall  di«cim  later  on  in  dealing  with  the  pulM>,  also  leads  to  a  reflux.  It  lias 
been  iirgeil  that  the  reflux  due  to  the  negative  pmnin  of  tbe  were  move- 
tnent  of  the  column  of  blood  being  more  rapid,  occurs  independently  of  uixl 
earlier  than  the  reflux  due  to  the  elastic  recoil,  the  former  closing  the  valves, 
the  latter  securin;;  iheir  complete  closure.  Be  thin  a<>  or  no  the  valves  are 
probably  clo^d  almost  imme<]iately  after  llie  escape  of  the  ventricular  ma- 
tents,  though  observers  nre  um  afreet)  upon  this  |*tiint.  some  urging  that  the 
valves  are  not  closed  until  so  late  a  period  as  the  puint  rf,  just  tu.  relaxaiioa 
U  about  to  beigin.  In  the  curves  we  are  now  wmsiileriug,  n  notch,  futluwcd 
by  a  t4w,  or  at  least  a  more  ur  less  abrupt  diunge  in  the  course  of  the  curve 
■te'.  is aointiinics  observed  in  that  narlnf  the  curve  nhich  intervenes  between 
tJio  int  lurge  Tvfe  and  ibe  Rnnt  sudden  fall :  atitl  thi.s  secondary  rise  has  btt.-» 
taken  to  indii'ate  the  oloaiire  of  the  nemilunnr  viilvc:>.  Soraetimcxi  tw<>  such 
notch (V  and  iH-aksnreaeen,  and  theni-ciirn'ni!*- nf  the  two  ha*  )>c«n  attributed 
to  a  want  nl  yyncbmniym  in  cliv  dunure  <>f  the  pulmonAr}-  and  aortic  semi- 
lunar valve«.  the  tatter  closlnj^  some  little  lime  before  the  former.  But  it  is 
by  no  means  clear  that  these  notches  and  peaks  are  thus  due  to  the  closure 
of  the  valves:  they  may  pomihiy  have  another  origin,  they  arc  not  alwaya 
pmeiit,  and  indeed  it  dues  not  seom  certain  thai  the  chisiug  of  the  valves 
should  necessarily  make  an  impress  on  the  ventricular  curve. 

^  134.  In  the  |)erf<irruanee  of  the  ventricle  then  <aml  wliat  has  been  said 
of  the  led  ventricle  applia>  also  ti>  the  right  ventricle)  there  appear  to  be 
four  stages : 

1.  A  mpid"gelting  u)i"  of  pressure  within  the  ventricle,  all  the  valves 
being  as  yet  cli>sed:  this  continues  until  the  pressure  wiihiu  the  veutricle, 
becoming  j^rcaier  than  that  in  the  aorta.  thn>w*  oiwn  the  aortic  valves. 

'2.  The  <vcn|ie  of  the  contents  of  the  ventricle  into  the  aorta,  the  oontrac- 
tion«  of  the  ventricular  walls  still  continuing. 

:!.  Further  mninletiunce  of  the  contraction  for  some  little  time  after  the 
main  body,  at  all  events,  of  the  cuntenLx  bare  paawd  th«  aortic  valvos;  by 
this  the  compktc  emptying  of  the  ventricle  Miaiut  nasured. 

4.  f^ddcn  and  rapid  rvTiiXBtion  of  the  ventricular  walls. 

These  four  events  together  nmko  up  a  large  |K>rlion,  and  tu  «  quickly 
be«ling  heart  the  greater  portion,  of  the  wholo  cardiac  cTcle. 

Meanwhile,  that  ts  during  the  lime  froin  t/'  to  u.  blood  has  been  flowing 
from  the  j^reat  veins  into  the  anricio :  during  the  interval  from  h'  to  d  Douo 
of  ihifl  can  pass  into  the  ventricle  since  this  is  slill  contracte<l.  but  with  th« 
oomniencenient  of  relaxation  fnmi  >'  onward  there  is  no  longer  any  obstacle; 
on  the  oonlrary,  as  ue  shall  see,  an  induc«menl  for  the  blood  to  pass  from 
the  auricle  into  the  vciilritle. 

For  n  brief  time,  as  we  have  seen,  there  is  probably  an  unbroken  flow 
from  the  great  veins  (pulmonary  or  vens  cavic)  tbroujjb  the  auricle  into  Die 


ide,  lt»diii){  ii>  m  Mvftdy  l>ui  aliglit  in««aM  of  tlie  frouMo-back  diam* 

bi  >  »Jt]cht  |>r<i«ure  of  ibe  a]iex  on  ibe  cbc«t-inill,  nml  in  a  xlight 

bicrtaM  iir  inim-vriiiriciilar  ]>rcMur«,  cmiemlljr  Hlmnu  in  the  curve  nr  the 

riovljr  bmtlng  Itiwrt  i>f  tlii'  bon>e(Fiy.  li).     lu  Pig.  76  the  suilili-n  riw  i!uG 

luthv  ventrkular  »p(i}lo  im  precwk^H  by  a  riw  fc  luIlow«d  hfn  (all.  forming 

Ibo*.  a*  It  wen',  a  *lii>iil<k-r  im  tb«  curve.     ThU  hiw  l»p<in  iiil('r|>rolixl  u»  inili- 

(aitag  tbr  aliarj)  Iriinnii-nt  aiirkolnr  kvhKiU-;  tlic  Huildvii  iiijci-tioii  of  llt« 

aaricular  coDti-uia  into  tlic  v<intridi-  iiirn.-iiv:s  tbo  fronl'lo-back  diatn«tcT  of 

tU  natriclc,  anil  tlw  iiiuiiiuiiUini  >'!'  ib^  rtipiil  •tr»kv  being  coneidcrablo,  tbo 

Uvn  i*  in  MU-ti  ca«e  carriod  Um>  far  furwar^f,  mt  tlinl  tbc  riM  u  Ibllowcd  hy  a 

bU.  pTQituciag  a  notch.     A  fimilnr  thougli  eomcnhat  diflcrvnt  shoulder  is 

■Iv  ttm  tn  ibn  cnnliogntra  Fig.  77.     In  the  curve  of  ventrimlar  |)reMUT« 

tabs  by  moaiut  of  the  cardiac  Miind  (Fig.  74)  iheni  it  a  rituilar  leinpnniiiT 

iHraM  A^  in  the  vi>otHi.iilar  prrssiire  coincident  nith  the  auricular  iitroke  o, 

•ad  in  i1m>  "  pi<U)U  "  pressure  curve  of  lli«  rapidly  beating  heart  (Fin-T.i.A) 

that  b  a  ninilar  thotilder  6  Jti»l  preceding  the  ti^  of  the  veotriculur  systole. 

Tk  amtirnf;  of  ibe  lasl  curve  is,  bovrever.  doubtful,  for  io  tbc  siniihtr  curve 

otiht  iBon  alowly  beating  h«art  (Fi^.  75,  B)  it  occun  inimediuiL-ly  al\er  ibe 

niniliiin  of  ihe  ventricle,  eume  lime  ii^lore  the  nccurrt-nee  of  iIil-  ntiriciiiar 

vnlola.  aod  )<■  tDany  mrven  takvti  by  ih«  tuime  methixi  h  ahttent  uluigeiber. 

m  ftact  nuiininK.  tberefure.  of  lli«  tibouldvr  b  in  the  other  curvea  niuni  l>e 

Mstiinwni  iindn-ided. 

t  lis.  \V>-  liiiV4'  Mlill  «i  coimider  tbo  DC)(ativo  prcMure  abonii  br  chc  mini- 
■an  nanomi-U'r.  Thi>  iuHlrumeitt,  an  we  have  Mid,  merely  •hnws  that  the 
fnmnn  in  the  virntridc  (nr  aurtcle)  beoumea  oegativu  at  ft^mo  pbaae  or  Other 
af  the  canliac  cycle,  Ixit  ilovx  nni  tell  ui  Ln  which  pbaie  it  occur*. 

}i<im  there  are  tno  iriiv>  in  which  irucli  a  negative  prwduro  might  nriginata. 
Id  Iha  flni  place,  a»  ne  have  just  Hxn,  u  negative  prewurc  makcM  its  npjwar- 
aaea  in  the  rear  of  Ibc  colomn  of  blrHHl  driven  from  the  ventricle  into  ihe 
aota  with  great  suddenness  and  rapidity.  But  this  negative  pressure,  ns  we 
hiTt  ako  Mxa,  fulluws  the  column  iaio  the  aorta  ]>a«t  llic  semilunar  valves, 
aad  in  pan  ai  all  event*  determine*  the  closure  of  tbc  semilunar  tnlves- 
Utwe  if  thifl  i>  tbc  negative  prrasurc  which  the  minimum  manometer 
fteanlik  it  ouaht  tn  I>e  abonn  not  only  wlicn  the  end  of  tbc  tube  conueetetl 
vU  ibo  nuuiuiueter  is  in  the  cavity  of  the  ventricle,  but  uIm  when  the  tube 
M  •Upfwd  nut  of  iJie  ventricle  just  {>asl  the  semiluuar  valves.  W'bttu  ibe 
tA»t  Bowewr,  la  in  the  latter  eitiialiun  tbe  manometer  does  not  shuu'  the 
«Me  Bisrked  negative  pmMire  that  it  does  when  Ihe  tube  is  in  the  vetilricle; 
(he  nmaiirr  pnMure  which  (lecura  in  the  aorta  at  each  beat  h  iusuffideiit  to 
mdace  Mich  an  elferl  on  tbe  minimum  nianoineier  lu  is  produced  when  the 
B«ot  i*  in  the  \-enirieIe.  iieucv  we  infer  tiiat  tbe  uegaiive  prewute 
by  tlw  minimum  uiaiioineler  u  not  produivd  in  tbi.i  nny.  ^^  e  may, 
rmr,  outidude  that  tbi;  .'«niiltinar  vah-ee  are  cloHeil  In-fore  thi*  negntive 
\n  oinkta  ita  ap|wanuice  in  tlie  ventricle;  otlK-rnis-,  iiowever  pmiluivd, 
il  wiMild  l>e  traikMnittcd  from  tbe  interior  of  tbe  veutricio  through  the  upcii 
talm  to  the  root  of  tbc  aorta  lieyond. 

But  tliere  is  another  event  which  might  give  ri«  to  a  n»ativc  pfwsure. 
Tha  rrlaxation  of  the  vetilricular  walU  in,  a«  lite  ciirvcH  (Pigx.  7-^,  76,  77) 
4feir,  a  rajnd  prooeas,  something  (piile  dinlincl  frMn  tbe  mcro  tilling  gf  tho 
iwtrirulnr  cavitica  with  hlooi)  from  tbc  anrieteai  and,  though  cumo  bava 
4ijii  Hd  III  the  view,  it  tniiy  be  urged  tluit  lhi:i  return  of  the  ventricle  from 
in  mklnuled  (and  empUeil)  oindilinn  to  itM  noroiul  form  wmild  devi-iop  a 
■^aiin>  praauro.  This  return  io  proiMbly  niniplv  llw  total  mult  of  the 
mrs  of  each  Hbre  or  tibre  cell  to  it#  nniurul  comfitiou,  tlmiigb  some  have 
ojgw)  that  the  extra  quantity  of  blood  thrown  into  tbo  ooro&ary  artrrita  at 


S22 


TUB    VJ 


LR    XKCIIAS'I 


the  E}-slot(>  help*  to  anfoUi  the  ventricles  aoinoirbat  in  ibc  wnv  ihnt  fliiM 
(Irivpii  Wlweeo  tlie  tvo  walls  of  a.  clou ble-wal led  c»1Iiijjm>(1  balfur  mip  vrill 
unl'tilil  ii^ 

Ai'cepuug  the  return  of  the  veutricle«  to  their  nurmst  form  ii>  ibi*  cnuM 
of  ihe  lu-eiiiive  prawure  (au<l  it  miiy  l)<>  rerunrkfil  thni  Ihi;  rpliirn  of  lb« 
thick-v>alleil  \etl  veDtricle  oaturatly  exerts  n  K<^riiit-r  ni.-gutiv«  [irowtin-  than 
the  tbiii-K'uIled  right  ventricle),  it  in  itbvioiis  that  tJie  iieguiivf  jinittnirD  vill 
aBrixt  the  circulation  by  Duckinjc  the  hlmn)  which  hiw  mMiiiitbilr  li«eii  acca- 
niiilated  in  the  aiirli-le  iVom  that  cavity  iiifi  the  ventri(!1l^,  the  aiiriiiilo  vcti- 
trietilar  valvun  easily  )(iv)iix  way.  At  ihf  Hanie  timf^  thi«  vcrv  flow  from  the 
auTicli-  will  at  once  put  an  end  lii  thi^  UL*gative  prvwurp,  which  nbvioui^lv  can 
Ih:  i)f  brief  (luratiun  •mir.  It  may  further  bi*  urgvd  iu  :iup|>ort  of  this  vtow, 
thai  evGii  when  l\w  thorax  in  i)p<-Heil,  *o  that  thi;  nt^piralorv  niovemcnta  caa 
ii(>  loii^r  act  lounri)  producing  a  iiegiiliv«  nrewiircr  in  the  auricle  and  fireat 
v«-iii»  <  S  1-11 ),  a  tnitiimuni  ninnonictcr  placi-i)  in  lh«  right  nuHcle  sli(>w»  fre- 
quently oil  prtwiirc  at  nil  ilhnt  ir,  a  prt^mrcciinal  it>  ihal  orih«attn(»pher«l 
KD<I  unmet inic»  a  drdih<tly  nc^tivc  nrcmiire.  .Sdoinj;  that  the  blood  under 
thp>c  nrcunMlanfra  i»  being  driven  along  the  great  vvina  by  a  )>ref«ir«  which 
though  low  is  alnayx  abovo  that  of  th«  atmotphere,  w«  may  uuuclude  ihal 
the  negative  previirf  produced  in  die  vcntriclo  ix  the  cause  of  this  IdweriuK 
of  the  prewurc  in  the  auricle,  ihotigli  it  it  unable  to  make  itself  felt  ahiii); 
the  greitt  veins. 

§  136.  Th«  •liiration  of  Ihf  trrernl phntfr.  We  may,  lirat  of  all,  dbtin)fuUh 
certain  main  pliaiteH:  [\ )  Tbesyatoleof  theauriuW  VSj  The  systole,  proper, 
of  llie  vfBtrieleB,  during  which  their  fibres  are  in  a  state  nf  contraction,  Itut' 
inn  to  '/  in  FlgB.  75,  Ttt.  77.  (:1)  Tbe  dijiHtole  of  Ihe  vent  rides— that  u  to 
Bay.  ilie  time  intenp-eDing  between  ibeir  llbres  eeaaiufi  to  contract  and  cnw 
Diencing  to  contract  again.  To  tliew  we  may  i>erha[s  add  t4)  The  iiaui(c  »r 
rcsil  iif  the  whole  heart,  comprising  the  [leriml  Irom  the  ejidollhc  rvlaxatioa 
of  the  veiilriclw  to  the  Id^inning  of  lUe  systole  of  the  auricles  ;  iluring  thia 
lime  the  wnll#  are  undergwtig  no  active  change*.  Dcitbi-r  rt>ntrnctiug  nor 
relnxing.  their  cavities  Iwiug  simply  piusively  filM  by  the  inllux  of  blood. 

The  mere  inspection  of  nrnuwl  nay  wrie?  of  cardiac  curves,  howeviT  tnkea 
— Ihoae.  for  instance,  which  wc  hnw  just  i)i*CUMcd — will  show,  apart  from 
any  accurate  measurements,  ihnt  the  svslole  "f  the  ntiricles  is  always  very 
brief,  that  llie  systiile  of  ths  vcntricUs  is  alwuys  very  prolongwl— always 
Qccupviui,'  a  conBidcrablc  portion  of  the  whi>!c  cycle-  -and  that  the  diastole  uf 
ll»e  whole  heart,  reckoued  from  the  end  either  of  the  systole  or  of  Ihe  relaxa- 
tion of  the  veiilricle,  is  very  various,  tx'ing  in  <]uickly  beating  bearta  very 
ahurl  and  in  slowly  beating  hearts  decidedly  lunger. 

When  we  desire  to  arrive  at  more  complete  mensuremenis,  wc  are  obliged 
to  make  me  ^>f  calculations  based  on  various  data;  and  theee  give  only 
approximate  results.  Naturally,  the  most  interest  ia  attached  to  the  dura- 
tion of  eveuta  iu  tbe  human  heart. 

T1i«  datum  which  perha|M  ha§  been  most  largely  used  is  tbe  interval 
between  the  beginning  of  the  Hrst  and  the  occuiTenee  iif  the  second  sound. 
Thitt  may  be  iletermim-d  nith  approximate  correctness,  and  ia  found  to  vaiy 
from  O-Sftl  to  11.327  w^imd,  occupying  from  At)  to  4G  per  cent.  i>f  the  nbule 
|ier[t>d,  and  tiring  fairly  ouiniant  tor  <li8erent  rates  of  heiiri-beai.  That  i»  to 
aay,  in  a  rapiilly  iH-nliug  lii-url  it  ii  the  juuses  wbicli  are  nhortencd,  and  not 
the  duniliiin  nf  tliv  aeliud  hi-at*. 

Tbe  Dbaerver,  iMtenine  to  (he  sounds  of  the  heart,  make*  a  •ii(uaJ  at  eJich  eveiiL 
•<■  a  rvcurdiii](  Mirlace,  lue  dtflrrencn  in  time  litlwci-n  tbe  niaila  being  lOMunired 
kby  BmnB  iir  the  tihralions  of  u  lutiitii;-t'ork  recurded  on  the  tame  aarface.     I)r 

imutice  it  is  fuuod  [Nmible  to  reduce  tli«  errorsof  obaerratJoa  within  very  smalt 

limits. 


THK    UKART. 


^2S 


Xow.  wKikiCTrr  beihv  exnd  cmiMiiiun  of  ihv  tir»t  »i>i]n<I,  ii  in  ani)oul>lcdly 

11  «illi  ihi-  Kvxtoli-  of  lh«  vpiitm'U**,  thi>ii<!li  tii<s<ili!v  llw  iicluiil  com- 

Dtni  of  iu  Imiiiiilii^  aiiilihir  nuir  Ix*  iili^lilly  iH'tiimi  ihc  itctntil  iicgin- 

Tiin^  nf  ilir  tiiiiKCiiliir  cotiirmcltniia.     i^imiliirly  ihc  nrciirrvncv  of  the  tecciDd 

■juntl,  whidi,  iiit  wr  h»v<-  -vu.  U  (H-rminly  due  in  llir  clinsiirc-  nl'  the  ■enii- 

loDftr  Tilim,  hiu  )>ct.'fi  litkvii  !•>  tnttrk  lln-  cliwc  nl'  (he  veiitriciilar  »vst>ile. 

And  iin  tkU  ■D|>|NN>i(iuD  Ihv  intonal  hrtnci-R  the  hc^iiiniiiif;  of  tlie  tint  aud 

llw  iicrum-iiri'  of  tl>e  i^cniKl  tumnd  hns  l)c<n  M-iiHnictl  lu  inilioiitin);  »|>pr<>xi- 

ouilrty  lilt'  iliinitiiiii  uf  thr  v-cntri<:(il«r  rvfIoIc — ■'.  c,  ihv  pvritKl  during  wliicli 

ih*  trnlririiliir  fil>rii>  arv  coiiinictiiig.     \Vt>  liiivv,  howover,  orj^d  abuvc  ihat 

tli«  vmlni-lri  fttill  rvniain  coDirnctcol  fur  ii  brief  period  n^er  ibe  valvn  are 

tk»l:  if  tlii»  viv«T  1m>  cwrrccl,  llicn  tbp  iwcond  cuuiid  dms  not  mnrk  the  end 

tf  tkf  fifiole,  UMJ  the  duraiiiMi  of  tbe  sjHtole  is  milwr  longer  that  tbe  time 

■imi  above. 

ibf  I  lot  ertiii  nation  of  lb«  tcnaralf  diirnliou  of  eucb  of  the  thrue  jieriutU  (d' 
tbt  iFiilricuIar  Bvatolt' — vii.,  the  ]>t^iliii^  up  ut'  lb«  prtsaure,  the  <lUcharge  of 
tb(  niiit«nl£.  nnd  tb«-  reiiiainiiij-  eniplieil  but  cuiuracled — is  mibjec't  tn  no 
BuA  unnrtainty  ihiit  ii  ueeA  not  be  ioBistcd  ou  iii-re;  it  may,  buwcvcr,  be 
ml  tkat,  ruuKbly  ajieakiiiK.  «^:>L-b  phiue  occupies  probuhly  iibout  0. 1  wound. 
In  0  li«uri  tumtini:  72  timcii  a  iniiiui^,  uriiieh  mar  t>e  tukeD  as  tbe  normal 
nif, Mcb  i.tiiin:  ciirdiiii:  cycle  would  la^l  abiiut  6>^  d^Muiid.  ami  taking  0.'^ 
mod  a*  ibc  duratioii  of  ibe  venlrietilur  ByHiokMbc  deduct  Juii  of  tbU  wiuild 
Invr  a^  wctiud  for  tbu  whole  diaalole  of  (hu  vciiirii-le.  iiicludiii);  il.-i  n^laxti- 
Unn.  tlir  Intlrr  orcupyiiiK  ubotit  or  sumowhiil  Wji  iliaii  0.1  iu.t?i>iid.  In  thu 
liatr  part  of  tbiii  period  iht'ru  occunt  Ibe  M'stole  of  tlir  aiiricln,  tlii;  cxucl 
duruii'i  of  wbicb  it  a  ditlii-iilt  to  dcterniiiip,  it  being  ban]  t»  aity  wlu-n  it 
mlly  U>'ina.  btil  vrlii«b,  if  tbv  cviitrnction  of  the  grau  v«iiis  b«  iucludul, 
luy  [Thara  be  taken  ns  la«titt);.  "U  no  Mvemue,  0.1  wond.  The  "  |iuB«ire 
bimal,*'  iberefore,  during  which  nHther  iiiiric^  nor  ventricle  are  undci^iiiig 
BMfaUiufM,  lasts  about  0.4  hocoikI,  and  tbe  alji»olut«  paiii»e  or  rest  during 
viich  iMritber  auricle  nor  ventricle  are  contracting  or  relaxing,  about  0.3 
■cowl:  if.  however,  a  longer  period  be  allotted  to  the  ventricular  eyslole, 
lUw  perioiU  muat  be  proportionately  Hhurleiied.  Tlie  iVBtote  of  tbe  ventricle 
Mloiraao  iinmediaiely  upon  that  of  ibv  auricles,  that  practically  uo  interral 
aiirt»  between  the  two  evenli. 

The  duration  of  tbe  iteveral  phases  may.  for  convenience  luike,  be  arranged 
is  s  lalnilar  form  m  folloun;  but  in  reading  the  table  the  foregoing;  remarks 
■t  la  tbe  appruKiRiale  or  even  uDcerlaiii  character  of  some  of  the  dalA  must 
W  Imnw  In  raim). 

^tfole  of  vetitr(c)«  belore  the  opening  nf  die  Minilunnr 
Talvei,  while  picMure  ia  atill  getting  up  {probnltly  ralhrr 

iMthaa) Il.l 

beaiNr  of  blood  into  aorta  (about) 0,1 

Cb«tinu«d  ooairactlon  of  tbe  emptied  Tentriele  Ipoaslbljr 

rather  mure  tliant 0,1 

Total   *y«l«la  of  the  ventrit'le  (probably  tailivr  nxxg 
ihani   


IHaabile  uf  both  aarii'le  Rn<l  vMilricte.  neillM'r  oontracting, 
••r  '*  paaaive  Inlvrvul  "  (pn>l>ahlv  rather  leas  than)     .        .    0.4  I 

Ryatole  nf  auricle  ^abtxit  or  leM  tlmn) IM  j 

lKa*(i>l«  or  vciilricle.  iiiclu'linj:  rrt>xiiti"n  and  filliiiir.  up  to 
lb«  txf  inning  uf  the  vcnuiuulur  ivsiolr  ((irotiably  tiiilicr 
Ina  Ihao) 


0.8 


0..> 


Total  cardiac  cycle 


0.8 


224 


rs   VASOULAB   llECnANTSK. 


Summari/. 

!  137-  We  mny  iww  bricfl)r  nninintiilitU'  l]w  main  fitcte  coiinecloc)  willi  tlx 
posnge  of  bliHMl  through  the  liritrt.  Thi-  right  auricle  ilitring  il>  din»litl«, 
by  the  rclitxnlinD  of  iu  imisculur  dhm,  nntl  bv  lli«  liict  (hat  nil  bnckwnni 
preAuro  frum  rbc  vriitrii-Ie  is  rcinovixl  by  the  closiug  ofUM)  tricuspid  vnlrea, 
uHon  but  Unit;  ri-siftdticc  to  (he  ingrivs  »t'  blood  from  the  veins.  On  lbs 
other  bncid,  the  lilood  in  the  tninks  of  buth  the  BU[>crior  miil  liirorior  vena 
cava  i»  under  n  prcMUre,  which,  though  diminishing  b>«-ard  the  heart,  re- 
luains  higher  thuti  the  pretaure  obtaining  iii  the  ititerior  of  the  auricle  ;  (be 
blood  in  cotiwjijciice  dows  into  the  empty  auricle,  its  prourcse  in  the  case  of 
lh«  superior  vodb  mva  bcinj*  atdisted  by  gravity.  At  each  inspiration  thb 
tiow  (as  wcchall  aee  in  ^pealciitg  of  respiration )  is  favored  by  the  dimiiuitioD 
of  prcflBurc  ill  the  heart  aud  great  ves««ls  caused  bv  the  reepiralory  loove- 
nients.  Before  this  How  liau  gone  on  very  lon^.  the  diastole  of  the  ventricle 
be};iii6,  'H»  cavity  dilates,  the  IhipA  of  the  tricuspid  valve  fall  back,  and  blood 
for  fiouie  little  tirne  tloiva  In  itu  unbroken  stieaiu  from  the  vena-  m\x  into 
ibe  ventricle.  In  n  »liori  limii.  howevtr.  probubiy  before  very  much  i>luud 
h»H  hud  time  M  enter  the-  vcntrii'k-,  the  auricie  id  full ;  and  furthnith  ita 
Hharp  sudden  sysiok-  tnko  place.  Partly  by  rea^in  of  the  buckwan)  pr«B- 
jiuru  ill  the  veiun.  which  incnruofs  rupidly  from  the  heart  towmni  the  cupib 
Inricn,  and  which,  at  foinir  diataiici-  IVoiii  thi-  heart,  in  OMinted  by  tin-  proenoo 
of  vulvi-s  ill  ihr  vtnoNit  triinkf,  but  Mill  miin>  from  thi.-  fact  that  the  xvrioU; 
begins  at  ihi?  grrat  veiuN  thrmM-Ives  and  spreads  thence  over  the  auricle,  the 
Ibfxw  of  llie  auricular  oonlnielimi  i>  £|>ent  in  driving  the  bigod,  not  liack 
into  the  reins,  but  into  the  ventricle,  where  ihe  pri-wum  in  utill  excceflingly 
Ii>w.  Whether  there  u  any  backward  How  at  all  iritu  the  great  vcIr«.  or 
vhethor  by  the  progressive  character  of  the  systole  the  flow  of  blood  oon- 
tiuuee,  io  to  speak,  to  follow  up  the  systole  without  break,  so  tbnl  the  Mreain 
Irani  the  veins  into  the  auricle  is  really  cuutiniioue,  is  at  present  doubtful; 
though  a  slight  positive  wave  of  pressure  synchronous  with  the  auricular 
ayaUile,  travelling  backward  along  the  great  vcina,  baa  been  observed,  at  least 
in  OUHB  where  the  heart  la  beating  vigorously. 

The  ventricle  thus  being  tilled  by  the  auricular  svaiote,  the  play  of  th« 
tricuspid  valves  described  above  cornea  iniu  action,  tlie  auricular  iysiole  is 
iblluwed  by  that  of  the  ventricle,  and  the  jire^urc  within  the  vetitricle,  cut 
<dr  frQm  the  auricle  by  tht-  iricii^pid  valves,  in  brou^-ht  to  bear  ou  the  pul* 
monary  leinibiDar  valven  and  the  I'libimu  of  blood  on  the  other  aide  of  tritno 
vatrea.  Aa  noon  aa  by  the  rapidly  inereti^dn^  shortening  of  the  ventricular 
fibnn  the  prc^aure  nitliin  the  ventricle  beouiuea  greater  than  that  tu  the  pub 
uionnry  artery,  the  iiemilunar  valven  open  and  the  alill  continuing  nyatolv 
duobareCH  the  contonts  of  the  ventricle  into  that  ve^isul. 

As  the  ventricle  thui>  ra|>idly  and  lorcihlv  einptien  itni-lf.  either  the  trnnjucut 
Dcgative  prauurc  which  innkra  it«  aj>pearance  in  the  rear  of  the  i-jected  colunia 
4>f  blood,  or  the  eln»tic  action  of  the  aortic  wall*.  IcuJh  tu  a  rellux  of  blood 
lowanl  the  ventricle,  the  eft'ect  of  which,  however,  is  to  close  l)ie  iwniiluiiar 
volvw*  and  tlni#  to  i>hut  off  thu  blood  in  the  dwteiided  arlericri  from  tlio 
emptiefl  vQiilricle.  Kither  iinme<lialely  at  or  more  probably  fi}mv  little  time 
■Aer  this  dooingof  the  valves  the  venirieulnr  Kv»iole  emlif  and  relaxation 
bt^iDs;  then  once  aum  the  cavity  of  the  ventnclo  bueomtw  unfohlcd  and 
finally  divtciKlcl  by  the  influx  of  blo<Kl,  a  negative  prexiure  devolopc^l  bv 
the  relaxation  probably  niiliiig  ihc  How  from  the  auricle  nnd  greal  wins. 

Utiring  the  whole  of  this  time  ^e  left  eid«  bag  with  still  grotMr  eaotgy 
been  eJteoutiug  the  same  inanceuTn^    AtlhesaniQ  time  thai  tha  von»  cavn 


THK    UEABT.  22S 

•n  Uioy  (be  riKht  iiuricle,  the  pultnoniu-jr  veim  are  fillioi;  llie  left  ■iiriclv. 
Al  l^mne  time  thai  die  risKt  auricle  ia  cMntrai-tin];,  itie  left  auricle  it  coR- 
ITUtiDi;  Uw.  The  BTBtole  of  tlie  left  v^eotncle  \a  syDcbrnnous  witli  thrtt  uf 
Uttcunt  \-rtiLri(;le,  Imt  executed  wiili  frailer  foree;  siul  tlte  flow  of  blood 
a  gnnn)  •■n  ilie  iHt  liile  by  the  iiiitrul  aod  aortk  valree  in  th«  aamc  war 
ilni  it  is  on  tlic  right  by  tbe  lricuj»j>iil  valves  ani)  the  viUves  of  the  pul- 
murT  arwy- 


"Hftati  in  a  givcu  |)erio(),  but  pi-rluiDS  the  must  importaut  factor  of  nil  in 
ih  dtUnuinatiiiQ  of  the  nork  of  llie  vasciilur  niecliuDisni,  the  <|Uttntity 
qstted  from  the  renlricle  iulo  the  noria  at  i?acli  systole,  cannot  as  vet  be  said 


The  Wort  Oow. 

)18&  W«  can  muiMire  with  apiirosioinlivc  exactness  the  intrn-rcntrii'ular 
in.  tbo  U-iiglh  of  Mcb  «yBlolc,  and  the  number  of  tinKv  the  systole  ia 


tobtTe  Iieen  aecuralely  determined  ;  we  are  largely  ublijjed  to  fall  back  oo 
nlealationa  liavinf^  inanv  sourcee  of  error.  The  jceueral  result  of  soioe  of 
ihaamlculaiioosgivca  aFiout  ItSO  cramuia  (<j  oxa.)  u  the  quantity  of  blood 
vlitb  it  driven  from  each  ventricle  at  each  eysu>le  iu  a  fiill-j^rown  man  of 
I  sice  and  weight,  but  Ibiii  e«tiraale  k  probably  tui>  bi;;li. 


Im  tb«  dog  tlifl  iiuauiil^  liBB  been  vi|ietiiu»n tally  <lei«nnined.  by  allowing  (be 
fcauitoddlver  iia  eonteobi  iliroujcb  one  branch  or  the  aorta,  all  oibera  being 
"p^T^  or  blocked,  into  •  reooiviT.  (he  contents  of  wliich  are  at  iotervnl*.  by  an 
Upaloai  coBlrivjini:*,  rriiirni-rl  in  the  right  auricle.  Tha  time  takon  ta  fill  the 
nniw  aitd  tbc  [luuilwr  »f  Wata  eiccuted  during  ihiil  time  hviag  aoted,  the 
annn quantitT  aitict«d  at  a  beat  la  tbiuciveii.     It  ia  found  to  vary  very  widely. 

VatttM  Betbovi  have  been  adopted  lor  cal(;ulatiag  the  average  amonnt  of 
Und  ijected  at  each  rantrictilar  Hystolc.  Tlie  almpleAt  method  U  to  meaaare  the 
oifadtj  of  the  rfcmlly  rpmavcd  and  m  vet  not  rigid  ventricle,  flllod  with  blood 
•Mf  1  rirrware  e>iua1  to  tbo  calculated  nwnfe  prea*uro  in  the  veoitricle.  On 
At  ■  >ii   that  tbe  whole  cunienta  of  t£e  T«alricle  are  iMMtcd  at  each 

■fi:  -juld  give  the  i]naallty  driren  Into  tbe  aorta  ul  each  Htruke.     The 

w«tbwl«  arc  ret;  indirect. 


It  ii  CTHleat  that  exactly  the  came  ijuantity  must  inue  at  a  beat  from  each 
fntride:  ibr  if  tbe  right  ventricle  at  eaih  beat  gave  out  rather  leae  than 
ll>  kft,  after  a  certain  number  of  l>eatA  tbe  whole  of  the  bkwd  would  be 
plLiiil  in  the  svstemic  circulation.  Similarly,  if  tbe  left  ventricle  gave 
Ml  !■■  than  tbe  right,  all  the  blood  would  soon  be  crowded  into  tbe  lunjf*. 
1W  tun  that  the  pr«aaure  in  the  right  ventricle  ia  »o  mucb  leM  tlian  that  in 
(he  left  (prabably  30  or  40  mm.  aa  comimrHl  with  200  mm.  of  mercury),  is 
Att.  not  Iu  dlflbraioes  in  tlie  tfuautilv  of  blixid  in  the  cavities,  but  to  the  liitct 
tbal  ibn  ]>rri|>licnil  redttance  whidi  baa  to  be  overcome  in  the  lungs  b  so 
smefa  I^  than  that  in  t^  iwM  of  the  body. 

Il  moat  be  mnemWred  that  though  it  ia  »>'  nilvaninjei^  to  nwuik  «f  an 
tnrage  rjnnntity  tjerted  at  vach  atnike,  it  ia  more  than  pn>bablc  that  thai 
^•aaiiiy  may  vary  witliin  very  wide  llmila.  Taking,  hawcvvr,  180  grammes 
»  Ibe  r|u«ntity.  in  man,  tjecteil  at  each  stroke  at  a  pnxauiv  of  2-V>  mm.'  of 
OMTury,  which  ia  oquivaieni  to  3.21  melren  of  bloud,  this  meaiia  that  lite 
Ul  Teatricle  e  capable  at  its  systole  of  lifting  180  grammes  3.21  melna 
y^  i.  a.,  it  does  57H  gramme-metres  of  work  at  each  benU  Supporing  llx- 
Mft  lo  beat  72  timex  a  niinuta,  this  would  give  for  tbe  day's  work  of  tbe 
Ul  v«Btrid«  nearly  (JiMXX)  kilogram in«>metrcs.  Calculatingtlwworkof  lbs 
fifU  reotricle  at  one-fourlb  iTiat  of  the  left,  the  work  of  the  whole  h«an 

<  A  Wall  caOmaM  I*  |art«Hlr  UkcQ  kuv^ 

IS 


S36 

would  nmouiit  lo  75,000  kiiograuime-melres,  which  ia  jii«t  ubotil  the  aniotint 
of  work  tlciiu  ill  (111'  nHveiit  ol'  Sijowdon  by  a  tolerubly  heavy  iubd. 

A  cnlciiliitiun  of  more  [intcliciil  value-  U  the  lollowiDg.  Taking  the 
riuatitity  of  bUiod  n*  i*i  n(  ihe  hmly  wei^ihl..  the  bloud  nf  a  man  weighing 
76  kilus  would  Iw  about  A7G0  grniiiiiivM.  If  180  ajaminea  leA  ibe  veolricle 
•t  each  beat,  a  ciunntity  C(|UivuIi:iit  to  the  whole  blood  n-ould  paoa  ifarougb 
the  heart  in  3*2  beale,  *.«.,  in  k«t  than  half  a  minute. 

Tiis  Pruiii. 

^  138.  We  have  seen  that  (he  arteries,  though  always  dislcnded.  undergo 
at  each  systole  of  the  ventricle  a  ti?mporar}'  additional  disteunoo.  a  Icmfuirarv 
additioual  expansion  s«  that  uheD  the  tinker  is  placed  on  an  artery.  *iich  ua 
the  radial,  on  inlerniillvnl  |>reature  on  the  linger,  comio);  and  going  with  the 

Fro.  IS. 


n«1t  tmm  MuioHirrn. 
in*  flalloued  Inlic  111  tlw  f^irm  Of  •  liaop  t*  ami)- ttinl  u  uiio  md,  vhflo  Ihc  al>»t  tn»  •nd  U 
•KmIknI  Ma  law,  Thu  liiUilur  of  llm  liilir.  ttlM  wltli  iiilril.  Ittuniufhl.  hf  lurvuof  ■  inteooi)- 
ntnltic  Mdluia  oniboniitv  Kiliilloii,  liiro  ninnrrili.n  wtih  nn  aMcrT.  In  mui'h  tbe  Hmc  hajmId  llie 
(■■I  tit  Uio  Dtimi;  DiaiuuuelQi.  Tht  luvrcue  vf  [ircBurc  lu  tbe  aner}  Uilug  tiuminliwil  lo  u« 
ImUowIiDop,  UiuUluflnlKhUn  tt,  aDdc>'iTM[ianillDirly  nKn«>  tb«  Bllwb*d  t«itr. 

beat  of  the  heart,  h  fell,  and  wbeu  a  lt):ht  lever  is  ]>laci-d  on  tbc  nrterr,  Iho 
lever  i*  raited  al  «ach  boat,  falliuE  hetwt^en. 

Thi*  intermittent  L-ximnsion  which  wc  call  the  pulw,  corrwprmding  to  the 
jerking  outflow  "f  hlood  tVinn  a  severed  artery,  is  im-wnt  in  the  artenc»  only, 
DeiDiF,  except  under  panit'ulnr  circumNtnncca,  aWnt  from  the  vrius  and 
cafiillBricM.  The  es]Hui»]on  i*  fn-iucnlh-  vinhlc  to  tbc  eye,  unit  in  some 
cases,  us  where  an  artery  has  a  hend,  may  cniifc  n  certain  amount  of  loco* 
motion  of  the  Tnsel, 


THE    PUt.SE. 


S27 


iitatyonrj  iucivntt  of  preoHire  wliicb  is  tlte  cauM  of  the  temporary 
01  oxiMiiMOD  makes  ilself  fell,  as  we  faavo  seen,  in  the  ourra  of 


rra.T>. 


IiusRiH  (M  >  BrnvnuoaiiArii  iDiiiA>AN*n. 
II1|H<IIIH  |auM uc oflilncd n  that  Uie ■aUlptjliiE  tctrnmiaj'bedliptoTod.    d  tin  nuall 

»(if  UMknrtalimiiiMtMdpabitil.  Tlw*  an  rominunlaiWd w uid nu«- 
I  If  tt*  ln«t «  wlilcli  iBona  roaiid  ib>  Bzwl  fdnt  /,  Tbe  live  'nd  or  (hit  lenr  BoiiUi  b  tight 
■MMr  <rUtk  iwHoaftMnpottanlud  raptr.tr-  Tt«  |iai«r  Si  plKvd  bvocaUt  two  mull 
•(  IMM  <■  ■  ioSm  abMi  «■  t«  rotolod  bj  ausoi  of  rtock-xirk  ociaUJn*d  la  Uw  bpt  k. 
1kt|i9«rltihai«a«i(1totniTeUt>anllbrmm*.  nttrnw gnAuiua  lnoiuioa(TTaT)talmiBlM 
•  ta*  M  Ih*  ifAliB  *  tV  niMiia  of  a  MBm.  and  t>)r  iMt  Ihd  pnmuf  pul  oq  Um  iirUfy  (nn  b*  Ntfu- 
■■a  tkt  ItfW*  OMpaltr  Ik*  |uIm  mtanaaviM  llttjr  ItmM. 

MnU  pWBW  lalcciii  bv  ihr  mrrcnry  mnmimclcr ;  but  the  ini-rtJa  of  the 
[jmrcoto  th«  epCL-ial  vhiu-uctcn  of  ctu:h  incrt^uec  bot'oming  visible. 


HiBit'i  t!riiTn»mR>rli. 

VXb*kOTiitaw<ii|irr'n'V*i>iii*<>M'i>'<i  i»tbo«m.  lt,if(tiia>klcfefaiiiipiNi  tadlaluMtrt 
te  adfutl^  niarkla«  tiii-i  I. :  II,  rlnrkiAck ;  l\  iMtfenl  ymtm  vpM  ■faloh  tradaK  tt 
,MMn«HllH  ft ttui  1 1  iif  I  ml  ■ftii  r>l>lilt  1 


Mf'<«Mn*i«t 


228 

In  Fick'«  fprine  Diiini>iiiel<T  (Fig.  78),  in  whii-Ii  titc  invrcMo  of  prcMUtv 
unfolil*  a  cunofl  iipriuK  iiml  mi  movt»  n  hver,  the  inrTtia  »  much  Ivm,  uul 
MtiafiuiUinr  tmcingit  may  be  Uikcn  l>r  \hif  iiiiitriimettt.  Oilier  inetrumoaU 
bsve  aIko  men  cl«vU«(l  tor  roounJing  ihc  spocinl  characters  of  each  incr 

Pia.il, 


»   AfkcJ-ii 


I-i'i*>  "nuoKii  nnoi  TiiE  Raciji.  aitkut  ur  sum. 
Tba  Tvnioil  curTEd  lluo,  L.glTw  tba  na«]i>EHtiIviiilior««riltiit;  luira  iii«l«iib*n  Uia  Hm^ 
•nol  psiwr  KU  mntloiila*.  Th*  <iitm4  InUmpLcil  Uno  ihuw  Itnr  ittirlanM  (tam  tne  iwottia  In 
aiDO  «<  th*  chlcl  plum  at  the  pulw-WAni,  tIk.  ;g  —  commenMmont  uid  A  eiul  ut  vrawton  of 
wiair.  p.  piCKlicnllc  uoteta.  d.  dlcfoUc  noteb.  C,  ifleniilc  cmi  n,  INMt^kKitlo  nM.  /.  Um 
iM^rMlc  nolcb.   ThtM  BM  «l|ll*liied  tn  Iha  Wxt  lal«  ■>□. 

of  pnaeure  or  of  \h\:  cxiiimeion  of  the  iirterv  which  ii>  the  result  of  lliat 
tneMaaei  The  eiui«8t  sod  nioet  comnmn  method  of  regiaterioK  the  ex[>aiuion 
of  aa  art«rj  is  that  of  simpi)'  bringing  a  light  lever  to  b«ar  on  the  iiut«i()« 
of  111*  artery. 


V. 


f^- 


BI>B  rubber  puiDp,  .. .'  :i  .  i: .  >iiuciiini-nl.  to  |irtircnl*  nsanrl<A"l  <.-iim.iit:  t,f,f.  uv  Icrrn 
nMosiiii  kciiui  tuba,  *t  liiiermb  «1 3)  cm.  ufiubliis:  C.drom  upon  iitJeb  uuliif  Ii  maA»-.  II, 
fliockiwivk  111  rvroUc  itrum.) 


A  lever  s^ially  ailaplcd  to  reconi  a  pitlw  traciiiz  u  called  a  sphygnio- 
granli,  the  iostniRMUit  gcoenlly  comprising  a  itniiill  Iruvolling  tvcordioR 
Mrtace  ou  which  tha  Uver  wrHea.    Thorv  are  many  diflvrvnl  fbmia  of  sphy^ 


THE  PDL9E. 


229 


tMpipb,  bui  llie  g<>tienil  nlnn  of  nnictun^  in  th«  samr.  Fig.  79  ri>pr«KDtfi 
ID  «  duf  runnwtic  form  the  cakuUhI  P^*  of  (he  »phygnio^«pb,  ItDown  ss 
pii4geaa'«  Tum]  Fig.  S2,  Marvy'ii,  which  is  id  moro  corhdod  use].  The 
iainumt  is  gMOrally  n[i{>lt(il  to  tho  nxlinl  iirtrrv  bccniiee  the  ana  offonJa 
•  (■inn[«imp))OTt  {*>  Ibc  Aili'mtii  <>f  tbo  k-Vf-r,  nnd  because  the  position  of 


pm.  t& 


^\/V^AAA/^iAAAAAAAAA/ 


ftiM ravm  na^BM>  st  a Hun or ^JiiT'inoaurnic  Lxnw-plkndMtnicrTalaol  Vem 
^■M*Mtarakiii(*ncOjallClubelnIoiihlchfliUi)Ufan<dbTthoMdd«nMRitwc>(«puia|>.  Tbe 
^■»*«>*  It  mMlllliK  nuu  krA  to  itclu.  u  InJIoUrt  bf  lh«  umn  a*«r  Uip  pninaor  (a*  Bml  neond- 
iQA<lf«lv««i«L  TlMiMM  v«mc>lllnndnwiift<an  thaMinimltorilioieT«nl|iiliiiu7'«m<r« 
■*<telMlB|Ajik  DOnv  litlDvr, ouh  tmoiplQla TtbfMloa  of  wUcti  aceui«i>  1  JO  aeiaBd. ftUowUi* 
^tab*Baa*nn<Hblchl«ul«upbjtb*miT«lnpMl4>lans3a(Tni.orib*tublBc  Tbo««T« 
^■n>MW«<tftoMf>nntbark«dilMkl*nit  of  Um mUm :  tkli  la  tiullcaittl  by  Ue  dtrMiloii  of 
^  ■*•»  II  win  be  obKtTDd  iliai  In  ll»  wan  dtauui  tera  VL  Itic  nOeelod  wan.  tiNT&w  tol  • 
■^MAaumlo  tivpel,  bfoOBiM  nawl  Willi  lh>  |iriinu7  Hun.    iKnni  MaKST.) 

tk  ulfrr,  n«Hr  to  tbe  lurfncc  aii<t  with  tbe  Aipimrt  of  the  radtus  b«lo«r  ao 
ilat  Mlc^iute  prewure  can  be  brought  to  bt-nr  by  the  lover  od  the  artery,  » 
fcrcnble  for  niakine  obwrvatiomt.  It  vuu,  of  cuurao,  be  applictl  to  other 
amritm.  When  ap[iiit)il  to  cIm  radial  ortvrr  lomo  such  tntcing  a»  that 
4mM  in  Fig.  81  in  obliiiiiccl.  At  acb  bcvl  bi-itt  Iho  lever  rises  rapidly  and 
Ami  hiU  mote  gnulually  in  n  Hdc  vrbich  U  more  nr  le»  uneven. 


280 


THE    VASCULAB   MKOQANISM. 


S 140.  Wc  have  now  to  study  the  nnUirc  ivDd  characUrs  of  ihi'  pul««  in 
greater  detail. 

W«  rnny  fnr  at  once,  und  indeed  have  alreadv  incidentally  eccn,  that  llie 
pulse  is  eBSpniinlly  due  to  the  Hction  of  ptiyeical  cuiieeB;  it  is  the  phyHcal 
result  of  the  sudden  injection  of  the  conleote  uf  the  ventricle  intn  the  elxatic 
tubes  called  arteries;  its  more  imporiani  features  may  be  explained  on 
physical  principles  and  may  be  illustrated  by  m«atiB  of  an  artificial  model 
[Fijr.  82], 

If  two  levers  be  placed  on  the  arterial  tubes  of  an  artl6cial  model  Fig. 
61  &a.,  iS".(r.,  one  near  to  the  pump,  and  the  other  near  to  the  peripheral 
reiUtance,  with  a  conuderable  length  of  tubing  Ixiween  them,  and  both 
leireni  be  made  to  write  oa  a  reo<brdiug  surface,  one  iniDiMliiitelv  below  the 
orhvr,  mi  that  their  curves  can  he  more  easily  oomporeil,  the  fullowiug  facts 
muv  be  ob.ierved,  when  the  pump  in  Met  to  work  regularly.  They  an-  i>vrhn[M 
still  better  neeii  if  a  numher  of  levers  be  similarly  arrangeo  nt  ilitlcnmt 
di.ilunc^  from  the  pump  ha  in  Fig.  8.1. 

At  eiieh  »t.rolc<!  »!'  the  pump,  Midi  lever  rises  until  it  rctncbn<  a  maximum 
(Pig.  8.S,  la,  '2ti.  i.-[c.")  and  ihi'u  fall*  again,  thus  d(«cribing  a  curve-  The  file 
is  due  Ui  ihe  i'xpiitiiii<)ii  iif  tin-  part  nf  the  lulio  under  tho  lever,  and  tho  fall 
IM  due  to  that  part  i>f  the  lulw>  n-liiriirng  after  the  expansion  to  its  prc\Hou» 
calibre.  The  curve  in,  thi'refi>re,  the  eurve  of  the  expausioD  (and  relorn)  of 
th«  tube  at  the  point  an  which  the  lever  rests.  We  may  call  it  the  pulse- 
curve.  It  is  obvious  Ihttt  the  expansion  |ins«c«  by  the  lever  in  the  form  of  a 
wave.  At  one  moment  tho  lever  is  at  mt ;  the  tube  beneath  it  is  simply 
distended  to  the  normal  amount  indicative  of  the  mean  prasurc  which  at 
the  tjme  obtaius  in  the  arterial  tubes  of  the  model;  at  tlie  next  moment  the 
pulse  expansion  reachw  the  lever,  and  the  lever  begins  to  rise ;  it  continues 
to  rise  until  the  top  uf  the  wave  reaches  it,  after  which  it  falU  again  undl 
finally  it  comes  to  rest,  the  wave  having  completely  pacsed  by. 

1^.  KL 


/ 


A  sovon  DiKTRxwHUic  i(KrKi»xv(iiTi'H<  riF  t  fruc-wAV*  N«q]ra  ovu  m  Aktuit. 


It  may  perhaps  be  as  well  at  once  to  warn  the  reader  ihut  the  figure  which 
we  call  the  pulse-curre  is  not  a  leprcnonl^ttion  af  the  pulw-wai-e  ilMlf;  it  n 
^mply  a  repieMniation  of  the  movenient»,  up  and  down,  of  the  piece  of  ihp 
wair  of  the  tubing  at  the  spot  on  whieh  the  lever  nste  ijun'n^  M4  linu  that 
the  wave  is  passing  over  that  spot.     We  may  roughly  repreM.'nt  the  wave  in 


ihiiiHiiiii  Pie<  M  in  vrbicb  tho  wnvu «boira  l>r  tho i)i>tt«d  liito  i*  pM«ing 
«MlM  lab*  («D(Mni  in  it  mudilion  of  ruet  hv  the  tliivk  double  lint')  in  Iho 
JiNdloB  fromHbi  C  It  must,  however,  (>e  remeitiberecl  tbnt  tho  irnvo 
itaiSpind  is  a  mueh  aborur  ware  ihao  is  the  pulse-ware  in  reality  (that 
Uk  m  w*  BbBlI  aae.  about  (1  nwtrw  loi^),  i. «.,  oocupia  a  smaller  length 
WtM arterial  airM«ni  from  thv  heart  /f  toward  the  capillariw  C 

Tbe  curre*  below  A*.  1'.  Z  repreaont,  in  a  similarly  <tia{;raiDm8tic  fluhioB, 
iktcorret  deacribed,  durio)*  the  passage  of  lli«  wave,  by  leran  plocttl  on 
ibt  points  1',  y.  t.  At  X  the  j-roiilcr  part  of  the  vrave  has  already  pMoed 
atoUie  lerer,  whi«fa  durinff  its  passage  haa  already  described  tbe  greater 
)Mt  of  its  curve.  sIiovd  by  ibe  thick  line,  and  has  only  now  to  describe  the 
Mall  fan.  Hbown  by  the  <loiied  line.  eornM[M)i)diug  to  the  remainder  of  the 
an*  m>m  Jf  lu //.  At  I'lhe  lev«r  i^  at  the  xuiniuit  of  tbe  ware.  At  JT 
ds  lerer  baa  only  described  u  Hniall  pun  of  the  tieKinning  of  tbe  wave,  vis., 
bm  C  to  X.  tbe  rest  of  the  curve,  us  sliown  by  the  dotted  line,  liarin?  yet  to 
hid«eribed. 

Bvi  to  retora  to  tbe  OMisideraticm  of  Via.  8^. 

t  liL  The  rise  of  each  lever  i*  soiitcwliat  sudden,  but  the  fall  is  more 
psdual,  and  is  generally  murkei!  with  Home  irrcfrularititra  whic^h  we  shall 
niv  pnacDily.  The  Hmc  u  *tiil<U-ti  bcn'Aiii'C  tho  sharp  iitrDlce  of  the  pump 
— Uwily  drives  a  (jnantity  uf  tliiiil  into  the  tubing  and  «•>  »ttd>l(tiilv  expands 
itilabe;  tlte  fall  u  more  t;nidiinl  because  the  elastic  rutt-tion  of  the  walla 
rfiha  tab*,  wbic-b  htin-j*  nbont  the  return  of  the  tube  to  its  foroMir  calibre 
lAirlW  expanding  jxtwcr  of  the  pump  has  ceased,  is  more  gradual  in  its 
BrtiaD. 

Tbaa  Aaturai,  the  Rud<lenn<M  nf  the  rise  or  up-etroke.  and  the  more 
pailaal  slope  of  the  fall  or  dnwn-Hlroke,  arw  seen  ako  in  natural  pulse-curves 
Iskearrooi  living  arteries  (Figs.81, 85. etc.  1. 
Uied,  lira  didereuee  between  the  uf>-«lri>ke 
nri  ibe  down-strvike  is  even  more  marked 
ia  ibr  latter  than  in  the  former,  the  (k-livery 
(/ blood  iVom  the  veotride  being  more  rapid 
Ikia  tbe  iMue  of  water  from  a  pump  an  onli- 
Birilr  worked. 

It  may  here  be  noted  tliai  ibe  imtual  lixe 
<f  fb«  curve,  that  k  the  amount  uf  exciiniion 
<f  ibi  lover,  ilcpeuibi  in  part  (an  does  aluo  to 
Sgrat  axtent  Ui«  form  of  tlte  curve)  on  the 
laawil  of  prcMure  cxcrtiNl  by  the  lever  on 
Ik  labe.  ir  ibe  lover  only  juHt  tonrhcs  the 
tub*  ID  lu  upaoded  aute,  the  rim  will  be 
NigBMauit.  If.  iMi  tho  other  hand,  the 
bnr  ba  praned  down  two  firmly,  the  tube 
haath  will  not  bt^  able  to  cx'paDd  as  it. 
Hlaiise  wovld.  and  the  rite  of  the  lever 
■fli  be  proportionately  diniiiiUhed.  There 
btcertun  prasure  which  must  be  exerted 
hr  tbe  lerer  on  tbe  tube,  tbe  exact  amount 
■bjRsdtng  on  tbe  expansive  power  of  the 
taUifand  on  the  pressure  exerted  by  tlie  fluid  in  the  tube,  in  order  that  tbe 
■ndig  nay  be  best  marked.  This  is  shown  in  Fig.  M5  in  which  are  given 
thne  trwdngs  taken  from  the  same  radial  artery  witli  the  Kauie  inatruraeat; 
in  Iba  lower  curve  the  prewtire  of  tlie  lever  is  too  great,  in  the  upper  enrve 
H»  mall,  to  bring  out  the  i-haniut«ni  seen  meat  distinctly  in  tJie  middle 
<WTt  with  a  medium  presaure. 


PM.  Ul 


JltL^^^ 


Pci«i  TsiaiAH  i-Bos  inn  >4>U  R^ 
lUAt,    AsTUr    rxpKi     IHrnman 

I'UaHIKM  or  TBI    LlTU. 

iTbB  Icltenmni  sxiiUnsd  In  ■  IsMr 
■■ft  of  Uio  (Ml.) 


282 


THE    VASCULAR  )ISCBA^'IS1I. 


Fia  ««. 


Fro.  M. 


li  142.  It  will  be  obttrred  tliat  ia  Tig.  83,  eurre  I.,  wliteb  is  nearer 
|iiim{t.  tiaes  biglier,  and  rises  more  rupinly  than  curve  II.,  wbiob  ia  fiit 
away  from  Ibe  )Hmi{> ;  tbal  h  t(>  sny,  al  the  lever  Airther  awnr  froiD  ifi? 
pump,  tlie  expautiioii  U  Uta  hdiI  take*  place  miire  tloirljr  ibmn  at  tbo  lever 
Dearer  the  pump.  Simil»r]}-  in  curve  IV.  tbe  rise  is  sUll  IcM,  itnd  takes 
place  still  lew  rapidly  limn  in  11.,  and  tbc  wmc  cbange  is  teen  Ktill  miir« 
marked  in  V.  a*  conipnn'd  «ilti  IV.  ]ii  fuel,  if  a  number  of  Irvi-rw  «i-re 
plae«d  at  ciuul  diKtaiii-es  nioiig  tli<-  arterial  tubing  of  tbc  model  and  the 
model  were  vrorklni^  profNTlv.  with  iiu  iiili'ijiiiilp  jHTiphcnil  n.wlam'o,  w« 
mi^bt  irar'f  out  step  hy  step  bow  the  rxpimiiioii,  m*  it  tnivi-lleil  nhmg  the 
tube,  gnt  IcH  niid  Ici>e  in  amounl  and  itl  lh<?  «enie  tira*^  Ivcciime  more  gradual 
in  Its  development,  Ihc  curve  becoming  lower  and  more  flattened  out,  until 
in  Uic  nciglitiorhood  of  the  artificial  capillaries  there  wni>  bnrdly  iinr  trac«S 
of  it  left.  In  other  words,  we  might  trace  out  step  by  et«p  tbe  graJua]  dia- 
apmaranco  of  the  pulse. 

The  same  changes,  the  aame  gradual  lowering  and  Hattening  of  the  curv* 
may  be  seen  iu  natunil  piil^e'trnciDgs,  na  for  insunce  in  Pig.  im,  which  it  a 

a  tracing  from  the  dorsalia  pedi*  arlenr, 
ooiupared  with  the  tracing  from  the  radial 
artery.  Fig.  85.  taken  from  the  ean>e  indi- 
viduiil  with  the  same  tnalmnieut  on  the 
same  ocenuon.  litis  feature  in,  of  course, 
not  ubvious  in  all  puls^ourves  taken  from 
diflerenl  iudividuals  with  diHerent  iti^lni- 
ments  and  under  varied  circumtitauc-es; 
but  if  a  series  of  curves  from  diderent 
Brtcric*  were  carefully  tukt«  under  tlie  same  conditions  it  nouhl  Iw  found 
that  the  notlic  tracing  In  higli*^r  and  more  sudden  thiin  the  carotid  tracing, 
which,  agnin,  is  higher  and  more  sudden  than  ilic  mdial  tracing— the  tibial 
trat^'ing  being  in  turn  »till  lower  and  more  flnttcne<l.  The  pulse-cnrvc  diw 
ont  hy  becoming  lower  and  lower  and  man?  and  more  flntlenod  out. 

And  a  little  consideration  will  show  us  that  this  niual  bo  so.  Tbe  systole 
of  the  ventricle  driven  a  quantity  of  blood  into  the  already  full  aorta.  Tbe 
sudden  injection  of  thi*  ijunnliiy  of  blood  cspauds  the  portion  of  tbe  aorta 
next  to  me  heart,  the  part  immediately  ailjaccnl  to  the  semilunar  valves 
beginning  to  expand  lirst,  and  the  expnneiou  traTclling  ihenoe  on  to  tbe  end 
of  this  portion.  In  ihetsme  war  the  expansion  travels  on  from  this  portion 
through  all  the  sueoeeding  portions  of  tbe  arterial  system.  For  the  total 
expansion  required  to  make  room  fi>r  the  new  quantity  of  blood  is  not  pro- 
viaed  by  that  jiorlion  atone  of  the  aorta  into  which  tbe  blood  is  aelually 
received:  it  is  supplied  by  the  whole  arterial  system;  the  old  ijunnlity  of 
blood  which  is  replaced  by  the  new  in  this  first  |>ortion  has  to  find  mom  for 
itself  in  tbe  reet  of  tbe  nrterinl  B|Mice.  As  the  expansion  travels  onward, 
however,  the  ijiergntc  of  pressure  which  each  portion  transmits  in  tbe  suc> 
ceeding  portion  will  be  less  than  that  which  it  received  thtm  the  nrecediug 
porliou.  For  the  whole  increase  of  prt^uure  due  to  llie  systole  of  the  ven- 
tricle baa  to  be  distributed  over  the  whule  of  the  arterial  system  ;  tlie  general 
mean  arterial  preMura  ia.  as  we  have  seeu,  maintained  by  repeated  sysiolof. 
and  any  one  systole  baa  to  make  il^  euutriliutifin  to  that  mean  prcMore :  (lie 
increase  of  pressure  which  starts  l>om  the  ventricle  nmst,  therefore.  Icavc 
behind  at  each  stage  of  its  progrcM  a  fraction  of  itself;  that  is  to  Htr.  the 
expansion  is  continually  growing  lew,  as  the  pul.w  travels  from  tbc  neart 
to  Uk  capillaries.  Moreovtir,  wbde  the  expunnioi]  of  tbe  norta  next  to  the 
BmK  is.  so  to  speak,  the  direct  etfectof  thvM-ntolcof  the  ventricle,  the  expan- 
sion of  tlw  more  diilaul  artery  i*  thu  cDivt  of  the  systole  transmitted  by  tbe 


'  the  elastic  reaclion  of  the  arterial  trncl  betwMU  Ihe  bmrt  am)  the 
auawnery:  utd  uaet  this  eladk  mftimi  in  «Iuwer  in  i)i-\-eloiin)eiit  tlian 
lb*  kUmI  antole,  ibe  ezpanaion  of  tlie  mmv  dixtant  bhit}'  in  tluwrr  lliau 
tkM  «f  1^  lorta,  iIm  up^vlroke  of  the  ptibe-curvc  i»  In*  MiddcD,  udJ  the 
«W«  palK-«urT«  is  niure  Hatti-iiisi. 

n*  object  of  tbe  mtiilc  b  tn  mpplr  a  fiinlribiili'>n  to  lliv  mcBa  prcaHir*, 
uJlb*  pubebui  cwcillntioci  aborc  aiiil  hi-lon  thiit  ineiiii  prcfRun — im  OMil- 
lUiMwIiicIa  (liininulm  from  tlic  hnrt  onminis  hiding  diimprd  by  the  elARtlc 
mill  «f  til*  artrriiv,  ■nd  po,  Uttlv  l>y  little,  colt Tcrtcd  itita  mvaa  pmaure 
nXil  ia  tli«  cKpillnms  llic  ibmu  prasRura  alone  ramniiM — the  oenllatioiw 
ianne  A'amppt^mi. 

(143.  If  tn  tikc  mo<lel  the  {Hiints  of  ibo  two  lerere  at  dilli-nMil  di»tniir«» 
ftm  ibr  pump  bv  niaced  cxiittly  one  under  the  other  ud  the  rceordJng  eiir- 
fctt,il  i«  obviuuB  tnat,  the  levcre  being  alike  cxeept  for  their  poeilion  on  th« 
laht.ur  difitreiK'e  id  time  between  tlie  movenienta  of  the  two  lerera  will  be 
^•n  bv  ui  interval  between  the  beginuin;^  of  the  curves  they  deiwribe,  the 
KMding  surface  bHng  made  to  travel  suliicieiilly  rapidly. 

If  the  novcmeuta  of  the  lirn  levers  be  thus  compared,  it  will  be  tffio  that 
6t  far  lever  (Fijij.  sy  II.  i  oommenc-es  later  than  the  near  one  (Kii;.  So  I.) ; 
dc  further  a|)art  ih«  two  levers  are,  the  greater  is  the  interval  in  time 
\tdina  their  curves.  Compare  the  series  I.  to  VI.  (Fi{[.  K3).  This  nieatift 
iiai  ibt^  wave  of  espausioa,  (he  pulse-wave  lakes  some  timt;  to  tmvcl  along 
l&(Ub&  In  ilw  same  way  it  would  be  found  that  the  rise  of  tlie  near  lever 
bnaaone  ftaetion  of  a  sccuml  itHcr  the  .iirukc  of  the  pump. 

The  veloci^  with  which  the  »u]Hi-wavf  tnivcis  depcuil*  chiofly  on  the 
uwunt  of  risidily  poaieMml  l>y  Itie  tubing.  Thv  morv  extensible  (with  cor- 
npOodlM  Mutio  reactinuj  tlio  lube,  the  slower  i*  the  nave ;  tho  more  ridd 
lkttnbebeeam«i>.tl)C  ftster  tbcwnve  travels;  in  a  perfectly  rigid  tul>r,  whnl 
btWflaftic  lube  would  Itc  iIk  pulse,  beeomes  a  more  Ehoek  travelling  with 
nrrgTMl  rmpidity.  The  width  of  the  tube  is  of  much  less  influence,  though 
■RMttng  to  MiDG  observere  the  wave  travels  more  ilowlv  in  the  wider  tuliw. 
The  rate  at  which  the  normal  (mke-wsve  travels  in  tKe  human  body  has 
kwn  vaHoti'ly  estimated  at  from  10  to  5  metrra  per  Mcond.  In  all  proba- 
Ully  the  lower  estimate  is  the  more  correct  oue :  bat  it  must  be  re«ieiiib«n(l 
thit  (he  nilo  may  vary  verv  cooaiderably  under  iliflerent  condiliona.  Aooord- 
ilgloall  observers  the  velocity  of  the  wave  in  pnariinii  from  the  (jroin  ta  tlie 
bat  is  gTftater  than  in  na^ioK  from  the  axilla  In  the  wrist  1 1!  metres  againat 
i mttnt).  This  U  proiwbly  due  t.i  tin-  fact  that  the  lonionil  artery  with  ila 
taBehw  ia  more  ri};id  than  thu  axillurA-  and  in  bnmchi-^  So  also  in  the 
I  of  ohildreu,  ll>e  wave  traveU  mor>e  slowly  than  in  the  more  ri^d 
I  of  the  adall.  'I1i«  velocity  in  al»o  increiued  by  circuni;)tAiicea  which 
baijrtta  and  decretued  by  thinv  which  Icmiii  the  mean  nncrtal  preaanre, 
met  with  incmsiiii;  urcwun;  the  arturiiil  witll.t  become  more,  and  with 
dldRiilliog  pTBMure,  Itm  rifpd.  Pnitiahly.  aUn,  the  velocity  t>f  lh<-  ]>tihie- 
•nv (lepeD<ls OQ  ooiMlition»«f  thearlfrinl  wall*,  which  wecnnitot  ndcciunttly 
^Mribt  u  mere  difTert'im*  in  rigiililr.  In  exiierimt-nliug  with  artificial 
it  ia  found  that  different  c|tuilit>cs  of  Indui-rubbar  give  rno  to  very 

mulu.  ' 

I  muM  bo  ulccn  not  to  oonfmind  the  progms  of  ibe  pnlte-wnve^i.  e., 
rf  tha  fXpanioD  of  the  art^rrial  wal  Is.  with  I  he  actual  onward  morenu-iit  of 
lb  btum)  iunl^  The  pitW-wave  travels  over  llic  moving  blood  somewhat  as  n 
npidly  moving  nattinil  nave  travels  alone  a  iluggi»hly  flowing  river.  ThiM 
iiila  tfa«  velocity  of  the  pu)se>-wave  is  6  or  powibly  even  10  metre*  per 
1,  that  of  tho  current  of  the  bhKid  is  not  more  than  luilf  a  metrv  per 
I  vren  iii  (he  lar^  arteries,  and  is  still  Ices  in  the  smaller  ooei. 


234 


THK    VAflCt7I.AB    VKCllASlt 


^  144.  Referring  ojritin  Im  the  ntulinn  a'ivcn  above  luit  to  r«i;nn]  lUo  pulse- 
curve  as  a  picture  af  the  puliK-wavv,  we  miiv  new  sdi)  that  llio  imlMr-wttve  b 
«r  very  conaidentble  U-tijcili.  It'  tv'i;  know  how  luii)[  it  iakir>  lor  the  |>ulse- 
tritve  tu  ptaa  ov«r  iidv  [H>iiil  in  thii  nriorit^  luid  huw  fam  il  i«  travel  I  i  tig.  w« 
can  euMJIy  calculate  the  k-nglli  nf  the  wave:.  In  an  (inliitarr  jiuUe-curve  the 
arlerj',  uwiiig  tn  iho  Hlnw  return,  i»  nrrn  nut  to  rc;(aia  tliu  valilirc  which  it  luul 
before  the  nxrianbtion,  until  jii»t  iu>  ihc  wxt  vxpauvion  t)e^iis — tliat  i»  to  «j, 
the  pubc-wavv  tiikm  the  whole  time  of  n  uunlinc  cycle,  vii. :  -fisiht  seoond  to 
paw  l>y  ihtj  kvi-r.  Taking  the  velocity  "f  llie  inil»-wnvc  a*  6  metere  j>w 
■econd  Uie  le4>gth  ofthc  wave  will  be  /slhs  uf  6  moirea — or  nearly  A  metraa. 
And  even  if  we  took  a  »iaaller  estimate,  by  enppo«ine  that  t4)«  real  ftzpaa- 
flion  nod  return  of  the  art«ry  at  any  point  Inok  much  lew  time.  t*y  tV^i' 
Mcnnd,  the  length  of  the  piil«e-wave  would  still  be  more  than  'Z  nieLn».  But 
even  in  the  tallest  man  the  caitillarieH  furthest  from  the  beni't,  thoKi  in  the 
ti|w  of  the  toes,  are  not  '2  melrefl  distant  from  the  heart.  In  other  woril^  the 
Mlgtb  of  the  pul»e-wavL-  is  much  greater  than  the  whole  length  of  the  arte- 
risTeyBtem,  bo  that  the  beginning  of  each  wave  has  become  lust  in  the  Hmnll 
arteries  and  caiiiltariea  some  time  before  the  end  of  it  has  finally  passed  away 
from  the  beginning  of  the  anrliu 

We  muBl  now  n^tuni  to  the  conaiileration  of  certain  special  feaiiires  in  the 
pulse,  which  from  the  indication)!  they  give  or  auggeat  of  the  eundilion  of  llie 
vascular  system  are  ol\uu  of  eri^at  iniereat. 

049.  Ditrotism.  In  nearlr  all  pulite-tracinga,  tbe  curreof  tlw  expannoD 
anil  recoil  of  the  artery  im  broken  by  lito,  tiiree,  or  several  anialler  eleraliona 
and  deprea«ion»;  «ecoiidurv  wavin  are  imposed  ujun  the  nindnmeuta)  or 
primary  wav&    In  the  spWgmogruphic  tracing  fVntn  the  carotid,  i-lg.  87, 

no.  a. 


rvi««.TNACi)iw  raoK  C*aonii  Aktieiit  or  IIultiiv  Mas  (ftom  HonW. 
a,  DDmnwoconiMI  of  upuulon  oTBrtcrr.   J,  lununlt  oftlieDninte.   C,  dlcnU;  teconOur  waT«, 
Aii^dluMlaMiMadaTT war*: p.Qouh prtetdlnf tliliL   D.'upnodlimiMaailuy unTa.  TtMimtva 
■bnali  llMlof  ■  nndnpDHt  with  un  daulile  TlbnUon*  Id  B  Mooiiil, 

and  in  manv  of  ibo  other  tracings  given,  thcM  cecimdary  elevations  ar« 
tuarke^l,  as  /{,  f,  />.  When  one  such  seoondarv  elevation  only  is  con^icu- 
ouR,  so  that  the  piiUe-eurve  presents  two  notabto  creets  only,  iha  primary 
creit  and  a  aeoondary  one,  the  nuUe  U  said  to  be  "dicrotic";  wnen  two 
wcoodary  creats  are  prominent,  tne  pu  Ise  is  often  called  "  tricrotic  "  ;  where 
Mrcral,  "  polycrotic'  As  a  general  rule,  the  secondary  el evatinns  appear 
only  on  the  deacending  Hnib  of  the  primary  wave  as  in  mml  of  the  curves 
given,  and  the  curve  i*  then  spoken  of  aa  "  katacrotic."  Sameliine»,  how- 
ever, the  Srtl  cl«vniion  or  cns<t  i*  not  the  highest  but  appear)  on  Ute  aicend- 
tng  portion  of  the  main  curve;  Hiii'h  a  curve  in  apakeu  of  at  "aDacrotio." 

or  tbeae  aeoondary  elevations  the  moM  freiuent,  eonspicuoua,  and  impor- 


THE    PULSK. 


285 


iMt  b  ih*  one  which  uppeara  w>iii«  nj  down  on  the  dewmding  ltntl>,  nnd  !• 
Mrbd  C  on  Fix-  ^~  itnd  an  mcMt  uf  the  curvw  hera  given.  It  in  nion:  or 
luiJiitiiiiHr  viiuble  on  all  sphysmogmmf,  and  amy  be  mnmi  in  (Imjuv  of  the 
MTU  ■*  well  ss  of  oUier  itrtcrica.  SomeliiDen  it  is  m  slight  «<  to  be  hnr<lly 
_i[liiilJhlr  U  other  timos  it  muv  be  so  marked  «a  to  givp  rim  to  a  roally 
■Ut  |iulM(Pig.  89),  !.<;,  ■  puW  which  oao  )m  fHt  as  dotible  by  the 


f\. 


n^m. 


Vta 


L 


M-  M-Aitnii>Tii^Vaii.H'Mii 41-11  Thvctiu  ri-'U  nil  Mcwii!!!)  AaltL    lAniurtaa.) 
fta  ■ -T*I>  U*4liD  or  MlBKIl' tlll-IKITBN  I-I  It  •IIIIIL  Puw  OT  Man,     «TfTlloi<l  (ClVf,) 

hfif ;  httMre  it  has  been  called  the  tliervtu^  ok'vutiiiii  or  the  dicrotic  ware, 

t  Dotrh  pr(>cr>]ing  the  clevntioii  hv'we  spoken  of  as  the  "dicrotic  notch." 

Abfr  it   nor  any  other  secondsry  mvatioDi  can  lie  raawnbed  in  the 

Mitft  of  blood- presBu re  taken  with  a  niaimmeter.     Thi:*  mnr  l">  rxpliiitied, 

iVt  have  said  $  13!},  by  the  fact  that  the  tnovcincnis  of  thu  incrcunr 

Ama  are  too  BlufEgisb  to  reproduce  theee  liner  vanutione  ;  but  dicmtiim  t* 

in  compicuoiM  by  its  ahMOce  in  the  tracin){«  ^vcn  by  mora  del iceloty 

'■^fpnttve  iiMtmmeiila.     Moreover,  when  the  normal  piilm?  i»  fcU  by  the 

V.  Ridsl  persons  BikI  theiuselvei  imabk-  !■>  deloel  any  dicrollnm.     But 

it  (lo««  n-allv  exirii  iu  the  nunnikl  pulse  is  ahonn  by  the  ftu-t  thai  it 

toparp  in  a  iaa*t  unmbdukahlt^  manner  in  the  tracing  oblained  bv  allowing 

nt  UojI  to  afMirt  dtrm-tly  fr»in  an  ojiL-ncd  tmall  artery,  itucb  as  tKe  dorsalia 

,  friv,  upon  a  rrconling  lurlacc 

Um  runstwit  and  consplcuouti  than  the  dicrottP  wrav4>,  but  vet  apfteering 
'*  I  BMt  •phvgR>ogr*inR,  ix  an  devntiDn  which  appear*  hi^lier  up  on  this 
jBoiIine  hmh  of  the  main  nave ;  il  in  markeal  R  in  Fig  87,  and  on  several 
rda  other  ciini-a*.  and  i*  frequently  called  the  pre-dipro(ie  wave ;  it  may 
tkuBW  very  nromiaent.  Somctiinoa  other  atoondary  wavr*.  uneii  called 
"fatdienitic. '  are  »eeii  following  the  dicrotic  wave,  a*  iit  D  in  Fig.  ^7,  and 
■■elher  rurres;  but  thcM  aronot  ofttn  pmH'nl,  snd  imuully,  nven  when 
pMnl,  iDPomptFU04i». 

When  tracing*  are  taken  from  mveral  nrlcriea,  or  Irom  tlie  same  artery 
tadir  dtfltont  coDititionn  of  the  body,  thcM  aeoondnrT  waves  are  found  l» 
nij  Terr  oMHiderably,  giving  rite  to  many  dwracteristic  ibrma  of  pulse- 
eirrr.  Were  we  able  with  certainty  lo  trace  hnck  the  wveral  featurcaof  the 
111  their  rmpective  uiuses ;  an  adequate  examination  of  sphygno* 
hie  tracings  would  undoubtedly  disclwe  much  valualde  infornuitiflti 
cnuiig  the  contlitiou  of  the  body  presenling  ihem.  Unfortunately,  the 
pnU«n  of  the  origin  of  these  teooDdiiry  waves  is  a  n>oet  dilBcult  and'  oin- 
fbienv:  so  mueh  ao,  that  the  detailed  interpretation  of  a  sphygmograpbic 
Inaojt  b  still  in  n»<itit  coses  extremely  uDoertain. 

\  m.  The  chief  intenst  attaches  tu  the  nature  and  meaning  of  lite  dicrotic 
•atn  In  general,  the  main  cotidiiiuns  favoring  dicroiimu  are  (1)  a  highly 
■  niwilili  and  elastic  anenal  null,  (2)  s\  cuminiraiivcly  lnw  mean  pressure, 
letfing  the  oxtensilde  and  eluAlic  reactimi  of  the  arterial  wall  fre^  M>opo  to 
act  aiM  (3)  ■  sufficiently  vigorous  and  sufficiently  rapid  Uroke  of  the  ren- 
Hiek.  'The  developmait  of  the  dicrotic  wave  niay  prol*ably  be  explained  as 
Mloin: 


266 


TillC    VASCtTLAit    UKCltAXISM. 


At  eiicli  heat  the  lime  durbijc  which  Uic  coiireuu  of  the  left  v«>Dlr 
iDJei'leil  iulo  tbe  aurta  is,  ai  ive  have  neeti  (^  I3ii),  verr  hri«r.  The  ex]Mii- 
MOD  of  the  aorla  u  very  ■ik1iI«u,  tunl  thu  oenMliou  of  tnat  cxpannoa  U  aln 
very  wuddeii. 

Now,  wh«n  fttiul  Li  b<,^iig  driven  with  own  >  Rtciiilv  prrK^iire  through  an 
^Ulie  tube  or  it  .■'viitcim  iif  diutic  tiilMW,  Icvora  plucoii  oil  thi-  lubo  will 
detcribc  ctirvc  ludiniting  vnriiitionsin  Iho  (linmc'Ierof  tholtibo,)f  iheinHow 
Into  the  tube  be  Hudiluiily  slo[i|io<l,  lu  by  Hhnrply  turning  a  stop-cock ;  and  a 
cotnparisoR  of  IcveTS  puiood  at  JiffOTeiil  distancea  from  the  stop-cock  will 
show  that  thcxe  vanatioas  of  dtamel«r  travel  donm  tJic  ttibo  from  the  stop- 
cock ill  the  form  of  waves.  The  lever  near  t)i«  stop-cock  will  first  of  all  (all. 
but  Bpeodilr  begin  to  rise  again,  and  this  subsequenl  rise  will  be  followed  by 
another  thil,  afler  which  there  tnnj  be  one  or  more  siiccceding  rises  and  fnllft— • 
that  is,  oscilliitions — with  decreasing  amplitTido),  until  the  fluid  comes  to  rest. 
The  levers  further  from  the  ston-cock  will  describe  curves,  similar  to  the 
above  in  ibrm  but  of  lesa  amplitude,  aud  it  will  be  found  that  tbeee  occur 
nmewhat  later  in  time,  the  more  ^  the  furlher  the  lever  is  from  tbe  stop- 
cock. UbviouHly  these  waves  are  generated  at  or  near  tbe  stop-tywk,  am) 
tnvel  thence  along  the  tubing. 

We  may  infer  that  nt  each  licat  of  the  heart  aimilur  warea  would  be 
frenerated  at  the  rmit  nf  the  uorta  u[>on  the  xudilen  enuuiliou  of  tlie  How  from 
tbe  ventricle,  and  would  travel  theuee  along  the  elantic  arierie-.  Tbe  fai^ 
liiat  each  beat  in  rapidly  nucci-eded  hy  another,  ntiil  that  the  How  which  *ud- 
denly  ceases  ia  aliu,  by  the  uutiire  of  the  ventricular  stroke,  siiddvnly  mt' 
ented,  may  render  tlie  wavia  more  complicaUid,  hut  will  not  changv  loeir 
«wentinl  nature. 

The  exact  intenirelatinn  of  the  generation  of  th<'«o  waves  b  [wrhaiM  not 
without  difficulty,  but  two  factors  seem  of  especial  importance.  In  the  firtt 
place,  as  we  have  already  more  than  once  srtid,  when  a  rapid  flow  is  suddenlr 
stopped  a  negative  pressure  makes  its  appearance  behiud  the  column  of  fluia. 
In  n  rigid  tube  this  simply  lcn<ts  to  a  reflux  of  Huid.  In  an  elastic  tube  its 
elleci^  are  complicated  i>v  the  second  factor,  the  elastic  action  aud  inertia  of 
the  walls  of  the  tube.  Upon  the  sudden  ceMuiliou  of  the  tluw,  the  expanMoii 
of  the  tube,  or  as  we  may  nt  once  say.  of  the  aorta,  ceases,  the  vensel  beg;iiia 
to  shrink,  and  the  lever  placed  on  it»  waliii.  tut  from  .1  onward  in  tite  pube- 
curre.  This  abrinking  i«  in  part  due  to  the  etastii-  reaction  of  the  walU  of 
U)e  aorta,  but  la  inereaaed  by  the  "  suotion  "  action  of  (be  nirgative  preM^I 
apokea  uf  above.  In  thus  shrinking,  however,  under  theac  cumbin*^  cwimH 
tne  aorta,  through  the  Inertia  of  iltt  walU,  nvenihoots  the  mark,  it  in  carrietl 
beyond  ita  imtural  calibre — i.e..  the  diameter  it  wuuld  ]>(MU»ti  if  leli  to  itcclf 
with  (ho  prcMure  innide  am)  uulcide  euual ;  it  i<hrink;i  ttiu  much,  and  ooitae- 
•e<)ueii(lr  hcciiu  ngnin  Ut  expand.  This  sucomlnry  expansion  (taking  for 
simplicity  sake  a  pulac-curve  lu  which  the  so  called  prc-dicrotic  wave.  B,  is 
ftbaoat  or  inconspicuous)  ciui<w«  the  necoiidarv  riw  of  the  lover  up  (o  C— tbat 
IB,  the  dicrotic  nse.  In  thus  cxgnindriig  again,  tlie  aorta  lends  to  draw  bock 
toward  the  heart  the  column  of  blood  which  by  loss  of  momentum  had  come 
to  rest,  or,  indc«d,  under  the  intlucncB  of  the  negative  prcasuie  s))okeD  of 
above,  was  already  undergoing  a  roHiix.  In  this  secondary  expansion,  more- 
over, tlie  aorta  is  oy  tbe  inertia  of  its  walla,  aided  by  that  of  the  blood,  again 
carried,  so  to  speak,  beyond  its  mark,  so  that  no  sooner  has  it  become  ex- 
panded and  filled  with  iluid  to  a  uertain  extent  than  it  again  begins  to  shrink 
ae  from  Oooward.  And  thi»  .shrinking  may  in  a  siintJiir  luantier  to  the  firvl 
be  followed  by  a  furllier  expansion  and  sbriukiug.  giving  rise  to  a  poctt- 
dicrotic  wave,  or  it  may  be  to  poet-dicndic  wavei.  And  the  »ucoeMn\-o 
changes  thus  inauKurate<l  at  the  root  of  (be  aiirta  travel  na  »>  mniij 


TOE  PCL9K. 


237 


riH|(tte  utorUI  ayatvin.  iliminlshiiig  H  tbrr  go.  It  irilt  lie  olwcrvvd  Uinl 
brtSFJavclotmient  uf  the«-  wave*  n  certain  quality  in  lh«  walk  of  Um  tubing 
■  iwrrwary.  Ttu>  tnlw  niiul  ItPHichaspnanPwrawIiviint  mtauop«n  liiiDen; 
tkrvaUi  niMt  be  '>f  Huch  a  kind  that  tii«  tube  romniiw  open  wben  emptv — 
i  t,  ■bea  the  atiiuwph«rlc  prcautv  i«  equal  inxiilo  and  outside — «K  tlint  w)i«o 
il  thriBkl  too  mtlcli  it  expands  eigain  in  stiiving  li>  rc-;!Ain  its  natural  calibre. 
1k>  *e  bavt*  Men  to  be  a  cbaracteristic  oF  the  arteries.  A  (x>]Iapaib)e  liitie 
•f  lUl  BWQibraiie  will  not  »hi>w  the  pbetionicna;  Hiich  a  tube  n'beii  ilii-  iiu>j>- 
Mcfc  ■>  tarunl  i-ollaieea  and  ciiipttea  iifeif.  conlinuiD^  to  be  collaftfieil  witli- 
gd  >iiT  diort  tu  ex  iMud  aj{ain. 

Is  llie  above  ex  plaitaliun  no  nM-ntion  baa  been  made  of  the  cloaiue  of  tlie 
•MiluDar  valvro ;  we  almll  Imve  lo  >.\vak  of  these  a  little  later  on  in  refer- 
ni|  lo  the  pr^v^licnitiv  wave,  ami  biiall  M'e  tliui,  nmler  the  view  w<-  have  juat 
|i(*ii,  tho  clgting  uf  lite  fieDiilitnar  valves  is  to  be  regunli-d  rather  a»  the 
tttCt  tlMn  iho  cauw  of  ibc  dii-mtie  nave.  Manjr  auihom,  however,  givo  no 
hRnntation  of  th«  dicrnttc  wave  diflerent  from  tJiat  deliiitol  nbiive.  Thus, 
kbliabl  tlifll  ibo  primarv  sbrinlciiig  I'runi  A  onward,  being  brouglit  to  hear 
MlWcolamn  of  blood  already  come  to  nat,  in  face  of  the  great  prcwure  id 
fiwl.driim  the  blmid  Imck  ngainst  the  *eniiliinar  valrcw.  iliiin  cimiug  them, 
ni  that  the  imiMCt  of  tlie  nilunin  of  IiIihhI  ajruiiist  ihn  valves  tttmrie  a  new 
nn  of  cxpanawD,  which  relnrorcintr  ihn  natural  tiniduiicy  of  the  ehutU- 
nib  to  exgiand  again  after  thi-ir  pritmirv  nbriuktng,  pniduen  the  dicrolie 
■m  C  On  this  vi*-w,  it  i»  lli"  blowl  drivi-n  baek  from  ihr  valves  which 
•ifMik  the  arti-ry ;  on  iIm-  view  given  nlmvc,  it  is  iho  oxpaiiding  artery  which 
4i»s  tlic  hI'X"!  twck  tinrnrd  ihr  vnlnw, 

Uonover.  quite  other  virn»  hnvc  been  or  arc  held  cuncorning  this  dicrotic 
nra  Art^>^dinK  to  many  nulh'irv,  il  is  what  i*  ciillcil  a  "  reflected  "  wave. 
Tbw.*)ien  the  lube  of  the  artitieial  luodcl  bearing  two  levers  is  blocked  just 
kinad  ibeiar  lerer,  lbs  primary  wave  beeen  tobeaooompanied  byasccoiMl 
aant  which  al  the  &r  kver  b  seen  doee  to,  and  often  fiiaed  into,  the  primary 
ant  (Fig.  f*3,  \'I.  <■'),  hut  al  the  near  lever  is  at  some  distance  from  it 
(Pi|.83,l.  i').  lieiu^  the  further  from  il  the  longer  tlie  interval  b«tnt«n  the 
mm  aaij  the  bli>ck  in  the  tuht?.  The  second  wave  is  evidently  the  primary 
••*«  rtAeded  at  the  block  and  imvelling  backward  toward  the  pimip.  ft 
tkm.  of  eouiae,  (MWCa  the  far  lever  liefure  the  near  one.  And  it  has  been 
m^Kii  that  the  dicrotic  wave  nf  the  tmliw  is  really  audi  a  reflected  wave, 
Mulnl  riilM-r  St  tlw  iDiniite  arierius  and  i-apillariea,  or  at  the  points  of  bifiir- 
Bttiwof  the  krger  arterie*.  and  liavidling  backward  to  the  aoilA.  Dot  if 
lib  mr^tba  c»V.  the  ilistanci^  l>ctwe(-n  the  primary  erMt  and  the  dicnitic 
<pM  oaglit  to  be  Ion  in  arteriei  more  diitunt  from  Ihan  in  those  nearer  to 
ibtbmrt,  JDSt  M  in  tbo  Hrliltcial  •cbenie  the  ri-tlecteil  wave  is  fused  with  a 
|*iury  wave  near  the  block  (Fig.  83.  VI.  •>  a.  a'),  but  bcoomes  more  mid 
HR  trparattd  from  it  the  l\irtlier  back  toward  ihv.  pump  wa  trace  it  i  Fig. 
I3,L  1  ir.  ')').     N»w.  ihi^  is  not  the  caae  with  the  ilicrotic  wave,    i'areful 


iimneiiis  show  that  the  distance  between  the  primary  and  dicrotic  crtata 
■  ■tier  grCBter.  or  certnioty  not  Ims,  in  the  xmnllcr  or  more  distant  artvrice 
tbn  in  the  larger  or  nearer  ones.  This  feature  indeed  prnve«  that  the 
difMie  wave  cannot  be  due  to  reflection  at  the  peripherr.  or.  indeed,  in  niiy 
nf  ■  Teimcrade  wave.  Uendee,  tbe  multitudinous  peripheral  division  woul^ 
ndtr  ooe  large  periphically  rejected  wave  impooible.  Again,  the  more 
^iQy  the  primary  wave  is  obliterated,  or  at  least  diminished,  on  its  way  to 
■b  peripbery,  the  las  conspieuoiis  should  be  the  dicrotic  wave.  (lenoe 
bunwed  exictnubilily  and  increased  elasUc  reaction  of  the  arterial  walla 
■dick  tend  touaeup  rapidly  the  priiuari,-  wave.ahould  also  lessen  thedtcruiie 


■    \>v;i.AR    MECHAX19M. 

;■  1   -..jt::-  7    :  raa  th«e  conilitioiis,  as  we  havD  said,  are  favnr 

..::■-.     :  ;hr  liiiTniii'  wave. 

■< .  rluit?  sv,<i  till'  other  conditions  which  favor  dicrotUin 

i:»      \;v.".,'.  :."..#<,'  whidi  would  favor  such  a  developmeat  of 

'.-.-   13    !.i»  '.-t.>::  di'^'rilKil  above,  and  their  absence  would  be 

.I     !.■  ■;  -t^ka;  '.I'sui'h  wuves.    ThiiH  dicrotiaiii  is  Icaa  marked 

v-    -..'  '  1?:-''^'  of  old  people)  than  in  healthy  elastic  ones; 

.  :., ,     wa-j  ■>  so  naUilv  nor  shrinks  so  readily,  and  hence 

1,1.;    ■    ,■  '.    -■*  '■?  siu'h  s*fondary  waves.     Again,  dicrotism  is 

.   1  ■■  I     ..  -['v.i',  irtt'rial  jiresiure  is  low  than  wheti  it  is  high; 

,  .. .    ■  ,*.    -1    -  :  uvd  wheu  absetit,  or  increased  whoii  sliebtly 

;  -.■  ,  i;      '     rf  way  or  another,  the  mean  prusnure.     Row, 

v..  •    ■>   :  ^'1.  :'.••:  iruries  are  kept  continuallv  much  ex]Hinded. 

.•     "<    w  .-n:M.'i;  'f  further  exiianeion ;  that  is  to  say,  are, 

....1.       '  :<iu'-     !ii  ::ll:^ii[i<.>naI  expansion  due  to  the  systole  is  not 

.  ,1    >  t  <•«  ^-ll■:■.^^'v  tor  the  arterial  walls  to  swing  backward 

•i.  1,,.    tii.t    nu^f  a  Itss  tendency  to  the  development  of 

.,    -.      ^^   U.I      ii-  mail   pn'ssure  is  low,  the  oppusit«  slate  of 

- ..., .  x,,i.,     1  ■.■iir>f.  chat  the  ventricular  stroke  is  ade<juat«iy 

.     ,»»..-    hihl;  in,  n.'[  to  diminisherl  cardiac  force,  but  to 

. , i-i:i;iiv  .  :  !n'  rvliitively  empty  but  highly  distCD!<ible 

>     I  ,.,..:i.i,  i;ni, -iiiliti,:  r.ipjdlv  back,  eiitci^  uj>on  a  secoDtl- 

1,   ,.  ...  <...!    -ivii  .1  third. 

.    .....<    'I  'ill  <,.ii>  :ii.tv  be  applied  to  uxpluiii  why  sometimes 

.,    ^,.     ......^'.i     1  .1  :'arti<.'ular  artery  ubilG  it  remains  little 

■.  -!■  111.     [u  t'xiierinieuting  with  an  artiticial  tubing; 

.  .    ,       ■■  ,.\'..      i'lsical  I'hnrapters  of  which  remain  ihe 

■ ■.    •.--tiA-.y  .uid  the  secoiidury  wiivw  retain  the  same 

..ii;;     :■■-■   tubing,  .-avf  i)nly  that  both  gradually 

,..,..1.  i>      .11!. 1  ill  the  natural  circulatiou,  when  the 

.  .    „     '    I  I  :.':iii  ihroiigbuut,  the  jiulse  curve,  as  a  rule. 

....   .,      ,i..-K-;irs  througbijut,  save  that  it  is  gradually 

,.-,-.■  »iiv  to  mtbsiiiute  for  the  first  section  of  the 

..,.-.,'■     ■-■.■    -.iliiui;;  this  at  the  stroke  of  the  pump,  on 

.,.,    i..„  ■!  -Ii.'w  neither  primary  nor  secondary  ex - 

.  i:..,    .■;..■  .'['  the  pump's  Stroke  Would  be  transmitted 

;,,.i  .  Mvti.'ii.  and  liert  the  primury  and  ^coiidary 

• .'\  '.it'Lti.    This  is  an  extreme  case,  but  the  same 

,.     .     I    1 -.■.    iii;ri.t'  ill  putwiiig  from  a  more  rigid,  that  is, 
,  .  .    .11  .i.iir.  !..  K  le^s  rigiil,  more  cxtc-nsibic  and  elastic 

i    1..  ^,.i;irv  t<xpansions,  in  spite  of  the  general  dauip- 

,.,..%    ;i,  i.-iiac.     Similarly  in  the  living  body  a  pulse- 

>   .I'liu'Iling  along  arteries  in  which  the  mean 

'  ...1..1   !■.■  ilivivlun.'  practically  somewhat  rigid,  is  not 

.  .    '.,,  [III.'  wry  markedly  dicrotic  when  it  conieij  to  a 

.  ..  ....]    .1.  'iii'iiii  pressure  1:;  low  (and  we  shall  soe  pres- 

, I.. 1 1   .  iiiid  the  walls  iif  which  arc  therefore  for 

.    ,     >    ,.  ,.'  .i'..>[vii-^il>lt.'  than  the  rest. 
.     .        I.    'i i.-.i'1'viiiion  made  above  (^  141 )  that  the  curve 

■ K-  :.'■  nniiilii'd  by  llic  jtressure  exerted  by  the 

.    .  ,  i;i,i  ib:Lt  hcni'i',  ill  the  saniL>  artery  and  with  the 

.  ..    ii.ii..  and  cvfti  tilt;  sjiecial  features  of  the  curve 

n.    .i'  |.ivs.*ure  with  which  the  lever  is  pressed 

V  ;:._,^     \w  amount  of  dierotism  apparenl  in  a  pulise 

...>..!!■  i\trted   by  the  lever.     In    Fig.  6'>.  for 


TUB   rULSK. 


I 


I 


I 


iiMlnnn!,  th*  dlentie  wnvc  1*  nxtre  erident  in  tbo  mUMl*  tlian  in  tbe  upper 

1 147.  T\w  pro-<llcrotic  wnvi'  (mnrkfr)  !i  on  Fig.  t^7,  and  on  wveral  otlier 
flf  lhi>  puU«^urva>,  which  prt-ccdi-*  Ihc  dicrotic  wsva  and  is  still  nwre 
vvriililr  thxn  thai  vfsvo,  Ih-idi  iu)mciimc»  slight  or  even  invisible  and  some- 
tiuMi  onoRpiciiDUH,  Una  given  rue  Ui  rauch  conirovenir.  Id  th«  iiitorpretati»n 
of  UiN  ilicnitiu  ware  givvu  io  Uto  prccMliQg  paragraph  it  was  staled  that  the 
nrgntivn  prrMur^  'kvcluj>rd  on  the  wsMtiun  of  the  How  in  the  rear  of  the 
cohmtti  of  hlix)d,  led  by  itMlf  (o  a  reflux  toward  the  veniricle:  nni)  it  ha* 
been  suggeet^  that  at  this  reHiix  mcclinf;  and  cloeiuir  the  seniiluoaf  ralvc* 
■tKfbt  n  RDiall  wave  of  expansion  b«t<>re  the  larger  dicrotic  ware  bu  hwi 
tinKf  Io  develop  itself,  On  this  view  tbe  nniiliitur  vmlvea  wouhl  be  actiinlly 
cIimmI  l>ef<ife  the  oecurreflee  of  tbe  Mcondary  dicrotic  expansion  of  the 
artehnl  vinlls,  thixiKb  tbe  larjcer,  more  powt^rfnl  reflux  of  tliio  laUr  event 
iDiut  rvtider  tbe  cliMure  more  complete,  and  in  doing  ta  [ximitilv  givra  riee 
to  tbd  Moond  sound.  Accordini;.  Iiowerer,  to  lite  tecond  viviv  glvat  in  the 
Mne  Mimgrapb,  which  reKanbi  (be  reflux  due  to  the  vjiriuliing  of  the 
mtlery  in  face  uf  (lie  ^ratt  prt-Mttrc  in  front  art  firmlir  chMine  Ibe  soniilunar 
vmlvet,  uxJ  an  ibtu  startiii);  tbe  scctMidury  dicmtic  wavu  ot  cx|Mnsion,  itie 
firm  doaiDg  of  tbe  temliuniu-  valve*  nust  Uike  place  before  the  boginniug. 
iMt  (Itirini  the  developmeul  of  the  dicrotic  wave ;  il  is  mill  pomJhlc.  however, 
even  on  tnie  view,  m  od  the  other,  to  iiU]>piN(C  that  an  antix'cdeDt  rvflux,  due 
to  the  negative  prenure  wci-oeding  the  ucmatioii  of  flow  from  the  ventricle, 
doMa  lb«  va]v4«  and  slarti  tbe  p^^di<'rl>tic  wave.  But  the  matter  is  one  not 
ytl  bcvrind  the  (tage  of  controvervy. 

g  14&.  Ill  ao  anftrcrotte  yulu-  the  lirat  rise  is  not  tbe  highest,  bnt  a  second 
rise  t  II.  Kig.  aH)  which  follows  aiul  in  Mpnnitcl  from  it  by  a  notch  is  hif[hcr 
Umn,  or  at  lewt  aa  high,  aa  llaalf.  Sucb  an  aiiarcrolio  wave,  tJiougfa  it  may 
MMiMtina  be  proiluoed  tem|H>rHrily  in  healthy  persons,  is  senerally  ama- 
dhtted  wltb  disnued  conditions,  usually  such  in  which  (he  arterieB  are  ab* 
noniially  riKid.     In  dt-Hi-rihing  tbe  vctilricular  aysiole,  wc  spoke  of  tbe 

iinwHirv  within  the  vt-otriili'  as  reaching  its  maximum  jnst  before  the  open- 
Dg  uf  the  seniihinar  valvcn ;  and  ibis  is  apparently  the  uuruial  event ;  but 
then  are  <:urves  which  seem  to  show  Ihai  after  Ibe  linti  sudden  rim  of 
prawuru  wbi«b  opeu»  tbe  valves,  followed  by  a  brief  lenening  of  pniKuro, 
which  appears  on  (be  curve  us  a  notch,  the  pr««ieure  tuay  again  riae.and  that 
to  a  |Kiint  higher  than  before.  AihI  a  similar  curve  is  xoinetimed  deecribed 
by  tbd  frunt-to-back  diameter  of  tbe  ventricle.  The  syslule  o|ieiu  tbe  valve 
■•  it  wvtt  with  a  burst ;  thia  is  followed  by  a  slight  relajxto.  and  then  the 
systiile,  strvDgtbeuing  again,  dischargee  tbe  whole  uftla'  ventricular  contents 
inlii  tbe  aurta  and  su  bringti  about  a  tardy  maximum  exiiiuiaton.  And  what 
is  tbii*  started  in  Ibe  at*na  travels  onward  over  the  arterial  Mvstem.  It  is 
ditficnlt  U>  »ce  bow  tbeae  anacrotic  events  can  lie  priHluceil,  except  by  a 
certain  irregularity  in  tl>e  ventricular  systole;  aiHl,  indi-cd,  the  iinacrotic 
pulac  in  rn-i|iii:ully  awuciatitl  with  some  disease  or  defect  of  tlu^  ventricle. 

(  14S.  I'l  Hom  fiuhf.  l-'nder  ct-rtHin  i'iri-umstance!<  the  puW  may  be  car- 
rierl  on  frtmi  th<i  arleriiii  thn^iKb  iIk-  CHpilliirii-x  into  the  veins.  Thus,  as  we 
•ball  see  Inter  •>».  whi-n  iht-  Hnliviiry  ^^liuid  ia  aeltvcly  K'crcting,  the  blood 
nmy  iw>ir  from  the  gland  through  iIh;  vcini>  in  a  rapid  pulsating  stream. 
T]>r  nrrvoii*  vvcnis  wbieh  give  ru«  to  tbo  secretion  of  stilivii,  lead  al  [be 
tame  time,  by  the  agcnry  of  vasomotor  ocrvce,  of  whieh  we  will  presently 
•peak,  to  n  dilatali'iii  of  the  xmall  arli-tii-a  of  the  gland.  When  the  gland  is 
at  rrst  tile  minute  arteries  arv,  u  wc  sbnll  kc,  sonicw  but  constricted  and  uar- 
rnwnl,  and  thus  contribute  largely  to  the  peHpberal  resistance  in  ibe  part ; 
tliia  iwripberal  recistaaco  throws  into  actio«i  the  elastic  projwrtkti  of  tbe 


240  THE    VASCl'LAR    MECHANISM. 

email  arteries  leailing  ti)  the  gland,  and  the  remnant  of  the  pulse  reaching 
these  arteries  is,  as  we  Ijefore  explnined,  tinally  deatruved.  When  the  minute 
arteries  are  dilated,  their  widened  ehanuets  allow  the  blood  to  flow  more 
«aidi!.v  ihrouj^h  them  and  with  less  friction  ;  the  peripheral  resistance  vhich 
they  normally  offer  is  thus  lessened.  In  consequence  of  this  the  elasticitv  of 
the  walh  of  the  small  arteries  is  brought  into  play  to  a  less  extent  duu 
before,  nnd  these  small  arteries  cease  to  do  their  share  in  destroying  the 
pulse  which  comes  down  to  them  from  the  larger  arteries.  As  in  the  cue  of 
the  arliHeial  model,  where  the  "  peripheral  "  tuning  is  kept  open,  not  enough 
elasticity  is  brought  into  play  to  couvert  the  intermittent  arterial  flow  into  a 
continuous  one,  and  the  pulse  which  reaches  the  arteries  of  the  gland  paaKS 
on  through  them  and  through  the  capillaries,  and  is  continued  on  into  the 
veins.     A  similar  venous  pulse  is  also  sometimes  seen  in  other  organs. 

fureful  Inieings  of  the  great  veins  in  the  neighborhood  of  the  heart  show 
elevations  and  depressions,  which  appear  due  to  the  variations  of  in tra-cardiac 
(nuriciiUr)  pressure,  and  which  may,  perhaps,  be  spoken  of  aa  constituting 
a  "  vcuoua  pulse."  though  they  have  a  quite  difierent  origin  from  the  venous 
pulse  just  descrihetl  iu  the  salivary  gland  ;  but  at  present  they  need  further 
elucidiition.  In  casea,  however,  of  insufficiency  of^  the  tricuspid  valves,  the 
systole  of  the  ventricle  makes  itself  distinctly  felt  in  the  great  veins  ;  and  1 
distention  travelling  backward  from  the  heart  becomes  very  visible  in  the 
veins  of  the  neck.    This  is  simiettmes  spoken  of  as  a  venous  pulse. 

Variations  ()f  pressure  in  the  great  veins,  due  to  the  respiratory  move- 
ments, are  also  sometimes  spoken  of  as  a  venous  pulse;  the  nature  of  these 
variations  will  be  exp1aiuc<l  in  treating  of  respiration. 

The  Regulation  and  Auaitatios  ok  the  Vawui-ah  Mechamsh. 

Tile  Jte/jiihitioii  of  the  Beat  of  the  Heart. 

§  150,  So  far  the  facts  with  which  we  have  had  to  deal,  with  the  exception 
of  the  heart's  heat  itself,  have  been  simply  physical  facts.  All  the  essential 
phenomena  which  we  have  studied  may  be  reproduced  on  a  dead  model. 
Buch  an  unvarying  mechanical  vascular  system  would,  however,  be  uaeless  to 
a  living  body  whose  actions  were  at  all  complicated.  The  prominent  feature 
of  a  living  mechanism  is  the  [>ower  of  adapting  itself  to  changes  in  its 
internal  and  external  circumstances.  In  such  a  system  as  we  have  sketched 
above  there  would  be  but  scanty  |><>wer  of  adaptation.  The  well-constructed 
machine  might  work  with  beautiful  regularity  ;  but  its  regularity  would  be 
its  destruction.  The  same  quantity  of  bloo<l  would  always  flow  in  the  same 
steadv  stream  through  each  and  even'  tissue  and  organ,  irrespective  of  local 
an<l  general  wants.  The  brain  ann  the  stomach,  whether  at  work  and 
needing  much,  or  at  re.-^t  and  needing  little,  would  receive  their  ration  of 
bloiwl,  allotted  with  a  pernicious  monotony.  Just  the  same  amount  of  blood 
would  pus.'  througli  the  skin  on  the  hotten  as  on  the  coldest  day.  The 
canon  of  the  life  of  every  part  fur  the  whole  period  of  its  existence  would 
be  furnished  by  the  iiihoni  diameter  of  its  bloodvessels,  and  by  the  unvarying 
motive  power  of  the  heart. 

Such  a  rigid  system,  however,  does  not  exist  in  actual  living  beings.  The 
vascular  mechani.«m  iu  all  animals  in  which  it  is  present  is  capable  of  local 
and  general  modifications,  adapting  it  to  local  and  ceneral  changes  of  cir- 
cumstance.    Tliei*  modilicalions  fall  into  two  great  classes: 

1.  Changes  in  the  heart's  beat.  These,  being  central,  have  of  course  a 
general  effect ;  they  influence  or  may  influence  the  whole  body. 


241 


» 


1.  Oiaii|;»  in  llie  peripbentl  rewlimre,  due  to  variations  in  tlie  celihn-  of 
iji«  niioiite  arteri«v,  lirouybi  about  by  tJie  ageucjr  of  tbeir  couirarlil«  luiiv- 
itiUr  coaU.  TIkm  cbangai  mny  be  dtber  local,  aflbctine  a  uarlictilur 
vuctilar  area  only,  ur  genenJ,  atfiKUiig  all  or  nearlj  all  ihe  Dloutlva»els  of 
tbe  body. 

Theae  two  da«e8  of  «v«dI«  are  cbiefty  governed  by  (be  ncrrou*  tvMeni.  It 
)•  by  ineaiia  of  lli«  ii«rvoU)i  •rctcm  thiit  tl;u  liciirt'*  Ixtul  imil  the  ciilihrA  of 
tbo  minute  oriemti  are  bmiigbt  into  n-lntion  wiili  ciicli  otber.eixl  with  almost 
vvorv  [«n  of  the  IkiiIv.  It  ii  by  int.<nns  uf  lliv  nvrvous  «yatviii  scliog  ciihrr 
Ob  tM  heart  or  ud  tbe  »inal)  iirt«rM«.  or  on  IkiiIi,  tlint  it  change  of  drcnm- 
MaocM  Bfieting  citiwr  the  whole  or  a  port  of  (hi-  lioiiv  is  mvt  by  c^nijiciwitinj; 
or  ngulativc  cliaiigci>  in  ibe  (low  of  blood.  It  i*  by  niiL-»nc  of  tbi-  nervous 
tjfUim  ibal  an  orgnn  Ims  a  more  full  supply  of  blood  when  at  work  than 
when  at  net,  that  the  lide  of  blood  ihrcuch  lli«  «kin  rises  and  ebbs  nilh  tbe 
rift  and  (all  of  the  (eniperaluTe  of  the  air.  that  the  work  of  the  heart  la 
tctppered  to  meet  the  strain  of  overfull  arleriee,  aud  that  the  arterial  gates 
•  ipTD  and  Hbut  as  ibe  force  of  the  central  puni|i  waxee  and  W8u«8.  The 
study  of  these  changes  ljecoiiie«,tbei«fore,b>  a  iar^e  extent  a  study  of  uervoua 
art  inns. 

The  drcutalioD  mar  abu  Iw  modifled  by  events  not  belunj^n^  to  either  of 
the  above  two  classes.  I1iu»,  in  thin  or  ibat  peripheral  area,  obaiigivi  in  iJie 
capillary  walls  and  the  waltn  of  the  minute  arteries  and  veins  may  lead  to 
an  increase  of  tlie  tendencv  of  thL-  blond  cirouuclea  to  adhere  to  Ih*!  vu.-H'nlar 
walls,  and  to,  i|uile  apart  from  any  diauj/e  in  the  calibre  of  tli<!  blood v<rtte Ik, 
may  lead  to  increase  of  ihi^  periplx^nil  moxtttnce.  Thin  is  wen  in  un  vxtreme 
cKM  ill  in  dam  mat  ion,  Inti  may  [Hjwibly  intervene  to  a  Uw  extent  in  the 
nnlinary  mndilion  of  the  circulation,  unit  niuy  al»o  be  under  the  iuHuence 
I  ihu  nrrvouB  system.  Further,  any  deciilwi  chunge  in  lb*  quantity  of 
actually  in  circulation  must  aUo  inrtiience  thir  working  of  the  vascular 
ninisni.  But  both  lho«  phnngcs  arc  iinim|H>nant  compiirod  with  the 
two  kiiulfi  of  chiin);t'8.  Ilciice,  the  two  nn»l  ini{H>rlHnt  problems  for 
us  tit  Mudy  nr^'.  1.  how  the  nervous  system  regulates  tlit^  bent  of  the  heart, 
anil  'J,  how  lid'  iicr\'uu!-  system  regulates  the  calibra  of  tbe  bloodv^sels.  We 
will  finst  cNiimitler  the  former  problem. 


<i  16L  It  will  be  netmaary  now  lo  take  up  certain  points  tyiiiceniing  the 
minute  Hnicture  of  tiM  heart,  which  we  had  previously  jxwtjMtned ;  and 
iinre  much  of  mit  knowlcilgt^  nf  liie  nervuus  mechanisti)  of  th«  b<«t  of  the 
benrt  i»  drrivtsd  from  expcriincntH  on  tbe  hearts  of  cold' blooded  nriimiils, 
iiiof«  particularly  of  the  fru^.  it  will  be  dtwrablc  to  consider  tbew  as  well  as 
the  tnatHtnalinn  hi-«rl. 

t  iir<lt<tr  iiMi'fulnr  tU'iir.  The  vcntrii-le  i)f  the  frog'n  heart  is  composwl  of 
miiiolc  i»j>iii<n<-KhB|>ctl  tibn«  or  fihre-oell*.  vuch  i-oniAining  a  uiiclciis  tn  its 
middle,  mid  tapering  i<>  n  pout  itt  each  end  ;  Koim^timiit,  honevcr,  tbi.':  end  is 
forked  or  even  branched.  Th«Me  filtr>^  «r  tilinf-ocll*.  in  fact,  resemble  plain 
eular  librt»  save  that  ibey  are  somevrhal  iarvvr  and  that  their  substance 

Wriatnl.  The  strialion  is  duo,  like  the  striation  of  a  Ktrialed  muscle 
t.  111  alternate  dim  and  bright  tHtuds,  hut  is  rarely  so  distinct  as  in  a 
rial  rtbre:  it  is  ver}-  apt  to  be  obscured  hy  the  prownce  of  dispersed 
ilinlinrt  granules,  which,  in  msny  cases  at  all  uvenle,  are  of  a  fatty  nature. 
Like  th*-  ])lai»  oiutculur  fibre,  tb«  cardiac  muscular  tibre  has  no  dtetinct 
Mifi'i'Ieiiiiiia. 


242 


TIIK    VASCUIiAK    UBCUANISH. 


A  ntinilwr  of  tbew  fi1ir«a  are  jniiied  br  oenwnt  Bill»Uui«e  infi  tinuJI 
Uiuillt«,  aiid  iheee bundlefl  are,  by  cbehelpot  connective  lisBue  wbicb  cam» 
DO  klocMlveawls,  woven  iuto  an  iiitricale  network  or  B[ioDge-woric,  which 
forn»  tli«  greater  part  of  tbe  wall  i>l'  Itie  vealricl«.  Imnitidiateljr  undvr  At 
[WricKrdiM  coating,  oooMatiug  of  a  layer  of  e]>illi«li<:iiil  {ilatea  raUng  on  a 
fioanectivii-tinue  aiaa,  tbe  mutcalar  tbsue  fornu  a  lliin  coiitinuoua  ■baet,  boi 
wilbin  thw  it  Kpnads  out  inta  a  sponge  work,  tbe  n>e«beM  vf  wliioh  pniwDt  a 
Iiibyriiitli  of  i>iuwik««  voiitinuouH  witb  the  caritjr  of  the  vi^niriclr.  Tbe  baa 
of  this  spoDge-work,  varying  in  tbleknea*  ani],  ibougb  iipimrvtitlv  irrvgular, 
amogea  on  a  definite  tvMna,  oonmt  of  buudl«»  or  miiKuUr  lil^rw  united 
br  oonnwtive  tJMiiv,  ana  are  coated  with  tho  itanic  endocardi*]  racmbnuc 
(flat  epitheliwd  plitt<'«  ratling  »u  a  connective- iimuo  bam*)  that  Htm  tbe 
cavity  of  the  ventricle  nitd,  indeed,  tlw  whole  interior  of  the  henrt.  Thr 
cavity  of  the  ventricle,  in  other  wotcIm,  opon»  out  into  a  Inbyrinlh  of  jwii'Mgiii 
reaching  nearly  to  tbe  surface  of  the  ventricle.  Wh^n  the  veniriele  ■ 
dilated  or  reluxc<d,  blood  flows  freely  into  am)  fills  this  Inbyrinib,  batbing 
tho  ban  of  the  sponge-work,  whicli,  in  the  a)«ence  of  capillBriea,  de|wnd  oo 
thu  hloud  for  their  nourishment.  When  the  voiiiricic  contracto.  the  blixvl 
i*  driven  out  of  this  Inbyrinth  a«  well  as  out  of  the  central  cavity.  Ht-iior. 
the  ventricle  wbon  dilalod  and  full  of  blood  is  of  a  deep  red  color,  «hi-ii 
oontracled  and  empty  is  extremely  pale,  having  little  more  than  tbe  color  of 
thr  muscular  fibres  themselves,  which,  like  siriated  fibrea,  puMcsa  in  their 
own  aniMiiance  a  certain  amount  of  hicmoglubiii  or  of  myohiSfnatiu. 

The  much  thinner  waits  of  the  auricle  OoiuiBt  of  a  much  Ibiiinnr  network 
of  similar  librcM  uuiit-d  by  a  relatively  lat^r  quantitr  of  coniKclive  ttnue 
into  a  thin  sIhwI,  with  the  pericardial  membrane  on  tbe  outside  mod  tbe 
cadocnnliHl  metubrane  on  the  inside.  Tlie  libra*  bnv«  in  the  auricle  a  much 
groHtor  tendency  to  be  branched,  and  many,  oaaning  to  be  tpindlo^baped, 
become  nlmoxi  tttctlale.  Among  the  obwurcly  nLriate<l  but  atill  striated 
fibres  arc  found  ordinary  plain  mu*i!ular  HbnM  which  incrcaie  in  relative 
ourabor  along  the  rmitii  of  tho  veitis,  rimw  c«vmi,  and  pulmoiialce,  until  at 
80HM  litth'  dintancv  from  the  )it-jirt  jilain  muscular  6bres  only  arc  found. 
Bloodvenots  are  absent  from  the  walla  of  tbe  aurieW  aW, 

In  Um  bulbil"  nrl(■^i•uu^  mixed  up  with  mtii-h  conncclive  and  elastic 
liasue,  are  found  fu*ir<irii)  fihro'  which  clo'e  to  the  vcntHole  >m  striated  und 
form  a  thick  layer,  but  at  A  certain  distance  from  the  ventricle  luee  their 
atrialion.  or  ratbor  become  miied  with  plain  muscular  iSbree,  and  form  a 
thinner  layer. 

$  1$8.  Ju  tbe  namnal.  both  the  ventricles  and  the  auricles  are  formed  of 

buiHlIeaof  muscular  tissue,  bound  together  by  connective  tissue,  and  arranged 

mon  wpeciallv  in  the  ventrictee  in  a  very  complex  system  of  aheela  or  bands 

ibpoeed  as  spirals,  and  in  other  ways,  the  details  of  wbicb  need  out  detain 

_^        In  ibe  auricular  Appendices  and  elsewhere,  tbe  bundles  form  irregular 

■networks  projecting  into  the  cavities. 

The  ounneciive  tiaoue  binding  the  muscular  fibred  t4;^ther,  unlike  the 
atfnspoodiug  ootinective  timuc  tu  the  frog's  heart,  is  well  supplied  with 
bloo<)vcsMils  belonging  to  the  coixmnry  aiy*tcm.  This  ouiincdivc  tivuc  forms 
on  tbe  inner  surface  of  the  cavities  a  couliouous  sheet,  tbe  connective- tissue 
basU  of  the  fiat  epithelioid  cclU  of  ihe  endocurlium,  and  on  the  outside  of 
the  heart  the  viaocrat  tayi-r  of  the  pitricanlium. 

The  hintoliigical  unit  of  tbi^e  miiKt^ular  bundles  is  neitlier  a  fibre  nor  a 
fusiform  fibro-ecll,  but  a  more  or  let*  columnar  or  prismatic  nucleated  cell 
generally  provided  with  <mc  or  awn  short,  broad  prooessw.  [F\g.  90.]  The 
nucleua,  wnich  is  oval  and  in  general  rv^emblos  one  of  the  nuclei  of  a  #tnaled 
fibl«,  b  placed  in  about  tlie  middle  of  tbe  cell  with  it»  long  axis  in  the  line 


THE    VASCULAR    UECUANtSM. 


iKni-fti. 


■ir  nil  lIUHi.  MUlK  IK  i  UfHal' 
ntimti.  »ni.titi%.  On  lbs  ttshl,  (ha 
IlulUur  ll>«  ■g|».-«la  vrlb  wllh  Ui^ 
iiucIpI  on  i-iMHliil  Moicwlul  41a- 
cnummuloally.) 


of  tbi'  luDg  (liiiDxtttT  af  iIk-  cell.    The  coll  IkmIv,  wbicli  is  nut  liixiiiiind  by 

any  ilvfiiiile  niirruti-mmii,  \*  KtrinUNl,  tti»ii);h  (riiocuroly  <o,  ncriMS  tbu  tuBg 

■licinntrr  iir  tho  c«ll.  llio   Ririaliuus  m  in   n 

skeUul  musok  Kbre  being  diH>  to  iho  tUivrna- 

Una  of  dim  mmI  bright  baixla.    As  in  lli«  fn^'* 

bmrl,  i;rutiul0'  are  IWi^nenlly  abundant.  <th' 

acriiriii^  ihe  stnatimi,  whicli  iiHlecd  tven  in  the 

abdCfM^eot'  umntileB  ia  never  so  disliticl  as  in 

ili«flbn8<»l'skel«Ml  miuclw-     Sucbucell  is  at 

«ftrh  end  joiiieil  by  reinent  Biih«laiic«  to  HimiUr 

oelU,  no<l   a   n>«t   •>(  mcU  celU  i-imstituicfl  n 

Mitliac  "{rmriitary  fibre.     Heni.-^,  a  cardiac 

flbra  b  II  fibn-  !<triMt«<).  but  wtthoiii  iinr<!i>lomma, 

mm]  divt<)r<l  by  tiartiuon*  of  reJiieiit  6iib«tBnoo 

tnu> M>tiH>» bat  rlou^itvd  ilivi«(<>iu  or  culls, each 

anntainiti^  a  nuclMW.     Many  of  tli«  nib  in  a 

tibro  bavv  a  uliort  bmod,  Ulvral  pruceai.   Buob 

It  prac«M  b  uniti-<l  by  cMnent  Mibn«Doe  to  m 

lirailar    pr»i;tw>  of  n  wll   twionging  to  an 

adjoining  tibre:  and  by  tbo  uninu  of  a  number 

of  tJirM  |iroocHu-«.  H  nniitb«r  of  parallel  fibm 

ar<*  forni^Nl   into  i\  uxixrirbat  oluw  nvtwork. 

Kacb  buDtlle  of  thu  carditu'  miidcular  tiwuu  in 

thus   itcelf  a  iiatwork.      THmo  bundlca  ara 

Airlbvr    wovirn    into   ni-tworks    br  oonnoctive 

liaeu«  ill  which  run  car>illarioe  anil  liirgor  blood- 

veaaels ;  aiid  dhoeu  <>r  oiindira  comiMMed  of  such 

notworlu  atv  arraii^'^d,  tw  we  have  said,  in  a  complex  manner  both  in  th« 

auricle  and  ventricle.     Hencu,  the  miucular  dub^iunoe  of  the  mammalian 

hnirt  is,  at  boitoni,  on  exoeediogly  complex  network,  the  elem4:nt  of  which 

i«  a  wtniewfaal  branched  nncleatetl  striated  coll.     U  may  Iw  rvmarkud  Ibat 

tbe  "  tnusculi  pectinali  "  of  the  auricle  and  tho  "  coliimnLV  carnca; "  uf  tli« 

vvntricle    suggeil  Ibe  orixin  of  the  inammaliau  hunrt  fn)ii]   a   iniiw4ibir 

Ubvrinili  like  that  of  the  iWi|t*s  ventricle. 

At  ibi'  cifinuienceiuvnt  of  tne  great  arterieii  thin  [icoulinr  eardiac  muscular 
tMMue  onucH  abruj>ily.  beinff  refilamd  by  tbn  ordinarv  iitructurei  of  an  anery. 
but  tbc  •triuted  miimiular  Bbrea  of  the  anricle  may  lir  traood  for  aome  du- 
taocv  al»n|[  bitfh  the  veiitt  oavie  aatl  venie  [lulmonalcs. 

tTniler  tb«  endonmlitini  are  frmwintly  prw^nt  ordinary  plain  muscular 
flbrw.  and  in  koidc  cawii  )>«cul!ar  ciOl*  arc  tuund  in  this  situalion,  the  uelU 
nf  ['urkiiij'-,  which  »r>-  intcreitlinf;  ninrpholngicallv  becaUK  the  budy  of  the 
ndl  anxiad  the  nucleus  is  nriliiiary  clunr  protoplasm,  while  the  outside  b 
■iriaiM]  lubatanoe.  Plain  muHcular  fibri-a  arc  wiid  al*u  to  snread  frum  the 
oadiinintium  for  a  ccrlnio  clistMtc«  into  the  nuricti to- ventricular  valves. 

ilSS.  Tlui  nrrTTM  of  tho  kimrt.  The  diMribution  of  nerves  in  the  heeut 
varii-a  n  guttil  Ai»\  in  diflerent  vcrli-hral>-  animals,  but  neverlhele^  a  k;eneml 
)>lai)  i>  tniit«  uT  IwH  evident.  The  vrrtclirate  heart  may  be  rcpirdetl  m»  a 
muaculnr  lube  (a  niiiglu  IuIm>,  if  lor  the  m'>riient  we  disrettanl  the  complexity 
(if  a  double  rircnlation  occurring  in  tlie  hi;;her  noimals)  divided  iuio  ■  wrlea 
(if  ciiaitilipn.  sinus  vetioeus  (or  junnioii  of  great  veins) — auriele,  rejitriole, 
and  bulhud  (or  cuuus)  arteriosus.  The  nervm  (with  the  exception  of  a  Hmall 
or-Tvc  which  in  aotoe  animals  reaches  the  he«rt  by  the  aorta)  enter  the  heart 
at  the  vut'iuB  end  nf  this  tube,  at  the  sinus  renoaiu,  and  pa^  on  toward  ibe 
arterial  md,  diminishing  in  amount  as  tbey  proceed  and  •lUappeunng  at  tin 
aorta.     ( InDoected  with  ibe  nerve  tibree  thus  paniog  to  the  heart  are  grou|n, 


286 


THE    VAl 


rBCHAKISll, 


At  ench  beat  llie  time  durip);  which  the  <.'ont«nU  of  tlie  left  wutricle  are 
injecwil  iiilo  (he  aurta  U,  tu  we  hnvt  leeu  (.^  13t>).  very  brief.  The  expnu- 
sion  of  the  aorta  b  very  sud^ten,  and  the  ocaiaiian  of  that  cxpaimon  is  alao 
very  >u<)den. 

^ow,  wlioti  lliiiil  U  l)«iiijt  dri\Mti  tvith  o^t'o  n  stviuly  preniire  tbrtHigh  an 
elastic  tubt!  or  n  syattm  o£  ehmtic  tiibvH,  levcnt  placed  On  the  lube  will 
de*cril>o  curvtw  iiidiating  VArintictnii  in  the  dtnmctvrof  th«  (iibclf  lUc  iiifluw 
int<.i  the  tube  bo  vuddcnly  Rtop[)cd,  u*  by  sharply  turning  a  etop-cock ;  and  a 
comjntriitoo  of  Icvcn  plovud  at  diflcront  distancn  ffx»iD  lb«  »top-cock  will 
ahavr  thill  thoie  variaUoiM  of  diamuter  trav«l  down  the  tube  from  the  stop- 
cock in  tho  form  of  wavoa.  The  lever  near  the  stop-cock  will  lirstof  nil  Dul, 
but  t>pce<lily  begin  to  rlsa  iignin,  and  this  subflcqueot  rise  will  bn  followed  by 
anqlticr  thil.afler  which  there  mny  be  one  or  more  ancceeding  rises  and  fnll«— 
thiit  is.  oscillfitions — vi-ich  dccreaaing  amplitude%  unt^l  the  fluid  conior  tn  rest. 
The  lot-ore  further  from  the  slop-cock  will  describe  curves,  similar  lo  th« 
aIiovc  in  form  but  of  tese  amplitude,  and  it  will  bo  found  that  these  MMrtir 
somewlial  Inter  in  time,  the  more  so  the  further  the  lever  is  trom  the  stop' 
cock.  Obviously  Ihese  waves  are  genemted  at  or  near  the  stop-eock.  and 
travel  thence  al<in^'  tlie  tubing. 

We  may  infer  that  at  each  beat  nf  the  heart  similar  wavea  would  be 
geoeraitMl  at  the  rout  uf  tlie  aurta  upon  the  sudden  cessation  of  the  San-  IJroiu 
the  ventricle,  and  ivoulil  travel  thenc«  along  the  einittie  arteries.  The  facia 
tJutt  each  beat  is  rapidly  succeeded  by  another,  and  that  the  flow  wliivh  sud- 
denly ceusex  is  also,  by  the  nature  of  the  ventricular  atruke,  suddenly  geo- 
eralcil.  may  render  the  wuvoi  more  complicated,  but  will  not  change  Uieir 
essential  nature. 

Tlic  exni-i  interpretation  of  the  gencnttion  of  th««o  wavex  is  perbajM  not 
without  diflieulty,  uul  two  factors  Mxm  of  esneciul  importance.  In  Ihv  first 
place,  iia  we  have  already  more  than  once  said,  when  a  rapid  flow  isauddenlv 
stopped  n  negative  pretaurc  makes  its  appearance  behind  the  column  of  fluid. 
Id  a  rigid  tube  this  umply  tends  to  a  reflux  of  fluid.  In  an  elastic  tube  iti= 
eflocte  are  complicated  oy  the  second  factor,  the  ela^itic  action  and  inertia  of 
the  walls  of  the  tube.  Upon  the  sudden  oeeeatioD  of  ihe  flow,  the  axptttisioit 
of  tlie  lube,  or  as  we  may  ut  once  say,  of  the  aorta,  ceases,  the  veeael  becilia 
to  shrink,  and  the  lever  placed  on  il^  walls,  as  from  .1  onward  in  the  pube- 
curve.  This  shrinking  is  in  part  due  to  the  elastic  reactiim  of  the  walb  of 
the  aorta,  hut  is  increued  by  the  "  suction  "  action  of  the  negative  iirtHoie 
siioken  of  above.  In  thus  shrinking,  however,  under  these  oumbined  cutseft. 
the  aorta,  through  the  im-rtia  of  ila  walls,  overshoota  the  mark,  it  is  carrie<l 
beyond  its  natural  calibre — i.e.,  the  diameter  it  would  poasew  if  left  to  iudf 
with  the  pretturc  inxidu  and  outaide  ^ual ;  it  shrinlu  too  rou<Ji,  and  ooiuse- 
*e(]uently  beeins  again  Co  expand.  Thii>  secondary  expatuion  i^ taking  for 
simplicity  take  a  nulMi-eurve  m  which  t)i*^  ho  called  pre-dicrotic  wave,  B,  is 
ubtHMil  or  inconapicuouN )  cau^tc*  the  HM;uudarv  ri»o  nf  the  lever  up  to  6^— that 
is,  the  dicnitic  rim.*.  In  thu^i  cxpunding  nsiiin,  thv  aorta  leiida  to  draw  back 
toward  llio  heart  the  (Hiliimri  i>f  blood  wliicl)  by  Iom  of  momentum  had  oomo 
to  nvl,  or,  indeed,  under  the  influvncc  «f  tho  negative  preasure  ()>oken  of 
above,  wim  alrviidy  undcrgi>inf^  ■  reflux.  In  thin  sccnndary  expaneion,  more- 
over, the  aorta  is  by  tho  incrii-i  of  ii.-<  wulU,  aidud  by  thai  of  the  blood,  again 
oarriet),  w  to  jjK-nk.  beyond  ila  mark,  wi  ihnt  no  sooner  hiis  il  become  ex- 
panded and  filled  with  fluid  ft  a  certain  extent  than  it  again  Itegins  to  shrink 
u  from  '_'  imwnrd.  And  thi*  shrinking  may  in  n  similar  manner  lo  the  first 
be  followed  by  a  further  expansion  and  shrinkint',  giving  rise  to  a  |Mist- 
dicrolic  wave,  or  it  may  be  lo  post-dicrotic  waves.  A.OU  the  Mocotsivi- 
changes  thus  inaugurated  at  the  root  of  the  aurta  travel  aa  so  many  waves 


TOB   PCLSK. 


237 


I 


I 


kliMS  the  vtariaJ  mt«iii,  dimiiiisliiiif;  ns  tkey  go.  It  will  be  oboen'et)  ihat 
fitr  ibw  ileTetoiiiiUMit  of  tl>p«e  itnvee  a  oorUuu  quality  iu  iho  iralls of  Uie  tubing 
ta  WTiCt— TV.  ThetulwiniiM  licaucb  fts  powMSeB  when  at  rcfll  an  o|)ei)  luuten; 
lh«  walls  uuK  be  of  such  a  kind  thtX  the  lube-  reniaiiia  open  wlten  eiuptv — 
L  *,.  wheo  Uw  atinca|iberic  pmaure  is  equal  innidc  and  •nilaide — A  that  vdeti 
it  ahriala  too  macb  it  exptUMlR  again  in  Mrivinj^  to  re^^n  U»  naiiiral  <-iili1>rc. 
Thi>  w«  have  K*a  lo  be  a  cfaaraeteriBtic  of  the  arteriea.  A  culliifMJbU-  lube 
of  lb''  '-.lae  will  not  ibtm  ib^  |>li«uotiK-na ;  audi  a  ttilw  wlioii  ihcxtup- 

eoek  '  .1  1  i-ollnpws  and  cuijitit*  ibH^lf.  vouliniiiug  ii>  be  cDlltiiAii]  witlf 
out  Msv  «Dwft  U>  ci|inDil  nuulD. 

In  tfw  above  ri|tlBiiHti»fi  nu  meutioii  had  been  made  of  tli«  clnainL'  of  the 
Mialliinir  valvw;  tv«  •ball  hnve  in  ^lenk  of  lb««!  ii  litllo  Inter  nti  in  rvfor- 
ring  to  ibe  ppn^icrotio  wave,  und  nball  wee  that,  under  lh«  vi«w  we  hiive  just 
giwB,  iht  c\tMag  uf  the  !>eiiiilLiiiar  valves  b  to  bo  rci^rdiNt  rather  lu  tliv 
•flbcl  tban  tli«  cauw  of  the  dii:ti>tic  wave.  Maay  nulbont.  buwevitr,  give  no 
fanaravetatlon  uf  Ibe  dicrotic  wave  diflenut  fnim  ihiit  detailetl  above.  Tbus, 
h  it  beld  tbat  Ibe  primary  tlirinking  Ironi  .-I  onwani,  being  brougbc  to  bear 
«■>  tW  (Mlamn  of  blood  alnady  come  to  rest,  in  bee  of  tbo  gnat  preatnre  in 
fVtnt,  drivt*  ibe  blood  back  aeainM  tba  wmilunar  valves,  thus  clwiof*  litem, 
aod  that  the  iaipncl  of  ttic  eolumn  uf  blood  against  tbe  valves  siarU  n  new 
war*  of  espaniion,  nhicli  ifinforcini;  the  uaturnt  tendency  of  tbc  oImUc 
wsJIa  to  expand  again  aficr  lliHr  prlranrv  ehritikint;.  produces  the  dierotle 
mn  C  On  this  view,  it  if  the  blood  dnvcn  beck  from  the  valves  whicb 
•xpUMb  tbe  artery ;  on  the  view  given  abure,  it  is  the  expanding  artery  which 
dmtrrs  ibe  blo<id  baek  townrd  ibe  valveH. 

MoteovtT.  fjuite  olber  views  have  been  or  are  held  ooneemini;  ibiai  dicrotic 
wa%-c.  AevirdioK  t"  many  authora,  it  is  wlial  k  called  a  "  ivtifcied  "  wnvc. 
Tlma,  «brn  lite  lube  nf  the  artifteial  niodcl  bearing  tnu  lev(irt<  is  blocked  jnat 
bwyunl  tbr  far  lever,  ibe  primary  wnvu  is  wen  to  beaoconiiuinW  byafecond 
waw,  wbteb  at  the  far  lever  in  wi-n  rlotw  tu,  ami  often  fusecl  into,  the  priniair 
wan  (Fig.  h3,  VI.  a'),  but  at  the  itcar  tever  is  at  some  distance  from  it 
(Fy.  H3.  I,  »').  living  the  further  IW)ai  it  tbo  longer  the  interval  between  Ibe 
Urrr  atxl  ibe  block  in  the  lube.  Tlu)  seennd  wave  t*  evidently  the  primarv 
wave  reflected  at  tbo  block  and  travelling  linckward  toward  the  pump,  ft 
thaa,  nf  eour^,  pospes  the  far  lever  before  the  near  one.  And  it  bai)  beon 
ATfon)  that  the  dierolie  wave  uf  tlie  nuUc  is  really  sueii  a  reHectetl  wave, 
•tertnl  either  at  the  minute  artfries  and  capillaHe*.  or  at  the  points  uf  bifur- 
«atioo  of  ibe  larv'er  arteries,  and  travelling  hnckward  to  the  norta.  But  if 
tUs  wervlbe  eaw.  ihe  distanee  between  the  iirimary  cmt  ami  the  dierulic 
cXHt  ougbt  to  be  less  in  arteries  more  distnnl  fmui  than  in  iboae  nearer  to 
tlM*  Iwnrt,  just  as  in  the  artificial  scheme  the  reflected  wave  ia  fined  with  a 
primary  wave  oear  the  bl<»ek  (Fig.  i<^,  VI.  H  o.  n'),  but  becomes  more  and 
man  sefanued  from  it  the  further  hack  loward  the  pump  ite  tract.'  it  <  Fife. 
A3,  L  1  M.  <>').  Now.  this  is  not  the  caw  with  the  dierolie  wave,  f'an-ful 
imawirrmrnts  abow  that  tite  dislam-e  between  the  primtiry  and  dlcmtic  c-rcsla 
>•  aillMr  gmter,  or  ecrtainly  not  leas,  in  the  Knvaller  or  more  distant  arteriea 
than  in  the  Inrger  or  nearer  oitea.  Thin  feature  indeed  prove*  tbat  iba 
dicrotic  wave  canniM  l>«  due  lo  reflection  at  the  |ti-ripherv,  or,  iniltx^il.  in  any 
way  a  retrogrado  wave.  Besidea.  the  niullitadJnous  |ieriplieral  division  wuultl 
mtder  one  large  periphically  rvAecied  wave  impoasibfe.  .\fn>in,  the  more 
rapMly  ibe  primary  wave  i«  ublilerated.  or  at  leiitt  diminulwd,  <>»  its  way  to 
tba  ptripbery,  tbi^'  Iom  oooapioiiou*  should  be  the  dierotio  wave.  Henc* 
iaoaMM  exienfibility  and  Inereased  elastic  rtnctioit  of  the  arterial  wxlla 
vbfafc  tcod  to  Use  up  rapidly  i)h-  |)rimary  nave,*li€iuld  nlso  IcMen  ibe  dierulia 


^ 


SS8 


TllK    VAHCTLAB    MKL'IIAMSII. 


vmw,    Btil  DM  n  nmtlcr  of  fact  Uinw  conditions,  ih  we  have  Mid.  ure  fnTur- 
mblc  U>  ihc  proniiiicntT  of  the  dicrwlic  wave. 

Od  tlie  other  hand,  thitw  nnd  thv  otWr  condilioRE  which  fiivor  dicrotiain 
in  the  pulso  aro  cinctli'  tho»c  which  would  favor  such  a  develofiiDeat  of 
gc'ondiii'T  waves  ns  hoe  dcvd  dcH^rituHl  nbove,  and  their  absence  would  b« 
unfavoriihio  to  the  ocrurrcnco  of  eiich  wave*.  Thus  dicrotism  in  les  iiiur][«d 
ID  rigid  arteries  Tsuch  ns  thoM  of  old  noopio)  tban  in  healthy  elastic  ODU; 
tiw  rigid  wall  neither  expands  so  readilj-  nor  Bhrinlu  so  readilj,  aod  heme 
does  not  so  rendily  give  riw  to  such  secondary  waves.  Af^in.  dicrotiaiD  ia 
more  marked  when  the  mean  arterial  prcssure  is  low  than  when  il  is  bigh  ; 
indeed,  dicroiism  may  be  induced  when  absent,  or  inoreased  when  slisluly 
marked,  by  diminifihing,  in  one  way  or  another,  [he  mean  pressure.  Now, 
when  the  prenaure  is  hJKb.  the  ai'teries  are  kept  cuntinuallv  niueb  expnnd«d, 
and  are  therefore  the  le&s  capable  of  liirther  ex]»ausion ;  tliut  ia  to  ny,  ar». 
so  iar,  more  ri^id.  Uence  ine  additional  expausioD  due  to  the  aystolo  ia  iioC 
vcrv  great ;  there  in  a  lew  teodeooy  for  the  arterial  wulU  to  awiog  backward 
waa  forward,  so  to  speak,  and  hence  a  lens  tendency  w  the  dcvelapm«ni  of 
Mcondary  waves.  When  the  mean  preasuro  is  low.  tb«  opposite  itata  of 
things  exitiiH ;  tiuppuainj,'.  of  counte,  that  tlie  ventricular  etn>ke  i*  actcquMcly 
vigftroutt  ( the  luw  prcwure  beiti^-  duo.  not  tu  diininiiihed  cardiac  force,  but  f  > 
(liminixhud  |>tripfaeral  resiataiiOL-).  the  relatively  empty  but  highly  di.-xriii^iblc 
irtvry  in  rapidly  expanded,  and.  fallinf;  rapidly  back,  cnlcrt  ujkjh  k  wcond- 
arv  (dicrotic/  expansion,  and  rvuu  ii  third. 

Moreover,  the  .name  principlis  may  bi^  anpliod  U)  explain  why  anmctimc* 
dicnilivni  will  apiwar  murk<.-d  in  ii  pHriii-iilar  artery  while  it  remains  little 
narked  in  the  nwt  of  the  Hystem.  In  *!X|iirrin)cD[ing  with  an  artificial  tubing 
euch  as  the  arterial  nitxlel,  the  physical  cbimictcn  of  which  remain  the 
■anio  throughout,  bulb  thu  |)riRinry  and  the  sccoodary  wnv»  relaio  the  same 
obaracters  as  they  travel  along  the  tubing,  save  only  that  both  gnulually 
diminish  toward  the  periphery  ;  and  in  the  natural  circulation,  when  tlie 
vascular  conditions  are  fairly  uniform  throughout,  the  pulse  curve,  as  a  rul«, 
poaMsses  the  same  general  characters  throughout,  tave  that  it  is  gradually 
••  damped  off."  Bui  suppose  we  were  to  substitute  for  the  lirat  section  of  the 
tubing  a  piece  of  perfectly  riKi<l  tubing ;  this  at  the  stroke  of  the  pump,  uu 
account  of  its  being  rigid,  would  show  neither  primary  nor  secondary  ex- 
pansion, but  the  expanding  force  of  the  putup's  Htroke  would  be  traniuilled 
through  it  lu  the  second  elastic  secljon.  and  here  the  primary  and  aeoondary 
wavM  would  ut  once  become  evident.  This  is  au  extreme  case,  but  the  aame 
thing  would  be  aeeu  to  a  leas  decree  in  passing  from  a  more  rigid,  that  ia, 
lam  cxtctuiible  aD<l  elastic  wotJon,  to  a  less  ri^d,  more  extensible  and  elaxtlc 
Mction;  the  primary  and  secondary  expam^ion^,  iu  npice  of  the  veneral  dump- 
ing «flVt,  would  suddenly  increase.  Similarly  in  the  living  Doily  a  pulito- 
ciirve  which,  no  long  aa  it  U  travelling  along  arteriu  in  which  tlw  nu-AH 
prcsaure  ia  high,  and  which  are  therefore  praulicully  ^mewbut  rigid,  is  not 
markedly  dicrotic,  may  l)ec(imti  very  markedly  tlicroiic  when  it  <umn  to  a 
|Hkrtini1iir  artery  in  wbidi  the  mean  ]>reMture  U  low  (auil  nc  shall  kc  pres- 
ently that  nuch  a  case  may  occur),  and  the  walls  of  which  arc  Ihervforc  for 
tltc  time  ttcing  relatively  more  diiiteniiible  ihau  Uie  r«cL 

littslly,  wo  may  recall  Uic  observation  made  above  (§  141)  that  llio  curve 
of  expaiieion  of  an  elastic  tube  is  motlified  by  the  preseura  exerted  by  (he 
lever  emplovod  to  nK.'or<l  it,  nnd  that  bciicc,  in  the  same  artOfy  mid  with  the 
same  in^trnmcnt,  the  nine,  form,  and  even  the  special  fcjiiures  nf  the  curve 
vary  according  to  ihe  amount  of  pnwmrc  with  which  the  lever  is  pmssvd 
u{".>n  the  artery.  Accordingly  tlic  amount  of  dicrotlum  apparent  in  a  pulse 
may  bo  modified  by  the  prcmurc  exerted  hy  the  lever.     In  Fig,  80,  for 


I 


TOE  rULSK.  289 

iaaiBMtt,  l)ie  dicrotti'  wave  it  moro  ovidont  iu  Hw  muldlo  tluiii  iti  tlic  U|>per 

$  147.  Tbv  pr»-<licn>tic  wmvv  (nmrkctl  A  on  Pljr.  HI,  nod  od  seveml  other 

of  tbr  pulw-^tmcs),  which  pit-Mdcv  iho  dicrotic  wave  mid   u  still  mure 

Tarisblv  Ihmi  thai  wkvo,  beiug  soniviinii-s  slight  or  oven  invisible  niid  soiue- 

timM  ooHpKilMH,  has  given  nw  to  miifh  controversy-    In  the  iot«ri>retatioD 

of  tlM  £erntio  irav«  given  in  the  nrcccdiii];  imni^riiph  it  wu  slatM]  tlmt  the 

OMBlIr*  praMure  developed  on  the  eesaatioo  of  the  flow  iu  lh«  rear  of  the 

CDMBUiar  blood,  kd  bjr  iuelf  to  a  retlui  toward  ilic  ventricle;  and  it  hn* 

hrra  9afgm,ted  that  at  thif  reflux  meeting  and  elosins  the  aemiluaar  valvi.» 

•buta  a  BOiall  wave  of  ezpnnsiou  before   the  larxer  dicrotic  wave  )uu>  bail 

tisM  to  develop  ii«eir    On  thia  view  the  seiniluiiarvaJvei  would  be  actuull}' 

dflMd  Ikefore  the  ocetirreoce  of  the  seoondary  dicrotic  expansion  of  the 

arl«n»l  nails,  though  the  larfft^r,  more  |M>wer(ul  reflux  of  thi*  lat«r  event 

mnu  rvuder  tlw  tlmure  n>ore  L-oinplete,  uud  iu  duiug  so  prxvihlv  gives  rise 

to  ibm  peoond  muud.     Aecordinu;.  however,  to  tiie  aeicoitd  view  xivui  ia  the 

MUM   Mragraph,  which  regard*  the  reflux  due  lo  the  Kbrinlciug  of  the 

arterjr  to  fooe  of  the  great  pntwire  iu  front  as  Krinly  closinz  the  semilunar 

■BlTaa,«lid  U  thus  starting  tlie  semniUir}- dierutio  wave  ofexpaDiion,  the 

film  dMiag  of  the  somliiinar  valvCM  must  take  place  bofbra  the  bc^nning, 

Ml  dariiu  the  dev«)i>po>enl  i>f  the  dicmtic  wbv<>  ;  it  is  Mill  poi^blc,  however, 

ima  OB  tail  view,  a*  on  the  otluir,  to  mpjiotu;  that  au  antccttdcal  refiux,  due 

t*  A«  iMeative  preanira  wioccediDg  the  c'cssation  of  fluv  from  the  ventriele, 

dotes  U>»  valvM  and  Utrts  the  pr^icrollc  vravc.     But  iliv  matter  is  one  not 

jM  bevond  tht'  flago  of  coniroverey. 

)t40.  In  an  anarcrotii-  y\i\fV  the  lint  rise  is  not  the  high4«t,  but  a  seeund 
rm  11,  Fig.  Ml  which  f<>lliivt:>  and  is  sijpnnitrt!  from  it  by  n  notch  u  higher 
tkBB,or  at  least  as  high,  as  ileolf.  Such  an  anari-rolie  wave,  though  it  may 
■wdoes  be  produced  ieni|xintrily  iu  healthy  pentoiM,  is  generally  MW 
(bud  with  diseased  eundiiioits,  usually  such  in  which  the  arteries  are  ab- 
Mnally  f^^i-  Iu  des«rribing  the  ventricular  iyutule,  w«  spoke  of  the 
■■m*  vUbin  tlie  ventricle  as  reaching  its  tuaximuin  just  before  the  open* 
■gof  tba  ■emiliinar  valves;  and  this  is  appareutly  the  nornuil  event ;  Imt 
iWn  are  ctirvea  whicli  seem  to  show  that  aller  the  fimt  suihluo  rise  of 
fnpurs  which  opens  the  valves,  fullowei)  by  a  brief  Uwcning  of  pressun, 
efcich  appcara  on  the  curve  us  a  notch,  the  preeaun:  may  again  risc,nml  thai 
Its  putBl  higher  than  liefure.  And  u  similar  curve  is  •nmeiimri)  il««cribed 
\if  the  Auot-to-hai-k  diaincter  of  the  ventricle.     The  tiyalole  opens  the  valve 

■  ilvSf*  with  a  hunt :  this  i*  followed  by  a  slight  relapse,  and  then  the 
ntdt,  stimgthoning  a^in,  discbatget  the  wholt^  of  llie  vriitrici>lar  conleolt 
klalM  aorta  and  »u  brings  about  a  tardy  maximum  ctjinniinn.     And  what 

■  tliin  tlarteil  in  the  nuiiM  tranll  onward  ovrr  the  Btlerial  system.  It  is 
<Unih  to  ter  hiiw  tltew  anacrotic  ercnts  cnii  Iw  pnxliiM-d.  excupt  by  a 
Riiaih  irrrgulantj  io  Lbs  vcairiailar  •vsiolv;  uid.  indeed,  the  anacrotic 
pobt  is  fn-i|uenily  Hwoeialed  with  some  iliMtnw.-  or  defect  of  iliit  ventricle. 

iU9'  l'ri*ou4  pultr.  Unitor  n'rtain  (-ireum»tnncn  ilie  pulse  may  be  car- 
■W  •■  from  the  arteries  ihrriiigh  tbr  uipillnrics  into  ihc  veins.  Thus,  as  mc 
liall  sea  later  on,  when  th«  salivary  eland  is  actively  Meriting,  the  blond 
nnyiiaue  from  the  gland  through  the  veins  in  a  rapid  pulsating  etn.-nui. 
Tfat  aerroua  events  which  ^ivc  rise  to  the  secretion  of  ualiva,  lead  at  the 
•Bs  tline,  by  the  agency  ol  vasomotor  nerves,  of  wfatrh  we  wtll  prcHcntly 
i|nk,t»  a  dilatation  of  the  small  arteries  of  the  glai>d.  When  the  gland  ts 
Ufrst  \iw  ininuiv  arteries  are.  as  we  shall  see,  somew  hat  ooustricled  and  nar- 
iMtd.  and  thus  contribute  largely  to  the  peripheral  resislanoe  in  Ihe  part ; 
Iki*  psripberal  rtsistaure  throws  iuto  action  tbc  elastic  pm|ienics  of  tlie 


240  THK    VASCfl.AR    UKCHASISM.  ^^^^^^P^ 

SRUlI  tutcrif*  loAiliii^  to  lUv  )clai><),  nml  l)ie  ri^miiiint  (if  the  |)iit>e  renctiiiig 
tliCM'  nrU'-ric's  i,*,  lis  wc  Ix'forv  ex|)l)iiiM'il.  tiiinlly  (K-ntriivol.  Wlii-ii  tht?  miauie 
nrtvrit^  nn;  ililiiti>i),  tlieir  nideiinl  cliunutils  nllnw  tlio  Muml  (o  lti>w  iitoro 
c3«i1v  ihrotij^h  ttiviii  iiiiil  with  leav  frii;ttou  ;  Ibc  {H-ri|)hcral  n'^iiitiiiirr  wliirh 
thi-y  normiilly  itffvr  in  llms  Jf.-wticil.  In  Gpn*v<^ucn«-  of  tbU  tlu)  daolicitv  of 
thcirall»  of  lliv  Hmnll  iirtcrii^  m  brought  into  })Uy  to  »  Icn  «xU.-iiI  tWu 
beforo.  tind  tlien?  «iiii>11  BrterieM  cotMO  to  <)o  tlifir  ahnro  in  dcstrojri'^  ^ 
pulse  wliirh  oonics  dnwti  to  tboin  from  the  lnrfi:('r  ancrim.  As  in  th«  case  of 
the  artitidal  niod<;l,  where  thu  "  |>i;ri|ihrriil  "  lulling  i«  kept  "]ii;ii.  n»l  <'tniiigli 
«liuticity  i«  tiroiight  into  jility  to  convert  Ihc  intermit t«ni  Krieriiil  How  into  m 
continuous  one.  nnd  the  jiiilw  which  rnichcs  the  3irt«ri«B  of  the  giniiil  peuncJ 
on  through  them  nnd  through  the  ni^illiirics,  iiad  U  <:oiitinucd  un  into  the* 
v«iiia.     A  Bimilnr  vcdous  pulee  ii  also  '•onietimea  seen  in  other  orvaus. 

I'arvful  trneingH  of  the  grent  veins  in  the  nenghborhood  of  llie  liearl  shnw 
elevations  and  deprcanons,  which  appear  due  to  liic  varialtansof  iotra-cardtsc 
(nuricular)  prewure.  and  which  may,  perliaps.  be  spoken  of  as  cooslitultny 
n  "  v<<nnu!i  pulse."  though  tliey  have  a  quite  ditferent  origiu  from  the  vraoue 
pillie  just  dcHcribe-l  in  the  salivan-  glaml ;  but  at  present  they  Deed  further 
eluciiMtinn.  Iii  uiises,  however,  of  insutiicieney  or  tJie  tricuifKd  valves,  the 
•v«lolv  of  thi^  ventricle  makee  itoelf  disliuctly  felt  in  the  great  veiits ;  uiil  a 
^fisliMiiion  travvlliiJi:  backward  from  the  heart  beoomee  very  vUible  in  the 
veiiiH  of  thv  neck.    This  i*  xotuelttncii  :<poken  of  lu  n  venoUM  ptibie. 

Vnrintion!)  of  preixure  in  the  ^reat  veiii»,  due  to  the  rcKpirnlorr  mor^ 
nienls,  arr  nlno  mnietttuea  iipoken  of  an  a  reuoti*  palw;  tJiv  nnlare  (if  ihew 
variation*  will  bn  uxplaiucd  in  treuliug  of  rcspintioit. 

The  Redulatiox  akd  AoArrATioy  or  the  Vascular  MecnANtoM. 
b  The  Itfyufatlon  o/  the  Bmt  of  the  Heart 

§  ISO.  !v>  Gir  tlic  fiu-ts  with  which  w«  have  hnd  to  d«nl,  with  the  exevptioa 
cf  tlw  heart's  beat  itaclf,  have  l>eei)  simply  physical  facts.  All  the  ^vMntiftl 
pbenomcna  which  we  have  studied  iriay  he  rrjiroducFd  on  a  dead  modfll. 
Such  an  unvarying  mechnnicid  vascular  system  would,  bonevor,  be itaelenio 
a  living  body  whose  aclionn  wen?  at  all  complicated.  The  promiodnt  CwtoK 
of  a  living  mechanism  is  the  power  of  adapting  itself  to  cbangea  to  iu 
internal  and  external  circumstances.  In  such  a  svstem  as  we  have  sketched 
alMive  there  would  be  but  scanty  poircr  of  adsptittiun.  The  well-construcMd 
machine  mi^hl  work  with  beautiful  regularily :  hut  its  regularitr  would  be 
Ha  tleBtructioD.  Tht?  Dame  quaniitj  of  blow]  would  always  How  in  the  ttme 
•teody  BlroaiD  through  each  and  everv  tissue  nnd  ori;un,  irrespective  of  local 
auil  general  nanta.  The  brain  and  the  stuTuacli,  whether  at  work  awl 
mtvling  much,  or  at  rest  and  needing  little,  would  receive  thetr  ration  of 
IdiHM).  allotted  with  a  pernicious  monotony.  Just  the  same  amount  of  blood 
would  imns,  through  the  skin  i>u  the  hottest  lui  on  the  coldest  day.  The 
oaoon  of  the  life  of  «very  part  fur  the  whole  period  of  its  exittence  would 
he  funii.-*hed  by  the  inborn  diameter  uf  iia  blood veateli),  and  by  the  uuvaryiog 
motive  power  uf  the  heart. 

8uch  a  rigid  svslem.  however,  does  not  exitit  lu  actual  li\'inf;  beings.  The 
vascular  mf'hniii.'U]  in  all  imimabi  in  which  ic  is  present  is  capable  of  local 
and  general  modifKntiouM.  adapting  it  to  local  and  nocral  changa  of  cir- 
eiimetaiics.     Tbv»'  Ri»diticntir>n!<  fall  into  Iwn  great  duns : 

1.  Changes  in  the  bearl's  beat.  These,  being  central,  hareof  eoursom 
general  edbct ;  they  influence  or  may  influence  the  whole  body, 


Tttt  TASCCLAB    MECnANISsr, 


S'tl 


^ 


'2.  Cluuig«a  in  ihv  [icripboral  n«ii>iiiuc«,  <lut'  lo  varinttuii-a  in  the  culihre  i>l' 
Um  miootr  iiri«ri<«,  brouglil  abuut  by  Hut  agtacy  oT  tbdr  contractile  tnii*- 
vnlar  o<uit«.  TIk-m  ctuuigM  n»y  m  either  luca),  HfliM-tiuv  a  uarticiilar 
vawulnr  «m  uuly,  or  g«Dcnl,  iflectiiig  all  or  nearly  all  ihe  olooilvotitelt  of 
the  body. 

TIkm  twodaaMs  of  events  arechieHy  ^vernrd  by  the  nervoiu  «yMo(ii.  It 
it  bjr  BMUs  of  th«  iKrvouB  «\vtcn)  thnt  ibi:  h(-nrl'»  iHrnt  nii'i  llie  <.'nlibr«  uf 
iba  uiaiile  artcrice  iirc  brougiil  into  rolalioii  with  onvti  nlher.aDd  with  almoM 
•vcnr  ]art  of  llie  Wly.  It  in  by  mtviu  of  the  ntni-oiiF  »yntm  acting  cither 
on  lb«  heart  or  on  the  bdwII  arteries,  or  un  both,  Ihnt  a  change  of  circiini- 
wumrtB  aJStctinz  either  th«  whole  or  a  part  of  the  l>ody  is  met  by  compeiiwiling 
or  rt^litive  cliaOf^CB  in  ibe  flow  of  bloo<i.  It  is  by  nicaiie  of  thv  n^'rviius 
mytUta  lliat  an  orfcan  bu  a  more  full  supply  of  blooil  when  at  work  thitu 
wkeo  At  r«M,  that  the  tide  nf  blouil  (hroucli  the  sltiD  riaea  nod  ebb«  with  ihe 
riw  and  fall  of  the  tttiiiitralure  of  the  air.  thai  the  work  of  the  heart  ia 
leiapered  to  nieel  the  strain  uf  overfull  arteries,  and  that  the  arterial  ^•atee 
open  and  ihut  u>  the  furue  of  titc  central  pump  waxes  and  wanee.  The 
■tody  '-f  theae  ebaDgea  becotges.  therefore,  to  a  large  extent  a  study  of  oervoua 
■otiwtuL 

The  cimilaliou  otay  aim  hr.  iDmlified  bv  eventa  not  belonguig  to  either  of 
the  abow  two  Flamn.  Thug,  in  tbii  or  ifiai  peripheral  area,  Hianges  in  the 
otpillary  walla  and  the  walU  of  the  minute  artenea  and  veina  may  lead  lo 
■a  inciuw  of  tl>r  (vndencv  of  the  blo<Kl  corpuiK'Iea  bi  adhere  lo  the  vascular 
valll.  and  to,  quite  n|>art  from  any  cbnnj^  m  the  culihrt)  iif  ibti  bloudviawdf, 
nay  Wd  tn  increiue  of  iho  [icriplicrnl  n-nt^tanoe.  Tlii*  in  wen  in  an  exlrvni<r 
catc  in  influRimalton.  hui  may  puwility  mt«rvvne  to  a  Inic  extent  in  the 
unliuary  oiindilioD  of  Ihe  circulation,  anil  may  aVi  hd  un<h-r  the  inHum^v 
of  the  uervous  system.  Further,  any  decided  chan);r  in  tlie  (juantily  of 
blood  aclnallv  in  cirrulutiuu  0111.M  also  iolluencc  the  working-  of  llie  vasmlur 
mechanism.  Due  Ixnb  lhe»--  chaii),-<h^  are  unimportant  compared  with  tlte 
other  two  kindH  of  i-hiinun).  Hence,  the  (ho  nioil  important  problems  for 
u»  to  study  Hre,  I,  how  the  nervous  syiitem  re^ihttai  the  beat  of  tbe  heart, 
•ad  2,  buw  the  nervoui'  »yi>ti-in  regulateA  tlu!  cnlibre  of  ilw  bloodveasela.  Wo 
«t1l  Rrvl  conai)ier  the  fomter  problem. 


Tkf  llUtobtyi/  of  thf  Hrart. 

%  Ul.  It  will  b«  neccMary  dow  to  take  up  certain  {>ntnt*  coDcerning  the 
■ninute  ■tro«-((ire  of  ibe  heart,  which  we  hnil  previously  {loriponed :  ami 
■inct  much  of  our  knowle^))^  of  the  nervous  m«-hani"m  of  the  bent  of  the 
hisrt  is  derived  from  eK|>criiiH'Dt«  on  the  heartJi  of  I'old-bloodeil  animals, 
niorv  particularly  of  the  frog,  it  will  be  dciirabic  to  coniiiler  these  as  well  as 
the  mamnialiaii  heart. 

t  ittdi/t^  rnvteaiar  tisme.  The  ventricle  of  the  frog's  heart  H  composed  of 
miDMla  «}>il>d]e-«haped  Hbres  or  fibre-cells,  each  coninining  a  nucleus  in  its 
middle,  and  tapering  to  a  |>iint  at  each  end  ;  foinelimes,  however,  tbe  end  la 
ferfccd  or  even  hraneWd.  Tbeae  fibres  or  fibre-cells,  id  lact,  resemble  plain 
ataamlar  flbres  m\-«  that  they  are  somewhat  larger  and  that  their  nibtitance 
Is  striated.  Tbe  Mriaiion  ts  due,  like  the  strialion  of  a  striated  museic 
Ibre,  111  allvmato  dim  nnd  bright  ImmU,  but  is  rarely  so  dintinct  tis  in  a 
•kclrial  lihrr;  it  ts  very  apt  to  lie  obscurei!  by  (he  presence  of  dispersed 
dWtinrl  grttTmlfH.  which,  in  niiuiy  ciuat  ut  all  events,  are  of  a  fiuty  nature 
I.ikr  ihf  ptoiu  muscular  fibre,  the  ear<llae  miiHculnr  fibre  has  oo  dUtinet 
laroilenima. 

tn 


2 12 


THE   VaSOOLAB    MECQAKISH. 


A  number  of  ibcM  librim  nre  jninecl   bv  coment  MulkWiuiM  Eoto  rruII 
buniilcfl,  nnd  tl»i>i:biiiiclli.-a  are.  by  lh<-  belp  uf  CMiiucctivv  tittniv  which  cttrri» 
no  blood v<-«M!t>,  wuvon  into  an   intricnU^  network  or  sponge-woric,  wtiicll 
forms  the  ercnicr  piiri  uf  iho  null  of  thi;  veiilriclri.    Iraiii«Nlial«)y  uiKler  tb« 
pericArtlmfcnnting,  cuiMxliiig  of  n   Inyt-r  of  upiihclioid  pbilcs  restinj;  on  a 
couocclive'tisiur-  bnvix,  Llic  niuHciilitr  liscui;  fornit!  a  tbin  continuous  »b«ec.  but 
within  this  it  spread*  out  iQto  n  (jKiiigD  work,  the  iik'»)i<«  of  which  nreecDt  » 
labrrintli  uf  paMSg«s  continuoiii>  with  tho  cnvlly  of  the  Tentriclc.     Tlie  bars 
of  thiit  apon^fvwork.  varring  in  ihickncva  nnil,  llioiigh  ■p|>ni'cntly  irrejcutar, 
urriiu);ed  on  a  dutinile  erslcm,  congist.  uf  bundle*  of  niuHcubtr  fliir«A  united 
by  conuective  tissue,  and  nre  coated  wilb  the  same  (.'iidoeardial  lui-mltfane 
(Ant  epithelioid  plates  rvsiing  on  a  connective- tissue  basis)   that  liuu  the, 
cavity  of  tbe  ventricle  and,  indeed,  ilie  whole  interior  of  the  bean.     ThM 
cnviiy  of  tbe  ventricle,  in  other  words,  opena  out  into  a  labyrinth  of  iias-^iges' 
rciiching  nearly  to  the  eurface  of  the  ventricle.     When  the  ventricle  is 
dilated  or  relaxed,  blood  llowa  ft¥«]v  into  and  fllte  ihia  labyrinth,  bathing 
ibc  ban  of  the  apiin^  work,  which,  lu  tbe  atiHeuc^  of  eapillarirai,  deiH-rnl  mi 
this  blond  for  their  nouriahment.      When  the  ventricle  contrant*,  the  Moodj 
ifl  driven  out  of  this  liibyriutb  an  well  at  »ii(  of  the  central  cavity.     H«aeeJ 
tbe  vcDtricle  when  dilated  and  full  of  blood  i»  of  a  deep  ml  colrjr,  wbe4i 
oontmclod  and  empty  it  extretnely  pale,  having  littlki  more  than  the  color  of 
the  muKular  fibre*  ibemMlveH,  which,  likr  MrintiMl  fibm,  posKMi  in  their 
ovn  Rubetanco  a  aerttuii  amouut  of  hKnioglobin  or  uf  myohntmatin. 

The  much  ihiiini-r  wall*  of  the  nuricio  coii»i*l  "f  ii  mwcb  thinner  nctworU 
of  similar  libr<«  tmitti]  by  a  relatively  larger  i)uantily  of  connective  tiasilS* 
intOsUliD  Rhcvt,  with  the  jH^ricardinl  racnibranft  on  the  outside  »»d    tbe 
endooaidiaJ  membrane  on  the  insiilc.    The  fibres  bave  lo  tbe  aurieJe  a  much 
snater  tendency  to  bo  branched,  ntkI  many,  ecasing  to  be  spindle-ebaped^ 
Moome  almost  stellate.     Among  the  obscurely  stjiated  but  still  Mriated* 
fibm  are  found  ordinary  plain  inuBculnr  fibres  wbiob  iDcrease  in   relative 
number  along  the  roots  of  tlie  veins,  veme  cav%,  and  pnlraoDales,  until  at 
•one  little  diat^mce  from  the  be^rt  plain  muscular  mtn»  only  are  found. 
BloodviMiels  are  absent  from  the  walls  of  the  auricles  also. 

In  the  bulbus  arteriosus,  mixed  np  with  much  eoonective  and  elastic 
tinue,  are  found  fusiform  6bres  which  close  In  the  ventricle  are  tiriat^td  and 
form  n  thick  layer,  but  at  a  certain  diiilunce  fmm  tbe  ventricle  Iohi;  their 
Htriation,  or  rather  become  mixed  with  plain  miMculor  librw.  and  form  a 
thinner  l«j-er. 

S  163.  In  the  mammal,  both  the  veiilricltH  mid  the  auriclm  nra  (brmed  of « 
bundles  of  musculnniMiie,l)[)und  together  by  coiincclivc  tiMuc.aad  arranged] 
mora  etpeoially  in  the  veiitricl<«  in  a  very  comjilex  Jiys[«ni  of  aheeti  or  bundai 
diapOMa  us  spiraU,  and  in  othi-r  ways,  the  details  of  which  need  not  delaio 
ua.    In  the  auricular  appendices  and  elsovherc.  the  bundles  form  irregular 
networks  projecting  into  the  cavities. 

The  connective  tiMiic  binding  the  muscular  lihru'  togolher,  unlike  tbe 
oonespunding  connective  tissue  in  the  frog's  hciirt,  is  tvell  supplied  with 
bloodvessels  uolongiDg  to  the  eoronary  system.  This  cunneetive  tissue  fornn  i 
uu  the  inner  surface  of  the  cavities  a  continuous  sheet,  the  connective -tbdue 
baMH  of  the  flat  epithelioid  cells  of  the  endocardium,  and  on  the  outride  of 
the  heart  the  visceral  layer  of  the  pericardium. 

The  bUiologiea]  unit  of  these  muscular  bundles  U  neither  a  llbrc  nor  a 
fuiifunn  libre-oell.  but  a  more  or  lew  columnar  or  priamatic  nucleated  cell 
generally  provided  with  one  or  more  short,  bnmd  procebses.  [Fik.  ^0.]  The 
nucleus,  wlii eh  is  oval  and  in  general  rewmhlesoueofthenucleiuf  a^tnatcd 
fibre,  is  placed  In  about  tbe  mi<MIe  of  the  cell  with  its  long  axis  in  the  line 


TIIK    VASCDLaR    UECIIAKISU. 


248 


irvi  ai 


or  iiiK  Hurt,  a*»  ix  t  Uiwii- 
ti.'MMI.  MiTI»*,  On  ihr  rliU.  tfec 
limliior  ihc  KfaiBte  oslli  wiib  ibdr 
nutttl  an alilMlal  tonivwhal  <1la- 
KmmnMiimllT.f 


tt  Ibt  hmg  iliaiwur  of  ihe  «e)l.    The  c«ll  bixlv,  whicli  ie  iiot  boiiwled  \if 

WIT  ilefinito  Mrculcmmii.  ia  uriBl^l,  thauKh  uWureljr  ao,  8<iroaa  the  loDg 

diaiuKrf  of   t\tt  cell,  tlie   niHiiUuiu   an  in   ii 

•kakul  Btncltf  Itbn  btiiit;  ilm-  to  itie  sltenis- 

tioD  of  ditt  Uti  brigbl  ImikU.     A.i  in  iIk-  frott'it 

iMUt*  gnuiihw  an  tn^ioi-filly  nlximlniK.  olt- 

■ciiriiif  Ui«  •thxtion,  Mhicli  idiIm-iI  uvrn  id  th« 

ahMDOtof  gntRiitM  is  ntvor  to  ilimiiu-l  an  iii 

thm  6br?t  ul'  akrlvuil  idumIm.     Such  ■  ortl  in  ui 

«aeh  Mid  joined  hy  cemrat  wibstAtict  tn  »iinilnr 

fidli,  ■0(1   ■    n>n    of  i>ucb  cell*   mnfilitiilrK   ii 

cardtkc   <'li-ii><.'riliiry  fi)>rc.      Ilniiie,   s   cardiac 

6bf«MafibrvalriBtr<l,  hill  n'i(h<Hit  wircoloinina. 

■ed  diirided  by  partiiioni  of  ninviit  »iilNitaiii-i.- 

bibi  MHWK'lial  elon gated  diviMom  or  <-pll>.4-H<:h 

aMtaJniniE  a  nacleua.     Many  of  tlic  m*!!*  in  a 

flbra  faavo  a  ahon  broad,  lateral  proocos.   Su<!h 

m  [noma  la  unile«l  by  ceiii«Dt  mbetaiwa  to  • 

■iiallar    fuvii^eitt  of   a  coll   WIoDg;ing   to  an 

•djotniui;  libre;  and  by  the  union  uf  a  number 

4ir  t)M««  iTiK'fw.  a  number  of  parallel  librca 

■n>    loni»i'<l   into  a  ntnewhai   oIu«e  neiwork. 

flarb  iMimllr  of  ibe  cardia«  muscular  tinue  is 

titu*   itH-lf  a  Mtwork.      TiieM  bundlet  are 

tofthrr  woven   into  nelworictt   by  connective 

tianii  ID  which  nin  capillariai  and  lar^r  blood- 

vaaah;  and  ibiv-i*  <ir  b II ml lt« composed  of  auch 

Ol»Bfb  arc  nrriiii^o),  k>  w«  hare  said,  in  n  oomplox   manner  both  iu  llie 

auricle  sod   vi-nlriHo.     Heno.v  thv  tiiu»ciilnr  xtibilnniv  of  the   mammalian 

hnrt  is,  at  holl'im,  an  exceedingly  complex   notwork,  the  element  of  which 

iiBBMMwhat  branched  nucleated  »Inatoil  cell.     It  may  be  remarkMl  that 

■kf>**iilusculi  peclinati  "  of  the  auricle  and  the  "columaie  canK«"of  the 

*«a(ric)e    aoKK^t   t)ie   origin    of   the  mammalian  hearl  from   a   niuacuiar 

labrrtoth  like  thai  of  the  iroe'a  ventricle. 

At  the  eummencenient  of  tlie  F;reiit  arteries  this  peculiar  cardiac  muscular 
tiwiip  cmu>e#  abruptly,  being  replaced  by  the  ordinary  structurei  of  an  arlery, 
faai  tfae  stniiied  inuwular  nbrea  of  the  auricle  may  be  traeed  f>ir  mime  dis- 
uaea  along  both  the  venw  carte  and  reoie  putmoDalea. 

Uadar  the  endooardiuin  are  freaiieotlj  preaeot  onltnarv  plaiii  muscular 
flbrea.  and  in  some  ea«es  peculiar  cells  are  fuimd  iu  this  silualjon.  the  evils 
flf  Puricinj/-,  which  ure  inteiestiug  nmrpliologit'ullr  hecaose  the  body  of  tlu 
call  an>utid  the  nueleus  is  aniioary  elear  protO|>lasni,  while  the  outside  is 
•Iriatfd  (iilmtaiice.  Plain  miucular  fibrM  are  said  also  tn  iiiirrEul  from  the 
andof  rdium  for  a  oeriatu  distance  tni'i  the  aiiriculo-venlriruliir  ralves. 

I  US.  TKf  Hfrif  nf  the  hearl.  The  dintribiition  of  wrvca  in  the  heart 
Tarios  a  good  daal  in  diirereni  vertebrate  animali,  but  tirvcnhalMa  a  general 
fiho  is  HKww  or  Icm  eridunt.  The  vert«brnU-  limrl  may  be  r^ardad  aa  a 
■MPCfllar  tubo  (a  *ingle  tube,  if  for  the  monirntwo  diaregnnl  the  oonplexily 
«f  ■  double  circulation  occurring  in  the  highor  animals)  divided  into  a  series 
«f  obanibtrs,  sinus  venosus  (or  junction  of  great  vaitu)— auricle,  ventricle. 
■wl  bulbus  <or  mnus)  arterioHiSL  The  nerves  (with  thu  eioeption  i^a  small 
asm  whirii  in  some  animiiU  ranches  the  hoart  by  the  aorta)  outer  Ihe  heart 
al  ibe  voiMMa  end  of  (his  tube,  at  the  sinus  vonosus.  and  pass  on  toward  Die 
aitcina)  end,  dimini«htng  in  amount  as  tbuy  proceed  and  disappearing  al  the 
ODtuiect«i  with  tJie  iMin-e  6bra»  thus  passing  to  the  heart  are  group*. 


24-1 


TUB    VASCOLAB    UKCIIAIflBll. 


■mailer  nr  grvAier,  of  D«rv«  wHi^  Tbwe,  like  (lie  mm  fibres,  are  moat 
abunilaiil  at  tl>c  vctious  end  (uppMrlng  on  tin;  iK-rv«  branches  before  tlicw 
actually  mnvh  the  heart),  a«  a  rule,  become  fewer  toirard  ibe  nrlerial  end. 
Mid  finally  disn{)pear,  m  tlint  (aceordiog  to  mwit  (>b«erven;  at  tbu  bulbu* 
(oODUi)  artrriiieue  they  are  entirely  abMtt. 

Th«M)  colleclii>ii»  of  iK-rve  imiIIn  or  ennglia  may  ht  arranged  io  grou] 
aceonlin^;  to  tbeir  [toMlinn.  In  nuinv lower  vericl>ra(e0  tber«  b  a  i£at[D< 
riug  or  collar  of  gitnglin  nl  the  jiin<<tiiiri  of  the  8inu«  veiiosua  witli  tl»e  aiirielt^' 
where  the  prinuliTe  circular  di»p<uiti»n  of  muscular  fibres  is  mainiuiiiMl ; 
and  there  if  a  Hinilar  ganglionic  nillar  at  the  juiictjou  of  the  auricle  with 
the  veniriclc.  where  nlxo  there  \»  HiRiilarly  retained  a  circular  diaptMition  of 
the  muBciilnr  tibree  forming  ihe  so-ealk-d  mnaiit  nurieulari*.  And.  imleMl, 
iu  all  vertebrale*  two  similar  eotlcclions  of  ganglia  are  more  or  letn  iliatinctly 
proeiit.  There  are  ganglia  at  the  junclioii  of  the  sinue  with  the  aiiriek-  nnit 
along  tbe  entering  nerve  branches :  theee  maybe  called  ihu  oiiiuo  gaiifilia. 
Tliere  are  i>lher  ganglia  at  the  jiinclioii  of  the  auricle  ajid  ventrick ; 
may  hv  nailed  the  auriculo  vciiiricular  ganglia.  Ue^dc*  tll(«<^  Iwo  grou, 
tbcri!  an-  aim)  ganglia  overthe  auricle  in  cunneotion  with  nervtw  passing  frvim 
the  Mnu.->  l<>  the  veniriclc. 

IvHiitlv.aii  a  general  rule.  Ihe  main  nerve  branehea  and  the  ganglia  are  not 
plunged  dee]>  into  the  suItstaTice  of  the  bean,  but  are  placed  auperftdalljr 
immediately  u»d<'r  the  jieriiardial  layer.  From  the  eell.-<  and  nervw  so  eitu- 
nted  finer  brancheit  ami  lihrm  |iaH»  lo  the  ^bstanoe  of  ihe  lieart. 

til  the  frog  land  other  aniphihia)  llie  arrangvnicnt  ditlere  somewhat  from 
the  above  jilun,  and  therefore  needii  a  special  deacrijitiim. 

The  only  nervea  going  lo  tlie  heart  of  the  fmg  are  Ihe  two  vagi,  riKht  and 
left,  which  may  be  leen  niniiitig  along  the  two  tuporior  venoi  cavie,  and 
becoming  Ium  1u  view  at  the  siniie,  where  tliey  ihm  from  the  surface  tu 
deeper  part*.  Kach  vagus  is  not,  however,  simply  a  vagua  neire,  but,  im 
we  aliull  sec,  contains  tibroe  derived  from  tlie  splanchnic  or  Hyui[>atltetic  sj» 
tem.  Ae  tlie  nerves  appnwch  the  sinus,  gruups  of  nerve  cell*  becooM 
nbtindanl  ii>  ooniiectiun  with  the  fibres,  and  as  the  fibres  spread  out  nt  tb* 
dnus  many  ganglia  are  ocaltered  among  them,  forming  what  ia  emlled  •■» 
whole  the  o'liu^  rjitnijUon ,  or  the  'i<iHplio»  of  llemai: 

From  the  HinuH  the  two  vagi,  leavini;  iheir  po-<ilion  under  llic  [lericnrdium, 
plunge  ititu  the  heart  and  run  alon;;  the  bepcum  between  the  auricles,  on  ibe 
left  ndc  of  the  seuluni — one.  the  auleriur  nerve,  ptiniiing  near«r  th«  fnini  ef 
tlie  heart  than  the  other,  llie  posterior.  Several  gruu|Di  of  cells  or  small 
ganglia  are  cunncded  with  the  two  "  septal "  nerves  thus  pa»>ing  along  tlie 
acptuiii. 

The  nerves  reaching  the  auHculo-Tenlriciilur  ring  on  the  anterior  tide  of 
the  heart  end  in  iwii  ganglia  lying  at  the  \uun!  of  the  two  large  surKiulo- 
ventrieiilar  valvea. 

Front  ih<«c  two  ganglia  AiWr/crVf^oji^io,  or  the  i>iineiiya-t<eii(n'cM&iryaHj7/t>i. 
nerve  fibres  pass  into  ibe  suhstanco  of  the  vcniricle.  Nerve  cells  mar  t>e 
traced  on  tbc  (ibrm  going  to  Ibe  ventricle  for  oome  little  distance,  Imt  tot  a 
ItUle  difflnnce  only ;  over  the  emler  giart  of  the  ventricle,  the  lower  twu- 
ihirds,  for  instance,  the  nerve  6brfs  are  free  from  nerve  cells. 

Thus,  in  the  fro^'  ihero  are  two  main  ganglia— sinus  or  liemak'a  gangUoo, 
auriculo-venlrieulitr  or  Itidder's  ganglia.  From  lUe  former  there  pass,  on 
the  one  hand,  ^'altered  librcs,  in  connection  wilh  which  are  amall  groupt*  of 
oclb.  to  Ihe  auriculnr  vralls,  and  to  the  sinus  walls ;  and,  on  the  other  hiiod. 
llie  two  main  nerves  running  along  [lie  eepiitni,  tn  ciuinection  wilh  which 
are  omall  gaii];lia  which  may  lie  enlled  "seplul  "  gauuliu.  From  the  latter, 
Bidder*  ganglia,  fibres  uDaccompanietl,  except  fora  uTiort  distance,  by  nerve 


TIIS    VASCL'UAB     UKCflANISM 


24d 


I 


to  lb»  Mihttitnor  of  tbo  vrnlricle,  Hn<l  jxiwibly  to  tliv  bulliu* 

In  Ui«  mKmnial  tlw  nrmnf^Ricnt  nppeara  to  conform  nioro  cliwuly  tn  lh« 
gwni«l  plnti  dncribt-il  uliovv.  Tito  «i-vcnil  vtinlinc  ncn'n.  from  thp  HjinjiK- 
tbttio  cnun,  lo^etlicr  irilti  ttniiii-liM  frum  the  viigiis,  includtug  Hbrm  from  ilia 
rwomnt  Inrytifsenl,  rnrm  the  supcrlicial  and  deep  card iiic  plcxuMs  below 
•ad  beoeHth  the  urch  of  Ihc  aortx.  From  these  plexuora  fibres  nr«  dia- 
tribaied  to  tin  supenorveDB  cuva  nod  tu  the  pulniuiiary  veins,  and  thence  lo 
ttw  mrii>u«  jtmrta  of  the  lienrt.  Gaofflm  are  abundant  on  the  euperior  rena 
oiTM  and  are  also  found  on  lli«  pulmonary  veins,  in  llie  vralls  of  tne  aurielea. 
in  lh«  auric-ulo-veiilrieular  Kr<WTe,  and  in  the  bnaal  portion  of  the  vonlriclet; 
further.  aLxnrdiui;  to  wme  obserTers,  in  L-ontrast  m  the  fru;;'^  hearl,  u  num- 
bor  of  *mall  ^itn^lia  may  be  observed  over  a  \^rge  part  of  the  veiiindc  fur 
4oim  luKurd  ih(-  ajH-x.  Tbo  auricular  ^ptum,  nl  lea^i  in  iu  cunlrul  partt. 
id  fnv  fruni  jjaiiulia.  The  nerv««  and  gauglia  lt«  for  lh«  most  part  superli- 
ciailj  imnuiliatiny  undvr  the  pi-ricardimn. 

!■  i1h>  frog  th*  libmi  furmiii^  the  vagUK  nvrves  an  lb«y  nin  alone  ihe 
•Mfrior  TriUi  cSTiv  nrr  (-ompDwd  of  mtslullaU.il  uiid  n(in-m«dullntcd  finm, 
tht  lut«T  tmng  chifflr.  if  nm.  uhollv,  di-rivcd   iV'im  tho  iiilanchnic  or  lym- 

CktiMic  ■yatrni.  MMulUtwl  Hbn-*.  with  ■  larger  pnipirtion  of  non-iiiRduU 
I»tI  ffbmt,  an'  f"unil  in  tlir  g>'pliil  ni^r^'w  riinnlni;  In  BiddcrV  gnniflia.  but 
i1m>  fin«  fibtt-^  nhicli  (mw  from  Itiddcr's  ^iinKlia  to  llir  «ub«lunoo  of  ihe  tc«- 
l/ict«  an-  ficluMi-ely  nuniiK-d'illeilod  Son*.  Thi-  iicrvo  cells  Jn  the  siDtu 
(;■&«)*>  and  alou};  ih«  c«ds  of  (lit-  vagus  ii«rv(«,  us  wHI  ns  some  of  the  mIU 
cif  iJh>  ^ii;;ltu  M:Hlter«H  over  the  Kcpliim.  nr«  of  the  kind  prariituiljr  (§  96} 
dorriheal  as  iipirul  e«Itf.  The  coll$  compneing  Bidder's  Kunt^lia,  at  well  M 
maoT  nf  the  celU  in  the  seplum.  are  said  to  be  bipolar  and  ru^iiform. 

In  the  mnmmnl  tli«  fibret  puasinK  to  the  heart  are  al«o  meilullated  und 
afNi-Rir>lulIatr<l.  Some  uf  tlic  raedoUnted  flbrM  are  nf  Hne  calibre,  muy  Ite 
tracnl  back  to  thi^  vniciu.  ami  up|H.-ar  to  be  Rhn^  of  wliich  vrc  *liull  (penk 
nrcMinilr  a*  inhibitory.  (Ilher*  of  the  uiC'diil]nle<l  fibres  urv  of  larger  call* 
on.  aiM  sum*  of  tlxvK  at  ull  events  upiieur  to  be  aeiuory,  or  at  ti-aal  allcnut 
in  ftiBCtloti.  Of  till-  uon-mealullulvd  libres,  itome  may  be  lnui->l  luck  aloiig 
the  ccnlUc  ai'rvr*  |o  ihr  infmnr  rvrvicul  gnnzlion,  und  nri'  of  thv  kind  we 
»li«ll  speak  of  us  augnM-nling.  In  cmtnut  to  Uie  frig,  many  uf  thr  tibr<«  in 
th*  voairicta  (wlicro  thev  lie  rtufi'  itndt-r  the  pericardium)  are  mmlullatcd. 
■ad  it  b  probable  thai  tbrsi-  art-  uflVrenl  Hbrvf^ 

Tb«  eMf  (nrmiuji  the  rnrioii*  ganglia  XTUltCTed  over  tbo  miimmnlian  heart 
■nr.  pertu4«.  h^  elasMd  af  unipoliir  und  multipolar,  the  fi>rmvr  being  ape- 
ctally  mnn«oie<l  with  medulUted  libres,  the  one  cImm  being  praniincnl  in  one 
•bawon.  the  other  in  nuolli«r. 

TAf  liewlnfitneitt  of  the  Ntrrmat  Rfit. 

Tba  heart  of  u  miinirnal  or  of  a  warm  bliwitlvil  anininl  gvnemlly 
U>  h«M  within  a  fen  minutin  uftor  bviii/  rvmured  from  tb«  bwly  in 
tbr  iinlinnry  way,  the  liisirt*  of  nnwiy-born  animilii  uoniinuing,  liowcvvr,  to 
tvBi  for  a  tongvr  tittiv  ihaii  thiMp  of  adult«.  Hunee,  though  by  spcoial  pro- 
caationa  and  by  mcam  of  an  arltlicial  circulation  of  blood,  an  Nolatvd 
nuimmaliun  lionrt  wny  lit*  prnfcrvi'd  in  a  puUatin^  coudittoo  for  a  niui*h 
Inoyrf  linw;  our  Itnunli-il^i-  of  lb"  exarl  naturv  and  of  the  cniMU  of  tbo 
«anl(ac  l>«at  i*  ai  yel  vry  largoly  bavod  oti  the  study  of  tliv  hearts  of  ixild- 
htwtA^  animals,  wliich  will  conltQiio  tu  bral  tot  hours,  or  undc^r  fnvorablo 
<iiTt*iiaM(anoM  enit  for  d»y«.  aAer  they  havr  been  remiive<l  fMm  the  body 


w 


THK   TA8CDJ.A11   MKCBaKISM. 


witti  only  ordinary  care.  We  have  r*iisou  to  think  that  Uic  meclianixru  by 
which  the  bent  i«  c-arHcd  ou  varies  in  some  of  its  Becuodary  featurvs  ia  clifTer- 
em  kinds  of  animala ;  that  ihe  hearts,  for  insuin^e,  of  llie  eel,  the  snake.  lh« 
tortoiwi,  and  the  frog,  difTer  iti  some  minor  details  of  hehavior,  boili  finin 
Mch  othrr  mid  I'roni  the  hiril  and  the  luaintiial ;  but  we  may,  at  Gr«t  at  all 
evenlH,  tiikc  lh<>  hmrt  uf  the  fmg  iis  illutttnitiuK  the  nmiii  and  iinportsni 
truths  coiiocruiiig  ihi;  cuiiim  and  incchanisin  of  the  beat. 

In  HiucIyiiigclMely  the  phoiiomeiia  of  tliel>i-iit  vt  iLe  Iienrt  il  becoiives  nect«nry 
to  oliiaiti  a  grajihic  recurd  u(  vurtoiia  movrmnils. 

I,  [ii  tlic  (tQg  or  Dllirr  coldlilomlcil  nnimnl  ■  lii()it  IrTOf  may  be  plMvd  dirirctif 
on  the  vcntrtdc  {<>r  on  an  iiuricli'.  rlo.),  iind  ohurisn  of  totm.  due  eiUit-r  to  dislMI- 
lioo  by  th«  influx  of  blood  or  to  ihe  ivmole.  will  tuu»e  luovi-mcnts  of  Ihe  levw, 
wbicli  may  bo  recorded  on  a  travelling  tiirfncc.  The  «ame  mtlhods,  an  we  bavt 
•een,  may  be  applied  lu  tlie  nininmnlinn  hciirt. 

3.  Or.  nil  in  C.iiukcll'«  mrthod.  the  bntit  may  be  fixeil  by  n  clamp  rarerulty  ad- 
jiiatfd  araund  the  •uriciild-rcutricular  Krimve.  while  ihe  apex  of  tlie  Tcotricle  and 
aome  portion  of  one  aurii-le  are  attached  liy  ibrtiidH  to  liori/Antal  levers  placed 
respectively  nbOTc  and  below  the  lieatt.  The  anricte  nnd  the  ventricle  each  in  iia 
sVKlolc  piitlH  nt  the  Irver  attached  lo  it,  and  the  limea  and  eitrnt  of  Ibe  oonlrac- 
ttoni  niny  I  bun  be  recorded. 

3.  A  record  of  «ndo-cardiac  preaaure  may  be  taken  lu  the  frog  or  lorioise.  as  in 
the  tuauimal,  by  nieanH  of  an  appropriate  manometer.  And  in  tliose  animals,  at 
all  CTcnls,  it  is  cnsy  to  kec^p  up  sn  iiTliReial  circulation.  A  csnuU  i*  inimduvcd 
inin  the  oinna  reooKUs  luid  nnothrr  into  the  ventricle  through  llie  nurtn.  Seiuin 
or  dilute  blood  (or  noy  other  lluid  which  it  may  be  denired  ta  employ)  is  driven 
by  moderate  pressure  ibrough  ihe  former ;  to  the  latter  is  attached  a  tub«  con- 
nected by  meaos  of  a  side  piece  with  a  small  mercury  mnnometer.  So  long  a* 
tlM  exit-tabs  is  open  at  the  end  fluid  flow*  freely  throu);h  the  hriut  and  appaimlua. 
Upon  cloiiog  Ihe  exit-lube  at  its  far  end  the  force  of  the  vcniricular  systole  is 
brtrashi  to  bear  on  tha  muiomel4)r.  ibe  Index  of  which  reaisien  in  tlie  usual  way 
the  movements  of  the  mercarv  cotunin,  Newell  Msrttu  hu*  succeeded  In  apply- 
ing a  moditlcation  of  this  metliod  to  the  mammalian  lieiiri. 

4.  The  movcmenis  of  ihe  ventricle  may  bo  regipiicred  by  inirodueing  into  it 
IbrDUgh  the  auriculo-veniriculnr  orifice  n  ■o-called  "perfuiion''  ranuln,  Figs.  91 

and  'Jn  ].,  with  a  double  lube,  one  inside  the  other,  and  tying 
F^-91-  ibe  rentrlcle  on  to  the  esnula  at  the  aurfculo-voBtriciilar 

ETOOve,  or  at  any  level  bclon  that  which  may  b«  desired. 
The  blood  or  other  fluid  is  driven  nt  nn  udequate  prennurc 
ihtuLieU  the  tube  a,  outers  ibe  vi-oiricle.  und  returns  by  ihc 
lube  b.  lib  he  cuniieeied  with  a  niauometer  ss  lu  method  3, 
the  mnvemcnis  of  the  ventricle  niny  be  registered. 

&.  In  ihe  appnmtnsof  Itoy,  Fig.  92,  II.,  the  exil-tabe  is 
free,  but  the  ventricle  (the  luime  method  mny  be  ndonlcd  for 
Uie  whole  heart)  is  placed  m  an  airtight  chamber  filled  with 
oil,  or  partly  uilh  norniid  saline  si)1uii>>u  and  partly  with  oil 
By  means  of  the  Inhe  A  the  interior  of  the  chamber  a  is  ooii- 
linuoiu  with  that  of  a  tniiill  cylinder  e  in  which  a  pUloti  */. 
■erured  by  a  thin  tlexibli'  aniniul  membninc  works  up  ana 
down.  The  pislon  sgain  liesr^  una  lever  ebr  mean*  uf  which 
its  movement*  may  be  rcgiatcrcd.  When  Ihe  veulrlcte  con- 
A  PurnatDi  C*K\i.^  Iraels,  nnd  by  conlriicling  dimlni*he*  in  rolunie,  there  is  n 
letBCuing  of  presHure  in  the  interior  of  ihe  chamber;  this  is 
limitsmilied  to  the  cylinder,  nnd  ihe  pisioti  correspondingly  rises,  carrying  with  it 
Ihe  lever.  Aa  ihe  veniricle  suliMqiicntly  becomes  distended  the  pWMwre  In  ibe 
ekambrr  is  incicnsed,  nnd  the  iii*i»n  und  lever  (.ink.  In  this  way  varialiona  In 
the  volumu  of  the  vrntrirlo  mny  lie  reiorded,  wilhuut  noy  great  interference  with 
Om  flow  of  blood  or  tluid  Uirou't'h  it. 

The  heart  of  the  fro^.  as  we  have  just  said,  will  rontiuue  to  beat  for  hourv 
afler  removal  from  ihe  body  even  alter  the  cavities  have  been  cleared  of 
blood,  and,  indeed,  when  they  are  almoet  etupty  of  all  fluid.    The  l>eais  tlius 


M 


TIIK    VAMCt'LAlt    JIECllANtSH. 


247 


cmirird  out  ■!«  in  all  iiu|>»nant  rM|iocts  idcntiml  with  th«  l»rA1»«x«:uir(]  by 
th*  bout  in  iu  tiunn»l  coattittoii  wlthtu  the  living  ludv.  Hoooc  vn-  mity 
loftr  that  Ibr  litul  of  tlic  haul  »  ui  Mitmnutic  ■cti'iii ;  ihc  aiuHtiliir  mti- 
tiaciiaw  which  coiigiitiil«  lh«  beat  tre  due  to  ctiiiM-s  which  arifc  Rpunla- 
OMHMly  in  lh«  Itmrt  iueir. 

II  rw,  ta.  I 


t  MMiM  mute  tint  IMn  ItaCt  rmtili'lc     n,  «ntrmn<p;  b.«i](-lul«.   <  .  wall  oT  notriclt:  fi. 


KloTikpiMmlai  mulUM  br  lluklll.    a,  (kuDlnr  llUtd  wtlll  wIIik  •iiliillun  iiid  nil.  «cmlalii- 
llfc imiiWto  *  iMcntoforfUMoucaiiula/.   ti,iBbe1iadIiittooTllui]i'rc.liiHUtiIiiiiuTaplMan 

tn  th«  frog'*  honrt,  u  in  Uiitt  of  tlic  mnmnml.  $  I'JO.  ihrri'  it>  a  dirtioel 
iwftiico  of  tnrniU  which  ia  ihr  miik-  whi-ther  tlw  heart  be  removed  from,  or 
WniU  io  ill  normal  coodition  withiti,  the  body.  Fim  cone*  tlw  beat  of 
lit  MDus  Tcnoeiis,  precr<lr<l  by  n  titonr  or  !<■»  jhcriBisliic  «>ntnictton  of  the 
iirg»  wins  leading  into  it,  next  lbllon»  tlw  oharp  beat  of  the  two  auricles 
VfHittt,  then  otrmea  the  longer  benl  of  th<!  ventricle,  and  lastly,  lh«  cycle  ia 

■plated  by  tlie  beat  of  the  biilbus  arlerioeus,  which  does  not,  lilte  the 
Jiau  norta,  simply  recoil  by  elualic  refleli»n  after  diatentJOD  by  tb6 
_  'Jcular  Mrtike  but  canioa  out  n  diHlinci  muscular  contrMtJoD  pMeing  io 
iwtve  (htm  the  venlrii-tb  outward. 

Wbon  lb«  ii«art  in  dyiti^  oeosee  to  beat,  the  oeveral  niovenienta  ceuK,  aa  a 
mle,  in  an  order  the  inverw  of  ilic  alMve.  Omiltio];  ibe  bulbus  urteriosus, 
■  hkh  aometimtit  exhibits  i^real  rhyttiinioal  power,  we  may  say  that  first  the 
Ttatriole  faib.  then  the  auricle*  fuil,  and  htnly  (he  aiituti  vtmasua  ikila. 

The  heart  aAer  it  had  c«aaed  tu  beat  >ii>uniune«Mi»ly  n-tuainit  for  aoow  time 
iiritable — that  i»,  rapubk-uf  executinj;  a  beat,  or  a  ihorl  wTica  of  beata,  vbeu 
■tinulaied  cither  mcchiiDi rally,  a*  by  touching  it  wilh  a  blunt  iiccdlv  or  dec- 
Itiially  by  an  iixluciino  xhuclc  or  in  other  wav«.  Thu  artilii'iid  l>ont  to  called 
fcrib  maT  b«  in  Us  muin  feuturcn  kli-iitical  with  the  natural  Ih.'AI,  all  the  divi* 
■ioaii>r  tlie  ht-urt  taking  jiarl  in  ihp  tii-jil.aitd  ihom-iiucncxtol'evfni*  bring  tho 
an*  a*  in  th«  nntural  beat.  Thun  when  the  (inu»  in  |>riokvd  ihv  beat  of  the 
MBM  may  be  fdlluwnl  by  a  Wal  of  [he  auricle*  and  of  tho  vcntriclo;  and 
trtn  mhvo  ifaa  r«nlHcl«  u  Ntimu luted ,  lh«  dircrlly  following  boat  of  tlie  ven- 
liicl*  may  Iw  MeOM<l«d  by  n  i-omplrte  Iwat  of  tti<>  whole  heart. 

UacWr  nirtain  circumstADOoa,  how»v«r,  tiM<  divtAon  directlv  stimulaicd  ia 


246 


aUy  the 

pownrn 


tbe  onljr  III10  tu  Iwitt:  n-hrn  the  v<Milride  is  pncked  tbr  iustaiic«  it  kIodb 
beatii,  or  uhcn  thti  tinug  is  pricked  it  nirtiio  hcalK  T)ie  reeiilu  ol'  ittimiilBtioo 
moreover  may  iliR'cr  iiceordin;;  to  lli«  conditioD  of  ihe  bean  and  accurding 
to  tbe  niirliutilur  i|mt  to  which  tbe  etimulus  is  apfiliod. 

Wilt)  nu  incretising  Iusb  of  irrilabilily,  tbe  response  to  atiaiiilatioD  cmms 
ID  the  Kveml  divisioDs  in  tlie  sanie  order  as  that  of  the  failure  of  iIm  natunil 
beat — tbe  ventricle  cea««  to  respoiitl  drat,  tlieii  tbe  auriclai,  and  lasllv  tbe 
uiiuB  veoosufi,  which  frequently  reepundtt  to  slimulatiou  long  allcr  ibe  < 
divuious  have  ceased  to  make  any  »ij;ii. 

It  woiihl  ap}>ear  us  if  the  s'mu.^  veiia«u«.  euriclcii,  and  veiitriol«  fbrmedS 
d(MC«ndin){  ^ri««  in  rtf»i)>ecl  Ui  ihiiir  irriliibrlily  utid  In  rhr  [inwor  thrr  P«m4 
of  carrriii);  oti  MpiinianeiiUE  rhythmic  hcjil«,  the  »inii*  being  the  matt  pat«llf 
Thill  i»  aW  ^len  in  tbe  foll'uvrrig  exjMrimoiitK : 

lo  order  that  the  frog's  heart  may  hi--iil  iiA-cr  reinnval  from  the  body  with 
Uie  nwircKt  nppn>ach  in  rapidity,  regultiritr,  and  cndurancfi  to  the  normal 
c'ltidiiinii,  the  removal  must  l>e  carrictl  out  so  that  the  excited  heart  dill 
rotaiiiK  the  itntif  vcnwiix  inl.nrt. 

When  the  inciiion  is  corricd  through  the  aiirides  so  as  lo  leavv  lliv  sinus 
venoeus  behind  in  tbe  body,  the  rvaiilt  ie  dilferoiit  The  iiuut  vcnoeus  beats 
forcibly  and  n?giilarly.  having  Fiiflered  hanily  any  interruption  fmm  the 
operation.  The  excised  heart,  however,  remains,  in  the  majority  of  cases, 
for  some  time  motionless.  Stimulated  by  a  prick  «r  an  induction -sliock,  it 
will  give  perhape  one,  two,  or  several  beats,  and  then  cornea  lo  r«et.  lu  tiie 
majority  of  cases,  however,  the  animal  having  previously  been  in  a  rigorous 
condition,  it  will  after  a  while  recommence  its  »|K>ntaneoas  beating,  tlte  systole 
of  the  ventricle  following  that  of  the  auricles;  but  the  rhylhni  of  Iwal  will 
not  bo  the  same  aa  that  nf  the  sluiin  veuosaa  lefl  in  the  body,  but  will  be 
slower,  and  thi^  lieniv  will  not  coiitiuiKi  to  go  on  for  so  long  a  tiRx-  a»  will 
those  of  a  heart  mill  retaining  the  nnus  venosiis. 

When  the  incision  is  carried  through  the  aiiriculo-vtaitriculnr  groove,  so 
as  to  leave  the  auricles  and  sinus  venosu?  within  the  body,  and  to  isolato  ihs 
TCiulrlcle  only,  the  renult^  are  i^itnilnr  but  more  umrkeil.  Tbo  sinus  and 
auricles  beal  regularly  and  vigorously,  with  tlioir  proper  Mouence,  but  the 
ventricle,  after  a  few  rapid  contraclionsdue  to  the  incision  acting  as  a  stlinu- 
las,  generally  remains  f<>r  a  lung  time  (|iiie^oent,  W'h^u  Mliniulaled.  hoiv- 
vrer,  the  ventricle  will  give  one.  two,  or  several  beatn,  niiil  after  a  while,  in 
many  ciM^^  at  lea^t,  will  eventually  set  up  a  apootanenui  puUation  with  an 
Indeiwndent  rhythm :  and  this  may  Inst  for  some  couMidcrable  time,  but  tbe 
beats  are  not  ito  regular  and  will  not  go  on  for  so  long  a  time  m  will  those 
of  a  ventricle  to  which  the  aurioiea  are  still  attached. 

If  a  transverse  incinion  be  curried  through  the  ventricle  at  ahrmt  Ita  upper 
third,  leaving  t)io  hone  of  the  ventricle  still  attached  to  tbe  auricle*,  the  [lor- 
tlon  of  (he  heart  Irft  in  tin-  body  will  go  on  piil.-uttiug  rojiularlv,  with  the 
ordinary  setjuftncn  of  sinus,  nurides,  vuntricV,  but  tbo  iHvlatw]  lower  two* 
tliirds  of  the  ventricle  will  not  heal  spontanoously  at  all  hnwover  long  it  be 
U-tL  Moreover,  in  rt:>)>on«:  ^J  a  single  stimuhts  such  as  an  induction  shock 
or  a  Ktntle  prick  it  gives,  not  as  in  the  <-ni<c  of  the  itntiru  ventricle,  when 
sUmulaled  at  the  base  or  of  the  ventricle  to  which  the  auricles  arc  attached, 
a  serica  of  beats,  bat  a  simple  l>eat. 

Lastlv.  in  complete  the  olory  we  may  add  that  when  the  heart  t>  bisecteil 
longttuiiinally,  each  half  continues  to  l>eat  aponluneiKisIy,  witli  an  indepen- 
dent rliythni.  mi  that  the  beats  of  the  two  halves  are  not  iKCeaaarily  -vM' 
chronouH,  and  this  iMUiinuani'e  of  s|xinlaneo(tp  pulsations  after  longituiHnal 
bieet'tlon  may  be  SL-en  in  (lie  conjoined  auricles  and  ventricle,  or  in  the  iso- 
Intcd  auricles,  or  in  tbe  isolated  but  entire  venlriole.    MureoN-er,  the  auricle 


TUX   VASCULAK    UKCIIANISM. 


210 


imf  he  dividrd  in  many  wan  and  yet  luiny  of  lh<>  »0|pii«iits  will  r<iiilinutf 
bsiing:  unall  i>\w^  er«n  mmy  W  neen  iindcr  ibe  niit.-ruBCO)>c  |Milmiii);. 
fnUy.  k  B*  tmv,  but  ilMinclly  and  rhvthmii-nlly. 

b  thcM  expenmenu,  tl)«ti,  ili«  variouB  pariB  of  ihi>  fro^'n  Iwart  alw  form. 
H  rvnb  tmt  power  of  8|>oiiianeouB  iml^'atiou,  a  dncvnHins  serin:  siniM 
nSGN*,  •uncles  entire  ventricle.  lo«»r  jwrlioDs  of  Ttrn(ncl«.  Ilie  )ut  exhibit 
lif  asdtr  (irdinMr)-  circumBtuicM  no  B|)i-iniaoeauB  pulmlion^  at  all. 

i  IM.  Mow  we  have  seen  <§  i53)  tlint  these  parU  form  to  ■  certain  extent 
■  MDikr  (kaoatMlinf;  aeria  m  nyarJii  ihe  preaence  ofjianKiia :  ai  leaHt  bo  for 
tki  the  nojtlii  are  verr  numeroiiB  it)  ilw  itinuH  veoosus.  that  the)-  occur  in 
tW  Mrieles,  and  that  wliilc  Itiddur'a  f[0»)clia  are  preeuit  at  the  junction  of 
tW  mMride  with  the  aurM:l«^  ganglia  are  wholly  absent  from  Ihe  rest  of 
iW  natriele.  Hence,  on  tho  aMumplion  (which  we  have  already,  g  100, 
iwg  namm  to  doubt)  thai  (h<:  nerve  cflU  of  ganglia  are  aimilar  id  general 
AactiMU  I0  Ihe  nerve  rclln  of  the  ci-nlnil  ncrroun  «yMem,  ihe  view  very  nalu- 
aHj  pnaata  Etaelf  that  thr  rhrthmic  niHintani-ouH  heat  of  the  heiirl  of  the 
#•{  !•  doe  iQ  iImi  ■[HintaiMyHiii  pMicrali^^n  in  the  gaoglioDic  nerve  cells  of 
rlnllmie  imrfur  impulMii  which  puvitii:  down  to  the  niiMCular  Bbn«  nf  the 
Nnnt  pana  auMS  rhythmic  contnicti'<nB  of  (hrw  (!bn-«.  ihn  M-i^urncc  and 
aMioBtian  »f  the  beating  of  the  ■cvcriil  diviiinn»  of  the  hcnri  lifin^  the 
mAtoft  coiinlination  Wtwcrn  the  scvcnil  ganglia  in  n&gard  K"  ihe  p-nera- 
l^if  iBi|i<il«M.  Under  this  view  ihecsnliac  muKciilar  Itbre  Dimply  rrajiondt 
l<tbe  aolor  irii{>iil«ea  nsacfiing  it  along  ite  motor  nerve  fibr«  in  the  ■nmi-  war 
»  Um  •kel'-inl  maseiilnr  fibre  rmiMindi  to  the  tnnlor  iinpulsee  rcnching  it 
ilmg  ila  HNXor  avrvt'  tihrt- :  in  bolh  caaee  the  museiilar  nbrc  is,  as  it  wcrv, 
1  pMtve  inntniRM-nl  in  the  handf  iif  tbe  molor  nerve,  or  rather  of  the  nervous 
nain-  i  ganglion  or  spinal  cord )  from  which  ibe  motor  nerve  proceeds.  And 
ii»  Tww.  thus  baaed  on  the  fact  >if  ilic  frog'ri  heart,  ba*  benn  extended  to  the 
kaitinf  (vertebrate)  aaiiuaL<  generally. 
Tkrra  ai*  rvtwona.  however,  which  shmr  tlint  this  view  ia  not  tenable. 
For  laaiaae*,  the  lower  two-thinl*.  or  tower  ihini,  or  i-ven  lh«  mere  tip  of 
Or  frps'a  vcfltHolc — tluit  ijt  to  mij.  {Mrt*  which  are  ni)mitl<-d  not  to  onniain 
wr*e  etll*.  luity,  hy  R]iei'iiil  nieiinn,  l>e  indiicol  to  carry  on  for  a  coiiiidorable 
ttBsa  rhjcibmic  beat,  which  in  it*  main  fcHitir<»  ■•  iib-ntiral  with  ibe  'pM)- 
taaMoa  baiat  of  the  ventri<:lo  of  the  intact  hesirt.  If  mi-h  a  ]iiirl  of  iho  fnig'a 
nntride  be  tied  on  to  the  end  of  a  ]>erfii>ion  canuU  (Pig,  91 ).  the  portion 
•^  the  ventrinilnr  cavily  Monging  to  the  pari  mnv  he  sdei)ualely  disteiidei) 
Mil  at  ibo  *»itii-  time  l>e  "  fed  "  with  a  suitable  fluid.  «iieh  as  blo'^i'),  niude  In 
'ibmugh  the  eaniila;  il  will  then  be  found  that  the  portion  of  ventriclo 
atcd  will,  nfler  a  prelim  in  iirr  pi-rii>d  of  qiiieseeiice,  C!>mmence  to  boat, 
Rally  «[Htntaneniis]y.  and  will  continue a->  beating  for  a  long  period  of 
It  mar  be  sui<l  thai  in  this  ease  ibe  di^lentinn  of  the  cavitv  anil  the 
ily  of  hliKnl  or  other  tlutd  acts  a*  a  aiiniuluB ;  but  if  ao  the  stimulus  is  a 
'nuous  one,  or  at  least  not  a  rhythmic  one,  and  yet  the  beat  u  mnst  rega- 
'rhrihmio. 
Then,  apiin,  lite  reliictaiice  of  ibe  ventricle  to  rxenile  apontaneoii*  rhytbmic 
1 1>  til  n  certain  rxteni  |<oculiar  to  the  fro;.  Ttie  ventricle  of  the  tortoiiM), 
oManoe.  the  grenD-r  pin  of  the  MitMlancc  of  which  in  n*  tree  from  nerva 
I  a>  U  that  »f  the  frit^.  will  heal  iiiK)ninneogiily  ithen  iaolnttMl  from  iho 
I  nilli  grimt  turn-  ami  for  n  limv'  titni',  Kiirther.  n  mere  Htrip  of  tbi* 
ibr  niUK'ti'  ti»'.i'-.  ifki-pi  gi'iillv  e^ttcnded  and  Cixitinunlly  riioisteiiod 
I  hhmd  i>r  other  -iiiiabic  llnid.  Hill  e  inliniie  In  bmt  njnnlanoutly  with 
'irrral  rv^ulnrity  I'nr  bount.nr  cvi'n  'tiiv»,i-«|v>eiiillv  if  tli^-MriCM  bo  started 
b  pivliiiiinarr  application  of  ind>i<iion-flio<-lif  Hiythmtcally  repMtwI. 
fn  runnei-tiiKi  with  ihi*  >pir*iifiii  we  mar  call  atlenliofl  to  the  fact  that  the 


S60 


TUK    VASCri.AR    MECHANISM. 


cntvlinc  fUliiciilar  fibru  i*  not  wholly  like  the  Hkclvtal  lutttcular  i 
inanj  n^ped*  iIkt  niulriictimi  iir  lii-iil  of  the  fornivr  is  in  i1«  very  luilutc  <til'- 
fcrcnt  fivin  itic  coiilnictioii  of  thii  lutlcr;  ihc  Hinncr  canoot  be  coiisiderwi. 
like  the  laitcr,  u  mere  in«(runu-nt  in  the  hamis  of  lh«  nolor  nrrvc  (ihtv. 
TIm^  IV-jiturc  nf  the  bcitt  or  contrsclivn  -f  t^rdinc  mitfcW  mny  be  rtudieU  o« 
th«  isolated  mill  (luieccent  vcnlriclfl.  or  part  of  llie  ventricle  of  ihe  frue. 
When  HiK'h  n  ventrielo  is  stiniiilsteil  by  u  eingli.-  r<timulu«,  such  rs  »  HUgTc 
in  dilution -shock  or  a  single  louoli  willi  a  blunl  ni'edle.  a  bent  moy  or  may 
not  result.  If  it  follows  it  ivseiubles,  in  all  its  (■^iieral  feature*  »(  leaM.  a 
spontaneous  beat.  Ueiweeu  the  application  of  ilie  stimulus  atid  ili»'  firei 
appearance  of  any  coptraction  iu  u  very  long  latent  period,  varying  aecordiDg 
to  ctrouttistaDces,  but  in  a  viKiirous  iVesh  frog's  ventricle  bein^;  abouC  O.-i 
Mcond.  The  beat  itself  lastH  a  variable  but  vensideralrle  time,  rising  «loKly 
to  a  ntaxiniuiu  and  declininx  slonly  aKain.  Of  course,  when  the  bent  is 
reconled  by  means  of  a  light  lever  placed  uti  the  ventricle,  what  the  iradng 
altowfl  is  really  the  im-reai«  io  ihe  froni-io-bKck  diameter  of  the  ventricle 
durJDfc  Ihe  beat — that  in  to  say,  uoo  of  the  rciiilfn  of  thci  eonlnic-tion  of  the 
inrdiae  llhri'!' — and  givM,  la  an  indirect  manner  only,  the  cxt^t  of  the  cuD- 
traction  nf  the  filin-x  thcmM-Ivt-n ;  ami  the  Mime  u  the  cniie  with  the  oilier 
methods  of  rocorditig  ihn  mnveiD<:nli(  of  the  whole  venlnclc.  Wr  may,liow- 
cver,  study  in  a  more  direct  way  ibe  contrnclioii  of  a  few  fihrm  by  taking  a 
slip  of  the  ventricle  (and  for  this  purjioM  the  tortoise  i»  prefembh-  ti>  tlic 
frog)  and  siisiH^^ndiiig  it  to  n  lever  after  the  fashion  of  n  nnm-le- nerve  |)re|<*- 
mtion.  We  then  get  a  curve  of  eontraclion,  chamcterixed  by  a  long  latent 
period,  a  slow  long-conlioueil  rise,  and  a  slow  long-continued  fall— a  con- 
tmclinn,  in  fact,  mora  like  that  of  n  plain  muscular  fibre  than  of  n  skcJetali 
muscular  tibre.  In  the  tortoise  Ihe  contraction  is  particularly  long,  tlte  oon-' 
traction  of  even  the  skeletal  muscles  being  long  in  thai  animal ;  it  is  InM 
long,  but  still  lonu.  in  the  f'tog ;  sliorter  still,  but  yet  loug  as  compared  niih 
ihe  skeletal  muscles,  in  the  mammal. 

The  heal  of  the  ventricle,  then,  is  a  tingle  but  relatively  slow,  uiolon^ed' 
eonlraction  wave  Hwe«ping  over  the  iieculiar  cardiae  muHcIe-c«li,  paesiug 
through  the  cement  suiutance  from  cell  to  cell  idoug  the  Rbn,  from  Hbre  to 
fibre  along  thi;  bundle,  and  from  bumlle  t^i  bundle  over  the  laliyrinth  of  the 
ventricular  walls. 

Like  the  e«se  of  the  skeletal  muscle,  this  Mngle  contraction  is  accompanied 
by  an  electric  chung<r.  a  current  of  action.  The  intact  ventricle  Si  res*  Is,  a*, 
wo  have  nlrcjidy  Mid  ($  65),  iwK^leclric,  but  t«ch  pari  just  as  it  is  about  la 
enter  inUtastalo  of  eontriiclion  iH-oomes  negative  toward  the  mt.  Hean, 
when  the  electrode!-  of  a  galvnniiMn-ler  arc  phiccd  on  two  points,  A.  fi,  of  lb* 
•iirfaoo  of  tli<-  ventrirle,  a  ilijiliiihiv  variation  of  the  galvanomcler  needle  i* 
seen  just  a>a  U-ai,  natural  or  exc-iied.is  about  to  occur,  i^upposing  llint  the 
wave  of  eontraetion  reache"  A  first,  this  will  become  negative  toward  the  rest 
of  the  ventricle,  including  Jt,  but  when  the  wave  some  time  afterward  rmcfaei 
B,  h  will  become  negative  toward  iho  rest  of  the  ventricle,  inclading  A. 
Compare  §  fJT. 

The  beat  of  the  auricles,  thai  of  the  sinus  venosus,  and  that  of  the  bulbui 
Uieriosus  are  similar  in  ibeir  main  features  to  ihul  of  the  ventriule,  so  that 
the  whole  beat  may  be  consi<lered  In  be  a  wave  of  contraction  sweeping 
Uirough  the  heart  from  sinus  to  bulbus;  but  Ihe  arrangement  of  fibre»  til 
nich  that  this  beat  u  cut  up  into  sections  in  such  a  way  thai  the  sinus,  Iha 
auricles,  the  ventricle,  and  the  bulbus  have  each  a  beat,  so  to  speak,  to  them- 
•elves.  In  a  normal  state  of  things  these  n'verul  uart*  of  the  whole  beat 
follow  each  other  in  the  secjuciice  we  have  deM-ribtsl,  hui  under  abnormal 
oonditiona  the  seijueuce  nuiy  hi:  revcnted,  or  oue  rcclion  may  beat  while  tb< 


TnS   VASCCtAR    KECRAXIAU. 


2ftl 


or  Um  scverml  wclioiM  nwv  bcuL  out  of  lime  itilb  vach 


fe  fiir,  tko  dmcHpiino  nf 
tat  iliirm  fmtn  llial  of  a  «k« 


.Ibr. 

th«  c^nlrncliou  which  ia  lli«  fouoHfttioD  of  tlw 
k«Ietal  luiitcle  in  de)>ree  only;  but  now  oMnw  an 
b^rtuil  iliflereDM.  WIteii  we  tttiiuiitate  a  skeletal  muscle  with  »  strung 
Miuhia  we  fiei  it  \trg^  cnnimction ;  trbcii  we  apply  h  o'eitk  itliniulus  wc  gti 
■  *>ll  coDtraniiiti ;  uitliiii  certain  limits  (we  ^  7'J)  the  contniclion  is  pro- 
ptiiunal  to  i)ie  •limuhiB.  Tliis  isi  doi  thi^  chso  wiili  the  quiescent  ventricle 
It  bran.  Wheu  we  npply  a  »tnuig  imluction-ahiick  wo  get  a  beul  of  a  our- 
ma  Mjwagih ;  if  we  now  upply  a  wcitk  ubitck.  no  ^i  either  no  lieni  at  all  or 
q«W  U  •tnMtjt  >  beat  na  with  the  glroDgiT  riiiiiuluv.  That  la  lu  say.  tho 
■uniltidv  of  tbe  In'nt  <Ie[ieDd«  on  lli«  conitiiinn  nf  thi:!  ri-iiiricl«  'or  liearl), 
aitot  na  the  magniluile  of  U)c  itliniuliis.  If  Ihf  miinuliis  t:uii  viir  the  veit- 
tridf  i>p  to  l>eiil  at  all,  llut  brat  i*  ihr  Ihi>I  which  the  ventricle  lU  the  time 
aa  utitniplith;  the  ttimiilu*  either  proclucc*  it«  maximum  cfTcct  or  iinoe  at 
tIL  U  would  weni  m  if  the  stimulus  dow  iiot  pmOuco  a  oonimctiou  in  ihe 
«nir  war  that  It  doea  when  it  is  hmugbt  to  bciir  od  a  skdutal  niuoule,  but 
athrt  *ti»  up  tbc  be«n  in  Huch  a  way  os  to  enikble  it  to  execute  a  spon- 
tumuthnt,  which,  without  Ihe  extra  slirotilus,  it  couM  not  briog  aboiiL 
Aid  this  »  further  illustmtcd  by  the  fact  that  when  a  rcntrtdo  is  beuling 
rbnimiatlly.  eitlier  ■pMitaneously  or  as  the  result  of  rhythmic  «titDuluti<>n, 
ihrkind  of  sObcl  produced  by  a  now  etimuhis  thrown  in  will  dojieuil  upon 
ihianet  phnae  of  the  cycle  of  the  bent  at  which  it  is  thrown  in.  If  it  b 
ttnnt  in  just  m  a  relaxation  is  taking  place,  a  l>eiit  fullows  pram  a  lii  rely, 
Kdar*  the  next  btnt  would  naturally  follow,  this  premature  beat  being  obvi- 
miy  produced  by  the  siimuliis.  Itut  if  it  be  thrown  in  just  as  a  contraction 
i>  biglflniiig,  no  premalure  bt-al  followH;  the  ventricle  <toe£  not  seem  to  feel 
til  itimulus  at  nil.  Tht-rt.'  L->  a  jxnuil  •litriii};  which  the  ventricle  is  insen- 
■iUsloBtiinnIi,  and  that  hnwrvi-r  itnmg;  ihio  jKrioi]  ii>  cjillcrd  tlie"reA«0- 
period.  (There  in,  it  mny  Im  mentiuiml,  a  similar  ratVactory  period 
muscle,  but  it  is  of  cxceeilirigly  short  diimli[>n.)  From  this  it 
lliHt,  when  a  succowion  of  stimuli  repeated  nt  n  certain  rate  are  sent 
llie  ventricle,  tbc  number  of  beats  doca  not  corrcs|iond  to  the  number  of 
ttinuli :  H>mc  of  the  •limuli  foiling  in  ri-fractory  periods  are  ioeflcciive  and 
— Wc«  no  heal.  Hence,  also,  it  is  iliflicult  if  not  impotsible  to  produce  a 
tetanua  of  the  ventricle,  to  fiieo  n  iiuinber  of  beats  into  one.  And  tlier« 
■Olhtt  faclf  tending  to  show  that  the  contraction  of  a  cardiac  muscular 
ffven  when  induced  hy  nrtilicial  stimulation,  is  of  a  peculiar  nature, 
hat  the  analogy  with  the  contraction  of  a  skeletal  muscular  libre,  in- 
by  motor  im|HilM«  reaching  it  along  its  nerve,  does  nut  bold  gotMl. 

and  other  conf^ideratioiig,  taken  together  with  the  facts  already  nien- 
',  that  portions  of  cardiac  mitbcular  (istue  in  which  guiigHoiiic  celh>  are 
tfttaialy  not  prcseni.  can  in  vari'ios  animals  be  indiicni.  either  eawly  or 
•ttli  iliraralty,  to  execute  rhythmic  boats  w  hich  have  all  the  appearance  of 
bsiag  Hioalaneoiis  in  nature,  leiul  uh  to  conclude  that  tbe  beat  uf  the  heart 
BMI  ibr  mull  of  rhrthniic  impultea  pmceediu^  fruu)  tbe  cells  of  thi.-  ganglia 
lS|aMitc  muscular  tibrE«.  but  i^  mainly  tbe  result  uf  cluuiges  taking;  pUc* 
fa  tfca  moKuIar  tisane  itself.  Ami  here  we  inay  cnll  attention  to  tlie  |>eculiar 
Uulos^fal  features  of  cardiac  uiutcular  tjisue  ;  ih^Migb  so  far  diflerenliatad 
I*  In  be  striated,  its  cellular  ooostluition  and  its  "  pnuopluMuie  "  features, 
iKluHiu)^  the  obfcuritr  of  the  striation.  Dhow  tliat  tbc  diirereiitiation  ia  iucom- 
pbte.  Sow,  ooe  attribute  of  uuilifrrreniinti'd  prioionlial  protoplasm  is  the 
puerr  nf  •[■ontaoeouH  tnovciueni. 

t  U6.  We  have,  moreover,  evidence  that  it '»  the  ninsctilar  tissue,  and  not 
■W  amngeuent  of  ganglia  and  nerves,  which  is  primarily  concerned  iu 


biQl 


(nxlti 


fifi2 


TIti:    VASCltLAK    MKi'IlAN'ISM. 


ntniniaininj;  the  remarkable  neqtience  of  sluii^  heal,  aurictc  beat,  uti<t  tea- 
trick-  Ileal,  ThU  h  jwrhaps  l)yiter  seen  in  ihe  bean  'iT  che  lortwise  than  in 
that  of  the  fru)>. 

In  tliia  animal  llie  iiervea  paniiiK  IVom  tbe  sinua  to  tbe  reatricle  maj  be 
divided,  or  ibe  several  a*")?!'^  nm}'  be  re*(H!etiveIy  removed,  and  ret  the 
normal  ee<|ueiii'e  i^  maitiiuiiteil.  On  the  other  linni),  we  Dnd  that  inieriereitce 
with  tiie  museulnr  xib^tiinoe  of  th«  niirii-le,  whea  rnrrit-d  to  ii  otrtaiu  ext«Dl. 
prevents  the  bf  ul  ol'  ih«  uuricK^  pn-ttiiig  <ivvr  lo  ilif  veutricic,  hu  that  th<:*cqi)ence 
IS  broken  adur  ihc  niiricle  beat.  If,  for  inxLanw,  the  aiiriclt'  he  cut  ihrnusb 
until  oiily  n  narrow  bridge  i>f  iiniticl^  be  Irft  (.itiincL'tin^  the  part  of  the 
■nricle  adjoining  ihv  siniif  with  the  [Mrt  luljmiiinjc  the  aiiriculo-vcniriculu' 
ring,  or  if  lhi«  purl  Im-  C'iniprc»*(^d  with  n  clump,  a  Klutr  of  tbingit  maj  he 
brought  abiiul  in  ii  hifb  fvrry  sci-ond  honi  <inlv,  or  cvnrv  third  beat  only,  of 
the  *1DU«  nnd  nnriclc  is  followoil  by  a  bi'iit  of  tfic  vinitride  :  and  then,  if  th« 
bridge  bo  still  further  nurrowed  or  the  L-Iiimp  screwed  tiehl<ir.  ihi*  vcniricle 
doc*  not  nl  all  follow  in  ils  bent  tbe  'eqiiorice  of  ainiii  Hiiit  luirii-tc.  thmigh  it 
may  nftpr  a  while  eet  up  an  indeimndrnL  rhythm  of  il»  own.  This  ex|H>ri> 
meiit  I'liggwJ*.  nnd  other  facw  flnp|>nrt,  the  view  ibnt  lh«  normnl  »ei]"cnoe  it 
mainlninrd  ni^  follovvH  ;  The  beat  begins  in  the  sinuf  (incliidin)*  the  uuds  of 
thi>  veins) ;  thv  coniraction  wave,  bet;iniiing  at  the  ends  of  the  vein».  travels 
over  the  muscular  tissue  of  the  sitina,  and  reaching  tbe  auricle  starts  a  cun- 
trnction  in  that  iiegment  of  tbe  heart :  similarly  the  coniraetion  wave  of  che 
Biiriculnr  beat  reaching  the  ventricle  «tarU  a  ventricular  beat,  which  in  luni 
in  tike  fashion  ciana  tbe  beat  of  tbe  bulbu».  And  in  hearta  in  a  certain  con- 
diliou  it  is  pos^ble  hy  stimuluiioii  to  reverse  thin  sequenee,  or  lo  produce,  by 
alternate  stimulation.  lui  ulieruiition  nf  a  normal  and  a  reversed  aeqaeDoa; 
thus  in  the  heart  ofihe  «kate,  in  a  ocriain  conditiou,  meohanioal  slimiilatioD 
of  llie  bulbus  bv  iiidiaiting  a  brni  of  the  bulbu«  wilUtarl  a  sequenw  of  tb* 
bulkiiH,  TvnlHcle,  nnrielc,  and  Riuiin.  nnd  similar  ■liniulntion  '^f  the  ainnf  wilt 
produce  n  normal  fiequ^iipa  of  sinus,  ntiricle.  vcnlricli>,  tind  Imlbu*. 

It  nould.  pitrh»|)s,  be  prt-mntiirc  to  iiisjfl  that  the  m-rvous  vlenieiita  do  not 
Intprrune  in  any  way  i"  the  mninlunanuc  of  thi"  si.«|u<'ncc  :  but  the  evidence 
•howv  tliat  they  iirr  not  ihi?  main  fnctof,  nnd  we  have  at  prcwuC  no  snliifue- 
tory  iDdicntioiis  .)f  ihe  way  in  which  they  d"  or  iniiy  int«rronc,  » 

Two  iiuestion*  iialurnlly  Bugp?Bts  theniseK'ee  here.  The  lint  is.  Why  d'»ea 
the  cardiac  cvcle  begin  with  the  sinus  beat?  \Vc  have  pi\!vii>iislv,  ^  l->4, 
given  llie  evidence  ihnt  the  sinus  has  a  greater  poteiiliality  of  beating  than 
the  other  parts ;  iu  nnd  by  itself  it  heals  more  reiidily  and  with  a  quicker 
rhythm  than  the  other  parls.  When  wc  ask  the  further  question.  Why  baa  it 
this  greater  imlentialiiy  ?  the  only  answer  we  can  at  pivaeut  give  is  that  it  u 
inburu  in  the  subttance  of  the  (inns.  The  problem  is  somewhat  of  the  same 
kind  OB  why  the  heart  of  one  animal  hoaia  so  much  quicker  than  that  of 
amitber.  All  we  can  say  at  pn^eiit  i*  thai  the  rale  is  the  outcome  of  the 
molecular  constitution  of  liwuv,  without  Wing  able  lo  detine  that  uiul«culAr 
coMtituiiun. 

Till'  soonnd  •(itration  i*.  Why  doM  not  the  cnntrncliou  wave  starting  at  tbe 
ninua  spreiul  m  a  coiitinuonit  wave  over  thfl  whole  heart?  why  i»  it  broken 
lip  into  j«iuuK  Ix-al,  aiiricio  ImuiI.  venlriok  be*l?  We  may  here  mil  In  ndnd 
the  fact  inenliom-'l  iii  S  IM  of  tb^i  existence,  mon-  or  U««i  mnrki.'d  in  all 
hearta  and  well  m^-u  in  the  hciirl  of  tbe  lorlniae.  of  a  niu.<rular  rine  or  collar 
between  tbe  muii*  ami  the  auricle,  ami  ()f  n  ximilar  ring  hrtwecn  Ine  auricle 
and  v**nlrif|e.  The  muscular  tiwue  in  lbt»e  ring*  swim*  to  he  of  a  wmenlial 
diHvn-tit  nature  from  ihe  muHodar  timue  fortniiig  the  body  of  the  sinus,  or 
of  the  nuricle.  or  of  the  ventricle.  If  wp  suppnec  that  this  timue  has  a  low 
t-o lid II cling  power,  it  may  oflVr  oudicienl   rwialaiice  to  the  progren  of  the 


TUB  TASCt'LAR    MECHAXISM. 


25S 


I 


The  (Jiivemmait  of  the  tfetxrt-btat  bi/  the  Nervou*  SgiUm, 


ctAiruttun  lo  prrtoit  lite  «iDU»  ruri'SHmple  lo  cum  out  or  to  be  far  on  ia 
llw  dr% rln|)i»«iit  "t'ila  hcul,  bpfuretbe  auricle  be^iDs  \u  beat  (uiil  thus  bitect, 
•o  tu  tpmli.  tb«  Ileal  wbich  otJi«rwiee  would  bo  ooinmon  to  the  two),  atid  yet 
Dot  nflcr  ao  much  nftiatance  na  to  jirovpot  the  cmintction  nave  iMw&iDj;  ulli- 
■Mlalr  (A  from  ihi'  linua  to  ihc  auricle.  We  may  ia  the  tortoise  bv  carelul 
dUDptiie  or  Kctton  of  the  auricle  in  ila  middle,  by  which  an  obstude  to  the 
fantractiou  wave  ia  introiluccd,  bisect  the  eiiicto  auricular  beat  into  luo  Ifeiitn, 
OOB  or  the  |i*n  between  the  ftinuti  and  the  oluttacle,  aod  another  heluecii  the 
afa»Ca«:Ie  and  the  wotricular.  We  may  thus  coniuder  the  breakiujc  up  the 
priroitivv  uubrukeit  periualic  wave  of  o-iUraciiou  from  »i>ius  li>  bulTiuit  fi  he 
du«  lo  the  iti trod uc lion  uf  Iwtue  ul'  louer  (.-ouductiuf;  jiuwcr  at  thi;  Junction* 
mt  Hm  Mveral  pana. 

We  dn  tux  My  liiat  tbii  ia  the  coiuplcte  Mlution  of  the  nroblem,  but  it  Vt, 

Ht  oflkn  an  apiwnxlmate  aolutioo ;  aod  hen^  u.h  olaewlicra  we  haw  no 
Mtilfiwtary  vvinlence  of  nervou*  elenient  l>eiu)c  luaiu  facLore  in  thv  matti.*.r. 

la  the  above  wc  have  dealt  chietly  with  th«  heart  of  the  cold-blooded 
Miinal.  but  at  far  na  wu  know  the  tame  ouiicJuHoiis  hold  good  for  the 
aMmnaltiui  lieart  alto. 

Tbe  c|u«(iioti  iiow  arise*.  If  the  jpuiglin  are  not  the  prime  caote  of  the 
bctftn'a  rbrlhmie  t>eat.  or  of  the  niainleDance  of  the  normal  ee<)ueuce.  what 
parpow  cfo  iher  terve?  Rut  licforc  weevvn  itt(cn]{it  lo  nnxwer  this  iiucfllion 
m*  Mint  <]c«l  wilb  the  nervou(  mcchnnitms  by  which  the  Ih-hI  of  the  heart, 
tfaoa  sriaiDK  aponlaneously  within  the  tintjrs  of  the  heart  itself,  \%  modiSed 
umI  re^latetl  to  meet  the  rc(|iiircnK'iit8  of  the  r««t  of  the  body. 

^%  197.  Il  will  becooTCnient  lo  be^in  with  the  hcnri  of  the  fruj;.  which  u« 
>  have  teca  v  conotcted  with  lite  ecnirat  nervoui*  sytteni  through  aiid 
llwnrfbfa  govenied  by  the  two  va|^  nervits.  each  of  which  though  afipareotly 
a  liBSle  nerve  rontaint,  ae  we  »hflll  tee,  fibree  of  <liHcrciit  oriein  aii<i  natarc. 
If  while  the  beal#  of  th^i  heart  of  a  frog  are  being  carefully  rogi»tere<l  an 
ialcrtu|Aeil  uurrenl  of  ntoderutc  strength  be  sent  through  one  of  the  vaui. 
lb*  twa/t  ii  teen  to  stop  beating.  It  rcniiuns  for  a  lime  in  diastole,  perfectly 
■liliiiillrii  umI  iJacc-id  ;  all  the  niUKrulnr  libree  of  the  MVeral  cbaniberft  are 
fgr  tba  time  lii'iug  in  a  Hate  of  relaicution.  The  heart  has  been  inhililni 
Int  Umi  impuleea  devceodiug  dowu  the  vagus  from  tbe  jMut  of  tike  nrnrv 
Mnulatnl. 

If  ihK  duralioti  of  the  stimulation  be  shurt  and  the  mietigth  of  the  current 

t,  \\»«  •taiiddill  may  c^itiiinue  alter  the  current  hat  lieeu  abut  ofl';  the 

it*  abni  they  r<-ap|Mwr  arv  generally  at  fir^t  feeble  and  iafretiueiit,  but 

reach  or  even  i,"'  Iwyond  their  previouit  vigor  and  frei^uency.     If  tbe 

dnratioB  of  tlie  current  l>v  vtiry  h'og,  the  heart  may  recuninu-nce  heating 

vUklhe  rtimolntion  i*  Mill  going  on,  but  the  lHat>nre  leeblcand  iiitWguent 

ittMigb  sradually  increating  in  Ktrength  and  frcijuvncy.     The  vircrl  of  tbe 

Mtnolatloa  ia  at  its  maximum  at  or  tnou  aftrr  the  rommeuceuicnt  of  the 

spftlicBlioii  of  the  stimulus,  grudunlty  di.-('lining  afterward  ;  but  even  at  the 

(M  uf  ft  Very  prvilongi.il  stimulation  the  beala  luay  Mill  be  tew  in  fiircv  or  in 

ftVfatBCY,  or  in  loth,  than  they  wen  before  tli«  oerra  whs  stimulated,  and 

"■  the  removal  of  the  current  may  show  etgna  of  recover}-  by  an  iiK-reasw  iu 

toKe  and  fm|iteney.     Tbe  cfloct  is  not  produced  instantiuieoii!<Iy  ;  if  on  tbe 

emve  the  pciiiit  be  exactly  markeil  when  the  current  ia  thrown  in,  as  al  on 

Flit.  S'L,  It  will  fre<|ueDtlr  be  found  that  one  beat  at  least  occurs  afler  the 

timvni  ha*  pMr!«d  into  l^c  Dert'e  ;  tl»e  developmeot  of  that  beat  has  taken 


c: 


THS    rA8Ct't.AB    MKCRANI81I. 
place  before  itie  ia)|>ulM«  (ItMeiidiii)^  iIh-  vngiis  hsvo  b>H  time  to  ii^ct  tbe 

The  slitimlua  ne«<)  i»i>l  nciMMMtrilr  \>r  tho  interrupted  curreul ;  median icu I, 
ctieniieal,  itr  (hernial  mimiilutKin  ot  iho  vagus  will  also  produce  inhil>ilinn  ; 
bill  ill  order  lu  ^'t  a  iitnrki-il  ett'erl  it  it  lUwmble  tn  make  use  ut  not  a  singU 
iiervouainiuulte  bulascriM«rDervoiiB  irapulseB;  tlius  it  iadillieult  toobUiin 
any  recognizable  remit  bjr  employ ios  ■  Nnf;le  iiidu<-iii)tt-^b»ck  «f  niudoraie 
inteitnt^  only.  A*  we  shall  eve  later  on  "natural"  uerrous  impulses 
docendiiig  the  viigun  from  the  central  nervous  system,  and  staru-d  there, 
by  aHerent  iinpuls<v  or  otherwise,  us  jxris  of  a  reflex  net,  may  produce 
inhibition. 


«n 


ImWIMTMII  nr  KDUin    IIEIKT  Sr  STUtULjITKlfl  Or  VlGtS  NUVt. 

■IB  nwrlulliaUiiuM  wlikb  lli«tlRi«TTupial  curnni  «••  iliniuBlBioiIianRuat  qf  wlwnii  nit 
•liut  off.  Tlir  UtDP-nurkar  tvl'>«  msikii  Mniinili  Thi'  Uwtt  w«iv  r^l^•*tn•l  by  nnpcndlBS  Uw 
ventricle  rroBBClampUIMtivl  to  lticnurteinilalU(TlilD(a  lIcHI  leTor  lo  Ilu^Up  e<  Uw  VdiONte. 

Tlie  stimulus  may  be  applied )to  any  part  of  the<  courm  of  the  vagus  from 
high  up  iu  the  ueck  right  down  to  the  sinus;  indeed,  very  marked  r«Bull9  are 
oIitAiiiml  by  applyinc  the  electrodes  directly  to  the  sinus  where  as  we  have 
M«n  the  two  nerves  plunge  into  the  substance  of  the  heart.  The  Biiinulim 
ninr  aluo  he  applied  to  either  vagus,  though  tn  the  frog,  and  some  other  oiii- 
iiinU,  one  vagua  is  aometJntes  more  powerful  than  the  other.  Thus,  it  not 
unfre(|ently  hap|>cns  tJial  even  strong  stimulation  of  the  vagus  on  one  side 
praduoos  no  change  of  the  rhythm,  while  even  ntoderate  stimulation  of  the 
ni^rvi'  on  the  olhi^r  side  of  the  net;k  brings  the  heart  to  a  stand^ill  at  onoe. 

If  duriiii:  the  inhibition  the  ventricle  or  otlter  part  of  tht-  hnirl  Ix*  ntimu- 
lated  ilirc^ctly,  fur  inittanoe  mt.vhauically  by  the  prick  of  a  needle,  a  Wat 
may  fullon' ;  that  is  to  tny,  the  irapiil«ai  dectoiuiding  tli«  vafcus,  while  inhibit- 
inc  ihc  spontaneous  boat*,  have  not  wholly  abollthed  the  actual  irritability 
uf  the  furdiac  tiRHUc«. 

With  u  current  of  oven  moderate  inlemitv,  Kuch  a  current  for  ini^tAnoe  as 
wmild  produce  a  marked  totouus  of  a  muai-V-iiurve  preparation.  I  he  stand- 
still i;  complete,  that  is  to  say,  a  certain  numlwr  of  beats  are  entirely 
droppeil;  but  with  a  weak  current  the  inhibiciitn  i«  partial  only,  the  Iteart 
doe*  not  stand  absolutely  still  but  the  beats  arc  slowed,  the  intervals  between 
tlieni  being  prolonged,  or  weakened  only  without  much  blowing,  or  hnth 
slowed  and  weakened.  Sometimes  the  slowing  and  sonietimM  the  weakening 
is  tbo  more  conspicuous  result. 

It  Kinietimes  happens  that,  when  in  the  frog  the  vagus  is  stimulated  io  the 
nedt.  tlie  eflbct  is  very  diOerent  from  that  junt  deacriiMd;  for  the  beats  are 
iaoiMied  in  frequency,  though  they  may  be  at  6ret  diminished  in  force. 
And,  oocAiHonaily,  the  beats  are  increased  both  in  fon^  nud  in  frequency ; 


¥ 


TlIK    VAaCL'LAn    UKCilANlSM. 


S55 


iW  rvNiU  b  BuicnwatatioD,  not  iuhibttton.  Bui  this  !■  due  tn  tho  fnci  thnt 
a  Uw  ftw  the  va^^  alone  the  i^reater  {wrt  of  iu  nnirae  is  a  tuu«d  tierve 
■■4  onaiMiM  flbm  uther  tbnn  ibone  of  the  vhrva  jtja\>t^r. 

\  1S&  ir  we  eKHiiiiiii;  lli«  \amit  uvrve  cIml-Iv.  Irnciiic  it  up  tu  tlte  bntiii, 
*m  finil  ihni  jiul  as  ihc  nrrvi-  biu  iijvn.'ti)  (he  crsniiim,  jiidl  where  it  paasM 
IkfDVfti  ibe  gmngliuii  ( (i.  i'.  Pig.  Vi),  oertalu  fibn«  puM  into  it  Ctom  iba 

1^.  M. 


ftMMUitM'  RamauuiitrKm  n»  ra*  Ooomm  o#  CicutclAcianrrDB  rtiaci  ui  ths  Fm*. 

rAtmutir  t^»  lud  tiiftiMm.    I?. I'. gmgUiMi itf wt.   O.  Uii« oT onnliU  nil.   1^.  ncni 

VMt.   11.  uBiUi.  tli^tdi*t)»»iwl  nwTg.    A.rc  wpntor  mutjMnt.    %  ijaiikibatlc  iMrm  In 

■■fe.    «  r.  |«MrtUii  a<  iTinpalhFlIc  0tn/I1iiii  with  rttmt  ttntfifa  HDdlOf  l.r.  lutn  cnni*)  nliiw 

t  Mt  C— !«■  gingUna     Tbn  mi  -if  ilw  Dl.na  fmm  ftlaiiir  thB(TacTi>  mink     O'  aptitiif  biile 


I  wlllt  lb*  Sn>  (ptiwl  iiwvv-  </>ai>UnahBlrsia«ll(aior  UiaMQODi]  iiiiiial  imrc 
>K r  OToalw i>r  ViMaanft  Xi^ ■utoli«lin>(i«iT.  iT"' itiUnoliaic  fuifUaanf  iliu  ibinl  tiiiiutl 
■••<•    iit.  IhIM  •«<imI  a*n«.     r  c.  nmiu  (.■miiiiiviiluiin. 

Til  ■■III  lit  lh>a'i(inMili>cnhn«l«  ■tbmu  l>f  IIif  llilak  tiluk  llriv.  rtaer  m*y  bv  (laovl  tlvin 
••«■•)  «MdtTlb«aalalMi  nwlof  thcUilnl  ipliul  Mrn^thiousli  iba  mnu*  maunu&lcaiB  lii  Uw 
•w^imIIw  ff4M*ito  vwalloii  0<"  aiHa  Uhbm  l>r  tta  •Mond  laoallaa  O"  tba  •snulnc  trf  VIm»> 
■«Mi  Hw  Rnt  mKMiHi  47  (#  ift«  iwilntl  irmpalbiUc  .%*nd  n  by  Ibe n^  Uunlr  to  iln  wfvilor 

*TBpalbaiic  D«m)  uf  lite  Douk,  S3,  of  llie  rurlhar  ioufineotioiia  of  wbiob  w« 
tlwltpcak  pfOHotly. 

Ttm  }k'm$  tba  fluc^  w«  uay  expect  that  we  abuuld  set  infTerfut  nwilta 
MMnUi^{H  w«atiiniilatetH')il>fl  vaj^m  io  the  craniuiD  befur«  it  wan  )oiiii>d 


266 


rilK    VASCULAK    MUCllAMSM, 


by  lli«  ayiuputbeiic.  i^2]  tbe  lympathetio  fibres  before  tb&yjoln  the  voiiud. 
>»il  I  .i)  tho  va^iifl  trunk  coulaioiiifc  the  ronl  vn^uB  and  Ui«  BjnifMitbelic  fibre* 
adtlud.  Wbai  we  have  previousl,r  dwcribed  are  tlio  ordinary  resiili*  of 
aiiinutBliuK  tbe  mixed  iruuk,  and  Uieae,  an  we  bave  said,  are  uottibolty 
ooiiMiuit,  utuugh  UHually  and  in  tb«  maiu  moHl  distinct  inlubitun'  nsulu 
fulton . 

If  wc  Hiimidnle  Ihe  aym|iatbvti(r  in  llic  neck,  us  at  Si/,  Fig.  93,  cutting  tbe 
nervv  bolun,  >»>  us  U>  bluck  all  inijmlses  I'roiu  pajiiinjj  dowunanl.  aiid  uuly 
klluw  inipulieit  to  iitm  u|i  Id  ibi-  vuguti  nod  tb«DC«  down  tbe  mixed  vagu* 
trunk  U)  tbe  beurt,  vr<-  gi't  very  reninrkuble  reiulla.  The  beat  of  tbe  heart, 
iiwtcad  at  being  inliibiicil,  \i  aiigmcuted ;  iIr-  bcutt*  are  increaaed  either  in 
frequency  or  iu  fnrec,  ur  most  f^eiicrally  both  in  fr«<jUGiicy  and  in  form. 
Tbe  9tbcl  it),  [wrliap*.  Wnt  Men  when  the  heart  hvfure  nlimulation  i«  Ifeatiug 
elowly  ami  fiwbly ;  uixm  stimiilalion  of  ihe  ttrvic*!  »yDi]iathetic  tbe  b«at# 
at  onct  imjirovc  in  vigor  and  frcaiiwicv ;  indci-d,  a  fiwirt  which,  for  on« 
ntflwiu  or  Biiothf<r,  has  almnst  ccaeet)  to  beat  may,  by  profivr  vlimuintion  <tf 
the  symjiatbtrtic,  be  cnlk'd  back  into  vigorous  activity. 

If,  on  the  other  hand,  wvAliinulalc  iTic  vngus  before  it  bae  been  joined  by 
the  sympathetic  tibrcH  (and  to  insure  the  result  not  being  raairad  by  any 
escape  of  tbe  etimiiluling  curreni  on  U}  the  sympathetic  fibres*  it  if  noresmry 
to  atinmlate  (he  va^'us  within  the  cranium),  we  get  pure  and  cooslnnt  inhibi- 
tory resultii,  the  boats  arc  for  a  lime  wholl}'  abulisned,  or  are  slowed,  or  ar« 
weakened,  or  are  both  slowed  and  weakened. 

Obviously,  then,  the  heart  of  the  frog  is  supplied  through  the  vagus  by 
two  seta  of  fibres  coming  from  the  cenlrHl  nervous  eyatem.  the  one  by  the 
vagus  proper  and  tlie  othyr  by  the  cervical  sympaibelic nerve,  and  these  two 
seta  liave  opposite  and  ftntugoiiisiic  etlecta  ujiun  the  heart.  We  find  ujxin 
examiuatiiiu  ibat  w«  can  make  the  follotviug  utaiemenla  coucerning  them  : 

Tile  one  i>et,  (bow  belonging  to  the  vagun  pr()|ier,  are  inhibitory ;  they 
wcjikcn  Iht'  iiy»t<ilc  and  prolong  the  iliaelolc.  the  <-IIi.'ct  with  a  strong  stimula- 
liuii  bring  comjilcte.  so  that  the  Iicnrt  is  for  a  lime  bnmght  to  a  atandstill. 
Hometiinoi  the  slovring,  eomotimes  the  weakening  is  the  more  prumincriiU 
When  the  nerve  and  the  heart  arc  in  good  condition  it  needs  only  a  slight 
stimulus,  n  wenk  ciiirvnt,  lo  produce  a  marked  effect ;  and  it  may  l>e  meii- 
tioned  tbnt  the  more  vigorous  the  heart,  the  more  rapidly  it  in  beating,  tlie 
easier  i*  it  to  briii];  about  inhibition.  Alth^nigh.  us  we  have  said,  the  effect 
is  at  its  niaiiiuiim  a»on  after  the  beginning  of  stimulation,  a  very  prolonged 
inhibition  may  be  j>rodueed  by  prolonged  stimulation  :  indeed,  by  rhythmi- 
cal stiniulaiion  of  the  vagua  tbe  heart  may  be  kept  perfectly  quiescent  for  a 
very  louj{  time  and  yet  beat  vigorously  u|n>u  the  cca&ation  of  tbe  sUmalus.  In 
otiier  wurdH,  the  mechanism  «f  inhihitiou^lhat  is,  the  fibres  of  the  vagua 
and  the  |iart  or  tiulHitauce  of  the  heart  u[ion  which  these  act  to  produce  infaibt- 
tion,  whati-ver  that  jiart  or  Aiibstanee  may  lie — are  not  readily  exliauaicd. 
Further,  the  inhibition  whi-ii  it  cauva  in,  Vre'iiiently  at  all  evenly,  followed 
by  a  period  of  rencli»n,  (luring  which  the  heari  for  a  while  beats  more  vig- 
orwisly  and  rapidly  than  bcror*'.  lnd<:cd,  the  total  eftect  of  stimulating  tbe 
vagus  fihrvs  is  not  (o  ex  hau:<l  the  hnart,  but  rather  to  strengthen  it ;  and  by 
repealed  inhibitions  cnrvtiilly  adminialervd,  a  fcubly  )>vatiug  hcajt  may  M 
nursv<l  into  vigi>raus  activity. 

The  other  set,  tb<Mc  joining  tbe  vagus  from  tbe  synipnthctic,  are  "  aug- 
mentor"  or  "accelerating"  fibres:  tbe  latter  name  is  the  more  common,  but 
Ihe  fbnner  is  more  aecumte,  since  the  effect  of  stinnihiting  these  fibres  is  to 
increase  not  only  (he  rapidity  but  the  force  of  the  beat;  not  only  b  tlie 
diastole  shortened,  but  the  systole  is  strengtbeoed,  sometimes  the  one  reauli 
and  sonMtimes  tlie  other  being  tin  nor«  prominent.    In  contrast  with  ttie 


THE   VASCDLAR    MECQAtflSH. 


25T 


I  of  the  ragu*  fibre*,  ■  numcnhiitalroOKitiiTiiiliilioii  J*  rt<iuim3  to  nrcMliice 
»a  effett  :  ih*-  lini«  retjuirvd  fur  tltc  mnxTniuiD  eHucL  to  lie  pnxlucira  w  also 
tvmarkatiU  lun^.  Moreover,  Ht  all  event*,  tn  ilie  cuM  of  a  heart  in  vhkh 
tb«  ctrrulntttui  i#  not  mnintaiiK^),  nnd  wliich  i»  therefore  cut  olf  from  it» 
ounumi  nulrilivc  diipply,  tlir  MUciTM'nior  tibrv*  nr>'  far  !««■  etinilv  ■■xhnii«ted 
tiuui  arr  th<*  inhibitory  Abnt.  tinnv.  when  in  fiich  H  heart  ooih  Uti  of 
fibnw  are  Miniulatcd  together,  a*  when  ihv  vngiin  trunk  in  the  Deck  m  ttlma- 
Ut«tl,  Ow  6nt  rfle«ls  prochiccd  nrc  thiwe  of  iRhihitJon  ;  bill  tbiwv  on  cxm- 
linuetl  ttiroalatioti  mar  become  miicil  with  ibiMe  uf  auffmcntiilioii.  nnd 
fioallv  the  latter  alon«  remain.  Lottly.  the  contmst  it  oompletml  by  iho 
fart  thai  the  auf;menlAlion  re»iiltii)j;  from  the  slimutaMon  of  the  ermpathetic 

■  m  fella«ed  bv  »  period  of  reaction  in  vbich  the  beats  are  feebler  ;  in  other 
wwda.  aiigioeotatiun  n  followed  by  exliaustion;  aiu),  iDileied,  hr  repeated 
atimalation  of  ibcM  rrnpntlielic  fibres  a  fairly  vif>DrouB  bloodleaF  ^ean  may 
bv  reiluoed  to  a  venr  ieeble  coiiditiou. 

By  waiching  the  eifecU  uf  atirotilMing  the  sympatbetic  uerve  at  various 
poiata  uf  iu  coune  we  may  trace  thew  nugmeDtor  fibrw  from  their  junction 
wilk  Ibe  Tsgiu  dowu  the  abort  aympalbetic  of  the  ueek  ilimujib  ilie  first 

■  apjanchnic  or  aympathctic  ganglion  connected  with  the  fint  «ninal  nerve  IV' 
< rig.  94 >,  through  one  or  both  the  loofw  of  ihe  iinnulua  of  Vieunieii*.  .4m. V, 
duoagb  the  Mcood  ganglion  cw)niii>cted  with  tlie  i^cond  npinnl  nerve.  &", 
to  tk*  ibinl  gM^lloa  cooiMctvl  with  third  »pinal  itcrve.  fw'",  and  theuoe 
thraagk  Ibe  nuniia  nMomiinican*  or  viM^'ml  branch  of  that  ganglion,  r.c, 
to  lb*  tblrd  apjiud  nerre.  III,  by  the  anterior  mni  i>f  which  itiey  reach  the 
apioBl  oora. 

I IW.  Both  aeti  of  Bbrc*  may  then  Ixi  traced  to  the  oentml  nervous  ays- 
nm :  ud  we  find  aoconlingly  ihul  the  hfArl  may  be  inhibited  or  augmented 
Wdcttoim  inpuUee,  which  are  Marled  in  the  nervous  aystem  either  by 
mMmvot  tmpulaes  as  part  of  a  reflex  act  or  otherwise,  and  which  paaa  to  the 
basft  by  the  inhibitory  or  by  the  augmenting  tract. 
Tbo*.  if  the  medulla  oblonjjata.  or  a  particular  part  of  the  medulla  oblon- 

C,  wbicfa  ia  apecially  connected  with  the  vagus  nerve,  Iw  «timulaicd,  the 
t  i>  iiibibiied :  if,  for  iiiMance,  a  needle  be  tnrutt  into  this  part,  the  h««rt 
ataocU  aiill.  Tliia  region  in  qutMion  may  be  stirred  intoaitiun  in  n  "  rt-tirs  " 
■MUMrbvaflcreni  impulses  reaching  it  mim  various  pnria  of  the  boily.  Thus, 
tf  tWabJoiDenof  a  fri>gl>e  laid  bare,  nnd  t!i«  intetitine  Iteslnick  nharplywith 
lb*  hftodlv  of  a  tcwljnl.  the  lituirt  will  Miuid  Mill  in  dianlolc  with  all  the  phe- 
BWnWMi  iif  vafcus  iohibiliun.  If  the  ncrvi  metenUriei,  or  the  connections  of 
tbM*  nerves  with  the  spinal  ooni,  tie  stimulated  with  the  interrupted  ciirrvnt, 
euttiao  inhibition  is  similarlr  prodm-cd.  Tf  in  these  two  experiments  both 
f«gi  an>  (livi<led,  or  the  tncoullR  obh'ngatn  i*  dwlroyol.  inhibition  is  not 
{wmhohI.  however  much  either  the  inlcHtine  or  the  mesctiteric  nerves  be 
rinBulaled.  This  shnws  that  (he  phcnomeim  arc  caiuwl  In*  impiiUes  asc«nd- 
tiif  along  the  mesenteric  nerve*  to  the  inealulln.  and  to  alleclinj;  n  portion  of 
tiuil  r>f|:ao  as  to  give  rise  l>y  roflci  action  to  impulses  which  descend  the 
nfi  as  inhibitory  impiil*es.  The  jwrtinn  <if  the  medulla  thus  mediating 
Wwntp  the  atlercnt  and  eSerent  impulses  may  be  spoken  of  as  the  rardio- 
UkOiik  ry  er^iln-. 

1ts0ex  inhibition  through  one  vagus  may  be  brought  about  by  stimulation 
flf  tbe  c«Dtral  end  of  the  other.  In  general  the  alinienlary  tract  seems  la 
dner  niooection  with  the  cardio-inhioitory  centre  than  other  parts  of  the 
hdy :  and  if  the  peritouewl  surface  of  the  inieslioe  l>c  intlnmed,  very  gentle 
MMalalion  of  the  inflamed  surface  will  produce  marked  inhibition.  But 
a|ifiarratlv  Ntimuli,  if  stifBciently  powerful,  will  through  reDex  action  nro- 
■loee  inhibition,  whatever  tie  the  ]hu-1  of  the  body  to  which  they  ue  appned. 


26S 


TIIK    VASCUI.AB    MECIIAKISU. 


Thu»,  LTU^tiin^'  a  frog'ti  foot  irill  Atop  the  heart,  and  ailequKte  MimuUiion  of 
niofit  ulIbrv'Qi  iicrvea  nill  prcdiice  some  aniounl  ul'  inliibiiian. 

TIte  detaila  of  tlie  reflev  ehiiin  ati<l  the  portion  of  the  i-entro  oonnnm)  in 
itie  iJerelopment  of  augmenting  iiTi|)ulM«  have  not  been  worked  iml  so  fullr 
an  in  the  cnse  of  inlilbiCdrv  im|>ulM.'».  hut  there  can  b«i  lit(l<-  iloubl  that  lh« 
former,  like  the  liillt-r.  are  govL-riied  by  thi;  (.'ciiLnil  imtvuuh  hvtU-wi, 

i:I60.  Si>  t'lir  we  buve  bi-en  deullnft  with  thr  heart  of  the  fmg,  but  the 
main  fad>>  wbieli  nx*  bavc-  eljiied  re^rding  inhibition  and  nugmcnintion  of 
the  lifurt-heiit  a|i|>]y  hIbo  to  other  v^iebrntc!  nnimaln,  inchiding  mnminak; 
and,  iixleed,  wo  meet  similar  phenuntciia  in  tlw  hcorla  of  invertebrate 
aniuinhi. 

If  in  II  mammal  the  ht-Art  be  esnnacd  to  vieir  by  openinj^  the  thorax,  and 
the  vngnN  nerve  be  t'timtiliile'l  in  tnc  nrek,  the  heart  lony  bo  se«n  (o  stand 
still  in  (linstole,  with  all  the  pari*  flaccid  and  nt  rest,  if  the  onrreni  em- 
ployed  Im-  twa  weiik,  the  result  a«  in  the  frog  m  not  an  actual  arrest,  hut  a 
Hlowinc  or  wenkeninf;  of  ihc  beaU.  If  a  liuht  lever  be  placed  od  the  heart 
a  graphic  record  of  the  i^tindetill  or  of  ihc  slowing  of  the  complete  or  incoai- 
plcte  inhibition  mav  be  obtained.  The  reaiilt  of  etimnlating  the  vaguti  is 
also  veil  »howii  on  the  blood  pressure  eiirve,  the  eflect  of  complete  i.'arHiiie 
inhibition  on  blood-jireeanre  oeing  most  striking,  If,  while  a  traeing  of 
nrlerinl  picture  is  being  taken,  the  beat  of  the  heart  be  suddenly  nrrmied. 
eome  fiuch  curve  oh  that  represented  in  Fig.  96  will  be  obtained.     It  trill  Ih.- 

riu.  Mk 


TaxrnmSaov\%n  Jilt  lvn.va«!ti or  CtMHMi  tsHontioK  ■>!■  Bino)>*yu»nmx.    Fnut  a  EUarnr. 
I.  Ihr  maiKt  oil  ilip  ilgnul  lino  w)i*n  Ih«  current  !■  Itiruwii  Intd,  niiil  y.  utiut  olT  tmm  Iha  niftii. 
nui  UuiC'iuukct  bBlaw  mnrb  Koniili,  Ihe  htmrt.  lu  it  CKqucMlf  thv  eao  In  tha  nbMt.  Imbubc 

obaenred  that  two  builn  follow  the  application  of  the  current  marked  by  the 
point  a,  which  currenponds  tu  the  signal  -r  ou  the  line  below.  Then  fur  a 
apace  of  time  no  heals  at  all  ore  aeeu,  the  next  beat  b  taking  place  alinuit 
inimediiilely  al\vr  ibc  Hhuttiug  off  the  current  at  y.  Iiumediately  oiler  the 
Wt  lival  fotliming  a  there  u  a  sudden  fall  of  the  hlood-preeeure.  At  thv 
pule*-  due  tu  Lh<!  Iiwl  fvstiile  the  arterial  ti\->tt-in  la  ill  itja  niaxiiuuni  of  diirieu- 
tion  ;  j'firthwith  the  eliiaiic  reiii'tioR  of  the  arteriid  walls  pi'opels  tlie  blood  for- 
waid  inlu  the  vein*,  and,  ihere  Iwing  no  fresh  lliiid  iiijci-Ied  from  the  heart, 
ihe  fall  of  the  mercury  in  unbroken,  being  nipiil  al  iirwt,  but  alower  afterwanl, 
w  llie  elsnic  force  of  the  nrtcriid  wall*  u  more  and  more  uiwd  up.  With  the 
reluniing  beats  the  preMuru  corresjnndingly  riac*  in  encccwive  leMpa  uuUI 
the  normal  mean  preasura  ia  regained.  The  sii»  of  these  rvtumiug  leapt  of 
the  uiereury  may  seem  dispronorlionalely  large,  but  it  miMt  be  remembered 
tliat  by  far  the  greater  port  of  the  force  of  the  (trat  few  strukea  of  the  heart 


TIIK    VASCULjIB    IIKCUAKIISU. 


969 


I 
I 


r 


m  mimmIwI  En  dbuodiog  the  artvrU]  sjsl«in,  s  rrisII  portion  <Hily  of  tlw 
blima  whieb  is  «j«<4vd  into  iW  urteries  paoring  on  into  th<i  vriiu.  A*  lh« 
aruriAl  prcwnre  ri»M,  rioiv  niid  iiiun-  blood  pamm  at  «-HL-h  I>«hI  through  the 
eapiHann.  and  the  riae  of  tho  prtaaure  at  each  bent  bwomcs  Ivts  aim  Icbh, 
until  at  Ia«t  the  whola  maUota  of  the  ventricle  poM  it  eneh  stroki-  into  the 
win*,  ajxl  the  maaa  arminl  preMurv  is  «tablishcHl.  To  thi«  it  may  Iw 
•ddcO  that,  aa  we  have  ttVD,  tiw  force  of  the  individual  bcnU  mar  he  eom»- 
what  greater  aft«r  than  before  inhibition.  Bcaider,  wlwo  the  raerc^irrmano- 
laKer  ■•  uacd,  the  inertia  of  the  mercury  lends  to  magnify  the  rffects  <il'  the 
initial  beau. 

In  the  mamma]  mhibition  may  be  brought  about  by  iiDnuteea  paseing 
•iuog  flbra  which,  starting  io  tlie  medulla  oblungats,  run  doirn  over  the 
ragiM  nerve  and  r«ach  Ibe  heart  by  tlte  cardiac  nerves.  Ii  would  appear. 
bowvrcr,  tfaat  the  iuhibilor}'  fibn^  do  not  belou);  to  the  villus  proijer,  but 
lean  Ibe  central  nervous  sys[«ni  by  Ibe  suinal  avi-essary  ner^'e.  Thuit  if  the 
RWO  of  tb«  »j>iuai  tuxeaaary  be  divided,  tnoie  of  the  va«us  proper  being  left 
tntact.  the  «pinal  acoeaury  likrea  tn  the  vagiDt  trunlt  iKgenerate,  and  when 
this  laka  place  »tiniulaiiou  of  the  tu^ud  trunk  faila  to  product;  the  ordiiinrr 
inhibilitrr  rlTectii.  In  th«  manimni,  a*  in  thu  frotc,  inhibition  may  bu  brought 
ab>Mt  nik  imly  by  artificial  ntiinulation  of  thr  voguK  trunk,  but  by  tiliniula- 
tioo  in  a  redcx  manner  or  othvrwiiic  of  the  carilio-inliibilorr  oe.nlre.  Thu.t 
Um  fainting  which  often  follow*  ujwn  a  I>low  on  th«  »toin»cli  ix  a  repetition 
nf  tlM  rvult  just  nientioned  u  obtained  on  the  froc  by  striking  the  stomach 
or  atimulaung  the  oerri  roeMntcrid.  Ho  also  ihr  fninting,  complete  or 
partial,  ithich  ncoomnanics  teTare  pain  or  mental  emotion,  is  an  illustration 
nf  <»nliac  inhilntion  by  tho  vagus.  In  fact,  cardiac  inhibition  so  far  from 
baang  a  uiera  laboratory  experiment  entera  rcpealcdiy  into  the  erery-ilay 
trorkinK  of  our  own  organism  as  well  as  that  of  other  living  bdogs. 

Indee<)  there  is  some  reason  fur  lliinkiuK  tbal  the  eentral  nervous  system 
by  means  of  the  cardiac  inhibitory  ttbrea  keejM  as  il  were  a  coniiuual  retn  nn 
tM  heart,  for,  in  the  dog  at  least,  section  of  both  vagi  causa*  a  quickening 
of  the  heart's  beat. 

In  lb«  dog  the  atigmentor  llhres  (Fig.  96)  leave  the  apiiiul  con.1  by  the 
aotrrior  roots  of  the  second  and  third  <lorta]  nerves,  ])owibly  aba  to  some 
extent  by  the  fourth  and  liftb,  jitua  along  the  rami  (ummunlcanles  of  those 
Bervsa  to  the  ganglion  >tcllatuRi,  fir^t  tlioracic  ganglion,  or  respectively  to 
saa  or  other  of  tho  ganglia  forming  [mrl  of  tin-  thoracic  .iplandinio  or 
vvnpathrtic  chain  immediately  below,  and  thenco  upnanl  through  th« 
aonolu*  of  Vicuiwvns.tnuiiug  along  one  or  other  or  L>oth  loo[)«.  to  the  inferior 
Mat kal  ganglion.  Tneir  further  course  to  the  heart  i*  along  the  nerve* 
sprini^ing  oiDwr  from  the  inlbrior  corvical  ganglion  or  from  the  loop  of 
Viaiaaens  dim-tlv.  Their  exact  path  from  the  ganglia  in  fact  teem*  Io  vary 
ia  dlSrsnt  individuals. 

Tbe  path  of  the  augmentor  fibres  has  not  been  worked  out  »o  fully  in 
•Unr  BMmnuila  as  in  the  dog.  but  it  is  moat  probable  that  in  all  ca^es  they 
bare  the  sninal  cord  by  ihe  anterior  roots  of  the  ^cond  and  third  donal 
aarres  <  possibly  also  by  the  fourth  and  tiftJi)  and.  pawing  up  tbe  sympathetic 
ehaia  to  ilie  gaoflion  stellatuni  and  annulus  of  Vieussens,  proceed  to  tho 
bout  by  nerves  branching  off  IVom  some  part  or  other  of  tbe  annulus  or 
froai  tbe  lower  and  middle  cervical  ganglia. 

Tbe  oflbcts  of  stimulating  these  augiueutor  fibres  iu  the  mammal  are,  tn 

MMral,  the  aame  as  tliuse  witnessed  in  the  frog.     In  the  mammal  us  in  the 

tnf  Iraplilars  along  iboN;  augmentor  fibre*  may  \>t  ur^innliHl  in  thi-  citilral 

1  nai  I  inn  srstcin,  and  that  pr<>biibly  in  various  waySL     That  jialpilaiion  uf  the 

1^     bnrt  akich  is  so  conspicuouii  an  efled  of  cvrUiin  emotiono  is  protmbly  due 


2ao 


THE    \'ASCL'LAR    MEC1IAN18M. 


to  the  aiiddeii  poeilive  boUod  of  augmmling  impulH«.  thuuj^li  il  ma;  poadbljr 
be  rlue.  lu  pari  at  Itinst,  to  snddMl  wtthtlrimni  of  iiormat,  coDtiouoiM,  tonic, 
luul  inhibitor}'  impulses. 


IiixiHiMiaaTii'  KiTtiJannimoK  or  laa  cui> 
iirjiL  iHiriiiiioBV  t>o  Atjoatma  Pibnb 

!!•  TUK  IXKI 

II1B  upper  poitioii  of  Ui>  titan  npnasnU 
U>g  InhltilLoiy,  tbfi  lower  l)w  wisnuDior  Abrai, 
T.Yv.,  raotaoT  the  new;  rJip.Xe..  rcnu«if  Um 
■l^nitl  ncrauory:  boUi  drawn  •my  dhjft 
iDfttlullr.  (iJ.RaiiRllos  jnsulan:  u.Tt.Vc-. 
^[ikIIuu  tniiii'l  ngt :  ^p-Af.,  i|4iib1  amnwy 
liunk  :  Kxl J1|i.  Ar  .  cilmuil  ipliuil  w  c«»i.ifT  j 
ISr><Ac..  Iniemal  (plnalaucnaurr;  Vr.,  tnink 
of  v*tiu>  iivrvB :  11.'',,  bninchBiiroliii;  lolinut-. 
C.lji)r««rtlMlt}mi«thi!«li<:  (i.C  Inner  cwrvt- 
Ml  vuigUoD :  X.tb..  futwlavlan  arury  ;  Aa.V, 
JUmiilluor  Vtmmam:  O.W. >Tb.<),  fUfUoB 
■fcllatum  or  am  ihoiulc  ssdrIIoo  ;  U.Th*. 
n.Th.'.  o.Tb.i.  Hcond.  tbltis.  kiiil  latinli  Ik^ 
raiUccttnilla:  n.II.,  [>.I11.,  I>1V.,I>  V.  Mcond, 
Ihltil.  fbnnb.  uid  nnii  ihcirnr)cii4iAlDtrr«>: 
ijt.,  TKiDui  cummuiilnuu :  n.v..  ii«na  Kal>' 
dlacj  lawlnt  10  licatl  inipeitca  raoa  M**) 
fraoi  nrvlnl  (uigUbti  unl  Itoui  tlic  uinuliH 
of  V'leaaciui 

Tlw  labltdtoTT  flbra*,  Aowa  hf  lilncl  Ilnr. 
run  In  Ui«  iipp«  imtduUur  tnuu.  <a  ibo 
■l*nkl  ■cotMOty.  b;  the  Inlenwl  bnacb  of 
itiu  >4>iniU  kMKaiory.  |M>t  ibe  MnRMoo  Iranel 
vuKi'  iiliiug  Iho  iRink  <■(  Uin  nKiu.  kud  M  by 
limncbn  la  ihc  lUperlar  nna  can  aiul  Uw 

Till'  >iii|(in>'ii|i)r  nbm.  alfo  •hown  t>r  tdMk 
line.  iBH  [n>iii  (Iwiiidiuileoidli)'  ibeuMstor 
Kvit^uF  Ettr  *4<i-i*ijii  Aiiii  ihjnl  ihara^c  nfrrvn 
.jitHiilily  ii\f  rroin  itoiinii  and  anii  u  In^i- 
.'ndfl  ti>  brukiii  black  lliio).  paai  the  Mwoil 
uid  i)t>i  tHiollHivi  thoracic  (■iiirlla  tiy  tli»  u^ 
iiiilut  III  VlsuHriB  l«  Uia  lowrr  nnlokl  tu^ 
rUuii.  0(1111  wbtncc  m  kIm  (kuni  tb*  uioulai 
ItwK,  thrj'  lan  alnng  llw  cartlac  ntrro  ta 


In  tlio  RiunmBi  tben  as  in  the  hog,  (lie  heart !»  g»vciti«<t  bjr  two  fels  uf 
avntt,  tbi>  on«  ■nlagonietic  to  the  ol]i«r.  lii  the  dug  llic  moU  of  tl>o  «j>insl 
ncixetoTj  Dcrre,  bf  which  inhibitory  &bn»  leave  the  (X-ntntl  nervous  sTsiem, 


TBK    VASCl'LAR    UKCIIAM8M. 


Amoog  tbwe  are   fibres  of  line 
be  usom)  linwa  the  tniok  of  the 


^HHJ^^BbUrIj  of  medullated    fibres. 

raguB,  ftkmji  tbr  hnin<-b«9  t:iiinf;  to  tbe  bmrt,  right  i)i>w»  to  tbe  beart  ilself. 
TImk  mn  Kb  llUle  doubr  tbcit  Hicse  rootultiitoi)  fibm  of  line  calibre  are  tbe 
inUbilorr  flbm  of  th«  va^nia,  noil  inilr<^l  Un-n'  \»  evitlenoe  whicli  r«uders  it 
pmliable  tbit  tin:  iiihihUorv  tibra  of  tb«  bi-nrt  arr  nlwByi>  metlulbted  fibres 
«t  fiM  CftObrf,  H  liHi  cuntiiiiif  a«  modulUtiil  librr#  rif;l>t  ilown  to  the  beart, 
bat  •waltnllf  loao  thtir  medullx  in  th<<  hrnn  itM-IC. 

Tb«  nucrior  root*  of  tbe  tocond  nti'l  thin)  ilorMl  iMin,'m.  nod  the  (ithiu) 
tmal  eofDraanicanla*  belonging  to  th«Di.  which.  a«  n*u  hava  jtwt  swa.  contain 
ia  th»  dog  augmenlor  fihrw,  alsci  consist  osclnRively  of  mod  u  I  lit  led  lihita. 
Bat  tbft  n«rr«s  which  convcT  tbe  augmenting  inipuJK*  finni  tbo  |nin>r 
carTifJ  noglion  or  from  the  anuuluB  of  \'ieiiMcn9  to  the  bmrt  coniuM  of 
aott-KiedallaMd  Sbra,  Hence,  the  augmentor  fibroe  must  bave  lost  tbdr 
Mtdulla  and  become  contiitaouii  with  non-medullnle<l  Rhnt  somewhere  in 
tWr  cuurw  alontc  the  ivinpathetic  cbaiu.  It  \a  probable  that  the  chnng« 
oecan  in  tbe^'anj-lion  Bt«llaliim  aiid  lower  cervical  x''>')Rfion,  and  it  i»  further 
probable  that  thi-  ihant^?  L->  cfll^-ied  \>y  the  mediillato<l  fibre  pna§in|;  into  one 
flf  Ibagaoitlioti  celU,  ami  Bvluing  ita  meilulla,  the  iuipul»cfl  which  it  coorova 
pMriDK  out  uf  the  nerve  oell  by  one  or  more  of  the  other  procewn  of  tM 
e*ll  wftkh  ar*  oontiiiuad  on  as  non-mrdiillHti'<l  iibres.    Cf.  §  t»*. 

la  lk«  dog  then  thcM  two  sats  of  ni-rvc  fibn«.  antagonblic  to  each  other 
to  function,  difler  in  Mnicture,  lh«  atigmi-iitor  Kbres  early  lonng  their 
Mtdulla  and  heneo  being  over  n  large  part  or  lh«ir  course  mm -medu listed 
flbna.  wbrmu  th<-  inhibitory  Hbrea  are  in«lullat«d  fibres  whit;h  lluiu^b  they 
may  paoa  b^  or  Ihruiiub  g«iiglia  (as  the  ganglion  jngularc  and  (.-un^liou 
tmoci  rasi)  do  not  lose  thfir  medulla  in  ttiwc  ganglia,  but  remaiu  aa 
■srdullalea  librts  right  down  to  tlie  heart.  And  this  dinereooe  in  Ktructnru 
afpeara  lo  hold  goo*)  for  all  muniinals,  and  is  possibly  true  for  verU-bratcs 
fUkermlly. 

I  in.' Tbe  qnflKkn,  what  i»  the  exact  nature  of  tbe  change  braught  about 

by  tbe  inhibitory  aud  augmenting  impnbfti  reamctirely  on  their  arrival  at 

tbe  beanT  or,  in  olhor  word*,  by  virtui^  of  wliat  events  nroflnccd  in  the 

beait  itself  do  tbe  tmpuUvs  of  •>iic  kind   bring  alKiul   iuhibition,  of   the 

StlMr  Itiad  augmentation T  b  a  very  difficult  one.  which  w«  cannot  attemtit 

to  ill  can  ftillv  here.     We  may  if  W  please  «]wak  of  an  **  inhibitory  mecli- 

ttimm  "  nlui-il  in  the  ht-jirt  itMlf,  but  we  bavo  no  exact  knowledge  of  ihe 

aUan  of  such  a  mecluuiicm.    dtill  los  do  we  powow  any  wittiitactor>-  inform- 

•lioa  ■■  lo  am  augmenting  mechanism.     It  has  been  »ugge«t«l  that  Mme  of 

tbe  paglia   in    the   heart  serve  as   such  an    iiihibibiri-  (ut  augmenting) 

■KUtusm ;  but  there  ia  evidence  thai  the  inhibitory  impulses  prnduee  their 

•Am  by  aettng  directly  on  the  muscolar  fibres,  or  at  all  ovenu  do  nut  pro- 

daca  tbsir  e^ct  by  acting  exdiiaivelv  on  any  ganglia.    One  evidence  of 

this  jttftd  is  sapplieil  by  tbe  action  of  tne  dniji  atropine. 

If,  eilher  iu  a  frog  or  a  mammal,  or  other  animal,  after  the  vwub  ttbree 
Wic  br«n  pn>veil  by  (rial  to  produce  upon  Kitmulation  tbe  usual  inhibitory 
efct*,  a  ■mall  quantity  of  atropine  be  intnKlnced  into  lite  circulation  Cwlien 
ih*  •iperimsot  b  conducted  on  a  liviii);  animal,  ur  be  applied  in  a  ncalc 
snlutirai  to  (he  heart  iiiK^lf  when  the  ex|ierimeut  b  eonduoted,  a»  iu  (he  i-*»e 
ofsftif.ua  an  oxi-iiaHl  l>eart  or  after  ilie  rircu)atioD  baa  ceased),  it  wil)  al^er 
a  4wt  tinve  he  fotind  not  only  tliai  the  Hlimiilution,  Die  application  of  a 
cnrmt  for  inMance,  which  previously  when  iipplii-'i  to  the  vagus  produce"! 
Barktil  inhihilion  now  producci  no  inhibition,  but  even  thai  the  i>lr(inmi 
NiSNilu*,  the  strongest  current  appli<i)  to  t)io  villus  will  wholly  faif  to 
sftvt  ibe  heart,  provided  thai  there  tw  no  0Ma|>C  of  mrrent  on  to  the  cardiac 


•>62 


THE    VASCCLJLIt    ITl 


tiMUM  ibvmsdvts ;  under  the  inHtioncs?  of  even  n  nnall  iwv  of  ntro))in?,  ibe 
BtrongM  slimulation  of  the  vngii>s  will  not  p^^duc«  ilaiiijslill  or  npprcaablc 
slowmg  ur  weakening  of  the  k-nl. 

Hon  it  tnighl  be  suppoeed  thut  the  atropine  producer  this  remnrkable  etTwt 
by  acting  on  some  gnngliooic  or  other  mecbanism  intervening  belive«n  ibe 
va(;uB  librei  and  ihe  cardiac  muscular  tissue:  but  we  have  evidence  that  the 
atropine  acts  either  on  tlie  muscular  tiaeue  itself  or  on  the  verjr  eodingB  of  the 
nerves  in  the  muBcnlar  fibres.  We  have  said.  §  155,  that  a  properly  prepared 
Htrip  of  tbe  venlricle  of  the  tortoise  will  execute  for  n  loii^;  time  spoutAiteoua 
rhytbiuic  contracliuns.  it  will  go  on  "  beating  "  for  a  long  time.  A  strip  of 
the  auricle  will  exhibit  the  same  pheaoiueini  even  etill  more  retidilv.  If  now 
while  auch  a  strip  froui  the  auricle  ie  saliafnctonly  beating  a  f^utle  inter- 
rupteil  Diirrent  he  pan^t^l  through  It,  it  will  Htop  U-ating ;  tbe  current  iuhibits 
the  s|)ciu[aiieoui  beats;  a  very  j^itle  iiiternipKit  curn-^t  mu>l  Iw  u!>ed, 
olhurwim:  the  eflbct  1*  obacured  by  ibn  mon^  direct  stiniulatin^  m-tion  of  the 
currvnt.  If  now  the  xtriii  hi'  gently  bathed  with  n  wenk  nobilioii  of  alri>pine 
no  Much  inhibitory  clK^t  is  prudiiceii  hy  Ihe  intiTnipi<'d  rnm^nt ;  ihi'  Iteata 
go  on  ri-gardtetiH  uf  thi;  urtion  of  the  current.  Thi;  ititi-rp relation  of  thU 
expfrimi-jil  in  that  in  the  first  case  the  iiilernipled  citrrcnt  slimuUtrd  tho 
fiiK  termination  i>f  the  inbihittiry  iibres  in  the  muacnlar  strip,  and  tbnt  in 
tbe  second  caw-  the  alrcipino  pr<iiim«d  smne  ofiect  eith^rr  on  lh«e  line  librcw, 
or  on  their  connections  with  the  muncuUr  sulislanoc  or  on  tbe  actual  mns- 
cular  sub«t»nro  iUclf  by  virtue  of  which  they  ceased  to  act.  But  if  this  be 
so,  if  the  entnc  inhibitory  ctlcct«  tttw  produced  alike  by  etimulating  tbe  vaRua 
trunk,  and  Btimulatiug  the  vorv  cndnigi  of  the  nerva  in  tbe  muscles  of  tbe 
heart,  if  not  tbe  actual  muscular  tiesiie  itself,  then  there  is  no  need  to  6up- 
p(«e  the  existence  of  any  special  inhibitory  mecbaaism  placed  between  tbe 
tibrc8  in  the  VBg;us  branches  and  tbe  cardiac  muscular  tiasiie. 

Till.'  action  <  f  atro|)in«  on  the  heart  is.  so  ti>  apeak,  com)d«m«Dlcd  by  ttie 
action  of  muacarini;,  the  active  principle  of  many  imiNoiioua  mnnbroora*.  If 
a  small  iiuuntitv  of  mtiscarino  be  introiluced  into  the  circulation.  orapplM 
directly  U>  the  ficart,  tbe  beats  bwrjuie  *l'iw  and  fetible,  and  if  thedoM  be 
adequate  the  heart  is  brought  to  a  coniptet<r  iiliindiitill.  The  fflect  it  in  vonie 
respects  like  that  of  powerful  »timulatinn  of  the  vaguf,  but  tho  staiiil^till  is 
much  more  complete,  the  ellecl  is  much  more  prul'i'urid.  Now  if.  in  a  frog, 
tic  heart  be  brought  t"  n  flandiilill  hy  a  d<i»e  of  m»»cj»riiie,  tbe  application  of 
an  adetjuate  <|iianiily  of  nlropini-  will  bring  back  the  beal#  to  quite  their 
ni>rmal  strength.  The  one  drug  Is  a*  far  tui  tho  heart  is  concerned  (and, 
indeed,  in  many  other  respects)  the  antidote  of  the  other.  And,  as  in  tbe 
aae  of  atropine,  so  in  the  case  uf  muscarine,  there  is  evidence  that  the  drug 
acts  not  on  any  ganglionic  mechanisms  but  on  tbe  cardiac  tissue  itself. 

Tbe  conclusion  tbat  inhibition  is  the  result  of  changes  in  the  cardiac  llssne 
itself  may  »en'e  to  explain  why  in  inhibition  sometimet)  the  slowing  Mime- 
tiroes  the  weakening  b  tbe  more  prominent.  When  the  itibtbilorv  impulse*, 
by  rcawHi  of  particular  fibres  l>eii)g  atfected  or  otherwise,  are  brought  to 
bear  dti«fly  on  ihooe  [lart^  uf  the  heart,  such  as  the  ainun,  which  pu»»e«lng 
higher  rhythmic  ixitejiLiality  (tutt  ^  156)  deiermiue  the  Ae^uence  and  set  the 
rale  of  rhvthm,  it  iii  thti  raiv  which  i»  moat  markedly  airi'i^led.  Wlivn,  on 
tbe  other  bBn<l,  ihr^  inhihitory  tnipnlnes  fall  chiefly  on  llic  paria  {i><w<i>e>ing 
lower  rhythmic  potentiality,  Ine  nuwt  markc<l  i-Heet  is  a  diminution  in  tlie 
force  of  ibo  coniractiona. 

There  is  no  ade(|uatc  evidence  then  that  tho  citnliac  ganglia  act  n»  an 
inhibitory  iuecbani*m  in  tho  sense  that  they  prmhicG  imiKirtaiit  changes  in 
the  nature  of  the  impulse*  reaching  them  along  vagus  inhibitory  Iibres  before 
tJiose  impulses  puss  on  to  the  muscular  tivue.     We  may  add  tlial  there  is 


TUE    VASCtTLAIt    UBCBAXISV* 


ass 


I 


H     in; 


ftmilftrly  no  MlMjuate  BvidcDoi-  ihat  nDV  of  the  ganglin  act  ns  xii  "  nu^mt- 
iBg  "  uodutiUni.  We  have  piTvioiHly  iwn,  $$  lu'i,  1-06,  rca«oiie  for  thioking 
iIm  nogUa  nrv  Dot  ccniras  for  tbd  ori^oulinii  or  reeiilntion  of  the  gpoutaiiA- 
iiiM  liMli  Tbe  qucBtioii  ifaeo  ariipw,  what  are  Uicir  fimdionaT  To  this 
i|ilHliaa  ««  rnuiiot  at  present  fyn  a  wholly  luitisfacloiT  aoBwer. 

TTmi  inblliilory  RbrM  reiuuin,  bb  we  have  Mea,  niMlullated  libm  until  tbcy 
i««rl)  ihc  bdArl,  btil  it  would  apjK^r  that  tb^  lose  thdr  medulla,  somewhere, 
in  tbe  h«»ri  before  tJi«v  actually  reai-h  the  tnusculkr  tiwuc,  and  it  is  probable 
that  the  luM  takes  place  in  cuDiiecliou  with  aowe  uf  the  cardiac  gaDglia 
much  in  the  Mioe  way  thai  tbe  auj^eutiuK  librea  loae  their  medulla  in  Ibe 
ganglia  of  lh«  rrBipathetio  obaio  ;  but  we  do  not  know  whiil  is  tbe  pbyai- 
olopal  effect  or  Uw  purpoae  of  this  Ion  of  the  medulla,  aud  we  caunot 
MppoM  that  tilt*  i*  iJk  aole  or  eveu  chief  use  of  the  ^njilitu  Coinddenl 
with  ibr  luM  of  tbe  iiwduUii  nn  inrreaie  of  fibres  fretjueutlr  lake*  place, 
Bvorv  than  one  non-iiirdu  Hated  fibre  lea<niig  a  uervi?  cell  into  which  one 
aaadullaied  fibn  t«ter> ;  an<l  we  uajr  auppow  that  ihla  ntoile  of  branoltJag 
baa  ninoMa  am  fulfilled  by  tbe  mere  divuion  of  a  fibre.  Then  awaio  bearing 
in  awM  Ibt  nutritive  or  "  (mphio  "  function  of  the  apinal  ganglia  alluded  to 
in  i  100,  w«  may  luppn-e  that  the  cAnUac  ganglia  arc  ia  wme  way  coDcemad 
ID  tike  nutrition  of  the  cardiac  ii«rv«  &hr<«.  Ittit  our  knowlodge  is  not  yM 
Mttcieotly  ripe  to  allow  cxart  itatciDmta  to  be  mailv. 

Oiker  Injla«neei  Regulating  or  Modifying  the  Beat  of  tite  Heart. 

i  169.  Iniporlant  as  is  tite  regulation  of  tlie  heart  by  ilie  nervouji  iTiileni, 
it  ntMt  be  burae  in  miml  that  other  inAuencee  are  or  may  be  at  work.  The 
bwtnf  the  lieart  niav.  for  iii*iiiiu>-  h«  modified  by  inflm-iit'ot  bearing  directly 
t»  iIm  tiiilritioD  of  the  heart.  Thv  (iiwtiCM  of  the  heart,  like  all  other  tissues, 
D«e*l  an  adequate  sopplv  of  klixHl  of  a  proper  quality ;  if  the  blood  varyiu 
quality  or  i|uantily  tne  Val  of  the  heart  w  oorretp'mdiiigly  aflbcted.  The 
U(C)M<1  fruc's  heart,  as  we  have  aoon,  cmliuiHa  to  Mutt  fur  some  OOtuiderabla 
titoe,  lluiugh  apparently  emptv  of  bknd.  After  a  whilv,  boirever,  the  beata 
dimlntsh  and  dimppear ;  ami  their  diMppearanoo  is  greatlT  barieoed  by 
waafalng  out  the  heart  with  a  nornial  saline  lotutioo,  wnieh  wnen  allowed  to 
flow  through  the  cavities  of  the  heart  readilv  pemeaiea  the  tiiauei  on  account 
OiT  tlM  peculiar  construction  ($  ]ol)  of  tlie  ventricular  walU.  If  sue b  a 
"  wobed  nut "  nuicttcent  heart  be  fed  with  a  perfusion  canula,  in  Ihr  manner 
deecribtd  (§  155),  with  diluted  blood  (of  the  rabbit,  sheep,  etc.),  it  niay  be 
iMIiiiiil  to  Amctional  activity.  A  siniilar  hut  lew  complete  natotaiioD  may 
be  wftavMcd  if  sonim  )w  umhI  i&Htead  uf  bliHHl ;  and  a  heart  fed  r^[ularly 
with  froth  Mlppli<«  of  blood  or  eveu  of  ^rum  may  lie  kept  iMitlng  fur  a 
fWT  gnat  kngth  of  tin>c.  In  treating  of  tlie  akt^lelal  iiitiwliii  we  «aw  that 
fal  UMir  caJr  the  exhaustion  following  upon  withdrawal  »f  ibc  blood^otrcam 
aaicht  be  attrilniud  either  to  an  inade<iuate  xujiply  of  new  ntilritive  material 
and  oxygeo,  or  to  an  accuiniilalion  in  the  niuiu-iilar  Hutkttancc  of  the  proilucta 
of  muscular  tnetabolUm.  or  M  Ixilh  cnuMv  combined.  And  the  aiue  cod- 
ndentioiM  hold  good  for  the  ncn-ixiR  and  muwular  itruc4ura  of  tbe  beart, 
though  the  aubject  hsc  nt>t  yet  ttciu  ^udicicntly  well  worked  out  to  permit  any 
vary  definite  MaleaienLs  to  be  mn<le.  It  cwms  probable,  however,  that  an 
impoirtant  flutor  id  the  matter  is  the  accuiutilntion  in  tlte  muscular  fibree 
maa   bl  the  surroundiiii;  lymiih    of  carbonic  acid,  and   eepectally  of  the 

*T'Tf  which  give  rise  to  tlie  acid  reaction. 

When  the  frug'i  heart  ia  thus  "  fed  "  with  various  substancee  the  InterM* 
tng  fiwt  i«  brought  to  light  that  ■ome  Hibelonoes,  sueh  for  instoDoe  as  verj 


:.■■!■•.  such  I'lir  iiisiitiii.' 
■-..I--  '.■xjuiri^iiiii,  thiti  i^, 

Wiilllll    U|)[H'!II'    [Imi 

!■  .p  rlivrliriiii'  i'iiiitr;tr-- 

!■:   Mill-    lIllV   iiri'    Inll^i-r. 

■■■:  illv  ililiili's  lii'VMinl  [hi- 

'he  veiiiricli'.  w'nU  t\i>- 

Miiiil.      Fiirlli'-r,  iri  ili. 

•     -   .riiL'tlii'in'il   tliL'   rfl;i\;i' 

.'.■i]«irt.'nlly  thi'   vi'Uirirl-- 

;    "i.-It'il    wliiii    ;i    new   lii-;lt 

•>- -   I  '.i:    w.'   shitll   ,-[ii'!ik   lit'  ir) 

.  anil  [he  aiiLniiiit  i>t'  [iii- 

■  M.::v  lit'  llii'  vriilrii'li.',  varii-> 

-       -t7.  1-vilk-IIC.T    tluit     illlllliitiil  V 

"a.^k'  tltU  Ionic  cuiitriKiinn. 

'■!  with  siTiirn  iir  cvi-ri  uiih 

i-'i  h_v  -tiiiiiiliiti'iti,  lu'i'  ;i|ii  Ili 

-.       s   ^(ii  L'rlUl[l^.     This  inU'i-niii- 

_  uniiljk' ii>c'iiiTV  on  iiiitriti"ii 

st'<|Ui'nl  |ii'<Hliii'ti<>ti  uf  aliDiir- 

a"  fiiriliai'  inliTniiiii'in't's  >t^-n 

,iii>iu-  chi'inii'iil  siilij'iuiK'i--  in 

■|U'   lu-ni'['s   ln'at    l)v  aulid;^  "ii 

-.    'I'  liiilh.  anil   [liai    [iriihiililv  in 

^  ih*.-  rhythm,  nv  thi-  iiiiliviiinal 

-.  ■     ■-  ■['  ihc  hcarl  alsi>  alli'cl  its  Ixai  ; 

aiiiLiiiiit  III'  th<-  <li»ti'ii(i<i]L  111'  it.- 

.    -.  '. ,  liki'  ihiJM'  i)t'  nriliiiaiv  nuisih- 

■■,ii  Ivy  llif  ii'.-isiarice  whii'li  thcv 

-.iii'i'  lhi(i;;s  ln'in^'  tijual.  vndiraii 

.  ,  ■.  a.-  ill  ixiliiiary  niiisck'.  tilt'  limit 

.i-*i<i,  am!  an  Dvcrl'iill  ventricle  "ill 

.  [iriilialily  tiuiptics  it-dl'  ciiiii[ili'ii-lv 

■  ]nanlily  nt'  1>I I  in  the  vciiiiiclc 

'  ivs:  lilt'  i|naiiiity  ilirown  mit  w^iiilil 

«  'iihl   III'  ('ifc'icil  «iih  ;:rcatct'  I'nicv. 

■■;rii'lc   i-   .at   the  cinnnicnccnu-nl   .if 

;-■  aiiiii'iihii'  systiilc.  the  smrk  nC  the 

1  ■    '.•.■'■  is  ill  a  measure   triiveriieii   liy  thr 

•■■.  nui'lianical  ili^iis  anil   ilulirect  iitr- 

■■.  iieait's  Inal  til  111 i-]ircssnrc.     When 

-    lie  resi-liiljce  I'l  the  Velltlienlur  -vslnle 

:(!.  iiiiin.'  Kliiiiit  lliiws  I  ill  the    iiianiina- 

.  ■.■.■\.      I'.LTtli  these  eveiil,- iviiuhi   itiere.i-e 

;'i;    ex|ii'el    tlial    the    itierease  «iiuhl    lie 

i^  «ell  as  ill  the  I'lPi'ei-  «i'  the  iniliviilnal 

»e  i| I  li;ii|  ilii-,     <  In  the  ciiiitrarv 

-  ■■,  may  hi-  |iiii  alinnst  in  the  liirni  i>r  a 
■.'.Verse  laii'i  In  ihe  arlei'ial    [iresffUie  :  " 

'.'-  'IV  a  iliitiiiiiili'in.  aiiil  I'all  nl'  iires-iin- 
I'iiii*.  li'i»tvei'.  I'lilv  hiihl»   I'liiiil   if  ihe 


VASOUOTOR    ACTIONS. 


20S 


ra^  (ig  iuuu'U  If  (Imw  )>e  previnusly  dirliled,  then  io  irhaUvor  wny  th« 
MtMiH-praMU*  be  nUsed — whether  hv  injet^tiiitc  blood  or  clam(>iag  the  Horift, 
or  iatnamtg  the  iierlpheml  rtsiauuice.  ihrouieh  thut  uoii»ii  m'  tb*  vonomotor 
Dtrres  wbien  we  shall  harv  to  clfvcrilM.-  ilim;(lr — i>r  io  wbktercr  my  it  bo 
lawcKd,  wtaudi  clear  and  il4ft<l(yt  invcmr  rclniitjii  betir«en  blood-pretnare 
■sd  pube-rate  u  olwerrcd.  li  'n<  Infvrn^i.  iharvfove,  thHl  iiicrrnsol  blmxl- 
fiw ufe  cauM*  a  riowtni^  of  th<-  pi>l*r,  wlton  lh«^  vagi  an-  ititncl.  bi-ctiiiw:  [he 
fvnit'i- inhibitory  c^ntro  iti  thr  niviliillii  U  xtimulnltHJ  by  th'*  Wt^h  yrvMorr, 
cittwr  dimply  by  ihv  prrwun'  obliiiiiing  in  tb«  bloodvexmile  of  iIm-  mriliilln, 
or  ia  aoOM  indirect  nianiMr,  a»d  this  hrart  in  ooosmuence  to  a  «crKiin  extont 
toKibtted. 


CMA^IEB  IX  THE  CaLIBRK  OP  Tlie  StiNUTE  AkTERIBS. 

Action  I*. 


V.\BOMOTOK 


f  163.  W»  hav«  seen  r§  108^  that  all  arleriM  coolnin  plain  muacular 

ftbm,  for  tlie  nivot  nnrl  circularly  iliiijHinL-iI.  and  itiwt  abundant  in,  or  M»ne- 

timr*  alin(»l  rntirvly  oonlint*!  to,  ibe  iniddlu  otiut.     Wl^  biivc  furtbtirseen 

that  a*  ibr  nm-riea  beeonM  imnllvr  the  nimciiliir  rlumcjit.  tu>  n  rule.  Innioaiu 

nkorvand  mure  prominent  »  Gonipiini]  with  tlu-  olhvr  Htrmciit*,  niilil,  in  the 

Bunuir  artvrieii.  the  middio  cont  onsiota  almost  entirelr  of  a  series  of  plain 

Biw^br  fibres  nrAp|)C<t  nrniind  tht-  iiilcrnnl  coat.     Kervc  tihn-*,  of  whote 

aaiiin'  and  muree  we  abtill  prcatnilly  »|>cnk.  are  distribute]  Innn-'ly  to  the 

atVno>,and  a]>pi.iir  (o  end  cbicHy  in  line  ]>Il>xurgs  around  thci  nmsnilnr  fibre, 

Wl  dirir  exact  temiinatiunit  have  not  a*  yet  boon  clearly  niiuii;  out.     By 

ntcfcaaical,  el«clrical,  or  other  uimulntioii,  litis  muscular  coat  may,  in  tho 

livBS  artery,  W  iniule  to  contract.     l>iiriu^  thin  cnutraotiou,  which  has  the 

tlinr  chamcier  lx.-liiui{int;  to  tbe  contructioua  of  all  plain  luuade,  the  calibre 

U  thr  vomoI  is  iliraiuiiihHl.    The  veins  also,  a«  ue  have  wen.  poasen  min- 

(alv «temeDt>,  but  ihnr  vary  in  iimoiint  and  dlMribution  very  much  more 

iatbeveing  than  in  tbe  anfrir:>.     MimI  vdoit,  bovrercr,  are  oontraclile,  and 

■avrary  in  calibre  acconliiij;  la  the  cunitition  of  their  muscular  oleoieuts. 

Viki  are  also  mpplic*)  with  ticrv«s.     It  will  l>e  of  adviintage,  however,  bi 

omUar  aeparaloly  the  liltlc  n<!  l(iH>vr  cMicerning  the  chiuigca  in  the  veins, 

aail  \o  ODDnQe  ouraelvn  at  pm>ciit  to  the  change*  in  tbe  nrtcTie«. 

If  the  web  of  a  frne's  foot  be  watched  under  the  micmmnpe,  nnv  individual 
Mallanary  will  be  found  to  vary  coDnidcrnbly  in  calibre  from  time  to  time, 
Uv  ■oaMtinwa  narrowed  and  aometintc*  dilated ;  and  tbrso  changes  may 
Hhl  place  without  any  obvious  changes  either  id  th«  heart-ltcat  or  in  tbe 

rnl  circulation  ;  they  ar«  clearly  changes  of  the  arterr  itaolf.  Diiriog 
Darrowiuit.  which  i*  obviously  due  to  a  cootnwtJOD  of  tbe  muscular  coot 
<f  the  artery,  ihc  cHpillarics  fed  by  the  artery  and  the  veins  intonhicb  th«S 
Ind  become  leaa  filled  with  blood  and  paler.  During  the  widening,  which 
aSRqwnds  to  Ute  relaxnlMXi  of  the  muscular  ooat.  the  tame  parte  are  fuller 
rf  bUisd  and  redder,  (t  ia  obvious  that,  the  pfeesure  at  the  entrance  into 
■aripTai  artery  reDisiiiine  the  uiue.  moro  blood  will  enter  the  artery  when 
iwutioa  takes  place,  and  consequently  the  rcfttatanoe  oBered  by  the  artery 
iidiBfailalied,  ana  lees  when  contraction  uccura  and  tbe  resiaiauce  t»  conso- 
ipmly  incrensea) ;  the  blood  flows  in  the  direction  of  least  reaislnnce. 

TW extent  aixi  intensitr  of  tlie  narmniug  or  nidcniiig.  the  ooaatriction  or 
Alin  which  mar  thus  be  observed  in  ibe  frog's  wel>,  >'ary  very  Inr^ly. 
VuiMiooB  of  Alighl  extent,  either  more  or  less  r<^lar  and  rhythmic  or 
fal^plar.  occur  oven  wIm'u  the  animal  ix  njiparentiy  ■ubjected  lo  no  diaiurb- 
fag  liases,  and  may  be  ojwken  of  as  ^MuUneous ;  mrger  changei  may  follow 


26<t 


TlIK    VASClfLAB    MKCHASISU. 


events  occiirriii^  in  v&rioUB  pRits  of  the  bodr  ;  while  ns  the  mull  of  exp«ri- 
meolal  iiit«rfeivnci?  llie  srt«ri«B  may  become  either  eonslrictml,  in  eonie  ca««e 
almoflt  t'>  obUteration,  or  dilaled  until  tliej*  tic^uire  double  or  toon  tlmti 
double  tbeir  normal  dinmeler.  Thit^  conBtriclioii  or  dilation  mmr  be 
brouffbt  about  not  only  by  ireatnieni  applied  direotly  to  Ibe  veb,  but  also 
bv  cliaages  aDecting  tUe  nerve  of  the  leR  or  other  parte  of  the  body, 
lliua,  Mcliori  of  the  sciatic  nerve  is  (tenerally  followed  by  a  wideuin^  wbieh 
mi^  be  alight  or  which  may  be  very  marked,  and  which  is  sometimes  [>re- 
oeded  by  a  padding  eunatriction ;  while  stimulation  of  the  [leripheral  Mump 
of  the  4)ivtdeil  nerve  by  an  iut«rrupted  current  of  moderate  inteusit^'  gener- 
ally given  rise  to  conslriolion,  often  so  great  ns  almost  lu  obliterate  aotne  of 
the  miiiut«  arterlM. 

Obviouifly.  then,  (he  contractile  mii^rular  elements  of  the  minute  arteries 
of  the  wch  of  the  frog'ii  fool  are  capable  by  coutruction  or  relaxation  of 
caujting  dfcrrnw  nr  IncrMuwof  thi?  calibre  of  the  artcrie*;  and  this  cnudltion  of 
Con«tricti()n  ordilatton  may  br  brought  about  through  the  agency  of  the  uerve*. 
Inilci-fl,  not  only  in  the  frog,  but  hIm),  vud  utill  more  so.  In  warm-blootlvd 
iinimnK  have  we  cvi<U-ncv  Inat  in  the  CB»e  of  nearly  all,  if  not  all,  the  arU'riM 
of  the  bo<ly,  the  condition  of  the  muKCular  coat,  and  fo  the  cidibn-  r.f  the 
futery  is  governed  by  means  of  nerves;  these  nerve*  have  received  the  gvo- 
general  name  of  mMimolor  »(nw, 

S  164,  If  the  car  of  a  rabbit,  preferably  a  light  colored  one,  be  held  up 
before  the  light,  n  fairly  conepicuoiis  arierv  will  be  seen  ninning  up  tli« 
middle  linear  the  ear  accompanied  by  its  broader  and  nwre  obvious  veins. 
If  this  artery  be  earefiilly  watched  it  nill  be  found,  in  most  inataacM.  to  be 
undergoing  rhythmic  changes  uf  calibre,  constriction  alternating  with  ililatMO. 
At  one  moment  the  artery  ap|>enrB  ns  a  delicate,  hanlly  visible,  pale  streak, 
the  whole  ear  being  at  the  same  time  pallid.  Atler  a  while  the  arter}- slowlr 
widens  out,  becomes  broad  and  red,  the  whole  ear  blushing,  and  many  smab 
vessels  previously  invisible  coming  into  view.  Again  the  artery  narrows  and 
the  blush  fades  away ;  and  this  may  be  refteated  at  Humeuhnl  irregular  inter- 
vals of  a  minute,  more  or  leM.  The  extent  and  regularity  of  the  rhythm  are 
usually  markedly  increased  if  the  rabbit  l>e  held  np  by  the  ears  for  a  short 
time  provioui  to  the  olwervatiun.  Hiiutlarly  rhythmic  variations  In  the 
calibre  of  the  arti-ri*^  have  been  oliserved  In  iwveral  placM,  t.y.,ln  the 
vcanls  of  tile  mesentery  anil  cloen'bere ;  [irolmbly  they  are  widely  spreml. 

!y>motim<»  no  snch  varintioni'  are  seen,  the  nrUrrv  remain^*  constant  in  n 
condition  intermediate  between  the  more  extreme  wiifening  and  extn-me  nar- 
rowing just  described.  In  fact,  we  may  Rpeiik  cf  an  artery  as  being  at  nnv 
given  time  in  one  of  throe  phaioa.  It  may  be  very  constricted,  in  wbicli 
case  its  muscular  fibre«  are  very  much  contractoi) ;  or  it  may  be  dilaud,  id 
which  case  its  muscular  fibres  are  ralaxcd  ;  or  it  may  bo  moderately  con- 
stricted, the  maseular  fibres  being  cx>nlraeted  to  a  certain  extent,  and  remain- 
ing in  such  a  condition  that  they  may,  on  the  one  hand,  pass  into  stnuiMr 
oanlrsclion,  leading  to  marked  constriction,  or,  on  the  other  hand,  into  dis- 
tinct relaxation,  lending  to  dilation.  We  have  reason  to  think,  as  we  shall 
see,  that  many  arteries  of  tlie  body  are  kept  habitually,  or  at  least  for  long 
periods  together,  iu  this  intermediate  conoilion,  nbicli  is  lire<]U«nt)y  spoken 
of  as  tome  conlraetion,  or  (okus,  or  arleriat  lont. 

§  165.  If,  now,  in  a  vigorous  rabbit,  in  which  the  heart  is  bouing  with 
■dequate  strength  and  the  whole  circulation  is  in  a  satisfactory  condition, 
the  cervical  sympithetic  nerve  be  divided  un  one  side  of  the  neck,  remark- 
nblc  changes  mar  be  observed  in  the  bluudvessels  of  the  ear  of  the  same  «de. 
The  arteriw  and  veins  iriden.  they  together  with  the  small  vein*  and  the 
capillaries  become  full  of  blooil,  mmiy  veuels  previously  InvUble  coiuc  into 


TASOMOTOn    ACTIONS. 


267 


"View,  Um  <rhole  ear  blufthM,  mikI  if  ihi-  rhythmic  chnngc»  described  above 
««t«  pcvriondj  goio|;  on,  th>«o  dow  oeaae;  unl,  in  cmiicqu^ooe  of  the  «sira 
mppl^  of  wmnn  bloc^,  tlw  whole  eur  beooinm  <li>tinctly  irnrm«r.  Now  Oieee 
rliu>g«a  uhe  plsc«,  or  may  take  place,  witlioiit  nnr  ■Ittrmtion  in  th<^  h«art- 
Ihsi  or  ill  tbe  |;e»cral  circulation.  Obviougly  the  arlcnr*  nf  llic  viir  have,  iu 
iiiMmUllliliiii  of  tb«  wctioo  of  the  oerve.  lost  th«  tonic  c»ntrnninn  whioh  pre- 
riaadj  exuced  ;  iheir  muioular  cohIji.  previously  fomewbnt.  cotitraclitl.  httve 
bMMlW  quite  relftXei),  anil  whatever  rhythmic  coDtmctions  wi-rc  pre- 
Tinodj  going  on  Iiave  ceaseil.  The  miire  rnnrked  the  previous  tonic  conlrac- 
ttnn.  UM  ibe  more  vigorous  tbe  beArt-benta,  hi  that  there  is  mn  ii<lii]uaie 
Mpplr  of  blooil  to  Git  tbe  widened  clianD«ls,  tbe  more  striking  the  rMiilU. 
StHnettiDCi,  ■•  wh«n  t)i«  heart  is  feeble,  or  the  preexist iufc  tooic  conUtaction  b 
•Iwlii.  tb«  nection  of  th«  nerve  produce*  no  xm  obvious  chanee. 

If,  bour,  the  upper  Mgnient  of  tbe  divided  cervical  sympaUielic  aervo — 

tbM  k^  tbt  portion  vt  the  nerrc  pniinng  upward  to  ibe  bead  and  csr — be  laid 

apaa  dw  eleeirodM  of  an  induction  machini.'  amlaifcnile  tmerrupled  current 

b«  Hitt  through  tbe  aervc,  new  chanms  lake  phice  in  the  hlixidvewela  of  th« 

tmt,    A  ■hiiri  liniv  after  tbe  application  of  the  current,  for  iii  this  efTect  there 

k  a  html  period  of  very  appreciable  duration,  tbo  car  grows  [>aler  and 

eeolar,  nany  nnall  vcskIs  previoualy  ixmipicuous  become  again  inx-isible, 

tba  maJB  artery  shrinks  to  the  (hintmt  i)ir>tid.  iind  the  main  retna  become 

eami|MiDdinglr  sniKll.     When  rhe  current  is  »hui  off  from  tbe  nerve,  theae 

«BhcU  dill  last  some  time,  but  eventually  pan  oR';  the  ear  rcddvnN,  bluahes 

ooet  mort.  and  indeed  may  become  even  reilder  and  bolter,  writh  the  veoMla 

Bwn  Blled  with  blood  than  before.     Obviously  the  current  hfu  generated  in 

tba  emical  sympatbeiic  nerve  impulses  which,  passing  upward  Ui  the  enr 

aad  Boding  ifaeir  way  to  tlie  muficutar  coals  of  the  arteries  of  the  luir.  have 

tbnea  tbe  niit*clM  of  thow^  omIk  into  forcible  conlmctioDx,  and  have  thus 

hna^t  about  a  for<rible  narrowing  of  the  calibre  of  the  arteries — a  forcible 

tnmuietioa.     Through  ^h^^  narrovri.-<l  vi>iu>lrivtctl  arteriat  lesN  blood  tinds  its 

wvj,  aad  bcnor  the  [wlcntw  and  colitnm  iif  the  ear.     If  the  impulsee  thus 

C'aied  be  vi-ry  strong,  the  constriction  of  tbe  arteriw  may  be  so  great 
Uw  iniallMt  iguantiiy  oiily  of  blond  can  make  ila  way  through  them,  and 
lieiarmay  become  almost  btoodlen.  If  tbe  impulM*  be  weak,  the  coustric- 
li<«  bducM  may  be  slight  only  ;  and,  indeed,  by  carclnl  mnnipulatiou  the 
■MTfl  may  be  induced  to  send  up  to  the  ear  impultiv  only  juici  xulBciently 
Mn^  to  restore  the  moderate  tonic  conetrictioD  which  existol  before  ibe 
aim  wa?  divided. 

We  infer  from  lh«ee  exjieriments  that  among  the  various  nerve  fibres 
■akiDtf  up  ibe  cervical  sympAtbetic,  there  are  certain  fibres  which  jMwiing 
apwafil  tu  the  head  become  connected  with  the  arteries  of  the  mr,  an<l  that 
line  tilirva  are  of  ruch  u  kind  thiit  impuli^es  };eneraled  in  them  and  jnmiug 
gfwsnl  U-  tbe  ear,  lend  to  marked  cuuiraciion  of  the  mu*cular  fibre*  of  the 
ancrie*.  and  tliu.i  produce  eoiMrictiun.  These  fibres  are  vaaomotor  fthn-a 
^  iw  the  bloodvewels  of  the  ear.  Fn>u  the  loc«  of  tone,  ho  frequently  follow- 
H  Bf  section  of  tlw  cervical  iiympatlieiic,  we  may  further  infer  that,  normally 
H  wiag  life,  imptibet  of  n  giiitle  kind  arc  eoiitinuall^  (lassin)-  along  thceo 
H  Ara*.  upward  through  thr  r4;r\-ical  aymjiathetic,  which  impulses,  reaching 
P  tk  arteries  of  the  ear,  maintain  tbe  normal  tone  of  thoee  arteries.  But,  aa 
••■id,  iheestMenceof  this  tone  is  not*o  oointant,  and  tbfse  tonic  impiitses 
M  not  fo  conepicuoits  as  tbe  artificial  constrictor  iinpubea  generated  bj 
itimlalioo  of  the  nerve. 

1166.  Tbe  above  nviilts  are  obuined  whatever  be  the  region  of  tbo 
Mrrienl  aynipatUetic  which  we  divide  or  itimulate  from  Uk>  upjier  cervical 


268 


TIIK    VASCULAR    MUCIiAKISM, 


^n);[1ii>ii  In  Ibe  lower.  We  m«v.  lh«^rcfor*,  tlc«crib«  ihwp  viwomotnr  im- 
pulse!! ua  [iaBsii)g  upward  Irurn  llic  loner  ccrvicnl  ^ii^jlion  nlone  the  cervical 
Myiii|)iilhei!i.',  to  the  upjiirr  mrvictil  ganglion,  rrom  irhich  iliev  iwue  br 
liniiK-hcA  which  uUiiimiely  tiiid  ihelr  nav  to  (he  car.  Itut  llitM«  impulBes  do 
not  mart  fnnti  the  Imkt  cenricol  gnnglion ;  on  ihe  coDlran\  by  repoitting 
ihe  i'xnrriiii?i)t«  »f  ilivEjilon  nnd  HtiiuiiliilioH  id  a  aeries  iif  iiuiiualh,  nv  mar 
tnict  itic  nnlh  ol'  ihrse  imiiulHcs  fntm  the  lower  t-ervical  ^iigtlon  (Kig;-  97) 
ihroiigti  iho  annidu^  of  Vietiswos  lu  ihe  gaii^liuu  lullatuni  ur  firM  thoracic 


tiu«HA>  lU.usraAtixa  710  Patih  trr  Vjv«<«<an«XToa  Kiiiaai 
AixiKit  TirE  ctHrtcu  STHfittHma  a>i>  (rin  w)  Tua  ApommimU' 

9ria*aiMC 

Ami.,  >il<T)'  ol«ar.  'i.L'.» .  nipetlor  orrrlotl  puulWu;  XIABpl.. 
ii[>)n'  nuuurbni]  |i*rt  of  al-lomlDii)  a|iluioIiulc  uarm:  V.M.C  «■>»- 
nuilor  ivuiivtii  iuviIiiIIh.  'fliv  oilw  raltmicn  *n  (h*  mmt  ta  in 
PIr,  W.)lin.  TliB  t«''»  urihe  oiDnriclor  niitt*  an  ibowa  hj  tk* 
armwi.  Ttu  itoiiail  lliiu  Iti  iliD  tjilnal  cofd.  8f^C  ii  to  tndkaM  !&• 
roiHBe  (if  tiiiuLHctDf  lin]iul*a  dona  Ui*  O0«il  AolD  Uie  < 
(<uiilr«iii  Uic  iHMlulla. 


ganclion.  aiid  theuce  either  along  ihe  ramus  commuuictuis  (visceral  branch) 
to  ilifl  unt4-rti>r  rniii  uf  tbc  second  darutl  nerve,  and  thus  u>  Ihe  HpinnI  cord, 
or  lower  down  along  the  thorncic  Hyinpaikeilu  cliaiii,  and  lliciice  by  iXher 
rami  com nniiii I'll iit*ii  lo  sonic  other  of  the  upper  doraal  nerve*,  and  ibu* 
to  lh«  spinal  cnnl.  The  pulh  talien  by  the*e  vatiomolor  iinpulw^  for  ll>c 
Mr  b  in  fact  very  Mniilar  to  that  uf  tht:  ntignK'nior  tibren  for  the  hrart  icf. 
FiR.  9(i)  from  the  spiual  cord  up  lo  iho  niniidiiH  of  Viciumnit  and  i«  the 
lower  oerviral  ganglion  ;  hut  there  th'-y  part  company.  \Vv  can  lhn:<  tracei 
tlwoe  iiDpulaes  along  the  cerrica]  svmjuithetic  to  the  anterior  root*  of  cvrtaia 
doiMl  nerves,  and  through  lh«ae  to  a  particular  part  of  tbo  BPUial  conl. 
vhfK  we  will  for  lh«  present  leave  ihem.  Wc  may  accordingly  speak  of 
vaaoiDotor  fibres  for  tlu-  car  as  pawing  from  tbo  doraal  ipinal  cord  to  the 
ear  along  the  track  just  marked  out ;  stimulation  of  iticw  fibm  at  ihair 
origin  in  the  spinal  cord  or  at  any  part  of  their  course  (along  tlie  anterior 
raota  of  the  second,  third,  or  other  upper  iloreal  nerves,  viseemi  brancbee 
of  lho*e  nervftv  ganglion  stcllatuni  or  upjier  part  of  thoracic  syiupatbetie 
cbain,  annulus  of  Vieuasena,  etc.)  leads  to  constriction  in  the  b'looavesseU 


VASOMOTOH    ACTIOKS. 


309 


of  Um  cat  cl'  thai  nda;  tand  ■ection  of  ihne  fibm  at  any  part  of  tli«  mme 
wnm  uod*  to  nboluh  nay  prcviotitly  txbtiii^  tonic  ooiwtrictioti  of  the 
UoednsMb  of  tbo  *ar.  though  tt)i«  rllKt  is  not  so  coosbint  or  iiariliiog  as 
tlwt  iif  rtliDakUon. 

6  167.  W«  nUMt  now  luni  to  another  caae.  In  d«alin);  n-ilti  fliK«etion  ire 
•ImU  have  to  itudy  tli«  Mibmnxiltury  salivary  gLaiid.  We  may  for  tLe 
pCVMt  ainply  aay  that  this  is  a  (•laudular  inafs  well  supplied  with  blood- 
riaib,aad  powcaJng  tt  double  nervous  supply.  On  the  one  hand  it  reeeiree 
flbm  ftom  the  eervical  ayinpnlhotiu.  l-'i;;.  Ot5  v.ei/m.  (in  lh«  dog,  in  nhidi 
tlkc  Hfecta  which  we  are  abotit  to  deacribe  are  bat  wen,  the  vafcus  and  cervical 


rni.  w. 


*«■>>■■  iTur  Rtnaonittcui  nr  tiia  BrnmixtuAav  Glixd  or  m*  Doa,  vim  tn  KmvM  *ki> 

BlJMITVMUA. 

TWiUmc^Idx  ku  tiNd  mult  (HI  ■■Knliiul  Ijlnf  on  it*  tack,  tint  iIdcciiII  IhB  puti  iIidwd  tn  Qtc 
afB*«adai  Mon  Ihnnuir  oacfulntof  Tt«r,  ibeBKiuvlaet  iioi  kIv*  Uie  ciarl  anuonlio]  rvK- 
*««r  tt>  n*«Hl  MnwMN*. 

»t^Hi«— lm»lltMy«l»jna.  lnu>tbBdiici[—.  Jml  which  aunolA  bu  bran  Unl  llwntb- 
MaHl  (iHid  and  duet  uo  nutibuoii.  aJ..!!/.  Tlic  Uiik'i'I  tiniiicli  i-rtlwMli  oorvo.  tl»«(*n  sj. 
•  fM^lattalcafw^  <*,f..rAf  .rb  r  Thocliooli  trmr>»l.  I'bi  (•!(  (A. I",  li  rxxmllnc  Roni Ik* 
tiM  Mn«,  •>  (ft.  r  tt  btcona  Rin>)IiiL>d  wlih  Ibc  tinituil  i>.r.,  uiil  ancnfard  illnnclnc  j«nii  M 
At  l>  Iha  lUiht  alonf  tlniliKt:  ih*  «nilliii»riuii  of  Ibv  nirvptn  nuDistiy  wilh  Ihr  llninuil.  n.l..t> 
■»  (J  Tim  wlw  I  in> IT  »"■>""■*'" I*  "'  — J-™' «— ^-  a.  cor  "na  ouiMUl  krurj-.  Iirn 
■bvof  wMi4i,  ■.•!•■  «.u«l  r,  ■u.p.,  IWB  (o  (be  ■nlorkii  luid  powwlor  t«n>  of  lb*  yUnd, 
<  ■■  tts  Milwtot  and  ixMarlur  Tdn*  frum  Uw«land,  Atlllus  lata  r./.ttui  Jugular  t>Iii.  r.i9iK.Tti« 
I  i«(iB  and  (n>iF*UMU<i  iniok*.  g,  frf,  i.  Tbe  uppii  nrrlotl  aangUon.  l*o  bniiialic*  of 
■iiK  ■  ptdn  (oj-t  onr  Ihs  llulal  utcrj.  an  dlilrlbutnl  (a.ivKni.i  alont  tbo  Iwn 
I  Id  Ih*  aoMsm  and  (oU^or  ronlcn»  of  Itivsland. 
Ha  WW  «a  todinaw  i>a  dlwwllwi  ukvit  by  iLeaEnKiiii  Myulta  dsrlni  mztx  iilaiulatkni  pIU* 
nar  nwuid  (a  IJic  loaln  br  Um  Ungual  aiid  dcaomd  b;  Ike  cborda  ljnii«iU. 


)*tBfaihrlic  aro  encJoewd  in  a  c<>niin<iu  sheath  »o  as  to  form  what  appean  to 
Maiinclv  trunk),  which  rea«h  the  gland  in  eoni|>aiiy  with  the  arteries  nip- 
plmgUivglMid  (N.nwm.  fm.).  On  die  oth«r  hand,  it  rcceivoi  fibnv  (W>ri  a 
^alTBervv  callnl  ine  chorda  tympani  (cA.fJ,  which,  springing  from  the 
VTWih  cranial  ( iWiid)  nerre,  crown'  Uh-  tympanum  of  the  tuir  (henoo  the 
Mat)  aitd.  joining  tbi^  lingual  branch  of  the  fiAh  norvr.  rum  for  «ome  ilin- 
Uan  m  compaDy  with  Ihnl  n" rvL-,  and  then  ends  partly  on  thi-  tougtie,  and 


270 


TUe   VASCULAR   mkcuakish. 


partly  in  k  small  nerve  which,  leaving  tlia  linriMl  nwre  Itefore  rcttchio);  tht 
longucruM  alnng  tlie  duct  of  the  tubnudTwry  gUod,  mkI  is  lost  in  ihe 
ButMtaoce  of  the  glmM) ;  a  small  branch  is  also  given  09"  to  the  Bublioi;iial 
jllund. 

NoTc  wiieii  ihe  clitirdu  tympnai  ia  siniplv  divided  no  verv  rvin&rkable 
cUuiii;eti  ulce  place  iu  the  bloodveesets  of  me  gliind,  but  if  t}ic  peri|ih«ral 
eet;i>ic<il  of  the  divided  iiervi?,  llinl  still  in  counection  with  tli«  ulaud,  )» 
atiiuuliit«*l  very  luarkt-d  tchuUs  fullow.  The  suiall  arteries  <if  the  gluoA 
become  Tcry  much  dilntei)  and  the  wbole'glond  becwoea  Btisbed.  (A»ki> 
tball  ne  Inttir  ou  tli*>  gland  ai  the  jiame  time  secretea  aaliva  conioudy,  but 
thia  doea  not  cuiicerii  ua  just  now.)  ChiiDijee  in  the  calibre  of  the  bloUiro- 
wIh  are  of  cniirac  nut  *<>  reinlily  mcu  in  a  compact  glnnd  a«  in  n  iliiii  pjctentled 
but  if  II  fim-  tiilit^  \>c  [ilticeil  in  one  uf  tliv  small  veini>  by  which  the  blood 


rnr 


rettirna  from  the  gland,  thv  eBeotd  ou  iho  bl(ir)ilvi>wi*lH  of  iftimulutin};  tbc 
cborda  tym|iiiini  Ikciihic  very  cbvicu?*.  Before  (ttmulation  the  Wood  irickla 
wit  in  II  thin  nlow  nin-ani  of  a  dark  rcnoua  color;  during  atiniulation  ibe 
bluod  ni»h(9  out  in  ii  rupid  full  streum,  oilcii  with  a  distinct  pulsation  and 
frc<|Ucnlty  of  n  color  which  is  still  scnrlit  and  arterial  in  spile  of  the  blood 
having  IravcnK-d  the  capilluries  of  the  glnnii ;  the  blood  rushes  so  rapidly 
through  the  widened  bloo<lveiwtels  that  it  has  not  time  to  undergo  cnrnpfetely 
that  change  from  arteriiil  to  venous  which  normally  occurs  while  the  blood 
it  travervitig  the  cKpillaries  of  the  ginnd.  This  state  of  thing*  may  continue 
for  SOBM  time  alter  ihe  sriuiulation  haa  ceawd,  but  before  long  the  6«w  from 
the  vans  slaokeRs,  the  iHuiiiK  blood  liecoaiea  darker  and  veooue,  and 
eventually  the  circulation  beftmea  uonuul. 

Obviously  the  cborda  tynipani  contains  Rbrea  which  vre  war  ii|>eak  of  aa 
"  vasomotor,"  since  stimulation  »f  them  produces  a  change  iu,  and  bring*  about 
■  movenieni  In  the  hliiuiive(«ela ;  but  the  change  produced  ia  of  a  cbaractvr 
the  vm*  opjMMtili;  to  that  produced  in  the  Moodvewivlit  of  the  mr  by  simula- 
tion of  the  cervical  sympiithelic.  There  stimulation  of  the  nerve  cmtued 
contmctiou  of  the  niu«cutar  fibres,  constrict  ton  of  the  small  arteries:  here 
stimiilalion  of  the  nerve  cniist^  a  widening  of  the  arterien,  which  nidening 
is  undoubtedly  due  to  relaxation  of  the  musailar  tibra*.  Hence  we  most 
distinguish  b^wcen  two  kinds  of  vawniotor  fibre,  fibrea  the  rtimulation  of 
which  produces  constriction,  KOAo-eonttriclor  (ibrus.  and  tibree  the  atimulalion 
of  which  causes  the  arteries  to  dilate,  va»0'dUali>r  fibres,  the  one  kind  being 
the  antagonist  of  the  other. 

The  reader  can  hardly  fail  to  be  struck  with  the  analogy  between  theae 
liro  binds  of  vasomotor  ^hres  on  the  one  hand,  and  the  inhibitory  and 
augOMntor  fibrea  of  the  heart  on  the  other  hand.  The  augmentor  cardiac 
Hmta  increase  the  rhythm  and  the  forc«  of  the  heart  beats  \  the  vaso-oon- 
Kttiotor  fibrea  increase  the  coDtractionsof  the  muscular  fibres  of  the  arteries; 
the  one  works  upon  a  rhythmically  active  tissue,  the  other  upon  a  tiaiue  whoM 
work  is  more  or  lea*  continuous,  but  the  etTeot  is  iu  each  case  similar — an 
incieaM  of  the  work.  The  uihibitnrr  cardiac  tibr««  slacken  or  Ntop  th« 
rhythm  of  the  heart  and  dEminish  the  tieat* :  the  vaso-dilator  fibres  diminish 
the  previously  existing  coiitructinn  of  the  muHciilur  fibres  of  the  artcrin  so 
that  these  expand  under  the  prewua-  of  the  blood. 

We  must  uot  attempt  here  to  di*cuwi  what  is  the  exact  nature  of  ihe  pro- 
ctw  by  which  the  nenoux  impulses  poising  down  the  fibres  thus  stop  coo- 
traction  and  induce  relaxation,  but  wo  may  wy  that  in  ull  prdhahility  ibe 
proceee,  whatever  be  its  nature,  is  one  which  tnkc«  pliue  in  the  muscular 
fibre  itself  on  the  arrival  of  the  nervous  impulse,  and  that  (hen^  is  no  need  to 
pn-wppoM  the  existence  of  any  special  terminal  inhibitory  or  dilating 
nervous  mecbanism.     We  have  repeatedly  insisted  that  the  relaxation  of  a 


\ 


VA30MOTOB    ACTIONS. 


271 


I 
} 

r 


fibrv  i>  a*  tuuch  a  complex  vital  procns,  i»  u  Irulir  th«  reeuit  of 
DoUmu  of  iIm  muHGular  AubstiiDce,  as  llie  ooiitractioii  iMelf ;  and 
tbwv  ii  A  oricti  tio  rawoa  wlir  a  uervuu*  iiiipuNo  >hoiil<l  not  Kuverti  tlio 
liinwr  u  It  doc*  the  lulter.  AVl-  tuay,  jMrhiijw,  ^i  I'lirtlier  aiiS  M\y  ilint 
rcUxatNOi  need  not  b«  cuuHd<er«()  lu  tbe  iti«rc  iiutloiiij^  of  a  citutrm-lina  ; 
tb»t  %h»  actioo  of  dilator  fibru  in  ool  nMHwnrily  Itmiie'l  Ui  ihc  rrniuval  of 
B  prvvioudj  cxipttuj^  cowiricliuii.  We  miiy  iiiuigiiic  n  tiiuimilur  tibri'  lu 
—bjacl  toUirnctiuool'tvo  <>[i|Hitiiiig  l<im» — ttiv  uite  vioiigntiiie.  rvinxirig.  or 
dOatiHI^  :  th«  otlicr  vbortCDing,  ■.■nuimcling.  or  ouiulrictiiig.  When  nviilhtr 
i»  in  acUoo,  or  «bni  thv  too  ati;  («ii]i{i(ill»it,  tlio  fibn  it  at  rCHt,  Deilhaf 
nlaxiDg  RorcoDtnu-ti»g;  nlx'u  iiiieacUaluiiv, orwh«a  one  acts  more  pontes 
fullr  tluui  tliv  othvr,  itirii  rrUxntioa,  elougnlkiii,  dilatiou.  or  otiivrwiae  coii- 
trw^tun,  sboru-uiii);.  LviU'tric-tioD,  u  tli«  mult  ;  wu  liuvo  )>rob»bly  a*  muctl 
riKht  tu  (uptww  rt'ltixaltou  tt>  bo  a  iiitvasiry  nntvi'eilcot  of  oonLriiction  aa  tO 
■uppMc  couuacliou  to  be  n  uvccaaity  uitocnJvnt  of  ivIaxatioD. 

( 168.  Uut  we  rauBt  ralurn  to  th«  vaMunotor  twrrm.  The  oerviod  sjiDpa- 
tbAir  (XiDtaitM  vaaoconelm-tor  fibres  for  the  ear,  and  vk  may  now  add  for 
•tbtT  rafioBtr  alao  of  the  head  aod  t'licc.  TIiuh  the  brundiea  of  the  oervtcal 
i|MtliMic.  ijoinji  tu  the  «ul>mnxillary  inland  of  which  we  juat  epoke  (Fiff- 
n.  *jtit.  am.),  euntsin  vaeo-eonslriclor  libnn  for  the  Tewejs  of  Uw  gland  ; 
•llinuUiiun  of  tbeae  fibres  producw  on  the  vessels  of  the  jfland  on  elftcC 
exsctlT  tbir  opporile  of  that  prudticed  by  BiimulatJDO  of  the  ehorda  tjrnipani. 
But  l(>  iki«  paulicnlar  point  ire  aball  liave  to  return  H'h«n  we  deal  with  the 
ylaad  lu  connection  with  dJ);ettiiou.  A  more  importinii  fact  for  our  present 
parpOM  b  that  the  ecr\'ical  evnipulheiic  appenni  U>  ooniaiu  only  vii»o-4.-i>n- 
auiolor  fibrea;  if  we  put  oude  m  exceplioiiul  and  doubtful  the  rvxult  uf 
certain  oheerrem  who  obialtied  vaau  dilator  cdccLn  in  lliv  nimilh  and  fnvc, 
v«  any  aay  that  in  no  re){iou  lu  nbich  tht?  libm  of  the  crrviciil  aympathctic 
•na  distributed  can  any  vavo-dilator  avtion  l>c  observed  a»  the  result  of 
•tlinalation  of  the  nerve  at  any  [lart  of  il«  course.  In  the  chorda  tynipani, 
Ml  the  other  luind,  the  vuwniotor  tibn^  are  exchisivelr  vnsudilalor  fibres, 
and  ihts  is  true  both  of  the  part  of  the  nerve  eudin;*  in  the  Bubmaxillary 
■nd  *ubtiD|[ual  gland*  and  the  mtt  of  tlin  ending  of  the  nerve  in  the  tongue. 
i?(iliiulatioD  of  the  cliorda  lympani  (a»  far  as  the  vosoiuolor  lundiona  of 
tba  narre  are  iionccrned,  lor  it  hoa,  as  we  flhall  »ee,  other  fuDciions)  at  any 
patftof  lt>  courae,  frum  ii»  Icnviiig  the  facial  nen-e  tu  its  endings  In  the 
nogn«  or  gland,  producee  only  vaso-dilator  etleet».  never  vaso-constrictor 


Wkh  many  other  oervee  of  the  body  tite  case  ia  dilTerent.  In  the  frog 
dhrliiMi  of  the  sciaiU!  aarn  teada  to  a  widening  of  the  arteriui  of  the  web 
«f  tbt  Cmx  of  the  aane  tide,  and  stiniulaiion  of  tlie  peripheral  end  of  the 
MTT*  fiiscs  a  constriction  of  the  vessels,  which,  if  iht;  Miinulatiou  Iw  strong, 
naty  ba  ao  great  that  the  web  appears  for  the  time  licing  lo  Ih-  deruid  of 
blood.  Abo  ill  a  maromal  diviHiou  of  tfai^  Kialic  iutvc  causes  a  Himtlar 
widnting  of  the  small  arteries  of  the  akiu  of  the  leg.  Wheni  the  condilioii 
uf  Um  escalation  can  be  readily  examined,  on,  for  iiutanee,  in  the  linirloB 
Ulboftbe  too. especially  when  these  aro  not  pigmi'ntml,  thevesscJs  are  seen 
to  be  •litalc«l  and  iitjecteil,  ami  a  thennoneter  placed  between  the  loot  shows 
a  rise  of  teiii{ierature  aiuouuting,  it  may  Iw,  to  •vvemi  degrees.  If.  morv- 
«>r«r.  the  peri|tli«nl  end  of  the  divided  nerve  be  stimulated,  the  vcwels  of 
the  skin  beootnv  cvnttrictvd,  the  «kin  growi  pale,  and  the  Iciuperature  of  the 
flat  fclU-  And  very  nmilar  mulls  are  obtainctl  in  the  fore-limb  by  diviuon 
tad  •ufaMqacnt  stimulation  of  tlw  nerves  of  the  brachial  ]>lexus. 


272 


THE    VAaClTLAK    UKCIIAM8M. 


The  iiuunliiy  of  blood  prtwot  In  ibp  bloodvcaiela  of  the  mamnal,  thongh  K 
niaj  AODiclira^H  be  oburved  directly,  tutu  rm)Uontly  to  be  d^lcrinined  indinctly. 
The  (ompcrHtiirc  nt'  pasnivc  i>triicturn>  lubifCt  Id  cooling  inllucnc**,  ■u<^ll  ut  the 
nkin,  i»  tnrKply  ilependcnl  oii  ihr  Miipplv  iil'  bUtod  ;  the  inotu  nbunJanl  the  Miiipl* 
the  wftnner  i^i?  pnrt.  Ileiice.  iu  tl]«ae  purts  variutiuiis  in  the  qiianiiiy  <if  blixKl 
may  be  inferred  TrotTi  Tmifttions  of  temperature:  biil  in  dealing  wilh  more  ik-iIvi^ 
Hi (ucturos  there  nre  i>bviou»lf  •ouroos  of  error  in  the  imuibility  of  thr  treatment 
adopted,  ouch  as  the  ■UmulBtion  of  a  nerre,  KiviiiK  riito  t'i  an  incrtuuc  nf  tcrnpert- 
lur«  due  tu  increiuwd  metaboli«m.  indepwident  i>f  variHilooii  iu  blutKl-supplv. 

The  <|uaD(iiy  ut  blood  mav  also  be  determined  by  Uie  pktIiyimoffTttph.  (o  Uila 
InatTuinent  a  pari  of  the  body.  «u«h  m  the  arm,  is  introduced  iuto  a  cloaed  cham- 
ber eilwi  with  Hniil,  rx.  gr..  a  Inrge  glas*  tube,  ihi-  (ipeninK  by  which  the  arm  ia 
inlroducL-d  hthia  securra  with  u  ultiul  cuniitcbnuc  uieinhrnne.  An  inprtAao  or 
d«crcac«  of  blood  aeni  Into  the  arm  will  lead  to  au  iucrearie  or  dcicrcBM  of  the 
volume  of  the  arm,  and  this  will  make  ilacif  fett  by  an  increase  or  dimlnutiMi  of 
preMUK  in  the  Huiil  of  the  ciosed  chnrobct,  whioh  may  be  repimwed  and  meaa- 
urrd  In  the  unual  wiiy.  Wo  •hall  have  to  iipcHk  again  of  n  luodilicntionof  thla 
iiMlrumeat  «'b«u  w«  are  dealing  with  tile  ktdiiey. 

^  far  the  reeults  are  quite  like  llioae  obtained  br  division  and  atitnulation 
of  the  cervical  sympalhetie,  and  we  might  infer  lliut  t.bu  M.-iniii-  ner%-e  aiid 
hrachini  plexui  coDtain  vaeK^eonsirictiir  fibre*  for  the  vectebi  of  the  sktu  of 
th<^  himl-Iioib  and  fore-Hmb,  vnMi'dilaUir  fibre«  bdng  abnot.  But  «oni^ 
tiiitra  u  iJi&Kiit  revolt  in  obtninerl ;  mi  ntiniuliitinf;  the  divided  acinlic  nerve 
thv  vcaMila  of  tlie  fo"t  an-  not  t-unatricttfl,  but  dilaluil — |>crhniionttielv  iliUted. 
And  this  vn:«ii-diiiilor  ailion  is  alnuttt  sure  to  be  nianili.-»l«'d  when  tlie  nerve 
is  divided,  mid  the  pciiiihemi  stump  Bliranhiled  Ajnu-  dny»  after  diviiion,  by 
nhich  tim«  comnicucing  degeneration  has  l>egnn  to  interfere  with  the  irrita- 
bilitjT  of  the  ucrvo.  For  exiimple,  if  the  sciatic  be  divided,  nnd  some  days 
afterward,  by  which  time  the  Hushing  and  increased  Icmporniure  of  tbe  foot 
foUowinji  upon  tbe  aection  bus  wholly  or  largely  passed  away,  the  jKripheral 
Mump  be  atimulated  with  an  interrupted  current,  a  renewed  Hualiiuj;  and 
riae  of  teroperattire  iit  the  result.  We  are  led  to  conclude  tliat  the  si-iatic 
nerve  (and  the  aaine  holds  ^ood  for  the  brachial  plexus)  oooiaina  both  \-B0o- 
oooatrictor  and  vaao-dilator  fibres,  and  to  interpret  the  varying  rmilt  a*  dut 
to  varialit'NH  in  the  relative  irritability  of  tbe  two  neu  uf  Hbrat.  The  con- 
Mriclor  fibrca  ap|)eur  to  predominnce  in  thuao  ni-rvea,  and  henc«  vonittrictjoo 
is  th«  more  common  nMiult  of  stimulation  ;  thv  constrielor  fibm  also  *PP*>r 
to  be  iDore  readily  alft-nled  bv  a  tetaniMng  current  than  the  dilator  nbrce. 
When  the  nerve  after  division  coinmcnciv  to  d<«cneriite.  the  cnnclriptor 
libm  lose  their  irritability  earlier  than  tlit;  dilator  hurtv,  so  thai  at  n  certain 
stage  a  stimulus,  such  ns  the  interrupted  current,  while  it  fails  to  atfect  the 
OODStrictor  fibres,  readily  throws  into  action  tbe  dilator  fibres.  The  latter, 
indeed,  in  contract  to  ordinary  motor  nerves  (§4-1),  f\-tain  their  irritability 
after  seotiou  of  the  nerve  for  very  many  days.  The  result  is,  jxrhaps,  even 
still  more  strikiuK  if  a  Dteehani(»I  rtimnliia,  <uch  as  that  uf  "  crimping  "  the 
nerve  by  rejieated  Miips  uith  the  teimon,  be  employed.  Exposuic  to  a  low 
temperature  nj^in  aeetua  to  deju^eas  the  eonstrictore  more  than  tbe  dilaioni ; 
lienoe,  wbeu  tbe  leg  is  placed  in  ice-cold  water  stimulation  of  tbe  sdatic,  e\'en 
when  tJie  nerve  lias  be«n  but  recently  divided,  throws  the  dilator  only  into 
action  and  pniducea  Hushing  uf  the  ikXa  with  blood.  Rhythmical  Mioiuta- 
tlon,  nioroovcr,  of  even  a  freshly  divided  nerve  pmducta  dilation.  And 
there  are  other  fticta  which  support  the  aauie  view  that  the  iivtatic  itcrve 
(nnd  bracbial  plexu»)  ontnin^  Wh  vaao-ooustriclor  nnd  vaao-dilator  Bbrttf 
whii'h  are  diflcreiilly  nflbclcd  by  diHereiil  circumatani^c*.  Wc  may  jmint 
out  that  tbe  caae  of  the  vagus  of  tbe  frog  is  a  vcr^-  analogous  one ;  in  it  arc 
l>o(h  canltac  inhibitory  (true  vagus)  ana  cardiac  augmenlor  (tynipnthclic) 


TASOIIOTOR    ACTIONS. 


278 


ttbm.  biit  thi'  funnier,  like  llit;  vtw^eonHiicXor  fibrtv  in  tbc  scintic.  arc 

fim)<(iuinBDl.  nnJ  vfivciiil  nuuiDS  nie  raciuiretl  h)  altow  Oto  prcMDcv  of  Ihe 
KlU>r. 

In  ll»o  fplanchriio  iMTre  i  iib'lominAl  uplnnchnic)  which  tiipptu*  fibrw  to 
tlie  tiliMxIufocU  of  wi  targe  a  piirt  of  tho  nliiloiitiniil  vioccra,  tbpra  is  abiiD- 
4mDl  •vidvnn-  of  ihp  preKiicc  of  vasn-comtriclor  Hbres.  but  ibo  prceencc  uf 
TMO-ditnior  fibn'c  liiu  uot  yet  been  #hoiin.  Division  iif  this  nerve  leads  to 
■  wulroiug  of  tbe  bloodvnwls  of  tlie  iibiloniin&I  vi*cern^»tiin illation  of  itie 
ncrvr  In  n  con  strict  ion  ;  and,  aa  we  shall  we.  lince  tbc  nnioiini  of  bloud- 

finib  ibii*  fpivenieti  by  lliis  nerve  is  very  large  indeed,  interference  eillicr 
lo  lJi«  tine  ilin<cti«n  or  llie  uiber  witb  its  vHBoniotor  funetioiie  produeea  very 
rkoi  nntlte,  out  only  oii  the  cireulaiiuii  in  the  abdomen,  but  on  ibe  whole 

»]»rtytUm. 

In  Dcrra  jcoiog  lo  muadea  voao  dilKtor  fibres  preitomiiiate :  indeed,  in 
Umw  the  ^neeace  of  any  raso-ootutrictor  fibres  ut  all  has  not  at  pTesciil  lieea 
Mtirfaetonly  eaiablubMl.  Wli«n  a  mu«cle  (.'uutraclti  there  b  alwayn  an 
iBcnaaed  flow  nt  blood  Ihrou^ili  tlio  muacic;  lliia  oiny  he  in  imrt  a  uvcre 
■Mchwiical  reault  of  the  diunge  uf  form,  ilie  ^liurteoiuj;  atkd  tliiekening  of 
tbe  8bn*  opeiiiag  oui  tbe  mtnnte  IiIoucIvvkwIh,  hut  in  not  wlirilly,  luid  prub- 
ably  Dot  nvtn  lar;g«ly,  tliim  prirduct^l.  A  notable  feature  of  va»onaotor 
flbiW  M  ibai,  iu  rerv  iDnnr  c*m«  nl  all  «vrJilii,  their  action  id  not  nflocud  br 
■OmII  or  modcmti'  d<Bc»  of  nrari  *uc-ti  ii«  r<'iii]«r  the  niolor  nervca  of  HtriaKa 
mwde  |iowerl«».  ThiJ».  in  a  frog  plaotx]  niitlcr  the  inflnenct!  of  n  motl«nit« 
■■iniiiH  of  umri,  ftiinuIiUion  of  K  nervv  gi>ing  to  a  miitcic  will  proditc* 
T— pmcior  »0tc1«  iinuccotnpiinifil  ami  iitioUcured  by  any  eoDtraclion  of  the 
■riatvil  fibm.  By  plncing  a  thin  miiwrlo  of  a  frog,  auci  as  the  mylo-liTokl, 
oiKkr  tbe  micnaconc,  and  witiching  the  calibre  of  the  Kninll  ariericK  ano  tbe 
draahuioa  of  the  blixHi  t]in»ij;h  them  while  tbe  nerve  i^beinf-  atimulated,  the 
wUeniBg  of  ihv  bloodvewveU  aa  the  reault  of  the  fltimulation  mar  be  actually 
ofawmd.  Tbia  ex|)eriment  appe«Ta  not  to  aucceed  Id  a  mauiuial ;  and  it  hna 
bean  anggeoled  tliat  wlivn  a  niniM-k-  euntraeta  soiue  of  the  chemical  pmilijeln 
ai  tbe  laMaboliam  of  the  mmclc  may.  by  direct  action  ou  the  minute  bliHxI- 
apart  from  any  mTviiuK  ageiicv,  lead  to  a  widening  uf  thuae  blomt- 
:  tltia,  however,  ia  doubtful.  \^  ith  regtird  to  vaxi-ciHiiilnc'tur  tibrot, 
tba  onlv  •videnc*  that  thryexiot  io  niuitela)  in  that  when  the  nvrvo  of  a 
nittcle  It  iltvidH  the  blooilvmvl«  of  the  mutcic  widvn,  fouiewhat  like  blood* 
va«rk  of  the  car  aAcr  division  of  the  cervic*!  ayiupnthctic.  This  euggcvta 
the  pmonoe  of  vafir constrictor  fibres  carrying  tnc  Kind  of  influence  which 
we  cwlJn)  Ionic,  leading  to  an  habitual  laoaerste  eonntriction ;  it  cannot, 
hamvnw,  be  ragarded  by  itself  as  conclusive  evidonco;  but  we  must  not 
JlBBil  ibe  (nalter  here. 

Smakiog  generally,  llien,  most  if  not  all  the  arteries  of  the  body  are  mp- 
pJiu  Willi  vasumoior  libres  niniiin^  in  this  or  that  nerve,  the  fibres  being 
«itber  Taso-MoMrictOr  or  vaau  dilator,  and  Mime  nerves  containing  one  kind 
«f  flbna  only,  some  botli  in  varying  jiropiirtion.  Alinoai  every  nerve  in  the 
body,  tbnvfitre,  muy  tie  lu»k<.'d  upon  aa  inllueueing  a  certain  wt  of  bloix)- 

TOirb.  M  goterning  a  vaaeuliir  area,  the  area  heinj;  large  or  small,  and  the 
|ov<fn(nmt  being  csehiKivcly  roiutrictor  or  exclusively  dilator,  or  mixed. 

TAe  Orvne  iff  Va»o-fomitriet»r  anti  VatihdiMor  FSirf*. 

i  189.  Itoili  the  vaso-cou>triclor  ami  the  va«r-dilali>r  Sbrra  have  their 
urigin  in  the  cvntrul  nervous  system,  tbe  «pinnl  ct>rd,  or  the  brain,  but  the 
I  of  tba  two  *ets  apiwan  lo  be  very  differcot. 


274 


THK    VASCL-LAR    HRCUaKISI 


111  lh«  mnniniiil.  bb  far  n«  wf  know  iit  jircscnl.  nil  ihe  v-n*o<^>Mt rid rtrt 
JibrM  fur  tin.'  whoK'  Ixxly  liikt^  liicir  'irigiti  in  t)ie  miiMlf  re^ii>ii  of  itie  ttpioal' 
cord,  or  rather  Iwivc  ihiy  spinal  cnrcl  hy  llie  iioivw  Iwlongin^'  In  tLU  nii<ldl« 
regioD.     TiiiM  in  ilic  iV>i  Ihc  vus»  cinmtrifUir  filtros  nol  onlj  for  tlip  trunk 
but  ri>r  tlio  limbs,  iiciid,  liicc,  timl  tail,  IcKVc  thi>  fpinat  coixi  by  tbe  itnterior 
root«  of  the  spinnl  tiprvc§  rcnchini;  from  about  the  second  doriul  li>  the  second 
lumbnr  nerve,  bnlti  inclusive.     UuRiiini;  in  the  cose  of  eneli  nerve  root  to 
the  mixed  nerve  trunk  they  ps«B  hIod^  the  vieceral  branch,  white  rnoitis 
comniunicnus,  to  the  L-haiu  of  Hplnnchotc  Rnii|>liu  lyini;  in  ihe  ihorax  utd 
abdomeD — the  so-called  thoradc  and  abdominal  sympaltielic  olicin  (Fij;.97). 
From  theee  gSQclia  they  rea<^'b  their  deelination  in  various  nuys.    Thus^J 
tboee  (foing  to  the  head  and  neck  paee  upward  through  tbe  annulus  of 
Vieusaeus  to  the  Imver  cervical  gatiglioti,  and  then<-c,  as  we  hnvi*  «eeii,  up 
the  cervical  dyniiiaihelii;.    Those  for  tbe  abduminal  vSaoera  ihu*  ofl*  'm  bj 
■iotilar  way  to  tht-  abdomintil  sphmuhiiiv  iiervea,  Kij;.  97,  n6'/.  171/.    TboMl 
dMiineil  for  the  arm  lake  thdr  way  by  thu  retmrrent  fihrei<  (^rnv  nini!  cini* 
inunii-unli's)  (Pig.  4S,  r.  v.),  and  so  reach  the  nrrvcM  nf  the  bracoiiil  plesuN; 
wliilc  lli(«e  for  the  hind  leg  joiue  in  a  itiinilar  way  ihrongh  wini*-  portion  of  J 
the  nhdoininat  )iym|<iilhclic  be-iore  they  join  the  nerve*  nf  ihu  ticJntic  plt^xuiL-^ 
And  the  conslriclur  fibre*  of  the  skin  ol  tho  trunk  probiibty  mtch  thu  ■pinnl 
ncrvw  in  which  they  nUiimitdr  run  in  n  niinitnr  niaiinpr.     All  the  vaso- 
constrictor Bhr».  whatever  iheir  destiiinlion.  Irnvc  iht'  spinal  cord  l>r  the 
anterior  rool«  of  spinal  nqrvet.  and  then  pae<iny:  through  the  np|iro|irint« 
visceral  branches,  join  the  thoracic  or  nbdomtnal  chaiimf  spUnchnie  ganglia. 
In  these  ganglia  the  fibres  undert'o  a  remarkable  change.    Along  the  anterior 
root  and  along  the  visceral  brancn  they  are  medullated  tibrcs,  but  long  before 
tliev  reach  the  bloodvee^ls  for  which  they  arc  destined  ihey  become  oon- 
Diedullated  fibres;   ihev  appear  to  lose  their  inednlta  in   tbe  »\g[em   of 
uilauftiiiii-  ganglia.     We  may  add  ttiai  in  the  anterior  roots  am)  along  tbe 
viiceral  branches,  white  rami  ciuumimicantee,  theie  fibres  are  invariably  of 
small  diameter,  not  imin^  than  1.^  »  to  :i.6  u. 

^  170.  The  courye  of  tb<-  viu>o  dilator  fibru  appears  to  bo  a  wholly  ilifl^rciit 
one,  though  the  delaiU  have  nj>  Vfi  been  fully  worked  out  in  the  caw  of  few- 
of  tbe  fibres  only.  It  is  cbieHy  in  ihv  nirrves  bflunging  to  ihe  craiiinl  aod 
ncral  regions  of  lh<'  central  nervous  system  uiivnce,  ns  wc  have  nen,  no 
vaso-conslrictor  fibres  are  known  to  iwrn-.  that  the  ononw  of  the  vaso-dilator 
fibres  has  been  succcsffully  traced.  Thus  the  vasodilator  fibre*  fiir  the  sub- 
maxillary gland  running  in  the  chunla  tymnani  may  he  tractvl,  a*  we  bava 
seen,  back  to  the  facial  or  seventh  iieri'e:  and  the  continual ii>n  oflbe  chorda 
tyinpani  along  the  lingual  nerve  to  the  tongue  contains  vasodilator  librca 
for  that  organ;  when  the  lingual  is  siiutulatciJ.  the  bloodvo»vU  of  the  tongue 
dilate  owing  to  the  stimulaliou  of  tbe  conjoined  chorda  tympani  fibres.  Tbe 
ramus  tympanicua  of  tbe  gloaso-pharjrogeal  nerve  contains  vaso-dilator  libr«B 
for  the  parotid  gland,  and  it  appears  probable  that  the  trigcniinal  nerve 
oouuiiiis  vn.*o-dilator  fibres  for  the  eye  and  nose  and  po<eibly  fur  otlier  parts. 
Fu  the  anti-rior  raoia  of  tbe  »ec"nil  and  third  sacral  nerves  run  va«o-dilator 
fibrw  whirb  \>»s»  into  the  wi-called  ueri-i  erl^tnlts,  the  nerves,  stimulation  of 
which,  bv  leading  to  a  tvideiitng  of  the  arteritis  of  tbe  peuis  brings  about 
tbe  en-rlion  of  that  organ,  the  effevi  l>eing  uMisied  by  a  simultaneuus  bind- 
ranee  to  the  venous  untAow,  Though  vasodilator  fibres  are,  as  we  have 
Been,  present  in  tbe  nervM  of  tbe  limbu,  and  probably  al^)  in  thuie  of  tbe 
trunk,  the  investigation  of  their  several  path*  r»  renderfti  very  difficult  by 
the  oiucumitant  preeeiicc  of  vaso-eoiislrtclor  labn-si.  There  are  some  reaaniis 
for  thinking  that  the  vaso  dilator  libre-*  in  tliiw  nervev  putKue  a  direct  GOUne 
from  tlie  spinal  cord  throu<;h  tlf  lUitcHor  sjunul  roots,  and  thus  afford  a 


VASOllOTOR    ACTIUN'tf. 


■275 


tnn  with  the  coDilrirlor  fibn.«  of  ibe  nme  n«rrw,  whinh,  at  ire  bare 
iBon.  Mko  >  rmiiKblxMil  niiinw.-.  piiMiiti}:  into  the  »pl»nchuic  sysieni,  l>ef<tre 
Ihty  JMB  tbv  norve  trunk.  Our  inl-irnniliuii.  Iionev-Qr,  U  loo  imfierl^i^t  (o 
bUow  an?' Vviy  poeilivc  HtmeOK^nl  to  be  mu'le.  Accepting;  thU  viow,  how- 
*v«r,  w«  may  say  that  while  all  the  va<ri>'Coii<(riclrjr  fibres,  a.4  I'ur  iis  vic 
know,  come  from  it  iiarlii'iitar,  lliiitigh  consiilerable,  pari  of  the  sjiinal  ruril 
•IhI  pBW  into  ibe  splaiirhiiio  system  uii  their  way  to  their  Mveral  deitiiiii- 
tioaa.  ibe  vaao-dilaior  fibres  arise  from  all  parts  of  the  jipinttl  conl  as  well 
■a  fr^Mn  the  inealulla  obloo)^(a,  aod  puraue  a  mure  or  leu  ilirecl  omw  to 
Ibeir  (le4inKti»n. 

Kuribw.  while  the  vaso-diluior  libra,  a*  they  leara  the  central  ncrvnus 
antem.  are.  like  the  va*i-ci>itMri(.-tur  llbriM.  tint;  inmlullated  libr<»,  unlike  the 
vaao-conHrietur*  iher  n-taiu  Ibeir  luvilulla  for  the  ynuiler  {Wrt  of  tlu'ir 
«oanv,  and  only  Iom  ii  m-ar  thvir  lertuinatiou  in  the  tiHiie  wliow  blovd- 
WHlt  ibi'v  Kri[)ply'. 

LaMlr,  while  in«  riiM-con«tricl»r  fibreii,  a*  in  ih«  cam  nf  the  cervical 
■TRipalbvtic,  of  the  ntdlDiiiinal  >|iliinchuic,  aui)  of  the  ncrvni  of  the  skin, 
ax»i]  |irotMi]>ly  tn  nil  iiwrs.  utv  mirinully  in  a  ulato  of  moilctatv  activity  (ta 
Imw  aa  liwy  mninin  in  i-onni-ction  witb  ttie  oeiilral  in-rvout  nyslcni),  llie 
Boomu  aclirily  maialainini:  that  nKHlerate  coni*lriclioii  which  wo  spoke  of 
abnrv  a«  "toiic,"  the  vavodilntim  nppear  to  fioaiMi  no  such  continued 
activity.  i>ccttun  of  vaR»coiisi riclor  hbr«-«  lead*  to  loss  of  tone,  diminutinn 
of  cimrtrictioo,  lA»ting,  as  we  shall  eoo.  for  some  coniirleruble  time:  but 
aecliun  of  vaso  dtlaion,  nccordiu;  at  all  events  to  must  observeni.  doe*  not 
iimti  in  aDalot;ouD  eonslrictioii  or  iliniiniilinn  of  dilation  ;  all  that  U  obierved 
ia  a  tnasieoi  increase  of  dilation  due  |tfub,tbly  to  the  section  acting  as  a 
tnuatnil  stimulus  tn  the  nerve  at  the  plscv  of  section.  But  before  we  study 
tb*  uaa  made  by  the  ceiiiral  uen'ou^  syitem  nf  va»imotor  ncrvt^ii,  it  will  be 
bcac  to  cnn«ider  briefly  some  teaturea  of 

Ci  171.  A  <rery  Utile  coiuideration  will  show  that  vasomotor  action  is  a 
■  Inpoftant  factor  in  tbe  circulation.     In  the  lirst  place  the  whole  flow 
bloiNl  in  the  body  is  nflnptGd  to  unil  governed  by  what  ire  may  call  the 
fiMH-al  iotu  of  the  arteries  of  the  body  at  large.     In  a  aamal  oooditiua 
of  iIm  budy  a  very  ^*T\fe  Dumber  of  tlic  minute  arteries  of  the  bmly  are  in 
a  state  of  toaie,  i. «.,  of  modwate,  coiilrii<.-tion,  and  it  \a  iht  narroniug  due  to 
thia  eontraolioti  which  form*  n  lar^e  item  of  that  peripheral  raei«tanoe  which 
mm  bave  seen  to  be  one  of  the  k<'c^<»  factors  of  blood -preasure.    Tbe  Donnal 
Munl  b!(Kid-i)rui»ure,  and,  ttiert-fore,  (he  normal  flow  of  Mood  is  in   fact 
r       Smodent  on  tbe  "  general  lone"  of  the  miuute  arteriea. 
fe        In  tbe  SKcnd  p)ac«  local  vaitotnoior  chauKea  in  the  cundition  of  the  minuta 
V     sileriea.  changa,  i.  «.,of  any  particular  voneular  urea,  have  very  decided 
fflccts  on  the  carviilation.    Th«Ae  changes,  thouj^h  lut-ul  theuutelves,  may 
bave  HiecU  which  arc  both  local  and  ^neral.  as  the  fuUowiug  consideratiotu 
will  elmw : 

Let  IIS  suppwr  that  tbe  artery  .4  i«  in  a  condition  of  normal  tone,  is  mid- 
way  between  psirvme  conrtrielion  and  dilation.  The  tlow  thr>Hii(b  A  is 
dm  I  mil  lid  by  ilte  rtvistanci'  in  A,  and  in  the  voseulur  tract  which  it  luji- 
plios.  In  relation  to  the  miain  iirienal  preuiire,  whicbaznin  U  dependent  on 
tbe  way  in  whit.-h  the  hi-arl  in  bentimc  and  on  the  poriphenil  r<t*i»tanoe  of 
■11  tbe  small  arteriet  and  capillarii'v,  A  included.  If,  while  the  heart  and 
tbe  rwt  of  tbe  arteries  remain  unchanged,  .1  bo  const rtcted,  tbe  peripheral 


The  ^«U  of  t'oMiiHoUtr  Attioiu. 


276 


THB   VASOULAR    UBCHA<t!«». 


Tn>!»tunr<'  in  .l.will  nirri-ii:>r,  mxl  tbiti  inrraiJN-  'if  rtnttaDM  Will  Imd  to  kU 
iiicnni'c  of  lln-  gcm-nil  rirlcriiil  )>r(-.'<i'urc.  Sitiw.  nt  w«  h«T«  seen,  §  119,  U 
!r  iirkTiiil  |>ri.'N>iin-  wliii;)i  i%  ilic  imnicilliiti?  cmwc  of  ihe  (low  from  Xhv  unprk-e 
to  llic  vrin*,  thi»  incrcnsc  nf  nricrial  [irwmrc  will  lend  to  drive  piore  lUood 
from  llic  nrliTk-»  inin  th<f  vtiiw,  The  c<>tistricUni]  of  A,  hotrevcr,  bv  in- 
crcaciug  l.hc  r»iiiliint-<\  oji|)')Ki'  nny  increase  of  the  flow  through  A  iUvlf,  in 
ftct  will  mitkc  the  tiov>  through  .4  lew  than  bcibre.  The  whole  increase  of 
difchnrgc  from  Ihr  nrlcriul  into  tbt>  venous  FViilctii  will  take  place  through 
tbc  iirtcrics  in  which  the  rreistance  rcmaioe  udl' hanged,  tbut  is,  througll 
channels  other  thun  A.  Thus,  ns  lh«  resiill  of  the  constriction  of  any  artery 
there  occur  (1)  diminished  flow  through  the  arleiy  itself,  {1i  increased  gen- 
eral arterial  preeeure,  leading  to  (^)  increased  flow'tbri>ugh  the  other  arteries. 
If,  oo  the  other  baud,  A  be  dilated,  while  the  heart  and  other  nneries  remain 
unchanged,  the  peripheral  resistance  in  A  is  diniint^bed.  Thin  leads  to  « 
lowering  of  the  general  arterial  preasiire.  which  in  luro  lends  to  drive  leaa 
blood  from  the  arteries  into  the  veins.  The  ditaiion  of  .1,  however,  by 
diniiniBhiug  the  resiaiaucu,  jjerinils.  even  «iili  the  lowt-red  prei^ure.  mors 
blood  to  ])ai«  through  A  itself  than  before.  Hence  the  dlniini^biMJ  flow  lelU 
ail  the  mure  on  the  reiit  of  the  flrteritrs  in  whirli  iht-  ret<i«tance  rcniiiim 
unchanged.  Thus,  aa  the  ivkuU  of  the  dilation  uf  any  nrtvry.  tliorc  mu-ur 
(1)  inert-used  flow  uf  blood  through  thi'  iirliTv  it>elf,  (li)  diniiui»hi-d  gciiemi 
prwiiure,  and  (3)  diiuiniiihed  IIoir  through  Ihr  ni'ier  urliritw.  Whi'ro  the 
artery  ihun  cunitiricted  or  dilated  is  --mall,  iho  Wal  cllecl,  tin-  diminution  or 
incnMe  of  tluw  through  itself,  is  much  nu>rit  jmirltrd  tlmn  the  general  cffi.t'lf, 
the  diangu  in  blond -premurc  and  the  tlow  through  other  nrtcrici<.  Wbcn, 
howdver,  the  area,  ihi;  arteries  of  n'bich  arc  alfcctcd,  i*  large,  the  genera] 
eflcclit  arc  very  striking.  Thus  if  wbilr  n  tniniie  •4'  ibc  blood- prra* lire  it 
being  lukin  by  nienns  of  u  roiinomclvr  connected  with  the  carotid  artery, 
ifafl  abdominnl  splanchnic  nerves  be  divided,  n  conspicuous  but  steady  tall 
of  prenure  is  obeerved,  very  similar  to  but  more  marked  than  that  which  is 
Men  in  Fig.  ^if.  The  section  of  the  ubdoniinul  splanchnic  nerves  causea 
the  mesenteric  and  other  abdominal  tirteries  to  dilate,  and  these  being  very 
nuuerouH,  a  larse  amount  of  peripheral  resistance  Is  taken  away,  and  lli« 
blood  preeeure  JallK  accordingly;  a  large  increase  of  flow  into  the  portal 
veiiis  takt-a  jilace,  and  the  supply  of  blood  lo  the  face,  arms,  luid  legs  ia  pro* 
portioniiUy  diminiBhed.  It  will  be  observed  that  the  dilation  of  the  artrriea 
Is  not  insianisneouH  but  somewhal  gradual,  as  shown  by  the  pretaiire  sinking 
not  abniplly  hut  viith  a  gentle  curve. 

The  general  etlecls  <iu  nlmid-pressuie  by  vawimotor  rhaDge»  are  ki  marked 
that  the  manometer  may  be  used  to  detect  vasomotor  action*.  Thus,  if  the 
stimulation  of  a  narticular  nerve  or  any  uther  o|K-niiion  leads  to  a  marked 
rite  of  the  mean  iilood-preft^ure,  uniicrompiinii-d  by  any  changes  in  the  he«n* 
beat,  we  may  infer  that  constriction  bat>  taken  place  in  the  arteriec  of  tKxnc 
Conriderable  vain'ular  nrt-ii;  and  similarly,  if  the  eHi-ct  be  a  fall  of  blood- 
prewure,  we  may  infi-r  ihiit  constriction  him  gtve:i  nay  to  dilution. 


Vatomolor  funtiieit  of  the  Ventral  Jicniwu  Sutton, 

^  ITS.  The  central  nervous  Kysteni,  to  which  we  have  i.niced  the  vasomotor 
OCTves,  makes  use  of  theeo  nerves  to  regulate  the  flow  of  blood  through  tbe 
Tarii>us  organs  and  parts  of  the  body ;  by  ibe  loeal  elfecta  thus  produced  il 
artiitB  or  otherwise  influences  the  functional  aetiviiv  of  this  or  that  tisane ;  by 
tbenueral  eflfeota  it  secures  the  well-being  of  the  body. 

Tm  use  of  the  vaeo-dilatur  nerves,  which  is  wore  flm{ile  tliou  thai  of  the 


VASOMOTOH    ACTIOS*. 


nwMUlriclofs  «nw  it  ii|>pi-iLr»  not  in  )i«  c»mplt<-ntc<l  I>r  (lie  |>r»jeiice  of 
htUtiwI  Utaw  infliMiK-cs.   in  friMiiiitilly  (.-unfliiii-umis  bh  pAit  of  n  reilex  act. 
HiB^whi'ii  ISkh)  is  plneeH  in  lliif  miHilti.  atf«rciit  itiiiKiliM?^,  (*euorat«')  in  thai 
■Kn*  of  taste,  give  rite  iii  tW  cniitrnl  nervous  system  ta  eflerent  iinpiiUM,  j 
■tich  dM<wn<l  tne  chorAn  iytD|Miii  and  other  nerves  tu  the  salivary  i^landfl^ij 
ml,  hr  diluliii;;  tlie  tilnoctveescls,  secure  &  copious  How  of  blood  ihrnuKh  the  ' 
|Iiadt,  nhile,  na  vre  sli*)!  see  Uler  on.  they  excite  ibeni   to  iH>r'rele.     Tlw 
mlnof  thii  reflex  actioo  njipears  to  lie  in  tho  iiieiliilU  oblootcata,  and  tiiiijr 
b  throVD  into  acliviiy  not  only  by  irupulites  reaching  it  aliin^  the  s|)ec-i6c 
w&imot  Uste,  but  nbo  by  imputsoi  puasiiit*  iiliinK  other  chumeU:  thiu, 
■DMkni ftartad  tn  t)>e  hruio  by  the  Bitrht  of  Ibod  or  otherwUe  may  cive  riw! 
k  iwfiiliM  pttninit  dowD  kIohk  the  oentral  aurvou*  Byfltcm  ilMlf  t^  thai 
■daAi  oblangHta.  or  eveata  in  the  atomach  nuy  send  iranutnes  u|>  the  vagiNiJ 
Mr*«,orUiniulBiion  of  Olio  kind  or  another  may  Miid  impti1^4±i  itp  nlmoftl 
UTMBtiwit  nerve,  nnd  the^^  various  iiupuUoii  n^ai-hin^  the  mi-ilullii  iaiiy,hfl 
MnMtkwi,  thmvrinto  aclivitv  thvrttiiii-dilaior  filinaorilicvhunla  tyinpunlj 
nd (titer  Kualngou*  nervesi,  »nil  bring  ubnui  a  l1iiT>hin);'if  thrr  aalivary  gluudi, 
«hilt  It  tho  (Uiie  lime  ihry  ntUM-  ibu  ^Innds  In  KWreiv. 

Ibe  irMu^ilator  fibr<»  i»i'  the  nervi  crigenirti  may  !>«  throwii  into  aclUlt^ 
hianitsr  reflex  way.  the  c^nlrv  in  this  cn*i'  l>cing  ptac^l  in  thu  himbiir  or 
Inrwilorvl  txirtion  i>fth).<  spinal  wrd.  though  it  is  wwily  thrown  into  luitivitj 
h  iiiipuliMw  d«Kending  donrn  the  spinal  i;i>ril  from  the  brain;  that  such  • 
nwie  doce  cxit>i.  in  shown  by  th<^  fact  that  wh«i  in  a  dog  the  spinal  cord  it 
ONDfiliiely  divided  in  ihe  doreid  rvjjioii,  erection  of  tho  penis  may  remlily  bft 
t(M^  about  hy  Blimiilntion  uf  the  sentient  surftces.  And  otlior  instancw 
■ijglit  be  ijuoted  in  which  rnsi>^ilaiur  fibres  appear  to  be  connected  with  a 
'tntn  "  atMin  after  their  entrance  into  the  nervous  ayBiem. 

If.  a*  Mcm«  pnilKible  {$  in'  I.  the  bloodveMftls  of  a  tnuacle  dilate  hy  vaan- 
maUtr  action  whenever  the  muscle  U  thrown  into  conlraeiton,  either  in  a 
ftSex  or  voluntary  movcniful,  thr  va»>-dilatur  Bbret  of  the  miiitcle  would 
(MB  to  bo  thrown  into  action  by  imjiiilM^  arising  in  the  Npiiiiil  cord  not  Air 
ftom  the  origin  of  the  'inlinary  motor  impnlxtt,  and  accompiuiying  thuM 
Botiir  IfnpalM  along  Uie  motor  avrre. 

i  ITS.  TheotMoftbe  vnAo-conMrietorlibreallMfnewliaiinoreoninpliiMtm), 
(D  account  of  tile  exiKtrncc  of  tonic  influcmcea;  sincis  the  sam«!  tilirra  may,  on 
iWitnn  hand,  by  an  incrtwMT  in  the  imnulM*  passing  along  them,  bo  tlie 
■wan*  of  ronftri<.-t>oD,  and,  on  tlic  other  hand,  by  tho  n'moval  or  diminution 
of  the  tonir  inllucncw  passing  along  them,  be  tJw  incunK  of  dilation.  We 
ka**  alrvady  trau.-<)  all  the  vaso-canstrictor  lihrM  from  the  middle  region  of 
the  spinal  cord  to  the  splanchnic  system  in  the  thorax  and  abdomen,  from 
■beacr  tbey  {was  (i)  by  the  abdominal  eplnnchuic  and  bv  ibe  hypogastrie 
aWTM  to  the  vsMCra  of  the  abdomen  and  pulvis  (oonceniing  the  vaaumotor 
■■rvea  of  Ibe  thoracic  vi»oera  mc  know  at  present  very  little):  (2)  by  th« 
wrvicnl  sympnlhelic  or  cervical  'Splanchnic,  a^  it  might  be  called,  to  the  skin 
id*  I  he  liead  and  neck,  the  •alivary  ^lauda  and  mouth,  the  eyee  and  other 
|Mna,and  probably  tbe  brain,  including  ila  membranes:  \'-i)  by  the  brachial 
md  •ctniic  pk'xuaea  to  the  skin  of  the  fore-  and  hiud-limlw,  and  by  vanoua 
nther  nervea  t<>  the  skin  of  the  trunk.  Tlie  chief  paru  of  the  body  tuppllad 
hr  ira«o-couurictor  librcn  ap|>ear  to  be  the  «kiu.  with  its  appendages, and  the 
aiiaKQlary  canal,  with  its  appendagai,  glanduhir  and  other:  tlw  great  maaa 
of  akeletal  muanle*  npjioara  to  raoelre  an  iniiignifieant  kupjdy  of  Tiiao.eoo* 
Mrietor  llbrcf,  if  any  at  all. 

If,  DOW,  In  aji  animal,  the  «]>inal  ooni  be  divided  in  the  lower  dorwal  region, 
iba  •kin  of  tJlO  leg*  bcoomM  Huxhcd,  their  teniiMmtnn:  rrc<]uently  riw»t,  and 
tlMT*  la  a  certain  amount  of  fall  in  the  general  blood-pruMure  aa  inea«ured. 


278 


THE    VAi!Cl'I.AU    MBClIANtKU. 


f»r  instJiiico,  in  tlic  rnrotid ;  iiud  Uii»  slnt«  uf  things  miiy  lui  for  tomt  oon- 
tidcnible  time.  Ol>vii>ii»ly,  tliu  Melton  of  the  »iiiniil  «>rd  lins  cut  ul)'  lite 
utiiul  tonif  intlucn<y«  ilccpiiiliii^  to  (In-  InwiT  limlM:  in  c»nMi|U(^tn>  the 
bliunlvowls  liBV(!  bccomi-  ililnlcil.  in  eonwjuenct'  ihp  gcnerni  periphcml 
rreisluncc  lin»  bccpniv  pro|i<>rtioii7tl«lT  (limiiilehod.  nn<)  in  con»ci|iieiivo  lira 
^ocriil  hlodil-pirwiiri'  hfi»  fnllcn.  The  tonic  v a fH' constrictor  iiupultes  lor 
tlie  tower  limbs,  lliorelbrc,  linvc  their  origin  in  tl>e  ccniral  nervous  sjsloni 
hipher  up  llinn  the  lower  tlorwil  rofjion  «f  ihu  i^pinnl  eord. 

tf  ihe  cplnol  cord  bedividti)  between  the  rooiiof  tiie  tiflli  and  sixth  dorsal  ■ 
nerve;  i  iJiat  is  to  tay.  nt  ihc  level  where  the  path  of  ibe  Hplanchiiic  fibre*] 
from   the  cord  eeenis  to  divide- — tee  Fig.  ill — iliose  iK^iiini:  above  iMniog^ 
UDward  to  the  fore-lioibe  and  liend,  and  those  isauiiig  below  jiawtn^  to  the 
aodomen  and  lower  limhe).  the  cutaneous  bloodveaseU  uf  the  lower  limits 
dilute,  as  iu  the  former  case,  and  on  exaniiiiali»n  it  will  be  found  that  the 
bluodvesEeU  of  the  abdonien  are  also  largely  dilated ;  at  Uie  same  tiine  tba  | 
Miiiid -prewure  uuderjfoee  a  very  marked  fall ;  it  may,  indeed,  be  reduced  ut 
n  very  few  niillinielres  of  mercury.    Ohviounly,  the  Ionic  viuK)-c<«wtriclor 
■mpuWii  passing  to  the  abdotnen  and  to  the  lower  liniliti  lake  origin  iu  the 
itnlral  nervous  ayetetn  higher  up  than  the  level  of  the  lil\h  donal  nerve. 

If  thenectioDof  the.iphiul  curil  be  made  above  the  level  of  the  M-cund  lUinwl 
nerve,  in  uddilJon  to  ihe  a Imre- mentioned  rt-sull*  the  vcvscU  of  thi-  head  and 
fact-  alMi  liccume  dilatctl :  but.  in  I'unsequence  of  the  fall  of  general  bloixl- 
prcwurc  just  m<-nli<ini'd,  these  vt^sel^  never  liecome  mi  full  of  hlnod,  the  hiKsof 
tone  H  not  to  ol>viou»  in  ihem  iu<  after  simple  division  of  the  ecrvical  syniim- 
thfflic,  since  the  bitter  opcTation  [irt)duce7>  little  or  no  etH'ct  on  the  general 
blood -nrnvH  re. 

Ol>vinu»ly.  then,  the  tonic  va«ii-coii»triclor  tmpiilees.  which  pDs*ing  to  the 
skin  and  vioeera  of  llm  body  riiiiint:iin  ihnt  (onir  niirrowing  of  so  many  small  i 
arleriea  by  which  the  general  [Kiiplieral  renislance. nnd  so  the  general  bloud- 
preoHire,  is  mainlaiucd.  ptoceeil  from  some  part  of  the  ec-ntml  nervous 
System  higher  up  than  :be  upi>or  dorsal  region  of  the  tipiiml  conl.  And, 
since  exactly  the  aaiue  results  follow  upon  section  of  the  »pinul  eord  in  ilie 
ccr\-ical  region  right  up  to  the  lower  limit  of  the  mnlulla  oblongaiu,  we  iuler 
ihal  the-ie  ionic  iuipul&es  proceed  from  the  medulla  oblongaia. 

On  ihc  olher  hand,  ne  mav  remove  the  whole  of  the  brain  right  down  In 
the  up|>er  parla  of  the  medulla,  and  yet  imiduee  no  HuBliiug,  or  only  a  slight 
Iranpicnt  flij>liing,  of  any  jinrl  of  the  bu<]y.  and  uo  lull  at  all,  or  only  a  xlight 
tn<ni>i('nt  fall,  of  ihe  general  blood-prei<snre.  We,  theivl'ore,  Mem  jiiMifii-d  in 
astuniing  the  exiiiience  in  llie  mediillii  oblongata  of  a  ucrvouii  eenlre.  which 
Wt  may  e[K-ak  i>r»ii  a  I'lmointitor  fmlrf,  or  the  inrtlullur^  ruAnnwlof  emlrr.,  from 
which  [lojcnil  tonic  vBKo-consirictor  impu !»':>, or  which  regulates  thcmiiaBioa. 
and  dittribulion  of  Kiicb  tonic  viixo-eoti  strict  or  impuleca  ur  inlhiences  otef' 
various  purls  of  the  hiwly. 

S  174.  Theexislem-e  of  tliis  vawmotor  centre  may,  muri'over,  beshowit  in 
another  way.  The  extent  ur  amount  of  the  tonic  eonslrietor  impulses  pro- 
ceeding from  it  may  Im  iucrcawd  or  diminished,  l\w  activity  of  the  centre 
may  be  augmented  or  inhibited,  by  impulses  reaching  it  along  various  alfereni 
aerves ;  and  provided  no  marked  changes  in  the  lieart-beat  take  place  at  the 
Him«  lime,  a  rii^e  or  fall  of  general  hloiHl- pressure  may  betaktu  as  a  token  of 
an  inensnw  or  decrease  of  the  activity  of  the  centre. 

In  the  rabbit  there  is  found  in  the  neck,  lying  side  by  side  with  llie  cervical 
symiiatliniic  nerve  and  running  for  some  distance  iu  conifiaDy  with  il,  ft 
slender  iiervo  which  may  lie  ultimately  traced  dnwn  tu  the  heart^  and  which 
if  traced  upward  is  found  to  come  olT  ^lomewhat  high  up  from  the  vagus,  by 
two  or  more  roots,  one  of  w  hich  in  geneiully  u  brunch  of  the  «u|ter)or  laryn< 


TA!)0irOTO1t   ACTtOXS. 


^nkl  aCT\t.  Thti  wrvv  ithv  Hl>re»  ooiiMiluling  which  Air.  iti  thsdcig, bound 
up  mixh  iIm>  vn^iiD  soil  il»  nut  loriti  nn  indcficiiili-Tit  iivrvcj  npptUi  to  bo 
rxrlunrrK  on  ulTeifnt  Dcrvc;  when,  ufter division  of  ihi.- nerve  tlm  pfri[il«'riil 
rml,  ibr  r'nd  Alill  in  «>nnLvlioii  wiih  llie  heart,  i»  HlimuUttx).  nu  iuKrk«J 
nwuli*  fi'lliiM  Tho  hnriiinius)!  uf  ibu  uervc  in  the  heart  nre  lli«rvfiin-  (juilc 
tUdaratt  fniui  ihi-  ouilin)^  of  lh«  inhihilory  librw  of  the  vngue,  i>r  of  ihi; 
■anMntor  Rhm  of  thu  >>|>lniidinic  (i>vm|>alhelici  syBlom  ;  ihc  nerv«  hiM 
OdthinK  I"  do  iiilh  (h«  nvrvouii  n-gululion  uf  the  heart  [tee  pp.  '240,  rt.  m^/.) 
If.  n.ni.  while  the  prewure  in  »iii  iirtery  ituch  lu  the  carulid  ia  being  rvgislurwf, 
iht  nrulral  eud  of  ihe  ntri'e — i.  *.,  tliv  one  eonnecteti  with  the  brniit— bo 
Biituulaied  with  the  intcmiplnl  eurrviil,  a  gratlual  but  nmrked  fall  of  pr«»- 
atm  {Fig.  99}  in  the  carotid  is  oliM-n,-cd,  tttnling,  wli«n  (he  period  of  «timu- 


rro.  ». 


/'"^■^Lr^ 


^ 


TKMna  Saovmn  t«b  Erncr  on  DimiIkphmmtu  or  SnmuTtMn  Tin  CRnK4i.  dft  or  ma 

DU-*B*nK    NUtTK  IH  mi  KlBOIT. 

!)■  ttm  Ume  writer  t»etow  the  Iniwvl*  iiomiponA  to  letiinila.    AI'ialnwnvploloDrKMwai 

tfercnim  iMlii  Uio  nelrc 

latinn  is  sbort,  tatae  linte  ai^er  the  rviuoval  of  the  ftimulus.  Since  the  beat 
of  the  heart  ii  not  markedly  changed,  the  tiill  of  presMire  niuat  be  due  tn  thv 
•lininiition  n(  ji^riiihera)  reMslauce  occsuoDed  by  lite  dilation  of  ■onw 
ulcnr*.  And  it  ia  probnble  that  the  arleriea  lliiis  dilated  are  cbiefiy,  if  not 
tmludreljr,  thn»e  nrieriei  of  the  abtloiuiiinl  viscera  which  ar«  jcoverued  by 
tha  abdonilnal  iplaiichnic  i)i'r%'t? ;  for  if  iheM  iierves  are  divided  on  botb 
lUt*  prnt'iova  t'l  lite  ex]>i'rimt'ni,  the  fall  of  nr«aBur«  when  the  nerve  la  Miinii- 
lalrd  !■  very  »mnll — in  fad,  almost  insignificant.  The  inference  we  draw  b 
a>  fidlnw*:  TIr-  alR-rvni  impiilxra,  pamns  upward  along  the  nerve  in  ijuesiion, 
hare  mi  nlfu-<-li-d  Nimu  part  i>f  ihc  centmT  nerirou*  xYSiem  ihat  the  inducnces 
•hirh.  in  a  U'inmil  comlilioii  of  thing*,  pajsing  along  tW  nbdominal 
tplanehnif  iiitvc*  keep  thi'^  minute*  artt-ricM  of  thv  abilniiiiiinl  vtKX'ra  in  a 
NaitT  of  Tnmh-ralv  liuilc  conolrirtinti.  fail  altogether,  and  tlii<w  arlcrieo  in  con> 
wqaeorv  dilnt<'  ju:>t  an  tlii-y  do  nhrn  th«  abdontiDiil  Miilanrlmie  nervM  arc 
ifivided,  ihe  elR'cl  Iwiiig  |H>r»itity  iiivreaM>d  by  ibe  tinnlar  ililatlon  «f  ntlwr 
TMTuIar  Hrraa.  Since  vlinulalion  of  tlie  ucrw  of  which  we  an-  niiraking 
il«ay*  produce"  n  fall,  never  n  rise  "f  bloo"l-prfMure— the  amount  of  fall,  ot 
eoarre.  l>cinF:  di-|>cndent  on  circii  to  stances,  luch  a«  the  condition  of  the  ncr- 
rmn  ayetcm.  i^in  of  blood -premirc,  etc. — the  nerve  if  known  by  tlie  naiiw 
••f  the  dffr'j>M>r  nerve.  At  we  »linll  point  out  later  on,  by  means  of  thw 
■Ami  n«T\'«-  from  the  heart  the  peripheral  rHislnncc  is,  in  the  living  body, 
lowered  to  euit  the  weakened  powers  ><f  a  laboring  heari. 
Tbbgndnal  towering  of  bluod-prasure  by  diminntion  of  peHpberal  reabt- 


S80 


TBE    TASCULAR    ȣCUAKISM, 


Moe  nnunln  n  ninrkM  contrast  tn  thv  eii<ld«n  l<tweriiiK  uf  bloinl  presuira  bv 
cardiiii-  inliiliilioti ;  i-i.ni[niri-  Fig,  Hfi  wiih  Fig.  fl.*. 

S  17fi,  But  tliF  gi.-iiernl  til(io:)-)>rPmiiri?  inny  be  moHilier]  by  afl«r«(il  iriipulMfl 
paaio"  iiloiig  lilhcr  iicrvc*  than  the  clepr*?aKir,  the  mixliHi'aiti'iu  taking  on, 
aecdruiiic  (o  cin-iiMifiluri<;oe.  the  fttrcii  eillier  of  deiTEUue  i>r  of  iiicrviue. 

Thus,  if  ill  un  iminial  jiliii.'e<l  iiuilvr  the  iiiniience  of  iiran  (triine  nitiNlIietic 
othor  thnn  L-hlural,  eu'.,  beiug  uwd)  ihe  ceiitrul  stumj)  of  llie  dlvideil  M-iatic 
iKrve  be  eiiiuulaled,  an  iiicreaite  uf  hliHid-|in«aure  (Fi|(.  100)  aliuoat  (.•xuotlj^ 


Klu.  1(0 


JW.VywWWW*WV' 


,;,^r^ww^^ 


^ww^^v.----^-^^^ 


X 


EmcT  0.1  BUMihritiMnniK  Crnvs  ov  Bnm*i.ATiini  Smi-nr  Nuitk  i'nuru  I'niiii-  (c*t.) 

(Durlu  ibc  moDiL-nl  111  which  Itiv  iiimtil  wvlbmwn  liiUilUt  iiurvc.   AninrinI  n»(iliBllaa  «ra* 

carried  un.anil  HiBiimal  napmitniT  tiiiduUIIixivacwsbHiil 

ihe  reverse  uf  the  decrease  braui;)it.  ulxuii  by  »tiniiitnting  the  d«pr«mor,  \n 
oliaerved.  The  curve  of  the  bloo(l-pn?siiire.  iil\er  n  lnt«iil  period  diiriDK 
uhit-h  HO  (-bim);i-'»  are  viaible,  rises  Eteadily  without  any  corratpuitdiug 
L'hauf^  in  the  heiirt's  heat,  reaobes  a  maximum  and  afler  a  while  slowly  falb 
ugaiii,  the  full  winK-liini-'n  beginning  to  apfiear  her<ir«  the  stimulus  haa  been 
rviDoveil.  There  can  hv  do  doubt  tlinl  the  rise  of  pressure  is  duo  In  the 
coii»tri<rtic>ii  uf  certain  Hrteries;  lh«  arleriea  in  (jueslion  beiii^'  Ihuse  of  ihe 
■bdoininal  «pIiuichQic  aivn  ccrlninly,  anil  ixmibly  thiiW!  nf  other  vascular 
■raac  lu  well.  The  cffi^^t  i*  nol  coiilincd  to  ih«  *ciatii!:  niiiuiilation  of  anv 
nerve  oontminiue  afferent  fibreit  may  ]>roduvf  th<>  nunc  rJSL*  of  prcMure,  and 
so  conilanl  is  the  result  that  the  expi^rinicnl  Iiiik  Ih'cii  mitdc  use  of  a*  ft 
method  for  determining  the  existence  of  ulH-n-iit  tihrc9>  in  nny  given  nerve 
iind  even  the  pntbe  of  eeutripct.il  imi>u1s<u  through  the  spinal  ennt. 

[f.  OD  the  other  band,  the  tinifnni  be  under  thu  inHuence  not  of  ururi  Itut 
of  a  large  dose  of  chloral.  in«ieiid  of  n  rise  of  blood -pressure  a  fall.  <{uite 
similar  to  that  caused  by  «tiniij!iiliiig  the  depressor,  i«  observed  utien  ao. 
alTerent  nerve  iMbtimulatetl.  The  condition  of  the  ceutial  nervous  system' 
seems  to  determine  nheliier  the  alfect  of  afferent  impulses  ou  the  centrnE 
Dervuus  system  is  one  leading  tn  an  aiinmeDiation  of  vaso-coniitricbar  impulne* 
awl  so  to  a  riwe,  or  one  leniliug  to  a  diminution  of  raso' constrictor  impuliUM 
and  so  to  a  full  of  UioiHl-prauure. 

5  176.  Wi-  have  uwd  Uie  words  "  wntral  nervous  eysiem  "  in  spoakiitg  ofi 
the  above ;  we  have  evidence,  however,  that  the  part  of  the  ventral  ncrvout . 
ayaieni  actiil  on  by  llie  nflt-reut   impulses  is  the  vitaoniotor  i-eiiire  En  U19 
medulla  nbhmjfnla,  and  that  the  eflivlA  In  the  war  of  diminution  (deprawor) 
or  nf  augmMitatitm  (prewior)  are  thf  reaulisorttfiereut  inipuUw  iubihitiugnr 
tuzinenting  the  tonie  ar-tivitv  of  thisi  et!Ulre  or  of  a  part  of  thin  centre  spe- 
cially oonni'Ctcd  with  nbilomnuil  splimchnic-  nervea.     Th«  whcili>  brain  mnj^ 
bo  rrmovnl  right  down  to  the  medulla  nblonitata.  and  y<it  the  elTucts  of  stimu- 
lation in  Ihe  direction  either  of  <liminMtiiin  or  of  aui(meniaiiuu  may  still  b«' 
brought  about,     [f  the  medulla  oblongata  bo  removnl,  iIkvt  effects  vanish 
tou,  UMMi^h  all  (be  rest  of  the  nc^rvoiiH  svstem  be  letl  intact.     Nay,  nn.irei.  br 
|iWtiaJly  inicrferini;  with  thi-  iiio<lulln  o)tlongiitii,  w<i  may  partially  diminish 
tJMW  enbcta  and  thus  mark  out.  «•>  to  sjh-uIc.  the  limits  uf  the  tvntre  in  ques- 


i 


VABOMOTOlt    ACTIONS. 


•281 


tlno  wllliin  lbt>  tiHoliilla  iUi'ir.  Thus,  in  an  tntiici  lUiiRinl  iimli^r  tirnri.stimu- 
hiioH  of  ihp  KJiitit-  m.-rvo  with  n  flimtilii?  "fit  i-i-rtniii  ulrvtigili  nill  iiivliim 
m  rW  of  bliuid-|ircsHin:  iip  tii  r  rtrtnin  ^siciil.  Afitr  rcnionil  nf  tlir  wlt«l« 
hrain  right  down  to  the  medulla  ubloDunta,  tho  snnic  »tiiiiiilnrion  will  firo- 
■lutT  lh«  nm*  Hm  u  before;  the  vasurmitor  centre  has  Dot  bran  initirfcrod 
witb.  Dliwetljr.  bowevor.  in  proi-oedine  dovrii<van).  th«  n^ion  of  lh«  cwntn 
fo  qutMlon  u  FMched.  itimiiliilirin  (t(  tho  ecialii'  ;ir<)diic«8  \tea  and  Uv»  rise, 
untt]  at  Ian  wh«M  lli«  lower  limit  of  the  centn?  ie  arrives)  at  no  cDVcl  ut  nil 
oa  blood-prcMu  ri'  iiin  be  pTodiiced  by  e7«ii  atrong  BtiiuulaliLiri  of  the  m'iiittc 
or  othvr  atTereDt  nerve.  In  ibia  way  the  lover  limit  i>f  the  medullary  vnw- 
BM>i"r  centra  liaa  been  determined  in  ibe  rabbit  at  a  liorizonlat  line  drawn 
■bout  4  or  3  ntm.  above  tite  point  of  the  calamus  seriplorious.  and  Ihe  upper 
limit  at  about  4  mm.  htxher  up — ■'.  e.,  about  I  or  *2  mm.  below  the  corpora 

JaadriMinina.     When  tranavene  «ectioiid  of  (he  brain  are  carried  Eucoea- 
irelr  lower  and  lower  down,  an  efRwt  on  blood-prewurein  the  way  of  lowering 
it  mmI  abo  of  dimiimbin^  the  riai!  of  blood-preeaure  n«ulliii|{  from  Alimula- 
lioa  of  Ibe  Miauc.  i*  &nt  otiscrveil  wlii^ii  the  u)iF>^r  limit  in  readied.    On 
tmrtyitig  tbe  aectionH  ittill  lower,  the-  effect  of  utimu luting  lb<j!  idatic  be- 
CDOW  Im>  and  Um.  until  when  the  lower  limit  ii  readied  do  edectd  are  at 
■II  obwTTvd.    The  mntre  a[i|H-an  lo  tie  hiliitLTal,  the  halve*  bcin^  placeil  not 
in  th*  middle  liite  but  morv  nidcwayn  nnd  rather  ni-an>r  tin-  anterior  than  tike 
poMeiior  ■urfao''.     U  mav  [lerhnp*  lif-  mure  eliwly  dciiinfl  iw  a  xmnll  pria- 
matir  ii[uuv  In  the  forward  pmlongniion  of  the  Inlrml  coliiniuK  atler  they 
haw  civi-n  »|1'  ihvir  fibre*  to  the  dccumttiii^  iivriimt>l.«.    Tlii*  Hpiice  in  largicly 
otntiMd  bv  ■  mnn  of  gray  matter,  rnired   by  <^'inrke  ihe  nniem-hiternl 
WmJmi.  ami  oontaiain^  lareo  mtit(tt"ilur  cell*  :  but  il  in  by  no  iiicaiii  certain 
tkai  tbia  Kmup  of  nerve  cell*  rc«lly  net*  nii  the  centre  in  ipics^ion. 

)[  1T7.  Tbe  above  es|kerimeiits  appear  to  afliird  udcmiate  evidence  that,  in 

amrmal  ntaie  of  ibe  bodv,  the  iute»rily  of  the  medullary  vasomotor  centre 

iiiweiiliil  to  tbe  imMludlon  and  difttribulion  of  thiwe  continued  oinatriclor 

(■polMa  hy  which  the  ^oeral  anerial  tone  of  the  body  is  inainlaJDcd,  and 

tlal  aa  iunraue  or  d&t-reutfc  of  vom- const rictor  action  in  particular  urleriee, 

orlnihe  arteriea  (cenerally,  in  hnm^bt  about  by  means  of  the  name  m&lullary 

nHuiMor  centre.     But  we  rauM  not,  therefore,  conclude  that  thi.t  xnuill  |Mr- 

iniof  Ihe  metlulla  nbliiDgala  u  the  only  iiart  of  the  central  nervoun  ^yitem 

*Ucfc  can  act  aa  a  i-euire  for  vn.-w>  conittrictor  tlbnat ;  and,  aa  we  have  Men, 

tkm  II  no  erideiioc  at  pr(»enl  that  the  va^i^dilator  fibre*  arc  connecteid 

eilfc  eitlier  ihin  or  any  oth<-r  one  centre-     In  the  frog  reflex  vnaoQiOloredecta 

■ir  be  olitain>-il    by  xlimulnting  variouii  atlfir(rnl    nerve*  alter  the  whole 

■Mlolla  hiiii  lH-i>n  reiniiveil,  iind,  iiideiil.  even  when  (inl^  a  ivim[ianitively 

Miall  portion  of  Ihe  uniiml  cor<l  hiu  been  ]i:t\  intact  and  connocleil,  ou  the 

Mr  band,  with  tite  nnerent  nerve  which  i»  being  (timuliiuil.  and,  on  ifae 

(thar,  with  the  efltreni  nerveit  in  which  run  (he  viL'«>m'>inr  tiliren  whom  action 

a  beinir  »tuHie><l.     In  the  mammal  such  clil<-ct>i  di>  not  «i  readily  appear,  hnt 

My  with  care  nod  under  s|>ecial  conditions  be  obtained-     Thiu  in  the  dog. 

*^n  (he  »pinal  cord  is  divided  in  the  doraal  region,  the  arteries  of  the  bind 

&■!«  and  binder  part  of  the  body,  as  we  hare  already  eaid,  $  172.  beoonte 

dilated,    llib  one  would  naturally  eipect  as  the  reanltof  their  severance 

frnn  tbe  medullary  vaaomolor  centre.     Uul  if  the  animal  be  kept  in  Rood 

nadhion  for  aome  time,  a  nornitil  or  nearly  normal  arterial  (one  is  after  a 

vhiU  recvtablbbed :  and  the  tone  thus  re^nined  may.  by  atTerent  iiapubeo 

narhing  lite  c«rd  l>el<>w  the  aection.  be  moililiexl  in  the  direction  certainly 

•f  itiniinolioii — i  e.,  dilation,  and  noasibly.  but  ibis  is  by  no  meanit  at>  certain. 

of  IneraaaH — i.  r.,  const riciinu ;  dilation  of  various  cutaueou  vcttieU  of  the 


282 


TUK    VA8CCI.AR    HECOAXISM. 


limbs  may  be  readily  [irMluced  by  atimululioii  of  the  oeutnil  Mtimp  of  one  it 
aootber  nerve. 

'Th^ia  remarkable  resuliji,  nliich  tli'm){!i  (hey  are  im*t  stHkioK  i"  euattec- 
lioD  with  ilic  lawvT  |ian  of  ilic  »|iiiiii1  cunl.  hold  ^Mjd  a|)pHi'eiilly  for  other 
perlii  also  urilu;  ^|iiiial  ri>ril,  niiltirutly  »ii]|f);i^l  a  ilinibt.  iv'iirlbfr  the  ex[ilumi- 
ti>>ii  juxt  gtvi-ii  aliiivo  iif  llif  rtTi.Tlii  !•(  scsrliiin  of  the  inHlntla  nhtoiigata  b  a 
vflliil  Olio.  Wbi-.ii  w(,'  citmt^  IQ  «l<iciy  ilii;!  centnd  uitvouh  nystrm,  we  nhall 
again  aod  iipiin  ^t-p  ihnl  thp  tiiiiiicilintf  uHect  of  opcrativu  iiiUrrfercDW  wilb 
lh«o  dolic'jilc  i-lnicturoi  in  ii  Ivrnjiuniry  iiiii>|>cnKion  of  nvnrly  nil  iWir  fun» 
tions.  Thii^  is  oflcn  npokcii  of  ns  "«ho<-k"  niid  mnv  be  r<^irdi.il  »■  ao 
cximnii;  ibrm  of  inhibilioti.  An  rxnmiitc  of  it.  u<>4:iin>  in  the  nbow  «x|>eri- 
mcni  of  section  of  the  dui-Kil  curd.  For  eonie  timo  nlt«r  Uie  operation  the 
Tnso-dil&tor  nerri  erigcnipa  ( which,  as  far  a«  wc  ktion-,  havp  no  speciBl  ooamo- 
tion  nith  the  medullary  vaeuiiioior  centre)  cannol  be  thrown  into  m-liritris 
part  of  a  reflex  action  ;  their  centre  rcmnins  for  trnne  lime  inncliTi?.  Aftor 
It  while,  however,  it  recovers,  and  erection  of  llic  pent!  through  tlw  nervi 
erigentee  may  then  §lill  l>e  brought  abont  by  suitable  stimulation  of  ernsory 
surfaces.  llen<«  ihe  (|uealion  may  fairly  be  put  whether  the  etiects  of  caV- 
tini;  and  injuring  ihe  structures  which  we  have  spoken  of  ad  the  medullary 
vasomotor  centre,  at*  not  in  reality  aimply  those  of  ahoek.  whether  the  va»- 
cular  dilation  which  fullows  upon  pactions  of  the  so-ealleil  medullary  vaso- 
motor eenire,  iti.eM  not  come  about  because  section  of  or  injury  lo  this  region 
exerciser  a  Uron^  inhibitory  inlluencenn  all  ihe  va.ii<ino(or  centra  attuAted 
in  [be  Apiual  rsird  below.  Owing  tn  the  :^pmal  function  of  the  me'lulla 
oblongata  in  carryluj;  >m  the  all  )nipi>rtant  work  <>(  migration,  a  roatnmal 
whnse  medulla  ban  been  divideil  ninnoi  be  kept  alive  for  any  letigrb  of  time. 
We  cannot,  therefore,  put  the  matter  lo  the  Minple  ('X|>eri mental  lent  of  vslir- 
patiug  the  eupportd  medullary  vniwmoUir  i^ientiv  and  nx-in^;  wlint  hiip^-iis 
wbi-n  tim  animal  has  completely  recovered  from  iho  etfrcts  of  the  D|wnilion  ; 
KC  have  to  be  guided  in  our  decision  by  more  or  kt*  indirect  nrgnnient«. 
AihI  against  thti  argument  that  the  effects  are  those  of  shock,  we  nwy  put 
the  nrgunicnt.  evidence  for  which  ive  'hall  meet  with  in  denting  with  the 
CCDlral  nervous  system,  that  when  one  part  of  the  central  nervous  system  ia 
ivinoved  or  in  any  way  placed  hort  dr  cr/mbul,  another  juirl  imiy  ricarionsly 
lake  nn  its  function ;  in  the  absence  of  the  medullary  vasomotor  centre,  its 
fimction  may  be  pcrfirnied  by  other  parts  of  the  spinal  ooni  which  in  iu 
presence  do  no  sucli  work. 

And  we  may.  in  coiuieetion  wilb  this,  call  attention  to  the  fact  that  tlie 
dilation  or  loss  of  tone  which  follows  upon  section  of  the  cervical  avnipatheile 
(and  the  same  is  true  of  the  abdominal  sptanclinic)  is  not  alw«yt>,  though  it 
may  be  sometinies,  perinuuent :  in  a  certain  number  of  caaea  it  ha.'i  I>r«-n 
found  lliat  al\er  a  while,  it  mar  not  he  until  after  neveral  days,  the  dilation 
disappears  and  (he  atteriiv  regain  their  uMial  calibre;  on  the  other  liami,  in 
sooK-  cases  no  such  retani  has  been  obwrved  aflrr  monllm  or  e\'eu  yuam. 
This  rei-overy.  when  it  ix'curs,  cuniiot  nlunyji  be  attributed  to  any  regenera- 
tion of  vasomotor  IJIire*  in  thn  nvmputlK-tic,  for  it  i*  slated  to'bavv  bm-ii 
observed  when  the  whole  length  i>I  the  nerve  including  the  Mijienor  cervinil 
sanglion  had  been  removcit.  When  rccorery  of  tone  ha"  thus  taken  place, 
dilation  or  inereuM'd  couMriction  may  lie  occiisioncil  by  local  ircatnient;  the 
ear  may  be  ninik-  to  blush  or  palo  by  tlic  application  of  heat  or  cold,  by 
gentle  stroking  or  ntu&h  handling  and  the  Mice ;  but  neither  the  one  nor  the 
Other  condition  citn  be  brought  about  by  the  intervention  of  tltc  central 
oervoUM  system.  S.>  aluy  the  spontaneous  rhythmic  variations  in  the  ndibre 
of  the  ailerie^  of  the  ear  of  which  we  spoke,  though  tbey  cciise  for  a  time 
afler  diviaionof  the  cervical  syoipathctic,  may  in  some  cose*  eventually  reaji- 


VAfiOUOTOR   ACTlOXit. 


288 


|<ra  r  «Btl  tliat  evt  u  if  (lie  superior  eorvicnt  eo'ifllion  ^«  retoovin] ;  in  otlwr 

raw*  Ibrj-  ilo  uoi.    Aixl  t]ie  aiimlogous  rtirinnnc  varialions  of  ihc  vdn»  uf 

ibr  l«t'»  winii  liave  htta  proveil  es|wHmeiilally  (o  gu  on  vigoroiiBly  nben 

all  rMUMflivD  willi  the  <«ulnil  nervviia  ivstcm  lius  l>eeu  severed;  thi'V  mnjr 

«(MliBa«.  in  f*a,  iu  iwiUte^l  |>i«ces  of  the  u  ing  |)n)videi)  that  rhe  vimcIk  nre 

«iIr<)(MitrIr  filleil  aiti]  ilUtciiJt-il  with  UIcimI  or  iluiil.     From  llicse  nml  I'lher 

(bi1»,  rvcu  afttr  iiiakiux  allimumx'  for  thi?  mifative  casee,  we  may  coiifliiilu 

that  what  we  have  (poken  of  as  llif  (one  of  the  vei*«lB  of  ihe  face,  though 

influeticwil  hv  am)  in  a  ni«aMire  ilcjHMidoHt  uii  (he  t^entnil  iiervoiii  syetciii.  i» 

ant  aimplj  l^e  r««ult  of  no  c-irirl  uf  that  KyMi-in.     Hie  inusciilar  unlla  of 

Uh*  art«ric>  art  uot  mtn  ]wiviv<-  iiirtruinriiu  wnrkcil  hv  the  (vulral  ncrvoiiB 

ajMcui  through  the  vn^oiiiolrr  fihri-3<i  liivy  app-ar  l<i  finve  an  ininueic  lone 

oTtbclr  Qwu,  BDil  it  ocrmit  natural  to  (U[i|>i^w  llial  nhrii  the  t'etitral  nervous 

■fMcm  caom  ililation  or  con^lririion  of  the  vi-n>cl»  of  thv  facr,  il  rijakea  use, 

ia  wi  ili>i»K,  nf  thu  inlrianic  h>ral  tone.     It  ba*  h?«ti  »iip{i(iii(^d  that  this 

iatniisic  li>t>«  ia  <k'|>eii<li-iit  on  vomer  htcal  iivrvou«  iiiechiini»iii ;  in  (lie  ear  at 

kaai  no  luch  mocDaiiiani  has  yet  been  found  ;  and,  indeed,  as  wc  bavc  said 

aboT*,  I  167,  DO  nidi  |>«'nphenil  nervoiift  niechani«ni  i»  really  neceMary.    In 

Um  cbm  botli  nf  a  vMael  govcroeil  hy  vaso-dilnlor  fibrea  ami  one  giiremed 

bj  TBM^oMtricIor  fibtti,  we  may  suppose  a  ccrlain  natural  enmliitou  uf  llie 

maactibr  Kltrc«  wbieh  w«  mar  i-all  a  condiiion  of  equitibrium.     In  a  vetsel 

(ovencil  only  by  vasodilatbr  libres,  if  there  \w  Hich.  thi«    onditiun  of 

c^DJbrium  ia  ibo  {wrmancnt  condilion  uf  the  niuseular  libre.  from  uliieh  it 

bifiMurbwl  bjr  va»«i-dilalor  impulse*,  but  to  nhicb  it  i<|ieedily  rclurns.     [n 

tnael  govenH-d  by  vaao-mnAtriclur  fibres,  and  subject  u>  tone,  lh«  niuncular 

Bbf«  a  habituallv  iv\>t  on  the  eciiHtrJcior  t'iile  uf  this  eijuilibriuin,  ami,  an  iu 

1        iW  raar*  iiuoteii  ahuve.  may  strive  uf  itself  IuwhkI  (ame  amount  of  active 

L       (Mitrkltuu  even  when  xparati-d  fmm  the  ci-nlrttl  nervous  syatem. 

H       Dm  Io  retura  tu  ibe  rui-dullury  vaariniotor  wntre.     Wiliiout  atteniplin); 

V    tDdiKUas  the  loatler  fullv.  wu  mnv  wy  L)iat,  afler  all  due  weight  haf  been 

aUsrliei)  to  the  play  «f  in^iibitory  inipulnw  nr  "  aluK-k  "  a«  a  result  of  opern- 

i"*  iDterfervnctr,  tlierc  alill  n'niain*  n  balane«  uf  cviiUiu-e  in  favor  of  ibe 

nnr  that  tbc  tvtnun  of  tbc  medulla  uf  whioh  ne  arv  K|Kuiking  does  really 

■rtM  a  f^nvml  vaaomiitur  o-nlrr  in  the  manner  prevtouiilv  explained,  awl 


{■knan  imrairtaiit  pari  in  the  vnoimulnr  r^'ulalion  of  iht)  living  Ixidy. 

Ili*  Dot,  Wvitvcr.  to  be  r<')(arded  a>  the  MUfjU*  vawmiolnr  crnire,  uhenoe 
•hoe  can  i'Piue  (onicoiiutri'-tor  tm|>iiU(-«  or  whither  aHcrt^>t  inipiiUes  from 


*ll  parts  of  the  laxly  mu»l  alwny*  irwvt-l  hcforo  ihey  am  atlwi  the  vaso- 
•**  UupulM-o  |>«oi>iRg  along  thL»  or  that  nen-c.  We  are  rather  to  wuppoee 
>W  lfa»  fpinal  iHinl  alung  il«  vrhojc  length  roulains,  interlaced  with  ihe 
itiaaiMl  lAht-r  mechnnivRH  by  nhicb  the  skeletal  iuii<'(.-les  arv  Kuvemed, 
nmmotor  eeniren  ami  mecbaaisma  of  varied  eomplexity,  the  <lot«ils  of 
■biat  funetioiw  and  lo{>o|^pliy  have  yci  larj^ely  to  he  worked  uul;  and 
■kougli.  aa  mr  have  m«u,  the  medullary  {vnlre  is  essentially  a  centre  of  iui- 
pdtta  bmioi;  nhmg  vnso'«oi)sl  rietor  librea,  it  ia  [Ktssible  that  there  arv  tiea 
BMarrn  ii  and  va^i-ilitatiir  Kbm  also.  Aa  in  tl>e  itbsenoe  of  the  «inus 
■Wmus,  the  auridcs  and  ventricle  of  the  frofc's  heart  may  still  conliniie  to 
•MiMt  in  the  altsenL'e  of  (he  nie<Iulla  obloutcata  thcM  spinal  vasomotor 
noim  provide  for  the  vascular  emerjieiuiea  which  ari»e.  As,  however,  ill 
tW  onrmal  entire  fru^'u  heart,  tlie  sinus,  m  to  sjieak,  ^ivea  tbc  aord  aiwl 
l^nms  the  work  of  the  whole  orjcua,  tti  the  meilullari-  vasomotor  rent  re 
rilcB  ai>d  corirdinaUa  the  I«mmt  centres  of  the  eord,  and  ihronich  them  i>tv 
adt*  over  the  chief  vaacnhir  ureas  of  tJie  body.  By  nieanii  of  these  vbm- 
■Mor  c«^iiral  meehnnisnin.  by  meau*  of  the  head  centre  in  the  mctlulla,  iind 
Ik  auUidiar}-  ceuimin  the  spinal  conl,  tlw  delicate  machinery  of  the  cimi- 


284 


TlIK    vasculab    UECITANISH. 


lation  nhich  dotcrmiues  tlic  blood-etipiily,  and  tm  the  activity  of  eHcli  tiMiie 
auil  or^an,  in  ubie  lo  nxpoiid  by  nnrritwiii;;  or  wiilenio;;  iirlcne«  i<.>  th»  erer- 
vttryiog  iJenutDils  e.nd  to  meet  by  vonipeontiiiK  cliaof^  tite  sliocltB  siid 
Mraina  of  daily  life. 

^176.  W«  niuy  sum  lift  tbe  hift»>ry  of  va»om»lor  Holioiu  turaewbal  as 
follows; 

All,  i>r  nearly  ull,  or  aa  far  as  we  know,  all  the  nrteriea  of  (he  bnily  are 
coniieiTlMJ  witK  t.bc  coatrnl  nervous  sv^tiem  by  tiervc  Abrai,  called  vuo- 
motor  Cihrti,  Uie  iictioa  nf  wliich  vurieti  tlie  nmimnt  of  coutradluii  of  (h« 
niuiteuliir  coiit^  of  thti  srhiric^.  iiri'l  no  leml*  t>]  chuugM  iu  calihrv.  The 
acli'iu  of  these  ragomotor  tihres  is  more  maQit<M  aad  prolmhiy  inotw 
impurlant  iu  the  oue  of  smaU  imd  miiiuie  artcrin  than  In  iho  com  o( 
Inrgnr  ones. 

Thwo  vasomotor  fibres  an-  nf  tvro  kiiirln:  \hr  one  kind,  vago-vonftrictor 
filirif^.  arc  of  such  n  niiliir?  or  hnviMHich  connectiiinH  nt  thdr  central  origin 
or  pcriplirml  ending  tbiit  sliiiiiilation  of  (lu-m  produces  nnrrowin);  con- 
etnctinii  of  rhv  nrt<Ti<^ ;  and  •Itirioj;  lilb  llipec  Hbrcs  Bpp«Kr  to  bo  the  ■□««»« 
by  which  the  cpninil  ncrvoii*  »y«icm  pxcriB  a  cunlinued  tonic  inHiipnec  on 
thr  nrtcri<«  iinil  mninUiinK  an  arC^irial  "tone."  The  other  kind,  ihc  vato- 
dilator  librn.  arc  of  HUch  a  kind  or  have  such  conneclions  that  Mimitlalion 
of  tltcni  priidiica'  widoniiic.  dilntion  of  the  arteries.  Tliere  is  no  adet)uate 
evidsDOe  that  these  vaso-dilalor  fibres  serves  as  chaonelfi  for  tonic  dilating 
tDOpulMe  or  influences. 

The  va£o-coii!ilriclor  Hbres  leave  tbe  spinal  c«>rd  by  the  anterior  rooU  of 
the  nerves  eomint;  from  middle  re^ioua  of  ihe  spinal  eord  only  (in  ihe  doj(. 
and  probably  in  other  mammals,  thim  about  the  aet.<ond  dorul  to  the  aecooa 
lumbar  nerve).  pasH  into  the  ^plauchnit-  ;^uf;lia  connected  with  tliooe  nervea 
(tlmracic  and  ahdoniiual  chain  of  ayuijiatlietic  ganglia),  whera  the  libres  loee 
tfai^ir  medulla,  and  procec<l  lo  llieir  deKtimilion  im  non-mi'diilbilcil  fibre*, 
cither  Htill  in  mi-cullcil  nympulhi-tii;  nerve*,  such  iw  ■plaochnic.  cervical  •ym- 
patlietic,  liy|>ogaiiCric,  Ho.,  or  along  recnrrrnt  lininclitv  of  the  splanchnic 
SjBtciD,  to  join  tlir  »pimil  niTvcn  of  the  arm.  W.  nnd  Innik. 

In  the  inta«a  orvnnii'm  Ihr  emiwion  and  diMtriliiition  along  thi.-«e  vaM- 
(wnslrictor  l>brw  of  toiiioconrtriirtor  impulses,  by  which  general  and  loca] 
arterial  tone  is  inninUiincd  and  rcgnlalrd,  is  governed  by  a  limited  ponion 
of  the  mcdidia  <ibl<itigal»  known  as  the  mcidnlliiry  vasuniolor  centre ;  and 
when  «)nie  i-hnti);e  of  con<lilionE  or  olh«r  natural  stimulus  brings  about  a 
change  in  the  activity  nf  iIki  vaso'cansirictor  libres  of  one  or  more  vaacular 
areaa,  or  of  all  the  arteries  siip|ilied  with  vaso-cuiistriclor  fibres,  tltis  same 
nwilullary  vasomotor  t:enire  uiij^ars  In  such  eas«t  to  play  the  part  of  a 
centre  of  reflex  action.  NeverlneleM,  in  caaea  where  tbe  nervous  ooniMelionk 
nf  ihiH  medullary  vasomotor  centre  with  a  vascular  area  are  cut  off  br  an 
operation,  as  by  action  nf  the  <.-()rd,  other  parts  of  the  spinal  eonl  may  act 
as  centres  for  the  vaao-ronalrictor  tibruti  of  Uie  area,  and  puMibly  tbvac  sub- 
ordinate centre*  may  be  lo  a  certain  t-xteiil  in  action  in  the  intact  organism. 

Tbe  vaiffdijator  fibres  apfiear  to  taki?  origin  in  vnriou.i  puria  of  the  central 
iKrvtMis  iiyNtem  nnd  to  proceeil  in  a  direct  niunte  («  their  destination  along 
the  (anterior)  roolnand  ai  juirt  of  the  trunk*  and  brancbitfior  varinuM  cprebro- 
•pinul  nerves;  tliey  do  nut  hm-  their  medulla  until  tlicy  nppniach  thoir 
terniinalion.  Thry  do  not  nppcnr  lo  sorro  as  channel*  of  tonic  dilating 
toflu«nc«s;  they  are  thrown  into  nction  generally  as  part  of  a  rvflex  action. 
Mid  their  oonire  in  the  rdh-ic  ncl  appciir*  in  «ach  case  to  He  in  th<-  e«nlral 
nerroiu  eystem  not  fur  fimm  the  centre  of  tbe  ordinary  motor  fibres  which 
titer  accomi>any. 

'f  he  ellectd  of  the  activity  of  the  vaaMlihOor  tibm  apjwar  to  be  essentially 


VASOMOTOR    ACTIONS. 


285 


I 


i 


lormt  iu  nature;  wbrn  any  set  of  ilivni  coroe  iiilo  actiou  llie  ruscular  iirva 
«kirh  tbrw  lEOTtiii  i«  dilnred.  Ami  the  vavniliir  «Te«i  w>  governeil  are 
rrUiivvly  to  Btnill  ilmi  rlinn^vs  in  tli«tii  jirinlure  liiile  or  no  effect  on  the 
TitcwUr  natMti  io  general. 

'llivrfr«clii  iif  rbuDM  in  ili«  Kdiritynf  ihevii»i>rAti*trict»r  libira  arc  botb 
toctl  and  fti-timil.  iidiI  iiiiit  tto  nlM>  doulile  in  naliiti'.  By  mi  inhibilioii  of 
ttDic-t^iinlrirtiT  im|iulH-ii  i>  txTCHiii  iiouiimt  of  itiliilim)  loxy  \ir  cflwtrd  :  by 
n  tOfEiM-DtiiUon  of  coiwiririor  ini|iiili»«.  CHiiftrii-lton,  it  ninr  Ik-  of  miwiikr- 
■bircxtmi.  may  Iw  bmu^lit  about.  Wlmti  the  viuK-ulitr  arL-n  w>  iiHrclr^  it 
oiiiU,  Uia  eflccia  arc  local,  mom  or  Ick<  blnotl  i>  itirlrihulrd  llin>iigb  ib^-  una  ; 
•btatlM  raMmUrarcn  nHcdnl  !«  large,  thv  inbitiitiim  of  conHrictioii  nmy 
bad  la  a  marknl  fnll,  mid  an  augiDentalion  of  consirictiun  tn  a  marked  tim 
tt  rmtral  blood-urtnure. 

{1T9,  Wc  ahall  liavs  occatinn  lalcr  on  ngiiiii  Uld  oniin  to  point  out 
bWucn  of  lliB  tStvtf  of  vaMmutor  action,  both  local  an<i  ecnemi.  but  wc 
•a;  hen  tvavXt  vov  nr  t«o  rbamdcrimic  nnn.  "  Itliiabing  '  i«  on«.  Ncr- 
1M«  iaipu[*n  starird  in  khic  {lan*  of  ihc  brail)  l>v  an  cinolion  [irodiii-o  a 
(■arrftil  inhibiliikn  of  that  )iart  of  ibc  niE'dullary  vasumotor  centre  nhich 
funtni*  thv  viiKiilnr  areas  of  the  head  supplied  bribe  cervical  sympalbr-iic, 
•arf  btncT  hji»  on  elTcct  on  ibe  vaeoniotor  tibrea  of  tbe  cervicnl  sym pathetic 
■InatMlOliy  tbe  rn»>v  n»  ibat  produceii  liv  MctiuD  of  ibe  nerve.  In  mnse- 
^omnilM  niiiiH!ul»r  wall»  of  tbe  arleriea  of  tbe  heud  and  face  relax,  the 
ttirrir*  dilalr,  and  the  Khiile  region  beconiea  iulluBed.  Kuiuetiniea  an  eino- 
u»ii  ^ivra  rise  not  In  blu»biug.  but  to  ihe  oppotite  elfecl,  vix.,  to  juillor. 
In  a  Kn-ai  number  of  ea»«t  tbift  biin  <pitte  it  i^tTereni  CAiiae,  being  due  to  a 
Mililea  diminnlion  or  even  tein|H>rarv  urrenl  uf  the  heart'*  beam:  bnt  In 
MM  oMo  it  Riaj  (K-ciir  without  any  elinngc  in  ihe  bent  of  ibe  liearl,  and  ia 
iImi  due  to  a  raiulilion  the  very  convcme  of  that  of  blmhiitg,  ilint  i*.  lo  an 
iMmwd  arlrrial  miiatrietion ;  and  this  incmscd  coofiridion.  like  tbe  dila- 
■in  nf  bluahiog,  i«  eflretcd  through  the  agency  of  tbe  central  iierTousaysieia 
ut  the  eerviou  ^mpathetic. 

The  vaanitar  ci>udiiion  of  tlu  «kin  at  larg«  aflbnb  another  insianco. 
Vh«D  Ibe  teniperaiure  of  tb«  air  is  low  the  vraeels  of  tbe  skin  are  eon- 
•cHrifd  and  the  »kin  is  pale;  nhen  ibe  teinperulur«  of  tbe  nir  is  bigh  tbe 
T^Mb  of  the  ikin  ure  ddaied  and  ibe  xkin  is  re<i  and  tlurbed.  In  both 
Ikne  raM-«  tlie  eHirci  is  mainly  a  reHex  one,  it  being  the  central  nervous 
iTtfrm  whieh  brings  about  augiueniatiou  of  coDelrictiun  in  the  one  cttue  and 
(iUbillon  in  tbe  other,  tbotigh  possibly  some  alight  elfet'l  is  reprociuced  by 
ibt  dirtet  adton  of  the  colli  or  heat  on  ibe  voaels  of  the  »kin  dimply.  More- 
erer,  lb«  vucalar  ehangm  in  the  fkin  are  aceompvinied  by  corn?ii(K>ndi»g 
nacnlar  ehanges  in  the  vnsoera  <  ehieHy  abduminal)  of  u  revorae  kind.  When 
die  rwtia  of  the  skin  are  dilnTtnl  tbuve  uf  ibt!  viwecrv  ar«  con«lnc<ed.  iind 
iwe  arrait,  so  that  a  eonsiderablt!  jiorlion  of  the  whole  blund  ebb*  and  (Iour, 
» (o  speak,  aeronline  to  circuuitiliinci^  from  akin  l»  viHoi-ra  and  fnim  viscera 
Mikln.  By  ibeae  cnutgea,  an  we  nhnll  see  later  on.  thi:  nmiutonance  of  ibe 
■anaud  tenil>eralure  of  Hie  Wly  i«  in  large  metmiirc  fet-untl. 

Wben  food  >a  |>laeeil  in  the  mouib  ibe  TdondvwMdN  of  tbe  aalivary  glaniK 
■a  we  have  tee».  are  fluibird  itilh  bluml  an  an  adjuvnnt  In  llic  fccretion  of 
4iKt*ttTe  fluid:  and  ns  Ibc  IWl  panm  along  the  alimentary  canal,  each 
■aeiian  in  turn,  Milb  the  glandular  apix-ndiigiii  Ix-lnnging  to  it,  wclotiineii  iu 
Mltent  bv  tlusbing  with  hloixl.  the  tlilniion  U-in^  souielimea,  lu  in  thu  COM 
u(  the  aaliTary  gland,  ibe  rcxtilt  of  Uii'  aetivity  chiefly  of  vneodtlator  fibres, 
bataonrliniea  the  rntult  of  the  oeniniton  of  constrictor  imimUes  and  tone- 
iban  tbe  mtill  of  lb<^  two  oiinbin<-<].  .So  also  when  the  kidney  eccretts 
wfiw.  ilamwls  bemme  dilated,  and  in  general,  wherever  fiin<-lii>nal  activily 


see 


THE    VASCCtAH    MECHAirrSX. 


oomn  iota  (iliir.  the  iii(!tu1)»!Uni  nf  liiuiic  vrliic')i  in  tlii^  liiuin  of  that  nclivUy 
is  AMiMMl  liy  n  more  geiit-'routi  tluw  i>f  bl<MHl  ttiiviiijili  iho  liiwui-. 

§  180.  rii*r;iii'((ur  itermv  »f  (hf  rein*.  AUlHuiyli  tW  vriiis  itiv  providwi 
vrith  itiiim.-ulnr  tibrc*  itnd  Mre  (IwliiiCtlT  coutnii'tilc,  nixl  nlthough  rhythmic 
rariatiiiti»  of  ciilihn.-  ilue  In  coiitrnctioo*  tauy  Iio  vtxa  ill  the  f^rmt  vdat 
oi>ening  iiitci  llic  heart,  in  th(?  voins  of  the  bntV  wing,  nn<l  elaevrhera,  aod 
tiiuiilnr  rhythmic  viirintiou*.  nl«j  poeniblv  tlu«  to  avtivo  rhyltiniiv  ooninu;- 
timid,  hill  powhly  ttlitif  of  nn  iinlircly  pm^ivc  niitiiro,  hnve  been  obeerved  in 
ihv  portal  vein*,  verv  littli;  is  kiiuwii  of  nny  nr rvous  arrangemeoU  gorcm- 
iiig  the  vein*:.  When  in  the  frog  iho  lirniii  and  epinHl  corH  are  deetruvet). 
very  little  blo'id  comes  back  li>  the  heart  us  compared  with  the  norninl 
rii|i[]|y,  and  the  heart  in  conacr[ue[ice  appears  almnel  bluodle^  auil  heats 
fcehly.  This  iia;  been,  by  some,  re^'ardoti  as  more  than  can  be  accounlfil  for 
by  mere  loss  of  arterial  tone,  ami  arcurdinh'lv  interprelcil  as  indicatJn)!  the 
esiitieuoe  of  a  normal  lone  in  the  veins  de|>eQileiit  un  the  ceiilrvl  ncrviw* 
syMem.  Whoii  the  Utl«r  is  desiruyed,  the  veins  become  abnormally  dtMcnd 
and  a  tnrj^e  (luantity  of  blood  become  lodged  and  hidden  oa  it  were  in  ihen. 


TUR  CAPII.LAltT   CiRCULATIOll. 

|S  181.  We  have  already  some  t^mc  back  (§  117 1  meolioneil  amue  nf  ih« 
tulieut  leatiircs  of  llie  circulation  throU{>h  the  capillariea,  viz.,  the  ditGctilt 

Iiawage  of  the  corpuscUe  (generally  in  single  tile,  though  someliiii&'  in  the 
nrger  ehanneli  two  or  more  nbrenst)  and  plasma  thrmigh  the  uarrair  clioti- 
»el«,  in  a  stream  which  though  more  or  lew  irregular  U  titettdy  and  ev«i, 
not  brukeo  by  pulsations,  :ui<l  slower  than  tliat  in  either  the  arteries  or  th« 
veins.  We  have  fuilher  fiei^ii  (^  HXi)  that  the  cjipillarie*  vary  r«ry  much 
in  width  from  lime  tu  time;  luid  there  uiu  be  no  doubt  that  tlie  ehongM  in 
their  enlibre  ai-e  cbielly  of  a  piuuivt-  nature.  They  ni%  oxpandcil  when  a 
hirgc  "iipply  of  lilooil  rein'hpM  them  lhr«iiigh  thp  •upplyiitg  arteries,  and.  by 
virtue  of  their  elniticily,  »hrink  iigain  when  the  supply  is  lessened  or  nilli- 
drawn :  they  may  also  become  expanded  by  nn  ol>staclc  to  the  venoaa 
oultlow. 

On  the  Other  hand,  as  nc  have  also  sialuil,  there  is  a  certain  amount  of 
evidence  that,  in  youn^  ntiiiunli>  at  all  ex'eat».  the  calibre  of  a  capillary 
e«nal  may  vary,  iiuile  indq>en()eutly  of  the  arterial  supply  or  the  vcuouV 
outHow,  in  consojuenoc  of  changw  in  the  form  of  the  epithelioid  eelU,  allieil 
to  llie  changes  which  in  n  mmx-k-fihra  or  muscle-cell  constitute  a  conimc- 
tion  :  and  though  the  mailer  re<iuirea  further  investigation,  it  is  po^ible  that 
tiieoe  active  changes  play  nn  important  part  in  delermining  the  <|uaiitity  of 
blood  parsing  through  a  capillary  area  ;  but  there  is  as  yet  no  Mtiitfaciory 
evidence  that  they,  like  the  corresponding  changes  iu  the  arteriea,  are 
gurernHl  l>y  the  nervous  syBtem, 

Over  and  above  theae  obaages  of  form,  tbe  capillariea  and  niiuule  voacU 
are  subject  to  cbansee  and  exert  in6uences  by  virtue  of  which  ther  piny  an 
important  pari  in  llie  work  of  the  drculation.  Their  condition  >k-terniiur« 
tbe  uni'mnl  of  rejialance  ottered  by  iheir  channels  to  the  flow  of  blofxi 
thronjrh  1 1  lode  channels,  and  deteruiiues  the  amouiii  and  character  of  that 
interohangi!  tx^tween  the  blood  and  the  tiaaues  which  ia  the  main  fact  of  the 
circiilaiioi). 

If  the  web  of  the  frug'a  foot,  or  better  still  if  aotne  tnuuparwnl  ti«siie  of 
a  nuimiiial  Ih;  watched  under  the  micrusicojK.-,  it  will  be  obaervtil  that,  white 
in  the  small  cnpilbriiw  the  corpunohw  arc  prcMi^l  through  the  channel  io 
single  lilc.  imtt  nllcr  the  utiter.  each  corpuMlc  as  it  panes  uocupying  the 


TUB  CAFtLLARY   CIBCI'LATION. 


287 


«h»te  bur«  uf  iIk*  mnillnry.  in  tbo  Inrgpr  capillHrim  fof  the  luatiimali,  aur] 

•ptdally  ill  llif  •iiiBll  (irlmr*  aiwl  \-mbs  nlik-h  permit  the  piUHiee  of  more 

IMB  iiDtr  mrnusolc'  nlirtNut.  the  rvl  corpuicle^  niii   iu  the  miildle  of  (he 

(lBnBi>l.  romiiiig  n  cnlonil  mrv.  tiehtceti  uhioh  and  ihe  Mde^  of  the  vcMeb  nil 

II    alBllwl  u  n  <'<>h>rl<w  layrr.  ru[i(»iiiin^  no  rvii  ^jrpiisclra.  oulkil  t)ie '~  |ilitiiriiatic 

■^^b"  or  "  [M' rip  III- ml  t"ae."     this  divi.qiou  inlo  a  |H-ripheral  tone  aix)  mi 

^^^Blllfmiii  it  ilitc  to  tti«  fact  lliai  in  aoy  atreaiu  pai«iug  tlu'nu;;h  a  rliuetl 

Vrimail  Um  friction  !•  };rcuile«t  nl  ihe  udca,  and  diniioiabe*  liiwani  iIk- axi^. 

VTh*  foqioarla  paM  n  here  tli«  fnclioii  is  least,  in  the  axU.     A  iiiiiu^  ximilnr 

ftiia)  Rin-  is  wen  nbeii  any  liue  parliclev  arc  driven  nilh  a  siitlicient  vvloi-ity 

ia  ■  unMiii  iif  fluid  tbrou(;h  a  narrow  tul)e.     A»  the  veJucity  in  diniiiii*lie(i 

Uie  axial  core  Itecoiuca  kn  marked  and  dixap[M>an(. 

'         In  tbe  peripheral  zone,  (speciallr  in  that  ui'  the  veiitf,  iire  frequently  teva 

'      vbiM  coqN»cl»,  Mmeilinca  cliiigEog  to  tJiu  «idei>  of  ihu  vvnh;).  siinieiinie* 

I      folliMS  »lowly  aJonp,  aiul  iu  general  tnoring  irtcgiilarly. (topping  for  n  wbilc 

■lid  (ben  audilenly  moving  ou.     The  crearor  lli«  vehidly  of  ihe  flow  uf 

Und.  the  fewer  Ihe  white  LifrptiitclcM  ia  th<-  pi?riplier»I  loan,  and  with  a  very 

npid  flow  iJiey,  a>  nell  a»  the  ml  i'i>rpii!tcic«,  inav  lio  all  confinnl  t<>  tb* 

aial  itrHun.     The  pn-m-nw  of  the  whiu-  i-orpiin-lci  in  the  pcripheml  ztino 

hMhrea  attributnl  lu  (li<.'ir  bcinj^  »peeinlly  li;;hler  thnn  the  red  corpusclca. 

met  vben  fine  jMrticlot  of  two  kinil*.  one  lighter  than  the  other,  are  itri\'eii 

ttwwgh  a  iinrn)«t  ttitie.  the  li<-avii.'i'  parliel««  How'iii  the  axis  and  the  lighter 

bifc*  tDure  peripheral  |H>riioiiii  of  tlie  stream.     Btit.  besides  this,  the  white 

MnHMck*  have  n  greater  teti<lcn(-y  to  adhere  to  surfaces  thao  have  the  red, 

~~  M  mn  by  the  manner  in  which  the  former  become  fixed  to  the  ^l''^ 

and  cover  »lip  when  a  dr~>p  of  blood  is  moiiated  for  luieroicopii-al  ex- 

■lioo.     Tbey  probably  thus  adhere  hy  virtue  of  the  amwhoid  move- 

WBtaof  tbdr  protoplasm,  »o  that  the  adn«jiion  is  to  be  ci>n«idereil  h[jI  no 


I  a  nierv  i>byi>ioal  as  a  physio] o)^ical  procrau.  and  hunoe  may  be  expecieil 
■•nnr  irilli  tli«  varying  nucrilivu  (vtndllions  of  the  oorpusclus  and  of  llie 


Uwlruwh.  Thus  irhllc  the  am>i-arani>e  of  tbo  whita'  corpuscle*  in  tliP 
pnipbanO  aoiui  may  be  due  to  their  lighiiKMt,  their  tAinpomry  altnchnienl 
la  tM  iiilai  nf  Ibc  vtwels  Bn<l  ehurnntenslic  progrewion  U  iho  mull  of  their 
p>««r  Co  adhere ;  and  as  we  shiill  preirntly  see  their  amntboid  raovem«Dts 
mn  atrrv  them  on  beyond  men.-  nil(ir»ii)ii. 

f  18t,  TlirM"  are  the  phenomnia  of  tin-  norrnnl  circiilution,  and  may  be 
nganlril  ii^  indicating  n  i^tnle  of  niiiiilibriuni  between  the  blood  on  the  one 
faiail  and  the  blootlvesrf.-le  with  the  li>>«ii<»  on  the  other;  hut  a  diflereat 
Ale  of  things  setx  in  ivheii  that  «iiiiilihriiini  is  overthrown  by  causes  lend- 
Off  In  what  is  railed  inflaniination  or  to  allied  conditions. 

If  an  irritant,  such  as  a  drop  of  chloroform  or  a  little  diluted  oil  of  raus- 
tsnl,  be  a|>pli«ij  to  a  small  portion  of  a  frog'n  web,  loogue,  mewnterv,  or 
■■■  other  tRaiu|<aTvnl  lisaue,  the  folloiring  ebnnges  may  be  observed  under 
the  nlrmseope ;  they  may  sbo  be  seen  to  tbe  nie«enierv  or  other  tmnnpsrent 
liMH  of  a  nuuouiAl.  llie  Arst  eD'ect  that  is  noticed  i^  a  dilation  of  the 
iricrica,  aoennijianied  by  a  r|uiekeuing  of  the  stream.  The  irritant,  probably 
W  a  dirwt  action  on  the  muscuUr  tibrea  of  the  nrleries,  ha*  led  to  it  relaxa- 
Mil  of  ibe  muscular  ettot  and  heuee  U*  a  wid»iiHg;  and  we  have  already, 
I  lift.  eKplaiii«d  how  *ueh  a  widening  i»  a  «inall  iirlery  may  lead  u>  n  teni- 
fnnry  ifuirkening  of  tbe  stream,  lu  coQse>|iieuoe  of  the  greater  flow  thmugli 
lh«  arUrrim,  Ihe  eapillarieri  become  filled  with  corpuscToM,  and  nuiuv  ]hw 
•gWi  pfwiously  invisible  or  nt«rlv  so  on  lu-ciunt  of  their  oiniiiining  no 
'Wpwit*.  n»w  oonie  int'i  view.  The  vein*  at  the  same  time  appear  eu' 
Wftd  Mod  full.  If  the  Nlimnloi  Ih-  vt'ry  slight,  thii  mny  all  [MM  away,  the 
gaining  their  normal  eousuiction,  himI  the  oipillnrint  and  veiiw  re- 


888 


Tnr   TASCOLAIt    MKCTTANISU. 


tuniiutc  tij  l.lidr  normal  I'omlilum :  iti  mhor  wurd-t,  the  eflet-t  oftliu  irtitnul 
Id  such  &  ca»e  it  simply  u  tcni[Hintn-   tilimh.     UoltM,  Iwiwcvn-,  t)i«  chlor 
f«>riii  or  niiutunl  ha  ap»li<'il  willi  tKjM-ciiLl  cnn.'  the  ei&cU  »T0  much  tuort 
proroiiiii],  aiid  a  ^-ricn  nl  rfuiarkublc  cbunjctv  tei»  in. 

In  the  iKinnal  circulntioti.  un  no  hnvv  jurI  mid,  while  oorpuHcIc*  may  bo 
Men  iu  itif  jirnjilieriil,  rihiMnulio  xiim;  but  tbcy  itri^  scaiilv  in  numUtr,  and 
eaob  nno  aflrr  nluyiiif;  for  ■  liltl«  time  in  one  spot  guctdciily  g«ls  ftvc.  «oa>fr 
time*  nimniii  by  n  jerk  n*  ll  were,  mid  ihrn  roll*  on  i'or  a  grealw  or  k«  di»* 
tuncir.  In  Ihc  iirwi  now  under  coneidcmii-in  ii  lurgc  nurabrr  of  while  cor- 
pititclce  doon  gnllii-r  fn  tbc  iMrinlitni!  /ohm,  cupccinlly  of  tbe  veina  and 
vcniiiw  c«pillnric».  (that  is  of  tin-  inrgor  oApiUiirlfi'  which  lire  joining  to  form 
vein),  but  nieo.  to  u  lew  cxlent.  of  th«  nrtcrice;  and  thi«  tnkee  place 
nlthongh  the  vcescia  still  remnin  diluted  nnd  the  streiim  still  coniinues  rapid 
though  not  HO  rnpid  at  at  tirst.  Kach  white  corpuscle  appears  to  exhibit  a 
grenier  tendeoev  to  slick  lo  ihe  sides  of  ihe  vessels,  and  tnough  driren  away 
from  the  arlenes  by  the  Hlron^r  arterial  strenm,  becuiDes  lodged,  so  to 
speak,  in  the  voiiu.  Since  new  white  eorpuades  are  coiiliuually  being 
brought  by  the  blood  atreiim  on  to  ihe  scene,  Ihe  number  of  them  in  tlie 
peripheral  Kouee  of  the  veins  increases  more  and  wore,  and  this  may  go  on 
iiDtil  the  inner  surface  of  the  veins  and  venous  capillaries  appear*  to  be 
lined  with  a  layer  of  while  corpusclefl.  Tbe  Ainall  capillaries  too  ooniain 
more  white  corpuscleti  thiinusual.  and  even  in  the  arteries  these  are  abood- 
aut,  though  uut  forming  the  distinct  layer  seen  in  the  veins.  The  white  eor- 
miscle^.  howi^ver,  are  not  lliv  nuly  IxHiies  present  in  ihe  pertphenil  xoneL 
Though  i»  tbe  oorinal  circulation  blixid-plalvU-l^  (see  ^  3^)  cannot  tie  act-n  id 
tbe  periplieral  none,  and  hence  luust  be  ciinfin<H)  (on  the  view,  which  has  ihc 
greater  support,  that  tbcMC  bt)di<«  arc  really  prcvenl  in  i]uit4>  normal  bliHid) 
to  th«  axial  stream,  tlioy  make  th<>ir  iipp«irnncc  in  that  zone  with  th« 
changes  which  we  are  now  dc«criking.  Indeed,  in  many  cases  Lh«y  are  far 
mon:  ahiindiuil  than  the  while  corpuscles,  tbc  Inllcr  np)icaring  imlwddcil  nt 
intervals  in  ninsees  of  the  former.  8oon  alter  their  appearance  tlie  indi- 
vidual nliiiclcls  lose  their  outline  and  run  together  into  fonntfw  miissos. 

^  183.  This    much,  the  appearance  of  numerous   while   corpuscles   and 

filatelets  in  ihc  |x^ripheral  zones,  may  take  place  while  the  stream,  though 
en  rapid  than  at  the  very  lirst.  still  remains  rapid ;  to  rapid  nt  all  eveiila 
that,  owing  lo  the  increased  width  of  tbe  passages,  in  spile  of  the  obsiructioD 
ofFered  by  the  adherent  while  corpuscles,  the  total  t)UBnlity  of  blood  llowiog 
in  a  given  time  thn^ugh  tbe  indained  area  is  greater  than  normal.  But  soon, 
though  the  veascis  fatill  remain  dilated,  the  etreani  is  observed  most  distinctlj 
to  slacken  and  then  a  remarkable  phenomenon  makes  its  appearance.  Tlie 
white  corpuscles  lying  in  conlacl  wiih  the  walls  of  the  veins  or  of  tbe  capil- 
laries are  seen  to  thrunt  pri)i-e.-o>e«  through  the  walls;  and.  the  process  of  a 
corpuscle  incrwii-iug  at  ihi-  ex|K-iitK-  of  the  rest  of  the  body  of  the  furpu*<,'le, 
the  whole  corjiuriclt^.  hv  what  nppi-urs  to  be  au  example  of  amoeboid  more- 
ment.  inake:^  its  way  ihniugh  thi^  wall  of  the  Te«el  iiilo  the  l^mpli  spue* 
outside ;  the  [wrfomtiun  ap^H-nn  lo  lake  place  cither  in  Uie  oenieul  sulwiance 
Joining  the  epithcl)oi<l  plnt4'i>  ton-ilicr.  or,  pomhly,  by  an  actual  bn-ach 
through  (he  subiitHiiee  »f  a  plnl(^  Inr  bri'iich  being  rcjHiired  immetlintrly  ufivr 
ihc  (xiiiHigc  of  Ihc  enrimsclc.  This  ix  the  migrniion  of  llii;  white  corptiM-lm 
lo  which  we  nlluili'd  in  ^  -12.  nnd  takfs  plnct-  chiefly  in  tht-  vcinn  and  cJipil- 
larim,  nut  at  all  or  lo  a  very  slight  extent  in  the  arl<;ri<-».  Thntttgh  this 
mignition  thi-  lymph  spaces  around  the  TwnU  in  the  intl.imed  art*  bocoffi« 
crowded  with  white  corpuscles.  At  the  nme  time  the  lymph  in  the  samo 
Kpacn  not  only  increases  in  amount  kjit  changes  somewhat  in  its  clietnicnl 
ehanicters ;  it  becomes  more  distinctly  and  readily  coagutable,  and  ts  some- 
times spoken  of  as  "exudation  fluid,"  or  by  the  older  writers  u«"coiigulBbie 


TUK   CAPILLARY    CI  BCL'LATIOCT . 


289 


'D|ih.''  Thit  tur;:«ciccnce  of  llie  Irmpli  spnt'ei',  loc«ttier  witli  ihc  liilaied, 
(n«ikil  cooditiou  of  tbe  blo-idvcteeU,  t:ivo8  rise  U>  the  Bnelling  uhich  m  nuo 
tt  U«  faatora  of  iollaaiiuatioD. 

1/  the  inflKinnialioa  now  ]«mm  oS*  the  wbiu  rorpusoles  onue  to  emigrate. 
Htm  to  ttirk  fur  anj  length  of  time  to  ihe  sides  of  the  veesels.  tke  mkiiiii  or 
bltod  llirtui^b  the  v«aMb  quivkeos  XKaiu.  atul  tbe  veuela  themselves,  tlioiigh 
UicTiDkT  rfmniii  for  m  ioog  time  dilateil,  i>v«ntiially  n-guiit  tbeir  oatibrc,  hikI 
a»iriul  I'troitntion  (•  roiMablithed.  The  niigruled  eurj>iiH'Ii-.H  move  iinnv 
ftMD  tbe  region,  ilon^  ihv  liibyntiih  of  lymph  ipoeea,  and  llie  Hurjilu)  \ympa 
ilu  MM  Rwajr  algni;  the  Irmph  zi\tnitM  uud  lymphatic  veM>)ii. 

i  IM.  The  copilitiun  of  tiling,  however,  instead  uf  |itu«iug  nff  may  go  on 
t»  ■  (iirtber  stage.  Morv  aim  rnvrv  while  ourjniaclux.  arnwk-d  in  thdr 
ftm^  crond  th*-  chaonvis  and  block  the  way,  wi  that  tlioiigh  tht^  vtwels 
ivnain  dilMed  tbe  strmm  b<-eiiniM  flower  niici  «lowcr.  unlit  at  la«t  it  stops 
aJloKtiher  and  "  stn^ation  "  or  "  stasis  "  «el«  in.  The  red  corpusoW  are 
•Irirea  in,  often  in  manee,  among  Ihc  white  corpusclci  and  platelets,  ihe 
(latiiiction  between  axial  Mrcam  and  peripheral  tone  becoming  lost ;  and 
ffUriak  reioe.  and  eapillarie',  all  diatendcd.  «nmetimee  enormously  so.  are 
iDed  will)  a  mnaof  niingW  red  and  while  oorpUBclcs  and  niatelets.  When 
tdul  tto^ation  occars  the  red  eorpuH-les  run  together  so  tlmt  their  outlines 
tr«  no  loaser  diatiBUuiBhable ;  they  api>ear  to  Become  fused  into  a  homo- 
pMMH  red  mass.  And  it  may  now  be  observed  thnt,  not  only  while  cor- 
!■«)(•  but  also  red  eorpusolee  make  ilieir  way  through  the  distended  oiul 
ikfftd  walU  of  thf  cupillari<».  ehielly,  at  all  events,  at  the  junctiona  of  the 
enjtheliaid  plaits,  into  the  lvmj>b  apaces  bevuud.  This  h  spoken  of  as  the 
^malmi*  ia  the  rvt  cori>usGles. 

This  Utt«r  "etagnalion"  stage  of  inftammntioii  may  )>r  tlie  prelude  to 
bftber  niuchief  and  indeo<]  to  the  death  nf  the  inflanie<l  tiiwue,  but  It,  too, 
Eks  the  earlier  stogm,  may  pas*  awny.  As  il  pasKv  away  the  outlines  of  tbe 
iwpuscles  l)ecoino  once  more  difiinct,  thuee  on  the  venous  side  of  the  block 
(rMually  drop  away  into  ih«'  neighboring  currents — little  by  little  the  whole 
doCracUoo  is  removed,  and  the  current  through  ihc  are«  is  reestablished. 

TW  alnwinj;  and  final  arrest  of  the  blood  currcni  described  above  is  not 
^  to  OUT  lessetiini;  of  the  heart '»  beat ;  the  arterial  pulaations.  or  at  least 
Av  ortcrtel  flow,  mav  be  aeen  lo  be  continued  in  full  force  down  to  tbe 
iHrtlii  area,  aud  there  ■»  cease  very  suddenly.  It  is  not  due  to  any  eon> 
tuidioa  of  iIk-  flmnll  arteri<9<  increasing  the  peripheral  rfsialnnw,  for  lh«se 
eminiK  dilated,  nomuiimt^  eievedlngly  so.  It  must,  thervforc.  he  due  lo 
«■!•  now  and  unusual  miMoncfl  occurring  in  the  area  il*clf,  and  there  caD 
Wnodoubl  thatthi*  iKlobefonnd  in  an  increased  Icmk-ncv  of  the eorpiisclve. 
apoeially  of  the  white  corpuscle*,  to  Mick  to  the  tiidui  nl'  the  resMls.  The 
(ecifsa  of  adhenivciiiw  is  not  cauited  by  any  (Jiange  conHnud  to  the  corpus- 
riM  t&etnseUes ;  for  if,  after  a  tcmnorarv  delay,  one  set  of  oorpusclee  bos 
■aaoced  to  pass  away  from  the  am-ctcii  area,  tlic  next  set  of  corpuscles 
W«apit  b>  tbe  am  in  the  blond  streiiin  is  subjected  to  the  same  delay  and 
ihs  iorae  apparent  fusion.  Tbe  cause  of  the  inenaMcd  adhesiveness  must, 
dnsvfere.  lie  in  the  walls  of  the  hloodvessds  or  in  the  ti>eue  of  which  these 
ktm  •  parL  That  the  increased  adhesioD  is  due  to  the  vnecular  walls  ami 
•SI  primarily  to  the  corpuscles  thenuwlvee  is  further  shown  by  the  fact  that 
if  fal  tbo  froc,  an  arlilicial  blood  of  normal  saline  solution  to  which  milk  bm 
UlB  added  be  sul)stituie<l  lor  normal  blood,  a  stosi*  may  by  irrilauta  Im-  in- 
ia  which  oiU^lobules  play  Ihe  pari  of  corpuscles,  and  by  their  Oggrs- 
bring  about  an  arreat  of  tbe  How. 
W«  am  drivt^u  to  conclude  that  there  exut  in  health  certwn  relations 
u    krtveen  thcbIouil,on  tlieuneluind.and  tbe  walls  of  the  vesseUon  the  other, 

L        ^ 


290 


kR    UGCUAI 


by  wliich  ihi"  teodCDcy  of  ihr  oirimsclw  to  mJlKTr  to  llwr  Monih'tw*:!*  i.*  kcpi 
itilhiti  ci-rti>ii)  UmiU;  tht^-  rcliUtong  ro«iic<|upiilly  di.-UTmi»o  lli<'  iiormnl 
flow,  witli  it)t  axial  strewm  ami  peripbrml  zone,  and  ihr  normal  flmount  pf 
p«riphcriil  rnnsCaiios:  in  intlnmiiiiitionN  these  relstioni,  id  a  manuer  ve 
canuuf  M  yet  fully  expltiin,  nrc  <lif>turl)e(l  io  that  the  tvodencv  of  ih« 
coriHiBcles  tu  adhvre  Ui  the  8i<IeB  of  the  vcm^I  in  larKely  and  pro<;T»8ively 
ilicr«aw(l.  Hence  the  tarning  of  the  corpUBcIes  in  spi[«  of  tlie  wideutiij;  of 
llieir  path.  ai>d  finally  tJieir  a^lomeralioD  and  fUBioa  in  L)i«  dtUended 
<ihanuels. 

We  may  add  that  the  chan^  occurring  in  the  Ta»cular  walls  also  at  least 
facilitate  the  migration  of  the  corpuscles,  and  uuxliry  the  pASMge  from  the 
hliHHl  to  tlie  tissue  of  ibe  llui'l  parU  iif  the  hUnnl,  the  lymph  of  inflan>i'd 
Hri'iM  being  richer  iu  prDteidv  thuu  normal  lymph. 

W«  tuiiM  not,  h(iW'L*ver,  ptintue  tluii  i>iihits:t  of  inStimmutiun  auy  fiirthor. 
W«  liav«Mtd  enough  tonhow  thai  ihi-  iM-riplienit  rminltinuc'  laml  (x)npH.i|iiently 
alt  l)mt  di-jx-ndti  dd  that  [i<-ri]ih<>ral  rmtftaiicv  ii>  niii  wholly  d<MmiiMv>l  by  tba 
varying  width  nf  the  minute  paiwagct,  but  is  al«o  dependant  on  ihv  vital 
ooiidilioa  of  the  tinue  of  irbich  t)ie  walU  of  tbo  paangn  form  a  fart.  WImq 
tbi  tiffu«  v  in  hcaltb.  a  certain  mi»[atiee  ii  omred  to  th«  passnBQ  of  blood 
thiYiiigh  l]ie  cnpillari«»  and  othvr  minute  y^meiU,  and  the  vrhoT«  vascular 
mcvhanidm  \*  aaa)>led  to  overcome  this  TMUtance  to  Buch  no  extent  that  n 
Dornial  circulation  can  take  place.  When  the  tissue  becomes  aflect«<),  tbe 
diaturbaooe  of  the  reUttions  beiweea  the  (issiio  and  the  blood  may,  as  iu  tlw 
later  stages  of  ipflammation,  BO  anLfmenc  the  mislauce  that  th«  poaw^  of 
th«  blowl  beoofDes  at  first  diflicuU  and  ultimately  impossible.  Aud  it  ia 
quite  open  to  us  to  suppose  that  under  certain  ciretimstanDee  tbe  reverse  of 
tlie  above  may  oecar  ui  this  ur  that  area.  ounditiouB  in  wbieh  the  nesistaace 
may  be  lowered  below  the  nunnal,  aud  l)i«  circnlation  in  the  area  quiiJteaed. 
Thtis  tlur  vital  conditiitH  of  the  tiwue  becomes  a  factor  in  the  roaintraaiioe  of 
the  cJratliition;  and  it  is  possible,  though  not  yet  proves),  that  tJi«M  vital 
eondiliono  ar<'  diri'ctly  umW  (he  cloniinion  of  the  nervoui  Kyxtem. 

§  185.  ChanfTw  in  the  pcriiihcrul  miistaiice  may  «lw>  t)e  brought  about  by 
chanjjpit  in  ihi-  character  of  the  IiI'mbI,  (ipfciitlly  fiy  diaiiKiv  in  the  rvlntivt 
aHMHiuc  of  gases  present.  When  ii  slrmm  of  .K-fihritiartHl  blood  if  nrlifidallf 
driven  throtisb  a  perfocllr  frt^li  i-xrixivl  (irgiin  sucb  as  tlie  kidney,  it  is  foana 
that  ibe  reeistanoo  to  lfie  tlou-  lyf  IiI.mmI  through  the  orgiui.  measured  Au 
instance  by  the  amount  of  outflow  in  relntinn  to  the  prasure  exerted,  rarka 
considerably  owing  to  changes  taking  pine.' in  the  organ,  and  may  be  incroaned 
by  inoreastDg  the  venouti  character  and  diminished  by  increasing  the  arterial 
CDsraeter  of  the  blood.  Kemaikable  changes  iu  the  renistaJioe  are  also 
brought  about  by  the  addition  of  small  <junntitieB  of  certain  drugs  such  as 
chloral,  atropine,  etc.  to  the  blood. 

These  ohanges  have  been  attributed  to  tbe  altered  blood  acting  oil  the 
wnllK  of  the  vessels,  inducing  for  instance  constriction  or  widening  of  tbe 
small  arteries,  or  it  nuy  Ixi  afii^iting  the  capillaries,  for  it  hsH  be<en  aa^rled 
that  the  epithelioid  itlaiea  nf  the  capillari«H  varir'  in  form  aotMinling  to  the 
relative  i|nuntiii49  of  cHrboEiio  add  and  oxygen  present  in  the  IiIimkI.  But 
this  is  Dol  the  whole  explanation  of  the  matter,  since  similar  varisttions  in 
resistance  arc  met  with  when  blood  i^  driven  through  fine  capillury  IuIh-d  of 
inert  matter.  In  nuch  exiwriment^  it  in  found  that  the  resistance  tu  the  flow 
increase*  with  a  diminution  of  ilit-  oxyg<-n  carHrtl  by  the  red  corpuscles, 
and  is  niodiHe^l  by  the  a>ldition  to  the  bIi>od  of  even  small  •juanlitius  of 
certain  dru^ 

It  is  <d>vious  then  that  in  the  living  hcxly  the  |N:ri|>h<-ral  n-)ii.ilance,  lieing 
tbe  oatcoDie  of  complex  eonditions.  may  W  modified  in  many  ways.    Ex- 


CHAKOCS  IS  THK   (iCAJfTITT  OF  BLOOD. 


291 


meure  leacben  ua  thai,  ev^n  iu  dealiiif;  with  Dun-ltviug  iii^^rl  miUlt'r.  l)i« 
low  of  Huid  Uirougli  npillary  luhet  may  be  modifiei)  ou  tliv  «■■«  liUDil  hy 
IcbtDgee  ill  tli«  subetaDoe  of  wbicli  tli«  lubea  are  CLunpistd,  iiml  on  lira 
'tuber  bawl  by  cliaoices  in  tli«  chemical  nacure  (even  imtejitradnnt  af  the 
specific  ({rnvily)  of  l)i«  tluid  wliJvb  is  umhJ.  In  Uie  living  body  both  th« 
fluid,  tlie  blood,  aud  the  walU  of  iJm:  minute  reawls,  being  both  alive,  a ro 
inveHMntly  Mibjcct  to  •-hanfri:;  the  chuii^  iu  the  oiie  moreover  are  Mpidilc 
of  neeliDg  upon  uud  iudinnnx  clmngifti  in  tlic  Otli«r ;  and,  la«tly,  the  dinii^t's 
both  of  tbeonv  and  of  ibt^  oltn^r  may  hv.  priiuiirily  mt  going  bv  cvoute  litkiug 
place  in  tome  rmri  of  tin:  body  far  amty  from  ihv  region  in  which  these 
ebutgOB  are  molifying  tlic  r(»i»Umcv  to  tiiv  How. 

CUANGEK  IN  THE   QUAKTITY   OF   JIlOOD. 

^  186.  In  an  arttficifll  Bcb«ni«  chan>^  in  llie  total  nuautily  of  fluid  in 
cirvulflliim  will  have  an  immc^liate  and  direct  ell^ct  on  the  arterial  praature, 
iorreai«  uf  tlie  (juanlity  heightening  and  decrease  diiuiuiAbintr  it.  Tbu 
elfevl  will  be  produced  parity  by  Ihe  pump  beiu|{  more  or  lew  iiU«4  at  each 
Dlmke,  and  |iartly  by  the  peripheral  reaimaiice  being  im're&ieil  or  diminixhod 
by  the  greater  or  lew  fVilneM  nf  the  small  f)«rii>herul  chnntulK.  Thi-  vi-nmia 
praaure  will  under  alt  ciroumstanoea  be  rawed  wilh  the  i  f  tluiil.  but 

Ihe arterial  prnwurc  w ill  be  raiaed  In  proportion  only  m-  .   -.  _  ■■■  ijte  lEnvtic 
wnll*  of  the  arterial  ttiben  are  able  to  exert  their  etaxliinty. 

In  the  natural  rircutation  the  dirvi't  rwulta  of  vheiigi!  of  cjuantity  are 
nimliKed  by  iximiKywatory  arraiig<;mcHlM.  Thu»  experiment  Hbonc  that 
rhea  an  aiiiRinl  with  normal  bloiHl-protcure  w  bled  fmiu  one  carotid,  ihe 
RUT«  in  the  other  carotid  Hinks  m  long  a»  the  blct-<ling  is  going  on,'  and 
'^laaios  dt'pTtwMd  for  n  brivf  jteriod  iider  the  bleeding  nae  ccsmmI.  In  a 
aliort  lime,  however,  it  regains  or  nearly  rcgaina  the  normal  height.  This 
re<»vorT  of  blood-prowure.  after  liemurrhagc,  is  witae»f«d  so  long  ns  the 
Ima  of  btood  doM  not  amount  to  more  than  abuul  ^1  per  cent,  of  the  body- 
weight.  Beyond  that  a  large  and  fre'juently  a  «uddcin  dangerous  pennaneut 
deprmsion  is  obeerced. 

The  restoration  of  Ihe  pressure  after  the  ceBsntton  of  the  ble«diD(t  is  too 
rapid  to  permit  us  to  suppose  that  the  (juantity  of  fluid  in  the  bloodVQSMt* 
is  remured  by  the  withdrawal  of  lymph  from  the  extra-vasctilar  elements  of 
the  tuuies.  In  all  probability  tlie  result  in  gained  by  an  increa^  action  of 
the  vaw>inotnr  nerves,  increaung  the  peripheral  resistaiiee,  the  vasomotor 
centres  being  thrown  into  incraased  aetion  by  the  dimbutiou  of  tbdr  blood- 
■upply.  W^en  the  loss  of  blood  has  gone  beyond  a  certain  limit,  this  vaso- 
motor action  ia  inaufllcieut  to  compensate  the  dimiuiahetl  tjuautity  (iMwiblj 
the  vasomotor  centres  in  part  become  exhausted),  and  a  consldera^>le  de- 
preuioii  takes  place ;  but  at  this  epoch  the  loaa  of  blood'  IVequeiilly  causes 
anwmic  roovulnions. 

Similnrly  when  eii  additional  quantity  of  blood  ia  imeeted  into  the  vewMrts. 
no  marked  incresKt  of  blood-preBsure  ia  observed  so  fong  as  the  vaw^motor 
centre  in  the  nieilulla  oblongata  Is  intact.  If,  however,  the  cervical  spinal 
corti  be  divitlcd  prttviouf  lo  the  injection,  Ihe  preaaure.  which  on  account  of 
the  riMiioval  of  llie  medullary  vasumotor  centre  IS  very  low,  i*  jicrmniieiitly' 
raised  by  the  injection  of  blood.  At  each  injcelion  tlie  prvmure  ri"(»,  falls 
sODMwhat  afterward,  but  eventually  rvnuiins  at  a  higher  level  tliao  before. 

>  Cbldljr  In  <Diuca'wi(*  of  il>o  ft™  oip*nlus  In  llis  vcwel  fttnn  wbloli  the  bleedlnaliflolnc  on. 
cuauiic  sft  a  f  tcki  ao*.!  of  ibc  pcripbcni  mltiaaca  and  to  InMlliis  lo  ■  sDueisl  loveiuia  at  Iba 
Hmd-fftMiire. 


I 


290 


THE    VASCTLAR    JJ  KCH  AN'ISM. 


I>r  nhirli  tln!  Icntlcncy  of  the  cuipii^clcf  to  adlioro  to  the  bluodvcxcls  U  kvpt 
wiihiri  (vrtHin  limit*;  ihese  rolHtiniin  c(>fi«e<|iie>ii(Jy  <lv4«rmLi)e  the  normsl 
tlon.  willi  its  axi.tl  ilrcam  and  |)crij)hpnil  lunc.  nnd  the  nurRinl  itmount  of 
periphcrul  rct^istance :  in  iufliiiiimationi',  thnt<  rrla{ioii»,  in  a  maiinpr  ire 
caonot  us  yet  fullf  explain,  are  di§liirbc<l  to  ttisl  the  lendcDcv  of  the 
corpusoln  to  adhere  to  the  sides  of  the  vcMei  if  luridly  ond  pru;^reMiveIy 
increaMd.  Henct  ihe  tarrying  of  ibe  oorpUBdw  in  sjiilc  of  the  irideniae  of 
lh«ir  jmth.  and  lioatly  ilieir  aggloiuentioo  and  fuMon  iu  the  diateaoed 
cbsnneU. 

W'v  may  add  itiat  the  ehangee  occurring  id  the  vasoular  walls  also  at  lout 
fueiliintc  the  niigralion  of  the  corpusclea,  and  tiiodify  ibe  paasag«  tmm  the 
bliMjd  lo  iht-  tiMue  of  the  fluid  paru  of  the  blond,  dm  lyinph  of  inflamed 
anrtii  hdng  richur  in  proteida  than  uonnal  lymph. 

We  must  ni>t,  however,  puntU(>  ihia  subjcvt  of  iiiflRiaraation  any  faiihtr. 
W«  have  mid  enough  tonhowrthat  the  [M.Ti|)heTal  reit'istauov  (and  oouaaquoDtly 
all  I  hat  dcTH-iids  on  tliut  iH-ri])lientl  rraLxance  Lt  not  wboUy  dcteRoiiun  by  IM 
varying  nidth  of  the  minute  irnxNuges,  hut  is  al«o  dcpODdoni  on  tW  vital 
eondition  nf  the  tinnw  of  wbieh  tht-  walls  nf  the  pMBitgos  form  a  part.  Whra 
the  liwiic  i*  in  health,  a  ecrtain  reoirtiince  is  onbnd  to  tlie  pMnW*  of  blood 
throii^'h  the  cumllariM  nnd  other  minulo  vends,  and  llie  whole  vafcularij 
nieehiiniEim  is  adapted  to  overcome  thi?  resistance  to  such  an  extent  that  t-' 
Dornml  circulation  can  lake  place.  When  the  tbeue  become*  aflboUd,  the 
dUturhuuce  of  the  relations  between  the  tissue  and  the  hlood  nifty,  as  in  tfae 
later  stages  of  inllHmmaiiou.  so  auL'nieol  the  resislance  that  the  paeeajce  of 
■lie  \tUioA  becumes  ai  Bret  dltlicult  and  iiltiniately  impouible.     And  it 

Suite  open  to  UB  to  AU|))Kise  that  under  certain  circurostanoea  the  reverse 
le  above  may  occur  in  this  or  that  area,  conditions  in  which  the  reibtauee' 
may  be  lowered  below  the  normal,  and  the  circulation  in  the  area  <|uickeuc<l. 
Thus  tlio  vital  condition  »f  the  tmuf  btsMineit  a  tiwtor  in  tlie  maint<-nancu  of 
the  circulation :  nnd  it  w  poMtthle,  though  not  yet  provei),  that  thc«e  vital 
oondilions  arc  directly  under  (he  dominion  of  ih«  nervous  system. 

^  18A.  Change  in  ihe  perinhornl  rcislanoo  may  also  be  brought  about  by 
ohaofea  in  the  character  of  the  blooil,  especially  by  chanra  in  the  relative 
amount  of  gases  present.  When  n  stream  of  den bnn Bled  blood  is  arliticiully 
driven  through  a  perfectly  fresh  excised  organ  such  as  the  kidney,  it  is  founds 
that  ibe  reeiatance  to  the  tlow  of  blood  through  the  organ,  measured  tot 
instance  hy  the  amount  of  outflow  in  relation  to  the  preMUre  exerted,  varic 
OunMib-niblyiiwing  to  changes  taking  place  in  the  organ,  and  nay  be  increaw 
br  inereiiBing  the  venous  character  and  diminished  by  increaaing  the  arteria 
cnarncler  of  the  blood.  Remaikable  changes  in  the  resistance  are  aim.' 
br«Hight  aliimt  by  the  addition  of  small  ijunntities  of  c«nain  drufrs  such  ua 
chloral,  atn>{>inc,  etc.,  t<>  the  hloMl. 

Tliew  chaii^  bare  been  attributed  to  the  altered  blood  acting  »u  ilw^ 
walls  of  the  viwela,  Induelug  for  iuataooe  constriction  or  widening  of  th« 
small  artertet,  or  it  may  be  aHecling  the  (uipillarieg,  for  it  has  been  asserted 
that  the  epithelioid  plates  of  tlie  capillaria»  vary  in  form  according  to  tbe 
relative  quanliliw  of  cnrbimie  acid  and  oxyjiteu  |>reiienl  in  the  blood.  But 
this  is  nut  the  whole  explanation  of  the  matter,  since  xiniilar  variations  in 
rtwlanc«  arc  met  wiiJi  when  blood  U  driven  through  fine  capillary  tubes  of 
inert  ntalter.  In  such  ox|M:irinicnla  it  in  found  that  the  resixlanoc  to  the  flow 
increases  with  a  diminutinii  of  [Ik-  oxygi-n  e»rri<'d  by  the  red  cwrpiweles, 
and  b  modified  by  the  addition  to  the  blood  of  even  small  (jnantitim  of 
eertain  dru^ 

It  is  obvious  then  that  !n  the  living  body  the  periph<Tal  reustanoe,  being 
ibe  outcome  of  complex  conditions,  may  be  mollified  in  many  ways.     £x- 


CttAyOKB  IX  TttK  QUASTITT  OF   BLOOD. 


2»I 


Mriuiet  toaobtfl  at  thai,  «Teii  id  d«aliiij;  with  iiMii-tiving  ioett  matter.  tl»e 
Bmt  of  fluid  throuvl)  cApillorj  tul>e»  may  be  ninililiis]  ou  the  on«  hutid  by 
changTw  it)  lli«  substance  or  which  the  lubut  tm  roiupoMxl,  and  on  tJ»e 
olbsr  hand  by  chaoKee  in  llie  chemical  nature  («tcii  indviH-ndcuI  of  tfa« 
•psdflo  gravil}-)  of  tli«  fluid  whic^b  is  uw-hJ.  In  thv  living  hoAy  both  lii« 
fluid*  lb*  blood,  and  the  walls  of  tli«  minute  veaMl*.  hdng  both  alive,  ara 
iooaaaastljr  aobfoot  t»  i'ban^ ;  the  diau^  in  the  one  moreover  nre  capnble 
of  rvarliD^  upon  and  inductnic  chnnji^  m  the  otlivr;  nnd,  liwtly,  the  channa 
boll)  of  theon«  and  of  the  t>lber  mav  bciiriiuarilywt  going  bv  events  taking 
plaee  in  mme  mrt  of  the  t)ody  far  nnar  fntm  the  region  in  which  ibeae 
dwagsan  iDoaiQring  the  reautuuce  U)  llie  flow. 


CnxnoFst  ix  tiie  QuA.TrrtT  of  Blood. 

i  IM.  In  a»  arlifinni  M'hemi?  ohaii^eB  in  the  total  •luantity  of  fluid  in 
dnolatiou  will  have  an  immediate  iind  direct  ciToct  i>u  tlte  arteriiit  pMMuro, 
iacraaaa  «f  j,b»  quantity  heightening  iiod  deoresae  diiDioisbing  it.  Thtt 
»IA«t  will  be  produced  partly  oy  the  pump  bang  more  or  leas  filled  at  each 
■tmke,  antl  partly  by  the  jieriphoral  re^isLniice  bi'ing  iticruii.-ieil  or  diminished 
hy  tbe  grvatcr  or  less  fitliiewj  uf  llie  muall  [wripticrul  diaiiUKU.  The  venous 
p€vmun  will  under  all  cireunKtancea  be  raised  with  the  increaae  of  fluid,  hut 
Um  arterial  pren^ire  will  be  raised  in  proportion  only  *o  long  aa  tliv  clastic 
wmlla  of  tbe  arterial  tubes  are  able  to  exert  their  ela»tielty. 

Id  tbe  natural  drvuUition  the  direct  reeutta  uf  ehaua*  of  i]aRntll]r  are 
tncullfied  by  iH>m|ienaatory  arrangemeui*.  Thus  expenmeut  ahowa  thai 
wbea  ao  animal  with  normal  blood- prexiu re  iw  bled  fmm  one  carotid,  tbe 
preMare  iu  the  oilier  carotid  rinks  ao  hmg  u  lliv  bleeding  a  gulag  on,'  and 
Wiaaiaa  denraaod  for  ii  brief  poriud  nllcr  the  bleeding  has  ceased.  In  a 
•boft  Ubm,  Dovever,  it  n-gnint  or  nearly  rcgaina  the  norma]  hdghL  Tbit 
ncanrf  of  Mood-prtaiure,  after  hemorrhnge,  is  uitneMed  so  long  aa  tbe 
loai  of  bUml  doVH  not  antounl  to  more  than  nb<jiit  :i  per  cent,  of  tlie  body- 
wai^t.  Btyond  that  a  large  and  frc<|ucnt]y  n  Mudden  dangerous  jtermaneut 
dtpnnioo  is  obser\-ed. 

The  restoration  of  the  prewuiv  nfler  the  ceasntion  of  the  bleeding  ia  too 
Ttfid  to  pennit  us  to  suppose  that  the  (juantiiy  of  fluid  in  the  bloo(TTaKlB 
IB  nutued  by  tbe  withdrawnl  of  lymph  from  the  eslra-vascuhir  eJemento  of 
the  tiSBBeii  In  alt  probsbility  the  result  is  gained  by  an  iiicreanetl  action  of 
the  TMomotor  nerves,  incneong  the  [>eriplieral  reBiataooe,  ibe  va»omotor 
cenme  beiiig  thrown  into  tooreaaed  action  by  the  dimtDulion  of  their  bloo<l- 
•apply,  ^^*len  tbe  loss  of  blood  has  gone  Iwyond  a  certain  limit.  thi»  vaso- 
laolor  action  u  insuflicjent  to  compensate  the  dfmiutalied  ([uantity  (iioesibly 
the  rasomotor  centree  in  part  become  exhausted),  aud  a  consiiiferaule  de- 
prearioo  takes  place ;  but  at  this  epoch  the  luaa  of  bloud'  frequently  causes 
aa»aic  convukioDa. 

Simllnrlv  when  an  additional  qunntily  of  blood  is  injected  into  the  vessels. 
IH>  marknl  incrvuse  of  blutHl- pressure  is  observed  xo  long  as  the  vowmotor 
lBntn>  in  the  tiKitulIa  ublongaln  is  intact.  If,  however,  the  cervical  spinal 
tarA  l»e  diviiled  prrvicm*  to  the  injection,  the  prenurv.  which  on  ocoouut  of 
the  reinuva)  uf  the  medullary  vasomotor  centre  is  very  low,  is  permanentlr 
raised  by  the  injection  of  blood.  At  each  injection  tl»a  pressure  rises,  falls 
rhat  oiUrward,  but  eventually  remiiins  at  a  higher  level  tluin  before. 

'1  rmm  which  ib«  bldedliw  li  ai>lhc  ftu. 
K  leailliic  Iu  a  («(uit^  looarliiii  of  III* 


>  CUMr  la  H»i«»uwnB»  of  Om  lim  opcatM  In  Uio  *«■ 
mimmm  ■  ci«*  mi  tf  Uw  K*)pb">l»bU*M  and 


294 


TITE  VASCl'LAB    MECHAXTBX. 


which  ascending  from  the  mucous  inembrane  of  the  stomacli  alou^  c^rtnin 
afferent  librcH  of  the  VBgui  to  the  raedulla  obloD^la.  so  augmenl  the  actiou  of 
the  card  io- inhibitory  ceutre  as  to  stop  the  heart  for  s  beat  or  two,  the  etop- 
ptti^e  beiaif  frecjuently  followed  by  a  temporary  iocreosc  in  the  rapidity  aii<l 
force  of  tne  beat.  Huob  a  passing  failure  of  the  heart-beat,  in  iij^  Mdden 
onset,  in  ila  brief  duratiou,  and  in  ilie  reaction  wbidi  follows,  very  cloodjr 
reacniblcn  i)jc  temjiorarY  inbibiiiou  bruugbl  about  by  artitirinl  xtimulation  of 
the  vmgiu.  Itut  lhft<e  Aararter*  are  not  eweutial  to  canliac  inhibition.  Fur 
it  Diuvt  be  reiurnibert'd  that  tbe  oentral  nen'oiia  aptem  potMMM,  id  the  form 
of  natural  ui-rvoim  impuli^s  of  VHriouti  origin,  n  niMina  of  ■timtdatioti  far 
finer,  nioru  delicate  and  niorti  varied  ihan  anything  we  can  effioct  br  our 
rough  niean^  of  induction  cmln  and  clcclrmt*^  ThiiK  in  nmnv  nun  of  fnint- 
IDE.  lh«  henrtb.-jiis,  inotvnd  of  nloojiiiij;  nbriijitly.  gnKlualfy  die  away  or 
fade  away  it  mny  lie  to  tin  nhiiilotc  brief  arrcsl,  bul  more  frcijocntly  invrely 
down  to  n  fcel>lf.-ne«s  uhich  in  inxuflliciciit  to  «upply  the  brain  witb  a  '(iiajitiiy 
of  blood  adei^unie  to  mniiiUiin  conxciiMiNKw.  nnd  then  in  many  cnsefi,  at  all 
events,  arc  resumed,  or  recover  strcnt'th  gradually  and  quietly  without  any 
boisterous  reaction.  In  all  probability  all  cas«B  of  uniple  fainting  from 
emotion,  pain.  dige#livc>  trouble*,  etc.,  ns  distinguished  from  the  syncope  of 
actual  heart  disciue.  are  inslancca  of  vagus  inhibition,  and  though  we  cannot 
accurately  repro<luce  their  varied  phases  by  direct  stimulatiou  of  tbe  va^ua 
trunk,  we  may  approach  them  more  nearly  by  producing  rellox  inhibition, 
n>  br  mecbanical  irritation  of  the  abdomen,  see  ^  I5U. 

^^hethe^  definite  temporary  tri'egularity  ia  ever  brought  about  by  nieitna 
of  the  auguentor  fibres,  we  have  at  present  no  dear  eviileneu;  hut  cilms  do 
oocur  of  palpitation  without  previous  stonpage.  caies  iu  which  a  few  hurried 
strong  l>eata  come  on,  para  of,  and  are  followed  by  feebkr  lieat* :  niid  ib<w 
may  possibly  be  due  1»  «ume  troiuieut  influence  of  augmentor  fibres  thrown 
into  activity  as  put  of  a  reflex  act  or  otherwise.  And  though  we  have  no 
direct  expenniBntal  cvidonco,  it  is  very  probable  that  the  acceleruiioD  or 
augmentation  of  the  Ix-itl.  or  a  combinnlion  of  the  two,  wbich  so  often  follows 
emotion,  is  carried  out  by  augmcnlor  tibres. 

Iti  all  probnbilitv.  however,  irregularity  in  the  heart-beat  is  much  more 
frequently  the  result  of  inlrinsic  events,  or  the  product  of  a  diaonlered  nutri* 
tion  of  the  cardiac  substance.  The  normal  nutrition  sets  tiie  pace  nf  tbe 
iwmal  rhythm.  We  cannot  explain  how  this  is  nflbcted ;  nor  can  «e  exidaiu 
why  iu  one  Individual  tbe  normal  pace  ia  set  aa  low  as  50  or  even  30  beata 
a  minute,  and  in  another  as  bijfb  ea  90  a  minute  or  even  more,  while  iu  uHmt 
pemna  it  it  about  70  a  ralnute.  The  slower  or  the  quicker  the  pace,  though 
not  normal  to  the  H[)e('ies.  must  be  coDtidered  a*  normal  to  tbe  iudiviilual, 
for  it  may  he  kept  up  through  lung  vean  in  an  orgtiniHin  capablu  of  ciurviug 
on  a  normal  man's  ilulicn  aiici  wurlc.  So  long  m  nv  cannot  explain  tl)u«e 
diiTcrenccs  wc  cannot  h'ipp  (o  ex[i1ain  how  it  i.*  that  a  diwrdercd  nulrilion 
bringt  about  an  irregular  hcart-bctil,  rithir  the  more  r^ilar  irregularity  of 
a  "dropping"  pulse,  ihut  is.  a  failure  of  iM-tiuence  rather  tnan  an  irregularity, 
or  a  tnorcBctivdy  irn-gular  rhythm,  such  nn  that  aceompanyiDg  a  dilated 
ventricle.  We  may,  liowcvcr,  dislinguixh  Iko  kinds  of  irregularity;  one  tn 
which,  in  spite  of  all  litvorable  iiulntive  conditions,  the  cflrdiac  substance 
cannot  secure,  even  perhaps  fur  a  minute,  a  steady  rJiytlini ;  and  another  in 
which  the  rhythm,  though  normal  under  ordinary  circumstances,  it,  so  to 
•peak,  in  a  condition  of  unstable  eouilibrium,  ao  that  a  very  alight  cliange  in 
oooditions,  too  much  or  too  little  blood,  or  aoroe  aiuall  nllemtion  in  the  com- 
iMsition  of  the  blood,  or  tbe  advent  of  some,  it  may  tie  sligfat,  nervous 
impuW.  augmenlor  or  inhibitory,  devehipa  a  lempornry  irregularity. 

J  19L  No  out  thing,  perhaps,  ooncemiug  the  heart  i*  more  atrikiug  than 


SOME  reaTL'RKs  or  cinci-LATios. 


20S 


r 


the  &ct  lluu  B  bniTt  which  lua  gon«  on  beaUug  for  manir  y«H»,  will)  only 
tctdpormry  tn^gularititt,  KD<t  thoce  few  and  far  lwtwe«ti.  u  liiiurl  whirh  muxt, 
thambiv,  haw  axeculcd  n-ith  long-continued  regularity,  mimy  niilliim*  uf 
bcAU,  afconld  sudHvnly,  appHrendy  without  warDiog,  utlcr  a  brief  Hiokorioz 
•tnintt,  oeue  to  biMit  any  tnor«.  But  we  niusl  remember  tliiu  «u-h  beat  m 
■n  eOuK — an  eflort  noKOTer,  which,  as  we  bav«  *e«n  (^  1J>&),  ia  th«  bett 
tluu  the  heart  can  make  at  the  niomeni,  the  accompliwhaienl  of  mch  beat 
ia.  a>  to  apeak,  a  hurdle  nbich  hsit  tu  l>e  le»pe<]^<ine  of  tbo  long  Mriea  of 
hairltea  which  wake  up  tin-  t«te«:ple-tbn«f  uf  lifi^  At  anyone  leap  failure 
may  ocear;  m  loo^  aa  failure  doea  not  occur,  w  long  a*  the  Ix-tit  is  made, 
ma<\  m  lUr  proportiou  of  the  ventricular  conUtnla  are  di^chargmi  iiilo  the 
graat  rawl*,  the  chicJ*  cmt  i*  Kttinol,  and  whcthrr  the  leap  is  mn<te  dumaity 
or  well  in,  rvbuivcly  oonaidereu,  of  w:c(iadnry  importance.  Uut  if  th«  beat 
b*  oat  nuitli-,  vvxrything  alnwat  (providt^l  that  the  miss  be  due  not  to  vtgaa 
tnhitMtiai)  Irat  to  intrinno  eTenia)  is  iinfnvurable  for  a  succeeding  bent;  the 
myatMKMia  moloculor  change*,  by  which  rhe  actual  occurrence  of  une  beat 
pfwpana  ibo  wav  for  the  next,  are  missiop,  the  favorable  iril)ueuoc«  of  the 
extra  hmJi  of  blootl  through  the  cornnarj'  arleriea  due  to  a  preceding  best 
mwm  mimiag  aito,  and  even  the  distension  of  the  cardiac  cavities,  at  fint 
fltTntaUSt  ipeodily  (>•*»  the  limit  and  beooinee  unfaTorabl&  And  tlieie 
aolowanl  influencea  accumulate  rapidly  as  the  Unit  miaa  is  followed  by  a 
•■eowi.  and  by  a  third.  In  this  vrav  a  heart,  which  has  tie»i  brought  into  a 
Mate  of  unstable  e<|uilibriuni  by  disor^lered  uutritiuD  (at  fur  iniitttDce  by 
ltu|ierfp<.-i  curuuary  ciretdatiuii,  such  an  tn^im  tu  ncoum[>any  diMiaMf  of  the 
aofflie  Talres  leadiDK  to  rcgurf^ilution  fmm  tlie  aorta  into  the  ventricle,  in 
whiUi  CMC*  sudden  death  is  »i>t  uncommon),  which  i*  ablv  ju.->t  to  accoinpliob 
••eh  beat,  but  u»  more,  which  hiw  but  a  scanty  saving  stun-  of  energy,  uniler 
Mn«  etrain  or  other  untoward  inDucncc,  misses  a  leap,  falls,  and  is  no  more 
•Utt  to  rise.  Dwibtlen  in  such  vki>c:<  i-outd  adc^uole  ariiflcial  aid  be 
pfOOMly  applied  in  time,  could  the  fallen  heart  be  stirred  ereii  to  a  single 
good  Mat.  the  favomble  reaction  of  that  beat  mi^hl  briu]*  a  successor,  and 
M  once  more  start  the  series  ;  but  *uch  a  jwriod  of  >{race.  of  potential  recovery, 
is  a  brief  one.  Kven  a  coarse  skeletal  muBcle,  wlten  out  oB*  from  the 
drctdation,  soon  loses  its  irritability  beyond  all  recovery,  and  the  heart  cut 
otf  from  its  own  influence  ou  itaeif  runs  down  so  rapidly,  that  the  )wn(id  uf 
poMible  recovery  is  measured  chieDy  by  seoonds. 

S  IM.  Tbming  now  to  the  minute  arteries  and  the  peripheral  resistaoc* 
wUcb  tbey  teguiate,  we  ntay  coll  to  roiutl  the  exislenoe  of  the  two  kinds  of 
iiirhanlsin,  the  vaso  constrictor  mcchanisTO,  which,  owing  to  tbc  matntcnanc* 
hj  tb»  entnd  nervous  sntem  of  a  fmic  innuenoe.  caiiljc  wnrknl  \mth  in  a 
pOiids*  comicrichir,  and  in  a  negative  dilator  direction,  and  the  vii«i>diUtor 
OMeluuiEan,  whieh,  as  (iir  as  we  knuw,  cxcrt«  its  influence  in  one  direction 
oaly,  rU.,  to  dilate  tbc  blomlvrMcIic  Tbr  latter  dilator  mechanism  wems. 
■s  m  hkT*  Itaa,  to  be  used  in  fpceinl  innlaooes  only,  an  cocn  in  tbc  cases  of 
th9  chorda  tymiMUii  and  ncrvi  crijri-iitiv ;  the  use  of  tlie  former  couatrictor 
MSghanirai  appears  to  be  more  general.  Thii;  the  relaxation  of  the  cutaae- 
ans  arteries  of  the  heiul  and  nock,  which  is  the  cwcnlial  feature  iu  blushing, 
se«BW  due  to  mere  loea  of  tone,  to  the  removal  of  constrictor  influences  pre- 
rioasly  exerted  through  the  vaso-constrictor  fibres  of  the  cervical  sym|m- 
tlkctia  Though  probably  dilator  flbres  pass  directly  along  tlie  roots  of  the 
esTTical  and  of  certain  cranial  nerves  to  ibe  nerves  of  tiie  head  and  neck, 
we  hare  do  evidence  iliai  the^e  come  into  play  in  blushing ;  as  we  have  seen, 
Musbinc  mav  be  imitated  by  mere  section  of  the  oen'ica]  syrofMtlictic.  So 
■ho  tl>e  "  icfiiv>  "  and  rednos  uf  the  skin  of  the  whole  body,  i.  e.,  dilation 
jmwally  of  the  cutaneous  arteries,  which  is  produced  by  external  warmth. 


296 


VASCITLAII 


ie  probiiblr  nnothcr  iiiMniice  i>f  ditiiiiii^licd  activity  >if  tonic  c»nMnrt<>r  iiiAu- 
enns;  though  th?  rcmill,  that  tho  <)iUlion  produced  bv  irarriiiug  an  tiniiumi 
in  an  oven  is  ervatet  than  that  pniducpd  bv  §cctiun  o(  nerrcs,  tMtns  to  poa&t 
to  the  dilator  nbre*  tor  tlie  ciitHneou^  vcetels  which,  as  we  have  seea,  probft- 
l>l;r  exist  in  the  Hciatic  and  bmchinl  p)exua«e  and  possibly  in  nil  the  spitinl 
nerves,  alito  taking  pan  in  the  nclion.  A  similar  lues  of  cuuBirictor  action 
in  the  ciitaneou«  vessels  uiav  be  the  result  of  certain  emocioDS,  whether  gmitf( 
Ml)  far  an  actual  bluHbinij  i>{  the  body,  ur  merely  produdQg  a  "  glow."  Timi 
elTeri  i)^  coll),  on  the  tither  luind,  and  of  certain  eiuotioiu,  or  of  emotion 
tinder  certain  eunditiuna,  U  tu  increase  the  uonetrictor  aetion  on  tlie  nitnuiy  ' 
oar  veAwlH,  »n<l  the  *k!n  grown  pule.  It  may  be  worth  while  to  point  out, 
that  in  lioth  thr  :iK<v  >  ,lii4,  wliile  both  the  I'old  and  wannlh  {iroducv  thrir 
eDect,  chiefly  m  '  .  i'tiI.'>  thrnugh  the  central  nL-rvinii  Ht'sLeni  luid  vi;ry 

slightly,  if  al  all,  by  dimcl  action  ou  the  ulcin,  their  action  on  thr  c^ntr 
nervous  svftv in  i*  not  oininly  a  gvnenil  augmentation  or  inhibition  of 
whole  vacomotor  centre.  On  the  eontrary,  the  cold,  while  it  oonstricts  the 
«utaneouH  vcMels,  so  act*  on  the  vnsomotor  oentrv  a»  tu  inhibit  that  portion 
of  the  vasomotor  centr<-  which  governs  the  abdominal  splanchnic  area; 
while  \vm  blood  is  carried  to  the  colder  skin,  by  tlic  o{)oning  up  of  ll 
apliiuchnic  area  more  blood  is  turned  on  to  the  warmer  regions  of  ttie  bodv, 
and  the  ri»e  of  blood-pressure  which  the  constriction  of  the  cutaneous  veM«M 
tended  to  produce,  and  which  mii^ht  be  undesirable,  is  thereby  prevented. 
Conventely  when  warmth  dilates  the  cutaneous  veeaeU.  it  at  the  same  time  , 
cotiatrictn  the  ubdominal  aplanohuie  area,  and  preventa  an  tindeeirable 
of  preMtnre. 

The  warm  and  flushed  condition  of  the  akin,  which  follows  tlie  drinking 
of  alwholio  tluidw.  U  probably,  in  a  dimilur  manner  the  re>ult  of  an  inhibi- 
tion of  tliui  imrt  of  the  vneoinoior  centre  which  governs  the  ciiuneotu 
arl«rie» :  and  it  is  probable  al*o,  thni  except  for  the  local  effect  of  the  fluid 
on  the  gastric  mucoutt  manibrai)c,  whereby  some  amount  of  blushing  of  the 
niBtric  bloodvefeels  takes  pliii-c  iim  a  rcHex  act,  thii>  eHcct  on  the  vessels  of  tfafl 
akin  is  aoconi|)anied  by  nn  inverse  coiiMrictor  action  in  the  splnnchnic  anti 
This  last  point,  however,  has  not  been  provci.1  experimentally  and  may  not 
occur,  since  the  intluence  of  the  alcohol  is  nt  the  same  time  to  increase  the 
heart's  action,  and  thus  to  obviate  the  fall  of  preMure  wbioU  would  certainly 
occur  were  the  cutaDeous  and  splanchnic  vascular  are«  to  he  dilated  at  the  ^ 
Mine  time.  This  elfeci  of  the  alcohol  on  the  heart  may  be  a  direct  action  0(4 
the  alcohol  on  ilic  (-iirdiiic  Hulwtance.  being  carried  thither  by  the  blood ;  btit^ 
the  ctlvct ,  in  being  an  aiignienlAiiuu  of  the  force  and  acoeleratioa  of  the  pace 
of  tho  hcart-lKuii  of  a  temporary  cliaracter,  followed  by  a  reaction  tn  lli« 
direction  of  fceblvnem  and  xlonueM,  »a  atrikingly  rvMtnible  tlicefltMla  of  arti- 
ficially stimulating  tin-  •anliac  augmentor  fibrts.  thai  it  is  at  least  probable 
that  the  alcohol  diMv  net  ujmii  the  cardiac  an^tmuntor  mechanism. 

S  193.  The  inrtiicnci-  on  thi'  l»dy  of  cxcrcis".'  illunlmtat  both  the  maiuiePi 
in  which  the  two  \-awiilar  fnclon,  tho  hcurt-beat  and  the  peripheral  rasiiM 
aoce,  are  modified  by  circutiislancra.  and  the  mutiml  action  of  these  on  each ' 
other. 

When  the  body  riawee  from  11  condition  of  comparative  rest  and  (juiet  to 
one  of  exertion  and  movement,  the  metabolism  of  the  skeletal  musoloa  (aud 
of  tlie  nervous  dystem)  is  increased  imd  more  heat  is  generated  in  them. 
We  know  for  certain  that  the  increased  metabolism  throws  into  the  blood  of 
the  Tc^iiu  coniinv  from  the  muscles  an  increased  amount  of  carbonic  add|i 
and  It  U  probable,  but  not  m  certain,  that  it  also  loads  the  blood  with  lacliol 
acid  and  other  metabolic  ]ir(>iluc1s :  at  the  same  time,  there  is  an  increiiMvl 
miisuniptioD  of  oxygen ;  the  blood  of  the  body  leiKJs  to  become  km  arterial 


80JIK  FEATtFKBS  OF  CIBCULATIOK. 


297 


and  man  T«noii».  In  dMiing  i«i(li  nvpiriition,  ne  vtinll  tm  tlinl  tW  iiiflii- 
«B<»  thtu  «[i*Tl«J  OB  llic  bl«Kl  IfKil*  to  aa  iiifTnuw  in  tb«  mpirnlor}-  move- 
nteijU,  BDil  «<■  ihiilt  furtlior  rv  thai  Uui  nimv  vigorous  working'  of  lli« 
rMpiniinrT  Dump,  «inoo  il  [immirfpN  ihr  flow  ol*  l>)on()  to  mkI  through  tlw 
bmrt  «Dii  liiD^,  iiiiKkvns  ntiil  xtrrngthcRu  itic  livnrt-lxrale.  l'<«»iblT  this 
tDwi  nK^-tiniiicnl  rneet  of  th«  more  vigoroiM  bratthiug  is  sufficient  bj  iiaclf 
to  aocuuiii  l^T  ihr  JiicrMM  in  the  freqnenoy  and  vigor  of  th«  fa«nrt>  srtiou, 
ImiI  it  i>  nion?  than  jmilwble  ihni  il  i*  Inechatif^  condition  of  (he  tiloivl, 
whirh.  tihilv  it  hurries  on  (he  respiratory  pmnji.  al*o  stiiiiiilates  tbe  vafcutur 
paritp,  rilh«r  )>y  n  direct  HctioD  on  the  ttardJac  Mibe(ance,  or  thn>UKh  iJie 
wv<liuiii  of  the  ceD(rKl  iier^'oua  «n1eni  anil  (he  nuj^inenuir  tibivH.  If,  na 
vxprnmenla  Mem  to  obow,  the  ioereated  vi);or  of  die  reaptnitor}'  inoveiiienti 
MMapeoatcs,  or  even  (wei^eompeoMtefl.  the  leiidenrv  of  die  whole  blood  to 
bvoM&e  more  veuou*,  >o  thnl  during  exervae  (he  blood,  vhioh  ts  ilUlribitt«d 
bjr  Ibv  wvta,  bMumIIv  dont  Dot  oondiin  more  carbiiuic  ncid  itnd  Icm  oxygen 
tkaii  the  rest  but  even  iIk'  rvvAne.  then  ihete  eflbctti  uuK  be  due  to  aome  of 
UMiiroducti  of  muMMiInr  wctalxilititn  otWr  iban  carbonic  >cid. 

The  Mme  cbaDgr<l  coiKliliiin  <>f  hlnin\.  while  it  tliUR  excidw  the  henri  diUU* 
like  ftitiuteoni  rnvclv,  m  if  rlmrly  shown  by  thL-  wnrni  Ilunhed  tk'iu,  nnd  at 
tb«^  Nimv  linx^  ihniwi  into  nciivity  ihc  pcwpimtory  nicchnnisra  viilh  vrhicJi 
WIT  ahalt  hrr«MA4-r  have  to  dc»l.  Tlier*'  can  bo  no  doubt,  v  wo  uhnll  tv 
Inler  on,  ihnt  the  iwrspiratiun  which  acoompaaies  niuxculiir  cxcrciw  i« 
bfmght  abotit  by  m4«n<  of  the  central  nervous  tpAvm,  luid  wc  mnr  nlnxHt 
with  eertainlr  conclude  that  ihc  dilation  of  tlm  cutaneous  arteries  i"  also 
bcoocbl  about  by  means  of  (he  c«D(rBl  nervous  system,  ami  most  pmbnbly 
bjr  HMOi  of  an  inhibilioa  of  that  part  of  the  vasomotor  centre  nhich  nmin- 
tatap  aoder  ordinary  circunis(anc«a  a  greater  or  less  tonic  constriction  of  the 
«alWMUUt  arteried ;  how  far  (hiit  may  \m  lutointc^l  by  the  tt)iec!a]  acliou  of 
T«KMliUtor  (tbivs  we  do  not  know. 

Tbii  widening  of  the  ciitane<>U!>  ar(cri«>  dimiuishe*  larjccly  t)i<;  jieriphend 
raiaUDce:,  and  do  (cmU  (o  lower  (he  blIllld-p^?0llr<^  Aforeuver,  with  Mich 
«flbrt  of  each  tkclclal  niiut'lc  thr  minute  artvri<«  of  tluit  iiiu»cle  ure  dilnt<.-d, 
•u  thai  during  pxcrrise,  and  (fpccially  during  vigorous  oierciac  calling  into 
action  nnnv  slieleuil  musclvs,  there  mtmi  be  in  the  body  at  large  a  very  con- 
aUifabk  widening  of  the  minute  nrleries  distributed  to  the  various  miucln, 
aad  fa  eonafqncnoo  a  very  considerable  diminution  of  the  peripheral  resist- 
aac*,  TImw  (wo  dtrninuiions  of  peripheral  resistance.  cu(aneoUB  and  mus- 
cvtar.  vuuld  tend  to  lower  the  blood-prenure — a  result  which  would  be  most 
iojnrinut,  since  the  increased  metabolism  of  the  uusclee  demands  a  more 
rapid  rircnUlion  in  or<ler  to  geit  rid  of  the  produfiU  of  metabolism,  ajxl  fur  a 
lapid  circulation  n  bij;h  blood-pressure  is  in  RHiat  cases  ttMCenrv,  and  in  all 
tasea  atlvaniageous.  The  evil  is,  in  part  at  all  events,  met  by  Lne  increased 
brrr  and  frequency  of  the  heart's  beaii^  lor,  as  we  have  aaid  again  and 
acatR.  the  mean  IiIchmI -pressure  iii  the  product  of  the  licart-beat  working 
afaiiMt  the  peripheral  resistance,  and  mar  remain  eon.tluut  when  one  ftwtor 
b  inoaaMd  or  diminisbed,  provided  that  the  other  factor  be  propoitionatelj 
Jbafaikbed  or  increased.  It  is  poanble,  th<-ii,  that  tht.-  mere  increaae  ia  the 
heart's  Iteat^  are.  during  eien-tw,  iiuDiHeul  to  ntiutndiM:  the  diminution  of 
pcripbenil  resistance,  or  even  (o  niiiM>  (he  blood-prtwun;  above  the  normal : 
aad,  indeed,  we  Aod,  as  a  matter  of  <iic(,  that  during  exercise  there  t*  >ueb 
an  iacnase  «f  tlie  mean  bloixl-prrasurc.  Hut  il  is  more  than  jinjluiblc  that 
■Uteb  valuable  labor  of  (he  heart  it  ccDnonii»-d  by  itetKrnlixinff  ibe  imminent 
Ml  of  blood- pmmi re  in  luinther  manner.     Il  would  appear  that  while  thai 

Crt  of  the  vaMimotor  centre  whicJi  governs  the  cntanaous  vascular  area  i> 
tog  inhibited,  that  jiart  which  governs  the  abdominal  splanchnic  anta  ii, 


298 


THK    VASCULAR    MKCHANISM. 


on  tlie  contrnry.  Ik-Idj;  uiiginunt«<].  Atitl  in  thin  WAV  ii  Joiiblo  «n<1  i*  frnioed. 
On  ihtr  cini-  hnnd.  thu  mean  Mood-Dnviure  u  ouiiiiuinml  or  incn-tuu-tl  la  a 
Taorc  ccunomioil  ninimpr  ihnn  by  ini.'ri.-«i>ing  ihr  b«Tl-bvnli>,  anil,  on  tb» 
uthiT  hand,  tlic  blowl  during  tin-  cxi-rciw  i*  iiirncd  Rirar  from  ihr  digtwlire 
Orgnnv,  vihich  iil  the  time  nrc,  or  "Ughl  lo  be.  at  r«»t,  niia  Uiercfure  iV|uiriDg 
COiDpiinvtivol)-  little  blood.  Tlicee  orgnn*  riTtitinly,  ill  all  events,  niigbt  not 
during  cx«n;iBe  to  be  eogn^pd  in  the  (n«k  "f  digmting  am)  absorbing  (bod, 
and  tne  nld  saying.  "af\er  ilioner  th  awhile."  may  serve  ns  an  illnstmtion  of 
the  wurliiug  of  ID«  Tascular  mechatiiaiu  with  which  we  are  dealing.  The 
duty  which  some  of  the  digestive  organs  have  to  carry  out  in  the  vray  of 
excretion  of  nielabulic  waal«!  products  is  during  exercise  probably  taken  on 
by  the  flushed  and  uere|>iriiig  skin.  It  is  true  tbai  a(  the  beginning  of  s 
period  of  exercise,  before  the  tkiu,  so  to  speak,  baa  settled  down  to  its  work, 
an  increased  Ron  of  urine,  dependent  on  or  accompanied  bv  an  incrttased  6ow 
of  blood  through  the  kidney,  may  make  its  appearance ;  but  in  this  case,  aa 
rre  jihall  see  IhIit  on  in  dealing  with  Uie  kidney,  the  flow  of  blood  (brougli 
the  kidney  nnty  he.  incrvujed  in  spite  ol  cijUBtnetlon  of  the  mt  of  tbe 
splanchnic  area,  ftad,  bc«idcii,  Mich  an  initial  incrtnse  of  urine  wpeedily  givea 
vray  to  a  decmwe. 

i  194.  The  eflect  of  fnod  on  the  vowidnr  nKvhnniKin  nflbnlii  a  market)  con> 
Inwi  lo  the  effect  of  hoiiily  lnb«r.  Tlir  mo»t  marked  rwult  i*  n  widening  of 
the  whole  nbdominnl  »platichnie  nrtn,  accompanied  by  to  much  coo«lriction 
of  the  cuiAncoiis  vn^culHr  nren.  nnd  ho  much  increase  of  the  heart's  l>eat,  a* 
isBUlGcient  to  neutrnlize  ihc  lendenev  of  the  nidcnin^of  the  splanchnic  an* 
to  lower  the  meao  pressure,  or  perliaps  even  sufficient  to  raise  slightly  the 
utean  prewure. 

Any  large  widening  of  the  citlaneous  area,  especially  if  accompanied  by 
muBcuUr  labor  and  the  incident  widening  of  tne  arleriee  of  the  muscloo. 
ntmld  lend  *o  to  lower  thi;  general  bloud-prewure  i  unlew  met  bv  a  wasteful 
use  of  cardiac  energy)  »»  iiijuriously  tn  lamm  the  flow  througli  I  he  act  ire 
diseating  vijtceni.  A  moderate  conntrictlon  of  the  cutaneous  vtMiels,  on  the 
Olner  band,  by  throwing  more  bloixl  on  the  ahiluminal  >j>lanchnic  area  with- 
out tiiiking  toe  heart,  is  favorable  In  dtgt«lion.  and  is  prulmbly  tlie  jihytio- 
bigicn!  cxpUiutUon  of  the  old  saying,  "  If  you  cat  till  you're  cold,  you'l) 
live  lo  be  old." 

In  fact,  during  life  there  sccma  lo  bo  a  continual  give-and-take  iN-'twun 
tlio  bloodvewcle  of  the  somatic  and  thono  of  llic  xplanchnic  diviHJoRS  of  the 
body  :  lo  fill  the  one.  the  other  i»  prop)rti»i lately  emptied,  and  vice  Jtrtn. 

i  195.  We  have  seen  (^  174  i  that  ecrtnin  aHervat  nitrva  of  the  vngus  form* 
iug  in  the  rabbit  a  separate  nerve,  the  deprrasor  nerve,  air  osMciatod  with 
tite  vasu-coustrictor  nerves  and  the  vasoiuolor  centre  in  such  a  wrsv  that 
impulses  tiassiug  ceutripetally  along  them  from  the  heart  lower  Ihe  blood- 
pmAure  by  {limiuishing  the  peripheral  r««istiuice.  probablv  inhibiting  tli« 
tonic  constrictor  Intluencea  exerted  along  the  abdominal  splanchnic  nerves, 
and  io,  as  it  were,  opeaiag  the  splanchnic  Hood-gales.  ^Ve  do  not  jpoaaeaa 
much  exact  information  about  the  use  of  these  aSerent  deprewor  fibres  in 
tltc  living  t>n()y,  l>ut  proluibly  when  the  heart  is  laboring  against  the  blood* 
preasurc  whii'li  Is  t<>o  high  tor  its  powere,  the  condilbii  ot  the  heart  Aorta 
imnulsrs  which,  piiMliig  alon^  the  deprcMtor  fihrfs  up  to  the  medulla 
oblongata,  temper  down,  so  to  s}i«tk,  the  blood-prenuro  to  suit  tlic  cardiac 
strength. 

Wo  have,  moreover,  reason  lo  think  that  not  only  dom  the  hejirl  thus 
regulate  the  blood-preMur«  by  means  of  the  depressor  fibr«.  hut  also  that 
ibe  blood-preesure.  acting,  nt  it  were,  in  the  reverse  direction,  rrgula(i.>  the 
bean-beat;  a  too  high  prtiwure,  by  acting  directly  on  tJie  cardio-inliibitory 


SOMK    FKATl'ftKS  OF  CIRCULATION. 


399 


ectttra  to  tbe  tnedulla  oblougata  (either  direcllv — thai  i»,  a*  llie  rasult  of  the 
tvcnku  cotitliuou  or  ih«  toMiiUa  iloelf— or  inilirectl}',  by  imitulMS  rencbiiig 
ikit  tD<«lulla  mluHK  ufl'ercDt  nirves  fmni  vnrinut  nnrtit  uf  the  biiHy)  aiay 
mm)  iohibilnrv  iu>p4iltn>  down  tltc  vngiix,  ninl  wt  nhicki-ii  <>r  tone  <luwii  tliv 
hran-bmti. 

1b  tb«  riillowiiig  wctions  of  ih'u  work  w^  shall  mm;  rcpvntt^  in»tMiw*, 
railar  til  or  rvcti  more  Mtriking  tb*n  tbo  tibovc,  of  the  iDBnnpt^nit-ot  of  tho 
ra«cuUr  ni««liniit«m  by  nxmns  of  ibo  ncrvouB  tyflem,  and  wv,  ilicrcfui^,  n«'<-d 
4vtU  BO  Ir>ng4rr  on  the  siibjccl. 

Ve  amy  sini|tlr  ropent  cbnt  at  the  centr«  lie*  the  cardiac  mtuciilar  fibre, 
nd  al  tite  periphery  the  plain  niusciilar  fibr«  of  the  lainute  artcrr.  On 
Ant  two  p)eni«nli  the  central  nervous  By»l«m,  directed  by  this  or  tbst 
■Bpolw  nachin^  it  alonf*  adereot  nerve  librw.  or  nflected  directly  by  this  or 
Ikal  iiillacoM,  »  dnrin;;  life  continually  playing,  now  augmeDtin^,  now 
iakAkiBC,  now  tbe  one,  now  the  other,  and  so.  bv  help  of  ine  elasticity  of 
ibruUneaand  tlie  luechaniau  of  tbe  valves,  direciiug  tne  blood*flow  accord- 
iif  ID  Uie  needa  of  ibe  body. 


BOOK   II. 

THE  TKSL'ES  OF  CHEMICAL  ACTION,  WITH  THEIR  RESPECTIVE 
MBCHAKISMS.    NUTRnTON. 


CHAPTER  I. 


THE  TISSfES  AND  31E0HANISMS  OK  ULGEHTION. 

f  IM.  The  food  in  pswiofc  alon^  tbc  aliin«Dtary  canal  is  Bubjeclcd  lo  ilic 
I  of  certain  juicM  supplied  by  the  secretory  activiiy  of  the  epilhdiuai 
irhfck  liue  the  o«nal  itself  or  wliich  form  part  of  its  glaiidiilnr  appuii- 

^ja.     Tbew  juices,  vii.,  saliva,  iputtrJc  juice,  bile,  pancreatic  juio.',  and 

ih*  mcmImm  of  tl»eiruall  and  large  inttstiuea,  poured  upon  and  minding 
»ith  tbt  tooi  produce  in  il  sucb  chaujtnt  that,  fmiu  bein^  largely  imwifiilile, 
it  liiiLiiiiiM  Iwgdy  Mluble,  or  otheniviiie  niudify  it  in  •iicti  a  way  that  the 
iMftf  put  v(  what  IK  ealeo  paaMt  into  the  blood,  cither  dini^ily  by  lacana 
«f  tbo  eapillanra  of  the  alimentary  caual.  or  bidirei-tly  by  invAm  uf  th« 
IftCUftl  ttjWeta,  while  tlic  :<ma]l<-r  part  u  diycharged  as  i-xorimU'iil. 

Hmmc  pU\B  of  the  food  irhiuh  are  thus  digi-slcd,  ab»c>rbed,  and  made  use 
at  by  the  body,  are  «poken  of  as  j'ood-»tuff*  (they  hare  also  been  called 
mlummUuy  prinetpU»i,  aod  may  be  convonjemtly  divided  into  four  ureal 


1.  fntrittt.  We  hare  pr«vioualy  (5  15)  ^ken  of  the  chief  cliaraclen  of 
tbi*  rlwa.  and  hare  dealt  with  leveral  memben  in  treatioK  of  bloiid  and 
■MM^.  We  uav  twre  repeal  that  in  general  oan]|)C6ition  ihey  contain  in 
100  part*  bv  weight  "in  round  numbers"  rather  more  than  15  part*  of 
■Itngtn,  ratber  more  tliau  SO  part<4  of  carbon,  aboul  7  parta  uf  hvdrugen, 
aad  ntbtr  mnre  than  20  parta  uf  oxyj^en ;  though  eeMotially  tlie  nitro- 
gtoooi  taxlica  of  food  an<l  of  the  bi>dy.  tbey  are  made  up  of  carbon  to  llie 
yrttn*  of  more  than  half  their  weight. 

TIm  nitroocnous  bwly  ijflalin,  whicb  otN'iin  largely  in  animal  fmxl,  and 
•OOM  albtr  Dodic*  of  Uv  imjxirtauce,  while  more  cliMcly  alliixl  In  jiroteid 
bodla  tbaa  to  ooy  other  claw  of  onauic  aiiliKianixs,  ditfer  considerably  from 
pMKfla  in  comporition  and  cq>emlly  in  their  W Imviur  in  the  body :  they 
am  Mt  nf  lofRciant  im|>-frtnno(-  to  form  a  clnx*  by  tbcniwlvi,'?<. 

2.  flat*.  Avquently  but  crrontim-ly  calUii  hydrocurh'inx.  Thi>c  vary  wry 
wld<^ly  in  chemical  compMition.  ranging  from  >uch  a  comjiarativcly  »imptu 
fat  a*  liulyriu  ta  the  highly  complex  Incithin  I^Tl);  they  all  poawn,  in 
virw  of  tbe  oxidation  ot  both  tboir  carbon  and  their  hydmgen,  a  Uf:ge 

iBt  of  iMtential  energy. 
(.itr^k)dral€i,  or  lugare  and   ftarchn.      These  ponces,   wdght   for 
rdativety  leas  potential  energy  than  do  (iit«:  they  already  contain 
Melrea  a  large  an>ouiit  of  oonbined  oxygen,  ami  wbcu  completely 
WlMbtd  ^TS  out,  wei^t  for  weight,  lees  heat  than  do  fat*. 


302      TKL   TISSUES   AND    Ub'CHAX] 


■I.  Saline  or  miiitnl  h&dui,  and  tuatcr.  Tbeae  Balu  ore  for  ibe  most  part 
luorKaiiic  huIib.  Hnd  this  cluits  dill^n  Arom  the  three  [•receding  cImhs  in  lu 
iiiDcli  &*  itif  iiTc^riiliieM  of  ita  memben  to  llie  body  lieia  not  so  much  in  the 
iitiiouut  i)f  eiiLT)cv  wbich  may  be  given  out  by  ih«ir  oxiduioii  lu  iu  the 
rnri»ii«  iiiAuenoes  irbioli,  by  their  pmencv,  cliey  exerciw  on  Uic  metabolic 
CvrnU  of  tlic  liudj. 

Thaw  (wvcml  f»iid-Hiuffi»  are  vunouitly  uctud  uprni  in  the  Mvcr&l  parts  of 
the  alinicnlHry  cunul,  and  we  mny  dlMtiiiguiidi.  ai^  tht'  fixid  yeuMt  along  th« 
digMtivi-  tracl,  three  inuiii  singea:  dizestton  in  the  mouth  and  tlonuich, 
digestion  in  ibe  unmil  iute»Une,  and  dtgcvtion  in  tlte  large  intcsliiM.  In 
many  animnU  thi7  lin>l  singe  is.  lu  a  Inrge  extent,  prcparolory  only  to  tbc 
second,  nhich  in  nil  the  aiiimnlx  w  the  ctnge  in  which  the  food  iindervoes 
lli€  ^'rentcsl  change;  in  the  third  stage  the  ohangea  begun  in  tbc  preruMU 
siugee  are  ci>m|ileted,  and  l)ii»  »tagc  is  evnecinlly  characterized  by  the  nbeorp- 
lion  rif  tliiiil  from  the  interior  of  the  alimentary  canal. 

It  will  be  convenient  to  study  tbeee  stages  more  or  less  apart,  though  no4 
wholly  so,  and  it  uill  also  be  convenient  to  consider  the  whole  enbjecl  of 
digesiioti  under  the  following  heads  : 

Firsi,  the  characters  and  properties  of  the  various  juioea  and  the  clian^ 
which  they  bring  about  in  the  food  eat«n. 

Secondly,  the  nature  of  the  proocaaeo  by  meam  of  which  the  epithelium 
i:t]\A  of  the  various  glands  and  various  trncta  of  the  canal  are  nble  to  niauu- 
finctiire  so  many  various  jiiicea  out  uf  the  common  wurve,  Uie  blood,  and  the 
manner  in  tvhioh  the  secret<iry  activity  of  the  cells  ia  n^lated  and  nibjecled 
to  the  needs  of  the  economy. 

Thinlly.  the  niechiiubiu»,  here  us  elsewhere,  chieHy  of  a  muscular  nature, 
by  which  the  fooil  is  pa.'wed  along  the  <!anal  and  moat  efficaeiitly  brought 
into  contact  witli  thi-  wvprnl  juices. 

Fourthly  and  lastly,  the  nienns  hy  which  the  nutritious  dimtcd  malArial 
U  separated  from  the  undigested  or  excroineiital  inatcrini  and  absorbed  into 
the  blood. 


The  CHABACTEttS   kVVi  PBOf-BRTIES    OF  SaUVA    AMD  GaBTBIC  JuICB. 


iSb/i'vu. 

S 197.  Mixed  mlira,  as  it  appears  ui  llie  moutb,  is  a  thick,  giniry,  gvn- 
ernllv  frothy  mid  turbid  fluid.  Under  the  micrnfcopc  it  is  fteen  to  contain, 
licsidcs  the  niulf'Ciiinr  d^brin  uf  fuod,  )>acti>ria,  and  other  organisms  (fre- 
■uently  cnr'pt'ininiic  i>iH>n.-«),  eji  it  helium  M-'ulen,  muc(iu»KMrpuscli?,  and 
rgraoukts,  and  tin-  "ocalUH]  salivary  corpiuM-lest.  Its  n-nctton  in  a  healthy 
subject  it  nikniino,  specially  uhwi  the  wcretion  in  rbiimlnnt.  When  the 
saliva  is  scanty,  or  when  the  mibject  xuflcni  from  dynncp^ia,  the  reaction  of 
the  mouth  may  be  ncid.  Halira  contains  but  little  solid  matter,  on  an  aver- 
age probablr  about  •'■  p«T  cent.,  the  s[>ecilic  grnvily  vnrying  Irom  1O02  to 
IfMIS.  Of  iKese  solids,  rather  ln«  ihnn  hall,  nbout  'l  per  cent,  are  salts 
(including  at  times  n  minute  ijuanttty  of  potasAium  sulphocyanatei.  The 
organic  bodies  which  can  Iw  recognised  in  it  are  globulin  and  serum  albumin 
(see  ^^  m,  17),  found  in  sniaii  i^uaniilies  only— other  obscure  bodies  occur- 
ring in  minute  (pianlity,  and  mucin  ;  the  lotter  is  bv  far  the  most  conspicu- 
ous organic  constituent,  the  glairinces  or  ropiness  o^  mixed  and  other  kinds 
of  saliva  being  due  to  its  oreseoce. 

Jfim'ii.     If  acetic  acid  be  cautiously  added  to  mixed  saliva,  the  viscidity 
of  tiie  saliva  is  increased,  and  on  further  addition  of  the  acid  a  semi-o{ia4ue 


SALIVA    AND  OABTIttO  tVlCB. 


of  the  «ativa  liiii|iic).     Ttiil  ropy 
niili  II  ):liu»  i\mI,  utiriiikf,  hcoominff 
o|i«r|o«,  i-liop  %••  (lie  ^liiw  t>Hl.  iiuil  iiiny  be  lliutt  nrmnriil  rn)iii  iho  flutil.     If 


■MAiaiM  QUI,  Iwvtng  ihc  nvt 
wbieb  u  Biticiii.  ifuirrvd  onn-l'iillv 


^ 


th«  '(UUilJty  of  Hindu  K*  ■mali  and  the  mIivm  bv  violnilly  «liiikcn  or  *tirml 
whtiv  ibe  ■<;»il  iv  Mn^  ■•lik-<).  ibr  niuriit  ■*  npl  to  In-  prrcipitacil  in  HnkM, 
aiu)  Bwy  thra  b«  w-iwrittvl  br  tiUrntion.  It  may  be  fi<lilcd  thai  tbc  |>nxtipi- 
tettoB  of  miiciii  by  Hci<l  is  ^raaily  ioflu«noed  by  tbc  prracncc  of  otidiiim 
cbloride  uid  other  mIih  ;  thus,  ifUtr  tbu  uddition  of  sodium  chloride  mc«lM; 
mtrid.  even  in  coD*idernblo  exenw,  will  not  cuuso  a  ]>reci|>iljile  of  mucin. 

Mucin,  thus  preporeil  utd  piirifi«l  by  wiwhing  with  aeeiic  ncid.  Biralk  ooi 
in  water  without  actually  dissoUini; ;  it  trill,  bowi-vor.  dissolve  into  a  viscid 
fluid  readily  iu  dilute  (l>.l  per  cent.)  solutions  of  {lolaniuni  hydrate,  more 
slowly  ill  tolulions  of  alkaline  salts.  In  order  to  l31ler  n  mucin  solution, 
grrai  ililution  nilb  nsier  is  DeceeearT. 

.Muciii  it  pre4.-i|iiiaied  by  siroDf;  alcobul  and  by  various  metallic  sails;  it 
nwy  aha  be  precipitated  by  dilute  miiisnU  acids,  but  the  precipitate  It  tlien 
•olabla  in  exeeas  of  (be  acid. 

Macin  KiTea  the  tbree  proteid  raaolions  roentianed  in  $  15,  but  it  iii  u  vrrv 
mtDfdex  body,  ntore  coni|>lex  even  tlian  proleidii.  for  by  treuiment  witli 
flilutv  mineral  acidti  and  in  other  vays,  it  miiy  be  coiivertet)  into  tumx  fonn 
<if  prutvid  ( acid -albu milt  when  dilute  minenil  acid  i»  u^),  while  nt  the 
•an*  tin>c  then  is  formed  a  body  which  apjtmni  to  Iw  carbohydrate  aod 
rHMobto  a  sugar  in  harinj;  the  power  of  r^ducinii;  cupnc  sulphate  soliitioiw. 
Salatiou  of  mucin,  moreover,  ou  mere  keepiiiK  are  ant  l»  lose  tlielr  viw^diiy 
umI  to  becoroe  converted  into  a  proieid  imt  unlike  the  body  peptone,  whicn, 
•a  ««  •liall  me.  is  llie  result  of  gantHc  di){C«iiton,  and  into  n  r»lucin)(  lH>dy. 
iMTvral  kinds  of  mucin  appear  to  exist  in  variouM  animal  bolin,  but  (hoy 
HNB  all  to  Agree  in  the  ennraoler  that  tbcy  can  by  appropHnle  treatment 
be  split  up  into  a  proteid  of  some  kind  and  into  a  carbohydrate  or  allied 
body. 

il0t.  Tbo  chief  poipoM  Mrved  by  the  saliva  in  dilation  is  to  moiateu  and 
soAui  ibe  Ibod  and  to  aansi  in  mastication  and  def-lutitioo.  In  some  animala 
Utia  is  its  only  ftindioD.  In  other  animals  and  in  man  it  lios  a  B[ieciiic  milveait 
■etsoa  itiiMiDeof  the  foo<l'«tut&.  Such  minerals  as  are  suluble  iu  slightly  alka- 
Ub0  flaids  are  dissolved  by  il.  On  fata  it  lias  no  dEtct  save  thai  of  produeini; 
a  rwTf  Aeble  emulsion.  On  proteida  it  lias  aba  no  speciHc  action,  (houftb 
I  will  M  of  meal,  cooked  or  uneooked,  apfwar  greatly  altered  al\er  iliev  biive 
DMB  ma)4lcateil  fur  M>me  time;  the  chief  atteratioD,  liowevvr.  whicli  thus 
tskaa  niare  is  a  cbunp>  iu  the  hjeuto^'lobiii  and  a  genernl  wifleiiiuK  of  tbo 
Huaealar  fibros  by  aid  of  Ibe  alkiiUniiv  of  ilte  saliva.  Of  oounc,  wh«D  par- 
tidaa  of  fond  ar«  retaiued  Ibr  a  ifmg  time  in  the  mouth,  as  in  the  intonbcas 
or  is  cavities  of  tV  teeth,  the  bacturia  or  other  organtsm*  which  are  always 
preaent  in  (he  luuiitli  may  pnxluce  niucli  miirc  profouiKl  chaiigm.  but  lli«se 
ar*  Dot  (be  li-yitini»ii>  priiducls  of  tite  action  of  saliva.  Tbe  charaoteristio 
pruuerty  of  saliva  i*  that  of  coovcrtiiig  starch  into  aocns  form  of  sugar. 

AH'on  of  taiira  mi  tlarrfi.  ]f  tn  a  quantity  of  boilvd  starch,  which  fs 
aliraya  more  or  lew  viscid  and  somewhat  opaque  or  turbid,  a  small  luniility 
of  luiva  be  added,  it  will  be  IbuiMJ  after  a  short  time  that  an  important 
cJmuhK  has  taken  pliicr.  inannuch  as  tbe  mixture  has  lost  its  previous 
viacMUtT  and  become  thinner  and  more  transparent.  In  order  lo  umler- 
tfand  tais  chanj^  the  render  must  bear  in  minu  the  esiftteoce  of  the  follow- 
in  bodies,  all  belonging  to  the  claH  of  carb>jhydratee: 

1.  SIoitA,  which  ibrnu  with  water  not  a  true  solution  but  a  more  or  Icfli 
viscid  mixture,  and  gives  a  characteristic  blue  color  with  JMlise.  Tbe  for- 
aala  is  CfH^Ot,  or  more  correctly  (C^U^OJ'  since  the  molecule  of  starcb 


SOi        TUK   TIS8UI8    AND    MECHANISMS   OF    UIOBSTION. 


i«  some  multiple  (n  being  not  lose  than  6)  of  the  aimpler  formula.  A  kind 
of  March  known  aBMi»Af<r«Mi-cA.irhile  giviD};kbIu«  color  nit  )i  iodine,  fornia, 
unlike  ordinary  etarch.  n  clenr  Boliilioa. 

3.  Dexirins.  diflerinf;  from  slitrcU  iu  forniiu]^  u  clear  eolutioa.  Of  these 
Ihnv  are  al  least  two ;  one  eryt/irodextrln,  otten  xpokeD  of  simpl}'  as  dextrin, 
giving  a  port-wine  red  color  with  iodine,  and  second,  aehrooilfrlrin.  whk'h 
pves  no  color  at  all  with  iodine.  The  formula  for  dextria  ia  the  Mm«  u 
Ibu  for  starch,  but  has  a  smaller  molecule  and  might  be  reureaeuted  by 
(C.H.,0.)-. 

:t.  IJtxlTon-,  aliM>  called  glucose  or  gra[ie-Mgar,  f^ivin^  uo  coloration  witli 
iodine,  )>ui  vharacteriiEed  bj-  the  yavivr  ofreducinj;  t-uprio  utid  other  metallic 
Mlt« ;  thus,  when  dextrose  a  boiled  with  a  tluiil  known  an  Fehlin^V  fluid, 
which  i*  a  smlution  uf  hydrated  cupric  osidc  \a  an  escoM  of  caustic  alkali 
and  double  lartmie  of  nodltini  and  potaaviiiui,  the  cuprio  oxide  i«  reducMl 
and  a  red  or  yellow  de[Miiiit  of  cupronw  oxide  \*  thrown  down.  Thiii  miction 
»ervnt  with  olhen  na  a  convenient  l«»t  for  dextrow.  Neither  riarvh  nor  that 
(■omm(in<-«l  furra  of  iiuf!;nr  known  ai*  cnnc-HUgar,  give  the  mclinn;  wlH'ther 
the  ilvxtrinti  dn  U  doubtful.  The  formula  for  dexlnwc  Is  C,H„0, :  it  is  more 
niuiplc  tliiin  thutof  rtarch  or  dvxtrin  and  conlnini  an  addition  H,0  for  every 
C,.  Cnlike  Klarch  iind  dextrin  it  can  be  obtained  in  n  cryttsJline  form, 
either  frum  n<]ue(tui>  iJiliitions  (it  being  rcadilv  ttoluble  in  watori.  in  which 
case  the  eryHlals  contain  water  of  crvetal ligation,  or  from  its  solutions  in 
alcohol  (iu  which  it  n  sparingly  fi.<lubfe),  in  which  ca/n  tlie  crrstals  hare  no 
iralerof  cryetalliitBlion.  Solntions  of  dextrose  have  a  marked  liex I ro- rotatory 
jMwer  over  rays  of  li^hl. 

4.  Mallote,  very  similar  to  dexlr>>«c,  and  like  it  capable  of  reducinf;  cunrie 
salts.  The  formulu  ia  somewhat  ditl'ereni.  being  C,,H„0,|,  Besides  this,  tt 
difl^rv  from  dextrose  chielly  in  its  smaller  power—/,  t.,  a  tn^'eo  weijihl  will 
not  oonvvrt  w>  much  cupnc  oxide  iutu  ciipriiUH  oxide  as  will  the  name  ncieht 
of  dcxtriHtv,  and  in  havini;  a  ntronger  mlatory  ai'tlou  on  rays  tif  light.  I.iks 
deztroMi  it  can  Ik  crvntallixed,  the  eryitals  from  ui{ueou»  itolutioiM  conlainiog 
water  of  cryxtaltiuition. 

Now.  when  a  ijuantitv  of  Hlarcli  is  boileil  with  water  we  may  recogoiu  in 
the  viscid  imperfect  ikilutioD.  on  the  one  hand,  the  prmenoc  of  the  *<«rch 
by  the  blue  color  which  the  iidditlon  of  iodine  give*  rinr  to  ;  and  on  the  other 
hand,  the  abecnco  of  sugar  (niBltosc.  doxtnm).  by  the  fact  that  when  boiled 
with  Fehling's  fluid  no  reduction  takes  place  and  no  cuprous  oxide  is  pre- 
cipitated. 

If,  however,  the  boiled  starch  hv  submitted  fur  a  while  to  the  ucliou  of 
saliva,  especially  at  a  eomewhat  high  temiiemture  such  as  '.f't"  or  4*1°  (.'..  it 
ia  found  that  the  subsequent  addition  of  iodine  j^iva  no  bkie  color  nl  all,  or 
very  much  less  color,  showing;  thiit  the  starch  has  disappeAr«l  or  dimiuished ; 
on  the  oilier  hand,  tbe  mixtun-  readily  gives  8  precipitate  of  cuprous  oxide 
when  boiled  with  Kehlin^'s  fluid,  allowing  tliat  maltose  or  dextrose  ia  present. 
That  is  to  Nty,  thi;  mVivu  has  converted  the  «Ukrcb  into  maltose  or  dextrae. 
The  prewncc  of  the  iirDviuimly  ab^ut  Mijfar  may  also  be  shown  by  fermenta- 
tion and  by  the  other  tcstM  for  sugar.  Moreover,  if  an  adetjuntely  larg« 
ijuantity  of  rtarch  he  Mibjected  to  the  char^,  the  sugar  formed  may  b«  uo- 
loicd,  and  tts  cluirat-iero  deteruitnetl.  Wheu  this  is  done  it  is  found  that 
while  tKimc  dextrnic  Is  formeil  the  greater  |iart  of  tlie  sugar  which  appear*  is 
in  the  form  of  mattow.  As  i»  well  known,  starch  auir,  by  the  action  of  dilute 
acid,  be  converte<l  into  dextrin,  and  by  further  action  into  HUgar;  btit  ibo 
auptr  thus  formtil  i«  ulnar*  wbnily  ilextrtwe,  and  not  maltose  at  all,  Tbo 
action  of  raliin  in  lhi#  res[iect  diHerw  from  the  action  of  dilute  ncid. 

While  the  conversion  of  tliv  starch  by  tli«  saliva  it  going  on  the  addition 


I 


I 


I 


I 


SALIVA    AKl)  nASTRIC  Jl'IOR. 


SOS 


I 


mT  KKliiM>  fm|iiFDtU  give*  rise  lo  a  red  or  vinlel  color  iustead  of  u  pure  blu«, 
but  when  \ht-  tonvenioa  b  compile  iio  oiitanUion  bi  all  \»  oluervciil.  'Die 
>)i[inirM)i-«  i>{  this  red  color  indJcaUa  llie  prak'Hi-e  i.f  ilextriii  (uryihrock-x- 
Xiin)  ;  the  rMel  color  b  due  lu  the  r«d  beini;  mixed  wilb  the  blue  of  still 
oaeliMi|{«d  Btarcb. 

Tbp  «ufieannee  or  dextrin  ahowsilial  the  aotioiiof  the  saliva  oii  the  Mtarch 
is  M>iiienbat  oum|ilex ;  ami  tht*  h  Hiill  runlier  prutrcd  hv  tbi;  fai-t  tliat  even 
wbca  ilie  mUIvk  has  eoRipIeiea)  its  work  ibe  whole  uf  ihe  #tnrrh  doc«  not 
nsppCBr  m  malhac  or  H&itr(«e.  A  ooiuiderable  (|UuDti(y  of  Ibe  uther  dei* 
Uin  («bn)od«xinD)  alwiivx  ai>p«-im  nii'l  rfriitiinn  unchanged  to  the  end; 
•Dd  tb«rs  are  pnihalily  mv.thI  iitbL-r  hmlies  also  rnrmtd  out  of  tlit>  Mlirob, 
tbenlatim  pN)>>rti<>ii»  van-iiiK  ucv-inliu^'  to  cirL-umRUmcM.  The  ohango, 
thfrfdW,  thiM]{li  )icrliu[i*  lie  may  :<(Huik  nt'  it  in  a  gencnil  way  lu  ons  of 
hjrdratiiHt.  onuot  b*  •ihibilrd  undfr  H  :<iniplf  Ibrmula,  aud  vo  may  rv«t 
«aaiait  for  lb*  prtMnt  with  the  Plalvnieiit  lliiit  Mnrch  Mhen  fuhjccted  io  tbe 
Wlion  of  aaliva  is  roDvertrd  nbicHy  into  the  Mignr  klxiwn  as  mallow  kiiIi  a 
coQiparaiivelr  snisil  •^uaiiliiy  uf  dt-x(T\«c  and  lo  some  exl4.iil  iiiio  nchroo- 
dntriD  1  «r\'thnH)exinii  apjicantie  tempontnly  onlr  in  ihe  prooes'),  other 
bodica  CM  w'hioh  we  iiee<l  not  dwell  kcinc  formed  al  the  same  time. 

Kam  iiiibuik-d  »Mrch  undertow  n  similar  chants  but  at  a  much  glower 
nuv.  Tbts  is  due  to  tho  hu-t  that  in  iIk-  curiouslr  formed  elarch  guraiu  tbe 
Mm  Staivb.  or  ffnuuJtft,  is  invested  nith  coals  of  rrHuloe^,  Thi^  latter 
aaaloria),  which  requites  previous  Imatment  with  sulphuric  aeid  before  it  will 

R'<M  ifav  blue  rrwiioR  on  the  addition  of  iodine,  is  apparently  not  acted  upi>n 
'  isliva.     Hence  the  saliva  can  only  j^t  at  tbe  Kraiiul<«e  by  iraverdin;;  tbeJ 
euatsof  (fllidivie.  and  the  conversion  of  the  formi^r  lit  thereby  initi'h  hlndere^ 
BIMJ  delajred.  m 

S  IM.  The  cunveraiuii  of  starch  into  Mifiiir,  and  this  we  mar  speak  of  Ml 
Um  anrlulytic  adi^m  nt  niUvh,  will  ^  on  at  tin-  unliiinry  lfiii|i<'ralurc  of  ih« 
aUnorpneTe.  The  lower  ihir  icmperalure  ihi-  kIowit  the  chan^*,  and  at  alHHit 
U'  C.  ibe  iV'nverwkiti  i*  indetinilL-Iy  pn>l»i))t:ed.  AAcr  exfHniorc  to  ihix  culd 
fur  V¥«u  a  ooDaiderubk*  time  the  action  rvciimroetKi^  when  the  tempcratiira 
is  again  raiaed.  Increase  of  ten)|>i;ntture  up  lo  almut  3>'>**-4(>°,  or  even  a 
littlii  lit){ber,  Avon  the  change,  tlw  gresiU.wt  actirity  being  «id  to  be  mani- 
ImUd  at  about  40\  Much  beyond  this  {luiitt.  however,  increase  of  tempera- 
lurv  becnnwa  injurtou*.  ninrkcdly  so  at  60"  or  TU":  and  saliva  nhicb  has 
barn  boiled  Tor  a  l<-w  minutm  not  niih-  hits  no  netion  on  »tarch  while  at  that 
UmpenUurp.  IhiI  iI'nw  not  rc^in  its  puwenon  cooling.  By  being  hailed, 
lb*  amylolytic  activity  of  saliva  i*  permameotly  deetroyed. 

Tfav  action  of  saliva  on  starch  is  mi>>t  rapid  whcfi  the  reaction  of  the  mix- 
tun  is  ncutnl  or  nearlv  so;  it  is  hindered  or  arrcMeit  by  a  disliuclly  acid 
futioa.  Indeed,  the  preseoce  of  even  a  very  small  <piaDtity  of  free  acid, 
U  all  erents  of  hydniCDloric  acid,  at  the  temperature  of  the  body  not  only 
•MpMids  tlw  action  but  speedily  leads  to  penuanent  abolition  of  tite  activity 
«r  ibi  JQim.     Tbe  bearing  of  thiit  will  be  seen  later  on. 

Tlie  action  of  saliva  is  hamperol  by  the  preaenoe  in  a  concentrated  Mat6 
of  tbv  pmluct  of  its  owu  Kctioo^-ihat  is,  of  MKnr.  If  a  small  (|iianiiir  of 
s*liva  tie  added  to  a  thick  man  of  boiled  Ktarcb,  the  action  will  alter  a  wliile 
•lacken.aud  eventually  ouroe  to  aliu»!ii  a  Bt«ii<Lsiill  long  before  all  lite  starch 
hw  beeo  convened.  On  diltiliuK  the  mixture  with  water,  the  action  will 
RMMiiineDoe.  If  Ihe  pmduots  ■>f  action  lie  removed  tu  lOon  aa  they  are 
Ihmed,  dialysis  for  pxatn|ile,  a  mubII  ipiantilr  of  saliva  will,  if  .-lufliuienl  time 
be  allowed,  convert  tnio  uitrnr  a  verv  lnrK«,  one  might  aliixnt  miy  an  indeR- 
Dilc.  i|uatitity  of  stamb.     Whether  iW  particular  cou'litunnt  on  which  the 


S06       TBE   TlSSl'BS   AXI>    UKUUAMISMli   OP   OIOBSTIOX. 


iictivity  »f  uitiva  (lv{>eHi!it  a  nt  all  oouauMed  iii  ita  acllon  luu  not  at  pmeot 
bK'it  ilditiitcly  iH*tiIt-il, 

On  wimt  runnrittioiilH  iln  the  iiiiivlolytic-  vinuo»of  nnlivii  ilepeixl? 

If  Hilivu,  lilti-rcii  mill  iliu^  (rw)  fiiiiii  timob  uf  iu  mucin  ami  fmu  o(li«r 
formci]  c(>ii»tilueuM,  be  ticiitcil  uiili  irii  or  liAevu  lirni.-*  iu  bulk  of  alf»Ut>l, 
It  prcei])itiilc  w  forintKl  I'lmiftiiiini^'  Ih-ki'Ii-ii  "liivr  tiilMtarioi-H  ull  tlio  [inalfii 
tntittor!.     L')>on  »l-(iiii)iiig  iiixlf r  tlic  ntciilml  for  mmur.  linn-  i  M-vcriil  duyn),  Uk 
protciiis  thus  prccipilsU'd  Iwc'iiuc  i-'Higiituii-'l  nini  iii«»liib!c  in  wnti-r.    Hcut-*,! 
an  aqueou§  cxirurl  of  tho  pnvi|HtnU',  mmb-  nllor  iJiis  intfrviil.  oi>nliiiiui  vrry 
Utile  proteid  DiiiCcrial ;  yd  it  is  cxcccibn^ly  nclivo.     Mnix-ovrr,  by  oiIkt 
more  elabornte  iii€lhuil»  tWn  nitiy  be  ubtainvd  fmrn  mlivn  mlulioiis  wliich 
appear  to  be  almost  onlirvly  firv  from  pmidds  and  yet  an>  iiitcnsi'lv  amylo- 
iytic.    But  even  tbcw  probably  CDiitain  other  bodici*  beeide*  tlie  nallr  active 
CDoetituent.     Whatever  the  active  eubstniice  be  in  itee'f.  it  exists  in  #ucb-| 
extremely  fimall  quaatilies  that  it  bos  never  yet  been  satisfaL'torily  iaiflattJj 
uud  indeed  the  only  clear  evidence  we  bav«  of  ita  exiHtence  is  ibe  manifeaia-^ 
lion  of  its  |>eculinr  jKiwere, 

The  ialieni  fenlureaof  this  body,  ibis  aniylolytic  ageut,  wliieh  vn  may  call 
jilyniin.  are  then  ;  let,  ita  presence  iu  minute  ami  alm<:iit  inappredable  •|Uiui- 
tity.  2d.  the  close  dependence  of  its  aeiivJIy  on  lcin|terature.  Sd.  ita  pernia*^ 
n«nl  and  total  destruetiun  by  a  liit;h  K^uiperature  and  by  various  clteiuica' 
reafceiitit.  -1th,  the  wanl  of  any  clear  pr<>i>f  that  it  iioelf  undergoee  an] 
cbaiifce  iluriiiji  the  omnireetation  of  ittt  ponen — tbal  w  to  ?ay,  theener 
neCMMiry  for  the  iraui^forniatiuu  which  it  eflecta  i/om  not  ramir  out  of 
if  it  iit  at  ull  uoed  up  in  iit>  action,  the  low  t»  mtlier  that  <>f  nimple  vrtar  i 
tear  of  a  ninrlune  thiiu  tbal  of  a  «iib«lanoe  exmodcd  to  du  ivork.  5tli,  tfaa 
action  ubiih  it  inducM  in  probably  of  tucb  a  Iciiid  (Kpliltitig  ui>  of  a  molfr 
ail«n'ith  iimuiuption  of  wnier)  ns  is  elTcclcd  by  thai  particular  cuiM  of  agmU 
calkd  "  byilrolytic." 

These  features  mark  out  the  amylolytit^  active  body  of  saliva  n«  belongin 
to  the  clasB  of  ffnamt^ :'  and  we  tnoy  henceforward  speak  of  the  amylolytie" 
ferment  of  NilivD.  The  tibrin-femient  (^  'M)  is  so  called  because  its  action  in 
manr  ways  reeeniblcs  that  of  the  ferment  of  which  we  are  now  speakiof;, 

§  «00.  Mixed  nliva.  whose  properties  we  have  just  diseuned,  is  the  result 
of  the  mingling  in  various  proportions  of  saliva  from  tbe  jmrotid,  submax- 
illary, and  the  subliiifrual  j^laDos  with  tbe  secreiiou  from  the  buccal  Klaad& 
Tlie«c  constituent  juices  have  their  own  tjjieoial  character*,  anil  thee©  are  iMt 
tbe  same  in  all  animals.  Moreover,  in  the  oaine  individual  tbe  aecretioo 
diR^rs  in  composition  and  propertiea  accurdiug  to  circiimHtaiicu>;  tbiia.aswe 
ahall  see  in  detail  hereafter,  the  nliva  from  the  subiuaxillary  (;l<uid  aecTMcd 
nnder  the  inlluence  of  the  chorda  lympanj  nerve  i*  <litfen!Ut  from  that  which 
b  obtained  fruui  the  same  ^land  by  ^tiuiiilatin^  tlic  syjii])ulhetic  nervK. 

la  man  piire  parotid  saliva  aiaj-  easily  be  oliiiiiiied  by  introducing  a  fine  canala 
Into  tbe  o^ioiiing  of  the  Stcnnnmn  dud.  sud  -iil>cm>xillAry  saliva,  or  rather  ~ 
mixture  of  luhmaxillary  and  lubliiiKUiii  MiliTH,  by  •iinilsr  citheterixation  of  (ti 
WhnitoDian  duct.  In  aaimatii  the  duct  uiay  be  dimtucinl  out  iinil  a  canula  iodo- 
duced. 


I  Parauoumajr.  fcf 'be  j.mcuIM  loul.  bt  divldwl  liil«t*D  olMWi.  oonunun  Ir  (aQart  orpaalial 
■od  wMraoManf.  I>i  ibo  funiwr,  xca>i  ia»}  b*  wkni  «■■  trpll'kiiiwTn  MsmpiB.  The  IbrmeaiMttv 
MaTtljroTTMutirMohlMdsiallipfloiivmlnnof  lawlnio  alcohal.  Ii  derauileiii  •  >ri  |^F  ll(ci>rilM 
joM-all.  I'nIvB  itie  jriaatorll  be  Urlna  and  raDitU^ual.  ftrniaiituliin  iltm  iwi  inkt  iJiirv  -.  mhta 
tbii  TOUI-cttll  iU*>  IbruiraUtlDn  p«*m  :  aiul  iici  tiilMancp  obWIniHl  Irnrn  Itwilulit  r^rucil  laM.  bf 
piMluMloa  Htlh  ■Iniluil  or  otliucwli*.  •■■II  th<v  rtw  tn  altMhnUe  (irniicTiMllaii.  The  atirniry  fer- 
meat  Mow  to  tbi-  Inl(«rrlu«:  ti  l>o  nilnlinm.  nul  aUiliie  uriaiuiiii  II  Ve  >tmn.  U  iiiay  Iv  sJtItil. 
Ii0«**tr.  Ilwt  iJO^IiiT  (lie  iimnlin]  rcnucni.  tbu  ittrt  fit  Tiiiuuim.  [initintB  it>  vilvct  lir  nxwni  at 
■a  grttaMf  nuutiaalSBd  KfMtnt  wlilcli  II  swivnieK  but  wlilcb  li  laiinullftiely  MiBiteawBT  Willi. 


BALIV.t    AND  flASTRIC  JDICR. 


807 


I 


I 


k 


IHuutiil  lalivft  in  niito  in  cimr  anil  liropM.  not  vucii) ;  lli«  rvRition  of  llie 
fifM  drops  (vctrtetl  in  oAcn  acid,  the  sncerriltng  portiuiu,  at  nil  eV«nl«  when 
tlw  Sum  ia  at  all  copious,  arc  alknltae;  that  ia  to  ay,  tbp  iiMura)  wcn:t)<in 
h  alkaltae,  bot  thin  niiiT  W  ubectirvd  by  ncid  cimngc*  taking  plnco  iii  ihfl 
laitl  wliich  hflB  b««n  rciain^H  in  tlie  iluct,  pof«iblv  by  the  tnniiatioa  of  an 
«ScnB  of  csrbouic  acid.  On  »lnnding  the  clear  tliiid  becotitcti  tiirhid  from  u 
pnapltate  of  t-alcic  carbunalc,  due  to  sn  escape  of  carl>oiii<-  ni-i<l.  It  ciiu- 
taiiu  clobalin  aiid  some  other  foruia  of  albuniiu,  with  little  or  do  mucin. 
I'iXjuuuu  Milphocyauale  may  aitio  soiuetiiiie^  be  delected,  but  stnicUiml 
■Amtota  are  aoaeni'. 

Babnaxilbu'y  tsHva,  in  nmn  and  in  mort  aoimals.  difl^re  from  parotid 
mUt*  in  beinr  more  alkaline,  and  from  the  preH'Oce  of  mucin  more  viscid ; 
it  flMtalB*  Mllvary  curpuscltv.  tliat  is  ImmIics  cIimcIv  resembling  if  not  iden- 
tits]  wilii  Uueocvii-H.  and  oAeu  iu  abundance  uumrphouH  roaaaea.  The  K»- 
calM  eborda  mlWa  in  the  dog,  tliut  b  to  Miy  wHva  obtained  by  atiniulatiog 
ibe  cborda  tym[i«ini  nerve  (of  ahich  ne  *liall  preeeiitly  fti)ettlci,  it  uiidvr 
ontlMuy  circuiu«ianc(«  thinner  and  Uvn  viM:id.  cvntaiua  tew  niucin  and 
tovar  Mruciural  element*  ihaii  lite  (u-calle>l  tiytn pathetic  •&]]»,  which  ia 
nMrltmbU)  for  it*  viacidily,  its  •trvcuiral  elemtjita,  and  for  It*  larger  total 
oTWiib. 

Sabtingual  Mliva  !•  mor«  vl»cid  nnA  oontalna  more  salts  (in  the  dog  about 
1  DV  nmiL)  than  the  »iihniaxil!nry  i>itlivn. 

The  action  »f  milivii  viiri<«  iu  inlci>»ity  in  diflbrent  auimnlti.  Thu«  in 
nan.  tke  pig.  the  piim'W'pie,  and  the  rat.  Ixitli  parotid  and  lubnuixillary 
and  tnixvil  MilivB  arc  nniyrolyiic:  the  tuhninxillary  Nilivn  hdn];  in  moit 
tmm  tDore  active  itinn  the  pnrolid.  In  the  rabbit,  whik-  the  siibmnxillvy 
aalira  baa  scarcely  any  action,  that  of  the  parotid  is  cticrgctic.  The  snitva 
ol  th*  eat  b  much  lew  active  than  the  above ;  thai  of  the  dog  is  Mill  )«iw 
acfive,  indce*!  is  alnioei  ineit.  In  the  hor»e,  shecii.  and  ox.  the  ani^lolyiic 
jnrnm  <if  either  mixed  naliva  or  of  aoy  one  of  the  constituent  juion  arc 
titnntlj  feeble. 

WWre  the  wliva  of  any  glatul  in  active,  an  a<]tieouH  inAiaJon  of  the  Mimo 
glanil  in  also  adive.  The  im|>onancc  and  bearing  of  this  Matrmrnt  will  be 
aiiMi  later  un.  From  the  ai]uroti»  infuciiiu  of  ibt  gland,  a«  from  Mdiva  ilwlf, 
ihm  frnneiit  nay  bo^pproximately  itwiatcd.  In  norae  eaao*  at  leiut  •one 
fcrmrat  may  lie  exlrarted  from  the  filand  even  when  the  secmion  is  iuelf 
naciive.  In  fact,  a  n-ady  n>othoil  of  preparing  n  highly  amylolytic  liquid 
totnaldy  free  from  protcid  and  other  imparities  is  tn  minec  fioely  a  gland 
knunn  to  liaw  an  active  Kcrction,  tnicb,  for  imrfance,  as  that  of  a  rat,  to 
dehydrate  it  by  altouinp  it  to  stand  under  absolute  alcohol  fur  some  dars, 
and  then,  having  poured  olf  moat  of  ibe  alcohol,  and  removed  the  remainder 
br  evaporation  at  a  low  temperature  to  cover  the  |Hecta  of  glaod  with  strong 
gijcenii.  Though  tome  ol  the  ferineni  apjienrs  to  be  ooMrtqred  by  the 
alcobal,  a  mere  drop  of  such  a  glycerin  extract  rapidly  converts  stnrcli 
iatoMigar. 

0<utrie  Juift. 

I  901.  Tbn«  is  00  difficvliy  in  obtaining  what  may  &irly  be  eonitideTed 
as  a  normal  ralivK;  hut  tlierv  are  many  oMtaclta  In  lb«  wav  of  dctermiidjig 
tbe  normal  charactrtv  of  the  H-CnHion  of  the  rtomach.  \Vbeii  no  food  u 
lakrti  the  stomach  is  at  rest  and  no  n-crriion  take*  places  When  food  ie 
takes,  the  eharactera  of  the  gs*<ric  juice  Mvrcted  are  obscured  by  tlw  food 
vilb  which  it  is  mingled.  The  ^atlric  membrane  may,  it  is  true,  be  aril- 
ftcially  ilimulnled,  by  tuucb  for  itutancc,  and  a  sccreliou  obtoincd.    Thb 


6m 


TIIK    t'lt^SirBS    .KSV    MKCHAS'ISMS   of    rtlOKSTIOI 


we  may  ei^eflk  nf  ii»  i^utrk-  jnico.  but  it  tnnv  Ik-  (liuihtnl  wlM-thtr  it  uagh 
to  be  L-i>i)ai(l«rL>d  ns  imrmat  ;;[isiric  juice.     Ami  iiiile^'l.  ii>  <nt;  Elinll  wv,  ev 
Uie  juice,  wliii.'li  is  poured  IdIo  iIic  stomach  duriog  n  mcnl,  vnncs  in  i»nii 
siliua  aa  digetitiou  U-  goiii);  ou.     Uenoe  titp  cbaractcru  wliich  vie  slinll  git 
of  juiSBtrio  juioe  must  be  L-i>D»iiicr^l  as  having  a  j^noral  vulue  only. 

Uaslric  juiM,  obuined  in  m  iioriiial  ii  (.Miidittoii  as  puaaible  from  the  h«tillhy 
SKHnaeb  uf  a  lusting  dog  by  uieaiia  of  u  gastric  l!etula,  ia  a  thin,  almost  culor 
let*  fluid  with  a  iMiur  taste  aud  odur. 

Tn  tbp  operation  fur  gwtlric  RKiiIb  aa  iacision  is  iaad«  tbroavh  th«  abdominal  ^ 
wall*,  alonic  tbe  linta  alha.  the  •Ciiiaai^b  in  opvucd.  nnd  ihc  iip4  of  the  gaatrli 
uiiuud  Kvcurely  dhwii  in  tliuau  <i(  tUu  iiiditioa  io  the  alxbuiiiind  waIIh.     UiiUi 
Huoii  LaktiH  [iIhcc,  «o  Ibai  a  ii^rmancni  opi-nin);  Trvin  ilie  eiterior  into  iho  liiud*  i 
Oip  ■tomncb  is  Mlabliihrd.    A  tiibi.'  of  proper  c'ini>trui-iir>n,  inlroducvd  ai  the  limi 
of  Ihc  operation,  becumra  lirtiily  ■ccurvi!  in  pUci-  bv  Ibe  conlmciicm  of  bonling.^ 
liirougb  tbe  tub?  thi^  cuiiLeiiUof  the  ntuuiNcli  can  1i«  received,  and  ibc  niuMual 
menibfun«  sllinulaied  at  plesHiire. 

When  obiiiined  fniiii  a  natural  fistula  in  tiiau,  il«  »|>eeiliR  )(ravit,v  hat  li««u 
found  to  difl^r  little  I'nmi  that  of  vrai«r,  vuryin>:  frum  1. 001  bi  1.010.  aiid 
Ibi!  ■moiiMt  iif  solids  pn^cnt  tii  b«  ci)rre«ii<iii(HiiicIy  amall.  In  auiinalii  i>ur« 
giwtric  juice  Hcem.H  to  be  eijuativ  iMiur  lu  Molidei,  the  bij;h«r  Gi>liuiuta>  wbick 
~Ww  obvervcR'  lutvc  ubtained  l>eii)g  probably  due  to  admixture  iritli  food. 

Of  thv  Mnlid  matters  prt«mt  about  half  are  innrgiuiic  itnltN.  t'liicHy  nlkiilin^ 
(snditinO  chWidtv,  tvitli  xmall  igunntltiiv  uf  iihtHphntm.  Thr  cirtninii-  tiia- 
terial  coM«iM«  <>f  i)('}Hin,  a  bndv  In  Im-  dcvcnbei)  inimivliiilcly,  iniird  withj 
other  snlwtanciv  ul  uiidetcrnitni.-d  nature.  Iti  a  hcnllhy  ■t'iniacb  gastrir  juioa 
contains  a  v«ry  amall  (|iiiiiility  only  of  mucin,  unlcM  some  subniHsiTlary 
Miliva  has  been  swallowed. 

Tbe  reaction  is  disiinccly  acid,  and  the  acidity  is  normally  due  to  free 
liydfochliiric  acid.  This  is  shown  by  variouii  pronfa.  ainouj;  which  we  la^y 
mention  the  conclusive  fact  that  the  amount  uf  chlorine  prvaent  Id  ftastrie 
juioe  )t>  mure  tbau  would  atjflice  to  lurm  chlondra  with  nil  the  haaca  preaeot, 
ftiid  thut  the  cxceoB,  if  regarded  as  extHtiuK  in  the  form  uf  hydrcichloric  acid, 
cmm'sjHiiidH  exactly  to  the  <|uauiity  of  free  aci<l  pretent.  lactic  aud  butvric 
aiifl  iXhir  undii  when  present  are  teoondary  t>ro<luctH,  ari-iinft  either  by  liK-ir 
ratpcdivc  ferment Hlioii A  fmm  articlt^*  <>f  fu<><l.  nr  I'rom  the  ii«comp<Mtioii  uf 
tlwir  alkntinc  or  ctiber  mllH.  lu  man  tbi?  amount  of  free  hydrochloric  acid 
in  hfntihv  juice  may  Ih-  vtnteil  to  be  about  0.2  |)er  cent.,  but  In  aom«  nniinala 
it  ii^  i>r<ibiiblr  higher. 

^  202.  On  Marrh  gastric  juice  ban  no  amylolylii-  aclion :  nn  the  ennlniry, 
wbrn  B<divii  i#  mixeil  with  guHric  jnice  any  nmylolylic  fcrRwnt  which  may 
bo  prrocot  in  the  former  i*  at  onoc  prevenled  from  acting  by  iho  aeiilily  of 
tbe  nl)Xlur<^  Mons)vor  in  a  very  xburt  tima,  »p«cially  at  the  lemporaiiir* 
of  Ihc  IkkIv,  the  aiiiylolylic  lerinent  \f  dnttroyed  by  lli«  acid,  so  that  eren  oa 
neutral iiaii<Mi  tliv  mixliin.-  i»  unable  to  convert  starch  into  sugar. 

On  d«itroM  hcHltby  gn#tric  juice  has  no  clfoct.  Anil  its  power  of  invert- 
ing cane^ugar  seems  to  be  less  than  that  of  hydrochloric  acid  diluted  to  tlie 
eame  degree  of  acidity  as  itself.  Id  an  UDbcaltby  etomaoh.  however,  con- 
lainiDj;  much  mucus,  the  gastric  juice  is^rcry  active  in  converting  cane- 
BUjjar  into  dextrose.  This  power  seeoiB  to  be  due  to  the  jirvnence  in  the 
UUGua  of  a  apecial  feroKnl,  anato);nufl  to,  but  quite  didlinct  fr»m,  tbe 
IrtyaliD  of  ntira.  An  exceaaive  <{uanlity  of  ('ane-.iugar  iniruducol  into 
iIk  stODtKclt  CBUsee  a  aecrctiou  of  mucus,  u>d  heiK«  providat  for  its  nwo 
ccponnioD. 


ivl  fnv.      I  hougli  llicrc  )■  ps]x'ririK'n(nl  rviik-iK-c  ihiil  <:'mii liion  <>t  riiU  la  a  ; 
rrrtBin  rxtritt  liim  lirkr  |>]ii<ri.-  in  (ht-  filtfinncli.  ibi-  trrcnl  niHM  iil'  lht<  fnt  ftf  . 


kI  i*  iMit  Ml  changed. 

Siirh  luinernU  an  are  soluble  in  Tree  hydroi-liloric  aci<l  arc  fur  the  nicMt 
|af1  dlMolvvil :  ihriii^h  there  is  a  ditrerence  in  (hia  anil  it)  kiiiio  other  ro* 
ifMcIs  bMwef'D  ipiftrie  jiiico  and  »im|)l«  free  hydrochloric  acid  diluted  wilh 
«atrr  tit  tbe  ratne  de^i4«  of  ncidiiy  as  the  juice,  itie  praenee  either  of  ibo 
pv|«tii  nr  u(  (tllicr  Inidies  upiiareniiy  mMlilyiDg  the  solveut  action  of  tha 
■dd. 

The  r^wnlinl  [iroperty  of  gastric  juic«  b  tli«  power  of  diMolving  prot«id| 
maitm  and  of  o-nveriiii);  iIk-id  iiiln  a  suhMnni-e  ca)le<l  |)epli(ue. 

AHi»u  of  yuirif  JHtee  on  protfiih.     The  Kttullit  are  t«>euiially  the  Bame,.] 
wbellMr  natural  juico  obtainw  by  tn«aiiB  of  n  Halula  ur  ar(iticb)  juioe,  i.  e., 
ui  arid  inAtuoii  uf  the  tnumtis  nwniknn*  of  tlio  Nloniarh,  be  uned. 

ArtllMal  (Oniric  Juice  mij  be  prepared  Ed  luiy  of  Uie  followlni;  ways; 

I .  The  inuciiu-  incmhniiic  of  a  pig  •  i>r  ilos'«  (tomacli  u  rcBiored  tri.im  tho  ihur* 
ttilv  i-oal.  Siirtv-  uiiiicril.  rubbo>)  in  n  mnrtar  witb  pouiide<l  g\f  and  ritrHcio] 
with  aialer.  Tlie  aquniun  extract  tillered  nnd  •cidulati.-d  (it  U  in  itaclf  aomewhal 
B«ri<l).  unlil  it  hu  a  rr««  aciilliy  ourmfKiiiding  tu  i).'2  i<cr  cent,  uf  bytlrucbloric 
add.  niotaina  but  little  nf  the  producia  of  ili^caliou,  sucu  at  (H^jitone.  bat  is  Ikirly 
pMaaL 

S-  Tliv  aiuciiUH  Dirnibninc  nituiUrU-  prp|inrrd  mid  iniiu-ol  in  nllotrvd  todijmt 
■I  S6*  C.  ill  •  lance  >(uuiility  of  )iydrucliU>ric  uci-l  ditutcil  lu  11.2  |<i'r  c«nl.  The 
fnMer  port  «r  the  aicml-raiie  dl<Mp|)Oiiri-,  ^ircdn  only  being  Ivfl.  mid  tlie  soine- 
arhal  iifialfM-rtic  ll(|uid  ctiu  be  devanied  and  flttensl.  Tbe  filtrntt'  ba«  imwerful 
dJKiatlve  I  |>eiiiic)  iiroiiMtiM,  but  contains  a  tywsiderable  amount  ••(  ibn  jiroducta 
M  dlcnlloa  (pe|>totie.  tic.),  aruinx  from  tba  dig<«lian  of  tbs  niucoun  ntrmbmne 
tMrif.' 

3.  Tbi-  niiKiKm  iiictiibnirit',  .liinilurlr  pri'iiutc*!  and  mliiced,  b  thriMrn  ioU>  a 
mlB|<«rBtivFly  tar^c  iiunntity  uf  ccncetilniltH)  ^treeriii,  and  allowed  to  stand. 
The  nirwbntn*  may  w  prtvioudy  •U'hydriitfil  liy  Wng  iilliiwed  In  'tand  under 
alrriti'd.  bat  ihlit  ii*  not  necnwitr,  and  u  lo"  iirolonxod  action  nf  the  al«<ih<il  injures 
nr  rvpu  dniroy*  the  activity  ol'  tbe  ]>rDilut.-l.  The  dccuiilcl  cleat  Rlyoerin,  ill 
wbirb  a  COO) pa rn lively  sBiail  auaatity  of  (he  unliimry  jirMelda  of  the  mucous 
■Mtaibrane  are  dli^~-l<ed.  if  added  (u  hydrochloric  acid  of  0.2  per  cent,  (about 
I  r.c.  of  tbr  xt/ccrin  to  100  c.c-  of  the  dilut«  acid  are  Hifbficni),  makm  an 
arllfirlal  juici-  (iiierably  free  from  unlinary  pmtehU  luid  peptone,  nnd  of  rooiark- 
able  ["ileni-y.  the  iirmeoce  of  the  glycwrin  not  ioletfcriiig  «'ilb  Uie  reBiillM. 

Bi'f.'re  procectlin-;  to  xludy  the  action  of  );iu>tric  juice  on  proteid*.  it  will 
hr  iiM'fiil  to  n-vicH  very  hriclly  the  cliief  obaraclen  of  the  more  iuiporiaiiC 
iii<imtii-n  of  the  groups 

The  more  Inijioriaiit  proieida  wbich  we  linte  tbu>  far  studies)  aret  I.  Ft- 
hrin.  itiiiolubte  in  Hiilcr  and  nut  reully  w>tuble  i  ■'.  r.,  without  clnuiKc)  iusnliita 
•oluii'inn.  'i.  Mynnn,  insoluble  in  niil^r  bui  MiUiblo  in  «liiw  «iiKit>n<i#,  tifi>> 
v]d«l  ihnp  are  not  loo  dilute  iir  trio  coniiiitmied.  3.  Olohulin  (Incliidiiig 
pKrak'lobiiliD,  librini^tn.etc...  inudiiblc  in  «ali-r,  hut  rondily  mdiihlo  in  evca 
vrry  diUiir  valine  Mibitionii.  4.  AHiu>nin,tfr\im-all/utniH,»n\iiMti  in  water 
in  tW  ab«rncr  of  nil  ra\\r.  •>.  Aciti-ulliumin,  i»tii  nhicb  vlohulin*  and 
mrriMn  arc  npidir  ronvi-rtrd  l>y  (he  action  of  dilute  acidii,  llie  [nirtii-iilar 
ami  albumin  into  uhich  ilir  niyirin  of  riukIi.'  in  ohaiigtd,  Ix-iii^  cimriiinM 
railed  'y'cNin-  If  tlir  rmirciil  UK'd  be  not  dilute  acid  hut  diliilo  alltall 
th>  prt:<tuct  i»  called  nlknli-nlhumin.     Tbe  tno  twdics,  nc  id -id  bum  in  and 


I 


Invvm.  aw)  l«  tenoTed  tif  rcnnntnUnn  *l  N*  C  Mrf  MlbivtiwviH  liluittt 


J 


TI1K   TtRSirifl    ATfD    MBCRAKtSMfl   Or   DldlilTIO!?. 


slIutlialbuaiiD.  are  very  parallel  ia  ibeir  clinraL-t«rd,  and  may  readily  be 
ooQverleil,  the  one  into  ine  otbcr,  by  the  u^e  of  dilute  alkali  or  dilute  and 
nMI>edively.  Their  moat  importaot  common  uharoolersare  iowlubilily  in 
WAtAT  and  iu  saline  aolutioos  and  ready  solubility  in  dilute  ncida  and 
alkaliea.  6.  CongulUed  prateidn.  PiS  we  have  teen,  wbcii  fibrin  suKpeiided 
in  water,  scrum -albuniiR  in  noliilion,  tirid -albumin  ur  alkali-albumin  fir«> 
peiulo'l  in  watvr,  or  para^lobiilin  »U4|>t.-nded  in  irater  nr  diMtilvtid  in  a  dilute 
ml  ine  solution,  ore  hmtvd  l4>  n  li^mjierature  ivfaich  for  the  whole  group  may 
b"*  put  down  at  ubnnt  "■'>'  to  Si)"  C,  each  of  them  bcuomiM  coagulatnj,  and 
after  tbe  chnu^-  i«  in*(i]uble  in  water,  saliue  solution*,  dilute  acids,  Mc  iftj 
fact  iu  everything  but  very  strong  acids.  Myosin  and  libriuogvn  undergo  ft| 
similar  change  at  a  lower  t«mpernture,  vix.,  about  -^li"  C.  We  may.  for 
prasMit  purposM,  spojik  of  all  these  proteid*  thus  changed  under  the  one 
lem  of  coagulated  proloid^. 

To  the  above  list  ne  may  now  add  two  other  proteids,  vix  :  7.  A  kind  of 
albumin  which  forms  tbe  gr«at  bulk  of  the  pruteid  matter  prewnt  in  r.iw 
"  while  of  egff,"  and  which,  since  it  differs  in  minor  character«  from  the  albu- 
min of  blood  and  of  the  tisfues,  ia  called  i'jy-alhii'nm,  H.  The  pwuliftr  pfo^ 
teid  eaiein,  an  importaut  conslitnent  of  milk.  This  may  perhaps  be  refardedl 
as  a  naturally  oocurriuK  alkali-albumin  nince  it  hiu  many  resembUncea  to 
the  ai'tilieial  alkali-albumiu ;  but  for  several  reasons  it  is  desirable  to  consider 
it  a.t  an  iude|iendi.-nl  body. 

Eg;;-albumiu  like  serum -a  I  bu  rain  becomci  coagulated  at  a  temperature  of 
about  7o°  u>  SO"*  C,  and  though  eas^D  as  it  uaiurallj  esiais  in  milk  is 
not  coagulated  on  boiling,  whun  iieparated  out  in  a  special  way.  andiiuspended 
in  *water  in  which  it  i*  insoluble,  it  becomes  ooagulatett  at  about  I'l"  to 
80' C, 

It  will  b«  observed  thai  all  these  proteids  form,  as  regards  their  solubilt- 
ties,  a  dwoondiiig  series  in  the  tbllowing  order:  cmtgulated  proteids;  librin  ; 
acid'albumin  wilh  alknli-albumin,  nnd  casein:  myofliu,  globulint;  eeram- 
albumin  with  egg-nlbumin. 

We  must  now  return  to  the  action  of  gastric  juice. 

If  a  few  shreds  of  (ibriii,  obtained  by  whippin;;  blood,  after  being  thor-  I 
oughly  washed  aud  boiled  and  thus  by  the  boiling  coagulated,  bethrono  \ 
intoaquanlity  of  gastric  juice,  and  the  mixture  be  espoied  to  a  temperaiure 
of  tnm  35°  to  &"  C.  the  fibrin  will  speedily,  in  some  coses  in  a  few 
minutes,  be  disaolred.  The  shreds  firxt  swell  up  and  become  transparent, 
tlicn  gradually  dissolve,  and  finally  disappear  with  the  exception  of  some 
granular  dL-bn:*.  the  amount  of  which,  though  generally  small,  varies  accord- 
ing to  circumstuuoes.  If  raw,  that  is,  unboiled,  uncoagulHte<l  tibrin  l>e 
employed  (be  ssune  cliangea  may  be  otuwrveil,  but  they  take  ])lace  much 
more  rapidly. 

If  small  raonds  of  coagulated  albumin,  such  as  white  of  cvg,  be  tmted 
in  tbo  same  way,  the  same  solution  is  obserted.  The  piece*  uecom'^  trans- 
partinl  at  their  surfnoes:  this  i^  ejtjxtcially  seun  at  th(>  edgft*.  which  gradually 
iMOone  rounded  down ;  and  solution  «teiulily  progru&tes  from  the  oubtido  of 
Uie  lueca  inward. 

If  any  other  form  of  coagulaU-jl  nlbumiu  {.e.g.,  precipitated  acid-  or  alkali- 
albumin,  suspended  in  water  aud  boilvdj  be  treated  iu  the  same  way,  a  simi- 
lar solution  tJJtoa  dImc.    The  readiitess  with  which  the  sDlutiuu  is  etfeoted,  J 
will  depend,  «et«ru  parihtu,  on  tbe  amollncis  of  the  pieces,  or  rather  on  the  1 
amount  of  surface  as  compared  with  bulk,  which  is  prewuted  to  tbe  actJon 
of  the  juioe. 

Oastrie  juioe  then  readily  dissolves  conguUted  proteids,  which  ntherwiee  I 
■re  insoluble,  or  soluble  only,  anl  that  with  didiculty,  iu  very  strong  acids.    ' 


wnior  or  in  diliil* 
with  gMlrii:  jiitn*.  no  visiljlr  (.'himgo  inkaf  |)liu^v;  tnit  nt-vcrlht'lum.  it  it 
oo  «zai»inBl»<>ii  tliitl  ilip  aoluttoo*  linve  umliT^oiK'  n  rrmurknlile  cti«n^,  iha 
•Blon  ><r  ntii';))  i»  oti>il.r  seen  bv  otnl nmtiiig  H  with  lh<r  chim^'c  cHV-clcd  by 
diluii-  mil)  bIoiic.  If  raw  nliiic  of  egg.  lurgcly  (liliiieil  wiili  nnter  nnd 
•tniiiKi).  tw  ireiilMl  with  n  <utlicienl  '(uaniitj'  ol'ililutv  Imlrochloric  nciil,  the 
uiMlnt-piKxi  or  liirbi'liiy  whicl)  a[)|>enn?d  in  the  whit«  of  egg  on  liilulioii  (nnd 
Which  t±  due  tu  the  prvnjuuitiiio  of  variouH  forme  of  globulin  accompanying 
ihv  ei^-albuinin  in  the  raw  white)  ditappearB,  and  a  clear  mislur«  rcsulta. 
If  a  {Mrtioii  of  the  mixture  be  at  once  noiled.  a  larj*e  dep'nit  of  coagulated 
albumin  occurs.  If,  liowe^'er,  the  mixture  be  expoaed  to  5(1^  to  56'  0. 
tot  9om«  time,  tlie  aniouui  of  coaKulatJoii  which  in  produced  by  bmlin^  a 
•Mriniea  bveoiuM  leMi,  and.  fiually.  builin;;  products  no  col^■ulalion  wbaUver. 
By  Ofutraliitiition,  however,  iliu  wh»lu  of  the  albumin  (with  such  reMrictiuos 
a*  the  preveooc  of  certain  neutml  »alt«  mar  cnuiie}  may  be  obtained  in  th« 
(ana  of  Acid>albuni!n,  the  filtrati:  alV-r  nvutraliiiution  containing  no  ]irut«i(b 
M  all  (of  a  ref}-  small  quantity^.  Thii*  thu  wbolo  of  the  albumin  urKwnt 
in  the  whiltf  oJ'vgK  i^ay  be.  in  time,  conrurteil.  by  the  nimplv  ncliou  nf  diiiit« 
hydracbloric  ncxl.  into  ai'id-albumln.  S^ruiii-alfaumin  nimilarly  trejitod 
UMletvocs,  in  eourtv  of  time  a  »imiliir  rntivernion  into  ncidaltnimiii.  and  we 
lwT«  luraaity  M<en  (ji  o9 1  that  volution*  of  mro^io  or  of  any  of  thi;  globulins 
an)  vriili  rrmnrkablp  rapidity  con\Mrlcil  into  ncid-albuniin.  Thu«  ciinple 
dilute  bydrochloHr  of  the  aame  dirgrrv  of  nciility  at  gastric  juice,  merely 
coDvvrtB  ibeae  pnM«i<ls  into  acM'Slbiimin.  Ilie  rapidity  of  the  cbanga  diflsi^ 
iog  with  the  diflEtreot  proteide,  being  in  some  crm«  very  elow,  and  requiring 
»  relatively  high  tem{)eratuiT. 

If  the  awe  white  of  egs  or  serum-albumin  be  Ireate'l  with  gastric  juic« 
hmfwd  "f  simple  dilute  hydrochloric  acid,  the  events  for  some  time  socm  tbo 
aaaic.    Tbu»  after  a  while  boiling  cuumm  i>(>  ciMgulatiou,  wbile  neulralixation 
pn»  a  cMuiderablc  precipitate  of  a  protad  bodv,  which,  being  insoluble  in 
waUr  and  in  todium  clili>nde  »olutiiiii.^  and  Mluble  in  dilute  alkali  and  acids,  _ 
ai  leaK  cIomIy  nwmbW  acid-albumin.     Etut  it  u  found  that  only  a  ponioaB 
of  ihe  pnicid  originally  prmcnt  in  the  white  of  egg  or  »erum  albumin  can  ' 
tkna  be  n^iwl  by  pn-cipitnlion.    Though  thv  neniralluilion  he  i-arriud  out 
irttli  Um  graateit  care  it  will  be  found,  on  Rltering  off  the  neutralixation  pre- 


cifMtAt^  (nat  i«.  ibe  actd-nlbumin,  ihnt  thv  tiltratc,  a*«bown  on  cmplnying 
Um  Tariqu?  teets  for  prolcid  (mo  ^  !■>)  or  on  ailding  an  adciuatu  i^uaiitity  oT^ 
MinO|f  alcohol.  Mill  contains  a  very  considerable  quantity  of  pMttud  matter  ;f 


^       tinri 
■     cha 


and,  un  the  whole.  iIm.-  lunger  tbr  digestion  is  carried  on.  tbc  grraK-r  u  the 
pro|>>irti"n  buriH-  by  ihc  proteid  remaining  in  solution  to  tJie  prm^iiiitatu 
ibrown  down  oii  neulralizntion  ;  indeed,  in  some  cnscfl  at  all  events,  all  tite 
(uiileid  maltcr  ori^'iniilly  present  remains  in  solution,  nnd  there  is  no  nMi< 
iratitation  orecipilulion  at  all,  or  at  ntiMl  a  wholly  ioMguilicant  one 

$  203.  1  he  proietil  matter.  thu«  remaining'  in  <4ilulion  after  ne^ilralixnltoa, 
diflbti  from  all  the  proteids  wbich  we  have  hitherto  studied  in  a^  mncli  as, 
Uiourb  exiitinjt  in  a  i>eutral  solution,  ii  h  not  coagulated  by  hest,  like  the 
effg-<lbiimio  or  serum-albumiu  from  which  it  hts  l)««n  produced :  tbo  solu- 
tinri,  after  the  iieutratiiaiion  precipituie  hiu  been  fillers)  oir.  remains  quite 
char  when  )M>il«d.  The  only  other  noluiiivna  of  protei^b  which  do  nirt  ooagu- 
~  itr  on  boiling  are  Aolutiuun  of  aciil-  ur  alkali-albumin ;  but  these  aolulious 
iiu>i  Ix-  acid  or  alkali  rMjieetively  :  the  acid-albumin  or  alkalt-albumin  ta 
'fatoluble  in  a  nnitral  uilutiuii,  and  when  niintdr  tiuii{>euded  in  water  it 
raadily  eoagulntc*)  at  a  tcmjivfnlur^-  of  7V  ('.  Thu  new  pr^iteiil  matter  of 
which  are  arc  viieNkiDg  is  •■>luble  in  neutnl  tolutiouji.  indeed,  iu  diMilled 
water,  nod  vn  under  no  circuOMUnew  be  oongulalvd  by  heat. 


312        TUB   Tissues   AKii    MECUAMSUS  Uf   UIQKSTIUX. 


H  VpoD  ^xHininslion  we  find  that  ttie  netr  protoid  ii>Mler  tUua  left  in  anlu- 
Hon  ciJiifii^E  uf  Hi  k«Bt  two  iMsiincppruteKl  binliEit.  Iflo  tli«  aolulinn  ainino- 
■  niuiii  sul|ihHle  be  ui!i|«il,  pari  of  iho  ]in)tci()  luaUer  U  precipituted  while  i«rt 
is  lilill  Itlt  ill  eoluiioii.  Tiie  prot«iil  litidy  tlitia  tliruMu  dnwa  is  called  a/fru-  ' 
vine  (ttiere  are  several  varielica  ol'  albunune  but  them-  ut-L-d  not  aavt  ili-tniii 
na).  It  iipproacliea  albumin  ia  nature  by  n-VAoii  nf  th>-  Inci  tbai  ii  will  tint 
diflbfte  ibmuKb  meiubraues ;  tbiit  it  ilitrt-r«  hunuvcr  widely  fmm  that  pmirid 
is  .hUcjWU  by  it»  nolulioitit  uol  cimxulaiiiig  on  builiiij;.  Thi-  boiiy  wbicli  i*  not 
thnmn  down  by  »fiini<iiiiimi  .Mdphalu  ia  culled  wjAunf;  it  ililliTt  (rmii  allHi- 
DKiM'  iu  beiiif(  clilliiKiblr,  fur  it  ndl  iiiisii  tlirnugli  iiii'ii)braiK'«.  Tin*  dill'iitiiin 
is  not  iicorly  Ml  rapid  nii  ibiil  nf  ■nliii.  HUgar,  aad  olht'r  nimilnr  imltrtAiice^  : 
indwd  vobitioDN  uf  |ii:|)|iiniii  niiiy  lie  In^'d  from  nilU  by  dialysis.  But  it  in 
very  ninrk<-<I  ak  cnnipan-il  witb  ihaC  of  other  proU-idn;  tbo»p  pan  tlirouph 
ni«ndinuic«  wiih  the  ^mu-:<l  dillieiilty,  if  at  nil.  I'eplone  i«  in«ulubl<>  in 
slevbol.  and  may  Iw  prei-i piloted  Ihim  il«  lobilioiin  by  tJie  «d<litiwi  of  un 
fltkiiiiaii'  i)iinnlity  of  (hi«  mgcnt;  but  for  tlii»  purpoM  a  wty  lur^  excess 
ofnlcoliol  IS  needed,  utherwixp  niui-h  of  the  peploiie  remains  in  solution.  It 
may  W  kept  undor  aleobol  lor  n  Ion);  time  wiihoui  underf>oin)r  cbange. 
wberms  olher  pr»(eitfs  are  moro  or  Uh  slowly  eiMi}>uhited  by  alcohol.  A 
UBcfiil  l»t  lor  peptone  is  furnisheti  by  the  I'ncl  tbnt  a  solulion  uf  p«pt«n«. 
mixed  nilh  a  slroii];  snlulioD  of  caustic  iKilush,  jjives  on  nddilion  iiT  a  mere 
Iraco  ol'  eupric  sulpbatc  in  lb(>  cold  a  pink  eulor,  wherctis  other  proteiib  give 
a  vioUt  color.  Id  iipplvin^;  tbis  leel,  liowever.  cure  must  be  laken  not  to  add 
loo  much  ciiprio  wilpliaie  MUce  in  ibat  case  a  violel  color,  deepening  oo 
boiling,  tbnt  is.  the  ordinary  proteid  reacliou  (see  §  15),  is  obtained. 

Thei'e  are  cvasoiis  lor  ihinkiii);  llial  ihere  are  several  kinds  or  at  learil; 
more  than  one  kind  of  peptone:  but  "e  may  for  ibe  presenl  re>,iird  ihe  sul>> 
stance  as  one.  For  a  \ua^  time  albumnae  was  confounded  with  |>(.'p(oiK',  and 
many  of  tbc  coninicrrial  formn  of  '*  pcpIuQC"  nmiiiiit  Inr^ly  ot  allHimiiM>: 
indeed,  thu  two  arc  clowly  nllicil  and  havfl  many  n^iictions  in  common,  iliu 
mu«l  ulrikiiiK:  diffen-nce*  being  that  jie|>ton«  b  difrtis^ible,  while  albuimiw  to 
not.  or  hanlly  at  all,  and  that.  |)epl'>np  is  not  liki-  albnnic^e  precipitated  by  . 
amiDuniuin  sulphalc.  The  nmoiiiit  uf  albumiwo  np|K-nrine  in  a  dij^estion 
ttxperimeiil,  relative  to  ibo  amount  of  true  peptone,  denends  on  the  lu-tivitr 
of  the  juice,  and  other  circunislAnees.  Wo  may  regard  albumow  as  a  leas 
oomplcle  product  of  digestion  than  peptone. 

liw  precipitate  thronn  down  by  neutraliintioD  after  the  action  of  gnslrio 
juice  on  egg-  or  senini  albiiniin  resemble,  in  its  general  characters,  acid- 
albumin.  I^ince,  however,  it  ))rc<bah1y  is  distinguishable  from  tbe  body  or 
hu<iiefi  jiTodneed  by  the  ncliuu  of  simple  acid  on  muscle  or  white  of  ej^g;,  it  la 
bcsi  to  reserve  for  it  tbe  name  of  fiarapi^Ume,  which  was  originally  applied 
to  it. 

Tbun  the  dii^'t^iion  by  gastric  juice  of  solutions  of  e^j^albumin  or  serum- 
albiimin  rt-sulU  in  theoinveraioD  of  all  tbe  proleids  present  into  jie{>tone. 
alhumoie  and  narafieplunc,  of  iibich  the  tinit  mav  he  considtirtMl  as  tbe  final 
and  chief  pro'liK't,  and  the  other  Inn  tL*  iuiermeuiBle  prodiiet?.  ooeurring  in 
varying  iiuantitv,  |i<in<iblv  not  nlwayx  fori]i<<<l.  and  [indwbly  uf  (ccvimlarr 
im|Hiitan<'e.  wIm'H  librin,  either  raw  or  Ixiilcd,  »r  any  form  of  coagulated 
proteid  is  itiwolved  himI  seems  to  d!sap|H-ar  under  the  intlnenct-  of  gaalrio 
juice,  the  same  products,  peptone,  iilwimiwe,  and  |Mini|>e[>tone  make  their 
ap[N.-amncc.  The  same  biMlice  result  when  myosin  or  any  of  the  globulin* 
are  subjected  to  the  action  of  the  juice  :  and  acid-albumiii  or  alkalialbumiii  is 
similarly  converted  into  albumow  and  peptone. 

It  is  obvious  that  the  edect  of  the  action  of  tlw  gastric  juiee  is  U>  ohango 
the  Ins  soluble  prolcifl  into  a  more  soluble  form,  the  eluinge  lH:tng  either 


SALIVA    Ah'U  OAATBIC  JCICE. 


818 


CDiuiiWinl  U[>  lo  ili«  ixaev  of  miioik.  tite  ni'isl  sululilc  (if  all  pruteKls,  or 
hnoK  It-n  in  [Hin  tnc»<n|>l«li>.  Tliia  will  life  smn  from  ilio  fdljowinf;  tnlwlar 
mmiijnrtiirui  iif  [tniteiili  nocordiiift  to  tbeir  MilutiilUiiM. 


titinih  •!•  dUlUM  iraltr. 

AintK-u*  •nlutton*  DOt  cja^Uted  on  boiling : 

I'  P*i>lon». 

^  'ilo AlUuiDMe. 

AfUfiBi  »'<iuiion*ctiaguUted  on  builliig  .  dlliuDiin. 

InKiliihl/  in  tliilUM  teller. 

ttfittf  wlable  In  ilUuie  saline  mitutiotio  (NaCI  t 
Mrnrnt.) Globulins. 

Solnbl*  (Milv  in  sUonger  ■•lino  wiUitiim*  (XaCI  H 

lu  10  p«r  MtiL) Mymii). 

ItuolfAU  in  itilnit  m/inr  toliifkmt. 

Rwdity  mttilite  li.  dilute  -eid  (IICl  0.1  per  «•«.)     ]  JfJli"";!!^!"; 

'"'*"''■"''' ■        •      jOMcin. 

t^>lulilF  with  <lifllcultj  lu  (lihil«  add,  ibal  is  at 

bicb  Ifioprrntur*  (UO^C)  Mtid  iift4>r  prolongrd 

trrUinviil  'inly Fibrin. 

Inviluhlc  In  dilute  adds,  ttfilublff  only  In   Mmng 

Hiila Coafulattd  |>tnU-i4l. 

Milk  «Wn  tnvtv<l  with  gnriric  juice  Ia  Am  nf  ull  "mnJIeil."  Tliis  is  the 
Trmill  pnrtiv  nl'  llir  ni-tii>ii  of  lliv  tt^c  ai-lil  but  rhirtly  af  the  *|>erial  nctioo 
»f  H  particiilnr  oii^liUivDl  of  pi»lric  juiiv,  of  which  w«  ■hull  ■•(x-itk  her»- 
afbr.  Tbr  run)  c(itiflisl#nfHfinrticuliirj>r<)(4.'iilmntlvrmixeil  with  till ;  iiikI  tbbi 

IpfTitriti  Buitter  a  Mibtoiuenily  diMolvti)  wiih  lh«  Mine  nppMiranco  of  pi-p- 
Incir,  allMinoae  and  iMrapeplone  aa  in  ibi?  nw  of  other  nMtciilB.  In  favt.lhe 
di|t«9tiiin  by  icutric  juice  of  all  tl»  vaHolica  of  protd<l«  c^irsmU  in  lliv  con- 
vvnion  of  ihv  |>ni<«t<l  iolo  peptoo*.  with  the  cimoiniitanl  np|>caranc<.'  of  K 
certain  rariahh-  amount  of  albuMnwe  and  nnra|>eplone. 
tS04.  Cireiimtiiinfri  nfffHinif  e/iulrif  'li'jffiioiu  The  aulvenl  action  of 
OMric  jiiit«  on  proteitU  ia  inmlifi^l  hr  a  vari«tv  of  circumstan (.■«■».  Th4 
■Uun*  of  th«  prolrid  llMlf  raukcn  a  (lid«ren<«.  tliou^h  thid  in  tk-trrmincd 
profanbly  by  phyiiical  rath«-  than  by  cheuiit-al  characters.  Hence  in  mak* 
hig  ■  arriM  of  cuniparalive  triab  tiic  aauK^  pruiett)  uhouUI  be  U*eii.  anil  tb« 
fcrm  of  prolciil  mo*l  o>fivctiiL-nt  for  the  pur|KW  Ja  fibrin.  If  it  be  dcairrcl 
■linply  t«  aca-rlaJn  nhcihrr  anr  giviin  iifMx-iinen  has  *ay  digealtve  |xmer»  at 
alt,  it  ia  Initt  to  iw  lH>il<fl  fibriu,  ainoc  rati'  fibrin  in  weutually  Oiiuulvcd  by 
tlilule  hyilrtwhlorit-  arid  nl<>n«,  prohnlily  on  ucfiuiit  of  vouiv  |ie|>?iu  pre- 
vboalj  pimai  in  thr  IiIixhI   Iwonniinic  eutauKkil   with   tbe  fibrin  during 

PelMtinic-  Bui  in  <.-alimalin^  'luaiilitalively  thu  jicplic  power  of  two  tiieci- 
ntw  of  euirii.-  jui<v  nnder  dirti'^-nt  coniliiliHu.  niw  Rbrin  preparen  by 
ffniunrr'i  nsHhuil  ia  niD«l  coiivviiionL 
Ptirtimwuf  wrll-narbcd  fibrin  arc  atainwl  with  camlne  and  wtaln  waahed  to 
ranofC  ibe  >uii»llii<>ii*  coIaHuc  niatlt'r.  A  fraEini-tit  bt  lhl>  culorcd  Ahrin  thrown 
^^  lotu  an  acli^e  juie*  on  beo-niini;  dln"olvo>l,  tivni  up  ll«  cilur  lo  'hi-  fluid. 
^H  Hcm^  if  Ihr  iiHdti-  atiirk  <i(  coturod  fibrin  Im-  uofiI  In  n  M'Hirs  of  cxprriini-tii-.  and 
^f  tb«  aamr  bulk*  <i{  fibrin  and  of  fluid  be  urcI  in  «iai'b  case,  the  amount  «r  ilbrin 
^^  itWdtpil  Biay  bi>  fairly  nlloiatcd  if  tbe  dGnth  nf  lint  ^iven  to  tlie  fiuld.  Kilitla 
tbti*  cnlfltFd  wiih  carniitic  may  be  i>re*«rveii  in  eiber. 


814        THK   Tissues   XSt>    USORANIStfS   OP  DIOESTIOS'. 


Cilice,  if  suflicieiil  time  be  allovrei),  even  &  emnll  '(Uantitr  of  giu^tHc  juice 
irill  (liiwulve  at  lenat  n  very  large  it'  Dot  an  iiidelinite  ijtiaiiliiy  of  dbrin,  we 
aiv  kiJ  Ic  iiike,  af  a  measure  of  tlie  aclivily  of  a  epeciniea  of  -gastric  juice, 
not  the  iiiiaatiLv  of  fibriu  which  it  will  ultiniateW  uiaM>lTe,  but  the  rapiditj 
with  which  it  tliasolves  a  giveD  quantity. 

The  t;reater  the  surface  presented  to  the  nctioD  of  the  juice,  the  more 
rapid  the  anhitioo ;  hence  minute  division  and  constant  movement  favor  digee- 
tiun.  And  this  iit  prohably,  in  part  nt  leaat,  the  readon  why  a  fraRmeot  of 
sfiuu^v  lUameotout  fibrin  i^  more  readily  di.iaolved  than  a  solid  clump  of 
bdiliKl  white  of  egK  of  the  earae  aiie.  Neutralization  of  the  juice  wholly 
arrets  digf«tiun ;  fibrin  may  be  »ul>iuitt«d  for  an  almost  indefinite  linie  to 
Ihc  action  uf  neiitnOized  gastric  juice  witliDiil  being  dig«*ted.  If  lJ>e  neu- 
tnUiiuid  juioe  be  properly  acidified,  it  may  a^ain  becomr  antire;  when  }ifi»- 
trie  juioe,  however,  Iiaa  been  made  alkaline,  and  kept  for  «iimc  time  at  a 
temperature  of  35°,  ita  solreiil  jiowen  are  not  only  nuKiieDded  but  actually 
dettrovcd.  DigMtiun  in  miwl  ra|iid  with  dilute  hydrochloric  aciil  of  0.'2  {le^ 
rent,  (ilie  acidity  of  nntuni]  i^iutric  juicii).  If  the  Juice  cotitnins  much  more 
or  much  lew  free  acid  than  thU,  iu  activity  in  distinctly  impaired.  Other 
iicidi>,  lactic,  phwph  one,  etc,  may  be  sulwl  I  tutted  for  hydrochloric ;  but  (hey 
are  not  so  fiDwtual,  and  the  dcgn^c  uf  acidity  most  useful  varies  with  the 
ditTcreiit  acids.  The  presence  of  neutral  lalta,  »uch  lis  sodium  chlimdi-,  in 
exocsi  is  injurious.  Tne  action  of  inuniniiilinn  gantric  juice  is  most  rapid  at 
8A''-40"C.  :at  the  ordinan'  temperature  it  is  much  slower,  and  at  about 
V  0.  ceases  altogether.  Tiie  juice  may  be  kept,  however,  at  0^  C.  for  an 
indefinite  period  without  injury  to  its  powere.  The  gastric  juice  of  cold- 
blooded vertebrates  is  relntively  more  active  at  low  temperatures  than  that 
of  warm-blooded  mammals  or  birds. 

At  temperatures  much  above  40°  or  45°  the  action  of  the  juice  is  im- 
paired. By  boiling  for  a  few  minutes  the  activity  of  the  most  powerful 
juice  is  irrevocably  detitroyed.  The  presence  in  a  ooueentratetl  form  uf  the 
pri'ilucts  of  diici^iiuu  liiniters  the  process  of  solution.  If  a  large  (Quantity 
of  Hbrin  be  placed  in  a  .imall  iiuauiity  uf  juice,  diguMtion  is  soun  arrc»t«d ; 
on  dilutlun  with  the  normal  hyiirochloric  acid  (l).2  per  ceuL),  or  if  the  roil- 
ture  l>e  submitted  to  dialvftfi  to  retuuve  the  |tcpt<in«s  formed,  ami  iti>  acidity 
be  kept  up  to  the  normal,  the  action  rciwminenccs.  By  removing  the  pro- 
duciM  of  aigntioD  as  last  u  tbcy  are  formed,  and  bv  keeping  the  acidity  up 
to  the  normal,  a  av<ia  amount  uf  gastric  juice  mav  he  made  to  digest  a  wry 
large  quantity  of  protdd  mRt«rifil.  Whether  llic  qusutity  is  really  un- 
limited it  dtspiitcd  :  hut  in  any  case  the  energies  of  the  Jui(.-e  are  not  rapidly 
exhausted  by  the  act  of  digcjlion. 

$205.  yalinr  of  llic  artion.  All  these  fncts  go  to  show  that  the  digestive 
action  of  gastric  juice  on  proteids,  like  that  of  saliva  on  starch,  is  a  ferment- 
action  ;  in  other  words,  that  the  solvent  action  of  gastric  juice  is  eestiitially 
due  to  the  presence  in  it  of  a  ferment-body.  To  this  ferment-botly,  whiL-Ii 
IIS  yet  has  been  only  approximately  isolated,  the  name  oi'peptinaaa  been 
given.  It  is  present  not  only  in  gastric  juice  but  also  in  the  tthuidi  of  the 
gastric  mucous  membrane,  especially  in  certain  parts  and  under  certain 
conditions  which  we  shall  study  presently.  The  ulyi^erin  extract  of  gawtric 
tnucous  membrane,  at  any  role  of  that  which  has  bt:en  dehydrated,  contain* 
a  minimal  <|uantity  of  proleid  matter,  and  yet  is  itjtemely  peptic.  Other 
methods,  such  as  the  elubonite  one  of  Brin-ke,  give  u*  a  mnlerial  which, 
though  contaiaing  nitrogen,  exbibiij  nune  of  the  ordiuttry  pmtcid  reactions, 
and  yet  in  concert  with  normnl  dilute  hvdrorhluric  ncid  ix  peptic  in  n  very 
high  degree.  We  itcein,  tht-Ti-forc,  jiiitlbed  in  iMwrting  that  pepsin  is  not  a 
proteid,  but  it  wutild  Ixi  Imxantuus  tt>  make  any  dogmatic  statement  con- 


3ALirA    AND  GASTRIC  JUICE. 


815 


I 


ilngflBHBwicii',  olftalned  in  an  tauM  m  (|iiaDtilT  nt  a  limo  chat  iu  cxsct 
eitmuiait  AttlMtn  ItaTv  npt  yet  Ih-mi  a>M?i?riniiii?il.  At  prewot  the  luxiiirea- 
Utioct  of  pcfitic  powcn  in  nur  ouly  mIV-  tral  »f  the  pr«wnc«  of  pep*in. 

In  (HM-  iruportnjil  m>p<-ct  prp«in,  ilic  tprmciit  ol'  gMtric  Juice,  didera  from 
|it_\uliu.  ilir  fi-nwitl  <ii'  wiliv*.  J'nliva  it  active  in  h  pert'eotly  oeuiral 
■nMltijtu,  nnd  there  vvrmt  to  \jv  iiv  epocinl  cotiiiectiun  beLweeo  llie  ferment 
Mill  any  alkali  ur  ndil.  In  gutric  juice,  however,  there  is  n  nrouj;  lie  be> 
t«fHi  !!»■  Brill  an'l  the  ferment.  »<>  ttnag  thai  some  wriien  apeak  <it  peiisin 
■nd  hyilrurhluric  nciil  »;•  forming  togelner  a  compound,  pepto-hydroL'hforic 
>od. 

Id  the  alMenoo  of  exact  knowled)^  of  the  conittitution  of  proieidi,  we 
^iiiiil  state  tltstinctly  what  is  the  precise  nature  of  ibe  ehan)^  into  pep- 
tooe;  ibo  vanou^  proieMk  difler  from  each  other  in  elemeiitan*  compuaitioD 
•laHe  u  widely  as  does  pe|>ione  from  any  of  tbein.  Jurl^ng  ftom  tlie 
MMlofEy  with  tbe  action  of  saliva  on  etarch,  we  may  fairly  ituppoie  that  the 
ptwcMi  ia  al  bottom  one  of  hydration ;  and  this  view  i-.  further  nuggetiod  by 
llw  fact  thai  peptone  closely  resembling,  if  not  identical  with,  thai  obtniii«d 
by  putric  <lixi«tioo.  may  be  obtained  hy  t)i«  artiitii  of  the  xtroug  acii)*,  by 
tM  pniloDf^  action  of  dilute  ttt-id*  eK[)eria]ly  at  a  high  tcinperaiiin',  ur 
•imply  Etr  aigcMioD  with  super- heactsl  waivr  in  n  Pai>iii's  digester,  that  is  to 
say  hr  hmoik  of  a^nt«  which,  in  other  com*  ]>r<Klu<«  thoir  eSccIa  by  brine- 
it^  abnut  bydrolyttc  changea ;  beyond  tht«  we  cnniiot  nt  presoJil  go.  Vr* 
nay  idd,  however,  as  supiHirtiujc  the  t>ame  view,  the  statement  of  flom* 
obaarvin  that  peptone  when  In-aml  wilh  dehydrating  agents  or  when  sim- 
ply boaud  to  I4ir-170'  ('.  ix  in  [lOTt  rt'oonvcrlcil  into  n  body  or  bodies  re- 
Mnbling  acid  albumin  or  globulin. 

i  806.  All  proicid;',  sn  iar  as  we  know,  are  eoovorted  by  pcpin  into  pep* 
IMM.  CocHerainK  the  action  of  ^i^ric  juice  on  otiier  nitnigenoua  sub- 
■r«am  more  or  leas  allied  to  proteidd  hut  not  imty  piuteid  in  nature  our 
kaowledge  is  at  prenent  imperfect.  Mucin,  nuclein,  and  the  cbemieal  boaia 
of  bomy  liKVee  are  wholly  uuafTected  by  ^a^tric  juice.  The  gelatiniferona 
lisaues  are  dissolved  by  it;  and  the  bundles  and  mem b nines  of  connective 
tiaue  are  very  speedily  so  far  aSected  by  ii.  that  at  a  verr  early  xtoge  of 
4i|ntioa.  the  lyundles  and  elementary  fibret  of  U)uscle<  wfiK^b  are  hound 
laystfaer  br  coiineotivi;?  tiMuefall  aitunder;  moreover,  both  pnijuirvd  gehilio 
•od  U)«  gMaiinUerous  bagia  of  connective  tissue  in  lis  natural  condition,  that 
ii  wflbout  being  pr«r1ously  heated  with  water,  are  by  it  ehangeil  into  a  sub* 
■taacvso  far  nnaliii^'ni^  with  pepinne.  tlmt  the  chanicicrisltr  property  of  ^la- 
lloinlloi)  is  riilin-ly  hitt.  ('h'>iidrin  ami  the  elastic  lisiucii  uudrrgn  n  similar 
cbug*.     It  in  ti  '■''!.  liow  far  thla  cbaoge  is  due  simply  to  tbt 

acid  of  gaatrir  -  i:  .>  i  My  of  the  i>cp«io. 

(207.  .1  '  jnir.- -,n  milk.     It  lias  long  bean  known  that  an 

iafaninn  ol     :  i  i  n-h,  citllnl  •rnnrt,  has  a  remarkable  effect  in  rapidly 

enrdlio);  milk,  ami  thiif  pr»|icrty  is  made  uso  of  in  the  m.inufHi.-turie  of 
eheae.  (jastric  juict>  has  a  similar  ofleel;  milk  when  iiihjei-iml  to  the 
aetkio  of  ^trie  juice  is  first  eiirdlol  and  then  digmted.  If  a  few  drops  of 
gasirio  juiee  l>e  added  to  a  little  milk  in  a  losl-lul)o,  and  the  mixture  ox- 
ptanl  to  a  temperature  of  40'.  the  milk  will  curdle  into  a  complete  clot  in  a 
▼err  sbon  time.  If  tb«  action  l)e  coniioucd  ibe  curd  or  clot  will  be  ulli- 
DBtaIr  dlMolved  and  dig«at«d.  Milk  contains,  beside-  a  peculiar  fnnu,  or 
peculiar  form*  of  albumin,  fats,  mitk-^ugar  and  variotis  salines,  the  peculiar 

tarutrid  n»riii.  In  natural  milk  casein  is  present  in  solutiou.  and  "  curd- 
iag"  conaiaia  easeatiailj  in  the  Mluble  ca^iu  being  converted  (or  more 
pf^bly  na  wc  shall  aee  preKntly,  split  ujm  into  an  in^ilubie  m'xiilicalion 
af  cosrio,  which  as  it  is  lieiux  pr«cipitated  carries  down  with  it  a  great  deal 


310 


of  ihe  bt  ati'I  *o  funns  tlic  "ciinl,"  Now  ciUL-iH  ia  nwlily  jmN'iptutcd 
fiKtm  milk  upmi  the  mMiliuii  ul'  it  Hniutl  'iiiatility  nf  ncii],  mid  il  uiii,'lii  b« 
Biippi:«ed  tbnl  tlieciir<llin)^  (Hl-ct  (it'Eiistricjuiw  wns  due  to  it«  lu-td  rcacliun- 
But  thii  is  nol  tbc  niac,  lor  ticuiraliu^d  gastric  juice,  or  neutral  reaoet,  ia 
e(|ually  ufficiK-lou*. 

Tbc  t-urdling  nction  of  ivonet  is  cloHely  dependent  ao  temperature,  belrif; 
like  th<;  [H-]>lii'  HClion  of  f^tric  juice  favored  by  a  riw  of  (oiuperattir<>  up  tt> 
aImuC  -IO".  Mnrenvcr  the  (.-urdliug  m-liuu  ia  deetmyed  by  pn>i'ioua  builinx 
of  lh«  juico  or  nMiticL.  These  lacU  aaggeet  ihat  a  ferineui  is  al  (he  bodom 
of  itiu  niali«r:  and,  indeed,  all  ilie  features  of  itie  aciioii  support  llm  view. 
Mor«i>vcr.  as  a  mailer  of  fad.  a  vurdlioK  ferincDt  may  be  exiracled  by 
jrlyoi-fin  and  by  the  olber  metlioda  iiwil  for  (ircjiarin^c  feriiienia^  Tbe  fer- 
nK'iil.  however,  ia  unl  jwpalu  but  »<ioie  other  bmly ;  and  ilie  iwu  may  W 
»cpiiTiik-d  fr»ni  eaeb  other.  If  mu^nie^iium  i;arb>iii»lu  in  ]>uwiler  In-  i-aii- 
tioufly  added  to  ^'astrc  jiiiec  or  to  tia  infiiiiiiin  of  calve?'  alomuch  n  cu])ii>ua 
precipiliile  ie  formed.  If  thi-  adiliriou  of  niogMiium  oarboaat«  be  Uoj){inl 
aa  soon  nit  uuy  fiirilit^r  pr<-ri|iiijitir<ii  ct-aiKg  to  he  roiiivd  by  It,  and  the  mix- 
ture be  ullonei]  to  Aland,  the  cli.-ar  fluid  li:!!  abovf  the  predpitalv  will  Iw 
fouuil  to  I'urdli-  milk  reuililv,  but  r.v<'ii  when  iiciililiinl  to  have  no  iH-plic 
action  oil  pniU'iili'.  .iliowin^  ibat  thv^  nrri'ipiiiili-  euui^i^il  bv  Uio  addition  of 
Uh'  majcnoiuui  <-nrbiiual>.-  hn»  tiirrird  donii  all  thu  iK-pnn  (lut  M\  W'hiiid  at 
lca--i|  a  -^uxl  di-nl  'if  ihf  "  curdling"  or  r«n net- ferment. 

It  nii^hl  III-  (hou^'bt,  thai  tbo  rcnnei-tiirmeni,  rmuin  «i-  may  mil  it.  actcH 
by  inducing  »  iVrnictitnlion  in  the  sufrar  nf  milk,  giving  rite  Ui  laolie  noiil 
irhich  pn-L-tpitaCeil  the  casein  by  virtue  of  iu  Wog  an  acid.  But  ihl*  view 
ia  dispruved  by  the  foltowiit);  facts  which  show  that  the  fcrmettt  prixliiixv  ita 
nirttting  effect  by  acting  directly  on  the  natural  coeeio  its«lf  Casein  may  be 
precipiiated  uiK'hiiii);ed,  that  is,  capable  of  rediaHolvint;  in  water  (the  pres«m« 
of  culctc  fihoiipiiiiit.-  WiuK  axitunud)  by  «atunUiiig  milk  with  neutral  »altn« 
biHJii-^  I  sui-h  It*  uiiHum  chloride  or  magnealum  niiTpluilit.) ;  ami  by  betn;;  jifo- 
cipiialvd  anil  redi^iolvi'd  more  than  once  may  W  obiniuvd  lurgidy  fnv  from 
fat  and  wholly  fnc  from  niilk-:<ugar.  Such  milutious  of  iwlutvil  ciiaein  fretil 
from  milk-augar  uuiy  \ie  made  to  inirdlc  like  natural  milk  by  tbt-  adililion  of 
rvnnin.  xhoiring  that  the  milk-Ku^r  hiui  untbing  U>  do  with  tlio  matter. 
Morvovcr  the  precipitate  thrown  down  from  milk  by  dilute  acidn,  Imnii^  arid 
included,  is  itself  utmllercd  or  very  jjightly  alt^1r«l  <-iu>eiu.  nol  etinl.  and 
with  care  may  br  so  prepared  as  to  b<t  redioolvvd  into  solutionv  which 
eiinlle  with  rennin,  like  solutions  of  casein  prepnrvd  by  means  of  nctitral 
salts. 

When  iBolaf^l  casein  is  curdled  by  meaoH  of  reniiin  two  (>mt«iiW.  !t  u 
slated,  make  tbeir  appearance,  one  which  is  soluble  and  allied  to  albumin, 
aod  anotlier,  which  is  iimoluble  and  forms  the  eunl.  Curdling,  therefore, 
Bcoonliug  to  Ibis  result  apiveura  to  he  ibespliltins  up  by  a  ferment  of  ■  more 
complex  bmtv  ;  oiid  it  a  iutereslio);  to  olwerve.  as  ]ierliH]»  throwing  light  on 
the  ?iiiii<-wbat  analoKouH  formation  nf  the  librin.  that  this  cunlting  action 
will  not  laki-  plutn-  if  i-al<-ic  pb<>i|)hate  be  wholly  ulMeut  from  the  mixture. 
The  calcic  [itmni'hiiU'  apin-uni  to  pUiy  a  jwinliar  part  in  deterniiuin;:  the 
Inwcduhility  of  the  <-unl,  lor  tl»r«  ia  evidi-iK«  that  in  the  abwucc  of  catdc 
phiwphali-  ihi'  Itirmcnl  haa  [hiwit  Co  attack  itie  ciuein  and  »plit  it  up.  but 
that  iMilb  proilurin  n^maiii  in  »>iluii<iu;  if  calcic  phudpbate  be  pr«aeut,  Uto 
one.  vit,  the  curd,'  U-conuMi  tn-iotublc. 

Itonnin  i*  iibundant  in  the  kfO'tric  juice  and  in  thi-  ciLilrie  aiucoiiH  mem- 
branv  of  rrimiiiaul*,  but  it  also  found  in   the  grwlnc  juio:  of  other  animal*, 

■  It  nilRh*  tig  uirfiil.  Ill  iin)<-r  [»  <lL>iitu.-iitili  ll>«  -^unl  fraa  Ittx  TUIuia)  «diililDta«ctn,IOGklllba 
BmuH  Itrtfa  <it^.  •^Iiww.  aa>)  lu  rvwiiv  Uir  uuim  ot  iu-vIb  I<i(  itir  luiiir. 


flAblVA    AMI    ISASTItlr    Jl-ICB, 


SI  7 


■I 


it.  or  wJmt  we  ahull  pre^iiiily  liave  orcostoit  lo  speak  i>f  hh  ihe 
•f  tlit-rcniiriit  or  :ir""»;'^''.iit  |)ii«eiit  ulan  in  the  inuooui  iii«iiibr»iie 
riinfli  nr  iiKiM  iiiiiriiiil.'.     A  verr  Biniilar  if  tigt  Idtfultcnl  leriti«nl 
<i-D  r<>uD(l  in  niaiiv  |>Iiiiit(i. 


Tmk  &TKL*(-rrK».  i>K  Tiir.  Sauvaky   Glakik*.  Tiit:  OAi^ntK;  Mirooo 

Ml:MllltAXK.   TIIK    l'A^CItt:AO.    AM>  TIIK   lK-«»'IIA()t^. 

$  906.  i)«roT«  vm  etuily  the  iintiin?  of  llie  proiTWcti  liv  uhloli  ihe  sluoincfa 
BDii  ibewlivmry  glnnila  are  nble  ta  Mcrclo  ihe  >ra'<triL- iiiice  nii'l  giiliva,  whiMO 
rrroarkalile  pru|ier1i«a  we  have  jugt  dwrribet),  il  wit)  be  desirable  [o  mv  a 
few  tHiirxia  ou  the  stnicturo  of  bulb  the  above  or|;aDS, 

ThfXNigbout  the  rmter  {lart  of  il«  Ieii]>th.  rroni  ihe  curtHao  end  of  (he 
aanphvus  to  oear  the  aiius.  the  alimentary  caonl  is  eonslriieiiil  on  a  corlutn 
gHMralplan.  Thi*  pari  of  the  alitDenlary  eaosl  is  liirmed  i>ut  of  the  mid* 
jntt  of  the  embrj'D,  aiid  the  e(iil  helium  whii'h  tioes  it  is  of  hrpul'laittic  origin. 
tbr  mi'iiih  and  the  anua  hsv«  a  diflereitt  bHjfiii :  they  ure  n>rnie>)  hv  im-olii- 
tioiu  of  thi?  external  skin,  the  epithelium  uf  which  in  of  f;)ililnHtii;  origin; 
moA  th*  ptau  of  ttriielure  of  the  motith  ami  lerniinitl  fiortioii  of  the  n-cluin 
Ib  in  iBMne  Napeda  ditfL-rent  from  ihal  of  the  rent  of  the  nllraeniarr  i-anal. 
TIm  tranriilon  Atrni  ihv  vjiihluiiiii-  to  the  hypoblaatic  ninul  on-urii  in  Iha 
fvrlan  at  the  ani».  but  at  ihe  ulhor  end  i»  at  P>mv  dixlutK-e  from  tho  mouth 
drar  U(  ihi'  jiinrti'iu  of  tlx-  <i-H»phagu«  irilli  (he  ittamarh. 

'rtw  plan  uf  Rtnictiire  of  tbc  nypublaittic  [wriion  uf  the  ctstti  is  soiDewhat 
M  r»tkNn : 

A  "iW^  ^*7*f  '>f  cjliadricnl,  columnar,  cubical  nr  upheroidal  "  proto- 
plaamic  cells,  that  is  lo  «ay  cells  which  art  not  trniMfoniicd  into  Battened 
I'M  las,  forms  the  ininxslinte  liniiij;  of  the  niviiy.  Th«  celh  re^t  on  a  con- 
liMtlTa-lisme  basis,  irhieh  if  tioe,  delirale.  and  often  of  a  [leciilinr  nature 
ianwiliately  uiwler  the  epilhelium.  but  becomes  more  open,  loose,  and  coane 
•1  Mine  litlje  dimnnoe  fnun  the  cclk  This  ooonectinvt issue  basis  b  richly 
pntvided  with  bloodveueU  and  lymphatics,  and  also  eonlains  a  eertnin 
numborof  nerrca.  The  bhxxlvcMch  reach  up  to.  and  fine  capillary  networks 
an  eapecially  ahumlant  immediately  beneulh,  the  bases  of  the  eellK,  but  mmo 
fm»  l>ei«een  ihe  c«lb  ibemselvM;  the  whole  of  the  epithelium  i.-<  cxtm- 
*aacnlar.  The  connective  ti«ue  wliere  it  louche*  Ihe  eelU  formx  a  more  or 
Urm  vontiuuouB  slieei ;  this  is  nflen  «poke»  of  as  Ihe  baaeiiient  inrinhnino 
and  may  be  refcarded  as  the  demarcation  between  the  extra- vascular  cihiImv 
UutD  and  ihc  vaKular  e>jniiective-( issue  basis.  The  two  together,  th« 
•|)itlwtium  and  the  coniicctiv«>iisMie  ImuIs, form  what  U  known  as  the  muenv 

At  the  faMM  of  tho  crlindrical  eellj,  weilgcd  in  lMMw<«n  ihi'm  an<l  die 
lwia*n>cnl  meDibrane,  may  be  Mcd,  in  <'ertain  Hituatiou*  diitinetly,  in  other 
ailuBtioos  less  disiinctlv,  small  oetI«:  thai  is  to  Hay,  tvlU  the  IxMly  of  nhicb 
b  small  nUtivelr  to  itic  nucleus.  TIhsw  are  nupjvMM.tl  to  be  young  cells, 
brld  ID  merve  to  replace  any  of  iW  larscr  eylindnnO  <<clb  whicJi  may  from 
time  to  tinN  dbappoar :  if  «o,  the  epilhelium  dom  not  strictly  vumist  always 
of  a  Moel'  layer,  tbough  pmdically  il  nmy  )»  an  rugarded. 

Oulaide  tbo  mucnus  nH-mhram-  or  miiomK  coat  Ih  place*!  the  ihick  mutrut'ir 
coot.  Tbb  consists  of  two  lavcr*  of  pUin  mux-ular  Hbm.  an  inner  thicker 
layer,  in  which  the  fibre*  amf  bundU-s  -f  librcs  arc  disposed  cimilarly  mitiid 
the  lumcD  of  lh<'  alimcniarv  canal,  anil  nit  otiler,  thinm-r  one  in  which  the 
fibre*  are  di«p«s<.il  I'lDgituitinatly.  The  bnndh-*  and  ihtrteof  librcs  (see  Sd9) 
aio  bound  logrtber  by  oofineclive  ttnue  carryiu)^  IiIoimIci^swU.  lynipliatict,  and 


S18       TUE  TISSt'SS   AS'U    MECIIAMSMS  Or   UIOESTIOX. 


nervM,  and  a  tlitn  jliopt  of  conneclive  liuiie  more  nr  l««  diatinctly  Mpamteta 
till.*  lliickt-r  imit-r  cirt'iilur  mur-ciilar  vutil  rnmi  tliv  ihinni^r  mj(i;r  lou^tudituill 
iiiiiivutar  Liiiit. 

TIh'  iou'i-r  (irmilrr  narl  of  ihc  iiiticouii  mcinUmiio  where  it  lircrini(»  ntlnched 
111  tlio  muscular  cunt  ix  foniKil  nf  vi-ry  Iihw  coiinrolivv  ttviiio.  ihi?  inlvnpsoci 
of  the  hiiiidU^  Iw-iiig  lurgu  ami  'Hifn.  Tlii*  it  tpakta  nf  lu  th<- miimucQU4 
tijf*ur  nr  tulimufitin  roal.  It  i»  »■>  Iimiik-  that  the  iiiucmw  coiit  mn  raiilr  move 
over  llio  miJSviilnr  cont,  mid  along  il  tho  nnc  can  ciwily  br  (om  away  ironi 
the  "ihcr.  nmrc  cBBily  in  »iinif  pnttn  «f  the  caiml  tbiiii  in  utiien.  It  carries 
thf  larger  arU'He*^  mid  veiii«.  wlKwcgmallrr  tiniachcs  and  cnpillaries  |H(m  into 
■nd  front  the  niiioux  mendtranr.  Lyinf;  in  lln' nuioi>iJ»  membrane  bl  soma 
lilttc  ditiaiice  IVdiii  tho  c|iilhch[im  is  liioiid  »  tliin  layer  of  tilaio  muBCoUr 
fibres,  culled  the  lunirn  m»»fulari*  nmconr.  It  ie  niDrc  eoiiapieuous  iti  some 
eitunticiiis  thnii  Id  othere,  and  when  eomplete  consists  of  au  iiinf  r  siii^fle  Jayer 
of  fibres  dieposed  eireularly  and  an  out«r  single  Inver  of  fibres  disfioeed 
longiindiDally.  The  conueclive  tifeue  on  the  inside  of  th«  mtiscularia 
mucMie,  between  it  and  tbe  epithelium,  is  generally  i)f  a  aoniewlutl  fliirei*nl 
chaniL-ier  fronj  that  ouidide  the  muscuUrls  mueosie,  and  man y  jilaovs  U  of 
the  kind  called  •idenoid  or  retieuiar  tissue  ;  of  f  hib  we  thail  hereafter  have  l« 
speak. 

Lastly,  from  the  ^tonmcli  to  tli«  rectum  the  inuacular  coat  of  tbc  alimeuiary 
canal  is  covered  by  the  viitcenil  layer  of  the  i)eritoneiiiii,  Thi*  cuiuiiiiit  «f  a 
single  layer  of  ijolyjconal  tlatleued  nucleated  epithelioid  cellit  (beloHgioE  in 
reaJity  as  we  shall  vev  tr>  the  lyiiiphntic  syniem)  retliiiK  tm  a  ihiu  coniivctivc 
tissue  basis  uhich  ^cimrutb  them  I'mm  the  Imiuitudinnl  iniinciiUr  crjat. 

The  jjetieral  ^iliin  of  Riruciure  of  tliL-  ulimi-nlary  canal,  then,  in  iu  hvpo- 
hlastic  jiortinn,  ■»  a  compact  niuocidar  cual  iH.-|iarut«'d  by  n  l(iii«c,  more  or  Tea 
muvahli-.  Hubmiu'nU'  coat  from  a  fiiirly  roiupiul.  nmcotiH  c»al.  Thv  mucmis 
coal  ci>nsii>i»  of  a  viLHMilar  ci>niicctivc-li^uv  bivis,  in  which  ii  imbetlde«l  a 
thin  "pecinl  miiK-ntnr  sheet,  and  of  a  tingle  layer  iif  frpecial  hypt^laistic 
emthvlial  celli.  The  mnscular  coat  eon«iels  of  a  thick  inner  circular  aud  a 
tuin  oilier  loii(;iltidina1  layer  of  plain  muscular  fibre*,  and  the  whole  ia  Cov- 
ered with  an  epithelioid  peritoneal  laver. 

§  209.  Oliiu'lt.  The  Burlhee  of  the  muciius  membrane,  however,  ia  Dot 
even  and  unbroken.  Jt  dips  down  at  intervaU— thai  is  to  say,  it  is  involuted 
to  form  pockets  or  deprewiuna  sunk  into  the  underlying  connective  liMue, 
and  diOering  in  site  and  form  in  different  parts  of  the  alimeotary  canal. 
8ueh  an  involuticn  is  i-alled  a  y land.  The  most  simple  kind  of  gland  ia  a 
eylindrical  deprcHsiim  with  ii  blind  end.  somewhat  of  the  form  of  a  ttwl-tiibe, 
lined  with  a  sjngic  layer  of  epithelium  cells,  cuntinuous  at  the  mouth  of  the 
^land  with  the  rent  of  the  epithelium  of  the  mucou*  membmnc.  The  wall 
of  the  ;;1uud  outside  the  epithelium  in  siipplit-il  bv  the  connective  Itwun  of 
the  mucon»  membrane,  which  gt-iierally  forms  a  diMinct  bma-mi'nt  membrane, 
and  is  jti-nerally  also  richly  Mipidied  with  capillary  l>toodvr«»eIi.  Hcn<«, 
when  two  >nch  glamU  lie  side  by  aide,  a  ccrlaiu  rjuHntity  of  I'uniicctivc  tivuo 
carrying  blucxlvntu-U  ninj"  ui>  lulwcrn  thr-m  to  reach  the  epithelial  cells 
which  cover  the  surface  of  the  itiueous  membtmi';  lielween  their  mouths. 
Such  a  4nipl<'  tubular  gland  muy  hnve  the  wamc  diameter  throughout,  or 
mav  %-arr  in  diameter  at  diflii^reni  distances  from  tJi«  mouth,  and  tbe  epi- 
thelium lining  it  mav  be  of  the  same  chnrnttcr  ihrougbout  and  similar  to 
that  on  the  surfne^-s  lietween  the  ni<jiilliH  of  the  glimds ;  very  frujueutly,  how- 
ever, at  the  louer  part  of  the  ^land  the  ciMlholnini  is  mndilied,  and  takes  on 
certain  special  charaders  which  we  shall  speak  of  presently  an  thoM  of  a 
"secreting  ■"  epithelium.     When  this  occurs  the  upper  part'of  itie  gland. 


I 
I 


STnrcTVRK  or  the  stomach. 


819 


I 


the  p|iitli«)ium  it  not  ■o  modifiod.  u  <>lU-ti  spoken  of  h  "  the  duct "  of 

\  «tj  fnojumtly  tkc  ^Innd  u  not  tiniplc.  but  l>rnni-ltc<),  nod  tlw  branching 
umy  b«  ilwlit  <^r  vxcVMvt.  'iach  bnuH-bud  glnnds,  eapFci>lly  thoM  in  wbi«h 
tkc  brmnchiug  is  consi^k-nible.  an  cAlled  eomp«wid  gUnda;  and  in  tJiete 
ttMn  ia  Blwayi  a  wry  marked  distiiictioo  b«(«reen  the  temiiiuil  portiona  of 
tlra  MTViml  umncbiiip<  vrhcrc  ihe  epithelial  fiella  have  w«retiDg  obaracten. 
Mid  tW  |>rosiinal  porttona  or  ducts  wlicr«  the  cel)»  tiave  not  theae  secminfc 
dnnwUtB.  In  eucn  a  oompound  ^laiid  n  mbubar  maiii  dud  i,n'li(iBu  luoiilfi 
o(NM  into  the  interior  of  toe  aliaiciitarr  canal,  and  whoee  epithelial  lintDg 
h  eMtlnnoiu  wilb  the  smcral  epithelial  lining  of"  the  csnaJ)  dividea,  dicbolo- 
mooalr  uroth«rnwe,  into  »ec4>ndnry  ducts,  which  agaJD  divide  into  tujoller 
dncta,  aod  iliie  divtuon  may  be  r«{tc-ftied  ajrain  ana  a^in  ;  ultimately,  hov 
•Wi  each  duct  enib  in  a  part  in  uliich  the  epitbeliutu  laked  un  M«reliiig 
rhaiWlfri  and  fuvh  lenniual  )>i>rii'>n9of  ducta  which  ure  j|[vnerally  wider, 
mora  awvllrn  a*  it  nere.  ihaii  the  diieta  leading  to  iIh-ui.  and  nut  infroiiuentlf 
flaak-akaDMl,  are  >puk«u  of  aa  olvtoli.  Tlwac  ulveuli,  tsjit-ciidlj  when  iUwk- 
ihapiil.  bear  a  certain,  tboucb  br  no  mean*  clone,  rrsvmbtanoe  to  the  Indl- 
vidoal  berrioi  tm  a  bunch  or  gra|ie#,  the  duels  being  tbu  branching  (talka; 
baace,  than  conpound  i^IsixIh  are  si>okcit  uf  nx  "  niccmcaa."  8oineuin»  the 
glukd  io  ditidlns  apremU  <iut  luow-ly  ovrr  ii  widv  snrihoe — that  it  to  Mjr,  ia 
"difiMC;"  aooMUtnea  the  ducU  and  nlrcoli,  with  all  the  oonncclive  tSmat, 
blobdvanb,  etc..  belonging  to  them,  are  bvntid  np  tiehlly  into  a  more  or 
Im  etnbalar  oum — tiiai  i»  to  mv.  >'<>na  a  "  cumpnct  '  ghiDd. 

Ounda.  in  fiu't,  vary  widely  in  *txo,  foiin.  and  oomplenity,  but  thoy  nil 
hsva  an*  feature  in  c-ominnn,  Itiat  they,  being  involutiotiaof  the  mucoua 
i—nhiiiii,i  II  ill!  iil'ii  I  111!  f  I  mil  mini  eonnecliro  (iaaue  lined  by  efHthelium. 
aaJ  in  the  luajority  of  glamU  there  it  a  distinction  in  the  chanifltera  of  the 
«|ritWium  betireeu  u  terminal  eecreting  ii»niuu  nud  a  proximal  conducting 
portlMt. 

When,  aa  in  the  Mo<nach  and  iutettioe.  a  nuiuWr  of  ciKiipitntiiveJyaimple 
l^aadi  are  doeelv  pa«koi]  t»ge(her  fide  by  ude,  the  whole  niiicnun  luembnine 
■cquiraa  proponioDatcly  iucraodi-il  thickneM;  iuM«acl  uf  l>ciug  un  alleiiuulrd 
.fetnedof  a  wngr^  layer  i>f  i-i:IU  on  a  ihiu  conncctirc-tiwuc  boais,  it 
BW  a  naai  whotu-  thiclciicm  i«  deiermiim)  by  the  leagtli  of  the  glaDdi. 

It  Mtv  be  adtled  that  genorally,  but  not  ntway*,  the  gland  in  lU  whole 
bwtii  Iwi  above  >ir  uoKioe  the  mUKuhiria  mucoan,  to  that  wl>cn  a  vertical 
MtUoo  ii  made  of  a  mucona  membrane  the  aiiiM«lari«  mucuw  ia  aeeu  running 
in  aa  even  line  at  eooM  litUe  dialance  below  the  thick  layer  nhich  ia  |>n>- 
Hated  bjr  the  longitudinal  sections  of  the  glands. 

Beariag  in  mind  these  general  chiimcton  of  th«  aJimeiitary  canal  and  it* 
glaadat  we  nay  now  prootM  to  atudy  aome  of  its  Kpecial  diaracten,  and  it 
will  be  coDveDieat  to  bc^  with  the  rtruciurc  of  the  atonucb. 

Slnuiurt  of  the  Stomach. 

(  £10.  The  Homach  in  \\a  uructure  fuUufra  Ute  geiiemi  ptau  ju*l  duwribed, 
ami  nAtisIa  of  a  luufcular  c<>iil  and  a  inucouo  nieiiilirauc.  «e))araleil  from 
Meh  other  by  looee  Mibmucous  eonnevtive  tiiwie.  The  musculur  ooat,  which 
baa  ronsMerable  thiokneM,  conuiirs  of  au  outer,  somewhat  thiok,  limgitudinal 
nal,  awl  an  inner,  still  thicker,  circular  coat,  the  innerntost  buiidlen  of  which 
take  an  obliijoe  dintitinn  and  fuini  n  more  or  loM  dtMinct  thin  oldiiiuo  liiycr. 
As  wr  shall  Kr.  the  nh>vva»ent«  of  ihe  utoniach  an  tuon  eitetiaive  and  com- 
{■(vx  than  ihusv  uf  the  rvM  uf  the  aIin>outiiry  cwud.    TowBr<l  Ihv  pyloric 


H     As  wr  I 


320        THK    TlSiiVtiS    AM)    MKCIIANISMS   OF    UIOEf^TIUN.  M 

t^A.  in  uhflt  W  soiiietiiues  ciilleti  ibo  anlrum  pyfori,  the  circular  liiver  increaws 
ill  tbii-kni?M,  nud  at  tli«  jiylDrus  n  di^veloftvil  lutu  u  iliirk  riiijc.  cuilvd  th« 
8|>liiui-icr  of  ibe  pylurUB;  a  les§-marked  circular  agtliiiic-ter  it  iilio  |>rvH-Jit  nt 
tito  Clint hko  oriHce. 

Tli«  eitv  of  llie  cavity  of  tUe  sloiuuch  varie*  from  limo  to  tim*.  nvofling 
to  llie  )iulk  of  n^nieiiLH  [nvdciil  ami  llif  u<iii<liti»ii  of  tW  niiii'ciiiitr  |]l>rc«. 
When  the  MUiDiacb  is  empty,  tbo  niutctiliir  filnts  luv  in  ii  ilutr  •>(  ionic  cnn- 
tractioD,  urn]  the  cavity  ■•  »niiill:  vbeu  ilii>  »t«mat'li  in  Cult,  ihv  muscrilar 
iibro,  t1iuu|j[li  carrying  out,  as  wv^liall  x'r,  niorr  or  httf  rhytbtnicnl  ni»r»- 
menu,  are,  ua  a  tvhol«,  rvlaxci]  and  tixtitnileil,  <«>  that  Ihr  cnvity  \*  Inree. 
The  niucotid  nienibniac  in  Its  uaturiil  coiHlitinn,  sii  lo  #pcnk,  i»  of  iitch  a  eiae 
tliat  it  lurnia  a  smnoth,  even  liniiiff  li>  the  niiiw.'tilur  cont  when  this  is  extended 
and  relaxed  and  llio  cavity  dI  iTie  MtoiriHcli  distended.  Hcncv,  when  lli« 
etoDiarli  ih  empty,  nnil  llm  niufculnr  cual  oiitntcled.  tlit-  mucoiif  mriubiaa« 
t»  tbniwn  iiili)  folds  or  ru;;ir,  which,  on  nii-imni  of  the  ini.-|ionderaiice  of  ihe 
circular  miiAculitr  ccnil.  lake  a  Wigiliidinal  coiirra,  the  Imse  iiibmuojua 
timtuc  alhiwitij;  thi«  movement  of  llic  mueomi  over  the  niueculnr  ciiac. 

The  uiiiciiiin  membrane  is  reintively  very  thick,  the  thicknew  being  due 
to  the  fad  thiit  ihc  membrane  over  ils  whole  extent  it  thickly  rtudded  with 
gland*;  it  may,  in  fact,  be  «aid  to  be  almost  wholly  comjiufied  of  a  number 
of  shorl,  comj>nralively  "aimple."  elsndE  p1iK«d  vertically  aide  by  »ide 
and  bound  together  bv  juHt  as  mucn  connective  liesue  as  serTes  lo  nurrj 
tbe  liloodTcwelB  and  lyniphaiiwr.  These  glands  vary  iu  aiite,  ahane,  and 
character  in  diDerent  parW  of  the  Btnmacb.  and  Ihe  atomaclu  of  dtfft-Tciit 
aniinnl*  jin^wnl  in  these  rea|>ects  very  considerable  dilferencea;  but,  I'^r 
preetnt  pnrjiui^a,  we  may  consider  them  as  of  Ino  kiiidn,  ihc  glauda  at  the 
cardiac  rnd  of  the  alomacb,  or  "canliao  gUuda,"  and  the  glawh  at  the 
pyloric  end,  or  "  pyloric  glands." 

§811.  Canliae  t/hnd*.  Thrse  are  lubnlar  glnndH,  ubntit  O-'i  mm.  lo  2 
mm.  io  length  by  hiii'  to  UKlfU  in  width.  wIhm;  [ittirKc  t«  nut  wholly  siniigfal, 
but  wavy  '>r  gently  lortiioii»,  and  fn^qiieutly  curvnl  or  Iwnt  nt  the  Idind  end. 
fFi)£.  101.]  Some  an  simple  or  unbniuchttil,  but  others  divide  inlo  two, 
three,  or  oven  more  lube*.  They  are  packcit  liig^lhcr  si<le  by  side  in  a  ver- 
tical tKiMtioo  BO  closely  ihnt  in  section*  of  hnnlcncd  and  prepared  stotnocha 
in  which  the  bloodvessels  arc  for  the  most  imrt  emptied  of  blood  and  the 
lymjib  vpacCH  of  lymph,  each  gland  seems  to  he  separnicl  from  ila  neighbors 
by  Dutlimg  more  thun  an  extremely  thin  she^^t  of  connective  lissiie  seen  in 
Mctions  an  almost  a  mere  line.  In  the  living  stomach,  when  the  nanwmua 
bloodTCHclt  ill  thiit  oinnective  liune  ore  tilled  wilh  blood,  and  the  Ivnipb 
•pace*  nr«  dinti^ndeil  wilh*lymph.  the  glands  are  separated  from  each  other 
by  a  oonsidcrable  Hpace,  eifua!  probably  to  about  their  own  diameter. 

Tbe  outline  of  each  jj;luDd  is  defined  liy  a  distinct  biiseiueut  membrane, 
which  apjipar*  lo  be  formed  by  a  number  of  tiat  trauspar&nl  coniuictive- 
tinue  corpuN'lc*  fuaetl  tuKCtber  into  a  sheet;  iu  a  seciiou  of  a  gland,  longi- 
tudinal or  iransvcrw,  Mme  of  the  nuclei  belonging  i>i  the  cunatituciit  cvlla 
may  be  seen  imbiuldeil,  an  it  were,  iu  the  baaemant  luembraiK. 

£ach  g)i>nd  may  \k  divided  into  a  "  mouth,"  by  which  it  ojwna  into  tlic 
cavity  of  the  stomach,  and  which  rmchcx  alKiiit  a  third  or  a  rtnartor  down 
the  length  of  tlte  gland  and  into  a  "  bmly  "  which  forms  the  nwi  of  ihn  gland, 
the  Jnnciion  of  tlic  two  bring  calliil  ihe  "  Deck,"  Thmc  two  paf1»dif)br 
fumlantenlally  in  slriiclure. 

The  motitii  has  a  wide,  open  Iiiichi,  and  u  limil  with  a  single  layer  of 
lone,  eleuder,  conical  cells,  enlliil  "  nmcJiOH  wlls,"  The  lower  two-tliinU  of 
eoon  mucous  cell,  including  Ihc  piiiiucd  or  hlunC  or  sametimc>  ^tightly 
brutofaed  end  reAtiug  on  the  undi^rlying  bascmeol  membrane,  is  comi>ueoi)  of 


322        TlIK    TISSt'Ka    AM>    MECHANISMS    ftr    lUOKSTluV, 


Tlii;  iij3i«!r  tliinl  \*  moiw  i-lriir  itn<)  lmnit[tnrt.-iit,  A'X»  Dot  «uiin  r«ilil_T.  nn(f 
dtAi.-re  in  ii[if)r-nrniii-a  iit  iliflrrciit  tiniM.  At  nuc  time  this  part  iil'  the  c«II  i« 
oocupicil  l>y  tniini*;  at  amttlivr  tttni;  t)ic  iniii'iu  hiu  liwii  dUchKrgiil  bv  n 
mplurv  of  ibr  outer  fiiw-  or  lid  of  th«  ™ll,  k-aviiig  a  hiiiaII  cup8hft|»H)  csivitv 
(I'ODtsiiiini;  Huid  mid  u  irniiiiuu  of  iuiii;u«  i.  the  liiirly  distinct  vaUa  of  whiili 
lire  coTilinumm  vilh  iW  protopliumic  lower  two-thinlB  of  the  ct^U.  We  eliall 
bhortlr  liuvc  to  di^'iiw  nior«  fully  itiv  naliire  of  iiiucnu§  i.'elU  in  coiinectiou 
with  itie  KalivHry  glnnds,  and  niny  here  »iruply  say  ibac  in  llie  tipper  tliinl 
of  the  oell  the  cell-siibetaiice  of  the  cell,  exi^epl  fur  a  puftiun  which  reniaiiit 
lu  the  i-ell  wall  of  this  part  of  the  coll,  is  iraDfifunued  tiiln  mucus,  aud  that 
the  inucuH  so  foniied  ie  sooner  or  later  diachartfed  from  the  l-«I1.  Iu  |dnoe 
it^ug  \o  lime  ocoupied  by  new  cell  subeluice,  whiuh  again  lu  turn  u  ■.■on* 
verted  into  iiiucub, 

Thi»i*  Diucuus  celU  not  only  line  the  mouth*  of  tbo  gland*.  Ixvnniiug 
•Imrlor  where  the  mouth  joins  ihe  neuk,  but  n\m  cover  ihn  ridgia>  l>i;(ni'i;ii 
the  ^liindi,  uiii)  *o  furu  tbe  immediate  linint;  of  the  iiitrrior  of  the  ntoniiu-h. 
Th<-  fri'u  mirfai'e  or  lid  of  each  oell  is  men;  or  le«*  huxot^onal  or  |>olvgiitinl  iit 
outline,  ut)d  in  .^ectiunii  of  hardened  Hlonmch  tbt;  hiinlrnod  ccll-viills  of  the 
lope  of  the  d^lln  n'lve  hm  to  the  uppeuriuice  of  a  moiuiio  of  hcxa^mnl  or 
liolvgoiial  ureuM  where  the  wcctioii  |>r««cnTa  a  iiiiinlivr  of  lline  ccMt  ecvn  on 
vnd. 

Lying  between  the  buw  of  the  miKionit  cilli'  (which,  from  the  conical  form 
of  Uio  cells,  diverge  from  each  ••ther),  above  the  hiurnx^nt  membrsue, 
BUf  beSMn  in  TPrlica)  »c<-tioni<  u  i-i'rtnin  number  of  amnll  fell»,i-ach  coiiaRt* 
Ing  of  «  nurlouB  »urrounil«<d  by  a  vcllbxly,  whidi,  though  email,  stains 
deeply,  and  hence  lioconies  coiDpieiious  in  stained  soctioDs.  These,  as  ir« 
previously  Bai<l.  have  been  regarded  as  young  reserve  cells  which  will,  upon 
tJie  destruction  of  any  of  the  mucous  cells,  grow  ui>  to  take  their  place. 

g  218.  The  hoily  of  tbe  {(liiDd  is  not  only  in  iueif  distiuctly  leas  in  diam- 

btcr  than  the  mouth  Cso  that  a  larger  amount  of  vascular  connective  tiasua 

li»  l>aween  (lie  boiliu  than  between  the  mouths),  hut  has  a  much  uarmwor, 

indeed  very  narrow  anil  tortuouD  lumen,  atid  Is  lined  by  cell*  of  a  wholly 

different  character.     Thcte  are  of  two  kinilH. 

Tbroughotit  its  whole  K-jigth  helow  the  moutb  the  ghuid  i.->  tiiieii  conlinu* 
ously  with  a  lingle  layer  of  polylir^lnil  or  I'uhieal  or  nt  times  conicftl  c«llt, 
the  outlinvH  of  which  are  rr^murkiiUly  indixtiucl.  The  cell-body  of  each  of 
these,  which  contain"  n  ^phi-rii-al  iiucIi'-um  jiliii-eil  near  the  crnln-  of  the  cell, 
but  more  outside  loniird  the  hiwriiienl  niciiiliriuie.  varie*.  lu  we  shall  see  later 
OD.very  niLicb  in  iip|>v«rance  according  t-o  what  hiis  been  taking  place  in  the 
atomacii.  and  to  the  mmle  of  preparation.  In  scirtioni  of  a  elumach  hard- 
ened and  prepnnKl  in  an  urdinarv  way  ihe  crll-liodies  fre<|ucnlly  pivscnt  a 
"  iaintly  granular"  ap|>earnnco.  Cells  of  this  kin<l  are  spoken  of  from  their 
|naitioii  aaeeHlraf  cells,  or  Bomc4imM,  for  reasons  whidt  we  shall  see  presently. 
mtekief  cells. 

The  cells  of  the  other  kind  do  not  form  a  oontinuoiis  layer,  but  are  Mat- 
tered along  the  lenvlh  of  the  bivdy  of  the  gland,  being  moat  numerous  (but 
gntaller)  in  the  region  of  the  neck,  and  leas  frequent  l  nut  larger)  at  the  bot- 
tom or  fundus  of  tbo  );laiid.  They  are.  moreover,  in  the  lower  part  of  the 
eland,  aittl  indeed  over  the  greater  [>art  placed  outside  the  central  cells, 
being  wedged  io  IwtWM-n  tliese  and  the  basement  membrane,  and  freijiiently 
caanng  tlie  latter  lo  bulge  out:  they  therefore  in  luoil  cases  do  nol  abut  on 
the  lumen  of  the  ^'bind,  an>l  ihcir  only  direct  connection  with  the  lumeu  is 
through  »iuic(«  Ix'twcni  ibc  ccuiral  ''elln.  In  lite  neok  of  the  glaud  ihey  uniy 
however  bound  Ihe  lumen.  Kueh  cell  in  ovid  in  form  with  an  niitliiM 
which,  ill  Contrast  to  thai  of  iIk'  iviilrul  cell*,  is  sharp  and  well  defined,  aud 


STBUCTCRK   UF    THK   STOUAOU. 


828 


n  onttd  mK-Imn  j>l«oH  in  tho  miilille  of  m  mll-bodr  which,  like 
tint  oTtbr  »ncnil  oi'll,  vknn  in  iippmrnncr  niri-onlitig  lu  nrennuMooes,  but 
wUefa.  til  a  fwclioii  of  Ktnniiich  baMMiMl  sii<l  [ircparM  in  Kn  ordinnr;  way, 
b  rrcqucnllr  "  ooatMly  "  f;ninalnr.  Crllo  of  this  kiwi  nn  called  from  their 
ptiaiUiin  ftnrifUtl  celU,  or  from  their  shii|H-,  oi-oid  wMf,.  ^len  tlie  smaller  of 
tbcn  an-  ItirgtT  ihiiti  the  coiitra!  cells. 

Acfakriii'icri^iiic  "  ^nttrio  i^IiukI  "  thrnof  (he  cnnliMc  ref^on  of  tli« Moraach 
i*  a  labuUr  il<>|>r4«Moii,  otlen  Hittlght  am)  tinijile.  but  at  tiitiw  bifurcatiajf 
lovmrd  the  lower  |iart  or  otherwise  ilivirliiiu.  llic  eods  rret|U«Dtlr  curling. 
Kaeh  d^irasion  GODBJata  of  a  luoulh.  with  a  hnrnd  lumen  lined  by  sleuilor 
moawa  cell*,  a  neck  in  whioli  the  imicouH  eetl»  Buitdenly  (.'lianxi^  to  ceuiral 
fW»  witb  iiunierouB  ovoid  c«lla  lyins  aiuone  them,  and  in  which  (he 
lutnm  tMM»nw4  oarraired  and  Inrtuoiis.  and  a  bodyendiiif;  iu  a  blind  fuorliKi, 
with  the  luoMtD  Mill  narnin'  winding  biKwoen  the  ceiilral  («IU  ontdidu  which 
■rw  jilacml  avoid  evils  loM  iiumerciu*  than  in  ihe  neck.  Sneh  K'liniU  pliiccd 
aidr  )iy  aiito  fund  the  thickiKM  of  (he  mucriuti  membrane,  nm)  below  them 
at  a  a^rt  diflaiicc  run*  iti  a  Uderably  e\-eu  line  (lie  thin  muiteiilnria  muci»» 
wHb  it»  tingle  ioiier  circular  and  milt-r  lonjciUi'limit  tavent  of  iitain  tnuiculAr 
6bna. 

i  Sia.  Th«  *pM*  b«t«Mn  the  level  of  tin;  bottom  uf  the  glands  and  the 
otaaeataria  nueoNS  w  wdl  u>  the  vrrlii-al  njinciM  belwMD  th«  gland*— that  is, 
all  tlw  •)!«•  bMwwn  the  raiiel)  foldciil  ba»cment  mom  bra  ne  aba  ve  and  the 
■HMeoIarw  muouMP  below  is  occupi«xl  by  d«licati>  oitniTlirc  liseuo  (he  meali- 
wofkAf  which,  foTRMd  of  thin  narrow  shoetd  or  himinic  rnthcr  than  of  flbrea 
or  bvudka  bMom«»  «p«ci«lly  clow  »ct  imme<)ijitcly  nnder  thi>  basement 
Willi  a  nil  In  the  spaces  of  ihe  tncshwnrk  »  rvrlnin  number  of  lymph  cor- 
paaelaf  or  launtcylca  may  Iw  seen.  Small  aricrir^  ptwin);  upward  from  the 
aabwuwa  ihnMi)>fa  the  muHLtilaris  muPos»  break  up  into  capillnrieii  encir- 
diof  ibe  );lai"l^  <'■  >bt^  ^'^t™  '^f  plexuses  which  are  especially  cIom  set  at  the 
Mnrait*  tii  line  spaoes  between  tlie  };landa.  thai  is  to  uiy,  ut  the  placM  where 
tba  cnan««tiTe  tiKiie  Ilea  nearest  to  ihe  interior  of  the  stonioeh.  Small  vvioi 

rrin^nj;  from  these  capiltariex.  eniiecialty  from  thuM  last  luunoil,  running 
wnward  pierce  tlw  muacitlari»  mucosie  and  form  the  larger  vcii»  iit  the 
•abmuiMU*  cout.  Lymphniic  veMnU  and  .-itniclurM  eallcd  lymphatic  "  gland«" 
arv  prr*«nt  in  the  muoHi»  ciMit.  but  of  thrM.*  we  iihall  ^penk  tatvr  on. 

jl  814.  i'^/Urrie  ylmid*.  At  tbu  i>vluric  end  of  the  Mlomadi  th«  elaiidti  are 
Isadaselj  packed  than  at  (be  cnrdnu'  euil,aiiddiMVT  from  thecarniae  ghiniU 
fai  iter,  altaiic  ■n<)  stntcturr.  [Fig.  loi]  A  Irpical  pyioric  gland  poeHwea 
a  nouth  wnidi  t«  murh  longrr  nnd  gpnemlty  hroaoer  with  n  wiiler  liinieo 
Iba  mouth  of  a  cardiuc  glnm),  though  th<-  walls  aiv  limnl  with  mu- 
<  esll*  like  those  of  thr*  cardiue  end.  The  hmlv  of  the  glaixl  instead  of 
bainc.  m  !»  tiM-  canliuc  gtnnd.  »ft>.-n  lobular  and  unhranchol.  frec|ncnlly 
■livMMa  into  two  or  nion-  branches  c)o>e  to  the  nock,  nnd  (he»o  branches 
which  %tr  rrlnlively  cliortcr  than  Ihc  bnly  of  a  cardiac  ginnd  and  have 
a  iBurh  wider  lumen,  may  again  flubilivid'-  ut  thiil  the  whole  ghiod  is  most 
distiactly  branched.  The  whole  Imly  with  all  its  branches  from  the  mouth 
to  the  several  blind  ends  w  lined  throughout  with  one  kind  of  cell  only,  which 
la  vwy  similar  to  the  central  cell  of  a  pyloric  gland,  inasmuch  as  it  is  a  poly- 
bsdral  or  sliori  columnar  cell  with  indialinci  outlines,  a  spherical  nueleiia, 
and  a  adldwdy  which  in  a  suetfimen  prepareil  in  the  ordinary  way  is  faintly 
Kranular.  The  "  ovoid  "  cell  so  cliaracierisiic  of  the  cardiac  gland  is  niMent. 
Tbe  arrangement  of  tite  eouuective  tiaiue  with  its  bloodvessel.'i  and  lymph- 
atita  asd  of  the  muirulari*  muoKue  is  nmcb  the  aaiao  as  ai  the  canliac  end. 
Tbus  the  rariliuc  end  of  the  «toinarh  eootaina  gland*  which  are  tubular 
1  oAen  simple,  which  have  a  very  uurrow  Inmen,  and  which  potiess  con- 


3-2A 


THK    TISSUES    AND    HKCHAMSMS    OP   DIQBSTtON, 


tTsl  uoi}  ovoid  cella,  while th«  |>ylorio  end  cxulainitglaiKlH  which  iire  brniicti^), 
ithich  have  h  relntivclj*  ducp  mouth  aiid  wide  luweii,  mid  which  pueww  ihhs 
kind  of  ccIIa  unly,  <!eiurul  vtlh  i<r  udl*  v«ry  Uki 
f^'^  '^  l)i<-«f.     Id  the  nii'liUc  rtviixi  of  the  ftoniHdi  ibl 

iini-  liiiid  ol'gluitd  ^mdunlly  iiicrgrs  into  tbcothvr: 
ill  iiiiMiti};  rniiu  thi-  curiliii  to  ihv  pjlitruN  the  civoid 
cpU»  Wi^orh-  I<-iu  iiuiiivniui'  uuil  nl  hut  diMijijiviir, 
the  niouth  bi-ajiiiiif  luii^r,  th«  lunmu  wider,  uid 
the  body  of  Uiu  gliiud  iK-oamu*  more  und  diok 
brand  I  CI  1. 

Thv  ithuv«  niipplifg  n  f^nenil  (leMriptiuD  of  the 
gHstric  glttiidg,  but  thcM  vury  in  minor  characten 
utid  to  n  cvrtain  t'siuut  in  distnbuiiun  iii  diller«nt 
animnla;  tiiid  u*  wi-  »hall  pniiFijtly  «cc  in  all 
the  glaDd]>  vnry  in  ii>ndiiiun  lutd  sl>  id  oppcAnuc 
according  us  dig\'»tion  in  or  hue  been  goiof;  on  in 
the  etoinaeh. 

The  Salimry  Olands. 

>i  21fl.  The  Diructiiral    diflereucea   botweea  tbe 
"mucous"  uells  lining  ihe  omuth  aud  the  "  c«ni 
tral "  and  "  ovoid  "  eella  lining  the  Iwdy  nf  a  ga^i 
trie  gland    lead  ua  lo  inter  tliui  the  fonnor  diflrr 
fruiu  the  latter  in  limcliun  ;    and  wu  hare  oth<T 
evidence  Ihat  tWu  i»  so,  thai  it  is  the  central  ami 
ovoid  cella  which  aciually  oecretv  the  giwlric  juice, 
luid  that  a»  far  un  the  gaAlric  juice  is  cuncenied,  the 
tnonUiM  ol'  the  gUindx  Hervt:  diieHy   (though    liie^ 
niuciona  ooIIh  bnvv  a  pnrjxise  ul'  their  own)  to  coii-* 
diieC  lo  ibe  interior  of  the  ntomach  the  juice 
crated  by  the  li'idy  of  iho  gland.     We  may  tlief 
fore  speak  of  the  t><>dy  as  the  eecreling  (inrtiou  awl ' 
tbo  mouth  as  the  "  duct  "  of  the  gland. 

This  dialiaction  betneeii  a  secreting  portion 
a  conducting  |M>rtiun.  more  or  lees  obvioiig,  aa  « 
bai>~e  said,  m  must  glands,  is  esjiecially  Mrikinj; 
in  the  case  of  tbe  salivary  Klu"de.  Tbe»e  are  lovif 
lutlons  of  the  (cpiblastic)  inncona  metiibnuie  ol  the  nioutb  as  Uie  gastric 
elandft  are  involutions  of  tbe  (bypi'blaslic)  miicous  niumbrane  of  tbe  stomach  ; 
but,  insleail  of  being  ciimparatively  simple  they  are  exceedingly  brnndic' 
mcemoBc  glaudH,  uud  tbe  secreting  porlion  of  the  gland  iii  remov»l  Ui  a  |_ 
diatanoe  frum  tbe  epithelium  of  tiie  mouth  m  that  the  conducting  |>orlia 
is  of  very  great  length.  Moreuver,  nut  unly  the  epithelium  lining  thi 
secreting  {mrlioii,  but  aWi  that  lining  the  conducting  |K>rli»n  ditlers  m>  cob 
pl«t«ly  Iriim  Ihe  epihlasiic  e|>iihcliuiu  lining  the  inoutb  that  wc  niay  siudj' 
ib9  Mmctur*  of  the  gland  iiuile  apart  frutn  tlie  stnietare  of  the  lining  of  the 
moutb.  wbuitc  senMir}'  fiin(rlii>ni>,  in  the  way  of  laiclr,  fur  iuHtiiDce,  are  so  much 
mom  imporlaul  llmu  il»  digestive  t'uuctiuUN  ihul  we  may  renurve  the  study 
of  its  fcttlurw  until  we  comi-  l»  diul  nilh  tin-  KcnM». 

A  snlirar)-  gliuid,  such  nx  the  ^nlimaxiltury,  consists  of  n  long  main  duct 
which  pUT*uc«  lui  uudividt'd  course  backward  fur  several  centiiuetrtrs  trom 
its  onening  into  the  cavity  of  the  moutb  until  it  rencht^  ibc  body  of  llie 

E'  nii,  when  it  rapidly  divides  and  subdivides  into  a  number  of  smaller  due 
oh  oi'  Ihe  ultiinale  divisions  uf  the  duct  at  last  ends  in  a  "  secreting  " 


Al'iu-i.ii  uuxn  nMM  A 

eiiCTi03'0MiisI>c«"i*ToJl»nr. 

m.  mouib ;  n.  nK'lt;  tr.  • 

dMp    I^lUOO  of  >  lUbUlV   CDC 

iniwntMly.] 


vbich  ia  liitnl  by  n  " »wr«ltrii;  "  opilln-liiiin,  ttifftrrent  in  cliinirter  from 
iW  •ohlMliiiiii  liuin;^  llt«  diict«.  i^iicli  n  leniiinBl  sccnrliog  portion  J;  call<vl 
«a  imKtiiu.  Hataotimtt  »  duel  Urmiiuilcfl  in  a  »ins1v  alvonni*.  vihwh  then 
■pprati  u  It  swollen  or  aom«irhat  flack -Ah  npi-ii  lorminntion  of  the  duct  dis- 
tintciiiehr))  fmm  the  iliict  by  the  fliz«  and  elianicler  of  its  colls  and  bj  the 
Okrm«ti>eB»  of  il«  lumen  ;  but  more  commonly  n  duet  ends  in  Beversl  alveoli, 
whiHt  then  spiMwr  ■•  a  number  of  xhort  curred  Bonwirhnt  ewollen  tubra. 
br«nfhin|{  otF  from  the  end  of  the  duct.  AJI  the  duels  and  the  alveoli  iit 
which  ihej  eud  are  bound  up  by  coonecltvc  tia^ue,  carryiuK  bloiidveweU, 
ncrrea  and  lyn]|>tialica,  into  a  eompact,  rounded  bul  somewhat  lobulaled 
mam,  the  kLumI  |>n>|>er.  Each  alveolim,  or  eaL'h  ];r»<ip  ^(^  alveoli,  and  the 
saiali  duct  of  which  it  forms  the  blind  end  is  aurrounded  and  sepnrnleil  from 
tta  neiichbiirs  br  a  certaiu  araounl  of  i-oDtieetive  liaaue.  A  number  of  alveoli 
with  tAe  duel*  ^eadiui;  to  tlieni  are  bound  toxether  into  a  lobule  by  a  rather 
larjrer  Amount  of  connective  tiMue.  (imupi  of  these  smaller  lobules  are 
Iwtiud  MtrHber  bv  onutsi-iive  It^uf  and  env«l<>|ic't  by  a  more  distinct  ooal 
'if  that  tiatiie.  aixi  thus  form  liiricer  i<r  |>nnmrv  lobult^ ;  and  these  lar^r 
1)>In>)m  are  Iraund  up  to  form  tliv  glund  itsulf  liy  a  i|uanlily  nf  eonnwtive 
liaaa,  nrhich  al«a  fonm  ii  nrufipiuK  <>r  itheath  for  the  vrhole  gland.  Hen(« 
■  ihln  KVlion  taken  ihrviugh  lh«  (ilaiid  i*  w.-eu,  when  cxamin«<l  under  a  low 
powvr,  to  bedividi.ll  by  scpla  of  [;i>iRK^-tivc  tlitsue  (.continunuiwilb  tlii'  Hhealh 
of  lb«  tcland.  and  currving  btoodvMnI*,  cic.)  into  irregular  arMu.  vrhii-h  are 
■MlcnUTy  angular  from  comprarion.  ThiiK-  arm*  arc  w«tioii>  of  tho  prinuiry 
liibulea,  anil  nudi  may  In'  M'cn  to  l>e  nimiliirly  but  lew  distinctly  Nulidividnl 
lato  aUnilar  omaller  areiu.  the  »mnlliT  lobulot.  ICuh  of  ihetc  xmiillcr  lobules 
will  in  turn  b«eMO  to  be  for  the  most  (xtrt  niailo  np  of  rounded  boiliex  var}-> 
ing  aoraewhai  in  rise  ai>d  #hapv.  but  on  the  nhole  very  much  alike,  bound 
tDi^lber  bysBtnall  anvount  of  conncctiv*  tU8U«;  then  an  the  nlveoli  which, 
Mug  diapnaed  in  various  directions  and  being  frequently  more  or  )e8acurve<l, 
an  out  in  various  planes  by  tiie  section.  Where  the  section  cuts  the  alveolus 
UmBSTenely  the  outline  of  the  alveolus  is  ciroular,  where  obliquely  the  out- 
liiw  is  more  elliptical ;  a  aeciion,  moreover,  mnv  pass  through  the  mere  tip 
or  sido  of  the  alvvolus  and  so  misd  the  Imueu  allo^^ther ;  ami  indeed  many 
rsri«d  appearanoei  nay  be  prx^wnled.  Am'mg  these  alveoli  are  seen  other 
b<idi«>*ora  •oniewhatdiHerrutiiiiiWft.ctreular.elliplieal. or  cylindrical  in  out- 
liap,orbour-gla»Hba|)tHl,uri^ven  irregular  in  furm.  Thene  are  the  small  lubulsr 
duda  cat  in  variou*  pbtnca.  Se«lti>ii>  i>f  the  larjter  ducte  uf  various  siue  mav 
also  be  se«u  in  tl>e  Miiia  between  the  liibul««.  Even  with  ijuitu  a  low  power  it 
ia«My(a  distinguish  ueiwecn  the  alveoli  or  i«creiingelemeuta  and  tlte  duels. 
MhI  whtn  we  cddm>  Io  ezamine  them  more  elnsely  wa  find  that  ihey  <li0er 
naritadly  in  *tructurv.  Mnrrover,  when  we  eiuniine  the  three  glau<ls.  (wro- 
dd,  nbraaiillnry  and  (tiblingual,  ami  tvix-'cially  when  wi-  employ  fur  the 
purpoM  diflcreDt  kinds  of  animals,  we  lind  that,  while  iIk'  diicta  have  nearly 
ihaMiRiw  structun'  in  nil  ca«««.  two  kimltt  uf  alveoli  nia^  lie  diatinguisbed 
diShring  from  each  other  in  the  charactem  of  the  cells  lining  ibero.  In  the 
one  nu«-  ihu  (.vlls,  for  nMSoiM  which  will  prcseally  ttitfwar,  are  called  mMCmu 
trii*.  in  tlw  other  serow  («Ui.  or.  perhajw  btlWr,  owMwinmit  e*Ut.  In  one 
([laod  all  the  alveoli  mav  be  lined  with  niuMua  cells,  in  which  case  it  is  callcn) 
a  "  niucnus  );Iaiid."  or  with  albiiminouK  e<-ll».  in  which  cjuc  it  ia  callol  an 
"albuminous  gland,"  or  some  alveoU  may  be  "  mueoiM  "  and  olliers  "olbumi- 
D»iis,"il>c  gland  Itcin^- a  mixed  uue:  and  this  distinction  between  mucous  ami 
alliuniin'MS  olitniiMi  bIai>  in  glands  uf  Um  mucous  muinbnine  which  are  not 
il(«iin(ily  Mlivnry,  lor  instance  in  the  small  "  buccal "  gUixtn  of  the  mouth, 
and  in  (hr  v'lnnds  of  tjw  pulinonarv  paatngM 
$216.  J/iiMMi  ^ndM.    The  submaiilbiry 


and  of  other  slruciurok 
gland  uf  the  dog  is  a 


fiurly 


sae 


TtlK    TISSUES    A.\'l)    MEc-HANISHS   or    tilOSSTIOK. 


trpiral  mucouii  ghaA  [Pifr.  10.S].  Tho  alveoli  of  tht>  iclantllmrr  k  kwmI 
clml  in  Jiumi-tdr,  but  um  uii  nil  uvcru^'  iihuiit  ^A^.  Tnti  'xitlinr  ijI' t-noh 
tilr«oltia  i>  ili'-fiiK'il  by  n  itiRliiicl  liiiM^nK-iiL  nu'nibrum-  runiicd  nf  ii  ■lunibvc  nf 
tlull«iKil  onini-clivctiwui-  corpuncltv  fiiwil  Ingellicr  inio  nithn-t;  in  n  «colioo 
the  long  oviil  iiiiclvi  of  the  oiiiiRtitupnt  crlU  iniiy  be  wun  Wn'  mill  thi^rc  im- 
lM'<Idc<I,  nn  it  nrn.',  in  ihe  nmmbriinv.  Oui«iilo  tlic  bnwini'iit  nicmbmiic  li^, 
va  i-lxcHbcrr  in  n  mucous  mcnibrnne,  ihv  Ivmph  cpnccs  of  the  fiop  i-oniiecli\'«i 
Umuc 

[Flo.  103. 


ftmAXiiUHV  Oi.txii  OP  1  Dno. 

■.  fBunHM'cflh^  h  pmoiilannlp  celli :  o,  ileuilIniiD  celli :  <  trumtne  lecllon  oraii  cicrMorF  ilDct 

wltb  lu  pMuUkr  Qolnuiiur  qilttwIUI  n>IU.| 

Tbe  tjpnce  defined  by  [lie  basemeDt  membrBoe  Ih  nmrltr  wliAtly  fi\M.  a. 
vury  siuall  ceuiml  luiii«n  only  bang  left,  bjr  c«ll»  arraiigid  for  ibit  lunvt  t>urt 
in  B  tiiu){)<-  layi-r.  Tli<-  rclU  are  large  relnlivek  to  the  rIvciiIuk.  mi  ibiit  in  ■  ' 
iniUHVi-nK-  si-i-liuii  of  nil  iilvenlun  about  firo  or  nix  eell«  irill  be  awn.  KncEl 
crlt  In  luoru  nr  i(^  MilKridd  or  riilhiT  coiiickl  in  t'orm,  with  it«  broiuU-r  Inw, 
which  i*  VDiiiotiiucii  irregiiliir  in  outHiie,  miiiig  on  the  bavfinunt  menibnne 
and  ihe  narrowtr  a|MUC  abutting  on  tho.  liimrn.  Thi-  ehnrttclcnc  "f  the  cell 
difltr  aedirdine  to  thi>  condition  of  llic  gland.  If  (be  ^Iiind  hn»,  prrvioiia 
to  ili  prvnantion  for  exiiminntion.  lu'l  hi-en  nctirely  recrt-ting,  lh«  crll*  have 
certain  ciiariict«n,  nud  innv  Iw  i>)ioken  of  a«  "  loadctl"  or  "ebarccd."  If 
tbe  gland  bas  boon  flclircfir  ^ecreling.  theto  i-hnmclprs  are  replaced  by 
nilKn.  and  the  cells  nmy  be  tpokca  of  ns  "  iinlnaded."  "  dlKharged."  In  tb« 
"  loaded,"  or  as  it  !■  often  called  the  "  resting  "  pba^,  the  cell,  in  hardened 
Bpeoiniens,  is  as  a  whole  trnneparvnt,  and  stains  verv  slielilly  with  the  ordi- 
nary staining  reagenU,  Tbe  nucleus,  whifli  in  haiaeued  specimens  npiwars 
ditw-eliaped  and  eoineliinea  curved  or  bent,  but  in  the  fresh  living  coll  is  neeo 
lu  be  splierical.  lies  at  the  bare  of  the  cell  not  far  from  tbe  hiiseiuent  mem- 
brane Arotiud  ih«  nitcleus  is  gathered  a  email  i|UBntily  of  Drvliuary  pm4u- 
plamic  cell -Hubeiauce,  Maining  r^mdily  uitli  tbe  usual  dyva;  tbe  reit  of  tite 
cell-body  eonabia  of  a  tramparent  nialerial.  which  dora  out  stain  readily, 
and  wbicb  oceupiea  the  anavea  or  mt^lit^  of  a  v«ry  ilelicMtc  me«hwoTk  c<>n-' 
linu'iUf,  apiwrciitlViWiih  the  (tlaiuiiig  pnit'iphiMitiir  <M.-ll'MilBtance  around  tlie 
nueU-UK,  and  with  a  thin  *be«t  nf  >iimlar  miitcrial  forming  tla*  wall  of  the 


THR    SALITARV    GLAJtDS. 


327 


I 
I 


cell.  Tliia  tnotfittKnt  inaterinl  h  cillier  luiiviii,  uliicb  wc  hnvo  teen  to  be 
«  n'iw]McuauBConHilu«ni  nf  viilxuaxitlarv  «nliva  liii  llin  >l<ig),  om  •uhaUncc 
whk-h  Mn  easily  bv  ciinvcrt«<l  into  ncttiiil  miicia,  tbal  i»  to  nv,  an  siilccodeul 
hF  luuciu  ;  lienve  tbL>  oatuc  "  mui-ous  ciOl."  A  nttling  nr  Imdvd  mucoua  ooll, 
UwB,  coDUiU  [ar}[«ly  nf  mucin  (or  ii«  nnu'coili-nt )  li«)j.rri]  in  th«  mwliM  of 
t^  piniot>laiiBiic  cvjl-*u))MtNnci.- vtliiel)  nvvr  iW  grciitcr  pnrt  of  tfao  ccl]  dxiita, 
in  ■  banlriiiHl  ^liiuil  iii  mir  rate,  a*  ii  lii-licnu-  m«»hworK  or  roiieiilum,  biit '» 
gktlwml  inii>  11  i-i>in|)Mrl  iiihi'  in  n  ^nialt  nrc«  immt^lintvly  nroiitKl  the  iiucloun. 

Id  manv  alveoli  n  moro  or  l<9«  triKiicuIar  »pnec  k-fl  l>et»«%n  thv  diverging 
IwMi  of  l«<>  of  lliv  mucwii  <.iOIh  nii'.l  [no  boM^mcnt  ni«inbnine  niuy  bo  wen 
tn  be  <ic«upi«d  bv  irDi>  or  hjr  two  or  more  pecnlinr  small  cells.  Thf««  on 
vzuniDtttioD  an  <ouimI  tu  W  irregular  in  form,  but  oileo  half  moon -sh  a  pod, 
and  >rr  Imimm  called  liemUune  cell*,  Kocli  consbts  of  deeply  eUiiDiDg  ccll- 
Bab«t«DC«  with  b  Bpherii-nl  Ducleus,  From  their  tiie  and  their  slAining 
dMplv.  M  veil  M  from  their  position,  these  demilune  cells  cuntrast  sirongl}- 
wkn  ih«  mucous  rells. 

In  the  "diKbarf^cd,"  or  as  it  ia  often  called  the  "active"  phase,  the 
nacoiH  mII  has  a  different  a|i|>euranoe,  aipecially  if  ibf  activity  of  the 
gfatml  has  been  irreat.  The  i-ell  in  i»ow  amalW,  ami  Ihiu  fr<ves  rioe  to  a  mora 
oiMtnet  lOBieB  in  the  alvoi'lun,  n  liLr;:i-r  |>orlii>n  of  thu  cell  (tiiiiu,  especially 
Ml  iho  miUr  side,  attd  Aui»vtimi.-»  l}i«  wholt?  itII  i>taiii!>;  the  iiucleuH,  now 
spherical  even  in  bardeiiLtl  ■(lefimtiis.  iK.-cn[ii('9i  a  mtirv  Miilnil  poHilioii.  The 
irBiMfiareDl,  nuu  vtainiDi;  mucin  hiu  in  Inrgr  part  tir  wliolly  ili.->ap)Kuired,  its 
ptaw  luu  b(«ii  taken  by  onlinnrv  Ktnintnu;  prut'iplniiniic  c<'ll-i>nhilance,  aod 
tba  diatiuclion  lH:t«<^-n  the  cicmilunti  cvll<  iind  the  pri>i>er  gvIIn  of  the  alveo* 
liw  it  nueh  ln«  diiiinrt.  Wi-  »hnll  prtaeiitly  have  to  aiacuai  the  iiatura  and 
aw atag  of  lhi»  chungr  frnm  ihr  Inatlcd  to  the  di'chargad  cell. 

S2I7.  A  (mall  dun  of  the  «iibniiixillary  gland,  even  when  cut  tnioRvcnwly 
in  the  section  bo  as  tu  pmeiit  like  many  alveoli  a  circular  outline,  has  an 
a|ip«aninc«  very  dil&rent  from  that  of  an  alveolus.  The  duet  is  lined  by  a 
mjtla  layer  of  epithelium,  but  thew  are  slender,  narrow,  columnar  cells, 
laaTiDfc  in  tli«  centre  a  relatively  wide  lumen,  and  the  outside  of  tlie  duot  is 
BOt  so  sharply  defined  by  a  coiispicuoue  liai»emeiit  membrane  ss  is  the  case  in 
an  alveolus.  Each  c«ll,  whieli  iK-am  an  -u-al  iiui'kuH  plat-ed  vertically  in 
the  cvW  at  sImui  the  middle,  but  milicr  near  the  huitc,  consists  of  a  prolo- 

rilBitiiic  cvlI'MibMauce  which  «n  th«  inner  side  of  the  iiudeus  towaixl  the 
umi^n  has  no  sfwcial  fi-alnr(?>.  hut  on  the  outside,  toward  the  basement 
nwnihniue  or  ooiinectivc  limue  Iwvi*,  haii  fn-qticnily  a  i<digiuidiual  striaiion, 
as  if  niB'te  up  of  a  nuuilx^r  of  rmlK  or  narrow  jiriMiis  idaoeil  xide  by  Md& 

Thr  InrEer  ducts  running'  bi'lw<x-n  (be  Iot>iili-i>  iHtb-r  from  .lucb  a  Kmall 
inira-loUilnr  duot  vbiefly  in  the  gn'atcr  thirkncxs  of  l.hi.-  (.-i>unt-clJv«-UNMe 
ba*i».  which  in  tbew  is  develojH-il  into  a  iliilim-t  coal  coniaining  In  the  caw 
of  the  larger  brnnches  and  the  main  duel  niaiu  muoniliir  tibrm.  In  the 
Dkaln  duct  and  it*  rhief  branches  the  single  layer  of  columnar  cells  is 
rrplanril  br  two  »r  three  lavvrs  of  aibicnl  or  soniclimcw  ttatlened  cells  iKrt 
marknl  wilb  thcslrisiion  spoken  of  above.  When  a  small  intni-lobular 
dud  is  about  lo  end  in  an  alveolus  or  a  group  of  alveoli  it  beooincs  nar< 
mwn),  the  cells  [iwe  their  striaiion,  from  being  slender  and  cylindrical  in 
form  become  sbori,  cubical,  and  st  tlic  very  end  of  the  duct  chnnge  inhi  Hat 
•iiitidU-  (hDiivtl  plates,  the  tranntion  front  which  lo  the  cha  met  eristic  cells  of 
inr  iiheidiis  is  in  ihe  esse  of  meet  animals  <)uite  abrupt.  Such  a  UMKlilied 
lerniinal  [Hirtion  iif  a  duct  is  sometimes  spoken  of  as  a  "  ductule." 

\  216.  Albuminuua  'tlaniln.  Thoe  differ  from  the  mucous  glands  in  the 
r>iii>tiiutvin  «f  the  cells  lining  the  alveoli,  but  the  structure  i.<f  tW  duels  and 
iho  gvneral  aiiaiigemeitls  of  the  gland  are  the  imiue  in  both ;  indeed,  aa  we 


I 


S*23        TUE   TIBSUSS    ANIi    MKHH.VNISMS   «r    UIUBSTION. 

Iuiv«  already  aaid,  !n  the  snme  gland  some  alveuli  inmy  be  albumiDoii 
othere  inucouB. 

Id  ai)  ttlltuminouB  alveolus  the  wIU  are  ratber  smaller  than  thow  tu  a 
loiuli'J  muci>iiB  Klaii'I.  a"d  their  oiitlitiee  are  ratber  mure  angular.  In  each 
tell  the  uucleua.  which  U  spherical,  U  placed  near  the  centre  of  the  cell,  but 
rather  uear  the  basement  ineinhrune,  and  the  eelt-Aub^tADoe,  which  has  the 
general  appearance  in  an  urdiDary  nrvparation  of  aciuiewhat  densely  granular 
pnituploHni.  Htaiiis  readily  and  uniloriuly  all  uver.  \o  cells  <yirrea ponding 
to  the  demiliinea  of  a  iuucouh  alveoluit  are  nrmwut.  In  Tiuit,  an  albtiminout 
c«ll  dwa  not  at  6nt  night  apftoitr  tu  ilifler  niarkedlv  from  a  iltwharged 
mucous  coll,  and  iloea  nut  Hhnw  the  .lamc  tiinrki-il  (liHvrenoM  between  a 
loadei)  and  a  diitchargei)  oinrlitiun  an  dcjnt  a  niucou*  cell.  There  arv,  how- 
ever, difli'renout  betwoen  t)ie  loaded  and  di^iHmrgod  albuminous  cell,  bnt  to 
lliMc  we  shall  n'tiirn  prratc-iiily. 

The  parotid  eliin<l  nf  mnn,  and  indeed  of  all  mnmmalM.  is  a  wholly  «lbu> 
niinoiis  gland,  though  in  the  dog  n  fen*  cells  arc  mucous;  the  siibmaxillary 
of  mau  is  on  the  whole  a  mucoii*  glutid,  bnt  some  tobulea  in  it  are  albuminous ; 
tbeflubmaxillary  of  the  nibhit  is  an  lUbuminouB  gland.  The  sublingual  may 
perhaps  in  all  mammnle  he  regarded  as  a  aiucoub  gland,  though  it  diifbn  in 
aereral  respects  from  other  mucouB  glands:  the  L'ellfi  lining  the  ducts  are  much 
shorter  ana  lees  distinctly  striated,  the  alveoli  are  more  obviously  branched 
tubules,  and  llie  cells  of  some  alveoli  contain  no  mucin. 

The  Braall  buccal  glands  which  lie  in  the  nuWance  of  the  mucous  meia- 
brwie  of  the  mouth,  and  whose  secretion  eontributej  lo  "  mixeil "  saliva,  are 
formeil  on  a  small  scale  aAer  the  plan  of  a  salivary  glan'l— tlmi  ia  to  say, 
they  are  cunipused  of  a  duet  (or  ducts)  and  alveoli  which  in  ntructure  are 
ximilar  to  thine  of  a  salivary  gland.  They  furiher  rt«emhle  the  sulivary 
glands  in  that  some  of  ihein  are  "albuminou*"  and  some  "mucous." 

S  219-  The  salivary  gland:"  have  each  of  them  a  "pccinl  nervous  supply  of 
which  we  shall  spcalx  in  detail  in  the  following  section,  and  will  here  simply 
say  ihnt  the  librcs  pawing  into  the  ^lnnd»  are  both  mcdullatod  and  nna- 
medullated  libree.  and  thai  the  terminations  of  the  fibres  have  not  been  as 
yet  exactly  made  out :  for,  though  it  htis  been  nmintained  by  some  oWrvcrs 
that  tome  of  the  nerve-tibres  end  in  (ho  secreting  oelli^,  this  has  not  been 
fnlinfttotorily  proved.  Numerous  nerve-cella  may  he  seen  scaliered  along 
the  nerre-fibrea,  where  they  paaa  into  the  glands  at  the  "  hilus."  whence  the 
main  duct  iiuuee. 

Of  the  n<TVOiis  supply  of  the  stomach,  derived  tiartly  from  both  vagi 
ncrviM  and  pnrlly  fr>iiu  the  solar  plexus,  we  ehall  also  have  to  a|wak  later 
on  :  we  may  here  ximnly  say  that  tnc  fibres  end  for  the  most  part  in  a  (ie«u- 
linr  plcxuR  Iv-tween  the  circular  and  longitudinal  muHcular  layeni,  and  Jo 
anolhvr  {n^culinr  plcxu*  in  the  submucous  wM.,  the  two  plexusuct  oorrc*]M>iMl- 
ing  lowhni  we  ^linll  dc*cribe  in  the  small  intiwline  a«  the  plexus  of  Auerbach 
and  (he  plcxu«  of  MeiRinej-. 


§220.  The  stnicture  of  the  pancreas  »  so  similar  to  that  of  a  salivary 
gland  that,  (hough  we  shall  not  deal  with  the  pr»pcrtie«  and  characters  of 
Uie  juancreatic  juice  until  later  on,  il  will  be  convenient  to  consider  the 
hisloln){v  of  ihe  gland  now. 

Wlietlier  as  in  man,  in  the  dog,  and  in  most  other  animab  it  forni7<  a 
compact  mail*,  or  as  in  the  rabbit  is  spread  out  into  a  thin  sheet,  the  pan- 
croiu  is  in  all  eoMa  a  cumiiound  racemose  gland.  coDBtsting  of  <luctA  and 
alve(di  arranged  in  lul>eA  and  lubul«a.    [Fig.  104.]     In  man  (he  smaller 


A 


339 

daeu  Joie  one  bmuii  duot.  nhicti.  runoinii  leiii-iliwiM-  thr>iiK)i  llic  iil>'")< 

pi»fw    dw  OOMla  of  tbe  dutMlmiiiiu   in  cimijiimv  nilb   hm'I    ojiL'tui   inU>  the 

wUrioroTlhe  iotcstine  hj  an  oritirc  L-onim»n  loit  bikI  id  Ihf  Inlc  >luct.    Nut 

iafrai|Uetltl<r  ■  Moond   bui  Hnuiller  main  iluot  ivirDiHic  rr<iiii  llii'  tiiwi^r  piirt  of 

lb*  Mad  uf  the  f;laiKl  join*  the  int(«tiiie  luutr  ilnun;  in  the  dog  mvh  n 

«*t»ilid  dptt  is*  i»uhI  •M-nirrvni.-v.     In  the  rabbit  (he  miiiii  duct  dot*  nut 

join  tin  inirttinv  nilh  lli«  l>il«  dtiL-t.  but  «l  ii  ninnidcrahlc  dUtCDce,  •H^vt-nil 

<«alttB«lfT*.  la«or  dnwii.  »o  ibnt  in  ihiK  nnimnl  iIh-  hibt  nnd  iiKncmiit-  juivn 

■r*  iKit  putiraJ  iif]^ilM-r  iiiiu  ihi*  iiit<^ini*,  btii  ihc  fix»i  in  for  a  diNiunct-  expiwicd 

to  llw  KtNn  of  tlit  formtr  bwfun,-  it  uiii-iii  iriib  ihi-  Inller. 


{Vm.  IM. 


Sn-niw  V*  niE  r*>caKu  or  iiii  Inn. 
4.  Itnnlniulaii  at  ■  ilati  to  Ihv  lulialai  *Itm<I.  ■>'•■] 


li«  HtrucluiT  nf  the  ducts  m.  in  all  ew«niial  p(>inli>.  similnr  to  that  of  Uw 
vbct*  (if  a  salivary  );hind.  tjive  that  iho  Mriuiion  of  ihi-  eipilh«liiil  crils  i*  lea 
4i«iatl.  Ai  in  ike  cue  of  ibe  Mlinuy  );land.  Ihe  ductule,  or  unrrtxr  Icr- 
■inaJ  nortioD  of  tbe  duct,  jou  m  it  JINM  the  alveoli  is  liiwt  bv  llul  »pindU>- 
ihuvl  cells. 

tImi  alvtoli  also  are  •iiuilar  to  tlioae  of  a  lalivary  tcla^d  mv«  perhaps  that 
they  an  nUtivcly  lonni^r  and  more  tubular:  tbe  Inmeii  in  all  eaaea  ih  vcrj 
nartnw.  A*  cuniiinrcd  with  n  salivary  glaud  tbe  alveuli  art-  relatively  mom 
Daneroua  tlian  the  duct»,  *<i  that  in  a  neotion  of  Ibe  gland  relatively  fewer 
ducta  are  area  cat  acni«L  l-^icb  ulvcoluit  in  liued  with  on«  kind  uf  cell  only, 
which  >*  much  murf  «imiltir  to  an  alburoiii'vut  than  to  n  niurous  cell :  there 
wa  no  ilemihine  rellsL  The  more  minute  luaturM  of  the  alveolo*  differ  ac- 
ennling  a*  lh<'  iflatid  has  In-en  "rctiling"  and  an  in  "  taa<)<<d."  or  han  beca 
''active"  niid  •■>  i*  " dMrhargvd."  The  wIIm  lining  tlte  alvouluik  are  more  or 
lea*  polyUnlml  in  fi>rni,  and  each  cell  cwumhIh  nf  a  olwr  tnuu|>nreni  cell- 
badr.in  which  mx-nra  niim)>er  i>f  n-fraelirr  divcntte  "gnnulM;"  a  sphorical 
•acltu*  lie*  at  alKuii  the  oiiier  ibinl  of  the  cult.  In  a  "  load«d"  oell  ibeaa 
gnuHilca  ar«  vvry  abtindnni.  and  reach  froni  Iha  narrow,  iiicunffiiiiio^u  lumeti 
M  Bear  ih«  oalrr  mari^n  "f  the  call,  au  as  to  leave  only  a  narrow  dear  traaa- 
parent  f><ne  imiiiediuiciv  bordering  nil  tbo  baa>Di«nt  tnemhrniw;  tha  c*ll-aab- 
KanM-  is  so  ihicLly  8liiil<ltil  with  tbne  " f:T«iiiilfa "  that  the  nuclmM  b  eona- 
ptelelr  bidden,  and  th^  grmlcr  jiart  of  tbe  cell  apfwara  quiti' ilark.  In  a 
"  dtBcnargtd  "  cell  these  granules  are  far  km  numercMS,  and  arv  Urgrlr  con- 
Inad  to  tbe  inner  pan  of  Ilie  cell  abutting  on  tlw  Innx-n.  so  that  liu-m  la 
«alablMbad  a  clear  diMtinctioD  betireeu  a  narruw  iniHr  "  gninular  "  ton*  aiid 


330       TRK   TIBRrEB    AXn    «BCI 


VlOKSTIOS. 


a  dt*r  traodiiarent  outer  xone,  free  or  nearly  free  ttom  gnmulee.  The  widtli 
of  the  frranular  loat;  varieti  in  (nut  with  the  condition  of  lii«  gland  ;  when 
the  ^Inncl  hua  bem  very  nc-iivt?  llie  Kmiiular  zone  is  very  oarrow.  when  mod- 
vrnli.-l;t'  uitlvc,  it  i^  broiiilirr,  iiml  nhen  the  )(lan<l  has  been  for  amne  time 
whiill)'  vt  n*t  nod  i*  Lhi-itifnro  lomlt^l.  th«!  ){runii)iir  tone  inuy  eDoixMoh  on 
ueurl}- the  wholly  Cull.  But  wc»liall  have  to  return  to  then;  inalten  pre*- 
ently. 

In  thd  paticmu  'if  lh«  rahhit  and  90mt  other  animal*  sroupa  of  edia  of  a 
pocutiiir  nnturr  may  he  nva  iiiii'r(-aliit«d  at  tnter^'iiU  in  the  midtt  of  tlie  true 
glitndithir  giiluitniico.  Thoiw  arc  rounded  or  pulyhixlrul  in  form,  aad  have 
a  cU-ar  ■.-Hl-'iibstaticc  with  a  relativclv  large  nucleus ;  they  do  not  fortn 
nlvc><>li  and  lh«v  have  no  (hict«.  Racli  of  ihcw;  gn>uf)8  i»  mipnlicd  with 
hIootivvM>«ls  formint;  n  caniltrirA'  nelnork  more  closely  net  than  i-WwIutc.  The 
exHcl  nature  of  thcw  cgIIm  if  nt  pruent  n  matter  of  douhl. 

The  |iiincrci»s  in  supplied  with  tierveB  coming  tr^im  the  solar  picxuv,  and 
coneisling  partly  of  mcditlhted  and  partly  of  non-med  ill  tilled  Rhrva.  An  in 
the  ca<e  of  tlm  salivary  glands  nerve-cells  are  Ibund  in  cunncction  irith  thv 
nervp-fihres  ns  these  pnss  into  the  gland. 


The  Strwture  of  the  (Knophii^/iu. 


S  S31.  In  the  general  plan  of  it»  xtniclure  thn  (fsiipI]H|.'itEi  re-iembled  the 
real  of  the  nlimeulary  canal,  for  it  consists  nf  a  muc»u:i  iiiemhraue.  with  a 
niunciilarii)  miucomd  and  glanili*,  a  loose  xubniucotie  coat,  and  a  muscular  ooAt 
Cunipriviiig  an  inner  circular  and  an  outer  longitudinal  layer.  But  tbe 
tfiithelium,  ooiblcietie  in  origin.  \f  very  diflerenl  from  that  of  the  ri'madi  or 
intevlino,  and  hoth  circular  aiul  longiludinat  muscular  layer*  ar«i  ooinpuaed 
U)  a  large  extent  not  of  unstrialed  but  of  striated  lihrt«  like  thon  of  th« 
skeletal  muscles. 

In  a  veriif-nl  aeetJon  of  the  «tH>phat;us  it  will  be  seen  that  the  epithnliuoi 
is  aot  arranged  as  a  single  layer  of  cells,  but  is  several  cells  deep.  The 
lower  oelb  near  the  basement  membrane,  which  is  not  very  distinct,  are 
cylindri<:al  or  spheroidal  cells  with  granular  "  prutopWmic"  cellsutwtanoe, 
hut  tliiiae  nearer  the  surface  are  more  flattened,  and  the  uppermost  cells  are 
mere  llattene<l  nucleated  waU^,  the  bfidies  of  which  are  no  longer  prato- 

f'lasmie  but  have  become  changed  iniu  a  jieculiar  material.  Such  an  epitbe- 
ium  is  called  a  "Airiiiiritnl"  epithelium.  A  nimilnr  ejiithi-lium  lines  the 
greater  part  of  the  pharynx  ami  the  month,  and  \k  conlinunu.H  with  the  cor- 
Rfponding  epithelium  oi'  the  Kkin  or  " epid^-rmiit "  of  whi>'h  Me  .-vliall  fauve 
to  speak  later  on.  At  the  cnnlino  nrificr  ihure  is  a  unddrn  tnitiiiitioo  frum 
this  xtraiifiei)  epithelium  to  the  gastric  epithcliutri  previoiisly  rlc^crilied. 

The  loii*en««<  uf  ihr  ■ubmuous  cnat  rKtmiitx  the  mucous  nicnibmiie  to  be 
thrown  iniii  temjKirurv  longitudinal  folds  which  disappear  when  the  caiuil  ts 
dinleiMled.  But  lj(«i(i<v  this,  the  line  of  The  bnsement  monibmur,  of  the  con* 
nedivc  tiwuc  liunis  of  epithelium,  "dermis"  or  "  cormm  "  as  the  correspond- 
ing part  of  the  skin  is  called,  is  raised  up  into  a  number  of  permanent  coni- 
cal clevulions  or  fmj'ithr.  in  which  the  conneclivc  tissue  is  (Specially  Hue  and 
and  which  are  nchly  provided  wnth  bloodveseels.  The  surface  line  of  the 
epithelium  docs  not  follnw  the  inc(|ualiiiee  ot  the  dermis  proiluc«d  bv  these 
pRpillav.  but  remains  Airly  even.  In  the  presence  of  this  papillw  the  mu- 
cous membrane  of  the  (esophagus  also  resembles  the  skin,  but  in  the  latter 
Blnicturo  the  papillie  ar«  more  atuiudaut  and  more  regular  in  form  and  siKe;. 
The  dermis,  or  connective  ti^ue  basis  of  the  epithelium,  is  a  network  of 
Gbres  and  fine  bundles  of  euunectire  ti.-ctue,  with  connective  tiMue  corpuaclea 
ami  a  cuDbiderable  number  of  flitc  elantic  lihre*;  tbe  number  of  leuoocytea 


m 


TIIK   JiTHL'CT 

tiinbtv  of  itip  iH-in<itlc  u  ix'lutiv<<lv  >cnniy.  A  fw  >ciit(orcil  nuiMM 
f'lrni  ur  niltriiiiiil  limiii*.  of  nhidi  no  oUitll  ^iciik  liitor  od,  ooctir  li«rt' 
■ndlbera. 

TW  nneotw  iii«'nihriiti«  proper  is  defitwd  from  lli«  undrrljriDe  ruI>riuixiui> 
time  l>*  ■  iniiM-iilurU  miicoHP  of  pUiti  anMrialed  niuM-'ular  fioree.  Iviiig  nl 
•rail*  diaUnci-  from  itie  ejiiiUeliuin.  Tbne  rouwutnr  fibres  are  alMciit  «t  t)H> 
Bpfirr  i«rl  of  the  cEaophaeus,  a|ijJi-iir  lower  down  in  uulated  longiluiliDs) 
MDclln,  «ii(  nronlusliy  &rra  a  <Iiatii)rt  Inyer,  whiuli,  bonvrer,  is  ni>l  to 
r*gnW  H  in  tlw  rat  of  ibe  alimi-titAry  <!aiiiiI.  an<l  rotiiitU  of  lonj^iludiniil 
Ghrrc  only,  cir^-ular  fibres  beittg  nbuniu' 

Id  duui  «  few  liu(  iu  ullirr  aiiimsia  n  ciuifirl  era  lilt-  iiiimlier  of  small  '*  mti' 
cmh"  snd  "fllliiimiiioii*"  gland*  nrt  Cwiad  ill  tlw  subinutious tissite :  their 
duals,  (wnciniiini;  tbi>  miwi-ulsrie  miRinie  vbcrr  pmmt,  opeo  on  to  the 
•urfcer  »f  the  niunMi»  mrmbmoet.  In  mnn  iind  maiiiinnlia  ibeoe  it'an<k 
■pp««r  Itt  »ervc  nuly  the  purpose  of  kecpinji  ihe  iiitemiil  mirfaee  of  ibo 
mopbami*  moid ;  hut  in  Mine  aniiiiale.  a«  in  the  fro|;.  i»  which  th<^  epilhe- 
thm  nf  tlw  (nophnL'iii  is  not  the  mnny  layered  almtitied  enitlicHuiii  JuhI 
4aRri1>rd,  hut  n  ciii);1e  layer  uf  eoluninaV  eijinii'd  cells  iiiii<Mi  with  muctiUS 
ealW.  uf  the  kind  nhicli  w^  shull  later  on  deMrribe  m  "goblet  "  c«ll*,  there  is 
a  Urgv  dnvlopim-nl  of  ;;]nnds  at  th«  lower  pari  uf  the  oesnphaguv,  nod  the 
eHb  of  lh«w  glandf  nMiuuruciun!  pvpin. 

.K»  in  'ither  parts  of  tlte  alimentary  iiinnl  the  *iihim)cotis  tiam«  ciirri<9  the 
larscr  hloiKkeMelB  whose  smallL-r  bmHchc*  riippiv  the  raueous  tncmbriine ; 
aM  lymphatics,  beginning  in  the  lotirous  memlirBn<',  fumi  considtfrsble 
plexuNv  ID  tlie  Bubmueoua  coaL 

i  222.  In  man  Uiih  the  ihtcker  inner  circtdar  nod  the  oiit«r  thinner  loii^- 
tndtiuil  muscular  laver  <»nfin  in  lh«  up)>or  part  of  the  <ewi>nhagus  eielii- 
iiifly  of  bundles  or  strtiiiMl  lihreu.  wliich  in  their  main  cnancters  an> 
idc«t*r«l  <*ilh  nnliiinry  Rhres  of  skeletal  tiiUHeles.  At  about  the  end  of  the 
opprr  third  or  rauner,  bundles  of  plain  uii^triiitcd  fibre*  make  (heir  appear- 
kbce  amoDg  lbs  bundles  of  alriat«l  fibn-x.  and  a  little  tower  down  the 
striated  flbna  disappear,  to  that,  In  the  li>wrr  half  or  nior«  of  the  tube,  Wh 
rirrular  and  li>nf[iiudiiial  Isyerx  are  compownl  idmoil  exoluiively  >>f  plniit 
ni»lri*[<i|  lib  res,  a  few  itmy  bundlni  of  Kriat«d  muscle  heiag  loond  hvre 
•nd  ibani.  The  relati>Ki  of  the  «trinl>.il  and  umlriuli-d  fibres  dilleis.  Ix'W- 
rwr.  In  diflS-rrat  animals;  in  sfmie  the  st(tiiie>l  tioiue  raaehesduwH  ncjirly 
to  iW  Mnt»Bi-h. 

Above,  both  iMigitiidiiwl  and  drcular  Inyere  merge  into  the  inferior  con- 
atridor  of  ibe  pharynx;  Iwlow,  the  lon^tndinnl  bundle*  spread  out  in  a 
fwttsl  ftshioD  (o  joiD  thv  corrttspondiuf;  Ionj;itudiuiil  niuKulnr  iHHit  of  the 
stosnaeh,  aad  the  circular  fibres  are  also  continuous  with  thi' circular  and 
vbOqat  layen  of  ibo  stomach,  more  especially  with  the  latter.  Before  the 
fimtUr  fibres  idw  apreml  out  over  Ihe  ttomaeb.  Ibey  undergo  a  tunievrbst 
iDpri»td  development  formiuK  >>  *"rt  uf  sphineter  of  (l>e  rurdiiic  nrifit'e. 

OnCsidc  the  longitudiuul  niunrtilnr  m>«I  of  the  aw»pha;;u^  iher^  is  a  oou- 
Marable  develupim-nt  of  ciinn«^-ti\->'  liwui-  fimning  what  is  tometiroes  spokeu 
of  aa  a  fibruu*  slteuth.  In.  or  mtln-r  |MThii]iH  »n,  this  sbeath  in  thr  |f>wer 
part  of  tba  CFa(M>ha)[us  run  the  two  i-stfi  niT\'<«.  with  the  miophaireai  pU-vus 
■  hieh  is  furnml  by  branchi-*  ruiming  from  llw  one  to  the  otiter.  In  it  also 
nin  the  larger  bliMKlrnwIa. 

t  2S3.  It  in  obviouH  ihni  (Im  ivsophaetis  is  much  more  a  muscular  than  a 
Hotting  slrui-ltire,  und  I'liiiher  thai  a  Ji»tiui?ti<>n  t*  to  lie  modi'  hi-twfi-u  ihe 
apfKr  [art  "f  the  (i-*"jplingun  wIhtc  ihi'  niuEcnliir  tihr«  an*  »triiil"i.  and  llie 
lowrr  part  wbeif  llwy  arw  unflrinicd.  Corresponding  more  >ir  if"  clearly 
to  this  distinrtkon,  «c  find  that  though  the  «hul«  osuphagun  it  supplied  bj 


i 


SS2        THK   TISSFE8    AND    JTECffAyiSMS    07   DTOBSTFOJT. 

nerve  libres  from  ihe  trunk  of  ilii;  vajiua  (n'tiicli,  however,  it  must  be  remem- 
bered  coiitainH  besides  fibres  of  the  v>i|;im  propur,  Rbrea  ttata  the  apinsl  ac- 
eavoty  wcrve  and  from  other  source*)  the  aiip]tly  to  Ihe  upper  ]iari  takes  a 
diReifiii  courae  from  ibe  supply  to  the  hiwer  part.  Thiu  id  nuui  tlw  upper 
part  is  siiii]>lied  by  branches  of  Lb«  recurrent  liiryngeiil  nerve  ta  it  runs  up 
between  the  trachea  and  OMUphoKUK,  wbilo  the  I'>w<t  {wrt  derives  iu  nerve 
fibres  from  the  iUKi|ihaKe»l  ploxu*  formed  br  tJio  two  vi^ri.  In  varinua 
aninialK  tbi?  supply  uf  the  upjirr  purl  viiricn,  eiiminK  in  tu>nie  cuea  chiefly 
fraiu  the  phtirynK^iml  hrnin-h  nf  thv  viijeii*.  atxl  being  in  tbn  rnbhit  a  dittincl 
branch  nf  the  vnpi*.  hi  all  vn*v*,  however,  it  notild  M-eni  llmt  the  Inni^r  p«rl 
of  thv  inDphagiis,  the  up[>er  limit  bein^'  plitced  higher  <ir  lower  in  dilfiTent 
animals,  is  supplied  I'min  ihe  (pnophngiiil  plexus.  Il  mny  be  ff^nmrked  (hat  th« 
fibmi  in  this  pkxne  arc  for  ihf  mom  purl  non-niedulUteil  fibres,  but  wc  -hall 
have  to  rvtiirti  tu  tbeiie  nerve;^  in  !>]>eAkinguf  the  movomeni«of  the  oimphuguM. 


Thi:  Act  op  Sgcretiok  op  Saliva   a:cd  GAffrnic   JotCB  asd    tbk 

NkRVOI-^   MEDRANIHMit   WRICR    ReOULATR   IT. 

!;  SSI  The  saliva  and  gastric  juice  who^  properliist  we  have  studied, 
thouch  »o  dilTereiil  from  carJi  other,  are  both  drawn  ultimately  from  one 
common  source,  tbu  blotHl,  and  they  am  rKiiircd  into  Hic  alimentary  eanal. 
not  in  a  ountinuuus  flow,  but  intermittenLly  a»  uccaaton  may  demand.  The 
epithelium  cellii  which  nupply  ihem  have  their  {leriods  of  ravt  and  of  activily, 
and  the  amount  an<l  <pialitv  of  the  fluid*  which  ihoto  cell*  aMrete  are 
determined  by  the  need*  of  the'eCDUomv  n»  the  food  pasws  along  the  eanal. 
We  have  now  to  e.on»ider  bow  the  epitWliitm  cell  maniifnctum'  it*  vpecial 
Mcrctioo  out  uf  the  maleriald  supplied  to  It  by  Ihe  blood,  and  how  tlio  coll 
ia  called  into  activity  by  the  presence  of  food,  it  may  be  aa  in  the  case  of 
saliva  nt  some  distance  from  ilaelf,  or  bv  circnuuitMiOM  which  do  not  bwir 
directly  on  itself.  In  dealing  with  the^e  matters  in  connection  with  tJw 
digntive  juices,  we  sliall  have  to  enter  at  some  length  into  the  physiology  of 
aeeretion  in  general. 

Tbe  queslion  which  prceeiilfi  itself  flrel  ia:  By  wlial  laeohanism  b  the 
aclivtiy  of  tbe  tecreiiug  ccIIh  brought  into  play? 

While  fluting,  a  iinall  ijumitity  only  of  saliva  is  jmured  into  the  oioutb : 
the  buccal  cjivity  i*  just  moiat  luid  nothing  more,  When  food  Is  taken,  or 
when  uny  napid  or  slimuluting  ftiibmaucv.  or  indeed  a  body  of  any  kind,  is 
introduced  into  the  mouth,  u  How  i*  induced  which  may  tw  very  copious. 
Indeed  the  mianiity  necreled  in  onlinary  life  during  '24  houn  hai  been 
roughly  ealculattyl  at  lu  much  a«  from  1  to  2  Hitri.  An  ahuntlant  McretioD 
ill  the  nhitenee  of  (bod  in  the  mouth  mav  be  called  forth  by  an  emotion,  aa 
wbeui  the  mouth  wniern  at  the  «ght  of  fooil.  or  by  a  nmull.  or  by  events 
occurring  in  the  stomach,  a*  in  immc  cumw  »t'  naus<-a.  Evidently  in  iheae 
inataneee  some  ncrvoiii  m<.'ehani«m  i»  at  work.  In  studying  the  action  of 
this  nerruiif  mechani*m,  it  will  be  of  advniitiigv  to  confine  our  attentiua  at 
fint  to  the  aiihuinxilliirv  gland, 

$  SSS.  The  uibmaxilliiry  gland  is  supplied  with  two  set*  of  ncrvM.  These 
are  represented  in  F'tg.  lOt,  which  is  a  very  diagrammatic  reuderitig  of  the 
ap|>cHninc«s  presented  when  the  aubnuixillary  gland  is  preparoit  tvr  au 
expt-nmuiil  in  a  dog,  the  animal  being  pliiced  on  \l6  back  and  tbe  gland 
exposed  fnni  tbe  neck.  The  nnv  Act,  and  that  the  more  imp<>rtsnt.  belongs 
to  tbe  cAordu  timpani  nerve  (ch.l."  ).  This  U  a  small  nerve,  which  branches 
ofl  ftooi  the  facial  or  seventh  cranial  nerve  in  the  Fallopian  canal  before  lh« 
nerra  isBuee  from  tbe  skull.     Wivitiber  it  really  betougii  to  Ihe  facial  proper 


AEUBITIOX    or   SALIVA    ANIi   O.VSTBU'   JITICK. 


uarlio 


oomilig 


Art 


•a  (kmbtvtt :  in  nmn  iIk-  fihrm  which  r<'rin 
m  tb»  root*  »)'  ttii:  fkrwl  pmpvr  btit  Croin 

m,  nr.  «coonJiD^  Ui  maw,  lilirc^  which  tbixigli  joining  tliu  t'iK'inI  in  lh« 
FKliolMJin  {«ii«l  Bra  ultinmiflv  Hrnvcd  tnim  aii'ithcr  ^(liv  Kllh)  i-rnniiil 
metyr  Lr«Tiii|!  the  fm-inl  nirvc,  thp  chonlii  lynipiini  pants  through  llw 
tjiuiiKnic  ixviiy  or  ilnini  of  \hv  rar  (h<^ncv  (he  onnie)  Ui<l  joins  or  mthi-r 
rani  in  00Ba|Httiy  irA.i')  wilh  ihe  lin^'tiid  »r  j^iieliiliirv  hniich  of  tlw  SAh 
Mil  n  Somu  of  the  fibres  run  on  with  ihv  liogunl  riuhl  down  (u  ihe  toogne 
(tk«n  Ut  tMit  »bowD  in  the  ligur«),  bul  tunny  Irave  llio  lingual  as  a  steniler 
ti«m  (ek.t).  which  reaching  Wharton's  duct  or  duct  of  tnosubiDuillary 
fl*aA  Imt.j)  runs  along  the  duct  lo  lh«  gland.  Ab  tli«  nerve  coursea  along 
llw  dun  nerve  cclh  make  their  appearance  omong  the  Hbree.  and  these  are 
iwcially  abundanl  just  aAer  the  dui.-t  enters  the  hilus  of  the  glaud.  'I1ie 
fibfw  mar  Iw  traced  into  the  jtland  fur  eonie  di»ianoe,  but  as  we  have  Aaid 
tbilr  vllimals  endiDK  baa  out  yet  been  defiiiilely  made  out.  Along  icn  whi>l« 
eoniM  up  to  the  giaud,  ihe  fibres  of  Ihe  churdA  are  very  tine  medullated 
fibfw,  but  they  li»e  th«ir  medulla  in  the  gland. 

TW  oihvr  wi  of  nervi^librea  reaches  the  gland  along  the  small  arteries  of 
tba  ^atid.  Tliesc  are  uu«-ni«du Hated  fibres  mixed  vilh  a  few  medullaled 
fibro  add  may  Ik  imreil  ImicIc  lo  rhe  nuiieriur  c«rvii.-a[  itauglinn.  From 
Ihsnn  tbcy  may  be  traced  »till  further  buc-ic  duwu  the  corvioulayitiiiiitbetlo 
M  tbesi^DBl  mn),  rtillimiug  appurcnllv  the  *ame  tract  as  the  raiiu-cunatriclor 
ttres.tnaivduf  in  M)i4>. 

I  tt8.  I(  n  lubv  \tf  pluc-L-d  in  ihe  duct,  it  is  teen  that  when  mpid  >ul>- 
■bUKVS  arc  idaocd  hq  ihc  lungue,  or  ihe  tiiuguc  is  Mtiinulated  in  any  olbvr 
way.  or  the  finguitl  ntrvc  i>  laid  Iwrc  ami  «limulntcd  with  nn  inlcrrupted 
ct)ttt«(,  a  <>>)>tuu*  tlow  <jf  Mlira  tuko  phic«.  [f  ibe syniiiatln-ttc  be  dividi-d, 
atinulatioa  of  lh«  tongue  or  lingual  m-rve  niill  produces  u  flow.  Bol  if  the 
■nail  clKirtla  nerve  be  divided,  stimulation  of  the  tongue  or  lingual  nerte 
pradttcn  do  flow. 

Ciidently  the  flow  of  saliva  is  n  nervon»  reflex  action,  the  lingual  nerve 
HT^ing  sii  Ihe  irhaiinel  for  lh«  adt-rent  and  ihe  small  chorda  nerve  for  the 
tffuCDt  iniiMilscs.  If  the  trunk  ut  the  lingual  be  divided  above  the  point 
■ban  Uie  eboTda  leavM  il,  as  at  n.f.  Fig.  lUo,  stimulatioD  of  the  (front  part 
of  >  tongue  [irodncee,  under  ordinary  circumstances,  no  flow.  This  shows 
that  the  ccnttv  of  the  reflei  action  h  higher  up  llian  the  point  of  section ;  H 
lias  in  bet  in  tlie  brain. 

In  tbc  angle  betwcoi  ih«-  tingnal  and  the  chords,  whero  the  lattsr  leavve  the 
fiWIBSV  to  pass  Ui  tbc  ^liind,  lira  the  oiisll  Kubmsiillsry  ipinglion  (rc)ir«^nled 
dli^^BiiBalically  in  Fig.  I<r>  an.yl.).  Thia  ciinsUtji  ornmall  nmises  of  nerve  culls 
Ivinf  "n  ib«  niiall  buadin  uf  nerve  fibren  which  apreail  out  like  a  fau  from  the 
ItDcual  anil  chorda  tyin|>anl  nervM  (cA.!.)  lowsnl  the  diictAof  tli«  Hibcnaxlllary 
and  sublingual  gtalxu.  Il  biu>  bevn  much  ilvbuicd  whetbrr  thi*  gnnffltoD  can  avl 
■a  ■  <'rDii*  of  rrSez  action  in  cxinei'tiim  with  Ihe  aubtoasillary  gliuid,  bul  no 
eonrluuve  cridcDce  that  il  does  wi  aot  bte  as  yet  been  abown ;  It  probably  belong* 
In  ri-ality  to  the  MiUmeual  gland. 

Stimulation  of  the  glofaujtharyiigonl  is  even  more  cflectual  than  tliM  of 
the  lingnal.  Prol>ably  Ibis  indetxl  ii"  tin-  chief  alB-rwit  nerve  in  'irdinnry 
arcrvtiou.  Stiniulatiou  of  the  mucous  menibriuie  of  iIk;  Momacb  (m>  by  r<H4| 
iatrt>(luc«d  through  a  gastric  fislnln)  >'r  of  th<>  vugu*  rosy  aim'  pnxluiv  a  ll<>« 
ofBallvB.!*  iiidwd  may  ftimulalioJi  of  the  sciatic,  and  [itoluibly  "f  many 
other  afferent  iwrve*.  All  tlieso  oosos  an  insiauu«  of  reflex  acliun.  Uiv 
oerebro-spinal  syetem  acting  as  a  ceatn^  Wc  may  further  define  ihe  ccnirv 
as  a  pait  of  tbe  medulla  oblongata,  apjiarentlr  not  far  retnoveil  from  llM  vaso- 
motor  centre.     When  the  biain  is  removed  down  to  the  medulla  oblonguta,. 


884      THE  TissrKs  AKD  UKcn\irtsvs  or  digestion. 

thntor^'flii  li^iiit;  IcftioUcl,*  dgWofiMiIiva  inavaiill  l>col)Uii>ed  byid«quBt« 
iliiiiiiliilioD  of  rnriniiii  nffi'roiil  iMrrvn ;  when  (Im-  moiiiilla  i^deMroyed  no  audi 
aciion  i»  p')wil>K-.  Anil  «  How  of  mlivn  niiiy  be  jtr<Kl««t)  bv  ilirvct  slimul&j 
tioii  or  lti«  (ikhIuIIii  icmII'.  Wlico  it  Dav  of  «iUva  ii  oxoiKNl  by  i'teaa,  itr  b^ 
emotions,  t\w  norvous  procwen  l)egiD  in  the  bigliur  |>iirt«  of  tiw  brain,  ami 
deMond  thenoc  to  the  mcdtilln  bcforo  th«y  pin  riM  Co  di«tiiictlr  cflcreui  im^ 
pulM>:  Mill  it  u'oiilij  a|i)wtir  llinl  lliew  hi);'i«r  parts  of  the  brnin  are  C*ll< 
into  actioii  wh«D  a  Bok  of  mlira  is  excited  bv  distiuct  MiuMitiuna  of  tiiM«. 


Pn.  Itf. 


.  W-MnA 


K.t}f0,f 


nZ 


it.*m.m. 


Jdt.dt 


:?5s* 


nW' 


-*m^ 


.  mX 


V^ 


-1./^' 


DtiURAiiwiTW  KnunRfTATioi'  oT  ni  HuaKixiM.tHi  UWNi>  ur  THB  I><M.  wtTii  m  Nun*  4yi» 

Th*  dUMVlKHI  hat  bcvn  niatle  eu  an  animal  tyliis  nn  lu  hack,  bHt  dnw  all  Ih*  pan*  Bhtmn  Hi  I 
ncnncouinaltvmn ftumauyoDfiDlniof  vIcK,  ibcncurRiOoaTiat ginUicuaiHaiiaiiimtcaliali 
IMn  or  Itw  tnranU  nmotun*. 

w^fM.  Tlw  nlbmaitllaiT  Iknd.  IiiId  ■lioiliicl(Bi.if.i<il  wlilnli  a  lanula  ba*  lc*n  Ileal,  TMiuIh 
IMisual  viand  an-l  •liiit  art  uot  ikimn,  ■J..H.r  Tho  IliiRUal  blanch  of  iho  Dltli  nunv.  iliv  tan  aJ. 
It cti'KS  U til*  ■"■iRUg,  rA.r.fA  I*  .cA.r.Ttui'notda  l;in|aiil,  Tbn  lortiA.I'',  Ih  imnKiliiiii  m<inllie 
IWtMl  iwm  :  al  rk  I*  II  Ivmni**  ronjolimt  Hllh  Ihp  IlniiiwI  B.l.and  anerwanl  dlioiglnc  |iiiiaia  aa 
r>.(.  tolbeiilaiirl  alunic  iliciliicl ;  Itw  CDDtlniialJuo  of  ib<  ni-nc  lu  oiiutany  vMh  Iht  UiiHiial .  ■<  ,  ta 
D-il»linwii,  m.  y,  The  nuliinixlllary  (anrtli'n  wUli  )t>  •mral  Rnit,  u.mr  Tbe  arellil  uMty,  la 
(iiiall  branvliwoT  lahltfb,  n,  is.a,  uiit  r.  ni.p..  |>ui  t»tt>(  anlpniiran<l  imlcrtor  lamaof  ItMgb 
f  m.TtuBnttriuralHl  pcaUtli>r  Tttnt  (Rna  lt>Fulaii<l.  falUiiK  liilo  t  J.,  tbc  JiimitaT  ntn.  ■>««M.1 
funjiitiml  t-AfXK  anil  »}riii^llivUc  Iriifik*,  (r  rrr,  r  TIw  h^il**!  ti-n'IniJ  gaiiftlun,  tW4  Tiran^'li^  t 
wbkli,  FijnDliis  a  piriu*  In./ 1  nvn  Ihp  (Mlal  anvrr.  an  dlilntiutol  la  iyiii.n(.i  aluiig  ilw  la 
(UiMlvlar  annlef  lo  (iLe  anurior  and  pxlcdiii  iiur(li>i»  •<!  ilie  Ktaml. 

Ttwamnra  lodlnta  tha  rllfucUfiii  laivi)  by  Itir  Titrrvun*  liiiinLltn*  ■liLr^iif  nilex  tUinulalloii  nflll 
Klaod.    TlMT  ammd  to  Ih*  hnin  t^r  the  llUfual  anil  dcawiul  bj  Ihc  chorda  tjrmiauil. 

Con«d«ring.  thon,  tlic  Row  of  aaliva  am  a  rofl«x  ac^t  lh«  centre  i>f  wbii^J 
lies  Ul  lh«  iiimIiiHii  oblongata,  wo  may  iinHgin<>  tlie  efTcreat  iR)i>ut»(«  paMiig] 
from  tluit  mitre  to  tlie  gland  eilber  by  tbe  chorda  tynipeni  or  by  tli«  ayni* 
]>athelic  nerve.  Although  il  nould  perhajK  be  raah  to  ray  lliat  iu  thii 
relation  llie  §yni[>alhetic  nerve  never  acts  aa  an  elfereiit  channel,  u  a  miillvr 
of  ftcl  Vfe  have  no  aal»r«clory  experimental  evjiieiice  that  il  does  wi :  and 
vte  may,  iherefurc.  Male  thai,  praciic»lly,  the  chonla  tympaoi  la  thir  hoI« 
e-flereiH  nerve,  .Seolion  of  that  nerve,  either  wliere  ihi-  librea  \m»  fmiu  the 
liugnal  nerve  and  ike  submaxillary  ganglion  to  the  gland,  ur  where  it  nina 


BKCHETIOK  OP  SAXTTA    JiVV  flASTRtO  IVIVB. 


8S5 


in  llxt  itunti'  nh(!«tb  m  tbe  liiigtinl.  or  iii  any  jwrt  of  it*  courac  frniii  tlx-  iiinin 
fncinl  triiuk  i»  llio  liiifriinl,  pufn  nti  tiul,  u»  fur  lu  we  kii»w,  i<i  iIk'  [nMxiliilitj^ 
of  nny  tl»w  being  exrilMl  by  vlimuli  u)i]ilirHl  to  tliu  iHiLsiiry  iii-rvw,  <ir  lo  llw 
aeniknl  surfacra  of  cbe  iiioulli  or  cl'  otln-r  [iiirU  gf  (lio  body. 

The  iiHlunil  reflt-x  ftcc  of  »r(Ttrlii>n  inav  In;  inliibiM^.  like  lb*  rvllcx  iirtion 
of  tbc  vnsomotor  nerves,  nl  iu  cvnlrc.  'fhiiK  when,  nx  iii  tbi>  old  nr«  urdeAl, 
fear  p«rchce  tho  mmith,  it  if  |>mbiLblo  that  ihi;  nflm-ot  iinpulmv  cniiscl  by 
thfl  pnBeDcv  of  food  in  thi;  muiilh  cnw.  ihnnigh  emutioiml  inhibiiion  of 
tbttr  r«S«x  cMitn.  to  give  Hso  lo  fHornit  impuliKv 

S2ST.  Ill  life,  iheii,  th«  tl»w  of  Knlirii  in  bnuigbt  iibiiiit  by  tbc  adveut  lo 
the  gland  along  lli«  cbords  lyinjiniii  of  ctTpri'iil  impulMx,  sUrt«d  chiefly  by 
reflex  actions.  The  inquiry  thuit  nitrrow*  itself  lo  ibc  ipit-slton ;  In  what 
tuuniier  do  ihme  erterenl  im|>iiliM%  caoM'  the  increaiw  of  flow  f 

If  io  a  doj;  a  lube  be  iotroduped  into  Wharton '»  ilurl.  niid  tho  choriU  he 
divided,  tlie  llovr,  if  any  be  going  on,  is  from  the  !ack  of  elfcreiit  inijniliea 
arrtttteil.  Ou  |>aaeing  an  inlemipted  I'lirrenl  ihroiigh  the  peripheral  puriion 
of  lite  chorda,  a  iiipioua  Bccreiiou  ni  oiieo  lakeii  plat^o,  and  the  mHvs  lios;inM 
M  ri»c  rapidly  in  llie  lube:  a  very  short  lime  after  the  applicalt»ii  nC  the 
current  the  flow  reaches  a  uiaxiiniim  which  is  maintatoed  for  some  lime,  und 
ibiii,  if  th«  ourrent  be  long  continued,  gradually  l«weiis.  If  the  current  Ittt 
applied  fi>r  a  short  time  ouly.  ihv  Mention  may  but  for  soiue  time  after  the 
current  haii  Ixien  shut  off.  The  «livn  thu)  ohuined  U  bul  slightly  viKcid, 
nnd  iiod«r  the  iiiieriMciijte  a  rery  feve  Halivary  eor|iuscle>4,  and,  oecuMionaUy 
only,  uatorpbouM  Iiininn  nf  (itxciulinr  luaterinl,  pritbably  iniieoUH  in  naturo,  are 
eoei'i.  If  the  gtiind  ibvlf  Iw  watched,  while  its  activity  in  thun  mused,  it 
will  he  see:i  ^a*  w<-  have  alrvadv  ituid,  ^  l«'>7  <  thai  its  arUrlea  nro  dilntod,  nnd 
its  uipilltiri<«  lilli.-i'I,  mid  (but  the  IiIimkI  flows  rapidly  thnm^h  tho  veins  in  a 
full  Hrenni  anil  of  britrht  arli-rial  hue.  friviue:illy  n  illi  iiviUnlltig  niovoineiita. 
If  a  vein  of  the  ginnd  In-  o{)r-iii-<l,  llii*  largu  iiiereatu!  of  flow,  and  (bo  learn- 
ing of  ll»e  onliniirv  d^-oxygt^iiiitioii  ^tf  the  blood  coiuo<|ui.'flt  upon  the  rapi<) 
atreaui,  will  be  dill  more  •.-ividenl.  Il  i*  clear  (bat  cxiilation  of  tlie  cborda 
lart^ly  dilates  the  arlerio :  tbe  iiervr  acW  energetically  as  a  roao^ilator 
nerve. 

Tbns  etimulation  of  the  chorda  hringK  about  two  events :  a  dilation  of  the 
bloodvMwb  of  the  gland,  and  a  flow  of  ealivu.  Tbc  'lUMtiou  ai  once  ariaee, 
la  the  latter  siinnly  the  result  of  the  former  or  is  the  flow  caused  by  HOiae 
direct  aclion  on  ihe  secreting  cells,  apart  from  the  increased  blood-supply  f 
In  tupjiort  of  the  former  view  we  might  argue  thai  (be  activity  of  tlie  epithe- 
lial Kocreting  <^-ll.  Iik«^  that  of  any  ikiher  IbrDi  of  proloplanni,  is  dependent 
on  blood -Mupiily.  When  tlie  smalt  arteries  of  the  gland  dilate,  white  the 
pnMurr  in  i)ie  arteriuon  the  side  toward  the  heart  is  i  as  we  have  prvviouitly 
jiMD  wbtrn  inraiing  generally  of  blood-pretsure  !i  l:fO)corr^j)oQdinj{ly  diniin- 
bkad,  tilt:  prvwure  un  lliv  far  side  in  (be  capillaries  and  veins  u  umr-aned ; 
brae*  tlw  (uipillarieii  become  fuller,  and  more  blood  pas«ai  tbroti^Ii  thera  in 
a  ^ven  time.  Prom  this  we  mi^ht  infer  ilmi  a  larger  amount  of  iintritivc 
nialttrial  would  \>nii»  away  from  lh«  capillaries  into  the  .lur rounding  Ivmpb- 
«plH(M.  and  Ml  into  thi*  epithelium  celU,  (he  resiill  of  which  would  imlurnlly 
M  lo  <|iiickcn  the  priKcwivi  goiuft  on  in  tint  ivlk  and  t<i  stir  Uhsm  up  to 

Sealer  aolivitv.  But  even  iiiinilLlini^  nil  ihi.i  it  iIinii  not  ncoemnrily  follow 
at  tbe  arlinty  thu^  cKi-ikHl  should  take  on  the  form  of  Kerrftiou.  Il  is 
quite  puwible  to  conceive  [lint  the  inttnmird  lil<H>d niipiilv  thoiiM  |«ad  ontv 
lo  the  aooumulntion  in  thi'  ii-ll  of  ihe  const i (urn bi  ol  the  saliva,  or  of  ilic 
raw  nuileriala  for  tk-ir  nim^tnu-lion.  und  not  to  a  dimbnrgc  of  ihc  MiTctioii. 
A  man  worhs  hotter  for  iieing  fed.  but  feeding  dots  not  niiiko  him  WDrk  in 
tltc  abeoenoe  of  any  stimulus.    The  incroMwd  blood.«uptily,  therefore,  while 


ZBd 


TDK    TISSL'KS    AND    HKCRANISMS   Of    DIGESTION. 


fitvorabli*  (o  nctirr  wcirtioii,  aixd  tiot  DOccnMrily  briDv  it  Rboiit.  Moreover, 
the  following  liu-U  ilifiiiiclly  thow  thnt  it  ami  not.  WWn  m  cunula  >•  tkd 
inlu  (he  ihict  imd  ihc  L-hoi'<l:i  kcncrgrtieiillr  HlimiiliiU^,  ihc  prnmirc  acquired 
by  llie  saliva  ntciimiil/tteil  in  tlic  cuniilii  uiid  iti  (lir  liuct  muy  citvol  li>r  tho 
time  beiiiK  the  nrlcrini  blDod-pmsiirc.  even  tbut  <if  tliu  ciirutid  nrt«ry  :  thnt 
id  lo  «ay,  Ihe  piv(>euiv  of  tluid  in  the  glaiid  uiit»ide  tho  bl(>o<lv«M(>)8  w  ercntvr 
ihau  that  iif  tli«  blomi  iiiftide  the  blooilvemcltt.  This  inu«t,  whatever  Ixr  lb« 
exai<l  luoiie  of  traneil  of  nutritive  nialcrial  ihroiigh  the  vascular  uhIId.  lend 
lu  cheek  tbut  transit.  Again,  if  the  head  of  an  animal  be  rapidly  eut  off, 
ami  the  obordu  immediately  eti initiated,  a  flow  of  saliva  takes  place  fnr 
tiHi  copious  to  be  aeeiiiinled  for  bv  the  emptying  of  the  iialivary  ehnnnels 
thruUKli  any  *iip[iotM-d  c:i)nlrauti(iii  of  their  walls.  In  this  ease  wcreiion  is 
excited  in  the  gland  though  the  bloodaupply  is  limited  to  the  small  quaulity 
Htill  miiaining  in  ihv  bloiHlveaselti.  I^anlly,  if  a  small  ouaulity  of  airopiite 
bi;  injected  inlu  llie  veiiu.  stimulation  of  the  chorda  produces  Do  secretion  of 
saliva  at  all,  thuiigh  the  dilation  of  the  bloml vessels  takes  place  as  uxual :  iu 

?iitc  of  the  greatly  increuited  bloiHl-«u pjily  no  secretion  at  all  lake*  plftc«. 
hciH!  fiii'ts  prove  that  the  seeruiory  activity  is  not  simplv  the  result  of  vas- 
cular cliaiigni,  but  may  bo  ealk-il  forth  indvpciidenlly  ;  they  further  l«ad  as 
to  Kiip[H»o  that  ihv  rhonia  o<iiitaiui>  two  m-T*  of  fibn«,  otie  which  we  nuiy  citll 
SGcrt'tory  lihm,  acting  <lirr('tly  im  the  MciTciing  flrueturv!)  only,  and  tlto  other 
vtUD-dilntor  tilire*,  seling  on  the  hloridvnaoln  only,  nnd  further  that  atrupiiic, 
while  it  hiw  no  cHi'Ct  on  lh«  latter,  paralrn'^  the  former  jum  an  it  paralyses 
the  iuhibilory  fibrvs  of  the  vnEU».  Hence  when  the  chorda  is  rtimulHtc<l, 
there  |)as<'I<iwn  the  nerve,  in  addition  to  impulmw  aRccting  the  bUMMlfiipnly. 
impiilecf  nKectiug  direelly  the  protoplasm  of  the  Kicreting  cells,  and  calling 
it  into  nction.  just  as  similar  inipiiUcx  call  into  action  the  contnictility  of  the 
subslanoe  of  a  niUHciilar  fibre.  Indeed,  the  tno  things,  wcreting  activity  nnd 
CODtraciiDg  activity,  are  very  parallel.  We  know  that  when  a  muscle  con- 
tracts, its  bloodv»sela  dilate ;  and  much  iu  the  same  way  as  hy  atropine  the 
tecreiiiig  uetiou  of  the  glaud  may  be  isolated  from  the  vascular  <lilntio«i,  so 
(iu  the  frug  at  all  evenUi  bv  a  proper  dtjee  of  urari  muscular  voDtm<!tion 
may  he  removed,  aiiil  li<tive  dilatiua  of  the  hlniKl vessels  as  the  only  effect  of 
stimulating  the  mu.ienlar  nerve.  In  holli  runtA  the  greater  (low  of  IiIockI 
may  be  mi  udjiivant  to,  hut  Is  uut  the  «xeitiug  cause  of,  the  nativity  of  ihe 
structure*. 

Since  the  chorria  nets  thuK  directly  on  the  secreting  cell*,  wc  should  «xpccC 
lo  find  an  anstoniical  e<>unecli<in  between  the  edls  and  the  nerrtt*.  and  UIM 
Bulhon  hrivc  nminlaineil  thai  the  nervc-tibrcs  may  be  tracwl  into  the  «.dls. 
Bui.  *nvv  ncrbaps  in  ihc  cbw;  of  ccrlnin  glnnils  of  invertehrat«  (si>-nilled 
salivurA-  glamls  of  Ilhtta).  iho  evidence  as  wo  have  Niid  is  as  yet  not 
CouvinrinE!. 

i  S&9.  \Vhi-n  the  cervical  eympnthelic  is  stimulnlcd,  the  vascular  effectB, 
as  ne  have  ulrendy  Hiid.  ^  ItlX,  are  tho  exact  conirnry  of  tliutw  seen  when 
the  ehiirda  is  Mimithiled.     The  small  arteries  are  eoustricted,  and  a  small 

auaiitity  of  dnrk  vcuou*  hlowJ  escapes  hy  the  veins.  Sometime*,  indeed, 
»e  tlow  through  the  gland  is  almost  arrested.  The  sympatlietic,  therefore, 
acts  as  a  vssa- constrict  or  nerve,  and  in  this  sense  is  autagonistic  to  Ihe 
cborda. 

As  eoncems  tlie  flow  of  saliva  brought  about  by  stimulation  of  the  sym- 
polhetjc,  in  tite  ease  of  tite  subma.\illary  gland  of  the  dog  tlte  eAbda  are 
very  peculiar.  A  slight  ilow  results,  and  the  mdiva  so  secreted  ia  remarkably 
viscia,  of  higher  specific  gravitr.  luid  ri<'ber  in  ourittiielcs  and  in  the  above- 
meulioned  SNiorphous  lumps  tWn  is  the  chorda  wlivn.  This  action  of  tlM 
STui|ittthetic  is  little  or  not  at  all  aflecl«d  by  atrt>]ri»e. 


SXCBKTION 


Attn  0A8TI11C  jnici. 


WT 


^ 


I 


Ib  Uw  tnbnuailbry  glnnd  uf  the  <k>g  iheii  tliv  ctinlnm  between  the  elfecta 
of  ehonbt  tUiDiiUlioniini]  thoecof  eympnlheiic  »tiiiiiilatian  are  verr  nmrke<l ; 
tlw  forawr  civn  riM  to  Ttt#ciilar  dilntion  with  u  co|iioii»  dow  of  fairly  limpid 
■■livs  poor  10  •olids,  ihe  lalter  to  vasculnr  eonalrictiou  with  a  tcaniy  duu'  nf 
viacid  mHvt  riclier  id  aolMs.  And  in  nllici-  anintals  a  similar  coulrsst  ni«- 
VBib,  tbuugli  with  minor  diSerencw.  ThuB  in  the  rabbit  both  chorda  Mlivft 
mad  tTrnpfttbetic  aaliva  are  limpid  and  free  from  mucus,  thouj-h  the  tatt«r 
oDolauM  man  proleitb;  in  the  cat.  chorda  aaliva  it  more  viaeid  tliau  xympa- 
thelicMllva;  but  io  buth  tlMse  cases,  as  in  tb«dog,atiniuIatioD  of  the  chorda 
cum  n  cnpiouH  flow  with  dilated  bloodreneb,  and  stimulation  of  the  aym- 
palbetic  a  acanty  Son-  with  vascular  couairiction.  We  ahall  return  Uf^ain 
prcMDtly  t(>  iheM  different  uciiuna  of  the  two  nervce ;  meanwhile  we  linv« 
Men  enough  of  the  Iii«tory  uf  the  aubmaxillary  gland  to  l«atn  that  »evretiun 
ia  tfab  inotance  ia  a  rettex  action,  llie  elTerenl  impulsea  of  which  din-ctly 
sflkct  tlte  ■Nreting  cell*,  and  iliat  tlie  viisculur  plienomena  may  awiat.  but 
an  Dol  the  dinct  caiue  of,  th«  flow. 

(  SS9,  W*  have  dwelt  long  ou  thin  j:\unA  l>ocau*e  it  ha«  b«en  more  fruit* 
filU;  attidicd  iban  any  other.  But  the  dltvoua  niet-linniama  of  the  other 
MliTftn  clanfU  are  in  their  mtiiii  fmturm  similar.  Tbii*  the  •ecrtrtioti  of  the 
pwvtiil  gland,  like  that  nf  the  Hubnmxillary,  io  governed  by  ttvomitiiof  libnv; 
uov  of  rerrbro-cpinul  ori^ii,  niniiiii^  along  the  auriculo-tvuijionil  branch  of 
tba  llfUi  ocrvp  but  originating  iiOHsibry  in  the  gto«Mo<ph*ryngcal,  and  the  olh«r 
nf  arm  pathetic  origin  coming  from  the  <^vrvical  »ympathetic.  Stimulation  of 
tba  cmbro-tpinal  fibrrt  nroducn  a  copious  How  of  lininid  wiUva,  free  from 
luuena.  the  tevrvtioii  reaching  in  the  do^  a  pnwurc  ui  118  mm.  mrrcury  ; 
ttinmlatinn  of  ihr  cervical  syni|wthctic  pvv»  riM  in  the  nibbit  to  a  fccrction 
aiK>  fnv  from  miicui>  but  rich  in  ppiCcKU  ami  of  greater  amylolytic  mwcr 
than  the  ccrcbrciHoinal  McrctioD ;  in  die  dog  ItttloornofocrotioD  is  produced, 
UMMrh,  aa  we  shall  »ee  later  on,  certain  chanKca  are  brought  about  in  the 
riaao  itaelf.  In  both  animala  the  oe re bru  spina  1  fibres  are  vaao-dilator,  and 
tM  ajmpalheiic  6bm  raso-miutrictor  in  action.  Stimulation  of  the  central 
end  of  tbe  frloBM-pharrnmnl  produoee  by  rellex  Mlioo  a  seotetiau  ftnm  the 
IMratid  ghiod.  but  tliat  of  the  linjfual  iit  said  to  be  without  eBect. 

{  CM.  The  tfcrHton  of  goflrie  Juice.  Though  a  certain  aniDunt  of  gastric 
jtuc*  may  •om«iiraes  b«  found  in  the  utotnachs  of  faaiing  animals,  it  may  be 
■Caied  genenlly  that  the  stODiach.  like  tbc  Milivary  );Unds,  remains  inactive. 
rieldtng  nn  wcr«iion,  so  1m^  aa  it  is  not  stimulated  by  food  or  otherwise. 
Tbe  advene  of  food  into  the  stomach,  however,  at  oi)c«  causes  a  copious  flow 
of  gaslriojuke;  and  ibr  i|uaiiliiy  itecreied  in  the  twenty-four  \unm  is  probii* 
hiy  very  eon^dinrabh-,  but  we  have  no  tnistwurthy  data  for  calculating  the 
vxact  amount,  So  alto  wli«n  the  gaalric  mucouii  membrane  in  stimulutvd 
nccbanicallv.  a«  with  a  feather,  M-crt'tion  i*  excitci]:  bnt  to  a  very  small 
amouiiteTni  when  the  whole  interior  tturliicc-nf  the  nlooimli  ia  tbu*  regicatcdly 
Slinillaled.  Tbe  moat  cfBcivot  alimuluK  ii>  tbu  natural  stimnluM.  vit.,  food; 
iboagh  dilute  alkaliv  seem  to  have  unuiunlly  nuwerful  ■limulatiiig  cIRvta; 
thus  tbe  nwalloving  of  xaliva  at  oti<«  pravoIcM  a  flow  of  gaMric  juicr. 

During  fnRliiig  the  gastric  membrane  u  of  a  pale  gray  color,  Muncwliat 
dry,  covervd  willi  a  thiii  laycrof  niucui,  and  thrown  into  fold*;  during  digea- 
tinD  it  becomn  red.  HiU'hrfi,  and  tumid,  the  fnliU  dimppeiir,  and  minute  drops 
qf  fluid  ai'pearing  at  the  mouths  ol'  tin-  ulnndx.  s|HHiliiy  run  together  into 
S0iall  ■irrains.  SVh^'n  the  seciction  if  viry  iictiw,  the  bltHxl  flows  fWim  the 
cn|dllariea  into  the  veins  in  a  rapid  stroiim  without  lotting  il*  bright  arterial 
hoe^  Tbe  secretion  of  gastric  juion  is,  in  fact,  acoimiwnird  by  vascular 
dilaMon  in  the  Nicne  way  ns  is  the  spcn^ioti  of  Niliva. 

(SSL  r^ing  tlmt,  unlike  tlie  case  of  the  salivary  secret  ion,  iood  is  brought 


888      Tim  Tissriis  anu  mkciiakisms  or  oioestion. 


into  tbo  innuvHiatc  nfigh))i>rli<vxl  uf  (h«  crcrctiti);  cells,  it  ts  eiraedlnely 
nrobablo  ihul  n  grunl  ilrni  i>l'  ilio  s«creiton  is  tW  nwull  of  tl»e  working  uf  a 
local  mtx'hatiiBm  -,  iin<J  this  viow  is m|>|Kirte(t  bv  tliefnct  tlinl  vrbeii  a  OKclisni- 
di]  etiniulu!^  K  ttpplidil  lo  one  8[>ot  of  ilie  },'iiB[ric  tnciubniiit!  llie  wcrelioa  is 
limited  to  the  n«i),'bborliood  of  ihal  f>pot  aud  is  uot  excited  iu  dUtiiui  parts. 
This  Will  lueubaiiifiiii  lunv  be  nervous  iu  nature  or  the  eflect  of  ibe  stimulus 
may  |)erlia|w  be  <<i>nveyed  directly  from  cell  to  cell.  tVoiu  tlie  luouth  of  the 

f;liui«l  Ml  its  extreme  base,  without  the  iutervciitiou  of  any  nervous  elements: 
lUt  the  vascular  cbau||;ei  at  least  would  seem  to  Imply  the  pruaetioe  uf  n 
ncrroua  meehanidm. 

Tilt'  sliiiimch  ia  suirplieil  with  ueri'e-fihrcs  from  tJie  two  vngi  iivrviv  luid 
from  the  ^olar  plcxua  of  the  iplnncbiiif!  system.  The  two  vug*  nl^<-r  lormiug 
tbe  ivsaphngi^iA  iilcxiiv  ou  ihe  cusophagus  are  gnthi-rcd  together  n^in  a*  tiro 
main  tniiik*  which  run  uhing  the  orvophagns,  the  left  in  thr  fmui  the  right 
at  the  back,  to  the  stomanb.  The  left  or  autcrlor  nerve  i»  <IUtribute<)  In  ibe 
sruailer  curvntiirir  anil  tht^  I'n^nt  nuriiice  of  tlie  stomacb,  fonning  a  plexus  to 
whik-b  nerve-cell*  are  pniu'iil ;  luiil  branchof  pass  on  to  the  liter  and  proba- 
bly to  the  diiodeuiini.  Thi-  right,  or  potterior  nerve  is  dbtribuled  to  the 
binder  surface  of  the  stomach,  but  only  tu  the  rxtcnt  of  about  one-third  of 
its  fibres;  about  two-thirds  of  the  librcs  pam  on  to  the  ralar  plexus.  The 
fibres  of  the  vngm  nerves  thus  distributed  lo  the  stomach  ar«  for  the  most 
|iart  noD-medullatcd  fibres;  hy  the  time  ihc  vngus  reacheij  the  abdomeo  it 
consists  nimiiftt  exclusively  of  nun -medu Hated  libres,  medullaled  tibre*  being 
verv  few  :  the  targe  number  of  niedullnteil  tibres  which  the  nerve  contains 
in  t'be  upper  part  of  the  nock  pow  oH'  into  the  laryngeal,  cardiac,  and  other 
brnnclios. 

Friim  tlie  solar  plexus  nerves,  arranged  largely  iu  plexuaea,  pass  in  company 
with  thu  dividions  of  the  cteliac  artery,  coronary  artery  of  the  stotniwh  and 
brnnclM>  of  tht^  hrjwiic  artery,  to  the  .itomurh.  Though  the  two  obdoroioiil 
splanchnic  nerves  which  juin  the  !>oltir  plexus  '.itimiluamr  giuiglia)  arc  chiefly 
composrd  of  meduUiitcd  tibn^i,  the  nerves  which  jiujw  from  the  plexus  lo  th« 
stomach  arc  to  a  Urge  rxtent  ci>mpowd  of  iion-mcdultiitc<I  lihrcs.  iVll  these 
nerv<«,both  bra^ch<.^)>  of  the  vagi  and  those  from  the  solar  plexus,  lie  at  first 
in  compnnv  with  the  artcri<.«  on  the  )>urliiec  of  the  stomach  beneath  ibe  peri- 
loueuni.  l^rom  tlicncc  they  jiitss  inward,  still  in  company  with  arteries,  and 
form  on  the  one  hand  a  plexus,  contnining  nerve-cells  between  the  longitu- 
<liual  and  circular  muscular  coats  corre»])onding  to  what  in  the  intestine  we 
iihall  have  to  speaik  of  ns  the  plexus  of  Atierhach,  whence  fibres  are  distrib- 
uted to  the  two  miiseular  coats,  and  on  the  other  hand  a  plexus  in  (he  sub- 
mui'uus  coal,  also  containing  iter ve'<?c lis,  corresponding  to  what  is  known  in 
ihe  intestine  as  .Meiesner's  plesns.  From  this  latter  plexus  6brea  pass  to  the 
mncou.i  ineailtraue:  some  of  these  end  in  tlie  niUBeularis  niucoste;  whether 
uny  are  connected  with  the  gastric  ;:laud%  aud  if  k>  how,  is  uot  at  present 
known, 

Th«re  are  no  facts  which  alford  satisfactory  evideuoe  that  any  jiart  of  this 
armngenwtnt  of  nerve*  supplies  such  a  local  nervous  mccliniiimu  iv  waa  itug- 
gtytcif  above.  The  importaucn.  however,  of  such  a  local  nu'chauiitm  what- 
ever it*  iinture,  and  the  aiilHirdinnte  value  of  any  connection  betwwn  tha 
gastric  mi'mhrane  and  the  centnti  itcrvoui)  srstt'.m,  \n  further  *howu  liy  tha 
fad  tbut  a  secretion  of  r|niii'  nonual  gartric  juice  will  gn  on  after  both  vagi, 
or  the  nerves  fmm  the  solar  jdcxns  going  to  iho  siomticb  have  l>een  ilividcd, 
and,  indci^l.  whsn  all  the  nervous  couiK'Ctions  of  the  stomach  nrv  n*  fiir  a* 
possible  Slavered.  And  all  attempts  to  provoke  or  modify  gastric  secretion 
liy  the  stimulation  of  the  nerves  going  to  the  stomacli  have  hitherto  fnilwj; 
On  tlvp  other  hand,  iu  cases  of  gastric  fistula,  irherv  by  complete  occIunoii 


CllANGBS    IX    TOE    flLANHS. 


S80 


I 


*^tR  a»u(>lift^ii«  fli  rim  latino  by  lliv  dract-nt  of  Rilivn  b^*  )>**n  avoidisl,  ibe 
uM-ra  N^ht  'ii  miit'll  of  f<HHl  linn  beoii  Mh-ii  (u  [>ruv»ki;  a  lival^  oucrolion  of 
gMtrk  juiott.  Till-  mutt  linvi-  W-ii  iluv  tu  Mniu  nervoiu  actMHi :  ami  ihu 
iKOM  iMftT  bv  HiiJ  ol'  tlH-  vnK)  wWrr  inintioaa  uf  gripf  or  niig«r  •inldi-iiW 
ailwt  iIm-  McrvtioD  going  on  or  prevent  tin-  tfcr\-li:>ii  irliioli  wniili]  utIiorwiMi 
bare  lakni  {>lac«  m  tli«  mull  of  iho  )inM-tiov  or  lliuil  in  ihc  sl'iinach.  8j 
tKftt  miicb  bus  yH  tit  be  lenniad  in  ihu  mnltar. 

i  932.  Tbr  c'tDtrast  (jreMnteH  between  iha  taiiUy  Hcration  resulting  fntia 
Birt-hanical  stinuilalion  and  tlu>  cii[H4UB  flow  which  oi'tiial  I'ucm)  iiii)u(M«  U 
interatinK  becaiue  il  sceinB  to  shoir  tbul  thcr  •ecrelory  Molivitr  of  tlie  cells  is 
bcMiiaiM  br  tbe  Bbaarption  of  ccrtiiiii  prodiicU  ileriveil  t'rotn  thi?  |)i>rlKms 
of  fbnd  fim  dif^otM).  TliiH  h  well  illiutrac«d  br  tbe  fiillowing  expcrimtnt 
of  HetdMiloiu.  Tl)»  oWrver,  niiogititi^  the  method  employed  for  the  iiit(»- 
iiw!,  of  «hicb  w«  thall  apenk  later  i>ii,  sucoeode*)  iu  iwluiia^  a  purlioii  of  the 
ftmdus  {rata  lb«  rat  of  tli«  tiioiiiiicti :  tbst  in  to  say.  lie  cut  out  a  porliau  of 
tb«  fiindiu,  Mwe<I  tnj^tber  lh)>  cut  M'^  of  the  luiio  iitom:ich,  »j  ait  to  forni 
■  anuller  but  otlkemae  coinj>lete  'ir^'un.  whik-  by  liiitured  he  conrerte^l  tbe 
'I  piece  af  fiiiidui  iuiA  a  »iuall  iiidujienilvot  sluinBch  opeuiri^  no  to  (lie 
.  I  >r  by  a  fii^iiloun  orifioe.  Whfii  fiiml  wai>  iutr<»luc«it  into  the  itiniu 
*i-mt*fh  Momion  alsci  took  [iIsik  in  the  ixi>Ut6i]  luailuH.  This  iit  fl»t  HJKht 
nUgbl  Mvm  tbo  mult  of  a  nrrvuio  n-th-x  ima  -.  hut  it  kah  olueri'ed  Iha:  the 
MCMkdarr  wcrvtion  in  the  Inuilii*  niu  dt-|)cri>)<Mil  on  netuiil  ilij^lioti  takioe 
p)M9e  in  tbo  nuin  nloniiioh.  If  tbir  mntvriiil  iiilrodiiCL-il  inlii  iht;  main  aiomich 
wart  istUgoMiblu  or  <li^<«ltil  nith  ditlicitlty,  »'>  thiit  Hltll^  or  im  [iroducts  •>{ 
dlntMioo  von  ((>rmrd  lunl  alMxrlii-il  into  the  blond,  ouch  c^.  71-.  ms  |iie['«a 
•tf  ligamcnlnm  Dticbee,  very-  lililp^ivrelion  look  \t\iux  in  thv  iMiintttil  fitnditit. 
Wo  ijuot«  tbit  noK  ns  bearing  on  the  iiiiMtioii  of  u  [xjMible  iivrvou*  iiKictiaii- 
hm  u(  gaaitic  wcMioti,  but  irc  shall  huvc  !■>  rvtuni  to  it  uudcr  aiivlher 

Th*  CUtanyrt  in  a  fliand  OanMiltHinj  Uic  AvI  o/Sterttmt, 

ft  S33.  n'c  Iwve  lion'  to  coaiider  what  are  the  chim;;ed  iu  tbe  glandular 
oeOs  tuid  tlirir  KiirnHimlinj^^  whiih  c^\ne  thi.i  t)<>w  of  fluid  |iu^MHilliE  sfiecific 
dnnutvn  iato  the  liimvn  uf  un  alreolus,  anil  au  into  a  <lucl.  It  will  be  OOD' 
VUMOl  In  iMEgin  with  the  pancruiLs. 

T1m>  thin  axteodoi)  juuicms  uf  it  rabbit  may.  hy  menu*  uf  special  prei-au- 
liom,  be  (prcwl  out  uu  tbe  Ha;^  of  a  mii;ro*(.v>p<!  luid  examined  with  eruti 
bt);b  iioni-r*.  while  ibi;  aiiimal  it  ii»l  unlv  alive  hut  under  iwch  cmditi'ins 
thai  till-  gUnd  n-mains  in  a  nuirly  nonnHl  lUali:,  L'a|mble  of  Morelinh!  vttjor- 
outly.  It  is  |HMuhlf  umkr  llxae  dnniRulAiK-i^  to  observe  eren  minut^'ly  tlie 
HpearuiDM  prr«onto>)  by  thi!  yland  when  at  iwt  and  loaded,  awl  !■>  wiil«h 
toe  changes  wliiuli  take  plai>-  during  twcretion. 

Wb«i  tbe  animal  h«  nut  l>oen  digesting  for  (nmc  IJttlo  lime,  and  the  ^laod 
ii  ihereruro  "luadol."  ihe  oullincs  uf  the  individual  ocll*,  a*  we  hav^  alrvady 
■aid.  i  TM,  are  very  indiftinei,  the  lumen  of  the  alveola*  it  invisible  or  vi-ry 
ineitiitpicuuu*.  and  each  coll  ig  crowded  with  »mall,  refnietive  spherieal  gran- 
ulca,  fonniu;;  an  irregular  granular  man*  which  hides  the  nucleus  anil  leaves 
only  a  vt^rr  narrow  clear  outer  £i>ne  next  to  the  biuemenl  membnuw,  or  it 
mav  lie  hanlly  anv  sueh  xone  at  all.     Fij;,  lOS  A. 

Tbe  Uoafl-aupply.  moreover,  it  §eantr,  the  small  arteries  being  omstriclod 
and  the  capilUries  imperfectly  tilled  with  curpusdes- 

If.  Itowevef,  llie  same  pancreas  he  exaruioed  while  it  is  in  a  sute  of  aciirity, 
^tber  from  ibe  preKnce  of  fijod  in  tbe  stoniadi,  or  from  tlie  injeetion  of  some 
MiiBntaittig  drug,  such  as  piloearpiae,  a  very  difleiwu  ttale  of  ifa'mgs  is  seua. 


840 


Tlie    riPSt'KS    AND    MKCHAMSMS    UK    DIQCSTION. 


Tho  indlvidiml  ct\\»  (Fig.  106  Jt)  Imvo  Wcomp  sniHllpr  iintl  much  nmre  dis- 
tinct in  outline  ttml  the  contour  ul'  the  nlvcoliia  which  [ircviou^ly  wiu  evcu 
is  now  wnvv.  the  hioMmfnt  m«mbrniie  being  imlcutcd  nt  the  junction  of  Um 
eel  Ik  ;  nlso  (lie  lumen  of  lh«  nlvcolus  i;  now  wider  and  more  omspicuOQl. 
Tn  cnch  c«)l  iho  grnniilee  bnvp  hecoiiie  much  fewer  in  number  and.  as  ii  were, 
have  retreated  to  the  inner  nitir(;in,  eo  that  llie  inner  granuliir  zone  is  muclt  ^ 
nanviner  and  the  outer  transparent  zone  much  broader  than  before;  thi 
latter,  too,  i^  IVcquently  marked  at  it«  inner  part  by  delicate  striie  runDing* 
into  the  inner  xone.  At  the  same  time  the  hliiodveaBels  are  lar>t«ly  diUted 
and  the  stream  of  blood  through  the  capillaries  h  full  nnd  rapid. 


no  lot. 


A  rttiTiotf  or  TKI  fxici-KKw  Or  Tits  Kjuiiit,   iKiuxn  *utl  siumiiAi  i.iu.i 

i(»lre«.  OlnxUlvnrnrllvlir.  a  Ilio  iDncrKruimJungniiv.  «htvli  In  A  it  laivvr,  khiI  noK i 
ftudil«d  Willi  tiUii  Jrnnuli'f  iltiiii  In  Jl.  Ii>  Hlilrli  Ihr  kishiiIitf  b»  I^Har  nJiit  coaratr,  ftllM  tmU 
tfaiii|*i«nl  Jtonp.  uuiiU  Id  A,  laricr  Id  A.  ■mltn  [be  laiicf  iii*rlK>l  irlili  Max  ttrtit.  rlli«  1«ni*ti. 
TSnr  otirloiu  In  0,  bal  iii'lMlniUn^,  it  an  lUdnilHilun  at  iiii<  juiictton  or  iwooetli.wdiin  B.  hm 
not  ooourrtOE  In  A. 

With  care  the  change  from  the  one  state  of  thinip  to  Ibe  ather  may  bo 
watched  under  the  microBcope.  The  vascular  changi's  can,  iif  couwc,  be 
easily  n|>prrcintcd,  but  the  granules  may  aUo  he  seen  to  diminish  in  numhcr.. 
Those  at  the  inner  marj^in  seem  lo  be  diHtlmrfccd  into  the  lumen,  and  lbof«^ 
Dearer  thf  uulcr  niiirffin  to  travel  iuward  ihr'>UKh  the  ccllnultetancc  lowarrl 
the  liinicii.  ihr  Itiint  Nlriie  epoken  ol  alxiv^,  upjinrentlr,  at  nil  rvvnli.  Iicing 
the  niarliN  of  their  jitithii.  ObviuUHiy.  durinjc  Aecrelittn,  the  granules  with 
which  ihc  cc!l»uh«l"iii*e  was  "  loaded"  are  "  disohHri^inl "  frt>m  the  cell  into 
the  lumen  nl'ihc  alveolui^  What  chatigeii  thott  (^runnlcn  mity  undergo  dur- 
ing the  discharge  ue  xhull  consider  nivseutly. 

Section)!  iil'ihi:  prepared  and  hardened  nancn-ax  nf  any  animal  tell  nMfly 
(he  same  tale  n»  ihat  thim  liild  by  tht  living  puncri'Md  of  the  nibliit.  In 
sediiins  for  inrtancc,  of  the  piincreaii  of  a  dog  which  has  not  been  («l,  and 
therefore  h»*  nut  hrru  digesiing,  for  wimc  hours  i  twenty-four  or  thirty),  the 
cells  are  seen  lo  hr  crowileil  with  granutce  (which.  Iiowovcr.  «re  tiaually 
abninken  and  irrv-gular  owiii);  t»  the  inHuence  of  the  hnrdening  agent), 
leaving  »  very  narrow  outer  wine.  In  similar  MCtiontt  of  the  pancreas  of  a 
do)t  which  has  been  rcccnlly  fed,  six  hours  helore  far  e\nmple,  and  in  irhich, 
therefore,  the  gland  ha*  been  for  wnie  time  actively  secTeiiDg,  the  granules 
are  far  less  nuinemue,  nnd  ihe  clenr  outer  inne  iiCLordingly  much  broader 
■nd  more  const'iiuous.  With  o>niic  acid  these  granules  stain  uell,  and  are>^ 
prrMTVed  in  their  splirricnl  fnnn.so  that  the  cell  thus  stained  maintains 
maeb  of  the  appcsmnoc  "f  a  living  cell.  Hut  with  carmine,  htnoatoxaline. 
He,  Che  grauulf*  do  not  Main  ntnrly  so  readily  as  does  the  cell-BubeUltce  of 
t)i«  C«I1b,  h>  ibat  a  discharged  coll  Rtaint  more  deeply  than  does  a  loaded  Mil 


CIIAN'OBS    IN    THE    GLA.VDS. 


84L 


I 
I 


bnqmie  the  Maininji;  of  (lit-  "  )iroui{ilii«niM.' "  ocllxLihMUiuee  is  uoc  »  much 
obMBrcd  by  iW  uiiMuiiitrJ  uniniiln;  baules  wbii-li,  Iiowovit, the  ac-tual  cell- 
•nbttftOff  »tittti»  I'Ttitimblr  mxui  wliiil  more  <lrq>lv  in  tliu  dUcbargeii  cell.  It 
m»y  iit  mIUmI  tliiit  iii  ihi-  iju('hnrg<:il  (vll  thv  niioli^i^  !«  coii»picuoiu  aDd  w«)l 
fanned :  in  ib«  IoiwIhI  ocII  it  io  ^ix^mllv  in  prrpurci)  MCtioDit,  more  or  Iras 
imftitar,  poMiblr  bonuMr  iu  tbcw  ii  i*  (<!»  dvnw  Bti'l  more  watery  than  in 
Ik*  diMharg«d  evil,  and  an  ahrinks  under  the  iiiHucnoc  of  th«  reoieetiU 

Tbrae  M>ver«l  i>WrvBtiom  «ugg«t  tbi.-  cuiicbiMon  thui  in  a  gland  ut  raet  the 
ocll  u  ncctiptoal  in  ftirminif  bj  mnttw  of  ihc  niclaboliaiD  of  itn  cnll-itubiuiiiice 
SD(I  Imlging  in  itn-lf  ($  '.iOt  oertaiii  gruniilw  of  peculiar  suhttance  iuUnded 
to  hv  a  pan  ami  |in>b>iblj  an  importanl  pari  of  the  wKretion.  Tliia  gnca  on 
until  ili«  n'll  i«  RKin<  or  leM  completely  "  load»l."  In  sucb  a  evil  iho  amuunt 
of  actual  liviuK  i<ell-#u  beta  nee  ib  n^lalively  auiall,  its  placo  is  largdv  uccu- 
PmO  by  granuTa,  and  in  itwif  bns  boeii  [lartly  constiniod  in  fornifiij;  lh« 
gnUHM.  During  tbc  net  of  Mcrction  ibe  ^lanules  are  dL8cbcirgi-d  to  form 
|Mrt  of  tbe  ttcretion,  other  iuatu>ra  iiicludii^  waier,  a«i  ue  ithsll  *•%,  ninkiiig 
Dp  Uw  whole  MCKtion:  and  tho  cell  would  be  prnportiunalelv  rcducixl  iu 
w«  werv  it  DM  that  tbe  act  of  tbe  discharge  teetaa  to  itiiuulato  ibc  <-cll- 
nbrtvicv  to  a  new  activity  of  ^mwib.  «o  that  rhc  new  cell-«u balance  it 
fiivaad;  tliia,  faowerer,  'a  in  lura  aouu  in  part  cunaitiuied  to  order  to  form 
Dew  ytaiiulea.    And  wbal  is  thus  aeeji  wiib  conxidcrable  diitjuotnew  and 

bCBM  IB  tbe  pancr«a«.  b  »een  witb  more  or  lcn>  di«iinctn««<  in  olber  glaixU. 
(234.  W'bvii  ue  study  au  iilbiiminoun  elund,  tbe  parotid  gland,  for  in- 
atmotx.  in  ■  living  .-uiv,  no  lin<l  tbiil  tbe  (Pangea  wbiclk  take  plaoe  duriDg 
•rtiviiy  are  ijuite  comnorablc  to  ihow  of  Ihc  pancmut.     T>urit)j;  rest  (Pig- 

1107.  A),  tbi"  cellg  are  large,  tbeir  DUtlint^  very  indistinct,  in  fact  almost  in- 
rbiblr,  and  tfae  roll-Rib«tancc  a  studded  witli  granules.     During  activity 
'  Fig.  107,  U » tbe  cells  became  amnller,  their  outlinea  more  dIsUnol,  nud  the 
ilk 
Tlwanp^sIMb  I*  tanmitat  dlaaBmoiaur.  npnMaW  iba  niicroHOpIc  (kuicis  wblchuuf  Im 
BtavndlDlkalMVfllBd.    A.  piBlltf  ml     Tlw  etwvnr  outllna  oT  tile  calli  arc  lnlr»lv»l  lo 
UvMiUI**  dHof  lb*  •vCb:  Uiei- o»ild  noC  be  mdUjr  awn  In  Um  f|«daiin  ilvtf     M.  Atlsr 
•aniiilaUnn.    C  Attn  pmXiuaml  lUuuiUUuu.    Tliv  qocIbI  an  dlacmniniUo.  «ud  lutni. 
l>*lwwia«lrap|iWB»eEMid  ]a*l(lnn. 


graaulM  disappear,  eB|)eciallT  from  the  outer  portions  of  each  «cll-    After 
pr»l«ageic)  activity,  as  in  Fig.  107,  C.  ibe  celU  are  «ull  smaller,  with  their 


rt».  K/s. 


nnlltnea  Htill  more  diittint:!.  luid  the  gnuiulca  have  diaapiMarad  almrxit 
Mitiraly,  a  few  only  Iwing  lelt  rtl  tlio  exireBM  inner  margin  of  anob  cell, 
ntnittiuj;  ufiun  tbt'  conitpicuouB.  aln^Ml  gaping  lumen  itf  ibo  alrenlu*.  And 
upxn  #|>m:ui1  examination  il  is  found  that  tbe  nucli-i  arc  large  aiiil  round. 
In  fart,  ite  mi(;bt  almoH  take  tbe  parotid,  ax  tbu«  studied,  tn  be  mure  truly 
typical  of  M-rretory  ebaDgea  rhan  eves  the  paiicmui.  For  the  demarcatioD 
of  an  inner  and  ouli-r  lane  i»  not  a  necenarr  feature  of  a  secreting  cell  at 
mi.     What  11  eweutial  is  tbai  the  oell-suwtance  manufaclum  ruaierial. 


S42 


THE   TlSSfKB    AM>    MECHANISES   OF    T>ieESTK*N. 


wliicli  r»r  n  n  hilr,  ihtic  in  diirhiE  rT»i,  i»  depnfiiril  iii  ihc  veil,  genornlly  in 
Iht!  form  nl' griiniilca  hut  not  iii'C'<^'»»rily  «»,  iin<l  timt  diirinc  iirtivily  ihtt 
tnnlrrial  iti  iiM'il  up,  llie  ili«n])|M'iiruii(f  ■>>'  (h<*  ^rnniiii^,  wltcii  thmt  nre 
vitiilik*,  Iipiiif;  nainrullv  fiirlit-^i  na<\  niiml  niiirki'i)  nt  ihr  tmu-r  lairtioiis  of 
each  cf'll,  and  progrcwJiig  hiwnril  Kiwiird  tliu  lumcii,  ihe  nliole  cell  becoming 
itnallvr  iiiiii  uc  il  wen-  ahninkrn. 

lo  iIk'  cell*  of  tlic  pnrotiil  ^luml  nnd  otlicr  iilliumirimie  cells  the  gninti'r* 
Bccn  ill  (lie  living  or  Inth  cell  ditlcr  from  ihi-  gninul^  Been  in  iho  pkncrmltc 
cell,  itin[>niitch  tm  they  lira  tiiMly  dJKolvpd  tir  broken  up  by  the  action  of 
nicohol.  chromic  Rcid,  mid  the  olher  iiFunl  linrdenin;;  reajjenU,  ond  lieacc  in 
hardened  specimens  hare  di»appenrpii.  In  coneefjuence,  iu  aectioOB  of  h.ir- 
dencd  and  prepared  albiiminoua  glands  the  difli-rence  between  reetint.'  ''T 
loaded  niid  active  or  ditcbtirged  cells  may  apjiear  not  verv  coii^icuuiis; 
and  ihis  is  especially  the  ca^  iii  the  jmroiid  ^latid  of  lh«  rnbbil  when  rhe 
activity  lias  been  calleil  ioin  play  by  ^.tiniiilalion  nf  thu  iiuriculo-l«m[mnil 
ii«ve.     When,  however,  either  in  ihe  rabbit  or  the  dog  iho  cerrical  sym- 

Intthetic  i»  atiuiulHlcd.  tboucb  the  Htimulntioii  girCM  ri»e  in  llic  rabbii  to 
itlle  »(crelion  of  -laliva,  and  in  tht:  doj;  to  muKt  nt  all,  n  marki-d  vllr<-t  on 
the  gUnd  ia  prodiicvd.  and  chan;{««  in  ilic  auiuc  direction  iv  ibfHc  alnuidy 
dtfCrilH'd  niny  he  obsiTvcd.  During  rwl  thv  cells  of  the  piifolid  ai"  rtrn  in 
tectionn  of  the  jjtnnd  hardened  in  alcohnl  ( I-'ig.  lOM,  .1 1  jirr-  |>nt<*.  lranM|ia- 
ri'nt,  sininijig  with  ditrn.-ultv.  ami  iIk^  nuclei  piKcc"  irregului'  outUiH-*  a*  if 
»hriink«'i]  by  tht^  rengi'iitii  employed.  AIUt  Hiinudation  <<l'  th«  sympalhetic 
the  pnilop)a«m  of  the  crllx  hccomn  turbid  (Fig.  IU8.  B},  ■»<)  stains  much 

Fm.  101. 


^n-iii>.v  or  TiiK  i'tnuttii  »r  ih^  KaUkT.    iJinti  lluiicMUiit.i 
.1.  AirtfL    S.  AHut  itlBnUUui  or  llie  rarvl(iil«pnp*.|li«]i:.    Unlti  tccUUu  afe  IRiia  MnlnnT 

■tend. 

more  rendily.  while  the  nuclei  are  no  luuj.'sr  irreKnInr  in  outline,  but  round 
and  large,  irith  conspicuous  nucletdi.  the  whole  cell  at  the  muuc  liim^  at 
le**l  afl«r  prolonged  Hiiuulatioti.  becvimtng  di«tinctly  smaller. 

^  235.  Ill  &  mtirouit  gland  the  changed  which  take  place  are  of  it  liko 
kind,  though  Bp|>ar(!ntly  »onieu'hat  more  cnmplicJilcd.  ntvin;;  prulmhlr  to 
llio  peculiar  dianiden  of  the  mucin  whtdi  i« (o  cunapicuous  a  (.■uiwlitupnt 
of  the  MiTclioii. 

Tf  n  piece  of  rf»ting.  Icmdcd  tiihmasillary  glaml  bo  teased  out  while  frwh 
Mul  warm  from  the  IkhIv  in  norninl  sniiiie  nobition.  the  cell  'ubelance  of  tiie 
mu(xiu»  eclle  <  Fig.  109,  a)  i»  seen  to  tie  crowded  with  grnnulos  or  ephcnilev, 
which  may  fairly  be  compiired  with  the  granules  of  the  pancreas,  though 
perhaps  leM  dense  and  solid  than  these. 

If  ■  piece  of  a  gland  which  hae  been  secretiDg  for  eonK  time,  auil  h 

therefore  a  dischargerl  gland,  be  examined  in  the  same  way  (Fig.  100,  h), 

the  granules  are  far  less  numcr^ius  and  largely  I'ontineil  tu  llie  ]Mrt  of  tli« 

ell  nearer  the  lumen,  the  outer  part  of  the  cell  aniimd  ibeuucleufi  i-(iti!<t-iinfl  ' 

rpr  onlinary   "protoplasmic"    cell-subsUince.     'flie    dtMinction.    howcvt 


CIIANii£S    IN    TUB    GLANDS. 


U9 


no.  lat 


bvtwnii  Ml  iuiMT  "gntiiiUr  zone"  ntrxl  to  the  Uinwo  ttid  in  niitcr  "dnr 
flooa"  nrsi  III  thi-  hMrini'Dl  mvmhmnt?  tc  li-w  iliMiiict  tliiin  in  iW  pimcrcmM, 
|«rU7  bwniur  itiv  granntn  ilo  not  diNin- 
jmmr  in  t»  rq^lar  a  nmnnpr  ns  in  llio 
t»anmii.  umI  |<«ily  bc<-»i)w  lh«  oiitrr 
of   tli«  Diuruus  cell,   ne  it   fornM, 

BM  boiDOffeDMHifl  ihnn  that  of  th«  pan- 

■tie  cell. 

Th«  "i^ranuln"  or  "Bph^roleg"  of  iho 
nmeoui  e«]l  are  tunn^tver  of  u  peculiar 
natun^  If  tl>«  fmli  c«ll,  mhuiviug  (;nui- 
alc»  (eiihtrr  man}'  aa  io  iho  ca»e  of  a 
loaded  ft  few  aa  io  the  case  of  a  dia- 
char^ml  ccllk,  Iw  irrigaiett  with  water  ur 
with  iliUiif  acliU  or  dilute  alkalies,  Uie 
gratiiilr*  *«a'1I  up  ( Fi){.  109,  a',  b'}  into 
s  traii*)iBiri>l  niaK>,  giving  the  react iou^  of 
marin.  lniv^r»r<l  l<y  n  network  iir"pm- 
Ui|>la>niit- "  cpllfulmUnce.  lu  lhi>  miy 
i*  producvil  aii  apfK-umnro  von-  limitur  to 
ibM  aliowii  in  sfCtionii  of  niuroii*  v''i'n<U 
hardcfxd  and  lUiinctl   in  the  ordinnrr 


*L 


_l««e  havo  alrmdv  snid  (£  210),  in 
ibe  loaded  tnucmic  ^'cll  in  such  biink'iH'd 
ajdd  Mainvd  pnpanUioiu  (Fig.  11  n.  a) 
ihon  1*  IMA  «  nnall  qiiuntitv  of  proto- 
plasmic i.-tI1  wlttinncegntlRTed  round  the 
ngcleu*  at  tbo  milcr  part  of  the  coll  next 
U>  (!>«■  bawtiMint  nK-nibraiie:  the  mt  of 

Um  nil  rante^i  of  a  uelwurk  of  i-ell-Bulwtance,  iho  inlervlicm  Itciiig  lillvd 
whb  tnuMpnn-nl  material,  which,  unlike  Ibe  network  iioolf  and  Ibi-  ninw  I'f 


UBV    QbUlU  oi    Iw.      lLj--«>LtT.) 

■  Hiiil  b  bmbitfil  111  t  ivmnt.  Mil  tUn- 
tiuii:  a.  fRmi  |m|ed  (Isiid:  b,  ftwii  dbk 
rlinfiTTd  kI«jii1  ilbc  sucM  lira  ii'wll)'  mum 
MbM'iircil  by  (mnulpt  Uuii  !•  btir  npre- 
•mlM>  on  ln»Ic«  mil  •  mtli  (V*Kintal 
ill  I  tu  1  im  miL  Mil  K-1uUi«.  lUn  nils 
luiully  brcnino  linAm  ui'tulliii  Im^IhwiI 
rall>  ft»  rkfvlf  obiainal  tultv:  kHitiM 
cell*  ■!«  (muiicin  iruwiliml  Iw  Ml  lu  llic 
tnl)-  Inr  •  Oijr  allK  dMtb.  ■'.  V.  trnlRl 
■ilh  ditiiw  ariil:  ■',  ftonkaiiloa:  V.tnM 
lUwIiiupd  rUnid. 


Ainou  <w  I'M'*  A'MittiiuBV  CiuAii  lUu>mr  ik  Aurnitoi.  ako  fttinai  wnu  CiHm. 

lUuiawnt-i 

n«aM«««tto>llw>unmiW.    a,Avia«lmleiltluid.   Ufra)na>llMh«>v»4sUiMl:  tlMtbanli 

(jnitBDl  lw*lna  ••««  atUDUUMil  at  (bprt  UiUml*  ilartiis  live  InHIix 

niK-lett*,  d<iea  not  r^iain  with  oannine  or  with  corlain 
r^d  nil  in  wmilnr  preparations  (Fig.  110,  hf  difKira 


844        TUB    TISSUES    AN'1>    MKCHANISUS   OF    D10E3TJ0.V. 

from  the  Insded  cell  in  the  atlll>un^  of  lrHnH|Hireiit  non-stainiiif;  material 
bung  much  leee  and  cliieBy  caallaed  ii>  chi>  inner  part  nf  the  cell,  while  the 
pntopluMnio  i.<en-iiul)HtaiR'e  around  ihe  now  larve  nod  well-formed  nucleus  is 
DOtonlj^,  both  relaiively  and  uhaolutely,  ^r^itter  iu  iiiuoiitit.  liut  stains  still 
more  dwidy  tbiiu  in  the  li^aded  ivli. 

It  wuuld  nf>|X!Kr,  therefore,  that  in  the  luucoiia  cell,  an  in  the  pMicreaiic 
cdl,  the  <<v))-»>ibH(aiicc  forma  atid  d^-ixisitd  in  itself  certain  material  in  ihi- 
form  of  gmniilc-!'.  During  secretion  ibo^e  ii;rni)ule*  iliwippMr  anil  iin^^uni- 
nhl}*  f>>rni  part  of  the  M^i-retiun.  But  ihi-  crumilvs  of  u  murou<  wU  dilli-r 
t'rnni  thiwi'  of  llic  |iiiiicrrJitic  ci'll.  iniisjniicTi  h*  llivy  iiri-  iipt,  under  the  in- 
flticnci'  if  ri'iismlf,  t'>  hv  trnn#fc)rnii;il,  while  Htill  wiibin  ihn  cell,  into  the 
Irniit-pnrerit  vwciii  malvriid  which  we  call  mucin;  hrm.*  tlio  appearances 
prewnlcd  by  sections  of  hfirdcncl  pliint!^  It  Mcem'  natunkt  to  infer  that 
the  grunul<«  consist  not  i^f  mucin  ilsclf,  hnl  of  a  forcrnnucr  »f  mndn,  i>f 
some  siibettimT!  which  can  give  rise  to  mucin,  and  which  wc  might  call 
mucij^'eD.  And  we  might  further  infer  that  during  the  act  of  secretion  the 
;;ramiles  of  muei^ii  are  ImnsforniMl  into  mnwcs  of  mucin  and  so  discharged 
from  the  cell.  Lnd«ir  this  view  the  appearances  presented  br  the  hardened 
glands,  &»  distinguished  from  the  living  glands,  might  be  interpreted  aa  Ui' 
ilieatinK  ^''"l  under  the  iofluencr  of  the  reagents  eaiployed,  tbe  mucigeo  of 
the  li>a<led  cells  hnd  undergone  the  I  runs  forma  tion  into  mucin  tiithoui  being 
diacharged  from  the  cells.  Up  to  the  preeenl,  however,  it  has  not  been  found  - 
poauble  to  isolate  from  the  gland  any  deBnile  body  capable  of  being  oon- 
vert«d  into  mucin,  and  there  are  aume  reasons  for  thinking  that  not  only 
tbe  gninulea,  but  part  aUo  of  the  substance  between  them.  cuniTihuiai  to 
tbe  ^rmation  of  mucin.  Apart  frum  this  comjilicnttoii.  bow<^ver,  the  geii- 
cral  courae  of  events  iu  the  muci>us  cell  ^eema  to  he  the  Mime  m  in  the  pian- 
crciilic  cell ;  the  cell -substance  oiaitulacturea  and  loads  iUelf  with  u  ^jincinl 
prwlnct  (or  s[)ccinl  products):  during  the.  act  of  secretion  ihi^i  pr^xluct, 
undergoing  at  the  lime  n  ccrtniu  nniount  ifl'  clinngc,  is  discharged  from  tbe 
cell  to  form  nnri  of  the  secretion,  and  the  cclt-eubstuncc,  Mirred  up  to  in- 
creased growth,  subsdjucntly  nitmufnctnrun  a  new  supply  of  the  producL 

§  236,  The  "  ccJilral"  or  "chief"  cells  of  the  gastric  glands  also  exhibit 
Nmilar  changes.  In  such  iin  animal  ns  the  newt  these  cells  may.  thotigb 
with  difficulty,  bo  examined  in  the  living  state.  They  are  then  found  to  oe 
Mudded  with  granules  when  the  stomach  is  at  resL  During  digcfltioil  tlieae 
granules  become  much  leas  numerous  and  are  chieHy  gathered  near  the 
lumen,  leaving  in  each  cell  a  clear  outer  zone.  And  in  many  mammals  the 
Name  abundance  of  granules  in  the  loaded  cell,  the  same  paucity  of  gnuiulea 
for  the  nioHt  nart  restricted  to  an  inner  /.one  in  the  discharged  oell,  may  be 
demousLrated  by  the  uae  uf  osniic  acid  (Fig.  Illy. 

When  the  ttComach  is  hardened  by  alcohol  thttie  ehaugM,  like  the  similar 
change*  in  an  albuminous  cell,  are  obscured  by  the  nhriuking  uf  the 
"grsnuW,"  or  by  tbeir  swelling  up  and  becoming  ditl'ii^ed  through  the  rr*i 
of  the  cell-sub«taaoe;  ao  tliat,  tliough  in  aeolions  ao  pri-imn^l  vt-ry  Mrlking 
dilTcrmcci'  arc  wen  between  hmik-d  and  duchareed  cells,  ihi-sr  iirc  unlike 
th'wc  scrn  in  living  ghindn.  In  >|niciraens  taken  troin  an  nninirtl  which  baa 
not  l>cen  fed  f'lr  ngmi-  ttnn-,  the  centnil  (■i-IIm  of  the  gastric  gland*  are  imk', 
6ncly  granular,  and  do  not  stain  readily  ivilh  carmini:'  and  otli<-r  dyes. 
During  the  corly  stages  of  gastric  dig^'Ation,  the  same  cells  arc  found  some-j 
what  sirollen,  but  turbid  and  more  coarsely  granular;  iheyxtuin  much  mor 
readily.  At  a  later  stngc  tbey  become  sni.illor  and  shrunken,  but  are  ' 
more  tnrbid  and  gmniilar  than  iHrforu,  iind  stain  still  niorr  deeply.  Thb  ta 
true,  not  only  of  the  central  cvlli^  in  the  ennlinc  glands,  but  also  of  the  cella 
of  which  the  pyloric  glands  are  huilt  u[i.     In  a  loaded  cell  very  liltJe  staining 


CtlAXOBS    IN    THE    0LA.VU8. 


S45 


I 


I 


l-i.>  III 


:\ 


<B» 


take*   plaoe,  becanse  the  nmMint  of  living  sUltiiinj;  vtrll-mbetince  b  Rtiuill 

niatiwiy  to  tli«  mmiot  of  malcrial  with  whioh  it  i>  loaded  sod  which 

dooi  not  Main  rtadilv.     In  tli«  cell  whidt  iil\i.-r 

Ifnmt  Mtivity   hu  <lbobufed   ilMlf,  the  cell 

MHBdl«r.  but  «h«t  remains  ia  Imn^elr  living 

eall  MihsUum,  Bume  of  it  new,  and  afl  ^lain- 

iafl  rautUj.     li  would  ap|)ear,  also,  that  dur- 

iajt  Ibc  activity  of  the  evil  flume   «ulMlauc-€H, 

capable  of  beiiifc  precipitaleil  I>y  alciiliol.  make 

Utwr  appwraDoe.  and    itiu   pre.-i^iu-e  "f   i)ii» 

■atfwial  add*  to  the  lurbiil  and  icmnular  aspect 

of  tbe  cell;    pii»ibly.  nUu,  this  niiilunal  con* 

tribaiM  tn  ihi-  *taiiiiiig.      A  siuiilur  niulcrial 

■MM!   lo  maki-  ilK  appearand!  in  the  oelb  of 

albaminoiu  glandji. 

In  th«  OTOid  or  lxjnl«ir  c*ll»  mi  vtry  chnrao- 
tariitia dtangn  make  llK>tr npix^ranw.  Duriii)c 
di^lioQ  Uwy  b4«onw  larger,  niont  vwolU'n,  lu* 
it  mtre.  and  in  oun»«iiiwicii  bulge  uul  thu  luiw- 
mrai  iu*:iiibrantr,  hut  no  cliarncU-riotic  di>>n{>' 
prNnnrt'  of  gmnul«»  can  tie  uhi«rrol.  In  tti« 
living  ftatv,  [h«  cell-siihstancc-  iif  itiov  ovoiil 
rvlb  app«an  finelv  gniiiiiliir,  but  in  hnrdi-nvd 
awl  prepared  N.-cti^oni  hv  n  cniirMdv  ^'raniilar. 
"  rv(irulat«  "  ]i»ik.  which  is  prrhii|»  lin*  innrltvd 
ia  ibe  ivullen  active  cell»  than  in  tbc  reeling 

nib. 

I S37.  All  ibcae  vamua  aecreiin);  cella,  then 
— puKreatic  cell,  inucouii  c-ell.  albuminous  cell. 
MM  eanttal  fastrio  cell — exhibit  thenuieaeriea 
of  Mcala,  tnodifted  to  a  certain  exlent  in  the 
•wml  ouea.  lu  eacli  caitv  the  "  pro^jplaamic  " 
«*ll4uhatanoo  maHufaciurei  and  lodra  in  ilaelf 
nMafial  <teMintd  to  fonn  part  of  the  juice 
■ai  rnmit  In  iJw  tnA  veil  this  material  may 
MMralljr  be  recogsiMd  under  the  micrnjm|ie 
DJ  its  optical  obaractore  nf  gmnul«^;  tbaae, 
bomtirr,  an>  apl  to  beoono  allied  by  reamita. 
Bat  «e  must  guard  oniwlvM  against  tne  lu- 
naptioa  that  the  ninli-rinl  which  can  thus  be 
rffinpiif'  is  thoofily  matprial  thus  stored  up; 

we  mar.  in  future,  by  ehontical  or  other  means,  be  able  U*  diHVrentiaie  other 
parts  of  the  eell-b<ily  as  being  also  nuiU-rial  similarly  stor^t  up. 

During  activity,  while  the  giniiit  tiiM'cri^tinc,  tht«  mntcrinl,  either  unchanged 
or  alter  uuder^gving  change.  i«  wholly  or  partially  dlscharge<l  from  th<t  oell, 
Tbs  cell,  in  oomequenoe  of  havini'  thim  got  Hd  of  more  or  less  of  ita  load, 
(onaisU  to  a  lareer  extent  of  actual  living  eel  I -substance,  ibis  being  to  mnnv 
amm  inoreaaed  by  rapid  neW'gT<-intli,  though  iho  bulk  of  the  discharged  cefl 
mar  be  Ina  than  tliai  of  tlie  loaiied  cell. 

"hiia  adlvitT  of  erowlb  oontinuee  al^er  the  net  of  secretion,  but  the  dis- 
ehargHl  cell  soun  begins  again  the  task  of  loading  itself  with  new  seeretion 
tnatrfial  hir  the  next  act  of  secretion. 

Thus  in  most  cii^m  tb<?re  is.  corree ponding  lo  the  iniennttteoee  of  secretion, 
an  altemniwn  of  dl^-hiirge  and  loading ;  but  it  muil  be  bjrne  in  mind  that 
Mwli  an  allemaliun  ia  not  abaolutely  oeeauwry.  eren  in  the  ease  of  inler- 


liVttlK  IlLAHU  (ir  U*JIX41|1UT) 
DCKlini    ACTITITi:.     ILUIOLKT.) 

t.  tli«  motrth  uT  111*  Klftod  wtlli  ll> 
tXlliKl'lotl  sella    a.  Uio  nwk.  turn- 

UUUllUI     CaiI>>Clll>IU     llTdld    (Bill. 

wlih  tliotrcnano  p(«M|,lH>nk  iiot- 
wurk.  /,  IhlF  botjr  iir  llie  Kland. 
Till'  r™anlw  •>*  (Mti  In  tbuntn' 
tiKl  ivlb  to  br  iTinltnl  lii  ihf  liintt 
luniuiu  uf  raeh  mil.  I  he  rouiiil 
i>iw]Viu  at  It  hloh  U  co(i«plouartB- 


840       THE  TI8SCBS   ANU    UBCIIA!fl8MS   OP    DtCESTIO.V. 

tnittotii  accretion.  Wc  cnn  cn«i1y  imnginc  ch»l  lh«  tliM'linrgc.  »nv  of 
"  jiiraiuilcB  "  (lurin)>  wcnl'mn.  fihuiili)  stir  up  the  coll  to  iin  iiii'rcasml  Rctivity 
ill  romiin)^  ^'cnntile^,  ninl  ihal  tho  formnliro  activity  flioiili)  i-eosc  wlncn  tli« 
Kcrclorv  activity  I't^nrteii,  In  such  a  cftee  tho  number  of  nvw  graniilM  furnied 
might  alwayc  be  eijual  li>  the  number  of  old  grHiinlo;  uhfH  itji.and  th«  active 
cell,  ill  spite  of  its  discliarce,  koiiM  prwees  an  miiiiy  granules—that  i$  to  mv. 
IIS  laree  n  load— aa  the  cell  at  iwU  Ami  in  the  ceniral  pastric  cells  of  »ome 
niiiDiah  it  wuiild  nppear  that  sucb  a  cMiitioued  balunciuj;  nf  luad  aiid  dis- 
charge does  ai-tually  take  phtce,  to  that  no  distinction  in  Knioulee  cao  be 
ubwrved  between  rettin;;  and  active  relU. 

§  238.  We  s]x>ke  juat  dow  of  the  material  stored  up  in  the  cell  and 
destined  to  form  part  «f  the  secretion  ii«  undergoing  i^fmnge  before  it  wm 
dischni-gied.  In  the  iiitiiiius  cell  we  hove  ^leen  that  the  maleriHl  deposited  in 
tlitt  liviuf;  cell  has  at  lini<i  the  form  uf  ^raiiul«».  TliMe  granules,  bou'ever, 
are  en&ily  i-onvertcd  Into  a  trHii.-']inrent  matea'al  lotlged  In  the  sjiaeea  of  ih« 
cell-Rubstauce,  nbtch  miiioriiil,  even  if  not  exactly  iileniieal  with,  at  loojl 
elowly  rtseniblcv,  the  muriu  found  in  the  lucrt-tiou;  and  ap|>Mrentlr  in  the 
act  of  secretion  llie  ^annh-s  do  uiider^M  «ume  nucli  change.  In  Uh'  <.■■» 
of  tonic  other  {;land:<.  iiinrvovi'i',  vre  hav<'  chemical  ns  well  as  optical 
i>videii(%  that  the  inaicriid  ttored  ti|i  in  the  ci-IIm  u,  in  part  at  IcuM,  nol  the 
actual  »ub«tanc'c  apitcnring  in  the  wcretiim,  but  nn  antccck-ni  of  that  sub> 
■taiioc. 

An  imimrtant  cnn»tilueiit  of  pancreatic ^oici:  v,  iw  vrc  Hhnll  M.-e  later  un.  a 
bodv  callwi  fr^ipna,  a  Urnivnt  very  similtir  to  pcp»in,  acting  "ii  |irotviid 
bod'iM  and  convi-rling  thcni  into  [wptonc  and  other  »iih«tunci».  Though  in 
many  r«pcct»  alike.  prpMn  nml  tryniin  arc  quite  dintinrl  l)ndi».  and  liiKvr 
markedly  in  ihi>,  Ihnl  while  an  acid  medium  in  nci'iTMnry  for  the  actimi  uf 
ppeio.  au  nikalioc  nicdiurn  is  nec^iwary  for  tho  action  of  trypsin ;  an<l  accnrd' 
iii^ly  the  pancreatic  juice  is  alkaline  iu  contrast  to  the  acidity  of  i;aFtrio 
juice.  Trypsin  can.  like  pepsin  i,S  2i)5).  be  extracted  with  glyc^riu  from 
Bubeitancea  in  whieli  it  occurs;  glyoeriii  enlracf^  of  trypsin,  however,  Qee<l 
for  the  maniftfilation  of  their  |><>wer.«  the  pre-ence  uf  a  neak  alkali,  sucb  aa 
a  1  jier  rent,  anliition  of  sodium  ctirl>i<nate. 

?ton',  try[uiin  is  pr(?«nt  in  ahii udiiiuv  in  normal  pancreatic  juice ;  but  s 
loadetl  pant-reun.  onii  nhtch  ix  ripe  for  ^-crelion.  and  which  if  excitnl  ta 
wcrcle  woulil  inmiciliiili-ly  pour  out  n  juicct  rich  in  try|i»iu.  cniain*  no 
tryiKiin  or  n  mere  [nice  of  it;  nav,  even  a  pancivitt  which  in  en^itwetl  iu  tbc 
•ct  tif  w;i'r('ting  eonlnin*  in  il«  actual  itIU  an  iuKignitii-aiit  <pianiity  only  of 
iryiwin,  ii«  i*  sliinvn  l»y  the  fMllowing  cKiM-rimonl: 

If  the  piiricn-n»  of  nn  animal,  even  of  itnit  in  full  digrftion.  bo  imiied. 
whilr  itill  u«Tm/roin  thr  liody,  with  glycerin,  the  glycerin  eximcl,  n*  juilgol 
of  br  it»  action  <>»  fibrin  in  the  prcfencc  of  wxlinm  carbonate.  ii>  inert  or 
lioarly  ko  w  regards  prolcid  bodies.  If,  however,  (he  same  pniicreaif  be  kept 
for  tncitly-four  houre  before  biing  treated  with  glycerin,  the  givceriu  extract 
readily  digests  fibrin  and  other  prolcids  in  the  presence  of  au  alkali.  If  ihs 
pancreas,  while  still  warm,  be  nibbed  up  in  a  mortar  for  a  few  ininutca  with 
dilute  aceik  add.  and  then  treaietl  with  glycerin,  the  glycerin  extract  i« 
strongly  proteolytic.  If  the  Hlycerin  extract  obtained  without  acid  from  the 
¥rann  paucreos,  and  iherefore  inert,  be  diluted  largely  with  water  and  kept 
at  35"  C  for  rtorae  lime,  il  hecumes  active.  If  treated  with  acidulated  instead 
of  dmilh-d  water,  iLi  activity  io  nuieh  souiier  develii|>ed.  If  the  inert  glycerin 
extract  <>f  warm  piiucrmn  be  precipitated  with  alcohol  in  excew,  the  precipi- 
tate, inert  as  a  pnUooiyiic  Icrmeni  when  freab,  liecomei  active  irhen  ex|)ose<l 
fur  some  time  in  an  iKiueoun  folulion,  rapidly  su  w  hen  truited  with  iicidiilateil 
water.    Tbew  fads  show-  that  a  p;tncr«as  taken  fn-sh  from  the  body,  even 


I 


hI  tillle  mad^matlf  femunt,  lliitiiu:)i  l)ior«  b 
iruo  kiu'l  of  ucoumpcwillAO,  jri'i'"'  oirt/i  to  thv 
nL  Wp  RiBif  rrmark  iiiciik'tiiiitly,  ilmi  lh<>iigli  ehp  prcw-in'i'  of  mi  nlknli 
!•  wtBlMil  to  the  jiTvitrolylic  Kctuni  of  tbr  ncliial  ferment,  the  fori imt ion  of 
Ibv  ftrnient  out  of  il*  ri^rrruiiDcr  i«  favorol  tiv  ihc  prvwtnco  uf  ii  vmnll  ■(unii- 
tilT  of  acid  :  llM-aciil  muil  he  uwal  n it h  Litre,  «iiico  the  Irypein,  »iiee  fonixnl. 
M  de»ti»rril  bv  acti)!.  T»  lliis  tHiilv,  this  mother  of  the  formcnl,  which  hiu 
uA  U  pi>«ent  been  MlUfActorilir  iMlatcd,  bnt  irhieh  «i>pciini  to  be  (t  coRi|iIex 
body,  Fpliiiing  up  into  the  fernteni,  nhich,  as  ire  hitve  »ea,  is  iit  all  ovcuie 
m4  cmainlr  ■  pr<>1eid  body,  and  into  Hn  undeniably  proteid  body,  the  natne 
of  9«Mi^«n  niu  be«n  applied.  Dm  it  is  better  to  reserve  iti«  term  zym>oeeD 
m  ft  K«Derie  name  for  all  suoh  bodiw  aa,  not  being  tliemKkee  actual  fer- 
n«al«,  IB«T  by  internal  chanjfes  fpve  rise  to  fements,  for  nil  "  molhere  of 
fcrmtrnt "  in  fart :  and  to  fj've  to  the  [uirticiilar  inoilier  of  the  pancmiic 
l>ni(ei>lnic  ferment  the  name  liyp'iuoj/en. 

Cvideoce  uf  u  aimilar  kind  nhoui»  thnt  the  Kiuirio  Riaiid*.  botti  the  L-;ird!ac 
and  tbe  pyloric  jflaudi,  nhilt^  they  cotituin  ccim]mratiirely  little  actual 
p«pNn.  csMitsin  a  considenihle  (|utiu[iiy  of  n  lymogen  of  pe[nin,  or  pri-tiiw 
ym :  attd  there  can  be  little  doubt  but  that  thia  pcpnuojfeu  is  lodged  in  th« 
evnlml  ceJIti  of  the  canlinc  t;t))ndi  and  in  the  aomcwbat  timilar  cells  which 
line  the  «h<d«  uf  (lie  pyloric  ^landi^ 

It  ia  fkirtfacr  inlvrMting  to  ntiMn-e  that,  iia  a  g«neml  nih*.  the  amount  of 
tryf«ifK>^n  in  a  |iancri-aa  ni  any  givwn  tim«  rttc*  and  txwVr  pnri  pattu  with 
tbe  nmniilnr  innfr  /one, '.  r.,  «'ilh  the  aumunt  of  gninulcs  in  the  cell.  The 
aidrr  the  inner  tone  and  the  nion-  ahtindant  the  gmnulm  ihn  laricer  tbe 
unuant,  tbe  namiNcr  ihe  xonc  ntid  the  fewfr  ihi*  gntnulcs  the  smaller  the 
ftMMiut.  of  trffwinoLfn  ;  and  in  the  nufe»  of  old -■■«  tab  limited  Rtitultv,  wIm'TO 
lbs  (vrri'tion  m  wholly  inert  on  proleiilii.  the  inner  grnniilnr  kioo  u  alnonl 
fttMB  the  eelli.  AimI  the  same  paralleliain  Uiu  Wen  olidervcd  between  tJio 
aboadance  nf  ^ranalea  in  the  central  celh  and  the  'juantity  of  pepsinogen 
prvarnt  in  tbe  gitslrtc  glands. 

Tbe  [uarallelisni,  botrever,  at  all  events  in  tbe  case  of  the  iMiHtvm. 
ftppMUV  nut  to  be  ab^ilule,  for  it  ia  Maietl  that  in  tbe  paucrenH  of  dng«  af^vr 
InOK  lUrvation  there  i;)  little  or  no  iry|(>iuogen  in  tbe  gland  and  yel  (he 
odb  exhibit  a  niarktil  inner  n>ne  of  i;nimileA.  Moreover,  ue  should  not.  in 
•nj  eaiM>,  bejusiilied  in  concluding  ihnt  the  )i;mniileM  of  dte  pancreatic  cell 
ar*  whfdiy  coni[>oM:<l  uf  (ri'|Rinogen  :  for,  lu  we  ihall  pre^otly  aee.  the  pan-  ■ 
rreaiic  juice  coiitainii  l>eittde!i  tr^iwin  not  only  other  imniirtant  fernwrna  htil  ' 
a  In  I  certain  {irulcid  conslituuita;  and  the  granules,  which  are  of  a  i>mt«itl 
uUurr,  prolwbly  Hujiidy  (hrw  prolcid*  of  (Ih' juice.  Henoc  the  [Miriilleliitm 
between  gniuulm  and  tr^'pinflgni  !it  at  Ixvt  an  incomplete  < me.  Itnt  even 
•ueb  an  incomplete  pMrallclbm  \f.  of  value.  Th«  granule*,  whatcwr  their 
tuklure,  are  product*  uf  the  nictalxdium  of  the  cell,  lodged  for  a  while  tn  tl»e 
7«lliib*tancv  hot  ewntuallv  dtfcharged;  and  ccnain  of  (he  c«>n>tiiuent« 
of  ibe  M-vcral  tecrction*.  «uc1i  m  mucin,  (rypvin,  pc|iein  am)  ihe  tike  Bp|K-iir 
to  he  in  a  •imihir  uiiy  products  of  the  mflubotitm  of  the  cell,  l<Hlir<rd  for  a 
while  in  ibc  cell  Mitntiinc«.  not  in  all  cftim  exactly  in  lh«  condition  in  which 
tbcf  will  be  diKhargcl  from  (he  cell,  but  in  lui  antece^lcnt  phow  »ucb  ax 
ayogeu  or  the  like,  and  iu  all  ciues  ultimately  ejected  fri>in  the  cell,  to 
•nbpl*-  part  aixt  ^'nenilly  (he  imp'irl8n[  pan  of  Uw  secretion. 

t  8i9.    Tfit  itH  of  ttrriiitin   ilt'lf.     The  above  dtscutvion   prepam  ui  at 

ooM  tot  (be  MairnH'ut  that  (be  old  view  of  fecretion,  acoordin);  to  which  (Jm 

l^laad  picluont,  separatee,  secretes  (hence  tbe  nan>e  secretion),  and  to  filter* 

•■  t(  were  from  the  common  store  of  (be  bloo<I  the  several  oonaliluenU  of  the 

nice,  ia  uoleiuible.     According  to  that  view  (be  specilic  activity  of  any  on* 


I 


i 


I 
I 


848       THK   TISSUICS    ANU    UlfOnAKISMS  OF    niOKSTION. 


gliiiid  WAS  conliu«d  to  the  taak  of  letting  VLTljiiii  mngiitueiita  uf  tlie  blood 
p*B8  from  tlie  i^upillarita  Hurnftindiiifi:  ilie  alveoluM  lliri>Uf{h  the  cells  tu  the 
cbannelaof  itit^  ilnt-Ui.  while  n-l'uaiiiK  n  imwiiii^  to  otlierit.  We  iiuw  kiiuwr 
lh*l  certain  iiiiix^rluut  i.-ui»(itut:iita  of  tiacli  juiee,  tlii'  |Hnwiu  of  ;;adtrir  jtlioe. 
the  luuciu  uf  iuili<.-ii  unil  iho  liku  nre  rurmuil  in  the  i^i-li,  atnl  i)i>t  obtAJned 
ready  made  frum  lli«  blooil.  A  mintit^t  i|UHOtily  iit'  [H'juiii  dii«>  exidt  !t  b 
true  ill  the  blood,  but  th<'re  nn:  n*»"nt  for  thinking!  ihni  ihl-  liu*  tniule  iu 
WKjr  b«<:k  into  thi.<  blixul.  ).-ithiT  \».-'m^  nWirln-d  from  tbt^  liitt^rior  of  the 
Btoinai'h  i>r,  u«  xn^nu  innti-  priil>iible,  pii'krd  u|>  dinrctly  IVoin  lli<!  ]|^trio 
Cluida  1  und  «m  witb  mime  of  tliv  other  iDtiiitititciil"  of  other  jiiiitts.  The 
t'hief  or  siwelfic  eon»tit>ienl«  of  wieh  juice  lire  formeil  in  ihc  wll  itMlf. 

Hut  tht!  iuioc  Bocrotcd  br  any  glatid  ooiu>i«tfl  not  only  of  tb<-  Mpi^ltic  Mib- 
stuticu*  Niion  ail  mucin.  |)cp6iii.  ur  other  tcrmciil.  or  other  b>»ti«.  found  in  it 
alone,  but  also  of  a  larg^  i|unnlity  of  water,  and  of  vuriuuv  other  Mb- 
nianotw,  chiefly  inline*,  cotntnoii  to  It.  tn  other  juices  and  to  the  bloo).  And 
the  ijiii9'lii>u  ari»e.f.  Is  ibe  irater.  are  the  saltA  and  other  common  Bub'tauco* 
fiirnmbcd  by  tile  same  act  ns  that  which  supplies  the  specilic  GoD»tiliteHt«  * 

(V-rtjiin  facts  au^roat  that  Lli«y  are  not.  For  instance,  m  meiiliuiied  fomt 
linw  a)^i,  in  lh«  auDRiaxillary  ifland  of  llie  dug.  stiiuulatiaii  of  the  chorda 
tym|»ni  produces  a  copious  (low  of  saliva,  which  is  usually  thin  and  tinipid, 
while  Klimutatioiiof  the  oervicaJ  sympathetic  produces  a  scanty  llow  of  thick 
vikfid  Mliva.  Thai  is  to  aay,  atimulation  of  the  chorda  has  a  marked  cifed 
in  prorootJn<;  the  dboharge  of  water,  while  Blimulation  of  the  sytnpathelio 
has  a  marked  effect  iu  prumotinK  the  difcharKe  of  mucin.  To  this  w«  may 
luM  the  caaw  of  the  parotid  of  the  do^.  Iu  lliii>  K'*^od  Btimulati»u  of  a 
cenbro-sptoal  nerve,  the  uuriculo-temporal,  prodtiees  a  copious  flow  of  limpid 
•alivK,  while  Mimulaiion  of  (he  sympuiht^tii-  proilucea  itself  little  or  no  secre- 
lion  at  all;  but  nhen  the  nymjMtiliutie  anil  the  oerebro-spinal  nerves  are 
Htiniulated  at  the  name  lime,  ihi'  mlivu  which  Aam  is  much  ticker  in  sulid 
and  eftpecially  in  organic  mallrr  than  when  the  oi'^rebro  spinal  nerve  is  stimu- 
lated aloue.  And  we  have  nlrcjulv  iwcii  tliat  in  t hi*  gland  the  microscopic 
dianges  foltowio)^  upon  »ympathi.tie  !«timulatii>ii  arc  more  conspicuous  lluui 
tboee  which  follow  ujion  <x>rehro'i'piiial  ncimiilnlion. 

These  and  other  facU  have  led  to  tha  corici^pltoit  that  tlie  act  of  aecretloii 
cuiuiata  of  two  ]>arls.  which  in  one  oiw  may  coincide,  in  another  may  take 
place  apart  or  in  diKercnt  proporliuiu^  On  the  one  hand,  tlicr«  is  die  t)i«- 
cliarge  uf  water  carrying  with  it  common  eolublv  substancH,  chiefly  "aliacs, 
derived  from  tlie  blood ;  ou  the  other  band,  a  metabolic  activity  of  the  oell- 
aubBtaoc*  ^vce  rise  to  the  speciHc  constituents  of  the  juice.  To  put  tbo 
niait'T  hronitly,  the  lallcr  proce«  produces  the  Spocilie  conxtiluentis  the 
i'liruier  wa«)ics  ihe^e  and  other  matters  into  the  duct.  It  has  been  further 
ippoaed  lliat  tno  kioda  of  nerve  libree  exist:  one  governing:  the  former 
•nd,  in  the  case  of  tlie  submaxillary  aliuid  for  inilance.  prei>on- 
cratini;.  though  not  U>  the  total  exoluMOu  of  the  other  kind,  in  the  (chorda 
tympani;  the  other  ^nveming  the  latter  iiroceos  and  pre|>onde rating  in  the 
branches  of  tlte  oeri-ical  syinpetJietic.  'Iheee  have  been  called  respectively 
"  tAcretory  "  and  "  tnipbic  "  librea :  but  these  terms  are  not  desirable.  It 
may  be  here  remarked  that  even  the  former  prue«u  is  a  <iistinct  activity  of 
tlie  gland,  and  not  a  mere  iriRltration.  For,  mt  we  have  seen  in  the  caw  of 
the  salivary  j^laiid*,  when  atropine  U  given,  not  onlr  do  the  Mpeotfie  cunfititu- 
enta  ccttse  to  1m:  ejected  iw  a  council  ueiicc  of  Ktimiilatiou  of  the  chorda,  but 
the  discharge  of  water,  in  spite  of  tlie  bluiHlvtwM'ln  bccominjE  dilaUrd.  in  alMo 
arretted :  no  Niliva  at  all  leavco  the  gland.  And  what  is  tnie  of  the  salivary 
IcInmU  a*  n-gards  the  ihixjiilfuue  uf  the  (low  of  water  ou  sonielhing  cIhc 
liaidcs)  the  mere  pretMirc  uf  the  blond  ia  (he  bhwdveMcU,  ap|ic4tr«  t^i  hold 


CHAKOES   IK    THK    OLAKPS. 

i)  wit}i  oilier  ^■IniidH  aW  Indeed  il  bua  beni  ■ii^'trf*I('<l  tlmt  i)>i-  wry 
(liflcburge  of  wuler  \»  due  lo  nn  aclivitr  of  (he  cell  ;  llio  hyjxittiesis  liii?  \>vrn 
put  forward  (bat  i-liiini;eit  iu  lli«  mU  give  riwe  lo  tb«  fnrniiiliaii  iu  tbii  crll  of 
aubelances  nbich  nlvurb  water  fnim  tbe  hloiMl  or  1yni]th  on  lh«  mu:  nido 
and  p\t  it  up  on  (he  other  ud<-  into  the  liinM^n  uf  the  iilTeoluft.  (•iii-h  no 
b]rp(>tbeniii  cantiut  h«  regard«il  a*  nrovccl ;  but  th«  Di«re  ixitliiig  it  forwiinl 
nilsea  doubt*  t\»  li>  lh«-  validity  or  tlu)  distinctioD  on  uhich  wo  haw  bcvn 
dwellino;;  ami  other  rtiiinidi'rationK  point  in  th«  itanie  direction,  For  in- 
tiaiuv,  if  the  common  Miluhlc  )«lls  jinycnt  in  n  juirc,  nn  <ti(>liiiguishi-'l  from 
(he  ■]i4-cific  (itnntitiiciili',  wrm  iiifn'ly  curried  into  ihr  jiiicc  by  th«  rusli,  «o 
to  H[icak.  of  wut<-r,  wt-  nhotilii  expect  lo  ttiid  llir  pereentiLg«  of  tbcM)  ults 
rillur  nninining  llio  wimo  or  perh«]M>  dccn^iwing  when  the  juice  wjw  ttccreted 
more  rnpidly  nixl  in  fuller  volume.  Kut  under  (hew  drc-utnEliincev  (he  per- 
C4-nIiige  ven>'  frcr|uently  incmutn:  and  in  genrrnl  uc  lind  cbnt  under  various 
drcLi»i»tiiiices  tliP  proportion  of  ealta  Bccretetl  to  (he  quantity  of  iriilcr 
M-erctcd  mny  vary  constderably.  Obviously,  nhilc  sumething  determines 
the  'pinniit}-  of  wnt«r  pusing  into  ibo  alveolus,  something  eloe  determines 
bow  tDHcb  of  common  »oluble  enltt  that  water  contains,  and  Still  something 
else  determin^B  to  what  eilent  that  water  is  also  laden  with  8p«oi6c  coostitu- 
eni«  and  other  organic  bodies.  Tbe  whole  action  is  too  complicated  to  be 
described  as  conebting  merely  of  the  two  proeeeees  meniioued  above,  but  the 
time  has  not  yei  come  for  clear  and  delinite  statements.  Everything,  how- 
ever, tends  lo  show  that  the  cell  is  the  prime  agent  in  tbe  v  bole  biiainew, 
iJiongb  ue  cannot  ai  present  define  the  nature  ol  the  several  changes  in  ihe 
cell,  nor  can  we  sav  him  these  chenge«  are  exactly  related  lo  each  other,  to 
changea  of  the  bfood-prcMure  in  ihe  bloodvessels,  or,  we  mav  add,  to 
chnnges  taking  place  t»  the  lyniph-9pace«  which  lie  lietweeu  (fae^locHl  aud 
the  cell. 

We  inajr  perliap*  add  that,  vinre  in  certain  culaneous  secreting  glands  the 
alveolus,  or  what  eorre«ponda  to  the  alveolus,  is  wrapped  nmiid  with  plain 
musctilar  fibreK,  the  contraction  of  whith  upixnra  to  force  th«  secretion  out- 
ward, the  idea  hiiti  been  suggcMed  that  in  glands,  such  nn  we  are  now  con- 
sidering, Ebe  oeU-*ub*tance  making  uve  of  "  pixKoptaxmic  "  contraction  in- 
stead of  actual  mui>cular  contraction,  may  force  part  of  the  cell  contents 
into  (be  lumen  of  the  alveolii*.  Such  a  mode  of  wcrelion  woviUl  lie  ci>m- 
parable  to  tbe  ejcclion  of  iindigtvted  maierial,  or  "  vxcrvtion,"  by  nn  nma-bu- 
Kut  we  have  no  witiafuctory  evidence  in  favor  of  thin  view. 

S  240.  Throughout  the  above  wc  have  wjokeii  tu  if  the  secretion  were  fiir- 
Disfatd  exclusively  by  the  ceJls  «f  the  alveoli  or  secreting  portion  of  the 

S'and,  as  if  the  epilhelium  celU  lining  Ihe  ducts,  or  couducting  portion  of 
e  gland  contribulcii  noihitig  to  the  act.  In  Uie  gtutnc  ghtmU  tb«  slender 
cells  lining  Ihe  mouths  of  tbe  glands  (which  correspond  tu  duels)  and  cover- 
ing the  ridges  between,  arc  mucous  eclls  sccroling  into  the  stomach  gener- 
ally a  small,  but  under  abnormal  conditions  a  large  amount,  of  mums, 
which  haa  ils  ueea  bat  is  not  an  essential  pari  of  tbe  gaxiric  juice.  In  the 
salivary  glamU  we  can  hardly  suppose  that  tlio  long  sirelch  of  ehanicler- 
istic  coluuiuar  epilhuliun)  which  reaches  from  the  alveoli  to  tli«  mouth  of 
tl>e  long  main  duct  serves  simply  to  ftiraish  a  smooth  lining  lo  the  conduct- 
ing Mssages;  hut  we  lisve  as  yet  no  cleflf  indications  of  what  tbe  function 
of  tills  epiU>etium  can  l>e. 

§  241.  Before  we  leave  the  mechanism  of  accretion  there  are  one  or  more 
mrcMHiry  txiiiils  whi<;h  deeerve  attention. 

In  In-aiing  just  now  of  the  gastrio  glands  we  spoke  as  if  pep«n  were  Ihe 
only  iin|K)rtaiit  conaiitueul  of  gastric  Juice,  «fa«ms,  as  we  nave  previoualy 
seen,  the  acid  it  etjUBlly  esseulial.     Tbe  fonuBlion  of  tbe  free  8ci<l  of  tbe 


B 


TlIK    TISSCES    ANU    Ml 

KWlric  jtiioo  U  i'«ry  uWure.  nuU  luaiij  injftniouB  bul  tiusalMlactorr  vi«irt 
luive  bo«n  |nii  foruanl  lu  «xplaiii  it.  It  tteema  uaturnl  to  sujifHr^e  tbat  it 
nriaeH  ill  aonie  way  from  the  deconi)i<>i«iti<iu  nf  Hoitiuin  chloride  ilrnwu  fnia 
lti«  blood ;  ami  tait  h  xupportMl  by  iL*:'  I'ui-t  that  uUkd  the  aecretiim  i>l'  k*^- 
trie  juice  i.i  aL-tlvi-Iy  tciAii^  on,  tlic  niii'iuiil  of  clilnridM  leaviti);  the  Muoil 
by  Uie  liiilnvj^  u  [iru[>orUi>uHldy  tjiniiii'igilieil :  liiit  it>ithio^  deliuitv  mil  M 
prMenl  be  MMtxl  ui  in  (he  luechiiiiiKni  of  ihnt  il(!i-(iiii|H:ditiou.  An<t  even 
■dmlttiiiK  thxt  the  wdiuin  chloride  of'  the  hvly  ai  tarjic  i*  the  ultiriuil« 
■ource  c)1  the  chloriiKi  eleiticnt  of  ibc  aciil.  It  uppi^nni  imire  likely  tliut  that 
element  Kitoiild  be  t*l  frcv  in  the  Htumacli  liy  thn  tli-coiuiXHiiliiHi  i>l'  miiot 
liighlv  complex  and  uiuilithle  chlorine  compound  ]>rcviotiily  2fncrnt<.-d.  than 
llmi  it  should  arise  hv  the  direct  splilling-iift  i>l'  w  (tabic  a  Wlr  n*  Kinlium 
cblorido  nt  the  very  tiino  nhm  the  acid  ie  nx-retcd. 

In  the  fn>g,  while  iKpfiiii  troc  tVoin  aciil  if  i^ecn-ttil  by  llic  g)iin<ls  in  the 
lower  {xirtion  of  the  irMijihatjus.  an  acid  Jliim-  '»  uffinled  by  gland*  in  ili« 
atoiwaL'ti  ilBcIf,  which  have  accordingly  been  cidlcd  o^gntic  (^'Vi-o  to  sharpen, 
ncidulaic  I  glands  ;  but  ihrac  oxyniic  |>lim(U  appear  also  to  secrete  pepsin. 
In  the  niainmal  tlie  Uolnlcd  pylonit  «ecrct«8  au  alkaline  juice;  in  tact,  (be 
anpearnnce  of  an  acid  juice  is  limited  tu  tbo»e  iMrtions  iif  the  stomach  in 
u^iich  the  glands  coDtaiu  both  "cbici"  or"ceDtml,"  and  "ovdd"  or  ■■l>i>r- 
der"  ccUb.  Now.  flrom  what  lias  been  previously  Mid,  tliere  can  be  ik> 
doubt  (hat  (be  chief  cells  do  secrete  pepain.  On  the  other  hand  there  is  nu 
evidence  whatever  of  the  formation  of  ne|aia  by  the  '■  border  "  or  "ovoid  " 
eellH,  though  this  was  once  suppoaed  to  ne  the  case,  and  thcae  oelU  were  un- 
fortnnntely  formerly  called  "  pe]>iic"  cells.  Hence  it  has  been  iufern^  thai 
ilw  bonier  oelU  fti'vreie  acid  ;  Imt  the  arKUiiieiK  is  at  ]>rewn(  »iie  of  exclu> 
itigii  only,  (here  being  no  direct  proof  that  thaie  cells  actually  numufitctun 
tlic  acid'. 

The  rennin  an)ieani  to  be  formed  by  tlio  same  oellA  which  manufacture  thi 
|Mip*ln,  that  is,  by  the  chief  r<-ll.->  of  thd  fuudun  gi'iicmlly.  and  to  »omo  ai 
tent  !>;■  the  cells  of  lh«  pyloric  glands.    We  may  mhl  that  we  liav«f  ovidMlD 
of  the  cxiKieiK'*  of  A  lyinogcn  of  roniiin  aiinlogoun  to  the  lyaiagi-n  of  [lepaii 
or  of  trypnin. 

The  muoiis  which  is  prei^ent  as  n  thin  layer  over  the  surface  of  the  fiutiog 
fltoitiach,  and  which  eitpccially  in  hcrbivoroiw  animals,  is  increased  dur~"* 
digestion,  comes,  as  we  havr>  siijd,  from  the  niuoiis  veils  which   line 
iiiiHitli^  iif  the  Hcvcral  claniU  and  cover  the  intervonitig  eurfac«S. 

!;  243.  We  previoufFv  callc^l  ntli^ntion  (o  the  fact  that  in  the  cose  of  the 
oraach  the  afasorplion  of  the  product*  of  digestion  largely  increased  the 
elivity  of  ihe  iwcretint;  colls.  This  has  led  to  (he  idea  that  one  effect  of 
fixnl  h  to  "eliari^"  thej^slric  celU  with  pepiiiogen.and  that  eerlain  arliclw 
of  fiKHl  might  be  considered  as  eipecinlly  jieptogenous,  t. '.,  conducive  to  lli« 
fomiatiou  of  pej«in.  .Such  a  view  is  templing,  but  needs  as  yet  to  lie  more 
fully  siippiirCed  bv  facts. 

§  243.  i-^N!tng  the  gtvat  solvent  jtower  of  both  gastric  aud  pancreatic  Julc 
the  tpiitxlion  is  naturally  fluggmtml.  Why  does  not  tJie  stomach  dtgett  it«clfr 
AA*!r  di-nih,  tbo  stomach  is  tretjiieutly  found  iiarcly  digeated,  vii.,  in  case* 
when  death   has  taken  place  suitdeiily  on  a  lull  »toma4'h.     In  an  ordinarf- 
diiilh,  the  niemhmne  ceasea  to  aecret*  before  the  circulation  i."  iit  an  enttj 
That  ihrrc  is  uo  niirctal  virtue  in  living  things  which  pn-vent*  their  beini 
digi.-Kt^'Kl  is  shown  oy  ibe  foct  that  tlio  leg  of  a  liviu^i;  t'rog  or  the  ear  i3 
IV  living  rabbit  intrixlucetl  into  the  atomach  of  a  dc^,  through  a  ganrioj 
fistula,  is  readily  dig««tvd.     It  lins  been  tngEOslcil  that  the  blooil-current' 
kwjm  up  an  alkalimtv  lulKcicnt   to   iicuinilTxe   the  ncidiiy  of  the  juice 
in  Ibe  irgioo  of  the  glaiidn  Ibemselvtv;  hot  this  will  unt  explain  why  the 


I 


Mtii!  jiiici.'.  whirli  in  iiiriivi'  ill  nti  iilkaltoc  neilitni),  iIim-*  iiiit  ■lii.i.'wt  iliv 
ills  o1'  lin-  jmurrcii*  it»":lt',  or  «liy  tHo  diMattvo  wIU  »f  tin-  lituodlcss 
uciitiu»Kiii  or  hy<iiv»"in  <ii>  not  Higcrt  llK-nw^nri*.  \Vi-  mijrht  ikIiI.  it  iliwn 
not  exriinin  nhy  lh«  iiinirbii,  whik-  diMoIving  the  |iri>tn| ilium  or  (lit-  dvrnU 
lowed  iliiitoiu.  dim  niA  dissolve  it«  own  )ir»U>put>ni.  We  mniiot  Amnrvr  lliLt 
question  u  alt  tit  |ir«BeDl,  itiiv  mnn.^  thnn  Ihe  iimilnr  one.  wliy  Iho  delic«l« 
lirntoplasm  uf  the  iniwba  r^wiste  during  life  tlw  entninc-e  into  itM.Of  liy  uemout 
of  more  water  tlinii  it  re*|uiree  to  carry  on  its  work,  while  n  Tew  nioineot* 
after  il  is  dend  natereDtenfreelr  hyosoioel^,  audiheedectsof  that  eiiimooe 
l)«vome  abuiiiIaDtiy  evident  l»y  the  fomialioii  of  bullw  and  the  brenkiuK  u|> 
of  tlte  i>r<>io|t1iigtu. 

Toe  Propkrtiks  asd  Charactees  op  Dile,  I'axcrbatkt  .K-ice  and 

SuOCUfl  ExTRlilCTS, 

I  844.  In  (he  Hvin^-  hmly  the  titotl.  Btibje<1ed  1o  the  artinn  first  of  tlw 
mltva  and  then  «f  lh<.-  niutriv  jiiir«,  underKovn  in  lli«  stomafh  i-)mu)!;i,ii  whi<rh 
wf  ntiall  (irvwritl)'  ('i>i»id4-r  in  (U.>tail,  and  tin-  foud  mo  cliiiii^'^l  i.«  iiaAMed  on 
into  the  iminll  intn>tiiii',  nhrn^  il  iii  furlhi-r  iivihj«i<t«d  li>  thi:  B<'tii>ii  iif  tlK-  hiln 
iM-crotwt  hy  the  livi-r.  of  iNincrvatic  juice  .■xn.tvsIi^'I  h^-  the  piincreiw,  and  prw. 
sibly  to  »»nK-  rxli-nt,  though  Ihiit  hy  no  nicium  certnm,  of  a  jiti'r  ««rrcti.-d  by 
the  intestine  iiM-1f  and  cnlTed  luwu*  tntrriftu.  It  will  be  oonvcnionl  to  iftudy 
thv  ininiile«lriii-iiire  of  the  liver  in  cuitneet ion  with  other  fiinctinm  of  the 
liver  more  inijiortiiiit.  perhup*.  than  tJint  of  the  M-crotion  of  bile,  nnnivly, 
Ihe  fbrmali'in  of  glycogen,  aiid  oth^r  nietnbiflic  eveni«  occurring  in  the 
hepatic  eellt;  we  have  already  ttudied  (he  structure  of  the  rancrens:  nnd 
the  etructiire  of  the  intt«linc  will  betil  be  i-onsidoivd  by  ilselr.  We.  there- 
fore, turn  at  once  tii  the  ])ro])ertiee  and  characters  of  the  above-nanicd  juice*. 

Bitr. 

Tboujfli  bile,  after  secretion  in  the  lobules  of  the  liver.  It  puted  on  nlon^ 
tlie  lK-|Nitic  duel,  it  in  in  the  case  of  uinat  animals  not  poured  at  oncp  into 
tlH-  dumlenum  but  taken   by  the  evstie  duel  to  Ihe  i««erv»irof  the  j^uU- 
bladder.     Here  it  remain*,  until  suco  time  ai  it  id  needed,  when  a  ijuiiiitiiy 
b  tioured  aloii);  the  common  bile  duct  into  the  intestine. 

The  'jualiiy  of  hilo  vuritn  much,  not  only  in  dilfbrent  animalit.  hut  in  tlie 
name  animal  at  diirvrt  nl  titiico.     Il  i-"  moi-covi-r  airecli-d  by  the  li-n^lh  of  the 
•iijoorn  in  thf  gnlMilnddi-r :  bilr  Inkc-ii  direct  from  the  be]Mitii:  duct,  <v|M)- 
cially  when  «ci'ri'lril   rii|iii|ly.  ivininiii*  little  or  ik>  tnueiu;  that  taken  fr>>ui 
tite  gall'blailder,  ati  of  ulinif^htcri-il  oxen  or  i>h(^'[i,  \»  loadwl  with   muciu. 
The  col'ir  of  the  bile  of  caruivoriiiiM  mid  omnivorouii  animals,  ami  of  man, 
J  [s  gem-ratly  a  brigin  i^olihn  red ;  of  herbivorous  aniniul»,  n  yellowish  gr««n, 
or  a  bri}:ht  green,  or  n  dirty  gravn.  according  to  circum«tnMCw,  being  much 
nii-dili<  <1  by  n-tenlion  in  llic  gall  bindder.    The  reaction  in  nculr>il  or  alkaline. 
The  f-'lJifwinL'  niav  1h-  taken  as  the  average  composition  of  human  bile  taken 
from  the  gairbbdiler,  and  ilicf<>rc  containing  much  more  mucus  as  nell  na, 
relatively  to  the  AoIid«.  more  water  tliUD  bile  from  the  hepatic  tluct. 

Ill  ti>ni«n>. 
Water  ,-....,  IWli.a 

Ho)>iU: 
Ilile.^uii»      .......  91.4 

Fai».«lc.      ,  ,  ,  .  .  ».« 

Cliolwleriti  .  .  .  .  S.8 

Mnciu  nixt  rt|ini>'iit  20.8 

Inorganic  IIniIi>  ,  .  7-^ 


S52      THK  Tiastjj 


lOKSTIOl 


The  vatin  abMticv  of  prolcids  it  n  mnrkcl  luilurc  of  kil«;  (ttincnnitic 
juicv,  ii»  ««  ehall  era,  coJitaiDs  a  coDiitlcnibte  ijtinnlUT.  mlJva,  m  wr  havu 
Been,  d  small  <|uantily,  normal  guetric  jtiioe  probnl>ly  «iill  lew  aikI  l>ilc  noiia 
■I  all.  Evt'n  the  bile  which  has  been  retained  eonie  time  id  ihc  gall-bladder, 
tliOBgli  rich  in  niucuB,  coiitains  no  proleids. 

The  cooUitueDta  which  form,  apart  from  the  mucue,  lti«  great  bulk  of  the 
Rolids  of  bile,  and  which  deeerve  chief  alieolion,  are  the  pigmeoif  and  lh« 
bi1»sRlta;  of  ihcK  we  eball  apeak  immediately. 

With  regard  to  the  iiiorgauic  aalta  actually  present  as  auch  sodium  salts 
K»  compicuouM,  flodium  chloride  amouutiu^  to  0.2  or  more  per  cent.,  sodigia 
pho^hate  to  uearly  u  much,  t]>e  rut  beiug  eartliy  phosphates  aud  other 
imitt<-n  in  unM  i|uniitity.  The  presence  of  iron,  to  Ihe  extent  of  abom 
O.OOB  |icr  c«nt.,  U  iDtereMin^,  since,  as  we  !>liall  tee,  them  are  reaaoos  fc 
thinking  thiit  i\u-  iiigtiient  of  bile,  itself  free  from  iron,  ih  dfri\'e<l  Trom  iron 
holding  hii-iuoKlohm  ;  woine.  at  Wst,  of  the  in>u  net  free  during  the  cmver 
MOB  of  bBaaoglobtD  into  biln  pigment,  wliic^h  pmbiihly  takm  plane  tn  the 
llTer,  finds  its  way  into  llit-  bile.  Bile  ik]«>  ariiH-an  to  ixuilain  a  •inuU  •|uan- 
tity,  at  all  cvcntx  oc(7i»i<>nBlly.  of  »lhcr  m<-Utl«,  such  as  mansuicse  and  cop- 
per; mrltiU  iiitnidiiccd  into  l)ie  hoily  art'  apt  to  be  retained  in  tile  liver  and 
evenluiilly  Icnve  it  by  the  bile. 

The  imuil  quantity  of  fat  pruicnt  consiata  in  part  of  tbc  complex  bodj' 
lecithiu- 

The  peculiar  body  thotffterin,  which  though  fatty  looking  (hence  tlie  Dimt 
"  bile  tat ")  is  really  an  alcohol  with  the  composition  0^11^0,  is  conspicuouLi 
by  its  quantity  and  constanev.  It  forms  the  greater  pan  of  most  giUl-MoDes, 
though  some  are  composed  cbieflv  of  pigment.  IniMliible  in  water  and  eoM 
alcohol,  ihouf^h  soluble  in  hot  alcohol  and  readily  soluble  in  ether,  cbloro- 
forni.  etc..  it  is  dissolved  by  the  bile-salts  in  aqueous  eolulion  and  hence  la 
prcwnt  in  solution  in  bile.     Its  physiological  fuDctions  are  obscure. 

The  ash  of  bile  conuslB  Itu-gely  of  soda,  derived  partly  from  the  sodiun 
chloride  stid  partly  from  the  bile-salts,  of  sulphates  derived  chiefly  if  not 
wholly  frum  the  tsiter,  and  of  phosphates  partly  ready  formed,  and  iu  part 
dvriveil  fnicu  the  lecithin. 

§  245.  I'itpnenU  uf  bite.  The  natural  ^Ideii-red  color  of  normal  human 
or  oiniiviirous  bile  is  <Iue  to  the  j>re9ence  of  bilirubin.  Thitt,  which  ia  alao 
ibc  chief  pigmeniary  eoDHlJtiieiil  of  gall'iitoue«,  and  occunt  lar|^ly  in  th« 
urinsuf  jaundice,  may  be  obtained  in  the  form  either  of  an  orBn^oolore<l 
aroorphoas  powder,  or  of  welt-forniHJ  rhotDbi<^  tableti*  and  oritinis.  lu- 
•olublc  in  water,  and  but  little  iwluble  in  I'tbi^  und  nicciho],  it  iti  rcAiUly 
soluble  in  chlonjfDrm  mid  in  alkaline  fluidx.  Its  coiniiiwilioii  i»  C,tH„N,0|. 
Treated  with  oxidizing  »£«»!»,  mch  m*  nitric  acid  yellow  with  uitrouv  ncia, 
it  di(|)layifainiccnsionof  coloTH  in  tho  urdor  of  the  xpectruiii.  The  relloaitih 
golden-red  becomes  srran,  this  a  KrcfDish-blue,  th<-n  blue,  next  violi^t,  after* 
ward  n  dirly  red,  iind  Rnally  u  pale  yellow.  This  cbn meter i»tic  n-action  of 
bilirubin  is  ihc  biieie  of  the  K-callcd  (imeliD'ii  tott  for  bile- pigment*.  Each 
of  these  Mngvs  reprcM-ots  u  distinct  pigmeiiturr  vubslance.  An  idkalino 
■ululioM  of  bilirubin,  cxpuwd  in  a  ehallon  VMsei  to  the  action  of  the  iiir, 
turns  green,  becoming  converted  into  bitirerdin  (C„H„N,Oi  or  C„H„N.O^ 
Maly).  the  given  pigment  of  herbivorous  bile.  Bilivorain  is  also  found  at 
times  in  the  urine  of  jaundice,  and  is  probably  the  body  which  givt*  to  bile 
which  hns  bceu  exposed  lo  the  action  of  gastric  juice,  ss  in  biliary  vomits, 
its  chiamclcTielic  green  hue.  It  is  tlie  tirst  time  of  the  oxidation  of  bilirubin 
in  Uuielin's  test.  Treated  with  nxidiiiu);  agents  hiliverdin  midh  ihroueh 
tlie  same  series  of  colors  as  bilirubin,  with  the  exception  of  the  iniiwl 
golden -red. 


BILE. 


358 


$  S48.  Tkf.  bile-so/lA.  ThflMO0iuiM,tn  nauaBd  UBOy  animaU,  orWi'tin 
g/tfroekotttf:  and  taio-ofJiolaU,  the  proportion  of  the  tiro  varrlDj;  in  (liilerent 
lUiiiiiklit.  In  ninn  bolh  tlii!  total  t|uaulity  of  bile-Maltn  and  the  prftjiortion 
iif  tli«  niic  bilt^-Kult  to  tliu  (ittivr  mh.>iii  lo  vury  ii^^d  dcjil,  Wt  thc^lTc^icliolale 
n  im<\  to  bv  alKnya  tbi;  muni  iihiitidiint.  In  ox-^iill  tuilium  glyi-ixTlioUti.-  in 
alwDdant,  nnd  laiirochQliUv  Kcnaty.  Tho  bile-mlts  of  the  il(>f(,  mt,  boar,  itii'i 
other  i-itrnivora  <y>n»iMt  rxcliiHivcIf  of  the  latter. 

Insoluble  in  ethor.  but  mlublo  in  nlcohni  mill  in  wittvr,  the  Mqueous  nulii- 
tiuiM  having  a  decided  allcAlint?  ronction,  both  wilu  mn^  be  obuined  by 
cnittiilliution  in  Rnv  nciculnr  n«edle4.  They  nre  «xoee<lin};lT  ib-liquiiicent, 
tdv  Mlutioiu  of  both  acids  havi<  n  dextro- rotary  action  on  [Hilnrinil  light. 

AyporafMM.  Bil«,  m)x«d  with  animal  charcoal,  la  evajporatod  to  dnrnrw  and 
•xtncidJ  with  aloihol.  If  not  coIorlcM.  th«  ulcohniic  nitrate  miwt  bo  fiirtlict 
deootoriiccd  witli  ntiimiil  charcoal,  and  the  alcohol  diatilled  iT-  The  dry  reaidue 
ie  treated  with  abiwluie  alcDhol.  and  to  the  ak''>haUu  filtrate  anhydrous  ether  la 
added  as  long  as  any  precipitate  Is  rormed.  On  standing  l)ie  cloudy  ]>rocipiut« 
bocooiM  traiMfermed  into  a  crystalline  mas*  at  th«  bottom  of  tlto  ve«vl.  If  the 
aleohol  be  not  alMolute,  tlin  crjoliilii  are  v«jy  apt  to  Im  chanmd  Into  n  thick 
syrupy  fluid.  Thi*  maas  uf  cryitaU  baa  been  often  Hpolcen  of  as  iUi'a.  Bi^th  »alte 
ar«  Uius  predpflated,  so  that  la  such  a  bile  as  Uiat  ol  tLe  ox  or  man  blllD  coa- 
■istH  boib  of  eodiam  f^lyoocholate  and  sodium  taiirncbo1nt«.  The  two  may  bo 
Mi-lnKiiliil  by  |)rcrii>itauon  fmra  their  aquoou*  solution*  with  luirar  of  Icuil,  which 
thfiwA  dnnn  the  fonner  much  more  r«adUy  than  the  latter.  Tb«  acids  may  be 
se|>ur-jii(-ij  from  tliclr  raR>eutive  uilla  by  dilute  sulphuric  acid,  or  by  the  action  of 
lead  Ac^tlflte  and  sulphydrlc  acid. 

On  boiling  with  dilute  acids  (sulphuric,  hydrochloric),  or  caustic  potniih 
or  bar^'ta  water,  glycocholio  add  in  split  up  \nu,  eholalk'  (cbolio)  acid  and 
f^lycin.  Taurocholio  acid  may  Himilarly  ite  itplic  up  into  cholalic  acid  and 
Uurin.    Tlius : 

4R)rroeliciU(i  a(M4.  CboUllaaoU  niyidii. 

C>H„NO.  +  II,U  =  C„H„Ot  +  OH,,NII,  ia).OH). 

TkaroGhollv  Mill,  CbodsUcatdd.  lUiiila, 

C^UuXSO,  +  H,0  =  C«H„0,  J-  cn,.N  HrSO.H. 

Roth  acids  contain  the  aBine  oon>nitrogeitous  add,  oholnlio  acid ;  but  this 
Mid  \»  in  iIm!  firu  case  awociatcd  or  conjuMtcd  with  tlie  impnrlnul  nilro- 
l^uous  body  glyoin,  or  amidn-aoetic  aciil,  wliiuh  is  a  conipuunil  formod  from 
■unmonU  nud  one  of  tlie  "  faitv  acid"  iH.'ri4!e,  vix.,  acetic ;  and  in  the  second 
MM  with  taiirin,  or  am ido- bar ili ionic  acid,  that  ix  a  rarunound  into  nbioh 
reprcacntflliviw  of  ammnniu,  of  the  ethyl  gnmp,  and  of  nulphurtc  acid  enter. 
The  deoompoeitiflQ  of  the  bile  aci<la  into  chololic  acid  iiaa  tiiurin  or  glycin 
rvefwctiToly  take*  place  iinlurally  in  tne  intcetinc,  the  gtyciu  and  taurin 
Lbving  probably  absorbed,  m  that  from  the  two  acids,  aRor  they  have  e«r\'cd 
Itbcir  purpott  in  diireaiiuQ.  the  two  amnii^nia  coin|munds  are  nturued  itil'>  the 
IiIoikI.  FmcAx  of  too  two  acids,  or  cbolalic  iieid  alone,  wlion  Ireatett  ivith 
sulphuric  odd  and  cnne-sugnr,  giveaamagnilicunt  purple  color  { Pelceukuler's 
IMi),  with  a  cliarocUjrislic  spectrum.  A  HniUnr  color  may,  however,  often 
be  prodncol  by  the  notion  of  the  same  bodiei  on  ulbumin,  amyl  alcohol,  nnd 
eome  other  organic  b'.H}ic«. 

$  947.  Adion  of  bile  on  j'ocni.  In  mate  animnb  at  least  bile  contains  a 
ferment  capable  of  con  verting  starch  into  sugar;  but  its  action  in  ibis  reapoa 
is  wholly  Hibordiuate. 

On  proteids  bile  has  no  direct  digeetiro  action  whaterer.  but  being,  gen- 
erally at  lea&t,  alkaline,  and  often  strongly  eo,  tends  to  ueutrolixe  (he  acid 


354        THE   TI88UK8    AND    KROHANISUS   OF    DltlBSTIOir. 

oonUuta  of  Ibe  slomiicb  aa  tbejr  ftm  into  the  duodeuum,  and,  u  «•  thall 
•M, »  j>r«pai!««  the  way  for  the  acUon  of  the  inncnealic  julc*.  To  peptic 
notion  It  is  disiinctly  tiniaf^iiistic:  ibe  {iresence  of  a  Miflidirnt  <|ua»tity  of 
bik  reudere  K^^n*^  juice  iuert  toward  [irotddti.  Morcurer,  wh«n  btk-,  or  a 
eolutkin  of  bile-8ait«.  ia  added  to  a  fluid  oontaiiiing  ilie  jiroduviii  of  giMtric 
digtiriJon,  a  prvdpitate  take«  place,  voDiistins  of  ]>arnpi'i)tMiin  (wh«n  pn^ent), 
p«pto<u%  {M-iKiiii,  ajid  bilv-nultA.  The  preoipitatt!  i»  mbiuuilvn]  in  an  cxcos 
of  bile  or  wolmiou  of  Mlcnnlta ;  but  the  pepain.  tbou);h  n-ilimolvcd.  renuaina 
inert  toward  proteidn.  Tbw  |>rvcipiiaii<in  nntiially  <liiii>  lake  place  in  tbe 
duodciiiini,  aiid  yiv  ^linll  ipiuik  of  it  ngiiiu  Inli'r  on. 

Wilh  regard  In  l)i<-  action  tif  bilv  on  liiU.  tl)*-  following  statemonte  may 
be  innd« ; 

bile  bnti  a  xliglit  wolnrnl  itctioo  mi  fntx,  ns  seen  in  its  use  by  paintera.  It 
bail  by  ittelf  a  ilight  but  only  Flight  HDnlsifying  power:  a  inixiure  of  nil 
and  bile  sppnmK^  after  »hakiiis  rather  leas  rapidlj  liian  a  mixiur*  of  oil  and 
water.  With  fattv  aciili>  Ink  forms  oonps.  It  is,  niorMver.  a  solvent  of  wilid 
RiMijM,  and  it  would  aiijicnr  tlttil  the  emulsion  of  fnts  is  under  certain  cirftuai> 
UMKea  at  nil  events  lacilitJited  by  the  preseooe  of  soapfl  in  solution.  Hvncie 
hil«  ia  probably  of  much  i^realer  »ae  aa  an  emulsion  a£ent  wben  mixrti  nilh 
paiicruilic  juice  tiiitn  wben  acting  by  it«lf  alone.  To  ttiin  pnint  we  sliall 
rcluni.  I.aiitly,  tbe  paiwagc  of  fats  through  ntcmhraiiea  in  asuiMiNl  by  welting 
thi>  mcnibrnueH  Hitli  bile  or  witb  a  solution  of  bile^uilta.  Oil  will  |>aiw  to  a 
certain  extent  thmuxh  a  6llcr'paper  kept  wet  with  a  wiluiion  of  bile-enlu, 
whcreiu  il  will  not  paaaor  pasae^  with  extreme  dilHcuIty  through  one  kept 
oonatantty  nc-t  with  diMilled  water. 

llitc  pijiwwi's  Koiae  autiKKpiii-  ((ualities.  Out  of  the  body  its  proMiioa 
bindera  various  (mtrffai-tive  [iroetai«e« :  and  wli«»  it  ia  prcvenlwl  from  flow- 
ing into  the  alimcnturr  cjuinl,  tht^  coniitnta  of  the  intwtinc  undergo  cbaueee 
diflerenl  from  tbow  wdicb  tnlcc  \>]»w  un<lcr  normal  eondiliona,  and  leading 
to  the  appaanuwe  of  vurioun  prodiictji,  ffiiecially  of  ill-emeltine  gaaea. 

Theae  various  actiotm  of  bil«  tf^m  to  be  i^a^ndenl  on  tbe  hile-solts  and 
not  on  ibe  pigtueiitnry  or  other  Goii»tiluciiu. 

Pauetealie  Juiee. 

^  248.  Natum)  benllliy  pancreatic  juiee  obtained  by  uiettna  of  a  (emt 
pnnrrealic  tiatula  differs  fn>m  tJie  digestive  juiew  of  which  we  bavc  al 
H|H>k<'U  in  tbe  coinjttimtivctv  large  quantity  of  proteids  which  it  cuntaiii 
Il«  i^mip'wition  vanca  at'ctirdiiig  to  the  rat*  of  w>cretion,  for,  with  the  mo 
rapid  flow,  the  increnso  of  lolul  wlid.-i  dm-M  not    kiwp  jincc  with  that  of  the 
wai«r,  though  ibe  ash  rcauiiiDt  rcniurkahly  iiui:>tant. 

Ity  an  inciaiuD  through  the  linen  allui  Ibr  jiancrratic  duct  («r  ducts)  can  easll; 
be  loand  either  in  the  rabbit  or  in  the  ilug.  uod  u  canuln  Hectin-d  in  it  Thate 
no  difficulty  about  a  temporary  llatula:  but  with  permanent  fintuliu  tliv  oocretio. 
ia  apt  la  breomr  allt^rcd  ni  nature,  and  to  lose  many  of  Its  cbaracteriBik  proper 
tJM.  t^nie.  liiiirrcver,  have  mocceaed  in  obtaiaing  pcrmanonl  fistula-  witliotit  an} 
impnirmviit  i-f  llic  secretion. 

H<-althy  |iaui-ret)tio  juice  is  a  clear,  ROnewhat  Tiacid  fluid,  fVothiog  whe 
shaken.     It  hiu  a  very  decided  alkaline  reaction,  end  contains  few  or  ne 
structural  ooustituenla. 

The  avenigD  amount  of  itolids  in  the  pancreatic  juioa  (of  the  dog)  obtaiuedl 
from  n  lemiiorarv  fintuta  la  about  8  «>  10  per  oeot.;  but  in  oven  ihorouglilr^ 
active  juioc  obtaiuwl  from  a  permanent  tUtula  is  not  more  than  al>out  'i  to  ai 


PANCREATIC  JCSCZ. 


3&6 


per  ctai.,  OlfltlMing  inurgmnir  matlor;  and  thi>t  i«  probnbly  the  normitl 
Binount.  TIm  imp»rUii)l  ron«litii«DU  of  quite  frceh  jiiioe  are  ftlbumin,  a 
prciilinr  form  of  prot«)d  allied  to  layoRin.  giving  Hm  U»  ■  sort  of  clottin);;.  ft 
Mimll  nmountof  lnt«  nnd  eaitn#,anrl  ttoomparativelr  large  quantity  of  eodiiim 
<»irb<>niit>?.  to  which  ihe  nlknline  reRcti'>n  of  the  juiw  is  due,  and  which  SMnu 
to  be  peculiarly  associated  ^vilh  the  pro[eid<i. 

Since,  as  we  aImiII  pmenlly  see,  pancrefttic  juice  coDlnins  a  fernient  autin^ 
eni-r^liiitlly  on  proteid  matters  in  nn  alkalioe  niediiini.  it  rapidly  di),'«atH 
its  own  proteid  conelituents,  and,  wlieu  kept,  epeedily  cbau^.'eM  in  character. 
The  luyosin-likc  clot  is  diasoU-ed.  and  the  juice  aoim  contains  a  jteouliar 
form  of  alkali-albumin  (precipiiatable  by  saturation  uritb  inagn«tauin  itui* 
I'hale),  as  well  as  »niall  qiianliliea  of  leucin,  tyroaiu.  and  jxtptonc,  which 
fteem  10  1)«  ihe  ^rMluuIn  ot  Mlf-di^tion  and  are  eiiliroly  alwcnt  from  the 
perfri'dy  fresh  juioe, 

3  248.  Anion  on  food-ttiijfft.  On  slareh  pancrailic  Juice  acts  with  great 
mefgy,  rapidly  converting  it  into  niKar  (chielly  niallonc).  .\ll  Uiat  hna 
been  Naid  in  thb  respect  conoeraing  MUira  nitght  be  rv»oat«d  in  the  i»w^  of 
paucrtatic  juicv,  except  diat  the  aotivtty  of  the  lattt-r  ia  nr  grcuhT  thaii  that 
(if  Uiv  foniier.  Foncreatic  juice  and  ino  aqueou*  inliiaioD  of  the  gland  are 
n1nii»  cupabtc  of  converting  atarch  into  •UEar,  wbcthor  the  animal  front 
which  ihcy  were  lak<:n  bo  utarving  or  well  fwT.  From  the  juice,  or,  by  the 
glyoeriu  nielhixl,  from  tlit-  glniiii  it«clf,  an  amylolytic  rerment  may  be 
■pproximatcly  i]>oliitc«l. 

On  pntei'U  pnncnulic  juice  also  «xcrciM«  n  Bolrctit  action,  so  far  similar 
to  thai  of  )^Cric  juico  that  by  it  proteids  are  ronwrted  into  peptone.  If  a 
frw  flhreds  of  librin  are  thrown  into  a  small  quantity  of  panrrciatic  Juice, 
they  speedily  disapi^ar,  e8i>eciully  at  a  tenipcruture  of  'A't"  C.  niid  the  mix- 
ture is  found  to  contain  peptone.  The  activity  of  the  juice  in  thug  converting 
protetda  into  peptone  is  favored  by  uiOKaae  of  tem]>erature  up  Ui  40°  or 
tbereabouta,  and  hindered  by  low  tmnperalurfe> ;  it  ia  permanently  destroyed 
by  builinjf.  The  digCitive  powers  of  the  juice  in  fact  (te|>end.  like  tboee  of 
j;astric  juice,  on  the  preseooe  of  a  ferment  which,  aa  ne  have  already  add, 
nay  be  isolated  inuvb  in  the  same  way  as  pepnn  is  isolated,  and  to  which 
the  name  tiyfuin  bus  been  given. 

The  apji«arwnce  of  Rbrln  undergoing  pancreatic  digeation  is,  however, 
<)ifl(!!reiit  from  tliut  untlergoing  )>eptie  digestion.  lu  the  former  ciuv  ilie 
fibrin  doca  not  swell  up,  but  remains  as  upaijue  as  before,  and  ap])«sira  ta 
sulfi-r  cornwioii  rathtr  thiui  wilutiim.  But  there  is  a  »till  uiok  imfioriaut 
di»(iiicti«n  lictwiH-n  [iniii'n-ittic  Bn<l  jH^ptic  dig<qciun  of  protcido.  Peptic 
dwasiioa  ic  etevnliiilly  un  acid  ilig<»ti<jii ;  w<'  have  seen  that  the  action  only 
lute  pUce  in  lli<-  pn^scncc  of  an  iK'id.  anc)  t*  armt«d  bv  neutral ixntinn. 
Pnncr«atic  digmtion.  on  the  otitvr  hand,  may  Ih-  regarded  iw  an  alkaline 
digcstioo  ;  the  action  is  most  energetic  when  somi'  alkali  i*  pnmnt,  ami  tlie 
activity  of  an  alkalioe  juice  i*  himleml  or  delayed  br  nciiimlizntion  and 
arrerted  by  acidilication  al  lost  with  mincntl  acids.  The  glytwrin  extract 
of  paDci«»B  18  under  all  cirriimatancaa  m  inert  in  the  presence  of  free  mineml 
acid  as  that  of  the  stomucb  in  the  preseooe  of  alkalies.  If  the  digestive 
iniKtur«  be  supplied  with  sodium  carbouale  t»  tbu  extent  of  1  per  cent., 
digestion  proceeds  rapidly,  jiitl  ns  does  a  peptic  mixture  when  acJdulatod 
with  hydntchlurlo  acid  to  the  extent  of  U.'i  per  cent.  Sodium  carbonate  of 
1  jier  cent.  Meois  in  fact  to  play  in  try-ptic  aigeetion  a  jnut  altogether  ci^ni- 
parable  to  that  of  hydrochloric  acid  of  O.'i  per  cent,  in  gastric  digestion. 
And  just  as  pejisin  la  rapidly  destroyed  by  being  heated  to  about  40^  with 
•  1  per  c«nt.  Kilution  of  sodium  carbonate,  ao  irvfisin  is  rapidiT  deatroyed 
by  beiag  similarly  heated  with  dilute  hydrocliloric  acid  of  0.2  per  oenL 


;jr.4 


■in  K    Tl.'i.'rh- 


oiiit<'ul>'  I't'  tilt-  stmiiiK'li  ; 
M'c,  sii  jiri'iMinw  ilif  "uv  t 
iii'tiiiti  il  is  'listiij<-tly  iitti! 
I)ili^  ri'iiilfr^  jni^irii'  jiii'i- 

HilulillU    fll'   Ilill'->!lll-.   i^^    ;i'. 

■ll;;i'Sti<iii.  !i  |)rt.'(;ijiil!it*'  Ink 
|H>|)t<ini-,  [K'liHiii.  iiri<i  liili: .-. 
of  liili'  <)!'  itiiluliiiii  lit'  III!- 
iiuTt   tdwniil  i)nilvi'l^.     T 
■  liKHii-niini,  and  v.-  .-hull  -, 

Willi  rcgttrii  tn  i]f  -.f 
Iw  ttiuili:: 

Itilc  Uai^  a  AiiiUt  >"\\-  ■ 
liiii>  liy  il»t;ll'  II  sli;.')ii    In- 
itiiil  liili'  Kf|)iiri(tc  :ilii  r  -:  . 
wiitLT.     Willi  tliily  il.  i  ! 
(Hiiijii',  unci  it  H'iidM  ai'i' 
staiut-w  nl  III!  L-vi-m-  !;■ 
Iiilc  i.i  jiniluilily  nl'  in  •■'■ 
Iiuiicn-iilif  jiii''i:   lh;i' 
rc'Uirii.     l-iL-lly.ilii-  !■.■ 
tilt!  nll^nli^rH^)^.•s  will    ■ 
(.■ertiiiii  ext*"!  ilin 

wlieri-iiM  it  will  

nuiintiiiitly  wfl  «il' 

Jlili^   ixissi^iw-  - 
liinik'iv  vurioii-"  |' 
ill}:  into  the  tiliin'  ' 
(lillbri'iit  I'nmi  ili' 
to  tliL'  a|>[ieiirnin'' 

TIh'^i'  vari<iii>  ■ 
nut  on  tliu  [>ig'ii' 


!;  248.  Niil>i' 
imiKTi'iiiit'  tii'i'- 
K|Hiken  in  lli' 
ItM  iiiiiijHwitii" 
ru|iiii  11"W,  ill' 

WUtlT,  tlKlllfjIi    ■ 

liy  uii  i«i'ii-i 
!>(■  fiiuml  i'ill" 
iKxlillii'iiliy  -I 
is  iijii  tnlii'i'"i 
tiw.  Siiiiii--  '■ 
iiii|>uirmi'iiv  >■ 

Hi-altliy  1' 
alrnkt'ii.     It 
8tnictural  »■■ 

The  hvit: 
t'n)m  a  tcini 
uctive  jiiiiv 


;i*    •' 

I    : 

iji  I. 

iif  ; 


.  ■!■_-   liiviirnblc 
-'■■i;--ril,  lliiTi-  'a- 

•■     llillll     I'il-Cri 

L     ■oiwi'i.-n  [i;iM- 

:-.':>iii'  "iiL'-'rlii'ii 

.    .:-:ii1>iiniin.  Iml. 

i/Kuli-:»lliviiiiin. 

-    riliriti  Ix ruvs 

-.     ]  ;tik:ili-!ili>iiiMin 
■  i.  liliriii  ir  Hi'U'd 

-      ■  Ti;ll  [iliiillli't>. 
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t>  carried  on  io  llie  |>reseucie  of  aalicylio  acid  or  thj'mol,  irbiok  prevent  the 
dffV«lupciHnt  of  bBAteria  tind  like  or){&niani  but  permit  the  aclion  of  tha 
trvnmln.  no  odor  is  peroeiveil  ami  nu  indol  h  produced. 

-I'uT  loiiKK^ontiiiiitid  digMiitii).  especially  when  accompanied  by  putre- 
'  "  ')i.-4^>impoHiiicii),  ihe  amoutit  of  pn>tei<u  which  are  oarried  b«y«iii<l  tho 
I  '^ge  and  bri>l«ii  up  may  be  very  Krvat. 

:no  digmUon  such  a  profnuDd  di-»inicti»n  of  protcid  material  ocoiint 
Lii  a  inDcli  tft«i  extt'nt  »r  not  at  all ;  noilhor  Inudii  nor  lynwii  can  Hi  pnxent 
b**  ninttiilcryxl  nn  nuttiral  product.-'  of  tlic  acti'Xi  <>f  pepsin. 

On  tht^  eelntiDiferoiin  ulemenU  of  the  liwun  u*  lh«y  actually  t'xiitC  in  the 
tiiviK  pr«'rioii8  to  aiiT  irwiinieni,  pnncmttic  juice  nppoira  to  have  no  «iilvonl 
aciroii.  The  fibrillir  am!  biitiillcs  of  librillR  of  ordiiiarj-  nnlouchcil  con- 
niirtivo  tiMiio  arc  not  digntlcd  by  pancreatic  juico,  vrhich  in  this  respect 
airor<li>  n  ulriklng  rontraMt  to  gn«tric  juic«.  But  when  lh«y  hare  been  pre- 
vio«i»ly  trait«'l  with  acid  or  boiled,  so  w>  to  become  canvcrt«d  into  actual 
eelatin.  try|win  i«  able  to  dissolve  thero,  apparently  chauf^og  them  much  in 
Ine  Mirae  way  as  does  pepsin.  Trypsin,  unlike  pepsin,  nil!  dissolve  mucin. 
Like  pepsin,  it  is  inert  toward  niicleiii,  horny  tiasuce,  and  the  sn^wlled 
amyloid  malCer. 

)  >n  j'tlt  pancreatic  juice  has  a  twofold  action.  In  the  Grsl  place  it  emul- 
aiti««  fats.  If  ho^'s  lard  be  gently  heated  until  it  melts  and  be  then  mixed 
with  |>ancrealic  juice  before  it  solidiliea  on  cootiDK,  a  creamy  emulsion  taating 
for  almoat  an  indefinite  time  is  formed.  80  also  when  olive  oil  is  shaken  up 
with  jiaucreatic  juice,  (be  separation  of  the  two  tluids  takat  place  very  slowly, 
and  a  drop  of  the  mixture  under  the  microacope  allows  that  the  division  of 
the  fat  is  verr  minute.  Au  alkalinti  aqueous  infusion  of  tho  gland  hiwi 
similar  emulaitying  jiowcm.  lu  thf  w^iond  place  pancreatic  juice  splits  up 
iMUtral  fata  Into  iht^ir  n-«[H-cMivi-  nciiln  and  Klyceri"-  Thus,  f>almitin  (or 
tn|ialmitin)(C,H„.('0.0),.C,H,iawith  the  aMumption  of  :{H,0 nplit  up  into 
thru!  RiolecuU*  of  palmitic  acJd  H  (CnH^.CO.OH)  and  one  of  iilyovrin 
(C,H,)  iOH,l ;  anil  wt  with  tho  other  neutral  fill*.  If  |K'rfoctly  iti-iitral  t'al 
be  trattwl  with  pancroutic  juice,  cvpcfially  at  (be  bodv-tvm|M;rature,  tho 
emulsion  which  i«  formed  Kpcnlity  (akei*  on  au  add  reaction,  mid  by  sppro- 
pfiate  means  not  only  the  corresponding  fatty  acid»,  but  glycerin  may  bo 
ob(uited  from  the  mixture  When  alkan  is  present,  the  fatty  acids  thua  set 
free  form  their  corresponding  soaps.  Paiicrmtic  juice  contains  fat«  and  is 
conser^uently  apt  after  collwtion  (o  have  lis  alkuliDily  reduced,  nod  an 
atiieous  infusion  of  a  pancreatic  gland  1  which  always  contains  a  consid- 
erable amount  of  fat)  very  speedily  becomes  acid. 

Thus  iwncreAtio  juice  is  remarkable  for  the  power  it  poesessee  of  ac4iDg  00 
all  tlie  fuod-etuflfc,  on  starch,  fats,  and  proteids. 

The  action  on  March,  the  action  ou  proteids,  and  the  splitting  up  of  neutral 
fats  appear  to  be  due  to  tl>e  presence  of  tliree  disliuct  lerments,  and  nwihode 
have  wea  auggeeted  for  isolaliog  ihein.  The  eniulaifVing  power,  on  the  other 
hand,  is  counec[ed  with  tbegeoeral  oompoeitJonof  the  juice  (orof  the  ac)ueou» 
inl\i«ion  of  the  gland),  being  probably  in  large  measure  dependent  on  the 
alkali  and  the  alkali-albumin  present.  The  protemlyiic  ferment,  trypnii,  aa 
onlinarily  prepared  iMiina  to  be  proteid  in  nature  an<)  capable  of  giving  riaa 
by  digt«ti<Mi  to  pept'>iie ;  but  it  may  he  doubtetl,  as  in  the  uaso  of  porwin  and 
other  fi'rnMtntx,  whcttxT  the  purv  (ormetit  haa  yet  1)een  iwilattd.  Then-  an: 
no  mMuiH  of  dii>tiiigiiiHhing  the  amylolytic  ferm«nt  of  the  pitncrenn  frifin 
(ityalin.  Tlw  term  paHirrrittin  hiia  lieeii  variouslv  ep|)lied  to  iiimiy  ditlemnt 
pnparationN  from  tho  gland,  and  ita  use  had,  p«rna[w,  I>ett4:r  Ih-  avoided. 

The  action  of  pancniatio  juice  or  of  the  inluiion  or  uxiruct  nf  the  inland, 
on  starch,  is  seen  under  all  vircumataiiem.  whctlier  tho  animal  Ik-  fa«ting  or 


< 


us 


THE    TIS81 


iSU    MKCHAS 


gbiid  WM  eonliued  to  tlie  Utsk  of  letting  certuiu  coiutiiuenu  of  ilif  hluud 
pan  from  the  ciipilturieB  liurruuiidiug  the  iilreolus  tliri>U|{li  the  c«lls  to  ih« 
channel*  of  ihe  ducts,  while  refusing  a  paisui^  to  iitht^ra.  We  uomr  know 
thkt  ceri&in  ini))ortunt  iiuialitucnld  of  each  jnu-c,  thi-  peiMin  uf  KUtric  juice, 
Ow  mucin  of  salivn  iiml  the  like  nre  r<iniierl  in  the  cell,  uiil  not  ohuined 
Tandy  made  from  llie  hlood.  A  minute  (lunniiiy  of  )ie[>«i»  does  exUt  it  b 
true  in  the  hlond,  hut  there  iiiv  reaunn*  fur  thiukintc  thiil  this  bu  tnnde  it« 
Wny  back  iiilu  the  hlom],  viiher  heiiig  a1)sorbiril  from  the  intvrior  of  tie 
etoinnoh  or,  an  teem*  more  prohuhlc.  picked  up  directly  from  the  (tastno 
gluids;  and  ito  with  some  nf  ihc  iithi-r  I'oustitiientK  of  other  juices.  The 
chief  or  Apevilic  consljtuent*  of  <-nt.'h  juice  nra  fomieil  in  the  oell  itself. 

Btit  the  juice  vccrv-lcil  hv  any  gland  conKi»l«  not  only  of  lhe»pecilio  tub- 
Mooee*  audi  ■«  mndn,  [>cp»in.  or  other  ferment,  or  other  boiIi««,  fouod  in  it 
■lone,  but  aha  of  n  largi^  iiunntity  of  miter,  and  of  variou*  other  tab- 
stances,  diietly  »iilint'»,  common  to  it,  to  other  juic«  and  to  the  blood.  Aim) 
the  <jue^iim  ari*iT»,  Is  iho  water,  nre  tltc  Milt*  and  other  comiiion  BubitKDce* 
furnished  bv  llie  wime  att  at  that  vihidi  supplies  the  spmlic  conttiluenta T 

Certain  faafM  »ug)nMt  that  they  are  not.  For  ioiiancc.  a«  mentioned  wirat 
lime  &gi),  in  the  submaxillnn-  gland  of  the  doe,  etiraiilatian  of  the  choirla 
lympuni  produce*  n  copious  How  of  saliva,  nbicn  is  iisunlly  thin  and  litaptd, 
while  ntimulatiou  of  the  cervical  synipnthelic  produoes  a  scanty  flow  of  thick 
viscid  wliva.  That  is  to  say,  stimulation  of  the  chorda  has  n  marked  effitot 
in  promoting  the  dischari^e  of  nater,  while  stimulation  of  the  syiu{iathatic 
kaa  a  ninrkcd  efleet  in  promoting  the  di»charf^  of  mueio.  To  this  ire  may 
add  the  case  of  the  parotid  of  the  dug.  In  this  gland  aiimulation  of  a 
cerebrospinal  nerve,  the  au  He  ulo -temporal,  prodiieee  a  copious  flow  of  limpid 
saliva,  while  stimulation  of  the  ^ruiiutlbolic  producM  itaell'  little  or  no  secre- 
tion at  all;  but  when  the  aympatlietic  and  the  cerebro-tninal  nerves  are 
MtimulaCed  at  the  name  time,  the  nuliva  whieh  flowi  iti  much  ridier  in  aoliil 
and  eepcciatly  in  organic  matter  than  when  the  cerebro-Mpinal  nerve  i* stimu- 
lated alone.  And  vt-  have  atreadr  -leeti  thai  in  thtx  gland  the  niicroeoopic 
chauj^  fiilliining  upon  nympitlhetie  i<timulntion  are  more  von.-<picuous  than 
(hose  wliich  follow  uimn  cercbronpiiial  ttiiaulation. 

The«e  and  oilier  facl^  have  led  to  the  conception  that  the  act  of  secrettoii 
conugta  of  two  purt«.  uhich  in  ono  ease  may  coincide,  in  atnnher  msy  take 
place  apart  or  in  diHercnl  proportions.  On  the  one  hand,  there  is  the  dis- 
charge of  water  carrying'  with  it  eoninion  solubkt  snhetAnu«Si  chiefly  «idinee, 
derived  from  the  blood  ;  on  the  other  liimd.  a  metabolic  activity  of  the  (vll- 
subitauce  gives  rise  to  the  specific  constituents  of  the  juice.  To  put  the 
matter  broikdiy,  the  latter  pioccs  produces  the  specific  eoiutitueuts,  the 
former  washes  these  and  other  matters  into  the  duct.  It  baa  been  further 
auppofcd  that  two  kinds  of  nerve  fibres  exist:  one  governing  (he  former 
ptocm  and,  in  the  cose  of  the  aubmasillary  gland  fur  instance,  prepun- 
aenting,  though  nut  to  the  total  exclusion  of  the  other  kind,  in  the  chorda 
tymjuaiii ;  the  other  governing  the  latter  pn>oea9  and  preponderating  in  the 
branches  of  the  cervical  sympathetic,  liicse  have  been  called  reapeclivelr 
" secretory  "  and  "trophic"  flhre^:  hut  these  terms  are  not  desirable.  It 
Biajr  be  here  remarked  that  even  the  furnier  proceai  is  a  distinct  activity  uf 
the  gland,  and  not  a  mem  infiltration.  For.  iw  we  have  seen  in  the  cane  of 
the  salivary  jflamU,  when  tit.ropiue  it  given,  not  irnly  do  the  npuuJGe  cousdlu- 
enis  ceose  to  hi-  ■•jecleil  lu  a  conM-iiucnce  uf  utimulntion  of  the  chonl.i,  hut 
the  diiicliarge  nf  iraler,  in  spite  uf  the  hliiudvivnelx  liecumin;;  dilnt^il,  i»  also 
iu-r«>ted  :  no  siiliva  at  all  leaves  the  gland.  And  what  is  tnie  of  the  salivary 
viands  as  regnnls  the  dc|K'ndene4-  of  the  flow  of  water  on  something  eMi 
beside*  i1h!  mere  pivMiiTe>  of  the  bhiml  in  the  hloodviMseU,  npixtar*  to  hold 


iijiseslisl 
wuier  n  ilup  lo  nn  iictivily  of  ihc  cell  :  llif  hviMttI 
pot  forwaH  iliai  rliiinKn  iu  ilie  cell  give  ri»e  lo  (lie  ft-ntiatioD  in  Ui«  cell  of 
■qfalUmwa  which  alworb  nnler  from   ilie  blood  vr  Irniiih  on  the  one  >id« 
«ed  fpvt  it  up  on  ib«  other  aide  tuto  ilie  lumen  of  ilie  itlveolua.     Bucb  an 
bjpolbeua  csnout  be  regarded  as  tirave<) :  but  ihe  mere  putting  it  fnrward 
T«bn  doubt*  as  to  iliv  validity  of  tlie  diatiuction  on  which  we  have  been 
■)««llta8;  and  niher  cviuidenitioiis  point  in  the  Mme  direction.     For  in- 
•uiKV,  if  Ihe  ntnimon  aoluble  mUh  pievent  in  a  Juice,  as  diatinguishcd  lW>m 
tbe  •(■ecilic  «iii*>iiiueii(»,  were  merely  cnrried  into  the  juice  by  the  rush,  m> 
u>  tfrak.  nf  water,  we  •huuld  ospe<-[  lo  timl  the  |ierc-enin^'e  of  tbei»e  aolta 
eilhrr  rrmaiDiiig  the  Mtntc  or  |M:rhap«  decre&Klng  when  Ihe  juice  wila  cccreted 
atun  mpiilly  and  in  fnlkr  volume.     Bui  under  these  circuniMtnuci'"  the  i)er- 
rmtap  very  frcjucnlly  )n<'re>i9n>:  luid  In  general  we  find  thiil  under  vnnou!! 
drruBiftaan*   tbo   pro]i»rtiun  of  wits  tecreieil    tn    llitt   rpinntity  of  wnter 
•rmtnl  may  vary  «iu»*ieT»bly.     Obviously,   whik-   something  delcrmines 
tb«  quantity  of  vnter  pacing  inio  ihe  uIvcoKib,  soniething  rise  livtfrminrs 
boo  much  of  coniRKin  MiltibU-  wiIIa  Ihnl  wuIit  ciiiilaiiii>,  snd  i>till  KinielJiing 
aJaa  rietcnninvs  to  Khst  extent  Ihnt  wnicr  i;i  rdso  hulen  with  ■pccific  conifiiiu- 
rat*  and   oth«r  organic  bodiro.     The  whole  iiclion  is  loo  compliciited  to  be 
dracrilird  as  coiwisttng  merely  of  the  two  procesMV  mentiimcl  aliove,  but  the 
liaM  has  not  r«t  come  lor  clear  and  definite  statemenlf^.     Everything,  boir- 
snrer,  teii(b>  to  ebow  that   the  cell  is  lb«  prime  agent  in  the  whole  business,      _ 
though  we  cannot  at  prM«nt  ddioc  the  natnro  of  th«  H-vpral  changes  in  tbo     ■ 
cdl,  iNr  can  we  sav  how  thuse  changvo  arc  exactly  related  to  each  other,  to     " 
rhangin  of  ibe   bfood-pmEHre   in    the   bloodvessels,   or,   we    mar    odd,  lo 
thuugm  taking  place  in  the  Irmph-spaces  which  lie  between  thetilood  and     ■ 
the  «elL  I 

We  may  perhaps  add  that,  uuce  ia  certain  cutaneous  secretiof;  (''■'■tils  the 
alreolus,  or  what  ci>rr«t>|H>nt}H  to  tlie  alveolus,  is  nramied  round  with  plain 
musniUr  fibres,  the  contraction  of  which  upt>ear9  to  force  the  secreiinti  out- 
ward, the  idea  bas  ticen  miggeetetl  that  in  gluuds,  such  as  we  are  now  voti- 
ddning,  the  ctJl-subsianee  niakitig  ii>e  of  "protoplasmic "  coDimctiou  tn- 
M«ad  of  aetna)  muscular  ci>iilraciion,  may  force  part  of  the  c«II  contents 
into  the  lumf'n  nf  the  alvooluH.  Such  »  mode  uf  seorctloD  would  be  I'om- 
Mrable  tx  the  ejirtionof  undiKCvtcd  malcrial,  or  "excretion,"  by  an  nni«ba. 
ilut  we  hove  no  MitUl'nclori'  vvtdrnce  in  favor  of  ihi*  view. 

I  WO.  Thnmghoiii  the  above  wc  hnvc  spoken  as  if  the  secretkm  were  fui^ 
nislted  McluHVely  by  the  cells  of  the  alveoli  or  stKircting  portion  of  the 

C'  D«l,  Bsiftbo  cpiihcliura  cells  lining  ihe  ducts,  or  conducting  portion  of 
flaad  conlribdtpd  nothing  lo  the  act.  In  the  gastric  ghinds  the  slender 
cells  Itniog  t)>e  moulhs  of  the  glands  (which  comspond  to  ducts)  and  cover- 
iw  ibe  riages  between,  are  mucous  cells  secreling  into  the  stomach  gener- 
ally a  Btnsll,  but  under  abnormal  conditions  a  large  amount,  of  mucus. 
Nbicb  has  its  uses  but  b  not  an  essential  part  of  the  gadric  juicu.  In  Ihe 
salivarT  {.dandit  we  ean  hardly  suppose  that  the  lone  stretch  of  character- 
istic ruluinnar  ejiithetium  which  reaches  from  ibc  nU~eoIi  to  the  mouth  of 
tiM  ioag  main  duct  wrves  simply  to  furnish  a  smooth  lining  to  the  conduct- 
iag  I  WSj^i s  .  bnt  we  have  as  yet  no  clear  iodication«  of  what  the  function 
of  ibb  epitbellum  e»a  be. 

I  ML  Before  we  leave  the  niechanisin  of  secretion  there  arc  one  or  more 
acvaaory  noinia  which  deserve  atleiition. 

In  tniitiiig  ju*t  DOW  of  (he  gastric  elands  we  spoke  as  if  pepsin  were  the 
only  ImporloDt  couliluent  of  ^iric  juice,  wbenaa,  as  wc  have  previously 
,  the  acid  is  e(|uat[y  casenlial.     The  formaltoa  of  the  free  add  of  the 


I 
I 

1 


I 


85(r 


THE    TI»St'EA    A.VI>    MECHANISMS    OK    l>IOKSTtON, 


KMiric  jiiico  is  vtry  olMcurc,  nud  maiir  ingenious  but  tiRMtufKclorir  v'ltvti 
n*v«  liM-ti  [xit  f'lrwiiril  ti>  cxptitiii  it.  Ii  tvum*  uutiirul  f  >  •ujiihml-  ilint  it 
siriscc  ill  M^ino  nuT  frum  the  liecompOBiliou  of  fiJiiim  chloride  dntwn  fn^ia 
ibi.-  IiIoihI  :  tind  this  is  8U|>purt«d  by  the  fact  thsit  whcti  the  eecr«livn  •*)'  jn*- 
tric  jiiico  is  iictivoly  going  on,  the  nmotiiU  nf  cliiondm  lenviog  llie  l>loud 
by  ttw;  kidney  it  proporiioniklcly  dimiiiLghod ;  hut  nothing  de6nit«  cui  nt 
ptTOHUt  lie  elated  as  to  ihe  ntechnnisiii  oJ'  ihnt  deeoni position.  And  even 
ndlDiKin^  thiil  llie  sodium  chloride  of  the  body  at  large  is  the  utlinistf 
anuixMi  of  ihe  chlorine  element  of  the  ncid,  it  appears  wore  likely  that  thai 
elemenl  &liould  be  set  free  in  the  stomueU  by  the  deoom position  of  aonie 
highly  coiu|>les  und  unstable  ehloriiie  compound  previously  eeoerated.  Ibon 
that  it  ahould  arise  by  tlie  direct  tiplitiiu^'-up  of  eu  stable  a  body  a^  Miliun 
chloride  at  the  very  time  when  the  ncld  id  secreted. 

lu  the  iriiii,  while  ])e|isiii  true  from  acid  in  secn-te^l  by  the  glaud*  in  the 
lower  iMtriiun  of  the  (t.^>[ihii);uii.  an  acid  juice  it  utTorded  by  ijlaudn  in  the 
ittouacli  itself,  which  have  accord iu;i:ly  been  culled  ujrifiifi'r  (iiit-nr  lo  *hur]>co, 
acidulate)  glaudn;  (nit  thrau  oxyntic  ghinthi  Hp^war  nlgo  to  wcMte  [K-jKan. 
In  the  inanimal  the  Uolnliil  pylorus  secretes  an  nikniine  juice;  in  tnct,  lb* 
nppi-araiiee  (>f  un  acid  juice  is  limited  lu  tho^e  ]>oniuii»  of  the  itomMih  in 
nhich  the  gluuds  oonluin  boUi  "  chief"  or  "  centrni,"  nud  "  ovuid  "  or  "  bi)r> 
der"  cell*.  Now.  from  what  has  been  previously  wiil.  there  caii  be  do 
doubt  thiit  the  chiuf  cells  do  wri-rcte  i>w|i«iii.  On  ifie  other  hand  lhen>  is  no 
flvideoce  wliatevir  of  the  formation  of  i>e|»in  by  the  '-  border  "  or  "ovoid  " 
cells,  though  thi»  wns  once  supposed  lo  no  the  cose,  and  these  oelU  nere  un- 
fortunately formerly  culled  "  peptic  "  cells.  Hriice  it  hns  been  inferred  that 
the  border  cells  secrete  neid  ;  but  the  argument  is  at  present  one  of  exclu- 
sion only,  there  being  no  direct  proof  that  these  cells  actually  niauulacture 
the  acid. 

The  reuuiu  apiieais  to  he  fonuetl  by  the  same  cells  ivhtch  maiiuradnrc  the 
pejwn,  that  is.  by  the  chief  celU  of  the  fundus  geiiertUly,  and  to  totuv  os- 
tent  by  the  cellti  of  the  pyloric  ^lauds.  We  may  add  that  we  have  cvidencv 
of  the  cxistenvc  of  a  xjidc^u  of  renniu  analogouti  to  the  cyniogen  of  pepsio 
or  of  trypsin. 

The  mueu»  which  it  prevent  ns  a  thlii  layer  over  the  surface  of  the  fasting- 
(toiuach,  aud  which  miH^'lally  in  hcrhivciriiu:t  animals,  is  iocreoMid  during 
digwtioti,  comes.  iu>  vr  hare  «aid,  fmui  the  mneous  cells  which  line  the 
mo(ith:<  of  the  si'vcrni  Kb'udi  and  cover  the  iuterveniug  surfaces. 

$  S43.  We  pr«vioii»fy  cnlleil  iitlenliun  t"  the  fact  that  in  the  case  of  the 
stoinnch  the  al»iiqitioii  of  the  )mNtu[.'t.->  of  digestion  largely  iucnasod  the 
activity  of  the  secreting  cells.  This  lins  led  to  the  idea  tliat  one  efleci  of 
food  is  to  "charge"  thegootric  evils  with  |>e|isin[igon,  and  that  certain  article 
■>r  fend  might  In-  considered  as  es]>cciidly  pcptosenoite,  i.e.,  conducive  to  the 
formation  of  pcjisin.  8uch  a  view  is  tempting,  out  oeedfl  u  yet  to  be  mom 
fully  snpjiorted  by  facts. 

S  843i.  Sc«in;;  the  great  solvent  |>om>r  of  both  gastric  and  pancreatic  juini. 
the  queetion  h  ualurally  suggctited.  Why  dom  not  the  stomach  digest  itiKilfy 
After  death,  the  stomach  is  freipiently  found  partly  digested,  viz..  in  cases 
wben  death  has  taken  place  suddenly  on  g  full  stomach.  In  au  ordinnrr 
death,  the  membrane  ceases  to  socreie  before  the  circulaiioa  U  at  an  end. 
Timt  there  U  no  inncciul  virtue  in  living  ihiaKs  uliich  prevenia  their  being 
diMsted  ix  shown  uy  the  laet  that  the  leg  of  a  living  frog  or  the  ear  of 
n  living  nihhit  introduced  into  the  stomach  of  a  di*;;.  thr^mzh  a  gastric 
tbtula,  is  rvadilr  di){usted.  It  has  been  »U{U!eate<l  that  the  blc»>d-<-urreut 
keep*  up  an  alkalinity  »uffictent  lo  iieulndiAe  the  acidity  of  the  juice 
in  the  region  of  the  glnuiU  themwlv<i' ;  but  thid  will  not  explain  why  tlw     j 


A 


BILE. 


691 


fOcmilc  jnico,  which  !*  netivr  In  nn  nlkiiline  mcclliim,  don  unt  dt|fc»t  iho 

f«Mnli  uf  tho   (Kiucrm*   ilH'If,  or  why  ihc  diiitw'.ivt'  cwll*  of  lhi>  IiIuimIIi-m 

MfiDMOon  or  hy<lni»<oii  il<>  iiol  iligwl  ihfiii--"'lv<«.     \Vv  mi^hi  mlil,  it  diwn 

Mt  ripiMn  «hy  lli<-  iinid'hii.  whik  <liiwilviiie  iho  ]>r»tc>iilH*iii  or  th<.-  Kwnl- 

l-tnl  ilintDin.  Jx*  mil  ilinwiK-i-  il»  oiru  ]>n>t»{>lsKin.     Wt  <-itnih>:  nii«w<T  ihi" 

yxttiiM  at  nil  aL  ]>ri-*<-iil.  niiv  nuitv  than  tbi.-  piiniiliir  oiir,  mhy  the  ilclicitlo 

fflAaplaamnribv  niiKiOin  rifUUiluriiit;  lilb  thortilnirK^^  iiili>  ilaclf  l>y  immiwit 

Umm  WBtvr  than  it  rit|iiirM  lu  nrry  on  ile  work,  whik  a  iVu  luomi-iile 

idtr  It  bdeiiil  water  vnlvn  freciv  by  oNinxiK.  bikI  thcolTccUot'ihitt  ruiraiico 

taCMM  abuiutatiflv  vvidcut  by  lli«  fomutiou  iif  biiltn  nitd  tliv  brankitig  ii)t 

0t  iW  |iru<u[iUsnL 

TbK    PaOFRKTia  AXO  Cba RAtTKKg   »»'    UlLK,  PaXL-RCATR'   JUICS  A9IO 

I  M4.  Id  the  liviiij;  btHly  llie  food.  Hibjectei)  to  the  Bction  rirat  of  ibe 
mJIvh  niul  ih«u  nf  tlie  ^iric  juic«.  undergoes  ia  lh«  Muiiiach  ehanK«d  which 
•«  •hall  [m»etitly  onDSKlcr  in  deinil.  and  th«  food  so  rlinngcd  »  paeaed  no 
into  ibv  wndl  ini«»tlDp,  w)i«rv  it  in  further  iubjc<eteil  lo  Ibe  action  of  the  hi)« 
MctMod  by  tht  liver,  of  |i«ni;n.-atti-  juic«  i^«crcti.-d  by  the  ]>auereB!i,  nml  |iib- 
aibly  b>  •otne  «stenL,  tl^ouuh  thi*  by  ao  nieoiia  cvrtaiu,  nf  n  juin^  wcreuil  by 
tb»  laicatiTH'  ilicllt  mtd  mlh'd  mccu*  enUrirut.  It  will  be  c<>iiveiii«iit  to  (ttidy 
tb«  Miliut*.-  utriK-inrc  of  ihr  livor  in  ixiniie<-ti»ii  with  oth«r  functloD*  of  the 
lir«r  omrv  imporlanl.  {irrhii|u,  ihini  that  nf  ih«  Mcrction  of  bile,  rinmely. 
tb*  femuUiau  of  Klyoi'e*^".  i*"d  itlhiT  nu-tabnlic  «vait«  oecurriiig  in  the 
b^Mrtir  C«ll«:  ««  nave  iilrvitdy  •(u<li<r<l  the  vtnicturD  uf  the  {intKTCiw;  and 
llwMrtlcUiraof  th«  inlwiinr  will  \w*t  bi^  4-unridetvd  by  ii#i-)<.     We,  ther(» 

Lfbn,  turn  al  once  to  the  pn>[>cftivs  aitd  chnrnciere  nf  the  nltowiinmcd  jiii«ci. 


I 


I 


hilt. 


,Tbuu^fa  bile,  after  Mcretioti  in  ihe  Ivbulea  vt  the  Ii\'«r,  in  inuved  od  »loag 

IwfMtic  duel.  It  ik  In  the  cnnc  i>f  iu<i»t  aiitniiiU  tiirt  poured  at  uncc  into 

lb*  (Itwlenuiu  but   liikcn   by  ihe  cv»tie  duel  to  the  ruwi^'oir  uf  tliv  gnll- 

bbwider.     Ilrre  it  rt-inaiiiK.  until  tiicli  lime  lu  il  ii  i>ecd«d,  irhen  a  ({liKntiLy 

M  I  '  irig  ihi'  r>iniriii><i  bile  duet  Into  tlie  inusiine. 

1  .  '  iiy  i)f  bib-  vnrii?  tiiiich.  ivii  only  In  diHt-ronl  iiniiimls,  but  In  %ht 

Mmc  animal  nl  diDl'nnl  time*.  It  i-  ni>it»i)vi-r  alferled  by  ihe  tcn|>th  of  the 
Mij-tum  in  the  gnllbtii'Mer:  bik  liikvn  direct  fotni  tin- hepittic  duet.  n(w> 
rially  wliro  KCi-retrd  rapidly,  omlitiii*  little  or  no  miicun:  ihnt  inl>t>D  IVom 
ihe  ^nll  Madder,  na  of  »Iaughtere<l  oxen  ur  ahe«p,  i«  loaded  irilh  mucus. 
Tlie  eolof  nf  the  bile  of  camivoroiii'  nod  oRiuivorous  noiniak.  and  of  nuiii, 
U  jrrnorally  n  bright  gidden  rvl  \  of  herbivorous  animals,  a  yellowi-ih  grc«n, 
or  a  brii:bl  griTii,  or  a  diriy  green,  accortling  tn  eircnmslancc*,  beiiij;  inueli 
nxidifird  by  rclenliun  in  the  gall  bla<Id«r.  The  rmi-linii  in  nouirdi  or  alkaliur. 
Tbe  full(iirii)i[  itinv  Im  taken  as  llie  average  coiii|u)«iliijn  of  buniaii  bile  takflO 

C!  ^it-blailder.  and  thefire  c.iniaiiiing  much  more  iniiciu  m  well  ta, 
y  to  iIh-  N.dids,  in<in>  water  ihaii  bile  frixn  ihe  Wpaiii.'  duel. 
)u  vm  lanr. 
*r  .  ...  «.W,2 

Ida: 
llc^lt.  ...         m.-i 

U^ftc      .  .  .  !>.J 

bidMlMln  .  .  .2.6 

ueiit  and  Piicmiiit  SIM 

•nrpulc  Soil*  7J* 


IMS 


852        TBK    TISSVE9    AND    MKCaANI3HS   Of    OIOKSTIOK. 


The  ODLire  absence  of  proteida  is  a  inarkei]  feature  of  biie;  {WDirreatie 
juice,  as  we  eball  see.  cimttLins  a  conuderable  tjuantity,  aaliva,  ii»  we  liave 
seen,  n  eniol)  quaiitity,  normal  ftniitric  jtiit-e  probablir  still  Ivm  mm)  bile  unoe 
Kt  ail.  Kveii  tbe  bile  wlilcb  bas  been  retaiiicsl  «onie  liiii«  tn  tho  gall-blnd<kr, 
thoiif^b  ncli  in  mucus,  ctniiaiu-t  uu  [>riitri(l». 

The  ciiuetitueuu  wliicb  toriu,  ttjmrt  iVom  tbe  tmicuM,  tbc  fircntbulk  of  ibc 
Di>li<l»  of  bile,  iiud  which  ileitcrve  I'liicf  utlcntioii,  are  iht  pigmenlf  ukI  tli« 
liilc'Kulldl  of  ihue  we  tiball  *)irnk  i mm<'i]inlv]3'. 

Wilb  regard  lo  tbe  liiiir^iiic  mill*  imuully  prwwiil  ii#  nuch  wnlium  »nlt» 
are  confpicuoiis,  aotlium  chlfiridi?  anitiiintiii(;  to  V.'i  or  more  pt-r  cent.,  foilium 
pbocpbale  to  iienrly  nw  nuicb.  (lie  nt\  being  cnrlhy  ph<wphalti(  ami  other 
mnlters  in  small  i|oiiiility.  The  iir(»ciicc  of  iron,  to  llie  extent  of  about 
0.006  jwr  cent,,  lis  intcn^tinf,  tiiia.;  n»  wc  shall  Bee,  there  arc  reiuons  for 
thinking  that  (he  nignient  of  bile,  itself  free  from  iron,  is  derived  from  iron- 
holding  hirniDKlobin  ;  snnie,  at  least,  of  tbe  iron  set  free  during  the  cotiver- 
sion  of  btemoglobin  into  bile  pigment,  which  probably  takes  place  ia  the 
liver,  tinds  its  way  into  tlie  bile.  Bile  also  nppean  to  contain  s  small  ifuaii- 
tily,  at  all  cveniB  occasionally,  of  other  metals,  such  as  manganese  and  cop- 
per ;  melaU  introduced  into  the  body  are  apt  to  be  retained  in  the  liver  aud 
eventually  leave  it  by  the  bile, 

Tbe  small  quantity  of  fat  present  consists  in  part  of  tbe  complex  body 
lecithin. 

The  peculiar  body  eltoU^erin,  which  tbou|{h  fatly  looking  (beoce  tlte  name 
"  bile  tat ")  is  really  an  ak-ohol  with  the  com|K)(iiii»u  C^H^.O,  in  coiupicuoas 
by  ila  ijuautity  and  i.-ouslancv.  It  furmd  the  greater  tmrt  of  moiit  gall'MoDca, 
thou^'h  »ome  are  comiMiited  i-iiietly  of  pigment.  luiMilubk  iu  water  and  col<l 
alcohol,  though  soluble  in  hot  alcohol  and  raudily  woluble  in  ether,  chloro- 
funn,  etc..  it  la  disaolved  by  the  bile-aalts  in  aqueout  tolutiim  and  bcnre  is 
p^c«^nt  In  Milution  in  bile.     Us  |>hysiolo|ricnl  functions  arc  olucure. 

The  n»h  of  bib'  ci>rigials  largely  of  uraa,  derived  partly  frum  the  H>dium 
chloride  and  |>nrtly  from  the  bile-salts,  of  sulphates  derived  chiefly  if  not 
wholly  from  the  latter,  and  of  phospbatoi  partly  ready  formed,  and  in  pan 
derived  from  tbe  lecithin. 

§246.  Pigmenlt  of  bile.  The  natural  gulden-ret)  color  of  normal  human 
or  carnivorous  bile  is  dne  to  the  presence  of  bilirubin.  This,  which  i»  also 
tbe  chief  pigmentary  ranstltuent  of  gall-stonei:,  and  occurs  largely  in  the 
urine  of  jaundice,  may  be  obtained  in  the  form  either  of  an  orange-colored 
amorphous  powder,  or  of  well-formed  rhombic  tablets  and  urisnis.  In- 
soluble in  water,  and  but  little  soluble  in  ether  and  alcohol,  it  is  readily 
aoluble  in  chloroform  imd  in  alkaline  fluids.  Its  compo&itian  ia  C„H„Nj(V 
Treated  with  oxidizing  agents,  *uch  as  nitric  acid  yellow  with  nitrouit  acid. 
it  displays  a  siicceteion  of  colors  iu  the  ordor  of  the  spectrum.  The  velluniih 
golden-red  becomes  green,  ibia  a  i;reenisli-hlue,  then  blue,  next  violet,  after- 
ward a  dirty  red.  and  finally  a  pule  yellow.  This  chnracteriBlic  reaction  of 
liilirubia  ia  tbe  basis  of  tbe  so-called  Onielin'!<  tett  for  bile-ingnientH.  Each 
of  ib(»  Biases  repreeenla  a  distiuut  iiigmeutarv  >ub«tance.  An  alkaline 
BulutioD  uf  bilirubin,  expnaed  in  a  shallow  Tinsel  to  the  action  of  the  air, 
luriiB  green,  becoroiufc  converted  taio  bilivmiin  (<'„H„N,0,  or  C,(H„N  Oy 
3laly),  the  green  pigment  nf  lii.'rbivor»u»  bile.  Bilivenlin  in  aldi  found  at 
timts  in  tbe  urine  of  jaundice,  and  in  probably  the  body  which  givtt  lo  bile 
wbich  hiu  been  cxpwcd  to  tbc  aolinn  of  goxtric  juici;,  ii(  in  bilmrv  vomits, 
itM  chiiracteriittic  green  hue.  It  is  the  lirAt  atagi*  of  the  oxidation  of  bilirubin 
in  GnHtlin's  Icst.     Treated  with  oxiditing  agents  hiliverdio  runs  tbrmigh 


the  Mime  seri»  of  colors  nn  bilirubin,  with 
golden  red. 


the  exception  nf  tbc  Initial 


BILE.  858 

I  9M.  TV  bite-m»lts.  Thow  coimst.  ia  mnn  tad  nifttiy  nniniRl*.  ottodium 
fhftatMaU  uid  loutvfhotaU,  the  proportion  of  tho  tiro  vamni;  in  dilfcteiit 
■aimmk.  In  ouin  bolh  Lbc  total  i{iiBnlity  of  bik-ealta  and  the  proportion 
■if  iIm  utw  bile-skU  torhe  otWr  swm  to  vmrv  n  ^'oi^d  deal,  but  the  glyoochoUto 
kftMtid  to  b«  always  the  niorv  nbundant.  In  ox-gall  eodium  glyeocholate  ia 
■fawidwDl.  and  Mtinicholalc  HcaDty.  Th«  bil«BalL»  of  the  dog.  cat,  bear,  and 
athar  evuivora  nxtMst  exchi»ivolf  of  the  latter. 

Iimlubte  in  ether,  but  soluble  in  alcohol  and  in  water,  the  aijueoite  sola- 
OM  havJDfc  a  dei-iOed  alkaline  retiotiiin,  both  tuilta  may  be  obtained  by 
crrrtallixatiun  in  fine  acitular  needles.  They  are  eieee<liii(;ly  dcliijiieacent. 
T&c  -wlutioui  of  Ixith  aci<U  have  a  dextro-rotary  action  on  polarized  li);ht. 


,- '»M.    Bil«,  mixed  with  animal  charcoal,  ia  evaporated  lo  drynew  and 

•xtnuTird  with  alcohol.  If  ogt  coloriest,  the  alcoholic  nitrate  must  be  fiirlber 
(l«<Ri((iriccl  with  soiinii)  charooal,  and  tho  alcohol  •littillFd  off.  Thr  dry  r^Miduc 
it  trcaud  with  absolute  ali-obol.  and  to  the  alcoholic  lillratc  aiihydroui  olhiT  U 
added  ••  10D(  aa  aor  precipitate  in  formed.  On  vtaudiug  tlie  doudy  precipitate 
haODBiei  tiannibrmed  into  a  erTMalline  tnaa*  at  the  bottom  of  the  vea»el.  If  the 
akohol  be  not  alMilute,  ibe  cr^Hala  ore  very  apt  to  bo  rbanK4wl  inui  a  thick 
■yrvpy  fluid.  Thi*  mmvi  of  erTntab  hw  b<^n  ollon  apoken  of  nx  Win.  lioth  «alta 
ar«  thu*  pKcipiiatod.  wi  Uiat  in  surli  a  bile  lu  thai  of  the  ox  or  man  biliu  oon- 
»bto  both  of  B'^Iiuui  glri-ucholitie  and  soJiuiu  taurocbolatc.  The  two  may  he 
•rjiarated  by  preci  pitta  Ion  from  their  aqiiMiua  solution*  with  vnicnr  i>(  lend,  wtiich 
larows  down  tho  former  much  more  readily  than  the  lultet.  The  acids  mny  be 
■ayakratsd  from  tlieir  mwclivp  salta  by  dilute  aulphuric  acid,  or  by  Uie  action  of 
md  aeelaie  oad  aulphydric  acid. 

Oo  bofllng  with  dilute  acids  (aulphuric.  hydrochloric),  or  caustic  j>otneh 
nr  baryta  water,  glvoichidic  acid  in  »plit  u|)  into  cholalic  (cholic)  aoid  and 
glydn.  Taurochofic  acid  may  similarly  be  split  up  into  ch«Ulic  add  and 
uuria.    Thua : 


I 


K 


(HreoctwHc  uU.  Ctaobllc  aetd  uljoln. 

f,HaNO,+  11,(1  =  C„H„0.  -  CH,.Na,  (OO.OH). 

TMunehoUe  urtd.  lliulallc  add.  IViulii, 

Ci,H^SO,  f  11,0  =  C„Il«U,  -i  C,H..NH,.S<I,!I. 


Berth  aoda  contain  the  aame  non-nitrogenona  oeid.  cholalic  acid ;  but  this 
acid  ie  in  the  lirai  caae  WMocialed  or  conju){ated  with  the  importnut  uitro- 
^enoua  body  glycin,  or  amidoacetic  acid,  which  U  a  compound  forme<I  from 
anHDonia  and  one  of  the  "  fatly  acid  "  scriee,  vii..  acetic ;  and  in  tlie  »ccoiul 
can  with  taurin.  or  amido'i<elhionic  acid,  that  is  a  coranound  into  nhicb 
wnfMenlativcB  of  ammonia,  of  the  ethyl  ([■^'■I'-  ^o^l  ^^  aulphuric  acid  mter. 
The  dev(»mpueilioa  of  the  bile  acidi  into  cholalic  acid  and  taurin  or  glycin 
napectirely  takea  place  naturally  in  tne  inteadue,  the  glycin  and  Iiiurin 
b«iiK  priibably  alMorbed,  <»  that  from  the  tno  acid*,  afUir  they  liavo  wrved 
llwir  purihtw  in  dinuion,  the  two  ammonia  oiimjiouu<b  are  rvIurniM)  into  the 
MoimI.  Kacb  of  the  two  acid*,  or  cbolalic  aeid  nhme,  w1m-xi  treated  with 
*ul|>huricaddaiid  mne-dugar,  );iveHaraa)(iiihi;eut  purpk  color  (Pctteakuler* 
Ual),  with  a  cluiraoterutic  Bpectruoi.  A  aimilar  oolor  may,  however,  ntlen 
W  pruducet)  by  the  actiou  ot  ibe  aame  bodioa  on  albumin,  amyl  alcohol,  and 
ium*  other  oi^anic  budiet. 

$  M7.  AttwH  of  bift  on  food.  Id  aom«  aitimak  at  leatt  bile  cootaim  a 
fnvH-nt  ca I akble  of  Converting  atarch  into  mgar;  but  its  action  in  this  reepect 
it  wlmlly  MilinrdtDAtc. 

On  proteiiU  bile  hu  no  direct  digwtiftt  action  whatever,  but  being,  |;eo- 
fntUy  at  leaat,  alkaline,  and  often  atroogl;  so,  tonda  to  iieutraliM  the  acid 

2i 


THK    TIS9UK8    AND    MKCUAKI8M9    Of    U1GB8TI0N. 


oonteuiii  of  the  stomach  km  tbcy  jMtt  aHo  the  duodenum,  and,  as  we  attall 
Me,  w>  jirvjiarctt  Uit'  vikv  for  the  nctioD  of  the  pnncreulic  juioe.  To  peptic 
action  >t  i»  dUtiiiellv  Buiti^Hiiittiv;  the  prcaeuce  of  n  suflident  i|uaDtiir  of 
bile  rendera  Ki><>tHc  juice  inert  toward  proteida.  Moreover.  wh«n  bile,  or  a 
BolitdoD  of  bili-'MiltH,  is  niltkd  to  a  fluid  oootaiDtag  the  products  of  gaeuic 
dig«etioD,  a  pR'cipiiute  tiikes  place.  eoDMitin^  of  [Mtrapeptoiie  (w1i«d  |ir«sefil), 
peptone,  |iep«in.  iitid  liile-ults.  The  precipitate  ia  redueolved  iu  au  ezoeH 
of  bile  or  sohiiinn  of  bilc^sfilt«:  bill  the  pepsin,  though  rediaaulved.  reauiD* 
inert  lownrd  proteids.  This  precipitation  actually  do«B  take  pluc«  It)  the 
duDilenum,  mid  we  »hall  »peak  of  it  again  later  on. 

Willi  regitrd  to  the  action  of  bile  oo  fats,  the  followinj;  stmXemeata  mar 
tw  Riadi? : 

Bile  haa  a  slight  solvent  a<.-tiou  on  fats,  as  seen  in  itii  uat  by  painter*.  It 
ba«  by  itself  a  elJjilii  but  only  aliiihl  emulsifying  iwwcr:  a  mixture  of  oil 
and  hile  separate  after  shaking  FBtner  leaa  rupidly  tnan  a  mixture  of  oil  aiid 
watrr.  With  fatly  acida  bile  forms  M^a])s.  It  b,  more<;ver,  n  mlvoot  of  solid 
euHpi>.  and  it  would  appear  that  the  emulsion  of  fal«  if  under  ccrtAio  cireum- 
Blancc*  at  ttll  events  facilitated  by  the  proienoe  of  MWfw  in  solution.  Henoe 
bile  i»  pnilmbly  ut  much  grenter  line  an  an  eiuiiUiDn  aernt  when  mixed  witb 
panerentie  Jiiii»  than  when  aclinj;  by  ilnclf  alone.  Ti>  this  poitil  we  $hall 
return,  Lnntly,  the  pastui^  of  Ints  thnni^h  niemlimncs  I;"  ii!«ist«<)  by  weltini; 
the  menibrani')'  witli  bile  nr  wirh  a  solution  of  bilcsnlls.  Oil  will  poas  to  a 
certain  extent  through  a  tilter-pAper  kept  wet  with  a  iohitioD  of  bile-Mils, 
whereas  it  will  not  pa.-«  or  naaeea  with  extreme  difficulty  through  one  kept 
constantly  wet  with  distilled  water. 

Bile  pnmrmni  some  aJitiiieptie  qualitiea.  Out  of  the  body  its  preaeuce 
hindea  vaHous  putrefactive  proceaK* ;  and  when  it  is  preveut«it  IVoin  llaw> 
ins  into  the  alimpntarr  canal,  the  content?  of  the  inteatine  undergo  changra 
diflbrcnl  IVom  those  which  take  place  under  normal  condilioiiK,  and  leading 
to  the  ap|>earanoe  of  various  products.  ei[>e(-ially  of  ill-timelliDg  euee. 

These  lariuus  actions  of  bile  seem  to  oe  dependent  on  the  bn»«alle  and 
not  on  the  pigineiitary  or  other  constituenis. 


Pancrralic  Jutw. 


« 


§  248.  Natural  healthy  pancreatic  juice  obtained  by  means  of  a  temporary 
paocruitic  fiittula  differs  from  the  digestive  juice*  of  which  we  bate  already 
moken  in  the  ooinjmratively  large  i|uantity  of  proteids  which  it  cuntaina. 
Iu  conipocition  vanes  according  to  ihe  rate  of  secretion,  for,  with  tlie  mora 
rapid  flow,  the  increajte  of  total  solids  dues  not  keep  pace  nilh  that  of  the 
water,  though  tin-  uvh  remaiuit  remarkably  conslaul. 

By  an  incision  through  tlic  liiiea  alba  the  paDcreatic  duet  (or  ducts)  uan  easily 
be  lound  ailher  in  the  rabbit  or  in  the  dog.  and  a  caoula  secured  la  It.  There  b 
no  difficulty  about  a  lemjioRiry  (Ixiula:  but  with  ponnanont  fisiulie  Ihe  secrelion 
b  apt  to  lieeome  altered  in  nnVure.  and  to  Imc  many  of  its  characiflriatic  proper- 
llCH.  gome,  however,  have  mccredcd  in  oblaiiilng  permaaent  fiatulie  xritbout  anjr 
Impairmeni  «r  (he  tweretiou. 

Healthy  pancreatic  juloe  is  a  clear,  somewhat  viscid  fluid,  frothing  when 
•baken.  It  has  a  very  decided  alkaline  reaclioii,  and  coniainN  few  or  no 
ftrudural  ooustituenls. 

The  average  amount  of  solidi^  in  ib<-  piiucrealie  jiiicc  (of  the  dog)  obtained 
i'rotd  a  tan)]M»an-  listula  is  nboiil  H  to  10  jkt  cent. ;  but  in  even  tJiorougbljr 
active  juice  obtained  froin  a  permanent  fiMula  if  not  mors  than  about  2Ut  a 


no  juicK. 


886 


* 


\ 


per  «HiU,  0,8  lK>iiiK  iitor^nic  mulicr:  nnd  th»  i<  probablr  the  iionnal 
■moant.  Tbe  iniiMtrittDt  conviiiudile  of  quii«  Imh  juice  are  albuoiia,  a 
ptealbr  fonn  of  nrotegd  allied  to  mirosin.  giving  rise  lo  a  son  of  clouinj;.  a 
MMilI  atnoaDtornta  andsoape,  andacompnratirely  Inrge  quaDtil}*  oraadium 
oarbocMte,  lo  whidi  ibe  alkaline  reMtion  of  tbp  juiiie  is  due,  and  which  seenu 
In  b«  pecaliarl}'  aaaodatcd  with  the  proteids. 

Sace,  a»  we  shall  piewDtlr  see,  pancreatii.'  juice  eontaiofi  a  ferment  acting 
*ser|{clicallv  oa  )>rt>ie»d  luatten  in  an  alkaline  medium,  it  raf>iiily  dig^la 
H»  own  proWid  miwliluenu,  attd.  wbi-n  kei>l.  speedily  chauKea  in  cliarai.-ter. 
Tbc  mjraain-likf  Hot  b  duaulved,  and  the  juice  soon  couiains  a  peculiar 
Hirm  fif  alkali-albumin  ({irectpiiuiablt-  bj-  HUiuration  with  majKneaium  nul- 
pb*lv).  a*  K'idl  R»  omnll  qiiiintilie*  nf  leucio.  tynMiu.  and  peplune.  vrbich 
ttvio  Ut  b*  tlif  nnxluct*  uf  neir-di^'Mtion  aud  ui«  entirely  atment  from  tbe 
perftvUr  liMb  juice, 

f  MS.  Aelion  ON  faod-Mu^.  Oo  «IarcA  ]mn4-rentii-  uiioe  acU  with  gmU 
rapidly  oonTertiDg  il   into  NUgar  <chielly  malloae).     All  Ihat  bu 


in  ihi*  nepect  ciini^rniii^  Milivii  might  Ixi  repealed  in  ibe  4!iue  of 
pUtcrfWie  j»i<«,  execj)!  that  tlie  iicttvitv  of  tbcHattrr  in  liir  gimilrr  than  that 
td  iIn  feraM>r.  i'nncreBlic  jnicr  and  iW  aijitepuK  infunion  nf  tho  gland  are 
•twars  capable  of  mnverUng  starch  intn  Diigiir,  whether  the  animal  fmm 
whidi  Ihey  were  taken  be  iianHne  or  wcilt  l«<T.  From  tbr  jtiioe,  or,  by  tbt 
gljnariii  method,  from  the  gland  ilaelf,  an  amylolytic  fi-rmeat  may  be 
•pMWlimat«ly  isobited. 

On  f/rot^iiU  pancreatic  juice  also  exercises  a  Nilveiil  aclion.  so  far  similar 
Ut  that  of  {[astric  juice  ihM  by  it  proteids  arc  I'ODVerted  into  peptouc.  If  a 
fr^  Anib  o(  fibrin  are  thrown  into  a  small  iiuantity  of  pancreatic  juice, 
tbey  apeedilr  diaiippc«r.  especially  at  a  tempcralure  of  35°  C,  and  tho  mix- 
tare  it  found  toaMitaiu  |W|>{^ne.  Theaclivity  of  the  juice  in  lliua  converting 
proUMb  tDto  iie|>tijnc  ii>  lavore<l  by  iner^une  of  tfimjieratiire  ui>  to  40°  or 
iTmtilliiUlli.  and  himlrred  by  low  u-tn{ivrikliin«;  it  in  jiermaiientiv  deMiroy«d 
bv  boiling.  The  digaitive  imwt^ni  of  tbc  jiiiu'!  in  fact  de[Mnil.  like  tbi>M  of 
IfHCric  juicv,  <>n  tbo  prvciire  <>f  a  fernieiil  uhii'h,  a*  we  havr  already  oaid, 
nay  be  boloittd  mueli  in  tbi?  «anie  way  lu  {tepnn  i«  inalatvd,  aud  to  nhiob 
tbe  tume  trjpnn  bns  been  ^ven. 

The  appewmDoc  of  fibnn  umlcrguing  pancrcatii'  digc«lion  is,  however, 
Jiftimt  fron  that  undergi>ing  [wpiic  <Iige«tion.  In  Uie  former  nur  the 
ftbcia  doei  not  swell  up.  but  remains  n«  opiujue  as  before,  and  appears  to 
Miflhr  eorroaion  rather  than  solnlinn.  Itut  there  is  a  still  more  important 
diitituAJoD  between  pancreatic  nnd  peptic  digestion  of  proteids.  Peptic 
ilimlioa  is  toKutially  an  acid  digestion  ;  we  hare  seen  that  lh«  action  only 
laua  plaee  in  the  presence  of  an  a<'id,  and  is  arrasled  bv  neutralixnlion. 
PWwnatM!  digeatium,  on  tl>e  other  band,  may  be  regarded  as  an  alkaline 
iljljllliili ;  the  action  b  nmet  ener^tic  when  aomc  alkali  is  prceent.  and  the 
amrkj  <^  an  alkaline  juice  is  hindered  or  delayed  br  neutralization  and 
■iiiti  by  acidiReation  at  least  with  mineral  acada.  The  glycerin  extract 
of  paDcnaa  ■  untb-r  all  circuniotancea  as  inert  in  the  presence  of  free  mineral 
■M  ■  that  of  the  uttiinacb  iu  tbe  presence  of  alkalies.  If  tbe  digestive 
■ixnm  b«  nppticd  with  sodiuai  carboDat«  lo  the  extent  of  1  per  cent., 
dteatlen  proceed*  miiidly.Jitat  as  doee  u  peptic  mixture  when  acidulated 
wUb  kj^rodiWic  acid  to  tbe  extent  of  O.'i  net  cent.  S>x)ium  cnrlronale  of 
1  per  omL  aeemi  in  fact  In  nlajr  in  tnrplic  alftestioD  a  part  altogether  eom- 
pniablr  Iu  that  of  liydnichloni-  acid  of  0.2  Mr  cent,  in  gartric  diMstion. 
And  jiist  as  pe|isin  is  rH]>i(ily  tkviruyed  by  being  Itcntnl  to  about  40°  with 
a  1  perceoL  aolulion  of  mHliuni  oarlHinalc,  so  iryiMin  is  ramdW  d««K>jed 
by  heUK  similarly  bcatnl  with  dilute  bydiw:hloric  acid  ut  O.X  par  eenL 


S&6        THE   T1S3UK8    AND    MEmANlSMS    ()>'    DiaKSTlON. 


Alknline  bil«.  whidi  nrrmu  jieptJc  dtgesliuu,  seeraa.  if  xnylhiuK.  GiTorable 
to  Irriitic  digution. 

Cornvpouding  to  lliix  dilTfrence  in  tliu  lietpmale  nt  Out  fernwrn,  ih«re  to 
in  the  two  ciua  ■  diMVri-ii<-«  in  thv  niilure  of  the  producU^  In  both  CMm 
peptone  is  prwliicyd,  wni  itiich  ilifliTca (■<■-■<  lu  can  be  dcb«Uyl  betWMin  iwn- 
erratic  and  gnslric  pt-ptoNtv  an.-  rvlntivi'ly  kiuhII  ;  but  in  iiancrcntic  di);(slion 
the  bye-product  is  not,  n»  in  giwtric  digcctinn,  a,  kiod  iif  ncid-albiimio,  but, 
OS  might  bo  expected,  it  budv  hiivint;  more:  analogy  wilb  Klkali-Klbumin. 
Moreover,  before  the  iilk)ili-nl!i<imin  is  iicLiinlly  Ibrnted,  the  fibrin  becoinee 
altered  and  takes  od  eharnctcre  iiiiprnicdiiilc  between  those  of  alkali-albumin 
and  of  ordiuary  albumin ;  ntiii  when  fmti  raw,  i.e.,  unboiled,  fibria  is  acted 
upon  by  paiierealio  juice,  one  or  mort-  (ilohiilins  appear  a»  initial  products. 

Further,  there  are  evidences  that  <lilicrenc«8  of  even  a  more  profound 
iinlurc  than  the  above  exi^t  beln'ecii  puncretilic  and  gastric  digeetioD.  One 
o(  lbi9«  is  the  appearan<%  in  the  pancreatic  dit>es[ioD  of  proteidi  of  two 
roninrkable  nitrogenous  crystalline  bo<lic8,  leitcin  and  It/mtin.  When  fibrin 
(.i>r  other  prolcid)  is  submitted  to  the  action  of  pancreatic  juioe.  the  anioont 
of  peptone  which  can  be  recovered  fVoni  the  mixture  falls  ftr  ihort  of  the 
original  amount  of  proieids,  luuoh  more  so  than  in  tlie  caae  of  gnMric  juiw: 
and  the  lunger  the  di^tive  action,  the  greater  is  tht.«  apparent  Inn.  If  a 
pancreatic  digestive  mixltire  he  freed  f>om  tlie  alkali-albumiu  hv  neutmliu- 
tion  and  filtration,  the  fdlrate  yields,  when  CDiiceniruled  by  evnponuion,  a 
crop  of  trj-atnls  i>f  tyriisin.  If  these  lie  reinoved  ibt  peptone  may  bo  prc- 
ci[>i|jit<'d  fnim  the  on  cent  rated  fdtrate  by  the  addiiinn  of  a  largo  fixccoa  of 
alcohol  anil  M-puratcd  by  liltration.  The  necond  liltratc,  upon  being  concco* 
Initcd  by  evaporation,  yield*  abundant  cryatala  of  Icucin  and  Imcea  of 
tyroein.  ThuK,  by  the  action  of  the  pancreatic  juice,  a  ooneidernble  amotint 
of  the  prolcid  which  \t  being  iligv«l>.^l  i»  *o  broken  up  ns  to  fpve  rise  lo 
products  which  arc  no  loncor  proteid  in  nature.  From  this  breokiuj;  up  of 
the  proteid  there  arise  leucin,  tyrosin.and  probably  several  other  bodies,  such 
as  fativ  acids  and  volntile  substances. 

As  ir*  well  known,  leucin  and  tyrosin  are  Ihe  bodies  which  wake  tbotr 
appearance  when  proieids  or  gelatin  are  acted  on  by  dilute  acid«,  alkalies,  or 
various  oxidizing  agents.  Ll^ucio  is  a  body  which,  in  an  impure  state,  cry»> 
talliusi  in  minute  round  lumps  with  an  obscure  radiate  xlrialton,  lint  when 
puri'  forniB  thin  Kliltering  flat  crystals.  It  has  the  formulo  <',H  NO,  or 
VjH.j.NH,  I.C0.O1I1,  and  is  nmido-eaproic  acid.  Nnw,  caproic  acid  is  one 
of  ihe  "  fatty  uciil  "  series,  so  that  leucin  may  be  regardeil  iw  a  compound  of 
ammonia  with  a  fatty  acid.  Tyrnsin,  t\II,,NO^.  on  the  <ithcr  hand,  be)ao)>B 
to  the  "  ari>matic  "  9vti<»  ;  ic  is  n  phenyl  c>rupounil,  ami  hence  idlied  to  betl- 
xoic  acid  and  bippuric  acid.  >hi  that  in  pancreatic  dimttion  the  laice  com- 
plei  proteid  incileciilr  in  nplil  up  into  fatty  a(rid  anil  aromatic  tnoIeculM, 
Bome  other  IkkUw  of  ItM  imjKirtance  making  their  appearance  at  the  same 
time.  We  infer  that  tlie  proteid  nioleculei  are  in  some  war  built  up  out  of 
"faUy  acad"  and  "arcmatio"  molecule*,  logothor  with  oilier  componenia, 
and  we  sliall  later  on  wc  additional  rmsotw  tor  this  view. 

Among  the  HU]i|iknii-ntary  nniducls  of  poucrmtic  digestion  may  Iw  men* 
tioBed  the  body  imtol  (C,H,N),  to  which  iip|>nrcnily  the  strong  and  pocii- 
Uarly  fecal  odor  which  someiimt*  m[ik<;:>  it*  amx'nrance  during  ponorcaiio 
digeUion  is  due.  Indol.  however,  unlike  the  leucin  and  tyrneiu,  b  »oi  It 
product  of  pure  pancreatic  digeclion,  but  of  an  accompanying  decompoailiiMl 
dUB  U>  the  action  of  organized  ferments.  A  pancreatic  digeUive  uixtiira 
•OOH  beoomee  swarming  with  bnclcria,  in  spite  of  ordirinry  preeautiont,  whon 
naiural  juice  or  an  infusion  of  the  gland  is  used.  When  iaohiterl  ferment 
to  ined  and  atmoepberic  germs  are  exdtided,  or  when  |>au«reativ  digestion 


PANCBBATtC  JCKE. 


M7 


I 


I 
I 

I 


m  eanied  on  in  tb*  pfceencc  of  inlicylic  acid  or  tlirmol.  which  prevent  tho 
(WvdofNnmi  of  baclfrin  anii  lik>^  organUm  l>iit  permit  tho  action  of  thu 
trjotio.  no  odor  is  |tcrc<'ivccl  nnd  no  indoi  n  produced. 

Aft«r  lonp;-c»i)tinticil  di);c8tioi).  cs])cciullT  uhen  R«.-ompanied  by  putre- 
iMStfn  deo>n>p'>«iti<<ti.  iho  ftmoiint  of  pmccids  which  nro  carried  boyotnl  the 
fwptoiM  tH^gf  nnd  broheii  up  may  be  very  i^mil. 

Id  f^utric  digCBtwa  such  a  profound  destruction  of  protcid  nititcrial  occurs 
to  «  rauch  lem  extent  or  not  at  nil ;  neither  loucin  nor  tyrosin  can  at  prflseot 
b*  eonmdered  as  natural  products  of  the  action  of  pepsin. 

On  lite  |elaltniferoii8  elements  of  the  tissues  lu  they  actually  exist  in  the 
timoK  preTHMi*  to  any  treatment,  pancreatic  juice  appeHra  to  have  no  solvADt 
action.  The  flbrillie  and  bundles  of  librillse  of  ordinary  unlouched  con- 
DxtWc  tissue  are  not  dif^ed  by  pancreatic  juice,  which  in  this  respect 
aflbrds  a  strikinf;  c»uirtii<t  in  trastric  jutce.  But  when  they  have  been  pre- 
viooilj  Heated  with  acid  or  boiled,  i»o  ai>  to  becunie  convi-rieil  intu  uciuul 
nIatiD,  tripsin  is  able  in  diwolvt.-  thcrii.  itppareiitly  chaDjpnK  tbem  much  in 
Dm  mMot  way  as  dom  pepiuii.  Tryjwiu.  unlike  ]iein>iii,  will  di.-oulve  mucin, 
Lilw  pepiin,  it  is  inert  tuward  nucleiti,  horny  luwues,  and  the  so-called 
•inykad  matter. 

On  /aU  pnncmalic  Juicr  hii*  u  innfotd  action.  In  the  first  place  it  cmul- 
aMn  btik  If  hci^t'*  Urd  Ix-  gently  liciitMl  until  it  melt*  and  lie  thun  mixed 
with  paoon-alii'  juice  hefi>ri<  it  imlidilitv  c>d  cooHng,  a  criiiniy  cmnUinn  liMing 
£»r  almoal  an  indi-tinitc  lime  is  jV>rnii-d.  80  aim;  when  olive  oil  is  iiUnkeJi  up 
with  paocn-atio  juice,  ihe  wparniion  of  the  two  fluids  takes  place  very  slowly, 
and  a  dmp  of  the  mixture  under  the  micmecope  shows  that  the  division  of 
lb*  &i  is  venr  minute.  An  alkaline  aijucous  infusion  of  the  gland  has 
aimilsr  emutsinrnK  powers.  In  the  second  pince  pancreatic  Juica  splits  up 
ncutnti  falfl  into  their  respective  acids  and  glycerin.  Thus,  palmitin  (or 
tn|ialmttini(1-'iiii».C().U),.t',II,  is  with  the  a^umption  of  .'Ul.Udplil  up  into 
tbrr«  molecules  of  |ialniilic  acid  :i  (('„H„.CU.OH)  and  one  of  tclycerin 
(C,ll«)  vOH,) ;  and  so  with  the  <>ther  neutral  fal&.  if  |)erfeolly  iH-tttral  fat 
be  tnated  with  panoreatic  juiee,  eiiiie<-ially  at  the  body-tum|R.-rature.  t)i« 
■mullioa  wfaioh  is  formed  sptwdily  lakiv  on  na  acid  rtacton,  nnd  by  appro- 
priata  means  not  only  tbi'  ci>rri-)i{ii)ndini;  fatty  uddM,  l>tit  g^lycy^rin  mny  be 
obMimd  ftwB  the  mixture.  When  alkali  i*  preacnt,  the  fatty  nci<b  tliux  Kot 
fna  form  tlisir  oorrfspowling  soaps.  Pancreatic  juice  conlaiit*  faUi  aiul  is 
OOnsaqOMitly  apt  after  collection  to  hiiw  its  nlkulinity  rcdu<yd,  aitd  an 
•qnwus  innision  of  a  pancreatic  gland  1  which  always  contains  a  coiuid- 
•table  amount  of  fat)  very  speedily  becomes  acid. 

Ttius  pancreatic  juicv  isrsmarkablo  for  the  power  it  possesses  of  acting  00 
all  the  foodstuffs,  on  clareh.  fats,  and  prolcids. 

Tho  action  on  starch,  the  action  on  protvids,  and  Ihesplitting  up  of  neutral 
fiua  appear  to  be  due  to  the  presence  of  three  distinct  ferments,  and  rn«tb«la 
have  DMO  suggested  for  isolating  them.  The  emulsifying  power,  on  the  otber 
band, is nnnccted  with  the  general  compositionof  the  juice(orof  theaijueoua 
influion  of  the  gland),  being  probably  in  large  measure  depemleni  on  the 
alkali  and  the  alkali-albumin  present.  The  prole«lytte  ferment,  Irypbin,  as 
ordinarily  prepared  seems  to  be  proteid  in  nature  and  capable  of  giving  rise 
by  digestion  to  peptone;  but  it  may  be  doubled,  as  in  thecaseorpepeia  and 
otbir  fmuents.  whether  the  pure  fermeui  has  yet  been  isolated.  Tnere  are 
no  mewu  of  distinguishing  the  amylnlytic  fermeut  of  tlie  pancreas  from 
piyaliu.  The  term  pancr'--itin  has  li«ea  variouslr  ap]>lied  to  many  drlTerenl 
prvpaimlinns  fmni  the  glaud.  and  itn  use  bad,  perha|i«.  belter  be  avoided. 

Tbe  acti»n  of  paucr«atie  juice  or  of  the  infusion  or  extract  of  tlte  gland. 

I  aUn-h,  is  seiEii  under  all  circumstaiuns,  wbether  the  animal  be  fasting 


iHB        TUK    TlSai'KS    AXD    MECHAMISUS   OF    DIOESTIOK. 


nul.    The  miue  niav  probably  l>e  ^id  of  the  action  no  f»U.    0»  prat< 

the  DiittinU  juice,  wliuu  ULt^reled  ui  u  normal  state,  U  alwayn  active.     ' 

glycerin  cxtrani  or  anucous  iiirunJoii  »!' the  gland,  on  the  vomniry.  aa  we 
nave  alrea^ly  Gxplaineu  (^2:t>*),  iit  active  in  pfoportioo  aa  the  tryiwinu 
b««  been  (<»iivcn«il  into  tryjiain. 


Sufoat  Eiitcrieiu, 


re  IB  Itefl- 


§  200,  When  in  a  living  animal  a  portion  of  the  small  intotine  is  It^- 
lure<l,  nil  ibnt  the  eecretionB  coining  down  from  above  cannot  enter  ita  canal, 
whik'  yet  (he  blo()cl-i4iip|>ly  is  maintained  aa  uHuaJ,  a  small  amount  of  secre* 
tioit  colleutA  ID  it«  inieriur.  Tbis  is  spoken  of  as  the  menu  enUrieu*,  and  b 
•upposed  to  Im  furnished  by  the  glands  of  Lieberkiihn,  of  which  wre  shall 
preaentl;  q>eak. 

BuccuM  enterlcus  mav  be  obtained  by  th«  following  method,  known  at  that  oi 
Tkiry  modified  by  VpIIh.  Tho  umall  inmtiiiv  i«  divided  in  two  places  ai  some 
dlatancv  (3U  to  GO  oiii.)apait.  By  fincauuires  the  lower  end  of  tliouppofMClioa 
ia  carefully  united  with  the  upper  end  of  the  lower  auction,  ibua,  a*  it  were,  cut> 
tine  ^"^  "  **l>ole  pleci-  "f  the  small  iuioiliiie  Irom  the  ulimeiitnry  tract.  In  suc- 
eessAil  cases  union  between  the  cut  surfaces  lakes  (ilnce.  and  a  shortened  bui 
otherwise  satisfuctorv  canal  in  r«^'siablislied.  Of  the  liuilsied  piece,  the  two  ends 
are  He  pa  rate  ly  hrouent  through  incisions  in  the  nbdominal  wall,  anil  tfaetr  nianlh* 
carefully  fanlcDed  In  such  a  manner  that  each  ujouih  of  the-  uiece  open*  on  \a  thr 
cxlerior.  During  the  prooeas  of  healing  two  llntulie  are  Idub  eMablUied,  one 
leading  to  the  beginning  of  and  the  other  to  tho  ori<l  of  a  abort  tneca  of  IntMtine 
quite  Jsolaled  from  the  mil  of  tli«  alimentary  canal ;  br  nirsn*  »f  tbcH  Openings  a 
small  (|ijantity  of  lluid  can  be  obtained. 

The  ijuaiiUly  seeteted  Is  said  to  be  considerably  increased  by  the  adminisiratioa 
of  pilocarpiu. 


i 


Huccus  eutericus  obtained  from  the  dog  by  the  above  method  is  a  cl 
yellowish  tluid  having  a  faintly  alkaline  reaction  ami  conlAiuiug  a  certain 
quantily  of  mncus.  It  is  said  to  convert  siArch  into  ^uj^ar  and  pfoteids  into 
pcpI'Kie  Uhe  action  being  very  similar  to  that  of  |Htticreuti<'  juice),  to  aplit 
np  neulrul  fat<>.  t>i  emiiL^ify  fuls.  and  K>  curdle  milk.  It  is  also  aiud  to  con- 
vert nipidly  cane-.^ngar  inl»  graiie-sugar,  and  by  a  feriuuutative  notion  to 
convert  cane-sugar  into  lactic  aiMd.  and  this  again  into  butyric  acid,  willi 
Uio  evolution  of  carlmuic  nci<l  an<l  free  liyilmgeti. 

According  to  the  above  rMtili.'>  .■>iiccii!>  enlericus  is  to  be  ngardedaaao 
important  nvcretJon  acting  on  all  kindu  of  food.  But  even  at  its  be«t  iia 
actions  nro  i'l'>w  and  tl-chlc.  Moreover,  many  olHN-rvrr*  have  obluincd  nega- 
tive results,  so  ihnt  the  various  stalomcots  tuv  conflicting.  Besidus,  w«  havo 
no  exact  knowMge  as  to  tho  amount  to  which  such  a  tccrotion  take^  place 
ander  normal  circumstnncc*  in  the  living  body.  Wc  iniiy.  thcrefbn?,  con- 
clode  that,  nt  present  at  all  evcnb^  no  have  no  satislnctory  reasons  for  sup- 
pcning  tliai  the  acinal  digestion  of  food  in  tlie  intestine  is,  to  any  great 
extent  aided  by  auch  a  juice. 

Of  ibo  powible  action  of  other  secretions  of  the  nlinientarr  canal,  as  of 
the  oecum  and  lar^  intestine,  we  shall  speak  when  we  come  to  consider  the 
obaniEee  in  the  alimentary  canal. 

%w\.  QaU'rimtti.  Conerelimw,  often  of  coD§>idembIe  size,  known  oa  gall- 
MOneaarenot  unft«quently  lormed  in  the  gall-bloilder,  and  smaller  concro- 
Uons  are  sometimes  formed  in  llie  bile  naiHiges.  In  man  two  kinds  of 
gallistonea  ore  ounmon.  One  kind  cwuists  almottl  entirely  of  cholcsiorin. 
sonietimes  nearly  fVee  Arom  any  admixture  nilh  pigment,  somoiimos 
more  or  liiw  discolorcil  with  pigment.  Oall-stonra  of  thi«  kin<I  have  a 
crystalline  structure,  miMl  wlwn  broken  or  cut  show  frG<|ilvntly  radiaManii 


SKL'ltKTlDX    or    PANCREATIC   JUICE    AND   OP    BILE.      359 

nooMilfic  Rwrktngn.     The  otber  kind  «io*i*u  cJiiefljr  »f  bilirubin  in  com- 

Mwitlun  Willi  cmldiim.     Giill-«tODC«  nf  tlii»  kind  urv  <Inrk-TOlorcd  uid  amor- 

jtum,     L<n  Doninii>n  thnn  (lie  «buvQ  nrc  «mnll,  dark-oolorcd  DtoDC*,  liavlog 

■  nalbnry  shape,  k-misieting  not  of  biliruliln  tiMlf.  bul  <^r  one  or  vth«r 

ktite  of  bilinibin.     Gnll-stoncB  coiLsisting  nlmml  cnlircl)'  of  inorgtuiio 

ailcic  c«rbonata  and  phoafduites,  rnn  nlso  ocvii»i<>nitlty  met  wilh.     Iti 

lower  ttnimab.  in  oxen  for  iosUaoe,  bilirubin  gnll  atoacs  «ro  not  unvoni* 

mota  .  btit  cl(olat«rin  gall  Btaoea  »n  tm. 

A.  pUI-stoiw  Kpp«ara  alirayv  to  contiitii  ft  motv  or  Ion  obvious  "  niiclou*," 
uound  vliicfa  ibe  mauHal  of  tbe  stone  hat  becii  dop(wit«I,  and  which  nofty 
!■*  VVaided  oa  the  origin  of  ibe  «lone ;  the  rcnl  cauao  of  the  formation  of  ihii 
*lii*ha1iei,  bowever,  in  certain  chanj^ee  in  the  bile,  by  which  the  choleetorln, 
•f  l*ilinihiii.  (ir  ulbi-r  cooalitiient  oeaaea  to  [«niain  diaeolved  in  the  bile.  Dut 
*■  caouot  dbteust  this  mutter  here. 


TUK  SeCKETIO!!   op    rAXCKEATK;   JuiCK   AKD  OP   BiLK. 


I  t  SH.    The  tffrttwn  of  panaytfir  Juie^.     Although  in  Hunio  cmos,  m  that 

k^  tbe  p«raljd  of  the  sbvep,  the  Bow  of  mliva  in  con  tin  nous  or  nearly  bo,  in 
^^Pm  ■Ainuls.u  in  man,  tbe  intortnitt<-M(.-i-  of  the  «ecre<ion  is  very  nearly 
ibolule.  While  food  ia  in  thr  mouth  mIivu  dowit  fnidy,  but  helneeii  meala 
only  juM  aoliimtnt  is  srcrvted  to  ket'|i  ihi-  mouth  mniHt,  and  probably  (he 
rwtar  part  of  this  is  supplied  n»t  by  the  l(up;r  nalivary  hut  by  the  Amall 
Euooftl  ([lamia.  Tbo  flow  of  pnncretitic  juice,  '>n  the  other  hand,  is  much 
BOre  protonged,  being  in  tbe  rabbit  continiioos.  and  in  the  do;;  lastiuK  for 
twMitT  bours  after  food.  But  thi»  eontrnst  helwcT'ii  the  secretion  of  tuliva 
aod  taat  of  pancreatic  juice  it  natural.  «iucc  the  ftay  of  food  in  the  mouth, 
una  during  a  protntcti^  feast,  in  relatively  short,  wliereot  the  time  during 
wblcb  tbe  Dtalenal  of  a  meal  is  able  in  aouie  way  or  other  to  afiect  the  pan- 
trma  h  ^•rj  prolonged. 

Tba  flow  thouBh  coDtinuoua,  ur  nearly  bo,  i*  not  uniform.  In  the  dog  tbe 
fluw  of  pancTMlic  juice  b^ns  immediately  aHer  food  baa  l>ocn  tiiJton,  and 
tias  to  a  maximum  which  may  be  reached  within  (he  Rm.  or  as  in  the  caae 
Aimi«liing  the  diagnoi  given  in  Fig.  1 1 2  tlie  Nceund  hour,  but  which  more 
caninwnly  ia  not  reached  until  (ho  thinl  or  fourth  hour.  This  rise  ia  tlien 
fall»wtyi  by  a  Imll,  aAer  whii-h  tlHTt^  i*  a  xi-ronilary  rise,  reaching  a  eeoond^ 
mazimtim  at  a  very  vitriable  time,  but  gntemlly  between  tbo  fifth  and  eevmtil^ 
hours.     Thix  second  ninximum,  however,  i«  never  m  high  as  the  Rral. 

Tbe  Beoond  rise  may  be  doe  to  ninlerial  alimtbed  from  the  inteatiiies  beioff 
CBfried  in  the  circulation  to  iho  pancreaa,  and  >o  direoUy  excitin);  the  glaiHt 
to  activity,  much  in  the  aame  way  at.  in  toe  cnae  of  tbe  ttomoeh,  the  iilu-jrp- 
tlao  nf  digolad  naterial  promotes  (he  flow  of  gastric  juice,  see  $  '2^2  ;  and 
a  aioiilar  ahaorptioa  may  contribute  \a>  tlie  Hrst  rise  also,  but  it  \%  more 
protMible  that  so  oiarketl  and  sudden  a  rise  as  this  is  carrieil  <iut  by  M>me 
MTVoua  raecbaniHm.  The  details  of  this  raeofaaiuBm  have,  however,  not  m 
y«t  been  aatitfoetorily  worked  out. 

Tbe  pAncrea*  derires  ita  nerves,  which  reach  it  along  its  bloodvtMeli,  friMn' 
tbe  K>liir  plcxut  »f  the  nplanchuic  ayelem,  but  tl»e  ultimate;  origins  of  the 
flbra  have  not  been  imccd  out ;  auroe  of  llieni,  however,  oortainly  ooiM 
tbrMgh  tbe  plextt*  fttim  the  right  vagus. 

Stinulalion  of  tbe  m«<lulla  obloa^la,  or  of  tlie  spinal  cord,  will  call  fbrtll j 
wcratiun   in  a  ijaiMcont  gland,  or  tnercaiw  a  »ecret)on  alreiuly  gi>ing  OB.J 
Prom  thb  we  may  infer  lli>'  oxiolciice  of  a  reflex  tncchaniam.  though  wa 
onant  as  yet  imx  out  aatixfaetorily  the  exact  path  of  oitJier  the  aderent  or 


360        THK   TlSSt^ES    AMI    UECHAXISMS    Or    UI088TIOS'. 


the  eflervut  impulses ;  all  we  cnn  say  is,  that  Uie  latter  do  not  reach  the  pan 
creaa  by  the  vagus,  since  stimulation  of  the  medulla  is  effective  after  :)«c(ion 
of  both  vagi. 

Pn.112. 


S 


z:; 


^ 


;gl3H|S|6|7la|9llO;itll2!l3lt4llM'6lll^l3l4l5l6i?l8i9[l0 


OutitAH  iLLiBTacnNu  TMK  l^pML^ts^T  or  I'ooii  □!■  tuE  SeuitTioji  or  Paxouttc  Jc 

IN.  u.  BunmiN.) 

'niB»l»otn»  rBpHtlilbnurTnHtfrmilnj;  Ibnd;  Ihe  oidliiaiM  irfimenl  In  e  n.  Uio  aiiwont  or  ■ 
UoD  In  Ion  minulci.  A  markiMl  riic  li  Hvn  bI  B  linmgdlaulr  nRct  Ibul  hu  Ukcn.  wiUi  a  i 
im  hflBiyiillhu  founli  niul  tinh  linun  iiftvFHinli.  W'hnv  Ills  llnv  U  i1i>ll(>]  Itia  otmtrmHon  ■* 
Inletmiilcd.  tin  fno4  Mug  nmin  rItdii  al  i~.  ■noincr  rite  U  foca.  fnllowcd  In  tiltn  br  ■  i1li|ii  ii^iw 
and  m  wmnilu)  rlw  m  tht-  nnii  liaiK.    A  rory  liinUar  ciirvu  waiilcl  n>|iramit  ilin  Mervdnn  tt  tot. 

A  Kcrvtion  alreiiily  going  ou  may  be  KrrcMcd  by  stiiniilstioD  ol'  tJte  ceti- 
trnl  cikI  of  the  viigun,  and  Ilio  «loppngc  of  the  x-cnaioii,  which  haj  b«en 
ohM-rvcil  ail  nccurrinc  during  and  nttcr  vomiting,  iv  prolmbly  brought  about 
in  lhi«  way.  Thin  ftlWi.  whirh,  howcvor.  ii  not  roRfinwl  to  the  Tajfus,  gtiniu- 
lalion  nf  i>ihcr  atR-rent  nerTct>.  «uch  at  thtr  eciatic,  producing  the  nme  efl^t, 
may  bo  regarded  (in  th«  alMciiee  of  any  proof  thai  the  result  is  due  to  reflex 
oonstriclionof  tbopuioreatic  bloodvemeels  unduly  choking  the  blood-supply) 
M  an  inhibition  of  a  reflex  lUGrbanifm  al  ils  centre  iu  the  medulla,  or  in 
wnne  other  part  of  the  ceulml  nervous  system,  much  in  the  same  wny  u 
ftsr  inhibiu  al  the  central  nervous  syslem  the  secretion  of  saliva  following 
food  iu  the  mouth,  S,  ^2ti.  Bui  if  so,  then  we  must  regard  the  secretion  o? 
pancreatic  juice  as  closely  resembling  thalof  salivii  Id  as  much  as  it  is  wiled 
foitb  by  a  rcllex  act.  Yet  it  is  Hlaletl  that,  unlike  the  ciisc  of  Miliva,  the 
secretion  of  pancreatic  Juice  eontinuts  after  all  the  nerves  ^oing  to  the  gland 
bave  been  divided,  an  openilion  which  would  do  anay  with  the  piMMbility 
of  reflex  action.  Kuch  an  cxtifriDienl,  however,  cannot  he  n.-ganli-<l  ax  de- 
cisive, since  it  is  almost  im]H)mildt!  to  be  sure  of  dividing  all  thi^  ncrvm. 

No  evidence  has  yet  luxa  brought  forwnnl  to  j)rove  the  uxiftcncic  of  tiny 
double  nervous  mechanism  nmilar  to  that  of  chorda  fibrts  and  tympatJielic 
fibre*  In  the  saliviirv  gland.  All  that  can  l>e  Hud  is  that,  whi-n  thv  gland  is 
stimultitt^  to  .-^crete,  the  blootlvcMQls  ar«  dilated  as  in  tlie  salivnrv  glaod; 
and  wo  have  already,  §  2^9.  dwelt  on  the  hislolugicjil  changw  wbicn  accora- 
pnny  accretion.  Vt  c  mny  add  ihai  when  the  gland  is  otiniulated  U)  incroaed 
secretion,  the  increase  is  not  nieroly  an  increase  of  water,  llie  discharge  of 


SKOKBTION   or    PANCREATIC  JUICE   AND  OP    MILK       331 

wMda  If  inercMMl  fives  mttn  than  tbe  diachKrge  of  water,  so  tbat  th«  pe^^ 
tmt»0r  of  tolids  in  the  juice  iiicrensea. 

TIm  iiiMiilitjr  of  paDCTMtio  juice  eecreied,  in  the  case  of  man,  in  twenty- 
knr  hoan  hna  been  eiOeulated  at  WO  cc,  but  such  a  culcninlion  is  of  verf 
Mcgitain  valiK. 

%Vr  Invc  Been,  $  '227,  tliat  in  tbe  snlivarr  inlands  lli«  pressure,  nhiolt  may 

W  mxttutl  bv  the  fluid  in  the  duot».  is  very  considerable,  exceeding  it  nmy 

fc«  •Ten  the  biood-prwaure  in  the  carotid  arwry.     In  this  respect  tlm  pwi- 

tftmm^&n  from   the  salivary  glandH.     When,  In  a  nd)bit,  a  eauula   iwt- 

■McCvd  with  a  vertical  tube  or  a  nianonierer  la  |ilat«<l  iu  the  puucrealic  duel. 

*^    ColuiDD  of  fluid  doe*  not  r\m>  alxivi-  ii  beitint  correapondinif  to  a  ptCHura 

>>(   aklMMii  17  nm.  of  mercurv.     But  al  lbi»  pruMture  tbe  Riand  becoin«a  oAe- 

iMftt^Hu  on  account  of  the  Juioc  wcrded  ptuaing  buck  tbniugh  tbe  walls  nf 

**^    dnota  and  alveoli  into  tho  conncctiro  tiamic;  a  much  higher  praMure  is 

■^•airf  to  raider  a  nlivnrv  jrfnnd  ind«mntou* :  niid  whether  the  low  pmaure 

'^"•ajiwl  In  the  pancTOU  i»  due  to  the  en*c  with  which  micnm  takes  (ilnce,  or 

**     *.  Ill-  actual  wcrvtion  not   being  able  Id  reach  a  higher  |in»»iire.  cannot  be 

•*^*«il  with  certainty. 

S»  US.  Thr  Koriion  of  biU.  Tho  act  of  eecrotioo  of  bile  bv  the  liver, 
*?  ^^M  nol  be  conlbaiidcd  with  llie  disL-hargc  of  bil«  from  tho  bil«  duct  into 
^^duodaaum.  When  the  acid  contenls  ul  the  rtonmch  art-  |H>ureil  over  the 
'^T^^  lire  of  the  btltsry  duct,  a  gush  of  bite  takes  place  Indeed,  titimulation 
tkL  ''*'*  '*?*''*'  °^  *^  dno<lenun)  with  a  delule  acid  al  onoe  calls  forth  n  flow, 
^^«ugfa  alkaline  fluid*  ao  applied  have  little  or  do  etfect.  Wlicn  no  Rich 
^_^?id  fluid  ia  paMiug  into  the  doudenuni  no  bile  in,  under  normal  oirciim- 
^^VMMt  diaobarxed  into  the  intestine-  The  diBi.'liur>>e  is  due  to  a  contraction 
^Y  ibe  muacular  walls  uf  tht^  K""-bladder  and  duc-tii,  accompanied  by  ■  ro- 
'^^tation  of  the  ^tphlnvter  of  the  iirillct.-;  both  acta  are  probably  of  a  reflex 
*^siun-,  but  the  detail*  of  the  me<.-bgint»in  have  not  been  workol  out. 

Tbe  M-crttinn  of  bile,  on  the  other  band,  as  ohowii  by  the  rcautta  of  biliary 

^atnUe,  i»  continuouit ;  it  nppenra  never  to  wa»c.     When  no  food  ia  Utkeii  ibe 

\aHn  p«Mn  fr<>m  the  bver  along  iht:  hcpalir  and  then  back  along  tbe  cyatio 

«3act  (the  flow  being  aided  pr<tbnblr  by  peristidlic  <«ntniction»  of  the  niu»- 

«alar  fihres  of  tbe  duct)  to  the  gnll-bliidder,  where  it  i»  tem|K»nitily  *(»re>l; 

kcoca  in  alarving  animaK  when  no  diH'hari>c  is  excited  by  fixid,  the  gall- 

tilsdfltr   bccumcs   greatly  dinlcndcd  with   bile.     Itut  the  Kccrctiou,  though 

oootioiiaiM,  ii  not  unilorni.     Tbe  rate  of  secretion  varies,  and  in  ivfiecialty 

■afloeon-d  by  food  ;  il  is  seen  to  rise  ramdly  after  meats,  rraohing  itJ>  maximum. 

tBiloga,infromfourtoeii;hl  hours.     There  eecma  to  bo  an  immediate, sud^len 

riw  when  food  is  taken,  then  a  fall,  followed  Bubse<)uentlT  by  a  more  gradual 

rlw  up  to  the  maximum,  and  ending  in  a  final  fall  to  the  lon-cnl  ]>ninl.     The 

enrvig  iif  teeretion,  in  fact,  reoemblea  that  of  the  secretion  of  jmncrcatic  juioe 

in  having  ■  double  rise ;  and  as  in  that  eaae  ao  in  this,  it  is  venr  praMhle 

that  tbeflratriK  ta  in  part  the  reHult  of  nervout  action,  and  it  is  also  pomble 

that  nervous  influencee  i»len,-ene  in  the  aetiMid.  more  laaling  rise :  but,  a»  w« 

■hall  !we  prcaently,  even  oerAoaa  influeiieea  may  aflect  tlte  liver  in  a  very 

indirect  mnuner,  and  our  knowledge  ns  to  any  direct  action  of  the  nervous 

•yvtem  un  the  liver  la  at  preaent  very  iniperfeet. 

The  liver  teceive*  il«  chief  nervouw  nupply  from  the  aniar  plexus,  and  to  a 
^H  pmt  extent  throu^  that  part  of  the  totar  plesun  called  the  hepatic  plexus, 
^B  whjieh  enbncea  iho  portal  vein.  be|uitic  nrti^,  ami  bile  duct,  an  tfaeee  plutige 
^H  into  tho  liver  at  the  ]>oTta.  The  M>lnr  plexun  if  feil  hy  the  lw(>  abiloniinal 
^H  fpUochnic  norvm,  nnunr  nixt  niinrir,  by  <ilbur  »niallor  nervea  fri>tH  the  lower 
^^  parta  "f  tlie  >|ilanchnic  (aympatlHlic)  chain,  and  by  tlw  tcrmitmt  jmrtion  of 
ibi  right  vagua  nerve,    timul  bnncbca  from  tlie  ieft  vagus,  mnn  hcfiatici, 


I 


a 


I 


THK  TISSUES   AVT)    XBCnA^CISltS  OP  DIOKSTIO.v. 


>lao  pius  directly  In  rh«  lirer  froin  ibe  leriniuatiom  of  (hat  nerve  on  tbe 
ttomnch,  fiudioc  ilieir  way  aUu  Lhrougli  cbe  (torta.  The  ftbrea  thus  enteriD|r 
Ui«  liv«r  from  the  several  mourmh  are,  for  the  aum  lurl,  non-meiliillniMi 
fibr«a;  with  these,  however,  are  nixed  a  certain  number  of  roedallalod  fibres. 

As  to  the  funutitim  of  iheM  uerve*  iti  n-rereiic«  to  (he  aevmion  of  bJle. 
n e  mar  say  nt  once  (bat  no  «Hti»ractorj  or  cxu-i  outemt^nt  can  at  prewnt  ba 
luailf. 

$  2&4.  It  muitl  be  ruinumbered,  however,  tlutt  the  liver  Is  »>  i)ecullarlr 
reluti^d  to  th«  other  orgaiwof  digmtioo,  and  its  va»cular  arntii^ii>cnt«  w 
api^ciul  that,  with  rmrd  to  it.  as  compared  with  mauy  other  organs,  an 
inl  rinHii;  iiervoua  mechaniam  must  occupy  n  more  or  km  subordinate  poriliun. 
Th4-  blood-supply  of  the  pnucrens  for  inatniice  is  dependent  chieAr  on  tho 
width  for  the  time  beiu);;  of  tbe  pancreatic  arlerie«;  it  will  be  afiecled,  ol 
eouiao.  by  the  ^neml  arterial  jirra^ure  and  by  any  circumstances  whicl 
tflbot  the  outflow  by  th«  pancreatic  veitis,  and  therefore  by  the  condition  01 
the  portal  venous  system  of  which  th(«e  veina  form  a  part ;  hut  iu  the  main, 
the  amount  of  btood  bathiiif;  the  alveoli  of  the  pancreas  will  depend  on 
vrliether  the  pancreatic  arteriat  are  coii^lricted  or  dilated.  The  quality  of 
the  blood  reaching  the  iwncrea*.  being  arterial  blood  drawn  direct  IVom  the 
arterial  foundation,  will  \te  mtKlilied  only  by  «uch  cirenmstances  as  modify 
tite  eeneral  ma«  of  the  blood. 

Very  dilTeruit  iti  the  ca»«  of  the  liver.  The  fiipply  of  arterial  b) 
comtni;  direct  through  the  hepatic  n^t^^^y  is  small  compar^-d  with  the  n» 
jtourinji  tbrougli  the  vttna  pfirtie  ;  it  moreover,  as  we  shall  see,  i*  dirtribut 
in  capillaries  among  the  small  ioterlohiilnr  branches  of  the  vena  portie  ai 
haa  beoome  ve:iouK,  indeed  mcrgvd  with  tho  portiil  blood,  befbra  it  reaol 
the  artunl  lobules.  Tboaupply  of  blood  for  the  liver  i*  mainly  that  (hn>n|r' 
tht-  v<inH  [lortic;  and  this  supply  is  not,  like  an  arterial  supply,  ii  fiuny 
uniform  our.  ntodilied  chieSy  by  tlie  vasomotor  events  of  the  orgnn  itfM-lf, 
hut  in  de|K-ndent  on  what  happeoa  to  be  taking  place  in  the  alimentary  ennal 
and  in  abdominal  organs  other  than  the  liver  itself.  When  no  food  ie  hv'mii 
dig<!H(ed  and  (be  alimentary  oanal  is  at  rest,  the  reaaels  of  that  canal,  nx  we 
have  already  said  in  speaking  of  the  stomach,  are  like  those  of  the  paiicroiw 
and  salivary  glands,  in  a  stale  of  tonic  constriction ;  a  relatively  small 
(juantily  of  blood  paasea  through  tliem :  hence  the  How  thn>ugh  the  vena 
Dortffi  is  reUttively  (Dcoiwiderable,  and  the  pretaure  in  llial  vessel  is  low, 
When  digestion  is  going  on  all  the  minute  arteries  of  the  stomach,  intesliD< 
»pleen  and  iwiicretn  are  dilated,  and  geiicral  arterial  preMure  being  bv  sooil 
meaiu  or  ulhiT  maintained  <»w-  i  I9i),  a  relatively  large  quantity  ot  blond 
rushes  inUi  tlxi  vena  portte  and  the  pressurv  in  that  vewel  l>Momea  mueh 
increaHcrd,  lliongh  of  courw  remaining  tower  than  the  g<eiM^r)kl  arterial  ptea- 
sure.  Moreover  during  digestion,  peristaltic  mnvi-oMnts  of  tho  muacnbir 
ooata  of  tho  alimentair  canal  are.  as  we  have  «i.-«ii.  active ;  and  theee  oun'e- 
mentfl,  serving  us  aids  to  the  circulation  (see  §  Til),  help  to  incrauo  the 
portal  flow.  Further,  the  spleen,  as  we  shall  »ee  in  epuaking  of  that  organ, 
ii  in  CDOny  animals  richly  provided  with  plain  mii«cutar  fibres,  and  in  saeh 
CMW  HOOnis,  especially  during  digestion,  to  act  as  a  muscular  pump  driving 
the  blood  onward,  viih  lucrensed  vigor,  along  the  splenic  veins  to  tbe  liver. 
So  that  even  were  tbe  liver  not  ooni>e«ted  with  the  central  nervous  rretent  by 
It  single  nervoti!)  tie,  the  tide  of  blood  through  the  lirer  would  ebb  and  flow 
Mcording  to  tbe  absence  or  preeence  of  ftK>d  in  tbe  aliinentxry  oanal. 

An  incresne  of  bl<iod-»iipply  does  not  of  course  neoeasarily  mean  an 
iocmse  of  secretory  activity.  As  we  have  seen,  §  327,  in  the  preuence  of 
aln>|Hoe.  the  secretion  of  nliva  may  stand  Mtill  in  ipite  of  diUted  bluod- 
vevela  and  the  consequent  niali  of  blood ;  but  we  may  safely  aiueri  that. 


I 


okriUag*  bring  equsl.  ii  fuller  bIn<Ml-«upj>l}-  »  IkvornbU)  to  nctivity.  Ap- 
pnallf  ■  mwr*  cbiw)^  in  thu  qiiuntilv  ol  nlmKl  bathing  ma  alvmii*  will 
Miaui  Is  tfa«  odU  tbc  ohanK«*  urhidi  comiitiite  the  act  of  sovretion,  anj 
Mnihan  aa  tncttaM  in  the  bliwd  bathing  a  muKCiilar  fibre  will  noocmirity 
Mmaic  n  coiilractidn  :  liul  iintma  tUorc  bn  ttoniccminUT-iictiiig  infliu'iicc  at 
ntLa  tullrr  uid  rirbcr  lymph  Hriiiiinl  it  cn-M  wilt  niitiiritlly  W'l  to  ihr  ex*)! 
likiqg  up  iDdriK  nHMrial  fmni  thv  lymph,  iiiid  »»  will  in(Tcii>o  t\n-  ccll'ii  «lon- 
^mtfj.  HcDM, Mpaeially  in  thv  hvpntic  cell,  which  Hpp(mr»  lo  be  nlwnys 
Mnrii.alwav*  tinilrrgoing  mHaboliim  of  iiiich  n  kind  a*  to  givr  rtim  !<■  bile, 
■t  nit^t  liiirly  expect  the  greater  flow  through  th«  portal  v«in  to  quicken 
iJhrmw  through  (ho  bilo  <)uct. 

Aai)  at  a  ninltcr  of  lact  we  do  Bnd  vaao-conetriclor  action  dominant  orer 
licBForvtinn  In  (be  varioui  experiments  which  have  boen  nmde  to  Rsecrtain 
ifae  arliikD  of  the  nervou«  system  on  the  secretion  of  hile,  it  luis  always  been 
fnuiMl  (liat  rtimiilB(ion  of  the  metlulla  obloogata,  or  of  the  spinal  cord,  or  of 
tJi«  abdamioal  splanchnic  nerves,  bIods  or  at  least  checks  the  flow  of  bile. 
XtTW  tlic  eflect  of  these  slimulatioae  W,  aa  ««  have  already  seen  more  than 
ooc«.  a  powerful  cnnstriciinc  action  on  the  abdominal  bloodveesels  ;  by  such 
AiiDuUtion  (Jie  blood-supply  of  (he  liver  is  materially  diminished,  and  in 
eDU«n|iivtice  tbe  aacretory  acurity  i»  slackened  or  arrested. 

Ilut  iht^re  It  something  bcaidea  the  nwre  quuiiuiy  of  blood  to  be  oonudered 
la  ikia  relalMMi.  The  bloml  which  poasea  mim  tlie  alimenlHry  cunal  at  rest 
ia  vtSoBTj  vanout  blood,  laden  timply  wiili  cnrbimic  ucid  and  the  onlinarv 
pradoMiaf  the  metabolism  of  the  iiiu.->cular  and  iiiucouh  couts  of  (he  canal. 
wImb  dEmtien  b  going  on  (ho  purlul  IiIimhI  i.-<  ]udL>n,  ua  we  «hall  h«,  with 
tntut  at  all  evcnla  oTlhe  produce  of  dig«>iii>n.  with  lugar  probably  and  wiih 
VkfioM  nfotcld  bodiea.  And  il  ih  ijuiie  puwlhle  (»r  even  probable  that  some 
of  then  Dodica  in  tbe  portal  blood  reachiog  th«  hepatic  cells  stir  ibem  u]>  lo 
■acnton*  activity ;  indeed  this  view  maybe  regarded  as  supported  hy  the 
beta  that  protetd  Iwd  increased  the  (|uantity  of  bile  secrolcd,  wheniis  its 
fitlty  feud,  which  as  wc  »hall  see  passes,  chiefly  if  not  whoUv,  not  by  tbtt 
noiul  vein  hut  by  (he  lymphatics,  and  which  is  probably  larveiy  dispoml  of 
m  Mne  way  or  o(her  before  il  can  reach  (he  liver,  hns  no  such  etfecl. 

Heooa  we  may  infer  that  at  nil  events  the  second  increase  of  the  flow  of 
bil«  which  oocan  during  the  la(er  stages  of  digestion  may  be  to  a  large 
aait4:n(  (be  direct  eflbct  of  blood,  laden  with  digeatire  products,  pasaing  from 
t  stomach  and  tDtestinea,  especially  the  latter,  to  tbe  liver  by  tbe  portal 
Bh,  quite  iudepeudeat  of  any  direct  nervous  action  on  tbe  liver  itaelf :  nud 
\oAt*a  It  is  fjiB9thle  chat  the  first  ri.w  also  may  be  partly  due  lo  tlie  increased 
flow  of  blood  I'rum  tbu  stoiniu-h,  aidud  by  (be  abwrptiou  from  that  ot^nn  of 
k  cartaln  aaaoant  of  diicuile<l  nmterial.  Since,  honerer,  there  la  no  evidence 
uf  any  decrease  in  blu(Hi'jiiip[ily,  or  :u  thif  rate  of  abaorptlon,  oorrespondtog 
U>  the  fall  b<-tween  the  twu  hms  miiih-  luduences  otlier  tlinu  those  which  «re 
are  discusung  must  lie  ut  wurk  in  the  matter. 

(  SC6i  Tbe  blood-supply  of  the  liver  beang  thus,  cjulle  apart  from  any 
Btrmas  supply  of  its  i>»n.  ao  cloesly  dependent  an  what  Lt  going  on  iu  tlw 
■lisWBtsry  canal,  it  will  be  coavenivnt  t»  *av  a  few  w»nii  more  connrnlDg 
ifae  nMoootor  nerves  of  that  canal.  As  wc  liave  alrcaily  i>ui<l  in  speaking  of 
iba  rascatar  system,  S  1*>9.  the  vns»-constrictor  tibm  lor  the  sloniach  anil 
iutertinsi,  large  and  small,  imuing  from  whut  we  mav  call  the  vaMCon- 
ttrictiir  regioo  of  ihv  mril  (Hun  for  the  most  part  throtigb  tho  two  ab<l»minal 
mlaocfaoic  nerves,  major  and  minor,  n  small  numU'r  only  passing  nut  below 
Uke  roots  of  those  nerves.     When   tlicw  aplancbnir  nerves  arc  dividnl  the 

Eof  U>e  cnnal  are  dilaKnl,  when  they  are  conirifugalty  stimulatiM  tho 
■re  oonelrieted.     \Vhc4her  there  l>e  any  distinct  vuso-^lilator  fibrM  fiir 


364      THE  Tissusa  and  mkcmanisms  op  DIOKBTIO.V. 


all  iir  any  imrl.  uf  the  citnal,  nnd  if  oo  whnl  course  llicy  take,  u  iwt  knnvo. 
Wlici)  iii>  itxiH  hug  fur  sonic  titno  been  taken,  (he  mucous  membrane  of  the 
stonmch  ns  Mftn  Ihrough  n  giLetric  listula  is.  p»lo :  the  blotHlrmsfIa  are  ooo- 
Slrii;lc<l.  Am)  ni  for  iis  vc  know  a  simitar  condition  oblniDS  Lbrougbout  ibt 
IIDbII  nnd  liirgv  intestines.  When  food  is  taken  the  mucous  membraiK  of 
the  stomnch  becomes  dtished  :  its  vessels  become  dilated.  This  nppcan  In 
1)0  the  result  of  an  inhibition  of  the  previously  existing  tonic  constHclioD; 
at  least  we  have  no  evidence  sujiporting  any  other  expltmatioo.  Appareiitlj 
ihe  presence  of  food  in  the  stomach  starts  in  the  mucoue  membraoe  iDRuenoea 
which,  ascending  to  the  central  nenous  system,  inhibit  llie  vasomotor  centre 
for  the  abdominal  splanchnic  nerves  or  such  part  of  that  centre  as  unrerns 
the  vaso-constrictor  fibres  of  the  stomach.  !iy  wliat  path  such  aflereiit  iin- 
pul!>ea  reach  the  central  ner%'«u»  srslcni  i»  nut  oa  yet  defiuiiialy  settles) ;  but 
poeMhIy  by  the  vagus  nerve,  if  it  tie  true,  as  slatird,  that  ceiiirijielal  stiuii- 
laijon  of  that  nerve,  vrhile  it  raises  the  jct^iieral  blucid-jireiHure  by  iiicreaiing, 
in  a  retle;if  tiianner,  VHso-constncliou  in  other  regionf.  IcaiU  to  a  dilatation  of 
the  K<>^tr!c  vesaeU.  80  alwi  it  in  probable  that  a*  the  food  n-ache*  succeeding 
secliiinit  of  the  alimontnrv  canitl,  thcw  in  turn  in  a  similnr  manner  liccome 
flunht^d  with  htiHid.  In  ilic  frog  (bent  is  some  cvidonct>  tbnl  vai«>-coniitrictun 
leavruji:  the  »|>iiial  cord  bv  consecutive  spinal  nerves,  govern  the  bloodvotwl* 
of  coUMculivi'  M-cliiins  ol  the  alimentary  cniial. 

All  thi^i  Hushing  of  the  canal  with  blood  lend*,  wc  repeat,  to  an  incn-a^cd 
flow  of  blood  nt  aliijrher  pressure  through  the  portal  vein.  Whether  besides 
there  bo  any  additional  mecbnnism  set  to  work,  such  as,  for  in»tance.  which 
tome  ohmrvations  suggtst.  u  rhythniiciil  peristaltic  contraction  of  the  portal 
rein,  l>y  which  the  blood  is  siill  more  rapidly  hurried  to  the  liver,  and 
whether  the  increased  venous  supply  through  the  portal  vein  is  a^icompanied 
by  a  eorrespoDding  increase  of  tne  lesaer  supply  of  arterial  binod  tlirough 
the  hepatic  artery,  is  not  known.  It  may  |>erham  be  here  remarked  thai 
that  there  is  no  need  for  anv  iiicreii«e  of  nrlerial  blood,  since  the  blood  fW>ru 


Ihe  alitnentarv  oanul,  owiufc  to  its  more  rapid  pi^^  through  the  minute 

probably  like  the  oorrenix 
uilivary  glaml  1  though  probably  aluo  not  to  ihi;  tame  oxtciil)  leoH  veiioua 


veMcl-<.  v  probably  like  the  oorrenixinding  blocHl  in  the  veins  of  an  active 


than  U!<aal  during  digiwlion  in  spite  of  (he  extra  i]uaj)ti(y  of  carbonic  acid 
thniivn  into  it  hy  the  increased  melaholisni  of  Uic  muscular  coat  during  thi.i 
|ierb>tallic  muvemeiits. 

^  259.  It  is  interesting  to  observe  that  ihe  pre^wure  under  which  the  hite 
Is  »ecruiwi  is  rclativelv  low  like  thnt  of  Ihe  pancreatic  juice,  not  high  like 
that  of  (Jic  taliva :  it  is  much  lower  (han  the  arterial  prcMure  in  the  name 
animal,  whereas  in  the  case  of  saliva  (§  '227)  the  prvMure  is  greater  than  the 
blood- prcMu  re  in  tlie  carotid  artery.  But,  in  the  caw  of  bile,  since  the  blood 
whioh  flows  throngh  the  hepatic  lobules  is,  mainly,  venous  iwrtal  blood,  vrc 
have  to  compare  tne  pronnre  of  the  secretion  not  with  arterial  preasuro  bat 
with  the  venous  prcaure  in  the  portal  system  ;  and  in  the  dng  it  hu  been 
found  that  while  the  prrasure  of  the  bile  secreted  stood  at  about  21)0  mm.  of 
a  eolutioD  of  sodium  carbonate — that  is,  about  lu  mm.  mercury,  the  blood- 
pnoure  in  a  branch  of  the  superior  mesemeric  vein  stood  only  at  about  90 
mm.  of  the  Mme  eolutjon — that  is,  about  7  mm.  mercury.  Now.  the  venous 
preraure  in  the  mewnlenc  vniit  is  higher,  though  only  slightly  higher,  than 
that  in  the  portal  vein  into  which  these  pour  ibeir  blood  (the  dilferem^  of 
pressure  being  the  main  cnusc  why  the  blood  flows  from  the  one  inbi  the 
other),  sud  In.  thvrel'ore,  ecrtainly  higher  (hnii  the  pmsure  in  the  i>orliil 
capillaries  of  the  hetiutic  lohuhs.  ."vi  that  what  is  true  of  the  salivary  gland 
is  also  tn>e,  on  a  diH<;renl  «cale,  of  the  liver,  vix„  thai  the  ptewure  exerted 


^ 


IN'I'UKTlNKl). 


r  lbs  Hontion  is  h^^ber  than  the  pre«nre  of  the  bloo))  in  tbo  wnels  fMing 

m  »ttavX\aa  eelU. 

f  907.  Ifitie  presHire  in  the  bil«-duct  bo  nrlilici.itiy  incrcnsed,  ns  by  poiir- 
}t>g  tlui'l  iiili>  the  fiifHB  tube  or  tuaiionwter  with  which  the  caiiiila  io  the  ilucl 
it  nmttectt*),  a  ivtu>rptiofi  of  the  wcrelecl  bile  takee  pItu.'L- ;  and  resorption 
«ill  «bo  tnke  plftcv  wilhii)  the  body,  wheu  the  preuiire  s«Qerated  by  the  act 
rf»«mti"ii  iUelf  reacha  and  h  luaiutaiiied  nt  ii  -luifii-leDtTy  bigli  lev«l.  Thtn, 
«1mii  in  iii«  liviog  body  the  bile-du(.'t  h  ligatureil,  ur  becomee  obitruc-ted  by 
KaU-aUxna  or  Uh«r»iw,  fluid  is  ot^cumulated  on  the  ueur  Bi<le  of  ihi-  ligature 
at  a  prwure  which  foea  on  iocretising  until  rotorption  of  bile  takea  phn, 
bite  Mit*  and  biliary  piKinent-i  are  rhrovru  tiacic  ufoii  Uie  ■r9t«tit,nnd  "jniin- 
iita"  n^ulu.  It  nouM  ap[>ear  thut  in  thcsie  eauea  mMrplioii  take*  placv 
tfaroagh  the  intrrlobulnr  tiileHJucta  aiid  nut  tlinnixh  ibe  hepatic  celbor  otlMir 
•tractam  within  the  lobultu^  Th*<  high  prvavure  in  the  duct*  ijoex  nut  lead 
U>  ■  rtvana)  of  tk'  current  in  tbo  hepatic  oc1l«  Tat  in«sl  it  dacken*  or  \xi$4- 
Ujr  ttOM  th«  currrnt)  but  ihv  bile  tecreted  into  the  iatu-lobular  dnuU  wca])« 
ftDn  tttMD.  It  further  ap|)car«  that  the  eerajM;  in  noL  into  the  hloo<)v«neU 
Irnt  into  the  lymphnlic*;  the  bili?  (alt*,  pignicnt*,  and  other  conRtiiiiciit*  ant 
otftied  iiitu  tlx-  thonu'tc  duct,  mid  in  an  indirect  nmniier  only  find  their  way 
iDio  th«  blood  itreaiii. 

To  oomplete  th«  history  of  the  »ocrction  of  bile  we  oiieht  now  to  ttirn  to 
the  maout'acturc  of  the  biliary  'onstitiicnli  within  the  cello.  Ilut  einoe  the 
hefiatic  cells  are  alM>  cnffnged  in  Inliora  other  nnd  uuitc  important,  perhaps, 
Umn  that  of  t«erc4tDg  biFo,  it  will  be  convenient  to  defer  what  we  have  to  say 
oa  tbu  point  until  we  come  to  epeak  of  tbo  formation  of  glycogen  aod  of  the 
gtmml  roetabolio  e%-«it»  taking  place  io  th«  livw, 

TbS  f»TRUtTURK  OF  THE   IntEBTINES. 
Thf  SitulU  Jnhatine. 

I  SM.  The  intesline,  small  and  large,  throughout  ita  length  from  U 
pylonu  to  cloae  opiHi  tlie  reetuio,  follows  in  it£  structure  the  general  plan 
piwionair  doeribed,  S  '^OH.  A  thin  outer  loni^itudinal  muscular  layer, 
eoreml  by  prTitoaeaiii,  is  succeeded  by  a  thicker  inner  ciruubir  muwulnr 
layer,  and  thia  double  nuacular  coat  is  separated  by  a  eiibniuooua  layer  of 
loaat  eonaective  timie  carrying  the  larger  bloodveBBels,  froni  tbe  niuooun 
liMlwhriiii  which  eoDsista  of  au  e|ii[heliuni  lyiltK  upon  a  eonnective-ti^MiC 
buit  of  peculiar  nature.  »  u  elide  veli>[>e<l  mu^cularis  niueosie  of  luugitudioal 
•ml  eircular  HbrM  marking  uti'  the  luucoui  membrane  proper  from  the  under- 
lying >ubtiiui-ooii  ti»ue- 

In  the  uuall  iutt»tine  llw  outer  longiludinul  inu^ular  layer  it  evenly  dis* 
tribnlcd  orer  iho  whole  eireumfereiice  of  the  tube  and  ia  everywhere  mnob 
ifainoir  than  lh<>  inner  circular  layer,  which  U  tbe  mor«  iiugmrtant  layer  of 
At  two.  Tbe  indivklual  Ghre-ccllii  of  these  muM-ular  layern  of  the  inleslino 
ai*  large  and  well-drwioped.  lu  tbe  thin  Kheet  of  connective  Ua>u«  which 
•ejianues  indistinctly  the  two  layer*  li«i  Ibe  plexus  of  Auerbach,  a  plexus  of 
iMrT*-fibres,  for  tlte  uK»t  prl  non  nxidullai^^l,  iit  the  nodes  nf  which  are 
KBtbend  groups  of  very  >mall  nerv^cvlls,  ihe  sulwtnnce  of  each  cdl  being 
eapecially  scanty.  This  plexo*  »up]di(M  the  two  rausrular  tnycni  with  nerve- 
flbns. 

The  fubfOUCHis  cml  cimlJiiix,  bnides  hloodvaiMit  and  lymphalioi,  u  #»me- 
wbal  nmilar  plexu»of  iicrve-liliree,  calle<l  the  plexuK  of  MtiMiier  [Fie.  113]: 
A>aai  this  plexiw  line  nervi-Kbtm  pnicred  to  tbe  blootlvvwels,  to  the  mils' 
'  I  inuoMK,  and  possibly  Ui  uthcr  rtrudurce. 


I 
I 


366        TlIK    TIBSt'KS    ANP    KKCnANISHS   OF    DI0K8TI0N. 

^  SAO.   Tlic  mneoHt  meml/rriHe,    Tbiii  is  tlirown  iuUi  folda  wlileb  ant  tiot,  u 
ill  the  oue  of  ibe  stomacli,  tenipornrj'  loiif(ilutliQKl  foldA,  rujw,  but  pnrnia- 

IPm-iii. 


^r- 


Ifuxw  or  tinvMia  nMui  nt*  tWsKVOoiv  Omt  iw  m*  timwnMi.  |Carui.}| 

nent  trtnerene  fbl<b,  the  ratniltr  emtnivmbv,  raichliiE  hKlf-wfty  6r  twu-ibirds 
i>r  the  way  rwutid  tho  tube.     Kach  fol'l  u  n  fold  of  ln«  whole  mticouM  mem- 
bnne  cnrrying  wilh  it  «  part  of  tbe  tmbmueous  liw«ie, 
inu.  iw  ||,e  liillor  tluiit  furniing  it  miHillc  nbwl  bctwwu  ihc  mu- 

cous mcmbniiic  uii  tbc  iipjwr  mirrHon  an<l  tluii  on  the 
lower  Hurfncc  of  thi:  fo!iI.  The  fi)l<K  wliiih  viiry  in 
eiu?,  large  aixl  einsll  fn->:|iicntly  alccruntoly,  Itcgin  to 
appear  at  a  little  ili^ttinoG  from  the  pyloruH;  (bey  are 
especially  well  developed  just  below  tbe  ojKDiof;  of  the 
bile  and  pancreatic  diictfi.  and  are  coiitiuue<I  down  to 
about  tbe  middle  of  the  ileum,  where,  becoming  aoialler 
and  trreguUr,  they  )t<^diial1y  disnppear.  They  aerve 
to  increase  the  inner  surfaoe  of  the  intcaline  and  preeent 
an  obaUcle  to  tbe  too  rapid  transit  of  material  along 
the  tube. 

Orer  and  above  tbe  ooaraer  inequalities  of  surfoce 
caused  by  these  foUU.  tbe  level  of  tlie  mucous  mem- 
brane ia  broken  on  tlie  one  hand  hr  to»];ue-like  pro- 
A  014SU  ur  utDU'      jectiuns,  the  t-i//i,  and  on  the  other  baud  hr  tubular 
■■.'■Hi  dcpreniooB,  tbe  ;/laHtlt  or  erypU  of  LifbtrkHin.    [Pig. 

114.J  Tlic  latter  arv  vi-ry  mnrh  sunaller  and  aro  more 
numcroiu  than  the  former,  neventl  cryixa  iw'mg  placed  in  the  Interval 
between  two  villi.     Both  are  found  Oiii  tho  pi^emng  valvulie  at  well  ws  in 


^ 


Tils   STBCCTl'Itli    or    TlIK    INTESTINES. 


367 


I 


tbf  raUr^  btint^D.  aod  both  cstrud  along  the  whole  longth  »r  lh«  intMtiiie 

Ads)  lb«  pjlorus  Id  lJi«  ile)]-<'irctil  vnlvv;  but  while  Ihv  villi  varr>  good 

dMl,  betBgtbart  ond  frvr  imnKdiulely  ii«-xt  to  th«  pvloru^,  very  DumeroUB 

■nd    UrgB  (d  Ihf  <luo(l<'miiii  iin<l  iiptii-r  ]>art  of  the  mtrctinc.  Icvs  niinii^roUB, 

■iDKller,  ind  more  imrgulBr  in  (ho  lo^rr  jinrt.  ihi;  crypts  hav?  nnu-lv  tltp 

■•Rt«  ehtnctcn  and  arc  ntiirnituly  ditlnhiilcd  throiighouC     Vorr  mufh  sh 

in  tit*  cm*  of  lfa«  ftiinmch,  tht  iuti»ciiUri«  mucnent  runs  in  an  eveo  Hue 

<txcc|>t    fur    the  svmiw  of  the   valvuln'  i-onnivi'iite*))   iit  u  litile  ilUlaiioe 

il**im  iht   bMM  of  lh«  rlosely    pnched  crypts,  anil    at  a  greater  dislHDce 

(»it.  tbe  length  of  the  cnrpte)  rroin  iho  basta  of  llie  villi ;  as  we  shall  eee. 

bwmr.  the  oiuscubrw  muooeRmidaup  musL-ular  tibr««  into  each  villus. 

f  MO.  Before  proceeding  to  describe  tbe  villi  and  cry|itd  it  will  be  cixive- 

aim  lo  study  tbe  diaraetere  of  tlw  peculiar  conue^-ltve  liwue  Iyiu;j  betneeti 

(ie  raitheliuiu  above  Bi>d  tlie  uiuscularie  mucoue  beluw.    The  up)ier  nirface 

of  tbia  tisua  k  defiued  by  what  may  i>e  fpolten  of  an  a  buneniciil  niemliraiii;, 

■  hich,  however,  spfieiirs  not  to  be  here  (at  Imni  over  the  villi  i  n»  iu  the 

MaDnM-ha«nititiuou>tHbeel<<oiii|H)»e<lof  Hut  con n um ■  vc- 1 Iksu l^  corpdnc In  filled 

Mr,  but  to  have  a  Mruclure,  which  we  ■Imll  pmciitly  ilrii«ril]«.     Thv 

•larii  taaiXMae  con«iMa  of  an  outer  longitudinal  and  an  inner  circular 

t  of  plain  mufrulnrfibrea.  Iu  NonM  places  the  one,  and  in  other  placxtf  the 

atlwr  brine  prrdimiiDnnt ;  each  i>hc«t  ooiiti*ts  in  moet  cntrs  of  a  single  layer 

of  fibm.  like  couatiiueat  fibnw  being  cemented  into  flat  bumlles  nod  the 

iMiDdtaa  uDiUd  by  Bne  connective  tianic     Between  tht^  Unt  bundles  veaaeU 

paa*  Ui  and  from  the  snhiiiueou"  lissui-  Wlow  and  the  rut  of  the  muooua 

MMabrane  above  tbe  muscte  itMclf  boint:  iilso  well  provided  with  bloodnawls. 

Tl«  cvaoecttv*  tiawe  which  oocupiea  the  whole  of  the  narrow  irregular 

aoaa  bMWMa  tbe  baaonHot  membrane  above  an<l  the  luusculariii  mueosie 

balow,  cxecpl  for  the  space  taken  uji  hv  the  hloodvea^la  and  delinite  lym< 

pliBtk  VMBds  (of  which  we  Hholl  oreAently  «]ieuki,iH  of  a  kind  which,  though 

It  ii  not  ijuile  the  same  in  tbe  villi  ns  elsewhere,  is  on  tlie  whole  doeelf  allied 

lo  the  kind  known  under  tlie  vnnouB  aama 

of  rftihrm  or  nfwH&tr  connective  tiwue,  (n*.  \n^ 

arfmwrf  liaue  or  lumphnid  tiwue,  and  iu- 

hwlwJ  is  oHen  CRlled  bv  Mt«  or  otiier  of 

IhaeaaiDM.    [Fig.  116!] 

"^ptml  adenoid  tianic  such  iis  vt  met 
viitl)  in  tbe  lynipliatic  foUicKii  of  the  in- 
tosuae,  of  which  we  shall  presently  have 
to  ipwk.  in  lymphatic  gland*  and  else- 
wbn*,  pmMtle  lot  apptamnco  of  ■  tine, 
eloMBM.  and  fairly  regular  network,  nith 
lawbte  M  araall  as  not  to  aBord  room  for 
mure  ihaa  one  or  two  leucocyiee  in  each 
meeh.  The  bars  of  the  network  are  deli- 
i-wie  Hbrea  compoeed  of  material  which  is 
■imilar  to.  if  not  identical  with,  (hat  of 
the  ribrilla.-  of  ordinnry  connective  tbaue. 
At  the  ntrtlal  poinu  of  the  network  ihick- 
minKS  are  freijuently  but  not  always  pre»- 
ont,  and  wme  of  the  n>on>  ootupiououH  of 
tliMe  ihlekeniDgi  may  contain  nuclei  uther 
apherical  in  form  or  mora  or  luai  mis- 
•oapen :  but  such  nuclei  are  not  Dumeroun 
AdtfoaJd  tianie.  in  fact,  u  ootopoaed  of 
aaaHomwing  branched  cellx,  (ba  graaiar  pan  of  the  cell  in  most  com*,  and 
iaihad  Um  whole  of  the  oel)  in  •omc  cases,  having  been  tranformed  into 


S\j.V,-v(i 


.■s- 


t'V- 


caoMMBiTiu!!  or  *  «uu-  PaiQingn  nr 

Ttll    Hll~<ni>     MUUMtlll    lir    TIIK    IKTW- 

TUK,   INCI.IiMM  •IHI   KniuK  t'lvn  or 

LiKMMKiiiiH  iMDMinortuanvnita*. 

(MafulSnl  4(u  illanicmi.  | 

a.eatliyulUir  iiilul*'  fUiiilioarrfd: 
^iHHctf  it>rUiiliicti<lt>iUal  (I'll*:  r.  lb* 
loMfslanlular  or  ■4*0014  IMnw  :  0.  tpsph- 
otlk.] 


( 


( 


,168 


TUK  Tissrl 


JiW\ 


THOKSTIOl 


filfttaeotoiiB  prooenee  of  a  dit&renliiiled  nntiirc,  nhicli  join  Trwly  nitli  < 
other  and  wilh  the  like  ptrxxeaa  of  other  cells  to  rorni  h  line  ri^'ular  act- 
•mrk,  a  portioa  only  of  the  cell,  aoinetimes  with  and  >>ometimts  wilfauui  Ita 
oiMleua  t.this  bavioK  disappeared  i  being  left  lo  form  n  nodal  tliickeoin^. 

It  nay  be  regarded  as  a  leas  develo]«Bd  form  of  GOfiuenire  ttuue  than  the 
white  Rbroua  or  the  ordiuan'  areolar  conuective  liasue.  In  the  earlier  Mtagt 
of  Ita  derelopment  in  the  eoibrvu  conuective  tissue  of  all  kiodit  a  r«nre- 
■ented  by  a  iiuiabcr  of  nucleated  grauular  proioplasmic  oelitt  lyiiiK  in  n  I'uid 
or  nearly  iluid  matrix.  The  eell-bodia  are  braiicbed,  the  tirauchcM  joining 
togi^hcr  ul  inlervalfl  tu  form  a  network.  In  the  development  of  onlinarr 
c«>omH.*tivv  tiwiic  ibc  outer  finrtjoii  of  the  i^ell-biKiv  of  lume  of  the  cell*  la 
convertetl  into  or  at  knxt  p^'t*  ri.-<<-  to  (iliriUnr  E>*1at iiiifitroiin  malmal,  or  th« 
whole  of  it  may  be  >o  enlivened,  ihe  riwl  of  ihu  cpII  or  uthcr  tTfllfl  being 
)*It  m  oonnuclirc  liauiv  cor|HiiH.~lm.  In  ndeooid  tiaiuc  Ihe  edls  rvmain  as 
brandiod  ci-IU  joining  into  ii  network,  and  the  cell-wibrtaDce  is  not  in  any 
part  transformed  into  huDdlcs  of  KbHIln-,  tliotigh  it  )uu  ttndcrpiDe.  Ixaidea 
an  increase  in  ile  branching,  in  |>«rt  at  all  evv^ntu,  n  cltcmical  Irsnaforma- 
tion.^ince  the  material  forming'  ihv  ban  of  the  network  is  in  a  large  measure 
no  loajzer  ordinnry  "protoplasmic"  cell-aubstanoe.  The  meebts  of  typical 
admoM  tissue  are  always  crowded  mith,  and  practically  filled  op  by,  ku- 
ocH^tea  of  various  sizee:  it  is  only  with  very  great  diflictilty  that  the  network 
can  be  obtained  tt«e  tram  them. 

Tlie  couneetive  tissue  occupying  the  spaon  between  and  below  tlw  glanda 
of  Licberktibn  is  very  similar  to  adenoid  tissue,  inssniuH)  as  it  preaenia  a 
network  uf  delicate  fibres ;  but  the  meehea  are  somewhat  lar)^r  and  mote 
irregular  (ban  thoae  of  true  aden<nd  tiasiie,  and  though  tbev  coulain,  an 
not  cniwded  with.  leiU'UL-ytes ;  the  anvount  of  («t I  substance  left  at  aonio  of 
the  nodal  ■H>iutii  in  greater,  nuclei  are  more  abundant,  and  aciiiio  of  tfae  pro- 
fVNim  uf  ttii!  cell.-<  I'oniiing  the  bare  of  the  network  are  Hut  rxpaiuions  rvtber 
than  fibrm.  It  ixoii  the  w hole,  therefore, aomewlml  dilferent  fn>m  the  typical 
aili-noid  li«i>uc'  of  lymphntic  ?iriic<.ure9,  and  though  it  \a  oflen  ajwken  of 
under  the  Mime  name  an  ihiit  tiswuc,  it  will  be  convi-nient  to  dtMingUt^li  it 
by  some  term  :  it  might  be  calle<l  ratirtilar  tittttie. 

The  tissue  which  mis  up  the  bmly  uf  a  villus  difflsra  Kiill  more  from  triia 
adenoid  tiwue ;  it  is  formed  of  branching  cell"  whicli  linvi;  for  the  rouat  part 
ntlaiDcd  their  nuclei  and  n  larg<-r  amount  of  cell-substance  round  each 
nucleus;  the  proccwea  an  partly  mcnihninouH,  jwrtly  fibres,  aitd  some  of 
them  exhibit  a  tendency  to  form  minute  bundUsa  of  librilliv.  Il  is  iiiter- 
niedinle  between  ndentnd  liwuc  and  ordinary  oonneetivv  tissue,  and  may 
perhaps  he  described  as  forming  a  loose  somewliat  open  spongework  rather 
than  a  network. 

Lying  loose  in  the  meshes  of  this  peculiar  reticular  connective  Itsaue,  both 
In  the  villi  and  elsewhere,  are  seen  bodies  having  the  general  charaetera  of 
while  blood -eorpuseles  'see  )i  31),  which,  though  they  are  probably  not  all 
of  the  same  kind,  we  may  sjieak  of  under  the  term  of  leucocytes,  Si>i»^ 
limei  these  are  soauty,  but  often  are  very  numerous.  This  reticular  eon- 
ueotive  liame  forms,  in  fact,  a  labyrinth  of  irregular  naassK^  which  am 
nciiipinl  by  fliiiii.  but  through  which  leucocytes  can  wander  toand-fnt.  Sv« 
kIiuII  lau-r  on  point  out  thai  thia  labyrinth  of  passages  is  aasbciated  in  a  par- 
ticular tiiHiiiii-r  with  ih<-  lyiupbfltic  veasela,  and  that  the  fluid  ocoupjing  the 
8JUICC8  is  in  rt-nliiy  Iviuph.  IikIcmI,  this  tissue  ougfat  perliaps  to  be  regarded 
as  part  of  thi-  lyinpluuc  :<yi>li-rii. 

The  basrmctil  iiiiiidiniiir  9|)<>kcn  of  above  appears  to  be  formed  largely,  at 
least  over  ibi-  villi,  by  the  expanded  ends  of  fiorea  of  the  reticultiin,  which, 
reaching  the  surface  from  below.spread  out  laterally  beneath  ih«  epitheliui 


THB  STBDOTPRK  OP  THK  IKTKSTINK8. 


869 


mill  bi-!n^  juiiiei)  b\  a  i-erliiin  iiumlier  »f  cv\\»  lyirij;  Hnl  on  ilio  Kurfaw,  form 
lu^tlivr  a  nlioi't  ntiich  U  iii>l  Cdnliiiti'iu:!  btil  <li:>c(>titiiiiii>iiK,  bi-tug  hrolcMi  )>ir 
o]H>tiiiig!t  thn>iii{h  wtiicli  till*  banc*  "f  thi;  riti\»  of  tbu  Qpithttliiini  nre  broughl 
into  timUct  with  ibi-  fluid  ocnipying  ihc  xpaiti'  of  ihr  rttit'ulum  Mi>vr. 

5  361.  The  illli.  Th«'  viUi  vary  in  mIto  Hmi  form  in  (liRpju-iil  unitnuls.  Mid 
in  diRemit  partu  of  thu  iutcKtiiM!  id  (lu-Ninu)  aniiiiAl;  each  villus,  moreover, 
riirMB  in  form  nt  (litfprviit  times :  tbev  may  be  generally  i]««rrib«d  as  haviii;; 
(he  stiapv  of  a  flHtl<-iiecl  tingpr,  but  arc  froniiently  broader  at  rhp  free  eai 
than  ai  tin-  bust-:  tbcy  hav«,  in  man,  a  letigiii  of  about  I  mm.  and  a  breadth 
of  from  0.2  mm.  to  D.S  mm. 

Kacb  viltuH  consists  of  a  b«4g  of  reticular  tissue,  the  outer  surface  form- 
ing, as  explained  above,  a  bHsemeut  membrane,  nbich  is  covered  by  a  single 
layer  of  epilhflium  ailt.  [f-'iu.  111!.]  Two  kiuds  of  cells,  ihal  i»,  cellit  prc- 
aeutiDg  two  seta  of  characlere,  make  up  this  single  layer  of  epithelium. 

[Fu.  1141 


A.  Vrun  0*  HNiar:  n.  Vilu  to'  Miit,   (SIlBtiftr  snaiod  ftom Tnci«a*io(.| 

Villi  of  laloillae  Kliunlnt  ntlDinait  «Idtb»Uum  corerfCR  Ihcni ;  *l>o  (itnuM  Ualto,  iMtliii  In  Ita 
iBBba  (An  duk  tn— li.  wlilrji  an  fotM  wplUjult*,  and  ■  lacteal  it|>|ifarfn8M*  vliltr  loni|i.I 

One  kind  bn  4>»lumnar  or  nmioal  cell  [Fig.  II?],  with  Ita  broader  «nd 
foriDtnff  part  of  tin-  tnv  nurliatw  of  tht-  villun,  and  ils  narniwer  t^ml  reslini; 
on  or  lUliOg;  up  a  enp  in  llie  biMcinout  mi-uibrniii'.  The  gn-uti:r  jmrt  of  the 
vell-body  in  furmi-d  '>f  the  kiud  nf  "granular"  i.>^l!-*iili>tiinr^(t  i<p<iki'n  nf  aj( 
[>roto(>laauiir,  but  iIiHctm  in  app-iiraurR  and  <^>iiditiou  ncmriliiii;  l»  circum- 
nIaiirM;  tbo>o  vnrialtuiui  wc  iihall  Klu<lr  >«parat<-)r.  A.U  oval  niKrU'U.t  is 
plni'ed  vertically  at  about  the  loner  ibinl  of  the  cull.  At  the  fr«ie  hrtnler  of 
eoch  c<-ll  lh«  firnuiilar  wll-milNilttncv  clmngat  to  a  narrow  band  of  clear 
byaliiiD  rvlnKlive  mat^Ttal  niarkml,  in  many  prepared  spceinicnK  and  oI\pu 
4;veti  to  ti\t  fmh  alatv.  with  fiiw  vrrtical  Iin«  so  as  to  appear  siriatv^l  Ter> 
tiimlly  or  rmtbcr  radially ;  in  a  MM'tion  of  a  villus,  optical  or  actual,  the 

1'4 


370 


whole  Tillu^  BeetDi  tu  be  ■iirroundi-i)  bjr  &  bUMl  of  lliu  cloir  rvfmrtivi- 
iuai«riaL 

A  ciliated  epiihetiuni  t>carE.  m  ire  bave  seen  (S  ^3).  a  »imili>r  hynline  n- 
flraciire  border  fmm  wliicb  lli«  cilia  project  and  wilh  whirti  tUvr  an;  limi- 
ll«(:t«il,  but  wliivh  dnea  Dot  share  iu  tlie  muvemeuts  of  the  citiu  btilonging  tu 
It,  reffiaining  uu<.-bau^  iu  form  while  these  »re  moving;  its  exoc*  tiniure 
b  at  present  uowrlniti.  The  refractive  border  of  a  cotumnar  evil  i»f  n  villus 
diffen  fWxn  Ihe  xiiiiilar  border  of  a  cilisleil  oell  tn  thai  on  the  one  hand  it 
DC^'cr,  ill  vertebrates.  )>ears  cilia,  ami  ou  tlie  mher  hand  dues  under  cvrtaiu 


[FN.  117. 


[Fm.  ua. 


voimiuu  CituTtD  imatuni  Csua] 


uoataiciu.) 


dreumelant.-n'  change  its  form.  The  Ktriation  cpoken  of  above  appeoni  to 
be  due  lo  the  lad  that  the  bonkr  U  comitcttoil  of  ii  number  of  rods  imbedded 
aide  by  aide  in  n  iubclance  which  is  MmetiiuM  of  the  same  refractive  p-m-er 
u  the  rods,  in  which  case  thi^  wh')lf  ImnJor  nppcam  bonioKeoeoue,  bat  which 
it  mmeiimes  of  diflerent  refractive  poncr.  in  which  case  the  atriatlon  i>  di--<- 
tiDct.  The  rode,  which  are  thought  by  some  to  be  hyaline  proce^oe*  of  the 
unilcrlyiug  «dl-«]bslan<:e  projeetiiiji  into  the  al}<ive-im-nli»ti<^l  ceJiicnt-«ub- 
stoncG.  are  someltnieH  h>ug  and  Ibin.  Boinelinieii  short  iind  thick,  the  whole 
border  being  in  the  I'onuer  (-u>e  narrow,  io  the  lattvr  hruad.  Under  the  tn- 
flucnoc  of  reagent*  or  of  circumHancea  iIk  one  oHidilion  nuiy  change  into 
the  other,  and  the  change  wemi  to  be  an  active  not  n  iMMiive  prc>c««e,  Hnc« 
it  will  only  litke  place  »o  lonx  ta  the  cella  ar«  alive.  Tlii>  n-fmctive  boixler 
of  ihu  columniir  cell  of  a  rilliiii  ia  obvloualy  a  pceuliiir  nixt  presumably  an 
ini|Kir1ant  utriictun^ 

I  262.  Mixed  in  varving  proportion  with  Ihe  columnar  cella  pooMBeiog 
this  chnmi't«ri«tic  hyalincninrvItT  are  cells  of  another  kind,  the  ^blel  eelU. 
[Fig.  118.]  Thcw  lire  cmenttHlly  nin(y>us  celU;  in  nil  their  important  ebar- 
aciers  they  rovmbli!  tbo  mucmii'  cella  previously  described  (§  'i'Mii,  but 
reeeive  their  special  iiuinc  bcmuxo  in  shape  llicy  usually  resemble  a  gobl«t 
or  tiaitk.  In  a  burdened  and  prepared  xpcdmen  of  a  villus  numeruuH  goblet 
ctWi  uiay  be  seen  scallered  among  aud  aurrotindet)  by  colutiinar  eell^  Kadi 
goblet  cell  hiiB  a  bow,  often  irregular  and  ai^melimes  brnucbed,  lying  ou  or 
near  the  bu^ment  membrane,  and  a  top  which  reaches  ihc  surface  of  the 
villus  between  the  refractive  borders  of  the  neighboring  eulumoar  cella. 
Near  the  base  is  placed  a  nucleus,  generally  disc  abiijud,  owing  lo  tli«  action 
of  the  reagent,  surrounded  by  a  small  qunnlity  iif  xmiuing  protoplasmic 
cell-MihMuni-e.  Above  Ihii^  itie  cell  consists  of  a  niaea  of  iranH[Kirenl  mucin 
lying  iu  the  meahea  of  a  delicate  reticulum,  and  surrounded  by  a  thin  layiT 
or  suvcloiw  which  id  |>r'>l«U);i'fl  tipnurd  from  the  ceJI-subatauce  heluw,  and 
which  on  Ihe  to]>  or  fivu  itirfiice  of  the  cell  usually  beai^  a  diiiliuct  hiuimI 
oridce  or  mouth.  The  up^>er  jiart  of  the  cell  in  e<.)ii»et|iifnily  a  sort  of  cup 
filled  with  mucin  (ami  reticulum^  oud  0[>eQing  into  the  interior  of  iIm  in- 
teeline  by  a  somewhat  narruw  mouth,  through  which  the  mucin  in  due  time 
escapes. 


TBB  8TBUCTCRE  OF  TIIK  TKTKSTriTBS. 


871 


I 


Id  ■  villus  ciBinifinl  i|iiil«  frvftk  iu  tioruial  uiline  sultitiou  nome  of  tht»o 
(obkt  <vlli  Duj  be  nWn'«l  iu  a  uuikIUiou  wkk-h  bna  beeu  ilemTihnl  (^  'j:{5) 
■•  ttw  Doniial  oumlitinn  ol'  «  niuouus  i>ell.  The  t-dl  U  then  crliriilrionl  or 
oral  nultvr  tbut  dulincilv  fliuk-iiliupcd,  ami  tbu  upjxT  jxirt  ur  cbi;  cell  coo- 
iiMi  of  <TU-aulMlilllCO  Murldiil  with  grnatilu*  auil  ^pltcnilu*.  thi?  traiwuurent 
nutein  baog  thttal  nod  llw  inoutit  nut  viiiible-  Bill  in  jiertVetlx  rmiti  villi, 
■ludinl  andervvto  titc  raoM  ravoniblu  conilitioun.  moiiy  if  not  tDtmt  of  ibit 
gobbt  ctUa  will  be  mcu  tn  have  become  goblM-ahnficil,  t»  hnvn  nlmuljr 
aDdOTgaiMi  tli«  traiMfvriniiltim  into  U«lW]Mi[«Dt  nmiti  nml  rrliruliim,  nml  to 
hmxf  Bcoiirad  «  inoulli.  Iu  sucU  cm«c«  the  cWr  inuiajiuviit  bmly  of  it 
goblet  cul  atwub  out  in  strong  contrast  with  IIk  more  dim  (pvuular  liodin 
of  tbe  oolamnar  rvWf  wh!t-li  mmxind  It,  Ivith  wHmi  they  uro  M«r  on  thplr 
iide  uid  when  tlwy  arc  looked  nl  rnim  iihovc.  In  ibc  Intter  cfl»,  irhrii  ibo 
BtCTOKope  is  focuned  for  a  [loiiit  n  little  below  the  fre<'  KUrtiiec  ol'lhe  villus, 
tb«  gobJ«t  oella  look  lik«  routid  clear  droptelJ-  »cnl(ered  in  the  dim  gmuod 
fclBul  bjr  tbe  columnar  c«lU.  A  iiniit»r  ci>n(ni»l  ix  tiHorded  bv  nrepared 
■|wi<liini»  ■HiiK'i  with  carmine  and  eertaio  other  dyi»,  which  leave  ttic  traiui- 
DAreat  mueiu  uni^tained.  Under  certain  methods  or  eondiliMis  of  bnrdeiiioK. 
KtweTcr.  BKd  with  eeriain  dyes,  as  with  bwmatoxylin,  the  mucin  mav  staiu 
I  a*  dacply  <ir  even  more  deeply  than  its  surroundings. 

Obfiiiuidy  ihwe  Kobl«t  c«lls  are  simply  mucous  cells  somewhat  modiBed 
bv  mwiin  of  their  pueitioo.  Tliey  are  nut  hidden  in  iIm  rectsMS  of  on 
alvtolua  lik«  aalivar)'  mucous  cells ;  they  do  not  form  a  layer  by  theiDselva 
like  the  ipMtric  tnucyxis  cells,  but  ai-e»callered  anioii);  other  cell^  carrying 
oa  inportant  funelidiis.  Hence  amiBr^nily  their  iliape  ofa  Ktiblet  and  Ibeir 
wdl-delined  mouth.  A  ;;<>hlei  wll  to  sinrt  i^ith  i'  a  cell  «l'  a  more  or  lea 
flolnmDnr  form  and  urdiiiiiry  |>r)>|i>)diu)iuie  i-i-ll^sitbxtance.  Tbe  cell-subHano* 
nutufarluitii  iind  bv^-otmv  pluddtil  with  gntiiuleH  ur  Hjihernlcs  which  varj 

Ecdily  give  ri«;  to  mucin,  the-  cx'll  nwulh-n  nilh  il*  luail  amumcs  »  );i>lilct 
(H.  and  the  lonnation  <>l  ■  numlh  in  ih<-  Hjiacu  bctwecD  the  converging 
n-frni'tivr  Imrdcrs  of  neighboring  eolumnar  cvlU  aMMuls  in  tbe  discharge  M 
the  hiad. 

Tbe  culuniiinr  cell«  of  the  villus  are.  m  vir  ahnll  mx,  chiaflv  occupied  in 
tbe  reception  of  material  from  the  inle«tini-  into  the  body  of  the  villus;  the 
goblet  cells  arc  chietly  occupied  in  secreting  into  the  interior  of  the  intestine 
■Bucio  awl  possibly  some  of  the  constituents  of  the  kuccus  enteriCTia 

Bckxr  tiua  layer  of  ooliitnDar  and  goblvt  cells  rxtvmU  the  thin  boKment 
nwnbrane,  above  whicli,  between  the  bases  of  the  other  cells,  may  be  aeeu 
oull  cells,  that  is  to  say,  celU  with  a  relatively  smnll  (iiiantity  of  cell- 
nbbtanoe  nmnd  the  nucleus:  iheee  have  been  taken  to  l>e  reserve  »r  re(>lace> 
mrni  cvlU.  But  at  timeo  clearly  recogniirable  leucocytes  may  be  seen  be- 
tween tbe  columnar  c«II»:  these  have  probably  wsiKlerM  into  the  qiith«Iium 
floin  the  bndy  i>f  tW  villus;  and  it  may  be  that  Mime  of  the  aniall  cell*  in 
(|il«etioii  are  of  au  allied  nature. 

fSflS.  Th«  rcntre  or  ruihtr  (he  axis  of  the  body  of  tbe  villus  is  occtipicd 
bjr  a  cluli->ha|>i-d  *)iace,  •umetiun  bifurcate  or  even  branched  iil  the  dutitl 
«kI.  rarting  imlrtd  a  great  deal  in  diflereul  animals.  This  is  tlic  ccntnil 
Waphatic  spoi-e  or  "  hirtt-nl  tadicele,"  as  it  has  tte^-u  calW.  whii-h  may  lie 
Bllea  with  uitty  or  nthi-r  material,  or,  as  niorv  frequently  in  mvu  in  harrleni.-(l 
prvjMUlttion*,  may  bv  cm|ity  and  (-ulla[»>:d.  It  is  lined  nith  ci>itlicliol(l 
plates,  and  '»  nt  the  base  oi'  the  villus  continuous  with  the  lympliniic  pat- 
•ages  and  vreeels  of  the  mucous  menibrana.  Il  will  be  coDveoient  to  deAr 
tkt  further  study  of  ibis  lymphatic  apac*  until  we  come  to  deal  with  tbe 
Ijnpbatica  geocrally. 

Between  this  lymph^pncc,  niid  tbe  bnscineDt  membrane,  geoeimlly  oinit 


372      TlIK   TIBStJRS    AXn   MECRAKISHt 


UDderncfttli  ihe  laiur,  lies  a  fairly  dote-set  nelwork  of  citpillar/  vemtAt, 
MpociKlljr  well  developed  towanl  the  upper  port  of  ibe  rilluii.  Tliis  network 
is  feil  Itv  gi-ucrully  "uc  iimiill  iiN.rxy  which  •prin^iii^'  l'n>in  the  arlori«i  of 
ihv  mlimucoiis  limtic  iipliti>  up  into  cai>illnrin>  tuwanl  the  midillf  of  tite 
villiw;  nml  lh«  hloml  of  ihfi  cupillurio  piixKii  into  vcijw,  geaenWy  twti^ 
which  in  n  Mniilnr  miioiivr  pnw  duwn  to  ihv  vciiit  o>' the  «aI>i»ucwHi*  liivue. 

liotwooQ  the  basoment  int?nihrnne  itnd  tb«  cnntrnl  lymph-itpaicv  Brc  iIko 
found  II  number  of  plain  mueciiliir  filin^t.  some  ruiioire  eingljr.  otli«r«  fonn- 
iiig  small  hundlo!  of  two  or  three  libnw  a1>rcn»t.  Th<w  varj  muub  in 
number  and  diauoation  in  diUcrout  atiimnl*.  Sonw  of  thoni  lie  clow  itixter 
and  end  in  the  btiwnient  membrane  ;  olliera  lie  nearer  tbo  lymph-Bpnce,  to 
which  in  hohic  aoiinals  tliey  form  a  »irt  of  luusciilar  sheath.  Thew  fibres 
belong  to  Ihe  luuHculariH  iiHicoaie:  at  the  bnse  of  the  villus  the  6brea  of  lli« 
rauftcalaris  diucobw  lake  an  upward  (.-outw,  passing  between  the  adjacent 
crypts  of  LieberkUhu,  and  run  into  the  villus,  following  most  commonly  a 
longitudinal  but  aonietime«  ii  mure  or  l«aa  oblique  or  even  a  transverse 
direction.  Hy  the  eonlrattion  of  these  fibres  the  funii  of  the  villus  can  be 
changed;  but  we  shall  return  to  this  point  »'heu  we  cnnie  to  s{«ak  of  il>e 
absorption  of  digeated  material  by  nicuii»  of  the  villi. 

All  Iho  space  intervening  between  the  basement  membrane  and  tlie  ecotml 
h-mpb-spaoe  nhitrh  i*  not  taken  up  by  ihe  hlutMlvenelB  and  Uie  muscular 
nbm,  it  oceupied  hy  thi;  Kj)eeial  kind  of  retieular  eonnecliire-tusufl  docrilied 
above  (§200),  tbo  ni<«h<»  of  which  are  lu  a  greater  or  leas  extent  oocupi<^ 
by  leucocytea.  On  the  outer  surfncB  of  the  body  of  the  villu:«  this  reticular 
tissue  is  connoclcd  with,  and  indc«d  iix  wc  have  seen  forinH  the  bawoKiiC 
membrane:  in  the  centre  it  furnis  anjund  the  epitlieb'iid  jilales  of  Iho 
lymph-spaco  the  walls  of  that  cavity,  nml  suppUc*  a  nimibir  bed  for  the 
blooi!  capillaries;  the  fine  oouoective-tiMues  lielongin^'  lo  the  small  bundles 
of  muBciilar  fibres  is  continuous  with  it,  and  iome  of  the  muscular  fibres 
ai-ciu  111  c-ii(l  in  it;  to  it  also  is  atlnclieil  the  (-onncctive-tiMUc  of  the  "uter 
nalii  of  the  small  artery  ajid  veins.  The  body  of  ilie  villus  is  in  fact  a 
OpotiKe  work  of  reticular  tisttue  in  which  are  evacuated  the  lymph-apace  and 
tne  blood  channels  with  thi-ir  m)[ieciive  linings,  into  which  ihe  plain  niue- 
cuhir  fibrus  plunge,  and  which  is  condensed  on  the  ouUide  into  a  basement 
membraoe.  The  m<»h<4  of  the  ajkih^  work  are  further  occupied,  as  we 
liave  said,  wiili  luuc-x-ytm  or  wiih  uuciealed  oella  of  an  allied  but  diller^iii 
nature;  heoco  in  unliunrv  "lained  apeoimens,  not  specially  prepared.  il>e 
lymph-space  and  bhvul  chunneU  being  oollnpaed,  the  whole  body  of  tin 
villus  ap[><!an>  a  cunfuw»l  miM*  of  nuclei ;  there  are  the  nuclei  of  the  mu»- 
cular  fibre*,  the  nuclei  of  the  epithelioid  plated  of  the  Ivmph-siMce  and 
capillaries  and  of  the  other  coata  of  the  arieri,-  and  veins,  tlie  nuclei  of  the 
leucocytes  in  the  muhea,  and  lastly  the  nuclei  belonging  to  the  ivIictiUr 
ti»ne  itself. 

The  tbicknon  of  the  body  of  tho  villus,  that  Is  lo  say  the  amount  of 
TCticular  and  of  the  other  tinues  lyiu^  between  the  boM*  of  the  ciHtbcJium 
cells  and  the  central  lymph-space.  vaniM  in  dilTorent  animais,  being  for  in- 
elance  considerable  in  the  doc  ami  small  in  the  rabbit ;  in  the  latter  nniinol 
tlie  inuseiilar  fibres  are  ver}'  k^uiIv. 

$S04-  The  rrypU  or 'jt/iiidr  fj  IjitbrrkuhH.  These  arc  found  cverrwliere 
nlunt;  the  whole  leu^th  of  the  small  intestine  from  the  immediale  vicinilv  of 
the  pylorus  to  tlie  ileo-oscal  valve,  except  immediately  iinderiicaih  each 
viltuB,  and  in  the  ^poU  occupied  by  the  lyuijihnlic  folliclee  of  which  we  sbiUI 
pK-nentlv  sjwak.  Tlw  mueoits  meuihraiie  or  the  Hniall  intestine  is  in  fact  to 
n  verr  ^argc  extent  iiiiide  up  of  a  number  of  these  short  tubular  ^'otids 
|>lac«(l  aMo  ujr  side  luid  packed  cki&ely  toother,  though  not  so  clueely  as  th« 


373 


iiilnrlj- 


it  cnnlbf  glnnHt 


(he 


['h:  th< 


tcUnds 


I 


It 


slonin 
ncx>  of  tlio  iiik'xlina)  mucous  memfoimaci, 
and  llw  muHtilBm  mucoe^r  nitis  in  n  Inirly  even  lino  a(  eame  lilUe  diEUiDce 
bvltnt  thotD,  ihsl  is  oiiltiHe  their  bliixl  eni|«.  Knch  ({land  is  a  Btraigfal  or 
atmrlr  Hrni^bl  tube,  rarely  iliviHin);.  nbout  400»<  ioof;  and  70u  broad.  The 
■wtltDe  is  fiimisb«<I  by  a  ver^'  dminct  bssemcnl  tnembrane,  in  which  Ducki 
arm  UiAteMtd  at  intervals,  and  this  boBemeat  nietnbranc  is  lined  with  a 
MOi^  Urer  of  short  cubical  cells,  leaviof;  a  small  but  digLinct  Iiiraeu;  the 
oalbaboiild  perhaps  be  ratlier  detcrilied  ta  eomewlint  conicAl,  with  a  brotuJer 
b«>r  U  the  bsBenient  membrane  and  a  oarrower  aj>ex  abuUiu^  <ni  ibu 
luDirt).  The  cell  body,  aurraunding  a  somewhat  spherical  nucleus,  iit  faiotly 
gnuolar  «xcepl  for  a  hyaline  free  burder.  which,  however.  i»  ni>t  *n  oon- 
■picaoiu  or  ao  consiaot  as  in  the  eoKimnar  oells  of  the  villi.  Similar  celb 
Cttnr  ibp  ridifM  iiiterveuioe  between  adjacent  irlaniU.  and  where  a  villus 
ennci  orxt  t»  a  clood  llie  snort  cubical  cells  or  the  f;lnnd  may  tic  tnwod 
intii  mlomiinr  crlU  of  thi.-  vjlluf,  the  hyaliii«  border  becomine  m'irc  marked 
and  ibr  nuclcu*  IxH-iitiiing  oval.  Amno);  the  cubical  cells  nf  the  j^hind  iiro 
In  bv  fcund,  in  varyinn  iiuinlx^ri.  j^ihlct  ccIIn  l{uil<^  liimllar  to  (hiwc  of  the 
tIIII.  Ii  (•;tuv(imvi*  hapiH'ttii  that  duriiit;  the  )>ri.'iiaralii>ii  of  a  sperimc^i  the 
wtiola  CDJthaliiim  »  s)ie<i  en  twure,  the  cell*  being  much  mors  adherent  to 
•aril  otoer  thati  to  the  basement  membntnv ;  in  such  a  case  the  features  of 
tbo  bwinvnt  lucmbranv  an;  well  *een. 

Out«ide  ihe  bucm«nl  membrane,  between  adjacenl  glands  and  between 
tfa«  bliix)  eiid*  of  the  gUnd:<  ami  tlie  tioderlying  mmkrularis  mucosn.  Is 
tvtiraUr  coBnoctive-tiHue,  tincr  and  more  truly  rocicutar  than  that  of  the 
rilli:  it  is  perhaps  len  crowded  with  kucocytos.  In  this  reticuhir  lEssue 
run.  mctrcling  the  glnndn.  cApillary  bloodveeecls  nipplied  by  small  artfries 
cxHRtOff  from  the  Mibmucona  (issue,  aad  pauriny  their  ciIoihI  into  currvapnitd* 
iwrras,  and  with  thi^  iviii-nlar  tiwmc  lytnuhacit^  are  ennnected. 

TliMr  glauiLi  of  LielM'rkuhn  are  suppcisei)  to  funilsh  the  suocus  ftntericus. 
The  ra*an«  for  thia  rteu-  lie  iu  their  tubular  form,  which  is  that  of  many 
verntinn;  mlnnds.  In  their  lumen  beioK 
toil  namiw  for  tlw!  puuigc  of  food 
iulo  it.  anil  in  tlM  fad  ibst,  at  wesliall 
tlwy  unlike  the  oluninar  cells 
V  th«  villi  are  not  concenicd  in  the 
abairplion  of  fat ;  otberwife  lliere  are 
o<>  dvliniti;  fads  to  prove  that  the 
cubtral  cells  are  c^mci-rnwl  in  >«re- 
li»a  only  »r  that  t1>ey  may  not  alworh 
BMitcr  (iIIht  than  fat.  The  gnhld 
oells  in  ihew  glands  ns  in  the  villi 
certaiDty  sevrde  mucus,  and  may  w 
mte  also  Slime  of  tlw  oocistituenl*  of 
tbc  Biin*us  entericDB. 

Besides  tbme  glaude  |>roperlT  an 
called,  that  u  to  say  involnlioits  of  Iho 
epitbeltal  (hypoblasticj  mucous  mem- 
bnuta,  there  are  fouod  iu  the  niHcous 
nnnbrane  bodies  bdoncing  to  the 
lvn)|>hsti(-  arstem  also  oftf-D  calleil  inlands,  vii..  the  colitarr  glands  and 
tlie  MtRiutoti^l  Elanibi  or  pntcfaes  of  I'^ycr.  We  shall  spealc  of  these  U 
lynpluilir  fulticles,  and  it  «ill  )>e  convenient  to  itudy  them  aepaniUly  in 
ooooortion  iiiih  tlw  lymphatic  system. 

{SM   Imntedistely  Mow  the  pylorus  in  nan,  but  varying  soroewluit  la 


[no.  iiK 


hsntua  or  cat  or  ttai  ntiu'*  ni.uita,  raoM 
las  UvKin  DtovcHnt.) 


ST-1 


THB 


poellioii  in  difivrent  animnli^,  nre  the  j^lnDdH  of  Bninnff  {Pig.  119].  Thno 
ninv  be  reKarded  as  laodKicaiioiis  i>f  liie  pylorit?  glaiuls  of  lliv  Momiich.  In 
cui-)i  ^'Imitl  u  iluci,  IiDed  with  short  ci)luiiiiiar  (•pitl>ciiuin  c-elli  leaving  a 
i]ii>liiir-i  luuicti.  exteoda  atDu^Ie  for  eume  dislnace.  and  piercing  the  luuscularis 
iiiHiMMu  (lividea  in  the  aubinucuua  liMtuo  into  n  number  of  lubee,  whirh 
Kuliiliviiliug  luke  n  Lwbteil  coune  and  end  in  alighl  entargemeDU  or  slvmli. 
1  lit  ci-Ile  lining  lioth  ilie  hranching  tubes  and  the  ulveoli  »n  abort  eiibieiil 
cvIU  uiili  lUi  iiidiftlincl  outline,  ttimilar  L'l,  hul  in  a  freah  coudition,  iu»re dis- 
tinctly granular  tliiui  the  cell*  iif  the  guMtric  pyloric  glands.  Uiindlee  of 
plain  musetilnr  Ilbrus,  ntraggkra  from  the  muacularis  oiucueue,  are  ecaltensd 
among  iln-  tuheti. 

Th«wo  gitinil*  of  Briiuner  when  traced  liavk  La  the  flt»Riach  are  fotrnd 
lo  pamgrHdiiiilly  inlo  the  i>yli>ri<!  rlanda;  iruotnl  along  the  int«Mine  they 
soon  di!3it>|>ritr,  tlx'  dui-la  iif  thitti:  gmiuU  which  n»u'h  intu  the  du(Mh>iiuni  ao 
ftr  u  lo  lie  ll'iind  in  c'i>mpiiny  with  the  glnndn  ni  Lieberkiihn  nml  villi,  vpeu 
into  the  luiuinH  <il'  the  t>iriiir-r. 

Il  is  not  clear  ihnl  uny  nppcinl  piirpfwe  it  acrvnH  by  thcwe  glnmU  of  Brun- 
ner;  an  extract  of  the  gbind«  is  tniil  to  digest  Rbrin  in  tho  prMcnce  of  acid. 

Thf.  Iiarifr  Iiilatinf, 

^266.  The  gi*ncra)  plau  of  ^ilriicture  of  the  large  intestine  is  the  wme  aa 
that  of  thti  «niall  tut«aiiuc.  the  aalieiU  pninu  »!'  ilUiincliun  being  the  absence 
of  villi,  and  a  poouliar  arrangeiuciit  of  the  lougitu'linal  coaL 

Instead  of  being  unUornily  dUtributeil  a^  a  thin  layer  orer  the  whole 
circumfcnnci'  of  the  tube  an  m  the  >ma1l  intt^iine,  tbc  l»ngiliiiiiual  ooat  ia 
in  the  large  inlctine  chiefly  gatbcreil  up  iuto  three  ihidcened  handa  or 
bundles,  being  vt-ry  thin  oWwliTC.  TliMiri  biLn<J«,  morodvcr.  are  eburt«r 
than  what  may  be  calli-d  the  natural  length  of  the  ink^itine.  «»  that  the 
tube  ini^tead  of  hoing  us  in  the  small  intivtine  uf  Ikirly  iinifurni  boro,  is 
[tuckered  up  into  "eacculi"  iQor«  or  l«ai  divided  by  the  three  bands  into 
group!!  of  three.  This  sacculated  arrangenient  anawcrs  much  the  same  piir- 
pMc  tut  the  arrangement  of  vnlvulic  connivcntes  in  the  smnll  intestine.  The 
circular  muacnlar  layer  is  thicker  in  (lie  middle  or  bellies  of  the  eaeculi 
thau  at  the  puckers,  where  it  is  very  thin. 

The  villi,  as  we  have  Jual  said,  are  wholly  absent.  Id  the  lower  part  of 
the  i>iimll  iiitetiliae  lliey  become  fewer  and  smaller,  and  none  at  all  are  found 
t)er>iml  llie  ileo-cjecal  valve.  An  increase  of  surface  is  provided  by  longi- 
tudinal ridjcei,  but  these,  like  the  corresponding  ruga?  of  the  stoouiob,  involve 
tho  nbole  mucous  membrane,  including  part  of  the  aubmucous  tissue. 

The  glaiidii  uf  Lieberkiibn  in  the  large  intestine  are  in  the  luaig  like  thoee 
uf  the  «uall  iutefline,  but  larger  and  better  developed,  being  both  deeper 
and  broader,  and  owing  to  the  ahseoce  of  villi  are  more  easily  atudied.  The 
cells  of  the  gland*  have  the  same  diaracters  a»  in  the  amall  niteatine.  except 
that  th«  bvaliue  bonier  ta  rardy  preneot ;  goblet  cella  arc,  perha|M,  more 
abundant  (hnn  cvt'n  in  the  .irnall  intenine,  especially  iu  itome  animal*.  On 
tlie  ridgi^  lirtwcen  (be  glandii  the  eelU  become  longer  ainl  thinner,  and  the 
byiiHnc  border,  frei]iiently  striated,  mak<«  il«  B|i[>carancu.  The  marked 
dcvelopmoDt  of  thou;  glandii  in  the  large  intO'tino  a  noteworthy  sinca,  a*  h*c 
ahall  SCO,  nlwirplii-n  of  mjilrriiil,  nnd  not  tho  secretion  of  digortive  juice, 
U  the  chnrarierii'tie  W'>rk  Dl'llie  largt  intmtiiie.  Il  can  scarcely  be  ima^ned 
that  abs>:>rpli'>n  takes  place  only  at  the  ridges  between  ibn  gfands,  and  not 
by  the  inmx-iisely  larger  amount  of  surmce  which  is  presented  by  the 
iDteriors  of  all  the  i;InniU  ti<i:ether  :  but  if  these  glands  absorb  in  tbi;  l«rg« 
intestine,  ifaoy  probably  act  in  the  samv  way  in  the  small  intestine. 


TUX    HtiHCl'LAK    UKCIIAN'IHUS  uK    DlflKSTIO.V. 


375 


liynntuilic  follieta  tat  abuiMlant  in  lh<-  Inrgc  iiitrvtino,  t1i>-  fjcaiin  iiml 
Miaaulr  tbe  spfeDdix  TwiDifarniu  being  cromlcd  wiih  N>liiiiry  folliilcs. 
Ttn*  iMtirh<v  of  PoycT  arv  Hbacnt, 

^S67.  Tht  rrfluM.  Anbe agtaniA  nrxxtn  jwm  inlothr  n-ctum  tlw  ibree 
bftDtb  of  ibc  lunijitiHliRnI  iiiu^eiilHr  cmI  ■(■rtuul  ou(  aiii]  becoio*  onoe  nwre  > 
onifonn  Uy«r.  and  with  ihu  chnni^  itie  Micciiltitioti  dMnppcan.  Tiis  (onxi- 
todinal  coal  is  niat>Dii«d  to  Ibe  aous,  vhvrv  ii  coil*  uhniptir-  T)i«  cimibir 
euU  M  it«  temitoaliun  at  tbo  anuB  is  d«Te)o[>ciJ  inio  n  iJiMiDct  ring,  lh« 
islMiwl  >|iliiiict«r. 

Th«  D1III.-UUII  iDeiobrane  ■■  thruwii  inio  numcrouH  folds  or  ridga  urliicli 
bcluoarv  longitudinal,  bill  higbcr  up  oMii^uc  or  even  iransversc  iu  dirM-tiou; 
to  fmtmit  the  fcrinatlon  uf  ihete  fulds,  wtiicb  lire  oblilcratwl  u'li«n  Uw  re«tuiu 
ia  fatlT  diitvnik'd,  tbc  riubmucouB  tisrae  i>  more  nbundoot  and  more  IoumIjt 
dvTvbiprd  than  in  tb«  t(*i  of  the  inUsline. 

I>a«n  ft  tbv  margin  uf  tbe  iioud  tbe  uucoiia  membrane  retaiiu  Um  cbar- 
mdan  ftf  Um  larso  iiilwtinv.  jilnnda  beinjr  still  pr«aeut ;  it  iben  abrnjrflj  pitta 
«  tk«  flpilihuuio  diarnrti^rn  uf  the  epiilcrniin.  Tlie  rv<-luni  bw  ii  »|)ocial 
mirvaaa  wpplj.  but  uf  tliLt  wc  ithall  >])«uk  in  ci>iuiecti»n  nitb  ihv  iDOT«neata 
of  tbm  alunenlarjr'  mmtl. 


I 


Tbe  Muscular  MKCBAimm  of  DioEffriogt. 

f  M8,  Prom  iti  etitrance  into  tbe  monib  nniil  buoIi*  retunant  of  it  ns  ia 
uadigoted  leave*  tbe  bmly,  tli«  fund  ia  oontinunlly  iiubj«i-ted  in  inoTomeuts 
bartufc  for  ihnr  objwt  the  triluralioti  of  tbe  food  M  in  Taimtiailion,  or  jta 
mora  nuiintvte  mixture  wttli  tlie  dige«uve  juices,  or  it»  forward  prarrefla 
tbmvKh  tbc  alimentary,  csna).  Tbuw  various  inorcnicnta  uiny  briefly  be 
oaa^£nd  in  dciail : 

Mattintion.  Thi*  in  ninii  consists  cbi«fly  of  an  up-and-down  roovement 
of  Ibe  knrn-  jaw,  combined  in  tlvc  grinding  artion  of  tho  molar  teeth,  wjih 
•  evuin  antount  of  latornl  forv-at)d->n  moratncnt.  The  lower  jaw  i*  ntiitod 
trv  mmat  of  the  temporal,  masMt^r.  and  internal  ptcrygoiil  roiiAcl«t.  Tbe 
Mgbtweflbn  ntdcpnarioo  brings  into  artiuo  cbiedy  the  di^fattrir  miiM-le, 
tltfMtsh  (be  mTlo-hyotil  and  i^eniohyoid  probably  share  in  the  roattrr.  Coo- 
tnMtuHi  of  the  etlrrnal  {iterygoi4ls  pulls  fomard  the  ouiHlyln*  and  thnuti 
1^  lover  tenth  in  front  of  the  upper  Contraction  of  the  pterygoiids  on  one 
iidia  will  aUu  ihn^w  tbe  teelb  on  to  tlie  opiiofiile  Hide.  The  lower  ItoriiMn tally 
plaMd  fibrti*  of  tbe  temporal  atrve  to  reirai-t  the  jaw. 

Puriog  inaniieation  the  food  b  nwred  tu  ami  (W>  and  rolled  aliout  by  the 
navMMOta  <>f  tba-  tongucL  Tbeae  are  aflk;ted  by  tlte  niuvclce  of  that  or^^ 
gemntA  by  iIh-  liy|xiflawal  nerve. 

The  act  of  ma«licBliijii  u  a  vuluniarv  one,  guidnl,  b»  ari-  so  mnnv  volun- 
tary a«-l«.  not  only  bv  muMnilar  aeiiw,  but  aUo  by  cifutact  MnsationA.  Tbo 
iDtMiir  fibres  nf  tbr  tit\h  cranial  iien.'C  convey  rootor  impulaca  from  the  braifi 
to  tbe  above-men  I  ionod  muiwlca ;  but  mrolyiui  of  tbe  wnsorr  fibre*  of  Ibe 
■Mna  aenre  reiMler<  nuutioilion  difficult  by  depriving  the  will  of  tbe  aid  of 
llw  usual  aeDaalMHu. 

jS89.  Dtylulilioit.  The  fnod  when  sufBnenlly  mariicated  is,  by  tbe 
mavnoents  »f  th«  longriK-,  gtalhi^ml  up  into  a  bolus  on  iJw  middle  of  (he 
DpfM-r  aurfiice  of  that  cir;[aH.  Thf  IVunt  of  the  tongue  being  raiwd— partly 
hy  it»  iniHnMi'  muscles  and  nnrllv  by  tlie  wtylo-gl'wwe  'the  bolus  is  tbrutt 
hack  betwprn  the  lon)C<ie  and  ihi-  |inlat«  through  tbe  anterior  pillar*  of  the 
liUKea  or  isthmus  laut-ium.  linriiifli.iidr  before  il  nrrirot  there  the  soft 
b  raised  by  the  lovauir  patali.  and  m  brought  lo  touch  tlie  pusleriur 


87lf        THK    T18SUKS    A  N  H    M  KC  II  A  X  18  Jt8   OT    DICIKSTION. 


wall  or  the  ph.iTjrix,  which,  by  t)ie  contraction  or  the  iifi[<^r  niiir{(iD  of  iht 
superior  conetriclorof  the  phiirynx.  buI)-CH  somewhat  torua'tl.  l1i«elevittioo 
of  iheaoft  palate  CAUSM  a  (liBiiiict  riae  of  preaaure  in  lJi«  luwal  cliumbort ; 
tliitt  can  be  Bhovfn  bv  tiilruduciug  a  tviiier  niaDomecer  iuto  ooe  imttril  ntid 
oluaing  the  other  just  orovioua  tn  swallowing-  By  the  conlrai-licm  of  the 
palato-plisriTDfceal  muscles  which  lie  in  ilie  pimieriur  |nllan  of  the  fniin«  the 
curved  edges  of  those  pillan  are  muilv  mraiithl.  aud  thun  lend  tn  aic«t  in 
the  middle  line,  the  small  Kap  hetween  llit^rii  hein^  llllcd  np  hr  thr  uvida. 
ThrDiich  tlit-it!  ninno-vrnt  tlie  eutrnncc  Intu  the  iii>«tm<>r  nnrec  is  hlttckcd, 
while  lIic  ti'ift  pulnte  if  fiirmvd  into  a  .iloping  rour,  Kuidiiig  tbo  boltu  down 
the  phnrvux.  By  the  cuiilrutniuu  of  the  ntylo-pluirrDgaiu  uid  palato* 
phiu-vngriiA>.  the  runn''l-i'hnpi.-<l  hag  iif  ihc  pharynx  u  Drought  up  to  meat 
the  (l»c<'niltng  nion*ct,  very  much  u-*  n  glove  may  be  drawn  up  over  the 
finger. 

MeaDW'hilc  in  the  Inrrnx.  a»  shown  by  tlie  InryngMwpe,  tJie  arirUowd 
cartila|,>es  and  vocid  corus  are  approximated,  the  latter  being  also  reiaed  ao 
tJial  they  conic  very  near  to  the  lalse  vocal  corde ;  and  the  cushion  at  tiie 
base  of  the  epiglottis  covers  the  linin  glottidis,  while  the  emglottis  itself  is 
depretaed  over  the  larynx.  The  tliyri>id  cartilai,-*  is  now,  Dv  the  Bctioii  of 
tJw  larA'ngeal  luiisclee.  tiuddeuly  raised  up  behind  the  hyml  liooe,  and  thus 
aaiiatN  th<f  eiiigluttls  li>  cover  the  (;loltia.  Thia  uiuvemeul  of  the  thymid  cud 
easily  be  felt  on  the  outside.  Tlius,  bulh  the  entmnoe  into  the  [luyturior 
uiirtw  and  that  into  the  larynx  bvini;  chuted,  tlie  impnlw  given  to  thi!  boln« 
by  the  tongue  nui  tiave  no  other  ctl'iH't  than  to  jirojiel  it  bc-ni-ulh  tht  sloping 
wd  palnle  over  the  iticliue  formed  hv  thv  nitit  of  llu-  tou^uu  and  the  epigluUi*. 
The  pHlal»  ghuni  or  cimittrir-toren  wtbmi  fauciiim,  which  lie  m  the  anterior 
pillnrv  of  tho  fiiuctu  by  contracting  clunt  tJiC  door  behind  the  food  wbicb  liM 
p«»cd  them. 

When  the  bolus  of  food  ia  large  it  in  received  by  the  middlo  and  lower 
conslrictors  of  the  pharynx,  which,  contracting  in  eequrnce  from  above 
downwar'l,  Ihniftt  it  into  the  (ceophngus, along  which  it  is  driven  by  «  similar 
lerie*  of  succi?eaive  couiraclions  which  we  shall  speak  of  iiuiuetlialelT  as 
periylaltic  action.  Tlii;  eoiiiparalively  slow  deec(<nt  i>f  the  food  from  lh« 
phnryux  into  the  stomach  may  he  readily  ^een  if  animala  with  lonf;  necka, 
anrh  as  hor«a  8n<l  dogw,  bo  lAati-hed  while  swallouing.  When,  however,  the 
DMmi'l  is  nut  large,  or  when  tlii?  .xuliBianee  swallnued  ia  Uijuid.  the  movement 
of  the  txick  part  of  the  tongue  may  be  sufficient  not  merely  to  iutrixluoe  ibe 
food  intx  the  gra*p  of  the  couslrictora  of  the  pharynx,  hut  even  lo  pru|)el  it 
rapidly,  to  »h<3ot  it  in  fact,  along  the  tax  naopfaagua  before  the  mn^cUv  »l  that 
organ  have  time  to  omtniet.  In  Much  a  mode  of  swallowing  the  middlu  and 
lower  conntrictort  take  little  or  uo  part  in  driving  the  fo<i<T  uiinard.  lh»ii>.'Ii 
they  and  the  (rwphnguK  upiinir  to  cuiitraot  from  atHive  donuwiird  at\cr  the 
food  has  pimcd  bv  them,  as  if  to  ci>mplcle  tbti  act  nuit  lo  iniinre  that  nothing 
haa  beeo  left  bchmd.  t><-glutitinn  in  tht»  favhion  still  rcmninn  powihle  after 
tbeae  oonalrictore  have  heconw  paralyzed  by  lectinn  of  thvir  motor  nervtw. 

When  a  second  act  of  degliilitioii  tuccetMl^  n  fint  with  iiiilltcicnt  mpiditjr, 

the  nervous  changes  which  itnrt  the  phnrynL'ral   mi>rcmviits  of  the  fccontl 

Upct  appear  to  inhibit  iho  teeonhngenl  movcmenlji  of  the  lirel  act;  and  whoa 

Birallon ing  is  repeated  rapidly  several  times  in  lucccwion,  tho  taaophagua 

reniaius  ijuiet  and  Ian  during  the  whole  time  until  immediately  after  tbo  Uist 

•wallow,  when  a  iierii>tallic  movement  cl'Kfcs  the  series. 

Wlien  the  atethuM'0|K-  is  applied  over  the  cesophagus,  at  diflbreat  regioua, 
a  MWind  li  lieanl  during  deglutition  ;  situeiinies  two  sounds  are  heard.  The 
flnt  and  motit  conaiant  in  coincident  with  the  pauageof  tiie  bolus. and  is  due 
to  Ihi*  and  to  lliv  mtisculur  <wuud  uf  the  oontraetiug  inuAolea.  TIte  later  and 


TUi:    UVBVVUAtt    MKCIIAXISMii   Of    l>H)K8T10N. 


377 


coiMUnt  KKiad  appi-ara  to  be  caused  hy  a  (juatitity  of  aii^bubbla  with 

>b>ch  tk*  bolua  waa  Miuigled  ludgod  at  the  cardiuc  etid  of  lh«  meophagua, 

:  Ibroad  tii(n  tlte  stomach  by  the  se<|ueul  periBtaltic  coDlrnctiuu  of  the 


I 


I 


It  will  ht  4*en  fntm  what  haa  beoii  suiil  that  ilvglulltiuo.  though  a  ron- 
tlniMufl  act.  tiiiit'  1>e  re|[ar<kil  nn  divided  into  thnw  sitiga. :  lUw  tint  &ta^  is 
tha  libnulinff  of  the  fiwd  through  the  iathiuiiH  fatinum  ;  this  may  bo  either 
of  Ionic  w  Nwrt  duratioo.  Tlie  Mcood  tinjje  ).i  the  paMage  through  the 
up|vf  [lan  uf  thv  iiharyux.  H«rv  ibo  fuuil  triiviTMv  ii  region  cuinmon  hnlh 
la  the  loud  anal  to  ret|nratiua,  and  ia  coiiMijuaico  thv  movotntMit  in  a*  riipid 
aa  Bonible.  The  tliin)  Htage  U  the  detoeot  through  the  gnup  of  the  con- 
■UMOca.  Here  the  food  hiw  pataed  iJie  rapiratory  oriSce,  aiul  in  oudm- 
qaeaoa  ita  punge  sgoin  beconua  wrapamttvely  mIow,  except  in  oud  of  fluid* 
wad  anall  non^.  wh«n,  »  ire  hnre  fetn,  it  may  continue  to  be  mpid.  The 
BMM*  along  the  owopfaagu*  may.  pcrb>|i«.  be  regarded  na  contUluting  a 
■mrtb  ttBfa;  but  it  will  he  more  citnvcfliieot  to  coosidor  tin-  nMophag«al 
mowmaim  by  thmiKlv**. 

The  Gnt  atoge  in  thia  complicated  procom  it  undoubtL-illy  a  Tplunlnri'  act. 
Tb*  raMM  of  Ibo  soft  palate  and  the  approximation  of  tlic  |>otilpiior  pillara 
aB>j  aim  fw  at  tiniea  voluntary,  since  they  have  been  teoo,  in  a  ave  where 
iIm  pharynx  was  laid  ban-  by  an  operaliou,  to  take  place  before  the  Iboil 
had  iiiat'ti«d  three  parl«;  but  the  movement  may  take  place  without  any 
rjii^'iic  of  the  will  and  in  the  aWnce  of  consciousneaa.  Indec<l.  (he  second 
atu«,  laken  as  a  whok-.  thmi-^h  some  of  the  earlier  componeul  movemcnia  arc, 
■•It  were,  on  the  liurdcrland  lietween  the  voluntary  and  involuntary  kingdoms, 
muat  be  re^rded  as  a  r^ex  act.  The  iliird  aii'i  last  stage,  whatever  be  the 
ouct  fimn  which  it  lakea,  is  undoubiedly  reflex;  the  trill  liaa  no  power 
whatever  over  it,  and  can  neither  originate,  stop,  nor  mwlify  it. 

Drchililion  in  fact  n>  a  nholu  is  a  rcAox  act ;  it  cannot  take  place  UDlen 
■(MB«  Mtniulu*  1m>  nnplivd  to  the  mucou*  niembraiw  uf  llic  faiicn.  Wlioo  *• 
V«luiitaiT  bring  aoout  fwnllowiiig  movcjacnta  with  tliC  mouth  cm]rty,  ire 
Mpplv  lae  iMoeaMry  atimulun  by  forcing  irith  the  tnngue  a  »inall  ijuautity 
of  MU<ra  into  tlie  faurm.  or  by  touching;  iIh-  lau«.-ca  nilh  the  Inniine  itwlf. 

la  the  redex  act  of  deglutillun.  cauKil  in  thv<  onlinary  way  by  the  ftMxl 
eowittf  in  contact  nilh  ifie  fauces,  the  Rtfercnt  impuiHa  originalod  in  the 
6mmh  u«  ctrried  up  to  the  nervous  c<-nlre  by  the  gloeBo-pharengcal  nerve, 
bjr  braacfam  of  the  fifth,  and  by  the  pharyngeal  bnndies  of  the  nipcrtor 
Iwjugcal  divUion  of  the  vagus.  The  latter  seem  of  special  importance, 
ifawe  ibe  act  of  swallowing.  i|uile  apart  fr<im  the  presence  of  food  in  the 
nonth,  may  be  brought  dui  by  i-t^ntrifwlal  alimulation  of  the  (superior  laryn- 
fltmi  nerve.  The  elTerent  impulaee  d^-end  Iht'  hypov'loMal  lu  (be  musclea 
of  ibe  tongue,  anil  pau  down  the  glwau-pliaryiigeui,  the  va;^iis  throii^h  the 
pb«ryti):v«l  plexus,  the  fifth,  and  the  -iiiinal  aooeaory.  to  ihi-  mitM-les  of  the 
nima  ami   pharynx ;  their  exact  patlu  being  as  ye<  not  fully  known,  and 

erubably  rari'ing  in  diflerent  animals.  The  laryn^al  musclea  are  governed 
J  iha  larragcaJ  brancbca  of  the  vagii*. 
Hm  OMitre  of  the  ruHex  iK't  itm  in  the  medulla  oblongata.  Degliitilion 
BW  be  exdted.  by  tickling  the  fnucm.  in  nn  animal  rendere<]  uncoiucioiin  by 
raowival  of  thv  brain;  provided  the  medutla  be  left.  If  the  mt^dulla  l>e  de> 
Mnijed,  deglutition  is  mi|XNMible.  'I  he  centre  for  deiHutitiim  lit*  higher  up 
ibaa  that  of  in>|>inU»on,  so  thai  in  the  disMMe*  or  iojuricd  involving  lh«  upper 
|«rt  nf  ihr  UHiiuIIn  oldongatn,  thi-  former  act  may  be  impaiml  or  rendered 
■  mp<«Mble  whiU*  the  hitter  reuiiiins  untoiichot.  It  ha*  lioen  wkid  to  furm 
part  of  the  ■uperior  olivnrr  ImhIIiv,  tail  thi<  vi^-w  in  luueil  on  anatomical 
>niU  uuly.     We  shall  have  to  dvnl  with  tliui  and  tiuiilar  matien  in  treat- 


378 


THE    TlSSrKE 


inp  "f  tlm  iviitrnl  ii«rvout  lyKlcin.  Il  i*  |>ri>biiblu  tliat,  U  ut  the  caHi  in  W 
luiiDV  nilicT  rt-lV-x  ii<;u,  the  whole  niovcnieiit  cun  bo  caSld  forth  l»y  MlimuU 
RRccling  ihr  crntrv  iliirctly .  iiiid  ii'il  tiding  on  lh«  u«ub1  altercDl  oorw*. 

§270.  J'rrii'liiUi^  mif-mruln.  Piitliiig  iwiilff  the  Komewluit  complicated 
plinn-ri^oAl  pnrt  of  Hcslntitioti,  Hnd  Itikini;  ihc  awipliugcnl  mi>vi.-inr!nU  by 
tliemsclvra  wo  fiiti)  lh»t  thcso,  tojpthor  ivitii  the  luovemeni*  of  the  etomftcb. 
and  of  the  small  luiil  Inr^o  intwUnCB  ri^bt  down  to  th«  anus  »n  inoro  or  Itm 
alike,  and  mar  be  deHcribed  under  tlie  fteiienil  nnnie  of  "  [tehstaltic  "  mave- 
neota.  We  liave  already  in  §  92.  epokeu  of  th»e,  biit  it  may  be  well  to 
oonaidcr  tljeiu  briefly  at^iii  under  a  ^neral  aspecl,  before  dwelliDg  uo  ths 
Bpecial  niiivetiienis  of  the  severul  purla  of  the  alini«uury  canal. 

The  Riii8(-ular  coat  of  the  allmonlary  t-aiiul  cdu^U,  aa  we  have  seen,  of 
two  layers,  separated  more  or  leai  diHtiiicily  by  a  .ibe«t  of  ciBnectiTe  tiane, 
ui  nuu-.T  ihiiijuT  limt^itudiiml  layer,  and  uii  inner  tliicker  circular  layer;  nod 
aninibtr  iirrun^c-mi^nt  uliiuinn  jti  nearly  all  ihc  luuiieular  hollow  tul)i«  of  tbe 
body,  esocTit  llie  arteritr*,  in  whirh  thu  niumudur  (•k-mvnl^  are  jirtwiit  uot  m 
much  for  the  piir[Mifli-  of  driving'  ihf  blciutl  onward  il>  for  the  sake  of  rCK^iU- 
tin^  the  irrii^aliun. 

Thu  Aclii'ii  of  the  circtulnr  coAt  it  fairlv  itiniplo.  A  c-oninclion  ularting  at 
any  jinrt,  travels  onward  in  (he  Niini.<  dirivlion,  generally  dnwnwaril,  thsJ  it 
III  nay.  from  a  part  nearer  Ihc  numlh  [o  n  part  nwin-r  the  roettim,  for  ■ 
greater  or  lew  di»t»ncp,  the  eircularly  dispomnl  biindk«  ciMitractine  in 
tequvntx.  Tho  result  i*  a  narrowing  or  constriction  of  the  liibc  whidi, 
travclliog  more  or  tcsa  slowly  along  the  tubu,  drives  the  contcnl«  onward ; 
when  a  butcher  emplie«  tho  iiiicvliiie  of  a  slaughtered  animal  by  eciueexing 
it  high  up  with  hin  hnnd  or  with  his  thumb  and  finger,  and  carrying  the 
ec]ne«King  action  downward  along  the  length  of  the  inteatine,  he  makes  tbe 
passive  intestine  do  very  much  what  the  circular  coal  doea  actively,  by  cod- 
traclton,  in  the  liviuK  aiiimal. 

The  ai^tion  of  the  loni^iltidinal  ooat  ia  [terimp*  not  to  clear ;  but  a  contmc- 
lion  of  the  luui^itudiuul  coat  takin);  pluiv  iu  iinv  negnienl  of  th«  tube  would 
tend  to  draw  Ihe  tube  over  tho  contenta  lyiiiti  immediately  abovf,  or  botow. 
ibe  segment,  vnry  luucli  i\»  a  ^dovc  in  drawn  over  u  finder.  And  a  suoeemion 
of  aucii  ciintni(-lic>n»  travelling  alonj:  lh<;  tubu  would  lead  to  a  movcmeHt  of 
thec»nti>i]|.'>io  till' Mine  direction.  WerethecireiiUrcoat  alw-nta  liingiludimtl 
ewat  might  by  it»elf  jioMibly  suliio'  to  jiniiwl  the  enniente  along  the  tube. 
In  the  proflcnoo  of  tbe  circular  coat,  tbe  action  of  the  longitudinal  coat  Id 
any  wginNit  of  the  tube,  if  taking  place  immediately  before  the  circular 
ooalmclion,  would,  by  Ulliug  the  segment  with  contents^  render  the  squeezing 
action  of  the  cimilar  coat  more  emcicnt;  if  taking  place  imoicdiately  after 
the  circular  contnu;tion,  it  would  help  in  quickening  the  return  of  tbe  tube 
lo  its  normal  enlibre,  for  tbe  contraction  of  Lhe  longitudinal  ooot  tends  to 
■borten  and  widen  the  nement,  and  ihna  would  pr«|iare  it  for  new  oonteoU. 
We  can  hardly  imagine  ttiat  the  two  coals  would  contract  at  the  same  time, 
■anco  they  would   lend   to  neutralise  eaeh  other's  action.     Indeed,  we  may 

(irobahly  go  farther  and  aftjunie  that  In  each  j^eguieni  of  the  oanat  first  tbe 
ongitudinal  cuat  ooniracts  while  the  circular  e'lut  i«  relaxed,  and  that  ihea 
llie  circular  coat  eontraeid  while  tbe  longitudinal  rulaxiw.  Wli«n  we  come 
to  deal  with  rc«jiirattuu  we  shall  meet  with  a  MUiilar  double  anlagvmiftic  and 
MCManve  action  belweeti  iiis|>)ntt.»ry  and  exniratiiry  muxclc*;  we  tihall 
fbrtlwrsee  reason  to  think  that  the  proccwioa  which  >iart  the  expiratory  act 
tend  to  check  or  inhilni  tin'  in^pir-iiiirr  act  and  vitt  vertm ;  ami  very  posubly 
a  like  aee-Miw  of  stimulation  and  inhibition  obtains  in  tbe  muscles  of  the 
alimentary  canal. 

Il  must  be  rem«m1)crcd  that  Uic  drcular  coal  ia  alwaja  maoh  thicker 


TIIK    MUSCrl-AH    MKi-HANISMS    UP    U10K8TIM.V. 


:m 


ihu  (bv  laniptiKliDal  cost :  aixl  we  tuny  infer  tbitt  wliile  lii«  chief  work  of 
(triiiitf  tbe  oontcnU  onward  falU  on  itic;  fumier,  thi:  lailL-r  ntuhiB  ihv  work, 
ttlbrrm  Uk  way  ttlik-)i  ut  have  stifcxiatlcil  or  id  wine  otlicr  way. 

ImhoamaU  int(«<tirM-  (he  iul«  iiiliuii^  looiicly  anrl  much  Inisteil.  ^<  that 

■Ufkiopa  arc  formed;  tli«  roDl^uU,  moreover,  are  liirgvly  tlniil.     Hvuce, 

iktmwlj  uDWanl  nxivciiicnl,  ini(.-li  a*  h  aoeii  wWii  more  ai lid  conuniii  pi\M. 

atom  lilt  Mmighl  and  uititvwlini  lirmly  nlCncln-il 'irMi|>liiigiu(,  is  ean)[>ti<'nt<H] 

bf  avMBUtnUi  dao  to  ■  loop  lioiag  proj^'cCcd  forwdTil  by  (lie  entrance  of  fluid 

fii«  a)iuT«,  or  tw-JDi;  driiggt'd  dnirn  by  rhr  wtight  of  it*  tivw  <miiIphU,  or. 

a  ihp  ndirr  hand,  duo  to  a  loop  being  rrlntct^il  by  thr  driving  onwnnl  nf 

iu  niDttatm  and  iIh-  fmntying  of  itwir,  ami  tlw!  like.     Tn  iliiit  way  a  prtruliur 

vrilliing  UHiTrmeiil  <■<*  the  bowrl  n  hronglit  about,  and  thv  pliniM  "  pcristultio 

■nimirnt  "  is  gfn<'rally  uwi)  to  dcTiolv  thia  total  otfcet  of  the  (SHilroetioli 

oftlw  miiKTular  chiI»:  it  will,  however,  be  b4M  lo  r«Mrtet  the  raeani»gto 

Ifca  tm^ rmirv  cnntration  of  lh«  circular  ooat  aaiiBtnl,  in  mmt  ctwH,  by  n 

nnilar  prograaivo  contraction  of  the  longilixlinul  coat. 

(  271.  }tortmeaU  of  tlio  tttophagtu.  I'haii.'.  n>t  we  have  just  said,  are 
fclrlj  uniple.  Th«  cir<'idar  conlraetinn  hogitn  by  the  constrictor*  of  iho 
phvyns  is  codIidiiinI  along  the  circular  iiial  of  the  a«o})hagii«,  and  iisiisted 
DT  M)  accompanying  cMilraction  of  the  longitudinal  coat,  the  direction 
bosir  always,  lave  in  the  abnormal  action  of  vomiting,  from  above  dowo- 
wanl. 

It  will  be  remembered  ($  'ti.2)  thai  the  luuaoular  bundles  of  the  ceeophagua 
ai«  nwBpased  of  HtHat«d  6bres  in  the  up|)er  purl,  iind  of  plain  uiisirLated 
flbreoiIlR  in  the  low«r  part,  the  tran^iLion  occupying  a  difllTeni  level  in 
<lilTrn-ni  animalA.  Nevertht^lcis,  ai*  far  a^  the  [leHataltiu  woveraeot  is  uiu- 
cenxd,  tbe  two  kimb  of  <ihri»  behave  in  the  ttame  way,  except  that  the 
periaultie  wave,  if  we  m«j  bo  call  it,  travel*  more  rapidly  in  the  Mriated 

Thaw  peristaltic  movemcut*  of  th«  a«'>phBgii«  may.  like  thoM  of  the  in- 
llina,  be  aMn  afUr  removal  of  the  organ  from  tbe  body ;  and,  indeed,  may 
oootiaiM  to  appear  u|Km  (timiilniion.  tor  an  iinuiuiil  IcngtJi  of  lima.  They 
tmj,  iWabre,  be  carried  nut  by  the  mufrulnr  dements,  witli  or  witlKHit  the 
balpof  tfat  ncnroua  olemcni*  embeihteil  in  thcni.  apart  fnim  any  action  of 
tb*  MSlnl  SMTOna  ^rtem.  N«vcrthel«H,  in  the  living  bo<ly,  the  movemcnta 
«f  the  naopliagai  anm  lo  )w  tn  a  tpcciul  way  dependent  on  tbe  cciilral  nor- 
vmiaflTat»n;  use  contnicltont  are  not  started  niid  carried  out  bv  the  iralU 
af  Ibe  tube  alone,  and  so  transmitle'l  from  section  lo  sfwtion  in  tbo  walls  of 
tbe  Idbe  itself;  but  aHercnt  impulses  starte<l  in  the  nliarynx,  and  paseing  tn 
tbe  nieilalla  oblongata,  give  liso  to  reHex  etlereut  impulses  which  decceod 
■loQK  nemtu  tneta  to  auooewive  poriions  <}f  the  organ.  If  the  ti^ophagus 
be  cut  acrui  wine  way  down,  or  if  a  portiim  of  the  middle  region  be  excised, 
atimnbtion  of  the  pharynx  will  pr^xluce  a  iterialaliic  ooniraetion,  which 
tra*«nipg  downward  will  not  Miopalche''Ulor  excuion.  but  will  be  continued 
on  into  tbe  lower  diaeonneeted  jxirtiou  by  meana  of  the  central  nervoue 
vpUm.  And  it  is  stated  that  onliuary  j>enMaltic  conlractioDH  of  the  lover 
part  of  tbe  owiiihagu*  can  be  reulily  excited  by  Ktimulatiou  of  the  pliarynx, 
bat  not  by  ntimuli  applied  to  its  own  mucout  mcinbrane.  In  the  reflex  act 
which  thiM  briogfl  MMUt  the  periatallic  contraction  of  the  (Mophariu  the 
alTi-rvnt  nervm  are  thooe  of  the  phar>-nx.  viz.,  the  Nujxiriar  lari-iiKeat  nerve 
anil  pharyngi-al  branchex  of  the  vagus,  brnnchis  of  the  fil\h.  and  in  lome 
•aimaU,  at  Iceat,  brancbe*of  ibc  gludBuvpharyngml.  but  childly  tlip  ttrtt ;  and 
OBOpbageal  mofeinenui  can  cu.'uly  be  cxciml  by  centHjHtal  •limulation  of  (he 
anperiur  laryngeal.  The  oenire  li«t  in  tbe  ninlulla  oblongata,  iHiiiig  a  part 
of  tbe  general  dcgliititioD  centre;  and  elTervnt  iiupiiUif  pa*«  abmg  librv^i  of 


380 


THK    T[S!fL'R9    AM'    MRCIIA.VISUS    OF    DingSTIOX. 


the  vagus,  raacbiii;;  the  ujiper  (mrl  nf  the  cuophngUA  I>t  the  recurreat  1 
geal  nervei.  and  tlie  lower  (inn.  rhrcmgb  tb«  aetophngealplcxuiia  of  tbo  vagus 
iFia.  70).  Section  of  the  trunk  of  thr  vngiis  n-n'lore  ilitBciiIl  thf  pawage 
of  iOD(]  along  the  ONtophiiguH,  imi]  stiiiiiilution  nf  lh<:  poripbcnil  «tiiinp  caiisu 
ffisophaEt^nl  coin  met  inns. 

'i*)e  liitct  cif  ihix  inovemiiiil  In  ihc  (Mophiigiis  U  considtrriible :  thua  iu  ihe 
dog  K  ball  pulliug  liy  iiu-uns  of  n  inillcy  iigitinal  »  weight  of  'JoO  gntamm 
hiu  bccii  friunil  bi  ]w  reudily  cnrricii  ilowii  from  the  phiirrnx  to  the  Momaeti. 

At  th«  juitucioii  of  the  OMOphiigtu  with  the  itomach  the  circular  fibres 
usitally  Kmniti  in  n  more  or  a  less  norniaDcnt  coadtliou  of  tonic  or  obscurely 
rhythmic  <^>nLriiclioii.  more  particularly  when  the  stomach  is  full  of  foot),  and 
tbtis  M;rvc  as  n  ephinctor  to  prcveut  the  ivturn  of  food  from  the  stomach  into 
tho  a-sophagiiK.  Upon  the  arrival  of  the  bolus  of  food  at  the  end  of  ifae 
CMOpbagiis,  thv  centra  for  Ibis  sphlDcter  is  inhibited  aud  the  orifiM  is  thus 
opwad  up.  Possibly  the  patency  of  the  orifice  is  still  further  secured  by  a 
cnntraetion  of  [he  longitudinal  muscular  6bres  which  radiate  from  tl>e  eud 
cf  the  CMophatn>s  over  the  stomuch. 

§872.  .VovemciiU  of  flic  stomach.  Wlillo  the  obje<t  'if  the  (noohagesl 
movement  is  simply  tu  carry  tlie  swallowed  bolus  wjlh  all  iluc  a(>een  to  ttMi 
stomach,  and  nhile  the  iutaitinni  tnovemeiit  has.  in  like  muiiuer,  simply  to 
carry  the  Jutt«tinal  eontenU  onwiinl,  the  twistLvl  courw  uf  thi-  li>uiit;(j  pmb 
ensuring  all  thu  mixiufcof  thr  c<>n^>tiliii-iit3  of  the;  ontt-nt*  ihnl  may  ui;  nucca- 
Gary,  the  niovvmunln  ai  thu  »t<)inach  lmv<^  n  double  nlijvi't :  on  the  one  haixl 
to  pivividv  an  ad«'<piati-  rxpiMure  of  tbt-  ('huNtiI*  nf  ihc  ililntrd  chamiii-r  to 
the  iulluenct'  i>f  thi-  giiMric  juice,  nnil  <m  ibi  other  (n  propel  the  panialljr 
digeuttil  food,  when  ready,  into  the  diindcnuni,  Wc  may,  accordinglr.  di»- 
tinguiih  between  what  we  may  call  the  "churning"  and  tlio  "propuUive" 
niovvniciits  of  the  etomoch. 

When  the  stomach  b  empty  all  tlie  muscular  fibres  as  vre  have  said,  loufti- 
ttidiniil.  circular,  aud  obli<jue,  fall  iiitc  a  condiiioo  which  we  may  iierhapa 
speak  of  as  an  obscure  tome  contraction.  The  whole  siooiach  is  sioaU  and 
eotitracied,  its  cavity  in  nearly  obliterated,  and  the  muooua  membrane,  owing 
to  the  predominanet'  of  the  circular  c»hi,  is  like  the  lining  membrane  of  an 
empty  artery,  thrown  into  longiiudiual  MAs,  As  more  and  more  food  enten 
the  stomach  all  tho  enam  bucomu  nlaxed,  with  tlie  exceptiofi  of  the  pyl.ino 
aphincler,  which  remninn  at  lin>l  [wrmaneutly  closed,  and  the  lew  marked 
dudiac  sphiocler,  which  nn'rely  rtilnxiat  from  lime  to  time  at  eucli  act  of 
swallowing.  Xo  sooner,  bowrvrr.  do  the  coats  thus  become  relaxed  ihnn 
iher  M.-t  un  olwcnre  rhythmieiil  [lerinlaltic  conlnictioni,  givinv;  rii>e  to  the 
"churning  '  movemenl«.  Thc»e  ninTemtint:<  have  liccn  dcacribral  m  of  such  a 
kind  that  the  eonienl#  flow  in  h  main  current  from  the  cnrdia  along  the  greater 
curvature  to  the  pylorus  and  back  to  the  canlia  alone  the  lemor  curvature, 
•ilbndiary  currents  mixing  the  peripheral  portions  of  the  contiinl^  with  the 
atttn  («ntral ;  it  may  be  doubted,  however,  whether  luty  such  regularity  uf 
flow  i«  marked  or  constant,  and  it  is  not  cany  to  see  by  what  ooiDbination 
and  (c<iuence  of  contractions  in  tho  three  coats,  tongitudinat.  circular,  and 
obliouc.  such  a  regular  flow  caii  be  produood.  But  in  any  cniH',  by  such 
rhyltimical  ooniniciious  the  food  aiid  gastric  juice  arc  rolled  nttout  and 
mixeil  to]*ether.  Tlie^  churoiuK  movements  are  li:t)ble  at  first,  even  though 
tJbe  stomach  be  tilled  aud  distended  b^  a  lar};e  menl  rapidly  eaten;  tfaey 
becooie  more  and  more  prunouuoed  as  digestion  proceeds. 

Before  dignttion  has  proceedetl  very  far  the  "  propulsive "  movomenta 
begin.  Thiiw  occur  nt  inieri,-Hls,  and  are  repeated  at  lir>iC  slowly  but  aller- 
irnnl  more  rapidly.    ICach  movement  ooiisisis  in  a  conlractioa  of  the  circular 


Tim    JIC8CUI.AR    UBCHAMSUS  *>¥    HIOKSTIUN. 


381 


aMNmltf  6brw  mora  powerful  than  auy  taVIng  y^tt  in  l)ie  dmmtitg  move- 
WWWi,  uti  UaAiug  to  m  ctroiiltir  ooiistriciitin  wmoli,  bo;{iuniug  nnpareiillr  at 
■lMiatllioobteurel^<I«fi»«d  gnxivonhich  tiiark^  t\te  iteji'mmti)!  or  iheatilmin 
pylori,  Ifmwb  down  toward  the  iiylorii*,  pmjx-lliD^t  ihr  fnoil  utiwanl.  Tlitx 
toiDVQBtnl  tf  act'omiiniiM  or  nitticr  prvixitiril  l>y  n  rulaxiiliuti  <if,  ihiil  \»  to 
mf,  in  all  |ir>ihal>ilitr  an  inhibition  uf  tho  [H'riniiai'iil  n>olriii:tiiin  (if,  tho 
iMaaUr  pjhm  ilMilt*.  in  ontir  tlial  Ihc  gulric  conU-nU  nmy  piut*  into  ibo 
•MiMWtD.  Itiit  the  urcurrfiici-  of  this  rolnxiuion  it  (ldi;rin:ntvl  by  tho 
OMare  of  tb*  gastrin:  contrnc*  :  Tir  if  tW  [iropuUivo  moTelnl^nt  <lrirc:i  Iafg« 
aafawltd  |>i«cn  tovunl  the  pylnniB,  ilio  >]ihin(rt«r  i«  apt  lu  clow  a^in,  the 
MbR  of  wlii*-Ii  U  that  tho  utidigntcd  tnonwis  are  carried  back  intg  the 
am  bodj  of  the  alonuurh. 

Tba  oorabiiiei)  eflect  then  of  the  churniog  iim)  of  the  propulsive  move- 
MMMa  b,  after  n  certain  pari  of  the  in«al  htu  lieen  r«diice>l  to  n  thick  Buid 
oamUlioa  aomcwhat  rtaemblint;  pea  soup  and  often  called  ohyrne,  to  strain 
rtfflhb  n>are  fluid  |Hirt  into  the  duodenum,  and  to  submit  Ibe  remaJDing  still 
••tlid  piooe*  to  the  further  acliuu  of  the  Ktulrie  juice. 

Am  iligatioil  proceed),  more  and  ni'ire  material  leaves  the  stomach,  which 
»  ibiM  gradiuUIr  emptied,  the  last  portion!)  whicb  ure  ciirri«<l  thn>u^-li  beiu^ 
tbom  part*  of  ibe  fooij  which  are  leant  ilij^tible,  ainl  any  wholly  indij^lt- 
bW  forvign  bivliiw  which  happen  to  have  been  swallowed ;  the  IntiiT  may 
pwrh»|i*  never  U-jivc  tbo  atomacb  at  all.  The  ]>reaeDce  of  food  lead*  to  tho 
dvTcl<ipn«il  of  the  moTetnenta;  hut  evidently  it  is  nut  the  mere  mechanical 
ri-|ili'ti4in  of  tbe  orgw)  which  i*  the  cbum  of  the  movementa.  since  ih«'  stomach 
.»  fiilltal  at  the  banning  when  the  movemcnta  arc  slight.  an<l  becomes 
oa  ibvy  grow  more  forcihlf.  The  one  tbin^  which  dors  iiicrcoao 
•owu  with  the  moremenla  is  the  a(-i<li[y,  which  i»  at  n  minimum  wheo 
tbe  ({^nerallv  alkalino)  IVxxl  has  been  fiwallowcd,  and  increnMS  sl4.-n<lily 
(ttiward.  It  baa  not,  bowever,  been  definitely  shown  that  the  increaaiii|[ 
acidity  is  Ibe  efficient  stimulue,  civin^  rise  to  the  movements. 

Tbe  mtireiDenta  of  even  ii  Kill  stomach  are  said  to  cease  during  slecjt. 
The  ttervoas  mechanism  of  tbe  f^triu  movements  had  belter  he  L-ontiidero) 
ID  coaneetiun  with  that  of  the  iutrntinal  movements. 

(  S73.  lomiViNjp.  lu  a  conscioiu  individual  this  act  is  preceded  bv  leclliigi 
of  tiait*>«,  durinif  whivh  a  copious  How  of  saliva  into  the  mouth  talea  place. 
This  beio)£  swallonnl  carriea  down  with  it  a  certain  quantilv  of  air,  the 
pMHOOe  of  which  in  ili<-  Hioniach.  by  OMsistintr  in  (he  ojienin);  ur  tbe  cardiac 
tpWfltff-  Mihscfiurotly  fui-ilitatcs  tht-  diHcbarjce  of  the  ifiulric  CKinti-nl*.  Tbe 
tMOMa  ia  geDenulv  luooeedcd  at  6nt  hr  iiH-tlectnal  retcbinj  in  which  a  ilcop 
ipaplfllQiTT  ellbrt  U  made,  ao  that  the  diaiihraghni  is  ihruKl  down  a*  Inn-  ns 
pfmtPrfff  agaiaat  the  stomach,  the  lower  nlu  Inking  at  the  hmuk  time  fiircibly 
4nvn  in:  since  durinj;  this  inufHRitor^'  cD'ort.  tbe  gludi*  ii>  kept  chwed.  no 
•iron  enter  into  the  Iuuk*;  but  some  i^  dniuu  into  tbe  pharynx,  and  thence 
prahnbly  deeeeods  by  n  ^uallonini:  action  into  [he  »t<imiich.    U'hcn  retching 

Canon  to  actual  vomiting.'  (his  in^pirauir)'  cflnrt  i«  nun-crdnt  bv  a  sudden  vio- 
(•xpiratar>'oontructiou  oft  Ik  abdominal  walls.tbc  glottis  slill  being  closet], 
•o  that  the  whole  forcn  of  the  cflorl  is  spent,  as  wo  shall  see  it  is  in  deiecaiion, 
in  preMure  on  tho  abdominal  contents.  Tho  stomach  is,  (hcrefbro,  forcibly 
eonprsaaed  from  without.  At  tbe  same  time,  or  rather  immodialely  before 
Iht  ei]dniIory  HTorl.  by  a  conlmctioa  of  its  longitudinal  libres  tbe  oMoiiluifTiis 
is  sborK-nMi  and  the  cardiac  orifice  of  the  stoimich  brought  cloec  under  Ihe 
diaphraj^m,  while  apparently  by  an  inhibition  of  the  circular  sphincter, 
■idtsl  iNrrbapa  by  a  coiilracliun  uf  the  fibreti  which  rwliate  from  the  cod  uf 
tb* OBOphagn orer  the  ttomach,  tlie  canliac  onlicc,  which  is  normally  cloeed. 
Is  ■BBM'hat  nddaoly  dilated.    This  diluliuu  opens  the  way  fur  tbe  cuutenta 


TU£   TISSL'BS    AX1>   MKCUAMSIIS  Of    DICBSTIOX. 


of  the  Btomnch.  wliicfa,  prewed  upon  1>r  tbe  conlractlon  of  the  BtKlometi 
Ui  n  i-erlnin  but  jirubuliK'  only  to  ii  aIi^Iii  extent  by  llie  c»iitr>cti»u  i>f  tba 
gastric  walls,  iire  driven  forcibly  ii|i  iIm:  a*)phagu*.  Tb«  nioutli  b<Hng 
widely  ojjt-n,  aud  the  iicck  Mrvtcbeil  lu  afl'unl  lu  Mnuglit «  coune  a*  (Kwiblu. 
the  vi>init  i.->  rjvt'tt^l  IViiiii  ibc  body.  At  thi»  monieot  there  Ik  mi  tiddilioii«l 
cxiiinitticy  cllort.  wbicb  nvrvcn  to  pnivi-iit  tbi'  vomit  pHsnng  iat4>  ibo  larynx. 
In  uuMit  iiiMa  t<)u  tlir  jiiixti-rinr  pillnn>  iif  ibi;  liiucw  urv  upproxitnatt^t,  in 
onb'r  to  cln«!  Ihr  niwal  piii^n^  ngniiiHt  llio  n«c<rnding  rtnwiD.  TbU,  how- 
ever, in  n:vvn:  vomiting  is  Trcijucntlv  inclH-ctnttl, 

TbiiK  ill  vomtiing  [hero  are  two  ilialini-t  ncU:  the  dilation  of  iIm  citrdinc 
ortti<-v  und  ibo  rxiriiisic  pr<«UTv  »t'  ihr  nbitoniiiial  n-nlU  in  iin  expiratory 
cBbn.  Withoiil  ibf  furmt-r  iIk-  Imlcr.  even  wrhrn  dislrcMtngly  vigoruUB,  tt 
invflbctual.  Without  Uu'  bitter,  u  in  nmri  poisoning,  the  inirinsiT  tuov«- 
iuen1«  of  the  eloniiicb  it<clf  nro  mrcly  otbcicnl  to  do  ntoro  than  i^eci  gas, 
and,  it  luny  be,  n  very  sniiill  <|iiantily  of  tbod  or  fluid.  I'ymeie  or  naier- 
brasb  i«,  howevAT,  probubly  brought  about  by  this  intriiifiic  action  of  the 
alMDiteh. 

During  vomiting  the  pylorus  is  gonemllr  dosed,  bo  that  but  little  material 
eccapea  into  the  diiodenuiQ.  Wben  the  gall-bladder  is  lull,  a  copious  How  of 
bile  into  the  diKxIeuuiri  aeci'iuipanieH  the  act  of  voioiting.  I'art  of  this  may 
lin<l  its  way  into  the  Btoiuucti.  lu  in  bilious  vomiting,  ibe  pylorus  then  having 
evidently  beL'u  ogiened, 

Xbe  uervuuii  uiecbaniaiu  of  vomiting  is  eunrjilicsied  and  in  niauy  asjiects 
obecure.  The  dferent  iiniiulsE's  wbich  ennite  the  expirniory  etTurt  umat  oome 
from  Ibe  respiratory  centre  in  the  lui'dulbi :  with  these  we  shall  deal  in  speak- 
ing of  rcHpinitioii.  The  dilation  of  the  eanliae  orJIiee  h  eau^.  in  inrt  at 
at  leott,  bv  inipuNts  descending  the  vagi,  sini-e  wben  tbcDe  are  cut  real  vomit- 
ing  wilb  lii.irlmrge  of  the  gitstrie  eunients,  if  it  talteo  plai-v  ut  all.  lieeoia«a 
dLmeull  tlimiigb  want  of  rrailinnv  in  tlie  dilution.  Such  inlriiiKit:  n>ov«- 
menlM  of  the  •tomach  w  do  tnlie  |>lKec,  and  the  inoveJnoilH  of  the  u^ipha^s 
■]ip<!tir  lo  he  rarriwl  out  by  the  usnul  uervw.  The  i-iren.'nl  impiilMi*  which 
cause  tlie  flow  of  wiliva  in  ihe  introiluelorv  nauwa  alio  doecnd  nUiiig  the 
u»iiid  nerves  siieh  a»  the  chorda  tynipnui.  ^hetc  various  icapulxcs  ntny  l>eat 
Ih-  i-ouNderei)  sh  eltirllng  from  a  vonuliiig  ctmtrc  in  t^c  tnudulla,  liaving  ctuae 
relations  wilh  the  resi>irntorv  centre.  Tliii'  cenlre  may  bo  oxcitod,  may  bo 
Ibronn  into  action,  in  a  reflex  manner,  by  «timnU  applietl  to  {teripberal 
nerves,  as  when  Toraiting  is  induced  by  tickling  the  fiLiiccs.  or  by  irrilutioD 
of  the  gnsttic  membrane,  or  by  obstruction  of  the  interline  due  to  ligature, 
bemia,  etc.  That  the  vomiting  in  the  la«t  inetimco  is  due  to  nervous  action, 
bihI  not  to  any  regurgitation  of  the  iniextinal  coulcnls.  lA  shown  by  the  fact 
that  it  will  take  place  wben  tlie  iutestine  is  perfectly  empty  and  may  be  pre- 
vented by  secti'in  of  the  meaenterio  ncrve«.  The  vomiting  attending  reual 
and  biliary  t-alculi  is  apparently  also  reflex  in  origin.  \  oniiting  in  fact 
u  rule  i^  a  rvHt-'-v  nclion.  ihe  atlt^rent  impolses  passing  along  one  or  oti 
nerves,  but  muet  fre'iuenlly  along  th(«e  connected  with  the  alimentary  caoal. 
that  is,  long  aflerent  fibn-s  running  in  ilie  vagus  or  in  the  splanchnic  nerves. 
Tim  centre,  however,  may  be  iillt-cieil  directly,  as  probably  in  the  eases  of 
some  poisoBS,  and  in  some  innlmice!)  of  voniitiug  from  disease  of  the  medulla 
DUoiig*t&  Ltutly.  it  may  be  thrown  into  action  by  impulses  reaching  it 
fironi  porta  of  the  brain  higher  up  than  itself,  as  in  coses  of  vomiting  pro- 
duced by  siucllii,  tostw,  or  emotions,  or  by  the  retwilection  of  past  eventa, 
and  in  some  cans  of  vomiting  due  to  cerebral  disease. 

Many  emctica,  such  us  tarinr  cmutic,  appear  to  act  directly  on  the  wntro, 
siuce,  introduced  inb>  the  blood,  they  will  prt)du<«  vomiting  after  a  hlnddor 
ba«  tM:en  sulMtitiited  for  the  whole  utomneh.     Olben  again,  such  iis  mustard 


m 


TDK  Mt'SCt'LAB    MBCUaNISMA  Or   UIGESTION. 


■Ml  wmln.  act  In  >  reflex  maoDer  bj-  irritation  of  the  B:ii*trio  uui'uns  mem- 
branr.  With  ulWn,  aj^iu.  vjIikIi  niu>«  vomiting  by  ■Ivvi.-lrijniig  u  iinii»euuB 
tsM«,  lb#  MFtion  tDVolvts  |mrU  nf  tW  brmtii  higher  tliim  ibo  crntrr  ileclT. 

%  8T4.  ihtt^fiiU  »/  (Ac  tnuiU  inlr^inr.  1  tivw.',  ne  w  have  nlmidy  said, 
ktv  thr  lfpi<«1  p«TUialtio  iiiQVcaMrnt*,  nimpto  except  in  s»  tar  lu  they  ar« 
evniplicsiiil  by  tbo  niatvoc*  of  tbo  iiemicnl  Imipn.  Ihc  [>cciiliar  oecilluiitig 
■M*Miiiriitit  nCnhii-li  appear  to  he  proclucod  cliiclly  by  che  hnf^tudinuJ  fibrea. 

TW  prri)>iallif  m<ivi'iiivnt»,  n«  a,  rulv,  take  phoc  fium  nhovf^  downwnrd, 
anJ  K  nve  liegintiing  at  llie  pylorus  may  he  Iraeoil  n  Ion;;  vrny  ilunu.  Kut 
eantisniui*  uiny,  aiiJ  in  all  proliabilily  occiu^ioitally  <lo,  begin  at  vuriou* 
puiate  aloog  tlw  lengtli  nf  the  inteilicie.  A  movement  Glaned  liy  arliticial 
MtnulatioD  aom«  way  dunn  the  iulesline,  may  travel  not  oulv  ilonuwani  but 
•bti  ii|i«ar<l :  it  hat  been  disputed,  however,  nholber  in  the  living  body  any 
iHlural  haekwanl  (teriataltic  n>oveni«Dt  really  lakes  plaee.  In  thu  living 
budy  tlw  tniNtinee  have  i>eriodB  uf  rest,  alternating  with  periodn  i>f  activity. 
tW  oixurreuce  of  ih«  pertoda  depending  ou  various  circuuutauve* ;  tlio 
■Mcnrity  nf  tbe  inoveinenta  uldo  varies  very  con»i(lcnib]y. 

iS79-  MttnUftU  of  Ihe  l-irife  intetliiie.  Tliew."  an*  fundu  men  tally  the 
MBM  >a  ihoM  of  tlto  •atall  tutcalinf.  but  distiin-t  in  wi  far  il-<  thr  hitler  ceuM 
•I  tl)«  ilvn-opcal  valve,  at  nhieli  itjxit  tb«  Ibrmer  Doruially  bceio;  titty  arv 
Mmp[«r,  ioa*niuoh  ■»  thu  jiendeiit  hKifM  are  abcent,  and  not  m>  vigorotia,  in'oeb 
rvlalivrly  ti  tl>r  dimiiclvr  of  the  tub<-,  tlio  ninount  nf  muwciilnr  fibre  is  Icat. 
Along  tbif  itikifi  *\\rrv  the  Mix-ul!  ar*-  well  ilevelopwi  (§  266)  the  mtivrRient 
nwjr  prrhapa  br  deM-riU-d  iim  aliuoat  inlermillrnt  Irom  wccutuf  lu  Mccuhis, 
tlw  cooteiiU  of  unr  NUTuhie  In-iiig  driven  hv  the  pc<ri«tatli(r  eoninieliotis  of 
ilt  riroilar  lihie»  itilo  lb<>  next  riixuIu»,  wliicb  preparm  to  reeeivo  ibetn  by 
■  ntumtiou  »r  ila  eirailar  ami  a  eiiiiiracrtJoa  of  its  longitudinal  fibres. 

fiiacv  Ihc  li|«  of  the  iltn-ewcal  vulvo  are  placed  transversely  acrOM  tJie 
moum,  nut  ouly  doea  duteusiun  of  the  cnN^uni.  by  &ir«tcliing  the  ruUe  along 
ibe  line  of  the  li[i«,  briu){  them  into  ap[KS)tioD.  but  the  pressure  exerleil  by 
tlM  periMallic  muvenMiui  has  the  same  elfect.  In  this  tiay  any  return  of  the 
caoieiits  fram  the  large  to  tli«  small  intestine  is  prevented. 

Arrind  at  the  u|{inoi<l  tiexure,  die  contents,  now  more  or  lew  volid  feco, 
an  MMMirted  hv  the  bladder  and  the  tacrum,  to  (hat  ih«y  do  not  pniM  on 

S  8T8.  Dotation.  Ih'a  b  a  mixed  act,  being  MuiiuTficially  ib«  result  04*011 
•tfurt  of  the  will,  oiul  yet  carried  out  by  mentis  uf  an  invuluntary  owdianban. 
Pari  of  the  vnluDlnry  elforl  (viusisls  iu  producing  a  jircfBure-elMct,  by  meana 
of  ihe  alnlcimiiial  niuacloi.  ThCM  arc  contraett.il  fnrrilily  an  in  ex|iiratioii, 
but  thr  uhiitis  Iteing  cluaed  aod  lh«  eava)K:  uf  air  fnm  the  liiuif*  prevented, 
(he  wb<i)v  liim-  »f  ibe  premiire  in  hrnught  to  Itear  iia  iht^  ab)h>men  it«elf,  and 
«i  driver  llii-  ei>niciil-->  •>!'  the  drM-t-ndiiig  <<idoii  ounaril  loward  ihc  recluin. 
The  i)>[moj>)  Hcxure  it>  by  il«  )>"*iiion  vlielKirt'd  fniin  this  imssure ;  a  hotly 
intmduivil  per  snuni  into  ihK  i-iiii>ty  r««tuni  is  not  nUhctod  by  even  foreible 
eofiirsriimif'  of  Ihi-  alHloiiiiiial  nails. 

The  arms  is  guanled  by  the  spiiinvtrr  nni.  whieb  is  habitually  in  a  sinte  of 
aoraial  tooic  <x>ulracli'>n,  rapable  of  tieiiig  inervused  or  diminished  by  a 
KJmutiis  applied,  either  iiitenially  or  externallv.  to  the  onus.  The  tonict 
CutUradion  u  in  part  at  l«a«t  due  to  the  action  oj  a  nvrvoas  centre  silunled 
in  tb*  lombor  sninal  cord.  If  the  ttervotis  connection  of  the  sphincter  witJi 
ill*  spinal  cord  be  broken,  relaxation  takes  ptnco.  If  the  spinal  cord  be 
divided  somewhat  higher  up,  for  iiuttanee  iu  the  duival  region,  the  sphincter, 
•Aor  the  deprewing  elfect  of  the  operation,  which  may  lost  several  days,  bas 
pawed  olT,  regains  and  «ibM^|uently  maiotauu  its  tonicity,  allowing  that  the 
tMitre  i*  not  placed  higher  up  than  Itic  lumbar  regioD  of  the  cord.    The 


884       TIIK   TISSLES    AND   UECIIANISUS  OF   UlOBdTlO.V, 


incrawed  or  iliminixbi^il  crmtriicUao  rollnwinft  an  local  slimiiUttoo  U  |ir 
ibly  diMJ  Ui  ri'tlfx  iiu)fin«ntaiioti  or  iuliitiition  of  the  nt-tiou  of  tlii.i  tviilre. 
Tbeveiilrp  in  hImi  xubjeot  to  iiillu«tice6  proeccdint;  from  hivWr  re^ona  of  the 
cord,  Kiiil  from  th«  anlo.  By  tlie  nciioii  of  iIk-  hIJI,  by  einoUon*.  or  hy 
Othrr  iK-rvouK  ■•vfiil*.  th«  luiuluir  »>p)i inciter  i-eiitrc  nmy  lie  iiiliiliit«<l.  iind  thus 
Uie  HpluDctvr  ioclf  rdnxoi) ;  or  atignic-iiU-iJ,  oiid  ihun  ilii.-  sjiliinuriu-  li^liitued. 
A  Koond  ilcm,  Llivrcfure,  of  l)iv  v«]iiiiiary  proem  in  d«r«catiiiu  i»  llw 
inhibition  of  the  liimlxir  aphincttr  cHitn-.  iiq<I  conte<)Uent  reliu(Hlii>ii  of  the 
ejiliinctpr  muffle.  ■Since  lh<'  himlmr  I'l-iitrc  iiiny  ntiiiiin  whcillr  «ffici«iit 
when  Deparatvil  from  iho  hr«iti,  lh<;  imnity^w  i.f  the  "pbiricttr  which  ooeun 
in  cerlfliii  cerobrni  diiciu<c»  i»  iirubiibly  due  I<i  inhibition  of  thi>  lumhnr 
cesirp.  nod  not  to  pKnily>t(t  of  nny  ccrtibrnl  centre. 

Thus  a  voluntary  conlrnction  of  th?  iilMloniinnl  wiUK  nccnmjHuiird  bv  • 
ivlasalioD  of  the  sphincter,  might  prcw  the  conlvnla  of  the  di^>««ndii>g  colon 
into  the  rectum  nnd  out  nt  the  iinii».  8ince,  howoTcr.  lu  nr«  htiTC  B(«n,  iho 
pr«t8ure  of  the  abdominal  nnlls  ie  warded  off  the  cigmoid  Hezure,  such  a 
iniide  of  deJecatioD  would  aiwayi  end  in  Iciiviog  Ibe  eiemoid  tloxure  full. 
Hence  the  DCceasity  for  thcee  more  or  lce»  voluntary  nc[»  beiiic  ncwmpanied 
br  an  involuntary  iiiif;nienlalioii  of  the  peristaltic  action  of  tne  l&r);e  inue- 
ttncsiffTDoid  flexure,  and  rectum. 

In  the  movements  of  the  reciuni  we  cad  trace  out  more  diBlinctly  than  in 
other  reginnii  of  tlie  alimentary  canal  the  wparate  actions  of  the  loo^'iiudinal 
and  drcular  fibres.  The  former,  by  means  of  coniraciioas  travelling  from 
■bove  downward.  Hhcirteu  the  rectum,  nnd  aiiiee  the  auu*  aHbrda  it  more  or 
l<n  flxul  HiijijKirt  pull  the  rectum  uiid  ltd  iwitcnta  down  ;  the  latu-r,  by 
incani*  of  c<iiilnti.-ti<'U!i  tnivi-llin^'  from  above  downnnrd  hut  taking  place 
•umi'whHt  Inti-r,  inirrow  tho  ri'cluin  and  »>  Miueew  thi;  conti!3)t«  onward  and 
outward. 

X)efc(ratii>i)  then  ni>i>cjirs  to  take  plan*  in  the  ibllowin^  manner;  The 
lar;^  intestine  and  »ii;moid  (Icxun^  becoming  more  and  moro  full,  stronger 
and  urouger  peristaltic  nclion  u  cxciled  in  their  walls.  By  this  means  ihfl 
feces  are  ariven  into  the  rectum  and  m.  by  a  eonliniianee  of  the  movemento, 
increasing  in  vigor,  against  the  sphincter.  Thruu>;h  a  voluntary  act,  or 
sometimes  at  least  by  a  simple  reflex  action,  the  lumbar  sphincter  centre  n 
inhibited  and  the  sphincter  relaxed.  At  the  same  time  the  contraction  of 
the  abdominal  iiinecles  presws  firmly  on  the  descendin):  colon,  and  thus, 
tjoulxactious  of  the  levator  ani  awiAting,  the  oonients  of  the  rectum  arc 
Reeled. 

It  must  however  be  remembered  thai,  while  in  ap|)ealiiig  to  our  own  con- 
gdoufnen,  the  euntnietion  of  the  ahdumiual  wallH  aud  the  relaxation  of  the 
irphiucter  t>eem  purely  voluntary'  eltort».  the  whole  act  of  df  fccittinn.  including 
both  of  llieM;  KM-mingly  *a  \-«liiiilary  eouiponeobi,  may  tnko  plan;  in  tha 
abwnev  of  cunaoiouonn*,  and  indt«d,  in  th«  case  of  the  dug  at  IcaiM,  after 
tbc  complete  acvenuKC  of  th«  himlmr  from  thn  donml  cord.  In  auch  amu 
tbc  whole  act  mn»t  be  purely  reflex,  excited  by  the  presence  of  fecM  in  ibe 
rectum. 

S  877.  The  nmviu  meehaHimu  tf  i/attrie  and  intentinal  moivmrntt.  Uotb 
the  (tomach  au<l  intcMinn  when  renitived  from  tl>e  body  and  thus  wholly 
Hjvralod  from  the  central  iier^'ou"  MVHtem  may,  by  direct  Btiniulation,  be 
roidilr  exeite<l  to  movemeuis;  aud  ind-.-ed  in  the  alweoce  of  all  obvious 
otimufi,  movements  which  teem  to  be  fjHintancous  may  at  limes  be  obaerrod. 
The  movements  of  which  we  nre  irpeithing  are  or^lerly  movements  ol^  a 
periataltie  nature,  not  mere  local  contractions  of  a  few  bundles  of  [»Ia[d 
muacular  fibres.  Tlie  alimenlitn-  canal  therefore,  like  the  heart,  lh»uich  to  a 
Ims  degree,  poaseMes  vithiu  itself  such  mechanisms  as  are  re(|uiAt«  for 


TIIK    HtlSOtrLAK    MKCHAN19HS   Of    DIURSTION. 


S85 


I 


mrryixtf  oul  tii  owd  iDoverae»ifi :  itnd,  hb  in  iW  case  of  the  heart,  lli«re  is 
M>  •d«(|iuiu  e?iilenc«  tlint  tlie  gaugliii  scsllem)  in  iis  muscular  walU,  tbwe 
■HDtljr  formtDg  die  plexus  of  Auerbadi,  play  onj  prini«  part  to  (I«velopiuK 
UtCM  HMTemeDU. 

On  the  othrr  bBiiil.  nuui'Hul  movement  of  a  perUialtic  kind  inajr  be 
inducnl,  out  oiilv  iih  wr  Imvo  alrouily  Men  lu  the  iMuphuf^ux  but  alio  in  lli« 
MoBUcb,  in  tbe  sninll  inicwline,  uul  eveii  in  (he  large  inteAtlue  t>y  mimulatiivu 
at  lb«  nwiM  iwrre. 

^W  chwf  and  u«tiit)  c«tif«  nf  the  movcmcnla  of  tivK  Momacli  unci  intiiftincH 
ia  tb*  pnaaooa  uf  fi»Hl  in  ih«ir  iuu-rior.  But  vm  do  nut  know  ilttiuitely  the 
•XMt  manDer  in  which  the  food  prtxiuctn  tbu  niiivemenl.  It  ina^  be  that 
the  food,  bv  stftDUlatiog  ihv  niuous  mcmhrniic.  iwndit  up  BfTorciil  inipulcc*, 
aai)  that  ihne  give  riw  by  tv^vx  action  to  rfr«ri-nt  impuW»  which  deaccnd 
th«  <raff>M  Sitnt  to  MK-ccwive  portioue  of  the  canal,  in  a  niamicr  nmiliir  to 
that  alraady  deacribcd  in  icIVrciicc  to  lh«  u«ophagn«.  If  ihi*  be  *o  tht: 
cflereat  Impalan  rncb  ihr  alonmch  aud  upper  part  of  the  duodenum  by  tbo 
termioal  ponions  of  tlK'  tuo  rn^^i,  Pig.  120,  R-V.,  L.V.,  und  rmch  the  irilw- 
tinea  bjr  Ute  pottion  of  the  right  or  portprior  vagii».  Pig.  1'20.  It'.V".,  nhich 
paNna  islo  Itte  eoliu  plexus  and  tbcncc  by  tbo  mesenteric  Derrce.  The 
fefinvat  itnpulafS  from  the  stoDiach  travel  also  a|>parcDtly  by  the  vagus;  ti» 
{■lbs  of  tfaoae  from  tJ>e  intatines  have  not  yel  been  determined. 

Itut  that  !ucb  II  reHex  action  tbrou^ih  vagua  fibres  ia  not  the  only  raeana 
W  which  the  jmecnce  of  food  brin^  about  the  tnorements  in  (lueatioo,  la 
iMVn  hy  the  Act  that  thcee  continue  to  be  developed  after  seistion  of  both 
ngOB  nervca.  Probably  ibe  whole  action  la  a  mixed  one  which  we  may 
pkUm  to  ourselves  somenbat  as  follows:  The  alimeuUirr  coiial  poMeaaee  a 
M««r  of  Bpunlaneuus  n»venient,  feeble  it  is  true,  verv  Inferior  U>  thai  of  the 
bnn.  and  vvn-  apt  to  bt:  Ut^'nt,  but  still  existing.  The  prfwcnoe  of  food  in 
•aoMi  way  or  other,  by  M>m«  dirrct  action  quite  apart  from  the  central  nervous 
^auoi.  u  able  to  inereaM;  this  |>owrr  mi  that,  without  any  aid  from  the  central 
nervous  system,  as  after  M>clion  of  the  va^,  adequate  peristaltic  movements 
van.  uudvr  favorable  circumstances,  Im  carried  out.  Nevertheless,  in  the 
Dcirnal  roorre  of  events  atisfactory  movements  are  dill  further  secured  by 
the  retlex  sction  through  vagtii  fibres  just  described,  llius,  in  tlie  dog,  the 
•M  of  swatUiwiuf;  fiKid  or  even  the  mere  smell  of  fo<id  has  been  observed  to 
imnaaii  tiie  niovemcDt*  of  ■  piece  of  intestine  isolated  from  the  rest  of  the 
aliOMBlarv  coimI  but  retaining  il»  coniiectious  nith  the  central  nervous 
^ntMU.  tinder  this  v'kd  the  perintallic  niovenienlf  produced  by  centrifugal 
■dnulatiou  of  the  vagu^  in  the  neck  are  comparable  not  an  much  with  the 
eenuaotion  of  a  skeletal  muscle  wWn  its  motor  nerve  ia  stimulated  as  with 
tbe  beats  which  may  be  called  forth  in  an  inhibited  or  otherwise  quiescent 
bout  by  stimulation  of  the  cardiac  augmeiitor  fibres. 

Indera.  we  may,  perhaps,  call  ibe  ra^s  fibres  uhicb  pass  to  the  stonaob 
sod  lottatines  (and  time,  we  may  remark,  are,  like  the  cardiac  augmantor 
Hbre*.  non-medu Hated  fikr«*  along  the  urtUtr  part  of  their  coiine)  aaa^ 
iB«Dt«r  flbrea  rather  Ihsu  motor  Dbreit.  We  have  all  the  more  rvasoo  tu  do 
ID  sliwe  tbcn  exist  conniauion  but  untauionifttii'  iiihlbitiirv  fibres.  If  while 
lively  peristaltic  action  is  goii^  on  iii  the  t>oneI*  the  i'plnnclinic  ncrvt*  he 
Miinulatrtl,  the  l»wclii  are  brought  to  rtsti  often  in  u  very  abnipl  nnd  marked 
BMincf.  Inhibitory  fibn-a.  thcri'tiirr.  run  in  the  splanchnic  nerves  ( Fig.  1'20, 
UpL  maj.  aud  mrN.).  paM<ing  nlotig  ibi-ni  iVoni  thotpinal  con)  to  the  abdom- 
iaal  pleKUseS.  and  tbcncc  to  ibc  alinif-nlnry  canal :  probably  some  of  tbo 
tiM  Bitdlilleted  fibres  which  may  be  obecrved  along  thin  track  ar«  of  this 
Dalnrs- 

It  will  be  noticed  that  tbn  splanchnic  nerves,  while  cootaiuiug  vaao-oon- 


886        THC    Tti^Kl-KS    AND    UECII ANItiUd    OF    DIQKSTIOX. 


Rtricl'>r.  I.  P.,  augmeDtor,  fibres  for  the  blooilveaaela  uf  the  itilestinua,  cmrrw 
inhibitory  fibres  for  the  luuscular  vDat;  aud  [trobaibly  the  rogiM.  whiU  doo- 
Initiing  niicnientar  fibred  Tor  the  tuuamilar  coat,  nrries  iohibitorv  dilator 
fibrai'  for  the  bluodvmiieljL  It  mtiv  further  be  rumurkeid  that  ttw  vagns, 
vrbile  eupplying  an^tiK'nt^ir  fihruo  f()r  ibi'  niiUK-ulnr  iiienUttniain§  of  the 
aJimontarj'  cnoitl,  eiirrits,  tt»  we  so  wttll  kn<itT,  inliibiturj-  fibres  for  tli.j 
cardial-  niusaular  ii]cc.hiu)i«in. 

KI6-1W, 


RVi 


LV 
-pi 


"0*.pl. 


i-^D,6 


..pi.  hyp. 


Lr 


Rst. 


DlAOSlH  R>  ILLISCUTI  Tn>  NKRVW  OF  mi  AWOonutV  CtMAl,  »  Tin  DOD.I 
Tb*  l>ura  !•  fur  Ihe  wJib  of  midpUcKjr  maAQ  u  •lluicminnuitk  u  |iciMbI*.  ami  itaa  KM  rqin«W~ 
Uc  amila«iiq<  rdnKnu.  i~>v.  bi  I(c4.  TliDftllinanUryMriiLl,  >i-»i.hiu(ii>.>l"iiuicli.aiiull  lni««U(ict,l)U|* 
UiMUd»,  raMiuL  LV.  I.enii*8»*ii>-rr(i.  •iiilliiir<iii  rr»>lnr>lovuu<h.  rl.  leciirmul  UrjrnvMl  Mr** 
ninl)rlncBpi«Tt«neCaaophBfni.  tt  V.  KIbIiI  TOciuJolnliielcA  nKiwIii  <i>->ii)i>Bi«)pl«Kiu,  oe. 
tl->  niiJilrUiB  tbe  poattfrfot  |«tt  nt  •loitiadi  uiil  contlntinl  *•  K'.V  tojiin  the  mUr  ptaRHi.  Stn 
npramtnllvaiditMiniWlMnan'IrnnnwiwI  wlili  Uw  Infrrior  innHicnc  iruiclliiti{iitplri(ui  m.al. 
— «.  bnuwtiM  ftiMn  UiOKibu  pluiuloiMuuicliitadnniLll  lalcMlno,  and  fluiii  il;v  mivgnlalc  m^ioa 
Ulha  lam  IntoUne.  !^pl.  nu)<  Ittw  ■I'Iui'^bIob'**  *'t*'"ll  '''ooi  Itic  thorBrtf  caiictlt  ami  ninl 
MMSMiiiicaiila,  r.CL,  Iwlonalag  lo  dniml  u*m*  from  ine4lh  lolbeSiliior  lliilil  .^jil,  mln,  «awtl 
■pMachnlr  lunxr  tlmllarljariilBf  Itom  IMImnd  llili  ilonal  iierv**.  TbuwtullitaintlieHilttr  |>kia> 
■ad  UirfKD  make  Iboli  «a]>  lo  (li»  ollmanUf}  ouiut,  Cc  NtrrM  (Tom  lli»  (■nulla,  «(f.,  bclan|ln( 
MllikuMl  mil donal and  |<|  anil  :U  iiimtar  atmt.  |>nxvt>Unc  MibelaJbrtat  nwviiMrir  ta^Ua 
lOcptHOi).  n.  s>.,  anililicncatqr  UMbnoCuMc  nerve  ii.hrp.  anil  lb*  lijrponalrlo  pl*iila  |i.  liJii 
Is  thi  dKiOar  niEiKl«  of  (ba  iwciuni,  1,1,  Ktmt  fcim  Uia  Ud  aad  M  matl  cenat.  »■.£.  aU  invrl 
M||»nuu,  i>n>ti*tdlu(  tr  ibo  nn>i««*rtc  tAtxm  to  (be  laiMtHndlual  Budaa  «f  (h«  rMtna. 

In  the  abovp  ttmcuii'iit  wp  hnvt  purjimii'lr  ii»oit  thp  general  term,  pori- 
etallic  HMVcnM^Dt;  but,  m  vk  hart  •oou,  in  the  muvemenU  of  lh«  aliiDenury 

I  It  SH  DM  ntwnai  niitll  loo  laio  Am  Iu  ■b«<lU<niiBol  ih»  nuTMnr  iha  allUMiilarT  euial  In 
<!•  d«i,  Mm  dorwl  noiTM  bad  lucn  npMnaM.  TBo  Os"'*.  ■«  tuwd.  makoa  nu  pxctciic*  M 
■aauMlnucmMnaB:  but  li  would  tiara  taa&bKWr  id  rc(irsaiit^iIiurUiUtteaurafii«a|im|11Q 


TUK    HL'SCUI.aR    MECilA.VlSU8    Ol'    DinKSTlON. 


S67 


^^  AHL  two  Ma  of  uusoles  are  coacerned — the  circular  iind  the  lonj;itu<liiiaL 

P      lfW|b  tbe  rectum  we  are  able  to  recoguiie  that  tlie  iwoacUuf  inusclM 

r      bvtwlu  tliMiDct  iii-n'ouB  aufipliw.    Tbe  looptudinal  coal  is  goveniwl  hy 

I       iurT»>fibmi  «hk-)i.  ill  ll>c  Acyg.  leave  tlie  anioal  cord  iu  the  anterior  riM>u  in 

I       cJi«  arcuod  anil  tliinl  Mcral  ncr\'<at  Fif:.  I'lo.  ■S2,>$3).paaB  along  the  branobea 

I       of  ihuK  oorv»  frL-iiuetilly  ximken  nf  aa  the  ii«n'i    erigettiet,  I.  r.,  to  tli« 

I      ImngMtrie  pleiw,  {pi.  A^j.>,  and  Ihciire  to  the  rectum.    StimulatioD  of 

I     IMM  nmta  cnuaoa  contmciion*  of  ibt:  n^clura.  which  are  conIiDe<l  to  tba 

I      loagtttidinnl  ami  aud,  w  vm  huxc  .-aid,  pull  ibc  n^'ttim  duwii.    The  circular 

SMI  U  piTVrTH'd  liT  ti)irc9<  which  Ivavo  Uw  opinal  conl  by  lh«  anterior  roola 

of  Ibv  lower  dur»al  and  lirrt  twn  lumbar  nrr%'i«,  Fig.  121)  (coming  fWtm  the 

luwwr  |«i1  af  that  »)iinal   nngion  fnm  which,  lu  we  have  *ec»,  §169,  the 

Tan>-c(>iii>lniHor  l)tin«  take  origin),  and,  nirly  Iwin^  their  incduUn,  pwv  to 

iiim  r«eium  by  ilio  inferior  incsicnteric  sanglia.  Ihc  liypii^iric  ncrvva,  and 

''fP'^KUtrir  pIcxuM  ( Fif;.  120,  iit.  i/L.  n.  hi/p.  pi,  hijp.).    Stiniijlalion  of  th«ae 

'twGM  give  rifv  to  roftlfacti»tis  which  are  confined  lo  the  circular  cimt  and 

^I'li  !■  mil  Ibe  oonieDUof  ihc  r«cluni.     A  Rimilar  double  nervoiii  tiipply 

ivotkably   goverot   ibe    lunj'iludinal  and    circular    cont*    along  tho  whole 

■IllavnUrr  caiial ;  but  the  delails  of  »ich  a  supply  nrv  at  present  unknowu. 

Otir  konwIedKc,  nioreovfr,  oouccmint;  the  details  of  niiy  special  nervous 

^^^lianienw,  bv  ineaiiB  of  which  tbe  more  complicnted  movements  of  tbe 

*(»ntiirit.  tnt.-t(idiDK  the  cloeiii;;  and  opening  of  the  »nhiDct«re  are  mrried  out, 

"  •*!  j>reti«nt  very  imjwrfevl.     We  cannot  add  to  what  we  have  inddeiilnlly 

*'*J  m  speakinjc  of  vomiting. 

1*lie  moTements  of  tbe  rectum,  including  the  fei(;moid  Heiure,  appear  to  be 

''\'*<^b  niure  chwely  dejiendeni  on  llie  ceutnd  nervous  system  than  are  tboM 

?f    the  real  of  the  aliraeniarv  ouial.    As  me  have  Mitd,  the  moveinenta  of 

^**-t)  btrge  and  nnall  iotwliDC  are  rallter  aaualed   and   augmented  ibtB 

f**ciMrily  otllcd  forth  bv  impulttcs  dvc«ndiiig  from  the  centra]  nerrooa 

T****!  Mong  tltc  vagus  fibres-     A*  ibc  large  intestine,  however,  pnssM  into 

~^*  rectuiD.  giivcmment  by  Ibe  vagus  is  replatwd  by  govemmrnt  through 

^^^  lomlMir  cord  and  tbe  nerves  jtwA  previously  meolioned :  and  this  goveni- 

I  ^*^«at  apiiears  to  be  not  so  much  mere  augmentation  as  the  actual  carrying 

I  V^tt  of  the  ntovenients  through  reflex  iiclioii.     Hence,  this  is  tbe  pari   of 

^lit«e|ina]  tDOTcmenl  which  fails  iQ  dlMasca  of  the  central  nervoii*  system, 

^)ie  failure  leading  lo  obstinate  cooMipation,  if  not  lo  nclual  dilticulty  of 

^sfeotion.     Tl*e  presence  of  feces  in  tbe  sigmoid  flexure  no  longer  etir*  up 

ife  icAex  inechanifiii  for  their  di^liarge;  meanirhile  the  more  iodependGut 

■OTeatents  of  the  higher  [wrts  of  tbe  canal  oonlinue  to  drive  the  contents 

Mwanl,  and  hence  the  fcMti  accumulate  in  the  sigmoid  flexure  and  colon 

svmiling  the  delayed  action  of  the  imperieot  reflex  mechanism.  Witli  refpo^l 

to  the  exact  manner  iu  which  the  |>feseiKe  of  (bod  acts  as  a  stimulus,  it  may 

bt>  iioith  whik  to  reninrk  that,  althuujth  in  tbe  »lonmch,  aa  we  have  seen, 

nnv  fiiliKiw  i*  not  the  efficient  ratue  of  the  movenieiita,  vince  thete  lieeomo 

tDum  active  as  digealiom  proceei)*  and  iIh-  bulk  of  the  cnntvnls  dimininhi^ 

»y(4  in  the  iniestioe  distention  of  the  bowvl  up  W  cerlain  timiln  mu.i  di*- 
linetly  inoraaMS  the  vigor  of  tl>e  movotumitd  junt  ax  diiitenti»ii  of  lh«  canliiu: 
tBvitira  oitbin  certain  limits  improvw  itte  cunliac  Mroke.  Thi*  ii«  wull  ntn 
in  nhttruriinn  of  the  bowcU,  in  which  cnsoi  tlie  buwul  dt*u>nde(l  nhovc  tbu 
nlwt ruction  is  frciiiiently  thrown  into  violent  pttrirtnllic  iuuT«ni*Dti>.  This 
tdMl  i*  in  part  nt  lea**  rlue  lo  Uic  distention  exlvn<ling  the  niucalar  Hbr«, 
bmI  mi  in  a  ilirect  niDnner  promoting  thc^r  contraction  (■•0  $11).  but  may 
be  ill  i«n  due  lo  au-'iiK-nior  impulses  excited  in  a  reflex  manner.  Probably 
hi  an  inte^iufl  isolated  front  the  central  nervous  system  f-xnl  provokes  jieri- 
lUltie  DKivenieuta  much  more  by  causing  ilistcniion  and  »t  elreivhing  the 


388        TllK    TISSl'ES    A.VO    11  EC  II  A  N  liillS   OF    DIOESTIOjr. 

muwular  (^^ais  tban  by  acting  as  a  slimtiluH  to  the  mucout  nietnbnitc,  eiilter 
ilifDUKli  eliGmk-iil  octioD  or  in  May  siiuilar  nay. 

tj  278.  Next  to  the  presence  of  food  in  the  interior  of  tli«  alimeuiarv  cons 
a  d«llcieiit  oxygeualion  of  the  blood  tiu|)tili«d  to  tbc  walls  of  the  cuoaf  or  ili 
kudden  cutting  off  of  the  aupply  of  bloml  may  be  n-jpirded  u  Ibo  mont  i>uitfr* 
rul  pfovomtirea  of  peristaltic  uctiuu.  Wbeii  tbu  iiorta  U  clamped,  or  wlm 
tbc  r(«piratioii  in  ii«rioualy  iuterfer^i)  nitb,  pcri«taldc  niovemcnl*  bccon 
rery  proiiouuccd.  Thiin,  iii  dvath  by  HHpliyxIn  i>r  :<til}i»uUt»ii,  aii  tnvulunlai 
diM-liar^  of  IV-Cc*,  vrliioli  i»  in  part  at  lcu«l  llit-  midt  of  iacreoMd  paririalt 
artiun.  IN  not  an  unfrciueJit  mult;  and  ibv  niark<Hl  peristaltic  movcmioti 
which  an?  to  freiiuciitiy  w-i^ii  in  an  nnimni  when  the  abdomen  is  laid  ■ 
imniediftlcly  al'trr  di-alh  apjtcnr  In  hi-  du<-  to  the  cuMntioD  of  the  circtilatioa 
and  llio  conttcniicni  failure  in  the  supply  of  blood  to  the  trails  of  the  aliruen- 
tary  canal,  and  U'jt,  as  hiu'  been  i>ugef«led,  to  the  contact  with  air  of  the 

giritoOffll  stirfuec.  Since  it  is  bloixf  which  brings  oxyg«n  to  the  tiesuea, 
ilure  ID  the  supiily  of  blood  is  tanlamoiinc  to  failure  in  the  etipply  of 
oxygen ;  but  the  blood  current  brings  other  things  besides  oxygen  and  aUo 
takes  thing's  away :  nnil  the  failure  of  this  action  also  probahlj',  a.*  nell  as 
failure  iu  the  supply  of  oxygen,  provokes  the  luoveincnie  in  question. 

The  movements  iIiiie  producer  are  to  sonic  exlenl  the  result  of  the  defi- 
cient fiupply  of  blood  acting  directly  on  the  walls  of  ibe  canal,  tliougb  in 
a#jihvxiii  at  all  events  ibis  etfect  may  be  iucreaited  by  the  ton  venous  itla 
atititulaiiiig  the  central  nervoua  system,  and  thus  sendtug  aiiguienlor  impul 
down  the  vagus. 

Wi[b  regard  to  the  mode  of  action  of  tlie  drugs  whidi  promota  periMullic 
action,  it  will  be  HufBcient  here  to  eay  thai,  while  some,  such  as  niooUn, 
appear  t«  act  dircellv  on  Ibe  walls  of  the  canal,  others,  such  its  strychnia, 
prodiici:  their  etlecl  chietly  by  acting  thnmgh  the  central  oervuiis  syMeni. 

Tbb  Obakoes  which  Ttii^  Fuun  L'kukuoue»  ix  tik:  At-iMEMTARr 

Canai- 


$879.  Having  studied  the  properties  of  the  digestive  juices  es  exhibited 
out^cU)  the  body,  and  the  various  mechanisms  by  means  of  which  the  food 
introduced  loto  the  body  is  brought  under  the  itidtietice  of  those  juices,  wa 
have  Doa'  to  consider  what,  an  nmtU-t«  uf  fact,  are  the  actual  changea  wbich> 
tliu  food  does  undergo  in  passing  ahmg  (be  alimentary  canal ;  what  are  tha 
steps  by  wliji-h  the  eontenta  of  the  canal  are  gradually  converted  into  (temi\ 
The  events  which  lead  to  this  conversion  are  twofold.  On  the  one  hand  th*' 
digestive  juices  do  bring  alioul,  inside  the  alinivntary  canal,  change*  trhich 
in  the  main  are  tbc  nnie  as  thoiu!  olxrrvi-d  in  laboratory  cxpcrimcnU)  outside 
the  body  and  described  in  previous  .locliouti,  though  the  refulU  arc  somewhat 
modified  by  Ibe  ^{iccial  condition*  which  obtain  ffltliin  the  body.  On  the 
Oilier  hand  absorption,  that  is  to  say,  the  patwigc  from  tlic  interior  of  lite 
canal  into  the  bltRidvcsscls  and  lymphatics,  of  digt^tcd  mut«-rial  in  oomnany 
with  water  is  going  on  along  the  whole  length  of  the  cnnal,  and  (vjiccially  in 
tbe  sn>all  and  large  intcslines.  It  will  be  convenient  lo  conRnc  ourM'lves  at 
present  to  the  study  of  the  first  claas  of  events,  the  cbangvs  eflectdit  in  thii 
canal,  merely  noiini;  the  disap{}ea ranee  of  this  or  thai  product,  and  di-fvr- 
ring  the  dilftcuU  prublem  of  how  abeorjHion  takes  place  to  a  sulwequetil  and 
separate  discussion. 

in  thf  nwvtK  the  presence  of  the  food,  anisled  by  tbo  movements  of  the 
jaw,  cBusea,  as  we  have  seen,  a  flow  of  saliva,  ily  mastication,  and  by  the 
addition  of  muuous  saliva,  the  food  is  bivikeu  into  small  piocos,  moistened, 


I 


389 


I 


I 
I 


■ad  ntbrm]  into  a  onvcRimt  holti*  for  ilc^liilitinn.  In  initn  Kimc  nf  the 
Marea  »,  even  iIuHiij;  lli«  fUnn  »liiy  of  ihc  fo™l  in  thu  mouth.  (.■unvKrtctl 
iota  Migar ;  for  if  ImiM  rtnrch  frer  from  mgnr  be  even  inDitivnlnrily  helii 
to  tb*  mouth  Biiri  then  rjcctcd  into  nnt4-T  (kept  lii>iliiig  to  dvstror  ibe 
fiiraHnt),  it  will  Iw  funnd  to  conuiin  ti  decided  ntnonnt  of  siiiinr.  Id  many 
utiaiAk  DO  (udi  t'buag«  takeit  place.  The  viscid  ealivii  nf  the  dog  «ervM 
alnm  solely  to  urist  iu  degl'iti'''"!  i  "ix^  ^v<!i  ^^^  longer  «tny  which  food 
mrnknt  in  Ihe  tnouth  of  tbe  noree  ii  inBuflieient  to  proditee  nny  nmrkeal  am- 
fWlluu  of  Ibe  March  it  may  contain,  Inuring  tbe  rapid  inmeit  through  the 
MmiAd^tu  no  appreciable  chanee  lakes  place. 

Tlie  Biuouiil  of  iibsorplion  of  dignteii  inatertal,  or  even  of  aiinplo  n'Oler 
flfmn  tbe  mouili  or  oasophaRUB,  inust  always  be  iofliKniBcanl. 

7%«  Chaa^  IN  the  Smnaeh. 

i  880.  The  nrriviil  of  the  food,  the  rwictioii  I'f  which  in  either  nnturnitv 
alkaline,  »r  ii  made  nikaliiie,  or  at  lead  is  reduotnl  in  addity,  by  tho  oddi- 
liea  of  Mliva,  miw*  a  flow  of  gastric  juice.  This,  already  cniunittnciog 
while  the  tonl  i«  yet  in  the  mouth.  iDcnvises  an  the  food  nccumulstn  in  the 
alnumeb,  and  aa,  by  tl>e  chuniiiig  giLi>tric  moreniQiits,  one  part  after  another 
of  the  firad  is  brought  into  contiict  with  llio  mucous  membrane. 

Tbe  chanctefs  of  tbe  juice  appear  to  change  somewhat  as  the  net  of  digee- 
twm  proceeds,  The  amount  of  popsiQ  in  thp  gastric  <xiat«nts  increases  for 
MOW  time  after  food  is  taken,  aud  probably  the  actual  secretion  increaMa 
•Iwk  Tbe  acidity  of  (he  gastric  contents  is  at  first  very  feeble :  inilee^l  in 
nan,  la  some  cases  at  leait,  for  some  little  time  after  the  beginning  of  a  meal 
DO  free  acid  is  present,  and  during  this  period  the  convereion  of  starch  into 
■ugar  may  coiitinue.  Thi»  condition,  nowever.  i»  temporary  only;  very 
won  tbe  oontenu  become  acid,  arrMtinc  the  action  of  and  ultimately 
dMtloyiag  the  amylolytic  ferment ;  and,  *!nce  the  nit«  of  »ei-retioii  of  acid 
appean  to  be  fiiirly  i-nnttant,  the  contents  of  thf  xtnmacb,  unlea  fre^A  alka- 
line fitod  be  taken,  bccnnie  more  add  a*  iligiMtion  goes  on. 

The  graa  eBect  of  gastnc  digestion  is  to  hn-ak  up  and  partly  t»  di<«olv« 
the  larger  luBim  of  nHtttcated  food  into  a  thick  grt-yiih  Hiup-like  liqtiK) 
called  fliynw,  with  which  arc  itill  mixed  in  variable  <jiianltCy  Urnr  and 
smallar  naans  of  len  changed  foml.  This  is  the  nwilt.  partly  of  Uie  aolu* 
UuB  of  imXcid  miilt^Ti,  partly  of  the  tolution  of  the  gelatiiiiforoaa  eonoec- 
tin  ti«ue  hutiling  the  nroleid  elemente  lognlher.  In  a  fragment  of  meat, 
for  iniitanee,  the  muscular  fibres,  through  the  solution  of  the  oonncctive- 
tiMue  binding  tliem  together,  fall  asunder,  the  sareotemma  is  dissolved,  and 
tbe  tibr«  themselves  split  up  sometimes  longitudinally  but  most  frequently 
by  transverse  cleavage  into  discs,  and  are  ultimately  more  or  less  reduced 
|Mrtly  into  a  granular  mass,  partly  to  actual  solution.  In  a  piece  of  tissue 
ooDlatning  (M,  the  counectivo-tiasue  bto'ling  the  fat  cells  together  and  tbe 
oovelopee  of  the  fat  eelU  are  dirsulveU,  so  that  the  fat,  fluid  at  the  tempera- 
tore  of  the  budv,  is  set  free  fVom  the  individual  cells  and  ruiu  tojcethcr  Into 
larger  and  nnialler  roaaies.  In  vcg^'i-tnlile  tiaaue  the  proicid  etementM  are  iu 
part  diMolved  and,  though  there  it  no  evidence  that  tn  man  vellultwe  i«  dis- 
solved in  Ibe  siomacb,  the  whole  lUsue  is  softened  and  to  a  certain  ettenl 
disinifftated.  Milk  b  curdled  and  the  curd  subeequeoily  more  or  lesi  die- 
solved. 

Til)?  thick  w<i|i-liko  arid  chyovc  cuuisU  acoonliugly  parilv  of  HitwIanoM 
which  have  entered  into  artoal  w>hiiion,  partiv  of  mere  particles  or  droplet* 
of  proteid,  fativ  or  nlhfr  nsiun^  and  partly  nt  manes  imall  <>r  ifreal.  wtilch 
may  be  rrcogniwd  under  the  inii*r»»ci>|>c  as  more  or  le«  changisl  poritoai  of 


390 


TBB  TI98UBS   AND   MBCHANISMS  OF  PIOESTIOI*. 


niiiuuil  or  vc^dublc  liiwiii\  Tlic  muouut  t\f  niiiUTial  ui'tuitllv  iltoKiIrcil  ui  in 
BUM  flpAciDK'nH  i>t'  chyme  vxcceilingly  niinll.  Wbcii  ihv  luiliil  piirta  ore 
roinijvril  by  flllnuic>ii  tho  clair  fillriilv  c-uiitniiiii  li(«i<l<«  nlu,  pcnnn  uml  free 
hjr<lruchloric  iicid  (ihit  <-i>mIt[iii.'iil»  of  the  gulric  juice),  a  «miill  aiaoiiDi  of 
nigsr,  of  pantpoptonc  nix)  of  ptrptono.  The  sugnr  ui  oftr.ii  ndfCJit,  tbc  pnrm- 
peptonc  is  nol  alvcuvs  present,  nnd  th«  umounl  of  peptone  (or  ulkumuM)  )■ 
alwny»  ymM. 

Duriii);  gastric  <lig«etton  tho  chyme  thus  forin«<l  is  fram  tiin«  lo  tiaw 
ej^clciJ  ihrough  the  pvioriit,  ncoonipnuicd  by  oven  )>t^  morwls  of  sulid 
let«-(ligr«ted  matter.  "I'hia  may  occur  withio  a  fow  iuitiitt««  of  food  having 
be«ii  laken  ;  huC  ibe  larger  escape  frt>ni  the  sloinach  probably  iJnes  not  in 
tDan  begin  until  from  one  to  two,  and  lasts  from  four  to  five  Iioim.  after  ths 
meal,  becoming  more  rapid  toward  the  eud.  and  such  piec«e  as  are  tlie  kut 
broken  up  by  the  gaatnc  juice  and  movomenia  bein^;  the  laat  to  leave  Ibe 
stomach. 

The  time  takvu  up  in  gaatno  digeatton  probably  varim  in  the  rtame  animal 
not  only  with  diflereiit  artii-les  of  food  but  aUo  with  varying  cimditioas  of 
the  stomach  and  uf  the  IxHly  at  large.  lu  ditlerent  aoimaUi  it  varies  verr 
const dcnihir.  being  from  twelvL-  to  twenty-fiuir  honn  in  Ihr  dog  after  a  ftill 
nul,  whilu  ihf  xtomuehii  (if  rahbit.i  an;  never  empty  lull  alnrayN  remain 
largely  fillt^l  with  tixid,  itvMi  iluriuj;  starrtition.  la  nuui  the  (tumach  proba- 
bly becomes  cmjitv  bclwoi'a  ihi:  iinunl  mcaln. 

The  total  amuiinl  af  ohaiigK  which  the  fnod  iindergoM  in  the  stomach, 
ibst  is  the  share  lalci^ii  by  iho  siomach  in  thi-  whole  work  of  (ligmtion, 
Mcms  to  vary  largely  in  diflcrcut  antninU  and  in  lh«  same  animal  dinbn 
acconling  to  thi'  nature  of  the  meal.  In  a  dog  fr<l  on  un  oxclnsivlv  meat 
diet,  a  very  large  part  of  the  diucstiun  i*  »nid  to  he  carried  otii  \ty  the 
Stomach,  very  lillle  work  upparenlTy  being  lell  for  the  intwtines;  that  is  to 
say.  tho  larger  part  uf  the  meal  ib  re<luced  in  the  itiomach  to  actual  solution 
and  a  cuDiiiderable  'luautity  h  i>rol)ahly  abxurlied  directly  from  the  Mouiach. 
In  such  ctiscs  rhe  amount  »f  jieptone  found  in  ihe  Htomaeh  during  the  digea- 
tion  of  the  meal  in  found  li>  lie  fairly  couBiaiil.  froai  which  it  may  be  in- 
fltrrcd  that  the  itepiuiK*  is  aliMirbed  ua  soon  a^  it  is  fonued.  There  is  also 
evideuce  that  fat  may  ti>  ii  cerUiin  extent  undergo  in  the  Hlomach  chauga 
leading  to  emulsion,  .limilar  lo  lh<i«e  which,  as  we  shall  see,  are  carried  out 
in  the  stuall  inintine. 

But  such  ciises  ns  thtw  cannot  be  regarded  as  ty|>ictt!  caiu'ji  of  guiilrie 
dtgcfllinn,  and  in  man,  at  nil  cvcuts.  living  on  a  inixeii  diet  the  work  of  the 
•tomach  appearp  to  be  to  a  large  axtcnt  preparatory  only  lo  the  sul]icqucul 
labors  of  the  intestine.  It  is  true  that  our  information  on  this  matter  is 
iiuperfecl,  being  chiefly  drawn  from  the  study  of  eai«s  of  gastric  or  duodenal 
fistula,  in  which  probably  tho  order  of  things  Is  not  normal,  or  being  in 
large  measure  deductions  from  experiments  on  animals,  whose  economy  in 
this  mpeet  must  be  largely  diRerent  from  our  own ;  but  we  arc  probablv 
lift  in  ooncluding  ihal.  in  Kurselves,  the  chief  eflect  of  gastric  digestion  is 
by  means  uf  the  disiutegraltou  i4|Kjken  uf  nbuve  to  reduce  the  tumps  of  tbod 
to  the  mure  uniform  chyme  and  so  i<>  fscilitalc  the  cbangcs  which  take  place 
to  the  snuill  intMiine.  During  the  dUiiitegraUon  some  of  ths  nroteid  in  the 
meal  is  convened  into  [leptoue;  and  the  peptone  so  formea  is  probably 
abcrorbnl  at  mvc  -.  but  much  |)r<fte)d  remains  unchanged  or  at  least  is  not 
convertol  into  |M-pl<>ne,  and  the  fata  and  starches  undergo  in  themselves 
very  little  change  indi-til. 

In  the  act  of  sirallowing.  no  iiicunitidcrable  •juantity  of  air  is  parried 
down  iulo  the  slomneb,  enianglcil  in  the  laliva,  or  in  the  f<HH].  This  is 
returned   in  eructations.     ^VIlcn   tho  gas  uf  cruclaiiou  or  thai  obtained 


CUANOKS    I.V    TlIK    SUALL    IXTKSTINK. 


891 


k 


t 


tlv  fmiti  the  MoiDkch  r*  oxnmiiifd,  it  it  fouiid  to  coDsi«t  chicflv  nt 

BtlnMKn  iiDil  cnrbonic  arid,  th«  uxyet^  of  the  Btmoaplicric  sir  Imving  iwon 
iumSr  mhm>Tbttl.  In  most  cjms  liie  carbonic  acid  b  drrivrd  hy  »iniplo 
dininoa  tnia  Ibo  blood,  or  ttvm  the  lumin  of  the  itoinscb,  wbk-h  Mmiliirly 
taliv  np  the  oxyj^vii.  In  mnny  oniK-e  of  fliitulrncy,  linwcvpr,  it  mnv  nrUc 
frooi  ft  ftniwnlattvc  dcrompr«riioti  ol'  lh«  sd^ju-  which  hue  been  InVon  na 
■ocb  in  food  or  which  bu  bcrn  prwliiced  fn^ni  the  slnrch,  the  giU:  l)ciiiz 
atb*r  femed  in  lb«  ■tomacb  or  piwein);  upward  Irom  the  inlcflline  ihrougo 
itMpjrlonia. 

Td*  etwnnoufl  quantity  of  ga?  which  is  diacbarged  through  ihe  mouth  in 
CMea  of  hyiMlical  flatulency,  even  on  a  perfectly  empty  eloiunch,  and  wbich 
Mcna  to  eousist  Itrgely  of  carbonic  8ci<l.  preeeiiu  difficulties  in  tbe  way  of 
•xpfauation;  it  is  poasiW  that  it  may  be  »imply  ]iifi'uae<l  from  ibe  blood,  but 
it  »  mbo  poanble  Inat  in  many  cwwm  iI  m  derived  fVuni  air  which  the  patient 
hu  hy«teii«aUy  swallowei),  thv  uxy^cen  liaving  been  remuved,  in  the  atoniaeb, 
by  amorptioa  and  replaced  by  oirhouic  acid. 

In  liif  Small  InUttinr. 

{  Stl.  Th«  ■eini-digc«ted  acid  food,  or  chyme,  as  it  paMn  ov«r  tho  biliary 
ariUce,  caiiBce  a^  ne  have  H«n  (^  '2AA)  (lusbes  of  bile,  and  at  the  same  time 
the  pancreatic  juice  flows  into  ifae  iotealine  freelv.  These  two  alkaline 
fluida,  eapecially  the  man  atronglv  and  ooi»tantly  alValine  pancreatic  juice. 
Cant)  ti>  oeulratiw  the  acidity  of  tlw  chyme,  but  llie  {■oiiieiilit  »t'  the  duoile- 
■DiD  do  not  become  iliminctiy  alkaliuc  iiutil  Mime  diMlnuce  from  the  jiylnrua 
i>  Raeh(«l.  Tbe  rapidity  with  which  the  c.hanK<!  <■■  the  readion  is  com- 
)4rU<d  b  not  the  in  me  m  nil  animnlH.  and  in  tlic  Mime  animal  appeora  to 
vary  avcording  to  (be  naiiiri;  of  tlie  f<>»d.  and  vari<juf  circumnance*.  In 
man.  living  ou  a  mixed  diet,  the  content*  have  probably  bceonw  diatjlictly 
olkalino  before  tbey  have  jiatwod  far  down  th«  duodenum.  On  the  other 
hand  in  doga.  tb«  ronicnte  of  the  small  intcslino  baro  bc«D  observed  V>  be 
arid  thrmigfaout.  and  that,  not  oidy  when  fed  on  starch  and  fnt.  which 
migbl.  bv  an  acid  fermentation  of  which  we  shall  prouotly  ejieak,  giro  rise 
la  an  and  reaction,  but  even  when  fed  on  meat. 

The  coDTentoD  of  starch  into  sugar,  which  as  we  have  seen  is  sooner  or 
Istar  arrceted  in  the  ftomach,  is  reaume^l  with  great  activity  nud  indeed 
completed  by  the  pancreatic  juice,  po»ibly  aMisleJ  by  the  «iiccu6  entencus. 
tbe  nrcaeoee  of  bile  beinf(  asid  to  increaM!  the  activity  of  the  p«iicreaiic 
tBylolyiic  fermoni.  The  conversion  begins  as  won  as  the  acidity  of  the 
diyme  is  sufficiently  reduced  and  ctintiriniw  along  the  intestine:  fH>nio(i». 
bcnreTcr,  of  still  utnligested  starch  may  be  found  in  the  large  iniestiae,  and 
even  at  tiroes  in  tlie  feces. 

Tbe  poncreolic  juice,  aa  we  have  »fcn,  cmuUifles  ftus,  and  aba  splits  them 
(DIA  iMir  nspective  falty  ncids  and  Klyo-rin.  The  fatty  oeids  thus  set  IWe 
faecmne  converted  by  nu-nni'  uf  thi-  alkaline  contenln  of  the  inlestiDt  Into 
■Mpa:  but  t»  what  exli-iit  MpfiniK cation  thiii>  lnk<w  place  in  not  exactly 
known.  Undoubtedly  M>ap  navx  to  a  small  extent  hvMi  found  butli  in 
piirial  bl«(M)  and  in  tlur  thoracic  duct  niter  a  niMl :  but  there  is  no  proof 
that  sny  large  iinanlitT  of  fat  i«  inlrtHlucvd  in  this  form  into  the  circulation. 
On  the  nihvr  band.  if^M  pn-MDcc  uf  oeiitral  fals  in  the  hKtMils,  aitd  to  a 
slight  *ilenl  in  |t<>rtHl  blood,  is  a  cnii*picunuB  mult  of  tbe  digMlton  <d' fatty 
Biatten  :  and  in  all  pn<t>abilily  Hnpimitimli'm  !n   the  intrvtine  is  a  subsidary 

iirocm>,  llie  eifecl  of  which   is  rather  to  facilitate  the  emulsion  of  neutnl 
at*  than   to  introduce  soaps  at-  sucb  into  the  bloml.     For  (he  prmence  of 
sulnbte  toapa  bvore  the  emulsion  of  neutral  fa(».     llen<xi  a  ram-id   fiU,  t.  €., 


892      THE  TiaerKS  and  hkchaxisicI 


roiSTioy. 


■  fill  ooniainine  &  oortain  nmaiint  of  (no  fntly  ndi),  f»rms  nii  emitlsiun  witli 
nn  alkaltiM  fluid  vaon  readily  ilinn  does  »  iinitc  iiL'utrnl  fm.  A  dro{>  of 
ruocid  uil  lot  fall  on  the  tiirrnor  of  nn  nlknline  fluid,  such  a»  a  solutioo  of 
Kidium  cjirhonnto  of  suimble  slrpiigth.  rapidly  forms  a  bruod  Hag  of  emul- 
aion,  and  tliut  cv«n  without  the  Toimt  agitniion.  As  sapooUicstioD  taket 
place  nt  the  juiicttoB  (if  the  oil  and  alkaliac  duid  currents  are  Kt  up,  hr 
which  globules  of  oil  are  deCnched  from  the  maia  drop  and  drireo  out  in  a 
ooutrifugal  direction;  the  iDtengily  of  th«  curreota  and  the  couBequent 
amount  of  emulsion  depend  on  the  fou  cent  rat  ion  of  the  allcalioe  niedium 
and  on  the  solubilily  of  the  «aa})8  which  are  formed.  Now  Uie  bile  ami 
pancreatic  jutoe  ■upply  just  BUcli  conditions  aa  the  abore  fur  einukiomung 
fats;  they  both  to;i{«ther  a0brd  au  alkaline  medium,  the  pancreatic  jutoe 
siviss  rise  to  an  adequate  amount  of  fr«e  fatty  acid,  and  ilit;  bUe  in  ndditioD 
Erin^  into  solution  l)ie  B0tt!>9  as  they  are  formed.  So  tlist  we  cuay  tpeak  of 
the  emulsion  of  fata  in  the  itmall  intestine  as  being  curried  on  by  the  bile 
and  paiicreftticjuioe  acting  in  cDujiiiictiou ;  and  ana  matter  of  fact  ibebile 
and  pancreatic  Juice  <lo  largely  utiiuUltS-  the  coDteuta  of  the  iiniall  intcatine. 
MO  that  the  grayinh  ttirliid  chyme  U  cbajiged  Into  a  creainy-Iooking  fluid, 
which  hti.1  ix^-n  mimntiracH  culliid  chyle.  It  io  advisahlii,  hiiwover,  to  rcMrve 
thix  name  for  lli(^  i-imtcntti  of  thi:  Inctcalx.  Many  of  llie  fnts  present  ia  food, 
for  iiixliini-o,  linltiT,  alrviiily  unnlain  viimi^  fntly  acid*  when  VAten  ;  for  thcMi 
Gilo  the  initial  nctiim  uf  this  pancraatic  juice  is  Iciv  neciM»3iry. 

Thi«  mutual  hrlp  of  bile  imd  pancnmtic  juica  in  priHlucing  an  erauleioa 
explain'  Uinccrluin  extent  the  controversy  which  long  existed  Dottroeii  those 
who  niaintaini-.d  thni  the  bile  and  those  who  maintained  that  the  pancreatic 
juice  was  necewarv  for  the  dig«etio»  and  absorption  of  fntty  food.  That  the 
paDcreatic  juice  docs  produce  in  the  intestine  eiieh  a  change  as  I'arorc  the 
transftreDoe  of  ucuItbI  fatji  from  the  int«etino  into  the  lacteals  is  shown  by 
the  foot  tliat  in  diseaaee  airectiug  the  pancreas  much  fatty  food  frequently 
pawee  through  the  intestine  undigeeted  and  t^n>at  wasting  ensues ;  but  it 
eanooi  be  maintained  that  the  uaucreadc  juice  is  tbe  awe  agent  in  this 
matter,  siuoe  in  animals  in  which  the  pauereatiu  ducta  have  been  aucceasfully 
li>[atured  chyle  ia  ttiil  found  iu  the  lacieals.  On  the  other  hand,  that  the 
bile  ia  uf  utc  iu  tbe  digenliuu  of  bil  h  «huwii  by  tbe  prevalence  of  fatty 
•t«ob  In  ciuca  of  iihstructiou  of  the  biie-dui  U ;  and  though  the  0[M:raiion  of 
ligaUiriog  the  bilc-duclx  and  Ic-ailine  nil  the  bile  extenially  through  a  tuituU 
of  the  gall  bladder  U  opi^n  to  cibjt^'ttun,  «iiK'«  it  in  sopne  way  or  other  so 
txhauata  the  animal  lu  indinvlly  i»  ull<>ci  digu.itii>D,  still  the  rutults  of 
ex|wrimom«  in  which  the  rtwjrpliiin  <if  fill  wan  diHliuclly  leaaenad  (the 
quantity  of  t'ai  in  the  lacteiils  lalling  frum  IVl  to  Q.'l  per  oeut.)  by  tltc 
ligature  and  fistula  obviously  point  to  the  same  conclusion.  That  in  man 
the  euceuK  entericus  poescwes  a  wholly  iiisuthcient  cmulNfying  power  is 
thown  by  the  observation  of  n  case  in  which  the  duodotiuin  opened  on  the 
surface  )>y  a  ftstula  in  such  a  way  that  the  lower  part  of  the  intnttne  could 
be  kept  tree  from  the  contents  uf  the  upper  part  containing  the  hilc  and 
pancreatic  juic«  and  matters  pnjccoding  from  the  atomoeh.  Fats  introduced 
into  ibe  lower  part,  where  they  could  not  be  acted  U]xin  either  by  the  bile  or 
by  the  pancreatic  Juioe,  were  but  slightly  digested.  Without  denying  tbo 
poadble  aawaance  of  the  suocus  enlerious,  or  even  of  gastric  juice,  we  nay 
ooacla<le  that  tbe  digestion  of  fat  is  in  tbe  main  carried  out  by  tbe  conjoint 
action  of  bile  and  |>ancreatic  juice. 

§983.  \Vc  have  seen  (^247)  that  the  addition  of  bile  to  a  digesting 
Riixltire  giv«  riac  tu  a  precipitate.  Thi^  is  partly  a  coarse,  floooulenl  pre- 
dpitate,  GonsiMing  of  |>ara|)eptone  with  some  amouut  of  bile  acidi,  and 
partly  of  a  6n«r,  wore  granular  precipitate,  which  is  longer  in  falling  down. 


OIIANOE«    l.V    TMK   SMAI.I.    INTKSTIN'K. 


898 


I 


nd  ecOBiita  chiefly  of  bite  arids  vilh  h  varinhlc  amount  of  ])eptone;  the 
bavrii  ndinolvied  nn  the  fiinhcr  nddilion  of  ttile.  even  thou<;ti  the  reaction 
<J  \he  mixtan  nimin  tu\A.  En  (he  oppcr  pnrt  of  the  <Ii)i>d«Diini  the  inner 
wrfiKv,  if  esitoined  whil«  digestion  is  i;oing  oii,  U  found  to  ho  lineil  by  a 
(ulond  floGcairat  and  f^niihir  malerial,  whit-b  is  probably  a  precipitate 
ihv  Armed:  (he  rwrpuee  of  this  [irec-ipiutioo  ia  nrobahly  to  delay  the 
pMMig*  of  the  unaij^Mtod  ptrapeptone  along  the  duodenum.    >Ioreov«r, 

rrt  (hMn  thb  precipitatioD.  mle  mtM*  the  action  of  pepsin,  even  while 
muti'Mi  of  the  mixture  tlill  reoiaiiis  aeid;  an<t  as  ttoon  ai  an  alkaline 
retKiioD  a  eMabtbhed  the  peneiu  is  apnarenily  (teAtrored  by  the  trypsin,  »o 
th«l  with  the  flow  of  bile  and  iMuicrcai^c  juice  iuM  the  duodenum  the  pro- 
rave*  which  have  been  Koing  on  in  the  atomach  oome  to  au  end.  In  fact,  it 
wouM  »ero  that  the  juicM  of  Ihe  various  dtstricU  of  the  alimentary  canal 
are  mutually  desimclive ;  tllu^  while  pepsin  in  an  acid  Noiution  deatroys  lite 
active  oonaUluefiU  of  talira  and  uf  imncreaiic  Uiioc  (pri>l>iibly  nl«o  thoM  of 
the  succuB  I'DierivuA),  it  i(  in  ibi  turn  anta^niied  or  d<-4truy*)d  by  tlie  htle 
anil  the  uihvr  alkaline  juice*  of  tin'  iHteMine.  Hi.-nc«,  paniToilic  Jtilce  intro- 
dscad  through  the  mouth  inu»t  low  it-i  powers  in  the  slnmaeh,  mid  can  only 
be  of  naa  aa  an  alkaline  nM-dium  nonlaitiing  (certain  protcid  miittcni.  On 
tha  otbaf  band,  if,  an  vf  haw  n-aitoii  to  lic1i<-vi-,  the  conti.'^nlii  of  the  Klomaeb 
■*  tbey  iMue  from  iImi  pvlnmii  ulill  cmUain  a  Inr^  r|iinntily  of  undigested 
praliUt,  lhe»c  must  be  digtvlcd  by  the  pancreatic  Jtiicc  (nilh  or  without  the 
■^Mbm  of  (he  succus  onterteux).  thi^  nrtimi  of  which  sreiii*  to  he  iMtii^tcd, 
oral  laaM  not  biadorad,  by  bih^.  And  in  dogn  f^d  through  ndiiixleual  fimila, 
tn  that  all  gaitric  digcation  is  cxcludcl.  proteids  nre  completely  digcnteil  and 
gin  riH  (o  iiuite  normal  fecc.  To  whnt  slnin  the  puncrcntic  digcMion  ia 
cmrrkd,  whether  peptone  n  pmcticallv  Ihe  only  product,  or  whether  the 
imBeraatic  juice  in  the  body,  as  out  of  Ihe  l>»dr,  carries  on  its  work  in  the 
nan  dostnictive  form,  wlierehy  the  proteid  malerial  subjected  to  il  is  so 
bmkaa  down  as  to  give  rise  to  appreciable  quautiiia  of  leucin  and  tyrosin, 
H  al  present  not  exactly  known.  Leucin  and  tyrosin  have  been  fonnd  in 
Uw  iatcrtjna]  contenla,aiM]  may  therefore  be  fonned  dunog  noritial  diewcion, 
bal  whether  an  insignificant  '[uantil^  or  a  considerable  ijuantity  of  the  pro- 
leid  material  of  food  U  rhiin  hiirned  into  a  cry^iatliue  funn  cannot  be 
didaitely  Mated.  The  exteiii  to  wliith  the  aclioit  ii  curried  'a  probably 
Aflfenut  in  dilTerenl  aniniuU,  and  probably  varies  also  acconling  ti>  the 
tmtun  of  the  meal  and  the  condition  <if  ihe  bcxly.  Possibly  when  a  large 
mad  tUiDeoeaiary  ifuanlily  of  proieid  malerial  1*  taken  at  n  meal,  together 
with  other  auliataiues,  uo  inronsidcnble  anxxint  of  the  nmu-ids  undergo  thb 

[trofound  dianga.  and,  as  we  shall  sec,  rapidly  Wv«  the  Wly  as  urea  without 
laving  iKwm  iimnI  br  the  tisMCS,  their  ooutribution  to  the  energy  of  the  hiHly 
being  limilcl  lo  lh«  heat  giTen  out  during  the  changes  by  nhicb  they  are 
eonverted  into  un*.  To  this  apparently  waxtf^fut  ui>c  of  protei<U  we  ohall 
ratam  hi  speaking  of  what  i»  called  the  "  luxos  «>ii»umplion  "  of  food, 

{tSS,  lo  dealing  with  the  action  of  pancreatic  juice  we  drew  attention 
{(  849)  to  the  dillorcocr  bc<w<«n  the  rMulte  of  pure  tryptic  digestion  and 
those  obtained  when  bacteria  or  other  microorganisms  were  allowed  to  be 
pnMOt-  We  saw  that  indol.  fur  example,  was  the  product  of  the  action  of 
tbaa  oraaaisma,  not  of  trypsin.  Now  indol  is  formed  in  varying  ijuantity 
dnriDg  ue  digntioo  which  actually  takes  place  in  the  inteettne,  »om«  of  it  at 
tima  appearing  in  the  urine  as  indii^o-yielding  substance  'indiean).  Moro- 
ovar,  baeteria  and  other  microorganiama  are  present  in  the  intestinal  con- 
MMa,  H«Doe,  we  must  regard  tb  cfaangee  taking  place  in  the  intestine  not 
■•  tiw  pore  reaults  of  the  action  of  the  several  digestive  juices,  but  as  thaw 
nsalti  Bodlfled  by  or  mixed  with  the  results  of  the  action  of  miorofirgiaiimis. 


TUK  TISSL'Kfl    ANI>    MKCUANlSMBor    UIOKSTION. 

Wo  rpokc  ftbove  (|  247)  of  bile  as  being  ftQlJae|itic,  but  thu  miut  be  Hiid«r 
stood  na  mciiHiu|{  not  tlinl  the  presence  of  bile  itrreil6  the  action  of  all  mirro- 
oi^DisniH  uitliiii  the  intestine,  but  tliat  it  moditieii  their  action,  keeping  it 
within  ccrlain  liniltd  anil  along  certiiin  lines. 

C^nceniinK  the  exact  iiulun:?  nii<]  extent  of  the  cbang«s  thiu  due  to  tnicro- 
orKanisuis,  uur  kuowlcdgti  In  at  jirc«eiit  rvn-  imperfeeL  The  prot«cb  sad 
the  earbciliy  it  rat's  m«ui  m  be  the  fnod-nutTii  im  wbii-h  tlM««  orKanisme  pro- 
dncc  ihtir  chief  ctrci-t.  Out  of  the  prolridii  tlicy  give  nwe  itut  oiil;  lu  indol, 
but  to  nevi-nil  other  iMninoiiuit«,  iimuiig  which  may  )m  n>entloDed  pbeuol 
(C«H,0),  iif  which  a  ^intill  (jiiantity  may  l>c  recogninol  in  tl»e  feoeH,  Ibe  rest 
being  alisurlH'd  and  npfwanng  in  the  urine  in  the  form  of  certain  pbenol- 
ci>uip(nin<lii,  #iich  ii«  pheiiyl-i'iilphoric  acid.  Out  of  protcidt  tliey  may  also 
form  ihi'  [K-uuliar  iKii»i>noue  bodies  called  f)toma!ne*,  which  appear  in  ibe 
ordinary  putrolaction  of  protelds.  But  their  moM  conflpicuona  eflbctt  are 
those  on  the  carbohydnttes.  As  the  foml  descend*  the  intminf,  the  preatnca 
of  lactic  acid  becomes  more  and  more  obvious ;  indeed,  in  romc  COMS  tlug 
natuniUy  alkaline  reaction  of  the  ini«atinal  content!)  may  in  the  lower  part 
of  the  intestine  be  chanj^od  into  an  acid  one  by  the  prcscncv  of  lactic  acid- 
Now,  lactic  acid  may  be  formed  out  of  sugar  by  means  of  a  tpoeial  orgaaiam 
inducing  what  ta  ft])oken  of  as  the  lactic  acid  feroieiitaliun.  And  we  ham 
every  reason  to  believe  that  in  even  normal  digestion  a  certain  (|uaniiiy  of 
sugar,  ^ther  eaten  an  such  or  ari^in^  from  the  aniylolytjc  convereion  of 
Btaroh,  does  uot  pan  anay  from  iJiv  lul^tine  into  the  blood  as  »ugar,  but 
undergoes  this  fermentation  into  Uetic  acid.  To  what  extent  tbis  changa 
tak«»  place  we  ihi  not  know  ;  the  amount  probably  varies  according  to  tb» 
amount  uf  carbohydrates  oitcn,  the  condiiinn  of  the  alimentary  canal,  aad 
other  circimi.iiance*.  It  may  Iw  under  certnin  circnmstaDoes  Bimply  a  part 
of  normal  digmtion;  under  otlicr  circunutanoe*  It  may  be  exeeesive  and 
give  rinc  to  troubles. 

That  fermentative  changes  may  occur  in  tho  small  intestine  ia  furilier 
indicated  by  the  bets  that  the  gas  there  pteecnt  may  contain  free  hydrugeo. 
anil  that  chvme.  after  removal  from  the  intestine,  continues  at  the  temiiera- 
turn  of  the  body  to  produce  carbonic  acid  and  hydrogen  in  e()ual  volumes. 
This  suggests  the  ])i«etbility  of  the  sugar  of  the  intestinal  contents  under- 
going th«  butyric  acid  fermentation,  during  which,  as  is  well  known,  cwlMtnio 
anhydride  and  hydrogen  are  evulve<i.  By  this  change  the  sugar  is  removnl 
from  the  carbohydrate  group  into  the  fatlv  acid  urmip ;  it  is  thus,  an  tu  speak, 
put  on  iis  way  to  become  lat.  We  Nhnll  m'e  hcreaDer  that  sugar  may  be 
somenhere  iu  the  biHly  converted  into  liil;  thin  euuversion.  however,  takes 
place  chielly  ir  not  wholly  in  the  tiwun',  and  i>uch  change  Bd  mav  take  place 
m  tlie  alimentary  cniial  is  to  be  regarded  nit  suggestire  ratiicr  than  as 
imitortant. 

TIk'  Iiydriigen  Ihim  occurring  iti  the  inti^titie  may  also  arise  &um  the 
protuid  <lecqni positions  spoken  of  above.  However  nrixing  it  may  act  as  a 
reducing  agent— reducing  sulphates,  for  instance — and  thus  giving  riae  to 
sulphides  and  to  sulphuretted  nydrogen  ;  as  a  reducing  agent  it  oauMs  in  (be 
fornialinn  of  tho  fceal  and  urinary  pigments. 

Thuc,  during  tho  transit  of  tho'  food  through  the  small  Inicstiiw,  by  the 
action  of  the  bile  and  i^ncmicic  juice,  and  pi>»ibly  to  some  extent  of  the 
Buocus  eniericua,  assisted  hy  various  microorganisms,  tho  proteid*  are  larg«lr 
diseolved  and  converted  into  peptone  and  other  products,  the  stnrcfa  n 
cbanged  into  nugar,  the  sugar  poosibly  bein^'  in  part  further  converted  into 
lactic  or  other  acidH.  and  the  fats  are  largely  ciuuUified  and  to  some  extent 
saponiRed.  TheM  productfi  as  they  are  fonneil  t)as«  into  either  the  lactenU  ^ 
or  the  porljil  blood veMo In,  so  that  tltc  oonlents  ol  the  aniall  inusltnc,  by  Lbs 


J 


CHANOKS    I\    TIIK    riCrKS. 


S95 


liM  tlwy  murh  lh«  ilM-«M-al  vtilrc.  mn  litrgolf  but  by  no  meaiK  wliully 
4iyriMd  af  ihdr  nuiriliouft  constitkieDtir.  80  far  as  water  is  concerned,  the 
(MMbu  (if  wxicf  into  lh«  small  inieatiiic  niaioiaifti  tuvh  a  relslioii  to  the 
■bwMiMi  fn-ni  it  thnt  the  inlcalinal  oonlentit  ai  the  end  of  the  ileum, 
Ib^p  mach  cbanm<).  "re  about  la  fluid  ax  id  Um  duoileoum. 


I 


I 


/n  ihr  hartje  Inle*tine. 

f  SM.  Tb«  roDt«ni>.  itbcfbrr  alkaline  or  not,  in  ihe  ileum  now  bcooine 
mon  diMinctl}'  acitf.  Thi*,  hi)wivi-r,  is  not  <.-nu»cd  bv  any  acid  accntiOD 
lh«  toucou*  mrrabrnnr  :  tb<-  n-iit-lioii  itf  (hv  ititrelinnl  waits  in  the  Inrgc 
M  in  tiM  unall  intn>linr  i*  iilLidinc.  It  Tiiii>.t.  ihercfurv.  arise  from  acid  fer- 
BWDtftUona  going  on  in  the  omlcnls  ihemwlroi ;  aiii)  thiit  rcrmi'iilaiion«  do 
go  00  is  showD  DT  the  npiM-aninoe  of  mnrah  gas  as  well  aa  hydro^n  in  this 
portiud  i>r  ibe  alimentary  canal.  The  ehamcler  and  amount  of  fermentation 
pKib«bIir  depend  largely  oa  ihe  nature  of  the  food,  and  probably  aim  vary 
ui  ilifli'reni  nniiiinls. 

Of  ihe  particular  chan);c8  which  take  place  in  the  larf^  inteeline  we  have 
no  very  dctiuile  knowledj^  ;  but  it  is  exee«dinKiy  probable  that  in  the  volu- 
MiiRouH  cKcum  of  the  herbivora  a  large  amount  of  digestioD  of  a  peculiar 
kind  )foa  OD.  We  know  that  in  herbivoru  a  considerable  quantity  of  cellu- 
luTC  dieap|>e«ra  in  iiaaiint;  thniuKh  the  alimentary  canal,  ami  even  in  man 
■CNM  i>  ui([eBted.  11  •eeius  probable  that  tlm  i«llLilii«e  dit^'etitiun  takes  jiloce 
in  the  large  ioteHine,  and  ia  the  result  of  ferrueiiiatiw  chaiiKen  carrie<l  out 
l»  neanti  of  mtcruurganiams,  marvfa  gm  beiu^  one  of  Itio  jiruducts  formed  at 
the  same  time. 

Bo  tbb  oa  it  iiuiy,  irhcthi^r  dipaitioi).  pni|>criy  Miealleil,  in  nil  but  complete 
■t  tbe  ileo-cnx-iil  valve,  or  whether  im|><>rtiint  elmnge^  still  await  the  cbynM 
in  the  lar^  >n(o>litie.  one  great  characteristic  of  the  work  done  in  the  ndon 
u  abaorpltOD.  By  the  abstraction  of  all  the  soluble  constituents,  and  (»po- 
«MUIy  by  tbc  irith<lrnHal  of  water,  the  liipiid  chyme  becomes  an  it  approaelMW 
lb«  rMlitin  converted  into  the  lirm  solid  fceoi.  and  the  color  ehil\s  from  tlM 
hripbt  orBDge,  which  the  irray  chyme  gradually  assumea  atUr  admixture 
«)lh  tnJv,  into  a  darker  and  dirtier  brown. 

The  Fe«M. 

t  S8d.  Thew  contfiitt  in  the  first  pltu-e  of  the  indi^stibU'  and  undigcMed 
etinrtiments  of  ibe  n>eal :  shtvds  of  elnxlic  tieaiie.  hairs  and  other  homy  ele- 
mrnls,  mucti  c4-lhiloae  and  cbluniphyll  from  vegrtnbk,  and  some  connective 
twiie  from  animal  food,  fmj^ments  of  dii>inle){rate<l  muscular  6bn>,  fat'Oclls, 
and  lint  nnfrequentty  undigested  starch-corpuscles.  The  amount  of  each 
miiat  of  eouree  vary  very  larf^ly  according  to  the  nature  of  the  foo<l,  and 
the  ditfcslive  powert.  temimrary  or  permanent,  of  (.he  individual.  In  the 
•eotad  ]>lsce.  to  tbese  moat  be  addeil  sutMtancca  not  ditliuclly  reoo^ nitablv  as 
parui  of  ll)e  fimd  but  <lerived  for  Ihe  moi^  ]«n  IVoni  the  aeeivtiODB  of  the 
alironitary  canal.  The  fecea  ratitain  niucuu  in  vuriable  amoant,  oo«ne<im«s 
albumin,  choleaterin,  butyric  and  other  fulty  acids,  lime  and  umKntuia  sonps. 
rolorinK  nwUen,  aixl  inorganic  talis,  Mfiecially  earthy  pltospbatt*,  cryftala  of 
Rnimiatu>-ntagne*in  phinjiliaitv  Itdns  very  consplcuouiL  The  reaction  is  gen- 
erally hut  ool  alwavii  arid.  They  ahio  ountnin  n  ferment  nimilar  in  ila  aettnn 
to  pe|«iB,  and  no  amylolytic  fenm-nl  similar  to  that  of  saliva  or  pnncreatie 
jukv.  The  bile  Mlli  arc  reproMntcd  by  a  •lUall  ijniiantity  of  ehohilir  acid, 
or  aome  product  of  that  body,  and  loHHiUmM  n  very  imall  iiuaiicily  nf  lauriu. 


S96        THK    TISSUES   AND    U  KCH  A  N'liiMS   Of    D10K5T10X. 


Tli«  glycin  and  most  or  all  of  ilie  laurin  have  beep  absorbc!  fmni  llii-  iiitt»- 
tine,  iin<J  llie  cliolalic  ntid  has  li^n  parlly  ab^ifbiKl  aixl  piirtiv  iJi-onii)|kH«il, 
T]i«  fact  that  the  fecea  become  "  clay-colored  "  wlieii  ihe  bite  is  cut  on  frotn 
the  iRtestiiH  alion-a  tliat  the  bile-[>it;Rieut  U  at  least  ibe  mother  of  the  TmaI 
pinneiil :  and  a  ujieeial  piment,  which  Una  beeii  isctlated  and  called  atcrco- 
Diliti,  ifl  aaid  lo  be  identical  wtib  ihu  dulMtance  callet)  uroboliii,  nhich  may 
be  formed  fTtna  hilirubiii.  As  ntlier  apecUl  constituents  i^f  Ihe  feca  niny  be 
mentioned  ercrelin,  a  itoniewbat  complex  nitrogenoun  iMtdy.  whoee  exncl 
cJiemical  nature  h  ut  present  tineertiiiii,  and  n^-nraf  ((^H,N),  a  oitrogeDOU) 
body  which  like  indol  is  derivcil  from  the  denom position  of  proteids  by  tneaos 
of  micniiir^iiigmv,  nnd  whicJi  i*  ihc  cbiuf  ciinite  of  the  fecal  odor,  since  only 
a  small  ijunntity  of  indol  remain*  in  the  I'eciu.  These  odoriferous  bodies  Kte 
derived  d>recrly  from  the  food;  nt  the  same  lim<>  it  is  <iuiie  poenble  that 
other  siwcific  ocloriferuii*  siih^taiiceji  mny  be  secretMi  diKctly  ftom  the  inles- 
tinol  Willi,  wpi-cially  from  ihul  nf  the  large  inlmtine. 


Ths  Lactkalk  aKI)  thb  Lymphatic  Sr«TRH. 

§  28fl.  We  hftvc  »^>on  ih&t  nbsor[>tion  does,  or  nl  least  may  take  ptiuc, 
frvim  the  slomnt^h.  We  have  also  staled  thai  a  large  al)8ormion,  especially 
of  waler.  occurs  along  the  whole  lar<>e  incestine.  Ncvertheleiei.  it  ts  durinf; 
the  transit  of  fowl  along  the  small  intestine  thai  the  largest  and  most  import' 
ant  part  of  the  digested  material  passes  away  from  the  canal,  parlly  into  the 
Iucl«als.  partly  into  the  porial  vessels.  Tlie  portal  veasels  are  simply  paru 
of  the  itcneral  vascular  system ;  the  lacteals,  mto  which  we  may  at  ot'tcp  say 
the  greater  part  of  the  fat  paasea,  are  similarly  parU  of  the  general  lym- 
phatic system,  being  in  fact  the  lymphatic  veasels  of  tlie  alimeniary  canal, 
and  esjiecinlly  of  the  .^mtill  inievttnc.  The  only  reason  for  the  special  name 
of  IttcteHls  is  that,  unlike  the  tymphntic  vcwels  of  other  part*  of  the  body, 
the  lymphatics  of  the  intestine  contain  iit  timc:<  a  fluid  of  a  milky  white 
appe-nnince.  Hence  for  the  Iwlter  imdcntnniling  of  nb»orplion  by  the  lac- 
U-mU  it  will  Ik'  iloirable  lo  study  nl  some  Inngth  tho  whole  subject  of  the 
lymnhatic  syKtom.  . 

Tlii;!  lymphatic  v<weU  mny  bo  said  to  bctfin  in  rainuto  pawiigw.  pomm^^H 
six-rial  clinractcn,  known  as  Igmjth-capiuitrif*.  Ilroadly  spenkine  th^^B 
lymph -capillaries  are  found,  in  lh«  mamnial.  in  all  paru  of  the  body  in 
which  connective  tissue  is  fiitind;  and  they  have  special  conocrlions  with 
those  minute  spactu  in  conneclivo  tissue  which  we  hare  already  more  than 
once  spoken  of  as  lymph-»paces.  Of  all  the  varied  functions  of  conneolire 
tissue  perhaps  the  tuosl  important  If  lliia  relation  to  ihe  lymphatie  ayetea; 
in  nearly  every  part  of  the  boily  eoniieelive  tissue  serves  as  the  bed  or  origin 
of  lymphatic  veasels, 

TlKse  lympb- capillaries,  which,  as  we  shall  see,  are  Oequently  arranned  in 
pleiuses.  are  continuous  witli  other  passages  also  minute  but  of  a  ditterent 
and  more  regular  structure,  the  Ivmphalie  veasels  progier,  which  are  gathered 
into  luri;er  am)  lar;ger  veneU,  all  running  like  the  bloodveisela  is  a  bed  nf 
conneeitve  tiiwue,  until  at  bu>t  nil  the  lymphatic  ve«seLj>  nf  the  body  join 
eitlier  the  great  thominc  duct  which  o|x?m>  hy  n  valvular  orifice  into  the 
Tcnouf  srslvm  at  the  innrtiou  of  the  laft  jugular  and  subcliivian  vciiw,  or 
the  small  right  lymnnntic  trunk  which  aimiTftrlv  opens  into  llic  junction  of 
Ihe  right  jugular  und  »iihc1avian  %Tin«.  The  liitler  course  is  taken  by  the 
Ivmphaiioi  of  thi-  ri^'lit  vide  of  the  head  and  neck,  the  right  ami,  the  right 
Mile  »f  the  duet,  the  right  lung  and  the  right  side  of  tiie  heart,  as  well  ns 


J 


TIIK    LACTEAL8    ANU   TIIB    LYUI'IIATIC    STKTKU.       SIC 


h^  »omn  ««kU  roDiing  froni  pnrt  of  th«  u|>)>er  lurftoe  of  Ui«  IJrer ;  all  tb* 
it«t  of  iIm  Ivrnpliatic*  iiiclintiiii:  tliu  luctenlt  fall  into  the  thoravir  iliiiM. 

Tfaa  lyupluuc  vwwU,  while  likv  tlie  rciiw  ther  join  in  thoircoum  into 
Utkvt  and  uirger  trunk*,  rio  uut  iiicmsc  in  mlibro  *<>  rn{iii]|y  or  w  reguEarlj 
a*  3o  tlio  roiiu ;  tliry  inmy  run  for  twmc  <lii>tiuic«  wiiWit  gmitly  innvMini; 
(a  *m;  and  funln-r  tbey,  unlike  the  vt-ine.  freely  aniutomoec.  fonning  plex- 
OMB*.  Moreover,  during  iWir  roiino  llicy  ciitrr  into  pcciilinr  reliitions  with 
Mr%xctnrM  known  w  lynifihutir  glnM(]]>. 

It  Mill  Iw  ndvunUgeiifiH  lo  consider  M[Mraicly  the  lyiu]>hnlic  vcomI* 
•>cH«r  ihmn  tW'  lyiD|>b-<-Apillim«a,  tbu  lyniph-capillikricti  tliciiie«lvce,  and  the 
iTSxipluUlc  gisnds. 

TA^  Lymphtlie  VesKU. 

%  187.  On  th(M  wo  ii«<hI  nut  ilwell  iii  lenj^h  aiam  their  Minictniv,  in  n\\ 

ilkl  raped*,  rwcniblew  tbut  uf  tbi-  veina.     The  tiiDnicic  duct,  uhicb  in 

hft*  it<  lower  vnd  wbcrv  it  i.*  widimcct  into  wbnt  in  jfaimctimai  ciill(<(t  tbe 

'^■^CMtaTM/un  cAjrfi  n  dtnnifti-r  of  xix  or  »ev-cn  niillim«tmf.  hut  in  niirruwer 

*^9*rr  ii|>,  may  be  wtd  lo  poMtw  thr««  conlA.     Tbe  inner  coat  con»i»t»  of  a 

k^cr  of  fuKir'onu  qiilhflioid  cvll*.  not  unlikv  ihnof  in  ii  vein  bnt  more  •lon- 

kod  with  n  tviidcncy  to  lio  sinumiH  in  oullin<-,  ami  of  a  iil«ud«r  olutJO 

•  nina  aii  whieb  tbeso  mt.    Thv  middlo  conl  ronnisiH  of  fine  bundlee  of 

V^fcaia  iDUfcuUr  libnw,  which  nrt-  fitr  the  motil  pari  (li»]>riecd  L-irculnrly  but 

^^Im  to  a  rertain  oxl«ni   obliiiucly  and   even  lun^tiidinally.     The  spaoea 

neoa  Uie  bundk*  of  muKrnliir  fibres  ar«  occupied  bv  connective  limie 

Datworki  if  elastic  tibre;^     Tbe  oiitrr  coal,  whicli  n  not  well  defined 

Itbrr  fr<>ni  the  niiddk>  co«l  on  the  one  side  or  the  connective  tiaeue  surround- 

thi'  duct  <ru  like  uibtr  side.  ciinsi«ts  chiefly  of  connective  tisue  with  elaatio 

aU,  ft  few  mnacular  fibres  being  somctimea  prtaooL     The  wall  uf  the 

^bofaelo  duct  ia  CMcntially  nmitcular.  and  fiom  tbe  wantiDeas  of  c<>iiiiwtive 

%iwae  aod  of  elutiv  eloncnta  b  more  tender,  nionn  apt  to  be  lorn  than  tli« 

^_   'vall  of  a  \-«io  of  oorreapondlng  ilxe.    >'un>erou(i  valvea  are  present,  thiv« 

^H    Ilk*  th«  viUrn  of  the  Teiai'  bein^  fohtin^  of  tbe  inner  coat. 

^V         Th«  smaller  vtMcl*  rvaenible  in  Mrudure  tbe  thoracic  duet,  the  coat*  being 

^P      of  cnuDH*  mon.- «k-nder.    In  the  majority  of  even  ftinaller  lymphatic  vtwcJa  tbe 

^      BKiKular  fibra  are  abuudnut.    Valves  are  etpecially  numeruu*.  and  in  oianv 

of  ibe  renels.  as  for  in«tance  in  ihcM  of  tbe  nieaeniery,  iuMt  aliove  each 

InlYv,  where  tbe  tube  ia  acuDCwIiat  *w»lleu,  the  intiiu^ular  littm,  which  cUo 
winr*  are  chiefly  diapoead  circnlarly,  run  in  variuUN  dinviii^iuf  m  ns  to  form 
■  eontncdle  network. 
Th«  malleat  Tceaeb,  Rprineing  from  tbe  distinct  lymph -caiul  lanes  to  be 
inBwdialely  deecribed,  oouut  of  hardly  mure  than  an  epithelioid  linine 
iwtfng  on  a  scanty  conDectiTe-liMiie  basis.  Thu  epiih<-li')i<I  cells  are  still 
flirifbriD  and  TCf[ular  in  aluipo.and  tbe  cnltbra  of  each  vesw-l  i*  fairly  uniform 
tlHNl|A>  OWiuK  to  the  valves  whieb  are  exceedingly  numerous,  tlien^  is  a 
giml  leodency  u>  become  beaded.  Tbeso  smaller  vessels  like  the  others  also 
annffoinoae  ftvely. 


k 


LymfJt-tityiUarU*. 


_  f  888.  Tbe  •malhvt  lyntphaik  vcsadH  just  deecribed  might.  fVuni  analooy 
witli  thn  btoodvaaelt,  alniMl  lie  oonBidered  as  capillars-  vetaeh ;  but  tne 
Muno  lynijih-caplllariaak  given  lo  veaaels  which  joining  and  feeding  those 
just  dotcTtlxsl  jHoMW  rttj  different  cbaracten.  They  aiv  ooi  the  whole 
laffcr  in  calibre  ihoo  these,  swi  dbtinclly  larger  tluui  blowl  ca^llariea; 
ihey  are  ezeeediogly  irregtilar  in  sbafw,  and  in  their  junctions  with  each 


898 


TriK    TISSL'KS    AND    M  KCH  A.Vl.SMS    nr    Dlr.KKTlUN. 


oUi«r  fonn  irrogulnr  InUyrintlis  riUlmr  limn  formal  plexiiM* ;  tboj  pomem  no 
vtilvca  Kilt)  thvir  only  ciitil  ia  iin  e|iithc]iiiin  of  n  wry  sinking  cbaracUr. 
].ilie  the  blixid  cnpillnncs  Ihoir  >!lritc1ure  is  rcvmlcv)  Kr  the  tiction  of  rilver 
nilrntr.  When  n  piece  of  lissuo  rontniiiiiig  IrKiph-uipitliiriw.  f".  ff.,  one 
tskcn  from  the  IcmlinoiiF  portion  of  the  diaphrAgm,  if  exsmtncd  itfior  proper 
ireatnieiit  vrilh  silver  nitrale.  luiiiiorous  epscM,  od  the  «h<ilc  tubular  but 
highly  irre^iilur  in  form,  joining;  into  un  irrcgulnr  IsUyriDth,  nn?  »i>en  to  be 
liivei]  with  ii  liiyer  of  epitbelioiil  plates  of  u  peoulinr  kind.  Kauh  plalv  or 
cell,  which  ia  more  or  teas  polyj>onal  or  at  least  not  dirfinetly  fuaiform.  \» 
inarkeil  out  by  lint«  which  are  not  etraiK^l  »n(t  even,  but  very  uiarkedly 
niDucuit,  the  aeveral  bulKiugBof  one  cell  diive-iailiiig  into  th«  depreasioiM  of 
iu  iietghbora  nnd  vice  versa.  Such  epitheliod  plat«t)  of  sinuoui  outliiM.  or 
Hucb  u  iiiniiouii  ejtithelium,  as  we  may  for  brevitjr'ft  suktr  gay,  h  characUriiitic 
uf  the  lyiiiph-capillarice.  A  I yinjih- capillary  ti  \a  fuct  m«r(!ly  u  ajmce  or 
areola  of  cunueclivu  tiifiue,  aoiuetioiut  more  or  Igm  tubular  but  frequently 
irn!|2»liir  in  form,  lined  by  a  ^ugle  layer  i>f  fist,  trauHparvnt,  nticlmtM 
vpillivlioid  plated,  each  of  wbicli  potwcwca  n  remarkably  oiiiuoiia  uullim*. 
Tlitr  lymph -oapillariea  onasturauiHj  freely  with  utlicr  and  upt-n  into  or  join  ibv 
MniilliM  ri'^^^jliir  lymphatic  canals,  which,  many  of  ihrm  »malIor  innn  the 
Ivniph  minllaiiea,  are  dixlinguiitlicd  from  tht^f^c  by  their  mure  regular  dbpo- 
sitiiin.  by  ihcir  vpithelinid  platen  buiitg  fiisifornj  with  very  little  sinuosity  of 
otitlinc,  unci  by  Ino  urotuuce  iif  valves. 

Tbu  lacUial  riultcle  of  a  vilhiH  (§  'Jti2)  ia  such  a  lympli-cnpillary,  more  or 
less  tubular  in  form,  or  |HTlin]w  club-shap«d  and  sometimes  bifurcnte  or 
branched,  jiIdcik)  by  it«clf  in  the  midst  of  the  reticular  timue  of  the  villus; 
ending.  »r  a;*  wv  should  pc'rhn|)»  say  beginning',  blindly  ntuir  the  apex  uf  tbe 
villus  and  joiniiii;  hclow  by  a  valvular  mouth  a  re>;ulDr  lymphatic  caaal 
forming  part  of  Uii-  network  of  rp^ular  lymphativveHcU  with  which  aa  well 
at)  Kith  lympb- capillaries  the  coiuieotire  Ltuiue  of  the  muoius  membnUM  i$ 
Aimiaheil. 

Id  oilier  paria  of  the  body  where  conueotive  tuiue  runn,  lympb-capillarin 
are  more  or  lo«  abundant,  all  i>aiuiiig  their  conleuta.oD  to  ilic  inon  n-giilar 

^mjihatic  cannlit.  In  certain  parte,  aa 
lor  tnslanoc  in  the  c<cntral  ncrvoot  sys- 
tem, the  smaller  bloodvcsHla  are  sur^ 
niundcil  by  large  lymph •capillaiiea,  or 
by  regular  lymjthalic  vemels,  in  tbe 
shape  of  tubular  sheaths.  In  these 
casca  the  lymph-capillary  fonns  a  aorl 
of  ballon  jacket  around  the  artery  or 
vein  vhicli.  covered  with  a  layer  of 
ainuoue  epithelioid  plalee,  liee  in  tlie 
middle  of  a  tubular  B)>aoe  lined  with 
amaller  tdnuouu  plates.  The  plaiuna 
which  exudes  througb  tlie  walla  of  tlio 
liluodvessel  pnwee  accordingly  at  ones 
into  the  tubular  dpacc  or  interior  of  tlie 
lympb-capillary,  wbcncu  it  U  c-arriod 
awav  into  tbe  regular  lymphatic  canaU. 
Such  an  armngcmvnt  iit  opokm  of  na 
a  "  pcrivax'ular  lymphatic.  {Vig.  121.] 
$  289.  The  lympbcapillarim  may  in 
one  «e«aa  be  n^Hed  a»  the  t>edn- 
ningsof  tliv  lym[>luitic  xystcm ;  tbev  arc  the  first  lymphatic  passagra  deli- 
nitely  liiK'il   with  a  continuous  tipitfielium.     But  lympo  exists  outride  the 


triD.m. 


Iiniviwrua  I.TarnAnoL 
A,  annii  «r  <«V««- .    il.  »netj  tmrn  llw 
limlD  .!>.  iciliu«i^Flyoi(i>>«|aociLiuiilLiVi 
i«r«liiw.  «dlL  br  8U1IIUEJ.) 


TETB   I.ACTKALS    AND  THE   LTVFnATir  STSTBX. 


8t>8 


I 

I 

I 


kpillariei.  In  U^atinjc  of  conneotive  (iwue,  $  1'^.  we  ninra  lluio  oot-e  spoke 
of  tbi>  MjHicctt  belweeit  t)i«  inlerladni;  Ixmiliee  of  6l)rillie  as  Iyiu|>li-Hpa(.'e8  ; 
and  indfuil  lliejr  are  dtiriii);  lile  i)ocii))ied  by  fluid  wliich  mnr  be  spoken  ol  as 
lyiii)>li.  It  in  fluid  nliirb  has  in  Hume  wav  »r  •^'tlier  pawed  uilo  them  trom 
Ui«  Mwid  Ntream,  tbroui;!)  tbc  walla  of  tlie  <-a|>illari<»  aud  utber  minute 
bloMlriMclH.  Wit  Hhall  H|>i-ak  of  thin  [laatiafce  an  a  procea*  uf  traaautlalicui 
and  vluiU  muniilor  itn  iialurc  later  on.  Many  of  the  lafx«r  of  theno  iipaoea, 
th«  Mwilie  of  areolar  con  HOI- li  VI'  lr»ue,  are  c»mplet«ly  liiiei)  hv  enitlivlioid 
plttra  irith  Htutioim  <iiuHnn» ;  th^tu)  arc  in  faoL  l}'iui>b-<'npi)lurir>.  But 
many  Kpiicvn,  twpt^'iitlly  lliv  mnaller  onw,  are  nut  ao  lined  ;  thctii!  liv  out- 
aido  the  Irmph  Mipiltarint.  NcrcTthdlw*  tht'V  conlaiu  Irniiih,  which  nincli* 
ing  tbcm  l>r  traii»iidiui»n  tliroiigh  tbi*  walfn  of  l)w^  lilooflvt-iucli,  Mreams 
(rota  tliem  in  unnw;  way  or  oilier  into  ihi-  lyniph-enpillariM  and  no  into  the 
other  lymphatic  vctacls  Colored  lluiil  iiiji-cied  by  ni«ai»  nf  a  line  syringe 
into  tiKH  speoM  soon  findi  iw  way  into  tin-  lymphatic*;  aod  bmdce,  in  the 
vast  mnj'irity  of  caM*,  a  rcrhiin  niiinbor  ■>f  tJieM  anacw  nlwitys  interreiie 
between  ttie  wall  uf  (he<-ApiIlHry  or  other  imall  hlooavesMl  from  whencs  the 
lymph  cornea  and  the  lymphcapiltary  to  which  the  lymph  gov* ;  the  lyiuph 
mual  have  some  iiieuns  or  utbor  of  iiaMiiig  fri^ni  the  spaces  into  the  lyrapb- 
capillary.  It  is  of  course  ixweibie  that  the  lymph  transudes  from  the 
lymph-«pa(W  into  the  lympAcapillary  ibroufih  the  oonliuuous  sheet  of 
epithelioid  plates,  in  the  same  manner  that  it  transudca  from  the  blooil- 
capillary  into  the  lymph  space  throiJ|;h  the  similarly  cuDtinuouH  wall  of  the 
ai^>illary  :  but  there  are  some  reasons  for  ibinkin^  (hat.  at  placea  the  epiihe* 
Itoid  liniug  of  a  lymphatii-  capillary  may  be  imperfect  and  00  allow  the 
interior  of  the  lympb-eapillary  to  i,\ivn  out  tnU>  a  ciinne<-ltve-tiMU«  upace. 

It  will  be  remembered  that,  in  the  caae  of  Home  uf  thcnc  tipnci'^.  n  con- 
uectire-tlMua  corpuscle  may  be  found  lyinKxm  tliefacenf,  or  purtlv  imh-rltlivl 
in,  <iue  of  tite  bundles  irhicb  form  the  wails  of  tboajMice;  au<l  n  < 

the  npaceappean  iis  it  were  iiojwrfet'tly  liiieil  nilh  scattered  fl.i:  < 
may  |K-rha{M  bi-  regardcnl  u-i  imnBiiioiiiu  forras  iHttween  an  oriliniiry  lininchMl 
Conn4i!tive  li.iHiie  corpii»cle  and  a  HinuntiK  ejHtbiilioiil  plat<>.  We  may  per- 
hap*  iV|Enrd  the  epilhrlioiil  pljiti^  as  a  diflihivn tinted  eonn<^ctive-timuv  eorpiiitclc, 
«rho»e  «inno«itii3<  of  giillinc  nrv  the  rpmainn  of  ila  pn-vioiMly  branched  con- 
dition. If  ihiN  be  «n  we  may  cmiuder  tl>e  lymph-i.'«])illary  as  a  difTeranCialiM) 
CODiWotive-tiwiiv  «pacr.  and  c<miMy|uenlly  may  fairly  expect  that  tbo  one,  if 
it  doe«  not  IW  HuggMtcd  actunltv  (>|N-n  into,  should  bo  at  all  events  in  oa«y 
communication  with  thf  otht^r.  \Ve  i<cem  juMilkd  at  least  in  concluding  that 
the  complrtely  lined  lymph -capillari<*  draw  llK'ir  supply  of  lymph  IVum  the 
iDcumplelely  lined  oonncvtiee-timic  spaow. 

We  may  probably  tfu  a  step  "till  further.  Many  of  the  connective-tissue 
oorpuacles  are  iiultediktl  in.  lie  In  PAviti<'i>  exciivaled  out  of,  the  cement  sub- 
atanco  which  unites  the  tibrillie  into  biindlM  and  soinetimeA  joiiid  the  bundles 
togetbec;  iu  »ua>e  situations  the  corpuscles  are  similarly  inihtyldeil  in  a 
hoouweneous  ^'^und  subBtanoe  which  has  not  become  dilfei^ntiated  into 
6brilbe.  The  cavities  in  which  these  corpuscles  lie  are,  like  the  eorpuactoa 
tbemaelves.  branched  and  K«nerally  flattened  ;  they  appear  moreover  U*  be 
geoerally  lar^'er  than  the  corpuscles  so  as  t<i  leave  a  unall  space  whicli  oan 
be  oceujued  by  lluid,  Wliere  two  oorpuaclee  lie  near  e«eh  other  their  Kpacta 
niay,  by  ine«iia  of  the  bnachea.  commiiDicate ;  and  in  aume  situations,  as  in 
the  bixly  of  the  (viruea  when  a  number  of  flattened  corpuaclus  are  imhodilod 
in  the  lamina  of  jfronnil  aubatanoe  which  uuiten  each  Iwo  adjaoenl  {wrallel 
(or  rathfv  cmiicenirii:)  larainte  of  filirilUled  bundli'M,  the  MCricH  of  cavillM. 
uniting  hr  their  brnnchea  may  be  reKUnled  as  constituting  11  lahyrinch  of 
ptUMi^e^  largidy  but  nut  entirely  Blled  by  tlie  corpuscles,  apiuy  bang  lelk  for 


400      TUB 


riSHS  OP    D1GB31 


MOPK  HRiount  of  fluid.  That  fluid  iro  iim-iI  liardlir  My  is  lymph.  And 
tboUEh  tlu:  view  in  not  nac  ndiiiitltH)  cm  nil  Imnda,  tluire  &re  reaaoDA  of  some 
Wflignt  ><»r  thtiikiiig  tliut  tbcw  cavitir*  lieluugintf  Ui  tbu  corpusols  open  out 
into  till!  ci>niii.'rlivi''ti'«iiir  kiukv.''  jiiKt  trviitc^I  of  ur  cveu  mora  di racily  into 
the  lytui>li-i'Hi>iIlnrin>.  When  n  pii,'CP  of  CQiini-ctiv^  lit«u«,  such  Tor  tiuUDoe 
M  tliat  Iving  WlHc'vii  itic  radiuiing  iMindlfo  uf  llu*  titndoii  of  tliL-  dinphrajcra 
on  tbe  pleiirnl  »ido  in  irrAlcd  in  it  luirliciilnr  wny,  the  naiiilt  u.  what  in  cttlled 
B  "  nogRtive  stniitii)g :  "  tbu  matrix  is  xtHiiK-d  brown  hut  llu- connuclut  viu) 
cnvitim  are  left  un»(Aineil,  iind  appvtir  aa  irrrguUrly  liriuivliud  clear  jntdiet 
»liinding  out  in  contrast  with  the  brown  matrix.  In  Huch  ii  pr<;(iHration 
many  of  theec  clear  Bpncc«  arc  »ceu  to  abiit  upon  and  amMmiily  to  low 
tlwmwlvcs  ID  a  neijjhboring  lymph-oapillary,  which  al«o  iilitnyii  «tanda  oat 
in  contrast  to  lh«  mntris,  appearing  as  ti  eloar  »pao»  markml  wilb  tbe  ainuona 
outlines  of  its  plates. 

Wiihoiil  iofisting  too  loiich  on  tbe  argument  dmvn  from  tbis  nvgntivo 
Staining,  and  M«ting  rather  on  tbe  facts  pivvioufly  mentioned  and  oa  goni-ntt 
eonside  rat  tons,  we  may  probably  conclude  tbal  all  tbo  spaces  of  conneclivt* 
tissue,  including  lh«  cavities  of  th«  corpuscl««,  form  a  labyrinth  of  puswgea 
wliich  id  to  be  constd(-red  ba  the  r«al  bei^'nuio);  of  the  lympbalit.'s,  and  that 
this  irregular  labyrinth  is  iu  some  way  or  other  in  fairly  free  mmmunicatioa 
with  the  more  regular  bm  Mill  labyriiilbine  lymph  capillaries,  tint-d  by  a 
definite  epilhelioiil  lining,  and  that  from  thence  the  lym{^i  pasee  on  to  the 
ngular  ajtd  valved  lymphatic  eanaK 

All  over  the  body  wherever  bliMMlvcueb  go.  coiioeotive  tiwue  and  lymph- 
RjHioea  fro  too.  Cvrtaiu  parts  i>f  the  plasma  of  the  blood  pueing  througb  tbe 
trmllso?  the  bloodvuMuls  becoiuci  Ivmph  in  thnte  )yuipb-s|Mces.  As  such  it 
•oaks  tbmugb  not  only  the  hundtva  of  gelntiniferous  fihrillie  of  tbe  con- 
nective liiMue  it«elf,  but  aUo  the  bawmeat  membrane  and  ao  tbe  epithelium 
of  the  miiCDUi'  membrane  and  ito  glauda,  ihir  niulriated  muscular  fibre,  the 
ivrcolcniiiia  and  munclu  vubKlancc  of  the  strinlcil  tiliK,  the  nmrileoiiiia  and 
CODteuta  of  the  n<rrv<^'flb^■  of  n<trvLii,  in  fact  the  clementn  of  all  tbe  ItMuee 
which  an;  :>u|>plicd  with  bloodvcstcU.  ^lorv  than  this,  Ivmph  goes  where 
blotKtvnwIf  do  not  go,  and  in  th««  rituiilionK  iht^  vahxi  an  lympb-iMMagea  of 
tbe  cavitim  of  the  corpuscles  aeems  most  i>irilcing.  In  thi-  i->iriiea  for  initanoe 
bloodvoBeb  and  definitdy  conatituhKl  lyiii|ihatic  vcwcU  ccaao  near  the 
periphery,  and  the  greater  part  of  the  nutrition  of  the  ooraea  (beyond  tliat 
eflwtoti  by  what  w  may  <-nll  mcn^  imbibition,  that  is  hy  the  jauuagc  of  fluid 
between  the  molecules  <.•(  tbe  actual  subst^mce  of  the  tissue)  is  earrk-il  on  by 
the  stream  of  lymph  through  the  corpuecalar  cavities.  In  a  similar  way  in 
bone  lymph  lin<l«  its  nay  from  the  hloodvesaels  of  the  periosteum,  marrow, 
and  Ilavirsian  canals  through  the  very  substunoe  of  the  bone  hy  mmiis  of 
the  labvnnlh  of  lacunw  and  caiialiculi.  And  in  cartilage  we  hare  raueon 
to  think  that  minute  pa&sngos  iu  the  matrix  facilitate  tiM-  transmission  of 
lymph  from  tbe  perichondrium  through  tbe  body  of  iho  cartilage  from  carti- 
lage cell  to  cartilage  cell,  lar  tnore  efficiently  than  if  its  iirogrcw  were  left  to 
mere  imbitition.  The  suniewhat  peculiar  relations  of  t^  lymphatics  in  the 
oenirnl  uer\ous  ayf.tem  we  shall  consider  when  we  oome  to  treat  of  that 
•yMem.  Ueauahile  we  have  said  enough  to  form  a  general  idea  of  the 
anatigeinenla  by  meaaa  of  which  tbe  very  eleawnls  of  all  the  ttasuea  are  bathed 
with  lympli,  and  by  means  of  which  that  lymph  is  carried  back  from  tbe 
eletnenis  of  the  tlHtiea  along  irregular  and  regular  lymphatic  channels  lutclc 
to  the  bloud  fn>in  whence  it  origiiiiilly  cAine. 

£  290.  Thr  trrmu  enritiet.  In  the  mammal  lymi^i-spac«fi  ara  for  the 
moat  part  minute  and  microwonie ;  but  in  some  other  animals  ihey  may 
attain  cunsidf rahlv  litu ;  in  tliv  frog  for  instanoe  iu  which  lymph-capillariea 


THE   LACTKALS   AN'D  THK   T.VHrHATIC  SYSTEM. 


401 


I 
I 

I 


nmf  lyinplindi.'  vkswIr  nr«  scanty,  tlio  Inrgn  8ul)(ruU»«i>u8  ep«OM  which  ar« 
diitcluMs)  wImtd  the  «htn  of  i)i«  back  k  <;ut  through  sn.>  in  mliCy  lymph- 
IpaoM  liiK-d  by  »inuouB  epithelioid  plucs.  Eloth  id  th«  mnuiini))  nod  otlier 
Miimnlit  oorUiti  large  mviliea,  kaowa  ns  serouB  i^avitiee,  ettch  as  the  pcritii- 
iiukl.  ittriviirdial,  pieurAl,  and  olher  oavitice,  nitii^t  be  eonBidered  us  parts  of 
tbo  giMKTal  lymplinlic  Hyaicm.  aud,  indeed,  the  "wroiu  6iiid  "  which  they 
COiitHiit  is  in  reality  lymph.  The  sulwracbnoid  space  nrrotindin}*  the  brain 
wul  spinal  ooni  may  also  perlm|i8  be  recpuxted  as  a  part  of  the  lympliatic 
system,  btit  this  and  the  oonlain^^l  cerebro-spinal  lluid  we  shall  cDnaider  in 
connection  viih  the  central  nervous  wyMttn. 

In  the  abdomen  iif  the  frog,  <m  each  side  of  Ihe  Tei1«bra1  column,  behind 
orabot-e,  I.  r.doraal  ti>  tlie  )ieritoucat  cavity,  I ivs  a  lur&e  lyinph-Hpaeei  »|K)ken 
of  as  the  cuttrnu  niayita  Ijimphatiea.  the  cavity  nf  whiob  in  separated  fmui 
the  peril4Mi«al  oAvily  liy  »  thin  mi'nibranoiM  nhcet  ooomBtinj;  of  a  mi^diun 
basis  of  coniKiitive  tiwui;  i-orcrvd  on  the  [tcritoncal  dd«  by  |>«ritoui-al  t^piilie- 
lium  aiid  on  ihv  elHlcrna  »id(^  by  lymphiUir  epithelium.  TIic  lAtl«r  consLtM, 
as  in  a  lynipbatio  capillary,  of  tint  epithelioid  phtint  with  MJimouR  outUnet ; 
ttie  former  is  made  u|>  also  of  Am  epitlielioid  plates  btit  thew,'  are  niorv  or  IcM 
polvf^mal  in  sbnjM',  and  have  outlines  which  are  nut  ilistincliy  sinuous.  If  ft 
piece  of  this  narlilion,  nl>er  hein^  stained  with  sitvxT  nitntv,  be  sprcttd  out 
and  examined  either  with  the  penionea)  or  with  the  etstcnw  aide  uppermust, 
it  will  he  »r«n  that  in  each  case  here  and  ther«  a  group  of  colli  Ksuming  n 
triangular  form  appear  to  converge  to  or  radiate  from  a  centre  which  eomo 
tinea,  avpeeially  on  the  lymphatic  side,  is  a  mere  point  but  SDmotimcs  is  a 
larger  or  »  smaller  hole,  which,  in  other  nonU,  is  an  oriKcn  or  ttoma.  some- 
linua  elmcd  h<il  sometimes  more  or  lees  open.  On  the  peritoneal  surface  the 
Moaia  is  surrounded  and  Kotrded  by  a  crown  of  what  appear  to  be  small 
granular  cells  placed  at  the  apices  of  the  convergioK  epithelioid  plates,  but. 
which  are  held  by  some  to  be  the  displaced  nuclei  oi  the  epithelioid  plates 
themselves.  ^Vroand  eanb  stmma  which  is  in  reality  a  perforation  leading 
ftwa  the  peritoneal  cavity  intu  the  Q»ierna,  the  oonnective-tiasue  baas 
between  the  two  efHthelioid  layen  ia  art«ng«(i  In  a  concentric  manner ;  tbe 
whole  arrangement  serves  oa  a  commiini<-ation  from  the  peritoneal  cavity 
into  tbe  cisterua,  and  by  these  slomaia  tbe  perit^tneal  fluid  passes  into  the 
oiatenia  aud  so  into  tbe  general  lymphatic  syxlem.  Owin^  to  causes  whicji 
«re  shall  study  pr«Aenlly  tbe  vMlcnu  of  the  Kuutll  Ivmpbatic  ressols  and  sudi 
scooes  as  the  cisterna  are  ccmiinually  li^ln^  draincti  br  tiie  vascular  syslaiu  ; 
tne  ciflema  is  continually  tending  to  empty  il«vlf  anti  »a  to  draw  fluid  IVom 
the  |)erilt>ueal  cavity  thniiigh  the  etomata.  In  the  fnmale  frog  tbe  amall 
granuUr  cells  encircling  ihir  ilomnta  are,  during  the  hrn^ling  rwason  provi<Ied 
with  cilia,  the  action  of  which  incrmscs  tbe  current  from  the  {H'HtoiK'um 
ihnHigh  ihr  donia  into  the  oistema. 

In  ihc  niummnl  Mmilar  stomata  place  the  serous  cavities  in  connection 
witli  the  lymphatics  of  the  walls  of  those  cavitit*.  Tliey  may  be  ntatlily 
teen  in  (he  tendon  of  tbe  diaphrngm.  The  peritoneal  memhrane  of  the 
mammal  ns  of  the  fii>g  oonaiata  of  a  single  layer  oJ'  flat  roithelioid  ]>■»(«• 
lying  on  a  connedire-tiasue  basis ;  the  plates,  smaller  tlmn  those  in  the  ftog, 
are  polyfronal  in  form,  and  their  imllino  is  not  sinuous.  On  the  tendon  « 
lbs  diapliracm  the  epitlielioid  platee  over  the  radiating  sjuiocs,  or  clefts 
between  tbe  radiating  Dondlce  of  the  tendon,  are  smaller  than  over  the  bun- 
dles thenaelTee,  and  along  the  lines  of  these  radiating  interteudinous  spans 
may  be  seen  stomata,  orifices  guarded  by  small  cells,  similar  to  but  smaller 
than  and  letu  conspicuous  than  tho«ie  ju^t  deecnbed  as  seen  in  the  frog. 
These  stomata  open  into  tbe  lymphatics  which  are  abundant  in  the  connec 
live  tissue  lying  between  the  radiating  bundles  of  the  tendon  of  tbedin- 

20 


402      rna  tissues  anti 


[OESTIO] 


■ilirnfini,  mill  through  thum  this  fliii<)  of  the  pflritODMi]  cavitr  |M«W  ftf 
idUi  (hr  lyinj>liiilir«  of  tliu  dinphrii^'iii  nix)  oi  itilo  th«  eoMral  iyiiinhftttc  !  , 
t«in.  The  mor<-iniiiI]>  of  the  ditiphnighm  in  brdittniie.  of  which  we  nltidl 
have  to  tj>«tik  prcwutly,  ^rrnlly  uHiel  the  tlow  through  thi<  eiomata;  itnd 
ewn  |in«MV«  moremento  ot  the  ttinjihriizm  nre  cBectiinl  flir  this  |>iirpo«».  If 
a  (|Uiiiitity  of  injection  inatcrinl.  »ueh  no  »  filution  of  Uerlin  btu«,  be  injected 
into  the  peritoneal  cavity  of  a  livins  animal  it  sotru  euten  into  sod  injccta 
tite  lymphatics  of  the  diaphraf;m,  and  n  similar  injedion  may  be  oblaineil 
ID  a  dead  but  receutly  killed  animal  by  pladuf;  the  aDimal  with  ila  bead 
dflwnwurd.  injeciiDt;  the  coloring  msiter  into  the  abdomen,  or  even  pouriog 
it  into  i)ie  hotlow  uf  the  diaphratcm,  end  then  imidu^ii));  movemeois  of  tli« 
diiphrajcm  by  a  rhythini<'ally  re|>eated  artiBoial  respirntinti.  Not  only  ool- 
OTM  flaidi  but  eolored  material  raerdy  ni*peaded  in  tluid  and  ounh  ihinga  . 
the  globtitea  of  fat  in  milk,  or  eveti  reil  hl<HMl'c:(in>u)K'loi  may  tbtis  lind  liieir ' 
war  from  the  p«rll(»i«al  eavity  into  the  lynipbatiw  of  the  duipbT«|[m. 
IdoccjcI,  if  u  \i\wt-  of  the  dtaphn>i;m  i<f  a  rM'enllv  killts)  nniiniil  ))e  $trecoTied 
out  Hi|<t  milk  p.iiiml  npi>n  it,  the  fill  glohiikit  »l  milk  iiiiiy  b<-  >wa  with  the 
aifl  of  a  leiut  or  inicnwcofw  to  dMipjiear  thmiigli  tUe  i<tt>iaata  in  a  tiumWr  of 
uinutv  vorltccit- 

By  MDiilnr  <t<>mata  iIk-  pleural  cuvity  w  pnt  into  ciiminunication  with  ll 
Ivmnhnlivs  not  only  nf  the  diaphrnfoi  (on  ibi  pleural  enrrncc)  but  nim  < 
(W  Iting*.  and  to  n  smaller  extent  of  the  tJioradc  ntills,  and  during  the  m»vo- 
nienl«  of  the  chcet  in  breathing  the  ponleiita  of  the  pleural  cavity  art)  ooo- 
tinunlly  Imni;  pumped  away,  partly  into  the  lymphatics  of  the  lungs  partlyf 
into  those  of  the  diaphragm  and  elicst  walls.  In  a  similar  miinoor  perinir*' 
dial  fluid  passes  away  from  the  pericardial  cavity,  and  the  fluid  in  other 
■mailer  serous  cavities  such  b*  that  surrounding  the  leatia,  pMsws  away  from 
the  reajjeelive  cavities  into  the  general  lymphatics.  The  quantity  of  fluid 
in  even  the  lar}^t  of  ilieee  cavities  i§  at  any  one  time  in  normal  eonditk 
very  Hnall,  but  that  Suid  appears  to  be  constantly  renewed,  old  lltiid  pa 
away  to  (he  lymphatic  system,  and  new  fluid  taking  ita  place.  I'he  ser 
nivili(«.  ili^refure,  are  to  be  re>,'ar^ed  aa  expanded  initial  rmervain  tfov 
which  ttn  well  no  frtiro  the  lynii>h-rnpillari(»  and  lymph  »pa<!es  of  the  timic 
the  lymph  stream  in  omtinually  being  led. 


TUf  Slrudiirf  of  lofntphalic  Olantt*. 

S  S91.  Solitary  fotlidv*  a  alt  I'r<irr'gpolfiie».  All  along  the  small  inteettoe 
and  at  various  points  of  the  circuinferenoe  are  found,  jtartly  in  the  suhmu- 
(VMi*  tintue  hut  reaching  up  to  the  surface  of  tlie  mucous  owmbrane.  small 
rouniieil  bodies,  of  (he  nixe  of  a  small  piu's  liead.  more  luiiueriKia  ]>erl)ai)s  in 
th'-  lower  than  in  the  upper  [utrt  of  the  bowel,  uflen  called  "  solitary  glanda."_ 

!Pig.  122.]  They  are  not  glands,  however,  in  the  sense  (^  209)  »f  being' 
iivolutionN  of  the  niuenua  membrane,  and  it  is  better  perhagw  f  >  speak 
them  as  tolitnrif  j'otlif/a.  At  the  free  border  of  tJie  small  iniMtiite,  oppoaiM 
to  tlie  atUtcbmentii  of  the  rmwentery,  tltc  mucous  membrane  contains  loi 
OTkl  patcliMi,  Peyer's  patches,  phicwl  lengthways,  there  being  sonte  twcotJT'  i 
thirty  of  tlicac;  ihcy  arc  nhMt  iiiirucrous  in  th<!  ileiin)  and  dii>npi>ear  toward'' 
the  nuodenuni.  Kach  patch  i«  pructically  a  group  of  tulitnry  folliclvit.  and, 
indMd,  tli«M  jiatches  an-  sometimes  spoken  of  ns  a'jminaled  fi/tlielf*.  In  the 
lanra  int«liDf>  <9p<%ially  at  the  cncum,  and  in  man  particularly  in  the  ver- 
miform aptieiidix,  solitary  fblliclM  are  abnndant,  but  here  iher  lie  tiholty  in 
tli«  submucous  titnuc  below  the  rauscniaris  muoosn.  In  the  Kfininch  iiUi,  in 
young  pent>le,  there  occur  in  (he  muooos  membrane,  geiieriilty  betwe«u  xho 


TRB   LACTEALS    A»I>  THE    tYMPHATlC    «T8TBM. 

tivAHtlM  of  tliQ  ^Inuils.  strui^turee  vhich  itre  very  similnr  to  solitnrr  folliclw 
am)  wliich  are  8i>ni«tiiue«  <tt\{eA  "  lenticular  gUiuIe." 


rt 


,  .*!-J- 


^^*^^' 


iiai-nnN  av  t»«  Uxirs  niEiiiiaii  *  SuuTiHr  Pi>ti.ii'i.ii  cm  l.vspiioit<  Nium  I.K.    K'tiiUT.i 

«,ini>lilltorilMnoiliilDwltb  tlic  Irmpliaiil  l!HUiit*nlT  blltoxrkf  rrom  UwiHilari ;  t%  epitbelliim 

til  Un  luMaitue;  t.  tIUI  :  Uk>1[  •pl(h*liuiM  In  (itrllT  lin>l[«n  away ;  -I.  envl*  <■'  I-lolsilKllio.l 

A  wiliury  follicle  cudnwIm  nMCiilinllr  of  n  upherica]  mam  of  fioc  mlvnoid 
lifiii-  till-  m<wh<¥  f'f  wliich  are  crdwilci  wilh  luiiciii^ytc  In  tin-  interline  ns 
we  linve  wrn  'J  "J6ll;  llK^cnoHOciivctiMiir  lying  between  the «pillidtiim  above 
Mxl  the  muwulnriK  miicoxir  beloir  1iiu>  n  rcticuliir  arrangement  and  contaiaa 
l«uoocvte«;  but  in  lh«  follicle  the  network  i«  1in«r,  clocer,  and  mora  reij^'i'*'' 
than  eWwhera.  the  me«he«  are  atinnst  completely  fillexi  with  teucootcf,  and 
the  i>nhmcal  mas  breaking  thro«igh  the  miiHculam  mucosie  reaches  eomo 
w«T  uonn  into  the  i^ubntiicouB  tiwuu^  Over  the  surface  of  the  follicle,  which 
bufgee  somewhat  into  the  iiilerior  of  llie  intcetine,  villi  may  he  preKTit,  hut 
the  ^'laiidn  of  Lieburkiihn  ara  pushed  aside  and  are  found  only  at  its  circum- 
ference. Into  this  mass  of  adenoid  tiaeue  one  or  mora  sinall  arierim  enter 
Hitd  break  up  into  a  capillary  network  the  blood  from  which  is  cnrried  away 
hy  one  or  more  small  veins.  Around  the  mass  there  is  placed  a  more  or  leea 
well  developed  spherical  lymph-spMee.  lined  with  sinuous  epithelioid  plates 
and  ciinlinudtia  with  tlte  neighDonoK  lyinpbatic  vessels.  This  lyniph-ajnoe 
or  /yKipA-n'wujr  as  it  is  called  thus  toraif-  a  hollow  jacket  filled  with  lymph 
rouiiil  th«  spherieal  aiass  of  adenoMl  tissue,  but  is  not  cnmpleie,  be iii);  broken 
by  tite  entering  and  issuiiiK  bloodvcaaels,  or  by  imperfect  |iuriitton«  psH-iuj; 
Iroai  the  tissue  without  to  the  ade»i>i<l  tiwue  within.  Thi?  blo'xIvewniU  mil 
bridk*  In  uuuttioii  are  covered  by  a  layer  of  ejathelioiil  plnteri  cotitinuous 
with  thai  lining  tl»e  outer  wall  of  the  Jat-ket,  ns  also  with  the  one  which  nmre 
or  luM  <!oiuplelely  iiiveMU  the  itiuer  maax  of  adenoid  tiwue. 
The  k^ticocytw  whicJi  occupy  the  iue«hee  are  of  dilfbreiil  Hixeti.  Kumi^  are 
I  large  or  al'moM  lu.  \aT^  ait  while  blood -oorpiiac lea,  from  ntiich  indeed  they 
'  'elly  ditr<cr  in  the  faet  tliiit  their  nuclei  nxhilnl  a  nuclear  network  which  a* 
have  aeoii  (S  'i'^)  i*  ap|inr<-ncly  not  prAtciit  in  the  while  eorpuitclf^  of  the 
blood.  Tho  majority,  however,  are  much  smalW  than  white  hlonal-corpuMihv, 
iheir  emallni'w  being  cbieily  due  to  tlw  imnll  amount  of  coll-MubntaiiMi  sur- 


4M        TUIC   TISSUKS    AND    MKCUAXISMS   OP    DIOESTIOX.  1 

miiM)iBp[  the  nacleus;  io  Bome  only  a  inctv  flim  of  oclI-ifibslRnm  I'M)  bt 
(l«iecle<l  so  thai  the  nucleue  appcare  aliiin§t  as  a  so-called  "  tree  "  niiclrut. 
Many  of  the  leucucytea  nmr  he  seen  to  be  uuderKoin);  karyoinitueU.  iiMli> 
cniiiif;  llial  they  are  luultiplyiiig  bv  divisiou  ;  and,  indeed,  there  are  inmiy 
rcANOUH  for  thinkint;  that  in  the  aiteimid  imue  of  tliese  foUielea  and  other 
iiimllar  ntruL-turef  a  very  conttiderabic  iuiilli|tliuati<in  of  leucooyt«s  lakee  place. 
Many  of  the  leucocyleA  of  Ihette  rolliclt^  exhibit  under  favurnble  eircutn- 
HtanctM  amieboid  niovement*,  and  the  nnaller  leucocytes,  indeed,  even  the 
rinalUwt,  iieHiii  at  tliuea  m  active  a*  the  larger  i>ij<«. 

A  tulitary  follicle  then  may  Iw  contidercd  a*  coiiaiHtiiig  in  tlie  first  |>lac« 
of  a  riiunclcd  capillary  network  fed  ami  dniiiii-d  by  xmall  arterie«  and  veina, 
all  ^uppiirtcd  by  a  minimal  anigiint  of  ordinary  connective  tintue.  lit  the 
wonil  jiln<%  tbe  intentticM  of  thi»  vascular  ni-lwork  arc  filkil  up  uilb  ade- 
noid tiMue  the  fine  mo>hc«  of  which  arc  crow<lc<!  wilJi  IcucocylcH  id' variable 
but  on  the  wh»]c  «niitll  sixe.  I.iistly  the  nuimicd  itinM  thux  ■■»n«iiiuu>(l  » 
aurrouniUxl  l>y  a  lymph-sintjf.  the  fluid  of  which  on  the  oav  hand  balli«i  the 
mass  and  on  the  othir  hand  ii  frco  to  pan  anny  into  the  lu-ighboriag 
lynnhslic  canals.  Ait  the  blood  streams  through  ther  capillary  network  part 
of  the  plasma  poning  through  the  capillary  walls  becomes  lymph  in  the 
Dieshes  of  the  adenoid  tissue.  HcDce,  after  probably  acting  on  and  being 
acted  ou  bv  the  leucocytes,  it  paasea  into  the  Ivniph-Kinus  and  to  away  into 
ibe  K«DeTal  lymphatic  stream.  lu  all  probability  the  lymph-siDUs  is  chiefly 
fillecl  fVom  tlie  fluid  thux  coming  from  the  ndeooiil  tissue,  bo  that  a  inaiu 
current  tlows  from  the  lymph-einuit  int>i  neighburing  lymphaticfl  in  all  diree- 
tjona;  but  it  niav  be  that  the  lym)ih:iiuus  ii>  partly  supplied  by  the 
lymnbatics  around,  ho  tlmt  wimc  nf  the  lymph  from  adjoining  slructurev, 
while  tlowinj;  in  the  .liniis  around  the  adejioid  iiMtie,  li  aubjected  to  the  action 
of  that  tiiwue.  In  all  prolmhility  loo  the  Irantiil  of  niatiriul  from  the  hluoil 
to  the  adenoid  tiuue  iv  accompanied  by  a  reverse  currant  from  the  adenoid 
tissue  to  the  blood,  so  that  the  blood  in  poesing  through  the  follicles  not 
oi>ly  gives  but  also  lakes. 

Since  multiplic-ation  of  leucoeytea  anpeant  to  be  continually  going  on  in 
the  adenoid  tissue,  and  since  the  folliclea  do  not  increaoe  indefinitely  in  size, 
some  of  the  lencocytes  must  disappear.  There  is  every  reason  to  think  that 
ifaey  jHiss  away  into  the  lymph-sinus,  and  so  joining  the  general  lyiuph 
Stream  become  the  corpuscles  of  the  lymph  of  whicn  we  siiall  presently 
speak.  If  tbo  central  adenoid  luass  is,  as  some  think,  inveated  with  a  con- 
tiuuous  eoat  of  sinuous  epithelioid  plates,  the  leuoooyles  which  leare  the 
follicle  must  pass  ihrou|<h  the  eout  in  the  same  manner  that  the  white  cor- 
piieclea  of  the  blood  lui^-rate  through  the  walls  of  the  bloodvesttels ;  but  it 
IS  more  probable  that,  an  oiheni  think,  the  eoating  is  discontinuous,  Uie 
s|)acesef  the  adenoid  lUaue  "jieuing  freely  at  inter^'au  into  the  lyniph-HQUK, 
and  thus  atfordinn  an  eoiiy  path  not  only  for  the  leucocyto,  but  alao  for  the 
lluid. 

The  lenticular  ){liinds  of  the  stomach  a]>pcar  to  h>'  only  Ins  condeii»xl, 
let*  completely  arrangd)  mantes  of  adenoid  twsue  .  and, »«  wc  shall  sec  hero- 
after,  uuall  miuM-H  of  adenoid  timiue  more  or  lew  cimdmsi'd,  more  or  Iraa 
trauaiiirnied  into  definite  follicin,  arc  met  with  in  various  parts  of  the  body. 

^202,  .'I  i'ev'i-'n  juilek  u,  as  the  pbnue  "ogminntHl  ^'Imid"  indicates, 
merely  an  aggregation  of  solitary  follicles.  A  well-formed  Puyor'a  patch 
con>tsl«  of  a  variable  nundier.  in  man  fifty  or  even  a  hundred  or  fewer,  of 
Military  follicUw  arranged  in  a  single  layer  close  nnder  tlie  epithelium,  but 
Mtrvichiug  down  into  the  submucous  tiiHue,  the  distinction  of  which  from  the 
tuucDUs  mombnino  proper  is  to  a  great  extent  li»t  br  tbo  breaking  up  of  the 
muMularis  mucoacB.    Between  the  censiltucnt  follicles  glands  of  Licberkulin 


THK    L*CTKALS    ANU    TQE    LYMPUATIC    SVSTKM. 


405 


^ 


'  fanid  CBClroliug  ihe  (blliclM  aod  villi  ptvjoct  frgm  the  tuirfacc,  whih) 
WtwMo  Mid  bolow  tbo  Klandt  l>lMM)vt«»el8  nnu  Ivniphnltcn  ntv  nbunittint. 
Ov«r  cNcli  rollicif  iKitli  gTniuk  wiil  villi  an?  absent,  ko  tKnl  thn  iipjwr  mirfucc 
of  th*  fullirJo  If  ill  ootitiKt  nitli  ilii;.  (rfiithvlium  of  the  iDlo^linu.  wtiicli  is  livm 
•borMr  ■!»]  B»ai«  cubiotl  ihm  olMwfasre. 

Esoh  follicle  OOiMUtfl  of  n  Komevrhst  spherical  vnscuLir  maee  of  udcnoid 
UaDt,  forrouDdnl  nii>rv  or  leu  completely  by  n  lymph -einuB;  in  fnct,  the 
tCratfara  of  tn/cb  of  thr»o  aggivf^lcd  foilicln  r«ficat;«  so  completely  that  'if 
m  Hiltimrr  follicle  ihnt  tbc  same  dcscnptioo  and  diacossioa  will  »rTc  for  both. 

i  893.  KympJtatie  gland*.  If  the  strocturv  of  a  follicle  just  described  bp 
born*  in  mind,  ibkt  of  a  lymphatic  gland  is  niiiile  more  c»sy ;  for.  tu  a 
Pr7(T'»  fmtch  is  a  mere  acRregBtioD  of  otherwi^  uDchanged  follicles,  so  a 
lympliatir  (.'land  is  a  ooUwtion  of  aimilar  folliciee  d  i  lie  rent  ia  led  into  a  com- 
fmet  aod  stMncwhat  complex  or^^. 

A  tTpkal  lymphatic  gland  has,  though  the  form  varieti  a  i^ood  deal,  tbo 
ihapt  of  a  kvdney  [Fig-  l'J31,  in  so  far  at  all  eveoU  that  n  more  or  lufl 
flMvcx  aide  can  bi?  di&linguijWi  from  a  canca^'e  Hi<le  in  which  is  placed  the 
hilna  when  Uie  btoodTesaels  enter  luid  mav ;  from  the  hilua  olao  isue  I  jui- 
fhrtJB  veaiek  ithioh,  nnce  they  carry  lymph  amijr  fram  tba  gland,  are 
calkd  efbnDt  lymphatieB.  The  afferent  v««neU  carryioi;  lyuipli  to  Ihe  gland 
paai  into  the  ([laod  in  a  Mattered  fushiou  on  the  convex  »ide. 

Itia.  vm. 


PuwBjJWtif  Sbctki.t  or  LtxnitTK  (luiii-. 

l.t.1.  rm*M  tiraptaMBt:  C.  Donlod  mbiUMOT:  JT.  raUcatulag  cmdioTMida)- 
t:  I. •.Irini^^noi:  «,  DbromcuM  nadlBc  uaibotalB, Ir.. Into  ttia  tutalaMVcf  tk* 

Th«  ^land  it  inTcwti-d  by  a  capsule  of  cODnectire  liaue.  containing  in  tbe 
■MB  of  uiuny  unimnl>  a  very  consiilerable  number  of  plain  muscular  Cbrei. 
Two  layui  Biay  M  timn  be  distinguished  in  the  capsule— an  outer  layer  of 
coMfBcr  tad  an  inner  layer  of  liner  couneetive  conneclive  lii^ut;,  it  rich  {>lexuB 
of  Imphatic  veeaels  bciof;  placed  betnecfi  the  tiro.  Froni  the  oapMile  a 
nu&iber  of  partilJoua  or  tratiMiI'r,  BtartiuK  from  various  puinta  of  lb«  turlkee 


406     TB^TfBSTOnwrnfWWffrW^fnffBfWTW^^^^ 

anil  oooN^ciug,  like  tli«  capsule,  of  vliisuly  iui«rw(iveii  biiiiilii'j  of  conoeciive 

lifMiv  itiixiil  ui>  n'ilh  »  variiibli!  numlwr  of  plain  miiw-ulmr  likrei.  pwn  Inlo 

the  g)an<l  in  niUrvcliinn  convitr^'iug  lownnl  (Ik  liiluti.    In  tlicotilcrorcirfum- 

Ibrciiliiil  jiart  uf   tliv  i^lnml  ihttc   lrnb«culBo  sn^  Inrgi--,   run   in  a  Mraigiii 

dirvclton,  arv  Imt  lilllv  limiidi<'il,  iitid  iin-  r»^  iirrimgi.-<l   ihat  they  cat  u|i  thi' 

jDiitiT  port  iif  thi?  gland  infi  ii  i)iiinlM;r  of  c^hnmhuni,  having  more  or  lcs«  th*- 

pbrm  of  Iruni-atvil  pyruinitlii,  ci>iiv«rgineIo  or  nidiatiiiK  from  the  ionrr  purtion 

*tif  the  glniid  iioitr  tlii;  liiliir.     TboH*  cnamlMtiv  have  bc«D  cull«d  i/iw/i.  ariI 

CODfilitUie  togeltivr  the  mrlrj:  nf  ihc  glniid,  iho  iniMrr  porlion  being  called  ibe 

mf'UiUa.    On  rciic4iing  tbe  medulla  l\iv  tralKvuliD,  lliAoouneof  wbieh,  a> 

Kc  have  just  «aid,  is  in  thp  cortex,  on  the  whoio  straight  and  uohraDchul. 

rapidly  divide,  brcmiing  thinner  and  more  slender,  and.  running  and  joining 

together  in  all  dirvctions,  form  an   irregular  o|)en   network,  giving  nse  to  a 

lulivrinth  of  pasNiges  into  whicli  the  alveoli  of  tbe  corlex  o()eu. 

Tbe  Irahecutfe.  in  fact.  Blartiug  from  tbe  capeule  divide  the  gland  iuUi  a 
Dumber  of  spacett  which  in  the  cortex  are  arranged  in  a  re^ulnr  manoer  anil 
have  the  form  of  cunvergiiig  chambers  or  alveoli,  comniunicutltig  laterally 
ttilb  each  other  lo  a  small  extent,  but  which  in  the  medulla  rajndlr  diminiBli 
in  ai^e,  and,  opening  freely  into  each  oilier  on  all  eidea,  form  a  labvrinth. 
At  the  bilus  tbe  medulla  cornea  to  tbe  aurtac-e  of  (be  gland,  but  ^Itewliorv  i* 
separateii  from  the  surface  by  the  cortex.  The  number  of  and  regularity  of 
diviniiin  amimg  the  alveoli,  and  the  sharpneKa  of  ditiiinction  bctwwu  tbe 
cortex  and  tite  medulla,  difier  in  the  glandn  of  dilfi^reui.  animal*. 

Each  alveulns  of  the  cortex  eoDHiiilti  in  its  itintrtil  |uirt,  oontitituting  alxxil 
two-lhirda  <>t  more  of  tbe  whole  chambtir.  of  ■  moiui  of  adenoid  Iw'ue 
crowdcil  with  leucocytes ;  tbiM  nuuu,  which  fiillow*  the  form  of  the  ehnmber, 
is  wbotly  like,  in  fact  re|ieatit  altuiut  exactly  the  structure  of  the  raaas  of 
kdmoid  tiwiio  of  a  solitary  fullick  of  tlic  iiitMline;  it  ia  vpoken  of  as  the 
fittictil'ir  or  ifiamlular  tuliMiinre,  or  moTV  bricflly  the/otfiW^,  of  the  alve<>Iu». 
Tbia  follicle  is  sepftrated  on  all  sides  from  tbe  cni>sule  and  trabecule  which 
form  tbe  walls  of  the  alveolus  (or  from  the  tnioecuUe  atone,  where,  oa  in 
some  cases,  tbo  alveolns  is  a  small  one  lying  between  the  larger  AuperAoiitl 
alre<ilj  and  the  true  medulla)  by  a  space  which  is  occupied  aa  a  rule  not  by 
true  adenoid  tissue,  but  by  a  coarser,  more  open  reticular  tissue,  the  meahcs 
of  which  are  larjfer  and  less  regular,  and  the  bant  of  which  are  mori^  mem- 
bmnouH.  liaving  more  the  characters  of  being  branches  of  nudeateil  hraucki-d- 
cclls  than,  as  we  have  seen,  ia  the  case  with  true  adenoid  tissue.  Th<-  mi^h<« 
of  thb  reticulum,  HIcc  those  of  adenoid  iissue,  are  oocui>ied  by  Ifucm-ytrs : 
bill  iImsc  arc  not  .10  numeroua.  and  moreover  more  rciulily  escape  from  this 
nitustion  than  from  the  fullicleii.  ao  that  when  a  section  of  a  fn^sh  gland  is 
bruHbtfd  with  a  cnmclVhair  pencil  or  nhakeii  up  in  normal  Hidini-  i°olutioa. 
the  spacn»  of  which  we  are  speaking  arc  to  a  large  extent  cleared  of  the 
loueocytes  previounly  present,  while  the  follictilar  siibalancr  .'<till  remains 
crowded  with  ibcm.  After  treatment  with  tWvcT  nitrate  it  ia  aoeii  that  tite 
eur&ce  of  the  tral>cculie  (and  eitpiiile)  liorilering  this  spooa  in  ouch  alveolus 
b  lined  with  sinuous  epithelioid  pliitcs,  and  a  coating  of  similar  plates  may 
sometimes  be  mode  out  on  the  surface  of  the  follicular  substance.  In  other 
word^  this  space  between  tho  tmbeculai  and  the  follicular  substance  ie  a 
lyiaph-spaoe  corresponding  to  the  lymph-sinus  of  tbe  solitary  follicle  of  lite 
IntcMioe,  and,  indee<l.  is  spoken  of  as  the  li/mjiA-tiHut  or  lytjiA  eAannrl ;  iIh 
lymph'sinus  of  an  alveolus  of  a  lymj>batic  gland  diHbrs  from  the  lymjtli- 
liniti  of  a  solitary  follicle  of  the  intestine  in  its  space  being  much  hrokcu  up 
%y  reticular  lusue. 

TIte  imuulsr  passages  of  ibe  medulla  are  similarly  occupied  by  a  centtml 
niaiu  of  follicular  subatonoe  eurroundeil  by  a  lymph-siuus ;  but,  wherena,  in 


TBK    LACTRAL8    AMU    TUE    LVMPllATIC   SVSTKM. 


407 


thr  nh-nili  the  miOH*  of  follicular  e»lMUui«r  Mke  nn  ibc  torm  of  mor*  or 
\nm  |>vmniiiliil  l>li)clc»,  iu  ibti  iitiiliilLt  tliu  tiilliciiliir  sul)*Mnoo  it  srranmd  in 
ibr  fonu  of  brakiH-liiiij;  und  nii)Li|ii&ioziiig  i-iir<l>,  l/i--  nuvltiiftiri)  tortii,  tar- 
roundvd  br  «  lubulsr  lintii«liiii^  and  ■nnxtumo^iiiu  jiu-krt  or  Ij'niiili  noas. 
At  Um  luactioB  of  iba  c»rii'x  ami  mixlulla  the  folliclea  nt'  ihc  alvtwli  of  the 
fcroMT  DrmDvh  off  Into  un<l  Iimi>iiiv  ilia  niMlullarv  corIs  vf  the  Utter,  and  tbe 
Ijniiph-iintw  of  th*  former  mv  Biniilflrl}*  conlinuoug  irilh  the  Ulitrrinlh  of 
lyawi-riniBW  of  the  Uuier. 

Tm  gUnd,  in  fiict.  may  b«  coDiidfircd  as  copsiMing  uf  three  i^mrls— lh« 
•fcalitlDn  lupplicd  hv  tli«  («pHil«  and  tmbecuia;  and  divi'linc  tlio  interior  of 
Um  (claod  into  the  r^ulur  alveoli  of  the  cy>rtcx  and  the  Ttibyrinth  of  lh« 
OMdnlla;  the  follicular  eulutance  occupj'ing  the  centre  both  of  0.w  alveoU 
•mI  "t  ihi!  lubj'rinili  and  cootinuou?  througboul  both,  as  if  it  had  oriK'inally 
dlbd  u]f  the  wliuk  of  the  spaces  of  the  skeletoo  and  lind  BubsetjueDlly 
■hnink  awmy  oa  all  sides:  ana.  lastly,  the  lympb  cliaiinel  uccupjin^'  all  ihie 
s|MMa  left  Mt«eeu  the  fullicular  aub^iance  and  tlie  skeleton,  ouu  ibus  form- 
iiqc  «  labvriutb  uf  '\\s  own  ihniugbout  ih«  gland.  Obvimtsl/  a  lympbatio 
cIumI  is  a  contulidaied  and  dilTereiit idled  collection  of  lyniiitiatic  follicles  or 
Pij«r*s  patr.b.  In  u  I'ercr's  uatch  each  follicle  i*  distinct  aod  iudcpendeut; 
in  a  tymitbaiii.-  tfland  llie  fi>[)icl«  arc  fuaed  together,  [wrtinlly  so  in  ihe 
oorttx,  but  (viniplHt'lvKi  in  th<-  rawhilla. 

Tbe  attV-mnt  lym|iliatic  vi-mmU,  nbich  are  mdihII-  or  niediuin-«iz«<l  veiHcls 

with  thv  utructiiri' dnuTilfd  in  ^ 'J^7,  nflfr  forming  a  plexim   between  the 

two  Ittrwi  of  lb«  cu[i»nlc,  ojirn  out  into  lh<-  lyinph-iiuiiMv  <if  the  alvti)!! 

btOMln  tb«  corttui  :  tluw  lyniph-oinuiiea  ar<^  pracliiMilIy  tyniph-cnpiUario 

inia  wbicb  Ilia  regular  aflrrcnt  lynijihiuir  vnneU  brcjik  up.    The  eflercnt 

Itmpliatie  vMsak  are   ■imiUrty  connected  with   the  lympli-rinustx  of  the 

InlUnt  the  hiliM^;  here  \i\v  lyinphoipillariM  of  the  miidullu  opitn  into 

form  the  re|>ular  lyiuplialic  ve£«ela  uliicb  inue  from  the  gland  at  this 

I  piMnt.     In  the  airerenl  veaseb  the  lymph  is  flowing;,  u*  we  altall  see,  at  a 

jcrftain  rote  and  under  a  certain  preamire:  it  cotitiuuctf  to  dow  througb  the 

pjabyrinih  of  the  lyinnb-Mnttwaof  llie  gland,  bnthing  as  it  (lows  the  fullicular 

LaobMaiic«,  its  couiae  being  retarded  by  the  reticulum  of  the  lymph-siuusea ; 

jii  flnalty  iMiia*  by  the  dfcredit  veMeln. 

Tlie  aniall  arteHo*  entering  th«  glaiid  at  the  hiliu  run  along  the  skeleton 
of  traheculw,  dividing  im  ihey  go  \  ut  intervalu  they  iieod  oH*  small  bnuichea 
wbieb,  leaving  the  trabecular  hi pnort,  traverae  the  lyini>h-:iiniu.  and  plun^ng 
tnAo  tb«  Ibllicular  subaiaiice  brcjiic  up  into  the  cnpillanis.  By  fur  tli«  greator 
part  of  ibe  hliHxl  *ciit  to  tbu  gland  thua  nins  iii  I'upillary  nclworku  in  (he 
follicular  MibstJUice  of  the  alvi^di  and  medulla.  From  ihi^-  capillaries  the 
,Uood  finds  its  way  back  by  veins  tlirough  the  lyinph-«inus  to  the  trabcculK. 
kmnd  sn  baues  from  the  gUixl  at  the  hilu». 

I     (SM.  Obviously  U-re.  ■«  in  the  lymphatic  follicle  of  the  intcsiiue,  the 

^•deikoid  iMnia,  nr  follicular  salistaiiee,  is  Ihe  seat  of  nn  intcriK'tioii  between 

Uw  btood  and  the  lymph :  here  the  I>!o<nI  gives  Kin>olliing  to  and  takes  same- 

iMag  tttm  the  lymph,  or  at  lenel  i*  in  some  way  chungetl ;  here  the  lymph 

■  (akA  frnm  and  gives  up  to  tlie  blood.     We  may  be  oonlident  that  itieae 
^changes  tak«  place,  ihou^h  our  knowledge  as  lo  the  exact  nature  of  l^KBt 

iMOffniial  present  very  limited. 
Om  event  Uking  place  in  the  glaitd  wems  tolerably  certain.     The  leuoo- 

■  cyXn  which  occupy  the  meslics  uf  tlie  l^^llieular  suMtonce.  and  the  vbar- 
acten  of  which  are  similar  to  tliose  i>f  the  leuoocyies  of  a  follicle  of  (he 
tnleiline,  multiply  in  the  follicular  substance.  Cell  division  appears  lo  be 
particularly  active  in,  but  not  excluMvely  confined  lo,  ceitaia  areas  iu  tlw 
follicks  vpttken  of  as  lymfJi-ttioi*.    In  nuclear-stained  seetMiis,  that  is  in 


408        TUK    TISSUES    AND    MKCtIANI»U8   OP    DI0B9T1ON. 

PlWDuntiDiie  so  treaUHl  thai  while  the  nuclei  are  stained  deeply  Um  oetl 
Domes  ftre  very  lightly  ataiiied  or  not  at  all,  there  may  bu  frevjueatlv  •eeu  iu 
■  follicle  nil  area  (or  more  than  one  area)  cuiiaialiiig  of  a  very  liKtit  oentn 
surrouuded  by  a  doepiv  stained  ring.  In  ihe  Hjthl  ceutre  the  cell  bodiea of 
the  leucocytes  are.  relatively  lo  the  nuclei,  larjjcer  lliau  the  turruuiiding 
eone;  aud  since  the  cell  bodies  are  not  stauied  the  cvotml  tiortion  u|i]>cars 
lighter.  It  ia  in  the  clearer  ceiitnil  area  that  uuclui  uudergoin^  iiiitnwix,  and 
indicatiug  cell  divison,  are  efijieoiall;^  ahuudanL  The  surplus  odl  iMpula- 
tion  thus  arising  appears  to  poM,  chiefly  at  all  erenU,  into  tlic  lympfa-sinus, 
nai  to  leave  tlie  gtaiid  by  the  effereut  lymphatic  rcasda ;  on  vxaniinnlion  it 
Ir  fouud  that  IyiDi>li  whicli  has  paiacd  ihruiigh  a  iiuuiber  of  eliuxU  »  riclier 
iu  IvRiph  corjiuMrlea  than  the  lymph  which  in  coinias  to  tbo  g1and«^ 

Many  lymphatic  glanda  contain  a  (luantily  of  ulack  pi^ent  whidi  li 
chiefly  iIuiKwiti^l  in  Ihe  hraiiclK^d  celi»  of  tlie  rccliculum  of  the  lympb- 
vinusiM.  Tiiii"  is  iinihably,  in  many  ca«>  at  all  evunte.  pign)L>nt  bronght 
to  tliu  ^lanit  in  ui«  lymph  vciW^ls,  and  arrolcd  in  ito  cotirK^  tbrnu^'h  [he 
IjDipli-nniis;  and  in  the  bronchial  lymphatic  glands  the  pigment  dimply 
ooti»isl*  of  minute  particle*  of  enrbon  introcluc«<l  into  the  brODcbtal  pas- 
sage by  the  inspired  air,  an^l  carried  from  the  bronchial  paasaMS  to  the 
?;lande.  In  some  cnstv,  however,  pigment  i>>  also  found  in  the  bo£ee  of  the 
oncocytes  of  the  follicitlur  substance,  and  ihis  pigment  has  probably  a  dif- 
ferent origin ;  iU  history  and  purpose  are  not.  however,  as  yet  known. 

Tbk  Naturk  avd  Moyeugmv  of  Lyupb  (IscLUDUca  CaYLR). 

$205.  From  what  has  been  said  in  the  preceding  section  we  are  led  lo 
regard  the  mnltitudinouH  itpacee,  boili  »mall  and  great,  of  connective  tuuiic 
all  over  ihi;  buily,  including  among  theiw  thti  "■unmii  cavitiM,"  »*  forming 
tlic  hegiiining  or  iiiuta  of  the  lymplialic  system.  Into  tfacH  Bpacm  cenail 
partfi  of  the  plnixna  of  the  bloni  transude  and  mi  lieconic  Ivmph  (whetbtr 
the  cpith<dioi<t  lining  of  the  Inrgt!  aemus  cavities  pbirs  anv  distinct  part  in 
regulating  the  traiwidation  of  serous  fluid,  i.e.,  of  lympfi  into  those  cavi- 
ties uc  do  not  know);  from  these  spaces  the  Ivniph  is  continually  flowing 
through  the  lymph  caMllariea  into  the  lymphatic  vessels,  am)  so  by  the 
thoracic  duct  nnd  right  lymphatic  trunk  hnck  into  the  blood  system. 

Tlie  amount  of  lymph  occupying  the  lymph -spacce,  tympb-capillariee, 
and  minute  lymphatic  vessels  of  niiy  region  varies  from  time  to  time  accord- 
ing lo  circumstances.  A  hand  for  instance  which  has  been  kept  hanging 
down  for  some  time  becomes  swollen  and  the  skin  t«nse:  if  it  be  raised  the 
swelling  leesens  and  the  skin  becomes  loose;  and  a  similar  temporary  awell- 
ing  of  the  skin  of  the  limbs,  and  of  the  skin  generally,  ia  fre<|ueiitly  tbe 
reMill  of  active  exercise.  Suob  a  swelling  is  partly  due  to  the  bloodvuteli 
being  diluted,  or  ti>  the  return  flow  along  the  veins  being  retarded  so  that 
the  blood  ca|iillari«»  become  distended  Hith  blood,  but  is  much  more  laKcly 
owing  to  tbe  lymph-^pacea  and  lymplialic  vessels  of  tlie  akin  ai»l  under* 
Iviiig  stnicturea  buing  unusually  Ulled  with  lymph.  On  the  other  hand  the 
SKin  may  buoomc  shrivelled  aud  dry  fr<im  a  defideuey  of  lymph  in  the 
tymph-spanv  and  vceseU.  Under  even  normal  circunutanees  tbe  quantity 
of  lymph  in  tlie  tissun  may  vary  considerably,  atiil  under  abnormal  eir- 
cumslnnces  a  very  Urge  amount  of  lymph  may  greatly  distend  the  tpacca 
of  tbo  connective  tinue  of  the  skin  and  otluT  atrnctnree.  giving  rue  tO 
(Kiema  or  drojK^y.  Obviously  there  are  ageiicira  at  work  in  the  bodv  by 
which  the  aiijienranco  of  lymph  in  tlic  spaccf  or  ile  removal  thence  along 
tlH'  lymph -cnauncls,  or  buUi,  may  be  cither  increased  or  diminished. 


i  286.  Ji£  it  alowly  llows  from  ite  ongJD  in  th«  tlaauee  tu  the  rnoiiUi  nf 
the  tlioracio  duct  (ire  idb^  for  Bimplioitj's  sake  omit  the  right  lyiiiphalic 
truuk)  the  lyoipli  bmbjecud  to  the  influenoe  of  the  lirni[>)mtk-  gUixU.  and 
IB  iMasiblT  aflbot«d  hf  th«  wallit  of  the  lyinph-vcaoels.  Moreover  the  lymph 
oonlng  mta  one  tiaue  difl^ts  mora  or  lew  id  certain  ohitmoten  fr^^in  the 
Ivnifih  atiiing  in  another  tJMiKt,  ju»'l  un  ilie  v«nou*  hloo<l  of  one  organ  diflera 
fmiii  the  venoiia  blood  of  amithor  nr^nii ;  and  theie  dtflttrcneca  tnav  be  ex- 
iiiigi-rac^ij  by  the  aciivilv  nf  tfati  i>iic  or  othor  tinue.  Of  thwo  diAerenoea 
by  fnr  the  niOMt  atrikinff  id  that  lM*twM'n  the  Ijrmph  comine  from  the  ulimen- 
tary  cmnal  during  activv  digRMion  and  known  n*  fftifl^,  ana  tlie  lymph  n>m- 
inii  from  other  pnrt«  of  the  bixly.  When  digtiation  i»  not  going  on,  mid 
wlivii  o(>n«i»|iienlly  no  ounxidenible  absorption  of  niiilerial  fnxn  ihci  iilinicn- 
tiir^'  canal  into  the  lacteuU  u  taking  ]>lacu,  tlie  Duid  Howing  along  thr  Itu.'- 
t«n1s  M  lymph,  not  differing  from  the  lymph  of  other  regions  to  any  marktMl 
degree. 

The  fluid  aeoordlnglv  which  flows  along  the  thoracic  duct  in  an  animal 
which  has  not  been  fed  for  some  considemblo  time  may  be  taken  m  itlui- 
ttaciug  the  g«neral  charactera  of  Irmph,  The  couteule  of  the  thoracic  <luct 
mar  be  obtained  by  laying  bare  the  junction  of  the  ituhclaviun  and  jugular 
(in  the  do);  the  iunclian  oi  the  axillary  and  jtigulnr)  veins,  and  inlrodiicing 
a  eanula  into  the  duct  as  it  entera  into  the  venous  system  at  thai  point. 
The  operation  is  not  unatlended  with  dithcutties. 

Lymph,  so  obtained,  is  a  clear  tmiisparent  or  slightly  opalescent  fluid, 
which  led  to  itself  soon  elols.  The  dulling  is  not  so  pronounced  as  that  of 
blood,  hut  clotting  a  caused  as  in  bluud  by  the  apjiearance  of  fibrin.  The 
libriu  which  in  formed  though  scaiitv,  O-S  |>er  cent.,  is  identical  apiutrently 
witli  that  of  blood.  an<l  an  likr  u^  we  know,  all  that  ban  been  sud  previously, 
^$  14-JH.  eouoerning  the  natuns  of  clotting  blood  ap)>lie8  equally  well  to 
lymph. 

Examined  with  tlte  miero«ci>pc  lymph  contains  a  number  of  corpiisolea, 
lymph-oorpuHcle*,  whiL-h  in  all  their  cliaracien'  tu  far  as  m  at  )>nweni  known 
are  identicid  u-ilh  nhite  hlood-curpuiicinf :  lh<:y  vary  in  nixe  from  0^  to  15  f, 
and  the  umaller  eorniifclcs  are  much  more  abundant  in  lymph  than  in 
hlixxl.  LJkc  the  whilv  blood -oorjiuacles  of  blocul  they  cxhibil  amci'boid 
ninvontcnts.  Their  number  varies  in  different  animaU,  nod.  apparently,  in 
tita  same  animal,  according  to  cirnimstnnces;  on  the  wbok-  {icrhaptt  it  may 
bft  said  that  lymph -rorpuacl«fl  ar«  iibniit  ai>  nuniarous  in  lymph  an  whiih  o>r- 
ihiscIm  in  blood.  Even  when  enrv  care  ie  taken  (o  avoid  odmixuire  wiih 
blood,  lymph,  and  cspeciallv  ehylc,  ii»t  unfrwiiiontly  contains  a  citrtain 
number  of  red  blood-corpuwtee :  eomvtimes  tboee  are  stifflcicnt  to  give  thv 
lymph  (or  chylej  a  reddish  tinge.  Th«y  have  be«D  observed  within  the 
hTiDg  lymphatic  vessels,  even  within  email  onvs.  and  have  prohnblv  in 
aom«  manner  or  other  tnftde  their  way  from  the  btocl  into  the  lymph  elian- 
nels. 

j}2d7.  The  cheuiotl  coni|iodtioD  of  lymph,  even  when  taken  in  encfa  cose 
from  (he  thoracic  dttet.  varies  a  good  deal,  llie  total  aotids  are  much  less 
than  in  bkwd.  amounting  in  general  to  not  more  than  5  orUjwr  cent.  Hence 
the  venous  blood  of  a  vascular  area  contains  rather  more  solids  than  the 
arterial  blood  of  the  uime  an*,  unc«  tlie  blood  in  giving  rise  (o  tJie  lymph 
during  iu  paasage  thn>ugh  tbi;  ua|iiltarin  from  the  arteriat  to  the  veins  has 
pan4,>J  with  relatively  more  waiter  than  solid  matter. 

Tlie  ])r(itei<U  amount  on  the  average  to  about  3  or  4  jwr  oeni.,  tltat  is  to 
Miy,  to  about  half  ait  much  ai>  in  blood,  tlw  jMiniQular  {iroteids  pieaent  being 


TRK   TISaUSfl   Axn   XKCRAKISMS   OF   niOKSTtON. 


tlie  Mue  as  in  Mood,  Tts.,  albumin.  iiArsf;l<i))u]in  am)  anle>cedeiibi  of  fibrin. 
In  IvBipb.  aa  dietingub)ie<)  Crom  clirle,  the  iiuantity  of  fat  U  small,  uni] 
coDeiflla  of  tbe  uhuhI  neutral  lata  anil  the  M>a|«  of  their  fatty  acMla, 
toseUier  witli  lecithin;  cbulmtcrin  may  alaa  lie  pteaent.  A  osrlaiii  aimniut 
MSujiar  (ilexiniM-)  apjimra  tu  be  aJvraya  pnaeiit,  am)  wevftral  ulKwrvi'-i* 
hav«  fouutl  an  a|){ii«ciHl>U  (jiiaiitity  of  unm.  The  asli  of  lynipb  like  ihut 
of  bJoDtl  aeruRi  mtitaiiw  ■  (v>ii«ii)i'nil>l«  i]UaiilitY  of  sodium  cliluridc,  wlitla 
idtoapliaieit  and  putttxh  htw  Kcaiity :  it  alit>>  i:un[«iim  iruo,  aiiimiTntly  in  too 
onat  a  i|uanlily  li>  l>c  niviniiiltvl  fi»r  br  ihc  fuw  n-<)  corpuwlnt  which  may 
oe  pnwnt.  From  lymph  a  oertiiii)  nm»iiMt  of  gu  ciui  be  t-xtractvd,  con> 
aiating  chiefly  or  slmaM  vxcluaivnly  of  c»rl><>iiii:  uciil,  with  a  tmall  nunntity 
of  niirogcn.  ih«  amount  of  oxygirn  prwi-ni  Ix-ing  i-xiiTilingty  •mail.  The 
iiniH'tiniR-o  of  this  we  nhall  new  when  wc  oome  to  rtiiily  rt^ipi ration. 

Broadly  speaking  no  mar  hit  thai  all  thv  sulwtaiiirc*  jircwot  in  blood- 
plafnia  ara  pnwnl  at»o  in  lymph,  but  are  uc«om{>niiied  by  a  largor  (|UaDtity 
of  water. 

£  398.  Lymph  may  also  be  obtained  from  wpaTuto  regions  of  the  body, 
ax  from  the  tower  or  upper  limlw,  for  instance,  by  introducing  n  fine  canula 
into  n  lymphatic  v^iwe!.  In  iu  ;^ueral  leattirci  the  lymph  bo  obtained  re- 
semblm  ihal  taken  from  the  thoracic  duct.  AiialyMV  of  the  lymph  distend- 
ing the  suhculaueous  ctmoeciive  tisane  in  cams  of  dropsy  iliow  that  this 
contains  much  }«m  KtHd  matter  ihaii  uuromi  lymph  taken  from  Die  thoracic 
duct  or  lar^r  lymphatic  voaela.  From  this  it  has  been  inferred  that  the 
lymph  normally  existing  in  the  lymph-spacea,  lymph-capillariea  atn)  minute 
veaseU  contain*  an  exnia*  of  water;  and,  mdeed,  it  haa  been  a»ert<->l  ihut 
the  percaitu)^  of  tolids  inoreaaea  in  paaain);  from  tbe  itnialler  to  iho  litr{^'<ir 
reaseU;  but  this  cannot  lie  reganlml  aa  diHtinctly  proved.  The  numliei'  nf 
«orpu»cle«,  however,  tu  wc  have  iiln:iiidy  wii),  appears  to  Im^   inenMuuHl  in 

[laning  through  the  lymphatic  glundv  It  haa  alao  been  i>tjite<I  tliui  tlie 
ympli  in  the  6ner  ly'mph-vvevcli'  ctnt^  even  leas  lirmly  than  that  in  tlw 
ihtiracic  duel.  From  this  we  may  infer  that  wmie  of  the  leacocytnt  in  the 
adeuon)  tia!>ue  of  tbe  follicles  of  n  lymphatic  glanil  find  tbnr  way  in^>  the 
Ivoiph-sinus.  and  so  into  the  efferuit  lympliatiot,  awl  ibai  •ome  of  the  fibrin 
ractors  are  added  to  the  lymph,  or  at  Icowt  that  aome  changes  farorablo  to 
clotting  are  brought  about. 

it  89fi.  We  showed  in  ^  -90  that  the  large  serous  cavities  of  the  perito- 
Deutu,  pericardium,  ete.,  were  to  be  oonadercd  as  parts  of  the  lymphalio 
aysteni,  and  that  the  "  serous  ttuid  "  in  these  cavities  was  continually  joining 
tlie  lymph  stream ;  indeed,  pericardial  or  oilter  serous  Huid  has  all  tlie  gen- 
ernl  characters  of  lymph.  We  have  aJieady  laid,  $  -'0,  that  these  fluids, 
nbeii  taken  fiwh  from  tbe  body,  dot  (tbia  is,  at  leaat,  the  oase  in  uoit 
animab);  the  clot,  when  examined  micmsoopically,  is  found  to  consist  ol 
oolorlc*!  curpu)>cl«9  tike;  thoae  of  lymph  or  of  blood  onlaiiuleil  In  the  mealies 
of  librin.  Both  in  tlutir  proteid  and  otiier  ohemicul  cmuiiiut-nts  thme  serous 
tUiid.i  nwtiiilik-  lymph.  Anajysee  of  the  aceitinulalions  of  lliiid  iiecasionally 
ucrurring  in  thtw  i^nvitin  Hhow  that  they  contaiji  aometimet  Iuhm  and  ttom»' 
tim'«  mure  r>ulid  matlitr  than  ordinary  lymph.  The  aiiiieoux  humor  of  tJie 
eye  <'»ni:iina  very  little  solid  matter ;  nn<l  the  oeTvliriiKpiiinl  lluid  ii'  »o  pecQ- 
liar  that  il  bud  l>ettcr  bo  conxidered  by  itM-lf  in  coiioirclion  with  the  nervous 
syxtem. 

|i  300.  €tii/t«.  In  fitsliog  nuimaljt  tho  duid  flowing  along  the  lai;teals,  as 
mny  Im;  M<cn  by  in«|>cclion  of  the  mcvenUiry,  is  clear  and  transjinrent :  it  is 
Ivmph,  diflcrin};,  ni*  uc  have  tnttt,  in  no  Mssntial  r4>j)cet«  from  the  lympb 
ttoning  along  otlur  lym|iliattc  vvasols.  Shortly  aflsr  a  meal  ouniaining  fat 
(and  every  menl  docs  contain  some  liu),  the  lympb  becoints  white  and 


THK    KATURK    AND    MOVBURKTS   OT    l.YMI'll. 


411 


5r 


Kke  milk,  Ibe  morv  w)  tlie  rklier  the  nieni  U  hi  ftit ;  it  lit  iImo  culled 

Owjnv  lu  tlK>  relmivpl)-  largo  ciunnuty  »f  thiH  itiilkv  tliiiil  which  f'>r 

'tins  iilWr  w  nmil  cu<itiiiit(»  t'>  Ix^  |ir>uriHl  inr^  lh<<  ifiumcir  duct.  th« 

WmcnH  of  thu  duct  kIh  Iwcunu!  milkj:,  uti<l  nn  alw)  cittird  dijlc     In  the 

'^mdcdnct  Vat  chjrkuf  ihdACUaU  u  more  or  Jen  oilxoil  with  Irtiiph  rroin 

^^Htr  IrnpbsltG  v«web.  but  tb*  former  I*  <k>  propondanititif;  thnt  the  I'nii- 

'^ittM  ibt  dud  BMy  be  tnkon  iu>  illiioimtiii^  th<?  natiirp  of  chyle. 

1  CKtU  di&n  from  lymph  In  one  in)i»irtBni  rc»iicct,  nnd  one  only ;  whi-TM* 
*ynpn  utdinnrilr  containR  a  ■mnll  qiiginlity  only  "f  Int.  ehyli!  coiiliiiii«  u  vi^^ 
*^m  unount.  The  tidual  Hinount  of  ftil  preiwnl  in  ihu  ctiyle  ol'  the  Ihorncic 
*4tj(t  rxries.  tic  may  l>c  ex{)ected,  very  coiinderiibly.  Rccordinif  ti)  the  nittur« 
^f  ibv  iiieal,  the  stap?  of  dif^tion.  nnd  vnri»iia  circ'umBlnDo».  Fiv<-  por 
Cw>t.  b  ■  very  common  amount :  in  the  doi>  it  haa  been  found  to  vary  from 

2  lo  15  per  cent.  The  iiiereaae  in  fat  is  chiefir  if  nol  exclusively  due  to  no 
iacrnue  in  th«  neutral  iiua:  ihoujfh  nbetber  tbo  small  •luanlUy  of  soape  ami 
of  tecithin  preaeni  is  greater  tbau  in  lymph  lias  not  been  distinctly  ascer- 
tained. ChoiMterin  ia  probablr  present  in  creat«r  amount  than  iu  lymph, 
■oce  it  probably  comes  fVom  the  bile  tMured  into  tbe  iniettine  duriof;  diitee- 
tiiN) ;  but  tbi*  u  not  ccnaiu.  How  far  llie  nature  of  the  fnt,  that  ia,  tbe 
|M«fNNtii'n  of  the  veriouK  kiiidii  nf  fut,  of  jttcuriii,  etc,  variw  witJi  the  fltis 
pnNBt  in  tbt'  nrntl  hnn  mit  lieon  ilclinitcly  aacerlnincd. 

Tbe  cunditiim  i>f  thu-  fnt  in  clirle  ia  peeuliar.     rinmv  of  it  vsiiiDi,  like  tlie 
fikt  in  milk,  in  ilic  form  of  liit  gtabulea  of  various  sinv.  but  all  i>nmll.     A 


xrty  riin«idi-nibl>-  ((UBniity,  how^rcr.  i»  present  in  the  form  of  exoocdiagly 

licr  tlmn  any  glob 
Biilk  ;  ilu-tp  exhibit  active  "  ftrowninn  movement*."     The  fat  prcucnt  in  thin 


niiituti'  ■(ilirriilm  or  grnnuUv.  far  «niiiUcr  tlmn  any  elobiil<«  lo  be  Mon  In 


li>rm  it  Bpokei)  ot  at  the  "  molecular  basis"  of  chyle,  nnd  i)>  very  dislinclivc 
of  chyl«.  In  the  emulsified  cnnlents  of  the  intestine,  ollcn  eitlled  chyle,  the 
ftt  b  finely  ilivtiled,  ami  lo  a  larxe  extent  into  ^rnall  kI"Ii>iI<^^  but  there  is 
anthiug  oorreAiHiudiux  to  thin  molecular  basis;  tbo  fut  du^  not  assume  ihia 
oonHitinn  until  it  bus  pUMed  out  of  the  inlaitiu«  into  tJie  Incleula.  Lymph 
•saminni  with  the  microacope  shows  bcBliK^  tbe  white  corpuscles  only  very 
few  oit-^lubtik«,  and  notlung  of  tbis  molecular  basts.  Just  as  in  IHct  lynitiii 
Is.  bnMdIy  T<pcnkinjt,  blood  niiaiu  its  ml  corpusdea,  SO  obyle  is  lymph  plu* 
a  very  larp^  qunnlity  of  miniitely  divined  i>fulral  Alt. 

The  liHal  amount  of  lymph  or  of  chyle  which  enter*  tlie  bli)o<l  system 
ihtouefa  the  thiirucic  <luct,  tlwugb  it  probably  varies  oonsidembly,  in  prob- 
■Uy  alp>  alway>  vcrv  lar^  It  Ma  bwn  culciilntcd  that  in  n  wcllicil  uiimnl 
M  quaniitv  djual  nl  loa«l  to  that  of  the  nholc  blood  may  pRM  ihrwugb  tbe 
tltoracic  <luct  in  Iwcnly-four  hours,  nnd  of  thi>  it  is  supposod  that  about  lislf 
eoBSM  ihroagh  tbe  hu-t^ls  from  tbo  alimcuinr^' cuoal,  nnd  therdbr*  to  ft 
larjl*  cxunl  num  (bod,  mid  tbe  remainder  Invin  ibc  body  at  lar^  ThiM 
caleulatjons  are  based  on  un4rertain  dnia.  and  cannot,  therefore,  be  taken  as 
uf  exact  value,  but  we  may  uw-  them  for  the  sake  of  nn  iiluslmlion.  Thus, 
in  a  RUU)  of  avera^  weight,  that  is,  nboul  iri4  kitn«„  the  •|uautiiy  of  blood 
(t  S>*  I  beinR  -^  of  tlie  body  weit;bt  is  about  I'i  kilod.  Tbe  <]uantity  of  lymph 
or  chvle.  therribre,  disdiaraed  into  tbe  blood  in  an  hour  would  lie  according 
to  ihn  calculatiun  half  a  kilo.,  or  somethinjr  ietu  than  hall'a  litre;  and  since 
the  duw  nuat  vary  eooaiderably  iu  the  twetily-four  hours  would  be soowtimM 
l««t.  and  therefore  aonetimea  even  nwre,  than  this. 

7%e  MottmenU  of  Lymph. 

i  SOI  .MakiDi*  every  allowance  for  the  uncertainty  of  the  calculation  d«. 
lailtil  in  tltc  prcceiling  paragraph,  it  is  ohvioii*  that  the  lymph   nivn  flow 


rnx  TISSL'Bfl    AJttt   MKOHAMISKS  Of   UIORftTIOK. 


will)  a  utA  incotiaiilerable  rnpidity  (if  we  Uke  abaul  half  the  above  eaiiiuato. 
the  rate  will  Ik  about  •'i  c.c.  per  miouCe)  throuKli  tlie  iboracic  duct,  and 
iberefAre  muHt  also  be  cootiuually  MreamiiiK  into  that  duct  alont;  the  rarioas 
lymphatic  channolH  fruai  the  inaiiifoM  IrniuhspaoK  of  lix  body.  This 
onward  proKreitii  o(  the  lyii)|>h  i»  deu^rniiiied  l>]r  a  variety  of  circumilaDces. 
Id  llie  finl  |»Iho«,  ibe  remarkably  witle-«pre«d  preMoce  of  valves  i$  267)  in 
the  lyra|>haiiu  veiscU  uaiiM^  every  prewiire  exerted  uu  the  tiasuee  in  which 
they  lie  bi  its*i»t  in  the  prapuLnon  forwHrd  uf  the  lymph.  Itence  all  iuub- 
nihir  aiovemviiU  increuo  the  Itow.  If  a  caitula  ba  Inserted  in  une  of  tJie 
Ull^r  lyinpbalic  Iruiikfl  of  tbl^  litnb  of  a  d<%,  the  di>tcharg«  of  lympli  from 
tbo  cnntila  will  be  mon;  dUliiictly  iiicrMMed  by  inovemenls,  even  pasaive 
mrivcmmt*,  of  tlic  limb  than  by  nnylhinit  <'l»v.  When  we  oome  lo  speak  of 
tlw  entrance  of  chyle  iiil»  the  liKrti'iil  railiclcn  of  the  villi,  we  sh«1l  tee  that, 
Rt  alt  Rvonu  according  to  out  vivw.  lh<-  imiiu-ulnr  fibred  of  the  villiia  act  aa 
■  kind  of  muscular  ptimp,  driving  lh<'  diyli:  p^mi  the  valvnd  «nd  of  the 
Ucl«al  nulicif  into  the  lymphntic  nnnl*  boluw.  [n  niKlitian  to  tin-  preMnoo 
of  vaJva  along  the  course  of  tht- vtsmU,  ihooponing  of  the  thoracic  duct 
into  the  vonoui  Byetem  is  guarded  by  n  valve,  so  that  everv  i«i.-un<>  of  lymph 
or  chyle  from  the  duct  into  the  reins  becomw  itself  a  help  to  the  flow.  In 
the  Mcoiid  place,  we  have  already  seen  that  the  blood-prcmiire  in  the  oanil* 
Inries  and  minute  veeseU  ia  considerably  greater  than  that  in  the  largo  veint, 
such  as  the  Jugular;  in  fact,  this  difference  of  prtesure  is  ihe  caus<^  of  the 
flow  of  blood  froni  the  capillaries  to  the  heart.  Now  the  lymph  in  tbo 
lymphatic  spaces  outside  liie  capillaries  and  minute  vefseU  undotibtedly 
Btanda  al  a  lower  pressure  than  the  blood  inside  the  capillarias ;  otherwise 
the  tranaudalioa  from  the  blood  into  the  lisstros  would  be  checked ;  but  the 
diflhrienee  is  probably  much  h»~*  than  the  dilfereuee  between  the  pressure  io 
the  caplllarisi  and  that  in  the  liirgn  venoux  trunks.  So  that  the  lymph  in 
t}i<!  lyntjib-Hpucea  of  the  tiMiniM  may  be  c^onsidered  as  itandinjt  at  a  hi{;ber 
pruraiiri-  than  the  blood  in  the  vemiuH  trunks,  for  instaoee  iu  the  jugular 
vein.  That  ii  to  nay,  the  lymphiuic  reaaels  asm  whole  form  a  system  of 
channeln  leading  from  n  region  of  higher  preaure,  vix.,  the  lymph-s|>aoes  of 
the  tiiwne*.  Co  a  rcKiiHi  of  louvr  pnMure,  vU.,  the  interior  of  the  jugular 
nnd  subclavian  vcnis.  Thi#  dil!erencc  of  pre«4ure  wiU,  a*  in  the  case  uf 
the  bloiKlvcufH^ls.  aiitse  the  lymph  to  tl<>w  onwanl  in  n  continuou*  stream. 
Further,  this  How,  caiucd  by  the  Io¥mcM>  of  the  ntciin  venous  presaiire  at 
the  subclavian  vein,  will  be  iMiited  at  every  iwninilory  movoniml,  since  at 
every  iiis]>inition  Ihe  prmsure  in  the  venous  trunks  becom«»,  as  «*  >luUl  aee 
in  dealing  with  respiration,  uenttve,  and  thns  lymph  will  be  sacked  in  from 
ihe  thoracic  duct,  while  the  increase  of  pressure  in  the  enaat  vein«  during 
cxiiiratioo  is  warded  off  from  the  duct  bv  the  valve  at  m  opening.  In  the 
third  |>lace,  the  How  may  be  incrmsed  by  rhythmical  eontrnctions  of  llie 
walls  of  the  lymphatics  ihemseivcs,  which,  as  we  have  seen,  are  remarkably 
muscular;  and  the  peculiar  interlacing  of  the  muscular  fibres  above  cmcI) 
valve  suggests  that  the  walls  here  act  nl^er  the  fashion  of  a  tiny  heart  and 
by  a  rhythmical  systole  drive  on  the  Huid,  which  by  the  action  of  the  valve 
below  collects  at  the  spot.  We  have,  however,  no  experimental  proof  of 
Uiii ;  for,  thoaj(b  rhythmic  variation*  have  been  observed  iu  the  Ucteals  ol 
the  mesentery,  it  is  maintained  thai  theae  are  umply  passive,  i.  e.,  caused  hj 
the  rhythmic  perii^tallic  action  of  the  inleatine,  each  oontractjon  of  the  in- 
tetitine  fllling  the  Ivrnph-chnnnels  moK  fully,  and  are  not  due  to  contraclioiu 
of  tlte  walls  of  the  lacteal  vtascU  th'mx'lvcs.  In  tume  of  the  lower  animals, 
for  tnstanee  in  the  frog,  llie  rauseulur  walls  of  the  vcmcIs  are  develoj>ed  at 
placM  into  diaiinctly  cunLructtlu  propulsive  organ:!.  njiokeD  of  as  lymph* 
naarts.  of  whieli  we  shall  have  suinethiag  to  aay  pnwenily.    Lastly,  it  id  at 


TDK   VATCRS   A^'P    UOVKUKNTS  OP    I.YMPH.  413 

tariopn  fiiT  D«.  oil  the  ilrcnutli  of  the  snnlnny  tliat  nemosis  may  kito  rise 

ttlDcnuKi  preasure  un  one  tide  of  «  <lifl\iiuon  aeptum,  to  flU[t|M«e  thol  tlte 

ntjfnttma  wbidi  give  rise  to  the  appearance  of  lymph  in  the  lyinnU- 

ifMaof  the  luiu«»,  tend  theiowlTefl  to  prnmoU?  l)ie  tl<iw  of  lymph.     We 

hnu  lm«,  und«r  »ll  circ-iimsianoea,  one  or  other  of  thene  cauaw  at  work, 

»rwtiUu|{  n  ci>iiiiiiuul  thm  from  the  lympkalte  nxit*  to  the  great  vein*. 

ntyuv  t<vi-{h<-r  iiillii-ictii  to  drive,  io  mtui,  llie  lymph  friim  ilie  lower 

fabtml  trunk,  ngaiii.-t  the  eAevts  of  firavity,  iiiln  thv  vi>lm  of  thu  neck. 

(a  lb  iipjirr  lim)i  iho  iril1iK'n<t«  of  gravity,  owing  to  the-  vaHt'd  muVL-inent* 

■'iW  limb,  an'  ai>  iH\ta  favorable  to.  «i  oppuced  to,  the  natiirul  lldw  of  tlw 

lynpfc;  hut,  M  m  have  ulruiily  Mitd,  a  loDc-cuiitinui-il    mifuvonililv  ai'lion 

tfpavhy,  Mpwtnlly  in  tl>e  abneDce  of  tbe  nul  of  niDVcmrntn  in  lli«r  skoli-tal 

aiveln.  a»  who«  the  arm  bimfw  dnnn  ml>ti<>nll^M  fur  aunie  liiiit'.  leiiclo  to  ac- 

'vmalatii'D  of  lymph  at  ilf  oriKin  in  tin-  lymph  itjwce*.     The  ntivtigth  of  the 

(tmn  eombinin^  l'>  drive  on  the  lymph  h  Hlrikingly  itbnwn  in  nnimnlii  when 

tlw  UMiracic  duct  u  li|CKturvd :  in  xtirh  cawv  n  very  grrat  clulciwion  of  the 

ly»iJ|>attc  vcimU  below  the  ligatiirr  i:*  nlitcrx'cd. 

f  80S.  Allbough  ibe  pheooDiena  of  divpiiM  and,  perhnpv,  geDcral  cnnridera- 

nader  it  pruhiiblc  that  the  nervous  syglfni  govenw  in  H>me  wny  the 


ttnun  of  lymph,  n-j^iiUtint;.  it  may  be,  not  only  the  flow  along  thi;  dctinite 
Irnph-ranab,  but  ttlmt  (ho  ininsit  n{  plasma  into  the  lymph  »pnct^  and  the 


%fm  of  lymph  ihmce  inl'>  the  definite  camd».  our  knowledge-  on  thoae 
(H^ti  it  very  imperfci:!.  We  have  no  proof  that  the  muiciilnr  fibres  in  tJi« 
««Ue  of  the  lyuphntic  ve«»).>is  arc  governed  by  nerves,  or  thai  the  lymph- 
•pM*«  are  influeitecKl  directly  by  nervous  action ;  and  muet  of  the  atteiDpts 
to  detDonsirate  iiny  direct  action  of  the  nervous  syttem  on  the  lympliMMB 
Imtb  hilJKftii  failra. 

It  it  very  difficult  to  diasodate  any  lueh  direct  action  fW>m  an  io<Iirect 
infliKnee  through  vnaomotor  ebunKM:  for  the  mnditiou  of  the  viueular 
I  •TMrm  largely  affects  the  forniatioii.  and  henc<-  the  flow  of  Ivmnb.  Tbuti  if, 
I  (n  a  dng.  canuin  having  been  plaee'l  iu  th<^  lymphntie  triinitii  leading  from 
•cb  of  the  hind  feet,  thit  »ciaijc  nerve  on  one  aide  u  divided,  the  How  of 
fruiD  the  f<iot  DO  thai  oidc  \»  i:n«ter  than  on  the  intai't  *idc,  but  i| 
sisbod  on  Klimulation  of  the  peripheral  end  of  the  nerve,  the  iliininii* 
bottis  followed  by  a  iinliM.-i)ueiit  increaMi.  The  Mrction  r>f  the  nerve, 
(iMimeer, Ifads  lo  arterial  dilmion,  the  stimulation  of  the  nerve  to  arterial 
ooMlriction :  ami  until  other  reasons  be  xhoitn,  we  may  attribute  tko  in* 
onased  or  diminulMil  flow  of  lyrapb  to  an  incmtnol  or  diminUted  Iransuda- 
IMi  from  the  fuller  or  cninucr  bloodvasels.  And  thi«  interprerlnliou  is 
sMfportid  by  the  fact  that  urn'o  stimalntiou  of  the  nerve  i*  ki  con<]ijclc^l  us 

Iio  md  to  arterial  dilation  (^  KiS).  the  result  is  not  n  diminifibeil  hut  ao 
liiiiiwiiiil  flow  of  lympb.     Acain,  if  the  eorvieul  sympaihclic  in  a  rabbit  be 
dWldcd  on  ooe  siule  and  a  Hijution  of  the  blue  piigment  »ulphindigotal«  of 
nd*.  be  Injected  into  the  venous  system,  tbo  ear  on  thai  lidc  betomea  blue 
tbe  other,  because  the  pigment  pii>t>es  more  rapidly  from  the  blood- 
I  into  tbo  Irmph-Spaces  of  the  connective  tissue,  and  the  bluenece  also 
away  MOlMir  because  it  is  foooer  washed    nwny  by  the  subeeijueDt 
oneoWed  Ivmpb.    But  here,  too,  the  iticmsed  irstisudation  uiay  be  regarded 
Mtamply  ifie  result  of  the  greater  fulness  of  the  bluodvcesels. 

i  303.  The  pMtage  of  nuilerial.  namely,  of  water  ouotaiuine  certain  tnb- 
•tanoes  in  solution,  from  the  interior  of  tbe  bloodveasd  where  tliey  form  part 

•  of  tbe  plaama  into  the  lymph-capillary  where  tboy  are  allied  lymph  fonaists 
»f  twDSt«|is:  tbe  nnieafie  from  tbe  bloodvewel  into  the  lymph-Bpac«,  am)  tbe 
pwvige  from  the  lympli  space  into  the  lymph  ranillary ;  fur,  as  we  liave  sten, 
ii  u  ■■oly  in  paritcubr  plac(>4  thai  tbe  lymph-c«|>iniiry  immediately  surrounds 


414        THE    TISSL'KS    A  K  [I    MECIIAXISMS   Of    OIOESTIOX. 


till-  MoimIvi-.'wI.  Once  iimv(!i)  in  lh«  Iyiii|>>i  dipillnrr  tbe  lym^iti  lincln  ah 
opon  |iHili  ■liiti^  llic  n-fll  of  llie  ]yin)ihatic  iiy>teni.  litil  tab  ooniKL-tioti  betwwa 
the  lvni|ih')ipiice  niid  ilie  U'lupli'diiiillury  la.  Ha  we  Uiive  Mfti).  |>ecu)itir  aivl  »l 
lensl  nol  n  tW-c  niiil  ii|)pn  urn-, 

Tho  pHMHgc  "I"  nintcriiil  fn)m  the  SIikhIvcswI  into  the  lyinpli-tpaee  we 
sprnk  o1"n»  Irniwudnlinn.  Whal  i-nii  w«  «iy  O"  I"  fhcimlumoniiis  procCM? 
Tlierp  arc  two  kiiinvii  {iliTviciil  pniciwifii  with  which  wc  miiy  comiMn  it: 
lUOueion  ihroiigh  n  nicmDninoiis  uv  other  porous  iMTtiuun,  ntiH  iJllrnliua 
llii'dUKh  H  siiniliir  pHrtiliuii.  Ilifl'iipion.  though  iiitliiciii.-c(l  by  fluid  prawure, 
IB  not  the  iJiret'l  result  dI' Hiiii)  prer^iin^  hut  tnay,  on  the  eimtniry.  be  tliv 
cuuHe  or  diflerenem  of  preesuro  on  the  two  sMk  of  the  parlilton,  «»il  may 
ururk  againBl  Oiiii)  preoeure.  When  n  flrong  solulion  and  a  venk  dilution 
iif  salt  are  bepnrntcd  by  a  dilTiiMon  septum,  dittuaion  lakes  plaee  nhelhrr  iho 
fDUimna  of  fluid  be  at  ihe  same  level  on  tbe  two  eidea  of  ihe  e«p<iim  or  at 
ilitt'trc-ul  levels;  and  if  the  columns  bo  at  the  sani«  Iev«l  to  start  Kith,  that 
of  thL'  stniuger  aolutioD  soon  conies  to  exceed  llw  otlier  in  beixht,  od  account 
«r  ihti  osninlic  Aov.  of  witter  t>om  the  weaker  into  tbe  stronger  anlution. 
Filtraliou,  on  tbe  other  hand,  is  the  direct  result  of  prea>ur« ;  nitbout  dif- 
f<>rcneo  'if  preasure  Kllmiioa  does  not  take  place;  and,  the  filter  reuainiug 
of  iho  name  ualure  and  in  tbe  same  cotidlliou,  tbe  amount  of  filtrate  i* 
ilcjH'ndfDt  III)  tbe  ainuunl  of  pressure.  May  we  apeak  «f  the  procav  of 
treu*iidatii>ii  uh  a  nimple  pnicess  of  diftuHion  or  a  siniple  proocat  of  filtnttun, 
tlial  i#  to  my,  cuii  all  the  pheuornena  of  traiiaudalioii  he  explained  a*  nrnpir 
the  results  of  one  or  other  of  ihete  phytical  pn>oc»8e«?  DiSuKion  by  itveCf 
will  not  account  for  the  reaiilU;  for  Iho  pniteids  nf  the  hloiNl-plwinm  arc 
iodiflusihlo  or  very  iieitrly  no,  and  yet  the  lymph  coiiutinii  a  oonifidenible 
(juantitr  of  thwo  priitiridi).  We  have  no  8alislui-l<>ry  kRowledgc  of  the  cxa«t 
c'impoeition  of  lymph  m  it  exist*  in  the  lyiupli -spaces.  In  the  lymph  of  tbe 
larger  lymph-trunks  the  dilTusible  saliDe  Eunstances  are  present  in  about  tbe 
tame  pruiKirtion,  and  Ihe  iDdiffunble  proteids  to  about  or  loss  than  half  as 
much  an  in  bloud-seruoi ;  and  we  may  perhaps  atsume  that  tbe  lymph  in  the 
lymph'ipaces  contnins  relativelr  len  proteids  hut  has  olberwiae  tlie  same 
ompimitiou  ub  bloud-plaania.  Mere  dilfueion  would  not  fci''^  rise  to  n  fluid 
of  Mich  a  nntim-.  <'an  we  apeak  of  IniDsiidalioa  tlien  as  a  filtration?  TIm 
blond  is  un<louhtcilly  (lowing  tbrnugh  tlie  capillanea  and  other  amall  rexaeU 
unricr  a  certain  pn^eiire;  ue  have  seen  (^  llti)  that  the  preMurc  1*  rouelily 
epcaking  al>ant  30  mia.  Ilg. ;  and  it  would  be  ponible  to  aelectaucb  a  filtor 
or  piirou«  partition  a*  would  at  about  this  praHure  permit  the  pawngc  of  a 
certain  qiinotily  of  ihi-  inorganic  and  oryatnlline  cimittitiienls  of  hlouii-plmuna 
to  paw  through  in  company  with  a  relatively  nmnllrr  fpnintity  of  the  prot«ds 
and  a  large  quantity  of  the  watrr,  the  red  and  white  ourpuiclcw  being  ex- 
cluded. Such  a  Hltrnlc  would  Iw  morR  or  let*  of  thr-  nalnrc  of  lymph  ;  and 
80  far  wc  might  he  justilicd  in  ip<-nking  of  the  Irunmidntion  of  lympb  aa  a 
prooeeaof  KltratJoD.  But  ibo  trani'it  through  tbe  living  wall  of  the  blood- 
venel  ia  aflboted  by  circumstaocrs  in  n  manner  w>  dJHcrcnt  from  the  manner 
in  which  the  sane  circumstances  nflijcl  the  transit  through  aii  onlinary  lifeloK 
filter,  that  we  gain  but  little,  and  may  be  led  into  error  by  sfteaking  of  (he 

grocer  as  a  HltralJon.  Hulntanees  in  solution  or  otherwise,  paas  through  a 
Iter  nlien  the  pmeure  is  sufficient  to  drive  them  througn  the  pa»ia>(e> 
funiidhed  by  tbe  nilersticeH  existing  in  the  substance  of  the  filler.  In  tbe 
cn»e  (if  an  ordinary  filter  the  substance  of  the  tllter  is  within  liniiu  ii&rma- 
tieat,  and  Uie  ixiMages  correspondingly  ooDSlant.  The  livio;{  walln  of  a 
Mpillary,  however,  in  aot  a  cmatant  unchanging  thing.  The  e]>ilbelioiil 
plates  mid  other  elcncnta  whieb  conatitule  it  are  alive,  and  being  alive  are 
L<oHliniudly  uudtrgoing  change  and  are  especially  subject  to  change ;  mora- 


^^^    'TtlK    NATUBS   AMI    UOVEUKNTS    lU'    I.YIiiril.  415 

^Mi^l  «v  httxt  H«n  (^  22,  2S>,  ibe  vascular  walls  atipeiir  lo  Ik-  raiiiiriuslly 
sdioa  u|iun  nod  Iwiufir  ac-ieil  upon  by  tbe  blouil.  Heiift'  a  elmiigi>  in  ih'o 
blnod  t«ndii  lo  nujc  rhatigM  Ju  l)i«ai ;  am)  thwt-  cliimu;A*  may  mnii'riiilly 
■Act  tn  oi>e  (lireetiiiii  or  au<>tl»i-r  iWir  uc-tion  lu  61t4-n>.  In  an  unlinnry  lilii>r 
bu'lBiae  of  pmnir«  n«ccaMrilv  I'lilnila  incn^-e  of  lillralion  :  in  it  living 
fiter  it  inajr  or  mar  ma,  awl  inc  umc  iiicnuLw  of  [imuiirc  may  ucfMnliiijt  to 
cutnRwUaoea  product  very  diflerent  rcMilt-i  lu  rrgardt  the  traiuudatioii  of 

Tbu  it  ttetm  rcMonablc  !■>  sappoM  a*  we  have  mggoetod  (S  227)  thai, 
'  ihiam  being  iW  Mi»«,  an  ii>ercnm  of  blood-preMure  'hould  iK-«nariljr 
I  tlie  trsiMuiliiiioi)  of  lymph.  Hvnrc  when  a  tmnll  iirlcn-  ililalca, 
•JBM  Uw  praaurv  in  ihii  >till  emalk-r  branclHw  nml  capillnrica  of  tliut  nrtcry 
ia.  ■•  «v  bave  toon-  tlum  onco  |>otnlod  out.  incmuoiJ,  inor«  lymph  appean  in 
tbe  lirnpb-^«4v  ;  indrod  il  is  oda  of  the  main  ptirpoecs  of  ibe  widMiing  of 
tmrnli  artvnw  to  eupply  tbe  elements  of  the  tiwne  with  more  lymph,  lliai  U, 
wiUi  more  food,  llut  it  does  doI  Ihorefore  folluw  that  under  all  circum- 
Mabm  widmtng  of  the  artery  should  increase  th«  paaeage  of  lympb  :  Mme- 
tl^Bg  mar  oceur  to  countersct  tbe  natural  eR^ot  of  the  inoreamd  prawure  ia 
Ibe  lMoodT«eMlB.  An  instance  of  this  seems  to  be  ait'urded  bv  tlie  case  of 
tb*  •nbmaxillary  eland,  witeo  tbe  chorda  nerre  is  stimulated  while  tbe  gland 
b  Qftder  tbe  influeiii.-e  of  atropine.  Aa  we  have  aeen,  tbouk[h  the  arteries 
dilate,  DO  fecivtioti  ukis  |ilac« :  and  ne  cannut  explain  ihi.-  aWnoe  of  a  flow 
bla  the  alveoli  hy  HU|i|Hntn)j:  tliat  the  extra  arnixmt  of  lymph  which  would 
ia  nonaal  drcunulancu  fiirru  part  of  the  secretion,  and  in  tbe  case  of  a  fairly 
eopfaaa  aecrativo  would  Ix;  cotwiderahlo,  now  panea  away  by  the  lymphatic* 
wiUtout  reaobioK  Ibe  cella  of  tbe  nlvei)1i,  fur  in  micIi  eiMin*  no  oxtra  flokv  in 
the  lymphmlka  leading  from  tbe  gland  lia«  beat  olurrvLiI,  and  ihrn-  ii^  no 
accnmulatioti  of  Iymj4i  in  the  connei-iivc  tiMUe  of  the  gland.  Apparently, 
fur  Mime  n-nwn  or  other,  in  spilo  of  the  increased  prca»ir«  in  the  hlood<re»- 
H^BOn  lympb  than  umibI  Aik-s  nul  pase  into  the  lymph-spaecs. 

tImo  again,  as  we  ahall  presently  have  occa^on  to  point  out,  an  increase 
nTprnmiv  ia  the  blooilveneU  produced  by  c^tructioo  to  the  venous  ontllnw 
ie  onicll  atore  efficient  in  promolingan  increase  of  IransiidalioD,  al  all  events 
an  alnormal  increase,  than  is  an  increase  of  arterial  pre^ure  ;  and  the  dif- 
fiircs«e  between  the  two  vases  ap[)e«rs  to  be  too  great  to  be  accounted  for  on 
iIm  firouud  that  an  obatruction  to  tlie  reaoua  outflow  raises  the  preasure 
within  tbe  capillarivtt  and  small  veeseU  more  readily  and  to  a  higher  degree 
than  diw9  tbe  widening  of  the  arleriea.  itloivorer  that  olMtrui-tion  to  venous 
oMAow  does  not  produce  il«  eflects  In  the  way  of  transudali'in  niniply  tad 
BMnljr  by  raising  the  capillary  pnMiire  in  shown  by  thv  fact  ihjit  the  same 
•notfnt  of  ob«trncti<m  may  nr  may  not  give  riM>  to  exceasive  traiuildatioa 
■ecording  lo  ttie  ctmdiiion  of  the  blood  or  other  drcumstanoM.  For  instanee, 
tbongh  Uia  ofaatnioliun  prodaocd  by  ligaturing  a  vein  frequently  eausasvx- 
caoiir*  tntMudaiion,  il  dooa  not  always  cause  it,  aixl  the  femoral  vein  of  a 
doc  may  be  licaturvil  without  anv  cx<r<V!<ivo  iraneii'lalion  taking  place;  vet 
if,  after  the  Tignturc.  crrtnin  cluuiges  be  inductil  in  lh»  hl(wd  exceeuro 
tnuHddalMii  occurs  in  tbe  log,  the  Tain  of  which  hia  been  ligatured  but  not 
■laiiwlurri  I'tHUting  toward  tbe  mme  conclitnon  ia  the  fact  that  exceauve 
tmodatton  njnrn  readily  occurs  when  a  roiu  is  plugged  by  a  thrombus 
arising  from  abnormal  conditioos  of  the  vascular  system  than  when  a  vein  is 
Mmply  ligatured.  And  in  genera)  we  may  my,  and  this  is  a  point  to  which 
we  tball  mum,  that  two  things  ehieflr  determine  the  amount  of  transuda- 
tion: the  preasure  of  the  blood  in  the  bloodvessels,  and  tiK-  oondition  of  the 
vascular  walls  in  relatiofi  to  Ibe  blood,  the  latter  being  at  least  lu  important 
as  the  former. 


41ll        TKK    TISSUKS    A N' 1>    MKCHANISMS   or    DIOKSTION. 


Atiutber  a«pect  of  rW  matier  morenTer  deserves  attention.  In  tfltralioo 
the  iiioveiueDt  take^  pIuL-e  lhrt>u|;[h  the  lilter  in  uiie  diremtion  unlv.  irbureiu  iu 
the  liviu(;  body,  the  na«sa^  of  mnlerinl  UimuKh  the  uapillary  wall  mkM 
]>!nce  ill  tun  uppoHile  directions.  In  ull  the  tiwue^.  [htiti);)i  taum  iifrhup*  in 
cerlaiu  tissues  lliaii  iu  ciUiera,  th«  passage  IVoai  the  hloiHlvv9M.4  into  lb<? 
)yni|ih-spnce  h  aiXKiuipanied  by  a  (Mwage  ttrvm  the  lymph-Kpuf-e  into  itir 
liliiiid ;  while  food  for  the  tiiaue  pones  in  one  directiim,  u*a»Ut  pni'lucla  p*i«i 
in  the  other.  In  n  secretiug  tcl^nd  the  (greater  piirl  of  thv  lymph  euming 
from  the  blood vexM'U,  the  water  aud  other  mutter*,  ptuv  away  into  the  In  men 
of  the  atreoluK  iil'ler  uiiderj^iiig  chanfcc*  in  the  rell ;  but  eren  in  nuch  a  caw: 
there  in  »ouie  return  from  the  cella  iiil»  tJie  liloodvrMoIif,  nrl>onic  a<:(d  for 
instance  if  nothing  eW  in  given  up  by  the  cellH  to  the  blood :  mid  in  auch 
orgiuis  ns  a  mnsck-  nr  the  liver,  ibt;  backunrd  Klreum  of  mnleriul  from  ibi- 
tJMite  ti>  tlict  hl'jod  is  cxtriixive  and  inijioTtiint.  Moreover  this  bookward 
strain)  workH  agnin^t  pn^Miirc;  iiidetMl.  m  niny  be  «cen  in  a  uuscle,  it  u 
when  the  blumJve^>sel.'>  iirc  dilat)<d  and  the  prvnnru  in  the  eapillarim  and 
itiiall  vresel*  high<*t,  u«  during  and  aflcr  the  cuntrnction  of  tht>  muscle,  that 
the  pBa88g«  from  the  liMue  into  the  blond  in  most  ciier)>etic.  Many  of  the 
waele  products  of  tho  titane  are  it  la  true  diffusible,  and  we  mi|^ht  be  tempted 
to  say  that  while  the  lymph  which  feeds  tbe  tissue  traverses  the  vaHcular 
wall  by  liltralion  iu  tbe  direction  of  prewure,  the  wnste  products  return  to 
tbe  blood  Hgaiust  pressure  by  diffusion  ;  but  siieh  a  vieff  cftnnot  al  preoent 
be  regarded  as  proved;  and  if  it  be  true  as  is  mainluned  by  eome,  that 
lyiupli,  including  the  proteids,  may  at  times  be  reabsorbed  from  tJie  tJsaue 
into  tbe  bloodvessels,  it  is  distinctly  contradicted.  We  shall  have  to  return 
to  tliis  QLiestioii  when  we  coiue  to  deal  with  tbe  secretion  of  urine;  but 
meanwhile  we  may  adopt  the  cuDclusion,  which  is  especially  supported  by 
the  phenomena  of  disease,  that  while  dillbsion  and  filiraljoo  plav  their  n.- 
sfWelivii  parts,  flitfusibliT  iiubntaiiw"  pawing  in  and  out  of  the  blood  cnoro 
readily  tnan  indid'iiMhle  Mibilancm  and  an  incrcaw  of  prtwurc  tendtng  to 
to  pn>motr  trunnudntion.  the  condition  of  the  vaKular  wall  so  profoundly 
iitflucnct«  tbe  tranxit  of  material  h«  to  render  the  proccM  vcrx*  complex. 
We  may  probnblv  regard  it  ns  Urn  complex  In  be  compiircd  even  with  liura- 
lioii  through  a  filter  capable  of  widely  clianging  in  texture  from  lime  to 
time,  and  ns  niore  nearly  rrscmbling  the  proocn  of  >^ccretion. 

C«uceniing  (he  passage  of  the  Ivinph  from  tho  eonbnci  lyrapb-siMioes  into 
the  open  gangrcnys  of  the  lyniph-capillarics  wc  know  very  little.  If,  as 
some  think,  tbe  c«vity  of  tho  lymph-canillnry  is  "hut  otT  on  all  sides  and 
oompletely  by  a  continuous  lining  of  sniiioua  epithelioid  plates.  tbeD  the 
passage  from  the  lymph-space  into  it  must  be  rc^rded  as  a  sort  of  repetition 
of  the  passage  from  the  blood-capillary  into  the  lymph-snioe  as  a  second 
transiidulion.  liut  if,  as  others  think,  and  as  on  tbe  Wnole  seeoiB  mote 
probable,  tbe  lymph-«pac«8  open  at  places  directly  into  the  lymph-capillaries, 
tlie  passage  is  a  simply  mechanical  atfair  determined  by  the  freedoot  of  these 
o|)enioga. 

In  either  esse  the  flow  from  tbe  lyuipb-spaces  will  ba  ftcilitated  l>y  all 
erenta  which  promote,  and  checked  by  those  which  hinder  the  How  of  lymph 
along  the  lympb-capillurie^  and  tbe  other  lymphatic  channels. 

^r^  ouiy  here  remark  a*  iulluencinjc  the  ({uantilv  of  lymph  in  the  lymph- 
spaces  aiMJ  veiwels  that  tho  ijuuiiity  of  lymph  laVeu  up  from  tbe  lymph* 
qMe€s  by  the  actual  elements  of  me  liwie  mav  vary  considerably!  We 
rentarkeil  in  g  30  on  the  puculiar  relations  of  living  tissue  to  water,  and 
tht^n.-  are  reasons  for  thinking  that  the  very  substance  of  a  cell  or  a  fibre 
(a  muscular  fibn-,  for  inxlann.-)  may  hold  in  ilKelf  n  larger  nuantily  of  water 
at  one  lime  than  at  anollxr.    Tlie  water  thus  taken  up  or  given  out.  nod  tbe 


MOVEUE.VTS   OF   I.YMPII. 


417 


» 


■otatutn*  which  may  tw  rarri«)  in  ^ituticm  hy  that  water,  ooroe  fnini  and  jto 
U>  thv  lymph.  The  cotiditiou  uf  tliv  tiioue  ilHurminM  by  iUelf  ihe  unxmiit 
of  Irnipli  IN  iho  lytti|'h  tpaoc*. 

I  Mh.  I'ntlvr  ihv  intliieitM  of  all  thmb  hktbI  iK-(ionii  tlio  lymph  in  ths 
TmnaoM  lynph-mm*  ul'  the  t>oi)y  varicH  in  Buioiint  fnim  lime  bi  time,  but 
noder  ounpil  nrcuinxiancM  never  cxttwd*  certain  limit*.  Unilur  juithu* 
kvi^  ooodilioot  lbnM>  limit*  may  be  vxck-CiIoiI.  aiiri  thu  retult  in  kouvo  a* 
■■■inMOr  drafwy.  ^inilar  vxcci»iv<'  acoiimtilntioiis  of  lymph  may  occur  nut 
in  Uw  unlinary  l^pb^paca*.  btit  in  tiitvr  largiT  lympli-i|iHcai.  thi;  wiroiu 
aarilica,  any  iarK«  •xom  of  fluid  in  iha  pvritoQnd  cavity  being  kuown  M 


to 


Tht  paaiblo  nuta  of  oidvma  arc.  nn  lh«  one  band,  an  obstnintion  to  th« 
of  lymph  I'rom  the  lymph-spnrw,  nnd  on  tbf  othrr  hand  an  irxoxwivo 
tniMDduioii,  thr  lympb  enthtiriiig  ill  (lie  lymph-spacM  fiuU-r  than  it  can  bo 
(mrrifd  away  by  a  mirmal  t!ow  ;  ivilh  t\w  former  tlio  lymphatic  tyiiUsm  itacif, 
vith  ihr  latter  chi«(lr  the  vaiMriilnr  vyMcin  is  «)DC0niei1.  A«  a  luattor  of 
bet,  huwcvcr,  imicma  is  almost  iilwnys,  if  not  always,  due  to  abnormal  oondl* 
tioaa  of  tbo  vavcular  srslein,  and  ie  the  result  not  of  hindered  outflow,  but 
•f  MXcnaive  liansudalton. 

Owing  li  ihv  niintenius  anastomOMs  of  the  lymph-vrw«U  nnd  the  conso> 
uaetit  HUblishntrni  of  oollateral  Ureanis,  obstruction  iti  tin-  lymph-pMNi^^ 
ihiiiiwlini  rmrely  if  vm  give*  riae  to  isdema :  and  it  mav  be  here  rviiinrlceil 
that  inring  to  the  sane  me  oollateral  communication  iM^twccn  ibi'  lymph- 
Ttaela  tbe  labyrinthine  piuwages  of  the  lymphntic-gtnnds  do  not  oiler  (he 
a«ciuo»  obatacio  to  the  onward  flow  of  the  general  lymph-strenm,  aa  might  at 
ifM  ai^t  bewppoaed.  Nor  have  we  at  present  any  knonled)^  which  would 
lad  oa  to  mppoae  that  any  phy»iolo^teal  changes  in  the  walls  of  tbe  lymph- 
•lic^TtascIs  or  of  the  lymph-capillanea,  or  in  the  lymph  spaces,  by  giving 
rtee  in  aomo  way  to  ub»tnch*  li>  the  flow  of  lymph,  ever  lead  to  an  accumu- 
latioii  nf  lympb  in  the  latter. 

Otw  kind  uf  u-ilema  wa  haro  already  loufhvd  ujmiu  in  6i>eaking  of  tbe 
cspUlarj  cireulatiuu  ($  183),  viz.,  the  "inllammatorr"  a-deiua.  In  llua 
kiod  of  ndetDB,  owing  to  cluwgoa  in  the  vascnlur  null*,  a  lur^L-r  amount  of 
tTBtnudation  puaea  ium  thu  lymph -spacea.  and  that  traniiudBtion  Ih  richiu^  !n 
protcid  matter*,  and  cunlaiiin  a  lar^r  nm'>unl  nf  the  fibrin  fnct'ini,  or  at  all 
•VWtt*  i»  much  more  distiiietir  ciinguliihle  than  onliunry  lymph,  n*  well  nt 
crawdeil  with  migrating  oofpiiaok*.  Atlictl  Ui  this  itifla minatory  mlema  i* 
tbt  iocteaae  of  lymph,  abn  appurenily  changed  sontewhat  in  charnrtrr, 
which  appeu*  ■•  "eH'uaion  "  in  the  serous  cavities  when  theae  are  inl1ainc<l, 
M  in  pleuriiy  and  peritonitis. 

One  of  the  moM  common  forms  of  redenin  is  nn  itdcnin  ■>f  ]>riinarily. 
ibough  not  wholly,  iDcchaaiml  origin— wdenta  arising  from  obelniction  to 
Uw  v«ioui  flow :  undiT  tbtee  circuiiMtancM  more  lymph  passe*  into  the 
lympb^paioca  than  the  lyiDph-reasela  are  able  to  carry  away.  If  tbe  femoral 
vasn  bo  tied  tbe  1^  may  become  oedematoua,  and,  as  we  have  snid,  (edema  is 
a  commca  rtwilt  of  the  piuggini*  or  obeimction  of  reins  ihrongh  disease; 
tbe  ondema  which  w  so  comnton  an  anwro  pan  intent  of  heart  disease,  involv- 
Utcobat ruction  to  the  return  of  vciuhib  bluod  to  the  right  side  of  the  heart, 
au  Ibe  aacitea  which  folluus  upon  hiudmnce  to  tbe  porlal  flow,  are  instanns 
of  ttdema  of  this  kind.  We  have  already  remarked  on  the  relation  of 
traosodaljan  lo  btoixI-preBMiio.  and  in  vi-iuhiv  ultsi ruction  the  ri&e  of  prcMure 
witbia  the  amall  lilmxlvessels  i»  dwintinisht-d  from  that  due  to  arterial  dila- 
tion by  being  accum|ianied  with  a  want  of  ade<|Uaie  renewal  of  the  blood ; 
this  probably  afiects  the  epiihelinid  lining  of  the  bloodveieels  in  such  a  way 
aa  to  increase  the  trantudaiivn.    And,  tniWvd,  as  it  aetn  la  caae  of  In-urt  dia- 

■It 


TBB  TlSSUSa   AND  HBCffAKISMB  OP   DTOBSTIO?!. 


our  uiih  )ir(i1oDgcd  or  re|>eKted  venom  ob^lruclion,  tlic  uvlema,  a*  liin«  i 
on  >ti<l  ilu'  liiwiie*  b«ciime  impaired,  lit  mure  eiisily  i-xdted  nml  vritli  ^ 
Oifliciilty  n^iDi^v).''!,  lliuiigh  the  nctiiitl  iiiiiKtiiit  nf  ulntrii elicit).  ili«  actiiK) 
incrpni''?'  of  pmioun;  in  tlin  .imiiU  vuiucU,  ruiuaiiiii  the  Mnii;,  or  nt  Ituul  i»  uut 
pmpiirtionatrly  iiiirrcii!«?'l. 

Slill  nntitluT  kiiiil  of  (nleuin  is  oni^  Htic  to  chaugn  t«)ciii)r  placn  in  the 
blood,  quite  apart  from  variaLioDs  of  Mood-jirmure.  Tliin  kind  of  •nlema 
ia  »een  in  eutiie  diwMiws  of  the  kidiirr,  in  *'  Bright's  iltfcuc"  fur  iiMiano*. 
In  Auch  cases  lliu  blood  ocinLnin«  \v»  jirotcid*,  and  indeed  1cm  solida.  i«  more 
watery  and  of  lotrcr  specilic  cnivity  than  i«  normal.  But  Uto  tcdcnui  is  not 
iu  lh«4e  ea8e«  lo  bo  cxnliiinciroii  tlit?  viciv  thnt  the  more  wat«ry  blood  ponn 
more  readily  thruni;h  llio  capilUry  walls,  for  ll  mnv  Ih.-  shown  ozperimvnliUly 
lliat  tli«  mere  thinning  of  the  blood,  as  by  the  injection  of  noniinl  ealiiw 
•olutton  into  llie  blooil vessels,  will  not  at  once  lead  to  dedeaw,  at  least  in  the 
limbs  and  trunk,  and  it  is  these  which  iu  Urifilit's  disease  especially  become 
<BdciD&toue.  Iu  all  prohabililr  the  oedema  of  Bri;Fhi'8  disease,  if  it  be  really 
due  to  the  abnorniat  character  of  the  bhmd.  ih  produced  by  tlie  shnorrnat 
bluod  10  sotiug  on  the  bloodveseels  that  these  allow  a  transudation  i-reBter 
tlion  the  normal. 

But  ihow  are  patholofrical  qnestions  into  <nhich  we  must  not  enter  here. 
We  have  toudiea  u[iou  them  beoau»e  ibey  illustrate  the  important  procisoe* 
taking  place  in  the  lyinph-apocea,  and,  as  we  have  more  than  uncv  inuvtied. 
the  lymph  in  the  lyupli-BpaL'ee  is  the  midiUninan  of  all  the  tiwuM,  ami  b4>noe 
fad*  ilUiitiniting  the  laws  which  govern  the  flow  of  lymph  intn  and  out  nf 
the  lyniphKpacM  are  of  flindamental  phyAiulogical  iuifHirtnnce. 

S  SOS.  Lijmjih-hrtiTl*.  \n  the  IVog  and  nlhcr  amptiibiii  and  in  reptiles  iIm- 
flow  of  lymph  into  the  venouH  iiy»teni  \»  awiMcd  hr  rhythmically  pulsating 
muscular  lyiniih-hi.'artK.  which  ]>r(«i^nC  ninny  ciinuus  UDalugies  witli  the 
htoud-hearl.  The  frog  poasMsa  ti>ur  lymph -hvarls.  Of  these  two.  belnugini; 
tu  the  hind  limbs,  arc  placed  one-  on  each  side  of  the  coccyx  near  iu  end, 
and,  being  covered  only  hy  apiint'uriMis  and  the  skin,  may  without  diaseccioo 
be  seen  heating.  Two  anterior  ones  arc  placed  on  the  transverse  puimwn 
of  the  third  vertebra,  and  are  covered  from  view  by  the  shoulder  ifirdle. 
Kach  lyitiph'heart  is  a  more  or  less  oval  sac  lying  in  one  of  those  lymph  naot 
or  cavilieii  lined  with  sinuous  epithelioid  plates,  which,  as  we  have  taid,  are 
preeeut  iu  the  frog.  It  is  c<inlinueil  at  one  end,  by  an  oritioe  guardbl  with 
valvea,  into  a  small  vein  which  opens,  in  the  case  of  the  posterior  hedit,  into 
ft  crural  vein,  and  iu  the  case  of  the  anterior  hcarta  into  a  jugular  vein. 
The  undl  vuuoiats  of  muscular  tibres  arTauh-ed  in  a  plexiforni  nuiuucr  and 
snpportcil  hy  a  considerable  aniunnt  of  cunoeolive  tissue.  Thuae  iit>r««  an 
Btnated  and  hrancheii  and  are  intermediate  in  character  between  cArdisc 
and  skeletal  muscular  librea.  Nerve  fibre*  terminate  in  tho>e  muscular 
fibres,  anil  the  muscular  wall,  unlike  that  of  the  blootj-heart,  :»  viipplied 
with  Lttpillnry  bloodveiwela.  The  interior  U  WotA  with  epithelioid  plates  of 
MKUous  outline,  and  tlib  lymphatic  lining  io  continued  along  a  number  of 
openings  or  porcH.  by  which  the  cavity  of  the  hcan  opens  into  the  surrounding 
)ymph-«p«ce.  Whej)  the  XtviWl  cotitnuits  the  content*  are  ilriven  into  tho 
vein,  tlie  lyniplintic  pore*  being  closed  by  tli*'  np]>ttiximntioti  of  lh«  cod- 
tracting  muwular  fibm ;  when  the  heart  dihites  the  fiuid  in  the  rein  b 
prwenteil  from  returning  by  the  valve*  at  its  mouth,  while  the  lymph  enters 
readily  from  the  iium)un<ling  space  through  the  now  open  porea.  In  the 
flrojlg  racular  IvmphntSc  vcsmh  are  scanty;  Ticncc  these  lymph-heaitB  beeome 
of  ooostderahlc  imporlnnce  in  promoting  the  How  of  lymph.  The  Irinpb- 
hearts  of  reptilia  arc  i>iniil>r  in  siniaure  and  function.  In  the  fn>g,  in 
which  they  nave  been  ehicHy  Mudied,  tbo  action  of  the  lympb-bearta  is  iu  a 


iXTARV    CANAL. 


419 


I 


tBMMr*  dvptixlMii  Ml  tbi>  »piiiii)  r<>rH.    T}i«  potieriur  Ivrnph-hcnrU  beUing- 

iac  b)  U>*  bind  limb*  »rv  •.'miitMlcd  by  nieitas  of  tbe  (Iclimic  leoib  pair  of 

»fml  twnr«i>  wtih  n  R%Hon  ofihccartloppcMtc  ihf  nixili  »rwvfiiih  vtrrtcbrit 

ftflMH^Rwayibnt  M-cii»ii  atth*  oerrc  oratHniction  of  ihr  jMiriiditar  rvgion 

^if  llicotnluiiiiMniiliiordiidmvi  iWinidivity.  Thi?  aiilori'ir  [Kiirnn-  »imihirlT 

«nODfcte)l  wttb  a  region  <■!'  iIm'  iipinal  fun)  ii|>]K»itL'  tbc  thinl  vcriobra.    Eacli 

yir  llwnifew  awCTW  bi  tiBvt>«"ci.*ntTv"inibi'  An>iiial  cord;  but  it  in  probable, 

ViMMigb  obMrren  are  niA  whittly  ngrcil.  tlinl  thv  bi'srti>,  nftcr  dratriiclian  of 

^bair  spinal  cvntre,  ultimately   rfsame    ihrir  rliythmic  hfMf,  «o  tlinl  tbe 

^ItppDilmce  of  their  iictivitr  on  tltr  8)>in]il  cnitra  is  Dot  aii  iibmlute  one. 

Ijkr  ibe  beart  of  t)i«  blootf-sycteni.  tlw  lympb-hcnrts  may  be  inhibil«t,  and 

that  ill  a  Ktlex  matiiwr,  the  iiihihitioD  ocntrtr  being  morvover  in  the  medulla 

«l>'i>i)e>l^     If  a  rro|>  be  nrcl'iilly  ohfervod.  the  activity  of  the  lymph-heurta 

«111  be  linind  lo  vary  larj^ely.  and  thcw  vnrinlions  a]i{i«ir  to  be  iu  purl  due 

la  aerxmm  indo«ne«s.  w  that  iu  tliia  n-tiy  tbc  iiiovcmeDt  of  lymph,  and  hence 

iW   ptocMw  uf  abaoq>tH)n,  are  in  this  aniuuil  directly  (le|wii<Ii-ul  on  tbe 

MTTMn  syriem. 

Absori^iok  pbom  the  AuMEicTARy  Canai. 

S  306.  We  may  now  rttura  lo  conrider  tbe  abaoqiliou  of  th«  products  of 
dtewtioa,  tliitt  ia  lo  My,  tbe  paiwmie  of  ihaw  bodies  from  tbc  interior  of  the 
abmrntary  caual.  where  tbeV  are  really  uutaide  tbe  iKxty  prupfr.  into  the 
body  itwlf  For  siniplicity  n  itake  we  ena^  conal<ler  difn-stioti  in  a  browl 
way  aa  tJie  eouvuntofi  of  pmcli>'ally  non-ditnuihlu  pruteids  and  elttrch  into 
BOfv  dtffiiuble  pv^loni^  and  highly  dlfTuiiblc  ^ngar,  and  ua  the  eHiuUifyiug, 
or  dlvirioD  into  minut«  iMrticKv  of  fats.  We  have  reiuon  to  believr  that 
nmt  of  the  sugar  may  be  ebaogml  into  lactic  acid  ur  even  inln  butyric  or 
otbar  scidt,  that  some  of  tbe  protctdB  ar«  carried  beyond  tbe  pvjitone  D>odi- 
6ao  (oto  lendn  and  other  bodies,  and  timt  some  of  the  fat  may  be  HH|>onilied  ; 
bimI  it  may  be  that  some  of  ibc  jiroteid  material  of  Ibe  food  piuucv  into  the 
body  mn  albunii»e  or  even  an  i>anij)efitone.  or  in  some  other  little  changvd 
roMition.  But  we  may  probably  mith  safelv.  fur  jir^wnt  puriiimii^  iiwumu 
tbat  tbe  ctvalcr  part  of  the  proietd  u  l%\)*^^T\iv^  as  peptone,  thut  carbohydrates 
ar«  iiiainly  nb*>irlied  as  sugar,  and  that  the  >[ivater  Diirt  of  the  fat  puaaes 
tfltu  tbe  body  u  emulsified  but  otbi-rwise  uui'ltanjfcu  uentnil  fat;  and  we 
nuy  iwigkct  tbe  other  conditions  i*f  drgtsted  food  as  iub«idiary.  and  as  far 
•a  alaurplloa  ia  concerned,  unimpurtunl. 

W'r  hare  seen  that  twi>  {>a(bi«  iifL-  iigmn  for  thne  products  of  digestion,  one 
by  the  caiiillaries  of  llut  portal  system,  the  other  by  the  hicteals.  It  eannui 
br  a  matter  of  indtArmce  which  oounw  ij<  taken.  For  if  the  products  paw 
bv  tbe  ladenU  they  Ihl!  into  the  general  htiiod -current  aAer  having  under- 
gone only  siieh  ehnngra  ns  ihey  niay  experience  in  the  lymphatic  ayiteoa ; 
while  if  they  piu«  int<i  th<-  [xirt»l  vein  (hev  are  fubjcete<l  to  eerUiin  mwerfol 
inlluenci-s  of  the  liver  (which  we  tilinll  'tudy  in  a  future  chapter:'  iR-tuir  ihry 
find  their  way  to  the  right  fii'le  of  the  licart.  We  may.  tlierefoiv,  euiuider 
ftM  which  iif  the  tno  paths  is.  as  a  matter  of  tact,  taken  by  tbe  m-veral 
products,  and  suliaetjaeDtly  study  tbe  nbecliaiiism  of  absorption  in  tbe  two 

Tlu  Omrte  latrn  by  ihe  Sexvral  I'rodudt  of  Digttlion. 

I S0T.  Prom  wliat  hii*  nlrendy  beea  said  we  have  l>ceu  led  to  regunl  thu 

viUi  aa  tbt  moat  active  nrganr  of  abaorpltun.  and  Iho  ■tructaiv  of  a  villus 

oa  fltrther  to  conclude  that  the  iliffiuible  [H'titoiMi  and  augar  laus, 

lerwlth  lbs  water  in  which  tlwy  an-  (lissolved.  into  the  superfidalty 


420 


THK    TISSi 


placed  capillary  network  of  ilie  viLlna  and  «i  into  the  porta)  anttm,  irbik 
the  merely  entulsiti^d  tat,  unikble  lu  travi^rae  tbe  trail  of  ibe  i-npillarir,  puKS 
on  lu  the  deeD-eeuted  liioteal  radi(;le,  aiiil  so  finda  iu  wny  iiilo  liitr  lympbatie 
ajMeni.  Anu  tbe  ix-aultK  of  obBervHiiuii  and  cxjMtriineni,  an  far  iu>  tliey  ^, 
tupptiri  lliia  vien. 

Fat*.  AIYer  a  lueol  containing  fiit  th«  lyniph  of  ibe  laeleftU  oantaina  fat, 
atxl  IK  niiiv  (udled  cbyla ;  and  lh«  ricber  titi;  niuil  in  fill  lli«  ntrire  oo«*picw>iu 
M  tlif  fuC  in  llie  lymph-vewelx.  W«  [-aiirml.  liowL-vcr,  [imvu  that  all  the  fat 
of  a  Picuil  ubwjrlictt  rniin  lb«  allnieutiiry  in  pi)uri.i]  by  tbu  ihorudc  duct  into 
lh«  vcutuii!*  »viit4'ni.  If  ft  iiiutl  nmttiiiiui^'  h  known  (jiiunlity  vf  fnl  lio  given 
to  ft  d»^  and  ihc  »niutl  <|iiuntity  nt'  fal  [irtwiit  in  the  fecn  correepondiiig  to 
tbo  nifaJ  be  MulUriiL'tcd  fnini  thnt  nnimiiit,  wp  can  dcti^rmino  the  anxiiint  of 
flltabaorlicd,  for  we  haw  tio  ci'idcnccl  wliiiU-vcr  tbiil  any  upprtciablc  nm-xial 
of  [at  undergocv  a  ilcstrm-tiv)-  it<»ri>mpoftilion  in  tbo  nlimcnlnry  i-iinnl.  Col- 
lecting by  meaiit  of  a  rjumla  iiiMTli-d  into  tha  thoracic  iluct  the  whole  of 
the  chyle  during  and  nfti:T  the  meal  *u  lung  ne  it  rcniainB  milky,  ebowing 
that  lilt  i«  lieiiig  nbmrlK-d,  we  can  tircertain  the  ijuanlilv  of  aheorbed  ftl, 
nbich  would,  bill  for  the  ojicralioii.  have  pnwed  into  t(ie  Tenoiie  ayatom. 
When  this  hiM  been  done,  a  very  rcmnrkablc  dcticil,  aniutiiiiinj*  it  may  he  to 
40  or  &0  per  cent,  hue  been  obeorveil ;  that  is  lo  eav,  of  every  I'lU  |>artB  of 
fat  which  disappear  from  tbe  aliaieutary  canal  only  about  tiO  parta  Rud  ibeir 
wav  through  tue  thoracic  duct  into  tbe  venous  system. 

Are  we  then  lo  conclude  that  the  mining  quantity  finds  iia  way  into  tbe 
portal  eystem  ?  Now  the  portal  blood  does,  during  digcetjon,  oontain  u  cwr- 
tnin  quantity  of  fat;  indeed,  the  seruiu  ia  itaid  at  tiiuea  to  appear  milky  from 
the  presence  of  fat.  But  the  whole  circulating  bhiod  durin)c  tbe  digntion 
of  a  fatty  meal  coDtaina.  for  a  while,  the  fat  poured  into  it  1>y  iliv  thoracic 
duct ;  and  it  ban  t>een  a.icertaiiied  in  the  dog  that  the  blond  oi'  ibc  portal 
Vtin  during  digistion  coutatnii  not  mure  but  Icea  fat  ibno  the  hlood  of  tbe 
carotid  nrlery,  m>  ihnt  tlit?  fut  nhiub  nppeum  in  the  portal  blood  during 
digestion  if,  (or  ibc  UKWt  part  at  Uywl.  not  fnt  ahM>rl)ed  by  tbu  capillaries  <? 
tbe  aliiuenltiry  cniial  hiil  fiit  ahsorbi-il  by  the  WtenK  Moreover,  when  the 
chyle  of  the  ihoracic  duct  i*  diverlvd  tlirough  a  canula,  and  not  allowed  to 
flow  into  ibe  bloifd.  the  <|iiantily  of  fat  in  the  portid  blood  as  in  the  blood  at 
large  is  very  small  iiideeil.  Lastly,  when  a  villus  of  an  intcMJae  in  full 
digeition  of  fat  is  tn-ateii  with  uiitiic  acid,  fat  cannot  bo  reeogDiud  by  the 
nucroMOpe  within  the  capillaries  or  other  bloudveuel*.  thimgh  it  abounds 
outside  tliem  in  the  substance  of  the  villus  niid  in  the  lacteal  radicle. 

We  may  probably,  therefore,  infer  with  safety  ihol  all  or  at  lea.-<l  vi-rv 
nearly  all  tbe  fat  absorbed  from  the  intestine  takes  the  path  of  the  lactealiL 
Aa  to  the  deficit  mentioned  above,  thai  is  as  yet  vilhout  eiplnnation.  It 
may  be  that  in  some  way,  on  its  course,  in  tho  lymphatic  glands,  for  instance, 
tbe  fat  is  taken  away  from  the  chyle,  bidden  so  to  speak  somewhere  aw-ny 
from  both  chyle  and  blood ;  but  on  ibis  point  we  have  no  exact  iofonuation. 

%  308.  }VaUr  mid  nJU.  If.  iu  an  animal,  the  rate  of  flow  of  lymph  or 
ebylo  through  a  cnnula  place<l  in  tbe  thoracic  duct  be  watched,  and  water 
or,  lo  avoid  the  injiiriuUN  i-fTect  uf  simple  water  on  the  mucuuit  toeinbrnne, 
normal  (ullne  nolulion  Ik  then  injected  in  not  too  great  iiuantity  into  tbo 
intestine,  nt>  niarkcil  iucrt^aai!  iu  the  fiow  of  cliyle  thrnugo  the  cunula  is 
obeervcd.  Fnmi  thin  nu  nmy  infer  that  the  water  of  tlie  inlcutinal  conl«nla 
is  absorbed  nm  into  ih<-  la<-teat»  but  into  tbe  |>i)rtat  •ymeni.  If,  however,  a 
very  large  quntuliv  t>l'  l!i<;  nunual  Mtlitie  *i)liitiiin  he  injectcil  >n  ai'  to  distend 
the  iBttstine,  iIkii  tiiv  tlow  of  chyle  i?  increiwd  Iu  wmie  extent.  It  would 
appear,  thcn-forc,  that  while  under  normal  conditiooN  the  WHtcr  jawMS  from 


AUSORPTtON    KKOM    TIIK    Al.IMKSTAKY    CANAt., 


tiiM  ntuinlr  int<i  the  purtnl  blood,  eome  of  it  Difty  under  circutn- 

_  Hi  int'>  tlii>  lacteals. 

With  fvpird  to  lh<>  coureo  laktrn   hv  ordinary  aline  mattera  we  pnaacao  no 

]|isl    inlortnatioo.     When  special  s>lt#  eucK  as  potswium  iodide  ind 

,  CBsilr  ncogDlxed  by  appropriate  tml«,  are  iiilrotluoed  into  the  intes- 

.  (key  mir  be  apcedilv  delecleil  both  in  the  blood  and  iu  the  contents  of 

'  tho  thoracic  duct :  but  n  liciher.  in  »iich  oaset,  these  sails  find  their  war  into 

'  tb*  ihontcjc  duct  by  tbe  lacteal  radicle  of  the  villi,  or  pass  into  the  lyinpb 

[aifWim  at  tonw  later  pajl  of  iu  counte.  ue  do  not  know.     Nor  can  no  with 

nprd  to  Mich  a  salt  as  aodiuin  chloride,  state  absolutely  that  it  pedaca  mainly 

with  tlie  water  into  tbe  ]>Drtal  blood,  tlioiiKh  we  may  fairly  suppose  this  to 

bt  the  case. 

$  306.  Suynr.  Both  hl<MMl  and  chyle  contain,  nonnally,  a  certain  uuall 
tmotiat  of  auj^r:  and  careful  iot^uiries  «h(>w  that  tlie  percentage  of  sutfar 
b  chyle  and  tn  jj^eneral  blond  is  fairly  constant,  neither  Iwin;;  to  any  marked 
tilent  increswed  by  wta  amylaceous  wcalx:  on  ihe  mhi-r  hand,  a  meal  ood* 
Itiniiig  suftar  or  starvh  does  teaipurnrily  incrMiw  ihi-  <|iiiinttty  of  ougar  En 
tbe  portal  blood.  From  this  w«  nnir  ind^r  that  nurh  porlion^  of  thti  wugar 
_;  ff  Ine  tnttvlinal  conteiibn  as  arc  abmrlH'il  on  ^lugar  jituu  rxchiKirrly  by  the 

Cal  rein.  We  may,  howi-Vrr.  hen-  call  attcndnn  to  thi?  ililliculiitsi  attcnd- 
an  nrgumenl  of  tbi*  kind.  In  ihv  timt  plu<i-  the  tjuaiilitativc  dctrrmi- 
of  a  sfnall  amount  of^iuftiir  in  to  coniplvx  a  fluid  lui  blont)  i.-i  atlcndcd 
jfTMt  diffieultics'  anil  uncertainties.  In  the  Miond  phiw  a  vi-ry  largo 
quantity  of  bliHfd  t>  ol  anv  one  iixinK'nt  strcnminjf  through  the  capillaries  of 
Utt>  >JinM-ulary  <^nal;  and  wc  may  |x'rhn|B  speuk  of  the  quantiiy  which 
Baawa  ihroagh  them  during  tbe  whole  pcriuil  of  dig«»lion  lu  In-ing  cnormiHis. 
,  I1«M»  though  each  KM)  c.e.  in  pawing  thrnugh  the  capiUarics  might  take  up 
(quantity  of  sugar  »c>  uniutl  m  to  fall  almost  within  the  limits  of  errors  of 
ration.  yeC  tbe  whole  tjuantitv  absorbed  during  the  houra  of  digestion 
_  _  i  be  oonaiilerable ;  or  to  put  it  in  another  way,  an  error  of  observation, 
-maTOidable  with  our  present  meaiu  of  analrsio,  on  a  sample  of  blood  taken 
frtm  the  porta]  veoaels  might  lead  to  a  wholly  unwarranted  eonolusion  that 
majpu  WAS  or  was  not  l>einK  abs»rbed.  Making  every  allowance,  howerer, 
Ifrr  theM  diffii'ultiea,  thu  incrense  of  sugar  which  bus  been  obsen'ed  in  (he 
pnrtal  blood  during  diction  seems  too  great  bi  iiermit  of  any  otlier  exclu- 
sion than  that  sugar  it  really  abM>rl>ed  from  the  Hiimcntury  canal  by  the 
blondTcoaala. 

When,  howerer,  a  large  ((uaiitity  of  sugar  diMoIved  in  a  large  i^tiaiitlty  of 

water  b  prewnl  in  the  ini«*liae,  the  sugar  (n  the  cbyle  in  naid  to  be  tnorciwcd. 

In  such  a  case  the  eioMs  of  water,  as  stated  above,  |xun=i  into  tbe  lacteal*, 

I  CIkI  in  wi  doing  ap|ipiiri>  to  carry  some  <if  the  >tigar  wllh  it.  ' 

S  310.  Ptntriil;    The  dilficullics  atti^nctiu);  the  ■■x|H!ri  mental  determination 

of  tha  path  lakrn  by  protoids  are  greati'r  even  than  in  the  ca»c  nf  lugnr:  for 

tba  aiaot  iiuantiiativc  ostimation  of  [wptone  in  bli>oil  (and  wc  an;  asnimiog 

that  protcida  arv  mainly  nbsorlHtl  as  peptone)  is  a  laxk  of  the  gmlfst  dilii- 

evUj.  cMM  vomiiaml  with  which  that  of  celimnting  sugar  appears  almost 

MBjr.     Bearing  this  in  mind  we  msv  <tAte  that  all  ouerverv  ara  agncd  that 

I  peptMte  ia  absent  from  ehrle  or  at  (cast  that  its  nresenee  cannot  m  satis&c- 

\  lonly  proved.     On  Ihe  otiier  hand,  while  «onie  oneervcrs  have  succeeded  in 

Bnding  Peptone  in  (he  portal  blood  after  food,  but  not  during  fasting,  many 

bare  tailed  to  demonstrate  the  preMOn  of  peptone  in  the  blood  either  of  the 

portiil  vein  or  of  the  reesels  at  targe  even  after  a  meal   containing  large 

J  QUaDtUiea  of  protdds.    Of  coune,  us  we  ai^ued  in  speaking  of  the  absorp- 

l-non  of  ausar,  tbe  qnantity  of  peptone  pawing  into  the  portal  bloud  at  any 

i.nomeat  n^ht  be  small,  and  yet  a  oooaoerahle  cjuautily  might  so  piusduriitg 


■ 


tlie  biiun  of  digevlion.  We  may  »iipi>iHe,  iDorwver,  thut  ihnl  which 
pau  in  iniRii'iliBtel/  oonvorced.  {ws^ibly  by  some  ferment  Hciioii,  into  ofiv  or 
olher  of  ihtt  imiiinil  proteide  of  the  lilooi),  or  otlienviae  diepueed  of:  and, 
iiHleed,  i>0.|ili>nc  iiijcctcil  carefully  Had  elowly  into  a  voiu  disappMls  from  lb* 
blood,  thntt^h  little  or  even  none  pastes  out*  by  the  kidney.  Aim)  I  tit' view 
tb»t  iifpcnup  is  *o  cbaD|;;ed.  poKioly  in  the  very  act  of  absorption,  ia  siijv 
porli'd  not  only  by  the  8Uteni«Dt  Itmt  peplono  may  be  found  in  the  practi- 
cnlly  bloodlras  wall,  that  in.  inutouit  iiiembnioe.  of  the  iutesline  removed 
from  n  dcnd  miiiual  even  wbeu  it  appeitra  tn  bu  abteiit  from  the  bh>nd,  but 
idsu  4Uid  cepocially  br  the  follonint:  obserirutiun.  If  an  nrtilicial  circulatioD 
of  blood  be  kept  up  in  tbe  medenterii-  urli>ri<w  !<iij>plyi»i.'  a  loop  of  tnteatine 
lemoved  from  tbe  body,  the  I<H)p  may  b<?  kt-pt  nlivc  fur  kdiiiq  ootwiilerahle 
time.  DiiriuK  lliia  Hurvivul  a  conifiderablo  cjuimtiiy  of  {wpiuni;  plawd  in  the 
oavity  of  tbe  loop  wilt  dituitipnir,  i.  /-.,  will  be-  ub«»rlH-d,  but  cjinnot  bi-  rvoiv- 
ered  truai  Ihe  bluod  wbicli  i«  bdi))^  used  for  tbe  urtiiicinl  t-irinilntioa,  and 
which  e3>ai|H-.->  from  tbe  veins  idler  IravvrNng  the  intcstimtl  t:ai>illuin>.  The 
ditupiieitranee  is  not  due  to  iwiy  iiction  of  ihe  bUxjd  itself,  for  iMptonc  intro- 
duced into  tln!  blood  K-forc  it  i«  driven  through  the  mwcnicrie  nrleriiT*  in 
Lhe  exjieriincnt  mav  be  recovered  from  ibe  blood  ns  ll  csL-npea  from  tlic 
iDOOntvric  veins.  U  would  ttxm  as  if  the  peptone  were  ebnn^l  before  it 
actually  gel>  from  the  iiilcrior  of  the  intestine  into  the  interior  of  ihe 
cniHl  liiries. 

Bttt  llie  nrt;<iDient  that  the  abeeuee  of  peptone  from  the  blood  is  nii  pntuf 
tliat  the  itcploue  i§  not  absorbed  into  the  ulood  may  also  be  applieil  to  the 
cbyle.  and  thus  leaves  us  unable  to  draw  a  eoncluBioD  as  to  tbe  path  of  ths 
protdds.  The  fallowing  indirect  proof  that  peptone  does  not  pa«  into  the 
chyle  has  been  olfere'l,  but  it  too  ix  0)>eu  to  objeetiou.  We  ttliall  see  here- 
after that  the  absorption  of  pmteid  tuaterlitl  lead*  to  an  iiiereaf«  in  Ihe 
eliniinuiion  of  urea  by  the  kidneya.  So  marked  ia  thin  increase,  thai  uulea 
thvrv  br-  cIcHrly  some  other  c»ii«e»  at  work  leadine  to  lui  increase  of  urea, 
■uvh  ti:>  lever  tor  inrtniiw.  lui  incrwc  of  uren  in  uie  urine  following  upon 
the  admini^trnli'in  of  proleid  food  nniy  be  taken  iis  a  proof  that  tJie  orouid 
food  baa  beeil  digested  and  ali»orbc<l.  Now  if  in  a  dog  tho  thoracic  uuct  be 
auDoeflsflilly  ligatured  so  thni  the  chyle  cannot  paw  as  usual  into  the  blood. 
•nd  the  dog  be  fed  on  proteid  foo<I,  as  free  as  possible  from  fnt,  «a  as  not 
miDMesanfy  to  load  tlw  obslruoied  lacleals.  an  increase  in  the  uroa  of  tha 
UtilM  b  observed  aa  usual.  Obviously  in  such  a  cow  the  pmteid  food  t> 
abaorbed,  and  obviously  also  does  not  pass  into  the  blood  through  the 
Ihorado  duci  (tbe  success  of  the  lijjature  having  been  proved  by  post- 
mortem  examinations  But  the  evDeriment.  ihoniib  as  far  as  it  goes  sup- 
porting, <low  not  Tigi>r*iUHly  prove  llie  view  that  the  proteids  are  ahrarfaed 
Dv  the  i'«]>illanen  itf  tbe  aliiueutary  canal :  for  tbe  thoracic  duct  and  lym- 
phatics bi'low  tbe  Itxalure  vntn  fouiitl  laritety  distended,  and  lyionb  and 
cfaylo  npi>Mir  to  have  eicaped  front  the  veueU;  hence  it  b  passable  that 
•onM!  at  lca«t  of  the  jiroleidH  were  sbwirbcd  by  the  lacleaU  of  ihe  intCM- 
tine,  but  finding  ihvir  usual  {wtli  blocked  loaJe  tbdr  way  int4>  the  bloo<l 
aln»m. 

We  may,  therefore,  say  that  the  multa  of  cxpcriinont  while  they  do  not 
delinilely  prove,  give  some  supix^rt  to,  and  at  least  do  not  contra^lict,  the 
view  which  we  a  little  white  up*  put  forward  as  probable,  nanely,  that  of 
proteids,  ttanffornied  into  ditfusible  pc{>ton<^s,  {wss  into  the  bloodvewels  aiul 
not  into  the  Ucteals. 

Hut,  if  ibis  view  be  provisionnllv  accepted,  it  must  he  on  the  underttaixl- 
iug  lltat  it  is  pmbable  only;  and  il  may  l>e  that  protdd*  do  not  take  tltc 
same  |i«ths  and  are  not  nbeorbod  in  the  same  condition  in  all  animals.    TIm 


ARflOKrTION    KBOM    TIIK    ALIURNTABV    CAKAL.         428 

opntiDmbi  ju*i  rvlnk-d  wore  twrliirnicd  on  dogs,  thiU  is  ui  «iir  on  carnivoe- 

Mu  miinal*  iih<)m>  'nnlural)  toad  vonlaim  u  c(»ii»ilerat>le  i^uaniity  of  fal, 

■oJ  «h<*«  laclcsls  Riigbt,  itiercfoiv.  he  coaaidered  afl  preoccupied  iu  ibe 

*'wiir]4iiiu  rif  fal.     Tlie  fond  of  berbii'orit  un  the  other  baud  cniitniu*  a 

'i''alit«lv  ■mull  atitoutil  of  fat :  and  if  in  ibcac  animnU  all  the  proteids  nod 

nrbotitdrnln  are  nWirbed  hy  the  blood re«»elii,  then*  U  companuively  Ittlle 

''ft  fir  ill)-  In('ieii]»  to  do.     V«i  in  theee  aniniaU  the  liicieab  aod  lyrapbatio 

kT   **"  ''''^ *■'**!*"'■     '"  'I"*  villws  of  a  herbivoftiUB  guitien-iiig  or  rabbit, 

"j^^'ijeli  ihe  reticular  tinue  ia  vtry  icanty  a«  com|jared  niih  lUiil  prfewtil  in 

™*J  *illuji  of  a  dog,  ih«  liu-ieA)  caaiuber  ia  relatively  to  the  diaiui-ter  »f  the 

"''Ixa,  Dot  merely  aa  large  as  but  much  larger  tliau  in  ibe  dog.     It  in  dilfi> 

^'t  Iu  iu|>|>ose  l^ai  this  wide  chamher  is  ioteoded  solely  for  the  abtorpt>>ii) 

T^   the  relatively  small  amfiuoi  of  fnt  j>tL'»cnt  in  vegetable  foiK).    The  >jik'S- 

'*Xt  nbich  ne  are  ducuMing  i^  cleurly  at  prescut  to  ba  rtganlL-d  us  by  im> 

"•*■•!»  acUlwL 

Thf  MerJtaniim  of  Ahiorption. 

9  311.  Thr  nbtorplioM  oJ/uU,  \Ve  hare  now  to  conuder  the  manner  in 
^Vidi  ib«e  severnl  subaiances  pam  into  cither  the  lacteal  radicle  or  Ibe 
^'^ptllarv  bloodvessel.    It  will  be  cxmvenieut  to  begin  with  the  aboorption  of 

Wt-  hate  iWCD  raaon.  S  281,  lo  think  that  the  fats,  remaining  chiefly  a«j 
*a«uiral  fats,  are  eniulsiRed  in  the  intestine,  br  menus  of  the  )>il«  and  pMH| 
^muie  juice,  ihe  small  iiuautity  of  soaji  whicli  is  formed  pnilnhly  acrving  ' 
vitvply  ih«  piirjHve  of  fii<-ilitatitig  the  emuUifu-ntiun. 

TIi«  neutral  fnln  so  vmulnilied  pant  in  ilie  finrt  instance  Into  tite  budit*  at 

tbv  rulumnur  tvlU  of  thi-  villi  [Fig.  12-1].     It  has,  it  U  true,  bc«n  main- 

^shYfl  by  tvmo  that  they  piuu  briieren  the  cell*  and  not  inli>  them;  Ikii  the 

«vifk|ic»  i*  distiDdlT  ■gaiiii't  thU  view.     Thuc.t'lU  ma v  again  and  again  be 

Mvn  rri'Milird  nith  ml,  and  iho  cosci  in  which  the  lat  haa  Ikcii  seen  birtw^o 

the  (i')U  and  hot  in  iheni  iin-  due  to  ihv  extniMon  of  the  fat.  durin;;  the 

•hrinktnt;  of  the  villiix  in  the  cotinw  of  preparation,  from  the  cell'  into 

•psctx  ■•etwecn  lh<^' otlU.      In  llic  fmg,  in  which  there  are  no  villi,  and  in 

«bicb  ibo  folds  of  niucr'u*  nicTiibrane  eervin;,'  tho  purpurea  of  villi  do  n'>t  so 

mulily  tbriuk,  Ihe  presence  of  fat  globules  in  the  celtH  after  a  fatty  meal  can 

alwaya  be  easily  demonfltraied  by  osmic  acid  preparaiinna.    Since  no  auch 

ooilrcU'oos  of  (ui  globules  arc  seen  iu  the  cubical  cells  of  the  glands  of  Lte- 

brrkuhn  we  tufi-r  that  thnte  hiive  nothing  to  do  with  the  alaorption  of  fat. 

How  the  fat  eut«r«  into  the  substance  of  ihe  cell  we  do  not  know.  We 
■nay  prt^uiue  that  the  stnalcd  border  plays  some  part,  but  what  part  we  do 
not  know.  Thouffb,  as  nc  have  atKU,  the  rodj  making  up  the  border  ap(iear 
able  lo  more,  to  cnangv  their  form,  we  have  uii  evidence  ibat  the  fat  ia  in- 
tnidaced  into  tlM>  cell*  by  tm-an.t  of  any  movemenlfl  of  theae  rods.  We  may 
iimcine  ifaat  the  globulM  piun  intu  ibc  o^ll  MilKitnnce  by  help  in  some  way 
of  tnne  rials,  through  ammbuid  niovemenia  comparable  with  tlie  ingottve 
ffloveniinit*  of  the  IkhIv  of  nn  amrrha  ;  but  we  have  no  jHuitive  uvidencv  to 
aup|<»rt  Ihi*  view.  Wi-  Hiiid  4$24i)  tlutt  bile  proRioles  the  |>awagc  of  Alt 
ibrKucb  membraiif*.  jawuibly  by  in  luime  way  pmniotiug  n  chnvr  coatoct 
bctirnn  the  juirticlt-F  of  fiit  nnd  tlie  xiilititnncu  of  the  membrane :  but  evan 
if  bile  has  this  vlTet-l  on  the  stirfaee  of  tbi-  celln.  it«  iu.'liou  iu  this  reapoct  CW 
be  stibsidarv  oulr- 

Wilhia  llie  columnar  cell  the  fat  may  be  won,  both  in  uemic  acid  prepa- 
ntkfns,  and  in  fresb  livini:  cells,  to  l>e  ilti>|>(«ed  in  glnbnloi  of  various  sizes, 
•utue  Inrge  and  some  souill,  each  globule  placMl  in  a  spaoo  of  tiie  proto- 
plasmic cell  subatanoe.    It  doea  not  fotlow  that  the  fat  notually  ent««d  the 


A.  tncnui  or  ms  Viuu*  or  a  Ktt  Kivr.Kii  hohitio  r*T-xBW«ra<Mi. 
9i,  tpllkelliuii :  ifr,  itrliital  border  1  e.  Iyin|.li  relln  :  f-.  lyniph-cclliln  OicopMwtMni ; 

'.  Mulnl  litplral  lonulnliigilliliitniimlnii  l<tni[>li-«>rpiuolMi 

B.  Hooont  UcxBKU'i  or  FBO»*i  iNmnDti  t>tiii[!in  rAt-Atmotrnttx. 

t/r.  tfUMUaai :  ifr,  «iH>Wd  bonUr;  i^  lyui|il>-air)iuinli>t ;  t,  UoWkl.] 

From  l.li«  cohniinar  mII  the  fat  [latMS  iuto  ih«  anaoea  of  tlie  rcticular 
Umig  of  Uio  villuH.  U  hiiH,  it  is  true,  been  mntendeu  that  it  paiuui  aioog 
tlio  subAance  uf  tliir  bunt  of  the  [«ti<^ululu ;  but  in  uarcfiiUy  i>r«par«cl  oaiaic 
acid  apecSnicnv  of  a  villus  in  actire  iligevtion  uf  fatly  foud,  the  fat  may  be 
distincll}'  recoraixod  m  InrKcly  lillinif  up.  !ttill  tii  the  form  of  globiilca  of 
varioiiit  rnux,  the  >jiac<w  in  flip  m«hw"  of  the  n'tioiiiiim  whidh  are  not  uocu- 
pieil  by  the  Iciicocyt«  i>r  iitliral  iiumlcring  ccti»-  Wc  have  aeoD  (S  MI  J 
that  the  biKo  of  the  columnnr  iiill.i,  ihniuKh  the  gap«  in  the  baMixieoi  mctn- 
tmuie,  directly  nbiit  upon  the  liitiyrinth  »1  Riinom  ;  imd  the  fat  onee  nnt  of 
tin  base  of  the  cell  id  free  in  the  xpaeo  of  the  labyrinth.  How  it  iasuee 
from  tjie  cell  we  do  doI  esaclly  know ;  pomibly  by  n  proceaa  analogous  to 
t]i«  eser«tton  of  solid  matters  by  an  aintcbii. 

Froni  llie  Inbynnth  of  cpacca  of  (he  rclieuliim  of  the  rilluE  the  fat  pasMa 
into  ibe  cavity  of  the  lacteal  radicle:  and  il  is  worthy  of  note  thai  io  the 
IMMBge  it  undergoee  a  e)ian);e,  In  the  interior  of  the  inteotine,  iu  the  aub- 
■tanee  of  the  oolnmnar  cell,  and  apparently  in  the  labyrinth  uf  the  reticu- 
lum it  is  aiiuplv  einuUiflt^d  fat  consisting  of  globules  small  nnil  large ;  williio 
the  lacteal  radicle  it  eonHistfi  jkartly  of  the  aame  ea«ly  recognized  globules 
but  part3y  of  the  extremely  divided  "molecular  basts"  ($300);  it  is  now 
DO  lonf^  enmUiSed  fat  but  chyle.  How  and  by  what  means  thw  extremely 
miiiut«  divijioii  «f  the  globular  fat  intu  the  "  molecular  basiit "  lake*  place 


ABSuBJ-TION    KKOM    TIIK    ALIMENTARY    CANAL. 


426 


■  •tdoBM  know  :  nttr  do  «r«  ktiun  the  «Xficl  manner  iii  wliieb  the  fat  jmumx 

■  frw  tlw  Bpmces  of  ibe  reiiculum  into  ilie  interior  of  tbo  radicle.  If  th« 
V  4m  cf  niiiiouH  epidieliiHi)  platM  wbieh  fi)rnu  tbe  aole  wall  of  ibo  cbamlicr 
^L  fcdBcooliiiu'Mi*.  prMenliciK  here  aod  there  ini|B  Iwtween  tbt-  pUten.  the  pM* 
^^b|ppitseu[B  11(1  ilitliruUy  in  il««lf,  but  itiiCH  mine  the  iliffii'iiltv  why  there  is 
^^Bbgnftt  •  (lilfi-r«iioe  iM-lween  the  chyle  iiiiii<le  the  chnnibcr  hd'I  iht^  fat  oiit- 
W     Ak     On  the  other  hand,  if  as  ohaerTaliona  aeem  to  nlio^'  the  linitii;  in  ques- 

■  Ml  b  actually  coiiiinutNia,  the  fill  must  pan  into  the  hict«al  radiole  either 
I  ^<Ki|>b  lb«  subHtanoe  of  tlu-  pliiles  or  through  tlx'  jnnrtion  line*  of  cement. 
I  A>ch  a  ptuaa^  prrvenudiHiotiltiiv:  hut  u<  the  mmc  titnu  we  can  oouceive 
I  '^t  ill  the  itrusglca  of  >uch  a  [iiuutu^-  nnniv  of  thi-  hil  might  be  converted 
'     i***'  the  tuoleculnr  iMuin. 

W'c  may  Imt^  nrrha|M  reninrk  that  the  (»Dt«iit»  of  thv  lacteal  radicle 

^>*iM  IMM  eiclu«tvplr  of  1st.  hut  of  fat  accooiiHinied  by  thi?  pntteid  and 

■'htti  nbauon*  which  jro  to  make  u[>  the  chyle.     Proteid  and  olhoir  sub- 

••■^Jow  hiwidM  fin  an.'  also  pmciit  in  tde  lymph  which  owunic*  in  part  the 

"^yrintb  of  lh«-  lM«ly  of  the  villus,  and   arc  derived,  like  ihf  lymph  el*e- 

'f'^ow.  fmm  the  bloo.|  of  ndjacciit  capillaries:  at  Icswl.  they  are  in  part  si> 

•^]»"iv<d.  th-High  it  may  be  not  wholly,  for  aa  we  have  jiigl  aeen  iho  Jiaiwage 

f*"    pmirid  niutrrial  from  tbo  interline  into  (he  aubstanoe  of  the  villu*  paal 

"^^  capillarin  though  not  prove),  must  still  be  comidered  as  ponible. 

^«  haw  Boen  (§  'i6'i)  that  the  spaeea  of  tbo  reticulum  of  the  villus  are 
^^kr»  or  lev  occupied  by  wandenng  cells  of  which  wo  spoke  under  llui 
S^MiM>I  lertn  of  leucocytes.  These  do  not  atl  present  the  same  appenranon 
^*kd  MoM  probably  are  not  all  of  the  same  kind.  A  number  of  Ihem 
''^y  br  distmi^uisbed  by  the  fact  (hat  the  cell-body  is  loaded  with  discrete 
C^^nulo  which  stain  readily  and  deeply  with  certain  aniline  dyeB.and  which 
**tougli  Dot  of  a  fatty  nature  turn  black  with  oamic  acid. 

Some  of  theae  leuctioytea  waiider  nut  ouly  Ihmugh  the  labyrinth  of  the 
*^ttrtiluni  but  pa»  into  the  epithelium  between  ihe  oelhi.  and  may  project 
IhroeMMM  ini').  or  even  make  their  way  eventually  inin  the  interior  of  the 
KBIaalloe:  or  followini^  tlie  n-ver»e  eounte  niny  wamler  fmm  lietween  the 
^ptlhaBum  oelk  into  the  ttody  of  the  villus  ;  iinme  of  them,  moreover,  un- 
Qoabtadly  eontain  fat.     Hrnon  thi^  vit^w  hai>  W>n  ninected  tliat  thcae  leuco- 
oyMa  arp  im[>ortjiiit  agent*,  indeed  the  chief  agenia  in  the  abtorplion  of  fat. 
Xi  bu  Itrvu  nuppiiMrd  that  they,  rcii-iving  the  globuW  of  fat  into  tliL'tr  cell 
■nbataace.  in  fiict  eating  thv'fnt  exa>'tly  nfifr  the  manner  nf  iin  ninteba, 
«itlNir  while  pnjeoting  beiwcen  the  cnlumnitr  n-U*,  in  «  hich  caiw  they  c«rry 
tbrir  bordfn  of  fat  throiieh  l.h'>  ppithdiiim  into  the  villii*.  or  whili-  w»ud«r- 
■ng  io   the  labyrinth  of  tat-  villui',  Ix'-iir  it  awny  boililv  into  the  lymphatic 
•jitMli.     lint  thi  number  of  Imicocytos  rvally  cunt.niniii};  any  nnprrHable 
quantdy  uf  fat  is  too  smalt  to  account  for  the  nmouiil  of  (at  nhfiorlml ;  mdco 
MM  we  ju*t  nointed  out  in  a  certain  kin^l  of  thrsc  cells,  and  thix  kind  ii  ofli^ 
vrrr  abundant,  the  granules  in  the  cell  subslUDoe  which  stain  with  uamic 
■nd  are  not  fat.    Nor  is  the  abundance  of  leucocytes  in  Ihe  mucoaa  mem- 
brane during  Ihe  period  of  digeetion  a  sure  proof  that  they  are  conecmed 
Is  abaorptioD,  but  rather  an  indication  only  that  active  chaDgea  of  aoine 
kitKl  arc  going  on,  since  after  the  administration  of  a  saline  such  as  magna- 
tiuni  sulphate,  which  producee  eHiKts  the  very  reveree  of  absorption,  tnSM 
leucocytea  are  preeent  in  unusual  numbers.     Moreover,  under  some  drcum* 
fltancea,  aa  in  toe  villi  of  a  new-born  puppy  after  a  meal  of  milk,  thev  are 
ahaent  even  when  digestion  of  fat  i<  noidly  gislag  on  and  the  Uuiteals  are  Ailing 
wilb  fat.     In  fact,  what  we  stated  aoDTe  ooitc«ming  the  preaenoe  of  fat  in 
the  bodiea  of  the  coliimuar  celle  shows  that  1euci>cyt4«  can  have  little  to  do 
ill  timnaferring  fat  tnm  the  interior  of  the  iuteatinu  iutu  the  body  of  villus; 


rilK    TISSfE 


Rml  then!  urv  iio  m]ui[iinle  rcjifnii'  for  iitlriliiiting  in  lliem  imjr  mA 
ill   llu-  intadfvii-iKri;  <if  fiit   fri>ni    ttio   Ixiily  <>(  live  viltii*    into  ihe  1( 
c  bum  til- r. 

^  312.  Tlic  Inctciil  ctiunitior  ojHtnK  iil  ibi.-  base  uT  the  vitlii*  inui  th«  r«lre(l 
lj-ni|>hii(io  viwjcis  lying  Iwlow.  nnil  in  iht'w:  the  lliiw  nf  Ivinpb   .oliyl*l  is 
In-inj:  ]ii-i)mol«l  by  llic  vorioim  ciiiiMv  ^cintlcMl  in  S  :i01.     'flic  prewun;,  for 
iii»tiinco.  I'xerteii   liy  the  niTisliillic  contrnctions  nf  ibo  inuisiini.-   belpt  to 
vmpty  the  lyinplmlic  vt^Hvl  ioti)  which  «  Inclcnl  chamber  ojhim  imd  w  pro- 
mote tho  cmplTing  of  the  IkcIit.     In  mltlition  to  this  the  )>lniii  riukuIv 
fibrM  of  the  viliiia  Biipcily  ii  ^jK'dnl  niuKiilur  pump  for  the  «ni|>lyine  iidiI 
filling  of  the  lacicnl  cbiiniber.     These  fibm  atid  email  l>iincll<»  of   ubrt*. 
though  niitning  in  various  directions  ( §  ^ti^i)  uod  rarring  in  nunilwr  luld 
Hrmngcmenl  in  diflerODi  animals,  take  OD  the  whnle  a  lungitiidimil  dinvlioD 
pantllcl  lo  (be  loiif;  axis  of  the  villus.     It  has  bcea  supposed  thftt  in  odd- 
tmcliog  and  shnrleuiug  the  villus  they  coinprees  the  laclcul  and  thus  omptjr 
it,  and  that  when  they  relax  and  the  villii»  doaj;atea  a^ain,  the  emptiM 
cbfliiiber  fills  ouce  more.     But  a  diRl-reTji  interpretation  of  their  action  bw 
been  oltered  somewhat  u#  fullowa.     When  the  muHcular  fibres  contract  tk^H 
shorten  the  villus,     in  tbii&  tKH-'Oiuin),'  »hcirter  the  boily  of  the  villus  b«codH 
proportionately  bromler,  since  nrobably  no  uixiai  ekauKe  of  bulk  in  I  ho 
reticulum  lukes  place;  in  tbia  Lruailfiiin^;  the  part  to  ^ive  iiay  vrill  be  the 
lacieiil  ehiimlier,  mhich  thim  lieconu-*  brouder  and  tarKcr.     When  the  fni»»- 
culitr  fibn-tf  relax,  the  n-ticulitni,  the  )i»r<  of  w  hicb  have  been  put  on  the 
streii'h  in  ii  ]iit<-r»l  ilirv«ioii,  bv  daiilie  raiclion  briiii^  back  ihe  villus  to  ila 
fiiniier  li-njij^th,  and  tbe  lacteal  oluinilier  ulongiitcs  iiinl  niirrows.     Un  ihb 
view  the  niuvcular  contraction  ex|iiiiidii  anil  *<>  liDtt,  nbile  tlie  reluxatioQ 
twrmu'*  and  w  <:niplie»  the  luclcjil  rhanibcr.    Which  ever  view  we  adopt,  we 
may  at  IviiMt  conclude  that  contracti<>ni>  and  telaxationit  of  the  musculnr 
fibrtn  in  wime  wav  or  other  nllornnlclv  lill  iiiid  eniptv  ihi'  lacteal  chamber, 
and  ill  iill  probability,  utall  cvoul:<  during  dieeaiion.rliytlmiical  cxHitimclJon 
III'  these  tibrce  are  cimtinually  ffowa  on.      \Vben  the  villus  is  sliortened  bv 
tbe  contraction  of  tbe  muscular  fibres,  the  ooluninar  cells  are  oompnmo, 
becoming  longer  and  narrower;    when  the  muscular  fibm  relax  anil  the 
villus  elongates,  the  columnar  cells  return  tit  their  previous  form.     Tbt 
Bltemaiin^  chnngeit  of  form  to  which  the  columnar  celU  arc  thus  enbjei-twl, 
and  the  alteruuttiig  elian{(es  of  pressure  takiu^'  place  io  tbe  reticulum,  may 
alsf)  serve  t»  promote  tbe  passage  uf  nuitcrial  through  the  one  and  lliroiigli 
tbe  I  Ft  her. 

$  313.  The  abtorfitiiin  <if  tli^'anbU  mh*l'>urM  and  of  tiviler.  On  the  pro- 
Vi8ii>nal  aaauiuptiuu  which  we  have  made  thai  tbe  prateids  ore  coiivcrtcal 
into  peptone,  we  may  cuiiiider,  for  tin-  pn.v4'ni  at  all  events,  ]ic|>ti>iie,  sii):ar, 
tad  Miuble  salts  as  together  forming  a  cIiim  ■liiilinjiiiiabed  fVoiu  fal»  by  tlwir 
beiuK  dilTuaible,  some  more  .-u)  than  othcn.  Atul  we  have  made  the  furtber 
proviatonid  aMumpllon  that  ihcac  pim  lutu  tbe  btoodvc*»cU  and  not  into  the 
toetealM. 

The  netnork  of  oapillarr  bloodvcmels  is  spread,  as  «c  hare  wen  ($  263), 
immenlbitvly  liciicatli  the  bawmviit  membrane,  and  all  the  nuilerial  which 
enter*  the  lactriil  vhnnibcr  bu«  to  run  the  gauntlet  of  the  luusbes  of  thi« 
network.  Ihirin^  iligmion  tbe  capillaries  of  the  intmiiic  are  filled  and 
di«tcndcd,  to  that  at  ii  time  when  absori)[ion  is  taking  place  these  imshea 
Ijctwcrn  the  capillaries  ate  unusually  narrow.  From  iho  interior  of  these 
capillaries,  here  il*  cl»cwhcre,  transudation  ii  taking  place ;  thctc  capillaries 
supply  tlie  lymph  irhich  helps  lo  till  ui>  the  labyrinth  of  the  reticiiluiu  and 
the  Incieal  chamber.  Hut  to  a  mitcli  jnvalcr  extent  than  elscnhcrc  <cf. 
$  ^4>.'t)  thi»  current  of  transudation  from  within  the  capillary  to  without  i« 


ABSORl'TlOX    rHOV    THB    Al.lM£NTARr   OAKAt. 


427 


Nc<r<>iiipiuii«d  by  b  reverse  rurreol  froio  without  to  wiihiu.  Tli«  diSVisible 
suIietflnoM  in  <)Uwtion  poM  from  the  inlesitne  throujth  the  layer  of  epiiheliiim 
oelb,  tlirou;;h  ilie  aii^nuated  re(i<:ular  lymjilixiHice  betneen  the  Itasemetit 
membrane  aD()  the  i-apillary  wall,  and  tbruugli  tlie  uiitillarv  wall  into  llie 
blood  current.  Their  {mwaije  cuiiuittUi  of  two  otjt^;  tlial  l^muKb  the  epi- 
ibelluni  cella  (Voni  the  inleatini'  to  thi>  lymph-sjiaoo,  and  tJiat  tVom  the  lymiib- 
s]Miee  into  the  bloudvcsaels.  Thenc  two  Rtagm  may  beenpeeled  to  diliW, 
seeiuiK  tliat  the  titracttireit  mmciTmitl  arv  dilTuniil ;  but  »<•  nmv  nt  fint  nm- 
uder  tbeni  oa  one,  bikI  upvak  of  thi;  piMutge  from  tli<-  inttMiov  inio  the  bliHiil 
aa  a  dingle  ovciit. 

In  Mpeaking  <>f  ihnc  «ulwliinct«  as  liift'iinihlf,  in  an;  uting  the  term  in 
referenoe  I^i  thi*  well-known  piiwngc  of  such  xiilwlnnoes  through  tbin  mran- 
braii««or  pon)u«  partiiloiut.  When  a  strung  solution  of  sugar  or  of  common 
mII  i*  wniinikd  by  a  thin  nieiubrame  fvfjgelable  parchment,  dead  urinary 
bladder,  <l<!a<l  intestine,  etc.)  fn?m  a  weak  salution  of  ftiigar  or  of  sidl,  the 
iUKiir  or  mU  p«s»es  with  a  certain  rafHdicy  Irom  the  stronger  to  th«  weaker 
■altllion,  and  naicr  passes  tVuni  tbe  wenker  solution  to  the  stronger;  if,  to 
bwin  with,  simple  water  be  aubfltitule<l  for  the  weaker  solution,  thi?  eHbct  is 
■1  nrsi  still  more  striking;.  I'eplone  peaaea  in  tbe  same  manner,  but.  as  we 
hare  seen,  much  more  slonly.  The  procees  is  spoken  of  as  a  jthysinil  one, 
since  it  is  not  sct-ompnuied  necessarily  by  any  chemical  chan^  in  the  dif- 
fiising  substauce,  nor  ia  iliere  any  neccaMnr  change  in  the  njemhnine  or 
partition.  The  rate  at  which  a  luostanve  A\ffuxii,  and  the  total  amount  of 
(litt'iieion  which  can  take  |flaoe,  are  deleniiincil  l>y  certain  (|i]alitieti  of  the 
Bubetaiice  (wliicli  ire  mav  call  hhvsical,  lliouuh  they  de)iend  on  the  chemical 
nature  of  the  Bijhsiancc^  in  relation  to  certain  i|iiiiliiic:i  of  the  membrane; 
thus  tnn  f&hi  may  >titriiM!  thmugh  the  mun'  membrane  at  dilferenl  ratea, 
with  ditfvreiit  rattan  in  l)i<-  iui«iiciat«<I  ciirtruc  cf  wnlfr.  thu  o«m<itic  current, 
at)  it  is  catted,  I'nim  llic  weaker  lo  the  :>tn>ti)^-r  solution  ;  and  the  -ami-  nub- 
ataiice  may  {ia.-ii  at  dilli-rcnt  rel*»  through  d^iHcivut  nxtmbmncii.  Bv  a  num* 
Iter  of  obaervationx,  in  which  various  subftancw  in  S'ltuliim  nndi  acvenU 
known  ineinhmneo  or  partitions  have  bocn  employed,  a  ct-rttiiii  number  of 
"  Ibw»  of  dtlTuHon  "  have  been  f«tiihli«lieil. 

Now  if  by  t)i<>  statement  that  dilfitsible  substances  pan  by  difTusion  into 
ibe  hloodTapillariee  of  the  itiiestine,  we  are  led  to  expect  that  the  piuwag<.> 
takes  place  exactly  ticcortliug  to  the  laws  celabllshed  by  obscrvntions  on 
ordiiuiry  aHMnbrtuMa,  wc  should  be  led  into  ermr ;  for  the  disappearance  of 
these  substanoea  from  the  interior  of  the  intestine  doee  not  take  place  accord- 
log  to  the  laws  which  regulate  their  disappearance  from  one  side  of  an 
orainary  diffusion  eeptum.  This  can  be  aacertained  by  introducing  solutions 
of  tbe  substnncee,  of  various  ^trenglb.  into  a  loop  of  intestine,  isolaieil  in 
tb»  living  animal  by  the  raelJtod  de«cril>ed  in  i  '2oO,  and  waichiii;;  their 
dieap|>earaut'e  hy  anatyflin  of  the  oontenl»  uf  ilic  loop.  >'u  very  lar^-e  num- 
ber of  esperimeiitu  hiive  l>een  maite  in  ihif  way,  hut  «uch  an  have  been  made 
all  show  tliv  differenoe  on  which  we  ttrv  dwelling.  For  ioKlancc,  acMlium 
sulphntv  )HUBe»  ihrtxigb  an  onJiuary  difliiMim  M-fitum  with  n  rapidity  rather 
fCreater  than  ibat  of  dextrme,  whereas  dextniM!  dioappcjtni  from  the  intestine 
diatinctly  more  rapidly  than  Molium  »ilphate;  |<ept»ne  which  dilTuititt  vi^ry 
•liiwly,  indecil,  through  an  ontinarv  difPiuiion  septum  diMippcan  rapi<lly 
(lliiMigb  not  tH>  rapidly  hi  lii'xtnnvj  from  the  inlc;>tinr ;  and  when  the  delaila 
of  tlitr  dii>ap|>ni ranee  from  the  inteeline  of  weak  solutions  of  two  nails  which 
(lillUw  ihriiugli  an  onliniiry  mendiranc  at  dil)!.Tent  rates,  whicli  bavu,  a»  it  ijt 
aniil,  liillVn'nt  <«molic  enuivalentf ,  are  stiidietl.  these  details  arc  quite  diflcreiit 
from  those  of  ttnlinary  dill'iision.     Tits  more  tbe  matter  is  studied,  the  mors 


428 


TUC    TISSUES    AND    MKCIIANISMS   Of    IMOESTIOX. 


tlwid^ly  npparent  becnmca  the  diHerence  betuc^ti  orduiar^  dilTiJiinn  and 
tlip  nlMorptioii  of  ditTuHible  substaoces  from  the  iiiteslino. 

Moreover,  in  such  exj>erimeiiL!  od  an  iaolHled  loup  of  iniettine.  the  di»- 
ap[>eaniiR'e  of  maleriul  rnini  the  iiiteetine  in  iii.'ct>m[>«niei)  by  ilie  ii))|>eiiriiaoe 
of  inatenni  in  the  iiiteeliue.  immely.  proieid  and  other  fiu)>alsii(.-ee ;  these  >K 
derived  from  the  blood.  And  the  f(uestiim  arises.  If  w  allow  oiiraelvee  to 
regftrd  the  passage  of  nmteriai  from  the  iut«rior  of  tb«  inteeiioe  inm  ih« 
blooil  aa  carried  out  by  onlioary  [lifTiiAioii,  why  we  should  not  reicard  the 
pAsag  e  of  material  from  the  bloixJ  iiiiu  the  interior  of  Ibe  iutntine  ss  beiog 
also  carrie«l  out  by  means  of  dilTusion?  Bui  such  a  panoKe  w«  sneak  of 
el.Hevrhere  us  a  "  secretion  ;"  and  everylhiiijt  which  we  have  hitherto  learned 
baa  led  un  tn  the  concluitioii  that  HecruI.Ion  is  a  diRerenl  ami  mneh  more 
complex  thing  IVom  mero  diH'uMoii.  Kvmi  adinittini^'  that  the  snc«u>  eo> 
teri«us  in  of  -lubordinale  importuncc  in  carrying  out  dlgeMlve  chatiKCS,  we 
cannot  doubt  that  the  glands  of  I.iflM-rkiihn  wecrete,  and  mav  with  •mue 
neoMO  auppoM  that  the  uolumnnr  im^IU  of  the  villi  do  m  aW  Henoe  sren 
if  we  ainimo  the  esixtcnt'c  of  nn  ordiiiiiry  ditTunion  current  from  the  blood 
Into  tho  int«vtin<',  aci^omnnnying  and  compK^racntary  to  nn  ordinary  dilfitrioo 
current  from  thi'  intcvltnc  into  the  blood,  wo  urr  comiiclird  In  admit  that 
with  this  llicn>  coi^xi«t«,  at  times  at  all  cvcnl*  and  in  varying  int'-n^ily.  a 
current  of  u  iliffcrenl  and  more  complex  nature,  n  current  which  !•  tbe 
result  of^M-rt't'iry  activity.  Atid  r»iilt«  which  at  fir»t  fight  seem  cxplicabl* 
by  the  former  niny,  ntYcr  all.  be  due  to  the  latter.  Thus  the  Sow  of  water 
into  the  inti^<line.  with  tho  subsequent  production  of  a  watery  stool,  which 
follows  upon  llic  introduction  into  the  alimentary  canal  of  a  concentrated 
solution  of  magnesium  or  eodium  sulphate,  may  at  first  eight  seem  lo  be 
simpiv  the  osmotic  current  passing  from  the  weaker  solution  of  tlie  salt, 
namely,  the  blood,  to  the  stronger  solution  of  the  salt,  namely,  the  inteatittal 
contents.  But  the  ditlerenoe  between  these  effects  of  a  dose  of  magnesium 
nilphate  aiid  thiMe  of  a  correaponding  dose  of  sodium  chloride  are  much 
greater  that)  can  Im'  accounted  ror  by  the  dilTuMon  phenomena,  by  the  dilTer- 
mg  immoiic  LM|uivali!iit«  of  the  two  ■ubscatictft;  and  the  wore  the  matter  is 
Mtiidicd  ihn  more  reastm  linvc  we  to  believe  that  the  Bow  of  water  produi^ 
by  tlic  former  is  to  a  large  extent  the  result  of  nuddenly  increased  swjvlory 
activity.  So  nliu>  the  fact  thai  tho  contenU  of  the  small  intestine  thrunghoul 
il«  length  retain  the  name  nmnunl  of  wntcr  relatively  to  the  mlidii,  that  in  to 
way.  maintain  tho  same  or  iie-arly  the  mrno  fluidity,  whcn»  in  the  large  in- 
tettine  the  water  rctativelv  dimiDi»hes  until  at  last  the  fvcc»  become  firm 
and  even  dry.  cannot  be  wEioUy  explained  without  calling  into  our  aid  varia- 
tions in  active  focretion  m  distinguished  from  mere  physical  diiru>>i'>n.  .\Rd 
in  tho  case  of  a  purgative,  such  as  croton  oil,  producing  a  watcrv  «tool.  when 
only  a  minimal,  we  might  almost  say  an  in6niteeimal  amount  olMta  own  sub- 
Stanco  can  at  aiiy  one  time  he  present  in  the  intestinal  walls,  the  result  is 
obviously  due  bi  active  secretion. 

If,  however,  we  are  thus  driven  to  the  concliuion  that  the  passage  from 
the  blood  into  the  intestine  is  a  mflnife^tstion  of  secretory  activity  in  which 
epithelium  cells  play  a  imrt,  gradually  becoming  little  by  little  more  intel- 
ligible to  us,  why  Simula  we  tiot  admit  that  the  passage  from  the  intestine  to 
the  bloiMl,  which  ae  we  have  seen  dues  not  accord  in  its  phenomena  with 
known  proccMts  of  onlitiary  dilTusiou.  is  aluu  brought  about  by  the  activity 
of  cells;  is  In  hot  ■  kind  of  inverle<l  secretion,  and  hence  tike  ordinary  secre- 
tion prewota  |miblems  which  cannot  be  solved  by  any  off-band  references  to 
known  phyricttl  pTooCMM?  Indeed  tbis  U  the  concluition  toward  which 
observation  and  experiment  seem  to  be  ntwidily  leading  us.  Were  the 
alveolus  of  a  Hilivary  gland  habiiiinlly  tilled  with  a  fluid  of  mixed  and 


FTltiN    rnoJI    THE    AhlMBXTAKY    CANAL. 


429 


I 


rsrinl  lutura  like  Ihe  cootenu  of  tke  aliiueoiarv  caoa),  mi;  dboulil  prubxMy 
in  nur  *4U()y  of  ilt«  f^lniid  Gmi  imnielv«  ciiii)|ii-llr<J  tu  «|i(.-uk  »f  u  ilouble  our- 
rrtit  «■  cxbiiog  ID  ttie  gluud.  uf  a  curreiil  fmiii  (he  oelln  to  ihe  lum«n  of  the 
Klreolua,  and  of  k  ciirrmu  fmui  lite  luineu  lo  tJi«  ck\U.  And  tJI  nloiifi:  lliv 
iltlMCiilt  both  Uiv  columnar  niid  ciibimi  cells,  wliicli  I'vtiryn'hcre  In^ir  tlw 
Mttka  a£  bvlog  "  active  "  cell:),  m*v  |i«rlin)!ii  be  n>ciirili;d  ni>  eiiffiiged  in  n 
lika  donblo  ftioction.  Ovrr  the  villi  (hv  rts^ptive  tunrtioii,  in  tli<'  (.dniiilK  of 
LWbsHtuhn  lh«  rj«ctiv«  ftinclion  is  [>rrdonnaivut ;  but  lu  we  linve  vuggiwtvd, 
i  W6|  in  tbs  zlmutla  rrcvjAion  probably  ia  tint  ntinlly  idmciic,  mid  uc  may 
haagiiM  ibal  in  Ui«  villi  aomt  amount  i>f  ejvcti»ti  (ijiiitc  njnirt  fmni  the 
acdon  of  the  gnblat  0«lb)  idat  t^o  placv. 

If  this  view  lieaocqtted,  ir  we  admit  Ihiil  the  ciitran«>  uf  (lighted  food 
doM  BM  lalce  olaoe  by  ordinary  dilfunoB.  the  <)u«tion  nmy  U-  niked  why  are 
tbv  dqfMlire  cbanjm  dircctiMJ  toward  Jnoraiaod  difiuaibiliiy,  why  are  protci<la 
aoBTCrted  into  diflii»ible  peptones,  nnd  why  is  starch  converted  inta  sugar  T 
BMnaae  iboui^h  the  cell  is  not  nn  apparnliis  for  diflbsion,  diffusion  is  an 
iiMlMiiMiiin  uf  which  the  cetl  make*  use.  When  we  say  that  peptone  does 
■04  mtei  tbe  blood  by  ordinary  diiTusion  we  do  not  mean  that  diHiision  has 
aotfaloK  (o  do  with  the  matter.  The  nctivilv  of  a  living  cell  is  an  activity 
bQili  op  upon  and  timkint;  u»e  of  various  cbeiuical  and  physical  prooewea ; 
ia  it  thr  proceaicii  of  urdioary  difl'uuon  play  their  part  as  do  tlie  proceaaes 
of  ctnlioary  chemical  decoupoeitiou ;  but  the  cell  uacii  and  inodiHea  them  for 
ila  <twn  roda.  If,  aa  we  have  every  reason  t>>  lielievt^.  Ihe  eell  of  a  villus 
puBV  the  »ujrtr  iinchauKed  from  the  intestine  into  the  blu»d  (.-iipillary.  it 
nalm  uw  uf  difl'usiuu  l<>  elleot  that  paaaage ;  and  if  it  doea  chaii;je  the  prt>- 
UM  iniii  ^'mt-ihin^  eU«  before  il  paaaea  it  uu,  it  receiver  it  into  itself  in  tJiv 
8m  iiiatniic*  bv  li«lp  of  diffueiiiin.  When  ne  auy  that  subataDees  do  not 
cnirr  thv  blood  "by  oriliunn-  dillunioo  we  mean  that  tbe  ditliiMOD  which  taken 
place  in  m  living  cdl  i«  iu>RK'tliiiig  m  dittt-re^it  in  ihc  results  from  ordinary 
difltaMOB  tbrough  a  dead  mcnibntnii  that  it  is  undi-sirable  to  »pcak  <>f  it  by 
Uw  MUBe  nani«.  In  ordinary  diHiision  ihc  n'sulls  depend  on  tbe  rcliUiun  of 
ibc  noleculea  of  the  diffusing  substance  to  the  minute  por««  or  canals  or 
•pwa  in  the  diffusion  Mptnm.  Tlicso  t-nnals  or  spaces  are  constant  in  an 
ordtnarr  septum  :  but  a  Kim  of  a  living  cell  may  be  conceived  of  asa  diUlision 
septum  the  pores  of  which  nn  continually  varying,  and  moreover  lu  closing 
up  or  openin)*  out  at  the  touch  of  this  or  that  substsjice ;  hence  the  passage 
01  maierial  through  tbe  pores  of  a  living  cell  lakes  place  according  to  laws 
qviie  dlflereni  from  those  of  ordinarv-  tlinuifion. 

{  SI4.  The  whole  act  of  the  absorption  of  subsloncw  with  which  we  are 
dMling  ountisiB.  aa  we  have  said,  of  two  parts ;  the  pa/wage  IVoin  the  interior 
of  tbe  inlctune  lhrou|*h  tbe  ejiilheliuin  cell  into  ihe  lynipb'Spnoes  or  reticulum 
af  the  villus,  and  the  paiBiij-e  llience  through  the  capillary  wall  into  the  blocKt- 
■dsUB,  In  tbe  experimeuis  refernd  tu  above,  it  has  not  been  possible  to 
distiMuisb  between  these  two  stages  of  the  whole  procew ;  in  each  case  we 
ban  nail  to  ualte  use  of  the  terms  "  from  thv  interior  of  the  intestine  into 
tbs  blood  "  and  "  from  the  blood  into  the  inleriur  of  the  inuatioe."  Never- 
llial—  tbe  remarks  which  have  just  been  made  may  be  taken  a*  referrinij 
mont  sspeciallv  to  the  lini  itiaji.'e.  They  lead  us  to  tbe  oonduaion  tliui  both 
fills  and  dilliuible  sulvtancea,  tboii^'h  in  different  ways,  are  carried  into  tbe 
Interior  of  Ihf  villus  by  tbe  activity  uf  the  e])ilbeliuni  cells. 

In  mpect  to  the  second  siage  of  the  abcturptiuu  <>f  dilfuitible  substances,  ]t 
might  be  expected  tJiat  purl  uT  one  or  other  uf  ibcM  •utMtanevs,  part  of  the 
sugar  for  inslauce,  arrived  inxide  the  hiuemeiit  uienihnuie  shuuld  ulip  by  tbe 
npillary  bloodveswl  nnd  iiu.-i*inK  tbniu^h  the  ntenbe*  of  the  capilfary  net- 
work make  its  way  into  i1h-  lacteal.     And  indeol,  km  we  have  Mien,  S  30!(, 


4S0 


TUB   TISSUES   AND   MBCHANISMS  Of    OIOKSTIO.V. 


under  ^■^^tniIl  ciruumilfttioe*  attmo  Binouiit  of  NUgkr  ii|)iMin>  in  uk<*  ihw  vourie. 
But,  tin  w<-  liiivG  hIii)  Mcn,  undvr  urilinitrr  rirc'uiuMtino)^  thi>  ciirn-iil.  kIiM- 
ever  \tr  it*  I'xiu't  nntnn',  from  llii'  narrnw  l}'ii)[>h-H|H>CN  lyin^   iK'Inrvvti  lh« 

S'thcliiiin  itixl  the  <-ii]iilliirv  itil»  tlir  I)l()i>i1-8lri.-9iiii  u  strung  enough  l<>  carrv 
nr  ticnrlv  nil  thu  :<it^r  uito  Ihn  Unnii.  In  lh«  tautblislimuut  of  itiu  car- 
rent,  in  thi»  iirc-onil  siiigio  of  iibforplion  itittuRiuii  alwajs  (ilnra  a  )>(irt.  and 
probably  o  Htill  more  ci)n«{>U'iii>ii»  am)  dccidnl  pHrt  than  in  the  first  eutge. 
seeing  that  tliv  fpicliclfoid  plate  of  t.hi;  capilliirv  wall  i«  a  far  ieae  active 
structure  than  the  olumnnr  cell  of  »  vilhis.  ImWd  it  might  be  open  for 
us  to  i^uDtend  that  lhi«  second  ilage  wta  merely  s  matter  of  ditTusHH).  what- 
ever might  bo  the  nature  of  the  fint  stage.  But  remen)b«rin|^  what  was 
said  nbore,  §  'M'-i,  in  dieciiating  ihi?  traiisuduiion  of  lymph,  it  seems  more  ia 
aci(.s>r4lauce  nith  what  we  ali'eady  know,  U>  coni.'hide  thai  iu  thin  seooiid 
Btaee  also  diffunoD  is  the  twrrant  and  nut  the  master  uf  tiw  liviu];  capillary 
wall. 

A  word  may  be  adde^l  concerniiix  the  special  case  of  the  peptoDOi  As  we 
have  said,  the  peptones  in  being  alMorbed  apj>ear  to  UDd«rgo  a  cbanffo  some- 
where in  the  inueuns  nienibrane.  We  do  nut  know  t-xiuitlv  irbofW  oroow  tlie 
clianffc  talctri  place.  It  seems  probable  ilmt  »>  uuirlcnl  and  difficult  a  cbaitgf 
abouid  require  the  iuterverilion  uf  Kiime  iirtive  living  tiwiie,  ami  we  may 
therefore  suppose  that  it  is  etrvctvd  by  the  epithi^lium  ve\W ;  hnl  wv  have  no 
oxovt  kuowleilge  on  this  point.  If  the  change  bi-  thn:>  cjirritnl  out  by  mHna 
of  tbe  epithelinm  wlla,  tbeti  the  latter  ittagc  nf  iIk'  abmtrption  of  prottifls 
namely,  the  passage  from  the  itpiibeliom  into  tbr  inlvrinr  of  ihr  csinllary  is 
not  a  paiMugD  uf  clitluiiible  [luptuue,  but  of  minii'  other  nun  dil1i]#iblu  kind  of 
prot«tu.  It  may  bf,  howevw,  that  ihn  i:)inngr  l«ki»  plaec  during  the  very 
passage  of  tbe  material  tliruiigh  tlic  cnpillari-  wall. 

The  vi«w  tlinl  Icuutcyluti  are  the  agcnli>  of  the  absurption  of  lal,  by  bodlljr 
taking  up  the  fat  into  their  cell-substance,  has  by  some  been  extended  to 
nroteidg  ;  it  has  been  urged  that  these  Lake  up  proieids  either  as  peptones  or 
in  Bomfi  other  form  and  so  carry  them  into  the  lymphatic  system.  But  the 
•rldenoe  fur  this  view  is  even  less  c-uijviuciog  than  iu  the  case  of  lat. 


AFTER   II. 


BfSPIItATHJN. 


The  i^rurrrvBK  or  tiik  Ldn'os  atcd  IIkoxcuial  I'AnAoai. 

f  SU.  0»E  {wrticulir  item  of  (he  bodyV  income,  viz..  oxygen,  is  ^>«4-uliuly 
■Mnciat«d  with  one  paninilnr  item  of  the  body's  waAte,  \u.,  carbonic  acid,  in 
M  mnrh  a>  Ibe  niemm  irliiHi  nre  iip])lied  fur  the  iutrodudiou  of  the  former 
■ra  mho  ut>«<l  for  the  gettin];  rid  of  the  latter,  lioth  are  gases,  and  the  iugnw 
of  Uw  ofw  a*  well  a*  the  ef-ren  of  the  other  is  far  raare  (le|>eudcnt  on  the 
rimplt  physical  process  of  ditrusiuii  tliaa  uii  any  aciire  vital  processes  carried 
on  DT  aimiu  nf  ti«ue».  Oxyj|[i-i)  passes  from  the  air  into  the  blood  mainly 
hr  diSWan,  and  mainly  hy  iJiil'u-iioD  also  from  the  blood  int^i  the  tismea;  lU 
IM  matp  way  i-arlninic  acid  oattcs  muiily  bv  diffunon  from  ihe  tixsuw  into 
tb«  bluotl.  anit  frum  ih<-  blood  into  the  air.  Wheremi.  bh  ue  hiive  wen.  iji  tba 
arcTHion  uf  tlic  digtvtivf  juic(«  the  cpilhelium-ri^ll  pluyn  an  all-ImportADl 
part,  in  rcspinili'in  iho  vxtntiiM'  uf  oxyftc-ii  fri>m  the  liingn  into  the  blood. 
Mid  fnim  tho  blood  into  thi-  tiiwii>^,  and  ihc  iiawtigi-  nf  carhnnic  airtd  in  the 
ronmry  direction,  an-  atTvclcd,  if  at  all,  in  n  wholly  xtibunlinnte  manner,  by 
ibe  Miavior  of  tbi-  piilmnniiry,  nr  of  ibi^  cniiillury  vjiil helium.  What  we 
famrcbi  di-al  with  in  Tvspinilion,  then,  ill  not  ku  mm-b  the  vilal  activities  of 
any  particular  liaiU*,  ■•  the  varion»  mc«haiii»(nii  by  nbich  ii  riipi<l  jnlcrvhaagB 
between  the  air  and  the  bbtod  is  eKcclcl.  the  mcnns  by  wbidi  the  blood  la 
enabled  to  carry  oxygen  ami  carlmnic  acid  lo  and  from  ihe  tissues,  and  the 
maniwr  in  which  the  several  tiMnce  lake  oxycen  from  and  give  carbonic 
acid  up  to  ibe  blood.  We  hare  reason:*  fur  thinking  that  oxvgen  can  be 
taken  into  the  blood,  not  only  from  tho  liing«  but  also  to  a  certain  small  ex- 
tent from  the  skin,  and,  as  we  have  eecn,  from  (be  alimeniary  caual  also ;  and 
<mrtmiic  acid  certainly  |<aflse»  anay  from  the  skin,  and  ihniugb  the  variuiu 
•fentioaa,  as  mcII  aa  by  the  lungs.  -Slill  the  lungs  are  so  eminently  ibe 
channel  i)f  the  interchange  of  gascH  between  the  biAly  and  (he  air,  Llmt  in 
dealing  at  the  preaent  niih  respiration,  we  sball  conllue  imr^lvea  entirely  to 
palmonary  r^piratiun,  leaving  the  consideration  of  the  subsidiary  rwpirainry 
piucwu  till  He  come  to  fiudy  the  secreltoDs  of  which  they  respectively  form 
pan.  We  may  turn  at  once  to  ihv  Htmciure  of  the  lungs  and  bronchial 
paMagta.  including  in  ibe  latter  the  trarhea  but  leaving  the  larynx  until  »o 
coma  to  study  ihv  voice. 

S  S16.  Tbi:  lung  takes  origin  a*  a  divcrliculuni  fmm  the  alimentary  i-aiiaU 
and  we  may  cuuiUler  it  a*  a  large  branclied  H[ieciBlly-twHlifie<l  gland  line<l 
with  mucous  mvinbrane  and  eonsisliug  of  a  r»nducting  portion  and  a  M.-crL-tiiig 
portiun;  the  trachea,  the  two  bronchi  inln  which  thi>  ([fvldea,  and  tho  numtr- 
ooa  brotKhia,  or  (mailer  jMUHgi-*  branching  out  fnmi  tbcae,  rrnrawnt  ducta, 
oik)  tho  ■ecnrtinz  alvtoli  uf  nn  onlinary  gtund  an-  reprcsenti-il  by  what  we 
shall  |>rtaentlY  descrilM  as  aim-lU  or  imlntoiiary  alvooli ;  but  il  must  be 
bomr  in  mind  that.  Mt  we  Have  jurt  Mia.  active  secretion  by  tltc  cpilholium 
Iming  these  pulmonary  alveoli  b  reduced  to  a  minimuin  or  pombty  abient 
•llnjRthrr. 

Tb»  complex  strticturo  of  the  mammalian  lung  will  be  rendered  earier  of 


ooiiiprehervion  if  w*  nrat  Bay  ii  few  words  on  the  structure  ■ 
luiiK.  nut-h  8B  that  of  ilie  newt  i>r  the  frojf, 

1  be  lunK  of  the  uewt  is  a  lun^  oval  sac  opeiiJiiK  hj  a  short  mii;:1o  lironcbtu 
into  a  very  short  trai-hea.  It  mav,  by  iDllatiiin,  Ix.-  largely  ilMieiiiled,  and 
when  the  premure  U  renidveil  collapara  and  sliriuks  to  a  very  stnsll  bulk. 
Its  walb  are,  therefore,  highly  elastic,  in  tbe  Rose  in  irbicli  we  have  lo  on«D 
need  ihnt  wnnl.  Tbey  coiisiBt,  like  titucuus  uienibraiie  «bewhere,  of  au 
epithelium  resting  on  a  coQiieciive-timiie  baBiB,  This  ui>nDecliv»-tMMie  baait. 
which  is  very  thin  wh«n  the  lung  ia  diBtemled,  conlniii*  n  very  large  number 
of  eWlit-  Ubrcs  of  vbHoub  »m-a  but  inustly  iiniall ;  iheae  give  the  wall  ibt 
elaiilicity  JtiKC  spoken  uf.  'the  piilniciniiry  arlery,  carrying  vcnuuii  bluod, 
«livi<les  iiuir  the  neck  of  the  tac  Into  br»uche.s  which,  running  in  tbe  ooo- 
Deetive  (issne  of  ihi-  wall,  brcnk  up  into  itn  exceedingly  clo»r-»ot  nrlwork  of 
rapillurie»  inimciHult'ly  nndcrnrath  the  epltbeliiiui.  Tbe  cnpillntint  are 
tbcrnwlvos  rvlatively  ividt-  but  tho  mwbi-x  are  verj"  nurrow,  being  in  mnnv 
casein  !<'»  thnn  the  dinmclvr  of  a  eapillnrv.  Tlic  epithelium  over  the  whoM 
of  the  sae  consiMi'  of  a  nngle  luycr  of  relU.  which,  ('xicpt  at  iho  iii-ck  of  th« 
mc,  are  modified  into  thin  philes  in  n  »oni<-H'hai  peculiar  manner.  Tbrwor 
more  cells  converge  together  townnl  the  middle  of  each  of  the  tslantls  or 
iDcafatt  of  the  capillary  network.  The  nucleus  of  each  cell  in  placed  within 
the  area  of  Ihe  nie»h  or  iebind  near  the  conveT^gence  of  the  cell  wilb  ila 
neigbbom.  but  a  large  part  uf  tbe  call  stretches  over  the  capillary  surround- 
ing the  i'land  to  meet  a  similar  extenaioa  of  another  cell  whose  oucleiia  it 
placed  in  the  next  island.  Tbe  part  of  the  cell  in  which  the  nucleus  is 
placed,  though  thin,  has  some  little  depth,  but  the  txirt  of  ibe  cell  stretebing 
over  the  capillary  ia  reduced  to  the  merest  titm.  lienee  each  island  or  luesa 
is  uceupied  by  the  nuclei,  and  by  tbe  thicker  parts  of  two,  three  or  more 
converging  cells,  while  the  capillary  network  surroundiuj^  the  island  i*  »c|wi' 
rated  ftoni  the  interior  of  the  lung  by  tbe  extremely  thin  tiat  oxjuaiMtou  uf 
cells  heloiigiug  to  that  and  to  the  neighboring  islaniis.  The  blood  (MSsiiig 
Ibrougb  the  capillary  if  m  couM:?i|ueiRi-'  separated  from  the  air  in  the  lung  by 
liothinji;  luort  llinn  tbe  capilbiry  null  ilnelf  and  a  GIni,  wbieh  has  not  uveo 
tbe  Ihickni-ito  of  a  Hut  eptlbdium  cell  but  is  onlv  a  wing-like  extension  of  a 
cell  itself  Hal.  The  cttpilliirtii'  nie  in  Ittcc  Imbedilcd  as  it  were  in  tbe  epilhe- 
lial  layer.  By  tbi»  nienn»  iIj'  [Diriilion  between  the  blood  and  tJi«  air  is 
reduced  to  alinoi>t  the  nnrrniM -i  |iii.>.->ible  liuiita.  Ni-ar  ibc  neck  of  tbe  (*e 
the  network  bccoruvs  more  open,  und  nt  the  neck  ibr  pr<culiar  epithelium  just 
deacribed  somowbat  suddenly  chnngi-s  into  a  single  layer  of  rather  short  but 
Otherwise  ordinary  columnar  ciliated  cells. 

Tlic  outer  pari  of  the  c<inneclive-tia»tie  basis,  away  from  tbe  epilbetium. 
becoming  wmcwhat  looser  in  texture  but  slill  richly  provided  witb  elaatio 
libm,  contains  brHdes  Ibo  small  arteries  and  veins  belonging  to  the  capillary 
networks  many  small  bundles  of  plain  muscular  fibres,  chiefly  running  in  a 
circular  or  transverse  direction,  ^ninll  brandies  of  the  vagUB  nerve  Mtaa  to 
the  lung,  running  in  company  witb  tbe  pulmonary  veins;  connected  witli 
thcM,  toward  the  unper  part  of  tho  lung,  are  numerous  small  groups  »f  nerre 
edJs.  The  nerve  fibres,  which  are  cbicdy  nou-mcduIlal«d,  though  niedullated 
Sbm  are  also  present,  end  probably  in  tbe  muscular  fibre*  or  in  Um  btood- 
Tenala.     Branched  pigment  cells  are  also  present. 

S  317.  Tbe  lung  uf  tJie  frog  repeats,  in  structure,  most  of  tbe  featuras  of 
Ibe  newt's  lung  Just  describecT  bm  is  more  eomplicntcd.  'Hie  cavity  of  tlic 
Bac.  especially  id  ita  upper  part,  is  broken  up  by  a  number  of  partitions  or 
septa  prujectnig  into  tlie  interior.  Each  septum  is  a  fold  of  tho  wall  of  ibc 
cavity,  and  con^iaiji  of  a  middle  basis  of  connective  tissue,  cuvered  on  «cb 
aide  with  epithelium.    From  these  primary  septa  start  in  a  similar  manner 


438 


<f^m  7'*^*'^  tfl*  of  ■  similar  -triitnure,  projectiDg  into  tlM  open  ohnmban  or 
2ff  .■"vUtMoTthe  whole  sac.  formt^d  by  ihe  uriiDary  MpU.  and  dividing;  UlSM 
^H  'Mo  MMller  upcu  t^liBntbera :  uid  miiny  ol  lti«te  wcoinliirr  ^teptn  benr  in  a 
^H  ''Mikr  nuiiKr  ritniUr  tentarj  segilu.  iliviiliiif;  thv  ttfcnnilnry  diiimliur<  into 
^H  '''^''^  chambent,  or  nlveuli.  In  lliiH  way,  i!ii|itfciiilly  in  iln  ujip-r  purt,  llie 
^p  'VritT  of  tbc  lui))i  i^  divid«il  iou>  a  buntrymnili  nf  chnmlK-n  or  iilveoti,  the 
I  *<iniilrf  or  tertiary  alveuti  ojH'iiiu^  iiilo  ihv  M^'imdnrv  chnmlterf,  the  ncond* 

"7  into  ibf  primary,  anil  tnc  primary  iiilo  ihi?  |cvn«ml  <-iirity  uf  tlic  lung, 
I  •fcitTh  in  lhrti{i[wr|«rt  cif  itic  lung  it  rcducnl  toawntrnl  piM>itg<?  surriiundnl 

^m     V  C^M  hnfK'yc<>iQt)  work  uf  the  <'hflm1>rn!k.     In  tiuwin^  down  lr>>m  lh«  upjior 
^1  t"  Llw  lower  |Hirt  of  the  lung,  we  find  rhc  wjrtii  bccQiwc  fewer,  iind  the  hunejr- 
^M  **'>t>l>  man  o|X'n  ;  the  Ivrtinrr  aepta  toon  (at],  then  the  Kecondnry,  and  at  tn« 
^B  '*S^  boCtom  or  vnd  of  the  lung  mat  the  primary  lepln  arc  nWnt. 
^B^  ^Sach  tcptuia  conti«ti>  of  a  niiddlp  hati»  ot'comioetive  tiMUe,  rich  in  clutic 
^^^I^^Kmta,  provtdcid  with  cI'mmxcI  iiftworl<»  of  cnpillari^  and  coverc)  on  eadl 
^^F'^'^h  with  epttbelium,  the  elinracter'  of  (he  fpichelinni  and  it#  relati>>n  to  l)>« 
^FJ^C^tllartos  D^n}[  okuch  the  uuitc  nit  in  ihe  newt.     Uence  tn  cuch  Mjituiu  the 
~^«^  isfreely  ex[>>K'dtoth«niroDeftofa«d«of  ibenptum:  and  the  ari«ng«- 
**^*iti>f  tli«  hunL-ycuiiibii'orkof  tbealreott  iacrvasea  laricely  the  total  surnee 
*^  l2?^  '"  ''*"  "''■  *'"'  *'  'I'l^reaaeo  the  expoenre  of  the  blood. 

rhv  y]sia  muacular  tibres  present  in  the  general  wall  of  the  lune  peas  to 

^   Certain  ext«ot  into  tite  Mpta.    A*  in  (he  u«wl,  at  the  neck  of  the  sac  the 

—  P^vuliar  llal  "  rupinit'irj'  cipilhtlium,  for  now  we  may  ptTbK[iA  so  call  it, 

^^T«%aitgn  into  ciliated  epitWIium:  trace*  of  ciliated  epithelium  are  aliio  pmeot 

H^%  iho  exIfvnM!  endii  of  the  M'pla. 

^^L       S  318.  Kat-h  of  ttu-  lobn  (if  whitth  the  mammiiliau  Iuiik  i*  nnule  up,  maf 

^^^«  moKt,  at  limn  aomfrwlint  indiKtiuetlv,  tn  br  divisible  into  lubulc.    Th« 

H'afw«*eAi».  nr  diriaioDH  of  th«  right  an(f  Icl\  bronchus  rcapectiveljr.  dividing 

*lirboli>R>oUFly,  and  running  between  the  lobuIc«  as  interlobular  bronchia, 

wccdrupanied  by  branches  of  llie  piilnit>nitry  artcrv  and  ]>iilmi>iiury  veins, 

Qlutlly  plunpf  into  and  end  in  lobules  as  "  lobular  '  bronchia.     Within  the 

lobule*  the  I'ibular  bronchia  diviilo  in  a  mnre  or  !««  n?otangutnr  manner 

into  snalJer  "  intralabular"  bronchia  or  brnnrJiiJrr,  often  apukcn  of  aten  as 

tatetKthr piMtayt*.     [Fi;;.  l'^5.]     Bicb  such  bronehinle  ends  in  an  eolaree* 

toefit  haviii)*  more  or  Imb  the  form  of  an  inverted  cone,  called  an  infundioH- 

i^wK.     [Kig.  IJC.]     Each  infundibtilum  repeals  to  a  oerlaio  extent  llie  strilo- 

Uir*  nf  the  whole  lung  of  the  frog,  or  rather  \a  inlernmliaie  between  the 

laag  of  the  frrtg  and  tiiat  of  (be  newt.    The  more  or  leea  conical  eliamber  of 

ibo  infundtlnilum  narrowiuK  into  its  broDebiote  in  divitled  br  a  number  of 

■•pU  into  iocondary  chambers  of  a  (omewhat  pulygnnal  form,  tne  Mpta  lieing 

simple  and  oat  as  in  the  frojt  bearing  aeeotidnry  and  tertiary  nuptiL    Each  «M 

tblM  Moondary  cbanilien  ix  called  an  almoiuA ;  it  hiu  a  haw  which  i.i  jiart  of 

tbo  wall  of  tbu  infundibulum,  Hide)  which  are  firmefl  by  the  septa,  and  a 

BMjath  which  openit  into  the  miernl  cavity  of  the  infundibulum  and  *<i  into 

lb*  brMtchiola.    Kimilar  but  Icm  deTdoiMsl  iii-iitn  arc  prMJi^ted  into  the  more 

tabular  cavity  of  the  bronchiole  iUelf.  dividini;  it,  lea*  oomptcttily,  into 

alveoli ;  heneu  the  name  alvwlar  pn««g« ;  iIm^i  wholly  ditinptiVftr  balore  tbo 

bmnchiolc  on  its  way  out  from  the  lobule  bevnnics  n  delinilv  tironehbini. 

Each   infuiidibuliim  is  surmtimlt^l  by  connective  tissue  carrying  blood- 

1 1  Ml  ill  and  lymphatics.     A   number  of  tnfundibula  with  tiMir  raspeetiv* 

branoblolus  are  b-jund  together  by  i-»nnc<^'t)ve  tisnis  varryinE  larger  bloo>i- 

vmmU  Io  form  a  lobule,  the  bMiK-hiidr  joining  u*  form  the  loTiular  bronchia. 

number  of  lobules  are  Iwond  to^'ether  with  interlobular  brrjuchiii  and  still 

irgcT  blomlveHels  to  form  a  lobe,  and  several  lobe«  join  to  form  the  lung. 

'bm  a  lung  is  inflaied,  and  vrbcu  as  after  deufa  the  bloodvessels  arc  for 


I 


n 


43-t 


RKiPIBATIOK. 


1 


l!i«  moot  jwrl  cinplietl  vf  Uloud,  tlie  infgiiiiibiitii  niih  their  ati-«oli  form  br 
br  tbs  ]{rt'HU>r  (iiirt  i>f  itie  bulk  of  ibe  Iudj[.  Uenc«  a  sevtion  takeu  throufjh 
ft  hnrdtiMt)  uikI  iiirpurtil  infliiud  luiiKBcctm  to  be  made  upalmmt  m holly  of 
n  nuiuli«r  of  [N>l^gDDiiI  ur  fre<|iiirDtly  Mxa^nsl  spaces,  winch  are  secliuoa  of 
alvfoli.  iiml  iimong  irbirh  iim  imi>ii  M-ctioiia  in  variuua  plniiie  of  brunvbia, 
Miiiill  UH'I  lat)M  anil  of  MixiclvtwutlK ;  here  unil  tlit^rc  lli«  sedioii  may  duclcMB 
titi'  ii|>«-utiig  of  a  bmix'hioli-  into  uii  inrMDiiibuhitii.  aiiil  tbe  divtsiou  of  one  of 
tlw  lobtitiir  broiichia  iiitu  a  nuiiiWr  of  hniiK'tiiolea. 


fna.  m.) 


>^ 


or  A  Uiooiiv  <Ciiii'rEfiinii>l  iiuiiTt]>  air*  ■kmiki.    litataltfil  Ui liitm,!    a.  tvcmimt  bron- 
(llt>l  1«Ul:  bit.  lafUmikiLla ,  (  •-,  alTn-Ur  n—mii.) 

IPm  19. -Tw"  iuiii.1  aiMiii  iir  Aii-i'nu. oH  tRTi'miiuut.  u •■ :  Willi  klt<r<tllii.  Iih, kihi  Uia 
klvtvla'  [■■«««,  *r.  wtUi  wliirk  Uk  •lr-«41*  poniuunliaM.  Prom  ■  rmlwrn  phlict.  (Aler 
KdU-KUt.  I 

$  319.  Tlir  itifuiidibdlum  irpeats  in  atnictnre.  tu»  we  have  said,  llie  liitiK  af 
Uie  uewt  or  ibc  frop.  A  wptuoi  or  uall  bvtwecii  two  coiitigtioua  alvenli  oon- 
liaU  uf  a  thin  mnliaii  basis  of  coDiiective  listuc,  ciowded  with  a  clow-art 
rnpillary  network,  aixl  covered  on  each  side  with  an  epilbeliuni.  Tti«  oon* 
nective  tissue  is  lichly  provided  with  flue  elastic  fibres,  but  the  ordtnaiy 

E^latiiiifi-ruus  fibrillft>  am  ituperl'eclly  dcvdnped.  lti«  blood vetoela  h«iiig  i»  h 
rgc  t^xteol  imbedded  iis  ii  nere  in  n  I)<>ni0]i«iii »ui>  maiiix.  The  acptniu, 
Oipvcially  loniird  iia  atiinniil,  is  ol'len  no  thin  ibat  thi-  ciif>illury  b  cxpiiiH-d  in 
iM  air  on  buth  sidr4.  TIh-  ct^lla  of  llie  rpithvliuin.  which  an  iiiut'Ii  boiler 
■liOWD  Id  ttiv  Itin^  of  n  yi>iiti>;  iininiiil.  and,  iiidriKl.  t*  in  tin:  adiilt  vrry  difti> 
eiilt  to  WCi  art)  for  ihc  iniut  purl  t niiiaf'otnti'd  intofiiiall  tlitl  tmnHjiarvnt  pliitca 
iVxim  which  llic  nurl<-i  huvi'  diMip|iear)'d  ;  tiM'ir  millim-H  may  fir  dinliiiiAly 
slwiwii  by  lilvrr  nilinli-  (iv-nlnH-nl  but  oibi'rwiiMi  an-  uttcD  v«ry  itidiitliDcL 
BotWKti  tbi-M'  cl<«r  tint  plat*-*  iht'ri'  iiccur  •niall  gmu)M  of  itIIh  di>liii|iui>ihcil 
hj  powtMint:  ntu-lfi.  and  by  iltcir  cell niitmliuicw  i<tiini  j.'rai)ular  aiiil  »[NintDg 
wild  ibe  oroioaiy  rciitfeiiiH.  Tbi-M  granuliir  w\h,  which  nn!  ihii-kcr  ihnD 
tlw  clear  platca.  ur«  placed  in  i;rou|»  in  iImi  nie»liu»  ol  tbc  capillary  nrtworks, 
•u  that  tbi'  mpillnriw  tlwiiuctvcs  ant  oorend  only  by  th«  thin  ducImi»-I«« 
[dntce. 

Tbo  wall  of  tlic  infiindibuluni  which  foniu!  tbe  bnM«  of  the  ecveral  alreoli 
tins  B  Mtnilnr  flnictiirv,  aud  Is  Itoed  nith  au  cpilholiuni  of  similar  characi«r, 
Ihe  ch'H'f  ditlcrcncc  botwceu  tbe  sidea  and  tlM>  base  of  an  alvoliis  bcin^'  that 
while  ibc  bUiul  iit  lh«  caiMllurieg  of  (he  latter  is  exp-iwd  to  the  air  of  the 


iilv(H>litiiuii  th«aietid«  nnly.  Umt  of  lli«  JurnH-r  is  uftcn  ox|wm>I  on  both 
guK-w  ut'  even  ilio  rnim*  cftiMlIury. 

()  330.  Ill  (lii>i'riliiiig  the  Immchial  pntMgei  w«  hii<l  perhnps  bottrr  Ix^i^in 
with  the  irnt-hcH. 

The  (nichm  consisU  or  ii  cilintml  muroUB  nien>brtiti«,  resliii^;  on  a  cout 
of  connective  lis<tie,  st ret i^t lira l-iI  with  honpH  or  iiujtorfcci  ring's  uf  cnrliln;^ 
BQ<i  provide'l  witli  ik  cerluiii  aiuount  uf  plain  muscular  tissue.  A  vertical 
section  of  tbe  mucous  luembriute  showe  nn  e|>it}ie>iii(ii  cunsislio);  of  tliree  <ir 
more  layere  of  cells,  thoao  in  tbe  uppertuoet  layer  beiuji  columnar  eiliateit 
eells  ($9^1.  nod  thuot^  in  the  lower  layers  amall  rounded  cells,  the  cell  Hnl>- 
BMitce  beinK  si'anty  in  proportion  to  (he  nucleus:  it  in  suppcaed  lIuU  some 
of  ihcM  email  eells  may  at  iiiii»  develop  into  ciliaKtd  <x]U  in  onler  to 
replace  loc.  Among  ciliated  cella  are  »eeu  n  trerliiin  number  of  yoblet  cells 
(i  2lit!).  Beiieatb  the  epilti«liiint  nimt  a  Ikirly  ilinliiiRt  linwrneot  inembraHC, 
WkI  below  tbU  in  turn  U  two  some  lint!  retieulnr  tiiwuc,  like  tinti  in  tlie 
unall  intCMlinc  <$260j,  contiiiniup  in  it«  lueNhc*  a  nrlnin  number  of 
leiiciHryte«.  Mtx<^  up  with  the  reltciilur  tiiwue.  which  in  iliflcrent  animaU 
Tiiriifi  much  in  ibe  amount  prrsent,  arc  tt*a  ii  certain  but  vitiiabic  numlwr 
of  line  T'liu'lic  iibrra.  Then  Mruclnrca  constitute  t<welher  tlw  mucous  mum- 
brane.  Ih-Iow  which  is  b  somflwhat  conspiciwui  layer  of  elastic  fibres, 
nrriin(;ed  mor^  or  Icra  !n  n  network,  but  running  distinctly  longitudinally 
Wid  funning  a  longitudinal  elastic  layer  separating  the  mucous  mombrmiM 
above  from  the  looee  submucous  conncctire  tissue  below.  In  this  submucous 
tiwiie  are  placed  a  number  of  small  mucous  or  albuminous  glauda,  like 
those  of  the  a;eopbagus,  the  ducts  of  which  iMtasing  through  the  elnslic  laver, 
MicuUr  tbsue  and  tpiibelium,  open  into  the  csdaI  of  iho  trachen.  The 
outer  part  of  ihta  submucous  tissue  forms  a  sumewhni  denser  cout  of  crninec- 
live  Uasue,  ia  which  are  lodged  hoops  of  hyaline  cartii»Ke,  that  is  to  say, 
rinjca  vihteli  are  imperfect  beiiind.  Siretchint;  tmosversely  between  the 
ends  of  each  hoop  of  cartilajce  are  Mveral  bundles  of  plain  musi^ular  fibres, 
eomjil(.-iing  the  ring  aa  it  were  bv  a  lutacular  band;  a  few  lon^'itu<li»ally 
tUajHixMl  mnscnlur  bundled  may  a)tu>  be  seen  outside  the  trao.irerw  bundltM. 
Tmw  two  aelo  of  muM-ular  lib'rM  may  be  taken  as  being  the  remains  of  tint 
original  cirmplete  double  muscular  cout  of  the  atinieolary  canal,  almost 
ol(liiera(c«l  by  tbe  intrtMliietion  of  the  carlilnginous  hoop«. 

TIm-  main  |^Mir|>aM  aorvetl  by  ihrne  wveral  oCructure*  iK  (o  pmvide  a  widt^ 
Bvxible  clastic  tube,  the  bore  of  which  ntmiiins  liirgi;!  ami  oiii-n  iind  tlw 
Ibling  ainooth  during  the  branding  of  the  tube.  Tbi-  mueoun  (luid  Mwnilnl 
"by  tM  f[oblM  evils  and  sniiill  gliinds  liel|iH  to  arnail  ixdid  parlicb*  ciirrii.tl  in 
f>y  tlw  invpireil  air,  nhile  thtt  cilia  arc  continually  driving  that  mucus,  with 
tite  |>»rlicW  cntniiglcd  in  it,  upward  to  the  Inryiix  ami  mi  into  iho  mouth. 
Tb"  clastic  layer  ada|it»  the  mucous  membnne  tu  the  variations  in  the 
length  of  tlw  tube  during  its  bending,  and  so  keeps  iCMHOotb.  The  traiw- 
vera:  niusoles  by  conlnicting  can  wimcwbat  narrow  tlie  bore,  when  required ; 
but  llietr  ellect  in  this  direction  can  be  slight  only. 

i  321.  In  iKUMing  from  the  trachea  to  the  bronchi  an<i  lari^er  bronchia 

Iyig.  laTJ.  tne  chief  changes  to  be  observed  are  that  tbe  earlilagc«  are  no 
DDger  io  tJi«  forin  of  rei-ulnr  booi<e,  but  are  plate»  place<l  irre(;ularly,  be- 
^eoioinx  smaller  and  more  irregular  in  di»)iu6iliun  the  smaller  the  tube,  and 
that  llie  transverse  muscular  <lbn»  beoome  more  and  more  prominent, 
funning  a  distinct  circular  coat  of  some  thickoeas.  The  carttlaKes,  sup' 
portt^^d  by  a  fibrous  coat  of  connective  tiatue,  lie  entirely  uui^iide  the  uius- 
eular  oiai,  and  the  small  glaudii  have  their  ducts  lengthened  hi  that  the 
bodio  ol  the  gluuds  instead  of  lying  in  tbe  Hubmucona  tiHiue,  lie  outatile  the 
mtiacular  layer  which  is  pieixi^l  by  their  ducu.    The  tube  become*  now 


I 


ASm 


RKSIMRATION. 


i 


diatiticlly  u  niiiMular  tube,  tboufrli  ilie  fMeoey  of  ita  b-ire  sod  it  c«rlBln 
iin;4Niiit 'or  rif^ditj  ooinbiaed  wilD  tlexibility  U  Mill  wcured  by  tb«  «»!• 
Ur«d  plale*  aod  futlcw  uf  oirtibge.  After  acatb,  amag  (o  tbe  coatrftction 
of  lh«  droiilnr  niuncular  flbraa,  the  mucoaa  ia«nibraii«,  like  th«  internal 
i>Ml  uf  mn  anerr  in  tb«  nanw  dmunulaDee*,  b  ihrowo  into  lon^tudinal 

in*,  in. 


fABT  C¥  *  TiAlon-nH;  Satkin  or  *  Imomiiiul  Tt  nn  rti'S  mt  l'i'<     MnoitiM  MOdUJO. 

«,Mli«i«lniii«M>U)r«r:  ft,  nuntiilMr  U}*r :  r.  viiMnal  nbtmnlaxw;  4,  vHO»'l'l 

lajr^r;/,  iinauf  tlw  (iimmlultiiii  iltpatl.  | 

In  tbe  ntmllor  bnMiclitu  ihe  cMrtiU^es  dlaappciir  alttmtlMr,  nod  tbo  tub« 
then  coDsials  of  nn  outt^r  i-oiu  of  connective  tiMiie  wilh  abiindnnt  elastto 
flbr«B  KtA  a  oonaid«ni)ilc  number  or  ciroaUrly  difpuaed  muscular  fibrw,  and 
an  inner  cuni  of  iniicoiia  membrane  uith  ita  pVn  elaatio  layer ;  the  supply  of 
•mall  K'nuds  etill  (xiniiniiee. 

As  one  of  tboee  bronchia  plungiof;  into  a  lobule  dividn  into  brooohioleri, 
the  culuinuar  cells  of  the  muootiit  membrane  lose  their  cilia,  become  shorter 
•0  as  to  be  cubical,  and  are  disposed  in  a  single  layer  or  at  most  in  two 
Jayttnonl^.  At  tbe  same  time  the  muscular  fibres  become  more  scanty, 
and  lira  iliii|Kieed  not  as  a  continuous  coat  but  in  scattered  rings,  tlic  omnee- 
tive'li>«o<>  oint  becomes  ihioner.  and  tbe  glands  disapjiear. 

In  lilt-  bmncbioka  tbemseira  an  tbey  prepare  to  opi'n  inlu  inlundibuin, 
the  c]ntbeliiim  oslla  beeoroe  Sat  Ihougfa  sltll  rvtaliiiuK  urunulnr  cellbudiea. 
AmotiK  thew,  however,  may  novr  be  aeen  iMtehw  in  which  tlie  n-Ua  are  Aat 
tran*|>iirpnl  plaleit,  many  of  mhieli  d<i  not  i>owe*e  a  nucleus ;  ami  toward  tbo 
JnAiwIihuliiin  ibent:  jmtchat  iiirruuic  in  number  until  the  Kpithi-lium  niMintes 
ihd  lOinraclcr  which  w<'  prtivinunly  dcrn'rilied  ax  I'hamctrrL-iii?  of  xhf  alveoli, 
'llic  nniKi-ular  fHirra  ilL-apimar  iir  Hprvnd  out  lungiliidinully,  ami  the  [tre- 
VMMialy  compact  layer  cifcWtic  lil)r(H  now  lnvixiini  M'nttcred  an<l  upreail  out 
over  the  Blvi»>li  of  thr  iDrniKlibulum  and  brimchi<il<-.  In  thin  way  tbe 
rtructurtt  of  the  bronchiole  gradually  nivritc"  into  thai  of  ati  iiU'im1u». 

Jr3SS.  In  an  iDfuudilMiliiiii  and  in  each  of  its  conotilin-nl  nivuoti  what  we 
may  oohskUt  as  llie  origiunl  wall  of  a  pulmonary  piiwsge,  namely,  a 
tuucous  memhraiH)  iM-)>ara(ol  br  ■iibiiiiirou*  conncciive  li^iic  from  a  mu»- 
eular  ooat.  is  rwlucod  to  a  thin  sheet  of  connt<«-tive  tiwue  in  which  bundles 
of  fibrilla'  are  wiutty  or  even  nlwvnt,  lUhl  which  In  nitli«r  to  he  considered!  as 
a  Rienibnino  of  h»magi!n«o«is  nature  omtainiiii;  imbedded  in  itself  a  larye 
Uuiuber  uf  clastic  libnm  and  Hbrils  with  a  few  connect ive-liiaue  cnrpusclea. 


STBl'CTDBie   OF   TOB   I.UtfOS. 


437 


I 
I 


I 
I 


aiid  tt  network  (if  cftpillaric*  ao  olotte  Ml  ilint  the  iiK'.inbrttiie  Metns  to  tw 
DMrtilr  elastic  luatrriNl  filling  up  thu  lucahts  of  the  nutwork.  On  lh<t  uni- 
m\c,  ttiiii  rtt|>illNry  nu-nilirniiii,  if  n\'  may  M  oil  it,  t^  oatilJnu'Mif  iritli  lliff 
lootNir  onliiinry  conm-clivc  tiMuo,  iitil),  however,  ocmliiiiiini.'  nt)iin<lniit  oImIio 
cIvnwnU.  which  ciirriw  the  »nmll  nrtiM-int  Btiil  v«-iii«  K"'i"li  t-i  anil  ottiiittig 
from  tho  ciipttlary  network,  nnH  which  uiiilm  tUv  inriinilihiilu  ■ii'l  hron- 
cl)ii>k«  inU)  lohulra.  On  the  iTtfiHo  li«<  the  nltriiualivl  i']>i  I  helium,  all  the 
cells 'if  which  arv  flat  ao'l  soiiic  of  irhich  arc  mere  nucU-UH-lew  plau«.  Thft 
muscular  librra  hav«  either  wholly  disappeatvil  or,  iicmrOiiig  (o  eome 
obMrvert,  penbt  u  a  few  straf^'Ung  Itbree  s^trMtdiiig  over  tho  infiiDdibulum. 
The  lerminal  poriioo  of  the  pulmonary  pamage  is  a  sac,  whow  walU  are 
reduced  to  Blmosi  the  grealest  possible  thioness  oonsiatent  with  theii  reuuii- 
toir  verr  KTeal  elastic  power. 

The  bronchial  poasa)^  of  roediuni  sixe  nn  eatentially  elastic  muscular 
tubes,  capable  like  the  arteriea  of  varvinf;  their  calibre,  but  udIcm  their 
muscular  fibrcH  are  Ihrown  inl»  unusually  powerflil  contractions,  remaining 
ulwayn  fairly  i>(k>ii:  the  iunaller  ones,  however,  those  which  arc  devoid  of 
oaniia)^,  may  perha^u  cluoe  by  i-'illajxte.  These  paamgca  are  tineil  by 
miicouji  membrane,  the  edla  of  whioh  aiv  well  formed  and  active,  iinme 
aei'ri'tinjz  mucuH,  and  iithi;ni  by  their  diia  driving  that  mucuH  ouward  (itwarcl 
the  tracnvu.  The  air  wbioh  pn«Nt»  into  the  hmzM  tx  frcfpienlly  lailen  a*ith 
im|>untii->>,  thrw  nrr  cnlanglnl  in  the  niu'-ti*  of  Uie  pnfwiy™,  especially  tho 
gmnlh-r  on«i,  and  m  aro  i,-itli<T  carrinl  upward  in  tlie  miieua,  or  lut  wc  ahall 
Me  othvrnixe  di«p>»ed  of. 

ThiT  latT^r  piKKiigi-ii  arc  open  flexible  inhw  beooroing  more  rigidly  open, 
and  l<w>  »UM«ptil>li'  lo  change  in  calibre  by  niitwular  conlrnction  llie  larger 
they  art-. 

§'3£S.  The  tungs  are  well  provided  with  lympliati<*>.  The  reticular  tiasuo 
tmderlyiiig  the  epilhrliiim  of  ihe  mucous  mfmbnine  i:s  here  ami  there  devel- 
opei)  into  masses  of  true  adenoid  tixsiie  eri.'wded  with  leucocytes,  that  is  to 
say,  into  more  or  leas  oompletetv  diHi^reDtiateil  Ivmphalic  follicles,  and 
similar  Iblliclea  are  met  with  in  deeper  partA,  Among  the  llat  polygonal 
epithelioid  plates  which  form  the  eurfaoe  of  the  pleural  niemhrane  inventing 
the  lung  are  numerous  stomala  (^291);  ami  during  the  rhythmic  move- 
ments of  ihe  lungK  in  breathing  the  lymph  or  scroii*  fluid  of  the  pleural 
cavity  is  ooniinually  being  pumi)ed  into  the  lymphatic  ve«»eU  of  the  lung<i. 
These  lymphatic  veiaeK  arising  from  lymph-spaoei  iu  all  parta  of  the  lungs 
including  (he  runuective  ib»tH!  around  tbo  alveoli,  ami  running  in  the  ooa- 
nerttve  liwiiie  binding  together  infnmlibula,  hnmchial  liib««  ami  bioodvraMli 
into  lobulea,  and  the  lobults  into  IoIk-j,  find  their  nay  at  la.-<t.  alV^r  lraven>- 
tag  MV«ral  lymphatic  (l>r»nchial)  gianiU  to  tb<-  roots  of  thtt  luugH,  wliencO' 
Eliey  pan)  from  the  lelV  lung  Id  the  thoracic  duel,  and  from  the  riglit  lung  U> 
the  nght  lymphatic  trunk. 

The  impuritien  in  thi*  in.-<|iin-<l  air  spriken  of  above  ux  arnwled  in  tho 
murns  lining  (he  bronchial  |>ii.i«i^'n>,  ollon  maki*  (hvir  way  (hrough  the  epi- 
theliom  into  the  lymphittii's  i>t<l<iw,  anil,  ''Hrrii'l  away  in  llic  lymph  elrmm, 
are  niim  ri^t«iu»t  !n  lh<'  brxrichinl  lymphatic  glaml«.  At  limcH  these  glaiKb 
boeoriM'  in  (hin  way  loaiU^l  with  jairlii-ti;*  of  carbon. 

Tii4>  blooitvnMU  of  Iho  lung*  do  not  call  for  any  special  comment  mv« 
perliape  tliattha  pulm<mary  veins  are  destitute  of  valves;  and  that  special 
arteries,  the  bronchial  arternv,  starting  from  the  aorta,  are  distributod  to 
the  walls  of  the  bmnchial  naamges,  (o  (be  blao<lvemeis,  lo  Ihe  lymphatic 
fdantta  and  (o  the  sub-pleural  lieeuo,  llie  blood  returning  from  them  along 
tne  bronchial  veins  into  the  ngbl  vena  aivgoa  on  tlie  right  side,  and  into  ihe 
superior  intercostal  van  on  tlie  left  fli<le. 


|324.  The  oervet  to  tlM  luiif{a  cuitie  cliieSy  frcnn  rStrS^aST  At,  on  < 
■tde,  tlii;  vagun  iiuTVt  wiodl  round  tlv^  nmt  i>f  ilie  lung.  i(  Kiv»  ofl*  in  fnmt 
bnuidte*  t»  form  the  viUrlor  piilm'Hiary  jilcxux.  and  l\ti-n.  hehia>\.  *t<iuret 
bnuid>e>  to  form  the  prMlvrior  ]>iilin»nary  pirxux.  BdIU  llin*i\  but  rtfii- 
eM\y  tbc  luLUir,  nn;  joinnl  hv  liUroi-nU  ff»ni  lliu  sjm^Uivlic  tyslcoi,  man 
Miwcrnlly  from  lh«  socDni),  tliinl,  unil  fviirLh  ihnrjicic  guogtia;  >di1  it  ii 
iiiiiinliuiiiM]  l>r  some  (Imt  Sbrv*  piu»  ilirccl  from  ihc  K;>insl  (inivrcoMnl) 
oun'cf  intu  these  piilnir>nnn-  pIcxiiiiM.  Thn  iipp«?r  p:irl  of  tbv  trnohM  k 
supplied  by  twigb  from  the  rocnrrenl  laryngeal  norvo  on  neb  sid«,  uid  lli« 
liiwer  jutrt  by  tiriga  (tracheal  branches),  coming  diracl  from  tho  vngni 
trunks. 

Home  of  tbe  nerve  fibres  thus  renchin;;  the  lung  nlung  the  vagut  nvm 
are  eRi-rent  fibres  for  the  inufculnr  tibrce  of  the  broD(?hial  iiBSSages  and  tni- 
chea.  llut,  oa  we  shall  see,  the  chief  and  most  imporlaot  Bbra  are  aflereni 
Kbr»  c"noerDO<i  hi  Ihe  regulation  of  respiration.  The  function*  of  the 
fibrw  <Miniux  lV»m  the  ^ympatlieiic  system  hare  not  yet  been  clearly  nccei^ 
tained;  but  (here  h  evidence  that  aonie  of  the  fibres  coming  from  the 
thoracic    gauf^Ua  ore  vaaoinoLor  (c )Ustrict»r)   fibrei  for   the    |Hilinoniry 

TCM^Io. 

Thk  Mr.'-nANK^  or  Pi'luoxakv   Rrhpiration. 

$  335.  The  lungK  ure  placed,  in  a  ittnte  which  i«  always  one  of  diliteniion, 
H<>mcltincii  grrutcr,  )i(>mi'tiincj>  K'ju,  in  tho  nir-tjght  thomx,  the  cHvity  ol 
which  they,  logcther  with  the  hwirl,  great  bloodvcMcU,  and  olher  organ*, 
«ompteI«Iy  fill.  By  the  coiitraclioii  of  cerlain  niu»cl«  tli«  cavilv  of  tlte 
Uiorax  is  enlarged.  Thr  lungs  must  tiillow  this  enlnrgcnie.ut  and  be  ihem- 
tclves  enlarged,  otherwise  tho  pleural  cavities  would  be  enlarged ;  hut  this  U 
impossible  sd  long  us  the  walls  are  intact.  Tho  enlargement  of  the  lung 
CKUsiaU  cbielly  in  an  enlargement  or  expansion  of  the  pulmonary  alvmli,  the 
air  in  which  beeumes  by  the  expansion  rarilied.  That  is  to  say.  tlie  piware 
of  the  air  ivithin  the  lungdi  becomes  leaa  than  that  of  the  air  outside  tne  body, 
and  thi»  difference  of  prei»ure  catiaw  a  ruith  »f  air  ihrougli  the  tnicliea  into 
the  lung*  until  an  eriuilibrium  of  i>rei»4ure  in  entahliubed  between  the  air 
Hiiiidu  iht!  hing!<  and  that  uuiaiile.  This  conxlituti^s  inapiralion.  llp<m  iJie 
Tvlaxalion  uf  lliv  inspiratory  museic  i  the  luuNclia  whuM  iMntractiviu  have 
abmii  Ihe  thoracic  cxpaosioii),  the  elaitticity  of  the  lungs  and  ckeat-wftlk 
aidnl  ]NTh»ps  tn  lonio  extent  by  thr  coJitractiiui  of  certain  muwiea,  eauMa 
tli<>  clK^t  to  return  to  its  original  tiw:  in  coQM^ucooe  of  ihiH  the  prenura 
within  Ihe  lungs  becomes  greater  than  that  outudc,  nnd  thux  uir  rushw  out 
of  the  Iracben  until  equilibrium  is  once  more  established.  Thi.t  ooiwlitntca 
expiration  ;  the  inspiratorT  and  expiratory  net  together  forming  a  rotpira- 
tioo.  The  fresh  air  introduced  into  the  upper  part  of  the  pulmonnry  |>as- 
nges  by  the  inspiratory  movement  contains  morv  oxygen  and  less  carlionic 
acid  than  the  old  air  previously  present  in  the  lungs.  By  difiuaion  the  new 
or  tidal  air,  ss  it  ia  frequently  called,  gives  up  its  oxygen  to.  and  tnkcs  ear> 
lxM)ie  acid  fnuu,  the  oiil  or  /'talionai-i/  air,  as  it  has  been  called,  and  ihoi 
when  it  leav«e  the  ehetil  in  expiration  has  bc«n  ihe  meaux  of  both  iutro' 
ducing  oxvgeii  into  the  chest  and  uf  removing  carbonic  scid  from  it.  In 
tills  way,  uy  the  ebb  and  fiow  of  the  tidal  air,  and  by  dilfusion  betweeo  it 
and  the  Malioiuu-y  air,  the  whule  air  in  the  luugs  ia  heiug  constantlj 
rencw»l  thM^i^h  llie  allrniate  cxpnuiieu  and  eontniotiomi  uf  tM  cbcst. 

g  326.  I»  iinlinary  ix^pinilixn  ihc  exfiannon  of  the  ch«>t  never  reaebes 
lis  maximum  ;  by  OMni  funibli;  munonlar  eoulrar'lioii,  by  what  is  ealled 
laboml  inspiration,  an  additional  thuracie  vxiuuiBiun  c»n  tie  bruugbt  about. 


THE    M  KCIIANICS   OK    PULMONAHY    K£«fIRATIOX. 


■ladlog  Ut  Mt  iiiruob  of  n  rertnin  additinnil  iguanlilv  of  nir  licforc  eqiiill- 

bMB  »  fstBhltalteil.     Tlii§  atlilUiunnl  (lUHiititv  ix  oncn  npulten  uf  at  rom- 

ptm*%lal  dir.     in  the  mtie  way  iu  ordlnarr  res^irntion  th«  <;»Dtractioii  of 

Urn  ebnl  mter  rrnrhia  ils  maxiaiun).    By  nlliiiff  into  \ne  a^lditioDsl  mtnctee 

Va  ktntrd  rKpirmiion  an  uddmonal  uuantityor  air,  Ibe  eo-cnlled  reeenv  or 

'^plemmtal  Htr  ni«y  l>r  ilriveu  mil.     But  even  after  the  nnwl  fi>rHb)e  esfijr- 

•tMO,  ■  cnimtdKrabft!  i|uuility  uf  air,  llie  rfilthial  air,  etil)  remains  in  Ibe 

'tngt    Tbr  nniunil  i-riudiiioii  of  the  liiiig*  in  itie  chttt  in  tii  furt  oue  of  |iarliul 

^■McBiion.    TW  i^lnKiii-  ]iiiliuonar^'  timie  ia  itlwayii  (o  a  cerutiri  extent  on 

*^  mtnteh;  ii  i*  iilviirN, to  lit  «j>cHlc,*iriving  to  |tull  aauuder  the  pulmonary 

ftott)  ib«  [lariMAl  pleura ;  but  thin  it  mnnm  <\i<,  Iieeaiife  the  air  can  iiave  no 

*oc«ri«  i»  tb«  pleural  caviiy.     Wbfo.  Iiowcvi-r,  tJie  clie«t  ceoKtt  ci  lie  air- 

^Htfkt,  abwi  by  a  piinolnrc  of  lb<^  cbnit-wul!  or  <tiniihni)tra  air  \i  freirly 

^^BB'Bihofd  into  tlitt  piriiriil  •'hanihcr,  the  cliinlicity  of  tlif  luii^  ptillii  lU« 

P*"! viiKianr  a«ny  from  tlwt  mrirtal   jilcuru  and   iln-  limgs  (wtlBjw-i.  driving 

?*«*.  by  tbe  Kio'l[iii>e  n  c»miiiiTiib!tt  iiiiiiniity  of  iho  rmiiliinl  air.    Even  llirn. 

^**^<«r.  the  lunn  are  nol  compMfly  emptied,  mnn'  air  niill  remaining  in 

^^^in ;  Uiis  is  pn>tiably  air  tmprimnod  i»  tht?  infiindilitilii  liy  collamo  of  the 

W*  K>atii'%o\n.  whicb,  as  ne  bare  trva.  have  flnccid  and  nut  ngid  walk     If  in 

R^  %Tiii|[  aninal  the  premurc  of  tttc  atmoaphcrr  continue  to  have  access  (o 

j^^^Mttideof  a  Inng,  Uw  air  thus  iinprisotit<)  if  gradually  abiorbe<l  and  Ui« 

— ^^  *g  beootnes  solid.    TIk-  eanto  result  may  occur  fruio  tho  pressure  of  fluid 

r«fliaUied  in  the  pleural  vavity. 
^  It  need  liantly  be  added  that  irbeii  the  pleura  is  punctured  and  air  can 
^B^in  Jnr  admitlanoe  from  the  exterior  in  the  pleural  chamber,  ttince  llie 
I  to  the  entrance  of  ihe  air  into  llie  pleura)  chamber  is  far  leas  than 
radatanoe  to  the  entrance  into  the  luuga.  the  cd^t  if  the  respiratory 
■mnonts  u  uimply  to  drive  air  in  and  out  of  that  chamber,  instead  of  in 
out  uf  ihr  lung.  There  'u  in  cunwciuL-nfi.'  no  ren<;u'al  uf  the  air  within 
I  Inogs  under  tboae  nrruraiiiiiiii.'i=i.  If  there  Ih^  a  suOicicut  ubMacle  to  the 
^mtrwocB  of  nir  into  the  pK-ural  tharolier,  micb  as  a,  fold  of  tissue  blocking 
vp  lite  opMung.  the  expannion  of  the  cb<sl  may  Ktilt  lead  to  a  ilineolinn  of 
the  luo]^  ana  in  this  way  in  iu>nK-  cast-*  ixinmin-  of  the  chest  walU  hn»  not 
•eriously  laterfiifcil  oilh  m>|iirnti-m.  Tin-  parietal  and  pulmonary  pleura 
ar«.  Id  Domwl  rirtuniBtances,  separated  hy  a  very  thin  layer  only  of  Huid, 
•0  that  we  may.  perhaps,  speak  of  them  as  being  iu  a  state  of"  adhesion," 

taud)  as  obtains  bolneen  two  wet  mcmbranM  sii  peri  in  pitted.  And  it  hashe«n 
aOQBSted  Ihsi  lhi»  adheeion,  having  M  be  OTercome  before  the  two  surfaces 
out  separate,  assists  in  preventing  the  entrance  of  air  into  the  pleural  cavitv 
after  puncture  of  the  thorax;  but  it  has  nol  been  clearly  shown  that  this  is 

I  really  of  iiojiurtance  in  the  matter. 
$K7.  Before  birib  the  lungs  contain  no  air;  they  are  in  tke  condition 
raJlol  atrl/et-ilif.  The  walla  (^  the  alveoli,  the  ^litbolial  lining  of  which  is 
a]  thai  time  well  developed,  consisting  of  distinctly  itcticleated  cells  with 
granular  rell  subMaace,  are  in  eoniact.  the  caviiy  of  the  ali-i^ilus  not  having 
■a  vet  ninie  into  extMence;  tho  wslln  nf  the  bnmchi'iln  are  similarly  iu  a 
n>lla|iaMd  cumlitiou,  with  their  nalU  (nuching  ;  the  ni»re  rigid  brimchia,  like 
ibe  trMchmi.  puMwa*  some  amonnl  of  lumen  whicb,  howi^vrr.  in  uci^iipicd  by 
6uid.  When  the  chest  cximudit  with  the  first  breath  taken,  the  pr^iuure  of 
the  Sn«pi(«d  air  has  li>  ovcrottiuc  the  "  adhesion."  obtaining  bvtwetn  the  walls 
of  iba  alvcoili  tbu<  in  ooiitacl  with  eaeb  other  and  aUo  thoae  of  the  hroncbiolea. 
Tho  toKv  e|>ent  in  thus  uuaning  out  and  unfolding,  so  to  speak,  the  alveoli 
simI  bnmrhioles  is  conMdurnbTe,  and  in  the  expiration  sucoreiling  ihe  first 
in»|iiration  most  of  tliv  air  thus  iutroiluce<l  remains,  tbo  force  exerted  br  tlM 
CM»t  in  roturuing  to  its  previous  dimen^tnns  after  the  brcathtng  in,  ana  tbo 


1 


440 


R£SI'tRATIOS*. 


«)«slir  nclioD  ol'  ihe  nlT«oli  beioK  inBufficient  to  bring  ili«  walls  of  i)ie  aktoli 
agaJD  into  coiilacU  Succeeding;  brcalba  unfold  lli«  lu»},'i  more  and  more, 
until  all  the  alveoli  ami  broiicliioles  are  opened  ii]>,  and  (h«ii  lli«  whoki  force 
Df  the  expiruiory  aci  is  directeii  t»>  driving  out  the  i>revk>*i!J_v  inspired  »ir. 

It  in  tKit.  Iiowever.  iiDtil  douie  time  after  birth  that  the  luu;;*  pft*i  into  that 
flirther  rlisteuded  slate  of  wliirh  we  ajHike  above.  In  a  iiewly  brirti  sniuial 
tliere  ii  no  negative  {ireiaure  obtaining  in  the  )ileural  caviiits;  the  lun^ 
vbeu  nt  rast  ore  not  na  iW  airtii.ch.  aJid  njieninij  the  ihorax  tint*  not  lead  to 
coltajxH-  of  ilie  luDgv.  Tlie  niuie  of  thiuga  obtaiuiDz  lait-r  on  i»  «MnblijJ>ed. 
not  nt  once,  but  grnilually,  and  in  apjnrently  brouf^t  about  br  itie  tbtms 

firnwing  more  rnpidly,  and  no  bvi'oiuinK  relaltvrly  moru  raniidnuK  than  tlte 
ilD^.  The  <}ii>l<-uti»ii  of  the  liiiign  in  iWoiIolt  may  l>C  tamiliiirly  di9<!rib«l 
M  iK'ing  diK'  t<i  the  chcTil  lit'ing  loo  larei-  for  the  Inun, 

S  328,  In  mnn  the  iimunre  ext-rud  by  llm  claiticjlr  nf  iho  lung*  atoiM 
ani'iiint«  lo  about  5  or  7  mm.  uf  mimrury.  Thi*  i»  wtimati.'d  bv  tying  • 
mnnonictcr  into  the  windpipe  of  n  dnd  Mibject  and  uWrviug  ihv  Hm  of 
mercury  wbith  takes  plac*  when  thr  chc»t-vnill»  an  punctun-d.  If  wo  took 
7.6  mm.  as  the  prnmrc  thin  uonld  be  just  ^ in  of  tho  pressure  of  the  atmo*- 
pbere.  If  the  che«C  be  forcibly  di»tcndc<l  beforehand,  a  much  larger  riM  of 
the  mercury  is  observed,  aniuuntiiig  in  the  case  of  a  distent  ion  corresponding 
to  a  very  forcible  iuBpiration  to  IJU  mm.  In  the  liviiif;  body  lliiii  ntecbanical 
elastic  t'orce  of  the  Iunf>i  may  be  nwtsled  by  the  contraction  of  ibe  plain 
iiiUBCulur  fibres  of  the  bronchi ;  the  prej^iire,  however,  which  can  be  <>xerl0il 
by  th««e  probably  doett  not  exceed  1  or  'i  mm, 

Wlien  a  manometer  is  inlroduced  into  a  lateral  opening  of  tlie  windpipe  of 
an  iiniumt.  ihe  mercury  will  fall,  indicating;  a  Degative  pr(^iin.-.nH  it  i:'  called, 
duriac  iu»|iiniti'in,  and  riiu-.  indicating  a  positive  prcmuri^.durini:  aspiration, 
both  fall  anil  Hm?  l)i.-ing  Blight  luid  varying  ai-curding  to  th«  mnlom  with 
with  which  tlic  air  pnMO  in  and  <iiil  of  ihn  ch<»l.  AVhwi  a  mAnon>M«r  i» 
filled  with  uir-tight  cliwure  into  tt»r  nvnith,  or  Wttcr,  in  order  t'l  NVoi<l  tbo 
suction- act  ion  of  the  mouth,  into  one  mtilril,  the  other  nostril  and  thu  mouth 
being  closed,  and  eR(>r(»  of  in»pimtion  ami  cxf>initi<m  are  made.tbr  mereury 
falls  or  undergoes  negativt*  prowurc  with  in^fpirntinn.  and  Hm*  or  undcrgoea 
positive  preHure  during  expirnttun.  It  Iiab  hmn  found  in  this  iray  that 
the  negative  pressure  of  a  strung  iiispinitory  effon  rasy  vary  frDOi  30  to 
74  iDin.,  and  the  positive  prcBsure  of  a  strong  expiration  fW>n)  63  to 
100  mm. 

The  total  amount  of  air  wliicb  can  be  given  out  by  the  moat  fhroibte 
expiration  folIdwinK  upon  a  most  forcible  inspiration,  that  is,  the  sum  of  the 
eumplomenlal.  lidal,  and  rteerve  aire,  has  been  called  the  "  vital  capacity;" 
"rxlreme  ililliTential  capacity"  is  a  better  phrase.  It  may  )>e  measured  by 
a  molilication  of  a  gnA-inetor  called  a  t/iiromrier ;  and  though  it  variea 
largely,  the  average  may  be  put  down  ut  :iOUO-400i)  cc  ('iOU  to  2A0  cubic 
iucnes). 

Of  tlic  whole  n>oiL#ure  of  vitid  rapacily,  about  500  c.c-  (.10  cuhi*  [nchni 
may  be  put  down  ai*  the  avemgu  nniouni  uf  tidal  air,  the  reoiaimJcr  boinp 
nearly  C4|unlly  divided  Iwlwceii  thu  coniplemcntal  and  rfsurvi-  air*.     Tbo 

Juaniilv  Icll  in  the  lungs  aflcr  the  dccjieal  expiration  uinoutil*  to  about 
400  or  'iOUO  cc. 

Slice  tbo  respiratory  movemcnta  are  •»  MMily  nflccled  bv  vRrion*  drcumslaoccs, 
tkt  aimi'le  fact  "f  aurntion  \mng  directed  to  the  breatnlnfc  beiag  latHcleat  to 
eatiM  luodificalioDH  both  uf  the  rnte  and  deplli  of  ihe  respiration,  it  Mcomaa  rtty 
dilBcult  (o  llx  itie  volume  of  an  atersge  bmth,  Thun  varloua  authors  faav«  givM 
ligMm  nrying  from  M  c.c  to  'ff'i  c.c.  Tho  statement  made  ubove  i>  the  mean  of 
oStrrration*  varying  frem  1"7  lo  itSW  cc. 


THR    lIRCUAyiCS  or  PtTLKOyART    RKSPITt ATlOy.       411 


I 

I 

I 
I 


ii  3M.  Urnphie  monU  of  rupiratory  moivmrji/^.  Tlidw  iii«y  Iw  fll)Uin<i) 
in  uan,v  various  wajra. 

The  limplMt,  readirat,  Kn<)  pMbapi  th«  inoHt  generally  tHeful  meili'ii]  U  thnl  of 
recnniinjc  ihr  movrmonu  iiT  the  (oliimn  of  air.  ThU  inajr  be  effected  hy  iotro- 
dncins  a  T'l'i<'(-'*^  >"*'*  tliv  trndira.  one  cmw-piwo  boinx  let  open  and  llio  otiior 
coBuocinl  witli  ■  Jlur^y'i  taiubour  or  witli  n  ri'ceivor.  which  in  turn  in  ci^imi-ctrd 
wilb  a  UuilKiur  fsee  Fig.  73  and  Fig.  liSi.  Tlie  inoveiui-utH  of  tbe  column  of  nir 
in  tbe  Iracbe*  are  traoKmiUed  to  lli«  taicboiir.  the  cnnsequeDt  expinHionH  and 
and  eoniriu-iions  of  wlik-b  urn  Iraiumitttd  to  lb*  recording  drum  hy  meant  of  a 
tvrtt  rmtini!  on  it. 

If.  a  receiver  bc^ng  UMcl,  tbe  ofien  end  of  th«  H  be  cloaed.  tbe  nnimni  lir<-Hib<» 
into  aiid  out  of  (be  receiver,  and  tlie  inoretnentn  of  tbe  tambour  are  gmllj  in- 
creNKcd.  TIih  h»'>  (b«  diM'Ivnntaga  (hat  the  air  in  the  receiver  *onn  beoomea 
unlit  (oi  further  reapiraiion.  \  aimilnr  incr*<w«  of  the  mnremeuta  of  tbe  levar 
nf  Ibe  tainbour  may  be  olitained  by  coancctine  a  pie.iv  of  India-rubber  tnbitiit  to 
the  open  end  of  tbe  h*  -  I'.v  increaiilnK  tbe  lenglb  of  thb  lube,  or  sligblly  e»n- 
•IrictinK  it,  tlie  niovemenia  of  the  lever  niav  be  increased  triiboul  very  seriously 
intrtfrrinE  vilb  the  breathing  of  tbe  Btiimal. 

In  nn'ither  method  the  mnvcmeocii  of  the  cbnt  ar«  recorded.  When  ii  mnall 
Aiilinul.  Micb  an  a  rabbit,  in  iii«l,  (ho  wbolv  animal  may  be  pUtvd  in  un  air-tight 
box.  breathing  bvlng  earried  on  bv  tne«n«  of  a  lube  imterled  into  the  traobeft  and 
carried  (brongli  an  air-tiitbt  orifice  in  the  wall  of  the  box.  Ity  anothier  orlBco 
ai»<(  lubo  tbe  air  in  tbe  bm  i*  brought  into  connection  with  a  tambour,  which 
aeootdingly  regiKlm  the  chnnKcs  '>f  prewute  in  the  air  nf  the  box  produced  by 
the  iiwveneDta  of  tiic  che*l  (and  body),  and  thu»  indirectly  tbe  movemenia  of 
Uu>  chtet.  In  man  and  larger  anim^a  tbe  changes  In  the  girth  of  the  cbe«l  may 
be  convenlraily  recorded  by  mean*  of  Maray'a  paeunioKTii|!b.  Thi«  uoneiKt*  of  a 
hollow  elantie  cylinder,  nr  a  cylinder  with  clastic  coda,  the  interior  of  which  U 
connected  with  a  tnmlxiur.     Br  lucan*  of  a  «irap  attached  to  each  end  of  tbe 

3 Under  the  iniitruQicnt  can  be  Luekled  round  the  uhesl  like  a  girdle.  When  lb« 
M  expand",  tbe  ends  of  the  cylinder  are  pulli-it  out.  and  Ihe  air  within  the 
chamber  rarefied ;  in  coniic<iiieni'c  the  Icrcr  of  the  lamlKiur  connected  with  ita 
interior  ii  deprewcl ;  ■.imTerHely,  when  Ibe  eheiit  oontrnctn,  the  Icrcr  i*  elevated. 
The  pneamatigrui-b  of  Flrk  i*  winiewliat  alnillar.  Or  cbangai  in  one  or  other 
diameter  of  the  cbcst  may  1>e  recorded  by  what  may  be  called  the  "  calllpeta " 
method,  tm  io  the  recording  Htethooielor  nf  Itnrdnn  ^Anderson.  Thi*  conaUl*  of 
a  rrctiinitolar  frumcwork  MiDilracted  of  two  ri^id  ]iiiriillct  ban  joined  nt  riKhl 
angln  to  a  cnitu  pirre.  The  free  eodii  of  tbe  barn,  tbn  dintanee  betwueu  which 
can  be  regulated  at  p1ea*nre.  an-  armed,  the  one  with  ■  lambour,  Ihe  other  aimply 
with  an  tvory  button.  The  tuml-our  bwara  on  the  metal  plate  of  lla  meonbraa* 
(w'.  Fig.  73^.  a  i>maU  ivory  button  in  place  of  the  lever.  When  il  i*  desired  to 
record  the  rbnncM  occurring  in  any  dianietvr  of  the  cbnl,  r.  •;,,  an  antero-piw- 
tertor  diameter  from  a  p»int  in  the  aternuni  to  n  pidnt  In  the  back,  tbe  inatrnnteot 
la  made  to  encircle  the  cheat  somewhat  after  the  faahion  uf  a  puir  of  oHlll^cn.  the 
ivory  button  at  one  free  end  b^g  placed  on  the  «pine  of  a  vertebra  behind  and 
tbe  tambour  at  (he  'tthct  on  lh«  sternum  in  front  in  the  line  of  the  diameter  which 
b  beine  alndicd.  The  dtitance  between  Ihe  free  eniN  of  the  inatrutneut  being 
car«fulTva)Uuit>-dM>thut  the  bviilori  of  the  tambour  ptetitw  lightly  00  the  oti-rnuiii. 
any  variation*  in  tbe  Iciivlb  of  the  diameter  io  iguottion  will,  aince  the  fraiuewoik 
of  the  lanibout  in  immobile,  give  fine  to  variation*  of  preacure  within  Ibe  tam- 
buur.  Theao  vnrintinnanf  tlu:  "  reociving"  tambour,  as  it  !■  called,  are  cnnreycd 
by  a  lleiible  tube  containing  air  to  a  aecuod  or  "recording"  tambour,  the  lever 
of  »bi<.'b  record*  the  Tariatlona  on  a  travelling  surface.  For  Ihe  purpoae  of  meas- 
uring the  extent  of  the  moveinetitM  iIk  inHiriiroeot  miMt  be  experimentally  grad- 
uat*<l.     <)tbcr  form*  of  ciillipem  may,  uf  roun«,  bo  need. 

By  Htill  another  method  the  variati»n»  in  intra- thoracic  preuure.  by  meaim  of 
which  Ihe  movementi  of  thr  cheat  wulU  proiluce  the  movement  of  air  in  tlie 
lungs,  may  be  retorileil.  Thl«  mav  be  eTeried  by  introducing  carefully.  Io  the 
tolal  excJtmion  of  air,  inioa  pleural  cavity  or  into  the  pcricHrilial  cavity,  a  canulu 
connected  by  a  rigid  luW  with  a  manometer.  Wilb  each  inapiration  a  nqratlre 
preasnre,  or  mihrr  an  increaae  of  the  exiating  negative  ixcHure,  in  produced,  ibe 
meroiry,  or  nuiil,  In  the  manometer  reluming  at  Mcfa  expiration.     An  easier 


THK    VICCHA^*tCfi   OF   IT  I.MO.VART    KESn  R  AT1I}:C  .       448 


I 


nielbod  o(  neotAiof  ibia  iiitrH-iliorHcic  tir««iaui«  is  t<>  inlroituc«  Into  Ibe  i»oi>Iuj;u« 
aDclM«i««»iiiitl  (lUmtlai-Ui  Ihc  cnrduc  tound,  Fig.  73)  connei:t«d  withaunbour. 
TIlC  <BIOpbBf;iit  within  llin  tbutnx,  tikr  Ilitr  liriitt  .inci  gtr-M  vn>vU,  a*  w(i  nhall  tier, 
UafleciM  iu«'i.-ll  on  till'  luiigB  tiy  the  THtUlii>n*  of  intra -tlKinidi-  pmuure  bmughl 
alxiut  by  tlit^  reKpirutory  [novMrenu. 

In  yet  itnolUor  nieibnd  the  morfineata  of  the  dUphrnj;!!)  whicli.  M  we  shall 
■M,  Mrrre  >«  iho  prime  affrnt  in  bringinj;;  hWiI  iHp  wlnrgcinpnl  of  lh»  thomcic 
cnvity  att  recorded.  Thi*  rony  be  lione  by  imwrtiiij!.  lliri>U)cb  an  incisiuii  iii  the 
nlidocalusl  wall,  «  flnt  claatio  b«(  tie(i>e«ii  (be  diapbragin  and  abilnminal  organ*. 
Wbea  )a  Inaplniion  ibe  diaphragm  dcaceoda,  itvxarln  oa  the  bag  a  preaenre 
which,  bv  meaiM  of  a  lube,  may  be  comrauoicated  to  a  umbour.  Or  a  tiwdl* 
mar  bo  (IirD«l  through  th«  clitt  wall  «o  an  Ui  rvsit  upon  or  imntfix  the  diA]>hragiii. 
anil  tbe  hMil  of  lhi>  nt^edlc  iiulaide  ibe  b'ldy  connected  b;r  a  tbri-ud  or  othern'iM 
with  a  lerer;  e*cb  u|iwitid  Kiid  downward  ti'itvement  of  the  bead  r>f  the  ne«dle, 
GorrespondlDg  to  the  downward  and  ujiwRrd  DioTemenli  vf  the  diaphragm.  U 
r«Kiat«red  by  the  leTcr. 

VarioM  inodificationii  of  llinie  Mivcrul  metboda  have  been  adopted  by  varioiu 
obtierv«r».  They  hII.  however,  leave  much  to  be  devirad.  A  very  ingenlout 
Dielhod  of  register! nff  tbe  conlruLliuaB  of  the  dUpbra(;in  ban  recently  been  iii- 
tmdiKNs].  In  the  rabbit  two  allmofmLixcular  Abree  forming  |>nri  of  the  <liii|ibrjiK"i. 
one  on  each  »idc  of  the  eniiiibnn  cartilajtc,  are  »o  diapiMcd  and  p'la'CH*  nuch 
attaclimenU  that  one  or  both  of  them  may  be  imlated  without  injutr  to  either 
nerves  or  bloodraaebi,  and  arranged  no  tlul  while  one  end  of  the  iilfp  u  wcurely 
fixed  to  (lie  cheat  wall  aa  a  fixed  poinl.  the  other  end  can  by  a  thread  be  brought 
10  bear  oo  a  lever.  Tlie  «!ip,  even  when  thus  arraoged.  apiwin  to  coiiirucl 
rhyllimEcally  in  complete  uaitan  witb  the  contrnctiottn  of  the  whole  reil  ot  the 
diaphragai ;  it  aefvee,  eo  to  apeak,  lu  u  mniplo  of  the  diaphriigm  :  itiid  heoci^  itfl 
contraclToua,  like  tboM  of  tti«  whole  diaphraijra,  muy  be  taken  ai  a  record  of 
rmpiratorr  ninvemvnU.  The  record  lias  to  be  correlated  for  rarialions  in  the 
pmiitloii  of  the  lixcd  point. 


Tautm  ae  TituRjtcii)  linrtiiiniBi  UovcKim  oiir*iiiu>  nv  nutMor  Mtaiv't 
■■HieHuulitrn. 

A  atalii  raaplnilMjr  t'lu*  ■•  n><ii|>rlvl  beiaotn  a  knil  n.  IntplnilMi. ditiluf  nUrli  ilie  lover 
it'oviMb. exwwdlng  l>uni«  lob. uid  eiiilnUuii  trum  Ho».  Tliv iiiidutalkai al  eafeMiuol  Iijr  Ibn 
hiMii'*  b»t 

^  330.  In  these  various  wap  curvce  are  obtained,  wbicb,  nhile  dtlTering 
to  deUil.  exhibit  the  mmo  g«iwnl  fcMlnree,  and  more  or  \vm  rescmbte  lh« 
curve  ahoii'ii  in  Vig.  Vi^i. 


Mv«adf4ecec4  lllMt>(^,  liwi'irJ  <•<  obxii  i9uu< cither  elCMd  or  twnUlly  otmnpcnl  at  flouiue 

\yf  Meant  or  the  tfwii  ^fninii  ^     From  lh<i  Jat  fintri^eilt  a  thlnl  |ilv<^  *'f  tutitiijc  if,  rnfuiivE<il  wilh  a 

Mfnr'*  laatioi*!  m  Im  1^  T3I,  (bo  leivr  ul  wblcb  I  wrlM  on  the  nonMliiR  fiiifaiY^    M  hen  Ihe 

inlB  li  |»  iiptB  Ills  uiIiibI  bcvatlM*  ftMly  IbKiiiali  Ibf*,  and  ttia  louvoinunti  In  Itir  *U  nf  0  aiHl 

mn>»|ucn<>T  In  ilie  uiaIbui  an  >nil>t.    i>n<balD|  Ih*  tikmpi:  lt>c  nolniftl  timilm  ouli  ilio  atr 

omuinttl  In  Uh  it.  ■iM  ihe  luovnseiil*  of  Ibe  lovor  ut  Uio  Mataar  booMno  aHWotneiillT  nnieh 

mi-ni  niarkM. 

B  DcloH  llio  lever  te  vcn  *  tuMll  Umemtrkfr  ■  CMtneeWd  iillh  an  clMtmmacnol.  Ihv  eunenl 

H        UinniRli  aliicb.  niminx  nntn*  lallory  It*  I  he  iHpb  i  ■lul  |r.  It  madoaml  tirokco  by  ■  clock -nntt  o« 

^B        lUMaiuiuc, 


144 


KKSHlBATItlX, 


Ab  itie  Rgttte  ahon;),  jiiRpifiiiion  begiuti  sumewhac  suddtmly  aud  itdviiiioc* 
rapidlr,  bc'iiig  follnweit  iinmeOtatel]^  by  fK|iirnltuit,  which  i.i  carrk-il  iiutu 
flnc  nk[iiilly,  but  iincrvrnnl  nmna  aixl  iiion-  ilimly.  ivueh  tiaiuet  lu  are  teta 
Ufluidly  t'LTiir  Iwlwetin  llif  cm!  of  cxiiinitiiiii  Atid  Hut  bi^niiing  uf  Entpin^ 
UoD.  In  tiorinnl  bmithiiig  liunlly  iiny  •iicti  {)uii»c  rsi*U,  Dut  in  cum  nhero 
tJie  rvupirutinn  twuoni*^  iiifruu(ii-nl.  pauHci'  of  confide  rah  1«  Ivagth  may  bo 
obiervuil.  An  wi;  fh»i\  wo  id  (ictail  noreafter,  ihc  (rvural  jmrW  nf  ihc  wlwlo 
•Ct  vary  iniioh.  iinilcT  varioii*  circiitu stance*,  in  rrUcion  lo  each  othct. 
SomotiniM  oxpirntion.  soiui?[imce  inapimtion  in  prolongs] ;  aai)  dthor  id- 
•ptralinn  tir  pxpiration  may  be  slow  iir  rapid  in  iu  development.  At  titno 
thv  dic»t  may  remain  for  a  wliile  at  thf-  height  of  inspiration,  thus  Risking 
a  pan»c  bctwenri  ioBpiratinn  and  expiration. 

In  what  may  be  ocin»dered  aa  normal  breathiu;;  the  rwnir«t(>rr  act  i»  re- 
pealed nboiii  seventeen  iiui«  a  miante.  the  duration  of  ttie  iuapirntion  u 
oomparvd  with  that  i>f  the  expiration  tand  *uch  pause  aa  may  exist)  being 
about  as  (en  tu  twelve;  but  the  rate  variet  very  largely,  und  in  this,  aa  in 
the  volume  of  each  bi-ealh.  it  is  very  difBcuU  to  lix  a  HaLiAfaclory  avera^. 
the  fii;ura  given  vurying  fruin  lwi.-iily  tii  thirtt^n  a  niiuule.  It  vorica 
aooordlag  to  at^e  and  »<>x.  It  i>>  iuflnrnciHl  by  ilxt  piwitiiui  of  the  body, 
bMDg  (|uicker  in  ulaiidiiig  than  in  lying,  anil  in  lying  than  in  titling. 
Huscular  exertiim  and  emolti.inal  onditiimi'  atlcct  it  dwplr.  In  lact,  almost 
•rerv  event  wbirh  ncciini  in  the  body  mav  inlliK-ncc  it.  Wc  ibnil  liavo  (o 
consider  in  detail  licrcaticr  the  nmuiicr  in  which  thc«c  inHuimmv  an.'^  broiiglit 
to  bear. 

Wliru  the  ordinary  resniratory  movemente  prove  insnlRcifint  to  ofTuct  tbe 
nec<THary  chiin|,'e«'  in  the  blood,  their  rhythm  and  character  l>c«ime  cliiuigwi. 
NiinunI  K^pi'nition  gives  place  to  labored  re«[iiraliou,  and  thia  in  turn  to 
dmjmiai,  nhich,  unless  Bonit-  resiorutive  event  oecur»,  urminatce  in  OfphtfTM, 
Tnme  abnornml  enuditiuii»  vre  Ahnll  tUiAy  more  fully  hereafter. 

Thr  Rftjiiraiory  Mavement*. 

S  331.  When  the  movenienls  of  the  chest  during  noriiud  breathing  are 
watched,  or  when  a  graphiL-  reconi  U  taken  by  one  or  other  of  the  methods 
just  dcAcribed,  it  in  seen  that  during  inspiration  an  enlargement  takes  place 
in  the  antcro-piMricrior  diameter,  the  Hternum  being  thrown  fltrward.  and  at 
tlw  nuDo  time  muvinj/  ujivrnnl.  The  lateral  width  of  the  cheat  is  also  in- 
oreaMd.  The  rertical  incrcaw  of  the  cavity  is  nut  so  obvious  fruni  the 
oub<idc.  though  when  tbemOTumentitof  th«^diai>hnigm  are  watched  by  meanf 
of  an  inserted  needle  or  otherwise.  It  is  okar  thut  the  u(>j>er  iturface  of  that 
organ  deeoeods  at  each  inspiration,  thr  nnU-Ti»r  wulU  of  the  abdomen  bulging 
out  at  the  Ktme  time.  In  the  female  human  imbjrct,  the  movement  of  the 
upper  {Hirt  <jf  the  cbe«t  is  viTV  conxpicuouK,  tliv  breiuit  rising  and  falling  with 
even'  respiration  ;  in  the  male,  however,  the  movemenlit  an-  n1mi»l  eniiixlv 
ODO&tcd  to  the  lower  part  of  the  chest.  In  labored  rt^piration  all  iiar(j>  of 
the  obeat  are  alternaiolv  expanded  and  contracted,  ihi^  brca«t  riiing  and 
falling  ID  well  in  the  male  na  in  the  female.  We  have  n<iw  to  c-ini*idur  thoM 
several  movements  in  );reater  detail,  and  to  study  tlie  means  by  which  they 
■re  carried  out. 

$  339.  Intpimtion.  TItere  are  two  chief  moans  by  which  the  chest  if 
enlarged  in  Donnnl  liisinration,  vix.,  the  d«neeiit  of  the  diaphragm  and  the 
filevaUim  uf  the  ribn.  The  former  causes  that  movement  in  the  lower  part  nf 
the  chest  aw)  alxlomrn  ki  clmracieriiilie  of  male  breathing,  which  is  hence 
called  diaphnigniiitic ;  tlw  latter  oauMH  the  movemeu  of  the  upper  diert 


TBE    UKCUAKICli  OV   PfLUOV  AHY    RKaPl  It  ATION  . 


446 


rlinrAclerittttc  of  t'vmiiln  bn^Uliing.  nhich  is  tMillfd  cimuI.  Thmc  Inro  innin 
Jmclun  are  umuOocI  by  \v>%  in){H>rUnl  untl  aulwitliitrr  <ivi.Mir«. 

Etl-ii  iu  the  female  human  »tibjccl,  tho  nhan.*  Uik«n  in  rcspiniti<m  li,v  the 
Hi«j>bnifm  is  no  imporliiDt  oik-,  in  the  miilo  the  (lisi>hrngm  must  tw  rcgmrtletl 
as  ihe  chief  rrapiraloTy  ai;eni,  and  in  gome  iiiiimnls  its  n«e,  for  this  piiq>08e, 
is  90  profuinent  that  the  movements  uf  the  ribs  may  in  norma)  hrealhin^  be 
aJuKMt  neglecled.  In  the  rahbiL  for  inMimce.  in  normal  breathing,  almost  nil 
ibe  Kepiratory  work  U  done  by  the  conlr ael ious  of  the  diajihra^'m. 

The  dcfloent  of  tbe  diaphra^fm  is  etit-L'tt^d  by  menus  of  the  (.-on traction  of 
its  m«»-ular  tibrea.  When  at  reel  the  dijiphragin  preaeuis  a  oiinvex  surisM 
U>  lli«  thorax  :  nht^ii  cuntrscted  it  beeomen  much  nailer,  Hiid  ill  euusequeitoe 
the  level  of  the  <^hi«t  floor  h  lowerod,  the  verttcle  diAm«ter  of  the  cliest  Heing 
pr»)M>n innately  ^nlarct^d.  In  d«ecendiii|{,  the  diapl>ri^;m  prtesea  on  th« 
alxloininAl  viaceru,  niiS  bo  canm  a  pn>j«ctii>n  of  tb«  flaocid  nbdotniital  whIIr. 
Fmiu  its  altachmNitx  to  th«  M«n)um  nod  the  fulve  rilu,  the  diaphracm,  while 
contracting,  nattirully  tttudit  to  piilt  the  Ktenium  and  the  ujiper  fiiiao  riba 
downward  ami  innnnl,  and  i)m!  tower  falae  rib*  upward  awl  inward,  toward 
the  lumliar  »{>iiH!.  In  normal  hreathine,  this  tt^ndency  prodiii^ea  liltl<!  elTecl, 
betu^  cnuDtvmclvd  by  th«  nrcom  puny  inn  general  c-ohuI  ctevatiou,  and  by 
cenain  sfiwial  muscles  (o  ha  nicnt!4)niil  prwcutly.  In  foroe'l  iDspirmtion, 
hi>w<^vt'r.  and  muocially  whvre  Iherv  w  any  olMtniction  to  the  entrance  of  air 
into  ihc  iLinn,  In*  lower  ribs  may  bo  f>  much  dniwii  in  by  iIm:  nmlractirm 
of  Ihi-  dinpnmgia,  tlial  the  girth  of  the  trunk  at  thi«  point  t«  ohvimisly 
(limiiijflhed. 

S  333.  The  «t«vatioo  of  ihe  ribs  it  a  murh  mort-  complex  m:tlier  than  the 
cloMent  of  the  diaphragm.  If  we  examine  any  one  rib.  Htich  lu  ihr  fillh.we 
find  ihat  while  it  n>ovea  freely  on  it  vertebral  aitioulati<m.  it  iucliiMi  wlien 


In  tbe  iMisilion  of  rxvt  in  nn  obUr|iie  dinn-tion  from  (he  tipine  to  the  sternum  ; 
hence  il  is  obvious  thai  whi-ti  the  rib  in  miiuid,  itx  xlornal  ntlachmeut  must 
uot  only  be  earricil  upward  but  aimi  thrown  forward.  [Fig.  PtO.J  The  rib 
uiay  in  bet  be  regardeil  a«  a  radiuy,  moving  on  the  vertebral  articulation  at 
n  centre,  and  causing  tbe  sternal  attachment  to  descnbe  an  arc  of  a  circle  in 
tbo  vertical  plane  of  the  body ;  as  the  rili  is  rvrnvtl  upward  from  an  oblique 
to  a  more  horizontal  pucilMn,  the  steninl  attachment  must  of  iMceMity  tie 
atrriml  <\irther  away  in  front  of  the  uplnc,  Since  all  tW  rib«  have  a  down- 
ward slflutiu);  direction,  they  must  all  tend,  when  raised  toward  the  hori- 
xontol   )>0!dti<m,   lo  thrust   the  slcnium    forward,  some  more  than    otliCffl 


Uti 


BESI'IBATIOS. 


according;  to  their  slope  nnU  length.  Tlie  claslidty  of  lli«  ttwniiini  and 
cu^isl  cikrtilages,  swivteti  hy  ihe  nriit^ulsiitiii  ill'  lh«  Uenium  to  tite  clxvk'le 
above,  pt-rniiUi  the  front  Aiirtiioe  of  the  cImuI  !•>  )>e  thu>  (hriwi  I^Twmnl  a* 
well  a*  upniird,  nheti  tlie  rttia  are  niJMH].  By  ihu  actiou,  llic  niilcni-|H)»' 
leriur  dmmeler  nf  tin-  cheat  is  i^iitnived. 

^iiicc  Uii!  ribit  fiinii  nrches  which  uietvaMi  iu  th«tr  iweep  u  ouc  prtkceeili 
fniDi  the  lii>l  ih)wnu'iiril  nn  tkr  at  Iciist  a*  the  seventh,  it !»  (<vi4luiit  that  when 
a  lower  rih  »iiih  iw  ihu  fiftli  is  uicvaicii  ai  as  t«)  occupy  «r  lo  imiiroach  tnwanl 
the  {Mfitigo  »f  the  one  above  it,  tli«  cheat  at  that  level  will  l>ec<tnir  widttr 
froDi  aiilo  t»  ridv,  in  projiortiuii  n»  tlip  liith  arch  i«  wider  than  tliv  fourtfa. 
Thus  (he  elevation  of  the  Hh  iricreii)>c8  not  only  the  an  toro- poster ivr  hiit  alao 
thir  tratiBver«e  dinmeler  uf  tho  chest.  Further,  on  account  of  the  rrai»l«nc« 
of  th«  sleniuni.  the  nagles  betwecti  the  HbH  and  ihoir  cartilages  are,  in  the 
elevation  of  tho  rihs,  somewhat  opened  out,  and  thus  al*o  tho  trai>BVcnM>  na 
well  as  the  an tero* posterior  diameter,  somewhat  increased.  Id  more  than 
one  war.  then,  the  elevalioa  of  the  ribs  enlarges  the  ilimenHions  of  the  chat. 

$  334.  The  ribs  are  raiwd  by  the  contraction  of  certain  muscles.  OrUma 
the  external  interci'v^talB  are  perhaps  the  most  important.  Kven  in  the  esae 
where  two  rihs,  tiuch  as  the  tifth  and  .'>ixth,  are  isulated  from  the  real  uf  the 
thoracic  caee,  by  sectiun  of  the  stnictiifi^  occupying  the  iuiercoetal  kp*obb 
above  and  below,  the  eontrui-'lion  of  the  external  iniercuolal  iduaclfl  of  the 
iiitertening  space  raises  the  two  rilis,  thus  bringing  thciu  toward  ttie  posilion 
in  which  the  librcs  of  the  ntuscle  have  the  sborie^^t  lenuth,  viz.,  the  buriiontal 
one.  Thiii  elevating  action  w.  in  the  entire  vhon,  furtner  bvored  by  the  fact 
that  die  firat  rih  is  le»s  mciveuMe  tbuu  the  decund,  and  sn  aflonU  a  oompan- 
lively  fixed  bate  for  the  action  of  the  niUHele>  between  the  two.  the  wcond  in 
turn  supporting  the  third,  ami  so  on,  while  the  Mcali-iii  aiuscles  i»  (ulditiou 
«rvc  to  render  fixed,  or  lu  raiw,  tli«  firel  two  rihs.  So  thai  in  normal  re^|i(ri>' 
tion,  the  act  may  probably  hi-  de»cril*ed  as  beginning  by  a  contrac-ti'in  uf  the 
ccaleiii.  The  HrM  two  rilis  being  thus  raised  or  at  lca«t  Sxi-d,  the  contnietioD 
of  the  leric:'  of  exlenud  intercostal  muscles  acts  at  n  great  disadvantage. 

While  the  elcvatin^f.  i.  e.,  inspiratiiry  action  of  tho  extcmid  intcro(«lals  is 
admitted  by  nearly  all  aiithon,  the  function  of  the  inlcrnnl  iiiterciMt«ls  hie 
heel)  much  disputed.  Home  ret,-ard  their  action  as  wholly  inspiratory  ;  ollieiv 
mainlaiu.  what  is  perhaps  the  more  commonly  adopted  view,  thai  while  thon 
pariB  of  them  which  lie  between  the  sternal  cartilages  act  like  the  external 
inlerc<talala  as  etevatora,  i.e.,  aa  inspiratory  in  fuuciion,  those  parL^  which 
lie  betnecu  the  oasenus  riba  act  as  depretuors,  >'.  e.,  as  expiratorv  in  function. 

In  llie  well-known  model  conststin);  of  two  rifpd  bars  [Fif;.  1^1]  repre- 
H-iiliu)!;  the  ribH,  moving  vertically  by  nieanu  of  their  articulations  with  an 
upri)|>lit  TL' p risen tiuj;  the  tipine.  and  connected  at  their  free  endd  by  a  piece 
tvprcM'ntinjf  the  Meniuni,  it  ii  undoubtedly  true  thai  sirtlched  ela^^lc  bauda 
Bltai'Jitfl  to  ihe  ban  in  such  a  way  as  to  represent  resjieclively  tlieesternal  and 
internal  iut^-rciMlaK  viir.,  itlopin^  iu  the  one  cii^  dowuwani  and  tiirwan),  an<l 
in  the  other  downwanl  and  Imckwatil.  do,  on  being  left  free  lo  coutract,  in 
ihe  former  oa>e  (-levate  and  in  ttie  latter  ileprcM  the  rib«.  t^eh  n  model, 
bowevor,  dotv  not  finirly  rvprwent  the  nattinU  onu<iitioiiit  of  the  rilio,  which 
■re  not  ■Iniight  and  rigid,  but  [leeuliarly  curved  and  of  varying  elasticity, 
enjiahle  moreover  of  rotation  <>n  their  nnn  nxes,  and  luiving  thi-ir  mowmenta 
dt'lcrmiii<-<I  bv  the  cluiriicleri  of  their  vertebral  artiriilation*.  The  nivchiui- 
icul  ei>ndilions  in  (art  "f  these  niuwlw  are  »o  complex,  that  a  dctluclton  of 
tlteir  actions  frcni  simple  mcehanicnl  principle*,  or  from  the  direction  of  the 
fibr4«,  must  be  exccolingly  <lilliciilt  iiud  dangerous.  Actual  cxpcrimcjits  on 
tl>e  eat  and  dog  teixl  Ut  show  that  in  ibcse  niiimalx  tlie  contntctioo  of  the 
internal  iuterouauUs,  tlong  their  whole  length,  take*  ptaoe,  in  pwut  of  tinw, 


TUK   HKCIIAMce  OV   1'Vl.UOSAKY    KtSl'I  RATION.       447 

vIltnMvlTiftilithKtortbedinpliraeRi.  ami  thuRafTord  nn  irgiiaMiiit  in  fiivor 
^  ihrw  niuEolcfi  lieiii);  expimlury  in  fiiriclinn, 

Sm    ill    inipurlancc    lu   the  cxtvniiil    intrn-ofltalH   omin   ihr   liivnlon* 

'■Qauram,  wbicli,  th»ii);li  »mall  iiiiiH.'le8,  arc  able,  Iroin  thv  tiviirnraa  ul'  iWir 

^■aacal  bu*rtti>tut  i<i  the  fulcrtiin,  lo  produc«  aiii«<]pnit>lt>  tiiovcnx-nt  of  ihp 

tsraial  coda  uf  the  ribd.     Tbe  exlernitl  iiiier<.'iw tali  and  llie  levatorc*  tiistanini 

*>  t  h  Uw  acaluii  iun,v  fatrlv  be  ta'id  lo  bu  i  he  elt-valora  of  the  ribs,  i.  c,  tbft 

■"-hiwrf  BaKlea  of  covul  iuipiraiioii  in  Durmiil  brc-«iliiug. 


Iff      f 


I 


I  »>rt«i.»'>  >W  lan.nnli^UUiiK  ihi  tlw  iKfllo*!  terr;  i  |i  ui4  vi  art  two  rutiUir  baiiilt, 
tviamttit  mpmittvlr  <>>r  viumoJ  mni  UiMful  iMdwaul  MuMte*.    Hacnni  a  r«pn>c»ia 
HflM la >  Msi*  of  rm     ir.  »'iw,  (htisixl  «aa4r*iu  ftcc  la  Kuitnel.  tl  it  •ibriuiK  ilui  In 
■oMMIn  III  itirvvai  Iriitih.  I1  uoiild  ■hiiid**  i<ariilnn  MladlNcno*-'     If.  ■>"••  IIh  I>i»I  w 
■  «■*  n<«  ii>  WOTP.  Ilir  (MiiDiw  niniM  laVv  pUr*  iif  iTlHit  «■  lecn  *l>m  r  ud  ■>  bniudv 
I     Tiniv.  In  ilUcmn  Ik  xtve  ftuo^lAfi  afv  ^l«]|*i^M>ii- 
TWMnaif  awl  ■  RT|MMmi  ib*  mIbiwI  ikiomoiai  iiiiui<l«.  iiiiidi.  tir  •»»ini^ilaa.*I':TMii  Ike 
fn*.   T)>*liui4>  a  kifl  I  fii«BcM  tlw  iiiuniBl  lii<iin.-ii«al*,  wblrli.  Irj  TniilmvUnit.  iktirrw  ihi>  rlln,] 

It  niuxt  be  ai]<led,  bow«v«r,  that  swue  oWnera  deny  that  eitber  act  of 
iii|rr«nataJ  hiiikcIo)  take  any  iiuporliint  |Nirt  ia  raUin^  ibo  ribe^  Tboy  hold 
■hat  tlM>  cbiff  if  uiii  lb«  only  une  uf  th«M.'  iiiiik-I<9  i*  by  tlM>ir  contnu:u<in  to 
rrwlrr  llic  intetxislat  «|>ncea  6na  ami  tbv  urbulv  lbi>rii<:if  oiigc  rigid,  so  tbat 
Ibo  Iboras  i*  luuved  lu  n  irbi>le<  by  ibe  other  mtiicb-e  mvntiontd,  and  tbe 
iattrcaMul  (pact*  do  m>l  give  way  during  tb<!  renfiinilnry  RiiivenicolB. 

Addhioiial  npuff  in  Ibe  Immvent*  diameter  i>  alfonlvd  probably  by  ibe 
ntalifMl  of  ibe  rib*  oii  an  uiili-n> -piiatcrior  nxiti;  but  ibis  awv«m«nt  is  quite 
Mibeidlary  and  iitiiiiipiirtaMl.  Wtion  iIh-  ebest  if  nl  nwt,  the  ritia  are  eonie- 
■  bat  ioclinnl  witb  itirir  lowvr  bonier*  •lirvetti]  iiiirnrd  as  irell  sa  downward. 
Wbru  ibey  an-  diiinn  up  br  ihc  nclion  of  the  iiilercoalal  inuH.'Iefl,  their 
lu«i>t  )i«nlcn  aro  evrrlctl.  Tliu*  their  lliil  f<i<li-i>  iirc  prctcnled  tu  the  iHoracie 
tavilr,  nbieh  t*  lbcr<>by  »ligbily  iiRn-iiMril  in  uiiltb. 

i  $39.  lioiaml  iutpimti'iu.  Wb«u  rwpiiatioD  beOMOcs  labored,  olher 
■Duarlt-*  ar«  bruuglit  into  pbiy.  The  evalciii  are  Btronf;ly  oonlmi.ted,  m  fta 
diatiDL-ily  to  mtae  or  at  leiiM  give  a  very  fixeil  HipiwK  to  ifie  first  and  aecmd 
rilw.  In  tbe  «anie  way  the  aerraiuD  {kwIicos  sopenor,  which  deaceud*  IVam 
Ibr  fiKiil  npiiie  ill  tbe  lower  cervical  aud  upper  dofanl  regiona  to  the  •eroDd, 
ihini,  fiiiinb.aml  llftb  riba.  by  ite  oontractioin  ruiaea  (hoae  ribo.  In  iaborc*! 
breailiiog  a  funt-lion  of  tbe  lower  lal«e  rilis.  not  very  iMXicenblp  in  riuy 
bn-aibii>([,  v»OHa  into  (>lay.  Tbey  are  deprew^i),  retraclol.  and  fixed,  thereby 
giviu);  in(-r*«Md  MipfH>rt  l»  the  diaphra^iu,  and  direclitig  the  irbolc  vnat^M 
of  ibat  UKiMjle  lo  the  verlieul  enlarpioieQt  of  ibe  cbc!)!.  Iti  ibijt  way  the 
torralu*  praticti*  inlrnor.  wbich  pnww  upward  from  ibe  iunilioir  aponouroaia 
bi  tb«-  laA  four  ril«,  by  dt-preaaliig  wd  lixiii);  tboM  rib*  l>ecoiii««  an  adjuvant 


J 


iuipiratorv  miiecle.     The  r|Uiiflratus  liinilioriint  nnd  [OW^^iamont  of  til* 
MDro- 111  tubal  i  ft  iniiy  have  n  Biniilnr  liiiietion. 

All  these  [tiutcles  mar  come  iuto  ovtioD  oven  in  brculhiiic  which,  tliOUgh 
deeper  Ihaii  ueual,  can  hardly  piirhape  be  call^  labored.  WheD,  however, 
thv  nei'd  for  greater  inspiratory  cITurle  bccome»  urgent,  all  the  muscles  vrhiob 
c«ii,  froru  any  fixed  point,  act  in  eidargiii^  the  cheei.  come  into  ]>lay.  Thus 
the  unua  and  shoulder  being  fixed,  the  terratuB  ma^nu-  paaung  fr^im  the 
acapnia  to  the  middle  of  the  lirtl  eight  or  niae  riba.  the  pectontlia  rniDor 
pnanns  from  the  coracoid  tii  the  front  nans  of  the  third,  fourth,  and  fiftb 
rib»,  the  pecioralis  major  uans^ng  from  trie  hunieru*  to  the  costal  cartilsj^w, 
from  the  MCRund  to  the  sixth,  and  that  j)urtion  of  tlie  latiatiroiia  dom  whidi 
pOMn  from  the  humcruii  tii  the  lii»t  thrc«  ribrf,  all  iiervc  to  elevalv  llic  riba 
and  thii:*  to  tulargc  llie  choit.  The  ^terno  luBNtoid  and  other  muiiclcs  pnMing 
from  the  nt^k  ui  the  xtcrniini,  nr<!  alno  railed  into  acliou.  In  fact,  every 
muscle  which  by  iw  ciintrnrlion  can  filhcr  cli^vnlv  the  ril»  or  contrihuiv  tu 
the  Hxetl  siipnorl  of  muscle-*  which  <l»  elevate  the  rilw.  nuch  an  the  Impczins, 
levator  iingiili  »ctipiilic.  and  rbomboidci  by  lixinc  the  ecnpiila.  may.  in  the 
iuapiniloi'V  cfliirl»  which  accompany  dyepmca,  be  oroiight  into  ptav- 

tl  33S.  Kipimliiii.  In  normiil  eti»y  breathing,  expiration  it  in  llie  main  a 
simide  effect  of  ctnslic  reaction.  By  the  inspiratory  eHori  the  elastic  tiaaue 
of  tlie  hiuj^s  is  put  on  the  stretch;  so  long  as  llie  inspiratory  muscles  coalinae 
ojotractinj*.  the  tissue  r«muin8  stretched  ;  but  directly  ibcae  muscles  relax, 
the  olsBliciiy  of  the  lungs  coiiim  into  play  and  drives  out  a  portion  of  the 
air  coiitaini.-d  in  them.  Similarly  the  ebiMic  sti-rnum  aud  ciiatal  curlilaga 
Mv  by  the  elevatiuu  of  the  ribs  put  ou  the  mreich ;  tbey  are  drivcji  into  a 
position  which  in  unnatural  to  them.  When  the  iuiercxfiul  aud  other  pI»- 
THtor  luuscien  cease  to  cootriu-l.  the  elasticitv  of  ibe  sternum  aud  eostal  car- 
tilagcs  causes  them  to  returu  to  their  previous  [)«»iti»n.  thus  dcpreasing  tbe 
ribs,  and  diminishing  the  dimeiiiions  of  the  ohest.  Whcdi  the  diafihraem 
de»cciidft,  in  imxhing  don  n  the  iibdoininni  vitwora,  it  pule  the  abdomioal  iralb 
on  the  strrtch ;  n]id  hence,  when  at  the  end  of  inspinttion  the  diaphnifrm 
relaxes,  the  abdoniinul  wnlls  return  to  their  plate,  and  by  pressiug  od  the 
abdominul  viMvrii,  puth  ihe  dinphrngm  u]>  again  into  its  position  uf  rat. 
Kxpiratiun  then  during  ciisy  brcnthing  is,  in  the  umin,  simple  elastic  reac- 
tiau  1  but  there  is  probubly  some,  though  pcKsibly  iu  mi«l  cases,  u  very  alight, 
expenditure  of  muscular  energy  to  bring  the  chest  more  rapidly  to  its  former 
condition.  This  is,  as  we  have  scen.supjHised  by  manv  to  l>e  nSurded  liy  the 
iulerniil  intcrcostnls  acting  as  deprewors  of  the  ribtt.  If  these  do  not  lua  in 
tfab  way,  we  may  suppow  that  the  elastic  return  of  ibi-  abdominal  walls  ii 
accoiupauied  and  assisted  by  a  ci>Dtmc(iuti  of  the  abdnmirinl  muA>clt9.  The 
tiiantfularis  slemi.  the  etlect  of  whose  cimtrnclion  is  to  pull  down  the  n<Mnl 
«artiGigc»,  may  alM  be  r^^arded  as  au  expirutury  mn-wlf. 

Wheu  expiration  becomes  labored,  the  abdominal  muncW  Ix-coine  im{>ort- 
ant  expiratort-  agents.  Br  prcfsing  on  tho  conti-nt>  of  the  abdomen,  they 
thrust  lliem  and  therefore  the  ilia|>bragm  iiImj  up  townr<)  the  chctt,  the  vertical 
diameter  of  which  is  therebv  lenteiied,  while  l>y  pulling  down  the  sternum 
and  the  mi^ldle  and  loner  rilis  they  lemcn  also  the  cavity  of  the  chest  in  its 
anicro  [HUteriiir  and  trantvcrw  diameter*.  They  are,  in  fact,  the  chief  PXpira- 
tv^  muscles,  though  ihey  are  dmibllem  aMisted  by  the  scrratus  posticus 
inferior  and  |iortions  of  the  tuicro-iumbalis,  since  when  the  diaphragm  is  not 
oontrscling,  tiM  deprimitm  of  the  lower  ribs  which  the  eontrsclinu  of  these 
miucles  causcD,  serves  only  to  narrow  the  chest.     As  expimiion   tiecon 

more  and  more  fiirced,  every  musclar  in  the  body  which  can  either  br  et   

tractiug  depress  the  ribs  or  press  <M  the  abdominal  vi^i-era,  or  utfonf  fixed 
support  to  muscles  having  thwe  actiaits,  is  calle-l  iuto  play. 


CITAK0B3   or  THE    AtB    I?:   RESriRATIO:?. 


449 


S  387.  /new/  and  hryngeat  rwpiration.  Tin;  (honieio  respiratory  mtvt- 
taenia  .ire  accorapuiwd  bv  s»ociat«d  respiruon-  itKivemenu  ul' otber  |MirU 
of  the  body,  mora  mrticularl;^'  of  lh«  tkoe  and  of  ilw  );lutiiit. 

In  Qomial  heallhy  respiration  tlie  current  of  air  whioli  pnium  in  and  out 
uf  ihe  lungs,  irareli^,  not  Ibniugh  the  moutb  but  through  thn  nose,  c)ii«f)y 
lhr(Wf(h  tbc  lu«-er  naxil  mealuii.  Th«  iiivoinj;  air,  by  exjxwiira  to  tliv  va>- 
cular  RincouM  membrane  of  tbe  narmn  ntiiF  winding;  naxiil  pmn^M,  i*  mora 
effldeuily  wnrmiHl  ihnii  tt  would  be  if  it  pMHtd  through  thr  mcnith  ;  and  at 
the  sattH'  tiiiK-  tb<-  inoiitli  i*  tliurcby  protected  from  the  dmiccatlng  cilf<.-ct  nf 
tbe  continual  inmnd  of  omipanttively  dry  nir. 

DuriDE  encli  iiupiralory  effort  (be  noelrilx  nr«  expanded,  probably  by  the 
artlmi  of  tbedilalores  naris,  and  thuD  the  eniranoe  of  air  fiicilitnted.  Tbe 
return  to  Ibeir  previoua  condition  during  espiratioo  is  etl^ct«d  by  the  elas- 
ticity of  the  niiMil  cartila|;e8.  assisted  perhaps  by  tbe  coniprewone  narie. 
Tbie  movenietit  of  the  noetrils,  perceptible  in  many  people  even  during  tr»tt- 
quil  breathiDg,  beromea  very  obvious  in  labored  respiration. 

When  ihe  mouth  L>  cloaed,  tbe  mil  palate  which  'a  held  somewhat  tense, 
ia  swayed  br  the  respiratory  current,  bitt  entirely  in  a  passive  manner,  and 
it  is  not  uuti)  llie  larynx  is  reached  by  ibe  inw^n^  air  that  any  active  move* 
menta  are  met  with.  When  the  laryiix  (the  details  of  wbidi  we  sliall  have 
to  deal  with  at  a  later  jnrt  of  thi«  work)  Is  examined  with  the  lurynvosoope, 
it  is  frei)uently  Men  that,  while  during  inipinilion  the  glottis  i«  widely  open, 
with  each  exnirataoD  tbe  arytenoid  curtilaKcH  apiircMcli  each  other  ho  m  to 
ttarniw  iIk*  gli>ttis,  th«  cartilflMS  of  8antorioi  projecting  iiiwnrd  at  the  aaine 
liine^  Tbuit,  ityiichronouR  with  t)u-  nvpiralory  oxpanawn  and  ouilniutioQ  of 
tbe  cben,  aiid  the  mpiratory  t^lrvaiion  and  aeprcwmt  of  llie  alw  niui,  tbtrt 
it  n  riiyiltmic  wMleniug  iinil  unrmwing  of  Ibe  glottic.  TJkv  tbe  movement* 
of  tbe  novtril,  this  rmpiraion'  action  of  the  glotti*  i*  much  more  evident  in 
labored  than  in  trvniinil  brr-jithing.  Indiwd,  in  the  latter  com-  it  i«  frequently 
abMDt.  The  manner  in  which  this  rhythmic  opening  and  narrowing  is 
«fleet«il  will  be  <loaorib«d  when  we  oome  to  study  the  production  of  the  voiO& 
Whether  there  exiala  •  rhythmic  contraction  aixl  expansion  of  the  trachea 
and  bronchial  posMgea,  eapecially  the  smaller  and  more  exclusively  niuDcular 
ooee,  eAected  by  m«aDfl  of  the  ]>lain  muscular  tissue  of  those  orj^ns  und 
ayuchroitous  with  the  respiratory  moTemenla  of  the  chest,  is  uncertain. 


Chamoeb  op  the  Air  ik  HrapiRATioK. 

^  398.  Dunns:  its  stay  in  tbe  IimgM.  or  rather  durini{  its  slay  in  the  bron- 
chial nanage^.  tlte  tidal  air  (by  me-ans  of  diffusion  chiefly)  elTects  ex^angea 
with  toe  stationary  air :  in  ooiueipienoe  the  expired  air  dilfera  from  inspired 
air  in  iieveral  important  paritculHn>. 

The  temperature  of  expired  air  in  variahlo,  but  under  ordinary  cin-um* 
atanow  Ik  higher  than  that  of  thn  intpirtrd  air.  At  an  avera;^  tempi:r.)ttire 
of  the  alni'Mphete.  for  iniilanee  at  about  20°  C,  the  tetD|){traturi<  of  expin-d  air 
ia,  in  iIh'  mnuih  'X\.9'.  ia  tbe  nim;  !U>.S°.  When  the  external  li-mpi-rAtiire  i» 
low,  thai  of  the  expired  air  xink*  tometvhat.  but  mH  lo  auy  );rent  (-■xlenl. 
thus  at  — K,.'!"  r.  it  i*  ■iit.H"  C.  Whcii  the  external  tempnrnl'ure  in  higli.  the 
expired  air  may  Iwcomo  cooler  than  tbe  ini*pirv«l.  lhu»  at  II.IP  it  hai  been 
roun<l  l<i  t>e  M.]",  The  expired  air  taka<  ilji  tem;>orJi)iin.i  from  that  of  tlia 
bixly,  that  is,  of  tbe  blo7<l,  and  thi«  as  we  sbnll  sec  later  on  while  generally 
hiffher  rosy,  at  timm.  be  lower  than  thai  of  tho  atni  >t|>hi>rc.  TTic  exact 
temiierature  of  the  expired  air  la  fact  depends  on  the  relative  temp^-ratumt 
of  tlie  blood  and  in4pife<l  air,  niid  on  tl>e  depth  and  rate  of  breathing.     Thv 


480 


RKHPIRATIUN. 


(i«]re*n. 

IlltrnvTII. 

ntrUiiilc  arlil 

80.91 

m\.s 

U.(M 

l(i.O»» 

7BIM7 

4.86 

cliiinK«  in  (emper8tur«  lakta  place  Dot  iu  ibc  luiit;a  but  fiMhenr 
and  (hiellv  iu  the  nuae  «ni]  pnarynx. 

^  338.  'rbe  expired  air  isluuded  with  a<|itctiu«  vapor.  Tlic  point  of  lain- 
ration  of  aiiy  gaa,  that  in,  Itio  utmost  <|iiHDiii}'  of  u'u(«r  vhirh  nny  givra 
volume  of  (tan  am  inkr  uji  a*  Htjui-oiin  va]i-ir,  vnntw  with  il>  ti;ni[)cniturT, 
beiiiK  higher  witli  (hi-  higlior  ttrmjicrulinv.  Fur  ila  ohii  (rnipvnitiirc  oxpiml 
air  it,  iicv>rdiiig  tu  tm>M  obvcrvon,  siiLuralfd  with  iiijiirous  vu|K>r.  The 
inoii«tiiri-,  liki'  the  wArmlh,  i»  impuited  n<>l  in  the  depths  of  th«  iung  but  iu 
th(>  iip|K:r  piuHogiv.  The  inspircn  nir  ae  it  pluses  into  Ihv  bronchia  is  already 
wilurnlri.l  with  moi^turu. 

§  340.  The  rxpimi  nir  conimn*  uboiit  4  ur  5  |>er  cent.  I«n  oxygen,  sud 
nbout  4  per  cent,  more  cnrbontc  iicid  ihnn  the  inspired  sir,  the  quautilv  of 
nitrogen  siifivring  but  little  chungr.    Thus 

Innnlrril  Rir  contains    . 
Espirvd  ■•       ■■ 

The  <|iiantily  of  nitrogen  in  the  expired  air  is  aonietiioes  found  to  bt 
sliebtly  greater  than,  as  in  tho  above  table,  but  aoroetiines  e<|ual  to,  and 
and  MDieiimt^  less  than,  l)mt  of  the  inspired  air. 

In  a  aiogle  bivath  llie  air  is  richer  in  carbunie  acid  (and  poorer  in  oxygen) 
at  the  end  than  at  the  beginniug  of  the  breath.  Hence,  tli«  loneer  the 
breath  ia  betd,  the  greater  the  (artificial}  paui^e  bi-iween  ianptration  and 
expiration,  the  higher  the  percentage  of  carbonic  acid  in  the  expiretl  air. 
Thus,  by  increatiing  the  interval  between  two  oxpiraiionH  to  100  Mojuds,  the 
percentage  may  lie  raised  to  7.5.  When  the  rale  of  breathing  reoiaiiu  the 
•ante,  by  incrvasing  the  depth  of  the  breathing  the  ]>ercciitage  of  carbonio 
acid  in  cneli  brentli  la  lowered,  but  the  total  (|tiaiitity  orcarbooic  acid 
expired  in  a  given  time  is  increased.  Similarly,  when  the  depth  of  breath 
r«n>ain>>  the  Enmo.  by  iiiickcning  the  Tuto  the  percvntage  of  carbonic  acid 
in  vnch  breath  is  lowered,  but  the  (luantity  expired  in  a  given  time  is 
in  created. 

Taking,  ns  we  have  done,  the  amount  of  tidal  air  pawing  in  and  out  ot 
the  chest  of  un  aveni^'e'  man  at  SOO  c.c,  lucb  a  pereuu  will  eX)>ire  ahdut 
2*2  c.c.  of  carbonic  acid  at  each  breath ;  this,  reckoning  the  rate  of  breath- 
ing at  17  a  minute,  would  give  over  oOU  litres  of  carbonic  aeid  for  tlie  dav'a 
production.  Actual  determiiiatiouf.  however,  give  a  mtlier  smaller  total 
tban  this  ;  ihua,  in  a  eeriee  of  experiments  of  which  we  shall  bave  to  «{M>nk 
hereafler.  the  total  daily  excretion  of  carbonic  ncid  in  an  average  man  «u 
found  to  be  SOO  grms,,  >'.  r..  rather  more  ihnn  4U0  Htree  (40(}),  containing 
218.1  grmft.  carbon  and  .581.^  grme.  oxygen,  the  oxygen  which  actually  dis- 
appeared from  the  inspired  air  at  the  aame  twing  about  "00  gniu.  Thia 
amount,  it  *huuld  tie  said,  represents,  owing  to  the  manner  in  which  ilit 
experiment  wm  coDdiicted,  the  gaaa  given  out  and  tukeu  in,  not  by  the 
lungs  onlv,  hut  by  tlie  whole  body ;  but  the  amount  of  carlionic  acid  given 
out  ny  otWr  channels  than  thf  lungs  is,  as  we  shall  vce,  very  slight  UO  grait. 
or  even  les*),  so  that  800  grmn.  may  be  taken  iia  the  average  jimcliiction  of 
carbonic  acid  by  an  avertige  ninn.  The  <)uuutitr,  however,  both  of  oxygen 
consumed  and  of  carbonic  actil  given  out,  is  subject  to  very  wide  variatiooa; 
thus,  in  tho  obtiervations  of  which  we  aio  sjKtiking.  the  daily  ijiianlily  of 
carbonic  acid  varied  from  686  to  1265  gmii.,  ami  llial  of  the  oxygen  from 
894  to  1072  grms.  ThtM  variBtions  nnd  their  cniitcs  will  be  discufeed  when 
wo  eome  to  den!  with  the  problems  of  utitriiicn. 

g  341.  When  the  tolnl  <iuanlity  of  tidal  uir  given  out  m  any  expiration  is 
comjiarcf)  with  that  taken  in  at  the  onrrvsponding  inHpiraiion,  it  is  found 


timt,  Ixrtb  being  dried  nnci  nienMinid  at  thv  Mine  trmjKiriiture  mxl  preaaure, 
the  ux|nftt<I  Bir  m  l«ai  in  vulumc  tliiui  thi;  ii)«pir«i)  nir.iho  dilTpmicc  nmoiint- 
in^  to  nhinit  ^tJi  or  ^th  of  tbc  volume  of  the  iiilter.  flencc,  when  un 
nnimiil  u  miid^^  to  hrcalhc  in  it  ounlirmt  s|ifl(-c.  the  iiir  n  ub«uliitety  diminiahed 
in  voluiDi'.  ThvBppruxiiDKtc  cquiviili-nci-  in  vol u me  hoiw«CD  inspired  and 
expinvl  iiir  iirUc  fmni  |]i«  fact  llwt  tlie  vohimo  of  any  given  quantity  of 
cnrlwnic  neid  i»  c<jijn]  to  the  volume  of  the  oxygen  eonsuined  to  produce  it ; 
tbo  tlight  tnlliug  short  of  the  expired  Air  \*  due  to  the  drcuiuslancc  that  all 
tbsoxygeii  inspired  does  iiot  reappear  in  the  carbonic  acid  expired,  some 
liBviiie  formed  irilhiii  the  body  other  combinations. 

4  342.  Besides  carbonic  acid,  expired  air  contains  various  mibetanccs 
which  may  be  epolien  of  as  im])uriti<s,  many  of  aii  unknown  Dature,  and  all 
in  small  amounts.  Tnca  of  ammonia  have  been  delected  iu  expired  air, 
oven  in  thai  latten  directly  from  the  trachea,  iu  which  cose  its  prvecuce  oould 
not  be  due  to  deeomposiii);  food  lin^^ering  in  the  mouth.  Wheii  the  expired 
air  is  condeosed  by  beitif;  conveyed  into  a  eooled  receiver,  the  lujueoti* 
product  is  found  to  cuniatu  urj^iic  matter,  vrbidi,  from  the  pmcnce  of 
micr&urguiisins  introduced  in  tlie  inspire*!  air,  is  very  apt  rapidlv  to  putrciy. 
The  organic  suliHance*  Ibua  shown  to  he  oreueDt  i»  ihv  expired  air  are  the 
cause  iu  part  of  the  odor  of  brc«tb.  It  is  probable  that  some  of  them  are 
of  a  poisoiioiis  iiatiire.  either  ]>oiiioaouH  in  tlieniaelves  as  comiug  direct  from 
and  produced  in  some  way  orothcriu  the  pulmoaary  apparatus,  or  poisonous  ' 
Bs  beiug  the  products  of  {Kitrefactive  decomposition;  for  various  animal 
•ubatWKM  ana  fluids  ^vo  ris«  by  dvcampoaition  to  distinct  poisonous  pro- 
ducts  known  as  ptomautfJi,  and  it  is  possible  that  some  of  the  constituenu 
of  expire!  air  arc  of  an  iillied  nature.  In  anj  case  the  mbatanoes  preeent 
have  a  dclclenouti  action,  for  an  uliiKWiilicrt-  containing  simply  1  per  oont.  of 
carbonic  acid  (<rith  a  corrc»pon<lin^'  iliniinulion  of  oxygeo)  has  very  little 
rtRvt  on  tbo  animal  M;oi)oniy,  whereas  an  atmoephere  in  which  the  carbonic 
iiciil  has  been  raised  lo  I  per  cent,  by  breathing  is  higbly  injurious.  In  fact, 
air  rendered  so  far  impure  by  brealaiiig  that  the  carbonic  acid  amounts  to 
0.08  per  cent,  is  distinctly  unwholesome,  not  bo  much  on  account  of  the  car- 
bonic acid  as  of  the  accompanying  Impuriliee.  Since  these  impuriti(«  are 
of  unknown  nature  and  cannot  be  estimated,  the  easily  detenulued  carbooio 
acid  is  usually  taken  as  an  indirect  measure  of  tbeJr  pramnoe.  We  have 
seen  that  the  average  man  loads  at  each  breath  50<)  c.c.  of  air  with  carbotiio 
acid  to  the  extent  of  4  |)er  cent.  Ue  will  accordingly  nl  each  breath  load 
If  litres  to  the  extent  of  I  per  cent. ;  and  in  one  hour,  if  he  breatlie  IT  timca 
a  minute,  will  load  rather  more  ibun  'JOOO  litres  to  the  »aiue  extent.  At  (he 
venr  teas*,  then,  a  man  ought  to  he  Hupplied  with  this  quantity  of  air  hourly, 
and  if  the  air  i»  U>  be  k«-pt  fairly  wholesuin*.-,  lliul  ia  witli  the  carbonic  acid 
n-doeed  below  O.t  ytr  cent.,  Iiv  slioutd  have  even  mure  tliau  ten  times  as 
much. 

Tub  RKeriRATOKY  Chanoeh  in  the  Bi.onD. 


$  343.  While  the  air  in  iMwung  in  and  out  of  the  \an^  iit  tlius  rubbvd  of 
a  portion  of  its  oxygen  ttml  loatk-d  with  a  certain  quantity  of  carlionic  acid, 
iho  blood  as  it  streams  along  the  pulmonary  capillnrit^i  iinilirrgiiiw  ini|K>rtaiit 
correlntive  chan(;e».  As  it  leaves  tbc  right  ventricle  it  ii>  venoiix  blucid  of  a 
dark  purple  or  maroon  color ;  when  it  falls  into  lli«  led  auricle  it  is  arterial 
blood  of  a  bright  scarlet  hue.  In  passing  through  tbc  cnpillarin  of  the  bodj 
from  the  left  to  the  right  side  of  the  heart  it  is  again  '-hanged  from  the 
arterial  to  the  venous  cunditioo.  We  havo  to  inquire.  What  are  the  esun< 
tial  diflisrences  between  arterial  and  venous  blood,  by  what  means  is  the 


452 


RESPIRATION". 


veoouB  blooJ  chaneetl  into  arterial  id  the  Iuiiks,  and  the  arterial  into  venous 
in  the^rest  of  the  nody,  and  what  relations  do  these  changes  in  the  blood 
bear  to  the  changes  in  the  air  which  we  have  already  studied? 


Vi'i,  laj. 


rilAliKAIIHATIl'  1 1.1,1*1  mm  IN    OV   T.l  UlVI'i  -    MEIHTBUr,  OA--ITJII', 

A  »nd  h  on.-  Iwu  gluw  plobes  ciimei'dil  hy  sirimg  liijia.mlilwrtiil"*:  i  unci  ).  wild  tnnfirailar 
glon  ^lotiu*<,  A'unil  It'.  A  K  Air1hi.T  coiini<<'Ieit  \ij  m^Liis  of  ihi-  i^iiiiHri'rk  r  wlrh  t^c  rect'Lver  i' 
POOtainintf  the  tfliHHl  tr>r  oilier  HiilcJ)  lo  be  nnaty;ft,<(l,  unil  b  \iy  menh^  i>f  Iho  siiijh-ivi'K  vi  and  Ibe  (utv 
mltb  Ibe  i¥<'virer  Ii  lV>r  rvrdrliiR  tbt-KHW!.  A  hiiiI  H  hivhIni  (iinrn'OIiil  uilb  tmb  i>ihvrliy  means 
of  llip  BlofHVH'lts/BdJ  i;.  ttiL-  ifliiCT  bt'liii!  «n  umiiiin.-U  lUiii  11  Bl-a)  niiiimiiiilr(ii>-s  «iib  lllj;  llii.'  imssagB 
g",  A'Hii'l  B'beiiiB  ("H  "f  mereiirj-  auj  lUt  c.iok-  I:  f,  ii,  and  rl  Wiii:  fiii'ii.  Iiiil  r  iimi  u'  tliiseil.  on 
ralAlnif  A'  by  iui^hiis  uf  tho  jriilley  ;j  tlio  iDprrury  irr  A'  itll'  At  drlrhiL:  iiliI  \he  iiiim-oiiEkiiuiJ  iiHi  Uitu 
fl,  and  ttiiont  lbroui;h  e.  Whun  Iho  morcury  hii,-'  rli^-n  iibovu  <|, /i*  flusiiT  iniil  v'  )it'iii^'Hp|ieni?d,  H'  Is 
In  (uni  rBlseil  nnlil  li  1^  i-unii'kii'ly  Hlk"!  wllb  nitrcnry.  all  lln'nir  imvinnily  in  ii  UiiiL.-  ilrivi-n  uui 
tSroiliiHe.  I'lion  i-liwtnK  ■?  ami  IubxtIhb  B'  Uio  uliiilu  of  llii;  infrrTirj-  In  It  fill  I-  in  if.  iitid  n  v«i  iiiiiii 
coiuWiuenlLj- 1'  pttablisliLiL  In  Ii.  I'n  rlii>.inKf;',  bul  iil-etiMin  r/.  f.  "Il'l  *,  "nd  lnucrin:;  .V.  ii  lai-iium 
iitfilmlliirly  o^Inbllnli^l  In  A  iind  In  tin:  Junvllnn  IrumH-n  A  and  II.  Lf  tin-  ri>cL  r  ]h-  ni-\\  iifiiHiud, 
IhCBSsen  of  llic  IiIoinI  in  C  i~caii'  '"I"  I  hi'  vwtimn  r.r  A  an<I  ll.  Ity  rai-inv-  A'  ;ifn.^r  I  In-  Lln-Lin.  uf  "■. 
and  ii]ifiiiQg  of  ll.  the  i;u-*»  "i  xl  frvc  aiv  i|rlyi>n  fmm  A  InIO  H,  anil  liy  [hi'  r,ii-ini!  <'(  If  Inim  11, 
through  f  Inii'  rhi'  ruoeiVLT  [>,  -^EHndlin;  'iv>t  nion'nry. 


The  fncla  that  venous  blood  nt  nnoe  liecomes  nrtoriid  in  aii|".'iirniii-L'  <'n 
being  exposed  tourahuken  iij)  with  nir  or  oxygen,  and  llmt  arliiinl  lil I 


THE    BS9MHAT0RT    COAN'OES    IN    THE    BLOOII.  4o3 

"mnca  vtnoiu  in  a)ifmimice  trhen  kept  fur  twine  little  time  in  a  olow<l 
^Mil.  V  ohm  •uttiniltvil  tu  u  mrreat  f>{  »uqi<>  iiiditlcrciit  gas  such  ns  iiilru- 
^or  bTdrogVD,  prvpitre  ua  for  the  Blatentent  tlial  th«  futi<lainenlal  diflrr- 
*vec  tictwtrn  venous  ami  arterial  blood  l§  in  the  relative  proportion  of  tlvc 
"VK^n  aod  Mrlxmic  aciil  ^i^eieH  cuntaiDed  in  each.  From  both  n  oeriniD 
'lUMititf  »f  gucuii  be  e.\tni(.'lt^i  bjr  means  which  do  not  othervriw  materiallir 
■jtcr  tlw  oocutiliitiou  <>r  thu  blood ;  am)  thin  khs  ulieu  obtained  from  arterial 
UdmI  ia  Ibtind  to  (MnlatD  more  oxvgen  and  K-m  farbunic  acid  than  that 
■MUtititl  fnini  veuouA  blnoi).  Tliiii  i»  th«  real  difTcreiitial  character  in  the 
**>  ViIoihIs  ;  oil  olticr  difTi-rences  arc  tilher.  iis  wi-  shall  .-we  to  be  the  caiw 
*w  tlie  ooW.  dcprmb'nt  i>ii  Hm  or  ure  iiTiirup'>riant  and  fluctiinliuf;. 
J^  tbe  quantity  <if  gn*  which  can  Iw  extnu'tcd  by  the  mercurial  air-pump 
100  fok.  or  blood  be  moaturc-d  at  0'  C.  iin<l  n  i>raeure  of  760  mm.,  it 
lad  to  ainouDi  Id  round  numbore  to  i30  vol». 

,  ^/^bv  tacuuai  produced  by  tlie  ordinary  luechanicul  air-pump  la  inaafllcient  to 
^^Uaet  all  iba  ga*  from  blooil.  Hence  it  becomes  necesrary  tn  uiw  n  mercury 
^^ttp  capable  or  prodndnj:  a  Urge  Torricellian  vacuam.  In  the  form  of  mercu- 
rial paain  which  iwan  Ludwlff'*  nnroc(Fiji.  VAi!  twu  large  globee  of  Kl>a*,oae 
~^ua  BBU  the  other  movable,  ere  i;uuDFCt«il  tiy  a  6exible  lube ;  tbe  SlM  glob*  b 
*tole  to  oxamunicate  by  oieaaa  of  air-tight  •ioiicocIch  altornatciv  with  a  roceivcr 
^notaliiing  Iha  blood,  and  'nilfa  a  rccetTer  to  collect  the  gu.  When  thr  movable 
filled  >ilh  mefcuiy  ia  roiawl  abnva  ibe  fixed  one.  the  mercury  from  tbe 
t  nuia  Into  Btid  carapletdy  fltU  the  Intter.  tliv  nir  prevoualj  preaent  being 
OBI.  After  adJuMlsf  the  cocki.  the  uiun-Kkle  globe  b  then  depreaaed 
thirty  incbea  baloir  tbe  6xM  one.  In  which  the  MtiKe<iucttt  fall  of  the  mrrcary 

raducea  an  almort  complvte  vacuum.  Uy  tiirninK  the  proper  cook  this  rocuom 
pot  laid  004)aection  with  I  he  ret' river  cpntainiiiK  the  bltHxI.  which  thereupon 
beeoiea  propcrtiuiiaiely  eiliauxied.  By  again  HdjiialliiK  the  oclt*  ant]  onoe 
Mra  eJavatiag  llie  noveableelulw,  the  giia  Ibun  extroclea  ia  driven  out  of  the 
^fti  (lobe  into  a  reeeiver.  Tiie  t-actium  it  then  unce  mure  eatabliahed  and  the 
•fanUrao  noeated  aa  loog  aa  gaa  coutinuet  to  be  given  olT  from  the  blond. 

A  laodfliea  fbrBi  of  pump  working  on  the  nainu  principli*  aa  that  of  Ludwlg, 
but  Invnlvins  the  tuc  of  oaly  one  globe  to  he  mado  vacuuuji  and  one  morable 
naervnlr  for  mercury,  hiw  teen  oouatraclcd  bv  I'lliiiref.  It  preaeota  aeveral 
adeaotagaa  over  tbe  one  {uhi  deeoribed,  the  chiei  being  thai  (I)  non-deflbri anted 
Uaod  auy  be  aacl  for  the  eitracUoa  of  gaaee,  (S)  tlu)  vacuum  into  which  the 
paea  an  evolved  i«  large,  (3)  ihia  racnam  ia  hem  drv  by  being  connected  lalci- 
allj  irith  a  vacuooa  dianbftr  ooniainiaK  mlpbunc  acid.  Tfaedeiaila  of  ila  eon- 
Mractlon  are.  bowever.  oompllcHtcd.  and  the  greateet  care  ia  required  in  ita  uae 
ti>  avoid  breakage.  Of  Inter  yrars  a  almplllled  form  of  pump  Iim  been  tntro- 
diM*d  for  laboratory  work.  It  na*  flrat  aaMl  by  (tri^haot  and  i'aul  Bert,  and  la 
now  frMHfotly  callfol  an  Alverpiiat'a  pump,  froni  the  name  uf  ita  preaent  maker. 
Ptff.  ISa  give  adiaKraramatic  repreaentatiun  of  Itn  con»tructioii. 

A  M  a  gloM  bulb  auioe  five  Incbm  in  diameter,  blown  oa  toaglaia  luben  below 
and  on  lo  a  vertical  tube  b  above.  The  lower  end  of  i  it  oonaected  by  ■  thlck- 
wallcd  India-TubbcT  lube  witli  a  icucrroir  fir  meacnry  B,  whiuh  can  be  raiaad 
and  lowi-rrd  hy  mean*  of  a  ■irinj;  ihuwok  over  a  DUlley  r.  The  vertical  tubo'^ 
Ib  Ihickenrd  ■!  one  place,  and  into  tbia  thickened  iiortion  a  Ihrco-way  tap  'I  b 
lirouod.  The  upper  end  of  A  b  prolonged  lahuve  ihe  ihice-way  lap)  inlu  a  line 
paint.  Th-*  (KMot  pawH  by  a  tight  joint  throaith  the  botloin  of  a  vcMel  r,  which 
ran  b*  |>aTl!r  HUrd  with  inrnuty,  and  over  vhuh  a  receiver/.  Illled  with  ini-r* 
nirj  for  the  L-ullcclioii  uf  tlie  i:aw>.  can  be  inverted.  A  tube  y  fuaed  on  laterally 
to  due  tiMolng  of  the  tbre«-way  tap  'J  plaeei  the  lailer  in  connection  with  a 
iblck-aralled  Woulff'a  bottle  t'cuiiiaintng  a  layer  nf  mrong  *ulphuric  add.  Tbo 
«H;oniI  lulMilure  of  tlib  bottb  t*  •imlturly  connected  bv  an  claatic  lube  with  the 
ir«el  i>.  iiilo  which  blood  or  othrr  llui<l  tuny  be  iutiuluced  by  inean^  of  tbe  lap 
A.  All  the  movabtu  joints  nf  ibi:  a|i)ianiius  arc  jiiotected  by  India-mbber  tubM 
loin  wb'ch  water  can  b«  poure<l.  and  a  nieial  caalng  round  the  lap  if,  which 
nmj  alio  be  illled  with  water,  limilarly  prevoota  the  powiibility  of  any  leakago 
bM*. 


464 


BB8PIRATI0N. 


The  pnmp  is  lued  u  foUom.  By  placinK  the  Up  d  in  the  portion  ahowD  ia 
the  figure  and  rutiog  B,  the  balb  A  may  be  filled  with  mercurj  up  to  the  top, 
the  coQtaiaed  air  bein^  expelled  through  the  upper  end  of  b.  Bf  a  elight  tnni 
of  the  t^  all  connect'on  between  A  and  either  the  tube  g  or  the  npper  MTt  of  b 
may  be  cat  off*,  and  on  lowering  B  a  Tacnum  U  eatabliahed  in  the  bnlb  A  and 

Eart  of  the  tube  a.  A  may  now  be  connected  by  the  tap  d  with  the  tube  o,  and 
ence  with  (7  and  D,  and,  h  being;  closed,  a  partial  Tacnum  ii  eatabliahed  in  C 
and  B.  By  meani  of  the  tap  d  the  air  In  A  may  be  cnt  off  from  g,  and  on  raia- 
lug  B  and  placing  the  plnr  of  if  aa  shown  in  the  figure  this  air  may  be  expelled 
throngh  the  npper  end  of^.  By  elightly  turaing  d  and  lowering  B  a  Tacuam  is 
Main  eatabliahed  in  A,  and  aa  before  a  further  portion  n{  aXi  in  (7 and  D  nuty  be 
wlowed  to  pas4  over  into  A  and  the  racaum  in  D  and  C  increased.    In  this  way 


Fio.  lis. 


Q\ 


^^::^ 


DUOKAII  or  ALVERaM.tT'B  I'i'sir, 


all  the  air  in  D  can  be  extracted,  the  final  stngea  being  facilitated  by  the  admis- 
doQ  of  a  little  water  into  D,  the  last  truces  of  air  being  ilriven  over  into  A  by 
the  rush  of  vapor  from  the  water.  A  known  volume  of  blond  having  been  col- 
leoted  over  mercury  in  a  small  tube  is  now  allowed  to  enter  D  through  the  tap  A 
ud  yields  up  its  gases  to  the  vacuum.  A  repetition  of  the  processes  by  which 
thA  wr  in  J)  was  originally  extracted  will  now  remove  the  goi^es  which  have  been 

Sven  off  from  the  Known  volume  of  blood,  the  only  difl'erence  being  that  now 
e  tube/filled  with  mercury  is  inverted  in  the  trough  e  over  the  iip]>er  end  of 
the  tube  b.  In  this  way  the  gasee  originally  in  D  nrc  not  allowed  to  escape  into 
the  air,  as  was  the  case  when  the  apparatus  was  being  originally  made  vacuoDH. 
but  are  collected  in  /  for  anhseqaent  analysis.  During  the  extraction  of  the 
gaaea  from  the  blood  the  bulb  l>  is  immersed  in  avesaelorirarm  ivater.  to  facilitate 


TOK    HESPIRATORy   CHAXOES   IN  THE   BLOOD. 


4S5 


iIm)  pxit  of  th«  giwc*  >ti<I.  t>v  raufin^  tlio  r»nn»tion  of  Urj^  quAnlitin  of  aqueous 
vnt<or,  U>MrMpiltc|C>uc*r*pi(lljr  urcr  ioto  A.  Tb««ulpliuriciK:i<l  cbsmbcr  CdrJM 
tli«  vnouum  befote  ibe  admlMion  of  the  blixij  into  O.  aad  hence  makea  it  more 
|i«tf<>ct  and  tnuBM  Uie  mott  oo(Di)l«t«  and  rapid  evolution  of  gun  ttnta  the  blood . 

The  nverage  rompoAition  of  tlie  g&§  thus  obuiitied  from  «nch  of  the  two 
kinds  of  blood  (the  arloHsl  blood  being  taken  from  a  Iiir;>e  arlery,  and  tbe 
venous  blood  from  the  right  side  of  the  hearti  U,  slated  lu  round  numhera, 
aa  foUowB : 
From  too  vola.  may  b«  obtained— 

or  oxyvtn.  U(  (vrbMilo  aald.  Ot  nlln««a. 

Of  arterial  blood,  SOrols.  «>  toIs.  I  (o  S  vols, 

or  Tcuinu  blood.  $ti>12vok  -k!  vols.  1  to  S  vols. 

•II  ateuured  at  '<X)  mm.  aud  l>'  <:. 

That  is  to  Bay,  venous  blood,  as  compared  with  arterial  hlood,  eootaios  8 
to  12  per  cent,  lew  oxygen  and  l>  ]>er  «eiil.  more  oarbonic  avid.  It  mnat  be 
i-eiiiem)>ere4),  however,  tliat  while  arterial  hlood  from  whatever  arlery  takeii 
h>N  alwayti  nearly  the  itame  proportion  of  gasMw,  or  at  all  cvunl«  the  xame 
•mount  of  oxygen,  the  amouut  of  uxvEen  in  venouN  bboci,  cvui  when  iiikea 
from  tbc  »me  vein,  may  Thty  a  good  deal,  utill  mort<  w>  when  it  is  taken 
from  diHercnt  veins.    The  rea«on  of  ihi*  we  Mhall  fix  hereafter. 

It  will  be  I'onvnulenl  to  cj]D«l(lcr  the  relntiona  of  endi  of  these  gases  sepa- 
rately, 

TAe  Rdaliont  of  Oiffytn  in  Uw  Blaoit. 

$  344   When  a  liquid  such  as  water  is  exposed  to  an  atmosphere  contain- 
ing a  gaa  such  as  oxygen,  some  of  the  oxygen  will  ba  disaolred  iti  tlie  water, 
thai  b  to  aay,  will  be  absorbed  from  the  atmosphere.    The  ouantity  wliich 
IB  to  abeorbed  will  depend  on  the  premure  of  the  oxjgen  in  tlie  atmmtphero 
'  above ;  tbe  greater  the  pressure  of  the  oxygen,  tbe  larser  the  amount  which 
will  be  abeorbed.     If  the  pressure  of  the  whole  atmosphen'  remnin  thi-  sante, 
at  700  mm.  of  mercury  for  instance  (tbe  ordinarv  atm<isph«rii:  t>n:N>ure),  the 
priTtiurt!  iif  tbe  oxygen  may  bi-  incn-ased  or  iliminished  by  increasing  or 
diminishing  the  proportinu  of  uxygni  in  thu  iitmimphvre.     tio  that  with  an 
Bimonphere    renutinmg    at    any   givi-n    pmwurQ  the   4uanlity    of   oxygen 
•bwirbed  will  depend  on  the  quantity  jirexwt  in  that  umosphore.     If,  ou  the 
J^thcr  hand,  wat4:r,  already  conliiiiiing  a  good  di-nl  of  oxygen  dimolved  In 
it,  be  exposed  Ui  an  Rtmosphen-  coDtainine  little  or  no  oxyge^,  the  oxygen 
will  escape  fK>m  the  tralrr  into  th<-  ntmiHplicre.     The  oxygen,  in  fact,  wbioh 
is  dinolved  in  the  water,  like  the  oxygon  in  the  Htmospnere  above,  stands 
iti  a  crrlaiD  prmsure.  the  amount  of  pressure  depending  on  the  quantity 
dissolved ;  and  when  water  containing  oxygen  dissolved  in  it  is  etpoeed  to 
any  ntniMphere.  the  result,  thai  i^,  nbolfier  the  oxygen  escapee  from  the 
water  into  the  atmosphere,  or  pusses  from  the  iitniosphere  into  the  water, 
depends  on  whether  tbe  pressure  of  the  oxygen  in  the  water  is  greater  or 
Jeasthan  ibe  pressure  of  the  oxygea  in  the  atnoephere.     Ilenee.  when  water 
v%  oxposed  to  oxygen,  the  oxyc«4i  uthor  escapes  or  is  absorbed  uutii  equili- 
I  briiim  ia  esubliMied  between  tne  pressure  of  the  oxygeu  in  tbe  almcsphera 
f-above  and  tbe  preastire  of  the  oxygen  in  the  water  below.    This  result  i^  as 
(hr  as  mere  absorption  and  escape  are  concerned,  quite  in<lependaut  of  wliai 
oilier  gases  are  present  in  the  water  or  in  the  atmiisj)bere.    Suppose  a  half- 
litre  of  water  was  lyinj;  at  the  hoUom  of  a  two-litre  tlask,  and  that  tbe 
atjncapbere  in  the  flask  above  the  water  was  otte-Lbird  oxygen ;  it  would 
make  no  diS'ereiice,  as  far  as  the  aluorptitm  of  oxygen  by  the  wat«r  was 
cnQeemed,  whether  tlte  remaining  two-thirds  of  the  almoupbere  vai  car- 


boni*'  bpkI,  or  nilroMB,  or  hvdrogtrn,  nr  wluttlivr  tb^MM  nftoTC 
mi  It  vncuiim  tilled  lo  ODe-lliml  Kith  pure  oxyeon.  Hcdco.  ii  ii>  said  tliat 
the  nbicrplioii  of  any  gns  (Io])«iidi'  on  Ihi-  jifiriiaf  pfiuurt  of  thnt  gn*  iii  tb« 
atiiKM'phGrc  to  which  Inc  lifjuid  i»  exp«scil.  This  ie  Inir  iioC  unly  of  oxjr^n 
Biid  WDtcr.  but  of  111!  gusce  and  h<]iii()ii  which  do  not  rtitvr  iiiUi  rhctoic*! 
c-onihiiinciotfuith  ench  other.  Diticrent  litjuide  will,  of  rotirto,  stwirb  dif- 
ferpDl  gflecs  wilh  diftcring  rendiiicMi  bin,  nilh  th«  anie  g**  itiid  (bvMiW 
li(|(iid.  ihc  aniouiu  aheurbed  uill  depend  directly  i>n  the  pnrlini  prrsflirv  of 
the  gfls  iu  the  oTerlyiOj;  space.  It  should  be  added  that  lite  proc<«#  i»  Riucb 
jnBuenced  by  temperature.  Hence,  to  stale  the  nialter  Renerally.  tlw  ab- 
soqrtioii  of  aDv  gas  by  any  linuid  will  depend  ou  the  nature  of  the  g».  itie 
nature  of  the  liquid,  tfae  pieuure  i>f  l\ie  gua,  and  the  t«inpenUure  at  wbkb 
biith  stand. 

Notr  it  uii^bt  be  Buppote<I,  and  Indeed  was  once  supposed,  that  the  oxygMi 
iu  Ibe  blood  wtu  Dimply  diwolved  l>r  ibe  blood,  if  this  were  so,  then  the 
amount  of  oxygen  preteut  in  iiiiy  given  quantity  of  bloud  exposed  to  any 
^ven  attnoaphore,  ought  to  Hue  and  fall  Ntendily  und  regularly  as  lite  par- 
linl  preitiiure  of  oxygvii  Ju  that  ntmo«pherv  in  iiicrruwd  or  diniiuiabed  ;  the 
nliMirption  (or  tscaptO  of  oxygen  ought  lo  fijllow  wlml  i»  kuoivn  a*  the 
Heurt-Dalton  law  iif  pn-miin-s.  But  tJiis  is  found  not  to  be  the  ca*?.  If 
wi;  expose  bloud  conUiiiiiiig  little  or  no  oxygen  to  a  siiccreiiion  of  »tmo«pheie« 
contninin^  inurcusiiig  <jii»iititips  of  oxygen,  we  find  that  nt  tina  ihi-rciia 
very  rupid  abeorntiun  of  llic  nvniluble  oxyjjcn,  and  tht-n  this  Mtmewhul  »ud- 
donly  censes  or  Dccomes  very  aninll ;  nnd,  if  on  the  Other  h»n<l  vt:  xubnil 
nrlerial  blood  toeiicoesaively  dimioishing  preieures,  we  fin<l  that  for  a  long 
time  rerv  little  oxygen  is  given  off.  and  then  suddenly  the  etcape  beoomM 
Tery  rapid,  The  abeorplion  of  oxygen  by  blood  does  not  lolloiv  the  general 
law  of  ohearpliori  according  to  pressure.  The  pheDomena  on  the  other  hanii 
BUggeBt«  the  i<leu  that  tbe  oxygen  in  the  blood  is  in  some  particuhir  combi- 
nniion  with  a  substance  or  some  aubstances  present  in  the  olood,  llie  combi- 
nation being  of  such  a  kind  that  it  b<il(U  good  during  a  lowering  of  pt^oaim 
down  to  a  eertuin  limit,  and  that  then  diNfociation  riaidily  occur*;  we  nay 
add  that  ihiit  limit  in  vory  cloudy  dcp-tident  on  temperature.  It  u,  bow- 
evi*r,  not  to  l>c  NuppniH.'d  thnt  ii*  the  pri.fwure  is  luwMvd,  no  oxygen  what- 
ever it  given  off  from  the  ■ubntitiicc  until  a  certain  point  U  reached,  and 
that  at  that  point  the  whole  store  is  iu  an  iustant  disKciatcd.  no  more  r«- 
tnuintne  to  bi^  given  ntf.  The  citao  is  rather  that  while  pressure  U  beinz 
lowereiTdown  to  a  ccrtnin  point,  no  appreciable  dissociation  takes  place,  and 
tlutt  then  h.-iviiig  begun  it  increases  rapidly  ivith  euch  further  lowering  of 
pT7«suie  until  the  whole  of  the  oxygen  is  given  otf.  During  this  narrow 
range,  between  the  lirsl  beginning  to  give  oH'  oxygen  and  the  coiuplMion  of 
ihi-  giving  oH',  the  compound  of  the  oxygen  with  the  sulwlance  or  subetancca 
may  be  *])oken  of  as  partly,  that  Is  more  or  leaa,  dioaociaied.  What  is  lb* 
eulvtance  ur  what  are  the  substances  nitli  vrbieb  the  oxygen  is  tiius  pecu- 
liarly conibioed* 

If  serum  free  from  red  corpUBcle*  be  u»cd  in  Nucb  ahitorption  experimeou, 
it  is  found  (hat.  as  roi:i|iared  with  the  entire  bkHid,  very  little  oxygen  is 
absorbed,  about  as  mud)  ax  would  )>e  nlworbcil  by  the  MUne  iiuantity  of 
water;  and  such  an  in  abnorhcl  ilix-s  follon'  the  liiw  of  prratum.  Iu  natural 
arterial  blood  the  ipuinlity  of  oxygrn  which  cnn  l>e  obtained  from  serum  is 
excetslinglr  amall:  it  <lot«  not  amount  to  half  a  volume  in  one  hundred 
volumM  (if  the  entire  blood  to  which  the  serum  bclongetl.  It  ii>  evideat 
ihnt  the  oxygen  which  is  priscnt  in  hlooil  is  in  some  way  or  other  jK-culiarly 
c»nnccl(.-d  with  the  red  corpuscle*.  Now,  the  distinguished  feature  of  tlie 
nd  ciirpusclefi  ix  the  presence  of  hwmoglobiu,     We  have  already  seen  'J  24) 


^ 


THK    ItesPlRATORT  CRAIfOBS  \S  TKB  BLOOD. 


457 


I 


I 


tliftl  thi«  cotiMiluics  !Kl  per  cent,  of  the  drie*!  ml  i"or|HUi<;le«.  TJi«re  cnu  be 
A  priori  little  ^l<r^lh^  tl)ii(  this  niUHt  bo  tb«  subatntit'O  wilh  vrhiuh  the  oxygen 
w  (Dwiriatcd,  itnd  lo  lli«  propcrliM  of  this  bmljr  w«  muA  tlicrefuK  <lirecl 
our  ntleiitiou. 

S  345.  Ifirmoqtobiii.  When  »«|>3rii(eil  from  the  other  conGlitiivnlii  of  the 
sertini,  hwii)oi>Iol>iD  apjiears  hs  a  fnibeiauce,  eitlier  nmorphous  or  erj'ntJilUac, 
radily  solume  io  wiitcr  (eapcciully  in  Marrn  wHi«r)  and  in  wrum. 

Kincr  bntnoglobtB  i*  noluMc  in  serum,  luiil  Miioo  tliv  idrnlity  of  the  cryMaU 
»l>srr*r4l  occuKiaally  irjlbio  the  corpiHolcit  irilb  Ibnae  obtained  in  olber  ways 
ahuna  tliNt  th«  ha>inuelubiii  a*  it  cxinu  in  (he  corpittvie  it  tbe  aaine  thing  n«  that 
wliicb  is  arliflrially  (irepared  from  blouil.  it  la  evident  that  Bom«  peeuliar  rrlutioii* 
ahip  b«lwern  the  Vtrcnia  aod  the  bwnioglobin  muM.  in  natural  blooil,  keep  the 
latirr  froai  l>einK  iliuglviKl  hr  ihr  lemtn.  Hesc^,  in  prrpurinf;  lucmnglobiii  it  ia 
atemmty  Am  at  all  tn  brrnk'up  Ib'u  cnnnTclino  and  I'l  wi  tbo  biemnglubtn  free 
from  Uie  corpuaclvH.  Thin  mny  be  done  bv  the  aililitloa  of  WHier,  of  ethrr.  t>f 
chloroform,  or  of  bilp  *«li«,  or  by  r«'|>eAtealy  fret/.iiig  and  ibawiriB;  blood  »» 
treated  becoraoi  "  laky  "  ((/.  {  24].'  U  Id  a)»n'of  advniitaee  prcvicnmly  lo  remove 
the  alkaline  ■erum  lu  tiiu<;h  a*  piHwiblc.  hi  iw  to  oj^rnlc  only  on  the  red  coriinitcJe*. 
Tbeatronta  and  ba^mugiubin  btiiif;  tfaiM  tvpHraied.  a  Butiitlun  of  bu'niotflobin  in 
lb«  rMult.  The  allcalinily  oT  the  BDluti'-'ii,  when  pmeni,  being  rcdiiceii  by  the 
catitinut  a'ldiiiim  of  dilute  aeetic  aoi<i.  and  the  Mlv«n(  power  "f  the  wiiieoii* 
m<diuin  beini;  diminialml  by  th<^  iiddilion  of  onft-l'ourth  tl*  bulk  of  ulc<illul,  llie 
mixture,  lei  ajtide  in  a  lemperalua-  of  U*  C.  in  order  atill  further  to  reduce  the 
aolubililjr  of  tbe  hieiuoclobln,  readily  cryatalliiea,  when  tbe  bloo>l  ii^e-i  i'  that  of 
the  dog.  eat,  hor»e,  rat.  eiiinea-jii^,  etc.  In  (be  eaae  of  the  dnf,  indon),  it  la 
aimptr  atilBcietit  to  add  dbrr  mrefully  to  the  blood  iinlil  it  jual  becomr«  "  laky." 
and  then  lo  let  it  viand  In  a  coal  place;  tbe  mixture  toon  beoomeaa  miMof 
crratala.  The  cryitaU  may  be  (eparated  by  lillralion,  rediaaolred  In  water,  aod 
re-cT)Ualliie)l. 

Hemoglobin  from  the  blooil  of  ibe  rat,  guinea-pit;,  X]>iirr«I.  bMlt^bng, 
bDrre,  cat,  dog,  gixve,  and  some  other  animah,  crvHlalliites  readily,  thii  crvn- 
tab  being  generally  blender,  lonr-eided  iiri^mu  ttcloukriuj;  (o  llie  rhonioic 
qratem  imd  oAeo  npfesrini;  (|uile 
adcular.  yFigs.  \M.  1^5,  IM.]  the 
fiiTTBtds  from  the  blood  of  the  giiineia- 
pig  ar«  octahedral,  but  also  Moog  to 
the  rhombic  aystein :  those  of  the 
SQuirrcl  are  six-eided  t'l^'*^  I'he 
blood  (if  the  ox,  ^heep,  ruhljii,  utj!;, 
and  miiu  cryMflllizi(«  with  difliriilty. 
Why  the*«  ililTereuns  exist  ii  not 
known;  but  the  c«in{iii#ilii'u  niid  the 
unountof  waier«fcry»lKlIi/alii>ii  vary 
soineuhnl  ID  ihtt  cryntHlii  ol)iaiur<l  fr-itu 
difttrreiil  anii»ul.<.  In  the  do){  the 
[>crceiit»;ff  (•omimaition  of  the  cry*- 
IhU  ban  Ixt'ii  detcnninrd  im  C.  ri!l.'<>5, 
H.  7.32,  N.  10.17.  (>.  m.M.  S.  O.XU, 
Fe. 0.43. with  -i  to4  percent. of  naler 
of  cryttnlli/HlioD.  It  will  thus  tte 
wen  that  hnmoglnbin  cunlninK,  iti 
nddition  to  the  other  cleiuenlR 


tn-..  iM, 


■  *-^. 


Tn««iiMiN4L  raDH  Iiiuoe>  o»  tiu  rio.i 

to  the  other  cleiuenlR  usually  present  in  proteid  Biibelancc».  a 
certain  nmotint  of  iron ;  that  is  to  My.  the  element  iron  is  a  distinct  part  o{ 
the  hwmoglobin  molectde.n  fact  nhich  of  itself  renders  biemo|jIobiii  remark- 
able amoiii;  the  chemical  subttances  prcwnl  in  the  animal  body. 

i  346.  The  crystals  when  fcen  in  a  sufficiently  thick  layer  uuder  the  micro- 
act^  have  the  tome  bright  scarlet  color  as  arterial  blood  has  to  the  naked 


4r>s 


IPIKATION. 


«)% :  when  aeen  in  a  maas  tbev  natuniUy  n|>peAr  <lnrk@r.  An  aqueous  Bolution 
of  tmnuiglobiii,  obtained  b7<)iaatlviu|(  [luHlied  or^tnls  iu  ilLslilleil  water,  lia« 
atoo  the  HUne  bn){bi  arteriitl  mior.  A.  tolerablf  dilaU  Mlution  phoed  before 
ibe  apectriMcope  U  fouud  t<i  alHorb  eertaia  rays  of  lis;bl  in  a  peculiar  and 
characteruuic  manner.   A  jiuiiinit  of  Ibe  red  eaa  of  the  apectruia  is  absorbed, 


(no.  Hi. 


[ni>.iM. 


ti- 


l^*" 


< 


llRIAiMMill.CBVvrtMl'IIOli  tlUKiDnr  KgltlDRll. 

KT<i»i<*il  InstWIlBM  ig*na«r.  noi  iinfn^iitnllr 


llmttTiL'  r«uM  llinttx  RijMB.] 


M  i»  also  n  luucb  larger  portion  of  the  bluo  end  ;  but  what  is  aiml  "trikin^ 
ti  the  nreaeccc  of  two  stron];;ly  marked  abfl'>rptioii  bands,  lyin)^  between  tbe 
Rolar  linex  />  and  A'.  (Se«  Vig.  137.)  Of  these  the  one  toward  the  red 
side,  fiooielimea  spoken  of  as  tbe  band  (a),  in  tbe  thiDDeM,  but  the  inoat 
intense,  and  in  extremelir  dilute  soliitioni  (Fig.  1^7.  I)  is  tbe  only  one 
vittble;  its  middle  lies  at  some  liule  distance  lo  the  blue  side  of  I).  Iu 
position  may  be  more  exa«t]y  deRned  by  eipressios  it  in  w  ave-lenutbs.  Aa 
la  well-known,  tbe  ravit  of  tight  which  make  u|>  tlie  Hpeclrura  dilTer  in  tJte 
length  of  their  wav«M,  dimioiHhing  from  tbe  red  end.  where  the  wuvei*  are 
longMl,  lu  the  blue  end,  where  they  are  ahorte&t.  Thus.  Frauenhotbr'a  line 
D  correspODdii  to  rayit  bnvlujc  u  wave-leiwth  of  589.4  millinntbH  of  u  railli* 
metric  U»in^  tbu  name  unit,  the  centre  or  thix  abttorplioii,  bund  »,  of  hiemo- 
glohin  corrvMpondii  to  tbe  wavc-leuj^lh  578;  us  may  bo  seen  in  Fiu;.  1^7, 
where,  ho«ev<ir.  the  nitmbcn  of  thi;  div-tuon*  of  the  dcalc  indicate  nnly 
100.000  of  a  millimetre  Thi?  other,  iii>riietime«  called  ff,  much  broader,  lie* 
II  little  to  the  red  tide  of  E,  ila  bluewanl  odgc,  even  in  modcmtely  dilute 
■oUilion^  (Fig.  1S7,  'i),  coming  close  up  to  that  lino;  it»  centre  corresponds 
to  about  wavelenglh  o')0.  Each  band  is  thickest  in  tbe  middle  and  gradu- 
ally thins  away  al  the  edges,  These  two  absorption  bands  are  extnmely 
characteri)itic  of  a  siilution  of  haMnogtobin.  Kven  in  verr  dilute  solulioDs 
both  bands  arc  visible  (they  may  be  seen  in  a  thickness  of  1  em.  in  a  solu- 
tion containinj;  t  Kroi-  of  liiemoKlobin  in  10  litre*  of  water),  and  that  when 
scarcely  any  of  the  extreme  red  end  and  very  little  of  the  blue  end  is  cut 
off.  They  then  appear  not  only  faint  but  narrow.  As  the  strength  of  the 
solution  i*  increaieJ  the  band*  hmiden  and  bsome  mire  inlen*e:  at  the 
same  time  bith  llie  red  end,  and  still  mire  the  blue  end,  of  the  wlfito  spec* 
Inim  are  encroached  upon  (Fig.  137.  3).  This  may  go  on  until  the  two 
alMorptioD  banda  beoame  fused  to-^ther  into  one  bnia  1  bml  (Fig.  137,  4). 


1 


BRSIMRATI 


The  only  ntTfi  <>r  liglii.  nhicli  ihen  pom  tlirnD^h  thi-  bwi 
are  those  in  Ihe  |>rccii  between  the  bluennnl  eitge  iif  ibo  united  Iuidi1>  buiI 
the  geil«ral  abeorplinn,  which  is  now  rstiidly  sdviinciii);  Cmm  thf  blue  toA, 
aod  Umm  ill  the  red  betuceii  the  united  mind^  mid  the  geiierni  alK»r)itioa  ml 
ihe  red  end.  Jf  the  aoliiiioii  be  elill  fiirther  iucreoaed  in  &lrciigih,  Inv  inter- 
Val  uu  the  hhie  xide  of  thi^  united  bands  beconiefl  absorbed  atai,  bo  tb»i  ilia 
only  rmya  which  i>asii  ihrtiugh  are  the  red  rays  \yios  lo  the  red  sido  nf  0; 
th«M  arc  the  but  in  disa|){ieHr.  and  lieiice  tlit.-  iialunu  red  color  of  iIk-  wlu- 
lion  ii»  unea  bj  trnuiiniittLiI  litcht.  Hxacilv  tW  sanae  appearances  mn  ttta 
wbdi  crvMHlit  af  hiemiif^hihin  are  ixumiueil  with  a  inicnvspeolroscope.  Tker 
nre  itN"  m-cii  n'h<-ji  arterial  bluod  il^i'lf  (dilutvil  with  ^ine  Mitiitiotts,  to  that 
tlw  corpuscles  remain  in  n.-i  natural  »  condition  lu  puwiihie)  u  exaniiued  with 
(he  sprctroscopc  at  well  a*  when  u  ilrop  of  btiind,  which  froin  the  necemirv 
exposure  to  nir  is  nlways  nrterinl.  ii"  cxaniimid  nilh  lh«  micro-sitectrowofL 
In  fact,  the  Hpectruiu  of  tiiciuoglribiii  is  ihc  «|nviriini  "f  nurinal  arterial 
blood. 

5  347.  When  crystals  of  hacmiiglohin,  prcpttrcd  in  the  nay  dcuciibcd  above, 
are  Biihiectcd  to  tlie  vacuum  of  the  mernirinl  Hir-|nimji,  they  give  uff  a  certain 
quantity  uf  oxygen,  and  at  the  same  iJnie  they  chniige  in  color.  Tltc  rjuautitr 
of  oxygen  given  olf  is  deSuile,  t  giiu-  of  the  cryttalf  giving  off  1.5i*  ce. 
of  oxygen  nieaeured  at  7l3U  mm.  U^'.  ami  U'^  C.  In  other  word».  the  cri-»taU 
of  bKnioglobin,  over  and  above  the  oxygen  which  enters  iiilimatciv  iut<>  iha 
oompoeitJQU  of  the  molecule  (and  wliich  alune  u  f;ivca  in  the  eleiucu 
coiDpontion  nri'viuuHly  stiitw)).  cnniaiti  another  ijutuitity  of  oxygen,  whit 
in  looee  conifiinnlion  only,  and  which  may  be  dissociated  from  them  by  • 
jectinj;  them  to  a  sultimnily  low  pnjwure.  The  chau^  of  color  which 
ensued  when  thi>  Imwcly  cuinhined  uxygen  ia  r>:miive<l,  iti  churacieristic ;  tbt 
crystals  bci-umv  darker  and  more  uf  a  purple  hue,  and  at  the  aaiDfr  tim* 
dicJiruic,  so  that  while  the  thicker  ridg««  aru  purple,  lli«  thin  edges  apfwar 
gT«eni»1i. 

An  ordinary  solution  of  bicmoglobin,  like  the  cryrtttis  from  which  it  is 
fornted,  contains  a  definite  <|Uantity  of  oxygen  in  a  similarly  pcctiliar  loots 
combinntion  :  ihia  oxygen  it  also  gives  up  when  tubjocled  in  the  air-ptimp  U> 
Butliciently  low  prcMurc,  becoming  at  the  same  time  ot'a  piir^ilish  hue  Tbii 
loosely  combined  oxygen  may  also  be  reniovet)  bv  passing  a  strenm  of 
hydrogen  or  other  iudiHereul  gas  through  the  solution ;  the  stream  of 
hydrogen  acta  tike  an  oxygen- vacuum  to  ihe  hienioglobiu  and  thus  di»a»o- 
cialion  iseSecIed.  Carbonic  acid  >;as  is  uusuitablel'or  this  purpose, since,  at 
ue  shall  see,  huiiis;  an  acid  it  acta  in  another  way  on  the  hemoglobin.  The 
oxygen  may  alto  be  rt^movcil  tVum  ihi-  hitmoglohin  not  only  by  phyucal  bul 
also  bj  chcinienl  means,  as  by  the  iiaie  <•(  reducing  ageNts.  Thus  if  a  few 
drops  of  ammonium  sulphide  ur  of  uii  alkaline  .■Hilntiim  uf  ferrous  sulphate, 
kept  from  ]ireciiiiiHtiun  by  tho  pn'M-nce  of  tartaric  acid,  he  added  lo  a  solu- 
tion (if  hiemugIol)ln.  or  even  to  an  un|>uTilicd  Solution  of  blood  eor|>uscIea 
•ueb  II*  i>  airunhd  by  the  woshiiigv  from  a  hluod  clot,  the  oxygen  in  looee 
combination  wilh  thy  hiem«);Iobin  is  immcdinlclym.'ij!ed  ujwn  hy  the  reducing 
agent.  This  may  he  rrcitgnized  at  once  hy  the  chBraclcriMic  change  of  color; 
from  a  bright  scarlet  the  solution  becomes  of  a  purplish  claret  c<dor,  when 
teen  in  any  thickness,  but  greenisli  when  sufficiently  thiu ;  the  Color  of  tbo 
reiluccd  solution  is  exactly  like  that  of  the  crystals  from  which  Ibe  looM 
oxvgcn  has  bri?n  removed  by  the  air-pump. 

Kxamined  by  the  B^iectroscope,  this  reilueed  solution,  or  solution  of  nWucvd 
hanaoyliAiti,  as  we  may  now  call  it,  otters  a  spectrum  (Fig.  1 37,  fi)  very  dif- 
fereot  from  thai  of  the  unreduced  soluliou.  The  two  ab'oriiliun  Wild*  Imve 
diBaiip«re<l,  and  in  their  place  tboie  b  seen  a  single,  muca  broader,  but  at 


THK    nK9FIRAT< 


461 


I 


I 


I     tU  mtat  tvat  niucb   fainter  Imixl.  wliimc   miiMlo  <>i-('ti{m«  ii  iiiuiilian  ntmut 

mUnr  betvecn  Uk  (wu  nbiiirpliuti  ImikI*  nf  iIil'  iiiiix'ilucnl  solutinu,  tlxnigh 

tUftivKld  edge  of  tbe  bnnd  ^IiikIi-h  nntn    n»tlii-r   I'lirtlK^r  townni   (lie  ntl 

tin  don  the  other  edge  townni   ihc  liltir ;  iu  ci^nln!  cormnioiiil*  lo  iiliuut 

tmlMglli  &S5.     At  thv  Mime  liniir  tbr  ^mi'ra]  iilwnrption  i)f  the  »pceiriiiti 

I     lidiArnl  fttMD  that  of  tli«  unrcilucvil  mliitioD ;  IriM  of  \lw  blur  vutl  i» 

tituhld.     Eren  wlien  the  wlulinno  bccnine  tolcrubly  cowrentrnlcfl.  maiiir  of 

lit  UaUi-grteo  rajv  to  tbe  blu«  rkIc  of  (ho  siDgl<i  bitiid  still  y>n»  through. 

Bnmha  dHhnae»  in  color  Wwoen  Iwnioelubin  which  relniriB  ihi^  InoMly 

owiUnMl  oxrgrti,'  nnd  hinDoglobin  whicli  hiu  Icwi  ii«  oxrci^n  ntid  liccome 

'•diKtil.     ]n  tolerabljr  ooncenlnitec)  solution*,  or  tolerably  thick  Invcre,  th« 

^natr  Ivl^  Ihrnugli   lti>-  ml  and  the  omti^-Tcllow  rays,  the  )»lter  tbe  red 

'Ofl  ill*  hluich-^'nvii   rave.     Accordingly,  the  ono  iipi)cnr8  ecnrlct,  the  other 

Ijurplc     la  dilute  •ulutioDe,  or  in  n  thin  liiycr,  the  reduced  biemo)>!obin  leta 

'^>^gh  H>  nmch  of  Ihe  green  ravn  that  they  jirepoudernCe  over  the  red.  atut 

'**«  t^ltins  imprewoD  ia  one  of  t;reei).     In  lite  unreduced  huemiit-ldbiii  or 

^Ky-hviDo^lubin.  tbe  jiotem   yellow  vhich   is   blocked   out  in   ilic   reduced 

'^^■ofllabiD   make*  Hmf  fell,  so  that  a  very  tbiii  Inyer  uf  oxy-hieinoglobia, 

**  b  a  ainjcle  eorpaade  seen  under  the  mteroscope,  uppeara  ycUovr  rather 

*ha«  red. 

It  tniiat  be  reroerubeml  that  wlwu  we  fl)ieak  of  reduced  hKiDoglohiii  (or 
tare  briefly  iueaio{[lohin),  with  s  puri>l6  color  aix)  a  characteriuu!  one-bunded 
iftetnta.  «e  roean  h»tnoglob!i)  wliidi  ha*  lu»{  all  iia  lonely  Msitciated 
mygea.  If  a  <|uaDtity  of  osy-hRnidglohin  t>e  expowed  to  an  iniiulTicifiitly 
iam  pveMurc.  or  to  the  adioti  of  im  in.tuflicieiit  ijunutitr  of  tliv  retliiciiii[ 
leUon.  it  give*  up  a  part  only  of  Ui'  oxyfren;  it  in  only  jxirtly  rciluceil. 
ShH)  a  IwrtlT  n.'duccii  (ulution  still  shnw*  thv  Iwo  iMmtsofoxy-hienioglubiu. 
S  348.  Wlwn  the  hatmoglolun  wlutioii  (or  cryslul)  which  hiu  K>et  its 
iajgm  by  the  action  either  of  the  nir  pump  or  of  a  reducinj;  ngent  or  hy  the 
pMMgtOT  an  indilli^rvnt  gns,  is  expoeed  to  air  containing  oxygen,  an  nbeurp' 
doa  of  oxygen  at  oiioe  takea  place.  If  suflicient  oxvcen  ne  present,  the 
fc— inglnhin  aeiiee  upon  aufflcieiit  oxygen  to  obtain  its  full  compleioent.  each 
■laaHM  taking  op  in  comhinaiion  1.59  c.c.  of  oxygen  ;  if  lhen>  be  an 
MarfMeiit  qnaotily  of  oxygen  the  bn.>iuogl<>bin  still  remains  partly  reduce<l: 
or  pertia|»  we  mar  »ay  thai  a  juart  only  of  ibe  hemoglobin  gets  iia  allowance 
■  bila  ibe  remaiudor  contiuuea  leiluoed.  [f  the  amount  of  oxygen  be  auffl* 
cieM.  Um  tolutiou  (or  crvxal  I,  a*  it  takca  up  the  oxygen,  regaina  its  bright 
timiUi  ooloraitd  iia  characieristic  abaorption  spectrum,  ihe  single  band  heing 
iitilioul  by  the  iwo.  Thus  if  u  totulton  of  oxy-birinnglobin  in  u  tnl-iutie, 
■ner  being  rnlucnl  by  tlie  action  of  a  drup  or  two  of  ainnicmiuiii  nulphtde 
mlkatiim  and  thui>  itbowing  the  purple  nilor  and  the  nngle  baml,  Iw  «hake» 
m  with  air,  tbe  bright  acnrlcl  color  at  onc«  returns,  aixl  when  thv  Huid  is 
plaeid  btlhr*  ibo  epodroacopc,  it  is  anvn  that  the  sinslv  laiut  broad  hand  of 
ihe  ndnrrd  birmaglohtn  has  wholly  disapitearcd,  and  that  in  Ita  place  are 
the  two  sbarp  tbinm-r  linnds  of  tlw  oxy-hirmoelobin.  If  left  to  stand  in  the 
toC-tubr  the  <|(inntilr  of  tvducing  agfut  still  pn«.<nt  is  gem^mlly  niRicienl 
aMatn  t<i  nd>  iIh-  hii-Mi»glol>in  of  the  oxyg^^'U  thus  newly  acipiired,  and  noon 
toe  acKriel  hue  fade*  bacJt  again  into  the  ptirpic,  the  two  Itands  giving  idaov 
Lo  ibe  dUe.  AiHither  stmke  and  cxiHuure  In  air  will,  liowi'vcr,  again  bring 
Iwek  tbe  scarlet  hue  and  the  two  biin>t>  ;  and  once  more  ib(«u  niiy  dbappMr. 
In  &c<,afeKdro|Mtif  tbe  n-dut-ing  Hniil  will  allow  this  ^anM  of  hMmoKlobin 
uktBg  oxyceii  (r»ta  the  air  and  giving  it  uj>  lo  tlw  reducer  to  be  plnyM  over 

•  fs  l«vtUr*i  ■•>•  HBOMTcall  Uir  li'ii»«l»bln  MilaUiIna  iiiiBii  Ui  k<iiH<iiinlilBallv*,AnpAr- 
m^bb*  M>l  Ih* lu>*<f IuUd  rViiia  ahiili  titii  huKl;  cvniMbfil  iiDXn'i  li><  bBra  rriiH>TT>L (vlocnl 
kaaBaUtn  •>  d)i|<|  liBin>i«hriiin 


462 


RKSriRATIOK. 


ud  over  BOiQ :  at  meb  tiim  of  the  frnme  t)i«  ciilor  thifi*  from  Nmrlf t  lo 
{Hirplc, aixlfrutii  i>iir)i)i,>tu*c«rl«it,  wliifv  ihc  two  biintU «xc-biingv  for  the  uni, 
mid  the  niiu  lor  llic  Ini*. 

S  349.  (.iflor  of  vrnoH*  mid  itrltriat  klowl.  KviilcDllj  vc  luive  itt  thcM 
propcrlien  of  hicmogluliiti  nii  i-x|>laniition  of  at  Inut  oucOuilf  i>f  the  gTMl 
rwi>ir«tun>'  |>n)(.Ti«,  hihI  tboy  ttwL-h  u*  ilx'  iiinming  of  tlw  cbuigo  of  coW 
which  take*  I'laoc  u*h«n  vviixiis  MikuI  Ix^-imit*  iirk-rinl  or  an«rbil  veDous. 

In  venoiis  blooil,  a«  it  ifnn-n  tVum  iW  righl  ventricle,  the  oxygen  pr«wa( 
IB  iiuufficwnt  to  imti»fy  wliully  ihc  hirmoglotiin  of  the  rm!  corptiicl^e  ;  the 
hftnioglobin  a,  to  a.  largo  «xt«ul,  rediifvd,  htnic  the  purple  color  of  veiiaas 
bhxtd.  Wben  ordioary  venous  blood,  (liliiicil  wiihuut  acceu  of  osTgen,  ia 
brou^t  before  the  Mpectroecope,  the  ino  bonds  ot  oxy-bieinoglobin  are  wen. 
Tbis  is  explained  by  tbe  tnct  that  iu  partly  reduced  bwmoglobin,  which  we 
may  conveniently  regard  as  a  mixture  of  ozy-haemoglobin  and  (reduced) 
bKtuoglobin,  the  two  gliarj)  baDda  of  the  former  are  always  much  more 
radily  aeen  than  the  iiiui-h  fainter  baud  uf  ibe  latter.  Now  in  ordinary 
venoua  blood  there  is  always  nuoie  louae  oxygen,  removable  by  diminiahed 
prtwure  or  othern  ise ;  tiie  hwmoglobin  is  only  partlr  reduced,  there  is  alwava 
•ODi«,  indeed  a  considerable  (quantity,  of  uxy-bsmoglobin  as  well  as  (reducvcl) 
bttmuglobia.  Ii  is  oiilv  under  special  cin-umMancea,  as  for  instance  after 
dMttb  oy  what  we  mIihII  presently  !<i>eak  of  us  asphyxia,  that  all  Lbe  Ioom 
oxyno  of  tlie  blood  di-iappcuirw ;  atui  then  the  tiro  bands  of  oxy-hwrnoclobin 
vanub  too.  If  even  only  a  Miialt  (jUHnlilv  of  oxygi'n  he  prMent,  so  dtaiinct 
are  thi)  two  buuda  that  a  wiliiliou  »l'c«mpMely  nnluced  ha'inoglabiu  may  be 
utwd  HM  a  t<»t  for  the  presence  of  oxrici-n  ;  if  oxvgi^i  be  prrsrnt  in  anv  fluid 
to  which  thv  rt«luced  hucmogluhiii  m  iiddcd,  iliv  «i»f;Ic  Iwnd  immediately 
give*  way  to  the  two  blinds  of  oxy-h.-i-nmglobin. 

As  the  venous  blood  puwrw  thmueh  ihr  capillaries  of  tbe  lungs,  this 
reduced  ha-uioglobin  takes  from  thi'ptiTnionnry  air  its  complement  of  oxygen, 
all  or  Dcnrly  ul  Ibe  btemogloliin  of  the  m\  ci>rpiiH-lni  becomes  oxy-hmmo- 
globin,  and  the  purple  color  forthwith  shifts  into  K-urlct.  For  carefbl 
<^i«ervatioiu>  shon-  thnt  the  h:iMHogtubin  of  arterial  blood  is  saturated  or 
nearly  nturalcd  with  oxygen  :  it  probnhlv  falls  short  of  complete  saturation 
by  aliout  1  vol.  of  oxvgcn  in  lOU  volt,  of  blood.  Ry  increasing  tbe  pressure 
of  tbe  oxygen,  un  additional  (luautiiy  may  be  driven  into  tbe  blood,  but  this, 
after  tbe  nwmaglobin  hos  become  completely  anturated.  is  efleoted  by  Bitnf^ 
absorption.  Tbe  qunniity  so  added  is  extremely  small  compared  witb  lbe 
total  quantity  combined  with  the  hwmoglobin. 

Paaing  from  tiio  lel^  veolriclo  to  the  capillaries  of  the  tiasuee  the  oxy-ha>- 
noglobin  gives  up  some  of  its  oxygtn  to  llie  tissues,  becominf;.  in  part, 
reduced  lui-u)oj|;lobin,  and  tbe  blood  in  cunseijueiiee  beeomea  once  more 
veoous,  with  a  purple  hue.  Thus  the  red  curpusclee  by  virtue  of  thnr 
htnnoglobin  are  eoipbalically  oxyKeu-carriers.  Undergoing  no  iutriusic 
chniigfT  in  iisclf.  the  hieinoglobin  (M>ml>ines  in  the  lung*  with  oxvgcn,  which 
it  i-arri<^  tu  the  tinbues;  these,  mure  greetlv  of  oxygen  thau  itseltTrc^  it  of 
its  cliargf!,  and  the  reduced  luemoglohin  liiirriea  hack  to  llie  lunpi  in  tho 
%'enoUN  blood  for  unother  porlitHi.  I'he  change  from  venous  to  arterial  blood 
is  then  in  part  (for  as  we  shall  tiee  there  are  other  events  as  well)  a  peculiar 
combination  of  hiemoglobin  wtth  oxygen,  while  the  change  from  arterial  to 
venotiK  is,  in  part  also,  a  re<lunioii  of  Dxytiieninglobin  ;  and  the  diflV-rence  of 
color  between  venous  ami  uricnal  blood  de])eudM  aImo»i  entirelv  on  the  fad 
that  tbe  reduced  hiemoglobin  of  the  former  '»  of  ]>urjik  color,  while  tbe 
OXyJlRmoglobln  of  the  lutter  u*  of  n  scarlet  color. 

Thero  may  be  oilier  caiiffn  of  the  change  of  color,  but  tliesc  are  wholly 
subsidiary  and  unim|>ortant.     When  a  corpuM^le  tiweJIs,  it  refrmclivc  power 


TUB    RKSl'lRATOltV    CIIAN'OE!}   IN  TUE  BLOOIt. 


4dS 


I 

I 

I 


I 

I 


u  diniininubcd,  imd  id  cwiiiequMice  tbi.'  numlwr  vf  rap  which  piMt  iiitu  tsui 
are  abeorbed  by  it  nrc  invrcnsctl  at  tb«  PX|«nM  of  ihuw  ruflccli^l  rnxii  iu 
•UfAeo ;  anyliiing  iht^rcfurc  vrhich  iiui-Dk  the  corpiji>cJn,  »wh  tu  iW  ii<ii)itiMii 
of  nntor,  ten<l»  tu  durkeo  tilood,  and  uiythiag,  «ucK  •»  n  c^iccutniCed  siiliiie 
tuliitiuii.  wtiicli  ntitcs  th«  corpUBcInf  tu  shrink,  \em}*  to  brighten  blootl. 
Ckrbonic  iicid  hii«  npfmrcDtly  i>»m«  inllucuce  in  swdling  tUe  ocirpusclee,  mid 
tberalbrv  muy  nid  in  durkcniiig  tho  veiiotM  blood. 

^  360.  W«  biiv«  epokcn  of  (ho  cxmibinution  of  hiMtiQKilobiR  with  oxjgea  as 
beioK  «  peculiftr  oae.  Thi>  pcciiliiu-ily  conaats  in  the  facta  i^nt  tb«  vxyiiea 
tDBT  M  Mtociated  niid  difsocintcd,  without  tiny  (fcncrnl  disturbauie  ol  Uie 
tDoWOole  of  hieiDoglobiH,  and  that  disHidBtion  niny  be  brought  nbniit  very 
readily.  Hnmoglobin  combinw  iu  a  wholly  similar  QiaDn«r  with  otker 
Kases.  If  carbouic  oxide  (monoxide)  be  passed  through  a  sxluliDU  iif 
flseotoglobiu.  a  chsnge  of  color  lakes  place,  a  peculiar  bluisJi  tinf,'«  making 
ita  appearance.  At  the  bame  time  the  s^ieclrum  is  altered  ;  iitu  bands  are 
Mill  visible,  but  ou  accurate  measurement  it  U  seen  thai  tbev  are  placed  more 
toward  die  bliie  end  than  are  the  uthcrwue  similar  bands  ui  uxy-nieinoglubin 
(see  Fi);.  137,  ti>;  tlieir  centres  oorrw|>aiidiug  respectively  to  about  wave- 
len^ctlis  oi'i  and  r>3:t,  while  thuei^roxy-hffiiDuglubin,  as  ire  have  weii,  corrc- 
.ijMnd  tu  578  and  539.  When  a  known  quantity  of  carbonic  oxide  ens  is 
•ent  tlirough  a  httaioglobin  nulution.  it  wilt  bn  found  on  examiuHtion  triat  n 
certain  amount  of  the  fiai>  him  brcn  n^tninrd,  nn  c<|iial  volume  of  oxygen  ap- 
pvariog  in  iti  plait- in  llic^nii  wtiirh  imum  from  the  solution.  If  llie  solution 
su  treated  ht  cry»Iiiili/x^l.  i\\v  ■rplnlj'  will  have  the  mmc  cJiaracteriatic  color, 
and  give  the  eamu  ahmtrption  Kpi.-clnini  us  the  solution ;  when  subjeeted  Iu 
tha  action  of  tlw  mercurinl  pump,  tht-y  will  eivi-  off  a  delinite  quantity  of 
cnrbonic  oxide,  1  grnminc  of  the  eryiflnU  yirlditig  l.'>9  c.c-  of  the  gns.  In 
fact,  hwmoglobin  uoDibincs  loo«ely  with  carbonic  oxidr  just  ns  it  aoea  with 
oxygen ;  but  its  affinity  with  iho  former  is  greater  than  with  the  latter. 
SVnilfl  carbonic  oxido  nwdily  turns  out  oxygen,  oxy^o  cannot  so  readily 
turn  out  carbonic  oxide.  Indeed,  nirbonic  oxide  has  been  used  as  a  means 
of  driviiyt  out  and  measuring  the  -iiiiflntity  of  oxygen  present  in  any  given 
blood.  This  property  of  carbonic  oxide  explains  its  poisooous  nature. 
When  the  gas  is  breathed,  the  reduced  and  the  unreduced  unmoglohiu  of  the 
venoua  blood  unite  with  the  carbonic  oxide,  and  hence  the  peculiar,  bright 
cherry-red  color  observable  in  the  blood  and  tissues  in  oases  of  polsoningliy 
this  gas.  The  carbonic  oxide  hterooglobin,  however,  is  of  no  use  in  respira- 
tion ;  it  is  nut  an  oxygen -earlier,  nay  more,  it  will  not  readily,  though  it 
dooBso  sluwljr  and  eventually,  give  up  its  carbonic  oxide  for  oxygen,  wlx'u 
tbe  jioiiiODoiia  fpe  ceasea  to  enter  the  oDen  and  b  replaced  by  pure  air.  Thi; 
orgabisro  is  killed  by  suSbcalion,  by  want  of  oxvgen,  in  unite  of  the  blood 
not  aaaumlBg  any  darlc  venous  color ;  to  adopt  a  ]>t)nuR  which  has  been  used, 
the  corpuscles  arv  pnrul^  »cd. 

HiCDid^loliin  Miuiiarty  fortiiit  a  com[H>inH',  having  a  characteriiitic  spec- 
trum, with  nitric  oxidr.  more  stable  cvi-n  than  that  with  carbonic  oxide. 

It  has  lieen  suppowKl  liy  H>me  thai  the  oxvgen  thus  iuw>cialcd  with  hnnio- 
globiu  Is  in  the  condition  known  n»  unouv;  f>ut  thv  arguntents  urged  in  »ui>- 
port  of  this  view  art  iucoiiclusivc 

J^rvdttcts  of  the  DtfQmpontimt  of  Hamtujlobin, 

g  961.  Although  a  crystalline  body,  haunoglobin  difllises  with  great  ditti- 
ctilty.  This  arises  from  the  tact  tJiat  it  is  in  part  a  proteid  budv  ;  it  con- 
sists of  a  colorlew  proteid.  aMocialeit  uiih  a  colored  KulMianre,  w^ich  may 

separated  out  from  the  fawmoglobtn,  though  not  in  the  exact  con<iitio»  in 


RKSPIBATION. 


I\'  exisl«  in  lh«  corapoiin'l :  tliu  subtfanM  wh«n  HpnnilMl 
BfeDvnt'h-re)!  hoily  known  tin  turm-tliii.  All  rite  iivin  b«- 
pnglobiii  i#  ill  ivttliiv  nitnclietl  to  th«  liicninliu.  A  eolutioo 
tvh«D   heatod.  coagtiliitc«.  tbe  rxaci   decree   at  wbiclt    tli« 

place  (le^ndini;  on  ttie  amount  of  dilution;  at  tli«  bame 
rti  from  the  seKiiig  free  of  the  hwinaiin.  If  a  Btronc  •olu- 
tin  be  Ireaioil  with  acetic  (or  oiherj  aciO.  the  tame  nrown 
ppenrance  uf  hseinatiu,  a  observed.  Tbe  proleid  codmUu- 
lot  coagulated,  bui  by  the  action  of  the  acid  i)a&«t  Jntu 
kibuiuin.  Un  itdditi};  ether  to  the  mixture,  ami  tbeikins. 
3J9Molv<!il  ill  tbe  supernatant  acid  utbcr,  irhicfa  it  colon  a 
ich,  lixnmined  nllli  tlit  «[iecti>uroi)e,  iit  f»nnd  to  p(M»e**  ■ 
truin,  ilie  Hiieciruiu  of  the  it»-culle(i  acid  liicmniin  i>t  Stokts 
'he  proU'id  111  thv  water  Im-Iow  the  ether  appeani  in  a  ci>a|^- 

to  the  action  of  thi'  eihcr.  In  n  .■"uncwhnt  nimilnr  maniter 
.in^mo^dubin  into  a  prot«id  cnnrtiturnt  and  b»nMtin. 
ire  of  ihn  jirotfid  coiistiliiwit  nf  bipmoglobin  ha«  nol  a*  yet 
rtiiinol,  11  wiw  "ujipoiii'il  to  be  globidin  (hcnco  lb*  itaiiH- 
conlractcd  int^  biemoglobin),  but  ihoiieb  belonging  lo  the 
has  ch.iractcre  of  il«  own  ;  it  is  poHibfy  a  miiture  uf  iwu 

proieidB.  It  ha«  been  proviiiionally  named  fftobut  and  i» 
)iu  ash. 

n  wbcn  Bcpnrnted  from  it*  proteid  fellow,  and  purified, 
rk-bi'owu  amorphous  powder,  or  aa  a  sualv  mav  with  a 
iving  the  probable  ooniposilion  of  C„,  H„.  N,.  Fe.  O^.'  It 
n  dilute  acid  or  alkaline  solutioas,  and  then  givee  ctiarac- 
i-ig.  13M,2.ft). 

fvatiirc  ill  hwniatin  it  that  Its  afhtlwe  solullim  ia  ca[Mible 

by  rcdiK'itifT  agent*,  tlit'  Mpealruni  changing  ai  lh<-  Mnte 
),  and  that  the  r«.-diicc'l  solution  will,  lik«  iho  bieitiogldbin, 
Igain  on  being  brought  into  contact  with  air  or  oxrnu. 
to  indicate  that  the  oxygen-holding  power  of  hamogiooiD 
uivoly  with  ile  haiiiiniin  con'titucnt. 
)f  strong  eulphurie  add  btNoatin  may  be  robbod  of  all  its 
liDB  the  feature  of  poowwng  color,  the  solution  of  iron-free 
dark  rich  browni^h-rcd  :  but  is  no  longer  capable  of  com- 
tli  oxyeen.  This  indicates  thai  tho  iron  it  in  tome  war 
be  pei'uliar  respiratory  functions  of  hntuo^lohin  ;  tl)oti;>n 

error  to  suppose,  as  was  once  suppooed,  that  tbe  change 
ierial  blood  consista  easentialty  in  a  change  from  a  ferroua 

MalUnblB  itaelf,  biero&tin  furnis  with  hydrochloric  acid  a 
ring  In  ntlnote  rhombic  cn'stals.  known  as  hixmin  cry^lala. 
I  left  until  it  decomposes,  the  haerooglohin  is  very  apl  to 
Bto  a  ptTuliur  boily  linowu  as  meilnrmoglobin,  in  the  apec- 
vcrr  coiixpicnou-i  band  i.i  Keen  in  the  red  between  rnnd  D 
"the  same  change  may  be  bri>U);ht  about  by  the  action 
ch  as  carbonic  acid,  by  ozono,  an<l  iiy  other  agetili  «uch  n* 
pKBi  pcrmaneaiialc.  When  a  strmin  of  rMTlMnic  add  is 
pm  or  through  a  solution  of  hiemoglobin  tb«t  baad  In  the 
of  meth:cmogk>bin  soon  mnkc*  it«  appearance.  Mvtb«f 
rat  little,  if  at  all,  in  wlcmpiilary  composition  from  biemo- 
Dtained  that  it  coDlains  the  Mime  <|uantity  uf  oxygeii  aa 

Mil  4UW "f  llap|<«.7vylat  ^  Ui>tKi*««>"  )Ui.U Hid  niMe (Moat  auAfnteUr 


4m 


REitrlH^TlaN. 


oxj-hwcnoKlobiii  but  in  a  more  stable  ooodition,  nore  iatinuudy  asBocimH 
with  the  molecule. 

Ill  ctitid  union .  the  c-oiiililion  of  oxr^eu  in  Lite  blixxl  b  lu  fuUtfirs:  Of  ilw 
whole  ((iiaiitily  of  oxy^u  In  the  bluud,  only  a  minute  fractirm  En  siaplj 
ilbitorlwd  ur  ili.iniilved  ai-i.-ur'litiK  to  the  Ixw  of  |ireitiure«  (tlie  Uoory-DnlloD 
law}.  The  gtcal  iiiiLw  in  in  astute  of  combination  with  the  hnmoglobiD, 
the  cunn«cti«ii  being  of  wieh  »  kind  that  while  the  licnKif[lobiu  rcadilr 
combine*  witli  the  oxygen  of  the  air  ta  which  it  it  expoacd,  diMariatioii 
rcni]ilv  octrurH  at  lnw  pn^KiUKu,  or  in  the  [ireM^nce  uf  indilrercnl  gium,  or  by 
the  iiclion  iif  ^iilMliinrist  having  u  lerenler  afBnily  fur  AXyj^n  than  has  hirmo- 
globin  it^t'l)',  Tlic  (lIir<'n'n(N-  ln-lwucn  veiiou*  and  arterial  Muih),  tu  far  m 
oxyeoQ  \t  I'lmt'ernvd,  in  that  while  in  arterial  blood  iho  hn-niogloMti  hoUi 
nearly  its  lull  oomnlemuot  of  oxTgrii  and  may  lie  >|>i>ken  ufiks  nearly 
wholly  oxy-hirmoglobin,  in  Tonoiiii  blood  the  hn'tunglobtii  \a  to  ■  lar^-  bat 
variable  extent,  nxluccd ;  and  thu  cbumoterixtic  uniors  ol'  rcnoui  iin'l  arte- 
rial blood  are  in  the  niiiin  due  l<i  the  fact  that  ihp  color  of  reduced  hsnw 
globin  is  purple,  while  that  of  osy-hiem»gM>in  is  scarlet. 

T^e  Jteiailoni  of  Ihe  Carbonic  Atul  iit  tic  Blood. 

g  363.  Tlie  umence  of  earbonic  acid  iu  the  blond  ^)>ear»  to  he  di.'Ur-  — 
mimed  by  conditlonit  more  oomj>lex  iu  tlieir  nature  and  at  proient  not  eo  well 
underatoiMl  a.i  thu«e  irbidi  deierdiinc  the  prcaencc  of  nxygi'ii.    Tha  ntrbonic  = 
acid  is  iK't  »imply  dixtiilvf.fl  in  the  blood ;  itit  alMiirplinn  by  blood  diira  noL^ 
follow  the  law  af  prci«iirc-'>.     It.  t^xi^ta  in  iwwii'ialii m  with  Hi>mc  »iib«tanoc  tr- 
eubetonenf  in  the  blnoii,  and  its  wcapcs  fmni  ihc  lihiiid  io  a  pnicivs  of  disM— 
ciatiun.     We  cannot,  howerer,  iipeiik  ft  ii  iw  beini:  KK«K-iHte<l,  to  the  MniB 
extent  aa  is  the  oxygen,  with  llic  hienioglobin  of  the  rrrl  oorpiwclea.     &» 
far  fruui  the  red  corpuscles  cootaiDing  the  grvat  mass  of  ili«  carbonic  add, 
the  ({uantily  of  this  gas  which  is  present  in  a  volume  of  serum  is  aceurdiug 
tu  Home  ubtervers  actually  greater  than  that  which  is  pre«nt  in  an  *.i)ual 
volume  of  blood,  i.e.,  au  ecjual  volume  of  mixed  corpuscles  and   Merum: 
thai  is  to  »ay,  the  carbonic  acid   is  much   more  largely  aaiooiatcd  with 
theverum  (or,  in  the  living  blood,  with  the  plasma)  than  with  the  red  ntr- 
pusdea. 

Wheu  Rcmni  is  siibjecled  to  the  action  of  the  mercurial  pump,  by  far  tlx 
greater  part  of  the  carbonic  noid  is  given  off;  but  a  small  additional  ijuan- 
llty  (2  to  ^  vok  |)erc<tnl.)  nmy  be  extracted  bv  the  lubsetiuent  iiddiiion  of 
an  acid,  Thii-  latter  portion  may  be  spukt-ji  of*  a^  "  fixed  "  carbonic  acid  in 
distinction  lo  thr  laigrr  "  looM ""  portion  which  b-  given  off  lo  thv  vacuum. 
When,  however,  iho  whole  bloiHl  vt  suhjwted  to  the  vacuum  until  the  car- 
bonic acid  ccasM  to  ho  given  "If,  ihe  Mibfeqitunl  addition  of  arid  i»  said  not 
to  eet  free  any  ftirtlicr  quantity  :  so  (Jiai  when  K^riim  in  mixed  with  cirnusclea 
idl  tbe  carbonic  arid  miiv  Im-  spoken  of  as  "  kmav"  :  and  it  i*  stat^id  that  the 
excess  of  carbonic  add  in  ■  quantity  of  serum  over  that  pretenl  in  tlie  aatue 
bulk  of  entire  blood,  corresponds  to  tho  fixi.'-l  [loriiuu  in  snrura  which  has  to 
be  driven  olT  by  an  acid.  Moroovcr.  even  ihooe  who  maintain  tlint  the 
quantity  of  carbonic  acid  iu  entire  blood  >*  Imh  than  that  in  an  equal  volume 
of  nrum,  admit  that  the  carbonic  acid  vxistii  in  N'>mc  way  or  other  at  a 
higher  preeuire  in,  and  is  more  readily  given  olf  from  eatire  blood  than  frum 
serum. 

If  tli«M  BtatemenU  be  aceepted  it  seem!  iirobablo  that  the  cartMuic  acid 
exiua  aMOciated  with  some  suMtauoe  or  sulMlanci^  in  the  eerum,  or  rather 
l>IasiDa,  but  that  thecondillooaof  itaasmoiation  (an<l  thereof  iudiMociaiiao} 
are  dcUrmined  by  tbe  action  »f  some  Bubaiauce  or  subitauces  present  in  ih« 


RBI 


467 


«orptiecl«£.  It  has  been  suggMted  tliat  ibe  aMociaii»i)  uf  tbe  «Hrl>uniQ  m-id 
ID  Oie  p|[u>ma  b>  with  one  or  other  of  tfa«  proteida  of  ilie  plaaiua^  but  it  ba« 
alao  been  eu;-i;t«i«Hl  that  the  turaciatioD  ia  one  with  eodium  a.i  »oiIiut)i  biunr- 
bonate,  and  further  ibat  tU«  hnmoj^lobin  of  the  corpuDelen  [itay!i  a  iiart  iu 
promoting  tJie  diasodalion  of  the  Htdium  bioarbonate  or  ewn  the  caruoiiaic, 
and  tbu»  keeping  up  di«  carbonic  acid  of  tlic  wtirc  blooii.  Oilier  obwcrver*. 
bowever,  mamtatn  that  the  plaania  doe*  not  holii  Ihin  ex<!tuNiv<!  po««won  of 
the  carbonic  aoi<l,  but  that  a  ci)UNi<lcrab]«  miaiirity  uf  iliUi  ^aa  \t  iii  mmv  way 
•taociated  with  the  ml  corpii*cti.>«.  Iiii]<«<i,  ftirilicr  iiivwugatioiu  arc  n«coa- 
Han,*  hcri>re  tho  matter  van  \k  mill  to  have  l>ecn  plimd  on  a  satisfactocy 
foot  I  tig. 

7'A«  IMatianM  nf  the  JffUrogfn  in  (he  Jtlotxl. 

i  304.  The  email  quantity  of  tbia  j^as  whi4:li  a  present  in  both  arK-rtal  and 
veiUMia  blood  aeemi  to  exist  in  a  state  of  simple  eolutioii. 


The  Rr.4i*titATi)RY  ('iianoi»  is  tiie  Liinim. 

The  KttlniMfe  of  Oxytffn. 

i  353,  \V«>  hnvp  already  twn  ihal  the  blood  in  paxtin);  through  the  lunga 
lakee  up  a  certain  variable  oiiaiititir  {from  H  to  1*2  vols,  per  cent.)  of  o.ty^^. 
We  have  further  wen  that  the  quantity  hi  taken  up.  putting  aside  the  insijf- 
niflcant  fraction  dimply  absorbed,  cnterB  into  direct  out  loooe  tiombiualion 
with  the  b»m (■(;'** bin.  In  drawtng  a  distinction  between  the  oxy;:;en  simply 
alMiirheil  and  ibui  enterinc  into  coiubinatioa  with  l)ie  lueaioglAbln,  it  must 
itot  be  understood  that  the  latter  is  wholly  independent  of  pressure.  On  the 
contrary,  all  cJientical  compounds  are  in  various  den^reas  subject  to  diieooia- 
U(in  at  certain  pressures  and  lenii)eralur«4;  and  the  exutenoe  of  the  aome- 
vfbat  loose  Gorapouod  of  oiygen  and  buuo^Iobin  is  dependent  on  the  partial 
prtaiure  of  oxygen  in  the  atmosphere  to  which  the  hKnioglobiii  i»  ex]>0Md. 
ifol  only  will  a  suliition  of  hiemc^lobin  or  a  auantilv  of  blood  citlier  ahnrb 
oxygru,  uud  thus  undergo  aa»cialion  or  unaergodtmociulion  and  give  off 
ox'ygL'ii  According  t»  the  [lartiul  preaaure  of  oxygen  in  tlie  a  tin  imp}!  ore  to 
vrbicli  it  t»  expiiabd  ia  high  or  Inn',  but  alto  th« amount  taken  up  or  eiven  off 
will  df'piMid  i>D  the  d^rvM  <>f  the  jiarlial  iinMurs;  the  hatmoglobiu  as  «• 
have  tixn  may  be  partiallv  an  well  an  wholly  reduond.  Tho  law,  how«r«r, 
acojrdiii);  )••  which  abwirpli'm  or  nicape  thus  tiik<«  place  it  '{uitc  diflerent 
froni  thai  olNUTved  in  the  simple  alMorptimi  of  oxygen  by  liquiii*.  The  aara- 
ciation  or  dimiiciatioo  b  fiirtbormpoeialty  dv[H-ndent  on  tMnpcrnlure,  a  hi^ 
temperature  favoring  diiwociatifln,  ao  (hat  ul  a  high  tomperature  laea  oxygen 
is  taken  up  than  would  be  taken  up  (or,  a*  the  ciuc  may  Ixi,  niore  gtraii  off 
titau  would  be  given  off)  at  a  loner  temperature,  the  partial  preaaure  of  tbe 
oxygen  in  the  Btin<a|ilMTc  remaining  iho  oamo. 

Moreover  in  the  liloud  ne  bare  to  deal  not  with  hicmoglobin  in  simple 
wolution.  in  which  tho  moJecuIca  are  dispersed  uniformly  through  the  solvent, 
but  with  the  humoglobiu  aegregated  into  minute  isolated  maaees,  battled  up 
iin  it  were  in  the  individual  oorpuHcles.  The  hwrnof^obin  of  each  corpuscle 
is  aeparatef)  from  ile  fellows  by  a  laver,  ihin  it  may  be  but  still  a  distinct 
layer,  of  colnrleas,  bwninglobinles^  ptasma.  As  the  corpuscle  makes  its  way 
through  live  narrow  eapillary  paths  of  a  pulraonar^,'  alveolus,  it  \a  s^karated 
IVoHi  l)ic  air  of  Uie  alvtvolua  by  a  thin  layer  of  plasma  a^  well  as  by  tbe  film 
of  dm  ooDJoiued  capillaiy  and  alveobtr  walU ;  and  a  like  layer  of  pi&tmia 
aopantiot  it  from  its  Iclluws  us  it  journeya  iu  company  with  them  through  the 


466 


RKSflRATION. 


wider  pawy  of  the  arUrin  aud  veins.  Through  tlib  layer 
iibidi  conMuttng  no  luemofclobtn  ma  holil  oxyxeii  in  siiiipln  iuhiUun  nnlj, 
Ibe  oxygeu  has  to  jtam  on  lU  wfty  t<>  ■»•!  froui  the  corpuade ;  ud  vverv  cor- 
|himIc  may  be  ci>iiaidered  as  ^veniiuK.  ns  Car  as  oxy^n  b  oonvemed,  n  xone 
uf  i>lHSuia  imiii^ilialely  HurroundiBg  iudf.  Tbe  corpusck  uk**  iu  oxyg^ii 
directly  iVuin  this  taao  hikI  gire*  u|>  il«  oxy^u  ilireotly  ki  thi«  xono;  nod 
the  pKwiire  at  which  at  any  momisit  the  oxygea  cxhU  in  this  lone  will 
dapend  mi  the  prenumif  osyKttni>uUu)i;the  x(>lH^,  in  th  airof  thepulmonarj 
nWeolun  for  iiistaiK-c.  him)  i>n  lh<^  Kniallar  or  grvnter  nmoui>l  of  oxygMi 
«M()ciat«(l  with  the  hn'miiglohin  of  the  curj>u«flc 

The  film  of  tho  c<u)j<)inc<l  cnpillnn,'  nnd  alveolar  wall  u  a  thiD  membrane 
soaked  with  lym^h  and  wet ;  tre  caunot  speak  of  it  a*  ac4uallr  secretins  a 
li(]uid  wrretiuii  into  th«  alreoluit,  for  the  cariiy  of  the  alveolus  is  filled  with 
air  which,  though  saturated  with  OHUsture,  is  air,  not  a  liquid  :  still  enoucfa 
paw«s  through  the  film  to  ke«p  it  oonUoually  moist.  Throui^h  this  film  t&e 
oxygen  has  to  make  its  way  in  order  to  g,iua  accem  to  the  plasma  and  »o  to 
the  corpiiselo;  it  makes  lis  war  dissolved  in  the  fluid,  that  is  the  lymph, 
which  keeps  the  film  moisL  This  film,  moreover,  is  comjxieed  uf  liviiiK 
matter,  and  the  con^derations  which  a  little  while  twick  li  3i:{)  w«  ur;^ 
concerning  the  difllbaion  throufh  a  Uvint;  membrane  uf  wjUiI  »ubstancea  in 
solution,  hold  good  also  for  the  ditltuion  of  Rases  in  solutiim. 

We  have  now  to  consider  tlie  queelion,  Arc  the  conditions  iu  wbiob  ha»DO< 
globin  and  oxygen  exist  in  ordinary  venous  bliMvl  b.i  it  fluwn  to  tho  lungs,  of 
such  a  kind  that  (he  venous  blond  in  pairing  ihrongli  tliv  [iiilmonary  captl- 
Uit\(*  will  find  the  partial  prwsure  of  the  oxyg<-n  in  the  pulmonary  alveoli 
.lufiicient  to  bring  about  the  niMciciation  of  llic  additionnl  ijunntity  of  oxygm 
whereby  the  venous  is  (x>nvertwl  into  arterial  hlooil? 

We  mar  say  at  i»nce  that  we  haip-c,  at  prwent  at  all  events,  no  witufnetory 
evideoee  Uiat  (he  film  spoken  of  above  exerts  any  influcnec,  w  a  living  film, 
on  tho  entrance  of  oxygen  from  the  alvcoliu  into  ih«  hlood.  Nor  have  we 
any  evidtmcc  that  u#  a  mere  membrane  or  septum  it  exerts  any  such  influ- 
ence :  (he  oxygen  appears  to  pass  into  the  blood  in  the  same  way  that  it 
would,  if  Ihe  blood  were  freely  exposed  without  any  intervening  partition  (o 
the  alveolar  air.  Further,  the  eridenu'e.  so  fur  as  it  g<Mw.  seems  to  show  that 
blood  absorbs  oxy^n  in  the  same  way  as  an  aqueous  solution  of  hjeotoglobin 
of  Uie  same  coooentration ;  the  zone  of  plasma  spoken  of  above  as  surround- 
ing each  corpuscle  behares  as  far  as  regards  the  passage  of  oxygen  to  and 
ftooB  the  corpuscles  in  no  caaentially  different  respect  from  the  way  the  mole- 
cules of  water,  belonging  to  a  molecule  of  dissolved  hemoglobin,  behave  in 
regard  to  the  absorpliou  or  the  giving-ulf  of  oxygen  by  an  a<(ueau8  solution 
of  hiemoglobin, 

li  394.  In  man,  aa  we  have  seen,  expired  air  contains  about  16  per  cent,  of 
oxygen.  The  air  in  the  pulmonary  alveoli  must  contain  lets  than  this,  ainoo 
lite  expire<l  air  connisls  of  ti<bil  air  mixed  by  dilTuiuon  with  the  stationary 
air.  How  much  lew  it  ei>o(nin«  we  do  not  exMitly  know,  hut  prohuhlr  (he 
dilferenre  is  not  very  great.  At  the  untinary  atmunphenc  premure  qI  760 
mm.  Iti  fter  cent,  is  e<(uivalent  to  a  purtinl  prcMiure  of  122  mm.  The  ques- 
tion, (htri-fore,  stands  thus.  Will  venous  hiooit.  expiisecl  at  the  teni[)erature 
of  the  h»dy  to  n  partial  premnrc  of  liM  than  122  mm.  (less  than  Id  per 
cent.)  of  oxygen  tiikc  up  sullicit^nt  oxygen  i  fn>m  8  t«  12  vols,  per  cent.)  to 
convert  it  into  arterial  blood?  Numerous  cxpvnmvnis  have  )>«>pn  mode 
(chielly  hut  not  exclnsively  on  the  dog)  to  detonuinc  on  the  one  han<l  the 
oxygen- pressure  of  both  arterial  and  venous  blood  (t.  c,  thi>  parlinl  prcssnre 
of  oxygen  in  an  atmosphere  exposed  to  which  the  nrtcrini  blood  neither 
gives  up  nor  takes  in  oxygen,  and  the  same  for  venoti*  hlcxKl),  and  on  the 


i 


TUK    ItESflRATORY    CIIANQKS  IN    THE   Ll'XGft. 


I 


■     not 


other  bwul  tbi*  beliiivlor  nl  tlio  t«ni|>eralure  nf  itie  budy  or  ni  onliimry  t«n)- 
pomturai  of  UIoihI  or  of  toltitioiu  of  hicptoelolrin  (for  the  (wo  o»  we  hiivo 
jiiM  snid,  bdiiivv  iti  this  respect  very  mtiuh  nliko)  towttn)  on  fiti)i<i«ph«rc  ill 
which  the  pitrtitil  praBura  of  oxygea  u  made  o  viirv.  Without  going  into 
di-tnit,  wv  may  state  that  these  eixperimenta  shmr  thnt  the  nnrtial  prt«ura  of 
oxygen  in  the  Iiingv  is  amply  sutHcienl  tn  bring  about,  at  the  tctnpcratura  of 
(ho  body,  lh«  awociatioii  of  that  nddilioiial  amount  of  uxyceu  hr  which 
WIWU8  blood  beoomM  arterial.  When  a  solution  of  btemogiobin  or  when 
blood  is  suoDearively  expoced  to  increasing;  oxyg«n  pr«wura,  as  the  partial 

grcmiirv  of  oxygen  is  gradually  increaned,  the  curve  of  absorption  nsos  at 
rat  very  rapidly  but  aAeruard  more  slowly ;  that  is  to  say.  the  latter  adili- 
tione  of  oxyjten  at  the  hijtber  ])rewiirea  are  proportionately  leas  than  the 
rlier  ones  at  the  loner  prewunw.  And  this  is  consonant  with  wliat  appears 
be  Uie  Imcl  that  tlie  hwroo^loliin  of  arterial  blood  (bough  nearly  Batumted 
itb  oxygen,  ■'.  c,  aajuciated  with  alinori.  its  full  complement  of  oxygen,  is 
not  quite  caturated.  When  arterial  blood  is  tlioroughly  exposed  to  air  it 
lakea  up  rather  more  (ban  1  vol.  |ier  <«nt.  of  oxy^^en ;  and  that  appean  to 
represent  ihc.  difference  be1«eeii  exjMving  bloml  to  pure  air,  nuch  an  e:itenor 
ouKht  to  enter  ibe  mouth  in  inspiration,  and  expiwin);  Uloixl  to  llie  air  an  It 
exislHin  the  pulmonary  alv<»ili.  The  greater  rclnlive  ulixorpliiin  at  the  lower 
preaturen  linn  a  bvnelicial  cflcct  iniiNnmch  uk  it  !>tin  rx^riultx  a  (!iin»iil«nible 
quantity  of  oxygv-n  to  I>e  nlwrlMHl  evm  ulicn  lliu  [Hirliiil  pr)rfi>iire  ot'oxygco 
in  the  air  iu  the  luiigx  is  lureely  reduced,  as  in  aw^ndin^  to  gmat  hcighCi*. 

Obwrvations  made  both  witb  dog's  Mood  and  «xV  blood  worn  to  sbon  that 
arterial  blood  i-va^n  to  take  up  oxygen  and  begins  to  giro  oil'  oxygen ;  in 
otJM!rwor>U.lhnt  dixnMocintion  begins  to  take  place ^rhen  the  partial  prmHi re 
of  ihv  oxygen  in  the  atmosphere  to  which  it  is  exposed  sinks  to  n1>t>iit  IHI  mm. 
of  mercury- ;  that  is  to  sav,  when  the  whole  atmospheric  prcMUre  i»  rwlticed 
fnmi  764)  mm.  to  about  SUO  ram.,  or  when  the  percentage  of  oxygen  in  the 
ntnt<«pherc  is  reduced  by  decidedly  more  than  half  And  this  accords  with 
the  observation  tliat  in  man,  when  the  oxygen  of  inspired  air  is  gradually 
diminished  without  any  other  change  in  the  air,  symptoms  of  <lyBpncea  do  not 
make  their  ap[iearance  until  the  oxygen  sinks  to  10  per  cent,  in  tlie  inspired 
air,  and  must  therefore  be  l«a  than  this  in  the  pulmonary  alveoli.  Wa 
may  remark  that  at  ordinary  altJtudee,  eTeo  taking  mto  auoouiit  (be  diminu- 
tion the  oxygen  undergoeH  befure  it  reacbea  the  pulmonarv  alveoli,  the  partial 
prenure  of  the  oxygen  in  Ihe  ntmosphere  leaves  a  wide  tnaruin  of  safety. 
But  at  an  attitude  of  5o0i)  metric  (17,00ii  feet),  at  which  the  preesure  of 
tlte  wltole  aLmcephere  .itaiKln  at  almut  the  limit  given  above  of  :iOO  mm.,  the 
|,>lMrtud  prewure  of  the  oxygen  will  be  Mich  that  tlie  veuoUH  blood  mnnut 
nke  up  the  <|uantilviif  oxygcJi  pniper  to  convert  it  into  arterial  blood,  Miice 
at  thiH  limit  iirlerial  blixid  Tit^iun  to  give  off*  oxvgen.  \V<-  may  mid  tlinl  it 
is  at  tbio  altitude  that  breathing  l>eoomce  especially  ditHcuit,  but  lo  this  we 
idiall  retuni. 

§  357.  Tbo  statements  nuulc  so  far  refer  to  ordinary  breathing,  but  the 
(|a<aiiou  may  be  aj>kcd.  What  hap|)ei»  when  the  renewal  of  ilie  air  in  the 
pnlmoimry  alveoli  ceases,  as  when  the  trachea  is  obstructed?  In  such  a 
caw  tlH-  oxygen  in  the  alveoli  is  found  to  diminish  mpidly,  so  that  the 
partial  pressure  of  oxygen  in  them  soon  fnlls  below  the  oxygen-preestire  of 
onlinary  venous  blood.  Bui  in  such  a  case  (he  blood  is  no  longer  ordinary 
vanoua  blood  ;  instead  of  being  roodentlely,  it  i;>  largely  and  increasingly 
leduced ;  instead  of  containing  a  compsrativelv  small  amount,  it  cuntains  A 
llL^^  and  gradually  iDcrauing  amount  of  rei^uced  hwmoglohin.  vVnd  M 
the  redut^tiou  eontinuce  to  iDcreoM.  tlte  oxTgen-pre^ure  of  the  venous  blood 
also  continues  to  decrease ;  it  thus  keeps  below  (bat  of  the  air  in  the  lungs. 


470 


Hi-tipc.  apparcnily.  even  ilie  Ia*t  trnt-ee  of  oxygea  ia  ttie  Iudj^  ni«jr  be  takra 
nj'  by  the  bldotl  and  varrkil  away  tu  ihe  li«u«ii. 


The  Erll  o/  Carbame  Add. 


4 


th^. 
obyj 

USOCf 


!f  356.  It  m-env  imtiiriil  to  KUpmi^c  ihni  the  carbonic  acid  would  otoapr  hv 
(lifTiiftinii  Irom  the  bloud  of  the  Mveolar  rapillari^  into  llio  oirol'lhc  alveoli. 
But  ill  order  (hat  diRbsion  should  thus  lake  place,  the  carlMMiic  acid  prcwuiv 
of  the  air  in  the  milmonarr  alveoli  niual  always  l>e  leaa  tliaii  tltat  of  llio 
venoiia  blood  of  tnc  piilnionary  arlcry,  and  ouglit  Dol  to  exceed  tbnt  of  tbe 
blood  of  tbe  piilmonury  vein.  There  are,  however,  many  practical  diffi- 
culiies  in  tbe  way  of  an  exact  detenniimiioD  of  iLe  carbuuto  acUi  preamire 
of  the  paltnooary  alveoli  (J'ot,  though  it  muKt  be  greater  than  thai  of  tbe 
expired  air.  it  Is  difficult  to  ^ny  how  much  greater),  and  of  the  carbonic 
nod  jircftiiiro  ••(  the  blond  at  the  .tame  time,  ao  an  lo  be  in  u  p<i«iiiou  to  euoi- 
iiatf  the  'iiie  with  the  other.  In  the  ciu«  of  oxygeu  thtrv  u  alwaya  preaeut  i 
III  the  Uiii)^ii  a  iiiirjiUiH  of  the  ffii*.  n  imrtion  oiilv  beinji  altwrbed  ai  each  | 
brcaili :  in  the  niife  of  carbonic  ucid  iIk*  whole  t|iiautily  comei  direct  from  J 
the  bliHid,  and  any  mad  ill  cations  in  brcnthiiig  ^crinui'ly  allcci  the  amouBU^ 
given  out.  Tbtif,  when  the  hri:«th  i»  held  f-ir  tuime  lime  the  porociita^  oT^ 
carbonic  ai-id  in  the  einired  air  roach(«  T  or  K  |ier  cent.,  but  we  Cftnnot  t«k»^ 
ibi*  H*  a  im-aiiure  of  tnc  noniuil  percentage  of  carbonic  Bcid  in  th«  |njl-  j 
monarv  alveoli,  *ince  by  the  men;  holding  of  the  brentli  ihc  carlxtnio  acid.  \ 
in  iW  ^ilood.  and  kciicv  in  llic  tiiilmonar;  alveoli,  is  inrrca«ci)  Iwyond  th< 
normal. 

The  difficulties  of  ihc  problem  seem,  however,  to  have  been  overcome 
an  ingeniou«  cx{>crimcnt  in  which  there  is  iutrodnccd  Into  the  broncbu 
Ihe  lun^  of  a  do^;  n  calheler,  round  irhich  is  arrantced  a  email  bag ;  by  the 
inflation  of  ihia  baj;  the  bronchus,  whenever  dt»ired,  oaii  be  completely 
blocked  up.   TliUH,  without  any  luarkcd  dbturbauice  of  tlie^neral  breathing, 
and  thcTcfuTe  without  any  uiark«(l  change  in  the  normal  profmnions  of  |]>« 
gaM-K  of  the  bhiod.  the  exMiiinebtcr  is  able  to  ulnp  the  inf;r«M  i>f  frmh  air 
ml»  a  limited  puriiiin  of  tlic  lung.    At  the  >ame  time  ho  ii  enabled  by  nirant 
of  the  catheter  to  withdraw  a  inniple  of  thi;  air  of  the  Mmc  llmitwl  jiortton 
and  by  iiiialyKiii  Ui  dclcrmim*  the  nmouiit  of  cnrbonic  acid  which  it  i-ontaiiM, 
or  ill  other  wi^rd*.  the  partiiil    prcwure  of  the  carbonic  aeid.     Tbe   blood 
pMiine  through  the  alveolar  capillaricx  nf  thi»  liiniied  portion  of  the  lung 
naturally  pomcisca  the  same  carliouic  acid  prcwiirv  as  the  rest  of  ibe  vcnoui 
blood  riowing  through  the  pnlmonar)-  arierv— n  prcnure  which,  though 
rarying  slightly  from  moment  to  moment,  will  maintain  n  normal  avenisv. 
On  the  supp'iKJiion  that  cArbonic  acid  pnsMS  t»imply  by  dilTusion  frooi  the 
pulmonary  blood  into  the  air  of  the  alvivvli,  because  the  carbonic  acid 
prcMtire  of  the  latter  Is  nonnally  lower  than  that  of  the  former,  one  would 
exjiect  to  find  tluit  the  nir  in  the  occluded  portion 'of  tlw  luni;  would  oon- 
linue  to  take  up  carbonic  acid  uuiil  an  er|uilibritim  was  establl-ned  between 
it  anil  Ibe  cnroonic  acid  pressure  of  the  venoua  blood.    Conseiiuently.  if 
after  an  occlusion,  say  of  some  miuuii-ii  iby  which  time  the  djuilibrium 
might  fairly  be  axiumcd  to  have  been  i-atabliahed),  the  carbonic  add  presaute 
of  the  air  of  the  tKx-luded  portion  were  deterniine<l,  il  on^hl  to  be  found  to 
be  eiiual  to.  and  not  nioro  than  eijutU  to,  the  carlmnic  acid  prenure  of  tbo 
venous  bl(HHl  of  Ihe  pulmonary  artery.     And  this  is  the  result  which  bm 
been  arrived  at .-  it  liog  been  found  ifjul  the  prrwun,-!!  of  tbe  carbonic  acid 
of  the  occluded  air  and  of  the  veuoui  blixHl  of  the  right  side  of  the  heart 
arc  junt  about  eijunl.     Ilenco  tbe  evidence,  bo  far  m  It  got*,  it  dinlim-tly  in 
ftvor  of  the  view  that  the  ettcape  of  carltouic  acid  tVom  the  bli>o«l  into 


TUK    RESl-IRATOKY    CI]A!IGE«   IK    TH£   TUSt'KS. 


■171 


pulnioDsrr  alvool!  ui  (imply  dut*  l(i  •liflUsIoti,  ami  tliut  llivrc  b  do  aCfid  to 
itvk  fur  atiy  riirtlii,-r  fxtilniiiiliiin.  Tlit-re  b,  ii»  far  ua  we  cnn  *ec  ftt  preaent 
at  tM  rnnn.  on  iifcvmity,  iiny  more  ihrni  in  the  com  of  oxyjutn,  U»  MippnM 
■tuU  lb*  wall  of  lh«  piiimonitry  iilvci>li  liii>  »ny  niecilic  micntory  power  of 
itiarUrLJnt;  catboiiir  a('i<l  Iniiii  llir  blimil  indvpmnently  of,  nr  iii  iinlii^oDl'ini 
to.  iIm  tnflgrno'  of  prcf»ur<i'.  or  ihat  il  rxcrts  any  uprcial  influent  M  iill  ait 
■  €]iinn>oD  H-ptiini. 

*n>n  arv  midl-  faL-te  tihicli  trtm  to  stiggnt  that  the  exit  of  carbonic  acid 
'V^cam  tba  blood  n  usiMed  by  (hi-  simiildini-ouB  entrance  of  oxvgin.  biit  Uii* 
W  nrt  il<-6niieK'  proved.  If  Midi  nn  iii')  is  given,  it  is  profmbly  brought 
^IxKit  lij  the  c-liaoce  in  the  hainioglnlnn  in  )«)Rio  indirect  nay  rniciiig  tbs 
S*V'uKiiv  of  tbe  caroooic  neid  in  the  bluad. 

Jb  far  iheu  aa  can  be  seen  at  preiwtit,  both  the  enlranoc  of  oxygen  and 
*~*^eeiil  of  earlxinic  acid  by  which  venous  blood  is  converUd  into  artcriul 
-*T  llir  simple   physical    results  of  ihe  expoeure  of  the  blood  in  ihe  pol- 
■ry  capillary  to  tbe  air  of  the  pulmonary  alveoli. 


P 


Tar.    KEdPIRATORY   ChaKOBB   IK  TBR   Tli«DE8. 

eSSS.  In  pnwing  through  (be  several  tiwues  the  arterial  blood  bvcomea 

WKT  DK>r»  venon*.   Tbe  uxyha-nioKb'bin  lieromes  coniiderably  reduced,  a»d 

■  qiMatiir  of  wrboiiie  iiciil   iwwm  from  tbe  Umihs  Into  the  blo»d.    The 

■aiennt  nr  chanice  variea  in  the  various-  tii^uei,  and  in  tbe  WLHie  timue  may 

TW^  at  dilPeretit  litnoii.   Thua,  in  a  gland  at  rvst,  ii»  we  have  sceii,  tho  v«ioits 

blood  is  dark,  (hewing  that  ihe  lia-inoglohin  is  to  a  large  extent  in  the 

ndoetd  ooadili^i ;  when  the  glnml  is  active,  the  venoiia  bluod  in  its  color, 

■sd  in  tbe  extent  to  which  the  hienrnglobin  is  in  the  coodition  of  oxy-bicmo- 

■lobia.  fwcmblee  closely  arterial  bloud.     The  blood  therefore  which  iiBaca 

Bnoi  a  gland  at  rest  is  more  "  veiions"  thiin  that  from  au  aetive  gUutd ; 

ikoagb  owinj;  to  the  more  rapid  flow  of  blood  which,  as  we  saw  in  ou  earlier 

action,  aeeompaniofl  tbe  activity  of  tbe  );land,  tlie  total  i{uantily  of  oxygen 

taken  up  from  and  of  carbonic  acid  di^charf^ed  into  the  blood  fmoi  the  glhud 

in  m  given  time  roav  be  h-realor  limn  the  latter     The  blmnl.  on  the  other 

luuid.  whii-b  cimea  Aom  on  active,  i. «.,  a  controetiiig  muscle,  is,  iu  »pitc  of 

Ibe  rooTv  r«[4d  flow,  not  only  richer  in  carbonic  ncid.  but  also,  ifaoDgh  noi 

U>  m  corrofmnding  amount,  poorer  in  oxygen  ilian  the  blood  which  flowa 

fnini  a  miiacle  at  rest. 

In  alt  these  raira  the  great  nuetition  which  conien  np  for  mir  conKtdc ration 
ia  ihi*  :  Doci  tHo  oxygen  (mm  troiu  tlie  UIoim]  into  thn  liMnuii,  anil  d(K«  tlic 
uxi'lalion  take  jiliicr  iii  ibe  tiwucs,  giving  rlM  la  carbonic  acid,  which  passta 
in  turn  away  from  ihr  I'txatt*  Into  the  blood  T  or  do  certain  oxidiiable  reduc- 
ing ■utMlancen  piiik>  fmm  llif  li»iie<  into  the  bliifHl,and  there  become  oxidized 
iniii  rartHiiiic  neiil  and  other  pnHluct«,u>  that  the  chief  oxidation  takes  pluce 
in  iIm-  bluiHi  iwellT 

Tbcre  arn,  it  i*  inie,  nnlnnng  oxidixable  tiibstsnce*  in  tbe  blood,  but  Iheae 
■n  sanUI  in  aroiHint,  and  the  •pianlily  of  carbonic  acid  to  which  iboy  g;ive 
rin  when  the  bkind  conmining  them  is  agitated  witb  air  or  oxygeu,  b  w 
MBoll  as  scarcely  to  execeil  (he  errors  of  obaervatiun. 

On  tlie  ntlter  hand,  it  will  be  remenibeml  that  in  Bpeakiog  of  nmacte.  we 
drew  ailcntioo  (§  I>1 1  to  the  fact  that  a  fn)g's  □iiiscle  reinorea  ttom  the  ixidy 
(and  the  same  is  triieof  the  muscles  of  other  animal-i)  contains  no  frve 
oxygen  whatever;  none  can  be  obtained  from  it  by  tbe  mercurial  air-pump. 
Yet  MiHi  a  muM'te  will  not  only  when  ut  rest  go  on  producing  and  ditcfaarging 
a  cennin  >juaniity,  but  also  when  it  contradt  evolve  n.  very  oondderublo 


472 


RESPIItATION. 


quantJ^,  or  citrlMiiic  uciil.     Al<>n^)vcr,  ilii»  ilitdiiirge 

go  OD  for  II  I'erluin  tiini'  in  muH'lci'  iiikUt  rirniniftanon  in  urlucli  il  is  iin- 
poKfiblc  for  ihfin  lo  ohisin  oxyKrii  from  wilboat.  Oxrgcii,  it  is  ini«,  ia 
nccwuMiry  for  iho  life  of  llw  mii^Rfc  ;  when  venous  iiieU-Aii  of  artwiid  bKiwl 
n  Milt  tbrmigh  ilio  blooilvceM;!*  of  a,  itiufcIp,  the  irriuibility  upcctlily  <li«- 
npiicnra,  and  unlcn  fresh  itxygi-n  bo  admin  isicrt'd  the  muscle  aoou  ilia.  T1h> 
muscle  nmv.  however,  liiiring  the  inicrvtil  in  which  irrititbility  i*  still  r> 
tnineJ  after  the  supply  of  oxygen  has  been  cut  olT,  eontinuc  ta  contract 
TigoroU!<lr.  The  supply  of  oxymo,  tliough  neecssary  for  the  iiuii»i'-niiN«  | 
of  irrilaliiHty,  is  Dot  ncceemry  for  the  man^e^ation  of  llial  irriubility,  is 
Dot  Dotweary  for  ihnt  «sploBive  'lecomjKMition  wliieh  develonH  n  contrnc- 
tion.  A  frog's  tnuade  will  continue  to  coiitraet  and  to  prouuce  carbonic 
acid  ill  an  atinoepfaere  of  Iiydriigeii  or  oitro^eD,  that  is.  in  tb«  total  abaenvc 
of  fhse  oxygen,  both  from  iu«lf  and  frum  th«  medium  in  which  it  b 
placed. 

Thus,  on  tlie  one  hand,  the  muscle  seems  to  have  the  property  of  takinirj 
u|>  and  fixing  in  some  way  or  other  the  oxygen  to  which  it  in  exposed,  <rfn 
BtioriuK  it  u^  in  iu  own  substance  in  suc-h  a  CDuditiuu  thai  it  cannot  be  re- 
moved by  simple  dimiuiflhcd  prewure  (so  that  the  pre^ure  of  oxyKcn  iu  ih^k- 
miMcular  subttance  may  Ik-  cuuiii'Iered  as  always  nii),  and  yet  )uu  nou 
entered  into  any  diatinet  conibiunlion  which  wu  can  speak  of  ta  an  oxida- 
tion, but  ia  still  available  for  such  a  purpose.    The  idea  has  beeii  put  fur— 
~  ird  that  the  oxygen  iu  Uiis  comlilinu  js  physiealiy  atladied  lo  and  1' 


between  llie  muleouTes  »f  the  muscular  siitHiiunoe  without  tieing  clirmicsillr 
ownbined  with  tlieni,  and  henee  haii  bt-cn  siiolcen  of  lut  "inlra-molecular  * 
oxygen  :  but  we  linvc  no  exnet  knowli;idgc  lu  to  what  its  oondili'in  rcnllv  la 
at  this  uliigc.  On  the  other  hand,  the  muMrnlar  xiibslanoc  is  alwitvH  under- 
going n  decomjitmilion  of  such  a  kind  that  cjirbunic  acid  is  sut  free,  some- 
timo,  ns  when  llie  mnsele  ii  nl  rest,  in  small,  oometimee,  as  during  a  con- 
tractioo,  in  Inrge  (piantitics.  The  oxygen  preeeut  in  ihis  earhnnie  acid,  ai 
an  oxiiiatioD  product,  enmee  from  the  previously  existing  <^ti>re  of  wbicb  w« 
have  just  spukeu.  The  oxygen  taken  in  by  the  muscle,  whatever  be  ib 
exact  condition  immediately  upon  \V  entrance  into  the  muscular  subataooc, 
in  the  phase  which  lias  Ik-i'h  cAJled  "intra- molecular,"  sooner  or  later  enten 
into  a  cum bi nation.  i>r  perimps  we  should  rather  say,  enters  into  a  »«ri»  of 
combinatiouH.  We  have  previously  urged  (§  :tO)  tiiat  all  living  aubatau<« 
uiav  be  rc^ardfid  a>  iDoewaiitly  uudergoiug  changes  of  a  dmible  kind,  changa 
of  building  up  and  cluuigee  of  breaking  down.  In  the  en'I-pruduct«  of  liitt 
breaking  down,  in  the  carbouio  acid  given  out  by  mnsele,  for  insumce,  we 
can  recognin;  an  oxidation  product ;  but  we  do  not  knuw  exactly  nt  what 
•cage  or  exactiv  in  wliat  way  the  oxygen  is  ouiuhined  with  the  oarbon.  We 
may  imagine  ibat  the  oxygen,  as  it  coinai  from  tlie  bloid,  i*  caught  up  so  lo 
atHUk  by,  and  disap{»cnnt  in,  the  building  up  proceMes  (forming.  poMibly  at 
toe  very  Ix^nning,  witli  noiuc  convlitucnl  of  the  mutteulnr  siibstAuoe  a 
combination  like  to  but  firmer  imd  niiire  Ktablc  than  its  combination  with 
haiDloglobin^,  and  that  through  ihosi.t  procenM^  it  is  made  part  of  irouplex 
dteonjKiubie  subslanco  nhwe  di'^;ompo»ition  ultimately  gircs  riw  to  the 
carbonic  nd<I :  but,  as  far  as  aetutil  knowledge  goea.  we  caonol  as  vet  trace 
out  the  steps  taken  by  the  oxygen  from  the  nioment  it  slips  ftom  llie  blood 
into  the  muscular  suhst-tnee  to  the  moment  when  it  issues  united  with  earboa 
as  carbonic  acid.     The  whole  mystery  oi'  lite  li'«  hidden  ill  the  story  of  that 

Iirogrci^,  and  for  the  present  ve  must  be  content  with  simply  knowing  the 
iCKiimtng  and  the  end. 

Itut  if  the  oxygen -pressure  of  the  muscular  Useue  be  thus  alwaya  nit, 
oxygen  will  be  alwaya  paHiiig  over  from  the  blood  corpusoles,  in  which  it  it 


i 


1 


TlIK    R88P1RATORY   CDAKOES   IX   THE   TlSSl'BS.       478 

« I  cnopvstiv«ljr  high  prcmre,  ibraugh  llie  nliumn,  through  the  <-npi1lar,r 

valh,  lbs  lynph'>|MC«t,  aixl  the  sHrcalcniDa,  into  the  luufciiliir  nutwtauco, 

lalaitoap  W  il  nrrivcH  lbi>r«  will  hv  iti  ngim-  mgiiiiirr  or  other  bid<I«n  nvray, 

laiiag  iho  oxyifrn-pmgiiin;  uf  llii^  mutiulnr  niitwiiirivc  onoc  more  nU.     Coti- 

Kifiljr,  the  c»rliiiiiii'  mciil  produced  \>y  ihr  liivwmpojiilioii  of  llio  miin-iiliir 

•Muee  will  u-inl  Ii>  riii»e  llw  eHrlxmic  nci<l  im^iiri'  of  the  mmclr  until  it 

mmit  that  of  (Ih-  hloml;  whereupon  carbuiiic  ucii)  will  ]ia»  frtini  tlw 

ill  Into  the  bluot],  iu  i^nev  in  iIh-  miiBcuiiir  eub»tjince  being  siipplieil  l>r 

i]f  gtncntcd  luppliea.     There  will  ttliin)^!  in  fnri  bo  a  nlrcfttn  ofoxygm 

I  llw  blooH  to  the  diumIo  uid  of  carbuiiic  ncid  from  the  muscle  to  lh« 

UonL    The  r<«|iimlM)0  of  the  muscle  then  doca  not  consiM  in  tlirowini'  into 

iW  Uoo<)  oxiiiixable  eubetincee,  there  to  be  oxidized  into  cnrbonic  nciJ  and 

^ilT  nuiu-n;  but  it  does  consisl  in  thonHumption  and  sloriiif;  iipaf  uxTgMi 

^OMhim  or  other  in  its  anbetatice.  in  the  btiildini;  up  by  help  of  thai  '>xTge» 

^*xploMve  deoomCMMRbie  substances,  and  in  llie  cnrrvin^;  out  nt'  deeompjei- 

**'*oaa  whereby  enrbontc  acid  and  other  matters  itre  cliscliarKed  Hrat  iuto  the   M 

"'"'iMlce  of  tite  miiKle  and  subaettuentiy  iuto  the  b!ii>>d.  f 

^^  360.  Our  knowlei))-e  of  the  n-xpitaiory  e)iau)>ea  iu  muscle  is  more  com* 

*!**'<•  than  in  the  oase  ofany  other  tissue  ;  but  we  have  no  reason  to  suppoeo 

''**    the  pbeoomeDK  of  niuwle  are  exc-eplioual.     On  (lie  coolrarv.  all  the 

■  ^'nilable  evidenee  gctea  l<i  »h>iu  ihut  iu  all  linun  the  oxidation  talcee  pUee 

l''  the  tissue,  and  n»i  in  the  n<ljoiuiii;c  blood.     It  is  a  remarkable  fact  Ibat 

^■»l>h.  serous  Huitb.  bile,  urine,  ami  milk  cootaiu  a  mere  truce  of  free  or 

*****ly  eonibineii  oxyiteD,  but  a  very  cousiilurable  ijuantity  of  carbonic  acid. 

,  ^Url  vre  may  prvbably  asMit  with  Mifety  nilli  rejmrd  to  all  the  liaaues  that 

."  ibc  tiviKi  ihemaelvea,  in  the  Ivniph  which  bauies  their  lymph^pacee,  and  ■ 

*»  iho  **ofcUoni  whicli  Mime  of  lliem  |M>ur  forth  free  oxygL-n  in  eitlwr  wbollv   ^ 

*bicnt  or  M  tnuity  that  their  oxygen -prcMu re  nwy  be  ngnnlti)  m  mU,  whife 

^Krbonio  aidd  is  to  abundant  that  the  prenura  of  carbonic  acid  in  them  may    ■ 

(■■  rvgsnlad  as  exorciling  that  of  venous  blood.    An  excciilion  seems  to  b«  fl 

piiimiiliil  by  the  case  of  the  lymph  floving  alon^j  the  lar^r  lymphatic 

Vviaala.  for  in  Ibi*  the  amnuni  of  carbonic  acid,  while  usually  bicher  than 

Uutt  of  arterial  blwd,  if  lower  than  that  of  the  general  venous  blood ;  but 

tbia   tirobably  la  doe  to  tlic  fact  iliat  ihe  lympn  in  ita  pannce  onirard  is 

lAfl^erly  CI  |viec<]  to  arterial  blood  in  the  conneciivetisimci  and  in  the  lymphatic 

^laui'i^,  where  llie  production  of  carbonic  acid  is  slight  as  compared  to  that 

KoioK  on  in  muscles.     All  llie  facts  poini  to  the  conclusion  that  It  is  the 

CliatMa.  awl  not  the  blood,  which  become  primarily  loaded  wilh  carlmnic 

■»H<1,  the  latter  simplv  receivinj;  the  saa  IVon  the  former  by  diffiision,  except 

^^^hp    ([imbnbly)  small  ouantity  which  results  from  tlie  metabolism  of  the 

^^^Kod  ooqtusolei;  and  that  the  oxy;-en  which  paassa  from  the  blood  into  the 

^^Hbmm  i*  at  aaee  taken  up  and  placed  under  such  conditions  that  it  is  no 

^^l0M>f  remorable  by  diminished  preniiie.  ■ 

^^        Id  Atrther  Mipporl  of  thL<  view  may  be  urged  the  fact  that  if,  in  a  tng.    ' 

the  whote  blood  of  the  IhhIv  tx-  replai.-«d  by  normal  saline  sohilion.  the  total 

metabuliaiD  of  the  body  i.i  lor  >omt-  lime  unchau^^.    The  saline  metlium  is 

able,  owing  to  tlic  low  rale  of  wrtaholi»m  and  large  (cutaneous)  renpiraior^- 

wrfioe  of  the  nuimiil,  to  Mijiply  the  linmet  with  all  the  oxygen  tliev  need. 

and  lo  remove  all  thr  carbonir  acid  tliey  pn>iluc«.     It  i*  difficult  to  believe 

that,  in  such  an  exixrimi-nt,  the  oxidation  took  place  in  the  saline  solution 

ittcif  while  circulating  in  th<'  bliMHlm-vIs  and  tiM(ue>«paoea  of  tlie  animal 

We  mav  add  that  ihc  oxidative  ponvr  which  the  btoml  itself  removed 
bom  the  &ody  is  able  to  exert  »u  ■u)>c<tnnco'  whii'h  arc  uiidoublciUy  oxidixed 
h  Ihe  body  la  M  small  tliat  il  may  be  neglcclcl  in  the  pnvt-nl  omiidera- 
I  llgwai     If  grapxcgiu'  lie  addol  lo  blood  or  lo  a  solution  of  haemogloblu,  the    ^ 


1 


474 


KBSl'IKATION. 


tnixtitre  taty  bo  k«Di  for  s  \oajt  time  ni  the  umperaiure  of  tli«  body  with- 
oui  uiMktgoing  axtclnlioD.  F.v«d  within  i)i«  body  a  xli^ht  excea*  nf  sujiar 
in  Uie  Uowl  over  a  eeriiiiii  (wrcvnta^  wholly  vnc«|)m  i>xi{tnltiiD.  nud  is  d»- 
ohorged  un«h«ngwi.  Miinr  ciutty  oxiiliiutl  xilwrtunccs  «uch  w  pyrDjpdlw 
Mid,  )MM  InraoJy  througb  the  blood  i>r  n  living  biMly  nnd  mn  dbcMrgM.in 
the  iiriiii^  witliotit  being  oxKliwd  ;  thniiEli  |>rri)niHi  in  ■nnir  of  Umm  CMH^ 
wluU  ii[>iicnr8  lo  he  iin  nbMOM  of  oxidaUion  is  rr-olly  nn  niidiilHUi  fbUowwl 
by  m  mibwijueDt  ixjuivulcnl  mluctioD  Uiking  |>i«oi-  in  thi?  urin«  or  elMwbsre. 
Inc  oreanic  Mciil«,  such  ttt  ritric.  ev«n  in  comhinntiiti)  witb  HlkaHtut  bakw. 
■n  odIV  fxinially  oxidixed;  when  lulininHWnNl  m  Mcids,  ud  tuA  of  mlts, 
Ui«y  iirt-  h«r<lly  oxidixod  U  hII.  It  w,  of  course,  quite  poasiblo  thnt  the 
chnn^ra  wliirh  tb^  blood  undergom  when  shed  might  interfere  with  its 
oxidative  si-tion.  and  bonce  the  fact  that  shed  blood  has  liltle  or  no  oxidizing 
pow«r,  is  not  a  satisfactorr  proof  that  th«  unchanf^  blood  within  [ho  living 
TCOeJs  may  not  hnre  eiicb  a  power.  Itut  did  oiidatiuD  lake  place  largely 
in  the  blood  itaelf,  one  would  ex|)e<ct  even  highly  diflbsible  siilwtanccs  to  tit 
oxidized  in  tbear  trauHt;  whereas  if  we  suppose  the  oxidat>i>n  to  tak«  pbuM 
iu  ih«  tissues,  it  keeonies  int«tligible  why  such  divisible  siibsiano»  as  tboae 
which  the  tiwuw  in  gei>eral  refuse  to  take  up  largely  should  readily  \»ea 
unchaii)^  from  ihe  blood  ihruuf;b  the  exeretinK  orpuia. 

We  have  seen  that  in  niustile  tl>e  ]>roduc(i<in  if?carlMnic  acid  ia  nol  directly 
deiiendent  on  the  co4isuuiptiuu  of  oxygen.  The  uiii«-le  [jnMluces  carbuntc 
acid  in  as  atmosphere  of  bydrugvn.  What  is  true  of  muHcle  is  tnie  aUo  of 
otlter  ti»u«s  and  of  the  body  at  huge.  It  wan  »hown  lung  ago  that  aoiniata 
might  coniiuuc  to  hnMthe  out  carbonic  acid  in  an  atmosphere  of  nilrogCD 
ur  bydriijccn ;  and  thin  liiui  more  recently  been  illuNlmlM)  by  thi-  n'mHrkal)l« 
exjicrinK-Ml  thai  ii  fr<i^  kept  at  a  low  lemjirratiiro  will  live  for  wcvcral  hourn, 
and  i'unlihu«  li>  produce  carlKuiic  iK'id,  in  an  iitmii*pbor«  alBiilulely  I'rm 
from  oxyg«R.  Tim  nirlx>nic  lu'itl  pro<liii-i-«l  ilnring  ihtit  ixritxl  was  made  hy 
bi'lp  of  tbo  oxygen  io«pircil  in  tiK-  Wiir*  anterior  to  the  cmmmciMomenl  of 
the  pxin-rtmeiil.  T\i«  oxygen  then  iilwirKni  was  Ntowed  away  frtMU  tb« 
liii'iuuglohin  into  Uk-  tiwuics,  it  was  made  umsof  to  build  up  the  explosive 
oomjMiundii,  wltow  cxphwions  later  on  gare  riw  to  the  carbonic  arid.  Or,  to 
adopt  a  simila  which  ha:>  be«n  euggmted,  the  oxygen  helps  to  wind  up  the 
rilnt  cluck ;  but  once  wound  up  the  clock  will  go  on  for  a  period  without 
t^irther  winding.  The  frog  will  continue  to  live,  to  move,  to  produce  car- 
txmifr  acid  for  a  while  without  any  fresh  oxygen,  as  we  know  of  old  it  will 
witlMMit  nny  (rvfih  f<iod;  it  will  continue  to  do  i>o  till  the  explosive  oom- 
pounds  which  lliv  oxygen  built  upari-  exhausted  ;  it  will  goon  until  the  vital 
clock  hii*  run  donn. 

!i  361.  To  Mini  up,  then,  the  results  of  reapiration  in  its  elieaitca)  aspects. 
As  the  blood  passes  through  the  lungs,  the  low  oxygen-pni^sure  of  the  venoua 
blood  permits  Ibeeotraiiceof  oxygen  finm  the  air  of  the  oulmonarv  alveolus, 
through  the  thin  alveolar  walls,  through  th^  ihiu  i-npillary  sheath,  tlirough 
the  ibin  layer  of  blood-plasma  Co  iho  red  cor]>UM-le,  and  tlw  rei)uci-d  hietno* 
globin  of  the  venoua  liloud  becomes  wholly,  or  all  hui  wholly,  oxy-hsDino- 
^l<d>in.  Hurried  to  the  iLnsuee,  tlie  oxygen,  at  comparaliiv/y  high  prvwurt 
to  the  arterial  hiMHl,  pustm  lurgely  into  tbi^m.  In  the  tHsucii  the  oxyg«ti- 
preanure  u  always  kept  at  an  cxce«<linglv  low  pitch  by  ilic  fact  that  thvy,  tu 
aome  way  at  prateni  unknown  tu  uh,  |i«c1c  away  at  every  monK-nl  into  some 
Mible  combination  each  moh>i'ule  of  oxygen  which  they  receive  (rum  the 
blood.     With  its  oxvhienirwlobin  largely  out  not  wholly  rvducrd,  the  blood 

SiMtm  on  tw  vcnotit  blond.     To  what  extent  the  hicmoglohin  is  ntluccd  will 
lepeiid  on  the  activity  of  tl>e  twsue  i(*clf.    The  ij^iiantity  of  hicmoglobin  in 
tba  blood  ia  the  in«asun)  of  limit  of  the  uxidixing  power  of  the  body  at 


T«K    SKRVOCil    MKCHASISU    Of    KEdP[  RATIO^f . 


475 


larfTO ;  1>iil  within  tbal  Umic  the  amotiDt  of  oxidation  is  ddcnitinod  tty  the 
ttMU«,  aim]  bf  th«  liaeue  ulooe. 

Wo  vAiinot  irtoe  the  oxyBcn  thraucU  iia  sojourn  io  the  tisMio.  Wo  only 
know  ihM  sooner  or  Ut«r  il  comee  nack  oomhined  in  carbonic  x^id  v«>id 
other  matten  not  now  under  consideration).  Owinn  to  iho  continmil  prii- 
duction  of  curbonic  acid,  ihf  pn-vsure  of  that  jim  in  the  extrii-Tiwoular 
eleincnU  of  the  liaeue  it  nlwaya  hi;;ht^r  than  that  in  the  blood:  the  |^ 
■coordini^lir  patse*  from  ilie  tiwne  inl«  thti  hUmd.  and  the  vctiou*  hli^id 
piuwa  OD  not  only  nilh  it«  hictuuiilobin  num  or  tnw  reduce*],  ('.  e.,  with  it« 
oxy(,'eu-pr«eauredecraa«<t,  but  ai.iii  witli  itH  carbonic  acid  prenure  increiisccl. 
Arrired  at  the  lungs,  th«  hloixl  liiidtt  ihi:  pulmonary  air  at  a  lower  carbonic 
Mid  prenure  than  iUelf.  Tlic  gM  acwrdiiiKily  ittream*  throuEh  the  thin 
va«cul8r  aiid  aiveoUr  wallii  until  ihn  pruMure  wiihmit  the  hloodveseel  is 
equal  to  tlie  )>r«aMnre  wilhiti.  At  the  wme  lime  the  biixid  liiidi  in  the  air  of 
the  jiulmonarj  Blv(n>li  a  ttupply  of  cixvgc^n,  more  ihaii  adc(iuali>  to  convert. 
i>ot  entirvlr  but  nitarly  wi,  the  rediiiTil  Wmuglohin  hnck  again  to  oxy-hieino- 
ghibin.  IhuH  the  air  of  ihti  piilniotiary  atvc«li.  havinz  given  up  oxyKen  to 
the  i>looi)  ainl  taken  up  enrlKtnio  acid  iVum  the  blood,  having  id  conwqueuue 
a  hi^licr  carbonic  wid  prewitre  and  a  lower  oxygen  prcMurc  than  the  liilal 
air  in  the  bronchia)  piuettccs,  mixes  rapidly  with  this  by  ililfu»ion.  The 
mixtiin.-  in  further  iu»i)>ted  by  ascending  and  desoaiding  currvnta;  and  the 
tidal  air  inaues  from  the  ebott  at  the  breathing  out  poorer  in  oxygen  and 
richer  in  carbonic  acid  than  the  tidal  air  which  entered  at  the  breathing  in. 


Tuc  Ni^ivovH  Mkchahisu  op  KlSPIItATIOrr. 

i  36S.  Brenihiog  is  an  iovolunlary  act.  Though  the  diaphragm  and  all 
the  otiier  inu«oIe<i  employed  in  respiratiivn  are  vofuutary  muscles,  i.  «.,  mus- 
cles which  can  l>e  called  into  action  by  a  direct  eflurt  of  the  will,  and  tJiough 
respiration  may  be  modiiled  within  very  wiile  limits  by  the  will,  yei  wo 
habitually  broithe  without  the  inierventiun  »f  the  will ;  ttie  normal  breath- 
ing may  ooiiiinue,  not  only  in  the  aWnoe  of  oiHuciiuimmt.  but  even  at\er 
the  removal  of  all  lite  psru  of  the  brain  above  th«  medulla  'ihlongaUL 

We  have  nlieady  seeii  bow  oompliealcd  is  even  a  ximple  renpiralory  aoL 
A  very  Urge  number  of  muHcIes  are  called  into  pluy.  Many  of  tlutMi  are 
very  far  aimrt  Ihitii  Mch  other,  such  as  the  diaphragni  ami  the  iia.'otl  oiuHcIea ; 
y*t  they  act  in  hartDonious  sequence  in  point  of  time.  If  Uie  lower  iiiter- 
coMal  muscles  contniet«d  bcforu  the  scaleni,  or  if  the  dia|>liragiii  contracted 
alternately  with  the  other  <■batt-mu.■^:]eK,  tli<:  ntiffiictory  entrance  and  exit  of 
air  A'ould  let  imptMiiblc.  T)i««i  muscle,  moreover,  are  CMirdiniiled  iiIho  in 
iwpeet  of  tbo  amount  of  tlu-tr  Mronl  contractions ;  a  gentle  and  'irdinary 
ooBlractiun  of  the  diaphragm  is  accompanied  by  gentJe  and  onlinarr  otui- 
Iractiotia  of  the  intercostals,  and  them  are  preceded  by  gentle  and  ordinary 
Cnnlnictions  »f  thi-  scalcui.  A  forcible  contraction  of  the  scaleni,  followed 
by  simply  a  gentle  contraction  of  the  iutercoetals,  would  jwrhape  hindor 
rather  than  awist  inspiration,  and  at  all  events  would  be  waste  of  jNiwer. 
Further,  the  wlwlc  complex  inspiratory  ellbrt  is  often  followed  by  a  Ins 
marked  hut  still  complex  expiratory  action.  It  is  impowible  thai  all  tlieea 
so  carefully  coordinated  muscular  cmniractiona  should  be  brought  about  in  any 
Other  way.  than  by  coordinate  nervous  impuUcs  deiicending  along  elfervut 
narvca  from  a  coordinating  nervous  centre.  I)y  experiment  we  find  ibis  to 
Ijc  tlie  case. 

When  in  a  rabbit  the  trunk  of  a  phrenic  tierre  ia  cut.  the  diaphragm  oa 
(hat  side  remains  motionlea<,  and  respiraliun  goes  on  without  it.    When  both 


m 


RBSPIRATIOS. 


cut,  tlie  whole  diaphr 


quiewuni,  though  th«  coctal 


nervre 

rcApinitioii  becomes  «xcemivcly  Itkbored. 

Wlicn  Ml  iDier(xi<lal  nerve  is  out,  do  active  rwpirnlory  nioviMiM>Dt«  an 
«Mn  in  the  iutercoetnl  muscles  of  the  correBpoixliiiK  epnoo.  nnd  when  the 
spinal  cord  is  dirided  below  the  ori^'in  of  the  seveath  i-ervical  spinnl  nerve, 
lltat  is.  below  the  exits  of  the  roots  of  the  plireoio  uerves.  coetnl  respinttion 
ceases,  thou>:h  the  diaphrasm  eootinueB  to  a«t,  and  thai  witli  inc-reased  vij^or. 
When  lite  cord  is  divided  juet  below  the  inedulla.  all  thoracic  movemeDtB 
cease,  but  the  respiratory  actions  of  the  ncwlriU  hikI  );loiiis  Mill  couttooe. 
These,  however,  disappear  wheo  the  fadal  aiid  recurreut  laryii^ceal  uerres 
are  divided.  We  have  already  slated  lliat  afU-r  rviuoval  of  tbe  Itraiu  nhox'* 
the  m^ulla,  respiration  still  cootinuea  vtry  much  as  usual,  the  iU'>iiifii-A liana 
which  4'j)9iie  I'roni  the  km  of  the  brain  being  tin  essential.  Ileiice.  |tiiiiing 
all  these  facts  together,  it  is  clear  that  thu  nnpiraturr  iiinvcnitrDts  nrt',  iu>  w* 
suggested,  brought  alwui  by  oocirdinated  impnlsnt  which,  devdopitl  iu  tha 
oenual  nervous  systein  and  ittarliu)i  in  tbi-  Rnl  inHlanuu  in  tlu!  nmlullii,  find 
their  way  along  the  several  efllsruot  nerve*.  The  proof  is  coinpletMl  by  ttio 
fact  that  the  reniovnl  of,  or  exUmiiivi'  injury  t^i,  iIm^  nicdiillu  aloiio  is,  Mvi-  in 
excejtiioiinl  cast*  which  we  will  discuw  presently,  at  oiic«  followed  by  the 
CMHlion  of  all  reepimtof)'  moveoHuit*,  even  though  the  rest  of  liie  iiorvou» 
nrstem  including  «very  muscle  nnd  ercr^'  nerve  cuncemed  be  Utt  intact. 
Nay  more,  if  only  a  smalt  portion  of  the  medulla,  a  tract  wlii»e  limitu  have 
not  been  clearly  defined,  but  which  may  be  described  as  Iviug  below  the 
vasomotor  centre  in  the  imtncdiate  Deij^iKiriiood  of  the  nuclei  of  the  vagtis 
nerves,  be  removed  or  injured,  rcdpiralioii  tvAHcs,  nnd  di-iith  »t  once  ensoee, 
Honoe  thia  portion  of  the  nervous  system  km  called  by  Fluurens  the  vital 
knot,  or  )^t;Iion  of  life,  na-iid  vital.  We  ehalt  »jieah  of  it  as  the  rc4p*mtory 
Wttlre, 

<}  363.  The  uaiure  of  this  centra  roust  he  e-^ceedini^ly  complex  ;  for  while 
even  in  ordinary  tespiraiion  it  given  rise  lo  a  whole  group  of  cioordinale  ner- 
reus  impulses  of  inspinitiou  foiloncd  iu  duese<|ueace  by  a  smaller  but  »till 
coSrdinale  ^roup  of  expiratory  imnulses  of  an  antagonistic  nature,  iu  Labored 
re^iratiun  fresh  aud  laiyer  iinpiilsea  are  generated,  tliougli  still  in  eoordina- 
tion  with  the  normal  ones,  the  expiratory  evenU  beinn  eapedally  aui^mented ; 
and  in  the  caaw  of  more  extreme  dyspnea  and  asphyxia  impulses  overflow, 
mi  to  Hpeuk,  from  it  in  alt  diredioiu,  thoush  only  gradually  looung  their 
coiinii nation,  until  almuttt  every  muscle  in  theltody  is  thrown  into  contratitioiu. 

We  must  not,  Itowever,  ci>iievive  ul'  thin  oentrc  a*  one  of  sui-ti  a  kind  that 
the  impulses  leave  it  fully  r(M)rdinaU^l  bimI  (vjuippul  no  ihal  n^ithiog  rcmnins 
for  tlieiu  hut  to  travel,  unchanged,  alontt  thir  m'vitiiI  cftiveiil  nerve-fibrc:'  to 
thfir  Mvcral  niuwculnr  destinations.  On  ibv  (xuiliary,  we  have  reason  to 
think  ihat  the  nttpiratnriF-  motor  nerves,  like  other  niirtor  nv-rvw,  are  con- 
ni;cU-(l  juKt  US  they  an?  about  to  tnoe  from  the  spinnl  eord,  uilh  a  nitrvous 
machinrrA'.  in  which  mtrve  eelU  play  a  pnrt — a  point  which  we  shall  consider 
mori.'  fully  in  trcuting  of  the  spinal  ctinj :  we  have  reason  Ui  think  that  the 
r^T-pinil->ry  impulsw  stttrting  from  the  respiratory'  vcntro  paw  into  and  are 
iiioililit^il  by  Mecon<larv  spinal  nervous  mi.'<chanisms  beforo  they  issue  along  the 
riiNi.rr  nerve  rootA.  imteod,  observatioiM  show  that  under  particular  oondi- 
lioDH,  and  espc-ialjy  in  young  animals,  respiratory  movemenis  may  be  carried 
out  in  the  entire  aliseiieo  of  the  medulla  oblongatA.  Thus  if  in  n  kitlen  or 
puppy,  or  young  rabbit,  after  divitiion  of  the  spiaal  cord  below  the  medulla, 
artindal  respiration  he  kept  Up,  and  then  pauses  be  made  in  the  ariilicial 
respiration,  during  these  jiauses  uol  only  may  what  appeer  to  be  respiratory 
movements  be  intniced  in  a  reflex  manner,  by  pinching  or  by  blowinj;  on  the 
skin,  but,  esjwdalty  if  tlie  excitability  of  the  spinal  cord  be  hdghtened  by 


TRX    XKRVOUS    MKCHANI&U    or    RKXI- 1  RATIo:f . 


477 


I 


I 

I 

I 


mII  iattt  ot  Mryehnine.  own  »|K>iitiin<H>iis  c(l<>rW  of  brcutliiii^  tiiat  occa> 

itmiflT  bftobMrrod.     Thnoare  tlicxcvjiiional  imtmioe^  nii-ii Honed  nbovo. 

Km  a  ncfa  nun  the  rhvlhmicnilv  rvpenlc<l  movomciite  of  llio  respinitory 

■mtIm  arv  •Oiiivtinx-e  ncconiptiniitf  by  rtiytltniic  movcmcnle  of  the  fore  soil 

inl  tiaiba  not  rMpimton-  in   natiiro,  it  mttv  be  doubled    wbetber  tbeae 

'VptrilMnts  rwlly  prove  tW  exb>tcn<«  of  dUtincC  reepirator^  centres  ia  the 

ifml  rOrd:  ind  at  moel   lh«y  merely  show  that  the  respiratory  nervous 

■Ktiabm  tt  DuC  enlirvty  contined,  as  was  oace  thoki{;hl,  to  the  c«>»tre  in  tbe 

•Hblla,  but  also  eoibracea  other  Huhiidiarv  mechanisniB,  which  may  perhnpa 

b  ipakcD  of  aa  centre*,  in  the  spinal  coni  beloir.     It  has.  iudeed.  bt«u  miiiu> 

liiaad  by  eom«  that  thme  lower  aptuul  centra  are  the  chief  ueotres  and  tliat 

licinedtiUary  c«mre  acta  merely  in  ibe  way  of  ref[ulatiu);  th«iie;  but  U  ditK- 

rait  to  leoMicile  ibta   view  with  llie  eapericaoe  thai   inli^rlert^d  with  the 

""lulla,  limited  eulirely  i<>  the  medulla,  ao  ofton  IcxU  ti>  the  entire  alxjli- 

"m  oftbe  i«e|)iratorir  move  men  m.    This  motier  is  not  al  prcacnt  thoroiifthly 

*vrkc>ii  otit,  but  we  shall  probably  not  greatly  err  iii  regarduig  the  rrnpira- 

^^fy  iwrroiua  system  as  in  many  waytt  analogoua  U>  tlie  Toaomottr  m-r^'oua 

*?M«n,  wiili  its  bead  centre  iu  the  incilulla,  and  secondary  centres  eluowlifrc, 

*)H  in  c<naiin(iin|{  Iu  «peak  of  tbe  ci'uire  in  the  nu-dulla  n»  iM-ing  "  the  nwpira- 

^rycwnirc"  nhilL-  nilmiltiiig  tluit  it  works  lbri>u^h  otbiT  nervniix  machinery 

l*Wcwi  lower  down  in  tlie  «piiud  curd,  ami  that  thin  iiuliorliuaU'  ninchinory 

*^r  in  Dxci'ptional  ranw,  carrj'  iwt,  though  iuadcc|iialely,  the  work  of  the 

*iim  omtn. 

t  964.  Adinilling  then  the  existence  of  tliis  medullarv  rmpiratory  ccatr» 
till  iititatioo  uainrally  arises,  Are  we  t«  reeard  its  rhytnmic  action  as  dua 
l^mitially  to  changw  Inking  place  in  itMlf,  or  as  due  to  alTerent  nervous 
itaiMilBn  ur  othvrtlimuli  which  nHb<a  it  in  a  rhythmic  tnaniior  from  without T 
in  otber  words.  Is  the  action  of  the  centre  automatic  or  purely  rcficx?    We 
know  tbai  ll>e  centre  may  be  inHuenced  by  impulses  proceeding  from  without, 
■ad    that  ll>e  hnAlhin;;  mav  be  ellecled  by  ilie  action  of  the  will,  or  by  aa 
amotioii,  iir  by  u  d&*h  of  cold  water  on  tbe  skin,  or  in  a  hundred  otiter  wa^; 
hilt    tbe  &ct  that  tbe  acliuD  of  the  centre  may  be  thiiH  modified  fn>m  with- 
out, is  uo  proof  that  the  continuance  of  its  aL-tivity  is  dependent  on  exirinaio 


In  atiemptinf;  to  decide  tbb  question  we  uattitvUy  turn  to  tbe  {Mieumo- 

t— *'if'  <"  °^°g  t^^  nerve  most  likely  to  serve  as  the  channel  of  aJTereut 

laapmlaes  setting  in  action  the  respiratory  centre.     If  b»tli  vaKiis  uervea  be 

diviiln).  ra[iinttiuii  >till  oontinuea,  thou^lt  ia  a  modified  furm.    Thin  provca 

(UrtiiicUy  that  alfereut  impulses  ascending  those  narve^  are  not  the  ■■tBcient 

CMHtof  tli«  renurator}-  movementa.     Wo  have  ween   that  irhea  the  spinal 

«acd  is  divided  b«low  the  medulla,  the  facial  and  laryngeal  movement*  Mill 

continue.     This  provts  thai  the  re»|iiratory  oenire  h  »till  in  action,  though 

its  activity  is  tmable  to  manifot  itielf  in  ikny  thorado  movement.    Rut  wlHin 

the  c«rd  is  thus  dividcal,  the  respiratory  centre  in  cut  otT  from  all  sensory 

impalsci,  wre  th<»«  which  may  put*  inli^  it  from  the  cranial  imfvcs  of  tua- 

tarf  AiMtioa :  and  that  these  tenixiry  cranial  nervea  are  nut  speciallv  oon- 

ccmed  in  drvdojMng  the  activity  of  the  respiratory  centre  w  shown  {»y  Ibe 

foct  that  the  division  of  tlMSC  cranial  nerves  by  thsoiMlTas,  when  thentGdiiUa 

and  spinal  cord  are  lell  intact,  <lne(  not  do  away  with  tlM:  ccintinuniic«  of 

respiration.     One  erauiid  nerve,  lis  we  nhall  Mm,  iit  winxially  iimk^rrn-d  in 

rtapimtiun,  vti..  the  vagus  iwf%'e:  hut  if  alli^r  r^-ni'ival  of  the  brnio  above 

tbe  medulla  both  vagus  nerve*  he  dividiil.  rat|ufation  :>till  goes  on ;  iudo«l, 

tbe  Kspiratory  impulses  proceeding  from  tbe  ceulre  are, though  in  a  ])eculiar 

way,  exaggerated.     Hence,  though  we  cnanol  put  tbo  matter  to  an  cxperi- 

ntal  IMl  by  dividing  every  sensory  nerve  in  the  body,  while  leaving  the 


478 


nifsfinATtoN. 


iDDlor  Derv«e  of  rM  pi  ration  iniacl,  eucli  nn  op^initioa  beinj;  praetimlly  iinM^ 
dble,  ire  may  infer  tlint  the  respiitilun'  impulnee  proce«liii)»  from  the  reeFHra- 
lory  centre  are  not  sininly  atlereat  impuUvd  reaching  the  centre  aluiiK  a*rerent 
uorree  aud  trans formen!  by  letlex  action  in  tlml  ceuire.  They  evidently  ttlan 
dflnovoAvm  tJM  centre  it^ir,  liaweTermuch  tiieir  chuaoMrs  maybe  aflbcted 
by  adfercnt  impulseit.  reai-'tiing  tlial  centre  al  tli«  time  of  their  heing  geaeT* 
•ted.    llie  action  of  llie  centre  is  automatic,  not  simply  reflex. 

S  369.  We  find  do  tu(|uiry  that  tlie  activity  of  the  centre  is  priifoundly 
intUifiH-«^  by  two  clawee  of  evmtA.  Tb<9e,  as  we  mijftil  exnent,  are,  on  the 
one  liuiid,  cventA  |>rtM]tidn>;  ohan|i:(«  in  the  'lualily  of  the  blood  distributed 
t<i  the  mi-<lulla  bv  the  lull  rtnlricle,  uipecially  ua  re^anU  its  frasek,  U>at  ia  to 
Mv,  evGiiu  niixliA-tMx  the  lutcnrhant:!'  inking  place  in  the  liinc:*:  and  an  the 
Mner  hniid,  nervouK  Jiiiptjiim  »tarii.-<l  in  viiriciuM  wny*  und  n-iu'liing  th<'  cctntre 
Along  varl<Hi»  uervoi  ur  nervous  tract*.     U  will  bo  convenient  to  cnusidcr  the 

AA'crent  iwrvnus  ImnulHCM  may  alftct  t1i«  centre  in  many  varioua  wmy*. 
Tbi^  It  hole  net  of  bn-mliiii);  '>r  of  taking  n  breath  iii  n  double  act,  oonaistutg 
of  an  iiiipiratiou  and  an  cxpinition.  and  tier\'oun  impu!***  may  MpeciAlly 
aff«-ct  the  <hh:  or  the  nthcr.  One  mode  of  brvalhing  inaydiHTerfnim  another 
in  ihv  depth  nl'  the  individual  breath,  in  the  volume  of  nir  taken  id  and 
givfin  ont;  and  norvoiii>  imfmlMa  mav  incrtMae  or  may  diminish  the  depth 
of  a  breath,  the  voliinic  of  air  tctpired.  One  mode  of  breathing  again  dtfmv 
fVom  another  in  Ihi:  rapi<litvnith  which  one  breath  suoceeda  another,  that  la, 
in  the  ntc  of  rhythm  ;  and  nervous  impulses  may  slow  or  may  quickt^n  tb« 
rate  of  rhythm.  Then,  aj^in,  combinalioD  of  edects  mi  numerous  and  varied 
as  almost  to  baffle  description  may  result  from  the  inffuonoe  of  various  ner- 
vous intpulses.  Emotions  inav  aflfect  a  sin^e  breath  or  a  long  senes  of  breaths, 
may  (juicken  the  rbvthm  while  making  each  breath  more  shallow,  or  tttMj 
at  the  same  time  ma^e  each  breath  deeper,  or  may  sloiv  the  rhythm  in  eJth«r 
Ok  one  or  the  other  manner,  and  may  liear  chiefly  on  Inspiration  or  oo 
expiration.  Moreover,  there  is  not  an  nflereni  nerve  in  tJie  nody  nhicti  by 
means  of  a fle real  impulses  pacing  alone  it  may  not  be  the  iuatrumout  of 
influencing  the  re§pit«tiiry  centre.  Of  all  the  automatic  ceiitm  in  the  body 
tlie  reaptratory  centre  is  the  one  wh«!»e  Independence  is  moHt  olucurcd  by  the 
the  repeated  alTcctti  of  aflerent  mirvous  impubee. 

ru,  tm 


KmNT  on  HK^NAtiiMt  OF  Swmeat  or  nm  Vmvt. 

Tlw  nKU*  WH  dlvldoi)  dI  Ibc  folDI  fntrkpil  i,    Thr  van*  hm  iitiUliinl  tij  imnii*  of  ■  Uin)»(tf~ 
toiuwM  lAilt  «  noflrar  IdIo  vIMli  tlw  ■nlmkl  (nliblli  ortBliial.  «  aboun  in  FIk  133,  Ihs  IcTSi 
lalUlwtnlnipl'*!''"'**  «t>  tt  aurlMl  qM  lit  iha  tainliour  uul  rtilii||  IB  «i|>lmli>ti*(lhui>lr  faliini* 
IfwpiBtlMi  IxcUuBi  ■  unlen^al  k    tCittnUon  Iwclni  M  b  uidaidiat  o    Tha  Isiwgniiliiklly 
klb  tntintu  c  N&d  <  owIbc  in  Ibo  «*Mp«  of  ■!>  (Mai  Ito  ■wwlw. 


TIIK    NKHrorS    IIECIIANISU    Or    REsrtKATIO.V. 


479 


ftnain  Rfllcniit  iwrv**,  however,  npix-nr  w  be  more  clwely  cmiinwlwl  willi 
il  ibn  Mbm :  ud<1  of  l)ii»C  titc  Ri'«t  ivmHinciinitH  iiinl  im|H>rUiut  iirc  tlic  two 
ni|u*  nrrvCB.  irhu'h  nv  hitvi-  iilrcnilv  nu'iilimii'il  in  llii*  niiiiK-ctioii.     Tli^ir 

bapMlUMO  M  Wi-ll  illunlralwl  brthi'  fnllnwiitlg  c\|HTini<'tlI*:    (f  onO  VIl^llH  Iw 

dividtd  is  ui  oMtDarv  WDV,  wiihoui  nriv  <|>i'i:'inl  {inrmiilion!'.  ibi;  ri»|)initii>ii 
(■  dlW  not  inBltrri«llv  cDODgrd,  or  it  jll.i mI  lutMinw  nlowt-r  >Fig.  139). 
If  hn\t  be  ilivid«l  i.Fig.  IJOj  it  lici.nin-  viry  >!•>«,■.  tin-  pHUHm  lictwi-on 
expindon  Hml  iofpinilioii  bt-iog  mnrkrdiv  pmlongiiL  T)ic  charni-irr  i^f  the 
'«>DtrEUir]r  riov«i»«iii,  inn,  it  nmrkvill}'  cbatigtsi ;  vnvU  n-Kpirniicin  i»  fuller 
*ih) drcptr,  so  much  m.  iiKlwd.  Hint,  iicrordiiig  to  Mint- olMTvrn.wItnt  Ia  lott 


KtTtrt  on  ltBaiiiiTii»  "f  liutios  -f  Burn  Vir.n  NiiMTn. 
Tk« con* »M (MiliMl  lallitwiiuii>v>*rie.  I».   TlwwcaiultiiinwtKrtoHvdlTMcdMK. 

*■>  rate  is  fitted  iu  extent,  llicamoiint  of  carbonic  acid  produced  and  oxvgt-n 
OaoMiRiMl  in  A  given  [icri<id  n-niiiining  afitr  divisiou  or  the  nerve*  iibou't  the 
*mn>n  as  wbeii  titwe  were  iiitacl ;  bul  it  is  undesimble  to  iiiaiu  too  mnch  nn 
Mm  •Hctnen  of  thu  cumpmmion. 

FtO.  ML 


■*  Usnunw  »T  OBnu  »nin'UTiMi  up  t>s  CarraiL  Ink  or  nil  V»m-»  Ta«wi. 
««•  aMaliiM  la  Uk  mow  war  m  Flvk  IK  l«.   SUmNlMlM  tt  tlw  tMU*  ta«M  at  k 
•III]  dufad  at  J . 

WlicD  Kftcr  divulpD  of  liuth  vogu*  ncrree  id  tbe  itcck,  llie  iDfldiilln  b«iog 

^intact,  tbe  contnd  flump,  thiit  ooun«cted  with  the  cenirnl  iktvoos  fvslem,  of 

■  of  them  is  slimulntwl  witli  K  gMit)«  interniutel  i.-iirreni,  the  I'lWta  «re 

■IwMfB  tbe  Mtne;  oDtt  of  two  rfiMilte  may  fnllow.  mid  tbat  whichever  of 


BtSPlRATlOS-; 

the  Inn  n^rres  be  used.     In  a  ceniiiii  nuuiber  of  com;*,  and  theae  inntr.  pet' 
Imiw,  lie  TWftnrdMl  as  the  more  topical  one*,  the  rL-a(itrutt(ni.  vrhich  from  the 
i)ivi»itiii  if  ilie  nervca  hud  become  slow,  U  ((Utckfued  Uffaio  <  Ft|;.  141),  aod 
with  i,^are,  by  u  projier  upplioatiou  of  the  *tinmlu«,  the  nunnul  reiiipintor]r~< 
rhj-thin  ruuv  for  tt  time  be  retlored.     Upon  ihe  oesRatioti  of  the  »timulu.->  th 
slower  rhytnm  returnii.    If  the  current  lie  iiicretued  in  «tr<!n^h,  ibc  rliyth 
may  in  smaiK  cime*  bn  (o  ■'.'twlerutt^l  ibnt  inn  pi  ml  ton  buginH  Itcl'uri;  thv  espini' 
tiuii  of  thi;  prcciiliiig  brentb  ia  completed  (Fig.  H2),  «nd  tbin  lanj  go 


rio.  Hi 


^ 


7L 


/ 

eimiLlTKll  Ol'  V*lll»    iJADIN-i  T.)   1  Vll'IIUlllBV    IHiH«*«, 

Thlicntvr,  nnllko  Uiv  luncedlof.  Hwobtaltitd  Iif  InwllUE  a  nmlleUiKni(li  tha  bodj  «all.  «■ 
UltBLan  (he  itUi'hnMrn.  >iiil  nlliu'liiiiE  ■  lei«r  lo  Ibe  iiL-cille.  i9cc)ISi  i  Tlia  l«nr  tliei  wItliMCk 
ConirullQD  of  ihc  dlitpUracni.  •<>  'liu'  liKlilrslltiii  bv^iu  nl  ■  kiid  and*  >l  b,  ciplnaoB  bqiJna  il  b 
•nd  null  ai  o,  Uio  Interval  bclman  c  &ud  ■  eormpnndltiii  to  th«  |i4uc.  SUmulaUnn  of  tba  nm 
bcslniat  X.  It  will  b«w(Dttvu upon  tilmu1iiUoiiIhDliifpli«iiiiTrtK*ortbp|«r«rteKtBloacli«IH<g 
ilMpraealluit  aplimtlotUBnconipleie. 

iinlil  at  last  the  diaphmgiii  is  brought  into  a  coDdition  of  prolonged  tciAUot, 
■nd  a  standstill  of  respiratioii  io  nii  exlreme  iii«pirnlory  pb&ae  is  tbe  rcniU. 
Oh  the  other  bund,  in  a  ccrlnin  number  of  ciml's  the  result  it  of  an  opuo*it« 
character.  Even  though  the  rcepinilion  l>e  already  slowed  by  divi«[oa  of 
the  nerves,  etimulatiou  produccA  a  still  further  slowiiij,',  tlie  paUM<«  beCwevo 
cacb  cxpinitiou  and  the  succeeding  inspiration  are  prolonged  i  ef.  Pig.  14-^). 
and  in  a  certain  number  of  cases  actual  standstill  is  brought  about,  but  a 
Btaadslill  of  a  kind  the  opposita  of  the  one  just  desoribM,  tluce  tho  dU- 
phragni  which  in  that  case  was  in  prolonged  l«tanus  is  in  this  aue  conipletaly 
relaxed  and  remains  for  some  time  in  the  condition  in  which  it  is  at  the  don 
of  an  ordinary-  breath.  In  a  cerlain  number  of  cases,  and  ihoM  arv  not 
uncommon,  tti'c  nwuli  is  intermeiliate  between  the  two  above  extremes :  the 
dinphracm  stands  ntill  in  a  prolonged  contraction  in  a  position  which  is 
intermeilialc  bewecn  the  height  of  inapiralion  and  expiration. 

T)m«  ranltA  nuggtvt  the  conclusion  that  the  thbus  norro  (we  iir«  dealinu 
now  with  the  main  trunk  nf  the  nerve)  contains  n^rent  fibres  of  two  kintb 
oonnectcd  with  (he  nvpiraKir)'  centre;  one  kind  augmenting  the  action  of 
the  ccntrv  somewhat  iu  tbt;  .<aniu  way  as  tlie  augincnlor  cardiac  fibres  au)^- 
racni.  the  beat  of  ihti  heart,  and  ihe  other  kind  hnving  nn  inhibitory  c&ect. 
Apparently  sometimc-i  the  one  and  sometime*  thi-  other  kind  is.  according  to 
circumstances,  moe>t  provokol  by  the  stimulation,  much  as  in  the  same  way 
as  stimnlstion  of  (he  vagus  in  the  frog,  which,  as  we  have  seen,  §  158,  is 
the  channel  for  both  inhibitory  and  augmenCor  cardiac  impulses,  produces, 
sometimes  inhibition,  •oitietimos  augmentation  of  (be  heart  beat.    To  affect 


TOE    NKRVOta    UKCUAXISM    OF    KBSPIBaTIOX. 


481 


ikthMTt  of  course  the  Mlniitstion  of  the  vakils  raunt  be  centrilbffal.difected 
ImHlbe  |ien]>liery,  wImt^ab  to  ailed  the  res  pi  rat  ion  it  nmat  be  oeotri- 
fial,  tpslml  to  the  part  of  tbe  nerve  eotiuci-iixl  with  the  bntin  ;  ami  while 
tbtHral  «ifbct  on  the  bean  of  onllnnry  mimulHii'iii  nf  tlie  vagiu  u  iiihibi- 
tba  WMnieDUtiOD  unir  oix-urriiix  In  ngwi'iiil  cil-hm,  llie  uhiot  cftmmOD  efibet 
(■nqmiMit  b  au^entali'iii,  tWi^b  iiiliiliilion  i*  not  unfrMiiientI}r  aval. 
V^  the  PX)KTinM>ni  m  f<)n(liii-(«il  no  iiii  nomiiil  iiiidcir  ihr  full  inQiMinoo  of 
(UonI,  *(iiiiiiliiti«ii  1)1  tlie  vngii*  goii«'rally  [inHlticcM  iiibibitii>n  of  reapirft- 
(IM,  pnihal>lv  bocniiiw'  ihn  clil'irnl  ri,iii)?n>  the  rrspinitory  centre  more  sua- 

TJble  t'>  iiinibilory  iiifliii-tKiii. 
9M.  \Vf  wiid  just  DOW  "tiie  acliuD  of  tbr  criilro";  but  the  respirntoiy 
Mtn  ii  n  il'iiible  ooe ;  it  givra  n«c  to  innpiratory  and  to  expiratory  eflerent 
ibmiIms,  BtiH  thoc  arc  aiilngonuiii;  th?  one  to  the  other.     If  hispinilorjr 
w   ripinilory  impuJMw  itMimJ  fmm  the  centre  at  the  same  time  and  in 
"|uk]  potency,  there  o(hi[(^   bo  no  breatliing  at  nil,  they  >irould  noiitrattta 
■^ch   i>iher'«    eficcts :  am),  indeed,  any  nmiiuni   of  inspiratory  inipulBO   is 
"■laiCoiiiBlic  to  n  siiuullaneow  expiratory  inipiiise.  and  rice  vcreri.     Henoe, 
"''  tbe  adeouate  aervioea  of  the  rcapinttory  centre  we  niigbi  extwct  to  find 
^^•t  eaeb  kind  of  afferent  impulse  asoeudinf*  tbe  vaKUH  aSeetea  the  centre 
'(>  a  double  and  opjui^ie  uiiy,  iuliibiliu);  expiruliuit  while  uugineulinj;  iiupi- 
'Vtitio,  or  iuhibiliu);  iuapiratinu  nhiie  au;;iueiiiiu>;  exptralinn.     If  ne  allow 
*^iuwlvea  to  g|)ealc  of  the  whok  n^Hpirainry  centre  a^  couaintii^  uf  two  parta, 
*^  tim  inspiratory  (wrt,  or  in^ipinitory  i^^ntre  •xiucerned  in  the  irtaue  of  iu- 
4|iraJnrr  impulaea,  and  Ibe  other  tbe  expiratury  )>arl.  or  expiratory  centre 
fwcemt.'d  in  tbe  iMue  of  expiratory  iuipuUt-a,  we  may  auppoae  that  tlieae 
(•tm  are  mt  related  to  each  other  that  afferent  inipuUn.  reiiebiu);  tbe 
Mdulla,  which  augment  or  inhibit  the  one,  necHMrJly  inhibit  or  au>;iuciil 
ika  other.     We  mxil  {vrhajin  hardly  add  thiit  of  tbete  two  centres  we  .diould 
•Ip«ct  lo  find  the  iufpiratory  ecnire  the  dominant  and  tbe  most  rcsponiivo 
OM;  in  twrmal  brcalhinf;  it  comes  alnioit  alone  into  obviou*  uw,  aince  na 
*e  have  «evn  the  expiratory  muaelea  have  then  a  very  flight  Inflc  only,  tbo 
(icat  beinjt  enipliea  chiefly  by   elaatie  reaction  :  and,  e|M?aking  generally. 
IiKathtDi;  in  is  tbe  firtt  conaidersiion,  w«  breathe  out  nuiatly  bwauw  we 
kmre  already  brtalbed  IL 

There  are  many  facta  which  support  this  view  of  the  double  antapmistie 

action  of  aflerenl  respiratory  impulaea.     If  tbe  central  end  of  the  siipeiior 

larrnicefil  bnutch  of  die  vaKua  be  Hliuiuluied  the  elTecta  are  much  more  coD- 

•unt  than  tbui»e  <>f  atimuhUinK  (he  main  vagus  trunk.     Wbelher  the  main 

^Arunk  of  tbe  nerve  be  nrevtoualy  aevered  or  not.  (he  reault  of  centripetal 

BKimulation  of  the  iuperior  lap'ngeal  branch  in  always  in  the  direction  of  a 

^buwiaKof  tbe  rmpiration  (Fig-  143);  and  thia  may  by  projier  aiianilatiou 

Fba  earned  ao  ftr  thai  a  coaipfele  »tand»till  of  r«»piratii>ii  tu  the  pliaw  of 

r«sl  i*  brought  almut.     While  the  main  trunk  of  the  vagua  ooutaina  Rbrea 

iif  twu  kind*,  both  aujimi-nlor  and  inhihiUirv  ui  inHiiiration,  the  au|>erior 

laryomal  breoch  npp<'ani  to  (-''Ulain  nnc  kitui  unly,  tlniw.-  which  inhitiit  in- 

Stratiua.  If  now  while  ihia  )'X|H-nmi.-nl  u  being  conducted  on  a  rabbit  the 
idonieii  be  wnlclx-d,  it  will  be  aei'u  that  the  inhibition  of  inKpirnliun  la 
acconifianii-d  hy  a  cmtrarlion  of  tbe  abdominal  iou>clti>.  that  ia  by  an  elfort 
at  expiration  -.  iIm-  atimulnlion  of  the  Dcm  whilu  inhibiting  Tvnpimli'm  pro* 

Ivukea,  ti>  a  certain  extent,  expiration. 
i  367.  That  the  trunk  of  the  vnf:iia  is  the  channel  of  these  two  kinda  of 
ImpulM-a,  of  a  niutaally  anlag4>iiii^tie  character,  ia  further  ahiiwn  bv  apply- 
Inj;  what  may  be  considered  aa  natural  Mimiili  lo  the  ending*  of  the  nerve 
in  the  lunjt*  ;  and  the  reaulls  ao  obtained  have  an  eapecia)  valui>  ainoo  the 
artificial  Mimulation  of  a  nerve  fibre  at  a  [tart  of  ila  courac  by  menna  of  an 

91 


482 


electrii'  forrent  U  at  Imt  n  r'llgli  prm-esiii,  by  wliich  w«  caonot  how  to* 
tnore  tliau  appruximntc  to  tlii:  rwult*  uctutiUy  taking  pUc«  in  ln«  livJi 


Swmso  a*  tuviaAtioa  vt  finiicLinoei  at  Suruio*  Laimoaiu.  Knni 

TM«ti)n*wMnliia1iit>Iln(hiimneita)'**>^P'  DIMM  141  ■■><)  lk«  bM«tt  h*M  Um tam 
mMOIng  u  In  tbaM  Igure*.    SilBulatlao  liOftiu  at  2.  aad  mdl  at  p 

body  wbcn  the  nerve  is  stifniilat«d  nt  its  eadiDx*  by  nattiral  utiniiili ;  u 
the  Approximation  ia  perbaiH  len  in  ihe  cise  of  tb«  exiiuiaiuly  Moiili* 
respiratory  centre  than  in  many  olher  cases. 

Flo.  IM. 


^ I i_ 


_i I I j_ 


-I. 


B 
mrwv  or  DnmtMN  uiB  Couurw  •»  Ij^mi.  illub.1 
BKb cniTM an ilewtlbfil  hyo  let*?  MIWIibI,  ki  ilalcl  l>|»M,  to  ■  illp  at  llw  dltptantaM 
rabUl.  A  ^wUMlloli  «f  llie  i)l«|*ni(ai  lliu|iln>d(iii>  nlut  Uiu  Inret-.  during  raluUlon  oTU 
itt*ph»t<n-*>>"l>**' AiUt-  la  A.  (ho  tecimUclofnl  u  j.  Ihr  hplEhi  0/ tiniintloii:  ■  t<««iil 
lomdinliic  whiehiha  lenr  cwIimI])' iliiki  until  an  laoiilnitloa  (i  ■tvts  pDRuirul  mii'i  M*  Bk  J 
a.  Uisitactwatoclowilfliiiiooiiilor«irl**U(n.':  UM»Ci)lo«r  luaornil  iiuiiini^iau. 


4 


THE   NERVOUS   KKCnAyiSU    07  RKSPIBATION. 


483 


If  in  KB  animal  m  wliich  «  i-areful  L!ra|ihie  record  of  the  rwpiralnry 

>m<>V«nM;nU  U  being  lal(i:ti,  th«  truchcu  be  sudilenly  4!liwe>d  iit  lh«  «iiiiiniil  at 
■ui  in«|>intion,  thu  rcJiiU  ii  »  piiiiMr  Ix-forft  the  ouoCMding  iii4  pi  ration  folluwH, 
llinl  is  U>  my,  ■  juutinl  or  U-m|>i>rary  inhibition  of  in*piriilioii ;  nml  if  iliirii)); 
Moti  iin  i'X|>criincnt  on  n  mhith  m  curvo  he  bikvn  ]>y  iu«nnit  of  the  iw)Ititvii 
slip  of  (Ik-  iliaphniifni,  ^  '^2V,  ii  will  be  «vcii  { Fig.  144,  A)  that  tlic  «Ii|i  vlon- 
giilc«  Homcwhiit ;  ihat  i*  to  my.  previously  in  n  t!tat«  of  slight  tonic  eoBtmc* 
tioi).  il  cluuigro  ill  the  <lirvctio:i  of  cxpirution.  If,  ou  ih*:  other  hun<l,  the 
trnchcu  l>c  ouddcnly  closmt  M  th«  i>ii(l  of  »n  expirniion  ( Pig.  14tt.  It),  when 
the  lungM  have  returned  to  thwr  emptied  condition,  thu  n«iilt  i»  an  increaea 
of  the  E«4|itent  inapi rations,  that  ifl  to  say.  an  siignK-ntniion  of  iiwpiralory 
imiMibeB.  If  the  che^i  or  if  the  lun);  only  be  geatljr  intlatod  a  temporary 
ceasali'-n  of  nil  iHi]>iratiuii  may  he  produced,  accompanied  sometimes  by  an 
Attempt  at  expiration.     If,  on  the  other  hand,  air  be  sucked  out  of  tiM 


-L. 


.*- 


_kU~ 


I    t^ 


Ktnxn  or  Sipumi  tsruTiuvs,  riiuriti  Vixtuaiiot'  (llut>,> 
TtM  limn  curv*  la  dMtiltrod.  u  In  Pij,  tu.  by  •  limr  stMoiMrf  lo  s  illp  iif  ih«  ^Ikfkngm.  Tbe 
iinntMimitKmitbv  InniUoiu  from  i  ta  ;.  wlilcli  w*n  Inwiii  wlllioul  aur  ■Uaiii|<  lo  diaw  lliv 
klroaliiiMeh  intiaiiun :  tmeh  Hhihi  llili  aarrD  <loiial«>  an  tnlUilnti,  it  wID  M  otMned  ihai  n> 
Uio  loMloM  an  oinUiiuvJ  Uw  nfplMorj  manauoH  uT  the  dlitfilirktin  arv  xndtnJIr  ■■  knocKol 
down." 

chest,  or  if  oiM  lung  bi-  nisdv  lo  collapse  by  puncture  of  one  pleural  cham- 
ber, a  prolonged  inapirnliou  is  the  frequent  rejult,  tlie  diaphragm  being 
thnmo  into  a  prolonged  inspiratory  tetanus.  If  the  liini^  are  repealcxlly 
inllate*!,  without  any  meaiu  bciog  taken  to  draw  i>iit  tbe  air  all«r  eadi  infla- 
tion <FitC-  H'^).*  procedure  which  we  may  s{>Mtk  of  as  positivtr  veiililatioa, 
the  retiilt  in  iliat  Uie  iusptralory  etforl^  are  diminished,  and  if  the  ventila- 
tion ta  continued  mar  cease  alto|^ther.  If,  on  the  other  h«nd,  air  ii  repeat- 
edly sucked  out  of  the  lunga.  without  any  c(irresnondi»;t  inllatioiio,  negative 
vtrntilaliun,  the  unpiratory  eni)rt9are  increased  (Fi|;.  t4ti|,  and  thi>  iiicrsMa 
may  be  nucU  u»  to  briiiic  tlie  diaphragm   to  a  state  of  leCaiiun.     And  in 

Snemt,  though  i^'vurul  coiiiplicatioas  occur  which  we  cannot  <liKcii)«  burv, 
I-  ri'atilt.H  of  inllaliou  of  lliv  lungn  on  the  one  band  and  of  rinction  or  »>!- 
la|><H'  'if  tbr  liiiig:>  on  lilt-  oib<,ir  hand.  *how  tbut  tlic  mi<re  inflation  or  por- 

X rather  the  tmrn-  dUtifii«i»n  of  (he  lung  ten<U  to  inhihjt  inspiratory  and 
in  rxpiruttiry  itn[iiil»s,  while  colla|WO  of  (hv  lung  tenus  to  inhibit 
•xpinUorjr  ami  tn  dt'vrl.tfi  iti>|>iralory  impulwM,  the  ulbct  on  ibo  inspiratory 
iiapaltM,  M  might  he  <'X|H-c[c'i  from  the  domioanoo  of  the  iiupiratory  por- 
tion of  the  centre  Ix-iug  niurc  nmrkivl  thao  the  dffiict  oil  thv  expiratory 
impuWs.  That  the  iii«truiuetil  by  which  tboM  eflecla  are  nroduoed  is  the 
vague  nerve  is  shown  by  tbe  fad  that  they  arc  no  longer  distinctly  rvcot;- 
niuible  when  both  vagus  nerrea  are  divid»l,  And  (hat  the  results  are  due 
to  the  mere  mechanical  expansion  and  coltansc  of  the  tung  in  insulBalioa 
and  collapse,  and  not  to  any  chemical  influence}  exerted  by  tbe  larger 


484 


KESPIRATIOS, 


amount  or  amftller  Rmount  of  air  preseDt  in  the  lung  in  the  two  cases  in- 
creasing or  dimiDishing  the  absorption  of  oxy^n  and  escape  of  c&rbonic 
acid,  is  shown  by  the  fact  that  the  results  remain  in  their  main  features  tbe 
same  when  some  indifferent  gas  such  as  hydrogen  is  used  for  inflation  in- 
stead of  air  or  oxygen.     We  infer,  therefore,  that  the  expansion  of  the 


F»i.  mi 


-^-vWWW\A 


ElKIi.-!^  ur  KEIT-ITEII  SlCnilNr.  tlV  THE   I.INi.S.      NlIllAtlVE  VKSTlLATillN.      (ilEAD.) 

Till.' pun 0  corrtsjioiulEt  i.'XHCI1>'  to  t'lg-  H'l,  uxcn^lit  Thut  iJii!  Uuigs  lire  niiUJ^-rliHl  10  repeated  lUctiona 
H'llboiit  «)rtvi>iinUIiiK  iiillHliim.''.  Ttiu  n.-.iiill  Ik  Iliat  lliu  liis|ilm[!niii  nn:  n.'K'ilt.il  Id  uicb  a  way  u 
to  leoil  iiliiio't  to«n  liisi-lnit'iry  lelmiiisof  llii;  'llni>liniEm. 


puliuonary  alveoli  in  some  way  or  other  an  stimulates  the  endings  in  the 
lung  of  the  pulmonary  bmnchea  of  the  vngiii'.  that  impulses  are  generated 
which  ascending  the  vagus  trunk  inhibit  the  inspiratory  processes  in  the 
respiratory  centre ;  and  that  conversely  eolla|>^e  of  the  lung  similarly  gen- 
erates impulses  which  are  augmentative  of  iusjiiraCory  impulses.  And, 
assuming  on  the  strength  of  analogy  the  existence  in  the  vngus  of  two  sets 
of  fibres  we  may  buy  that  expansion  stimulates  the  endings  of  the  fibres 
which  inhibit  imtpiration  and  concurrently  tend  to  augment  expiration, 
while  collapse  stimulates  the  iibrcs  which  inhibit  expiration  and  augment 
inspiration.  The  respiratory  pump  mav  ihiis  be  looked  upon  as  a  self-regu- 
latmg  mechanism  ;  the  exjiausiun  of  the  lungi'  which  is  the  result  of  the 
efferent  inspiratory  impulses  tends  to  check  the  issue  uf  these  impulses  and 
to  inaugurate  the  sequent  expiration  ;  and  the  return  of  the  lungs  in  expi- 
ration tends  to  set  going  the  succeeding  inSi>inition. 

The  regulative  influence  exerted  by  impulses  normally  ascending  the  vagus 
nerves  is  further  shown  by  the  following  striking  experiment :  As  we  have 
already  seen,  the  brain  above  the  medulla  may  be  rcni'ivcil  without  any 
extraordinary  change  in  the  respiration  taking  place.  Wv  have  also  seen 
that  when  both  vagus  nerve*  arc  divided  the  respiraliim  is  slower  iind  deeper, 
but  is  otherwise  regular.  If,  however,  after  reiuoval  of  the  brain  al>ove  the 
medulla  both  vagus  nerves  are  divided,  if  the  resjiiraturv  centre  be  cut  off  at 
one  and  the  same  time  from  impulses  pat^in;r  down  frutn  ihe  hi<.dier  ports  of 
the  brain  and  from  impulses  asceudiiig  ihe  vagus  nervi-:^.  the  result  is  that 
the  respirations  take  on  the  form  of  a  series  of  lon;;-<'oiittiiiicd  inspiratory 
spaems.  It  would  seem  as  if  there  were  a  tendency  in  llic  ret^piralory  centre 
to  go  off  into  tetanic  inspiratory  explosions,  that  this  [endein  y  is  held  in 
check  by  impulses  from  the  brain  when  the  vagus  nerves  are  divided,  and 


TUB    SEttVOL'S    MECUA^ISM    OF    KKSPl  It  ATION. 


485 


'  h^  Mftubra  aliKii;  i)h>  vb|£ii>  iH-r^-ea  when  ihe  lintiii  i>  reniuveil,  lull  iiin-U 
vubno  MJequntr  rluvks  wIh-ii  im)HiUf»  from  liuth  Miurccn  ur«  cut  off  iit  itio 
matlitae. 

t368.  HyiwrtboM*  have  bevn  pui  fomiinl  to  «zplidn  the  cbatifntt  in  t)i« 

rMftatorr  ivntrp  which  Iciul  to  the  rhylhrniir  iliat'hiirKi*  nf  in^iiirntury  nnil 

•XpiiWorr  ini|iulwii  and  tbc  fuHhirr  I'hniip^  which  ronult  I'min  ihi-  nilrcut 

of  ujtnti'otiiig  iiRil  iohihitorv  iiii|>ulM»;  hiil  thmc  m  yvt  rt'riiiiin  inrrr  hrji-j- 

^hww.  mil  it  wiHiliI  Hi>t  1m!  pmAinbk-  todiscuw  ihcni  liirM-.     Wi:  niny  mid 

ti^Mi  Ihiiugh  tin'  »nal<>!;v  of  the  cnnJmr  nfrvoun  nn.-chttnwm.  in  whioh  wr  cttii 

■Ostarakall^  dttlJRgtiuh  Iwtwccn  itneint^nl'^r  and  inhibitory  fibm.jii!>tilii!:t 

5"  to  ifwakiRg  uf  Kugmentfrmnd  inhibitorr  »nd  rapinitorr  Fihrcn  tie  cxislinc 

ia  Uw  T^us  aem,  wentv  not  tu  yot  nhl«  to  difttinKuish  Ihem  bv nniitumical 

"■Nlvidft.     We  may  further  ndd  that.  «o  «xqnint>>Ty  senaitive  ie  the  mpira- 

***';3r  «ott«  to  th»e  Bli«r«ni  impulMse  tliftt  stimuli  loo  elight  lo  prndiira  any 

*f'pniciablp  «l1#cl  when  Applied  to  aflcrpnt  nerves  connected  with  an  i>rdiuary 

***ttn;  such  u  u  spinni    retlei  centre,  mnr  produce  marked  etlet-td  on  the 

'*"|Mmlory  centre.     For  inslaDce.  the  Tceble  electric  current  which  is  de- 

'^Iftpr't  whew  the  out  eiid  of  a  divided  vagus  is  replaced  in  tbe  wound,  (be 

*^^^.^|il  belwM-n  the  cut  end  and  ibe  lougitudiunl  Mirface  of  the  nerve  beinjf 

^Voml  ilir'>ii|;h  the  hl<Mkl  or  lymph  of  the  wound,  ia  ofleo  lufHricnt  to  de- 

**1b|>  inhihii-jry  iiupulMSL     A^in,  when  tbe  eouncelion  of  thu  rt^pirntory 

^«Btre  with  the  lun;pt  through  the  vagus  nerves  is  aboli.ihed,  nol  hy  tH'ctinu 

of  llie  nerv<>«,  hut  by  [ntft'inn  huth  nerves  ai  aome  pitn  of  Lhe  courw  nf  i-ach 

Bcrrv  (an  operation  wbtch,  while  cuniidrivly  hhickiiitc  the  iiMsageof  impiilM!* 

liomtl  ^*  nerre  fibrat,  doui  not  it^if  net  u  a  Htiniuliii),  the  eHfitct  on  the 

tvpintarr  RioTeincntii  it  niucb  more  in  tlie  dirv<rlton  of  iiu'riikiing  iind  pro- 

loD^Og  the  in*}iimtory  acl  than  «f  Klowinj;  the  rhythm.     Hence  it  wotild 

ippCT  that  what  we  have  prvviousir  duscribed  n»  tliv  result  of  dividiui 

both  vague  nerves  i*  partly  due  to  the  blockin);  of  natural  impulBes  and 

pwtljr  lu  the  sertiftn  of  the  oervfe.  and  posnibly  t«  electric  curreul*  <le- 

veloped  as  8ii]ci;estcd  abore,  acting  as  «tiinult  s»d  thus  giviD][  rise  to  artificial 

inpulwa. 

(  380.  The  double  or  allerinile  n»i>iratury  action  of  tbe  rajius  nerves  on 
whkb  we  have  dwelt  tibove  muy  Ito  iiikeii  as  in  a  j^ieral  way  illutilrative  of 
tba  nanaer  in  which  other  atliirent  nervee  and  variuiiit  \nnti  of  the  cerebrum 
aiC  tnabled  to  influenee  reapinitiun.  Am  we  have  ulrt-udy  onid.  and.  indeed, 
know  from  daily  ext)erience,  <>f  all  iht^  n|nrchicul  nervous  ouilres  the  lespirtr 
toTf  omtre  i»  Inc  one  w  bich  i*  m»cl  fr<'<(ueiitly  and  most  deep);  aflbcted  bf 
B«rmus  inifiuljMa  iVom  varioue  iiuurleo'.  Bi^iiiloi  the  chaniNS  brought  about 
hf  tbe  will  (and  when  we  brualhe  voluntnrilr  we  probably  make  uiw  to  aome 
•aWsl  of  the  noniiiil  nervou*  miii'hinvrv  of  n'^ipiriition.  working  tltrouvh 
tbi*,  rallier  ihaii  siMiding  in'li?|><-»d<-ut  volitional  irti|>uliiM  dirtTt  to  tlie  dia> 
pbr«gni  and  olhvr  n-«pirRlory  muM-lct),  we  find  that  emotionK  and  juiiiiful 
BMWfttittn*  alter  profinindiy  the  cliaractcr  of  the  Rvpiratorr  nioveiix-nt*. 
Ami  lhtMit:h  ibnN.'  c ITccIm  may  he  partly  indirect  (the  emtXion  modifying  ihe 
rt-l)«at  or  the  timun  arterive.  and  s»  inlluencin);  the  flow  of  blood  thn>ugb 
riBpiratnry  centre),  th«r  are  chicHv  duo  to  the  direct  action  of  nervous 
[miIhs,  reaching  that  centre  fronu  Wher  psrU  of  the  brain.  So  also 
impiiltai  fnini  almost  every  eentieot  surmee  or  pnaaing  along  alinosl  every 
MBSory  nerve  may  ntudily  respiration  in  one  direclwHi  or  nnother.  Tliic 
lafloence  iu  this  way  of  Htiniitli  applied  to  tbe  akin  is  well  known  to  all ; 
bttt,  perhaje.  itext  to  the  vaguii  ibe  nerve  moot  clutely  oounecled  with  tliC 
resplraiory  wnire  is  lite  flfih  nerve,  branches  of  which  giianl  the 
nvplmiory  rhiinnels:  the  -ili^thteiit  mi  mu  In  I  ton  of  tbe  iimtriU  »l  once 
thtb£Mthinj;  an<lmii»t  lh!«|ueutly  iirnats  it.    TbeellccUof -aiinuli  of  rariwis 


ih  tiK  m 

uatal  I 

affects  ■ 

^ariwis  M 


486  BESPIRATIOS. 

Strengths  brought  u>  bear  on  various  nerves  are  very  varied.  Sometimes 
the  result  is  an  increase  of  inspiration,  and  that  either  by  a  quickening  of 
the  rhythm  or  by  an  increase  of  the  individual  breathe  or  by  a  combination 
of  the  two.  Sometimes  the  result  is  inhibition  of  inspiration  accompanied 
or  not  by  an  increase  of  expiration,  and  sometimes,  as  when  the  stimulattoa 
causes  a  cough,  the  expiratory  rexulls  may  be  out  of  all  proportion  to  the 
nioditicalions  of  inspiration.  While  in  the  case  of  some  nerves,  tor  instance, 
as  we  have  seen,  the  superior  laryngeal,  and  it  is  said  the  splaDchnic  Dervefl. 
the  effects  are  exclusively  or  at  least  chiefly  inhibitory  of  insniration  and 
augmentative  of  expiration,  that  is  expiratory,  and  in  otters,  perhnpe,  chiefiy 
augmentative  of  inspiration  or  inspiratory,  in  the  case  of  most  uerreB  the 
effect  may  be  according  to  circumstances  either  in  the  one  direction  or  the 
other.  Perhaps,  as  a  rule,  weak  stimuli  tend  to  augment  and  strong  to 
inhibit  inspiration ;  but  the  effects  of  artificially  stimulating  sensory  nerves 
are  complicated  and  often  confused,  because  powerful  afferent  impulses  by 

fiving  rise  to  pain  may,  through  impulses  generated  by  the  pain  itself  anc) 
escending  to  the  medulla  from  the  brain,  act  in  an  indirect  as  well  as  in  a 
direct  manner;  and  tiie  prominence  of  the  indirect  painful  impulses  will  in 
any  experiment  depend  on  the  senesthetic  used.  We  may  say,  however,  that  in 
all  cases  the  effect  is  very  largely  determined  by  the  condition  at  the  time  being 
of  the  respiratory  centre  ilselt ;  ami  that  is  in  turn  determined  not  only  by 
things  which  affect  ila  nutrition,  such  as  the  character  of  the  blood  circu- 
lating in  it,  but  also  by  the  nature  and  amount  of  the  other  afferent  impulses 
which  are  playing  upon  it  at  the  same  time.  Thu.i,  as  we  shall  presently  see, 
the  etTect  of  a  stimulus  applied  to  tlie  vagus,  when  the  respiratory  centre  is 
inndefjuately  supplied  wilh  arterial  blood,  is  nut  the  i-anic  when  the  centre 
has  its  normiil  supply  of  normal  blood.  So  also  a  sliniulus  which,  applied 
to  ihe  vagus  or  I<)  another  nerve  in  iin  intact  niiimal,  simply  quickens 
inspiration,  iijiplied  in  an  animal  wbifc  ct-rcbnii  hemispheres  have  been 
removed  will  cull  forth  a  pnilon^icd  tetanic  inspiratory  jiiisp.  The  respira- 
tory crntre  reFpon<ls,  iti  fad,  in  ihc  nuist  iutricnlr'  iiud  varied  manner  to 
nervous  impulsi-s  proceeding  from  all  parts  of  the  body,  and  thus  deli- 
cately ndjuslM  the  working  of  the  respiratory  pump  to  the  needs  of  the 
economy. 

s;370.  The  complicated  nature  «i'  ilie  respiriilory  centre  i.-'  further  shown 
bv  the  fact  that  it  iipjiears  to  consist  of  tmi  inlenil  halves  wliieh  normally 
work  in  unison  mid  yet  niav  l>e  made  to  work  iude|)ciideiitlv.  If  the  medulla 
oblongata  be  carefully  divl<k'd  in  the  middle  line  re:'pit'u[ii)n  may  continue 
to  go  on  in  quite  a  itorumi  fashion,  if,  however,  oue  vagus  he  then  divided, 
tlie  re!'}iiratory  movomente,  both  costal  and  diii]>lir:igninli<*.  on  the  side  of  the 
body  on  which  division  of  the  viigiis  Ims  liiken  place.  becTiie  slower  than 
those  on  the  other  side,  so  that  iho  two  ."ides  ;ire  no  lou^'er  syuchronus ;  and 
a  stimulus  (Hinfincd  to  one  viigus  utliTls  tlie  respiratory  movements  of  that 
side  of  the  body  only.  So  also  a  seeliou  ef  a  lateral  hull'  the  cord  below  the 
medulla  stops  the  respiratory  miivenicnis  on  that  siile  alone. 

§371.  Besides  these  nervous  inHuencfs,  however,  there  is  another  circum- 
stance which,  perhaps,  al>uve  all  iitliers,  atf'eels  the  res]ur!itory  centre,  and 
that  is  the  condition  of  the  blood  in  respect  to  its  respiratory  changes ;  the 
more  venous  I  leps  arterial)  the  blood,  the  greater  is  the  activity  <i(' the  respira- 
tory centre.  When  by  reason  either  of  ntiy  hiiidrjuiee  In  the  entririee  of  air 
into  the  chest  or  other  interfereuce  with  the  due  inlercliunge  between  the 
blood  and  the  pulmonary  air  or  of  a  greater  respiratory  activity  of  the  tissues, 
as  during  muscular  exertion,  the  bhxid  becomes  less  arlirial.  more  venous, 
I.  c,  with  a  smaller  charge  of  oxygen  and  more  heavily  laden  with  carbonic 
acid,  the  respiration  from  being  normal  become.-^  laliore<l.     \Vc  loay  speak  of 


Ttre   XERVOUH    MECnAMSU    or   RBSPIBAT10X. 


■187 


I 


I 


I 


tbiag  as  eitfiH'ta,  nm)  sav  iliat  ihiM,  wh«n  (lie  bK>o(i  is  insufficiently 
mierBtlhed;  jMrnx  ini»  ilyronaa,  nn  iiiterni«diale  aiujff.  in  which  the  rtsfiira- 
tAiry  moveineniii  Hr«  .■•iniply  vxiiggerHict),  beiti);  known  us  hj/jtetjiHoa,  Tbc 
nKHlifinalionjt  uf  lirt-Blhiiig  i)iu»  chumkI  by  d«riHi.iit  urterialixalioii  of  lilourl 
lire  viipcci«)l}'  chaniclrriM^t  hr  an  incrt'-iwc  in  the  lotat  boer^v  uf  \)m  napira- 
Iiin>'  iniptil»n  Ki-iicrntcit,  ami  in  thia  n-opvcl  ilitlV^r  iViiin  the  nuidiliciiiiotii* 
reuniting  fniiu  iiili-rfrrrnci;  with  Ihc  ncrvnii*  nrnuignnciiti)  nuch  ait  thiwe  f<il- 
luwin^i!  ii|Hin  section  nf  tbo  rttgii*  iwrvif,  in  which  ciiwv  n»  wc  have  WH-ii,  iho 
rhvlhm  i»  much  more  proloiirHllv  atlcflrd  ihnn  llic  Jinnniiit.  In  ilynpnceK 
lln-  hreatliinp  ts  frequpRttr  tjuickcr  an  well  ns  ilccper,  then.'  n  en  iiictx-iiiw  in 
1\m-  Hum  of  cflrrent  trspirntary  impiilm^.  and  the  uxpiralorr  iropxiWi!,  w  hich 
ill  uornial  mpiralion  are  very  slifiht.  acquire  a  pronounced  importance.  As 
thv  blcHxl  boeonwx  in  ca»eN  of  obslrucliou  Ie8<  and  Icm  arterial,  more  and 
more  venous,  the  diechiu;ge  from  the  reepiralory  centre  becumce  more  and 
more  vehement,  CImI  instead  of  confining  it^lf  to  the  Uiiial  tracts  ajid  paee- 
tag  (Idwu  to  the  ordinary  r^^ipiratorr  mUBcles,  ovorflowe  into  otiter  traela  and 
puts  intu  action  other  muHclea.  until  there  is,  perhaps,  hardly  a  muscle  in  the 
body  Vfhich  is  not  made  to  feel  its  effects.  The  muscles  wiiieh  are  thus  more 
and  more  ihmnn  inf>  action  aie  especially  thoae  teiidinK  to  carry  out  or  Ut 
snisl  expiration;  and  at  last,  if  uu  relief  is  alForded.  the  riolent  but  still 
definite  resniratory  movemetiis  give  way  to  ueneral  convulsions  of  llie  wluile 
Ixxly,  w'hicD.  howi-vcr,  have  to  a  certain  extent  an  expiralon,'  character. 
With  (lie  oniN-t  of  these  ccmvuluons  dyapnoea  is  said  to  have  pui«ed  iiiKi 
iitp/tyrin.  By  th«  violence  of  these  ooavuMons  the  whole  nt^rvouH  xyatent 
ItrconMv  exhausted,  tho  onvulniona  cesM,  and  death  is  usherol  in  through  a 
lew  inl'rcipii-nt  and  Inng'ilrawn  brcatlis :  but  to  thin  maid-'r  we  iihall  return, 
TImi  effect  of  vcnoii«  blond,  then,  ix  to  augment  all  thoik*  natural  cxt>l(i#ivc 
dee<>nip<i*ili<iii<ol'  (he  fulwtancc  of  the  centrul  ncrvHiii  Hvntcm  which  give  riw 
to  respiratory  inipulM^;  it  incrunMv  their  amount  and  aW  ()uick«Di>  their 
rhythm.  TIio  latter  chiuige,  howcA'cr,  it  much  Icm  marked  than  the  fciriaer, 
tbo  rtvpiralion  being  much  more  dec|>cmvl  than  hurriol,  and  the  several 
n»|>irtitorT  acts  are  n«rer  ff  much  hiislcned  as  to  catch  each  other  up,  and 
6o  (o  )>roduce  an  iuspiraiory  tetanus  like  that  mnlting  from  stimulation  of 
the  vagu>.  On  the  contrary,  especially  as  exhanstiuu  begins  to  set  in,  (be 
rhythm  bec<omea  slower  out  of  proportion  to  the  weakeiiin);  of  the  individual 
tuoreraents. 

S  878.  Tii«  question  naturally  ariwe,  Does  this  condition  of  the  blood 
affect  the  substance  of  the  central  nervous  system,  that  is  to  say,  the  respira- 
tory centre  iu  thd  medulla  (and  the  subsidiary  spinal  uervons  mecbauisms) 
directly,  or  does  it  produce  its  effect  bv  stimulating  the  jieripherul  emU  of 
oiftfent  i>en,'es  in  various  jMirla  of  the  ^dy,  and,  by  the  generation  there  of 
aflbrent  irojmUes,  indirectiv  modify  the  action  of  the  central  nervoiiB  ^vsteni  7 
Without  denrtng  the  potPihility  iMt  the  latter  nio<le  of  action  may  lielp  in 
thv  matter,  m-  r(-gurilr>  not  only  the  vajiUR,  hut  all  alferent  nervts,  ttie  follow- 
ing faclji  utrf.m  to  shim'  that  the  niaiu  vfftvt  'n  pniducMl  by  the  direct  action 
of  the  bliHid  on  the  e<.'nlral  nervottn  svittcm,  and,  imteH),  on  the  mcdullaiy 
rapirulury  <H'ntre  it^tf.  If  thi^  n)>inHl  oinl  be  divided  l>eIow  the  miiluliii 
obloogHta,  and  l><>lh  vagi  be  cut,  want  of  pn>|H-r  acrulion  of  tbf  hlood  ■till 
nrodiiceM  an  incn-a»-«l  activity  of  the  rw|>imtory  centre,  lut  shown  by  the 
incn-aM^l  vigor  of  th«t  facial  rc^'pinitory  movcmcnti".  If  (he  nupply  of  IiIixmI 
be  cnt  olT  (mm  the  im-ibilla  by  ligature  nf  the  carotid  and  iutervrrlebral 
arteries  dysima-a  is  j>riHluced,  though  the  (iiwrwtion  prodmv  at  first  no 
cliange  in  tlie  hh>od  generally,  but  limplv  nnecu  the  n^>i^l^•rv  condition 
of  the  nie<lulla  itself  l>y  cutting  off  its  hi uu<l- supply,  the  immediiile  ri-sult 
of  which  is  an  accumulation  of  carbonic  acid  and  a  |>auci(y  of  availnbl« 


tof  that  r<4^inD.     IT  l)iO  Mum)  in  the  rnnrti'i 
nliDVc  lliir  iiormal.  n  <W*\taiK*  x*  |ir»<lu(Y<l 


oxrgtMi  III  inp  n« 

•rti-ry  in  uii  nnir    

whicn,  though  iipimrentlr  not  niiilv  ii i<-i)iic-iil  with  lltu  ilTAinnrii  i!«iiw>l  hy 
ini|Hirfrct  iirlt-riali/alioii  of  ihi-  lilooil,  "hunrs  thai  lltc  Cuii  high  tci»|H.'nitiit 
of  the  lihxiil  iliriTllv  iilfiM-l*  l\n-  iii-tivity  ol"  lliv  rcjipinitorv  wiitre.  Wo  ma*— ^ 
oUR'hiilf.  ihcn'r^'ri',  ihnl  ihi.-  <.vii<)itiiin  of  the  hliioJ  ntlocta  ntfpiretioti  l><-^ 
acting  iJirwrlly  oti  ihu  rt»i>initc>r_v  c«nt«i,  Moroovtr.  it  fa  tho  nwiliilian— ^ 
centre  which,  at  till  vccule  iu  uduU  aniraula,  is  atTcctotl  by  th«  too  vi-rimi  ~ 
hload,  eitice  iiflcr  divisioD  of  tho  »piiml  oird  bp low  tho  meilulln.  il)-#pDiri 
thoracic  rpepirntory  move  men  Is  nn<I  convulsious  do  Dot  follow  upon  exclu 
of  air.  They  are,  however,  dated  tu  occur  in  newborn  oniniali),  indicalini 
that  Uie  subdidiary  niechaDHms  in  ibe  u[>|)er  epinal  cord,  of  which  we  enok 
iu  ^  ^Gi,  may  be  aiai)  affected  by  the  too  venous  bloud :  but  ihe  doubu  wliicl 
w«  previously  urged  hold  good  in  these  cases  also. 

While  the  rtepiratory  centre  Is  ihui  being  atTected  by  th«  urn  veoom  blood  , 
it  ii>,  until  exIiHii'tion  begiuv^  Iu  aet  in,  more  irritable,  mure  eiuily  iiud  lar|[el>r 
aflt-cled  by  ulfL'ri'tii  impulses  llmu  iti  iu  nurnial  i-»iiililii>H.     Diirinu;  dyspniB^ 
a  KtiinuliiB  which  applied  l<)  the  va(r|iM  or  in  mime  nlher  »uii<<,>ry  iiervt;  tiuder 
nurmnl  i^oiiililiiiiiH  would  produce  littl«  or  no  edlict,  may  stitrl  very  ffuvitrfaj 

^373.  bi-lici<rut  lu-rntioii  produces  tivn  effects  in  blood :  it  dimiui«he4  iht 
oxvg^in  and  ini-r<.iu>L-ii  the  carlnmic  add.  Do  both  of  lht«e  changed  aSwt 
the  rr:<[>iruli>ry  ct*4ilr6,  or  oulv  one,  Bud  if  si>,  which  '!  When  nn  animal  is 
made  to  brcntho  an  atmiMplierc  contiiiiiing  uilmgeu  only,  the  ozil  of  aw 
bonic  acid  by  diflugioii  w  tint  alTcctv<],  and  the  blood,  ns  is  pn)v«l  by  actnal 
Bna1yai»,  contiiiiiTi  no  cxctv*  of  carbonic  arid.  Yet  all  the  phenomeDa  of 
dyspncea  an:  prcwut,  and  if  tho  cxporimcnt  be  cuntiDiied,  conTuUiooa  cnroe 
and  the  animnl  dies  in  asphyxia.  In  this  case  the  result  can  only  be 
attributed  to  Ihe  deficiency  of  osyKcn.  Ou  the  other  hand,  if  an  animal  be 
made  to  breathe  un  atmosphere  rich  in  carbonic  acid,  but  at  the  same  time 
containing  abundance  of  oxygeu,  though  the  hreatbiii^  becaraw  markedly 
deofier  and  aUii  mimenhai  umre  fre'|ueul,  there  is  no  culmination  iu  a  eon> 
Tulsive  asphyxia,  eveii  when  the  quantity  iif  carbonic  acid  in  the  htood.  n 
ahuwn  by  ilirocl  analyvia,  is  very  largely  iiicruased.  Ou  the  ciMilrary.  t)>e 
incmuM;  iii  the  rvspiratory  moverrii-iiU  may  alV'r  a  while  pum  off,  the  iinimal 
becoming  uncoiiKcioiis.  and  appt^ariiig  to  he  vulfcriug  rather  from  n  narcotic 
poison  than  from  Mmpic  dynpniiii ;  llie  ■■xci.^iw  of  carbonic  acid  in  the  blooil 
appears  to  afltict  other  parls  iif  the  wnlnil  nervous  i>ysteiti,  and  ojH-cially 

forlions  of  the  i>rain,  more  pro^iundly  than  it  does  the  reypiralory  cenirc, 
t  has  been  muintatncd  by  K>nie  that  while  a  delidcncy  of  oxygen  pr()mot«> 
inspiratory  movements,  an  cioon  of  carbonic  acid  »timulHtr«  Ihe  expiratory 
movements,  ihe  nervous  madianismg  being  so  arranged  that  a  lack  of  oxygen 
leaits  to  an  eflbrt  to  get  mora  of  it,  and  a  too  great  load  of  carbonic  acid  to 
au  elfurt  to  get  rid  of  it ;  but  the  facts  are  opjiuseil  to  the  eiisUmoo  of  any 
■ucb  teleolo^cal  aduptntiun.  It  is  obvious,  however,  that  a  lack  of  nxygeo 
and  an  excess  of  carbonic  acid  uSeci  the  iespirat»r>'  centre  in  rery  different 
ways,  and  that  in  ordinary  cases  of  interference  with  tlie  inlerclianKO  in  the 
lungs,  as  in  deficient  ai-ration,  it  is  the  lack  of  oxygen  which  jnaya  the 
prim-ijiiil  part  in  developing  the  abnormal  nupirutury  uuventeuta.  We 
inay  infer  ihat  it  too  is  chielly  voncerueil  in  n-gulaiing  the  more  normal 
nepirution,  hut  cannot  as  yet  say  what  !•  the  exact  .iharc  to  be  attrihutis)  to 
the  earbonic  acid. 

AVe  may  here  (xiint  out  that  it  is  n»l  (o  bo  suppomd  that  each  brcatit  it 
detennincl  by  the  condili'in  of  tho  blood  flowing  through  th(<  cnpillnric^  of 
tite  medulla  at  the  moment  |)rocedilig  that  lirenth,  il  i«  not  to  be  imagiusd 


Tns    NKRTOt'S   MBCnAXISM    0>'    RESPIRATION*.  4S9 

titat  eacli  breath  u  tbe  result  of  t)i«  lack  uf  nxy^n  felt  i  in  mediately  before. 
Od  th«  iMtilrary,  ta  we  have  |ir«rio(iHl_v  ur^j,  the  rwpirntoTT,'  rnitie,  like 
tUtb  rjirdiao  Milwlnim.  U  nii  auloinatio  i;e»tre,  i)i«  respiratorr  i(ii|>i]UeA  Uaue 
fVoni  it  in  rbylhnii<r  wnM  sjt  n  rftiiill  of  tlui  nxilcoular  cliiinK;«a  of  (he 
inetaboliani  going  mi  iii  il«  niiKhIikkv  ;  an^  whiitrvi-r  atlH'tK  lliat  rli.vihiii, 
L  w)i«ther  feir  or  miwy  b«*t«  be  iiifliii'iioHl,  proiluora  iu  tiMull  liy  mi>rlitViiig 
I  that  meUboluiin.  A  lack  of  oxyi^'n  in  itir  blood,  or  n  iKrrvuiin  imixiliti 
along  un  nt)(in'iit  fibrv,  Ixilli  nAVct  ibv  (^'nlri.'  by  nimlifyiiif;  its  ludabofiMn  : 
Imt  I'luh  probably  aflVcts  it  in  a  liiffcrrnt  way.  It  i^  bfyond  our  preMnt 
kiiowWgv  lo  explain  how  either  the  one  ur  the  other  mrt*.  Wc  may  imagine 
that  a  lacl:  of  oxygen  on  the  other  hand  hat  a  morv  prolbiind  utli-ct  in  modi- 
fying the  wholi?  oom]>lvx  eerie*  of  metabolic  cbuigcs.  tb«  whole  chain  of 
building  tip  and  breaking  doirn  prooesws,  thus  in  Bonie  war  or  otbi-r  rrn- 
dering  the  whole  edifice,  m  tu  spmk,  more  unstable  :  mid  llial  an  attcrent 

InugniCDting  impulse  (and  poa&iuly  an  excess  of  carbonic  acid)  acts  nilh«'r 
nnvr  the  niehion  of  what  we  are  accustomed  to  call  a  slimutiie,  and  tires  otf 
n  lormr  amount  of  the  already  stored  up  explosive  ixmipounds.  And  wo 
may  further  imagine  that  the  spectat  feature  of  llie  substance  of  the  respira- 
tory centre  is  that  its  metabolidin  is  eo  wranged  na  to  be  thus,  unlike  that  of 
other  livioK  suhslanoes,  rendered  unstable  and  more  explosive,  not  siniplv 
diininisheil  or  deadened  by  a  laek  of  oxygen.  But  tbeee  as  yet  are  matters 
of  specutiition. 

»We  iDKyf  lierhape,  add  that,  under  i,-arious  nutritive  eoudilions.  tbe  seu#i- 
tireoen  of  toe  metabolism  of  tlie  reapiratory  centre  to  lack  uf  nxygeu  ma^ 
vary  niilely.  Thus,  while  undouhledly  under  tbu  normal  niitrilire  condi- 
tions aflorded  by  the  ordinary  su]>|ilr  of  ixirnial  blood  l<>  the  medulla,  laok 
L  of  oxygen  in  that  liliHtd  at  onoe  pnivoktv  inrreiued  rMpiniuirv  niovenienta, 
f  it  oee^  not  do  s^i  nmkr  ntlwr  nutritive  condilionsof  ihe  medulla.  By  trans- 
ftision  a  large  pr>i|Hirtion  of  ihi-  liaHnoglobin  holding  blood  may  in  an  animal 
l>e  gradually  rt'plaenl  by  liiemogiobinTcMs  iiorniid  #al{aeaolutton.  hi  ^urli  a 
oaae  the  amounl  of  oxvRn  brought  to  tbe  meiliilla  by  the  diluteil  blood 
muM  be  greatly  diminished,  a»<t  yet  if  ihv  eliange  Iw  made  suiriciintly 
slowly,  no  00fiMHrtiou.->  dvHpno-a  in  jircHlticetl ;  tinder  llie  new  vtrange  nuuitive 

Icofuirtioiu  of  the  diltiUiil  bknid  the  niedulU  is  not  iifll'clcd  in  the  same  way 
U  Iwfinv  br  lack  of  oxygen. 
i  374.  I'herc  are  reasons  for  thinking  that  conditions  of  the  blood,  other 
than  variations  in  ihc  amount  of  oxygcii  aitd  carbonic  ncid.  niuy  niao  nMtt»> 
rtally  iitfect  the  vorking  of  the  respiratory  centre.  It  is  a  matter  of  common 
exjirrivooe  that  mtiwrular  exertion,  especially  if  at  all  exoes*ive,  incrvosH 
tho  rcMHnitory  movements ;  violent  exercise  soon  puis  a  man  "  out  of 
breath.'  This  incrrasod  activity  of  the  reepiratory  r<cntr«  is  in  large  inoiisnr« 
at  all  events  cauted  bv  the  character  of  the  blood,  which  during;;  and  for 
some  liule  time  atU>r  tlie  movements  is  curried  to  tbe  medulla,  and  not  by 
any  iierviius  impulH>eti  «ent  up  to  tbe  medulla  from  (be  contracting  muscles. 
This  i«  j^iown  by  [be  fact  ttial  if  iu  an  animal  tbe  spinal  <-nrd  be  divided  in 
tbe  dorsal  »r  lumbnr  region  and  the  bind  limbs  be  powerfully  tetanized,  tbe 
resniratory  niuveinents  are  increased ;  the  animal  pants  as  it  would  do  if  it 
hail  l>cen  runuin;;.  In  such  a  case  the  only  connection  lielwet^n  the  bind 
linibe  and  the  rwpiratory  centre  ia  through  tbe  blu«<l:  it  muHt  be  some 
diauRe  in  the  blood  caused  by  the  muscular  couiractiitns  which  affects  tbe 
medulla  when  the  blood  noaaea  from  the  hind  limbs  to  Ite  dbitributei  by  Ihe 
beort  to  tbe  medulla.  Vow  when  a  mibwle  ooulrocts  ito  on.tumplion  of 
oxygen  and  produeiion  of  carbonic  atiid,  especially  tbe  latter  i^  t>:t},  are  in- 
creased ;  the  bhnid  Iniviiig  tbe  muscle  is  more  vtmous  than  usual.  Hence, 
when  ntany  niiisdca  are  contracting  powerfully,  the  liloml  carrier!  lo  the 


m     wiivu    ouiny 


^ 


riglit  "ill""  onn^niSin  in  more  vrmiun  tlini)  iiftiiiil :  nivil  wr  nit^t  ^xpM^lfiiiT 
it  w  this  iiniisiinllf  vrirnus  blmMl  fuiliiig  v>  bo  ncliijiiJiU-ly  ariprUIi/j-H  in  th» 
lungH.  amt  Iipik-c  rFsching  llif  nuilnlla  fmni  ihr  left  side  of  ihti  ln-arl  in 
more  vrtiniie,  Utn  oniDplctply  iirtcrinllicl  oimilition  thnii  luiinl,  tvliich  «lir» 
Mp  tlie  reapirntorv  oenm-  lo  incrcnwi  nclivity. 

On  exnniiiiatiati.  however,  it  is  f'oiiii'l  ihnt  the  blood  Icariof;  tli»  left  Md(» 
of  ihe   lienrt   in  •■iicli   «ih:«  ii>  nol   lc«s  itrtcriniized.  but,  if  Hnytbing.  niof^b 
arterinliwd  ihan  usual.     The  iticrrastsl  respiratory  movemenla  indiicvd  bi^ 
(he  chani^d  blood  soon  prove  sufficient,  or  even  nior«  ihnu  sufficient,  to  givo 
the  blood  ttie  extra  qiinntity  of  oxvf^n  and  to  remove  tlie  extra  qiuniiiy  of 
cnrbonie  acid.     Obviously  the  blood  coming  from  the  (etaniKe<)    muscles 
tifects  the  rear^iraiury  centre  by  virtue  of  some  (luality  which,  unlike  tbu 
flue  to  the  deficteufry  of  oxyti^n  or  exeeas  of  carbonic  acid,  is  not   initne- 
dialely  nflected  by  the  jtatHafce  through  llie  lun)(s,     Wliellier  the  ijualitr  ii 
(|uciiti»ii  be  dep^<t<^Dt  on  tiu  exceea  of  enrolactic  and.  or  on  borm  other 
ptnduut  or  product!  of  nitiacular  luetabolism,  we  do  tuA  u»  y«l  know.     But 
the  fai-t  that  nubtUwce*  in  ibe  blood  may  An  alFoRt  the  m>|iim1ory  centre  'u 
Inlen^tirig,  nincr  it  fihow*  by  how  inauy  wufegiiardit  the  working  of  the  re- 
•piralory  centre  iii  carefully  adnpUs)  l<>  ihc  nredit  of  the  economy. 

ThuK  a  elian^F  in  llu^  ciriHinintaneei'  mirrounding  an  animal  InHly.nra 
cIiHnj.'r  in  tliv  bodv  itmrlf,  iniiy  in  one  or  nion-  of  wivprni  wavK.  bv  nrting  m 
n  ti^imuUio  to  ininiit  artcrint  nerve*  and  no  K-ndin^  up  alTen-iit  m-rvoua  fm- 
pnlRcs  to  the  respiratory  centre,  or  by  interfering  with  the  interchnng*  of 
Knt»  in  the  liinp',  or  by  otberwinc  altrrinR  the-  proportion  of  the  givc:>  prewnt 
in  the  blood  reaching  the  re»iiinit'>n,-  ecnirc.  or  by  generntitip  or  incrntwing 
in  that  blood  some  snbstnnec  or  substances  tending  lo  aflcct  the  nutrition  of 
the  respiratory  centre,  affect  the  working  of  the  all  important  breathing 
tncchaDism.  And  the  alfcction  »<>  wrought  ha>>  generally  an  adaptalivp  char- 
acter;  it  generally  teuds  to  protect  the  organism  against  the  evil  ededaof  tlie 
change. 

$  376.  Apwra.  When  ire  attempt  to  hold  our  breath,  we  find  that  ire  can 
do  thin  for  a  limited  time  iiiily  ;  tooner  or  later  a  brcHth  miiu  come;  but,  as 
it  well  known,  the  linif  iliirin^  whleh  we  can  remain  without  breathing  may 
on  occasion  t>e  niticb  prolonged,  if  we  finil  of  all  take  a  iN-rie«  of  c  eep  breaib«L 
It  in  probable,  though  perhuju  not  ilintinctly  proved,  that  when  we  breathe 
Voliintarily,  or  irlicn  by  nti  act  of  the  will  wo.  hold  the  mtpiratorv  apparatni 
in  any  one  respiratorv  phm»e,  the  nervoii*  impiilmii,  gt-nersted  by  the  will, 
do  tioi  pass  down  by  a  direct  and  independent  roiiwe  to  the  re^niratorv  mua- 
cles,  but  that  tlie  will  makes  n»e  or  niodilies  the  nctiviiy  of  the  medullary 
and  fpiiial  nervous  respiratory  mech«iii*ms.  The  brcnth  tmoner  or  later 
inevitably  follows  because  at  la»t  the  natiinil  impulse*  proceeding  from  the 
respiratorv  centre  become  too  imperious  to  be  any  longer  held  in  check  by 
tlie  imputsei^  of  volition  pai^sing  down  to  the  centre  from  tli«  brain.  The 
fact  that  a  series  of  deep  breaths,  n  thorough  ventilation  of  tlw  luncs  pnat- 
ponea  the  victory  of  the  unconscious  centre,  shows  that  inch  a  ventilation  in 
•one  way  delavs  the  development  of  the  natural  respiraton,-  impulses'.  A 
rimilar  but  sli^l  more  marked  delay  may  oReu  be  seen  in  an  animal  under 
artificial  respiration.  If  in  a  rabbit  artificial  respiration  is  carried  on  very 
vigonHisly  for  a  while,  and  then  suddenly  stopped,  the  animal  does  not  imme- 
diately lii-jfin  to  breathe.  For  a  variable  period  no  respiratory  movemenla 
nt  all  lake  plnce.  and  breathing  when  it  does  begin  occurs  gently  and  Dor- 
nially,  only  |<ni<t>int;  into  dyxpnu-a  if  the  nninial  u  unable  to  breathe  of  itself; 
and  even  then  the  iranniiton  in  (piiti?  gmdual.  Evidently  during  thin  period 
the  re»pirato(v  lentre  is  in  a  ataic  of  complete  rest,  no  exnlo»iuna  are  taking 
place,  ltd  rexpiratory  imputiN-di  are  being  generated,  and  tliC  quiet  tianvittun 


THE   NERVOUS    WECnANtSU    OP   RESPI  nATIUN*. 


-191 


I 

I 


I 
i 
I 


I 


from  tbu  condition  Ui  thut  iit'  Dornml  rrvpinili'in  »1k>w>i  ihiit  iliv  Mulivranvnt 
generation  »f  inti>iilA>ii  U  nttciitlcil  t>y  nn  gmit  (li»liirl>iin<N>.  Noc  au\y  ■■'•  the 
centru  Hi  KM,  Itut  it  ix  Inw  irntnhlv  thim  iW  Tionniil ;  iininilsoii  nloiig  the 
vugUK  or  (itlicr  ucrntu  wliich  olbvrviiw  wmilil  r>n)iliico  mtpiratnry  Axplixiioiis 
arp  now  im-fltTtiiiil.  Thi«  «atf  of  thingn  ii^  ktmwn  ii;"  ihnt  i>f  npn<ra.  the 
ooDverecof  tlymitKi-ft ;  iiml  thr  longer  pniU'C  in  hmitliing  incniionol  aHorc 
U  poMittk-  iifiVr  ii»ii6iiiil  vcntilntioii  of  llic  liing«  may  Ih-  rrgnnlvil  ii»  n  brief 
npnivii. 

Xtm-  it  Mvnied  nntiini)  to  tunpow  that  »tich  a  vUilo  »i  r«M  of  th«  rf«[>irii- 
ti>rv  centre  wiu>  bTt>ii);hl  nbrnit  W  the  more  thnn  necwsiirily  »nipl(^  Hi(i|>ly  of 
oxvgrn  atKirdci)  by  llie  ))revioii»  increased  in«]>imtory  n><>venirnt« ;  niKl, 
indeed,  it  Kas  Diaitilniiied  l)i«l  Bpn<»n  wna  th«  resnit  of  loo  great.  )iiBt  ns 
dy>)>uiTa  is  the  result  of  too  liltif  arterial iznl ion  of  the  blood  reaohing  the 
re><]>imt"ry  mitre.  It  was  argued  that  owing  to  the  increased  vigor  <if  the 
nrlilirial  refi|)irati>ry  niorentenlii  llie  haemoglobin  of  llie  arterial  bliKxl,  which 
in  Dornial  lirealtiiug  is  not  ijuite  saturated  nith  oxvgen.  heeame  almmt  eoni- 
pletety  BO,  and  thai  at  the  same  lime  the  ((iiantity  of  oxygen  dimply  dissolved 
in  the  blood  became  laigdv  incrvased  and  its  tension  largely  augmented. 
Unt  tliere  ar«  reasons  which  rt-wler  such  n  view  unienahle.     In  the  first 

Claoe  there  ia  no  direct  and  sntixfactory  proof  that  in  apnwa  the  arterial 
lood  ia  overloaded  with  oxyg«n  no  fiini nosed  ;  indeed,  during  the  course  of 
apncea  before  it  has  come  lo  iin  end  the  bl'md  t)econ>eit  distinctly  leas  arterial, 
inofe  venoiit  than  usual.  In  ihf  second  place  ii[ino>«  if  not  entirely  impossi- 
ble, is  much  nion?  dtHietilt  lo  bring  nlMHit  irben  both  viigus  ncrv«s  are  divide<l. 
aixl  if  it  d<ieH  ort-ur  after  Hcclioii  of  the  vagus  ncrvcK  hiu>  not  the  same  char- 
acien  a*  onlimiry  H|>ii(i'n.  Now,  when  nrlificial  revpinition  is  Wtn^  carried 
on  aection  of  the  vagus  m-rvi*  can  have  no  cffi-rt  '<n  ihc  i]iiantily  of  oiygun 
taken  i>|>  by  tlie  blood  in  the  lung*.  Out  ihr  vagu*  ucrvt*  are  the  diaiinvl 
of  impulse*  aftwtiiig  (be  renpiriiiory  centre,  iin>l  thi«  relation  «if  the  apunOR 
ta  tJM)  vngus  nerves  »iigg(«t'  another  and  diflcn-nt  i»ter|ireliition  of  apn<r«. 
lAs  *ni  bare  •«»,  eximnKion  of  the  lung  by  acting  in  »>me  way  or  other  on 
It*  pnlmMMrr  terminations  of  the  vagus  nerve  sends  up  along  that  nervi? 
impulse*  which  inhibit  inspiration.  And  it  is  nrgiitd  that  re|iciiled  forcibk 
inflations  of  (he  lungs  pi«duce  apDoea  bv  generating  poteni  inhibitory  im- 
pulses, which  by  a  kind  of  summation  of  tlieir  elfecis  in  the  medulla  slop  for 
a  whila  the  generation  of  respiratory  impulses  in  the  respiratory  crntra. 
This  conclusion,  moreover,  ia  strongly  supported  by  the  fact  that  uu  apnom 
may  be  {Hwluced.  so  long  im  the  vagus  nerves  are  intact,  by  forcible  arlifictsl 
respiration  with  hydrogen  instead  of  almoeplieric  air;  in  other  words,  the 
inl^ibiiory  impuldea  generated  in  the  vagus  nen'««  by  the  inflation  are  sufti- 
cieni  wholly  to  neulrnliKe  tbe  development  of  reapirator^'  impulses  which  the 
deticieni  arterial iut ion  of  the  blood  would  otherwise  have  produced.  Tbe 
exact  nature  and  development  of  such  a  summation  of  inhibitory  impuUes, 
eapecialty  in  tbe  pre»enoc  uf  correlative  atigmentaiivi?  impulses  called  forth 
by  tbe  currtviiunding  aueceMiiTe  <-olla|]eii=i  of  ihf  lutigs,  ia  loo  complex  a 
matter  to  Ifc  itwcit  <in  hen-.  Moreover,  an  a]>nie<a  may  b«  produced  inuugh, 
as  we  have  ratd,  with  ditfimllT  Bl>er  section  of  both  vagus  nerv'<«;  but  in 
thi»  case  air  nnd  not  hydrogen  niu>t  be  nseil  fur  inltation,  the  nae  of  the 
latter,  in  c<inlm»t  to  ihc  n,-*ull  when  lh<'  iiervi-H  are  inlai.-t.  leading  to  dya- 
pnuea.  The  subjeet  eauiiot  il<  vet  he  eoRsiderc<l  lu  fully  cleared  up.  That 
apnu-n  as  ordinarily  pnxtuced  n  in  »ome  way  the  rmult  of  inhibitory  impulsea 
genenii'sl  by  the  iuHalioiw  enn  how-ever  hnnlly  l>«  doubti-<t. 

5  378.  Srfouilitiy  Tf'ii'ralory  rtiylUm — Vhrynr-Sf'tkr*  rr*pitnH»H.  A  re- 
markable abnormal  rhythm  of  respiration,  liret  ohservei)  bv  Cbeyne  but  after- 
ward moTV  ttlllv  studied  bv  tStoKee,  nn<l   hence  calkt)  (iv  their  combined 


482 

DKuw*.  cic^-iirx  ii>  cvrtniit  |i«lho)o|;ical  ca'^8.  Th«  T^pir^tory  monraMtll 
^uluall/  ilwresM  both  in  extent  and  ra|ii(liiy  until  thev  oeaae  alUigMlHr, 
tod  »  conililioii  or  apiMoa.  laatiof;  it  mar  be  for  Mveral  loconda,  enmMi 
Thb  it  fulltiiTcd  by  a  leeble  respiration,  succeeded  in  turn  bv  a  sometrbNl 
nirnii^-r  one,  and  thus  tbe  raepiratiou  returu^  ^'raduHlly  to  the  iiortiial.  or 
may  iivro  rise  to  hyperj>u<ea  or  slijtlit  dys|imea.  after  which  it  agnia  ditK-lim 
ill  It  itintiliir  niaiin«r.  A  secondary  rhyltiin  of  respiration  i^  thus  ileveloned. 
[wriods  of  iionual  or  stisbl  dytt]tii<i:i«  reepirulioa  alternalinK  l>y  gradual 
Iraneitioiu  witb  perioiU  of  apuoea.  The  cause  of  the  phenomena  is  not  tJior- 
oiighly  undertoiid.  Whellier  llie  waninji  and  waxiu^  of  tiie  respiratory 
movements  be  due  lu  cwrnrspiimlii));  rhylbmio  chanj^  iu  the  nuirition  of  the 
respiratory  centre  it«elf,  or  in  a  rhythmic  iticrawe  and  decrease  of  inhibitory 
impulses  playing  upou  that  c«nir«!  from  otiier  )iiarU  of  the  body,  for  instance 
from  hi)(er  i-egiona  of  brain,  hii-i  not  yet  bi^fii  iwtllcd.  it  fre()U{^ntIy  a|>pe«T9 
iu  oonuection  nilh  n  fatty  cimdilinn  of  the  Ix-art,  hut  has  b^u  met  uilh  in 
rarious  mnliulln*.  Clowly  Mniilnr  |>hciiom<-n«  have  been  ubaerrcd  durioK 
aleep,  un<lerj>erfe<-i!y  nortnal  coii<Iiiion« ;  and  thL->  fairt  »  rather  in  &v»r  cif 
Uie  latter  of  the  !«<>  rxphuiiitioiis  jiMt  Kiven.  Tbc  phenomena  prem^nl  a 
Mriking  analogy  with  the  "  groups  "  of  hearl-lxmtM  wi  fn^uently  weru  !ti  tin 
ftox'a  veutncle  placed  under  abnormal  circnmnlMiooa. 


Tub  KpFBore  or  CiiAM(it»  ik  tiik  CoMroHrriox  axd  Fbbhubi 

OF  TIIK   AlH    ItltKATllKD. 

S  3T7.  The  preceding  aections  have  shown  ns  tliat  the  renpirntory  mechan- 
km  is  arrunged  to  work  satisfactorily  when  lh<r  King*  ar«  advquaUiIy  NUppliad 
uilb  air  of  the  ordinary  comjiwilioii  of,  and  at  the  ordinary  praasure  of,  tin 
atmosphere.  We  have  further  seen  that  tiw  mecliaTiiKni  can  adapt  itself 
within  certain  limits  to  chaugOH  iu  the  oompoaition  and  prrmuro  oflhe  air 
supplied.  Wo  marnow  consider  briefly  what  takes  place  when  ihoM  limiu 
are  overstepjXMl.  The  most  atrikin;;  elfects  are  seen,  wheJi,  on  account  of 
oocluuon  ot  the  ireacliea.  or  by  breslhin^  in  a  confined  space,  or  for  other 
nwoas,  a  due  fiu|>ply  of  air  not  betng  obtained,  normal  respimtion  givea 
place.  thn>u)-h  an  intennedialA  phase  of  dyspmea.  lo  the  condition  known  u 
as[thyxiii ;  ihi»,  unleaa  remedial  measurea  be  taken,  rapidly  proves  fatal. 

Atphifria.  Aa  soon  as  the  blood  beoomea  leas  arterial,  more  venoua  than 
norma).  tlM  reapiratory  moreinenta  hbcome' deeper  and  at  ibe  same  lime  more 
fmiucnt ;  both  the  iii^pinilory  and  espimtory  phasea  are  exaggeraled,  the 
supplementary  miiMle?  »|>oke»  of,  $  .t-^.  are  brought  Enio  play,  and  the  rale 
of  tbe  rbyihm  b  biirriol.  Th4v«  effecu,  as  m  liarc  aecdi,  are  chiefly  to  be 
Bseribeil  to  tbe  deficiency  of  osygttii  in  the  blood. 

As  llie  blood  contiimcii  to  become  more  and  moiv  venous  tbe  rcspinilury 
movemoils  continue  to  incrtawe  both  it)  fonw  and  fnyjuenn-.  a  larger  number 
of  miisclAi  iH'ing  cullixt  int4)  airlioit  and  that  to  an  inorviuiug  extent.  Vcrj 
siKid,  however,  it  may  be  obserwd  ihat  llie  cxpinttorv  mnvi'mcntM  are  Iwcom* 
tng  m<iri;  niarkcxi  tluin  the  inipiratorv.  Every  mUHcle  nhich  can  in  any  way 
aatiitt  in  oxpirtilion  >*  in  turn  brought  into  play  ;  and  at  taal  almont  alt  tlie  mufr 
ol(H  of  the  Wiy  lire  involviil  in  the  Mrngglr.  Tbe  orderly  expiratory-  mov*- 
ntcnU  culminutc  in  expiratory  roiivuUioiii',  the  order  and  in-|ueiice  of  which 
are  obsctirol  by  their  violence  and  cKlenl.  That  ihcMe  coiu-uUionn,  through 
vhich  dy!piia<a  merges  into  asphyxia,  are  due  to  a  slimuhitioD  (by  tbe  venous 
blood )  of  t  he  medulla  oblongata,  is  proved  by  the  fact  that  they  fail  to  inakt 
their  Bi)|)earanee  nhen  the  spinal  con)  hio'  Ix-en  pfwiously  (lividid  Mow  the 
medulla,  though  tbey  still  occur  after  those  jxirtiona  of  ine  bruin  which  li« 


iibuvc  the  ni«Itillit  htiTc  Im-ch  rcni'ivdl.  It '»  Uftiml  to  «|>rHk  of  n  "convul- 
Bive  centre"  in  th(>  mcdulln.  the  stiniiilntiuii  of  which  givee  riec  to  these 
CORviilsioDB  ;  hut  if  wo  acoep;  the  existvnw  uf  euch  »  centre  wo  niuflt  at  lh« 
MUDe  time  admit  that  it  is  connected  br  the  cloNWt  1if«  with  the  nnrmn) 
expiratorT  diviaiun  of  the  reepiratory  centre,  tiaix  every  intervening  step 
may  l>e  ooserved  belwecu  a  simple  sHf^ht  expiratory  moveiuent  of  normal 
respiration  and  the  most  violent  codvuIhou  of  asphyxia.  Ao  addiiiDiial 
p^Klf  that  these  convuUions  are  carried  out  by  the  uj^ottcy  of  ibe  medulla  is 
■tfurded  by  the  fact  that  convulsions  of  a  vrhoUy  similar  cliaracler  are  wit- 
ueti8«d  when  the  supply  of  blood  to  the  medulla  is  suddenly  cut  itfl*  by  lij^a- 
turing  the  bloudves^ls  of  the  bead.  In  this  case  the  nen'ous  ceulre«,  keiue 
DO  lnnK*^r  furiiishe<l  uiih  tn^h  blood,  become  rapidly  asphyxiated  through 
lack  ul  iixy^eu,  and  cxpiratorv  coo vulsioos  quite  niniiar  to  tliose  nf  ontinai^ 
lUphyxia,  and  precedea  like  iKem  by  a  pawing  pbaae  of  drapnixa,  make  their 
Hppearauce.  Similar  "aiitenaic"  convulBtana  are  seen  aher  a  sudden  and 
iiuffi  low  of  blood  ttom  the  body  ut  large,  the  meduitu  hriii};  ximilarly  stimu- 
lated by  the  Uwk  of  arterial  blntHl.  In  ordinary  fuintiti);.  whidi  ia  Iam  of 
COD»oiouiDen>  due  to  an  inHuffimnl  supiily  of  blouil  to  tliv  brain,  the  dlminii- 
Uou  of  blood-nupply  in  not  ^rr^t  eDougli  to  priHlucn  tlM»«  ■■i>nvnIaionK. 

t^uch  violent  «tiiirt>  Hgiecdily  exliaunt  th«  nrrvouN  *v#k-ni ;  ami  thir  convul- 
■iuna  after  being  maiiitainttl  f(ir  a  lirinf  jwriod  Dudncnly  t-eaK*  and  aiv  fol- 
lowed by  u  [wriiid  of  cJilni.  The  oalm  i*  ope  of  exhaunlinn  ;  tlic  pupilit, 
dilated  to  the  utmost,  arv  unafltnitet)  by  light;  touching  the  cornea  cuIIh 
forth  DO  movemvut  of  the  cvclido,  and,  indeed,  n«  rvflex  actions  can  any 
whcTp  be  produced  by  tbc  Mimulalion  of  i>ciiticnl  ituriaw*.  All  expiratory 
active  rouvciuMita  bare  ouued ;  the  miwcUv  of  ihc  body  are  flaccid  and 
quiM :  and  though  from  time  to  timv  tbe  respinUury  centre  galhcn  enHii-teiit 
energy  to  develop  n-Hpiratorr  niovementa,  these  raemble  tboM  of  ijuiel 
aonBal  brcalhiu);,  in  l>eing.  as  far  as  muscular  nctioni!  are  concerned,  almost 
Mitirdy  itiKpintiory.  They  occur  at  long  interval*,  like  thoff«-  nlUr  ecction 
of  the  vagi :  and  like  them  are  deep  and  slow.  The  exhniistcd  r<i>piratory 
MOtre  tnkee  som«  time  to  develop  an  iiupirntory  explmion  ;  but  thi-   im- 

' «  when  it  is  generated  is  proportionately  strong.    It  teems  as  if  the 
itance  which  hod  in  each  case  to  be  overcome  was  coosiderable,  and  the 
effoit  in  oon«equcnee.  when  »ucce»efut,  productive  of  a  large  oHbd. 

Very  suod,  thwe  inspimlory  etTorts  become  tees  frequent ;  tbeir  rhythm 
beoomee  irnsular ;  long  pauses,  each  on«  of  which  seema  a  final  one,  are 
oucoeeded  by  several  somewhat  rapidly  repeated  inspirations.  The  pauses 
beoone  longer,  and  tJie  inspiratory  movenenta  eballower.  Kach  inspiration 
la  aeeomiwuied  bv  the  oonuacliou  of  aceeosory  muscles,  eapecialty  of  tbe 
face,  so  tnat  each  breath  beoomea  more  and  mure  a  prolonged  gauk  The  in- 
spiratory gaspe  spread  into  a  convuliiivc  stretching  of  the  whole  oody :  and 
with  extended  limbs,  and  a  straiKhlened  trunk,  with  the  head  thrown  back, 
tbe  nwKilh  widely  open,  the  face  drawn,  and  tbe  nostrils  dilated,  the  last 
breath  t6  taken  in. 

Thus  we  are  able  to  dixlinguiiih  ttiree  stages  in  tlie  phenomena  which 
rtMill  firom  u  continued  detirieiicv  of  air :  1.  A  stage  of  dyspniva,  churac- 
t«riud  by  an  incrMwe  of  the  re»|>iraiory  movemeala  botJi  of  iuspiraliou  nuil 
expiration.     '2.  A  convulnive  Kaj^,  chaiacterixed  by  the  dumiuanct-  of  the 

E~"  iratory  effurl.i,  iind  culminating  in  general  convulsions.  3.  .\  >tage  of 
aui<ti<in,  in  which  lingering  and  loug-dnivu  iibpi  rat  ions  graduatty  die 
out.  Whrn  bp>ught  alMxil  by  sudden  occlusion  of  the  irat-bca  tiuae  evNila 
run  through  Ihvir  raurse  in  about  Rmt  or  five  miniitm  in  the  dog,  and  in 
about  three  or  four  minuua  in  the  rabbit.  Tlie  tin-t  stage  pannui  grmlually 
into  iba  scoond,  convulsions  appearing  at  the  end  of  (be  lint  minute.     The 


404 


• 


iriuuitioD  tmm  tlw  Ncond  tinge  to  the  tliiril  is  eomcwluit  kbnipt,  the  mn 
viiliioDfl  tiuddfinly  oeasiDK  early  iu  the  see»u(]  iniouie.     The  roaMOiiii;  tini« 
is  uccu|>Kil  in  ihv  iliinl  stage. 

The  iluruiiiiu  uf  ud|)tiyxia  varifi)  not  ouly  in  <lifler«iit  auiinals  but  in  t 
mmo  animul  umter  ililfvretil  oimumMaiieeB.  Newly  b>jrn  mid  iroung  itninui' 
□OmI  much  longur  immcniuii  in  WKt«r  l>efi)rc  deatli  by  aapliyxia  occurs  thi 
tla  adulU.  Tliu.t  wliil*  in  n  rull-grnirn  dii^  recovery  from  drowning  h  u 
lUual  nlW  OIK.'  und  n  lialf  niiiiulMi,  m  iiewbitni  pufipy  has  l>eea  knowu 
boar  an  inini«n<i(>u  nf  tt*  muHi  m  61\y  miiiulm.  Tbe  cause  of  tl>e  dilfereD< 
lita  in  tjic  tuvt  that  in  iliv  i]iiiu^  yuung  or  r«clier  jiut  bora  aoinial  ihe  rwjN" 
nUiry  clmngt*  of  tlw  tiwiiw  am  muclk  luw  active.  These  oonaume  Ie« 
oxyeni,  and  tlic  fnosral  Rturv  of  oxygen  in  tln^  bloml  haa  a  leas  rapid  demand 
oiaiu:  u|H>ii  iu  'uiiB  raapimtorr  activity  of  tho  ttnuen  may  aim  be  Ictnened 
by  a  <kfici«ncy  in  the  circulation ;  hvnm  bmliw  in  a  Aat«  of  ayuoujie  at  the 
time  wken  ibc  dvprivalion  of  oxygen  begins  can  endure  ihir  liaa  fur  a  much 
kxigcr  period  than  can  bodies  in  which  tlie  circulaliiHi  is  in  full  Mwiiig. 
There  being  the  aame  store  of  oxygen  in  the  blood  in  each  caMc,  tho  quicker 
oirculalion  must  of  neeeaaty  bring  about  the  apoolirr  exhauiitiiin  uf  tti« 
otore.  80  alao  aiuBsthetias  may  diminish  the  etTooU  and  ilvlar  thi-  final  m- 
aults ;  Urge  doaea  of  anaalbietics  may  iirvvcni  tho  exag:^rniv'l  and  (ronvul- 
nve  movements  In  many  caaes  of  dronning,  d««h  is  biirtcnei)  by  tiie 
entrance  of  water  into  the  lungs. 

By  traioiaji;,  tbe  reepiratory  centre  may  be  accustomed  to  bear  n  scant; 
aupply  of  oxygeu  for  a  much  longer  time  than  UMial  before  dyspnoea  Mts  J. 
a»  ia  Been  in  ibe  case  of  div«r«. 

Th«  phenomena  of  alow  naphyxia,  where  the  supply  of  air  is  gradual! 
diiutni»ned,  are  fuodaraentally  the  Mwe  u»  those  resulting  from  a  6udd< 
and  total  deprivation.     The  annie  stagei  are  Mien,  but  their  developine 
taken  plaoea  more  slowly. 

§370.  DeRdency  of  air  ratultA  not  oiilr  i»  a  diminution  of  the  oxy^ 
but  also  in  lui  increase  of  the  carb»iii<-  acid  of  the  hlood.     We  haro  seei 
however  (§.17.1),  that  ibo  phenomena  of  aMpliyxia  are  in  tbe  main  due 
tbe  former,  and  that  the  accumulation  of  uaVbonic  acid  io  the  blood  has 
subsidary  efli.>cu  only. 

If  the  pvrocnuge  of  oxygen  in  the  inspired  air  ha  increased  instead  of 
diminislifio,  tho  total  prasure  of  tbe  almosplM'rv  reniamitig  the  same,  the 
partial  prtasure  of  the  oxygen  alone  beiug  chiiMgi.fl,  »•>  marked  results 
follow.  We  have  alrrady  seen  (S  85S)  that  the  pcrovniage  of  oxyjien  in  llii 
ordinary  atmospbrrc  Iciivph  a  widi-  nmrL'in  of  oafely.  and  that  ({)  HT.*))  thi 
phenomena  of  apnoui  are  in  the  main  at  leasl  to  Ite  explaincti  as  thr  rwu' 
not  of  an  increase  in  the  oxygen  of  the  blood  but  of  nervous  intpiilw^ 
aioendiiig  the  vagus  nerves.  We  have  no  satisfactory  evidence  tluit,  pro*. 
vided  the  respiratory  mechanism  is  in  good  working  order,  an  increaM  of 
oxygen  in  ih«  inspired  air  even  to  a  whole  atmiiapbere  seriously  modifies  tbe 
respiratory  act ;  and  it  may  >»  doubted  whether  any  etl'ts;t  is  produced  eren 
when  the  mechanism  i»  impaired. 

$  379.  The  conij>u«iiii>ii  uf  the  atmoepbere,  tiie  pressure  remaining  the 
oame,  may  be  modi6ed  by  the  intnxluciion  of  fureign  itaaee.  To  some 
those  tbe  respiratory  mechanism  is  indifferent ;  for  ioaUuee,  hydnjgeu  raaj 
be  substituted  for  nitrogen  without  any  change  in  the  n^piration,  pmvidfN 
of  eouree  that  the  oxygen  ia  not  diininixhi^l.  Other  gases  may  produce 
poisonous  eSecls,  either  by  iaierleriiig  with  some  of  the  respiratory  proceuaca 
or  in  other  way^.  Thuit  carhun  tu<iiii>xide,  by  eombtniug  with  the  hiemo- 
glubin  of  the  rcsl  cirpii^rlfs.  and  in  preventing  the  corpOAcliv  from  acting 
a*  i>xygeu  carrient,  |>ru(ldC4-i  naphyxtn  through  deliciency  of  uxygeii.     SuU 


lIU 
ro.^ 


RrritCTS   t.tr    CIIAXOES    in    ATltUSPRKRtC    l-RKSSrnB.      499 


phurelted  hydrogen  inlcrr«rca  wtih  iii«  oxrgenBtiuii  uf  iht'  bliKii)  by  acting 
IIS  «  reduciug  ngvot.  .Soiii«  f^tMctt  uiiilc  nlloniiig  the  onJiiiary  rw|>iriiU)ry 
chaiigcB  of  Ihe  hlotid  ui  go  on  w  iiiiiiiil  jimdiieo  toxic  vfle<;U>  t>v  itk-tiii);  uu  <>ne 
or  otner  of  tii«  tis»ui«.  Thiw,  lu  »«?  have  »wii,  iin  exctw  oi  citrbonic  iici<l 
in  the  blood  taama  U>  hnve  n  Mirf-iiil  rffccl  on  the  ccotrnl  ucrvoua  system  und 
so  acl«  a»  a  oarcotlc  pi>is<>ii.  Tbo  pvculiar  utlocU  of  inlrous  oxide  (Uugliiiig 
Ras)  BK  kiiuiliiHv  due  1»  the  din-cl  acltim  of  the  gas  in  th<;  blood  on  the 
i-eutral  Dervous  syvtcin.  Sonw  gases  an  irrwpirnblc  and  iita)'  inlorforv  witii 
r«s|>initioii,  ev«R  cstisiii^  sufiocatioD.  on  acoonnt  of  ibcir  ciuisiiig  e]>a«ni  of 
the  glottis,  and  itiin  w  snid  to  be,  to  a  cenaiu  extent,  the  ciuc  with  an  atitios- 
ph«r«  whirb  i*  nitollj  or  largtly  compoeed  of  carbooic  acid. 

§  380,  The.  effetit  oJthange»  in  almMpkerie  /)m«>iirf.  DiminulioM  of  prt»- 
turf.  The  piirtial  prenura  of  the  oxygen  in  the  iaepiivd  air  may  be 
obanf^st,  Dot  only  by  altering  the  coinptMition  of  the  air  entering  at  the 
onjiiiary  alruoeplieric  pre8>ure,  but  also  by  altering  the  total  preasure  of  tlie 
atRMwpliere  nithout  dtangiiig  its  oomposilion.    The  rwulta  of  the  latter  are, 

»howev«r,  complicated :  we  liave  then  to  doal  not  merely  witli  the  efiecU  on 
the  intercbaoge  of  gases  in  the  luugsbut  with  the  elfects  on  the  whole  organ- 
urn.  All  (lie  coinpiioated  niacliiuery  of  ili«  tiudy  is  adajited  aiid  arranged 
to  Work  UDd«r  what  we  tiiay  call  onliuary  atimirplieric  pretnure,  that  lit  to 
my.  within  th«  limiUof  7liU  mm.  mercury  at  the  him  level  aiid  aliout  SOU 
■niu.,  cori«8|iondin{[  tn  an  altitude  of  <<000  feel,  this  being  lh«  range  of  i>rdi- 
nary  huniaii  dwellings.  Any  great  iiienawc  »r  deoroaso  of  preauir«  beyond 
these  liiuiiH  will  uHi-cl  n»l  only  the  vxit  of  ciirbonic  acid  from  and  tlie  en- 
tnoce  of  oxygen  into  the  blijin),  but,  in  varying  d^roe,  »1!  tlie  phyntoU 
and  dietnieal  proctww  of  tliR  iHKly.  A  grom  instance  of  tiii"  U  M-eii  wlien 
an  animiil  is  MniMiiiIy  Dul>j«%t(Ml  to  ii  gritit  diniinntinn  of  pnuwinrv,  lu  when 
it  ii"  plaocd  in  the  nwvitr  of  iin  iiir-pump  mid  the  reot^iver  nipidiy  cx- 
hiiuKtnd.  The  aiiimal  i:i  soon  thrown  into  final  €imviil«ii>ii»,  which  are  in 
part,  ttnlflniy  in  part,  due  to  tlie  libornlioD  of  ga«  from  ihc  blowl  wilhin 
the  biooilvrwels :  ihc  gas  so  set  free  mechanicnily  interferes  with  the  circula- 
tion, ns  by  obstructing  the  pla?  of  the  cardiac  valves,  or  by  plugging  the 
9>niiillt'r  bbwdvessels,  and  thus  hdpe  to  brin^  the  machine  to  a  uandstiU, 
Tliv  free  gas  found  in  the  vceaels  upon  examination  atler  death  is  add  to  be 
ciomposed  chiefly  of  nitrogen,  the  carbonic  acid  and  ihe  oxygen,  which  pro- 
b«bly  were  also  set  free,  having  been  reabsorbed  before  the  examiualion  was 
made. 

But,  quite  a|>ari  from  gross  efiects  of  thia  kind,  it  is  very  obvious  that  the 
organism  muM  in  many  oaya  suiter  from  a  diminution  of  prewure.  The 
ootnpl<-x  and  delicately  balanced  vascular  svstem  id  constnicted  to  work  at 
the  ordinary  atinoapheric  pressure.  U'he  toroe  of  liie  heart-beat  and  t^e 
ttmie  r  >ntriu-tion  of  the  small  arleriee  are,  so  to  apeak,  pitched  to  meet  the 
influcnrv  exerted  on  the  outside  of  the  bloodreaseU  by  the  ordinary  precaure 
of  th«  aimiMpbei^ ;  and  any  great  diminution  of  that  pressure  must  produoe 
a  Krenler  nr  law  diwir range nirut  of  ihe  vaacular  mechanism  until  it  u  ooun- 
terbalancod  by  «»niv  compensating  changes.  And  a  liltle  reflection  will 
s«M>ly  many  other  iiuUnces. 

We  liiive  alri'iidy  i-allcd  aileiition  ($,155)  to  lh<-  fuel  thai,  the  total  pK9- 
surv  of  llwr  ainiiHiphen.^  n-iiiaining  the  mine,  the  iwrtlal  pn^wuiviif  the  oxygen 
ill  the  iuHpircd  tur  muv  he  roduced  as  low  aji  about  ,6  mm.  flO  per  cent.) 
without  eerk>u»ty  nvxlifying  tlifl  respiration.  In  tmU-r  to  attain  thin  diini- 
DHtion  of  the  partiid  nrcssiire  of  the  oxygen  without  diunging  the  ooinpiuition 
of  the  atmosphere,  the  total  prewure  of  the  ntm'wphcre  niti'C  be  rvdud^l 
to  the  limit  of  :i(M  mm.,  corresponding  to  an  altitude  of  17.000  foct.  Now 
it  is  a  matter  of  common  cxpcrionoe  that  in  iMoendiitg  a  mountain  "dislraw" 


496 


is  f<'It  Inng  l>i:furc  Hiich  nn  nltitiid«  is  re»ched.     Tlw  ilistreee  fell  on  bucV 
Kccnginriii  it  probably   due  nut  so   much,  if  indeed  al  all  dirvclly,  (o  ihq 
diminution  of  axyi^eD  lu  b>  a  c^etioriil  iliaarraageiDont  uf  ihe  orRaoisni  ana: 
perliiipe  more  (iDTticiilnrlr  of  tnc  vnscular  system.     The  iiae&-bl€>eiling  whicli 
u  so  fre'iiiutiL  sn  occurrence  under  the  oircumslnDOOs  showa  that  tlie  minute 
bJoodvcwelg  more  directly  expoaed  Ut  the  diiuiuiitioD  of  ureasure  are  pro- 
foundly ndected  by  it;  and  what  is  true  of  ihetu  is,  protmbly,  in  vuiout 
ways  Kud   to  dilfereDt  degrees  true  of  (he  wljole  vaecular  aysIetD.    Tbr 
breath iea&uess  which  i»  so  mnrk«d  a  feature  on  Ibese  occasions  aeenuduB 
not  BO   amcb   to   llie  faot   that  the   blood  which  reaebca  the  respiratorj 
nervous  ceiitreo  is  deficient  iu  oxyp;en,  as  ui  the  fiii-t  that  the  tmubkfi  %-u- 
cular  Hvslein  fails  to  deliver  to  those  iviiItc!*  their  bluod  in  au  adetjuato 
(Wiioii. 

It  h  a  featnri!  of  lliv  vnitculiir  system,  and  indewl  uf  the  other  raechantuu 
of  the  body  iu  wbtdi  ticrvoun  factom  iiitcrVMic,  ibitt  tbi^v  pmaoM  the  powtr 
of  tida[>tiij^  themtolves  to  chnnged  couditioDit ;  and  il>  it  t»  ircll  known,  ibe 
huranu  urgiinium  somewhat  nipidly  become*  accuMlomtyl  to  thvr*^  mtxlrrale 
altitiidf*.  Priiciici^  and  custom  have  liir  IcMcffcd,  thi>ii"h  ibcv  havo  some, 
on  the  more  funilamcntal  nnicrKsn  depending  nn  the  net  mil  supuly  uf  oxvntD: 
and  it  in  al  the  extremis  nllitndcs,  where  in  tiddilion  to  the  olDcr  trmiDwe  a 
deiicicney  of  i<xyg<-ii  delinitcly  innki>»  itficif  felt,  that  the  body  teetat  to  &U 
in  adapting  iti^lf  lo  thi-  new  circiinwtjiiices! 

The  addition  uf  th<'>c  trotihU-e  not  directly  rcspiralory  in  nature,  when  Ifae 
«upj>ly  of  oxygvn  i*  dittiinished  by  n  diminution  of  the  total  pressure,  per- 
haps explniiis  wliy  thoui^h  an  adequate  lowering  of  pressure  will  pruauce 
n.-^liyxin.  that  nsphyxii)  is  somewhat  ditlcrent  Irom  the  ordinary  asphyxia 
duo  to  (leprivnliun  of  nir  or  oxvgeo.  Convulsions  which  are  easenlial  to 
ordinnry  asphyxia  are  at  times  wholly  absent :  the  nervous  svsteiu  uD«ler  llio 
peculiar  conditions  does  not  respmd  to  the  alimutus  of  the  lack  uf  uxygen : 
and  other  nervuus  symptoms,  suoh  ns  a  rapid  onset  of  (eebleneas  aaiuuuting 
almost  I"  paralysis,  are  apt  tu  make  tlieir  appearauoe. 

^  38t.  TliK  efferJn  of  imrm*!  n/  atmo*phmo  jirvjvure.  Theae  ara  Id  many 
ways  remarkable.  I'p  tu  a  jirewure  uf  several  utiuoapberea  of  air,  the  only 
tymptoma  which  pr»eiit  thfmM>tv<st  are  thm  somewhat  reaembliii;;  imrcoUc 
poisoning.  The  animal  become*  aleepy  mid  ntupiil,  the  result  pirdtahly  not 
so  much  uf  rwpiraloiy  chauen,  at  of  the  elfi^^to  of  the  incrctUMil  prcK>iro 
on  the  whole  orgtmiam  to  which  wr  hnv<-  juHt  alludtsl.  Al  n  prrwiiirv.  how- 
ever, of  IS  atmospheres  of  air,  or  what  amouutii  to  the  snnie  thing,  of  3 
atini«pht?rvv  of  nxy^n,  and  upward,  a  wry  reniarkahio  phenomenon  pre- 
tenlN  Itself  The  animals  die  of  asphyxia  aud  convulxions.  exactly  in  tbe 
same  way  as  when  oxygen  i^  (kficient.  Corresponding  with  tliis  it  is  found 
thui  the  production  of  carbonic  acid  is  iliroinisbed.  That  is  to  sny,  wbea 
tJiciircmnre  of  the  oxygen  is  increased  beyond  a  ccrtcin  limit,  the  axidattons 
of  tile  body  are  dimmished.  and  with  a  ttill  liirther  incressc  of  the  oxygen 
are  arrested  nllogcther.  The  oxidation  of  phosphonw  is  jwrhajM  analogous ; 
al  a  high  preesure  of  oxygen  phospborui^  will  nut  bum.  Not  only  animals, 
but  plants,  bacteria,  and  orgaui;r«d  fermi^nts,  are  similarly  killed  by  a  too 
great  prcseure  of  oxygen.  J^m 

The  Rblatio!«  op  tbb  Resviratoby  System  to  the  Vasodi^r  ajto- 

Otheb  Stbtemb. 

£  388.  Slany  events  iii  the  body  show  the  inllaence  which  the  respiratory 
moreineiit*  exert  on  the  cirrulnliun.  When  tlte  brain  of  a  living  mamnuu 
ia  exponent  by  the  removal  of  the  >kull,  a  rhythmic  rise  and  fall  of  the  i 


RKtiPlHATORT   VSTtVLXTlOSt. 


m 


i 


P 


bral  luHse.  n  pubntion  of  lh«  brain.  iiuitcdistiDct  frocn  the  niuvvmi^nts  cKuiisl 
hy  the  pulse  in  Ihe  arleriM  of  ih«  brain,  is  ob««rved :  and  ii{>iin  vxAmitialion 
it  will  M  Ibund  tliai  thcsr  iiioveiii«>te  niv  synchronoiia  with  tbe  roepiniUiry 
jnovem«oto,  tlie  brain  Tis\n^;  np  diiriii;!  exptrntioii  and  BJiikiiig  during  impiri- 
tiou.  Thty  disnp|>ear  wbeii  the  arlerioa  >;'>■■>!;  ^  the  brain  arc  li^Muraa,  or 
wlien  Ha  Tenoua  sinusea  of  the  dura  ranter  nre  litid  opcii  ho  ai  lo  admit  of  * 
ft-ce  escape  of  ihe  venous  blood.  Tbey  ei-idontly  arise  fraiu  tbe  exptratorr 
■novements  in  some  way  hind«ri»K  aud  lb«  iDBptratnrr  iiiovemeDU  aansting 
lh«  retuni  of  blood  from  the  brain.  We  have  already  ($  116)  atat«d  that 
(IuHmk  iniif'iraiion  t)i«  preasunt  of  blood  in  tbe  great  veins  may  become 
iic^tive,  i.  r,  luayHiiik  bolow  llie  pressure  ot  thealmoapliere;  and  apitneture 
of  one  of  thftv  veins  may  cau»e  dealb  by  air  beinft  aciuatly  drawn  inio  ilie 
v«in  aud  lliu*  into  the  bearl  duriiijr  an  inspiratory  imiv<'meiiL  Wli«ii  tbe 
veins  of  iin  animni  are  laid  Ixira  in  tbu  d<acIc  and  watched,  the  M-i-allcd 
puUuf  ■<c(ir>riM  may  be  obiq-rveil  in  them,  that  is,  tbey  swell  up  diirine  cxptra- 
tion  and  diminifh  again  during  insm ration.  And  indtiil  a  little  vonsiduralion 
will  i>bow  that  the  i>xiMn»i<>n  nnii  c-'intrarlti)n  of  tin;  ch(^Kt  must  have  n  da- 
cided  effecl  on  the  flow  «f  blood  (hroiijrb  tint  tbornctc  pfirlion  of,  and  Uiub 
tndirevtty  od  ihnt  through  tbe  whole  of.  the  vi^culnr  syslvm. 
This  is  well  illustrated  by  the  cffbctf  of  re:tpinili'in  on  artcria]  blood- 

E rewire.  We  hare  teta,  while  Ircnntig  »f  the  cireulalion,  that  the  arterial 
lood-nreaaure  ctirvee  arc  marked  by  undidntionv,  wbicb,  since  their  rhythm 
IB  synehronous  wilh  ihal  of  ibe  respiratory  movrments.  arc  evidently  in  some 
way  connected  wilh  refiplration.  Similar  uudnlatiuus  may  be  obsarred  in 
ibe  pulse  tracin;^  taken  from  man. 

na.  iiT. 


''H^ 


/ 


OuaraaiMS  ur  HuxM-ramL'ss  Ctsvk  yum  Cvim  ot  Iitsa'Twism-k:  raiwc-KK.  iDcn.| 
|b  ilio  bi-wd-pif  ur»  tvnv  lak*n  tv  mutiuvl  »  monun  cutuoiDclar :  ll  tliaw*  Uw  mplniUin' 

sUlluio.  iho  tUfmr  totit  ini  ihv  4««rmi(  Miis  tkt  owikcd.  A  I*  iho  r.itciv  vl  lnln-lliiin«Ii' 
I  wum  DliUIiwl  by  nitinoi-Uiiii  one  tlmb  of  ■  m*  oometcT  wllli  llic  ^Iciinl  «(li)'-  Ii»|iLr>Uon 
liaslatsl '■  *i|''n>ll4ni>t  (.  Wllb  Ibv  Ufliwliig  <>r  liM|il>aliiiii  I'l  IIicviiaiUiliMut  Itit  rhnt  niiUH 
■  ■■ubnl  fitllnr  iliomcrmiry  iDiliflntn-tlionclcBMiiomalct.  bui  tlistdkctseoiidlinliilibak  ■Hue 
ilMtMHOiHS  ■■riiiir»iliiimiilc|«aBim4cm  nol  boMon  Ike  luinomeicrtlMiKlMuai  Ihaluntsabn; 
•ikl  4*  Um  ioiigt  •vpAiKl  moTvaadmanilwiklUiiilifaianriiry  b«am«ahnt  mkI  Um  until  tovard 
llinfnitt  iif  Iwttfiitliiii  llii>  <«rre  tcoonicsirBp' lunrlykitnlglitllnt.  Cvnveatlr,  Uta  ivluni  or  ilir 
ulwtl  M  tbi>  l*i;li>n|ii||  of  aittmtian  frt  |>p»liinB  nl  nnt  ■  mitrlud  riic  of  (bu  incnurY  In  Un 
Wlliininliir    tml  Ibli  «nn  mw«  u  Uw  ulr  Iimvm  ttio  ah*(l  11114  lb*  Iiiiih*  (brliik,  iiti«nn>pan  Its 

curr  (kill  ilonTf. 


Wlieu  these  uiidnlalioiia  of  the  blood-pnwMiro  curve  arc  compared  care- 
fully with  the  rospirntory  movements  ur  with  ihi-  variations  of  inira-lliuracio 
jireasure.  what  is  most  commonly  olwcrved  i»  Ihnt  while  the  blood.preaaure, 
uu  the  whole,  rises  during  inspiration  and  falls  during  expiration  ueitlier  the 
nae  miir  tbe  fall  ise.taclly  syncbrunous  nith  either  iiupiration  or  expiration 


Fig.  147  fiGSwCTwRiiiciiig*  from  n  ilog  lalii.-ii  nt  the  MinMiniT^w^ir 
■be  ordiDiiry  blooll■]'n'i•^klrl,■  cunv  Inm  ila-  ciiixitid,  iiml  llic  olhrr.  h.  «[  ^ 
fCnling  tho  <-oiu)iltt'n  tij'  itic  iiitrii-tbunioic  prni#urc  ■«  obUinnl  by  carvlml^ 
bringine  n  lunnomtlcr  iiilD  oniini-i-tKiii  with  lli«  i>kuni]  citvitjr.  On  rom- 
pnriiig  lilt?  IV.XI  curvet  it  ie  evidvot  ihui  ucithtrr  the  rue  nor  the  ftitl  of  nrlcrial 
prmiirc  cniiicitli's  exactly  dUier  nilli  ii)«pirnl)on  or  witb  cxpiroiion.  At 
the  beginning  <ir  iti^pinitiun  (i)  the  nrteml  pirsiuro  ia  seen  to  be  falling  ;  k 
euoti,  lionevcr,  tiegiH^  to  rise,  but  dura  not  reach  ibc  iDaximiiiu  until  son 
lime  alVr  cxpirotion  (f)  hui  begun ;  the  Inll  eontinues  during  the  rvniaiDder 
of  expiration,  ond  psffcs  on  into  the  eiieceedtng  inepiralion.  Tbis  mgRetU 
the  idea  ibal,  while  inepirntiun  Und*  to  iner«aee  and  expiralioD  to  diminith 
the  bloud-prceeure,  there  ore  causes  at  work  which  in  each  oaae  delay  ibe 
effect. 

Extended  obscrTatioDB.  however,  thaw  that  such  a  reJation  oj  that  ilioirn 
in  ibe  dgure,  though  fre(|ueDi,  is  not  coosiant.  in  fad.  Ihe  eOecm  of  ilic 
re«iiiralory  movciuents  on  blood-preasure  are  found  to  vary  %-eiy  widely 
according  as  ibc  reapimlion  ia  <juick  or  slow,  easy  and  »hulluw,  or  Inborn 
and  deep,  uud  eapednlly  as  (lie  air  euiera  into  the  chat  readily  <ir  with  diffi- 
culty. Mcreuver,  rt^piratonF'  undulalioua  of  blood-prewure  are  teen  not  i»nly 
with  nntuml  but  ulso  with  artificial  redpiratiuo  ;  tn  tli<-  Intlcr  the  ntccbnnini'l 
cundilion;!  are  to  a  large  exicnt  the  reverse  of  iho»e  of  ihc  fonaer.  and  might 
fairlv  be  csjicctei)  to  aftbci  the  circulation  in  u  dilTerent  way.  The  (-iui'>.iti>)<i 
of  IIKVC  rcvpiralory  uudulationd  iw,  in  fact,  complex.  Tbr  rcspiriitorT  act 
allccUt  the  vuNeuliir  »yiitt>ui  iu  nevrnd  dlfierent  way>.  and  the  eenernl  elTect 
vanes  according  a*  one  or  nlhcr  indui-nce  is  prrd»minunl.  The«?  several 
nction«  are  suffi<'i<-ntly  intertvlin;;  nml  inigiorliinl  tu  doterve  discuMion. 

§  383.  TIic  heart  iind  gn'nt  hloodvi-Melii  arc,  lilce  ihe  lungs,  phiccd  in  the 
air-tight  thoracic  cavity,  and  are  subject  like  the  luiigK  to  tho  pumping  acttoa 
of  tho  rotpiralorj-  movement*.  Were  there  nu  longs  present  in  the  chest, 
the  whole  Ibrcc  of  the  cxpitneiuQ  of  the  thorax  in  inspiration  would  be 
directed  to  drawing  blood  from  the  extra- thoracic  veBselti  toward  the  brart. 
and  convereely  in  espiraltou  the  eHect  of  the  return  of  the  thorax  to  lU 
previous  dimensions  would  be  to  drive  the  blood  thuB  drawn  in  back  again 
iWini  the  heart  toward  the  extra  llioraeic  veasela.  And,  even  in  the  iireweo 
of  the  lungs,  some  of  tbis  clTeet  is  still  felt.  The  main  purpose  and  tW  main 
result  of  tne  expansJon  of  the  chest  in  inspiration  is.  of  cuune,  to  draw  nir 
into  the  lungs;  oy  that  expansion  the  air  in  the  puluionnry  alveoli  is  rnrilied 
and  brouuht  to  a  lower  j)n?S£ure  than  that  of  llie  alin(«]ilicrc  outside  (be 
cheat;  and  the  diflerence  of  pressure  thus  set  up  lead^t  to  an  inni<h  of 
inspired  air  until  an  ei|uilihrium  of  prcasure  is  esiabliohed  l>ciwccn  the  air 
in  (he  lungA  und  thai  outside  the  cbetit.  Ilefore,  however,  ihe  inspired  air 
can  Gil  a  pulmonary  alveolus  the  eloMic  wallti  of  the  alvci^lus  have  to  be  dil- 
tcndeil,  and  that  disteunion  i«  ellecleil  by  means  of  (be  prtmure  which  caWM 
Ihe  iuspircd  air  to  ruter.  Part  of  the  atiuMpheric  i^imvitre.  in  fad.  whieb 
cauMa  the  entrance  of  (he  air  into  the  lung  is  fpi'm  ni  overcomiug  the  elas- 
iicitr  of  (he  pulmonary  panagt*  nud  <*lls.  So  tlmt  while  by  the  inrush  of 
inspired  nir  the  diflerencc  of  |)re9>t>ur«  between  the  nir  inside  the  puInioDatT 
alveoli  and  ibnl  outside  (he  ('h(x(,  brought  about  by  (he  thoracic  expanaioa, 
is  completely  neulmli7<ed,  ilie  difference  between  the  pressure  to  which  the 
parte  lying  within  the  thorax,  but  uulsidc  the  lung«,  are  exposed  and  (hat 
ou(eide  the  chest  is  not  to  completely  neutralized.  The  pressure  on  these 
patU  always  falls  short  of  the  prcMiire  of  the  atmosphere  by  the  amount  of 
pnature  ncccstary  to  counlerbalnnco  the  elasticity  of  the  pulmonary  nnsBa|[W 
and  alveoli.  Conse(|uenlly,  any  structure  lying  within  the  thorax,  nut  out- 
side llui  luug6,  is  never,  even  at  the  conclusion  of  an  inspirativii,  when  lbs 


I 


» 


MTo  lilli'd  nrilh  nir,  eubJMt  to  a  prcMiira  m  great  m  that  of  ibe  iiltnM- 
|>lM>rt<.  Ad(I,  Mnc«  Ihe  rraotion  of  lli«  nlnxteph^ric  preMura  which  is  ihut 
e|>«-tit  in  distcmting  tlw  lun)^  inPTvasps  »»  ihe  lungs  boconie  mi>r«  imii  tnoro 
sIreteWI.  it  follows  tbal  ihc  t'ullpr  the  inspiriitlon  tile  i^renlvr  i»  th«  (lilloivnM 
brlneen  the  prentiro  on  strucltired  within  the  thorax,  but  nulside  the  luna» 
and  the  ordinary  prenure  of  the  stmoephere.  Now,  w«  hnvo  seen  that  ibe 
prvaiire  nwenarjr  (o  cauiiterhalcnce  Ibe  elasticity  of  ihe  lun)^.  when  lliey 
are  completely  at  rest  (in  the  pause  between  expiration  nnd  inspinilioD),  is 
in  niaD  about  5  to  7  mm.  of  mercury,  and  that  uhen  the  lun^  are  fully  dis- 
tended, as  at  the  end  uf  a  forcible  iuapiralinn.  the  praeeure  rma  to  as  much 
aa  ;10  mm.  of  mercurv.     Hence,  at  (he  hei^'hc  of  a  forcible  inspiration  the 

trei^iire  e.terled  ^^u  llie  lit«rl  and  ^reat  veeaela  within  the  thorax  U  30  mm. 
»i  ifaau  tlic  ordinary'  atnioapherii^  preraure  of  760  mm.,  and  even  wlien  Uie 
chnt  ia  comjdetel)'  at  reitt,  nt  Ihu  end  of  aa  expiraiion,  tlie  preaiuro  on  the 
bean  and  f;reat  VMm-lit  i*  «li;|chtlr  (by  iihnut  0  mm.  of  mercury)  below  tl»l  of 
the  atmoatibere.  We  may  a<ld  tlial  any  ultntitcle  tu  thu  free  ingrMt  of  tlie 
iuipired  air,  any  diflicully  in  the  full  cx|>itii»ii>n  of  the  pulmoiinry  ulveoli,  of 
course  inrrai»*=i  tlw  negative  pn-wiire  to  which  the  thoracic  iitnictiiri!!(  out- 
side the  luugTt  iirr  Mibjrcted  by  the  ex|uin»ion  of  the  cbwi.  Hence,  when 
tlie  (rueh«a  it  clawed  a  vi-ry  lar|2c  jmrt  of  the  thorado  expanHiun  in  directwl 
to  inereiuing  the  nc^tirc  prcMure  around  tbe  heart  and  grmt  blood veMM'l:*. 
During  an  inspiration,  then,  the  preniirenrnuiid  the  hejirt  un<l  gn-at  blood- 
Twwla  Itecomn  conttdembly  lf«e  than  that  of  the  atmovpherc  on  the  ve^M^la 
OUtsUlo  (ho  tborax.  During  expiration  thin  prcuure  returns  tonard  that  of 
the  atmoxpherc,  but  in  ordinary  breathing  never  quitfi  reaches  it.  It  is  only 
ill  forcible  exjiiralion  that  the  preMnr«  on  the  thoracic  vascular  organs 
iH-acltw  or  cxece<l»  that  of  the  atmosphere.  But  if  durinc  inspiration  th« 
pmwun.-  iK'arini;  on  the  ri>;ht  auricle  and  the  venie  cav-v  become  Iceh  than 
the  jmtwire  which  »  bearing  on  the  ju((tdar,  subclavian,  and  olh«r  vmita 
outMde  the  thurax,  this  must  result  in  an  increased  tlow  from  the  latter  into 
iIk-  former.  Ilenc*.  duriuK  each  iitut  pi  ration  a  larger  (juantity  of  blood  enters 
ibc  right  side  of  the  rtKht,  Thia  pruliably  leada  to  a  Htronger  stroke  of  the 
htarl.  Biwl  at  all  eventii  eausea  a  larger  <|uantity  to  be  ejected  by  the  right 
ventricle  ;  th»  causea  a  larger  quantity  to  escape  from  the  left  ventricle,  and 
thus  more  blood  is  thrtiwn  tnto  the  aorta,  and  the  arterial  pressure  propor- 
tionalely  inoreawd.     During  expiration   the  converge  takes  place.     The 

ErtSRire  on  the  intra-thoracic  bloodvnuieU  ivturns  to  the  normal,  the  How  of 
lood  from  the  vein*  outWKle  the  thorax  into  the  venie  cavat  ami  n^ht  auricle 
is  no  longer  asaisied,  and  in  r<>iiMt{ucncc  Icm  blood  passefl  through  the  heart 
into  tlie  aorta,  ami  srti^rial  prvssuro  fall*  again.  During  forced  ex pjrat ion 
tite  intra-tiiofocic  prt-wuri.'  may  tw  so  great  as  tn  afford  a  diatiiict  obstacle  to 
the  Bow  fhun  the  vein*  into  the  boarL 

The  e&evt  of  the  r<vpir»t<>rr  movcnienls  on  lh«  art«ri««  ia  naturally  ditfer- 
ent  fium  that  on  the  vcinv  During  itupiralioii  the  diminution  of  ]ira«uro 
ill  (be  tlM>nix  around  the  aortic  airb  tends  to  oxnaml  the  aortic  arrh  and 
thu«  to  che<rk  the  oiinai^l  tlow  of  b!«<>d  and  to  dimmish  the  preasun-  «if  bliiod 
within  the  aoitii.  During  expiration  the  increase  of  nreMUrc  outnide  the 
aortic  arch  uf  courra  tends  to  increase  also  the  blooil  pniwure  \vithin  lh« 
aorta,  acting  in  fact  jusi  in  the  same  iray  as  if  the  coats  of  the  noria  thcm- 
Kwlvm  contracted.  Thus,  as  far  as  tulcrial  blood-presaiiro  it  conccmerl.  the 
eflectif  of  the  respiratory  movements  on  the  great  veins  and  grent  arteric* 
re«[>cc1)vuly  are  aiilognnistic  to  each  other ;  the  effect  on  the  vein*  being  to 
increase  arterial  iir(«»ureduring  inspiration  and  to  diminish  it  during  cxjiini- 
tioii.  while  the  Hiect  on  llie  arteriw  is  to  diminish  urterial  pn^««urc  during 
inspiration  and  to  iuerense  il  during  expiration.    But  we  should  oaUirally 


«ESI'11tATI0K. 


ez[>cci  [he  effect  on  ilie  lli  in -wallet)  vcJti.t  to  be  greaicr  Ituui  (hat  »n  ibi^ 
etuul,  Uiiclc-Kallvil  arivrieit.  su  luticli  »o  thnt  tlw  direct  tftvcX  ud  i1i«  arteri» 
may  be  ueKlect«<l.  Tliul  is  u>  Har,  we  sbould  expcd  Utc  bltwcl-prcMun'  Ut 
nM  during  iiiiiii>i ration  ami  to  lull  liuring  ex{Hration.  Tht*,  n»  wo  havr  k<ci). 
i«  frcc|iH-iil1r  tati  cane,  um),  iixli-eil,  n)i«ii  llie  breathing  i»  decii  nitd  laborcK), 
wul  M|>c<rinllr  doriiig  violent  and  iindili^n  rexpirittary  inorciiie»t«,  llir  inHu- 
encn  in  tbi»  (lirvi'lion  on  the  blood  ■]in-».'>iiri:  mrve  of  tlte  piimpitig  ncttoa  of 
ll)D  chmt  in  nninislaknldc. 

In  iill<ini|itin^'.  hnwi^vcr,  to  Mitniate  the  tffeci  itf  the  roipimlnrf' ninrsoMnib 
oil  blwHl-pn'-wurr  tvr  mini  li<-iir  in  mind  wbiit  in  Inking  pince  in  tlie  sbilooMfi. 
In  iiispirniioii  the  dtwi-nt  of  the  dinjihrogm  <-»ni|ircHiv  tUc  nbdominti)  viscera, 
and  M,  wbik'  iil  tlir  vcrj-  liml  it  drivw  ■  nuiintity  of  blood  onward  niong  tbe 
infei-ior  vonn  I'avn,  i>iili»c<iu<MilU'  binder*  the  upward  How  from  the  abduiueo 
and  lowrr  limh«:  nt  llic  nimu-  time,  by  (^miprvMiog  the  abdominal  aorta, 
it  tend«  to  niisc  the  prfwaurv  in  ibr  thoracic  aorta  and  its  brnncbea,  while 
lowering  thai  of  tliv  abdominal  iiorin  and  its  branches.  Tlie  elli.>ct  of  bmt 
expirntion  would  be  the  I'onversc  of  lhii>;  but  in  forced  expiration  tlw 
prewure  of  the  contracling  abdominal  mu»clc»  would,  as  tu  ioapimtion, 
ant  tend  to  drive  the  blood  onward  along  the  vena  cava,  but  aiihsequentlv 
to  hinder  the  flow  both  along  the  vena  cava  and  the  aorta-  The  ef^-t  of  the 
abdominal  movements  therefore  U  mixed  and  variable,  and  tbcir  indiKUc* 
on  the  blood- pressure  in  the  femoral  artery  muBl  be  dilferent  from  thai  on 
tbe  radial  arien*  or  other  branch  of  the  tborado  aorta.  It  w  difficult  |a 
pre<liel  what  in  nil  cases  the  eflect  would  be ;  and  the  matter  cannot  b«  mi- 
llod  bv  el i initiating'  the  movetnents  of  tbe  diaplirai^m  throiiifb  iu»ction  of  tba 
phn^nic  nervL-o,  HJuoe  iu  such  a  case  the  nlii>k-  working  of  the  rej|»irauirf 
puiup  i.4  tnaliirially  all^cie<l. 

^  3M.  Ill  nddiii'm  hi  the  tnAiu-ncv  thui>  exerted  by  thiMhonidc  tnoTenenU 
on  thi-  great  vein»  hiding  to  and  the  grvat  arteries  leading  from  the  heart, 
we  have  to  consider  iho  bohavtor  of  tho  pulnionarvrci>scl»  iheniselvea  under 
the  varving  thoracic  prnaurc.  ThcM.  like  the  venai  caw  and  aortn.  tend 
to  expand  un<ler  the  influence  of  the  inspiratory  cx|KiDsion  of  the  che»l.  and 
thuH  to  becotnc  fuller  of  blood,  very  much  as  they  iraiild  if  the  whole  btiif 
were  placed  under  a  large  cupping-gla».  The  lirst  elfect  of  tbit  incmwoa 
filling  of  the  pulmonary  vewels  would  bo  to  retain  tor  a  while  a  ivrtaio 
(|uaQtilj  of  blood  in  the  lungs  and  thus  to  lea»eu  tbe  amount  Inlliiig  into  thr 
left  auricle.  But  this  would  be  temporary  only,  and  tlie  widening  of  the 
pulmonary  veseelsnotild  speedily  produce  an  exacllv  contrary  elTerl.  naiuvly. 
an  increattcd  flow  through  the  liinKS  due  lo  the  diniiuiohid  rufi»taiico  oBerod 
by  tJie  widened  pasmgn.  Convenicly.  the  first  etlect  of  ex|>inttii>n  would  be 
an  increased  flow  into  the  leH  auricle  clue  to  tbe  additional  iiuiiniity  of  blood' 
driven  Mivrard  by  the  partial  colla{K)L-  of  thr  pulmonary  veMrl>,  foliowot  by 
a  moT«  ugnifieiml  ilimintalieil  floiv  cauoiii  Iiy  the  greater  nvixliince  niw 
olTervd  by  the  namin'or  vascular  channels.  Thii5  lh«  d&ct  of  iiinpiration  in 
ii»i  way  wouM  Im'  tir>l  tti  diiniiiUh  the  flaw  into  the  left  auricle  and  «u  itilo 
the  It'ft  vi-nlricle,  but  nflcrwnrd,  for  the  rent  of  thn  inn  pi  rat  ion  until  ihe 
beginning  of  expimtion,  to  incrtiuc  the  flow  into  the  vcntricio :  while  con- 
veriely  the  cH'rct  of  exiiiratioD  would  be  linrt,  for  a  brief  period,  lo  increase 
and  aitcrward,  during  tlie  rret  of  the  movement,  to  diminish  the  flow  of  blond 
into  tl>c  left  ventricle.  Further,  while  tlii«  may  be  coniidered  as  tbe  efleet 
on  tli«  pulmonary  vtMola,  large  and  small  taken  altu^ther.  the  inHueuoe 
both  of  tbe  thoracic  negative  pressure  durinc  inipiration,  and  the  return  iu 
a  positive  direction  during  expiration,  will  near  more  o«  (be  Ibiu-walled  < 
iHilmoniiry  vrins  than  on  tbe  stouter  pulmonary  artery;  that  is  ta  mj, 
■DBpinitHHi  betxNtiea  eelnbli»lied,  there  will  be  »  dimiuutiou  <>f  pressure  in  l]i« 


BBSPln^TnUY    I'SDCt ATIOXH. 


601 


pulraooary  vdns  crntlcr  tliaii  tbnt  in  the  pulmonary  »nm-,aiii)  l)iia  nill  Iw 
SD  ■italilionnl  iiilliionre  fnvonnt;  the  Row  iiilo  Llie  l«fl  veniriric;  during 
vxpimtioci  a  nmilar  tlitlerence  nf  offecl  will  be  fell  iu  the  contrary  direction. 
Daribfi  the  incmse  of  tinw  into  ttie  ventricle  the-  'lunnlily  of  blood  ejected 
tt  «*cflflroike  itill  incrcaMt.  and  each  stroke  will  (^  1<>2)  be  incrensed  in  vi^or, 
io  eoaM()a«-nce  of  ubich  tlie  arlertal  pnMure  nill  ride.  C'onverwlr,  during 
tb*  decraue  of  lluw  into  tb«  ventricle  ibu  iirteritil  jirewure  Mtll  iiill.  IIcDce 
U>e  mienil  eHrct  of  tbc  n>iivvmeiil«  of  ibi?  cheut  un  the  piilmonHrr  veesels 
will  be  duriu):  the  )>f(tinniti){  i>f  impiiiilinn  tn  i-cmiiniiu  (he  luwcHn;-  ot'  arterial 
IWiwarr.  whtL-h  wu  taking*  (iIiicl-  ihirint;  t^xpimli'in  but  [iubiie(|iieuily  to  raiM 
llwarlprni  prvMiun-;  nnilcunri-Rii'lyiit  the  lieginnini^iifexnirntiuu  tOL-oDtinufl 
Umrinof  arlvrialpnamtn'  uhicli  wiu  (akine  place;  ilnrioe  iii.ipinition  bulsub- 
K^urntlr  til  Inuer  urlrrinl  prcfwire-  In  i>ri1innrv  brcuthing,  hs  ir«  hnve  tteen, 
vbal  tnay  be  conwdcreH  n»  the  normal  ivlntiniunf  blood-prettture  lo  llie  ntpirn- 
kry  tniiTpninibi  ar«  tmciwly  of  this  kind. 

i  3M.  KflW'ti*  of  lb*  rw|>imtnry  morements,  however,  are  •ren  n<ii  unlv  to 
aataral  but  abu  in  artiticial  re»prmtioii.  When,  for  instance,  in  an  animal 
■uxtvr  urnri.  anilicin)   is  substituted  for  ualural  reepimtion.  undulntionn  of 

thn  bIt'Ni-pnwure  curve,  syni.-hroD<ius  vith  the  reflpimtory  ninvcnicnbi.  iirv 

anill  olwem-d  (Fi);.  14?*),  tbough  generally   leas  in  extent  than  th(w«  Ken 

timlrr  nnlural  conditions. 

NnH  in  uriiticiat  reapiration,  tlie  mei'lianioal  conditions  under  which  iho 

tirw'ic  viscera  are  placed  a*  re^urdj^  proii^ure  ai>e  tbi-  exact  opposite  of  ihoM 

during  natural  respiration,  for  nbcu  air  is  blown  into  the  trachea  lo 

Uw  lunga,  the  prea»ure  >viibiii  tbc  clieH  ia  increased  instead  of 

^linitntshed.  Under  theae  circumstances,  nppJving  the  conaideratioiu  Ittul 
tittnn  in  the  procedint;  paragraph  with  regard  to  natural  respiration,  we 
■Inuld  ex|)eet  to  find  that  while  the  firU  eAict  of  an  artificial  inspiration 

Kid  be  to  drive  an  additional  ijnnniitr  of  blood  out  of  the  litrign  into  the 
rtotiicle.  nnd  (hue  to  raimt  arterial  pressure.  thi»  wotdd  he  in  turn  fol- 
>d  by  a  fall  of  arterial  pnvsuro  due  to  the  incrmsed  rvsintaiice  olfered 
both  to  (he  pMMge  of  blood  thn>ugh  tho  lungs  and  to  the  entrance  of  blutxl 
ihmugb  the  vtam  C9r»  into  tbc  right  auricle.  C-onverscly,  tlio  eflcrl  of  the 
Mcvecoing  expiralitm  would  be  an  initiiil  continuance  of  the  lalt  of  arloriiU 
proanre  tuenxded  by  a  rise.  In  other  words,  we  should  expect  to  lind  In 
artificial  reapiration  effects  exactly  the  reverse  of  thuse  which  we  lind  in 
aortnal  reapiralion  :  and  inde«<l  in  many  curvee  of  blood' pressure  taken 
4uring  artihcial  reftpiniiiun  tbi«  is  die  am.: 

Bota  in  natural  and  in  ani^cial  respiration,  however,  the  featurw  of  tbc 
Uood-pmmre  curve  vary  iiccordinfc  as  the  breathing  is  burrie<l  or  flow, 
■halhiw  or  deep,  aixl  according  to  the  facility  irith  which  uir  enters  the 
cbf»l,  so  much  ao  that  at  [iin«)  ibc  bloo<)-prewiur«  curvea  of  natural  and 
arttticial  reBpiruttiui  may  cluiely  memble  each  other.  And  a  liitJe  nio- 
•ideralicn  wutdd  leud  uv  to  cxjiect  thii. 

We  ha<re  M«n  that  the  nw  in  arterial  pri-»iiri-  w  hich  miirk.i  the  respiratory 
undulalion  is  in  tl>e  niatii  due  tn  a  leni|Hirnry  greiitt-r  amuiint  uf  blcxxl  thrown 
into  the  aorta  by  tbo  left  ventricle,  nnd  thai  r<irr(v|>(mdingly  the  fall  nf  pres- 
sure runiplrting  tbc  undulation  iit  in  tbc  nuiin  due  to  a  tcmjiorary  lessening 
of  the  amount  hi  thrown.  Though  the  cnuN-a  diwuKwd  in  ^  Sl^:!  undoubtedly 
make  iheniiwlvw  promim'nt  in  liibowi  nnd  vioK-nt  renpirntory  movements, 
«t  may  mficlude  that  in  onlinary  n-xpiratinn.  Ixxb  natural  and  artificial,  the 
main  rvent*  prodnring  the  reiipiratory  undulations  are  (bcwe  di»cti»MHl  iu 
f  asi.  Wb  may  restate  ihe  conclusions  of  that  dismasi'rti  by  *aying  that  the 
ropiraturv  inoraments  alli'ct  iIh-  aniouiii  uf  flow  of  blood  into  tbc  left  vidi- 
t  Ml  the  disebnrge  of  blomt  fDiti  the  loll  ventricle  into  the  a>irta,  in 


two  inniti  nnrs.  In  tliclimplHcc.  ihnnii^'h  [li>' widening;  w  narmwini;  of  tK« 
pulmoDnry  vcMt-ls  tlioy  nller  llic  (Mi|Micil y  of  tlie  vc^ttels  to  liolil  liluinl  fur  (lie 
lime  being.  Id  the  spcoml  place,  in  ci>iKei|ueiice  of  ihe  diUvrenru  of  n«i«t- 
anoe,  flccntttoneil  by  the  uidening  or  narrowing,  ihey  alter  tb»  mic  vf  Haw 
ihrnogh  tbe  pulnuiuary  vewel§.  The  tint  fuclor  id  m  bnof  nml  |wiMtiug  titM; 
the  extra  room  due  to  widening  ia  souu  tilled  np,  tbe  namiw«d  v<r(McU  mmb 
dbcIiiu-Ke  the  (luantitr  which  tlieir  can  no  lun^rpr  bold.  Bui  lb**  awotij 
factor  u>  It  more  lajiiiiijt  one;  ao  louc  tm  la  tlw  rtwpinilory  iiinremtot 
ibe  vumcIh  remain  wideneil  or  narrowed  hu  loog  u  the  iiite  of  tUm 
incTCAK'd  or  diminished.  Theiie  two  fuotdry  pnidun-  "ppiMie  eflrclB,  ami 
hence  tb«  the  lolnl  result  of  any  imrtJculsr  kind  nf  rapinition  ivill  (l^wo<l 
on  tboir  rulntivi*  pro  mint- nee.  Wilb  'jijicklv  m|(e«i«l  re«pinilory  more- 
Dieni»  tbf  lirat  foclor  t-oni.w  to  tbe  fnuit ;  ivhcn  the  n^pirol'Ty  nioveiMSti 
are  more  slimly  n-.iii-iittd  and  niorr  «lowIy  cnrricd  ant  tbp  eecond  faelor  ii 
the  nior>-  polctJl.  Hciin*  it  cnnK-M  ttl>iiut  thai  io  'juickly  lepciiled  ani&cial 
respimtioii  whvre  the  fint  factor  is  pmloininanl.  and  the  prominent  eSM  of 
each  intlalion  i»  Io  diminii'h  tin-  mpiicity  of,  iind  eo  to  empty  (lie  pulioooaiy 
veiidet"  and  to  iiici'riv»c  thti  H<iv  intu  ilie  v-niriclc  whereby  (he  pmsura  riici 
in  inllitiion,  tbnt  ii  in  in»pimii<in,  (he  liloo'l-prtMiire  curve  Miniubi(«8  that  of 
a  slovly  repented  naliinil  rc»piralion,  where  ibo  pressure  aUn  riaes  iu  iiu|)ira- 
tiou,  Imt  where.  llu'  second  fiiclor  liciiii;  predominaui,  tbe  rise  of  preimire 
bn>iit{bt  about  by  each  iniipiraliun  u  due  muinlv  to  the  more  rajud  How 
throuKli  tbe  widened  pulmonary  veaBol&  Aad  oilier  illuatmtiitiu  uf  a  like 
kind  I'ouhl  be  pvcn. 

S  386.  Ilesldw  tbe  mechanical  effccU  of  tbe  respiratory  raovements  tbe 
vucular  system  ia  influenced  by  refipiralion  throuKb  the  changes  iu  thv  gaxa 
of  tbe  blood. 

rhanf[«s  in  tbe  blood  may  aSect  on  the  one  liand  tbe  vaMtootor  syatcm 
and  on  ibe  other  hand  tb^  heart.  They  may  further  afl^t  the  bean  ritlier 
directly  by  acting  "n  the  cardiac  lissuen  or  iiidins;tly  by  means  of  iW 
inhibitory  and  augmrntur  cardiac  nerves.  They  may  almi  probably  affect 
tbe  inTipbcnil  v<»cls,  nol  only  tliroiigb  vnwmotor  ncrvec  hut  by  acting 
directly  on  ibc  watU  of  tbp  smaller  vcmoIi!.  Wc  hiire  indications  of  an 
action  of  mpirali<m  on  tbe  cnnlio  inhiUil»ry  tnlvm,  even  io  normal  iniei 
respiration.  0nc8lrikincf«aluro  of  the  r<9pi1-.1^>^y  undulation  io  the  blood- 
preoMire  curve  of  the  dog*  is  the  fact  thitt  Ibn  piilw-mie  n  i)uick«D«<l  duriuu 
tlie  rise  of  the  iiiidulatioii  and  b<-i'<imcJt  ^ilovter  during  Ibe  fall ;  see  l'i){.  147. 
A  similar  influence  mny  be  *ven  in  piilse-traciugt  taken  from  ntau.  Tbe 
quickening  of  (he  beat  might  be  coni^iitcml  a»  itself  partly  accounting  fur 
Uie  rise  of  prcaaiire.or  on  the  other  hand  it  might  be  urged  tlial  the  incretued 
floir  of  blood  which  craiuee  the  rise  of  preraure.  at  tlie  Miuie  time  leudti  to  ilie 
r|uickening  of  the  beat,  were  it  not  for  one  laol.  vis ,  that  the  dtHerL'uce  is  ai 
once  dune  away  with,  without  any  other  essential  change  iu  the  undulatMnw, 
by  iieclion  of  both  vague  nerre?.  Evidently  the  slomer  i>ulse  diirin;;  llie  fidi 
is  ottued  bv  a  coincident  stimulation  of  the  canlio-luhiliitury  centre  iti  the 
tnrdulb  oblongata,  lh«  (|uieker  puliw  daring  the  rii»e  being  duu  to  (he  fact 
thai,  duHng  that  interval,  (he  centre  U  cuinparalively  at  rRC  Wu  have 
her«  iodioatious  that,  while  the  respiratory  centre  in  ibe  nicilulla  obluogMa 
is  at  work,  sending  out  rhytbmli-  inipiiUea  of  iuspiration  antl  cxpiraiioo,  tb* 
oeigtdioHii^'  card iii-inhibi lory  i-eutie  is.  lU  it  w«re  l>y  :'yiu|>athy,  (brown  Eoto 
nn  activity  <d'  .luch  a  kind  ibal  its  intluirnce  over  the  hciirt  wa\i?i  with  vadi 
cxpimtiou  aiiil  wanes  wilh  each  iunpirution.  We  cannot  a^  yrt  explain 
eiacllv  the  manner  in  which  (he  a«.'livitv  of  the  <>ni-  eculrv  iiiflitiiices  thai  of 


>  tnUienMU.tlMrMiiimioij'uiKluluIlonsiliniish  wallnurkisd.  p(«wM>rtrrtinnndlKcHnM*t 
fuk»-nlo  la  tb«  rbt  knit  Ikll. 


BKSI'IRATOHY    UKDUIATIONS. 


903 


it  may  Ite  tlmt  <)iirint;  iIk;  uxpiratnry  phtutc  ibe  blood  Kockln^ 
In  H  aai  i]iiit£  «>  vrell  urUiriiklitwl,  tupttcially  m  fur  tu  the  vsciipc  of 
vnrli'inic  add  it  oiiccrnt^il,  lu  during  thv  inipirnlitry  nbiuc,  kckI  tlmt  the 
4:nr(lii>-inlittiitc>ry  criiln;  in  Kuffidi-ni))-  xen^tu'e  In  ii{»]>n-c)ste  lh«  ilight  differ- 
vac«;  Imt  nf  thii'  wc  ojuinol  be  miro. 

j  387.  Who4i  tiiroiigh  iiili>rt«rcncp  >r!tli  tli«  ptilraonnrv  iiilcrchKiig«  the 
lilmxl  cnit  out  from  tbo  l«ft  rvntricte  bi>coinm  nnd  continiiM  to  be  toM 
MrU'Hnlixeil  ibnn  nounl.  the  oITl-cU  oil  both  the  Iicart  and  the  vjuoiaotor 
Hvalvm  bwome  conipicuoiii.  The  rhythm  of  llie  hc^arl-brats  is  moat  distinctly 
sluncil.  This,  under  ordinnry  circunutanotf  when  the  vn^jun  nervei  are 
intflcl,  hi  probably  in  pnrl  the  r«siilt  of  vaRUa  inhibitiot),  the  veiioiia  blood, 
a?  sUK)jeet«d  above,  atiniulntiii;^  llio  cardio'iiihibitory  centra  in  the  nieditlla. 
But  toe  frlowio);  in  not  vhoily  caused  in  this  way,  for  it  is  Still  moHpicuous  in 
■u  animal  placed  under  nrnri  nnd  with  both  v:i>;ii^  uervea  divided,  dunpare 
currea  3  and  4  with  I  and  2  in  Fij{.  148.  How  thia  slowiii);  1b  broiidu  nb»ut 
b  not  very  clear.  When  veuoiu  blM>d  is  sent  thiuugh  an  excised  lieurl,  the 
beat  is,  it  b  true,  slowed,  but  it  is  aUa  and  still  more  oondpicutmsly  weakened. 
N'ow  vrben  the  blood  becomes  too  v«uou!i,  a.-i  is  shown  in  Fi^.  14J*,  «ven  ntler 
the  action  of  the  vaxuH  nervett  has  het^n  eliminated  by  suction  and  als>i  by 
urari,  the  alonini^  is  out  of  pri)|M>rli<m  to  tb«  weakotiin/.  siuoe,  as  we  shall 
presently  see,  the  blood -preMtirf  rif^ea  ;  and  though  that  rii«e  i.->  ohi<-tly  due  to 
vaaomoitor  coiiMrieiion,  still  it  could  nut  (uko  plac^  if  tbc  cardia<-  slnilcc  v-hte 
T«ri-  notably  WL-aki^ned.  It  may  W  thst  the  vvnous  blood  miniulaCes  the 
cvuxliu!  augmcnfir  uK-chnuium  in  such  a  wav  lu  to  brint:  ab:iiit  an  augmenla- 
tioii  of  iIm'  canliar  iilrokp  rather  llinti  a  quickening  of  the  rliythm  ;  but  thi# 
luu  not  l>cen  ddiiiitdly  provcil.  In  anv  caiw  a  slow  biiil,  with  such  a  inain- 
tMMUoe  of  til'-  Kirctiglh  »t'  the  cardiac  strokm  as  permit«  Uie  conliuuauce  for 
•ome  COBslderahlc  lime  of  a  high  b1ood>prM8urc,  i«  met  wh«D  the  urlerinliut- 
ti'M>  of  tbc  blood  is  inu'rfcn.-<l  with.  S>oDer  or  tat4.T,  howov«r.  the  delicioiKy 
uf  oxyiieit  in  tbo  blood  diminishes  the  store  of  cxploeiv«  compoands  in  tbft 
canliiiv  rauoculor  Bubttanoc.  ihc  ImuUs  lawn  ID  force,  oAen  showing  a  1«4U- 
porarr  increase  io  fre<]uency,  and  won  become  Irrogular. 

{i  3s8.  The  etfects  of  deficient  arlcrialixation  on  ihc  viuomolor  »yst«m  are 
well  shown  when  in  a»  animal  placeil  under  a  moderate  doee  of  urari  so  aa 
to  eliminate  the  complications  due  to  contractions  of  the  skeletal  muaclea, 
with  both  vagi  divided  so  as  to  insure  the  elimination  of  inhibitory  impulsm 
from  th«  medulla,  artilicial  respiration  b  BUS|>endod.  8oon  after  the  raspita- 
tion  b  sIop{ied,  a  very  Urge  but  steady  rise  of  pressure  U  observed.  8ee  Fig. 
144.  The  rise  so  witnessed  b  very  nniitar  to  that  brought  about  by  power- 
(Ullv  stiniulslin;;  a  number  of  raso-coDstnolor  nervca :  and  there  can  be  no 
doubt  that  it  is  due  to  the  venous  blood  stimulating  the  vasomotor  oeatie  in 
iIm  medulla,  and  thus  cauniug  comtriolion  uf  the  small  arteries  of  the  biKly. 
eepecially  thune  of  the  splanchnic  area,  Mftce.  as  we  shall  see,  in  speaking  of 
the  skin,  a  too  ven^Mis  blood  leads  to  a  widening  of  the  eulaoeous  arteries. 
We  say  "stimulating  the  modulbiry  vasomotiir  oeutre,"  because,  thou'^h  we 
Lniausl  admit  that,  sinoe  n  rise  of  preaaure  follows  upmi  dyH^uxea  wheu  Dw 
'^ionl  cord  hai  been  proviouKly  divided  below  the  nietlulla,  the;  vuioiia  blood 
may  stimulate  Otlter  viuomotor  oenlns  in  the  vpinal  cord  and  punilily  even 
nrt  ilirvi'lly  un  local  ]>vriph«ral  nicchunlims,  yet  the  fact  that  the  rise  of 
pm^un-  io  much  Icm  uudiT  iImw,;  rircumslant^^  showv  (hat  the  nic<)ultary 
orntre  plays  tliv  chivf  jiart.  As  wc  have  just  said,  the  oflccl  of  this  vnso- 
eansiriditMi  in  raising  the  pr«Nure,  if  not  as«iste<l  hy  an  inerc«M,  ut  all 
vveiite.  is  iMt  neutrabxcd  by  an  ndeqiinto  ijetircaMi  of  the  cnnliao  slnrke. 
U|wj  the  ceaestioo  of  tW-  artilicial  r'^«|iimtion,  the  respiratory  undulations  of 
Courae  cease  also,  so  that   the  Iduod-pruMure  curve  rises  at  lirst  stMidily  la 


C04 


RKSPIRATtOX, 


olniott  A  sirKiulii  line  bn  k«ii  cnljr  hy  ibe  Lcart-beaU;  Tel  nflcr  a  wEiilc  nrw 
undulRliom,  iliv  no  culled  Truub<^  vr  Trmtibe-Horing  curvfc,  make  ilieir  ap> 
peanmcf  (l''iK-  ''''i  -•  ^)i  very  Himilnr  to  (he  previous  oii«e,  except  that  (heir 
curves  ara  larger  and  nfa  more  Htrcepinc  character.  These  new  umtulaliooa, 
siDce  they  npiicar  in  ihc  ab»ciicc  ol'  allthonicii.'  or  pulinooaiy  muveinents. 
pn»ive  or  nclivc,  and  are  witncraed  even  when  both  va^i  ar«  ciit,  miuil  be  of 
VBSonioiorial  origJD  ;  the  rhythmic  rise  must  be  due  to  a  rbvtbmic-  ctin- 
•triclion  of  the  tmnll  arlcrif^s,  and  ibii)  probably  is  cautMl  by  u  rbyibuiic 
di»cbar{;c  from  vasomotor  cenires,  and  («peciHlly  from  the  medullnry  vaao- 
tootur  ceolre.  The  undulations  are  maiulained  u»  long  us  the  blood- prciau re 
roDtinuea  to  rise.  With  the  iucrea»ing  venotiity  of  the  blm^l,  boirever,  Ixwh 
the  vaoomolor  centres  and  the  heart  become  eufei'btcti ;  the  undiilKtioiif  di«- 
iippcnr,  and  ibe  blood -pre^Mi re  ra)>tdly  *inl(». 

Pic  itt. 


mmmfh 


A 


-o^ 


A  - 


.  y  \   'JiAA/ V  \i  ^  y  \i  A  A  A'  s 


Oumi-nmn'ai  Ci'mvib  niniiini  ^  ei>««n»OK  at  Bkrathiko.  iTajn-Rf-llntni.  Cram  i 
nenmot  1,  ^>,  4^  y  %m  \t^r%l»iHitt^lixi<A  ftranctnc  Irinr  rotitlauou*  Inolur  faiinli>c  ilipnniM 
<f  >  prakmttd  iitovmlltin.  m  tlml  %h*  •vvcml  nittvt  it|iTM«ii1  mrmtlvr  U*gr*  «r  (|i«  •*>■«  exiMt- 
mml.  t^tb  curve  1i  plarcd  In  111  |in>pn  rnlllun  rIiUvt  Ih  llif  Ian  tlsv.  iitiifh,  l»!«r«  ■pMn.b 
onliuil;  *iiil  llI•L'^vluu•l^Bl, lUrUiiH  tnai  ite  liLaiic  ii| invDifd  Vj  I.iIie bloodpmnnwnNi la 
tUlem  :!,  iLiiiiil  I.  tint  MInnKiklii  In  Mufii.V  nimi  1  liulion  tMiiia  (wflol  wbvu  ■rUndiU  i«»|4iUhMi 
■attxJDg  ke|il  op.  snil  ibe  uiiiluliitliiru  vMhlc  siv  Ibow  I  lie  niiliitpof  iiblrb  hair  hwti  (Uicunadl 
ilw  t*|iu  ncritt*  buTlnit  bmii  cm  ibv  pulMilana  oil  ihc  nii?cnl  und  ilnc«ii  cf  ibc  Rndalatknit  do 
notdllltv.  n'b«n  lb*  uIIIIfI&I  miiinhtm  «iu  antiwiiilttl  thcw  undulklluii*  iltanxiiml.  M>d  Um 
bliic4-p(*aiite  irm  Mnidltjr  vbllp  ibe  bnn-lvad  bvcome  ■lou'iFr  ^oon.wtbniitn  lnrarvi>X.M« 
niKliiInUuiu  »fpaut4.  A  Ulllc  Ealcr  Ibe  Lluol^|JRHUfL■  n»  Mill  rlilns.Ulv  han^bnt*  tliil  ilaiinr. 
tnil  Ibe  Dii'liiUtlniit  illll  tnurr  uIivIdu-  'i-uii«  ni.  I^Utl  iiit*[  Iciirtu  I;  Uic  (rawin*  vu  ttlil  U^bo. 
bullhu  brnnibtali  «rK  quicker  ■nil  lhFUiid<il«tloii>niitli-r.  TIi»  pmaun  Ihpi)  br^faii  toMt  npldlf 
tttayti^.  iDd  nimliiiicd  lu  f*tl  umliiuiiii-  time  Uier  nnini'lkl  m|4miian  nu  mumtil 

We  may  here  incidentally  remark  thai  the  occurrence  of  long,  alow  iioda- 
Itlioni  i«  not  depciideni  on  ihe  rewatinn  of  the  reapiratnry  movcmenlt,  and 
on  nn  abnormally  vcnoiin  condition  of  the  blood.  They  are  poinetiiiieH 
(I-'ig.  M9)  tccu  in  nn  animal  whuM  hreatbiug  is  fairly  Dorinal.  We  need 
not  discitM  them  any  further  now,  and  haTS  introduced  them  chiefly  to 
illiMlrate  ibc  fact  that  the  v»i"im<itnr  nervuuB  ayalem  i»  apt  to  fall  into  a 
ciiOdiiion  of  rhythmic  activity.     It  hn»  been  atiggeatol  inat  the  Dormal 


RESPIBATORY    ITXDl'LATIOXS. 


506 


K'rnKiry  uiKliiliitioDB  may  b«  due  lo  a  rbylhtnic  I'lMf  und  Tnll  nl'  ilw 
ity  of  the  ntsomotor  centre,  syuclminouii,  lilco  ilmi  nf  the  cnnlio- 
inliibilorr  ceiitr«,  with  lli«  reeiiiratonr  movemt^iiu.  Thrm  aiii.  hovrvver.  li« 
iioiloubl  Ibm  the  r«&|iinit(irv  variuliuu*  in  lilcmil-piVKViitT  iiro  iliir  to  th« 
mci-tianiciil  comlitioiiii  ducuftKd  abuve,  «ii<l  ibRt  vnwiiiii>t>jr  intlueiic««  ihIit- 
v«i«  but  Utile  if  ftt  alt. 

no.  iM, 


«-iiB  CnTK  OP  i  IUriiit.  lin(<ni>iiD  ayi  a  ?ii>h|:V  Movmii  Si-iimcn.  ia  wow 

fnioamr*  wu  •tctcnicii  not  b;  niMntof  ■  inircniT  muiumdn.  but  lif  as  Iruinimciit  dnilir  to 
Ihm  w*  IdanUcitl  hIIIi  Fli-k'i  (prliiK  Vrioivnt^.i  latacli  bMTt-bcal  (bo  nimiird  ■nd  iloKDaiiil 
Mmt*  arg  rttf  cine  Inrf'bei,  biil  inn;  bv  Twll)'  •llilliisal^bin)  br  Ih*  brip  ot  a  IvnK  Tilt  nndalR- 
Uont  oT  lb*  ncM  ofd«i  kic  that  or  nvjilnilon.  Tbc  wider  luMi*  ■(«  (h«  Tnutic-Ilctfni  furia.  ut 
wUcb  Iwo  coniploie  cunn  nud  |»ttlni»  <•(  i«o  <nb»n  ate  ilionn,  Kicli  Tnubf-HnliiK  cnna 
(OMpAlH  ftbool  tiln*  [v>Filnl<irT  currm.  anil  rarh  n^iJuliuy  ciiiia  tUw  ihu  Mittf  nomber  of 
ItMrt-bnu. 

$  388.  The  f\inb«r  geticral  etle^rtn,  ^iniilnr  to  the  above,  on  the  vnacular 
eyslem  of  tletldeni  art«riiili;[alii>ii  of  [lii^  hlmn]  iimy  be  *lu<li«d  by  tftkJu^  k 
blood* preastt re  trnciiiK  fruni  the  oiiroiid  or  utht^r  Krlvry  of  uu  kiiiniAl  while 
the  iiilvrferviiw  with  rc?-|iinilioii  in  [Hi!>hi-<l  uti  lo  n  fntiil  a>phyxiu.  Diiriug 
the  fint  ami  Mvond  ntiigc-*  of  thit  nvfihyxiu  iht;  blood- prtvKutL-  rixcii  rapidly, 
allX)iiiii)C  a  iK-iKht  far  above  tlie  iioniml.  During  the  third  Mtagu  it  falla 
even  more  rapidly,  rrpiiMiii^  the  normal  aod  becoming  nil  ns  death  eiitiiie*. 
If  the  Hniii.al,  no  uran  having  been  ^ivc-n,  w  breathing  of  ilwif,  and  if,  aw 
uiually  in  thv  cute,  the  a«phyxm  is  brought  about  by  occlution  of  the  trachea, 
t>ii  that  the  mochanicnl  enecto  of  the  n^apirntorv  movements  arc  exag^rated 
by  the  air  Iwiitg  unabl<t  to  enter  the  ehcKl,  tlio  renpiratorr  undulntionR  of 
tfiu  prnoure-curve  due  to  the  n>echniiical  eaiiH-i>  diwuiwed  above  are.  Fs{ie- 
cially  during  ihi'  lirsl  stage,  eslennve,  abnipl,  and  irregular,  the  inspiratory 
movemenis  being  aecompanted  by  a  coti^pieiioii»  fall  of  pmsure.  When 
ibi;  niiimal  has  liceu  previoiibly  plac«d  under  iirari,  m  liiat  ibe  tcqiiratory 
impulses  cannot  nianitest  themselvc!)  by  anv  muscular  uiovemcots,  tbe  riw 
of  the  pmeure-curve.aswehnve  already  aaid,  i«  at  first  st«ady  and  unbroken, 
but  after  a  variable  [leriod  Traube's  curves  make  their  appearance.  As 
during  the  ihint  tila);e  the  pressure  Mnks,  ihe^e  undulations  poM  away. 

The  henrt-beau  are  at  Ural  somen  hat  (|uiekeued.  but  sjieedily  become  alow, 
at  the  san>e  time,  b«  we  have  seen.  Dot  notably  losing  force,  so  that  the  pnl^e- 
curves  ou  the  tracing  are  exceedingly  bold  and  sirikiog.  Bui  (he  bolduetB 
uf  the  curve  of  the  OMreury  manutueier  is,  it  mtat  be  reineniberM),  partly 
the  mere  resiill  of  the »lo«Deu  of  the  rliyihai ;  the  mercury  ha*  time  |o  fall 
largely  between  eaeb  Ino  heats.    *  Fig.  1 48,  8  niHl  4.)    Kveii  while  tlie  blood* 

[>retwire  it  Mnking,  and  when  the  eardiae  Mroke  is  now  certainly  livM-ning 
tl  yifffT,  the  «loinncM  of  the  cardiac  rhylhm  is  still  sufficient  to  maintain 
aomewhal  time  characters  of  the  curve.    Tlie  strolH-s  at  la»t,  however,  rapidly 


506  U£S1'1HATI0X. 

fkit  in  strength  and  became  irregular,  though  the  heart  continues  to  beat  fur 
some  seconds  after  the  reepiratory  movements  have  ceased. 

If  the  chest  of  an  animal  be  opened  under  artificial  respiration,  and 
asphyxia  brought  on  by  cessation  of  the  respiration,  it  will  be  seen  that  the 
heart  during  the  second  and  third  st^es  becomes  completely  eorged  with 
Tenous  blood,  all  the  cavities  as  well  as  the  large  veins  being  distended  to 
the  utmost.  If  the  heart  be  watched  to  the  close  of  the  events,  it  will  be 
seen  that  the  feebler  struk&i  which  come  on  toward  the  end  of  the  third  stage 
are  quite  unable  to  emjpty  its  cavities;  and  when  the  last  beat  haa  passed 
awBV  its  parts  are  still  choked  with  blood.  The  veins  spurt  out  when 
pricked ;  and  it  may  frequently  be  observed  that  the  beats  recommence 
when  the  over-distension  of  the  heart's  cavities  is  relieved  by  puncture  of 
the  great  vessels.  When  rigor  nwHU  sets  in  atler  death  by  asphyxia,  the 
lefl  aide  of  the  heart  is  more  or  less  emptied  of  its  contents ;  but  not  so  the 
right  side.  Hence,  in  an  ordinary  post-moitem  examination  in  cases  of 
death  by  asphyxia,  while  the  left  side  is  found  comparatively  empty,  the 
right  appears  gorged. 

These  various  phenomena  of  asphyxia  are  probably  brought  about  in  the 
follonisg  way : 

The  increasingly  venous  character  of  the  blood  augments  the  action  of  the 
vasomotor  centres,  both  the  medullary  centre  and  the  subsidiary  centres  in 
the  spinal  cord,  and  thus  leads  to  a  constriction  of  the  small  arteries,  espe- 
cially of  the  splanchnic  area.  This  is  the  chief  cause  of  the  markedly  m- 
creased  Wood  pressure ;  though  the  venous  blood  ma^r  possibly  also  aet 
directly  on  peripheral  vasomotor  mechanisms,  or,  what  is  more  likely,  may 
increase  the  peripheral  resistance  in  the  capillaritj  themselves,  since  there 
are  reasons  for  thinking  i,S  ISa)  that  venous  bloixl  rich  in  carbonic  add 
meets  with  more  friction,  and  pas.%$  lets  entity  through  the  capillaries  than 
does  blood  less  venous  in  character. 

This  increased  ptriphcral  resistance  and  the  high  blood-pressure  to  wbidi 
it  gives  rise,  while  tending  to  increase  the  distension  of  the  left  ventricle  and 
so  indirectly  helping  to  augment  the  force  of  the  heart's  beat,  soon  becomes 
a  direct  obstacle  to  the  heart  emptying  iUelf  of  its  contents.  On  the  other 
hand,  the  labored  respiratory  movements  favor  the  How  of  venous  blood 
toward  the  heart,  which  in  consi'qnence  becomes  more  and  more  full.  This 
repletion  is  moreover  assisted  by  the  marked  Infrequeucy  of  the  beats  which 
is  soon  developed.  This  in  turn  de(>enils  in  part  on  the  cardio  inhibitory 
centre  in  the  medulla  being  stimulated  by  the  venous  blood;  but, as  we 
have  previously  seen,  cannot  be  wholly  accounted  for  in  thi*  way.  The 
increased  resistance  in  front,  the  augmented  supply  from  behind,  and  the 
lung  pauses  between  the  strokes,  all  concur  in  disteuiilng  the  heart  more 
and  more. 

When  the  large  veins  have  become  full  of  blood,  the  inspiratory  move- 
ments can  no  longer  have  their  u^ual  eS'ect  in  faiililating  the  venous  flow 
into  the  right  auricle.  The  chief  effect  of  liie  chest  movement,  as  far  as  the 
circulation  is  concerned,  is  to  widen  and  so  to  increase  tlie  capacity  of  the 
pulmonary  vessels,  and  at  the  same  time  to  diminish  the  pressure  around  the 
lai^  arteries;  hence  the  marked  sinking  of  the  blond-pix-ssure  duruig  eacb 
inspiratory  movement. 

The  distension  of  the  cardiac  cavities,  at  first  favorable  to  the  heart-beat, 
as  it  increases  becomes  injurious;  and  the  cardiac  tiMucs  at\i'r  a  while  be- 
come enfeebled  by  the  action  of  the  venous  blotnl,  so  thiit  the  strokes  of  the 
heart  become  weaker  and  irregular. 

On  account  of  this  increasing  feebleness  of  the  heart's  bent,  ace  iiupanied 
by  more  or  less  irregularity,  the  blood -pressure,  in  spite  of  tlie  continued 


RESPIRATORY    CSDULAT10N8. 


B07 


> 


I 


I 


trtemi  eonairielion,  l>egins  to  fall,  stnc«  leu*  srid  lew  blond  U  pumped  iutn 
aneria)  system ;  the  iKilduaw  of  t)i«  ihiW curves  kI  tlib  «ag«  b  cliiefiy 
due  to  the  iiifrc<)u«iic_v  of  th«  AtmkeiL  Aa  the  (itmntily  which  pmMi  IW>in 
tite  liviiri  iiilo  ihu  arlcrieA  bcciiim  Iaw  m^iihI  Iiv  neci^ni),  the  pRMiire  geu 
lower  niiit  luiror,  th«  d«c«iit  Mag  nwij<lvil  hj  lU-  iixhutintjon  of  (he  vma- 
lOMitfr  centre,  until  idina«t  before  the  ImI  benln  it  bm  siiDk  Ui  zero.  Thiii  nt 
.  _.  oli»i'  of  M|)hvxiit,  while  the  h«iirl  and  venouit  B,vstotn  are  ditticndi-il  wUh 
blntxl,  the  nncniil  oyeUHD  ia  Ion  llinii  iinrmnlly  lull. 

S  390.  Whilo  chiutgM  occurring  primnnly  in  the  mpintory  emtem  tht» 
*H)(Cl  iht  YMCular  systeto,  eoiiv«ra«ly  i'hnng<m  oocurritig  primarily  in  the 
vncular  tyttem  nffoct  the  rcepimtory  sT0t«tu.  Tiro  kinds  of  change  in  (ho 
viix-iiliir  »yst«m  bearing  on  two  parts  of  the  respiratory  syMem  dcwrve 
Mpwial  altoDlion. 

lo  (h«  firet  place  the  rMpiratory  meohaDism  may  be  olfecied  by  changes 
in  the  blood-supplv  to  the  respiratory  centre  in  the  medulla.  We  have 
iilrctidy  Been  (|  373)  that  ibe  sudden  cuttinft  off  of  the  supjdy  of  blood  to 
the  ntedulia  gives  rise  to  dvspnivio  respiratory  movemenla  sn<l  may  lead  to 
expiratory  ranvulaiona.  'fhat  b  an  extreme  ooM;  but.  short  of  that,  the 
nctivitv  «f  the  re:ipiratory  centre,  the  exlonl  and  obaraoter  of  the  respimtorv 
esplijsioui  wbicli  take  pla«c  in  it,  may  1>e  varied  aoRonlinK  as  the  eonstricled 
or  dilated  omdili'Mi  of  tlitt  dmali  iirlerim  branching  otT  from  the  basilar 
artery  or  of  the  iMwilnr  artery  itM-lf  allows  a  scatily  or  a  full  flow  of  blood 
throui'h  the  mo'Iulla.  .Vnd  it  in  [HMiibU-  that  w>me  forma  of  dya]nu!ea  may 
be  brought  Altoiit  in  tbii>  war- 

Mnch  mure  ■■nmmon  and  iinporlant.  however,  iii  llu-  trctnd  kind  of  obangie, 
that  nlTeiTliiig  the  oir^'uliuion  Ibrough  lh«  hin^d.  In  liic  normnl  organism  an 
•derjnnte  nupjily  ol'  arlcrial  hloixl  to  the  ti»«iic«  is  sccurcil  by  an  adequate 
renewal  of  the  air  in  the  pulmonary  alveoli,  and  an  udoiuiitcly  rapid  flow  of 
blood  thMxifih  the  pnlmonnry  capilliiricK.  When,  as  by  ohstnietion  in  the 
ptilmonary  nrlerics,  or  by  failure  of  the  cardiac  valves,  or,  and  perhap  CMpo- 
cially,  by  an  inxutticivnc  canliac  stroke,  the  stream  of  blooil  from  the  lungs 
into  the  led  ventricle  is  lessened  either  in  amount  or  in  rapidity.  Ims  oxy^n 
is  carried  to  the  tisBues,  includint;  the  nervous  tissue  of  the  medulla,  and 
dyvpuoea  or"  want  of  breath"  follows.  When  the  circulation  through  the 
luDgs  b  in  full  healthy  swinn,  the  lucmo^lobin  "f  the  red  corpuscles  i«  ait  we 
have  seen  Mtiiiraicl  or  nearly  italurated  with  oxytj^ou.  [f  owing  to  a  slower 
•tream  the  red  corpuscles  tarry  longer  iu  their  ))«»a;{e  alon)-  the  walls  of  the 
pulmonary  alveuli  they  cannot  thereby  take  up  a  oonipensatin);  addition  of 
oxygen,  indrul.  It  l<  doubtful  if  they  can  take  up  any  additional  oxygen  nt 
all.  The  bl<MHl  fiillintr  under  these  cireuinstanoes  into  the  led  ventricle  and 
sent  tlienoc  over  the  Ixidy  b  not  more  arterial  than  tinml ;  at  the  i>niiie  time 
the  amount  of  bhxHl  tent  out  at  each  henri  .nroke  is  Itm,  oflen  mnch  Iws, 
than  the  mirrnal :  mid  tlto  mednlla  a*  n-ell  a->  the  Oliver  timHia  milTer  iu  cim- 
sat^uenre  fmm  a  dctiHeocT  of  oxyg^'n.  Thi<  deficient  supply  to  the  medulla 
manitWiw  ilvlf  in  dv^pncrtc  or  at  least  in  lali'ircd  tirentliing,  which  sometimes 
throng))  the  nifchaiiical  inrtiirnoi*  disciiwed  abuvr,  hn»t  the  happy  result  €)f 
imtirovini;  tho  pulmonary  dreuiatioii  and  m  prodnns  conipeitMting  erllbctai. 
Wnen  the  pulmonary  artery  if  xuddenly  plugged  with  a  clot  the  primary 
and  urgent  symptom  is  "  nant  of  breath,"  though  air  ■■4)i«rr«  frocty  into  the 
rliest :  and  "  canlia^'  dyspmea  "  is  a  common  symptom  of  canliac  disoaee. 

li  381.  Other  systems  of  the  bodv  are  also  re!»(e<l  to  the  rrapiralory  srs> 
t»m,  tl)oui;h  by  tiai  lees  slriltin;^  than  thow  which  bind  to  it  the  vascular 
svstem.  We  have  seen  that  delicient  nrterUlizstion  of  the  bloo'l  stir*  tip  the 
niu.tcltf  of  the  alimentary  canal  to  increased  activity,  and  we  shall  pivsently 


608 


RESriRATIOfr, 


Ki' 1  lint  till- runic<-oii<lit ion  Iirntn  DOtftMeHlect  in  )>roaiiiliiig  the  perspiratitw; 
it  prvbulily  bus  t>  similBr  iiifliiciKw<tverotJi«r  wcretioiko.  Uo  ibeoth«r  htatA, 
ss  we  hnvv  tvcn.  i  :174,  (here  are  r«afone  for  thinkinf;  ilial  ibe  ac-tivilv  of  ib« 
mpirnlory  Miilre  iiiid  *o  ibe  energy  of  ih«  whole  teapiraturj  act  is  inffncnnd 
by  chcmicnl  chmigcs,  oth^r  (hmi  tlw  <l«crew«  of  oxygcD  am)  invmiM.-  ur 
carbunic  ucid,  bnitigbi  about  iu  the  blood  by  the  activity  of  th«  alcrltul 
miuclee. 

The  cloeeiiecs  and  the  intrican'  of  the  ties  which  tlius  connect  thv  mtnin- 
tory  tysiem  niih  nhiio«l  all  perls  of  the-  Iniily  inuv  t)«  illuslmiol  bv  ouiuitlrr- 
io);  the  edects  of  muscular  work  on  the  body,  ami  the  «oiiditionH  nhich.  a|<nrt 
fn>m  tl»e  capa<-ily  of  l)ie  rouaclea  theinaelvn  aiu]  of  the  tnolur  ni-rvi>iiB  u|i|ia- 
ralus  which  jiuis  them  to  Hi>rk.  detcrniiiH-  ihr  ])oitfr  of  the  body  tu  do  worh. 
Duritt^  work.  CHficdally  urdiiout  work,  ihc  muMUlar  ooiiinictiuns  rob  lb* 
bluixl  III'  niiich  oxygen  and  luiul  it  with  much  carbuiiicucid.  Thie  rhunp 
ill  Ibf  blmid  nixild  itM-'lf  liirrciMtt  the  nciivily  of  ibe  rmpiratorr  centre  bdiI 
lb**  (iicrgy  of  the  rtvpirutor)'  niovcnicni*.  and  might  he  KiiflitiViit  to  securv 
euch  iin  incrcOM-  of  ihrwr  nrnvt'iurnttt,  ihiit  ihc  dcticitncy  of  osy^en  anil 
infTcnx'  i>f  nirhitiic  iii-iil  i>hould  never  ovrrctep  certain  limits.  Dul,  att  «e 
have  raid,  aj'pnmitly  olhcr  proditcis  of  rauectibr  nietaboliim  act  «<  jKitentJy 
in  Mimiihilini;  the  nvpiraUiry  centre,  that  th«  reepiralory  moveinenitt  are 
more  than  sufficient  lo  couipciuale  tbo  changes  id  the  gaeee  of  the  MiwmI. 
The  efficacy  of  the  angnicntcd  lespiraiory  niovenienie  is  much  iucrenM^I  bj 
B  cciicomilant  increase  iu  cardiac  activity  and  a  swifter  or  full«r  strrani  of 
blood  ihroiigh  tbe  lungs  :  indeed,  unless  hacked  up  by  the  cerdtnc  incrmve, 
the  mere  increase  of  the  puhnonary  veuiilaiiuD  might  prove  inad<^|unir. 

Hence  ihc  capacity  for  arduous  uiasculnr  labor  \s  determined  mil  by  the 
rtspiraKiry  inechanUm  alone,  nor  by  the  ra!>culaf  system  alon^,  bitt  by 
both,  snd  «^pcciatly  by  both  working  together  in  harmooy  and  concert 
Tbe  incrcamd  venlillaiioii  uuuld  he  idle  unless  it  neri-  accompanieil  by  a 
(|tii<'ker  circulation,  and  tUv  i]uickcr  circulation  would  i>iniilarly  Im-  of  com- 

turativt-ty  liltle  iih'  unkry  aciiimjiaiiici)  by  IncrraM'd  vcnlilalion.  To  a 
vttandrr  ihc  working  of  llic  tci-i>iraUiry  puinp  in  much  nKirv  obvious  than 
thai  of  Ihc  vascular  »yKl*ni.  sad  iijilnd  ihc  xuhjtci  himwlf  is  inucb  nxm- 
directly  ccnfcious  of  cliangi'i>  in  ihv  t(>rni<-r  thiin  of  cbnngi-s  in  ibc  latter. 
Hriice  «hen  the  orgsnimi  <di«i'x  to  he  able  lo  ricW  tbe  demands  nhicb  ibe 
labor  is  making  upon  it,  the  subjfct  is  said  lo  he  "  out  of  breath."  tht>U|;h  ID 
a  large  number  of  cases  (he  lailurc  lifs  much  more  at  the  door  of  ilie  v»- 
cutar  than  of  the  respiratory  system.  And,  as  a  rule,  it  may  perba|H  be 
said  that  Hbtn  two  men  diflcr  in  their  capacity  for  strenuous  nork,  such  as 
tunniiijf  a  race,  the  ditlereiice,  ihuugh  it  is  oOeii  familiarly  spoken  of  aa  one 
of"  wind  "  or  power  of  hreaihing.  i»  in  reality  not  a  dillerence  in  venlilaling 
capacily  but  a  ilitfertnce  in  the  power  of  ilie  heart  lo  keep  up  lo  and  wora 
in  haimtiiy  wiib  the  tncreated  letpiiatoiy  niuvtmeiiiii. 

Thus  there  ere  two  main  factors  in  re«piraiion.  ihe  mtpiralorr  mecbaobtn 
proper,  and  llie  circulation,  the  <<iie  hnnjiini:  the  air  to  ihit  blood,  and  ibt 
other  the  bidod  lo  (he  air.  W«  may  remind  ihe  rc-udcr  ihat  llK're  ■  n\*n  a 
third  factor,  nnd  (hat  me  of  urenl  moment,  the  amount  of  hirmogloMn,  that 
ia,  (he  nnnibcr  of  rtd  tdrpniiclis,  in  ihc  bkod.  The  anioiint  «f  oxygen  taken 
Up  frcni  the  Inneti  depends  iiot  inlv  on  ihc  stroke*  ol'thc  n«pirat«ry  and  the 
varculnr  {'.uiii)s  hut  aho  en  ihc  riclintss  of  the  htrod  in  reti  corpuscles.  A 
b<<ly  wbiih  licm  Irss  of  bleed  cr  fmm  disease  is  ansrmic  is  thrown  out  of 
breaib  by  very  slight  exeiticn,  not  'o  much  bccauH  the  respiratory  or  t)ie 
vascular  ptimi)  ia  week,  hut  because,  through  lack  of  oxygen  carriers,  with 
their  be»l  cdona  ihe  combined   pumps  can  only  deliver  to  Ihe  tisaucs, 


RKSPIKATORV    MuVCMKNTfl. 


fi09 


Hluiinp  th«  iti«tlull«,KD  inftdequatenippl)' of  oxj-|{eii.  Aod  ftii  psrsoiu, 
■Kit  tt'itr  of  bictawlobiii  io  proportion  to  tbeir  body  wi-t);hi  i»  aln-a^r^ 
^«  jmr.  sK  proverbiall]-  "  scant  of  breath." 


MoblFtED    RrariBATORY    MoVEUEKTS. 

i  998.  Tbv  roHpiratory  Rii^nfliantMii  with  its  ndjiincl*.  in  nddiiioa  to  lla 

'Hptntorr  fuortion,  bccomitt  uf  aen'icv,  ivipccinllr  in  tlio  nue  of  iiuui,  hh  a 

ikratBa  iif  rs|>mwing  rmotioii*.     The  rnpinttiiry  ciiliimii  uf  nir,  moreover,  ia 

■I*   uit  from  (Iw  cbmt,  t>  rmjin-nlly  iiinilc  um:  of  ia  a  meduinicul  veay  to 

J^pvl  bodka  from  tlir  upfMrr  nir-piiMMif^w.     Hcncn  ariM  a  number  of  iiccu- 

Q*ri*  Diixlificd  anti  mure  or  Ivw  coniplicntt^l  r(W|>initon-  niovenieoia.  tighiiu;, 

Bpu^iDg.  laugktrr,  rlc,  adaptiKl  to  Mciirespvcia)  ends  wbicli  aro  not  dw- 

'Xifilr  rcKpiratory.    Thoy  am  nil  cneDtiallr  ntfltrx  in  ohamcl«r,  the  alimulitt 

'^vtrmiiRioK  Mcb  movcmeDt,  snnKtimm  affecting  a  pcripberal  uflVrvtil  nerve 

*^  ia  tW  i-aae  of  cou^'hing.  fnnirtiinee  workiog  thmut;b  the  hijcbur  piirta  of 

'•M>  braiu  At  ia  laughter  and  trying,  KDnictimm  powiblv,  lu  in  yuvrning  nnd 

*^li)Dg,  acting  oD  the  respiratory  ce«ilre  ileclf.     Like  llie  simpk  mpirntory 

^ct,  tlMT  inaT  with  more  or  loss  Buooess  be  carried  out  br  u  direct  elf ^rt  of 

M<;Ain<7  U  a  deep  and  lonx-drairn  insplniiion,  chiefly  through  tbe  ncwe, 
follownl  hy  a  somewhat  slioner,  but  correspondingly  large  eipiralion. 

VaicNiiiy  iJt  (iinilarly  a  d«ep  iii»pinillon.deo|>erAn(l  long«rCi>ntiniied  than 
^  alKh.  drawn  ibruugb  tbe  widely  ojieu  tuuiith.  and  acornnpanled  by  a 
fxculiar  deprtmlon  of  tbe  lower  jaw  and  fre<|uent[y  Ity  an  elevation  of  the 
•bouMrrv. 

Bteemiyk  coiicisI«  in  a  Nudden  in.->pinitor^'  contrnotion  or  tlto  diaphragiu,  in 

VW  nmne  of  wbidi  the  glottic  soddi'idy  eloeot,  so  thai  the  further  enlraDoe 

I   *>(  air  into  the  chest  is  preveiiliil.  while  the  impulse  of  the  column  of  air 

joat  votrrinit,  as  it  strikM  upon  tbe  closed  glottis,  sir  as  rise  to  a  woll-knnwn 

MMMapanyinK  sound.    The  aflerent  impanm  of  Ine  reflax  act  arc  conreyod 

b<r  tlw  gaMric  branches  of  the  vagin.    The  closun  of  the  glottis  ia  carried 

oat  hr  nsana  of  the  inferior  laryni^al  nerve.     See  Voitv. 

Id  soAl^ia^  a  series  of  «imilnr  convulsive  insniralioua  follow  each  other 
rinwlr.  the  glottia  being  closed  earlier  ihitn  in  the  ciue  of  hiccough,  so  that 
L     Kula'iv  DO  air  enter*  into  tl>«  chest. 

f         Qniflting  consists  in  the  first  place  of  a  deejt  and  l-iugdrawi)  iii»{>lniliou 

br  which  ine  lungv  are  welMilled  with  air.     This  i^  fidlowinl  by  n  complete 

eliMurv  of  the  gtiiiti».  nud  llit-n  comes  a  ludd^ii  nod  forcible  cxptriition,  in 

lie  mirlst  of  which  the  glottis  suddenly  ii{i«iiii,  and  thu»  a  hliiM  of  air  is 

drfna  through  the  upjier  reapinUory  |ia»rax<*t.     The  afl«n-nl  impulses  of 

Uiia  rvfWx  act  are.  in  most  caaai,  as  when  a  foKiiri  IrMily  it  lodged  io  the 

luyax  or  by  the  side  of  the  epiglottis,  cotireyed  l>y  the  ftuperior  laryngeal 

nerve:  but  iIm- morenient  may  arise  from  rilmiili  applied  to  other  aShrent 

branches  of  the  vagas,  such  as  thuw  xupplyiug  the  broachial  pas!ag«s  and 

•bNnacb  and  tbe  auricular  branch  di.itributcti  to  the  fnfilu*  Ktlemtt*.   Sliinu- 

latloo  of  oiher  nurvce  also,  sucli  a<  tliosv  nf  the  skin  by  a  ilraught  of  cold 

^r.  mar  develop  a  cough. 

t-  ■■■--■■■iti  the  general  mnrvnipnl  is  r>ventia11r  the  some,  except  that  llie 

[    •>;  m  the  pharyiix  into  tbe  mouth  is  cloMd  by  the  conlraciion  of  the 

anc-M'  r  j>illars  of  the  faucw  and  the  <Uc'ccnt  of  tlie  soft  [Mlate.  so  that  the 

force  of  the  blnst  is  driren  entirely  through  tbi'  now.     The  afferetit  impulsea 

hen  mually  come  fium  iIh-  iwmI  hrancbM  »f  the  fifth.     When  meexing, 


510  RESFI&ATIOX. 

however,  ia  produced  by  a  bright  light,  the  optic  nerve  would  seen 
the  afferent  nerve. 

Ijaughing  consists  essentiully  in  an  inapiratioQ  succeeded,  not  by  < 
br  a  whole  series,  oflen  long  continued,  of  short  spasmodic  espiratii 
glottis  being  freely  0}>en  during  the  whole  time,  and  (he  vocal  cord 
thrown  into  characteristic  vibratione. 

Iq  crying,  the  respiratory  movements  are  modilied  in  the  same  wa 
laughing;  the  rhytnm  and  the  accompanj^ing  facial  expressions  ai 
ever,  different,  though  laughing  and  crying  frequently  become  ii 
guishable. 


CHAPTER  III. 


THE  KI.IMIXATJON  OF  WASTE  PRODUCTS. 


,S  393.  Wk  have  Uaewl  the  foot!  from  ih«  alim^Dtarv  c«niil  into  the  blood, 
antl.  ilitl  the  8l*t«  of  our  knowle<ige  (>erniit.  the  italurAl  couree  of  our  slmiy 
nould  be  lo  iraoe  the  food  from  t)i«  blood  iuto  the  tissues,  ami  then  to  follow 
the  products  of  th«  actiTity  of  the  tissues  back  into  the  blood  and  so  out 
of  iDe  body.  This,  however,  we  eanoot  as  vet  salii-faciorilv  du ;  and  it  uill 
be  more  ronvenieut  to  Mwly  ^ri>t  the  final  produclji  nf  ifie  metabolism  of 
Ihe  body,  ai>d  the  manner  in  whii>h  tbey  are  eliiuiiiHled,  and  afterward  to 
return  to  the  discussion  of  tbe  inli-rveniiiu;  iilC[ni. 

Our  food  on^isls  of  certain  fiKHl-atnfhi,  vix„  ]1^>leidll,  fam,  and  rarlioliy- 
dndea,  of  various  salts,  and  of  ttntcr.  Id  their  iiiimagu  through  the  blnod 
and  tinuea  of  the  body,  the  |in>iei<K  faCn  and  i-arbuhTdratt-ai  un-  c-oiiv4-rt(T(] 
ioto  urm  (or  sonie  cluwly  alhed  Ixnty),  cnrlxinic  ncid  aod  water,  tlx:  nitrovrn 
of  tbe  urai  btiiij;  rtiniii.hi.-d  by  the  iintteklt  alon«.  Muny  of  the  ]>r«l«idM 
OOOMin  Hllphiir,  mid  uli«>  huv«  jdioKphoniK  iitucht<l  to  thvm  in  »oni«  oiimhi- 
DAtlon  or  other,  ami  Mime  of  l!i<!  (ul*.  talcfii  n»  food  contain  pbospborus; 
ibtae  tWn»atr  iiUimniily  undergo  oxidation  into  phoophatn  nnil  snlphatM, 
nod  leave  Ibc  body  in  ibnt  form  in  company  with  tbti  other  »ii!t». 

Broadly  i^[M-ulcing  ihi-ii,  the  waMc  proiluctc  «f  tbe  luiininl  cronomy  are 
iirm,  mrtwniG  Mcid,  null:*  and  wnter.  Thr«u  It-avv  the  body  by  one  or  other 
of  (liroo  oiniu  cbiiniicK  the  Inngv,  the  skin,  and  the  kidney.  Sinie  piart.  it 
is  Inn'.  leiivei"  tlw  bwly  by  the  bowel*,  for.  an  wc  have  peon,  the  feces  eon- 
tiin,  Itroiileii  nodigntrd  porlions  of  food,  substances  which  have  t>ei-R 
BMrcftd  into  the  bowel,  and  are.  iherefore,  waKlo  prudiiet«  ;  hut  the  amoutit 
of  lhi«c  ia  so  small  that  thcv  Rwy  bo  neglected. 

The  luncB  Dcrve  ii#  the  cfuinnci  for  the  d>ichu;ge  of  the  greater  part  of 
th«  carbonic  acid,  and  a  cmmderable  ijuantitr  of  water ;  this  discharge  we 
buve  JHst  sludifd.  Though  tli«  akin  there  lenvc  llic  body  a  oumpnralively 
small  <|uantity  of  mIis,  a  liltle  carhouic  add,  and  a  variable  but  on  tbe 
whole  large  luantiiy  of  water. 

Tbe  kidneys  discharge  nil  or  nearly  all  the  urea  and  allied  bodies,  the 
tcrealer  portion  of  the  salts,  and  a  Ur^e  amount  of  water,  with  an  iiu-igniti- 
cant  quantity  of  carbonic  acid.  They  are  nefiecially  important  since  by 
them  practically  all  the  nitrogenous  waste  leaves  tbe  body,  and  to  tiient  we 
will  turn  tirst. 

Tbe  Btrvctobe  op  tbe  Kidxby. 

^  384.  Th«  kidney  ia  a  secreting  gland  constructed  upon  the  geoerd  pka 
of  a  <'<>ni|Hiund  M-erelJng  glaud,  but  ixMseasin^  special  features.  Tbe  eecret- 
ing  [M>rlion«,  in  nbicb  the  divisimui  of  the  main  duct  or  untfr  end,  are  not 
relatively  »Iiot1  tnben  with  branchings  or  lateml  bul|<ings,  that  is  to  say,  are 
not  alveoli,  bnl  are  cxlreinely  long  narrow  ttibtdes,  will)  no  branchings  or 
lateral  bulging*.  The  whole  Ixiily  ef  the  kidney  is  made  up  of  tlieae  oon- 
lililuent  tiibultn,  uriuiferou*  lubles,  tubuli  ttrinifiri,  closely  packed  together 


'the    Ki,IMIXATH 


[no.  ISC 


with  iuftt  Its  much  C')niii?clit-e-tiBsiif>  as  is  sufficient  lo  oirr;  s  l>rg«  < 
blDoaveeaeU,  a  certaiu  Dumber  of  iTmptiatiire,  and  ucrves. 

Kach  uriniferoua  tubule,  consisting;  nf  a  single  layer  of  epithelium  rnttiD); 
OB  B  basement  membrane  which  over  the  ^ren[  jiart  uf  the  leu^h  of  tW 
tubule  is  couapicuous  and  diniuct.  bej^-ins  in  a  peculiar  i^iruclunr  called  a 
Malpigliian  i-Hiiaule,  and  fjr  tlie  fim  part  of  its  course  puiitues  a  path  ithi^^b 
U,  uii  the  vrbole,  very  tn  luted  and  dt^cioua,  diirlDK  winch  ic  may,  for  ifae 
prawnt,  be  spoken  of  tu  a  ini:4tL-d  tubule,  correspoiiditijc  t-i  the  tubuliu  mm- 
b>rtui  of  old  writers.  U  Mul>»e()uenlly  tukeri  n  inun;  Mrai^ht  courM,  aud  u 
then  called  a  Atruight  tubule,  fu&u/iu  ir^fiui.     At  tu  l>eginning  and  duriii|f 

it«  tvr  luted  cotirM!,  thv  tubulo  li<si,  f>>r  ibe  laoBt, 
neur  llu>  Furfacv  nf  the  kidney,  farmiuff  tlie 
nuiiu   part  of  the  enrfrir  of  the  kidner  {Fis. 
ir>()].     During    Ita    vtnttght    iiiunK    it    rum 
lovrnrd  tlw  dcrpw  parlK,  ponvi-rgiug  lavanl 
Ihc  Conciive  border  or  bilut  of  the  kidocr 
where  iho  ninin  duel  or  ureter  tuttm  :  the 
couverciiiertraiuhi  tuhiilc*  forming  together 
tin-  mrJidii  of  tlic  kidney.     While  ptiniitn^ 
Ihr-   lirsl    twisted  and    devious   part  of  tbrii- 
coiirac.   during   the   gnater    put   of  whichj 
as  vm  nhnll  see  they  [mmsosb  marked  t«cre — 
tor)'  chAniclers,  the  iubulee  do  not  join  «afh 
other.     Diiritig   the    latter  siraight     part   ct^::^^ 
ihdrcourae,  when  lu  ue  sliall  k«  tlteir  char— —^i^ 
Rclere  are  thr«c  of  conducling  rather    thaiEr.^  to 
of   secreting    tubulcx,    ihev    repeatedly  joia 
A  fler  each  junction  the  tuWle,  though  wide 
thau,^h  of  the  two  tubulee  which  JMOed 
form  it^occupies  1cm  spiice    than   ifae  ti 
toother;  Bimce  the  inedullary  suhtiAnc*  be^' 
conui  l«M  af  it  convergai  lonard  l)i<-  hihi»< 
The    medulla    is,  morvoTer,  divided    inio  r  k        > 
number  (varvlng  in  dilfi-rcnt  nniniaU,  brin)t^  ^*f 
(>ne  in  the  rabbit  ami  the  ral,  ntwl  about  lur  ^  ^ 
or  twelve  in  man)  of  uiaives.  rnch  of  which    '' •^ 
»iiiei>  it  diminiuhe*  in  hulk  toward  the  hiluk  ^5*"^ 
hiw  lh<'  form  iif  a  jiynunid.  i<jri^Mi</  of  J/a/— '^'" 
}Hghi,  with  its  Kpcn  direci^id  nidinlly  toward  the  hilus  ami  its  linso  nstin^^^? 
on  and  becoming  cimfuscd  w'nh  thf  cortex. 

The  iirrttr  or  nuiin  iliicl  of  the  kidney  when  traced  to  llie  kidney  te  found 
to  expand  al  tlw  hihis  into  n  fllunel-^hnpn)  irtivity,  the  prlri*.  which  divide 
ur  branches  somewhat  irregularly  into  a  number  (equal  to  thiti  «f  the  pyra- 
mids) of  ehort,  broad  luW,  niAjeff.  somvirhnt  in  the  way  that  the  htiuil  uf  a. 
{(love  divides  into  the  tingore,  but  more  irregularly.     Into  cadi  cnlvx  ih^ 
summit  of  a  corresponding  pyramid  projects  fur  some  little  way  in  ihe  form 
of  a  nipple,  or  ;>i;>iV/a,  the  epithelium  lining  (he  calyx  bein^  thus  cmitiuuoua 
with  and,  OH  it  were,  relleeted  to  form  the  eiiiihelium  ciivering  the  projecting 
nipple  of  the  pvrainid.    llie  straight  tuhuW  forining.  aa  we  have  seen,  the 
pyramid,  thougli  nunicrous  at  its  base,  become  by  Te]>eated  juQctlun^  fewer 
and  larger,  and  tlually  form  a  nutulier  (in  mau  about  a  score)  uf  relatively 
wide  tu1iul«a  which  a|ieu  into  the  calyx  at  or  near  the  vety  tunimil  of  the 
nipple :  here  tlie  epithelium  lining  the  tubule*  hccoino  coniiauoiu  with  ihe 
epithelium  covering  tlic  papilla. 

Heuce,  in  a  mdical  »ectioa  of  hunuui  kidney  (one  taken  io  the  long  txU 


Sacao*  Til  Rill  an  tik  Kuocet. 

SIMVnM  Tir(  MEI'l't-LUTY  j>u  Ojk- 
TIKtU  ttoKCW*.  A.1U  TUB  BoilWIISi 

ornit  Vnnni   lUuiixj 

n.  unl«r  :  b,  ■■rlviioruiauieMrif. 
(•pUIiE  lutnunile'l  t/j  oillm  "I  tho 
•avivlatT  lube;  <l.  [lylnmlilikl  pat- 
tlDnt  -,  t.  nrilMl  ]«nl(iii  of  i>w  kld- 
u«j.j 


THE   STRfCTCBE    OF  THE   KIDXKV, 


I 


I 
I 

I 

I 
I 


htina  iirffrtaMt},  lli(>  wlioli-  imter  |H>riiitu  of  t)i(^  orgiin.  ii)l  iVMini]  vxi-cpt  at 
the  hilu.*.  Hill  Iw  ««n  t"  be  uctupiffi  liy  tin-  fairly  uniform  cortex,  which, 
being  wmpodwl,  ii»  w«  h«vc  Miiil,  tnninly  (if  iuIms  l«ii>iiii^  in  (it)  dirMtious. 

EreMOU  f»i  »ecliop  lo  lh<:  iiiikrtl  eve  n  gniniilar  iinpect.  From  this  cortex  will 
It  **en  oonrerfriiig  tuwiinl  the  h^ihi*  fl  rerluin  number  of  pyramids,  each  of 
which)  Muc«  it  i«  niuiiily  oomDufcil  of  ndinting  itraieht  lubules.  imd  since 
iho  minulo  bl<x>dvriwel«  minifjring  ia  it  hitrc  a  Mtuilnr  radiiuiiig  Blrai^ht 
cour«o,  will  pmetit  (u  I  he  niikf<l  vyo  n  more  or  Imh  marked  radiating  t*rain 
or  striatiun.  Tli«np6X  of  riirh  pyrnmid  whcrctbc  scclion  has  paased  tliroutt'i 
lh«  apox  will  bo  SMti  projecling  into  its  approprialc  cnlrx.  the  calyc«a  will 
bo  t«ea  uoitiDg  lo  form  the  p<^lvis.  and  provided  that  the  plane  of  seel  ton 
hu  jMiwed  ifarough  the  mouth  of  the  ureter,  the  pelvis  »iU  be  seen  narmw- 
ing  into  the  ureter.  ITw  section  may,  of  course,  have  miaud  tlie  urotcr :  it 
ia  also  very  likely  to  have  cut  one  or  other  of  the  pyramids  higher  up  than 
the  HtlKchiueut  of  tl>e  calyx,  in  which  case  of  course  the  prctjectJon  of  lh« 
pMpilla  of  the  pyramid  into  its  calyx  ia  uut  seen. 

Jhfi  pyramidi  are  teparnled  from  each  other  Uiterally  ulx^ve  the  nttacb- 
mi-nt  of  their  reHpeetive  caljcea  partly  by  a  small  ijimntily  of  cortical  "uh- 
sKiimr  which  creep*  down  their  udes  toward  the  pelvis  (coliimnit  c.f  Bcrtiiii), 
anil  rIko  by  the  larger  branches  of  the  bloodvesacls  which,  lying  uut.iiile  the 

GIvis  and'  dividing  as  it  divides,  plunge  intu  the  milMiancc  of  Ihn  kidney 
twe«u  lh«  aily<^^  and  •»  between  the  pvraiuidK.  and  then  run  otitwunl 
loirard  iho  junction  of  the  cortex  and  meduflii  to  be  di»lril>iitod  it)  a  mnntier 
which  we  shall  d<*cribe  oremnlly.  Tlie  kidney  it  really,  m  »ecn  in  tho 
embryo  kidney  of  man  and  indicatoil  by  the  adult  kidney  of  some  nntmnls, 
Cfvnipuaed  of  lobes,  each  lobe  consiitting  of  a  more  central  metluila  in  the 
form  of  a  pyramid.  covcfkI  i-«[>vcially  at  ito  huse,  hut  also  to  n  oerlwin  extent 
nt  the  sides  by  cortex,  and  opening  at  iln  ap-x  into  an  appropriate  divi»on 
of  the  uMer.  As  in  other  elandif,  the  larger  hmnches  of  the  bloodvenels 
run  in  the  connective  ti«>u«  joining  the  lohe*  together,  and  paas  tlienoe  into 
the  lobce.  In  tli«  adult  kidney  the  lobes  have  become  more  or  lets  fused 
MMlher.  In  the  cortex  the  fu-ion  in  complete,  but  the  pynunids  Blill  uiain- 
tiiiD  the  medulla  in  a  iobcd  condition,  wparatrd.  however,  laterally  by  noth- 
ing more  than  by  bloodvc6Mle,  with  the  connective  tissue  carrying  them, 
nnd  n  n'mnant  of  cortical  Kubelnnce.  The  surfncc  of  the  kidney,  save  iti 
abnormal  cases,  ibows  no  indicniione  of  division  into  lobes;  the  uniform 
level  i)f  ihc  cortex  is  bounded  by  a  capsule  of  connective  tiaiue,  which  may 
b«  easily  tttrippcd  off  from  the  cortical  substauce  below,  and  which  at  tlio 
hilus  is  contmuoufl  with  the  connective  tissue  suntiunding  and  binding 
together  the  ureter,  renal  vessels,  and  mial  nen'es.  A  quantity  of  adi|>oM) 
liss(i£  not  infn^nently  turrounds  ihe  kidney,  being  especially  nbumbtnc  at 
the  hilus. 

i  386.  I-'ach  tubule  begins,  as  we  have  ssid,  in  a  Malpighian  capmlo 

tFig.  ir>l]  somewhere  in  the  cortex,  either  near  the  cnpxule  or  nor  tbe 
ase  of  a  pyramid,  or  at  Home  intermediate  level.  From  thenoc  it  runs,  we 
have  also  said,  first  aHatwtMed  tuhuleandsubeequeatlyaa  a  Mtrnight  tnbule; 
but  in  the  Bret  part  of  iio  coui«e  its  path  is  so  peculiar  that  the  word  twisted 
does  Dot  Bccnnilelv  <le»cril>c  it,  Sloreover,  t!ie  cbamcu-nt  of  the  tubule 
dianite  BO  markoUy  nt  varioiiii  parin  of  its>  course,  and  thotc  chnnges  are 
pnihably  of  Bu<-h  great  itii)»ir(Hnce  that  a  desi-ri]>tIon  of  tiie  liibulc  at  stio- 
iH.>wive  steps  of  its  jirogn*!'  along  its  whole  length  bet'oncs  advixabte,  though 
we  at  present  do  not  nndemtaml  the  meaning  of  the  varioun  changw.  Afl 
we  Kball  see,  some  of  thcMt  complt-x  ptruliarilicn  of  the  mammalian  kidoejr 
uv  partly  explained  by  the  stTuetnrw  of  the  kidney  of  one  of  the  lower 

33 


bU 


TUB    KLIMIXATIOX    Of    WASTG   rRODUCTS. 


BmniuK  tudi  lu  a  frog.     Il  will  be  conv«nieul  lo  dnoribe  flntaome  dcMili 
of  th«  |£uiii-nil  cciune  iiii<l  U)  study  tbo  changes  in  (.■hftra>-|<-'r  »iilMM|UuiitU. 

Lenvmg  tlic  ai{<iiul<}  tbu  tubule  fornm  id  the  iiciglibunug  ntrlC'S  •evvnil 
Hlmrp  but  roiinilcti  luriix.  kucI  in  ihia  jMrt  of  it»  coune  is  vcrr  ili>tiuclly  i 
tirislAd,  coDturted,  oonvoluteii  lubule.     It  ih^ii,  ccuiiig  to  bo  ifUlinetly  wa 


[Pio.  lu 


inuiiiAK  vr  TiiK  Uui'ut  or  Thu  tTniMrcituiv  Tiui'Mki 

A.  tonux :  B.  tiMiivtio  due :  V,  iai^Uut  omm  <^  <'>'>  looliiUi :  a.  n',  •ui«rtkf»l  uid  4iv|i  l»TMt 
tifrarMi  ftM  rtniD  rloiuorull,) 

voliilcil,  tiikcs  on  a  waryurgMillvNpirnl  ur  Komotinua  almocl  tflrai^flit  cuurtt, 
iKJng  diroctol  mdiiillv  tonnrd  tlic  tuodulla.  In  Uiu  j»trl  of  ita  couree  It  u 
spoken  of  as  then>irn)  tubule.  Still  couliDuiag  its  nidial  course, tbe  lubulo, 
Buddeiilv  diininisniiig  ven-  mudi  iu  widtb,  passes  on  f<>r  some  dUUiDce  right 
doirn  into  ihp  p.vraitiid  b(>tcin-  uniil,  ut  n  level  which  differ'*  wilb  the  difRireal 
tubiilc«,  b>]l  is  alwuye  iit  ^^nie  di«tanoc  from  ibe  n|>ex  of  the  ]>Tramii),  th 
tubule  betide  Bbarply  round  nnd  pur«iM»  a  bncknard,  nearly  siraighl  eour 


TIIR  aTRUCTUBE  OF  Tl 


610 


» 


I 


I 
I 


I 


lU  former  oiic,  until  it  fimlH  itself  huc-k  ngiiiii  in  lh<-  cnn^x  nt 
nee  fmm  tlio  iiKfliilln ;  iho  lulmir,  in  fnct,  in  contiuimtion  ul'  tlic 
spiral  MgniMil,  miikn  u  I'lop,  Ihr  /fiji  of  Iltn/r,  dipping  down  iiilo  tlio  niedulla 
for  n  Kfinii)  distaticc.  nnit  (-oniiMin^  i>l'  n  ilricrniliay  and  un  a*r*n>i'iHg  timb, 
bolh  of  tlMrm  niiiiiing  ■  riutial  itnirsc,  which  is  Mraighl  or  nviirly  t«.  The 
dMcendin);  limit  i»,  n«  w  )mv«  wtid.  very  narrow,  but  either  before  it  inakea 
the  iMrud,  or  jiixt  nt  the  bend,  or  at  some  liltlc  distanoe  beyoitd  the  bend, 
«h«)  it  has  nlmdy  bpcom«  thv  n«cending  limb,  it  ealjirgtH  Romeirbat  and 
cliHnt;i?»  in  chiirador,  thongh  not  renching  the  diameter  of  the  H{tiral  or  oon- 
voluli-'d  tiibtile.  Having  rosched  eome  part  or  other  of  the  cortex  in  a  more 
or  lens  strHight  mdini  lioe,  the  aacending  limb  of  the  loop  of  Henle  ehanites 
again  in  characler,  becuraes  atill  nider,  nud  runa  in  the  cortex  a  once  more 
diatiuclly  twisted  fourse;  the  twista.  however,  are  not  roiliKl  but  aiiKulnr, 
jtivioff  the  tubule  a  sigiag  apiwaranee :  hence  this  portion  of  the  tubule  is 
called  the  zifraiK  or  sotnetinies  the  i\regular  tubule.  Very  soon,  however, 
the  turns  of  the  lubole  become  rounded,  atid  the  tubule,  still  running  iu  the 
Ctftex,  aaaumes  chamclera  almoit  identical  with  thoav  of  the  initial  convo- 
luted ]>orUou  :  it  now  receives  the  name  of  tlie  »t«<Md  murol'ilfd  tubule. 
After  several  turns  of  thij«  kin<j.  all  confined  to  the  cortex,  the  tubule  once 
mure  chang^e^  in  dninicttT.  and,  running  u  «eci>nd  lime  in  a  *tTaighl  radial 
courw  toward  the  Ma-ilulhi,  bui^iimcit  a  m//Minf/ tnhulv  piinuing  a  straight 
rndiai  eunrte  diieclC'l  toward  the  apex  of  tlir  pyramid.  The  collecting 
luhulc,  joining  other  collecting  tubule*  and  clinnginL'  olighlly  in  charai'tcr, 
while  by  ro[Ma(4!d  junclioni  beoomiDg  larger, '»  continued  lu  a  durhaiy/lny 
tubule,  which,  joining  other  tubule*  kk  it  jMiwn  toward  the  npcx  of  the  pyni- 
mida,  oponti  at  InMt  into  a  calyx  at  or  near  the  summit  of  the  papilla  'if  the 
pyramid. 

Thus  each  tulHiU-  starting  from  a  Matpighinn  capsule  becomes  in  buccks- 
eion  a  first  convohttml  tubule,  a  i>jiiml  tuuule.  a  descending  and  iiaoending 
limb  of  a  lix>]t  of  Henle,  a  xigIl^;  or  irregular  tubule,  a  second  convoluted 
tubule,  a  collecting  tubule,  and  tSnallv  a  di»char)^ng  tubule.  The  diKhnrg- 
ing  portion,  the  lower  part  of  the  <'o]lcetiDg  portioo,  and  some  part  or  other 
of  tne  loop  of  Henle  he  in  the  medulla  and  forni  part  of  one  or  other  of  the 
pyramids.  In  all  the  rest  of  its  course  the  luhule  lies  in  the  cortex  ;  but 
from  what  has  been  snid  it  is  obvious  that  the  itart  of  the  tubule  contin>-d  to 
the  cortex  can  not  be  called,  alon;;  the  whole  len^'th  of  iti  course,  a  twisted 
or  ooAtorted  titbule.  The  upiier  |)art  of  the  collecting  tubule,  though  Btill 
lying  in  the  cortex,  runs  ncarlv  Htmight ;  the  beginning  of  the  descending 
liinh  and  tli«  end  of  the  ascending  limb  of  the  loop  of  lleule,  though  lying 
in  the  cortex,  are  nearly  straight ;  and  even  the  spiral  tubute  is  not  fltr 
renvoveil  fVom  being  straight.  ^  that  the  cortex  does  not  consist  of  gouto- 
lut«d  tubules  only,  but  in  |iart  of  tuhules  more  or  tea*  straight.  These,  linir- 
crer,  are  nut  dia[ter«e(l  uniformly  nmunj;  the  convoluted  tubulea.  hut  are 
gathered  into  bundlen  which  run  in  a  ladial  direction  from  the  bases  of  the 
pyramids  thnHigh  the  cortex  toward  the  ca[Kiule.  The  bundles,  of  which 
tAMV  arc  several  to  each  pyramid,  are  calleil  mtdittlarii  riiyt  or  pvramiiU  of 
Rrreit*  (the  large  pvraniid.i  of  the  medulla  being  iheu  distinguisncd  a«  the 
pyramid*  of  Malplghi). 

Bctwvon  and  i>urr«unding  thew^vcral  mtslullary  rayi*  are  mnww  of  cortex, 
eeen  in  riflinl  si-rtionx  n»  ctiliimiu  bi-twfcn  two  adjarrnt  rays.  coniiiitin|(  of 
oonvohitiil  lubuUi!.  Iwith  lint  and  xi.s-ond.  of  i!iu:iiitg  tubulin,  and,  an  w«  liiall 
aev,  of  Malpighian  capnuhv;  all  the  luhiil<n>  in  the  cohimn  an?  ntont  dinttuctly 
twisted  and  cuittoriol.  ninw  the  c->lum«  contains  only  the  very  lii"^'inniugs 
of  the  spiral  tubule  and  the  collecting  iiiliule.  Th>'  spiral  tubule  beginning 
iu  the  column  of  cortex   iNrtwcen  the  mcdultarv  ravs  miikes  nt  umxi  for  n 


old 


THE    KLIWI.VATIOX   Of  WASTE    moUt'CTS. 


ntodiillitry  ntr,  ilown  which  it  ninit  lo  broome  n  dnccndii 

of  Henle ;  the  ■scpinling  linili  oming  tip  froiu  thv  mi;iliil 

lury  ray  im<l  'inly  1crvc«  it  to  becumo  ii  zigng  lubuK-;  lun)  t-itcli  cnllcrtiDg 

tubiile  ruii?  sirniglil  into  n  nmlullnn-  ny  Uid  iIiodco  aiiiiv  into  tlic  nH->]iiilH. 

Ueacecuch  my  I'ousifte  of  spiral   liibulW,  deeceoditig  anil  aiKTCivdiiig  liiuUi 

(enieoiRUy  the  latter),  of  the  loops  of  Hmlc,  and  colTediug  tiihutn. 

Since  each  medutlnry  ray  remvea  »]>iRil  tnbuW  and  collectioi;  lubulcf, 
and  gives  off  zigzAa  tubules  at  difler«nt  leveU  above  the  baaw  of  the  pyn- 
inids,  it  must  be  thicker  below,  where  it  Itotde  all  the  tubules  which  it  Iim 
ret-eived  or  is  about  to  (-ive  ofl'.  than  hiRlier  up,  where  it  hm^  already  (pven 
offiome  tubules  and  han  not  yet  received  all  the  tiibuUe  which  it  will  receive. 
It  ditninialie.1,  in  t'ai-t, pyramid  fiulji""  <henct.-  ibenune  mraiuid  of  Ferrein), 
toward  the  surface  of  the  kidney ;  n»d,  ludee<l,  jimt  belon  the  capsule  then 
in  It  Ikver  uf  miinc  Utllo  thiokueM  L-unHimin^  entirely  of  cortical  dub^tanee, 
that  1:1,  of  convoluted  tubule*,  the  nieiliiUarv  ray»  not  liuviu){  tu  yet  becun. 

It  is  obvious  that  the  upper  iwrt  of  eacli  m-raniid  of  the  medulla  diffen 
from  the  loner  part,  in  lo  far  s«  tinit  while  the  latter  con taiiu  siniitcht  lubalM 
only,  nnd  thiMt  nxwtly  dim'hnrging  tubulin,  the  former  Fontaiiu.  iMaudM  ool* 
lectin^  mid  diKchnrging  tubule*,  the  ondit  of  the  loops  nf  Hcnic.  which  arc 
mlly  pnrEs  of  tin-  tnbuin'  in  what  no  have  ndli-d  gvncrnlly  their  twiaUd  or 
deTioiM  course.  Hence  the  upi>er  nnrt  of  the  utcdulln  contiguous  to  the 
cortex  is  sometimes  spoken  of  a*  the  boumhry  iont  or  intmiwlintr  mite. 

$  396.  Hiiviiig  thus  traced  out  the  doviwis  >ind  complex  [Mth  Uikcn  by  » 
tubule  wo  must  study  in  more  detail  the  special  characters  of  the  •cvAral 
sections  of  its  cours«. 

Thf  .\f<i{jii^hinn  mp»ulf,  Kach  tubule  begins  iis  wo  Iwvc  said  in  a  globular 
expansion,  having  in  iiinn  a  diameter  of  about  ^IJO  <•.  the  Malpighiaii  capeulv 
or  eii<tcapsule.    [Fig.  lit'i-]    The  several  capsules  are  dispoaKl  Ibr  the  mtML. 

[FMLUl. 


ru«  of  ins  v»«iiti  <  ii]i<<iiTtt>  wmi  tut  tcvtlu    iBcnrxAXi 
t.  a.lubDls:  th «0iMni>taU(iTt   <■.  intrr-i-jTHinhliil  antrr:  d, ■ninviii  )<mnrb    •.  ■loiuerulnf.J 
«llkl«nl  Wlhi  ft  lilMUa  nf  niallaitM  aniund  Ibv  Inbnle.  K  Rullcln  of  ibe  nlM 
ondaa;  4.  aStctM,  soil  /,  tfltn-ni  twtl  of  thr  rIuiusriIulI 


pan  in  serin  of  circles  around  the  medullary  rays  along  their  length,  so  thai 
in  ndial  sections  of  a  kidney  they  are  seen  in  double  rndiating  rows  in  the 
eoluinna  of  cortical  subetancc  between  the  medullnrv  ruy».  Kacb  capsule  is 
ewenlially  a  terminal  globular  expanaiuu  uf  a  tubule,  and  conrisls,  like  tlw 
tubule,  of  a  distinct  and  con^picuiiua  baseiuenl  meiubmiH-.  having  the  ordi- 
nary characters  of  a  buaement  nieuihrane  ($  211).  lincil  by  an  cjnthelium. 
At  one  pole  of  the  sphere  the  caj^ule  a  cuniiDued  on  into  ifae  tubule,  i\i 


A 


TUB  aTRt'OTURg  OF  TOK    KIDNKV. 


617 


I 


ll  ineiukraiie  bihI  ito  «jiil)i«Uuin  bi>ing  vontiiiiioUM  with  i\»p  bufmciil 
membrane  ami  the  t!|iiiWliiiiii  nt'  thn  mbnlc ;  iti  Ihi'  jiinctinn  nf  th«  two  thm- 
ijt  a  marked  <^oi)i<lrictiiiti  nr  ni-<<k.  At  llx-  ii|>jiii«ili-  |>olt' ii  «hitrl  xtrnight  i^muU 
mriery  (of  vhirtf  rclBtiniii)  wi<  will  .'>|>i,!nk  |>r<wntly).  riu  a^<-r«n«,  ruii»  intri 
Ihe  cAptule,  Hrivinjr  U-ron-  it  nml  iiivrrtin;^  iitio  th«  cnvitir  of  tbp  oa{isiilo 
Ihe  b«j»rtK-iil  nicmtininr  itnci  qiithHium  wjiiii-whni  in  the  way  that  om-  niijrhl 
ihrtlM  i>ii<.-'i>  \t.<  int<!  hikI  r>»  invert  at  nnv  pnrt  the  wall  of  a  large  (ligtvut'Teil 
cliwciv  Imll.  Imra<vliuiirl.r  upon  it«  rntnuici;  into  the  cnp«ulc  the  iiHbrGnt 
artery  Hividn  into  ii  itiimlHT  of  hraiiehes.  Each  branch  fiirlh«r  splits  up 
ii>to  It  niimbor  of  ciipillnry  loops,  the  reUintiug  limbs  of  the  wv«rnl  loops 
juiaing,  without  lateral  aDawtomoM*.  to  form  n  sinj;lfl  vein-like  vraed,  txM 
^tren».  The  whole  lobiiluted  buDcb  of  brauctiinff  nnd  looped  vefnels  has 
more  or  Ima  the  appearance  of  a  knot,  and  is  i-nlled  ihe  ghnurulnt.  The 
exact  mode  of  diviiioii.  however.  difter»  in  ditl«ren[  aniiuals  nad  appArently 
ID  different  ca|«tde8  iu  the  tami  kidney;  thus  in  the  ratixulee  nearer  tlie 
roeiliiUa  iIm;  ;;lomeruli  are  larjcer  and  more  subdivided  ilmii  in  tlinee  nearer 
ibemirfoce.  The  vas  eflerens  slariiuR  from  alioul  llie  middle  of  the  hunch 
laniee  from  the  t^upMile  Hide  hy  i^ide  with  the  va-t  alTerena,  thu  urilii'e  formed 
liv  the  inversion  of  the  rniMale  bei»K  not  wide  hut  narrow  w)  aa  jiiat  to  admit 
the  entering  and  inuiu^  veneb.  Heuoe  the  glomerulus  hann  ao  il  were 
into  the  ravity  i>f  tli«  cnjiaule  !<u*pend«d  )ir  a  narmw  neck  eonwi-iling  of  the 
alftrent  and  the  elTercnt  veM«l.  wirroundt-d  bv  ihi-  commencement  of  the 
inven4.>d  porlii'ii  of  the  wall  »f  the  caiwiili'.  WEii-ii  tho  bloodvmtcia  are  fully 
d»lendod  with  lln-  hWA  the  glumrruliif  filU  the  greater  part  of  the  Oivity 
of  the  CHjwute  ;  when  they  arc  conxtricLed  and  cootuin  liltle  blood,  a  apace 
uf  Mome  file  i*  4lcvfl'>jM'i)  l>i'twtx-n  the  etirfaw  of  ihi:  glonwrulua  and  the 
<^poHile  wall  of  the  iii[mii1<.-. 

The  onilhclium  lining  lh«  wall  i)f  the  eapeuhi  <y>tuiKla  of  flat  polvgoiinl 
nucleated  celU  which  have  atm'ut  an  epithelioid  character.  Indwcl,  they 
are  se<Mi  wiih  dilRcuity  and  are  best  brought  into  view  by  the  silver  nitrate 
metlMxl.  These  ct^lU  mt  on  a  baseinent  mcmbraDO  which  as  we  have  said  a 
(lirttnct,  and  in  optical  or  other  aection  preeuniJ^  a  sharp  ouiline. 

The  basement  membrane  over  the  glomertilue  cannot  be  so  readily  dis- 
tinguMied.  It  appears  to  be  completly  fuwd  with  the  mil  of  the  capillary 
leofMi  which  like  other  capillariei>  consist  of  a  liomogeoeoue  membrane  of 
nucleated  epilhelii>id  plates  cementeol  loji^ther    The  epithelium  cnveri&g  the 

f^looeruha,  whieh  follows  the  ine<|iin lilies  of  the  surface,  forming  a  covering 
or  and  dippinj;  down  between  the  Krou|M  of  the  capillary  loops,  and  hence 
is  in  cloae  omiact  with  Ihe  bloodvewels,  is  said  to  differ  from  tne  epithelium 
lining  the  wall  of  tlie  capsule  inasmuch  as  the  cells  do  no  closely  resemble 
epitbelioi<t  plates,  but  are  Battened  cells,  olten  irregular  in  form,  each  with 
n  imiiHpnrent  or  faintly  granular  c-ell'HulROauoe  and  roumled  niicleu!i ;  they 
are  diminctly  cnhioil  in  the  newborn  animal  hut  l>ec»nie  tlatter  iu  thcr  adult. 
Thnit  r«eh  of  the  capillary  liHips  [|f  the  glomLTulus  appwini  t<j  |)ri)jeft.  into 
the  oavily  of  the  <-ji|wuh:  in  such  a  way  that  the  blixHl  in  thu  viatwl  i"  j^cjia- 
rntol  from  the  cavity  of  llie  chimuIc,  and  mi  from  tlii:  himen  of  the  tubule, 
first  by  n  thin  film  ci>mp<nwl  of  the  cuiiillary  wall  (with  which  tl»:  Iwscmenl 
niembraiH'  of  the  inverlcil  purtion  of  the  ca|«ulc  hon  liccome  fuK-d),  and 
next  by  an  epitltvlium  cell  of  Komewhal  |Kvuliar  nature.  As  wv  xhall  proa- 
ently  see  some  of  tbo  prohlcmn  coiirerniug  thi-  Hfrction  of  urine  turn  on  the 
nature  of  the  ptnoeMi*  cnrned  out  hy  thia  iitm  covered  with  this  epithelium. 
Kach  cnpeuto  is  surrounded  hy  a  uninll  ([unntity  of  eounective  tiMae  which, 
vety  scarce  in  the  kidney  genertUy,  i*  more  obviously  here  than  elsewhere. 
Asuall  amount  of  cohneciive  limue  aUo  surrounds  the  atferent  and  the 
effisreDt  veeeel  of  the  t(lon»erulus,  hut  a  minimum  of  this  timue  is  carried  into 


ihe  capsule  with  the  gitMnrriiluB.  Indeed,  the  prcmtL-e  or  ouiinceti^ 
to  tbrni  a  middle  lo  or  n  support  of  a  lutip  or  wen  iu  the  deplhfl  of  (he 
glomerulue.  cannot  be  definitely  demoOBlrateil.  Hence,  lbou);n  vre  hnve 
reaBOn  to  think  that  lymphatics  exist  ia  the  tissue  arauod  the  capsule  M  elae- 
wbwein  the  kidney,  tlfhoa  been  luainlnined  thai  lymphaltt'a  are  abaeot  io 
th«|tloDieriilua  between  the  bloodveaseU  In  ai  all  evcuta  the  penpberal 
portion  of  each  capillary  loop,  eovered  as  it  ^eems  lo  be  elowely  by  epithelium, 
the  odIv  exit  of  material  thnui^-h  thu  cajitUury  wall  Ituidii  direct  thmujch  ihe 
epithelium  iuti>  tho  cavity  of  ilie  uijiatile. 

Thi;  cajxiulv  i»  c-outiiiued  uti  iuio  a  tubule  by  a  shoH  constricted  nnrtinii  or 
Deck  ;  and  hero  the  epithuliiim  Auddenty  chaDMa  i»  characler  and  put*  on 
the  fcsturcs  which  we  are  >iow  about  tn  de«cribe. 

In  the/rol  nnroluleil  tuhufe  the  boaenient  membninc  ii'  dii>tinct  an<)  coii-- 
vpiciioux ;  indeed,  wr  may  *Hy  at  onco  that  thin  dinttnotiu-a*  and  rharpocM  oS 
ouitiiie  of  th<?  htLtcintnt  mfiiibraDO  hold*  fcotid  for  the  whole  li-iigth  nf  tb« 
tuhilii'  urhiiffrtiut  until  wc  reach   the  di^'har^ing  itibulc*  io  the  inedulhi 

and  hiTt  the  buR-mctil  tiK-iubrane  it  l»*t  to  view,  wuiply  beniUH  it  beooii         

fiiK'd  with  ihc  cnncctive-tiwuc  gniinidwork  or  #tnimu.  which  ia  eapeq«ll; y 

well  derclopi'd   in  the  lower  part  of  a   pyramid.     KlMtwbere  the  ' 

oicmbranc  niny  eni>ily  bo  recognized  as  an  independent  inembraiie. 


[  fui.  IM. 


I 
r 

Tl'miEll  ISijU  a  ^U-Kn.i  ui    nil,  INu'*  KlIiHIT. 

0.  <«|>«l«  uhoIuIdi  ilu>  (luMiriuliu:  ri.DivIc  ol  iliriapulp,  c.r.  nnmbiiol  lubulat:ttl 
lutaloi:  d,  c(itlw[ln«iuto^  r.  (.iplnll  tiibni/  parlor  IbaMnndlasIlmtior  U«lilt'>ISDf^lie><c 
Um  w4«IUrT  i*ti  Htm*-] 

The  epilbelium  of  the  first  convnlute<l  tubule  [Fig.  153]  has  the  followl: 
chamders.  The  outlines  of  the  cells  are  very  indistinct.  a«  that  not  unfi 
<|qeiit]y  the  tubule  eeenx  tu  be  lined  by  a  layer  of  eell-^ub»tauec  iu  wbi 
rounded  nuclei  are  imbeddeil  iit  intervals,  wbeti  the  oulliniii  are  maflu  o 
](  u  *««n  that  eai-'h  cell,  which  hns  u  rounded  nucleun  plnitvl  nt  nUiut  i 
middle.  i»  avm  or  le^  cubical.  Hometime^  of  iiuch  a  betglit  an  tu  leave  a  niw 
nw,  noiuelinies  bo  Iuw  as  to  leave  a  fairly  wide  luinan.     Tlio  outer  portion 


THE   STRrCTirJtE  OP  TUT.   KlIiKRV. 


521 


I 

I 
I 
I 


I 


tiou  is  ill  tuni  «iu-(?eedeil  by  a  (UriHon  of  inucli  lurger  diaineler,  in  nhkli 
tho  ocIIb  are  moet  dutiiiclly  strialed  aiit)  otberwrise  itAcmble  the  w]h  of  lli« 
coDVblut^d  tuhulce  of  tlw  maniniHlinii  ki<liiey,  ihiis  ooii^tiliiliiiif  (he  »eoi»i<l 
Mcntinf;  portbn.  Tlie  suceeediii};  iiurtiona  of  tlie  lubiilt'  bi»v«  tbo  chnrBfler 
of  oouductio^  iitbiile»<,  and  Join  rbeii-  felli>wa  [o  fall  ullinuttely  iuU>  Uin 
ureier.  Obvioutily  the  svciind  secrelio;;  |M>rliini  is  repre^'ntt^l  in  tiur  iniiniiniil 
by  (be  ae^oiii)  ci»iv»IiUh1  lubule,  itit-  iU)ir'-'i)iE  tubule,  «ii>l  tho  nw-«iiiliii^  limb 
of  Hcnk'fl  lui)|},  wbile  tbe ilcMMMxIiD); 


^ 


ri  jj 


*.i 


\ 


>J/^ 


limb  of  HetilcH  l'i"|>  oirr^iiands  lo  tno.  iM. 

tli«  Hrcond  ciinducling  dliaU'il  [>i>r(ii>ii  

of  ibc  ninphibian  tubule;  tlir  cilia, 
Iwursrcr,  bBVc  fDtin<ly  ilixnptMarKl, 
«nd  the  liktDcw  \k  cnntincil  (<>  tW  nar- 
rownoK  of  ibi-  whulf  tuhtili-  and  (he 
•bttliceof  se«retiugcharmc(ei>  iii  tliv 
oelln.  Why,  however,  th«  kidney  of 
tbe  lowiT  nninwl  poaweHS  (bit  redit> 
|>lieaUi>i)  of  aecreliiiji;  aild  coiiducliiig 
porlioiM,  and  why  reinaioa  niid  re- 
mains unly  of  llie  redu|)linitioiisb<Hild 
tbii^  be  |ire»erved  iu  the  mwniuaiiait 
kid(M-y  Iin8  iM>t  vel  been  Miii^fuclorily 
«Xi>lnined. 

$  388.  'I1i«  vn»vidar  nrrnu)n,'infiilH 
nf  lb«  kidney  <li9ervi!  i|N-ciul  altt-n- 
tion.  The  renni  nrli-ry  aiijirimcbiiift; 
tbe  kidney  at  ibc;  hiliiN  divide*  iiiiu 
bnincluit,  ubicb,  ii]i|i{mi^  round  ibc 

Iielvis,  vMi±r  into  tlic  Kiibtilanirof  iIk- 
iiiliK^v  Ht  lli^  iinKlt-e  fonneil  liv  llii' 
bnttii.'liii)|i;  of  ihr  jH^lvis  into  c:ilvcc«, 
and  tberelorc  iKHwi-en  ibt-  pvntniids. 
Ituiming  riKliiilly  JH-twert)  tfte  )>yrn- 
niiiU  the  bninchcs.  reacbi»;r  the 
buuitdary  Wtwei'D  cortex  and  nie- 
duDu,  divide  and,  8pFmdiU];>  laterally, 
form  at  (lie  bnsea  of  the  pyrniiiidn 
areb<«  mure  ur  kes  coofienlric  with 
tbe  hilus.  Prom  Uww  uvfaw  [Fiif. 
1^4 j,  vrhich  anaxtonioM-  lo  a  rerluiii 
extent  with  other,  rei<a«lii  jinic^vl  »ii 
the  one  hand  (n  the  oiitex  and  oti 
lb«  titber  lo  ibd  nKHlulIii. 

To  ibft  oorUx  are  givoii  otl'  rvla- 
lively  lyge  arterin  which  run  in  a 
radial  direeiiun  towiml  the  nurfnce 
in  tite  inaatc*  of  orU-x  Ixawii-ii  the 
medullary  raya.  From  each  of  these 
inta--loliniiiir  or  nuiiatftrli'riet.aalhey 
are  oalM,  abort  relatively  thick 
braucben  are  given  off  at  intervaU 

on  nil  tides;  these  takin|>  a  course  aomowluit  curved,  with  the  convexity 
dirx-cta-d  toward  ilie  surface  of  the  kidney,  end,  witbixit  branching,  in 
Maljiigbian  cMjiaule^:  they  are  the  airerenl  vmrnU  N|iok4^n  nf  tircriouxly. 
Other  branehcs  of  the  sanie  radiate  arteri^v  break  up  into  cnpillniiiw  Wr- 


y: 


.A 


VAfei'UR  SL-ri-i-v  nr  Kicmct.   (tuui-t?.' 

1.  laHof  nilcrlBlAieb:  b.  intei^WKilatBnBfT: 
r,  k1'^uu--'<>''u<;  d,  cObrtat  v«anl  punliii;  lo  lu*- 
>liilu  1^  Mtr  nrlartir  rwlir:  f,  ni'lllarliaor  OM- 
!<■»  .  /,  M[illt»rt«  of  mttlullii ;  tf,  nii'iiu  nrh  :  *. 
uni<(Iii  rtlnnof  iixaliillii;'/,  •nut  •lalhila:  (.  In- 
t«<^loblUu>vln.) 


Xl'2  llIK     Kl.IMIXATKIX    UF    WAriTB     l'IH>Ul-CT3. 

r.'im, litis;  tin-  iiiliuK-!<.  this  beiiij;  especially  the  ca^  near  the  furfsice  of 
ilif  kitlnev.  Tlie  vtlereii!  ve*iels  from  the  Malgiighinii  capsules  also  break 
iiji  into  a  i-a|iillury  iii^twork  which,  eTnbraciiiij;  the  tiihtiles,  becomes  con- 
liiiDoiis  with  till'  iiilior  network,  the  meshes  being  ronndetl  or  polyj^nal  in 
till'  I'oriiial  sill  IK  I  a  me.  hut  nmre  elongnterl  radially  in  the  nieiiullary  rays. 
The  bIoi>ilsii]i|»ly  here  repeats  mi  ii  small  wale  the  |)ortal  system  of  the 
livi'i",  siiiit' a  vt'ssel  tbnneil  by  (he  tinimi  of  capilliirie!<  breaks  up  in  capil- 
larii-s  "iiiH'  iihire. 

Knmi  ihe  siiiiie  arleriiil  arches  at  the  boiimiary  of  the  ciiriex  and  medulla 
branchesi  aiv  also  j:iven  utf  to  the  luedulla,  that  is  to  say,  to  the  pyrami<i«. 
ThiiM'  niiinin^  in  a  sirai>;ht  or  rather  radial  direction  down  the  pyramids 
H»  ui'l-riir  iri'lii;  but  sihiu  breaking  up  into  bundles  of  smaller  vessels  also 
ruuiiin};  radially,  supply  all  the  mediillurv  substance  of  the  pvnimidtf  with 
lilooil.  foruiin^  eapillarv  networks  with  meshes  ehintraled  rndiallr. 

From  ihe  I'lipilluries  of  tbi'  pyramids  veins  are  gathered  up,  and  these 
runniuj:  mdially  iiiiwurti  full  into  venous  arches,  which,  like  to  and  even 
belter  doveloix-il  than  the  arterial  arches,  are  jdaced  at  the  boundary  be- 
twii'ii  ibe  cortex  and  medulla.  Kolluwin^f  reversely  the  course  of  the 
ni'terit-s  these  venous  an'bes,  forming  more  luimerous  aniistonioses  than  do 
the  arteries,  tall  into  veins  which,  lunninj,'  radially  tietween  the  pyramids, 
Join  together  over  the  jielvis  of  tlie  kidney  and  Ibrm  eventually  the  renal 
vein;  this,  running  in  compiiuy  with  the  renal  artery,  falls  inUi  the  vena 
cava  interior. 

From  the  enpillarii'i'  of  the  eorti-x,  includiii;r  tht;  medullary  ray,  the 
bliHid,  wmie  of  which,  as  we  have  seen,  hiis  (liis-^ed  through  the  glomeruli  of 
the  Malpighian  euiwule-*,  but  some  of  whieh  has  not,  is  gathered  up  iiitu 
radiate  veins,  which,  riimiiuii  radiiilly  inward  to  the  boinnlary  zone,  fiill  into 
the  venous  arches  sjioken  of  above.  .Vt  the  surfuee  of  the  cortex  the  small 
veins  are  apt  to  be  arranged  in  u  somewhat  star  shapeil  fa:^hiou,  and  are 
«piiken  of  lis  rriiif  fh/hl'i: 

Relatively  to  ihe  bulk  of  the  kidney  the  renal  arlery  hiis  large  dinieusioiH. 
Coming  oft' "direetlv  t'nmi  the  aorta,  wher.'  the  hlood-|iressur<'  in  very  high, 
and  being  com i in ri lively  shon,  il  allords  favorable  eomlitiims  for  an  ample 


•  ■'  i"  ■i.T.lv'of  the  pvraiuida,  consisting  eliielly  of  eondiiviins,'  tubules,  is  to 
""  "^  ir'*  extent  distinct  fmrn  that  of  the  .■..rie\.  wline  the  tubules  are 

^^'^™rM«*t"lUt  for  its  sine  the  kidney  is  most  iUnmdantly  supplied 

*        -      In  wclioDS  of  hardened  and  iirej.ared  kidneys,  the  nrU-rii-s, 

TO_  i'i-»-      ,  i,_g  extent  the  veins  are  emptied  of  their  bl.Mid.  and 

»r.L.uf»  M»  ...lUns^      Hence,  judging   by  such   speeiiLi.>iis  alone,   the 

-^  ^r,ili«r«.J-l»P^  J^,^,  of  tubules  i.lo,,,.;  but  i.  must  be 

ski:.-  «"'*''  '/^.^.rinT  life  everv  tubule  U  netted  ronnd  with  fairly 

.^TW  z.  mill.;  ina-  ^.''""^,  '        „„'niore  or  les<  lille-l  with  blood,  and  at 

„^  «...:an^-m.h,  a  ^^^.^_     _^^  ^^.^  „„^  „,„  ,.  ,„^^.  ,,_^. 

'™*^  "^4,.' -■  iTi-*"**  <ii~  ^f  ^'**"''  ""*■'"»■'  'I"""":-'''  "  '"■'>'  ^■»'">'  '■'^^y 

■»«rl>  Z  *''"■  _^^  CMU.  whieh  binds  together  the  lul.ul.s  and  blood- 
m  1i^  -*'=**^!1"^;,™,  ^T,a!l  amount  ente.v  will,  the  bh.o.l- 
-«!S!**C3r    ■«»»'      .■         .    .J,  i^rpif  branelie^.  but  in  the  cortex 
-  -wTTOo-  ^'|r^^l,anlhe  basement  memliranes  of  the 


TUK  STBirCTUBK  OF  THK    KIliNKV. 


533 


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I 


tubulen,  nilh  u  few  ccinn«ctiv«-ll>«iie  corputiclci'  imhcditcd  In  m  »cant_v  lionin- 
flliyWJW  ikX  iihrillntcil  luutrix  Iviiig  )wtwC4-n  them  ;  nroiiiii)  the  c«)wiil(w  t)ii» 
^itiVn*  \»  FHtlii-r  mor<!  al>iiii(liiiit  thnti  ?  Ik  when',  und  hcrr  i»  mnictimi'n 
filiril luted,  In  the  pyntmUl*.  Mpo<.-mllir  nt  thrir  timer  piirtfi,  «  liirgt'r 
niiiKiiiit  iif  u  ciiiiilnr  liomogcncoiH  matrix,  cooliiiiiiiig  wniiDi-tivv-tiiwic  cur* 

E>ii]ucl<'«,  In  found  Wtwi-co  the  tiilxiles;  nnd  *iii<M!  lit-rc  thfl  bnwmcut  ment 
iniiHi  vf  t))v  tulmlo  i«  luwd   nilh  il«  Blroron,  tli«   tiibul*  appMra  u  a 
UibiilBr  cavity   hollowed  out  of  tli«  niHtrix  or  Rtrunin  nnd   iine<l   with 
vpitholtum. 

Tbc  whole  kidney  is  eurroun<led  hy  n  capsule,  <xiii»iMing  nf  ordinary 
coDlWctire  liMue,  and  ('onlinuous  at  the  hiliu  viih  iW  connective  tissue 
forming  tbe  outer  vrttlls  of  the  pelvis  and  ureter.  This  cnp^ido  may  uller 
<leath  be  peeled  olT,  Mid  slender  proceeacs  of  connective  tisiiie,  with  sodw 
bloodvMselfl  pfUBtng  from  (h»  eapaule  into  the  c<nt»x.  are  iheu  disclMed. 

In  (be  scanty  eiTonia  are  nuinerouH  lyni|>h-ftpactB,  the  lymph  from  tbeat- 
being  colle(.-leil  into  lyinpliatic  vrswU  which  in  part  lenve  tlie  kidney  hy  the 
hiliifi  t»f^lli«r  with  the  blood ve^eeU,  aiid  in  |)art  run  in  the  ca]«ule  and 
leave  the  kidnev  on  its  convex  surface.  The  capsule  i»  dewribn)  n.i  iH-p- 
arable  inW  two  Imytn,  nud  the  lyn)]>lial)C  vnsels  run  chiefly  livtweeu  thnw 
lay  en. 

§  400.  An  the  rennl  nrlcry  pnsKv  to  the  kidney  it  l»  inveatitd  hv  n  niinibiT 
ar(tw<'niy  or  lei's,  in  thu  dog  u  iloxcii  ^r  nion-)  ncrvi*.  arrnnEcl  in  n  niL-xiiK, 
the  rnirtl  filrjut,  Tbe  ncTvi^nrc  compi^rd  niirtly  of  nivdii) lali.it  libm  of 
very  ditlV'n-nt  fitee  and  partly  of  non.nHtlullaitiJ  filtm;  niitneroui'  snmll 
ganglia,  difl«ring,  however,  very  much  in  rixe,  arc  scultered  over  thu 
piciiu. 

The  mrrvn  thus  forming  the  renal  plexus  come  cbieHv  from  the  great 
polar  plcxu«,  and  appear  to  bo  more  immediately  connected  with  (he  part  of 
tfant  plexus  which  is  cwlled  the  sciniliinar  ganglion.  Tbe  plexus  is,  there- 
fore, indinx-lly  conoccte<l  with  the  nerves  entering  into  tbe  solar  plexus, 
Mieb  as  the  right  vaguti  and  the  abdominal  splanchnic  nerree,  great  and 
Hnall.  UeMdes  this  llie  ^lanchnic  nerves  appear  to  send  tilamente  directly 
to  the  renal  plexus;  tilnments  have  also  been  traced  to  the  left  kidney  from 
tbe  lell  VBKus  (which  does  not  join  the  stjiar  plexus),  ami  it  is  coutendeci 
that  filaiueutd  from  the  right  va^u^  also  make  their  way  direct  to  the  riglit 
kidney  without  distinctly  et>mmiiuicaiin>:  with  tlie  aolar  plexus. 

As  ne  flbull  see  there  in  exi><'riuii.-uliil  evidence  that.  In  tite  doff,  nerve 
flbrea  from  the  anterior  rontn  ot  the  eleventh,  twelfth,  and  thirtnnith  dorwtl 
aninal  nerve*  and  even  u  few  lihreii  fniiii  Mill  liiwt^r  nerves  liml  their  u-uy  to 
toe  reual  plexti*  and  *o  to  tin-  ktiliiey.  Tbtw  make  thi-ir  way  fn>m  the 
aympuliieiic  chain,  inlonhirh  thi-y  limt  \tn*ii  either  hy  joining  llie  vplanchnie 
nervi^  low  down,  or  by  a  niortt  direct  course,  to  tlie  solar  plexus,  and  thence 
to  tlie  renal  plcxtin. 

Nothing  verv  definite  is  known  of  the  termination  i>f  the  renal  nerves 
within  the  kitfney.  ^nie  of  them,  and  considering  how  vascular  is  the 
kwliMiv.  probably  a  large  number,  end  in  the  bloodvesM^ls ;  but  some  of  tliem 
must  have  other  ending*.  We  have,  however,  no  evidence  that  any  of  theoi 
are  coitnecled  with  the  epithelium  of  tbe  tubules.  Since  under  abnonnul 
rircumsiances  alTereiit  impulses  sufficient  to  give  rise  to  very  great  pnin  may 
(MBS  op  to  llie  central  nen-ous  system  from  ibe  kidney,  at  least  from  the 
pelvb  uf  ibe  kidney,  some  of  the  fibres  of  the  renal  nerves  are  atlerent 
flbrca;  nnd  soiue  of  tlie  medullatni  libres  are  probably  of  this  nature. 


Thk  CtmixwiTioK  Axu  Characters  op  Uhike. 

it  401.  These  are  so  flilly  dwelt  upon  in  special  mirk»  titat  we  amy  cuuftiw 
ounwivea  here  to  uilietii  poiiitn.  Tlie  healthr  urine  of  man  U  a  clear  y(>ll»«uh 
sli^litly  tli>ure«cri)t  tlu'u).  of  a  (le^-uliar  ixlnr,  Mtine  taste,  and  a<d<l  ntictwa, 
liaviiiKo  Qxuin  sjicvific  gravity  ol'  lO'Jii.  aud  pii<-ntlly  holding  in  i>u*{k>dmiiii 
a  liltle  itiuciii*.  Ttie  miuouh,  witcii  prrii^iit,  coiaw  Iruin  llw  uriiinrv  |>msni^. 
as  do  al4(>  tin:  oircnitiinm!  <![iitlH-Itnl  ii'll*.  All  tlw  rwt  of  tlit  iiniiv  innr  t^ 
I'onHiitiired  a*  llie  xwivtioii  of  ilx'  kidni-y. 

Tlii>  iiriiii'  n»  vie  huv«  Mtid  !■  the  chief  chaiiDol  1>r  wliieli  ■uUd  mnitcn 
leave  iliv  IhmIv.  h  ■mall  <iuanlitv  only  jiaainnK  hy  tlii'  xkiii  and  practimllv 
nuiM  liv  the  luiigd.  Hviicir.  tiegWting  for  lli«  imwiil  the  -kin,  we  mar  mt 
Uial  all  till'  iiiln'taiK-o  takrti  into  \hv  oody  wouorr  or  later  leavr  ihe  body  hy 
tbo  uriiii;.  Nivf  iho  fow  «iiheliiiic<-s  nhicli  may  bo  reUiiHi)  permatwntly  within 
llu-  iHMly  and  the  eutwiaiicos  nliich  iiiako  iii>  tbv  budy  al  thi-  nion)«i>(  of  itt 
di.iilh.  Wc  acL-onlini;ly  Hnd  that  the  iiriiifi  ouiilaiiis  a  large  iiiiniher  of  sub- 
•UUecv,  th«  cxiu-l  ■iiiouiil  of  eaob  sulMlauoe  prceent  id  a  nven  quaulily  of 
uriM  vtr>-iiig,  in  the  rase  of  every  atibatanoe  «om«vrhal,  and  ii>  (be  cmm»  uf 
nuuiy  «iil»t«iife8  very  laruely.  from  lime  to  time.  Tbe  oonipoeitioa  of  urine 
t>  IM»*  odIv  complex  but  extremely  variable. 

Moreover  a  liille  consideraiioD  will  ^low  that  tbe  Mwnil  sttlxHanMi 
preeenl  in  urine  niuM  bave  very  diflereut  hialoriea.  ^lue  of  the  con- 
Miluenta  of  urine  appear  in  it  in  the  exact  form  in  wliii-li  ibey  wrv  iiiiiw 
dticed  into  (be  mouth ;  they  have  been  aimply  absorbed  from  llie  alirutroiary 
<.-aual  iuto  the  hloud  and  exvreted  by  tlie  kidney  wiibout  undergoing  chaogv; 
tliev  are  dtTivvd  din-cily  and  without  cliang«  fmm  tbe  food. 

Olherti  uguin  an-  thu  prodiii-ta  of  obaiigeo  uhicb  ibe  fof^l  liaa  iindergunv 
tbe  bixly  :  and  lli<v«  chaiigiv  may  bo  vlight  or  may  be  extenvive,  Nn<l  ini 
take  ]ilao<:  on  tlx^  one  blind  in  llin  allnH-niary  canal,  or  diinti>;  a  brit-f  into 
of  the  Nuhatance  in  tbo  blood -nI ream,  or  wen  in  ihi-  urine  itiielf,  nmy  an 
sjieak  be  ituper6dsl ;  or  on  lbi>  otbcr  bund  may  tiikv  pla<*  in  the  very  dupi 
of  llw  tiwue*  and  Im-  clwly  aMOciatwl  Wiith  lbi>  wry  life  of  the  Iwuva.  V 
ahall,  hourvrr.  have  to  return  tj  iheiN;  mntien'  liiii>r  on. and  m*y  heri>  hrtel 
oinHKlcr  wliiil  NubetaiK'c*  are,  normnlly  and  alxiormally,  (irMunt  in  urine,  aoi 
the  Mvf  features  of  ilie  fluid  it«elf. 

MOS.  Besides  wilfr,  the  const itiient«  of  urine  arc: 

yitif/'j^nous  erynt'i/liiie  lio'iUji.     Neglnrtiuc  tiw  Biiiull  |>nifKirtion  of  lb 
InmIics  ivhiub,  e«nccialty  in  (he  caao  of  lleeh  entvn.  are  incnMluced  in(<i  I 
oCtiiioniy  with  the  food,  as  kreatin  and  the  like,  and  so  pnss  into  the  urii 
with  no  or  with  oomimralively  lillle  chanf;o.  wc  mav  on  (he  whole  leKard 
■ubnancea  of  tbia  olaaa  as  tbe  ptoduote  of  (he  cfian^m  which  the  prot 
mattera  (an<I  allied  sulistanoes  such  as  gelatin  and  the  like)  present  in  f< 
bare  undergone  either  while  tbe  food  wa«  nmnly  food,  still  in  the  aliinenta., 
oaual  fur  inatance,  or  after  tbe  food  bad  been  built  u]>  into  tlie  tiwuea  of  the 
bodv. 

(Sf  thcac  bv  far  tlie  most  important,  in  tlie  urine  of  man  and  niammalla, 
la  l)i«  IxkIv  urm  (N  H,(X>).  It  in  the  chivf  form  in  which,  in  thm^  animab, 
nitrogen  leaves  (Ik^  imdy.  We  ithnll  have  to  diwcuM  the  n-latioii*  aud  forma* 
tion  of  urea  lnt<'r  on,  but  nieaiiirhilc  we  will  i^impty  (tate  that  it  han  rcioark- 
sbU  double  eoun^wti'itii'  with  two  gn-at  grounii.  On  the  one  hand  it  ia 
ralated  to  tba  ammonia  ei''>up.  and  by  hydration  >•  rmdily  conv«rted  into 
annnoninm  cnrbonau^  i  NJ[,C^>  t  'JH,0  -  i  NH  r,CO,h  On  theotlter  baiKl 
it  is  related  to  tbo  gmt  cyaiiogon  grouj>.  aininonium  eyinate  and  urM  boing 


A 


Ubdln,  «ilb  K  (til  ci)niieel!ve-liH)ii<^  orpusrlett  imbedded  in  h  H^auly  lioitm- 

po^MM  nut  fShrillaUsI  matrix  Whig  Iwtweeii  Uiem ;  aruiiii<l  die  t-u|tsi)lc8  Ihiti 

Know  ii  mtlior  nion.-  nliutnlsnt  iliiiii  elMwherc,  and   liere  it  soRi«tinw« 

B5rilla(«>d,      In    tW    pyrnmiiU.  e«pedttlk    at   li>cir   Inner   jiarts,   a   lai^ger 

—T'llt*  nt  n  oimilnr  liiiiiiu)frnci>u«  niiiirix,  cotiluiuiriK  coiinL-clive-liMtut.'  vor- 

Marlca,  i*  loiiiid   liclitmi  ilif  lulxiirs:  niid  nince  hi-ra  the  bawmt'iit  lucni 

•TKn*  of   thf   lulxilr   i*   fuwril   willi   it*   ntniiua,   the   tiilnilc   nppcnn  ni   ii 

■obtiUr   cavilv    hidliiwctl   out   of  the   miilrii    ur   stri>mn   nnd    lined    irilli 

^>JlJNJiuin. 

Ilw  wbule  kHln«f  ia  PiirrouiKled  hy  n  capsule,  oomliting  of  ordinnrv 
'"OiauiMtivv  tiMuo.  and  continuous  al  the  hiliit  with  the  nmnrctivv  timiA 
fram  mtlag  the  outer  wnlls  iir  the  p«ki«  nod  iireUT.  Tiiie  cn|wii]e  niav  after 
'*^^Mti  be  peeled  off,  nnd  slender  pmcewcs  nf  <'i>nn<^'tive  tiiwDe,  with  tonit* 
IwinItonu  pMHDft  ffom  iha  capeule  into  the  cortex,  are  tbeii  discloeod. 
In  tiM  aouitf  Ptnima  are  iiuiuerDus  Ivniph-spueee,  the  lymph  from  th««o 
colleclef)  into  lymphatic  vessela  which  in  pari  leuve  the  kidney  hy  tlw 
tnjretlier  wilh  th«  bloodvoKU.  and  in  port  run  in  the  capsule  and 
ve  the  kidoev  on  ila  oouvex  surface.  The  cnpule  is  described  as  rep- 
Tahle  intu  twu  layers,  and  the  lymphatic  ccwek  run  chiefly  betireen  tlteae 
ijer». 

i  400.  Ah  the  reuul  aner\-  (hums  to  the  kidney  it  is  iovetted  bv  a  number 
if  <,lweniT  or  leu,  in  the  d'>^  a  doieu  or  mnre)  nervea,  arratived  in  a  plexti», 
be  rffiaf  pifsnu.     The  nervi's  tire  compciwH  nartJv  of  me<iu1lated  fihnit  of 
~^err  diin^rcnt  nut  and   purity   iif  n<>n-me<lullateil  fibrex;   numerous  nnall 
^nnglin,   difStriag.    however,    very    much   in    nijse.  are   ttcatlcred   over   the 
plecua. 

The  otrvt9  ihtit  forming  the  renal  plexii»  come  chicflv  from  lh«  gift 
N'lar  plexuN.  and  ap|)car  !i>  he  more  imme<liatoly  connected  with  the  part  of 
that  plexus  which  is  called  iho  semilunnr  gnnglion.  The  plexus  is,  (hcre- 
fera,  indirectly  connected  iriib  the  nerves  enlcrinK  into  ibe  solar  plcxu», 
Mch  aa  the  riglil  vtigxts  and  the  abdominal  splanchnic  nerrea,  great  and 
wnall.  Uoidea  this  the  splaDchniv  nerves  appear  to  send  filaroeiits  directly 
1(1  (he  renal  plexus;  lilanientA  have  aUo  Iteen  traoed  to  lite  left  kidney  from 
iiie  U-A  v»)cus  <  which  does  not  join  the  solar  plexua),  and  it  is  c»ntendeil 
tlwt  filnmentB  fr»m  the  ri^lit  vngu*  alio  make  iheir  war  direct  to  the  rigbl 
fcidoAf  without  distinctly  cumminiicniuii;  with  the  :>iilnr  pivsue. 

A«  »e  nhall  we  there  i*  cxmrimeutftl  evidence  that,  !n  the  dog,  nerve 
SbrM  fhmi  the  anterior  loou  or  Ibo  eleventli,  twelfth,  iind  ihirieenlb  doraal 
•pinnl  nervtM  and  rvcn  a  few  fihn-s  from  still  lower  w'tvv*  tind  their  way  lu 
Xnm  rvnol  pU-xiis  ami  wi  to  the  kidney.  Thiwe  nmke  ihi-ir  way  fnmi  the 
■5'ni|wllietir  ehnin.  into  which  they  Ural  pnxs  either  br  jninin):  the  splanchnic 
iMrrea  low  down,  or  by  n  nx^re  direct  courw.-,  to  ihe  solar  plexus,  nnil  thcnec 
t*»  Ihe  rcDiil  plexus. 

N'tXhing  very  delinite  is  known  of  tho  termination  of  the  renal  uervra 
within  the  kidney.  Some  of  them,  and  considering  how  vascular  ia  the 
Vtdivev,  probably  a  large  number,  end  in  llic  bloud vessels ;  but  some  of  them 
■BUit  nave  lUher  endings.  We  have,  however,  no  evidence  that  any  of  them 
ate  udinecletl  with  the  e|rithelium  of  the  lubulea.  Since  under  abnormal 
cirwuRisUncea  atfereui  inipulseit  sufficient  to  give  rise  to  very  great  pain  may 
fmm  up  to  the  central  nervotis  «yi*tem  nt>m  the  kidney,  ai  least  from  tba 
l>rlvi»  of  the  kidney,  wtue  of  the  librtu  i>f  the  renal  nerves  are  alfertnt 
flbm :  and  aome  of  the  niedullaied  hbre*  are  proluhly  of  this  nature. 


* 


i 


i 


The  Co«positii>s  axd  Characters  op  Urine. 

§  401.  T)i«*e  niv  Hi>  fully  di*«lt  ii]iou  in  ftjii-cinl  work*  tbnt  i>v  mnr  coofis 
ounelvca  here  til  «a]iL-iil  p(iint)>.    TWlipnlthTurincuf  Duinwa  Hmr  yellow t 
allg^htly  fluDKuccnt  fliiu),  of  n  [H'c-uliar  <iil<ir,  mViiw  lnrt«,  nii'l  H(.'i>l  rnwtMi 
liavinga  mcjin  i>iii: !.■!/)(■  fjritvily  nf  I02il,  iind  gV'iK-mlty  hiililin^:  in  MMpcoiia 
II  litllo  niiiciio.     Tliv  tiiucii*.  wlifii  ]trr»«nt,  romra  from  the  iirimm- 
iM  il<i  iilv<  (hv  (KTcaKiotiiil  <^]ijtlicHiil  cell*.     All  tho  raU  of  thft  nniH-  nuy 
cnnnidcn-d  n*  iheewn-lioii  of  the  kidnrr. 

Till.-  iiritio  as  we  hwvc  (mid  i«  lh«  I'liicf  clianoel  by  trhich  wIkI  mat 
lonvo  Iho  body,  a  rdkII  <|UaDtilT  only  piiMing  by  thi?  rkiii  nod   practicall 
none  bv  tho  lunge.     Hence,  iiefi;lecUiie  for  llic  pre»ut  the  'kin.  ve  lunv 
that  all  itifi  siibdtaiicee  taken  into  the  body  soooer  or  later  leave  the  boily 
the  iiritie,  Hive  the  few  fiiibelaDces  which  may  be  relained  i>erRuiuently  irilhi 
the  bcKly  and  the  subalanees  which  make  up  the  body  at  the  niuiDcnt  of  i 
desiJi.     We  aciyirdtti^ly  litid  that  lh«  urine  cimiainii  a  lar^  number  of  sul 
atanco.  llie  exn<-l  aiii<>utii  uf  each  Bubaiaiioe  present  in  a  civen  quantity  «>/ 
urine  VArytuii.  in  the  uate  of  every  euhetance  eomewbal.  and  in  the  caaa  o/" 
mzaj  subslauL-eH  very  largely,  fmtii  lime  t»  time.    The  voinjMMilion  of  urin* 
is  not  only  comiilex  but  extremely  variatde. 

Mxreiiver  a  little  cinixidcmtion  will  »hi>w  that  the  aereral  anbatanctt 
]>re(tei)t  in  urine  iniist  have  very  ilitlerent  hiatoricfl.  Some  of  the  caa- 
stitiieiil.i  uf  nrinc  appear  in  it  iu  the  exai-l  form  Iii  which  they  irere  itrtn- 
(iunil  iiil'i  the  mouth ;  they  have  been  »imply  alwirhed  from  the  alintentaij 
canal  into  th<;  bloml  and  excreti'd  by  the  kidner  without  uudergning  clian)^; 
thev  nn:  di'Hveil  direcllv  and  withuul  change  Iram  the  fni)d. 

Other*  again  are  thcprtxluct*  of  chanp*  whirh  the  )!Mid  lia»  iindergoiw  ii 
the  boily  ;  and  th(!«o  changes  may  W  flight  or  may  be  eklciMvu,  an<l  mar 
lake  place  od  the  one  hand  ia  the  ulinientary  oaiial.  or  during  a  brief  Innat 
of  the  Hubfttnnt.'e  in  the  blood -stream,  or  evon  in  the  urine  itself,  may  io  to 
Apeak  be  Huper6cial :  ur  on  the  otlter  hand  luay  lake  place  in  the  very  depths 
of  iJie  tiitwieB  and  be  ciiisely  awociated  with  the  very  life  of  the  tituuca.  We 
shall,  however,  have  tii  return  tj  these  matters  Inter  on,  and  may  here  hrieflr 
ooiiBider  what  HulHianeeii  are,  noriually  and  abnormally,  prewnt  in  urine,  anS 
the  chief  fcaturcn  of  the  fluid  itaelf. 

$40S.  Bc*idi?9  uiili-r,  the  consliiueala  of  urine  are: 

Xilr<,iirnoii»  crytinlliuf  liorlieii.  Ne(rleetinj(  the  ftinall  proportion  of  lhee» 
bodiea  nhich,  twiurdnllv  in  the  ciu^  'if  fla>h  eateta.  are  tntr<)duced  into  the 
economy  with  itic  iuwi,  ii«  knuttiii  aud  the  like,  and  a\.<  pav  tulo  the  urine 
wilh  no  or  with  commralivdv  Htile  change,  we  niav  on  the  whole  regard  the 
■ubtUUKM  of  Uiti  clasa  a*  tlie  jiroduvtit  «f  the  vbaagea  which  lh«  praietil 
matter*  (and  alli<'<}  *u1)i>lun<'i*  nurh  a>  gelatin  and  the  like)  pr<-^at  in  fund 
bara  undergoito  eilhrr  while  the  food  wax  «iniiily  fund,  rtill  iu  thr  aliitu.iiiary 
canal  lor  iiMiaiice,  or  after  lli«  food  had  bi-en  t>uilt  up  into  the  tiwuc*  of  tho 
bodr. 

df  theee  br  far  the  most  important,  in  the  urine  of  man  and  nuunmalia. 
is  the  body  urea  (N,H,CX)).  U  is  the  chief  form  in  which,  in  tiKse  aiiintala, 
aitragea  hbtm  the  body.  Weshall  have  to  discun  the relatiouH  and  forma- 
tion of  urea  later  on.  but  meanirhile  we  will  nmply  alate  tluit  it  has  n*inark- 
able  double  conuectionB  with  two  gmi  groum.  On  the  one  hand  it  it 
relatnl  to  the  ammonia  ifroup,  and  by  hydration  is  readily  converte<l  into 
nmmuniuni  carbnnale  lN,II,00  +  2H,6^-;  tNH,',(-'0,i,  On  the  other  hand 
it  ia  r<-taied  to  tho  great  cyanogen  group,  aimuouium  eyaniile  aud  urea  being 


fADACTKR!}   Of    L'RtNK.      ^25 


I 


iiKiiiuTic.  fl»i]  lliv  former  1>r  «iRiple  Iifutmj;  \mng  converted  itilo  the  Iniltr 
(NH.-CXO-N.H.CO).   ' 

TliMigh  a  hnw,  fonniii^c  ntlu  with  Hi-ida,  such  as  Ditrat«a,  osalalm,  Hi'., 
(irctt  oociini  in  Mrine  in  n  iVw  tuid  iiidcjiemlvnt  (."omlilion. 

CIomIj  aUit'd  tn  uo-n.  occurriiiu  ai>|i«rpiitly  tw  a  bv«  urwluet  of  the  wiino 
lin«  of  inetAbolitiii,  in  xWc  acid  (C,H,N,0,s  whidi  m  found  atnajr*  iu  ihe 
urine  of  man,  oocurrinji;  in  itnuiil  but  variable  (|iinntity.  la  tlu*  iirino  of 
BODW  iniuMlo  such  as  binle  and  rcplileH  il  ucnirs  in  iitiiindancc,  and  inde«d 
in  Ulfln  replaces  urea  m  the  chief  nitixiuiiKHiN  i:xrrctii>n.  Uric  acid  ia  a 
inore  complex  IkkIt  thiin  nr>ni.  one  molecule  of  nric  acid  :<pli[ting  up,  under 
tite  influenee  of  cerinin  reagents,  into  two  inolcculat  of  tirea  and  a  com- 
(loimd  of  oialie  acid,  ha  [tecom  posit  ton  product*,  however,  under  diSbrent 
reag^nlfi,  are  very  uumeroii»  and  coinplox.  though  urea  occurs  amoDf;  them 
flre>|uently  and  eharacleriHlically.  Uric  acid  may  be  synthctictilly  produced 
out  of  nrea  aitd  Klvcin  fglvcocolj. 

It  is  a  weak  dibaaic  acid,  and  occurs  in  nortuat  human  urin?.  not  aa  a  fVee 
acid  but  as  an  ucid  salt,  being  combined  ivith  potassium  nnd  sodiuui.  and  t» 
■  Um  extenl  with  calcium  and  ammonium.  In  ouitc  Dormai  urine  tlicM 
mIu  are  aolubl«  in  the  urine,  even  aller  the  fluid  ha*  cooled  down  to  the 
ordinary  temperature  of  (he  air:  but  not  inffe<|uently  the  urates,  soluble  in 
th«  urine  at  the  teoiperaiure  at  wliich  it  leaves  the  iKtdy,  are  precipitnt<«d 
when  tite  tluid  cuoU,  fumiing  the  well-known  "depiwit  of  urate*.'  On 
furtliLT  ttandinf;  Ihe  salta  are  apt  to  be  decomposed  and  thiu  to  give  riae  to 
eryvtaU  of  urte  acid. 

Btaidea  urea  and  uric  add  the  urine  contains  small  but  variable  (]UBntitic« 
of  inonvr  leM  nearly  allied  iMxlies  such  as  kreatinin,  xanlhin.  Uv{H)xniiihin, 
aiKl  pianin.  (Vmcoriiing  ibeno  w«  will  at  present  only  say  that  kreatinin  is 
a  bydraled  (orni  of  the  l)o<ly  kreatiii  which  we  spoke  nf  (i  Ii2)  a*  a  eonetiueul 
of  mu«cl«f.  Kreiiiin  hy  hydration  ia  readily  ronvLTttnl  into  ki\-«tinin.  and 
kreatinin  by  dehydraliKU  inli)  kreatin;  krutlin  intrndiierd  into  I  lie  alinitrutary 
canal  or  into  tin-  blood  appttir<  iji  the  uriti<^  u.->  kreatinin  ;  and  iu  lle:°b  enl«r« 
some  at  t«!ii*l  of  the  krvaliiiiu  •>f  tin-  itriiii:'  i.i  di-rivinl  dirvclly  from  the  krealin 

C-eaetit  in  the  meat  eat4.-n  lu  fund  ;  hut  we  sludl  diwuM  the  subject  of  krealin 
teroii. 

BeeMea  the  abvve,  twh  bodi«f  aw  leucin.  taiirin,  cystin.  allantoin  and  am- 
mnnium  oxalurain  are  occaeioiiaJly  found  iu  urine,  hut  cannot  be  regarded  as 
cofutitueiits  of  normal  urine, 

In  ihe  urine  of  man  hippuric  arid  oppeani  to  be  always  ]>r«flent  in  small 
i]uanlilia,  and  in  the  urine  of  herbivura  occurs  in  large  iiuanlitics.  [n  theae 
lailer  it  ia  derived  more  or  l<n»  dirvctty,  by  eluinges  ol  which  we  shall  have 
to  speak  in  a  succeeding  chapter,  fruiii  conMiluonu  of  the  food  containing 
bodies  belonitiog  to  (he  aruuiatie  group  (benxoric  acid  series) ;  but  the  small 
iiuaniitv  preaeut  in  man  and  other  earnivora  appears  to  eome  from  the 
motaboiiani  of  j>rotei<l  matter  which,  as  uo  have  already  seen,  contain*  an 
aronatJe  wittUlueni.  Another  member  of  the  aromalic  );roup,  lyroMin,  is 
nocnuonally  preeent  in  urine:  and  as  more  regular  eunstiUienta  uf  normal 
urine  may  be  mentioi»ed  certain  phenol  compounds,  such  as  pheDysulphurk 
acid,  (be  phenol  coniitiiuents  of  which  are  derived  fVom  tlie  action  of  niicru- 
organisina  in  the  alimentary  eanal.  see  {283  ;  these  subetanoea  though  they 
no  longer  ctwiaJu  uitro|{en,  lake  uriKiu  from  bodtee  of  the  aromatic  series. 
Similar  ehauaea  are  al»»  the  source  uf  indigo  compounds  (iiidiean'i  in  the 
urine,  derivwi  fr^im  indol.  !>ee  §  'J4!f. 

§  403.  lHori)»n\r  Mitt.  Thette  for  the  most  part  exist  iu  urin«  in  natural 
lution,  tin-  <y>m{)<Mitiiin  of  ilte  Hdh  almost  exactly  corre* ponding  with  the 
-  ilu  a(  the  dinct  au»ly>iH  <<f  ihe  fluid  ;  iu  this  respect  uriue  cnnlraata 


626 


TlIK    BLIMtVATtOX   OF    WA3TK   ritOlJDOTa. 


forcibly  wiiU  Wood.  l\u>  ntU  i>f  irlilch  U  Inrgfly  oompawd  of  Inr.rii  :li. 
fltniicvs,  wliit-h  jirrviouK  l»  ihw  iiicincriilitm  fxixtocl  iii  |MictilUr  .  n 

wilh  prok-iil  iiiii]  <aImt  corijiIok  limliiii.  In  ihc  ii»h  uf  uritii'  ttiiT<-  it  ralbr; 
more  sulphur  than  <\>rmp<intl.<  tu  llu-  Miljihiinc  aci<!  ilin-i-lly  <lrrtvrmii>f«l ; 
thie  iuiJictiU«  the  «xi»ICDw  in  iiriix-  of  Miiiit!  itul{>bur-hiil<litig  cotuplvx  bodf- 
And  there  mrv  IrsMs  of  iron,  {xituliiig  In  »<itiH-  ^iinihtr  iroii- holding  sub- 
Malice.  Hut  qihcrwisc,  all  the  suWativtw  found  in  tbfi  iwlt  trxtst  as  wlb  m 
iIk  imiura)  duid. 

The  chief  bftMa  are  aodium,  potaniiini,  cnlcikim  luid  magneeium  in  ilr 
fonn  of  dlloridcs,  ^osphntea  nud  aulphtilM.  Th«  exact  way  in  nbich  ikt 
Bevenil  haaes  oud  acids  itre  combinecl  is  to  some  extent  a  mailer  of  uii»r 
tainty;  but  sodium  chloride  u  ooriitinly  |>resent  and  in  cnnsiderabli;  (luan- 
tity;  it  it  the  inosl  abundant  and  important  inor^auic  coneliluent.  A  Itttgi 
Itortion  of  the  phoaplioric  add  seeata  to  exist  as  acid  Boditiai  phuaphiUe,  the 
rest  aa  soluble  calcium  aud  magDOuum  phcaphatee.  The  reuainiag  chMi 
mlU,  occurring.  Iiiiw«v«r.  In  smaller  quantity,  are  ]M)taa&ium  aikd  aodiiiin  tnl- 
phale,  Bud  calcium  chloride. 

Ammonia  occure  in  Hmnll  quantity,  alkaline  carbcHialea  an  frtHjuaUlr 
fiiuml,  tract'*  of  iiiiriili'H  uru  at  ull  eventii  oci'ani'iiially  i^reaeiit,  aa  ttloo  ion- 
cations  pf  ulicatcs  and  of  i>ul|ihii-i-yaiiHte». 

The  |>lttwphiUe«  are  iltTiviil  partly  frxmi  the  )th<Mipha(M  taken  na  such  is 
food.  |iiirtly  from  th*  ph.Hphoriw  or  phtuphaKv  (ictuliarly  awociatrd  inlli 
the  protciiU.  aixl  {uirtly  ft'ito  llie  phiupbnrui'  of  cerlaio  oumplox  fats  eudi 
as  lecithin.  When  urlni'  bvcoinca  iilkulhic  (and.  lu  we  nhall  preaeutly  set. 
it  may  da  so  by  changes  taking  place  in  iu<i-lf )  the  calcic  and  nia|;iMeic 
phosphates  are  converted  into  du«c  Mllif  which,  being  i»»>liihle.  are  pte- 
cipitated,  the  sodium  phosphate  retiminiiig  in  solution,  When  tl>e  alka- 
linity, as  is  ffvquently  the  case,  is  due  to  iimmooia.  nmmonio-magneaiuin 
phosphate  is  formed  and  is  apt  to  ap|>e«r  in  crystals.  The  sulpbaten  are 
derived  partly  from  the  sulphates  taken  ns  such  iu  food  and  partly  from  the 
sulphur  of  the  proteidE.  The  carboualee.  when  Dcciirrini;  in  large  quantity, 
generally  liave  their  origin  in  the  oxidaliou  of  such  sails  as  citrates,  tartraUs, 
etc.  The  baiw«  prttteut  uejMind  largely  on  the  nature  of  the  food  taken.  Thai 
witli  a  vegetable  diet,  the  exceca  of  the  alkalies  in  the  fou<t  reapiMim  in  the 
urine:  with  ananinial  diet,  the  earthy  bases  in  a  similar  way  come  li>  the  frooi. 

§404.  Xon-nUrot/enoiui  boitU^.  Ihese  exist  in  very  small  quantities,  aad 
many  of  thmi  are  probably  of  uncertain  oL-ourniiice.  i^Hno  of  tlieM  arc 
organic  avid*,  the  most  constant  |ierha|i^  being  oxalic  aold ;  to  thia  may  b« 
added  glrccriu-pli>mphDr!c.  lactic,  formic,  aoblic,  butyric  anil  possibly  suc- 
cinic acids.  Intuit  hax  alio  been  mid  to  occur  normally.  It  has  boto  maili- 
tainc<l  llint  miniili'  (piaiititicji  of  ^ugar  ('(k-xlriBu.*)  an-  invariably  pnjscnl  in 
even  hi^allliy  urine;  tUix.  howcVi^r,  haii  not  iu>  yet  been  placml  Wiyuitd  all 
doubl.  Tbe  nattin-  of  iht;  siibttanees  uhich  give  to  urine  its  charadcriMia 
<Mlor  bus  not  liecn  mnile  out ;  ]iro)>ably  thrn-  arc  more  sucfa  bodic«  than  one. 

§405.  Pi'jmcnU.  Urine  i»  always  colonil.  Ihc  tint  varying  from  a  light 
to  n  ilark  ycllon  with  an  admixture  of  briiwn.  In  the  course  of  twentv- 
four  hours,  a  not  inconsiderable  quantity  of  pigment  must  leave  the  body 
by  Ibc  urine;  but  the  nature  of  the  normal  pigment  or  pigments  of  urine 
is  at  present  obsciini  and  the  subject  of  much  controversy.  The  matter 
is  apparently  further  complicated  by  the  presence  in  urtue  of  what  bat-e 
bi-eu  called  "chromogenf^,  *  that  is  to  say,  bodice  which  are  not  colored 
tbcntEelvra  but  which  reiwlily  give  rise  to  pigments  upon  oiidnlion;  and  it 
is  probable  that  soom  of  tbD»e  "  chrumogeus "  of  the  iiriiie  are  rednctloa 
pnMlucts  of  the  respective  pigments,  the  reduction  lakiux  place  in  the 
urine  atler  aecretii>n,  or  during  or  cren  before  secretion.   There  is  fretpiently 


TUK  coMi'osirios  Xwl^irHfACTKKO  upTk^^.     627 

|irt«eiil  ID  uriii«,  i-»|ici-iiilly  in  cmra  of  ffvtrr,  »  pigment  nhiob  has  Ixvii 
)ii<>lHl«()  ami  ilrlcrmii)).-)],  which  him  ii  thantrirritlic  *i>o>-trutii,  anii  which 
Wing  iiininUincd  br  nnDio  lu  bo  »  drriviUiv*  »{  biliriiutu,  has  be«i)  oillcii 
tiroifilin.  It  18  not  ihis  iitttbilin.  howi^vcr,  which  f(iv<e*  to  urine  iu  ontiunry 
color.  Some  obeorven,  on  (he  oth«r  haml,  ninii)tain  ibat  normal  uHiio  <Ion 
coDlaiii  and,  id  pnrt  nt  Icnst,  owes  iU  Domial  color  to  a  soiuewhal  Hiinilar 
but  dilterenl  body,  which  In  ocMi(ier)U«noe  tbey  have  nllt-d  "  iionnal " 
urobiltu.  It  is  in  fact  Dot  pomble,  at  th«  present  niomenl,  tu  make  dclinite 
and  ealbTactory  itotenienia  aa  to  whether  urine  coutAiua  one  or  n>i>rc  than 
uue  normal  piffinetit,  as  to  its  or  llieir  nature,  a»  to  wlietkvr  they  arc  (lerived 
from  bile  iM^ment  or  directly  from  the  hwmatin  or  htemosloMn  or  in  otl»er 
wajrs,  or  as  to  the  several  stepe  by  which  tbev  are  pniiliuxil.  Tliere  are 
iilao  abnonual  ovioring:  matters  prcoeut  on  ocnwion,  auch  for  imtnnce  as  ilie 
pvculiar  reil  coloniiK  nmttt'r  <iceurri»)t  >oniet!nie«  in  tbo  tirine  of  actite 
rhvumali^m,  wiiieb  haa  l>eeii  caDed  uroerytlirtn;  htit  our  knowWgc  coit- 
ivriitnK  lliftw  nre  very  ininerfpct. 

!i4W.  f'rrm''nU  and  othrr  htKlif*.  Kven  normal  uriiw  bn«  frcqiientlv'lieeii 
found  t»  contain  a  vniall  <|nantity,  hardly  amoMntin^'  to  more  than  a  trncc, 
of  prot«i<l  material,  a|>pari'ntly  an  albiiniiu ;  but  the  nornml  presence  of 
vv«D  ibit  amall  <|uaiit!iy  lin«  t)«cn  diHpulcd.  Urine,  however,  certainly  cvn- 
lKin«  funuiMit  Ix-liiv. 

Wlwn  urine  i«  trcatMl  with  many  \\a\vr  it>  volume  of  alcohol,  a  Knuiiilar 
or  docculonl  pm-i|>itNtv  is  thrown  down,  cunnistinf;  chielly  of  phii«|>hnt<«, 
tAfCther  with  Rome  other  fubtttanotw  or  probably  «i'vcral  other  snlminnces,  in 
very  Moall  (|Uantitie».  An  ai|Uvo(i«  solution  of  tho  precipitate,  which  maj 
be  freed  from  the  pliiiephatc«,  i»  b»tb  awvlolytic  and  proteolytic.  .  Porments 
may  alao  and  more  rendily  Iw  esiractrif  from  urine  by  allowing  Nbrcds  of 
librin  to  soak  in  the  urine  for  a  few  hours,  and  then  removinji  and  washin); 

Jthem.  Tbe  ferment*  become  entangled  io  the  fibrin  in  iiui?i  a  oav  m  not 
lo  be  aaeily  removed  by  wasliinft.  The  waabad  shredi*  nil!  mnvi.'^ri  «urck 
into  sugar;  and  when  treated  with  dilute  hydrochloric  ncid  di;^«t  them- 
•elvea,  abuvriuK  ih«  presence  of  pepsin.  By  thit  method  it  hii.->  b<vn  asoer- 
taineit  that  an  aniylulytic  ferment  and  pepein  are  pn-sent  in  <|unniitii-fl  which 
vary  in  the  twentyfuur  hours  acoordtux  to  i\\k  me:*!^.  K-^nuin  has  aba 
l>c(^n  found,  and  at  tiatea  at  least,  trypsin.  From  tbi*  it  apiwars  that  some 
of  the  fcrmi'iits  uf  the  alimentary  canal  «c«)ie  from  the  bwlv  bv  tbe  unue, 
Ix-ing  proltably  re-absorbcil  directly  from  the  reajwctivtt  ((land ;  tike  (juantity 
ntoreoTcr  nhich  ibuaeseapu  ih  intii^cuilicant. 

A  Riuall  <piimtily  of  ga«,  about  \h  vnU.  jwr  vcjit..  oiin  hv  extracted  by  the 
mercurial  pump  from  urina  revdved  direct  from  the  body  without  exposure 
to  air.    Tfie  ga*  no  obtained  coo^sls  cliK-lly  of  carbonic  acM.  nitrogen  being 

ivary  ■'*^i>tTi  and  oxvf^-n  oocurrin|t  in  very  umall  <iuanlttiM  or  beiuff  witolly 
absent.  The  meaning  of  thift  we  nave  alniady  touehoil  upon  in  ^leaking  i>f 
respirntton,  see  $S*K>- 
$407.  The  quantilws  in  which  iheae  mullifariotw  Wlies,  all  of  which,  as 
we  have  seen,  we  may  perlmps  regard  as  coiMilueats  of  normal  uriiM,  are 
pruMDl  in  ditlerenl  apociroeiis  of  urine,  vary  within  very  wide  limits,  bi-ini; 

»  dependent  on  the  nature  of  tbe  fond  taken,  and  on  the  coitditionn  of  the 
iMtly.  Tlw  amount  not  of  water  only,  but  of  many  of  tlw  othcj-  M-rcml 
ooiiatiuients,  varies  widely  and  indeed  rapidly,  so  that  the  pcrceutiifte  o»m- 
niKUtlon  of  urine  will  vary  from  hour  to  botir  if  not  from  minute  to  minute. 
Tbo  causes  which  determine  these  variations  in  tlie  nature  and  amiviinl  of 
urine  we  shall  study  later  on.  Meanwhile  what  may  be  railed  the  averajie 
coiuptMithHi  of  human  urine  is  shown  iu  tbe  followin);  table  in  which  the  nci^i 
gd  \m*n  aro  put  down  aeparalely. 


628 


AuouNTs  OP  TB£  Sbvcral  UniN.tRv  CoNaTl-n'B^m•  Pawbo 
IX  TwE.tTT-pouR  Hctcid.    (Afcr  Paiikis.) 


Bj  an  ■«»■» 
mui  or  IK  klloa. 

IV.  I  Ul»                                             ~ 

of  b(dy>iir*«^t. 

Wnter 

1.1(M.0ft0gnioiiRr>. 

£I.UU(>0  f;raniin«. 

TirtuI  ii»liiJ« 

I.UmMi 

Ure» 

83.)>>0 

O.AOUU 

tJrIo  Ai!(I 

U.S3A 

a.oo»i 

Ilippiiric  ndfl 

(i.«0 

0.0060 

Krratioia 

0.UO 

0.D1W 

I'igairnt,  uiid 

oiUer  Hulutuiicea 

10.000 

0.1. ',m 

Buljiburlc  atiil 

3.013 

O.OHOS 

Ph<««|j|nirii'  acid 

S.I64 

0.04S0 

riiiiiriiio 

7.000 
(8.21) 

0.19(10 

'  Aminoubi 

l).770 

PoMariom 

3.5D0 

Sodium 

11.W0 

Calnum 

0.26n 

Ua){nfriiuiii 

OSiir 

T3.11IXJ 

I;  408.  Ttie  iieiiiily  of  urine.  The  lienltliy  iiriue  or  niim  u  ncM,  owing  t«> 
thu  pri.-M'iit-t-  <<t'  aui<l  fioiliiini  }>hi>s|iliate,  the  aliaeRce  uf  free  iu-i<l  lx.>iug  ilto^wt) 
|>j  ilii^  fuel  thiit  UHliiiiii  liyjioaulpiiiie  ^'ivei>  no  nreripitaic.  Tl>c  nmotint  of 
eiility  i.4  xlriml  e<|ijivaleiil  i<i  '1  ;,'raiiiiu«i  of  oxulic  iid<l  in  tw^niv-four  hoLa  rv, 
.  Jt  tlii^  ili-yrw  of  adililv  nl  aiiv  oue  time  varies  mu<-b  during:  if'C  "luy.  tx^ing 
in  ■&  invoret-  ratin  to  llic  atuoniit  of  add  oecrMMl  by  tli«  itomnch :  tlits  ^  il 
cl«cmis»>  nfler  loin)  ii>  tiiki.ii,  utid  iiK'reiL<nt  »)ptiii  iw  g&slric  digmion  cokkio* 
to  ui  end.  It  vnri<.-»  nitli  the  iinlnre  of  (lie  IWI ;  wiUi  k  %-<cet«ble  diM  cfar 
exc»B  uf  alkniitf  in  t)ic  fixid,  Imng  ^ci-n-Ktl  by  the  iinii«,  l«ads  to  allcKlin  i  ty. 
_or  at  leaiit  lo  diiiiini»ticd  nridilv,  wti<'nMU  title  cfl^ct  a  wintiog  with  au 
~  limai  diet,  in  trhtrh  tho  n1knli«'«  am  l(W  abiiiidnnt,  nrtby  bsMv  nrc- 
_  oiidemtinK.  Flcnco  iho  urine  of  nirnivora  is  |.>?iieT«lly  very  acid.  wl»itp 
tliHt  of  Iierbivora  St  nlknliiK'.  Thr  Intirr,  uhcn  fasting,  are  for  the  Lain* 
being  carnivorous,  living  Milircly  on  their  ovrn  bodies,  and  hence  ihdr  uri"* 
becomes  uiidi;r  tUoe  circtimstaiiev«  acid. 

Tlic  iialunil  aciditv  increaem  for  some  time  afler  the  urine  has  twen  «3I»- 
cfaarged,  uwing  to  tfie  formation  of  fi-esh  acid.  a[>pnrenily  by  somo  kind   oX 
t^roientaliou.     This  increase  of  acid  frequently  cauMB  a  urectpitnliun     of 
urato.  irbieh  tbe  previons  aci<iity,  even  after  tKe  cooling;  *»  the  urine,  h<^ 
becu  iiwullident  to  throw  down.     After  a  while,  however,  the  acid  n^ctt**" 
give*  way  to  alkalinity.    Tbi^  ia  cau»eil  bv  a  couveraiou  of  the  urm  io  ^^ 
ammonium  carbonate  ihrouj-b  (he  agency  oi  a  ^teciBc  "  organi/e<t "  f^rroei*-  ^- 
Thii>  <ermi;nl  ti»  a  gciit.'ral  rule  doea  not  make  its  appearance  exiiept  in  uHk^^** 
exjMiMfl  lo  till'  air :  it  U  only  iu  unheallby  cMiditiona  that  the  rermcntali<=^^^*'^ 
lakc»|>lnix- within  tbe  bladder,  and  in  sueh  ca*ea  \*  due  either  t»  miW^"**" 
organumi>  iiitniilucrd  into  the  bladder  IVoin  without,  during  ibi-  into  of  inHlf 
mentr  for  iiu'nncc,  I'r  to  the  action  of  an  unnrganixcd  iVrmrnt,  tccreted  a 
parerillv  by  ihe  wall*  of  the  bladder. 

■;  406.  Ahnfrmnl  foM*litnfnlt  of  urine.     The  ttructunil  clemcola  found 
the  urine  undrr  various  drciinixtam-i-Tt  tin-  blood,  pu*  and  muciiR  corjiuwil' 
epithelium  from  the  bladder  and  kidney,  and  tipeninitoxun.     To  thewi 
be  added  the  n>-c«IIc<I  "  rnet«  "  which  are  eithrn*  "  e|)itliolinI  casts,"  thai  Is 
■ly  cyUixlere  of  ntore  or  \c»  ultvml  upitlieltnl  celle  »lied  frura  tlie  tutiules. 


( 


I 


THE  SKOBETTOIT  Or   tTItlKK. 


■MB 


»lnicturrli^i).  "tibniiDua"  caola.  wliich  an  cyliiiden  of  ]>cciiluir  nmti-r'uil 
nxfukle^l  in  th«  liiiuiim  uf  ibe  lubulea;  ibe  exact  nature  of  thb  mati-rial  ia 
nt  {ire»ent  a  iiwiler  of  doubt ;  il  b  uut  alwitya  lh«  ttime,  but  apjKwn  mA  to 

f  tibriu. 

The  moat  ctiintuou  aix)  iin[Kirtaiit  abnurmal  coiMtitueiitA  of  urinv  urv 
umni,  giving  ri*c  to  HltHiniinuri*,  ami  twjar,  giving  rise  (o  glycvuria  or 
<liitb«Kv».  The  Mliiblu  pmlciili!  giMicnilly  )i{Kik<;n  of  m  "  albumin  "  id  the 
iirliii-  differ  in  liifftront  cnnv*.  The  exact  tletvnnination  of  iheir  nature  i*  a 
niitttcr  of  wimi;  (llfliciiUy,  olnci-,  m  wc  have  «cen,  we  have  in  (litfcreiilJnUug 
thi-  viiri4)ti»  proteitU  to  trust  laigely  to  their  buhuvior  >■■  reganln  precipiUtion 
iipun  the  H(l<liii(iii  of  c-erloin  MHoe  boilim  ;  ami  the  ))m>enco  of  mliiM  bodiM 
in  llir  natural  tirliii-  introduce  complication)).  It  wotili)  appear,  honever. 
that  ibc  proleitk  umially  prment  are  scrum-nlbumtn  and  glomiliii ;  the«e  are 
not  however  as  a  nile,  if  ever,  preecnt  in  tbo  Mine  relative  pruporliona  M 
in  blood-plasma ;  and  eitlier  the  one  or  the  other  may  be  pment  by  ilM)lf. 
A  form  of  albumoee  (i  20$)  called  Itemi-alh'imot,  is  Komeiimcs  found,  and 
and  indeed  probably  verr  many  distinet  kinds  of  proteids  are  from  time  to 
time  pretem.  If  egg-albumin  be  injected  into  the  blood  it  appeat^  in  the 
urine  as  egg-albumin,  and  peptone  similarly  injected  apjMara  ae  peptone. 

The  sugar  which  is  found  in  the  urine  of  diabetee  U  undisliugiii«hal>l>> 
from  ordinar7>'  dextrose;  but  whether  it  is  absolutely  identical  with  that 
Ikody,  or  wlteiber  the  sugar  in  all  eases  of  diabetic  urine  is  exactly  the  same, 
caiiiio*  perhafie  as  yet  be  n^anled  as  definitely  S6ltl«l. 

When  blfiod  is  mingled  with  urintt  in  tbe  kidney  and  in  the  urinary  |)as- 
sages  the  citnutiiuents  of  the  former  an.\  of  course,  added  to  tliowe  uf  th« 
latter;  and  whim,  bh  Mimi-tliiiej*  hHp[H-ii»,  chyle  fn>ni  the  lavteals  ntakra  il« 
way  into  the  kidni-yv,  the  urine  contains  the  fats  and  other  ccnstituentit  of 
chyle.  Fal^  h»wcver,  may  be  present  without  the  urine  being  distinctly 
"  cbrlous." 

Cliolosteriu,  bilc-acidH,  biIi.--]iigincnU,  luid  one  or  other  of  a  large  niioiber 
of  bodica  arising  from  a  dinonhn^l  mrtaholinni  of  lite  body,  such  as  leudn, 
lyrneln,  acetone  i  in  case*  of  dialxTies),  oxitlic  acid,  taurin,  cysiiu,  and  many 
oihen  ant  alio  found  more  or  kn  rreqiienlly :  some  of  these.  inde«-d,  luive 
bein  regarded  as  iitmnal  eonsUtiient*.  Itcsiidea  these  the  nrinu  «erves  as  the 
chk-f  ebanuel  of  elimination  for  vurioii*  bodira.  not  proper  constituents  of 
f(MM],  wlm-h  may  hapinn  to  have  been  taken  into  the  system.  Thus  various 
miiieraiis  alkaloids,  mits.  pigmentary  and  udoriferouR  mattera.  may  be  passed 
unchanged.  Many  «(ibetances  thus  occasionally  taken  undergo,  however, 
changes  in  ^uasing  through  the  body :  the  most  important  of  thew.  since  tl»c 
changes  wbich  th«v  undergo  throw  light  on  the  meubolic  procesece  of  the 
body,  will  be  considered  in  a  eueceeding  chapter. 


Tbe  SscRenoN  op  UBnre. 

§410.  Tlie  facts  nhich  we  have  Immi  in  a  preceding  section  concerning 
the  structure  uf  thf  kidufy  have  Hhowii  iia  that  that  organ,  unlike  the  oUier 
sti'R^ling  organs  which  we  have  hitherto  studied,  oonslsts  of  tnu  parts,  su 
distinct  in  structure  that  it  seema  iiii]i(«ible  to  mist  lite  conclusKm  that 
ibtir  Aioctions  aru  different,  and  thai  tlie  nu'chaniMU  bv  irfaiuh  ibr  tiriiw  is 
BKVMtd  b  of  H  doiililc;  kind.  On  the  one  hand  the  tiibnli  uriuiferi,  with  their 
eharvderistie  epillielium.  seem  nbviouidr  to  be  actively  Hording  Mructtircs 
oompnrublc  to  tbe  Hireling  alvenli  of  thi^  Milivary  and  other  glands.  On 
the  otln-r  hanil  iIh-  Malpijiliinn  <-a)i*iil<'s.  with  thi^r  gluiiieriili,  are  organ*  of 
«  pMuliar  nature,  with  an  nlmwt  iu«igniliciiiittpitlielinm,and  their  structure 

41 


630 


TllK    KLIUlNATtON*    OT    WASTS   PII0DU0T8. 


irrrttnibly  flUfffCCBtolbatthov  acl  rnlher  its  whiil  idav  bocnilet)  in  ii  jjeuprnl  wmj 
a  lllierinf;  lliaii  tu  a  Irulj'  secreting;  niei'lianisRi.  ilenoe  liiu  nri.'^ii  rJie  ri«« 
which  frtijuentlr  bears  Ihe  ounic  of  SitwiDao.  aiiim  he  whs  lh«  tint  Ci  ]tul  ii 
fi>rwur>l,  timi  reruin  coiwtitueniB  only  of  (be  urine  iir«  eetn-itvl  slVr  Uir 
liwbioti  i'(  >ilh«r  settrccing  glands  by  ibe  Mbuli  iiriniferi.  and  that  the  rort  iiT 
(h«  i.i)Di<litu«utA,  iocluding  a  great  deal  of  the  wuterwiih  such  highly  •oluU* 
mmI  (liBiiaible  wlu  as  |>r«'xisl  iu  adequate  quantity  in  the  hliKxl,  iiiT,  n»  k 
wera,  filtered  off  kv  lii«  glornoriili  of  the  Mal|UK'>iAU  ca|wile«.  Wo  ahall  M 
later  oil  rciunn  tn  clouht  wliiititcr  we  are  justified  in  applying  the  t«nD  "  filta- 
tioD,"  whicli  )iiw  a  tli-(ini(i>  phyMcal  lueauinfc.  M  the  proeeM  1>y  which  water 
and  oth^r  tiiilR'tiuKX'"  |>iu«  fh>Ri  the  bloodv^M-ln  of  llie  glonivruliw  into  tk* 
liitncii  of  tlic-  tiibiilc :  fur  thiit  ]>rt>ceM  in,  ait  we  ahall  find,  pcctiliar  and  com- 
plex. But  mich  a  d<Miht  n«Ml  liol  prevent  u*  frnm  rvrcwnizini:  that  the  wbole 
art  of  Bccretion  of  urinr  ooimkUi  of  two  purl*,  one  of  wliii-h  is  much  more 
cloeely  depeodeot  on  the  Sow  of  hlooil  thnnigh  the  kiihii'y  than  is  the  urdi- 
nary  proccae  of  aecrotion  auch  a»  han  bitlMirto  vome  hcfiro  us.  and  aaMber 
part  which  seenii  to  bear  ihe  anrac  relation  to  the  flow  of  blood  as  does 
ordinary  secretion. 

That  the  work  of  tti«  kidney  is  to  an  unusual  degtM  dependent  on  tbt 
lion  of  blood  ihrou^b  it,  secnii  FUgpsted  by  tbe  vascular  arrangenK-nlfl  ;  for 
tbcao  are  extremely  favorable  to  a  full  anil  rapid  streoiui  of  blooil  iJirouicli 
die  organ.  The  abort  and  relatively  broad  renal  artery  conwa  off  direct 
from  the  abdominal  aorta,  where  tbe  blood-preasure  is  extrenielr  high  ;  the 
ntnal  vein  opam  directly  into  the  vena  cava,  where  the  blooa-pnwtirr  if 
extreuidy  low.  Between  tbe  niouth  of  the  renal  artery  and  the  mouth  of  the 
nmal  vein  tlie  differeuioe  of  preaaure  ts  very  great,  indeed ;  and,  na  we  have 
Been  in  treatin^iof  the  vmu-ular  system,  it  is  thedll^reneeof  preMtir«  botwwa 
two  [Kiints  of  tltcvajiciitnr  tract  which  l»  the  actual  cause  of  the  flow  of  blood 
Irom  tbe  one  point  t<i  the  other.  The  difference  of  |if«isure,  indcfHl,  which 
drivf*  the  hliiod  ibmuf^h  t)i«  linittetl  area  of  the  kidney  is  tlw  Minic  difference 
of  praeun^  which  driv^w  tlio  hliMxl  along  the  abdominal  aorta  down  both 
lea  back  again  to  the  vc-na  cava. 

This  Itc<'  and  abundant  supply  of  blood  is  regulated,  is  either  increased  or 
diminishcii,  according  to  tli«  noudsof  the  moment,  by  (he  vasomotor  system; 
this  is  shown  by  experimental  niid  other  results,  which  it  will  \w  pn>f!t«hle 
to  study  in  some  detail.  Before  entering  into  these  details,  however,  it  will 
be  well  to  call  attention  to  the  fact  thai  when  vasomotor  events  modify  (bt 
flow  of  blood  through  an  orf^'ao,  they  produce  their  efleets  in  one  diriKlioo 
or  another  by  workin;;  on  arterial  blood-preMUre.  Thus,  as  we  ahall  me. 
when  stimulation  or  section  of  a  nerve  inoreasea  the  blood  through  tho  kidney, 
it  docA  so  by  inereadiuK  the  premure  in  the  small  vcmcIs  of  the  kidnev,  iot'lud- 
ing  the  eapillary  loojis  of  the  glomeruli.  In  »uch  a  caw  the  wnlls  of  tbo 
glomerular  loops,  tlinnigh  which  the  pawage  of  materinlii  t4>  form  >!|Hirt  of) 
the  uriite  takea  place,  are  subjected  to  two  iufluenc«s — on  the  one  hand  to  ■ 
AiUer,  more  rapid  flow  of  blood  peat  them,  and  ou  the  other  to  an  increwe 
nf  the  prewuTv  which  that  hlood  as  it  posees  along  exerts  on  them.  We 
ahall  )ia\-e  snihstHpieiitly  t»  iliscusa  tbe  share  taken  by  (hew  two  influences  in 
determining  luid  niinlifyin^  Uie  passage  of  material  throu^jh  the  walls  of  the 
glouu-rular  liio])i< ;  and  this  will  bear  on  the  quwtion  of  fillnition  to  which 
wo  have  above  alluded;  but  fir  the  pnv^nt  it  will  lie  convenient  to  deal 
with  the  eflfeet«  of  variation  in  blcml -pix-Mure  apart  fo>ni  this  Eccondary 
qucMiou. 

ji  111.  Thf  vatamator  merhattunu  of  lh«  titlMy.  It  may  he  shown  experl- 
nionlally  that  tlie  kitlney  is  supplier!  with  n  vasomotor  mcchanifun  as  well- 
developod,  IwhajH.  ii:>  tlwt  of  any  vtlter  jmrt  of  the  bi>dy      By  means  of  a 


'hKTION  or  UBI!fB. 


681 


mmliiicntiiii)  of  die  |^elh}-«m<>gmj>li  (Pi^  Io.i,  ISti),  we  cma  rwdUy  ohwrre 
tbc  vnriaii,nis  wlikb  uko  J»l«c«  in  tlie  vuluiue  of  tli«  kidn«j. 

The  inslrninent  coiubla  of  two  iisrtii.  one  of  which  (Fie.  155),  wllod  thi>  oaro- 
in«I«r.'  U  >pplip<)  to  tbe  orgao  about  to  be  «ludl«d.  while  lh«  other  I  fit;.  l-'SlI), 
c«lle.J  Ihr  oii.xiicrapb,  i*  Ibe  ncordtur  iwrt  of  the  appitjatiu.  Anjr  (limlnution  in 
tb«  volume  uf  lli«  orjpin  (Fij(,  IM.  £).  kidavy.  iip\rea.  tic.,  h  the  caee  m*y  be. 
diiniais)ieslli«pNi)*uru  AnlbcDiiiilin  th«<clllllIib(^^<I;llOlIl«oftbe0ui(]in  thecl»m- 
b«r  ^(Fig.  130)  Mcoidlnglj  jmumm  ihroueb  lh«  cube  A'lFig.  1S6)  &Dd  liie  lube  T 
<Flg.  15.^)  to  the  diatnbera:  the  pbton  j^kccordlnglv  faWa  aod  iritb  it  the  lerer 
/r.    Simttuly  ma  iocroiwe  in  A*  volume  of  the  orgau  cauiee  tbe  lever  lu  riie. 


a 


^ 


I 


Rkhal  QncMum.  (Seen  Id  nMUon.  Monl-ilUcnunnMllc.  i 
f\  r,  tomI*  aiiil  nama  Imtwlilod  ui  Ui.  otc.  raloriiiR  tilla*  atoratn:  ft,  C<  auil  r.  (^ 
'<»ulw  *»i  lancr  niaUil  mimiln  nnwml  UfvUwrbj'Ui*  tfw  AaiiJ  bnlillnf  Mmm  lti(ai)lui(dE« 
aribauioiiiboiMo  jr.wMchappUM  ltMiriollwiiirIlu«arih(Udii«ir  and  fimuvtih  tbcmeUlnp 
Mile  two  dMiotoixa  uul  B,  una  ol  wbtcib^Jti  Iteloaol  b;  a  pliur  dllliii;  iho  aptiiJDit  It,  hLIIu  ib« 
oUier  (n)  eamniiatnUM  lir*  lube  T*  wlib  ibo  nKmliiig  liiMiuuMnt,  The  otbrr  op«nlna.  CimbM) 
bi  «taa*4  br  a  omU  tap).  U  IMiihe  pori"^  «<  illUni  Uw  ohaiuber  a  wKb  mrm  all  alto  tbo  KUiwr 
haatMM  itewd  la  UmIok,  Ih*  oUwr  i-hainba  JI  baTlaii  been  |<n>Tioial7  laitlj  UM.  tbaquasUl)' 
InlmdDcaA  lalaUitaiiianiUniiitua  ti«UMor  tbaUdner. 

The  volume  of  tb«  kidnoy  tunj  bt  incrvased  l>jr  a  swelling  of  itif  ooti8titu<'iit 
cells  sod  otli«r  structural  ckmindt,  br  an  aucumuUtion  of  lymph  in  iu 
1vinph-«wow,  and  by  a  i)ixt<:iitioii  of  it»  ltlti<Klv»iM)l».  Compared  with 
lite  tliira,  ihe  two  former  ciiuecs  are  in  lu-jillh  »o  liiMgniHcunt  M>d  iiroh- 
lematical  (hat  thoy  may  be  disrvganltxl.  Purlhcr,  the  diatDDtion  of  ihe 
binodveaaeld  will  in  graorul  de|>end  on  the  constriction  or  dilation  of  the 
renal  arterim  and  tbdr  raaiilicatioaB,  for  duWntioii  duo  to  venous  obalruction 

Kms  Mmi^  bulk. 


es2 


THE    ELIMINATION    OF    WA8TK    PB0DCGT8. 


win  only  occur  in  8pecial  cases.  Hence  variations  in  the  volume  of  the  kid- 
ney may  be  taken  ai;  a  meaaiire  of  variations  in  its  vascular  supply — incroK 
of  volume  indicating  dilated  renal  veseels,  and  decrease  of  volume  iiidicatiii( 
conBtrictiou  of  the  renal  vessels. 


Fio.  IM. 


6khi-[<iuirahii*tiij  SKCT]O^A;■  Vrtw  or  ONi  im>rai-i<.  [Half  nHluml  bIz«.> 
A',  tiibt  connecting  limninipm  wlih  unciiiiictiT  -,  D.  iilsi"ii  Uniting  on  oLI  contained  In  (tae  niftr 
U;  Itiv  oil  1h  prvvuiitcd  fixiDi  evcapliij:  by  1h«  wlv  of  flu-  pin^u  by  ihc  delicate  Heilble  menibt«tw£ 
whirh  iloen  not  liitcrriTC  uilli  (he  iiinvticictit.^  of  I  lie  plilon  :  Jl.  ri'OjrUiiig  lerer  coDUccled  with  ilie 
pitluu  bf  a  necllc  fi  innslnG  tbroiigh  Itie  gulilee  F.  f.  fin-  i^tieu  c  l>.  for  ihe  purpoHe  of  clamping 
the  edKeiiKbe  membmne  beineeii  the  two  rlntt-sbuiicil -iiiniivi'i  bi  ,V,  wlillu  ihc  itlde  tubt  L  li  rortlie 
pnrpo«B  of  lillm^  Ib^j  in^lrunivnt. 

When  by  means  of  the  instrument  jtiat  Jeserilied  »  tracing  is  taken  of  the 
volume  of  a  kidney  in  what  may  be  considered  a  normal  condition,  some 
such  result  as  that  shown  in  Fig.  li>7  is  obtaiueil. 


Fir.,  l.-J. 


BL  0  u  0 


P  n  L  ^  z  u  p,  £ 


KfDNcr      CUBVE 


Bl.Oui>-PRE(t<ri(E  TraI'INu,  ami  Ci  Hve  rtioM  Henai.  ij><.'<»it:TEU.    i^ntnml  size.) 
The  Lilood-pretture  abwliwiL  line  hut  been  mlKil  'l.i:'  cm.  ilbe  lU'riinL  mciilnni  blood. preoEiu^ 
bavtng  been  115  mm,  Ilg.).    Tbe  ilme-cuTve  |(lviw  lriiL-TrU['llon^  rvcurrln^  t-very  ibTri-  efooads. 

The  volume  of  ihe  kidney  is  seen  to  be  so  delicately  responsive  to  chaagea 
in  the  mean  arterial  pressure  that  the  curve  reproduces  almost  exactly  ■ 
blood-presaure  curve,  showing  not  only  the  respiratory  undulations,  but  even 


TUB  tiKCRETION   OF   t'fllKK. 


fi83 


I 


I 


I 


I 


I 


I 


tlic  rite  nii<)  full  due  ii>  Uie  imitvidiial  li<'arl-)>f!nU.  With  each  ri*e  of  tneaii 
iirtrriat  prcmiirf  nv)re  blood  iit  driven  into  ihn  roiiiil  v<u»i:U  and  the  IcidnHy 
HWclU;  with  I'licU  I'all  of  prx^triiirL'  Ikm  l>I(i';d  i-iiti'r;<  and  llir  kidney  shrink*. 
On  other  trectngw  tukci)  in  thi>  >uini«  wnv  may  (dlRii  he  ■cim  (not  (hown  in 
Fig.  l'>7)  the  nidi;r  viiriAti<.)nit  oiminnoDiling  to  the  Tfiiiihr-H<iring  cnrvc«; 
but  it  will  hv  iiWrviil  thiii  in  ihit*  the  kidiioy  shrink*  with  the  ri»;  of  iirmc 
Dure  Mid  BWvlU  with  1\k  fall,  F»r  lut  w«  hiive  socn  (^  3^:i}  tht^  rise  in  thu 
Tmoho-Hrriiig  nndiiliitii>n  it  due  to  an  AUEmetXation  ofporipherid  rosi«timce 
c»iw»l  hy  th«  ran>>triclii>n  of  miniito  nrlents;  and  this  constriction  occiir«  in 
the  kidney  lu  clMwlutre;  the  reniil  arlcriolM  Uikc  ihoir  »hnre  in  nrodiieing 
tb«  reeiiU,  mid  iu  oonseniieuue  of  iheir  tonjtriclion  the  kidney  shrinW.  Simi- 
larly tiK  relaxation  of  tne  renal  veig&eU  contribules  to  bring  about  the  sequent 
All. 

i  412.  In  the  course  of  a  discitiHian  in  an  earlier  part  of  thia  work  (S  171) 
on  the  local  and  ((eneral  elfccls  of  arterial  constriction  and  dilalii>u.  we  saw 
that  the  local  blao<i-i>rwdure  in  and  flow  of  blood  thriMiijb  the  capillaries  and 
other  minute  vea»eb  of  thin  or  that  vaaoular  area  may  be  inemaieil — 

1.  By  an  increase  of  the  ^ueral  blood -preaaurA  bruuKht  abmit — {a)  by  on 
incrcHMnl  fonw.  frtniuency.  etc.,  of  the  heart'*  heat,  (b)  by  thr  i.-onstrititiou  of 
Ike  Mnall  arteries  siijiplyinK  ari.-tk>  other  tlian  the  aiVA  !»  <|ii<»<tii>n. 

2.  Br  II  rwlnxatinii  of  the  nrlisry  (ur  arteries)  Aupplving  the  ar<.ti  ttMdf, 
whirh,  whilo  diminiHhtn^  the  |ir«w«ure  in  thf  artery  itwcif,  incn-iww  the  prwt- 
sure  in  the  cnpilhirii*  iin<l  »mntl  vmou  wliirh  the  artery  ifupplicii.  It  nucil 
hardly  W  add<->l  llmt  thii  local  n^Uxnlion  muihI  uoi  lie  uccomjuuiiod  by  a  loo 
great  dilMion  elsewhere. 

The  tnnK'  lo^al  Idoud-pretMiire  and  flow  of  blood  may  similarly  bo 
dimiuitheit—' 

1 .  By  a  constriction  of  the  artery'  of  tJie  nr«a  itself  fand  it«  branches), 
which,  while  incn^aini;  the  prmsiire  on  the  canlinc  side  of  the  artery,  dimin- 
islws  the  iiri«sure  in  the  capillaries  and  vi.'ins  which  are  supplied  by  the 
artery.  This  ajfain  must  not  be  accompanied  by  a  too  Rreat  cunsiriction 
elsewhere. 

2.  Bv  ft  lowering  of  the  tjewral  blood-preasure,  brou;>ht  about — (n)  by 
diminished  force,  etc.,  of  the  heart's  beat,  (6)  by  a  jteneral  dilation  of  tba 
nmnll  arteries  of  the  botly  at  lurjre,  or  by  a  dilation  of  vascular  arena  other 
than  the  area  in  question. 

Applyiti;i;  tfawe  considerations  Vt  the  bloodvesseU  of  the  kidney,  we  should 
enpoct  tu  fiiul  the  follouiiij;  : 

A  rise  in  g«i«ral  bloud-presanre,  and  that  mean*  a  rite  vf  preMure  in  tlie 
abdnmioal  aorta  at  the  mouth  of  tbi-  renal  iirlrrr.  will  cnusK  a  greater  flow 
of  blood  ihfoueh,  and  au  an  expansion  of  the  kidney,  provided  tliat  the  renal 
nrteriiw  ihenivelvm  are  n'>t  umliily  c'lnstricted  at  the  same  time.  This  is  well 
sh«>wn,  IU  we  have  settn,  in  the  curve  tfiven  nliorc,  where  the  incriMM  »!'  prm- 
Hurvdaetowicb  bi»rtdMrat,M  well  il*  ihnt  due  to  ench  n-«pirali>rr  inovcmcnl, 
l>uing  of  onnlral  origin  and  n<it  due  to  nrUTial  ci>n*iriction  and  being  unnc- 
oompunieil  by  any  oompen-ialin^  oonstriclion  of  the  renal  artery,  leada  to 
cxnanaion  of  the  kidney,  tlial  is,  to  u  greater  flaw  of  bluod  through  the 
kidni-v, 

If,  liowever.  tlio  rise  of  gtriieral  blood -preMti re  be  due  to  events  which  at 
the  same  linxt  canse  a  eon«triction  of  the  renal  arteries,  tJie  flow  through  thu 
IcidiH'v  may  not  only  not  be  increased  but  even  be  diminished  ;  the  kidiwy 
may  shrink  instead  of  expanding.  Thus  tf  dyspnoea  bo  brought  about,  M 
by  stopping  artilicial  rcepiraiion  during  an  experiment,  the  kidney  at  once 
shrinks ;  the  too  venous  blood  xtimnlaieri  the  vasomotor  centre,  and  probably 
aba  by  direct  action  on  the  bloodreMeb  leaib  to  a  KCneral  arterml  constrio- 


634  THE    ELIIIIXATION'    OF    WASTE    PRODUCTS. 

don  and  so  to  a  riee  of  blood-previire;  but  the  renal  vcskIb  are  involved  is 
this  constriction,  so  much  so  that  their  constricted  coudition  more  than  coun- 
terbalances the  general  rise  of  blood -pressure,  and  less  blood  flows  throng 
the  renal  vessels,  ^o  also  when  the  medulla  or  spinal  cord  is  directly  stinii- 
lated  hj  induction  shocks  (the  animal  being  under  urari  so  as  to  eliminate 
the  com  pi  i  cut  ions  due  to  contractioas  of  the  skeletal  muscles)  the  renal  vei- 
sels  share  so  fully  in  the  arterial  constriction  which  results  that,  in  apite  of 
the  great  rise  of  mean  pressure  which  is  induced,  leas  blood  than  normal 
passes  through  the  renal  vessels,  and  the  kidney  shrinks.  Or  if  tbe  abd<HDb 
nni  splanchnic  nerves  be  stimulated,  since  as  we  shall  see  these  carry  vaso- 
cuuBlrictor  Hbre.'^  for  the  kidney,  in  »pite  of  the  rise  of  blood- pressure  which 
folluns,  the  kidney  shrinks  on  account  of  the  great  constriction  of  the  r«iial 
vessels. 

On  the  other  hand,  if  a  rise  of  blood-preasure  be  for  any  reason  not  accom- 
panied by  n  compensating  constriction  of  the  renal  arteries,  that  rise,  whether 
It  be  brought  about  by  general  constriction  of  arteries  other  than  the  renal 
or  by  an  increase  of  the  canliac  delivery,  causes  the  kidney  to  swell,  showing 
a  greater  flow  of  bloixi.  Such  a  conaition  of  things  may  be  induced  by 
section  of  the  nerves  of  the  renal  plexus,  whereby  the  paths  of  all  vsso-^»&- 
strictor  impulses  to  the  kidney  are  blocked.  After  this  has  been  done  a  riee 
of  general  pressure  whetiier  by  dyspntea,  or  by  direct  stimulation  of  the 
spinal  cord,  or  by  stimulution  of  the  abdominal  splanchnic  ner\-e8.  leads  to  ■ 
greater  flow  through  tbe  renal  vessels  and  an  increased  expansion  of  tbe 
kidney. 

A  rise  of  generiil  bloo<l- pressure  then  may  be  accompanied  by  either  s 
shrinking  or  ii  sivelling  of  the  kidney,  by  either  ti  greater  or  a  lesser  flow  of 
blood  through  the  kidney,  according  to  the  con comi Cant  condition  of  the  renal 
vessels;  or,  indeed,  may  under  certain  ti  re  u  instances  be  accompanied  by  no 
change  at  all  in  the  renal  circulation,  the  local  etlects  exactly  counter- 
balancing the  general  ones. 

Conversely,  in  a  similar  way,  a  fall  of  blood-pressure  leads  to  a  lesser  flow 
through  the  renal  vessels  nud  a  shrinking  of  the  kidney  unless  it  be  accom- 
panietl  by  a  dilation  of  the  renal  vessels  out  of  proportion  to  the  general 
fall.  Thus  when  the  spinal  cord  is  divided  below  (he  medulla  the  fall  of 
general  hlood-pre-wurc  is,  as  we  have  seen  (§  ll'A)  very  marked,  being  due  to 
an  iibolitiim  for  the  time  l>eing  of  wonted  constrictor  impulses.  The  pres- 
sure in  the  aorta  falU  rapidly, and  nt  the  f^ume  time,  owing  to  the  more  open 
pathway  through  ilic  region  of  (leriphcral  rcwstjince  iu  the  body  generally, 
the  pressure  in  the  vena  cava  is  increasi-'d  :  the  dilicrence  of  pressure  between 
the  mouth  <jf  Itio  renal  artery  in  the  aorta  and  the  mouth  of  the  renal  vein 
in  the  venu  cava  is  so  largely  reduced  that  in  spite  of  the  concomitant  relaxed 
condition  of  the  renal  vessels  themselves  the  flow  of  blond  through  the  kiiiney 
is  largely  diminished. 

It  will  of  course  tie  understood  that,  the  general  blood-pressure  remaining 
the  same,  the  flow  through  the  kidney  will  at  once  be  im  the  one  hand  in- 
creased by  dilation  and  on  the  other  decreawd  by  constrictiim  of  the  renal 
vessels  themselves.  The  constricted  or  dilated  condition  of  the  renal  vessels 
can  by  themselves  produce  hut  little  vHect  on  the  pressui-e  either  in  the  aorta 
or  in  the  vena  cava ;  and  the  dillerence  between  the  jircpsore  at  the  mouth 
of  the  renal  artery  and  that  at  the  mouih  of  the  renal  vein  remaining  the 
same,  the  more  o|>en  passages  of  the  dilated  renal  vessels  must  lead  to  a 
liiller,  and  the  narrower  passages  of  the  constricted  renal  ves3i.>ls  to  a  scantier 
flow,  through  the  kidney. 

§  413.  By  means  of  the  oncometer,  watching  the  shririkinc  and  swelling 
of  the  kidney  and  thus  jutiging  of  the  flow  of  blow!  through  it,  the  results 


TRE  SKCItETION  OP   tTRIXG. 


nan 


I 

I 


t 


being  nlwiiys  interpreted  with  rellerenoe  to  th«  gejieral  blood-preaaurv  on  the 
llttee  of  tbe  nbove  discuMiioo,  ihe  |iatlia  of  vaeoiuotur  imptileeB  to  the  biilitey 
baT«  b«en  a))|)roxininlely  ninde  out.  Vaso-constrirlor  61>ns  fur  the  kidiioy 
are  Mpi>lied  from  nbat  we  have  iirevioualy  (^  UVJ  and  eUewher«)  spoken  of 
OB  ibe  Taao-ioDHtriclor  regiim  of  the  spinal  oord.  They  ii-»ue  fn>m  Uie  vpiniii 
mrd  bv  the  aolerior  nx>ta  of  a  large  number  of  lfaS~3}>iDat  iiervea  tiikLug 
ori;[ii)  troni  thia  region,  and  may  be  tncml  (in  the  dog)  iu>  bigb  np  an  the 
MXtb  diintal.  u  few  [lerbujM  even  to  tbe  fourth  <)oniul,  and  iw  Kiw  <l<>wn  tu  the 
aeooud  lumbur  (lourth  lumbar  ir»iily  lhirt<t;n  nerves  be  (^xinusl  iw  ilorMiI) ; 


but  im»t  necm  to  imm  hy  tbe  elevcJuli,  tweinii,  and  thirleejith  dunml  iicrvea. 
;h  tne  eorm  poll  dill);;  )2;nii);lin  nf  llin  upliuicliiiii'  (Dvinpatlietic) 
cbniii,  ihi-M;  tilin-x  reuch  the  »[iliir  {ilesiifi  mid  thiix  tlie  nrual  plexu*  )>v  the 


I 
I 


abdoiiiiiiHl  «{iliiTK'liiiii-  Rurv«;  ih'iu',  howuvrr,  ei>iniHg  from  »iiiiu  of  ihv  lower 
nerves  ■p|>nn'ntly<lo  not  cDiiinhuio  lo  the  KpImK'bnic  nerve,  but  takeaMt[>a- 
rale  rounte.  Onlrifugal  Miniulatii>n  of  ih'rse  anterior  roola  produces  shrink- 
ing of  the  kidney,  ah  the  more  marked  and  diHtincl  in  the  ca«o  of  the 
elevMitli.  twelfth,  and  thirteenth  dorwd  ruot«  because  the  oHecl  on  the  kidney 
b  tlMfl  not  M>  much  masked  by  vasomotor  effects  on  other  organs,  t^timiiia- 
Uon  of  the  higher  roots  also  produces  shrinking  of  the  kidney  but  leas 
toarked,  »inee  In  these  caaes  the  stimulation  bears  at  the  same  time  largely 
on  vaso'constriclor  fibres  for  other  abdominal  iirgvns.  and  so  by  miging  the 
l^eral  blood -preHauiti  tends  l»  neutralise  the  local  elieel  on  the  kidney. 
And  even  tbe  very  decided  shrinking  of  the  kidney  which  reaulu  from  the 
etimnUtion  of  tiie  mlauchnio  tjunk  itaelf  is  lean  than  would  take  place  if  the 
Himulfltion  atli;cled  the  veK«e]s  of  llifl  kidney  only. 

ji  414.  We  stated  in  j  16^  that  liy  tbe  mediod  of  slowly  repeatetl  rhytli- 
uical  aiiniuiation  the  prmenee  of  vaao-dilator  fibres  in  tbe  sdatie  nerve 
niiKht  he  detecteti,  though  tlicM  are  largely  nixed  with  vasoK^onstrictor 
fibres;  and  sliiw  rhylhiuienl  vttniutatiou  of  tfiv  luiterior  rooU  of  the  ahove- 
roeuiiiiued  lower  dorml  iierveM  l<wls.  not.  an  don>  ordinary  rapidly  inter* 
rupted  stimulation,  to  abrinking,  but  lo  awelling  of  the  kiitn«r,  showing  thnt 
iheae  mota  euoinin  vaaodilaior  tihrw  a«  well  lu  viwi>-consirietor  lit>re«.  The 
higher  (anurior l  rot)!*  iilim  appear  to  contain  some  renal  vaeoililalor  Hbrm; 
but  i)k-  cSiKl  of  etimulatiii);  them  bv  tiie  slow  rhythmic  mctlioil  i*  more 
m«*ke<l  by  a  concomiliuit  dilation  o^  the  veaada  of  the  other  abdominal 
ofgiuM,  the  roots  in  <{uest4on  eonlainiiig  vaao-dllator  as  well  as  vascMWDalriotur 
fibres  for  th<«e  organs;  this  leads  to  a  fiill  of  genoraJ  blood-preaauiwirhonby 
the  tendency  of  the  kidney  lo  swell  is  oounteracted.  As  far  as  can  M 
■scertainei)  at  preaeni  tbe  paths  of  tbe  renal  vaso-ditator  libnis  are  similar 
lo  iboee  of  tbe  renal  vaso-coustrictor  libroa. 

Tbe  kidney  then  is  well  aupplied.  espedallv  tiirougb  the  anterior  roola  of 
lite  elevenili,  twtilflh,  and  ihirleenlh  dorsal  nervea,  with  vaso-coustrictor 
fibrw,  anil  is  alui  xupplied  with  va^ki-dilator  flbree.  Borne  reeulls  have 
aeemed  to  .ihow  that  the  libn-s  passin;;  along  the  roots  of  one  side  of  the 
•ninal  eortl  guvi-m  ibe  veieeU  not  only  of  the  kidney  of  the  same  fade,  but 
UM  lo  a  irvriaiu  extent  of  the  kidney  »f  tn«  otber  sule ;  it  seenia  doubtful, 
bowtver,  whether  ihi*  i*  really  thi-  civn: 

There  is  no  Mtisfai-tory  evideiicr  that  the  vagu:>  nerve  of  either  side  oon- 
Uline  any  vaaomotor  film-x  renchiiig  the  kidney  (sec  S  400). 

Ji  418.  It  is  i>bTioiin  (hen  that  by  niejiu*  of  this  vasomotor  mechanism  the 
flow  of  blood  through  the  kidney  is  governed  by  the  oeutral  nen'ous  system 
in  sucb  a  way  that  nlTerent  impulses,  started  in  this  or  that  region  or  lur- 
face,  and  (laSEine  up  lo  tbe  central  nervous  system,  may  lead  cither  to  con- 
atriotion  or  lo  dilation  of  tlte  renal  vessels;  and  to  sueb  actions  of  this  kind 
we  ahall  preaeotly  rMuni.     Meanwhile  we  wish  to  udl  attention  lo  tbe  fact 


J 


58fi  THE    ELIMIN'ATIOX    OF    WASTE    PRODUCTS. 

timt  tbc  volume  of  the  kiilnev  is  remarkably  sensitire  to  chemical  chuga 
taking  place  in  the  blood.  1?be  injection  into  the  blood  of  even  a  small 
quantity  of  water  causes  a  transient  shrinking  of  the  kidney  followed  br  a 
more  lasting  exjtansion.  The  injection  of  urea  and  some  other  diuretics 
produces  the  same  cfTect  to  a  more  marked  de^'ree,  leading  especially  to  ■ 
swelling  which  lasts  fur  some  considerable  time,  while  the  injection  of  normal 
saline  solution,  and  especially  of  such  diuretics  as  sodium  acetate,  causes  an 
expansion  from  the  very  lint,  the  primary  shrinking  being  abisCDt.  It  it, 
miireover,  worthy  of  note  that  these  ettects  of  diuretics  and  of  chemical 
changea  in  the  lilood  are  observed  even  after  all  the  renal  nerves  have 
apparently  been  completely  severed.  Hence  the  changes  in  volume  canaed 
by  the  ])re8ence  of  these  substances  in  the  blood  must  be  due  to  the  sub- 
stences  actiug  either  upon  some  jieriphoral  vasomotor  mechanism,  or,  evea 
more  directly,  on  the  bloodvessels  themselves.  It  may  he  added  that  they 
will  produce  considerable  effects  in  the  kidney  itself  without  appreciably 
modiiVing  the  general  blood- pressure 

S  416,  If,  while  the  kidnev  is  iu  the  oncometer,  and  the  various  experi- 
ments on  section  and  stimulatiou  of  nerves  and  the  like  are  being  carried 
on,  a  cauula  be  tied  in  the  ureter,  the  secretion  of  urine  may  be  n-atched  at 
the  same  time.  It  will  then  be  seen  that  the  How  of  urine  through  the  end 
of  the  canuln  is  not  equable,  and  does  not  either  increase  or  decrease  in  an 
even  manner.  On  the  contrary,  it  will  freijuently  be  found  that  a  sort  of 
gush  of  urine  takes  place,  several  drops  following  each  other  in  rapid  suc- 
cession, followed  by  a  cessation  of  flow;  and  if  the  ureter  he  watched  it 
will  be  seen  that  the  gushes  of  urine  are  synchronous  with  waves  of 
peristaltic  contraction  sweeping  down  the  ureter.  Obviously  the  urine 
collects,  to  a  certain  extent,  in  tin'  [iclvis  of  the  kidney,  and  is  driven 
thence  by  nmscular  action  from  time  to  time;  to  this  point  we  shall  return 
later  on. 

Making  every  allowance,  however,  for  these  irroj^ularities  of  flow,  we  may 
take  the  rate  of  flow  from  the  end  of  the  canuhi  ns  a  measure  of  the  rate 
of  secretion;  and  it  i.''  found  that  as  a  general  rule  increased  How  of  urine 
is  coincident  with  swelling  uf  the  kidney,  that  is,  with  a  greater  flow  of 
bl<MMl  through  it,  and  diminished  or  arrested  flow  of  urine  is  coincident 
with  shnnking  of  the  kidney,  that  iri,  with  a  diminished  flow  of  blood 
through  it. 

A  striking  instance  of  this  is  afl<>rdod  by  the  ex]>crimeut  of  dividing  in 
the  dog  the  spinal  cord  I)elow  the  lui'dolla.  The  blood -pressure  then,  as  we 
know,  falls  rapidly,  owing  to  the  removal  of  constrictor  impulses  from  the 
small  arteries  and  tlie  general  diminution  of  peripheral  resistance  which 
foUows  upon  so  many  small  arteries  becoming  dilated ;  and  though  the  renal 
arteries  probably  share  in  the  general  ivlaxation  yet,  owinj;  to  the  fall  of 
pressure  in  the  aorta  conjoined  as  this  is  by  a  corresponding  rise  of  pressure 
in  the  vena  cava,  the  flow  of  blood  through  the  kidney  is  largely  <limin- 
ishcd.  We  lind  that  after  the  oj^ration  the  a'cretion  of  urine  is  greatlv 
dimiutsbed;  indeed,  in  nio^t  rases,  the  flow  from  the  end  of  a  canula  is 
almost  arrested.  In  fact,  we  may  almost  make  the  general  as.-icrtlou  that, 
when  in  the  dog  the  l)IiKid-|)rcssure  falls  to  abr)ut  SO  mm.  Hg.  or  leas,  the 
secretion  of  urine  Is  for  the  lime  stop|K?d.  These  and  other  results  support 
the  view  stated  above  that  the  secretion  of  urine  is  in  quite  a  special  way 
de[>endent  on  the  flow  of  bhn)d  through  the  kidney ;  and  we  may  further 
conclude  that  the  secretion  which  is  so  particularly  influenced  by  the  flow 
of  blood  is  that  ."pcclal  kind  of  secretion,  allied  to  flltration,  which  takes 
place  through  the  glomeruli,  and  not  the  more  ordinary  kind  of  secretion 
by  means  of  the  epithelium  of  the  tubuli  uriniferi.     But  before  we  proceed 


THE   8KCRKTI0N    OP  rBIKE. 


S7 


itSt 


I 


C^dklillMllSott  tW  incn>(u>F((  flow  of  blixKl  iiicraue«  lh«  glomeruliir  flow  of 
'arint.  m  must  turn  (o  voiMitlvr  Iho  fiinvtiong  of  the  ppilh«Iiiim  of  the 
tiibtilt. 

SetrttioH  Ay  fA«  /tf»al  Epilhriinm, 

S  417,  The  glomerular  ineclmiiUin  ia.  nflcr  »\\,  a,  small  portion  only  of  the 
whole  kidiMV,  and  the  epithelium  over  a  large  part  of  the  course  of  the 
tubiili  urinifrri  bf»n  mo»[  dislinclly  the  rharact«rB  of  an  active  iecreting 
epilhelium.  These  ihctA  would  lead  a*  ri  priori  t<»  BuppiMe  that  ilie  tlow  of 
urine  ia  iii  part  the  raull  of  an  aaive  »eerelJo«  coruparahli^  to  that  of  ihe 
salivary  or  other  ^.dan^U  whicli  nc  have  already  ntudiud.  And  we  have  ex- 
petimeatal  and  oiIkt  evi<lenoe  that  Muoh  in  lh«  cnf». 

In  tJte  (init  pliici',  ii  ihiw  of  uriue  niny  !>a  uriilioinilv  oxt-itcil  oven  when 
the  DBlura)  tlow  liiu  hwu  iirrtnU'^l  by  diminiiltoo  of  btoott-proMtin:.  Thus 
if,  wlieo  tli«  tirint^  hag  cwuwcl  t<>  Hon'  in  riiriKiiciiiencc  of  R  werlioii  of  the 
medulla  oblotl^ta,  orrlniii  i<uht>titu<V)<,  Ruch  lu  ur<».  urate*,  sodium  ai-ctnte, 
and  iW  like,  he  injtMwl  into  the  hlotid.  a  mori;  or  hM  <»|>iou<i  wwn-tiou  is  at 
once  Mvt  up.  Thw  aecr«tioii  is,  or  nt  h-iuti  may  be,  unnccompuDiud  by  any 
riM  of  f^envnl  blood -f>remu re  suffiduni  to  iiocouiit  fur  the  incniued  secretion 
M  the  mero  mnit  of  an  incrcnsod  flow  of  blouil.  It  is  true  (lu  wv  have 
Mtn,  S  4]>>)  tliiU  the  injection  of  those  pitlMttinrM  leads  to  an  expnoBion  of 
tht  kidn«y.  an  oxpnoeion  which  is  probably  due  to  a  local  dilation  of  the 
snull  notl  arteries;  but  the  flow  of  uriuo  nhioh  is  olMarvivl  in  these  ciMOS 
■0  too  mat  to  he  accounted  for  by  an<r  increase  of  How  of  blood  which  ths 
local  dilfllwu  mar  bring  about ;  and  lienc«  we  concludi'  (hat  the  iucivast;  of 
fiecr«tion  is  of  a  diBereat  kind  from  that  which  folloir?  upon  merL-  inoreaM 
of  blood-flov.  It  seems  much  more  reasonable  lo  sui>pose  that  the  presence 
of  the  abovs  sulMtaucea  in  tlie  blood  excile^  the  renal  eiiitheliiiin  cells  to  an 
uiiwonied  adiviiy.  caadoff  them  to  pour  into  Ihe  interior  of  the  tubules  a 
copious  secreiiou.  juHt  as  the  pn«eiice  uf  piloear^nne  in  tlie  blood  will  cause 
the  salivary  cclU  to  |>our  forih  thuir  Accretion  inio  the  lumen  of  their  ducts ; 
and  that  this  aclivitv  of  the  epithelium  i-elU  in  Hccmnpniiied,  at*o  as  in  the 
case  of  the  lubmaxillnry  and  other  jflaiiilit,  hv  a  vn-Hculnr  dilation,  which, 
limugh  adjuvant  and  hon^Bdal,  i*  nut  thu  dutinci  i-atue  of  the  activity. 
This  view  i«  further  Hup)H>rtiHl  by  ibc;  follontni;  rvmarkable  experimeilt, 
wbioh  got»  far  u>  xhow  that  of  Ihe  variouo  no luioiKfLi  nhich,  having  fouix) 
ihctr  way  into  ibe  blood,  are  thrown  out  by  llir  kidn*-y.  ^ome  paeut  into  the 
urine  IhnHigh  ihc  glomcinili,  while  olhen  aiv  ili.iiinctly  Hccjvtod  hy  the  tuhuli 
uriiiilvri,  the  diichiirt^'  nf  the  latk'r  bMiiy;  nccomjutriieii  by  a  general  activily 
of  the  iH.i:r«*liu^  cclli.  ax  iihown  by  ihc  flow  of  water  taking  place  at  the 
Name  time. 

Ill  Ihe  nmi^ibia  the  kidney  ha«  a  ilouble  vascubir  sumdv;  it  receivee 
Brtvrial  hliiml  fi  im  tho  renal  nrtdry,  but  ihers  !■  «||ii)  poured  into  it  venoui 
hhn"!  from  another  source.  Tlw-  fcmoml  vv\u  divldcn  at  the  lop  of  the  thigh 
int'i  Ino  bniiH- lies,  one  of  which  runs  along  the  front  of  tlto  abdomen  to 
mee*  )i»  fellow  in  the  middle  line  and  form  the  anterior  abdominni  vein, 
white  iIm)  other  |>as»ee  to  ihe  outer  border  of  lUe  kidney  and  brsinchc*  in  the 
substance  of  that  organ,  torniiog  the  w-called  renal  portal  sy*t«m.  Non- 
tbe  glomeruli,  in  same  spciciea  At  least  of  these  animals,  are  supplied  oxclii- 
sirely  by  ihe  bmncbes  of  the  renal  artery,  the  renal  vena  fuTUe  only  serving 
to  fonu  the  capillary  plexus  around  the  tiibuli  urinifcri.  which  is  also  sup- 
plied by  the  eflereol  vessels  of  the  glomeruli.  From  thii  it  is  obvious  that 
if  the  reoat  artery  be  tieil,  Ihe  blood  is  abut  olf  entirely  from  the  glomeruli ; 
and  actual  observation  of  the  kidney  has,  in  tl»e  aniiuala  in  (jufiotiou,  sliotvn 


llml  ilio  volume  of  the  kidni^v  U  remarkably  senaitirc  to  ebeniical  rlt: 
takiiiK  place  in  the  Mooil.    "the  injmitioii  into  tUe  hlood  of  evtu  a  iina 
({uaiUity  of  nater  causea  a  traiuii«iit  sbriiiktiig  «f  t)i«  kidiieir  rulbwed  br 
tnotv  latling  ex]iaii»ii>n.    Tlie  iDJecii"!)  »!'  urea  iiml  »ume  otluT  (UurMi< 
produoG*  lilt)  name  cfTect  tn  n  ni»ro  innrked  d«jcrce,  ItailiDK  wpcciaJly  to 
Kvrelling  wbicb  ImU  for  Home  coiinidcrablv  time,  wbilc  tlic  iiij«ctioti  of  norni: 
Millie  •olutioD,  iiii<l  cMpCcially  of  micb  (liur^^litrii  ur  WHliiim  ar4!tate,  Miuea 
«xpan«ioii  fmm  the  rcry  ftnit,  thf  primiiry  «hriiiLiiiig  l)vtti(!  abwiit.     It 
moreover,  worlhv  of  nolo  ihiit  ihcsto  i-irccW  of  ditirctin  aii<l  of  clicinii 
chaiigvs  in  tlic  blood  are  obwrved  cna  nfU^r  nil  tlie  reitiil  nerven  ha 
appantotly  been  coraplvtvly  Kvunvl.     Hriicc  thf  cbungofl  iti  vulunie  ema 
by  tii«  proaeDCO  of  tne«c  eubBlimccs  ■□  the  blood  must  be  due  to  the  m 
sUtacee  acdag  either  upon  some  periphi-ml  vasomotor  tnechnuii'iii,  or,  er^MV 
more  directly,  on  the  bloodveaoole  themselves.     It  may  be  added  that  the^ 
irill  produce  considerable  effects  in  the  kidney  itself  without  a)ipreciablf 
□ludilyinj;' the  ^neral  blood- premu re 

S  416.  If,  while  the  kidner  is  in  the  oncometer,  and  the  various  expoi- 
ments  on  seclion  and  stimulatiou  »f  nerves  and  the  like  are  beinj;  carried 
oo,  a  canula  l>e  tied  in  the  ureter,  the  ^cretiou  of  urine  may  l»e  waccbe'l  it 
tlie  aaine  liuie.  It  will  then  be  ceen  tlmt  the  flow  of  urine  through  (lie  eo4 
of  the  cauula  is  not  etpiahle,  and  doeit  nut  either  iiR-reaM  or  de>:ren£e  in  u 
even  maniier.  On  the  coiilrary,  it  will  fnxuiently  be  found  that  a  «vn  of 
gush  of  urine  tiikes  place,  wreral  drujw  followiu);  vnch  other  in  rapwl  uc> 
«eaBion.  followed  by  a  c«itfuiiioii  of  tlow;  and  if  ihi;  un^tcr  \n-  waichol  it 
will  be  ?een  that  tlie  )[Uiih<=t  uf  urine  ar«  michronouii  with  wavcu  of 
perislHltic  cciutnii-tioii  n«XTpi»]^  down  the  urtttitr.  Ohviouxly  the  urine 
collecui,  to  II  cvrtniu  extent,  in  the  pelviii  of  the  kidnvy,  and  ■•  driven 
thence  by  niuncular  ncliou  from  time  to  time ;  to  this  point  we  shall  relnrn 
later  OD. 

Haking  every  [i1]oi\imce,  however,  fur  these  irrcgiilaritice  of  flow,  vn  naj 
take  the  rnle  of  How  from  the  end  of  the  canuin  as  a  measure  of  the  rate 
of  secretion  ;  and  it  in  found  thot  as  a  general  rule  increased  flow  of  urine 
is  coincident  with  swelliu),'  of  the  kidney,  that  is,  with  a  (■^"'c  H'^*'  '*f 
bloitd  through  it.  and  diminished  or  arrested  fliiw  of  urine  U  coincident 
with  shrinking  «f  the  kidney,  that  is,  with  a  diminished  Dow  of  blood 
throu)(;h  it. 

A  Mrikiug  inaiaueo  of  this  is  alTordeil  by  the  exi>eritueut  of  dividiujr  in 
the  dog  the  xpinal  cord  1>elow  the  mohilln.  The  hlocl-preuiire  thi^ii,  a*  wo 
It  now,  Ml*  rnpidlv,  owing  to  the  I'cmoval  of  constrictor  impuUesi  from  the 
small  artcriot  luiii  the  gcnernl  iliminution  of  peripheral  rMiitance  which 
Ibllow*  upon  to  many  >iunll  arterice  becoming  dilalL-il ;  and  though  the  n-iial 
arteries  probably  nharc  in  the  general  relaxation  yet,  owing  to  ihe  fall  of 
pressure  in  the  aortn  conioinnl  in>  this  n  by  a  corrtaimnding  rise  of  prcmirr 
in  the  vena  cava,  Ihe  tlow  of  blood  through  the  kidney  is  largely  dimtP- 
isbed.  We  lind  thiil  sl^cr  the  opcnili'>n  the  wcrction  of  urine  is  grmtlr 
diminiehed;  indeed,  in  most  cases,  the  flow  from  the  end  of  a  caaula  it 
almijet  arretted.  lu  fact,  we  may  almwt  make  the  general  aasertiou  that, 
irben  in  the  dog  the  blood- pressure  fulls  to  about  SO  mm.  Hg.  or  leas,  tbe 
secretion  of  urine  is  for  the  time  stopped.  These  and  oilier  r«<!ults  Bun|Mri 
tlie  view  Mated  above  that  Ihe  secretion  of  urine  is  in  quite  a  special  way 
dependent  on  the  How  of  blood  through  the  kiduey ;  and  we  may  further 
ooncludc  that  the  secretion  which  la  so  pnrlicularly  inllueuoed  by  the  flow 
of  blood  ix  thai  .-jiecial  kind  of  secretion,  allied  to  tiltralion,  which  takes 

Clace  through  the  glomeruli,  and  not  the  more  ordiuiiry  kiml  of  ^ecrolion 
y  nwnni  of  the  cj>ilhelium  of  the  ttibuli  uriuilert.     But  before  we  prucvwd 


TDK  9KCBET10N   Of  I'BIKK. 


587 


I 


I 


to  (lisciMj  bow  the  increiued  flow  nf  Mmx]  iiicreaaea  tbe  glomerular  flow  of 
uriiip,  w«  tuuBt  turn  to  ooosiiler  ttie  flinctauit*  of  tli«  i']>Illi«liiitii  of  tlic 
tubiiti. 

S<*irfiioH  A.v  'Ac  /friin/  EpUhfiitim, 

§  417.  Tko  gUHneniliir  iDechiiiiiiim  i«,  Hftor  nil,  ii  KinttU  pDrtioii  oitly  of  tb« 
w)iol«  kitiiK'r.  mill  thu  viittln'tiinti  ovtrr  it  largo  piirt  o\  thr  i^itirw  of  the 
tubuii  vrini/i'vi  Infir*  numt  dlMiiiolly  llic  4^hiiniclcr«  of  iin  ucliro  RccrtltiDg 
opitholiimi.  TIktm  JacU  wtiulil  l«ui  ii»  'V  priori  to  nipjicwe  tbiit  ihe  flow  of 
uriiif  in  ill  pnrt  ibo  nsiult  of  tin  iK-tivv  scrrction  ctfnipnriibte  to  that  »f  th« 
K«li\-iir_v  "r  other  inlands  nbidi  ve  htivc  already  studied.  And  w<?  bave  «x* 
p<^rinH-uuil  iind  other  evideDCe  thai  ouch  is  tbe  nue. 

in  th«  first  place,  a  flow  of  tirilie  mar  be  artiliciallr  excited  even  wlicn 
tltc  Diittiral  Hon  hiu  been  arrated  by  dimiiiution  of  blood-praseure.  Thus 
if.  when  the  urine  has  ee«»ed  lo  flow  id  consequeuoe  of  a  section  of  iImj 
niodtilla  oblor%«ta,  cerlaiti  sobitanoee,  euob  as  urea,  urates,  sodium  avetatv. 
Uld  llie  like,  be  iiijevted  into  the  hluod,  a  more  or  Itsa  copious  aeoretion  is  at 
onoe  set  up.  This  secrelion  is,  or  at  least  niair  be.  iinaonorapnuied  hj  any 
rise  of  fteiieral  blmtd-preK^tire  sulficiem  to  aoci>utit  tiir  tlit!  increased  aeoretion 
OS  the  mere  reeult  'if  an  im-reased  tlow  of  blood.  It  is  Inie  (as  we  havo 
Men.  ^  416)  that  the  iiij^L-tinti  of  ih«4>^  rulistanees  leads  to  au  exj)ati«oD  of 
Ihe  kidney,  ati  i3X|>uiL'>i(>ii  which  Is  pmhahly  il(i<-  ti)  u  locnl  dilation  of  Ute 
small  renal  arteriiii;  hut  thi-  ttow  of  urim-  which  i«  ohstervexl  i»  these  cases 
is  too  ureat  In  be  iirroiint'il  for  by  »nv  tmrrciM-  of  How  of  lilond  n'hidi  the 
local  dilation  may  briri^'  ahiiui ;  luid  hciKV  w«  ci>ii<^luik  llinC  the  itinn-iuw  of 
secretion  it  of  a  diffcrnit  kind  tV»iii  thiit  whii-h  follown  u|x»i  mere  iooreaae 
of  blaod-fli>w.  It  tu'i'mn  much  nmn-  n-iin>innbUt  to  suppoAC  that  tbe  preaonoe 
of  th<-  al>^iv«  KuWiiiici^  in  the  litnod  cxcitt^'*  th«'  roiiiil  ttpithcliuui  ceili'  to  iin 
niinciiitnd  iiciivily.  ciiuoin^  ihem  to  pour  into  tb'!  intcnor  of  the  tubulwt  u 
cofHoui  SMfttiioii,  jiint  m»  tne  preMnoc  of  pilociirpine  in  the  blood  will  ntuw 
llie  salirary  cclU  to  [mur  forth  their  iwrotion  into  the  lum«n  of  thoir  dutft»; 
and  thill  ihii  iictivilr  of  the  epithelium  <m:IIs  is  ncoonipanied,  al«'>  ik  in  the 
aiM.'  of  tbi.^  nnbmaxilhiry  atid  other  glands,  by  n  vascular  dilution,  which, 
thotigh  ailjurnnt  and  IwoHicia],  la  not  Ihe  distinct  cause  of  the  activity, 
Thix  view  ii>  further  viipporled  by  the  fitlowiug  remarkable  experiment, 
whirh  goes  tar  to  show  that  of  the  various  substances  which,  having  found 
ibfir  way  into  tbe  blood,  are  thrown  out  by  the  kidney,  some  pass  into  the 
urine  through  the  glonienili,  while  others  are  di^liootly  secreted  by  tbe  tubuli 
urinileri,  tbe  dischar;^  of  tbe  latter  being  accompanied  hy  a  general  activity 
of  the  secreting  cells,  a«  shown  by  the  flow  uf  water  taking  place  at  the 
aame  time. 

In  the  amphibia  tlie  kidney  line  a  double  vascular  sapulv;  it  leoeivee 
arterial  blood  fr^m  tbe  renal  artery,  but  there  is  also  ])aurei]  \nt6  it  venous 
blood  from  another  source.  The  femoral  vein  divide  at  the  top  of  Ihe  tlii|tli 
into  two  branches,  one  of  which  runs  along  the  front  of  the  abdomen  to 
nte^t  ita  fellow  in  tlie  middle  line  and  form  thw  anterior  abdominal  vein, 
while  the  other  paaiwi  In  tite  outer  border  of  tbe  kidney  and  hrnni'litM  in  tbe 
nulmtanre  «f  that  organ,  forming  the  uncalled  renal  portal  nvHiem.  Now 
tl>«  glomeruli,  in  Ni>ine  xpeciisi  at  least  of  tlMM>  animal*,  are  itupplicd  cxelu- 
Nivcly  by  tlie  branches  of  the  tunul  artery,  the  renal  vena  porti«  only  serving 
tJi  form  the  caniltnry  plexu*  around  the  tubuli  uriiiif^ri,  which  is  also  sup- 
plied by  the  efferent  vtwu-ls  of  tbe  glomeruli.  From  this  it  is  obvious  that 
if  the  renal  an<!ry  \w  tied,  the  blood  is  *hnt  off  witircly  from  the  glomeruli; 
and  uetuAl  oWrvalion  of  tlie  kidney  lius,  in  tbe  animals  in  <tuestion,  shown 


TllK    CLIMINAl 


thai  umlcr  lh<wi  drcunMADCM  Umhw  U  au  it>|Iiis  fruni  tin'  cnpiMnrjr  ttetwn 
cdrnniiiilitiu:  iW  tiilxilo  bnck  to  th«  glmni-nili;  Itio^  kUv  kidavy  by  ti 
•iinpla  owmtii'ii  ix  tniii>f<>rnKil  ioto  tut  <iolii>urir  M-cr^iing  gland  devniil  •'( 
imy  sfMcial  tillrriit);  mrcliiiiiUiii.  Such  n  kiiliiry  niny  )«  iiattl  la  aan^iuia 
tthiit  MibrttUK'M  nru  oxcn'ted  hy  the  gtonM-riiM.  nml  nhut  In-  the  tubules  io 
some  otiicr  ^mn  »f  thHr  wxirw.  It  is  riniiii)  ilmt  iireii  iDJccted  inu  tk 
hlond  giv«  riM  to  n  fountioii  of  uHiitt  when  the  renal  arleries  aro  tte<l :  tbit 
•ubdniice,  therefore,  is  secreted  by  Uw  epilheliuni  uf  tho  lul>ule8,  unit  in 
being  so  secreted  gives  riM  nl  the  Mine  tlDie  to  a  flow  of  waler  thrmi^fa  th' 
cells  into  tlie  interior  of  the  tubules.  8u|nr  and  peploiiea,  on  the  oltiPt 
baud,  which  injected  inta  the  McxmI  reatltlj  {xtw  tliruugli  tliu  unUMirW 
kidney  and  apiiear  in  the  urine,  do  a<A  pass  tlirough  b  kidney  the  mial 
arteries  of  which  have  been  tied,  m-ea  when  a  diuretic  aucji  aa  unv  >■  tfivta 
nt  the  same  time  iu  order  to  secure  a  lluvr  of  urine.  Thcae  Mibalaaina,  U)tfn> 
tbrv.  are  uxtreted  by  the  glomemli. 

The  valiiliiy  <i(  tliia  ex  peri  men  t.  whii'h   may  be  lUTcepted   u»  in  .  a 

lunrkcd  difl'pr(!Oce  Iwiweuu  gl'imi-riiliir  Ktrcretiun  uu  Uie  one  hand  i .-- 

liul  iir  tulmlnr^rtTi-tioii  »u  I  In;  iiih(.-r,di.-|ii'ud.i  on  the  absence  of  any  mllalrnl 
circiiltilioii  wlnn-hy  tin-  glunn'riili  may  In-  nuiiplled  with  blotxl  iillier  ligature 
of  the  renai  artery.  In  these  animals  anaMonKiMw  occur  between  the  rooal 
arteries  aiw)  thi- nrterin of  tlw generative orgaun;  and  uulctt  llwiwial  artery 
be  »o  tied  as  to  avoid  thme  t.'olliuerul  coiumunicatioDs  tlie  rteulta  of  tJie  ex- 
periment are  diflereiit, 

Additional  evidence  i»  fiivor  of  the  Kcrvtor%'  activity  of  tba  ■■]>ilholiuR) 
cells  is  aflorded  by  the  folluvring  obofrvatiuii.  ^nto  the  voJaa  of  nniinals  in 
wlueh  tbe  urinary  flow  bad  been  urraeled  by  section  «f  the  siunul  cord  l>elo» 
tbc  medulla  a  i|Uantity  of  (h<<  blue  oloriug  material  known  ns  sodiuta 
i>iil{>)iimli|;otale'  w  injected.  Tbii'  snbrtmice  is  rapidly  excreted  on  ibeooc 
hand  by  tlii;  liver  in  the  bile,  and  on  the  other  hand  by  the  LidBey.  By 
Tarying  tlw  tjuautiiy  injected,  killing  the  auiraals  at  appnipnate  LiiaeB  aA*r 
the  inji-trtion  of  the  material,  and  examining  tbe  kidiMya  mioroecopicolly  uil 
othcmii^,  it  may  be  ascertained  that  the  pigment  so  injected  pasMS  from  tke 
blood  into  tbe  rcnni  vpiihelium.  and  frum  llieuoe  into  tbe  ebanneh  uf  tbe 
tuhulw.  There  beiti|^'  im  niniiiu  uf  lluid  through  the  tubules,  owing  to  the 
arrest  of  urinary  l|i>n  by  nti'uuit  uf  tht-  pn^liminary  oininilton,  l)ii<  pignK'Bl 
travels  vcrj' lilllc  way  dun  n  tbu  inttiHor  uf  tbi:  tnbuica,  lunl  rental iw  veiy 
much  wWro  il  was  ca»t  nui  by  the  epitbelium  cellii.  There  urn  no  mots 
whatever  of  ihd  pigrmml  having  iwaed  by  the  ([loaieruli:  and  the  cells 
which  appear  most  diatindly  tti  take  up  and  eject  it,  are  thim.-  lining  sunk 
portions  of  the  tubules  (vii.,  the  linil  anil  •ccoud  otmvoliitrd  lubuliii,  ligxag 
tubules  and  aaoendiug  limlm  of  tht^  l()o|«  uf  H«nlci  im  fmm  their  niictw 
Mopic  features  have  been  «upp<jv<il  tu  he  thcnctindy  HTrrling  |><>rt><tRBOf 
the  entire  tubules.  The  folhiwing  oWrvnliou  which  hux  l)een  miulo  i»  of  m 
peculiarly  interesting  character.  Alter  injecting  a  certain  <|UHnttty  of  iiig- 
inent.  imd  allowing  Aucb  n  time  tu  cln[iBe  as  mi^ht  be  judged  front  previoill 
es|iL'riiutiilii  notihiHultitH'  for  the  passage  of  the  material  through  the  epilbv 
lium  to  Iw  pnMty  well  iMmpleted,  a  second  quantity  was  injected,  it  was 
fbund  that  the  cx<!ix'tii>n  ol  this  seuHod  c|uaDtity  wad  iui»(  incomplete  anil 
iraperfci'i.  It  xeenied  as  if  the  cells  were  exhausted  by  their  previous  ellitTU, 
just  as  a  miiM'lc  which  has  l>eei>  severely  lelsuiixed  will  not  rsepond  to  a 
renewed  Mimulation, 

The  above  obwrvation  may  be  objected  to  on  the  grouuil  that  this  oolorloc 
matter  doesnot  occur  ns  a  constituent  of  tbe  blood  aiher  in  In-alth  or  diMOM, 

I  lomrUuiM  dillM  IndlisiMunnlnf.  thnusli  tin*  mm*  b  mgn  PKqsrl)  aiiplMit  U  a  crwto;  tmim 


UlllNE. 


rinlly  ilml  tlie  HWnce  of  nuy  oonoomiUui  (liB(-)iaii;e  of  fliiM  fVoni 

Hi  l^x^iI<1l  ■u*|>i(.'H>u  thai  the  procMa  ob»er^'«ll  was  not  rmllv  mie  of 

Hitm  ;  fur  the  iojeclion  of  such  nuIiMnnws  u  urea  ur  uratei  iiiio  th*:  Woo.) 

don  raiiH  a  i-ri|>i<iua  Buw  uf  tluii),  am)  imltnil  lhtj«  preveut»  iht*  niicroficipk 

ttadciog  imt  nf  tbi^lr  pmange,  which  in  th«  cue  of  unua  miKlu  othi-rwiw  Iw 

AttM  much  in  the  Mtae  vrmy  a»  with  ilx;  wodiuin  sulphiDdiguuii-.     Mi)T«ov«r 

othvr  nfatenren  hmvt  nuuiirBtiicI  ihni  rliv  MHliuni  oulphindliKoruic  doeti  like 

nrrlfnary  cnrmin*  Mfs  thmtifch  lh4>  gh)mcruli.     Kiit  ihvir  niiull*  iimy  proh- 

vhtv  \-r  rxpIaiiH'H  by  lh<-  )iloiii<'nili  having  licrn  dnnitijiicil  hy  n  Ino  rn[iid  or 

loo   abuiiilaiit   ii)J4-(Ht<Hi:  iind  in  thf  c«iw  i^f  th*-  itnijihihiaii  kidti«y,  wlifn 

Hum  *td|ihiiiiligo(at<'  «•  injcctrfi  after  ligntiirc  of  reiinl  iirlcriw,  no  iiriiio  n 

>im1  io  the  bladder,  (ml  iho  pigtiicnl  win  he  trtiocd  thmiigh  the  <'piilii>tiuni 

t^  werelinK  portions  of  the  tutMiUw.     AVilhouC  inoitting  to<>  much  »n  the 

I  of  the  aodiuiii  Nilphindigotate  experiments,  ihcy  mny  bo  takvn  tut  fairly 

■pporting  Ihe  view  which  we  are  cunFiilenni;.     We  mny  ndd  that  ii>  binU, 

Lbo  uriDe  of  which  coDliiiiis  lilllc  wnier.  iirnlcs  mny  be  delecte<l  in  llw'  epilhe- 

lium  of  the  lubiilea  but  not  in  tho  cnpeiilcs. 

Tbou);!)  much  remaim  to  be  cleared  up,  we  may,  for  (he  present,  conclude 

that  the  secretion  of  urine  doc*  consist  of  two  neparale  and  distinct  acts; 

MTtvUon   by  the  i^looteruli.  which  we  may  for  brevity 's  sake  »peak  of  u 

gfemerular  («cn?<iuii.  and  seci-etion  by  the  epilht<liiim  of  the  ttibiiti,  which 

■t  msy  sfieak  of  siniilariya«  tubular  secretion.     But  these  forms  of  sccrelion. 

specially  the  former  but  Io  a  certain  eiteiil  the  latter  al»».  differ  from  the 

•Kreliion  of  »uch  a  iiland  na  the  aolivary,  oiid  both  deserve  moie  special  cou- 

•idemtion. 

■     S  418.   The  nature  i>f  glomfnlar  trerelion.    We  linvo  seen  that  lh«  expnn- 

■Won  <tf  the  kidney  which  hait  for  its  accompaniment  no  increaeed  flow  of 

tarinc  bi  one  bmn^il  about  hy  the  renal  nrUTV  and  il*  varinUH  hranclMB 

txcinniog  dilated,  under  mch  circnmetoucn  thni  the  dilfcrrncr  between  the 

blnaMl- litem  re  in  Ihe  anila  at  the  mouth  of  the  renal  artery  and  the  Mood* 

KiTMUiv  at  the  vena  cava  al  the  mouth  of  the  renal  rein  i»  at  the  Mime  time 

*ncreiw«l,  or  at  all  mcni!"  is  not  diminished.     We  say  ihc  renal  arleri-  mid 

it^  varioti*  bnancho'  aince  nnr  present  knowledge  will  not  enable  ii>  l>i  make 

»  more  eiad  siatemtmi.     It  i*  of  oourse  pOMible  that  nervous  impulse*  [mu*- 

int;  al'ing  pnrtJcaliir  nervo  fibres  should  confine  iheir  ellorls  to  relaxing  the 

mats  of  tne  vna  aHircniia  of  the  ^doiiienili  and  not  juuib  to  ihc  other  hmnehrf 

tif  the  renal  artery,  in  which  viw  the  circulation  of  the  iflomemli  would  W 

exclusively  lor  ne«irly  so)  affected  :  but  of  this  at  pres«iil  we  kitow  nolbing, 

aw)  the  ^neral  nf;;iimeHt  remains  good  if  we  sitealt  simply  of  the  brancbca 

of  ibe  renal  artery  as  n  whole. 

In  dealiiiK  with  the  vaacular  sy^ieiu  we  saw  that  relaxation  of  a  small 

I  artery,  lakin^  place  without  any  marked  changv  in  tite  t;ei>entl  blood-pres- 
Hirc  and  in  iieir^h boring  arteries,  leads  t<>  a  fuller  mid  more  rapid  Mream  uf 
htdod  ihruugh  the  capillari«!i  supplied  by  Ihe  iiriery,  and  that  at  the  same 
tine  the  prCMure  in  the  capiUari>-«  thcniM-lvi!*  u>  increoml;  owing  li>  the 
ilrtmue  of  peripheral  roiitunee  throiigb  ihe  widening  of  the  artery,  the 
fmi  fall  of  urmtnre  (tte  $  111))  »t  charncteri*tic  of  the  [leripheral  region  U 

(■hiflrd  from  IM  arterial  nideof  thecupillarHii,  toward  the  vcnoui'  si<le  oiu)  to 
Ihr  cBpillnrice  ihemoelvi-n. 

Hence,  M  we  have  alrendy  tuiid,  when  the  renal  arlery  dilate*  two  thinga 
ha|ip<'ii  in  the  loop*  of  the  glomeruli :  a  fuller,  mon.'  rapid  slmiu  of  liloud 
|aa»n  ihrriugh  tlwm.  and  that  bliuxl  as  it  Howi  ihnmgh  Ihem  ic  exentng  a 
l^reaier  pn-wtiru  than  bi-((.>r«  on  iheir  wallx.  How  duM  each  of  the  oventa 
ataml  Ifwani  the  secretion  of  nrinc? 

Wv  liuvc  tMt  at  pr«4«nt  Ihe  meoiia  of  iitducing  a  Ailter  and  more  ra[ 


640  THE    El.IMIXATIOS    OF    WASTE    PBODL'CTS. 

flow  without  increasiii);  the  pre^^ure;  but  we  ninv  easilr  obtain  iacreaae  uf 
prei«ure  nithnut  the  fuller  ami  more  rapid  How.  If  we  hinder  or  obstruct 
the  outflow  through  the  reoal  vein  we  at  once  itierea^e  the  nreaaure  Id  the 
gtomenilar  l<H>|nj  ns  itt  the  other  capillaries  of  the  kidney.  Xow,  when  tht 
hlood-pr&<8Lire  in  the  glomeruli  is  thus  raised  bv  partial  obstruction  to  the 
venous  outflow,  the  flow  of  urine  so  far  from  l)etng  increased  is  dimiDished. 
Obviously,  then,  the  passage  of  water  and  material  through  the  walls  of  the 
glomerular  lon)t)<,  to  go  to  form  the  urine,  if  not  the  result  of  mere  pressure, 
and  cnnnot  therefore  be  spoken  of  properly  us  a  jiroeesa  of  filtratioD. 
(t'f.  S  303.)  And  we  may  here  draw  a  cDnipariaou  between  the  passage  of 
water  and  material  through  the  wall  of  a  capillary  in  an  ordinary  situation 
to  form  lymph  and  the  pat'i'age  through  the  wall  of  the  glomerular  loop  to 
form  urine  or  part  of  urine.  The  former,  as  we  have  seen  (§  :}03),  appean 
to  be  directlv  dependent  on  pressure,  though  influenced  as  we  have  also  sees 
in  a  very  material  way  by  the  condition  of  the  vascular  wall ;  and  hindrance 
to  venous  outflow,  gii  incfbcient  in  promoting  a  flow  of  urine,  is  as  we  have 
seen  es|>ecially  favorable  to  the  transudation  of  lymph.  In  the  former  cue 
the  sulMtances  which  paas  through  the  capillary  wall  mav  be  described  a*  the 
constituents  of  the  blood  t.'enerally,  proteids  as  well  aa  saW  and  other  soluble 
and  diH'osiblc  lualters.  Through  the  wall  of  the  glomerular  loop  there  pa«, 
so  long  as  that  wall  is  sound  and  intact,  neither  albumin  nor  globulin  dot 
filirin  tactor,  but  only  water  acrampanicd  by  some,  and  apjmrently  a  selection 
of  .some,  of  the  soluble  ilifiiisible  constituents  of  llie  blood ;  for,  as  we  have 
said,  the  presence  of  proteiiU  in  normal  urine  u  contested,  and,  at  moel,  there 
is  prciM^nl  a  very  small  quancilv  only  (which  moreover  may  come  from  the 
tubular  epithelium).  This  difterence  in  the  material  which  passes  through 
may  be  referreil  to  the  diHerences  in  the  nature  of  the  partition.  The  trans- 
udation of  lymph  takes  place  through  the  capillary  wall ;  between  the  blood 
on  one  side  and  the  lymph  in  the  lymph-sjiace  on  the  other  is  only  the  thin 
Aim  of  conjoined  epithelioid  plates.  Kul  the  corres;Hinding  wall  of  the 
glomerular  loop  is  covered  over  and  wrapped  around  so  lo  speak  by  an 
adherent  layer  of  ceils,  which  though  reduced  and  thin  are  etill  epithelial 
ccIIh  :  the  materials  which  go  lo  form  urine  have  to  pass  through  these  cells 
as  well  OB  through  the  film  of  epithelioid  plates.  It  seems  to  be  this  layer  of 
cells  which  determines  what  shall  pass  and  what  shall  not. 

Obviously  the  passage  through  this  epithelium  is  of  a  peculiar  nature. 
The  neces^nrv  conilitiim  for  the  due  accomplishment  nf  the  passage  is  as  we 
hnve  seen  a  full  und  rapid  stream  of  i  arti'rial)  bliKid  :  the  high  pressure 
which  accompanies  lliHt  full  and  rapid  strciini,  though  probably  under  normal 
eiri-u mstanci-M  an  adjuvant,  is  by  itspU'  hclpie*!.  Thu^  when  the  pressure  is 
raised  by  venous  olh»tniction,  in  which  cai*  the  high  pressure  is  accompanied 
by  a  hI'iw  stream  or  by  actual  arrest  of  the  llow,  even  tlie  passage  of  mere 
water  is  retarded.  Seeing  that  many  of  the  Constituents  of  urine  are  dif- 
fusible suhstanci^  ccrtainlv  preexisting  in  the  blood,  inorganic  salines  for 
instance,  and  »t*ing  that,  if  we  may  trust  ibe  exjKiriments  on  the  amphibian 
kidney  .*jM)kcn  of  aliovo,  diH'iisible  ahnorinal  iMnstilucnta  of  blood,  such  as 
|)epli)ne  ajid  .*ugar,  pa.-s  into  the  urine  not  by  the  tnhular  ejiithelium  but  by 
the  glomeruli,  wf  might  expect  that  didanion.  in  contrast  to  tiltration  (.see 
•:  :ii;>),  phiyeil  an  im|>ortunl  part  in  the  |>a3s:igi' ;  and  a  full  rapid  stream 
would  und<iid)tedlv  tiivnr  diOii^iion.  Birt  diffusion  l>y  itscif  will  not  explain 
mntters.  Efnr-nlbuniin  dillcrs  very  slightly  as  regard-"  dilfusibility  from 
KTuni-nlbuniin,  au<l  yet  while  at  the  most  a  minute  ijuanlity  only  of  the 
laitci'  posscri  into  the  urine  in  normal  circumstances,  the  former  when  injected 
into  the  blood  at  once  maken  its  wuv  into  the  urine,  presumably  bv  the 
gbmieruli.     On  the  <ahcr  hand  urea  is  an  etuinently  diffusible  body,  and  yet 


i)io  (■x{>cHtueiiui  on  the  iiiuiiliibinu  kidney,  the  Dinin  maMSt 
■II  rvTtil*  lit  thr  iinii  of  titv  uriue  |iiiM«s  by  llie  ejiitbi-liiiiu  t>f  (be  UiIhiIm. 

TlivitBporlaul  |iiirl  [ilnytif  by  tlii-epitbeliuni  urhuKii  ohrii  th^e[iitlif]iiim 

!•  (lena^l.     Jl'  the  n-mil    artitry  bi-  temporarily   li>:utiirt.il  nr  othfTwiw 

obMnicit*),  to  ihnl  tlkC  glomenjli  nn  nhiit  ntl'  IV(>in  tbcir  btiHulstipjily  for 

•eOM  liltir  tini«,  Xhti  iwrciioa  ol'  titinc  !»  !>t(ii>]ir(l ;  on  nt^ablUhmrut  of'  th« 

^fcalslion  tKr  frort-tioH  nftirine  vlonly  rctnrnK.  •in)  Ibc  urine  i*  thin  (oanA 

«0  bt  albuminoti*.  rrniniping  m  fnr  wmc  liltic  time.     Tho  :>criim-tilbiin:iin 

«Dd  globulin  nliicli  c-ouM  not  mm  through  the  intact  rjiitbcliitin.  ciid  pnw 

Vbrougfa  wlH'ti  ih«  t-|iilhHhiin  is  (Uitia^cn  b}*  intcrfervncr'  with  its  nutrition. 

The  iip|)fanow  of  «II>umiti  in  lh«  uiia«  (Klbuminuriii)  i*  a  not  infrm|iMrnt 

■jnptom  of  kifioer  diMiuc,  and  it«  prcecDce  in  other  than  minute  qusniitits 

itHiimee    iiuperf<y;lton«    in    the   eloin«ruliir  i^pilhclium.     Uut  even    under 

UBbmllhr  condiiiona  (hui  epilhelium  Ftill  L'ovenis  lo  a  cerlun  extent  llw 

Cmape  of  material ;  fur  thcproieideof  ihi>blo<Kl-pln£nia  do  not  psse  through 
<dil\  ur  in  a  proportion  whicb  correepoude  cither  to  the  retutivc  projHiriion 
hi  «hieh  iliey  esiti  in  the  plasma  or  to  the  relative  eaw  (or  difflfuliy)  vfiih 
which  ihey  pais  ihrfiuj{h  membrsncs.  Though  the  "albumin"  of  ulhu* 
iBinou»  urine  Iroqucnily  comiMaof  both  serum -album  in  nnd  (;lol>uliu,  tkrae 
■k  nut  Dvce«Mrily  (kvqt  in  the  aaine  proportion  as  in  bluoit ;  they  vary  la 
■rina  much  more  than  they  do  in  bluod;  and  indeeil  the  one  or  the  other 
mmj  be  aWnt ;  moreover  librin  factors  are  very  rarely  found. 

nwinoKlobinuria,  or  ihi-  presence  of  hmDi^lohin  in  urine,  loav  be  broUfrht 
about  liy  injii-tiufc  into  the  bloTKlvt-^i'dii  laky  bltHfl,  or  some  •nlMtani'O  Hic-h 
•*  pyrogallir  acid,  nhicb  will  "brrnk  up"thr  corpui>e]ea  oftbo  blood.  Now, 
in  aucb  cam  there  i*  evidenec  that  the  hnrmoglobin  panes  through  the 
^lom^ruli;  minute  difo-likv  ratatt*  of  h»moglobin,  lhL>  fo-nlled  "nieninci," 
mre,  by  appropriate  mcthixls  of  pre|HtralioD,  found  in  rilu  in  the  cajwultv. 
6urb  ■  p«wag;e  t*  very  far  removed  from  being  n  proccn  of  diHiisioD. 

We  niny  conclude.  ibcD.  ihni  the  |)(i<saee  of  malerial  ihrouKh  the  );loni- 
*ruli,  like  ihe  tranmdation  of  lymph,  ana  even  lo  a  more  marked  extent, 
is  •  complex  affair  in  nhicb  the  ordinary  physical  proceasea  of  dllfliaion  and 
filtr«iiou  may  plav  their  part,  but  are  not  masters  of  tlie  situation. 

S419.  7"Af  wori  0}  Ihe  rjiithflitmt  n/  the  tubule*.  As  we  have  aaUi,  the 
alrunurvl  features  of  the  epithelium  cells  of  the  tubules  seem  l<>  jUKlify  the 
eoDclu»iun  that  they  exerote  a  secretory  actJvitv  comparable  witli  that  of  iv 
Mlivnry  ••r  a  gimtrii'  gland.  But  their  itork  !m  in  maov  nay*  [wciiltar.  lu 
ibe  c-n>L-  of  I  hi-  -iili^an'.gHMri?,  and  pancrcttlic  glaudu  llirrc  can  be  no  duiibl 
that  I  hi-  vfiecific  Cunflilueni*  of  tbe  tcvoral  Kcrelions,  mucin,  jiegnin,  lirprin, 
and  ihe  like,  arc  inaDufaotun-d  in  the  alveolar  cells  out  of  aiilt-C4-deuti<  of 
fome  nature  or  other.  The  evident-,  *n  we  have  teen,  it  all  agninct  the 
view  that  tbne  glan<l)'  mi.-iply  wilhdntw,  Mcrcle  in  the  old  sense  of  the  word. 
from  tbe  blood  lbe«i-  lulwtnnccs  preexisting  in  the  blood.  When  the  Bulivary 
^nds  are  extirpated,  or  the  pancreas  or  the  stomach  removed,  (here  is  no 
iccumutatioD  in  tho  blood  of  the  fpecilie  constituents  uf  the  correeponding 
secretions,  tro  also  nhen  the  liver  is  extirpated  there  is  no  accamuialton  in 
(be  blood  of  either  bile  acids  or  bile  pigment.  With  regard  to  the  kidney 
■D<1  Ibe  iDOet  important  eonrtiluent  of  urine,  namely,  urea,  tbe  eaee  is  differ- 
enl.  If  tbe  kidnersin  a  maiumal  be  extirpale<l,  or  if  the  kidneys  by  disease 
or  by  liitalure  of  tte  ureters  be  so  damaged  as  lo  be  unable  to  carry  on  their 
vork,  an  acrumulalinn  takes  place  in  blood,  nut  an  wat  once  thought,  of  some 
Mnlrei-iioiit  of  un'A,  »ueb  at  creatin,  but  of  urea  itiwlf.  In  the  caM.-  of  birds 
■  nd  r«[>tilr>  which  exircte  not  ureu,  but  chiefly  uric  and,  the  iK-eumiihilion 
]•  line  of  uric  acid.  Obviously  in  >ccrctlng  uron  the  work  of  the  epithelium 
of  ihr  tubules  is  largely,  if  not  exclutively,  conliutd  to  >imply  [Peking  the 


542  THK    E1.1MISATI0N-    OP    WASTB    PE0UCCT8. 

ur«n  out  of  l)ie  blocx]  aui)  [uiBbini^  it,  »i  to  »m«k.  iuio  Uw  Iiimlnn  of  the 
luhulfv.  Wt<  lut^hl.  |>erluips.  Bay  exclutivdr,  lur  there  U  nu  vviilcncv  itiai 
«tiy  rirfn  lU  ull  \»  actually  iiiHnurA(Ttiin.-d  in  ihr  kiilooy. 

Uut  e\'rn  thiit  iiii-re  tiickiti);  uji  ilii.-  una  u  afWr  all  not  n  nintplo  pixiccM; 
tbe  epithclitil  cell  »f  the  tubule  U  iiui  n  tiieri:  jiiunivi-  «i<-ri-  of  jioculinr  Mruc- 
ture,  oepcciall/  tMUjttcid  to  siraiu  dIT  the  urea  from  tlic  l)l<x>d.  As  nr  have 
aln-ady  nen,  when  iireu  or  uric  aui<l  Ih  injecloil  into  the  blood  (tie  nmilt  u 
not  a  mere  iocreaac  in  the  proporliuus  uf  iirvit  (Vtr  uric  acid)  present  iu  th« 
tiriiw  which  is  being  nL-orctn).  The  injccliou  Iviuti  tu  ua  increaseil  jlof  0/ 
MriW,  tl>e  whole  oelivily  uf  thv  cell  ii*  fllirrrd  up.  Kiid  other  ooaslitueiiU,  pot 
at  th«  momeul  like  tliv  urcn  cxisEiiig  in  exocM  in  lh«  bluod,  arc  dtBckarfEtd 
iuto  the  luinina  of  the  CtibuUv  toother  with  the  urva. 

How  the  titea,  which  u  in  thu  peculiar  manner  token  out  of  the  blood, 
conwi  to  make  iu  appearance  in  the  blood  is  a  problem  !□  which  tbe  kidney 
ia  DOl  conoerned  aod  with  whicli  we  shall  deal  in  treatiof;  of  tbe  tueUib>ilic 
events  of  tl)t-  body  generally' 

!i420.  In  tlt«  caoeofeome  other coostjtuentsof  tbe  urineweluiTeevidwce 
that  tbo  colU  do  something  mure  tlian  iiinijtiy  pi«k  the  couitilueut  uut  of  the 
blood.  Iiii>i>uric  acid,  as  we  have  ^««u.  occurs  Id  small  ijuEuititv  in  the  unnc 
of  mao,  and  in  Inr^-er  amount  in  tbe  unue  ofbetbivoro.  Now,  liippuri<:  add 
may  be  foruKx)  by  the  combiDatiou,  with  dvbvilraiion,  of  betuoiv  Kcid  and 
alyciu  (0,11,0, ■i-C,H.N0,—  H,O  =  t;H,N0,>:  and  benwic  acid  inlro- 
duoed  into  the  alimentary  caual  ur  iuieciAiI  iuto  th«  bUiod  rvap[>«art  in  largo 
measure  in  the  urine  a*  liippuric  aciJ.  HouHjufaere  in  tlte  body  tfa*  beiuoK 
acid  [ueet«  with  and  combine  with  kIvvid-     And  w«  hara  oicp«riinantal 

{roof  that  the  oombiiiaiiun  may  lutd  j>robsbly  doc*  take  |)lac«  in  tbe 
Idney, 
Ifn  circulation  of  blood  b«  kept  up  through  the  bloodvcBwIs  of  the  kidiwr 
tVeshly  removed  from  a  living  luiimal,  and  benEoic  acid  and  Klycio  be  added 
to  the  blood  as  it  ia  about  to  enter  into  tbe  kidnev.  bippuric  acid  will  br 
found  in  the  blood  isAuing  from  the  kidney,  eapeciaily  if  the  Mune  blood  be 
iwned  through  tli«  kidney  several  timee ;  the  blood  used  must  be  bluod  cud- 
taiuingoxT-luuiDO{i;lubiu,c«rlM>iuc-oxide-hiG[aoKlobin  not  producing  thu  rHvcc 
Tbe  mere  mixing  witli  the  blood  iteelf  is  insufficient;  and  if  tbe  blim«l  bs 
Mut  not  through  a  kidney  just  reruoved  from  the  living  boily,  but  tbrougb 
one  taken  lironi  a  dca<I  body  or  one  which  bos  been  left  to  itwlf  for  some 
lime  af^er  removal  from  a  living  bmly.  the  sjDtbeaia  will  not  bv  cfi^ctvd.  To 
carrv  out  tbe  i-ombinatiou  by  mettus  uf  the  kidney  which  lia*  been  removed 
friiui  tbe  body,  the  kidney  mui>t  retain  for  a  while  it«  own  lite,  it  must  be  a 
"(tirvivinK  "  kidney.  Nor  is  it  absolutely  uocuMory  to  bring  the  benioic 
acid  Olid  glyein  to  tli<-  kidney  by  meona  of  a  blood-ttreiua.  If  n"»urvit-uiii" 
kidurv  be  divided  ra|>idly  into  small  piecca  and  the  bcnxoic  acid  rapidly 
misc^f  witli  the  pieces,  hippuric  itcid  u  forKfed.  Nor  t*  it  nccewary  to  fur- 
nish the  glyciu.  if  bcniuic  acid  hIoiic  Itc  \uvd,  bippuric  acid  b  formed  all 
th«  Mme. '  <«lyctn,  as  we  have  previously  said,  cannot  b«  rwogniied  as  a 
normal  oitstitiient  of  any  of  the  tissuea ;  nerortbeUm,  as  we  have  aeeo  in 
speaking  of  glycocholio  acid  in  the  bile,  and  as  wc  shall  kv«  later  on,  glvcu> 
must  make  a  momentary  ap[>eaTnDce  in  various  nietaliolic  proce^es  or  the 
body.  Wing  immvaliately  on  il«  appeaiBOoe  converted  into  somethiiiii  ehc,  f> 
that  it  iMver  remains  as  ^lyoiiL  It  apparently  is  formed  in  (be  kidney,  and 
is  tbua  momentarily  available  for  tbe  converaion  of  benzoic  into  bippuric 
acid. 

It  seems  prolNible,  therefore,  that,  with  regard  to  thb  poriicuUr  god- 
Milueiit  of  urine,  bippuric  acid,  tbe  cells  of  the  tubntea  hare  iJic  potr«r 
elleirtiug  a  oombiualion  bulwofn  the  beoioic  add  brought  to  ttMin  by  * 


THK   SECBItTtOy  OP  tTBtSlt. 


548 


I 


I 


hUnnX  utul  ibe  xlyciii  wliidi  they  Airiiisli  bv  iii«am  of  (heir  own  inMKbotim, 
bikI  in  iliiit  WHy  produce  hipjiiirio  acid. 

Not  (Nily  beiiEttic  ae'iA.  tint  timuy  <i(iier  bodice  tnk«D  into  the  lystem, 
rcnp[)«Ar  m  ihe  uriii«  ronibioed  with  ;;lvciD.  oml  in  their  csbm  also  the 
comliitiKCion  |>n>bab1y  ttkkts  place  tbnugf)  the  activity  uf  the  cells  of  the 
tubtilM  of  tbo  kidney.  MoriMver,  other  cban^  than  the  naauniptinn  of 
glyvin,  ihft  various  clumgut  which  many  chcmicst  aubsunces  taken  into  the 
sy»l4rin  HiidiTgo  Wfont  rwipjiwiring  in  the  iirine,  [ir'thahly  also  take  place  to 
a  lurcc  •'xlMit  in  ihn  kidney,  aiid  nn.:  aUn  oarned  i-iui  by  i:i«aiia  uf  the 
epithclliiin  of  thv  tiibiiW 

What  other  coit^tiliicnu  of  iiorinul  urinv  an'  produced  in  tliia  or  a  similar 
loanncr  wc  do  not  iw  yet.  definitely  knim,-.  Tlic  pigment  tirobiltn.  which,  an 
we  have  ewm.  i#  «ipw»M  tn  bo  a  derivative  friim  bilirubin,  may  he  brought 
ready  farrac<l  from  liic  liver  or  may  hare  Ihi-  lini«hi»g  ti>iich(M>  ^iveii  to  it  iu 
ibe  kidney  itself:  »nd  the  other  normal  or  abii-trmal  iiriuary  pigincnig  pos- 
sibly ftriM  either  directly  from  hannoglobin  or  iiidirt;cllv  from  ibal  bmiy 
(hroueh  the  biliary  pi^^ment  by  a  Initi^formalioii  taking;  p\aix  in  the  cells  of 
the  tubules.  There  is  also  evidence  in  Tioga  th&t  acid  aodiura  pboephst*  h 
(Urnished  by  the  cella  of  the  tubule*. 

In  oonchiaioD,  then,  we  may  say  llial  the  activity  of  the  epithelium  of  the 
kMi>ey  appears  especially  nioditi«d,  as  comiksred  with  other  secretiug  glands, 
to  meet  the  special  object  which  the  kidney  has  to  secure.  The  purpone  of 
the  kidney  »  not  to  provide  a  fluid,  urine,  which  oan  be  made  uae  of  fur  lh« 
mttd*  of  ihe  body,  but  to  cast  out  wast«  matters  fVom  the  body.  Heuoe  its 
M-crctory  activity  in  limited  largely  to  the  mere  dlschar^  »f  mattera  which 
rcKch  it  pre<>xifttcnt  iu  the  blood,  ihnugU  in  several  cases  it  give*  the  ItnnI 
8ha[>c  to  the  excreted  substance  b^ore  it  puMws  idIo  the  ureter. 

it  421.  We  may  illiislnte  the  preceding  discuiMon*  by  brieflv  puMiing  Ed 
review  »ome  of  the  mot«  usual  ways  in  which  the  wcreiton  ol  urine  »  En 
ordinary  lif«  modified. 

In  the  precedinfc  Motion  the  <vim|HiKiiion  nf  uHne  wa»  illuMnited  by  the 
daily  output  of  ibe  WTenil  oniHtituiMila.  ruther  than  by  a  percentage  account 
of  auy  specimen  of  urine,  for  tbo  rviwon  lliat  the  composition  of  urine  varies 
within  cxtmnely  wide  Umilm.  This  is  c«[>w)ally  the  case  as  regards  the  pro- 
[mrlion  of  water  to  F>ilid».  Ouo  urinr  may  be  of  biyh  gpecilie  gravity  with 
n  small  amount  of  water  nilntively  to  the  solid;,  while  another  may  have  bo 
Utile  color  and  inch  a  low  spi-eitic  gravity  as  to  appear  hardly  more  than 
water.  The  reason  of  these  extreme  diH^nom  lies  in  the  fact  that  the 
kidney  U  uot  only  the  channel  by  which  waste  solids  leave  the  body,  but 
also  an  important  outlet  for  the  discharge  of  the  stream  of  water  which,  iu 
order  that  the  various  procowa  of  the  body  may  be  duly  carried  on.  is  cou- 
tinuully  passing  through  the  system.  It  is  frequently  of  adrantoge  to  the 
body  to  discharge  through  the  kidney  a  large  amount  of  water,  more  or  leai 
imipeclive  of  llie  solid  matters  which  are,  so  to  speak.  wa.Hhed  away  with 
it;  nd  henc«  the  advantage  of  the  glomerular  mechaui^n  no  s[iecially 
adaptfil  for  the  special  dtsoharge  of  water. 

As  wp  shall  see  prenfiitly,  l»  the  iikin  also  falls  tlie  duty  of  disdiarging 
large  quaiililieH  of  water.  The  n«|)irat<iry  organs  also,  as  we  have  seen, 
8pr\'e  for  the  discliarve  of  water;  but  the  amovnit  which  the  latltir  put  out 
csui  only  be  varied  by  the  inconvenient  mHboil  of  incr«uhig  or  diminiiihing 
the  wholi!  act  of  breathing.  Hence  we  tind  KpiTtal  relations  Ixrtween  tlie 
skin  luid  the  kidney*,  eurrvIaltDg  the  work  of  ibo  one  to  tlial  of  the  other  M 
regard*  this  gnuticular  work  of  the  iliscbargi'  of  witlor. 

When  the  Ewdy  is  cxponwl  to  cold  the  ilinohargtt  of  water  from  the  "kin  in 
ch^:)ic<l,  and  iho  cutaurouit  vessels  are  coustriuteti.     At 


J 


544 


TtIK   BLlMlIfATlOS   or   VTASTK   ritODUOTS. 


the  Mrao  timr  llic  blmHlvpiwU  •>!'  i)ii-  tiliil'iniiniil  vUcrni.  incliidibg  the  kU- 
neys.  ■»%  <)ilii(tyl.  but  not  out  of  piMjiortion  to  iW  oitfttrntion  of  ib«  nik- 
oeoas  vcMets,  fur  ilx'  general  lil'>od-pr«N§iir«  <Ior«  n»t  fal}.  )>ut  if  aDjlkin| 
rlMfl  BomewKnt.  Tliu*  ibcr?  iit  trslubiished  juet  the  »tal«  of  tliiD;;^  w^iob  m 
&Tornble  lo  n  full  ntii)  rajiKt  stream  of  blood  through  the  reiial  fclomenli. 
and  an  iucKiu^  How  of  iiriiw  neiilts.  It  is  poteible,  w«  nwy.  jwrban,  m 
(Mobahle.  Ibat  tlie  nen'oiift  Bjeiem  nlTords  a  special  tie  beint^n  tbe  bxia  uii 
the  ki^lnej,  to  ibat  under  tbe  circufitttaiicea  in  ciuealion  iJie  reDal  artcriat  tn 
diUtei)  even  more  iban  thoe«  of  tbe  otiter  alxlottiiial  Tisoera ;  but  ihla  Im 
not  been  proved  ex  peri  mentally.  It  U  also  poeeible  that  br  anotbcrnflec 
mcolianisai  of  tJie  central  nervous  svstam  the  skin  may  work  tipon  iba  kid- 
ney, pot  by  tbe  vsKimiitor  nerves  aloue,  but  also  by  nerves  piveminiL'  tW 
fMretoiy  activity  of  tlie  lubulM :  but  we  have  no  MUiafaoiory  iixticnitoiij  nf 
any  such  mecbaninmi,  and  it  m-t-mn  iiiL<r>-  jirnbablu  that  theconnitction  miouU 
ba  with  tbe  gldmt-nilar  niei'liHui^ni.  ^lll^■-  ihii  chief  object  at  all  evi-iilc  i»  M 
got  rid  of  KUtcr 

Convi-n«:ly,  whtn  ihe  body  In  exposed  to  warmifa  the  ikin  perapirvs  (nth 
and  llw  aitam-ous  vtwel*  are  widely  dilnle<t:  and  conversi-ly  al*!  th«  renal 
aitd  other  ulMloniioiil  v<-n»eU  an^  vunxirictvd.  m  that  a  slow  ami  iininll  slnaa 
of  blood  trickles  tlinAigh  iIk-  ginnioruli,  and  tlw  urine  whicJi  Ja  secreted  k 
scanty. 

^  tiS.  Even  m"Tv  imporlnnt  (hau  iu  relations  to  the  iikin  are  tho  relatiooi 
of  the  kidney  to  Ihc  water  abwrlictl  bv  tbe  alimtsitarr  cainil ;  this  is  eajwci- 
ally  seen  wben  large  iuanlili««  of  fluid  are  dnink.  The  whole  of  the  water 
thus  introduced  into  the  alimciitarv-  canal  pOMce  iubt  tbe  klo<Ml,  for  in  a 
healthy  orji^nism  no  aiDouHt  of  Huid  drunk,  unlcw  it  throws  the  ectMomj 
out  of  order,  can  eflect  the  amount  of  water  present  in  the  feces.  But  tht 
addition  to  the  blood  of  ev«n  a  very  larf^  quantity  of  fluid  do€s  not,  as  m 
have  seen,  by  ita  mere  quantity  (§  1S(J>,  increase  the  K^neral  bloo<i-pn-Murf. 
and  therefore  cannot  in  thin  way  produce  nbat  it  umiimbtedly  doett  pnubiiv, 
an  iocnased  flow  of  urine. 

The  fluid  so  absorbed  may  act  on  Ibe  kidney  iu  two  ways.  Oti  tbt  <um 
hand,  as  we  have  seen  (§  41o),  tbe  injection  of  water  into  the  blood  prtiduM* 
a  local  dilHtioii  of  tl»e  renal  ven«l<i,  as  indicated  by  iJie  sucllin^  of  Ux 
kidiMty.  Thu»  the  al»orptJon  of  mere  water  fmni  tbe  alimentary  caual  may 
stir  up  to  (greater  activity  the  glonit^rulur  iticchaiiiiiiu,  and  tii  so  doina;  nay 
b«  aswtcd  by  the  i>r«seaice  of  various  subataaeoH  alHorlied  from  the  nlimen' 
tary  canal  with  the  water,  for  some  of  these  nlm  may  similarly  lead  to 
dilation  of  the  renal  viiwel*. 

On  ihc  other  hand,  M>me  or  other  of  tlie  chemical  Iwdin  ibuapasrinft  oM 
the  blood  with  ihv  water  drunk  may  excite  the  eccntory  activity  of  tU 
tubuIcE,  aiMl  that  ciiIkt  by  acting  din-ctly  on  the  epilbelium  as  ihev  are  car- 
ried through  the  kidney  in  the  blood  of  the  mtal  artcrin,  or  indirectly 
tbrxiugh  some  inlervenlioti  of  tbe  ceiilml  nervous  sysleni. 

Our  knowledge  is  at  present  too  scanty  to  enable  us  to  dactde  which  of 
these  two  meiliud«  is  the  one  usually  employed  by  the  organism ;  but  tlie 
inordinate  flow  of  urine,  so  poor  iu  soli<ls  as  to  be  little  more  than  wat«r. 
■rhich  may  be  directed  through  the  kidney  by  means  of  an  adequate  "drink 
log  bout,"  would  lead  us  to  conclude  thai  in  such  eawe  ihe  organism,  ulriv* 
ins,  ibougli  too  often  in  vain,  lo  fV«e  itMlflhini  the  evils  to  which  it  w  Mag 
cubjecte<l,  has  reeourse  rather  to  tbe  simpler  flonenilar  tneduinism  than  to 
Iha  more  exjieohive  [iBMie-nastinf;  activity  of  tbe  tubules:  and  the  tirine  in 
nich  cases  pri>biiblv  dioihurged  chiefly  br  the  method  of  dilating  tbe  renal 
vewelx  and  thus  throning  the  poisoned  blood  inio  the  glonirtuli. 

When,  houi^virr,  llui<l  i»  taken  simply  as  a  projier  acoom|iauim«nt  of  mjIM 


THE   SKC'RKTION  OF   tfBIXE. 


MO 


toad,  the  incnaae  of  una«  wliich  ksuIis  trnn  pmlirilily  iiiiDthvr  origiti.  As 
we  have  already  »aid,  nnd  tti  wi;  »hiill  jH>iiii  out  iimix!  fiiliy  liili^r  on,  ihe 
abM>rptioa  of  proteiit  luutxTml,  which  in  ii  cxiii.->ti|iiciit  umI  generally  ii  oon* 
»|)icuou«  i-onstiiiibiit  »f  tivvrv  mviil,  IviuU  u<  n  lormHtioti  of  iinni ;  iind  urm. 
oa  we  have  iweii  n>»»oii  ti>  tfliovo.  diix-clly  "limulalw  tho  <-t)ithi:liuni  of  the 
tubulcn  to  HCCrtitor/  notivUy,  Apd  whnl  «ociiw  prominently  tnic  of  urm  U 
probubty  tniv  of  niitDV  othiT  procltirU  of  iligcslion ;  to  Ihitt  thv  ii)crciu!nl 
How  of  uriiM!  which  foriow*  an  •>n)iiinry  inn)  iKvompflnicd  by  not  morv  thiin 
tb^  ordinary  amount  of  Htiid,  is  tho  result  of  the  liibora  of  the  epithi'litim  of 
th4>  tiibiiln'  a«  well  iis  of  tbe  fuller  stream  of  blood  through  the  glomcruti. 

Ii  423  Whiit  hits  just  beeo  Mud  concerning  the  inRuenee  on  the  kidney  of 
food  itnd  wilier  niny  t>c  np[)lie<I  nleo  to  the  action  of  subatance*:  which  being 
•Specially  ctlicjicious  in  promoting'  n  tlow  of  urioe  when  taken  into  the  body 
■re  c»lle<I  "diuretics."  The  several  actions  of  various  djorelice  are  veiy 
Taried,  and  it  would  be  out  of  place  to  discuss  them  ftdly.  We  mav,  bow- 
ev6T,  MV  thitt  wfai)e  the  action  of  some  appears  simple  that  of  others  is 
complex. 

Such  aicenls  M  sodium  acetate  nnd  pola^um  nitrate  proluibly  produce 
iheir  efl'eec  ohieflr  by  actinf;  directly  uti  the  kidney,  indiieiiifc.  as  we  hare 
seen,  ^  ilfi,  locml  vascular  dilation  and  ho  workiii);  ou  the  glomeruli,  but 
|>ri)bai)ly  at  the  same  time  also  xtirring  U]>,  ai\er  the  fanhiuu  of  uren,  the 
epithelium  of  tJie  luhulee  to  weeretorv  activity,  the  aecomiia Dying  fuller 
Mreuni  of  blood  tbrotigh  Ihe  tvholn  {lidncy  oiAog,  iw  iu  tlH:  cbmi  of  Uic 
mlivary  and  other  ijlaiiiiH,  a  UM-fiil  ndjtiviint. 

The  diuretic  eflW't  <if  such  an  ugi'iit  im  digitalis  U  probably  more  complex. 
Sy  incrMuing  the  cardiac  Mroku,  and  at  the  Mime  time  oouHlrictitig  many 
SnuiU  vcmmIs,  digitalin  rsi«c^  the  g<>ni-rn1  i)lo<iil-iimMUre:  but  tho  tendency  of 
tbe  increased  blood -proxiiri'  to  incrcii>i.-  tin-  flow  of  urine:  may  be  counter- 
bnJanoeH  by  thr  conMrii-iion  of  the  rcinil  vi?«els  iheniulvcti.  And  while  it 
U  n  matter  of  common  i'X{K'rieticr  that  iligitali«  u  Tory  dfectivo  na  a  dinretto 
in  cardiac  dwerotc,  thin-  is  great  douKl  whi-llicr  il  rrafly  artu  as  a  diiirMic  in 
liealih  :  in  <'ar<linc  ili^-iwe  it  prolwibly  miw*  iIm;  b!i»od-pr*n«ure  by  improving 
the  cardiac  Mroko  and  n<>l  by  cmiMriction  of  the  blootlvvMcK  Ditt  even  in 
the  abeence  of  cardiac  dineiin.-.  dii;it»]i«  hiu*  been  found  in  ivrtnin  uiRce  to  act 
<as  a  jkowerfol  •liiircli<-,  nnd  in  th»e  caMe«  either  il  miiKC  act  directly  on  the 
tubular  epithelium  or  il*  iHcets  in  eonglriclini;;  ihe  renal  arteries  must  be  (eSB 
than  its  effecia  on  other  small  arteries  or  mma  iituo  olf  before  tbe  inHuence 
of  tiie  heighleneid  blond -prenti  re  has  dimpiteared. 

§  424.  Quite  removed  from  the  intervention  of  chemicnl  substances  in  tbe 
tihvxl  and  yet  m<et  striking  in  the  iutlueneo  on  the  kidney  of  the  ceniral 
uervoiis  system.  Tbe  potent  influence  of  emotions  in  promoting  the  socre- 
tion  of  unoe  is  proverbial,  and  the  general  features  of  "  nervous  "  urine,  the 
water  increased  out  of  proportion  to  the  solid  constituents,  eapeeially  seen  iu 
tbe  "iiriua  byaterica,"  which  is  hardly  more  tban  umple  water,  often  dis- 
ebarget)  ill  c]K>nnous  ipinntity,  at  once  suf^eais  Ihe  vievr  that  iropulMS  oHgi- 
tinting  In  tlie  btain  and  paaaing  down  to  llie  kidney  along  the  vaao-dilator 
ihrtt,  of  whuM  existence  evidence  was  given  in  ji  414,  lead  to  dilated  blood- 
VMMband  gie*t  play  of  glomerular  activity,  witbuut  perhaps  produeiugajiy 
otbtr  dirf«t  effect  on  the  economy  :  (bough  pudsiblv  the  same  emotions  by 
oonairieting  tbe  cutaneous  and,  it  may  be,  other  veteels  may  raise  the  genenti 
bhxxl'prrMiure  and  *••  help  the  dilated  renal  veMels.  In  the  coMof  tbe  uriiM 
of  bytu-ria  we  are  li-uipii-il,  more  perhaps  tlian  in  any  other  iiulancQ,  to 
accept  tbe  hint  prcvi<iu«ly  thnmu  out  that  il  b  giowible  fur  the  rata  afibr- 
eutia  of  the  glomtnin  to'  be  alone  dilated,  so  that  tbe  gr««ter  part  of  tlio 

S6 


546  THE    ELIMIXATIOX    OF    WASTE    PRODCCTS. 

renal  bl<><id  is  directed  to  the  glomeruli  and  the  epithelium  of  the  tubula 
left  in  its  iistmt  quiet.     Itut  thi^  ii  as  vet  pure  B|>eculation. 

Thk  Discharge  of  Urine. 

•t  42fi.  .'ilrurlure  of  l/ir  iirrter.  The  ureter,  like  the  large  ducts  of  other 
glands,  CDiiifist  of  an  epithelium  resting  ud  a  connect ive-tisaue  basl^  Btrength- 
eiii'd  with  plain  muiM-ular  fibres.  The  epithelium  is  iu  its  characters  iDter- 
mediate  between  that  lining  the  ces»phugus,  which  as  we  have  seen  (§  221) 
rcsemlilcs  the  epidermis  of  the  skin  and  that  lining  the  ducts  of  the  glandi 
of  the  ulinienturv  caiinl.  It  couxiBts  not  of  a  single  layer  but  of  three  or 
four  layers  of  celU.  The  luwernuKdt  cells,  next  to  the  baeement  membnue 
which  limits  the  cod  ne<:tive-t  issue  basis,  are  oval  cells  placed  vertical  I  v,  in 
one  or  two  layers.  The  cells  of  the  next  layer  are  irregular  in  form  aod 
ofieu  |iear-i«hapod,  with  a  narrowing  process  dipping  down  between  the  celU 
below.  Above  these,  forming  the  i^nrface  of  the  epithelium,  is  a  layer  of  flat 
or  of  flattened  cubical  celU.  All  the  cells  are  nucleated,  and  there  are  do 
special  features  in  their  cell-stiljstnnce. 

The  connective  ti^ue  is,  av  in  a  mueons  niemhrane,  delicate  iramediatelv 
IkIiiw  the  enithelium,  but  l>cconics  coarser  and  more  fihniue  in  ii£  out«r  parti 
The  muscular  fibrfs  are  arranged  in  three  liiyera,  an  inner  loagitudinal,  i 
thicker  middle  circular,  and  a  thinner  less  n-gular  outer  longitudinal  layer 
lietter  develo])e<l  in  the  lower  juirt  of  the  tube  than  elsewhere. 

Nerves  jiatw  into  the  ureter  at  the  ui)]M.-r  end  from  the  renal  plexus  and  at 
the  lower  end  from  the  s{>ermatic  and  hyjiogai^tric  plexuses,  and  at  the  two 
ends  nerve-cells  are  scattered  anion>!  the  nerve- lib  res. 

The  jielvis  of  the  kidney  is  an  expansion  of  the  upper  end  of  the  ureter, 
anil  is  lineil  by  an  epiihclium  like  that  of  the  ureter,  which  is  continued  ioio 
the  calyces  and  over  the  projecting  |>a|)tlUe  of  the  pyramids.  The  circular 
muscular  Hhrcs  of  the  ureter  are  continued  over  the  jielvis  but  form  here  a 
relatively  thinner  layer,  while  both  longitudinal  layers  are  very  scantr  and 
graduulty  become  lost. 

At  its  hiwer  end  <'uch  ureter  ojiens  hy  an  oblique  opening,  serving  aa  a 
valve,  into  the  cavity  of  the  bladder. 

S  488.  aii-Hchirc  of  (he  blaililer.  The  e]>ithel]um  of  the  bladder  reaemblea 
in  its  characters  that  of  the  ureter,  but  the  ap|H-iirauce9  presented  by  the  celh 
in  sections  of  prcpareil  bladders  will  imturully  vary  a  good  deal  aeeordiD); 
as  the  bladder  was  hardened  in  a  coutruuteil  or  in  a  distended  state.  Thii 
ejiithclium  with  the  underlying  fine  (.-onncctivc  tissue  forms  a  mucous  mem- 
brane, separated  by  submucous  itinnective  tissue  from  a  well -developed  mus- 
cular coat,  which  in  turn  is  investe^l  with  an  outer  coat  of  connective  tiasue 
cuverul  over  the  greater  |«rt  of  the  organ  with  |H;ritoneum. 

The  wcll'<leveloped,  i>laiu  muscular  libre-ccltH  which  constitute  this  mua- 
rnlar  coal  are  gatlicrwl  into  rounded  bundles  or  flattened  bands,  which  in 
turn  are  arranged  in  a  plcxiform  manner,  being  btmnd  together  by  con- 
nective tissue  carrying  bloodvessels  an<t  nerves.  The  direction  of  these 
buiidh«  is  not  very  regular,  hut  they  may  lie  regardcil  as  forming  on  the 
inner  side  below  the  niucouK  membrane  ii  circularlr  disposed  coat,  better 
drreloped  at  the  lower  part  of  the  bladder  amuml  the  oj>ening  of  the  urethra 
tku  elsewhere,  and  outside  this  a  longiludimilly  disposed  luat.  the  loogi- 
ndinal  direction  of  the  bniiilles  lioiiig  belter  seen  at  the  front  and  back  than 
M  tW  aides.  Many  of  the  bundk's  and  nelwnrksuflninclles.  however,  in  both 
<m»  nin  >  c<>urst>  which  is  neither  exactly  lun^ritudinal  nor  circular.  The 
■Mr  Vwgitudinal  coat  of  the  ureter  apjieurs  to  be  rejiresented  bv  a  very 


617 

thiu  und  inmuHiKtiotis  \t»ytr.  Thi-  thicker  nnil  better  developed  portion  of 
chf  drculitrlr  tlis[KiM<I  cuat  is  eotDotiiiice  epokeu  or  m  ih«  mhiiuiter  rftictt, 
anil  llie  longiliulinnlly  <li8prei.il  cmt  t»  similarly  aoinetira«s  calfe'l  the  defriuor 
urinir :  Init,  ae  ire  Bhall  pee,  |Iim«  names  are  uudeairable.  In  the  ttog  th(i 
lonptudinal  butiillcs  are  mucli  belter  developed  tlinn  the  circular;  but  tlic 
relative  projxmion  of  the  two  eets  of  bunttlea  eeeius  to  varjr  in  different 
aniniabi. 

The  bladder  b  sujiplied  with  iwrvea  (torn  the  liTposasiric  ])lexti3,  tli«  fibrw 
beiuff  both  mediillaied  and  non-meiluUated.  They  ap{>Mir,  tu,  in  the  cue  of 
Ibe  rectum  (§  277 ),  ii>  have  a  double  ori^n.  dimiiiL'  (lO  (lie  oite  linnd  from 
llie  lower  <I')r«aIaud  upper  lumbar  spinal  curd  ibri>uKli  (lieiynipaibeti<'«y«tcti], 
and  on  ihe  other  hand,  in  a  more  direct  manner,  from  tlivwifrsl  spinal  nervee. 
More  abundaut  nmniid  th«  neck  uf  ilie  bladder  than  biglu-r  up.  they  run  at 
iir«t  in  th«  outt^r  oonnective-tiioiic  iiut  beneath  the  pt-ritoucuni  and,  funning; 
pIcxiiMf.  iillitnalcly  end  piirtly  In  the  hloodvocicU  and  partly  in  the  muii- 
cuUr  tibrcs.  tli'iiigh  iH>m«  fibrus  are  wld  to  have  been  innvd  to  (be  epithe- 
lium,   f iri>u|M  "f  nerve-cell*  occur  on  the  pkxneM,  espi-ciallv  ni-ar  the  neck. 

■j  427,  Tbc  oriuf.  likr  ihc  hile.  i«  Kicrcied  <>ontinumMly ;  tfjc  flow  may  rbt 
aix)  fall,  hul  in  health  neror  atwotutely  cciuc  for  any  length  of  time.  Th« 
<-i-*Hilii>n  of  renal  activity,  the  km^IIm  Mipprewion  of  unoe,  entalb  apeeily 
death.  The  minuie  »treHiiii>  pouung  continuously — now  aion>  rapidly,  now 
more  slowly — at'ing  the  collect  inc. ind  discharging  tubule*,  arc  i^thorvd  into 
the  repal  pelvi«.  irTicm-e  the  tluid  is  cxrriitt  aloug  the  ureters  into  (ht;  blad> 
<h»r  partly  l>r  prcMtire  and  gravity,  and  from  time  to  itmv  partly,  as  »«  have 
alrendy  said  (§  416),  by  th«  peristaltic  cantractiona  of  the  muioulnr  walls 
of  the  tireter. 

If  in  a  liWDR  animal  a  ureter  be  laid  bare  and  nimutated,  mechanically 
orulherwiM,  at  a  part  of  its  course,  ware^  of  periotaltic  contraction  may  be 
aeen  U>  pass  in  both  direcltitis  from  the  snot  nimulated  upward  toward  the 
kidney  and  downward  the  bladder.  In  toe  abaeoee  of  artificial  stimulation 
i<{ir»ntaDeou«  waves  of  contraction  make  theirappearauce.aometimes  repeated 
with  tolerable  re^laritr  (abnut  every  twenty  aecModa  in  the  rabbit),  aome- 
tln>M  occurring  in  jrroujid  with  longer  pauM«  between.  Those  MKHilaneoui 
contractions  invariably  i>aM  in  one  direi^iiou,  from  the  kidney  to  the  bladder, 
and  their  rmpieuiTy  and  vij^or  seem  to  be  determined  by  the  activity  of  Uie 
Mcrt'tion  of  urine.  But  they  ar«r  not  directly  called  forth  by  ibe  urine, 
either  mwhaiiically  diMendin);  the  till"-  'ir  chemically  stimulatms  the  inner 
surface,  for  regularly  reoirriuK  <v>n  tract  ions  may  be  obwrved  in  a  kidney 
iind  unrtcr  removc<l  from  the  body,  or  even  in  an  isolated  excised  piece  of 

tthe  ureter. 
The  rhythmically  repealed  contractions  arise  spontaneously  in  the  miia> 
oular  coat  of  the  ureter  much  in  the  nmu  way  as  tbc  similar  cartliac  coo- 
tradiotia  arise  in  the  muacular  mibstancc  of  the  lifwrt ;  and  it  may  hen  be 
raentioned  in  support  of  what  was  iirg«d  in  ^  i't-'i  ivith  re^nl  to  the  hc«rt- 
beals  not  beinf;  M4irled  by  nerve-cells,  that  rhylhraically  re|)eated  sjioHliincous 
neristallic  cnntmetions  have  been  ohwrved  in  isolated  pieces  of  ureter  taken 
mm  the  middle  of  its  course,  in  which  uo  nerve-cells  and  indeeil  no  dij>tinct 
nerve-fibres  could  be  obaen'ed. 

In  the  living-  body  Ihtse  spontaneous  movemeols,  beats  they  might  Im 
enlird,  are  subordinated  to  the  flun-  of  urine  into  the  pelvis;  the  more  active 
the  iMtcretton  of  urine,  the  more  fre<|uenl  and  vi>;orous  are  the  bcwis  of  the 
pelvis  and  ureter;  but  the  exact  mechanism  by  which  tlte  Mcretiou  and  the 
jDorsnunts  are  autintaincil  in  liarmuny  lina  not  yet  been  cleareil  up. 


I 


648 


THK    ELIMINATION 


PRODUCTS. 


MirtHrilion. 

$428.  In  the  urinary  bUd<ler  ibe  uriii«  a  coIIucim),  iu  raturn  iob)  ik 
tir«ivra  beio)^  ]>revetileH  by  Um  oblique  entrsriM  iiilo  llif?  Iitiukler  niii)  vain- 
lar  iiaiure  of  ilit  oriticea  of  Utoee  tilbe»,  and  il*  di-chitrge  (rvnt  llieocr  io 
CMKftderable  uuantily  ia  ertcoiwl  fr.mi  time  to  tinio  bv  a  ^lucH-bai  cumpifi 
muMular  inecbaniain,  of  the  uiUure  and  workiof;  of  whit-h  i1m>  followtuij  isi 
brief  aucouut : 

The  iuvoluDlnrr  luiiacular  tibrea  forming  iJk  ^realer  part  of  the  vatctl 
mill*  are  arrnii|j:vd,  a*  we  Itare  nid,  {MUtly  iu  a  ii>»re  or  loa  toriuiiuitiiul 
direction,  and  |Minly  in  a  circular  manner.  Afler  it  Itaa  been  eiitpti<>*l  th) 
b)ad<lvr  ix  oxilnu-UKl  aod  ihruwn  into  foliU ;  lu  tbe  tiriiie  fcradunlly  oul1i>i.i>, 
llio  blBd<l«r  b«wuiDea  mure  aat\  uihk  t)iUeu<ted.  Tli«  e«i-a)i«  of  tb*-  (luid  i>  ia 
]iart  iirevcDU^d  by  tbe  reaiatance  olKired  by  tbe  eJaiiii;  ^brua  in  tb<>  wulla  of  ibc 
urvlhra,  nhidi  lielp  to  keep  the  urethral  ehaiidel  clo^^d.  But  tbia  ia  iiui  all, 
for  ohwtrvitlion  »bi>««  that  fluid  'n  retained  vritbin  thi>  Itlatblrr  up  tr>  A  pn»- 
ture  of  twuiily  incliva  of  mater,  to  long  an  llie  bladder  ia  )|[»v(-riioil  by  aa 
inlnct  Dpiuiil  c»rd,  but  give*  way  to  a  nreMure  of  aix  inehc*  only  whvn  Un 
lumbar  spinal  coni  i«  <b5'trovetl  or  the  viyucal  m-rv)*  are  *t.-vurcd.  TU 
aRorili>  vm~  ttrong  rvidciuf  ifiiil  tho  oWtnioti-ni  al  tbe  ncok  of  Uw  hla*iil(* 
to  the  «xit  uf  urino  dopendx  on  fonic  Kiiiit-  niudcular  i-ouiractioD  mnjatsitwd 
by  a  reflex  or  nuloiDnttv  action  of  thv  lumbar  K|)inal  (M>rd.  And  it  ba^baoi 
maintained  that  it  i»  the  circularly  dispuacd  fibrot  apocially  d4'v^I(>|K■'J  nr<itiad 
the  neck  of  the  bladder,  which  an;  the  aubjects  of  this  tunic  con trae lion  aal 
thus  the  chief  cause  of  the  intention  ;  h<'ncr  the  name  «^bincter  vesioK.  IV 
voniinuity  of  tlieae  fibres,  however,  with  the  reet  of  the  circular  fibres  t>f  tht 
bladder  sugiteeis  that  ihcy  probably  do  not  net  n<  ii  sphitu-ter.  but  ihat  tbur 
une  lies  in  their  coDtraciine  after  tlie  rest  of  the  veaicul  fibres  and  tku 
fiiiifhiiiK  the  evacuation  of  the  bimldcr.    Tbe  resistance  in  i{ue8iioii  b  sun- 

I  died  by  a  tonic  contraction  not  of  th«ee  circular  fibre*  of  the  bladder  itM«, 
Hit  of  the  muscular  fibres— partly  plain.  {>artly  striated— surrounding  (br 
prostatic  piirtiou  of  the  urethra,  and  cousliKlliDg  ihe  ^fhinrtenvjiint  Fxl'-mut 
or  pi-iul<ttinii',  or  ajihiucter  of  Henle.  It  ia  stated  that  artiticiallv  exetted 
<.'»n  trail  ion »  of  ihi-ne  fibres  will  rei^ist  a  pressure  of  fluid  in  the  l>la<l(W. 

When  the  hind'ler  baa  become  lull,  we  feel  tli«  need  of  making  water.  Ok 
eaoaation  being  hcitilitem-d  if  not  eaused  by  the  tricklinii  of  a  lew  drop*  of 
uriiM)  from  the  fiiH  blsddi-r  iuiu  the  urethra.  We  are  then  consctuits  uf  an 
eflbrt:  during  ihiv  dfort  the  liladder  ia  thrown  into  a  lonirLonlinuisI  con- 
triiclion  of  HU  olim-un-'ly  {icriidaltie  nature,  tlie  force  of  whicii  in  more  ibna 
8ulfid<.iii  1^1  oventinir  ilio  n-ii.->lunce  oflbred  br  the  urethra,  wwl  fht'  atim 
imues  in  a  stn'ani.  lli<^  •phincli'r  vcMneexwmuaueiugul  iheHunc  tiniii  I'ltbif 
relaxes!  iiflcr  ih^^  tiuhiou  of  the  M>hincter  ani,  or  ailemt  overconx'.  lu  iu 
paMiige  along  Ibc  urethra,  the  exit  of  tbe  urine,  at  nil  evenlf  of  thr  last  pM- 
tiom,  is  lorwardwl  by  irregidarlv  rhvtliniic  omlractioni'  of  tlw  bullju-cavcr 
DOHis  or  ejni'ulnlur  uriuic  niii>clc.  ifie  conlroetioiu  »f  which  ciiiipn-es  ihu 
urethra  ;  and  the  wh'dc  net  i*  further  muiKled  by  precnre  on  t}ti-  bladdsr 
exerted  by  means  uf  tbe  nbdotniiial  muscle*,  very  much  the  snine  a*  is 
ddiMMitiain. 

In  the  esse  of  the  rwtum  we  were  able  (^  277)  to  distinKuish  between  tk( 
MOtioas  of  the  longitudinal  and  of  the  cin'ular  cimU.  luxl  we  Mid  that  tbt 
two  coats  liad  di*linet  nervous  supplies  (Fig.  l'Jt>).  The  bladder  has.  as  wt 
have  said,  a  Mmilar  nerve  supply,  and  it  is  very  prubnble,  hut  iii>t  yet  dis- 
lluctly  proven,  thni  this,  like  double  supply,  bas  a  Itke  <l<>ub]c  action.  Stimtt- 
Inii')U  iif  the  branchr*  coming  from  tlw  sneral  nerves,  at  lh<^  same  tinifl  tint 


"  Uiium  thr  Km^rilniliiml  tiiai  i.f  ilic  roc-lurii  iniii  rontnictiMU,  brings  aUuil 
'B  ci>*  iUifi.  iu  whirl]  the  loRKiiiKliiiiil  lilin'«  of  iho  hiNdtUir  mre  niii<.-li  mora 
flMfMiiK-nl  thu  tbo  cin-iiUr,   powcrrnl  vc«iral  miilriutiunH.      )Ior<<over, 
tlataliUHdi  <>r  lh»  Mcrnl  n«ivv«  on  otw  rvU-  producvs  uiiil«t«ntl  mjotrai-tioa 
oC  thr  ttUilik-r.     Fn>i»  thi»  we  mar  inf«r  thnl  (he  mcrnl  nerves  govern  the 
*OQ|titi)<lituil  c)«l.     KlimulBtion  ol  th<-  hr|>nsguttric  norvcs  cnrryLoe  Bbrae 
A'i'ni   tlir  ilonail  luii)  upper  lumbar  oml  (mv  Pi);.  ]'H)),  irhili>  thfotruiK  lh« 
Ctrculmr  cjhI  of  the  rct'tiim  into  elrong  coninietion^,  gives  rieo  to  mieal  con- 
tliMtticHn,  but  the«>e  lira  )ir  no  meuiis  fo  nmrked  at  tlioee  wlticli  sp|icar  wlieii 
Mm  axmil  ucrvm  ara  Hliiuiiinied-     We  may  probably  Ly>nelu<le  that  ibe  Piore 
■niportaiit  tibrea  in  the  fnntlus  of  the  bladder,  whicb  ara  for  ibe  nioM  put 
loDptuiiinal,  ara  to  be  rejuanled  aa  goTeraed  for  the  moat  pari  by  ihe  Mcral 
■MTve-iibn^.  nhile  the  circular  rouMiular  fibfes  around  Ui«  neck  of  tbe  blad- 
der, wfaoAC  cnntracli^n  cufupletat.  lu  it  were,  the  emptying  of  tbe  bladder, 
Ar«  tIttMe  ou  which  (he  byputraeiirii-  nerve-fibree  have  tbe  chief  influeiMje. 

^  429.  We  Mid  juM  now  "  when  the  blndder  iiaa  becwne  fuli,"  hut  tbb 

iniii4  Dot  l<r  underehiud  to  mean  "  when  the  blailder  liaa  received  a  certain 

niutntiiy  «<' Ouiil."     Ou  the  i-imtrurr.  it  is  n  matter  of  coraiium  ex [wrivnctf 

tluU  w«  Utl  the  di3iire  to  luukc  wuier  iuiuieLime*  when  a  lur){e  i]uautity  and 

■oimwiiw  when  a  iimall  iiuantitv  of  urine  has  accumulated  in  the  bln4tdcr. 

AVe  have  cvidenec  that  Ine  hlailder  poaacaaai  lo  a  very  high  decree  Uiat  ob- 

•curv  eoatinuoua  coDtraottMii  which  we  tpeak  of  as  "  tone  "  atui,  funber,  that 

th»  amuuiil  of  its  time  is  cxcreitinifly  variable,  the  organ,  quite  inde])end' 

«otlT  of  dintinct  rfliirtit  at  micturiiioii,  bciiifr  at  otic  tim«  contracted  anil  at 

mnoltier  flaccii)  an<l  iliMCmled.     When  it  ii>  in  a  coiitractMl  Kale,  a  smaJl 

ILianlity  of  Suitl  mnr  exert  the  muic  clfi^  on  (he  vtMcnl  walls  as  a  larger 

<|uaatiiy  when  the  bladder  io  fluedd.     Hi-um.-,  while  ihv  drtvrmiiting  cauw 

of  tbe  deoire  to  make  water  is  tin;  prcsture  of  the  urine  upon  the  vesical 

walls,  the  quauliiy  needed  lo  produce  the  necessary  fulneae  K  dependent  ou 

the  amuunt  of  tonic  contraction  of  the  muscular  libr4M  enstiof  at  the  lime. 

Awt  we  have  evidence  that  this  lone  is  regulated  by  the  nervous  aysteiu. 

(430.  Micturition  as  sketcheil  above  wema  at  firat  aght,  and  capecially 
■tuna  we  appeal  to  our  own  con^^ciouHDese,  a  puivly  voluntary  act.  A  volun- 
tary rfliirt  thiuws  tbe  muscular  fibrm  of  the  bladder  into  conlraolioiu,  an 
hruoipanvini;  vuluninrr  efli>rl  leeaena  llie  bme  uf  the  sphincter  extcniut, 
)ut>lMlilT  i>y  inhibiting  >t'^  oenlrv  in  the  spinal  curd,  while  other  voluntary 
fdna  tlirow  the  ■■iacnliilor  and  abdominal  luuiicles  into  oonlractioiu,  and 
I&e  ra^istanne  of  the  urethra  iM-iug  thereby  overcome,  iheexit  of  tlw  urine 
(Utlurally  foHowa. 

Tbrrv  are  facta,  buwcver,  which  prevent  the  acce]>tanoe  of  Mtimplu  ariev. 

In  tKe  6ni  plnce.  in  caan  of  urethral  ohslniction,  where  tlie  bladder  cannot 

lie  •niitiM-<)  when  it  rcechtv  it«  acciMl'imed  ftilonw.  ilw  incrvasing  (listenUoo 

ijaU  up  fniitlMs  ImU  powerfnl  contntcti<m]i  of  tbe  ve«ica]  wall*,  conttactioas 

vrbtch  are  dearly  involuntary-  in  nalura.  which  wane  or  dixappcar,  and  return 

AK^in  and  again  in  n  rhythmic  innnDcr.  and  which  may  Iw  m  strung  and 

|H>w-erful  u  ID  cause  graai  •ullVriDg.     It  spi-iii«  that  tbe  lihres  ot  the  bladder, 

like  all  other  museulnr  libres.  have  tltnr  •■•mlrnctionii  augmenitvi  in  pnipor- 

tion  M  tiiey  are  'ubjecled  [n  lcii»ii>n.    JuM  as  a  previously  iiuie^eenl  ventricle 

«r  a  frofc's  lieurt  may  be  excilnl  to  a  rhythmic  beat  by  dixicndint:  its  cavity 

with  blmid,  *>  ihe  •juiesceni  bladder  may,  i|uite  indepcndeni  of  the  will,  l>e 

*scilr<l,  liv  tlie  disii-iiniun  tf  its  cavity,  to  a  peristaltic  action  which  in  normal 

(■act  i*  never  carried  beyond  a  first  cITorl.  liiioe  with  that  the  bladder  is 

MBUied  and  tlw  rtimulus  is  renmvcd.  btil  which  in  casea  uf  ohatniction  is 

(Babied  clnrly  lo  raanifesu  iti  rhythmic  naiure. 

In  tbe  Meoad  place  it  bus  iJeeu  tliowu  that  <|uite  normal  micturition  may 


MO  THK   BLIMINATION'   Ot   WA8TB   PROPtJCTS. 

lake  tilitce  iu  «  4lng  iu  whk-li  tlw  htnilmr  r«^on  of  (He  apiiial  curd  bw  bwo 
coiiiplpi^lv  kikI  |<«riiiancnilir  weiwnim)  by  Mvlioa  Aroix  tho  Mi>|M>r  dunl 
re^rioo.     I"  xiicU  a  oiiw  iben-  can  t)«  an  txvmm  nt  volition,  miil  th«  wlxJe 

Erocew  appeani  am  b  n-flci:  iictiiii),  Wkni  tmiWr  thcM  cinmniKtancaib 
liulder  D«e<in>i.-»  TiiM  (an<l  othurwiMi  ii|i)iur<.-iitly  tl>v  ad  liiilf)  unv  mUrM 
vlimulii*.  viicli  an  opnnging  lli«  utiitt  or  >li^ht  |>nwurt>  on  iho  ubtlniiilml 
unllo,  mi>*i'  a  romptrto  act  of  micuiritMii :  tlve  liladdvr  i»  •.-ntircly  emptJnl, 
HD(1  iW  »trrnni  of  urine  tottnnl  ibe  vaA  of  llw  net  und«rgo««  rhyttimnl 
augmcntntioiu  due  to  oontnctiotifl  of  the  ejaculator  tinoie.  These  fwu  nn 
ODly  b«  interpnied  on  tbe  vi«w  that  there  exi«ls  in  the  lower  spinal  cnni  (uf 
the  ilog)  what  ne  may  speak  of  u  a  micturition  nntte  capable  nf  beinn 
tbrovn  into  action  by  appnipriate  aBerent  impulses,  tlie  action  of  ib«  cmlrt 
beiDic  sucb  flfl  tu  cause  a  coniraoliou  of  the  iralls  of  ibe  bladder  and  of  the 
ejaculator  urtnw,  ami  at  the  raiuu  liro«  to  auspend  the  tone  of  iho  apblocMr 
Teaicie  extemtu.  CHuical  vxperience  aUo  ^o»  to  show  the  exutoaoe  of  ■ 
■itoilar  micturition  centre  in  nian,  plBcc<l  liigher  up  id  the  cord  (ban  lb 
corretpoudinK  "  Ktuiital "  centre  goveniinK  the  jtetiital  oiYao*. 

Moreover,  w<- lini'e,  in  the  ciwe  both  nt  man  and  of  ocher  anininlii,  eipwi- 
menial  nnd  o[h«r  <;vid«ncn  that  emit ract tun  i)f  the  hlailder  t.t  fn<i{ueMlT 
brought  itliciiii  liy  rcllcx  action.  Thii>  \\\«  prtrwurv  iriibin  ihit  bladder  wbni 
oWrvcd  for  iinv  length  of  tinir  in  found  to  Xtv  irnhjed  to  ninxidcraldv  anl 
nianifold  vfiriiitinns.  Over  and  nlmvc  |mk<>vi.'  i-haiigt«  in  prwnuiv  <Jiie  tii  ll« 
mpirntor)-  movi'mcnttt.  ihnmgh  whii-li  iW  lilaild«r  i*  prr"H*il  ii[»i«  at  oadi 
dNCrnt  of  the  iliiiplimgtn,  nr<ivt<  i-<>iilrartit>it«.  nf  a  drrngth  iiiadcqunle  Iu 
bring  about  micturition,  nre  from  lini*'  to  tini«  oWrrct).  Tht^n  in  eoiM 
imtBDCw  a]>pear  to  be  sgwiitanoitii,  or  to  be  ihi-  r««ult  of  emotions,  but  tber 
may  be  readily  induced  in  a  rcRex  manner,  by  stimiiliiling  vnrious  seutieiil 
fUrfaces  <>r  »eiwory  nervei.  And  cotiimon  exjwrieuce  afliinU  many  iitataixts 
where  veucal  coutraciiouH  thus  brought  about  in  a  reflex  mauner  aoqain 
airenglfa  adeijuate  to  empty  the  bladder. 

Obcervntion  of  vMical  prcMure  may  be  tnont  onnvenictilly  carried  out  \>y  latn>- 
tlucioi;  into  ihr  Iilailder  a  mtbetrr  coonrcted  with  a  water  manomoCcr  and  ■ 
rrt!>!ili'riiiK  ■ppHmtiti.  nnd  to  luranged  lu  to  alluw  fluid  to  tie  driven  into  wr 
received  Irom  the  tdadder  ui  |iteu«ure. 

$  431.  Involuntary  raicturilion  obvioui>ly  of  reflex  nature  ha«  frequentlf 
been  (d>!«rved  in  cam's  oC  pamlysia  from  diseawof  or  injury  to  the  apinu 
cord ;  and  the  involuntary  micturition  which  is  common  iu  children,  aa  the 
reoiilt  iif  irritation  uf  the  )>eiiiii  and  gtitiiial  organs,  and  which  sometimei 
ovcuni  iu  tl>e  adult  aa  tbe  result  of  emotions,  or  at  least  senaory  imprewioBi, 
np|M«ni  to  l>e  the  result  of  rf^flex  action.  In  tbeee  several  caaee  we  mar 
fairly  auppoee  that  the  centnt  iu  thi;  »i>inal  cord  ia  aflecied  by  afl^reat 
impulaee  renchini;  it  along  variou*  twiivury  nervM  or  deM<tndiug  tmra  the 
bntin,  Hencr  wo  are  W  tu  the  conception  that  when  wr  make  water  by  ■ 
cousctoue  effort  of  (he  will,  what  occure  in  not  a  diret^t  atriton  of  the  will  im 
the  mUHcnlnr  walls  of  the  bluddt'r,  but  that  iuipuUm  Planed  by  llw  will 
dfec«ud  from  the  brain  after  the  taHhioit  of  iiHcnnc  impul*e«  and  thita  in  % 
rellex  manner  throw  into  action  thi'  micturition  centre  in  Ihvxpinal  cord.  W« 
may  draw  an  analogy  between  the  micturition  ajiparatus  and  the  respirulorr 
mechanism.  We  sair  maona  in  the  latter  ea»e  to  ihiuk  that  wlivn  the  will 
interfered  with  the  reapiralorr  movements,  it  did  so  by  acting  up«)U  the  ner- 
vous meclmnisin  in  the  eeniral  nervous  system  and  not  by  acting  directly  oa 
tbe  muscular  Abrn  of  the  diaphragm  and  other  respiratory  muKles.  And 
ibe  ewe  of  the  plain  muscular  tibres  of  the  blwlder  erams  even  stronger  than 
that  of  reapiraiory  musclea  so  largely  skeletal  iu  nature.     We  might  alao 


RUCTUBE  OF   TOB   SKIN.^ 


I 


I 


logy  wllh  thu  iM-iirt.  We  nrei  nul  able  to  throir  Into  ncUon,  \>y 
Mr  dinet  eflurl  of  tbo  will,  the  i.-mnii«i;!  uiigmcmlnr  mcchnnism.  Were  we 
*wt  lo  do  H  povrerfullj  miiI  Mi(](li<iily,  ito  miirht  llirow  in(o  viulent  action  & 
■takljr  boathie  htArt  mucli  in  lli«  Mime  nay  ihftt  vrc  empty  nn  ohwuroly 
toQtnMrting  bliuMer.  Nor  i«  thii>  view  ncgntivod  by  the  fnct  that 
|i&n)y*i«  uf  Ibc  blaiUler,  or  nitlivr  iiinbility  to  mak«  water  either  voluntarily 
pr  ia  a  rvflex  m»nner,  i*  n  common  eymptom  ol'  cerebral  or  «pinnl  disesMc  or 
uijurr.  Putting  aside  the  cases  iu  which  the  rellcx  act  is  not  eallod  torlh 
b«^c«u8r  ttte  appropriate  stimulus  baa  not  been  applied,  the  future  in  mictu- 
■itioti  under  tbese  cireurastancea  may  be  oiplainvd  by  BUppooiDg  that  the 
AlM>ck  of  the  sfitnat  injury  or  some  exi^naion  of  the  Hiseaae  lias  rvnilored  the 
•piluU  ceDir«  unable  to  act. 

TIm  ao-called  iiieontineni'e  of  urine  in  children  is  simply  an  easily  excited 
and  firequenlly  repeated  reflex  micturition.  In  caaoi  at  cerebral  or  spinal 
<!!■«*■«  a  form  of  incontinence  is  frefjueiUly  met  with  which  seenia  to  be  of  a 
dtfl^r«nt  nature.  The  bladder  becomiiif;  full.  but.  owiu^  to  a  (kilure  in  lira 
meohaiiijiu  of  vulunlafy  or  reflex  mietiiritiun,  being  unable  to  empty  itadf 
by  K  cinuplele  cuniniction,  a  coniinuiil  dribbling  of  urine  laltes  place  through 
t.lao  uretlin,  the  lulnen  of  the  bladder  being  auflicieol  to  orervoue  the  reHat- 
MBOe  M  the  ueck  of  the  urethra.  It  in  pn)tiable.  however,  that  even  in  these 
«aaai  the  How  i*  partly  caused  by  obM'iire,  tiufelt,  inlrinnit:  controvticitu  of 
«1m  bladder. 

i  4S8.  \\lM)ther,  under  normal  eunditioiu,  the  unnc  undeigoea  any  notable 
^MBga  during  ita  nUty  in  tlie  bladder  baa  been  much  debated.  Experiments 
Aowlbat  pi>i»<>ni>ii»  Mibclances  intccied  into  the  bladder  with  all  due  care  10 
avoid  aiir  ahroNon  <if  the  I'pitheliiim  arv  almirlM-d  and  nnuluoc  thdr  usual 
iBklS.  It  ha*  ulwi  U-eu  Milled  that  if  a  Koluiion  of  nrca  W  injocted  into  the 
bladder  after  ligature  of  both  uit^tera,  and  allowol  to  stay  for  xonu-  houn, 
fUt  of  the  urea  disappears.  But  ai  pri9>etil  thero  is  no  very  decided  proof 
Uiat  under  ordinary  cowlitiom  either  the  water  or  other  cooetituents  of  uriuo 
ar*  tu  auy  appreciable  extent  ahdurbed  by  the  bladder. 

Uttdcr  abnormal  conditions,  as  in  inflammation  or  irritation  of  tlie  bladder, 

the  urine  may  have  iiuderKone  nnirked  ohaogee  during  ila  fttay  in  the  blad- 

^tr.  (]i>e  of  toe  mudt  eomimm  being  a  change  of  some  »f  the  urea  into  auimo- 

Oiuni  ovbooate,  by  which  the  urine  also  l>eeome8  alkaline.    Under  Atmornml 

ctMidttkNU  alao,  Ute  mncu«  of  the  urine,  which  in  a  healthy  man  h  iiiHt},iiili- 

<lMit.  ibuugli  in  some  animal*,  fur  iii*tniicc  the  liorbi',  it  occura  in  con»dL-rable 

Quantity,  Is  largely  inrreiuol  during  the  utay  in  the  hlailder.     Since  there 

■Ue  to  man  no  goblet  ndU  in  the  vi^iiail  upilbcltum  lin  the  frog  they  are 

ftrewnt)  «r  mucou*  glan<l>  in  the  wall*  <>(  the  hlwlder.  tbi»  mucus  must  be 

tuppticd  by  an  aboormal  metabolism  of  the  ordinary  epithelial  cells. 

TitK  8tuih.t[jke  of  tiik  Skix. 

§  433.  The  skin,  like  a  muooua  membrane,  cnnsist*  of  an  epithelium  nat- 
iag  UlMjn  a  conaective-ti»ue  baais;  the  epithelium,  which  is  compoeeil  of 
taanr1ayeraofeelU,b  called  epiiUrmu  [F'\k.  lot^J,  the  eon ncct ire- ties ue  basis 
bralleil  ilermu,  or  eon'iim,  or  eutu  vera.  The  surlace  of  the  dermis  is  thrown 
Up  tuiu  a  number  of  elevations,  pipilUe,  which  ditfer  in  Hie,  form,  complexity 
and  arrangement  in  dilfereni  regions  of  the  bo<ly.  Souie  are  small,  more  or 
has  oonical  elevation*,  limpU  papiUit.  In  olliers,  n  broader  primary  eleva- 
Uon  la  divideil  at  its  summit  into  a  numtier  of  secondary  elevalioni;  Uteae 
ara  evM^iuid  papUliv,  In  mnny  regions  of  the  iikin.  oii  fur  examide  io  tJte 
of  the  oonds.  tltc  |>apilhe  are  arnuigcil  in  ridgea  separated  bj  ■hollow 


&52 


THE   KLIMlSATtOIf  OP  WA0TI!    I'RODOOTS. 


furrows.  Tlw  iur&oo  uf  tlw  Ekiii,  thai  is.  ilie  couUitir  uf  l>it>  cfiiil«rmb,  Jtm 
ixA  Mlow  tbe  pujiilUry  contuiir  of  tlie  dermb:  Uic  iwjiiltBry  tmcor4[ngtl 
nppL-nr  to  pltiiigp  luto  am)  be  cuveml  u]>  by  the  wore  eveti  p[>i(](>nnii.  tl 
6url»oci  of  wliicli,  huwi^ver,  U  niarkeil  by  Uie  ridgee  nnij  rurruWM  «|>»k(&  i 
above  u  nel)  u  by  bolder  creosee  and  folds. 


ina.  iM 


8 


•w 


-■'^X 


II.  lieait  lajw,  oeaMlnt  uf i*-Mi-l*I  hrnoy  *»)<■ ;  m,  tHnlkti'CM  be««y  nil* ;  •  (,  il* 

luol-lain ;  U.  raH taiKHoiMi or  Uiti-lvhuit  lu;vr.  (»n<iliiitiic or  j>.  pncklv-odlt. irienj  lowtttmiri 
elcmcitoil  Mill  A>niilnc  ■  aliiiil*  tlraluin  ilmf  Itie  nfiTlnlu  :  uvl  •jr.  airUuncnnnbuinn  of  tj 
haiw..KutIal<n)  llMMMimluvldiita.  ■,  |iarl  oT  ■  |>l*iiit  or  MrrwHIbralii  lh«  •iiivtll'i«t  lafw  I 
tlw sum  ifn.  Kniiii ibit  plEiua  Kiw  tulaoM  aeTFO^Urlla  nHTlwli>«<d  fmmtat  up  •wmni  i 
•iMtullum-osIb  of  (ba  Sliiliil(ttt*u  Ufc*.) 

Th«  Aurface  of  tli«  dermis  b  not  4le%'eloj>ed  iuta  •  diMluot  au'l  MijHinlil 
biiAi-iueta  iiiembnuM,  as  is  .10  itften  llic  vase  iu  u  iiiucou*  moinlinini.^ :  bm 
tbe  DtiHtt  Hiiiwrficial  porlioDs  of  ttu:  deniiU  th<:  t'i)»ii«ctin)  tiwif  nlntwi'  litl 
ornti  tibriltiuiimaiiilconaiswofaboiiiogenemnDiHtrix,  innbioh  iir<!  ini)»-iltlc 
<:0DikH?tivir-iiiuiie<^r|>iuK!le«aDd  cxtremtljr  fineoloKtivfibriw.  T)>i;>  KupiTticii 
jM>rtioii  of  the  (b'niiU,  whieli  in  m]iQCtallj  welM^vrlojioil  in  tlio  |iu)iiltit>.  servt 
Dwonlinjily  titu  jiurgHHiM  of  n  biuwawut  iiicmbntiic.  and  KliBr|>ly  ilclinf^  ll 
derini*  foiiii  the  nvrrlyin^  epidcnnia.  At  a  vi-ry  littU-  di«UUMM  fmni  ili« 
qiirli-nuin,  lihrillutioii  tiwki^  iiM  a|tpoanincc  tbe  biiridlce  of  fibrilln  ititorladiijj 
in  a  iielwurk  wliicli,  vcrjr  doac  tet  id  tbt  outer,  inof«  suiwrtidal  layer 
lii-iMiiiM  riMiiv  aod  ntiire  open  id  llie  iuiutr.  deeper  parts.  The  cunueciii 
ii<fui>  of  the  di'rmi*  thus  paaove  iDMmibly  ioto  ih«  eubcutaoeuiis  euiiiieL-tii 
ttwu<',  ID  wbivli  iliiok  iiilt^rwuven  bundles  of  61>riliie,  bearing  in  trausver 
iM.-oiii>»  a  reriaiii  nwiiibUiicx'  to  Kclioiit  of  loiidoD-buiidlea.  form  a  ton 
open  iwlwork,  tbe  Inrger  h|nioc«  of  which  nr«  fre^ueaily  occupied  by  101 


TUE  BTHl'OTl'RE    OF   TIIK   SEtN.  A53 

of  fnt  w\\*  of  ihc  «ul)cutnn<Mtiti  niltpon  tiMiie.  Elusiic  libm  are  very  abiiD- 
dnni  in  tlio  ()cmii)<  {»r»pcr,  Iwiii);  very  5ti«  iiiiniediaU'ly  iMDenth  llie  e|>i<tenniB 
nnil  Ws-'oniiii^  cu«rw.-r  in  the  (leu)>cr  [■t\r[«:  titey  xre  nreaeni  also,  tliou^b  to  a 
1m8  cxu-iii,  in  the  eubcutaueous  coDn«cuve  linue.  The  skin  aa  a  whole  is  a 
Tcrv  elofelic  structure. 

JiloodvMwU  ar«  very  abuudant,  formiD;;  cl<«e  set  ca|>illRry  nelirorks  and 
loop*  immediaiely  tiuder  ihe  epiilenuia.  mpei-ially  iu  lliif  p«pill»,  and  mure 
open  networks  el»enhere;  )>ul  uo  IiIuikI vessel  paasea  inio  llie  e{>iderniu. 
Lyniplialic  vwaeU  and  Iym)>)ialti.-  ca|iillaries  are  abumlniit  in  llie  dernita, 
beuiK  cuunecied  liere  ba  in  otlier  renpous  of  tbe  body  with  itnialkr  "  lyii>|»b* 
epaAX»." 

The  eonatderaliMn  of  tbe  uervea  of  tbe  skin  it  will  lie  lulvBntt^c(9»ll•  lu 
defer  until  we  come  lo  dm)  <*Uh  tb«  «kin  w  nti  orgNii  i)f  iwuw ;  f'>r  thuiigh 
■ome  of  lite  niCanowiA  ui^n'efibn;*  ar»Cl)l'rvHt  librai  diittnbuu-d  lo  the  bloMl* 
Towk,  aixl  prolwiblr  lo  tin;  ^wenl-glamlH  and  (iibcr  etr>li.'turni  nol  diiv«lly 
OOnnectMl  wilb  iIh'  M-ane  uf  lotK-h,  tiy  I'ur  the  j^n-iik-r  niiniWr  luv  alTurvDt 
fibnn  beginning  in  dutiuct  Uotilu  orgaiw,  or  oUwrwiM  acrvliig  as  Mwwry 
xlnictiirw. 

J  434.  TIm'  cpidn-nii*  mnnuu  of  two  |>«rU,  neparaloi)  bv  a  fairly  vbnrp 
line  of  ditiuirciiliim :  an  innor  wirt  Inyi'r.  the  Malpi);hiiin  liiyor.  or  *h\iluui 
MiUpighii.  aud  an  outer  harder  homy  Inycr,  or  rirtilmn  rorHrum.  TIh;  >'kin 
u  is  mil  known  varies  in  thicknen  in  difiiToni  n^inno  of  l\w  Imdy.  niid  ihe 
dilfcTroces  are  due  nlnioet  exclunvely  to  varimion^  in  iliv  thtcknoM  <>f  the 
horny  layer  nhicb.  tvt  over  tlie  lipe.  in»y  be  extremely  thin,  or  m  on  the 
hvcl,  excesMVely  thick;  compared  wilb  the  vnriittiunH  in  thicknct«  tit' the 
horny  layer,  the  varifllions  io  thickue»  of  tbe  Malpi^bian  layer  or  of  ihc 
dermis  may  be  disregarded. 

llic  line  of  demaratioo  between  (he  jMalpi^hian  and  horny  layers  follows 
tbe  contour  of  the  surface  of  the  skin.  ni>t  that  of  the  dermis,  the  |w»illM 
of  which  apjtenr  in  sec^ou»  as  if  imbedded  in  the  )lalpi>;hian  layer.  When 
the  «kin  after  death  is  macerated,  the  homy  layer  is  apt  to  |)eet  '>ff  from  tbe 
Malpi;{hian  layer  below,  which,  oriitiually  «oft  and  rcjidere^l  still  mfter  by 
the  macemiion.  tbeu  nppeara  as  a  layer  »f  slimy  li^ue  Mpread  out  between 
the  sidfA  of  and  covering  the  »nnimii«  of  tlte  papillte  of  the  (termio,  aome- 
what  after  the  laxhion  of  a  network ;  hence  this  layer  was  in  old  tiinee 
•pfiken  <tf  an  the  rrlr  muroinim. 

Tlte  lowennuM.  innernwMi  [Hirtion  of  the  Slalpighian  layer  reBlinjc  iipoti 
tlie  dermu.  coOHUt^  of  a  niu{;Ie  Inv'^r  of  e)oMK»ted.  «r  almiwt  cohiuinitr  cells 
placed  viTtii'ally.  that  is  n'ith  tht'ir  lung  axi.i  p^TjieDilicular  to  the  plain-  of 
the  ile.rmi;-.  Thin  layer,  which  pmcrvct  tlvc  original  ffuturtu  of  the  rpihlaHt 
of  llx'  iMiihryo.  an<l  which  niny  lie  followed  over  the  jiapillw  lU  welt  aa  alons 
the  intorvCDil^  valleyif.  proi^nts  n  charael<rri«tio  apMUnuioc  in  vcrttcttl 
M'cliims  of  ibe  skin.  Knch  cell,  which  it  ahmit  a«  large  m  h  tuiioDcyie, 
about  r2/>  by  6  m.  consisif  uf  a  fdlativcly  large  oval  nudeus  lying  lu  tho 
midot  of  a  voarsely  granular  cetl-sulwtanci^,  which  slain*  rewtily  with  tho 
ordinary  staining  reagents.  The  baf«  of  the  veil  abutting  on  the  ilermia 
ofiea  shows  fine  jiruocsses  interlocking  nith  oorresiiondiDg  prooeates  from 
tJie  dermis  ;  the  mU*  of  the  colls  arc  in  doM  contact,  but  merely  i»  oontaci, 
tlo  cement  substance  existing  between  thorn. 

The  nest  of  tbe  cells  of  the  Mulpighinn  layer,  much  like  oK'h  other,  are 
polvKi>nnl  or  irregularly  cubical  cells,  resembling  the  vertical  ci-lli!  juat 
sjiokeD  of  iu  8o  far  thai  each  consists  of  a  coarsely  granular  ccll-»iili>l»nc« 
iu  whidi  is  imbedded  a  relatively  large  nucleus:  this,  however,  is  ^phoricil 
not  ovaL  The  surface  of  each  cell  is  thrown  up  into  short  ridge*.  ra<liating 
somewhat  irregularly  from  the  centre  of  the  cell  and  prujediiig  at  lh«  Nc 


su 


TBS   ELllirirATIOy  or  ir^STB  VH0IirCT3. 


face  aD<)  et\g^,  so  «a  to  give  the  cell  som«w)i«t  lli«  appenntice  of  ha'tae 
aruied  wiili  a  ntiaiber  of  prickles.  Ueacc:  these  cells  are  oft«n  cmlM 
"  prickle  cells."  The  prickles  of  a  cell  do  not  iiilerluck  witb  tboee  of  iu 
ndghbord  but  touch  at  their  poiuls,  su  that  the  contact  of  ivro  adjaoent  c»ll* 
i>  uot  complete  but  carried  out  by  the  pointd  uf  tlie  prioklea  ouly.  miiiiitv 
ipacea  beiii^  Ii!ll  )>elwceii.  Hence  tbe  whnk-  Malpifchian  layer  b  traveraed 
by  n  liiiiyntilh  of  minute  paiwi^,  along  wliioh  lluill  cau  pasi  beiwceo  the 
tmicliiiig  iirirklnt. 

In  iIiirK  pkins,  ns  that  of  the  negro,  pifimrut  nnrtit^lcBi  alMuntl  in  the 
lower  Malpi^hiiui  cdla,  esj>ecially  in  the  vertical  layer.  In  Mich  caaei 
bruiichc<l  pigiiieril' cells,  connect! ve-tiHue  ci>rpUHi.-li»  loafM  with  pigmeat 
griiim)rfl,ar«to  bo  eocn  in  the  dermis  aIko;  and  occnsioiiiilly  !iniitar  branched 
cclU  may  be  seeo  in  the  epidermis  betneen  the  Malpighian  cells.  Leuco- 
cyte* also  not  infrequently  pan  out  of  the  dermis  and  irander  among  lb* 
celUof  the  Mslpighinn  layer. 

The  nuclei  not  only  of  ibe  vertical  but  also  of  the  other  polygonal  cdli 
may,  not  unrrftiueatly,  be  observed  in  various  etaeea  of  karynniituMi 
Throughout  life  the  cells  of  this  Malpighian  layer  of  the  skin  appear  tn  bi 
undergoing  in  u  111  plication  bv  division ;  the  increase  of  population  (bus  arir 
ing  is  Kept  down  by  the  cells  [wssing  upward  and  outward,  and  bocomiog 
tnosforitied  iuto  ibe  cells  of  the  huniy  layer. 

S  43fi.  The  line  of  deinarcutinn  between  the  Malpighian  layer  and  ibi 
horny  layer  is,  oa  we  bavc  waid,  »hnrp  iin<l  <listinct.  It  is  furnished  by  tm 
peculiar  «lr»ia  of  e«Il*,  more  conKpicuuuii  iu  sume  regions  uf  the  skiu  tboo 
10  otbeni.  The  lotverraoat,  inncrmimi  utratum  cuiwiHta  of  a  iin^le  layer  or  uf 
two  or  three  hiys  of  ocll«  which  arn  not  unlike  Malptghian  tells,  but  aie 
diR^tentiated  by  their  form,  being  extended  horizontally  to  a*  froiuenily  to 
■p^ir  fusiform  in  vertical  seclioas,  by  the  absence  of  ptickUv.  by  Ihtir 
■taming  very  deeply  with  certain  reagents,  such  ns  oaintc  acid,  and  esp*- 
ctnlly  by  their  cell  siibstance  being  crowded  with  large  discrete  granule*  uf 
a  peculiar  nature.     Hence  this  stratum  is  called  the  ilnttitm  gmnniwrun. 

The  stratum  above  this  cimM^is  of  one  or  two  or  even  more  layent  uf  cells, 
elongated  and  tiaiiened  horii'>ntallv,  the  cell  subataoce  of  which  is  homo- 
geneuua  and  iranapareut,  free  from  granules  and  not  staining  very  readily. 
In  the  middle  of  a  cell  may  freijtienily  be  seen  a  rod  shaped  nucleus  placed 
boriKimtally.  Thenc  dear  tniuspareiit  celU  form  a  tran«|wreai  team,  the 
tlr>itum  luel'linn,  between  tbe  stratum  grauulo^um  and  Mal|>tf;hiau  layer 
below  aud  the  horny  layer  above. 

S  436.  The  horny  layer,  wbicb  is  at  we  have  saiil  of  variable  Iwt  nearly 
nlwavH  of  considerable'  thicknfev,  in  formed  of  a  number  of  layers  of  cells 
whicn,  differentiated  already  in  the  lowtsi  luyent,  have  that  diffnrentialioa 
ooniplctcit  us  theco  pnsa  unwiinl.  The  upper,  outer  portion  of  this  bomj' 
layer  is  Goniinuallv  being  shed  or  rubbed  on  in  the  form  of  Hake*  of  vari- 
able si  w.  Each  Duke  upon  examination,  as  for  instance  after  diaMciaiion 
by  maceration  or  with  the  help  of  aikalics.  \*  found  to  be  composed  of  tie* 
meuts  wliich  can  no  longer  be  recogiiij^l  n*  cells,  and  which  nmy  be  spoken 
uf  as  »ca1«M.  Kucli  scale  is  a  tlnttcned  mii««  or  plate  in  which  no  nucleus 
can  l>e  seen,  aud  which  oonsiata  not  of  the  proleidn  and  other  couslituents  of 
ortlinary  cell  subiiiance  (§29),  but  almost  exclusively  of  a  ninterial  called 
trnitin'  TbiH  ii  a  body,  the  exact  nature  of  which  has  not  vet  been  clearly 
mmie  out,  hut  which  hits  the  general  percentage  composition  of  proteids. 
from  which  it  i'  a  derivnie.  with  the  exception  that  it  contains  a  considerable 
ounnlily  of  sulphur  t,the  kertitin  of  hair  contains  as  much  as -^  per  cenL); 
this  fulphiir  npp<-an>  to  bt;  soini^whnt  lonselv  attached  to  the  other  eleraeai* 
of  the  ki.-nitin  *incc  it  may  be  removed  by  boiling  uiih  alkaliea. 


THE   3TKCCTt*BB  OT  TEZ  81CIIT. 


Thr  liiw«rin<i*t   |>'>rlii>iH  of  the  liaroy   Inyer  are  composed  of  elerupnia 

wkirb  may  uilt  l>e  recuKiiiied  a>  cells,  iotuoiiicb  na  each  contuina  &  nucleus, 

Ibnuch  ilii*  ii  obvioiiiiy  uDdersoiag  ohkqge  Kud  on  the  way  U>  diaappesr. 

(la^h  odl  U,  hnwever,  flaiwoea  and  plate-like. 

aoil   iu  •utwiwiM-  nlrcudy  oodubU    largely  of  [Fn-H*. 

lwr«Ua.     lu  jMuwiii^  iifiwttrd  fntm  the  lowtr  to 

tbs  man  BUiwrficial    luirU  of  thu  horny   luvrr 

•ueb  ui  iBiiM-rfrct  <x-li  loan  Ju  niicleiiii.  hihI  "htt- 

MBMB  thr  whulty  kvnUiiiMi*  plnt« Juitt  deacnlxrd. 

The  wboU  horny  layer  eounivta  of  strnta  of  cl»- 

n«iit«,  homy  to  b«rin  vith,  but  lH.>cDaiinc  mon 

nnpktely  to  in   the  iipiier  |iart».     Bekiw.  in 

(untttct   nith   the  inowt  Malpighinn  Ittyer,  thft 

komy  layer  u  moisl  but  the  HUiwriicinl  pnrUi  b«- 
^MM  dry  hy  evaponition  ;  aiut  hptv  the  strata 
HHlBmitaMtC  Vrom  each  other,  the  otitcr  oiiet,  08 
HKhave  Hid.  being  t^hed  in  the  form  of  flakt*, 

which  Been  in  the  dry  condition  under  the  micro- 
•c*>pe  have  often  the  appearauco  of  irregular 

Sbrei. 

The  karroniitosii  seen  in  the  cells  of  the  Mai- 

pighiao  layer,  not  only  iu  iJiose  of  the  vertical 

larer  but  in  tlte  otbcre  at  irell.  »how,  as  we  have 

wkM,  that   lli<!W  miiltttily  by  diviHion  ;  ne  have 

BO  triilanc*  of  loulliplicaliim  tekiii|f  plac^  elw- 

wbcn  in  the  epidcnniii.     Thti  more  .inpi'rficia] 

CtUa  of  the  Malpifjhian  layer,  thru»t  upnurit  by 

the  DCW  corners,  are  trniKfurmcl  into  the  cclle  of 

lie  atnUum  gniDuloaum ;  and  although  we  do 

tot  ■■  yet  filUy  UDderetand  the  exact  nature  of 

ihe    trvunformalion  we   may  conclude  that  the 

pvcultar  (granules  of  theec  cclU  are  concerned  io 

the  manufacture  of  kenilin.  Chtinf;cd  by  the 
cuosumplioii  of  their  (-ranulea  in  thi»  mauufao- 
ture,  the  cells  of  the  stratum  j^anulosum  become 
AraS  tlic  celU  of  the  Biralum  luetcum,  and  ilien 
Ike  raUi  of  Ibe  diMinvtIv  boniy  layer,  pushed 
ti|>«ranl  through  wliieh  bv  the  new  fonnaiiona 
^continually  suooeediiig  below  them,  they  \mim  to 
Xbv  varfaoc  and  are  eventuallr  nbed. 

$4S7.  TlUfuvif-y/""'/'.  A  tineat-KlamI,  like 
'«cb«r  ehmdi,  oooMUof  Btecretinz  iHiniun  and 
«  coBd««tliw  portion  [Pig.  1591.    The  secreting 

Ennion  i'  a  KHtg  lubulnr  alveofn;!  cuilet)  up  in  a 
nut  and  placed  in  (he  >>ntK-ntatieoiii<  cnnncclive 
tiMue  at  suaie  diatance  fr»m  the  epiitermi*.  Gen- 
erally Ifat  gland  i»  forme<)  of  onf  mch  tubule 
otUy,  but  soiDctiinefl  two  inbuU^  nniic  into  a 
duct.  The  duct  beginnine  in  the  knot, 
eonvobilions  of  trhich  it  shara,  runs  a 
irhat  navy  but  oihermise  straiftht  courve  vertically  toirard  the  aorfooe 
of  [he  skin  on  to  which  its  lumen  opens. 

Through  the  epidermis  the  duct  ia  nothing  more  than  a  tubular  pasaage 
txtmraled  out  of  the  epidermis  with  a  remarkable  <'»rksorew  course,  the 
turn*  of  the  screw  becoming  more  open  and  tlie  canal  wider  in  the  upper 


tn:tinMirtMiN.«<ii.un>  ramt  ras 
fxLM  or  tiu  Baud.  lUagnUWd 
Wdlamoien.) 

1. 1,  mnloncd  iaM»,  etrnipotnt 
llw  (Und,  and  odIUiv  la  Ivo 
axpmlonr  diMi ;  1.  It,  irlileli  UOM* 
Loio  oils  finl  Mill  itet  pwa^- 
r*(is  ili«  «|ililDrtul«  Hi  f.  andoptoi 
lu  iiirDtc*  at  i  :  Ih*  ■laiiit  la  an. 
■willed  In  Ikt-Tciricka,  utilcli  an 


THB    ELIHINATIOK   Of  WASTC    PKUnrffTfl. 

pnR  lu  ii  it])pro«chM  the  aurfiice.  lu  llic  Mulpi^fhUii  layer  Ui«  cell-  k.nUr 
ing  i>ii  thi.'  pttMigv  are  lI»tt«De<t  and  iiu-liiinJ  il»wtivtnnl  »>t  lu  to  ntl'ini  i 
more  or  lc*i  dcfiiiUc  lining ;  tli«rv  i«  it  fiiniliir  arrniijriini-nt  but  ooi  »'  "r  > 
well  in   lli«  c<fri)L-uue  layer.     K«iu;hing  tbo  il«rmi».  iii  m   valley  b«i«na 

ERjtiliii',  llifl  paiia«f[e  beoMiiw  a  ngulnr  duct,  witli  oti  independent  epitW 
mil  "f  iUuwii,  »  dtslinct  bsaetBent  nMnitintDu  cHilinuous  wiih  the  upfar 
Hirfiiw  uf  tJi«  <k-rRii«,  and  au  outer  cont  uf  ooiioet-tire  tissue  elreiiErlliracit, 
in  Our  osuw  of  mtti^  of  tbe  Isrirer  f;land«.  «ich  as  thoae  of  tite  njciTU,  «ilb 
jilain  muHiilnr  tibrea.  Tbe  «{>iilHrliiiiti  cunaista  of  iwo  or  ttirvta  Inygn  <( 
Mnmli  roiind«(l  cellB.  ench  irttli  a  relntirdy  large  but  aheoluldy  anmll  oiiclni^ 
gonendly  ettiiuiiti;  <let!jily.  Tlie  celU  leave  a  uarrow  tubular  tbivad-lBw 
TuiDMi  vrbich  k  lined  wilh  n  vt-ry  I'liaroeierislii--  diMiuit  ciiliole. 

TIh^  ilui^t  cuDiitiuM  u<  |HMWH>  iliau'  diarai-i(.'r§  after  it  haa  entered  tlM  knwt 
niid  \w(^n  t«  |>iir!>iM!  a  tvriMwl  <:»ur«i!.  but  soiiu  cbaiii;<^  tiuddculv  iuui  Uri^d 
Mcretiui;  lubule.  ThiK  tiiiiy  i>f  di«tiii|{tiiHh<.^l  fruoi  tbi;  duct  by  Ixmi);  wiiWtjH 
Wld  by  beiiifi;  liuL--i  by  s  xiuglu  layer  <>f  cubical  nr  oiiiiiuuHr  chIIa  lai^ 
tluin  tlKise  uf  till'  durt,  IxTiiriDg  far^ger  nucl«i.  and  twhavin^  <liflbre&Uf 
tovaixl  variouN  otaining  reagsat*.  The  himttn  though  fairly  distinct  U  Dot 
liued  by  nor  trutirle  im  in  thu  duct.  Lying  botirven  tlnj  b««eR)«nt  taeni- 
biane  and  iIh^  i.i|>i(hcii«l  mll».  nr  ratbcr  iinbodud  in  the  baM'ment  tu«iDl>raut 
ore  seen  a  nundx-r  of  jitaiu  muscular  fibres  disposed  longitudinal ly  or  io  id 
elou){atMl  spiral,  and  o)l(?n  lorming  a  diatinct  cont  bonnUh  t)i«  epilbelium. 

Ail  in  the  case  of  other  ^jlaods,  we  are  uimble  to  malc«  niiy  stat«iu«tiC 
to  the  nork  carried  on  by  ihe  eirilheliuDt  lining  the  duct,  but  we  may  p 
ably  iissiitne  that  the  sweat  is  niainly  secreted  by  tlw  larger  cells  of 
terminal  roiled  part  of  the  lubule.     Tlieee  celU,  therefore,  like  other 
cells,  are  probably  "  loaded"  and  discharged ;"  but  as  yet  uo  marked  si 
lural  changes  in  ibe  cells  cormponding  to  these  phnsea  hare  lioeu  mi 
torilr  ascertained,  though  nf^cr  tbe  admin islralJoii  of  pilocarpine, 
causes  sireating,  tbi-  im-IIh  of  glands  hardened  in  alcohol  ^laiii  uii>ri;> 
Ihan  iifiual  with  <-arniiiii:.     It  miiiit  he  remembered,  boirever,  that  the  r 
couIaioK   tiKriiially  in'ilhi-r   i]iut-ii:>  nor  pnilcid  fiubdiance^,  nud   u'o  sh>»i 
llierefiirc.  not  csiit'i-t  t'l  oW-rvi'  "  granulcfi "  in  the  evils. 

The  ix'culiarly  |>laced  munciilsr  lilirw>  liavc  been  stipuoaed.  b^  Ihcir 
traction,  to  assiH  in  the  flow  of  sweat  along  the  tubule.     In  certain  cutAneai 
gluiida  of  Ihe  fi\>g,  uf  a  relatively  simple  nature,  there  is  cvidt-ncc  that 
secn'lioR  is  i-jix-led  from  the  compamlively  larm  lumen  by  Uie  contnictii 
of  plain  mii#cular  fibres  in  the  wall  of  the  jjlaiid.  or  by  a  oouinirlioii  of 
wall  ils>.']f.  which  is  contractile  without  being  dislinctlv  diflrrt-n tinted 
mu-cular  tissue.     \ad  this  rather  supports  the  above  vU« ;  but  the  tnat( 
is  at  prmeni  by  no  menus  clear. 

The  coil  of  a  sweal-glnnd  la  well  supplied  with  bloodvewete  in  the  form  i 
capillary  naworka,  and  n«Tv««  have  Iwen  traced  [o  the  tub«a ;  but  tbe  exa 
manner  iu  which  lliete  end  U  nut  ns  vei  known. 

Though  pruHmi  in  all  regioDs  of  tfie  skiu  (uf  man),  tbe  sweut-qlands 
unequally  di>iribiiied.  Iicinji;  PMra  abundaul  in  some  rcgiMis,  such  as 
palinsof  the  hiind.  than  in  ulhetK     In  the  axilla  are  )•  lands  of  very  In 
sixe,  and  in  tlicse  the  ducu  piMM«  distincllv  musoular  ciiMts. 

i  438.  Seh/wMta  gieiHiU.     [Fig.  160.]     Tbtsw  are  appvudaKeii  of  tlio  ball 
A  Iinir  io  H  devcliipnicnt.  in  the  form  of  a  eylindt-r,  of  a  cap  of  come 
epidermii'  xiinnouoting  a  papilla  of  the  dermis  nmk  to  the  liottum  of  a  (u 
lar  pit,  or  involution  of  the  skin,  called  a  hair-folliole.     In  llie  unp«r ' 
of  (he  iiair- follicle  the  walls  cunsist  uf  oi\linary  :>kin  wilh   all   it«   i 
dermie,   Malpighian  layer  and  corneous  layer,  the  latter  il>  usual  <>[ 
sidemhle  llii<-kuees.     At  some  little  distance  from  the  ouHilh  of  the  foUu 


\ 


tl»e  c»ra«(Kis  layer  siiildeiilr  c««m»,  nw)  in  the  follic)<?  bclovt  tlm  iiv  I'pU 
dermis  is  repivseniei)  ))r  the  M)i)i>igliuiii  layer,  uow  called  ibv  oiiior  root- 
sheaiti.  and   two  tayen  of  |>e«uliar  wWa, 
fariDiujf  Ihe  inii«r  r<H)i-sl)»ith.  of  wbich  tlie  IPto,  tio. 

otiier  Ih  cnllei)  Ucutes  aud  tin-  iii(i«r  Hux- 
ley'a  layer;  lliewe  mav.  |ierhii|#,  he  r»n> 
iiidiiri-d    ua    cornwpi'iiiiin^   !■>  ibc  xinitiim 

SruniiliMumaDd  luddiim  rti<;)ootivelr.  The 
■.•rmi"  of  lti<!  vail  of  Ihv  fnlliclc  ix  at  tlic 
Mine  tiin«  <kvi;l"i>«l  into  aii  imtcr  layer 
with  txiadlw  of  conni-dive  liwue  diijKiwd 
chiefly  loiigitailinMlly,  »i)d  nn  inner  layer  of 
pec-iiliar  Dature,  thp  arr«n)i:cnient  iif  which 
IS  tmnsvcrw-.  iind  nhtoh  at  lenst  etimulnio!, 
if  it  fMilly  ittr  not.  ti  nniseiilar  transverw 
coat,  Betvr«;n  thi*  dermis  of  the  follicle 
and  the  outer  rool-«hcnlh  or  ,^la]I)if;hiH^ 
layer  is  a  very  contpieuous  deJiniie  hyaline 
baseineni  ineinbmne,  so  tliick  that  it  pre- 
M-nu  a  very  easily  recogniiied  double  con- 
tour. 

At  the  bottom  of  the  follicle  the  dennU 
of  the  wall  of  the  folliele  is  c»utinuou>i  with 

the  Hibbtance  of  the  (dermic)  |iatiilla,  while 

the  outer  roo4-sheath  or  Mnl|ti};hiaii  laver,      •^mmnf. 

which  here  be««meH  extremely  thin  iintf  re-      ^WKj"  Vi 

duool  lo  one  or  (wo  layers,  i«  n-Hceleil  over 

the  ]in|iilln,  and  there  cxjMiidii  strain  into  ti 

niHiH  of  mils  whieli  like  the  cclU  of  the 

Mal)Mghiaii   hiyi-r  in   iJio  rent  of  the  «lcin 

multiply,  and  by  their  nudtijilicntion  give 

ri«-  I'l  the  ciirneriuii  tioilv  of  the  hitir.     It  it 

Hii<I    ihnt   ill   llioHe    l)iiir»   uhieh    ji'wiii*   u 

tiiedulU  the   v>Tticiilly  •liKjiutrcd   t'lnirnio"! 

C«1U  of  tiMi    Mitlpighian    layer  are  at  the 

actual    •nmmii   of  the   pupilln   roiiliniiei) 

upward  ill  the  axis  of  the  hair,  us  the 

raediilla. 

The  layer  of  Henle,  following  the  >ltt1- 
linn  layer  or  outer  Toot-she«th  on  which 

it    mts,   is  similarly    rellected    and    forms 

over  (he  hair  a  sio);le  layer  of  Hot  trans- 

jiareni    imbricated    scaler    known    as    the 

cuticle  of  the  hair.    Huxley's  layer,  simi- 
larly  rellerled,   forma  a  similar    layer  of 

nmilar  w-nhti,  but  thin  \»  connidercil  as  be-  /  ^' 

longing  t<>  the  mot-Hhenth,  and  i»  called  the 

ciiltele  i>f  llw  riMit-itht-fltb. 

JiiM  where  the  o<ii:iiv>iis  laver  ahruptlr 

leavesoff  in  thr  uugicr  part  of  ihtr  hair  fol- 
licle, a  Bcbnccoui  gland  o}H'Ms  into  the  cavity 

of  the    follicle  nn  enrh   side   of    the    hair. 

Each  k,'l"i"i  coiiM^t"  of  n  iiboTt  rather  wide 

duct  which  ilividfls  into  a  clii«tcr  of  some- 
what  Hask-sliaped  nlveuli.    The  tMsontent 

mrmbmne,  Ixiili  to  llie  alvmli  niM)  in  llie 


\ 


pighi 


llttN-rOUICI-C  IM  ljU)HllirNKjtL 

smiiBi 

<^  nuNith  of  liilUvIc ;  6,  nod  ;  r.  diilb  - 
il.r.dcrnuo  coal:/,  nutrr  ront-ilintli : 
9, Innrrml-iliailk :  A,  blr:  t.  Ri  m»- 
diiUa;  (,  tuilr-lin»t>:  *i.ailt|iMeliHln; 
a.  twlrmawlr,  v,  |ii;iillK  •<!  *Uui  f, 
Itttfltt  ufUalr:  t,  ruiv  ii><i<>i>"ui,  tMi- 
Unoniw  tttib  auloi  Fwri'fbotlb :  1^ 
bomrlitlvt:  I,  "itBdjinwBliiBiJ.] 


TOE    KLIUINATIO.V    or   WASTE    I'BOUt'CTS. 


duct.  i«  liiMil  will)  n  Injrr  »r  rnilier  aniall  ctibit-iil  n\U  r<iMtimi>>iiB  wiiL  <V 
layer  vf  |><-rji<'ii<licuUrty  <lL>piw<l  oelbwhk-h  I'onit  titr  iniUTiniBi  Invvr  i 
tho  oiilor  r>jut-ahciUh  M  of  thv  AtnliML'ltiiui  lavvr  uf  the  akin  geoenll;. 
This  layrr  of  colU  IfAvm  n  wide  liinM;n  Ituth  in  tlie  Blvt^iti  iimt  in  llw  duel; 
this  lumeti.  h'lircvcr,  is  occiijiicd  ixit  ns  in  other  glands  with  fluid,  but  nitli 
cells.  Botli  alri-nii  mid  duct,  iu  fact,  nn'  fillvd  with  n>imde<j  ur  pidypuul 
OtIIr  which  ninv  be  regarded  as  mixlilii-d  cvIIg  of  l\w  Mnlpi^binii  Intir, 
The  whole  gland,  indeed^  is  a  sidid  diverticulum  of  the  M»liii);liiaD  layvr. 

In  the  alveoli  the  cells  next  U>  the  layer  of  cells  ii»nieJiiii«ly  Wainf,  iht 
baaenieni  menibnine.  though  larger  thau  theee,  reaemble  iheiu  iu  du  far  thai 
each  oonsisls  of  ordinary  cell  eubslaDce  siirrMiuding  a  nucleus  nt  aribmn 
character.  Tlie  more  central  cells  are  ditler«oi;  their  cell  inilMbin^  •■ 
undemiiDg  chan^,  uumerous  granules  or  droplets,  nn>e  of  ihem  <ih^ 
of  a  (attv  nature,  make  tbdr  appearauce  iii  them,  and  llie  niicln  mv  '^r- 
cuming  «lirunk  and  altered.  Th«  cells  are  manufiictunng  fatty  and  nthrr 
bodien  and  depositinK  the  products  in  tlwir  own  Mbstance,  which,  howni-r, 
Ik  hot  heiii;;  rt-ui-wed,  but  la  dyiiix-  Thee«  chantceA  are  still  awn-  oliirioU'  is 
ihi'  cell*  Iving  wilhiu  thi-  duct;  the  cells  as  indicated  by  the  breaking  up  "I 
t)ie  uui-Ivi  un-  di.'«d.  and  the  whole  of  the  cell  subataucl^  ha*  b^WD  tran*- 
lom>e<)  intii  the  niuierial  I'lin^iiituliuK  the  secrMitm  of  the  eland,  called 
M^m,  which  in  <liiicharg«.i]  on  to  the  surface  uf  the  skin  tliri>ugli  the  nioatk 
of  the  hair  follii^li'. 

Iu  theiw  M-biicnous  glaiidi  secretions,  if  wo  may  continue  (o  tue  the  ^nui, 
taktt  place  al1cr  ii  fashion  ditliMreiit  IVcim  tjiat  which  we  hnvv  bitlierto 
Studied.  In  an  nnlitinry  ghuxl  llie  c«IU  lining  tliir  walls  of  the  nirmli 
maiiu&clurc  niiitrrial  which  they  discharge  from  ihvmsolves  into  the  lumes 
to  form  the  secretion,  iheir  own  milMlance  being  at  Um  sante  time  reiwotd. 
BO  tJiat  the  same  cell  may  conliiiue  Co  ninuuliKlDre  and  diachar;^  the  aeciv 
ttoti  for  a  very  prulong«d  period  without  beinir  itself  destroyed.  In  • 
eebaceouB  gland  tlie  work  of  the  cells  immediately  lining  the  nail  i>f  aa 
alveolus  appears  limited  to  the  task  of  increasing  by  multipttcatiim.  Ofthe 
new  cells  inus  fanned,  while  some  remain  to  continue  the  lininfc  and  (o  carry 
on  the  work  of  iheir  predecessors,  the  rest  thrust  toward  the  centre  of  ttw 
alveolus  are  bodily  transformed  into  ibe  material  of  the  secrelKm,  and  duriaj 
llie  transformation  are  pushed  out  through  the  duct  by  the  geoerntian  « 
new  cells  behind  them.  The  secretion  of  sehuni,  iu  fact,  ia  a  nuKlificallu 
of  the  iinrtit-ular  kind  uf  secretion  taking  place  all  over  the  skin,  am]  siMtkta 
>if  iu>  nhtNlilbg  of  the  skin.  It  ia  ehielly  the  chemical  tranafiirmatioii  wbich 
u  diDVnnt  in  ihe  two  cases.  Iu  the  skin  ;;enerally  tJie  prolopUsitiic  cell 
KuMaiiie  of  Ihe  Matpi^hian  eellB  is  transformed  into  keraiiii :  in  lh«  s^w- 
CI.MUS  glands  it  is  tnuMformed  iiito  llie  fatty  and  other  MiuHtituentt  of  tke 
sebum.  8<>m«,  |>erhaps,  may  hesitate  to  apply  Ibe  word  spcreiion  to  aucb  a 
proceas  aa  thia ;  but,  as  we  shall  see  later  un.  tiie  fonuaiion  of  milk,  whidi 
(vriainty  deaervca  to  be  called  a  seerction,  is  a  procAw  intcrmcdjale  betweea 
the  svcrelioii  of  saliva  and  gi»trie  juicn  and  tlw  funnation  of  sebum. 

The  sn-callc<l  "  ccruminous  "  glands  of  the  cxtcnuil  menUis  of  the  e*r  an 
ewentially  sweat-gtaniln.  They  are  wrongly  namoil,  since  the  fatty  material 
eiM>keii  "t"  ii"  ■■  wax  "  of  the  ear  in  «ecn^t«d  not  by  thcni  but  by  the  aebaneooi 

filiiud'   III     rijiiig  U>  the  hain>  of  tlic  meatus,  or  by  the  seneral  epidi^rniic 
tuing.     1  Ik-  c>.Tuniinous  glands  appear  at  moat  to  supply  Que  pigment  whioli 
colon  the  "wax." 

The  Meibomian  glands  of  the  eyelids,  oil  the  other  hand,  are  eawniialW 
the  sebnceont  glaiKis  of  the  eyelashc«,  the  giflude  of  Muhl  being  In  turu 
sweat-glands. 


ST   OP    l-KBSrtHATIoS. 


5.VU 


TiiK  Naturr  aki>  Auount  or  pRUfvittAiiox. 

t  438.  Th«  i|UiiDlitT  of  iii«it«r  which  l«nvM  Uie  human  b<Klf  br  war  of 
iW  akia  la  vmty  cuiuid«nibli.-.  Thus  it  hus  been  ofllimaloi  thai  while  OjO 
(nMBie  |MBaM  iiwkv  throueh  the  lungs  per  minute.  a§  much  as  0.8  Krnmme 
faHr*throuKhth««Kiii.  llwainoimt,  hnwei-er,  vari«»oxireniely  :  h\>m  beeii 
<slcfil«l«(l.  Ironi  ilnin  ^incd  by  enclueiii^  the  arm  iu  a  ciXHiichoiio  ba;;,  thai 
ik  UAml  uiinuni  of  pen  ignition  fmm  i\w  vrbol«  bwly  ii)  tweuiy-f'Xir  h'ttir* 
■i|^t  nuigv  fruni  'i  to  '20  kiloa;  I>ui  micIi  ■  mode  uTcalculaiioD  it  obvjauily 
9fM  lo  niaoT  flwircM  of  error. 

Of  ilie  whole  amount  tbiu  discharged  part  paaMe  awar  at  onc«  lu  vnury 

Ta(Mtr  mix(iJ  with  volatile  mattara,  while  jnn  niay  ivinaio  fur  a  tiuto  a<a 

fluid  oa  (be  nkiu  ;  the  former  is  IVequeiilly  >|H)keu  of  ta  i-uteiuiihlf.  the  latter 

•■  m^nri&lf,  jienpiratioD  or  &weal.     The  pr<>t><irti(iu  of  the  iiiMiiMhli.'  to  ihd 

•riu>ibt«  |>«nijiiralioa  will  depend  ou  Ihe  ra))idtty<if  theMcn'tion  in  roleieiicc 

to  the  dryocaa,  tfiroperaiure,  and  aiuuunt  uf  iiiuviMueiii  of  the  xurr>fut)dini; 

mttxttmfiben.    Thua,  tapptmae  the  rale  of  sccreiiou  to  remaia  consUmu  the 

•lri«r  ami  hMur  the  air.  and  the  more  rapidly  the  nratn  of  air  in  contact 

■with  th«  biMir  are  rvnencd,  the  ttreater  it  the  amount  of  tCiuible  perapiraiion 

-wliirh   i»  1>T  ovB(H<rnliou  ocHivertei]  iiiIj)  the  iowiuibk  oondilion ;  and  con- 

TTviwIy  wh«o  till-  nir  iii  cool,  moint,  aud  rtaguant,  a  larga  amwint  of  the  tulal 

Mtvniratioii  may  roniaiu  on  the  Mn  tu  aemable  awoaL     ^finec,  a»  the  name 

impUM.  «a  are  ourtelvo  awarv  »f  the  «rn.-<ilile  pcnpiration  onlv.  tc  mar  and 

fteqoMHlj  do«a  happen  that  wc  xeciu  m  otitvclvra  to  bo  penfnrinc  largely, 

wbaa  in  rMdity  it  is  nut  »o  inu<:h  the  l'>l«l  perspiration  which  b  bein)[  in- 

cTcaatd  aa  the  relative  propnrtion  of  the  sensible  pcnpiration.    The  rate  of 

aecrelioa  may,  bowerer,  be  *o  much  increased  that  no  amount  of  drynei*  or 

bntt.  or  rooveoMBt  of  the  atniqephvrc.  is  sulBcient  to  carry  out  the  neoeuarr 

«T«piiniii»ii,  aod  thus  the  aoiiaibto  ]>cr«piratioa  may  becooie  abiindaiit  In  a 

but.  dry  air.     .\nd  praciically  this  is  the  usual  occurrence,  since  c«rtAi»ty 

a  hub  tero|ieratiin'  cotvluces.  as  we  ^lall  point  out  preifrnily,  to  an  incrvaM 

of  tbm  accnitiou,  and  it  u  puwible  that  mere  drvueas  of  tbe  air  hn«  a  similar 

tdbec 

Thr  anioanl  of  jwrtpiratioii  given  ulT  u  iilRtetcd  not  only  bv  tbe  coivtiliou 

af  thr  Biuinnphprv.  but  nb"  by  tbe  cireiim>taue«a  of  lhe'lHx)y.     Thua  it  is 

'ii6uenvcl  l>v  the  nature  and  (juantity  of  food  eaten,  bv  the  amount  of  fluid 

^ruiik,  by  tin-  chunicler  of  exen-ite  talcvn.  by  the  relative  activity  of  the 

uiber  «xi-ratiog  ur^^nN,  more  jinrlinilarly  of  the  kidney,  by  mental  condi- 

am)  the  like.    VariiilitM)*  ninv  al.->i>  Im-  induced  by  drugs  and  br  diaenaed 

How  ihcw  varMHis  iiiduvntm  produci*  tbdr  clfecU  we  aball  study 

The  fluid  perspiration,  or  'wi-al,  when  eollectcd,  l<  found  to  be  a  clear. 
^aloHans  lluid  of  a  distinctly  »nll  lasle,  with  a  xlrong  and  diMinctire  oilor 
^rmryinic  according  to  the  part  of  the  body  fr>3m  which  it  is  taken.  Besides 
aocidootal  e|>idermic  scales,  it  contains  no  sinietural  elements. 

Sweat,  as  a  whole,  is  fumiubcd  wrtly  by  the  sweat-glands  and  lurtly  by 
tbe  aebaceotts  glands,  for,  ns  we  sfinll  mc.  tlte  small  nmonnl  which  simply 
UMiaudca  through  the  epidermis,  a{Hirt  from  the  glands,  may  he  oeglei-tvi). 
linw,  tbe  secretion*  from  lh«c  two  kinds  of  glsii^ls  dider  niilely  iu  nature, 
and  tbi!  characters  of  the  sweat,  as  a  whole,  will  vary  according  to  tbe  rela- 
tire  ptoportioa  of  the  two  kinds  of  secretion.  The  secretion  of  the  sebeoooiH 
riuM*  appears  to  be  fairly  constant,  the  lart;er  varialiuiu  of  the  total  sweat 
depmdinit  chiefly  »u  tbe  vaM,-tns  activity  of  tlie  sweat -Klandn.  Hence,  wlten 
•Met  is  scanty,  tli<!  ouniititucutd  of  tbe  sebum  iiiflueim-  lar^^Iy  the  cluirac- 


560  THK    ELIMIXATIOX    OF    WASTE    PBODUCTS. 

• 

ten)  of  the  sweat ;  when,  on  the  coDtrary,  the  sweat  is  verv  abundant,  tbnt 
may  be  disregarded,  and  the  sweat  may  be  considered  as  the  product  ot  tk 
gweat-glande. 

We  are  not  able  at  present  to  make  a  complete  statemeot  as  to  irhtt 
bodies  occur  exclusively  in  the  sebum  and  what  in  the  secretion  of  tbennat 
glands.  The  former  consists  very  lar^ly  of  fats  and  fatty  acids,  and  appcan 
to  contain  some  form  or  forma  of  proteids ;  but  we  have  reason  to  tkinV  t^ 
the  sweat-glands  secrete  in  small  quantity  some  forms  of  ^t,  and  espedtlly 
volatile  fatty  acids. 

When  sweat  is  scanty,  the  reaction  b  generally  add,  but  when  abundaa^ 
is  alkaline;  and  when  a  portion  of  the  skin  is  well  washed  the  sweat  whick 
u  collected  immediately  afterward  is  usually  alkaline.  From  this  we  vmj 
infer  that  the  secretion  of  the  sweat-glands  is  naturally  alkaline,  but  thtf 
when  mixed  sweat  is  acid ;  the  acidity  due  to  &tty  (or  other)  acida  of  da 
sebum.  In  the  horse,  which  is  ungular  among  hair-covered  animalB  for  iti 
frequent  profuse  sweating,  the  sweat  is  said  to  be  always  acid  and  to  omitaia 
a  considerable  <|uantity  uf  some  form  of  proteid.  These  features  are  proba- 
bly due  to  the  large  admixture  of  sebum  from  the  numerous  sebaceoua  glandi 
connected  with  the  hairs. 

Taking  ordinary  sweat,  such  ns  may  be  obtained  by  encloeing  the  arm  ii 
a  bag,  we  may  sav  that  in  man  the  average  amount  of  solids  ia  from  1  to  3 
per  cent.,  of  which  about  two-thirds  consist  of  organic  substances.  Tbe  diid 
normal  constituents  are:  (1)  Sodium  chloride,  with  small  quantities  of-othcr 
inorganic  salts.  (2)  Various  acids  of  the  fatty  series,  such  as  formic,  acetic; 
butyric,  with  probably  propionic,  caproic,  and  caprylic.  The  presence  rf 
these  latter  is  inferred  from  the  odor ;  it  is  probable  that  many  vaTiOM 
volatile  acids  are  present  in  small  quantities.  Lactic  acid,  which  has  ben 
reckoned  as  a  iinrmal  constituent,  is  stated  not  to  be  present  in  heahh 
(3)  Neutral  i&ls  and  cholesterin  ;  these  have  been  detectM  even  in  plaeci, 
such  as  the  piilni.s  of  the  hand,  where  ^baceou^^  glands  are  present.  (4)  ^m 
evidence  goes  to  hIuiw  that  neither  urea  nor  any  ammonia  compound  exvtt 
ID  the  normal  secretion  to  any  extent,  though  some  ol>servers  nave  fbunda 
considerable  quantity  of  urea  (calculatetl  at  10  grms.  in  the  twenty-four 
hours  for  the  whole  bmly).  Apparently  some  small  amount  of  nitn^en 
leaves  the  body  the  skin,  as  a  whole,  but  this  is  probably  supplied  fay  tbs 
sebuiu  or  by  the  epiderinis. 

In  various  forms  of  (iiBefl(>e  tbe  Hwcat  has  been  found  to  contain,  sometima 
in  consiilerHblc  quantities,  blood,  albumin,  urea  ({wrticularly  in  cholera), 
uric  acid,  caldum  oxalate,  sugar  < in  diabetic  patients),  lactic  acid,  indujo 
{or  indigo-yielding  bodies  giviufr  rise  to  "  blue  "  sweat),  bile,  and  othra:  pa- 
ments.  Iodine  and  pito^iiiiin  iudi<le,  succinic,  tartaric,  and  benzoic  (part^ 
as  hippuric)  iiciits  have  l>een  fouii<l  in  tbe  sweat  when  taken  internally  M 
medicines. 

Culaiievti"  Jitsjiiivtloii. 

$440,  A  frog  whose  lungs  have  been  removed  will  continue  to  live  for 
some  time;  and  <luriiiir  thut  |>eriod  will  coutinuu  not  only  to  produce  car- 
bonio  acid,  but  also  to  cdiisiiux^  oxygen.  In  other  wurd:^,  the  frog  is  ablets 
bicatbe  without  lungs.  rea])irutiiiii  bein^  carrieil  on  etlicicntly  by  means  of 
tlMskin.  In  mammals  and  iu  man  this  cutaneous  rospirntiou  iia,  bv  reason 
of  tbe  thickness  of  the  epidermii',  lest  ricted  to  within  very  narrow  limits  ;  and, 
Mtead,  it  has  been  (juestionrd  whether  it  can  be  s|X)keu  of  at  all  as  a  titie 
nntatioo.     When  llie  body  n^miiins  liir  smne  time  iu  a  closed  chamber  to 

*  '^  the  air  i>assing  in  and  out  of  the  lungs  bais  no  access  i&s  when  tbe 


TBB   IVATl'RB   AVP   AKOPNT  Of   PKR9PIRATI&S. 


I 


I 


IhkIv  ia  «DcI()eed  in  n  1arg«  airliiitit  b«g  fSltiiii:  liglilly  mund  the  ii<v\t,  »r 
wli«n.>  «  tube  in  the  trachen  mrrW  nir  tn  nml  from  [b«  lung>  of  kii  uiiininl 
placed  ill  un  nir-ti);bt  box),  tt  i:*  found  thut  th«  nir  tn  (bo  vhunber  loMH 
oxygen  and  guii»  mrbdiiic  acid.  The  amount  »ri;urb()iii(-  acid  wbirh  i«  lliUH 
thrown  olf  by  ihtt  iikiti  of  an  ava-ragc  nwii  in  twMity-foiir  hoiini  anuMint*  t<> 
about  ID  grni*.,  or  accnrdiitf;  to  work-  otiMTvrre  to  (iio  more  thnu)  altout  4 
grm*.,  iHcreaniie  "ith  «  Hiw  of  lfiu|)cnilun;  ■iid  btiiig  very  innrkrdly  mig- 
mralvd  by  bodily  excrciw.  ll  m  staird  thai  ihc  amount  of  oxygi.ii  con> 
Humed  t«  about  ^qual  iti  voiumt'  to  thut  of  ihv  carbonic  acid  given  nlf,  but 
•onw-  obMrvGn  makr  it  rather  )«w.  It  mav  bu  doubted,  howctcr,  whether 
the  i-arboiiic  acid  comes  direct  from  the  blood;  il  may  come  from  dccom- 
po«itiqii»  tnkinc  [dncr  in  the  Hwcat — of  carbonnten,  for  imlaiice.  f^mihirlf 
the  oxygen  which  di»appear»  may  be  »imi)ly  uwd  to  oxidixiDg  aoiiie  of  tlio 
const ttu en ti^  of  iho  «w«it.  It  is  evident  inat  the  lofs  wbicb  lb«  body  eufl^n 
through  the  fekin  coDsislti,  beeidc  a  ;mall  <(uanlity  of  sodium  chloride,  chiefly 
of  water. 

When  an  animal,  a  rabbit  for  imiance.  is  covered  over  with  an  iniper- 
meabte  vamt*h,  such  aa  ^latin,  ui  that  nil  exit  or  entrance  of  goeeB  or 
liquids  by  the  ekin  is  priM'enied,  dealh  ^lorlly  eosueB.  This  reeult  cannot 
be  due,  as  once  thoui;hI,  to  arrest  of  culancoua  re«]iiralioii,  seeing  how  inei^ 
niflcant  and  doubtful  is  the  gaseous  imerchatige  bv  ihe  skin  as  eomparm 
with  (hat  by  the  Iudkb.  Nor  are  the  tvmti(4iins  at  all  those  of  asphyxia,  hut 
rather  of  Mme  kind  of  poinoning,  marked  by  a  very  gi^at  fail  of  tempera* 
ture.  which,  however,  seems  to  be  the  result  not  of  dimiuiiihed  piuduction  of 
beat,  but  of  an  iiicreaMe  of  th<;  discharge  of  heat  from  the  surfaoe.  The  ani- 
mal may  bu  rulored,  or  at  alt  ereiil*  iU  life  may  be  prolonged,  witJi  the 
abatement  of  the  itymjitomK.  if  tlx-  gix>at  lout  of  bttit  which  in  evidently 
taking  place  bi-  pievniittti  by  (■overinglhe  hmly  thickly  with  <N)tton-n'0(d,  or 
keeping  it  in  a  warm  atmoaphera,  llie  RynipKiroM  have  not  n*  vet  IxtB 
clearly  nnalyn.-d.  but  they  »ccin  to  be  due  in  part  to  a  pyrexiii  or  fever  poa> 
sihly  cautN-d  by  the  n'lention  within  or  rmhiwrption  into  the  blond  of  ttome 
of  tin-  ontmiiiuentif  i>f  ihc  ■went,  or  by  the  products  of  onie  ■hnormal  nvota- 
btdtim,  and  in  part  to  a  dilation  of  itie  cutaneous  vcs^U  caused  by  the  apli- 
cation  of  varnish  ;  owinj;  to  the  dilated  oondition  of  the  ciilitneouK  veaseld 
the  l(w»  of  heat  ihriHigh  (he  skin  i»  ahuonnally  large,  even  though  the 
vnmish  mar  not  be  a  good  conductor. 

§441.  Abtorption  (tv  ihv.  nl'm.  Althimith  under  normal  circiimKlAntifa  the 
skin  serves  only  as  a  channel  of  loss  to  the  body.il  liiu>  been  niaiuiaincd  that  it 
may,  under  particular  circumslancra,  be  a  means  of  Kain,  and  the  little  which 
we  hai'e  to  my  on  this  matter  may  perhaps  be  said  bere.  1_'a«es  are  on  record 
where  bodies  are  said  to  have  gained  in  weight  by  immersion  in  a  bath,  or 
by  exposure  to  a  moist  almoephere  during  a  given  period,  in  which  no  food 
or  drink  was  taken,  or  to  have  gained  more  than  the  weight  of  the  food  or 
drink  taken ;  the  gain  in  such  cases  must  have  been  due  to  the  absorjitiou 
i>f  water  by  the  skin.  Direct  extierimniti',  however,  throw  doubt  on  theae 
•Utemenis,  for  they  show  that  under  ordinary  circumstances  such  a  gain  by 
the  skin  is  slight,  being  aptian-ntly  due  to  mere  imbibition  of  water  hy  Ihe 
upper  layers  of  the  eiudermiH. 

Abanrptioii  of  vnriomi  Hulistances  takes  place  very  readily  by  abraded 
■nrAoM  where  the  denoi*  U  laid  ham  at  covered  only  by  the  lowest  layers 
of  midermb,  hut  it  ha*  hnn  ik-ltateil  whether suhitaneeM  m  atpieous  solutioti 
ewi  M  aL«iiri>rd  by  the  skin  when  the  epidemiit  is  intaet,  the  evidence  un  this 
point  being  (Hinlrudiclory.  In  the  ease  of  tJiO  skin  of  the  fmg  an  aliwirplioii 
of  water  and  of  variniiif  lUilulilc  milu'tiinct's  certainly  luke>  place.  1»  llie  ctUM 
iouud  human  skin  ihciv  arc  no  rt  priori  rcawm--  why  water  cmrrying 

Sfl 


662 


THK    EMMIS'ATIOX    MF    WASTE    I'RODL'CTS. 


•ubMHiiew  <liAi>iU-ect  in  it  dIiouIiI  not  pasi  iiiwiin)  thmuKh  the  oorowui  m 
well  M  tlif  other  layer*  of  ihe  epiileriiiis,  the  minxitii  fi  |iiis<iii;;  (l«ptii()h>)t. 
aniORg  ntbor  tliiu]^.  npun  tht?  (.■miilitiou  uf  the  xkii);  noil  cixiininn  i-u   i 
«D00  MM]n]i>  to  >1ii<w  ihnt  it  iloiat.     Nevt^rlhfleiv,  the  rr^ulu  nt'  ■ctunl  n.  -    - 
iiMtnt  are  con  Hi  cling.     Si>me  dIimtvi'i^   maiulAiii   that  soluble  non-viluil* 
RubsUnce*  aix-  iiul  ahiuirbocl,  mul   lliiil  vulntilc  itiilwtaiicw,  such  u  iixltnC' 
which  maybe  Hi-t^'cted   in  ihp  NyHietii  sfter  u  Wh  eonliiioinj;  ihrni.arr 
alMi>rlie<)  not  by  llie  «kiii.  hut  by  the  miicous  membrnnc  of  ihp  rmjiirBtor^ 
organs,  the  nuliKlaiu-e  nmkiug  'Hf  wiiy  to  the  latter  by  viiUtilizatiAD  rmaa  ik»* 
suriaoe  of-  the  btitli.     Olhvrv.  ngiiiu.  hitve  fouHil  «riileiiec  of  ahaurpti«*^' 
esoeciiLlly  uitli  volatile  Riilwlancoe,  «veii  when  care  has  been  tuk«D  la  aro m-i 
all  «nnni ;  and  the  gmater  weight  may  jierhape  ht>  givcti  to  these,  sincv  ib^^ 
aeooid  with  Gommnti  experieoce.     The  eonfllcl  of  experitnental  r«iull«,  hu^ 
ever,  al  iMist  ehows  that  we  Ho  not  fully  undersltind  tbe  oonditions  ud  ~ 
whieh  Ruch  abMrption  tnke«  place. 

There  is,  mnreorer.  evidence  that  even  solid  particles  can  pass  through  : 
iiilaei  i^kio.     The  lyniphatica  in  the  skin  of  a  newborn  iufaiit  have  W\  ■  .11 
fiiuiiit  crowded  with  the  partielee  of  tbc  peculiar  fatty  aeeretiun  which  ein-e—     n 
the  skin  at  birth  ;  and  mlid  particles  rubbed  into  even  lh«  sound  ?kin  ui&_ 
eei>eciatly  when  applied  in  a  falty  vehicle,  as,  *■.  <?..  in  tbe  well  known 
cury  ointinoni,  find  tbeir  way  into  the  underlying  lymphatics.    Tbe  wande 
ing  leiii''>cyte«  which  are  at  times  found  amun);  ibe  e]Hderinic  oelb 
IwrhaiKt  take  part  in  this  Ifaii^mrt. 


The  Mbciiamsu  of  the  B»-Reriox  of  Sweat. 

1&  442.  In  dealing  with  ibe  manner  in  which  vurioiu  drcum3laneu>  afi:~^ 
tbe  amount  of  Hwenc  ivcruted  w«  may,  as  we  have  already  said,  consider  -^cJ^ 
sweat  as  a  whole  to  hn  supplied  by  tlie  »wc«t-gland»  alone.  For  thouft^  it 
aeema  cvldenl  that  Mime  umouni  of  fluid  muM  poM  by  simple  traiiiudac:.^iM 
through  the  iMiliniiry  epidermic  of  ih"  portions  of  »kin  interveaios  beHr^ewi 
tite  mouths  of  tbe  gland*,  yot  on  the  whole  it  is  probable  that  the  pnrC-M 
which  M>  payees  is  a  i>ma1l  fmction  nnly  of  the  total  quantity  ^creieil  br  tbr 
akin  ;  and  direct  cxjHTiment  shows  that  even  the  sinipte  eTU|M)ralion  of  nK«,tfr 


in  much  i^reater  from  thi.«o  tHirte  of  the  skin  in  which  tbe  glunds  lire  al>  ain- 
daut,  than  from  thwe  in  which  ihcy  are  eiiiniy.    We  have  us  yet  no  rvidt^Wv 
tlial  tbe  sebaccouB  glands  vary  in  activity  ;  tlieir  very  jieeuliar  form  nffc^^f*. 
tion,  if  we  may  spcfsk  of  it  &»  a  accretion,  is  not  adaplfl  lo  HUilden  ehiiia  ^n, 
•nd  at  all  events  wc  have  as  vet  no  evidence  tliat  cireuriiHiani'e*  rapjdlv    auiil 
largely  modify  ibe  amount  of  sebum  ilirchar)>ed  by  In-uItJiy  scbunsiug  gla.Biik 
The  secreting  activity  of  the  skin,  like  that  of  ihe  other  glaiidi*.  is  umb  anil* 
•ocompanied  and  aided  by  vascular  dilation.     lo  one  of  the  early  exK*«i> 
menta  on  divisiim  of  the  cervical  sympathetic.  11  wa^i  olMervcd  that  in      dit 
ome  »f  the  horse,  the  vascular  dilation  of  tbe  fiiee  on  the  side  operated   <a 
ws*  iiccofn{)aniecl  by  increased  pe»piratiu».    Indceil,  the  eonneciiun  Iwtwvera 
tbe  slate  of  the  eutaueoiu  bloodveaseU  and  the  aniouui  of  porspiratJ'Hi    i>* 
malter  of  daily  ohiiervutiou.     When  the  v&iseb  of  the  »kin  are  ci>nsin<7l'<I. 
tbe  secretion  of  the  «kin  i«  diminished;  when  they  are  dilated,  ii  bee* xim* 
abundant.     In  thU  way.  lu  we  *hiill  Inler  011  point  i>ul.  tbe  tem|ienitiii-A  uf 
the  l>ody  is  largely  regulated.     When  the  -urrDiimling  almosphen-  in  wnroL 
Ibe  cutaneous  vissa-b  arc  dilate<l.  lb<-  nnioiinl  of  #wpnt  seervle>l  in  tncresMif, 
and  tiK-  conse<]umtly  nugmcuieil  I'vaporiuion  tends  to  oiol  dunn  the  Irodr. 
On  Ike  other  hand,  when  tbe  aimwphere  U  cold,  the  eulaoeuua  vmhIa  in 


!.  p0ra{iinitiaa  i*  vouity, 
ItMMintion. 

Llaou)«lo);ir  nhlilhcolht'rwvretiutjorgnno  ivliich  we  hnvr  nlrfiulr  «iudi«d 
Ml  nflk  however.  i<>  iiiTor  tlmt  there  ttn  >|Hvinl  nrrv»  ilircvily  governing 
be  anivitr  of  tiw  8iid'>ripur<>iis  gliind*,  indcfH-ntlcnt  uf  vniinlions  in  ihv  \m- 
illmr  fiipply.  And  nut  oiilv  t*  tlii»  \kv  MiggriFlH  liy  miiny  fncte.  Fiich  as 
•f  (irufitw  perapimtion  of  tfic  death  Kgony,  »f  vnriodi  cr'itcf  of  diwam,  and 
certain  mental  enioiioii*.  mid  the  mid  Hwuntj  occurring  in  phtliisis  and 
liar  nmiadNe,  in  sU  of  whicli  dte  ftkiii  ii  unwmic  riiiher  than  hypenuwmic. 
It  we  have  direct  exjierimeutAl  cvidedct-  of  n  uervoua  meohanbiii  of 
'rsjiinUiOD  u  c(>in|)lete  ud  Itie  ru^tmotor  ineohnnisni. 

Jl  iu  the  cal'  ilic  |>eripheriit  slump  of  the  divided  sciatic  nerve  be  siiniu- 
l«l  with  the  interrupied  cunviil,  drop^  of  aweul  may  readily  he  obaerved 

gmcher  on  lli«  luurleaa  s»le  of  lh«  fout  of  thnt  side.  The  sweatia^  is  not 
W  lo  any  iDcrease  of  blood-aupply,  for  it  may  he  oh«erved  when  the  uuta- 
oiw  reanb  are  thrown  into  a  «iale  of  coiiatriction  by  ilie  ttimulus.  or  even 
^•o  tbe  aorta  or  crurml  ark-ry  h  claiiijK^d  pr^TJoiiB  to  the  Minulation,  nnd, 
AvmA,  may  Ih^  ohminud  tiy  tiimulutinj;  the  aciatio  nerve  of  a  recently  ampu* 
lad  leg.  Murvovcr.  when  nlrupiue  hns  been  injected,  the  stimulnlW  pro- 
icos  no  sveat.  lliout;h  viLiumohtr  elTecU  follow  tu  umuhI.  The  i>timl<i);y 
tlTMO  iha  cwm-iflamU  of  ili«  foot  and  »uch  a  xlimd  us  the  mihtnitxillury 

in  fkct  very  doM.  and  Wf  are  jimlified  in  »|ienkiHg  of  the  seuitic  nerve  a^i 
nUiUiiBg  Menilory  fihrm  diMrihuU-d  to  the  eudoriparou*  glandi  uf  (li*r  foot, 
niilar  rvMilli  may  Ui  ohtuiiied  «ilh  the  nervtu  of  the  fore  liiuh.  And  io 
inwivr*  a  copioun  itcerciioii  of  «w<Mt  niuy  he  induced  by  teUiDizing  ttiroiit(h 
i<*  akin  tW  n^-rvfls  of  the  limb*  or  the  face. 

If  a  cat  in  uhich  the  K-iatio  nrn.-e  htut  l>eGn  divided  on  one  vide  bo  exposed 
t  B  liiuh  Icmpemtiirc  in  a  heatrd  chamtwr,  tbe  limb  th«  nerre  of  which  has 
eeo  divideil  remains  dry,  while  the  feet  of  the  other  limbi  sweat  freelv. 
tib  mull  shows  that  the  swejiting  which  L>  caused  by  exiKwure  of  the  body 
t  high  temperaluroa  is  brought  about  by  the  agency  of  the  central  nervous 
fwtteai.  and  not  by  a  local  acli^i  on  ihe  sweat-|[lands ;  for  tbe  fiMit  of  tbe 
Inb  NhiH«  nerve  hu  been  divided  is  e'{UaUy  exposed  to  the  hif;h  lenipera- 
um.  A  hi^-h  ieiu|>eraluro  il  is  true  up  to  a  certain  limit  increased  the  Jrriia- 
illity  of  i)ic  e|Hthelium  of  the  swont-^tand!  and  predisitosM  it  to  secrete,  just 
•  it  proDHXtis  uc'tiou  in  ilie  ca^eiif  a  muscle  or  oerve  or  other  f»ru)i  of  living 
nbttflucei  Thus  sliumlaiiou  uf  the  sciatic  in  the  cat  pnxluoei  a  mueh  more 
ibuDdont  secretion  iu  a  limb  ex|>oied  to  a  lemjieraiure  »f  ■'15°  or  •omewhat 
lbov«,  Uuui  in  one  which  has  been  exposed  to  n  ilialiuetly  lower  tenipenlure. 
lad  in  a  limb  nhich  luu  bei-u  pUceil  iu  ioe  cold  water  lianlly  any  secretion 
It  all  can  be  ^ined ;  but  apjiareutly  mere  ri«e  of  tvaifieraturv  without  nerve- 
MiMuIatMHi  will  uui  i;ive  rise  lo  a  secretorv  activity  of  lh«  ({land*.  Tlu> 
rmating  caiuwil  by  a  dy»j>n<eic  condition  of  blood,  and  lucli  nupvan  to  be 
A«  •wgat  of  the  oeoih  agutiy,  is  similarly  bniujfht  about  bv  die  agency  of 
IJ10  MUtnd  nervous  nstem.  when  an  auioia)  mth  the  acintio  nerve  divukd 
Ml  ouB  fide  is  made  dyspnaic,  no  sweat  apiwan  in  the  hind  lioib  of  ilial  aide, 
tlwugb  abuodanoe  i*  wec-n  iu  tliv  utlicr  fevt. 

Hwralin^  may  )h-  lirrnigfal  about  as  n  rullea  act.  Thu»  when  the  central 
iluiKp  of  llie  divideil  M'ialic  is  Mimiilntnl  xwealing  b  tudu(x-<l  in  the  olh«r 
limbs,  and  in  oiinttlrai  clte  iulmdueti»u  of  pungent  snbttancc*  into  the  moUtJl 
irlll  fre(|tu-nlly  glre  rise  to  a  ciii>ioui  |ienipiraiion  over  the  side  of  the  tkot. 

Iht  baitta*  wita  nf  Um  ftM  bnt  Dot  (m  sdj  imn  uf  ttw  twlr  •■ni^d 

tUMlu  aii.l  otuet 


K  •  Ttm  <M  ■■•«*  fMalr  In 
Hjk  kail*.    Ttwikfalma** 

i ansa  s*—iH.  Urn  Jatu  brti.^       .^  ,  .     _  _         . 

MsaSSStHar  boi  bi  navl  ai  slL    Tb*  tasui  oTiha  Mg  ut>MM  tmlj  :  suil  IM  nnen  ttutiua  •whi-  j 


554 


IMINAilUN    Uf    U  ASIE    I'RODl 


fiioc  itod  wlgcs.  ao  as  lo  give  tho  coll  ■omcirhat  the  appcanutea  ofbthii 
anned  with  n  nnmbcr  of  |>rick)i9U  Henofl  thwa  oell«  are  oflan  odid 
"  [iricklc  cells."  The  |>ricki(9  of  n  c«ll  do  not  interlock  with  Uiom  ■(  lb 
neighbon  but  (oiicli  at  tlip'ir  poial«.  eo  itint  the  contact  of  tiro  a^jaomteeik 
i»  not  complt'tc  btil  carried  out  by  tfao  poinu  of  th«  prickW  only,  niDMt 
spaces  beiag  lefl  between,  llenco  the  whole  MaipighinD  layer  a  tranml 
by  n  labyrinth  of  minute  pusfaj^,  along  which  fluid  can  paw  betirHiiibe 
touchiui;  uricklei. 

Id  dnrb  skins,  aa  tliut  of  the  ne^ro,  pigment  particles  abooDd  in  ilit 
lower  Malpi^hian  ci-lls,  ihipiidally  in  t]i«  I'ertical  layer.  In  Mch  caw 
breached  piKiiit^nt-cclltf.  cimni^clive-tiMue  orpusclee  loa>lt<d  with  pigmeal 
grauules,  are  to  be  lemi  in  tho  dormiM  hIso  ;  and  ocnuiuHitlly  similar  brancliM 
cells  inay  lie  xeea  in  the  cpidcrmi*  brtwccii  the  MalpiKliiaii  cclU.  Leutv 
cytea  also  iml  infrciiurntly  puu  otil  of  the  d«mii»  aud  wM»dar  ainoag  th* 
celb  of  the  Mnljii^hmii  litror. 

The  nuclei  not  only  of  the  vertical  but  also  of  the  oth«r  nolygonal  c«^}» 
may,   uot   unfrvqucntly,    be  oluorvci)    in    varioiix  rtag««   of   kuryutnitci^ 
Til  rou  fill  I  lilt  life  tlic  cell"  of  (his  Malpigliiiui  liiyi-mf  th«  »kiii  appear  l«>  ^ 
untliT^<ii]i|r  null  lip]  initioii  br  division;  the  iiicrciuw  uf  poptiUtion  ibws^ 
iiig  is  kept  down  by  the  cells  pfming  upward  and  outward,  and  beooit*^  i"* 
tnuiffornu'il  into  tlic  cells  of  the  homy  layer. 

$436.  The  line  of  deraarcntion   between  the   Malpighian  layer  nad        "" 
horny  layer  is,  an  we  have  said,  sliarji  and  distinct,     h  is  furnished  by       ^1 

!>C4.'i]iiikr  strata  of  cells,  more  conspicuous  in  some  ngjons  of  the  skin  t--^'"^ 
n  others.     The  lowermost,  innertuost  stratum  coneista  of  a  single  layer  o  -     "* 
two  or  three  lays  of  cells  which  are  uot  unlike  Malpighian  cells,  but  ^ 

diflbrentiated  by  their  form,  beiny;  extended  hortuiuuilly  so  a»  frequent Iji^^.^  ^^ 
apjwnr  fusiforni  iu  vertical  secliuna,  by  the  ab«enco  of  pricklw.  by  lt^K_j|^ 
Mtaiuing  very  tleenly  with  certnin  reagents,  such  as  oamic  acid,  and  '^■^^flr 
clally  bv  their  oell  tulwlancv  l»eiiig  crowded  with  large  dincrele  granulo^^^ 
a  peculiar  nature.     Hence  this  stratum  is  called  thi:  *(ru/uin  jfranutmtum.        —  . 
TlMHlmtum  above  this  ciin»i«ts  of  one  or  two  or  even  more  la^en  ufu—'  ™ 
elongated  and  Hatloncd  hnrixonuilly.  the  coll  sulutance  of  which  i«  ho^   ^n^ 

feneuuK  and  tratisparcnt,  tree  from  gratiule*  ami  not  «4jiiiiing  very  read    ^  '"' 
Q  the  middle  of  a  cell  may  fmiuciitly  bo  seim  it  rod  ihaped  nucleus  pla- 
horiEontiilly.     TheM  clenr  tninspnrent  cclU  form  a  lmn>iittrent  >enm. 
Mfrviliiiii  fiieiihiin,  between   the  slratum   grnnulosuai  and  .Mnlpighiun  ti 
below  and  the  horny  layer  above. 

$  4S6.  Tbe  h»rny  layer,  which  is  as  we  have  said  of  variable  but  nc 
always  of  couaiderable  thickness,  is  formed  of  a  number  of  layeni  of  o 
which.  dilTerentiated  already  in  the  lowest  layers,  have  tbnt  differential 
completed  an  these  pass  upward-  Tbe  upjier,  outer  portion  of  this  ho 
layer  is  ooulinimllr  beiujc  shed  i>r  rubbed  off  in  the  form  of  flakes  nf  v 
able  aire.  Kach  flake  upon  examination,  nt  fur  iiutance  aAer  diaaociaui 
by  niiiceratiou  or  with  the  help  of  alkalies,  is  found  t^  be  composed  of  W' 
roent*  which  can  no  longer  be  re«uguixe<l  as  celb,  a»<l  which  maj  be  spaki 
of  IU  )ichU9.  Eaeh  sciue  la  a  flattened  maw  or  plate  in  wtiioh  no  nu  ' 
can  Iw  Kva.  and  which  omuisu  not  nf  tbe  proteid*  and  otJier  contttiiuent*  a  — 
ortlinary  cell  subatanoo  (S>-9),  but  itlmo^t  excluiiively  of  a  mnterial  calltjc^'^ 
fteniin.  This  is  a  body,  the  exact  nature  nf  whicli  bii*  not  vet  licen  cltarly^it-y 
made  out,  but  which  has  the  general  percentage  coin]Kii>iiion  of  prottidi,  ^^^ 
from  which  it  is  a  deriviilc,  with  the  exception  that  it  contains  a  consMlerabU  ^^ 
quantity  of  sulphur  (,lhe  kcriitin  of  hair  contain*  as  much  as  A  per  cant.):  ^  ' 
this  sulphur  appears  to  l>e  somcivhnt  looselv  attached  to  the  other  clemeoti 
of  the  keratiu  since  it  may  be  removed  by  boiling  with  alkalies. 


r 


THE  9TRPCTTJa«  OP  THK  fUtlS. 


ventiofit  }>-.>rlii>n«  of  the  horuy   layer  ara  compoapiJ  of  eletiK^ntg 
|v  Mill  Ik  reoJVTiized  lu  celU.  iiiiuoiucb  na  each  contaiDs  a  iiucleu*, 
Itia  it  ubviously  undeiyoing  chaii^  and  od  the  vaj  to  dLsappear. 
U  11,  bowerer,  Baiieueil  nntl  plate-like. 
■ubitB»c«  already   coDsisU    largely  of  I"*-  ""- 

[In  pawiD^  upward  fW>in  the  lower  to 
I  tuptrfipial  riarts  of  the  horny  laver 
[tnitK-rfn-t  evil  1iim-«  ilti  tiiicleuH.  andW- 
B  wnolly  kvniliiiixiii  plntc  juiit  di-Hcrilml. 
K  horny  Inrtr  cimiiitU  or  ulnitii  of  t-lt!- 
■rny  to  becin  with,  but  becoming  mom 
\j  to  in  llw  uprxT  part*.  BiToir,  in 
rilh    the   mwm   Slalpij^binn   liivvr.  tbv 

iinuaat  but  thcvutwHicial  pnrlfi  bi- 
by  eTSporaliun  :  ami  briv  tlu-  Htriiln 

rrom  t-nch  other,  the  "titer  <iti(«.  tig 

Ciid,  being  theil  in  the  form  of  ttnhes, 
in  the  ary  coixtition  uiwlcr  the  micro- 
hre  often  the  appearance  of  irregular 

knoniitosis  seen  in  the  cells  of  the  Mal- 
Inyer,  not  only  in  iboae  of  the  venioal 
i in  the  ulhera  as  n'ell.  iliow,  a^  ne  have 
[  thwe  iiiuliiiily  by  diviaiou:  we  have 
IM  of  iDulti plication  taking  ptai-e  elxe- 
tbc  epklermis.  The  tixire  !tu|ierfiriul 
Malpigliiaii  layer,  thruM  upward  by 
icr>,  arc  imn«fi>nnrd  into  the  ci-ll«  nf 
im  KntttuloBum :  and  although  wo  do 
fuHy  understiind  tbc  exact  nature  i>f 
ifornintioR  we  may  conclude  that  the 
;nnulm  of  iheeo  cells  ar«  concerned  in 
tacture  of  keratin.  Chnnt;cl  by  (he 
lk>n  of  their  );ninul(«  in  lliU  mnuiifaL-- 
celb  of  the  ('tmlum  grauulosum  become 
celU  of  the  stratum  lucicuiu.aud  then 
I  of  the  diatinctir  homy  layer,  putilied 
Uirou^h  which  by  the  new  fiiriuatiou* 
Uy  Bucveediiift  below  them,  they  pass  to 
toe  and  are  eventually  xbeil. 
\The  nueat-gliiniit.  A  sweat-jtland,  like 
pb,  oooHtU  of  a  *eeretiuK  ]K>r(iou  niiil 
pSK  portion  [1^;.  \fAi'\.  The  lefreiing 
:  a  long  tubular  alviulu*  coileil  up  in  a 
pUcea  in  thv  nubcutnuemiH  cotinrclivB 
mine  dintancc  fmm  the  cpiilerniix.  Gen- 
t  gland  \«  formed  of  on<-  «uch  tnbule 
:  >nnM>lim(!fl  two  tubuk^  unite  into  n 
lucL  The  duct  beginning  in  the  knot. 
iNivolutionR  of  which  it  *hnr««,  ninit  a 
\  wavy  but  otherwise  Ktmighl  course  vertically  ton-ard  the  surface 
on  to  which  its  lumen  ofH-ne. 

the  epidermis  the  duct  w  nothiDK  more  than  n  tubular  pnsanee 
out  of  the  epidermis  with  a  remarkable  c»rk^rew  coiinte,  tlie 
e  screw  becoiuini;  more  open  and  tlie  oniml  n't<ler  in  the  ujiper 


V' 


8t'i<oKirAai)Mc;u»i>nKiii  twa 
Paui  or  Tin  Banii  lUagnUM 
411  dlamrun.) 

1. 1.  ■xiDlurU'l  lolMi.  nnninlni 
lln  ctend.  *dA  doIUIic  In  two 
•leiMotydilcla^^Z.  Which  unit* 

(DM  mw  (plni  <Bui  UiM  p«rt^ 
OKM  Ika  ipldtnnii  ■■  «,  and  opoa 
itaiurbmat^:  Um  iiuid  to  «»- 
bf  Med  tn  bt-*(tfel<a.  nUtk  an 

Hrli  &I  6.  S.I 


^part  u  it  niifiriMH-hts  the  aurfnce.    In  iIk-  Malpiiriruiii  Inror  iho  «eUi  wfH 
ling  on  tho  |juK«»gi-  mre  flutteaed  mid  iiK-liiK-<l  •l«>tMin iinl  *n  utoftllix' 
'  more  or  ItUt^'U-finilc  lining;  tliotv  i«  n  gimiUr  itrrun^fiiK-iit  hul  tioi  « 
H«ii   in   Lho  vuri)c:oii!>  lK}or.     R«iu'tiiti^'  iIk-  iIitiuu.  in  it  vittlvj  b*t 

1m|)iliii-,  lb<r  pnsMge  beconiM  a  I'Ogtilnr  duel,  with  so  iDdvpttodttiit  t|>ii       V 
iuni  itf  il«  own,  ft  disliDc-l  bnsenicnl  nipinltmiiv  ODtinudua  with  the  u|>^^,, 
eurlnoe  of  tlie  ilprni'is,  iind  iiu  outer  cout  ur  i.-oniit>c[irc  tissue  slMilxlb«CL    m,\ 
in  the  ciuo  of  mnw  of  the  lar{^r  glands,  eiicli  lis  thoec  of  iho  RxiTlft.  v-  j;^ 
I  [ijiun  niuHcular  <ibrt«.    The  epithelium  cunAieU  of  two  or  threv  larvtv       [^ 
Umtnll  rwunded  (.'ells,  each  with  a.  relatively  large  but  absoluWly  (iiuill  t)ui-i^«ju^ 
hjiQerally  ataiuint;  de«{>Iv.    The  cells   leave  a  narroir  tubtihtr  thivad-Lc|( 
r  IVDion  which  is  lined  wil)i  a  v«ry  characierieiic  distinct  cuticle. 

The  duel  coniinuu  to  |»aMeit(  these  i-haraL-i«r<  al'i«r  il  hiu  entered  lh«  knot 
and  t>eguD  l«  pumite  a  twiMed  ociiinH*,  hul  «h>u  cliiuiKes  uiddeiily  into  tb« 
Kcretiu}(  tubule.    Tlii.i  may  be  di»tin){ui^hed  fnnu  the  <luol  by  beinj;  viitr, 
and  by  being  tiiird  by  a  ninglv  layvr  of  ciibieal  ur  oolumuar  oelu  larger 
than  thine  of  the  ducri,  heurin);  utrger  ntiolei.  aiid   behaving   diflereulj 
towani  variouii  ntnining  rva^nbf.    The  lumMi  though  fairly  dialinel  k  M 
Jiued  by  auv  eiilirlv  tu  in  the  diicU     Lyi"S  l><it«rc«u  the  bunenwut  men- 
braoe  and  the  c|i!lliclial  rells,  or  rath<<r  iinbcdiil  in  the  bibunieat  uienihnuit, 
an  seen  a  nuniWr  of  plain  nmecular  6brc«  dixpoM-d  lungitudi Daily  or  iii  aa 
elongated  spiral,  and  often  forrniiig  a  distinct  coat  beneath  tb«  epilhi'liuin. 

A*  in  the  case  of  other  j^laiid^.  we  are  unable  to  aiakv  any  fiatrtia-ni  u 
to  tlia  work  carried  on  by  the  epithelium  lining  the  duct,  hul  «e  may  prob- 
ably asume  that  the  sweat  is  iiminlv  ^ereiod  by  tho  larger  mlU  of  th* 
torniiiial  coiled  partoflbe  tubule.  TEiese  cells.  iherefoni.lik«othi-r»ccrvting 
cfll*.  are  probably  "  loaded  "  and  <lisch»rged ;"  but  as  yet  no  marked  itruc- 
tiiral  chanfEca  in  the  i^ells  ciirres[>ondinK  to  theee  pbaeca  have  beea  MUk&c 
torily  luceriaioed,  thoujtb  after  the  udokiiiistratioii  of  pilocarpine,  which 
cwiscA  iweatiiiK:.  the  cell*  of  glamU  hardened  in  alcohol  staia  more  deeply 
than  usual  with  rarinine.  It  miml  ix  rvnicmliered.  however,  that  the  HVeat 
GOUtaiiiH  norninllv  neither  niueun  nor  proteid  Hulvilaucef,  aud  we  ijliuuld. 
lherefi>rti.  not  expect  to  obnorvo  "gr«nul«"  in  the  cell*. 

The  pHTuliarly  placed  muscular  fibres  have  been  *upi>oiei>l,  bv  their  oon- 
Iraciiou.toasHst  in  thfl  flowofswoat  along  the  tubule.  lu  c«rtaii)  cutaiiiMxu 
ghiiidK  of  ibe  fi'i>g.  of  a  relatively  eimple  natiia-,  llicre  w  erideiiee  thai  the 
w.-erettoL  is  ejected  from  ibe  comparatively  large  lumen  by  the  coninieti'Xi 
of  iiliiiu  niuoriilar  fibref  in  the  wall  of  the  }.'hiiid,  ur  by  a  <viuiracii<>ii  nf  tite 
wr:ill  iKrIf,  which  i.t  e»iiu-actile  without  being  dtstiiietiv  diBbrenliated  into 
mi»cular  tissue.  And  this  rather  supports  the  above  vien  ;  but  the  iitaiMr 
is  at  present  by  no  roeaiis  clear. 

The  coil  of  a  sweat-gland  is  well  supplied  with  bloodvceaels  in  the  form  of 
capillary  netwtirlis.  and  nerves  hare  been  traced  to  the  tube* ;  but  tbe  exact 
manner  in  which  ibtsw  end  in  uol  as  yet  knowii. 

Thoiigb  preac^nt  in  all  regions  of  tlie  akiu  (of  roan),  the  sweut-glanda  are 
une)]ually  dtstrihuUK].  being  more  abundant  in  some  regions,  such  a«  the 
palms  of  the  hand,  than  in  othera.  In  the  axilla  are  glands  of  Terr  large 
Hie,  and  in  tluve  tlie  iliii-t»  pivtieas  dtMiiictlv  muacular  coatd. 

^  438.  S'i"te">'u  ijlamh.  |  l'i)c-  ItiO.]  't'htwe  are  appendages  of  the  liain. 
A  hair  i*  a  devt^lopmcnt.  in  the  form  of  a  cylinder,  of  a  cap  of  cinieuuA 
et>idermi«  iiurmounliiig  a  piipillu  of  the  denuin  >iuik  to  the  bottom  of  a  tubu- 
lar pit,  »r  involutiriu  nf  the  Hkin,  called  a  bair- follicle.  In  the  upjter  (>art 
t>f  the  hnirlutlicic  the  wall*  eoncifl  of  onlinary  !>kin  with  all  it»  parl4. 
dermifi.  Malpighiaii  laver  and  conioou*  layer,  the  latter  at  unual  ol  cou- 
nideiable  ihickuuH-     At  wuue  little  diMancv  fnim  the  muutb  ul'  Llia  ItfUicla 


-> 


1 

* 

m 


n 


'•'  Uyfr  :>u>l')ffilv  (^-iiH-^,  an'l  in  tbi'  fullioK-  in-low  lhi«  llio  C|m- 
[«lif ,  ,   ;>m»iniii><l  liv  ihc  Miiljii^'hiiin  luyi-r,  imw  onllci)  il«'  uuter  rrwl- 

'  ■hi'kili.   uixl    twii    Inirors   nf   jH-c'iiluir    o'lls, 
forming  itii-  innrr  r<Hil->hr«tli,  nt  which  (he  fPi".  i<u, 

■Hitrr  i*  •-nllvtl  Hoiil«'«  Mlij  lhi>  inm-r  lliix- 
.l«v'»  Uj>'r;    ihi,-*)   nwr.  iwrimja.    he   cna- 
^~^^tn'i    ft»   comoponrling   In  ihe  stratum 
Duliitum  Knd  lunitium  r»peetively.     The 
Dia  of  lli«  wall  of  llic  rolltcio  U  nt  lli« 
kBw  linif  <kvrl<>j»l    into  no  outer    layer  rfi 

ith  iHiti'lh*  of  oiiiiicclive  tiwue  <)is|M>!)e'l 
"liHlv  If'Dgituiltiiiilly.  niiii  an  inner  layer  of 
jluir  natiirp,  the  arranKeiDent  of  shicb 
I  Usoavenc.  bikI  wliicti  at  lenat  titirDuliiiGS, 
'  it  nallr  be  oo4.  a  iDiismilur  ininsverw 
Bctweeu  tliis  dermis  of  the  fnllifle 
the  oaicr  root-«JiMith  or  Malnighiun 
b  a  very-  eonapicuoun  il(>finitr  hynline 
t   nieniliraDe,  *u  thick   that  It  pre- 
t*  «  very  cuily  rec>jgnin,>iJ  double  oou- 
'«eur. 
I       At  Iho  ImiUoiu  of  thi-  follicle  the  ilrrmiK 
B  of  tbr  wall  uf  |h«  follii'le  i:>  rontiniinUB  with 
■AeMilutance  ot  One  (<krnii<-)  pnnllln.  while 
FVe  tiiitrr  roM'thcnth  or  Malpiyhinn  Ittror. 
obtch  b«r«  bcvomni  esircmelj  thin  nmf  re- 
i^c^l  to  tmv  or  two  laym,  ii  rtllcclwl  over 
l^  pniiilla.  and  llv-rc  expands  a^in  inlu  n 
<baw>    <'f  nrlU.  whirh   like  (lie  celU  of  ibe 
^liil|>i>;hian  layer  in  the  resi  of  the  skin 
biulti[>lv,  and  hy  iheir  nntltiplieniioii  atve 
i-n'  !•>  tl>e  corneous  body  of  the  hair.     It  iit 
■ajfl     iIhii   in  those    hair^  nblch    {HiM^n*   a 
ullu  th*  vertioillv  di^puned  lowtrni'iol 
]m    of  llie    Malpiitbiiin    Inrer  lire  ni  iho 
«(u«l     nimniit    of    t)i>-    jmpillii    eoniiiiued 
ipwanl   iu  the  axia  of  the   hiiir,  ni>  the 
-tilla. 
Ttw  layer  of  Henle,  f-illonin^  |hi>  Mill- 
V>t)ebian  layer  or  nuirr  rfHitflivatli  ou  which 
St    mta,    is   Mmilnrly   reflected    and    fomi« 
^ivrr  tl»e  linir  a  single  layer  of  flat  trani*- 
{«rent    inihrimeid    M-alea    known    as   tin- 
ctitiele  of  the  hair.     lluxlerV  layer,  ami- 
larly   rrflwte<l,   Ibrms  a  iimilar    luyer  uf 
atnilar  atsl««.  but  thi»  is  eom-idered  as  be- 
lancing  lo  tbe  root^icnih,  and  is  called  tiw 
cuticlv  of  the  rool-sbcalh. 

Jiut  where  tbe  eomeoua  lover  abruptlv 
Icarasofl'  in  the  upper  pari  of  the  hiiir  fol- 
Ucle,  a  aebaoeoiis  nloikl  opens  into  (be  cavity 
of  the  follicle  on  each  side  of  tite  hair. 
Karh  irlttnd  iiinaistA  uf  n  abort  rather  wide 
dorl  niiich  ditidai  inlu  a  clusler  of  some- 
■hai  fluk-ibaMtl  alveoli.  The  baMfltfot 
oirnihtnor,  both  in  the  alveoli  and  in  the 


lliia-rMurK  w  LowanvMiH«l> 

a.  ^siuliuffoltklo:^  nivk;'.  bulli^ 
d.  r.  Avnnlc  «iM :  /.  oaUtr  roD«-d>cal>i ; 
#,  innci  mnt^thMlli :  K.  Iiatr :  t.  It4  tiie- 
milla:  '.  Iialrkni'li:  •^•^l|«Uw«: 
n,  tMlr-muKlf^  a.  jmvttltt^  tUn;  p, 
■■pllta  of  liBlr^  •.  >««•  Batmiiin.  one- 
UnuMi  widi  iMiu*  noMbnih  -.  tp, 
iKmjr  layw :  t,  •vtapewia  clkiid.) 


568 


TUB    KLIUINATION   OK    M'ASTE    ['BOUfCTS. 


duct,  is  tiaed  witli  ii  laytr  of  rntliftr  sinill  cubioil  cvlla  coiiiiououa  wiib  i  j 
layer  uf  i)crpctii]iculnriy  d»p<w<nl  cells  wlik'h  Ibrm  (lie  innermost  Injtr 
the  outer  rout-»licftth  u  of  the  IklulpiehikU  layer  of  the  skin  eenml  J 
ThU  Inycr  of  cells  leaves  a  wide  lumen  both  ui  liie  alveoti  mid  in  iht  ilu^^ 
this  lumen,  however,  is  occu]>ied  not  as  in  other  inlands  with  6uid.  but  «  5 
cells.  Holh  alvcnli  and  duel.  In  fact,  are  tilled  i^ilh  r«>uiided  or  ImItl'u^* 
eells  which  may  be  regarded  as  mixlitied  cells  of  iJ»e  Malpighiaii  la>^^ 
The  whole  gland,  indeed,  is  a  s>tlid  diverlienluin  of  ihe  Muliii};hiaD  Uvi-f_      1 

In  the  alveoli  the  cells  next  to  ttie  layer  i>f  cells  iiiiiiititiat<rly  Huiuij    «  k 
haa«!iiieui  nieiubrane,  though  larger  Ihmi  tlieae,  reaeiiibk-  iheii)  in  m  far  iVu| 
each  consists  of  ordinary*  eell  i«uluiatiee  uurMundin^  a  nucleus  of  onlioaM 
character.     The  loore  ceiitrul  celli«  are  •iillvTciit ;   their  i.-«ll  iiuWiam-v      ^ 
undergoing  change,  utiuierouH  j^Taiiutes  or  dropk-ts.  nmie  i>f  them  obviixa  « r 
of  a   futv  nature,  inake  their  niijiciiraat^  in  them,  nod  lh«  nudi-i  ar«     l>^ 
coming  shrunk  and  altered.     The  itilU  aiv  miinufai-turinu:  fntly  am)  ullK-r 
bodies  and  (ivp'isitiu);  the  tiroducts  in  thriir  own  nubsUinoi-.  which,  hoitrvvr, 
b  not  bein>;  renewed,  but  in  i]yiii)(.     Thciv  chanjrM  are  *lill  murt*  obviom    it 
the  cells  Iving  wilhiu  the  diivi ;  the  celU  as  indicatvtl  by  the  bmtking  ii|*  i^  | 
tho  nuclei  an-  dead,  and  the  whole  of  the  cell  KuhstaDoc  )iiv>  Ih-cu  trao*-  < 
formevl   into  the  material  constituting  llic  wcrvtion  of  the  gland,  called 
iwAurri,  whidi  is  diicbarge<l  on  to  tlic  nurrHoe  of  the  Hkin  tJirough  the  nt^iui^ 
of  the  hair  Ibllicle. 

In  tliMC  nebaectiUH  gland* ncorctitms,  if  wo  may  continue  to  use  the  irori, 
tak<4  placr  after  n  fashion  dilRtrent  from  that  which  we  have    hithcne 
atadicd.     In   an  ordiniiry  gliind   th«i  cells  lining  the  walls  of  the  sln^    I 
manufacture  iniilcrinl  which  they  discliarge  from  thcmselros  into  the  luim 
to  form  the  nccrctioii,  their  own  aub«tance  being  at  the  same  time  renewed, 
so  that  the  lame  cell  may  continue  to  manufacture  and  discharge  ihe  sect»' 
tioo  lor  a  very    prolonged    period  willioul    beiu^    iuelf  ilestroyed.     Is  a 
•ebaceous  gland  the  work  of  ihe  cells  immediately  Hninj;  the  wall  of  am 
alveolus  np(>eai'8  liuiiteit  to  the  task  of  iucreaniuK  by  miiltjplicjilion.     Of  the 
now  oell»  tliiiB  fiiruied,  while  some  reiimin  to  continue  the  lining  and  to  carry 
oil  the  Work  of  tla-ir  predeire.'uors,  tbe  re^t  thrust  fiwanl  the  ocntre  of  tlve 
«lve»lu«  are  l>i>dily  t ran  14 formed  into  the  material  of  the  i>ecretion,  and  during 
tho  trmnnfonnution  htv  punlied  uui  tliroUKb  the  duct  by  the  generation  of 
new  cells  behind  them.     The  ;>ecretinH  of  sehiini,  in  fact,  it  a  ntudificatioD 
of  the  iMrticuhir  kind  of  iieereliun  taking  place  all  over  the  skin,  and  spoken 
of  lu  Sledding  of  the  skin.     It  is  cliiefly  tbe  cliemicid  transformaliun  which 
is  difi^rvnt  in  the  two  cum.-*.     In  the  skin  gciierally  the  protoplasmic  cell 
eubetancc  of  the  Malpighiim  ivlls  in  traniduruicd  iuto  keratin ;  in  the  seba> 
ceoia  glands  it  if  tranKfornied  ii\U>  ihc  fatty  and  other  cfiustituenta  of  tbe 
•ebom.     Some,  [M.-r1iii|n>,  may  ht^itikle  to  apply  the  word  secretion  to  fluch  a 
ptOOMB  U  tbis :  but.  a*  wc  vhiill  ore  Inter  on,  ibo  f-irniation  of  milk,  which 
eertainly  deserves  to  be  ci)I]e>]  a  secretion,  is  ■  proecw  inicrmediate  between 
thenCKtioD  of  saliva  and  gastric  juice  and  the  fl>rmation  of  sebum. 

The  w-callcd  "  ceruminous"  glands  of  the  external  meatus  of  the  ear  an 
easentially  sweat-glands.  They  are  wrongly  named,  since  the  fatty  muerUJ 
spoken  of  as  "  wax  "  of  the  ear  is  secreted  not  by  them  but  by  the  Mbacaoui 

fjands  t>elunf(in){  to  the  bain  of  the  nteatua,  or  by  ibe  general  epiderniir 
ining.     The  ceruminous  glands  appear  at  most  to  supply  the  pigromt  which 
onion  the  "wax." 

Tbe  Meihumiaii  glanda  of  the  eyelids,  on  the  other  hand,  are  GweotiaUy 
the  sebaceous  glands  of  tbe  eyelu^lies,  the  glands  of  Mohl  being  in  turn 
vwent-glniids. 


Tbk  Natvbb  and  Aiioiryr  or  PeitaviKATiox. 

t  438.  Tlie  ((uanlitv  of  matter  which  leavce  the  buiuau  bwly  hy  way  of 
tlw  akin  to  rtrjr  ooD«l<li^rati1c.  Thus  ii  lins  lioi'ii  e»liinaiv<l  thitl  vrhik  O.Q 
graniDa  paan  Rwrnv  thniujch  thv  liiiitc"  [x^-r  miiiuio.  h.h  much  ti*  0.8  gramnw 
MMSlhrough  th«*Kin.  Tltviin)iiiiut,ii<twevcr,  varies  uxtn'mvly  ;  it  hiu  bi-^ii 
oBtcatUftl.  nvm  dain  gniiMM]  by  (■ucluiiinK  ihv  arm  in  a  uaixiic^huiio  Imjc,  that 
ibt  IflUl  KDKMint  of  pi'n>|>inttioii  fntm  ihr  ii'bult'  kiMly  in  tirvnty-f.mr  boiira 
Bi^it  nuige  fruiii  2  to  iO  k\U»:  but  iiK-b  a  mmU  nf  <3ilcuUtioii  is  obi,'iou»ly 
a(>m  lu  mHDV  nMTvet  of  vrror. 

Uf  tht;  wtviilr  antmiDl  ihiii  diiurhargiKl  |mrt  |]ii«^s  away  at  once  ■«  wnteiy 
nfmr  iniitd  with  vrihiiiti;  iiiatlors,  wbilu  part  may  rfmaiit  for  a  time  n*  a 
fluid  (Ml  the  skin  ;  tbi'  Itu-incr  is  rreiiufntly  8pi>ki.-n  of  n»  i»mriifi/tlf.  Ibc  hilier 
a*  tniMt,  penjiiratioii  or  nwml.  The  [ir<>|>nrlioti  of  tho  inieiisibk  lu  ihe 
teatihle  penpintion  will  ilcpond  on  the  nipidity  of  the  Hcrclioii  in  rer^renat 
bt  the  drynne.  tcttiprntiinr.  and  amount  of  movement  uf  the  Hurruiiiidin}; 
stacijibere.  Thus,  #upp(»ng  th«  rate  of  Kcrction  to  roniRiD  conelaut,  the 
dnr  and  hotter  the  air.  ana  the  more  rapidly  the  Kirni«  uf  air  in  cnutai-t 
wkblbe  body  are  renewed,  the  );reRter  i*  the  amount  of  iKnuible  [lerapirat iuii 
whitti  b  bv  evajKiraiiun  converted  iuui  (lie  insensible  condiitoa ;  and  vm- 
vvnrtv  whcu  tbe  air  ia  cool,  moi«l,  and  Klagnant,  a  larj^  amount  of  the  total 
f'^'niiimicu  may  remain  on  the  skin  an  sensible  sweat.  Since,  aa  the  name 
''npbai,  ««  ue  ounelves  aware  of  tbe  seiL^ible  penpiration  onlv.  ii  may  ami 
"HiflMlitljr  does  happen  ihat  we  eeeni  to  uur»dv(S  to  be  perapiriiii;  largely, 
^^Vn  In  mlity  it  u  not  su  muob  the  total  penipiratjou  whii^h  n  being  in- 
^*^m$td  M  tbe  relative  proportion  of  the  seiinilile  |)eraj)irati<in.  The  rale  of 
^~  ■vtion  may,  however,  be  m>  muob  increased  that  no  amuuni  of  dri-iii.w  or 
t,  or  oMtvemeDt  of  the  atmosphere,  U  autfitieiit  to  carr}-  out  the  neecsMr)' 
k  - ^poratioo.  and  lhu»  tbe  teuime  penuiratioo  may  beoone  abumlaut  in  it 
^*^t,  dry  air.  Ami  praciically  thia  is  tli«  ii#ual  occurroace,  since  certainly 
^  ^>i{h  tero{)enitiin-  conduces,  as  wk  xhull  point  out  pnwODtly,  to  an  inonue 
_^   the aecretion,  and  it  ii  poaoible  that  mere  drynew  of  th«  «ir  has  a aimUu' 


Thu  amount  of  pers{>iration  given  off  is  aflected  not  only  bv  the  couditiou 

T^^  tlir  atmoapbere,  but  abo  by  the  circumatancea  of  the  bt>jy.    Thus  it  is 

^flueaoed  by  tbe  nature  and  quantity  of  food  eaten,  bv  the  amount  of  fluid 

^*»UDk,  by  tUe  character  of  exercise  taken,  by  the  relative  activity  of  the 

*^>tH«y  excretiojE  orjnuiB,  more  particularly  of  the  kidney,  by  mental  condl- 

^■4a(is  and  the  like.    Variations  mav  al>^o  be  ludueed  by  druf^  and  bv  dUeued 

^a<an«)itioDa.   How  these  various  in^ueutvs  produce  iheir  effects  we  sliall  study 

Kunnedtatelir. 

liiv  duid  pentpimii'iu.  or  sweat,  when  collected,  is  found  to  be  a  clear, 
^solarloM  <lui<l  of  a  diitiiiotlj  salt  taMe,  with  a  strong  and  distiiici!%'e  wior 
^mrring  ncr^irding  to  the  part  of  tbe  body  fn>ni  which  it  is  taken.     Bi»iil«s 
Accidental  •■piilcrraic  scalea,  it  containti  no  structural  elements. 

^weat,  m*  a  wtiole.  u  furnlibed  i>artly  by  tbe  sweotglaiids  and  imrtly  by 
the  sebaiovouN  glands,  fur.  as  we  »hull  !»ee,  the  small  amount  nhicn  siroplv 
tTUtsudea  through  the  epidi^rmb.  aiwrt  frum  the  vlandii,  may  lie  neglected. 
If  ow,  the  sevTMions  from  these  two  kinds  of  jflands  difler  niilcly  in  nature, 
■ud  tbe  characten  of  the  sweat,  as  a  whole,  will  vary  acomling  to  the  rvla- 
tjra  proportion  of  tbe  two  kinds  of  •wrvtiun.  The  aecreliod  of  tbi-  seliMOOUua 
gtaails  appears  to  be  Curly  constant,  the  larver  variatioiu  of  the  total  sn^t 
depending  chiefly  on  the  varyinit  activity  of  die  sweat^btmls.  Hence,  wlm 
sweat  is  scanty,  the  wnstituctits  of  the  ■cbuni  influence  laiifely  the  charac- 


580 


TUF,    ELIMIKATtON    OP    WASTE   PROIll'CT8. 


ten  "f  till'  »«i-iil ;  wliou.  i>u  the  couirurc,  the  aWMii  U  verr  nltuuftanl,  ilie- 
rnnr  Ih-  ■li»r<,>^rili-<i,  uiii]  ihe  aweai  tuny  be  cuuuJerett  m»  ibe  pniliK't  of  il 
BrnfHtglitiiiU, 

We  sm  not  iiMu  ui  rir<«(Uit  to  miilce  a  coiu|)l«t«  •tatvraent  »»  m  wh 
bodies  oL'ciir  rxclufiivvly  iii  t\m  wtiiiiii  iiml  uliat  Jii  tbe  Mcreiiuii  nl'  die  #Wi 
glandf .    Tilt.'  furmcr  coii^ivlii  very  \aiw\v  vf  fata  und  fiitty  iioids,  nnd  «(>[••«- 
ta  contuiii  bohip  form  or  fiirinv  ft  pruteiiii ;  but  1K  luivc  iTJUHjn  la  thiiiK  th-^^^j 
the  ewent-^'lRnd!  #t^.-rctv  in  >auUI  quiinUty  hmdc  foniu  i>f  t'lit,  itix)  c«p«ci*l  J3t 
volfltile  fattT  nodd. 

\\'hei]  mem  it  fcuiily.  llic  mtdion  is  mn«nillj  acid,  but  n>i«ii  nhumliix-:*^ 
ia  alkaline;  nod  witen  ii  jiuriioii  uf  the  »Kin  i«  w<'II  woebi'd  the  sw<«l  whi  ^:^ 
b  colleitc'i  inniicdintcly  nfU-rwKrd  is  usimlly  tilkidiiu'.     From  this  viv  nia«r 
tafer  thai  the  secretion  uf  iho  Kweai-glnnds  »  inuiinilly  Rlhiline,  but  tl^«r 
nben  mixed  swcjit  is  soid  ;  the  additv  duo  to  fiilty  (or  othor)  iicids  of  thr 
llebun).     In  (he  horse,  which  is  Nngular  among  hnir-cqvrreil  anitnale  fur  itt 
IVe<iuent  prufii^  sweiilin^'.  the  sweat  is  said  to  be  always  arid  nnd  to  contac* 
a  ciin^iderahlu  ijuanliiv  uf  fome  farm  of  proleid.     Tbese  teaitired  are  profn- 
l>ly  due  lu  the  large  admixture  of  Bebmu  IVt>m  the  nunierauB  sebaceous  Ktea4t 
connected  nith  the  liaire. 

Taking  urdiuary  sweat,  such  na  may  be  obtained  by  eticln»ing  the  arm  in 
n  bug,  we  may  aav  that  in  man  the  Hverage  amouni  ol'  solids  is  I'rum  1  in  ~ 
per  c«Dt.,  of  whicb  about  twit-thinU  eoiuiist  af  organie  subMaucat.    Tl>e  cbt 
normal  coiiMitueuts  are :  (1)  Sodium  chloride,  wilh  «<man  (juautitiei  ofotlii 
inorgiinic  naltn.     1 2)  Variouit  acids  of  the  fatty  series,  such  as  formic,  acetic, 
butyric,  with  probably  propionic,  caproic,  and  caprrlic    The  pru>enii>  <^ 
thivc  latter  is  inferred  rrnm  the  oilor ;   it  in  probable  that  miuiy  nrious 
V'dnlilc  aciiU  are  prcMiit  in  small  qiiantilies.     Luetic  acid,  nhichha*  been 
rcckimcd  lis  a  minnal  ri^Dsiiiiicnt.  is  stated  not  to  !»•  prtscnt  in  Itcallfa. 
(It)  Neutral  Ints  and  choleelerin ;  ihvt/n  have  been  dt4ccl<Hl  won  in  placea, 
such  as  the  palm*  of  the  hniid,  where  whac-eoiis  glaixls  are  preaent.    (4)  'Die 
evidence  goes  To  show  thnt  neither  urva  nor  any  ammonia  compound  exuU 
in  the  normal  secretion  (o  any  extent,  though  some  oWrvera  liaTe  found  a 
coui'idcrablc  i]unniity  of  urea  (calculaled  at  10  grms.  in  tbe  Iwenlv-four 
hdura   I'or  the  whole  body).     Appntvntly  some  S'MhII  amount  of  niLmgrn 
leaves  tiie  body  the  skin,  as  a  vhole,  but  this  is  proliably  supplied  by  (lis 
lebuia  or  by  the  epidermis. 

In  various  forms  of  diiensc  the  sweat  bus  been  found  Id  contain,  «omrtiinm 
in  coiuiderable  qunnliiies,  blood,  albumin,  urea  (jmrlieulurly  in  chokra), 
uric  aciil.  cakiuin  oxalate,  sugar  (in  diabetic  jMtientsj.  lactic  arid,  indigo 
(or  indij.'o-yiehiinjf  bodies  ffiving  rise  to  "  blue"  sweat),  bile,  and  other  [«jf. 
ntenis.  loiline  and  potassium  iodide,  sumnic,  tartaric,  and  lienznic  ([lanly 
as  hipjNiric)  acida  have  been  found  in  the  sweat  when  taken  ium-njilly  na 
met)ivin«4. 

CUtMSOiM  ifoyitrartow. 

{440.  A  frog  whose  lungs  have  l>cvn  removed  will  continue  to  live  for 
•omfl  Ume ;  and  during  thnt  jwriod  will  continue  not  only  to  produce  car- 
bouio  acid,  but  also  to  c»nstim<;  oxygen.  In  other  words,  tl>e  frog  is  able  lu 
hrenihe  withotit  lungs,  rcspiralioii  being  carrinl  on  ctKcieoily  by  inonns  of 
■he  ^kin.  In  mammals  and  in  man  ihis  cutaneous  rcspiralinn  ii^.  by  reasoa 
of  the  ihickueas  of  tbe  epidermis,  icslricted  to  wiihin  very  narrow  liuiu;  and, 
indeed,  il  has  been  ijncetioned  whether  it  can  be  spoken  of  at  all  as  a  tni« 
rtniiiration.  When  ihe  U^dy  remains  for  some  time  in  a  closed  chum)H-r  to 
which  tbe  air  jMs^ing  in  and  out  of  the  luU);8  hoa  uu  aoueas  i,a>  whin  iba 


TUX   .XATVRK    AND    AUOLNT   or   PERSf IRATIO.V.        fitil 


fpm 


l-ntri] 


■4  encltwed  id  k  Inrge  air-tight  biif;  6uiag  tightlj*  round  tli«  oeok,  or 

m  liib«  ill  lli«  tracheM  <'nrri<'ti  sir  to  and  from  lli«  liings  of  an  auiiiml 

I   in  an  iiir-ti(;lkt  box),  it  is  found   that  tlie  air  in  tlw  dmmber  loMS 

and  jtaioti  nrbonic  acid.   I1i«  amouni  of  cnrbooio  add  w)ii<^)i  is  tbua 

wo  oH'by  tb«  alio  of  an  areraKv  man  in  twciiiy-tour  tiour^  amounls  to 

I  10  gm*.,  or  BCConliDft  to  lonw  otMerveru  to  (no   more  llinii)  aboiil  -I  i 

iurrvuine  with  a  riM  of  temperature  snd  being  very  luarkedly  nut;- 

by  budiTy  exerctfe.     It  b  Btaled  that  the  amount  of  DXVf^eo  cuu- 

tao}  ia  aboul  eijuai  in  volume  tu  thai  i>f  the  c-Hrbuiiic  acid  giviMi  uff,  but 

itDP  obMFYen  make   it   mtl>er  It^.     It  tunr  \-v  dotibted,  Imuevr-r,  whether 

rliduir  acid  i^otnn  direct  from  the  hlouil ;  ii  may  cotDe  from  <lecoin- 1 

ni  (akiiiic  jilnci-  ill  thu  awent — iiT  ciirbunitln'.  fur  iDitanc«.     Similarly 

osjgen  «hi«b  <ttfs]>[H-ani  may  Ih-  yiiiiiily  ii-iril   in  oxidtdn^  wiitin  of  the 

fiMMtltitcDia  of  tli«  Hnciit.     h  i*  rvid«Dl  tiuil  ihc  l«**  nhich  tlic  body  KtiHbrw 

ibruuKh  llic  *kin  ruiuiNlii,  Iwviilr  ii  uninll  (juimlity  nf  widium  cbtoridi^  chiefly 

ofwUr. 

WIm'd  an  animnl.  a  mbbit   for  ioMnnn-.  i«  onvvrvd  oTcr  with  an  imper- 

MaUu  vamUh,  «irb  a*  griaiin,  so  thitt  all  oxit  or  volmnce  of  gaMc*  or 

lk|iiiib  by  (hv  *kin  is  prfvetitcd.  drnih  abortly  enaun.     Tbis  mult  ennnot 

W(la#.  ae  vaw  itMNi^iht,  to  nrn»l  of  cii1ni>coii«  rrapinilion,  Mcing  hov  inigg- 

ailtcaiil  and  doiilrtful  it  the  gSficou»  interchange  bv  ibo  «kiu  w  romjMrcI 

>ilj)  that  by  thu  l«og«.     Nor  art  tite  svnipti>ni8  al  nli  tbwr  of  n»)ihyxin.  but 

ntJivr  of  ftome  kind  of  putK<ning,  ninrke'l  by  a  very  grmt  fall  nf  tcnipora- 

lurr,  which,  howrrer,  scent*  to  l>e  ibe  result  not  of  diminished  production  of 

amt.  hot  iif  an  increnm?  of  (lie  diicbar|i(e  of  heal  from  the  surface.     The  tini- 

BmI    luay  lie  restored,  or  at  all   events  its  life  may  be   proloDged,  with  tho 

ahftCrniciii  of  the  »yniptonis,  if  the  great   lut*  of  bent  nhich   b  evidently 

Uktii);  place  lie  prevented  hv  iiiver'tiig  the  body  thickly  with  collon-wool,  or 

kw|nnK  it   in  a  wiirni   ainiiMpht-re.     Tl»c  tymptomN  have  not   an  vrt   l>e«n 

slenrly  BiutlyM^I.  but   iIk'v  m^m  to  lie  due  in  juirl  to  a  pyrexia  nr  lovvt  po*- 

ix  anaed  by  the  n-iention  within  or  rentworpliun  intu  tho  hIo<Hl  of  agnic 

UM  CMMtitiienlf  of  the  «weat,  or  by  the  pr(>i.luc<«i  <d'  wome  ntniomtal  mMN- 

liw,  and  in  jMit  to  a  dilulion  of  the  ciilAncous  vcswls  oniHed  by  tbo  aplU 

c&tti«  of  vnmish :  owing  to  (he  dilntc<l  condilioii  of  the  ciilaiietnn  ve«cl« 

tt»«  la*  (if  bcMt  thruugli  the  ekin  is  abnormnlljr  Ini^,  «v«n  tJiougb  tba 

naniih  mar  Dot  be  a  gwxl  cnnduclur. 

SMI.  Aotorpli&n  by  the  »Jtin.     Although  under  normal  rirninuliincca  th« 

*k>a  MTveaonly  as  a  coannel  of  loaa  tn  tli«  oody.  it  ha«  benn  nisinininnl  that  it 

"■^r.WMfer  |iarti<'iilar  circumstances,  hen  means  of  gain,  atxt  the  little  which 

**  aavc  to  say  uii  this  matter  may  pcrha]«  be  fnid  here,    (.'tuee  are  on  record 

*'o»H)  bddiea  are  satd  to  have  gained   in  weight   by  immersion  in  n  hath,  or 

"y  npomin  lo  a  moist  atmccpbere  during  a  given  period,  in  irhich  no  food 

"*'  drink  waa  taken,  or  to  have  gained  more  llinn  the  weight  of  the  food  or 

'•^ink  taken  ;  the  gain  in  i^uch  coMs  nmitt  hiive  been  due  lo  the  »b«iorption 

**'    Water  by  the  skin.     Direct  ex['eriuie«l>.  however,  throw  doubt  itn  these 

■**lcmenU.  for  ihey  >liow  (lull  under  ordinary  circuiuHlances  such  a  gain  by 

**k«  akin  U  flight,  bt'ing  iipparently  due  to  mere  imbibition  of  water  by  the 

^I>Mr  layen  of  tlie  epidi-mii^ 

AbMrpiioB   of  variouii  »uhilun<^es  taken  place  very  readily  l>y  abraded 

^XirfaoM  wbere  the  dermin  ia  laid   ban-  or  mverMl  only  by  the  lovreM  layers 

^1  ppJdvrmi*,  but  it  has  bevn  drlmtc<l  wh4.-lla-r  substancea  in  atiueous  solution 

I  tw  absorbeil  by  the  *kin  wlieu  ilw  epidi-ini*  in  Intact,  the  e^'idence  on  this 

il  baing  cnntrwdictury.    In  the  mm.-  of  the  okiii  of  the  IVog  an  nbinqrfion 

water  and  of  various  ouloble  sulwtnnccs  rertainir  ljike>  placv.     In  the  ciue 

ikr  *i>uud   htiuiiin  akin  thi're  iin'  ii<i  <i  privri  r^'iitons  nhy  water  currying 

W 


j}62  THK    KLIUINATIOX    OK    WAKTR    I'BUDITCTS, 

MbataticFH  ilifsnlvvfl  in  jl  ibiiuld  iml  piL>4  inuanl  t)inini;li  tlir  cunM-oiMw 
well  as  (he  oiImt  Uycre  iif  ibc  epiiltrrnit^,  the  iiiiiniiiil  m  imta'tnn  ile)ieD>lin; 
tunoDgotlier  thinip,  upon  tho  ooniltlioit  of  tlw  i^kin;  niiii  coinmnu  i'i;i>tv 
tace  Menis  to  ■hoir  that  it  doM.  NcrcKhelcM,  lh«  rMiilts  of  u^'iunl  i-ifirn- 
mciit  are  ooiiflicling.  Some  obwrver'  niuhiMin  that  soluble  tion-volnii't 
ruImuuik*  are  nol  ab«nrbed,  and  that  volatile  Bubstonoes.  aiirh  n*  tivltai. 
wlii4-h  may  be  dere<cted  in  the  Byrtem  after  a  balh  oonlaiitint;  thrw,  ur 
Blaorbed  i)<>l  by  tlie  Hkin.  but  by  the  muouus  ruembrane  of  ilic  nsiiiral/irT 
nrKana,  tli<!  sub^tanoe  luaking  iU  wajr  la  the  latter  by  vnUttilization  fpim  ih 
•urfiwe  of  the  balh.  (>iher«.  again,  have  found  evidence  of  abwirpiloo, 
(■mclnlly  uitb  volatile  subatanoea,  e\'en  when  can  baa  been  taken  lo  aviid 
all  erront ;  «a<l  tbe  };raater  weiji^ht  may  perbapa  be  g^ven  to  tlic«a.  sincv  ihtj 
ftoooid  with  common  ex|>erieiii-e.  The  oonSid  of  experin>cniu]  roMilta.  hot- 
evvr,  nt  Imwi  uhovt  that  ve  do  not  fully  uuderBtaud  the  ounditioDS  osdr 
whioh  nucb  alnorption  lakea  place. 

Th«rv  t*,  luonxirur,  cviitctiof  that  even  soUil  ]iartlcle(t  nti  [ia«:a  throuj^h  m 
inlnct  rkin.  Tbr  tymfihatit»  in  the  »kin  of  u  newboru  infani  have  bwa 
fbumi  cr»wilrd  wilb  ihi-  jiitrti(-li«  nf  tbe  peculiar  fatty  M^-n-tion  wbich  coren 
the  skit)  .11  liirtli ;  aiirl  »»lii]  jinrticlis  mnbed  into  nvi-n  the  hoiiii'I  akiu  niaf. 
especially  whcii  apptii-d  in  a  lully  vphii-ti-,  tu.  r.  y..  in  ihc  well  known  nwr- 
entry  oiiiimml.  lirid  tlii'ir  way  iiiln  thi-  utidi-rlyiii);  lyniphalit-it  The  wamlrr- 
tag  le»eiK-vi<fi  whit-h  um'  nl  timoH  found  antuiig  iIm  epidermic  uells  nay 
jierbaps  taki-  pari  in  tlii*  iranapoit. 

TiiK  MacirAxiMit  or  nit:  Si:i-RKTtow  or  Swb&t. 

\  44S.  In  dealing  with  the  manner  in  which  mrioiis  rircunwtaooM  nlicei 
the  amount  of  §  neat  McreCed  we  mnv.  as  n-C  have  almdr  said,  ronvidirr  llir 
aweat  ha  a  whole  to  be  siipplinl  by  the  sweat-glands  alone.  For  though  il 
Bcnns  uvidcnl  that  some  amount  of  fluid  must  paw  by  simple  ir>ini>mlaliuD 
through  th«  ordinary  epiilermt'  of  the  portions  of  skin  iniervenini;  lietHrrn 
tlfc  motithi  of  the  glands,  yet  on  tlie  whole  il  is  probabte  that  Uw  (■•ninn 
which  m  |us»ea  is  a  small  fraclJon  only  of  the  loial  i|iiantity  mM^rt-i^fl  l>r  ilir 
skin  :  and  direi-t  ex|>eriment  shows  that  even  ihe  Himpte  evap>>raiioii  of  nmrr 
is  miirU  gn-nti-r  frum  ibuse  parts  of  the  Bkiu  in  which  the  glniiiU  at«  ahiio- 
Oant,  than  from  llxve  in  whieh  they  are  scanty.  We  bare  as  yet  no  evideiii* 
that  lh(^  «nl>aiviiUH  glands  vary  in  activity  ;  their  very  pevuliar  form  <if  Mere- 
tion.  if  wf  muy  s)it«k  of  it  as  a  aecretion,  is  not  adapletl  ii>  ouddcn  (■)ia»g'& 
and  nl  all  cventa  we  have  na  yet  no  evidence  that  oircunii'l ami's  nipidk  and 
largely  modify  tlie  amount  uf  M'biini  diicharged  by  h<-atthy  Hehacciaia  i;I"U<l*' 

Tb(?  secreting  atiivjty  of  the  akin,  like  that  of  the  other  glands,  is  usuallv 
aecompanivd  and  aidcil  liy  va>«'ular  dilation.  In  one  of  the  early  expnl' 
nients  on  clivJHion  of  Ihv  cervical  Kynipalhetic,  il  was  observed  tUnt  in  lb* 
case  of  the  horse,  the  vaaculnr  dilation  of  the  fiux^  on  the  side  optmieil  m 
WM  MCumnaoiod  by  iilcrauied  perspiration.  In^leixl,  the  eonneetion  twtWMB 
tlie  stale  of  the  aitaneoua  bloodv«wels  and  [be  amount  of  penpiraiton  m  s 
matter  of  daily  oWrvntion.  When  the  vuewls  of  the  skin  an-  ennaUicUd, 
Ihe  secretion  of  tbu  skin  is  diminisheil :  when  they  are  dilalMl,  It  beenati 
ahundant.  In  this  way,  as  we  shall  tnUT  on  point  out.  tbe  lem|>r<mturv  of 
tbe  hiidy  is  largely  regiilalcil.  When  the  surrounding  atmosplirre  is  warni, 
the  eulanea^us  vcsele  are  ililaleil.  the  aiuonni  of  sweat  seeretvl  ia  inereiued, 
and  the  eonsei|uently  augm<'nic<)  evaporaliun  lemts  to  ciml  down  lliie  body. 
On  tbe  other  hand,  when  lh«  nimospliere  it  cold,  the  eniaDouua  vewela  an 


TUK    UKCHANISM    or   TIIK   SECRETION    OP    SWEAT.      f>63 

cotiMricud,  perajiifatlon  U  scanty,  aud   lees  l»eat  u  loM  to  the  body  by 
vvnporalloii. 

Ihfiiiinlogr  with  tIi«otli<^rw-creiingorgaDsu'hirh  wc  have  Already  tnudied 
l«n<l»  iiH,  liont^vrr,  to  infer  thai  ibrrc  are  f|>ecml  iiervu  (tireu-tly  ipit-eruing 
th«  m-tivity  •>(  tbi-  HiKlorijtapiuii  j^lamU,  imleiieinleiit  of  variation*  in  (lie  viu- 
ciilnr  itiipply.  Anil  not  only  is  lliia  view  nuggttittsl  l>y  many  facut,  kucIi  hh 
thv  ]>r(ifuiw  [K'ntjiiriiiion  of  um  dcttlh  agoiiy,  of  \'nH'>ti»  vriiuw  of  iIimimr,  ami 
uf  itrtnii)  Rivnliil  <tni'>li(tn*,  and  tht  ciiUl  «wediU  (iccurriug  in  plithinit  atid 
other  maladitv,  in  uU  of  wliicb  the  «kiu  iit  unaumic  ral)i«r  than  hypernntviQic, 
but  we  have  direct  cxtH-riinMilal  «vi<iwirt'  of  a  nurvntiK  mechunisin  of 
perspirati^in  as  complete  lu  tliv  vasmuotor  mrt.-haiii^fn. 

If  in  the  cat'  the  peripheral  ttiump  of  thu  divided  sciatic  nerve  be  ■llmu- 
lated  witb  the  int«rnipted  eurrcnt,  anp*  of  sweat  may  readily  be  otwerved 
to  gather  on  the  litiirlf«  tole  of  the  foot  of  that  tiide.  The  sweating  t«  not 
tlue  to  any  incream  of  blood-aupply.  for  it  tnay  l>u  oh«ervvd  when  ihe  cutji- 
iieuus  reaeels  are  thrown  into  a  state  of  c»iW'trictii)n  by  the  stimulus,  or  even 
when  the  aorta  or  crurni  artery  is  clamjH'd  previous  to  the  stimulation,  aud, 
indeed,  may  be  obtained  by  slimuisiiDg  th*  sciatic  nerve  of  a  recently  ampa- 
inted  ]«g.  Mon.'i>ver.  uhen  atropine  has  been  injected,  the  stimulation  pn>- 
duoea  no  sueat.  ihnuKh  vasoniolor  etlc^ts  fi>llow  ai  usual.  The  analogy 
between  the  tiwval -glands  of  the  foot  and  such  a  gland  as  the  auhmaxillary 
i>  in  fact  very  close,  and  we  are  justified  iu  speaking  of  the  sciatic  nerve  as 
containing  secretory  fibres  diatril>ut«d  to  the  sudoriparous  glands  of  the  foot. 
■Similar  results  may  be  obuuned  witli  the  nerves  of  the  f»re  limb.  Ami  in 
uumelvea  a  copious  secretion  of  sweat  may  be  induoed  by  letauisiug  through 
the  flkin  tlw  nerves  of  the  limbs  or  the  faee. 

If  a  cat  in  which  the  setatie  ner\'o  has  been  divided  on  one  side  be  exnosed 
lu  n  high  lempc^ralure  in  a  healed  chamber,  the  limb  tite  nerve  of  which  Iium 
itrta  divided  remains  dry,  while  the  feel  of  the  other  limbs  sweat  fn-elv. 
Thi*  result  showit  ilinc  the  sweating  which  is  caused  by  exposure  of  the  body 
Vt  high  teiD[irratun9t  is  brought  about  by  the  agency  of  the  central  nervous 
«TMt«m,  and  ni>t  by  a  local  action  on  the  sneat-glandH;  fur  the  foot  of  the 
limb  whom'  nervp  ban  Imm  dividtHl  'mi  ei|UaUy  exfiuted  Ui  tlu-  high  li-m|ii'ra- 
turv.  A  high  lt;m|HTature  it  in  true  up  to  a  certain  limit  tncn-iuc^t  the  irrila- 
hility  of  tlw  cpithi'likim  of  tbesweat-glamU  an'I  prnliipoMu  it  to  secrotc,  just 
as  it  proinolvK  action  in  the  enseof  a  muwde  or  imrvc  or  other  forms  of  living 
wibfluncct.  Thus  itimulalion  of  the  sciatic  iu  the  cat  produce*  a  much  more 
abtindani  secrelion  in  a  limb  exposed  to  a  tvm^ivratiire  of  '.i'>^  or  KHnowlwt 
iibove,  (ban  in  one  which  has  been  exposed  to  a  distinctly  lower  leropeniture. 
and  in  u  limb  which  has  liocn  placcfl  in  ice  cold  water  hardly  any  secretion 
at  all  i-au  be  gained ;  htit  apjtarently  men-  riav  oi'  temperature  without  nerve* 
stimulation  will  not  give  rise  to  a  secrvtorv  activiiy  of  the  glan<U.  The 
sweating  e«use<l  by  a  dyspna'tc  condition  of  )>loo<l,  and  such  nupeairs  to  be 
the  sweat  of  the  death  agony,  is  similarly  brought  about  by  ike  agencv  of 
the  central  nervous  system.  When  an  animal  with  the  scijitic  nerve  divided 
III)  one  side  is  made  dyspnuiic,  no  sncHl  apjicars  in  Ihe  hind  limb  uf  that  side, 
though  abundance  is  seen  in  the  other  feel. 

t^wcaling  may  l>e  brought  about  as  a  roflex  act.  Thus  when  tli«  central 
stump  of  the  divided  sciatic  is  Ktimiilalcd  sweating  is  induced  in  the  other 
limbs,  and  in  oursdves  the  introtluction  of  [xingeut  substances  into  the  luoutb 
wilt  frequently  give  rise  to  n  c'>pioiiE  |>ers])i ration  over  the  side  of  the  face. 


1V>  oil  •woMi  mtti  kn  ilio  bklrlcB  wla  <■(  the  (Ml  bill  nirt  •m  unr  iwri  uf  iu»  IkiIj'  ii.ivHwd 


Alth  iMln.    t>~ 
U  oflan  •Man ' 
mdviut  DMo  > 

IHM  '•!  thalioi- 


(■I  ine  ROi  eui  nui  •m  unr  iwri  ur 


I '-'"I.  lU«UII|t 
unit    MiMC 

run  •iniai- 


We  ari^  thus  leml  to  8[ieak  I'f  e«e»l  c«nira>,  ualoouus  tu  llie  viUKirnoiar 
In*,  as  exutiiig  iu  iIk  wuirat  ii«rvoug  stbImd  ;  and  lu  in  (1m?  ouk  n(  % 
ntotor  ceDir<«.  a  dispute  Ittu  arisen  as  to  whether  there  in  a  tlomiDaiu  ■tmi 
ti)  th«  mecliilln  obloaenta  or  whether  »uch  centra  are  nM>r«  gfiicrnlli^  ili*- 
tribtlted  OV«r  the  ytUiAv  nt  the  »pii)ul  oiM. 

It  does  not  ai  |in-9eiit  H|nwttr  cvrLtiin  whelher  the  «n'vHltng  ciiiSMi  br  lia: 
id  onrri^l  oul  li_v  (lin-<'t  m'tioii  of  ihc  )ii-HlF<t  hli>o<l  on  thi;  »wc»t  t.'entres,  v 
br  the  hi(,'hi-r  leinpcnilun-  rtimiilnliiig  the  i>kiii  nni)  so  wmiling  up  aflenBi 
[mpalses  whk'h  I'milLttrv  ih«  efH-el  in  n  rvflrx  manner:  but  in  tb«  case  of 
dyMUKM  at  Iviutt  wi-  may  fairly  mippoH-  ihnt  the  artiun  of  th«  veuous  bi'mi 
H  cbwfljr  if  not  exHii«i\'^ly  on  the  tivrvc  i-rmlrcs.  Some  dnii^s,  such  as  t«i> 
cnrptnr,  which  atum  sweating,  npjienr  to  produce  (heir  effect  chieHy  tiy  i 
Uk-iiI  nclioD  on  thv  ylaDdn.  vinco  the  action  oontiiiue«  after  the  divimoiiof  tiw 
nerves  (thongli  p4lo<.itrpine  ap|]nniilly  hag  as  well  some  ali;>hl  aoiiim  an  tba 
nerve  rentm),  and  the  aDtagonistic  action  of  atropine  is  Hiinilarlv  locil. 
Pi4>rotoxine  and  Mrirbnine  appear  tu  prvKluce  their  sweating  action  cnialljr  if 
iml  exclusively  by  aotio);  on  the  oentral  nervous  syst«m,  while  nivutlne  SMSi 
to  act  birth  centrally  and  ])erii>herally. 

§  449.  The  aweailitirea  for  the  hind  foot  (in  the  eat)  appear  to  louve  tht 
spinal  curd  by  ihe  rouia  uf  the  lower  dorsal  and  up[>er  hiinhar  itvrva,  (mh 
along  the  mmi  mmmunityinlrf  to  lh«  ahiloniinal  ^yn)  put  hell  c,  ami  ihtis  reacb 
(be  cciatie  nerve  Thvv  ihu.i  follow  \'ery  much  the  coutM!  of  thi^  vaeo-cnc- 
strictor  fihrM  uf  the  lower  liiuli;  but  the  jmrticiilur  .ipinal  nerves  ttr  wUcli 
the  ?weat-fihrrv  iMue  from  the  coril  havi-  iioi  yet  been  d<rliiiit<dy  rattled.  asJ 

Iioa^ibly  they  are  in  the  dog  mid  cat  the  Uu't  Ino  nr  tlic  In-it  three  dorml  aai 
Irst  t<To  or  four  lumbar  iierviLV.  .Siniilarly  the  *wca  I -nerves  for  the  f(irf!-fi»t 
leave  the  spinal  cord  by  the  mots  of  it'tov  of  the  upjior  (chteHy  the  foiirtli. 
but  jioisiblv  al«o  thi-  Hfth  and  sixth)  dorsal  nerves,  dom  into  tbu  tbiinu-io 
»ym)Mitbetie,  thence  into  the  ganglion  stdllatuni,  antt  so.  join  the  brnctilal 
plexub  by  the  line  hrnncbes  nnasiiig  from  the  gaoglioii  lo  the  spinal  uervn. 
Tile  course  to  the  lore-loot  t*  fiiiaTly  along  tna  median  and  uliiur  ne: 
r<w]<e<.'tively.  In  the  horse  the  s went -tib res  lor  the  side  of  th«  lace  and  tn 
nig  tliose  for  the  snout  appear  to  run  iu  brauchn  of  the  fifth  Ber%-e  and  i 
in  the  fiirial ;  in  the  latter  animal  at  least  some  of  these  fibre*  reach  the  li 
nervit  from  ihe  cervioil  sympathetic,  but  appturentlv  not  all. 

^444.  Thti  fact  iueuliott»l  above  that  in  the  nurse,  alter  secti<»n  of  iho 
cervical  nympatbelir  nerve  on  one  Hd«  of  the  neck,  profuse  xneatinK  i*  b|iI 
lo  break  out  on  that  nide  of  the  fiiee,  has  SUKgeoted  the  idea  that  lliix  nrrvs 
conveys  inhibitory  immilKS  to  the  sweat-ponds  of  the  head  and  fm^r.  ui>l 
thai  when  it  ii>  dividml  ihc;  Hweal-libra  runuiug  in  the  Hflh  nerve,  having 
iKvihing  lo  coiintcntet  them,  «el  op  sweating.  Uul  it  is  prt>bably  Miflicirai  b 
this  r»H>  to  eupiKM'  that  thr  glands  predUpoced  to  activity  by  the  highf 
lemixTiilura  brought  about  by  the  rteetion  of  the  sympathetic  diluting  tli<> 
bl-roilvessels.  are  mure  easily  exrited  hv  anv  vtiniiiluii  working  njion  tboiu 
through  the  liftb  nerve.  And  though  itc  i<fca  of  a  donhle  nervous  nicohiui- 
ism,  augmenting  and  inhibitory,  guvcnng  the  activity  uf  the  sweut-glonds,  is 
a  tempting  one,  there  aro  at  prssent  no  satisliictory  rcMons  for  adopting  it. 


rvw. 

i 


CHAPTER   I 


THE  MtrTAUOLIO  PR<X.'ESSI&  OF  THE  BODY. 


I 


I 


I 


i  445.  We  have  fnllowe*!  ihe  foml  through  m  obaQgea  in  Ui«  alimentary 
ean>),  nnd  have  seen  it  enter  into  the  Mood,  either  direclly  or  hy  the  iuier- 
tnedinu  cbNniwl  nf  the  lactenlH,  in  the  fonn  of  |)ei>to»e  (or  oihemi^e 
RKMlifitsl  olhuniin  I,  nu^r,  luetic  neiti,  auO  fatf.  accompauieil  liv  rariou*  salu 
uiul  water.  We  have  further  wen  that  tlie  n'anie  }>rciain'ta  wfiivh  leave  the 
iKwly  nrc  urm,  cmrlxinic  ai-iO,  Nih.-i  and  water.  We  )iitve  now  to  Mtenipt  to 
ouBnect  lo^her  the  fixKl  ami  the  wiwUt  proiliictn;  Id  tmvv  »ul  a>  far  a*  we 
■re  able  tlie  ^iij-iou«  »t(!p  hy  which  tlie  one  r»  tramffornwil  inln  the  other. 
Tlicn  remuiiii  ihe  fnriher  tn^k  1<>  ini|iiire  iiilo  the  manner  in  which  the 
eneivj  set  fri-e  in  ihi"  trannfornuilioii  t»  itititri)iiit<'i|  and  madp  dm  of. 

Tne  master  lixeiin  of  tbo  hudv  are  the  inuiicntar  an<l  nervous  ti<«uaf ;  all 
the  irther  timies  may  (m  ngarucd  a*  th<:  •^rvmils  of  these.  An<)  wc  may 
fairly  pmiime  ihnt.  ^)«sidt»  the  digestive  luiil  cxcretorj  tinurn  which  ue 
have  alreiuty  Mudied,  many  mris  of  the  hodv  arc  engaged  either  in  furil^er 
elaborating  the  coinparntivcly  raw  fimd  vrhieli  enlers  the  blood, io  order  ihat 
it  may  l>e  ueimilated  with  the  Icnet  |)oe«ible  labor  by  the  rnaater  (iseiieB,  or 
in  BO  modifyiu);  the  wn^te  ))roducl8  which  arise  from  the  activity  of  the 
master  litwueti  that  they  may  he  removed  from  the  body  as  aiieedily  a»  |his- 
sible.  There  can  be  no  doubt  that  manifold  intermediate  enanges  of  itiis 
kind  do  take  place  in  the  body;  but  our  knowleil^  of  the  matter  is  at 

£r««ent  very  imperfect.  In  a  few  inaianoee  only  can  we  localise  these  mela- 
olic  actioua  and  speak  of  (tl^tiiict  metuhotic  tissues.  In  the  majority  of 
CMM  we  can  only  tnice  out  or  infer  chemical  chanKes,  without  beinj;  able  to 
ny  more  than  tluil  they  do  lake  place  Homewhere ;  and  in  consequence,  {wr- 
hapo  itoinewlutt  luovily,  kjteak  of  them  as  taking  place  id  the  hloutl. 

How  litllT  we  know  ronceniing  the  metaboUiini  of  the  master  titwiies 
tbeinselve*  wiw  :>hown  when  we  wt'rt-  dealing  with  thme  tiMiiKit  in  an  earlier 
part  of  lhii>  wnrk  :  but  »ucc(iH  >n  the  ntndy  of  thew-  ^-nn  hanllv  W  ex]ie4'ti>il 
until  otir  knowledge  '»  iiiemiacd  a*  regard*  llie  chaiigts  winch  the  hliHHl 
und<in:o*3'  before  it  rraehn>  ami  after  it  leave*  tiie  min'clc  or  tin-  iiTrve.  The 
fact  that  a  large  jwrt  I'fthi-alworlHnl  food  is  carried  through  tlm  liver  before 
it  is  thrown  on  the  gcniral  circulation  leads  uk  to  itupiHiM^  that  in  thin  largo 
»r)(an  imporltint  mctab>'lie  proceaiKa  are  carried  on  i  and  obwrvation  with 
exjwrimeDt  confinne  this  view.  Important  nii  the  secnHion  of  bile  may  be 
t)ie  olher  metabolic  functions  of  the  liver  are  of  still  greater  im|K>riitnce; 
and  preparatory  to  the  study  of  these  we  may  now  take  up  the  structure  of 
tlib  orpa. 

TitB  STttlCTrBB  OF   Tn«  LtVKR. 

S  446.  The  liver  i*  a  glan<l.  tlM  conducting  gxirtion  of  wbicli.  the  bi)o-diict 
or  galUdnct.  after  repeated  diviaioD  end*  in  piussnge*  lined  by  svcreticiE 
simctures:  but  the  (vnn|inratirely  rinipU-  arrangement  seen  in  other  glantu 
in  which  the  terminal  ducts  or  diietuli-«  end  in  blind,  tubular  or  flask-shaped 
alveoli  is,  in  the  liter,  mudilH-i)  and  to  a  certain  extent  obscured.     These 


6tfR 


TBS    MKTAHOLIC    PKOtlESSKS  or  TUB   BOOT. 


nKMlilicKtionR  may  be  nseribed  on  (be  oae  banti  lo  t)io  Wt  Ihiil  tho  rvlla  mlicii 
provide  tho  ^eiTt-lina,  beiDK  aim  enf^ged  an  ul<  biivo  jtiM  niiil  iti  tiii|(tirt>nl 
ntcCalxilic  iltititrs,  nrc  ilevclojK^l  init  uf  |)rii[iorli4>H  t>i  thi.*  billiirr  [iifea^, 
nml  on  ibe  other  IihriI  !•■  ihe  fiirt  that  ihi.-  i-nlinnry  viiM-ular  Kiiftjily  <>l'  u 
artery  (he|<ati(-  arloni'  i  en<liiiK  ibruu^'h  (-n|>il)iiri»  in  h  vriii  i  hcjiulit:  veiii),  u 
overHha<iimc<l  by  ihi-  tin-iit  fHirliil  iiyxlriii ;  the  f.'r<iil  ikud  wi<lu  vc-rin  |iurti> 
(liviiJi'iH  iiii<j  vciiiiuri  nijiiUnrii-x,  nmi  tlnw  iirit  ^ihorcd  «p  ngtun  ini'i  lfc» 
befMic  mi),  nbirli  ihitu  >lrnii-«  itx  timin  Mijiply  of  blood  fram  it  rstber  ikas 
ftnm  ihf  much  sDialhT  lii^fiittic  artvry. 

Tb«  «b"ile  iiver,  iiivivli-d  nilli  ii  caimilv  of  wnmvtivc  tiwue  aad  markol 
DU!  inti)  ilM  wTi-ntl  h)lH».  i»  <livitk->l  by  mi{iU  of  conucclive  tiawm-  ■(•.'■■ 
niiriitK-r  i>f  vmall  |inmiir.T  tioils  of  loinonhat  p»lyKi.'iinl  t'unii,  ciillnl  . 
each  hv'mg  in  nin»e  iibout  lb«  tixe  of  a  |>iu'>  heml.    Th«  diftUt)vUrea>  •>(  ■ 

IT*^  W. 


/ 


^:i 


-  U-' 

I'MiRH  tii'firii  K  or  Tax  Ln'Kn. 
irtflii.  unH  II,  li>n  li.bc;  •'.qiiaitmtc  ItilH':  I>. *i4(«li*n.  »iv\  K.  ivn^iu  l»b«  :  7. 
'  t:  <-•■  itnlI-Ma'lilFr;  n.  nun  nvk :  ft.  toim  (arlir:  f.  niunO  IlKiimeiil ;  rf.  utiUlefaM 
ttMmkj  cniniinna  Itciailr  <hiit ; /,  e]r(U«  duct :  p.  ooouMin  bllodiiMi  *.  licfuilo  anory.l 

lobule  fW>ni  ila  nea^bon  depends  >m  the  relative  abundAnce  nf  th«  oM- 
aeciive  ll»ue  wbi«h  aeparateit  them ;  iitid  ibU  in  much  more  i-»ns|)icuiMU  in 
aone  luiiauila  (audi  aa  Itie  )>i^]  ihuii  in  othera   such  aa  the  rnhMl  or  man). 

Tlie  larice  ponnl  vein  [Fin.  l''l]*  ''"^  rava-h  smaller  bile-duct,  ii»d  thvatlll 
•miilli-r  hi-{iattc  artery,  e.ntcrin);  tlif  liver  togi-ther  on  itit  tinder  flurfiK^'  nt  Uw 
porta  lifjHilien,  or  |ini«'  "f  ibi-  liver,  arc  inve*te<l  wilb  a  etin.iidemhlr'  <|ttnnIttT 
of  (NXinwlivn  timiii',  ntrryiitu  aUn  lyin)>balif!<  and  nervM.  nbii^h  is  (.tie' 
tinuotiK  with  ibe  ninnrrtive'lin'iie  covering  of  the  whi>W  liver  and  is  '■»Il>iT 
OliMikn'»  mjwnht.  RM[>idlv  dividing,  the  divinioni'  conliniiinji  to  rgn  l... 
•Idu  hy  aide  in  ibc  Iwdi  of'  (vmnecttve  liniii'  into  which  tiliaum'*  (-a|».i.<:  ,> 
continued,  the  three  vnvelB  iilliniairly  rmrh  (li«  oulMdtt  of  the  serenl 
luhulee,  Ibe  ^cpla  of  connoc-live  liK»xii'  delinin^  ill"  l»lHilca  from  twh  otWr 
bcin);  the  torminalioDH  of  Oli»eotiV  cajmiile  carrring  ihe  tbrM  iOta  of  veSMk 
The  "luall  branches  of  the  |>orlal  voin  thus  rvaebintc  tbo  mrfuiv  <>f  lh» 
tohiile».  and  iiinnin;;  nnd  niia$Ion)<«intf  freelr  belneen  the  lobuleH,  an 
s|ir>ken  of  as  Inlrrlijiiulnr  veiiiM,  (FiK>  Il>^.]  'Hius  each  lobule  is  prorkM, 
at  ilillerent  jxurts  of  its  <rircti  info  ranee,  with  two.  three,  or  more  int«rlnbular 
veins,  ai^iiitiiianied  in  a  manner  uhieh  ne  xhall  devcrilie  by  ilivisi4>ii.i  of  tbr 
bileijiiet  Hi»l  hepatie  artery,  all  beini;  enibeddtil  in  a  i  variable)  ipiantiiy  uf 
eonni'ciivo  liiaiie. 


TUK  STRVCTVRE   OK  TICK   LIVSR. 


5/67 


I 


Eiu.')i  l<ib(il«  Rt  one  |Mrl  of  ite  drcuinlernnc«  rwis  directly,  with  thcr  iutor- 
vciitiim  of  hitnlly  nny  omiMM.-tiv^  lueiie  at  nil,  tipoii  n  imiiaII  v«iil  which  It 
Uol  jMrt  of  ill''  poTtn)  vein,  l>iit  which  when  mic«4  otil  ia  tutiDiI  lo  past  into 
Kiid  r»rfti  tli«  Iiirpatio  win  :  it  is  called  a  uMiAalar  veil).  A  lobule  in  fact, 
thodgh  gvnerally  |iii!ylieilrnl  bk  *«eii  in  sections  at  the  liver,  may  be  con- 
cidsnM  lu  anmenhat  of  llie  furiii  ul'  n  bniail  invrrled  llaak.  lh«  neck  of  which 
rtMe  directly  •>»  n  »tilili)hiilnr  hraiioh  of  \\\v  hvfiaiic  vein,  niitl  U[hiii  the 
]>u)y<;iinal  Ik"!)  ul'  whit-h,  >iirn>uiiiJ«i  by  innre  or  Ick*  c»niiivtiv«  tiMtuc,  abut 
at  variuus  |Hiiiiiii  iiiinrlobiiliir  l>nuichw<  of  lh«  jxirial  vein. 


ino.  vca. 


^^^P  lHw>K*iiH>ii'  tLirtatwumrva  or  Two  HtrATK  lAm'ua. 

^^^^1*  ttft-hnDit  lohulf  M  npNWiiKK)  ullh<lirt»ti»li'1''>lurrtliivutiwlcnilli  therigkt'blDiluno  Uia 

ncitani  ■■*«  tlio  (vwm  (rf  IIw  liiinJ'<balar  vtUi.    (•.  iDwrUibulu  brui«h«a of  the  ^rlNl  i*ln.  A. 

lnlMli>*aiUr  hnnrtx*  of  iha  bapaitc  miM:  •.  lublolialiK  iMii :  f.  otWllarlM  of  Iti*  kobali*.    lb* 

uimr*  lii4lniU  Ihr  (ll>e«tte*i«<  Ihcivumof  IhcUood,    Tlw  llTwr-rtUi «r* <inl]F  t«pr*itnliri  In  oD« 

pan«f  aKfelob<ii*.{ 

§  447.  The  network  of  inlerlot>ulsr  veine  stirrotindinif  (he  cir^tumftirence 
of  n  lolnile  givce  orifcin  to  a  uuudter  of  rather  nide  capillary  vetaeln  which 
run  in  a  radial  direction  toward  the  middle  of  the  lobule;  llie«e  arv  omnitKUiiI 
by  cmm  capillnHtv,  which,  however,  are  shorter  and  leaa  abtiiidaut  than  the 
radial  L-apillnrint,  m  that  the  tno!ih«s  are  elongated,  more  or  lew  re<!tanKiilnr 
spaces  ci>iivrrt:lnu  radially  (owunl  thi-  centre  (if  the  ]i>liul«.  Tnwnrd  lliv 
mi<tdle  of  iIk*  lobolt!  the  cHiiillarii-H  mer^tt  into  a  Nin;;le  v«iii.  calle<t  an  intra- 
lobnlnr  VL-in,  which,  running  ilnwn  the  iii-ck  <il'  the  lIiLak.  and  receiving  the 
mpitlariefl  of  the  ucck  uh  it  guc»,  lalU  into  the  sublobutar  vein  kpokeii  of 
above. 

Tlie  elongated  menhc*  nf  this  capillary  network  oinvprKirij!:  rapidiv  toward 
Uie  intralobular  vein  nt  it*  lic^'innin^  in  ihi^  Imdy  i>f  (lii>  llni>k-like  lofiulo  and 
lU  It  b  cvnliniied  alon^;  the  ni-ck  of  the  tliuk.  are  (nviipiiil  hy  n'lniiToly  lur^ 
ivdripnal  nui-lealed  cells,  which  wc ithall  prtw^iitly  di-^rrilK-  in diiaii  us  hryilie 
tftlf:  The  wiillh  of  a  mesti  is  ^fciicrally  such  m  V"  admit  unc  or  Ino  ccIIh 
ubrvunl.hut  its  leuuth  adniiiH  tv\-ernl  celb:  henne  thu  cvlU  are  urranj^cd  in 
narmw.  radiating;,  broken  columns  converging  toward  the  middle  of  the 
lubiile. 

The  ndtimn*  of  t-ellR  and  the  meebwork  of  capillaries  practically  con- 
BtilUle  iIm'  whole  of  the  lobule,  fur  batidea  a  mininiuni  of  connective  timiie 
forming  an  advNititia  to  the  i-apillariee,  certain  lymphatic  |Mu«iig««  atl^irded 
by  thid  advontitia.  and  exlreniely  minute  paang«8  which  form  the  bejfinniiiga 


M8 


TnE   VKTAUOMC    PtlOCttS%t»  Of  THE    SOI>r. 


of  th«  bile-ducU,  anil  of  wliich  wl>  shall  Hpeak  lawr  on,  uothiiig  elw  e 
nrnenU  The  lahuU  in  Ikct  consists  Urtt  of  a  vaacular  tmaev/ttrV.  of  c*pil' 
Urtee,  which,  (akinj;  origin  at  the  surfnoo  of  ihe  lobiile  from  the  intertobukr 

Smrlal  veiiU«U,  are  dtspooed  in  a  network  with  mwbw  elon^tnl  in  a  radial 
linctioD,  and  ooiiTef^e  at  the  oeotra  of  the  lobule  to  form  the  intralobiilu 
v«liiliH  falltuit  iuio  ihe  sublobular  (hepatic)  vein,  and  eevondly  of  raduiinf 
oohimna  of  n-Ux  lilHoj^  uf>  the  ra<liiiuti);  meabed  u(  thb  vaa<^iilar  ntlwark. 
HtiicR  in  aaectiiiu  of  a  hardened  and  |ire|M»«<l  uninjected  liver,  !n  wUdi 
iIm)  hloodvtsw)*  unj  lar^lj  emptied,  (he  arv«M  of  the  riectiom  of  lohalra  iif* 
indicated  hv  Ihu  radicidlv  o'livcrKing  uolumnx  of  i;clU,  and  fac<^>r-' 
the  animal  cmploywil  nrr  more  or  lew  diatiiK'tlv  marked  o*il  by  thr  -  j 
coiinoctivr  ti»iio.  in  which  may  be  aeen  here  lunl  (here  the  liiminn  <>l  lii' 
larger  interlobular  veinx.  In  h>hu1m  in  whitrh  the  M^tOD  lirix  |ini««l 
Ibrou^'h  thf  miildlc  of  ihp  lobulfi,  tli«  lunuin  of  ihi-  orntral  inlmlobtilar  nio 
will  also  lie  vinihle;  hut  iitl«o  tbu  soOion  tiill  eiit  n  tobuln  m  HUparlidally  ai 
|o  miss  llie  inlrnlobular  vein  allogiether;  anil  it  ts  only  whci)  the  eei-tion 
happena  (o  paw  throu)»h  the  middio  of  the  h>btde  in  the  plane  of  t)ie  lonj 
axis  of  the  flask,  that  the  origin  of  the  intralobular  vein  in  the  midille  nl 
the  body  of  the  flwik  and  iu  couiw  along  the  neck  to  tJra  euhlobular  vein  a 
diMplarod. 

S448.  If  ihe  section  be  extensive  enouKh  there  mar  he  seen  here  and  ihtn 
■H-clioiM  of  the  portal  vein,  hejmic  arterv,  and  bile-duct  runninj;  in  iiliiwoti'i 
oiipaule.  St-iti'iiiv  or  the  branchea  of  tlie  hejtatie  vein  Ibrnied  iiy  the  union 
of  nuhlohular  vi-iii.->  may  alao  be  keen.  Theae  may  be  reco^ued  by  iht 
abaonoe  or  by  the  extrcnw  iifHniititMt  «f  any  i-oniiet-lire-tiiMie  wrapping  tn 
th«  win,  evftn  in  the  <:nM  of  thi*  larger  bntni^ben.  The  widl  of  the  vvin.  l'>», 
ifl  very  ihiu,  and  ronnisU  of  hur<lly  more  tluiu  th<-  Uiuiea  intinia  nvitiiig  on  * 
thin  conuec[ivc-li"Bue  biuia.  moiuHilar  libro*  biriujj  .10  verj-  wfuniy  (liar  ihf 
tunica  media  may  be  mid  to  bi'  ab«cnl. 

The  wall*  of  the  |H'rtnl  vein,  on  the  contrary,  are  lliick  and  mu^cnUr; 
tlie  trunk  is  more  abundantly  siippli^vl  with  muieulnr  librai  than  any  xliitr 
Tein  in  tlve  bodv  :  and  lbt>  liriinche«  wiihin  the  liver  aru,  in  diinini^hui)! 
degree,  thick  ami  muKutar.  This  in  intelligible  whco  it  i«  remembered  thai 
the  bloud  ia  distribiiied  into  capillaries  from  Ihe  portal  vein  »t  fhim  u 
artery ;  and  iudeed  it  has  beeii  mRintniiMd  that  (he  portal  vein  is  snhjei'i  t>i 
rhyllimic  contractiona  of  its  walls,  as  if  to  anist  in  the  iMumgo  onward  o{ 
the  blood.  Neither  in  the  trunk  nor  in  ibe  branohea  are  any  valvoa  prewM. 
and  ihuae  are  abo  ab»enl  from  the  branches  of  the  hepatic  vein, 

The  branches  of  the  hepatic  artery  are  ^'ery  much  smaller  than  the 
bruichea  of  the  jiortal  rein,  and  even  much  smaller  than  the  hranehea  uf 
tha  jKirtal  vein,  and  even  much  Bnialler  than  the  branches  of  tht<  ltili-dLi<:i 
io  mmpaDy  with  which  they  run.  An  they  proceed  in  their  courw  tlii^y 
HUptilv  iho  wall*  of  the  {H>rtal  vein*  and  of  the  bile-ducta  and  the  tmb.-ttaiiiie 
of  tiilaton'ii  oJipHite,  and  eventually  dtwhari;e  their  blood  into  the  portal 
WdIoIa.  It  hat  bei-n  mainiiiiued  thai  •ome  of  the  finer  braui^liea  run 
directiv  into  the  vawulnr  me«hwork  of  the  marginal  parta  of  the  Inbulo, 
but  ihU  is  dispuu^, 

$  449.  '/'Ar  hitf->lu'*t.  Th<!  larj^r  bilo-durtd,  namely,  the  bi'pMlic  duet 
leading  from  Ihc  lii'er.  ihc  cyiittc  duct  Inoiltog  from  tlie  gallbladder.  aoJ 
the  common  bile-^ioct  firuM-d  by  the  junction  of  the  two,  have  the  onlinory 
eharaclers  of  large  tfbind-ductii.  An  epithelium  of  o<himnar  eelU  runta  Mi 
n  connective-tisHiv  Dons,  and  ■»>  constitute*!  a  mucous  menibranu;  ifaia  i» 
supported  by  a  well-dox-elonrd  nuiscular  cmt,  coitsisiing  of  a  thicker  inter  __ 
layer  of  circularly  dispoteil.  and  a  Ihiiiner  external  layer  of  lonijicudiual^ 
tIiB|Ksed,  plain  muscular  fibres  mixetl  up  with  a  gooil  deal  of  cuDueoti' 


THS  STRCCTUKB   OP  TriS   I.ITEEH. 


689 


» 


» 


tiM(i«.  Tli«  walls  of  ibe  /aD-blddder  bave  «weniinllT  Ibe  same  structure. 
Botli  tbe  Ksll-bladder  aud  tbe  ducU  are  capable  uf  oair.vina;  oul  perietaltie 
coDtrnciinDB  uf  tlieir  walla,  by  the  help  of  which  uhen  aee^d  (i  25:i)  tbe 
ramd  flow  of  bile  luui  Ihe  inleoUne  u«e<curei1. 

Tbe  bile-duclA  within  (he  liver  ar«  alvu  niiuitarK-  vonilituled.  iheir  walla, 
of  Gouree,  beoontiug  ibiaiter  aiid  lew  mtitouiar  im  the  tube*  flimiuUb  i»  »\t/e, 
wit)  the  epilheliunt  becoming  eiibiottl  rather  than  columnBr.  A  character- 
Utic  fcttture  uf  the  «iimller  bil^  iliiuls  tt.«  they  run  ia  OliaMw's  oaj»ule  U  that, 
unlike  tiie  ducta  of  miwl  ^lurxl*.  Lhcy  firm  froiuutil  aiKuHomailCd. 

Tbe  epilheliiim  of  the  •Iik'Ii'  c-miniii:)  timDy  gublcC-n^lh.  niid  in  tl»e  u'alU 
of  the  luriccr  iliicL'>  aihI  of  Uic  gBll-blndilcr  I'liinll  miio»ii:i  gliiniU  am  jin^Mnl; 
a»d  ill  tbe  smaller  ducts  lh«c  arc  apt  lo  be  «inip]iticd  intf>  mere  pit*  or  ahoH 
(li-|>r«)Hion9i  of  tbe  niucoii*  lucniliriinc. 

riic  ■itiall  tormiiial  niiii#tomu«irig  hili--diicti!.  uow  coiisiHiiig  of  hardly 
more  than  a  cubical  oplthcliuin  n-st^iig  on  a  connective- 1 twuc  biui*.  may  Im 
Intceil  to  various  jiointMof  the  ninrgin  of  a  lohiilc,  and  tborv  went  to  end 
iU>rupt)y.  Juet  before  a  bite-duct  thus  ends  or  teems  to  end,  tbe  cubical  coll* 
l>«e<>iDe  much  Hatier.  tbe  lumen  of  the  tube,  however,  remaining  narrow; 
■ud  tlieu  Ihe  end  of  tbe  tube  seems  blocked  up  with  the  hepatic  cellit  of  tbe 
lobule^  To  uoderataod.  however,  tbe  nature  of  (hie  jieculiar  ending,  we  muu 
returp  lo  tbe  bepalic  ceiW. 

S  4S0.  The  hepatic  cells  lillini;  up  the  meeheaof  the  Taacular  network  of 
a  lobule  are  relatively  lar^e  (20  to  W  h  in  diameter  in  man)  polygonal  or 
roughly  cubical  oella.  Esoh  contains  a  relatively  Inrj^e  ruundeci  nucteoa, 
and  in  not  a  few  celU  two  nuclei  may  be  seen.  Kach  cell  is  parity  in  con- 
tact with  iu  neighbor*,  and  imrtly  abuta  on  a  bloodvessel ;  for  there  U  prob- 
ablr  not  a  cell  in  a  lobule  which  is  not  in  touch,  for  some  part  of  iu  suriiice, 
with  one  or  more  bloo<)venela.  Where  tbe  surfaces  of  two  eells  mee4,  Iheir 
BubaUncee  are  Id  contact,  that  in  to  mv,  thcK  is  no  centeul  •ulniance  between 
tliem,  iuk)  the  external  layer  uf  cell  MiilMtanci-.  lhou|ch  it  may  at  tii»«s  nt  all 
evenUi  diflcr  fmm  the  more  iiilcnial  cell  Kulmttimre,  i»  nut  dillervutiateil  into 
a  distinct  meiubmuc  or  culicli-.  Wlirre  ihr  surface  of  a  cell  nbuts  i>n  a 
bliiuiIvnOTid  the  substancn  of  the  (^:I1  i*  gcnerallv  Miparnled  from  the  wall  of 
tbe  vuocl  by  a  lympli-spacw,  which  in  connM-lvd  with  tbe  hepatic  lymphatic 
veM^. 

Tlie  cell  subatance  ilsc-lf.  as  might  be uxpcctud  from  what  has  been  already 
ur^ed  CDDoerning  the  melaboli«iD  going  uo  in  the  liver,  privcnto  u|)|>e<inin<!C« 
wbicb  differ  very  widely  according  to  circum«tanocs.  Suniotinics  ihv  cell 
eiilwtanco  appears  denee,  compact,  and  of  fairly  unilhrni  texture,  though 
more  or  less  granular;  the  whole  coll  is  then  of  ralntively  small  bulk. 
8o4netinK«  tbe  cell  suLetance  appears  large  ami  bulky,  owing  Ui  iU  being 
lareely  loaded  with  a  subAance  BtaiuiDg  red-biuwu  wiib  iodine,  nhicb  we 
slinll  study  in  detail  preeentlf,  called  glycogen.  When  such  a  ct.>ll  i*  har- 
dened and  Uw  glycogen  diasolved  out,  the  cell  aubetanee  apjtears  to  be  so 
completely  riddled  with  vacuolee  as  to  be  reduced  to  a  mere  shell,  surround- 
ing a  loon  irr^ular  nctwortt  except  imtuedialely  around  tbe  nucleus,  where 
it  is  more  solid.  But  it  will  be  beat  to  reserve  tbe  discussion  of  these 
changea  in  tbe  (xlU  uutil  we  have  studied  to  some  extent  the  metabolic 
ebaagea  which  take  pluire  in  tlie  liver.  We  may  iu1<l,  however,  tliat  verv 
frequently,  eipeciatly  iu  certain  animals,  the  hejiatic  cell  is  crowded  with  od 
globules  of  variouH  »iaai;  ihwe  are  at  ti wen  no  numerous  as  completely  to 
llide  the  nuclcu*.  which  oannot  be  seen  until  the  fat  bai  been  removed. 

§  451.  Where  tbe  side*  of  two  henatic  cells  are  in  contact,  careful  exami- 
nation with  high  powera  of  the  MncriMm|)«  will  «IWn  reveal,  at  about  tbe 
middle  of  tbe  liue  of  junction  uf  the  two  «id«f,  n  minute  hole,  a  tentli  or 


Vkockssbs  or  TiiK  uuur. 


Kiw  i>f  iW  ilijiiitcter  ot*  Ihr  evil,  wliich,  iirmnlitig  (o  wtme  nbeervvra,  (■  Itw4 
with  H  (]elicat«  nitirtibr  lining.  Thin  )i<>li>  io  thv  wflliMi  nf  n  ntinuU'  OUmI 
pnj^iiii;  Iwtweeo  the  iwn  rrlU  in  tlx*  mi<l<lk  lin<t  of  l)>«'ir  nf>iM)M><l  ■iirram 
A  ino'kl  of  it  miglii  Iw  mmlc  <>n  twi>  niiiitll  bl<>ck»  of  dinlk  by  cuuinsi 
narmw  wnn  cJn-ulnr  ertxivc  <t»wii  ih«  ini'MIr  of  one  Kids  nf  eaoli  bitick,  aal 
Utcfi  biioffii))^  thvMi  ino  niIm  iiil't  lu-ninili.-  t'Diiuicl. 

We  Iiiiv«  nlrenily  mttl  lii  4171  ihnt  iho  bltiu  M>l<iring  n»ll«>r,  RodiuM 
Bulitltiii<li;[<>luti.',  whw>  iiijfrtw)  itiln  (lip  mne  i«  uxen^-)!  by  tlw'  livrr  M  i«tI1 
M  b V  iIm!  ItKliiry.  If  thi-  iniiiiial  )><■  kttkil  ut  nit  «)>|im|>riiii<-  iirii«  atttr  ihv 
injedjoii  itml  iIh-  livrr  litirHoiii-il  atxl  prvpiiroil,  m«Uoim  uf  llti-  liv«r  will,  n 
sutxvKifii I  •jx-cliiti-iiji.  n>vptil  a  c\-(v  nclnork  of  blue  tJiin  linm  Irnvrnliic 
the  wh'ili-  or  fiii-h  "f  lliv  lolKiIcfl,  The  merit»  of  lli«  D«t«<>rk  nrc  df  nhmit 
the  widlti  of  n  hi'iuitic  cell :  nwl  upua  exiuniiuUion  U  nrill  br  foiiml  thm  ik* 
etiifitjr  riiiniilc  li'ik«,  jiiot  ^pukeu  of  lu  seeii  in  the  HMrtioiu  of  «  liver  profMr*^ 
in  the  unliiinrv  nny.  nra  ik><>'  Iille>)  with  lh«  bhie  pi);n>enl;  tlic  miiiiiti'  cnnal 
ftf  M'hii-li  i-iic-ti  bul«  te  u  section  is  n  part  of  a  network  of  niinuto. 
|»a»iii^  lii-(wt«D  the  cells  in  varioiiH  ditwiionb  all  ov«r  the  lobule,  i 
»my  hi-  inii-nl  to  the  Mnv  t-f  thi-  lohnle,  ami  ut  VHrious  iMiDla  of  Lba  n 
the  hliir  lin«  between  iliv  liei>aii<-  oviln  will  l>e  »een  lo  be  oMitindolU,  '■ 
Ikrg^r  •ttianlity  «if  llie  Miae  blin-  miih'niil  occu|>riuit  the  lniDe«i  of  ou«  ol'  tiir 
tuintilc  hjle-iluda  m  it  atHiUi  uii  itic  niniyin  of  tti«  lobule.  TItese  miiinU' 
cnniiU  Nii'.  Iliervfore,  ciintinuoUM  nllh  the  bile-ttiieU;  th«y  are  the  tcrminif 
liaiiiK  of  ihi<  bile-<luna  within  the  )»l>ul<v.  nod  imlM^  mvi  ooly  may  thry  U 
injiK-iol  •liirini;  life  with  :-H)iitni  uttidiinili^iliili-,  IhiI  injci'tiuo  maivrini  niny, 
though  with  <lilfii-ulty,  Ih-  drivi'n  inti>  th<<ni  biu-kwanl  nion;;  llie  bilu-ducu. 
TIh'v  aiv  s|H>kMi  tiC  iM  hilr  ciiiilt'trif* ;  tbv  naini-,  )>i-rb)ip<.  is  put  a  ittf 
dmirnbJe  i>i)i*.  btit  it  ha*  brrn  eciienilly  ndii|>iiHl. 

We  Miid  juKt  WW  thkt  ouch  he|iiitic  wll  toiichwl  u  MwMlvnxel  by  «  l«Bl 
(llie  of  ilii  viirAuHii.  wv  nmy  now  aild  ihiit  eiicb  hi.-|iiilic  cell  ban  at  leMt  am 
Bide,  aitd  ^■ni-tnlly  mora  ihnii  one  aide,  gro>iTed  to  fonn  a  Uile  Mpillwy. 
■fiiire  eiicb  nidv  thus  gruuve<l  is  in  coaliKt  wilb  ihe  corrMpowlin);  aloo  of* 
neiKhlMinng  irll.  it  <-iiiinot  run  alon^ide  a  bloiHtveswI.  Hence,  betwvOR  ■ 
bile  i-ii|>i]liiry  and  a  bloodvewel  BOme  umuuni  of  eel!  sulntaniv  in  nlwnn 
inter|Hu>it.  The  relative  jxintioa  of  the  bile  cnpillarics  itnd  l>I<MidvnMli 
may  ho  illiislraleil  by  takinv  a  cube  and  Ainverlin^'  it  into  u  (loly^nu  by 
Iwvrllint;  diiuu  the  an|;leit  of  tlie  itidea.  leaviuj;  in  ilie  Knil  instance  tiinw  in 
tbe  npiier  and  loner  fucot  untou^^bed.  The  bloodveaoeb  mny  then  lie  etiif 
•IdMxsl  as  niuninj;  <luwu  the  bev«lted  edge*,  while  bile  i'ai>tllarim  run  aUng 
the  middle  lints  «f  the  *idM.  Two  vuch  cutm  placed  end  tu  ind  rmeIii 
rc|tment  a  thiu  •mall  iidet  of  celU  in  one  of  the  smaller  sbortcr  radial 
omwIhii  of  the  VAM-ular  network:  ni>d  tlwo  the  anfl«  of  the  upper  and 
h>wcr  fitce  of  the  ctnjuiiim)  mbe«  woul<l  have  ubo  tn  lie  berdleil  for  iho 
craai-barn  of  ihu  neiaork.  Frocjiiontly,  no  we  Imto  aaid,  Uie  cells  lie  lw<> 
abreaal  in  a  rnenb  of  the  vawular  neiwork;  then,  (if  OMirae,  in  the  model 
the  ancles  or  the  iiurf»cc«  in  contnct  wixild  not  bnvc  lo  be  bevtdle<l,  nince  im 
bluoilvtOMk  run  between  tlicm.     If  la^wral  ituch  bevollol  niVirt  wcrw  huill 

at)  into  ft  model,  it  «»tild  be  Bcen  that  the  ncttwork  of  bil iiiillimw  runs 

nhw^'  ttw-  niiildie  of  the  surfacw  betwi-en  itw  bluodvi-^-l".  forming  n.wUI 
iioiiilii  wlMrti-  wlls  are  in  muilact  with  each  other  hy  ihcir  Kiirfiicfu.  aod 
Wvin;*  «oiiie  amount  of  cell  substaiit-e  between  the  l>ile  c«|iillary  and  tba 
blo<Nlv<i>«i-U.  Tliid  at  leatl  tuay  he  taken  ne  (he  typical  arran^'nu-iit.  when 
the  network  of  liile  i-apillariea  ia  moel  roniptex.  Itni  ninny  pclU  have  thi* 
lumen  of  a  title  eaptllnry  on  une  side  only  ;  and  oivasionally  a  Ink-  cafullury 
if  H<en  ill  section  ul  the  (Mint  of  cnDvermenee  of  three  «elU  nft«r  the  fa#Uian 
of  nil  ordinary  nlwulua. 


tVtieii  a  lnl«  iliitt  Hliiirn  »ii  tho  nmr^ii  of  a  li>bul«  lli«  luineu.  m  «ra  h«v« 
jireviodsly  mM.  wci-nut  wiiMi'iily  to  ■Niitifl  li>  iiii  end.  The  flattrtipd  cells 
iiiiiiiit  iht  (lurlule  nr  ((-rniinnl  iMirtion  of  tl)i<  duct  »ii<Menly  L'lmn^'C  iiilD 
lantt^  h«|iiUic  Ci^)l»,  iiiatviiiMl  ivlU  at  thv  li>liidc.  ultii-h  n(i)H-i)i'  l»  He  mm- 
pleti^ly  ill  miiliuil  wttli  mch  ollii-r  and  to  liloi-k  u[>  ititt  diii-tuk'.  ]tul  nliui;; 
iIh?  Htilm  111*  iIm-h!  iiiiiri;iiiiit  rvlls  as  nf  all  llif  <'lhcr  i'l-11ii  (if  tlit'  I<il)ii1«  run 
bilt  ciijiiiliirif^.  mid  ihew  are  coDtlnumie  on  ihr  i>pi'  »ide  with  tin-  luiiii-ii  of 
itii-  durtul«.  tind  on  lh«  otlier  linnd  wiih  ihe  ndwnrli  of  iW  hil<-  oa|>illflrt^ 
iravi-niri^  iJie  lubide.  In  ihc  ducdile  ilwtf  the  liimcii  n  »)llt:h^  i-yliudricul, 
and  nf  wRiv  HKc,  it  suddeolv  divides  into  much  umaDcr  ]«i>iNi)rn<.  ami  llie 
C«ll»  lining;  three  tiriialler  braiicltin];  iinuMKra  are  uo  longer  frimply  t-)i  it  helium 
eelli"  linitiK  a  diirt.  but  i-»nt^lex  hejMiic  cella. 

It  wotild  np{iear  tl>en  l)ial  ufl«r  nil  the  beimtic  cells  nra  rmlly  ecllti  lining 
tW  Irrminsl  secntting  portiotiit  of  the  dticl,  liniiitf  we  might  nlmiH>t  Miy  lliv 
alvi^di,  but  oMiii;t  on  thu  oiii!  band  to  the  ilistribution  »f  bliHidvciwI*.  w> 
(UHiri-Nt  frnm  that  which  obtains  in  the  ah'enli  of  otiter  glaiidti.  un<l  <in  thr 
olbvr  hand  to  nioilitimlionj  of  the  heiMilic  celtn.  due  to  their  being  rngaj-id 
in  other  ruiirlion*  (liun  that  of  >fcreliu){  bllc,  th«  relations  of  the  cl-IIs  to  [hi- 
lumian  of  ibualvmdi  li  jivculiar. 


Sn-iiMc  or  Litxa  of  Faui.    ILixuliiv.i 
TW  ilpi;*  hkum  lb*  iiihiiUr  •inirinr*  »r  ihu  Itivr.    At  •■  ■  liihule  h  trtn  Ib  Iniinmr.  ol  h  In 
lonflrmniinl  •Ritisi;  '.  Imncn  i.t  lobiilr;  Ihv  Ur«  HMItMI  Kfa  olnlar  »o«.kiiil  IWniUiBhuii  nti 
InnMtoMri't  imacM iiuiut* ;  lb«uq|«riDn*«H(ibM)'OD<ii|ilc>lli]r  tl;ai«<n. 

S  488.  Ill  tl>e  lower  anlmnla  lb«  i>lnieltir«  uf  the  limr  in  vimfdiT,  and  a 
bm-f 'liiwriiHtiHi  of  tlH-  frog'ji  Hvit  may  (lerbiipt  a«-i»t  tonanl  tht:  oumjirc- 
h4-iMon  of  ihi-  nature  of  tla-  inamniiilian  liv<T.  Tim  Hvtr  of  a  frof:  lu  wen 
ill  a  •i-^'tioti  apiiean  l«  1>C  aiadc  up  of  a  niiintHT  of  Inbulcii.  which  ntpi'alcdiy 
n^A  tinK  bmiirh  but  ahu)  nnii«torii<w<-  I'Kig.  Hi-'l).  and  iimmn;  which  run  tho 
ca|itllart-  bhioilvcwi-ls  uniting;  tbe  htnnchts  of  lh«  [Hirfal  nilh  thos-  of  the 
be|uUic  vein.     Thwru  ia  no  very  obvious  ilivisiun  into  lobules  ;  indeed,  la  a* 


^ 


fi72 


THK    HETABOLIC   ]>ROCES9BS  OF  TUK    HOUV. 


6i.-c-lu>n  uf  xninll  iiro«  ihv  luliultv  appear  to  nui  irrcgiilitrly :  iinviTttiflni 
tWy  Itavu  n  ilrfinicv  arrnngdniiutit  nround  tbu  limmJMV  of  iIm-  licpHLli'  vein. 
Binh  !»iii;iiiiiliu3l  ixttA  tranavene  soctions  of  ouo  of  ibMc  tubtilibi  nlitiw  tltU 
it  i«  limxi  «-!tli  largt^  ircdgo-Hbapetl  oelU.  leaving  a  very  narn>w.  nlmiMt  litmir 
but  still  (li«(inct  luitieD.  AixhidH  th«  tubule  is  diamweil  n  nelwurlc  nf  irapil- 
larws,  an<l,  ns  in  the  alveolui  of  an  nrdinarr  glnnd,  tbe  bloodvcmol  is  wpa- 
mtod  from  the  lumeo  of  the  tubule  by  the  thicknees  of  an  euiire  cell.  Eadi 
coll  pomaMS  a  n»uD<I«()  nucleus  which  I'kh  Id  the  outer  part  of  ib«  cell  DBBtvr 
to  tbe  bloodvewel  than  to  ibe  lurae'n ;  and  we  mar  mention  here,  though  w« 
aball  return  to  the  ixiinl  later  no,  that  th«  («li  tiuhstanee  <t>niains  a  iiuoiber 
of  gmnules  which  :ii>e  sDmelimea  scattered  thruui;h<>tU  tliv  cell  and  sMneUnM* 
Aggregated  near  tbe  lumen.  The  lve|Nitic  cell  of  Uie  fr<>)c  rej«atd  in  fact  tbe 
main  cbaravtere  <>f  tbe  »ecretini;  <!ell  of  an  ordinarv  Kland,  of  a  iKini-n-aitc 
wll  for  example.  The  tubules,  nwrwuer.  whi-n  tniee<i  are  found  Ut  cud  iu 
ducts,  the  (UKireltD;;)  hojiatic  cAU  xuddi'iily  chiuiiipn);  to  onlnoal  aud  tlmi  to 
ooluoinar  (condintinu;.)  c-1Ih,  which  in  thi-  larger  iliieu  bear  cjlia.  In  o[h«r 
words,  tbe  be|Milie  lul>uU-9  <>f  the  frn^  un,-  alviiili,  diDvring  from  tlw'  alveoli 
of  an  ordinary  utaml,  in  that  tltey  rV[)«at<iUy  aDa>l<>m(MC  lu'  well  a>  bmiicb, 
nnd  in  dial  lh«lum«n  w  very  narrow  and,  vince  it  al«u  braucliua  aud  ansMo- 
ouweti,  furmH  a  iiotwork  of  lin«  iwimgM. 

From  a  liver  ttuch  a>  (hat  of  the  frog  tbe  change  to  the  arrang»m«nt  of 
tbe  mammalian  liver  is  une  of  degree  only.  The  branching  and  aiuulorDoenBg 
of  tho  inbulfti  is  still  mufe  frequent  and  complete  and  the  lamina  of  the 
tulmlcH  utilt  tuirrower,  so  much  m  that  each  cell,  ft>  it  were.takcs  |inrt  in  eer- 
eral  mbuW,  nnd  tbe  network  of  the  lamina  or  bile  capillaries  is  so  oloee  set 
that  lh(!  mf«itv«  are  of  about  the  aanic  vidth  as  tbe  hcjintic  cells.  The  blood- 
TBWcb',  moreover,  are  more  abundant,  and  by  the  estabtiBbiuent  of  an  arrange- 
nent  whereby  inter-lubular  i' portal)  veinlel«  send  captllariw  lo  i.'ou\'er)[e 
ladially  to  an  intra-lobuliir  I'hepaiic)  veinlet,  the  bepatie  eu1»tanee,  instead 
of  as  ID  the  froff  beinjj  ilitlribuled  more  or  leu  uniformly,  a  dividod  into  a 
imiplKtr  of  small  areas,  the  hejwiic  lobulee, 

$  M3.  Ooncemio);  tlie  iiervee  uf  tbe  liver  we  »haU  aay  what  there  is  to  be 
mid  when  we  come  to  cumnder  tbe  action  uf  tbe  ucrvoua  ty»leta  o»  tbv 
bepatie  metaUilie  pritcvs»t«. 

With  lymi>halii.«  the  liver  la  w«ll  provid^il.  Within  tlwt  lobule  lymph- 
spBC4«  exist  betwtvn  the  wallH  uf  the  vascular  itelwurk  and  the  imt«r  margin* 
of  tin*  bupatii-  r^rlln.  and  at  the  Hn'u nifercnci^  of  tli«  lnhtile  thcMO  SpaOM  oMil 
into  definite  lyuiphatiir  vowel*  which  run  in  the  conntvtivu  liwae  Mparatin^ 
Iho  h^mlcH  and  furming  the  Itcginning*  of  (ilimon'fi  cafMulc.  The  lymplinlic 
vcMttls  lying  near  the  nn|>«r  surface  of  the  liver  find  (heir  way  along  the 
linincute  ul  the  liver  to  (lie  tlioiaric  lymphalii«,  thwc  ooniiog  from  tbe  right 
■KM  iMUMniig  f )  the  right  Ivmphatic  trunk  :  all  the  rest  of  the  lyntphaticB  pass 
onl  along  tnc  porta)  canal  and  fall  into  the  abdominal  thoracic  tluoL 

From  (be  details  given  nhnve  ne  may  infer  (hat  ihc  liver  is  in  part  an 
u^linary  secreting  gland.  The  hcpulic  cells  living  on  tbe  blond  brought  In 
ihcm  manulacture  bile,  which  they  diKchsr),'e  into  the  nnri-ow  luniina  of  tlw 
minute  bile  capillaries,  from  nhcnee  it  llr>ws  outside  the  lobule  alon;;  tbe  more 
open  paawgcs  of  the  bile-ducts.     But  the  blood -supply  is  not  only  out  of  all 

r portion  to  the  demands  ot  mere  becrelorr  work,  but  also  is  peculiar  in  sn 
that  the  blood  roaches  the  liver  laden  with  many  of  the  products  of  dijien- 
(ioii.  This  would  lead  us  to  infer  that  tite  hepatic  cells  are,  as  we  have 
already  suggeeted,  al»i  lar^rly  enicn^l  in  Htthdrawin^c  nulMaucc*  from  the 
portal  blood,  not  for  tbe  |>ur|ioie  of  Bimjdy  furtuing  bile,  but  in  ordrr  that 
other  subatunces,  or  the  same  subtttanoes  more  or  lets  altered  should  be  ailded 


or  01. 


678 


I 


I 


I 
I 

I 


I 


to  th^  liln^d  III'  the  tiepaiic  v^iii  hikI  >»•  iliMnliutiHl  (lir-iii^lmtit  (lie  bcMlr  Tor 
tli«  bulj-'s  Miv.  Aini  we  hiivc  exjieriuiciUiil  cviil'ini'  thiit  eiich  n  work  is 
curried  oa. 

Tub  HufnmY  or  Glycooxn. 

S  4M,  If  the  livor  »(  n  on-ll-feil  miininl  be  irmovol  inini«'liat«l^  aAcr 
dpnlh,  rupiilly  divi<M  iiiin  «n>nll  piccm,  tlimwii  into  builiDj;  vriii«r,  rubbed 
lip  aDd  builfd,  ■  deciclioii  tniiy  bo  obuinvd  which  nAcr  c-Arvltil  n«utraliia- 
tion  iumI  liltnilian  will  be  toli^rably  I'rra  I'roin  pmleid  runlter.  Such  a  decoo* 
ttoD  is  r«mnrkJibly  opnlewvnl.  mitky  in  farl  in  appearance,  mueli  more  »o 
than  a  similar  decoction  froin  niuscto  or  other  tisEue,  aitd  rcniaioit  oimlMoent 
even  after  repeated  filtmtioD.  Treated  with  iiHtine,  the  aututioii  turn*  a 
br»wwiali-re<i.  poH-wiDe  red  color,  not  unlike  thnl  given  by  dextrine  wlii-n 
iodine  io  added ;  tlie  color  diMppeare  on  irarniini;.  but  reupjieur^  I'n  ■.■noliu;; 
iircividisl  that  not  too  much  proteid  matter  hiu  been  lelV  in  th«  Kotutitin. 
Fri'RiH  with  Feblinjc's  Huid  «r  other  teatA  fur  mifpr.  the  ttolution  ix  fouiu) 
to  coiKaiti  a  ^inall  and  variable,  but  only  a  siuall,  (piantity  »J'  aiigar. 

If  the  volution  be  ex{)<>-ei|,  pret^rablv  in  th«  warm,  to  the  action  ofiwliva 
orof  aonwotlwrainylolvliefi-rtiient.or  lie  Ixiilcd  with  dilute  add,  the  Opalea- 
cenoo  dimppean ;  and  lii*  now  clear  tmnnparcnt  «)!ulii«i  giv«  no  longer  the 
port-wiiH)  n«cLion  wttb  tndine.  T<»tird,  inoreovi-r,  with  Kehliiig'tt  Huiil  or  by 
other  nimnt  it  in  now  found  to  contain  a  considemblc  i|uantily  of  eugar. 

If  alcohol  br  additl  to  tht-  «[ial(-;!<-<-iit  onliition  until  the  mixture  coniaine 
tW  per  cent,  of  the  alcohol  (previooo  t-(inc4-nl ration  by  evaporation  being 
desirable)  a  white  nnwrphoutt  pn>cipitale  is  thrown  duwn.  This  precipitate, 
removed  hv  filtmtion,  boiled  with  an  alcoholic  solution  of  potash  in  which 
it  ia  iuaoluble,  but  which  dimolven  and  destroys  any  prutei<b  which  may  hv 
prwent,  treated  with  ether  to  remove  fatly  impurities,  and  washed  niih 
alcohol  may  be  obtained  in  a  pure  condition.  It  then  appears  aa  a  white 
anior|>hoii«  piiwder,  fairly  soluble  in  natcr,  but  alwavs  givinf^  ri^  to  a  milky 
opal«-«c<'nt  Aoliilion  unless  an  excov  of  niknii  be  pn?s«nl,  in  which  <-u»i>  the 
opnicweuce  may  be  slight  or  absent. 

The  opaletceol  solution  of  ihii  purilicd  nintcrtal  gives  a  port-wine  reartion 
with  iixUne.  but  no  reaction  whatever  with  Pehtinp'ti  fluid  or  thi-  oilier  AUgnr 
iwU.  Trmied  with  an  amylolytic  ferment  or  l>i>iled  ^1ith  dilute  acid,  the 
Botutioii,  like  the  raw  decoction  of  liver,  loses  its  opalescence  and  tta  port- 
wine  r««cti'>n  with  iodine  but  now  gives  abundant  evidence  of  the  preacnoo 
of  (Oigar,  dextroM,  if  boiling  with  acid  baa  beeji  emphiyed,  mallg»e  clii«fly, 
if  an  amylolytic  frnnent  hiu  lM^en  uned.  If  (jiiantitative  deterininutionil  DO 
employe))  it  will  be  fiiund  that  the  amount  of  nu^ar  uhlaiiied  in  pnipnrtion- 
ate  to  tlic  amount  of  (he  while  (Hiwdi'r  acted  U|n>ii  ;  in  other  nord*  Uie  MUh- 
utance  forming  an  opalc«c<.>nl  solution  i.*  converted  into  »ugur,  the  nolution  of 
which  18  clear,  Obviously  the  nuhatance  i«  a  body  allied  to  the  ■Iiifch  :  and 
thia  ia confirmed  by  its  cleincntnry  c«mj>o«ilion.  which  in  found  to  bi-  C,ll„Oj 
or  aoine  multinle  of  thU. 

Hence  thi»  nody  is  called  qfyeo'jfH.  And  it  Is  nhvlouti  I'nui  what  has  been 
sialyl  atxive  that  the  liver  ol  n  well-fed  animal  at  the  moment  of  deoith  con- 
Utin.i  a  coni<i<lerable  (|Uantity  of  givi'ogrn  either  in  a  free  stale  or  in  Kich  a 
condition  that  it  is  »et  free  by  subjc'tiiig  the  liver  to  the  action  of  hoitiug 
waUrr.  We  may  add  that  il  occunt  in  tlte  liver  in  the  hepatic  colU,  tor  the 
reaction  of  a  jMtrl-wine  color  given  under  certain  conditions  by  the  hepatic 
ceils  (S  ■!■''")  i»  due  to  the  preseme  of  glycogen  iu  them. 

S4M.  If  the  liver,  inntead  of  being  treated  immediately  upon  the  deatli 
of  tliv  animal,  is  allowed  to  remain  iu  the  body  of  ibe  dead  animal  for  aer- 


674 


TUE    UETABOLIC    I'RUCKAitK:*    OK    THE    ilUI>V 


■U    lUIB 


rntl  licMirx,  4V|H'ciitlly  iii  »  wnnn  pinoe.  buforv  n  decoction  i*  iiinil<^  of  il, 
iJwicU<iii  will  bir  r»iiu<l  to  hnvu  litllc  or  tio  himIoociim,  to  )»•  iiiiitr  or  nnirlv 
i|uiU'  cit»T,  lA  giv«  liulu  or  ou  ]M>rt-n'in«  n-iu-tidii  nitli  todiixr,  hut  In  i-ontaiu 
It  ver}'  o(>ii«iilvrubl«  qumicitr  uftugnr.  A*  «<■  Imve  Miid  ulMJvr,  \he  dt^itctinii 
even  of  it  livi-r  tdki'ii  :iiini<^lintfly  itfttr  <K-Ath  p-nerallj  conUtina  aotne  little 
sugar,  itiiH  the  •iiiiintily  <it'  xiigar  in  tli<.-  liv^T  ii|>])viir>.  ii»  a  rule,  to 
Mcitdily  HlWr  il<'iit)i.  Ihe  kidihidi  of  glycogvo  tjimi uniting  m  th«  w 
The  nipi<iity  of  the  <liniiiiulioD  of  glycogen  itn<l  thv  rate  of  inervMe  of 
vary  much  uixler  vnritHii!  ciroinutitnt'es.  Moronvcr.  lite  dcrreuae  of  the  oiur 
and  theiiicren«eof  lbe<iihi.Tnr«not  ulniiy»  strictly  proporii oh al :  nnd,  iiidtivtd, 
some  obeervvre  bav«  insisted  ihul  tbrrr  is  mi  rclatioD  between  the  tw-u  pn»- 
cewes.  N  evert  he  Ices,  the  hnwd  fuct  renittiiie  that  if  the  liver  uf  tliv  miim 
well'fed  anininl  be  divided  into  two  halves  as  mod  as  possible  aAer  dMtb, 
uud  nue  liulf  thrown  into  boiling  water  immediately,  tvhile  the  otber  half  it 
li-ll  exposed  to  some  little  itarnith  ior  several,  suy  twenty-four  buMrv,  iJk 
de(N>ctii>ii  of  the  first  linlf  nill  contain  much  >>lyc»}^n  nnd  little  atijcar,  while 
(liiit  of  the  wcond  half  will  ooniaio  little  )(lycii-„'en  and  luui-h  adj^nr  ;  and  thia 
furl  may  be  taken,  until  (lie  ountrary  is  pruved,  to  ahuw  that  the  ftly 
pruieiil  in  the  liver  at  the  moment  ni'  death  is  jjrailunlly  after  death  by 
neliini  »r  other  omvertetl  into  titifrar. 

The  Hi-lioii  i^  that  of  some  agency  whiMe  activity  is  deatroyei]  by  the  lem 
iwraturc  of  lioilinfc  water;  1m!0(,v  the  din-dinn-t  re|)eatedly  ^iveii  iiliitve  [u 
tbrun'  the  liver  into  boiling  witt^'r.  Thi:i  nalnmUy  siiggnt*  tim  prcMrnce  in 
the  livi-r  <>f  an  nniylotylic  tVrmenl.  jliil  not  oaly  hiivc  attompis  to  Uutaie 
fruai  tl)<^  liver  mi  iimylolyti-.'  fcriiK-iit  fiiiUij.  in  llie  baiiiiK  of  miwt  ubaervvn 
at  l<.-4»l.  btil  the  <-xm!t  natiirv  i>f  the  sugar  which  npjxMrK  idiows  (bm  the 
cbaiign  ii>  not  alI<Tl<.«l  bv  nn  ordinary  aniylolytic  ferment.  In  the  <vwuf 
thu  iiiiiylolylie  fcnuent  of' saliva,  luuiereatic  juicv,  intawtiital  juice.  Mid  indMcl 
i>f  all  oth«r  amylolytic  aniiDuI  fluids,  the  sugar  into  whieh  siareh  ur  glyou- 
geii  in  cunviTteii  it  maltiMe.  Nun-,  Ihe  sugHr  which  appears  in  the  liv^u-  aAar 
death  is  dextrose,  identical,  as  far  at  least  as  ean  at  pmeat  be  made  mil, 
with  ordinary  dextrciM.  We  are  led,  thervfoixt.  to  infer  thai  tlie  i-haugr  of 
glyoogeii  into  sufpir,  irhicb  appears  to  go  ou  afler  death  b  ciirrii'«l  uoi  by 
•one  aetioD  of  the  liver,  pntiahly  of  the  hepatic  cell  itself,  which  is  dime 
away  niih  by  a  temperature  uf  100'  C,  but  which  is  nut  the  anion  of  a 
ferment  capable  of  beiug  isolated. 

it4S6.  We  have  used  above  Uie  phrase" well-fetl" animal  because  the 
aniouut  of  K'vciigeiu  prewmt  in  the  liver  uf  au  animal  at  any  <in«  time  a 
verv  variable,  and  Mjiedalty  dependeut  on  the  amount  and  nature  of  the 
f<>Ml  previously  taken.  When  all  food  i.<  withheld  fntrii  an  imimiil  Ihe  glyoo- 
geu  in  the  livcr  diminishes,  rajiidlv  at  finii,  hut  morv  nhiwly  iiftvmard.  Kvea 
after  oonH'  davi'  ntarviiliou  a  itmall  i^uantity  ii>  fr(!<(uetiily  itill  found  ;  but  in 
rabbits,  at  all  events.  lh«  nbolv  may  eventually  dii>iipiiejir. 

If  an  animal,  after  having  hr«n  Harvitnl  until  its  liver  mar  he  assumed  lo 
lie  ftv«,  or  alinixtt  free,  fmm  Klyi'ogen.  !k'  fed  on  a  diet  rich  m  osrbohydratw 
or  on  one  conaimin;!!;  esclu)ii\'t-ly  of  cJirbohyd rates,  the  liver  will  in  a  slmri  ticnc 
be  found  locontaiiiavervlargeiiuantity  of  glycogen.  Obviously  the  prnviia 
»f  earbiih  yd  rates  in  f'Hni  lead»  to  an  accumulalion  of  glyco^^u  in  tlie  liver; 
and  thio  is  true  both  of  slitrch  and  of  dextrin  and  of  the  various  tiirins  of 
sugar,  ennc.  grape,  and  milk  sugar.  The  ellect  may  be  (jitile  a  rapid  one.  fur 
iclyoigen  ban  lin'ii  founil  in  the  liver  in  cunniderable  ijuautity  within  a  ten 
Itvurs  after  the  introduction  of  sugar  ioio  the  alimentary  cauat  of  ft  »lurviug 
nninuil. 

If  an  animal  similnily  Ktarveil  be  fed  on  an  exclusively  meal  diet  a  ce^ 
lain  amount  of  glycogen  is  I'onud  in  the  livdr.     This  appeani  I"  \w  wjiecJnUy 


J 


Tilt:    IIISTOHY    OK    (iLYCUGEX. 


6-S 


Ihe  cMae  «il)i  tli«  lUif^  (pratMibly  uhli  nlher  cni'iiivuroufl  aDinwU  aUo\  nitil  in 
e«irli«r  uorks  od  IW  Bubje«t  ()i«  cniiMaDt  [m^cure  »f  j^lycogeD  iti  ilto  liven  of 
ckifM  ied  on  meat  iraa  rejfardod  a§  an  ini|H>rtant  iiidicHtion  of  tlie  t'lirniniion 
vtiibin  t)i«  IxkIv  n{  non-niini^eniKiH  fW>m  DitroK^nous  maieriol.  fiiii  in  ilic  tirxt 
l^aoe,  the  quantity  ol'ytvmgeu  thus  sloreii  up  in  tbe  Itvi>riu  the  roiilt  af  a 
meat  diet  ia  much  leas  liian  that  which  follciwa  ufinn  a  cnrhu-hrilnitv  ditrl ; 
and  in  the  lecond  place,  unliiian'  meat,  especiatty  IxinH-'fliuh  on'  whii-h  <l<>u;8 
ill  Mich  ex  peri  men  t«  are  usually  t«<I,  ctintaiii*  in  i(»eH\§  •>:>)»  cvriiiiii  uniKiint 
rilber  of  Klyoogtui  or  anmv  liirm  of  AU){ar.  Moreover,  uli«D  nnimali  are  Ted 
■Kit  on  meat,  but  OH  puntieil  |>ni[«i«),  such  an  tihrln,  cHAeiil,  <ir  albumin,  the 
quanlilv  af  gWci'gfu  in  tbe  liver  be<t>iu«  ittill  ainulli-r,  though,  acvoriliiiK  lu 
ttw*i  itiwrven,  reinuiiiinjE  greaK'r  than  during  star%-ati(in.  We  may  iiifiT, 
ihdreiure,  that  jttirl  of  tht-  glyc»ireii  which  Hii[)ean>  in  the  liver  after  a  meat 
diet  i«  really  due  lo  carlKihvdtMt"  iiiaivriiil!'  pri-^cnt  in  iho  m<-iit,  I'art.  how- 
ever, would  apiHMr  U>  be  llie  roult  i>f  thr  actiiid  pn>t«-id  fniiil ;  and  we  have 
Mmilar  evii|<-ik-«  thai  g'taliu  uikcn  lu  loml  lends  (o  ibe  formaiiuii  of  some 
jtlyco^'en  in  the  liver.  But  in  ilii«  rt^iicct  tln^c  nitrogenous  subatancee  fall 
lar  t>hort  of  carhohydrati-  malrrinl, 

With  regard  to  futi^  all  ubm^rvcrs  are  nerved  that  thcce  lead  to  on  accu- 
mulation of  glyooRon  in  the  liver;  an  aiiioMl  frA  on  an  exclusively  fatty 
diet  haa  uo  more  i^ycogeit  in  ita  liver  than  a  starving  animal. 

Hence  of  the  thie«  great  claaes  of  f-xHl-etuffs  the  •urb'^hydmlex  Hand  out 
prominently  aa  the  »ubManct«  vrbich  taken  »»  ro<>d  Iciid  lo  an  aocuniulatatina 
of  glycogen  in  the  liver.  We  may  rcinnrk  that  the  greatest  accumulati'iii 
of  glycogen  ia  efleoled  not  by  a  jnire  carbohydrate  din,  but  by  a  mixe«l  diet 
rich  m  csrlxdiydrateB.  A  ijiianiity  of  carbohydrate  mixed  with  a  certain 
|>n>]K)rtio»  of  proteid  givei  riae  to  a  larj^r  amount  of  glycogen  in  the  liver 
than  tlie  tame  quantity  nf  carbohydrate  ;;iveii  by  ilaelf;  niid  it  in  [Hiwrihje 
that  the  presence  of  an  afipropriate  quantity  of  (at  still  furtlier  iiMii'ti'  the 
actruinulation.  But  this  result  prttbaMy  depends,  in  |iart  at  tea;>t,  on  the 
fact  that,  though  lUflerences  may  be  met  nith  in  ditTereiit  animaln,  a  mixture 
of  the  several  <-laM>eti  of  f>HK)'iitiifl's  is  more  readilv  diitealrd,  rrsulling  in 
more  nutritive  jimti-rial  ImHiik  thronii  ujhiq  the  blotKl.  than  is  a  mnil  consist- 
ing exchisivdy  of  <in<-  kind  of  fo<id-ntul1'  alone. 

As  far  HI  wtr  knon-  at  pnw^nt  the  glyeo)j^-ii  which  tbu^i  appenn  in  the  liver 
as  tbe  n-«ntt  "f  lii-ding  i-ilbcr  with  any  of  th«  vatiouH  forni.->  nf  ciirbii hydrates 
or  with  |>rotei«l».  or  nilh  Mber  nulutanci-x,  i"  of  the  same  kind  and  presents 
the  same  cluiracten> ;  at  h-iiPt  «<■  have  no  evi4lein*  to  the  cnnirary. 

Tbe  eloriiig-up  of  glycngi-n  in  the  liv<-r  in  aUu  lullucuced  by  otber  circtim- 
stuueen  than  the  taking  of  focid.  For  iuntancr.  in  the  frog  an  increase  of 
glycogen  takes  place  during  the  wintpr  nuinth^  In  lint  suiiinier  inonihs  lite 
liver  of  a  frog  will  Iw  found  to  conlnin  very  little  glyco}.^-n  <Fig.  164.  C  , 
unlees  the  uniinal  has  litvn  iinvisually  well  fed  ;  whertMU  a  liver  examined  in 
midwinter  i  Fig.  1K4.  A  )  will  hi-  found  to  cotilain  a  (.xiiisiderable  quaniiiy, 
even  though  no  fiKiil  has  been  taken  for  months.  In  such  a  case  the  maieriii) 
for  the  fiirnialiou  of  the  glyeogeti  in  the  liver  miiaC  have  been  furiiivlitd  by 
aome  pwrt  of  tlw  body  of  Die  frog,  and  could  n«t,  as  may  Iw  the  cast-  wlien 
a  meal  leads  immediately  to  an  increase  of  givcogen,  be  supplieil  directly 
from  tlie  fnud.  It  seciiis  as  if  in  the  summer  the  frog  lives  up  to  its  capital 
of  hepatic  glycogen,  sjwnding  it  as  fast  almost  as  it  is  made,  but  ihat  during 
thi'  wtiitiT  a  iguaniiiy  is  funded  to  provide  for  tbe  demands  of  the  late  winter 
iiud  imrly  spring. 

This  winter  storage  of  hepntic  glycogen  Ja  the  frog  seems  closely  (Ic|wii* 
dent  '>n  temf-crBlure.  If  a  winter  frog,  whose  liver  is  prcvumably  mure  or 
less  hjAiU'd  with  (flycttgen.  he  expoeed  for  some  time  lo  a  leiupimiure  of  '20* 


&7ti 


THr.    MRTAIItil.U'    PRKCESSKS   or  TUB    HODV. 


itr  n  little  Itit'lKr,  ihi*  lii'er  will  alWrwiinl  [»■  fnmul  in  mntnin  litcto  nr  im 
glycofcen  (Fiv.  KU.  It);  and  ci>iivtn>rty,  if'  it  ■iiiiiiiiit  frn);  Iw  pX[Hi*rfi  m 
iiiiliiuely  oifliL  glv<-up-ti,  thdUfcb  not  in  nny  gn»l  t(aBnltly,  hcij^iia  lu  be 
i>U>r<Ml  ii[i  ill  the  tiri-r. 


rn.  IM 


'^^Bk. 


B 


V 


»f\ 


t^ 


>V*^'« 


iir* 


c 

Thm«  tnutt»  «r  TNB  umTK  cnu  M  TKK  PiHa,  j.nmiuT.i 
A.nll>nrtilnNl)w«uii,  Ttekmi (nm •  toK dsrlac  wIMs-  TlH«U>krwliu(*.ii»d|iKKi;Mlcninuln 
KNMiMcl  ■niiiiiit  ilic  Iliidcii,  tlM)  homi !(*■>''<"■•  onlortODW  uf  llwnllt  tabic  I'Wir  ■ul»|ii— il  rf 
Sljroorni.  «rluc)\  uu  I'nsviii  lu  I'oiul-knlilc  >buaikiir*.  Tbu  ODlcr  cum  OMUUinl  enuMfOW  •« 
Riobulo.  •lumn  u  ilHik  >i«iii;  lull,  urttnled  la  Uitlcil.  IbuclU  Khilnln  Tw;  ntxtt  K,  n:U>|U> 
IB  tljFtdKrii.  Takon  mno  n  ulslcr  n\«  which  hml  b(ca  >:«|4  nt  SI'  <.'.  fcr  Mi  d*}i.  n*  oetli  CM- 
lBlnirw>  lliitv (Ijrvomu aail  Ite  i>oMld  tnnnlf* an dUfcnHl  UtRnwhout  ihcpelL  la  t  iilmmt 
ftocucllM  ui|xvipl<lt  ihnnilI>>tauhlpK«ciita*MrilM(tarapi|iCBmii«,  o.iiarNdMlli.  luat 
bOMkniiuawr  rni|iUI«c«lMiKftri.  Tlia  MUtB»ranallan4alni»i  tPM>  flvn  rlfcocMi.  TiMfM 
tdiltnnnlMwcilUttnedltiroa^ioiitttaoo*!].  AtlihvanictiDcntHrruhtnSciMdliil  p*r«(iu.anto 
MM,  and  wc  Oak  n  to  tb*  •■•».  or  oiwtlr  to  tbv  wmc.  xailc, 

(407.  Uefore  we  alU^aifit  (o  diacusB  further  bow  food  aiiil  otlivr  cinium- 
■tancea  thiia  nlfcci  ilic  utyo'ifiti  iu  (he  liver,  it  will  be  det>irublL'  to  take  up 
the  matter  whidi  ve  lirit  on  tuie  Bide  iti  $  450,  vix.,  iIm-  consitlvntioii  of  tM 
liialAluvical  oliHUjint  oceiirrinR  in  the  be))atlc  ctllii  under  ^'arioat  c<>»dition& 
It  will  lie  ei^nvriiwnt  ft  bvgin  willi  tlie  cells  of  tbd  mora  distinctljr  lubulu- 
gland  of  lti<!  tntit- 

In  a  fnig  whieli  bM  not  b«cn  aubierlcH  to  any  imrinl  trmtnioDt  the  cell 
MubMauce  of  the  hqiniiu  cell  {ef.  Fig.  ItH.  A)'will  ^nenilly  be  finind  in 
r»ntain  linlg^d  in  itnelf  throes  kiiid*  of  malerial.  the  pivfnio.-  of  which,  if  not 
dim-ity  rerognixablf  in  the  rmli  ci-ll,  mny  l>«  demonstiKlcd  Ur  the  uw  of 
varimu  mgrittK.  In  the  firft  |)luci.\  oil  globuin  of  variuhle  liu  and  in 
varinhlr  anuHint  ar*  •CBtl«rrd  timitighout  the  t^ll;  »nniciini«e,  as  we  bavt 
alnrady  mid,  these  arc  extremely  nliiindiiDt ;  but  tlien-  is  otherwise  nothing 
vrry  Kitrniit  ubout  tlntt^  I'm  globules  in  the  hepatic  cell  to  demand  an^  dn- 
Oimion  coneerninf;  ihcm  apart  I'loiii  the  general  difcuMtoti  on  the  formatMii 
of  fnl,  into  whieh  we  shall  eutcr  later  ou. 

In  the  wt-oiid  plaoe.  a  uumber  of  sBiaU  discfelr  gnniilt^  may  be  Keo 
IndgH  in  ihc  cell  «ul)«t)iii<v.     llten  appear  to  be  tit'  a  pruteid  nature  anil 


Y    nr    iiLVC< 


l^niool  nliiiiiilaiit  on  tlw  iunvr  niili;  ol'llic  vdl  QMr  ibe  lutui;i)  of 

t  k)r  bjlr  |<aw*p'.    TIh-  |in-M'nc(i  of  th«'i>  griiiiuUw  in  clwtdy  d«pendeiit  oa  tlic 

imlT  "l"  lliL-  ■ligwtiir  ('mcmMw.     Thty  <liiiiitiL<)i  nlicii  ili((™iioii  t*  g<"ii>^ 

lUiif  ■ccintiuUte  Hpiiri  nrirrwnrfl.     I'lilliiig  soidi- oTtiin  ili-tJiilx,  wu  iiihv 

IT  thai  thcw  grnmilcf  behave  vrry  miuh  like  ihr  grniiii  W  in  itn  albumiiiMis 

Jivary  c«U.  a  iMDoimtie  <.-cll,  or  a  el)icr^iisiri<^'  ovll ;  iind  nu  ms)'  probnlily 

~ij  oMidude  thai  ihey,  like  the  gnuiulec  in  lbt«(<  celli^  nro  tti  Rume  wiiy 

nrncd  in  the  tommtiiii  uf  tbe  aecrvtion  :  dial  »,  in  their  cnev,  bil«. 

Ill  iIm>  tliiitl  |ilac«,  the  cell  txtniaina  more.  »j)ecialh'  in  ile  outer  paris 

^■tMrrr  itie  blnodveaeel,  anay  from  Lbe  lumen  ul*  the  bile  pawjige,  m  variable 

-^■.jUBiitiiv  of  luaicrial  which  tlifito  from  the  urdioary  cell  lubetjiuee  in  beiDf^ 

^ysliiM-  mhI  refrvetiro,  ami  bettoeslany  looking,  aod  in  fiaining  port-wiue 

red  with  iudine,  iaslcad  of  browuiin-^Ilow,  an  dues  ordinary  cell  subHtauoe. 

Till*  aiBtcriftl  it,  though  with  aoine  bttle  diHieully,  eoluble  in  water,  and  by 

tU*  aiwiiT  nuiy  be  diiMolvdl  uut  froui  the  c«ll.    When  this  is  dune  the  plaoc* 

wUcfa  h  occupied  apjienr  tut  vaouolea  <>r  guy*  of  various  si^ee  limited  by  bnn 

af  Uiecvll  tulMUnce,  Hhicli  thus  Ukw  on  the  form  of  a  netnurk,  the  nMabos 

of  which  ani  wid«r  n»d  more  cuDHpiLtiotis  in  the  outer  part  of  the  cell,  in 

tdich  tliv  hyaliuc  inat«ri«l  iras  prcvioualy  inual  abumlimi.     lu  the  inner 

fan  of  ihc  nil  «fa«rc  the  hyaliiK'  niiili-riul  wu  •euity  the  cell  riutwtance  iii 

■ora  dflMBt  Uld  ovta  in  the  <>ult-r  imrt  u  >liell  of  mom  ilciuc,  laa  reticiitnle 

nrll  sittntnnco  nflbrdv  a  dcfinitr  otitiiiK^  to  the  cell.    There  can  be  no  doubt 

liiMl  thin  hyaline  material  ia  cithrmctiia]  glycogen,  such  umaytx;  vxtr>rle<i 

from  lbe  liver,  or,  lu  mvau  more  probable  Irom  its  ilelicient  liobibility,  gly- 

OOgga  ill  some  more  or  lees  loow  oombiniitjon  with  wmi.'  other  body,  n  cnrn- 

biomliou,  hoirever. of  aiicb  a  kind  that  the  iodiiM  mwtion  makc«  i(>clf  fell, 

{  4A8.  The  above  may  be  taken  as  n  guieial  dncrijitioii  of  a  cell  in  an 
ordituu?  mtiditiou.  The  question  now  nunea  tiefore  us,  What  cbao)^  are 
bioui^hl  alxMit  by  various  foods  or  by  the  nbsenec  of  food? 

If  a  frug  be  largely  fed  on  a  diec  containing  A  tarR«  <iuaiititics  of  carbo- 

liydrmtAr,  the  liver  will  be  fuund  rich  iu  tcl.vogen,  and  tbe  cells  nill  pn»«nl 

tM  fullowini;  ebiinK'tem:  The  cell  \»  relatively  large  (</.  Fi);.  1G4,  A},  itnd, 

mm  it  mm,  twollcn ;  the  cell  Milmtanoe  b  largely  occupied  by  tbe  hyaline 

nuibrrial  juit  *|Hik<-ii  of,  uA|in'inllv  in  its  outer  part:*,  ao  that  iu  sectiout  prv- 

Hunl  and   muoiitrd  in  the  onlinary  iray  in  wnidi  the  glyoo}{eu  ban  betu) 

diteolvcd  imi.  iIk-  ^reati-r  fxirt  «f  tbe  coll  consisia  of  U  loose  open  uvtwork  of 

ban  of  Moinnl  cell  miImjuiic  with  wide  mesbea;  a  certain  qiumtity  uf  more 

•otitl. gtnerally  gmnulnr-ltHiking  oil  ■ubaionce  occnpEes  tlie  port  of  the  cirll 

iwrral  t)i«  Inmeu.  and  n  thin  »hell  of  erll  «ub»tancv  forms  an  envelope  for 

(bo  rest  »f  the  cell.     TIk-  nucleus  is  liirge  and  distinct,  but  ihouKb  chongnt 

ia  tbe   nucleus  aceon))<nnyiii|,'   chan}^->    in    the   cell  mbxlnnov   buve  bm-n 

dMCribed,  tbcy  are  not  sufficiently  im[H>rtant  to  detain  us  now.     When  such 

aedl  is  seen  in  a  perfectly  frosb  state,  the  hyaline  refractive  material  i  which, 

t»«  Dee<l  hardly  say,  givca  a  marked  reaction  with  iodine)  often  hides  tbe 
Uiiclvus  aud  the  greater  part  of  the  cell  substanee  proner. 
If,  on  tiM  ollter  liaud,  the  frog  be  Inl  ou  a  proteia  diet  free  from  oarbn- 
Hytlratos — for  iastanee,  on  librin— the  liver  contains  little  or  no  glycogen, 
%tKl  tbe  be|iaiic  cclU  ore  not  only  much  sniuUer,  hut  present  an  ap{>eanDi'e 
%enr  difllnxnt  from  tbe  above  (i^'.  Fig.  t*>4,  B  i.  Little  or  no  bvaliiie  material 
Sa  visible,  tJie  cclU  give  little  or  no  port-wine  reaction  with  iodine,  but  only  ilie 
UMwl  b row u-yel lour  proteid  reaction,  aiul  in»|iecitiicns  prepared  and  mounted 

tin  tbe  ontiiuiry  way  the  cell  aulwtance  npjiears  densely  granular  throughout. 
L«tlv,  if  lbe  frwg  be  »tarvcd,  and  if  to  tbe  elfecls  of  stnrvniion  there  lie 
■iUl«d  lliose  of  vxfHHurL-  l»  a  bi;;h  tetuuerature  (20"),  by  which,  ss  ko  have 
a(«o,  tbe  hepatic  orlU  are  uiuckedly  aifected,  the  liver  is  found   to  be  free 

87 


578 


THE    METABOLIC    PROCESSES    OF    THE    BOBV. 


from  glycogen,  and  the  hepatic  cells  tfl  be  extremely  small  (cf.  Fig.  16-1.  C), 
only  naif  the  size  or  even  lesa  of  those  of  the  weii-fed  frog,  btit  othenriae 
much  like  the  celU  in  a  frog  fed  on  ])roteid  material. 

§  459.  In  the  mammal  changes  iu  the  hepatic  cells  similar  to  those  jtut 
described  as  occurring  in  the  frog  have  also  been  observed.  When  the 
animal  is  fed  on  n  diet  rich  in  carbohydrates,  and  when,  therefore,  as  we 
have  seen,  the  liver  abonn<lt  in  glycogen,  the  hcpalic  cells  (Fig.  165)  are 
larger  (so  large  tluit  thev  have  by  some  authors  been  described  as  com- 
pressing the  lobular  capillaries)  and  loade<l  ivith  the  the  same  refractive 
hyntine  material  staining  port-wine  red  with  iodine.  When  this  material  ii 
dissolved  out  a  coarse  open  network  of  cell  substance  is  displayed.     THk 


Flo    W: 


Yic.  ir*. 


Sxi.TluN  uv  Maxxai.ia:!  Livek  Kkh  is  <Jlvcii- 

r.tN.      lI.AM.I.EV.t 

llMiilc  nfM  si-CPiiiu-ii.  cljTi)[iCii  iiul  .11.s*"1vli1 
nut. 


Siy.TLlIN  OF  )l.lM)l*r.TAN  I.IVEB  CONTAIKIini  Ln- 

TI.E  f.lt  Nil  lilVIOr.KS.      it-ANCLEY.} 

fi«iiiti' Hoiil  sfN.'^'iii^'^u,    The  L^ranulefl  are  nM 
\n'll  jirtsi'iTfil  111  Kime  of  the  coll*. 


most  marked  ]ioint  of  difference  lH>tween  the  mammalian  and  frog's  hepatic 
ce)]  under  these  conditions  is  that  in  the  former,  the  liyaline,  glycogenic  sub- 
stance is  gathered  at  first  centrally  around  the  nucloua  (not  more  on  tbe  outer 
side,  as  is  tlie  case  in  the  frog)  unil  sprciuU  from  the  centre  toward  tbe  peri- 
phery, always  leaving  on  the  extreme  outside  a  somewhat  thick  shell  of 
cell  siibstiinoe,  which  in  hardenctl  and  j)repared  .'iwcimeus  may  strikingly 
stimulate  a  tbi'kened  cell-wall.  We  may  iid<l  that  in  an  animal  thus  led 
the  whole  liver  i*  very  liirge,  and,  iia  it  were,  swollen ;  it  is  also  soft  and 
tears  easily. 

In  an  animal  fi'd  on  proleids  alone,  fur  Instance  on  tibrin,  the  liver  fre- 
(jut'nllv  contains  ^omc  glvci')gen  and  the  licpiitic  cells  contain  a  small  quantity 
of  hyaline,  ;rlycogcnic  materiiil.  As  in  the  cninvspimding  case  in  the  frog, 
the  cells  are  comparatively  small,  and  the  cell  i^iibslaiice  appears  finely  and 
unifornily  giiiniilar. 

In  a  starved  mammal  the  liver  is  small,  dense  to  ilie  touch,  and  tougb; 
it  <'ontain,-'  a  trace  only  of  ;^lycoL'cn  or  none  at  all ;  llie  cells  (Fig.  166)  are 
small,  as  it  were  shrunken,  and  the  cell  substance,  which  gives  nu  port-wiae 
reaction,  or  a  mere  Lniee  only,  with  iodine,  is  still  more  finely  granular. 

S;  460.  The  mieroscopio  apiiearanw's  just  described  show,  and  indeed 
general  considerations  lead  us  to  the  same  conclusion,  that  the  processes 
taking  place  in  a  hei>alic  cell  ;in-  very  eoni])lex.  In  the  first  place,  the  con- 
stituents of  bile  are  being  formcii  and  dischargeil  into  the  hile  passages  ader 
the  fashion  of  ordinary  secreting  gland.  In  the  second  place,  a  forma- 
tion of  glycogen  is  also  taking  ])lace,  and  we  shall  have  prest-ntlj-  to  consider 
briefly  the  relations  of  the  one  process  to  the  other.  In  the  third  place,  U 
is  esiMH'ially  indicated  by  the  somewhat  peculiar  ell'ecls  on  the  hepatic  cell  of 


■t  cxclilfiively  [iroleiO  in  ualiire.  olh«r  proceSMS,  similar  pcrhnp-  to  tliw 
.  iriiintidii  "f  kI.V*."OR^".  hut  i">t  nwultiiig  in  the  ttUarajge  of  any  cnrlv>l)y<lriit« 
lUiiU'rial,  und  denriug  poanblir  with  pnteiii  DtibslAncea.  aUo  take  phioe. 
Hciicc  llie«xacl  inlefpretstion  of  all  the  ohaoKes  whioli  may  be  obierved 
l)i-iMii)Cti  exc««iliai;fly  ditGouK. 

tA>avinK  the  proi-eMes  of  the  first  an*)  ttiird  kind  whollf  on  oq*  Bltle  for 
th«  itrwent,  and  Donrminjr  our  nttenlioD  entirely  lu  the  glycosfeu,  it  i»  obvious 
that  tbe  li«|MLic  cell  manulaut^irai  the  glyiv>^en  in  aonie  wkv  or  other  and 
hxIgM  it  ill  iK  own  subatanee  for  tlic  time  vrry  inuvh  in  the  wav  that  a 
wcrcting  oell  wanufacturaii  nud  hMljtei)  in  iiaelt'  for  ii  tiuin  raat«ria)  fir  tbe 
secrvtioD  vrhidi  it  h  ubuut  to  puur  forlii.  Then-  i»  thix  difliiniice,  that  in 
Umi  odo  com  tiw  malarial  »f  the  vpcn'tion.  aTtf-r  iin'htr^iiin:^,  n»  wc  havn  Mtcn, 
more  or  Ian  dinngv,  !#  cmt  out  into  ibv  Igm^n  of  thr  hIv<-<)1ii«,  whcroai  Id 
the  other  CKH'  the  glrmiD'H,  which  rnuot  iindori;<i  citiingo.  sinoo  it  may  ba 
made  to  diKiiiiiK«r  rapidly  from  ttu'  h<-:|>iUii.'  ovlf.  u  not  when  chaiigod  CAtt 
out  into  the  bile  pawag** ;  it  must  lhi.-)er»re  bo  wut  back  iigiiin  to  iho  bliKid. 
461.  \Vi-  My  "  mnniiftietiirvi  the  glyeogni  in  Dome  way  or  oth<;r,"  und  wu 
have  DOW  to  in<|uir«  what  we  know  ouiiconiiiig  the  iinture  and  the  wveral 
Hef»  of  this  mtuiufiicture. 

We  have  already  teea  thiil  the  presence  of  ({lycogen  in  the  liver  t* 
eepevtally  iRTored  by  a  carbohvdrntv  diet ;  and  in  our  studies  on  digestion 
we  have  seen  rvuMn  to  think  thni  a  very  lar^  part  at  all  events  of  ihv 
carl>»hydrato  material  of  a  meal  i^  absorbed  as  sugar  by  the  cnpillnries  of 
the  intcatiue  and  carried  as  stigar  to  the  liverr  in  the  portal  hloud.  Hence, 
it  seems  only  reasonable  to  conclude  that  the  jtlyeogeu  which  makes  its 
appCNianee  iu  the  liver  after  an  amylaceous  meal  arUei^  from  a  dire;:t  con- 
Ttn>iou  of  tlte  sugar  carried  to  Ihe  liver  by  ilie  portal  vein,  the  sugar 
bocunting  ihrotif;!)  s^nie  autimi  of  the  hepatic  cell  aubstanee  dehydrated  into 
'  icugeu,  or  animal  starch,  as  it  lia^  been  called,  the  ;>ri)m-«t  l>e^in)c  a  reverse 
Uial  hv  which  in  the  alimenlary  caaai  starch  U  hy(l^al<^•l  into  sn^ar 
Ihrtiu^h  tite  nclii>u  of  the  salivary  and  inncreatic  frriii tnti.  V'c^table  cells 
can  iiudoiiiitciliy  convert  b>>lli  starch  into  sugar  and  mignr  into  Mareh  ;  and 
Iheni  an:  no  it  priori  argnuietits  or  p'isitive  fact-t,  which  would  ]<:ad  us  to 
suppcM  tliai  tlie  activity  of  animal  Mvinjc  sulkstance  cannot  noconijiti^h  the 
Iflllnr  an  well  as  the  former  of  tlieiM  changes.  Wv  arv  <|iiiic  igii  iraiil,  ir.  is 
true,  of  tbo  exact  way  in  whloIi  dther  ibe  liyilrnlton  or  the  dehydratiou  Is 
edertetl  by  living  subslaiiue;  but  we  are  U'lriiiUy  ignorant  of  tW exact  way 
in  whii'h  an  amylolytio  ferment  eflr^t^  ilie  hydration  of  starch  into  sugar, 
which  it  cnrrim  out  with  *<>  much  apiiarent  ease.  It  is  not  a  grent  assumption 
tn  MipjinM)  that  the  <^>ntinually  ciuinginz  living  snlMtnnoe,  which  in  its 
ehangei  is  continually  giving  out  energy,  has  the  pswer  of  acting  on  in<>!c- 
ailea  of  starch  or  of  «U|jar  in  contact  with  or  even  only  near  lo  itwlf,  and 
»<>  of  hydrating  starch  into  the  sugar  or  of  dehydrating  sugar  into  starch. 
Tlic  latter  process  may  lie  a  more  difficult  one  than  the  formsr,  but  not  one 
boyoud  tlie  power  of  the  living  ■iibstnnca.  We  may  fairly  luppiss  tb.it  a 
<|Uaiility  of  sugar  in  whition  preicnt  in  a  vacuole,  for  instance,  ot  the  hepatic 
cell  snltBianoe  can  be,  by  Mine  action  of  the  oellsubstani.-e,  converlol  into 
glyc'igen  in  a  eolid  firm,  filling  up  Ihe  vacnole.  Again,  as  wa  have  inci- 
dniiatly  mentioned,  sugar  iiijocied  into  the  jugular  vein  readily  give^  rtw  to 
»ugnr  in  tbe  urine:  but  a  very  co[i«iilcrabIe  ((uaucily  can  ha  slowly  inject«d 
iulo  the  purtal  vein  without  any  appeariu^t  in  the  urine.  This  suggests  the 
Mm  that  the  liver,  so  to  speak,  catches  the  sugar  as  tt  is  passing  thruugh 
•Vtt  hciHitic  capillaries  niHl  at  once  dehydrates  it  into  glycogen. 

Similar  eonsiderations  may  iilso  be  applied  to  the  onse  m«nti<med  above  of 
the  npjwnTaiiee  of  glyct^u  iu  the  hepatic  cells  of  winter  (fasting)  frogs 


Doe 

iBr 


680 


TIIK    UKTAHOIJC   fROCKSSEH  OF   THE   BUDY. 


We  hsvo  mson  tolhiiiW  ihnt  8Ue»r  inakco  ila  uppauiincc  ni-  a  product  nf  the 
iueliili'>]iitni  uf  various  liiviicK.  Tltf  sugitr  tlius  armae  tiiKltiiK  its  wnv  iiilu 
blood  may  be  ntde  use  of  at  once  pltewln^n?,  conv«rted  B^teedil.v  tor  iiutaaw 
inio  carbonic  acid  «nd  so  ^i  rid  uf.  Hut  we  onn  tvadiljr  )iDattii>e  'tuit  uttder 
certain  circuDuinDot^,  ua  tor  inotaDce  when  the  aclivitieB  of  the  ouitanl  w<tR 
leneoed  by  a  Ion  temperahire,  it  was  Dot  so  made  use  of  and  reniniii«d  id 
the  bloo<l.  If  so  it  would  in  the  couree  of  the  ctrctilalion  lie  ntrrieil  to  ibc 
Liver,  and  mixbt  be  at  ouce  laken  up  bv  tlie  ItefHiiic  c«lU  aud  ooiivrried  into 

Slyeogen ;  and  theee  mijiht  be  sa  active  that  the  blow)  waa  never  at  aay 
nie  allowed  to  remain  loaded  willi  augar  to  such  nn  ext«nt  im  to  pamiit  ■ 
low>  tbhmuh  tbe  urine. 

j)  462.  f'iH>ii  such  a  view,  tlie  carbohydrate  taken  as  food  would  be  coa- 
vertod  iiilo  glycogen  by  tbe  agency  of  the  he)Millc  coll,  without  lU  any  tiiM 
tiroomiiijt  an  lute^al  port  of  Itie  living  i>ub*tnnc«  of  the  ooll.  8<ich  a  view 
mav  be  Die  Lnie  one;  but  it  i»  open  fi>r  ux  to  look  at  tiM  mattcT  in  nnotbef 
ligfil.  We  way  piiHh  ulill  fiirtlKT  the  iiniilog)-  Initwoeii  the  glycogen  of  the 
be|<ntic  cell  and  ihv  miiu-nHl  with  which  u  erarctiiig  evil  is  Imuled.  lu  deal- 
ing with  socrction  we  eaw  reiuons  fur  regarding  mcJi  a  body  aa  mucin  to  be 
a  pnKiucl  of  the  inetjtboliHm  of  tbe  cell  substance  of  the  muooup  <.-ell :  aixt 
we  may  HQiihtrly  regard  glycogen,  or  sugar  readily  ooDverlible  into  Klyoi^Mi, 
or  at  least  some  or  other  carbohydrate  material,  as  a  normal  produit  «f  ih« 
metabolism  of  the  hepatic  cell.  We  may  ihua  conceive  of  the  heiwtie  cell* 
as  being  continually  engaged  in  giving  rioe  to  carbohydrate  material  in  the 
form  either  of  sugar  or  of  some  other  body ;  aud  we  may  aupfnae  that  under 
oertaio  circiinistanc».  as  in  the  absence  of  ado^uate  foml,  the  carbuhyilrau 
material  thus  formed  is  at  once  discharjiied  into  the  blood  oT  the  hi'imiic  vetu 
ibr  the  general  use  of  the  body,  but  that  under  other  cirvumiianii'^.  a*  wlien 
an  amylftceoas  meal  has  been  taken,  the  immediate  wants  uf  the  lymooioy 
luring  covered  by  tbe  carbobydrntee  of  the  meal,  the  cMrlMihydniti-  nmductt 
of  the  hepatic  metabolism  are  stored  up  as  vlycogen.  V'nd^r  siirli  a  vie> 
the  sugar  uf  the  mml  i»  ii--ed  up  aomewoere  Tu  ijie  Inxty,  and  the  glycc^cn 
to  the  Ht(ini)ti:  of  w  liicli  iu  lli<!  liver  it  j^iven  lice  comf«  direct  from  the  hepatic 
Wibatance.  And  a  •imilar  cxplaiuiliim  may  bet  given  of  the  storitiff-iip  itf 
glyengeii  in  the  liver  undir  ouch  ctrcum*liuim<  lu  thuee  of  the  winter  tiof 
previoiiiOy  nn'uiioncd. 

We  do  not  pummu  at  nn-scnt  ex  {K-ri mental  or  other  evidence  of  so  dov  a 
kind  a»  to  enable  ue  to  decide  dogmatically  betvcen  llicae  two  viewii ;  we  luv 
limited  lu  very  general  indications.  We  have  seen  that  prateid  fixicl,  though 
iu  tluH  re«|>ei-t  (ailing  far  below  carbohydrate  food,  does  or  may  givr<  riae  to 
a  certain  amount  of  glycogen  in  the  liver;  and  gelatin  seerati  Ui  haw  tbe 
san>e  eSecl.  Further,  in  ceriain  cases  of  the  disease  diabetes,  of  which  wo 
aliall  liave  to  speak  presently,  and  which  is  cbaraeteriitetl  by  tlie  pr>Meuce  of 
a  large  amount  of  BU);ar  in  the  blood,  sugar  continues  to  be  fonnc*l  in  larn 
(|UBQlity,  even  when  the  diet  a  restricted  to  ]>ruteid  and  fatly  luuttcrf,  ul 
cHrtM>h  yd  rates  being  excluded.  Mow  in  dinbelva  wo  have  reaanii  to  believe 
that  tbe  laKe  quantity  of  sumr  in  tbe  bloo<l  ia  acconipani<.-<I  by  a  lam 
deposition  or  glycogen  in  the  liver,  and  iwieed  in  other  tifxncs ;  lor  in  ibe 
tnt  ouea  which  have  been  examineil  suHiciiiitly  KH>n  aOcr  dcalh,  and  to 
whtdi  owing  to  itie  niddennew  uC  the  dutth,  there  niL>  no  opportunity  KiT 
Mored'Up  elycrigi'ii  to  dinaiijii'ar.  a  very  large  ouiinlity  of  clypo^Tn  hat  lieea 
fiHiitd  in  the  liver  or  iti  onic  otlirr  organs.  Henc«  the  jiTieiiimtena  of  dia- 
betes may  be  taken  a*  ithoniiig,  in  n  much  ni'ire  striking  mnnuer  than  do 
any  experiments,  that  protcid  material  tuben  as  food  may  give  ri»e  to  lte|)atio 
glycogen.     And  thi*  at  lirst  sight  Meme  to  alford  proof  that  the  liejwtili 

Slyoogen  is  a  product  of  the  metabolism  of  the  hepatic  cell,  the  activity  <if 
le  cell  being  Bliniulaled  as  it  were  by  the  presence  of  the  proteid  fiuKl.    But 


THE   HISTOBV   OP  OLYConKX. 


081 


I 


I 


I 


ihe  |in>»r  is  not  cogent  in  (he  fact  of  our  igiioraiice  »f  the  metabolic  chnni^ea 
which  th«  protvid  material  of  fixnl  uiiitiTfiiom  In  tbo  Ixxly.  An  we  shall  insist 
ii|H>»  ill  more  detail  later  <m,  )>r'jt<ri(l  iimti-rial  in  giving  riiie  to  urea  thmwi 
olf  WMuewher«  in  [be  timly  a  lar)^  <|iiuntitf  of  »  ciirboii-coutiiiniog  radick  in 
•omo  coinbiDatinn  or  other;  l)i«  proicid  fontaiii*  liir  more  vnrboii  Utao  b 
D««de(l  to  uuiie  with  the  nttrogito  li>  form  urea.  We  i^hnll  ntx  that  th\* 
excess  nf  airlxm  linn  n  icjidiiicy  to  apjieitr  in  the  form  of  Ikt.  ))iit  wc  may 
readily  mippiim  that  it  might  tempomrily  us  a  preliminary  proceM  or  under 
certain  oirciim»timrc».  t«ko  on  the  form  of  Nifnir.  And  we  may  fUrtlicr  sup- 
poae  that  tiiii  augnr  it  formed  out  of  the  proteid  nut  in  the  liver  but  in  some 
other  tiwue,  in  muecle  for  instance.  Jtui  if  ho,  hep^uc  glyco^^n  which  u 
ihu  revult  of  proteld  fiiod,  may  alter  all  be  formed  iu  the  liver  by  simple 
dehydration  of  au^-v  foond  elsewhere,  and  brought  to  the  liver  in  the  {tortal 
bhHid. 

Wo  cannot,  we  say,  at  prcwnl  deride  Iwtween  tli««e  two  vien-a ;  and  indeed 
it  may  he  thai  l>oth  views  are  true,  nr  ratlier  that  the  true  concepliou  ein- 
briices  both  view«.  It  may  be  that  the  normal  nietaboli«m  of  the  Iiepatlu 
oell  diiea  priKluve  a  certain  amniiiit  of  carbuhydratc  mati'rial ;  but  if  »j  the 
probability  is  that  the  exnci  I'-irm  in  which  that  carh»hydr«lc  apiieant  in  the 
Arst  inmance  In  tbi- la b<i tutor v  iif  thvot-ll  u  iK>t  that  of  glycogen,  hut  of  aagar 
of  »ome  kind  or  oilier.  nn<)  tliat  iho  convcr«ion  into  glycngcJi  is  a  milHiitltary 
act  for  the  inirp^Ho  of  retaining  tho  carbohydraTi^  iiialcrinl  in  the  gnwp  of 
th«  cell.  ]f  thi*  he  (he  case,  then  until  it  has  boon  iihown  that  thert'  is 
siinietliing  peculiar  about  the  augur  ihnx  produced  by  the  coll  itwlf.  hy  virtue 
•d*  which  it  alone  can  be  converted  by  the  celt  into  t^Iycot^en,  we  may  I'airly 
infer  that  the  c«II  might  alao  convert  into  glyco(>en  ei]i>ar  pacing  into  the 
iiitonticcs  of  the  cell  substance  from  the  portal  capillariee. 

S  M8.  We  may  now  turn  to  another  <)ue8tioii,  the  answer  of  which  is  in  a 
measure  dependent  on  the  one  which  we  have  jii»t  diauussed.  Whnt  is  the 
u*e  and  purpose  of  this  hepatic  glyivi^.^en?  What  ultimately  becomes  of  the 
glycogen  thus  f»r  a  while  .iton-il  up  in  the  liver? 

One  view  which  Inw  lieen  piil  forward  u  as  follows:  We  have  evidence, 
•a  we  shall  preaeiitty  U-ani,  that  u  gn-at  deal  of  thu  fat  of  the  body  is  not 
taken  u  such  in  tlni  t'oui),  but  in  constructed  anew  in  the  boily  out  of  other 
•ubstuoot.  Etoth  carhiihydniKs  and  pnitci<U,  taken  In  exceas  or  untter 
GcrUdn  Hrciinutancr*.  lea^  to  an  accumulation  of  fat ;  and  ve  have  reason 
to  heltvve  that  cnrliixlvdmUv  un  the  one  hand  and  the  carbon-holding  por- 
tions of  various  protcids  on  the  i>tlier,  may  hy  some  proccM  or  other  be  oon- 
rerted  into  fat.  And  it  bus  been  sugetsted  llint  the  glyuo^n  in  the  liver  is 
a  phitM  of  a  constructive  fatty  melaMiiam,  that  it  it  material  on  its  way  to 
bvcoatefat. 

The  pKsitive  evideiiL-e  in  favor  of  this  view  is  very  scsniv :  it  is  almost 
limited  to  the  facts  that  fat, sometimes  in  very  largo  qiiantily,  14  found  in  lUo 
hepatic  celU,  that  while  fat  itiself  ukeii  a*  food  InwU  to  uo  increaw  in  tli« 
hepatic  glvcojien,  oarbohydrates.  which  are  edpecially  fatteninj;,  are  must 
active  priMlucers  of  ^.'IvcoKon,  and  that  the  fi*t  pr«Knt  iu  the  hepatic  cell* 
mvatt  to  l>e  increu^ie<l  by  suoh  diets  as  natorally  iucresM  the  glycogen  in  the 
liver.  Kn  eviden<-i^  ha«  been  itflbred  as  to  (he  occurrence  in  toe  hepatic  cxM 
of  any  nf  tho  several  rH«\a  of  tlie  conversion  of  glyooiien  into  fat,  nor  indeed 
hMH  it  horn  suggested  what  ihu^ustttjKt  are.  The  view  indeed  is  almost  ox> 
cluaively  hoMid  on  the  supgxiMil  jir<>i>f  that  the  hlood  of  the  heuatic  vein 
contaiiw  durinz  life  no  lujfir,  or  nt  lea.Ht  not  more  than  does  toe  general 
blood  or  uvei)  tn«  blood  of  the  portal  vein.  From  iWn  it  is  inferred  ihit  tho 
glycogen  in  llie  liver  is  n»t  1o«t  t<>  the  liver  by  becoming  converted  into  sugar 
and  w»  di»cfa«T:g«(]  into  the  hepatic  blojd,  and  tbereHiro  muM  bs  converted 


574 


Tilt:    UETABOLtC    ntOCKSHICS   OK    TIIK    ItOPV 


cnil  lioiini,  «!»|><'ciaily  in  it  wani)  pliioe,  Iwf'irv  n  Jecocltun  w  mmUi  nf  it,  tH 
iJi.^MicUun  will  \h<  f'oijiul  tu  liiivi'  liule  nr  iiu  ii|Hi)c*eenee,  to  he  quita'  or  iH«rh 
quite  virar.  In  ^ivc  litllc  or  no  ixtrt-mini-  n-ai'tioti  nilli  iotJiiHi,  mil  to  iiinlJiiii 
K  very  oun^iilcriilili'  iinniiliiy  of  otignr.    Aa  <Htr  Iiiivl*  nuiil  hIkivc;,  th<*  il«-(VK.-ii>iii 
tmu  of  II  liver  lnki'ii  iiiini<vJiikU'ly  iifl«r  ilfiitb  ^'iit-rally  <<(mtui»N  iHtiiir  liul* 
sugar,  iind  lh«  <|iiiuiiily  of  iiugiir  in  tin.'  liver  tt|i|n'nr»,  mi  h  tuiv,  I»  iiifraur 
ol^adily  iiAtr  <li-iilli.  ihc  ■moiiiil  uf  jilyro^'ii  ilmuiii*l)i»g  at  lbs  midv  lime 
Thv  Ta|)iclity  nf  the  iliniiiiiiliui)  «r  iflycogni  oikI  tlir  ntti  itfincrcuB  uf  eujtir 
vaiT  nititti  uixlcr  vnriou»  circiinislnitcoi-     Momnviir,  lliu  (ImrriMtM.'  of  t.he  oaf 
and  the  increase  of  the  olhcr  nro  nut  nU*ii)r«  Mrictly  ^ir-iporlional ;  and.  indenl, 
some  obnrtvn  have  nuMstcd  ibat  there  »  ni>  ri-Iation  bi-twtivM  tht?  ;wo  pro- 
cenee.     Nev«rthel««B,  th«  hmad  fact  romnins  Ihal  if  tin.-  Itvur  of  the  aanw 
well-fed  aninial  he  divided  into  two  balviw  n»  »oun  nc  piiwihie  after  dmlb, 
and  one  half  ibrrtvD  into  hoiliu);  water  imiuediately,  white  iImi  i>iher  half  it 
loll  ex]Mi«ed  to  aotne  little  warmth  for  Mvernl.  say  twiiiiy-lour  hount,  tb> 
decoction  of  ibe  flrat  half  will  ooiitaio  much  ((lycogoii  and  litllc  8U);ar,  whilt 
that  uf  tl»e  second  half  will  ouniain  little  (flyco^'en  and  tiiuuh  ftU)pir  ;  and  ibi* 
liict  may  W  taken,  until  the  cunirary  is  proved,  to  eliow  llial  the  ti'ycutrm 
jint:iciit  in  the  liver  at  the  uwiueut  of  death  is  ];radiially  af\er  death  by  nomn 
iK-tion  or  otJMtr  converted  into  »ugar. 

The  action  la  that  of  ai>me  ajt'iifiy  vrhow  activity  is  destroyed  by  llie  tem- 
IMTHliiro  of  loiilitijk' water;  beiici;  the  <lirertiuiia  repeatedly  jciv en  abuv^  to 
thriiw  the  liver  into  iKiilio);  wati-r.  This  naturally  suicgeata  tli«  [ircwnoe  in 
thv  liviir  of  an  uiiiytolylic  fiTim-ot.  [tut  not  only  have  atienipis  to  iioJaie 
fiviu  the  liver  iiu  iimylolytic  frrnn-nl  fuiln),  in  the  hands  of  iiitMt  obsei*V«n 
U  lenat,  Ixit  the  exact  nature  of  ihe  vugar  vrhieh  Hii)iean  *hotti<  tlial  tbe 
I'hati^-  M  not  n(li-cli.>d  bran  ordinary  umylolylic  fi-rment.  In  the  ease  of 
ihe  umylolyiit-  Ivrment  of  saliva,  iitimn-atio  Joioe,  intentinal  jnicr,  iiitd  indesd 
of  all  other  ainvlulytio  Mlimal  llui'U,  Ihv  sugar  into  which  utandi  or  |{lye»- 
cvn  is  convertetl  is  maltaai.  Now,  tlie  sugar  whidi  ap{irani  in  ilie  liver  after 
death  is  dexlnine,  identical,  as  far  nt  least  as  «'Jin  at  prescui  be  made  uut, 
with  ordinary  dcxtro»e.  We  are  M,  Iherefon:,  to  infitr  that  the  ehiu>][«  of 
h'lye>>;^'n  into  ^iigar,  which  appears  to  f^  on  al\vr  death  is  carried  out  by 
Bouie  ftftion  of  the  liver,  proiiably  of  tne  hejMtic  cell  itself,  wliieh  is  duns 
away  with  by  a  lem])eralure  of  10O'  C,  but  wlitch  is  not  the  aelicui  of  a 
fenoent  ca|vahle  of  Iwinj;  ijtoluled, 

$496.  \Vk  have  used  above  the  iihrase  "well-fed  "animal  because  ihi 
luuuunt  of  i;lycDj|{;vn  present  in  the  liver  of  an  animal  at  any  one  tiimi  i* 
verv  variable,  and  especially  detiendeiil  on  the  amount  and  luitnrv  of  the 
fiMNl  previously  taken,  When  all  I'nod  U  withheld  from  an  animal  t)Mt  uiyoo- 
jlta  in  the  liver  ilimiiiiBlics.  rapMlvai  6r<t.  but  inure  slowly  a(\<^rwiirf  I.  T.vua 
atWr  Kome  days'  :i(arviiti<>n  n  nmnil  i|Uttntity  i*  fre<|uently  still  Imind  ;  but  id 
rabbits,  at  all  evenio,  the  whoU;  mar  eventually  ilioapjiettr. 

If  an  animal,  advi  having  btinu  starved  until  iln  liver  may  be  iMsumed  (o 
bo  free,  or  alnioHl  frwi,  from  (tlyoogen,  be  fVit  on  a  dirt  rich  in  iiarlxihydmtta 
oron  uni<  ooiiiii.ittng  exctuvivdy  of  rwrhohydniloe,  tW  lis'Or  will  in  a  short  tiiae 
he  found  lorontninn  vcrv  lRi>n^(|iianti(y  uf  glyco^i.  Obviously  the  prosenos 
of  rarbohyd ratios  in  fixid  ItaiiU  to  an  nccuniiilation  of  ulyeogiMi  in  the  lirer; 
and  thi>  is  true  both  of  Htan^b  awl  of  dextrin  and  oi  the  various  lorias  of 
sii^nr.  cane,  )!ra|>^-,  and  milk  <mgar.  The  efli-cl  mav  Iw  ipiilr  a  rapid  one,  fur 
tflyuop'n  hiM  lieeti  fi)ond  in  the  liver  in  conniilcrahln  •joiinlity  nilhin  a  few 
boors  alWr  the  introduction  of  suj^rinto  tlm  alimentary  canal  of  a  starviny 
animal. 

If  an  unitniil  similarly  i>tiirvtHl  be  fed  on  an  exclusi\'ely  meat  diet  a  cer- 
tain amount  ufglyco;^n  is  found  in  the  liviv.     This  apjiears  to  be  specially 


J 


I  uitli  llie  <l»)^  ({)r<il»i)ily  uiili  <itlivr  (-iiriiivonmiiiinitiiitl*  iil*»\  iiiiil  in 
Kurk.i  oil  ibtHuliji-i't  iIkm-oiikIiiiiI  [.nwwtci.'  "f  ({Iv<'<»g<tn  in  the  livcreof 
<ii>^  M  •111  ni««t  nni>  rv^iiniiil  hi>  mi  iRi|iQrWfit  tii(ii<:iit)<>ii  of  Uii*  tnriiintiou 
within  lliv  WIv  of  Diiii-iiitrnjirii-nii'  from  nilMp^oii*  m(it«-riiil.  But  in  tlie  tint 
place,  llw  <juniilily  oj'glyi-ipp-ii  lhii«  stoivil  ti|>  in  tlic  livi.T  t»  thi-  rwiilt  of  h 
nieiit  diet  w  much  I«w  ihsn  [lint  urhidi  fotliKr*  u|ioii  n  iiii')K>-hyilnit«  diet ; 
atid  ii)  the  eec»nd  I'Iiim,  ordinurv  nx-iil,  tvpcriHlly  li<>t«i-th>l)  on  which  di>|i:9 
in  such  exp«rinient«  arc  usimlly  hii,  conliiiiii^  in  itm-lf^^  l>2.i  ii  c^riuin  aniinJiit 
dcher  of  glvcogen  or  mmv  Ibmi  «f'  Kiii^iir.  Mon-ovcr.  when  unimnla  are  fiMJ 
iKit  on  mem,  but  on  purified  proteid,  ouch  »»  fibnii.  oii«(>iii.  <:ir  albumin,  the 
<|uan(ilv  uf  ^lyco^^^D  in  the  liver  becomes  still  sinnllcr,  though,  flccuniin)^  to 
imMl  observers,  reniainiDj;  grMt«r  than  during  iitarvaiion.  We  may  iiifiT, 
lh«rof<>re.  thai  part  of  the  glycogen  which  nppoar*  in  the  liver  after  a  meat 
dwt  i*  n.-a\W  due  to  carbohydtau  tnnterials  prewnt  in  the  meal,  Fan.hiiw- 
<'ver,  Would  ap|>ear  to  be  the  result  of  ihe  actual  pnrtcid  food  ;  ami  we  lunu 
•imilar  evid<-uce  that  ^laiin  lakea  as  food  leads  to  Ihe  formalii>ii  of  m>mt 
glycug«n  ill  tb^  liver.  Uut  in  this  respect  these  nitrogenoua  sutmtamH.'?  (M 
far  ttiort  (»f  carboUydnile  niatarial. 

With  rsgard  Ui  nits,  all  i)l»ervers  are  Sf^md  tbut  these  lead  to  no  rocu- 
iniiInli<Hi  "f  glycotteii  iu  ih«  liver;  au  animal  ted  on  an  exclufii\-ely  fatty 
di<-t  liaM  no  nmm  KJyi^ogeD  in  ila  liver  than  a  starving  animal. 

HcDoe  uf  tli«  tn>«egnat  olasKs  of  fuod-Bluflb  the  cMrbiihydriili-n  iland  out 
pruniiiwDlly  a*  the  niHtancoi  whiob  taken  »  food  lead  Iu  au  aivunuilninliim 
of  f;lyoogm  in  tli«  ]iv«r.  Wi?  may  remnrk  that  the  tfreattvl  accumulation 
of  givcngi-n  i*  ttflhTicd  not  by  a  pure  curbii hydrate  diet,  but  by  a  mixed  diet 
rich  in  a>rlwhydrat«.  A  i|UBniily  of  carbohydrate  mixed  with  a  certain 
pro]M)rtiui)  of  protoid  give*  ri»u  to  a  larger  iimuuni  of  iilyMigcn  in  the  liver 
than  the  saroo  quanlity  of  mrlioliydrate  i^ivei)  by  iu«lf:  luid  it  is  praiiiblo 
that  the  prwcm-e  of  an  appropriate  qunntiiy  «f  I'at  Hiill  fiirth<-r  amiets  ihe 
accumulation.  Itiil  lhi«  nviilt  pmbably  <)e|>endi>.  iu  )>»rt  nl  k-n»t.  on  the 
fact  thai,  ihuugh  iHH«-rcRcx«  mny  lie  met  with  iu  dilffri'ut  iuiini:iU,  a  mixture 
of  the  several  i-liuscs  of  fiKidstuHlt  i;>  mon;  rrudilr  dif^rKicd.  ivsuliing  in 
niore  Dutritive  niiitcrial  l>cing  tbn>wii  upon  ihi-  bhHxl,  than  is  a  meal  consist- 
ing axolusivety  of  one  kind  of  f<>od'RtuH'  uloiii^ 

Aa  far  as  we  know  at  present  the  glycogen  which  |]iiit>  appears  in  the  liver 
W  the  result  of  feedinj'  either  with  any  of  the  variotii>  lorm*  of  carbohydrnlni 
or  with  proieids  or  with  other  ^ubstniicvs,  is  of  (he  Name  kind  and  prettenis 
tlw  Name  characters ;  nt  least  we  have  im  evidence  to  the  conirarv. 

The  sUirioff-np  of  glycogen  iu  the  liver  i«  also  inHiienoed  by  otiier  oircutn- 
(tttneot  tliaii  the  taking  of  food.     For  inslanoc,  iu  the  fm^  an  increnne  of 

fjycngen  take*  place  during  the  niuier  month*,  hi  the  summer  months  the 
iver  of  a  fnjjc  will  be  found  to  contain  very  little  Klyco(|eD  (Fi>j.  164,  C  ■. 
unltM  tW  animal  has  been  unusually  well  fe^  ;  whereas  a  liver  exajniuMl  tu 
midnintcr  I  Fig.  iti4,  A)  will  be  found  to  contain  a  ooiisiderahle  (pmntiiy. 
oven  ibougli  uo  f^iod  bos  been  taken  for  months.  Iu  such  a  e&te  the  niat<-rial 
for  the  foriuatiou  at  the  tflyooeen  in  iJie  liver  must  have  been  furui»bt,tt  by 
some  |iart  of  thu  body  of  the  frog,  and  could  not,  as  may  be  tlie  cn>e  nbeti 
M  nwal  leoiis  immediately  to  an  increase  of  clvcojien,  be  HUpplit-il  directly 
from  the  food.  It  netMn*  as  if  iu  the  summer  tfie  fro^  live*  up  i<i  it»  ciipitill 
of  liejMtii;  glyt'oin'o,  xiH-iuIin^  it  ta  fast  aliniist  as  it  is  made,  but  that  during 
the  winter  a  'iimulity  is  fuiidir<)tu  provide  for  the  demnndi  of  the  lale  uinlvr 
and  early  spring. 

Thii^  winter  Kf  >rage  of  bcgwtio  glv«>{[cn  in  the  fm^  •ecm*  closely  de|>vn- 
ilenl  «n  tempi-rnturc.  If  a  winter  Img,  whoae  lii,-«r  m  pi-nxiiuabty  uk^tc  nr 
l«tn  loaded  with  glycogen,  Iw  expoaMl  IW  iti>m«  time  to  u  lempflmturv  uf  'iO° 


884 


TnS    MBTAIIULIC   l'B0Cg98K9  OF   THK    HOI>V. 


«ii4l  «l)  we  nro  ixMiiiK  <»  that  name  of  th«  ninUirul  It  ntnr  Hmiiuc  luf  EmU, 
«ii(l  ibal  thr  iittT  which  il  miiv  ni»kif  of  it  in  lu  iriHriiifiitrdire  fut. 

$464.  Gl]'rn|{i>ii  U  fiiunrl  m  otlivr  pnrbi  of  lti«  iHnly  iltitii  llii*  Itvvr,  MkI  i 
ti|ii(ty  of  t)K'  rnt^.-i  rcliKinj;  lo  tlif  prcw-not  nf  givtvwou  ii)  otltt-r  tiarua  trill 
1h>1|i  111  (i>  ti  tnic  <vmiv{iliiiii  iif  tlit-  [KirpiiM*  of  tat>  mf<kt\c  elycn^Mi.  NuEt 
to  iW  liver,  till'  KkiOotiil  niiiM'ltiw  iiri'  jicrhiipx  lh<-  mmt  ri]ni'|>icuoiifl  glyoOfno 
liolilcra.  S.)  l>i-i|ii«nilr  in  gly<»)r''ii  f.iiiinl  in  inii<«ti-  ihiit  il  may  ho  Kf^rM 
It!  nil  oHiiurj  though  iwt  itn  iiivurinlilr  ron*iiUi<.-iit  of  (hm  tWue:  indvtd 
il  tiiiir  aliaoft  be  concMfn-il  ii»  u  oixiMiliinit  of  nII  oniitriu-tik-  tiuuM.  TIm 
(]iiiintitr  \*iiri<:«  very  Inr^ly  hi>ih  in  the  diflerant  maotW  of  the  Mine  aniaal 
nnd  oormponilin};  miiRd«i  of  ditlt.<reDt  knitnnh.  It  diMpponre.  ii('o»nliii|t 
to  •om«  obwrven,  rmillly  npoo  »tnr\'»tioii,  even  Itefore  llii'  hcpalio  i;ly<.-u):«D 
iM9xbauflt«d;  but  nil  ikliFprrere  are  not  agreed  on  ihis  )Mint,  aitd  in  soiiw 
mu«cles,  at  leasl,  il  a])pears  to  be  rctHined  for  a  very  loiiit  tinie.  It  it  aai'i 
to  be  iocmued  in  (|uanlity  when  the  nerve  of  the  muscle  is  divided,  and  th« 
inuicle  tbtia  brought  into  a  stale  of  quieacence.  On  the  other  hand  it 
diniinishea  or  even  diaapp««n,  beiiix  appareutlj  convertei)  iutt>  tloxinve, 
wlien  ilie  mnscle  enters  into  rijpir  mortis  Some  ohMrrera  hnve  toiind  that 
it  diminblies  during  leuinus,  and  maintain  that  it.  after  coiirerdion  into  d*i- 
trose.  is  nweit  ii|>  in  tlte  »ci  uf  ointniclion,  forniiux  tlmxigh  its  oxidniioii  tW 
imnkediatc  supply  of  ihn  euerfty  set  free  in  the  ivHilradiim.  lint  even  j^nuH- 
inv  tbat  the  glvcoi^n  in  a  mu«('le  may  l>e  dimini*hi>d  duriiiji  jirutnn^ 
labor,  ft  caaitoi  W  uiimilted  ihut  tin?  oxidntion  i>r  itlbttr  chemu-Hl  rhange  i^ 
glyoogen  it  h  nm'MMtry  jmrl  of  th<-  onliiiarv  nHrtabollHin  uf  a  itiiinnilnr  ma- 
traotlAn,  Ninrv  niniiy  miiii'lri<  wlmlly  fni-  imni  gtyno^-n  are  |M'rlectly  wall 
nhic  t«  carry  on  loiig'i-imlinui-'l  c>ntrni'lii>iii<, 

Anotlier  view  of  the  uw  of  jflyco^u  in  muticle  is  mijj^i'sIiiI  hy  (he  6m 
that  uiidi'vclopoil  cmbryonii-  iiiui.('li?>  are  (iccnlinrl}'  rieh  in  glviMgcii,  In  ■ 
young  embryo,  at  the  time  whi'U  thi^  miwcular  subaUtnco,  tbotigb  undergiMBg 
Mtriation,  is  slill  largely  "  pmtoplnsmic  "  in  nature,  the  quaiitily  of  glycogw 
prearnt  i»  enormous:  >t  fnxjuently  amounts  to  40  per  mnL  of  the  ^)rv  mat^ 
rial.  At  this  period  the  hepatic  cells  are  immature  and  very  little  glyeo;^ 
in  present  in  tlieni.  Ijiiler  on,  as  llie  muKlee  become  more  wholly  8trial«d. 
the  itlyeogeD  largely  diMp pears  from  tlie  muscle,  and  very  aoon  afterwanl 
liegins  to  l>e  stored  up  in  llie  liver. 

The  meaning  of  this  can  hardly  he  mistaken.  The  glvcogen  in  the  Emma- 
ture  niu«c:)e  h  a  Hon  of  carbohydrate  material,  laid  di^wn  on  tlte  s|mK.  uhI 
ready  at  onee  to  lie  used  in  what  we  may  prubably  eall  the  fterce  ineMboUe 
MruEKle  by  whioh  the  simple  protoplasmio  cell  aubatanee  uf  the  rudtnMHt 
of  tne  niuttcutar  fibre  ix  intust^irmed  into  the  highly  diDerenliated  striated 
ODnlraeule  suhsiaiHe.  And  ne  nhall  pmliably  not  err  in  eAi»idering  lb« 
glyeoRtm  of  tlie  inatiire  muscle  fi  hobi  a  similar  [Mtition ;  it  ia  carlwhydrM* 
malertal  Motml  up  <>n  the  vjxit,  a  local  branch  ko  t«  s|ieak  of  llie  great  carbo- 
liydniin  bsnic.  It  i>  diwlined  t4)  become  part  of  the  eontnictile  aillutanco, 
atxl  a*  Mtrh  will  coutribnte  fi  the  energy  Ml  free  in  a  museular  cnntrae- 
tion ;  bill  its  euMvy  b  only  available  in  ttiis  way  afti-r  ii  hii»  undergone  Um 
neoeaMry  nteiabAium  and  become  tnrt  of  inusi'nliir  suhiiance:  it  cannot  br 
fire<)  <i€  in  a  wntrnclion  while  it  lies  as  raw  glyc-igi'ii.  or  even  at  d^-Kiri"?. 
in  the  interstices  of  the  muMuIar  tibre.  We  have  aln-adv  tiHT}  iliscuu 
in  part  the  metabolism  of  "  coutraotile  sulMtWico."  and  shall  probably  ngi 
relum  to  il  Inter  on. 

i  4fiS.  Olyeogen  may  alsit  be  found  in  oonsidenible  i)iiantity  in  the  pb* 
centa.  Here,  as  we  shall  see  in  the  latter  part  of  lliis  work,  it  is  laid  dnwn 
in  epithelial  cells  which  lie  on  tlie  boundary  between  the  mnleninl  and  die 


TBK    UISTOBT   OF   OLVCOflKX. 


58S 


I 


» 


I 


» 
I 


I 

I 


feul  tiin»«.     Am)  Wrc  Iim>  there  can  bu  lililc  iloubt  tbni  it  iii  a  More  of 
cwbohyitrnte  tiiali-rm)  tor  tin-  oourinlnnnit  "t'thc  fftii*. 

It  linn  «li"i  liwn  fuiind  in  Icucocytw.  in  oiiMiliijp-  fiirpiii-clw.  wpccinlly  in 
lliodc  liirg«  rii|ii'iiy  gfwing  iind  mpiHIj-  iiiiiltiiilyin^'  i-nrtilnpc  oorfiiutdw 
viliici)  lie  in  till?  iHilor  xvneof  fiiHocbondrnl  owifii-iition,  iiiii)  In  ntbi-r  oituu- 
tion*.  In  casM  of  'linbet<v,  whcro  the  body  is  wverlondwl  nilh  oiirbohv- 
(Irate  mat'.-riitl.  it  hiv  been  found  in  considerable  qunntity  in  the  trslio.  iii 
tlif  bruin  and  cWnhere.  Its  occurrence  in  these  Hitiiatioii*,  and  under  tbo"v 
('iroiin^tnnccf',  may  be  feKsrd>^  b#  addiliimnl  evidence  of  the  truth  of  the 
view  which  vre  hai'e  expounded  above  that  the  main  purpose  of  the  dcprwi- 
tion  of  glycoi^n  h  to  aSurd  a  store,  either  ;;enerat  or  local,  of  carbohydrate 
material,  ^ihich  can  be  packed  awar  niihotit  much  trouble  go  ling  tg  it 
mnains  glycogen,  but  which  cnu  he  drawn  U|wn  aa  a  source  of  soluble  cir- 
culatiiig  BUgar  whenever  the  needs  of  this  or  that  tiaaue  demand  it.  Ii  thus 
forma  a  verv  complete  analoguo  to  th«  vegelabk  starch,  and  fitly  earus  the 
oauM  of  aniDuil  Mtarcb. 

We  have  »<>me  reastons  for  thinking  that  there  are  wreral  rarieliea  of 
glyo^n.  and  that  llxi  gtycogi-n  which  vxititu  in  iiiihcIc  ii«  not  quite  identical 
with  that  which  oceure  id  the  liver.  Inde^l  ihcrt'  h'i-iii  I<>  tic  ioiemieilinte 
stn^cen  Wlwn-n  glyc<^n  and  March  or  dextrin.  Tin-  phyiinloj^ii-al  valiii-  of 
tliese  dillrrvnci^ii  has  not  yet,  however,  been  dourly  clcif^rtninrd,  an<l.  with 
tltb  vautiiin.  wc  may  continue  to  »{teftk  of  glycogen  m  a  single  ruImuuicc. 

Dittlifitv. 

!l  466.  Natural  diabetes  is  a  dlsence  chBrac(criH*d  by  the  appearance  of  a 
Inrg4-  i|UBiility  of  wigar  in  the  urine,  due.  a#  ire  have  already  said,  ti>  the 
prawiicc  of  an  abnormal  'pianlily  of  su^r  io  tbe  blood.  Into  the  [Mth- 
ology  of  the  various  forms  of  this  diwase  it  is  im])o«ihle  to  enter  hero ;  but 
a  temporary  diabetes,  the  appearance  for  a  while  of  a  large<)iiaDiity  of  sugar 
to  tbe  tirioe,  may  he  artificially  produced  in  animals  in  several  wavfl. 

If  the  meilutia  oblooj.'aiA  of  a  well-fed  rabbit  be  pnuclured  in  the  region 
which  we  have  previously  denorihed  (j  176)  as  that  of  the  vasomotor  centre 
(the  area  marke<i  out  as  the  "diabetic  arvn  aj^reeing  very  ol'wely  with  that 
defineil  BA  the  Taaniuotor  area),  llwugb  (he  animal  need  »i>t  neoeasarily  be 
in  any  other  way  obviously  aflt^cled  bir  tbe  ojieralion,  ila  urine  will  be  found, 
in  an  hour  or  tiro,  or  even  Itw.  tu  he  inereiued  in  amount  and  to  ooatain  A 
CMiiuderahle  ipiantity  of  sugar.  A  little  later  tbe  ituantity  of  sugar  wilt 
have  reached  a  ninximuni,  alUr  which  it  decline*,  and  in  a  day  or  two,  or 
even  le«i>,  tht'  urino  will  be  again  jx'rfrt^tly  normal.  The  better  fe<)  the 
aititual.  or,  more  exacily,  tht-  ricluT  in  glri-ogcii  lli<-  livi-r,  at  the  time  of  the 
oijeration,  the  gniati'r  the  amount  of  sugar.  If  the  animal  ha  previously 
i>larvifl  Ml  ihat  the  liver  mnlainn  little  or  no  glycoj^n,  the  nrintr  will  after 
the  oiM-ralion  c-niliiin  little  or  »o  «iigar.  It  u  cldr  that  the  urinary  nugiir 
of  Ihin  form  of  artificial  dinhctcn  comet  from  the  glycogen  of  the  liver. 
The  puncture  of  the  modulla  cau«e«  wich  a  chnngc  in  the  liver  thai  the  prtr- 
vioiuly  etiircl  up  glycogen  disap]>cnnt.  and  tht^  liloiid  hucDmc*  loadud  with 
sugar,  much  if  not  all  of  which  paixcs  away  by  lh«<  urine.  In  the  alMCnc* 
of  any  pn>of  to  the  contrary,  we  may  assume  that  in  this  form  of  nrtilieial 
diabeicfl  tlie  glycogen  previously  present  in  iho  liver  becomes  onvcKed  into 
sugar,  jitsi  as  we  know  that  it  doe>  become  so  converted  by  p^wt-morlvm 
cbangea.  Tlie  glycogenic  ftinctiou  of  the  liver  i*.  therefore,  subject  to  the 
itiflueuce  of  the  nervous  aysteni,  and  in  particular  to  the  ioHuencc  of  a 
rt-gion  of  the  cerebri i-sfriual  centre  which  we  already  know  as  the  vasomotor 
cvotre,  or  at  lenit  i>f  n  pari  of  lhat  region. 


58U  THK    METABOLIC    PKOCKSiES    OF    THE    BODY. 

Before  we  atlenipC  to  discuss  tliid  itervuua  iiiHiience  we  must  sav  a  few 
words  oil  tlie  nerves  of  the  liver. 

^  467.  Tlie  liver  U  supplied  with  nervea  from  the  hepatic  plexus,  ivbivh 
passes  into  llie  liver  nt  the  porta  ami  niuiiing  in  the  jwrtal  chiibI  with  tbe 
hepatic  artery  aiul  ^rtal  vein,  ia  liistribued  to  various  parts  of  the  orgiui. 
This  plexus,  which  is  the  only  nerve  supply  to  the  liver,  eonskta  partly  of 
medullate<l  niid  partly  of  iiou-iiiedullateil  fibres,  aud  is  an  extensioti  of  tbe 
great  sciliir  plexus  already  often  mentioned.  Into  that  plexus  as  we  have 
already  seen  the  right  (]Kisterior)  vagus  sends  the  greater  part  of  its  fibres, 
and  in  that  ple?[us  both  the  abdominal  splanchnic  nerves,  major  and  minor, 
end,  on  Iwth  sides  of  the  body.  The  letl  (anterior)  vagus  forms  slight  con- 
nections only  with  the  solar  plexus  but  sends  ott  a  very  distinct  branch 
directly  to  the  hepatic  plexus.  The  liver,  therefore,  has  nervous  coiioection 
with  the  ceninil  nervous  system  by  both  vagus  nerves  and  by  the  (abdomi- 
nal) splanchnic  nerves.  Besides  this  other  nerve-fibres  find  their  way  through 
the  s|>lanchnic  sym|iathetic  chain,  or  possibly  otherwise,  to  the  solar  plexus 
from  the  spinal  cord  without  taking  part  in  either  of  the  splanchnic  nerves; 
and  these  may  perhaps  join  tbe  hepatic  plexus. 

Concerning  the  destination  of  the  fibres  of  the  hepatic  plexus  within  the 
liver  we  know  little  or  nothing  definitely.  Some  undoubtedly  supply  the 
hepatic  artery  and  its  branches  ;  but  we  cannot  at  present  say  what  propor- 
tion of  the  whole  number  of  fibres  end  in  this  way.  Some  again  are  destined 
for  the  bile  ducts,  luid  before  tlie  plexus  passcii  into  the  liver  it  sends  fibres 
to  the  gall-bladder ;  ibcse  ]>robnbly  end  in  the  muscular  coats  of  these  organs. 
Whether  any  of  the  nerve-fibres  end  iti  the  remarkably  muscular  coats  of 
the  ])ortal  vein,  or  whetlicr,  ad  theoretical  reasons  would  |>erhaps  lead  us  to 
supiHttte,  some  are  cimnected  with  the  hepatic  cells  we  do  not  for  certain 
know,  though  some  olwcrvcrs  have  claimed  to  have  traced  nerve-fibres 
directy  into  the  hepatic  cells. 

S  4o8.  With  regard  to  the  exact  nature  of  the  influence  started  by  the 
puncture  of  the  mednlhi,  and  the  path  bv  which  that  influence  reaches  the 
liver,  our  informaliun  is  at  jiresent  vorv  imjierfecl.  One  thing  seems  clear, 
viz.,  that  the  inHnence  in  ipie^tion  is  not  carried  down  by  the  main  vi^s 
trunks:  for  not  unly  has  the  section  of  both  these  nerves  in  the  neck  nn 
marked  eHect  in  the  way  of  producing  diabetes;  but  the  "diabetic  punc- 
ture" of  tbe  medulla  obli)ugutii  is  as  efticieiit  afh'r  <livision  of  both  vagus 
nerves  as  bcf'nre.  ^^(.'eing  linw  cluse  to  or  almost  identical  with  the  vasomotor 
centre  U  the  dialietic  centre  if  we  mav  use  the  phrase,  it  seems  natural  to 
supfiosc  that  tbe  undue  conversi<in  of  glycogen  into  sugar  which  follows  tbe 
puncture  is  the  result  of  some  viiaomotor  ilisturbaiice  in  tlie  liver,  for  instance 
diliiliun  of  the  hepatic  aitery.  But  we  Inive  no  clear  proof  that  this  is  the 
true  exjtlamilioii.  ami.  indeed,  it'  ihc  |dienomena  arc  the  result  of  the  failure 
of  normal  vasii-coiislrictor  iuipulscs,  thiBe  impulses  do  not  reach  the  liver 
by  the  Irnct  which  we  .•should  su|)posc  iheiii  naturally  to  take,  viz.,  from  the 
va'^o -constrictor  regimi  of  the  cord  through  the  splimchnic  nerves,  for  division 
of  the  i-planclinic  ncivcs  even  on  buih  sides  docs  not  cause  diabetes.  More- 
over, that  the  effects  are  nnt  due  to  vaso-dil,itor  resulls  is  shown  by  the  fact 
that  strychnine  poismiing  |)Miduces  diabetes  in  frogs,  and  produces  it  by 
rapidly  hu  riving  into  sugar  the  hejiiitic  store  of  glycogen.  Now  in  strychnine 
iMiisiiniiig  the  liiiHidve^^sels  are  constricted,  not  dilntcii.  their  mu.-icular  fibres 
like  the  skeletal  muscles  being  tlirown  into  contractiiin  )>y  tbe  action  of  the 
poison. 

The  vascular  relations  of  the  liver  are  it  is  true  peculiar,  the  small  hepatic 
artery  contrastiiit'  with  the  wide  portal  vein ;  ami  it  may  be  tliat  the  dialwtic 
effects  are  contingent  not  so  much  on  the  absolute  account  of  constricfion  or 


TUB    HISTORY   OF  OLVCOOEK. 


687 


I 


I 


I 


■liinliuii  or  lh«  liF]>iitic  nrtm-,  ss  nn  ihe  neUliim  of  thu  How  tlinxigli  that 
nrtcrr  to  ih«  lloir  tliri>U);)i  the  portal  veiu.  lti<)ved,  in  xuppurt  of  this  riow 
limy  Iw  adduced  the  Untement  tliai  seclioii  of  bath  gpUitchnic  ii«rv»  uot 
uiilj  does  iiot  CHUBC  dinbi-ies.  hut  ptvvtnu  ihi*  iimiiiiI  rlTccli*  of  tlie  dinWtio 
puncture:  sod  Ihia  hiu  be«n  inti^rprvtcd  lut  ithowiiij;  thitt  l\u:  incntmni  |M>rlnl 
Ruir  thus  induced  counierlwiliitKxv  tlitr  (rifi-cL-i  i?f  dilation  iif  tho  hi^Mtio  itrtery. 
Uiit  we  have  at  present  nu  exact  iiifiirtiiali<iii.  Hiid  liictn  i»  lu  y«t  Dothing 
distinctly  to  DdKiitivi:  the  vi«vf  that  in  thin  arlifioini  iliatwli»i  tlw  oervmi* 
iaSu«ace  is  bmu^-ht  in  1i(«r  <>n  thi-  hi.'jintic  ixll  itMrlf. 

Tli#re  ai*  siHoe  facta  which  noom  In  »liow  that  the  path  of  ihiit  nurx-ogit 
inRiieiic«  uti  ilH  •any  Ut  ihe  lircr  from  the  »pinal  uDhl  pnmn  ibiMiigh  tho  lint 
tbonidt-  (ranv''""-  fC«iiKltt>ii  Mt^llatuin  ;  hut  hoirU  mchn  the  hepntic  pluxu» 
from  thL->  ^«ij;liuii  a  vriv>ll_r  unknown. 

§  468.  A  icuipfran-  'Iiaiict<»  may  be  brouj^lit  about  by  tho  admini'lnition 
nf  the  viibManit:  phloriiUin.  This,  however,  i»  a  gluoo«ide,  and  part  of  Iht- 
Rugar  which  apprnn  in  the  urine,  vft«r  a  deee  of  it,  may  como  airect  from 
tbc  drug  iucll ;  Uil  tho  quantity  of  tugnr  dischnrK^d  U  too  great  tu  bo 
BCC4>uo(«]  for  in  thi«  way.  and  eimilar  iljflljetie  effecld  are  produced  by  iho 
ndministrntion  of  pblorctin,  a  derivaie  of  phloridzin,  not  a  gluooside,  and 
not  giving  riac  to  sugar  by  its  own  dectmi position.  The  »U|tar  which  apixuire 
in  the  urine  after  u  dose  of  ihia  aub^taiice  atietoa  to  coqm:  in  part  at  Irast 
from  the  hepatic  store  of  )>tyco|{en  when  that  b  present;  but  the  druj{  will 
fpre  rise  to  Higar  in  the  urine  of  starving  aniraals,  from  wboee  Itrere  land 
other  tisMiee)  glycogen  is  prwumahly  ahwnt.  In  iiuch  camr^  the  drug  appears, 
in  wnio  way  or  oth«r,  to  either  >tir  up  th«  hepatic  aWa  to  a  maniifactufe  of 
of  sugar  (and  this  fact  is  worth  remembering  in  relation  to  llie  discuKUvn 
which  we  lately  entered  into  ( j  Mi'l),  na  to  the  nature  of  the  formation  of 
glycoiien )  or  to  produce  sugar  out  of  some  of  the  othor  tiaMiw  of  the  bodr. 

Artificial  iliatirtts  u  alwo  a  prominent  Kvin|ii<ini  of  urari  poisoning.  Tnis 
■•  not  due  to  the  arliticial  rapiration,  which  i*  had  recourM)  lo  in  order  to 
k««p  tbtt  urariaetl  aiiimaU  ativo :  Wcmisc.  ih<>ii);h  dimirbitnott  of  thu  renpira- 
tory  functions  sufliciitnt  toiiit^TfcnT  with  the  hcjuilic  circulation  may  pr(«luce 
sugjir  I»  the  urinr.  arlilicinl  rci>;>irnlion  may  with  caru  Iw  carriwl  on  wlthiitit 
any  Kugar  making  ilM  apjitatmncc.  Moreom'r,  urari  cniiws  diabotM  in  fmgs, 
althotigh  in  IhnH-  animals  rapiration  c*B  ht  sntisfactotily  cnrrinl  ou  willioul 
any  Milmonon'  rvc^piratory  moToments,  Th«  exact  way  in  whidi  tbil  form 
of  diabeUv  is  brought  about  has  uot  y«t  been  clearly  made  out. 

A  nty  rimilar  uinbet«s  ia  Been  in  carbonic  oxide  poisoning;  nnil  is  one  of 
tbe  reaultB  of  a  sufficient  doae  of  morphia,  of  nmyl-nitrate  and  of  soino  other 
druse. 

Tnere  can  b«  no  doubt  ibat  in  diabetes,  arising  front  nluitev«r  eatuo.  lli« 
wigar  appears  in  the  urine  because  lli«  blood  ooatains  more  sugar  than  usual. 
Themtem  can  only  dispone  (either  by  oxidation,  or  as  seems  more  probable 
in  other  ways)  of  a  certain  <piantity  uf  sugar  in  a  ceriain  time.  Su^ar 
injcct«<l  into  the  jugular  vein  r«api)««ra  in  tlw  urine  irbenever  tiie  injectioD 
Ix-oomoA  so  rapid  that  tbe  percentage  of  sugar  in  the  bloul  reaebee  a  oerlwu 
(Inw)  limit.  Su^jnir  in  tbe  uHnt  nienii.'t  an  exoras  of  sugar  in  the  blood,  How 
in  natural  iliatteti-n  lluit  excna  ari:4--H  litta  not  at  prment  Ik^d  clearly  made 
out.  It  may  be  that  some  fornin  of  dinbeuw  rtMnible  the  artificial  diHl>e(ee 
juu  dMcrilH'd  BM  rcnultiiij^  from  iiunctun.*  of  the  medulla,  and  arise  from  a 
t<M  rapiil  conversion  of  tlKi  lupatic  glyoogen,  or  from  carbohydrate  nuilerial 
(iiilijig  to  bo  Hlored  un  a«  givcogi-n.'or  from  lui  exoonlvc  nuinufa<;ture  of 
(■arbonydralc  mnlerial  by  the  ^'jiatic  cells.  All  fornw  of  diabeies,  however, 
cannot  Ik  Mtisfnctorily  exjilninvd  in  ihiHnav;  and  it  lias  U-cii  fiiggtsieft. 
iboiigh  adeijuate  proof  has  not  yet  been  su|>plie<l,  that  tbc  sugar  of  diabetes 


383 


TDK    METABOLrc    PROCESSES  OV   THE    BOUT. 


IB  iif  a  peeiiliur  nnlurc!  iiml  iici'iimiilittfti  in  tho  bluod  because  It  U  i 
ncderjto  ibi^i-  i-hiiiigi'Ti,  wlintrvrr  thr_r  Ix!,  vthioh  facfull  ttic  uurraal  at^  o 
the  blKod.  VVi'  c-Jiiiiiot  b<'ri>  iliscuw  ih<-  subject  in  dcuil ;  liut  tb«re  ia  taoes' 
to  be  Miiil  in  tiivnr  nf  thv  v'luvi  iJiiil  th<?  witrom  nf  the  cxi'M*  of  Kiiipv  >>>  tks 
bloiHl  iniij  111-  varimit,  fttiii  hcnt'o  ihnt  Kcvcnil  ilistiiu-t  variclicii  of  iliab«c.« 
urny  exWu  In  wvcro  cyiwa  of  dinbolcs  tlip  nbcrrniit  nstiirc  of  ihi"  mrtaW*  i 
which  is  piiiig  on  in  mmv  or  other  of  the  tissues  of  thp  body  U  «b»wii  bv  ifc- 
aiiliriirntRi?  of  iibnorniiil  sulMtMncce  in  the  urine.    Thus  arctone  )■  frctuatt  1 

IirowoDl.  nml  the  liila]  iRsiit?  of  certain  cSAes  has  been  attribnted  1o  pnuoniL 
<Y  tbiit  snb§lnDce:  uxybutyric  acid  and  other  Tsrious  orffttoic,  chictlr  vol  - 
tik,  nci<ls  are  also  Bometiaiee  prttenl.  But  in  re&ped  to  theM  Moa  otW 
abnormal  bodies  vm  are  not  at  praeul  clear  wlieiher  they  are  lik«  the  mtM 
itself  the  i>roducIs  of  an  abnormal  inetaboltam  whiuh  ia  the  root  of  thcdS 
esse,  or  whether  they  are  senondar)*  products,  that  ia  Ui  my,  producU  of  ltd 
general  diiordered  luelabolbin  iiiductd  by  the  ciMi«iant  [ireMnce  in  the  Uoc: 
nf  an  excew  of  suear.  We  have  iilriNidy  in  diKcuwng  the  formation  of  g1~ 
cojien  cnllvi)  ntli-iilicm  t'l  the  fnt-t  that  in  vevore  cane*  of  diabelea  the  Riga 
luUBt  havi;  a  noD-aoiylarrotM  Honri'e;  and  the  fact  tliat'the  urea  b  incKUa 
(and  that  Uh>  in  mjniir  ctin*  in  rnlio  with  the  xngar)  in  dinlMtcc  mggeaU  tba 
tliu  Mignr  may  ariH-  from  protcid*  wbirh  havo  been  »|>!it  »p  into  a  nitrt^c 
noUM  (urcn)  nml  a  ni)n-nitr(iK<.*>i<>n«  moiety,  and  m  point*  out  the  utny  in  whic 
priiirids  may  be  a  »oiirc«  of  glvcogeti. 

A«  a  Mrl  of  converse  to  diabetei*  we  may  mention  that  th«  adminLitratic 
of  arsenic  in  suttic-ient  doses  or  for  an  ndc^juate  limfl  pr«Tenu  nn  oocuiauL 
tion  of  glyeogen  in  the  liver  nud  apparently  in  the  body  Kenornllr,  wbater* 
he  the  diet  need.  The  presence  of  the  metal  in  the  hepatic  cell  Mcmt  C 
prevent  the  cell  substance  fruai  manufacturing  );]yco;{eu  either  from  rarl>uhj 
drate  material  brought  to  it,  or  out  of  its  own  aubjlance.  A*  any  other  lun 
of  convenw  we  may  iilNn  ttnie  that  the  ad  mi  nisi  ration  of  f^lvcerin,  eepedall 
Ifaraugh  tho  aliinentart-  canal,  dirainiihes  th«  elTcel  of  the  diabetic  puncLun 
or  of  morphia  or  of  i^lhor  poiyniiins,  in  hurrying  nn  the  heiMUic  uore  of  gl] 
<!ogen  into  fU|fnr,  and  thus  diminishes  tho  sugar  in  the  unn«;  iht  present 
of  tb«  glyoerin  in  the  hepntic  coll  np)>onrs  to  he  in  Home  nay  a  blotlraui 
to  lbs  conversion  of  tho  glycogen  inln  sugar.  Now  glycerin  injected  inl 
the  altmentiiry  canal  nf  ■  normiil  animal  leads  to  an  ioenMc  of  KlTOoeen  '■- 
thri  liver;  and  the  viffw  v«ry  naturally  sugeesCs  itself  that  this  iiicrMi 
arising  fnm  the  glycerin  is  to  be  explained  Dy  th»  glTcerin  inbibittns  i 
si>me  WAV  a  nurmal  conversion  of  the  glycogen  storo  into  atignr  whicb 
continually  going  ou,  and  thus  increasing  for  the  time  that  stoic. 


The  Spleejc. 


4 

ooosidn 


S  470.  Tt"!  tirwrliirf  of  the  t/ilffn.  We  may  uow  uke  up  the  coos 
tion  of  tite  forraatiuii  of  the  cunnttiuenM  of  bile,  a  matter  which  in  dealii 
vilh  tho  scemtion  of  bile  (i  2't7)  we  pu«ipoued.  Of  these  conatiiueaia  t 
moft  important  are  the  "  hile-snlts"  on  the  uue  hand,  and  the  bile  pigros 
on  tIte  other.  \Vr<  will  lake  Ih?  latter  first;  but  linoe,  as  we  have  alroat 
naid  ($  26\  Ihf  bile  pigment,  bilirubin,  apiwars  to  be  derived  from  bvin 
ghibin.  and  since  the  sple«D  seems  to  br  especially  concerned  in  the  cbaag 
which  hiemoglobin  undergoes  in  the  body,  wo  must  first  turn  to  the  structu 
of  that  organ. 

WhflD  a  ffMb  spleen  is  cut  across,  the  whole  interior  witbin  tha  we 
delineil  coal  or  eapnih  (Fig.  167]  pre<eiits  the  nppearanoe  of  a  dark-r 
spougy  maaa,  iraverwd  by  irregularly  disposed  paler  bauds  or  tmbrfnlir,  mt 


A 


Thix  NtETKni  or  ^rtttx-nxf.  iiiiiiiiv  >(ji<.MriiiD,  ^ikmiwu  in*  Mods  or  <hciiii»  cif 

A  HlUI.L    V'KIM    IN  TDK    IHIKHtlKTa  OT  Tllr    I'l  tr. 

r,  lb*  Uin.  flUtil  Willi  liki>il>nir)>u>i*l<ii.  ohli-'b  an  lu  ounlliinlt;'  hIIIi  nltwn ,  M,  nllltiK  u|i  Hid 
t<BWntHm  «J  llionlinimillMiiei'r  llw  imlp:  v.  wktl  dI  IM  kLd,  The  aliiidttf  Uallo  iinittp*  IM 
'(■d  liliwd  roffaiicla  *fi>  iMkooipiiKle*.! 

IftH.]  Tlie  rciluesB  is  obviiiiBly  <Iii«  to  red  blood -carpuecles ;  and  h  U  clesr, 
U  Ui«  (lulsei.  Ibat  the  8j>l«en  ^isoetaes  au  uuuaunlly  large  supply  of  bluod, 
wliicli  iDorcover  seeina  to  be  diApoeed  iu  an  uaiisuni  uianii^r. 


MO 


THK    UETABOLIC    rHOCKSSKS    vr 


Whet)  Iiv  II  kirvum  of  uonnal  oaliiw  solutioD  driven  Ihrouj;))  iu  vcadii 
itiHcIi  IiI<3(h)  dh  in  iHtHible  U  wa^-Ued  away  from  itie  Bpkeii.  aiiil  tlw  urxui  i* 
lUlbkciiiciilly  hunlincil  in  itiK  unual  way,  prererakly  in  a  diad^iidifl  iHiiiililiuQ, 
Mclioiw  iwt^nl  ilii;  I'xllowing  ftntureH.  Tlie  njMule  omaisbt  nf  an  inttn 
lltrer  of  c<iiiiii>clivc  liwiiii-  <Hivi-nH.I  nilli  l^[IiIlll•lil>ltl  [ilatva,  rurinirig  il)i>  |<rn- 
li>unl  emit.  »ii<l  poHtinuDUM  irith  ihJN  aii  inii«r  iliM-)>t?r  Ikvit,  (iiaipntvd  of 
(■uLn«ctiv<t  ItMim  wilh  nrlitorkx  of  rliutriv  fibmt,  and  (■•>tiiniiiin>;  a  (.-cftiie 
Diimbvruf  )>iiti<lU-«  of  |>lititi  imiiwrulnr  li)t>Mf ;  tliU  ilifiMr  layi-r  uf  tfa«  ckii- 
Hilv  givra  otr  roiitKlcil  »r  tlntu-ititl  bnmlKii  ol'  tbo  Minif  iiiiliire  as  itsM, 
wlucU  p«M  ill  all  dim-'ti'ino  inUi  t\w  iuli'nor  of  tW  urgaii,  braudiiii;;  and 
Biiastomoeing  fr(i«ly;  ihuM  am  Imt  d«ri;liii)rd  lowanl  tb«>  side  nf  failm 
«hcr«  ibe  bninchue  of  ihc  spli!i)i<'  iirtcrv  miiIi  l)i«  spKtiic  iit-rvea  eulfr,  bikI 
nbeiii'o  th«  Hplcoic  voiiM  iasiie.  Tbc  inndo  of  brauoliiiin  is  irre^lat.  nutl 
the  braucheH  vnn'  in  Biz«,  Inrx^r  tralwciitii.'  (nviiig  Hm  Io  Biuallor  unii«.n 
tluit  llie  ivhule  interior  of  the  or);an  is  ilividml  iiilo  a  labyntiib  of  irngaht 
coiuiuuDioaliu^  chainben,  uhicb  cunuiu  in  the  freeb  state  the  «jilwn-pu)p 
ineniioned  above. 

Tbe  basis  of  both  csiwuId  and  trabcculn,  email  aod  jfTtat.  in  coimeclm 
tiwiie  well  funiiahed  with  elastic  eleoMots.  Iu  some  aaimxls,  a»  fur  itutaiK* 
in  ilto  dog.  tbin  Wxiii  is  n  ridilr  pn)vi<lud  wiib  plait)  muscular  tibfvs,  tiat 
IkiiIi  trabeciilie  nml  (V|iiitli!  On  its  d«ei)er  layera)  w«in  to  be  almnet  eiiliret)r 
cx>in]HiM>i)  (if  miiitciilur  tbvae.  In  other  aniinalt,  in  man  for  iii«taii<.v.  tlir 
mkui-iiUr  i,-l(;iiiL-iit«  art!  itiuuii  more  scanty.  TImi  cu|i$u1e  and  tratuvul*. 
amall  and  great,  thu.'«  fona  a  spim^like  flramework,  which  tieiitg  elaalic  cm. 
evon  in  the  cium  vhtm  tbe  muscular  fibre*  are  srniity  or  aliseDt,  at  oa* 
nomvnl  be  diKlotKtvil  mi  that  the  chainbcK  are  rajHiriiiuH,  mid  at  aniilliw 
moment  ciin  by  virluv  of  iUi  itladticitv  vlinnk  mi  that  ib«  «liainb«n  iu»  rv 
dui'c<l  in  Kixo.  In  tbe  niiimid*  in  which  niiiixitliir  fibroc  ani  abuudani  mill 
en-amr  variation*  of  mim-  are  ]Hj«iible.  When  tbe  musoivs  are  relaxnt.  a 
disli-iKline  force,  nuch  m  U  fiiriiiilicd  by  ttie  |>r(wun)  of  tlw  blood^alnuw. 
cMa  Bircir  out  the  franicnork  to  a  very  great  bulk;  and  an  adet|iinlr  ihhi- 
tnctioi)  of  the  muscular  Hliri'ti  <.-An  in  ttirii  ixiuwu)  tbo  snon^-liki'  man  inU 
Very  small  itimoiwiimfi.  A*  wc  glial!  pitvently  eoe,  rhytnraicnl  ur  i>th«r  eon- 
Iractioiia  of  the  cn|)«i,ilv  and  trubccul:>r  Inbvrinlh.  in  nniiuab  in  nliieh  iJiM 
are  Ur^fly  muscular,  do  produce  remarkable  and  imporUut  varintjoiu  b 
the  volumi*  of  the  spleen. 

!)  47L  This  s|)i>nKedikB  framevrork  of  camule  nnd  trabeculn  mniinda  dm 
of  the  structure  of  a  lymphatie  gland,  ana  the  raiemblanoe  is  carried  Mill 
furilier  bv  the  ebamben  of  the  labyrinth  beinx  occupied  by  a  ririirulu 
lU'idiDcation  of  ooniiective  titaue.  Itut  the  rmeinblnnce  is  superficial  only. 
The  chuiiiberM  marked  out  by  the  LrabeeuUe  of  tbe  »ple«-ii  am  wholly  Imgv- 
lar;  there  is  iiul,  as  in  a  lymphatic  yland,  auv  dislinclioii  )K'twc«n  a  iwrUX 
with  large  radiating  cliamben  ami  a  inetlulla  with  aiiit>lomi«in|[  luhuUr 
(^hambere ;  the  trabccnlte  are  eloteit  loHard  tbi-  hilu»,  but  olhern-iao  one  nait 
of  the  spleen,  il>  rvgardn  the  arrangement  nf  tralxMrulie.  is  tike  any  ulnar. 
Morvover,  the  n'lii:iilar  tJMiue  uvcujiying  the  chainl>en>  shoirs  n<>  di.-<Uiie4loa 
WiHceu  lyniph'sinus  nnd  f<dliclv,  is  not  exactly  like  the  line  reti<-iilum  of 
the  one  or  the  coaro:  naicuhim  of  the  other,  but  of  a  nature  distinct  from 
Mcb,  aud  hiu>  MO  vpenal  nonuuction  with  lymphatics,  but  has  peculiar  reU- 
lio«»  to  the  minniii  lil<H>dviiwl«. 

Except  at  the  while  «|ii>ts  uceumed  by  the  \falpi;;hian  oorpu*olo*,  of  whidl 
we  will  spi-ak  pnvmtly,  the  epreiiie  rcliciilnm  is  somewhat  coarse,  c<>an<«r 
than  ordinary  iidcnoid  lii^uo  (^  '2^0),  and  over  a  large  part  of  the  8ul(H>n  is 
miidc  up  of  brflnchc<l  nucleated  cells,  the  brancliiw  of  which  are  roMnbrnnuui 
and  fiauge-ltke  nthcr  than  lilameutous.    Tbi«e  flan:^  of  uciglibortog  oelU 


TU8    SI'I.EEN. 


mi 


In  wilt)  <-iu'}i  niWr,  iind  tlili*  fona  n  liilivnniliiiir  nrlwin'V,  llu'  wnllii  (if  ihi! 


iK- 


iif  which 


■I  not  I 


It  ot 


iliir  «hn'li>. 


I 


]»niuagc«  111  winch  arr  t'>rnu-< 
In  .""nut  pnrlji  nf  llu-  «|iln-ii,  howpvcr,  iIkdw  fliiiii;f-lik('  |>i-<ic'-wm  un-  rcpliioitl 
!»)■  lilin*,  mill,  thi-  Iiwlics  nod  nticlpi  nf  ihc  ciHi*.iiliKni.  ci-tts  Mnj;  nrv,  Ihe 
reliculiim  i>p)irar«  a^  n  more  oniinnry  reticulum  uf  tine  til)rL'«. 

T)i<-  )Mire  of  this  reliruliioi,  vrhrtlic^r  flang«-lik«  or  li]i«nirntouif,  nre  at  Um 
cii}^  uf  itie  trnbcculft  continuous  willi  llic  siibslanM'  uf  die  trnl)ci-ula> ;  tlie 
Bnitill«r  iratKcuhe  brvak  up  into  llie  r°liculiim.  and  llic  Inrj^r  trabectihe  are 
iVingeil  will]  piuecMee  coniinuoiis  wilh  tlio  bars  ut'  Ihe  reliculum.  Tbiia  the 
ruar^r  network  of  the  trabecular  Bjstem  is  continuous  vrilli  ibe  6&er  net- 
work of  the  reticulum. 

Tlie  n-ticuliiu  of  iJie  Irmphntie  ^land  coiit4iiR«d.  it  will  be  ronwuibered, 

Hde^  fliikj,  Icucocyteit,  ibese  betn;;  cruwdeil  iu  th«  folUck  ami  more  Kpnne 
fn  the  lyiuph-fliniuL  The  ajtlenio  rHioulum  nUo  conliiintf  )fiu<!iicTU-ii,  but 
tIiiT.-H!  arc  thrown  )Uli>  tin:  iMU^kgroiind  by  the  ]iir)i;i!  iiutubnr  nf  nxl  eorniiMilM 
\ritli  whirh  ibo  mt-Tihc*  of  the  n-tiouhirn  are  crowded.  The  n-ltculiiiu.  Id 
fact,  i*  lllli-d  with  blnod,  ami  [n'CiiIiiir  nrniii^ntunl*  qx'iA  bv  whii;h  ibe 
blood  gaiiti  ud^vM  to  the  ii{inc<4  of  th«  rdiculiiin.  Wluii  wii  »ii)ke  of  above 
M"»pT«on  pulp"  rxprvsuiil  from  the  friiih  opWn  ci>ni>isl«  ot  fragniunlx  of 
the  rMicnlum,  to^IxT  with  tli«  ml  and  white  eorptiwlv*  occupying  the 
HMshai  of  that  rr'ticulum. 

1}  472,  Tlifl  apleoic  artpriw  entering  thi>  iiiileen  at  tbt-  bilus  arc  in  Bomo 
■niiualf  ut  lir«t  mmxirtnl  by  ihi-  tnilwculu;.  id«n<;  irhirh  ihi-y  run.  dividing 
as  ihpT  go,  but  the  l>nincht»<  iil  laxl  lc«v<-  tlu'  trabt^culic  iind  nlungi>  into  the 
rvliculum.  [n  other  nnimnl"  the  artcrire  run  more  indepondcnt  of  ibe  tra- 
licculie.  Ae  iher  leave  tlw  trabeeula-,  or  toward  their  Icrininalioiis.  the 
email  arteries  are  apt  to  divide  into  pencils  of  small  twigs.  In  a  similar 
manner  the  veiu«  may  be  traced  back  along  the  trabecnlai,  small  and  great, 
along  which  they  ar«  gathered  up  from  smaller  veins  uf  Uie  reticulum  ;  but 
Ihe  veiuB  do  not  run  in  the  reticulum  as  distinot  Teaaek  to  the  same  extent 
that  tli«  aneriee  do. 

Ill  the  reticulum  tlie  minute  arleriea,  according  to  most  observers,  are  not 
ci>utiiau-Hi»  in  the  u»ual  manner  with  veins  by  meaina  of  cluwd  cnpillariefl ; 
but  a  pm-iilinr  armigemenl  i»  met  wilh.  The  epithelioid  \>\Mei  furuiiug  the 
mnillary  wall,  indlead  of  bi^iug  ceraeDt«d  together  to  fi>rm  a  continuous 
tul>ulHr  ^hiriith,  are  si-jMrate  from  e«ob  other,  i-onie  asunder  as  it  were,  aud 
lb»«  allow  ihi!  lumen  of  the  rafiillitri'  or  rather  of  the  minute  artery  to  opeu 
Dut  into  tin'  .■<pl<-nic  reticulum:  iixlt-'fl.  the  epillielioid  plat««  uu  longer  retain 
their  oimph:  i>plindlp  ihupi-,  hut  bivDrtiing  brauclieil  and  irn^utar  are  tmns- 
lornKd  into  the  ci-ll*  of  the  ix-ticiilum.  In  thi«  way  tht-  ohanncl  of  the 
liliMxlvi-tM'l  beeomi^  coniinuoii.'t  with  lli<-  Inbyrinth  of  llin  splr.iitc  reticulum  ; 
ntifl  bv  a  convert.-  jiriicCM  the  :*Him;  Inbyrinth  ix  made  i^intinnou"  with  the 
plexift'rm  b<^i»ning"  of  >mall  veins,  tlw  iw-cullci|  vcniMw  ginuvus,  which  end 
in  ihc;  veiiu*  running  along  the  irabivulie. 

Thus  ibe  blood  Howiti^  along  the  «iilcnic  arterv  twiaiicii  from  the  o|>un 
of  the  minute  nrti-riM  into  tliv  aplenic  reliciifum.  and  in  gathoro'I  up 
the  reticulum  into  the  »p<m  nioutlia  of  niinutv  vcimt.     When  the  cn|>- 

le  and  Irabcctila-  are  in  n  relaxed  ivmdition  a  n<i(  inomMilurable  portion 
nf  blouil  thus  oecapcs  into  tbc  reticulum  and  tarriiM  in  the  raiMhta,  wlier«  It 
nudergoes  olmngra  of  which  wc  nhall  prtMtutly  sjxMik;  whc«i  the  cii|i«u]e 
un<\  irabeouUe  are  contracted  and  ibninkcn,  tlie  blood  Hows  in  a  niura 
tliret't  manner  through  the  narrowed  channels  from  the  art«riM  into  tlie 
vclnn. 

§  4T3.  Tlie  lymphatic  ves^Ii  nf  the  dpWn  lire  not  very  numerous.  The 
cn|i4ult>  and  the  trabeculic  coutain  tymphiitic  pIcxiiMi  ojiening  into  lymphatic 


IJU2 


Till:    MKTAIIULIC    PKOCESKSS    tiV    THE    ItU  1)  V 


Irutika,  wbiclt  l<;av«  l)i«  lilliia  uhh  thu  bti)odv««wl«.  Tlicrc  i*,  hunrtm,  > 
roiukrkniili:  lympbatic  iluvclopfDciit,  in  tho  form  of  n  t^livuth  of  silenMi 
U•MI1^  wliich  n<v»iu|iauic0  cIh'  ariuH^i  Air  moidi.-  (tiauticv  mt  lIk-v  lc«ve  (br 
tnil)rculii-  tuiii  with  whicli  tlw  )yiii]>bHlic  vifw^ln  of  the  tmbt-culw  nre  wo- 
n«ilt*(I.  i^i  luiig  n»  tii«  aruriet  am  runiiiug  «]oiig  Uiu  Irabeculia:-  tbts  wteBoU 
flwaUi  il«ilii«r  nb<wu(  or  extrvriKiIvKaiity:  butMth«iiDor  arterini  bntac^ 
plung*  i>iU)  the  nticiiluiii,  it  is  wi  liu-nNUH-il  iii  btilk  nt  iiitorvalB,  util  f*p« 
dally  wh«rc  nil  Rrtcrv  in  0)vi<liiig  into  two,  iw  (o  form  an  uval  or  :'plirrind 
naas  Twble  to  lh«  D«kwl  vyo,  mid  coospicuoua  from  its  color  Ihvjiu*^  ibc 
Adenoid  tinue,  crowdvi]  m  usual  witU  leucocytes,  appwtra  vrEiite  or  i.iil<'rW 
OA  oompaml  niih  the  darkixtj  eplcen^ulp.  Th«i>e,  in  fiu:t,  an-  iltii  Mai- 
pighiaa  corpuscles  spokun  of  nlwve.  Each  Mal|ti);bian  ooqiuarlc  if  a  lamt 
or  leas  globular  mass  of  adciioid  ttwue,  crowded  wilJi  leuoooytiM.  >]vv«1ii)mi1 
Lp  the  aav«Dtilia  of  n  minute  artery  running  in  the  splento  n-ticuluru.  .\i 
K  rule  the  developmeDi  takes  pUce  on  one  side  of  tlie  art«ry,  so  that  tht 
rouivded  MalpiKhmo  eorpusele  seems  to  be  sitting  on  tht^  nrtvrv.  Soof 
tini«a  the  develujiinent  lakes  place  mora  or  lec«  nyularly  <iq  all  sldei  iif 
ihi^  artery,  no  that  tJie  artery  ap|)eara  to  nierx^  aud  run  thruugh  tite  imiwM 
miuK,  which  t*  then  called  not  a  MaljiiKbiaii  (uirpiivcte,  but  n  "br|Mr 
pliuc  s{Kit;"  and  not  infre<iuently  the  artery  dlvidca  in  lh«  laidilte  of  uie 
maM. 

The  adiiioid  tiwiitr.  as  eli»e»h<'re  (5  -t»0),  is  compoard  of  a  fine  reticulum 
crowdi-d  ii'ith  Icuoijcyti-n ;  ilu-  corpuscli',  in  fact,  cJoecly  rraembles  a  wilitarjr 

!;luid  of  the  inicaline  or  a  muiideil  nuuut  nf  thr  folliciitnr  subsinric^ivfa 
ymphatiu  glaad.  Bui  it  dilfrn  from  thvwc  dnictiiro  in  nut  bring  ra^ 
rounded  by  any  dintiiu-t.  lymjih  »inu«;  at  the  i-i  renin  fore  nee  l)ie  iruc  iidNoU 
tjiseue  ymm!*  vuildvnlv  into  the  ooaiwr  aplcnic  reticulum.  The  arivr}',  at  It 
puses  through  Iho  Miilpiahian  corpuscle,  nv«s  otf  to  it  lino  bniurhi-«,'wbkh 
form  a  capillary-  iiclworK  through  tlx-  adenoid  tissue,  aud  at  the  i-iroi»- 
fereiice  open  mit  into  the  htliyrinlh  of  ihe  splenic  reticulum.  Thaw-  ]ktl)- 
pigbian  corpuscles  are  so  nuineniui  that  in  a  section  of  a  fresh  aoniinl  »j)ia» 
tlie  dark-red  ground  of  the  splenic  substance  appears  quite  mottled  by 
KaaoD  of  the  white  dots.  Hence  no  incousiderabte  portion  of  the  blond 
raadiing  the  spleen  finds  its  wav  into  the  nieebee  of  the  HpK-nic  n-iiculum 
after  junwiiig  throuvh.  and,  proliabty  after  acting  upon,  aiid  being  umI 
upou  by,  Iht-  adeiiiiid  liMue  ol  a  3[atpighian  corpuscle. 

Wlial  b  known  a»  «uyo  iplrtn  is  so  oalletl  becaiiae  the-  Malpigbiaii  oorpuv 
clcs  become  en largetl  and  traiu^arent,  incoiuefjueiiceof  t)w  IrucKwyti-euDdei^ 
going  "laidaceuiu"  tiegeueration ;  the  nuiui^  chiuijce  may  ab»'af)eot  Um 
adenoiil  ^•ni«  of  the  small  arteries  and  may  even  Mprtwl  to  the  itplecn-pulp. 

^m.  The  nervn  of  the  Hple«ii  which  [iiim<  into  the  oigan  m  the  hih» 
with  thv  bloodvevelK  arv  derived  frcmi  the  »)lar  plvxus.  They  eonj^ist  rbteSy 
of  non-indullnti'd  fibre*  mingled  with  which  arc  n  few  ntetlulliiled  fibrea 
Their  tenninatiotiji  huvr  not  Ix^cn  ns  yet  exactly  made  out,  but  white  many 
presumably  are  distributed  to  tW  hl<)(id\'e(«cls,  there  can  bo  little  doubt  ibM 
some  end  iu  the  cnpsitle  a»<l  triiheculic,  at  least  where  iheee  contain  muscubr 
tia8ue,atid  thus  bring  the  contractions  of  theee  structures  under  theguidanev 
of  the  special  nervous  «yKlcm. 

The  ceutri|>e(al  courM  of  the  fibresof  these  splenic  nervos  has  not  yet  beta 
made  out  delmitely ;  we  may  perhaps  snfelr  conclude  that  the  majority  arc 
derived,  like  the  fibres  distril>uted  to  the  iKighboriug  Abdominal  orgaas. 
from  the  dorsal  spinal  oord.  That  the  vagus  also  eoniributes  fibres  i»  very 
philmhle. 

it  476.  When  the  sa-called  spleen  pulp  b  examined  under  the  mi^^oM^«M. 
it  is  found  to  consist,  besides  toe  bnDcbai  oells  and  libres  constituting  ill* 


ntCmluffl.  of  fvllf  vhlcb  may  be  detcriliei)  as  pnrtlr  recTmrS^^^^Bd  pnrtl^ 
ibilc  curjiuKln  or  l«iim>cyUft.  We  »)>ukv  at  llie  tn«>lii?<  nrVBRBuliim  am 
iMRiSllnl  with  liliiDi);  btil  it  U  olivii'Uii  ttiat  itit?  corpu»clm  of  the  blwid 
■M  BOirr  Inn  n'liililv  ibroiijfb  thu  lubyriiitl]  than  iI<m-«  llic  tltiiU  plaxma,  add 
tkn  imce  a  ranopotnilinn  of  tbu  c»q>u»'li3<  tin  ci>ii)|>iiri-d  wilb  iho  pimmii 
BWl  takv  pUc*  Ui  tbo  iii(iih«*.  Tliv  nuiiciilA  of  Iho  inttthcv  cnniiiit.  pruiwrly 
^Nakloc,  bo  CTillrtl  blmx],  but  arc  riithvr  uggn-gulioiu  of  rorpusclw  wilb  a 
nhttnly  anuUI  i)uiLotilj  of  Huid. 

n*  whit«  corpuKin  or  kucocylra  are  very  vnriout.  ^omc  aro  *inal),  lik*' 
itvtMCorTinarBlviiiphaticigland.lhvuGll  eubctiuic«  bdiig  WAnty  relatively 
U  the  nucli-iia  Oltivn  nr«  indHtingiiiflmble  from  the  ordinary  white  corpus- 
*im  of  tltc  bltMxI.  Olhcn  ngaiii  are  large,  twice  as  largo  at  an  ordinary 
■•hit*  corpitacle  or  {-vui  lai;^r  than  thi«.  |iuM(«b  nion>  than  one  ducIpu*.  and 
raiDUio  in  tbcir  rt-ll  subftanni  nunicroiis  refractive.  {>Ale  ydlow  or  colorlcas 
jcruiuli^  ^me  of  thef«  lari^er  ti:irnis.  which  lik«r  thcothcrieihibit  aiuoibaid 
•OOTWMtitB.  and  are  often  irregular  in  Ibnn,  ar«  characterized  bj-  the  pr«s- 
*tae>  in  Ihcir  cell  lubeUiDce  of  red  corpuscles.  somotiniM  in  almost  a  natural 
CVkndition.  Foiuelimes  more  or  Icn  irregular  id  shajx?  >nth  their  red  bitinu- 
K*ulitJi  cbaUj^og  iuui  the  brovtuer  btetnatiii,  and  fometimcs  disintej; rated  iuto 
*  uaM  of  brown  sraDul«L  The  fluid  or  plasma  in  which  theKcelle  float 
*1m  mataina  beucKa  Dormal  red  corjmsclaa  a  certain  number  of  red  corjius- 
*^lca  in  various  stages  of  change,  a»  uell  as  [li^ineui  i^raiiulea  which  ap{>ear 
^  be  derived  fVom  bnmoglobin.  Ubvtoualy  a  certain  number  of  red  rariius- 
Clu  do  umlergii  cliiinge  in  the  upleeii,  but  whether  the  change  in  mainly 
c&cted  in  ihi:  ctrll  >ub<UU)ce  of  tli«  celU  junt  nienlion«d,  or  takes  place  iu  tite 
plnaaim,the  pnnluctH  nfdiHinlcgratiuu  being  «ubiH>i|uei)tly  taken  up,  iu  atnu'- 
boid  fashion,  by  the  cells  in  <iueKtiun  is  irnt  as  yet  clear,  lleaidea  the  above, 
in  ibe  sple«u  uf  youue  auimaU,  nudeutcil  celU  with  hieiuoglobiu  holding 

■  cell  aubtUDce,  luemaloblaala  (xit  §  '27),  huv«  becti  d*wribed  ;  thtae  ar«  tatil 

■  tw  npl*^  si"!  iu  the  spli-cti  of  adults  aflcr  very  great  low  of  blood. 

B       $476.   TftfmuTfinrnUo/llie^lffn.     As  we  have  already  stated,  ihevolufue 
Htof  iIm  »]d«D  if  fubjccl  to  considerable  raniition». 

AfVcr  a  inral  (Ik  splc«n  iucrvaws  in  size,  reaching  its  maximum  alxHit  five 
iKMit*  aHcr  the  taking  of  food  ;  it  remains  swollen  for  some  lime,  and  then 
veCurtH  to  its  normal  bulk.  In  certain  diseases,  aiicb  as  in  the  pyrexia  alten- 
<laat  oa  certain  fevera  or  inflammations, and  more  es|M>cially  iu  ague,  a  some- 
«b«i  similnr  temporary  eulnrgemeni  takes  place.  In  prolonged  ague  a  per- 
maoetiL  hy))enrupby  uf  the  spleen,  the  so-called  ague-oake^  occura. 

The  turgesoeDce  of  tlie  spleen  seems  to  be  due  to  a  relaxation  both  of  iho 
small  arteries  and  of  the  muscular  timue  of  the  capsule  and  of  the  tnibeculu-; 
lube,  iiifact.  a  vascular  dilation  accompanied  by  a  local  intiibitiun  of  the  tonic 
ooDtracliun  of  the  other  ulain  miuuiular  libre*  euiering  into  the  structure  uf 
tlw  Dfgaa,  tbe  latter,  at  all  events  iu  «omv  animals,  heuig  probably  tlie  more 
Important  of  tbe  two.  AikI  the  rondiliiin  of  the  spleen,  like  that  uf  other 
vaM*u]ar  areas,  Bppean  to  be  n^gulutctl  by  the  central  nervous  systein,  tlw 
digaativw  turgCKeucv  being  fairly  comparable  to  the  Hushed  condition  of  the 
pDCfens  and  of  the  gaslnc  mcmhnine  iluring  their  plianeti  of  activity. 

Tba  a|>f>li<«tioa  of  the  j>lc(hyxm<i^'r»phiv  method  to  the  spleen,  carried  out 
■•  tbe  way  which  we  dM^rihcii  in  *|H-iikiug  of  the  kidney  ($  41 1)^  enablea  us 
la  study  iiiur*^  exactly  the  variations  in  voTumi-  which  the  organ  UDde^[0<a. 

A  "spleen  curve  "(Fig.  1IJ9)  taken  in  tbe  same  way  ib>  a  "  kidomr  mm** 
doat  iH>l.  in  ibe  dog  at  all  events,  show  variations  in  (be  volume  of  tW  iplaui 
(iorreB|wndiDg  with  the  pulse  waves.  Tbe  kidney  curve,  n»  we  have  iMti 
(.$411  i.irives  clear  indications  of  each  heart-beat,  but  the  spleen  curve  shown, 
the  buyer  waves  of  which  we  shall  sj*eak  directly,  only  uudulalitMia 

a» 


004 


THE    MBTAllOt.IC   PROCK9SK8  OF  TUB    BOUr. 


due  lo  tbe  reaj>irMory  movenienis ;  him]  (hew,  iilwiiyi  wry  flight,  atv 
times  not  vbible.  In  other  norcU,  th«  »|>lccii  iloo*  iml  cxiuux]  vrith  lb 
Incraaae  of  blood-prcMure  occurrinjt  in  llie  splenic  urtrries  wrttr  e«ch  Ixwt- 
Imil ;  ibis  niar  be  due  to  tlw  mueoulur  coat  rMisliD|i;  espntition.  Murravtr 
vihea  llienipplf  of  blood  to  the^>leea  ia  wholly  and  ludilciily  cut  i>d',  ■>  br 
cbiinjiinfc  tbe  aorta,  tfa«  spleen  curve  sinks  very  slowly,  ^howinu  titat  Uwi 
vplLf.n  i*  iliinioiftliiug  in  volume  not  suddenly  but  x'ery  slowly.  Tfae  pAlk- 
way  of  the  hlood  through  ilic  Hplenit:  reticulum  is  peculiar ;  ami  increase  af 
d«orMue  tn  lh«  voluniv  of  tlit-  upli-^n  means  more  or  lo*^  blood  htid  in  tbe 
aplevn  pulp,  not  nccenuinlya  rreatcror  ban  flow  of  blotxl  ihrougb  the  otj/ui, 
Of  RiM-ital  intorot  arc  (be  i*t^-  (low  viiriationa  of  volume  whitih,  beaidcf 
ibe  rMpinilatory  undiitaiinnx,  the  Kphtii  i-iirve  usually  shows,  na  aeen  ia  tiie 
figure.  Rhythmic  con  trad  ii>iu>  mid  cx[)nn)>i>>ns.  Ihou^h  not  alwayv  pnsenl. 
fmiuently  make  their  nppeannce.eacbcontraoiton  with  ibi  fellow  nspawioo 
luting  in  the  cai  and  dog  iibout  a  minute,  and  n'ciirring  nith  gmat  rrgn- 

p»>.  iw. 


mmm 


Kotuut  Sruas  tvavc  wmt»  (hw.   (Rotj 

Tlx  >i|>|i*<'  curv*  U  111*  )(<1c«n  pum  aliouliii  tliv  rliriliunc  •NinlnuUoiv  ui-l  eipaariona;  IM 
mumUh  <•■*•■  >re  doc  (o  llie  mplmMfr  nwrciiwau.  Ibi  lowrr  cam  ii  n>s  tilrml  iiiiwni  aim. 
andlh«|i«iiil«(rfi<>i"Hi<(ii  nirr*  «an«<taadi In  ilmi-  (•>  ilxiiiotiii  tufiliit  h)nod-|a<eauni  wni. 
TiM  mark*  n»  ilio  ilmr  o'lm  tola*  IihUmu  naciadt. 

Inrity  fof  a  long  time;  itnd  liiwiiU-*  thew  the  volume  variee  widely  from  liflW 
to  (inK.  Tlicre  can  be  littlo  dtubt  but  that  tbe  rhytlimic  vnrialioRs  la 
volume  are  due  in  th«ee  animals  to  rhythmic  contracti>ins,  vritli  ihtcrveniit; 
rolniatloaa.  of  the  mnscubir  trabeculte  nnil  ca^isule:  tbe  slower  viiriatiow 
are  also  probably  due  to  tbe  saiue  cnuso.  In  many  animals  th«  ooutmcciliiy 
4>f  tbe  splenic  tissue  is  riiowo  by  the  whit«  lines  of  ronstrictioti  which  nppoar 
when  tlie electrodes  of  an  induction  machine  in  action  urudrnwn  over  i(»siir- 
fii«e;  and  similar  tinea  may  be  produced  by  mechanical  iftimiilation  with  lbs 
point  of  a  needle.  Ho  tliat  the  spleen  iu  th(»e  animaU  may  be  cotundeivd  u 
»  muMular  orf^un,  uon  exoandiii)i  U>  receive  u  Inrgrr  omuitily  of  blood  and 
now  contracting  to  drive  clip  l>liio<l  on  tu  tbe  liver.  WJim  t\\v  tnii«culnr  ele- 
iiivulit  are  scanty  in  or  ulu'iit  ('mm  the  capMik-  and  trnlwctiU-.  th(^  cxjinituaD 
and  cool riK-ti oil  of  the  wlioU  nr/iiti  mu^i  dcprinl  nlntic  or  chicflv  iiu  viuia- 
lions  in  (hn  width  of  th<r  xunplyiii^  iirtcrii-*.  W'f  have  evidcnie,  nKirvover. 
that  the  inii.-wtilar  activity  "flbcuplccn.  whether  of  tlw  miis'-iitiir  capsule  and 
trnlN'ciilii-and  artcriiii  ctmibiiMol.oniflht' latter  alone,  is  under  tbe  doniinico 
of  the  nervous  syslom.  A  rapid  coiilraclion  of  the  aplocn  may  be  brought 
nliout  in  n  diniKlt  manmrr  by  Mimuliition  uf  the  »planchiiic  or  vagu*  nent*. 
or  in  a  rvdcx  nmniier  by  (.liiniilation  <if  the  ccnirnl  oud  of  n  wusory  ucrre; 
it  mar  also  be  ciiusod  by  stimiilution  of  tbe  tuediilln  oblongata  with  a  gal- 


"COSSTITI-KNTS    OF    Illl.fe:.      595 


lonraot  or  hy  im-iuunf  lufihirxin.    Thougti  thvn]»tkr  luw  unt  yut  Ikvii 

S'  worit«d  ou(,  w«  buvc  iilrVBiJv  nitlici«uitly  cloiir  lodicnliutia  thnt  tin-  tluw 
load  thruugli  Uto  spleen  i*.  tlirougli  th«  ngitnrr  af  lh«  Dcrvnu*  mvbiimii. 
_._.Nid  to  UKM  clinngin^  ii«Oi)«,  At  ono  time  a  nnM  i|iitintilv  "f  bt<jo<l  it 
pmiag  Ihnxiiib  or  in  twin^'  ticM  lir  the  orgiin,  niiil  th«  oietAUoltc  cliMigM 
wUct  il  iin<li-r|^<x«  in  llic  IrniiNt  urn  cv>m|>nr«ti«-4!ly  sliKlil.  At  niiolhvr  time 
■  brger  ouODiil}'  »{  lil<>»<l  mura  lh«  orguo,  and  ia  lot  ioow,  s-i  to  s|ic»k,  into 
t^  *f4Mitc  T>ul{i,  then?  Ut  iiiiilt.i;go  mora  profound  chani^,  and  afterward  to 
b»^K«<i)  by  lh<-  rhyltimic  eAOti«oli»n*  of  Ihe  iiiuHCular  trabeciilie. 

U  it  furtlier  obvious  th*t  these  cbongea  going  •>□  in  the  spleen  iuii%t  have 
■a  iiBponsnc  influenee  un  tiw  chnagas  going  on  in  the  liver;  it  cannot  Iw  of 
iodlApRDce  In  tbe  liltor  organ,  ivhethtr  ft  relatively  muuII  quantity  of  blood, 
fvlatively  little  diaiiged,  rtacbee  it  from  the  spl<«u.  or  whether  it  receives  a 
i«liUir«ly  lar^e  quanlity  of  blood,  profoundly  altered  b;  the  cbangea  which 
it  ha»  UMefK^Ho  >■>  tl>e  spleen  pulp. 

$477.  Thr  ehemienl  (ttntlil'itnU  of  the  spleen.     Besides  tlte  obemical  bodiet 

whid)  one  would  expect  to  find  in  a  rusoular.  muscular  or^an  full  of  blood, 

ib«  tpleeo  Gotiuiiu  bodies,  lodged  apparently  iu  the  spleen  pulp,  which  K've 

it  •fxcial  chemical  characters.    One  of  the  inaj.t  important  of  tliase  isasiiticial 

l>roiei<l  of  tbe  nature  of  alkali-albumin,  holdiu]^'  iron  in  some  way  peculiarly 

ai^wxiaMd  with  it.    The  occurrence  of  this  ferru^^iiious  ]>roteid,  ucouiujiauied 

aat   it  if  by  several  peculiar  but  at  present  little  uiiderslood  [ugmaats,  rich  iu 

carboa,  which  are  partly  present  iu  the  cells  s|>oken  of  above  and  (lartly 

dajowU-t  in  the  bfanched  cells  of  the  roticulum,  appears  to  be  coniMoted  sritJi 

tlMtfaiDgm  under^ne  by  the  hiemoglobin  which  we  sliall  {»reseut]y  discuss. 

Ttu  imrgaaio  salts  of  the  spleen,  or  at  least  those  of  it^  anh,  am  remarkable 

fnr  lbs  larK«  amount  of  both  *uda  and  pkosphaies,  and  the  »(nul]  amount  of 

polsih  and  clilnridei  which  tliey  contain,  thus  diflerine  from  those  of  blood 

ofirpuitclc*  on  |Im>  oii«  band,  tuv.1  frum  thow  of  liloiMl-sernm  on  th«  other, 

Buipcrlui|»  ihc  ntiist  Mrikingfontunsof  the  »plci*n-pulpis  ile  richnnu  in  the 

*4>^llcd  extractives-     Of  these  the  mo«C  common  and  plentiful  are  succinic, 

A>rvic.  acetic,  butyric  and  lactic  ncidfi,  inoeil,  leucin.  xuntbin.  bypoxantfain 

Knil  uric  acid.     Tyrosin  apiuirently  i«  not  preeeot  in  tbe  perfectiv  fre^b  spleen, 

^bmi|^  leucin  is ;  both  are  f  •unit  when  decompiwtion  has  set  in.     The  cou- 

•Cant  iireseooe  of  uric  acid  ia  remarkable,  espedally  since  it  has  lieeo  found 

w*B  ui  tbe  spleen  of  animals,  fiich  as  tbe  berbivoru,  whose  urine  omluius 

ooae. 

The  riehnev  of  tbe  spteeu  in  th«e  extrac-ives  id  an  iodicatiun  of  tbe  im- 
portaDif  of  the  moiabolic  events  uith  which  tbe  orgaii  has  to  do;  but  it 
will  be  nton  profitable  to  discuss  what  lilies  on  in  the  spleeu  in  connection 
*ith  tbe  metabolic  cliaujt^H  in  the  ixbcr  partji  of  the  hi^lv,  in  tbe  liver  for 
inat anca.  than  to  attempt  t<i  Iny  down  any  o'lcalled  "functions"  of  the 
■pleen.  When  wv  cmlino  our  allCDtion  to  the  oplnen  ilMilf  wu  \«&ta  very 
lo-tle;  thus  the  whole  ur^fau  may  be  Miccwtfullr  removed  without  any  very 
'^tsirioas  cliange*  in  ihv  ec»»omy  rcMulling.  We  may  rcluni,  iberalnre,  to 
lJi«  lUtcuMan  of  tJi«  formation  of  lh'<  bilirubin  of  bite,  and  of  tho  changes 
■ncltr|[r,ne  by  hnmogloliiu,  with  which  as  wc  xhnll  ft*  the  Dpiccii  is  oonneoied, 
•»«!  ahicb.  tDoraovcr,  has  to  ilo  with  the  lonnstion  of  other  pigments. 


Tbk  Formation  or  the  Coxstituh-vw  oif  Bile. 


,  S478.  liUe  pigmenlt.    Al\er  extiq«tioa  of  tbe  liver  no  accumulation  of 

*'**  ptgnietil  or  bile  mIia  mkes  place  in  the  blood.     This  is  well  aUowu  in 

s.  which  survive  tbe  ujwrutiou  for  some  coiuidenible  lime ;  but  the  same 


606 


TBBin 


PROCKSSKS  OF  THB    BODY. 


results  have  been  obtained  id  birds  (gecM  and  daoka).  Them  ma  \»  m 
doubt,  tli«refore,  ilmt  Uiese  ftubstaoonars  formed  in  ihft  liver,  bikI  BOttiia|^r 
vllbdrawn  from  the  blood  by  the  liver  in  some  such  irav  mm  wo  faATSKM 
reaaon  to  think  urea  is  withdrairn  from  (he  blotxl  by  tlw  kidney. 

Wbeo  tbe  plasDW  of  dmilotiug  bluMl  U  made  to  vouutin  limm^lohin 
detached  horn  tbe  oorpusclefl,  bile  |>if[m<-Dt  frecjueiitly  nuiki-H  itM  MpinaiMa 
in  tlie  urine.  Tbe  preaenee  of  free  hgtmnglnbin  inajp  be  obtaitimJ  by  injact 
ing  into  the  veina  a  solution  of  hwmDgluliiu  or  hloo<l  niiwle  "  Uky  "  by  fno- 
ing  and  thawing  or  by  the  addition  of  a  «niall  qunDtily  of  bile  'ralta,  or  In 
Hnijily  injrctiug  into  the  veitia  u  ituuutiiv  of  dtrtilM  wat«r  or  a  mhlU 
<iuantity  of  ether  or  chlorofonn  or  »f  bite  miIu,  all  of  which  tend  to  "  break 
u{>"red  corpuaclea  and  wet  frc<  bicmoginhin.  A  similar  mult  oocon  io 
]>oiiM>niDg  by  certain  dniifs,  Ruch  as  toluybndianiinr.  Under  theoe  einun- 
alancea  not  only  dm^  bile  pi^mi'nt.  binrubin.  make  its  nppearanoe  in  tb« 
urine,  btit  tlie  quantity  of  bilirubin  secreted  by  tbe  lirer  ia  Incruued. 
Obviouvly  (he  nreMnee  of  difaolvcd  hvmoKlebin  in  the  plnsma  of  the  blood, 
and,  prexiimnhlv  more  etpecially  of  the  olood  renchitig  iho  liver  by  the 
porisi  vein.  leaHii  to  nn  incn-iiwd  formaiiun  of  bilirubin,  which  takea'pla<« 
ID  luch  II  manner  (linl  the  wliole  of  the  bilirubin  so  formed  does  not  )ia» 
into  Ibe  bilo  but  |inr(  is  retnined  In  or  thrown  back  Into  the  circulation  and 
apneara  in  the  urine. 

We  have  already  raeniioned  tbe  cbenioaJ  connection  between  hatmoglofaio 
and  bUirubiti.  Hjemogtobln,  aftfrr  the  delachmeot  of  ite  proieid  oompootM 
beeomee  btematin  (CKl(„N,FeU,  i.  Uy  treatment  with  aulphuric  acid  tr 
otherwise  ($  352),  hnnjaiio  mny  be  d«prive<l  of  its  iron ;  and  ibia  iron-ftw 
lupntalin  (aomeliniee  called  harDiato]x>T]>hyrin)  u  laid  to  have  the  ounpcij- 
tion  (LHsN,0^.  diHering  frtim  bilirubin  only  in  ita  oxTKen  and  hvdroM 
(C„H>'.0,+aH,0— O=.CVUN,0,:i.'  Moreover,  In  old  blo<«l  cloie  In  th* 
body  tbe  hwinoglobiii  of  the  clot  bee»m«a  in  time  transformed  into  un  Inia- 
frei-  body  which  baa  been  callc<l  hwmatoidin,  liut  whleb  Uith  in  c<iii)|>ueiiii)D 
and  reactions  appear*  to  be  idenlieul  with  bilirubin. 

Thoe  tereral  raets  lead  iib  to  the  oincl  union  tbut  the  bilirubin  of  tb»  Ink 
ia  eimpty  acinie  of  the  harmoglubin  of  tbt;  blixirl  tranaformrd  l>r  the  ifaroir- 
ing  ot)'  of  lis  [iTOteid  nud  iIn  Iron  cum  in  men  tn.  Tt  i:<  nuturnl  to  auppoee  that 
the  irnn^f'irniatioii  take*  place  in.nnit  ix  iiflVclcd  by,  iheagtney  of  the  hepatic 
celb;  nnil  I  hi*  vlrw  io  vupporied  bv  the  fuel  that  the  hepatic  rvtk  are  dianv 
terized  by  rnntnining  ct^rlajn  jH-nilinr  inm  conipouml*.  When  all  the  blocd 
iii  carefully  waohed  out  of  the  liver  by  Injection  through  the  bloodveaoeK 
by  which  means  the  remuiuiiig  bite  i»  got  rid  of  at  the  same  time,  tbe  befwlie 
substance  is  found  to  cuniaiu  a  small  quantity  of  Iron,  sufficient  to  give  the 
celts  a  diffufcd  dark  color  when  treated  with  ammonium  sulphide;  lb* 
exact  amount  appears  to  vary  largely,  but  the  eausea  of  the  variation  hat* 
not  been  delciniined.  That  this  iron  is  in  organic  oombinallon  ia  indicated 
by  ihe  tact  that  «ltb  iratiiasium  ferrocyanide  and  aulphoevanide  tbe  bine  or 
red  reaction  ia  not  obeerved  until  alter  treatment  with  bydrocblorie  add. 
Apjiareutly  there  are  several  snob  coni{><iuiida,  of  a  proteid  or  nf  a  uuclcto 
(§29)  nature,  Irom  some  of  which  ihe  iron  is  more  easily  removed  than 
other*,  and  these  compounds  appear  to  be  preseni  in  both  tbe  c«dl  aubMaare 
and  (be  nucleus.  It  utill  be  remembered  (§  244)  that  bile  contains  a  dit 
linet  Quantitv  of  iron,  which  proltably  lina  its  origin  in  Ihe  iron  thus  act  frtr 
from  oirntoglobtD  and  retained  in  the  liepatie  cell;  but  il  does  not  foll>i" 
that  all  the  iron  thus  set  few  mak<v  iu  way  into  the  bile;  and,  indec*!,  the 
(juantity  of  iron  discharged  in  tlie  bile  iu  twenty-four  houra  is  much  sniallff 


■  Doubttot  tbo  (Mmuta  te  WMraUa  ginn  In  1 3av 


TOK    rORUATIOK   OF  THK  C0S9TITUKST3   OF   BILB.      697 


innc  the  »afiie  period.     Ap- 
!mv6  N<ime  iillier  work  lliaii 


I 


I 


I 


chftn  lli«  <|uaiitilj'  cnloulnle'l  to  be  set  fiea  in  the  formation  out  of  hnmo 
glolrin  i>f  th«  quantity  of  bilirubin  ilinc-bargt" 
|Mren(lT  the  iron  cumpouExiii  of  llir  hi^iiutic  ■ 
the  Miuple  (tiMhargc  nf  iron  into  the  bil«. 

Ttie  fan  ti»oulion«c)  nbove,  that  th«  pnMnoeaffrce  liamoslobm  in  the 
bloix]  Iciiila  not  only  to  nn  increatn  of  bilirubin  In  the  blU,  hiil  uIho  to  U» 
praieiKe  in  tliD  urine,  offera  aooM  dilliciilliM  ;  for  if  tliu  bilirui>in  be;  f^irineil 
out  of  hieiDOglobio  by  nn<)  in  th<^  hv]""'^  <^'''-  ""'^  vwM  cxpwi  to  fiitd  ibnt 
the  whole  of  it  passed  into  Iho  hUc.  iiad  thut  it  could  not  appuiir  in  the 
blouil  and  »o  in  the  urine  uii1«h  reahMrption  from  the  bile  powMigoa,  due  to 
ukMiinictioi),  took  place;  and  tJiero  is  no  evidence  of  any  euflicient  ob»truc- 
tion  occurring  in  thete  cnet.  Indeed  the  presence  of  bilirubin  in  the  urine 
in  them  omm  has  beeo  argod  by  some  as  an  ar>;unieol  that  bilirubin  m 
funnel!  in  the  bloid  or  at  least  ebevhere  than  in  the  liver  and  is  simply 
L-xcreted  by  the  licer.  Not  only,  however,  aa  stnCed  abnT«,  is  thore  no  Hc- 
uiimulatioo  of  itile  in  the  bioiid  al\er  exlirpatioo  of  the  liver,  but  that  oper- 
ation prevents  the  apiiearance  nf  bilirubin  in  the  urine  as  a  contteijut^noe  of 
iliu  prcecnoe  of  free  hxino^lohiH  tn  the  blo<Hl.  The  phenomena  in  ijuesiion, 
therefore,  do  noit  disprove  lliat  tlie  bilirubin  ia  furme<l  in  the  liver;  tbey 
iiiay  be  taken,  however,  to  show  that  that  funnatiou,  viewed  as  a  Decretory 
act,  U  peculiar,  since  the  hepatic  cell  appean  under  certain  cireum^tances  M 
discharf^  ils  product  of  secretion  into  the  blood  or  lymph  as  well  as  into  the 
bile  paMaire». 

M78-  We  may  awun>e  then  that  the  he^Mtic  cell  ha*  the  power  of  split- 
tin?  up  llie  li.-vmofihibtn  brought  to  it,  and  of  diiichar^iri]^;  part  »h  biliriditn 
H'bde  it  ririuinn  fir  a  linit;  the  imn  uoniponent  in  some  orjifaiiii-  riiriihiiiation  ; 
and,  if  we  fiirtlHtr  a^omt!  llial  it  work*  upon  thi*  (entire  htcmiiglobin  we  may 
premme  ihul  it  niakts  mitnc  niilMX'iiuenl  um;  of  the  proteid  cnm^Kinent.  But 
are  we  juxlificd  in  (umiming  that  the  whole  work  u  dune  bv  thr  liepntiu 
cells?  Are  we  to  cont-lude  that  hilinihin  is  maniifiichir^^Kl  by  *(ime  act  of 
ll>e  hepatic  mils  which  includeK  not  only  tlie  conversion  of  hiemot;l'ibiii  into 
bilirubin,  but  id]U>  the  extraction  «f  the  hicinoglobln  from  tli<'  red  corpus* 
clwati  ibMMt  are  Htreniuing  slowly  through  the  lobular  hepatic  cnpillarics  in 
oli)*n  contact  with  the  hepatic  ooll»?  Now,  as  far  tu  we  know  at  prownt, 
hwnioglobiti  can  only  be  set  ftve  by  lofans  of  a  disintegration  of  tlio  CJirpus- 
cien;  we  have  no  instances  of  *  corpuscle  parting  with  some  of  its  hamo- 

?;lobin  and  proceeding  on  its  way  otherwise  unchanged;  and  we  have  no 
itstolngicnl  evidence  of  any  disintegration  of  rc<l  corpuscles  in  the  liver  cor* 
reejwnding  to  the  formalioo  of  bile.  Xor  can  we  draw  any  conclusion  from 
the  result  of  a  comparative  enumeration  of  red  corpuscles  in  the  portal  and 
hepatic  blood,  for  tiiesc  are  loo  tni^ecure  to  rest  any  conclusion  upon.  On 
the  other  baud,  as  we  liave  just  seen,  the  nreeenfe  in  the  plasma  of  [he  blood 
of  h.-etnoi^'obin  in  a  free  oondilion  is  |>eculiarly  potent  in  exciling  the  forma- 
tion of  bilirubin.  The  evidence,  therefore,  \a  very  strong  f^kr  the  view  that, 
as  far  as  the  formation  of  the  greater  )>ort  at  least  of  the  bilirubin  is  oon- 
rerued,  the  action  of  tlie  hepatic  <^ell  i*  limited  to  converting  into  bilirubin 
the  fret?  h;enM>globin  oflrreil  to  it  by  the  portal  blood. 

By  wlini  means,  under  normal  coHditions,  ia  the  presence  of  that  free 
hwinoglobin  ttecured?  We  liave  seen  reiuMin  (§475)  to  omelude  from  liisto- 
logiail  apjtearaneee,  that  a  certain  number  of  red  corposelee  iinderfia  change 
in  tito  uplenn  pulp  ;  and  it  seems  natural  to  inlbr  that  one  duly  of  the  spleen 
fa  to  Mt  free  lucmoglobin  fnmi  the  corpusclcn  aud  thus,  thrduxh  the  splenio 
veilit  and  so  the  portal  vein,  to  supply  tlie  liver  with  material  for  bilirubin. 
But  ihiv  cannot  be  the  only  source,  since  the  wicnitton  of  bile  continues 
;  aftrr  CftirpatioB  of  llie  ejileen.    There  mtist,  thcroforv,  l>v  other  ivgioDS  of 


18 


TOE    METABOLIC    I'I10CBSSE9   OP   THE    BOnT. 


lli4-  liiiily  in  uliicli  h  vimtliir  i'linn([e  of  red  ctiipUKkB   is  (C"<i>R  on 
\itra  Miirgi'KU'il  (liitt  llie  red  uiimw  uf  Imiikh  is  ane  of  tbrav ;  l)ui  fur 
iiifnrniuiioD  on  l)i««e  jiointit  i*  DfMkd. 

Amupiing  that  iimirr  ixinrnl  circumMnDcrs  the  chkf  supply  of  niMm) 
ti*r  ibe  Bianiitkolurc  of  biliniliin  i't)ni<v  from  iIk-  i<{ilc«t),  ihi-  iiiirritinii  mriftt, 
Pi^-ii  llint  nitilcrinl  It'nvc  iIm*  xpli'ii)  in  iW  form  ol  Iiieini>)[M>itt,  ur  tlwsi  ibr 
«|il<-i'n  Mill  rurtlifr  a"ti<4  in  l)i<:  imitltT,  tiy  t-Ki'ciing  ioni«  fKliitiiiiHrv  duinc* 
in  Ihc  liiciDOglvbiH.  by  convrrlin^  it  I'lir  inxlnnri'  inUi  a  nrolriil  Ir*«  fuenuta- 
lilie  lui'h?  And  iheranM!  (iiiiTiion  imiv  Iw  aUi  applin^f  l"  llic  ollior  ti«u«* 
which  may  fimilnrly  piovidv  niittcria).  Our  knoulrdgc  iit  At  pn-cvnt  ifusA' 
cipDl  tu  furui^h  a  eulisfiicloty  niii>«i'r  in  mi<  )i  ii  ijumltoD. 

We  tns}r  th«n  go  to  tar  as  to  My  that  tin-  l>ilinil)iu  of  thv  liitv  t»  drriid) 
from  (be  buniugTbbin  of  lli«  blood,  and  ihal  ihc  lafr  flagvt  of  ibe  irauf 
fomiation,  incliidiD);  the  d)«cbarg«  of  the  iron  of  tbr  b:ininliii  coii>|K^irr>i. 
lake  piflre  in  and  by  menus  of  the  beraiic  rell ;  but  much  l'cy<ind  ibio  to  k 
piMcnt  iiDceriaiD.  It  oiunt  be  r^menibertd  loo  that,  though  alli-r  extirpalion 
vf  the  liver  ud  accumulnlioii  of  bilirubin  takes  place.  shoMiti);  that  llx 
bilirubin  is  formed  br  the  liver  and  not  eleewl>ere.  ytt  the  whole  (■bnu|,>r 
from  red  corpuscle  to  oilirubiD  may  occwionally  tnhc  place  quite  afiart  livia 
the  liier,  as  ^l^o»^  by  the  prewnce  of  hKiaatoidiu  in  old  blood- clots. 

$  MO.  The  j'ormalioH  oj  th«  bik-atid*.  Aboul  ihis  we  know  biIII  Ich. 
TakiD^  fclycocBolic  and  taurocho!ieacidBa»  I h«  typical  bile-acids,  recacDiib|[ 
(!i2-lti)  ihal  tlitAearire  Irom  ili«  uniun  of  cholalic  acid  with  glyciii  auirtauria 
tctpectively,  and  renM^nihcrinj;  lhal  lauriii  is  found  in  •erersl  tipMic^  and 
llial  i;lycin  (»c«  $  -l'J&  though  not  an  artual  «inBtitucnl  of  any  of  iIm'  (iNaica 
niusl  c«rlaii]|y  art»«  in  li»ue  ni^lalKilirm.  »■•  may  c^mclmle  (hal  ibc  cblef 
work  in  lhi»  n;H{iccl  of  the  ht^jwtic  cell  i«  to  iimvide  cliolatic  acid,  and  In 
rA>K(  the  conihinutiun  nilh  glyctn  and  laurin,  tlinugh  |)ci(«ibly  Miniv  ntoouut 
at  either  one  or  t)ie  other  ol  thcxc  hoilin  niny  ba  tuniinheit  by  thv  bvpntk 
aabuance  iiaclf.  Aa  to  bow  cbolalic  acid  ariwoH  out  -jf  tbemetnlxdwoi  of  the 
h<.')<aiic  cell,  no  know  im  more  than  «vc  d'l  about  tlw-  formation  of  kreaiin  la 
niutwlu  orof  pqHiin  in  a  gaftrictyll.  Wc  are  eipially  ignorant  about  tbr 
origin  of  glycin  and  tnurin,  and  cannot  explain  whir  in  i>uc  animal  glycti- 
cholic,  and  iu  another  tnurvcholic  acid  i«  prominent  lu  thi>  bill-,  Ihoueli  lb* 
iwu  bodita,  a»  abown  rspecially  br  the  prevoiice  of  sulphur  in  the  taunt),  arc 
widely  dinertnt.  It  ha«  been  ob^rvcd  that  ibe  pieeence  of  bile  i»  the  ioK*' 
line  ecenui  to  excite  llie  liver  to  incrmsed  biliary-  action  :  vince  the  bile-add* 
ore  rapidiv  changed  in  tbe  intestine  and  the  cholalio  acid  speedily  ali«r«il,tt 
f«vnu  probable  ihat  the  increoK^l  biliary  nctivilv  is  due  lo  lite  ab^irtitiuD  vt 
the  glycin  and  taiirin  rps[>ectively.  From  whii-n  we  may  conclude  tliat  llw 
pteM'uce  of  lht»e  btidies  rtita  up  tbe  hepatic  cell  to  an  incrcaw^l  fonnatioii »( 
cholalio  acid. 

fi  481.  As  a  jfenera)  rule  the  ri>rmation  of  bile-acids  rune  parallel  with  tbr 
fonDalion  of  bile  pittuent.  an  inct«i»e  or  decreaae  of  bile  m«auin);  mi  io- 
CKweordecreueof  l>o(h  ooiistiluenta.  But  there  are  some  fnctv  wbich  smm 
U)  abow  that  the  two  action*  may  t<edi<-HH-tak-(l.  The  couililion  or  MyniptiMK 
known  as  "jaundice"  ia  ewviiiinUr  an  excc^n  of  biliniliiii  in  the  blwd. 
whereby  the  lisBun  auch  »»  the  vkm,  and  \\\f  tliiidi  mich  aa  tlte  nrinit  nrr 
colored  with  tlw  yellow  pigmt-nl.  Inmuat  of  the  niahidinxif  which  jauiKiin* 
IN  a  svBiptoiu,  there  im  fvidcn<«  of  nn  i>b«lrucli(>()  t(i  tho  flow  of  bile  throuek 
tbe  bile  pataaf^ ;  an<l  the  jirtwiici^  of  bile  in  tlie  bloud,  and  bcticu  in  tW 
tiMdeii  at  lar^e,  iti  in  aueh  c»M«  due  to  the  fact  lhat  the  bilr  after  accretkiD 
by  ihi?  be|>aiw  celU  n  reahxirbwl  fnm*  the  WIe  duct*  {*vt>  §  257). 

But  in  certain  nvra  nberc  jaundice  is  a  promiiicni  xvmptom,  no  evident 
■>f  any  obstruction  whatever  to  the  llow  of  bilr  can  bi'  obtained.     Thia  in  the 


URKA    AS^»  OH   MITHOOBKOU9  MBTABOHSM. 


590 


car«  in  (lie  jauni)ic«  of  yellow  (ever  iiiul  of  a  peculiar  n1lk<l  innlady  kuowii 


I 


» 


M 


Jte  veil 


air 


I'tiv  of  111' 


iIk- 


there : 


1  evi- 


I        ^ 

■    or  I 

wk 


il«Dce  of  ail  accuiuulutiixi  in  iti«  UIumI  nr  dsonhert!  of  Itiltiaciitii  as  iWri!  ia 
of  bile  pixuieni.  And  in  the  iilM<Hir«  nialtnly  knonu  as  simpli!  ur  iiHojual liio 
jaunijire, in  nbich  thuii^li  tlu^  iiimiomiMil  coiKlilioiiii  iirc  iinkiKiwu  liicn  in  iit 
least  uo  vigil  of  iibHlrLKrlioii,  tbu  \iriiii;  iIkhi^Ii  Igwlcd  nilh  bile  pignieni  i» 
Mid  to  ronlniii  iiu  bilc'iicid". 

It  baa  itrt'ii  KU|ipiiM'<l  ilmt  llu»c  cah*  nfli>nl  proof  lh«t  the  bile  miiy  tie 
fonuetl  olMfniii-ru  lliiiii  in  ihi;  livt'r.  In  fao;  huwi-vcr,  of  tho  nrguinciita 
hr(>ii|j:)il  foruoril  in  llic  prcwiliiig  paragni^>h9',  lliry  ouinot  l>c  nccupted  M 
pnml  thul  ihi*  iiorninl  (ormiilioii  "I"  bilirubin  i»  so  oarrinl  on  ;  nor  ia  tlivre 
Uir  cvi<l<-(ii-v  lo  «hiiw  ihnt  in  tWc  nu>c»  bilirubin  is  foriucd  on  a  plim  wholly 
dilwKail  from  llu;  noiniHl,  AuH  n  tiiRcrcnt  vxplnnaibn  seninii  gKMtihlo.  Wit 
may  m\i[«<i>v  tbnt  in  ibno  cutm  the  molubolic  arlivity  of  ihc  bcjntic  ccll«  m 
TOoiJitin),  iiii>l.  further,  ao  niDdilie<l  lu  while  atfediiit^largrly  the  fornintion  of 
bile  mIIii  ami  ollwr  functions  of  the  bepatic  <-ol)s  only  pnriiatly  to  nlTc'l  the 
fonniitioti  ami  di»ch.iiy«  of  biJirubm,  to  aflect  indeed  its  dii^bari^  rathur 
than  ils  formation.  That  in  ncute  yellow  atrophy  the  ftincliuns  of  the  cells 
an-  grcutly  alfected  is  not  only  indicated  by  poM-iiiuitein  histological  appeor- 
nnces,  but  in  also  shown,  at  we  shall  itm^iilly  have  ocoasion  to  point  oiil,  by 
the  iiubstilHlion  of  leuciu  and  lynuiin  for  urea  iu  the  urine.  We  have 
already  ouiumenteil  on  lli«  faet.  that  therv  \»  something  {leeutiar  in  the  action 
of  the  hepatic  cell  iu  »«<:retin)c  bilirubin  inasmuch  ax  the  bilirubin  iu  formed 
may,  UDoer  oertaiu  circuiuMamr^,  in  iwrl  |ia^  fmni  the  cell  itadf  into  ihe 
blood  instead  of  into  thi-  bib:  piivxuv^fji.  And  no  niuy  |wrhap.t  explatii  the 
jaundice  of  tbL>  diwiiKn  umivr  dix'UMioii  by  HupiMwn^  that  the  morbid 
obaitKes  of  the  bejwlic  wHk,  while  arrmtiiiK  thn  more  diflivult  luclaliolic 
labon  of  the  ccIIm,  mich  m  (he  formation  of  nil^ucidit,  ilo  not  put  iin  end  to 
the  lih'hlpr  tiuk  of  turning  htcmoglohiu  into  bilirubin,  though  m>  aHL-vting  that 
priH^rx  iiIm)  that  ibc  bilirubin  |aiwws  into  the  bliHid  innlcad  of  into  the  bile 
paaMSRi.  In  <>lli«r  wunlit  the  formation  of  bilirubin  !■  an  act  indrncndciil  of, 
aiu)  (lilli-n'nl  from  the  more  i>rdinHrT  secretory  nclivity  of  the  cells. 

$  482.  The  question  niny  be  asked,  1»  ihu  secirlion  of  bile  independent  ol', 
or  in  "ome  way  or  other  connected  nilh  the  glycogenic  ncliviiy  of  ihe  cells? 
~^g  this  wc  cunnol  at  prt^eot  give  n  delinite  answer.     Iu  sonie  of  tbu  invcr- 

irala  ihc  cells  in  the  orftaii,  called  a  liver,  nhich  manufacture  glycogen, 
are  dietinct  from  thoao  nbicb  secrete  bile  or  other  digestive  juices;  and  it 
taight  be  inferred  that  in  the  vertebrate  the  two  actions  though  lakiug  plactt, 
OB  the  certainly  do,  in  the  same  cell,  take  place  apart  and  distinct.  There  are 
Ikcls  which  seem  to  indicate  that  tlie  two  are  iuiioiately  connected ;  but  we 
have  as  yet  uo  exact  knowledge  coucernin;;  the  matter.  It  has  been  urged 
that  the  portal  hlood  U  diivAy  coni.-erned  with  Ihe  formalioii  of  glycogen, 
and  (be  blomi  of  (he  bfr)ialic  artery  with  the  :«eretion  of  bile ;  but  there  ia 
no  sdeijuale  support  of  this  view.  It  must  he  ren»i!atbere<)  moreover  thai, 
in  addition  to  ihe  furniiilion  of  glycogen  and  the  »ei'retion  of  bile,  other 
metalxdic  events.  cf[)«:iiilly  aiR-cting  proieid  or  at  Iciua  nitrogcuvuus  ctiii- 
atitueiitE  of  tb«  body,  nro  also  taking  |ilace  :  and  to  ihcau  ne  must  now  turn. 


0»   UUKA  A!lt>  ox  KlTHOUEXOtn  UbTAW>I.I»U   in  GKXUItAI.. 


rj488.  We  have  seen  thai  nilrogenous  proteid  material  in  some  form  or 
ntberenton  into  the  conitx^ilion  of  all  Ihe  tissues  of  the  body,  and  wc  have 
l^irtlHT  n^vn  that  it  in  m>  conspicuously  and  constantly  present  wherever 
living  buImiaiicm  are  munifeetiug  vital  euei]pcs  aa  to  justify  the  concluaion 


THK    1HTABOI.T0   PROOES9R3  OF  THB  BOUT. 


tlial  ibe  cbansw  vliioh  it  uuilerf;<i>ea  are  in  iHiini;  way  encntitil  to  the  maiti- 
ftaUUion  of  lon*e  en«rKira-  ^Ve  liave  wen,  it  in  tni«.  reRMn  ti>  iliink  thai  In 
BOoie  tiasuee  >t  leaM,  in  muwie  for  inalaiicv,  ii  largr  part  iif  the  cnrrgiF'  Ml 
tne  during  ectivil)^  prei^xiMed  as  taleiit  enervy  and liait  itn  imntedititt  nunrcv 
not  in  pmteid  (nitrogenoui)  but  in  iM>in«  otJin-  (MinxUtiHiiiu  of  niiittclv;  itni) 
Indeed,  aa  vre  sliall  see  later  ixi,  the  ([ml«r  jmrt  of  tin*  wlii)k  i,iMrgT  i>f  the 
body  muM  be  iv^rded  as  lh«  eotfrny  of  mrbiui  ottinii'Minds  and  ni>l  n^ 
nltro^n  compounds;  but  Ihiii  t*  miiu<  ocuiMxtmi  with  the  vi«w  ihnt  proU-iil 
iiiiitrrial  ill  mnni-  way  or  utbi'r  a^Moiiliiillv  int<'rv(>n«»  in.  wo  mav  |HTlin{w  go 
•0  ftr  w  wi  way  dim-iM,  tho  cltan|{ca  by  wltich  in  th«  body  taergy  is  sd  tnt 
in  tb«  tteculinr  wav  which  wc  npttik  of  U  living. 

We  nave  tu^ni  tfiat  at  all  rvi-iitt  tli«  grMlt«r  mrt  of  ihp  pnHeid  material  nf 
Um)  foot)  rntvn  the  I)!(hhI  ax  protrid  nuiKrial  either  ns  peptone  »r  in  suax 
other  form,  tuid  ih  currit-d  a«  proli-id  material  to  the  ti«iie». 

Wc  linvc  mvn  that  lh<>  iiilrogi-n  of  nroteid  innlerial  IcavcB  the  body  f» 
largely  in  tlw  Corm  of  nrt-a.  that  the  other  nitrogenous  exfrelioaa  may  for 
the  time  l>r  left  i>iit  of  eons  deration. 

And  lastly  we  have  wen  reasnn  to  ttiink  that  this  urea  vrhieli  leave*  ibt 
body  in  urine  is  brought  t?  ihe  kidneys  ne  urea  iu  the  blood,  the  kMoey* 
Ihemerlves  apparently  having  no  Kiweial  power  of  forming  ureit  out  nf  wmr^ 
tiling  which  a  not  urea,  hut  only  euntributing  l»  the  geueral  slock  nf  ami 
by  virtue  of  their  own  proteid  nielaboliiini.  We  have  non'  lo  study  ihf 
little  we  know  concerning  the  steps,  by  which  the  pruteid  material  of  the  fowl 
and  of  tlie  body  is  converte<l  into  this  urea  of  the  hln«d.  which  is  the  Mmiree 
of  the  urea  of  tlie  urine. 

S  4M.  In  Ihe  first  place  we  may  lake  it  fur  granted  tliat  the  urea  carried 
to  the  kidney  in  the  blood,  bad  an  aniecedent  in  sumething  which  wna  not 
urM.  We  can  hanlly  iHipp(»e  that  the  proleid  <'oiiatilueui  of  Itvtirg  sub- 
stance, when  in  the  course  of  'i\*  nieiatKilinni  it  ceiUHW  to  be  proleii*,  bmlu 
up  at  on<%  into  urea  and  into  n«n'»itrog«tnouii  bodies.  All  we  have  leamt 
COM  lo  show  that  what  we  call  melahi>ti>im  is  not  a  singto  almi|>t  change, 
but  eonsiet  rwentially  in  a  wriiv  of  •liangiTit ;  and  we  may  safely  conclt^ 
that  proleid  malerinl  in  Wcomini^  iirnii  pnMW  lhro«igh  phases  in  nhich  the 
nitrogen  exists  in  elicinicwl  ci>mh mat  ions  distinct  frum  proteid  material  on 
the  one  haikl.  and  urea  on  the  other. 

In  the  second  place  it  is  exlren>ely  proliable  that  the  seric"  of  ehanffea  by 
which  pruteid  mnlerial  l>ecom«s  urva,  is  not  the  same  in  all  tlie  tissues  and  od 
all  Dcosions.  We  should  naturally  exjieei  to  (ind  the  proteid  material  ful- 
loving  diflerent  lines  of  inetalmlism  in  diflerent  plana  or  under  dilTerenl 
drcuDMtancee.  the  dilf^reol  lines  all  converpng  lo  the  same  body  urea,  bfr- 
cause  for  some  reasons  or  other  urea  appenrs  to  be.  iu  the  main,  the  mmrt 
GonvMiient  form  ui  which  the  nitrogen  can  leave  the  blood  and  the  bo<ly. 

Wi!  i-hould  accordingly  eipcot  to  tlud.  on  the  one  haii'l.  various  nitrogv. 
ww»  hodiis  n^ulting  fntm  proleid  metabolism  in  various  parts  of  the  Iwujr, 
and.  'in  tlx?  othtr  hand,  arraugeineaita  by  means  cif  which  these  various  bodies 
were  n-ilm-Ml  to  Ihr  niinmon  f<inn  urea,  preparatory  to  tlietr  discbarip'  firim 
the  body  l>v  the  kidney.  An  luiual  oWrvat ion  ns  far  an  it  goea  SUpjiorta 
this  view,  tli<>U|.'h  iiur  kuowtcdgi'  of  the  whole  miitti-r  ih  very  imperfect. 

§  4SS.  We  uiity  turn  our  nttenlion  firxl  to  the  m<'lali»1ism  of  tlw  skeletal 
muscle*,  siniv  tlii.r*e  n>pr«M'nt,  as  far  as  nieot  i|Uflntiiy  »■  coni-erneil.  bv  far 
the  greater  part  of  the  proh-id  capital  "f  l\w  body.  We  miiy  siilely  infer 
that  they  furiit«h  a  large  part  of  itie  un-a  of  the  urine ;  though  uiitloubteilly  n 
small  iiiiLw  of  (iwue  might  by  reason  of  its  more  ra|>id  ntetaTiolisro  xxirk  i>ver 
a  greater  c)uantily  of  proleid  material  than  a  much  larger  mass  with  ii  slower 
niutabt^isin  ;  yet  we  have  no  reason  to  think  that  the  proteid  melabulism  ttf 


ON   tTBICA    AND  OK   XITROGKSOt'A   MBTAB0LI3H.        601 


skdcml  mtiKle.  obscure  tlioii^h  ii  ■«  in  iu  oattire,  is  no  slow  at  to  neiitrnlice 
\ht  |>rohit)>l«  eir«ct  of  (lie  ^rtAl  bulk  of  mtiwlp  existing  in  the  body. 

In  (Jralinx  miih  die  eWnibitr}-  of  inti>eli>  (5  62>  we  »»w  that  nrvti,  bbtc  \n 
the  cxreiXiotiiil  insiaiic-oti  .if  (HTtiiin  nrliUginnus  fi»hM.  wm  coDtpicuoue  by 
its  nbsence  from  ibe  exlnict  of  miiHclvi.  wh«rcii*  a  rerv  appredftble  ijuaiilicjr 
of  kmttio  wail  Juvariably  prcacnt.  and,  inilecd.  n-iu  ll)c  promiueul  nitroge- 
nous cr\-atu[|iii«  <'Oti*tiUiont  of  that  pxtrapt.     It  scorns  <liliiciill  to  rraiM  the 
concluHiou  liiat  kmuin  is  the  main  normal  nitrogenous  product  of  the  inuU- 
boliiini  of  Kkvlrtal  miisclca.     If  we  accept  this  view,  then  upon  tbo  fitcl  of 
the  prexrnci?  of  krratin  in.  and  the  absence  of  tirea  from,  th«  muscle  itm-If. 
yr«  may  twsc  the  conclusion  that  while  the  muscle  pruduoee  kreatiti  ai<  iia 
nnUH'colenl  of  nren.  ihe  kreatin  so  prortooed  is  converted  into  urea  in  siime 
part  of  thr  body  other  than  the  muscle  iuelf.     Kreatin  oa  we  have  already 
wen  may  he  easily  split  up.  and  we  may  prt)hably  wilh  safely  awume  is  split 
Dp  somewhere  in  the  body,  into  ure*  and  MrcoetD.     But  samocin  does  not 
appear  in  the  urine  as  such  :  hen(^4>  the  t!onv«rsiDn  of  kreatin  into  (pari  of) 
the  urea  of  tlie  uriite  entails  an  wdl  the  further  i^mventioD  of  saretwn  into 
urea.     Now  aarcnaiD  a*  wm  have  aMn  i*  niothyl-{[lycin  ;  wn  may  reheard  it  for 
our  present  )>urprM«  as  *imp1e  clycin.  and  heniM!  ihn  total  cimcinrsion  of 
kreatin  into  nn'a  entails  the  convomion  of  ^lycin  into  urea.     Tbi*.  however, 
I    doea  not  offiir  any  adfliiional  diflinilty.  since  wo  know  from  direct  oWn-a- 
I    lion  that  slyctn  iiitnKlnoil  iiiUi  the  alini(nitary  i»nnl  does  not  reappear  as 
Lwpb  in  tAe  urin«  hut  pr>Hliio>sa  curreaponding  increase  in  the  urea  of  the 
Vinne :  fmn  which  we  infer  that  glvcin  aluorbM  fmcn  the  aUnientarv  canal 
W  ft  somi-whero  in  the  bo-ly  i-onverled  Into  uresu     We  shall  speak  of  this  con- 
f    ven>i<in  hilcr  on.  and  nhnM  then  k«  thnt.  as  far  as  urea  is  eoncenied.  glycin 
(amido-iuvtic  acid)  and  Karcwin  ( methyl*(-lycin.  niethyhamido-acelic  acid) 
underg<>  the  same  chanKe,  the  amide  moiety  in  each  case  being  oonverli'd 

(into  urea,  while  the  non-Ditrogtsnoua  moi«iy  is  oxidised  and  thrown  xlf. 
.Meanwhile  we  may  stale  the  eniMlauon  at  which  we  have  provisionally 
arrived,  namely  that  the  nilrngenons  metabulism  of  mtiw-le  probably  gives 
rise  to  kreatin.  which  in  ^ime  |>arl  of  the  body  other  than  iiiuadi-  is  proba- 
^y  split  np  into  urea,  ready  fur  excreli'w.  and  into  aarcwin  which  also, 
Hnewhere  in  (he  body,  is  fviriher  onnvertcd  intii  nrea.  Xntl  hearing  in  mind 
the  large  maw  of  the  skeletal  miiacleii.  we  may  furlhiu-  conclude  that  a  large 
portion  (if  the  ut««  leaving  the  body  by  the  urine  is  formeil  in  this  way. 

S  4M.  We  must  not,  hiincver,  leave  this  statement  wilhrnil  referring  to  A 
tlEfficnlty.  Krealinin  as  wo  have  seen  is  mt  frequently  found  in  urine  as  to 
be  reiiirded  as  n  normal  conilitutinl,  nt  all  vvenis  of  human  urine;  and 
krentinin  is  as  wc  have  eerii  the  urinary  tlirm  so  in  sjwak  of  kn-atin  ;  the  one 
body  easily  cliimgee  into  the  olh^ir  bv  the  iw>umptiou  or  removal  of  H,0. 
Tliis  eiiggesis  the  question.  Is  not  the  krenliain  of  urine  the  reprmeniative  of 
Ihe  kreatin  of  the  muscles,  wbicli  la  thns  excreted  directly  without  iindurgo* 
ing  the  ohani;e  into  L'rca  just  discuswd?  In  answer  to  (his  «-c  may  say  in 
the  first  pla<«  lh»t  the  ijoanlity  of  kreatinin  in  the  urine,  though  variable  U 
aniall ;  we  may  put  the  average  at  about  1  grm.  in  twenly-four  hours.  Now 
mttsole  conlMiiis  from  0.2  to  •)  4  per  cent,  of  kreatin  :  and  ihla.  taking  the 
total  muM-le  of  (he  body  (to  say  nothing  of  other  sources  of  kreatin  which 

»we  shall  mention  prftiwQtly)  at  about  UO  kilos,  would  give  60  to  12')  grma. 
kreatin  as  preanol  in  the  muaoles  of  tlio  body  at  any  one  moment.  We  can 
biinlly  supp'Nte  thnt  the  melattnliatn  of  muscle  b  ao  slow  m  oat  of  this  stock 
only  Ut  provide  the  1  grm.  of  krealintn  in  tweiily-fnur  hours.  Moreover, 
the  kreatin  in  urine  \-aniMhe*  during  ntarvatiou,  h  very  markedly  increased 
by  a  diet  of  tlesh  which  ronCain*  kre.itin.  and  is  not  increasuil  either  by  mus- 
cular exercise  (which,  however,  would  only  indireolly  aifect  nitr<>geoou8 


■  cuiar  ex«rc< 


003 


T  t  J  K 


OF   THE    BUDV 


mrtnbulwrn  i>f  niuKcIr)  nr  by  *tu-li  iMiicltiioiu,  ferer  fur  ioHtancp,  as  iioMI 
incrcHM  tliu  uro  of  uriiii-  by  iiicrraxii'jc  tbfi  nilmf^uouB  iuc(Al>i>li#m  of  iiHit> 
eUs.  We  infer,  thcnforr.  [|iiU  tlio  norm*)  prvseDoe  of  krratinin  in  uriM  >• 
diH  to  the  direct  nd  id  in  is  t  ration  of  krcMtiu  pnoeiit  in  a  inomiitl)  flroh  <ti«t 
■nd  has  ootliine  to  do  witii  the  miMcitbr  mvUiboliiiro  of  tii«  iudivitlual  ohu 
is  K<-reling  ibe  KrcntiDin  iu  lib  urine. 

The  fact,  iMWever,  ttiai  the  kmiliii  prcw-nt  in  tl>u  miucte  of  the  fu<<d  ao<i 
absorbed  from  (h«  atintenlary  canal  don  not  uiidcr^  a  4-biu)g«  into  urea  but 
»  excrrled  hh  krcalioin,  thul  i»,  virtuallr  ii»  kn-atin,  warnn  iii  to  Iw  vtuHul 
ID  adopting'  the  conduniiiti  arrived  at  afiovo  that  th«  knuitin  produced  bjr 
muBciilar  tti«tH  bolts  III  ill  the  livio);  body  is  a  oonapicuoue  aDt«cci|«nt  of  (he 
urea  of  llw  urine.  It  in  difficult  lo  see  why  krcaljn  pnwiiig  into  ibo  bluud 
of  the  capiilarita  of  tliv  jnutulc  shouhl  be  changed  into  unm  wnilv  that  which 
pooaeB  into  tlie  enpiltaricaof  the  portal  system  is  not;  for  rwuona  which  will 
MttpDareut  pr«Mutlr  we  Nhoula  ratlker  expect  that  the  latter  Iwing;  mure 
direcuf  expoaed  to  the  iiiflnenct  of  (h«  liver  would  he  more  r«iidily  and  nrnre 
emnpletelr  converted  than  the  former.  Iuil«^l,  the  (|ue(-tiuii  liiicv*  il^lf 
upon  iw.  Is  kr^uitin  arti-r  all  the  niitiiral  inniii  prfxluci  of  tin-  iiitrogvuwa 
metaboliMi)  of  lunnclv?  li  it  pontible  that  in  the  uorinal  mctdholtcin  of  ttir 
llvinz  muwlo  the  nitrogen  kavec  the  oiuwularwihwiuiof  and  |uu»i;e  into  the 
blooJ  In  another  form,  as  twme  BiibrtAmw  not  krcHlin,  and  that  it  is  ns  ik 
RiiiKvIo  <li«  that  krcatin  is  l>>rm«d,  juM  as  the  wltd  inyioiii  U  uuknowii  M 
living  fibre  but  makes  ita  ap|jcaratice  in  a  dying  one?  We  have  no  inwitin 
eviitoiii'e,  liow<.-vcr,  (hat  this  is  ao,  and  mranwhilo  may  (xtiitiouo  to  su|>part 
that  krciitin  is  formed,  and  that  in  conHMiucoi-e  krcatin  i*  n  i?on*piini<iui 
antirctvlcnt  of  urea  of  the  urine;  hut  we  must  not  rcgan.1  this  im  proved. 

S  487.  Our  knonledfce  of  the  nietnUiliHin  of  the  nervous  tiwuco  is,  ua  ws 
have  seen,  very  imporleot  (^  T'i).  but  the  presenL-e  of  kreatin  in  (he  ccaunl 
nervous  system  lc«ad  us  ti>  infer  l)ia(  the  nilri>t;oiii>u8  mecahulism  of  Uto  I,**i|^ 
aubeiance  of  nerve  eelU  and  of  the  axiHeylindtr  of  ikervetibrvs.  ta  i^Jm 
brotid  leaturea  )denti<al  niih  that  of  mtiM-le  autHtancc.    The  mass,  liowt-vo^ 
of  the  nerve  cellii  and  UKiK-cylindvr*  of  the  body,  uU  put  tO);«llier.  U  nnisil 
OOlDparKl  u'itli  (he  maw  of  nkektal  nium-b:  moreover,  the  ener^^  ^t  lrv<'  >>,v 
(be  metabolism  of  a  ina«»  of  nervoun  innllor  llimi^h  "  higher"  in  (|ualiiy  « 
leas  in  iiiiantity  than  ihnt  wt  free  by  ttif  nH-lnboliKm  nt  an  eijual   lUMti  ot' 
iBuacle.  or  in  <>thi'r  wnrdu  ilN  ntriaholiani  in  ]c*k  rapid.     Hi-nii;  wc  nmy  prcibi- 
l>ly  cuntiidcr  the  niclaboliiim  of  the  nervou*  sviiivm  as  a  men.'  ndditlua  to 
that  of  (ho  iniiM^ular  lyelem.  at  \vwt  as  regards  (he  })oint  on  which  we  ate 
now  dwelling.     Tkc  amount  of  nitn<getinug  mDlnboli^ni  faking  place  in  eon- 
ncetivn  lUnue,  cartilage, hone,  and  the  skin  is  probably  still  IcM,  and  lor  tiui 
present  purpMHf  nvnis  no  special  discMKSion. 

^  48B.  The  nitrogcnons  metabolism  of  the  glands,  however,  more  pwlicD- 
larly  Ihnt  of  the  liver,  does  deserve  epe«inl  consideraiion :  and  we  inny  <l 
once  turn  to  a  (juile  ditferent  aspect  of  (he  >]ue9lioii  in  hand. 

When  tbe  rate  of  ditchar)ce  of  urea  from  (be  body  is  oliscn.-eil  during  • 
period  of  some  leD);[b,  especially  under  varied  circtimntaix-es,  the  direct  eflect 
of  nitroRenouB  food  hecomea  most  striking.  W«  have  already  Miid.  and  shlill 
■nin  return  to  the  puiut.  tlmt  niiiirolnr  rontra<-tion  docit  not  directly  iitcreaM 
Ine  output  of  urea;  the  diwhaic^  of  uirn  for  inniance  i*  not  ncTwurily  in* 
ereaaed  by  even  great  Imdily  liiimr.  T)iv  iulroduition,  however,  of  even* 
n\»\\  (|uau(ity  of  pmicid  maierini  intu  tbe  nlimeiKiiry  rnnal  at  oiKe  incnaad 
(he  una  of  the  urini';  und  in  ihe  curve  nf  the  diselinrge  of  tires  in  th' 
twenty-four  houn  i-nch  lui-nl  in  followed  by  a  con»picuouB  rise.  T1»e  nbforp- 
lion  of  prctteid  uialcrial  froni  the  nlinienlnry  canal  is  followed  by  nn  inini<^ 
diate  pruportionnte  inercafc  in  tliv  i^uautity  uf  urea  which  is  ^«cmed  hy  '^~ 


nENOLS    MKTABOCl 


kidtmv.  am)  Ihnl  nf  w  hav<t  *ttn  mnuw  iin  iiiciimM!  in  tla-  iir<.ii  hmnght  to 
tbe  kiAary  hr  the  rciinl  iiri-ry.  Wbnt  »  Ihu  origin  nf  ibii-  mtilitiutiul  iirt-iit 
Two  vipwa  prrfcnt  iheiiiMlvi-n,  On  t\tt>  nav  hmiit  since  wiiui-  [MirlifjD  uf 
Ihe  (iroirii)  tnikluriat  nf  pvcrj-  nn^l.  at  hII  tvcnis  of  rvvry  iiccrtvHry  mrnl, 
B*>*»Ui  n-(>air  tlic  )>rutci<l  wmIc  (-i>ntiiiui>Ily  going  ftU  in  the  pnriBoJ'thv  bod/ 
whtn  pniK-iil  nict>lH)lif<ni  i*  lakiii);  pliicf,  ne  mmy  supjxxc  ihnt  the  pmitDCO 
■^r  an  extni  ')uaniity  of  proteid  malcrinl  tlirunn  upon  tbe  blooil  mim  ihv 
'■••wl  Bcl>  M  elimiiluH  to  iW  ti»i>i]ra,  lu  lh(>  niiiBcles  for  insliiDcv  ii«  well  ns 
'Mtirrv.  Blirf  ihem  up  to  ineTCHMH)  ititmin^iioiis  mvlaboligiii  nnil  lliiis  prodiii'es 
■1  iiif  r«aw  of  vneriiy,  i-lii«tlT  if  not  eictliifivcly  in  (he  Ihrni  of  Iicat,  atcoDi- 
p(Ui)«d  by  an  incre*iM>  of  tl)Q  antercdrnts  of  iifca  and  so  of  iires.  In  otlicr 
Worda  tbe  increaee  of  urea  in  quratioo  is  tbo  result  of  an  iDcrease  in  lh« 
Btrfleral  nitro>;raoua  metabolism  of  the  body. 

On  th«  other  band  we  niav  suppcee  that  in  order  to  prevent  ibe  whole 
l>o«Iy  lieiDjc  eDcumbered  "iid  il,  this  exrew  of  proieid  fimd  maierinl  ia,  in 
•OOie  special  |)art  of  the  bndy.  aplit  up  into  a  nitrogenous  and  a  ni>n-nilrci- 
|t«rDcius  ntuiety,  and  that,  while  ih«  latter  ia  stored  up  ue  fat  »r  KlreoKen.  the 
r«>rnier  m  at  imce  coo\'ett»d  into  nr«a  and  ([oi  rid  if.  We  liave  already 
<  $  ^4U>  »een  ibat  a  step  in  iliis  dinciioD  may  take  place  while  the  fund  U  as 
A-rt  in  tbe  alimcuiari'  <.-anal:  we  have  secu  ihni  punrreiuic  jiiii-e  may  rarry 
pan  of  the  pmteidri  nu  which  it  aits  beyond  tbe  MAjte  of  alhtinioae  and  |)^p- 
Xontt,  and  rtduco  that  part  into  Ifuein,  tyroMn.and  mlivr  lii)di««-  We  do  not 
know.  n«  ne  have  idn-ady  Mid.  In  what  extent  thin  more  iirufound  dijiieitioii 
btv  iMincivatii.'  jnirr  ilocx  nctually  tiilcf  plnn-  in  tlie  living  Ixidy  ;  it  may  take 
f  >1ni*v  I')  a  vrry  kH^-IiI  cxlrnl  and  it  may  under  <'<'rliiiu  (ircuini'tuui:*^  take 
|>lai:v  to  a  eoDHidi-nililc  extent.  But  in  anv  onir  it  ilkiiitratm  the  wnv  in 
^■htcli  n  Krmewhnl  ziimilnr  dieruplioii  of  priiteid  material,  a  disruption  wliicli 
niav  l>e  hmadly  di-M'nlK-d  as  a  splitting  titt  of  the  proleiil  into  a  nitrugeitoiis 
mtna  a  non-nitroct-nouii  moi«ty,  may  lake  place  somcwhen  in  the  body  and  wO 
ttad  U>  ibe  sudocQ  furmntiou  uf  tome  antecedent  of  urea.  The  auteccdcnt 
SDkT  be  leuciii  or  may  be  some  other  body  or  bodies. 

In  support  of  this  view  may  be  urged  the  fuel  that  such  bodies  as  leunn, 

xtycin,  B(paraj:in.  nod  many  oiliers  when  introduced  into  the  alimeolary 

•««iial  are  transformed  into  urea.     When  these  bodies  are  adniinistered  in 

Dut  loo  K^v*'  quantities  they  du  not  reap[>esr  in  tbe  urine,  but  the  urea  b 

proportionately  incieased, 

i  468.  We  liave  >eeii  rernum  l»  think  tlml  tbe  proieidi  uf  u  meal  are 
■btnrbed  nut  by  the  lacteah  but  by  the  portal  bloodveswh,  and  such  bodies 
Si  Ivurin  probably  take  tbe  same  eourse.  Tbii*  heinK  yu,  all  thtue  bodies  nan 
thfuufth  the  liver  aiitl  are  subjecte<l  to  sticU  iutlueuof^  a»  may  be  exertea  by 
ll»  hepatic  rellit.  Nxw.  we  have  nu  |iusiiive  evidence  that  the  liver  does  or 
OUi  exetl  such  an  urtiuu  on  jirolud  mBlerial  itself  as  lu  wparate  u  relalively 
nnple  nilrcigra  cuniiHiuiid  from  the  reiuniuin;;  cunNtiluenlN,  leaving  these  to 
ibrni  a  body  rich  in  earhon  ;  we  have  no  jHicilive  proof  that  the  increate  of 
Jtmi^id  melalioltMn  just  >{»>keo  of  as  leading  to  an  increnw  of  uren  tiikco 

Clar«  in  the  liver  rather  than  in  (he  liM>uti>  at  large ;  trc  may  go  ao  far  per- 
■  ps  a«  to  Minpeel  that  it  i*  largely  »r  wholly  confined  lo  tlie  liver,  but  we 
fa«va  no  convincing  demon >it rat i'>n.  We  have,  htiwever.  a  convergcnm  nf 
•vidcnca  that  the  Inol  otagi'  of  iIhi  proers^,  nainelr,  Ibe  oonvereivn  into  urva 
*>f  SMRinor  other  pniduci  of  prolcid  metabolism,  nfiich  though  allied  to  is  not 
^XBrtljr  urea  ilom  oeeiir  in  the  liver.  In  tbe  tint  place,  a  larg«  ouanlity 
*^f  urra  (retn*  to  lie  pnMwnt  in  the  liver  of  mammals:  in  this  resticct  ttie  liver 
f^rv*«iits  II  strong  eonlnut  ti>  the  mufcleo;  in  the  liver  of  birds  tbe  urea  la 
*■  wpre»enied  by  urates.  Moreover,  nhen  a  stream  of  freeb  blixiid  is  pMnd 
everal  Itraes  lhroii;;h  the  liver  of  an  animal  recently  killed,  the  pereeHlage 


604 


THE    METABOLIC    PUOCKftSKS   UF   THE    BOUT. 


of  urea  ill  the  blood  sn  need  is  found  to  be  d«ciiiledlr  inerenaed.  Thi«,h«i- 
ever,  does  nut  prove  timi  iiruu  in  formeil  in  the  fiver,  si  nee  tiie  tacnwd 
(quantity  of  urea  in  the  lilimt  wliicli  bad  been  eirctilHled  raixbt  bavc  bna 
simply  urea  wlitub  liiu)  lieeti  wa^beil  out  fWtin  tbe  liver,  wbvre  it  hwlfir- 
vimily  been  mayiiij;.  Still  iia  far  ob  it  goes  il  in  suggeMtve.  In  tbewoitid 
place,  in  cerliiiii  ciiwm  of  a  furmof  diaeaae  vf  tbe  lirer  known  tu  arule  iyIU* 
iitiY>[iU}'  in  u'bioli  tla-  hi^imtic  o^li  are  *o  cliitii|i;e<l  tliat  tbeif  fiiar!i<ru»l 
iiclivily  In  lur^roly  ilim!ui»Ded,  Uic  urea  of  the  urine  uot  oiily  undi-r^gnn  t 
very  inttrkt^l  dwnate  but  an(«ani  to  bu  mplaced  to  a  very  \mrgp  •Mwil  bi 
ii;iii-m.  Tin*  fiiet  Huegeata  thnt  Ivucin  (iind  not  for  inalAOoe  krMtls)  wtlii' 
chief  imnii'jiintc  prixlurl  of  the  nitrogiMirouK  mctnbolism  of  tlit  bodT,  mi 
thnl  tbo  Ivuciu  thtit  priHlucc<l  i«  in  u  normal  rI«c«  of  ifain^n  ranvcRM  iau> 
uru«  by  the  livor.  And  in  ihi«  conuuclion  it  may  be  rcioarkwl  Ihit  M 
only  it  Ivucin  found  In  ntuirly  nil  iho  liwue*  ufkcr  duilb,  especially  in  tb« 

tiandular  (tMut«.  bnt  nho  ap|Knn>  wilh  striking  reodinma  in  alnualill 
cieompoeiliona  of  prok-ids,  ami  i»  moreover  a  product  uf  deeoiDpmitioa  oT 
Eptatinifcrous  subntnim-e,  Without  going,  bowevof,  to  far  as  to  ooDclaJe 
Uiat  loudn  is  the  chief  tintoccdimt  of  uren,  wo  mny  tjik«  the  nbovt  obaatfr 
tioD  as  indicating  Ihnt  the  normal  liver  has.  la  tome  way  or  other. the  ptnr 
of  converting  leiicin  Into  iircii.  If  this  be  so  we  mny  aim  vejiture  to  lUfpM 
Ihnl  when  inch  bwlie?  as  Icucin,  glycin,  etc..  inlividuced  ioto  the  alioieiUarf 
cnnal  apiienr  in  the  urine  nt  iirca  the  transfuroiatioa  bax  taken  place  inlbf 
liver.  Ihe  body  tyrosin  which  «o  often  accompantu  leuciu,  belotigiof;  y  il 
doea  to  the  nrouinlic  series,  stands  on  a  diHerent  footing  from  leuciu  andlbt 
lik«. 

§  490.  The  CmnAformntiun,  however,  of  louciu  into  urea  nuses  a  new  jn'ml 
of  view.     Lcnrin.  us  ne  know,  it  aniiilo-caproic  acid;  and.  with  our  pfwrni 
obeinieal  knowledj^,  we  can  cjjueeive  of  no  other  way  iu  which  Uucin  no 
he  converted  inlu  urea  than  by  the  comjilel^  n.-duction  of  tbe  former  la  lb 
ammitnin  condition  ('[be  ciiprolc  acid  rivldue  being  either  olaburat4d  inttt 
fat  or  oxidixfd  into  cnrbi)ntc  ncid)  and  by  a  re  eonn  I  ruction  of  the  laltei  noi 
of  til u  aniRKiiiiu  »ii  f'lrmiHl.     We  have  n  ><>nii! what  jMmllel  com  iu  gljua, 
which  is  amiiiii-mielic  add;  here.  tin*,  a  revon*  I  ruction  of  urea  out  i>f  « 
amnionin  phnxe  must  lake  place.     Moreover,  when  aromoniuni  chloriik  ii 
^ivcn  to  II  dog  n  vary  liirite  (xirtion  mi|>pciirs  lu  ur«a,  i.  r.,  there  is  an 
increase  in  tbe  urtaof  ih«  urine  corrntponding  to  n  largo  porlioa  of  lbs 
nitrogen  conlsiincd  in  tin-  iimni'iniiim  chloride,     .\ud  in  ihe  case  of  oilier 
nnimals  al»i>,  inih-cd  iif  niiin  hiiiiM'lf,  there  is  evidence  that  soinoirbere  in  the 
body  ammonia  mny  br  cmverii'il  into  urea.     Henco  in  all  thoM  casee  where 
ammoain  or  ammonia  {-uttiponmU  niv  chnnf.'cil  into  urea,  tbe  last  st«n  at  all 
events  is  one  of  synthcsi*  :  and  thi*  suggt^t*  the  jioHibility  that  in  Ute  ordi- 
iiarr  proleid    niciubiilisin  nlsn,  the  itownwiird    katabolic  series  of  clianM 
may  linisb  off  with  a  Miilliclic  t-D<irt.  the  last  ttaj:^  of  the  foruer  being  Ibe 
appearance  of  iiu  iiminonia  ciitnpinind  which  is  eubaequenlly  reconalnJCIed 
into  urea. 

'lliis  synthesis,  like  the  trans  form  ution  of  leucin  and  other  bMliaa,  proba- 
bly tjikce  place  in  the  liver:  and  in  support  of  this  view  we  hare  a  certain 
amount  of  experimental  evidence.  Birds  may  be  kept  alive  aAer  total  exlir- 
|Mliou  of  tbe  liver  for  a  longer  time  than  can  mainniiilB;  and  wlivn  in  geeae 
tbe  liver  is  removed  the  uric  acid  (rrprv^enting  in  thew  animaU  tlie  urea  of 
the  luauininl)  is  lar;;ely  deoreosed.  while  the  ammonia  of  the  urine  ia  lar^lv 
iucraaseit.  Aller  the  removal  of  the  liver  also,  leucin,  glycin,  and  otber 
amide*  or  amido-aeids  administerod  t»y  ihc  alimentary  can>l  no  longer 
tncreaie  the  uric  acid  of  the  urine,  as  they  do  in  the  intact  animal.  In  tbeae 
■nimak,  tbe  synthesis  of  ammonia  eonip»un<I*  inin  nric  acid,  nbich  la  parallel 


IMP   ON    NITBOOENOUS   HETABObl 


» 


\ 


I 


to  th*  ayntbcna  into  urea  occurritiK  in  the  mammaT,  ««etii«  to  take  place  in 
tW  liret,  and  we  may  inter  is  to  »>ini«  way  or  other  elTeoted  by  the  liL')nitic' 
oelk. 

As  to  tke  exact  way  in  vrhich  ammouia,  either  as  such  or  in  form  of  aD 
taode  or  aiiitdo-aci<)  chaiiKra  into  urea,  we  have  no  certain  knowledge. 
AnnoDiuni  cartiuuate.  we  kuow.  is  readily  lomied  out  of  urea  bv  ulmiilc 
hTdratioo,  and  we  may  iumciiir  that  ilitr  living-  organiain  ghd  carry  uiit  the 
merae  ptttcvm  mad  dehvitrati^  amiiiuniiim  cnrlKMiute  into  urea.  There  in, 
iMWerer.  a  ceriaiu  aniuuni  nf  i!vi<li!nce  that  o<>t  aniinr>nium  ojirtHmute  but 
Hinoniuiu  carbaxuale  iit  the  iuin]i.'<)iale  aiileci.ilvnt  (il'urui;  lun),  indeed,  nut 
oTthe  body,  by  elect rolr tint:  a  Nolution  of  nnimnniiim  carbaninli-  with  alt«T- 
Uliug  current*,  a  certnni  aoioiint  of  urea  may  W  arliGcially  protluocd.  But 
lliu  ia  a  maitrr  tiui  iib«<^ure  to  Ixi  diiM'u»<«l  Uvtv. 

$  481.  {'n>  aeii!.    Tlii*.  like  urea,  is  a  uurmnl  conRtitncnl  of  human  nrinc, 
•ad,  like  art*,  ha*  Iwen  f'xind  in  the  bliHxl,  in  the  liver,  and  ia  thv  vplecn  ; 
it  b  a  ooiupicuouK  voui^litiicnt  of  an  exinict  of  l4ie  latter  nrgnii.     In  tomm 
anuDala,  hucK  as  Itird*  and  inn*!  rvpliles,  it  take*  (he  place  of  urea.    Tn  vari> 
ous  diaaaaw  the  uuanlity  in  the  urine  is  incrtiM.il ;  nod  nl  tiineit,  u  in  gout, 
nrie  acid  ■ccumulatc*  in  the  blood,  and  n  deposit  of  unitos  lakc^  place  in  the 
tiMUM.    Sine*  by  oxidation  a  niolocule  of  uric  acid  can  be  iplit  up  into  two 
moleculntof  urva.  luid  a  moleculflof  M>tn«  carbon  acid,  uric  acid  is  commonly 
■ookra  (if  ai  a  liiw  oxidiHnl  product  of  proteid  nictalxilisin  than  urea.     But 
UMir  ia  no  eridenoc  whatever  to  «how  thai  the  former  ii  a  necesmry  ani«- 
«idMl  oT  Um)  latter :  ou  the  contrary,  all  th«  &ots  known  go  to  show  tliat 
•^  Bpfwarance  of  uric  ncid  is  the  result  of  a  m«tabo!ism  slightly  diver^ng 
from  tJint  leading  to  urea ;  indeed,  it  ia  |>robnb]o  that  the  divergence  occura 
toward  the  end  of  the  scries  n{  changes,  tor  urea  given  by  the  mouth  to  birds 
mppean  in  the  urine  as  uric  aeid,  and.  conversely,  uric  add  given  to  mam- 
■Bwa  appears  in  the  urine  as  urea.     W'c  have  no  evidence  to  prove  that  the 
«suae  of  the  diver^ooe  lice  in  an  insutticienl  supply  of  oxygen  to  the  organ- 
iun  at  large ;  on  the  contrary,  uric  accid  oceura  in  tlie  rapidly  breathing 
Urd«  a*  well  a^  in  the  more  torpid  rcplllcd.     Nor  can  the  fact  that  in  th« 
fnc,  again,  urea  replaces  uric  aci<l  be  explained  by  reference  to  that  animal 
bsTing  M  large  a  cutaneous  in  addition  to  its  pulmonary  rtapiration.     The 
fina]  cauMS  of  the  divergence  are  to  bi*  wnight  nither  in  the  fact  that  una 
h  the  form  a'lapird  to  a  Hind,  and  uric  ncid  to  a  more  mlid  cxcrenK^ut.    Nor 
■I  ifatn  in  man  or  ihv  mammal  anv  aaiiHfni-tory  [>hy»iologtc«l  or  clinical  cvi- 
dnet  thai  en  incrcoiH'  of  uric  ncid  i.-<  ihii  romlt  of  deficient  oxidation.     The 
abaolulc  amount  of  uric  acid  diiw^barged  by  man  and  ila  pri>|>ortion  to  the 
uiM  [laswd  at  the  Mine  time  varivs  a  gootl  ileal.     There  is  no  pomtive  cvi- 
dnice  that  the  (jtianliiy  cxcreled  is  neoesiaril^  iucrcwHHl   by  nitrogvnoas 
diet.  ualeM  some  dixirder  supeivracs;  indeed,  it  in  nsecried  that  botn  abw^ 
htaly  and  relatively  to  the  urea  the  (quantity  excreted  is  greater  upon  a 
Bitzed  diet  than  upi*n  a  heighly  proteid  one.     Alknlica  in  the  food  sn'ni  un- 
doubtedly to  diminish  it.  ami  alcohol,  at  leant  in  excen,  to  incranse  it. 

Su  far  from  eonsiileriog  uric  acid  «a  a  lem  oxidized  nntocetlenl  of  urea  we 
ought  |ierha[ia  rather  to  regard  its  appearance  as  a  result  of  a  synthesis  in 
%hich  urea  or  some  allied  body  takes  part.  As  we  have  nid,  uric  acid  may 
b«  fiimitd  BTtlthctically  by  heating  together  urea  and  glycui ;  and  it  has 
tborv  reveutJy  been  similarly  prepared  from  variuus  allied  bodies.  As  to 
where  or  bow  «ich  a  synthesis  is  eifected  in  the  living  body,  we  know  littl« 
oc  mrthlng  for  certain,  and  ean  only  make  conjectures.  The  constant  pres- 
•««  of  uric  ni-id  in  ihe  spleen,  however,  and  the  frequently  noted  connection 
btlwern  a  rite  and  fall  of  uric  add  in  the  urine  and  Tariatioue  in  the  volume 
and  therefore  preaunuibly  in  the  activity  of  the  spleen,  euj^geet  that  the 


WW 


Tin 


*AnoLIC    I'ROCRaSKS 


chttDjn  niiiT  1m)  t>nMif!;lit  iihnut  in  thiit  »Tgmii ;  tmt  it  intut  ht  nmttiubuti 
llillt  in  birds  and  r«titilc«  the  rormmioii  nf  uric  lU'ti)  mcrir  Io  Iw  BtKeCnl  In 
tlie  BameorniwMlnat  of  urpii  kikI  in  nil  iiiin]i>g;i>ii*  nianiiftr;  mail  lUu  nrgv- 
aveata  which  «"«  h»ve  u«ei)  concrniing  the  fnrnmtitin  of  iin>n  in  the  liver  ot 
roammalB,  niar  Iw  njtpliod  U>  Ihr  furRintioti  i>f  uric  xoid  in  Ihe  liv«-rs  of  liinb 
and  re]>tilra.  It  a  more  |initMbk-,  therelurv,  thtit  in  thu  toninnml  ijie  turn 
to  uric  acid  mther  thitn  um  is  givm  in  tli«  liver,  liM  apken,  however,  pa*- 
aihiy  playing  il«  part  nlen  In  the  mnltor. 

$'49S.  Of  the  meaning  of  th«  nppcarnDoe  in  llw  liseuee  of  siicli  iKHlka  w 
xnuUiin,  hyjKixiimhin.  gtianin,  nnd  the  like,  and  of  tho  esact  nature  uf  tht 
laelabolism  which  gives  rise  to  them  or  whieh  tlwy  thenmlvee  uD<)er)io,  we 
know  little  or  nothing.  The  preNOce  of  ihc^e  several  bodim  inny  1m  taken 
a*  illuNlraiiDjr  the  eomplex  ana  varied  nature  of  proteid  nie4nl>oliaiii  to  wliich 
we  n-ferred  aoove-  Urea  is  the  chief  eDd-priKluct  of  proleid  nKtaholinin.  hul 
thitt  4-nd  in  probably  reached  in  aeve**]  ways;  ao  thai  probably  a  very  Jtir^ 
tiiiiul>r-r  iif  nitroK^noia  chemical  substances  make  a  monieninrv  np{K>aruee 
in  tl»<-  IxhIv.  Some  of  theee  fail  to  become  urea,  and  either  wIiVhii  nr  aflar 
fiirdier  ehange  make  their  appearance  in  the  urine.  But  we  do  not  )(ai>w 
nhelher  tlivir  appearance  »  aecidentat,  Ihe  nwult  of  iraperfbct  cbcBUcal 
mnehinery;  or  whether  they,  llwugh  HrnaH  in  laianltty,  tterve  miuo  apodal 
ends  in  t^c  economy.  I'eriiapa  sometlmei^  or  with  mhuh  at  tJieui  it  \»  tltb  out 
eaae,  at  oih^^r  dmea  or  with  othcn  il  i.'t  the  other  caae. 

When  proteid  material  undergoes  outside  the  iMxty,  either  by  tlto  actio 
of  trypsin  or  a»  the  iv»ult  of  dAcomponition  or  under  tlti!  inflHenoeof  ehcuictl 
ai^entB.  that  chan^  bv  which  it  i*  converted  into  leuciii,  the  leiioin  which 
appears  in  s<ime  coniiidenible  (juantilies,  it  nccoiDiMtuied  by  tynMn,  whitk 
appenra  in  (mailer  (piBnlilii,«  a*  well  lu*  by  other  iKxIin.  TIm!  aloiiMt  coDstaal 
appenranoe  of  tyrosin  ax  ii  rceuU  uf  the  decompocition  of  protmd  material 
leaids  one,  as  we  have  previously  siud,  to  the  conception  that  >orm  rvpnaeula- 
live  of  the  aromatic  scries  enters  into  the  constitution  of  piutaid  subMaiiM; 
aud  it  is  pomible  that  the  hippuric  acid  of  flesh-eating  animals  derives  ib 
beniioio  ncid  constituent  from  thisaromaiie  radicle  of  prui«id  matter,  TymMD 
itwlf  does  not  appear  in  the  body  as  a  normal  product  of  protcid  nielaboliscn, 
and  we  are  therefore  led  to  inJer  that  in  proieid  inetiiboltsm  the  aruroslic 
riuticle  takee  on  some  other  form.  WhotJier,  as  in  lymnn,  the  amiaatie 
(phenyl)  nucleus  is  associated  with  an  ammonia  repreeeolative  or  no,  we  do 
not  know.  Bui  if  it  is  then,  since  neither  lyrosin  nor  any  similar  Imdy  iti 
mnftituent  of  normal  unite,  the  ammonia  constituent  is  some  when;  iIIhmo- 
ointed  fnmi  the  phenvl  one;  aud  while  the  former  t-onlributes  to  the  Jt-wk 
of  urwi,  the  latter  is  either  disctmrtieil  by  the  urine  n»  hippuric  acid,  having 
iiK  we  have  neen  eHeoied  in  the  kidiiev  n  new  a«>ociation  with  Ibe  nmmoiiis 
n-prtsenintive  glycio.  or  leaves  the  Wly  as  one  or  other  of  the  uriuary 
phenyl  mmpnunds,  or  |>oMihly  rihv  txf  u>:idix«d  ountewhere  into  cnrbonW 
acid  iind  water.  Our  knowii^jj^'e  on  thin  fH>int  b  limited,  hut  ire  have  ven- 
tur^il  to  n-fer  to  llut  point  *iuce  it  further  illustratM  the  complexity  of  pro- 
teiit  niHabolinm. 

§  493.  In  Kpcakiiin;  uf  urea  {i  402)  we  allnded  lo  ila  retaiiuni  to  iW 
oysnogen  con)|Miuii(tH.  Bmrln^  in  mim)  the  fieouliarly  large  nm<'i. 
energy  net  free  iii>  lieni  during  the  isomeric  trnn<'formaiion  of  many  r>  :■ 
compounds,  as  well  iwlhr  liirge  store 'if  [Kilmtiiil  <-iK'i¥y  existing  in  iv«iAi^>ai 
itself.  i!ie  heat  «!'  comhiisli'in  uf  which  is  Vfry  laiye.  and  cnlnuitiiig  ihiM 
properties  with  th'i^  "I*  uniiiiuniu  and  tltr  iininionia  eonipounds.  we  cani»al 
nelp  Wing  tcmptod  toward  Ihe  view  (hut  in  the  nctnni  living  •tructure  the 
nitrogen  exii-ts  in  the  form  of  cyanogen  compounds,  nod  lltitt  in  the  {Kfeage 
to  dead  nilrogenuus  waste,  during  which  energy  ia  Mt  free,  Ihe  cy 


STHUCTCKKS   ASD  rROOBSSKB  OT  OnSOlTBB  KATl*BB. 


I 


> 


ooiupotiitil  cbangn  to  tlie  amide  or  other  nmnuMiui  T«prtM«Utive.  And 
thoiv  iirv  UTcml  I'aviH  whkh  Ini'!  Bupporc  lo  such  a  vi«w,  auch  its  llie  prw- 
«noe  of  »iilp1ii>cy«»ira  iu  naiivii  and  urine,  wbicli  we  niiiy  look  upon  lu  n 
wort  <if  lenkngc  ofarunogm  I'lU-ton,  lh«  artifioinl  proHiiciioii  of  Icreatinin  out 
of  pynniulc  iitiii  Miri-ixtin,  mnd  oth«r  facts.  But  (lie  iiiattor,  ihuii|;b  h  deMri-eg 
lo  hi-  l>»riM>  i»  ntiDd,  iit  um  obacur«  lo  be  dweJt  on  liere. 

§  494.  \Vc  may  unv  1iri(-lly  »uni  up  (be  varit^  <lieciiMi<>iia  whivl)  have 
occupied  us  iu  tln'  iimiciit  tMvtion. 

Urea  i*  tbc  nmiii  wid-prmluci  of  pniWtid  iDMaboliitni.  I'liliico  hippuric 
arid  aud  soiDe  otlier  conelitiiitnlBi  iif  urin«,  iirva  in  niuply  i-xcrvldd  bv  the 
kidneys,  bang  brought  to  tbrin  in  llir  blo(id,  thi^y  apfxiri'iitly.  beyond  the 
tiinple  ai-l  ol  excretion,  doing  no  more  thnu  nicrfly  cnntHbucJD^  [<>  the 
stock  of  uren  iu  bo  far  as  ihcy  iiru  ruimm  of  ])ri>li.-id  material  uiidergotiij; 
proteid  metabolisni  as  part  of  ilieir  svnirral  life.  What  are  tbe  in)m^iat« 
iinteoedenU  of  una  we  do  not  dearly  know;  t»it  it  is  probable  that  they 
are  not  one  but  several  and  indeed  p^raibly  ninny.  We  have  reason  to 
lliink  that  urea  may  be  furmc<l  out  of  amid(«  or  amidii-acidt>,  or  out  of 
ammonia  itself  by  a  synthetic  nrooc^s;  and  we  liave  indieatiuoa  that  this 
synlbe&is  iieflected  in  tbe  liver  oy  ibti  agency  of  the  hepatic  celU.  But  we 
do  not  know  whether  this  avuthesia  bear«  only  on  particular  r it ro^n- holding 
Mibnanoa  of  food  or  of  tW  body,  or  whether  it  comee  into  play  in  the 
uomial  inetabultsm  of  proteid  material.  If  ibe  krealin  whirb  in  to  coo- 
apicuoufl  a  riiiuiituent  of  muacular  and  uervoua  structural  ts  a  Mtjigc  iu  tbe 
air«ct  linu  to  iiri-a,  then  the  synthenia  would  aflfacl  only  tli<!  wmvHtni  which 
tJ»e  krttttin  in  becoming  urea  wets  free.  But  we  have  sneii  tliat  it  is  by  no 
means  clear  that  krentiu  iw  M«h  a  atage. 

Tbe  evidence  as  far  as  it  goes  tendii  to  whnw  that  the  inriabi>li8Tn  of  proteid 

is  very  complex  and  varied,  that  a  lar^  number  of  nitrngon. holding  auk- 

Ktanoi*  make  a  momaitary  apiK-aruDcc  tn  thn  IhhIv.  taking  origin  at  this  or 

that  step  in  the  do«ii<vanl  Hliur>  <>f  katabolic  m<^lid>oliiim  and  changing  into 

aonM-thing  el»o  at  the  next  atcjt,  and  that  lliu  prv*«-nci-  in  various  jMirta  of  tlie 

liody  and  even  in  the  urine,  in  small  'juaiiliiitv,  »t'  ki>  many  varied  iiitrogenoaa 

eryiitallini-  i>uli*taiiGcs,  fonuiog  a  lari.'c  part  of  what  arc  known  as  e-itraclivee, 

has  to  do  with  ihie  varied   metnbolinm.     IVmtlhly  the  tranatbrniaiions  by 

which  nitro^'en  thus  panes  downward  take  place  to  a  certain  extent  in  sucn 

-    organs  as  the  liver  and  the  spioctii,  which  are  remarkably  rich  in  theae  ex- 

I    tractives.     But  the  whole  slory  uf  pnvleid  melabolisni  eondsls  at  prevent 

^^MBlly  of  guraaes  and  of  gaps. 

I      J* 


Os  SoatE  STKt'trriiKBs  axo  I'kocbssgs  ov  0B4ct;H8  NATirRi:. 


S  48}.  ne  Iht/roid  b<nly.  Certain  structures  of  obwrure  nature,  but  |>rut>- 
nbly  connected  in  auiue  way  or  other  witli  some  of  ihe  metabolic  procCMtes 
ill  tlie  IxNly.  ana  oHen  spoken  of  inider  the  unduairahle  name  of  "ductlcM 
glands."  .Sich  are  the  thyroid  body  or  gland,  the  |>ituitary  l>ody,  tlie 
ibyuiiia,  and  the  xuprarcual  caiisulea.  These  dillcr  from  each  other  »>  msen- 
tially  that  ibe  only  plea  which  can  bo  urged  in  favor  of  oiin«idcrtn^'  them 
lujrother  i.i  convciiiitnce  and  our  ignorance  of  ihf  ir  nupcrtivc  functions. 
IT- Xbi<  ihvh^d  IkuIv  is  tite  one  of  the  group  nMwt  deserving  to  )<c  ciillct  a 
ad,  siui'v  ii,  like  tltc  lung»,  ariwea  asatwodobed  diverticulum  fn-m  the 
ventral  *urtikcc  of  the  antctior  ^Kirt  of  the  alimentary  canal,  and  at  Arst, 
like  the  lungs  atf  ■,  huhnv<s  as  if  it  were  about  to  iMCximc  a  double  racemose 
gland.  The  tviniM^ciion  with  the  thnnit,  however,  which  should  have  become 
a  dud,  U  mxin  olillleralcd,  and  tlie  two  lobn,  united  with  cacJi  otlwr  by  au 


HDS  THK    METAHOLtO    rSOCESSRS   OF   THE    ttODY. 

iNhmii*  ncroffi  tli«  tniclKii.  Umv  nil  tnocs  of  nny  lirnnchini;  duets  witKin 
thtlD.  nnii  brormio  tranKlttrmo)  into  niBM«  of  iBol«t«d  ituctlew  alv«(ili  bcui&d 
tofMlii't  K'itli  r»tiiiccti\T  tiiHie. 

HtiRci-,  vrhiii  It  MMkhii  w  lnk«n  through  a  hardened  and  prppareal  lol»a( 
Ml  niliilt  thvrtiwl,  whikt  ta  «e«it  is  n  liinitiDg  cnpaule  of  oi)im«ctive  tlMur 
eendiiig  into  th«  interior  numorouB  septa,  which  Hirruund  and  fte|>nrBt«  frnn 
euch  other  round  or  ovnl  sjuces,  the  sections  of  the  ieolaiwl  aIv*Mi|i.  [PiC- 
170.]  ThcM  are  of  variable  siie.  some  being  visible  to  the  nakul  eye,  aiM 
each  is  lined  br  a  sin^'^  layer  of  low  columnar  or  cubii-al  nucleatnl  vHk 
reating  on  a  btsement  niembraiie.  leavinj:  a  lat^  cavity,  which  lo  (Vtih 
•pedmena  is  filled  wiUi  a  glairy  fluid.  The  ix\\»  present  uo  apcciKl  diw 
ftotem. 

ini>.im. 


I '      ^I'^.rT,'^^. 


BiuTuo  or  nia  TiiTMtb  Guini  or  a  Cmut, 

Two  n>iD|ilMa  ndcloi  aQi]  poillulit  al  cihcn  ■!«  rvi-iwcnled.  Tlw  Tiii<rlll  Ma  Mlljn(||h  •-•UcM. 
1>hl(?bBl*narra|ilwih*liitvnlllfNl>|fln»,  In  1t«  uMdM  o(  am  of  tlw  (pMNRMMSTCSat  Wierii 
put  obll-|Ui>lf ,  ind  ciiM  lo  II  !••  rlatiM  tvIL  IMse*n  (tieiublcal  ((itkHlllD  C«n«mall»r«>nill>* 
lymph  ruriiiuclr*  nn  htrt  anil  Ibm  ■«n.| 

The  Mpla  of  eanitcctiv«  litaue,  fairly  rich  in  elastic  «1cnicni«,  but  reinark- 
■blj  Irm  from  Mili|»iMT  tiMue.  cuiitain  numerous  bloodvesnU  <(criv«d  from 
the  wperior  and  inferior  thyroid  arteries,  the  braiinhn*  of  which.  relatir«ly 
lafve  and  rni-ninilly  Hmwidmiwinp.  end  for  the  mont  part  in  mpillary  Det- 
woras  round  tlio  alvculi :  from  Lhe«e  i-apillari4«  and  lAuwi  of  tJte  eeuM  ibr 
blood  is  gnth«rcd  into  veinn  iilifi  rrlaiivtily  largi',  which,  forRitDz  pleXDaw 
on  the  surface  of  the  oretn,  vnd  in  ihi-  itu|><-rii>r  middle  and  in»nor  thy- 
roid veins.  The  thyroid  tKiiiv  \*  tbiiv  ftirnixhni  witli  im  abundant  anpply 
of  bkod. 

Tbe  sepia  nbo  eontain  a  rer^-  larve  number  of  lymphatic  vessels,  whicli. 
botli  on  the  surfacn  of  (be  organ  and  along  the  mpia.  arc  arranged  in  |des- 
nB«e  of  anaslotnoeing  trunko  of  ii>R»ickTubTe  ai».  .Small  uodulea  i>f  adeDi^d 
tiMae  are  al<o  found  iu  the  sepliL 

The  nerves  of  the  thyroid  body  are  also  abundant.  They  are,  in  man, 
derived  cbieBy  from  the  cvrvical  sympathetic  nerve,  paasin;;  olf  from  tlie 
middle  and  lower  cervical  ganglia;  their  exact  terminations  within  tbc  xrgan 
b  not  known.  Fine  GIatnent;i  are  also  said  tu  be  given  ofl*  to  it  from  the 
external  branch  of  (be  ntperior  laryngeal  nerve. 

The  "acceisAry"  thyroid  bodies  ollen  found  are  of  theMiae  nature  a«  tbe 
main  bo<)y. 

Very  IVeiiuenlly,  to  freijuentty  in  the  adult  m  1a  b«  of  almoM  normal 
ooeurreace,  the  alveoli  contain  not  simple  glairy  lluld  but  u  more  aolid  clonr 


STBCCTDBK9  AW    PB0CK8SXS  OF  OBSOl'BR   NATUBB. 


I 


I 
I 


malt-riiil.  cnllixl  "rolloid  :"  tbiii  gviivrnll^  «[>|)(^iin>  in  tliQcciitrft  ofiin  nlvvnliis 
Mwl  laity  Hll  up  the  wliolt!  Itinuin  ;  iKTu!nnnlly  morr  i>r  Imw  chnugcti  e\i\- 
(hrliftl  itrtlK  in»y  111'  wM-ii  lying  bvtvrmrn  it  nml  the  lityer  ol*  ovIIk  ratting  on 
th«  tMwmiMil  mcmbraDC  £xtrxvaMilu>iu  of  blmid  into  tbo  nlrooli  nra  nImd 
■  not  ijni»niin<in. 

Tbv  tbyriHtl  body  m  ren*  opt  to  bceomfl  enlarged,  MmnimfK  enoTmouMy 
>o,  and  is  ihvn  *pok«it  of  m  goitre.  The  mlAreem^nt  may  be  iltip  »ini{ily  to 
nn  incKuae  in  thv  number  t>t  otlicnriH  fiiiny  oormnl  alveoli  aikI  mpta. 
But  very  often  n  number  of  a)v«oli  bccomo  more  or  lem  conltuent,  forming 
«  cyst:  itnil  at  times  the  whole  inland  ap|>eiiT«  to  be  compueed  of  n  aiimber 
of  cysts  of  vArying  size,  frc(|ueally  lofidwl  witb  "onlloid"  materinl.  There 
ifl  also  n  form  of  goitre  id  whioh  the  enlartjeiuent  is  chiellv  or  even  exclu- 
sively due  (o  an  increase  in  the  vascular  BUi>]>ly,  the  bloodvMeels  being 
abnormally  distended :  and  this  apparently  may  occur  without  auy  structunu 
(^hangee  in  the  walh?  of  the  blooaveeaele.  Somelimes.  however,  the  arteries 
aoder^  Mwuriatnal  enlnrgemenla,  with  ohangce  in  tbdr  comu. 

The  gluiriDMB  of  the  fluid  coDt«nia  of  the  alveoli  has  genentlly  been 
attributed  to  the  presence  of  mucin,  and  thia  body  has  sAti^  been  said  to 
kas'e  b««o  found  within  the  lymphatic  vessels  rtinning  in  the  itepta;  but 
some  obeerven  have  urgeil  that  the  material  in  ■(ueMion  ia  not  true  mucin, 
but  a  peculiar  form  (or  fonn)>)  of  [iroteid  *ub«itanc«.  The  "  ooUoitl "  mat«rial 
eo  frequently  apix«ri»g  bus  uIho  \it«a  ruganled  as  allied  tu  mticiu,  but  \i» 
exact  nature  ban  not  as  yet  b«cn  KutkliKclorily  determined.  R<Mdai  tbcM 
•pecial  nabMauon  the  alveoli  or  cysla  uIho  contain  »enim- album  in  nud 
etobiilin.  Tbe  "extractives"  nf  thi;  thyroid  amiear  to  omiaiu  knMtin  or 
lireatinin  In  not  inc«i»id<^rnblc  i]Uitntilici«,  XAiituiu,  and  lactic  (paraloctJc) 
icid :  gtiauin  is  snid  to  Ik  abMcnt.  In  htrgv  and  old  cyM«  ebolertotiD  is 
•omciinM  pratent ;  and  wlwn,  us  ol\cn  ha{i[>nD8.  cxtrnTaantioaa  of  blood  into 
tlw  cn4ii  luivi^  litkcti  place,  hatmoglobiii,  or  nt  n  later  stage  liwmatoidia 
(bilirubin)  has  ti««n  fotiRiL 

S  486.  The  larga  mippJy  of  blood  to  tbo  thyroid  suggMlii  the  id«a  thiit  the 
ornii  is  the  leal  of  sonu  of  tlic  siilwidinry  mctjilMlic  procema  to  which  we 
retcrrvd  iu  the  laat  aection,  and  thin  view  in  supported  by  the  presence  of  the 
cxtruGtives  just  mentioned;  but  we  hnvc  no  detailed  Icnowledgo  of  what 
actually  goes  on. 

The  pnneace  of  the  peculiar  mucin-like  body  in  the  alveoli,  and  the  teu- 
dencr  to  "  colloid  formation,"  further  suggest  some  relation  of  the  organ  to 
the  lormatioti  or  distribution  of  mucin ;  and  this  view  has  derivMl  a  c«rtua 
Hipport  from  some  ezperimenuil  results,  hut  theeo,  though  numerous,  have 
proved  neither  uniform  nor  accordant.  When  in  c«rtuiii  animals  (mookeya, 
dogs,  and  other  caniivora,  and  the  same  baa  been  observed  in  man)  the  glaud 
is  extir|>ated,  even  witb  the  greatest  care,  the  operation  is  frequently  folTowetl 
hy  the  oci-iirrence  of  pe<-uliar  nervous  sympton».such  oa  muaoular  twitchinga 
nod  tremors,  siMunia,  and  even  tetanic  convulsions  (more  especially  obaervM 
in  young  animaJs),  aecompanied  or  succenled  by  irregularity  or  failure  of 
voluntary  movemeiita;  mbaequently  there  may  ensue  varied  symptoms 
which  niiiy  Ik^  dnrrihed  under  the  general  term  of  disordered  nulritition, 
ending  evuntunlly  in  death.  In  a  certain  number  of  cases,  however,  in  the 
above  kinds  of  uniniul,  no  HcrinUH  Hympioms  follow,  even  the  total  extir|>ati<>n 
of  tbfl  organ  iirixliiciog  no  marked  dlect ;  and  in  rah  bits  and  other  herb- 
ivArous  niiimaU  removal  is  raid  uttrer  to  t>e  followed  by  any  of  the  abovo 
re«ult«.  It  has  been  urgcil  ihiit  the  symptonia  when  seen  are  the  efibcts  not 
of  I  he  mere  absence  of  tito  organ,  but  of  mischief  set  up  by  the  ogwrattoii  In 
ndjoitiine  «tructuros  n>or«  nj>ecially  in  the  laryngeal  nerves  and  vagus 
trunks ;  uut  this  do«a  not  sceni  a  valid  explanation.     If,  aa  suggested  abovo, 

an 


610 


TOI 


tltuLlC    PROCKSSES 


BODY. 


ogiMJn  BWtNlHlio  proccwM  nro  itornuilljr  going  on  w  t  liv  <irgan,  ims  msy  dirlf 
■UpptM  tlial.  is  tbe  BbMuw  I'f  the  orgnn,  th<^  iiik'rTii|>tiou  of  the  DoriMl 
■equMtoe  i)t  cbtmicHl  chnncv  woniil  tlirow  ii|m>ii  iW  cirmltttion  wruk 
itnuigi)  «ub«MfMWBwbirli,KCling  lik<-  n  p<>i»i>ii.  might  pnHlucr  the  iiar  voua  synip- 
tome,  Ihrow  Jnlo  <)i»ort]fr  thi.^  oiiiriCii<ti  of  vnt'unit  Iimum,  u)c)  finalk  ttriug 
alwiii  ileiitli.  W«  mar  farther  ex|>)uio  the  cHt«  whorv  STinploiaa  are  aheeot 
1>y  Bu|>po«iQg  thill,  for  Mine  rciieoD  or  other,  "  thiii^  have  lakea  a  diflbnut 
luni,"  the  pnrticular  |HjignnuuH  sulwlancca  have  Dot  [uad«  their  apiiearttDit, 
but  iunocuous  ohm  havo  talcm  their  place;  aad  we  know  hovr  dli|-lii  * 
ehw^  in  chemical  coinixmtion  maf  turn  a  poison  into  an  inert  bixlj--  'Hiti, 
of  eourse,  remains  a  mere  euppooUon  until  -m  can  eisie  what  tho  ^xtM 
inetBboliv  proceascs  are.  sind  Dsme  tbe  substancee  vbich  work  ihn  miM-hi«f; 
but  il  seema  more  reii»>»able  l«  accept  such  a  proviaiona)  BU|i|iuMitii>0,  tliaa 
U)  conclude  tliat  the  thyi\.iit  may  be  removeil  uithiiut  )inii]u<-tMg  aajr  aSott 
whatever  i>u  the  urKiuiiHm.  An  atiimal  without  ii  ih.vr»iil  may  npfxnr  pe^ 
feotJy  «r«II,  because  the  eircunutanoee  to  which  it  l:<  (tx|iiw<l  <}o  itot  ha|i(Mi 
to  teat  the  ini[»erfection  from  which  it  ia  realty  !<ullei*iiitc,  ju«t  as  a  roaB'i 
inability  to  itnim  may  not  be  apparent  until  lie  hap|K-nii  to  Ail)  into  Um 
water.  '  Tlie  MEiimaU  which  do  succumb  to  the  nperatiuD  of  rem^iral  »f  tb* 
organ  nr^,  for  WMne  reason  or  other,  put  to  thi!  tiH,  anil  ar«  found  wanting. 
The  very  dlflcordaiiGfi  of  the  experimental  niiult*  )i»intH  tl>o  physiological 
mural  toal  the  pheuomcnii  iiiiich  wt-  uiv  an  yt  able  tooliwrve  flirot,  Mit 
vcrc,  a  mere  :<iirf»ce  c<ivcriug  iiitricute  j>rucc«»cs  at  prevent  wbolly,  or  Dtail; 
wholly,  hitUli-n  from  un. 

The  above  vxpvrinK-ninl  rcHulu  receive  additi'iml  interral  and  at  the  eatoa 
time  support  from  clinical  experience  Tbe  co»n<.*clittn  between  satire  aad 
cretinism — ibe  latter  clincaw!  Iieinfi:,  broadly  spetikiug,  a  rvsiilt  of  iiaorderMi 
nutrition  (clling  iarKrlr  on  ihu  iicrvitu*  nystcm— line  long  l>eeu  rec>i)fTii]U)<l ; 
and  attention  has  auo  DC«n  called  to  eocav  tic  between  dlwatse  of  the  tliynid 
ami  a  morbid  condition,  known  as  myxtedcmn,  in  n  certain  number  uf  caaa 
of  whicb  mucin  or  a  mucin-like  bodr  boa  been  luund  in  Kreat  exc««  in  tbe 
akin  and  in  other  tissues.  In  manKey*  the  removal  of  the  thyroid  low,  ia 
•ome  cases.  l>eea  followed,  besidee  the  symptoms  mentioned  above,  sumr  uf 
whidi  rtttemble  those  of  rayxoedema,  by  an  accumulation  of  mucin  ura 
nmcinlike  bmiy  in  the  skin  and  various  tissues.  Il  is  very  dilHcult  not  to 
connect  thi^  with  tbe  fi^rmnlion  in  the  thyroid  id* colloid  nvatiTinl  in  the  mn- 
Wntf  of  Ihe  iilviWi.  Hut  we  know  so  little  a&oul  tlie  nature  of  mucin  awl 
its  altiiii,  abi)ui  Ibeir  real  relations  to  more  ordinary  prateid  nulMtanoea,  nnil 
obout  the  giart  tihich  they  play  in  pbysio logical  ]>roceMea.  that  any  views  «i 
to  tho  exact  connection  belu  een  the  nreeenoe  of  mucin  in  the  tt«»iie^  at  laq^ 
and  cbai^ca  taking  place  in  tbe  tnyraid  muH(  be  at  present  to  a  lur^ 
ext«nl  iq9eculnlion. 

Thv  large  vascular  supply  of  tlic  lhvroi<l,  and  tliv  |>lM-nomvna  of  a  dbeaae 
known  IW  eiophtlialmiv  goitrv,  in  whie^i  vascular  culargumMit  of  the  thyruid 
is  ansociatol  with  cardiac  syraplom«  and  other  vascular  disturbanoea, eaped- 
lilly  of  the  bead,  have  oiigKefled  that,  njiarl  from  mutnbolic  pninmiii.  tbe 
circulaliou  in  the  thyroid  nmy,  nerhajn  in  a  more  or  Um  mechanical  way,  bt 
c(>nnF<-ied  with  niid  inl]uen<«  the  circultttioD  in  the  brain.  But  tbe  exMi 
nature  of  thix  inllui-nce  bus   not  bcc-ii  made  clear. 

S  497.  Tftr  jiituilani  lioJy.  Tlie  lower.  |KMt«rior,  lobe  of  this  orj:an  r«M<ia- 
biw  the  tliyroid  bixly  <  ibo  upper,  anterior,  lobe  ts  of  qnile  distinct  UMUn, 
beinK  really  a  part  oi'  tlw  rciilml  nervous  system),  in  as  much  am  it  1*  n 
diveiit<-ulum  of  the  nlimenlary  eiiiial  (nnnieiy,  of  the  mouth),  which,  instead 
uf  lM!cumini>  n  branclicd  inland,  is  converted  into  a  uiaae  of  round,  or  oraltCr 
cylindrical  alveoli,  Htpaiated  by  septa  of  vascular  oonneclive  liaaua,  Tliougli 


STnUCTt;RES   A*rD   PR0CER8EH  OF  OVSCPBE  KATCRI!.      $11 

In  wme  iiirtBiicw  tin-  ulvwii  ol'  the  pituitary  body,  like  lliose  of  the  thyroid, 

pOHMM  H  liinif'n.  which,  n>areov«r,  mnv  hnid  more  or  km  "  collnid  "  cont«aU, 

the  ninjnrity  nrc  solid  iiiMeeR  uf  epitlieliiil   celU.     The  cells,  which  are 

cnluiniior  or  polylM^ral,  pr»ent  no  epecial  characlers,  expepi.  perha|>«,  ilml 

bvtv((«n  tlwt  iiHinl  cpithi^lisl  cells  are  occaBiunally  Touud  spindle  !<haped  celb, 

itppurcntly  of  nicsohliuik  origin. 

C»nccrniii)>;  (be  jirooeases  which  uke  i>liu-e  in  thwe  alveoli,  aud  tlt«  pur- 
poses of  ihe  organ  at  a  trhol«,  we  know  abwiulely  nothing. 

S  498.    The  ruiimrrual  boditt.     A  (»mmiii«lian)  Niiprvnfflnl  body,  wheu 

ctit  iKn»8,  is  seen  to  c»n»iiil  of  Ino  dutinct  partK,  an  otitcr  thicker  mrft'oi/ 

part,  of  yellowish  (v>l»r.  Htriated  radially, 

and   an  iuuer  ihiniH-r  mrtluUarg  {tart  of  t        ^ 

darker  color.    [V'tji  171.]     Attlie<kprM- 

Mon  ou  tlie  anterior  .turfacc  <-«ll«(l  the  hilun, 

whence    isMie-    th<!    coinjiaratively    large 

Fiipra-re«fll  vein,  lh«  curtvx  thin*  away  »i 

thai   the   ntcdiilla  mmm    li>   tho   (iirlunr. 

ThcM  iKo  partH,  cortex  and  ini.'<lullu.  arc 

not,   like   tlie   cortex    an<l    itiixlulla   of  a 

Ivnipbatic  gland,  dttrrrenl  arraniii-mf-nlB  of 

the  fame  inatrnal,  hut  arc  of  <v>M-nlially 

diflcn-tit  iiuturc,  and,  ind*'»il.  areofiliHi;rftHt 

origin.     Tlic  medulln  if  derivvxi  fmni,  in  % 

mod  ill  cat  ion  of.  «ynipatli<^iip  g^iigliii.  while 

ihc  orlex  is  de.rivr<I  from  niamw  of  mew- 

lilamic  (tIIn  iturn>»niliit)i:  the  Krnit  blowl- 

vOtteb;  and  in  ifunii:  animals  the  Ino  form 
^  wholly  ec|iunit>-  bodice,  The  si>-i;nMed 
■■jaeiMory  supnt-reiink  am  ronipoMMl  of 
^^^rtcx  aloiin. 

Thfl  wholt  W]gan   it  surrounded  by  a 

ai|Mdo   of   connective    tissue,    free    from 

muscular   libres,  and    not  very   rich   in 

daMte  elements.     From  the  capsule  eeptn 

pass  inward  and   ftrm  n  frameworb,  the 

caviliee  of  which   are  filled    by  cells  or 

(•roups  of  cells  dilterinc  in  nature  and  dif- 
ferently arrangni  in  the  cortex  and  in  the 

inedulU.     The  middle  larger  juirt  of  the 

cortex  is  composed  of  eomewhiil  long  solid 

oolunuiB  of  polyhedral  cells,  lodged  iu  cor- 

retpondinjK  iDesho  of  the  framework.  The 

columns,    whieb  arc    three   or    four   cells 

thick  and  several  im^Us  in  length,  though 

•utDewbiit  irregular  and  varying  in  sixe,  do 

not   anastomose.   Wiuj;   irhitUv  m-piirated 

frotD  each  other  by  the  Wn  uf  i-oiitio-tive 

Umne,  and   jhimcsh   no  central    cavity  or 

laiiMn.     Tho  liloodvoHeU,  which  an.-  ubundant  in  tlieie  bars  of  connective 

tunic,  do  not  [lenetratc  tlir  riitumii^.     The  i:ell  !<!ilK>iance  of  the  cells  is  of  a 

yellowish  color,  ol\cn  nmiaining  vrllowixh  oil  gloliulet,  and  podseKU  a  clear 

round  nucMio. 

In  the  oater  jiarl  of  the  cortex  inimc«lialGly  underneath  the  capsule  il  a 

thin  xone  in  wl)ii:h  tlie  gron^w  of  cvil«  are  not  columnar,  but  niuudcil  and 

irrvgular :  and  ngiiiu  in  the  inner  part  uf  the  cortex  abutting  on  the  modolla 


I 


VEsnc-ALtliicriaMMSi'i-r.i'iKoii.  Bonv. 
(XU)inincil  I 

I.  uvtimi  tilManc* :  !.  miNlulliur  i**^ 
•ud»:  a.  ttiBtnit :  i.  tail*  ilunuiraliMi : 
r,  kin*  CuiitcuUU:  <l.  »>na  rotlculiirUl 
I.  ■raaiaof  innlullvr  orlli  i /.  wMioii  «( 
« latp  tdu). 


612 


THE    MUTAIIOLIC    ftlOCESSKd    or   Tlti:    hout. 


fs  Hiiolhcr  thiit  uinr,  in  whicb  (bi?  columnar  arranj^iuenc  is  ]>.  I!« 

being  hvn  ttitpoeeil  in  a  necwork  of  thio  cor<l»,  and  tbe  it><ltviilii.< 
Inrgv  «xteiit  Mpttrated  tnm  eadt  utiier  by  delicMt«  citniiuuutiuiu  ut  ih<- 
Goaner  connecUre'ttmte  MpU.  ilvm^.  the  ntaiu  mediau  [mri  ut'  tli«  iom.  \ 
which  frutu  tbe  ]>roiuineiit  culuiiniar  arraofcenient  kppears  atriuttsl  m  < 
is  oflcn  caIImI  tbe  »>ua  fascioulala,  the  thio  outer  part  the  xona  {{luioviui  - 
uiiil  tbe  thin  inner  p«irt  the  xuoa  reticularis:  hut  a»  fkr  «•  Um vRwniial 
diaractera  of  the  cells  are  ooncem«<i,  all  tbe  iliree  touea  are  alike. 

Tbe  medulla  also  oonaiUs  of  eells  or  fjrouus  of  oelU  lying  in  ihv  innihni  uf 
a  connective-ltwue  nvmework,  but  the  c-ens  are  of  a  diflereiit  iinLura  fnin 
thoee  uf  the  cortex.  Tbcy  are  irr«frular  and  often  bnuit:h«d,  and  their  ivll 
aubalauce.  Ihousb  it  »i>Ri«tinie«  <<un(aii>a  )»|froetil,  t*  fctinemlly  rtcnr  awl 
tnnaiMireinl.  Tbe  iDedulla.  ninreover.  ix  furtbi*r  diMtinguixbticl  fmni  the 
Ctiriex  bv  lh«  ubuwinnt  Mi)i|ily  »f  hl<iodv««wla  and  of  tw:rvM. 

The  cgIU  uf  tbe  medulla  and  of  tbe  iuuer  wn«  (Una  rrtkularis)  of  Ike 
cortex  lire  very  aj'l  Ut  untleiYu  cbanue  after  ilcatli.  anti  to  boocMB*  diffiuMtt. 

TIm-  artrrini  winch  eoni^  mmi  Oii^  mirta  and  friiin  tbe  nati  and  phnaie 
artertisi  jiuni  inti>  ihr  organ  on  tb<^  Mirfacr,  «n<l  travcrfinp  ihit  ourtox, stipgrfr- 
Ing  an  llu-y  go  both  (!H|niilt'  ami  mrt^x  with  a  niudi'nile  iiiiiulfer  of  vematt 
end  in  the  imxliilla,  ibc  (1)nn^(rIiv<^li.■«tIe  luire  of  which  Ixuir  uuniorous  Uup 
Y4DOI1K  MniiK-i>.  into  which  (be  cn[>Illariu'  jxiur  their  hliMxl,  and  fra«i  wMek 
tbo  bUxx)  is  gnihcrtMl  up  iiiiu  Uie  »uprn-T«wl  vein. 

A  targe  nuiiilHT  of  ni-rvut,  M>nsi»ti»);  chicAy  of  tnediillated  libtva  fnnu  the 
Bolar  )>lvxuH,  thi?  renal  i>lexii».  llie  j^renic  i)urv«,  and  the  Taf{ii»,  iwmi  iiiio 
the  ■u{>m-r?iuil  body  at  the  liilno  tutd  od  the  under  surface,  a»d  foruiins 
iiunicTouv  i>trxu«(«.  coarae  aw)  (inc.  some  carrying  tunall  groups  of  nerve 
cells,  end  chiefly  io  the  in«lult.i,  though  eome  pnaa  on  to  tM  ooitex.  Tbe 
ullimatc  endi»g«  are  not  yet  knowo. 

The  lympliatimare  fairly  numerous,  and  form  plexiiece  in  l]w  capsule  and 
in  the  connective  timue  of  the  framenvrk ;  it  is  staled  that  the  lymphatic 
veeeeU  surrounding  the  groupsof  oella  in  the  cortex  commuoinile  wrilh  spaoca 
between  tbe  celts. 

^490.  Ueaidce  the  onliiiary  proleid  and  other  chemical  ooostitueiils.  the 
snnra-reaal  body  cuulaina  sume  subsianoe  or  eubstaDcea  posseasin);  atrikiag 
color  reaoUous, ;;ivinf;  a  dark-blue  or  darkgreeo  color  with  ferric  olilori(l<^ 
and  a  cannine-reil  tint  wi[h  variiHia  oxtdiunK  atrenta.  Tliis  Bubstanco  f  whoa* 
nature  is  not  exactly  kuouu,  and  which  is  confined  to  or  most  nhundani  in 
the  tuedulta)  is  not  aoluble  in  the  ordinary  aolveuis  of  pi)ctiM-iii»,  MUch  ai 
alcohol,  etber,  ehlorofonn,  etc.,  hut  is  readily  soluble  in  dilute  acacb. 

Anionx  the  extractives,  hippuric  aw)  beiiioio  acid,  and  laurodinlJc 
or  taurin  have  been  found,  out  it  ia  not  certaiu  lluit  tbaie  are  ooroutl 
stiluents. 

i  600.  Hotiie  of  the  bitlolojctcul  featumof  the  Hupra-renal  bodii.>«. nanal^, 
the  rniujiv  of  <fll!i  aiid  their  abuudani  bhHKl-:>u]>ply,  NUggeM,  on  tl»  u 
hand,  that  imimrliuit  metabolic  prooeNteit  taki-  place  in  them,  »ouo  of  wbl 
are  prulxahly  connected  with  the  history  ot^ tbe  pipmentv  of  tlio  body  at  lat]. 
On  ibe  other  band,  the  unusually  larev  norvv-«upply,  and  tlio  durivalioti  i 
part  of  the  bixly  from  tbe  HyiiijiathKic  ganglia,  iiuggmtit  pciiiliur  nervo< 
cuiiiiectioui>.  And  tlte  organ  has  often  acrvcd  iii>  a  i>(iirtiug-|K>int  for  specu- 
IntiiiiiN  in  ilii»e  tw<i  direction* ;  but  our  exact  knowliilgi.'  i>intx-riiing  tlieni  is 
very  liniiu^j.  The  nwulli>  of  cxiierimeni  have  taught  ut  lilllr;  cxtirjNUiou. 
for  cxBiuple,  has  been  otleii  followed  by  the  doatli  of  the  animal  operated 
ufHiu,  but  the  cause  of  tbe  dvvth  ia  such  c«Ma  b  br  no  mtwuf  ciMtr. 

Oiw  fact,  glinftd  by  clinical  cxperieuc«,  n  tlie  only  real  ilvin  of  knoMledgu 
which  we  poneat.     I^iseate  <tf  the  supra-reual  hwlio*,  H|>|)«reritly  lulicreular 


CESSES   OF   OBSCl'RE   NA 


:iti^  W)cii)niiit!  in  l)ic  in«liinn.  is  »n  oflrn  Rsmctiilccl  with  n  o)ianK« 

:  III'  nil))  iin  incrvDiv  "f  ihv  iiii;iw(il  nf  tlic  »\dn,  "  lin>nxv<l  vltin," 
II ■■.!._. -_ J  .:.  I... _  .1...  ._... 


Id  I 
in 

**  -\  'Iwi'iLM-,"  ilvnl  ■Atni^  cotiiui'tKiii  Ix-twif'n  tin*  iwo  iiiiikI  oxwt :  bni 

tli<  .  ^itiku  of  ihr  cliain  nrc  ■>>  yet  iinkti'iun.     Il  t*  trfiiitfin;;  to  iittm- 

ci»tt>  Uiu  incn-AK  of  pi^'tn^Dt  in  Ihr  l>r»«z<xl  wkin  with  the  i-ltruniof^ii  or 
cotor-jHtfliliDi;  wiMatitv  xpokra  of  ahov*  ;  l>ut  ve  linvc  no  wnrmnl  lor  'iimig 
•O,  Hii-li  for  inMiiniv  iif  miT  indiwtioij  iif  lira  boiwi>oii  tlm  >ii|)r»-rt'iiti]  Imliea 
mM*l  <-h«>iig(«  'iihnr  in  hvmoglobin  il^df  or  In  bilirubin,  which  tiro  bmllM 
^•w  l\»vt  niuon  to  rt^n)  more  pnrlicitUrly  ae  molWw  of  pi;,'m<.'m.  More- 
'OVcr  thv  brt>Dic<l  #kin  is  oiilr  oti«  of  ihr  sTi»i>lomB  of  AitiliBoii's  ilUeuc, 
fiulitrv  of  tiiitrili'Ki  and  Derroiis  •^'mptoiiii'  being  dso  present. 

§  fiOl    T%e  Ififfmut.  Tliis,  thniigli  il  ai-iM'#  in  ihc  embryo  as  a  paired  cnt- 

f^iwth  (Vom  tite  epithelial  walls  of  a  pair  of  viseeiml  clefb*.  and  thiiH  begiits 

a«0  Dii  e|>ttbetial  structure  into  irhioU  meeoblastic  elcmeiif»  subseiiiieQtly  in- 

Cruile,  soon  )Mit«  on  such  cbaracters  aa  to  appear  eswulially  a  Ivinphatic 

Mtrueture,  am),  in(l(«d.  mi^ht  be  regarded  as  &  ])art  of  the  lyiiiphatic  syTUni. 

It  DDDsiMs  of  a  capMile  of  connective  tissue,  plain  muscular  tibns  being 

■tlnrai.  u)d  aepta  or  tni>)eculie  of  the  rame  nature  which  divide  the  orpin 

Ibio  ■  number  of  irreunlur  inure  or  leea  orliDdrical  aiiastoiuosiuK  follicles  or 

lobulw,  and  H'lid  finer  nidialiii^  septa  inui  the  interior  of  each  lobule. 

TImm  li>buliv  preiL-iti  iIk-  Niiut.-  characters  ihrouxhout  the  whole  lusai  of  the 

«TrgMD,  there  noi  U-iug,  an  in  a  lymphatic  j^anil,  any  dixiinciion  tietween  a 

cones  ami  a  miilulla  of  tbe  wliolc-  body.    The  words  are,  however,  applied  to 

«Mb  lobule,  to  i]i;>liii;:iii»ti  Uie  central  from  the  )ieri|>lK'ral  {larl  of  ih«  lobule 

Itaalf.     Both  the  ii>-ntrat  ineilulUi  aiid  tbe  pcrijihcnd  cortex  of  tiach  lobule 

Oootitt  of  a  frnmcw'irk  of  ri'licular  conneclive  liwuu,  which  in  the  cortex  l« 

idoiticfil    with  or  closely  nllicl    lo   adeuuid    tlvue,  but  in  tho  medulla  in 

eoaiMr  and  nior«  open  aiid  to  a  Inr^er  extent  conipn>ed  of  branched  aniu- 

lOBoaine  epithelioiti  nils.    The  mvslint  of  the  cortex  arc  cruwdci)  with  leu- 

cocrlea,  out  these  arc  much  lust  nbumlant  iu  uxd  mora  etu ily  fall  out  of  tbo 

nmulta,  so  thai  in  sections  the  medulla  appears  inor«  tisJDS{)arenC  tlian  iIm 

wrtex.     It  will  be  observed  that  this  arrangement  »  almoet  the  reverse  of 

IW  obtaiainK  in  the  atveolos  of  a  lymphalie  gland,  in  which  the  liner  giant) 

•ubitknce  wiin  its  adenoid  tissue  crowded  with  leucocytes  in  plaoe<l  iu  llie 

centre,  aurroundeil  by  the  more  open  network  of  the  lymph  sinus. 

The  bloDiIvfnels  of  tbe  thymus  miininK  alunt*  the  nciiia  form  capillary 
ottworkt  which.  thou)[h  closer  and  more  abundant  in  the  curticul  than  in 
til*  neduUary  [lorltoiis  of  tbe  lobulea,  have  no  such  »|)ecial  arrenj^ement  lis 
obtnttis  in  lymphatic  glands. 

l.ynipbaiit?  v«»e)s,  abundant  in  Ihe  capsule  and  septa,  are  uuduiiblodly 
(a  oMOOedton  with  tl>e  nuluiancv  of  the  lobules. 

Tbt  nmlullary  Milounce  freifuently  contains  brnJieA,  known  iu"vuiigc»* 
trie  cwiBuW,"  nctuof  oonvL-nlrically  iIiajhiims!  nucleaied  flattened  epithelial 
*~'r  (-tiilhi'ltoid  oellt.  Thev  ap|>ear  lo  nriM-  I'rum  a  pmliferalion  of  the  ttpi> 
%  lielioid  cellii  lining  riiial)  bliKnlvciBL-lH,  and  have  beein  suj>p'i»e<l  lo  1>«  e<in- 
X&«(.tcd  with  the  dvgeuvralire  cliango  by  nhich,  with  obliteration  uf  the 
~W  iiiwb.  the  whole  orvan  ilwindlrs  away  wion  afl^-r  Iiirth. 

IS  0OS.  Prom  ll»c  ih^vniiin  ihcre  may  lie  cxtractetl  by  mc«ns  of  saline  mIu- 
%Joa  a  Ibrm  of  globuli'n  or  n  prolci'l  allied  to  t:tobulin  which,  like  Ihe  eornh 
^ipnnding'  lH»)i«n  from  lymphtilic  glands  or  from  leuoocyles,  seems  to  htn 
Wonie  ■pi-cial  relations  to  the  foniiuliou  of  tihrin.  Thus,  as  has  alreatlr  bca 
Vni<)  (it  '£"2),  a  s<ilutiofi  of  this  globulin  like  bridy  from  the  ihymiis,  injected 
%nt»  the  veini'  will  give  rise  to  extensive  intra- vascular  cloltiiig. 

Tbe  tliymus.  like  the  other  )KM)ies  on  which  we  are  now  dwelling,  is  alao 


I 


I 


I 


eu 


THE    MKTAROLtC    PROrBSSEB  OF  TltK    11«t»Y. 


rivli  ill  cxiriK-livra.    TlitrH  xnnrhiii,  hyjwxnntliin,  luciii,  tnotie,  suvciitEr 
iAh«t  iid<li'  liiivi-  liecn  founil  in  ii. 

Bui  of  wh«l  renllv  taVrc  jiImcc  in  the  IhhIv  we  hnre  no  exact  knowlalu 
Btncf  lb<>  thymiiii  is  Wt  dcvclnpetl  bcfitrv  birtii,  (tisap|)earin)^  after  l)irtlHL_ 
»  nUi  whicti  viirics  much  in  diflercnt  iudividuab  «tu  Mill  morv  in  ditrcrenC' 
kiiidi  "f  iii)imiil0.  nod  being  eventually  i^plaoed  by  Tat  atitl  contiectivn  thmie, 
it  u  obvious  (hnl  its  chief  functinna  are  in  aunie  vny  aesndaied  ««illi  evi>»u 
taking  |>biCL'  befare  birlh  or  in  early  life. 


Tub  HbrroRT  op  Fat.    AmpaeE  Ti»cb. 

(  003.  Gl»tiulc»  (if  fat  nf  rariotu  titn  make  tHuir  aripeaninrv  in  (hi 
alenwniji  of  mivit  nf  tin-  liN^iH^,  in  iniiM-tilnr  ftbrra.  in  vfiitbfliiit   ix\h. 
nerve  c«IIh,  iu  li-tirncyti-^,  ami  w>  on  ;  and  tliv  medulla  of  incvtullai(?d  a». 
tonim*  largely  of  a  ]>fculinr  fatly  innirria).     Boiidct  ihifl,  ivrlaiu  cella 
oonnrctiv  Itrmv  at  various  liniiti,  and  in  varioiu  placw.  b«ci)mi-  to  loati 
with  fat  tliiii  groiif*  of  the  evils  l>croii>e  ]>nic(i('att^'  mwwn  of  laL     Uoam 
live  tiMui'  tbki«  l<>iute<t  with  fat  is  called  adipose  titHue;  lUid  inamM  ot  m 
|Mie«  iMue  uf  all  innnm-r  of  sixes  aad  of  ehnpiv  ailapted  to  th«  Mvenl  situa- 
lions  lire  found  in  various  pafls  of  the  bndv.     Xaoy  of  th«  inUrnnl  orpuia, 
n»tm'  <v]>ecinlly  the  kidneys,  arc  wrapped  in  adipose  timne;  but  th«  larywi 
depmit  is  one  lyin^'  in  the  subcutaneous  tissue,  §  m,  tometimcfi  called  tf 
"  pannii-alus  adipoeus  " ;  and  a  "  fal "  body  is  distingutsbiyl  from  a  "  kaai 
body  chiefly,  l1i<mgh  by  do  means  exclueively,  by  the  amount  of  subcuiaDeoin 
■dinnee  tiuue. 

Of  at]  the  Itwues  of  the  body  Hdi|M«e  tissue  is  ihe  most  flurtuntiu); 
bulk  :  within  a  very  abort  s|Kice  nf  lime  a  lar^'e  antouot  of  ndiptiM-  titui 
may  dtsapjiear, nrnt  nilhin  an  ahuoet  e<}tia1ly  short  time  the  i]uantily  prei^n 
in  a  bodjT  mar  he  wevi-rut  times  multiplied.     When  ton  much  or  too  lit 
food  is  given  it  i*  thi^  .itilKOiiuMit  adijMise  tisue  which  lirst  and  nioai  rapidly 
incrcwea  ArdecrcftAn  in  bulk. 

iSOi.  A  mnall   |>i<-CH-  of  adiivHif  ttMue.  exAniin«i1  under  a   low    [oiwrf, 
ap|K-aR>  ti>  be  niRilr  ii|i  nlimwl  entirely  of  n>undvil  muMi'M  of  highly  refrac 
five  niatcrial,  ctoncly  jiavkcil  (ogeilier.     l'b<«e  ronTKU'd  mnoM-ji,  which  ntain  an 
inU-iiK-  black  with  iMiiic  acid  and  givr  other  rvjuHiom  of  fal,  am  arran; 
in   irrej'ular   lohulot;   between   the  lobule*,  ami    Wincen   the   iudividui 
rouiidod  maases,  mav  bo  acaii  a  small  amouut  of  fibrillaMl  ooiinMtive  ti: 
carrving  bloodvoswis. 

When  the  tissue  baa  been  hartlmcd  and  stained,  and  the  fill  haa  been 
moved  by  Biitveota,  what  wna  provioimly  only  viiibk'  w  a  rounded  man  of 
fat  i«  nuH  seen,  under  higher  {Hiwere,  to  l)0  a  cell,  but  a  dcU  noarlr  tl»e  wbule 
of  the  cell  Kuhstaiice  of  which  has  become  (ranslbmicd  into  a  Ringlo  laifie 
vacuole.  Over  the  greater  part  of  the  cireiiniference  of  the  cell  the  cell 
nihrtnnce  is  reduce<i  lo  a  mere  thin  slietl  or  envelop,  or  cell  membrane,  but 
at  one  part  a  thicker  disc-like  renmnni  b  secit,  and  in  this  ia  placed  a 
roiindiH)  or  ovnl,  often  llatieited  nucleus.  Bedneen  tlieee  f'xt-etHs  may  be 
•cm  a  few  huudl««  of  connective  lisme  fonning  a  eeanly  looee  network,  the 
rounded  mrahiv  of  nhich  are  occupied  by  llie  fat-celts,  the  matrix  uf  ihe 
bundles  amicarinv  at  pliitH-a  continuous  witli,  or  adherent  to,  the  envelii[ii 
of  the  cetU:  onliimry  omnvctivi^-tisiine  corpusciee  are  als^i  here  and  there 
nreeeni.  thouEh  ran-ly  viaibl«  between  ihe  lareer,  50u  lo  I:I0",  fiit-cetl.-<.  In 
injected  sjiecitnens  it  i.i  further  Keen  that  Ihe  connect ive-1  issue  iiiefthworl 
carries  smiill  blood vcswl.-,  which  form  capillary  networks  around  the  groii 


»  an 

tuiH 


TITK   HISTORT  OF   FAT. 


(lis 


(tH-<v\\»  ntiil  even  iiniiiiHl  iwlivliltiiil  c*ll».  After  ilcnili,  upon  iixiling, 
th«  fitt  in  lli«  fitt-ctOU  may  tnlulily  in  irrvBtnl*. 

It  i>  <t1tr)i>ii*  thni  n  /iit-ofU  in  a  etil.  I>c)fltigiiig  to  rooiMicUvo  (iMiti*.  in  tha 
c«n  «tih«tiini-«nf  which  fui  hn»  liocii  ciilloctod  totuch  im  cxliiit  llint  the  cell, 
which  incn>UM«  liirgcty  iti  hulk  thiHng  th«  pmcvM,  is  «lin<«l  nh<illy  tnine- 
fonitcH  into  n  \iikrgc  vtu-uok*  tillcil  nilh  fut.  the  evil  sul>^4iiii:«  licinf;  reduced 
to  n  ihin  envelop  of  the  viu.'U(>le.  thickfineil  iil  one  purl  where  the  micleus, 
thrust  on  oik  Hide  hr  (he  piiilhenn^  Tnt.  'a  pliiced.  Adipose  ti»ue  b  a  cul- 
lecti'>ii  Df  fucli  fiil-cellH  held  t<i;;ether  hy  a  meagre  t|iiiuitiiy  of  TMcdUt  con- 
nenive  lisf^ue. 

Ity  sUidyiiiK  the  devel(>pm«nt  of  s'lipose  tissue  in  the  «mbrro  or  elaa- 
where,  we  ma<ir  trnep  i>ut  the  •Hp\^  <>!'  the  forniMioii  of  ihe  fat-oel^^.  In  tha 
emiiryo,  in  n  aitiiiilion  whi^r^  adipine  imtiti  is  about  M  Ite  formed,  Ihe  con- 
nective tijuue  i»  wen  to  onilutn  n  ntindwr  uf  ttniiill  ntieleated  nW^,  nxitnled 
or  Minii'what  irregular  in  fiirni,  the  irell  HuMance  of  which  at  lir>l  iirt«(!nid 
■10  ii]H'ciiil  chimicien',  imd  coii(nin«  not  iimrc  thiin  what  nmy  he  called  the 
onlinary  lunotmt  of  fiit  ghihiilco  nr  Hplivruli*.  Very  un»t,  however,  ilieiic 
miiiulv  drops  or  8pe<'k»  iticreUH-  in  nuiiiliiT,  the  cell  oulwtanue  at  the  ttanto 
time  inrrenMug  in  bulk  nhilc  n-niniiiing  round  or  iHt-uminir  inon>  dixlinctl/ 
eo,  and  the  eninller  dmps  nil)  to<,'elher  into  larger  oih-s  [l^if;.  17'2].     This 


nr^^ 


l>ir««fn<>N  or  fit  m  OMtfiK'nvR-intri:  Oiua 
I  olili  ■  n-.vr  l»liil«d  bwlnifilsU  In  tu  firolopliuiu : /.  »etll  wilh  ■  ilnitlcUrt"  «ii<liniMnil 
■ilnalu  ilnic*  ./".  huiuanr  liav  Uriii' <1(<>|ii ;  w,  (maulkr  or  ptumwecdl.  i<i-l  )nl  vll>tliillu(i«ny  Ikt- 
■lepoMooi  t,l,  IUIocan>Hiln-aMiH)*ur|iwrl«i  *.  r,  mtwMk  «t  n^lulM.] 

gctot  on :  the  fat  inermning  in  <)UBniily  cunlexom  morv  and  more,  and  the 
cell,  u  a  whole.  bpcom<w  larfiier  and  larger,  the  cell  ^uWance  at  tin-t  keep- 
ing up  in  bulk  wilh  (he  ineieasiiiu:  Ikt,  but  suhMnueutly  cesHiog  to  iiicrcaHC, 
beiuK  ap|>arently  uae<l  up  iu  the  formaliun  of  the  Alt.  Thus  the  ortjfiual 
small  "  nrotoplaamic"  celi  in  at  last  (raii^fomted  in(o  the  larg^er  fnl-eell,  nil 
the  fal  having  mn  t>r;{ether  into  S  veeiclo  ibe  envelop  of  which,  ihick^ni-il 
on  noeeide  to  carry  the  nucleus,  is  tVirnisJied  by  the  reaiDunl  of  the  cell 
substanee.  In  lome  ca$«s,  the  nucleus  iostad  of  heiuK  pusheil  early  on  oiio 
aide,  remaiiH  ceuirul  th->Uk*h  the  ciiUei-lion  of  fat  has  liecomc  coiiHiik-rahlc ; 
it  in.  however,  eveniuully  disj'lacvd.  The  whole  proccm  ap|H-Hn>  very  similar 
tlte  d«pn»iti<in  of  mucin  in  t)vc  cellit  of  a  inucoiM  ^land,  ii  '2^-i :  and  we 
njr  h^  ana)o);v  iulcr  tliat  the  liit-cell  bentmeii  a  fiil-eell  by  the  cell  luaim- 
eturiDg  fat  m  aome  way  or  other,  and  depwitinf;  the  mt  i«>  fumied  in 
iDteratieea  uf  it»  8u1»tani-e.    The  mwi  Mrikiii);  Kupcrficial  distinctions 


016 


TnK    METABOLIC    PBUCKBSKS   OF   THE    BODY. 


seeui  In  he  that  in  the  toacoiie  cell  tlie  cranulea  or  apbemlcs  remain  tViM 
williiu  the  cell,  lieing  sepamted  by  bitra  of  cell  substance,  n  hereus  iii  lim 
cell  the  ((lobulce,  as  tbey  form,  run  m^^ther  uutil  at  laai  tli«y  uniie  iiit«^ 
BiD^le  inasi;  and  further  thai  wliile  iu  lli«  uiucimu  c«II,  evi^n  whiui  nk^^ 
bcavity  luftilml,  a  relalively  lai>.'e  anKiuQt  of  active  cell-Mhctanoe  Mill    f^ 
utiiiiu,  ill  the  Inrcell  a  mere  reiunant  U  l«ft  and  tliat  chiefly  •urrattuitf^ 
the  displaoed  nucl«uit. 

.Some  ob»erven  are  of  uinniou  that  the  oelb  bolougiuK  to  cooiicrtire  ti«a« 
which  thiiM  hi-ci>m«  fut-vclU  of  adipoae  liisue  beloii2  flxclimively  to  iht  ki^ 
which  w(!  i<{H)kv  nf  ii»  pliuuna  cells.  §  105;  but  tnii  i>  dMihtful.  OUhr  , 
Bguin,  while  mjinitling  that  the  oella  which  beoodM  fat-<.'vll»  rMenbltin 
apiHAnino.^  ordionry  ountiective-tiMue  ooqnuclet  and  luav  lik«  thi'ii  U 
branched,  hclicvit  them  iitivorthehm  lo  coiUtitUtA  a  >tiecial  Iciud  at  c>ttM» 
tire-tifuic  corpii»clo.  being  Ivil  to  this  view  by  the  Coct.  that  though  a^ua 
tiasue  i«  very  gt'iKirnlly  (l!«trihutc<l  throughout  the  ooonective  tiaue  oTlU 
body,  it  is  apt  lo  np|ic*r  in  |iarlic>ilar  nitualions,  rather  than  in  otb(n,aJ 
in  some  tracts  of  connective  limtic  never  under  normal  circumitanon  taSm 
its  Hppcaratice.  Others  again  nininiain  that,  nnder  favorable  circuautiacai 
anv  counectivc  conxiscle  nmy  Ix-come  a  lat-eell. 

The  fat  in  the  luterior  of  bones  formiu);  the  yellow  ntarron  appMn  b 
have  the  same  general  sinictiire  and  to  be  formed  in  the  same  way  a  tk 
riM  of  the  adipone  tissue. 

$  SO0.  The  fftt  ihuB  deposited  in  a  fat-ceU  aooner  or  later  dbapiwan.  it 
M  nut  injected  bodily  into  the  aurruunding  lympb-epaces  of  the  ci>ii»MiiR 
tiMUc,  but  itaasoa  away  eillicr  into  the  blood  alremm  or  into  tlie  lymphaiia 
by  tODie  pracesaea  not  as  yet  fully  understood.  The  shell  of  cell  xiUuDa 
wnich  forms  the  envelop  of  the  fat-eell  is  probably  of  adilTerwntiartil  oatan, 
and  may  have  properties  which  assist  the  orajie  nf  the  fat:  but  im  lUi 
point  wo  have  no  exact  knowledge.  The  dtnjtpeanuioe  of  the  (at  a|fW 
to  takv  place  in  two  diB'erent  way*.  On  the  one  hand,  and  thi»  i«ru|ia 
the  mon?  onliiuiry  mcthiid,  the  fat  gnulufllly  diwippcar*.  tittle  hy  littlt,u4 
the  rounded  distended  ve>>icle  gradually  nK<iinif«  the  chBrvclerB  of  a  c«mk- 
Uve-tiBSUC  corpimele,  even  of  a  liituiched  one.  On  the  other  hand,  atjwcitlf 
irben  tlie  diHijipenmniv  in  rupid  and  total,  the  Kpuee  previously  flOfiupted  wf 
At  beeoioes  fillixl  witli  n  ele-ar  Huid  nvenihling  lymph,  the  fat  vesicle  bmf 
tranalbmeil  into  a  tytuph  vesicle.  Thif^  condition,  hnirever.  is  tetii|Kira>7 
only,  the  lymph  is  EiibseiiucDtly  aheorbcl  and  the  vesicle  shrinks.  At  xiam. 
the  emptying  of  llie  cell,  ivhetlier  by  the  one  nioth'jd  or  llie  other,  ia  fiilluW 
Ity  a  rejiivenesceuee  of  the  cell,  the  nueJeus  by  division  gives  rise  toatiwJ 
nuclt^i.  am)  the  cell  <lividc8  intii  new  cells,  each  of  which  may,  under  tfic^- 
prial'*  condilions,  devdop  again  into  a  fat-cell. 

i  506.  1'he  fiki  thus  lodged  in  adiiiose  tissue  varia  aouiewluit  in  ciirafo*^ 
tion  in  various  animals,  but  is  chiefly  compoeed  of  oleiu.  luklmilin.and  ft«M 
ill  varying  pruportiuns,  witii  small  quantities  of  the  glycerin  oumiMUiiikif 
such  ^aiiy  nciib  us  butyric,  capronic,  ca]>ryiic,  etc.,  together  with  a  ItBtr 
lecithin  and  chokMeriu.  'i1ie  "  fat  "  of  one  animal,  that  ix,  the  fat  tbut  ««■ 
laini-d  ill  aili]K«e  thme,  diflerw  from  the  &t  of  another  animal  |>nrtlr  br  tl* 
preeeooe  of  ntore  or  Icm  of  one,  or  more  of  ihcvc  leas  nbondaiit  fau,  M 
ohicdy  by  the  projKirtion  in  which  llie  three  main  fittc,  olein.  paltuiliD.  sai 
rin,  arc  n«i<eetively  pruMtnt  iu  tite  mixetl  fat.  The  melting  jHHBlt  sf 
thne  thrre  fal»  Iwing  dil1<Tcut,  the  nK-lting  juint  of  the  fiu  of  the  bod*  aS 
difler  aoct>nliug  to  the  relative  pnifHirtioiu  in  which  the  three  are  prSMt. 
Thu*  the  subeutaneouc  fal  uf  man  mcll«  at  Imm  !•>'  to  H"  or  higher,  iW 
hit  r^'uncl  tlie  kiilney  being  flrmer  and  not  melting  until  ib"  ;  the  fat  ot  |k 
\h%  inrlta  at  about  'J2',  that  of  tl>e  gooee  at  about  '2^i'.  of  tlie  ox  at 


THE   HlflTOBY   OF   FAT. 


617 


I 


I 


I 


I 


-to**,  And  (if  (III*  flfaeep  at  oO'.  ili«  Itte  nT(iii>iant  tut  of  I)k-  tiini)  iintl  dog 
cvnliiiniiii;  rebliv«ly  mure  oleiii  tlian  ihui  of  die  ox  or  ut'  the  »ti«ft). 

S  507.  Wlwn  w«  conie  to  <»iiEider  the  <iuesti(>n,  Ily  whnt  i>roccMn  does 
thv  fdt  ntttlcc  il8  apfieflrnnce  iu  (he  fat-oetl  J  y^  ar«  brought  (Ace  tn  fnof  with 
oiiicli  the  same  kind  of  probi«Ri  ns  that  whicli  occu|)i«d  u»  in  d<-aliug  with 
Ifljcoeea.  On  the  one  uaiid  we  may  suppose  that  the  fat  is  bruiight  to  th* 
fat-ceU  aa  lat  and  ta  iu  8oni«  way  taken  up  Ity  the  cell  and  deposited  in  the 
c«ll  substance  with  little  or  no  olianiie.  On  tJie  other  hand,  ive  may  stippoee 
that  thi!  fat  is  iflaiiufai-tured  by  the  fat-cell  iu  e»iuc  nuch  way  as  mucin  or 
fW![Miin  is  man u fait unvl  by  a  nim-uun  or  a  );B«irtc  i-cll.  out  of  and  by  means 
of  ila  cell  subntaiKe,  and  that  the  p^><(^t^■«  uf  lutteiiiiij;,  or  uf  produdog  fnt  in 
fai-VRllu.  conHi.itN  mMntially  in  fiiiliii);  and  wi  buildiiigi  up  the  cell  >uliiitanoe 
nhidi  MulM«<iu<!nlly  bpcialcM  down  into  fat,  and  ilm-i  not  i-cmidst  merely  in 
bringing  fat  within  n»di  of  the  cell.  Which  of  thiwA  vinw«  iii  the  true  luie, 
or  bow  fur  »Tf  holh  iImm  opentionit  oirricil  'iti  in  thi-  animal  body? 

In  HupiKirt  of  thr  latter  view  it  may  )>o  uritrd  that,  not  only  ibv  more 
complex  livin<;  MilMlnnoo,  btit.  ii«  wv  hnv<!  nion'  than  nnre.  urgttd,  the  fimplur 
proteid  I'lmnUtiM-nl  of  living  mihcliuici-  obviously  contiiin*  what  wc  may  cnll 
a  fatly  nuliclc.  «'>  that  wi'  might  expect  fat  to  be  formed  out  of  it»  me1«- 
IxJiitm.  And  as  a  matter  ot  Inct  not  i>n)y  in  adijHwe  tissue,  but  i»  every 
part  of  the  hodv,  living  subitaniT  is  continuoiisly  ^nvini;  ri«e  to  and  tempora- 
rily dcpi«iiing  in  itself  tome  amount  of  lat.  and  in  irhat  is  known  as  tatty 
degeueraiion  ibere  Bcema  to  be  evidence  of  the  formation  of  fat  out  of  proteitl 
material. 

On  the  other  band,  we  have  traced  the  fku  taken  as  food,  and  found  that 
tbey  pass  with  com|»nttively  little  change  from  the  alimentary  canal,  chietly 
throughout  the  intermediate  paseage  of  the  lacieals,  into  the  blood,  from 
which  they  rapidly  diaappear  alter  a  ueal.  We  might  infer  from  this  that 
an  exceOB  of  fat  thua  enlerine  the  blood  would  naturally  be  diapoaed  of  by 
bedng  nmply  stored  up  in  the  available  adi[Krie  timue  uith»iii  aiir  fbnber 
chaD)i:e;  we  can  ima^ne  that  the  ful,  not  immi-diatdy  wanted  hy  the 
economr,  paaea  in  some  way  from  the  blood  ti>  the  ci>ntiective  timne  (the 
while  biood-ouqtttaclea  nbiiOi  a)>j)ear  loaded  with  fat  atli'r  ii  nu^\  pomihly 
acting  as  intern»edianc«).  and  that  the  connective  tUaui.- oirpum'lvs  swaltovr 
the  fat  brouftbt  to  them  uA«r  th<'  fii-ihion  of  an  onueba,  not  digextjug  it  hut 
•imply  keeptni;  it  iu  More  until  it  niii  wanted  elwwhore. 

What  di>  expi-rimvuia  teach  on  lhii>  miitU'r?' 

In  the  finti  place,  it  i*  evidiiit  tbnl  in  uii  unimal  fattened  on  ordinary  fat- 
telling  fwHi,  only  a  iinall  frui-tion  of  (he  liit  st^>Tiil  u|>  in  the  body  can  |watii- 
biy  ooine  direct  from  tbe  fat  of  tbo  food.  Iy>ng  ago  in  opposition  lo  the 
tSsws  of  Dumas  and  hiM  Mihool,  who  taught  that  all  ci>n<it ruction  of  organic 
material,  that  all  ncttiul  manufacture  of  living  suht>(ance  or  even  of  it# 
organie  comtitui-iils,  was  conlined  to  vegetables  and  unknown  in  animals, 
L.iebig  shotted  that  llw  butter  present  in  the  milk  of  a  cow  was  muck  (greater 
tluin  iMuld  Iw  acconuted  for  by  the  scanty  fat  present  in  the  giMS  or  other 
fixlfler  «he  consumed.  He  aU-i  iirgeii  n»  an  argument  in  the  same  direction, 
(bat  (be  WAX  produced  by  hecH.  which  though  having  a  diiri-reui  compfHiiiim 
from  fat  nuy  ue  used  as  an  aunloi^y.  is  out  of  all  pro|Hirri<in  to  the  »nx  or 
allied  budiea  contained  in  their  food,  coniisiing  as  this  duvi  chietly  >>f  .-oi^r. 
And  it  lias  since  been  shown  i»  many  navs  that,  in  fattening,'  HiiimaU.  the 
i'nt  accumulated  iu  the  body  cannot  lie  accouuteil  for  by  the  fiit  nhicli  has 
twM)  taken  in  the  fowl.  It  lui»  \>n:a  ]>ro%'ed  hy  dim't  analyxi^.  Tliuii  of 
two  young  |Hga.  aa  much  alikt^  u^  jKMMble.  of  tlw  utinw  lilier,  om-  niic  killed 
and  analvxed,  the  anHMinl  ol'  fat  in  the  body  tmng  among  oihci'  thingii  deter* 
min<-d.      The  other  wan  futtenetl  for  a  certain  length  of  lime  on  fivnl  whoM 


THE  URrAnoLK^  processks  or  tub  bohv. 

oonifNwdon  woe  kuown.  and  theit  killed  wkI  aiialiried.     it  irns  fotiixl  it^^ 
ftweviTT  100  (>ans  of  lat  in  the  fooil  472  parts  i<f  fat  were  sioreil  uii  in  ».|, 
body  duriii(*  the  fiilteDiuc  period.     It  it)  i;l««r  UuU  &l  may  he  fvritiFi)  in  \^ 
budy  out  of  3»mething  uliich  is  nut  fat. 

$  509.  Tliere  ara  twg  iH)a*il>l«  >oiirceii  of  ihu  maniifacturad  fiu.  Tbf  t^^ 
boiiydrau*  of  the  foiid  rorin  on«  itource.  In  trattinj;  of  digeMion  (i  2"^ 
we  referred  to  the  pombiliiyof  cHrbubydnile*  during  dijcuMton  in  Uik  aliinn. 
tary  canal  liuoaniing;  by  fernientution  nriivcrtiiil  iiiii>  liutvric  wid ;  and  «i 
(UKgWted  that  higlitr  iiml  mon-  coiaplox  miMii)>cn' cif  tlK)  Mcnvfiuiriol 
Mnu  miglii.  bi-  <il>tnii]<il  oitt  of  carboliydnttaa  by  cuinowlMt  aBalnnn 
changes,  mrmi)  im,  hnwvvcr,  not  in  tbe  nliaMnurv  canal  by  m-  i 
foreign  orgiiniwd  fcmicnl*,  but  in  tbc  tiwuw  tbrougn  tb«  iiclit-ily  <  n 
tiwnt^  Chi^'mwlvt'i'.  Wv  ciinnnt  na  rot  inioo  out  the  Kiept  nor  cao  vt 
dctiniUrly  piiiiit  to  uny  pnrlttrulnr  tiwucx  other  thtin  tho  fnt-odls  ibtuutlnt 
m  the  ivatf  »(  on/  Kuch  changt«.  But  ihvi'o  can  be  »u  doubl  thai  oub*- 
bydrato  inst«rinl  duva  in  Bomo  wiiy  or  olb(<r  give  riso  to  Int.  A  rarb-diydiM^ 
diet  is  iho  kind  of  diet  niiist  cfScacioiu  in  producing  nn  nccuniuliUioti  U  hi 
in  the  body ;  sugar  or  starch,  in  «onu*  forni  or  olfa«r,  is  alwayt  a  )irj» 
GonslitiiODt  of  ordinary  fiitteniug  fbod». 

Another  source  of  tnt  is  to  be  found  in  the  proteids.  We  hanMCal^ 
the  urea  of  the  urine  pntctiunlly  reprewuia  the  whole  of  tho  nitrum*  ■biek 
pHBH  through  tbe  body.  Now  in  any  given  qunntily  of  urea,  tBetniOM 
of  OAfbon  U  far  le«H  than  that  found  in  the  ijuuntily  of  proteid  CMHaioia; 
the  same  amouni  of  nitroj^'ii.  Thus  the  peroentajKe  compooition  of  thttw 
being  ra|)t;eiively, 

Sulpter 

1.13 

100  gnus,  of  urea  contain  about  ns  much  nitrogen  as  'tOO  gtau.  of  praletd; 
but  the  'iOO  gnus,  of  proteid  contain  \'-i3  grniiii.  (15!t-:!0)  more  oarboo  thu 
do  tbe  ItH)  gruis.  uren.  Hence  the  300  grms.  of  proteid  in  [laasin;;  ihniii^b 
the  body  and  giving  rise  to  100  grms.  of  una.  would  team's  b«hind  13S  grni. 
of  carbon,  in  some  combination  or  other :  and  this  surplus  of  carbon,  if  the 
needs  of  the  economy  did  not  demand  that  it  should  be  tuininliately  «id> 
VL-i-td  inti>  carbonic  odd  and  thruwn  olF  from  the  body,  might  be  depooitetl 
tonicwliere  in  tbe  form  of  fat,     It  ha»  been  calcuUie<l  that  in  tha  way  10(1 

SniK.  «f  proteid  food  might  funiidh  -I'i  grms.  of  fat.  We  have  already  «eea, 
treating  nf  tbe  action  of  the  piLULTeatit-  juice  (§  249),  that  tlienr  U  evi- 
dcDOe  of  a  fatty  element  (vin.,  leuciu,  which  in  amido-capn)ic  acid,  and  to 
belongn  to  the  fatty  acid  seriea)  being  tbmwu  otf  from  the  oimplcs  protvid 
comjiound  in  the  very  pniccaa  of  digestion :  and  though,  a^  wc  havi*  Miid.  ire 
have  no  proof  iliat  tliiii  action  nf  panci'uatic  jutce  tabtB  phic<>  largely  in  ibe 
Dornnil  boilv,  ito  viiluit  il>  nn  cxampli;  i*  amu-.  the  lesa  important. 

Soma  obMrveiv  have  pnshtHi  tbii  vi<-w  nf  the  poiduclion  of  (at  tnit  of 
pn)tai<b  so  far  os  U>  inHU>t  Ihnt  all  tbn  fat  formed  in  tbc  bmly  arimw  in  thi* 
way  out  of  prot4.'id  nmtiirinl,  and  thiii  when  carlMhydrati-  fii-iil  giw  rbs  to 
the  formation  of  fat  it  duc#  ki  lir  ^bidding  from  oxidation  liw  i.'arbon  mmety 
of  the  protoi<l  food  taken  at  tlK>  xamc  time  and  tbiu  ixinnitling  it  to  ha 
Stored  up  as  fat.  The  carbuhydrnic  it»elf,  they  ari^iie,  never  becomw  fat  but 
its  iwesencc  allows  fat  to  be  formed  out  of  protuid  inatorial.  Thw  view  hac 
obnoualy  a  very  imporlanl  eo'rtiomicnl  twarin^.  viiice,  if  it  Iw  true,  it  is  use- 
less tu  inorease  the  carbohydrate  miiteriat  of  liiiid  for  the  purpose  of  fatten- 
ing, unless  a  siithcient  pniportioo  of  proteid  material  bo  given  at  tbe 
time. 


t^rtntl. 

llTlLtnp!!!, 

Oijsen. 

Nnraavn. 

Urea 

2t).00 

6M 

36.G7 

4i(.«7 

Proieid 

dS 

7.30 

33.04 

lfl.S3 

TIIK    lilSTORV   or    FAT. 


619 


I 


Tli<-  view  homovcr  liii»  Ihi-ii  iimvcti  to  be  uDloiitiblo  br  tc-vt-rnl  mvo«tifrK- 
oil.-'  (-urrinl  out  uti  iliirrmii  atiituuls.  It  h)i«  bcrii  kHowh  iltnt  itii  nnimnl 
rii|Hi||y  tult^notl  on  ■  dk-t  coiMisliiig  of  protcJds  with  much  c«rl)o)iy<ln>(«  irill 
HUiix-  up  far  mwn  fiit,  thiui  (-mi  puc^ihly  b?  tccounlcd  I'or  bv  ti».-  pri>U.-t<Iii  of 
thr  ■!)«.  Thus  ■  do^.  iho  flit  in  whote  body  hud  beeii  reduced  to  ft  miniitiuni 
bjr  starvation,  wiu  fed  for  a  ncriod  on  measured  iiuuntilies  of  proteids  iind 
enrbobyilmica,  and  killed.  'I  he  nmoutit  of  fat  found  ullerdenih  in  hix  body, 
mnkitij;  full  nllowiinoe  for  tlie  fat  which  remained  n>W  the  slarvntion  and 
for  ibc  fat  nccotupanyiuK  the  proteid^  in  lh«  meat  };iven  ah  food,  was  futiiid 
lo  be  lar  more  than  could  be  supplied  by  the  carbon  in  ihe  [ir<itei<U  of  llie 
fomi.  «Tni  nupposinf;  that  every  ^oi  nf  thow  prun-ida  whirh  itid  not  )p>  to 
mnke  up  tlie  iocreaae  uf  the  prot£i<]  "Detih"  of  tin-  body  taking  plaie  during 
tl>e  fattening  waa  axA  fur  the  piirpooe  »f  fiiriiiing  fnl.  Simihir  experiment 
on  ^eese  ai>d  pi«^  have  led  to  simdar  nvnltn ;  ami  if  fal  he  fi>ri»e<l  in  thiit  , 
way  in  the  IxMliiii  of  <wrnivora  and  nmnivoru.  wc  may  Xir.  sun-  that  ihti  Ktnie 
holdii  kixhI  for  thu  bixlio  of  h«rbiv(ira.    Wr  may  therefore-  ooiirluile  thtit  tilt 

teai)  Ik  miinlructcrd  in  the  body  on  tl>i-  one  luiiid  out  of  proleid  material,  and 
on  the  other  hand  by  nomc  direct  convention  of  cnrbohydralM. 
S  609.  Ii  ifi  *'k-ar  then  that  a  const ru el  ii>n  of  611  iloctf  occur  in  the  Ixuly 
S'luifwlien.'.  What  limitB  run  wo  plaw  on  the  degrco  to  which  thii"  wimrtrun- 
litm  in  rBTTtc<l7  When  the  fomi  containe  Miflicient  actual  tat  to  act--ounl  for 
the  fat  ftnnil  up  in  the  Imdy.  does  any  comtruction  of  fat  lako  placi;?  In 
tJM  Bret  place  w«  find  llial  wht'n  the  fooil  contains  abnormal  laii<  <uch  an  llr(^ 
Dot  pn-aciit  in  the  body,  snennuceli  for  iiislAnce,  or  orucin  (from  nipe'lpre.d 
oil),  them  Ikla  are  not  to  be  found,  or  are  found  in  very  email  i)uniilitv,  in 
tho  fat  whidi  M  Stored  up  in  the  body  a^  n  eonaequence  of  a  larife  supply  of 
that  food.  In  the  Becond  plaeewe  may  call  to  mind  the  »tatement  previously 
made,  that  the  compoeiiion  of  lai  varies  in  difierent  animals.  The  fat  of  a 
man  dilfen  from  the  fat  of  a  do^,  even  if  liolb  feed  on  exactly  the  same  fuwl, 
fiitly  or  otherwiw.  Were  llie  fat  which  i»  taken  an  food  si«re<l  up  as  adi- 
pose titwie  directly  and  without  chanjte,  recaurse  being  had  to  other  wourec* 
of  food  for  the  coiutrudiim  of  fat  only  in  ctM^  where  the  fnt  in  tlie  food  wna 
deficient,  we  *honId  exiM-ct  to  tind  that  the  nature  of  the  fat  of  tho  Ixnly  would 

I  vary  Rfeally  with  the  AhhI.  .So  far  fmui  tliis  being  the  ca«i,  tlirect  exi>eri- 
tuentH  abowitthat  the  fnt  of  ihedn^  in,  ak  far  a»  composition  iicont^niiH^very 
lanrely  independent  of  the  ri>od,  tbnt  tho  normal  const ituciilsi  of  fal  make 
tlKir  a^giV'arance  very  much  iw  ufual,  and  in  very  much  their  appntpriate 
pro]wrlton.  though  their  profiorlion  in  the  fooit  niuy  largely  vary,  and  ibouvh 
some  of  ihem  may  l>e  wholly  ahM-ni.  Thus  in  one  cxpcrinj«tt  the  fnl  of  the 
bodyooiitaincdou<Mtdernble<|iiantitit«of  stearin  after  a  diet  free  from  slenrin, 
■od  in  anolber  preserved  the  normal  amount  of  olcio  after  a  diet  free  from 
oldii. 
Of  course  it  is  quite  possible  that  in  such  cases  as  tbeee,  ihougb  tlieslMriu. 
or  the  iddn,  when  ab<ent  from  the  fond,  was  in  some  way  or  other  constructed 
anew,  yet  at  the  same  lime  th"se  ooiuttituents  which  were  prcaeut  were  simply 

IHiTL-x)  up:  and  the  small  ^uautily  of  erudn  prevnt  in  the  fal  of  the  body 
after  feeding  on  erucin  must  have  h^u  dinvlly  atore^l  no.  Ho  also,  when  ail 
nnimnl  is  rapidly  fattened  on  a  diet  cmiiiistink;  of  a  small  quantity  of  proteid 
•nd  a  ltiT\^  iiuaniicy  uf  fal.  the  amount  of  fat  slore<l  up  may  l>e  too  great  to 
havo  nime  fnmi  the  prott-idri  i>t'  the  dii-l,  in  which  eaaa  we  may  infer  that  it 
WM  the  actual  fat  of  the  f-'od  _.>imjtly  deiKuiCcd  in  the  fal-cc!l.-<  of  tht?  body. 
But  «v«-n  in  thii*  an^;  lU"  more  ilistinctly  lu  the  olhent,  it  ia  also  o|>vn  for  us 
t<'  sapiMiKn  that  all  the  fat  taken  a<  food  was  tn  some  way  or  other  disjKwed 
'  it,  mod  that  all  the  new  fal  which  ma<le  iin  appcamnoe  was  conslructeil  anew. 


620 


Tll£    METAHOLIf    PttOCKflSKB   Of 


Ami  Ihe  latter  vi«w  t«  mora  [wrhH[iti  in  Imnnony  wiili  lUc  h!i>i<>l<ii;inil  Udt 
jin'vioiiBlr  ineiitiuiM'il,  iia  irell  u  KtimHirhvl  ■>}■  (iitivr  •.>irisiiiernli<>tii>. 

At  tite  present,  ho  wo  vcr,  w«  Rwylx'  wiiii'iit  witlitiM-  l>>ll<>wiiifr  ooncliuinot 
I.  Fat  is  actually  foniH^I  in  the  animal  bixt)-,  and  cl>i>  Ikt  pmwnt  «t  aat 
Rioiueol  io  ihe  boclr  i*  doI  ucliiaiv«lv,  if  at  nil.  >iit  nwrxly  *t(>r<n>)  ufi  fmn 
tiie  fat  of'tlw  fiMid.  '2.  The  nr^ii  vlpntcntja  of  iIk  iMnly-fnrtncH  fnt  ntay  h- 
e\ipi>lie<l  i-iiliiT  from  c»rlv>hyilrate  fnoH.  or  ftxwi  ll>c  wrboii  i«ur|iliiit  of  (ii*- 
t«iu  food,  itr  from  fiiU  Utkeu  at  TocmI  whicli  ar«  itui  tlto  natural  omuitituuit) 
of  ibe  hrxly-fal.  3.  Tho  fnl  tU>mi  up  npprare  M  fat  gmiiulM  or  dm^ 
dep()6it«il  i»  tho  G<^l  etilMtance  of  cortAin  crlle.  aod  the  increme  of  th«  fat  a 
tlio  cell*  t*  uocompanii-d  lirsl  l>y  a  gniwth,  ami  MihmquMttlv  by  a  oonwni^ 
tjoD  of  tbo  cell  ButMitaDoe;  btit^  aa  in  the  analogmwcaw  o^  f;lv'»!r«ti.  ilirr> 
it  IM>  complate  evidence  to  »liow  nhMher  the  fal  granule*  irhicli  appear  ir* 
simply  depoailed  by  the  cell  gtibatance  in  a  more  or  Icea  niecJM>i)ii^nl  maawr. 
without  their  forming  au  iulei;ral  portion  of  (hat  cell  eub»t»i)crr.  tho  diicf 
'  t)ic  mniiiifacture  of  the  fat  liavinf;  been  |^e  throueh  «leewb«rh  m 
ility  itrbe  from  a  lireaking  up,  a  fuoctiooal  metahoTiMU  of  tb*  OtH 
«ub*iaiii.-e  of  the  tat-cell  ilaelf;  the  latter  view  ia  uu  the  whole  however  tW 
ini>ni  ]>rob<ible. 

Thr  Maiiuary  Gi^xd. 

S  ftlO.  8itico  milk  i«  a  nerretioii,  ani)  indeed  an  eicretiun,  the  mammarr 
glaiid  ought  mA  to  )m:  cIimxhI  ut  n  mcialtolio  tiMue.  ii>  the  limited  mewilaf 
we  are  now  attaching  ^>  iIumc  wi>rtUL  Vet  the  n»ctatM>li(-  piienoroena  gtrlnf 
rise  to  tW  M'crrlioD  of  milk  are  ao  marked  am)  dirtimt,  have  ao  many  analu- 
yiea  with  the  purely  mntaholic  cv<-n1«  which  tnke  i>lace  in  atltixiao  tiaaucaaJ 
ao  alrikiugly  illuNtnitc  m<'tiib<ilic  cvcniii  in  genvrel,  that  it  will  bo  lunni  ooih 
venieni  t«  coDnidcr  the  matter  here,  rather  than  in  aiiv  otlwr  <s>Dni»cUon. 

The  mammiiry  gland,  formed  tike  a  sKcnt  gland,  o>  which  it  inny  be  mt- 
■idered  an  oxireme  developfHeal,  by  iin  ingrowtli  of  tho  Malpighiiin  larirr  of 
tho  i^>idermis.  ie  acomponod  racemoM  gland,  cDitatructnl  alb-r  tlm  fn-neml 
plan  of  »iioh  a  ^land  ai>d  tbiifl  oompoeed  of  branuhing  ductn,  cndin):  in 
MCrciing  alveoli. 

The  whole  arg»a  isdivtde^l  by  conneelive-tinue  m|Mii  into  a  mirot>«raf 
lobM,  in  woman  alxwt  iweutv,  each  of  whioh  poeeeMts  a  dtatiuel  •lart.  umo- 
iug  )iy  a  »>p<trate  urific«  on  to  Ihe  nipple :  the  Ktnod 
in  (hot  is  uot  a  single  itland.  htit  Mvi^rat  itLmiti 
IxMind  t4)f[elher.  IC»«h  lobe  U  (\irthcr  divirled  bf 
eonneclive-liaiUe  se{>ta  into  smaller  loliee,  and  tin 
diviaiuu  it  repeated,  the  la&t  diviaious  niarkiuK  iiut 
Muall  mtuHW  called /n6ti/<'^.  [Fiji-  1*3.1  The  nuiia 
dnct  Mipplyinjf  a  lolw  bratiehej  into  a  numlter  of 
uuall  ducbi,4«eh  of  the  ulltnutedivbions  »f  wtiMi 
undit  in  a  lobule. 

Witliiii  the  lobule  the  duct  divides  into  u  oumher 
of  rvluiively  wide  tubule*  wbieh  pursue  a  warv  or 
oven  tn!fi4?<l  oimne,  aitd  liear  drep  latn^  biilEiBff; 
tbi-Bv  nr.^  held  bi|fether  by  n  rtnn|»T«tively  lAigu 
aroounl  of  ooiinecltve  liMU«^  Ilrncu  in  a  motion  of 
a  };land,  oaoh  lobule  appean  u>  U'  eonipoaett  of  a 
nunber  ot  irregularly  ruund  ipfloee  or  abitoli,  which  are  tlw  eertiona  of  the 
tubules  and  the  bulgings,  ami  which  at  some  pnriA  of  tl»e  aectlon  apjiear  bi 
be  eloeed  s|»aeee  and  at  others  to  communicate  with  oadi  other,  or  witli  a 
pasn^  in  the  centre  of  Ihe  lobule  leading  to  the  lumen  of  the  iluct.     The 


lino.  in. 


■'JJ      -  \ii^M 


TnaMATiDN  or  rcMtHdt  o» 
Uii-K-iM  CT  III  a  Ckiwnui  0* 
PMi.tnia  (trromauiatmitei 
IBjedtoa ;  •ntuaed  t  luntk)] 


iv  ar-ANfi. 


R21 


nppi.'araiicce  thus  prcsonicd,  nt  lonM  bjr  h  Hiickliii|^  glnnd,  o^ntrmi  iiiark«<lly 
ivilh  ihime  of  aa  ordinnrj  i;liii)i),  suci)  as  the  Mibinaxillary,  by  reason  nfthe 
iMge  alveiili  iriili  lh«ircutispicuously  wiije  lumina.  often  oooupied  by  remains 
of  the  milk. 

The  ductH  conuets  of  an  epithelium,  rostio);  on  a  connective-lUaue  baaia 
which  in  the  c«ee  of  itie  main  ducia  ia  etrenf^hened  with  loDitiUidinally  dia- 
pcMxl  plain  muscular  fibres,  coiiiiimoiiA  uritti  the  musmilar  fibres  present  in 
tJi«  dermis  of  the  nipple.  Over  i]>e  gn^ter  part  of  their  oourM  the  diiciM 
mn  lined  itiih  a  single  Layer  of  columnar  e|>itbelial  cellH,  Init  ul  tite  in'iuthii 
of  tbe  amin  <)ucta  un  ilie  nipjile  (boe  paw  into  an  epidt-rnilit  nf  mora  titan 
one  layer  of  Hattened  fnWs.  JiihI  liefore  opentnjiC  on  tii  llie  i)i|>tile  cju-h  nutin 
duct  i*  widened  into  a  llaak-«)ia|ie<i  (.'ularjjiement.  At  lb«  teriiiiijali<ni  of  tlic 
small  <luct«  iu  the  lobulM,  the  i.>oluiiiiinr  irpithvliuw  ih  said  to  u'vr  plsc«  to 
flalteiicd  cdb,  m  thut  lh!«  |iart  •>)'  the  duut  iniglit  be  vidl«<)  a  duuinle  oorrfr- 
epooding  to  the  ductule  uf  a  »alivary  kIidiI. 

It  SU.  Th«  apiic-amneeM  jinweiited  liy  the  atvmli  dllTur  widelv  according  ne 
the  ^land  i»  oix*  whii'h  Ih  being  used  ISir  xurklin^,  ur  '}*  one  iii  a  rrating  or 
duTutant  cMHlitioii,  that  t>  to  Miy,  lH'r»n-  any  [irc^'iiancv  at  all  linH  tnk^-n  pTaco 
vr  in  tbe  inlerval  bi-twM'ti  two  HUckling  |)cri<iilH.  In  thi-nucklitij;  gland  fach 
alveolae  oiHuiii I »  of  n  bawntent  inomUram-.  prHH'iiting  ibi-  ii*iial  chuniotera, 
lined  with  a  nnglc  lavor  of  colla  leaving  a  wide  lumen :  but  the  ap]>eaninoee 
preeented  by  th«  ocIIh  differ  from  tini<r  to  time  according  to  cimitnMMwee 
and  are  not  the  snn>e  in  all  the  alveoli  nt  tlic  same  time.  We  may,  Imwever, 
di8tint;ut«b  two  conditions  which, tinop  they  aeeni  to  correspond  to  the  loadetl 
and  discharged  condtliouN  uf  an  ordinary  gland,  we  may  call  the  lo«<lcd  and 
tbe  di8charg«d  pbaee  respectively,  conditions  iatarmediate  between  the  two 
being  met  with. 

Iu  tbe  diBcharml  phase  ibe  alvetdns  is  lined  by  a  layer  of  low  cubical  or 
eTGD  flattened  oeUs,  so  that  the  relatively  large  am  of  the  alveolus  is  almmt 
wholly  Dceu|ned  by  the  tum«n  in  which  fiome  of  the  conslituenis  of  the  milk 
nutyalill  be  retained.  Kaok  c«ll  oonsisU  of  granular  cell  substance  in  vrbich 
in  placed  ■.rounded  or  oval  nucleus.  Sometimes  the  free  edge  of  the  cell  is 
jagpid  and  uneven  as  if  a  portion  of  the  free  border  had  been  torn  awav. 

Ill  a  fully  loaded  phajie  ili<^  snpearanoes  are  very  difiereut.  The  itlveoliia 
'  is  now  linul  irlih  a  layer  of  tall  eolumiiw  cells  projecUng  unevenly  iulu  the 
luniDii,  ihv  outline  of  which  ia  correapODdinely  irregulsir  and  the  arva  of 
wlikli  is  mueli  n:<luceii.  While  the  broader  base  of  each  cell  rwu  on  the 
bcaeDMnt  membrane,  the  other  end,  fuinical  or  irregular,  riretohes  towan)  the 
oetitn<  of  the  lumen,  [natrnd  of  one  nucleus,  two  or  even  more  are  now 
present,  tiw  well  formed  and  normal  being  pUoed  nearer  the  base,  and  the 
[  others,  ottxa  tthowiug  signs  of  breaking  or  degeneration,  nearer  tlie  frev  end. 
8)>mc<lmw  oDtistriclioiia  are  seen  whereby  the  free  peripheral  portion  of  the 
cell,  including  one  or  nvore  of  the  nuclei,  is  apparentlv  being  !«i'{iamtcd  from 
Ihi!  basal  |H>r1ion  in  which  the  reniainiuK  nucleus  i*  Imaged ;  and  occai(t[>nally 

•rtions  or  j'rw^'mentM  of  cells,  nucleated  or  nueleualeHii.  may  be  mn^i  lying 
II  the  cavity  of  the  alveoltu.  In  thi-  cell  substance,  <s)Hxrially  towan)  the 
free  border  of  Ihr  cell,  are  numerous  oil  gliibutM  ef  varioiiH  him*  ax  well  as 
granules  or  panichti  of  other  nature;  some  of  the  lai^^r  oil  globulca  may  be 
seen  projecting  from  tliCKurfnceas  if  about  to  he  extruded  from  the  cell;  and 
in  the  cavity  of  the  nlvoliuioil  globules  with  a  thinner  or  thicker  coating  of 
cell  MtlwiaiK-v  are  I'rcipKiitly  prtaent. 

Betweeu  n»ch  a  fully  loatkd  phase,  and  a  completely  ditchargcd  phase, 
TttriMM  ioteroMdiate  condiliun*  may  bo  obaarvcd.  tbo  cells  being  of  greater 
or  !■••  height,  ooataining  laiv  uuclvtis  only  or  more  tlian  one,  the  cell  sub- 


C 


S22 


THE    UETAUdLIQ   fKOCBSSBS   VF   TIIS    UODl 


■laiKe  oi-cu|Mecl  uiih  n  fiw  or  witli  ntiuiy  <iil  g)ubul*>  iidcI  otJivr  gnuslA 
ud  iIm  Ttw  bonier  itiorc  or  less  JRg^ifMl- 

Futtin^  llieee  facie  ia|tc4l>er  we  tiiav  draw  the  fullowin^  coiii'lti^iixi.  wUrt 
(•  aii]>p<irlc(l  br  Alber  evitieiKv.  ati  to  the  chnngee  in  iIip  pl>ntl  whi^ 
character i He  tl»e load! ui;  mid  lliedi^M.-lini^'e.  UurJD^  Inndiiig  the  Ifiw  fliiiln«J 
eel!  (if  tbe  dbcliorx^  alveolus  ^'nin-^  m|>idlj,  cloni^Bling  into  the  cvliodriol 
lunn,  and  tlie  nudeus  giv«a  birth  to  two  or  more  neir  midct.  MMii«hil) 
KClivc  iii«ta)Mli)>Ri  is  f^ns  on  in  the  cell  tiub«t«nce,  depoeiia  of  fat  as  well  ■ 
of  oth«r  fulNilanvoii  an-  (alciiiji  |ilaue.  Ily  vhta  seeins  to  be  of  the  luiiiinof 
an  unitrhoid  innri-iueiit,  Nome  o1  the  oil  friobulee  (and  potnibly  othtir  tnailcrf) 
arr  fxirii<li-d  fniiii  th«  i-cll,  miid)  in  the  name  way  tbut  an  aiiKi^lM  (■stnxla 
il«  rxcrcmeot.  But  bc«Hle«  ihi*,  a  diviaiuii  of  tbe  cell,  ihnt  ia  »  nr|Mtnit»<io  J 
[lari  i^f  ilin^ll  sit balfiticc  with  nu  included  nucleus,  la lcei»  jilai-*'.  the  ilnuirbMr- 
cell  thuH  (liriiwii  off  jmming  inm  iIh-  iilveidti*  l»  form  |Mtrt  iil'  tbe  milk ;  <* 
n  tiiiddiiig  III'  ibf  cC'll  ooc'iini,  |>ari  of  tbe  cfti  without  a  nuclr'us  lioiiif  mhU' 
liirly  caet  off  and  iiiidiT^"iiiff  a  Kimiliir  fiU'-.  lii  olhcr  mi)r>l!>  the  i>«>«-rrtiii( 
cell  gixiwi.,  liHuh  iiM-lf  wiili  nielulHilio  |inidiii'tJi,  luid  wlim  lotidi-d  i^i-ri^  of 
binlily  pun  of  iiwlf  to  coiiliihiiic  to  ihetecrvtJnn,  )>Mit  of  tlw  ■<  hu 

alway»  reiitinin^'  a  niicIiiiF.  n-nminitig  behind  lu  order  to  M-i'ur>      '  tit 

Krowib  aiHl  further  Hivrclion. 

I1ie  trecreli'in  of  milk  diHtMH  from  »uc)i  n  Hccrtftimi  Or  that  of  anliTs,  aai 
approacbo  the  formation  of  wbuni  (^  4:tK)  intuniiiich  ax  tho  traiiafarnwi 
c«ll  substance  ie  shed  bodily  to  riinn  part  of  the  milk.  W«  mv  fi>rm  pan 
of  the  milk  becnuee  thi«  RtoBS  ntodv  of  Kvcrctioa  w  «eooni|uiutc<l  by  the  mm 
ordinary  mode.  The  cefia  are  at  llic  t»nw  tinw  in  ibe  uioro  ordinary  war 
dUcbar^u);  into  the  luines,  water  holding  citliito  and  other  confltiiuent*  ii 
solution.  And  the  peculiar  fcalurceof  niiik,  j»  we  bIiaII  we  presently,  cvm- 
f*)H>Dd  to  ibis  double  mode  of  secretion.  I'erliam,  however,  we  ooj-ht  nut  u 
call  it  a  double  mode,  for  tbe  one  luethwl  really  {MtaNa  ineensitily  lotci  tbt 
other.  The  discharge  of  sodium  chloride  in  solution  from  every  kind  o( 
^laud,  of  mucin  fVum  a  uiticous  ffland,  of  oil  globulce  with  n  pnuid 
envelop  from  u  moniiuary  ({land,  and  laMlj  of  nucleated  tondifd  cell  nib- 
■latice  from  the  mammary  gloixl,  preaeni  so  many  different  phnew  nf  the 
Mme  act  of  net'TVtiun. 

ji  612.  The  dormant  rcMing  mammary  gland,  that  for  tUKinnn.-  of  lo 
animal  nbich  bua  never  bi^t-u  preitnani,  is  much  Hmaller  than  a  6iickline 
gland,  owing  to  llie  alvi^di  being  liotb  muidkr  and  lea  DUUH'nxi*,  Kacii 
Mlrc<>lm  moreover  is  nut  n  mvity  lined  with  a  i>ingl«  layer  of  efiilbetiiini.  b«l 
a  aolid  cylinder  or  iiiiwn  of  iHMnjiaratively  nmnll,  roundeil  iir  (mlvhcdnl 
cells.  So  long  lu  iirvgimiicy  tlon  not  occur  the  growth  of  tliiiW  is  escHcd- 
iiiglv  xluw,  and  tne  produclH  of  sucb  metidioli.'>m  iw  goui  on  in  ibein  air 
ciirrtcd  away  by  the  blood,  so  tlint  under  iiorniul  circunMiaiioM  no  sectvliun 
tiiki«  place. 

When  jin'gnancT  iKcura  m|»cl  growth  of  the  mamma  takca  place,  atitnem« 
Ditw  alveoli  Wing  formed  by  budding,  but  nil  for  a  lime  rvmniDing  aolid 
oylimleni  of  rvllM.  .\t  the  approach  of  the  birtb  of  tl»e  uflsprini;,  th( 
oentrnt  celli'  undergo  metnWIic  changes,  ee|iecially  a  fntty  tranaftrmulios, 
and  either  Iwforc  or  at^cr  birlh  ar  cast  off,  leaving  a  single  layer  !>■  line  tli* 
olveult  and  to  carry  no  the  work  of  secretion  as  described  ahuvi%  It  is 
generally  mp[><:ccd  that  tbcsi'  shed  oelU supply  itic  Mmlled  ** cobiurum  <ar 
pusolee'  charactorift.ic  »f  the  tirst  milk,  of  whii^li  we  shall  sjieak  prcMUtly- 
At  the  end  of  laclntimi  no  abwrptiotl  of  nhhq  of  ihe  alveoli  take*  plMe; 
and  in  old  age  still  further  aliaorplion  goes  on  with  great  dituinutioii  of  | ' 
luiniuo. 


i  SIS.  Tli^  cntiDcrlivc  tuaiie,  Juiniiit!  lu^-ilier  the  lubules  of  various  eues. 
Mtrriiuailini;  t)i«  tdhiile*  and  ruiiDiii);  in  be(vre«D  ihe  girojediii?  bliod  eii<b  of 
liw  «]Tmlj  tsjtliin  tlie  1ii1hi1«<.  is  rich  iu  bloadi'«Me[s  wliu-ti  funu  cnmllury 

Iunirorkc  ntuud  llw  ulveiili :  u  nlan  carries  a  c<vmiilcra))l«  iiuinW  of 
lyni|<b»lii-  voaela  wliicb  ariK-  iu  lyiiij>b  ^iiaoM  arouuil  the  alveoli  aod  else- 
«bef«.  L«ucocyia  are  uuiuerouit  in  thb  i)|)ac«t)  of  tbia  (xmuectire  tiafue, 
and  aame  of  tbain  may  make  llieir  way  tliriiutfb  Ihe  basement  luembriiue 
aad  between  Ihe  aM-retiDg  cello  into  tbe  caviliea  of  liie  ulvculi  ami  »>  appear 
In  tbr  milk. 
i  514.  77ir  Nfliure  of  mUl.  iluiuaii  milk  baH  a  upecillc  (irarity  of  fVom 
l<y21f  ((>  11^*14,  aitd  when  quite  frettb  [xiMenMit  a  digblly  ulkiallue  reaction. 
Ii  apmlily  becomva  add ;  himI  ron'H  milk,  even  wbt'ii  quite  freiih,  i«  Nome- 
tioMv  pli^htlr  und,  tb4>  cbiinice  of  ranvtiou  tukin)(  pliu-e  during  the  ola^ualioD 
%l  Ute  uiilk  ID  the  nuimmary  ducu. 
TlMCODStiluGiil'  of  milk  are: 
1.  lyoieiitt,  tit.,  coado,  and  an  albumin,  agreeing  in  it*  general  fcaiurc* 
with  ortliiiarv  ronim-nlbumiii,  but  nbicb,  >iiii'e  it  i«  raid  to  dilli:r  i>i>(iien'hat 
»  ita  Mlubilitint  nod  rotary  {miter  from  xKruui-alhumiu,  bnx  been  called 
iilrfnfhiiaii'ii  Tbo  cawii),  ni>  ne  have  iioi-ii.  .^  '207,  uiidi-r;(o«^  through  the 
•etiuu  of  reiiiiin  u ebangv  whereby  in*ahiliki  i-umiu  (tyn-iii i  mako  it«  appear- 
snc*  and  tiM'  milk  >•  cunllcd.  OiKin  may,  huwever.  lie  prcoipitutcti  in  an 
ltDobaaKr<]  form  by  ^iiiumting  milk  irith  m^iilntl  faht,  <tr  by  tbc  i-arcful 
wUitiMi  of  acetic  acid  to  ililiitnj  milk,  or  by  lirst  luliliiiji;  to  the  dilui«(l  milk 
S  alight  ((uanlity  of  lu-rlic  ucid  and  then  pnwiii);  through  it  a  strcMD  of 
^wrbraic  neid.     In  the  liltmte  tl>e  prcwnco  of  the  iactulbiimiu,  which  oocun 

tin  Sinftll  Mild  variable  (|uim[iti<«,  may  be  ■luiwn  by  euneulation  with  heat, or 
Lv  pracipitjitiun  with  putaMiuni  fiTmcyanide,  cte.  lo  tlie  nroceai  of  curdliD)^ 
tiw  vawin,  v  stated  in  ^  '207.  a))pear8  lo  b«  not  simpljr  cnan^l  into  tyretn 

Iliut  to  he  Bptit  up  into  lyr^in  and  into  another  nroteiti,  which  unlike  tbe 
lactalbumin  b  nut  couf-ulatcd  by  heat  and  vhicb  u|ipeiu«  Ut  be  allied  lo 
p«|*Uine  or  albumoae.  ThU  or  a  similar  |>epluue-like  body  has  aUo  Ifcen 
JuutHi  in  small  (juantitieii  even  iu  milk  wbicb  has  not  curdled ;  it  hait  l>t<eu 
nlln)  lactopfyjuD.  The  lacutlbumiu,  tbouub  eoaj^uluted  by  beat  when 
iwlntLil.  i.-  not  ao  coi^lated  aa  it  exiAt  in  the  natural  milk,  the  alkalinity 
of  the  milk,  which  u  inereuied  by  builing,  preventtne  thi^  .Similarly 
rueiD,  tbiHieb  eoajiulaled  by  hejil  nbeii  ilmply  aiispended  iu  water  after 
bring  pn-cipilaitil,  i>  out  ooagulUed  by  hcM  wnen  it  exiMa  in  a  natural  cun- 
ditivfi  IU  milk  -.  iu  tlMve  re«pe«U  cnaebi  behavea  like  alkali-albumin,  which  it 
RMinbliy  in  otbtr  fi>atur«  nlwi.  Hcuoe  milk  when  bulled  does  iMt  coagulate 
at  a  whole,  though  in  the  Mi{>o.rltcia]  layeRri  expuHMl  to  the  air  changes  t4ike 
plam  by  which  a  film  or  fkin,  dcrivi-d  chiefly  from  the  albumin  but  jwnly 
bun  tne  cauvin,  nppvnry  uu  ibt;  Nurt'iici.-;  if  tbiM  be  rcmoveil  a  fn-^h  [H)r[ioii 
uadergnea  the  same  chaii)cr.  The  jieculiar  Ixnly  nuclein  which  an  wc-  have 
KQU,  i  'i9,nn  complex  nitri)genou<(  bmly  dilTcring  in  eomjioiitiun  from  pro- 
tei4ls,  is  also  present  in  milk  in  small  ([uiinlitim,  and  aonmling  to  mhou 
sbaervcre  ts  (imply  sm^Rdinl.  nut  mlly  in  solution,  or  it  in  aoinc  way 
peeuliarly  asenciated  with  the  ciuMn. 

2.  J-'ait.  Thcw  arc,  in  the  mniu,  palmitin,  stearin,  and  olein;  bat  otltvr 
&la,  supplied  by  butyric  ami  otlw^r  fnliy  acids  in  combination  with  glycerin, 
accAmpany  the  above  in  small  quantiliva.  In  (his  respect  tbc  tat  of  milk 
reaemblet  that  of  adipose  tiwue.  I.ecitbin  and  cimlnteriii  are  also  prceent 
iu  very  «nuill  quautitv.  as  well  as  a  yellow  culonug  matter.  The  fat  prownl 
iu  milk  differs  in  drUi^rcni  animaU  as  to  the  relative  proportion  of  olcin, 
|»luiitiD.  and  stearin,  and  as  to  the  kinds  and  relative  amount  of  the  other 
Dlier  fai£. 


4)34 


TKE    UKTABOLIC  I'ROCKSBXS  op   Till 


TIm  lutxtiire  (>r  lh«tie  fAt*.  fliiM  nt  onlinnrv  trinpiinilum.  Is  pnanu  m 
tMUiral  mtllc  iii  tltc  form  of  gl<>t>iili!n  of  various  iiijtiv  but  for  tb«  meat  pm 
oxcediii);!)'  tftuutl  (iii  man  frim  2y<<  to  .^m).  Milk  is  in  IVict  a  typical  onul- 
i>ii>ii,  mill  it  t>  lti«  |>TVM.-ucc  iif  th4!  cwtcin  iu  tho  milk  which  briiip  mhoitt  ibt 
«niulHititi.  Some  ()lim-rvi-r>  miiiiitiiin  tliMt  euch  f^obul*  <if  fat  ia  surrotitiM 
by  an  fDVdlitp  or  mi'mtirnnu  uf  Kolid  iin<li«M>lv«()  raaeia  ;  but.  chougb  W- 
<ltiul>liylly  even  wlivii  ilit-  lilt  is  rvniovtil  from  ihe  milk  raoli  Klobulv  nimaiai 
Mirr«tiit<t<.<<l  by  n  lityrr  nf  milk  pIusmK,  if  we  may  to  call  it,  rioti  in  owtn, 
tU»n>  »K-  iio  Mikijuiitv  rMutuns  for  tliinkiiif*  tluit  the  cweiii  uctuolljp  form  ■ 
Rwnibniiii'. 

On  iiMndiiig  ii  gn*l  (]<*l  of  th«  fat  colleota  na  th«  top  of  tho  milk  id  th* 
form  of  creiini,  but  iu  thi«.  (u  in  the  butler  wliicb  ia  furnted  fnim  It,  \ht 
globtilcs  are  ftill  discrete',  eo  lon^  nt  I«a8t  lu  tlie  butter  is  "  fnsh,"  By  ti> 
UK  ttf  a  ireotriftigal  tuaohine  nearly  the  whole  at'  the  &t  may  b«  Mtparaicid 
fh)in  the  plasm*. 

3.  Milk  at^r  or  lactate.  This  is  very  afit  to  un<Iergu  fi!rm<-ntJUton  iutu 
lactic  add,  through  the  o^ooj  of  aa  oiYaiiiMil  femtcot;  thu  niiJk  ibiu 
becooiefi  aour,  and  the  eai^iii  ia  )ireei|iitat»l  iu  a  lloccuk-iit  furm  whcai  thi 
acid  i*  itroduced  in  sulfidenl  ijuautily.  Siuci-  ihii  chaHgi'  will  take  plaife 
vv^ui  when  t-rer^'  tare  is  taken  to  exoliMle  g<-rm>  fri)m  ihit  mtmiHplK-re  bavinf 
aoona  tu  tbi>  milk,  the  nrganiieil  fonnonts  mi.i;>t  bv  pr<'m-Mi  in  the  milk  in  th« 
duct»  of  tlu!  glaiKl. 

4.  -Salu.  ThouK)>  trnoa*  of  umt  and  kreiuiuin  have  bvM  Doted  by  boom 
obmrvpn,  thccxtrnc-iiri'sof  milk.lH-yond  tlK^K-^rithin  iinJ  choloal«riii  already 
mentioDMl,  aro  insignilimit.  Thv  calts  nrv  of  mora  im[Kirtai>cc :  the«e  sic 
obi«fly  calcic  photphnlc,  of  wboM>  function  in  thu  procum  of  cunllitiK  we 
spoke  in  $ 'J07.  and  potuaxic  and  sodic  chlorides,  with  n  small  qunuiityrf 
maKae«ic  phosphate.  Sulphates  appear  to  be  a  been  t.  A  small  <|tntiitity  gf 
an  iron  salt  ia  pmeni.nnd  traces  of  nilphocyanidc  have  been  obsarVMi 
Besidee  the  pho«pbr>niB  in  the  actual  form  of  pliosphalea,  milk  ooBtldliaa 
furtlier  ooindenwlfl  quantity  of  phosphorous  iu  ilie  protetds  and  in  llie 
uuelein,  as  w«ll  aa  aoine  sulphur  in  tJie  former.  The  iDor^anic  ootwtltuanu 
of  milk  mar,  hroadly  speakinf;,  be  said  to  difler  diDtineilr  fnmi  tboM  of 
blood,  and  to  much  more  nearly  reeemble  those  of  tlie  eniin'  body. 

The  ompiMitiou  of  milk  id  tbe  same  animal  varies  widely  nom  time  lu 
tiu>e.  and  Wide«  uiider)|Cieji  marked  ehengcs  during  the  periixl  of  laotali-m. 
Tli<-  retaiivt!  ^neral  compoaitlon  of  human  mitk  and  liiat  of  the  ooit,  tlw 
mure,  and  lh«  biU-h  may  perlinps  be  Nbiiwn  by  ih<!  follnwing  tabic :  but  i*  it 
difficult  l<>  draw  na  average,  Mnoe  the  individual  analvHC^  given  differ  M 
luucb :  the  lifcurvs  givau  for  ducin  and  fat  in  the  milk  of  thv  hitch  may  b« 
unusually  bi^, 

Anrifjfe  Cotupoiition  </  J/i'U'  in  D^ercnt  Atiimai*. 


a'tnui. 

OW. 

Hm*. 

mica. 

Ca»ein.  «tc.. 

4 

4 

S.5 

10 

Fat*. 

2.75 

4 

t 

10 

Guitar, 
StnTts, 

.5 

4.4 

6 

8.8 

i>.23 

0.4 

tl^ 

0,6 

Toul  golide. 

10 

la 

lt> 

i* 

Waur, 

90 

«7 

flO 

78 

The  <|uan(ity  uf  railk  secreted  by  a  woman  in  twenty  hours  at  tho  hi-iglit 
of  lactation  has  been  calculated  at  70ll  to  MM)  cc.  A  good  niiluk  cow  nil) 
f  ii>Id  about  10  litres  of  milk  per  diem. 


t  61ft.   (.Woofnnn.     Thix  i.i  lliv  tiiiiiie  fi'ivm  to  the  milk  »ecrele<l  at  rlx-  ht- 
[inntni;  of  a  [icnoil  of  Inoliilioii,  jij^t  iiefi>rL^  niti)  fur  Mime  i\an  uIUt  |iurtii' 
riiiuo.     Tlin  milk  (litn-n>  Trom  tlii>  ■ul)i«e(iu«il  milk  in  microttGO{Hcal  cbnr- 
•ct^n  Kiwi  in  rbcmti'al  r<iiu{Hi><itiuii. 

WImu  ordinnrj  milk  \*  txtmincd  uiidrr  (hv  roicroM-npv  hiirilly  itnylhing 

i*  M«a  b(«i<Ii-»  ilii-  Tnl  globulM  txcrpl  u  vcrj  Tt-w  im{>rrrri.-t  ci^llii  or  piirliona 

nf  ckII*.  eoDsuting  of  nil  subetniitv  mon-  or  U-m  lomlc-il  nilh  fnt  aiitl  coo- 

-iMttiint!  Hometimce  »  more  or  Km  HlUml  »iicU'Ui>.     A  fi-n  minute  ^niDulM, 

khoii^lit  h_r  some  (u  bo  (wrlicln  of  »ui>pen<lr<)  cBocin  or  nuclcin,  nrv,  however, 

'•Uu  V  IN  hie. 

Colostrum,  od  tie  other  b*nd,  contains  «  Inrgc  number  of  n-lls  or  oor- 
ptiaclv,  nbich  have  been  culled  "eolottrum  cuqntFcled."  Some  of  theae 
eluoelr  memble  leueocyteB,  otbere  are  either  cell*  of  iibout  the  8aoi«  riie, 
ruMnd  or  irteicular,  and  [lOMefcing  a  nucleus,  often  mifsbkncD,  or  are  meretf 
|M>rli>inA  of  cell  aulMinnce  wilboui  a  nucleufi.  In  nil  of  tliem  llie  ctil  aub- 
«Csoc«  mar  !»  loaded  with  fat  j;lobul««  or  amy  be  fairly  )>*e  from  fat.  Sonic 
of  tbnw  colls  a|>|>ear  t'l  Ix-  undergoing  dittinieK^Btion :  »<>m«  niny  at  a  fnror 
Mble  tetiiin'ruiiire  cxliibil  alow  amoeboid  movements,  and  muHt  then  at  lout 
be  KnrdFd  m  living. 

CoTr«tram  uImi  difl<-n>  from  ordinary  milk  in  containing  not  ^nly  a  Inrg* 
qnantiiy  <>f  al)>tinilii  >  tacliilbiiniin),  but  al»u  a  decided  amount  of  globultn. 
In  eott—quewcB  of  tbi*.  coloMtTum  difTcni  from  milk,  inaamueh  a>  it  iadia- 

tXiittUy  eM|nilKt«d  by  bm. 
Aa  >iati.-d  alK'ie,  ilurinjc  tbv  rapid  growth  by  wbi<-li  i1k'  ^'Innd  i«  enlarged 
ttr«mrmt«ry  to  Inrlaiion,  the  alvmli  nrt>  at  Mrnl  Milid  niu.vK^  of  cells  witb 
litue  or  no  lumen,  ami  a  liim«n  is  r«tnlili>>heil  H<il)w^(iifntly  by  the  discbarge 
«f  1^  crnirnl  cells.     It  is  UKially  su|ip(iM'd  thut  llic  ci'lU  to  discharged. 
•DOM   uixlerguin);  much,  o4herB  comiwralively   little,  chaiigv,  supply   the 
«olaeiram   eorpu»cla  just  spoken   ol,  and  at  the  Mime  liniv  funiish  the 
alobulin  and  eieen  of  albumin  also  chanicl eristic  of  colostrum.     But  thia 
m  Dot  certain.    The  alveoli  at  ibis  lime  contain  peculiar  cells  reaeubllog 
faloatrum  curnuadea  except  tbut  ibe^  are  tne  from  fat :  and  it  is  auggeMea 
ihu  tboM  b«ing  diHeIiar>,-cd  uml  taking  up  fat  in  amtsboid  Ikahioii  beoone 
eDlMtmin  corpUKclex.    Sume  regard  the  eoluetmm  curpuaclea  as  aimplj  leu- 

IContM  wbidi  have  similarly  inkeii  up  Ikt. 
f  Slfl.  Tbe  awmmarv  gland  is  pmctil  Ixitb  in  the  female  and  the  mule 
cfaild  at  birth  ;  and  in  bcilfa  lexes  at  iind  fcir  a  ffvr  dnyH  al\er  birth  U  thrown, 
n  roiuraon  with  all  the  olbrr  w-creting  gland*.  iuti>  wcretory  activity,  and  a 
HDall  •(iiaulity  of  milk,  the  "ii:itehn>'  milk."  ao  culled  by  the  Oeiinang,  is 
■lisdiargeil  from  iho  nipple.  The  milk  rc«cmlde»  in  nil  cafcntinl  f^Uim 
tlie  milk  of  lactation.  In  both  wxco  this  initial  activity  soon  pniMS  off, 
the  xlanil  in  the  female  fonher  developing  at  puberty,  but  in  th«  mate 
remaining,  save  in  exceptional  eases,  in  its  infantile  condition  or  somewhat 
r«lrm[n»linu;. 

i  in.  The  tirreiiim  »/  ntitk.  From  nhut  bns  been  already  said,  it  b 
obrfous  that  Ibe  secretion  of  milk,  while  rewmbling  the  secretion  of  tlie 
other  accreiiiig  glandH  uhich  we  hare  studied  in  liein^  eseenltally  an  activity 
of  the  cfNtbeliitm  cfIU  lining  Ibe  alveoli,  neve  rib  el  iim  pn««nu  ivrtun  in- 
lereMing  foatun-n  ijio-bl  to  it^olf.  If  the  account  giwn  in  ^  >31]  be  a  true 
<•».  miirpbolugieal  changts  in  th<'  cells  are  more  pmniiDetil  ihaii  in  the  caM 
of  uthrr  L'tandv;  and  wl-  may  iiilt-rpret  the  npjtearani-eH  there  related  aoni^ 
what  nx  I'lltown  :  \Vbe<>  tlw  <Ii>chnrged  giaud  with  it^  low  epithelium  begioa 
Uir  Work  of  lundin^,  the  celt*  dixtiiiclly  "  gntw."  Their  cell  tubstance  in- 
iHiawt  in  bulk,  awf  elongaliug  timjceti  int"  the  lumen  of  tbe  alveolun.  At 
r  tlu  «aif  lime  tbe  nucleus  divi<K-«  aa  if  ihv  ctll  neru  about  to  give  birth  tit 

40 


TnB    J1£TA»0LIC   rROCBSSBS  Of   THIE    801777 


new  oelh:  but  at  Am,  M  nil  «veniH.  Ud  itivisiun  of  Uie  wll  Hubauuice 
place,  mid  the  uen  nuclei  lie  JinWiiOtMl  in  a  cooiiihmi  cell  Ixxly.  ' 
subaUnoe  inevnwliilt?  (lutit  ua  ftecnuorv  aclivitv  ;  it  (}i:|HRiiu  ju  ilix-if  lualeriil 
to  form  milk.  Tbi*  ilvjKxiit  of  Tut  ia  cuiiKpicuouii  atkl  ctmily  n^oftniiiil,  liui 
wi-  may  furly  iufcr  tlinl  llw  (itbcr  I«m  voaily  ilixtiiiguiNhed  jiroLoiil  und  (uiil>>- 
bvdnU«  mntc^rinl:)  are  dujuvitei)  id  ihi;  c*Al  vulwuuive  in  a  niniiliir  lisuibina, 
"ftiftn  fulloii's  the  (--jiflimi  of  llw  prvpiirvd  material,  and  tliix  ninT  tmko  pUo 
in  ono  of  two  way*.  11m-  oil  f{Iobult«  of  lat  may  l>c  proirudis)  tmni  tbv  crW 
eubataiioo  mucli  iu  the  miiik'  way  tluit  an  anuvba  fxttudw  it»  i-xi-rotntnl,  as.! 

E«ribl;^  otlwr  c-oii>titiio»i«  nf  milk  may  tic  i'j<-<-t(->l  by  ii  utmilar  metbod. 
lit,  bttidea  thu.  tbo  dHrrrwl  oiiU  divtaioii  now  tukta  iitniij  in  a  eomewhat 
imperfect  fnsliioD,  m  that  jwrlioiia  of  ibi-  >M  ovll  ciirr>-iti^  nuclei  nilb  ihtn 
come  aaiinder  from  tlic  reet  of  tbo  cell  in  wbirh  a  nurlvux  ta  lell.  and  In 
loose  in  the  lumen  of  the  alveolus ;  jwriions  of  oolt  su)>»taDoe  free  Gram 
uuolei  appear  also  to  b«  ciMt  oA'.  Here,  in  the  lumen  of  ilie  «lve<iliu,  they 
rapidly  under)^  chan^ ;  tbe  cell  aubetance  is  allerod  ami  ilissulvexl.  awl  iU 
load  of  prepared  material,  probably  UD^IeiKoiD);  in  lite  nci  some  ftinher 
chaiwe,  is  mt  free,  the  nuclei  aleo  undergoin);  cliaof^  and  t>ei.-iim(nK  ulli- 
mnuJT  broken  up.  Hence  the  oonsit(uent«  of  milk  are  provide^l  for,  »>! 
only  an  in  o4her  i;landd  by  tlie  inalenal  wiib  ulii«li  the  cell  loaiU  ib«lf  Had 
MiljWHiuejitly  diaohargea  into  tbe  lumeu  of  tl>e  alveolua.  but  hImi  by  the 
actunl  ■ultntance  of  part  of  the  cell  ilaelt  The  i.-liaracteriatjc  nuclniD  of  tb>- 
milk  biw  ibn*  it*  onjiin  in  all  pFobability  in  the  uliwl  nuolei  of  th«  iccreuag 
oalla,  and  we  may  {>erlva|u  iufir  that  tbe  mill  more  characteriMic  caatlll 
exiat'  ill  milk  in  Inu  form  of  <-n.ii-iii  and  ni>t  uf  iconic  other  pruteid  III  iniiM 

aueDC«  of  thii'  inliirvealioii  uf  lh«  mrUml  cell  Muliataiioe  in  the  fonnhtiao  of 
to  milk. 
It  ia  hardly  iHrrt-Kuiry  to  add  thai  ihn*  bodily  coniribulionauf  ibaMuratlng 
cell  Ui  the  H-cn-lioii  nrv  iiiHXimiiatiii'd  by  that  mora  nnliiiary  |iai1  of  wi^rflioa 
whi«'h  fiiniiii't«  in  lli>-  How  o)  lluid  mnluining  various  matlvn  in  Milutioa 
Ihrotigh  Iht  celle  inu>  the  alveoli,  iba  general  oompoailloB  of  tbe  milk  being 
thus  secnrml. 

I;  A18.  TheM-crotion  of  milk  ilion  would  npiivar  to  illitxirat^-,  even  tnori 
fully  and  dearly  than  do  other  glands,  ibc  tnith  on  nhich  wv  hnvt-  ao  oftca 
iu^ted,  that  n  secretion  is  eminonily  the  n»iilt  of  th«  mxliitiolic  actiritj  of 
the  aeotMuig  cell.  The  blood  is  the  ullimiilc  souroo  of  milk,  hut  it  beoonec 
milk  oulv  IhrouKh  the  activily  of  ihe  ct-ll,  and  that  activity  oonsista  lar^y 
in  an>eta*bo1ic  manufacture  by  the  cell,  and  in  the  cell,  of  the  comrouu  thiajp 
hr(iu)chl  by  the  blood  into  the  epeciat  things  present  in  the  milk.  Kxperi- 
meuud  rttfultK  tell  the  same  tale.  Thua  ihe  (|UimtUy  of  fal  present  in  milk 
in  largely  and  directly  increased  by  proietil,  hut  not  increased — on  the  co«- 
trar%-  dimiut^ied— by  fotty  food.  This  effect  on  the  mammary  f;lnnd  ia 
particular  is  in  aooordance  with  what  we  shall  preKntly  learu  to  be  tlic 
geiK^nil  elfi^ct  on  the  body  of  proleid  in  conlrast  to  that  of  fatty  food: 
protei<l  fixHl  kociuh  to  iurivaM  the  eeueral  metabolic  activily  of  the  IkmIv. 
white  fatty  foiwl  leiida  to  leMCti  iL  Momiver  the  pniteid  food  bcouh  m-tiially 
W  funiinh  (he  fal ;  aiid  we  liavr  ulrondy  >u {[)<•'' l*i I  a  maimer  iu  u  liich  )>ni- 
beids  may  pve  riae  to  fal.  Tliul  tltv  lat  of  tint  milk  nred  not  ni-i'ew«rilT 
oonw  from  ibe  fat  of  the  food  ii>  rliown  by  the  follouinj;  (.-xin-rimeut ;  A  bitcn 
fed  on  mimt  for  a  giv^Ji  periixl  gave  off  morr  fal  in  \»:t  milk  than  she  oouM 
ixwaihly  have  taken  in  livr  f<H)d  ;  and  thl*  mon'over  tiuik  place  white  abo  WU 
gainini;  in  wei)|:hl  and  "  Inyine  on  fnt,"  »»  tlml  ^hr  ooiild  nut  have  supplied 
the  mammarv  gland  with  liit  by  i<imj>ly  tniiwlcrrin^  tiit  from  (he  ttore  pre- 
viousty  exiftling  in  ihv  iidi[i<i»e  timu«  of  her  bmly ;  sbo  nppun-iil  ty  oblainei 
ihe  bt  ultimalclj'  Ihim  tlic  proteids  of  her  food.     Aim)  the  hiiiologicul 


ahovf  favor  rliv  virw  lliitl  the  lorRintioii  ff  lilt  out  oP  prot^il*  iti  »ilu1l 
tmkm  fAnei  in  llif  tx\U  of  llio  iilvmli.  Thi-  PXiioriniAnial  l)ii:ai  m  noil 
«u  thr  hi>iiil<tt.'WI  vvtilviic*  gom  to  riww  Uiul  till-  fnl  nf  milk  i»  r»niK-<l  in  ttifl 
<.'<-l1  Biiil  l>_r  tltu  (vll,  mill  i«  Doi  timplj  gathorol  out  of  tlio  blood. 

Th«  cuvin  ill  n  similar  way  8nn»  to  tw  fnrmvd  l)y  thi?  action  of  Hif  calL 

It  cannut  b<-  gxiht-ml  oiu  of  Ibc  blood,  eioce  the  blood  cootsins  no  n») 

~n:  it  iniut  be  funiica)  in  the  gUnd.     Soma  observeri<  hsvc  tnaiitlnined 

•hat  when  milk  is  k«|>i  nt  '-i't".  ihc  ctwtn  is  incrcmod  through  some  ferment 

»(Xti>«  taking  pliu.-e  in  the  milk  itielf :  txit  this  sceius  not  to  b^  the  ciuc,  and 

tt>c  furmalioD  <y(  Msein  miisl  he  regarded  nt  the  neult  of  the  action  of  the 

cell.     £vm   the  albumin   present  nppenrs  to  he  uot  ihe  ordiiinrr  ■enim- 

mlbumio  siniplj  paMed  fraoi  the  hl'iud  ihroitgh  the  cell  into  ihe  tumeo  of 

th*  atvetdus,  bol  the  stightlj  different  lactalhuiuin.     We  may  iwrbups  re^rard 

the  albumin  u  leas  difficult  to  mHnufnctiire  than  the  ciMein :  and  we  may 

vxplain  ibe  laoi  that  relatively  to  the  albumiu  the  i-aaein  is  le^  at  the  very 

berinuinK  anil  otpecinlly  towanl  the  «Dd  of  lactation,  hy  supiKiaiiiir  that  the 

ttU  hat  iu  [Ik  lint  cane  not  g^t  into  full  ir»rkiu);  onler,  and  iu  UMMoond 

cMa  a  waniuK  iii  fin-vr.     The  peptono  like  body  in  milk,  though  «mall  in 

aunniity,  is  a  furtlH-r  indieati^m  of  the  pruteid  metabolium  tukin);  pluoe  in 

inr  ffll. 

lliat  the  niilk-KiiKiir,  liu-litw,  aUo  in  formt!*!  in  and  bv  the  cell,  is  indicated 
fay  llw  facia  that  it  i»  fiiund  in  mi  other  ii^rt  i>f  the  Wly,  ami  tha!  il.i  prua- 
ncw  in  milk  is  nut  dept'ndvni  on  (■■irbniiyilnilv  foml.  fur  it  in  nuiintaini^l  in 
ahundanoe  in  tb*  milk  »f  nirnivuni  nhi-ji  ih<w  are  fed  excluitivoly  on  m«M. 
M  froa  m  poaiibl*  fmm  any  kind  "f  iiugtir  or  glyco)£«n.  A  glvcogtn-llko 
boily  ha#  iiKircovvr  lir^'it  dencrilx-d  iw  existing  in  the  cells,  and  it  lii  auggMtod 
that  this  UhIv  i*  lli«  antccodcDt  of  Ihe  Inctow. 

We  thuD  havo  evidenco  in  the  mnmnuiry  gland  of  the  Ibrmation,  by  tho 
uetsbiilic  activity  of  tho  wcrcling  eell,  of  the  repruentatives  of  the  three 
jtmt  cluMS  of  food'ttul&i.  urotcids,  fata,  and  carbiihydratn.  It  is,  of  course, 
■{uite  tnie  that  all  Uie  cell  Itua  lo  do  may  he  simply  to  turn  aside  into  the 
•pccial  cAiteiu,  (hit.  and  lactooe  the  seneral  sumily  of  proteids.  fau.  and 
(iu^>»hy>l rates  brought  to  it  in  the  blood,  without  these  over  het-oming 
actually  part  of  the  cell,  the  formation  of  Ikt  nut  of  pr»Ieid  «[>>'>keu  of 
above  takins  place  in  •ome  other  part  of  the  bcxly.  Still  it  b  ojien  for  us 
tanippoae  that  iliey  ate  all  three  formed  in  the  cull  iiaelf  out  of  the  com- 
pralmwlTc  living  cell  9iilutim<-c.  [f  ne  accept  tbr  lutlcr  view,  we  may  look 
apoa  what  is  taking  pliux?  in  the  timmninry  cell  iw  n  pictuni:  of  what  U 
roiiig  on  in  vnr><Hi>  living  liiuucs.  If  the  fut  of  the  milk  wore  not  ejected 
from  the  maiiimiiry  celt,  the  mammiiry  gland  woiilil  become  n  iniua  of 
•dipoae  tiaine,  <»|>in-iiilly  if,  hy  n  sliiihl  change  iu  iho  metalioli»m.  the  pro* 
duction  of  jal  wen-  exaltnt  at  ihu  exiiensi'  of  the  production  of  casein  or 
nilk-sugnr.  If,  again,  by  a  similar  flight  change  th<i  milk-ntgnr  wei« 
accumulated  mther  llinn  the  tut  or  protcid,  «e  should  hnvc  a  n-jtiit  which, 
hy  an  easy  step,  woiil^l  bring  ti«  lo  glycag«nie  tiflHic.     And,  lanlly,  if  the 

Eroteid  aecumulntion  irore  great«r  than  the  fntty.  or  the  aaocharino.  Ih«l* 
eing  carried  off  in  some  way  or  other,  we  should  have  an  image  of  the 
natrilion  of  meh  n  tiaue  aa  muwle,  in  which  tbo  protaid  constituent  >•  in 
«xceeB  of  the  other*. 

(  516.  That  both  the  secretion  and  ejection  of  milk  are  under  the  control 
of  the  nervouA  systetu  is  shown  by  common  experience,  hut  the  exact 
nvrvm*  mechanism  bu  not  yet  been  fully  worked  out.  While  the  erection  of 
Che  ni|)p1e  oeoaea  when  the  emnal  nervod  which  supply  the  hnsiiti  aro  dividiil, 
Ctic  M-cn-iiou  euntinuuB.  and  is  not  arrested  even  when  the  lympattieticaa 
^lell  lu  the  spinal  nerve*  are  cut. 


CHAPTEK  T. 


XUTRiriON. 


TllK  STATWTltM  OK  NwilITIOK. 


^£30.  The  preceding  chapter  bos  ilionn  at  how  wholly  [mpOMtUe  i^Ki 
at  preeenC  lu  muster  the  metabolic  [)heooiuena  of  Ilie  body,  br  atleiuptiii^-  to 
trace  iiut  fcirwnrd  or  backward,  the  several  chaiigea  uiiderfpine  bir  the  in^ 
vidual  louBliluenl*  of  the  Ibod.  the  bmly.  or  the  waste  prcxlucla.     Anothrr 
nx-thml  h.  however,  open  to  us,  the  itatUticoI  Diethud.     W«  may  ttvtrtmis 
th«  t»tal   income  and   the  total  expeoditure  of  the  body  duriug  a  gimii 
iH-rivd,  and  by  conipariu^  the  two  luaj'  be  ublu  to  draw  co»cliuion»  cnnccni'^ , 
ing  t.h«  chaoges  which  muni  have  taken  iilac«  in  the  biidy  while  the  inconiej 
wnM  being  converted  into  the  output.    Many  newarchi-s'  have  bn-n  cariMl 
out  by  thin  methoil ;  but  valuable  uii  are  llie  rntultjt  nhioh  hnvo  tH'Cti  thertby 
gained,  thrr  must  Im^  received  with  caution,  juuce  in  thiit  metb'x)  ut'  inijtiirj^ 
asmall  ■.'^rnir  in  the  dalH  may,  in  tbr  [injcettn  of  calculation  and   inferetieC)! 
lend  to  mtwt  wrong  ciinclu»ii)uii.     The  grc«t  udc  of  nuch  iniiuirie»  is  to  eaf 
geat  tdcii*.  but  the  vicw!"  to  which  thtty  give  riw  iieetl  to  be  verified  in  other 
ways  bcftin-  they  can  iicciuin-  real  wfirth. 

Vompogilion  of  lh(  milmnl  bodii.  The  first  datum  we  rMjuire  ii  a  knowl* 
edge  of  the  cwmpoeition  of  (he  body,  a*  far  as  the  relative  proportion  of  tbv 
TKiious  tissues  is  concerned,  lu  the  human  bodv  the  pni|Hirtioiis  hr  weight 
of  Ihe  chief  tiwues,  in  the  fresh  state,  are  probably  somewhat  aa  follows: 

A4ull  nuui.  Nsaham  lalqr, 

fernni.  l-MnuL 

Skeleton 15.9  17.7 

MtisclN 4].«  U.9 

Thoracic  vincera ].'  S.0 

Abdoroinul  vueera 7.2  11,0 

F-l 1«.S)  «,„ 

Llrsin ].$  IS.S 

Ao  toaly^  of  a  cat  ba*  given  the  folkming  nwult; 

Muiwlm  and  tendons 46.0 

BonCT H.7 

SkiD 12.0 

Mesentery  and  adi|>o»e  tiun« S.8 

Livtr -LS 

Dtoud  (racitpinji  M  Omlh)       .......  ftiO 

Other  (irgani  and  iiHiues I8.T 

One  point  of  importance  to  he  ui>tice<l  in  these  annlrMS  is  that  the  skeletal 
muaeles  form  nearly  half  the  body  ;  we  hiivc  alrradr  seen  ■  $  38)  llinl  aUoal 
a  ijuarter  of  the  total   blood  in  thv  budy  is  conUined  in  tlwn.  and  h*r« 


yiTKlTION'. 

^■mSnaif  ft  4&S)  imiHlod  that  «  Inr^  part  of  tlie  itivlubulutm  of  llio  hutly  !• 
outin  on  ill  th«  muiicln.  Nosl  t«>  iW  mmtclfu'  we  niunt  plnt-i;  lli«  liver,  for 
tbuuf;h  Ikr  Imv  in  IhiIIe  (liaii  ih<<i|i,  il  is  Rubjrct  to  n  vi^y  nctivi-  mctiiiwl- 
iin :  ifaifi  i*  minnitvd  tiv  the  l«cl  ttiHl  il  Htonr  may  bold  about  a  (jiiartirr  of 
tW  Kb<ilc  bliHidTand  n  also  indioMcd  br  tho  Dum«rou»  fncU  brought  IwfoN 
o»  in  tlK-  prvcwling  chontcr. 

$d31.  Tlir  tlarrinrj  My.  Bt-fon;  altempting  to  stiidv  the  inHiicncr  of 
Ibud,  it  will  1m-  tiKlui  to  AfCi^rtkin  whnt  changes  occur  in  ihd  h'xly  when  nil 
fnal  if  withheld.  A  <-nt  of  known  w«if;ht  wu  starvfyi  for  ihirtci-n  ilitTx. 
Al  the  bf^nning  of  iho  period  the  body  was  prcsnincd  to  have  the  eonipoM- 
lioa  ^ven  above;  nt  the  close  uf  the  ]>erio<)  a  direct  noalysis  of  the  body 
WW  niaile.  From  thin  it  aiipeAred  that  durinj(  the  huni^er  period  the  cat 
kail  I'let  7-1-I  f;ranii)ieH  of  «o[id  nialertal.of  which  246.8  were  fat  and  l\>i.'i 
auacJe,  the  retnaioder  bcini;  derived  fnxn  the  other  tuau«s.  The  [lerceut- 
•gn  of  dry  Mtlid  matter  liwt  by  ihv  inure  imporlaut  tinu«H  dnriiig  the  period 
««n  aa  follun'* : 

AiliiHiM  titaue 9TJSt 

UdIvm «S.l 

Lirer &t|j6 

MmmU* 90.2 

ilhwd lT.a 

ilrvin  atui  njnMl  mrd 0.0 

Thu»  tite  l<Mu  (luring'  slnrvntioo  fell  muHi  heavily  on  tho  fat.  indeed  DMri.V 

the  wholf  iif  thifi  diaajifx'nred.     Nnst  to  the  fivt,  (he  glandular  organs,  the 

tiaauea  Hbioh  we  have  «(wa  to  be  eminently  metabolic,  suffered  m<ial.     Then 

eurae  lb«  niUKlM,  that  ia  to  aav.  the  ekeh^ul  ninacltt.  for  the  linu  in  the 

heart  wa*  very  trilling ;  ohviouily  lhi:<  orgnii,  on  Recount  of  it»  iniportjiDoe     . 

in  carrring  on  ihv  work  of  the  economy,  hub  spared  m  much  lu  powible :  It    I 

^WAft  in  fact  fed  on  the  mt  of  the  body.     The  «ame  remark  nnpliea  to  the     * 

br«in  ami  spinal  cord  :  in  order  thai  life  micht  be  pralonroa  as  ranch  as 

possible,  theee  imprirtanl  orLtmH  were  nouriahefl  by  material  drawn  from  Ims 

noble  orfputf  and  ttMues.     TIil-  blood  aiifibred  proportionally  lo  tho  gonoml 

IxMly-wasle,  becoming  gradusllv  lew  in  bulk  but  retaining  the  same  ipccilie 

Hmviiy ;  of  the  toul  dry  prmeid  eiiulituenu  of  the  body  17. •!  Jicr  cent,  ww 

loM.  which  agreea  very  fli»elv  with  the  !7.6  ner  cent,  dry  lUHterial  (almoM 

■wbolly  proteiil)  lust  by  the  bliXKl.     It  in  ivorliiy  of  remark  lluit  the  tissua 

in  geoenil  l>ei.-iuue  more  uaiery  than  iu  health.    Similar  obaerrationa  on 

otb«r  aniiuii]  have  led  to  similar  reMihii,  the  chief  dJ^oonlaDoe  being  that  in 

•OOM  cumb  the  bouce  have  iuiremi  conaiderable  Iim.  in  oiliera  comparatively 

Uttlct.    We  might  be  ineliiKn)  to  inlhr  from  tbv»  <liiiii  the  ouncliiaioiiB  tfaM 

nieta  Ik  ilium    in  mmit  ni-tivo   in  the  iidi{Kitc  limur,  next  in  *uch  nietaliolio 

tMHic*  a«  the  hepatic  celU  and  (]>lecD-pulp,  then  in  the  mufclcs.  And  to  on; 

but  we  hare  no  warrant  for  ihnv  conclufrion».     BecaiuH-  (lie  ln«  of  cardiae 

and  nervmis  tistue  wa>  »o  «iniill,  we  niiiRt  no4.  therefore,  infer  that  their 

BCialHdi^m  wm  feeble;  they  may  have  undergone  mpid  tnciabolisin,  and 

yet  have  been  preaervod  from  lue»  of  lubstanee  bv  their  drawing  U]xm  other 

tiwica  for  their  material.    Tlw  grml  lorn  of  adij»wc  tissue  is  obvimi^ly  to 

be  explaii»ed  by  lite  fad  that  that  tinac  laceBenlitillr  a  storchoUH  of  mate> 

ml.  and  the  eimilarly  ^n^ui  though  Icaa  loM  in  the  spleen  and  liver  indi- 

caiea,  u  indeed  the  facts  recor<^  in  the  previoas  chapter  suggoat,  that 

ihaw  organs  too  serve  in  part  a^  storehouses. 

Daring  tbu  starvation  period,  the  urine  contained  in  the  form  of  urea 
(and  that  practically  represents  nil  the  uitrogeu  of  the  urine)  27.7  granimea 


i 


XCTBITIOS. 

of  Dhrufiti).  Now  ibc  ninnuiit  of  mii»cle  nhich  wan  Iwt  diiriii^  llii:  {xtriixl  cun- 
tuinctl  lUMHil  1>>.'2  »f  (litro^i.  Thii*.  more  lliaii  linlf  Ui<'  nitroifi-ii  of  ihr 
output  during  the  nUirvatioti  |>rrio(l  imii^t  h«v«  v<>iiic  ullimalrly  rn>m  tbo 
Riclftbolism  Df  niUHuUr  linui-.  This  furt  ire  haw  nlri-nHy  fiHsi  in  tliMur- 
eiiii;  ihr  hietury  of  uren  and  bIihII  have  occn»)on  to  Rinki;  Tiirtbtr  u»  of  il 
horeafier.  Tbt<  amMiiit  uf  urm  excreted  |>er  dieoi  1>r«  l>een  ulwervnl  in 
some  cfls«8  to  fall  verv  rapidlv  duriii|i  the  firet  dwj  or  tvo  of  BinrVAliiiii.  ami 
tlicn  lo  diraiDiBb  gradually,  tfioup;!)  ufleti  ehowiiiK  w>Qsidierable  irreitulantlis. 
Ill  i>ih«r  cases  Da  such  lar^  initial  fall  haslieea  obeerred.  Ii  is  ruiwt 
marked  in  aDuiiala  which  have  b^a  well  fed  beforo  Ibe  liej^inoiiiK  of  ibc 
UarTatiou,  eepecially  in  tboae  vrhicJi  bav«  had  a  ricli  nilro^Doui  diet ;  and 
llw  diseharife  in  ihese  caaea  of  an  extra  quantity  of  urea  iu  tlie  Orxi  day  or 
two  is  dhviounly  conoected  witli  that  iiuii)ediat«  eiR>it  of  TimmI  on  the  exi-re- 
liiiu  of  iirra  to  ubicb  uc  bav«  alr«iuly  (M^^^  reftrrvd  and  (n  wliii-b  we 
skitll  have  to  returii  id  8]>«itking  uf  wbal  u  known  ww  "  luxu»-tii>uituni|)tiou." 


OmparUon  of  Intomt  and  Output  of  .ValfriaL 

i  582.  SlHhod.  We  have  i>ow  to  inquire  how  tlw  eleiuenta  of  fixHl  an 
dial  rib  II  led  in  the  excreta,  in  order  thai,  fmiu  the  manner  of  tlie  dbtrihu- 
tion,  w(^  may  infer  llie  nature  of  the  interinediat«  aiaget  which  lake  place 
within  ibe  body.  By  comparing  Ibe  in^eslu  with  lh«  excreta,  w«  iball  learn 
what  elrmcnlH  lia\'e  been  retained  in  the  body,  and  what  elemenU  a|>|H-ar  in 
the  <'Xcri.-tii  which  were  not  [>resent  iu  the  foixl:  from  these  vn  inny  infFr 
tliv  cbuDgra  mliich  the  IkhIv  hai  umlergime  ihrougti  tin'  inlluencv  of  ibn  Tikm). 

In  th«  finti  phict',  the  real  inooiiti^  mii»t  Ik  rliilint.'ui'tici]  from  llic  npimrvnt 
ont  by  the  ttuntinctioti  of  the  feci'!>.  Wo  lutvi-  rHVu  tliiit  by  liir  ibe  Kri'-alvr 
part  of  the  fccw  i;"  undigoHi-il  inHltcr.  i.  r..  food  which.  tbouKh  |>'"cird  in  the 
alimeiilnry  caiinl.  ban  not  rcnllv  entprrxl  into  ihe  l>ody.  The  >>lian<  in  till 
fet^'i'g  lalicn  uji  bv  nmltr-r  nbich  Imit  been  cxcrelci)  frvm  the  lilootl  tolo  llit 
alimenlnry  cannf.  i»  *i>  xniull  tlwt  it  may  be  neglected :  cwrlainly,  with  r«van) 
to  uitroi;cn,  the  whole  <iuantitr  of  this  ekmonl  which  is  jireecut  in  (be  fvcw 
may  be  rcf^jxled  n»  indimiing  dimply  ondigeeted  nilrogenou*  matter. 

The  income,  thus  oorrcclol,  will  <wii«isl  of  so  much  nitrnf^n,  carUin. 
hydrogen,  oxygen,  sulphur.  pb<«pbonis,  saline  mailers,  and  water,  contained 
iu  the  proteids.  fata,  carbohydratee,  snlto,  and  water  uf  the  food,  tovetber  with 
ihc  oxv^trn  absorbed  by  Ui«  lun^,  skin,  and  nlimenlary  canal.  Tlie  output 
may  be  rejnirded  as  consiHtin};  of  \  I )  the  reBfuratory  pnxlucU  of  the  luup, 
•kill,  nud  alimentary-  canal,  conniAtint;  chiefly  of  earl>onic  acid  and  wiu«r, 
H'itli  xmall  iiUBUtiiiee  of  hydro}^u  and  carburetled  bydn^een,  these  Iwu  liUlcff 
coming  rxi-luiiively  fntin  ibe  alimentary  canaJ :  (2)  of  perepirHtion,  coilliil- 
{ui;  cbirtlv  (if  water  and  ealid,  for  the  ilubioua  excretion  (!«e  s  4;iU)  of  una 
by  the  »kni  may  Iw  neglected,  and  the  otiter  or):ani«  conntituenta  of  s««al 
untount  to  very  lillle;  and  (3)  uf  the  urine,  nbicb  in  il-wuiihiI  io  contain  all 
the  nitrogen  really  excreted  by  live  ImkIj-,  biwid^  a  lur^o  ijuaniitj  of  utlino 
matter*  and  of  nnter.  Where  great  lu-i-urauy  i'  rei]uire<l.  iJm;  total  nitiD^cB 
of  ihe  uriiK'  oiifjbt  to  lie  determined;  il  t«  maintaiiH^,  however,  ihnt  no 
error?  of  wri^tnn  tmjiortaiico  ariw  wlieu  the  nrvu  nione,  aa  deiamtined  br 
Ltebig'n  nielbod  i  ubicb  was  largely  ui>ed  in  the  ri-»eiircbr«  fitnaing  the  haeu 
of  ibe  premnt  dikcumion),  in  taken  as  tiw  inewuni  uf  tl»  UAal  otuuititr  of 
nitrogen  in  the  urine,  sinc<\  in  ibio  nM-tbod,  <itbur  nitnigeiwiia  bodica  lieeidw 
urea  are  |>recipilal«<l,  and  m>  contribute  lu  ibonuanlitalive  rntull.  It  hna 
been,  and  indeed  Mill  is,  dcWted  whitbcr  the  body  may  not  suffer  loaii  uf 
nitrogen  by  other  cbaniK-ls  tbnn  br  tbo  urino  and  fec««,  wheiber  uitrttgm 
may  not  leave  Ihe  Ixidy  by  iho  skni,  or,  indeed,  in  a  gaseous  aUle.  by  the 


Iinliini-r  »i'  ihn  coiiflioting  cvid<-itr«  weni*,  however,  in  t»\X 
__  Tim  tbat  no  «uch  Iota  inkn  iilncc.  It  would  n|)ucnrlhBt  though  oitrogen, 
xhr  |iivul,  M  i(>  f]trak.  of  tlic  i'fi<^mi(al  cluitigM  nf  living  l>riiigs.  fvrniH  ao 
I«rgi?  K  porlioD  of  lh«  a(mtie|>hcri-.  iimJ.  moivovFr,  is  phvKiciilly  iltHiiMKl 
vbrouf>h  ihr  boilin  of  bnlh  |i|nnl«  nni.1  iinimiiU.  tVre  nilri)^en  n  ul' tiiichiimcal 
to  diher  uf  thvat.     It  enters  inM  iind  rcninins  In  ihcir  bodicv  us  nn  invrt 


I 


*ul>'tiinre.  niii)  the  ninn);en  iihich  lenves  a  piiiiil  or  animal,  in  a  gmraua 
»liitir,  is  «iiu]tl_r  a  part  ol'  the  fame  inert  supply,  and  does  not  cone  m>ni  the 
tirrakitig  up  of  ibe  nitrogenous  etlbalnrifee  of  the  borly  or  of  tbe  food. 

Of  ili««e  eleDieols  of  the  ineoiue  and  output,  the  niirogea,  the  carbon,  and 
Ihe  fre*  oxj'gen  of  respiration  are  by  far  ibe  most  iinjioriant.  Sioce  water  M 
of  UM  to  (be  hotlv  for  merely  mechanical  piirpoaes.  and  not  solely  as  food  id 
the  Mriet  aenae  of  tltc  word,  tbe  hydrogen  etenieul  t>eciiniett  a  dubious  on« ; 
th«  tuipbtir  of  the  tir^eids  aud  the  phoitphorus  of  tlie  fnt^  are  inH^iitieiint 
In  amount  ;  wbih-  llie  aijine  nintten  stand  on  a  wholly  dilli-rent  fiKiling  from 
tlMolbvr  Mrt*  of  food,  ioaainuch  iu>  tbey  are  nut  wournv  of  i.'ncrgy,  nod  pfMS 
ibrougti  to*  body  with  conipaniiivcly  liitle  ■•liaiigv.  The  biidy-weight  must, 
of  CoarM.  b«  oreTully  a*ctTlain<^l  »t  thf  bi'ginning  and  at  tbe  end  of  Uie 
pftiod.  corrrctinii  being  made  wh«rv  jiowilile  lor  tbe  fctN«. 

Il  will  bi'  frttt  tbat  the  laborof  auch  in(|uirioi  it  eoDnid^'nililc.  The  urine, 
which  tiiu^t  bf  rnn-fully  kept  a^Hrale  from  the  feces,  rciiiiim  dnily  mc«>itny 
iD0lt  and  nnnlyiiK.  Any  loi»  hy  tbe  »kin.  either  in  tbt;  form  of  xwMt,  or,  in 
ibt  rwc  of  Brmltv  nnininU,  of  Imir,  miivt  lie  r«timateil  or  nccouiiled  for.  TIkC 
food  of  tbe  perrtjal  mtiM  Ih-,  ni>  fur  m*  poiBihte,  iinilbmi  in  cbaracler.  in  order 
that  the  analyws  of  »|N-eiiueiii>  tnuy  serve  faithfully  fur  calculation*  involv- 
ing the  whole  luantity  i>f  foiMl  tnlcen ;  and  tbio  is  <-8pccially  the  en»e  wh«n 
~:ie  <liet  n  a  meat  one.  ciiice  tiorlions  pl'monl  dilfcr  tiy  much  from  each  other, 
lut  tb«gren(eBt  difficrilty  ol  nil  li«;  in  the  estimation  of  tbe  cvhnnic  a<-id 
rudueeir  and  the  oxygen  coiisiinned.  In  some  of  the  earlier  rewarches  this 
or  waa  negleeie^l.  and  the  variationi  ocourting  were  simply  gueweil  at, 
titrough  which  veri-  serious  erron  wvrv  intrudueeil.  Nu  comparison  of 
iaconnc  and  output  can  be  eunsidered  saiinllnetury  unless  at  least  the  carbonic 
add  jinxlured  be  directly  measured  hv  menn.i  of  a  mpiration  chamber. 
And  in  onli-r  that  the  cunipiirison  fhoulii  be  really  complete,  tbe  water  giwa 
off  by  (hi-  xkin  and  tiiiiK»  mtiKl  he  dirt-ctly  meftsured  also:  hut  lliia  aeenis  to 
bo  an-Tv  dillicull  than  the  diterminatioa  of  the  enrbooic  ucid. 

'  la  the  plan  originally  adopted  by  Kegnnult  and  Keivel.  and  followed  by  some 
Mbrr  oHwrrrm,  (he  aniiniil  cximiinenieil  ou  !■  allowed  to  lireatbe  n  Unii(r<l  and 
mesaurtd  hi  mod  j<  here.  Tlie  carbuuic  acid,  as  faat  as  It  In  luraied,  in  lived  ami 
(tnoved  by  ■  i-lt'iD)C  Hilution  of  caiulie  potash,  and  the  normal  percentage  of 
uygeu  in  the  a(Eii(niphi're  i*  mainlninrd  by  a  suptilyof  thtvssH  from  ■  gas-liulder, 
la  ibi*  way  both  Ihr  myKcn  cooauroed  and  the  carbonic  acttl  ptoduied  arc 
Mrtrthi  detrrmined.  uhilc  the  coBtlnual  snpply  of  freob  oxyseii  prevents  any  evil 
rlfrtrla  dne  to  brrathing  a  i-onflned  portion  of  air.     la  order,  Dowev«r.  to  avoid  all 

Cdlile  rrron>  sriaini:  from  a  (oo  re»tricle<l  atnioaphore,  a  dlflVrmt  iBMlind  has 
D  adopird  by  [Vinokofcr  and  Voit.  Their  apparatii* coDsists  cwtntiatly  of  a 
lanv  chamber,  capaUe  of  holding  a  lusu  conifurlably.  By  mean*  i>f  a  ntcam- 
«ngine  a  cnrrt'tit  ol  iiure  air.  mtaiueed  by  a  gwometer.  Is  drawn  tbrtiu^^b  lh« 
rlinmlrrr,  Meaturtd  puitionn  »l  tin-  outgorng  air  are  from  time  lu  time  withdrawn 
Mnd  anal^ced  ;  and  from  (he  ilntu  ofTurded  by  ibeoe  Hnalysct.  Ilir  *mouiitji  of  cur- 
1>nni<'  Mriil  (iindoibrr  jtimlBiid  of  Maicrgiven  olT  by  lh«occupaiit  of  the  chamber 
^uriiiv  a  given  tim<-  me  Jricfniincd.  Tbe  oxygen  coBnimed  »  not  determined 
tiirefiTy  ;  liBt  if  ibe  total  amoaat*  of  i-aihonic  acid  and  of  water  given  out  hy  the 
Innp*  and  akin  are  ascerlsined.  and  tbe  amount  of  urine  and  lecn  known,  the 
c|uantity  of  oxvf  ni  comumed  may  be  arrived  at  hy  a  uoiple  calculation.  For 
«vl(trnily  tbe  iiilfrreiK'c  between  the  terminal  weight,  plus  all  Ihc  egnta  and  th« 


\ 


Iiiitlal  wcigiil  plus  all  th«  itifwU,  vu  be  nuttiin^  oIm  ibait  tho  wcigbt 
DKXK^ii  abMrbM  (Jiirla^  the  pmod,  Thtti  mclbod  in  turn,  hoiroTrr,  iit  alto 
III  (>bjoctii>iM,  aincT  mmuui  <>rri>rii  in  th<i  HnalyM*  of  lb*  mokII  tamplw  nf  air 
I'liiplitjod  for  lh«  tbc  ilittcrminnlioni  nttaio  conaideraUe  dlnwadooi  frheu  tbett 
arvi  mul(ipti«<I  m  w  to  give  ihv  rbani^  in  tbc  wbole  nuM  «r  air  puaeil  throagb 
tlie  aii^Mratiu.  Il  ae<eiiia,  luureover.  u(idMlnb1«  to  lrav«  the  i|unntttx  UMd  of  n 
ini|K)rUnC  au  eleoient  hs  osygen  to  be  delermined  by  iii<liract  caluilMiom. 


J 


Let  lu  iinsKitie,  then,  an  experiioent  of  this  IcjikI  to  faav«  been  oonpl 
earned  out;  tnal  the  auimul'i'  iuitial  and  terrainal  «-eif(hta  have  baeu 
raiely  dHerinineil ;  tb«  ouuputttioD  of  tJie  fuodsatufactoriljknowu  tucioaairf 
of  ill  mucb  )ir»tei<l,  fill,  carbobydratM.  nalla,  aod  water,  itnd  to  ctiutaiu  »■ 
mui-li  uitm^-ti  nud  ciirltoa ;  tlie  woi^bl  nf  th«  fecM  and  the  DUn>i;*?u  chef 
contain  Biici'rtaiiKid ;  tbc  tiitrcifttii  of  (be  urine  dettrniiniHl ;  the  I'ltrlHiak 
ari<l  and  vtat<-r  givvn  off  by  ibe  wbi>l«  body  can-fully  niensiirud,  and  the 
Biuunnt  of  oxygen  abeorlH^l  ailuuUted — what  inl«r{in-tution  i:hu  Imi  pUowl 
on  tlw  raulU? 

I^  iM  «up|>c««  tliflt  tbo  ftiiimal  bits  gniiMMl  w  id  weight  during  lk«  jMriod. 
Of  what  d<fc«  w  ooiuisl?  Is  it  fat  or  |>n)leid  inntcritu  which  hiui  be«a  laid 
on,  or  simply  water  which  luis  l>con  rviaiued,  or  sonne  of  one  and  iorki  of 
other?  Let  lie  further  euppaw  that  ihc  nitrogen  of  (he  urine  puam]  du 
the  period  is  leas,  say  by  z  i>Taninic«,  than  tbc  nitrogen  in  the  fovd  Ui 
afUr  duduction,  of  vourae,  of  Ihc  niin>gea  in  the  feces.  This  meaos  that 
*  grnnimes  of  nitrogen  have  bean  retained  in  the  body :  and  wo  may  wilh 
reason  infer  llmt  they  have  been  fv<taiiied  in  the  form  uf  proieid  material. 
We  ntay  even  go  furllier,  nnd  aaj  that  tbey  are  reuiiied  in  tbe  form  of  Aeeli. 
i.e.,  of  muacle.  lu  thin  inference  we  are  ^n|[soiaew  bat  beyond  our  tether, 
for  (be  nitnigi^n  ruiKbt  be  ntored  u|>  aa  some  pruteid  constituent  of  live  hepatic 
oella  or  of  wmie  mlivr  I'tmue :  iii<ie«i),  it  inighl  be  fur  the  while  retained  t 
the  f'.iTm  of  wmin  Hitmgvuoui  cryxlidline  UiHly.  Itut  thti  last  event 
unlik<-ly  ;  mid  if  nc  \n«  tint  wnnl  "  tli«li  "  to  lueau  nilru^eu  (proteid)  holdli  _ 
liviiijt  nulmtance  of  any  kin<l,  wv  may  without  feMTof  any  SKM  error  n-ckon 
tbc  'lefii;iviicy  of  T  gnunnin  nitmgcii  »>  lli«  ttturing  up  of  a  j^inmeK  tInfL. 
Thcrv  utill  reniain  if  —  a  gTsninitw  of  iui-reaM-  to  bi>  luioiontii^I  Atr.  l.iH  i 
Bii|»pow  that  tbn  total  carbon  of  (he  i-giiila  ltiu>  been  f<itmd  to  Iw  y  griiitiim 
lew  llian  that  of  tho  ingnt4t;  in  other  wiirds,  that  y  griimmn  uf  varUin  have 
b««n  Nlon-d  up.  Some  carbon  hiu  bc«n  ittortKl  up  in  the  flesh  willi  t 
nitrogen  just  considerod;  this  wc  must  deduct  from  y.  nod  we  shall  tb 
have  '/  gramma  of  carbon  to  aecuuni  for.  Xow  there  arv  only  tnu  prti 
ctiKil  forms  in  which  csrbon  can  be  stored  up  in  tbc  bofly — as  glywtj^en  or  aa 
fat.  The  former  is,  avea  in  most  favorable  easra,  inconsiderable,  and  wc 
therolore  cannot  err  grenlly  if  ue  con^der  the  retention  of  ^  grammes  oirbou 
as  indicAlin^  the  layin;:  on  nf  b  f;rammee  fat.  If  a  -^  b  are  found  equal  to 
te,  then  tlie  whole  chan^^  '■>  the  economy  is  known ;  if  w  —  va  +  A)  Wve*  s 
resiilue  c,  we  infer  that  in  addition  to  the  layinji  on  of  fldsh  and  fat  »>iriw 
water  has  been  retained  in  the  system.  If  w  —  (n -)-&>  j^voi  a  uei;ativ« 
•(uaulity,  then  water  must  ha\-i-  l>een  gi^'i^Q  "^  at  the  mtne  lime  that  Unh 
mid  fat  were  laid  on.  In  a  similar  way  thv  nuluri'  of  a  Ium  of  weight  can  be 
BBOFrlaiiied.  wlieiher  of  flOHh,  or  fat,  or  of  walC'r.  and  to  what  extent  of  viicb. 
Tli«  careful  comparison,  tbe  debtor  nud  crmlilur  aocouul  of  inciinc  and  out- 
p«it,  «nahlM  tis.  with  tlie  caii(i<>n«  rcmlenxl  ni,'c<«utiv  by  tbc  i»aiim|itioD«  just 
iiow  mentioned,  to  infer  the  natiirv  and  extent  of  ibv  Wlily  chaugt«.  The 
nviilu  thus  gained  ought,  of  cuurfc  if  an  ois-ount  is  kcgit  uf  tbc  wnicr  takeo 
ill  and  given  Oiiit,  to  agne  with  the  amount  of  oxygen  conMimed,  and  nlav  to 
tally  with  the  conclusions  arrived  at  conceniing  the  retention  or  tbe  nvttm 
of  wilier. 


er. 
'-'      I 


THIt   STATISTICS  Of  XtTBITIOS. 


083 


I 


\ 


Havinj;  thus  Mudi^^l  the  mMhud.  and  ^«eii  its  woikneu  as  well  na  its 
etrenKtli,  we  amy  iHiefty  review  Um  rewilu  wliiuli  liave  been  obcoiued  by  its 
iti«aii8. 

^  OSS.  NilrvyeiMiiA  aiHiAolitm.  Wli«n  a  meal  nf  Icjui  cncat.  as  free  as  poe- 
»tbl«  {mm  tut,  la  ^iv<!ii  to  ft  dog  wliicli  had  [irevioiisly  l>M-n  deprived  of  food 
fvT  WPW  time,  mill  wlmow  bwly,  lliitrvfore.  in  jcmitly  deficient  in  flesli.  it 
inif^bt  b*  exptctcl  tliiii  l)i«  laru:vr  part  <>r  the  food  wDiilii  be  at  once  nutted 
tip  to  aiipplr  pri'R'ing  iti<:liri<-ncin>,  and  that  only  tbr  Mouilior  pari  would  be 
ioiRicdiiitoly  n»rk(->i  od'xt  urea  corn-sijiondiiig  Ui  the  pitrogt'nmii  ni<;laboli»tn 
going  Ml  io  tb»  body  tU  the  limo,  JDcriMHcd  MitnKwhat  bv  llw  iali<>r  tbniwn 
on  tM  tCMomy  by  th«  v«ry  proMDce  nf  the  food.  'fhw.  however,  io  not  the 
CMM  ■•  lir  M  the  nilrogpn  of  (be  nionl  in  cniicomH  ;  the  liif)^  pirtion 
pnam  off  »  urcti  at  once,  aod  only  a  cnmparalively  small  cgnantiir  in 
retninecl.  If  lh«  dirt  be  continued,  iind  we  are  enpjKning  the  mcal«  given 
t'>  1h'  large  ones,  tlie  propurtjon  of  the  nitrogen  which  is  given  off  in  the  form 
<if  nre«  goes  on  increasing;  until  at  last  a  condition  is  wtablisbed  in  which 
the  nilmgen  of  the  egesta  exactly  equals  tliat  ofthe  ingesla.  This  conditioa, 
whieh  is  egioken  of  as  "  nitrogeDous  equilibrium,"  is  altained  in  dogs  with  an 
exdiwiveiy  meal  di«lonly  when  larg«  qiiantitira  of  food  are  given,  and  it  is 
not  flBsily  maintained  for  aay  lenKlh  of  time.  The  exact  quantity  of  nicKt 
reqiitml  t>i  attain  nitro^nous  e<|uilibriuin  varies  with  ibe  previous  condition 
of  t1>e  <to|r :  e>:|uiiibrium  is  fr«(|ueotly  atlaioed  when  loOU  or  ICtOi)  |;ramin«s 
of  meat  are  given  daily. 

Tims  ihe  ni'xtt  etriliing  eJleet  of  a  purely  nitmgeooufl  diet  is  largely  to 
iiierease  the  nitrngemHio  nietabiiliim  of  the  bjdy ;  and  we  shall  see  Inter  on 
that  it  iurrenM-A  iIk-  nietabolium  not  only  of  the  nitriigejiouM  hut  also  of  the 
(itbrr  (■iiiisiiiufniB  of  the  t)ody. 

The  ntalilintiment  of  nitmgeuous  e<|nitibniiin  doua  uiA  luean  that  a  body- 
<-i|uilibiiom  ia  ntahli^lieil,  that  thr  iKnlyWdlght  neither  iucrfiinen  ni>r  diniin- 
iiilies.  <)u  the  contrurv,  vihvn  the  nif-al  m-eiiMtry  to  tialantH'  ihi;  nitrogen  is 
n  large  onu,  Uie  boily  thougli  it  ia  neicbi;r  gaining  nor  ln>in2  nilro^.'cn  may 
niD  in  total  weight;  and  tliv  iiicrvnM:  ii  proviil  hy  emlcnltition  fnmi  the 
FneoRiv  and  output,  and  in<h)cd  by  acttinl  examination  of  the  body,  to  be  due 
to  tba  laving  on  of  fat.  The  amount  »o  emnil  up  may  be  lar  greater  tbaii 
caa  ponloly  bo  aco(niote<t  for  by  any  fat  stili  adhering  to  tbe  meal  given  lU 
fmid.  Wb  am  tlicreforo  <lriven  to  the  eonclunion  tliat  the  protoid  food  i» 
Milit  into  a  urM  moiety  and  a  fatty  moiety,  that  the  urea  moiety  is  at  one* 
(liacbarsnl,  aiul  that  such  of  the  fatty  moiety  as  is  not  made  use  of  diractly 
by  IIm  body  is  stored  up  as  adipose  tissue.  And  this  disrujHioo  of  tbe  pro- 
t«id.  H  we  bnvi'  already  («  -1)4'))  suggested,  explains  at  the  same  time  why 
the  niwtdicl  so  largely  and  imnie^tiately  incneate  the  urea  of  the  egesla. 

The  charaderistiG  eflect  of  proteid  food  to  iacrease  the  metabolism  of  the 
IhmIv  is  shdVD  on  other  animals  beudw  Hiv  do^,  aud  not  only  by  means  of 
cKleuUtioiis  of  ii'hat  b  siippoKd  to  take  place  io  the  body,  but  nUo  bv  direct 
nnalysi;.  Thus  the  analysis  of  tbe  body  of  a  pig.  which  htui  lieen  le<l  uo  a 
known  diet,  ounipared  with  Ihe  aoalyeis  with  that  ofanotbc-r  pig  of  iheMtme 
litter,  killed  at  lli«  time  when  the  lirat  «'a»  put  on  the  lixi^)  diet,  gave  a»  a 
result  that  of  ibe  dry  nitrogtiioUN  muieriul  of  the  footi  only  nboul  7  |>er  rent. 
was  laid  up  as  dry  proteid  lUHlerlul  during  the  fattt^niug  period,  though  the 
amount  of  proteid  foud  nan  lnw.  Tbia  owitfrnMS  strongly  with  the  amount 
nf  fat  stored  iiu  during  tbe  name  period  (aee  £  A07).  nimilar  obw-rvaliuna 
cftn-ied  out  no  slieep  vlxiwod  that  in  ihstw  onimala  Ihe  storing  up  of  nitroge* 
lioUA  material  wa*  cvvn  lew.  only  about  4  |)er  cent,  of  that  gireti  in  (lie  lood. 

Every  quantity  of  proteid  material  taken  into  th*'  alimentary  mnal  thus 
ap|>enni  to  atfM-t  pmleld  mctuholiom  in  two  nays.    On  the  oiie  hand  it  excites 


631 


SITTRITIOX. 


a  rapid  protcitl  motnboliitm  giving  riM  to  ui  imror<luite.  Mid  gmcnllT  tiitf. 
iiu-raiM!  uf  iirr.i :  on  the  o(h«r  hnnd,  i(  abrvem  lo  miuiiuiii  tbe  nfm'n^tbr 
oornuil  {irotFid  mi'laboliam  roniinually  taking  piice  io  lh«  IxmIt.  hii<I  bdo«- 
tniHites  IO  the  normal  reguUr  dischar^^v  of  urea.  It  BWtus  very  latiitilb) 
feiippofce  that  the  proteid  which  playe  llie  first  r>f  thetv  two  parl»  'u.  tvA  ntiU 
built  up  into  the  tissues,  dote  nol  t>ecome  ai-tnal  liviof;  uibeuiicv,  bsi  aniir- 
^oe»  ibe  changes  wliich  givcH  rise  to  urea  outside  the  aniial  living  nbUMt 
tD  tbc  blood  or  eliewhere ;  and  we  bave  seen  that  under  the  iuDuoic*  </  ibt 
pKucreaiic  juite  ^oiue  of  ilie  prnieiil  food  may  uodergo  tbe  ffreater  piriiif 
aucb  a  chani^e  while  it  in  an  yut  uiihin  the  lUitueDtary  consl.  Heno*  Iw 
sriscti  the  verv  litiliiral  dintinclion  lo  which  we  hare  ulivndy  Blhi'leil  hctirna 
"  li»ue  jviiteiiU  "  nr  "  morpholic  protiiidn  "  which  are  artunllv  liuilliipinlniW 
llvinu  Hubctuncft  nf  the  tiwues  anil  give  ri«c  to  urea  thmujin  the  inciaMifs 
of  living  *iib«tancH'.  and  "  circulatiDg  proti^da"  or  "  floating  pn>lrid*"  wtidi 
do  nol  nt  any  period  of  their  rarc^^r  itithiu  tbo  body  becoiDc  n»  inl^grd  |arl 
of  the  living  Rnb«1«n(v  and  by  their  indaboluni  .-H-l  ftrt  wwrgv  wit  in  ik 
wny  nl' vital  mnnifcxtalioos.  but  in  lh«  form  of  hoal  only.  Wv  nliall  lUtna 
consider  what  if  the  exact  meaning  which  vre  ought  In  mtuch  to  tbf  wonb 
"  bccnniing  part  of  the  living  aub»tftjice :"  and  hence  tball  d«f«r  uotU  tlcfl 
uny  iliKcUMion  of  the  appropriatenen  of  theitc  phrowe  and  of  llie  validity  of 
tbc  <Hstiticrion  which  ihcy  I'nrmulatc. 

It  was  Diicc  ihotight,  at  we  shall  presently  8W  erroneously,  that  tbotadil- 
sive  piirpoM  of  proteid  food  was  to  supply  ihe  proteid  tissues,  and  lliU  ill 
the  energy  tet  free  in  the  body  in  vital  nianifefltaiions,  such  as  movement  Uid 
the  like  ait  distingiiiHlied  from  heat,  had  its  origin  in  pmteid  metahDliem.  Ik 
meiaboliMD  of  fats  and  carbohydrates  ^ving  rise  lo  beat  only.  Heficc«lM 
it  lirst  became  known  that  a  certain  proportion  of  protetd  food  appanulf 
underwent  a  meiaboltstn  giving  rise  to  heat  oulv,  witlxrut  becotniug  faitof 
tbo  liMiiies.  ihin  •wcnieil  to  he  a  wn»iefiil  exucntliture  of  preciou*  aialtrill: 
and  the  mclaltoliitni  of  thin  portion  of  prolcia  Ibod  wai  accordingly  «palUA4' 
iw  a  "  luxiiaconHuiDption."  ■  wasteful  coniumptioii. 

Iteforv  leaving'  Ibis  suhjcot  wc  niny  cull  nttontioD  tu  *  powibic  UuNp 
hoiwcrn  the  hietnry  of  prolcidx  and  that  of  fats  and  cnrhohydrnlffL    TM 
iiDtlnrm  eomptxition  of  the  blood,  which  the  body  n<0Ow  ever  olriving  Id 
iDuintnin,  probably  applies  to  its  prolcidK  as  well  as  to  ilx  other  conttilurnb. 
We  have  seen  that  a  sur]ilus  of  non-nilK^genous  mnd-rialN  in  the  bl'Md  ii 
withdrawn  from  the  circulation  and  stonfl  up  as  fat  or  glycogen,  and  it  it 
IHMi^ible  iliut  an  excess  of  proieids  might  similarly  be  stored  up  in  sonatkne 
or  ti.'riues.  in  the  hepatic  cells  for  inKtauco.  though  from  the  facts  previously 
nietitioned  it  is  obvious  thnt  the  power  of  storage  is  far  le»i  ibun  in  th*  cm 
of  fal#  an<l  carhu hydrates.     .Such  a  store  of  proicid  matter  would  n-|ireeefii  a 
aort  of  circulating  pruteiil,  but  uevenheleae  fur  its  linal  metflWIium  inighl 
liave  lo  form  an  integral  part  of  some  living  tissue  unit. 

^  924.  Tfie  ffrrl'oij'attiiiin'i  nf  firtrohydratr  food.  Unlike  tltnee  of  protMd 
food,  the  ellL-ct»  of  likts  and  earbobydratea  cannot  be  studied  aloue.  \Vb«a 
an  Hiiimal  i*  fed  ximply  ou  uon- Diirogeiiou»  food,  death  won  takes  place: 
the  foot)  rajiidly  o-hm*  to  be  digcM4>d,  and  Hlarvaiion  eniueti.  We  can  tbere- 
foiv  only  study  the  niiiriti^'e  eflbcts  of  thcw  subsuinoa  when  tliey  are  token 
(O0Bther  with  proteid  niatirrial. 

»h«n  a  small  (pitiiitiiy  of  lat  is  taken,  in  company  with  a  Bx«l  niodenue 
ijuantiiy  of  proteid  mnlerial.  tbc  whole  of  the  carlioii  of  the  toivl  roappean 
iu  the  egesia.  No  fat  is  stored  up:  »onie  even  of  the  [ircvioui>ly  exinting  fat 
of  the  body  may  be  consumed.  As  the  fut  of  the  meal  in  iocreaMvt.  a  (loint 
is  soon  mohed  at  which  carbon  is  retained  in  the  body  n»  faL  80  al-o  with 
starch  or  wgar;  when  the  i|uanlity  of  this  u  tmaW.  tberv  is  no  retention  of 


TITK    STATISTICS  OF   yi'TRITION. 


e.'is 


I 


I 


oa  MMii  Imwen-r  hn  it  Lt  iiicmtM^l  bcyoni)  a  c«rtii!n  limit,  nr)»>i>  i* 
:>  in  tb«  form  «r  fitl  ut,  ui  b  «niiillvr  vxtvDt,  na  givoogcn.  FniA  mid 
c'iirl><>by<)ruie)>  lhercfi>re  ilillcr  markmllv  from  proleid  fowl  in  thnt  ihi-v  iirc 
ii<i(  Ml  (lUltm-lly  pmT0(-4itirc  of  melnbofiani.  Ihis  is  escee<lio|;)y  well  bIiowii 
in  the  iTtiillK  olvtiiinni  on  thtt  pig  previously  inentioned.  ll  was  found  ihal 
472  uiiiu  of  riit  Kvre  laid  on  fur  ev^ry  lOO  uniu  of  fat  taken  aa  sucli  in 
llin  food  ( which  cmuistinj;  of  bnrley-nieal.  vie.,  conlained  a  v«ry  Hoall  amount 
of  aiTiiiBl  fnri.  while  tor  every  100  units  of  the  total  drv  non-iiilroj{«noiia  food 
indiidinj;  fat,  ttarcb,  c«lluU«e.  etc..  no  I<^m  than  21  unita  were  retained  in 
%ltv  biMiy  in  the  form  of  fat.  Jio  clearer  pnxif  than  this  <:oiilii  be  atTorded 
that  lal  is  formed  in  tbe  body  out  of  Homrtbiitj;  whivh  h  not  fat.  In  !;  o08 
we  have  already  disounMi  thu  formatioH  of  fat  out  »f  i-iirbnliydrulea. 

At  one  u))k1iI  imagine,  tbe  pra»en«e  of  lint  or  carbobydrutt'n  iu  iIkt  fuotl  is 
fonnd  to  decreiue  tbe  ainouul  of  proteid  material  iiiK'CMitry  to  ■•Mtuhliah  nilro- 
ftenovs  equilibrium.     For  indnnon,  with  a  dii-t  of  HIXJ  grmK.  mc^ul  and  ISO 

Srins.  fat,  lh«  uilrou^n  in  the  e){i-i>iit  Iwcnnie  equal  Ut  that  in  thu  iii)i;isia  in  a 
Ofc,  in  whiMC  caite  IKUO  grinii.  meat  had  to  b«  given  to  produce  tlie  «ame 
retiult  iti  lli«  nIkh'Iici^  of  fat«  or  carbohydmtcfl. 

>Ou  ib«  cithiT  Imnd,  it  was  fmiod  tnat,  with  n  fixed  quantity  nf  fatty  or 
CKrlv>hydntli-  f»<Hl.  an  increa^c^  of  the  acoompanyinK  jtroteid  led  not  to  a  akiT' 
iog  up  of  tlie  surplus  <^'arl>un  contained  in  the  extra  ()URntity  i>f  pmleid,  hut 
to  an  incruue  in  the  ooneuiii]>tion  m'  carbon.  I'ruleld  food  increows  nut  only 
pr<>tei<I  Init  also  iton-nilrueeuous  metabolism.  This  explains  bow  an  exnw 
of  proteid  food  may,  by  tne  inoreoie  of  ncneral  nietaboliam,  actually  rwltioc 
the  fat  of  the  tmdy. 

Wc  have  al  preeent  do  exact  information  coDcierninjf  the  nutritive  diDer* 
encea  betireen  fats  and  carbohydrates,  beyond  the  fact  thai  in  tbe  final  com- 
bustion of  the  two,  while  carl>ohvdrale!i  require  Bullieient  o.xygen  lo  combine 
with  tbeir  carbon  only,  th«re  btfiui;  already  MiAicieDt  oxygen  in  the  carbo- 
hydrate it«elf  to  tbrni  water  with  tb«  hydragen  pmwnt,  fku  require  in  addition 
oxygen  to  combine  with  mxne  of  their  hvdn>tfen.  Hence  in  herbivora,  living 
largely  on  carbobydrati-H,  a  larger  |Mirliou  of  tlu;  oxv^feii  cuUHUmed  rvajijieare 
io  UM  carlM>ni<-  add  of  the  egota  than  In  carnivora,  in  which  animals,  living 
chiedjr  on  pruteids  and  fat^i,  more  i<f  it  Uuivoa  the  body  combined  with  hydro* 
gen  to  Itinii  water.  Thin  relation  of  tbe  oxygen  toihe  carbonic  acid  i^  ol\en 
exprtaaetl  bn  the  quotient  of  the  volume  uf  the  carbonic  add  expired  dividol 

by  tbe  volume  of  (be  oxygen  eonBUtuc<l,  the  "  respiratory  quotient,"    =^\ 

which  ia  in  herhivora  about  0.9  and  in  caniivora  about  0.6  or  0  7.  When  a 
herbivorous  nninml  tlarvo',  il  teeds  on  its  own  fat,  and  niider  liieso  circiim- 
Mances  the  rc^i  pirn  lory  quoltenl  falls  into  ibe  carnivonma  standard;  and 
indeed  many  ciicuntMancea  afleci  ibis  respiratory  quotient.  The  carbohv- 
draUw  are  notably  more  digestible  ibau  tbe  fats,  but  on  the  otiier  hand  the 
fau  contain  more  p«)teniial  «ner{>y  iu  a  Kiveii  ncighi.  Aa  u>  tbe  nulritive 
dtArenoe  between  Blarcb  and  HUgur,  wt-  Know  nothing  very  delioite;  it  haa 
becti  ih'>u;;ht  however  that  cane-nii|i:nr  i.-i  riither  more  Eattenin^'  thnii  starch. 
S  535.  Thf  efirH*  oj  iiflalin  a*  food.  Il  in  a  matter  of  common  exjierieuce 
that  gelatin  will  not  Mipply  (be  place  of  proti-ids  n^  a  coiutitui-nl  of  lixxl. 
Animal*  M  on  gelatin  tugelber  wilb  fat  or  cgtrbohyd rales  die  very  wuub  in 
th«  same  way  aa  when  they  are  fed  on  noii  nitrogetious  nmtcrial  aloue. 
KevertbeleH  it  w»uld  ap|>ear,  its  might  be  expcclcd.  that  ilie  prewcnee  of 
gelatin  in  food  ii>  not  Hiibunl  cHi?cl.  This  nittxigciiuus  equilibrium  is  cMab- 
Kahed  at  a  lower  U'vcl  of  real  proleid  food  when  gelatin  is  added.  I»  a  dog, 
Moreover,  fni  ou  a  diet  of  gelatin  and  fat,  ihe  exccas  of  nitr<>g«n  in  tlie  excreta 
over  tfaat  in  tbe  iug«ei«  is  l«w  than  when  iIk  same  dog  is  led  on  a  diM  of&it 


I 


636 


WITTBITIOX. 


■KiiK' :  thiit  ix  to  Mv.  thi-  gelatin  liii>  kIk-Iivi-mI  fr»m  meuttolnn  suiiiv  pnMtU 
CDnHUCm^ulv  ••rtliL- IhmIv  :  aii't  thv-  cPDitimiHkiu  •>r  fat  »o«iiu  also  U>  IwlearMl 
by  tlw  |>wwiioe.  >'f  gi'btin.  These  fiictt  iK-TOtin;  iotvllifriUI*-  if  we  suppnee  ital 
]fi.>laliii  is  rnptdly  ejilit  up  inU>  ■  ur«a  «n<l  s  tiit  raok-ly  i»  tbe  Mime  •ny  ibn 
wu  luivc  M^i  a  cof  tain  quaiiliiy  of  prolcid  material  to  W.  It  b  this  ilinci 
<UMrui7tivc  m«ubolist»  of  protettl  matter  which  gvUlin  on  take  up ;  it  bcm* 
however  unable  to  imitate  ibe  otber  functioD  of  proteid  ntalt<^r,  nnrl  to  takt 
piiri  in  the  formation  of  liviuKSubatance;  or  id  the  phraMM)l(>gy  of  a  nncBl- 
iiig  pniah'Tapb  i  $  -V^^),  it  eaii  lake  tlw  place  of  ciroutaling  but  not  »t  tiMt 
pruleid.     What  is  the  t-aiiK-  of  tJiia  ditTereiice  «e  fiinnot  at  pr<wi«iit  »*r.      • 

S  886,  J'eptone  -isjood.  SitK-e  prol«i(la  are  at  leant  lar(^ly,  tu  wc  have  mm 
(!i  310),  convened  into  h»<1  ntiHorbed  a*  p«^|>li>m-,  awl  iiDce.  aa  «r«  have  aW 
aeea,  the  peptone  Bj>|R-jin><ltiriii^'  the  very  Mit  of  nl»orption  to  b«  i«coiiV«tt4 
into  noiue  oihrr  form  of  nroli-iii  mntt<T,  |Kmibly  wMTim-albwiuin.  it  nii^ 
M'L-m  natural  to  aiijipim:!  thai  pi-jiloiie  given  n*  fmMi  woubl,  u-'  far  a«  iwta- 
bolUm  n  cunrpmiil,  play  tbi.'  onmc  juirt  nit  other  prol«idN.  NevertbelM. 
WHue  ob»erv<T#  have  timii)tnin«<()  nitb  regani  to  both  peptone*  luiil  the  alM 
albiimoM*  that,  like  gcliitin,  tbese  bodies  "  can  lake  tbe  place  of  circulalini 
but  not  of  tisMie  proietd."  On  the  whole,  however,  tbe  evidenoo  guv  lA 
«b«u-  tbut  Atiiroaln  can  **  lav  on  flesji  "  when  the  protetd  in  their  (nod  ettoiiA 
fjitin'ly  of  peptone  or  albumose.  A  difficnlir  ap]>ertaining  to  digmioa 
prevents  any  large  snbAtitulion  of  ]>eptone  for  ordinary  proteiids,  stnei  M 
might  be  expected  diarrhcea  ia  apt  to  l>e  set  up. 

gAS7.  The  rfcel*  n( niiU  a* Jood.  All  food  oonuinB.  besides  the  Bubstanc* 
|)oaseB»iof;  potviuial  energy,  which  we  have  Just  studied,  certain  raUoe  imI- 
tera,  orKanio  aiul  inorganic,  haviiix  in  themselvei  little  or  no  aiicb  |»>leoliil 
eowrgy,  but  yet  either  abtolutely  oeonwiry  or  ht^ily  beneficial  to  the  boiU. 
ThcH  uiuai  luive  imporlaut  fuuctionx  in  directing  the  meubollam  of  Um 
liody  ;  the  xlrikiiitt  dintritnition  of  them  in  thv  tewnw,  the  prepondenuxwef 
sodium  atid  i-hli>ri<lni  in  blood-iN-rum  ami  of  poULMitim  and  phoapbalfls  In  tbt 
red  CDri>il*cl«a,  lor  ini<tani-ii>,  m\t*i  have  »omc  meaning:  hut  at  prca«fll  a* 
•re  in  ttie  dark  oin-eriiin^  it.  The  clrmont  phosphoniR  ik«iii<  n<>  ti'M  impv- 
lant,  from  a  biulogiml  point  of  view,  than  carbon  or  nitro^n ;  it  i«  a*  aW 
lutcly  (wenttal  for  tlie  growth  of  a  lowly  being  like  I'enicilliiiin  as  for  man 
hini»elf  Wo  find  it  probably  plnying  an  iniportani  part  «  tbn  conspioi«<U 
i-onstittient  of  lecithin  and  other  complex  fats  belonging  10  the  nortwui 
BVrtem  ;  we  find  it  prumineul  in  the  iwculiar  body  nuclein ;  we  Hud  it  pecu- 
liarly associated  with  tiie  pruteida.  but  we  cannot  explain  its  rd/r.  \ht 
element  sulphur,  again,  in  only  ancond  to  phoapborus,  and  we  6ml  it  a*  a  odd- 
atttueiit  of  nearly  all  proteio*;  but  we  cannot  foretell  the  exact  ohaii|pi 
which  would  take  plaou  in  tJi«  economy  if  all  the  Bulpbur  of  the  fond  wV 
withdrawn.  In  the  kreatin  of  the  epidermis  and  iu  appendagea,  hain,  <M. 
it  \»  pruliably  undergoing  vxcrciion,  though  its  proaeum  id  thin  iHKly  nuf 
have  to  itu  wit))  the  jwciiliar  }>hyi>ind  charucioni  of  romemw  epitbeliuni. 

We  know  that  the  various  saline  matters  are  Mamtial  tit  health,  ihM 
when  they  arc  nut  prir««nt  in  proper  pro|iortiont  nutrition  U  a6i>ct>^l.  \iop 
fed  on  ftiud.  fremi  as  mui-li  a«  possible  from  alt  saline  matlcre.  but  othorww 
abundant,  with  a  proper  proportion  of  the  food-stulltf,  soon  exhibit  symplwD' 
showing  that  the  metal>oliam  of  their  tissues,  (ia]>ecially  of  th«ir  nutnl 
nervous  system,  is  going  wrcmg ;  ihe>-  sufli^r  from  weakneaa,  aoon  amoualipt 
to  panilysis,  and  are  often  oarried  off  by  conviiUiona.  And  innrv  or  iM 
similar  derangeroenta  of  nutrition  follow  the  aboence  or  a  delicieiirv  of  indi- 
vidual aalta.  During  atarvation  thcste  various  aalls  continue  to  lie  diaclumc*' 
fVom  the  body ;  in  aoiue  way  or  oilier  they  are  carrie<l  along  in  the  metabolic 
ttreaiu,  and  ih^ir  pretence  b  in  .vume  way  eaaential  to  the  varioit*  mvtaholic 


THB   ENSBGY   OF   THE   BOPY 


687 


hmor,  ili«y  iMiiH)  lo  be  mlwav*  iiit^ent  iii  iliiily  Tiiol.  In  whnl 
■ajr  tl  b  tfail  tlu'v  tliuN  ilirwt  iDdnbcilisti)  ur  do  ii»t  knnw ;  wo  nrc  a«'ur<! 
tut  tta*  pmporlHti  anil  iMUioui  of  vnrioux  jiroLriil  »iib«Uincc»  uro  clotvljr 
llpMHlntl  nn  Ihi;  [>n>wrn«e  of  Mrlain  mil*,  but  buyiiiid  llii«  ws  know  verj 
Uubu  Tbf  inorganic  Mlt#  nro  lhi>w  tho  imiritivc  value  ul*  which  hiu  bcMi 
|U*djr  *(U(lii-<t  by  expvHim-tit.  Iml  wr  liavv  n.iwu«  «>  bolievo  thac  the  or);>ni« 
<ir  vxrafnivo.  which  iirv  prcwi-Dt  id  grantor  or  Icm  <iuantity  in  all  food 
tt  both  vrnUtble  umI  atiiiaul  origin,  are  no  \em  cewntiat  to  the  proper  meta- 
Uic  iHiiTilic*  of  ibe  bwlr.  The  iindoulitod  connection  of  scurvy  with  lltft 
i»rk  iif  fmb  v«gFt*blt>  fiwcl.  other  conditions  helping,  rosy  rierha|>«  turn  in 
fan  uu  tUts,  for  lh«  erideiiL-c  that  the  <li»e4iHe  is  due  lo  l)i«  deflcieney  of 
pstasb  alone  u  not  eonchisive. 

tjutly,  water  ha«  an  HTed  on  meinbolisni,  us  shoirn.  antunjt  other  things, 
Vf  the  fni-t  that  when  the  water  of  a  diel  is  iodvased.  the  urea  is  inorMMd 
to  aa  exienl  Iteyond  that  which  can  be  eiptniucil  by  the  incrcMe  of  fluid 
bcRMMUK  the  facilities  of  mere  excrelion. 

The  Enkroy  of  nie  Body. 

The  Tucome  »/  Eneryy. 

S  ASS.  Bnuidly  ^prAking.  the  nnimnl  tmly  it  n  machine  for  couTertitiE 
'Mtiai  into  actual  cnorg}'.     Thi-  putcntlnt  eiwri^'  i«  ciippticd  by  food;  ibu 
■feCtabolisin  of  the  body  convert*  into   (he  actual  energy  of  heAt  and 
Bical  labor.     Wc  have  in  llie  prevnl  •oclioii  t>r  study  whal  h  kmiwn 
laws  of  this  convomoii,  nnil  of  the  <li»trihutioQ  uf  the  eni^r^y  *el 

Ccttkatlog  all  tubaidiary  nod  untiu|M>TUut  Mure«a  of  «nerev,  we  may  say 

t  UN  ineofue  of  animal  enerfty  cunsiftis  in  the  oxidiiiioii  of  food  into  ita 

'Iprodiivta — vtx..  the  nxidulion  of  pni(ei<i.i.  fal*.  anil  carbohydrates  into 

irbonic  aeid.  ami  water.    A  principle  laid  down  bv  the  chemist  teaches 

a  potrntial  enrr^y  of  any  bgdy,  cuUMdcrcd  in  rvlntiun  to  any  cbeniicoJ 

luee  which  it  may  nndcrgo,  {a  the  mtat  when  tbo  final  result  is  the  same, 

,bpr  that  mult  be  gained  at  one  leap  or  by  ■  scries  of  sle|n:  that,  for 

nor,  the  energy  set  (m:  by  the  oxidation  at  1  grm.  of  fat  into  carbonic 

aiKl  wat«r  is  the  Mme.  whatever  the  changes  forward  or  backward  with 

fat  undergo**  lH-f<ife  it  finally  rencbcM  the  stage  of  carbonic  aciil  and 

r;  and  similarly,  that  the  energy  Available  for  the  body  in  I  «rtu.  of 

proleid  is  the  energy  gjv«D  out  by  the  complete  combustion  of  tliai   1 

Im  the  cnerey  given  out  by  the  coRiplete  combustion  uf  that  i|iiimtity 

~l  to  which  the  1  grm.  of  iiroteid  gives  rise  in  the  body.     Taking  this 

irnir  guide,  we  can  reiulily  calculate  toe  amount  of  potential  euvrgr  C0JI> 

■ml  in  an  average  Iweiily-I'our  boura'  diet,  and  thus  obtain  the  avera^^ 

iiicunM  of  energy.     For  the  potential  enetvy  of  ninat  of  the  aubMoacn 

as  food  has  been  determined  by  direct  enbmntetric  obaervatiMw;  umI 

wveral  determinations,  tboueh  il>ey  vary  soraewhat.  ngnc  sufficiently 

1y  111  serve  en  data  for  the  calcitlaiions  in  i^ueatlon. 

le  total  i-oinbuitionof  thefidlowinKHibstanci-a  ha.H given  for  oiie  gramme 

•ubdauce  the  fullnwiug  results  cxpreMvd  in  oalorica— tluit  is,  id 

uuilf  <if  heat : 
,  fVee  fVom  fat.  -^103  aixl  5.^24.    Fibrin.  A6I1.     E)!g-albiimin,  o-'iTS. 
lis,  taking  rnun<l  numbers,  we  nuiy  kav  that  1  grm.  ol  proteid  material 
ntaius  /fiiiiil  or  5,'>iiO  cnlorieii  of  potviilial  energy,  aeoonling  as  we  use  the 
■pr  Of  higher  dctenninatiODH. 


633 


SCTBlTIOy. 


Fai  of  l>eefnr  mutton,  90UU.»36o,!)42;l.  UuU«r.  721(7  nr  9192.  Apii, 
ID  rvuud  numben,  we  may  auy  tfa«i  1  grm.  of  fat  conlaiiis  Ktiotii  90<»ntln- 
ries. 

Arrowroot  (nenrljr  pure  March),  3912.  8larc)i,  4123.  ll^llulaw.  4Hii. 
Dextrose  :)G9'}.  Uine  Kugar,  38(i6.  Here  again,  taking  round  nuRilm,*t 
AM  not  be  fiir  wroTiv  in  MvidK  ihat  the  pntAiitinl  t:\Krfiy  of  1  gna.tt{  rtAit- 
hy<lntl«  mnlvrinl  i.-t  aliinit  -tOdO  calorics. 

The  comhuHliim  nf  1  grni.  of  iimt  *ot«  free  an  amount  of  riivrgr  vlilcbhw 
been  (ii^tcrtiiiii'd  l)v  dih-  oli:irrvrr  n»  'JJOB,  by  iinotlMT  as  i4(i-'>  calurieiL  Vr 
havceccn  (,ji-W>*)  iliiil  I  gnu.  of  i>rot«itl  giv»!>  riwJ  in  tl»  body  to  iitnamna. 
tleoci',  to  obtitiii  Ui«  eiiergy  ol  1  grni.  prolci't  mulcrial  arailable  (iir  ik 
ecoDcimy,  n*c  must  d«luct  from  it«  |mtciitinl  energy  oiie-third  ibepoWniiil 
coergy  of  I  griu.  uren — that  i§.  in  rotin<l  numbcra,  TUU  or  tM)0  calonot.  Th 
will  ipve  UB  oOOO  ^  700.  or  .^501)  —  >H>I>.  ibat  is,  4:tOU  or  4700  caloriea.  amri- 
joj{  ■•  we  uko  the  loirer  or  hif:lier  d iilti ;  or  ue  may  take  n  a  nMao  4U0 
oiloriea.     The  data,  then,  so  far,  are  &«  folloirs: 

I  l-raiiiDie  proleid -I-VW  calotw*. 

1  grunimf  tat 9rtXi        " 

1  grnnimc  cnrbohydrnio 4U(fO 

The  average  diet  of  aii  average  nmn— ibat  is,  the  at:%ni^e  auouiii  ofeKt 
fixxl-atufT  reapectivcly  laken  daily — n*^  be  det«rniiiKd  ex[>eriincDlally  « 
»laii:^ti<altv.  TbuB,  a  mau  may  aMermine  by  a  seriM  of  triala  tlie  did  m 
wliit-h.  while  ndtber  louag  nor  gainin;:  weight  and  Riaiiitaining  "  nitrugtowi 
emiilibrium  "  (5  523),  be  eojoye  (rood  health.  Or  ati  nviTage  may  be  tUwk 
of  a  iarge  number  of  dieia  u»ed  by  varioos  |)enple.  Wenhall  have  twintlliint 
to  Ay  o?  this  I&lt«r  Btalisiical  method  when  we  come  to  ji|>eak  of  die<.  For 
the  |tK«eDi  purpose  we  may  use  one  arrived  at  experimenlally,  nlikbut 
will  »|>rAk  111  a.1  RaukL-'s  iliei,  taatx  it  wan  deterqiincd  bv  a  |ibysioli)f;ifl  U 
that  onmi!  frnm  uliwrvatiomi  on  biniMlf.  It  w««  compdn^i]  of  lOHllgnia. 
proieid,  100  gnrnt.  iat,  '240  grnift.  carboliydrate.     Such  a  diet  would  gire 

inogrammniproteid  (V'HMJj Idtt.UOO  calories 

lOOgraniina  fat  (9i>'>r)) 900,001)        ■* 

310  srammoi  carbohydrate  (4000)  ....    900.000 

2.310,000 

If  we  translale  the  unii«  of  lieat  into  units  of  w-ork.  tlie  2/110,000  graRiine' 
dr^nve.  or  'Z^ilO  kilugraoinio-degree  calories  will  give  ua  about  IMO.OOO.Of,  in 
rouixl  iiiimtren.  Aomcwhere  about  one  milli<fii  kilogramme-metmi. 

Wf  may.  in  pn»iTig,  ctkll  attention  to  tlit?  faoi  that  Ibi?  pmieide  «i|iply  a 
rclntivcly  ixnall  part  of  lh«  total  eoorgy,  and  ibut  ibe  nbarc  runlrihuled'by 
the  lar^ji-  niaM  of  carbohydratet  ia  Dot  much  grt-altj-  than  that  belonging  in 
the  much  unuiller  ijuantiiy  of  fat.  In  the  averaj^ii  dirt  obtained  br  llii;  au- 
tislical  method,  in  which  the  data  are  largely  dniwn  frnm  public  itiMttuticnu, 
the  (cbcapcr)  carbohydraliw  aru  atill  furtli«r  iacreavvd  at  ibc  eKpeuae  of  tltv 
(dearer n«t«.  a  change  which  may  tend  to  reduce  tonwirbat  tbo  total  ener^; 
but  thi«  docs  not  materially  afTveC  the  broad  mtult  jnM  giren. 


Tlie  ErpenilitHre, 

S  529.  There  are  two  ways  only  in  wliioh  energy  «  •W  f'"*'*  from  the  body; 
me«linnical  labor  and  heat.  The  body  losw  energy  in  produting  muscular 
work,  u*  in  looomoiiou  and  in  other  kinds  of  labor,  tn  the  uoveiDcnta  oflbe 


TDS   BXEROV  OF  THE   HOW. 


688 


I 


I 


iu  nxpiruliixt  tttid  siwccli,  ud<1.  though  to  ii  )inrtllv  ns.>ogaixKbl«  exttdit, 
h<'  niovcnM-iiis  of  tli«  uir  i>r  contigiioiiK  boiliut  tiy  tliv  piilMlioiisor  Oat 
vasnilnr  HTRlcm.  Thv  body  loan  cnergr  in  the  Ibrm  of  hmt  l>y  i:«iidiictii)ii 
And  radiation,  l>y  r»piration  tind  perepirnlion,  iind  by  th«  warming  of  lh« 
urine  and  feces.  All  ihc  intcrnKl  work  of  (lit'  iiody,  all  the  niechiinkiil  labor 
of  ilie  internal  musi'ular  niecliamsnis  uillt  their  accoiupanyiDg  friction,  all 
the  luolM^uUr  labor  of  the  nervous  and  other  tiwura,  is  coiiverl>-'d  intu  heat 
before  it  leavee  Ibe  body.  The  inoet  intense  mental  nciiou.  unaocoiupaDied 
by  any  niuwular  man ifntal ions,  the  nii»t  eDeT;geltc  action  <>(  the  heart  or  of 
the  howeU,  with  ibe  ali^-lit  esoeplioDB  nieutioued  above,  the  husit^t  activity 
of  the  jWcretinK  i>r  uietabdlic  itMues,  all  tbe^^  eml  Biui|>ly  tu  aiigmeutiug  tlie 
cxpouditure  in  the  form  of  h«at. 

A  normal  daily  rX|Mmdiiure  in  iho  way  i>f  mec-bniiival  labor  van  be  eauily 
<lfitermiiKvI  by  obm-rvaliini.  Wht-lhrr  itiv  work  liiki-  0:1  lli<-  form  of  nalk- 
iug,  or  i>f  driving'  a  niarhim',  i>r  nf  any  kind  of  iiiuxciilnr  toil,  a  ^>iKt  day'« 
work  may  1m;  |>ul  donn  iil  abotiL  l^O.IKKt  kili)j;nimtiii--m»trcK. 

The  normal  dnily  rxjicndiliire  in  th<!  way  of  bi;iit  aiiinoi  W  «>  readily 
deterraiiM-d.  T>itvct  (-alKrinH'iric  iib»ervulioi)*  on  ihi^  whole  bodv  an-  nttrudvd 
with  B»  many  ditlivtillMs,  except  in  tht-  »uc  of  nmnll  nnimaU,  (bat  ilivir  valui' 
w  UMM^rtain  :  and  oWrvaliun>  miuU-  by  plannu  a  part  <mly  of  tbi;  body,  an 
onn  or  leg  for  example,  in  ihti  ealorimcler.  and  from  ihc  data  thiin  gained 
calculating  the  heat  produee<!  by  tJie  wh<>li>  body,  arc  siihjccl  to  nmny  «oiir««e 
of  error. 

The  caWimeicrii  uiually  employed  in  chemical  operation*,  in  mrJuurinK,  for 
initlance,  the  b«Hl  ^nven  out  in  chemical  vbangM,  are  uiisuiiable  for  rt  peri  men  In 
on  liviiift  NU>m>l*,  l^ucli  are  the  mercury  calonmeler.  in  which  ihe  iliemical 
aetlon  to  be  ■(tidied  t»  nmde  In  tnVe  plncr  in  tlic  inirlut  of  a  miuw  of  mercury,  from 
tite  cotiKcnueot  expuniiiin  nf  which  tlimujfh  thi^  lirAt  taken  up  the  iimount  of  heat 
givaii  out  ■■  calculat(<d,  or  the  ice  otlorimeter  in  which  in  a  HJiuiluy  way  the  heal 
KiTen  out  la  calculaled  from  tlie  amount  of  ioe  melted.  TIh-  latter  hasbren  used 
7<ir  phyTiio><>^ic)il  purpose*,  but  an  animal  eurroiniiled  by  ice  is  under  micfa  abiior- 
■nal  conilitionii  llial  (lie  m>ntlii  are  of  little  value-  The  method*  usnully  adopted 
liy  phyi><>1oiitKliL  ate  an  rollnwH : 

la  one  method,  the  water  calorimeter,  the  animal  h  placed  In  a  metal  chamber 
iKirr»uaded  by  a  jacket  lilted  with  water.  The  heat  given  out  by  the  animal 
warms  the  water  in  the  jacket,  and  the  amount  given  out  i*  calcniiiied  upon  ibe 
Incraasa  of  tbe  temperature  of  the  water,  Uy  supplying  (be  anlDial  witli  air 
tkrougb  a  Iork  apiral  tabe  paaaioc  throagh  tlie  wiiter-jiicket,  the  heat  given  out 
in  tti«  expltea  air  is  urereoied  Inua  being  lost. 

This  method  may  be  employed  in  a  Klmplei  foiin,  when  the  beat  given  out  bv 
apart  of  the  lH>dy.  the  arm  or  leg  for  intUtnce,  i>  all  that  hiu  lo  bo  detcrinincd. 
Tbe  pert  in  Ibca  mrrety  placed  in  n  bath  «(  water,  from  lht^  cbntira  of  tempera- 
lure  of  which  the  Hmuuni  fiven  out  ■■  cakulmcd.  And  thii  modi  flea  tluu  of  the 
malliod  may  with  dae  precaution*  be  employed  for  the  whole  body. 

In  tto«enlluir>'  calorimeiier  the  cbamhcr  in  which  the  body  or  iiart  of  the  body 
ia  placed  in  *urroundeil  by,  not  n  wnler-jackel.  Iiut  an  air-jacket,  which  thua  Mrroa 
aa  aJi  air  calorimeter,  Tbe  iDnirumeol  consiitH  ewcDtially  of  three  couoenlric 
cop|ior  ryliiidcr!! ;  the  inner  one  contains  llic  animal  (or  other  ouurce  of  beat) ; 
the  other  one  >H-rv«M  mricly  a*  a  casing  to  protect  those  inside  from  changes  of 
leniperntiire  due  to  vurreniJt  of  air  nnd  the  like ;  and  the  middle  one  enclonn  an 
air  space  bvlweeo  Itaelf  and  the  inner  one.  'Iliere  are  niiccial  arrangements  for 
clnsitig  the  cylinder*  after  Ihe  inir-.^luctlon  of  the  animal,  and  for  supplying  (be 
animal  trilh  air  for  breathing  purpoHea.  With  the  ali-jscket.  or  space  between 
the  iiinef  or  middle  cylindcnt,  are  connected  a  manometer  and  a  tbennoDKittr, 
Wlien  an  animal  lor  other  source  of  hi-at)  ia  placed  in  the  inner  cylinder,  the 
tempcratunr  and  the  pmuiirc  of  the  air  in  tlie  air-jacket  are  increased ;  aud  from 
the  iimounb  of  Increase  measured  by  the  thermometer  and  tbe  maanmeter  the 
amuaiit  of  beat  given  ont  from  the  animal  is  calcuUted. 

The  calurtBHem  of  D'Arwrnval  and  Kuhner  are  constructed  on  very  nimilar 
principhw. 


64U 


XUTRITION', 


Vurtuue  attempb  bavo  been  made  to  ascerlaiu  ihe  aninuot  of  bni  pm 
I'Ut  by  tlic  body  in  an  indirect  mnnner.  na  for  iostAnoe  by  cnliniUliaf  iV 
h«iU  ^ven  out  by  the  oxidation  of  the  food.  Aa  iniitn'ortlty  luaajvi^ 
|)tiui  of  einiply  BubtraclioR  tlie  norniEl  duily  mecliaoioil  exprnidilun  ki» 
ilie  normnl  daily  income.  Thus,  150,(>00  kiloKranimc-nieirM  MibtfiQnl 
from  one  million  kilogramnie-uieir««  i;pvest(aO.<IOI)  kilogramruc-nMnBHll* 
daily  espcHditur«  in  ihe  form  of  beat ;  L  e.,  Iwtwn-ii  [>iii.-finb  and  <->ii<  ' 
of  tlie  tola!  income  iM;x)>endeilaa  mecbanieal  labor,  tbe  rcmainin):  rii:r  : 
(ir  llve-aistbs  leaving  iIil-  liody  in  the  form  of  lieau  The  results  ^t«ii  bj 
direct  cal«riinelric  oWrvnlions  and  by  otlter  nilculatioos  gire  sonrnhK 
higher  fi^ret  llian  t\>inM> ;  aiid  iiKlecd  tke«(<  may  probably  he  taken  aj  imilcr 
ruber  than  over  tUa  true  iimounl.  In  any  CMO  they  are  to  be  rcfaidal  « 
fumixhiiig  nothing  mure  ihnii  a  roufth  ftv«niee.  the  esiict  amount  *umt 
according  (■>  tbt*  inte.  the  weight,  and  the  ooii<ntioD  of  the  individual,  uVrS 
as  ncennliDK  to  varintiims  in  cin-iimotunouf^ 

$630.  T/tf  inmjy  of  nn-chnnimt  wrh  We  bn»e  already  in  irealin^  </ 
luUBele  and  clM-wh<<rv  [Mirtly  dtMUWcd  this  subject,  btit  may  here  ay  UiMot 
that  baa  to  be  #aid. 

The  older  writers,  even  aAcr  tt  hnd  been  proved  that  the  animal  bnlym 
OODBlmotive,  as  far  as  the  formation  of  (iit  wns  coneerued.  still  belli  lo  tbt 
dlftineliun  between  tulrogvnous  or  plosiic  and  non-nit ro^uoua  or  ittyinWt 
food.    I'ut  broadly,  this  view  was  that  all  the  nitrogenoua  food  wuoi  to  hiil^ 
up  tli«  proleid  tissnea,  the  muscular  fleah  and  tbe  like,  and  tliat  lhaiiirv 
gciioiiA  ege^ta  arcae  solely  from  llio  functional  metabolisni  of  iIhk  tlMMi. 
while  the  noD -nitrogenous  food  was  used  with  e<{ual  exclutiveti«M  Ibrrajaifr 
lory  or  caluritic  [lurposes.  being  either  directly  oxidiued  in  ibe  bhwd  ur.if 
prcaoui  ID  excen,  itured  up  a»  fatty  tissue.     According  to  this  vivw  iht  t<<> 
cImnb  of  Income  curreEjwnded  exactly  to  the  two  formx  nf  expendilDt^ 
We  have  already  UTV^•*i  w^vvrnl  objections  agaiuHt  ibis  view.     W«  have«ai 
thai  in  tbc  blood  itsi-tf  vcrv  litlli-  nxidutina  lake^  place ;  that  it  is  the  Mbn 
tissue,  and  not  tbc  ptis:<ive  ^loixl-plnmiin,  which  ia  the  itcat  of  oxidation.    \Y« 
have  further  seen  tkiil  pn>icid  fiKnl  may  undinibledly  b«.  in  tbe  above  aMM| 
respiratory  and  incidciilnlly  give  rise  ii>  the  vuiring-up  of  fat.     One  divUsa 
of  the  view  is  thcrt-by  overtTirowti.     We  have  now  to  inquire  whether  tht 
other  division  holds  good,  whether  niusetc  and  tbe  other  proleid  tbau«  ar« 
fed  exclusively  on   the  protcid    tnulerial  of   fuoil.  Hnd  whether  miiMular 
enerfcy  cornea  exclusively  from  tbe  nictaboli»in  of  Ibe  proteid  coualitiientf  of 
mujiet'e.     We  have  already  seen  CS  6^)  that  when  the  muscle  itself  a  oxan- 
ined.  we  find  no  proof  of  nitrogenous  waste,  bnl.  on  the  other  baud,  dear 
evidence  of  the  production  of  non  ntlrogvnous  botlies,  such  as  carl>»nir  acid. 
And  when  we  oak  the  question,  Docs  uiusctilnr  vxercise  pro|j»rt)i>tMii«Jj 
Incieue  tbe  urea  given  off  by  ibe  body  as  a  w  hole  T  for  this,  act'urding  to  tbe 
theory  in  ({Utation  il   certainly  oui;ht  to  do,  the  evidence  we  can  obtain, 
though  somewhat  varying-,  i^'ivee  on  the  whole  a  <lende4lly  negative  answer. 

In  tbe  majority  of  observations  no  marked  L-bniige  at  all  in  the  mnount 
wns  met  with  :  indeed,  in  M>Rie  cases  there  was  a  di^inei  decmuo.  followed 
by  an  increoM*  on  thi.-  following  daya.  Some  obserreni.  howt^ver.  fuui>d  a 
Tcrv  niurknl  iiicrea»e.  and  lliia  was  eepecially  Ihe  ruae  whi-n  ibc  subject 
under  oliwrvntion  took  a  lari;e  amount  of  food  and  uerformnl  very  severe 
labor.  0:i  tin-  whole,  the  vailou^  re»ulta  obtained  bv  difforeol  obeerven 
justify  the  cunrltiftiin  that  cxcn'iae  by  itself,  even  when  severe,  doee  doI 
necessarily  increa*e  thf  amount  uf  urea  excreted,  but  that  conditions  tur 
obtain  in  which  such  an  increife  undeniably  occurs.  Wo  may  draw  the 
further  cundunion  that  ex|ieriineuln  i>f  lbi»  kind  do  not  supply  the  riiffat 
method  fur  detemiiniiig  the  point  at  ivsue.    It  must  l>e  rememb^«d  thai  it 


E    KNEROT    OP   THE    B0D1 


th*  nntclM  done  which  feel  ibe  iiifliinicdniio  1«I»ir;  Uw  dKulition 
iadm)  the  wbol«  boily  are  utli^cted  by  it.  li'  wo  au|)poM«hu)[t  part 
'  or  even  onlv  some  port  uf  the  urm  li>  wmv  rnim  oth«r  than  miiiK-uIur  mttti- 
bolUni,  froiD  cluuivei  in  the  he[>iilic  ccIIh  for  iiistnncf,  we  ihoulil  cxprct  ihnt 
thnv  cbanceii.  aii^  nilh  them  the  amoiiiil  uf  uix-o  <)i»chorgol,  would  bo 
inl)u«Oc«l  by  labor,  nupccinlly  by  severe  labnr. 

In  no  csw  hu  ■  direct  relnti'iii  Wlnti-ii  lli«  amount  uf  labor  anil  iini'xint 
of  urea  been  olvervotl.  More  thiin  lhi».  the  follflwing  <ixp<Ticncc  lumln  us 
io  an  ah«uriltty.  if  we  KupjioM-  the  whole  energy  of  muscular  work  to  iirisc 
(nmt  pnitei'l  nie(a helium.  Two  obM-n'cn  iwiformrd  n  ccnuin  amount  of 
work  (an  aM-etit  of  ii  mouiiiain)  on  a  noii> nitrogenous  diet,  ami  estimntml 
the  amoont  of  urea  uossed  during  the  period.  AsMumin^  the  urcn  to  repre- 
•fnt  tilt  oiiclaiion  ofao  much  protcid  matter,  which  oxidation  represcaited 
in  turn  ao  much  energy  set  frve,  they  found  that,  whereas  the  actual  work 
dona  amounted  to  riit.026  and  14S.6o6  kilogramme-kilometres  for  each 
oWrrer  renpeclirety,  Ibe  total  energy  availahlo  from  prot«id  meiaholisni 
■luring  the  perio>)  wns  iu  the  cose  of  the  tirsc  (tK.flO,  and  of  the  second  68.376 
kilogram nc-kilometrce.  Thnt  is  to  say,  the  energy  set  free  by  the  protrid 
metabolism  of  the  musclea  engaged  in  the  work  was  far  less  llmii  the  amount 
neceMnry  to  accomplish  the  work  actually  done,  to  say  nothing  of  its  having 
In  provide  as  well  for  the  movements  uf  respiration  aa<l  cin'ulation.  Their 
mivcular  energy  therefore  must  have  had  other  sotiTcea  than  proteid  meia- 
boliFto. 

Tb«toa  the  contrary  the  praduciiimof  t-arbouioacid  is  at  once  and  largely 
incKMed  by  muscular  exercise  is  beyond  all  doubt.  One  hour's  hani  labor 
will  ineroH  RvefWld  Ifae  ijuantity  of  carbonic  acid  ^ven  oiruitliiu  Uiu  hour. 
Aud  in  an  experiment  direeud  to  tliis  point  ii  wast  found  that  u  man  in 
twenty-four  hours  coiifturoed  9^A  graiunini  oxygen  and  produc«il  ]2Ai 
gnnmt*  rarbonic  acid  when  doing  work.  »»  aguinai  708  graiutuea  oxygen 
cDiUUmeil  and  01 1  grammi-M  curbouic  acid  pn^liicetl  when  reinaiuiug  at  rtat, 
Uia  iiuamiiy  of  urea  fccretcd  being  in  the  lirst  case  HI  grammes,  in  the 
•Mond  37  .'J!  grammes. 

It  is  erident  that  Ibe  conclunDns  arrived  at  by  the  statistical  method 
tntirely  corroborate  those  gained  hv  an  examination  of  muscle  itself,  vi^.. 
that  during  muscular  contraction  ikc  explosive  decompositJon  which  lakes 
place  bMis  chiefly,  if  not  eicluRively,  on  the  nou-uilrogcnous  oonstiiuenta  of 
the  muscle,  and  ibat  it  b  ibc  non-niinogenoua  products  which  alone  escape 
from  the  muscle  and  from  the  biidy,  any  nitrogenous  products  irhich  result 
being  retaiueil  within  the  muscle,  or  at  least  within  the  body.  We  muU 
tbcnfore  reject  the  secoml  &»  nell  aa  the  Gret  division  of  the  views  under 
dbcnwlon :  not  only  in  the  mt]»cle  not  f<d  exclusively  on  proteid  material, 
but  ftko  iu  energy  does  nut  arise  from  an  exclusively  proieid  metabolism. 


I 


Animat  Heal. 

I  SSL  The  (oiirvfs  nntl  diglrilnUiou  of  heal.  We  hare  iilremly  (ten  that 
tht  conception  of  the  non-nilrucenous  portions  of  food  being  solely  calorifa- 
dent  or  respiratory  proves  to  oe  unfounded  when  wo  attempt  to  trwoo  tlie 
hiatory  of  tlie  food  on  ils  way  through  the  body.  The  same  Wew  is  still 
more  Mrikiiigly  shown  to  be  inade((uale  when  we  study  tbe  manner  in  which 
the  bnit  of  Uie  body  is  produced.  We  may,  indeed,  at  once  affirm  that  the 
hut  of  the  body  is  generated  by  the  cbemioal  ofaangee,  which  we  may  speak 
of  gmemlly  as  thoae  of  oxidaitoii,  undergooe  not  by  any  pariicuutr  snb- 
atancM,  but  by  the  tissue*  at  large.  Wherever  nwiaholisnt  is  going  on,  or  to 
b*  more  exact  whetcvej  de^ruclive  metabolism,  kataboliun,  is  going  on, 

41 


642 


XfTRlTlOX, 


lieat  is  b^iifc  set  free.  In  growth  and  in  repiiir.  in  ihe  depumiinn  of  an 
timu-fiul.  ill  ibe  iratiEliiriiuliuii  of  lifelese  piil>iiluin  iuto  living'  (i«^u<>,  in  tke 
coiiMmclive  tiiecab'itisiii,  the  itnalwlism  of  tlie  liodj'.  and  in  the  sRuiller  trs- 
ilietic  pniceffiefl  »f  which  we  spoke  in  denliuj;  with  urea  O  -1D0^  bmt  ■ 
undoubteiily  lu  II  certain  extent  beinx  »1»urbed  and  rendered  Uteui:  ibe 
I'litrfcy  or  llie  i'<jn9iruclioii  umy  be,  in  |>ari  at  Icilm,  supplied  by  (he  lieot 
pn3H.-iil.  But  all  this,  anil  nutre  than  lliis,  vit..  the  heat  {>r(«eiit  in  a  jioten- 
tiiil  form  in  thi;  niibnlanL-Mi  thetoHelvai  so  built  up  into  the  iLvue.  is  lutt  to  iJw 
liacue  during  iu  deAlruvtive  metaboliizn ;  au  thai  the  whole  inetabolbin,  Uie 
nhol«  cycle  vf  cliaugca  from  tlie  UIUcm  piibultiin  ibrou^di  thi?  living  lime 
bocj;  to  tlif  lifelew  jmidiicta  of  vital  arlimi.  \»  eniinetilly  n  WMirc-v  of  Urst. 

Ofitll  the  tiMuvit  i>f  ihv  IxmIj'  th''  niuiti-list,  mil  only  fniin  tlieir  bulk,  I'uria- 
iii);  III  iht'y  du  to  Inrgo  II  |M)rlic)ii  iif  the  whol«  frame,  but  alit»  fmni  ihc 
chnnii'icni  of  their  ineiiilxdixni,  niu.nt  be  roganU-d  iii>  the  chief  lunircvs  of  bnt. 

In  tfx-nling  (^  '!$)  of  tlio  Ihi-rninl  chnngiv  in  miivclc  wc  huvr  )n?*mi  ih.ii  ia 
the  tulnl  rncrgy  CX|H-n'lcd  in  ii  miiwiilur  cimtmetion,  ibi-  ratio  of  thnt  whiefa 
ap|)C«r«  ii»  hcHi  (o  tlmt  nhich  npi>cnr>  n»  rxlemni  work  '»  variable.  If 
wc  take  a  pro]>onion  which  !■  sonicwhat  higher  than  the  nx-an  of  tlia 
ratigL>  there  given  (unc-tidh  to  onf-lwcnty-lifth),  and  nunimc  that  tlw 
energy  inrolved  in  the  work  iloiio  in  a  muMuLar  controctiiHi  is  almat 
one-tenth  of  the  total  energy  expended,  the  mt  going  out  lu  heat,  tfaeti. 
Upon  the  cnleiilation  that  iW  tulal  cstenial  work  of  the  body  is  about 
oue-fiflh  of  the  total  energy  twt  free  in  the  body,  it  is  clear  ihat  tlw 
heat  given  out  by  the  muscles,  even  if  we  consider  only  the  liesi  fEiveo 
out  when  they  are  contmcting.  niusl  form  n  very  large  part  of  the  toUl 
beat  given  out  by  the  body.  And  even  if.  as  recent  researcbee  indicate,  ibe 
musculiir  inaebinc  works  more  econoniiciilly  than  we  have  hitherto  aunpuaed, 
the  aniouiil  of  heal  ^-iven  out  by  the  sketeial  n)UM-le«  must  stjil  remain  wry 
Uice.  Moreover,  to  die  skeletal  ruusele  we  mum  add  the  heart  nbieb.  nevar 
re£ng,  du^  in  the  ivrenty-four  houn  a»  we  ba\-e  mi-n,  ^  1118,  nu  incoiuId«r- 
•bleamotint  of  work,  and  must  ^ive  riie  to  no  inconsiderable  nmouut  of  heat. 
But  the  xkelotal  musoltn,  though  frtHjuently,  are  not  conliuunlly  contracting : 
tlicy  have  period*,  at  timea  long  jieriodii,  of  tchI;  and  duriu);  thesv  portoda 
of  rvM,  luelabolism,  of  n  auhdiied  kind  it  is  true,  bitt  Hill  a  nii.-tiibolrsia 
involving  an  cx|MMi<lituri.'  of  energy,  it  going  on.  This  iiuieaccnt  metalwlism 
must  iilso  give  nse  to  a  certain  amount  of  lieat :  and  if  w«  add  lhi»  amount, 
vfaicb  in  UK  prcsetit  i>iale  of  our  knon-1edg«  we  cannot  exactly  gauge,  to 
that  given  out  iluring  the  movcnienli'  of  ibc  body,  it  is  very  clear,  even  in 
tbe  absence  nf  exact  data,  thnt  (be  nietabolistn  of  ibe  mtiacUw  niiist  siipplT 
a  very  large  proportion  of  the  total  heat  of  the  bwly.  Tlrey  are  [wr  exc«i- 
tenoo  lb«  Uicrmogeuic  tiasuc«. 

Next  to  the  musclea  in  iinportance  oome  the  various  eecretiug  glonda. 
Id  these  the  secreting  elements,  at  the  periods  of  secfettoo  at  all  eveoia.  are 
in  a  alate  of  metabolic  activity,  which  activity  aa  eleewhere  maM  give  riae  to 
bent.  In  the  case  of  the  salivary  gland  of  the  dog  tbe  temperature  of  tbs 
saliva  seerole<l  dunng  stimulation  of  the  chorda,  noa  been  lound  to  tiv  aa 
much  as  1'  or  1.5°  higher  ihan  that  of  the  blood  in  the  carotid  artery  at  ilie 
aiime  time,  and  in  all  probability  the  invteligation  of  other  aecrelin^  glands 
would  lead  to  -imtlar  results.  Of  all  ibeae  varioua  glunds.  tbe  lii-er  deaervca 
special  attention  ou  account  of  its  sice  and  large  supply  of  blood,  and 
becauM  it  api>eaR>  t<i  be  contiunutly  at  work.  If  Uiere  lie  any  truth  in  the 
vieiTB  urged  in  ilie  preceding  cliaiiter  touching  the  large  uud  varied  metahuUc 
work  of  tlie  liver,  we  niurt  eunclude  tliai  a  vfirv  large  an>ount  nf  haal  ia  ant 
&ee  in  this  oi^gaii :  and  thnt  holds  good  even  if  we  make  a  large  altuwano* 
for  llie  variou*  aynthvlic  anabolic  ]>rocea<ct  which  may  lake  place  aiul  ti^ 


vbirli  bm  nriuld  b*  nhMrb<^l  nod  made  luieoi.  We  And.  indeed,  tbiit  tbe 
blood  ill  ibr  hirjnlir  vrin  ii>  the-  niirtiMwt  in  ibe  iKidv.  Thiin  in  ihe  dig  n 
ymmrmlnn'  of  A').'^"  V..  hii>  licvii  iih*i-rvc<i  id  cbu  beimtic  vvin.  nbilr  that 
of  UN  vroa  oith  iiilV-fior  km  :W.:U*  tu  Ilfl^S",  nud  rlint  "f  tbe  riybt  b.-nrt 
S7.7*  Thr  furl  Ihnl  ibv  binod  of  the  he|iatic  \-vin  in  niirin<-r  thiiu  ihnt  of 
rilbrr  tbe  (lortal  vein  or  thr  iMTta,  nbown  ibul  the  iiicniiniil  (tmjK'raiiin'  t« 
Dtil  (lur  riinpl^r  to  thv  livrr  being  fur  reniovtNl  from  llie  xirfHCci  of  (bt^  bodr. 
11ie  brain,  too.  niay  be  reg«ra«d  m  n  lource  of  beat,  siiiec  lis  tcinperamra 
b  bifH'T  tlwn  tbnl  of  the  nrterial  blutid  witb  wliich  it  is  supplied  :  Iboiigh 
front  tbe  amnlter  <|iinntity  of  bloott  piiMing  tbnnigh  it*  vntsols,  m  well  lU 
fWim  tbe  obangtt  i"  it  being  lt»  iDMeire.  it  cnniii>l.  in  this  respect,  cuiupare 
with  eitber  tbe  liver  or  tbe  mtifcWaa  ■  source  of  bcut  to  tbe  body. 

Th«  blood  itself  ean&oi  be  negardod  M&Houroo of  niiy  t^nsidernble  amount 
of  h(«t,  rinoe,  sa  we  bave  so  TrequeDtly  urged,  tbe  oxidiilions  or  other  niels- 
bolir  rhan;^  mkiug  plaee  iu  it  are  comp-iratit'ely  sligbt.  The  h«al  evolved 
ibe  iodlHerent  limuee,  such  ns  bone,  cnriilage  and  coniiective  tisfue.  may 
[unwd  over  a«  inf^ijinificnDt  i  and  we  cannot  even  reganl  the  adi|tQse 
ue  as  a  seat  uf  ibe  produttion  of  beat,  since  tbe  fat  of  ine  tut  eellB  h  in 
all  pmbabitity  noi  oiidiied  in  lilu.  but  eimply  carried  away  froin  its  place 
Kfuon^  to  tbe  iiwue  wbicb  siaiid^  in  need  of  it,  and  it  ia  in  the  lidaue  thai 
it  undtrgoes  th«  metabolistu  by  which  iia  lateoi  energy  is  set  free.  Suiuc 
atngiint  Afbeat  is  alao  prtxluced  bv  the  changtH  which  the  food  uoderfcucx  Ln 
Ibv  alimmtar^'  canal  before  il  really  enlen  the  body. 

HcDoe,  taking  ii  Mrrey  of  the  whole  bxily,  we  may  oonclude  that  since 
metaboiboi  is  going  un  to  a  greal<^  or  lea«  exteiil  ererywbere,  beat  is  erery- 
wbtr*  being  generated ;  hut  thai,  looked  at  from  a  qua  nt  its  live  jHtinl  of  view, 
Um  ma>cW  and  the  trlandular  organs  must  be  regardeil  an  tbe  maiu  fouron 
of  the  heat  of  the  Imdy.  tbe  muwlest  being,  in  all  probability,  the  more  impor- 
but  nf  the  two. 

i  ASS.  Hut  Im-hi,  while  1>cin^  tbii»  continually  produeod,  is  on  oniinually 
bnng  luM,  by  the  skin,  the  bing«,  tbe  urine  and  the  fcoea.  The  blood  pass- 
ing from  ODB  part  of  tbe  body  lo  tbe  otbrr.  and  carrying  nnnnth  fnim  the 
limiei  where  tienl  Is  Iwing  rapt<llr  generated,  to  the  tifsucs  or  iirgan* "where 
b<«t  is  being  lost  by  radiation,  conduction  or  evapiinition.  tend;  (u  eruialixe 
llie  i(!iii)>eralur«  of  the  various  parts,  and  thus  maiiitain)>  n  "eonHtanl.  tiudily 
temperature." 

Wbeu  tbe  production  of  beat  is  not  great  lu  compared  witb  Ibe  luiti  there 
is  no  itieat  accumutsiion  of  heal  within  tbe  body,  tlie  temperature  of  which 
caiise(]iieui1y  i^  but  slightly  raised  abuve  that  of  surrounding  objects.  Thus 
the  temperature  of  the  frog,  for  instance,  is  rarely  more  than  0.04'  to  0.05' 
above  that  of  ilie  atmosphere,  though  iu  the  hreeditig  seasou  tbe  dilTereuce 
mav  anwunt  to  X".  !^uch  animaU.  and  tbi>y  cuaipriae  all  claasM  except  binls 
ao<)  mammals,  are  sfMiken  of  as  i:old-b|iii)d<M] ;  ihey  bave  beeai  aUu  i-nlled 
poikitulhermic,  ttint  in,  of  varied  tempernlure.  Ksce|rtioiis  among  them  are 
DDt  nnrummtin.  H<ime  diAt.  such  tu  the  iiiiiny.  are  warmer,  than  the  water 
(n  which  tliey  live,  and  in  u  «pcci»  of  pylbun  (/*.  bii'lUcilut)  a  diffcrotice  of 


as  much  as  12'  ban  li«-u  ohwrvi^l.     In  a  Iteebive  iltc  temiwmtnrv  may  rise 

at  til 

and 


tc  temiwr 
at  tin»»  as  nmcb  tf  u<  Ait'.    In  the  so-called  wano-blondcd  animals,  bird* 


mamniaU.  the  ton  and  jiroiluction  of  brat  are  *o  balanced  that  tbe  leni- 
peniun?  of  the  body  n-mnins  constant  at.  in  round  numliers.  $5^  or  40^, 
wliatovrr  Im- I  be  teinperattire  oflbaair:  hence  ibiwv  have  l>een  called  bomoio- 
Uteroic,  of  i-onMant  leinperalurc.  Tbe  temperature  of  man  ii  about  37^; 
is  anme  bink  il  is  as  hign  as  44^  (Hirundo),  and  in  tbe  wolf  it  it  Mid  to  be 
aelowM3&/J4'. 

This  Unperaiure  it  with  slii,dit  vnnations  maintained  tbroughont  life. 


644 


XfTBITIOX. 


After  deftih  tbe  generation  of  he&t  rapiilly  diiuiiiivhtv,  anrl  tb»  body  PpMililT 
becomes  cold ;  but  for  twine  *hurl  lime  iitirDedintcly  following  u[Min  vvilcmir 
deatb,  n  riae  of  leiuperuliire  may  l>o  obxcrvol,  due  to  the  fact,  that  while  th* 
■uetftboliKm  uf  ibeiiwue  U  huII  ^iiifc  on,  ibe  Ium  of  beat  i«  *oiDewbat  checlit<d 
by  the  cvitsaiioti  of  tbe  vircubilfon.  Thi^  onjH^t  nf  prououiicnl  ligor  mortl* 
cautcs  u  luurkeil  accuviiiii  of  heat,  mid  when  uccumiig  utttr  certain  dimKs 
ninv  ^ivc  riw  to  a  very  toiwiili-riiljle  clcvntion  of  temperature. 

tins  iiiviui  biiihlv  [(.■miHTutii rt-  uf  niirm-bloodod  animals  »,  Jurine  health, 
miiintaiiK-d,  witli  iilit;hi  vnrimionit  of  whicli  we  ahnlt  I'rtfeiitly  sjwaE.  withio 
a  vc^-  narrow  imirgiu,  n  risr,  or  indcod  n  fall  of  much  more  than  a  d«grM 
above  or  below  the  limil  given  above  bein^'  indicative  of  some  failure  in  (he 
organism,  or  of  sotoe  unutuitl  intlueiice  being  lU  work.  It  is  evident,  lliere- 
fore,  that  the  oiechtiDisms  which  coordioatc  the  lo6»  with  the  prudnctioa  of 
heat  must  be  exceedingly  senailive.  ll  i^  obvious,  moreover,  lliat  the  mecb- 
ftniaiDS  mRV  net  when  the  bodily  teniiRTitmre  i«  icndinf;  to  Hm.  bv  eitlier 
checkioR  tbe  produotioD  or  by  Buj^meniing  the  loM  of  beat,  ooiiveraefy  when 
the  bodily  temperature  is  Ifoding  to  &U,  tbey  may  act  by  elllier  iuef«a*ing 
the  production  or  by  diniiniflhing  the  losa  of  beat.  As  tbe  re;(ulatian  of  tem- 
perature by  varialioDfi  iii  the  loss  of  heal  is  better  knoirn  tliau  rej^ulation  by 
variatiouB  in  prodnctiuu,  it  will  be  beat  to  coofiider  tbein  first. 

g  533.  Hegutalitiu  %  mrtalion*  in  liM:  Heat  ia  loaa  to  the  body,  by  the 
n-armiii^c  of  tbe  feces  and  uf  the  urine,  by  llie  warmiogof  the  expired  atr,  by 
the  I- VII pi) rat iun  of  the  water  uf  ret* pi  ration,  by  euuduction  aiid  nuliati^tu  fnxn 
the  ^kin,  and  by  the  evajMirntiun  of  tbe  water  of  perspiration.  It  liax  hoon 
calnilali-il  that  the  relative  umouutii  of  the  loss  by  thewMwral  chnniiel*  arc 
a»  f'lllow*:  1)1  warming  the  fecea  and  urine  about  3,  or,  iicomliiig  in  oUmis, 
6  per  cent.  By  resjiiration  about  20,  or,  iiecording  lo  other*,  nlM>ul  ooIt  ft 
per  eenl,,  le/iviiig  TT,  or  allcnialively  85,  per  cent.  For  conduction  and  nulb- 
tion  sod  evaporation  by  (hcekin. 

The  two  cnief  means  of  lose  then,  which  are  nt  all  susi'eptable  of  auy  grtai 
amount  of  variations,  and  which  can  be  used  to  regulate  the  tein{)«.'raiun'  of 
the  body,  are  the  skin  and  the  lungv. 

The  more  air  pnues  in  and  out  of  the  lungs  in  a  given  time,  the  grenUir 
will  be  the  Iob«  in  vifinuing  the  expired  air.  and  in  ovaporuiog  the  mtier  of 
retplration.  In  »iich  aniiunk  as  the  doj;,  which  i|o  not  perspire  freely  by  tbe 
skin,  respiration  is  a  most  important  means  of  re^oilaliog  the  teni|>emiiin.-; 
and  in  the  dog  a  very  close  couoeeiioii  may  be  observed  lielu-eeu  the  pnxluu- 
tlou  of  heat  and  respiratory  activity.  Tbe  ohangea  wbieli  give  rise  m  this 
loM  tak<9  place  before  the  inspired  air  reaches  tlie  pulmonary  alveoli ;  both 
ibe  narniing  and  the  evapurattou  are  ellected  in  the  nasal  and  pharyngeal, 
and  to  some  extent  in  the  hruiicliial  paa^tagiw.  Some  olMerven  liave  main- 
tained that  the  li-fl  :«ide  of  the  heart  is  warmer  than  the  riffht,  and  hence 
have  argued  llial  diemical  chaiigen  leailing  to  a  t^onuderable  derelopaiait  of 
heal  tak(«  place  in  th<-  pulmoitary  capiltiirir*.  It  would  appear,  tiovrever, 
ihni  the  righl  vcniriclc,  owing  to  it*  lying  nearer  to  ibo  Hvcr,  the  high  t«D- 
peiiiture  of  which  has  already  been  mi-nlioncil,  i»,  in  rejilily,  rather  hotter 
thnn  the  W-H.  And.  indeed,  we  have  no  «!  I  in  factory  evidence  of  nuy  lar^ 
amount  of  heat  being  produced  by  any  niilriKinary  nieliibolieni. 

The  great  regulator,  however,  is  iindoiibK'dlv  the  skin;  and  tbis  has  a 
mora  or  leas  double  action.  In  the  lir^  plnec,  it  rv-gulates  the  loea  of  heat 
by  ueaDB  of  the  vasomotor  mechanism.  The  more  blood  posses  through 
tM  skio,  the  greater  will  be  the  loss  of  bent  by  conduelimi,  radialiou,  and 
evajMiration,  Hence  any  action  of  the  vasomotor  mechanism  which,  by 
catuiiig  flilution  of  the  cutaneous  vascular  are8«,  leads  to  a  larger  flow  of 
btoo<)  through  the  skin,  will  lend  to  cool  the  body;  a  ud,  conversely,  any 


* 
* 


I 


iinouir  Mtlnn  whk'h.  Iiy  coiutrictliiK  t)i<-  oulnDcouit  vtuMiulsr  nmia.  or  by 
iMlilhis  the  uplmiclinit-  vascular  ftrau,  cnuM*  n  «niaUi>r  flow  ihmueli  ihe  tkiD. 
ud  KMrf^r  nowof  IiUmhI  t)ir»iigbthe  nbdominal  viM'ern,  irill  t«na  tohcMlh* 
bodjr.  In  itir  Accxiil  pturt-,  t>^i<lai  this),  the  xpcrial  nerve*  of  nerapiratton 
will  Hrt  'lirTCtl)-  U  reeulBlor*  of  tprnpt-riiliirp.  inrrmning  (be  lo»  of  hcftt 
wbrn  tt)i-y  momiote,  ano  liMCninK  (he  l«««  nhcii  thry  caw  to  promoM,  tb» 
HCfMioa  01  llie  i>kin,  Thr  worlttnif  of  M*  hrnt-n-^iUting  mochnnwcu  ia 
vtll  tMm  in  llw  ciu^  nf  cxorrifc.  i-inw  i-vrn-  miiHcnbir  conlrnctinn  giv«* 
rfa*  W  hi-nt,  Mcrrin-  nm«l  incrcnM'  for  iHp  tinir  (K-ing  (be  prmliKMion  of  hf«t ; 
JH  the  li-xlilj'  tern  thrill  lira  ran-ly  riiKH  no  much  iw  n  degree  cciilii^niili.',  if  iit 
■II.  By  cxrrviM  (h«  re«piniti'in  )•  ouickcneil.  nml  (Iir  low  of  licnt  by  th« 
lung!  iticn-w«H.  Th«  circulalinn  of  liIooH  ir  iiIrq  (|ini.'k<-nei],  tiii<)  the  <;ut«- 
n«<i(i»  voM-uliir  nrcH'>  lKs:oniing  dtlnteil,  ti  lnr);cr  amount  of  blow)  pnmtt 
lhr<Mi];h  lh*>  'kin.  Added  lo  tnt»,  the  skin  pervpim  frcelv.  ThiiH  a  Urge 
UiMfinl  of  heal  is  \tnft  to  the  body,  xutficient  to  neiilriiiii:e  rhe  nddilian 
nuiw«)  by  Ihe  iiiiiscular  eontrAetioo,  the  iacreaw  irhich  the  nioro  rapid  flov 
n(  blood  (hrou(rh  the  abilomtDal  orgniia  niii.'ht  lend  to  briD|>  about  being 
iBoiv  ibau  fiutlieieuily  coiinlerscled  by  their  ftiualler  supply  for  the  lime. 
The  MDM  of  nnrmlh  whit^h  is  felt  during  exercise  in  eonseiincuce  of  ih« 
ItnabinK  of  the  akin.  \».  in  it«>If,  a  token  that  ii  regidalive  eoolitij;  i^  being 
rarricd  on.  In  u  Airoilar  way  (he  applicaliou  of  external  cold  or  beat  ilel^ta 
ib  own  eoda,  either  iiurlially  or  completely.  Under  the  influence  of  external 
mid,  tlK'  culaueoiu  veuel*  ore  eoiiRtncled.  and  the  aplaiielinic  vascular  area* 
dilaiMl,  Ml  that  thi-  blond  !«  wilhdmwu  from  the  colder  and  ctMiliT  rc>;[»iifl  to 
the  hotter  uud  hi-at-pniduciD^  orj^an*.  Tht*  vancular  vbang«  niny  be  used 
to  explain  tlw  fact  that  ntripjiriig  iiiikeil  in  a  <^ld  ntn]cMph<-re  oOen  gtvi-*  rife 
to  a  diiliuct  ini'rcttte  in  th«  mean  ti-inpfmiure  of  the  blnoil,  ai  iiidicatnl  by 
a  tbi-mioni«ler  placed  iu  the  mouth,  th'iu^h  |Hi9»ibly  thi'  cfliyl  mnylw  partly 
doc  to  an  acUial  incrwiBc  of  the  pMdiietion  of  heal.  L'nder  the  uiflueiice  of 
ext«n»l  wartiilh.on  the  other  bund,  the  cutaiieoua  venels  are  rlilatol.a  rapid 
dtachar^re  of  heat  takes  place  -.  and  if  the  circumstances  be  such  that  the  body 
can  pefpire  fre^'ly.  anil  the  perspiration  be  readily  evaporated,  the  temper- 
niurrr  '<{  the  lto<ly  may  remain  very  ticar  to  the  normal. even  in  nn  enccHively 
bot  atmosphere.  Tliu»,  more  than  a  century  a^.  two  obacrver«  were  able  to 
remain  with  impunity  io  u  chamber  heated  even  to  127"  C.  J  'ilSIJ'  Fnhr. ),  and 
with  e««e  in  one  «o  hot.  that  it  tiecame  painful  for  them  to  touch  the  metal 
buttona  of  their  eloihinK.  It  Is  unnecea&ary  to  (five  any  more  eiamulen  of 
ihb  rejiulatton  of  iem|>enilure  by  variaiioos  in  the  Inss  of  beat;  iliey  all 
readitv  esi^aio  ihentM'lrea. 

5  M4.  Tfif  pro'luctiou  of  heat,  ill  varlnlimu  aiid  reyttlaiion,  Ai  we  have 
■Umdy  Mid,  the  eiact  determtiiatiun  of  the  amount  of  heat  produced  in  tl»e 
KTlog  Dody  b  atlen<led  with  grcm  dilficultiiH ;  Mill,  certain  wncluxiimH  have 
Iwen  arrived  at  Imted  partly  uii  cliri-ct  cji In ri metric  n)>M'rvation».  thv  more 
nct-nl  uncD  with  imprnvcd  calorimeters  bcin^  niijeciallr  valuable,  and 
partly  on  what  *«eni  to  be  tnurtworlby  deduclioitt  from  oWn-cd  clieniical 
clungn. 

The  rate  uf  production  nf  heat  in  n  living  biwlv  Ik  dcli-rmincd  by  a  variety 
of  rirciiRi»4ancc«.  Id  the  finit  pla™.  what  may  iic  cjilldl  the  gcnemi  rale  of 
HtetatHdiim.  and  »  of  the  pnxhii-tion  of  heat,  vnricw  in  difTerent  kind-  of  ani- 
mals. Of  two  Rnimai«  of  ihi:'  uiinc  hulk  and  weight  placed  under  the  Miine 
drrnmnanoea,  one  "  live*  fulcr  "  than  the  other,  melabolixcs  lie  living  Hab- 
tlsnoe  more  rapidly,  and  »>  pnxluccs  heal  more  rapidly.  Thus  direct  caloti- 
netric  obaorrationi,  a>  far  at  thev  at  present  go,  show  that  a  man,  on  tlw 
Kvenge,  produces  more  heal,  [«r  kilo,  \vr  hour,  than  doe»  a  dog,  and  a  Aug 
non!  thaD  a  rabbit.     Probably  every  ai^eciea  baa  wliai   may  be  called  ita 


n 


046 


N'fTRlTIOX. 


•pon'ic  corrtiPiFiii,  nrnJ  ovorf  in<liri<tut1  bis  {MTtniinl  co<-tfiri«iil  of  hail-|>n>- 
auction,  the  r<i'tHdrni  hvlag  Ihv  expn-^iim  of  the  inl>om  (|UBliti«c  proper  lu 
the  living  futisOncc  of  th«  f|>pci««  imd  of  lli«  individual. 

A  litrger  livioe  body  nitl  amnnillr  produce  inor«  h«nt  thnn  n  ainallw 
living  Iwdy  of  ihe  Mine  nature,  Hince  t)ie  larf^r  Ixxly  poaaeeae*.  to  to 
epeak,  >  gr«alor  number  of  beat- prod ucinj^  unit«.  Bui  iliis  is  DMiltmlitfd  bjr 
Ml  oppodng  teudcncy.  The  smaller  body,  liavioK  relatively  to  its  bulk  a 
larger  amount  of  surface,  loses  heat  at  a  niorv  ramd  rati?  iliau  dues  tlie  larger 
body :  Slid,  therefore,  to  maiDtain  the  balance  t>etwe«a  loss  and  produclixa. 
■0  as  to  secure  the  iranie  cousinnt  bodily  leiaperature  'and,  as  ve  Imve  jiurt 
seeu,  the  bodily  temperature  of  warm- blooded  animals  is  n-niarkniily  iinifi>nn>, 
it  must  produce  heat,  per  unit  of  its  body,  at  a  more  rapid  niit>.  Ah  a  nil«, 
the  gmt«r  loss  of  lieal  owing  to  the  relatively  greater  nirface  it  no  marked 
llMt  of  two  animals  having  the  same  couatant  iKMJily  t^mperaturv,  of  two 
mcieeof  uammala,  or  of  iwu  iiidividuab  of  the  wim«  race,  weabouhl  4>xpwt 
llie  smaller  one  to  produce  a  rt-latively  larger  ainounl  of  heat.  And  dirwt 
cahiriini-tric  obaervatioDS  shon'  thiit  thU  i»  to.  The  *tniggle  for  f-si«tvnc« 
hat  rained  what  we  liave  ju<t  called  the  specific  or  penKxial  i-ocificiunt  of  Uia 
imallcr  aiiitaal. 

From  what  we  have  »een  conccniiiie  llie  iminodiale  cITccls  of  a  niial.  «a 
•boiild  be  inclined  t»  expect  that  fooa  would  temporarily  increase  tho  pn^ 
duction  of  heat ;  and  not  only  U  this  view  confirmeil  by  common  oxperieoo* 
an^l  by  our  own  acnsiitionf.  but  (lirei.-t  calorimetric  olwcrcatiuRS  »ffam  experi- 
mental proof  of  its  truth.  In  llic  dog  it  hu  hern  found  thai  the  rate  of 
pr>.>duciion  incnaeea  aller  n  meni,  reaching  its  maximum  from  the  sixih  to 
the  ninth  hour,  and  then  iWlining  to  a  level  which  may  l>e  ragarded  as  Uui 
teeured  by  the  general  mcTabolisn)  of  the  body,  and  which  ap|ioaT8  to  be 
maintained  with  remarkable  coniOaucy  until  aller  long  starvation  the 
economy  begins  lu  break  down.  Thua.  in  some  ex[>eriineuts  the  prndiirtion 
at  the  nintli  hour,  after  au  onlinary  meal  of  meat  and  fat,  wa*  at  a  nU* 
about  'JO  or  'I'l  per  cent,  greater  than  that  at  wliich  it  wun  goiiiff  on  before 
food  wa»  given,  and  to  which  it  suhseiiueotly  sank  before  IimhT  was  ajjain 
given.  It  would  ap|>ear  that  if  sugar  Ih;  added  to  the  nwal  the  rise  hctoomat 
more  nnirkett  nt  an  earlier  jicriod,  as  if  (be  economy  found  ^ugnr  raaicr  10 
consume  than  fat.  Thin,  howover,  i«  a  matter  which  as  yet  re<)uln»  lo  b« 
n«ire  fully  workwl  out. 

Labor,  mufculnr  work,  lias  n  powerful  influence  in  incttasing  tlie  tirodtio- 
lion  of  heal.  As  wc  have  seen,  of  the  totjil  heal  produced  iu  the  Body,  a 
certain  portion  must  alwayx  Iw  attributed  to  muK-utar  oontrodicKts,  which 
even  iu  the  most  qiiiei  hoily  arc  always  going  on :  in  au  ordinary  active  body 
a  considerable  •|imntity  of  heat  must  be  thus  gencralnl.  Heiiee,  Ihe  ninr« 
active  the  body  the  greater  the  production  of  li«il.  As  we  slated  before 
( !i  >^T ),  In  a  contraction  the  proportion  of  the  energy  set  free  10  do  work  to 
that  set  free  at  heul  appears  lo  vary  under  diHcreiit  cin-umslances  ;  and  the 
increase  of  heat  due  to  labor  probably  varies  in  a  Gum«|>o«ding  way.  The 
deiails  of  thi»  relation  have  yet  to  be  worked  out,  but  wc  miiy  at  least  con- 
c I II lit- that,  when  a  man  pushes  bis  daily  labor  beyond  the  i.>0,000  kilo- 
gram mc-met  res.  Ihe  additional  energy  thus  leaving  his  bndr  as  work  done  ie 
not  taken  out  of  the  H.50.00U  kilogramme-metres  given  in  ^  o'.^  as  the  average 
daily  output  of  heal,  but  the  total  selling  ttw  of  energy  and  ibc  total  pro- 
duciton  of  heat  is  at  the  aauie  time  iocr«ised.  \aA  it  need  hardly  lie  faid 
tbni  ilir  figures  in  outstion  itive  only  an  average  eettniate  for  a  nian  of 
average  biiml  and  weight,  takiiijf  an  average  amount  of  average  fiKid,  and 
doing  au  average  amount  if  work. 


THK    E.VEROY   OF   THK    BODY.  lUT 

i  539.  Tbc  tiroduniuii  of  beat  ibus  determiueil  by  thtve  M;\*«riil  influeneea, 
t>{  nliicli  are  ihrniitL-lvc?  rei;iil(itctl  b^  tbi-  iitnouB  iiTsti-ni,  U  furtber 
.  _  ^ihiUd  ill  a  r^nmrkalile  maiiiu-r.  Fur  it  i:i  tii>t  wlely  br  viiHiiUon*  in  ibe 
Mttfbeat  ihni  tbt-  <v>iiMant  U-oipc-niture  of  th«  ivurni-liluuilinl  nnimal  U 
amjutaintt].  Vurinlioii!!  in  tbi'  niumiul  of  htuil  ar-lually  jft iifnitnl  io  the 
body  i-oiutiliilf  ail  impnrlitDE  Im-lur,  not  "iilv  in  l\w  muinU'iiiincc  nf  tbt- 
nnnml  lisnjwralun*,  but  aim)  in  llie  )>nid)tctuin  til'  ihf  abiKirmallv  bigh  ur 
luK  iMup«r«liirvii  uf  varioun  (lii>mM^  Many  ii>niiiilcrHlii>nH  bare  fon^  I'tl 
|iby»i<>)iiu;i*U>  to  (iiiitic<-t  lh<'  t'xii>tciico  of  a  iHTvuiiii  incchuiiiini,  by  which 
dhrtnt  itapulmr*  arming  in  thr  nktn  or  clwirlirn-  might,  thnmch  the  eeiilnil 
Mrrrou*  •ymrni.  urigiiiiilr  oDcrctil  impiilnv,  wh'w  rrtV-ct  nimhl  Ik;  to  iDi-mtw 
or  In  iliminivh  the  nK-lab»li«tn  of  the  niiiscW  '>r  oth^r  nrganx,  nni)  tltun  to 
loonMV  nr  •liminish  rbr  iiinount  of  bent  grnvrati^l  f<ir  lb«  lime  bving  in  tlw 
h«lt.  Tho  rxivtenre.  in  fact,  of  a  mfiabcilic  or  thermogenic  tiorvdus 
BM«-lMUi»ni,  oompairabic  in  many  n«]>ectF  In  tho  va«oinoti>r  niccbaniam  »r  to 
thr  various  creating  iiervnns  mechanUms.  fcrnis  in  itwlf  >'  /irhri  prutMble, 
And  tio  bav«  ozperimcnial  eviiteni-e  that  Ruch  a  i»i-chnnism  dots  mlljr 
aiit 

The  viirmbloodcd  animal  is  diBlingiiiali«<]  froiD  the  colH-bluodtxl  anima] 
by  the  fad  that  vheti  it  in  exposed  to  cold  or  heat  it  does  nut,  like  the  latter, 
bccMiie  colder  »r  holier,  as  the  cose  may  bo.  but,  within  ei'rtain  limits, 
BMUoiaina  its  nornial  temjierature.  If  the  maintenance  of  the  temnerature 
of  the  wanii  blooded  aotmul  during  exjKiBiire  to  cold  is  aasiMea  by  an 
iocreved  production  of  beat,  ami  in  uoi  due  »mctly  to  a  diuiiuislied  Urm.  w-e 
ought  lo  fintl  evid«uce  of  an  increased  roetaboliflm  during  tbni  exposure. 
Vr'e  ought  to  find,  under  these  circuBMlaDcet,  an  increased  production  of 
cai-lx>uic  acid  and  au  increased  oonaiimptioD  of  oxygen,  Hince  it  in  ui  these 
pnHliirU,  rather  iliao  to  the  nitrogenous  uctors,  on  tlte  peculuiriliet  of  which 
a*  nnoertain  sign*  of  metabolism  we  have  already  iniustetl,  we  mu»[  louk  fur 
uxlicatioiw  of  the  riw  or  fall  of  mctaliolie  activity.  Of  th«c  two,  tbc  pn> 
duciion  of  curhontc  acid  sn<!  the  consumption  of  oxygen,  the  latter  is  tbc 
tnor«tniportantand  Inislworthy  measure  of  mclaholiam,tv|i<-cinlIy  when  Db»cr- 
vnljons  an-  toade  for  short  period*  only  al  a  ttnic:  fur,  tut  nc  have  nvn  in 
Inaliogof  nvpiration,  the  exit  of  carbonic  ncid  '»  more  ckiMly  dependent 
on  the  acttoo  of  the  respiratory  mechanism  than  is  the  income  of  oxyeeti.aiid 
carbonic  acid  can  be  retainol  in  loow  combinatioo,  and  to  tenipornriiy  stored 
op  by  rarious  constituents  of  the  body. 

Takinjf,  tlwo.  the  consumption  of  oxygen,  and,  though  nilh  le.<e  confidence, 
ibe  production  of  carbonic  acid,  as  a  measure  of  Diclanolic  activity  and  so  uf 
bent-production,  il  has  been  shown  that  a  marked  contrast  in  this  respect 
eztsls  between  oold-bloodetl  and  warm-blooded  animals  exjioeed  to  changes 
of  leraperature.  In  ibe  cold-blood  animal,  cold  diminishes  and  heat  increases 
ihe  metabolic  activity  of  the  body ;  as  the  temperature  lo  which  the  animal 
is  stibjti^'ted  riset  or  falU,  m  the  consumption  of  oxygen  and  production  of 
cmrbonic  acid  is  iucrcAsed  ur  lessened.  The  IxHly  of  a  oold-blooded  animal 
beliavea  in  this  respect  like  a  mixture  of  dead  substances  in  a  cbeiuisi's 
ivton ;  Iwat  iiromoiea  and  cold  retanh  obemical  action  in  l>oth  aises.  V'eiy 
dlffrrent  i*  iiie  liehavior  of  a  warm-blooded  animal.  In  this  ca.'ie.  witbiu  a 
lower  and  a  higher  limit,  cold  increiiMiti  and  beni  diiDinisbw  tl>«  bodily  meia- 
ho)i*ni,  as  shown  by  the  ineri-aiR'<l  or  <liminii>)jei]  eomumplion  of  oxvRtm  and 
pr<»lurtion  of  caiuunic  acid  n>  the  temjierature  falU  or  risett.  lu  tboK! 
animals  itierc  is  obviously  a  mvchanisDi  of  aunie  kind,  counler-acliug.  and 
in<lerd  nveiciming,  (hpso  more  direct  cS!mU  which  alone  ulitain  in  cold* 
bliH^kil  animal*.  And  that  this  mecbitiiba  is  of  a  nen-'im.  natuiv,  U  iiuli* 
catvd  bv  the  following  facts: 


xuthitiox. 


WheD  n  wiiriu-liliKKlod  noininl  it  |>oifii>nec)  br  iirnri.  thi-  teiu|H>niliiiv  fnlU 
ati<l  Ui«  nictabaliem,  iiicosiirc'l  by  llio  consumption  of  uxyi^ii  iinil  ttic  [iro- 
ductHrn  or  urbunic  ncid,  sinks  alsa ;  and  thai  tb^  Inlter  Ji  llie  (.-auite,  not  ihc 
elfecl,  of  the  foraicr  is  ehoivn  by  llie  facl  tbsi  ihe  lueinlxilUni  continiH*  to 
fttll  lhoii(;b  low  of  btrnt  be  ]ir«rente<t  by  surrouiKliiiK  tbe  animalt  witli  wra|>- 
piii)(n  I'l'  i.i>tl>.>n  wool.     In  eucli  a  uranEed  anininl,  exfiosiire  to  liislwr  l«ni- 

Kraturw  imKnionU  and  cxi«iHnro  to  lower  temi)ora»»r»  dlniitiiKbo  meta- 
liiuu;  tbi>  urarix^d  nurm-bloixJcd  animal,  in  laci, WliavM  like  a  ooM-bliMHW 
Miiinal.  Similar,  but  iierbapu  not  Huch  Htribiuj;  or  «i  couMaiit  r»ult»,  are 
gaiii«<)  by  division  i>l'  tlie  ui>^iliil]a  oblon^ita.  Aflor  this  openttioti  tti«  t^m- 
peralurc  of  tbi*  body  ftitikx.  and  the  fall,  tbousb  )>Hrllv  due  lii  inrraawd  lam 
of  heat  by  the  i>kin,  caiiAe>l  Iiv  iht;  dilated  vooditi'm  ul*  Ok  cuUinvQUa  vtMeU, 
i»  nliM)  n<s-i>iiit)HMit<d  by  ilimiiiiHbi'd  nictftboliiini,  aiid  >»,  tb«rclbi«,  io  part  diM 
li>  diminiibcil  |iri<rliK-iion  id'  Kent.  Ami  wben  an  aninu]  b  in  thit  cotuUtinti. 
CxptMnrv  Io  hij^bi-r  [ciniHTiiturv*  incrriiw^  and  exiHifurc  to  Iowit  teinpvni- 
liinx  diniini^hcn  ihv  bnaily  ni<:tnb(di«m.  Wo  can  ncft  explain  iImw  re^lu 
by  wpiMwn^  that,  under  nnrmal  cniidilionR,  tbc  lanjclci,  which  ju  we  lwv« 
Men  conlribuli)  nn  Inr^rvly  to  ihu  totid  heal  of  the  body,  are  placed,  by  ia«Dl 
of  their  tnolt-r  nerve*  and  the  central  nervnns  system,  in  somfl  BjMyiial  coo- 
Dcelioii  with  the  xkin,  ho  that  ■  loweritii'  of  the  temperature  of  the  skin  leadi 
to  an  in(-r<-«i*e,  while  a  heighleninK  of  the  icnineniturc  of  the  skin  lewis  to  ■ 
decrease,  of  ibe  ntuti-uUr  mrtabnliBm.  Furiber.  the  centre  of  this  ibermo- 
laxic  reflex  nicehntii«m  apiteiirs  tu  be  placed  siimewherc  in  tbe  nervous  syvteni 
ab[>ve  ihe  spinal  eonl.  When  iirari  is  i;iven,  the  reflt^x  cliain  ia  broken  ut 
ils  miieculiir  end  ;  when  tbo  spinal  cord  is  dividi'd,  tbe  break  is  nearer  the 
centre.  Whelher  w-e  should  conclude  that  the  working  of  this  reflex 
mediaiiism  is  nf  such  a  kind  that  culd  in  ihe  ekin  excites  the  centre  i<i  a 
beat -producing  activity,  or  of  such  a  kind  thai  warmth  Io  the  skin  inhitnti 
R  prcvioustv  exialin);  autnmittic  activity  nf  ibc  centre,  iniiy  bo  lel\  liir  ili« 
prcMHil  11  nileterm  tiled. 

Wv  may  add,  ihal  the  niii*eulnr  nietaWiam  which  ihun  helpii  lo  Rfulal* 
lemperalurc  iiewl  not  involvu  viiiibli>  mniKiiliir  [imtnicliuns.  Althcaaiuf 
time,  the  heat  jgiven  out  by  the  musclm  will  be  Icnipomrily  iuereasHl  at 
veery  contraclion  which  may  iict'ur.  Thus,  the  shivering  which  fulluwi 
expiffure  lo  cnld  dinlinctl  r  beljM  to  warm  ibe  lindy :  indeed,  e»nir  obwrven 
have  been  led  to  think  llint.  in  man,  this  visible  elfoct  ofoold  iditrs  a  uiiM 
iiujHirtaul  part  in  bis  heat  regubitiun  than  the  invi*ible  actinne  widcb  we  Iwre 
jllM  de>orit>ed.  We  mav  niso  add  that  the  regiilntivc  nervous  mechatitfm 
mav  apparently  be  overborne  by  an  exposure  lo  too  great  heal  or  cold. 
When,  I'lir  iustiuice,  the  cold  lo  which  [he  animal  is  expoeed  becumee  excea- 
>ive,  ibv  reaction  of  the  ihenuotaxic  nervous  sysleu  Ja  powerltw  aKftioH  th» 
direct  nctinn  <iii  ihe  tiuues  of  the  depi'csfiiny  infiuences,  and  tin  metabolism, 
lo^lhvr  with  ibe  li^mperaltire,  lunk^. 

Tite  n'9ult.-<  with  iiniri  Jnsi  mentioned  «eein  t(i  show  that  this  thcmiiriuxic 
ncniun  nit-chanisiii  \imiTs  chiefly  ou  tbe  skeletal  inu»cle4.  Whether  tbe 
glumluhir  orgiin*  take  any  |)airt  in  it.  or  whether  they  have  a  luetakolie 
tbennoiaxic  macbinerr  of  their  <>wu.  nf  such  a  kind,  fur  eiaiuple.  that  the 
increiut'  »f  bent  proiluclion  <lue  to  f'x^l  i*  tbe  remit  not  an  miiHi  of  the 
initnedinte  cuDMiniptiou  nf  ]>nrl  of  the  IiiihI  iiavlf  (luxus  conaumptionj  n^  of 
tbe  i>r«eence  of  fotjd,  in  the  alimiMlUry  canal  or  after  nliMjrption,  etirriujt  Up 
llie  li\-er  lo  increased  nielabolisin,  we  do  not  at  prc«ciit  know. 

S  536.  Id  a  number  of  cxperiinenls  it  Ixw  btwo  sliowa  that  injttrio>  in,  mch 
ni  ihow  oau«ed  by  punoturc  or  galviinie  cauterjr,  or  tkotrical  Mimulaiion  oj' 
limited  poTtioDB  of  the  mure  ceotml  portions  of  tbt  bniin.  mav  give  rise  lo 
n  ^nat  iiicreoae  of  the  temperature  ol  Ibe  bixly  wiihout  prvxlucfng  any  other 


I 


I 


mHcMl  ■jriiiptoRi.  Thr  incmiito  if  shouD  by  tbo  increow  of  nietnb»lisni, 
bcmMtl  pnaliKlkni  of  cnrlwrnk-  ncitl.  mh!  incrfni'cd  (^iii«tim|)linn  nf  oxvpwi. 
m  wtII  a*  dv  dirrct  r»lririin*tric  obBervulimis,  to  Ih'  iIiip  t"  an  incrcatwa  (Wn- 
duction  of  Honl.  This  Dahirnlly  suggv^rii  ihnl  the  [Hjriioits  of  the  brain  tn 
^BOtinn  ronUiD  the  hypolheLiail  fac«t  cctiln' jii»t  nienlioned,  the  ic«ioti  in 
MimulntioD  exdliog  tlie  centre  tn  iictiv-ity  by  direct  nctioo  aii  il.  iiislcsil  of 
IB  the  usual  reflex  maiuier.  The  mnttcr  hue  not,  however, ai*  yel  been  I'Imrly 
worked  wut :  aoil  indeol  obeerrots  are  doI  ii^reed  as  to  Ibe  i-xact  parts  of 
llie  brain  injurr  lo  which,  or  EtimulatioD  of  which,  produces  lite  efleet. 
While  some  place  il  in  the  inediiiD  nnii  boaal  portions  of  the  corpus  Hlriatuio, 
oUicfa  niaiolaiu  that  il  t»  situated  in  the  optic  thalaiuiu.  The  fact,  however, 
remains  that  aa  aAeetiun  uf  a  very  liiiiitt^d  fiorliou  of  ibe  central  nervous 
mten)  may,  without  producing  any  other  obvious  ojlects.  w>  increase  the 
Iwai  priMiuviiou  of  the  body  as  Ut  raise  itie  temperature  uf  the  budy  »e\'eml 
dMTcea. 

1 087.  By  rc^lative  inevbanisoui  of  the  kind  ju^  dijcuwed  the  lemjiera- 
lure  nf  the  warm-blootled  uuimul  h  tnaintiiiuiirniUitD  rvry  narrou'  liinito. 
In  onltnary  bailth  the  temiieratun:^  of  ninii  varia>  bi^tweeu  :J6^  atwl  ^°,  the 
itamxiriT  Jirnibt  Wiiig  :iG.'i5'  aud  -il.-f,  witvii  tbu  therniomnler  in  placed 
ID  the  axilla.  In  ihu  month  the  readinjr  of  the  thvrnto meter  i»  nomfirrbat 
fO.iA''  to  1.4°)  hifthur;  in  the  rvctiim  il  isVtill  bijrh*'r<  about  0.9°)  than  in  tbe 
mouth.  Tho  tcmperaltire  i)f  infantH  and  childn-ii  \»  xligbtly  higher  and 
uueh  nora  Mnoefitlbh;  of  variation  than  lluit  of  adiills,  and  nOff  f<ir[y  tmi* 
of  ago  the  avenge  maximum  iL-miHTaiurc  (of  bi-allbi  i»  mnu'whrn  lower 
tliaa  beAm  thet  e{>ocli.  A  diunial  \'nriation,  iode)ii.-iidrnl  of  food  or  other 
dnuBMUaoea,  ha*  \nvn  olwcrvcd,  thv  maxinmni  ranging  from  9  a.m.  to  6 
fJL  and  the  minimum  from  II  r.M.  t»  3  a.m.  McuHs  cniiw  flomditnw  u 
alight  oteratioR,  tomctinics  a  »ti<;hl  <lcpr«9Hi<>ii,  the  direction  of  the  influvtH.>a 
dvpendiag  on  lh«  nnturcof  the  fowl — alcohol  wkou  always  to  produce  n  fall, 
KxeniM  and  variaiioiu  of  external  temperniure,  within  oi>dtnar>'  Umiia, 
oauae  a  rery  slifcbt  clianp,  on  eeoount  of  the  cofopenMtinK  influences  which 
bare  been  discuawxl  above.  The  rise  from  even  active  exercise  duce  not 
amoant  to  I";  wbeu  labor  ti  carrieil  to  exIuuMtion  a  deprea^iou  u(  lemji^rn- 
lur*  may  be  observed.  In  iravellinK  from  very  ouhl  lo  ver^-  hut  n-ciona  a 
variation  of  lea  than  a  decree  oi-cunt,  and  the  teRi|ieraturo  of  inbabitauls 
at  the  tfopica  if  pnu'iically  the  miw!  us  of  thivu  dnt-Ilintf  in  arctic  rrgimu. 

S  fi38,  Stany  of  the  maladii-ji  <if  the  bixly  are  charucirriMil  by  nn  incmM 
ef  tlta  budily  temperature  known  ax"  fevur"or"  pyrexia,"  ttiv  t  hi- nun  meter 
Terr  ftvquftntly  ruing  to  39*  or  40%  not  unfr^iucJilly  to  4P,  an.i  nl  lime* 
rraching  4^"  or  even  14';  but  thtwe  hiulMT  ii'iii[>cnit(irm  cannot  long  bo 
Inirne  aiihout  the  organtfni  failing.  And,  nn  uc  luiva  nid,  any  imrt-iur  in 
BHin  of  the  boilily  Icmpcmliirc  beyond  3S^.  or  even  hcy-nd  '-iT.-t".  indicate* 
■ooM  disturbance.  In  mo>l  ca*r»  the  rine  of  trni{ieralure  hiu>  a  dclinile 
oltjactive  cnMe,BOino  local  inflammation  or  sup{Hi ration,  or,  n»  in  ijiecilic 
ftvrm,  Ihtt  pmnuco  in  ibe  economy  of  lotne  "  lualeries  niorlH,"  of  iho  nature 
nf  an  ort^niAnl  germ  or  of  wime  other  naturi>.  We  cannot  here  diM.-UBs  the 
oovnrction  lidwwn  local  inHninmation  or  the  specitic  imiimiu  and  the  high 
lani{>criiturc,  but  we  have  iucreaaing  evidence  that  tlie  ui|{h  iem|)eratnrv  of 
fever  is  due,  not  merely  to  n  diminution  of  tike  Itua  of  heal,  though  this  may 
be  a  fiictor,  but  also,  and  indeed  chielly,  to  an  increased  pr»ducii<xi  of  heat. 
In  fev<-r  the  prodiietiou  of  carbonic  acid  and  the  couMimption  of  oxygen, 
tJuil  is  lo  say,  tlie  metabolic  chattel  of  the  tiMuea,  are  incrtuwoil.  The  urea 
also  ia  inereflswl,  ami  that  in  suob  a  way  at  to  nmlirui  the  view  already 
exnraMod  that  niudi  of  the  hint  coniea  from  such  a  mclabolitm  of  the  skele- 
tal muMlca  aa,  unlike  nu  ordinary  contraction,  dirvctiv  involviv  Ibe  iiitro- 


i 


600 


SVTKITIOS, 


getuMs  elenieuU.  The  itiordinnte  in«Uibo)lMii  uf  ihc  Ivalr  nt  Imrxc  ihui 
c-h a nici eristic  of  l^ver  is  slio<ni  by  the  irastin);  which  it  i-nliul«.  (^lorinwUJc 
ohoerrntiooa  also  ahair  in  a  direct  niunner  that  (li«  productioa  of  btai  U 
increased.  Of  <.-our«e,  mere  iocreawd  produclioti  nlone  would  be  inaiifficiait 
U'  miae  the  teniperniiire  of  the  body,  for  it  DiiKht  be  met,  up  to  k  vrrt  bigb 
Hmit,  bv  a  cniupeDiuitiiiu  increttse  of  luas  of  heil :  but  in  fever  ibi*  iiim- 
itetiiiniiikii  t.t  uuDiiii^,  luid  it  Li  [>erba{M  thb  abseooe  of  du«  regulatiun  «luch 
■«  iiKal  muit  chiiraL-tc-mlir  i>rthe  febHIo  cuudition. 

In  »>inic  ii>u1uilift>  the  ho<lily  ti<itip«raitiire  &lb  distinctly  below  thv  [i*jriual 
avornjp^,  n-ncliiu^'  Tit  iimtance  ^-^',  or  even  lou-er.  Ill  such  c*»e«  there  oio 
lie  little  iloubt  that  the  couditiwu  id  due  to  dimioishM)  ntetaboUuD  and 
diniintsbcil  livat  pmduclioii. 

One  of  till-  iiiuwl  marked  phoiiiiini;iiii  nf  iltirvatinn  \*  the  fall  of  l«n>jieni- 
ture,  which  tiroonKr;  very  rnpid  iliiring  the  iiwt  day*  of  lift^.  Tbe  lowered 
iiintatHiltMii  dimiiiixhw  ifit.'  pHKhiolinti  of  hvnt,  ami  the  lonered  leiDjieraiure 
in  luni  »till  furthi-r 'liinirii«hr«  the  nivtabiilitii.  lii'lti'il,  the  lo«r  tetnpera- 
tiirt!  i--<  n  )iiin'rrliil  tiu'tiir  in  hriu;.'iiig  iiImiuI  death,  lor  lifv  may  be  mueli 
pr»Ii>iigi-il  l>y  ivroppirig  n  starving  auimnl  in  sonie  ImuI  ounductur,  so  asM 
MODomixv  thf  bo<lily  heat. 

§  639.  Kffevt*  of  ffrnil  heat.  Aa  wp  «aid  above  tho  n^lative  heat  ■?■ 
chanisni  i>  iiiinble  lo  withstaud  the  fitrain  of  too  gran  an  externnt  heat  m 
too  prulongf^l  uii  exposure  tn  a  great  but  less  degree  of  heat.  Tbe  tempera* 
tiirc  of  the  body  then  rises  above  the  normal ;  and  it  has  Iwen  obaervod  thai 
th«  tcnipcrnlure  is  more  easily  raised  by  warmth  tban  doprvMud  hf  c«dd,  at 
least  when  neitber  arc  very  inteose.  When  eilber  in  ihii  way  by  exiemal 
nrarmib  or  throu);li  pyrexia  the  temiiemture  of  the  body  is  raised  foiiM  B' 
or  T'  above  tbe  normal,  to  4'V  or  thereabouls.  dealh  speedily  eiltMiai>  Tbo 
chain  of  evenle  thus  leading  to  death  has  not  been  as  yet  cletirlv  tnadr  out, 
and  moil  likely  (he  evenla  do  not  take  exactly  the  .-uue  course  iii  all  cam; 
but  tte  shall  probably  not  «o  far  wnmg  in  altributiiu  <Ieath  to  ttie  fact  that 
the  hi|^h  temperature  burrie*  on  the  metidii-lism  of  the  «verttl  tinues.  of 
eonie  luore  than  othen,  at  micIi  a  opt-ndthrifl  rate  ihnt  their  capital  is  aoon 
exhausted.  We  have  tuxn  (£  'i~2)  thai  loo  warm  bluinl  pruducra  dyapnwa 
and  soon  exhausts  the  metabolic  capitnl  of  tb<-  rtvpinilory  centre.  Too  wami 
blood  Mmilarly  hurrieM  on  the  bent*  of  the  bciirt;  an  explmion  of  tlie  coa- 
traclile  ^ulutani'e  i.i  cAch  timo  preniaturrlv  brought  on  before  a  sufficient 
quantity  of  cxplu«ive  mbstnncx^  ia  accumninted,  each  ntroke  lK«nm«a  more 
and  mora  foeble  as  the  rate  is  quickened,  the  Ih'hUi  bi-iv>me  irregular  and 
filially  cciuc.  lather  of  lhn««  two  events  bIoik-  and  ceriainly  both  luj^vtbef 
are  enough  to  brine  the  working  of  the  bodily  mrrbaniiim  to  an  end  ;  but 
Other  tiiMuat  beside  the  heart  and  the  respiratory  centre  arc  suflbring  in  tbe 
mme  w»y,  notably  the  rest  uf  the  oenlral  ncrx'ous  syvtom.  Thi^  too,  it 
being  hurricti  on  unduly  in  lis  inner  changes,  so  that  not  only  coni>ciou«ntaa 
is  lost  and  other  objective  mnuifcela lions  ot  nervous  action  go  nroug  nr  (iiil, 
but  that  regulatice  grasji  of  ihc  central  nervous  system  on  Uie  timiM  of  the 
body  at  targe  is  loosened,  and  tumuli  lakes  the  place  of  order.  Wbdher 
tfaia  or  that  sign  of  dieoriler  comee  to  tbe  front,  whether,  for  instance,  on- 
TulakNU  take  place,  would  appear  lo  depend  upon  the  exact  Uim  taken  by 
tbe sboornial  event^i.  A  heat-stroke,  more  commonly  known  as  sunstroke, 
the  eOMOtial  condition  of  which  seems  to  be  a  rapid  rise  of  the  tcmperitlure 
of  ibe  body,  owing  lu  a  fuddi-n  failure  of  the  therniutaxic  mechaniMii,  the 
aymptomi  var>'.  Njuieiinxv  thi-  heart  Biuldenly  gives  way.  at  other  limes  the 
nvpirnlorv  ceutrc  nei-ms  m  \w  more  diii-clly  iirtceied ;  mmeiimes  convulHton* 
make  their  appeurauce.  but  niure  i-uniniuuly  death  tiikei  place  through  a 


I 


BODY. 

<aBMlow  coDdiiion  of  (lie  hraiii.ati  initiai  phtue  of  exdtement  »t'Ui«  dentml 
armwB  >Taleni  beiiif>  uot  iiufrequ^Dllv  wiiuewei). 

)laninikliKD  muscle,  it  will  be  remeiulH^n-il  (i  M).  becomes  riKid  iil  alxtiit 
Hfi  but  deaUi  probably  alwuya  u<-'ciin  befitrc  that  hi^ihcr  teiii[>ersturv  is 
mchcd  by  the  bluod.  so  tluit  a  nurldeii  rigi>r  luorlui  from  beat  (rigur  calorls) 
naihii  be  re(,-»riM  an  a  faotur  in  ilealb  from  exiHAiire  to  too  neat  heal.  Ilul 
ibiMiIil  Lliai  temjierature  ever  bv  reached  by  tlie  living  btiay,  all  trc  Itixtw 
lods  US  to  infer  that  a  *u<tileu  ri^iiilily  of  (lie  whole  biMly  would  at  i>oce  put 
«a  abrupt  end  to  life;  to  nUfiiniie  that  ii  biimiin  budy  can  truly  ri-|^Mer  thia 
or  a  hign«r  tecnperalurc  whdv  rrmaiiiinj;  alin*.  t«  Miy  iiotbiug  ori>h<>wiiij{  no 
tokena  »f  ditfnaa,  entail*  the  mp|>ricilit>ii  that  KUch  n  hudy  aui  diflVr  from  iia 
fellows  iu  iu  abaolut«)y  ftiiiilanirnlid  qiiidilio*.  and  yet  make  Do  oth«r  aign. 

i  MO.  KJfttU  of  iftrat  fold.  The  fdect«  of  a  loo  great  lowvring  of  the  teiii> 
]«niture  of  the  bocly,  which  'a  ^crally  tlui  result  of  loo  grtM  external  eoUl 
lod  nrvly  if  ever  arittf*  from  internal  cnii»»  towering  the  meiaboliwu  and 
thiH  the  prodnctioD  of  lieui,  nre  in  their  oricin  the  reverwo  of  tbn»o  «f  a  ton 
bi^  temperature.  Tbe  meMbolisni  of  the  tiwucx  is  low«r<Nl ;  and  nut  only 
•re  the  aaiabolic  oban^  which  lend  to  the  «etting  tree  uf  energy  thna 
alAcieil,  but  the  anahnlte  changes  abn  share  in  the  dcpranioii.  The  "  livinv 
•uhManev  "  Gilb  to  jtiecee  Ion  neadily,  but  is  uW  made  up  leea  readily ;  and 
could  ihia  nlBcktoing  of  meiabolisai  be  carried  en  in  tlA;  acverul  ttMUea  Kt 
a  rale  pn>[xirtioData  to  the  rate  iit  which  each  tiwue  lives,  life  might  thuN  be 
hrou^'ht  to  a  {)en(x-fid  end  by  gradual  arrat  of  the  life  of  cturh  pnrt  of  tUu 
whole  iMMly.  And,  indeed,  in  some  CftMi,  where  the  lowering  of  the  tem- 
Deratura  takn  place  gradually,  »outetbiog  like  this  does  occur  even  iu  wntm- 
oiooded  auimal<>.  The  dimiutshed  nieUibolism  tells  Aral  and  cliieflv  on  the 
OWtral  nervous  fvsteni,  (specially  on  the  brain  and  more  particiilnrlv  '>ii 
Ihoac  parts  of  that  organ  which  are  concerned  in  coneeiouaneeB.  The  intrmsic 
toweriog  of  tbc  cerebral  nietalHiIiim  ia  further  aaaiated  by  a  slowing  of  the 
be«n-l>eRt  and  of  the  breath,  drownincM  U  sunceede<t  by  a  coodittoii  very 
like  to,  if  not  identical  with,  that  known  an  xlei-p,  which  we  »liall  study  later 
lai,  but  by  a  sleep  which  inveiuihly  ptuaev  into  the  sleep  of  ilealb.  In  some 
CKM9,  however,  eafieciallT  tbote  in  which  the  loweriDg  uf  tli«  teoiperalure  is 
iiiddeo  and  rapiil,  dlionleni  of  the  nervou* syatem  intervene  and  cunvuluous 
like  tbnae  of  aajthyxin  are  iiroducud. 

$  A4L  HihfrnaUnn.  In  the  mnjority  of  warm-blonded  luiiamU,  the  cuiidi* 
tiMM  thus  iuducnl  bv  oold  an-  rapidly  fatal,  and  mijreover  in  their  progrcH 
Tilj  waoa  mch  a  Btogi-  fr-nn  which  recovery  become*  iniiMMwible.  In  the 
Ktm  of  aocne  few  aninudK,  »ciit(rml  mcmbem  of  Mveral  groupx  of  mammalia, 
•  ■inilar  di-premion  of  nH-tal>ii|i»m  by  cold  is  of  yearly  occnrrcncc,  taking 
place  regutsrly  a»  tin-  «xlenial  icmpcralurc  falls  in  witiler,  and  bein^  thruwn 
off  regularly  lu  ihc  rxlcrnul  temperature  rises  in  spring.  8uch  luiiniab  are 
fpokeo  of  lis  hib).- muting  atiimalt. 

Wb  ara  not  able  at  present  to  explain  why  these  animal*  behave  iu  ihia 
wmy.  It  is  obvious  that  lor  some  reason  ihev  lack  that  power  of  rcactiou 
against  estemal  cold  nhU-h,  as  we  have  seen,  »  one  of  the  eh  a  raci  eristics  of 
toe  warm-blooded  animal,  but  we  cannot  state  what  is  the  dilfereuce  in  their 
Mooomy  which  lewis  lo  this  lack.  The  "  winter  sleep  "  is  undoubtedly  due 
to  (l>e  cold  of  winter,  and  may,  in  some  ca<«e  at  all  events,  be  induced  by 
coM  protluced  aniliciallv  in  Mimmer:  but  the  system  is  prediiposed  ami 
aila[>ted  to  undergo  the  ebungi^  nt  the  ap|H>inied  semon,  and  a  dormouse  may 
Gill  into  winter  ileep  itt  a  temi^racure  m  winter  higher  than  that  at  which 
it  awakes  in  spriug. 

The  pbeaoraena  of  the  biWruating  mammal  mar  be  described  as  tliooe 
doe  10  a  lower  rate  of  mctaliolism,  ami  Ikcnce  to  lowered  activity  of  the 


MTBITIOS. 

tlwuo*  in  genera).  TJie  heart  beals  verv  bIoitIj-.  nod  each  heat  m  »l  !»*■£  «rf 
but  inotic-rale  ncrt-ogth;  iiud  ihe  Ureaittt  are  few.  reebte,  and  far  beiwi-m. 
KoKfitnaioo  niid  drculaiinti  are  thii^  fT'^i"^  ou.  but  go  oD.  so  u>  sp««k.  at 
almost  ihft  nlonrtl  |)f»iblL-  ral*  cutinutem  wilh  (he  coniinuaiic*  of  th«  work- 
ing of  the  ecrtiioray.  The  liieath»  an>.  lu  we  have  said,  few  and  far  Iwiwtwi. 
bill  they  Kuffic^'  (a  carry  lu  the  tiiuue«  the  uasl\  ani^xini  of  oxyj^a  irlikh 
tliiw  Di-ful  (iikI  I'i  carry  ulf  the  .■■mnll  iiniouni  of  rarbontc  aeid  w  hicb  ibef 
jinKlitcf.  So  Kiiiall  i»  ihc  n':>iiii-nli'>ii  of  thi-  liMuee  that  in  the  dept)ij>  uf  Inc 
wint<T  iWp  the  vniDUK  MiHid  i«  alm<wt  en  bright  ob  the  arterial,  tlie  color  nf 
u-liieli  i<  niiirlv  normul.  And  ihc  «mali  aiiioniii  of  dettniclir«  kauMic 
changrv  w)ii<-h  i«  goiug  oil  U  Khnwii  by  a  ehniigi'  iii  the  rir«[>irsl'>ry  (|UOt>efil ; 
oxTgcn  i^  liiken  up  out  nf  pniprirlion  lo  the  rarWiio  nciil  i-xfiirttL  iDdeed, 
it  biLx  Imth  iiWrvril  thni  ii  dnrnmim'  arttially  tiainril  in  u'<-ight  during  a 
hil}t'rnnT.iii);  |K-rm(l ;  it.  diiichar^'d  duriii);  ibtn  pcrii")  m^ithur  urinf-  uor  {<^x», 
nml  Ihc  giiiii  in  weight  wn«  the  excm  of  oxygen  takon  in  ottt  tli«  carinnie 
acid  j;i\-cn  out. 

As  far  B»  rejmfl''  the  other  finx-iioim  i)f  tin-  h'Kly  all  that  oau  at  pnwat 
Ijcsaid  is  that  iticwvvral  rund.-inicnial  nctiviiic»  of  lherari«tp»  ti^HK^.  thoiigfa 
lo«n-red.  arc  itill  continiiol  Tcrv  niiicb  as  usual.  The  lutiwlM  ami  Ufrrmu 
elements  are  irritable :  indwd.  the  bilicrDating  animal  may  b«  sa'nk<^l  thougb 
nilh  diflicnlty  by  mlcqiintc  stimiihition ;  and  ik*  an  instance  of  tb«  funiia- 
mentat  similnritr  of  the  sleeping  ivith  the  awnke  condition,  we  may  My  tint 
the  slowly  heatinc  heart  can.  during  liiljernation,  be  still  furlhvr  slnired  or  bt 
arrested  by  etimulation  of  the  vagus  nerre.  The  essential  fntliirc  uf  hiber- 
nation in  fiiet  is  that  external  oold  ie  not  resisted  by  tbe  tiK-nnolaxic  nervottf 
niechaniBm,  Init  lowers  the  metabolism  of  all  the  tisraea.  and  thus  loners  ibe 
functions  of  the  whole  body.  When  even  in  deep  winter  the  liibcrDaiiag 
aoiiual  is  exposed  to  adeiguace  warintb,  the  inereased  temperature  awakes  tm 
tiwncK  tft  incrcaaed  metahutiiini.  and  ibc  awakened  animal  regains  tbe  bodily 
t«'mp<Taliir4.'  and  aetpiiri-ii  all  the  piin'cni  nhich  it  jHiwiiai.i)  in  niidHunimer. 

PrepHiatnry  to  the  oncoming  nf  hiheriintion  t.hi-  boily  lays  uti  nnusiiallT 
large  stt)re»  of  ftit  for  thi-  winter'*  extx'nditun^.  Many  hilx-niating  animali 
piMftw  a  "  hihermiling  gland."  tbe  Pffl.i  of  whi<'b  iKtrome  hnulnl  with  fat  In 
the  atitiinin  and  loose  it  dnring  hibcrntition :  but  in  all  caMw  tbi'  gn-at  itutc 
of  fat  is  in  the  atliposc  liwin-  geiicrulty.  Thi-  liver  of  the  hilwrniiling  ani- 
mal, at  all  events  of  the  dnrmmwe,  i"nnlains  a-  eonnidorable  (jiiantitv  wf 
glyoot^n,  which  may  be  rcgardc"!  u»  fjoite  cimipnmblc  to  the  hepatic  glyco- 
gen of  tbe  winter  frog  (S  J-i6).  The  fat  thns  sfired  np  Wforv  th«  appmadi 
of  winter  serves  as  the  main  snppiv  of  material  for  metabolism  in  the  wintwr 
elecp.  Since  during  the  whole  biWmating  fieriod  "onic  nmonnt.  al  lensl.  of 
oxygen  is  at  the  connnnnd  of  tlu-  tissues,  we  have  no  renson  to  think  thai  the 
metaboliBm  of  hibernation  is  fundaiuentally  diRerent  from  the  metabolism  of 
ordinary  life,  or  thai  the  stored  up  fat  ^iilfers  changes  and  gives  rire  to 
energy  in  other  nays  than  by  the  oxidation  ivhieh  fat  in  an  ordinarv  war 
undergoes  in  the  boilr.  Nevertheless  a  detailed  study  of  the  mvlabolisui  of 
liibenintioii  aceompunteil  by  direct  catoriuietric  ohservatioiw  irmild  probably 
diBcloae  intcn»itng  reriulta. 


Ox    NfTHITIOSf   IS  GEXER-tL. 


S  643.  It  mar  now  W  profitable  to  take  a  brief  Him'ey  of  tbe  varioua 
cnnchisiom  nl  which  tvc  have  arrived  concieruiug  ihv  pmhlem*  of  nntrilfou. 

We  hnv*;  seen  that  the  several  liwinftt,  using  Ivniph  a»  a  mealinm,  livo  upon 
the  blood,  taking  ujt  from  the  blood  the  mntennU  for,  and  rvtumiog  to  (be 


be  producli  of.  lh«ir  nwinbotUm.  Tbi-  blootl  itself  w«  luva  aIw  wen 
'litenisbml  with  Wwti  froiu  ilii'  nlitiicnl«ry  ciinnl  tan\  with  oxygea  from 
lun^anil  to  bt- frtrtl  Iroin  nn»ta  pruiliicbt  by  lucAn*  of  the  Dxcretorf 
oTBUM.  In  this  tl<>ubl<'  m-tioD  tlit<  ntir  imKcHal  nl'  ihv  Ibod  on  tliv  one  buid 
nBdergue*.  bcln<-vn  its  bi'iiiL'  nlncfil  in  (1h-  mouth  nni)  its  Inkine  part  in  the 
■HUUJiflin  iif  iW  tiMiii'  wind)  ultiniuielv  u»ce  it,  rnniiy  iDtcrtncdimio  cliauRce 
oafritd  iw  in  vanuiu  parta  of  the  body,  nml  the  n«4t«  products  iiimilsriy 
uadfrco  talcfmediatc  thangca  belween  leuviug  the  liMue  aiitl  appearing  in 
iW  uniw,  tbc  aweat,  or  thi-  expired  air. 

VTe  have  lurth«r  («en  reoaon  to  think  that  tb«  metabolic  eveuts  of  tiie 
hixly  take  placP  in  the  niuin  in  the  tiasuee.  not  in  ibe  bloud  stream  on  ila 
my  between  the  bean  and  tbe  tifisuet.  Ctiangea,  uroiter  tu  the  blood  ilaetf. 
take  pUoe  in  ibe  bloud;  tbe  corpuscle*,  red  and  wliiie,  with  tbe  jilaarua 
undeno  like  the  mt  of  tbe  body,  their  |>r(>i)er  metabolic  cycles,  and  in  tliU 
MiiM!  lih-od  inay  be  calkd  a  lieaue  if  there  ii  any  advauitifce  in  udng  llie 
|ibra*e ;  but,  ufArt  from  these  iiiirinHic  bhuid  cliimgiw,  na  far  lu  we  cuu  te«  at 
prtaanl,  tbe  metaboliaiu  uDderuoue  during  their  transit  alons  the  bhut] 
cbaimela,  by  the  sulelancee  whic%  are  merely  carrietl  in  the  blmid  tVom  j>lave 
to  pl<KC,  ■»  nu  iiuignillcaut  part  »f  tbe  total  lueiabnllscu  nf  lh<i  tuidy. 

By  meiabolium  of  a  tiMue  we  undci-ituiiiil  the  lulal  vhemicnl  chanjccn  taking 
tiEac*  in  ibc  linue;  and  we  divido  tb»)e  change*  iuEii  thmw  which  either 
uirrvlly  or  imlirLt'tly  are  c»n(.'L-ni(.-d  in  the  building  up  (nDnbiilici,  and  thow 
which  an'  in  like  inauiier  cDiiocnied  in  the  lirotkinjc  down  (kiilahnlic  i  of  thu 
lixing  Hibetancv.  We  •hall  exjiluiu  im^tcnily  wluit  uu  mean  by  iht-  words. 
"dinieUv"and  "  Judird-llv  "  u«sl  in  [hiN  omuection.  .\ud  w'c  may  bore 
mmM  tne  caution  (|S  .'10)  ifial  thotigh  fur  convcoicuca  take  we  unv  the  phnun 
"  Bving  BUbctaticv."  what  m  rvully  niouit  by  tite  words  u  not  a  thing  or  body 
of  a  particular  clwniicul  c<^ni|ioaition  but  matter  ui>dei^Dg  a  aori«a  of 
chanift*. 

J  M3.  irince  llie  eevcra]  tiwuea  originate  through  a  ditTereiit'olion  of  tbe 
unpler,  primordial  proloplosiD.  ne  may  infer  that  we  have  a  ri^hl  to  apeak 
of  a  getMrnil  plan  of  metaooUam  common  to  all  the  tiBsnes,  modified  in  vari- 
oai  pvliculars  in  various  tiasuea.  It  ia  more  reasonable  for  instance  to  sup- 
pose that  there  is  such  a  general  plan  oommon  to  both  muicle  an<l  glau<l, 
than  to  i>ii|i|K«e  iliat  the  metabolism  of  the  one  ditlera  wholly  from  or  only 
atx'i^l (11  tally  ri3>vuible«  that,  uf  the  oth»r.  And  we  may  pnifiiably  take  tlie 
oatritioD  lit'  auscle  as  exemplifying,  in  the  midst  of  the  features  apedal  to 
tbe  nusclo.  the  general  plan  of  vital  meiabolbm.  The  muitcle  in  a  uorual 
Mala  of  thing)  livcfl  ultimately  on  tJie  pruteids,  fai«,  carbobvdnttes,  salts  and 
WMtt  of  Uw  tboil,  and  on  the  uxygeu  of  the  iiuplrvd  air,  but  livtn  directly 
(Ml  the  blood  which  briugH  theM  things  tu  it.  Taking  thi-  pruleids  first  wft 
may  ask  tbei|unt)on.  How  d<)«»  ihi'  bliHxl  >upuly  thu  luuacle  with  proisidaf 

TIm'  hliM-id  cunlniiM  three  cla-ticH  of  prutvicin:  1,  *erum-albuniin,  '2.  glo- 
bultn  (paroglobulia),  ainl  -1,  librinogen — that  14  lii  say,  tlic  IxHly  or  bodies 
nnocwiMd  in  tbe  clotting  ofblnMl,  nhwe  nature  we  lull  in  ^  '2'i  n»  tun  wholly 
and  clearly  made  out.  With  regard  tu  tbe  function  of  ihese  thrtv  kimU  of 
pmlwKis  in  the  uutritiou  uJ'  muMle  arc  only  cuncluiion^i  ul  present  are  indi- 
rect noes,  based  chielly  00  the  mtults  of  cxpcrinienis  as  to  the  relative  value 
of  llieae  substancn  in  niainlaining  or  mtunng  the  irritnbilily  of  muscle.  It 
is  fouwl  that  when  tbe  woshnl  out  frog's  heart  (!i  162)  is  fed  with  dvObri- 
natol  hliud,  the  reslxrntiou  is  as  fjood  as  with  whole  bloud ;  oixl  that  while 
tbe  etiectii  uf  j-lohuliii  are  univrtam,  and  while  peptone  and  lUbumuw  appear 
looct  in  an  iujurious  m.inner,  the  rwiorative  oflects  of  eeruro>albumin  Am 
morkcil.  Kruiu  tlieee  result*  we  nuiy  provlsioiuilly  infer  that  the  muscle  in 
iu  (total}  anabolic  dianges  take*  up  and  m  livve  uptui  the  senini-ullHiniin  of 


I 


Nl'TBlTIOS. 


the  blon<3.  Bill  ibU  n>nrlnsbu  must  be  ivKiinled  ns  pmriMonal  only.  aiuI 
iii<lcr<l  iiucenaiii.  For  we  niuM  renwuibcr  ili«t  the  blixMl  iuiM>liea  not  only 
ttitt  futiil  (iiivluiliiifc  oxyKCtij  for  the  niiiscle.  Wt  »}»&  tJie  coonitioiu  under 
vbicli  tbc  iiiu*c!e  can  ifvc  niul  arail  iUelf  of  tli«  food  nfftred  to  iL  The 
C»ni[)k'x  ucri'>ii!i  lhmii|,'li  wliit-h  n  (.■ertiiiii  udatitilir  uf  i<nilc!(I  and  other  iaai«- 
riiil  i>  built  lui  inln  Itviiij;  intitcular  suWniiix-  Dec^l  lor  th«ir  execation  a 
fnvoralili'  nit-iiitini.  nerd  (vrtuiii  jibyvjful  and  rht-niinil  condilinott ;  aix)  11 
luitv  Im-  ibnt  llii^  tuviiiiibk'  iiifliit-iice  of  wenim-iilbiimiii  ix  »itD]>ly  iliic  tu  jti 
]>r<-M'noi'  in  lonii!  wiiy  nfsi.-lirig  ibr!  iruiisfurniHltMi  into  living  subclani'v  cif 
raw  iiiHlcriiil  dill  miininitij:  id  the  muvtiibir  fibre*  nod  not  to  it«  flUp[)l;iD]; 
nvv  raw  Rmtrrial. 

Dcxirivc  i«.  w  we  hnvv  r<-|>m telly  Miid,  nlwnjrs  pncecnl  in  th«  bU»d  b 
Mnnll  quantity,  mid  appoire  to  l>c  the  iiiily  cnrbohydrate  can>ti(iiHni  of  bbnid- 
pltuina.  Exficriniciite  curried  nut  on  u  liirge  animal,  such  a«  tlip  borw  or 
cow,  bare  rhown  that  the  venous  blootl  coming  from  a  rauectc  contaiDr  Itat 
dextrose  Ibnn  the  nrterin!  blood  going  to  the  muscle,  nod  ihat  the  dilfemi<* 
is  much  iDcreflHcd  by  throwing  tbc  miiiwle  iiilo  eooiractioa.  From  ihL'vt 
D>ay  proi-isionally  conclude  tliat  dextroie  is  an  ewenUal  part  of  the  food  «f 
I  be  muecle. 

The  blood  as  we  have  seen  aim  coiitaiDH  a  certain  amount  of  fat :  and  if 
we  push  the  analogy  betweeu  the  whole  body  and  the  iiiuM'le,  we  may  infer 
that  the  muscle  iaKe»  up  fat  as  food  for  ilaelf  fri>m  the  bbiod.  Uut  we  have 
no  ex|>eririienlitl  evidence  in  iavor  of  this.  Moreover,  we  have  seen  that  fiu 
uud  earbiiliydrale  arc  in  the  animal  body  more  or  lea*  imnxfi-rable.  We 
have  distinel  primf  ibat  the  bi>dy  can  trausform  cartmhyilraie  ini»>  fat ;  and 
it  is  very  pmbnble  that  il  can  trausfonu  fat  into  cnrliohydiaie.  Seeing  h>»« 
niueb  more  easily  a  soluble  (lilTunible  carbobydrntti  like  Hugar  isu  Iw  carried 
fr<.>m  place  to  niaoe  by  the  llui<U  nf  the  body  thiin  can  iiiiiiiU<-ible  bts,  it 
w<ent»  rensouable  to  sujijioni-  tliul  vrhrn  the  IumIv  hat>  to  ilriiw  up-iD  ita  slort 
of  fut  in  ilx'  cell"  of  iidiprwi'  iii»ii<-,  the  fat.  on  lesvini;  the  fal-ccll  is  tran*- 
fonucd  into  :<iignr,  it*  carbiin  i"i  to  »poitlc  being  dealt  out  to  the  liMue«  in  lbs 
form  of  dexinx.-.  Imlccd,  we  may  perliape,  dwolltng  on  tbc  fai.1  that  a  mus- 
cle though  itself  c«»entiitlly  of  prolcjd  buiUI.  turns  ovct  I^  KT>  in  its  daily 
work  w  much  more  carbon  than  nitrog<?n,  entertain  the  rieu-  that  what  mm- 
cle  want.i  as  food  is  n  corlnin  aniounl  of  proteid  plus  iin  additional  quantity 
of  carbon  in  some  fonn  or  otber.  and  that  dcxtroae  is  a  convenient  t'oroi  in 
which  the  additional  carbon  ctin  be  supplied.  And  ne  may  hold  this  view 
without  prejudice  to  any  opinion  that  the  carbon  m  bntuKht,  while  betne 
built  up  into  the  living  substance,  may  be  again  arrungeil  as  fat,  and  in  the 
course  of  the  melalwlism  of  the  muscle  may  be  later  ou  separated  ftom  the 
living  substance  and  deposited  in  the  fibre  its  globules  of  fat.  But  our 
knowledge  is  at  prescni  iusuflicieut  to  decide  whether  this  view  is  true  or  na 

The  various  sails  bn>ugbt  to  the  muscle  by  llie  pbuma,  though  they  itupply 
ao  eDersr  are  ss  •rMeniiat  to  the  life  of  tuu»cte  as  the  eue(^y>holdin;$  proteid 
or  carbon  cciui{>ound ;  and  exticrimeniA  made  with  regard  to  Auroe  of  iliem. 
oalcie  salts  for  insliince.  sho»  ilinl  thrir  iireMUceorabsenoe  materially  aflect* 
the  maintenance  or  reeti^>ratti>n  of  irritability.  Souti;  of  tfaetc  probnblv  plsj 
the  pan  only  of  securing  by  their  presence  fitvorable  oomlitioM  lor  liie  dnv 
metabolic  proceceee,  somewhat  after  the  way  in  which  the  itnaeiMM  of  raick 
phosphate  ddermiuoe  the  curdling  of  milk;  but  Mmc  we  protMhlr  ttugltt 
to  rqpird  as  at-tually  entering  into  the  procenoe  tbeiuwlvw^  6f  these 
mattent,  however,  ne  know  very  little. 

S  5M.  The  end'ppxlucu  of  mu.-b^ular  mvluholixin  are,  us  ire  have  soeo. 
carbonic  iii'id,  lai'iic  acid,  and  krealin  or  some  other  nil^)geilous  bodies,  aod 
we  have  already  (J  til)  cuid  all  we  liave  lo  say  concerning  the  foruiatioD  of 


I 


I 


tb«a  prodactt.  Wc  mar,  honever.  bnflr  comiiler  here  ibe  <|Ueetiou.  What 
I*  Out  rvUUuii  nf  llit«e  varioiiH  imtHliolii.-  pr'x.'OMe*  to  ihe  einiclural  el<eni«l>li) 
«f  ihe  liMueT  Wbiii  ir«  uiv  iliat  Itie  niuiM;u)nr  tibr«  is  coiitiuualiy  timW- 
gahtg  tneUbolisai  do  we  mean  that  ererj  jot  aiul  tiiile  of  tlie  fibre  is  umler- 
goinp  rhaiip^  ami  thai  ai  the  taiuc  rnle^  We  can  bardir  siipptibe  tbia.  It 
•Htii  utiliki-lr,  fur  iii»tauce,  that  the  metalxilisiii  ot'  the  librillar  sulMtmice  ia 
irWntirMl  wilb  that  of  the  iuterlibrillar  atibdtaiiue,  whatever  be  tlie  vien  n-e 
lakr  a*  to  ibe  ]>r<>|>ertia  or  nieaiiinf;  of  tbe  two  »ul)fiaiicM.  Furlber,  if  w« 
•rrq)t  tbe  *uggt*tiooa  made  id  ^  >*7  iiv  to  n  roi)  tract  He  substance,  whicb. 
llnMiffh  liaviog  peculiur  iiiiulitio'.  I>eiii||;  twc^uliarh-  ri-Iatcd  ti>  and  haviii^c 
ppfuTiar  (■onmclioua  v'nh  tbe  rtvt  of  the  fibre,  ranr  in  a  bmad  nnv  be  miu- 
]mtr4  with  lh«  gl^Mgcn  "(  a  lieputic  rell,  wt-  cau  coi:cdve  that  ib^n  cuiiti-nc- 
dlr  •uhctaiioe  may  1<«  niaiiulueturcd  vithout  tb<'  nholc  of  it  at  Iniiit  bavins 
bam  at  aiiv  tiiue,  aii  integnil  {lart  of  what  uc  niav  in  a  Mricler  h'Iim:  cnll  tbo 
ml  Uviog  HlbMauoe  of  the  Bbrc.  Wv  >bniild  tbii*  1>c  led  to  regarxl  lhi> 
BiMabotie  emnta  oceurrintr  iii  diuri'Ic  n»  lulling  into  two  cIa«M*  at  Ien»t: 
lb>w  Inking  )>Iacc  in  ibr  living  Rinri*  {x^niiiini'nt  fninicn'orlc.  awl  thoM  bear- 
ing  uu  ibr  t'iniitiiion  and  dtvlruc-tioii  »f  itic  ctinirni-lile  Mibrlaiice  lodind  in 
Utat  living  rrnniowork.  Fnrlher.  it"  we  Mipiiii»c  tbal  the  n)elabuli»in  by 
wbich  the  tniiM-les  nuppl}'  «o  mnt-h  of  thr  beat  of  the  ImhIv,  and  which,  n;>  ne 
hav«  aeen.  may  nixl  do<«  go  oii  indepcitdenlly  of  i»n  tract  ions,  i«  not  n  roe- 
ubolicni  of  th«  mine  contraclik  siilwlaiiec  iliHering  from  tbe  mi-tabolism  ot 
a  ei>ntraction  in  bejitg  au  onl<-red  that  all  ihc  etier^'T  ^<i08  tint  as  licAt.  none 
bcin^  Moploved  to  eJAct  a  chance  of  form,  but  >!>  a  inelaljolisnt  of  »ome  other 
"UMCinoftiiic"  HbetaDce,  we  Miould  bnvc  to  add  a  third  ebi««  to  tbe  other 
two.  These,  of  «>iin«,  are  at  present  lualterv  uf  spectitation  ;  but  ««  tbe 
whole,  ihe  evidence  we  can  gather  leudii.  anil  perbajM  iucrea«inf>ly  len<K  to 
(iuiw  that  in  muscle  there  doe^  exist  such  a  framework  of  wbitl  we  may  call 
morv  dUtincllv  living  au))«i8iice  which  ralej  the  btstological  features  of  Uie 
Bbra,  and  wbuae  mstabolum  ibouji-h  high  in  quality  doea  not  give  riie  to 
BMMTff  discharges  of  energy,  and  thai  the  interatioea,  io  to  ajMak,  of  tfala 
frwnewurk  are  uccupteil  by  various  kindii  of  material  related  in  dillbreiit 
dtfcree*  to  the  framework  and  tliereloiv  ileoerviug  to  he  vjioken  of  as  more 
i>r  lew  living,  the  chief  part  of  the  energy  tei  frve  by  muKcle  coming  directly 
frun  ihv  melabnliam  of  aome  or  other  of  thi»  material.  And  tbe  Hime  vKV 
■lay  b«  oxteiKlcd  to  other  titwutv^  Both  the  framework  and  ihi;  iiilcrcalalLxl 
naicriaJ  umlergo  metjibolism,  uiid  havr,  in  ditlercnl  degrei^.  ihcir  aimlHilic 
and  kalalxdic  dmiigiv-.  both  are  coiicrrmil  in  the  life  of  the  living  Hulmliince, 
bat  0D«  raon-  directly  than  the  ulhi-r,  and  thi.-<  is  what  was  nH-ant  by  tlte 
larnn  "  directly  "  and  "  indirectly."  iimil  iu  S  642.  >fuch  n  luotb)  of  axprea- 
■ioo  arems  prH«rablc  to  the  morv  common  one,  hns»l  on  the  aiialofii'  of  a 
Gnarm,  of  tbe  muscle  fibre  firing  oH'ihe  ctintrnclilc  material;  in  the  tirtvirm 
there  arc  no  such  ooiiDeclioiix  iK-tween  ibo  machine  and  the  churgus  as  obtain 
in  tbe  living  iDcrbanism.  We  may  perhapa  further  bo  led  by  this  to  dis- 
tinpitsh  IwtwoMi  growtli  a*  bearing  on  ll»c  framework,  and  more  icmimtary 
DUtritioii  as  beiinng  on  tbe  accumulation  and  cxpetidiliin'  of  tlie  lodged 
oMUcnal.  We  may  add  tliat  since  some  of  the  material  so  bxlgetl  in  the 
fruMWork  will  consiel  of  rahstances  which  have  not  yet  undergone  melabo- 
KaiD,  biit  are  eitlier  about  to  Im  worked  up  into  the  Iramework  Itself,  or  are 
about  to  he  transfomMjiJ  in  a  more  direct  way  into  some  product  of  niflabo- 
Unn,  or  are  substauecs  whose  presence  is  in  sume  way  oeooaary  for  tbe  carry- 
tBgoa  of  metabolic  proeeeaei  in  which  they  tlwtmelves  take  no  boility  part, 
««  must  recuxnize  a  continuity  without  any  sharp  break  between  ihic  mate- 
rial ubieb  we  rct;ard  as  ]iari  of  the  tiieue,  niiil  the  lym|>b  which  simply 
bathe*  the  liwue  and  llotrs  through  the  interstices.     Hen<«  such  pbnuea  as 


658 


NTTRITION, 


"tiKiiv  [irotctd"  auil  "  llouiinx  |)ix)te!<!."  $  5'J3,  nrc  umledinible  if  iber  mn 
uii<le»ton<l  t»  iinpl}-  n  »linr[i  tiiic  of  (l«niarc»tti>u  belnd-n  thv  "  tJntUQ"  and 
tli«  blood  or  lyuipti,  iliotigh  lucful  a*  lodicutiiig  two  dilTcrent  line*  or  Jigiew 
of  tneuibulinm. 

S  MS.  Ttic  jinMluou  of  nitifculMr  niotabotijiiii  [kum  into  tW  ly(ii[i)i  Imlliing 
tile  lUiru  iini]  mi,  ncht-r  by  a  ilirci't  piiih  iiilo  tlin  cnitilluriov  or  l>y  u  nxin 
circitiitoii*  cotiRW  ihmitjih  ihc  gdicml  iyniphntic  f^-'Wn.  intu  the  blowL  Thm 
fitlcol'thc  citrboiik'  nejd  wu  bnvo  tolly  trvutml  of  iii  dcmlitig  wilb  rapintioD; 
tb«  littlo  wo  know  concerning  tli«  iiitragcnous  pmduci  or  pr»i)iicta  du  bean 
minted  in  dvxiltng  with  iirva;  the  third  rcL-ognizcd  proiluct  i»  Itctic  xdi). 
Mtrcotnctic  ncid.  Did  iin|-  con »ide ruble  timoiitit  of  oxid«lioii  InIcv  plflcv  in 
the  blood  Blrcam  while  tbc  bloud  is  tloniiig  alon;;  the  larger  c'hjinti«lf,  lub- 
ject  only  to  the  influence  of  the  vaiciilar  walls,  we  might  fairlr  expcd  that 
the  lactic  acid  dischar^^ed  from  the  musclee  irould  bcnbj«cted  to  oxidUioc 
influfinces  while  still  within  the  blood  stream  of  ibe  laryer  cbaoDele.  Wc 
have,  however,  no  saiJBtactory  evidence  of  any  laaic  acid  betpg  oxidiied  is 
thb  vBjr.  On  the  contrary,  there  i^  a  i.'ertatii  amount  of  experimeDlal  and 
other  evidence  that  lactie  and  pr(.<Mnt  in  ib«  blood  i*  touteliow  or  other  ^ 
posed  of  by  the  liver:  niid  that  if  the  liver  fail  to  d<>  ita  duly  lactic  acij 
may  aiipear  in  the  iiriov.  It  i«  tcmpliu}!:  to  nuppceu  that  it  mifcht  then  by 
a  iyntJtctic  etl'urt  tw  converted  into  tclv'-''^S^''>  '"^  Iivlt  ibiin  utilizing  aotn* 
of  the  mUNcubu-  wiutlv  prodiirt,  1>ut  thi;  uxperimflnia)  and  other  vvidioicc  i) 
all  a^ni>t  thi»  view.  In  fniilt  of  iictiial  knowledge  ire  are  led  to  iofir  (hat 
it  it  in  the  Iiv«T  nxidixpil  int»  carbonic  acid  and  water,  thu«  aiMing  its  v»i>- 
Iribuliun  to  the  mipply  of  heal,  or  prrpiin^  in  mdm  way  for  oxtdaiiun  elMv 
whore.  Probably  «iich  n  changrt  i«  not  confined  to  the  liver,  but  inkt*  place 
in  other  orgaof  fiich  nn  the  spleen.  Thns  the  kind  nf  uclioii  on  which  we 
dwelt  in  Ireitlin);  of  iircn,  namely,  that  the  pnidiicls  of  the  nictaboltsni  of 
one  iHfi&u  are  larrie'l  ti>  other  orgaiu  for  further  elaboration  am]  poariblr 
uiiliMiiioii  Hpplieii  to  ibe  unu-uttr'i^nous  as  well  as  to  (he  Ditnigeooua  pro- 
ducts of  mo«cular  inelabuliitiu :  and  if  a  oiuacle  nWet  t'tx  to  other  noo-oitio- 
^enout  prutlncta  than  carbonie  and  litctic  iici<l  tbeae  are  pmbably  dtcpoaed  of 
in  some  such  way  as  the  lactic  acid.  In  xpeakinx  of  ijlyco^eu  in  the  winter 
frog  ($  4(il )  we  xaid  that  puwibly  the  gtycofrcn  *•>  «turcd  up  might  ari.to  from 
sugar  brought  to  the  liver  IVom  i>ther  liiwuei.  If  that  1m>  w>,  we  ulitnild  fur- 
ther expect  that  «ome  nt  K'usl  of  that  »ugar,  eitlivr  ax  Kucb  or  at  wmv  allied 
Biibntance,  would  conie  from  the  »kclclal  inuttclcn  which  form  m  largv  a  part 
of  the  body  of  the  frog;  aiid  if  bo,  wc  niuct  conclude  that  uiidttr  the  Hpvcial 
circnni Glance*  obtaining  in  Ihc  winter  l'r»g  thu  muselot  diNcharge  into  the 
blood  a  non-nitrogenouR  product  not  iti  the  form  either  of  carlionic  or  lactic 
acid.  It  is  {K-rhaps,  howe\-cr.  more  probable  that  the  migar  in  ipiei^lion  coniM 
from  a  metabolism  of  the  fat  slorod  up  in  the  "  fatty  bodies  "  and  clmwboiv. 

^  646.  As  far  ns  we  can  sec  at  prroent  the  plan  of  nutrition  tlius  briefly 
sketched  out  lor  muscle  holds  good  for  the  other  liMiiee  af  well,  the  chief 
or  at  least  the  most  oanspiflUOtls  ditlerencee  bearing  on  the  nature  and  ttrop- 
erties  of  and  ibe  changflB  undergone  by  the  material  formed  by  and  held  by 
the  more  distiDctly  structural  fVamework.  Thus  the  mnda  oT  the  Balirary 
mucous  cell  linds  ila  analogue  either  in  the  coolraciile  subsilance  itself,  or 
mora  prtdiably  in  some  early  nitrogenous  product  of  the  exptr^ion  of  the 
ooiiiractile  xilntance.  Rucb  as  may  correspond  to  the  myosin  uf  rigid  tnusclo. 
Tbc  mctaliciiiiim  of  the  hepatic  cell  seems,  as  we  have  seeu,  to  be  eapMiolljr 
vharacterixed  bv  ii^  returniMK  to  the  blood  a  body,  viz.,  «igar,  still  couiain* 
ing  a  connideradle  umt>uni  of  enftrgy',  available  for  use  iu  other  part*  of  the 
bMly.  Aii'l  tbi»  -Migijiiit.i  the  'juetition  whether  iu  the  normal  mvtabolisni  of 
muKolar  vulutancL'  a  similar  itomething.  .itill  holding  a  considerably  qDnnlllf 


I 


4 


OS    SCTBITION    IN  GKKKRAL.  667 

,.  natr^j.  tome  prototi)  •ubsliiiiea  for  inttiincp,  may  not  be  rctiirDnl  tu  the 
blood  :  tn  iliiii  llR^  mtliibolltn]  of  diuwIc  i*  iiapc rfc<-l1y  dcvcnlwil  in  MTine  M 
tint  lb«  r»iilt»  nro  carbonic  and  Ikclk'  uvuii'  ni)']  mi  Btilrc<.-<lcnt  of  uim.  It'  V 
tbJB  bv  so,  ihni  n)uscl«s  may  bo  uf  otber  iimt  to  the  body  at  liirgc  than  m 
own  c<>nira(-lile  nmchincn.  jiiM  ns  ihc  liver  han  other  ums  than  the  produc- 
lioa  of  bile.  And  the  Bonie  coti  side  rat  ions  tuny  )m-  appltcd  to  the  other 
tknta  Hi  well. 

$  547.  Whether  the  chief  proiluot  of  the  iucia1)oli»Ri  of  any  tissue  be  a 
IMMcmI  tfibelance,  or  n  fat,  ur  a  carbohydrate,  proteid  substanco  ia  the  pivot,  ■ 
B  to  fpcak,  of  the  melaboltsm,  and  nitrogenous  bodies  ainays  appear  an  ibe  I 
(irodlieta  of  oielabolism.  Tbi#  ia  striliingly  seen  in  the  outrition  of  plants 
vbere.  as  far  as  oiert;  bulk  or  weifiht  is  concerned,  the  active  nietabolianK 
tisoe  ii  insi];nifi<-aDl  compare)!  with  the  mua  of  products  of  loetabolum 
liMped  up  in  the  form  of  starch  or  celluloM  or  some  allied  carbobydrnie. 
Tb*  protoplasm  <>f  a  vep.-tahle  cell  soon  becouiea  a  mere  Sim  bearing  a  heavy 
Inrmn  ot  hi-aprd  np  mt^iabolic  prvdncta  and  eventually  diaappeare;  and 
of  that  lllu  only  a  tiart  eorrenpondii  to  what  we  tpoke  of  aoore  aa  iho 
lirinic  framework  of  the  musde.  Yet  that  scanty  proteid-built  framework  ]» 
nor*  or  Ins  directly  concerned  in  tiie  imxliK-tioti  of  the  carbohydrate  mato 
liU  and  the  Tartuua  cocavertiun*  whicii  that  material  underj;ot«.  FnXeid. 
nitrogen,  clian^x  are  pntaugleil  with  the  carbon  diangea;  and  since  the 
product*  of  uictabolii^in  iu  the  plant  are  nut  as  in  the  animal  cant  out  of  the 
organunn,  but  for  th<r  mtvl  pari  hea[icd  up  within  it,  n'C  find  ibc  plant  storing 
op  in  pan*,  whvrt-  if  they  serve  no  uwful  pnqiiisc  they  at  leant  do  no  bann, 
nitnigtoous  pnidiicts  of  ni«laboli»m,  such  as  those  knunn  ns  vegetable  alka- 
l<Hili,inany»J'nhich  by  their  amide  nature  betray  tlieir  kinship  to  the  animal 
■tUwtnoua  pnxluct  area. 

I  548.  The  mtr  nl  which  in  the  adult,  leaving  asid<^  f'lr  the  present  the 

rial  nutrition  of  the  voung.  nutrition  is  carried  on.  and  the  characlers  of 
nutrition,  are  dvpendent  on  a  variety  of  circnnisiances^  Knch  tissue  has 
of  course  a  line  of  nutrition  of  its  onn  which  circumstaaces  may  favor  or 
hinder  but  cannot  chan^,^  in  nature :  the  nutrition  of  the  hepatic  cell  cannot 
be  altered  to  Uiat  of  the  niuBcular  fibre.  The  tame  tiemi^  moreover,  has  En 
different  races  and  diireretii  individuals  specilic  and  individual  characters  of 
nutrition;  the  tiesh  of  a  dog  is  not  the  same  a«  that  of  a  man.  the  muscle  of 
eiw  man  livw  dtSerently  fi^u  that  of  anniher,  the  metaboliiiui  |>er  unit  of 
budv  weight  is,  ■•  ire  have  >)ceu.  greater  iu  the  suialler  urganiam.  and  so  on. 

Wilbin  the  limits  and  subjevi  to  (lie  cunditiiins,  however,  thus  llxed  by 
race  and  pcrsunality,  general  mtlueiiem  produce  general  variatiuna  in  niitri- 
tiun.  The  rale  of  uuiritiun  uf  a  tiwiie  for  instance  is  de|>eDdent  on  the  food. 
OB  iho  amount  and  nature  of  the  IWI  material  brought  to  the  tissue  by  the 
blood.  W*  have  seen  that  pmteiil  t\«»i,  in  cnutrast  to  carbon  food  markedly 
ittcrMMt  the  mMabolisDi  of  the  hiNly.  8ince  this  increase  tells  not  only  on 
ibo  siUogCBOUO  but  also  on  the  carlxMi  metabolism  (§  fi24}.  it  cannot  be  tho 
mult  of  a  mere  luxus  consuinntion  of  the  protud  food  itw-lf ;  and  unUw  ne 
nppoM  that  the  prvfcnce  of  the  cicow  of  pnMeid  material  either  in  the  ali- 
aMOtarv  canal,  or  while  pawing  through  the  capilUries  of  some  organ  auoh 
w  the  liver,  ads  as  a  siimulur  to  some  reflex  nervous  meehinerj  throvgb 
wboae  action  the  metabolism  of  certain  or  of  all  the  ti«sue»  is  hurried  on,  w« 
tniut  conclude  that  it  is  the  direct  aeiTss  of  proteid  material  to  the  tissues 
themselvee  which  stirs  them  up  to  inerciieoil  metabolic  activity.  That  pro- 
teid  food  should  do  this,  aivd  not  carlxihydrale  or  I'at.  seem»  to  be  connected 
with  the  fact  just  dwelt  on  that  proteid  natorial  is  the  pivot  of  metabolism. 

I  549.  In  the  preceding  chapters  of  tbts  work  we  have  had  abundant  evi- 
litoce  that  the  metabolism  of  tlie  tissues  is  subject  to  the  government  of  the 


I 


668 


Xl-TBITION. 


central  nervoH*  ttj-nlcm  :  the  coninieiiiui  of  n  muscle,  the  tecnbtrr  actlvitjr 
of  ft  glMul.  tlir  imrwuwil  or  ilimiiiUhivl  tinvlucti'xi  of  heart  nil  itlfon]  in- 
bUdccs  of  iiervotis  inipulKv  nllt-clini;  nidalioliitni.  In  must  of  tlictv  itwtaDD* 
tluj  cbnngcs  induced  tnll  oiihiti  tli<-  itowiiunnl.  knUibnIic,  phniw  ninl  bnv«  ■ 
duwnward  ehnrnottr;  (hue,  uhon  ii  tuuHclr  contracts.  Ihf  mult  i*  ■  ntnnr- 
«on  of  more  com)>lrx  Wlies  into  t^iniptcr  bodies;  nn<l  ihe  ■amr.  kn  fiir  ■•  «• 
(-nil  MC.  is  true  iif  mosl  other  mses.  But  it  is  open  fur  ue  to  siip|>ue(<  tbu 
Dcrroiif  inipiilficfl  might  affecl  thv  upnnnl.  nnnboltc.  phue  mxi  haw  n  cud- 
Btnictive  iiiMuencc.  There  nre  no  rcHsons  for  regonliug  nieh  an  aetioD  a^ 
inipoe^ibic;  and  indeed  some  nfaenotncna.  eueh  aa  llioae  (^  inhibitory  oenrei 
and  the  antagoniHin  between  thofe  and  augmenlor  nerves,  poinlclly  suntU 
some  such  view.  Thus,  we  may  eupfwi^e  that  an  inhibitorr  impulse  prodoMK 
Mldt  obaogca  in  the  cardiac  mtiscular  eubslance  lliM  tbu  upward  coa«triicti<ro 
lUDCnMs  areawisted  and  the  downward  dtaj-uptive  proceceee  checked,  wberebj- 
the  aettins  free  of  energy  ia  checked,  and  no  the  tieala  hiodered  or  Mopjvd. 
the  inhibitory  elfeci  being  followed  by  a  period  of  rebound  in  which  Hi* 
ravings  of  the  inhibited  period  are  spent  in  increased  action.  Coiti'enMir  «• 
ruay  suppose  that  an  anginentor  impuUe  hinders  the  anabolic,  and  nwist*  tht 
kuiabulic  cliiuijjes,  and  conversely  aUo,  when  it  hua  done  its  «i>rk,  Itaivm  tlir 
tiiMue  with  diuiiiiiithed  ciii>ital  manifested  bv  feebler  bi-atit  ur  hy  the  »h*rDe< 
of  the  |>nHer  to  beat.  Ami  .lirtiilarJy  in  th«  ca>e  nf  the  rcupimiory  eenin 
and  of  other  ti^ueii.  Whi-ii  we  have  to  xtudy  the  nrij^iiiiition  of  vtsua)  (»• 
pul»«»  in  the  rutiua  we  ahull  mine  upttu  a  view  ihni  a  wave  of  light  eaajr 
atfect  u'hni  we  tihall  call  a  vimial  Hulwtancc  dthcr  bv  promiitinjz  unabolie 
ooitatructivc  I'ban^tB  or  bv  incn»i.iiug  katabolic  deftrucltve  cluingM  accord 
iiig  to  it*  wave  lenp[h.  't'hen;  is  then  evideuoo,  to  a  certain  extent,  for  the 
view  oD  which  we  an;  dwelliug:  but.  without  discuHing  the  matter  nay  fur- 
ther, we  may  Kay  that  the  cum-e pi iun,  though  •uggvstivc,  haa  not  yet  bc«n 
demonMralrd,  and  to  lar  i-4in  unly  be  ipokem  of  as  probable. 

§  fiSO.  One  value  pcrbnps  of  »iich  n  view  lies  in  the  fact  that  it  warns  us 
against  awuming  that  n  nervous  impulse  can  only  produce  disnii>tive  kata- 
bulic  cbaiigc<  »iich  as  are  seen  in  muscular  contracliou  or  in  secretion.  The 
elTecte  of  alimulntinp  a  uerve  going  to  a  muacle  or  a  salivary  gland  arc  Mrik- 
ingand  obvious,  and  the  behavior  of  a  musclenra  ghuid  as  far  an  cuatrmclioa 
and  secretion  are  concerned  u,  within  certain  limits,  under  experimt-nlal  lyw- 
trol.  But  there  arc  certain  phenomena,  seen  chiefly  ia  the  connM;  of  dtwaar. 
and  lying,  to  a  very  small  extent  only,  withiu  the  control  of  ex [H-rinicnt. 
which  seem  to  show  that  the  central  nervous  ^steoi  govcntu  tlic  tncliibolic 
cbBDga,  the  nutrition,  not  only  uf  muscle  and  gland,  but  of  various  other 
tinun  in  a  deejier  and  more  general  way  than  that  of  smply  pnimoting  Inr 
hiitdering)  eontroctJoD  or  aecreiioo.  Thus.  m>  we  have  aeen  (§  J13),  when  tbe 
connection  betireeu  a  muscle  and  the  central  nervous  mteni  ii  Mvered,  tlie 
iDusole  eventually  wastes  and  lose*  it*  vitality ;  when  all  the  nerves  going  to 
the  submaxillary  gland  arc  severeil,  the  gland,  innti-ad  of  Wing,  lu  in  the 
nonual  condition,  tnterinitlingly  artivi.-  and  quieiteent,  pours  forth  u  continn- 
oun  "  paralytic  "  secretion  and  vvcotual  ly  dcgent^rat«»  and  wnslcs.  When  in 
a  nibbit  tbi:  iifih  nerve  U  divide<)  in  the  Hkull  the  lorn  of  sttnsation  in  tboae 
parta  of  the  face  of  which  it  in  the  Hens«)r}-  nerve  is  followed  by  nutritin 
ehanms.  Very  so<m,  wiihin  twentv-four  houns  the  come*  beootnee  doudr; 
and  tnis  is  the  precursor  of  an  inflammution  wbicli  luav  iavolve  the  wbiue 
eye  and  rnd  in  its  total  disorganixalion.  At  the  aaine  time  the  naaal  cbam- 
oen  ol  the  aide  o|>eriited  on  are  iutlaiiied,  and  very  frequently  nieen  make 
their  npprarnm-e  on  the  Hjw  and  gums.  Ami  similar  n^»ulls  hare  been  seen 
in  other  animals,  including  man.  If  the  i;|HYaiiun  he  conducted  in  a  vouug 
animal,  which  stibsc<]Ueotly  liveii  to  maiurity.  the  head  may  become  bilate- 


OV   NCTRITION'    IK    OENKRAL.  059 

nltv  UHjruoiutrwnUy.  u  shoiro  MprvMilljr  by  tbc  «kull.  Again,  division  or 
botn  vigoi  ncrvci  is  verir  apt  cu  ite  liitlowed  by  iiiflnroiiwtion  of  both  lungs, 
b;  buy  d«M<MnUiiHi  uf  itu)  heart,  luii)  m  li/  ilentli. 

In  MVtttnl  of  tbeM  inttaucca  tbc  elfod  n  a,  niixot)  miu,  nnd  the  nroblciu 
a>isplieat«d.  Thui,  in  Um  ea«c  of  <Iivtfloii  of  ibe  fifth  tierv«,  aoeiiig  how 
Miait*i»tniclurv  lh«  sty*  Miimd  bow  carofullv  it  >*  proUicMd  byUi*  mei-hu- 
of  tbo  ej'elids  >n<l  Uuira.it  aeenu  rcasonnW  to  suppow  tliiu  Um  inSani- 


I 


auion  ia  qittstion  tnigbt  siianly  be  tb«  roault  of  tbe  irrittition  cauawl  by 
Jul  «od  oootaciwitli  fotvigii  t>ixli«»,  lo  which  thecyo,  no  lon^r  (guided  nnd 
iMXttecUd  byMOMidons,  tiictv  b«ing  destroyed  by  tlie  wclion  of  the  nerve, 
OMUie  «ub}«ct.  In  (li«  same  irny  the  ulcere  od  the  llpe  and  fpiiaa  nii;;hl  be 
•xpluDed  aa  injuries  ioflielcd  by  tho  teeth  on  thnec  striicturee  ia  their  iiiscii- 
•ibve  condition.  And  aome  obaervora  maintain  that  the  indunaatwn  of  tlie 
«yt  may  he  greatly  leneoed  or  altogeiber  proveuted  if  the  orgaa  be  earefully 
«aftna  up.  aud  in  nil  ponible  ways  protected  ftom  the  irritsdnji  inllueuoM 
of  fbrti^  bodiea.  Other  ohservers.  bove\-er.  have  foiled  to  prevent  the  in- 
AamiiMtMa  in  spite  of  ererv  care.  So,  also,  the  iDflaniDuitioa  of  the  lungs 
Ihltovinft  upon  division  of  both  vu^ua  nerve*  aeeina  to  be  due,  not  to  any 
direct  nuiriiive  action  of  tlie  puluiounry  braiichea  of  the  vsgud  un  the  pul- 
Btaaarv  tia&oe,  but  to  food  accu inula tiujc  in  tbe  pharynx,  owing  to  tbe  parol- 
yM  of  the  ceaopbsguB  and  larynx,  and  then  piuuinj^  into  tlie  air  paiaagat. 
and  en  sMtJng  up  iuUammalion.  Death  ia  ihttie  ciunn  is,  uoreorer,  often  tbe 
dnpla  nmnlt  of  inanition  caiJ4u(I  by  tite  parulyia  of  llie  ossophaguit  allowing 
no  li>od  to  rv«oh  (he  •toinaeli.  The  phi-nomi;iiii  of  (he  paralytii!  aucretiou  of 
Mitva  an  abo  of  a  coinj>li('jklcd  nntiiru. 

Bnt,  even  without  iiiauling  on  xnch  inatanuta  a»  the  above,  various  other 
phsDunwoa  of  disMae  seem  to  iudicaic  :iuch  an  influence  of  ibe  nervous 
■nii-ni  on  niilritiim  lui  we  nr<'  di^-iiwing.  As  i^iamplnf  wi;  might  meotiou 
lae  rapid  and, peculiar  dcgcniTntimi  of  and  lonof  cvnlraclility  in  ihu  ■kvletAl 
■nuwlea  in  oertain  nlfcctiuns  of  the  apinnl  cord,  the  changes  in  tho  iniuclos 
beiog  nure  rapid  and  prof^iuud  ilian  in  the  nervea;  the  phenomeua  of  bed- 
auns^  especially  the  so-called  acute  hedaores  of  cet«bi«l  apoplexy ;  soue  at 
least  of  the  caaea  of  veeicnl  afll?ctioua  attendant  on  spinal  or  oereMal  diaeans 
••r  injuftw;  the  more  rapid  atrophy  and  lossof  contractility  in  nosoles  which 
MIow  upon  contaaioas  of  nerves  aa  compared  wllh  the  e&ecia  of  aimpte  sec- 
tion of  nerves:  the  occurrence  of  certain  eruptiona.  such  ai  lichen,  zona, 
eethyino.  etc.,  in  various  spinal  or  cerebral  diseases,  aud  indeed  the  (renerat 
pbenomena,  and  especially  the  toiMgraphy  of  (he  eruption,  of  a  lan^e  number 
of  oulaoeous  diseases.  Lastly,  nut  not  leaat,  we  might  ()uote  the  general 
proeeas  of  inflammation.  These  are  eiamplat  of  disordered  nutrition.  To 
than  wo  niigfal  add  as  ioslanoea  of  altered  but  yet  orderly  nutrition  tbe 
msMtrkable  oonnections  observed  between  ohanges  in  tbe  form  of  tbe  fiogera 
and  gn'Wifa  »f  tlie  uuls  aud  Iiaira,  aud  oertain  interual  malailiee,  such,  lor 
iuatancf.  as  the  "  clubbed  tiugers "  of  pbthisieal  and  otiter  patients,  and  the 
hke.  Wc  luijilil aliti)  call  attention  to  the  influence  of  light  on  the  uutitiou 
uf  animals.  TlkC  uxiwriooce  of  Mind  people  aud  bliutf  animals  indicates 
soma  special  coonection  iMiwtwa  visual  seaiadons  and  tlie  nutrition  of  tbe 
skin ;  and  this  can  hardly  In  other  than  a  nervous  oounection.  The  elfeeta 
of  prolonged  darkncM  on  nuiritiou  tn  geiK-rul  and  tlw  exjieri mental  results 
wbMth  abow  tluil  the  total  wclabollam  or  the  liodv  is  influencod  by  light,  also 
aiigjast  some  nervous  action.  Tbe  iufluonca  of  oold  again  in  dolenniotng 
the  ipvwth  of  hair  points  in  the  an'nc  direction. 

Jinking  nvorr  allonrAuce  for  tlw  inicf^-cntioo  of  bcl  in  tho  praductiiHi  of 
the  i>lieiiiKnoita'i]uot«d  alM>v«  of  such  coiuin>ia  aotEoos  of  the  nervous  system 
as  are  already  well  known  to  us.  such  as  vasomotor  changes,  making  ever; 


660 


-VUTHITION. 


nllownme  for  tlic  coii!»c(iiii?iipi'''  of  tliD  fiiilai*  or  bltmino*  of  i«n>Mtron  »t 
tbf  nliwncr  nf  ilioiw  bcm-tidnl  nflcr  mails  of  musciiliir  mtivily  which  dv 
potnk<I  out  ill  S  Sii,  n,xHiKiii/.iiig  morcoTrr  lh»t  cliiiii|n«  in  one  (>f)t)in  rm; 
aflii-t  tht  oinilitinn  of  (ithpr  [)i»t)inL  nrgnns  bv  (-tmngvi  jndiiccil  in  iIjc  com- 

Scwition  nr  ijualities  of  the  blond,  tliirri.-  »lill  ipmnins  ■  rcridnr  m  birh  xtiM  . 
wtiiK-'lly  to  nuiot  (o  the  conchi^inn  tlinl  ihc  intlueiirc  of  ihv  ncrvoii«  crEtciii 
ia  not  limited  toeiiih  ohnngtv  of  th<-  nntEcli^  ni  belong  to  the  prodadion  of 
contrnctionK  or  the  generation  of  heal,  but  benrs  on  iW  whofe  nutrition  of 
the  muecle.  i^imilnr  eonfi deration 8  lend  us  nlsn  to  conclude  tliat  lb«>  infiu- 
pnco  of  the  nervoiu  ^vMetn  benre  (in  the  whole  DUlrilioD  of  the  glsudf,  oftbe 
bloodTeMcls,  of  the  «^in  sod  of  the  conDeelire  tiGCue  in  general,  in  ftctoF 
nearly  the  whole  body. 

Such  an  iiifluenee  of  the  nervous  eyMem  hae  often  Iwen  spoken  aa  "Iro- 
phtc;"  and  the  term  hae  of^eD  been  u«cd  aa  if  the  growth  and  nourvhiiwH 
of  a  liKue  weie  the  result  of  nervous  action,  or,  at  all  ereuta,  could  not  b 
complete  niihout  the  in terveotioQ  of  nervous  impulsn.  Hence,  in  ihia  »ie», 
the  c-on»e([u«ucea  follow  iuf{  umn  section  of  tbc  KAb  nerressregaided  osdut 
to  the  falling  away  of  "iTopIiic"  influcnceii.  Such  a  view  ha*.  howe%'er,  w 
sound  ba^9.  All  biological  Mudie»  tmch  tiii  that  the  )(Ti>«ih.  repur  end 
reproduction  of  livinc  subslaiice  may  go  on  (juite  inilejiriidcutlr  of  any  neh 
vous  Bj'Blcm.  The  while  l>lo(.d-corjiui>cte>  so  tbruu^ch  ihi-ir  cydrs  uumotMd 
by  nerroue  inipult>c«,  and  the  niilntion  of  the  nervous  nvstem  ilM'lf  caaiwt 
bedepc^niliiit  iiu  thenclion  <if  that  xjNieninn  iliclf.  All  tKnt  is  n'ally  iiewled 
to  explain  there  phononiciia  Ex  an  acceptniKi;  of  tbc  view  thnt  n  nervoM 
impulse  may  modify  ihi*  nielaholic  cvimiIh  of  other  lovun*  than  mu»cl<-*  awl 
glnniin.  mid  may  modify  ihcm  in  various  viayv ;  and  further,  (bat  the  nulrilioo 
of  i-ach  tiMue  i»  in  thu  rumiilex  animal  body  »o  arranged  to  nfv^.  the  con- 
stantly recurring  influruocH  Drought  to  bear  on  it  by  th«  Dcrvous  eyatcn. 
that,  when  those  infiueuccs  are  permanently  withdrawn,  it  is  ibrown  out  of 
ctiuilibrium ;  its  molecular  procesect>,  so  lorncak,  then  run  loose,  since  the  bit 
hoN  been  removed  from  their  mouths.  And  as  our  knowledf^  of  metabolic 
processes  on  the  one  hand  and  of  the  actions  of  tbe  nervous  systeni  un  tbe 
other  hand  increases,  ihne  snppoeilions  become  more  and  wore  reasoaable. 


Oy  Diet. 

fftSl.  An  OTtlinary  man  living  an  otdinary  life  will  need  for  tbe  tnaio- 
teuunce  of  vigorous  health  a  ci^rtaiu  amount  of  food  of*  certain  kind  ;  this 
we  may  take  as  a  normal  dier 

Preaumiug  that  the  experience  of  mun  has  led  him  to  adopt  what  is  cond 
for  biro,  we  may  aRrertain  apjiroximalely  iho  normal  diet  by  mean*  of  the 
statistical  method,  by  cxamitiing  the  nature  and  amount  of  the  daily  food  of 
a  very  large  number  of  individuals.  The  most  valuable  data  for  this  ptirptce 
are  iIicm:  gained  by  inqtiirin  among  pertons  who  choc«c  their  own  food  ;  (be 
mnll*  gamed  frem  Ihc  diels  used  in  prisons  or  other  ineiilutions,  or  uaong 
bc(li4'»  of  men  such  as  the  army,  though  more  leadily  arrived  si.  are  open  to 
the  Direction  thnt  the  diets  in  queslioti  are  determined  in  part  by  (be  theo- 
retical opinions  of  those  whoso  duly  it  is  to  fix  the  diet.  Pnlting  together 
lh«  various  statistical  reeults  llius  obtained,  and  selecting  tbe  quantities 
which  Fcim  to  be  most  commonly  used  rather  than  attempting  to  strike  a 
btrict  average  or  take  a  strict  mean,  wo  Bud  that  in  an  ortiinary  diet  for  the 
Inenlv-four  boun  the  several  food-itu^an-: — 


I 


Tin  toul  (itvtuUblo) pottntjnl  owrgv  or  the  lom-r  n:iniit«  u  2610,  of  the 
h\^ttt3i0!»  (kilogiuoinMMlcgrec)  cnlorim,  cnlciiUled,  io  rixmi]  numbur*,  on 
Um  i]«U  <if  ^-ViS,  With  «jch  it  aUtistiwl  diet  nc  may  compAn:  mi  ozperi* 
fBtntnl  A'lH.  thill  u  to  mj  a  tlivt  arrivci)  at  ihrmigh  n  aonee  of  trials  on  nn 
in«l!vi(fonl  iimii  whose  body  might  be  taken  to  bo  an  nvcrago  one.  that  iliot 
briu);  fimitidvred  a  normal  one  in  which  the  body,  maiDUioio;;  visorwu 
btmltfa,  ndtbcr  ^inol  nor  lutt  id  wvight,  and  reouioed,  moreover,  in  iiilro- 
niioaav<i|iiilibniim  wiihthi-  nitrogen  of  the  egwta  equal  to  that  of  the  ingcsla. 
To  make  sure  that  under  HUch  n  diet  iho  boily  vas  remainin;;  of  thi>  same 
composition,  there  itught  to  be  evidence  of  a  earboD  ci(iiilibriu(n  abo, 
oUurwiw  during  the  period  of  the  exfieriiuent  fat  mi^hl  ba  roptaoet)  by 
wtUa- (mx  f 'y£'2) ;  but  this  is  uulikely,  aud  we  raay  therefore  aooept  thie 
DMihod  as  a  fair  one.  It  baa  ffivea  in  the  handa  of  two  difTurent  obeerren 
the  folltiwiut;  tuoiewhat  dilTi^rviU  Ksulia,  the  diet  A  beioe  that  alreodv  qiio(«d 

A  U 

Prouidii         .        • lOOgramniM  t18 

K»U .        .    "lOO       "  66 

Cubohrdntci V40       "        MX) 

Sail* as     "       — 

Water 2600       '■  — 

Tli«  total  I  available)  pot«otia]  enenry  b  reepectfully  2:Il<>aml  34)25  caloriea. 
(In  the  whole,  the  dieU  gained  by  tlie  two  method*  iitfr«e  very  lur^Iy. 
To  put  doKu  a  single  column  of  figures  as  "  Ok  normal  diet "  would  be  to 
uSxi  »  VMU  and  tulunve  accuroeA-.  Jf  we  deure,  for  thcoretleal  purpuoea, 
taarl«ci  moio  one  aetof  figurw  rather  than  others,  w«mi>;hi  bu  influenced  by 
th*  coDsidentions  that  the  lower  amount  of  pn)t«ids  In  the  ex [leri mental  diet 
wa*  nearer  tin-  mark  than  the  bij^h^r  ojnount  of  some  of  the  atatliKical  dicla, 
and  farther  that,  wberv  omI  in  not  of  moment  the  inih»iiiuii»ti  of  fat  for  on 
•sens  of  cufaoltydnum  In  dowinible.  Wc  should  he  thun  \cd  t«i  take  the 
txperimenial  diet  A  a*  «ii  iImi  whole  the  best  or  most  "  normal  "  one,  and  that 
■I  the  uni:  which  nccmplo]<-d  in  the  caloulationsoTS''''-^*-  It  will  Ixiobncrvcd 
that  the  potential  enetuy  of  thU  diet  i*  Um  than  that  of  any  of  the  others, 
am),  as  we  said  while  then  xpcaking  of  it,  may  bo  con»ider«d  low :  but  tbors 
was  no  evidence  thai  it  was  insuHicicnt.  Still,  it  miiat  be  rememboreil  that 
Dthber  it  DOT  nnr  uf  tbo  ixhc^ni  is  to  be  regarded  iw  divtinctty  proved  to  be 
the  m>l  normal  diet.  Against  the  eiperimi^ulal  diet  we  mny  ur^o  that  the 
number  of  ex|>eriment3  have  been  ftw,  and  conducted  on  a  few  individuals 
only  at  most,  and  that  a  larger  number  of  etperimeais.  with  a  variety  of 
eombinations  of  diflercnl  amounts  of  the  several  food  »tuflii.  might  lewd  to  a 
di&rvnt  f«snlt;  tliat  for  iiislanoe,  with  certain  ani'junta  of  fats  and  carbo- 
Iiydratee,  the  atnouni  of  proteid  need»I  to  mainiain  hcalihy  bodily  e<|uili- 
tiriuRi,  including  ntlrogenoUH  e<|Uilibrium,  might  be  reduced  much  below  the 
Inn  grammea,  especially  if  particular  kinds  of  proteid^  fat  or  carbohydrates 
were  used,  and  Mitecial  aiieniion  (see  $527)  were  paid  U>  the  aalta.  And, 
indeed,  a  considernble  number  of  oboervalwna  haw  been  made  tending  to 
rbriw  thai  a  roan  of  average  siae  and  weight  may  ctmtinue  in  nilrogenoiu 


i 


NV  TUITION. 


equilibrium  bdcI  in  good  ht-nltli  wiih  a  dnilv  mitriit  nf  miirh  lew  thnn 
emnmcs  protcid,  wiili   ii#  littlo  m  40  grnrixnco  fi>r  vximiplr.     To  tfii» 
ihnll   have  to  refer  in  cjirnkiiig  of  n  vrgHiibJo  dit-t.     Apiinvl  llu-  prniiait 
<licl,  on  the  other  hiind,  we  mity  urge  ihiil  instind  is  nut  nii  unerring  gut 
and  that  the  elioke  of  a  diet  is  detcrmintrtl  by  maoy  Other  cimitneuince»  thiin 
the  phveioloLnen  I  value  of  the  food. 

$  BSii!.  TnKing,  however,  oonio  «tich  diet  ab  the  above  (o  be  tlie  nppmsi- 
mitel;  Irue  Dormal   diet,  v.-«  miiy  cidl   iiliention  lo  the  fnet  that   the  uonital  ^ 
diet  it  made  up  of  eitch  of  the  three  great  Ibotl-stu^,  carbohydrates  being  ia,^ 
escefs.     We  may  here  remark  incidcti tally  thai  l)i«  diets  of  both  the  car~-. 
iiivora  niid  herbivora  ngree  with  that  of  omnivora  in  eoniainiDg  all  lhre« 
food'»tul& :  they  difler  froni  each  other  ss  to  the  relative  pniporlions  ouly. 
Ai  we  have  seen,  the  hoiiy  may  be  mninlaiQed  in  ei)uilibriuin  on  proteid  (mm/ 
aloue;  but  an  eiclusively  proieid  diet  is  pot  only  bou){ht  dearly  in  (In 
ID  ark  el,  but  also  [laid  fur  dearly  within  ihe  economy;  we  are,  of  courw. 
Duw  speaking  of  man.     To  obtain  the  necesaary  carbon  oul  of  the  carbni 
nioiely  of  pruieiduniiecEi'sary  labor  is  thrown  on  tbeeconomy,  and  the  tntcm 
tend*  to  bet-onie  blocked  wiih  the  aniiiles  ami  other  uitroscnous  waMe  arittng 
out  of  Ibe  nitrogen  moiety  simply  thrown  olF  U>  secure  the  carbon. 

Fata  and  carbohydrnie«  arc  mneh  more  akin  to  each  other  than  b  ■.•ither 
to  i>roteid ;  and  if.  »n  the  one  bauil.  as  (§  Hi'.i)  leenia  pdMibk-  or  even  prob- 
able, the  fat  of  the  tbod  and  of  the  l>ody  i*  L-onverled  Iniu  Migar  either  un 
it«  way  to  hei-imie  bnilt  up  into  the  tisttue,  or  in  the  <H>urtt-  uf  tin-  chnitgM 
taking  p1ac<-  uutnide  ihc  reul  living  framework  of  the  tiMue  by  ivhich  it  ti 
rcdtieril  t<>  cirlionic  acid,  ami  that,  ou  the  other  hand,  enrhobydnitn  <^D 
fiirnioh  the-  fat  whono  prt^w-nw  in  the  body  ii  nccMWry,  we  might  ex|>cct  that 
enrbohydrnlo  nWe  without  fat  might  with  pmteid  form  a  nonnnl  diet.  Itiit 
on  this  point  exiurience  i.->  probably  to  be  Inist^'d ;  and  wc  niny  iiilvr  thai  tn 
every  normal  diet  somu  I'at  at  lewt  munt  be  added  ki  ihu  starches  and  the 
mgara. 

The  advantage  of  this  mixture  is  probably  felt  while  ibe  food  ia  as  ret 
within  the  alimentary  eaiinl.  What  we  hari;  learned  eonceniing  digeotmn 
leads  UB  to  reganl  it  ns  a  coinpliented  procew,  and  we  cannot  readily  iiiiauiDe 
that  the  proteolytic,  aniylolvlic,  and  adipolytio  changes  nin  their  several 
flOlinea,  especial Iv  in  ibeaiuallaiid  large  inlcMtine,  apart  from  and  irrai{ie<-iire 
of  eacfa  other.  We  are  rather  led  to  etippoee  that  the  aceompaoimL^ni  nf  «»« 
Bet  of  cliangetf,  in  some  indirect  manner,  favors  the  others  ;  and  it  is  for  tiial 
reason  probably  tliat  we  take  our  food  mulb  not  separati^ly,  but  mixed  in 
tbe  same  meal,  often  on  the  swoe  plate,  and  even  m  the  aame  miiuibful. 
But  apart  fmm  this  the  two  food-stutl'e,  faiH,  and  carbohydratea  iuiim  play 
different  i)art»  in  the  ecunomy.  ao  that  the  one  r-aunot  be  wholly  subMilutetJ 
for  lite  other;  nml  though,  beyond  the  fact  tluil  the  one  soeins  to  be  a  sourm 
of  energy  and  iho  other  not,  we  do  nut  ati  yet  know  the  true  phrviolngical 
func-tJon  of  the  hydrogen  of  the  fat  as  conifiarcd  with  that  of  tn«  ditll-renily 
ditpfwed  hydrogen  of  Ine  carlmhydraie,  we  may  pcrlui]»  infer  that  the  diHi'r* 
tacD  i>r  use  within  the  body  of  thu  two  kiiidi>  of  tiiod-Htuflii  bean  n<bt  *>i  mudi 
on  iboir  ultimate  couxumplion  to  supply  envrg}',  aa  od  llie  vnriMia  c>>nipliaitrd 
prooesM*  which  they  tindvrgo  and  nrrangrmcnis  in  which  they  tiike  {uul 
ueforc  the  end  of  their  work  in  reach^-d.  We  have  had  a  bint  that  (be 
carhohydraic  more  rapidly  Mipplies  iho  beat-giving  mi-laholi«ni  than  does 
the  fat :  and  lhi»  suggnts  an  ndvanlago  to  the  economy  in  receiving  daily  B 
certain  pinion  of  the  more  tanly  material,  while  at  the  sarao  time  il  may 
be  taken  lo  mean  that  the  tat  before  it  is  nM-^l  to  give  rise  lo  energy  has  lir>l 
lo  be  coiiverteil  into  tiugar.  and  so  takes  more  time  in  itfi  work. 

Tire  main  carbubydrale  of  every  <liet  k  starch,  and  as  far  aa  we  con  leara 


ox    UIBT. 


608 


I 


■t  foarat.  tli«  »lnM)  vhich  is  to  lnrg«  ii  pnrt  of  tbu  crrritU  am)  vegelnblcs 
nuaiBCit  by  man  is  Ihv  mrid  boily  in  all  nfthcm:  tor  the  ii»c  of  lurh  bixlif* 
M  iDnlin  t*  ra  inwgniticont  ilint  it  may  \k  nc-el«ct«!.  Jlnii,  howi^var,  cou- 
HimM  DO  i]>ctinsi<lera)>Ic  ijiianiiiy  of  suesr,  chiotly  cftne  sugar.  Since  tbe 
•tarch  of  a  meal  does  not  become  available  for  the  economy  until  it  has  been 
eonvtrtei)  into  sugar,  we  lui^hc  be  inelined  to  infer  that  it  iras  a  nistler  of 
lixliAercDce  ulictber  Uie  earbohy<lrBte  at'  b  diet  were  supplied  ns  starcb  or 
asHii^r.  But  besides  tJw  fact  that  anr  \artfe  deAeit  of  starcb  in  a  diet 
might  seriously  interfere  nith  the  general  couree  of  diKe^tiou,  eepeoially  if  aa 
ur^d  above  the  wreral  digeslive  proctnea  are  more  ur  leas  oepeadent  on 
«adi  otber.  it  muitt  be  remi-mbered  Ihnt  ihe  au^ar  into  vrhich  starch  is 
diBDsvd  bj  ditcestioi)  i*  muhotie,  while  cane  suKar  appears  to  he  either 
ibsoned  >b  cane  »u(:Br  or  at  moot  only  inverted.  Miire>)ver.  if  our  labora- 
lorr  experiments  truly  rejimeiit  the  dig««ti<)ii  tnkin^  f>tac«  iu  the  living 
body,  ooly  part  of  the  slarcb,  S  198,  la  eliangod  into  maltitfe,  irbile  pari 
bccoDwa  mote  variety  <if  dextrine  or  of  starch.  Our  kiionledfce  of  HUfcare 
aad  of  tbdr  fate  in  the  eoooomy  I*  too  impi^rfoct  for  us  to  be  able  l»  aiate 
Ike  eflecM  on  the  Uxly  of  dignted  Mnrcli  as  cnrnmrcd  wilh  tlimte  of  ease 
•ugnr  or  millc  sugar ;  but  tlint  tlio»<>  are  or  may  bo  aifforciit  io  shown  br  the 
exfMirictMM  of  luedicnl  prii4.-t)(v.  In  many  <-!utct  the  total  effect  on  tlielioilv 
of  a  diet  fnim  which  uini;  sugar  is  as  mueh  n«  po«<ibl?  rliminiiK^l.  ihough 
atarch  be  allonvil,  is  rer^-  diHerent  from  that  ol  <ino  of  which  c<u»e  sugar 
JbmM  an  appreciable  |>art. 

Coaoeniitig  cellnlii»e.  which  in  ber4>ivora  Bpi)«ars  certAinlr  to  terv«asa 
Mara  of  encrey  and  lo  he  a  real  foixl-stulf.  otir  knowledge  will  not  allow  Ui 
to  decide  whether  it  has  any  !>peciiil  iitan  of  its  onn.  or  vfaelhcr  the  bo<ly  is 
eimply  led  to  nlilize  and  make  ihe  best  of  what  is  a  neccemry  acci>m|iani- 
ment  <>{  the  starch  of  vegetable  food. 

Cunoeniiiig  tbe  salt«  prtv^i-ul  in  a  diet,  we  need  onlv  re|»eiit  irhat  was  said 
io  S  527,  that  tlieae.  th<iuj;li  iiifurcliug  of  ibemaelv<»  little  or  do  energy,  are 
aaegeeotial  a  part  of  a  din  n»  tbe  enervT-givinn  food -stutb.  inasmuch  aa  they 
in  sun>e  way  or  other  direct  mrlab>>)Um  and  the  diriiribution  of  energy. 
And  this  is  true  not  ouIt  of  llic  innrjcimii-  Milincf,  Mich  aa  chlorides  and 
pbiapbatea.  but  aba  of  \bt  so-calliil  extrnctivcu.  M  ve  have  toea,  the 
pmence  of  ilxve  bodin.  both  ihe  oimplt-r  inorganic  and  ilie  more  comnlex 
organic  snlu.  in  the  blu»d  or  in  the  cztni-TBseular  juim  or  lymph  of  titc 
linuet  i«  owvntinl  to  or  diivcls  or  nimlifiu  the  metabolic  aetii-iir  of  the  tvr- 
oral  ti«u«».  The  iM-ncHeiitl  vtRs.'t>,  as  compoDents  of  »|xt'ial  iVwtf,  of  such 
ihinn  as  beef  ten  and  intat  extract,  whkn  consiit  chii-Hy  nf  nails  and  ex- 
IfaeuTA,  with  »  very  sninll  Qiiiintitr  of  albumose  or  ulht'r  forms  nf  priHetd, 
and  the  rlTecIs  either  betietkiol  or  cfeleteriou*  of  drug:*,  both  turn  in  cominoD 
Dpiiii  their  taking  a  pnrt  of  aome  kind  or  other  in.  it  may  be  upon,  their  in- 
(•rfcrvnee  wilh  nieUiboIio  procenea  Tlie  salts  and  cxttuctivc  of  a  diet  may 
be  looked  iii»ii  aa  necessary  daily  medicioes.  an<l  a  medicine  as  a  mure  or 
lev  exlnortf  inary  variittion  in  these  elemeota  of  a  diet. 

Alcohol,  to  the  use  of  nbicli  aa  a  eompoocnt  of  an  ordinary  diet  spedal 
iatemt  fur  various  reaaons  attaches,  (Monies  in  tliia  class.  For  tbnngh  ob- 
■erraiiuiu  show  that  the  greater  part  of  n  nvnderate  dose  of  alcohol  i*  oxi- 
tlbcd  within  the  body,  iin<l  mi  lem-^  ai  a  30^.irce  of  ener^v,  man  \im  reeourve 
to  alcohol  n»i  far  the  ininuic  qituuiity  of  i-i)«r)Ey  whieh  is  supplied  by  itself, 
but  f»r  its  jHrniTfiil  inlluence  on  the  distriboiion  of  the  ener^  fliruitbed  by 
other  things.  That  inllucnee  is  a  vcr%-  complex  iioc  an<i  cannot  be  fully  di«> 
mannd  here.  It  is  ■taii.il  that  imHleraia  or  amall  doaca  of  aludiol  diiuiiiiah 
the  consumption  of  oxyctn  ami  pnnluction  of  carbonic  acid,  that  is  to  aay, 
diminish  tbe  total  rtsult  of  the  nw-ulMilism  of  the  boily,  irbtle  largvr  biK 


6S4 


IfUTRITlOX. 


Mill  not  intoxicating  liwr*  have  n  cxniimrr  ellWit  ukd  inerWM  tba 
in«tnboli«iu.    Bill  Mich  n  »uit«iiiciu  iitlbnis  no  nund  bwit  for  Rn^eoDcli 
lU  li>  th(>  g«DoniI  physiological  etlvct  of  ulcohot,  or  lU  Ui  iU  uwifulntM 
pnrt  nf  All  ordinsrv  <tiet ;  it  doos  not  justilS'  such  a  ci>nolii«ioi),  for  f  Kiimfik, 
U  thnt  ulcuholic  driiike,  tnkvu  in  nioiiermtioii.  liy  ilimini'hiii;;  mvUtbiiliiiB 
econoRiiz*  lb«  rcaaurcc^  of  the  body.     Tile  promiucnt  i>hyi;i->Ii>giciil  prohlvm 
of  dietetics  is  oot  either  to  increiuc  or  diminish  the  tiM>lii6'>1tHin  of  llio  body, 
but  to  direct  thnl  nielnbolisni  into  proper  chauoels:  and  whelbpr  in  each 
particular  case  a  ^i^^Q  <l*'s^  of  alcohol  gives  a  n;;h(  or  a  wrong  turn  lo  tW 
pbysMJogical  procawcs  of  the  body,  depeiidi  on  the  particubir  circutDBtaooc^ 
of  the  caae.     For  the  action  of  all  these  biidies  of  which  ire  are  now  speak- 
ing, in  contrast  with  the  aclious  of  the  food-slulTii  proper,  ia  not  only  comptex 
but  variable;  do  cuniplex  and  variable  that  simple  ex|)erience  is  at  nreaear 
a  nion^  truHtworthy  ftuide  than  spoculative  physiology.     We  may  odd  tlitl 
thu  physiological  action  of  alcoholic  drinks  is  still  further  complicated  bf 
tbe  hiut,  lliat  niinit  ^iich  driakit  cuntain.  liesiilea  etbylic  alcohol,  various  oUttr 
allied  HiibMt«iict«.  whoie  iictiou  i^  ovt-n  more  potent  than  lliat  of  the  cthyliv 
alcohol  itioir,  anil  wIiiik-  pr^ciico  very  ninrke<lly  dvierniiiiei  the  total  eOcct 
of  tbi:  drink,     t^uch  arl.icli^  of  diet  oh  leu  and  oolfee  txaiid  upon  mry  mack 
the  same  foiitiii);  ELI  ulcohid. 

The  qniintiLy  of  Moid  which  a  man  drinks  or  iihonld  drink  daily,  or  mar* 
eorreotly  the  ([unnlily  of  water  which  be  shmiUl  daily  add  to  the  dry  xjlidl 
of  hU  diet,  niuirt  var^  widely  acconliiig  to  clrcuiastttnoi!.  It  will  differ  ac- 
cording w  he  is  penpirin^  ijrcatly  or  not,  according  to  the  nature  of  the  dry 
solids  of  the  diet,  whether  Iiir^cly  ciirhi]hydnit«  or  not.  and  so  on.  A  lower 
limit,  below  which  excretion  is  impelled,  and  a  higher  limit,  nbore  whicb 
digestion  and  metaboHsin  are  injuriously  atfoctod,  probably  exist;  but  we 
have  OS  yet  no  adequate  data  which  will  enable  us  to  Ox  cither  of  then. 

§  65$.  Ill  the  selection  of  articles  of  food  to  supply  the  food-etuH*  and 
other  cousiituents  of  a  normal  diet,  regard  must,  of  course,  he  bail  in  the 
first  place  to  the  amount  of  potential  enertiy  present  in  the  maUrial.  The 
articled  chowu  f»r  the  daily  lore  must  contain  between  them  so  much  pro- 
idd,  fat,  and  carbobydraie  repreunting  so  much  av-ailable  energy.  But  it 
b  no  IcM  iniporLant  to  secure  tnal  the  energy  potential  in  llie  material  should 
be  really  available  for  the  econoiny.  Tht^  uniierial  niu-it  have  such  •lualilJM 
that  it  in  digested  within  the  BUmt.-niary  canal,  and  further  that  ila  digMtJOB 
and  alworption  do  not  give  rise  to  iniuble  either  in  thi;  nlimeniary  auaal  or 
in  tluil  socondarv  digestion  ciirrieil  on  bv  means  of  the  various  metabolic 
OWnta  which  we  nave  diiicu^'wd  in  prermiiinit  seclioDN.  A  nuilly  nutritious 
(ubetanoo  is  one  which  not  only  coutaliii  in  itself  an  luleiiiiulp  supply  of 
mvgy,  but  is  of  such  a  nature  that  its  nui^rgy  can  W  approDriatcd  by  the 
•coBomr  witb  ease,  or  iit  least  with  a»  little  Ironbto  as  |>os*i»le.  We  hare 
approximate  data  lor  (ktermlning  how  tisr  an  estimate  of  the  relative  tise- 
fiiUMM  of  various  articles  of  food  must  be  corrected,  bv  allowing  for  tbe  pro- 
portioa  of  each  which  after  au  ordinary  meal  merely  panes  through  the 
alimentary  canal,  and  the  energy  of  which  is  not  in  aov  way  available  for 
the  hodv's  use.  Thus,  a  niimoor  of  oluervations  <»rrie<l  out  on  healthy  in- 
dividuals gave,  in  (he  cose  of  the  following  articles  of  food,  the  following 
figures  M  the  perceniagc.  rockoncd  in  each  case  on  dry  material,  wfaien 
0oald  be  recovered  from  the  leoee,  and  was,  tlierefore,  not  digeeted  and  not 
used  by  the  body:  Meat,  0  per  cent;  e^gs,  5  per  cenL;  milk,  '■*  per  cent-: 
bread  (white).  4  per  cent.:  Mack  brendr  !•>  per  cent. ;  rice,  4  per  cenL; 
moccaroni.  4  per  oent.;  maice,  7  pei'  cent.:  pens,  !■  per  ceul. ;  potat*i«s,  11 
per  cent.  It  miisi,  however,  be  remembci^il  (hat  the  nclual  correction  to  bt 
made  in  any  cose  will  depend  on  the  mode  ol'  cooking  of  the  lusiorial.  ui 


ox    blKT. 


Ill*  dtknvUr  of  tbe  iumI  of  which  it  forms  jiiirt,  tuul  on  the  iitdiviiJiiiil 
ofabiliUw  of  tho  cvDiumcr,  the  lutlcr  too  v*rying  under  diffeTieat  circuiii- 

tfUIOM. 

Thf  nbovo  nfen  (d  what  nuty  be  atll«]  roticb  dij^eetibility,  but  bcniile*  th» 
\h«n  »re  other  circuButaaoee  tii  be  owwdefed.  The  mms  food-fltud'  iii  two 
mrticln  of  food,  ihoogh  aettiallr  di)Nflted,  (hat  U  to  say  taken  up  br  ihn 
Mlimeotan,-  canal,  loay,  ev«0  while  still  within  the  alimeDtary  canal,  undcr^ 
cbang«  in  th«  one  case  diBerinK  from  those  in  tbe  other.  A  proteid  may  for 
iiMM>c«  in  oi>e  caae  tend  to  be  ontireljr  converted  into  peptone,  or  to  brvak 
up  into  leucin.  etc.,  or  in  other  caaea  to  undej)[u  other  ohsn^ ;  and  a  carbo- 
bfdnite  niay  in  one  case  be  absorbed  lu  malltue,  and  in  another  give  rise  to 
Uetie  acid.  Indeed,  when  we  speak  uf  iIil-  di^teHibility  or  the  iudtj^tibility 
of  thb  or  that  article  of  food,  we  do  not  in  uuuij  cum*  so  much  mean  tlie 
(elatire  amouul  of  the  sulutauce  taken  up  in  some  way  or  olher  by  tlw 
lUoMBtary  canal,  a^  the  chamcler*  advantageous  or  otherwise  of  the  cbaoj;^ 
whlsb  it  undeixoei  in  Wini;  so  taken  up. 

Hvace  the  purely  fhomioal  staiument  of  the  amnunl  of  pDt^niiul  euerKy 
imaent  in  an  article  of  food  is  DO  snf<^  guide  <>f  ihr  jihyiiioliigiciil  vulue  of  the 
MbsCanoc.  A  chunk  of  diecac  viand*  very  high  »n,  ^norally  at  tbe  top  of, 
•  table  uf  the  nutritive  value  of  articUsi  of  food  drawn  up  on  exclusively 
obtaUcal  principUv,  according;  t>i  the  nnits  of  sne^y  proscnt  in  n  unit  uf  the 
material:  but  it  ■•  verv  low  down  in  n  corrMpondinf  phyiiologicat  table. 
And  similarly  a  dtsli  ut*  old  p^nn  ha«  a  rery  diHcrent  pnmologioal  funi-tion 
fr»ai  a  pUl«  of  frosli  m«Bt,  even  whan  both  cootaio  the  aame  amount  of 
oltrageii. 

In  thus  romcting  for  dicestion  the  nutritive  value  of  a  <Ii«t  it  latist  also 
he  boriM-  in  mind  that  the  alimentary  caonl,  while  chieHy  a  receptive  organ, 
is  aim  to  aofDQ  extent,  §  '265,  an  oscretory  or;;au  ;  a  free  paaMjte  through  the 
oueI  is  needed  not  anly  for  carry in^c  o!l'  u ndij^rdited  mnlier  but  also  for  get- 
tiiiit  rid  of  excretexl  matter :  and  the  prexeui-e  nf  the  former,  up  to  certain 
limits,  asaista  tli<?  dindiiirKu  of  tbe  latter.  Were  it  pussihle  to  prepare  a  diet 
every  jot  ooi)  title  of  which  oonld  l>e  dijjraiieil  and  ab!iorl>eil,  llie  itie  of  such 
a  (li«t  would  pmbubly  bring  about  diiior<lor  iu  the  economy,  tbroUKb  the 
absence  >•(  a  vuliicieutly  rapid  dischargu  af  tbe  matters  exorctod  into  the 
alimentary  canal.  Hence  cellulose  and  Tike  anlMtaiices,  even  whm  unuitUxed 
thiou^  absonitloa,  are  not  without  tlioir  use,  and  experienoc  shows  thai 
dicastson  may  oc  promoted  by  eating  undigesiiblc  tilings. 

i  95i.  Tbe  several  fbod^tufls  of  a  diitt  may  be  drawn  from  the  aniiuitl  or 
from  the  \*«getabl«  kin^om.  Vc^table  proteiils  appear  to  undergo  tbe 
MOM  clianees  in  the  aliotentarv  canal  as  do  animal  proteid*,  and  the  main 
•Ifecta  on  the  body  of  protdds  Irom  the  two  sourrae  eecm  to  bo  the  sane. 
Oar  knowledge  at  pnMeot,  however,  is  too  imperfect  to  enable  us  to  decide 
whether  tbe  fuDctioois  of  the  two  are  exactly  tli«8ame,  whether  the  bod^ 
beharos  exactly  tlte  aame  upon  a  diet  in  which  the  proteids  are  exclusively 
of  T^fetable  origin,  as  tip-in  a  did  in  which,  otbcrwi*e  tho  same,  tbe  protmda 
an  paitl^  of  animal  origin  also.  Nor  have  we  much  b>iter  knowledge  of 
ibe  relative  nutritive  value  of  vegeuble  and  animal  fats.  And  as  we  nara 
aln-ady  sai'l,  we  poseeas  little  or  no  exact  knowledge  as  to  (he  part  pbiyed  br 
Ibow  extnctiTes  to  reipect  to  tbe  aia[>uat  and  nature  of  which  animni  food 
•triklngly  diSbn  from  resetable  food.  In  attempting,  therefore,  u  Juditmunt 
ftnn  a  pnrelr  physioto^cal  point  of  view  as  to  the  value  of  an  exclusively 
TCKMarian  dfel  compared  witn  a  diet  of  both  animal  and  vegetable  orii;in.  we 
CM  do  little  more  at  prosent  than  imjuire  whether  the  former  nuppli&i  the 
Mvenil  food-stuiEi  in  adeauate  i|uaulity.  in  proper  ptuporlion,  and  in  suab  a 
form  as  to  be  econuratcally  ulilixed  hy  the  body. 


6A6 


NL-TBITION. 


Th«  careful  oxKiainiilioH  during  llirrc  KDArair  pi;nu«ls  I'f  Mvrral  dan 
each  of  ihv  ineMtn  nnH  <^vtn  of  n  tnnn.  'iS  venr*  olil.  wri-i^hing  AT  kilok, 
ivho  line!  for  tnreo  voir'  livr<l  on  hd  oxcIuKtvAlf  vcgelitlile  Oivt,  vii.,  br««4. 
fmil,  nml  uil,  gnvo  t))c  fullowing  mulu  : 

The  (Inily  did  cunsisled  on  ihe  »\trtige  o(  719  grmi.  eolid  uwtlar  aoil 
1084  grms.  water.     It  conlained 


ntitmda 
FntH 

Carbdtiydratcn 
(Ci-Iliilose)     . 


5i  fCTamtnn  ciuilainiiif  S.4  N. 
'2i  ):niiiinit«. 
057  g''i""i"n  (alxKil  }  >ugsr  and  }  ttUrcli). 
16  gramines. 


Tbe  dnily  fccct  n«ighed,  when  fT«sh.  333  gnns.  contnining  75  grtn*.  »>lid 
niniter,  nixl  were  therefore  both  bulkr  nnd  watery.  There  werr  ftrcMnl  In 
the  tvctf,  fnt  7  grnie.,  stnrch  17  grms.,  cellulose  9  grim.,  showing  lIiBt  30 

Iwr  cent,  of  the  tat.  B  per  cent,  of  the  starch,  and  56  per  cent,  of  I  he  cciluliM 
md  not  boen  utilized  by  ihe  body.  The  eubject  hnd  really  livetl  on  fm,  13 
gnaa,,  cnrbohydrntes  ^40  grins,  (and  cclhilose  T  gmiB.).  The fecea oonioimd 
DO  1e«i  Ibnii  3.4C  nitrogen.  If  we  reekon  the  whole  «f  (his  hb  prolcid.  ibu 
would  giro  2'J  ^tiiis.  of  undi^ealed  proteid,  so  that  thei'e  ha*  be«n  ■  u'n»lc  of 
41  per  cenl.  of  the  proleids.  lenviDt.'  only  3'2  gnns.  available  lor  real  u«e  is 
tluibody;  and  indeed  a  very  amnll  (jorlion  only  of  iht!  nitrot;eu  can  be 
rrgnrdnl  as  reallr  discbargetl  fmtrt  the  body  itaelf.  The  loial  stdid*  of  ibe 
few*  nntrt  he  reckoned  a»  portly  excreta  but  cbn?Hy  umliKealod  food.  If  we 
rt'i^rd  tbe  75  anva.  of  »olid  (eca  as  entirely  undi^'atcd  food.  Ibe  nbole  aoUd 
food  available  for  the  body  niuH  be  reduced  from  719  ^rins.  to  6-t  J  crroa. 

The  urine  of  tbe  day  oontniDcd  5.38  gnnti.  nitrogen ;  this  added  to  the  -1.46 
grms.  nitrogcD  iii  tbe  feces  gives  8.79  grnn.  ottrogen  in  tbe  total  egata  as  cmo- 
pared  with  tbe  8,4  grms.  nitmgenof  the  fiwd,  indicating  ••llghtTocs  ofDiiro- 

Sejiuun  material  from  the  body :  but  if  wo  «iip|i(wc  that  all  the  nitrogra  in 
le  feoea  was  not  in  (he  form  of  undignlcd  fnixl  we  may  neglvct  this:  and 
Indeed  the  Nubjnct  of  the  obMrvatioD  woe  in  apparently  ginxl  bcnlth  ami 
stationary  weight. 

Com|iaird  with  either  of  the  iinrnml  diets  given  in  ^  651,  the  aboTO  diet  b 
Striking  for  the  low  amount  of  proteids  and  of  fat*  and  the  relative  escem  of 
airlmh  yd  rates.  But  thon^li  such  a  diet  may  be  fnken  a»  perhnji*  fnirly 
typical  of  the  daily  food  of  a  rigid  vegetarian,  a  much  more  richly  iiroteiil 
diet  may  be  obtained  from  sources  slill  strictly  vegetable.  Thu«  ihi:  diei, 
eotiroly  vegetable  in  nature,  nf  an  average  'lapaneae  lalxirer  of  about  ibc 
BRmc  weight  as  tbe  individiud  whose  data  we  liare  just  given  lias  been  esti- 
mated to  consist  of  proteids  102  grm.*.,  fat  17  grma..  earbonydmiea  &7Jt  frtat. 
Anil  the  dii-t  of  a  H'Umriiiiaii  iK-uiant.  liriug  cbieflv  on  beans  aud  uoiie 
with  the  addition  of  fat  i^if  i>oiiie  kind,  hnn  been  calculated  to  flirnitib  no  lea* 
than  protei4ls  182  grais..  fnt  it3  grnix.,  en  rhohyd  rates  968  gnus. :  btit  the  ml 
nutritivo  value  of  such  u  diet  roust  necil  verv  large  correction  indeed. 
<y.  5  553. 

The  ctaminatinn  of  the  diet  of  an  indivitiual  living  with  n  fair  nttmgviinus 
equilibrium  and  nppareiitly  good  health  on  a  moflitSed  vegetable  diet — that 
la  to  aoy.  oao  whicb  includwfmilk  and  cgg»— gave  tbe  following  r  I'nHetdt^ 
74  grms. ;  fat.  58  grms. ;  carbuhydrat'*,  4yi(  grms. — a  dkt  which  diHere  from 
lliu  normal  diet  almost  solely  in  the  Icwer  amount  of  proteide,  one-third  of 
which,  by  the  by,  was  supplied  by  the  animal  mHterial,  ^gs  and  milk.  In 
another  inslanoe,  nitrogenous  equilibrium  and  fairly  good  health  were 
secured,  for  some  weeks  at  all  ereitla,  oa  a  vegetable  diet  yielding  probrids, 
•bout  100  grms.;  fats.  70  grms,;  curbohyd rates,  400  grms.;   mit  in  tl' 


nMrl^  th«  whole  of  the  Cut  wiu  furuiilied  l>y  the  ntiimnt  pruduci  bailer,  lud 
IJebie'a  extract  wu  (VmIjt  uied. 

Cuniloiitg  ourvelvet,  huwcver,  to  the  more  Mtrictty  vcgelnrian  diet,  vre  rany 
toadod*  in  the  fint  place  that,  imlcM  the  ilnilv  rcHxl  be  very  large  in  amount, 
the  |woteid  elemeot  of  nich  n  dift  fnll>  can»i<Wnihly  boluw  tli«  lOO  or  more 
gnm.  pvcn  in  the  normal  diet.  But  n-e  onniiot  nuthoritativelr  My  that 
Meb  K  radncLion  is  nccMMirily  nn  «ril ;  tor,  n#  wc  stated  nbo^'e  (s  651;,  flur 
knowledge  will  not  nt  prcwnl  permit  iis  to  make  an  autborilnti%'e  exact 
•lalement  M  to  the  extent  to  whicli  the  pri>lH<)  cntir  he  trilneed  without  dls- 
adrantsge  to  the  bwly  when  nccompfliiicil  by  n<)e<|iiaie  provision  if  (be  other 
eleiornt*  i>f  fond  :  nn^  this  slatement  holds  (^>od  whether  the  lio<ly  bo  nitder* 
taking  n  rnittll  or  liirgc  anionnt  of  labnr.  A  eecnrnl  tVfltiire  of  »ueh  n  diet  i* 
the  marked  rv<luetion  of  the  fat  ntirl  its  re jiU cement  hy  ciirb«)hydnitee. 
Although  here  aeain  we  ennnot  make  a  dislinclly  aullioriinlive  stntemeiit, 
Ike  rvidenee  wbien  we  posseea  bears  elenrtv  in  the  direclion  ihnt  stieh  ii 
PtdiK-tino  )»  a  marked  diaadvantafce.  A  thiri^  and  very  charaeceristic  feature 
of  the  Blrictly  vegetarian  diet  ia  the  relalivelv  larRe  aniounl  of  undi]>e«ted 
Ihod  lu«t  to  ilie  body  nud  discharjjed  na  feces,  feven  when  the  diet  is  seamy, 
M  that  the  proietd  element  U  low.  tlie  amount  of  fee»  reliittrcly  to  Ihe  total 
feod  it  high;  and  when  a  more  normal  proteid  contribution  b  secured  by 
smple  HMftblhe  fbce»  liecomeM  exceedin;;ly  voluminous.  Indeed  when,  lenv- 
itt|>  man,  we  compare  the  lierbivonma  with  the  carniroronji  mamma),  we  And 
that  the  former  a  almittt  its  t-learly  dbtiuguivhei)  from  the  hitter  by  its  fre- 
quent and  abundant  feet-*  ■■!■  by  the  nnniomical  fcaturon  of  it^  nrjca nidation. 
We  have  already  nryet)  that.  *inee  the  fceei  *ervea  a*  a  meann  ul  excretion 
of  the  real  voMe  nrmliietN  of  metabolism,  a  certain  amount  of  vehicle  to  earry 
tbew  away  U  of  n<lvantaK«  or  even  neccfmr^-;  but  there  ara  no  fndH  at 
pnaant  known  in  iiit  which  show  that  the  lai^r  in[<«t.itjnl  current  of  the 
partly  vtcelable  diet  etfeetf  any  such  good  ns  csn  eompcneslo  for  the  obrious 
waiM  of  labor  iiieurred  in  its  lmnsp>irl  nnd  mana^menl.  to  My  nothing  of 
the  opportnntties  of  mischief  olfen.-d  by  n  inan  of  material  more  subject  in 
the  dominion  of  forci^m  or^nntf^ms  than  even  to  thai  "f  the  l>udy  iiself, 
ihnugh  these  op|>orl unities  nre  les^  thiin  with  a  correspimding  mass  of  aniimil 
erigiiL  With  rN|iect  to  these  three  feaiuies,  then,  the  Mrictly  vcf^etnrian 
diet  aeems,  on  physiolo;:tcal  j^nxind*.  inferior  lu  one  of  a  mixed  nature. 
There  are,  as  we  said,  other  aspeeis.  «til)  of  a  strictly  physiolnjiieal  kind,  to 
be  considered,  such  as  the  relative  dij^estibilitir  of  vegetable  articles  of  food, 
ibe  relative  metabolic  value  of  the  foo<l-«tufl!t  of  ve|[etable  ori|nn,  am)  the 
inAuence  of  aninuil  extroctivee;  but  any  fuller  dbcunion  of  Uiese  points 
•ould  be  wit  of  pliice  l»re, 

S  566.  We  have  treated  the  diet  discnased  nbnre  as  a  norma)  diet,  suitable 
Ibr  tnan  under  ordinary  or  seneml  cirounistnucet.  Ought  such  a  diet  to 
t>e  modified  for  the  rarioua  exigendea  of  life,  such  as  labor,  age,  climate,  and 
the  like? 

Vt'c  •hall  disctm  (be  influence  of  age  in  the  concluding  portlona  of  ihb 
work. 

Wo  mnv  be  inrlittc),  at  fimt  ^i^'bl,  l»  niMume  that  the  toinl  nmmiiit  of  the 
diet  *li»uh]  xarv  with  tlH>  wi-i^lii,  that  is.  tbe  >'no,  of  tin'  individual:  and. 
indred,  in  discvMions  nn  nutrition,  statonicnts  concerning  nH'lal">tiii>ii  and 
amount  of  food  are  often  given  in  terms  of  |ht  kili>  of  twly  weijchl.  In  a 
broad  Mnse.  it  may  he  tnte  that  n  •ninll  man  needs  Ina  food  tliiin  a  Iarg« 
OM :  but  it  must  be  remeniberrNi  that,  ax  wc  i>nw  in  s|>caking  of  nninial  heat. 
Iho  amaller  or^nism,  having  the  rrhitirely  larger  surface,  cnrri<-s  on  ■  more 
rapid  melaI)oltBm  per  unit  ol  hoity  ucight,  and  so  ntmla  rclalivelv  more  food. 
And,  moreover,  the  influence  of  site  is  prulaibly  far  lest  Ihan  tlie  influenco 


NUTBITIOS. 


6Xert«d  l>f  Ibe  iiiliDni  imlividunl  cliitniolers  i>f  tli«  i>r({nQi«n,  pivinf;  riwln 
what  we  may  call  the  ponoiinl  i>>]iiaiiou  of  tnet«1*o)ii>Ri.  The  saialler  mi^u- 
boliara  ofwoiimn,  Icailinir  t»  lli<-  xik  of  a  wontitT  iliol.  in  n-iinpanHl  with  tbu 
of  n]au,isli>bon-^iiri)i.-'l  ju  l]ii.->  tight  nilhnr  than  with  rvrcn'nce  to  theavenitc 
le^er  wd^ht  of  woniitn.  The  n-hitivc  nn^tiibolium  of  thi-  twn  s«xe(  Diar  be 
illugtraioi)  br  tho  I'luc  i^f  nil  nclivr  nmn  iiiiH  bU  wifi:,  iMhofabmit  the  turn 
nse  aii<l  weight,  tin-  miin  bcinir  rather  the  lu-iivicr  nn>)  thu  woman  rntber  tfai 
"hicr.  who.  in  carryiiiE  oiil  t'ljrrtbpr  an  oxpirimctil  on  iht  rtlutivc  valuM  rf 
vcgviablc  Hill]  niiimiil  foorl.  both  livci)  for  fiiito  little  on  tbv  Mim<-  kiii'l  el 
li'uit,  uut]  found  thut  iiiitriiivo  «>.)iiiUbriuiii  wa£,  in  thi;  on«  caee  aixl  iu  thi 
Other,  Riaintnin«d  when 


Tlic  man  connumed  dailr  about 
Thenrifr        


■"rowtdk 

Pan. 

ntrtm^lMlM 

]W 

70 

WO 

m 

87 

SiU 

Tlic  nicMt  strikiii;;  difference  b  in  the  proteids. 

g  656.  With  re);ard  to  climate,  ibc  chief  cons ide ration'  nttnch  to  ICfapori' 
ture.  When  the  body  h  eicpcKed  to  a  low  tentperalufv:  lhef;cneral  nMa* 
boliam  of  the  bodr  is  iocreaii^d  owin^  to  a  regulative  action  of  the  ncrvotu 
svRteiu  ($  535),  We  might  infer  from  thU  that  more  food  is  necAMarrii 
euM  cliiufttei;  and,  aince  the  increase  in  the  metabalinm  appeari  to  tnanifcM 
il»elf  chiefly  iu  ii  j^ieater  discharge  of  carbouic  acid,  and  therefore  to  be 
especially  a  carbim  metaha1i»in,  we  uiig^ht  infer  that  the  carbon  elemeata  of 
food  abould  be  e»|ieciHlly  increased.  When  tlie  body  ia  ex[K>eied  U>  bi)A 
temperatiirM,  tJieiinnie  retlex  mccbaniam  teud«  to  lower  the  mctabolbni:  bat 
the  effec!t»  in  thin  direction  are  much  Ion  clear  than  thue  of  cold,  aiid  aoon 
reach  their  limits;  the  bodily  tciuperalu re  in  muinlaimv)  coiMtnnl  under  the 
iaflueDce  of  surrounding  warmth  not  mo  much  by  dimini«heil  production  lu 
by  increMod  lom. '  Wc  may  infer  from  this  that  in  warm  climatM  not  Imk 
but  if  anything  rather  more,  foad  than  in  temperate  climates  is  oec«aMry  in 
order  to  supply  the  perapiratiDn  needed  for  the  grvaier  evaponUoa  and  di»- 
obar]ge  of  heat  by  the  skin. 

In  both  cold  and  warm  climates,  however,  man  trusts  mucli  more  la 
rarJBtioDa  in  hit  clothing  and  itamediate  surroundiuK^  to  protect  hiiu  againM 
cold  or  to  Eunrd  b>m  from  heal  than  to  any  marked  variatioiu  iu  his  normal 
<liet.  Ill  Hie  former  he  may  perhaps  be  expected  to  eat  sotDewliai  mure, 
tiinue,  in  xpite  of  WRtppinjiH.  hia  okto  still  feels  iu  part  die  cold,  and  thus  the 
ncrvouA  mcchanttiu  for  ibe  inereote  of  iiietabolbm  »  to  a  certain  i^xtenl  mi 
to  work.  And  xinre  the  inelabolbim  thut)  inoreAitei]  apjieani  to  atTect  cape- 
cinllr  the  ntrlion  of  the  hoilv,  he  mnv  further  be  expected  to  incrca«i:  Ui« 
fat*  rather  than  the  rarhdhvilmtni  of  bin  food,  neeiag  that  the  fiirnii>r  KUfiply 
him  with  the  inoyt  energy  for  thur  wd^^ht.  But  it  is  very  doubtful  whetner 
what  he  might  ihii*  hi;  cxpcctv<l  to  ^in  over  a  corn«|Hinding  incrmM  in 
carbohydmtiv  in  not  more  than  coiinierlialanccd  l>v  the  iiicreaMxl  latior  of 
di;r<v|ion  ;  and  ihi-  habits  of  the  dwelleni  in  arctic  cliraaCcM  cannot  safely  be 
taken  ns  giitdcH  in  ihi»  matter,  for  their  reputed  love  of  fiit  is  pn>baMv  the 
roiilt  of  that  heinif  their  most  available  form  of  i-Jirbun.  Indetvl.  the  evideaoe 
that  the  iticrean-  of  rnelAholism  provoked  by  cold  bmrs  excUiitively  od  carboo 
ooostltuents  is  so  uncertain  that  it  may  Ih'  doubted  whether  any  change  ID 
the  normal  diet,  bevond  some  increase  in  the  whole,  should  be  made  to  meet 
n  colli  climate.  Similar  reasooa  would  load  one  to  infer  that  man  in  tbe 
warmer  climate  would  maiulain,  on  tbe  whole,  tlie  same  normal  diet,  the 
only  cbange  being  perhitiu  to  increoje  it  Eli|;;htly,  puasibly  thmwini;  ibe 
inerea-te  chleOy  on  ibe  carbvhydrales  with  llio  special  view  of  ftirlliering 
|icni|>iratian. 


I 


on    DIET. 


I U7.  A  fpccwl  diet  for  tlie  purpoK  nf  (ati«Din^ — that  b  to  Mtv,  for  ' 
■ctnnalnttoD  uf  sdi)Kii«  tiutie  out  of  prfifKiriioii  to  ilie  mt  of  ili«  t>nily — it 
Mt  MVtIvd  in  llie  tnfv  of  man.  The  \m*i!t  tu  >t<>n.'  ii|i  fat  in  HtliiMNM;  iLuuc 
b  micb  more  dc|>rmlcnt  »it  ci-rlttiti  iuhoru  i|t)aliiim  of  the  umnwu)  uliich 
w*  cunot  at  [irvMDt  iHioc  itiun  mi  llii^  kind  of  food ;  of  two  Wlin  living 
Ml  lh«  aanii!  dii-t,  and  under  th*t  simtv  cirouinvtarnxv,  oiiu  will  bcfonx-  Int 
■  hilv  the  olh«r  will  remain  Iciin  ;  and  il  i»  tin  object  of  llic  amoilluriKt  10 
ikr«]o|i  by  lirwding  nnd  »rli-cCion  a  "coiirtiliiliiin"  which  wtH  rtorc  up  ibo 
neat  (at  on  th«  clM.-iip<«t  diiM.  in  ftltrniog  anitnalo  tb«  cJiirf  can-,  when  the 
Mlrction  of  iIm'  kin<l  uf  nnimnl  hn»  Im-n  oinde,  i«  to  provide  ndt'iiinie  cnrbo- 
hrdmte  food,  which. »  w«  have  h-cd,  is  tlic  chief  tatlrner;  and  Uic  object  of 
thv  liarRivr  in  rrnrin^  stock  for  iho  biilcfacr  te  nminly  to  convert  cheap  vege* 
labia  cnrbohydrntc  into  dcnr  animal  fnt  Pimbcr  aids  in  fntlcoing  rony  m) 
found  in  providing  rcpum  for  the  body  of  snch  u  kind  that,  whil«  sufficient 
nergy  is  expended)  to  secure  ade'juatc  digestion  and  nbsorplion  of  food,  all 
caures  leading  to  an  increase  of  melabolistn.  by  which  energy  is  set  free  and 
Itaves  the  body,  are  avoided  aa  much  a>  possible. 

Tu  avoid  fai  miber  than  to  inoreaM  it  ia  often  ui  objed  of  human  can. 
This  may  be  eticL-led  by  diminishing  fats  and  carbobyd rates,  but  also,  in  a 
very  nwrkfd  manner,  by  relatively  inereaBing  the  proteida.  I'roteid  food,  u 
«C  MVe  wen,  augmeiit«  ibe  whole  metabolism  of  the  body,  hurrying  <m  the 
dMtniction  not  only  of  proteid  but  of  carbon  food;  and  a  tendency  to  cor- 
pulency mair  be  couatenicte<l  by  a  diet  in  which  fata  and  car bohy<l rates  are 
much  renncted,  and  proieidu  erv  largely  iDcreaaed.  When,  aa  in  what  is 
known  as  the  Jianling  niethoil,  the  uiel  is  almost  exclusively  proteid,  the 
nitrogetiuus  nverwork  entails  dangera  on  organinnis  which  do  not  possess  the 
power  of  ridding  ihemaelres  freely  of  the  large  amoiiui  of  nitrogenous  waste 
which  such  a  diet  produe>r*.  A  lea*  Mvere  methoil  in  which  the  &ta  aod 
cartmhydmtn  are  diminished  only,  not  CBtirely  done  away  with,  and  lite 

Srottida  only  moderately  increnspd.  is  lew  open  to  objection:  and  such  a 
ict,  BMotcd  by  other  hygienic  conditions,  has  proved  successful. 
Ad  increase  of  daily  lood,  largely  proteid  in  nature,  given  un<Ier  circtim- 
MaDCa.  such  as  a  large  amount  of  iwssive  exercise  and  skin  stimulation, 
known  as  "  maaeago,"  which  will  not  only  favor  digestion  but  also  promot* 
■nUbolitin  in  general,  may  be  given  with  favorable  results.  In  this  wayan 
caorBWas  metabolism  may  be  excited,  and  yet  so  carried  on  thot  the  body 
B^m  both  in  tiesh  and  in  fht.  Thus,  in  one  case,  the  patient  with  an 
mhial  weiKbt  of  46  kilos,  and  a  daily  nitrogenous  metabolism  calculateil 
■a  28  pms.  proteid,  reachtKl  in  the  course  ot  about  fifty  days  a  weight  of 
60  kiloa,  the  dailjr  nitrogenous  melabolbm  being  raised  on  one  oocaston  to 
182  ^ms.  proteid,  witli  an  average  on  the  whole  |>eriod  of  150  gnuB. 
Doring  the  treatment  no  less  titan  8420  gnus,  of  proteid  were  taken  as  food, 
g  6w.  With  regard  to  labor,  since  as  we  have  seeit  tlie  energ\'  expended 
as  work  doite  is  not  taken  unt  of  and  away  from  the  amount  set  tree  as  heat, 
the  two  forms  of  energy  being  so  related  that  an  increase  of  work  dona  is 
aoooinpanicid  by  a  greater  orlcHii  increase  of  heat  set  free,  it  is  obvious  that 
a  nan  who  is  doing  a  bard  dav'n  muscular  work  needii  a  larger  income  of 
aurgj  for  the  day  itian  dors  nn  idlii  nuut.  What  ne  have  learnt  concerning 
muscular  mvtabo1t«n  further  >hows  um  that  the  additional  energy  needed  ia 
not  necessarily  to  be  tiipplirtl  bv  nn  incirnK-  in  the  prnii-id  com|>oncnU  of 
the  diet:  tl>e  energy  of  musi'uinr  contraction  doon  not  pome  an  was  once 
thought  from  proteid  metabolism  |^§  MO).  The  fact  ibnt  it  is  the  carbon 
tDeiam>li*m  which  ia  augmtated  in  muacular  work  may  suggc^  tltal  the 
BXlra  (bod  for  extra  work  should  bo  exclusively  carbon  oomfwumts :  and  if, 
aa  SteODS  pn»bable,  the  carbohydrates  are  more  readily  and  dircrlly  avaiJablo 


670 


NCTRITION, 


fertlieAinctionBl  meLabolItmof  luuicle  than  are  (tie  fntA,  we  laigbi  beAutW 
led  In  reoofBinend  an  iucruwe  !ii  oarbolivdniua  to  funn  a  di«(  e9|>«ciallr  niivj 
for  labor.    But  wrernl  cni»i(l«ntioi»«litiul(I  iiiakeuH  liexitaie  before  w« con 
to  silcli  u  coDclu«ion.    A  miitclc  ii  nut  u  luiiahinu  wiiliUi  llie  \iodv  vliicli  oa 
be  lowloci  aud  Bred  wlf  irriMpcctire  of  tbe  nvi  nf  the  budy.     In  tJie  jwriunu 
ance  of  muscular  labor,  tbo  ooiiditioD  of  the  miiK-lo,  the  amount  of  cotr^v 
available  !□  the  muacle  itMlf,  i«  of  eourw  of  pritoK  impiirtaiiee:  hui,ijii! 
tbis  perbajK  etpociallr  hold*  good  iii  wevorc  labor,  of  ^mit  imiionaiiM  tin, 
we  might  aldo  «ay  of  no  1«>«  itii|ii>rtuiKf,  b  na  w«  have  tir^ed  Ci  391  iln 
|K<wer  of  llio  body  ii«  a  whoU-  to  iiTuil  iuulf  of  tbe  energy  lau-nt  in  lh\i  iuu»' 
cl<d,     The  power  of  doing  work  bangK  not  <Mi  the  niUKle  sIodo.  bill  on  iht 
heart,  the  lutigs,  the  nervouH  system,  und.  indeed,  on  the  irholv  IkkIv-    It  u 
very  doubtful  whether  wo  c^*cr,  even  in  supreme  etlbrt«,  draw  upan  luier 
Uian  a  portion  of  the  capital  of  energy  lodged  in  the  muscle  ilsvlf:  fitli^ 
b  for  more  a  oervoue  than  a  inusculnr  cuodition,  and  even  tlie  diuiudlt 
muBCular  fatigue  is  as  we  have  seen  (j  H^J  partly  at  least  the  resitlt  tf  thir 
accumulation  of  products  and  noi  alone  the  using  up  of  available  <Mr|;<. 
In  choosing  a  diet  Jbr  muscular  labor  we  must  have  in  view  not  theniiint 
itrelf  but  the  whole  organism.    And  though  it  is  possible  that  future  rswan^ 
maysuueeets  lUinor  obangea  in  the  various  oouiponenia  of  a  normal  ifiel  neb 
tu  woufif  leaseD  the  siraiu  duriii;;  labor  on  this  or  that  ]karl  of  tbe  body.w 
the  inuiclea  aa  well  ns  on  other  organs,  our  present  knowledge  would  ratkn 
lead  US  to  eondude  that  what  a  good  for  tbe  orsanism  in  comparative  im 
b  good  also  for  the  orf^bm  in  arduous  work,  ihnt  the  diet.  Dorroal  tat  tk 
former  condition,  would  need  lor  the  hitter  a  liuiit«Hl  total  increoje  but  g» 
•Iriking  change  in  ita  conipuailion.     lu  iireuiiriait  the  body  tbr  aome  cuain; 
arduous  labor  in  '*  Lraining"  as  it  ii  eulletl.  an  inureaie  of  protod  food,  (ot 
th<i  purpoMe  of  liurryintt  on  the  ^uural  nietuboli-tui  of  the  body,  and  tluu 
of  making  "  new  lle«h  '  and  renovating  the  bo<ly.  «o  to  speak,  to  vm«  o( 
the  strain  lo  be   put  upon,  may  jwrhape  suggtat  itself;  but  even  ikuW 
doubtful. 

The  priaci]>l<«  of  sucli  a  conclofion  with  rt^nl  to  muccular  work  aai 
be  applieil  with  still  gnuilcr  conlidenoe  to  nervous  or  menial  work.  TW 
actual  cx[>enditure  of  energy  in  nervous  work  is  relatively  small,  bat  tk* 
indirect  influence  on  tbe  ecunonty  is  very  great.  The  cloMUew  and  iiiin 
cacies  of  the  tics  which  bind  all  parts  of  the  bmly  together  is  very  clenrti 
shown  by  the  well  known  leadenciee  of  so-called  brain  work  to  derange  ibt 
digestive  and  metabolic  aciivitiea  of  the  b<]dy ;  and  if  there  be  any  did 
ee[)eciallv  suited  for  inldlectual  labor  it  is  one  directed  not  in  oi 
toward  the  brain,  but  euiii-ely  toward  li^dileuing  the  labors  of  and  ainq 
the  way  for  such  juins  of  tbe  body  as  Uie  siomacb  aud  liie  liver. 


BOOK   III. 

THK  CDiTRAL  UERVOUS  SYSTEM  AND  fK  IXbTKL-MBKl^. 


CHAPTER   I. 


THE  SPINAL  OOBD, 


Ov  SoMK  FiuTirRKB  OP  TUB  8ri!iAi,  Xkrveb. 


I  558.  Wk  liav«  csllml  tbe  rnusculamnd  nervous  limuee  lh«  maclcr  Iimum 
vf  (be  iHiily :  hut  n  epccinl  part  of  the  nervous  systcin,  thiit  which  wc  kDOtr 
M  the  i.'cfltnO  ttervouB  bvbUiiii,  the  bmin  mii)  spinal  cord,  is  supreme  aiuonj; 
llie  uerroiis  tissues  nn<)  is  iniuier  of  the  skeletal  iniiscles  as  well  as  of  the 
len  itf  the  bo<ly.  We  Inive  already  (Book  I.,  Cluipler  HE.)  touched  on 
•on>e  of  the  (general  leaturei  of  the  Dervous  syslcm,  aud  have  now  to  study 
ill  d«inil  Um  votk'mg  of  the  braiu  and  epinul  conl.  We  have  to  inquire 
iihci  we  know  coui-eniinK  the  taws  whicb  reculate  tbe  diacbsfg«  of  eiferent 
inpubeB  froDi  tbe  braiu  nr  fruni  ibe  cord,  ami  to  learu  how  that  dtKbarge  is 
iMtrotiued  on  tbe  uue  hand  by  intrliiiiic  chanKt'i  uri^inntiug,  apparently,  in 
the  Mibstaoce  of  the  brain  or  of  tbe  conl,  and  on  (he  other  hand  br  the 
naturf  and  aniouui  of  tl>e  aiferaiil  iiupulttce  ubich  reach  theui  along  aOereot 
attvt». 

Aa  we  shall  *ee  the  ttu^y  of  the  spinal  cord  cannot  be  wholly  aqwriiied 
from  lliat  of  tbe  brain,  (he  two  being  very  cliM^ly  rcla(«il.  NvvoftbeleiM,  it 
will  be  of  advnnioge  to  deal  with  (he  spinal  curd  by  itwlf  a*  fur  a*  w«  am. 
TV  medulla  uhlotinu  or  spinal  bulb'  we  *luill  cun.iider  an  pan  of  tbe  breb. 
Bui  belure  wo  speu  of  (he  mmiibI  cord  itself,  it  will  be  dcnrablo  to  snr  a  few 
wonb  GOBcerning  lh«  spinal  neri-n,  that  is  to  say.  Ihe  nerves  wbicn  issue 
fVom  (ho  spinal  cord. 

We  have  alrcsdy  soeo  (S  96)  thai  each  of  the  spinal  nctree  arises  by  two 
roou.  an  anterior  root  aUached  to  the  ventral  or  anterior  aurfac«.  and  a  pos- 
terior rxio*  atta^^'hcd  to  (be  dorul  or  piwteriorjturlaei)  of  the  oord.  Wu  have 
further  seen  ibnl  ihc  latter  bears  a  ganglion,  a  "  ganglion  of  tbe  posterior 
r<>ot "  of  **  spinal  ganglion,"  and  we  have  (%  97)  studied  the  structure  of  this 
Ipiiialian. 

We  stated  at  tbe  same  lime  (hat  while  tbe  trunk  of  a  spinal  nerve  con- 
iaiu«(l  both  efieivnl  and  aflV'renl  fibres,  the  etlVrent  fibres  were  ^ihered  up 
inhi  tbe  anterior  rout  and  ihe  aRerent  fibn-s  inoi  tlie  jtoeleiiur  r^ii>t ;  hut  we 
gnvt  no  pnwf  of  this  aiaiemenl. 

j  000.  Before  we  proceed  to  do  so,  it  will  be  as  well  to  aay  a  few  words  ou 

•  llwlunntdalkoMoMkiaUeaicailr  lui)a.Ii<iiprtiwnwdUBt«ltli^ilnMtlu  want  mMhilla  l 
l>Dn*  iwWaaidloaMnMiw  wlial*ii'lna^nirdt»«dall>a(4iwlto)IMIIifMi«r«l>r  iiMdIadmnMrl 
■iMwcKllsrcaatAtaiMmabn.tlMirbliafatMsnMnr  SelmuB.    in  ariit  iMtaul  tlw  •ih4  ti*  I 
iiTtrair^iWTir.MflwINilSUiwclilHilefctrottonfimonwIih— ypQwtMndirf Iwlti.  'neo^koUre 
b  la  wa  Bueiinkoa  usi^  lu  uxb  plifwa*  ■■  "  bultar  |«>*ll**-' 


«72 


THE   SPIN'AL   CORD. 


tli«  Icnuit  "efTereut"  mid  "  nlTeivnt."  By  d&rctit  iicm-u  Rbras  wv  mtn 
DftTVe  lilirea  which  in  llie  1>ody  iiftuall}'  nirry  impubrt  rn>in  [lt«  cvoinil  im 
TOUS  lystcni  tu  perijihernl  (irj^im.  MomI  elkrciil  iifrvc  fibnw  cHrr\'  impulai 
to  miMcleti,  Ktriateil  or  pliiiu.  und  the  inipulwcii  jnLwin^  nloof;  tliem  givr  riit 
to  moreDienU;  Iicdcl-  tnoy  are  frequcntlr  t>pokr-D  of  ni>  "  moUir  "  fibre*.  Rg) 
all  eBlbmit  fiUnv  do  not  end  in  or  c«m' iiii[iul«cti  lo  niiii>ciil»r  Rhr>^;  wr  hiit 
•een  for  imtlHiicc  thtkt  pudp  cfliirfiit  fifirw  urc  ^ccwlory.  Slorewvpr.  all  tit 
nervfi  fibm  goin^  to  mii^ciilnr  fibrt-n  do  n»t  mtrvc  to  produce  lumciDCdl; 
>oiii<i  of  th«ni,  ns  ID  tho  c«m  of  ccrtnin  vnguv  RUm  going  to  iIm-  hvAtl,  ir 
inbibitorv  sod  mny  wrvv  lo  flop  movcmrDi. 

By  ■■  nflbrvni  "  nerve  tibrc"  wc  nienn  norvc  fibre*  which  in  ibc  Iwily  itHiillT 
cnm'  impuIsM  from  ixriphnrnl  orgHii»  U>  the  cetilral  nervous  ivsteni.  k 
very  coniiiKin  eA'pct  of  the  nrrivnl  nl  the  (.'cnlnil  nervous  lytteni  »f  impulNi 
pnsNnf;  along  atlcrent  fibres  it  that  cliniij^  io  consciousneas  which  we  csU  • 
■' «n8»tion '■ ;  heoce  atlerent  fil>rra  or  iuipuUes  are  often  C*U«d  "  seDnrjr " 
fibm  or  impulses  But  m  we  have  already  in  part  seen,  aod  ■»  ire  uall 
aboitly  see  in  greater  detail,  the  central  uervoua  system  may  be  airecied  by 
afferent  impulf^s,  and  that  in  several  ways,  quite  apart  frum  the  developrncat 
of  any  ftuch  change  of  consciousness  as  may  be  fairly  called  a  aciuiatMB. 
We  shall  see  reason  for  thinking  that  oll^rent  impubeii  reaching  the  tpuial 
cord,  and,  indeed,  other  pans  of  the  central  Denroui  svMem,  may  modify 
reflfix  or  automatic  or  other  activity  without  neoewarily  giving  rue  to  a 
"aeiuation."  HeD<;c  it  ia  advisable  to  reserve  Die  terinft  "cfl«t«i)t"  and 
"  afltreui  "  pa  more  genenil  inodea  uf  cxprevion  tlian  "  motor  "  nr  "Mi»ory." 

We  Lave  «eeii  iu  trciiting  of  niuscie  and  iier\'e,  that  th«  cluingis  prxluccd 
in  the  muscle  aervc  an  iiur  butt  guide  for  d«t«finining  the  chan^fc*  taking 
plave  it)  a  motor  uervi^ ;  whrii  n  motor  nerve  is  separated  frum  ii»  mufde 
(§  72)  the  onir  chungi.^  nhich  we  cuii  appn-ciatc  in  it  w  on  ckctrioil  change. 
Similarly  in  the  cose  of  nn  afleriMit  nerve,  the  central  fVBtem  is  our  chief 
teacher ;  in  a  bundle  of  alTeretit  librf«  iwlntcd  from  the  central  nervous  stv 
tcm,  in  a  posterior  root  of  a  iipinal  nerve  for  iuflaneo,  the  only  change  wh  * 
we  can  spprccinte  is  an  electrical  change.  To  learn  the  charadera  of  af 
ent  impulses  we  must  employ  the  central  nervous  system.  Uui  in  this 
meet  with  dilTlcuttieg.  ]n  studvitig  the  phenomena  of  motor  nerves  we  art 
greatly  awiated  by  two  facts,  tirst,  the  muscular  contraction  by  which  wt 
judge  of  what  is  going  on  in  the  nerre  is  a  comparatively  simple  thing,  un* 
contraction  ditlering  from  another  only  by  such  features  as  extent  or  amoont, 
duratiiiu,  frequency  of  repetition  and  the  like,  and  all  such  diflbr«ncM  arv 
capable  of  exact  measurement.  Secondly,  when  we  apply  a  stimulus  diroctir 
tu  ilie  nerve  ilnelf,  the  Gtlecia  differ  in  degree  onlv  frum  thoM'  which  tfmU 
when  the  nerve  u  *et  in  action  by  nalural  stimuli,  such  as  the  will.  When 
wt  come,  on  the  other  band,  to  inveetiKaie  the  uhenomeua  of  ofl^nt  nerrn, 
our  labom  iire  for  the  time  rendered  heavier,  out  iu  the  end  more  fruitful, 
by  tbe  following  circutnilancet :  Pint,  when  we  judge  of  what  ingoing  on  in 
an  affcrrnt  nerve  hy  the  etTeris  which  stimulation  of  the  nerve  priHhicca  in 
•onie  central  nervuu.i  organ,  in  (he  way  of  exciting  or  mollifying  reflex 
action,  or  modifying'  nuiomatic  action,  or  affi>ctlDZ  conMaoutnoH,  we  an 
met  OD  the  very  lhm>hhol(l  of  every  inquiry  bv  tb«  difficulty  of  clearly  dia^ 
tinguiahing  tho  cvciita  whicJi  belong  exclusively  to  the  aAerait  ner^e  fmm 
thoM  wbiui  belong  li>  the  central  organ.  Secondly,  the  eflecta  of  aiiptying 
a  stimulua  tu  the  neriphcrtd  ciid-or^n  of  an  aflcrcnt  nerve  are  ver)- dilTerent 
from  lliiife  of  nmOyiiig  the  Ninie  «timiilu«  directly  lo  (he  nerve-trunk.  This 
may  he  shown  by  the  simple  experience  of  comparing  the  senration  caused 
by  oringing  any  sharp  body  into  conlHct  with  a  nerve  laid  bare  in  a  wound 
with  ilial  caufed  by  conlnct  of  an  Intact  skin  with  the  same  body.    Tbew 


(liOtrencea  rvval  to  lu  u  ci)ru|>l«iitx  of  impulaeB,  of  whicb  th« 
a«  of  motor  nervee  «ve  m  liitnlly  u  hint. 

loll  further  ee*  iu  dutail  later  un  itist  our  conaciouNica  mav  be 
•flnietl  ill  uisur  (liflcrfiu  wnj-«  by  alti-vfiii  iiu[iuUeei  we  inuM  (iMtinevbli 
aaly  wiuory  from  other  uflvrvDl  iinpiiliieit,  but  aJiiu  dilfereut  Ictiid*  i>f 
ry  impulm  from  eui-lt  utlier.  C'erutiii  «lliif«iit  uerveti  ure  itjiiiketi  of  lu 
oitfeaal  wnae,  kikI  ilie  nature  of  the  affereut  impuluea  pftuing  aloae 
•peeial  nerirea,  logMber  with  the  mwlifimliuiia  of  couaciouiaeu  vuuwd 
br*rrivmlortbeae  irii)iulM-Bi>i  ihei.i.-iilnil  nervous  ■yat«ia,0ODiUlut«  by  tlMBf 
•elrai  ocMnplez  un)  ilitliaili  bnuich  <>l''tu<lr.  In  •unu)  of  the  problenu  oon- 
ncctnl  with  ilio  cnitral  ivi-n-ou*  untviu  w«  tnitU  hnw  to  itp[K«l  to  the  rwulta 
ufadmlvot'  lli«»vK|ic<.'iiil  •eiiMv;  but,  <>»  lli«ot)ier  hauil.a  kniiwIiHlge  of  the 
ftntrnl  iwrvou*  kyrtciu  U  uvctwsirv  to  n  pro[HT  undentt«n4liti|j  of  tlie  mmk'ui\ 
MHta:  and  du  iba  iibolw  it  will  be  niurc  convcniciit  to  Mludy  tlut  fonuur 
btbra  Ibf  laitrr. 

We  may,  biiwcvor.  digrtn  here  to  rornnrk  thnt  the  'jumtioa  whether  an 
ftUvrvut  iutpulsotliUcra  in  iteclf  from  au  vlfvretit  itupiilse  a  uiiv  uf  grcitt  tliHi- 
eullf.  It  w  tniv  tliut  lh«  clcctricul  clinngw.  whicb  alunc,  lu  w«  have  sai<l, 
waQaaap)irc4'tHlv  iu  aii  iMlate<l  piece  of  nerve,  appear  lobe  thoaamo  in  both 
Uoda  ol' fibraa ;  to  eacA  the  electrieul  chan|^^  it  pn>piigaled  id  both  tjiree- 
liaaa,  aod  pciewM  the  same  fnture».  Btit  it  would  be  hazardous  to  iuaiM 
IM  niuob  un  Uih.  Moreover,  we  niu«(  reiiieniixT  that  wbal  we  call  a  nervou* 
inpabe,  eapecialty  ooe  provoked  by  artilicial  uiniulacioo,  cunstitutcfl  a  tira»i 
ehange  in  the  nerve  fibre,  uod  timt  obaogce  of  a  fioer,  more  deliuace  nature'. 
MOb  ar  cannot  be  oliowu  b^  the  eunrse  methods  lued  to  ileteet  u  "  uervoiis 
ia^Be,"  way  lake  placv  iti.  tiuil  be  pro|Migaietl  alon^,  a  uerve  libre.  We 
"  have  occasiou  iuiiii«tliutely  to  puiui  nut  that  the  cMudilitui  of  au  altt'reiil 
8bre  along  ita  wbiile  length  is <lej>efideui  on  a  nerve  celliii  tlie  }i;uu^lii>D 

the  poetemr  nxit ;  lb«  tibre  wheti  cut  otrfraui  the  oerve-ctll  tU:|;eu«nilM 
and  dica.  TbU  mttau  llial  in  tlw  intact  libre  certain  inBiieucei  are  prupa- 
ntctl  aloDK  tlM-  fibrtfrom  ibe  ecll  in  the  ganglion  to  tlic  jwriphttml  cothngv  of 
mftbre^tkat  i»  toaay  inadircciiiMi  th«opMNit«of  that  taken  by  the  ordinary 
iwrvaua  ioipulica :  and  it  mnr  br  tliai  in  like  manner  in  oflerent  fibrw  tome 
ioiluetlMB  ore  propagated  c«ntripotally  from  the  p^'riphcrul  endings  to  the 
etntnl  oervous  syatem.  Uur  knowleilge  of  ibew  iuHucnoca  is  extremely 
UntUid;  but  it  is  important  to  bear  in  niiiiil  the  powibility  of  their  ocour- 
nooe.  And  we  bad  tbta  in  view,  when  above,  in  speaking  of  ederenl  awl 
albrent  fibre*,  we  use  tlie  pbraae  "  usually  carr^'  impulses." 

$M1.  Thepruof  that  the  alTelvntaudetrerenLfibrvswhich  are  bocb  present 
in  the  trunk  of  u  -j<iual  nerve  are  parted  at  tbe  routs,  the  elFerent  fibm 
rtutainK  exclusively  in  ihe  ventral  or  anterior  root,  and  the  atlereut  libre* 
exdunvely  iu  tbe  dumal  <>r  ptoilerior  rciot.  is  as  follows  : 

Wb«n  the  anterior  ruui  it  divided  the  rauaolee  supplied  by  tbe  nerve  ctue 
lubi-  tbrunu  into  ci)ninii:ii<.in9,  either  by  the  will  or  by  reMex  action,  while  tbe 
rirtictures  to  which  the  uerve  is  dintributol  retain  itieir  woaibility.  Daring 
iIm  section  of  ihc  root.  i>r  whtrn  tbe  proximal  stump  that counected  with  tlw 
»pianl  cord  in  stimulated,  no  feuory  etiects  art>  pruducwd.  When  tbe  disttil 
■tump  is  stimulated  the  musrle»  supplivi]  by  tbe  »vrv«  are  thrown  into  ooif 
tractiotui.  When  the  (HMierior  rout  i*div-t<led  the  miutdea  supptiuil  by  tbe 
uarvacantiniie  to  be  thrown  into  action  by  an  vxercisvuf  (be  will,  or  as  part  of 
n  nflex  action,  but  the  rtrucium  to  which  the  nerve  is  distribut^xl  low  the 
■ettsibilily  which  they  pivviousJy  poMtwod.  During  thv  svclivn  of  tbe  root, 
ttnd  when  the  approniuiiil  Munin  is  stimulated,  tbe  senaury  eflecis  ore  pro. 
dooed.     When  the  distal  stump  is  stimulaieil  numovemenu  are  called  forth 

» 


lapai 


TBI   SPIN'AL   OORD. 


Tlii-M- rni-M  liurnoMHt rail!  Oist  »eu»>'rr  tinj>u)»n  |>iim  I'xcltiHveIr  Itr  tlw  jx 
rior  m<>l  fmm  thn  ]x:rtiilii-ral  !»  iIm'  r«iitrnl  i>rxiin»,  nii'l  itint  molnr  iin|iuk 
|M«  vxcJHxivttly  by   In^  niili-rior  tiM  fruni   Ine   wntrnl   to  tlir  prrifik* 
nrgaiis;  ttntl  lufttr  an  mir  kuDwhtdgi-  ^lut  thcMiiit;  linldii  gund  uo(l 
wiwon' Mil)  motor  but  nlsit  fiirnOirrDi  nii<l«-flrn'iil  iminilMA. 

An  exvcfrtion  niuot  bi'  inad^  to  thv  iiIkiv«  f^itcnil  nUKrmi'nt.nii  tuvaaMtt 
the  Ro-cnllrd  "  recurrent  M-iisibility  "  which  n  v.itntittvd  \n  oi>iiertiiu«  ouui- 
inals,  uaAcT  ivrUin  ciministiincM.  It  imn>otiiii«»  hnp|i«n)f  tbitl  wbi-D  1)m 
(lialsl  stump  '^f  lh«  diiHdcvl  anlenor  ront  to  diniulntol,  mbiii'  o(  ]tnin  an  oil- 
llflfd  Tb«i?  aiv  Dot  caiis^  by  the  conciiTrenl  inUBciitiir  oiitrnclMitu  <>r 
enuilp  which  the  ^tiniulnliou  ocranioos,  for  they  pcnist  nl1«r  the  wIkiIc  tniak 
of  tlie  nerve  faaii  been  divided  anine  little  way  below  the  union  of  tlie  nvtt 
above  tlie  uri)(inB  of  th«  muwular  branrh«e,  m>  thiil  no  comnirti<>n*  Ink* 

|>l«oe.     They  disappear  when  the  )xiJteri<>r  root  is  Bubseqitenily  r( t 

lh«y  are  not  seen  il'  Ihe  inixeil  nerve-trunk  be  di\"ided  cluee  to  il  f 

the  toots.     The  phenofuetia  are  probably  due  tn  tlie  I'aet,  tluit   ixindla  nf 
•AOfwry  fibre*  of  the  jMxiteriAr  root  atter  runuiDX  a  ahort  •li^iarx'V  ilimn  ik' 
niisn)  tniuk,  Uini  bn<-k  and  run  upiranl  in  the  anlertor  n>ot  (Ix-ini!  <' -  i 
utcd  ]>ntl>nbly  i»  the  pia  iuni«r)  and  by  this  recurrent  eoura^  give  lu-.  i 
iIk'  renirrcnt  aeniiibititv. 

$  W2.  CWcfniiu);  tfif  i^iir^/infion  Uie  poUeriorro()t,we  lnn)'•ll]■d(flldt«lr 
tIlat  vr«  have  no  vvi<Vn<«  that  il  can  act  Ma  evntiv  of  r«Aox  action  nor  h«vr 
w«  any  evidence  tJiai  il  cbu  s|H>iitanv>u)ily  (riv*  origin  to  rKerent  \n^~<-'  ~ 
und  tliuenct  lu  a»  nulomatio  centre,  a*  can  the  ceiilral  nervous  ^ysteii: 
The  bodies  of  tlwiwrvcocUe  behave  iturwvf  bat  dilTorontlyfrvim  ihe  axis-"*  lin- 
ders  at  Minte  d)«t«ii<-c  from  the  cllx.  thntif^h,  ii»  wc  have  aMu.  these  ar«  in 
reality  procMaea  of  the  Dcr\'cc«IU:    ihu«  the  n«rve-cctl8  in    tl>e   inuiglino 
appear  to  be  more  #enattive  to  certain  poi«>ns  than  are  the  nerve  flbree  of 
th«  nen-e-trunk.     But  bevond  I  his.  our  knowledge  otnt^minf;  the  ftiiMlino 
of  the  gaiiKlton  is  aln)u*t  limited  to  the  fact  that  it  i»  in  flome  way  intiaialfiT 
conaeeted  «ilh  the  ntilrilion  of  the  nerre.     Aa  we  have  already '(§  8S)  enui 
when  *  mixed  nerve-trunk  is  divided    the  peripheral  portion  uegenenttf 
fVom  llie  poinl  of  seclinn  downward  toward  the  peiiplwrr.    The  eenlml  |"'f- 
tion  docs  not  m  desenerale,  and  if  the  lcnxtl>  of  nerve  renmviil  In*  not  <>•' 
great,  the  tvnml  jiortion  may  Rrow  downward  bIoiik  the  eounie  »f  ilnt  df^a- 
eraling  peripheral  |x>rlioii,  and  thus  iv^nerale  the  nerve.     Thi#  div>'<>*n- 
eraiion  t*  olu^rvcd  when  the  mixed  mink  h  dividol  in  anv  (xart  »f  il4  niunr 
fn>in  Ihv  iK-riphery  to  clnae  up  t<i  t)i«  ganglion.     When  iIm;  niBitcri»r  roM  it 
divided  iMtwcen  the  ganglion  and  llie  «pinnl  vonl,  the  ptirtmn  atlacheJ  i" 
thiMtpinal  cord  degeiMralea,  hut  that  alutcltud  b>  the  ganglion  remnin*  'n-:!"- 
When  the  interior  root  is  divide*!,  the  pruxiinal  portion  in  connei.-tio]! 
th«  xpinal  cord  remaimi  intact,  but  the  distal  portion  lirtwcwn  the  ^ni  mi  nnl 
the  junction  with  th<-  other  root  dtg«D*mtM:  and  in  tho  inixeil  n<'iv>'  iru'l 
many  deeeiMraied  (ibm  arc  »ceii.  whidi,  !f  they  bo  cnrefully  traoed  i«ii,  irr 
fonnd  tolw  motor  (e(R>ront>librci>.    If  the  piiaterior  nxit  !>«  divided  nnfal'.' 
botweni  the  ganf^lion  and  ihi)  junction  M-iih  the  anlerior  roi>t,  the  oaall  PO" 
lEoti  of  the  poilonor  root  left  alUcbe<l  to  ihc  j>eriphvrnl  side  of  the  jraagllM 
whow  the  wction  remains  ininct.  as  Aon  h!>o  the  rufi  of  the  root  ma  tbi 

Sanglion  to  the  spinal  conl.  but  in  the  mixed  nervotritnk  are  aeou  numffM* 
^noratcd  fibres,  which  whea  eiamined  are  fuund  to  have  the  dinribnlw* 
of  Mnsory  (afferent)  fibre*.  Lastly,  if  the  posterior  gaD|;lion  bo  exric*!.'** 
whole  posterior  root  dcgeneRit««,  as  d»  atso  the  sensory  (alTermi)  libm'» 
the  mixed  nerve-ttMnk.  Putting  alt  tli««e  facts  tof^tlier,  it  would  *eeai  ibil 
the  growth  of  the  eftorent  and  aUereni  fibres  takes  niaoe  in  opniieiu  'tirw- 
tiima.  and  »tarl  from  difterent  nutritive  or  "  trophic '  centnuv     Tlie  aAnn' 


TUB   ATBUCTrRE   OP  TUB   8PI.VAL  CORD. 


675 


■way  ftwRi  tlie  fninglion  cither  townnl  Htn  poritihery.  or  toward 

the  ifMiial  Mird.      Ttie  «l1erenl  libm  grow  oulwurd  from  the  iMtinl  con) 

tovani  ibe  [leripbery.      Tliio  ilitTercocc  in  their  Rivd«  of  nutrition  ia  ft«- 

()oniilr  of  i-reat  helpio  investigBtio^'  lh<-  roliil.ivixlistrlbiilion  of  Hferenl  aiul 

ucreut  6brea.     \Vh«u  a  poelerior  root  is  ciit  beyond  the  piDi;lioD.  or  the 

j[ut||;U(in  esvited,  nil  lite  allbreut  nerve  dc-geaeratv.  and  in  the  mixed  iicrve- 

hrauche*    ihete  aRereni  Hbres.  by  their  altered    condition,  can  reiblily  be 

Inml.    CnuverMly.  when  the  auterior  roote  are  cnt,  the  edereDl  fibrtti  alone 

ilqpDenUe,  and  can  be  •Liiuilarly  reoopiizied  in  a  mixed  nerve-tract.     Whoii 

■W  sntrrior  root  \»  iltvicKii  some  few  fibres  io  it  do  not,  like  the  rent,  dogen- 

nnuc,  and  when  the  [xsteriur  root  U  dirided,  a  few  fibres  iu  the  aoierior  n>ot 

atr  M«o  to  iWcneraie  like  thotu  of  the  posterior  root ;  these  appear  to  bu  lh« 

fibrr*  whlrh  ^ve  to  tlie  anterior  root  its  "  reirurrcnt  sensibility.'     In  the  one 

(iTrcrtain  •piual  iiervM  al  nil  elleeU,  it  hii»  alixi  been  asoertainiM)  that  whra 

the  posterior  rixrt  w  divided,  uhili-  most  of  the  flbrta  in  llif  part  of  tlie  root 

(hui<  cut  off  from  tbe  gatiglimi  but  Ivft  attached  to  the  mrd  dcgoncmle,  some 

few  do  uot.    Then  few  appear  to  iiare  thmr  trophic  centre  not  in  the  ean- 

^lion,  but  ID  some  part  of  the  »pinal  cord  itself;  we  shall  rufer  to  tSese 

later  on. 

This  method  of  distingiiishing  nerve  fibre*  by  the  features  of  their  degen- 
«mt*oa,  called  tbe  "degcncrsiion  mothixl."  or  somelinM*  from  the  name  of 
Ibe  phrsiologist  irho  inlroducwl  it,  tlio  "  Walterian  method."  has  proved  of 
f;nrat  utility.  Tbn«  iu  Ibe  vagus  nerve  which  is  composed  not  only  of  fibres 
which  spring  from  the  real  vagii»  root,  but  also  of  Hbres  proceedini;  from  the 
Bpioal  accessory  root*,  the  two  may  bo  distinguished  by  section  of  the  vaguit 
and  a|)iuBl  accosorv  roots  reftpectivcly.  We  shall  presently  see  that  this 
iDv(bo>)  may  be  apiilied  to  tbe  aifibren nation  of  tracts  of  fibres  iii  the  brain 
and  spinal  cord. 

TiiK  STBtrcTOBS  OF  TRK  SrntAt.  Cord. 

I S68.  Lying  within  the  vertebral  caniil  the  epiiial  conl  is  protected  hy 
ba  **  Rwinbnines,"  the  dura  mnter,  the  arai-bii<>i<l  motnhntne  and  the  pia 
■later.  Tbe  oonsidrratioa  of  the  arraii^vnu-til  of  th»e  membrance  and  of  ibe 
leun*  of  Ihc  dura  mater  and  tirochnoid  we  will  leave  until  we  cnme  to 
of  tbe  vascular  and  lymphatic  supplies  of  the  central  nervous  syatem ; 
histology  of  tbe  pia  mater  may  more  fitly  come  with  that  of  the  s]»iial 
rord  itself. 

Alouff  iu  whole  length  from  its  junction  with  the  bulb  to  iU  termination 
In  t)>e  jv/hih  terutiiu'ilr  the  spinal  cord,  while  poswetioK  certain  geuerni  fea- 
lurrs.  i«  eontinually  changing  as  to  apodal  featuree.  It  will  be  convenient 
to  Mady  tint  the  pi^enerai  structure  (if  *ome  particular  pari,  far  instanoo  tlie 
mi'ldlc  nftlie  tbomcic  (dorsal)'  region,  and  afterward  to  point  out  the  special 
fealurcv  which  obtain  in  the  aereral  regions. 

A  traiumnc  vertical  section  uf  eitlier  a  fresh  or  n  hardened  and  prc|>arol 

'  lal  oord  at  the  thoracic  regiau  pnaseww  an  oul3ine  which  ii,  roughly 

ting,  circular.    In  the  middit?  of  the  anterior  or  ventral  surface  is  a  ver- 

Satare,  the  vfnlntl  or  anlrrior  finare  (Fig.  174,  A.  F.)  running  some 

lll*twiil«ib»Wal**«(lietsrini"'lMwr'ft«i1"v>nmI"  Ijt  th*  ptitior  tlWnnlini-iMiHl 
*ii»  ■Mso  tig  ni>inaT»lr  naw  (be  4Dral«iiwli  i<ui.  ■oil  ike  Tenml  or  botlrun  of  (b*  boer, 
laria*Mnn*po<*t«Mriiii4knt«r|qr:  Inl  It  this  it  dua«.  IW  iw*  u[  ilia  witi  liormi  10  iltftWS 
I  «r  IM  OMtl  bMiraen  ik*  lambtr  ani  otrntal  ncknii  ii  apt  i'>  Ia*i4  lo  ooaPBiaii  i  bsoet 
bMMarfniawart  Uinnola,    ttthunx  nf  dfimal  •»]  ircati*)  tw  ai1»tfB<  bj^bab>«B»a 
,.  eBiesnntnlna  mif  r  riTinliaitjtwi  uMd  la 'Iciuiia oawar ibv  bMilsiid  maiwUigmi  (m 
[  Mi(iwlIt«V :  aiiMTlat  aiul  Matarlur  but  bIw  b«  awd  In  10*  isim  wnia  stM^i  la  lb*  <ua 
■rtnr  aiul  imartw  BtHiw  and  bM>.  whlob  Mtoi*  wan  Im  ■oak  aaa«Mil  br  <1B*  lo  b«  Ibnwn 


ST6 


THE    SPINAL   COHI). 

Fio.  171. 


A  Tkam.it,»6e  D'liiMi-vr.NTiiAL  Stmiis  OK  THE  Spinjl  Cori>  (Hi:mak)  at  Till  Level  or  tkeSiw 

TllOHACIC  (l>fR»ALI  Skbve.  (Shebbisotos.iI 
Ma^iiJIled  1,~>  liniL'?.  t  ini?  IniT^nil  balf  t>ii]y  l^  hlioxvn,  Tbu  large  »>i»pl<^uou>  nerriMwlla  idn"ii 
from  ik^IuhL  »-iH.'t'jii]L'1jsi  aru  shaded  blurk  to  rcndi^r  their  relLtivtf  size,  sbalicaiiil  poalllotl  monol* 
vli>us:  [licoiitllibv  of  iliegrBj'  riiHIIrr  lnnlpwn  uihiIc  ibluk  Bnd  r]»rk  In  order  toremU■^ltc<mfIJcDu^«■ 
A.  F..  fliitt'riiNr  i.r^ur^.'  i  I',  y.,  |^*ti'rior  n^pll^o  :  r,*^.^  oeiilrsl  catial ;  f,  ff.  *-,  centr»l  getatLtioua  tab- 
Malice:  A,  r.,  ririlirldr  rrjcit :  1'.  r.,  Inli'tnl  (or  Inlennedtatel  bundle  :  P.  r'.,  medlnti  bundle  or  poW- 
rii.T  root  <i[HiliiKl  iR-r*v  :  ;.',  j."  filin'?<if  i  isicri or  n ml  paning.  p' indirectly  through  tlw  fotaanwrf 
Utilaiiilo, )'"  ill  net  ly  into  itray  iiiHit^r;  rr,  'i,  /•.,  anterior  gny  Gommtnure:  p^  ff.  c,  potenor^nj 
ci^iniui^^ure  ;  t,  -■..  oiucriiir  Hhilt  coiiinki^snrv  ;  anK  cof.,  aulerior  column;  fa/,  eof..  lalen-L  coiun"'- 
pofl.  (■"'„  i-i-lvil-pi  i-.ilunm  ;  «.  ■/..  ihu  tulMance  of  Rolmido  ;  «,,  wptum  rD&rklQK  oul  the  eitinul 
Itofierlor  L-ohiiiiii  or  ivjliinm  oriluniacli,  c.p.,  from  Ibe  m^iari  ptielcrior  colomn.or  column  cftfvl- 
HI.  ;j.  1,  '"^11=  of  ihoiint^rior  Loni :  3,  pijsierior  column  or  reaicular  cylEnder.  or  oointnn  of  CTirke' 
Ihtf  BtfHof  thoijlliiijtri'dellnedbj  a  dotted  line:  1,  cells  of  the  intennedio-lateral  met  or  Wn*" 
trarl  or  lalefHl  liorn;  ii,  cilL"  ff  Ihe  |io-ierior  horn:  ",  cells  of  Ibe  anterior  cerrli;  y,  a  tracmf'i'''* 
iv^liig  l'ri.iL>  ilie  vesii'iiliin-jliiiik-T  III  tlie  lateral  culutun, 

way  Bcross  llie  llikkneBS  of  the  cord  from  the  ventral  toward  the  dowJ  f"" 
fece.  t)|»pijsiie  to  it  on  the  posterior  or  dorsal  Htirface  is  a  correBponaiogt 
deeper  but  n&rrover,  dorgal  or  posteritrr  JUsure  (Fig.  174,  P.  F.)  which,  bo^" 

I  Fur  tlii^  and  nninv -iHCniBllntr  flgun?*  I  am  deeply  Indeblfd  lomyfHendmnd  itonner  l*!^'' '*■ 
Slicmtnil"!!,  who  hu'- liUidly  pre[jflroa  llie  figiirtu  ft>rme  from  bis  original  drvwlngii 


wr«t  ibc  mli^nn«' (if  ihc  cm)  i*  reilopet)  lu  ■  iinrrow  uclimu!)  imiliu^  lh« 
Iwii  Isi^nl  liiilv'fs,  ntiich  in  »  nortiml  oord  are  like  eni'li  other  iti  nvery 
ntpttt.  In  iW  miilillf  uf  \hv  islhiiiiM  Wee  ilie  section  nf  a  dinuli  caiKil.  fA« 
flnulni/ miMi/  (Fig.  174,  r.r.),  whicii  is  itll  ibat  reinainHof  ilie  rcliitivdy  ivitk 
nnimt  autal  of  llio  «inbrvo. 

EsL'h  UcemJ  biilf  oorutMs  of  an  mitcr  zone  of  wkUe  mailer  surri)iini1!ntr< 
•ici'pi  nt  Ihe  istliRiiiB,  an  inner  more  or  leas  cnaceulie,  or  cammn-i<hii|ie<) 
■as  of  yr.iy  mailer.     Th«  oonvoxitv  of  «oh  crescent  iti  turned  lowanl  tlie 
meiliKti  )in«  nf  the  coni,  tite  liro  creacenta  being  pluoeil  buck  aui]  buck  ami 
juuied  lofceiher  by  the  isthmus  just  ipoken  of.    The  Minewhat  bniiMli.T  iiuie- 
nor  extremity  of  the  orescent,  or  head  of  the  comma,  u  called  the  arU«ru>r 
■vmii  or  ftom:  awl  the  narrower  jMsterior  cxtremilv  of  the  crotuent,  or  tail 
of  ilie  comma,  in  called  the  pMterior  eornu  or  hora.  ^he  part  by  which  cscb 
hnra  i»  joined  on  to  Ibe  middle  part  of  the  cTMceiit  ia  calkd  tbo  errvir,  ante- 
rior and  poaUnor  respectively.    The  i»Lhinits  joiitiog  tbe  back*  of  ihc  two 
croKvat*,  likt  the  oreaceota  theiuielves,  coniisui,  for  th<!  m<wi  part,  of  {rntT 
natter,  ibc  buod  ruuoinf;  potterior  ordorval  to  the  cciiiml  rannl  bcinfc  cailea  I 
tbe  jMifmor  ^roy  nmimunurf  {P'ijt- 1"4.  P-  7-  ".).  »nd  ihc  band  riinning  ante-l 
rior  or  ventral  to  the  canul  being  cnlleii  tne  atiltrwr  vniy  oommijuurt  (Pig>t 
174,  a,  g,  p.),     Tlw  iKNtU-riLir  li-uure  toiiohM  the  pocUnor  gray  coiamiMun^  r 
but  the  *nt«rior  gray  cotimiiwurr-  it  wparated  from  the  bottom  of  the  ante* 
rior  gray  commiMura  is  soraintnl  from  tbe  bottom  nf  tbe  anterior  liMoro  by 
a  hood  of  while  nuUter,callc4t  the  anterior  lehiu  emamuMtrt.or  more  -imply, 
ibc  trfiite  etimmimurr,  or  somclim**  llie  •inlcrwmmmi4»urf.  (Fig.  174,  n.  c). 

If  the  Miction  be  taken  at  the  level  of  the  origin  of  a  pair  of  spinal  nervns, 
il  irill  be  MCD  that  the  anterior  or  ventral  root,  piercinis  the  white  matter 
onpusitw  tbe  bead  of  the  comma  id  several  diaiincl  butnltca  { Fig.  17-1,  A.  r.), 
tUDnges  into  the  anterior  comu.  while  the  nonerior  or  doraat  nait  (Fig.  174, 
P.  r.,  P.  T.I.  having  tlie  appearance  of  a  rinf[le  undivided  bundle,  piL*M«,  in  |uirt 
at  loaM,  into  the  fitnUrwr  horo.  Uotb  roots  are  dbpened  length niir«  iilong  the 
<ord,  the  hinder  nxita  nfone  nen'e  being  clnoe  to  tbe  fbremOMt  rootaof  iho  nerve 
WInw.  butil  is  uiilytlx- anterior  rixit^  ntiich  arv  disserted  sidcwayt.    Tti><  com*  I 
pact  bnndli'  nf  tbe  poMCrinr  ruoi  dividiv.  with  tolerable  sliorpDess,  the  white  j 
matter  in  vach  laiernl  lialf  of  the  conl  into  a  [xjvterior  poriioiii  lyine  botweeB' 
tbe  pii*leri')r  titnuro  and  the  potterior  root  ( Fiti.  17.1,  juitt.  eol. ),  which  portion 
Btnci*,  ••  <•'(-  ■hall  'vv,  it  runs  in  the  f-trm  uf  a  mliimn  ainug  the  Icngtli  of 
the  coni,  iscalltvl  ihe/iiMterior  eo/umn.and  into  a  portion  lying  Iotheouldd4rJ 
of  ih*'  pintoriur  rnot  between  it  oimI  tW  anterior  tistmiru,  called  ihe  unCenM 
hlrriil  ftlMMn.    This  Isilor  may  bo  eooitdcred  as  fiinher  divideil,  by  xhtn 
enlrancfof  the  siilcriorroot;>  into  m  iat^rat  oatumii  (Fig.  174,  b/.  iy>/.}  IwtWMnl 
tbe  [Hwterior  root  and  the  moHl  external  bundle  of  the  anterior  root,  ai»l  int»] 
an  ualrrinr  fJumH  (Fig.  174,  'iir(.  Co/.)  between  ll»0  anterior  fiwiiro  unit  the 
moet  external  kun<lte  of  tbe  anterior  root.    The  {Htrl  trarerted  by  the  bun- 
dlea  of  the  anterior  root,  as  they  make  for  tbe  anterior  liom.  sooordin^ly 
helonirs  tu  the  anterior  column  ;  but  tome  writers  speak  of  the  nntenor  ' 
oohinin  a*  Iving  hetwccii  the  anterior  ItsNirc  and  the  nearest  bundle  of 
anterior  ro'il,  thus  making  ihe  rei^ion  of  the  anterior  root  belong  to  neither 
auterinr  ui>r  lateral  column.     And  indeed  (he  diolinction  betwceD  ihe  ant 
rior  nud  llic  lateral  cititimn  U,  to  a  great  extcnl,  an  artilicial  diatinclion. 

1 064.  Thr  "  while  matter "  ooiuaBU  exduMvely  of  meduUaied  fibres  sai 
ported  (larilv  by  ci>un>H'tive  tissue  and  partly  by  a  peculwr  tiMue  known  : 
neMfwT/i'n,  <Ywhich  we  ■hull  presently  st>eak.     Tbe  Bbres  are  of  variotnsix 
biUBHiny  of  ihviH  are  lurgv,  iuhI  m  all  of  them  tli«  medulla  is cuntpicnti 


m 


THE    SriXAL   CORD, 


Tbey  run  for  the  nuMC  purl  luii](itt»linally,  w>  thai  in  (raimTene  t*t%io 
the  cord  dmHy  i1i«  wtKili;  of  tli«  «faii«  mailer  a]>peiirH  uiider  the  mW 
lobacompOHtlof  iniuulircircloi',  tbo  traiuivt-FMr  tH.'<XKiDi>  of  lltp  loiigilu<^i  < 
diapuocd  Bbm,  imln^dcil  in  tlio  Mi|)jM)rliu]i  !>[ructurt».  The  "  gnr  ti.^n  i  ■ 
also  coDtaina  metlulUtifl  lH>m,  Uit  thi-M-  nrtr  for  ibe  ninat  |>nrt  4.-s<r"li:ij; 
line  fibres  pomemng  a  inedulla  which  n|ii><Mire  lo  diRir  frtitn  Ihat  •■fu 
ordinary  m-rve'fibrp,  «*□(«  it  dot«  ik>1  tXnhi  n-iidilv  with  oatnic  acid,  but » 
rcmiered  visible  bv  s)>ecial  modea  of  pniparalioD  each  m  tbai  known  u 
Weigeri'e.  Hcnci-  ilivM  fiiw  Itbrea  are  not  appnrtnt  in  ••rdinart-  camuMm 
other  apeciinau,  and  indeed  (heir  presence  wa*  for  n  long  time  uverU-kpl 
Beaidee  tbeae  fine  mcdullated  fibrw.  if  «l'  ntny  cull  Ihen  stich,  the  em 
maUer  caD(&in»,  vbal  iW  while  matler  does  doI.  nerve-oells  irith  bnuxniog 
prooe««m,  nak^d  aiie-cvtiDdere,  end  delii'ale  lilaoKDls  ariaiug  front  tbt 
division  of  axis-crlindera  or  Ironi  the  bmnchiiif*  of  nerve-cells,  all  thl« 
viiritius  atrudures  being  iinbeddett  in  iteuroelia.  Uwing  to  the  relatir* 
nbuiMlanee  of  the  ivhile  refractive  medulla,  llw  white  matter  pcaaiam  in 
(Veak  apecimens  a  oharaolerisiii;.  opaque  white  color ;  hence  the  nanic  Tbt 
gray  matter  Irom  the  relative  acantinees  of  medulla  Itas  no  woh  opaijiF 
whitenew,  is  much  mi>re  transluoeni,  and  in  flreah  specimeDH  hu  a  gny  <« 
rather  pinkiitb-i^ray  color,  the  mlUh  (iut  Wing  due  tti  tbe  pm-ciKv  i«rlU'  of 
pigment  and  partly  of  hloud,  Tor  the  bloodve«els  are  much  mure  abuDtlul 
in  (he  gray  matter  iban  in  the  white. 

Tbe  jtin  inatcr  which  eluseJy  invents  the  cord  all  anMind  c«in»i*t'  nf  iiah 
ncctive  liicue,  fairly  rich  in  elasli*^  elenn-nls  nnd  nbiiiidanity  sLipjilinl  uilb 
bloodvcHcIs;  it  in  indeed  vsMcnlially  »  vn»-iiUr  mfmbram-  nrnl  (iiniisbte  iW 
nervous  elvinuDlN  of  the  curd  nith  their  chi«f  supply  of  bhxid.  Il  wnd*  ia 
m  intervals  parliuons  or  MpUt  of  lUr  same  nature  as  ilsclf  mdinliiiK  I'luanl 
tJie  oeotral  gray  matter.  The  luirron'  ikmIcHot  tusure  is  completely  fillnl  vf 
by  a  large  Mptuni  of  this  kind,  indeed  as  ue  have  said  is  in  reality  not  a 
fieaure  but  n  inrm  t«ptnm  :  but  the  nnterinr  fissure  ii  too  wide  for  sueh  m 
arrangement;  the  wbute  membrane  dips  down  into  this  fissutv.  f!)U'iiiiai;  lli* 
surface  of  the  cold  and  being  reHocted  at  the  bottom.  FMni  lhe«e  pfi'tiur< 
aepta,  secondary  5ner  sepln  still  compofcd  of  ordinary  fibrillnted  cutit 

tissue,  carrying  bloodveHcIs,  branch  off;  liut  these  are  soou  uierL'ol  iiii 

|ieculiar  supporting  tissue  called,  as  we  have  said,  ueurolgis,  'Ibii  out"'- 
in  the  first  place  of  small  branchiu]*  cells,  lying  in  veriowi  plnnra.  i^ 
branching  in  exeesuve.  so  that  the  budv  »f  ibe  cell  is  reducrd  to  very  twall 
dimenniuns,  indeed  at  times  alnnst  ul)liieraied,  (he  nucleun  ili)Ui|ii]ieit(iB|t 
w  hilc  the  uumAous  brancbett  are  continued  ns  loDg,  fine  rdantcni*  or  (!<>■** 
|Miniiing  a  devious  but  for  tlie  moat  pan  a  Itingiludinal  eotir^^i.  In  lie 
aecvud   place  (bfse  cells  and  fibiw  or  filunicnls  arv  inilHiUicil  in  a  lionw- 

SOCOUS  gnutui  substance.  Relativclv  lo  the  librvn  and  ground  siih«uaR 
I  bodies  of  the  cells  (which  arc  culled  IX-iler's  evils?,  e«|N-ciHlly  bri-liw  s>t^ 
as  bear  obvious  nuclei,  are  very  scuuty ;  hence  in  sH'tions.  egpe-HsIlt  la 
transvenw  sections,  of  tbi^  coni  lite  neuroglia  has  often  a  dotteil  >>r  piind*)'*! 
Bupearance,  the  dots  being  the  (ninevem  Mclions  of  ihc  Hue,  lon>:iiu<liiMlir- 
dupoaed  fibres  imbedded  in  the  ground  subMaiwe.  Examined  chentialf.*'- 
the  neuroKlia  is  found  to  be  oompOBed  not  like  oonnective  tismie  uf  pUU'j 
but  of  n  substance  which  appears  to  l>e  olosely  allied  lo  keratin.  ihctM^ 
r(>n»liiuei)t  of  horny  epidermis,  hairs  and  tlie  like,  ^  43G,  and  nlikh 
tliercfiire  been  called  neurotrratiu  i  see  also  §  OS),  And  indeed  this  dmir^ 
llitiugli  like  c^neclive  tissue  a  siimxirting  structure,  is  nut,  like  et'naHii' 
ti»ne,  of  racaublnslic.  but  of  epibliutie  origin.  The  walls  of  ibv  DM" 
canal  of  the  enibfyo  which  are  Irauxformvil  into  (he  spinal  Ci>rd  of  th*  *>l*| 
cunsirt  at  finit  of  epilhelia),  epibliuAM  oelli ;  nwl  irhile  some  of  ibxc  i 


'.sill 


THE    SPIXAl.   CORD. 

ttccome  niTvoii*  flcnwtii*,  mbcra  bocuiue  iietiroglia.  The  cjiiihdiiil  cclb 
wbich  are  i)«»uii«il  tu  Ibnu  iieiiroglui  becutue  exi-Milinglr  linincbtil,  vrbile 
their  origin  ully  prmtojilntimic  cell  »nb*taiKc  become*  truuMlunucd  ton  Inrgo 
esftil  iiitd  nciirokvniiiii. 

The  Bciinwlim  liltii  up  lb«  ii|iiicM  Wtwrru  iho  niiliAting  Inrgcr  iwptnl  pro- 

loogUMD*  nribe  jiiu  niulcr  nint  llirtiiirr  bniiic'hi:'il  ncpla  vrhicn  (tntlitig  frvta 

th«  larftvr  nnn  cnrry  minuiv  bl<i<>lvi-:«M.'l«  iiiLu  the  iotcriur  qf  the  wbiie 

niAll^r.     In  ihtte  *\mcv*  it  i*  m>  nrraiig>.-<l  ii«  to  form  rl«licn(«  tubiilnr  canals, 

of  nty  vnriflbli-  *iii-,  ninning  for  lliv  niuBt  rinrt  in  ft  loDeillidinnl  diivclMMi, 

GkH  of  Uu-M-  iiibuUr  ninaTs  is  neciipii-i)   l>r  and  wbollr  fillt't)  up  n-ith  ft 

■odallated  nvrvi-libmor  cnrmpnniling  fir«.     A  medultatwl  ni^rvc-librp  "f 

Uw  wbiu  nutUir  of  the  Bpiiinl  cvri)  rc>feniblr»  a  ini^lullaUNl  iK-is-^Hhre  ut'  h 

Mrv«  ((  SK)  in  beini;  coinpoM^  of  sn  usifl-iylimkT  ami  a  niedulln  ;  but  il 

pCNBonM  no  ]>riRiitive  *h«nlh  or  neurilenimn.     This  is  absent  and  indeed  is 

aoc  wnntMl ;  the  tubular  »hcatb  of  neuroglia  alTordF  in  the  «pinal  cord  tand 

as  ««  shall  see  in  the  cenlnil  nervous  sfstem  gvoersUy)  the  8U]>port  which  in 

•  iMrv«  m  afloHed  by  iIh  neurileninia.     Nodes  are,  according  to  tnost  authors, 

abeeni,  but  some  say  they  are  preeeuL 

The  while  matter  of  liie  curd  consists  Iheu  of  a  more  or  less  solid  inaaMof 
■Muroglia,  hitviuy  ilie  stTueture  just  described,  irbicb  is  pcrineated  by  minute 
oaala,  aotue  exceed inj-ly  Hue  Hnd  carrying  verv  Hoe  2^  fibres,  other!)  lur)(er 
and  rarryinjc  l)bn.ii  U|i  to  the  ■lie  of  15  ".  Thu  moss  is  further  brukeii  up 
into  areas  by  thi'sinaUvr  and  larger  vavcubir  conneclire-liwue  M;])ta  with  the 
cdgt*  und  ciidiugw  uf  whicli  the  ntHiro^lia  in  M)ntiiiui>u>.  Most  of  tlw  iK-rve> 
flbna,  ax  >v  hiivc  said,  run  longiliiilinsllr  and  in  a  transverse  section  of  the 
conl  nri'  cut  Iran.iversely  ;  but  ns  we  shall  aeo  fibrts  are  cuntinually  pCMiig 
iniu  aiMi  nut  lit"  ibe  while  Rinltcri  nnil  in  sij  dtdng  take  a  more  or  li^m  traoa* 
ver>«  cunrH.';  ihcM',  bonrver,  arc  few  oompnred  witli  thi<ie  nhirh  run  in  a 
lon^ludiiinl  ilirection.  On  the  oulaide  of  the  curd  below  the  pin  maler  the 
neuroc'i'  is  developed  into  a  layer  of  some  thicknwi  from  whii^h  nerve-fibres 
■»  kiMMit :  this  is  often  siHikcn  of  as  an  inner  layer  of  the  pia  maler ;  but 
being  netiruiglia  and  not  connective  tissue  is  of  n  difliircnt  nature  Ircim  the 
|iui  maUT  profier.  A  layer  of  this  Mijwrlicia]  neuroglia  also  accomjianies 
ibtf  larffer  KiKa,  and  a  considemhle  cjuaQtiiy  is  present  in  the  lar|^  se)Kuni 
tallrd  the  pusieriur  fissure. 

The  |>ia  mater  carries  uot  only  bloodi.'eMela  but  also  Iviupbaticti :  of  these, 
homver,  we  lihall  speak  when  we  come  i<>  deal  with  tiie  vateu  la  r  arrange - 
BMDU  of  the  whole  of  the  central  nervous  system. 

(  566.  In  tbv  m-ray  matter  ne  may  dBilinguiah  the  larger,  more  eouspiruiiiiB 
aenrr-fvlli'  and  the  rntt  nf  lh<-  gniy  maiter  in  nhirh  ihcse  eelU  lie.  We 
bare  alremly  H  dU)  devoribed  the  general  features  uf  theae  lai]ger  nerre-rells. 
and  sliall  have  presently  to  speak  of  their  ;i|M.-cial  characters  ood  groupiug. 
>l)-nnwhile  the  mwl  important  jioint  to  remember  about  tbem  boiMi.?  tlH^ 
lJS4-t  llial  titey  vary  Inr^-ly  in  fonu  and  size  t*  that  while  one  procna  may  or 
doca  become  aii  axi^eylindiT  of  a  nerve-fibre,  the  ulbers  rapidly  hraiicli,  and 
brwkin^  up  into  fine  nerve  filaments  are  luft  to  view  in  the  re^^t  of  tbc  gmy 
matter. 

Tliesp  lari^vr  nerve-cells  f<im),  boircvcr,  a  part  only,  aud  in  moot  rvj^on*  of 
v  cord  llui  siiudlor  part,  of  Ihe  whole  gray  initllvr.     In  a  Irantverse  section 
Dm  the  tlionieic  rvginn  '  Fig.  174 )  ■  few  only  of  tbcsv  larger  n«rve-c«lli>  nru 
in  the  whole  sex-tton.  and  thoUL'h  they  awiear  m<>rr  numerous  in  te*.-- 
I  fVoni  Ihe  cervical  and  «<>()ccinlly  from  the  lumbar  region*  (Figs.  167, 
177),  yet  in  all  coses  iliey  occupy  the  smaller  purl  of  the  area  of  ine  gmy 
Miter.    The  lartrer  \t»n  ol  the  urny  mailer  consiato,  bvM<les  a  neur>;f;lin 
npirarting  the  nervous  ekoMOta,  of  nuni'e  filameiila  running  in  various  dirvo- 


i 


680 


THE  SPIX3 


lionn  nnii  funnitijr,  ivol  k  pkxuA  projiwrly  s-^mlk-il.  but  ni)  iiiicrlvwmmi  "t 
exiretiii'  <'i<iii|i]exily.  Thf«e  filamenlfl  are,  on  llie  oik'  Iihih).  llie  liiw  ntnlul- 
Iwwl  litiriK  -ijHikMi  I'f  ab'ive  lu  beiiiB  rvL-ngtiiMi)  with  tliffii-uliy,  nnd.  i>n  tfa» 
•Aher  linuil,  m in -nii-ilu listed  filamuita  niiiKiiiK  Tr^ni  rmrly  nidc  snH  coD- 
a|iiouoiin  nakod  axi>-cvliii(Iirn>  iliiwn  U>  tihrib  of  cxtronto  cvnuitjr,  the  UUer 
nrisinc  iippnrently  Httii-r  from  [h«  <livii>iiii)  nf  nKiit-cylltKlen'  nf  ncrre  fibm 
p»»inj{  inl'i  iir  tint  of  tliv  ^Tay  ninttvr  or  Inim  the  cviniiniii^l  bra(i('liiii>:  of 

[tr\KV3sat  of  iiitrve-i'elljt  Ity  llir  mniUv  nf  |)fv[K(riition  i>ow  nvMilnblc  it  hiw 
Mi-n  iihim'fi  lliat  tlii«  ()ii«  nH-dtjIliitt-i)  tiliriv,  «(i  fur  friiiti  h^ng  nir*'.  an  in 
«-rt«in  \mrlr  nf  tlip  fcnv  ninllcr  nn  Mlxintlnni  im  cvem  Ui  prtpoti<ii*n»lv  ovrr 
lli«  iioii-in«'ilullnUi)  fibni'  or  tibrilR.  T^slly.  bciqiln  the  conspicuous  nvrrp- 
<'i-H»  jpnkrn  of  nhovc.  which,  though  of  mrinus  nies,  may  nil  pi-rhap  be 
i'pdkrii  of  lis  Inrgv,  a  very  Jar^'  niinil)«r  of  other  cell*  of  •mall  riw.  l^•in^^•  of 
which  ni  nil  events  mii«(  be  rcgurHpd  as  true  nQrTe-c«ll^  nn>  prvKnl  in  the 
gray  matter. 

The  neiiroglin  in  which  all  thee«  Mniclum,  nerves-ell-,  fine  tneiliillntpil 
nerve' tibree.  nnlccil  axis-crlinders,  and  line  KlnmeniB  are  imbi-dde<l,  U  iilcttticnl 
ill  iT»  '.^eiieml  chiircierti  with  thst  of  the  while  mutter,  Ihii,  iif^  iiaiiiriillv  fol- 
lows fVi)m  the  naiureof  the  uervoiis  elements  which  it  «up)Miri8.  iit  dilli-fviitly 
arran^l,  Inxlead  of  forming;  it  srtilem  of  tubular  vhaiinels  it  tak«  nu  iIm> 
fonu  of  a  Biionj,'e-work  willi  larj,'*'  spacee  ll>r  itie  lar^r  nen'e-eolU  and  fior 
pa»a|ies  for  the  nervoiia  filaoienla  At  the  jiint-tiiiii  of  ihe  gny  mutter  vith 
the  while  nmtter.  the  ne»ro)[lia  of  the  one  in  continuous  with  thai  of  ih« 
oiber,  and  the  ei>imociive-ii«ue  sejita  of  the  latter  mn  riKht  into  tbefornxr: 
the  iniiltne  of  (he  firny  niatier  i»  ii<tt  iiniiKiili  and  even,  but  l>mkei)  hy  loolfa- 
like  proccoKadue  to  the  tiepta.  .Since,  m  vre  havejiut  Mid.aome  of  th»  IrtM 
nerve-cella  are  very  small,  and  nitice  the  ncrre-filainenut  like  ihi<  nmm^lia 
A\iTv*  arft  vn-y  f!n«  am)  take  lik«  iJiom  an  irn-gular  nwir»e.  it  ofiva  )>eci>mM 
wry  difltcull  in  a  Miction  to  determine  exactly  which  ia  neuroglia  and  whlcli 
are  ncrvou«  clcTne»t«.  The  ncnroglic  orlU  may.  hone\'cr.  bedifitiD;;uish«d  |wr- 
hape  from  the  smaller  nervc-cell»  bviheir  nuclei  not  being  eo  conspicuoua  or 
»o  relatively  large  ns  in  n  ncrvo-celf,  and  by  their  siaiiiin;;  diflerentlr. 

The  gray  matter  then  may  lie  brriadly  described  as  a  beil  of  nearoglia, 
cotriaimng  n  certain  number  of  bnuiching  nervc'celli).  for  tlw  muM  |MR 
though  not  exclueivelr  large  and  conspicuouti.  but  chiellv  iKrupied  by  vrlinl 
ia  Dot  so  much  a  pfexu^  as  an  intricate  inleriveaving  nf  nerve- li lament* 
ninninji;  apparently  in  all  directions,  ^me  of  llitae  ftlamenta  arefuirlvcm 
xriicuoiin  naked  axi»f cylinders,  and  a  few  are  easilr  reco^roiied  molu^la 
Sbna  of  ordinary  iiw?;  but  by  far  the  greater  numtier  are  either  exceiidini'Ij 
line  medullated  fibres,  wh(«e  medulla  is  ouly  made  evident  lir  ft[iccinl  m>Kt«»' 
of  prrparalion,  or  delicate  fibriU  devoid  of  medulla.  With  the  D«rvou«  web 
formed  by  ihc*e  Blaructitji  the  brauohiog  proonKS  of  the  oerve-eelU,  on  the 
one  hand,  nud  the  divitious  of  nerve-Hores  pa»siiti(  into  or  out  of  ibt*  gmr 
mutter,  on  tin-  other  hand,  appear  lo  he  conlinuoua.  It  may  l>e  «i)detl  that 
(he  grny  matter  it  well  mipplied  with  IdooiIvcawU.  tbeae  }mn]i;  in  it,  nt  atnteil 
nb).)ve.  ndnlively  much  more  numerous  than  in  the  while  mnit^r. 
r  i  S66.  The  cenlmt  canal  in  lim-il  by  a  Mn^le  layer  of  columnar  epithelial 
eel  Ik.  which  are  generally  dcccrilicd  nu  beariiit:  cilia;  but  i[  lit  not  i.>3nain 
that  the  proccMw  which  may  Iw  «H'n  pnijccliug  fmm  the  mrfaoM  of  tbe 
rella  are  really  cilia.  Thew  epithelial  celln  rvA  not  <>n  a  diMlincl  boaemeni 
membrane,  but  on  n  bed  of  neuroglia,  free  uppurenllv,  or  »<<nrly  tn.  frmi 
nervoitB  elemenie  which  Riirroiinds  the  cenlnil  canal  anif  i»  »omctimt»  (iio-keiii 
of  n»  the  mhil'jitli'i  'iflntinota  nrnlraiit  (Fig.  174.  r.  t- ','<■  Tlio  atlnrlteil' 
basM  of  the  epithelial  o-ll»  are  bnincheil  or  taper  to  a  HInmrnt,  and  1>erome 
CoutiuuouB  with  the  brniieheil  celU  or  hbrva  of  llie  neuroglia  lieloiv.     As  we 


■nta 


I 

I 
I 


I 


I 


I 


TIIK   STKUCTUnE    OP    TItK    SPIXAL   CORll. 

•kid  ftbow,  the  nciiroglin  I'liMncnbt  iirr  lrnn'<f<>nDC-il  vpUhcltjil  celti ;  mk)  tbe 
notiDalir  attim  nib.  which  n-lninitii^  l)i*'  cliiiriiitli^r*  of  uiiithdiBl  oelb  form 
%  Icniug  t»  lli«  miih),  trilti  lliv  i'i;lli>  nhiuh  liiivc  becumo  unmched  xud  loM 
thrir  *'pith<'lial  chanicli-re,  iii'licalM  llxi  i^pilhclinl  origin  of  (hr  litli^r. 

Tb*  cviilml  nuinl  nilh  llir  rurroiindiag  amof  nniroslis  forma  tlx!  twotral 
jttfl  of  ili«  )*tliiiiU8  iiiiilin)^  (ho  Iwo  Inicral  hnlv«  of  thi;  conl.  Fiwicrior 
iiarm])  U>  tUi*  cenlrni  tnltm  lir«  ths  pn4erior  ymy  eommiimiiY^  (Ftg».  174, 
liO.  177,  p.  g.  (^>,  ooiopoMiJ  i.'hi«riy  of  fino  fiUmenU  ninniti};  trnnavcnelf, 
amt  uilvnor  (v«ntnil)  to  it  linn  lirat  Uie  tliiniier  anUruir  gr-iii  eummMar* 
(FisL  174.  179,  177,  a.  7.  ir.)  of  a  einiiUr  naiure,  tiiiil  ihcii  iht  rrlnlivclv 
lU»  irAi/r  rtiaunt^art  (Fi^  174.  176, 1  iT,  11.  e.)  irhicli  ta  formed  by  imwlul- 
IMmI  libm  criisiing  over  froTii  oae  side  uf  ihe  t.'onl  to  the  other,  and  lliu» 
OMHthiilu  M  dcci»iHil)oD  of  tibrce  alon);  ibe  whok  len^'th  of  the  mnl.  On 
tMoh  aide  the  central  mass  of  neuro{>lin  of  which  we  are  aponking  enidually 
DiMKW  into  the  central  yray  otaiter  of  the  eorresiioDdiDK  Uterul  lialf, 

Tbe  end  or  bead  (caput),  aa  it  in  freijuently  call«il  of  tbe  pueieriur  born  in 
•>ct^pie<l  no<  hy  itnliuiiry  tcray  matter,  but  by  a  {wouliar  liaaue,  tbe  tuiManlia 
yrtMiinntn  of  /totiHilo,  wliic-h  forRU  a  aort  of  cap  to  the  ruore  ordioary  grav 
matter,  but  dilfi'ia  id  uu  and  shape  in  diflVrent  rejjinns  of  the  twrd.  (  Cf. 
Pisa.  1 74,  1 75,  1 7<t,  ».  y.)  In  carmine  and  Aoine  other  modes  of  prepamiiaii 
it  b  fVvqueutly  iiained  more  deeply  than  it  the  ordinary  crar  matter,  and  in 
siich  premraiionn  i*  very  ootiKpicuous,  It  niav  be  deaeribed  aa  conxiatiiis  of 
B  MHDewhnt  )Kculiar  ueiiro^Hn  iraveracd  bv  liGre*  of  the  poMerinr  nxrt,  aod 
ctNitainin^  a  larj^v  number  of  eclU  irhtcb,  ^ur  the  moat  part  Nnall.  llie  cell- 
biKliea  betng  small  relatively  to  tlio  itiiclei,  are  not  all  nlilte.  unme  lieing 
pnbably  nervoui  and  others  not.  It  iak<«  origin  from  tbt-  cclU  formiuji  (he 
immediate  mlU  of  the  embryonic  mmlullnrv  canal.  In  tbe  embryo,  (hii 
cwtai  b  rolatirely  uide.  ihongli  coniprvswcd  rn>m  Mdc  to  »iili-,  and  in  tran»- 
tvne  wcUoni  of  ih«'  miyliillary  tube  appears  at  a  certain  «tftce  lu  a  narrow 
oral  ulit  nlace<l  vertically  and  reaching  atmodt  from  the  donallo  the  va'Dtrsl 
turfkce.  The  donal  pan  of  this  lon^;  »lit  is  later  on  ct(»cd  up  by  the  coming 
tggetlMr  of  the  iralls  and  tbe  obliteration  of  the  i-renter  pari  of  tbr  cavity, 
baring  the  ventral  [tori  to  furiii  a  circular  canal,  tvbicb  bv  tbe  development 
of  the  anterior  columns  assuraea  Lli«  central  pOMtion.  During  tbia  clo«ire 
of  tbe  dorsal  part  of  tbe  canal  a  mass  of  the  oelb  liDinjt  tbe  canal  is  cut 
flvm  the  r<~it  on  eacb  ude,  and  during  the  aubseqaent  Kruwth  takes  up  a 
fwsillon  ai  il»e  end  of  the  posterior  horn.  Hence,  (hou^h  it  never  appar- 
ently oiuiains  any  cavity,  (be  gulistauoe  of  Kolandi)  may  be  regarded  as  an 
ianlnted  ik-nion  of  (he  wnlU  of  the  n>eduUary  canal,  which  ban  undergone  a 
developmeni  «nmewhnt  diflereut  from  that  of  tbe  |Kirti<)n  which  remains  as 
Hm  lini»i(  uf  tbe  central  canal.  Trace*  of  thia  origin  may  he  acen  even  in 
tbe  ailalt.  Tbux,  in  the  lower  end  of  the  oord,  in  what  we  »ball  tpenk  of 
prvacntly  n  the  ooittu  writHUnnt,  the  central  canal  widen*  otil  out  domally. 
and  in  leclion  (Fig.  17o,  A)  priwnt*  on  each  itidi'  11  Iwy  r  xtrvtching  out 
towanl  tht-  piuiliim  of  ibc  [HMtrrior  born.  At  ihi*  region  of  tlie  oord,  thMlgh 
tmtb  while  and  gray  malti-r  iircdcvcloitcd  cm  the  ventral  »iirfaoa.lh4  iWMerior 
ooluunsdo  not  meet  OD  the  dorml  nirruce,  hut  lwivetl>o  centml  canal  covon^ 
enly  by  ti»uo  which  perhaps  may  be  called  neaniglia.  but  u  of  jx'cuiiar 
natun-  aiht  origin.  In  (he  cidf,  in  a  pari  of  the  dorsal  region  llic  «ubitaoc« 
of  Rolandii  is  not  confined  t<>  the  lip  of  ifao  |>oitleri»r  horn,  but  is  oonttnood 
tu  mosit  it«  fcllofT  in  th<'  iiiiddlo  line.  (Pig-  17-5.  It.)  If  wc  imagine  the 
doml  portion  of  ibe  caiud  of  .\  to  be  c«t  off  from  tbe  ventral  portion,  ita 
eavltr  la  be  oblilcntcx).  and  tbe  lining  epithelium  with  <ome  of  tbe  enr- 
niunding  elements  to  utulergo  a  H|)ectai  development,  the  condition  in  B  is 
ranched  by  tbe  growth  of  the  posterior  calumiw.    From  B  ibe  transition  to 


482 


TilB  BPIHA1.  C0H11. 


Uw  normni  state  or  iblnei  n  !ii  Pig.  1 7o.  r,  U  b  very  slight  une.  The  cxtrtiu 
dofMl  tip  of  the  lioni,  hoiDK  of  a  more  open  texture  ibMi  (h«  Fulnuor*  a/ 
Rolttndo,  in  somi-limiH  culled  tbe  imn  tpon^wta. 


no.  I?*. 


A  8  C 

tnwiiua  TO  iLU-fiiiAii  mti  Naivki!  or  mt  iKmimn  •)•  ltoti!>i<o. 

nellinmftMTiiireli  ^lamwBiuilonilatvn-iidmwii  i«  Uw auaa  Kah.  liiHll  ihnviifiraiM 
gnqi  OMWr  W  (httdad  aiUi  Hln  Unanikl  Uw  wbtlv  loMMr  villi  ittn. 

A.  truwnnc  wMloo  of  the  Iuboc  md  or  llie  enaai  ««)l«lbitt>  Id  bib:  r.«plk*tliuBbMa«ir 
Mtdollur  ouuU ;  r.  IsMnl  cx|niirino  oT  Un  ouul ;  B,  uaMnn*  n«ltani»niwa|4Ml«M4"riki 
valf  In  Un  hmor  ihcmck  K^«a:  r,nbHU«eaf  Motentoi  cMMntViMl:  <:,  imbmdm  mctm 
thioush  mld-fkBCHtlr  rcfloa  irfatrd  la  mui. 

iSM7.  The  grouping  of  the  uerw-etlU.    The  Derve-cella.  at  all  ereautlit 
nils  wbich  are  larj^e  coough  to  be  eiisily  mid  vriihoiit  doubt  reco|{iuteil  M  Ik 
Derve-oella,  foru,  tut  vre  have  seen,  only  a  pHri  of  the  (^y  matter,  anil  <<■ 
WHDe  pans  of  lli«  oord,  in  tlie  (liomcic  regioD  for  instauce,  ara  »o  Hfmm  thtX 
in  »  section  of  tl)«  spinal  cord  in  llii»  region  thin  eaougb  to  shnvc  it*  liitiu- 
liVi<'Jtl  ft^alUKft  »ali»fiu-li>rtly,  th«  bodies  of  a  few  only  of  oucli  celb  an:  vittiUt 
(Pig.  174) ;  tbe  grailur  jinrt  of  the  gray  matter  comists  itot  of  tbe  Uolin  i^ 
coDipicuoua  Do-vc-a-llti.  but  of  a  inai«  of  fihrea  and  Rbrils  pawiuft  apiurtsilr 
lu  an  dlrcctioUM.     In  the  ccrvieal  (Fig.  176!,  and  especially  in  the  lunb^ 
(Fig.  177)  rvgiona,  tlw  nervii-cella  are  bolh  aliaidiitely  and  rvlmtvcly  nwr 
abundant:  )>ut  even  in  a  »<xtioD  Inlcfn  from  l)i«  luiutiar  region  tbe  Der%^ 
cdlK.  all  tHit  logctbcr,  form  the  uualli-r  |Virt  of  the  ubule  area  of  v^r 
matter.     Moreover,  in  mpoct  of  th«  number  of  ocll«.  all  LbeMcti»u«  '' 
the  fame  region  of  the  cord  are  not  aliko.    Seeing  ibat  tbe  cord  niii>  ' 
Htilencd  a>  growing  ctit  of  tbo  fusiiui  of  a  aerie*  of  jNiirct  ganglia,  eiuli  ft*- 
elion  carrapondtRg  lo  ■  nerve  (<■/.  $  96},  w«  may  luirty  cx|ii.-<rt  to  fiud  !h> 
niiion  not  complete,  »>  that  the  narve-celU  would  ap]>ear  own  ni:  < 
opposite  a  nerve  than  in  ibe  middle  betwitMi  two  nerves.     In  sonti  < 
lou'or  animal»  ibis  urrangcnicnt  if  woU  ohvtou*.  and  lh«r»  ar«  liome  n«««' 
for  tbiuking  that  even  in  man  the  nert'o^U  aro  mtumvrkally  iucimunl  ti 
the  level  of  eaob  nerve. 

Even  ubeu  caaUHlly  observed,  tt  i»  obvious  that  th«  nerve-cells  atv  a** 
acatured  in  a  wholly  irregular  manner  tbroughoul  the  gray  malier.  Ixuu:' 
ibr  hutAuco,  much  more  conspicuous  in  tbe  anterior  born  thou  I'lievVn' 
and  nwro  careful  obser\-«tioa  atlon-«  us  to  arrange  Utetn  to  a  cvriuin  rxtriit 
in  eri>U|M. 

The  etU*  of  the  uutmor  hvm  are  for  the  moat  jwrt  large  and  i:ciiupicuiiii*r 
tiTA  to  V-i^f  in  diameter,  branob  out  in  various  direetioiiH,  ami  pr^^rot  m 
irregular  outline  iu  wciiona  taken  in  dilfereiit  pIaiK-«.  Wi-  biivv  khv  |" 
ihinK  that  every  one  of  tliein  posaestea  au  axt»-cyliud«r  pn>vcN>.  vcbiAiu 
llie  caoe  at  all  events  of  must  of  tlie  cells,  iiaaaiug  otit  of  ibe  firay  aa,i>t 
beoomee  a  fibre  of  the  adjairenl  anterior  root.  They  are  ubvi<tii;i  mi-l 
apioiiOUB  in  all  regions  of  the  coni,  tbiwigh  much  iiuire  uuniei»ut  nml  !■'  _ 
vidually  larger  in  the  i.i.T\-ii.Ml  aiul  liinil>areiiliirgeinenu  than  in  ilif  ili>v»^ 
regKMi,  We  may  lurtliur,  uith  greati.T  or  lev  nmcoau.  diviilu  ihviii  ">'" 
teparale  grutipa. 


m 


THE    STRCCTUBE    OF    THE    SPINAL    CORD.  683 

FlO.  ITfi. 


CEKIKMI.   NKMVE.      ll^llh:i!HlM.IlPN,i 

This  If  drswn  on  (he  unine  'cHit  n^  Fli;.  17),  ilml  i-  iiinBriilliii  lin.i'n  liiiu'i'.  r./.  I..  liiliTal  rfliriiliir 
'imatlon  -,r/.p,,  ptwleriiir  reilciilHr  fiiriii^itliiri ;  ji',  liiw  iihivs  •>i'  laiiral  liiimlk-'pf  !)»■  iNi.itri.pr  ri«.i  : 
'.p'^,  fibres  ormefLlan  bundkporiri)giori4»rnH»l  i-iiterjii^'  LTny  iiintlvr  frjpin  I'Tticriiiil  i-nsit-riort'oluiini : 

gr^y  matter  of  pi«lerEor  hum  ;  .^;j,'i.,  l>iLi]i1]4.'«nrhNr4.'s  U'li'M^lh^  tip  Ihu  ^|<ii)iil  tim'<-s-'ry  inTxt- :  in 
W  laUiBl  rettcular  formalinii  thvv  arf  "ifii  Mil  IniTi'it-r-ily  ;  I,,  i-  a  miiiiml  -f|iiimi  ••(  [ijiuii-i'tln- 
■sue  mmrklng  out  the  rerebtllftr  inifi  ('.  T  rn.iii  ihi-  (■r.L--i.1  |i;-niiii!iinl  ihtii  i:.  1',  T. :  ;.  -..  /i.ii« 
WD^on;  2  T  ,  ,},  y^  iBteral  <^tr]]«  "f  llie  iiiittTl'ir  ikpni :  r),  cf-Ll-  in  Tlit  rt-L'Upii  ipt  Ehi;  liiii^rHl  celi*  iilrir 
pfniBtlon.    The  other  letter"  of  re(Vftii''o  i\ri  Uk-  i^piiipij  ii'>  in  Kil'.  171. 


684  THE    SPIXAL   COBD. 

Ill  the  cervical  and  lumbar  regions  a  fairly  distinct  group  of  celts  la  seen 
lying  on  the  median  side  of  the  gray  matter  close  to  the  anterior  coluniB 
(Figs.  176,  177,  1).  This  may  be  calfed  Ihe  median  group.  It  appears  alsx 
in  the  thoracic  region  (Fig.  174,  1)  ;  iudeed.  the  question  arises  whether  sU 
the  celU  of  the  anterior  horn  in  this  region  do  not  belong  to  this  group.  The 
other  cells  so  conspicuous  in  the  hirabar  and  cervical  enlargements,  and  ihire- 
fore  probably  in  some  way  associated  with  the  limbs,  may  be  spoken  of  m 
forming  altogether  a  latent/  i/roitp ;  but  we  may.  though  with  some  uacer- 
t:(inty  subdivide  them  into  two  or  three  groups.  Thus  in  the  lumbar  regiim 
a  group  of  cells  (Fig.  177.  2;)  lying  near  the  lateral  margin  of  the  more 
dorsal  part  or  base  of  the  horn  may  be  distinguished,  as  a  lateral  nub-^roup, 
from  the  cells  occupying  the  ventral  lateral  corner  of  the  horn  and  forraing 
a  vriilrnl  or  iinterior  siib-yroiip  (Fig.  177,  2");  and  the  same  distinction. 
though  with  less  success,  may  be  made  in  the  cervical  region  (Fig.  176). 
Further,  we  may  perhaps  in  lioth  regions  distinguish  a  group  of  cells  ploced 
more  in  the  very  middle  of  the  horn  aaa  central  etib-ifroup  (Figs.  176,  ITT. 
'2  ,J).  But,  in  all  cases,  the  separation  of  these  cells,  whicn  we  have  spokea 
of  a^  a  whole  as  lateral  cells,  into  minor  groups,  is  far  less  distinct  than  the 
separation  of  the  median  group  from  these  lateral  cells,  especially  if  't 
admit  that  in  the  thoracic  region  the  median  group  is  alone  clearly  repn- 
sented. 

In  the  thoracic  region  a  group  of  rather  smaller  cells  is  seen  at  the  hue 
of  the  anterior  horu,  near  to  the  junction  with  the  isthmus  (Fig.  IT-l.J)- 
In  the  cervical  and  lumbar  region  these  cells  are  very  scanty  (Figs.  176, 
177.  7). 

The  relU  of  the  posterior  tioni  contrast  strongly  with  those  of  the  anterior 
horn  in  being  few,  and  for  the  moat  part  small.     They  are  branched ;  snd 
though  we  have  reason  to  believe  that,  like  the  cells  of  the  anterior  hon, 
they  possess  each  an  axis-cylinder  process,  this  is  not  easily  determined  by 
actual  observation;  the  processes  do  not  run  out  to  join  the  posterior  root, 
as  do  Ihe  corresponding  processes  in  the  anterior  horn,  and  therefore  are  not 
so  readily  seen.     These  cells  occur  in  all  regions  of  the  cord,  and  appear  to 
bo  arranged  in  two  more  groups.     The  lateral  margin  of  the  posterior  hora, 
at  about  the  middle  or  neck  of  the  horn,  is  along  the  whole  length  of  the 
cord,  but  especially  in  the  cervical  region,  much  broken  up  by  bundles  of 
fibre.''  passing  in  various  directions  and  forming  an  open  network,  called  the 
I'tti-m/  retieit/ar  fonnatimi  (Figs.  176,  177,  r.f.  (at.).-    In  all  regions  of  the 
cord  a  number  of  cells  are  found  associated  with  this  reticular  fbrmation, 
forming  the  group  oj  the  lateral  reticular  formation  (Figs.  176,  177,  5|.    In 
all   regions  of  the  cord,  also,  a  group  of  cells  (Figs.  174,  176,  177,  H)  k 
fliund   in  that   [wrt  of  the  horn  where,  a  little  ventral  to  the  substaoceof 
Rolando,  the  uniform  field  of  gray  matter  is  broken  up  into  a  kind  of  net- 
work by  a  number  of  bundles  of  white  fibres  running  in  various  directinn*. 
This  network  hu.-*  also  l>een  called  a  reticular  formation,  and  has  received 
the  name  nf  poalerior  reticular  formation  (Figs.   176,177,  r.  f.  p.)  to  dn- 
tintruish  it  from  the  lateral  reticular  formation  just  mentioned;  the  t«o. 
however,  in  some  re^itms  (_see  Fig.  174)  join  each  other,  and  thus  cut  off  > 
vcDiral  portion  of  llie  iw»terior  horn  containing  nerve-cells  from  a  doww 
poniim.  .r  in  Figs.  17(3,  177,  in  which  no  obvious  or  conspicuous  nervcHrelli 
arc  preseiK. 

The  grouja  of  cells  jusi  mentioned,  with  the  restrictions  and  modificalio^ 
S|jokeu  of,  occur  along  t!ie  whole  length  of  the  cord  ;  but  the  group  of  cdll 
to  which  we  must  now  call  attention  is  almost  confined  to  a  special  region  oi 
till'  curd,  or  at  least  is  hut  feebly  represented  elsewhere.  In  the  tnoiMW 
rc;riiin,  csjiecially  In  the  lower  thoracic  region  (we  shall  return  to  the  lim't* 


W  groub  lilcr  on),  at  llii;  bn*e  o(  t\to  iK^terinr  horu  (Fig.  174.  S).  jitet 
|bl  lo  tlw  curve  rurnivd  by  llio  |K^tvrii>r  tfrny  conimbeure  tm  iliis  btiiils 


B-vuiniii.  SKTioii  or  nil  snuAi.  comi  iBnui)  «i  tbr  Lmi.  or  tuc  Tiiir» 

I  inUie  wDw  Kvleurip.  ITI,  ITl,  kiiil  in  iM  «in«  njr.  rimpt  Unl  Ike  oiKlto*  ol 
rM  Doi  runcnird,    If.  mdlui :  rr.  IMCfBtiUMe ;  IV.  latanl  bia>d>«  «<  tmoto' 
nn  niQi|iili>J  mdft  ■.!.  t>  tb*  kmvImI  •oO  or  Umbimi'i  mm.    TteMhcr  IMlai* 
I  »•  Ik*  MB*  M  in  nSK  1:4.  ini.   The  iktt*  •gunv.  i;«.  IM.  177.  an  InMwfad  lo  ItlWBU* 
{■dlAraiiUkl  ••urn*  of  itectfiloBl.  ilKinwk.  aad  lumliK  conL 

|Ijr  to  joiD  tli«  p(W«rior  bnra,  b  ■*«»  011  neh  tide  o(  rbe  mrd  a  con- 
(oi  groap  of  rcllt>  kliiiwn  lU  t'/nrit't  roJumn,  or  lli«  porirrinr  rt-fiailar 
jjn  or  vfrimhr  rytiiidtr.  TUc  celU  cuimiotiiig  ibu  group,  tliougb  vary- 
uie  •!  diffli^rciit  Icvvl*.  are  rnihar  lnrg«  c«lU,  nnJ  nra  for  tli«  oxat 


666 


THE    SI'INAL   CORD. 


[Ktrt  (uBiform.  irilli  tbejr  loiifr  uxi«  ]>1it«xt  leD);tbwBys  hIoiik  rliv 
(bat  in  iranEri.'rM)  sectiuu*  thvy  olti^ti  n|iiN.-«ir  to  have  a  ralli«r  «inall 
body.     Tbc.varc  sDrrouixIctl  by.  Hnd  as  il  were  iinbeild«<l  iu,  n  nuMif  fai 
fibres,  the  mv&  of  which  is  itii)i«it«d  by  a  dott«d  line  in  Fij*.  174. 

Abo  coiispicuoiJB  in  th«  thorade  n^^ron  ia  ai]Oth«r  KToup  of  c«lls  liiiij  m 
tJie  outer  Mde  ot'  ih«  middle  of  tb«  gny  nialt«r  st  abutit  ihe  junction  iif  lU 
Ulterior  and  pneterior  boras,  l^liia  is  Known  as  the  intermtitia-Oaer^  trta. 
and  issomednies  called  the  lateral  horn  (Ki^-  174,  4).  The  oelb comiwoi 
it  are  loinewhat  small  Fpiodle-Bbaped  i.'ells  »'iib  tbeir  Ions  &%»  [lUuij  iniu 
rertel}'.  The  iiroup  is  couapicuous,  as  we  hKve  Mud.  in  the  tboncir  ncpnia. 
it  may  be  reco^iiixed  id  the  lumbar  reiiioii  ( Fig-  1T<>.  4  >,  bul  tn  tbv  nnitti 
ngion  becoinea  (Mkufused  irilh  tlie  mutt  <lor»atly  placed  or  Utefnl  (iil>-gr«ij> 
of  the  iuiieri»r  hum.  We  shall,  bomever.  have  to  roiiim  tn  tbts*  gMup  4 
0(11*  when  w«  ooine  tu  apeak  of  the  difl^mnctt  becweco  tl>e  atvonl  k(mii> 
of  the  wnl. 

S  568.  The  tract*  of  u^hite  matter.  At  flnt  flight  tha  irhiu>  matter  ft  ib 
cord  nppcan  to  be  «f  unifunii  nalun:.  We  can  umi  the  oerve  rooti  u  dt- 
limitate  the  antt^rior,  pooteriiir,  and  lateral  columns,  bul  we  appear  lo  hm 
no  crilcrin  lo  diftinguixb  jmrts  in  each  o»Iumn.  In  the  cemcat  and  u)i{*r 
tboncic  regions  of  the  curd,  a  septum  ( Fig.  174,  <>.)  in  tlie  poeterior  oiltimD. 
somewhat  mon-  cotitpicuoux  than  the  other  H^jilti,  has  enabled  anatMniia  h 
dislingtii^h  an  innc^r  median  iKirCi'ui.  iho  au-tiuin  potlerior  toluuin,  couhdobIt 
called  the  ponlrro-mrdi'iii  column  or  tvluma  of  ffoll  (Fig.  174,  m.  p.i,{Ka 
an  outer  lateral  portion,  the  •■j-irntal  jtoettrior  rolumtK,  eoinutonly  called  ik 
poflero-extwnat  eotumii  or  coluiati  of  Burdaeh  (Fi^,  174,  «. /i.  r,  the  luml 

Ert  of  which,  nearer  the  gray  mnltcr,  has,  for  reaooos  which  ire  ihaB  n 
er  on.  been  called  the  pimtrriar  ronl-iting.  liut  beyond  tlib  ndlhtr  tb* 
irrej(uUr  septa  nor  other  features  will  enable  us  to  dislinffuisb  one  {mr  of 
the  white  matter  as  diflereut  in  nature  from  another.  Nor  have  wc  hiu«t 
lucow  when  with  the  ^cal|]el  we  attempt  to  unravel  otit  the  irhito  ouUer 
into  ■b])arut«  strandi.  Neverlhelesa  we  haire  oouvincuig  evidence  tliat  tbt 
whiM  matter  i»  arrmg^ed  in  atranda,  or  traote,  or  columns,  which  havs  Af- 
ferent connections  at  their  reii>ecttv«  ends,  wbidi  behavo  difierDDtly  uidfT 
ditforent  drcunislaiicu*.  which  wc  have  every  reason  to  believe  carry  od 
diflereot  functions,  but  which  catiiiut  be  seiiimtod  by  the  m^alpcl,  bectUK 
each  of  them  is  more  or  Ins  mixeil  with  bbret  of  a  ditronni  nature  mi! 
orifln,    The  e^Hdence  for  the  exbtcnco  of  Uiom  iracta  is  twofold. 

On«  kind  of  evidence  i*  embr^ological  iu  nature.  When  a  nerve  Abn  it 
b«ng  Ibrmcil  in  the  ombryu.  either  in  the  spinal  cord  or  elsewhere,  ibt 
eawiitial  axisc  ylinder  is  f<>niie<l  lint  and  the  l«n  caamtial  medulla  u  furtntA  ' 
later.  Now  when  the  devolupntenlal  history  of  the  spinal  oord  is  sludieil  it  \ 
is  found  that,  in  the  Mveral  regions  of  thi^  con),  all  the  fibres  of  the  ahiir  ! 
matter  do  not  put  on  the  mcilulla  at  the  same  lime.  On  the  contrary,  tn^ 
oeriain  imcts,  the  medulla  of  the  librcs  makes  its  appeanince  early.  In  otMr* 
later.  Uy  this  method  it  bcoomes  pomihle  lo  diatinjcuiah  certain  tracts  frota 
others. 

Another  kiud  of  evidence  is  supplied  by  facts  relatins  to  the  degonerati< 
of  the  fibres  uf  the  while  matter.     We  have  seen  (§  dS'Ji  that  the  ddgctwn' 
tioD  of  a  nerve  fibre  is  the  result  of  the  separation  of  the  fibre  Irani  v 
trophic  centre,  and  that  while  the  trophic  centre  of  the  afferent  fibraa 
ihv  tfauglioD  oil  the  posterior  mot,  that  of  the  ellWent  fibre*  is  in  aome  , 
of  tlio  spinal  cord.     In  the  ease  of  the  eflereni  libn^  the  di^vneral 
might  be  spoken  of  aa  rfssMnrfm^  from  the  apinal  cord  to  the  muscle*  n 
other  iwripheral  orgiuts.     In  the  caxcr  of  the  alTcreiit  filin*:!  uf  tbo  trunk  i 
the  nerve,  llic  degeneratiuu  i«  ahtu  one  deacetiding  fruui  the  ganglion  dua' 


glion  dua-^ 


TIIE   STRL'CTL'RB    OF    THE   SPINAL   COKO. 


6a7 


I  aktn  or  oth«r  peripheral  organ.    When,  bowcvor,  tho  mcUaii  U  enmod 
tg\»   lUi>   {MMvriiir   TiHiI   iif  II  npitm)   »«rv(>,  ihr  ilc^ni'ntlinii   titkis  [ilitM 

Cn  Iff  iltf  ncirTi*  botUL'i-n  the  xtH'tiDii  mid  l)ie  sjtiiuil  coni,  it  ruiw  uj) 
MvliuD  to  nnil  iul"  tin?  njiiunl  conl,  ninl  iniiy,  tliertrDrr.  lie  rnllM 
vernding  tlegeDCTBtioii.  Tliuit  viii  may  Miy  tlinl  ulir'n  n  nrrvr  trunk  or 
b«a  m  tifvtv  root  m  cut  iijitipMely  ihtpm,  nil  thti  lilinw,  which  arc  (herebj- 
pMrminl  ("mm  iliWr  tmphic  wiitr<»,  <Ii'grniT»t«.  When  lh»  oervr  trunk  is 
livitlnl.  nil  the  (ibrm  \tVtv  lh«  M-i:li<>ii  iimlcrgo  dacvnding  degeneration. 
tbt  anit'rior  root  hi.-  nit  Koriuw.  nil  tho  fibril  i^f  tho  r-iot  b<-law  iho  Kctioti 
(Incrndiii^  'li-)Kii«mtiou.  It'  iho  jKwlcHor  mol  be  t-iit  iicioae,  iill 
fibra  of  (Im:  root  bIrivv  the  M-eiion  undi'rgn  ascenditig  dc^nermtion  with 
«xc»]ilio(i  of  4wrt«ia  fibres  irhii^h  do  not  dogenorBte  at  ull,  nod  of  wbioh 
r  thall  »i>ctik  Inter  oo.  • 

Wba-ii  i)i«  *|>tiinl  i-ord  is  cut  oerow,  for  iiwlnnoe  in  lh«  dorsal  rvf^on,  nil 
le  libn»  of  the  uhite  matter  do  not  degeiierau  ^iher  in  liip  {Mrt  of  the 
'  above  tho  section  or  in  tho  part  below.     Some  flbtvf,  and  indeed  some 
_..  of  fibres  degenerate,  and  some  da  not.     Puriber.  Bonie  tracts  defren- 
hnUe  ill  the  cord  above  the  eeclion,  and  thus  under^i  what  has  been  called 
••ceudio^  dejfeneratioD :  other  tracts  def^nenilc  in  tlie  eunl  below  the 
n.  and  ihu^  uDder)|:u  what  has  been  called  a  deacendioi;  de^'eneraliou. 
term^  luust,  hunever,  be  used  with  caution.     When  a  nerve  trunk  in 
i  Bcrote.  the  dc^nerattuii  actually  defloeotb,  in  the  sense  thai  the  progress 
tb*  deeeoeraiive  ehnu^eti  tim)'  be  traced  downward;  they  beKiu  at  the 
.ioo  aiia  travel  downuiml  at  a  rate  sullidently  tlow  to  permit  u  diBerenoa 
ing  obwrvet)  l>^twe>eu  the  progress  of  degeuenition  at  a  M{>ut  near  the  seo- 
ftod  that  of  one  farther  tm.    Atler*ccii<mof  or  tujurjr  to  the  spinal  cord, 
<<r«Ttr.  it  U  Dol  pntnbte  l»  Inice  any  sur\t  ]>ro^;reas  either  upward  ur  <Iown- 
ard:  iu  the  tnici>  both  above  and  lii^low  the  nection  or  iiijurv,  degenera- 
ioD  cither  iMrgins  «imultAiieou«ly  along  the  whole  length  af  the  (It^Drrntiiig 
tract,  or  projimw*  along  the  tract  w>  rapidly  that  no  diflervucns  can  be 
cd,  as  Inr  as  the  singe  of  di^grnermiion  is  concerned,  bclwee-n  |>art«  near 
tbi«e  far  from  the  section  and  injurr.     When,  for  instance,  tho  cord 
ivided  in  the  ocrvioal  rq;ioii,  subsequent  examination  uf  tlie  trmcls  of 

Ecalltd  dcaoendiug  degenerattoii  show's  that  tho  (^generation  is  as  fiir 
rauced  in  the  lumbar  re«pou  far  away  from  the  soction  as  in  the  cervical 
[ion  just  Iwlow  the  section.  Applied  to  the  spinal  oord,  therefore,  the 
rm  detc'endiiig  dt^neratioa  menu*  simply  degeneration  below  the  seat  of 
jurv  or  disease,  nseeDding  degeiation  means  sioiply  dtgeneiation  above  the 
of  injury  or  disrate.  We  way  add  that  tJie  nisLoIogjcal  fealtiree  uf  the 
ion  iii  tibrce  in  the  spinal  cord  are  noi  wbollv  identical  uitb  those 
the  deceDeraliou  of  fibres  in  a  tierre  trunk.  Thus,  the  neurilemma  with 
nuclei  oeinc  absent  from  ilie  libra  of  the  curd,  no  pruliferatiun  of  nuclei 

Enlaee ;  tbe  axis-cylinder  and  nteduUa  simply  break  up,  are  nb^rbed, 
d  (iMppear. 
Similar  defceueratioDs,  asceiiilin);  or  deaoemliu};.  or  both,  are  neen  wheu 
taectka  i>  not  carri«<l  right  through  the  whole  cord,  but  partimilnr  iwrta 
the  i>>rd  are  eut  through  or  deeply  injured.  .Knd  similar  degeueratioiu 
feccur  a»  the  c»n«et|iiencea  of  d!i«iut)  net  up  in  partn  of  the  cord. 
I  In  ihi*  wav  the  runulta  of  Mctions  of  or  of  other  iiijurie*  to  or  of  diseases 
tf  the  aptnar  cvn),  have  enabled  us  to  mark  out  certain  tractn  of  iIm;  white 
■alter  as  undergoing  degeneration  and  others  aa  not.  and.  iiiorMiver  iMrliun 
(nu'la  a*  umlergoing  duncciiding  and  othcni  aji  un<lcrgoing  ascenduig  d<^D- 
ntion.  Kiirtjier,  the  delimitation  of  tracts  of  while  matter  by  llie  inocns 
if  degeneration  agroai  so  wnll  with  the  mult*  uf  llie  embrt'olitgicol  method 


mci,  o 


L 


688 


THE    Srl.XAL   COKIf. 


m  to  IcATo  no  doubt  ihnt  (he  white  nislt^rdoescomiAt  of  tntcU  wbka 
(Void  mcli  <Abtr  in  uature  an<l  in  function.  

TIm  Hcvt^nil  iracl*  iliiii  itniimicO  vnrv  in  diflmDt  regnoa  of  ibt  conL 
Tboy  auiy  Ix^  t)^!^!!}'  ilcMi-ritieil  a^  t<>ll«w9; 

I.  HtK'tt'iing  trafi*,  lliat  is  t<t  uty,  trai-tB  which  uiHlergD  &  dMcendiBf 
drgi'iicrittioi)  in  tliu  »on«u  nolcd  nliovr, 

Th«i  nitwt  ini)H)rt«nl  mn<l  cuiuiiicuouii  U  ii  Urge  met  (,Vig.  liR,  cr.I'i 
oi'ciipyini;  the  ]Kmlcrior  i«art  of  ihe  JAifrnl  column,  ci>Kiiu|i  cl'--    ■'- "  '•- 
oiiltr  timrgiii  of  th«  pixtitrior  born,  iiixl  for  tltv  mutt  |iart  ugt 
surfiii-c  of  the  (»>ixl.     Wo  oluill  htivc  lo  rrliirn  to  thi«  lni<-t  miir<  >>>. 
mul  ramy  horc  simplv  »r  thnt  it  Is  nioNt  <li»tini;ily  tnarki-tl  out  Iit  I> 
enibryulot^it-at  und  tlie  drgvntnilion  mvlh'xlv,  (liiit  it  ai»y  he  Irnnii  \ 
Ibc  whole  length  of  the  cord  from  thr  top  of  tW  i.'crvionl  region  l<i  ih-  <  1 1 
of  Ihe  wicriil  rcuion,  nnd  ihnt  it  cntpn  the  rortl  from  tbu  bniin  ihnmt:><  li" 
structures  called  ibo  pyramids  '>f  the  Iviilh,  uhirh  w  nbntl  fliidt  \uu  t    : 
TImbs  pyramids  crws  over  or  decui««te  as  tln-y  nn-  nlnmt  to  ]in«*>  r 
card,  forming;  what  is  known  as  ih«  dtn'uamion  of  ihv  nyrainid-  n 
tract  of  6bre*  in  tjueslion  abBres  in  this  decusmioii.     H< 
cnlled  t\M  en4»ed pyratnidal  tract  or  mar«  ftiiopl}'  the  j'yrHxo 

no.  17*. 


IK 


t.a,l 


PiAiMAiiTa  ti.u-niiATK  TiiattRNuji.  AmuMinuMTo^THt  3«mtAi.  Tiut-n  09  WHire  Ht 
If  ru*  ft'iKii.  CiMn,   iMiukiKDraN,) 

TbeimUiililtUlranMUH'WTcliirilicnnhr'tmfBlutiTv.    Tti*  nUllunt  nC  tlH>  ttMW  *>  itll 
nglOM  at  lb«  iM«<l  KM  *n<nra  In  r<i|.  IW. 

Tha  MandlnK  tmdK.lniMi  ur  itw>-i»ini(  dtcMMnUuii.  ■/»  tluJHl  wUli  iIih*,  II«  i 
tmol>.tncUofdeinD<llii(4tKvn*nik>i>.Mv>b*dtrt  Willi  IIrm;  liindwiillair  InMClinwvw^ 
ildauf  tliScORl.  viilj^ltia  tvDnimlDlMfthMliK  |4i(0nl»»  1  hr  iitlior  tl-l«. 

cr.l'  c»f  Ld  ifTnmiiW  mil.  "t  mm  nbuilj.  i>rrurliliil  ir*n  iLr.  iIlriKi  pMsmlM  '>*'*> 
ikiul«<l  oil  tliu  ilitr  u|i|->d4t  to  lh«l  on  Wtltrb  rtP.  k  iliMlnl,  iu  ontef  t<'  ln>!li«lo  tto  dUMwNi  •( 
ilin  t<K>  *>  (r.  >.mnlDg:  c.h,  cvnbplUr  mil ;  t.lr.  ■»<)  «r.  iiffiiipi  ■■■■■>niii>  iIm- mtdlan  p^"" 
Imrl  orinclof  nlim  ol  the  poMtflnc  (iwls  VI,  rriimmlUiR.  «•  liei|>:<  ^.illjr ID IM ML 

lliBt<nlc*)*o4*.lr,  UtcMeral.  IwiBlwr.  kixl  iIo*mI  nioit:  aic.it.l.  !>>•■'  :  •■■nni»iitti*- 

■Jewl.  ilionuttioliietmitw^-"  ''-  ^  ■  — ■■    r-,- -,•—.,  cwialMitHl,  nwrki 
inii-ioi  nilipc  |i*ti'ii  mcniiiiii  .-  iin  oxMln  ndm 

|ii>lcnuiou]<i>aii  r*     'ri<v«ii<.  I        '  Ik  ixaWHoT  liiini.  ■"' 

final  Miia  of  LlaHstr**  H>Me. 

A  (Diiillor,  lew  <'<'n>piriuiUH  dmcMxIinff  irscl  ori'iipit'ii  tlu-  iDi'dinn  nani'* 
at  tb«  nntcriDr  ii>himn  (Fig.  17^,  d.P.  Thin  i*  nul  only  much  Mimltcr  hM 
alto  nuch  more  vHrinblo  than  iIm-  rnwwd  pymmiilul  tnict,  in  not  prnwiin 
lk4!  lo««r  wiinialti.  being  found  in  mun  nnd  the  moiikvy  only  and  U'ltii.'  *''"^ 
devvlopi>d  In  man  thap  in  tlie  monkey,  and  nwclKS  ■  n-rtjitn  way  ocl'  ' 
ikc  spinal  cord,  generally  coming  to  an  «iid  in  thi>  thoracic  n-)(tiiii. 


THE  itTBCCTCRB  OF  THE  SPINAL  COBD. 


m 


fViini  tlic  prntmiil,  and  it  b  contiiiuntiuii  af  Unit  part  of  the 
ioh,  unlikf  l}i«  n»t,  thxt  not  dcctiatittc  in  lh«  bull);  thiM  the 
tract  which  i-omiiiK  dimii  from  tho  li-ft  dkIo  of  lh«  lirnin  nms  in  tlw  left 
pyrantid  iti  the  hufb,  [himmv*  <1owh  iiiin  elic  It-ft  fliiierior  coliimti  of  the  oonl, 
ilsnce  thi*  Ninitlli-r  inict  i»  wiUcil  the  liirrrt  f,i/i\imi<ial  tract. 

Thvm  tiro  titK  iliv  most  conKjiiciioiiR  nn<l  imjiortAiit  (lw>ccti(liog  tntcta,  but 
DtinK-R  hnvr  Ih-cd  j;ivci)  to  two  otbrr  ijcsccniling  trnclH.  Oii«,  known  aa  tlie 
anlfi-o-latifttl  dof^niling  Irarl,  is  fl  l>rco  Iruct  |>l)icc(l  iu  the  nnlero-lHteral 
eolumii,  nml  (eeo  in  scctKiti  <Fig.  178.  cicec.  t.)  w  an  elongated  aren  Mr^tcb- 
ig  fnini  ihc:  {ivraniidal  Inict  lowanl  ih«  anterior  column  and  reaching  at 
ilOM  M  f»T  as  the  anterior  lisiure.  The  area  i*  lar^,  however,  because  the 
IB  very  diiritse,  that  is  to  t*y,  the  librm  witli  descending  deg«neralii>ii. 
fibree  which  dq^enerate  below  the  se«:lii>n  or  injury,  are  very  l«r;,t-ly 
ixe<l  up  with  libre^  which  do  nut  degenerate;  iu  this  respect  ihia  tract  con- 
tnau  with  ibe  pyramidal  tract,  whicb  is  to  a  much  j;r«nler  eslent  compuaed 
frf  fibres  with  descending  il^^generalion,  though  even  in  it  there  are  a  coutiid«r- 
ble  number  of  tlbtcd  which  do  nut  degenerate.  Indeed,  tb>a  tuilero- lateral 
deacending  tract  a  ao  diflW  tJiat  it  hardiv  deaerveo  to  be  called  a  tract. 

The  other  ia  a  ainall,  namiw, comma itbaped  tract  (Fig.  178,  x),  iiitnntcd 
In  the  middle  of  tlw  external  pi>st«ri<>r  culuran  nhich  bus  been  oWrvcd  in 
the  cervical  aii<l  upper  thoracic  region*,  and  ha«  been  called  the  "  dtMcnd- 
Ins  ciinima  tract."  But  the  dt^jeueration  iea«he«  a  short  way  only  below 
|h«  aectioii  or  injury  oikI  the  group  of  fibrM  iIiuk  degeix- rating  can'  Itnrdly 
COUildiTvil  as  funning;  u  tract  <!omparablc  to  llic  other  (mc[«.  Th«  ar«a 
probably  n-nn-Hcnl.-^  tibn-«  of  the  poetcrior  root  which  take  a  <lftceiniing  c^iurtc 
nl\<'r  itii'ir  <-ntriiniy  iiilo  the  conl. 

Atcrntiing  irafit,  that  iit  t<i  wiy,  tracts  in  which  the  dogetMration  talcM 
_    aboro  the  («ction  or  injury. 

A  eompicuoiis  uocnding  tract  iif  a  curvtil  »1inp<- 1  Fig.  178,  C.  b.'i  »ccu- 
iat  liw  oaivr  donal  part  of  the  bitrral  i\>luiiiii  lying  lo  lliv  oul>ide  of  [be 
~  |»nuuidal  tract,  between  it  on>l  the  surface  of  tho  cord.  It  iipncars 
b«gin  III  ths  up])er  lumbar  rvgion.  being  said  to  be  alMenl  from  the  lower 
lumber  and  Mcral  cord,  and  tnay  be  traced  upward  incrrasing  in  size  through 
'  e  thoracic  and  cervical  oorti  to  the  bulb.  In  the  bulb  it  may  bo  traced 
to  the  reelitorm  body  or  inferior  peduncle  of  the  ceivbelluni,  and  so  lo  lite 
rebellum ;  for  the  reatiform  body  wrves,  as  we  ahall  tee,  in  each  lateral 
lalf  of  the  brain,  aa  the  main  conitection  of  the  cerebellum  with  the  bulb 
nd  spinal  cord.     Hence  this  tract  is  called  the  crrelrrHur  Irati. 

A  »ec<^ind  important  asc*.-ndiuK  tract  occupies  the  median  portion  of  llie 
DHterior  (xiluronD  (Fig.  178,  i-r,,  s.lr.),  and  »o  far  coincides  with  what  we 
eKnl>ed  al>ove  ao  tlie  median  posterior  column,  in  tlve  upper  rejfions  of  the 
ord.  that  it  may  he  ualled  the  umiian  fituttrior  Inift;  it  extends  along  tlie 
■hole  length  of  tl>e  spinal  cord,  varying  at  dilterent  levels  in  a  manner 
ibich  ne  rihall  prtMnlly  studv.  and  ending  alK>ve  in  tJie  l>ulb. 

A  ihinl  iiM-vndintF  tract,  called  the  wu^nuUn-j  antero-AtbrirV  Inicl,  or  tract  of 
)ower«,  occupii-n  I  Fig.  17H,  aac.  a.  1.)  the  outer  ventral  part  uf  the  lateral 
nlumn.  It  ban  tnmcwhal  the  form  of  a  comma,  with  the  Iw^ul  tilling  up  thf 
le  left  liMwceu  pniji-^'tint;  porliotin  of  (he  eerabdlar  and  pyramidal  tracts, 
tJ>e  tail  stretching  anay  vctitriilly  along  lite  outer  margin  of  the  lateral 
slumn  fHilaido  the  ani<'rO'liitcriil  1 1 ivcit tiding  column,  tho  end  of  tl>e  tail  otlen 
iching  to  ibo  anterior  VKfi*.  It  niuy  hv  traced  iLli>ng  Ibu  whole  length  of 
eonl.  bnt  it  m  itot  eo  dii>iinct  and  c^iinpact  a  Iract  ■■  iIk  two  aiioeudiug 
jcts  juat  mentioned  ;  the  Ahmt  with  a^riuding  di.'gNMration,  that  is  to  oav, 
.e  fibres  degenerating  above  the  section  or  sent  of  injury,  are  vvcy  largely 
lixed  with  fibres  of  a  dillerent  nature  and  origin. 

41 


090 


TRG   EPINAL  OORIt. 


ing  inti 

nwU,  li^l 
Urtnn. 


Wo  ta\j  Atrth«r  reniftrk  tliiit  Ibcsc  Mveral  tncts  differ  (com  eaeli  «i. 
in  como  corns  mtrkoiJIjr,  as  to  the  dismelcr  of  their  coostitueul  flbra.   Thi 
the  cowbcUiir  Irncl  is  compoeetl  aimom  (exclusively  of  reoiarknblj  e    _ 
fibres.    The  median  posterior  tract,  on  the  conlran-.  is  wade  upof  ffaefibm 
of  very  mjuable  sixe,  while  the  fibres  of  the  antenv-lnleral  ssoeadiuft  mtl 
are  of  »  sue  iuleni)e<iiate  beriteeo  ihe  other  two.     The  jiyrauidal  ir 
the  Other  band,  is  mnde  up  of  libre^  of  almost  all  nua  mixed  together. 

The  tracts  then  uhich  an?  thua  marked  out  are.  aa  deeceoding  iraoU, 
CioiBiid  aitd  the  direct  pyrftiuiditl  tracts,  with  the  len  diatiiiclorim, 
nulera-Ialeral  dwcendiog  tract :  and.a^u^oeiidin^  tracU,  the  (jenbclUir traM. 
the  median  poaterior  tract,  and  the  les^  diittiiict  ai)ten>-laleral  uoat&og 
Iract.    If  we  iiu|>pose  all  these  truels  taken  uniiy  theiv  i»  Mill  leA  a  raiitiilK- 
abli;  area  nf  white  matter,  uamdv,  uearlr  the  whole  uf  the  external  {xaleni* 
rolumn,  the  t.xlcrnal  anterivr  coluiim,  iucluiliiif;  the  rt^on  trmTeraed  bv  tbt 
bundles  of  tbi;  anterior  rMi^  and  that  |iurt  of  the  lateral  column  wlucli  Ija 
between  the  ant(ro-latcral  di'Wfndin);  tract  iind  tli<^  crww-d  pyramidal  tns 
on  the  r>iit»ide  and  the  gray  matter  im  iho  iuitidi:.     From  thi»  am  of  vUk 
matter  wc  mar  Dut  on  one  side  tit  prvMvnl  the  cxtental  poetcrior  eoluao 
because,  ««  wo  shall  see,  thU  cvlunin  i»  largely  compOMid  of  the  Gbra  rf 
the  poaterior  root  which  pasa  through  this  column,  especially  through  ik 
lateral  part  of  it  near  the  gray  matter,  on  their  nay  to  tlrair  ultimate  dtni- 
nation ;  hence  the  alternative  name  of  posterior  root-ione.     We  may  liuc- 
larly  leave  for  the  present  the  small  zone  of  white  matter  cumpused  of  veri 
fine  fibres  known  as  l/it  po»lfrior  maryiHol  fonr  or  Liaaucr's  £une  |'Ki|(.  IT?. 
1^)1  l/ing  dorsal  to  the  tip  of  the  posterior  horn  and  in  the  lower  reguei 
reocfaing  to  the  outside  of  the  cord  ;  fur  this,  too,  belongs  to  the  fibres  u  tbt 
posterior  root.     Leavin;;  these  parts  out  of  consideralMHi  we  may  lay  ■• 
roiEardti  the  rmt  of  the  white  miittcr,  that  the  present  Male  of  onr  knowltdn 
will  not  allow  uft  ti)  divide  ii  into  iipeeial  traeta.    All  thi«  area  i*  larnly 
cODipoAcd  of  dhn-f  ivhich  do  not  under^  either  aMendiDK  or  'iMCOnail^ 
di.-gtiiieriiUon  un  the  n-nnll  of  ft'ctinn,  injury,  or  diseate.     It  has  bi-eil  tui~ 
gcslcd  that  ihc^Hj  fibre*  either  htivr  tin  trophic  centre  at  all  or  have  d«ih. 
ones,  one  above  and  one  below,  on  cither  of  which  they  can  in  ciuo  of  iiefj 
lean :  so  that  when  the  fibre  is  ilividod  at  any  level,  the  upjx-r  jwrtion  b 
nDaridied  from  some  centre  shove,  and  the  lower  fr>»m  mme  centre  ' 
A(  all  events,  whether  this  bo  the  tnio  explanation  or  no,  Ihe  fibres  in 
part  of  the  while  matter  cannot  be  diflereniiated  into  Inicts  by  a  study 
llieir  degeneration.     Fibres  of  this  kind,  which  wo  can  apeait  of  neither 
asoeoding  nor  as  descending,  also  oeeur  in  the  cjctemal  pwtertor  column 
rolDgled  with  the  fibres  of  the  posterior  rmit.     And  we  may  repeat  the  au- 
lIod,  that  even  in  the  several  ascending  and  descending  tracts  just  described, 
tapecjally  in  those  which  we  spoke  of  us  leei  distinct  or  as  more  diffuiie.  nnav' 
fibres  are  present  which  under;go  neither  ascending  nor  deecendinK  de^»  ' 
vratiun. 

^  Md.  It  may  be  as  well  ])erhapa  to  insist  here  onoe  mote,  that  when  tlww^ 
several  tracts  or  the  6brei  running  in  the  tracts  are  spoken  of  as  ajicendia 
or  descending,  what  is  meant  b  that  the  degeneration  takes  place  above  t 
section  or  scat  of  injitrj  or  disease  iu  the  one  ease,  and  takes  place  below  i 
the  other.     It  ho*  been  siippnted  by  many  that  the  uervous  impulses  whic 
these  fibres  severally  carry,  travel  in  the  name  direction  tut  that  taken  by  ll::^^ 
degeneration,  that  the  ascej>ditig  tracts  carry  impulmw  from  below  npwu- 
tliat  is  to  tay,  carry  impulses  which  aiiriog  from  peripheral  orgam  pas* 
various  parts  of  the  spinal  cord  or  of  the  brain,  that  tlioy  ore,  in  oilier  wo: 
channels  of  alfcrenl  impulcce.  and  that  convereoly  tlK  dMcendtiig  tracts  cai — "I 
vflereut  impulses.    Tu  this  view  is  often  added  as  a  oofollary,  tnnt  tlie  tr^-^ni 


M 


r  iir—    - 

"J 

Dr«i^ 


TOE  STBUCTI'RB  OF  THE  SPINAL  COBU. 


691 


wbiolt  di>  not  de^eneralu  at  att  cam*  impuliteit  both  «&y»,  and  lience  caiiDot 

•  bo  OMtsidered  aa  eitli<?r  afTun-iit  or  ofTuretit  oliaiiuuU,  but  xiniply  hm  cuiuiiitiui* 
Wtiltg  ohiUlDela.  UpDii  thin  il  may  b<;  rcmarkci)  (hat  imjiMliHitJ  ilu  not  iicccii- 
iinrilv  travel  in  the  aamu  (lircjliinaK  tbe  (U^caeratioii :  wlion  a  xfiinal  nerve 
Iruiik  E*  divided  Ibe  afloreiit  librm  w  vrdl  M  tbe  ctTon-ul  fibril  b'>l)i  di-gcn- 
ttcntn  in  K<lwoendiDgdir«ctii>D  toward  the  periphery,  thuu^h  Ihi!  fontirr  carry 
impnUra  lo  the  othvr  dirvotioii.  Htuicc  ine  dinK^iioii  uf  dvgviif'raiioii  w  nu 
proof  of  the  direction  in  which  impulma  tmvel ;  morcDVur,  m  wo  havo  nocn, 
oegenonUion  doo*  not  mrtmilty  travel  along  the  6\>n%  nf  tlio  i>|>inst  ord  in 
the  Mme  wav  that  it  doe*  along  tho  librM  of  a  norvv  trunk.  It  nmy  bo  thnt 
(h«  dMocoding  tracts  do  carry  impiiUoe  in  n  doer n ding  directi>)ii.  thnt  is. 
efferent  imptiUm,  and  that  the  ascirndiDg  tract*  aorve  lo  carry  afh?r«Dt  im- 
pulse;  but  th«  proof  that  iher  do  thus  respectively  act  must  be  supplied 
from  olher  facta  than  those  of  deji:eneration.     Moreover,  ire  Bhall  have  to 

I  return  to  Iheae  ascending  and  deecendin^  tracts  and  to  Mudy  their  behavior 
alnofc  the  length  of  the  oord  before  we  can  use  the  t'aclB  concerning  them  as 
n  basis  fur  iiny  discuasioo  as  to  their  functions. 
S  570.  The  eonrtetlicHi  of  iht  nervn  rooU.  If  we  regard  tlie  spinal  cord, 
nod  apparently  we  have  riftht  to  do  so,  aareeultiug  from  Ihefuaionof  aseriee 
»r  aegmenlA  or  metaateres,  each  aegmeat,  repreaeated  by  a  pair  of  apioal 
uervee,  being  a  ganK'ionic  ma-«.  that  id  to  aay,  a  ntaas  Dontaining  nerve-cells 
with  which  iien'ti  filirea  are  cuuii«cie<],  ive  ihould  expect  to  find  that  the 
filHW  of  a  spinal  nerve  soon  allcr  entering  in,  or  before  latuiug  from  the 
«piual  cord  arc  eoiineot«d  with  nervfi-cetin  lying  in  the  neighborhood  of  the 
attachitM-nt  of  tbe  nerve  to  the  cord.  We  nhould,  we  suy,  expei;t  to  lind 
tbJR :  but  owing  tu  the  ditKcully  of  tracing  individual  nerve  fibres  through 
the  tJingled  maw  of  the  Rubrtance  of  the  ord,  our  actual  kn<iwledg«  of  ue 
(ermiuaii'in  of  tbe  fibre*  of  the  jKwterior  root,  tuid  origiu  of  the  fibna  of  the 
nutrrior  nml  is  at  pnwnt  far  from  complete. 

Witli  regard  to  the  anUtrior  not,  there  can  bo  no  doubt  that  a  very  large 
pfoporlion  of  the  libr««  in  the  root  are  continuation*  of  the  axi«-cyliuder«  of 

•  cells  in  the  anterior  horn.  The  fibres  which  can  thus  be  traood  are  of  large 
dianteter  and  appear  to  he  chiefiy  if  not  CKclusively  motor  fibrw  f)r  the 
skeletal  muszlee.  In  the  fro^  a  laborious  enumeration  on  the  one  hand  of 
the  number  of  6bree  in  tbe  anterior  roote,  and  on  the  other  hand  of  the 
namber  of  cells  of  (be  anterior  horn  in  the  areas  corresponding  to  the  nerve 
Foota  has,  it  is  true,  shown  a  very  remarkable  agreement  in  number  between 
the  two.  We  raig^it  be  inclinnl  from  this  tu  conclude  that  all  the  fibres  of 
mi  anterior  root  start  directly  from  cells  in  the  anterior  horn,  and  that  all 
the  cells  in  tbe  anterior  horn  end  in  libra  of  the  nearest  anterior  root,  fiut 
tuvernl  ootuideratious  prevent  us  from  truatin^  too  much  to  this  observation, 
mpccially  in  ibe  caae  of  the  higher  animals.  The  anterior  root  contains 
•finer  fihre»  than  motor  fll>r«s  for  the  skeletal  muscles,  vasomotor  fibres  for 
gee,  secretory  Hhrei  and  others;  and  it  is  a  priori  unlikely  that  th«fle 
illd  have  origin  from  the  same  eelb  as  the  nurtor  fibr^  of  the  tikeletal 
niusot<T>.  Mureover,  as  a  matter  of  fact.  Home  of  ilie  fibrw  have  been  traced 
Ihrougb  the  anterior  hum,  on  the  one  band  toward  lli«  posterior  hum  and 
oq  the  other  bund  toaurd  the  lateral  column  ;  otlten  again  are  found  to  poss 
thmtigh  tlte  anterior  horn  of  their  own  side  to  the  bottom  of  the  anterior 
Wurt*  vrh»re,  crowing  over  to  the  other  side  and  thus  forming  part  of  tJie 
■nterior  white  cnmmia>ure,tl)ey  ap}>ear  to  ascend  to  the  anterior  horn  of  tbe 
l.oil)i>r  side.  We  cannot  at  proKent  make  any  pocitire  iiaiement  as  to  the  real 
in  and  exact  naUire  of  tbcec  fibres  which  thuM  upon  entering  the  oord 
._  I  by  the  oolla  in  the  anterior  born  without  joining  them,  though  those 
Uch  cross  by  the  anterior  white  commissure  are  supposed  to  take  origin  in 


i^ 


m 


TBK  SFtNAL  COKD. 


latbcri 


puqi— ■  bi  niMiUr  ibst  «UW  ■  krgt  Dttmber  of  tho  Ttbriv  < 
mat.  yimmilily  tkan  tapfiyiBg  tb«  ckdMil  muH-lrs.  tftl[«  ori^n  in  lU 
ckDb  at  Aa  aaivMr  bnia,  rliannr  itfon  they  iftu«  froin  tho  oir*).  nhm 
Imtc  Piaa  utfcg  aan.    And  similftrl5  we  bxvc  nwK>n  to  think  that  nil  il< 
fldb  ia  tki  KBlenar  BOfa  dnaoCMad  oat  kxi^-cylinder  pmnwee  lflj<  I 
utterior  now  of  dw  aMe  «U«.    W«  mair,  bair«ver,  imrd  a  Urg«  n 
at  all  eraaM  of  tte  cdh  of  the  BBlrrior  bora,  at  the  level  of  af  «> 
Bnleklo*  aad  «  little  ahnvethe  level  of  the  exit  of  uir  pnnictilar  n-- 
root,  tm  cMMitvdof  a  son  nf  iwdcae  of  oti|iD  for  the  Ur^er  niimhri 
ihne,  and  tbeae  nuai  {unbabiy  tke  dteleial  motor  fibn-*.  <>f  that  0:1 
raol. 

TIm  pMlmoT  rwol  eaten  ibe  eonl  not  in  several  bundles  laterally  Kattcrv*! 
m  doea  tbe  aatennr  tmt,  but  ia  a  mora  compRct  inaM.    ThU  ninw,  fanwever, 
eoodfia  n(  at  \tmat  tao  dia(iii«t  bundlf*.  wbich  upon  ibdr  etitnuior  itun  titi- 
mtd,  tBk«  dUKnvM  connn.    One  bumlle,  the  lurner  one,  ^yiog  to  tli 
or  ininiian  ndcof  tba  other,  cnttnallDEul'  rrlntivelr  coaneGbrrA,  aixi  ..;.... 
tJie  McrfMii  immHa  <FIg.  176,  Pr  >,  mum*  ohli(]u<-tr  into  the  litlcral  part  '>r 
ihaextenal  poaiviorooluBB,  ahica,  m««  bav<-  mid.iH  in  mniH-(|uerir' 
nolna  of  aa  iha  poeterior  root-toiM.    Here  iht-  fibm  changing  Uiru 
turn  nin  longitndiiiallr  for  aooM  diataan  upward  (tonio,  bowo^-vr.  vvnsiin' 
in  the  upper  crrri^al  rt^on,  and  probably  in  o(hi>r  regionv,  run  a  ebort  dw- 
UiikcedcnrDwar<lt  bni  evrnliialtr  dttirr  )^l,  ai  we  «hall  m«,  toforai  tbcni<iimn 
poeMrior  tract  or  make  their  way  back  inti  th<;  j^r  matter  at  the  hate  •<( 
the  poaterior  bom  aitd  lhu«  j»4n  lh«  vniciilar  ryhmk-r,  thwigh  some  an;  tt)4 
to  becoutinued  on  throu):h  the  gray  matter  into  the  anterior  horn,    tit 
other  smaller  bundle  placed  to  the  outtide  of  ihe  liimier,  and  called  U« 
tafrrai  bundle  (FlR.  ITS.  Pr^.  niay  be  again  divided  into  an  inlrrmtHiyt 
friirii'/e  (Kic-  17".  IVi  lyinp  next  to  the  median  huiidle,  and  into  a  «till  nioie 
lateral  bundle  (Fij(-  1".  I*r").    The  fornK-r,  (iMidisiing  aleoof  cxtune  ISbrw, 
|dun;;e8  directly  through  the  suhatance  of  Kolnudo  at  the  extremity  uT,  U'l 
ito  tniu  the  ^mv  tnattcr  uf  tlie  horn,  Ttliere  Ibe  fibres  eh an^ ion;  their  directi>'B 
mo  ill  |>art  atleaxi  liinjcitudiuulty  in  the  gray  matter  io  bandlee  kumta  w 
"  tbelungitiidinal  bumlWol'ihi'pwteriur  liuro"  (FiKH.17B,  1 77, r. /.;>.), Me" 
uf  tibidi  Hpimir  to  mm  ou  t»  the  anterior  burn.    The  small  nii«t  axIMiui 
or  lateral  jHirtitiii  »[  ibe  lalernl  buiulle,  consiatinj;  of  fine  fibres  and  MBf- 
tinea  apokeii  of  km  (Ar  liitcnil  liuiulk',  on  entering  (he  ooni  at  udc«  aMend^ 
for  Mime  dinlance,  and  thu»  liinnn  the  ibiii  layer  nf  fine  fihfM,  tbe  txattricr 
ntarginal  mni-  or  I.ifMU<-r'x  xone.  indicated  in  Fig.  177  by  ui,  (.,  nfaidi  lis 
bMwcen  the  actaal  rxtrvmity  of  the  l«)ni  and  tin-  iturHiee  uf  the  ct)nl.  anJ  n 
the  upper  ivgioiu  of  the  cord  (cf.  Fig.  ITii.p')  ninn  »i>nie  wav  H|i«-Bri  'O 
Ihe  laternl  margin  of  the  hoto  heiwct'n  the  gray  iiintter  and  the  i-n* 
|)yn*mtiliil  tmct.     As  it  nsc«Dds  thin  layer  eontiniiidly  gives  off  Hlin-*  ti^  iH 
gn»v  matter  of  tbe  pwtlerior  bom  in  ihc  cclla  of  which  ihey  ai>[>ear  In  mil- 

TbuH.  while  part  of  tho  median  hundto  dow  ni>t  join  the  grnr  Qiattvii 
all  hut  goes  to  form  tlie  median  posterior  triict.  the  t\-«t  of  thai  ^imdli'^" 
all  Ihe  other  tibresof  tbe  root,  sooner  or  later,  join  tlio  gray  matter  eiik-ral 
the  posterior  born  or  of  eotne  o(ber  pitrl. 

S  571.  Tke  nteial  fentvrt*  of  the  *nftral  rtyiouf  of  Ihe  tjnnal  roriL    Tw  _ 
cord  begins  below  in  Ifae  Blender  (ilameot  called  the/f/i<wi  imninuU,  "h'' 
Iriog  ill  tbe  venebral  aoal,  in  the  midst  of  ihe  mn^  vt  uene  root*  a)" 
(Be  raifrfu  MNiiio,  raj^dlv  mlnrgca  at  about  the  level  of  tbe  first  lumbar  < 
tebrn  into  tne  ronu*  mfifullnria.    This  may  be  refjaided  aa  tbe  beghiaiiig 
the  lower  portion  of  a  Aiilform  rnlarfceinent  of  the  cord  knuwn  as  the'iw' 
twrlliny,  wliteh  rrarhn  na  high  ai  about  tbe  attachment  of  the  n>»ti  of  w^l 


M 


THE   STRt'CTURE   Of   TlIK    SPINAL   CORli. 


U9J 


or  ckvODtb  thoracic  Dcrt-v  iit  (hi>  Icwl  of  itifi  otghth  thoritcic  vcr- 

,tb*  brottdoMpanof  tbo»u'ellinj;  Ix-iag  nbout  i>n|)o«it«  tbo  third  liimbnr 

Abore  the  lumbar  swelling.  Ihrutigh  tho  I  tioracir  r^i^nn  tho  soni«- 

■rbst  Barrcmeal  cord  retaioR  nboui  the  satiiic  <linmi.'Uir  unlil  it  mchvs  liie 

l«ml  of  Um  6ni  or  kcodiI  tboracic  itcrvo  o[>iKisi[«  llie  scrcnlli  ccrvicnl  vet- 

'  Ubn  wbor*  a  Koood  fuAifbrm  onlurgi?n)unl,  tho  arrvical  twelliny,  hroadur  mid 

',  tOBMr  than  Uh  lumbar  swelling,  hcttitii.     Tiw  brnndcsl  jmrt  of  the  ccrvimi 

'  fmullDg  ia  about  oppuaite  to  the  HlUi  or  sitth  cervii-ol  nerre ;  fri)m  thcnra 

ihi*  diameter  of  the  cord  becomes  gradually  Honiewhat  lew  until  It  beginfl  to 

rxpaod  into  the  bulb,  but  even  in  the  hi);heet  part  id  greater  tbaii  in  the 

thoracic  repoD.    The  seotiinsl  area  of  the  cord  increases  therefore  from 

below  u|tnrard,  but  not  rej:ul«rl_v,  the  irreKularitr  being  due  to  the  lumbar 

aD(l  oervii-ul  awelliugn.    The  extremity  of  tbe  lilum  termiosle  is  said  to  von- 

MM  eDtirely  afueurufclia  closely  invtsied  by  the  membntiiea,  even  tbe  oeniral 

caaal  beiag  abMut.    A  little  higher  up  the  central  canal  bei^us.  and  nerve 

celb  with  n«rve  fibre*  make  tbeir  uftpearsnce  in  the  iieuroi^lia;  thus  a  kind 

of  gray  muttt'r  cowrvd  by  a  ihiu  flU|>erScial  layer  of  irhite  mnlter  ia  e«tab- 

liabnl.     We  have  ulruidy  rfforred  to  the  peculiar  features  of  the  lower  end 

of  Um  cddus(SM>6):  hut  higher  up  the  canal  bocniDes  central  and  small,  the 

poiUrJor  otdunin*  are  dcvulo[>«Hl,  and  the  gray  matter  oont^na  more  uertrtnia 

eluMOta  and  rvlatiwly  Uaw  neuroglia,  licc»>m«a  in  faet  ordinary  gray  matter. 

Fttiin  ihencc  onward  tn  very  nr-ar  the  junction  with  the  hulh.  where  iraoM* 

tional  fralurei  begin  to  come  in,  the  Dpiual  curd  luuy  l>c  Mitl  to  have  the 

gmeral  >4ruclurc  prrrioiisly  dmcritiMl, 

Tb*  »r«-tiotial  area  of  the  whtKt  matter  iiicrCMes  in  nhnolutv  lixc  and  on 
the  wivde  in  n  Btendy  miinner  from  below  ujiwafd.  In  other  wonU.  in  n 
•K4>on  lit  any  Icrcl,  the  nimdicr  of  longitudinal  libra<  forming  the  white 
matter  it  greater  than  the  niimlicr  tit  a  lower  level,  and  lc»  than  the  numlier 
at  a  hiicher  level ;  for  any  dilference  which  may  exbl  in  the  diameter  of  the 
individual  fihrv^  ia  tnsuflieieni  to  explain  the  diffhrenoes  in  tbe  total  sectional 
area  of  the  white  matter.  If  we  were  to  measure  in  man  the aeetinnal  area 
fiFeacfa  of  tbe  Hmnal  nerves  aa  it  jmns  the  cord,  and  to  add  them  tocher, 
pawung  along  the  coni  from  IkIow  upward  the  remits  put  in  the  form  of  a 
mr^-e  would  give  uiMomfniich  llji;tiren4thnlahown  in  Kig.  17!);  the  area  gained 


rat.  in. 


V  w  ••  *  I  V  f*  '[  Ti  bu  X  awn  ^Tv  n  a  ii  i  ww  it  «  lii  ■  li  I 

\  MMvUHi  TiK  I^KiTOU  jinmoMU.  ARLia  or  rna  SruuL  Xmvri^  raacanmc  fsoai  Bauiw 

lD«aKa*lata*<iHva>idlvacTO,  l»^l«LIV,IU.tM.altar«hlebTatata  m*n.  ta*  Ml  toml 
,'jMt  MtHmaU  tlw  t>4l«D  uf  IW  (wnlMiiil  Uic  >l(lil  liauil  tlulupoftlui  rutd,  tlu  iMitiinilt  latl> 
(wltag  mn  1 1—  1 1  tj  ilw  BcnU,  lomtHt,  ihunwir:  «ii<t  raidiMl  niRTn.   Trti  smnl  driiv*  wv  ai4 
ilmwa  la  Uit  midv  m«1c 

by  adding  logotbor  the  ve^liounl  areas  of  the  nerv«s  iiioronM  in  a  fairly 
•uady  manner  (Vow  bolow  upnard.  Tite  cnrre  of  tba aectlooal  urea  of  the 
whit*  Bkolter  of  tha  cord  taken  from  below  Hpwar<l  would  be  very  nmilar, 
but  if  anything  noro  mftulnr  It  must  ho  onderaioud,  however,  that  the 
idiawnnonaaf  the  aren4  would  not  b«  the  tame  in  ihetwovafct.  The  oeotional 
of  tha  «hi(«  tu:itler  at  the  top  of  the  cervical  region,  though  greater 


0S4 


TOE    SPINAL   CURU. 


thiiD  niiTwlitrc  lover  dovn,  i«  fur  Ires  Itian  tho  nnihd  Hcllonil  imtf  ill 
lh«iionTe  hi-liiwlliBt  level,  ThcTihitc  mailer  is  nnl  Jbniio)  I'j^all  ikrHInt 
IWtm  the  nervci  nhieli  join  the  (pioiil  eord  conlinuing  lu  run  aloDg  tkenr>i 
up  to  ihv  brniii ;  ns  we  hnve  eccn,  foaw  at  least  of  llie  fibrea  eud  in  (ktgnr 
mailer.  NcTcrthelew,  the  wliUe  matter  in  piming  up  tbe  cord  appon  f-i 
receive  a  permaiicitt  sdttition  iit  ihc  cntrnnce  of  each  iierve.  We  niiiT  iaSti 
tliat  each  Derve  lins  a  representative  of  ilEelf  starting  from  the  left!  tf  ib 
ettlraiiee  and  niDning  up  to  some  part  of  ibe  braio.  Whether  ik  flhm 
thus  roprefenlnlive  of  the  ucrve  are  coDtiuuali<jnB  of  llie  very  fibre*  ef  ihr 
nerve  itself,  or  are  new  fibres  starting  from  some  relay  of  gray  mailer. «ilh 
which  the  fibres  of  the  nerve  are  also  connected,  is  aiiolher  (ineslion, 

m.ita. 


/ 


V  lY  iH  u   I   *  (»  <ii  11   I  111  11  »  K  I*  « >n  V  f*  !•  "  1  in  lAi  -fl  V  w  ■  n  ' 

tnicaiv  •wxiiini  twR  Virutuum  im  tub  AimewAL  Asa*  or  tilt  flai*  H*nM  or  iWMOu 

CoaD  IlUhiii  tn  LMutu. 

5  672,  The  gmy  mutter  in  contrnst  to  the  white  mailer  showa  great  v»ri»- 
tiuDs  in  nrcn  along  the  tciigih  of  the  cord  (Fig,  \IHl).  From  the  enirauw 
of  the  CiK-evgenl  nerve  upwurd  the  nren  iiirrea»e#  very  rapidly,  reaching* 
maxininm  at  about  the  level  of  the  fifth  liiuibar  nerve.  It  then  rapidly  •!(■ 
creoacB  to  about  the  level  of  the  eleventh  thoracic  nerve.  maioiuii»  abuut  ibe 
ttinedimetuionsall  through  lliethonieie  region, and  be){iuH  tt>  incrcue aciio 
at  about  tlie  level  of  the  second  thoracif  nerve.  Its  weond  max  imam  ii 
reached  at  about  the  level  of  the  fifth  or  sixth  cervical  nerve, afUr  whicb  iht 
area  again  becomee  smaller,  remaiuing  honever  at  the  iip|>er  cerrical  TtgMi 
much  larger  than  in  Ihe  thoracic  region. 

i>S,l»J, 


Ducaui  OMiBtMi  nu  BtijLiiva  Sktiiwi.  Aa«u  vr  thk  8nK«i>  XKHtvi  *•  iimi  >n%  t«i . 

Smju.  (Van. 

Tbe  meaning  of  these  variali{ms  bceonies  clear  when  we  turn  In  Fig.  181, 
whieh  shows  in  a  similar  diagram  mat  ic  manner  the  seclionnl  ureas  of  ihti^ 
•everal  spinal  nerves.  It  will  be  ohcervcd  that  the  increase  and  deorea:*'  nf"^ 
the  sectional  area  of  tbe  gray  matter  follow  very  closely  the  increase  am) 
decrease  of  the  ijuanlity  of  nerve,  that  is  lu  say,  neglecting  dJHereoees  in  th» 
diameter  of  the  Bbres,  in  tbe  number  of  nerv'e  fibres  putting  inlu  the  iiin). 
Tbe  Hdioiniil  areas  of  the  first  and  second  Ba(.'ral,  fourth  and  fil^h  liiiubar 
Dcrvea  are  very  lar^se,  and  0|>p<i8ite  In  ibeee  the  sectional  area  of  the  grar 
matter  nf  the  curd  is  very  large  also ;  tbe  eularv'^ment  of  gray  matter  wTiirk 
ia  ibeeownlinl  causeof  the  lumbar  swelling  is  ciirrelated  to  the  large  number 
of  fibres  nhich  cuter  and  leave  the  curd  at  thU  region  to  sup{>ly  cbictly  tW 


rnS    »TRUC-TL'RS  OF  THK  SPINAL  CORD. 


69S 


limrr  limh*.  Similarly  Uiv  rnlnrgenieiit  of  grny  lowtk-r  vrliioli  in  llie  ctwn* 
till!  onUKC  »r  thi'  coivtcnl  »wdliii^  it  orrvlatcil  to  lh«  Inrgi-  number  tif  flhns 
wbirlt  eut^r  niiil  lonvr  ibii'  ri-giun  of  lliv  vorfl  (o  hu|)]>Iv  cliii-tly  l)ie  u]>[ier 
linib*.  III  the  tbonini'  n-giim,  wlicrv^  Ihc  number  ol  nl)i>'i  vtilcriii^  iiud 
Irnvin^  ijiccord  h  rvlntivcly  liM.lhi:  wt-lionnl  oreiiof  tbe  gray  niiiltcr  i«  bImi 
ins.  Sinco  tliv  miiK-liUKtitii  uf  the  ^owntl  »|>1iwl  nvn'tv  nr«  not  exiii;(lT 
uidiiliint  fmm  nrh  «tht-r  along  iIk-  Irngtb  of  tbc  i.-nr<),  lliv  wclioiiiil  iirra 
it  *o  Gjcnct  mnsure  of  bulk ;  iho  toml  bulk  of  gray  mnlU'r.  Ibr  inrttiiice, 
iging  to  tvo  nerves  which  cnu-r  tli<^  coixl  clo«e  tog«ltier  is  lees  tlnin  thnt 
two  nerree  fpvin^  nte  to  (he  *ame  Kctional  hkii  of  gray  nmtlcr  as  the 
iibrmer  two  but  entering  ihe  cord  far  anarl  from  each  other.  Still  the  error 
'~hicb  nay  l>e  iiilrvHluL'e<l  by  taking  seclional  area  to  mean  bulk  ia,  Ibr  preaeut 
rpotn  at  all  events,  so  &iusll  that  no  may  perntit  otirvelves  to  say  ihst  in 
(the  tHjccessire  refpons  of  the  sfttnal  cord  the  bulk  of  gray  malur  in  any  sey;- 
uent  »  sreatej*  or  lees  according;  to  the  size  of  the  nerve  (or  pair  of  nerves, 
tight  ana  left)  belonginK  to  that  sef^ent. 

rVoin  Ibis  auatomicfll  fad  we  a]>pear  jnstilled  in  drawing  the  conclu«oD 
thai  at  all  eveula  a  great  ileal  of  Ihe  gray  matter  of  the  spinal  cord  luav  be 
eaoHiileret)  tat  funiialiing  a  nervoua  mechanism,  witli  whieh  the  dKirenl  G^)res 
pf  each  »|>inttl  uvrrH  lUHt  Iwford  they  leave  th<?  cord,  an<l  llie  afferent  Bbres 
■oan  alXcr  thev  join  tli«  cunl  %Te  uioru  immediately  connected.  It  may  be 
thill  iIm;  whole  of  the  gmy  matter  in  thua  directly  ooniiovtetl  with  and  tbii» 
rwMi  ami  fall*  with  the  JihrcM  of  the  niTvcx;  or  it  may  l>e  thnt  there  u  v  iiort 
of  nort)  of  gray  matter,  which  maintain:)  a  tiiiiform  bulk  along  the  whole  icngtli 
of  Iho  mrd  and  servt«  as  a  basin  uhieb  i-"  here  more  and  there  \<xf  nwoneii 
bv  the  addition  of  the  eray  nialttx  more  ininKxlialely  connected  with  the 
ibrtw  of  the  nerves.  Thie  question  tiie  method  which  we  are  now  using 
noot  settle. 

§  S73.  Owing  to  these  diflerent  ratot  of  increa«e  of  the  gray  and  white 
Iter  respeelifely  along  the  length  of  the  cord,  we  find  that  in  iections  of 
e  cord  taken  at  difierent  levels  the  a{)|)earancea  presented  vary  in  a  very 
i«tinct  manner.     Tlii»  is  strikingly  shovfti  by  comparing  Figs.  174,  17(1  and 
77.     Ax  the  level  of  the  third  luinbar  neri'e  (Vie.  177)  the  gray  matter  is 
ery  large,  rvachinfc.  as  we  haw  seen,  its  maximal  sectional  area  at  about 
ie  point,  so  that  although  the  area  of  white  nkalter  is  not  very  great  the 
hole  area  of  the  cord  i*  imnsitierabla 

At  llie  level  of  the  aixtli  iboracic  nerve  (Fig.  174).  ui  spite  of  tbe  wbiie 
matter  having  ver^'  decidedly  increased,  tbe  gray  tnut(«r  has  nhrunk  to  sitch 
rcry  small  dimensioDM,  that  tne  total  aectionalurea  of  the  coni  hu*  markeilly 
limioished. 
At  Ihe  level  of  the  nixih  cervical  (Pig.  176)  the  gray  matter  bun  again 
iCreaaed,  reaching  here,  an  w«  have  seen,  itn  nerond  maxiniiim  -  the  while 
wUtcr  haa  also  further  increaneil,  ami  thni  in(lei.-<l  very  ranniilcrahly,  so  that 
le  total  an-a  <if  the  cord  in  much  greater  that  in  any  of  the  lower  regions. 
Further  driaitn  of  tbe  varying  ?wc  of  the  white  matter  and  of  the  gray 
i«r  HI  diHt-rrnt  levels  are  aUo  thown  in  the  series  given  in  l-'ig.  1>!'2.  In 
couibiniil  with  the  three  tigurw  jn»t  referred  to,  it  will  be  obserx'od 
,a1  the  iK'Hal  iucrmsc  and  decfetuc  of  the  gray  matter  does  not  street  all 
r)d  of  the  gray  matter  alike,  so  that  the  outline  of  thejjray  matter  changes 
ry  markoliy  in  pawing  from  below  upward.  In  thflooocygeal  renoa  each 
teral  half  is  a  somevhal  irregular  oval,  aiid  iu  the  sacral  region,  r'ig.  I$S{, 
c,  the  diflerentialion  into  anterior  and  posterior  horns  is  still  verv  indistinct. 
ihtj  lumbar  region  ibe  two  hurna  are  nharply  marked  out,  tliough  both 
posterior  and  anterior  hon»  are  broad  and  more  or  leM  (pia^lrate.  In 
thoracic  region  the  decnuise  of  gray  matter  ban  aHectuI  iKilh  lioru*,  m> 


690 


THE  SFIKAL  COBD. 


Iliflt  t)ath  Ar«  pointed  and  tlandar,  while  tli«  junctMn  tietv«>n  tHeni  liu  i 
uiKlerj^oiie  hi  luiicb  itiadnutiOB,  so  tint  what  liua  hceo  calleil  (iie  lal^nil  Imrn 
is  relatively  cunspicunua.  In  tbvoerrioal  reffioo  tlieRtiirDini;  i^^m<eltfl^ 
cnucb  more  on  tlie  anlerior  hum  which  again  becM>mn  lur;f«  and  bruad,  ihtn 
on  the  poMerior  biim  which  *lU\  remains  *i en der  and  )i-tiDled.  Taluajilir 
form  or  the  gray  luatlcr  in  the  thomdc  rugimi  na  the  lunn?  lypicitl  fnrm'f 
the  gray  matter  we  may  «uy  ihni  whik'  the?  increiui-  nii  ihe  lumlnr  twtWm: 
bean  equally  oti  the  anterior  and  piNtcrior  hnrnit,  ihiit  iu  ih^  fcrs'icai  iv^hd 
bean  chiedv  on  the  ant<-rl»r  horn*. 

Now  we  have  no  rafon  (o  «iip)>inio  that  cither  affcrcnl  impulMS  reat^iliF 
luinl>iir  npiuiil  cord  in  grcaliT  nuRibcni  fn>tn  the  lower  limbu,  or  al'iiii;>i>Trif 
the  iiervw  joining  tlii»  part  nf  tlic  conl,  or  that  tlwwc  which  do  mulm 
■re  of  n  more  Icomplex  iiatitn;  tlian  i»  the  cn>c  with  llw  nflirrent  impul» 

Fui.  tlCL 


■7 


y 


Ct. 


..Ur, 


Cs. 


dp 


.^.. 


kl^ 


y|i': 


c«. 


U. 


AH  lUfSTBAnxc  Kon.  or  rn*  tujvaa  or  tub  Srauii.  uontt  xt  Dirrum  Lanuk 
I0imuximu>.) 

OwMvtWMvitnini  id  (lalD.  knit  nivwant  the  eonl  maciiMMl  fmr  iiiiml  Tlier  ■'■'>*  "■■ 
H>«*  M  ■UlhnM  WnrU  In  lbu>lmp«  taatlaal  tliDtaciI.  la  tha  ouUlUe  b<  lbs  Rtmy  iimllet,  aod 

nlMlTa  poriUoo  of  lb*  uurinr  Mid  inawrlnr  flavm.  Mid  ate  tbivw  U>t  tahMlont  al  dUhnnt 

Of  Ow  MTinl '  OMU  "  o(  Ibc  vhlw  mkltet. 

4ilMt**plofihaMiwiil«fftTlfBl  Mrv*.(^af  UMARImrvlnl.  r.nrib*  vlfMkoornlnil.    I>i«f 

•MiHMl  tli<waclo.t>(nf  Ihc  tilth  Iboraclc  L|Of  thannl  limhir.  I4  Wlbr  BRh  Intntiar.  aad  Mc. 
I  ivenflil  mcnl  Orttve, 

>rtiadlasar  tlwinra>wvih>ainifiiu  In  Mi  ITKi  bMin  Uw  nadlu  partiHar  aolnau  of  t>t 
OBSf  flbtnoHiUnsiViMnilicivnl  Dtrra  i.  f-,  mq  IumIwj  anrm  li.tn  JUantitAttA  ftom 
«B.d.  r.  ofiUiimbtlMicIng  10  ita  iliurKlo  iwrtm.  Inl',i»4Utliiciiaa  k  nM<to bvlwcvn  aiij' 
<•«><* of  llhm i  Ib  l.loDlf  BliKiuf  •■rntl  iiniia  iiii  11  |n ■■mil it ;  to  UDiIV  (he •<•« dona) 

|«ttliM>  conopiiuili  lu  Mcnil  ttirt*  *i»l  iIk  aeil  la  lumbar,  nr  liuntar  Uumcli'  wrim. 


hiBg  the  cervical  oard  alooR  th«  nerrw  of  th«  apptr  limbo.  Th«  incraaM 
•jr  nnlter  iii  the  posterior  bonw  b  therefore  uot  correlated  tn  any  in* 
le  In  ibc  Dumber  or  compleiitr  of  Ihcaflcreiit  impulses  rMchiDR  the  con! : 
we  may  imiviaioimny  concluilo  ihiu  at  leuat  a  larjie  part  of  ihe  |[rny  mntttir 
w  pueterior  honi  it  not  ipedally  conoeroed  in  any  i^IatHimiiim  or  traof 
alMO  of  aflkreDt  impulsea  immnliately  upon  their  nnival  ai  tho  ooid. 
•d,  wc  liavo  seen  that  trhili!  there  b  ample  eridence  to  oooneot  the 
B-{vlk  and  therefore  pranimably  the  gmy  maU«r  in  genoral  of  tlie 


T«B  SPIN&L  OOBD. 


kflfB  wilk  lb*  rSrrtnt  motor  Akm  of  ihc  onli^rior  nvit.  tli«fic ' 


Urn  al  tb«  ftatmot  mot  villi  tbr  Derv«-c«tli>, 


{ir  iiiili«<l  Ally  iiLlirr  rmn  I 


Um  mj  mallir  of  thu  poMcrior  boro.  We  niair  odd  (hat,  km  «<>  uliall  yA** 
i«t  Mttr  oa,  Ki  MiiHial  i*  ibt  canrarreiice  nf  iigiproiiriitu-  iifTcn-ni  inip")*n  y 
Uw  duetxriyiiiEiMtof  cmnplexeoaHtnmtL-RM>t(ir«rdfi-rviit  ini]>ul«ft>.  llu<*' 
as  tcvcrlr  ezprrt  Iti  find  sdt  faicmuw  in  the  ncrvou*  mMhiiniiiiiu  i]<v<mI 
to  tlw  ponly  BMtor  fiiDcUeB  of'wrying  out  nxitor  imptdvo  withnui  ■  com- 
spoodmg  iaamm  is  tha  armut  mufhiianma  tmlon^nji:  u>  llir  atlirnvi 
inpalm.  by  tneatis  of  whieb  thnt  notor  iiD)xilsn>  are  guid«Ni)  and  eunrdinahii. 
HflDCP,  were  tbe  \aiur  DcmMis  Dwduuuflim  raslriclcd  to  tb«  posMrivr  bonp, 
««  aboald  expect  lo  find  ■  gnalcr  p«ra1l«li>ra  (ban  dot«  Bcttially  «xb(  bc«nm 
tfaeiB  aoil  ih«  anterior  liom. 

(  V74,  Tka  ehaofa  in  the  arm  of  gray  mntlcr  illiMmtnl  by  tho  ttvt- 
■tute  ud  llim ■Hill  given  above  n-trr  tu  ibe  gray  matter  ns  n  wbnlf— ibil 
n,  not  only  lo  sene-celk,  but  alH<  to  slrands  and  uetworks  of  nerve  lihrtt 
and  nerve  tibrik,  awl  indeed  include  lo  a  certain  extent  neurt^lia.  ^Vr 
hare  Men  (|  o67j  that  we  an  able  to  ditti»];uif.h  certain  large  and  e» 
HMcaons  nerve-cells  in  tbe  gmy  auuier,  and  to  arrauge  tbeae  iitto  KToafi. 
The  gray  matter  enatains  loaoy  other  small  iMrr^oelTs,  which  we  ntewt 
able  at  preaeat  to  nane  or  arrange,  btit  uhne  existence  must  aJwan  h 
faarse  la  mind.  CoofininK  oorwlvt^  now,  hnwe\'er,  t»  Uie  grftupa  of  larev. 
nore  conipiruvus  iKrve-<«1ls,  «e  find  that,  broadly  speaking,  the  dlie^dt^c^ 
eoccB  whi*^  can  be  obierved  in  tbe  rells  of  tbe  anterior  tioru  almii;  ilx 
length  of  the  cord  are  that  in  the  thoracic  recnon  tlie  iier^-o-i--ella  of  tbe  sau- 
rior  honi  are  few,  ami  relatively  small,  wbUe  In  tlw  L>ervical  and  lurahu 
region,  eapeciaUx  in  tba  latter,  iltey  arc  numcroa*  ami  large.  It  n  not  ewy. 
even  if  pn«iU«,  to  ^lin^txh  inlbe  thorade  region  tbe  ncvcral  gm[H  rf 
cells  marked  in  Rga,  176  and  117  at  'ia,  ,i, ;  :  On'  rowlian  group  ( Fi|:-  iTn 
17'.  1),  indeed,  Menw  tn  ba  iba  only  group  pnvent  in  thi-  mi'ltln n >'  , 
regioo  (Fig.  17-1.  t).  The  group  of  tno  |>oaterigr  Ixtni  (Fig«-  174.  17ii.  I^<^ 
6)  anrpaKn>  Ui  be  about  the  same  in  all  n^ion*.  ^M 

Vt  ith  two otbcTgioupf  of  nerve-cells  nriking  diflctvnon  are  weii  in >ii/- 
ferent  rcgioiw.  The  vehicular  c}-lii>der,  for  instance  (Fig.  174,  3),  i*  m'* 
conapicuous  in  the  thoracic  rr^on.  It  niav  ))«  eaiil  to  reach  frira  ih<- 
MTCnth  or  eighth  cervical  nerve  to  the  thirti  lumbar  nerve,  being  [n'lhsj^ 
Dioet  developed  in  tbe  lower  thoracic  and  iipiier  lumbar  regioa-  It  ■ 
abaent  in  tbe  cervical  region  above  tbe  seventh  or  eighth  oervical  aerv^«»l 
in  tbe  lumbar  region  below  tbe  third  lumbar  nerve;  but  a  itniiUr  ^r"  I'  ' 
oelle  ifl  prtseut  oppoalle  the  aecood  and  thinl  cervical  nerves;  as">"i-".' 
more  doubtful  likencn  la  aeen  in  the  sacral  region  below,  and  the  coIuub  » 
•aid  to  have  a  repiveentative  in  tlte  bulb  above  the  epiual  cord  proper.  !■ 
■eenis  natural  to  infer  that  the  mU»  forrtiiug  thia  vesicular  cylinder  an""- 
necled  neither  with  the  ordinary  somatic  motor  libres  ^reming  Iho  sln^ 
muscles,  nor  m  ith  the  ordinary  alferent  setisory,  aomaito  fibrei  ootniag  ft"* 
the  skin  and  elsewhere,  hut  in  some  way  with  some  special  twin  of  flbrwi  ii 
tbvpoint,  however,  no  niitlKmtati\-e  statement  can  as  yet  lie  inndc. 

Tne  lateral  bora  or  int<'rm<'ilii>-laieral  tract  (F'ig.  Ii4,  4)  i«  also  mod 
Rpleuous  tn  the  ihnracic  region.     Tn  the  lumliar  region  it  h  Icitt  or 
with  great  dilliculty.  anil  in  the  cervii-al  ri-gion  veenm  tn  W  memd 
miift  donuilly    plao-d  divinion  of  the  latrral  group  of  celU  of  itui 
burn.     It  in  iKwitilo  that  (hie  j^roup  ivprMtiiH  in  thr   liniblnw  ilt< 
region  the  cells  which  iitv  devdoiHfi  itito  the  gnat  lateral  group ol'tlm 
rior  boni  in  tbe  regions  of  the  limlie. 


TII£    STRCCTt'KK    Of    TUB   SPl.NAl.    COBO. 


mm 


,  t979.  Tlif  wliire  mnilor,  ae  wo  havo  ee«ii,  iiivreaMS  in  eeLtional  aici 
nth  ctiitniilrniblf  rrKulHrity  fruin  belnir  upward.  If,  iDstMd  ut'  a  disftmiu 
Bf  thn  ini'mivr  of  Ihi;  whol«  nhile  lualltr  we  construct  io  »  similar  way 
dbnania  of  ihe  anlerior,  {looterior,  aixl  latenil  culuiuDS  rtspeciively,  we 
lii><I  lh*t  while  the  K^-licnnl  nren  of  ihe  lateral  coluniH Fig.  l83)iu(TeaM6 
■  iih  Mom  cooiitlcimbic  rt^'ulurily  from  Iteluw  upward,  ihough  not  tu  revu- 
larly  aa  ilom  ili«  wliole  ar«a  of  while  uiaitcr,  Ixiih  ibc  anterior  (Fig.  \Si) 


I 


FM,  m 


/' 


•1   ■    I  mil  t  v  wMi  V  V  fv  <<  k   i  v<4 w  VI  i  >f  ■  "  ' 

XHMa»>  nMm*o  nia  VoitnoK*  w  nic  MmMrtL  AaRi  or  the  t-in>*t  Cilpim*  or  tut 

ariKAL  Cms  jiLMio  nt  Lnumt. 

Fki.  IM. 


I   MDVKWvavlVMHI    IVIVIWUWi    II 

«t«  •w.vnni  Twi  VA*t»Tiina  nc  tut  Skumh  Aria  or  twi  Avnaina  Votiatm  or  TWi" 
^■«i  Omui  aumo  m  Ldvth. 

Fut.  ("ii. 


i' 6  "i  ~T  ^  J  J  V  N  >  • 


I  TWI  TAKUTtMM  IS  THE  SumiWlI.  AaC4  Or  THB  I'O'miOa  fVttTVM*  or  TWI 

iVout  DwD  ALoiO)  m  LuwrtL 

BDil  tli«  pntlerinr  (Fig.  1)<5)  coluinus  aKrt«  to  a  certain  extrat  with  the  cmr 
UMder  in  «buwiug  h  dmded  iiR-r«nt«  in  both  lb«  luinbiir  and  Lh«  cetviral 
awi'llii))^.  We  maj,  prnvuiMnnily  ul  li-u.Ht,  infer  tmm  titia  that,  while  coa- 
aJdembli.-  [Mtrliuna  of  both  the  aiKcHur  mid  the  pMilerior  ooluniQs  ar«,  like 
the  ndjoiiiing  Efwy  nialter,  iu  toma  wa/  or  oilier  cuiicem*^  io  the  exit  aad 
entrumv  uf  ctJen'nt  mid  atltirriit  fibrrw,  ihe  larger  jxtrtiuu  ut  the  lateral 
coluoin  i«  coat'criH->l  in  the  cranainiMiioii  of  impiiUca  Iv  and  fro,  between  the 
local  DMtcbuniymK  hi-low,  ininH-diiitclir  coniwctcd  with  ihe  sevvnl  *]>iuul 
nenrca.  and  thv  brain  nlmve.  Thi*  cunelueion  areme  inddunttUIr  oonfiriiied 
(though  tfaew  tliagnuns  miift  not  he  i>trniiicd  to  rarry  tlotailed  tnKnnw*)  by 
tba  Midden  inereaM  of  the  lalenil  eulumn  above  the  lumbar  Kwelll0)c,  as  if 
tba  largs  maw  of  nervouB  mrchanif>m  for  tbe  lower  limla  cnuventrntud  iu 
Utia  ivgion  demanded  n  sudden  increase  in  the  number  of  Gbrw  cuiinediii):  it 
witb  the  brain  above. 

Thia  mora  or  IcM  coniiouotiB  increMe  of  tbe  lateral  oolunm  piirtljr  explain* 
tbe  ehange  of  form  iu  the  geiteral  outline  of  tbe  tninsvenc  Metioii  uf  the 
aofd  whkh    is  obierved  in   podHiDg  upward   from  the  loner  in  the  higher 


700 


TBB  SPINAL  CUHU. 


regiODt.  In  the  cocergeal.  Mcni].  tnd  lumbar  rogioDi  tbc  oatliai^  tbou^b 
TBrylDg  «<iiiivwliiit  ehwfljr  owing  to  tho  dtspositioD  ol'  the  grof  nwiter,  bag 
tile  wnolo  dreulAr.  In  the  t)ii)rticic  region,  Mpociall}-  io  the  upper  part,  ik 
loenMH  of  the  lAt«rnl  cuIuoiiib  incrensce  tho  side-to-«idc  dtaio»t«r  M  waA 
(hai  the  section  becomes  oval,  nuH  in  the  cervical  region  ihi;  incrrftN!  of  LSt 
>i(l<.vtu-Ndo  diameter  out  of  proportion  to  tlie  dorao'ventral  diiinioliT  ii  leit 
mnrked.  The  actual  outline  of  the  whole  trmaarerve  tectiou  b,li9«nir. 
(k-tcrniined  alao  to  u  certain  exlviit  by  the  ckiue^sof  forraofthegn^iiiMttr. 

The  cord  moreover  unJergow  along  iiH  length  a  change  n  liich  ig  nit  wrj 
clearly  indicated  in  lie  diagraiuH  Figs.  184,  ji^'>.  By  comparint;  the  (rtin 
of  traiiaverae  «caion»  giv<'n  in  Pil'.  IK'J. it  irill  be  »eeu  that  the  rvtaiire  |>c» 
(ion  of  Uie  cuntral  canal  Hhilti  iiToiiz  llic  Ini^th  of  the  cord.  In  ilia  wall 
and  lumbar  Tvgion%  the  cotitral  auiAlit  ncorl)'  at  (h«  centre  <>f  the  drdttf 
outline,  niid  the  posterior  nml  anterior  fissures  are  ncarljr  of  e<|Ukl  iltplli. 
Kveu  ID  iho  upper  lumbar  region,  and  still  nioro  in  (he  thoracic  r^oa.  ibr 
position  of  the  central  canal  is  ehiiled  nearer  to  the  venlml  surloos,  S4  (Inl 
the  posterior  tiuure  becomes  relatively  longer,  deeper,  than  the  oauriw. 
This  ehiltiug  goes  on  through  the  cervical  region  up  to  about  tlie  Icniof 
the  Moond  cervical  nerve,  where  it  u  arretted  by  the  beginning  of  ibt 
ohoneea  through  ivhioh  the  apinal  cord  ia  traDsforiued  into  tbe  &r  bnr 
oumplicated  bulb. 

This  leugtkt^ning  of  the  potteriorlliBure  indicates  aoiDoreajM^  in  ihe'lop*^ 
ventral  diameter  of  the  piuiicrior  coluninn.  and  thii,  not  bein>:  ficcoiiijiuaol 
by  a  compensnting  diminutinn  nf  the  iiide-bo-aide  diameter,  ahnuj  in  Inn 
that  the  pOMlerinr  ci'iliimnH  uncl<Tg<i  nn  inureoite  in  posing  upward.  I'm 
thi;i  tve  nmy  add  to  thi-  provixiona!  conclusion  juM  arriveil  at  with  regaidto 
the  lateral  columiiB.  the  further  conclusion  that  m»av  (xirt  of  tlw  pMlcmr 
columns  alao  is  concerned  in  transmitting  impul*e>,  in  a  more  or  leMdirM 
manner,  between  the  varloua  regious  of  the  cord  belovr  anil  the  brain  iiboTt. 
The  anterior  columuii  do  not  iDcreOBe  in  the  same  marked  manner,  llioufk 
over  nud  above  the  increase  due  to  the  lumbar  and  cervical  swelliugi  a  mi- 
tinuei)  increase  may  be  ob*erveil,  espeoinlly  in  the  upper  rervicid  rvgioc;  il 
is  in  this  upjier  repon  that  the  direct  pyfamidal  tract  la  best  deveiojied. 

§576.  Till-  provUional  coiiciii«iouii  at  which  we  have  arrived  ai*  furthM. 
to  a  Certain  exiMit  nl  irntt.  coaGrmed  and  eslendeil  by  a  study  of  lli* 
b^nvior  at  the  several  region*  of  the  cord  of  the  *jtecia!  tract*  of  •fciw 
nuuicr  dcscrihcl  in  ^  M'. 

The  pyramidal  tract,  that  is  to  say.  the  croMdl  pyramidal  tract  eotcii^ 
the  spinal  cord  above  from  the  pyramid,  is  vr-ry  larLru  in  the  oorvical  ni^ 
having  the  form  and  riiinilion  sihown  in  Fig.  i'<'i,  C,C,C,.     Fmm  llwaM 
doimwnrd  it  diminishes  in  sixe.  tha  diminution  being  i^pocially  ropid  la  thi 
lumbar  twellint*  (Fig.  19^.  !<,).  where  the  tract,  being  nn  loneer  covered  i* 
by  the  cerebellar  tract,  comes  to  the  eurboe  of  the  cord;  out  it  maybe 
tnoMl  by  the  degeneration  method  down  as  far  na  the  eoocyi^l  re^ioo,  nn^ 
indeed  appeiirs  to  be  coexistent  with  tJie  entrance  of  spinal  nervua  into  the 
oord.     Diminution  of  the  trad  means  a  JeeAening  of  the  number  of  fibna; 
and  since  we  eannit  mppuae  that  any  of  the  tibrat  come  sitddealv  to  an  tiA 
in  the  tract  itielf,  we  are  led  to  infer  that  alon)t  tli«  oord,  from  aliove  dom- 
wanl,  fihn-a  ari*  «uoc«Mive1y  leaving  the  tract  and  Tnuain;;  to  some  other  p«it 
of  tlw  oord.     \Vv  Mo-ni  further  ju^lifinl  in  oouvltidiiig  that  the  librae  whitt 
tki»  silcocwivHv  Icavn  the  tract  go  to  join  (he  series  of  local  Dervoua  medi- 
anisiiu  with  which  the  spinal  nervcn  tximniuuicate,  as  we  have  seen  komo 
to  believC:,  upon  their  entrance  into  the  cord.     Indeed,  as  we  aball  ae«  loUr 
OD,  wv  have  reason  to  think  that  the  ni-rvoog  mi.»oh an isnu  which  thi-(ibrotii 
qneslion  join  are  those  bclon;;ing  to  the  motor  fibrei  of  the  anterior  rooU 


TBK  STRCCTCHB   Of   Til  S  SPlSAh  CORU, 


701 


This  pyraRiidal  tract  Aoea  not  bt|;in  in  tbe  p}'niiuid,  but  may  be  traced 
(hroufifa  tbe  lower  pans  of  the  brain  rifjht  up  to  special  areas  id  the  eort«x 
nr  surfaee  of  ibe  certbrnl  hemiejiberefl;  and  very  etroDjj  reaaoDs  may  he 
brought  forwanl  Jo  support  of  toe  view  that  tli«  fibres  of  ibis  tract  are 
fibres  wliich  <-arry  inipulsee  from  the  cortex  to  succetixive  portioos  of  ilitr 
Kptnal  eonl,  am)  there  {(ive  rise  to  efferent  tmpul»es  wbtch  poM  to  appro- 

»i>riai«  skeletal  Diu!«)es.  1'lie  tract,  therefore,  ia  uol  only  a  dewendiug  tnct 
Djr  virtuo  of  the  m<Kle  of  defeneration,  but  may  he  »pokeD  of  in  a  brond 
•CDM  *«  a  trHct  of  rfrereiii  inipiiUes  deacending  ttata  tbe  cerebral  cort«x  : 
and  indcMl  it  i*  rnainliiiuvd  thnt  it  in  the  channel  <if  the  pHrliiolar  kind  of 
efferent  impulM'^  which  we  hIiuII  >|ii-iik  of  n»  voluiitnry  or  viililiniiiil  impiilus, 
Wv  may  mid  that  »*  tbe  tract  jiuiu^  iiloiig  ii  |iiilh,  which  »<■  iilinll  siihM- 
Inueiitly  <)4«cribe,  from  the  cerfliral  cnrtex  through  the  loner  |>iirt«  of  the 
Drain  to  lh«  pyramid,  it  givn  off  librca  to  mecbaniiimN  coniwcted  with 
aeveral  of  tbt  cranial  Dervo.  mucb  in  the  aam«  way  that  it  gives  off  fibre* 
to  the  apiuiil  nervca. 
We  muy  therefore  picture  to  otinwivw  tbie  pyramidal  tract  ai<  itarting  iti 
tb«  form  of  a  bnmd  sbcnf  of  lihrcs  frum  n  certain  district  on  the  surface  of 
one  of  the  cerebrnl  hemispheres.  I'nltin^  aside  lor  the  prMeut  imy  pouible 
increaae  of  the  number  of  fibrtv  by  dlTi»ioi)  of  libres  I  though  we  have  reason 
tu  think  that  this  docs  to  a  ccrtitin  extent  occur),  we  may  regar<!  ihe  trad  as 
being  at  it?  maximum  at  its  l>eginniiig  in  tbe  cortex.     As  il  descends  to  the 

I  decussation  of  the  pyramids  in  the  bulb  it  loses  a  oertaio  Dumber  of  tibres. 
which  paaaotr  to  the  cranial  nerve:^.  Having  croased  and  entered  into  the 
lateral  column  of  the  cord  it  cooLinues  to  give  off  libres  to  tbe  spiual  nerves, 
probably  to  tbe  anterior  root  of  e«cb  in  succession,  aiul  so  goes  on  its  way 
down  ihe  conl  coiiiinually  diroinisbing  until  the  last  remaming  fibres  ore 
given  off  ii>  the  liul  oicvygeal  nerve. 
When  degeneration  a  set  up  along  this  tract,  as  may  be  dono,  by  injiiriex 
to  |Mrticular  aieus  of  the  cerebral  cortex,  die  main  raasa  of  degenerateil 
fibrvK,  iiAer  croaaing  over  Ooni  one  «idi'  of  the  oerebn)-.i{HnHl  axist  to  the  other 
in  tiK-  dcciMtation  of  tlw  pyrainidn  at  Ihe  lower  end  uf  the  bulb,  during  ilt> 
further  pnigmw  ilown  the  spinal  eord,  keep*  to  the  i>iile  to  which  it  bn* 
cruaaed  right  doirn  to  the  end.  Hetiee,  aa  we  have  »uiil,  it  Lt  c-idl«^l  tbe 
aevmed  pyramidal  tract.  Th<!  main  mavit  of  Rbru,  thv  dvgcncrntion  of 
which  ban  Ikxih  ntnrtnl  by  injury  to  the  left  ulilc  of  tbe  bruin,  croKMat  over  to 
Hgkt  side  of  the  Kpinid  cnnl  niid  run*  down  ihi;  Intrral  column  of  the  right 
nua  to  the  end  cf  th<^  cord.  Nrvcrlhclem  Kime  fibni'  appear  to  ci«w  over 
igsiu  in  the  spinal  cor^i  and  tWn  to  run  iil<iTig  tli«'  »inte  mic  as  tbe  side  of 
tfao  brain  injured — along  the  left  side  in  tbe  caw  just  mentioned.  Sucb  fibres 
atv  upoken  of  as  "  ro-CTOfsed  Bbrcs." 

The  direct  pyramiilnl  tract  I  Fig.  I'^'i.dP),  except  tbiil  it  does  uot  cron  at 
the  iltKrusGatidD  of  the  pyriimidK.  Is  olh'.-rwi.<c  <imll»r  t'>  I  he  crowed  pyramidal 
tract,  and  indeed  is  a  part  of  the  same  i^triind  to  which  the  CTOHod  tract 
l*elongii.  When  degeneration  in  this  trnut  is  slartixl  by  injury  to  particular 
%fta»  of  the  cerebral  cortex,  say  on  the  left  half  of  tbo  brain,  the  deseocra- 
tioo  may  In  traced  ihruugb  the  left  antei^or  pyramid,  and  so  to  the  left 
itiiKiiao  anterior  column  of  the  smnal  cord,  'rhe  direct  tract  is  never  so 
tsl«DBiv«  or  marked  as  Ihe  cr'>«sed  tract,  does  not  reach  so  far  down,  is  much 
imrt^  Turiable  both  in  tengih  and  in  sectional  area,  and,  as  we  have  said,  is 
timoet  confined  to  man.  Diminishing  as  it  deecemh,  it  ntay  be  said  to  oeaw 
tho  middle  thoracie  region  (Fig.  IS'i,  DyDJ.  Taking  an  average,  we  may 
%y  that,  of  the  whole  Mrnnd  running  in  the  pyramids  above  the  decussation, 
fcbout  three- fourth.4  of  the  &hfta  go  to  form  tlie  croaaed  and  about  one-fourth 


form  ibo  direct  tract. 


go 
We  xholl 


see  later  on  that  the  impulses  coming 


702 


THE  SriKAL  CORH. 


dova  ftlong  Iho  iinitod  tract  [q  tbe  bnln  may,  bnit'lly  iiji'^akin;.  bo  Mid  I* 
OKMB  over  wholly  from  one  »\de  fi  the  nilier  'l>i-r<in:  tfaev  roai-h  lb*  tkclttil 
tDtiselcs.  SO  thftt  lh«  impulses  pasinj;  alonj^  fibre*  In.uy,  tho  loA  iirrisM, 
reaoh  the  muscle ^  of  the  rit^ht  limbs  atid  rivht  nie  of  tlif  bulr,  wli<ib«  ibr 
flbrej  croos  over  al  the dei^nMntiou  tn  firm  ibe  crvHWrl  or  romn'm  nn  lk(  luif 
side  to  form  tb«  direct  pyramidiil  trael.  Wu  nre  tlicrcforc  Ird  I'liofrrrUtf 
the  flbrea  io  the  direct  tract,  tn  ibey  paia  down  the  cord,  croM  ovor  in  iht 
onrd  itaetf  before  tbey  make  coDoectioDt  with  thu  ii  lin-4  nf  tbe  noierior  roit* 
t*nil>3bly  the  cruuiii);  '\»  efTdetod  bjr  mcam  nf  witne  of  l)i«  doca<«stiB^  libnt 
whi<'h  form  the  anterior  white  commiMun^,  A  purt  only,  ioilCMl  a  roilt 
part,  of  thy  commiwiiMt  ran  ^rveihi«  purpose;  nuMt  of  lli«  fibrtM  nf  tb»oiiD' 
inimtirt-.  and  id  the  lower  regions  of  tho  cord,  where  the  direct  tract  no  loiigK 
oxt*l»,  nil  the  fihroi  must  have  some  olhor  functions.  Some  of  th«  Glmttf 
thU  great  pyramidttl  tract  leiive  the  tract,  >w  we  have  mhI,  to  join  tomtt 
tbecnnint  nerves  boforv  the  nymraidx  nf  the  bulb  are  readied;  aad  iht 
iiDpulfcs  pa»ing  along  ihcso  tilirfa  al»o  cro««  over  to  the  oppanle  side  befbrn 
they  issue  aloii^  tbe  cranial  nervc:«.  Hcnco  wo  infer  that  tneae  6bra)  dow- 
eate  above  tbe decussatioD  of  the  i>yrnmid«  ju«t  aa  thoeeof  the  direct  tnd 
deeuBsate  below  il  So  that  of  the  whole  strand  as  it  leaves  the  oeitbnl 
cortex,  while  the  main  maas  of  libree  croues  over  at  the  deouasuJon  of  tbe 
iiyramidi,  the  rest  of  the  fibres  croes  the  middle  Hoe  in  auooenioQ  fVom  tte 
Uvel  of  the  third  cranial  nerve  to  the  level  of  tbe  lower  limit  of  the  ditMt 
tract :  below  the  decussation  of  the  pyramids  the  eroaHfig  takea  place  by  nxini 
of  the  anterior  coniniisaure  of  the  cord,  above  the  decuaaation  by  raeaaiof 
what  we  shall  later  on  learn  to  epeak  of  as  the  rapbd  of  tlie  bulb,  orbr 
structures  correaponding  to  this  higher  up. 

§577.  The  eerebeihr  Irael  (Fig.  l>»i.  Cb)  is,  as  we  have  aeeu.  a  tract  rf 
ascending  degeneration ;  the  degeneration  in  it  makeo  its  appesraxioe  ab:>vp 
the  section  ortheaBfll  of  other  injury  of  the  cord.  It  begins  somewhat  *od- 
denly  at  the  level  of  the  seoml  lumbar  nervp  re^on,  being  abntnt  at  leaal 
as  a  distinct  tract  Iwlow  ;  injury  of  the  conl  at  tbe  level  of  the  latddlc  and 
lower  lumbar  ncn,'c»  lends  to  no  marked  tract  of  degeneration  (though  yn- 
sibly  KfttUred  single  fibres  mnv  H^^nerale).  while  injury  higher  up  does. 
The  tract  lies, n«  we  have  Knid,cfo«-  lo  thvurfaoeof  thacord  in  the  poeterior 
pan  of  the  lateral  column  Jiivt  outcidc  the  crowed  pyramidal  tract,  and  while 
varyiug  snniewhat  in  tha  shape  of  its  oection  from  love)  to  level,  remain) 
thn>ugnout  n  somewhat  narrow  orescentic  patch.  .\t  the  lop  of  the  epiaal 
C'ltil.  it  passes,  as  we  have  Mid.  from  the  lateral  columns  into  tbe  roitifurm 
iKidiee  of  the  bulb,  and  so  to  certain  parts  of  the  cerobellnm. 

When  the  section  or  leuon  is  liniilcd  to  one  side  of  tbe  cord,  tbe  dejpeu- 
erdtton  is  similarly  limited  to  the  sanie  aide,  am!  that  along  il»  whole  course 
up  to  the  cerebsHuin ;  there  u  no  erideno.-  of  any  of  the  fibres  decunatia; 
in  the  cord. 

The  area  nf  the  tract  increases  (Vom  below  upward.  This  has  been  dtUr- 
iuinutl  by  the  emhryological  method,  by  noting  the  appearance  of  tbe 
mwlulla  in  the  ilbres.  as  well  as  bycompanng  the  extent  of  the  degftneraltoa 
following  upDn  a  section  high  up  in  the  cord  witb  that  followin;uc  upau  a 
saciioii  lower  down.  From  this  we  infer  that  the  fibres  corapnsing  the  Intel 
must  start  «uco(--iKiveIy  from  other  parts  of  the  cord  along  its  length — that  it 
to  say,  the  tract  munI  be  fed  by  tibrea  comin;;  from  other  9tnictur<ai  in  the 
Cord.  On  the  other  hand,  it  is  found  that  the  de^nerated  area  following 
upon  a  section  or  injury  dimioishcs  as  it  is  traced  upward  :  when,  for  instaooe. 
u  section  is  made  in  the  mid-thnraeic  re;;ion,  the  area  of  de^eneratiou  in  tbe 
tract  is  greater  immedialely  above  tbe  aeetion  than  it  U  higher  up,  say  io 
the  cervical  region.     F^im  thi«  we  are  led  to  infer  that  though  tbe  tract  it 


TUB   STBL'CTfBE    or    THK   SPINAL   CORD. 


708 


ij  r«d  tlong  it*  ooarM  by  librw  iximin^  from  ollivr  |urt#  of  tbo 

•oiB*  of  ihe  fibres  cnUtring  tho  Irnd,  though  like  (heir  ounipxiiioiiB 
rgoingan  tuoeoding  cWc«>onition,  da  nol  lilcftbom  cotKiauc  in  the  tract 

up  to  tb«  c«n)b«lluin,  Init  p«M  ofl  lo  other  jnm  of  the  eort)  on  their 
ipmud.  Tltis,  houevttr,  in  c<|iiiralent  to  Mvio);  thiU  the  tract  is  not  a 
or  haraogwoous  one,  but  eon«i«ts  of  st  teitst  tiro  wts  of  Abres,  only  one 
licit  t>  continued  on  to  the  cerebellum  nrid  atrietlv  deserves  the  iinme 
enboUar."  It  mny  {>erhii|«  here  be  mentioned  tliat  while  the  flbreo 
ouag  tiw  tnct  are  as  a  n-bnie  coDsfticuously  coarse,  larj;e  fibres,  wiUi 

tber«  are  mingled,  especially  in  the  thoracic  rejtion,  a  number  of  mucli 
flbra ;  but  iboee  apparently  undergo  a  desuemlinK.  not  au  a.Heeiidiag. 
i«ration,  and  do  not  titerefore  really  beIon)(  to  the  traot ;  they  may  be 

which  have  strayed  from  the  pyramidal  tract. 

)  have  a«  yet  no  rerv  clear  evidence  a^  tu  the  origin  of  the  fibres  which 
oae  the  tract.  I'nIiVe  the  case  of  the  median  iioaterior  tract  of  vrbicli 
iv«  next  to  speak,  no  degeneration,  ui  leaat  in  tlie  lumbar  luid  tboraoic 
at,  appeant  in  the  tract  after  sectinu  merely  uf  tlie  roots  of  tlie  nerves; 
xtuce  the  degeneration  the  cord  itself  miiai  lie  injuruil.  Fmin  thi»  w 
mfor  that  tli«  tract  is  not  fed  directly  by  the  fd>r»>  nf  the  [Hwterior  roou. 
obaervera  maintain  that  the  tract  i*  f«l  by  libree  comiuj;  from  the 
llftr  eyUnder  and  [wint  oni'thal  bulh  the  tract  and  the  i-uluinii  begin  at 
UM  lavel  sonMnbot  luddenly  ;  but  the  want  of  pantHclism  biilwvvn  the 

•  of  the  tract  and  that  of  the  cylinder  along  the  knglh  of  the  c^nl,  the 
being  M  we  aaid  cunspicnou*  in  the  thoracic  rcginn  wbilo  the  tract 

ilr  incrcu«ca  upward,  i*  distinctly  op^raeed  to  such  a  view.  From  the 
:l)at  tho  dageneratinn  taking  nlacc  in  it  is  au  mcendiag  one.  it  i:<  sup- 
thnt  the  tract  i»  the  channel  for  RM^rnding,  that  is  (o  ny,  in  a  broad 
.  aflerent  impubos.  And  conaidernblc  iiitereeit  nitncbes  to  the  fact  thai 
impulaea  sfaniild  be  carried,  not  to  the  cerebrum  but  to  the  cerebellum. 
kooiftedge  on  this  point,  however,  is  very  imperfect,  and  what  can  be 
II  the  matter  liad  better  be  said  later  on. 

78.  Tlie  m^ioH  jiorienor  tnct  is  the  other  conspicuous  tract  of  asceud* 
Igeuenition  :  it  also  is  supposed  lo  be  a  ehanucl  fur  ascoiidinK.  afferent 
Gi;  and  this  view  is  rendered  almuit  ivrlatu  by  the  iutimute  relatioiu 

•  timet  to  the  fibrea  of  the  posterior  roots. 

dcidli^  so  far  with  the  trncU  of  degeneration  in  the  siiiiuil  cord  we 
■Iwavt  spoken  of  the  detrenemtion  an  being  th«  ra«u1t  of  le»toiii  of  the 
I  eon)  itaelC  Kxp<:rimeiilsoniuiim3l».how«v6r,and  clinical  cxjwrlcace 
shown  that  division  or  injury-  of  the  fd>rcs  of  the  posterior  root*  is  fob 
I  hv  tracts  of  ttcgenenilion  in  the  spinal  cord,  though  no  damage  wbut- 
may  have  beon  done  lo  tlic  subslanor  of  tlto  cord  ilaelf.     Tb<»e  tract* 

their  amMtruMM  in  the  nie<liuo  jio*tenor  columns,  the  exa<;t  putli  and 
<  of  the  oanatration  differing  wuh  ih<*  dider«Dt  ajHitnl  nerval.  The 
a  of  th«  divtsion  of  different  group*  of  ncrrca  are  >o  instructive  ttial 
ay  dwell  upr>n  them  in  detail. 

the  posterior  ruoti!  of  two  or  thrrc  lumbar  nervea  (on  one  aide)  be 
■d.  an  examination  of  the  conl.  aflvr  an  interval  long  enough  to  allow 
«ralion  lo  be  well  esublisliod.  will  bring  to  light  the  following  feoturea : 
Srided  roote  will  be  found  to  have  degenerated  right  up  to  ibeir  eatnoce 
ibe  oord.  A  aectioo  of  the  cord  oppiuiie  the  entrance  of  the  lowest 
»d  root  will  show  no  de^neration  of  the  cord  beyond  ihst  of  tlie  bundles 
ree  |M«in|[  in.  A  little  higher  up  deigeDeratiou  will  be  obierved  in  the 
mI  poetenor  column  eloee  to  the  poateriur  h'jru :  and  oa  we  ascend  wo 

hat  thin  dt!;teneration  6rat  spreads  over  a  large  pi^rtion  of  the  extertutl 
■iur  column,  and  then  invstled  the  median  poiterior  column;  thede- 


7M 


THE    SI'INAL   CURl). 


C ration  does  not  alfect  the  whole  of  iho  median  paeterior  colimui  l>ii 
»  intact  ft  #ninll  <)or«il  portion,  roughly  triaogular  in  ^iii>c,  at  (V-  u[. 
betvcen  the  tiseiiro  nnd  the  dorsal  surface  of  th«  cord,  aa  well  as  WHDeportun 
of  the  niorv  ventral  part  of  the  column  nearut  the  craj  coiDiiiiasure.  Sliil 
a  litile  higher  tip  we  should  tiiid  that  tlegeoenited  ItbreA  had  dbipp«nil 
from  the  external  iwrtion  of  the  external  poelerior  oolumn  oloM  to  (m  gn* 
matter,  ihongh  still  existing  in  the  nrnre  median  part  of  that  column,  an  ktIi 
aa  in  the  median  [toaterior  coluiuu  to  tlie  extent  juat  indicated,  i^llli  a  liitit 
bi>,'her  up  the  whole  of  the  de};enerHliuu  would  have  dtMppeaned  fran  Ik 
exteraal  posterior  column,  hut  the  tract  of  degc^neraliou  in  tfa«  mediaaf» 
t«rior  oolumn  would  remain,  the  extent  nf  ili-ii^enerniiun  Ivt'iug^  ilependuit on 
the  numtter  «f  nniid  which  had  been  divi<leii.  Liutly,  by  carrving  lbs  wv 
tiona  nlill  higher  un  the  ci>r>l  we  :iJii)iiM  he  iilile  to  tnu-ii  thi*  tract  btla 
ni»liau  poaterior  volumu  nght  up  lu  tlie  bulb,  wberv  it  would  oonwtuo 
imd. 

If  we  divided  son)«  of  the  thoracie  nen-c*  invtmd  of  tbc  lumbar  wo  AnaU 
ohiiiiii  v«Ty  ftimilar  r<9ulti>:  a  dvgi.iivrati(>ii  of  the  external  pnatcrior  oulvmM 
a  litile  above  the  i-ntrar)ce  of  thi?  roolN,  itprcnding  aeroffi  the  column  toiruil 
tiK-  mvdiaii  lint-,  and  wholly  di»ii]i  pea  ring  at  n  certain  height  above,  acott- 
|wnie<)  liy  a  dcgrnciatiou  iif  ii  pnrt  of  the  ra^dinn  poderior  column,  rnafMii, 
fnim  H  little  distance  nbuvp  Ihv  cnlnuieo  of  lite  divided  iien,'(vroote  right  kp 
lo  the  bulb.     This  IiUler  tract  of  dcg^-ncrnlinn  would,  however,  not  (xeiff 
tlir  >«nie  position  us  that  conecijucnt  upon  division  of  tbe  lumbar  nrrvn;  ai 
piji'ition  wouli]  be  morv  ventral,  iioarcr  the  gray  romnii»ure,  and  rvilier  tmn 
Inleral.     Com|iiin'  Fig.  l>^'i,  L),,  whcrv  Ir  indicates  the  degeneration  ilae  In 
section  of  the  lumbar  nerves,  and  dr,  that  of  the  thoracic  nerv«>f^    If  «i 
divided  xomo  of  ihc  cervicul  poslorior  rool;;  we  should  gel  similar  rcanlli. 
with   the  ditlbrcnce  thnt  the  Intel  of  degeneniliou  in  the  DMdiaa  poMMW 
eolunius  would  uecupv  a  {ifaition   iltll  more  veulnil  and  Mill  DMtrekttn! 
(Fig.  182,  C'l  c.r,),  wiiile  if  we  divided  the  »acrul  nervea  tbo  irm-t  .f  '■ 
g«iieration  would  be  duraul  and  median  lo  the  tract  belonging  to  the  luoi  i 
nerves,  luid  would  oc«upj  more  or  le«  of  Uie  triangle  left  below  thiit  tmi 
(Fig.  182,  O,  B.r.j.    The  degenemlioti  it  will  Iw  underaUHxl  »  in  all  raw 
vonhuwl  to  tne  nune  ride  of  tbe  cord  a*  that  <if  tbe  divided  roota.     We  aay 
ndil,  in  order  to  complete  the  story  of  the  eAcct*  of  diviiuoa  of  tlw  yunw'wt 
roots,  thnt  (he  vcetion  leads  to  dcgwcnitioo  of  tbe  marginal  zone  <LuMucr'* 
tract)  but  this  degrnenition  rencliw  for  a  cerlnin  disianc«  only  up  the  enfil 
and  thrn  ilisapjiean'.     It  will  lie  rcmeiiibfirrd  thnt  this  »»nc  is  feil  by  libr«* 
(of  fine  calibre)  belonging  to  tlie  external  or  lateral  bundle  of  the  poatcrio' 
roots. 

These  results  may  bo  interpreted  as  follnna:  The  (jrrent  ranjoriiy  of  the^ 
•Bbrea  of  the  posterior  root,  cut  olf  from  their  ganglion  by  ibe  diriduiS  ' 
degenerate  eeniripelnlly  lowarri  [lie  spinal  cord.     We  have  previously  Mtrs* 
that  many  of  the  tibrea  of  the  root  paaa  into  the  exicmal  posterior  eoluni^ 
and  nin  up  in  ihet  culuuin  for  tome  dtsianc-e.    The  d^neralKMt  obseirad  ic> 
this  column  fur  «ume  distance  aliove  the  enlranoe  of  the  divided  roula  abinrtf 
thnt  ibc  Bbrea  run  lengthways  for  some  diaianee  in  ihia  column,  while  ihtf 
diaapitea ranee  of  the  degeneration  a  little  iijgber  up  similarly  ahuw^  that  the 
fibres  eventuully  leave  tbe  column.    The  appearance  of  d^neration  in  the 
median  puHertor  column  sbowa  that  wnie  of  these  6breB  have  |>n>Bi-d  iniM 
thnt  column  from  ibe  exterual  poateriur  column,  and  lite  eoniinuatiou  of  thai 
degeneration  right  up  lo  ihe  bulb  indicalw  that  Ibese  fibre*   pursue  aa 
unoroken  course  in  that  column  nionv  ihe  whole  lengih  of  the  curd.     Tliv 
area  of  degenerniion.  or  more  exactly  llic  luinibi-r  of  degenerated  fibres  id 
tlie  continued  tract  of  d('gi:ne ration  m  the  median  piMtmor  column  is  much 


TU£  STRUCTCBK  Of  THE  SPIKaL  CORD. 


I 


I 


I 


lew  limn  tlmt  in  (hn  U-miJOrnrj'  or  short  iracl  of  defpiutratHni  in  the  *-x- 
terDKl  jiuricriur  (-olumn.  Thiti  (hi>««  lluit  oumo  only  »(  llio  tibrm  jinwiti^ 
inlo  lliP  extcrnsl  poeleriur  eoliimn  goon  tu  join  thu  median  ponU'rior  column 
an<l  eo  rcKch  the  bitll> ;  lh«  mi  obvioui>]y  Uikv  nnn(li«r  ]Mth,  nnd  nu  hnve 
alreadjr  seeo  reiison  to  Ihink  thnt  amny  of  tbcoi-  end  in  tho  gntj  mutter  of 
the  eonl.  Hence  of  all  tlio  libm  joining  th«  cord  in  n  posterior  root,  while 
soiue,  aud  tlieee  ne  may  mM  are  chiefly  fine  libra,  eoIeriDg  the  gray  mailer 
directly  or  paaung  into  the  posterior  marginal  looe,  anon  make  such  con- 
nections that  ihe  degeneration  due  to  the  section  of  the  root  spreads  no 
flintier,  a  lar^  nauber,  and  these  chielly  conn*  fibres,  Iwfore  they  make  any 
aucli  connection  peas  into  and  occupy  for  some  length  of  ihe  cord  the  exttrunl 
posterior  column.  We  may  here  remark  that  though  these  fibres  are  spreiid 
over  the  gresier  |ierl  of  this  column,  they  do  not  form  the  whole  of  the 
eolumn  ;  Iney  are  mixed  up  with  fHut^  of  a  different  nature  and  origin.  Of 
tbcw  fibrrn  of  the  (Hjsierior  root  which  thus  tun  in  the  txli-nial  ponterior 
Column  uhiie  Mill  dependent  for  [lit.'ir  nutritive  activity  on  the  ganglion  of 
tbo  root,  Mime,  iodeea  the  greatir  jmrt,  Imve  the  traot  and  make  such  con- 
OMtioni)  in  the  gray  rontler,  that  tlieir  dogt-ntTfltion  ceiutcx :  otlierH,  forming 
the  sniMller  p«rl.  piiMi  into  the  mniian  |Hi)>torior  column,  and  taking  up  > 
definite  povitinn  in  tluil  c^ilunm  puniie  an  uuhrokcn  courM;  to  the  hull). 

All  imt  filiri-s.  iherclore.  "f  tlie  putterior  rootn  do  n<it  en<i  in  the  gray 
matter  soon  iiRer  their  entrance  into  th«  oonl.  A  reprvM:ntniivoof  each  root 
is  carrical  right  up  to  th<^  bulb  by  means  of  the  median  posterior  column ;  of 
the  axis-cyhndcr*  which  leave  the  ganglion  on  the  root,  a  certain  relaiivelv 
small  number  punne  an  unbroken  coiirw  for  some  litllc  distance  through 
the  external  posterior  column,  mul  for  the  rc»t  of  their  way  through  iTie 
ntedian  poeterior  column,  along  the  whole  lougth  of  the  cord  above  Ihe 
entrance  of  the  root  until  ihey  lind  nn  ending  in  the  gray  matter  of  the  bulb. 
Further,  each  spinal  nerve  has  this  repreeenlalive  of  its  posterior  root  placed 
in  a  delinile  poeili<;n  in  ihe  |Hj«lerior  median  column,  the  arrangement  Imiog 
NHcli  aa  shown  in  Fig.  14:^,  ihal  the  lower  (sacral)  nerves  lind  tneir  place  in 
the  more  dortal  and  median  part  of  ihe  column,  while  the  nerves  abore  are 
•nccCMively  placed  in  pi«tlti)ii«  more  ai>d  more  ventral  and  external. 

Aa  ftr  as  our  knowledge  goes  at  present  we  are  led  to  believe  that  thia 
median  [KMierior  tract  is  very  largely  made  up  of  fibres  having  thi^  origin. 
It  allunls  a  cliaunel  by  which  atli^rent  inapiil^ie^  are  earned  straight  up  the 
cord  from  the  nt^rve-trunk  without  making  eonneclioni)  on  the  way.  Wc 
may  rrpi-at  that  the  path  in  eoufiued  t»  the  ftame  tide  of  the  cord  along  its 
whole  length  ;  [here  \a  no  crosiiing  over  to  thr  oihur  side. 

In  tlw  above  description  we  have  spoken  only  of  the  rewiltit  following  ncc- 
tJoo  of  itu)  Dovtrrior  riMjta  oulfide  the  cord ;  hut  it  will  be  undenttood  that 
Minilar  muita  follow  upon  jwdion  or  of  injury  to  or  disoBac  of  the  cor^t  itself 
•flbcting  tbo  poeterior  oiluniiix  or  the  bundltw  of  tho  roota  n«  they  enter  the 
cord.  When  such  ■  Ifltion  occunt  ihervi  may  1k^  ii)»tcrTi-il  in  the  region  of  the 
cord  above  the  lecion  a  degeneration  »f  the  external  p'Mlerior  column,  reach- 
ing some  little  distance  up,  nod  a  more  limited  dngeneralioo  of  a  part  of  the 
median  p^islciior  ciliimn  stretching  right  uii  to  the  bulb.  The  pneitixn  and 
fdrin  ul  the  trael  of  the  degeneration  in  the  inclinn  prittcrior  column  will 
(lv|i«od  on  the  level  of  the  lesion  along  the  Ecnglh  of  the  cord,  according  as 
it  inlcrruplfi  iho  ascending  repTcsentAlives  ol  the  sncral  nerves  only,  or  of 
the  Ininbar  and  Mcrnl  nervei^.  or  of  the  dorsal  amt  cervical  ncrveo  as  well. 
A  complete  section  or  hemi'^et-lton  of  tli«  eort  will  produce  results  corre- 
eponding  to  the  division  ua  both  sides  or  ou  one  side  of  all  the  nervee  below 
the  wctwu. 

We  may  add  that  while,  according  lo  some  observers,  the  Mraai)  of  Rbm 

<:. 


708 


lirl'iiiK<"R  'o  a  particular  root  or  group  of  rtM>H  hnviii;;  otice  lak«i  liiTl 
|Hjaitii>ii  in  the  luedian  p<:«terH>r  coIuud  reoiatos  uiicluiii^t  until  it  rCMlio 
l)ie  bulb;  Mccording  to  otben  it  duninUKe  iu  ares,  soine  of  ils  tibran  iMkiof 
viiDiieciiuDs  in  the  cord  itself. 

M79.  Tlie  anltTo-taUral  lucrudinp  Irael  (Fig.  IHL*.  use.  a.  I.)  I*  liw  ntll 
kunwit  than  either  of  Ibe  two  (OeccdiDR :  it  a  iilw>  more  difliiM,  thnt  i*  tu 
any.  tlie  filirM  underpins  degeoeraliuii  are  more  InritvJv  iniwd  iriili  tlbm 
of  II  tllflereDt  uature  ana  ori([ia.  It  HpfMraru  to  extend  (lnwii  tW  rord  ini 
lower  leri-1  than  ilie  cerebellar  tract,  but  ii«  loKer  limit  liMOnlTMbacD 
aocural«lj  ilttlennined.  .Since  the  defcuiieralion  Inking  iilncc  In  it  ii  n 
MoMHiing  une,  it  hua  been  inferred  lliat  it  tervt-s  an  thf  ]i»th  fur  aflcrtot 
and  indeed  for  MMivory  im|>ulMA.  DeigennrHtion  in  it  io  mvu  only  ftHct 
DVCtion  or  injury  iif  the  t>uhxliui(-e  uf  tbe  eonJ  ItJoir.  mil  iilU-^r  divisiun  i»r  ikr 
pMterinr  roat«.  If.  ihun,  it  it  to  Iw  rvgardod  lu  ii  channel  of  aftrtnl 
ira|Mikn  pawing  into  it  fruni  ihu  jxwterior  roolt,  tboM  ImpiiIsM  inual  paa 
into  it  along  th^iM^  filiris  of  the  ]>(>«tcrioi'  root  which  fin<1  mvoiidnrr  UdjiIik 
«-ntrw  ill  Bomi-  purl  <\l'  ihi^  gray  miiU«r:  in  this  mjMx-t  llii«  trart  reMOibla 
ibo  coreWbr  tract,  ami  dilfen  from  tlir  nuilian  |>wtvrior  trai-t.  The  luttf 
i<  tiw  direct  continimlion  up  the  cord  lo  iliv  hulb  of  siirb  (ihn-»  cu  are  tiil 
Uiuting  lor  their  iiulrilivr  aclix-tty  to  (he  cells  of  the  ({■"■K'i""  >»>  ihl 
(XMtorior  raol ;  the  Hhm  of  iMh  the  former  lni»t  for  their  nuirilive  aciirilT 
to  some  part  of  iIk  gray  mntlcr  of  the  oord,  and  prwiiniiibly  tn  iht^  Dnrvt- 
oella  of  that  gray  matter.  A  further  rcMtmblance  mtween  tbe  atiteru-laioiJ 
ascending  iind  cerebellar  tracts  must  be  admitted,  if  future  reaenrchoi  n* 
firm  the  opinion  of  those  who  bold  that  tbe  former  like  tlie  Uilter,  nt  tlie  itf 
of  the  ooni,  paiffl  along  iIm  rwtiform  body  to  tbe  cereliellum.  IikIci^,  uiiikr 
Mich  a  view  it  would  appear  probable  that  the  autero-laleral  tract  i»  •iiiH>lt 
n  more  ditHiae  and  outlying'  part  of  tbe  cerebellar  tract. 

^  MO.  We  may  now  brietly  jiaeh  in  review,  somewhat  as  fullowi,  the  rhie' 
facta  which  we  nave  tearued  couceming  the  structure  df  ihn  spinal  rant 
aliraya  keeping  in  view  ibeir  physiological  meaning. 

Tbe  ini|Hinam  leatiire  of  the  spinal  cord  ja  the  pr»ence  of  what  we  bare 
culled  "gray  matter,"  and  all  our  Kmiwledse  goealoaliou'  that  ibe  ini|urtatil 
|Hiwcn  of  tbe  Hpinal  <i>r<l,  by  which  it  dimra  ftxMU  a  thick  niutliplc  ngnr. 
and  hy  virtue  of  which  ne  ^(iL-ak  of  it  ax  a  i>ervou*  centre  ur  oorics  of  cMUm 
are  in  iH>niv  nay  or  nthi-r  aiMicialed  nilli  thia  gray  matter. 

Wilb  this  gray  iiiallor  the  fibns  of  tbe  K]>inal  iivrvw  nr«  cobtioclttL  Ha 
graater  part  of  the  librea  of  tbe  aiilorior  root  certainly  end  in  or  mthtf  uIh 
origin  fnuii  the  gray  matter  cloac  to  the  attachment  of  the  root,  aod  tlw  ml 
awtl  pniliulily  join  the  grmv  matter  at  no  great  dkuivco^  The  fibres  of  tb* 
poatcrior  root  nin,  aa  we  nave  sovn.  Jbr  sonrn  little  dUtAooe  in  tbewbiu 
matter,  but  if  wo  except  ibc  «pcrial  Imndlc  which  ruiu  in  tlie  mediu  p* 
iM^or  ir»<-l  right  up  too  cord  to  Ihc  twlb  witliout  joining  the  sfintl  giV 
nutlirr  nl  all,  wc  may  aay  that  (be  Ghn»  of  tbe  poelerior  root  auo  join  m 
gray  matter  not  far  from  tliu  atiiichmcnt  of  the  rout. 

Morphological  rcasont  lead  us,  as  ire  have  seen,  to  regard  the  spinal  oni 
ns  a  kHck  of  segments,  each  segment  oomeponding  to  a  |iair  of  oerra; 
nml  even  in  the  spinal  cord  of  i»un  we  may  revcqpiite  a  sei^nwotal  fvmoi- 
Work,  iibM-uivd  though  thia  is  by  fusion  and  overiaid  by  the  aeveral  iiioun>* 
sural  tracts.  Each  segnwot  of  this  groundwork  we  may  concetTc  ufiD* 
central  mass  of  gray  matter,  eonoectea  on  each  side  with  an  ui)l«Ti»T  iM  * 
jMeterior  root,  thus  constituting  a  segmental  nervous  meclianium  npMf'f 
carryiug  out  certain  fuiietiuns. 

8ueh  a  socinent  ha^  bc^en  compared  to  a  ganglion,  but  it  dillV'r>  mrikinj:'; 
from  a  gaagliou,  whether  of  the  posterior  root  or  of  ilie  tpbueliuic  snMiai 


TlIK    STBL'CTIIIE    OF   THE    8P1XAI.   lOBD. 


707 


Ui'turo  iii>il  in   function.     A  ;|.'niij{IIi>ii  uiiil  the  K>^ir  innllur  uf  ■ 
Dent  ImIIi  cixilain  niT^'e-i'c^llif,  uiitt  kh  far  riTK'iiiMu  i-iicli  ulher;  but 


jhlniicii  fur  llii 


niuiil  pari  cikIf.  Iiib  gniiifluMi  tbo  cunxUtitcnt 
liT»-<-rll  i«  a  >lrvi-liii)m(.-iil  of  tin;  nsiix-rlinilcr  gf  «  filirv  iiilo  u  iiiic1e«to(t 
|ll4xMly  which  lid  on  ibu  oourae  of  the  librr,  and  miiT,  lU  in  n  »plniK-)inic 
KagUno.  Ix)  plnoed  jm^t  w-Iirro  one  fibre  ilivliliv  into  Iwo  t>r  morv.  ^Vfi  have 
|nr  ttrkiiiDO  that  tbp  cell,  ibac  i>  I<>  mv,  the  dik-Icur  wilb  the  ndjiicciil  wll 
Ifaitaiioc.  Bxcrcisn  rh  it»i)»r(iiiii  itiHucnco  on  tbo  nutrition,  mil)  "i  on  th« 
kactional  M-livity  of  llu-  nrrvc  libra,  it  net*,  ii»  we  Iikvo  Mx-ti,  iu>  n  "  trophic 
tnira."  There  iire  «lso  rcnwciB  fur  thinking  tbitt  the  mil  aubstHiice  w  mure 
Kulive,  more  rendilv  retpoiijive  to  chiiDgist  iii  lU  circuuiitiuircs  than  is  tlie 
Ks^yliittler  at  ramo  dut4iiii.i'  fruni  the  cell.  But  wg  hnve  nu  satiifactory 
riiteno*  that  ibe  cell  can  automat icallv  nrii^iaale  Dervous  iiDpiiU^s  in  it«elf 
t  the  itutcuRw  of  its  ovru  inlrinftie  ohaneas.  Nar  have  ne  any  evideaoe 
tst  the  cell  can  exert  any  marked  transJorminK  [lower  over  ihe  impulsefl 
jHoiDt;  nixdi!  the  fibre :  the  iupulan  wfaieb  travel  away  from  the  t-ell  do  not 
ppaar  lo  diUVr  markctlly  from  ttune  which  travel  toward  it.  The  teverul 
Mteooen  in  which  there  aeewed  (u  be  evidence  that  eplsiichiiii.-  ganglia  ooted 
I  c«ntr«i  either  of  reflex  or  of  automatic  itctiuD.  ha\'e,  aa  we  have  Been, 
■vkco  JowD ;  aiid  it  a  not  even  suggcated  that  the  {{suglia  of  the  posterior 
Hl»  powwt  any  such  powers.  Th«  gray  matter  of  the  spinal  cord,  on  tlie 
Ihirr  IiHiid.  an  nii  \m\f  alrendy  »eeii, and  a«  we  xbatl  nee  more  in  detail,  in 

?wcinlly  charactcHwd  by  the  [wMBiwiion  of  reflex  ami  automatic  a*  well  as 
other' poircn. 

In  tiructute,  moreover,  nuch  a  *|)iiial  «e;|i:nieni  diffiuv  Htrikingly  from  a 
knglion  and  cxbtbitx  ft-alurci  iinKn<twn  !n  icanglia.  In  a  ganglion  the 
trve  fibrvK  may  divide,  and  in  n  «mall  [icripbcral  )rjn£lion  tbc  diviHion  may 
ire  ri«c  to  very  dulicatv  fibriU;  but  tbi;  fibro  or  fibriu  rtuulting  from  the 
tviaion  leave  the  ganglion  to  follow  their  appropriile  coureea;  the  diriiioo 
trirca  for  dimniuD  only.  In  iho  vpiaal  mrd,  on  the  olhor  band,  both 
Bereul  and  alKrefit  (ibra  divide  in  such  a  way  thai  their  diviaions  are  loot 
)  view  in  the  gray  mailer;  division  here  eeems  to  serve  the  purpose  of 
nioo.  I'he  efft^rent  fibres  of  the  anterior  rout  may  be  traoed  nack  aa  a 
rocew  of  a  cell  in  tlie  anienor  horn.  That  ci-ll  givei  utl'  other  procesMB, 
Ut  iio  one  of  these  juxmimms  is  contiiiued  on  as  an  asi^-cylioder  proc«a5 
Crcu-hing  acron  the  gray  tnatier  until  it  beooues  a  tibre  of  the  |)ofierior 
bot,or  ua  anything  like  auch  an  axis-cylinder  proeeas.  Ou  (be  contrary, 
tl  the  prucMHS,  exc«pt  the  axiacylindcr  prociMi,  divide  into  branches,  and 
bpiiiar  to  eml  in  nervoun  libriU  lust  t^i  view  in  the  gray  mailer.  Cunireraely, 
Un^  our  knonlislgc  of  ihc  juncii'iu  of  the  |K>tUirior  Dbnu  with  the  gray 

EiUcr  in  much  more  imperfecl  than  that  of  the  junction  of  the  anterior 
HM,  what  wo  do  kooir  leadd  tu  to  believr  tliai  the  tibrc«  of  tlie  puaierior 
Dot,  cithvr  by  the  meilintion  of  cellit,  or  by  direct  division  of  thi-  axiii- 
jrlindvr  wilhtxit  lht<  mciliation  of  cidlit,  nimilarly  break  up  into  fibrils  and 
re  nimilnriy  \tml  in  the  gray  mattiT.  All  the  evidence  goes  to  (how  that 
he  antrrior  and  {fMU-rior  rooii  arv  fiinclionvlly  continuous;  this  functional 
piitinuiiy  i^  howovcr,  eflectwl  not  by  a  gruae  cmntinuily  of  axi*-cylind«H, 
Kit  in  a  peculiar  manner  through  tite  diviiton  of  brancfae«  of  norro-cvlls  or 
f  axi»-ryHndorf>  into  the  nervoux  lanicle  which  forms  such  a  spoctnl  fvatur« 
t  the  gray  matter  nf  the  t  <<i'<l.  We  may,  perhaps,  venture  tn  rvganl  the 
;ray  matter  of  the  Migmvnial  gr<  Mind  work,  of  which  wa  an?  noir  nlonc  speak- 
Bjt,  ai  riinatiluliii;;  a  nervoii"  nriiwiirk  i.ir  web.  fonue^l  certainly  in  part  bj 
be  rapidly  dividing  branchi-«  of  niirvc-Lvll»,  and  prob.tbly  in  p»rl  by  iha 
tivkNOUH  of  directly  dividing  ni-rve  fibres. 
Iji  any  ordinary  section  of  tlie  spinal  ouni  the  gray  matMtr  presents  to 


708 


THB   8PINAT(   CORP. 


groundwork.     To 


(I. 


..f' 


view  miicli  raontbiui  ilr 

»lnicttir 
nr*'  cUimt'd  nov  In  hr  iicnro(,'li«.  ni'w  to  lip  nervou*  in  imUirr,  Ihr  en\ 
mntwr  in  every  wi-tion  ehuns  minicroiis  ili»liiict  ncrvt  &\>m  rminingiiiii 
various  dirpctions ;  of  thttc  fibres  n  Cvm  arc  ordiDBir  modtillmK-d  lil>nv.  mm 
are  non-iDtdidlfileit  fibrcc,  ihnt  is  to  fuy,  nni  niiKnl  ■xw-rvlimlcn'.  mhi, 
Othen,  and  these  the  more  numerous,  nre  lh«  peculiur  mcdiiilaird  fibm  >\f 
email  diameter  spoken  of  in  i;  'iSi.  A  Inrj^e  Diimb«r  of  tlie»e  lihm.  in-iM 
all  the  lar);«r  ones,  ltioii;;h  tliey  go  to  make  up  what  ire  call  gray  nalUr, 
are  not  continuous  with,  and  do  not  belong  to,  the  i;roai)dworK  or  aerVMR' 
web,  at  all  evenis  do  not  form  part  of  the  grounduork  wen  in  the  iw 
aeclioD  as  iheni»elveG.  Tliey  are  itimply  fibreia  iraversiu^,'  the  ^roundxisk, iu 
spaces  of  the  neuro(;lia  bed,  on  their  way  up  or  down  (he  cenl.  or  acr<w  ihf 
cord  from  one  part  to  another.  It  may  be  that  some  of  the  finer  ncdaliiKd 
fibres  do  really  enter  into  the  ^roun<lwork,  and  so  eonirilKite  to  ibe  nemoi 
«eb;  but  our  knowledge  is  too  imperfect  to  afford  a  clear  decision  on  lUi 
[loint.  Our  inability  to  define  its  exacrl  limits  need  not,  bo«re\-er,  pitroit 
our  reeoguiKJn^  the-  existence  of  the  fzioundwork. 

The  |iTonjini-nci.-  in  this  groundwork  of  th<-  hirgcr  »cr^-«-cellt  ha*  ltd  t* 
the  CQDreiitinn  llint  the  powers  of  the  njiinal  lu-ginent  are  exerciaed  by  thew 
Derrc-cellii  l<>  ihe  exclusion  of  Ihv  other  elenieni*  of  th«  nrrvuua  neli.  fhil 
such  a  view  ba»  not  linen  adtsjuatcly  prnvrd.  What  ue  do  know  i*  that  llir 
nuclei  and  fell  -  hud  itii  of  the  (.■elln  of  the  nnlcrior  horn  cxcrctK*  an  itnpotuni 
influeoco  on  lliv  nutrition  of  the  fihron  nf  the  anterior  rnoi  which  pravnl 
from  tbcjn,  and  poivibly  »\m  influt-jiw  ibc  uutrilton  of  the  other  Imatba 
of  the  cell*  forming  part  of  the  gnnindwnrk  ;  and  tbcw  cclli'  are  prnhiUr 
«>  eon«picuoii»  n  fniturr-  of  every  secliun  of  the  xpinal  n>rd  hecaiue  of  Iw 
imporluut  Uisk  intrusted  to  tbeni  of  mainlaininf;  in  due  order  the  nntrilNO 
of  the  long  atreleh  of  motor  fibres  reaching  from  them  to  the  routcabt 
fibres  or  other  iieriphcral  or^na.  The  Rlires  of  the  posterior  r'intutsM 
so  obviounly  ennnci-ted  with  the  conspleuous  cells  of  the  gray  niador:  in- 
deed, as  we  have  said,  it  may  be  douliied,  though  the  view  ta  mainiaine4  ^ 
some,  whether  any  cell  intervenes  lo  secure  the  coiilinuily  of  a  pwlcriM 
fibre  with  the  groundwork,  a  division  of  the  axis-cylinder  wrvini;  iliii  [M^ 

C;  and  this  Ik-chuie^  inielli^ible  when  we  Iiesir  iu  mind  that  Ihe  pMl«n<f 
«  are  governed  as  lar  as  tbeir  nuiriiioa  in  concerned  hy  the  uervtcA 
itf  tlic  Kungliiin  on  the  posterior  root,  which  ought  pmhahly  to  be  KoBttdmd 
as  much  a  part  of  tlie  spinal  cuni  as  the  cell-  >d*  the  an(eri<ir  bom. 
ncrve-ccU  of  the  gim^lion   is  adc'iuate  to  secure  the  due  nuiriliounf 
nerve  fibre  until  it  joins  the  groundwork,  aiid  probably  hei\m  la  tnr' 
the  nutrition  of  the  groumlwork  iiwlf. 

Hcnoc  we  may  )X-rbapi>,  until  fresh  GVidcnco-  to  ihe  contrary  Is 
fbrwanl,  incline  to  the  view  that  the  powers  of  th«  gray  matter  do 
depend  on  the  consjiifiious  eclls  alone  or  even  chieflv.  bul  on  the  peca'.— j 
moli-culur  ronniitution  am)  naluro  of  the  whole  grouDawork.  The  nuclei  'r 
the  cell*  of  ihe  nutcrior  hum  with  the  cell  substance  ndjaccnt  to  each  a  *^ 
the  cells  of  the  ganj^lia  on  the  jMirterior  root  probably  govern  tbe  nutrilit^ 
and  *a  the  functional  activity  of  the  groundwork  as  well  as  of  the  tasui.  ' 
ami  entering  fibres  ;  bul  there  apjie'ars  to  be  w  yet  no  coiiTincing  evldet^ 
of  anyolh<r  [H-inlinr  powers  conlintd  to  the  cells  and  iilisent  from  ot^M 
parts  of  the  groiiodwork.  We  may  add  that,  in  accordance  with  this  vi^^ 
the  other  celts  of  the  gray  mailer,  such  oa  those  of  (be  vefieular  eylim^S 
are  to  be  regarded  as  of  itnportnnee  for  governing  the  nulrilioo  of  fibr 
comniiasiirnl  and  others,  starling  from  the  spinal  segment,  and  of  the 
ol'  ihe  gruundKork  from  which  by  their  mediation  the  fibres  aun. 


ItJCTtTRB  or   THE  SPI.N'AL 


709 


uiniiii;  th'-  fiia«li«iu  or  lli«  grouuilwnrk  of  itic  •egmcnl  or  of 
iviay:  iiujt\il*c*  from  iU 

I  581.  Tlic  acgmental  gmiinilirnrk  of  grny  malU-r  Wlonirins  to  cat'h  pair 
of  •iniinl  nvrva*  ia  «o  fuim]  with  that  of  nil  tlic  mhcr  paira  lu  to  form  along 
ill*  whoir  l«ngtb  of  tho  cor<l  n  mnv  of  gmr  matlor  which  iippeAr«,  uniler 
ia  vircimMMDocaatnllcvonu.  tobevoDtinuoui  in  the  mum  that  impuIsM 
paM  in  all  iliroirtioiis  along  it.  But  tmch  spiniil  Mgmeot  l«  in  tidJitioo 
i>Ct«H  by  means  of  Irttrtf  of  irhit«  matter  wilh  parts  more  or  Ifaa  diaUiDt. 
Tb«  oroued  prramiilnl  tract  i«  such  ■  longitiidiDal  comitiiuiiml  tract,  con- 
uactiog  apparently  each  epionl  eegmeot  In  succewon  with  a  certnin  p<irt  of 
ibo  (■ortex  of  tho  oorebnnu.  Wo  have  r«uon  to  think,  as  we  ah»ll  «ee  later 
in,  tbat  iinplliMB  descending  this  or  that  libra  or  tfroitp  uf  fibres  of  this  tract 
i^T«  rise  to  the  iaaue  of  nii>lor  impulses  along  this  or  that  fibre  or  u^oup  of 
fibra  of  an  anterior  rooi.  We  do  uot  al  preKut  know  what  is  toe  exact 
manner  br  wliieh  the  libr«  iu  the  pyramidal  tract  is  eonnected  wilh  the  fibre 
of  iIm>  anterior  root.  [|  seems  certwu,  however,  that  the  conneotioii  is  not 
■u  the  l<>rni  of  a  fibre  isolated  fVom  the  rest  of  (he  gray  uiatt«r,  continuing, 
Hu  to  speak,  Uie  pyraiiiiditl  lihre  into  a  cell  »f  Ihe  anterior  horn  nhtnce  the 
fibr«  of  llie  aut«riur  mot  isiiic*.  Moat  prubal>ly  the  pyramidal  fibre  makes 
eoDiMclious  with  the  secmental  groundwork  spoken  of  above,  whether  with 
or  without  the  intervention  of  a  cell  ire  cannot  at  preaent  tetL  The  direct 
pyramlfhil  tract  is  a  Iik<:  tract  of  lewt  (extent  downward,  and  thu  Uw  known 
anbero-lnteral  dcstwnding  Iruct  i*  probably  of  a  similar  nature. 

Tbtr  ccrvltellar  and  aiilrro-]at«nil  uicwnding  trai-lH  arc  in  like  manner  to 
he  niganl«xl  a«  longitudinal  commiwures  between  the  Kuocttwtvc  spinal  tta- 
■MOt  Ddow  and  sonii;  [MrC  of  the  brain  nborc  Wo  have  nM«on  to  think 
tlut  tbwe  tract*  coiivev  upward  impuLseaof  a  nature  which  may  ho  called 
tflbrenl,  and  arv.  tlicreAire,  in  8»nie  way  probably  conaecbed  witb  the  pM- 
terior  roots^  We  do  uot  know  ns  yet  the  exact  nature  of  the  conneotion ; 
but  pr»bably  in  those  caMS  also  the  couimisstirat  fibres  are  umt«d  not  directly 
(Olbe  jMslerior  fibres,  but  iudirei-lly  by  means  of  the  segmental  groundwork. 
And  since  these  iracls  do  nut  de^nerate  after  section  of  the  poaterior  roots, 
but  only  afWr  section  or  other  lesion  of  the  cord  itself,  we  may  infer  ibat 
their  junction  with  the  grotmdwork  is  eltect«d  bv  menn^  of  trophic  cells,  by 
^fcns  of  some  or  other  of  the  odis  ipoken  of  a  little  while  before. 
^Bhe  median  posterior  tract  seems  to  be  a  commissural  tract  of  a  nature 
dUl^rent  from  any  of  the  above.  Through  it  a  cettaiu  part  of  each  posterior 
not  is  brought  into  oonocolion.  not  with  its  own  spinal  segment,  but  witb  Ihe 
bulb  above,  and  aa  nJih  the  hrain.  which  tbiu  receive!  dircot  repreaeotji lives 
of  cacb  attereut  spinal  nerve.  If,  however,  a*  aomu  maintain,  the  bundle  in 
this  tract  starting  from  a  Hpinal  nerve  below  dimiuixho*  m>  it  proceab  upward, 
tbrowing  off  fibrciii  tn  ]>aw  vl«rwbert),  though  always  carrying  soini;  Kbrws 
right  Up  to  tlw  bulb,  wc  must  add  to  the  nbiivc  toe  further  view  that  this 
tract  connect*  aU>  each  po«lcrior  root)  iwt  witb  its  own  segment,  but  with 
other  nioru  or  Ii^At  ilUtanl  twemcnts. 

$  66S.  .\ll  the  cvidenoo  which  we  posMss  goes  to  sbow  that  each  strand  of 
Mch  of  th«M  tract*  nin«  itolnt^-d.  that  is  to  say,  makes  no  connections  with 
adj<Hniii'_-  •tructurv  at  any  [Mirt  of  its  course,  from  it«  beginning  or  end  in  the 
brain  and  Its  end  or  beginning  in  its  appropriate  spinal  segment,  or  in  the  case 
uf  the  RUHlian  poslmor  tract  from  its  bcginoiog  la  the  gaaglioD  of  a  poae> 
rior  rout  and  its  end  in  the  bulb  or  in  some  tUitailt  spinal  segQent.  In  the 
eroesed  pynuaidal  tract,  for  instanoe,  we  have  reason  to  think  that  one  or 
more  fibres  run  a  quite  unbn>kei)  and  isolated  course  from  the  cortex  of  the 
cerebrum  thnkuj^h  Tariuus  paru  of  the  brain,  •]«■(  the  wb»le  length  of  tho 
laorrl  until  they  reach  lite  lowermust  spiual  aecniHilal  meohanijm.    These 


rra 


TBK    Srt^AL    CUR0. 


i 

ii|hW    I 


Ineli  mem  n  m  waj  tn  oaaaect  («e  Ngmtninl  nirRhinutn  wllb  anpthtr. 
TW  NfBcoul  mBAmaaama  a«c  bowvrer,  coanvcteil  tn^ilifr ;  umI  Uiv  n<i- 
— ai»«»  betwem  ibeai  «■»  to  b«  of  twn  klwU  In  the  firvt  t*'"*^^-  ■>-*  *' 
have  alf^df  miggntlM,  tbe  wfBtnital  pitcai  of  gny  uinllrr  mro  *i>  fiuri 
tngBtkcr  w  to  fi.mi  «lut  apricar*  Cu  b«  •  eootinuitv  of  gray  mntt'T  fn<tn  'iix 
MM  «f  ibe  onni  to  tike  pUkt.  TboQgb  «*  ainnot  ■rtuitllr  truck  vur  ait 
UHoloficailr  UirM^b,  mud  mrc  «UII  Um  »wu*  of  iIh'  i>livi>t<>I(i^icul  nklutr  if 
tfc*  kbjrinu  of  BfiTr>oeik,  ibn*,  ftod  fibiili  «')ii<'h  nm^r  up  what  wn  Imw 
ealWd  Um  giwindwock.  ««  msj  wilh  eoMkkrulili-  prolmlnlily  iiwiiiuc  thu 
tbt  |MMan  of  Bvrrotw  inpabn  tHoag  it  ia  dMrniiiiiitl  lu  much  by 
tUtJMi  of  UM  iBBWml  M  br  iti ualMHieaJ  dicp'v'ilioii :  ibnl,  for  in 
rMtncliow  to  Uw  Bow  0/  sa  iapabc  u«  brought  nhwii  much  nun* 
qncad;  bjr  tlw  reftiMl  of  tk*  sideeata  of  imrvnus  m»tier  to  take  m 
nabeaJordiHariMtnce  wfaidi iatlMMWflce  of  the  impiilEc;  ihiit  ie  to 
Mttleeolar  Tuimiicti  iIms  by  utaal  bmks  of  ooniinuiiy  in  tbtr 
ntaiter.  Indeed,  wc  ksre  stme  ruoim  for  thinkinf;  iliai  fn'tunl  ^tnn-igi 
cuntinaity  of  DemKn  RMternl  ii  not  cvmtial  lu  funi-tional  coiiiiunity ;  il 
s  Dcrre  fibril,  for  initanee.  nuij  pndocv  iu  due  et)«ft  on  another  xtvt\r  iiW 
or  OR  a  nerv«-ceU,  if  suffimntly  ia  contact  Kith  it,  tltuugh  th«  mien. 
fai)»  l»  drmoaMnte  actaal  runlinuity. 

But  bnidrs  tbe  pay  tualter  there  are  areas  of  white  matter  whirh  il^ 
bcUiog  rithiT  to  tW  n«'nre  roots  aa  tkeee  are  makini;  their  wnv  into  tha 
Buttfr,  or  to  anv  of  the  Iracti  vhieh  we  have  meiilioiHM).     Thn^t  ouni, 
the  strand*  of  tihrr*  whtrh  do  n»t  undergo  eitliur  BHoc-ntling  or  ilmcvudini; 
dtgeiH-falioD  wbvn  part*  of  tbi-  *ptnal  cord  are  injiin-il  nr  diH-jwiil,    Tht  am 
of  white  mailer  )«ft  when  nil  the  vnriouN  tractn  nf  aorcndiiig  iind  dcM-rndiiif 
dtgenerattoo  detaiM  alxirearv  titkcn  nut.  neemi,  at  nil  ovcnts  in  thr  [' 
parta  of  the  cord  (Fig.  IH2),  rdaiivcly  i^mall,  aiw)  ftitiiro  obaervaii'in- 
cvinlinue  tlill  further  to  r«daco  il ;  but  it  mixt  Ik- n-momlM-rrd  lliiil  noiw.l 
tlie  above-na«uiioD^I  tracts  are  "pure:"  they  arc  ill)   more  (ir  \r»  mixi^t  up, 
aid  MMne  largely  mixed  op,  with  Sbrcc  nhich  do  not  d('i,'i-iiiTati'.    I'ut 
Inowled^  ia  at  present  too  scanty  to  nilow  us  to  make  any  ^tnieini-ot  a>ih 
confidence  conceminK  the   flinction  either  of  the   Hbres  forming  tlienlwr 
natter  not  yet  marked  out  into  tracts,  or  cf  the  Bbres  scattered  amixig  t^ 
acknowledged  tracla.     I)ut  we  iniiy,  at  all  events  provtsiooally,  aiuin*  thai 
IbtMi  fibres  serve  in  the  main  aa  ooiomtMures  ronnectio^  tbe  auceemn^- 
mental  medianisuis  nith  eui:h  other:  we  may  eondnde  that  changes  taklag 
place  in  one  vrgmental  merhauiitm  can  by  means  of  titew  fibres  produM  ti*- 
relnird  chnuge*  in  M>mc  ixher  dtMant  segmental  mevhauisio,  without  cslint 
into  action  any  of  ilir  gmy  mnttvr  of  the  iuterveniugsegmenliil  mn-hanMii^ 

11ie  commi>«tin-9>  wbii-U  no  may  MipiKiw  to  be  iIium  furniKbi-il  bv  xUtr 
Dinder  ■»<  JoiigiludiMsl  comtnisnim  ounnoctins:  tbe  M-^oH-ntnl  nKcbaui^* 
of  ili«  «tnie  Intend  hnlf  of  ih*  aninal  oonl  with  each  other.  A  irantnM 
cnnedi'in  brtw<tn  the  l«o  Inleral  bii1vt9>  U  afliirded  in  »i.tiK!  meiiHUfvtf  1^ 
anterior  while  i-Dmmi«urL'.  We  nhilll  •«.  howevi'r.  Inter  on.  rrawot  Ii* 
Ihiukin);  thnl  many  impulses  besldw  thfln  pSMing  idong  the  iini«i> 
mifBUie  cross  from  one  udoof  the  eottl  to  ibooth'T:  luid  iheef,  w' 
pass  nli'O},'  dipiinct  libre»  or  along  ibe  pi'n<'rnl  t,'roun<lwork.  mux  tn 
ttif  gray  inftller  of  iW  irthmiis  forming  tlio  nnlcrior  and  poettrior  gray  n« 
mlMUrea. 

Thus,  as  far  as  w«  can  see  at  present.  tli«  ^pinnl  eord  oonslsi^  of  a  teno 
•rgBM-ntnl  mefltnni»ma  with  tlieir  respeclire  nlTcretK  ami  efferent  rnoUC 
gray  matter  of  Ihe  several  segnvenis  l>eing  continuous  nlong  the  corn)i 
encephalic  tiee  «f  white  matter  iKtueen  the  several  segments  and  lbs  br 


» 


THE    REFLKX    ACTIONS   or   TUK    SPINAl.   fOBD.  711 

of  liingituduial  oommiMura)  Uncts  ctuiuMting  b)g«tJi«r  ihvKvvrnI  MKiKtilitl 
nwctiauinnw.  bikI  of  traiisverw  ootuniuaiircs  ninning  iNrgvly  in  tao  gmy 
maltrr. 

The  nKPLKS  Acriom  op  tub  Spixal  Com*. 

i  W3.  Tn  ihc  jirecedii))'  jmrliou  of  t)iia  work  we  have  repeatedly  seeti 

int  thnii);h  we  chii  leurn  niiich  cDn<«rniiig  the  workinf;  of  an  orettn  or  tissue 

or  imrt  i>i'  il>e  body  hy  sludyiDg  itM  lieliavtur  when  isolated  fnmi  ti>e  nrat  of  ibe 

l)>Mly,  ftll  the  coDeliuioDs  tbu>  guiued  have  to  be  checked  by  a  study  ol'  the 

bvliKvkir  iif  the  aune  ofgan  or  part  while  it  is  eiill  an  iDteK^l  [tan  uf  tbo 

intact  body.     All  tbe  Mveml  oreaDH  nod  liasue^  are  ta  bi)Liod  to]*etber  bv 

vmriiHia  licH  that  ilw  actioiin  ><f  i.'iioli  ile|ieu<l  on  lfa«  aotiona  of  the  rest ;  and  to 

mty  tliat  tbe  life  of  each  pari  in  ii  function  of  the  life  of  tbe  wlM>le,  ia  no  len 

true  than  to  «ny  thni  thv  lifu  of  the  whole  ia  n  function  of  the  life  of  each 

pan.    This  u  enpedally  borne  in  utmn  lu  nbeii  we  c»mo  to  itu<ly  ihe  actioiia 

of  tbe  lYtitnil  nervoua  avMcni.     We  may,  uu  anutomicol  grounds,  Mepunite 

tbe  a^inal  conl  from  the  nrnln ;  but  when  vie  come  to  coiifider  the  re)|>eclive 

AincUOtK  (>f  the  two,  we  arc  brought  fac4^  to  face  with  thi'.  fact  that  in  actual 

life  ■  lai-BO  part  of  the  work  oftho  bnuii  iacurriisl  otiL  by  meaiuof  tin*  apinal 

ami,  and CODveiwcly  the  npinal  conl  dm-s  its  work  hiibitually  under  ihe  lutlu- 

•Bcc  of.  If  i»l  lit  tin-  diritt.  litddiiig  of.  the  brain.    Wp  may  gain  certain  cou- 

rtutioiM  byttudring  the  Wbnvior  of  the  f^piiinl  mrd  iKiIatdl  frota  the  briiln, 

or  nl*  part*  of  the  »piiMil  conl  isolatcl  from  c^u-h  otbiT;  but  wc  must  be  c\'ea 

lUorr  cniitioUB  titan  when  irc  wcro  •IntHitg  with  other  |>ana  of  the  boily.  and 

mii«t  grmlly  Imitate  to  lake  it  lor  griinto)  that  the  work  which  we  can 

make  the  spinal  cord  or  a  part  of  the  spinal  ifird  do,  when  isolnled  from  the 

brain,  i*  the  work  which  u  actually  done  in  the  intact  liody  when  the  brain 

tufl  spinal  cord  form  an  unbrok&u  whole.     Mun!ovi-r,  tliin  I'auli'iu  l>eeoniee 

■ncnannciy  neeoaary  when  in  our  itudies  we  pass  from  the  simpler  nen-on§ 

•fUeni  of  one  aDtmal  to  i)ie  itiore  t^nplex  nerrous  vratem  of  another ;  fur  it 

i*  by  the  complexity  of  their  central  nervoittt  Ayalems,  more  than  bynnvlliing 

clae,  lluu  tbe  "hi);he«t"  anlmaJa  are  dilTercntiatL'd  from  those  "below  'them. 

When  we  coniptire  ii  rabbit,  a  dog,  a  monkvv.  iind  a  man,  the  difleremxa  iu 

tbe  viucular.  digealivc,  and  nspiratory  wyvtt;nis  «f  tbe  four,  utriking  an  they 

nay  aP[>vHr.  rink  into  in»igniliciincc  <viiD[>arci)  with  the  ilillcrvnci^  exhibited 

by  tbcir  mjirclivc  rcntral  m-rvons  *y»tcnu.     WV  need  caution  wIh'u  from 

tna  rwult*  of  cxiwrlmcntJt  on  diigx  or  rabbiln  nc  draw  coDoluKion*  at  to  ihi^ 

digMioo  or  circtilalioii  of  ninn,  but  wc  nenl  far  gr«uler  nnition  wbtn  from 

tlu  bthavior  of  the  i«olalc<l  spinal  cor^l  of  one  of  thcw  animals  wc  infer  the 

b*bavior  of  Htv-  intact  spinal  cord  of  man. 

A  further  difBculty  meets  us  when  an  cxperinieDtal  invntigalioii  entaila 
operative  inierference  with  the  cenlral  nervons  system.  Rcmoral  or  section 
of,  or  other  injury  to  parts  of  the  hniin  or  spinal  cord  is  veiy  apt  to  give  riiM* 
in  vanitig  degree  to  what  is  known  as  "shook."  The  entling  or  tearing  or 
other  tcsiuu  of  any  eon>^iderable  mm*  of  Dervons  substance  aHccIs  titc  Hctivity, 
not  only  of  the  htruclurcs  imnieilintely  injured,  but  of  other,  it  mar  be  Ear 
dialant  slruetures.  Tbe  nature  of  "  shock  "  ia  mrt  as  yet  thorou[;bly  under- 
ttood,  but  may  |>erba|ie,  iu  pari  at  all  events,  be  explained  by  re^-nrding  the 
lesion  as  a  very  iH>werful  stimulus,  which,  |>anly  by  way  of  inbilulion  but 
■till  more  by  way  of  exhaustion,  deproees  or  auapends  for  a  while  nonual 
ftinctions,  ajid  thia  trive*  riae  to  temporary  diminution  or  low  of  ooiudous- 
new,  of  Tolitiun,  of  reflex  movenienla  and  other  nervoua  aotions^  Tliu»  a 
•o-tioM  throuffh  the  A|iiiuil  cord,  ei,'en  when  made  with  tl>e  abarpeM  loslru- 
tuent  and  niili  tlie  ntnui^t  tkill,  m>  as  to  avoid  all  bmining  as  much  m  ponl- 


TUB  spircAT.  eoftu. 


tile,  limy  for  ii  «http  inifiMtni)  nil  rvikjx  tictiviU-  «f  tlto  corj.  t>r  ii>il«Ml  «W  I 
ulivioits  activitim  of  Urn  wliuk-  central  iwrvuun  ayittcDi.     We  niBV  aiM  ik 
micli  a  "ahuok"  of  tW  contritl  nvrvotw  iiyiitvm  may  aIm>  Ii<^  |)riiliir>:il 
tniddeti  lesions  not  bmring  diroccly  oa  the  mntrKl  D«rv<Hu  s^rMvia,  u 
iuKtaiicc  by  exteanvc  lujiirr  to  »  limb. 

Moreover,  in  rniiny  caaea  in  which  ihc  cITocbi  of  ox  (Mr  i  mental  iDtn^enm* 
have  bran  natcheil  for  Bonw  oonsidpniblp  time,  diirs,  tnnnlha,  or  yeani  ifiit 
tfae  operotjon,  it  hns  been  obKirved,  on  th«  nne  hand,  that  pheDom«na  «hkJ> 
an  conapicaoua  in  the  early  jteriod  m«V  eventually  itUappear,  and,  <m  Ibt 
other  hand,  that  aciivi(i«»  uliiob  are  at  lir&t  abaeot  may  later  tm  make  tkttr 
nftpearaoce ;  rooremenU  fur  iD^tanL-e  whiek  are  at  first  fr^qtient  nfVer  a  whilt 
Aw  auay,  ami  oonveraely,  movenwnts  which  at  6r«t  aeeoied  iiupoKible  an 
lalvr  on  easily  achieved.  We  have  to  dUtiiivuish  or  to  attemtil  to  diuin- 
Kuiuli  between  the  teiD|>UTary  and  the  lasting  cdaria  of  the  <>]>er«tiiin,  Incluil- 
fng  auonjE  the  former  not  only  thoK  of  ordinary  "shock,"  hut  nthen  ft 
ilowfir  d«vi>I(i|Hi>unt  or  loti^r  duratiixi.  In  niwiy  instanow  whvrv  a  )«tt<f 
tbft  <!<!nlriil  iii-rvouK  syM«m  In  by  wwtinn  or  othnrwbe  Hudd«uly  (oparaui 
frwit)  till!  rmt,  lint  ]>l)(Mi»in«iia  MiKgi«l  tlial  tltc  «>'|iiirat<'<l  tMrt  i«  lit  flnl  (ifi^ 
fuuniily  influiint-vd  ii.->  to  iic  iictivittos  by  tbi;  withdrawal  of  rarivu*  inlluawfi 
which  |ir«riouiily  were  hdue  exerted  u{ion  it  hv  tiw  KHt  of  the  «yiitcni.  but 
later  on  Nc«i>iuraoiiut«H  itself  to  the  new  conditions,  anil  Icnnw,  so  to  xiwik, 
to  act  without  the  help  of  lho«  influonocA.  And  indrvd  it  u  |»whla  thai 
some  of  tbo  eflecU  of  even  immedintc  "  shock  "  may  be  due,  not  its  suggtateJ 
bImvv,  lo  the  actMMi  of  an  inhibitory  or  cxhaUBling  stitniituB,  but  Ut  iht 
sudden  CMMtion  of  habitual  influences. 

8till.  iu  spile  of  all  thes«  ditiicuUies.ii  is  puwible  notoaly  tt  ■seerliiin  Ai 
workinK  of  an  isolated  portion  of  tl>e  MUtmt  nerrous  aVBteni,  but  e^-en  u 
infer  from  tli«  results  some  conclusions  as  to  the  riinre  taken  by  that  pMl*M 
in  tJi«  working  of  the  entire  and  iutaot  systeni.    There  oan  be  no  doubt,  tt 
instance,  that  the  Hpinal  oird  am.  (|uite  apart  frtifli  the  brain,  cany  oai 
variuua  reliex  n^^tions,  and,  m4ire<iver,  it  duee  carry  oiil  nctionn  of  iliis  kiad 
wlien  ill  the  intact  orfconitm  it  i.t  working  in  contiict  with  the  brain,    ladixd. 
the  carrying  out  of  various  nflex  aeliona  Mens  i»  bo  <iiii'  uf  the  nvwi  ituj>v 
tanl  fiinctions  of  the  spinal  cord,  m  much  •»  lliat  lh'>ii|>h  the  brain,  "i  >' 
len»t,  piirUi  uf  Ihc  brain  oin  aUn  anil  do  develop  rx-llox  acti'm*.  Uie  npiMl 
(•ord  ofli^m  tbu  beat  ficUl  for  tlw  uliidy  of  Ihwc  actiiing.     Wo  linre  alrwl* 
'$  101)  touched  on  the  general  fcutiirt^ofreJlrx  itclions.  iind  (.•iMwIiert  htn 
tncidenldlly  dwelt  on  particular  instances;  we  may  tlterefon  onofin*  M^ 
selves  now  to  certain  points  of  special  interest. 

S  084.  Keflex  movements  tire  perbnpe  bast  studied  in  the  frog  and  otbtr 
cold-blooded  animals,  «Dce  in  these  the  actions  of  tfae  cord  are  leaf  drpendnil 
on,  and  hence  less  obecured  by  tfae  working  of,  the  other  parts  <if  the  otutril 
tier\'oti»  syatero.  They  obtain,  however,  in  tne  warm-bloodwl  itiaoinml  tho,  tat 
In  tJtCM  special  prejiaraliona  are  necessary  to  secure  their  full  ilevelopmMi- 
In  tie  JVog  the  alii>ck,  which,  as  we  have  said,  follows  u|>on  divinua  nf  tb* 
spinal  cord  and  for  n  while  suaitends  reflex  activity,  soon  paasM  nway ;  witbis 
a  very  sliort  time  ntler  the  bulb  for  instance  has  been  divhled  tlie  tnoM  MB* 
plicated  reflex  niorenients  can  be  carried  on  by  tJie  frojt'A  spinal  cnnl  "bM 
tlie  Appropriate  stimuli  are  npplK-d.  With  the  mammal  the  caaei»vtf5_ 
difieretit.  F(ir  days  even  afker  division  of  tlie  spinal  con)  the  Mrti  of  I 
hiidv  supplied  by  nerves  spriu gin j(  from  the  eord  below  tJi«  sectlcm  nurt 
hibi't  very  feeble  nactiona  <Mi1y.  In  the  do^,  for  iiulanoc,  ancr 
the  spinal  cord  in  the  lower  dorfial  region,  the  hind  limbw  hang  i. 
motionless,  and  pinching  iIh!  himl  foot  evokw  as  a  nsixHiM'  (riiltcr  m^ 
irreguhir  movements  or  none  nt  all.     Indeed,  wur«  our  t^mervatioiis  lii 


TUB    KKKI.BX    AfTlOSS   OP    TIIK   SPISAL   lORD. 


ns 


laliiit  |>i<irtoil  irt  mighl  infor  that  ihf  nsSex  acllop*  nf  the  tpiiinl  eoni  in  Uw 
aaiumiil  were  Imt  fvclilv  ami  iu>i);iiificnnl,     If.  hnwcvcr,  the  miiiniil  iw  kept 
■livo  f.tr  »  l"iigrr  imrifxi.  f.ir  wvck^,  or  lnHlw  rtill  for  iDnaiho,  Ihouicli  i»i> 
oniun  »r  rii!<iu'ritiii>it  of  tin*  >)>inxl  i-»rtl  tiikw  pliu>c,  rvdox  movmii'iii*  af  a 
poworiul,  vnrtii)  hii>)  L-i>mpI<'(o  charact«r  maailtRt  ihemwlvct  in  tlic  liiod 
limbv  Mid  hinder  pnrt^  of  ihc  budr;  ft  verj  feeble  slimuluM  uppiivtl  l<>  the 
•kin  of  theso  rainuiu  promptly  eivct  riao  tu  exlengire  and  yitt  codnliau* 
movoraflBta.     Indeed,  the  more  the  matter  ii  sludifd,  the  stronger  is  the  evi* 
dance  thnt  the  nAex  move meota  carried  out  by  isolUed  portiotwof  the  vpiiuil 
ownl  of  the  mammnl  are  hardir  le»  deKnite.  mmplete,  and  nnrpuwttil,  lliiin 
witneaBed  in  th«  frog.     Il  'n  wurtliy  of  altcntiun.  a§  tiejiriDf;  oot  thai 
rka  made  above  oii  the  ^rent  dit)(rtentiutii>n  uf  the  central  nervoiie  ^ystvoi 
in   the  hi|;hiT  antnials.  that  the  rellex  phenomenu  in  RitiniiualB  vhtv  vory 
touch  not  uulj  iu  difl^rent  ■pet'ii'ti  but  iiUo  in  different  individunis  ami  iii  the 
•Ktue  individual  under  dilferenl  dreiiuistancM.     Kaoe,  a^,  and  previous 
iraiain):.  wetu  to  have  a  ruurked  etftK^t  in  deicrinUiiuft  the  ext«nt  and  char- 
acter of  Ihe  nAex  actions  vrhii-h  the  Hp'tnal  a)nl  a  capable  uf  ennjion  out ; 
ami  ihi»«  seem  also  to  be  largely  influenoei]  by  paMln);  oircum»tances,  sudi 
as  whether  fixid  hait  been  recently  taken  or  nu.     It  hiu  been  OMerted  titat 
the  iaolnteat  apinal  oonl  of  the  mhltit,  nhich  hax  Iw«n  the  «ubject  of  so  many 
experini«nta,H,as  oomimred  nith  thni  of  the  dog  ami  many  other  nianroalt, 
singularly  deftd«ut  in  the  power  of  carrying  unt  complex  n'fli^x  inovenients. 
In  ■(tidying  n-tl<:x  actions  in  man  wn  an-  incl  with  the  <liirii;nlly  itiut  ne 
nerar  have  to  deal  with  a  pircion  <•(  thr  >riinal  n^rd  xsparatod  fri)i:i  the  rest 
of  ttw  central  ncrvoii*  ■vdlnm  niiiltT  the  tiivnrahlc  circunutani'cn  uf  ciLl>cri- 
mpittal  invrslignltiin.    In  mnn,  we  inii^l  be  cxnivtil  to  examiiw  reBex  actiODt 
«tth«-r  whiU-  the  irhnle  nervous  systoni  i.«  iuiacl.  or  when  a  portion  of  the  card 
ha*  b««D  wholly  or  {uriinlly  scprtratcd  by  «onie  more  or  Icm  diffiiH  diMMO 
<ir  by  some  accident  involving  more  or  law  crushing  of  the  ncrvoas  Blnictuna. 
Hence,  the  cautiou  already  given,  as  to  drawing  inferenoea  concerning  man 
from  the  reanlta  of  experiuiRnts  on  aniumU.  acquire  stJII  greater  force. 

i  0S&.  Couliuing  oumelvfls  at  llr^i  to  the  rutulu  of  ex|>erimeuts  on  animals 
,  wa  may  ny  thai  in  both  cold-bhioiled  and  w  arm -blooded  animab  tlte  salient 
V0bMure  of  ordinary  redex  actions  is  their  |>urpatiefiil  liiaracter,  ihouj^b  everjr 
jr    variety  of  movement  may  be  witnewed,  from  a  simple  npoam  to  a  meal  oom- 
j»l«x  mameuvre.    And  in  all  reilex  nioveuienlik.  both  *im|>le  and  compiaz, 
wv  can  rrcogniiee  certjiin  determining  influeucu)  which  more  or  I«u  directly 
eiMilrihuio  to  iho  shafting  of  tliid  purposeful  character. 

Thus  the  fltaturm  of  any  movement  taking  plaoe  as  ]iart  of  a  reflex  action 
are  in  pari  dettrrmiiMtl  hy  the  oharactent  of  the  Btfcrenl  inipulwat.  Kiniple 
MTVOU*  inipuisca  genvratod  by  the  direct  Mtimuhitiiui  of  atTrrvnt  uervv  fibrea 
gmarmlly  rvnkc  aa  rcAcx  movements  mrrvly  irregular  i>)ia.<ms  in  a  few 
nmelM ;  whereas  the  iDor«  o>mpIicat«l  difleraiitiat«l  H-RHorv  im|MilnB  gw 
•laud  bv  the  application  of  the  stimulus  to  the  skin,  readily  eivo  riaa  loi 
lanaand  purp'iwful  movcmonts.  Itiscaj>tcr  to  produce  a  complex  reflex 
action  by  a  >lighl  ))mDun>  on  or  other  stimulation  of  the  skin  than  by  eYOll 
slnwg  iodoction -shucks  applict  diroctly  to  a  nerre  tmnk.  If  in  a  hraiDlaa| 
IVog.  tbc  ana  of  skin  ■•upplicd  by  one  of  the  dorsal  cutanaooa  nerves  be  bsm* 
rated  br  section  from  the  rest  of  tlie  skin  of  the  hack,  the  nerve  beini;  felt 
attached  to  the  mum  of  skin  and  carefully  protected  from  injury,  it  will  be 
fiMind  that  olignt  stimuli  npplioi  lo  the  surface  of  ibe  piece  of  skin  cosilr 
evoke  reflex  actions,  whereas  the  trunk  of  the  nerve  may  be  stimulated  witb 
even  strong  curreais  without  producing  anything  more  than  irregular  move- 
nents.  In  ordinary  meuhanical  and  chemical  stimulation  of  ihe  skin  it  is 
not  u  single  impuUe  but  a  series  of  impulsw  which  [Mu*ei  upward  aloni;  the 


TnB  si>i:«Ai.  ronu. 


MDSory  nerre,  tli«  i-linngiv  in  wliirti  may  be  r<ini|i«rMl  tn  tlti.'  chunttM  ia  i 
motor  nerve  thiriiig  tctitniii^  In  cv<tt'  mfl«K  notion,  in  fiirt,  ibp  o-nlnl 
inrchBiiisrn  m>v  )>c  Wkcd  u]H>n  o*  hi-ing  thrown  iiilo  notivity  ilirouE^  t 
Rumination  of  iW  nfTvn-nt  imj>iiWi>  mncliin);  it.  Hcijw  whil*-  *  n-tlux  :•'  - 
U  ntiiililr  cnllnl  f«rlh  l)y  cvitn  fi-cbk-  in(lucl»i>»-tih<it-k»  ii|i|>lteil  !■>  l!' 
if  tlivv  iHt  repcnti.tl  nifliriciilty  na)>tdly,  k  dolttun'  iDiluviion-shock  ii  in*)* 
fi-cfuikl  nnltM  it  lie  Klrvrng  rnoti^h  ii>  cniiM  in  iho  (kin  or  norvn  ehuievtf 
Ml  ckctroljrtic  nature  sutbcicnt  to  give  rite  of  thtmMlvn  Ut  &  aarios  of  in* 
pulMi. 

£586,  When  n  mnscl?  ii- thronu  inln  mnlrnotion  in  a  rvfl«x  aiTii  ' 
pilch  of  the  ifouiid  which  it  )^\'ee  lortb  doee  not  varj-  with  th«  stiniiii 
IS  coDAtiini,  bein)*  the  snmc  an  tliHl  ^-iveii  forth  by  a  muscle  ihrow  n  iiii->  <.'*■ 
traction  br  the  will.  From  which  we  infer,  eveii  bearinf;  in  mimi  th»  iH^ 
ciiJ^inn  in  ^  >fO  rouoerDine  tbeualiire  of  the  niiiscuiar  ^xind,  that  in  a  rcte 
action  the  afferent  imfHilMB  do  not  !-im|ily  jmss  ihrouch  ihi-  iviiire  In  tkl 
same  way  that  they  iiags  aloii);  nflereiit  nerves,  but  are  prufoundly  modified. 
And  in  accordance  with  thi!>  we  lln<l,  aa  we  *)tnll  see,  tliat  a  reflex  actnia 
taken  up  an  aniouDt  nf  time,  the  grcnier  part  of  which  Lt  spent  in  the  carrr- 
fng  out  of  the  central  chaugm,  and  whicli  though  variable  iw  alMura  aioch 
lon^r,  aiw)  may  be  very  much  l"n)^T,  than  that  tnkm  up  by  ike  mn 
nuBBfcG  of  a  iiervotni  iropulw  along  a  cormpoiKling  length  nf  iten'i~  ^*■'- 
The  term  reflex  action  ■■  therefore  nn  untwitanb'  one.  The  artcrrnl  : 
ia  ni>t  xtmpty  reflectotl  or  turned  aaidc  into  an  cffi-n-tit  channel ;  <tO  tta  ■mut 
nt  the  r<rntr)-,  it  ularlN  change*  of  a  different  nulnro  from  ami  mort  cumplM 
than  il*  own ;  and  the  miw  of  effcn-nl  inipnlw  is  the  r<»iill  of  th<iM  muff 
complex  chanec*  not  the  merv  continnalion  of  the  simpler  aHeri'iil  tiapulf^ 
In  other  wonis,  tbc  inlorvat  between  the  advent  nt  the  central  organ  <' 
nlh-rcnt,  iind  lh«  exit  from  it  of  etfcreiit  impulsn,  is  a  busy  linu>  Cit  lie 
DftrTOlM  (ubslnnce  of  that  organ ;  during  it  many  proocMes,  of  whicli  we  hare 
■t  nment  very  little  exact  knouledKe.  are  Iwing  carrie<l  on. 

§  d87.  The  character  of  the  movement  ffirming  part  of  n  retlex  aetloait 
abo  iulluenced  by  the  iiilenaity  of  the  stimulus.  A  alipht  alimuluB.  ra<}iM 
gentle  contact  of  the  akin  with  aome  body,  will  proiiiice  one  kind  of  mni*- 
ment ;  and  a  Mroiig  atimulua,  aueh  ma  a  almrp  ]>rick  applied  to  the  aantr  ipri 
of  akin,  will  call  forth  (juite  a  difTerent  movement.  Wlien  a  decit{iiutf<l 
make  or  newt  it  Mi»j>ended  and  the  >kiii  of  the  tail  ali^htly  touchol  *<tll>  tlit 
finger,  the  tail  IwJidn  toward  the  finicer;  when  the  iikin  ia  pricketl  or  batX. 
the  tail  w  turned  away  frvim  the  offending  oliject.  And  m>  in  manv  "H" 
inataiKiv.  It  mu«t  be  rememliercil.  of  i-ounw,  thntadifterenoe  in  thei:i 
of  the  MimuluM  cniaila  a  difll^rcijce  in  the  charai-ten  of  theeflereni  {»(■»■-'. 
gnille  CODlact  gi\m  rite  to  what  we  call  a  nenmlion  of  touch,  while  a  ^f 
prick  gives  riw-  to  pnin,  consdousnew  bcitig  diftVrently  eflN't4ii  in  tlie  w 
caMf  hecjiiiM  the  aflerent  inipiikta  nro  dirfcn'nt.  Hence  the  intlann*  ■■ 
i|iK-Ktion  are  in  reality  fiiller  illustrations  of  the  dejH'iidence,  l«  whiefc  w» 
called  allentton  above,  of  the  chitraclerR  of  a  reflex  movement  uu  the  HM^ 
ncten  of  the  aflerenl  impulses. 

Furtlier.  ns  we  have  already  pointed  otit  ($  101 )  while  the  motor  i>i|w^ 
started  by  a  weak  atimutus  applied  to  an  atlereiU  nen'oareirARsmillrH  rW 
a  few,  tlioee  started  by  a  strung  ^limutiia  rany  apread  to  many  eHerenl  u«rv^ 
Oranting  that  any  panicular  dllereni  nerve  »  more  especially  aaaneiattd  »il* 
cerlaiit  efferent  uervea  than  with  any  otliem.  ao  that  the  reflex  impulMf  ^ 
eraled  by  atferetit  impulaea  entering  the  «>nl  by  the  liirnier  i-aa*  with  tiw 
least  reaiatfl nee  down  the  latter,  wv  miiat  evidently  admit  further  that  rfh** 
efferent  nerrcn  Ut  ab(»,  though  leva  dinwtly,  connected  with  the  «ome  if^ 
ent  nerve,  the  paaMgc  into  the  avootid  efiereni  nerve  meeting  with  a  ff«" 


TOE    REFLEX    Ai'TIOSS   OF   THE    SlMSAL    lORD. 


715 


rrmtik 


try. 


tra 


rcHUtiino^.  When  n  Trog  in  |xiiMn<.il  with  ilni'cliiiinv, 
m  tlighl  loiicti  on  nny  {mtI  oI'  iIu'  ■kin  may  ctiiiM>  <v>nvulsions  nf  IIh'  whuJc 
butj  I  tltmt  »  to  MV.  the  nflVrcnl  impiiUcs  |iii>«ii)|^>  iilnng  Any  ninglo  aScn-nt 
MTTv  m»j  gtv«  rttts  to  iho  iliwhiir);i.-  iif  e-ti'eicul  itii|niUM  along  any  or  nil  ol' 
tW  rMrrrnt  oema.  This  pr»r<-a  thnt  »  phjYiolo^ical  if  ni>l  un  iiiint^ninil 
continuity  obUiiiw  betwi<cn  all  the  |>iirl«  of  llic  »j>iiial  coni  wliich  nir  cun- 
ntsrd  in  rcHex  acli<<n,  thai  ihc  nervous  network  iiilervcniiig  between  thu 
■ftfvnt  anij  eKervni  fibn-f  I'orniB  alung  the  uliule  leiiKlh  of  the  coril  a  fiinr- 
liaDally  continuous  tielil.  This  coDtiiiuouit  iielODrk,  however,  we  must  eu|>- 
be  market)  out  into  irac-te  praaeniing  f^reuler  or  leM  resiaiaiice  to  the 
of  the  inipitlses  into  wliicii  alTereitt  impulMH,  coiuiiiK  slontt  tbie  «r 
■fl«rent  nerve,  are  trnDsfuriiieil  on  their  advent  nt  the  network;  and 
linjcly  the  path  of  any  series  uf  ini]>iilitc-i  in  the  uetwork  wit)  be  deler- 
.[d«iI  larKely  by  the  energy  of  the  ullereiit  itnpiilM-«.  And  the  action  of 
c'hnine  luny  be  in  pari  explained  by  9>uppo^in|r  ihut  it  n'[1u<-e3>  aud  eiiual- 
tbe  iioriiiul  resintanci-  of  ihitf  network,  tut  that  cvrii  weak  iinpulM^  travel 
r  all  its  triicin  with  great  ease, 
§  568.  Further,  the  movement,  fiirming  |Mirl  nf  a  reflex  aclioii,  t'uriefi  in 
.rooter  u<ToriJin^  lu  the  particular  part  <>f  tliv  bndv  to  whicli  the  Mimulua 
pptird.  The  retlex  aetiunit  develoixil  by  *timiilattnn  of  ihe  inlenml  vio- 
are  difTerenl  from  lh<iM:  excited  by  ^liinulntTon  of  (heskin.  We  have 
>n  to  think  that  ibc  cmtnii-tiou  of  vr  other  ehaogw  iu  a  skeletal  miuelv 
itosr  imxluee,  by  rvllex  action,  eonlntctioDR  of  other  nUKlw:  and  nich  reflex 
•aUQtit  al»o  <iifl(rr  from  lhc«e  vtnrled  by  Htimiihitifin  of  the  akin.  Id  reflex 
•cHoiM  Marled  by  applying  a  tfimnliif  to  the  skin  the  movement*  vary  largely 
aocording  to  ths  pnrtirnhir  area  of  the  ikin  wbieh  ia  oflectcd.  Thni,  pinch- 
iM  ihe  tbUa  of  fkin  iurrounding  the  anus  of  the  frog  produces  dilfennl 
cncU  from  ihow  wiliicaKd  ivhrn  the  tiank  or  toe  is  pinched;  and,  speaking 
generally,  the  stimulation  of  a  particular  *p<)t  calln  forth  particular  nwve- 
ments.  In  the  caw  of  the  simpler  reflex  movemeiiis,  it  appeara  to  be  a  gen- 
eral nile  that  a  movement  started  by  Ihe  siiiiuulalton  of  a  aenitory  surface  or 
region  on  one  side  of  the  body,  U  developi-<l  »u  the  same  Hide  of  the  body, 
and  if  it  spreadH  to  the  olher  side,  mill  n'mninii  inibt  inten.-te  on  the  ttame  aide ; 
ir  movemeul  on  the  other  side  moreuver  in  Hynmn-trical  with  that  od  tiie 
tna  tide.  It  hu»  been  nminlained  ibnl  "  cro«Md  "  or  diagonal  reflex  move- 
nta,  Bi  where  miundiiliun  of  <>ne  fur<:-f<iot  leads  to  movements  of  the  oppo- 
hind-limb,  do  aul  occur  unle»  lumc  [Hirtion  of  the  bulb  he  led  aliacbed 
ibe  tpiiial  con).  Seeing  that  loeomotion  iu  fonrfoolcd  animals  i*  largely 
ed  by  diagonal  mnvenienlK  of  the  limlm,  nno  WfMild  rather  hnve  cx|)ecleil 
find  the  spinal  con)  ilwlf  iimvidiij  with  nirchitiii«ni*  to  assist  in  carrying 
in  cMl;  and,  tnih-cd,  it  h  aJlirm'-d  tbat  in  the  msc  of  cold-blooded  animala 
of  nuinv  young  nianinials.alUr  division  of  ihc  spinal  cord  below  the  bulb, 
'^tla  •timntation  will  provoke  a  dingimal  niovenwnl,  slight  pmpurv  on 
ir»fo»t  for  example  givin*;  riw  to  nioveiuenu  in  the  o|>pu8ile  hind  It^; 
ig  stiniuhif,  honcver,  will  pniduce  un  ordinary  one-aided  movement. 
_  when  in  a  Aoff  Ihe  euni  hiu  tHwn  dividml  in  the  lower  ilxiracic  r^oQ 
•<>  tlinl  the  hind  limbs  depend  on  the  lumbar  cord  alone,  a  rhylhmicnlly 
Tvpeai<-d  drawing  up  and  letting  down  of  the  hind  lirnb^  \»  nitiieseed  wlwn 
Ihne  areallowol  to  bang  down;  and  these  movemeniit,  nhich  appear  to  be 
of  a  reflex  nature  exi-ited  by  the  pendant  lucitiuu  of  Ihe  limbti.  are  often  seen 
lo  aJtemate  rej-ulBily  in  ihe  two  limb».  the  right  leg  beini;  extended  white 
the  left  leg  is  l*eii)g  diiiiin  up  and  rirr  iv-r^.  It  niav  further  be  obwrveil 
Ibai  if  the  foot  of  <>iie  pctidant  limb  lie  piiiche>l  nhile  tite  other  limb  i^  pna- 
rifdjr  flexed  the  flexion  of  ibe  limb  which  i*  pinched  i>  acvonipnnied  by  an 


7](t 


TnS  SPIlfAL  CORD. 


vxtt'iietou  of  tbc<itiii-r  linitt.     In  tlmi^  twiwicu.  bowcTCr.  dlfl^rvul  ftmouW 
M  iilready  urgwl.  tlilTL-r  from  c«ch  ithor. 

§  SBB.  Kroii)  tbeiM-  iiml  similar  (iliriii>nii-iia  w<-  mny  inl't^r  thnt  th«  nnrmii 
■Ntwork  spolcco  of  above  U,  m  (4>  »)M^k.  iuA{)jk<(I  out  into  norviMu  nuctw 
\ttm  by  to«  eetablialinient  of  linos  of  ^raiiicr  or  1cm  rMutwiM,  w  UuU  th 
dwturlHmiMe  in  il  {[enerated  bycertiiiii  Di>l«rcni  ini|>iitms  arc  dirwt«d  int* 
oettain  efferetU  ehAniKU.     It  may  Ixr  adtied  ihnt  though  fioiiD)>i<rui»i»lT  jm 
(wspful  luoTemeiiU  seein  lo  need  the  coDCurreut  ncci'm  of  several  aF^nii-aunf 
ili«  cord,  and  ta  a  rul«,  the  itrmter  ibe  teni{<h  of  lb<3  i-»rd  involved  the  mnrr 
complex  and  Ih*  more  disliin-tly  ptirpfiTeful  the  raoveiueot,  still  the  mot'- 
nwnis  evoked  by  evt^n  a  ^^iiit-iiL  nf  the  curd  may  be  purjHMeful  in  cbancM: 
henee  we  munt  co[iclu<lo  thai  nvery  sef;awot  "f  the  uervuus  neiwaik  ii 
mapped  i>ul  iniu  niL-chaiiiaiii.->.     Itut  the  arranxenteat  of  thi>ae  meebkunaik 
oapecialty  of  llie  more  complex  ones,  a  not  a  Kxed  and  ri>;id  ontt.     We  ran- 
nut  alvray*  prviliot  vxaclly  tlwi  nature  of  the  moreaaeiit  ivbicb  nil)  na»i 
frrtm  the  Htim illation  of  any  pnrlii-ular  •put,  beratiM  ibe  reault  will  rut 
acoonliiig  to  the  cundtlion  iif  thi.-  Hpinal  catA,  e«peeiallv  in  rolaiion  to  1^ 
Btrenglh  and  ehiiriictcT  of  the  I'limiiluit.     Moreovor,  under  a  chang*  of  fir 
oumsUnowa  movctiwDt  quiti-dilTenfiil  from  the  normal  an**  may  dim  let  If 
ap|icnranco.    Thus  wh«'n  a  drop  of  iicwl  i]>  placed  on  thn  ri^Ht  tlank  oft 
brainleea  trng,  the  right  foot  is  alnrnst  tnviiriably  tiwd  lo  rub  oA'  lti>-  n-r- 
in  tliit  there  appean  nothing  more  thitii  n  mere  "  mochanicnl  "  reflex 
If,  however,  th<^'  rif^ht  leg  he  cut  olT.  or  the  right  fwA  be  ollierwiaa  bn  : 
from  rubbing  oil'  the  aeitl.  the  leA  foot  »,  under  tbo  exeeptkmal  . 
MAOoea,  aaed  for  tlie  purpose.    This  at  fin^t  sigbl  looks  like  an  iniclii^'Qi 
choice:.    A  choice  it  evidently  iH :  and  were  lher«  many  instanoes  nf  dIma 
and  were  there  any  evi^leooe  of  n  variable  automaUsm,  like  thai  wbioli  ** 
imII  "  rolitJoa,"  being  manifeated  bv  the  spiniil  cord  of  the  {n*ii,  we  tlv!!'' 
he  juHli6e<l  in  i4u pinning  that  the  choice  wa^  dt'termined  by  an  tiiU-l!  . 
But.  ax  we  shull  buvc!  ix-cawon  later  on  lo  )>otnt  out,  a  frag,  deprive 
brain  so  that  the  spinal  (^i>rd  only  in  left,  mnkiu  no  stxintaneoiiii  ni  i-' 
at  all.     Hucb  an  i-nltre  aWnoe  of  spontaneity  is  wholly  inconaistviit  "■■'■■ 
imnhmIod  of  inttflligvnne.    Then  a^nin  the  above  vxpenmcnt,  if  not  the  odIt 
imtance,  h  at  all  evenu  by  far  tliv  miut  striking  inMaooe  of  ohoioi>  ua  tk 
part  of  a  braiiilw*  frog.     We  are,  Ihtrrefore.  led  to  otmiitudx  thnt  ihi*  \itua^ 
mena  must  be  expIaiiMx)  in  sonMOlht-r  way  tlian  br  bt>i»i;  ri^fcrrrd  to  lb 
WM'king  gf  an  inl4)II!gMici\     Morettver,  t)ii«  oonclumon  ia  sutiporuwl  hy  At 
behavior  of  other  animals.    Thus  simtlar  vicarious  reflex  m  >vviuiints  ebit 
be  witneesed  in  mammals,  though  not  perhaps  to  such  a  striking  oitsni  i 
in  firogn.    In  dogs,  in  trhich  partial  r«-m'>vnl  of  the  oon-bral  bemisp^'      ' ' 
AptNumntly  heigntenod  the  rcnei  exdiabiticy  of  the  apinal  c'>rd.  the  - 
able  •onttching  roovomenla  of  the  hind  log  which  are  called  ftrth  l>i'  iniH' 
latinKa  particular  spot  on  ll>e  loins  or  side  of  (be  body,  are  executed  briti* 
l«g  or  tJie  Oppooite  side,  if  the  ley;  of  the  same  side  be  gently  lietd.     In  thi< 
oaM  the  vicarious  movemeuu  are  ineShutuI,  the  le^  not  being,  as  la  thtraff 
of  the  ttojf,  creased  over  so  as  to  bear  on  the  ^pot  stimulated,  and  f*a  iM  ^ 
considered  as  betokening  inUlligcnce.     Again,  the  "  mechanical  "  naiart*^ 
reflex  aolioos  is  well  illustnted  by  the  behavior  of  a  decApitaleil  toAt' 
When  the  body  of  the  aoiinal  in  this  condition  is  brought  into  otntsri  u 
several  places  at  once  with  an  arm  or  a  Htick,  complex  roAcx  movrmeni**" 
excEt«il,  the  obvious  purp^MO  a*  well  as  elTucI  of  which  ia  to  tirini-  tbr  bjl.' 
mund  the  obje<:l.     A  deoapttatail  auake  will,  however,  with  equal  ami  ^'*' 
rMdinusi  twina  iisclf  round  a  rod-hol  bar  of  iron,  which  is  mtJe  to  1n>^ 
ita  skin  In  several  i)1airc«  at  ihi-  s-imo  time. 

^  590.  lu  consiiUriog  ihi-  naturwuf  ibff  events  in  the  spinal  oofd  «'><('' 


Till:    REKLEX    ACTIONS    OP   TUB   STINAL   CORIK 


ri7 


krvraiiae  the  belinvwr  of  l)iv  fmg  in  the  iofilaDce  jiiat  mentioned  ko  must 
btar  ip  roinil  iliat  (he  mov«ntcnt*  in  qucelion  ire  "  cuoitliniilcd ; "  ihal  b  li> 
HT,  no4  only  stv  many  distinct  inn^clee  hrou^fhl  into  ulny  but  certain  re)ii- 
tic'Dfl  mm  niainUined  belTreeii  the  amounl,  tluralion,  and  exact  time  of  occur- 

Eice  of  the  conintdion  nf  each  luiiiicle  and  ihoee  of  the  conlracltutia  of  il« 
low  mwcln  tbarin^  iu  Ihe  movciucuU  In  the  ahdenc^  of  sueh  (-(Hirdiun- 
lioa  the  niovemeol  would  become  irregular  and  indlei-lnul.  We  »ball  have 
KnwkiD  later  on  iu  dealing  with  voluntary  movemeuiH  in  puint  out  that  the 
fl>t>rr) illation  and  hence  tbe  due  acn)iii)iluhment  of  a  voluutary  movemeot 
a  (IrtM'iidcut  on  cenaiii  aRerent  im|>uli4es  pufsinj:  np  frvin  tbe  contraettug 
BU'Ctrs  t"  iho  w-iilnil  norxiiud  iiytitt'm.  and  t("idin^  the  dischargL-  of  ihe 
tfrtf  nt  imiMibv*  which  rail  furih  the  c<>iilruirliiinii.  Whi-n  iht-ab  ntlrrvnt  ini- 
nilan  afltct  cMweiouaDeM  we  anenk  of  Iheni  a«  comtituting  a  "  mu>i-ul«r 
tDM  ;  "  it  if.  a>  we  liball  we.  by  tnc  "  muteular  trntu  "  that  wc  become  aware 
if  and  can  ajiprcciate  llie  coiiilitinn  nf  nur  TuuKcln.  But  we  have  reaxon  tn 
fciak  that  the  afl«-ri-Hl  impulw*  which  rnniitiliite  thu  l>a»iR  i>(  the  miiiTtiliir 
Itnfe.  whatever  Ik  their  ciacl  nature,  iu  cirder  to  play  their  part  iu  hnnginf; 
•bout  Ibo  coord i nation  of  a  voluntary  movement  need  not  puio  rijfht  iip  to 
tbe  brain  and  develop  a  diclinct  muscular  "KCnNe,"  but  may  produce  thi'ir 
tffttt  by  working  on  Ihe  nervoua  ineubanixnui  of  the  npioal  cord  with  which 
Ibe  tnotur  fibtt*  carniing  out  the  noTCinenl  are  connectol.  In  other  word^, 
|kbe  coordination  of  n  volimtary  movement  tnke«  place  in  tbe  part  of  Ihe 
tailiRl  cord  which  carrier  out  the  movement,  and  not  in  the  brain.  thun};h 
the  tatter  may  be  cooBci'iua  of  ibe  whole  movtinenl  inetuding  its  coord innticm. 
But  if  the  <niDBl  coid  po««f>w  mechnnifms  for  carrying  out  co'Tdinaied 
punrmevts,  which  in  the  cuk-  of  voluntary  movement*  are  discharged  by 
perrons  impulw«  desecndiug  from  tbe  brain,  we  may  infer  that  in  reflet 
(iclioaa  the  fame  m^chanirm^  ate  bro(i]>ht  into  action  tliuti)-h  they  arc  dis- 
tbarcrd  by  aflertiit  impnltiit  coming  ulimg  afTvreut  iK-rven  instead  of  bv 
ta>pulM»  ileiteeiidiug  from  llw  brain.  The  niovementa  of  rellex  origin,  in  afl 
tbrir  tca!ure«  fxcept  thfir  eKcitiiiii;  caure,  n)>)H'ar  identical  with  voluntanr 
BMivtmrnla  ;  ihc  twu  can  only  he  di^tingiii.ihn)  from  <>ncb  other  by  a  knowl- 
tdge  of  the  exciting  i-aii*e.  Anil  it  weeniH  uuniuttonable  to  nnppoiH:  that  tha 
•pinal  rord  fhnuld  piiweMi  twu  wet*  of  mechaninni.i  in  all  r(9|)i-i.'()i  idi-ntical, 
we  ibat  the  une  if  diiirl)iirge<l  liy  volitii>iial  impiilw-v  Iroin  the  bntiii  aii4l  the 
plhcr  by  nllprrnt  inipulfiii  fmm  nllirrent  uerveit. 

iWr  are  lid  therefore  to  the  concluvion  that  in  a  reflex  action  two  kindo  nf 
ffcrcnt  impuln-a  are  concerned  ;  the  ortlinary  aflercnt  impidiH^«  which  di^- 
ebarge  iIm-  nervout  mechanism  within  the  conl  bikI  m  provoke  the  move- 
Vtcnt,  and  ibr  aRerent  impulHv  which  conntvt  that  nervou*  mrclianitm  with 
Ibe  miucles  about  to  be  calletl  into  play,  nnd  which  take  part  in  the  coordi- 
nation  of  tbe  noTODenl  provoked.  Tbe  natura  of  thcw  latter  afferent 
[mpuleee  is  at  prrwnt  obacure;  nu  know  iiit  yet  little  more  than  the  fac*  of 
illieir  existence ;  but  if  we  admit,  aa  we  ecein  compellnl  to  do,  that  the  char- 
jBcUf  of  S  ntex  action  is  determined  by  them  fla  well  aa  by  the  afTercul 
Aupabea  whtcb  actually  discharge  the  mechaniam,  it  seema  ponible  thai  a 
Jbller  knowledge  of  lhef«  coiirilinating  alTerrat  impulses  may  aflbrd  an 
aitetjuale  explanation  of  the  fact  that  when,  an  in  the  case  of  tbe  froff  in 
ii|U**lion,  the  uxual  wt  of  muscles  cannot  be  employed  by  tbe  acr^'ous 
Ettvdianlsin,  recoune  b  bad  to  another  set, 

I  We  liavc  avoided  tbe  introduction  of  tJie  wonl  "consciousness" as  un- 
[aectfsairilv  complicuiiug  tbe  (|ueelioD ;  and  it  would  be  out  of  place  to  ditmisa 
[|iey«li«logK«)  probleoia  bere.  We  may  remark,  however,  that  since  we  have 
DM  objective  prooft  of  consciousDeee  outaiile  ounelvea,  and  only  infer  by 
■nakgy  Ibat  mch  and  tucli  an  act  i*  an  outcomeuf  cuntciouHtetaon  account 


THE  8PIXAL  OOBD. 


of  ict  likcii«w  Ui  Ktrlo  nli:r)i  nrv  the  ouknnw  of  our  mro  OOdtdlMtBNi «> 
cODcluHe  ihtil  iht!  braiulniK  rmg  |m>mmmm  no  fteUrc  cunxdotUMM  Iflwau 
own.  lK<cnii«!  alMMttiM'  of  .■<}ic>iiuiim»ii*  iiK>v('ciMmli>  Mxnu  u>  Iw  InrooQciUliW 
witli  Uw  cxiKiciicr  »f  n»  iictivv  oupMcioiwiicw  wImmd  v«r}' n«M>»rt>  'umwnm<4 
chaogM.  (^niwuHii>tivi«.  iiK  vFc  r<.-0(>giiiM  it,  tetmt  to  Ixi  nMcwsrily  bperatiB; 
an.  nr  to  lie  iDcJiwolulily  sMiicinlcd  with  tbe  [ircMtm)  of,  »a  latnmati'! 
re|)enlfd  iutenuil  Hiiniultis ;  iu»l  we  cnnnot  raooeivo  of  thnt  stimulus  Ikiling 
Id  excite  raochtniinis  of  ronvciumt  which,  as  in  (he  ca«e  of  the  btaiatai 
fntt,  are  confoMcdly  prmont.  Wc  may.  hoirevor.  (Ii»linguub  betwen  ■ 
nclive  cootinuous  coiMt-ioasium.  iwh  iw  we  iiBitnlly  iiCKlcrataiMl  hj  tbe  Itfa, 
mill  a  jiast'mg  or  monieiitarr  condition,  wliicli  iic  may  apeak  of  as  emntririn' 
ilGtt,  but  which  is  wholly  dteooiilinuous  fmni  hh  anlecedent  or  fnim  m  -  - 
qiwnt  eioiilar  momentary  cooilitioD  ;  an^I  iudeed  we  may  eiipixne  : 
complete  couMMXHUeas  of  oureelve»,  ai)*!  tbe  similarly  comjibitc  <-<  i 
■Mm  wbtch  wfl  iofer  to  exist  io  roaoy  aoimats,  haa  been  (iruilually  . 
nut  of  Auch  a  rudimemary  conscionnieBs.  W«  may,  on  Vi'm  view,  rappf 
tbat  every  nervous  actiop  of  a  oerlain  inteutiiiy  or  cbamcier  i»  artximpaoM 
bv  M1IUI-  umiiimc  of  oouai-ioii^neHa.  whicb  vre  mny,  Id  h  way.  coiuimrv  loliu 
light  emitted  when  a  t:oiiibuBlioi),  previoutly  fciviuK  Hoc  to  invbaiblv  hml,  win* 
fiercer.  VVc  may  thus  infer  that  when  the  brniitlcMt  fn*^  i«  stirr«l  bv  luw 
etimulu*  to  a  rcllex  act,  the  apiual  conl  is  lit  up  by  a  momeuury  Aatbtf 
eoneciouaiiow  coraiufc  out  of  darkneas  and  dving  airny  into  darkncM  tmnn 
and  w«  muv  porhapt  further  infer  that  Htich  n  piMiing  consdonaoeA  vAt 
better  develi>|><!>l  the  larger  the  portion  nf  t)i«  oord  involriKl  in  the  radex 
aet  and  tbe  more  complex  lh«  moTwnHit.  But  sueb  a  momentary  flaA. 
even  if  we  lulmii  tbi  oxiMl^ice,  iiiionwthiBgwrydifltfreDt  from  cunMiaosiw* 
aa  ordinarily  und«r«lood,  i«  far  nmovod  fh»iii  iiit«Uigenee,  and  canaot  W 
appealed  to  lu  explaining  tho"ohoiot"tpok«o  of  abore. 

^  Ml.  Lttslly,  the  chamcten  of  E  Kflax  movement  are,  aa  we  Deed  liinil* 
■ay,  dependent  on  the  intrinsic  cotMlitJon  of  the  cord.  I'he  action  of  UrTchMi 
jutt  alludc<l  to  is  an  ineUtnce  of  nil  apfnrcnt  augmentation  nf  raflox  WlAa 
"hml  explained  by  suopoeing  thai  ih*.'  rrwirtamxH  in  tbe  cord  MW  \imill*i 
There  are  probabljr,  Imwever,  casM  in  which  the  explosive  tourgj  of  i^ 
iicrvoua  mibstance  la  pautiv«ly  increased  above  the  normal.  OonvenH'lv.  \" 
variouit  influences  of  a  defUMsing  cbaraeter,  aa  by  rarioita  wiMth> 
other  iMiisana,  reflex  action  may  be  lessened  or  preveated  ;  and  thi>  j.^^ 
may  arise  eitlier  ftom  au  iucrewe  of  reaisuuice  or  (Who  a  (liminuLion  in  ite 
artual  di«charge  of  energy.  So  also  xiurious  diteaaei  may  «o  nfli-ct  llir  simmI 
mrtl  an  to  prtxiuce  on  the  one  hand  inoreaaed  reflex  «xdtal>ilitv-.  m  thai* 
merv  touch  may  prodooe  a  violent  movement,  and  on  the  other  bund  iliauii' 
iiihcil  rcllex  exeitabilily, so  that  it  becaucedilTicullorimpOflMble  to  call  fuRk 
a  n-Ilex  aeiioii. 

S  SOS.  When  we  oome  to  study  tbe  reflex  actions  of  man  we  shauU  M 
fintl  iM^rhajici  be  inclluetl  to  infer  that,  oinee  in  him  the  spinal  con!  i*  *' 
largc'v  iiivil  OH  the  tn.'ttrument  of  the  bniin.  tln'  induprndeni  rellex  nciiro- 
of  the  eord,  at  IcM  audi  aa  aflect  *kelcul  mui>el.j(.  arc  in  him  of  iimr^  ^' 
im|ioriKnc<!  than  tJnoy  apponr  lo  be  in  aniniaU.  and  cxirarienoe  seems  I"  *if 
pon  (bix  view.  But  It  must  be  reoMnbMfd  that  in  his  case,  aa  we  ln" 
alrcndv  i>uiled  ($  AM),  we  luck  the  guIduHx-  of  experimental  roalts:  ** 
an  iiblij^cd  l»  tnial  to  the  <iiitan^lt)d  phenomena  of  disnue  or  to  a  «til<tr*( 
tbe  liehaviiir  of  tlic  oord  while  it  is  Mill  a  {mrt  of  an  intact  nenrouasyX*"; 
ami  each  of  ihrte  nti-tbod*  pnaonts  difBculties  of  it«  own.  Tbe  nwveniM'*' 
wliieh  in  tbe  iniact  human  body  we  ran  reongnize  aa  indubitable  nll«i 
RClions,  are  lu  a  rule  itimple  and  unimportant.  They  are,  in  by  Ur  1^ 
greater  numlwr  of  iustanoe^  occasioned  by  stimulation  of  tbe  akin  or  of  tk 


Tlir    KEKLEX    ACTIONS   OX    THK   SI'INAL   CORD. 


nv 


BUraus  tni'iiiltniDi?.  for  llic  muM.  |iart  inviilve  a  iVn'  muitcln  only,  iiotl  ntrely 
hdioMc  Kiiv  vcrv  coiniilirx  tiHinlinatiiiii.  Tliv  llt-xiiiu.  fullon'od  u,V  exundiiu, 
f  Um  \og,  nhtch  i»  i-nlUil  forth  \ty  tickling  (lit-  note  >if  tlie  fiiotr  or  tlic  wink- 
k^  of  tbe  cyv  when  ll>v  cuhk^i  <>r  vniijuiictivii  is  I»iicli4<il,  ninj  perba|M  be 
Inrdcd  as  tlic  Ivjn-  i>f  ihvm'  ntitvemcalK.  A  vcrv  ■■diiiiikiii  fona  of  r<4ex 
Itmt  is  lluU  iu  wliivli  u  iniitck-  or  ({roup  of  mu^oU-*  i»  tlir^wD  into  cod- 
tkctton  l>T  Btiiniiliitiim  of  thv  uvrrlyini.'  or  m-igliboriiig  »kiti,  lu  when  tlic 
bdominal  muAclca  L-untmct  ui>uti  >trukin^  the  8kin  of  the  ubduniLii  or  tliv 
•tide  is  ntnctcd  upon  MroKing  tlw  io«i<i<?  uf  tho  thigh.  A  rvHi-x  niitve- 
kot  mar  occur  a»  thr  result  of  utimuUlion  of  nn  organ  nf  Kpccitil  wuso. 
frti  of  ti>(>  ceiilml  nvnoue  »ri<liMn  other  thttn  l\w  gpiDiJ  vurd  serving  n»  lliu 
Intre.  A  fouDd  or  n  floeli  of  light  rrndily  prwlucts  a  start,  »  bright  light 
talus  the  03'e  niiik  and  may  oiuse  n  ptrnMO  to  niwze  (the  groalcr  coordiiia- 
pa  manifeBt  in  thi«  lu-t  bi'ing  duo  to  the  fuct  that  the  complex  r«»pinilurT 
pcchnniifn  b  hrouuht  into  plitv,  $  ^'l^).  and  reflex  movoments  may  rcfiiilt 
(DO  s  laste  or  smeri.  A  special  form  of  reflex  nctioo,  or  at  Icul  an  actioo 
iwmblitig  a  reflex  action,  is  called  forth  by  sharply  striking  certain  leii- 
^His;  for  iualance,  linking  the  tendon  below  the  pat«lU  givcti  rise  lo  a 
^(Idcu  extension  of  the  leg.  known  a»  the  "  knee-jerk ;"  hut  it  will  be  beet 
B  dim^uM  these  "  teudmi  reflexee,"  or  "  muscle  reflexet,"  ua  ihey  are  ealled, 
birr  oti  in  uitolher  conneetion. 

rOn  tbo  nhoti-  tbe  reflex  mnveiuenU  carried  out  by  the  inluct  uervuus 
^stmil  of  mau  UK,  ne  repeal,  Di'aut^  aud  i-um pa ru lively  simple:  but  nc 
m  Dot  iustified  iu  inferriug  from  thia  that  the  htimau  ipinal  conl.  left  to 
ItMlf.  b  inca]»ble  uf  ditlug  more;  that  owiui;  lo  thr  predomiimnt  activity 
H  thv  brain  it  has  loat  the  ]>uwcnt  [lutseNMnl  by  the  «pinnl  cord  in  the  lower 
niiuaU.  For  it  may  be  that  the  cord,  ivhcn  juim-d  t«  ihe  bmin,  u  through 
nrioiu  iuflucni'CM  pnti'^eding  from  the  InUer  in  n  dit)i.-reiit  cunilitiuu  from 
luit  in  which  it  i»  when  aeixinttod  from  the  brain;  indi?ed,  we  have  reason 
D  think  that  this  in  ■» :  and  we  may  her<'  remark  that  in  the  lower  animals, 
la  in  tunu,  tlio  developnirnt  of  refli.-x  m')vemGiita  is  diliicult  snH  uncerLaiu 
p  ihc  presence  of  the  hroiiu. 

I,  When  M'e  turn  lo  Ifae  leaching  of  diieaee,  however,  we  again  lind  that 
jlAex  uioveoients  carried  out  by  the  cord  or  by  paru  of  the  curd  are,  on  the 
thoJie,  seauty  and  simple. 

r  In  sonie  tUtgtm  of  oortain  diseases  of  the  spinal  cord  extensive  retles 
koYUiMat*  are  wilDCMed ;  but  these  are  not  purposeful,  ouiidiuated  move- 
MDlM.  such  as  have  been  described  ahore  as  occurring  iu  ttofc*  and  uiniu- 
balaaiUr  ex|)erimental  inlerfereuiy>.  but  rather  were  ezagf^nilious  iif  ilic 
(unpler  reflex  morcunenls  iriinmeecl  wIk-o  the  nerTOUS  ayatcni  ii  intact.  In 
Hirr  of  paraplepa  (such  being  ih«  term  generally  uited  when  diiNHuc  or 
Injury  has  cut  oHT  the  cord,  generally  tite  lower  juaii  of  the  cord,  ttoot  tlie 
brain,  so  that  the  will  cauuot  briug  ubout  niuv«au)ots  in,  ud  the  mind 
Serires  no  senmiiJou  from,  the  parti«  belon  th«  hvion,  the  legs  for  iiuUiice), 
it  swnetimo  happens  that  contact  with  ibe  iM^dclolhcs  or  other  external 
objects  sets  up  from  time  lo  lime  rhylhniieully  re{M;at«)  inorcmeiila,  the  logs 
lM>iu>;  aliernatelT  driiwu  up  and  llirust  out  it^iuii.  And  an  oxaf^raiion  of 
(be  "  kim'jerk'  i>r  ol  her  "  tendon  n;(lexv«"is  a  very  cummon  symptom  in 
Wnain  «pinul  di»cu>i-9.  Il  tit  nirvly  if  ever  ihul  reflex  moroments  of  a  reully 
puiuplicBie'l  choraoLcr  arv  oliwrvii].  Mureovcr  clinical  experienoe  shows 
tliat  in  mau,  whm  a  portion  of  the  I'onl  is  isolami,  reflex  actions  carried 
Mt  by  iDeMW  of  tfant  ]H>rtioti.  so  far  from  l>oiug  exaxgenilcl.  are  much  m'>re 
^MUluonly  exceodiitg  feehlc  or  absent  altogether,  in  the  cnseii  iu  which  the 
Bfayidolo(Hc*l  ocintiuuity  of  the  lower  with  the  upper  p<irt  of  tbe  cord  has 
DMO  brakeD  by  disease,  by  some  gmnth  invading  ihc  nervous  ftruoturea  or 


732 


TUE  sriNAL  CORD. 


suniulxtion.  that  the  lime  interveiiutg  Iwtwmn  tbe  aelioii  of  the  aciJ  m' 
tue  and  the  iritbdniwal  of  the  foot  U  very  much  prolooged-     That  is  lo  nj? 
ihe  MimulatioD  of  the  opiio  lobe*  ha?  cauMs  impuHee  Lo  deaceod  to  tW  cori, 
which  have  there  m  interfered  with  the  nerroiis  prooesws  eni>Ji;fed  in  canr 
iug  out  reflex  acltoas  as  jcrestlr  Ut  retard  the  generatioa  of  cfTervnl  in)pul«t. 
Of,  ill  other  wortb,  has  inhibited  the  reflex  action  of  tlie  cord.     And  sioulu 
rtaulta  may  be  obtained  in  uianimaU  by  aiiiuulatinj;  certaia  paru  of  lie 
corpora  '(uadriKeiuina.  which  bodies  are  homolui;ouk  ti>  th«!  uptir  iDba  a( 
tr*)g».    From  this  it  has  br«u  inferred  tliai  there  b  preM-nl  in  this  put  tf 
the  brain  a  npudal  mecbauisiii  fur  inhibitin);  the  ri-llcx  aetluiu  of  tlw  ipla^ 
cord,  lh<-  impulM*  dcMcndint;  from  this  mei-hanisni  to  tltc  varicitw  rcDini  of 
ri'Hcx  tictioa  bdng  of  a  specific  inbihltorv  iiaturv.     Itiit,  as  we  harr  alraattr 
tvvu,  impnlm  of  an  orditiarr  kind,  piiwiiij;  along  onlimiry  Ewit»iry 
nay  inhibit  reflex  action.     \Vc  have  <|iiol('d  iiisuuicG«  where  a  alight 
ulua,  M  in  the  pendulous  ni<ivciiii.>nta  of  the  .-inake,  and  whare  a  sir 
ttimuluK,  a;>  in  the  oim-  of  the  inii'turiliou  of  ilie  ili>g,  luav  produce  an  Is- 
hihitorr  rvsiilt;  we  may  add  tlial  in  the  frog  adeijuatciy  stroi))*  stiauG 
app)ie<i  to  any  alle rent  nerve  will  inhibit,  i.  r.,  will  retard  or  eveiinholK 
prevent  reflex  action.     If  the  toe«  of  one  kg  are  dipped  into  dilute  aiil|>hurr 
acid  at  a  lime  vfhen  the  sciatic  of  the  oIIkt  teg  is  being  powerfully  sliuiu 
lated  with  an  interrnptod  current,  the  period  of  incubation  of  the  n^'llex  aa 
will  be  found  to  be  much  prolonged,  and  in  soiue  caws  the  reflex  withilrawii 
of  the  foot  will  not  lake  place  at  all.     And  this  holds  good,  not  wily  tu  ihr 
comuleie  absence  of  the  optic  lobes  and  bulb,  but  also  when  only  a  (xirUto 
of  tlie  spinal  cord,  sutficieut  lo  carr}'  out  the  reflex  action  in  the  uaiisl  am, 
U  left.     There  can  be  no  i^uestion  here  of  any  specific  inliiliiii-rr  ccuim. 
atich  as  have  been  siipiiriM^  to  exist  in  the  optic  lob<p.     ButifUbclw 
that  iiihibitiiio  of  reflex  ui-Iidu  may  he  brought  about  by  iaipubca  whidi 
are  not  In  tbeiuMlvu*  of  a  >]>eeitii'  inhibitory  nature,  we  may  hesicate  w 
aooejrt  the  view  that  a  ti|irciat  inhibitory  mechanism  in  the  tenM  of  not 
giving  ri»e  to  ttothing  but  inhibil')r\-  impulses  a  prewnt  in  tlie  optic  l->to 
of  n-oga.  and  after  removal  of  tb<-  brain  that  the  exalutiou  of  reflex  *c- 
lioDM  which  is  manifest  is  due  lo  tlie  withdrawal  of  nch  a  spccitic  inhibiwt 
inccbanism. 

Tha  prtMiicc  of  the  brain  does  obviously  pnotuQi'  an  eilect  which  may  I' 
bnadly  spoken  of  as  inhibitory,  and  a  specilic  action  of  the  brain,  lo  is 
tlhn  of  the  will,  may  stop  or  inhibit  a  s|>ecific  retlcx  action ;  bat  we  noit 
not  iu  thrac  malterre  be  lod  loo  much  away  by  the  analogy  of  ' 
and  limited  cardiac  inhibitory  mti^nnism.  There  we  hare  ap| 
deal  with  tibrM,  whoee  exclusive  duly  it  is  to  convey  inhibitory  li  , 
fixioi  the  bulb  to  the  car<)tac  muscle,  and  inhibition  of  the  heart,  at' bsM 
through  nervous  iofluencci,  it«xc)usivety  carried  out  by  them.  Bui  ainuij, 
in  Btudving  the  nervous  tneehaBism  of  rMpiration,  we  have  seen  reasw  lo 
think  that  atrereiit  impulwa  pasring  along  the  same  nerres  and  prabik>? 
along  the  same  libreit  uiay,  according  to  circurostancee,  now  {nliihit.n(i* 
augment  the  respiratory  centre,  and  nave  thuA  been  le<l  lo  speak  «f  ■>' 
hibiutry  impulsw.  that  is,  impulses  produoing  an  inhibitory  vd^'l.  Sf*'< 
from  specific  inhibitory  flbrea.  In  the  complex  working  of  lbs  oMiUil 
nervous  system  we  may  still  more  expect  to  come  across  similnr  instaaoa^ 
the  same  channels  serving  as  the  path,  either  of  iuhihitiou  or  of  aatfM*'*' 
tion.  In  all  probability  actions  or  proceau^.  which  wc  may  apoM  <f " 
inhibitory,  do  play,  as  indeed  we  ahall  sec,  an  important  pari  in  the  f^i^ 
work  of  the  central  nervous  system ;  in  all  i>rohahility  many  uf  tbr  |<^' 
nomena  of  nervous  life  arc  the  outoMno  of  a  oontesl  between  whsl  "  "^1 
call  inhibitory  and  exciting  or  aiignienting  forces:  but  in  all  pmbsbl^i, 


bat  we  »w 

riha^iy 

ppan^^H 

>ryuiM»l 


TIIR    RKFI.KX    ACTIONS   or    THK   SFI3IAI.   L'DBl). 


rsi 


nj  to  ouea  of  |innipl«Riu  railed  ttv  nvciilcdlul  orrabio^or  nreniDoeof  tlic 
corA.  The  Kiircity  ol'  wt-l  1-rtinrkei)  reflex  aciioiiB  iii«Dliij|ied  itbovc  ns  cbur- 
atMriltic  "f  lurh  mKi'.  mtiy  {lerltiipa  be  >)ue  lit  (be  Ihct  tbat  the««  diaonleni 
tfantiilUm  |>n-v<til  ihr  iialieiit  living;  Umg  eimugh  for  ibe  wparal«d  cord  to 
nivivrr  ibi-  liHiili')ii»  u'lui-h  piMjH-rlv  bebnijj;  Id  il. 

;  594.  /jij'pi'.id.in  '-/  ivyff^  arlioii.  Tlie  relU-x  nctionn  of  the  npinul  cord, 
likf  i^Imt  iit'i'v-iu*  notimu,  iiiuy  be  ditnlly  or  ]iurtiiilly  iiihiliiUM),  ibKt  ii  to 
Mty,  niity  lie  iirr<«i4.''l  or  hirkkml  in  iheir  (kvclopmciit  by  iinpiiltKui  reaching 
th»  OHitn-  wtiili'  It  i>  ntri-iKly  iii  vdion.  Tliii*.  it  ibc  body  of  a  dvcnptMtM 
I  ite  dlbiwdl  i»  bung  ilonti,  »lun-  rhytbniic  pfiidiilout^  mOTemoito.  which 
tr  Id  bi-  Tvttvx  in  nnliirp,  eo'in  inakr  ibeir  ii|>pctimncc.  nnd  these  miir 
*  while  iirmt€<)  by  tlight  siinuilntiou,  tii<  by  ^nlly  stroking  the  tail. 
We  h»vc  nlready  eceii  thnt  th«  action  of  »iich  norvous  centres  aa  the  resjit- 
ratory  iind  VHsomotor  c«DIrf«.  which  frcquetitly.  ut  all  events,  is  of  a  retlex 
nature,  nwy  be  either  inhibited  or  nugm^Dted  by  alferent  impulses.  The 
uticUirition  centre  in  the  ntaninial,  which  is  also  InrKely  a  reHex  oeotre,  may 
he  easily  inhibited  by  impiilaai  [tassini^  downward  to  the  lumbar  cord  from 
the  bruin,  or  upward  along  the  sciatic  nerve*.  In  the  case  of  dogs,  wbii*r 
ipinal  cord  has  be^n  divide«l  in  the  tboracii?  regioo,  micturition  set  up  ax  a 
redcx  act  by  Hmpl«  preduire  on  the  alidunieu  or  by  «|MugtD^  the  aims  i#  at 
oooe  atoiiiKil  by  ^baqdy  pinching  the  skin  of  the  kg.  And  it  ia  a  iimtt«r 
of  Gonmou  experience  thai  tn  nmn  miituritioii  may  lie  suddenly  checkod  by 
an  MDOtton  or  other  eer«bnd  rvenl.  The  erection  centre  in  the  lumbu'r 
mrd,  also  iu  large  ineiwure  a  rt-tlex  ceulre,  la  MBiilarly  ausoeptible  of  Iveinf; 
iahibiied  by  impulns  rvschinfc  it  fri>in  various  tourcefl.  And,  indeed, 
many  niniilar  initanceti  of  the  iiihilHlion  nf  reflex  movtnicnt*  might  readily 
be  (lunteil. 

tS;vcral  nppan-ni  instaiicos  of  tJir  inhibition  »f  redes  nets  arc  not  really 
•uch :  iu  these  cn*cs  all  the  nervous  prijce«««  of  the  act  may  take  i>lace  in 
their  entirely  and  yet  fail  to  produce  their  eH'ecl  un  account  of  a  failtim  in 
Ibe  muKular  part  of  the  act.  Thus,  when  we  onrselvee  by  an  effuit  of  iho 
will  (top  the  reflex  moTemeiit^  which  otherwise  would  be  produocil  by 
ticklioR  llie  soles  of  the  feel,  we  acliieve  this  to  a  large  extent  by  throKing 
viilunlanly  into  ndion  c«rtain  inuscke,  the  coutnictions  of  which  antuj^onti* 
the  aclioD  of  the  muscles  eDf^aj^  in  carrying  out  tiii?  reflex  inovemeDU^ 
Hut  it  may  be  doubted,  fwn  in  ibtve  niseis,  whether  inhibiiiou  ■*  alwai,-*  ur 
wbdlU  111  lie  explained  in  ihix  whv  ;  am)  certainly  in  very  many  insiancrs 
ot  reflex  inhibition  no  hucIi  muscular  autax:i>ni*ni  t*  prMi-ut,  and  the  reflex 
art '»  cliccked  at  ii»  nervoua  centre. 

When  the  bniin  of  a  frog  is  removed,  and  the  efftctn  of  nbock  liave  pttsfvd 
away,  reflex  actioiu  arc  itcvrlnpi'd  miii-h  more  readily  and  tn  a  much  ^'reater 
ilcgrce  than  in  lliv  eniin-  anininl,  ami  in  niamuiais  also  retleJC  rxd  tain  lily 
bas  Iwco  obitrved  to  In-  increa^cil  by  rvinoval  of  the  o-n-bral  hemitpheree. 
This  euggwu  the  idea  ibnt  in  the  inlii<-l  nervous  system  the  braio  is  tiabilii- 
ally  exerting  wme  influcnci-  un  the  spinal  c^tril,  lending  to  prcviiil  the  nor- 
mal devi'lonment  of  the  rijiiniil  reflex  actioitf.  .\nd  no  kani  by  experiment 
llut  simulation  of  certain  jinrts  of  the  brain  ha*  »  rrmnrknble  cfled  on 
rettex  action.  If  a  fro^,  front  which  the  cerebral  hemispliorrs  have  been 
reniuve<l  (the  optic  lobee,  balb,  and  spinal  cord  beinc  letl  intact  i,  tie  £u»- 
pendetl  by  the  jaw.  and  the  toes  of  the  pendent  legs  Be  from  time  to  tinie 
dipped  into  very  dilute  Buljihuric  acid,  a  crrtain  average  time  will  be  found 
lo  elapse  between  the  dipping  of  the  toe  and  the  resulting  withdrawal  rif  tlie 
■  Jbol-  If,  however,  the  optic  lobes  or  o|>tic  thalami  be  stimulated,  as  hv 
putting  a  cryalal  of  sudium  chloride  on  tbem,  it  will  be  found  ou  repeating 
ihe  experiment,  while  these  structam  are  still  under  il<e  influence  of  tl>(* 

U 


a 


734 


Tllb  81'I.VAb  OOBU. 


of  Ibe  body  as  tb«MirraeoMiniulal>on  of  which  euuls  lh«  set.  the  liiMUk 
up  ia  lc»  tban  when  the  movenKnt  ts  on  tbe  utlier  side  of  the  Kxly.  mild 
beio^  made  for  tbe  Inif^th  of  central  nervous  mailer  involved  in  iheivot 
tlial  u  to  wv.  the  ceiilral  ujieratiiMU  of  a  reflex  act  are  proMji^ted  mom  i 
idly  aloii^  tlie  cord  tban  ncn^s  ibe  cord.  Tbe  rajiidity  of  tbe  act  vari«.j 
ootine,  with  Ibe  coDditi<in  tt(  the  xpiual  cord,  the  act  being  grvaily  pruloaj 
wheii  the  ennl  becumiw  exhausled  ;  and  a  ^irnilur  delay  baa  been  •rl«efT 
cwMS  of  dbe«»e.  The  time  thus  occupied  by  purely  reflex  acllon»  muM  D'4 
Im  ct>iifoumlei)  with  the  iuicrval  required  when  tli«  changes  taking  place  in 
ihe  ciriitral  iktvouh  nyxlcm  arc  »f  a  more  cuniiilicatt^l  nature,  and  uiorevr 
lewrtiMinrlly  involve  inc«liilo]>eratioiin;  of  the  lalti^r  wcxhall  !^>c»k 


TbK  AlTOMATIC   ACrlOXS  OK  THK  HpIKAt  CoRIK 

S  M6.  We  Bpeak  of  an  action  of  an  organ  or  of  a  living  bo<ly  as 
tpoulaneoua  or  automatic  when  it  apjveare  to  be  not  iru mediately  due  I 
enanf^n  in  the  cireuniatances  in  ithich  tbe  ornn  or  body  t^  placed,  hut  i" 
be  thiTCNult  uf  chanf^amtDfi;  in  ibeorj^n  or  body  itseifand  determiii''  *<- 
cauK»  oilier  than  the  influences  of  the  circomaiancee  of  tbe  niomeiii.  ' 
Hulomaiic  actloua  are  of  a  i-uutinued  character ;  ulbers,  like  tlic  beat  iii  \i>' 
hi-itrt.  »rc  repealed  in  re^lar  rhvthm :  hut  the  mont  Mrikiuji  auiuntatic  or 
ti<>iii>  of  the  tivinz  bo<lr,  lhuc«  which  we  altrihiiU-  tu  ihu  workinn  of  the  iriC 
and  whirh  we  mil  vi)luularv  or  vnlitional,  are  charucti-rixcl  by  itieir  app' 
rtot  invgulurity  and  variaob-iiou'.  Such  vaniiblu  automatic  aclMioi  WS 
ibo  rauat  «lrikine  feutiin-s  of  an  iiiiaol  iH'rvuui>  ]i\i>li'(u,  but  arv  roMpinwiuIl 
nbKnl  fioni  II  Kpitial  cnnl  when  ihc  hraiii  has  been  removed.  j 

AhraiiiU-n>  I'ro^  plncnl  in  a  enndition  of  «Ku^etoci]iiilibriun)  innhichl 
(timuliiit  is  brought  lo  hear  on  it,  prutwtnl,  for  lUnlaiuii,  from  ■iidikii  t^p 
chaog«#  in  tcmjHTiitiire,  from  a  lua  nipitl  cva|>i>mti<iM  by  iIh^  -kin  ajxt 
lik«i  remaiiM  perfectly  roolionlno  uuiil  it  dt<-s.   Such  ap|Mirenily  BiHiQiaiiMBt 
nmremenle  a»  are  occaniuiially  wiliinMit  arv  m  tiltw  and  itel(h>ni.  ibal  mt  rti 
liardly  do  othcruioo  than  attribtito  Ihcm  to  eome  rtimulu*.  inicrnal  <>r  ru* 
nal,  which  has  cet-aped  observation.     In  the  mammiit  idog)  uA^r  iliviiiuut 
tJie  npinal  cord  in  tbe  doraal  regioD  irgulur  and  appiin'ntly  ^[NiDUnn 
moveme Ills  may  l>e  obwrvcd  id  the  parta  gov«riic<l  by  the  lumbar  curtl.   VH' 
ibe  animal  has  thoroufihly  recovered  iVoni  the  oixralioti  the  hitiil  liiutH  n.K^ 
remain  (]uiet  for  any  lon^;  period  ;  ibey  tnov«  rcslleasly  in  various  wnyi ;  ta 
when  Ibe  animal  »  suspended  hy  llie  upper  ("art  of  the  body,  the  |h-wI« 
bind  limfaa  are  cunliuually  being  drawn  up  and  let  donu  aj^ain  n  itb  a  aito*- 
onoua  rhythmic  reKUiarity.  sugf^ive  of  autuiuulic  rhythmic  diicbnii.t»fn<ii 
tbe  c«)iral  mechanisms  of  the  conl.     In  the  oewly-bom  maiumul  ti»>,  »f 
removal  of  the  hraiii,  movement  apparently  BpoDtaii«ouB  in  nature  an*  Tn 
ijuenily  observed.     But  all  tbeats  movements,  even  when  moat  hiiftily  ilerrt'l 
oped,  are  very  ditferent  from  Ihe  tuoTementv,  irre};ular  and  variable  ia  i^' 
Mcurrence  though  orderly  and  jniirpoM-ftil  in  tbeiri-baracter.Hhich  uemvp 
niie  as  dblinctly  voluntary.     Evcii  admiltiuj>;  ihat  some  of  tbo  moiTOHi"* 
of  tl»  brainleaa  mamnaal  may  reacaible  voluntary  nvuvtrineutii  in  w  hi  u 
tbey  are  due  tu  rbangca  leking  \t\wo  in  the  «|<inai  i\>nl  it.ielf  indci>eivi<n>  'J 
the  immHialeinfluenceof  any  »limiilu>,  we  are  not  thereby  juHlirictl  iii<)>*^' 
ins  of  the  Kpinal  cord  ait  developing  a  will  in  tbe  mubo  lluit  wo  uitriliiC, 
wiTl  to  the  brain. 

i  567,  in  tiic  COM  of  tJie  beat  of  tJio  beari.  iIm  automatic  rbyUiaaf  ^^ 
charge  of  energy  apiM-ara  to  be  exclusively  the  outcome  of  the  nulK*^' 
uulriiive  cliHugcN  taking  place  tn  Ibe  cardiac  FUbattiDce.    llie  boat  ■*,' ' 


THE   BKPLKX    ACTIONS  OF   TIIK  STINAI.  COUD. 


72Z 


I 


I 


I 


I 


» 


mimt,  wv  outHit  ntltor  to  Mck  for  t)i«  cspJiLnaiion  of  how  vofM  iRi|Hil«M 
inbibk  Uie  IMM  of  the  lienrL  Uj:  refviviico  tu  t)ic  inhibiiury  phviiiomcDa  of 
Zbe  ccDtrul  ncxrou)  ajtXcm,  (han  Id  Ktivmpt  to  cxpluii  ihc  Inilcr  by  th« 
JitU*  wr  kuoit  nf  ilii'  fonuor.  At  prtw-nt,  hciwcvvr,  nv  iiiii»t  br  ontctQl  willi 
%.ht  &ct  tlint  rxpcnriM-nlit  <>n  niiimnls  xlioir  t.liiil  thi?  Itniiti,  not  onlv  liv  Eotue 
au^itiu  or  othtr,  iimy  iuliibil  piirticular  vpitial  mHes  tnnvrnteiili,  but  aku 
linbiiqallj  cxc4viiH9  n  rtviminini;  iiifliii.-nc«<  on  tho  rvAox  nctiviu-  nf  tli« 
i^liitlr  rant,  though  w«  nrr  iiiinnk-  to  stale  clearly  bow  tlii»  inhibitioD  U 
ourivd  out. 

W«  uy  "experiment*  mi  MiimaJs."  because  though  wo  know,  aa  stated 
nlhtw,  by  an  appeal  to  our  own  conaciouaneM,  that  an  action  of  the  hraiu, 
an  iffrorl  of  the  will,  may  stoo  a  parlii'ular  r«tlox  act,  we  have  no  evideuce 
thai  in  tnaa  aeparatioti  of  tne  oonl  from  the  brain  leiid^  as  in  aniiuuls,  to 
lie^fateoetl  reflex  activity.  In  diaeases,  or  injuriea  to  the  cord,  retlex  actiooit 
M«,  M  vre  have  said,  sometilBM  eiagRCmted,  but  it  is  podsible,  and  indeed 
pnliabte.  that  (he  increaae  ia  dne  to  the  morbid  proceasee  produutog  a 
crMtvr  irritabiliiy  of  the  cord  ilaelf,  and  not  to  the  withdrawn  of  any  iii- 
ntbilory  influeooes.  In  many  caaea,  in  perhaps  the  greater  number,  uo 
exsggeraiiou  but  u  diminuiiuu  or  even  abaence  of  reflex  activity  is  obaerved; 
w  muob  BO  ihai  could  we  tru»t  explicitly  to  cliaical  experienoe,  we  ahouUl 
ht  locliaed  to  conclude  thai  tlie  sountiueas  of  apinal  relex  action  iu  man 
van  ilu<-  not  to  any  preoccupation  of  tbe  cord  by  influeocea  praoevltiiL'  from 
a  iloiniiianl  brain,  but  tu  an  iuherenl  paucity  of  ajMnAl  reflex  imvliuui»iua. 
ilut  «e  have  already  Mid  all  we  have  at  present  to  nay  oat  tim  point. 

t  595.  7%e  limi  rfriuirittl  j'or  rejtri  aetiatu.  When  one  eyelid  iii  stimulatud 
with  a  sharp  clectmitl  iiiock.  both  L>yelidit  blink.  Hi;iiui?,  if  the  length  of 
time  iiitervvning  b^lneen  the  siiniulatiim  of  the  ri^ht  eyelid  ami  ihe  ntove- 
nient  of  ih*-  led  eyelid  Iw  mi'murw),  ihi>  will  give  llie  total  lime  rwjLiired 
for  tl>e  various  proccwm  which  make  tip  a  reflex  action.  It  has  been  found 
to  Iw  from  0.0t'>li2  to  0.0578  aecond.  Dediicliog  from  tbmc  figuroe  the  (in>e 
required  for  ilie  passage  of  allcrcnt  and  cfTiTent  impulses  along  the  lifth  auid 
facial  Derves  tu  and  from  the  bulb,  and  for  the  latont  period  of  the  cun- 
Iractioo  of  tbe  orbicularis  muscle,  there  would  remain  O.Oood  to  U.0471 
■mnnd  for  tbe  time  oonsumod  in  the  cenlnil  opemUoiu  of  the  redes  act. 
The  odculations,  however,  necessary  for  this  reduction,  it  ne«d  not  he  said, 
an  opco  lo  aounMS  of  error ;  moreover,  the  r-Hcx  act  in  question  is  canied 
nut  by  the  bulb  and  not  by  the  spinal  cord  proper.  Blinkinf;  thiu  produced 
is  a  reflex  act  of  tl>e  verr  simplest  kind ;  but,  as  we  have  seen  iu  the  pre* 
eclin^  pap*,  reflex  act*  differ  very  widely  in  nnlun?  and  character ;  and  we 
aciHirilioglv  find,  as  indeed  we  have  incidenlutiy  mentiuneil.  that  the  time 
inken  itp  l>y  a  twUex  nnjveioent  varies  very  largely.  This,  indeed,  b  »<*ii  in 
hlinkin^'  itaelf  Wlieu  the  blinkini;  is  caused  not  by  au  ek-ctric  ahock 
appli4-d  lo  the  eyelid,  but  by  n  Mash  of  lijjhl  falling  on  the  r«uiia.  in  which 
case  complex  vibual  proouMes  are  involved,  tbe  tinte  is  didiinotly  prolonged : 
moreover  the  reMilta  ia  difilBrent  experimenla  ia  whiob  light  aervea  a«  tbe 
•timulua  arc  not  nearly  >o  uniibrm  as  when  tbe  blinking  ia  oauNd  by  uinm- 
laliun  'if  ibe  evelid. 

In  genenil  ii  mar  l>e  said  that  the  time  required  for  any  reflex  aot  variea 
vtrj  Gouderably  with  tlic  strenglb  of  the  Mimulua  employed,  being  le*  for 
the  rtroi)g«r  stimuli ;  tliiii  we  should  ex|Nii:t,  seeing  that  the  elldreni  impubea 
nf  tbe  rettex  act  are  not  nimply  aflcreol  impulMH  truiiimitt«d  through  tbe 
ceatral  organ,  but  m*ult  from  internal  chaugua  in  the  central  Oi]gan  Harl«d 
by  tbe  afllsrent  im|MilM  or  impultMH;  and  lhe«e  int«rniil  changea  will  aatu- 
mllv  be  more  intrikie  ami  in>ire  rapidly  aflccteil  whi-n  the  aflbrent  impulsaa 
arr  strong.    It  i*  statul  lluil  nbeii  ilie  movement  induced  i.t  on  theaame  sidB 


7SS 


rns  sri.vAL  t-oRU. 


to  »  qumiou  nhii-h  Iins  Iweu  tiiucb  debnteil.  anil  nhicb  ha*  nu 
ind  iiD|H>rtiiiit  bearJD^a,  nani«ly.  Ui«  (jiietilHui  Kh«lti«r  llio  *mr 
cUeA  au  automatic  fuDCttoii  in  iiiumiMiiiiiig  »  lonu  ot'  iIh'  nki-lflml  muKinv 

TheuueMion  ia  noi  one  nhJch,  ttki!  ibii  rue  i>f  BrK-riiil  tunc.  <'«ii  be  *tKM 
off  bana  by  a*iR)|ile  cx)ienniufli.  Moat  obaerTem  nm'c  that  ibr-  (n,-ii'>Q  <'i'< 
motor  nerre  dot*  i)»l  )inH]iii.i>  any  clearly  rvcogprxiiblt'  imiu(sliai«>  Iriir'  -'- 
iDg  ttf  a  muscle  nipplinl  by  the  m-n-^.in  ihniiHRKr  way  ibiil  i>ti:1toii  •■(  ■ 
COnitriclAr  nerve  iiti<li>iibl<slly  giriin  riMi  l»  n  rvlitxatittii  of  tbo  miMcutitr  i  i<i" 
Id  tlw  art<:ri4vi  govcnu'tl  by  it ;  anil  it  lia»  Ixi-ii  infermi  from  tbi»  tlutt  -l-  -  i' 
lono  don  m>t  I'xtwl.  But  thrrr  iirv  M-vi.Tal  AicIm  la  bo  takrn  iniu  cntKiden- 
lioii  hnftin-  wi'  (7IIU  oome  to  a  jiiK  ilcciKion. 

Tbc«k«lcial  muicln  bare  l>n-ti  ii(«rrib«4l  a«  living  pIao«d"oR  iIw*iTftrIi" 
In  iIm!  living  body.  If  a  riiim-Io  be  out  away  Irom  il«  atUicbmcnie  ai  nA 
rod,  it  »lu>rf<D»  ;  if  it  bo  cut  ucroee,  it  gapn.  lu  olhrr  word*-,  the  mii»cl<-  a 
the  living  body  p<«wwra  a  latent  uadtacj  to  shorten,  which  ie  continuk^T 
baiog  count  era  dfd  by  ile  ditpmition  and  ntiacbmerKF.  In  Miidying  »<»■ 
cular  cootrHctioo  vie  hbw  (S  si)  that  the  shorteoing  •>!'  n  ountraction  ir  id- 
lowed  by  a  relaxation  or  return  to  tbe  former  length,  both  the  coiitracii'o 
and  relaxation  being  tli«  reault  of  moWuInr  elMii)Re«  in  lite  living;  miiwulti 
mibMance.  We  have  now  to  extend  oiir  view  and  to  ivco^ize  that,  apart 
from  ibeoccuirence  of  ordinary  contraction*,  molecular  citan|[ea  are  by  mnnt 
of  uulrilive  procraaea  continually  voing  on  in  lh«  muscle  iii  such  a  way  ital 
lite  muKle.  ibougb  continually  on  we  atrrtdi,  doea  not  pernianentlv  leu^n. 
but  retains  Ibe  potior  to  Hhorten  upon  removal  or  Isaening  uf  ilie  strMi^. 
and  coDvenely  tlioi));h  piwMeunj;  tbia  |)oner  of  shorteDiiig  giermits  jtwlf  m 
lengthen  when  tbe  .ntrelch  is  increased.  Id  tbix  way  tlw  mu»cle  is  able  f 
accommodate  iinelf  to  variations  in  the  amount  of  stretch  to  which  it  is  fnai 
lime  to  time  subjected.  When  a  tlexor  muscle,  for  instance,  contracts  \U 
autaguiiiMiecxIcuiHir  niufrle  is  put  on  an  increeMd  stretch  WMi  is cortte]Miai- 
ingly  Iriigt iH'iinl ;  when  the*  cimtrnctiun  i)t'  tbe  flexor  puma  olF  tlw  nteDMr 
rvlnrnii  to  ils  pn-vioun  leogtli  ;  and  to  in  othor  inylHiices.  Thufi  by  riTtiiv  'i 
cerluiii  cban^rn  within  ilwlf  a  mutclr  maiuluinn  what  luiir  I"-  called  ll*  auo 
nl  Itngth  in  the  iKnly,  alwuya  reluming  to  that  UHtuml  Icn^h  liolh  >D^ 
Mug  uiorienH  nnd  after  being  rtn-tcbed.  In  ihi*  ihr  muiH-lii  d<n»  mi  wm 
ihnn  do  lh«  niher  liiutKV  of  Ibo  IhkIv  which,  wiibin  liniiln.  retain  tfcatt 
natuml  form  under  the  varied  Mn-w  and  rtrain  of  life ;  htit  tbe  pre| 
eonamcuoiis  in  the  miiide:  and  it»  elfeols  in  ■kclclal  mu«cJ«  cor 
clovelr  to  Ihow  of  arterinl  tune,  that  we  may  venture  to  ■peak  of  it  i 
lal  loite.  Indeed,  (be  molecular  changes  at  the  bottom  of  both  are  pinb 
the  eamo, 

These  changes  are  an  exprenion  of  the  life  of  the  muscle ;  they  dJMff**' 
when  the  muscle  dies  and  enters  into  rigor  monia ;  and,  moreover,  dur 
life  iliey  vary  in  intensity  so  that  tbe  "tone"  varies  in  amount  acoonllngi 
the  nutritive  cbaDgea  goinj^  on.  We  have  seen  reamu  to  believe  thst  t* 
BUlrilion  of  a  mufcle,  as  of  other  tirauee,  is  govcrened  in  wine  way  hvii, 
central  nervous  Bvstcui.  We  eaw,  in  treating  of  muscle  and  nerve  iSft'JI 
that  tbe  irritabiltly  of  a  uiUM'te  is  markedly  affected  by  ilte  *«li(iB"(iB 
nerve,  i.  ".,  by  ocvcrani  e  jniin  the  <M;»tml  nervous  sysieni ;  aixt  again  1 5  *''^Jj 
in  sneaking  of  llie  wt-callcil  lni[ibic  action  of  the  nervous  system,  we  rtff^'^ 
to  cbaiigt-s  in  the  nutrition  of  niuw)™  occasioned  by  diimws  of  tbe  anvfail 
M'stem.  And  vX|irricnoe,  es]iecial]yctiuii-al  experient.'c,  showa  ihni  the  vi''*'' 
live  changes  which  dctcrmim-  tone  are  \-cry  oIom-Iv  depeiident  on  a  H"* 
action  of  iTie  cniinil  wrvoui'  nysii  in.  When  we  hamlle  the  limb  of  a  bcal'"!' 
man,  we  liml  ihmt  it  oirt-r«  a  n-tlain  amount  of  resistance  to  r"BaT<'H'^ 
ueuis.    This  n-sirtanw.  w  hieb  is  ijuite  independent  of.  that  is  to  lay, «»" 


I 


I 


Tim  Al'TOMATIO   iCTIOXS  Of  THE  SPISAI.  rORn.      72S 

nHidlRnl,  m  «»  havt  trta,  hy  D*rrvou«  ininulm>t>  n-nchiiig  iW  mrdiac  sub- 
MlBUni  along  certftin  ti<-rvvs:  btit  the  net  it  nl  (■xitU-ticv  of  ilii-  Iwit  u  n  holly 
inilvprmlctil  of  thifsc  pxlrnnooiia  inHurnt'cs ;  the  rhyllimic  ilUchiirge  cimtintiM 
whvii  ihfv  arc  piiiirelv  sltwal.  The  aulonintie  rhytlimir  iliiichnrec  of  n*f»' 
raiiiry  ini|i«l»c«  from  ihp  reBpiratorj"  ccntrv  \»  nho  AvpenAvni  on  inc  iiilrintiu- 
moWulHr  i-lian;^  of  the  <viitre,  iHmc  bdo^'.  ne  wc  have  nxn.  Inrgi-ly  <!i>t<'f 
otttieH  by  the  chaniot«r  of  the  bloixl  stivHinin;;  througb  il ;  but  tti  ibis  cum 
rxtrinsic  nerrous  impulses,  rracbin^  ibe  cMilre  nluti);  th«  v&{;ii$  and  iflb«r 
iwrve*,  |>iay  a  ruiiob  more  impiirtaiil  jiart  tban  do  Bimilar  inipulF^^  in  the  caw 
oTlbc  b*arL  Tliey  )ict  *o  molinually  ou  the  centre  and  enter  bo  Inr^^ly  into 
its  workiui:.  ibalwe  «re  cotnpelle^l  lu  reijard  llie  aclivity  of  the  centre  na  fed, 
if  we  may  use  lli«  wnrtl,  aot  ouly  by  ibe  iiitriiinic  inoleculnr  nutritive  pro- 
ctflMa  of  the  centre  ttAolf.  but  al»o  by  the  extrinsic  uerrrKtH  iuHueucta  whieb 
liw  inirt  (he  ivmre  fmrn  niihimi.  Tlif  aiiiomaliain  of  the  »piimt  card  as  u 
whole  rwifnibltsi,  in  this  rft»peiH,  ihnt  of  thi-  reK()iratory  centre  rather  than 
tJiai  of  ib«  Ill-art.  It  ban  for  ili>  bn^ix  duubiinu  ibt.-  iiiinunic  niolcctilnr 
(kMWW  of  the  gniy  mailer,  on  whi><e  riMnarknble  cniriilutiun  v/c  dwelt  in  a 
fiKVlmu  aectioD  ;  lh«  metaholic  evenl.*  of  lbi«  oulHlniioP  are  so  <>rden-il  ili  Xit 
gire  rtw  to  dtfichnr^tv  of  rni-rgv  ;  but  (be  diitchar^  ap^Mwrs  to  be  alsu  tnli- 
nutcljr  dependent  on  the  inflow  into  the  gray  nuitier  of  afferent  impuUes  and 
iDfluencfs.  The  iiorioiil  discJiar^  ofdTerent  inipuliH»  ttota  the  cord  ud< 
rioubtadly  lakc:>  plai-c  under  the  influeiices  of  ihnc  incoming  impubn;  and 
It  may  be  donbteit  whether  the  gray  matter  of  the  cord  would  be  able,  in  the 
■henicvofnll  afferent  impulK«.  to  gttDcrnle  any  «uttain«d  eeriw  ofdiscbarKn 
•>ul  of  it«  merely  nulrilire  iiitriocie  cbangea.  The  niitomntic  activity  of  ttie 
conl  u  fe^l  not  only  hy  intrinsic  nutritive  events,  but  al»o  by  extrinsic  tntlitenca. 

In  thi*  feature  we  may,  however,  lind  perhaps  tbe  resi-in  why  the  auto- 
matic cMvity  of  the  spinal  cord  is  so  limited  as  compared  with  thai  of  the 
brato.  Ill  «)>ite'if  eerlain  »trikiii;;  but  superficial  chanelen  of  wbiuh  we 
thall  jipeak  later  ou,  the  ^niy  matter  of  the  brain  pn^K^nis  no  hii«tob>gical 
feature*  to  diiri-ivtii  fmm  thuw  of  the  gray  matter  of  the  cord,  nii  to  jii*tily 
lu  in  cooHudiiig  that  ib«  one  in  capable  and  the  other  incapable  of  devvlop- 
ing  the  impulwA,  which  w«  call  volitional,  out  of  tbe  molecular  nutritive 
cliMlgO  of  il«  milMance.  \W  arc,  therefore,  led  to  the  coochuion  that  ihr 
Alllar  nutiinuitic  activitir  of  the  brain  indue  to  the  intriitMC  cbanpM  of  ita 
wMaiKv  lieing  «i  loucb  more  largely  nmiiitcd  by  tbe  influx  of  varimif  nlfr- 
iMt  impulse*  and  iutliieucce,  notably  lb<i«e  of  the  special  Mnses.  To  this 
•|iMetton,  however,  wc  obnll  have  to  retunt  later  on. 

ji  008.  In  treating  of  (he  vascular  syntcm  vro  saw  that  llie  central  nervoua 
•ystetn  exercised  ibriiugh  the  vasomotor  nervM  such  an  influeDcvon  the  miw- 
eular  coats  of  the  bloodvessels  as  to  maintain,  what  ire  spoke  of  as  "  tone," 
section  ol  vaao  consirict'ir  fibres  Icadinz  to  "  loss  of  tone."  We  mw  further, 
thM  arterial  (one,  though  normally  depemtenl  on  the  general  vasomotor 
centre  in  the  bulb,  could  be  kept  up  hy  ibc  cor«l  itself,  that,  for  instance,  a 
tone  uf  tbe  bloodraaselsof  the  bind-Iimbs  could  be  maintained  by  the  ianUted 
ilorto-lumbar  eord.  This  maintenance  of  nrlenul  tune  may  be  spoken  of  m 
one  of  the  "  aoiomalic  "  functions  of  the  spinal  cord.  We  have  ulao  seen 
that  plain  uiuricular  fibres,  other  tban  lhn«e  of  the  arteries,  notably  the 
flbrca  forming  sukincten,  such  as  the  cardiac  and  pyloric  spbiuciem  of  the 
stomach,  the  iipliinct«r  of  tbe  bladder,  and  espevially  tbe  Hpbim-ier  uf  the 
anu>,  iilsii  poMeas  tone,  and  that  tbe  tone  of  thuK  sphiiKten  is  alio  de- 
prmlent  on  the  sfdnal  cor-l,  or  on  some  part  of  the  central  nervoiu  mtem. 
W*  Deed  not  repeat  tl>e  dinctiMious  conceniitig  tlit*e  moehaDisms  and  other 

£i>f  the  sjnaal  ourd  exercising  an  automatic  inllaeiic*  over  rarioua 
we  Inve  refirrred  to  them  here,  since  they  serve  at  an  inliwluetioii 


728 


TlIK    itl'IN'AL   OOttH. 


ilufiii);  ilic  ]MTi<Hl  of  Mliock   nr»  liDtp  nad  toaalns.     In  lil^  wnmi 
nuiuml,  a*  «>'  linvr  •Atil.  tin-  i-flcirU  uf  sbonk  nrc  mucti  more  liutiiig 
thi-  cold-liLiocln)  iiiiiniiil;  iixl   in   tlir  ilog  the  tone  of  tlip  slfel<<tnl  mti 
r>-CiirnM  tmicli  more  nl'iwlv  ihun  in  iho  Cru);.     Iiii)i>ed.  when  tlt«  •livisioa 
l)ie  (yinl  tiM  IbIci-ii  fit.icr  low  lioarn  ihi-  «kf1eul  lone  returns  very  Blnwlj-.u 
niuy  \>e  niniulifle<l  very  fmhly,  or  cvvii   l>e  nbwnt  altof^Uter.'    But  iitii 
t'avurnlile  circumstHDees,  when  a  suflicieDl   Ien|i;th  of  coni   bns  hceii   l«A.  t 
fnirly  Honniil   lone  i)  recabiblulied.     In  mAo,  in  aecordnune  wttti   tlw  fi 
|tr«viously  lueDtioiKy)  (i  W£),  skeletal  loue.  wbicli  luu  beeii  Umt  thrnugh 
cuutiiiuity  of  tli«  oonl  bein^  brokeu  Iij  diseaae  or  acei<i«nt,  aji|>r«n  rarnljr 
ever  to  reiuni  fUlly  in  (Ik  ref(i»ui  below  the  l«rian. 

We  luav  tl>ert>foTe  o»  (lie  wliloe  of  the  evidenw  ouii«l>i<)p  thai  Um 
Ifiiaiii-e  <>r  skeletal  (<>ue  U  <>i>e  of  the  fuDctious  nt  the  cord ;  but  w«  amy 
Ttpeut  tbat  the  cuiulttitxi  i>f  tlte  cord,  un  which  ditfM'ndii  the  iwue  iVoin 
c<>ri\  ailing  rfl^mit  iirrven  of  tbi^  iiiBiienoM,  whntevor  tbinr  naiurr,  whtdi 
|>rodti<!r  loiti'  iu  tiM'  iniiaelp,  tatty  \m;  nud  imh'n)  ik,  in  itH  turn  (lopondail  oa 
xflervnt  im|iuL-H!».  ht  the  cue  of  tlii'  I'rog  iiu<>|4.>d  al)ove  lIh<  ton«  of  tbe  pM- 
denl  liniW  di»iip|K*r»  "r  i«  irrcnlly  U9«i-n«l  whCD  iho  p<i»ilprior  routs  uf  U»f 
sciatic  nervM  nrc  divi<l<,il,  th<iiif!h  llic  HDtvrior  route  be  [vIX  intact.  In  iht 
alaence  of  tbe  usual  tttn«in  of  nJfeTenl  iinpnlK-?  |)eMing  into  it,  the  cod 
oeaMfl  to  send  forth  th«  influences'  whii-li  inaintniu  tho  tone.  Henoe  Ihi 
maintenance  of  tone  jircwnts  mitny  imuli'gi^  with  a  reHrx  ai-iiun,  apecnitl; 
wlieu  we  reineinlicr  thai,  ns  ^laii^^l  above,  tone  poMce  itisemibly  into  coainu' 
tion ;  aud  it  may  be  seen  a  mere  matter  of  w»rda  whether  vo  apeak  of  lb* 
maintenance  of  tone  aa  an  atitontaiic  or  as  a  reflex  action  of  the  coril.  W« 
may.  Iiowever,  distini;uiBb  ihe  part  nlaye*)  by  the  afferent  impulM«  in  n»i*l- 
ing  ibu  c»rd  to  a  condition  in  which  it  is  capable  of  mainlainiujc  1(i«R'  ftvni 
ibe  pATl  played  by  an  aflereni  inipulae  in  cauaioK  a  reflex  ai-tiou;  in  tb 
ftinnertbe  action  of  the  aflVrent  iiupubta  seems  anatojtmia  loibat  of  a  »upj 
uf  arttirial  blixKl  in  mainiaining  an  adeiiuate  irritability  of  the  ncrvooii 
Hiance.  in  the  Utter  the  atfereut  itn|MttMa  lead  directly  to  a  divlmrs' 
energy.  Ami  it  in  c<mvcnient  Ui  dtilii^Mh  tlie  twit  things  l>r  ilifli-i 
naiuiv, 

<:  599.  The  cIoki  coniwction  between  tiaie  and  reflex  action  !s  illaitraiMi 
by  the  ao-calletl "  tciHlon-i)lHinonM>na."  uhich.oii  the  one  bnnd,  arc  cNwiilrrtd 
aecaen  of  ordinary  reflex  action,  niid.on  the  other  hand,  hnve  bi^-n  reKartltd 
B£  exemplify iiig  a  «prcial  inHiienpc  of  the  npinal  rairil  tm  ibv'  irritabttilrt^ 
the  muBcW  U  is  well  known  that  when  tbe  let;  in  )>tace«l  in  mi  esity  pw- 
tion,  realini;  for  initiinoo  on  the  other  leg,  a  sbarp  blow  im  the  ptttellar  trMta 
wilt  csuae  a  sudden  Jerk  fnrwartl  <d'  tlu-  log.  brought  uInxK  bv  a  eonlraftlto 
of  the  quadricepe  femoris ;  it  is  iieceeKirA'  or  at  leaal  deeirnble  liir  a  pn^ 
development  of  tl>e  jerk,  that  the  twidoQ  (and  muscle  t  should  be  euaieohU 
on  the  stretch.  Similarly  the  muaclM  of  the  calf  may  be  thrown  inloadiwi 
by  tapping  the  teodi>  Aehillia,  put  somewhat  on  tbe  etretch  by  flexion  of  A* 
foot :  and  in  some  cases  the  same  muacica  may  be  mule  to  execute  a  seriM  of 
regular  rhythmic  con  tractions,  called  "  clonic  "  ouniractions,  by  miditcaly 
preaung  back  the  sole  of  the  foot,  so  as  to  (Hit  thetu  on  the  strctoh.  TIm*'- 
and  other  inntanoea  of  a  like  kind,  at  firat  sighl  apiiear  t»  be,  and  Indeol  sf* 
by  many  obaerven)  mainlaiuetl  to  be,  oasett  uf  reflex  aeiioti,  due  to  slbfl 
ini)>iitM«  olurlc)  in  lliv  tendon ;  hence  iher  have  been  frequently  spokM  '^ 
a.1  "  teiidon-n'tlcx."  Other  olwervcrt  maintain  (hat  they  are  not  rtnex.  I>0< 
duo  to  dircMi  «limuliili<in  of  the  muscle*,  the  vibraiiotu  i*rt  up  in  the  nMt" 
Ices  tense  t^'udon  Ixing  iran.'tmiltcd  tothenniHcle*,  and  mi  (bmning  llie  IsU*' 
into  contractions.  The  chief  ar^um^^nt*  apiinsi  their  being  reflex  arf  >b*l 
the  interval  Iwlwwu  the  tap  and  the  iMnlni«tion  in  very  short  i dO^l »« tH" 


rtvni 
tllx      I 


rn»    AfTOMATIC    ACTIOXS    OK   THE    SI'lNA'fc   COBD.      729 


Kinil ',  ubiirtrr  lliaii  the  i>nliiinrr  iiiUTvnl  "f  n  rctl"x  iflioii  <*$  51^5),  and 
It  ll>c  niovt-roi-iit  i>or*MlJ>  nlliT  Mvti<>ti  of  llw-  Pfrvcs  if  the  ttnAria.  The 
W  •rgttDM'iil  i*  {H-rhnp*  nut  u  vrn-  vlroiij;  on«.  nn>l  iW  wmnil  mil}-  Iw  met 
\  mppodnft  tlml.  iii  oudi  n  cbm-  r1  If  ivtt,  if  not  nluiirs,  ibo  rcA<-ic  a^rt  rNilly 
|ta>  in  tlw  tniuch)  Iwiug  ntartinl  !ii  it  by  itic  vibrations  lTnn«iDiU«<)  to  it 
tog  tht  iradon. 

put  •nn  if  wc  mtmic  that  ilip  iiiovcnicntii  nrc  purely  muMalar,  iinriM 
il  earrial  out  in  the  niii«cl<>  wiili»ut  tin-  help  of  thu  umal  rcfl«i  cliniu  of 
kmtt  iu){Hil#es,  spiiinl  centra,  and  elTeivnt  itupiilees,  we  niuM  nt  th**  Mine 
ba  admil  llwt  they  arc  close  dependent  on  the  integrilY  of  the  spilUll  cord 
d  at  the  ronD«ctions  betireeu  the  card  and  the  muede.  In  the  C«M  of 
liDflU  they  disappear  when  the  spinal  cord  is  dealroyed,  or  the  nerm 
Ing  to  tlte  niUKleB  are  severed,  or  even  when  the  posterior  roota  only  are 
ri<l<M).  The  nwaaure  of  iheir  de\'el«pin«nt  both  in  luiinmls  and  in  man  i» 
ki  closely  depeadeat  on  the  tondiiion  of  die  spinal  cord  and  of  the  central 
l^'out  system  KeDerally.   They  may  l>e  increased  or  dimiaisbed,  aH^nienled 

inhibited  by  a  roincideot  voltintary  efTurl  directed  toward  some  other  end. 

by  the  coincideol  development  of  a  ttnfficieiitly  distinct  sensation.  lu 
Deral  it  may  be  said  thai  whatever  favors  the  lu-tivitr  i<f  the  spinal  cord 
nrla  to  iuorea^e  ibem,  and  whatever deprnwm  the  activity  of  the  spinal  cord 
If  is  In  itiminiMb  tliem.    They  are  diniini«hc<l  or  waniinit  in  certain  diieases 

the  ipiniil  iv>ni<,i;.i;.,  locomotor  ataxia*)  and  exa|j:^i-niti:il  in  others:  so  much 
tude«xl  that  thrr  have  become  of  practical  clinimil  impurlAiKv  as  a  means  of 
iKnoaia.  WI>otiii-r  «c  regard  th<!m  il>  inilunciv  nf  onlinurv  reflex  action, 
«ioiuMer  tlinl  th<--v  are  carried  out  by  the  mii^ole  ibwlf  and  thai  the  cord 
brreim  otdy  »o  Cur  a;"  to  increnac,  raainUiin,  or  diminish  the  irritability  of 
I^JUiaciitar  fnbatancc.  il  rrmaimt  good  that  tbev  arc  prominvot  whenei'er 
■■BoditioDt  iucrewe  the  rodcx  or  other  oxcitability  of  the  cord,  and 
ffiilh  or  disapjiear  wbon  tlw  condilionH  lower  or  abolish  that  excita* 
Sit. 

t  600.  Disease  in  man  re\'eals  other  actions  of  the  Bpinal  cord  which  bear 
ituree  diflereut  frum  thwe  of  an  onlinary  reflex  uioveiDent,  and  yet  have 
fa  dcKribed  as  retlex  in  nature.  For  iDitauco.  certain  affections  of  the 
rd  ftK  diaracterixad  by  the  le^a  beeomtng  rigid  in  L-xtrenie  extension,  the 
;Mitr  of  the  Btrai)ihtened  limlia  being  often  so  j^reat  thiit  when  a  bystaDder 
ta  up  one  lej-  fmni  the  he«l  the  other  \tg  i>  raised  at  thi-  raoic  tiote.  Ttie 
>idiir  is  due  to  the  exten.tor  muscles  being  thrown  into  a  ittate  of  contract 
a.  which  in  to  uniform  and  long  euntiauul  that  it  may  be  »poken  of  as  • 
onic"  ruulmction  ;  iiuch  a  tontc  rigidity  may,  however,  tie  replaced  by  a 
Pie*  uf  rhythmic,  "clonic"  contravlions.  It  fuut  someiinHS  l>een  olHcr\'ed 
K  llie  limbawhen  flesiil  un,'«oj>pli-  nnd  frrefrom  rigidity,  hut  tltnt  rigidity 
ft  In  M  won  as  they  are  brought  into  the  pixtiliou  of  cKlcnKJon.  the  leg 
tomiDc  Midilenly  fixed  and  Mrnight  fomcwhat  in  the  way  that  a  rtiup-knile 
ring!  back  when  oftencd.  It  wcms  clear  that  the  peculiar  contraction  is 
rriM  nut  by  means  of  the  spinal  cord,  but  the  whole  action,  though  it  i* 
tfn  spoken  of  as  a  "  musclo-rcfles."  is  very  unlike  an  ordinary  n^dcx  more- 
int.  In  an  ordinary  morement  an  extensor  is  brought  into  action  when  a 
)b  is  Aexed — not  when  it  i*  already  extended;  and  if  in  a  reflex  act  the 
tditiuii  of  the  ninscic  about  to  be  thrown  into  actlOli  detemines  in  any  way 
I  dischar};c  of  impulses  from  the  reflex  centre,  we  should  expect  that  the 
etching  of  an  exieiuer  muscle  by  flexion — not  its  relaxation  by  extension — 
Uld  determine  the  dischsr^e  of  exleusur  impulses.  In  the  ease  of  ibe  dis- 
irs  in  •jueMion  just  the  oprHisiie  seems  to  take  place ;  iIm  poajtian  which 
pt-ar*  to  determine  the  development  of  the  remarxable  ctviilractinu  it  pre- 
e'y  that  in  nhich  Ibe  urain  upon  the  exteoMTs  it  at  it«  wioimum.     It  may 


730  THE    SPINAL   CURD. 

be  doubted,  therefore,  ivbether  the  word  rellex  Bhould  be  used  to  deimie  suib 
phenomeiia ;  but  the  phenomena  themselves  deserve  atteatiuu,  e^peciuliv, 
jierhaps,  as  showing  how  in  the  disorders  of  the  gray  matter  of  the  cdfiI  <Iup 
to  disease  impuisea  or  influences  which  are  latent  only  in  health  Ihihhk 
actual  and  effective. 

It  remains  for  us  to  speak  of  the  part  plared  by  the  spinal  coni.  a^  il>,' 
instrument  of  the  brain,  in  the  execution  of  vofuutary  movements  ami  IuiIk 
development  of  conscious  sensations;  but  it  will  be  beet  to  con$i<li?nhtM 
matters  in  connection  with  the  brain  itself,  to  the  stiitly  of  witieh  n  m^\ 
now  turn. 


CHAPTER   II. 

THE  BRAIN. 
Os  Some  General  Features  of  the  Structure  of  the  Bbaix. 

§  601.  It  would  be  out  of  place  to  attempt  to  give  here  a  complete  clescnp- 
tion  of  the  structure  of  the  brain ;  but  certain  features  must  be  kept  fresh 
in  the  mind  as  a  basis  for  physiological  discussion  ;  and  to  these  we  must  now 
turn  our  attention,  a  general  acquaintance  with  the  topographical  anatomy 
of  the  brain  being  presupposed.' 

Like  the  spinal  cord,  the  brain  consists  of  "  white  matter,"  in  which  the 
nervous  elements  are  almost  exclusively  niedullated  fibres,  and  of  "gray 
matter,"  in  which  nerve-cells  and  other  nervous  elements  are  also  present ; 
but  the  gray  matter  of  the  brain  is  much  more  variable  in  structure  than  that 
of  the  spinal  cord,  and  possesses  features  peculiar  to  itself;  these  we  shall 
itudy  later  on. 

For  physiological  purposes  the  brain  may  be  conveniently  divided  into 
parts  correspon(line;  to  the  divisions  which  appear  in  it  in  the  embryo.  At 
BD  earl^  stage  in  the  life  of  the  embryo,  that  part  of  the  medullary  tube 
which  IS  about  to  become  the  brain  differs  from  that  which  is  about  to 
become  the  spinal  cord,  iu  that  the  central  canal,  which  in  the  latter  is  of 
fkirly  uniform  bore  along  its  whole  length,  is  in  the  former  alternately 
widened  and  narrowed,  so  that  the  tube  forms  a  series  of  vesicles,  the  cerebral 
vesicles,  succeeding  each  other  lengthways.  At  first  these  vesicles  are  three 
in  number,  called  respectively  fore-brain,  midbrain,  and  hind-brain ;  but  the 
fore-brain,  after  having  developed  on  each  side  a  lateral  vesicle,  the  ojilic 
vesicle,  subsequently  transformed  into  the  retina  and  optic  nerve,  gives  rise 
ID  front  of  itself  to  a  pair  of  vesicles  placed  side  by  side,  or  rather  to  a  sinf^le 
vesicle  with  a  deep  median  furrow,  the  vesicle  of  the  cerebrum,  containing  a 
cavity  divided  by  a  median  partition  into  two  cavities,  lying  side  by  side, 
which  open  into  the  cavity  of  the  original  fore-brain  by  a  \ -shaped  opening. 
This  embryonic  chain  of  vesicles  is  developed  into  the  adult  brain  by  uneiiual 

KDWth  of  the  walls  and  unequal  expansion  of  the  cavities,  certain  features 
ing  also  impressed  upon  it  by  the  ))end  on  the  longitudinal  axis,  which 
tak^  place  in  the  region  of  the  mid-briiin  and  is  known  as  the  cranial 
flexure. 

S  602.  In  the  hind  part  of  the  hinder  vesicle  or  hind-brain,  the  ventral, 
basal  portion  or  floor  is  thickened  lo  form  the  liiilb,  while  the  greater  part  of 
the  dorsal  portion  or  roof  does  not  thicken  at  ail,  is  not  transformed  into 
nervous  element*,  but  remains  as  a  single  layer  of  epithelinui,  adherent  to 
the  pia  mater  overlying  il.  and  so  forms  a  thin  covering  to  the  lo/.enge- 
shaped  cavity  of  the  vesicle,  now  known  as  thoj'juiih  veiilrielr. 

In  the  front  part  of  the  same  hiiiit-brain,  on  (he  contrary,  the  roof  and 
Bides  are  enormously  developed  into  the  conspicuous  eertbel/tim  overhanging 
the  front  part  of  the  fourtli  ventricle,  while  the  lloor  h  aho  thickened  ntto 
tiie  ponti  Varolii. 

^  Flgn.  isr»  lo^l.  vhich  will  U'  Itiiinil  iii  '■in'c^'t'iliit^'  ^^i-Ildiis,  ikuiv  vi  illi  ii.lvjiiiTiigr  U<  i^on.'-ijiU'iE  m 


~i2  THE    BHAIX, 

This  ihifkeiiiiig  of  tlie  pons  is  Jurgely  made  up,  on  the  one  hand,  of  tori- 
ziiiunl  nerve  fibri's,  which  run  tninsvereely  from  each  side  of  the  cerelitlluni 
inm  the  |miii».  or  from  one  side  of  the  cerebellum  to  the  other,  and,  on  the 
other  hand,  of  longitudinnl  fibres,  which  run  forward  from  the  bulb  and  vt 
wmp|>ed  round  l)_v  and  interlaced  with  the  others.  At  the  front  margin  uf 
tlie  ]K)ns  these  longitudinal  fibres,  augmented  in  number,  appear  as  two  thi^ 
strands,  the  n-'ira  crehri,  forming  the  floor  of  the  mid-brain,  the  rouf  uf 
which  is  thickened  into  the  '■(•rporn  ijuailriijeiiiina,  and  the  activity  of  which 
is  reduced  to  a  narrow  tubular  passage,  the  a'jarduet  of  Sylvint,  oiiUrn 
ti-TlIt)  ml  ijiiiirlam  rentricnlinii. 

At  the  level  of  the  fore-brain  the  crura  cerebri,  diverging  rapidly  fhui 
each  otiier  as  (hey  pass  forward,  leave  the  median  portion  of  the  floor  of  ibt 
vesicle  now  known  as  the  third  efulriele  very  thin,  but  form,  eepeciallv  behind 
and  veutricalty,  thick  lateral  walls,  which  are  further  increased  in  thickoai 
by  the  development  on  each  side  of  a  mass  largely  compoeed  of  gray  maittr, 
known  as  the  uplie  t/talamus.  The  roof  of  the  third  ventricle,  like  that  of 
the  fourth  ventricle,  is  not  developed  into  nervous  elementa,  but  remust 
extremely  thin,  and  consists  of  nothing  more  than  a  single  layer  of  epi- 
thelium. 

S  603.  In  front  of  the  third  ventricle  each  diverging  cms  cerebri  spreii' 
out  in  a  sma^  j;^^ia1  tiishion  into  the  corresponding  half  of  the  paired  vesielt 
of  the  cerebMuQn  now  developed  into  the  preponderant  cerebral  hfmupkerti, 
the  two  cavities  of  which  are  now  known  as  the  lateral  venirida.    Tbt 
growth  of  the  cerebral  hemispheres  is  not  only  much  greater  than  that  of  tb 
rest  of  the  brain,  but  also  takes  place  in  a  special  manner.     At  their  fini 
iipi>earance  (he  cerebral  hemispheres  lie  wholly  in  front  of  the  fare-braiB  m 
vesicle  of  the  third  ventricle,  but  in  their  subsequent  growth,  while  expuid- 
in<r  in  nearly  all  directions,  they  extcod  especially  backward.     Thus,  in  the 
adult  brain,  on  the  dorsal  surface  they  not  only  completely  cover  up  tbe 
third  ventricle  but  also  overlap  the  raid-brain,  reaching  so  far  back  u  to 
cover  the  front  border  of  the  cerebellum,  while  on  the  ventricle  surfice. 
though  in  the  middle  line  thev  leave  exposed  the  floor  or  ventral  portiouof 
the  walls  of  the  third  ventricle,  at  the  sides  they  are  seen  to  reach  as  far  back- 
wiird  as  on  the  dorsal  surface.     The  median  furrow  on  the  dorsal  surfiw* 
which   separates  oacii   hemisphere  from   its  fellow  is  at  first  shallow,  but 
ra]ii(!ly  deepens,  so  that  lis  the  hemispheres  grow  they  become  separated  from 
each  other  hy  a  narrow,  deep  longitudinal  fissure,  into  which,  as  we  shill 
see,  a  fold  of  the  dura  mater  dip?.     This  fissure  is  not  only  deep  vertically— 
i.  '■..  from  the  dorsal  surface  ventrally — but  at  the  front  of  the  brain  nwa 
backward  in  the  middle  line  almost  as  far  as  the  level  of  the  third  ventricle, 
so  as  com[)]etcly  to  separate  from  each  other  the  anterior  parts  of  eifl< 
hi'niis|)here.  known  as  the  anterior  lobes ;  at  the  back  of  the  brain  also  it  siou- 
larlv  runs  forwanl  in  the  mi<ldle  line  for  a  considerable  distance,  so  m  l*) 
separate  frouj  each  other  the  posterior  lobes.     Hence  the  two  great  maajesof 
the  cerebral   hcmisjthere  are  united  with  each  other,  not  along  their  whole 
length,  but  lor  about  a  third  of  that  length,  the  isthmus  or  bridge  thus  cod- 
necting  them  lying  at  some  depth  below  the  dorsal  surface  at  the  bottom  of 
the  longitudinal  lissure,  in  about  the  middle  third  of  its  length. 

At  its  first  appearance  each  lateral  ventricle  is  of  a  more  or  less  oval  form, 
its  walls  are  of  uniform  thickness,  and  it  lies  in  front  of  the  third  ventricle. 
During  llie  growth  of  the  hemispheres  it  acquires  a  peculiar  shape  tad 
iK-comcs  dividwl  into  an  anterior  cornu  or  horn  stretching  into  the  Mterior 
jinrtion,  a  ]>(>3terior  horn  stretching  into  the  posterior  portion,  and  a  dwceod- 
iiig  horn,  which  curves  laterally  and  ventrally  into  the  middle  portion  of  ihe 
ln-niisphere ;  owing  to  the  great  backward  extension  of  the  hemijpbere!  tie 


TTrRE   OP   THE    BRJ 


I 


lat«rat  vAR8B  eofuc  !<>  lie  iioi  uuly  in  frunt  of  hiit  n\»n  ut  the  ■!•!«■  of,  luii) 
iiid«nl,  li>  a  ccfUin  esttuit,  «bov«  or  rlursnl  !»  llio  tliinl  vtuilrii^lc :  hikI  <Iuriiig 
ihk  gronth  of  ih«  iNirls  tlm  urifriiially  wide  V'»)m])*H)  •i|H.-ijiiig  nhirh  iiliu'rH 
tbtkiod  eixls  of  ttic  two  lateral  vetilrirltv  in  oiiTiimuiiknltun  nitli  (liv  fnmt 
ut  Ih*  third  Tenlncl«  beeune*  DarTuvtul  into  a  uliiliki-  fnuMfjr  of  niiiiUr 
fen.  th«  foramen  of  Monro,  wfiieb  still  <)|H-inu);  inli>  tlxr  lV»nl  ut  llii-  thini 
rnitriclr,  tiovt  lru<l'>  on  i^ai'li  »Ulf  from  ■  point  rather  in  front  of  tbo  middle 
of  thr  lairral  vi-iitricU'. 

A«  the  bomwiihi-n-  enliirgw,  llie  growth  of  the  wall*  of  tin-  vi^iclv  i»  luit 

uniform  in  nil  piirL'^    At  niioirly  ppriod  tli«rc  may  be  nb#erve<l  in  ihv  vcninil 

ytmll  or  floor  of  tlii;  viviclr  it  ihickiiiing,  whirh  iLnumiiig  a  npi-cinl.  niorc  or 

Ina  MfniluDBr,  form  and  pr<>ji:t;ling  into  tlic  cnvity  ttecomv*  the  binly  known 

a*  tb«  oorptu  tiriatiim.     As  HfvrlopmenC  procc%(t*  the  corpus  striiitum  on 

«aFb  ridv  bccomtK  attachtvl  to  Ihr  npiic  thnlnmi:*,  lying  l>chinil  rimI  to  the 

■nrdian  fide  of  itwlf,  tlm  railiiUing  librm  of  ihr  cni«  cerebri  piming  belireeii 

tbfitwo.  nodalwni' wcthall  mv  diviijing  the  corpux  ttriatuni  inio  two  hodin, 

called  the  neufUu-'  rauHatiin  anil  utn^r'U  lentinilarit.    A  notnble  rmult  of  ihu 

rmwth  and  change  of  position  of  ihc  hemispheres  iind  of  the  ciideseence  of 

Uie  corpus  ttriainm  mtb  the  optic  thnlnmtis  is  (hat  the  lutler  btxly,  ihouek 

really  lielonging  to  the  third  ventricle,  come*  to  projcci  somewhat  into  tT>e 

lateral  ventricle ;  a  strip  of  the  HOjier  surface  of  the  opiic  thalamus,  alon^ 

its  outer,  lateral  edge,  forniB  n  portion  of  the  tloor  of  the  lateral  renirii'le  in 

the  ntedian  re|;iou  on  each  si^le  of  the  third  \'entricle.     Besides  ■hi-'  Hiiecial 

ileTelopiDeDt  of  the  corpus  striatum,  the  walls  of  each  vesicle,  witii  the 

txee[ition  of  the  median  part  by  which  the  two  veeidee  coalesce  with  each 

Otber,  become  (we  are  now  speaking  of  the  higher  luammala)  tbiclccned  much 

io  tbe  isine  way  all  over,  the  surface  being  folded  so  as  to  give  rbc  to  ran* 

volutions  or  .vyri  He|ianiled  by  furrows  or  *u/c*;  and  the  thickening  taking 

place  in  such  u  nav  as  to  give  the  ventricle  its  peculiar  sba|)e.    Tbe  mtdiau 

coalewod  pan  underKoes  a  ditferent  and  peculiar  chan);e.     t'hi."  |>urt,  which 

att  fint  lio«  ill  fnmt  of  tliu  third  ventricle,  through  the  cbaiigm  bn>ught 

■bout  by  tlio  growth  of  tlic  hembpberei  to  Mttti  its  laitiitiim  us  to  liv  ininio- 

Idialely  over,  dorsal  m  tlic  third  ventricle,  very  much  ax  if  this  part  of  tbe 
c«n>bnU  vsidts  hnd  lieen  folded  badt  over  tlw  fore-brain.  Id  the  junction 
ttaalf  we  nav  dlMingtiiidi  a  dnnml  and  a  ventral  ]M>rtiiin.  Tbe  dorenl  portion 
it  developed  into  a  srslera  iif  traiuvcne  oonimiMinrul  fibru*  paanng  acrom 
ftooi  one  ncDii'phvrc  m  the  other.  In  the  median  ref;ion  them  fibres  form  a 
tlliek  oompact  hnml,  i-alh-d  the  nirjm*  talbmtm,  whuh  may  be  eiposed  to 
view  at  the  bottom  of  the  longitudinal  firwure.  while  on  each  side  they  spread 
away  in  all  directions  to  nearly  all  |uirlji  of  tlw  surface  of  the  hcniispber«e. 
pHiiog  orer  and  helping  to  form  the  roof  of  the  lateral  ventricles.  The 
Mod  M  not  Hat  but  cnrvctl  vcnlrnlward ;  hence  in  a  longitudinal  vertical 
»ect)on  of  the  brain  taken  in  the  middle  lino  it  prcMOlta  ft  curved  form  with 
the  concavity  directed  vcntntlward.  While  tbb  donal  porti'^i  of  the 
junctfoD  is  developed  at  the  sides  as  welt  as  in  the  middle  hoc,  the  ventral 
portion  is  devdoped  in  the  median  region  onlv,  and  that  in  a  special  way,  co 
lliat  it  fonns  below,  ventral  to,  the  corpus  callosum  an  arcbeu  gilule,  in  the 
ahajie  of  a  triangle  with  the  a^x  directed  forward,  called  the  jomU,  which 
lie*  tnunediately  above  the  thin  epithelial  roof  of  tbe  ihinl  ventricle.     In 

tfhinl,  the  narrower  apical  |)ort)oa  of  the  fornix  lies  at  some  little  dittiince 
below,  ventral  tu,  the  ei>rpus  calloaum,  and  here  the  Juuction  b<4neeu  the 
two  vcMolea  is  rvduoed  to  a  ibin  sheet,  tbe  tcfilum  laetJam  ;  but  behind,  the 
bmuler  baMi  portion  of  tbe  fornix  b  arche<l  upsoas  to  lie  tmmi-diately  under 
and  loueb  the  cirpo*  eullwitim.  Henee  the  septum  luddurn  haa  the  furm  »f 
a  mere  w  lc*>  triangular  vertical  sheet,  broad  in  front  ilQil  narrowing  behind. 


I 


7-il' 

r'i>                                                         .  -■   iiiiiv  l)f  '■iiin'tivt-d  ■'!  ;i- 

iiK'i  ■!  ■     .     ■  .«!  Li  iiarrnw  cl'i^il  cavuv 

■  ■iL- r  ■  .^  i;-.;le  lli<'  hiUTiil  v.'nirW-. 

"rii:i;'    ■  ■■-iricle,  iiiiil   th'-  lliinl  vrti- 

ill-  [■■.  ivitli  iht-  fiiurtb  vi-riiri-.k 

.-ii';ii,  ;■  .-  -:>ina}  cin"il.  lln"  wlii'ic- *rir- 

utji.t!  ■-  -L.-:"ii  caniil,  tlir  lit'th  vfiiiriilr 

N  i>i'  .          i' ditieiviii  iirigin. 

''!'■"■■     ■  :ueli!>n  iH-twoeii  ihi-  vi^ioiw 

A:    ■'.  _   ..-  viiole  IviiiTtli,  nil'!  thu;  I'TM? 

i-.w\\    ■■  -.  -.  Lt'ilier ;  llio    uiiilille  )inrii"i. 

vi-i',!-  I-  -■■;n.  tlmiigli   i-iirviiiir   over  iht 
ami  I-.:.-... ..                                                   .        ■i.-i'ili!  pari*  <)f,llR'  Iiomia[>htre. 

Iiy  ill-  li.  ■.■  .  J, '11  ^i>U' Ibrwnnl  ami  backward 
kiMui;  ,.-                                                     -       ".;- '.Iimtijili  llie  c'<ir|ius  (■sIIp'ub: 

i!ii-  i;'!;ii.     .  „  :;i;.'U'^  wiili  that  <if  the  yiW. 

csli--- ...        ■■;.  i:  i>I'  the  JHIIctiiill  i;-  verrilil- 

tliiliiiii.  -aLfsintotvco  baitiU,  kinjwn  asiW 

!  60:J  .■  ur  oi'iuiuuiuis  ivilh,  iiml  irtkea 

iiUL  ill  :i  ■  ..-■■\^.     Ill  like  nianiner  heliimi. 

!■('  III.'   ■  .:::iun>iis  vcilli  the  wall?  "f  ibc 

till'  :v.-  .  <  mass  of  llie  lieiiiL^phtrc^.  Ifiiii' 
j;ivm[i;     -                                                         ■  .--.I    allwl  the  crura  i)f  [III' i'lrnii- 

ri-ii  .■;■  -,-:  -he  attai'hiiit'iit."  in  t'ninl  viA 

ii|ijii'in:i::  -jrimieii  iiiln  llio  .■iiil)>taiice  "I'llie 

vi>i,  Ip-  ,.  :'  niix  iippearii  'Hi  earli  si>if  ''' 

iii^'  in  If.'  '  :  -aalaniii:^,  wjiicli  htro  f^iriu' lb.? 
;iiliilt  ':■  .  -iitrii-U';  bi'twirii  llio  ii]inf  [bl- 
lliini  ■,. ;  ■                                                       -  ,-[us  In  be  a  iiainiiv  <iii  bv  wliifb 

i-iiv'f  ;'■  aiis  with  jiiirlri  niitsiilc  it^elt'    In 

tb.'iijii  ii-  ■  -:  ;■  c.mtimiity  llumjtb  iberv  i*  a 
till'  \.:i!'-                                                           ,  -i-'-iiieii  uvoi'  bv  u  biyer  .if  i.|"illn" 

■LIS  is  iniiile  i-i)iiti(iiioti>  ttitii  iht 


«;ii'.i  :i^ 


»liii'ji    -  ;        ■  ■..;  luMian  wall  of  llif  latiTiil  vi-ii- 

rii].i.|lv    !•  ■  .;::tUiiiii  has  tlielbllDHiri^-  |iefiiliar 

LM'-li   •■■].■:     I  ■  .--„:: 

,-.■!■.  ;;  !'..i..  ■  !  -  -,  .-.uiriele.  like  that  of  the  f.-iirili 

i'.  I..  :':..:i.  :■  '   ■■  .■  I'lai  ileviiid  of  liiTVoiis  eleiiii'iilf- 

li;ui%u;ii-.:  _..  -ae  hiiiil  part  nf  the  i.-orpu*  w!- 

<■.  a-  .    ■  ,;.■.'   ■  ..    ...r.  tiiiivl  veiitrii'le,  tbe  free  ii.i»i'l 

lii'iiii-|.ii.'.   '  ■■  .        -e  iMrpiir' callosuiii  ab.ive  ti.irmiui: 

huh  ...p.-  I  ■.■■  ..    T  bri'ljie  betwetii  tbe  iwn  henii- 

i-e|iiir;ii.   ii  ■■.   -  -    ; , rsal  surface  of  the  liraiii.  |ia.-iii? 

the  I-.  r.i.i:i,    ■■    ■    ,  "      -,„.*  .vor  t!ie  ^)|^ofthL' third  vonirii-'k 

leiiilih,  i-'i  !■■■    ■  __-,-.jiijiiiti  referred  to,  ami  ihiis  I'.inn: 

iif'-iit.j  iln'iii   ■■.  -:    ■                               ,,-,     11.  which  p^rvw  !w  tlie  aomal  r"' 

llio  |.>ii.;(iii.ini..:  ■  -                                      .,  .,.  ventral  to,  the  l>)riii>; :  ii  eauD"i 

\i  ii.-ili-;  ;i|.i.  •                                _     :- ■drills.     At  the  lateral  iili.'0"ftlif 

i!:-  H!ill-  :l!-.-  ..I   ■■•■  il...i:  *b«t  of  pia  mater  ]iri'Jei'l.<  ff'™ 

iiiiriii;^    Hi..   ji.  ..     -j.r-ole  carryinft  with  ii  the  UviTfll 

l«|..,'ij.--  .iisi<i. -:  "'_.     ^t  rtlgo  of  t  lie  luriiis  actually ''"'i' 

|i  .iri.ti.  ::  |"i>i.-p!  '  '    ■                        J"  -    ■■^-  "-aicral  veiilriele;  the  jtari  ol  ibr 

i:i-  i:-.irK  "iiii'i ■                '_„  1*  tulire  of  thi!  fornix  when  the  Is'ewl 

!:■  vi^-|ili.-r.' :  M«':-'     •  -     "    ,    ,....,■    I'l.nw.     Tj  thi<  i>eciiliar  iutniJU'i 


THE    BKAIN. 


7S5 


i  ili^  ptR  nuiier,  by  whicli  tbe  nutrition  of  tbe  bmiu  ix  awislod.  w^  nhall 

Niuni  wbeii  w«  com«  (u  'jieiik  of  the  vanculnr  arinn^mflnto  of  tbo  brain. 

JlcttawllUf  Vf  miiT  piiiul  out,  thnt  vrhilc  Ibin  viwrulnr  itignivrlb  wviat  to 

«uk»  Ui«  cavity  of  iIm>  tbinl  vencncli;  ontiiiiiouii  with  that  of  the  Iiit«ral 

f«nlfid«  on  Mcb  aUo,  ud  mil  thrw  wicli  tlir  ■■xtnrior  of  Iha  brain,  it  rcally 

doOT  Dol.  do  Mil     The  mvttr  of  iIm-  lliinl  vcncridv  k  voiAq  complete  by  th'« 

jAjrar  of  vpithdium  formiiii;  if  nuif,  biuI  tht;  citvity  nf  the  luteral  rentriele 

£•  nuMl«  oanip1«t«  by  th«  lityer  of  cpithi.'liuni  pawing  fnm  the  lateral  edge  of 

the  fomit  orar  tba  choroid  plezui  to  ttiv  oilivr  pnrts  of  tbe  wall  of  tbe 

^rttUtriele.    To  pum  alonz  thii  line  from  tbe  nctiinl  cavity  of  the  Inteml  intv 

that  of  tin-  third  wiitride  one  mtiat  firot  pierce  the  opitheliuia  ooverinj;  tbe 

«3horoid  plexus,  thus  Kainiog  acce«  to  tbe  pia  mater  of  the  plexua  and  of  the 

^r«li)in,  and  then  again  pierce  tbe  miithelium  coating  tbe  uuder  aurface  of 

she   veliitu  and  forming  tbe  roof  of  the  tbird  ventncl«.     I(  bonly  by  ibe 

i'-iranien  of  Motiru  thnt  n  r«nl  com  muni  cat  ion  ex'ttxe  between  the  eaviiy  of 

the  lateral  and  that  of  the  tbird  veiilrii'le. 

Thu»  bv  the  Iar|>(>  j^rowib  and  backward  extension  of  the  cerebral  haini- 
epberea,  tfte  third  Teatride  cornea  to  form  as  it  were  the  front  end  of  the 
orBbi«>«pinal  axis,  the  erara  oei«bri  expanding  on  each  aide  of  the  third 
vasirirle  into  ibe  cerebral  hemiepherea  wbieh  cover  up  the  ventricle  on  the 
4araal  !>urface.  but  leave  it«  walT exposed  ou  the  ventral  surfoce.  Allached 
to  the  donal  aur&oe  of  the  third  ventricle  at  \ui  bind  end,  ventral  to  and 
tonevhai  prtijecitiii^  beyond  the  Imae  of  tbe  fornix,  lie*  tlie  pineal  gland  with 
itaattacho>enl*.iheremnantjiornun<.-»important  nu-diao  oi^an;KndatIaobed 
In  tbe  \-vntml  mrfiuv  of  tbe  ventricle,  at  the  a[n-x  nf  a  funnel-abaped  pro- 
jvction.  the  infuitdibuluni,  lies  tbe  pituiliiry  body,  alao  a  remnant  of  important 
■acatral  i>tructurw^ 

S  604.  We  may  then  divi<)e  the  whole  brain  iiiUi  a  tfcric*  of  ports  corr«- 

xndiog  to  tbe  main  division*  of  the  enibryonir  brain.     At  tbe  front  lie 

oeretira]  hemispheres,  with  ihc  lateral  venlriclcs.  develupod  out  of  the 

'bral  veaieles :  and  with  thoss  are  asaaciatod  tbe  corpora  striata,  the  term 

rebral  hemisphere  bi^ng  somelimea  wed  so  as  to  include  thene  bmlie*.  and 

tM>iueliii>e6  so  as  to  exclude  tbcin.     Next  cume.  correspond iiig  to  the  original 

't'orir'-liriiiti,  iIk  parl»  forniini;  the  walU  of  the  third  ventricle,  Ciinjpiouoitt 

atmODi;  which  are  the  optic  thaiami ;  tor  thoie  bodies,  though  they  appear  to 

intrude  into  the  lait'ral  ventricles,  belong  properly  to  tbe  third  ventriole. 

la  Um  mid-brain  which  follows,  the  cavity,  now  the  tubular  iMssan  of  tbs 

aquedoct.  b  roofed  in  by  tbe  two  ]mir«,  anterior  and  poatenor,  of  oorponi 

•luadrigemina,  the  diineusioos  of  which  are  not  very  gnat;  b«t  a  thick 

tiour  >•  furnished  by  the  crura  cerebri.     In  each  crua  we  muM  diatingniah 

httiraoo  a  dorsal  portion  called  the  Ugmenium,  in  which  a  Urg«  (quantity  of 

gnty  matter  la  present,  and  in  which  a  great  complexity  in  tbe  arrangement 

of  fibres  cxtsls,  and  a  ventral  puriion,  the  ftet  or  emtl't,  which  is  a  much 

inon  nnifiirm  nius  of  lougiimlinally  di.ipoW  fibres.     Ai  the  cnira  pawing 

Ibrward  divenn  into  tbe  cerebral  humiupbere  on  ea«h  aids,  the  t«gine«itam 

OMuea  at  the  hinder  end  and  ventral  |Mu-ta  of  the  optic  ibaJaidu*:  it  is  tbe 

pea  which  fuppliea  ibe  ma»  of  fibres  radiaiiii;^  into  each  cerebral  hemisphere. 

In  a  view  of  tbe  ventral  surfincc  of  th*  brain,  tlw  base  of  the  brain  as  it  is 

fteqnantly  called,  the  enirn  may  bo  seen  omergiog  from  the  anterior  border 

<if  the  pon».    Thii)  we  have  ajMkcu  of  n«  tbe  thickened  floor  of  th;  front 

part  of  the  hind-bniin,  hnt  in  reality  it  eueroacbes  a  lilUe  on,tbe  mid-brain, 

the  hind  pnrt  of  the  oirihini  ijuadrigemiua  haing  in  the  earn*  dorso-vootrat 

plane  a-  tlie  front  p.trt  of  the  poo*.    (8>e  Fi^.  180.)     In  the  main,  bowerer, 

the  poiia  baliHies  to  the  fore  pnrt  of  the  hind-brain,  the  roof  and  aides  of 

wblvn  are  deralopod,  at  wo  have  raid,  into  tbo  cerebellum.    This  snperfieially 


I 


786 


Tiie  BRjLiy. 


meitiMcs  tho  cvrebml  hciuMphvros  in  iu  Inrg*^  eizo,  atx)  in  (he  rpnijil 
>li>v(!li>[inicnt  of  its  eurrncv,  whioli  is  formod  ol'  grny  matter  fnldcti  in  ■ 
n-mnrlcitblo  mtinncr  mikI  oflrn  ^txikcn  of  us  cnrux.  The  wfebvllaia.  th-iueli 
tho  Ititcnil  |)Drlioos  ohIIc^I  iIk  nemi»phorM,  pr>:>jvct  above  the  tnedUn  fiJt- 
ttoii,  called  the  vcrmit,  i«,  unlike  iho  cerebriim.  n  single  mus:  euili  latml 
hair.  Iiowercr.  ^ends  down  v<>ntrnlly  a  maBi  of  libm  whicli,  ruiiDiDg  tn» 
Tcreelv,  purely  etid  in  the  poDs  mid  portly  Are  continued  acn«a  ibe  pMa  iatn 
the  otiier  lateral  half;  this  nitiss  of  fibres,  thus  oonstilUlinjf,  as  wc  hav«  nid. 
■  considerable  part  af  the  pons,  fDrmit  un  each  side,  juH  as  it  Itara  tb' 
cerebellum  to  enter  the  ptiDs,  a  thick  i>[rand,  called  the  miihiU  ftr^nuAt  -i 
ibe  cerebellum.  From  the  cerebellum  there  alfio  pruc^edi^  buckwafl  ^ii' 
the  hulb  on  each  side  a  thick  strand  of  6brea,  the  inj'rritir  frdup'i' 
cerebellum  or  resiilbrm  body ;  and  a  third  strand,  ihe  taprrior  jifi 
the  t'erebellum.  pa^ce  furwan)  un  each  side  into  the  regioo  of  thv  onqm 
iiuadrig«niina.  As  the  latter  converge  toward  each  other  behind  ihv  mr- 
|)Oni  (]ua()ri^u)iuft  the  ajijtie  becwtwu  tliem  is  iill«i)  uii  hy  n  ihiii  dW  >i 
nervous  matter,  Ihe  vnU-t  of  Viciuuenii.  which  thu*  for  a  little  di*l«iin-  ba». 
ward  furms  a  ruof  fur  the  fruiit  rmrc  of  the  fourth  rem  ride,  just  whrit'.U 
luxengc-sha^ied  CKvity  is  narrowing  to  Ixicome  the  a<)urcluct.  itchiiid  iw 
cerebellum  und  puns  cunim  the  bulb,  which,  a*  we  have  Mtitl.  u  tlie  lk>k 
eneit  fluur  of  the  hiud  [lan  of  the  hind-brain,  tiw  mof  uf  the  caviiy  benf 
ben jnolically  waiitinfc. 

Uftbcac  KOveral  iliviaions  the  fir«t  division,  that  of  (be  ccfebral  bmt 
sphum,  iuchidin^  ihi;  corjioni  Kiriiilu,  Hliind*  npnrt  from  the  rvst  by  rtsM 
Mlh  of  itH  (iriKin  "ud  the  chiLrnchrr  of  its  dcvelopntciil.  As  ire  sliall  it. 
this  nnaloniicjiTdidiiiction  corresponds  to  a  physiolodcal  diflerence. 

Of  tbt  other  parU  of  ihe  brain  the  crura  cerebri  dcterve  »|>ci.-iii]  m' 
We  may  repnrtl  these  as  starting  in  the  conl.  but  largely  a»i((in>:wii 
bulh;  ihey  traverse  the  pons,  where  ihey  are  Hill  lurther  imrin 
paiuiuK  beneath  the  corjmra  •|uudrigeiiiiua,  with  which  no  well  a^  " 
cenelK-llum  Lliey  make  connections,  end  partly  in  the  region  wJ'  the  t.jtr 
tlialaoii  and  walla  of  (lie  third  ventricle,  hut  to  a  great  extrul  iu  the  rffr^l 
hemispheres.     We  may  ui  a  certain  senae  ojuniiler  the  n»t  of  tlie  hnin  f 
buill  upon  and  attached  to  tbu^  fundutiietital  iiasal  or  ventral  Mrand'. 

^  60S.  CWuecied  with  the  brain  art  a  scrien  of  (laired  iMrv<«,  ihecniiw 
nervui.  The  Ar^t  an<l  neeund  pair,  the  olfactory  nerves  mikI  the  optic  ntnv. 
diffi-r  in  tlieir  origin  and  mode  of  devehi|mient  from  all  th<-  resttofuad*- 
mentidly  as  to  cause  regret  that  they  ant  inchi'lcd  in  ilu>  mmv  cate^rv.  Wr 
duill  n>ii>i<)er  these  by  thcinseive*  iu  ilue  cour!>i\  The  reiiminiug  pair-.  fr\« 
tJie  third  nair  to  die  twellUi,  fi>ritiing  a  iuu<'h  more  homoj^'tieou!'  nli^ri, 
nc  shall  al»o  consider  in  their  proper  place.  We  miirt  now  tiini  t"  muI* 
in  erMter  detail  fame  of  the  «tnictiiral  fcattin«  of  the  brain,  and  ««  an 
v'lw  iidvautagc  begin  wilh  the  bulb. 


Tnit  Bui-B. 

$  606.  The  spinal  conJ.  as  it  nsccnds  to  t)w>  brain,  beicuroes  chut>,   i 
the  more  complex   Imlb.  partly  by  a  shilling  of  the  course  of  ihr  :i 
white  fibres,  partly  by  an  opening  op  of  the  narrow  central  canal  i::: 
wide  and  superficial  fourth  ventricle,  but  chiefly  by  the  dcvelupmeiit  fi  i'' 
gray  ntatter. 

When  the  anterior  ventral  aspect  of  llie  bulh  is  examined  (Pig.  IH.CV 
It  will  be  seen  thai  the  anterior  columns  of  the  eord  are  iutrrrupied  i)t  •"*" 
iliiUnce  in  the  meiltan  line  hy  bundles  of  fibres  (/^f.  iltc.)  which,  ajipmri^F 


TRB   BRAiy, 


to  riM  up  IVom  dMpv  imrts.  erne  over  Froia  m\e  tn  u<le  aui)  ^t  cnnltaK 
line  of  liK  anUrior  flaturv.  lliU  is  the  iteeuMaliou  of  l/i«  /jyi-xiniiit.  ib 
wbiH)  lh«  |tl«ee of  the  anurior  colutuns  of  tlte  Bpiual  iiinl  li  utkou  bv  lai 
Uri^r,  man  pn>iniiM.'iil  <«)lumi»,  ihe  jiyramids  of  the  biilb  (I'l/.t.  vrliirl  iv 
coiitiniuil  fornnnl  to  iIm!  Iiind  niniytn  »f  the  imuh.  Oil  ih*-  uuior  -' 
lateral  to,  each  pyniinid  Ihsm  |ir<ii<H.'(in][  oral  iurib,  (A'*  olimrji  Ito'lii 
ymiN' i/tn*  {«/.)  MiNintiiis:  lli«  ]ivniiuM  ln>iu  a  <H>liiiiiti  of  wlitt<-  iiiaii<! 
rvH'/m'm  boily  (R),  whicK.  ocoupviiix  Ihe  luttiml  region  of  tti«  l>ull>.  -i.-j 
traced  back wahl  apiHtini  to  itmliuiic  tli«  liiK' of  ttic  Inlorml  oulumn  oftlM 
cnrd.  and  wli<rn  tmiixl  furwurd  in  m«u  to  ruu  U|>  to  tlK>  cerabollum  attbf 
interior  piilutiGlo  of  lliat  or^ii.  On  the  imtitrrior  dorxil  iwpecC  no  wtfli 
dwiiMalion  ia  men.  The  two  ixaurior  coliinntii  of  iliv  ii>rd  divers*  ^""^ 
eaob  otl>er,  leaviue  Imiwv«d  iIicri  h  (riausular  «|>«in-,  ihc  mhmu^  ter^dom*, 
wliicli  i«  the  hiiM  pitrl  of  ih<-  limongo-Hbaped  slinllow  cuvity  nf  the  l^itli 
veiitrk-le.  An  the  I'urd  luiwov  into  th«  bulb,  ilia  poKtrrior  (.-»liin)H  na  ■  wlwk 
l^rowb  bnuider,  nod  tlw  diriaioD  uito  a  inc<li4iii  jxwlorior  and  an  extenal 
jKieterior  t-olumti  becomes  veiy  obviou»  am)  distinct  by  the  nppearEiine  of ) 
ciuupictious  furrow  iM>|iiii-nling  the  two.  At  suoie  dnCaiice,  Itnwvrer,  ia  fnoi 
of  the  point  of  divergence  of  the  coliiiniM  or  apex  of  the  calaiuua  Krigrto- 
riiu,  (lie  fijrrow  bccumee  leae  marked,  und  it  eveutimllr  liidee  away.  In  if 
ii>urf«  the  furrow  I«kee  Mich  n  line  that  the  mediau  [nieterior  ntltimti,  forw 
ing  the  immediate  lateral  boundary  of  the  fourth  ventricle,  tuid  the  a]>pnr- 
aiiceof  aotraod  broad  behind  but  thiuuint;  atray  iti  front,  while  the  exterul 
fMiUenor  oolumii.  aluo  broadeniii);  as  ii  advaDcm  forwatd,  eeeitui  Ui  ite  wedpJ 
It)  betu'eeu  Ihe  median  piMerior  column  on  its  Dtedian  ed|;e  aud  tV-  —•'■'—^ 
budv  mi  ita  lateral  edge;  beiice  iIm  former  is  here  called  the  /  >? 

jHHiruiiui)  ^meili*  (iw.  p. ),  aiwJ  the  latter  the  faacieatH»{<it /unimif    •n"-;^*' 
(e.  u.).     Furilier  furuard  bolh  oolumna  aeem  Ui  merge  wiili  mch  otlm  whI 
who  Sbrea  which  curre  rouod  to  fono  part  of  the  mlifunn  body  ;  tli'  <<'i 
lions,  buvterer,  of  theae  two  columna  In  eadi  other  and  to  ihe  other  i>h  - 
the  bulb,  na  well  ua  ilie  nature  of  the  other  aeveral  changiii  hy  wtii     ' 
oord  in  trattaforoieil  into  the  bulb,  are  diacloaed  bj  trauavene  vtmii-al     ! 
Tcolml)  sedioiia.  to  the  »tudy  of  which  we  ninxt  now  turn. 

A  wction  <l'ig,  1>*7.  I)  tiikiTU  at  the  hind  ninrzin  of  the  decuwilin).  nl 
which  Icvtl  the  lirrt  i-erviail  n«vi«  take*  origin,  when  eomrarr<l  wiili  a  "■ 
tioD  of  ihe  cord  ai  the  \vv*-]  of  the  aecond  cwvioni  iier^'e  (Cf  Ktjj.  l^J  ' 
shon-ft  that  certain  i-hnng*-'  arv  almdy  tiikinj;  platw  in  Ihe  gray  matti-r.  !>'< 
anterior  horns  arc  not  much  altered,  htil  the  poatarior  lionu  are,  as  it  *'-^ 
pushed  out  laterally  and  dunsallv  m  thai  the  ])oaterior  columns,  wbirh  a*  ><■ 
nMain  their  previoua  great  <hi>t&,  become  rery  much  hninilcr  liiaii  Uic*  *rr 
lower  down,  eiusnuohmg.  to  to  M)Mnk,  on  the  lateral  oalnniOR.  At  ilie  auM 
lime  the  autMlaneo  of  ItoUndn  (<■■;;.)■  forming  ihe  hei^^or  eH{>ut  of  ihr  b"m, 
hut  enlarged  into  a  more  or  ten  globular  form,  and  lice  near  the  Mirf*  t  ' 
the  curd  thotigh  aeparalcd  from  it  by  a  eomiiaci  tract  of  Ioii);iiudtnnl  it-'" 
(  r.  a.),  which,  aa  we  aliall  sec,  beloofp  t<i  tlie  tidh  cranial  nerve.  A  '^f- 
oiderable  developmeut  of  the  reticular  formation  (/  nrf.)  at  the  »i<le  of ''" 
]{rar  matter  ventral  to  the  poMerior  horn  ha»  also  taken  iilai-e,  ami  ilw  ''^ 
the  ahiAiug  of  the  poailton  of  the  jMMlerior  1i<hii  hiu  <lriveti  the  Uietsl  h'm 
(t.  h.)  DtMTer  to  the  anterior  horo.  l-"riim  ihid  laletal  horn  a  nwi  uf  thf 
eleventh  apioal  aooeGBory  cranial  nerve  {XI. i  may  be  seen  taking  oH^i>< 
Further,  a  gfoai  increase  of  ijfny  matter  rnund  the  i-enlrwl  c-aitnl  lun.r  >!*-' 
be  obMrveJ! 

Thtae  ohanges,  however,  are  of  decree  only ;  vrbat  seeioi  to'  be  aa  ab**' 
luU-lv  new  feature  ia  the  preaeuce  of  bundtea  of  6bres  (/y  •if<.\,  whiebH"** 
iiig  from  the  anterior  t^dumti  of  one  aide  oroai  over  to  aud  are  appaTAj^ 


I 


'sr'lliiJUKkoflhciuilcriar  horn  of  Ui«  other  side;  ill 

enauug  ibv  Itlim)  |>iii>h  Mldt  tlit  bottom  of  tlie  anterior  finun.  Wlieu 
th«  counw  of  tliiwv  libn.^  i<  iDVf«tignted.  either  bv  8im|>lp  iDit^riMcopic  obKr- 
vktioa,  or  Mill  better  by  the  indnod  of  de^nprncioa.  it  is  fuiind  that  Uiev 
luav  be  Into-')  fnxn  thr  iitiKtrjor  coliimn  of  ooe  »iile,  acruw  the  itnterio'r 
oiiDDui^ire,  tlmMigh  (hr  ni.'vk  of  the  anterior  born  to  the  lateral  ooluutu  of 
tbe  oppOMt*  tide,  and  to  that  pnrt  of  the  Inleral  culiinio  whivh  we  have  pro- 
vtouslr  dcwribed  w  tlio  crossed  pTnimidiil  tract. 

lo  a  NctKiii  a  little  higher  up  <  Fig.  lr^7.  2),  these  decussating  llhred  form 
an  each  side  a  largv  ttrand  which  starts  from  a  part  of  the  anterior  colDmu, 
BOW  l)ecomiug  distinctly  ninrked  off*  as  the  pyramid  </V).  and  U  appnrenily 
loH  in  tbe  reticular  formation,  but  in  reality  paasoa  on  to  the  oriKiM>d  pyra- 
midal tract  of  tlie  lateral  column.  This  strand,  as  it  cro«es  over,  oi^nipletely 
cuta  off  tbe  head  of  tbe  anterior  born  frxim  the  more  central  fcniy  matter, 
«nd  fornu  with  its  fellow  a  lari^  area  of  decuwattng  6bred  between  the 
botOui  of  tbe  anterior  Gwnre  and  the  central  gray  matter.  When  u  •iirfMe 
now  of  the  bulb  ia  examined  the  decussaliou  is  oeen  to  be  cnecUsi  by  alter* 
Data  bundles,  pawnf[  now  front  riKbt  to  lefl,  now  from  tell  to  riftht ;  and  in 
timnaverw  aectiona  we  find  currei^puniliDftly  that  the  anterior  fiMure  appears 
boat  now  to  tbe  leA  and  now  to  the  riKht,  acconlinic  tui  the  tcclioD  cuta 
through  a  bundle  podciio):  from  left  to  nfUt  or  from  ri^^h  to  lell. 

In  wctiou  atill  hi^^lier  up  (Fie.  t^".  -^  and  4)  this  convpicuotu  ttrand  of 
fibna  craiiDg  oblionely  from  Ri<le  to  »ide,  will  be  no  lou^r  mcb  ;  dwumMt* 
ing  fibroi  are  »ecn  iIokbI  to  the  anterior  fi-iture.  but  tbiste,  of  which  wc  shall 
tptaJt,  praently,  are  of  different  nature  and  origin.  The  librc«  whii'h  in 
•Mtiona  bdow  wen-  *tKo  in  the  act  of  I'roMiiii);  un.-  now  giilhcnnd  into  ma«M 
«(  lon^udiiial  librv^,  the  pyramiiU  (Py.j  one  on  tuurh  «ide  of  the  anterior 
Cmuiv.  each  with  a  M-c-liotial  ami  of  u  roundnd  triangular  form  clearly 
narked  out  from  the  ourroiindiu);  Htruutunst;  tbe  wction  ia  taken  above  tbe 
deeoHUioD  of  ibe  prramidc  Or,  tracing  the  chaagta  from  beloir  upward 
ve  may  My  that  ihe  decussation  is  nuir  complete :  on  each  side  the  whole  of 
ibe  croaaed  pyramidal  tract  of  the  spinal  con]  has,  in  tbe  region  of  the  bulb 
bdow  tbe  level  of  the  present  Hctioiu<,  croascd  over  to  the  other  aide,  and 
joining  uiih  the  direct  pyramidal  iracr.  of  the  anterior  column  of  Ihe  cord  of 
the  Mme  side  boa  )>ecome  the  pyramid  of  tbe  bulb.  In  other  words,  tbe 
daOMMlioD  of  the  pyramids  is,  as  we  have  alrea^ly  hinted,  the  piissini;  00 
AxMD  «*ch  i^ramid,  and  the  crosnng  over  to  tbe  opposite  side  of  tue  ooM,  of 
Umm*  (ibrta  which  are  destined  to  become  the  orosiod  pyramidal  tract  of  tbe 
•piaal  curd  of  the  opposite  side,  while  the  reet  of  the  pyramid  pursues  ibs 
coune  uo  the  auae  side  as  the  direct  pyramidal  cracU 

f,  607.  In  the  npiual  cord  the  bottom  of  the  anterior  Anure  ia  separated 
from  ihv  central  canal  by  nothiu^  more  tbno  the  anterior  white  oommiHure 
and  a  onmiw  hand  of  gray  matter.  oi>mpii£«d  of  the  anterior  gnir  comouMare 
nod  of  part  of  ihe  central  Kelatinoua  Bubitancj.  During  the  diwusMtlon  of 
the  pyramid«,  the  dciAuuaiin);  lihrui  nuah,  as  it  were,  the  central  canal  with 
ita  surrounding  gray  mutter  to  dome  dtitance  from  the  bottom  of  the  anterior 
flnure.  In  aectiooK  atravc  the  deoussatiou  the  bottom  of  tbe  fisi-jre  duo*  not 
•eaio  npproocb  the  central  canal,  but  eootinues  to  be  removed  to  some  dis- 
tance from  il,  and,  u  we  pM>  upward,  to  an  inoreafin^  distance,  br  the 
inierpoNtion  of  ti«ua  wliiuti  connNU  Ltrgelv  of  deeiusating  RbrtM.  Those, 
however,  though  they  seeni  to  cuntinite  on  tlie  decussoltou  of  tltc  pyramids, 
are  ^liown  by  the  cmbryologtcail  nnd  degeneration  methods  to  have  no  noo- 
nectiun  with'the  prrami>h,  but  Iwloug  to  another  syatem  of  decussalioo.  Aa 
we  have  seen  (S  ^'^^  >  thi-  imtirtor  comminure  along  tbe  whole  Icarlh  of  tho 
Okfd  cuutaini  dccuuiiling  tilin-a.    SoBM  of  Umi*  In  tnc  Upper  part  of  the  cord 


■  rv  fibret  oraaaing  frnni  lli«  direct  pyrnniMal  IrsolDf  one  aide  ft  the  K^ay 

nintt«r  of  the  ntber  iJd«.  aiid  ai>  iiiuy  b^  rcirarded  ns  part  of  the  wbule  pyn* 

itiiiln)  tract:  but  aihont  un-of  dilTLT«nt  uriuin;  and  even  in  llie  region  of  the 

nciunl  <Ieniaiiitioii  nf  tbf  jiyrHUii'U  mxnr  »('  thi^  libnn  whtcb  enaa  nrer  An  nut 

hdoDg  lu  the  pyramiiial   Inti-t.     Tliix  fptcin  of  tIeciiawitiiiK  fibr<9  bei-iinii>» 

iBcnuin^ly  prutuiii<int  iilHivr!  t)it-  di'i'iiwvilioii  of  the  [lyminli].-',  iiin)  lhn>iij;b 

it  the  reuinl  Krvn  of  the  bulb  brtwi-vii  tlic  a-ntral  canal  itml  tlic  itnU-rior 

Amuiv  \m  niurh  in<'ri>iL-M.il.     Tbr  lilirv^  lui  ihi^v  rrnM  foriii  ii  iiii<Mt<<  linv  of 

Fttrtilion,  tho  rnpht  (Fig.  IS".  4.  ■'>,  r.).  wliicli  incniajiw  in  di-plh  in  lh«  upper 

fartri  of  the  bulb,  kod  on  fAch  nd<>  nf  tlic  rnphd  hiOp  to  brcnk  up  ih<'  i;riiy 

innttvr  (wbich  nnriously  fornxH)  th<;  niiUrrior  horns)  InU)  whnt  i«  uilli'd  tlM; 

rHietilar  JormoHon.     Wc  ohall   return  to  thi^  prwpnlly,  but  mity  here  call 

uuntlon  to  a  special  dcvolopnicnt  »f  tht'w  (kousaaliui;  libn^  wtiich  is  smo 

jatt  above  ttio  uecuaation  of  tht>  pyramids.     In  a  seotinn  at  Ihia  level  (Fig. 

147,  3)  II  atrand  of  fibrw  {supra  Pij.  •/««.)  may  be  seen  to  sUirt  chiefly  frooi 

the  gradk  nucleii*  but  also  to  some  extent  from  the  cunealv  nucleuE.  to 

SW««[>  round  the  central  gray  matter,  and  to  decuasate  ventral  to  this  between 

it  Kiid  the  bittl«nn  of  tlie  anterior  finure.     This  is  called  the  tuperior  (i:WuMn- 

(loij.  or,  for  renrans  which  we  abalt  Bee  later  on,  the  »en*or<j  dwfnition. 

§  606.  We  must  now  turn  to  the  poilerior  fissure  and  its  relations  to  the 
fourth  venlricle.  We  saw  that  at  the  be);innin<j  of  the  prrantiditl  decussa- 
ikta,  tbe  poaterior  bora^  had  been  thrown  backward  and  outward  ao  as  to 
iacnaae  w»  noeierior  columni^  The  [luateriur  fis&ure  is  ftill  of  ureal  depth, 
■o  iliai  by  tbe  increaae  of  depth  an<l  uittinteuao<*  of  depth  the  porterior 
column,  the  laierol  limit  of  which  ioalill  iiharply  marked  out  by  the  swollen 
bead  of  lb«  poMeriur  horu  as  well  lu  by  the  hif;heiit  posterior  rootlet*  of  the 
first  eervieal  nerre,  acijuire^  ul  this  level  In  mtticimum  of  hutk. 

Fri:>m  thia  |>uiDl  fom-»rd  the  depth  of  the  )>ot>ierii>r  fiuiira  and  the  dorwv 

ventral  diameter  of  Uie  posterior  column*  dimintiheii.     The  head  of  the  bom 

iFig.  ]8T,  2)  ie  thrown  Mill  further  oiilwan)  into  the  lateral  regions;  tbvel- 

opmcnlA  nf  gray  mailer  at  the  biu>c  and  to  iwme  extent  at  the  nock  of  tbe 

horn  iiif  tbew  we  nhall  tnmV  prrewillv)  cticmnch  (Fig.  187,  3)  donally  OD 

the  while  matter  of  the  oduninK;  sod  the  central  gray  matter  uppcnnt  to  riae 

doHHilly  at   the  expvnec  nf  thr  ponlcrior   68Siirc,   in   coiticidcnco   wilh   tbe 

'levi-lopMipnl  d«ficribed  above  nn  taking  place  on  the  ventral  *ide  "f  the  canal. 

Still  a  little  loriher  fornnrd.  in  a  section  lor  instnnce  (Fig.  \^~.  4}  n  little 

wnv  Ifrhind  tbe  apex  of  tlie  mUi>tt\u  tcrijtlorius,  the  central  gray  matter, 

tthtcli  still  Ibnns  a  rounded  maw  around  tbe  central   canal,  is  brought  yet 

nearer  to  tlte  pneterior  fiaaore. 

In  A  section  yet  a  bitle  further  forward  (Fig.  187,  5)  carried  through  tlw 
liinilcr  narrow  pari  of  tbe  fourth  ventricle  itself,  it  is  aaen  that  the  central 
canal  hna  opened  out  onto  tbe  doraal  surface,  and  that  ibe  gray  matter,  which 


nusniklamait  litR*:/a  (.asittnal  aieiiBMinni:  n.)aaldoa<iremb*ltor  tnci:  tt  miUBtm 
Milr  or  laftctor  ptdniwl*  of  lb*  ranbffluni ;  t  p  pilamal  pn*l(rinr  Mlumn.  lw.-lmi|ii»  oaaMlaa : 
o.p  luaAMi  toMlM  coIUMD.  AMculiu  ■ncltli:  r.  npho.  t.k.  UUnl  Iu>nii  a.^in.  nooleuaf 
•ka  B«dlaa  ptMM lor oaluiDn  ut  iir»cjlr  iiuulaiu.  f.p.  it.  iincli'iii  ul  UMicslatakl  poaMclur  uatama  Or 
rWHMtaoilMa'.cy  ■  in  >  ni<ill*n  illtMan  *iid  f.y.n.  (1.^  Ulvml  illTHI»n  nf  (ho Mint  i  g<  olMiy 
bartj':  ■<.«.  ««4bia  aMBHiry.  anil  el.t.  Uutml  acertotj  ulln:  fi.oL  lliIer4B*wr  Imyrt:  M  l.m. 
laMiml  iwu«D-l>Wi«n  niiclmii;  n.  s.  ueiwla  iiui'tow;  a  r.  mmiaoiuf  uilarlar  bom ;  /  m,  i*ll«a- 
Ur  tonaOcB^  I  g  lutvnuice of  Ralaula :  a.  r  r  I.  ii»lcrtori<K>I.UMl  p.t.t  1  |dM«iIoc  niot  nf  Rnl 
MnMalBM**:  XL  rwiorirtaatMHMctraem:  X11-(iitUUiartinn((oiat<>arTc:  ■■  XlLaurltwi 
al  Q»mm»  la  •;  Ihv  aurtM*  inky  In  lflw*il.  hOBDiw.  ihi«u(h  f.E'i.S.la  oooMrtloa  with  Uiv 
ntm  ft  llM  MtT* ;  (  X  Hiiun'  "f  auln  fat  of  1W  sbmo-|ihM  j  mwl-taso^otfirir  iMclaaa :  X. 
«.  ■atffUHlWUnribfi  n«iKat  nacl«U*nUt"u*:  IX.ii.BM«*idllig>a>t«<ll>e(liw>'pbu)rDKsl 
tiivl«a>i  V.«  OMMidlBC  cm)  or  lb*  aftb  iicrro:  Mb.  &«rtb  TWUMa:  tbs  opMlrai  or  hDlag  I* 
liBUcaHdbralhkb'tarbUnu;  uidniAaDd«.UMia>tb-Ilk«N«U0Bbrik>|n4Ktliwol«it  u*b»B«, 


r42 


THE   BRAIX. 


In  pn-vioii»  »ccitun»  «iirr»im<lc(l  it,  is  noir  cxftottd  to  the  Hirfitn*  i>n  tliv  H—t 
of  the  vculricle,  the  nitilioti  posterior  columns  bcin;;  ihraitt  ii»m]i-.  In  n  ui!l 
more  fonrnnl  »0(-lii>n  tFig-  187,  6)  this  gniy  matter  in  i:orTinp«>n(l«'niv  «ith 
the  ini-Tfiiring  nii]tli  of  (lie  ventricle  octupie*  a  still  iri<lrj-  atvn,  tlinittinj 
Still  ftirlher  Rtido  the  Darrowiiig  upjKT  enil^  of  llie  two  puttterior  tiilimin*. 

During  tlieso  ^ucceeeive  chsnge*  (he  large,  wide  posterior  (iHiih  exienia) 
piMierior  nnd  nicdian  pnaterior)  cctluiiiii^  of  the  cervical  apiiiul  i:<>nt  aad 
Itef^innitig  bulh.  arc  reduced  lo«Dall  dirniTiiioiiB  anil  iu  llie  eud  <lianii|>eaf ; 
but  licfore  we  fpeak  of  ilie  coune  and  fule  of  ibi?  traclii  of  fibres  euustituiiiig 
tbe^c  columiia  we  must  lurn  lo  ihe  imporiaDt  cliangee  of  ibe  gray  iimlier. 

S  609.  A  trniisverte  tection  itirniigh  llie  loner  eud  of  ibe  decutMlioti  <  Fijt. 
187,  I)  BboBB,  ua  me  linve  said,  few  difleretices  sa  rtfuards  thi?  grwy  luaiter 
from  ODC  taken  al  the  level  of  tLe  teuond  oervii-al  nerve.  Tb<-  cbotijtn 
noticc«bl«  are  muinW  Iliii  <'liiiu)^s  in  potiitinn  of  ilio  piuiic-rior  bortia,  the 
increnM'  of  central  gni^'  mailiT  around  tlie  central  ennui,  the  nppnjQcbt^tbe 
lateral  horn,  fVom  which  spring  the  root*  of  the  Hpinal  Bccvaaory  nerve,  to 
tbe  anlcrior  born,  iind  an  increnne  of  the  reticular  lorniiuiun  in  tbo  bar 
ventml  to  ihe  no^lerior  born. 

In  thi;  inidale  <)f  ih«  (Iccutantion  (Fig.  IftT,  2)  tbe  di-cuantiiig  Sbrc*  are 
cutting  the  hcud  of  the  aii(criur  horn  nway  front  the  Imm  of  tbe  horn  anj 
tbe  cenirnl  gray  imhiilHncr.  and  the  iiiolnteil  hflid  is  diminitbcd  in  *iie,  bnng 
aeparaled  from  the  surface  uf  the  «>rd  by  an  tncrciu>ing  (hickiH-oa  of  white 
matter.  The  lalcnil  liotu  iind  origin  of  the  ipinal  acccm^r)-  r>H>t  do  not  Rbai^ 
in  this  isolntioi),  but  an.'  driven  back  again  liormlly  towani  ibc  pufia-rior  toal 
to  join  ihe  rcticuliir  formsiion  which  w  iiicr^iing  it)  nrvn,  while  the  lairral 
column  of  white  matter  is  diminishing  in  hulk  by  (be  uiilulrawul  of  die 
pyramidal  tract. 

^ill  a  little  further  forward,  the  anterior  bom  aeeuu  at  firet  sight  lo  bave 
wholly  iltaajipearcd  ( Fig.  1S7,  3  and  4),  hut  its  <)uappeaniuce  is  cnjuei^ni 
with  an  increase  of  tbe  reticular  tbrmation  in  the  poaiiion  uf  the  lateral 
columna,  a&  well  tta  with  the  growth  of  lieaue  mentioned  nbove  l>eiucen  ibe 
anterior  fixture  and  the  centml  ^ray  matter.  In  fact,  between  the  anterior 
pyraintdi  on  the  vebtnil  dde  and  the  liirgely  increaaed  and  laternlly  es[Min(M 
gnj  matter  on  the  domil  nde.  a  large  area  of  peculiar  timue  now  L'xten<l*  os 
MOi  side  for  a  ctmsidcrahle  distance  frrini  the  niid<ilc  line  of  the  raphe,  en- 
croaching on  what  was  ihv  lateral  »>liinin  o|  white  matter:  and  a  com- 
<>punding  arvA  of  liniilar  tiwiie  miiy  be  traced  from  this  level  ibrongh  the 
higher  parla  of  the  bulb  up  into  the  jmns  nnd  crura  cnrchri.  'flic  timor  con- 
sists of  nerve  fibres  running  lrtin.->venu-ly,  loiigituilinnlly,  and  in  other  dirv^ 
liona,  so  ns  to  furm  a  nrlnork.  the  Inm  of  which  are  often  curved  ;  and  with 
llicae  fibres  are  Ibund  hmnchcd  nerve-cclU  in  eousidrrahie  number,  "iiuv  uf 
tbem  small,  both  librcs  and  cells  bifing  a*  elK>where  cnilwdde^i  in  neuroglia. 
Though  diHering  from  thn  ordinary  gray  mailer  of  the  cord  by  the  more 
open  cbarncler  of  it*  network,  it  may  Be  considered  as  a  liimi  of  gray  matter. 
We  may  consider  it  as  being  in  reality  the  giay  niniter  of  the  nppan-oUy 
loHt  anterior  honi  hmken  up  and  dispersed  by  the  pnaage  of  a  large  number 
of  tibieM  and  bundles  of  tibi'ca,  cG{iecinlly  of  the  decnssaiing  fibres  "poken  tif 
in  g  tiOti,  which  ^ince  they  curve  through  ibis  area  I'roni  tlie  middle  line 
laterally  are  called  arcuaie  or  nrcifunn  fibres,  inttmat  aifuatt  fibrtr  i  Fi{. 
187,  (>,/.  a.  i'.)  ti>  diatiuguish  ihem  Irom  the  nrtenml  arfuiile  fibre*  (J.  n,  e.) 
of  which  we  »hall  apeak  presently.  Fragmenis  of  more  compact  gniy  mai- 
ler, also  belonging  probablv  to  the  anterior  horn  are  teen  at  iutervaU  in  (hit 
Rrca.  Fig.  }f^'i,  a,  OB.  and  elaenhere.  We  have  st«u  that  nearly  all  tbe  way 
along  the  cord  the  gray  matter  of  the  neck  of  tbe  jiOEierior  liom  is  similarly 
broken  up  by  iMindies  of  fibm  into  what  we  tbetv  adied  the  reticular  foruta- 


THE    Itt'LB. 


748 


Itun  (Fig*.  176.  177.  f-,i-  p.  iind  r.f.  /.):  kikI  thi*  ftrvn  iti  tbv  l>ulb  though  it 
poan-wri  rhunicltfiv  nf  iu,  own  w  nit"  rnlM  the  ntif^ilur  formalwn.  la  tba 
n\nn  iKlcrnl  portinn  uf  this  fonaniioD.  thv  network  i«  man  omMi  nud  irregtt- 
t«r.  IIm>  Rbrm  nrv  liner,  nod  the  nerre-c«lls  nre  tnorp  nlxtntjiinc  ihiin  in  the 
intduin  portioD  where  the  nerve-oells.  except  id  the  immeiliale  neighborhuod 
•if  the  raphe,  ire  lew  numerous  or  even  absent,  uid  the  libr«B  are  coarstr. 
Thcae  two  p«TU  ar«  •ometime*  dietiDgiiished  ns  the  outer  or  laiornl,  and  the  ' 
inner  (It  iDcditn  formatioo.  In  ltt«  middle  line  the  Abrea  dialiocllr  interlace 
ud  tleciMWte  in  no  obU<)ue  nmoner.  some  running;  nearlj  vertically  in  ihe 
doreo-ventral  pluoe.  thus  i-oiiMituiiug  an  we  have  eaid  a  thick  raphe,  which, 
however,  nl  ili>  evlj^ea  |,>nidually  merges  intu  the  more  u|>en  network. 

i  810.  Within  ibc  iirou.  btiunded  oy  the  pyramids  veotndl)'.  Ihe  ex|>a»ded 
tnjr  mnUer  ilorMlly.  tbe  raphe  in  tins  niKldle  line,  and  the  it  bite  oiatlcr 
]al«TKlly.  cerliiiii  dintiuct  compact  cnaMM  of  ){niy  muiier  make  their  appear- 
ance. H>  we  p«M'  upward  lowunl  iht-  ])(>n*. 

Onoof  ihL-  nxHl  im|Mir(anl  nt' thtw  givea  riwe  H>  itie  olivary  body,  ar  hiftriar 
*iit<  vhicb,  an  <><■  have  M>t-n.  pniji-cl"  nit  an  oval  mam  (Fig.  IM,  o/.)  un  eech 
slHr  cif  ihu  |>yniniiili,  n:3(-hiiig  Irnni  a  level  which  is  Kimewhut  higher  up 
than  Um--  lr>wL-r  limit  of  the  pyrainid:<,  almost  but  not  i|iiito  to  the  jxin^.  The 
ulivary  ImhIv,  as  a  whole.  (iiiiiiRl-i  partly  iif  white  nuilttr,  that  ii>,  of  Hhn^, 
and  partly  af  gray  mailer,  si>ii)Him<r«  (■allt-^'l  tbc  nlivnry  nuclni*.  Thi»  latler 
M  dispowd  in  tiiv  form  of  a  hollow  I1u>k  ar  riirviMl  howl,  wilh  dn'ply  fohli-d 
or  plailed  walls,  having  a  wide  open  mnuth  <lirt!Ot»'il  iiiwanl  towani  ihv  mid- 
dle line,  ami  forward  tonarxl  llic  jwng  (.Fig-  1^' ■  ■*■  •'*•  6.  "'■)•  The  Ila*k  is 
filk'<l  within  hy  white  matter,  and  covered  ap  ou  it«  onLdde  with  white  mat- 
ter as  well  as  iraverwd  by  libm.  The  grey  Riftller  thus  forming  this  flaak- 
naped  nucleus  consiM  of  small  rounded  nervo-celU.  lying  in  a  bed  of  limie ' 
ahich  is  parllr  ordinary  iMuroglia.  nud  partly  a  fine  nervous  network. 

Lying  to  the  median  side  of  the  olivary  bwly.  immediately  dorsal  to  the 
anterior  pyratiiiil  is  another  small  mass  of  gray  matter,  in  the  form  of  a  disc, 
appeariuK  in  iraiiHvenw  sections  as  a  thick  bent  nx),  in  some  sections  c»ns!sl- 
of  t»t)  (larts  (Fig.  187,  4,  <//.  a.).  This  is  the  afttttoni  olirjtn/  »iif/riu.  A 
verj-  similar  h<Kly  ties  dor^l  to  the  ulivarv  niicleun.  in  the  lateral  reliculnr 
fnimation  ;  this  i* also  called  an  acccwory  of ivury  nucleuji.  Win^idiNlin^iiiibfd 
(F%,  IttT.  (i.  tl.  f.)  by  the  name  outer  ttpertturi/  niiclfiin  from  the  nbovc-mcn- 
tloued  (n'lrr  iirwjunry  micletu.  It  will  be  olxvrveil  in  thou;  iraiiKven**  «e<y 
Umu  that  the  inner  acemaurv  nuuleusis  W|)antle't  from  l)iv  olivary  nucleok 
by  a  bundle  of  while  fibrt*  (Vig-  Iff^.J.S,  fl,  XII.)  which,  ninning  venlrally 
from  llic  gray  luatlvr  in  the  donuil  region,  como  to  the  wiriixcc  between  the 
aoterior  pyrnmidn  and  the  olivary  body.  This  t*  the  hypogtomal  or  twelllh 
cranial  nerve. 

On  the  Burlace  of  the  anterior  pyramtti  itself  is  iwen  oo  each  side  a  small 
mass  of  gray  matter  (l-'ig.  1A7,  *■.  (I,  •■.  a.),  which  since  it  appears  to  be  cnn- 
oeci(«l  with  a  tyslcm  of  superlicial  transverse  fibres,  which  we  nhalt  descriiie 
ilirectly  as  th*  rjlrma!  anuatt  fibrt*  I  Fig.  187,  3.  4,  A,  tJ./  «.  f.),  is  called 
the  arnwfs  t»tete*t*.  It  seems  to  belong  tu  the  same  group  as  (he  accessory 
ulivca. 

Ljutlv,  a  small  fomewhal  dilfuse  collection  of  gray  maiti^r  i^  seen  in  *««• 
tioBf  OS  a  rnumlcil  mat«  of  irregular  furui  placed  lateral  to  the  reticular 
formation  (Fig.  1^7.  \,  o.  G.  a.  I.  ».).  Thb,  which  at  its  firat  a|i[imnu)co 
seem*  to  be  hmlded  ofl*  from  the  general  mat*  of  gray  metier  '  Fig.  1^7,  :t, 
a.  i.  Ill  and  which  is  probably  a  detached  |K>rlii>n  oi  the  base  of  Ihe  anterior 
liom  or  of  the  Uit-ral  ri-gion  of  the  gray  mailer,  is  calle<)  the  tattral  or 
aiiUro-laifral  nucleii*- 

Htnce,  bnides  the  diffuse  reticular  formation,  tbi*  rvntral  pari  of  the  bulb 


TRB    BftAIK. 


cvintniDR  mora  nhiirfily  <l<-fiuci]  collH-tionf  of  j^rKV  matter  in  the  nlivarv 
nack'ns,  nml  ihouiluT  hiHliesjuH  inciitioncd, 

i  611.  Wc  niUKt  niiw  mm  to  the  duraal  pari  of  the  hulh.  Here  in  thefini 
place  TC6  mual  <lwlingiji$h  belircen  the  jxirlioos  of  gruy  niait«r  which  are 
more  iinmediaiely  coniivcteti  with  the  cranial  nerve*  taking  ori)(iii  frrmi  ihi* 

fnrl  of  the  bulb,  and  the  poriioDB  wliicb  have  no  !>iich  nhvinim  iiinr>ei-ti»D. 
n  tiM  spinal  cord,  the  anterior  honi»  luippU-,  (u  ir«  luru  m-en.  ihi-  origin*  iif 
the  Mivceasive  anterior  motor  nerve»:  but  in  the  trni>)>l<irRiulii>n  of  thu  oirit 
into  the  htilb  the  anterior  honis  have  been  broken  up  or  ilMplovwl ;  nnH  tbr 

(lariK  of  the  anterior  honid,  serving  a.*  tlie  nucki  of  orisin  for  motor  ntnta, 
lave  been  translated  fruiii  the  vi'iiiral  Ki  the  more  doml  rt-gioiia.  Heac*,  il 
is  in  th«  more  dorsal  pari  uf  tin.-  ^ray  miilter  that  nv  have  to  wek  for  the 
nuclei  of  origin  not  only  of  afler<-iil  hut  alno  of  ni<?lur  cmnial  nervrjt.  Il 
will  )>e  conv«nienl  to  oonuider  all  ihisc  nuclei  nf  origin  if  crnniBl  ncrvM  bj- 
thenuclvr*.  and  we  may  here  eontine  oursclvw  to  the  grny  matter  of  Other 
natDrc.  We  inuy,  however,  »av  that  thiw  nucli-i  from  that  of  the  third 
tipr\-c  backwanl  aru  more  or  ftsa  clowly  luwoi'luted  with  the  griiy  matter 
immediiitdy  nurroundirig  the  wntral  cunnl,  Thi»  rrnlr'il  omt/  mattrr,  in  tli« 
namiw  *cnec  of  the  irrni,  i*  marked  out  Komcwhnt  low  down  (Fig.  IBi.  31 
by  tti«  tihrcn  of  the  Kmeory  deciissntion  winch  sweep  round  it:  it  appenn  in 
aectioUE  higher  up  a«  a  fairly  iliHinct  region  (Pig.  li^7,  4) ;  and  it  is  tais  pan 
of  the  gror  matter  which  is  exposed  on  the  floor  of  the  fourtli  ventricle  wheii 
the  central  cnnnl  { Fig.  187.  o,  li)  opens  out  into  that  ap«i».  We  but  ex- 
puaed ;  but  in  renlitv  the  irne  grar  matter  is  covered  by  a  Mi|)erficial  layer 
of  tiflnue  of  a  pecnlinr  nature  <  indicated  in  Fig.  IS7,  b.d.  by  a  ibiek  bUck 
line)  similar  to  tlial  which  is  found  at  the  hind  end  of  the  conus  medullaris 
in  the  spinal  cord. 

Wo  saw  that  at  the  level  of  the  lirat  cervical  nvrv«  cnueEdcnt  with  tbt 
horixontal  flalteuing  nut  of  the  (losterior  horuii  the  po^Urrior  coluiana  awumnl 
verv  large  dimenwions.  In  this  re|rion  f  Fij;.  1N7.  I )  they  eonairt  entirely  of 
white  mnlter — that  is,  <if  louKitudimd  ribn-s. 

At  a  little  higher  level,  however,  at  the  level  of  llw  middle  of  the  deouMi- 
tion  f'lr  example,  aii  inlet  of  gray  matter  (Fig.  1S7,  i,  m.p.  n.f  makw  its 
appenrancc  in  the  niiMlian  poMienor  column.  A  little  further  forward.  At  ibe 
level  -if  the  wtulilish.d  pyriiiuid^  it  will  he  Ken  (Fig.  187,  3)  thai  thi»  islrt 
il'  the  hind  end  of  an  invavion  from  th«  more  centraTlr  placed  grav  matter, 
•and  that  at  the  same  time  there  ha*  taken  plttc*-  a  similar  inroad  of  gmy 
matter  into  the  exteninl  |>osti-rior  column  (Fig.  ^>^~,'i.f.p.H.):  indeed,  a 
tllxhl  ext«Dsion  of  grav  matter  into  the  oxierniu  ixwtcrior  column  runy  be 
SMdi  even  before  this  (Fig.  IriT.  'i.  f.  p.  n.\  It  wilt  furtlwr  be  observed  Uiat 
UieBe  gray  masses  have  so  largely  memncUod  on  the  white  matter  that  iMth 
the  ntedian  posterior  or  liixciculus  gracilis  and  the  external  posterior  column 
or  fasciculus  cuneatus.  instead  of  bi'ing  simply  tmcU  of  while  tibre«,  as  tbey 
were  in  the  hinder  part  of  the  bulb  and  in  the  cord,  have  now  beoorae 
i-oliiniUB  Iif  gray  matter  covered  by  a  relatively  thin  layer  of  whito  flbrea. 
Tliw*  columns  of  gray  rontier  are  now  (called  reswctively  the  malian  piutt' 
rinr  nurluiui  or  itur/fiu/<itciruli  gKtcUi*,  or.  more  snortly.  the  ymeiU  nueirtta; 
and  the  fxUrtial  panttrior  nufieiu.  or  HtuteuA  ftueictt/i  eunfid',  or  the  runmf* 
titie/'K*.  From  the  ventral  asj>ect  of  these  nuclei  a  larger  numl>er  of  Abna 
]>nw  ventrally,  with  a  more  or  lea*  curved  course,  to  form,  at  we  hnvv  Mcn 
r$  H06),  the  su]>erior  deeuitMttiou  and  to  pursue  certain  ]>aihs  through  the 
reticular  fornmliou,  of  which  we  shall  s|)eak  later  on.  It  is  at  this  level  and 
for  some  litile  dlntauce  above  (Fig.  1>'i,  4.  -i.t  that  thew  nudri  aoinire  tlii^ir 
gn-fltcst  develiipmiiil.  Further  forward  (Fig.  1H7,  6),  when  the  fourth  VMk> 
tricle  has  o|)encd  out  antl  the  nuclei  of  the  cranial  nerru  are  becoming  can* 


THK    Ht'LH. 


rift 


anil  ibc  iMwIerioi-  coliimite  have  been  lliriim  asiUle  laierally,  both 
llirw;  iiiicli'i  Imrir  ilimiut^hed  id  sixe:  Hill  furt)i«r  furivartl  they  hecome  Btill 
UDiillcr,  moA  loWKrd  the  pons  they  it'^'ui'lir  (lUapfieiir. 

Tha  UMi  of  gclsiitioUB  suhelDDce,  fonaiDg  m  the  level  of  the  liral  cervical 
ntm  the  nrolkn  caput  of  llie  lioru  citee  lo  the  Hurfare  h«l  twparuted  (Vom 
it  hv  a  haud  of  tibrea  ( lo.)  of  fine  calibre,  to  nhieb  we  have  already  reftrred 
aa  belofigiog  to  the  S(\h  cranial  oerve,  luereaMM  In  bulk  tit  a  txiineivrhat 
higher  IpvcI  ( Fig.  187.  'i,  3.  *.  .7.)  and  forms  on  the  Kiirfai^o  a  nlight  projec- 
tion, railed  the  ItiAereU  <tf  Jiotando.  It  Aotiii.  howi'vrr,  bccnaiM  ihruM  v«d- 
Irmlly  bv  ihediverniMeof  the  poateriorcolutnna,  and  rDoro  and  morerAvemd 
op  !«■  tbe  tibrea  whieh  are  jcMnj^  lo  form  th<'  incrMwiuf  nvliforni  hmlv  (Fig. 
IsT,  4,  o,  6.  ID.  Uetaiiuog  this  |KwitJoii  ihe  ulct  of  gclatinntis  i^ubctniiw 
dimitmbea  in  sixe  further  foruun]  (Fig.  188, '. ^.),undev<.-nluallydi«op{>a)r». 


rtu.  m. 


r>9 


TO 


Wm^ 


^~i 


TUH, 


VHl 


CaJ. 


■ 

■  Ta>u«uM  nta  tM-ta  iiwr  Bui;3:d  iiik  fio*.  iRMSaaiKnTuii.i  Takm  It  tlw  Uiw  t<a,  FI*.  IM. 
V  P$.  HKinWt:  Jt.  trntUem  bcdT;  ('Am.  r*rtballuu>.  f.  mWi:  J.n.t.  ritcraiL/.A  1.  luMtiMl 
I  MOMM  nio:  L  bunatoof  niM  nuu  cdlre  la  tbc  lenUoular  ducIimis;  /  piHWIu  ko^mdlual 
'     bwil**:  ■./.(.  aueleiu  nf  IIk  Iho'U-iiIui  lent;  i  if,  iiiiirrlnr  nll)«:  ti  r, i    iiivlifut  niitialU  (lite 

Ifta  itHMa  ll  knanlloTMcif  hiimllnnlAlim  Iij'wMrti  ll  li  irmrmti;  t.t,  tutaUiiMotnoUiKlo; 

lr,a.aw«iidlaKniMoraRhnetvp:  Villi,  nuoieiuor  Uu-Hnnifenom:  Vlll.audliurr  nerrcohlelljt 

OaitofMla*  aaclllwr  taH:  Vllt.  u  millan  nueitua;  VllL;t  laU'rai  niulnn^  VIII,  j    «n— or? 

■Mtaw  ll' HrillMy  n*rTO.  IX.  Km*  of  rw>(  nfulMb  aonc  fanliw  llxniiKb  •irtdpllntt  mil  of  nafc 


I 


$fll9.  The jthret  t^  At  Mb.  It  b»  <ibvi«i».  fmni  what  hax  already  been 
said,  thai  the  arrangenienl  iulo  puitenur,  lateral,  aud  Bntnriiir  colunin*,  »o 
clear  and  delfniic  in  the  Hptnal  van\,  liecontea  broken  up  in  the  bulb ;  indeed 
it  will  lie  beat,  iu  treatini;  of  the  bulb,  not  Ut  atMmpi  to  tmoA  out  th«ae 
colonof,  but  toMneak  uf  the  coiirw  nf  the  MToral  tracts  into  whidi  thaaa 
oolnnM  may  be  divided. 

The  direct  and  cm«i  pyramidal  traoU  of  tha  pan]  unite  to  fiinn,  lu  <ra 
have  H<-D.  Ihe  pyramid  of  the  bulb,  and  so  pa*  (>n  bt  the  pons.  We  nood 
aar  nothing  mora  nt  prcx^nt  i-»iiccrning  this  important  pyramidal  atrand, 
exoepi  that,  tu  we  trace  it  down  fn^m  the  ponn  to  the  ipiiuil  oird,  il  Kirea  nfl 
to  thf  bulb  itself  tihrra  which  iniik':  ronneclions  with  the  lontor  libr«  uf  the 
ertuiial  nervM  [ir<ic««dinK  from  thi*  region. 

Coftceruing  ilie  course  taken  by  the  other  Ic8<  con'picuous  "  dMoending  " 
tract,  the  autero.|al«ral  descending  tract,  our  kiiowlmlgc  is  very  imperfect ; 
nothing  ilefinite  can  be  aaid  nt  preaent. 

The  rerebeltar  tract,  occupying  near  to  the  surface  a  poaition  wbid)  in  the 
■erfaa  nf  acvtioiu  ( Pig.  187,  V6.)  apjwara  naw  rather  more  eeotral,  no*  more 


748 


THE  miAi.v. 


(IofmI,  t'TcntiiAlly  jawa  int»  llio  rc*liform  b>iilj,  af  vluch  it  fortn>  a  iT^t 
|>Hrt.  and  ihiti  rcnch^s  llie  ccn?belluin.  Thi-  ■nlpm-liiCrnil  •KyiHliug  irad 
|Ki»ibly  III*')  mkcs  thp  Mtnc  coiirBc,  btit  tliin  i»  not  w  yet  iTcrtnin. 

The  median  pi:«IeTior  Irni/t  or  column,  becoming  tlie  fawiculu*  ^tnifili*. 
ends  in  the  gracite  Durleut ;  snd  in  n  similar  maniter  the  eitrriial  [■■(tiiiir 
column,  or  fasciculiiH  cuneatus,  enils  in  the  niedinii  and  lateral  miiMM  i>f  ibr 
moenle  nuclcuf.  As  we  fauve  seen,  the  while  mailer  of  tbiw?  Liiltimn* 
dtminiBhee  as  the  nuclei  iiiereaw;  and  the  Diidei  after  alworbiag,  ■<>  lOfpnk, 
ihe  white  maitc-r  diuintbheH  in  turn:  the  Hfcendini; d<-){en«rBtioii  itWrvwl 
in  thcDe  eolunms  Mo|ia  at  thene  Dudci.  Il  h  a  BUj[f;cMive  fact  that  as  thw 
nuclei  diminish  lurnnrd  the  restifurni  liody  increawa  in  hulk. 

The  remaining  Rhies  ol'  tbe  cord,  belonging  iwrtiy  to  Uic  amemr  colit^^ 
and  partly  lo  the  lulcml  column,  nol  giiihen-n  into  any  of  the  alxivr-ta^^H 
tioiied  tracln,  amieur  lo  fud,  chiorty  iit  nil  events,  in  the  reticular  funuamV 
»r  ihe  Itulb  it«eir,  though  vnmL-  an-  oarriml  on  to  the  higher  parts  of  (he 
brain. 

i  613.  TlniM,  «r  th«  vtirii)ii»  tracU  or  stran<la  of  Ihe  aftinal  cord,  two  tath 
are  known  dcfiuildy  and  cvrtoinlv  to  pun  as  oonspicuouH  unbrukeu  MraiKH 
thniiigh  thu  bulli  to  or  iVoni  higher  parts:  namelv,  the  |>ynimidal  liact  m 
th«  cerebrum,  luiil  tlic  corebelliir  tract  lo  the  oercbcllum.  All,  or  nearlv  all, 
the  reM  or  the  longiludiiml  fibres  of  the  coni  reiiching  lh«  bulb  and.  as  ura* 
ncknow  iit  jm-^ini,  in  some  pnrt or  other  of  the  hulb;  and  we  m»y  infer  that 
romcor  other  ncrvi^cells  of  the  bulb  H-rvc  as  relays  to  oonncct  Uieae  fibres  itf 
the  rord  with  other  pnrle  of  llie  braiiu 

The  gracilc  and  cuneale  nuclei  sttuid  out  conspicuously  as  rclap  nf  (hit 
kind,  nnd  through  them  the  posterior  columns  of  the  cord  make  Mcoiidarr 
connections  on  the  one  hand  with  the  cerebellum,  and  ou  iIk-  other  luuiJ 
with  various  regions  of  the  cerebrum,  We  have  »aid  (^  607)  that  6hra 
passing  ventrnlly  frtim  the  ifracile  ami  cuneale  necH  sweep  in  a  cui 
couiw  tlirougb  Ihe  reticular  formation  ik.->  tlie  internal  arcuate  fibres 
187,/.  i.t.).  The  hiudmoHt  of  these  form  the  ^uperinr  decusHatiuu  all 
referred  to  as  seen  in  iiei-tioua  of  the  fore-ptirl  <>f  und  in  front  of  the  pyramidal 
■lecuuation  (Fig.  1K7,  3,  mpr-i  Pi/.  •Ire.}.  AAvt  ducuwaliaR  Teiiinil  to  the 
ccutrnl  canaf,  thrai^  librcs  fonn  an  area  called  the  inter-tSirary  la^r  (F1||. 
187,  \,  in.  oL),  lying  dorsal  lo  the  pyrHmids  between  two  (lie  <ili%'ury  Dttclei. 
This  layer  may  bo  regarded  as  the  iiind  end  »r  ht^^inninji:  on  each  side  of  a 
remarkable  longilndinnl  strand  culled  the-  fiUft  I  FJNy.  I'^U,  B.  F.,  189,  F.), 
iii  the  ronnei'tions  of  which  in  the  front  part  of  the  brain  we  shall  speak 
herenftcr.  Thus  these  two  nuclei  are  ihe  source  of  librvs  which  cnw*  lo  ibe 
other  )iidr  of  (he  bdlb.  and  rcncbing  the  inlcr-olivary  layer  ijonni  to  (he 
pymniidM  run  up  lo  higher  parls  of  the  brain  by  the  fillet.  We  may  add 
l^nl  llic  lomiation  of  the  tillct  i*  also  probably  lumslcd  by  Hbres  fn>iii  n  imct 
which  lies  just  dorsal  to  the  inter-olivary  layer,  and  is  <leriv<-d  from  the  nntr- 
rior  columns  of  the  cor^l.  Besides  it<  fibres  of  descending  dr^nemiion  thv 
anterior  column  contains  fibres  of  ascending  degeneralion,  and  tbcM'  riw 
donally  in  tlie  bulb  in  form  llie  tract  iu  question.  Though  the  whole  Iract 
is  of  some  leoxtb,  the  component  fibres  appear  to  be  short. 

The  gracile  and  cuneale  nuclei  ^ive  rise  also  to  other  fibres  whii'h.  though 
also  iweepiog  reiilrally  and  croMiug  to  the  other  side,  do  not.  when  they 
m^h  tlie  iulei^olivarr  region,  asaiime  a  longitudinal  direction,  as  di<  the 
libm  Innning  (he  fillet,  but  as  external  an-uate  fibres  (Fig.  1^7./ u.^.) 
pursue  n  course  nbtch  is  at  fir«t  vititral  alone  the  side  of  ihe  anterior  fissun; 
nnd  linn  lali-ral  over  the  vcntnil  surface  nf  tue  ]>yraniid  and  olivary  nucleus, 
by  which  path  they  reach  the  hiUnd  sutliiccof  tbc  bulb,  aivd  do  the  rmtilorm 
body  aiwl  (.■rrebolUim.     In  ibis  way  the  two  nuclei  iu  (lueetion  contrihutv  ti> 


I 
I 


i 


opposite  «de  nf  th«  bulb.  Th<»e  cxtenuil  nrcuntc 
n,  «hich  as  llVy  sweep  round  ihe  veulml  siirfnce  of  ihe  pvrniaid  tmrcnfc 
arcuate  nucleue,  ihoti^b  lli«7  vary  much  in  iudividiial  brniiKt,  fonn  a 
(■oDNiIcrable  |M)rtiua  of  ibe  while  iiinller  neto  on  Uie  ventml  and  btlcrul  tot- 
Ciuvt  of  the  bulb  :  it  ta  by  tbeiu  ihai  the  olivary  nucleus  is  covered  up. 

The  cuoeate  aod  Krocile  nuclei,  bMltlea  (hb  eroaaed  and  Kmivirbnl  nnintl- 
about  cuDoectioD  vrilb  ibc  rettliforiu  body  of  the  oujioute  aide,  are  licliui.'ttl 
10  hare  more  direct  connection  with  (be  rcsiliforni  ImiIv  nf  the  unie  sido  by 
■MUU  of  fibres  whtt^'h  piua  by  a  nicirc  or  Uta  dirvrl  lateral  path  IVom  t  htm  to 
It.  Accepting  tbiH  view,  ne  may  mv  that  the  twn  nuclei  are  cooiiectoil  nith 
the  oppcnte  aide  of  the  rereWlluni  by  I'xlcrnal  tin-tiate  fibreti,  and  with  tlic 
Mue  Bid«  of  the  cerebullum  by  the  other  lihrt^  juvl  uienliune^l.  In  any  vote, 
(he  conne«tiun  betwt«ii  the  two  unclct  and  ilie  c^rebollutn  ia  larj^  and 
iniporlaot. 

Tbu*  ibe  in)|H)rli)nt  »(i«nd  i>(  fibrrv  which  w  called  in  tlic  bulb  the  re«ti- 
fona  body,  and  hi):her  up  thv  interior  i>edLinc]c  of  tho  erri'lielluiu,  is  con- 
iirctrd  with  the  spinal  conl  in  two  chief  ways:  dirvctiv  by  ni««Dii  of  th« 
cercbrllar  tract,  and  iiidirecllv  by  means  of  the  euneiUc  awl  gracile  nuclei, 
which,  aa  wc  haro  Mid,  diminish  in  bulk  forward  ss  the  ru>tifiH-:n  bmly 
iorrtfiMs.  By  tbo  relay  of  the  gracile  nucleus  it  is  brought  into  couiiectioD 
with  ibe  mcdtui  poetvrior  column  alonj;  the  whole  length  of  the  cord,  and  m> 
with  Ihil  diririon  of  Ibc  {Kisterior  roots  wbich  (S  578^  in  each  of  IIm>  aeveral 
•|ni»l  aervc*  goes  to  form  that  column.  Uy  the  relay  of  tbe  cunente  nueleua 
K  »  brought  into  connection  with  such  i>art8  of  tbe  exlernal  posterior  cohiian 
■a  cod  in  that  nucleus,  and  thus  probably  with  oilier  &brea  of  the  i)0*t*rior 
nols  of  ibe  upper  spinal  nerves.  And  if  we  admit  tluit  the  cerebellar  irael 
itcoanecied.  by  the  relay  of  the  vesicular  ej-linder  or  by  other  ocrve-celb, 
with  tlie  rest  of  the  pii*ierior  rooia  of  tbe  apinal  nervcw,  we  may  condnile 
that  tbe  rtatifiinn  biKly  is,  by  ni<-an;>  »f  thnw  relay*,  a  prominent  contiuua- 
lion  of  all  tb<-  xpiiial  [»»li'rior  root*. 

Tbe  rraliforni  ImmIv  and  m  thfl  c«ndwllum  is  also  specially  cnnncoled  with 
the  olivary  Ividy  of  the  oppovilc  «idc ;  for  when  in  young  animal*  one  ilde 
of  tbe  ccreMlum  is  re^novet),  the  olivary  body  of  tbe  opponite  pidc  atrophica. 
Till)  (^Mirw  of  th(^  Rhres  niainlaining  tliis  connection  is  not  ua  yet  nocurately 
known,  but  they  nrolMibly  na«H  from  the  olivary  nucleus  of  one  nde  tlirough 
tbe  inler-olivarv  layer,  niKi  m>  latomlly  through  the  reticular  formation  of 
the  other  side.  I>iistly,  we  may  add  that  a  imct  which  is  aonietjmes  included 
in  the  mtiform  bodv  as  its  median  or  inner  division  has  quite  a  dilltTeiil 
origin  from  any  of  the  above;  the  Ubren  wbiob  compose  it  cume,  as  wc  'ball 
•ev.  from  the  auditory  nerve. 

The  fnnher  connections  of  the  bulb  with  tbe  cerebrum  it  will  be  beat  to 
leave  ontil  we  come  to  deal  with  the  structural  arran;(ement  of  the  rMt  of 
tbe  brain. 

Meanwhile  eoouch  haa  been  said  to  show  that  ilie  bitib  iliflera  very  mat«- 
riallj  in  Mmcture  from  (he  apinal  cord.  The  gniy  matter  of  the  Iwlb  is  far 
mure  complex  in  hj  iia  nature  tluui  it  tliat  of  any  luu-l  of  tbe  cunl ;  anil  tl*e 
arrai>i;emeut  of  tl>e  several  Mnindx  and  irai-(a  of  hbrui  i*  far  more  inlticat*. 
The  Hiruciural  feature*  on  the  nhulL-  (icrtiap*  uigfcctt  that  the  main  functiow 
of  the  bulb  are  twofuld ;  ou  the  •me  hand,  it  *cem*  titttvl  to  Mrve  an  a  bond 
eentr«  governing  the  Kpinal  oiinl.  tbo  variitiiii  rein*  of  which,  with  ibe  ex- 
eapthma  rio(e<l.  ii  hi<ld>,  »■  it  n>-r<-,  in  il»  bnnda:  on  iho  other  baml,  it  appare 
no  Ina  BdH|)le<l  to  act  una  middleman  between  parts  of  the  apioal  c<^  liehiw 
and  varioua  regiaiiK  of  the  brain  aboTb  Aa  we  shall  tev.  ex|wrimeDt  and 
nhvrvntinn  ^vc  Rup|>ort  (o  tbcM  aiiggcaUou. 


TUB    BWATX. 

Tne  DisroatTioN  and  (kkMKecTtojts  op  the  Oray  avu  White 

Matter  of  the  Braiv. 

THK  (iBAV   MaTTRB. 

S  614.  At  we  fuu»  up  fiMin  the  btilb  t«  the  bigbcr  prb  nf  the  brain,  tbe 
iliflt-ri'ii  lift  ion  tif  Ihi-  gniy  timtror  into  niorv  or  Ton  npnraU  nuun*.  whkh 
nx-  linvo  Ki'ii  Imgiii  in  tho  bulb,  bccooH*  still  inoro  Mriking.  W*  htre  lo 
(listiDgtiiith  n  Urge  number  of  ttmu  or  collection*  of  gray  ninit«r,  mntr  or 
low  rvgulnr  in  form  mifl  morv  or  Icm  shnrply  HclinoaJ,  Jrom  (1m-  giirmuu'liii; 
white  matter;  to  such  colloctioiis  the  sercnii  temii  corpus  locus,  nvurlctu. 
hik)  tho  liko,  hiive  from  time  to  limo  been  given,  llwse  arcu  or  eollvctioDf 
vnrv  grciitlv  in  si7«,  in  Ibrm.  nnd  in  histological  chiirttct«ra;  ibey  dilTer  frooi 
eacK  other  in  the  form,  eiz«.  features,  and  arrnngemeDt  of  the  ncrw-celb,  b 
tlie  ehantctera  of  the  nerroiis  network  of  which  the  nerve-cells  fortD  a  part, 
and  especislly  pcrhapi'  in  the  extent  to  which  the  more  distinctly  ertr  inattff 
is  traversed  ami  broken  iip  by  bundles  of  white  fibres.  tiuJocff  by  Uir 
analog}' of  the  epiiial  cord,  us'well  ns  hj  the  r«suhe  of  ex|>eriineDtg  and 
obaervntjons  direcled  to  the  brain  itself,  we  are  led  to  believe  that  tht  com- 
plex functions  of  the  bruin  arc  intiiiiatelv  aseocialed  with  tht«  gray  matler: 
and  a  full  knowledge  of  the  working  of  ite  brain  will  carry  with  it  a  LdokI- 
edge  of  the  nature  and  meonin];  of  the  intricate  arnuigenMnt  of  the  cerebral 
gray  matter.  At  present,  however,  our  ignorance  as  to  tbtse  things  a  grou. 
and,  though  various  theoretical  cloniHcations  of  the  several  colleeUoiu  of 
fny  matter  have  been  proponed,  it  will  perlmjia  be  wisest  to  content  oat- 
aelvea  here  with  a  very  broad  and  nmple  arrangement.  We  will  divide  tbt 
whole  gray  matter  of  the  brain  into  tour  eatogori<«  only:  1.  Tlio  oentnl 
gray  matter  lining  the  neural  canal ;  and  thin  we  may  coiwdrr  the  nuclei  «t 
the  I'raiiial  nerves,  some  of  which  arv  cliisclv  ammeiated  with  iL  '2.  Hw 
superlicial  grity  matter  of  the  roof  of  some  nf  the  main  divifion«  uf  the  bnin. 
such  ax  ihnt  of  the  cerebral  hemispheres,  and  of  the  cerebellum.  3.  Thr 
tntermcdiftto  gray  matter  more  or  Icm  closely  connected  with  llie  crnrt 
Gtrebri.  4,  Other  collections  and  areas  of  gray  matter.  Wn  will,  moiv- 
over,  confine  ourselves  at  present  for  the  most  part  to  their  sonemi  fe«tur«i 
nnd  topography,  reser\'ing  what  we  have  to  aay  oonceniing  tltPir  histnlog' 
vlinractcrs  for  another  oocai>ioR. 


1.  Tht  Ointral  Omj/  Matter  and  Ihg  A'lielti  tf  Ihe  OnmifU  2fant». 

$619.  The  veiitrldea  of  the  brain,  like  the  oeiitral  caual  of  lite  sr 
eerd.  <>f  which  they  are  a  continuation,  are  lined  by  an  opithdiiim  whic 
in  ^lerat  a  single  layer  of  columnar  oelb  said  to  to  ctliate<t  througboalT 
thotigh  it  U  olten  diHicnIt  to  deuionstrnte  tlte  eilia.  Beneath  this  opiibelliim 
Ii4v  a  layer  of  somewluit  [wciiliar  neun>ulia,  fonuing  with  the  epilhelium,  •• 
wi.>  luivv  said  <$  RII).  till'  rpfiiilttma,  wliicli,  well  devel(^>e<l  in  the  tltMir  of  tiia 
f;>iirlli  vrntricli-  nnd  in  the  walls  of  the  third  ventricle,  and  of  tlw  atiMdl 
i*  ibin  nnd  scanty  in  the  lateral  vcntridtw.  ncncatb,  and  more  or  Mn  a 
nectdl  with  the  I'jwndyma  in  tlie  eith^  nnd  Hoor  of  tbu  third  veniriclo.  b  I 
fnirly  conspicuous  layer  of  gray  matter,  which  i*  well  developed  in  the  jwut* 
of  the  floor  exposed  on  tlic  ventral  surlnce  of  the  brain,  and  known  an  the 
lamina  terminalis,  the  anterior  and  posterior  performed  spaicK«,  the  tubv 
cinereum,  etc.  This  layer  is  not  continued  forward  inin  the  laiernl  v<-itlri> 
elea  of  the  cerebral  heniiBphcres,  but  it  ie  w«ll  developed  iHickward  along  iht 


TUE   GRAV    llATTBIt. 


T4tf 


I 


I 


<FttS.  191.  lf)3>.  and  in  lliu  fitior  t>r  tbts  fmirili  vvnIriclF.  luiil 
lh'niu)[b  tbvi  l>iilb  Ikvoidm,  m  we  biivc  Men  ($611).  rontinuuus  tvidi  ihv 
oDDlrnl  tny  nwticr  of  tin-  cord.  Tbc  itcrvo-fcllfl  of  tbb  graj  nmttcr  are  imi 
Uw  «  h»ii'  rniall  iind  in  many  plan^  scanl. 

<i  616.  Thr  Fcvcrnl  ronis  of  the  cninial  nerrps  from  thc<  ihird  ticrr<^  hnck- 
wiril  niKv  be  tnictHl  within  llie  bnin  Bul»tnnce  to  apccial  miltH'tions  of  gray 
nijitlrr,  callfid  the  tttiriri  <if  Ihe  cranuit  nefif».  »onie  of  which  lie  (ilnap  u(>on 
tbr  ihe  I'dilrnl  gray  nuitter,  while  others  arc  |tlace(I  at  eutno  dislunce  from 
it.  The  optic  utTTe  and  what  ia  w>m«Ulii«B  called  the  olfactory-  nerve,  nsniely, 
tli«-  olfactory  bulb  and  imcl,  mar  advaDta^>ua1r  be  dealt  iviih  ufiart.  aiuce 
dim.'  two  nerves  are  not,  like  ifie  other  cranial  oerreB,  Dimple  outgrowths 
ttotn  the  walls  of  die  original  nenral  canal,  but  are  in  reality  enlougaied 
Tcaii'le*.  budded  off  from  the  neural  canal,  the  caviiitw  of  which  have  been 
obliieraied.  We  may  add  tbat  gmrt  uf  tbi^  rvtitm,  and  of  the  gray  mailer 
of  tl>e  olfacion.'  tract,  may  |M^rlm|i9  bi-  cc)UHt<kT(.-d  ua  corresponding  to  Llie 
nuclei  of  which  ne  un*  niwakirig.  tin-  rrtiiial  and  nrojier  olfactory  &\>n*  I>dng 
MUkeeted  with  them  very  tiiiK-h  n«  thv  iibrca  of  tho  n-maining  cniniul  nerves 
an  eoanected  with  llieir  rci>)K'(-livt!  nuclei.  In  thir  brain  tb«  Mgmi.-ntnl  regu- 
larity of  the  nejve  nHita  :ici  <:-'tii!-|)icut>u«  in  the  iiiintil  cunl  w  very  greatly 
obacored.  We  nball  have  aomcthing  to  «ny  on  i.tii*  pi>int  Intrr  uii ;  bni  at 
preaent  we  may  be  cunlrnt  to  trnt  ihcM<veral  nerve*  in  a»imple  to[iiitimbical 
naanner.  Tli«-y  may  ba  seen  in  a  vvnlnd  view  of  tbe  brain  i.Ftg.  fS*},  C.), 
leaving  the  bniin  at  rartoua  level*  by  what  is  exiled  ihdr  "i>iiperficial 
urigin  ;"  the  third  nerve  iwiiing  in  front  of  ilic  pons,  and  th«  biat  or  hrj'W- 
glwml  itrriebing  back  to  ihc  hind  end  of  the  bulb.  Part,  indocd,  ol  tlie 
rkvenlh  nerve,  tbc  »ptnal  accessary  ncrrc  nroperly  so-callMl,  maLea  con- 
DfCtiona  wilfa  th«  Rjiinal  con)  Ivelow  the  bulb  ii»  far  back  as  tJie  rixtli  or 
wreoth  ecrvicsl  nerve,  or  even  loner ;  but  this  part  may  by  ibcw-  codihh:- 
tiana  be  distingnisbed  from  the  remaining  part  of  the  nerve,  an  well  as  from 
all  otber  cranial  oerrca.  I'be  nuclei  to  wbicb  Uie  nerve  roots  may  l>e  traced 
witbia  tlie  brain  anbataDce,  sometimes  spoken  of  as  ibe  "  deep  origin."  range 
in  [KviiiaD  Irom  Ibe  binder  purl  of  the  bulb  lo  the  bind  end  of  the  third 
ventricle.  Tbe  nurleus  of  the  byp»i{liiH!<al  nerve  begins  ut  ilie  bulb  Just 
above  the  decutaation  of  tbe  pyramiiff.  the  nucleus  of  the  third  nerve  ends 
bennttb  the  hind  end  of  tlie  flour  of  the  third  ventricle;  and  all  tbe  rest  of 
(he  nuclei  may  l>e  broadly  dtwcribed  oa  placed  between  th««e  limits  in  i,-arious 
|iarbt  of  tlte  llixirof  the  ceuiml  canal  or  in  adjoining  *lruciuR»,  though  part 
of  one  nucleua,  iiamely.tbat  of  the  fillb  nerve,  can  lie  tnu-ed.  ad  we  iJiall  we, 
back  Into  tbe  sfiinal  cord  as  far  a*  tb«  second  ocr^'icnl  ner^-e.  and  probably 
eximda  Mill  farther.  Fig.  l!)-t  ba  diagnm  showing  in  a  rougbly  aptiruxi- 
oiftta  manner  tliv  nuclei  of  tbe  «eveml  ncnta  a*  tbcy  wouUI  nM>enr  in  a  binlV 

rvlew  of  tbe  floor  of  the  miutildol  and  founh  ventricle  looked  at  »n  tbe 
■I  atpcd. 

S  617.  Thf  tu*/Jtli  or  htfpogipMol  ncnv.  The  iincleus  of  this  nerve,  which 
it  will  i»  convenient  lo  take  fiivt  (Fig.  1I>:!.  XIL),  is  a  long  column  of  gnj 
niaittr  lying  in  ihr  bnlh  parallel  to,  and  very  cl««e  lo,  the  median  line.  It 
rcaebeafrom  tbe  hinder  pari  of  the  fourth  ventricle  at  hIhiuI  the  level  of  the 
him)  end  of  the  auditory  nucleus,  as  far  bn<-k  as  beyoiid  tbe  bind  end  of  tlte 
olivary  liody.  Ai  its  extreme  bind  end  or  l>e^nning  (.Fig.  161.  'ii  it  occu- 
pica  a  venlral  jrasilixn  and  is  n  jwn  of  tbe  anterior  born  ;  tnenoo  il  grmdually 
risee  doraolly  (Fig.  1M7,  -i.  4, 6),  but  so  long  a*  the  central  caDal  remaJiw 
oloeed,  oootinues  to  oecujiv  a  distinctly  ventral  p<isition  in  reference  to  ihe 
oentml  canal ;  in  iu  front  |>art  it  is.  by  the  o^itucup  of  tbc  fourth  vrnlriclu. 
Imxight  into  an  ap|karenily  more  dornl  poHtlon  (Vig.  1^7,  (t). 

The  nucleus  cou--tieta  fuainly  of  large  nerve-cells  with  distinct  axis^yliixler 


760 


THE  BBAIX. 


nracccMe,  which  tliuiigh  [lurauing  ■  •omewhnl  irrcgiiltir  cuurtp  niiiy  br  tncti 
into  the  fibrai  of  the  ucn-e.  These,  xtarting  rn>m  the  renlntl  *ur^nc«  of  At 
uuL'leuH  %]oag  its  Icuglli.  ruu  vciitnilly  thmiigh  lli«  ivtinilitr  formAtlon.  Bttd 
making  tlietr  war  in  n  n-t'uf  at  huixtli'v,  1x^1  necn  thi^  oliviuy  uuolriu  on  ibr 
Iai«nil  eUif  «licl  tlio  pyramiil  n»<l  nxiltiin  nccxMory  oliro  on  ibi-  mrHiaa  itdc. 
f^tan  the  Rirfacc  nloii);  tho  groovo  nhicb  MpnniKs  the  pyrttuitl  fnun  (lie 
olivBrv  bodv. 

5  6l8.  JlSf  iii'dM  or  ^lonnphari/ngtnl,  UhUi  or  raz/w,  ouil  flrrevtA  or  ipkutl 
(ir«MOrif  nent-A.  It  will  hv  ndTKiilagoous  to  consider  these  thne  owrc* 
togeth''.r, 

in  the  spiiinl  ncctMOry  nervM  we  miiEt  dislinguiah,  ■»  we  b«x*e  aid.  two 
rarts :  the  "  spinal  iu!ce»ory  "  profipr.  Ibrntod  by  tite  roots  which  come  mS 
noiu  the  oervic«l  suinnl  coni,  reaching  as  lar  down  as  the  sixth  or  seventli 
cervical  aerre,  and  the  "bulbar  acceBsory,"  whoM  roota oome off  from  the 
bulb  Just  below  the  vagus. 

The  spinal  acce^ory  proper  takes  ori);iu  in  the  ({roup  of  oellti  lyiQf;  in  the 
extreme  lateral  mitrgin  of  the  anterior  horn,  from  whence  thi:  fibmt  pruoeej 
(llrectly  outward  through  the  lateral  column,  and  bsuc  from  ilie  curtl  along 
K  line  imraeilinie  belnceii  the  anterior  and  jiosterior  roota;  the  up[ier  roa* 
undergo,  uiih  the  portiDu  of  tlie  luientl  horn  from  nbich  they  vpring,  tht 
shiftUtg  spoken  of  in  $  flOti. 

The  Dulbar  aoceeaitry  starts  from  an  elouiated  nucleus  in  (he  bulb  whidi 
U  common  to  it.  to  the  vagus,  and  I'l  the  |i1o««i>-|>har%-iigcaI :  hrnee  we  ban 
taken  ihc*e  three  uervea  together.  TbiH  (Fig.  I'J^i strviclKv  further  fiirwaH 
Ihnn  the  hrpoglownlnudeua,  reatdiiiig  thi^  level  of  tbetmiuvvnw  tibn^catM 
Eirin;  acuKticui  (Mr.),  hut  doea  Dot  extend  do  far  bi^hind. 

In  transvcnw  nectiou*  of  the  hoth.  which  jMm  a  lilth-  Iwlnnr  nn<l  a  liltir 
above  the  point  of  the  calamus  scriplorins  (Fig.  167,  4,  ■'>),  too  uuulet  or  rol- 
ledtooBof  cells  art- seen  in  the  gray  matter  round  the  central  caoal.  The 
more  rentral  one  it  the  hypoglonal  nucleus,  the  more  dorsal  one  the  hegiu- 
ning  or  hind  pan  of  the  conibiDed  accoesory-VHgo-gloMO-pbarii'utreal  nucleiu. 

When  a  tiltlc  further  forward  the  central  cansropetiB  out  into  the  fnurtb 
t-cntride  *by  which  change  the  hypoglacaal  Ducteua  (Rg,  187,  fi  d.  xii.)  U 
brought  nearer  to  the  dorwl  surface  in  the  floor  of  the  fourth  veiiiricle)  ihb 
combined  uucleus,  increasing  in  breadth,  is  ihrowu  to  (he  aide  aud  H.-vumosa 
more  lateral  pontion,  lying  now  on  the  side  of.  but  still  nuniewhat  donal  to, 
the  hrpcigliissal  nucleus,  between  it  and  the  noir  diuinishitig  gtacUe  tiuclMa. 
In  thtii  pDtiilion  the  nucleus  appeum  to  conun  of  two  part*,  a  tnedi 
laleml,  the  ujedian  part  having  ouiisjiicuuui  oervfr'^jelLi  of  modt^rate  luse, 
]at*.-Rt]  iKtrt  having  hut  few  cd^ls,  una  thute  of  small  «»:.  From  this  i 
the  niicli-U£  runs  lurward.  nainiaiiiing  nearly  the  same  pinilion  iu  the  floor 
of  tbo  fourth  ventricle,  but  gradually  becoming  thlaa«r,  and  ends,  oa  w«  hare 
c«id,  at  about  the  level  ot'  the  siruc  acuaticfe  on  the  donal  aiirfiMO  oorrespood- 
iDg  on  the  ventral  surface  to  a  level  a  little  behind  the  hind  margin  of  the 
pom; 

From  lhi»  combined  nucleu:*,  biil  chielly  from  the  median  |mn.  tibrea 
fiwcep  in  a  ventral  and  lateral  dinx-tion  through  the  donal  part  of  the  reiie^ 
illar  fbroiation,  paw  ventral  to.  or  in  Mute  caM«  through  the  gelatinous  Mb- 
atancc  and  the  Ntraml  of  fibres  connected  with  the  jiflh  nerve  (Fig.  187,  V. 
a.),  and  rcudi  the  onrfuce  of  the  hnlh  on  its  lateral  aspect  iu  a  line  bHWMa 
th«  olivary  and  rcsliform  bo<lici  ( Fig.  186,  C).    Along  this  line  may  bo 


wna. 


I  (Pig.  180,  C,\B««-ricaof  roots;  of  tlieM  the  lowest,  the  acoetaoryroota,cpriag 
^n-nin  the  hind  part,  the  hi^^hesl.  the  g I oero- pharyngeal  roots,  from  lh«  front 
part  i.nnd  it  u  thcee  ee|>e<-iallr  which  pierce  tlie  gelalinoiu  stibstaao^^E^. 
ilX.  a),  and  the  intermetftaie,  tlie  vagus  roots,  from  the  middle  part  iif 


TIIK    ORAV    MATTER. 


751 


bined  nuckuB,     Hence  we  timr  speak  of  the  bind  part  of  (li«  wlmlc 


Il«  VI 


I 

I 


I 


beiDft  iht  acve»or>'  nueleua,  Uie  middle  [mrt  u  tli«  vtupu  nucleuii 
frviit  part  of  ihe  Kl<B*u-[>hnr_vni;eat  nufleuA. 

Ail  tbr  litim,  boH«ver,  uf  tlu-  fiuis  of  ilu-iae  tbreo  oerves  do  nut  takeorigio 
tran  the  noc-leus  in  ({uettion ;  *i>iiii^  »( the  fitiiva  iitart  in  a  diffcivDt  irnr.  In 
M«tiMl»  of  tlie  bulb  above  the  decur^alion  of  the.  |iyranii(I  a  patch  of  ffrav 
(ukIUt  i*  MCfi  lying  iii  the  lali-ral  part  uf  thi--  n-tii'iilur  fonnatum  (.Fig.  If^i. 
\.  III. >,  about  niidnay  bKvii-n  ventral  aod  ilunuil  mirface)^  What  i»  tbw 
diMlra**!  by  Kctionii  'n  a  cditnin  of  ]|Tay  matur,  ihi^  "  nuckuN  anibiguns" 
(Fig.  \'JZ,  ii'i.),*In1cliiiigHhoiil  a*  farlurwanl  anil  backward  at  ihr  combined 
MVtwtry-vago-glomo-phnryngvnl  iincli-un,  bnt  pUcM)  (ll<inctlv  more  ven- 
tral ty  and  KinMjwhat  more  rnlcrallr.  (In' l-'ig.  1!:f3,  it  anil  tfie  combined 
iiiicleu»  lira  rrprrm-utcd  •m  diHcrcnt  ■Jd»  of  the  diamiiR  to  iit-oid  confusion 
thrmiirb  th«  overlapping  of  thr  shading  )  From  it  nbn*  curve  round  (Fiic- 
irtT,  X.iD.).  tojoiD  the accnsory  vago-glos8o-pharyiigv«I  roole,  but  e»pecialR' 
tfae  vagin  naU.  It  mnv  therefore  Tie  consider^  u  a  wcond  nucleus  of  the 
fwui  (ftod  powblr  of  t)io  other)  roole. 

But  tliwe  i«  yet  n  third  MuroeofsomeDf  the  fibres  of  the  nerves  of  whidi 
we  are  speaking.  In  eections  through  the  bulb  there  may  be  seen  jus)  ven- 
tral to  and  a  lillle  lateral  to  the  combined  nucteurt  t  Fig.  llil,  4,  5.  l>,  1\.  a.), 
ihe  circular  feclion  of  a  longitudinal  bundle  of  tibres,  In  the  binder  sectioiu 
I  Fig.  187,  4)  the  bundle  in  a  very  ihin  one,  and  -ilill  fiinlier  back  it  is  lost  to 
viaw,  tbough  there  are  reasons  for  thinking  tlini  dome  of  the  flbree  are  con- 
dniisd  back  into  the  cervical  cord,  as  far  as  tlie  orlgiu  uf  Ihe  fourth  cervical 
tMrre  or  even  beyond :  in  the  more  forward  sections  ( KIg.  1^7,  6  mid  6),  ii 
iuu'ama  in  diameter  and  may  be  traced  forward  U>  tliu  rmiil  end  of  thccom- 
bilMd  oucleiu  into  which  il  metres.  It  id  a  buudic  of  lilin^a  whicJi  starting 
tuccMHvely  in  the  laleral  ^ray  matter  of  th«  cervical  cord  unci  higher  up  in 
the  rvticular  Kirmation  of  thv  bulb,  run  longitudinally  forward :  tbe  bundle 
ai  fint  iocrcaan  in  sixc  by  the  luhlition  of  fresh  fibres  at  each  step ;  but  fur- 
ther forward  the  fihroi  lc«vo  the  bundle  to  pass  into  the  root»  of  the  nerves 
of  wbicb  we  arc  Kpenking.n'prciBllyof  tbo  glo»o-phnryngenl,and  the  bundle 
evcDtaaUy  ends  in  front  by  pauing  into  the  gl(M«o-]>haTyng«al  roots.  Tbe 
graf  nwUer  from  which  tbvec  fibres  take  orij^n  do«s  not  form  a  defined  com- 
pact area,  is  not  llrerefore  ii  nucleus  in  the  sense  in  wbicb  we  are  now  using 
tbe  term,  but  is  dilfiised  among  tltc  rest  of  the  gray  matter  along  a  consider- 
tble  length.  The  Hbm  are  nevertheless  6bres  of  n<?irve  mots,  and  the  bundle 
is  called  l\w  ateetuliHy  roirfof  (he  ghMW>-|AarTiij^>al.  (belerm  nsoending  being 
used  UDce  it  is  customary  to  tracv  such  ttructun^  from  below  upward,  that 
it  fton  behind  fbrwmrd:  though  »in<.'e  the  Hbrc4  in  question  are  probably  af- 
fhnalflbre*  carrying  impulses  backward  from  tlie  nerves  t<i  the  gray  matter, 
" d<actn<l!ng "  would  he  the  more  appropriate  woid.  The  bundle  has  also 
Iwm  called  thtfiurieiiliu  /ntHaritu;  and, since  ila  [xisitinn  has  been  supposed 
|o  corrapond  to  iliat  uf  the  area  marked  out  ex  peri  m«u  tally  as  the  respira- 
torr  centre  ($  362),  it  ha*  be«-ii  spoken  of  as  the  renpirrtimy  hunHit. 

'hM-  root*  of  ihttc  throe  nerves  then,  the  bulltar  accattory,  the  vagus,  aiid 
lh«>  gliNvo pharyngeal,  all  learing  tbe  surface  of  the  brain  iiluiig  tlte  linu 
betwwii  the  olive  and  the  reatltbrm  body,  and  all  do  far  nltku  that  it  is 
imiia«b)c  upon  mere  ionnvction  to  say  ntierc  in  the  wrics  the  fibrea  of  tlie 
middle  nerve,  thr  vagtm,  lie^in  and  end,  spring  from  three  sotirce*,  the  com* 
bine)  nnclvos,  the  nudt'UH  ainbiguu.i,  and  iW  ascending  nxit. 

$  619.  Thr  fiifhih  or  auditory  nenv.  This  nerve  iriflerv  from  the  Other 
ner^'e#  which  we  are  now  conndcring  in  boiog  n  nerve  of  sncdal  MUse;  ita 
arnugements  atr  complicated.  In  a  view  of  the  bote  of  the  1>rain  (Fig.  146. 
C),  tbe  nerve  is  seen  to  leave  the  surface  of  the  hrain  from  the  ventral  sur- 


752 


Am'of  tlic  Ion'  pun  of  the  n^iif'nrni  Ixxlr  lit  tliu  hiiiil  nmi^in  of  the  panii 
two  nniidfl  (ir  nxits.  uiw  ^>f  whkh  wimU  round  liit-  rcelifnnn  liodj  mm  t* 
Tviti-h  \t»  doml  Hirriicc  whilo  the  »ther  nnpi-ur'  fi  eink  iitln  the  MMtUHcdT 
the  hull)  to  lh«  median  sid«  of  iIm-  rMtirorm  hocly  ;  mod  in  n  tnosnK  Mo- 
tion of  the  bulb  {Vig.  lt*tt)  just  behind  tli«  imns  ihr  two  nxrta  mar  hcMCo 
embracing  th«  rcstiforni  bocfy,  one  pominE  on  it«  dorsal  and  tbe  otber  co  ill 
vcnlrnl  side.  The  former  is  called  ihe  aormtl  root  ((''iK-  If^),  ornnKtian 
tfae  lal«ral  root,  or  since  it  readies  badi  or  tow«r  down  than  ibc  tilliff.  the 
poMerior  or  inferior  root :  tl»e  latter  is  called  lli«  renlrai  root  (Fi^-  H^'f,  or 
someciiues  the  median  rw>t,  or  aince  it  reaches  further  forward  or  liigtuir  op 
than  the  other,  the  anterior  or  superior  hmjC.  When  we  cmue  tn  »tu'ly  thr 
ear  ve  aJmil  iiati  thai  oa«  diviaioili  of  lh«  audiiory  nerve  in  iliitribuud  to  tbt 
eodil«a  alone,  and  isoalled  the  nervus  i-uclilcarid,  the  retiloflbo  ntrrv  hcin;- 
diotrihuteil  to  the  utricle,  Mccule  and  aeniidrcular  cauain  an  tlM>  nrrvm  v»- 
iJlHilaris.  As  we  Hhall  aee.  there  are  mauiid  fur  thiiikiu);  that  thi;  vn>nhti>tr 
nerve  <uirri«i  up  to  the  brain  fVnm  the  Minioircular  caiiab  impul- 
than  thorn:  or  h4;Hid4»  th<w<  whtoh  give  rise  to  aensatiouit  of  sound.  '  < 
lh«  oochlcar  nerve  anjieimi  to  ht;  exclutiiraly  conoeniei)  in  bMuine ;  nii'i  m 
tuune  Btructural  de4aiU  ihtvn  two  divi*iotia  of  ttie  auditorj  nerve  difler  (nm 
ABch  other.  Hence  it  is  im|M>rtHnt  to  note  tluit  according  to  oarcful  ini-r>U 
^tion*  the  cochlear  nvrve  i*  ihr  cnniiuiiailoaof  iheiloMU  root  and  ihr  vn 
uhulor  nerve  the  c>»itiiiiiatioo  of  the  ventral  root.  Witli  thu>e  mots  of  tbt 
auditor)'  nerve  projier  iiIki  iwii»  little  in  front  of  tki:  ventrml  root,  the  #>mU 
nerve  callwi  the  fmrtin  inlirrmftialf  Wri^terfi,  whieb  goce  to  join  the  Ruial 
i»erve. 

Tli«  iiuditory  nucleus,  lu  a  wbok.  is  a  hn«d  iiias]!,  having  in  tnmveni 
BeclioQS  of  the  bulb  a  fan>cwhat  (nanguliir  form,  lyiu);  in  the  lateral  piirt> 
of  the  floor  of  the  fourth  ventricle,  rvnchitis  in  front  aomewhut  l*ey»"ii  t^' 
level  of  the  slriie  seu)>tiua\  and  overlapping  Mi ind  the  front  paru  of  tlir  rni- 
eleiis  ambigiuDB  and  the  combined  acoeSBory-vago-glo«BO-pharyuKe«l  aa<itut, 
it  extends  iaieniUy  some  distance  outside  ihe  former  nucleus. 

The  nucleus,  liowever.  consists  of  two  distinct  parts,  a  mcufiiM  or  laav 
mieieiit  [,I'"'K-  l^''-  VIU.,  «!.),  characleriied  by  the  presence  of  iraall  »«lk 
and  K  lateral  or  outer  nucleus  (.Fig.  VXi.  VIII..  /.).  tlie  cells  of  whidi  Ut 
much  larger,  aofiie  of  ibeoi  being  ^-ery  large.  The  lateral  nucK-^is  t*  yln-t<\ 
aomewhal  deeper  than,  ventral  to.  the  median  nucleus:  it  alM>  i^xh-iids  lunhn 
forward  (Flip.  188  and  H'J.  Vlll..,i), so  that  tlie  front  end  of  ihe  nboli- 
nucleua  b  furnished  l>y  the  lateral  nucleus  alone  which  at  its  front  eml  <«vU' 
p(ea  a  more  durwl  |)OHilii>ii  than  at  He.  hiiul  end. 

Moreover  tlit*  audilorv  uucleuH  thus  ptaual  in  the  floor  of  ibr  founb 
veutricte  is  iH)t  the  whole  of  the  nucleua  of  the  aiidiliiry  iterve.  At  i^r 
coaver^nce  of  the  dorsal  and  ventral  roots  on  the  ventral  Kurlitir  of  l^r 
reMiform  IxkIv  it>  placed  a  group  of  ivlb,  forming  it  Nwvlliiig  which  In  i» 
genermi  apuearanoe  and  in  the  cliarnutcni  of  it.-)  criln  in  nut  unlike  i  pa- 
glion  on  the  poaterior  roiit  of  a  iipinnl  iiervo.  Thii  in  calhv)  the  ntwmf} 
nucfetM. 

When  we  trai<e  lfa«  fibreii  of  the  nerve  centntlwanl  into  lJi«  bimin,  nr  (in^ 
that  a  lar|;e  numln'r  el  leaat  ot  lli«  fibres  of  tlie  dorwil  r<Mit,  cuvhim  Utrvr 
(Kig.  188).  cud.  iicoinling  to  rkhiI  obaorven'.  in  Iht-  cetle  of  the  oecaMitj 
nucwuN,  or  in  iH-rvr  cell" lying  dorail  to  the  accvsMiry  uuvleu!  iitid  e»pcdtl? 
in  a  gmup  »f  idln  giving  Hue  to  (he  luttrrt-alum  ••ru/dicnm.  which,  xiuall  it 
man,  a  coitSj>i<'«»iix  in  Mime  KiiinmU.  Ilencc  ihv  farllu-r  piirl  of  ttisXltt*! 
root,  as  It  U'lndM  rouiKl  ihc  IiiK^rnl  iind  dorvnl  ^urTacu  of  tlie  rwlifonu  haif, 
coiuiiiUi  lar^gely,  if  not  wliolly,  of  6bre8  which  are  ilcrived  nut  diiwily  At* 
the  trunk  of  tlie  iverve,  hut  indirectly  ihrtMigh  ihe  relay  nf  the  aciawr? 


■MHW orHTwitT  i'ellrt.  Kviii;)iiii)c  tbi-  ilnrul  surfaoe cif  (he  ratUbrm  bodyi 
lliCM  Abrvt  u|i[ir«r  on  tliu  tlunr  or  Uie  futirtli  reuUricIf!  m  tbe  ttrim  antluet 
I  Pig.  I^ti,  «lr.  t,  Hiiil  vad  pnnly  in  tiiir  iii«^)t»ii  uucleuv,  |iurtly  in  otbrr  rcgiotw 
•li  (br  hiilb.     Thi*  vsiu-t  iJtU'rniiiiiilioii,  )ll>n(.'Vl^^,  ol'  ibv  vniliiifjs  nf  (iiU  root 


I'  It..  lUl 


4M< 


VII  q 


./ 


le^Jtv*.** 


>«(i 


I 
I 


IWUCOH  Tim  iitMMr  fiar  or  nii  rm'iiTH  VumMij'.  'SutgaMimvx.) 
TMkvn  In  ibc  Uiic  III.  Hc-  lU 
ftMMninU>Wnbi*irulmn»niv))-.  fr, />..  IbP  niiMnlaliil  mnlnll  liBuvKn  llbiB  M  (he  |uiM. 
TktilM'lMl  |iM(»rilM  |iin*'i>'.  rilndtoiCcBiiajaMlw mlnclalwIUi  Iho itecper  Itaintene nbmi. 
''..U*  ni)r«.  7)>..  Iliu  intciltHa:  c  X.,  Uw  i«iUII>ni  bodf  orUArlw  i«diing;»<tf  ihv  oMvWItiUB, 
•ul ••HI* iiUhurlir  i K  ^.. lk« •U|«rlui  |i*ilunr1r«->riliDMrabutl«in  :  r.,  rapbi;;  i.  a.mtwriacoUw. 
I*  il.cMfaiil*Miil(iinafth*»Rlwllnni.  ^.a^ihc  nucloui  of  Ibe  (aaf :  a.  |i^  (nberchoflRoIuida  ; 
f.  X,.*MHau  thjaimti  nlciia  in  ih*  TennUMi|«rlor  of  ilw  (anbrilnm  :  l.  Iniiulhi  fttna  ilwi>llr*U 
ItottMlnlar  iiucln*:  Vlll..iii>(4fbUiatMHllt«yDm«.ltirmivl-i>imill>nlMraui.  pniMciMnK 
AOB  Vlll  ,i.  Uic(iwii[iui-iribv  liteial BOiIlkirr  Dotlcai :  Vtt.  n .  Uw  duoIbiu  «r (ba  MitMllilor 
(MUl  iivm  ,  VI,.  lb*  MMkaiaf  tbo  ititli  oerw  ;  VII  u.,  Illina  of  lb*  wrvuih  nnnv  cut  VRMa* 
ito|r  ta«i-'"<"<-llbr  audgDn^lhttlilbbvlbivlHuliMf  (mm  Uw|nw«*  VII,^  Mb.  Utr  knirth  reb' 
nWk.  b«l«  rooM  in  !•)  Ihc  rvrateltam  :  Ihv  iluutliiK  nt  ih*  CHirnl  fta^  M«IMf  ilniD«>tUl*>r  <«r- 
tiMMatluf  IkcivntrlrV  [m.  »<r  ib«  Mktuf  iIiutJipKy,  •imlRid. 

>•  «  niMter  uf  coDHideroble  dtllioully :  »ura«  obttrvtn  rv^rd  tlie  aceOKwy 
Dudout  Ha  l»(>iu«li<f^iuf,  nut  witb  tlit:  G«B«riwi  and  iriih  ihe  tpiual  ]||^nglin, 
but  with  tbe  (itlitT.  im«,  vrantal  nucid ;  anil  lu  uiy  cum  we  must  probiibly 
coDuder  thv  luwliwu  iliviiiion  ul'  llii-  auditory  nucieui,  not  u  a  nucleii*  io 
tbe  wtBM!  ill  wbich  we  aiv  now  iisiiiy  il,  liul  rather  u  m  MOOBdAiy  oonnectioii 
within  tbe  )>ulb. 

VVIh-u  <m  tnuv  tlio  ventral  n>oi,  vealibuUr  B*rv«  (Fig.  189),  inward,  w* 

-IB 


7ol 


TRE    BRAtir. 


lind  ibnt  RUikiiii;.  acordEog  to  inoel  nWrvere.  nu  nmueclldos  bI  dII  nith 
llie  aceeworr  nucleus,  it  pggaes  (Fi;;.  I'^l*.  viii.)  lo  ihe  intdUn  Nr)«  of  ih* 
rcMifbnn  bmh-.  belween  it  and  tlie  asoendin;;  root  of  t)i«  fifth  u«rt*,  sod  w 
resobee  Die  lateral  division  ot'  llie  nucleus,  in  the  Inrj^e  i-elltt  of  wfairb  niaM 
at  least  of  its  Bbn»  arv  eaid  to  eud,  and  which,  ilierefnrv.  niav  be  regarded 
ax  the  nucleus  of  the  ventral  roiU.  Un  this  (loint,  hou'ever.  all  autl»ur»  an 
not  neretil.  Tlte  lateral  auditory  nucleuM,  with  the  Bbre»  proc«ei]iu(:  to  and 
tn>m  It,  lying  tut  they  d<i  lo  the  median  or  inner  tit<b  of  the  niitifonn  biMiy 
|>roi>cr,  are  aumeiiineti  spolcen  of  ax  the  iniMlinn  or  inner  diviiiiin  of  tbr 
irslifDrm  hmly ;  and  fnmi  the  nijclciiii  a.  consideriilite  numhcr  cif  fibnv  \imm 
lip  with  Ihv  rextifiirm  hiHly  into  Um  cerebellum  n*  a  conlinuatiou  of  tliia 
'*  median  division  of  llir  rrstUorm  Iwdy,"  Some  author*  maintain  thai  thiM 
8bres  aro  continued  •imiglu  on  frtmi  the  nerve  to  tht- •.vrclwlliim:  but  thr 
more  r..-c«nt  invrntintiom  M«ni  to  show  that  ihcy  nil  make  conon-tions  with 
tlie  nervocelU  nf  the  lateral  niicIruK  oti  their  way.  TheBC  fibres  oon'litute 
B  connection  botwc>cn  the  auditory 'vt^libultir)  iien-e  and  the  ccrubelluai. 
the  phyeiolugical  *igTiilicKnce  of  which  we 'hall  f«e  Inter  on;  we  inny.  per- 
haps, coDipare  it  to  the  connection  between  the  poeterior  mots  of  the  §pinal 
nerves  and  the  cerebellum  through  (thfl  vewcutar  cylioder  andj  the  cere- 
bellar tract. 

Tlie  other  central  connectiuna  of  the  tateral  nueletts  are.  like  tboae  of  the 
■cceasory  and  of  the  median  nucleus,  complicated  aitd  ohHciirv.  Hut  we 
may  call  atteutiuu  to  a  tet  of  fibres  which,  uartioK  apnarentlv  in  the  nc<«i- 
Rory  nucleuK,  run  directly  Iranaverae  in  tlte  ventral  nseion  (if  the  tegnientuai 
}ntt  doiwil  bi  the  iranvenc  Uhreti  of  the  [mott,  furmmg  what  u  allied  the 
lr»i.'tiiim  (Fig.  189.  Tp.). 

Lottly,  we  may  add  that  the  fibrea  of  the  peculiar  p«rti<t  inlermrdia  appear 
to  lake  origin  from  the  iico«Mory  nucltiH. 

5  680.  Thf  ttvrttA  or  fitiaf  ngfoe.  The  nucleus  (Fig.  W-i.  VII..  and 
Fig*.  IJSS.  1W».  VII ,  n.),  of  this  nerve  (it  being  borne  in  mind  that  the 
mi>tor  libres  for  the  orbital  region  (the  corbicular  muscle,  etc.).  though  they 
run  in  the  trunk  of  tbb  nerve,  really  belong  to  tli«  thini  nerve  and  lake 
»rit;ii)  fri)iu  the  hind  part  of  the  nucleus  of  the  third  ni-rvc)  narroirer  Ea 
front  ihnn  hehinil.  reaches  from  the  level  of  the  btri^t  acUHlicie  toroe  dlatancc 
int'i  the  regiuii  of  the  pons,  and  occu|nc9  in  the  midst  of  the  reticular  forma- 
tii>»,  a  little  doraal  of  the  patch  of  gray  mutter  culled  tlie  upper  olive,  a 
pnfilion  cinrres[i'tndiug  cIo«ely  to  that  of  the  nudetin  amhi)^ii«.  Tlie  cell* 
of  the  nucleiin  are  large,  and  ixBtiecu  well-marked  axii^cylintlcr  pmcettr*, 
which  are  gathered  up  at  the  ilnrsal  nurfara  of  the  niicl»iis  to  form  the  root. 
This,  rising  up  diirenlly.  d<.-»cribe«  a  loop  (Fig.  Iftfl,  VII.,  y.)  n>und  the 
nucleati  of  tlie  nixth  or  abdunnit  nerve,  running  forwmrd  fur  tame  little  dis- 
tance dumi  to  that  nucleuit,  and  then  descends  again  vcnirally.  lousing  to 
Ibc  lau-ral  eiile  of  it^  own  niidfUi',  between  it  mid  the  ascending  nwt  of  the 
tifth  ( In.) ;  it  thus  gains  ilir  niirface  of  the  brain  at  the  hinder  margin  of 
the  |H>iis.  lateral  to  the  uhdurens.  ophite  the  front  end  nf  tl>e  groove  Ite- 
twei-n  the  olivarv  hiKly  and  the  resliform  body.  As  ii  thus  encircles  the 
nucleus  of  the  nliducens,  it  looks  as  if  it  were  receiving  fibres  from  tliai 
body  ;  but  the  evidenoe  gow  lo  show  that  thmo  fibres  limply  pus  through 
the  nucletts,  and  do  aot  lue  urigin  from  any  of  its  cells. 

$  621.  The  tirtliorabtiueeiu  tirree.  This  nerve  starts  from  n compact  oval 
nucleus  (Fig- 193,  VI.).  lying  at  the  level  of  tlie  hinder  jiart  of  th»  pun*. 
and  therefore  of  the  front  pert  of  the  fourth  ventricle,  in  the  oentral  gray 
matter  of  the  floor  >if  the  ventricle,  or  rather  juet  between  it  and  the  reticalor 
formation,  a  little  on  one  aide  of  the  median  line  (Fig.  181),  VI.).  A  flight 
~  tlic  llnor  uf  the  fourth  ventricle,  emineuiia  tcroa,  mark*  its  posi- 


THE   QRAV    MATTKK. 


TS8 


I  Fin-  11)3.  «>.(.)■  Til*  nucleus  «oni«iiw  fairly  lar^e  nervo-oolU,  with 
„nct  axU-cyliiiJer  proceMM.  TheM  are  gathered  at  the  nieiliati  tUh  of 
nurli-uN  to' form  the  tliin  ruot.  whi<.-h  piL»ii))c  ventrally  aii<t  litlvriilly.  at 
■UDT  little  ilisiaui-e  ffoin  tiie  nioilinii  niphc,  llir»U){h  ihe  retictilar  forniaiion. 
niiM  baiilcKnnl  above  the  [lyrnitii'lil  l)iindl«»  of  the  pou*,  and  tiiinllv  roniM 
to  tkp  BurrnM.'  at  thd  bliiikT  edje  of  tlic  poiu,  upposlto  the  front  em)  of  ihu 
pynuiil  (Fig.  I8B,  C). 

nu.  M. 


via. 


*• 


>th 


V* 


Va 


THiwiHiii  ni(  ivm  «T  na  Xttt  or  tiik  rimi  Naarc    (HiiRaauKina  | 
lnilicnn>'  l)£  ric.  tn. 

C.  UnltKtImttntUlona  lodr  .  K  K.  •aiMrtflriwliiM-iaurilwouBIitlluiD.  f.  dl.  niBtlsn-.  f.  I. 
Uln«l  MM,  r.  R..  MsmwiUl  nilrular  *L«mitli>M.  %i.  e„  raptaOcM  imimnaabi*!  uTtlui  poai^ 
l_  iDilenui  k«NCtni4l«Ml  bundla;  V.  *..  auiortai  Trriiili  iKUQcmt  of  lliiw  Mte  aiv  ihOWM.  one 
twtna  dslarb^ :  bcoinai  ihria  uic  iiibrtfriiinf  tiilel  Ul>l  o^rn  r>r  ibr  •Mikn  u*  mn) :  VW^  nlic 
nl  VliBiiMU  «  itMerlur  nlum^  i..  niplit:  ly..  i-rnniliUI  alina;  tr.  P.  aiar  —Mai  o4  lbs  |»ni 
*.a,«i|Mta«atlTaL  t,  itewil  on  am  Irft  •■■I*  liidMalot  Uw  |i«iltloii  of*  taodle  of  lonftiwliiul 
atom  vkUli  rutr  l» UM«4  tomfd  tiiu> ite •uMhaluBlo  *a(k«wL  V.  w.,  aout  imeteai  V  •..•« 
wry  nadMH',  •*>  V,.  notaoriacnnhiwcvc.  Iih.  iMnli  raiMck :  ilwdliutefnuiMlin)  nuiwi 
oBlual  M  IB  nc-  ">■ 


$  628.  TheMh  or  rri^tuniiia/  nenw.  Tbia  narro,  aa  it  oooMa  to  tlw  aurfaoe 
oo  Uw  vanUvT  aspect  of  th«  poii*  (Fig.  186,  C),  near  tho  IVoqi  odgv,  at 
aona  diauoee  from  the  nMliaii  litm.  cuniuta  of  two  purta,  a  anuller  motor 
not  UmI  a  lw!K«r  Mdtaorv  ruot,  the  Ull«r  boaring  Ihe  lar);^  [^ii);lio<i  of 
Gaawr;  and  tfaa  orlglu  of  (he  uerv«  U  in  ntan^  way«  cnrnplex.  Uijih  roou 
nutj  bo  traced  la  ao  »hlti)(M  diraction  (Fig.  100,  V.^  innanJ  and  toward  the 
doiMl  urfaoa.  through  the  |Miu  to  the  raiicular  tornuliou  beosaih  the  door 


73ft 


THS  VBATN. 


of  the  froDt  part  of  ihr  foimli  vcntrk-le,  tlie  •maltcr  mouir  root  ukiii^  u|<  a 
po«iitioii  median  to  tbe  larger  tfcnsory  root. 

Here  the  motor  root  conice  into  cunnertion  with  n  ixillwiion  nf  iwrtiMxJb 
(Fi|p».  1{I3  and  190.  V.  m.),  whidi  may  ho  rmrdrd  ns  iu  nudrut;  liut  (bit 
is  not  tlie  wliole  nucleus  of  tbe  motor  root.  From  tliv  level  of  tbo  oaiitm 
there  atreicbes  forward  as  far  as  tbe  level  of  Ih?  ■n(i*rior  cwrpon  wwki- 
gemtiitt  u  hiiudle  of  lonicitudinal  libres  wbicb.  »inoe  it  is  usually  tnwM  ftoni 
the  front  biickwartl  iiutil  it  nasepa  iolo  the  root  of  the  Derve.  b  fpnkni  of 
H  Ihf  dr"-rniHn<j  mot  of  tb*  tifth  nerve. 

Tbi»  di'^ci'iidinjit  (xMit  bfj^ns  ua  a  few  scattered  bundles  of  filirw  u  ik 
Icvi'I  of  llii-  anterior  cnrji'ira  i(uadrigemiua.  in  tbe  perifibcrul  lattnl  pui 
of  the  ci-iiti'Hl  gmy  miilli-r  ttiirroiiDainjc  tbe  a(|iiei|iiet,  dnrwil,  and  bunl 
(Fig.   19'i.  V,  (f  1.  io   \\\c   nucleus  of  the  third   nerve  (Fi((.    19'.?.   IN,,*, 


From  Ibcncv  the  fibri-s   |>ims  liarkuai-d,  aujcmentiDfc  in  number,  am] 

'        '   "      iMeralu 

increMinf  b 


form  n  compact  bundle,  fcmiliiniir  in  Ininxverwe  lectioti,  Ifini;  Interal  totb 
fourth  nerve  na  this  i»  rising  dontatly  I  Fig.  19!,  V.  d.) ;  atilT  ii 


Fk.  191. 


■»:■ 
■^c?- 


.^^^ii&SS' 


Tiinuihii  n«  F'oNB.pARior  Tiiii  l<am,  (MtRKDfarMi.i  In  ilMlliiPtO.  Pif.  iim. 
IV.  pTTBDiMal  llhmt  f-  ''■  Obrw  Ihim  tlM  Itaailil  ohms:  X  I*,  nipcffiir  |vil>iiic1e  .if  Uw  nip 
IVilumi  rm.  median  pratian.  f  lalenl  pcinloa  «(  tkc  lllrt  : '-  piwwrfor  bmciliirUiinl  >iwP>  , 
P.  C  </■  lawtior  ooiiiuis  iiaNlrtNanliw ;  is  fibiw  wlilrb  lnwoiw  dplwhri  ftum  lh0  Blltt.  niid  riiRlH' 
'omrd  tiitin  iiht  tnrwnmali  jan  ol  ilm  pm  nf  ilw  nn»  i.  r.  tooai  acnilc'w .  •■■  P.  Q.  iiut*>in  «t 
ItiopoMUlot  CDTp(iai|Mdi1SEinlDB-ihvcidillB*Uui«4CMniiIiitni;  IV.  biiii-lloor  Ibr  tourtli  imvt 
dMiMMttnir.  n'.  ■.  lunuclMiii  V.'i,  ricH«aillni  iwH  or  itM  «nhi»n»;  ^v,  ihr  oiiiwObri  :  i-.f  im 
rnSon  of  n-ii(nl  cnjr  tuaim. 

number  Jn  thtir  CKirie  tnckwanl,  (her  (^dually  aasume  ft  more  ventral 
poeitioD  ii>  ibo  ttaunluot  oprn*  into  tlie  fourth  ventricle.  All  mlong  iit 
I'oune  thii  (ItacruniDg  root  ha«  altacbed  to  it  lari^e  (70  ••  or  more  in  duuu- 
eter),  spuie  apberMdal  nerrc-celle  of  etrikinr  appearance;  these,  Uomtrtti, 
•eonloo  few  to  givu  origin  to  nt  least  all  tne  fibres,  nitd  there  mn>  wqm 
nsMOS  for  conuccliDg  this  root  with  the  collection  of  f^ray  matter  itdM 
"locw  cwnileuE."     (Fig.  191.  (.  *■) 

We  mar  probably  regard  this  deac^-nding  root  aa  bdoneiug  to  tbo  niotoi 
division  of  the  nerve;  but  it  ia  Mated  thai  nianv  of  the  nhree  of  tlib  ru»l 


TUB  ORAV    MATTBB. 

inlo  ths  motorj  Tvnt,  4-v(iiititiilly  flniliiig  their  wi\}-,  MCOrdInx  to  wiiie 
ohMrvcn>.  into  iht  oplilhftlinic  kraiich, 

Tlw  »ri«ory  rool  mar  be  timiUrly  irjiciil  into  it  uiiclciiii,  the  sonitory 

DUclciM  I  Fi^  lO.^  aifl  iW,  V.  t.)  lying  laU-Titl  Ui  [bo  motor  iiucli^u*,  niiil 

CoaiMoU*)  with  this  U  ihv  slrikiii);  tract  ol'  Hbre*.  to  which  nlrniiilv  wt-  hnve 

'  lOftcqtwittlTnltiKied,  and  wliich  u  ralloiJ  the 'Meriii/ifitf  roof  of  thu  I^IVh  nerve. 

This  m»o.-n<)iii(,'  root  be|;iiiB  as  n  buDcllc  or  bittiHlu  of  few  fibres  which 
■ar  be  tnicctl  Iwckwan)  as  far  as  at  tcadt  th«  level  of  tlie  Mcoiid  cervical 
aervt,  and  it  cooa  oouapjouous  iu  Irangveme  aections  (Fig-  147  «t  t^.,  V.  a.) 
m  ftMmiliiuiir  patch  or  white  luatler  furioia^  a  sort  of  cap  on  the  oulsidft  of 
the  Bwollcii  caput  of  the  posteiiur  Iiorii,  between  thia  etnicturc  and  the  lon- 
gitudinal fibres  which  are  beiicinnins  to  form  the  rcetifonn  body  on  the 


Fia.tSt. 


\ 


TiUHiiva  ma  Can  am  AiTKiiinB  ciiM«vi«t  iji'uiwamD't.  (SniSRaHnew.) 
OBv-hniroiilr  Ixbotiii.kiitbsUuall*.  1^.  IM, 
^  UN  pfmKtdal  innlcm  nr  Ibc  |m.  »  Ihv  nclu'i  »<  111*  t«oc«u|4Hl  bf  libra  (rnoi  ibeffDiiUl 
fatitmt  aCihttvntx.  fr  o.  the  kkiuo uoea|4cil  bj  nlma mmluit (rem  itoocclplial  lotUonoT  iba 
MHU ;  r  Mm*  cKunlna  trim  Uit  lUHt  -.  'tr.  tba  opuc  im« ;  IF.  tbe  IIIlM,  I.  U»  lu«m  pMlMi.  m.  tb* 
i<1lsa  lunti :  I.  Uw  iiatcrto*  lungHiidliiBl  btiadic :  it>  a.  (be  bmolilQtn  nf  iiic  uiierlar  CDrpoi 
i|a»ili1a—lliiiw  ;  t.  lllmi  (ram  Ite  imlcrlur  aiinaiMU*  of  Ibe  cvNtmiu .  r.  n)0>*  x  ^  •hWuhiIa 
■Itn  ^  jr.  a.  nd  (iiifImu  ;  C  p,  t  Lilmil.  kih)  C  y.  <l  nwdbia  wrpiu  (nilculMam .  fn.  pulTlnu  of 
iifrili  Ihalaniu:  A.  V  ■-  iiu«li>ui'>r  Kn;  niallertrf  knlivtur  Coriiiu  ■)■*'■  ilStBiluuin :  111.  n,  Burloiu 
ui  III.  HUM  acrra:  III.'  luoiMi  rmiii  ilisdifHiI  lanotlll.  ■..tb«  nocItuiorilM  thin)  nan*.  wUcll 
era*  lb*  acdUa  Una  la  miBivr  witb  mMleli  ilerlrttl  Ihm  Uie  nurlcia  of  Ibe  opialie  ilda :  i.  ml 
nqartdBl  lar«  oT  abfa  of  lb*  ■nLmri'.  quail.:  d.*i.4ee|t  layers  Ji%^'aa&atA  tumniiidvl  by 
«»bnl  fnr  awnu. 

mrftce.  pMuog  upward,  and  oonllnuBlIy  nugownling  in  bulk,  the  root 
elingi,  M  it  were,  to  \Xw  g^laiinouN  mbstnaco  of  tbe  canut  of  the  posterior 
horn,  and  nnk*  nilh  it  inwnrilly  iind  vcDtmliy  as  tliis  becoinca  eovered  up 
fint  by  the  nstiforni  timly  mid  Kub«o|ii(-(>(ly  br  the  iauiiag  trunk  nf  tbe 

EMt  nighth  or  auditory  'ocrTc  (Pig».  19^,  l(5d>.  Panins  still  fi>rt<ard, 
jrond  the  dtMpiN-nriDg  freUtinous  xubatance,  tbe  root,  ■ttll  growiuj;  larger 
ium)  divid<id  into  wwral  distinct  biindle».  runs  into  the  reticular  funnation  of 
tlie  {Hitii  aiKl,  It-aching  (he  level  of  the  sensory  uudetis,  suddenly  bend* 
rouod  nod  joini>  the  vrnsory  root. 

Tbi*  iMoeDdiiitt  root  dillors  from  the  deK-endinj;  root  in  not  having  ooii- 
•picuouvly  ntiached  tn  it  any  collection  of  Derve-cvlla:  iii  thia  nvpool  it 
rmecDbles  the  nscctitling  root  of  the  gtoeso-pharyiij^iil.  dihI  »e  tii«y  add  purl 


760 


THE   8RAIX. 


w*  ^lall  »ee  later  on,  ibit>  uerve  b  now  exdu«iv«l>'  efthmit,  wluiivvrr  U  nii 
have  been  iu  imire  jiriiMitive  beingtt.     W«!<linll  alaoMie  lnr>>r  mi,  ihfti  im;>'>'' 
iliartiug  rr»in  llie4.-<!ret)nnii(if  <io«i<ii)e  pttm  to  ltieo<Tve<>f  ihruthor  >i<l-    i 
ii  to  Mty  d«Gtuwiis;  and  ihin  UbImo  tli«  auw  u-tth  th«  tiihor  rflV-mii  >>  <  -  > 
iicrvuH.     Tht  Sbrei  irhioh  appear  to  take  nrigin  frum  tlie  hrrvv-tvlU  <it  ;' 
niideui  do  not  crow  over  afur  emerging  frurii  tlM,-  iiucku",  but  kwp  t<-  ili> 
MUM  lida :  thore  U  no  dwtnnt  il^^iuwatinn  w  in  the  oiiM>  jui>t  notM  of  lir 
fittirth  norvo.    Thcr*-  an;,  Imwcvcr,  lilnv*  :Fig.  Ifl'i.  III.')  whicli  laaviag  tin 
uuL'liHi*  crmu  tbc  nKfliim  raphe  from  oih-  side  In  Hir  "thvr,  un<l  thetf  pcMibli 
are  iIkt  imths  for  the  <IccuMiilioii  of  ibc  imputare  :  hut  thf>r  may  ur  fibm 
paasinc  Irom  thv  crtiK  acrow  th«  raphe  to  the  iiiK'leos.     'this   iiervr  ku 
■peci«r  relations  irilh  the  optic  trad,  but  of  tlnete  nv  slinll  sfMult  wli«a  at 
OODC  to  deal  with  the  fuitcttotiJ^  of  tbe  nerv«s. 

$  82ft.  In  attempting  to  uixlen^lnnd  the  nal(ir«  and  relations  of  these  craoU 
nervee,  it  must  be  borne  iu  mind  that,  while  niorpbolofjical  studiea  lead  uilD 
beliere  that,  as  the  vertebrate  body  baa  been  developed  out  of  an  iiiTenebntk 
ancestry,  so  the  brain  of  tbe  vert«brat«  has  arisen  by  a  series  of  luodirmtiin 
from  Ine  n«rvouB  Btnicturea  placed  at  the  head  and  arouiut  tli4!  iiiuatli  uf  vi 
Invertebrate,  tbe  same  atudiee  teach  U6  that  auch  an  evuluiioo  liu  bMi 
a<N.-omp) talked  by  uiettiu  of  profound  changes.  We  haw.  for  innianre,  na«>ii 
to  thiitk  that  the  mouth  of  the  vertebrate  does  not  correspond  to  tha  mouih 
of  tbe  iiiverlebrale,  but  ii  a  new  sLructure,  wbi»c  aj>pearanoe  luu  been  acoooi- 
panted  by  a  conHblenible  dulocation  of  parts.  ^V«  niual  a«-oiirdinflT  expert 
ti>  fmil  tht!  iiidicali'>na  of  a  neKnienlal  urraii^-rovnl  grMtly  otwuml  iw  I^ 
one  haix)  by  traiixiMMittiin,  aiHt  iHt  tbe  otiwr  by  fu>ioD. 

The  twdnh  iir  hy|»i>|^lnMul  ucrvu  i*  one  vh<i*v  nalure  vritms  fairly  *impl*- 
It  ii  in  function  t-xchisiri'ly  iiu  rlfi^rvnt  iMirvr.  TIm-  Inrgi?  ■'•^llx,  with  iva- 
Kpicuous  axbicylindiT  proccwtTi,  which  characttrriM  ita  nui'leun.  an*  i-xacilj 
hko  tliiiw-  af  thf  anterior  hi)ni  of  tlw  spinal  aird  which  give  origin  to  ihr 
tibrvn  of  an  niitt-rior  root.  Tli^  niirlciM,  worsorcr,  in  its  iMisilion  curre^pco)^ 
tu  juiri  "f  iIm'  anterior  horn  of  tlie  uhiuiI  cord,  if  wv  laVe  intu  iM-ciRint  Ibr 
shilling  involved  iu  the  decumation  of  the  pyramids,  and  in  the  new  der»l(^ 
uiflnts  of  the  Itulb,  If  wo  conipara  Pig.  1^7  with  any  Eoction  of  the  oord,  at 
aan  that  tin-  liyjMigliMHil  nervo  cnrraipoods  to  an  anterior  ruot  of  ibe  t^ioal 
eon\.  but  that  the  fibtt»,  atlcr  leaving  lti«  celt*  from  whidi  they  lalie  llwir 
oritpii.  IraviTW  in  the  former  a  large  tract,  aud  iu  the  latter  case  a  unall  Uae* 
of  ti<aue.  Whether  tbs  whole  nerve  corresponds  to  the  tibrm  of  seventl  ftf * 
vanati-  fusMl  lugether,  or  to  tboae  of  one  eegmeoi  spread  out  longUurtinally,  a 
for  our  present  purpoaes  of  secondary  importaiice. 

Itecoipiizing  the  bypoglosaal  nerve  aa  toe  hooioloKiie  of  a  spinal  uiteri»r 
root,  we  may  go  on  to  claim  ilie  nuclei  of  the  third  and  fourth  uerviv  f 
similar  groups  of  cells  of  the  auterior  horn,  giving  rise  to  atiietijij  n**" 
Tlie  ]>oflilion  of  (he  nuclei,  the  character  of  tbe  cola,  the  fiincti<ia  <•(  thr 
fibres,  all  support  this  vieir.  The  caw  is  iwrha|ie  no4  ao  clear  as  tliai  V  il/r 
hypogloesal  uerve.  since  there  are  reasons  for  thinking  thai  thaw  ncrv«  \it*< 
unoergoDeiu  the  course  of  evolution  greater  changes  tlian  ban  the  hypn|leMl 
nerve;  still  llieM  reaMinii  do  not  opfmae  lite  abo\'e  cnrjunion. 

The  Ducteuv  iif  tbe  exclusively  motor  sixth  nerve  does  not  exactly  i^in*- 
sjMind  to  thua«  of  the  third  and  fourth  in  iMsitlon ;  but  wc  may  probsblr 
place  it  in  till-  »ame  serieti  with  iht-m.  Thus  vre  Itave  in  mics-vmiiun.  tbittkinl 
lourtJi.  sixth,  and  tweltlU  nerves,  with  their  respective  nui'li^i.  as  the  aalcr»r 
rootA  of  iicrveo  of  tlicir  sevdrs)  segments. 

Ill  the  filYh  ixrvc,  tbe  dislocmtion  and  fiuioD  spoken  of  above  has  latr>- 
duced  ditHi-ulticM.  The  motor  nucleus,  with  the  fibres  of  ibc  motor  rout  i" 
whi<Jj  it  givw  origin,  han  by  some  be*u  oiMuadorcd  n*  humohifivius  u  il't 


UV     MATTKB" 

rtxit  >kf  nil  onlinarv  spiiial  nerve,  the  fibres  of  which,  as  we 

iiilii  the  amy  miiiler  tviihaiit  IteUtg  obviouBlv  connecteil  with 

Iti  ilE  loner  ivart  nt  Icael  iL  cuiihIhis  orextreiuefv  fiue  flbret,  atid 

-•  vcrjr  much  like  n  aiiiliuuHiiuii   io  ihe  bulb  of  the  margiOBl 

-i>  t  *)  xonc  uf  ibe  f'piiiul  curd. 

3,   Thg/ourUi  or  froM/f'ii-  wtriy.    The  duc1«us  of  thin  uerve  (Fik.  1&3, 

•  ■  wliiiim  uf  aoiiiewhat  Inrce  luulliiHilar  cells  ou  riiuh  *iile  <>f  ihu 

lln«  lielow  lh«  ui(iieilLirt  (ti^'.  IIU,  IV.  ».),  renc-hiii);  t'roai  the  level 

inction  i>r  ilic  anierior  nnit  [lutiterior  corpora  quntirigeiuiDa  to  the 

(v«l  111"  the  iBltcr  body, 

I,  einrtiii)^  IWim  the  hiteral  niirfttct-  uf  the  nucleus,  <lo(«  not  titkc  lit 

airnl  iliroctiini,  but  sweep*  luierullv  and  dontiLllj:  in  the  outer  Inycrv 

ntral  gray  niiillcr  (Pig.  liH  I,  aDil  »>  curving  round  to  tlie  dorwl 

Itraclm  th«  valve  of  V'icuMcn*.  where  in  the  mctlinn  line  it  tteCU»aic« 

tfrlhtw  in  Ihe  ttilisliincc  of  the  valve ;  ttuch  a  (1ocii»»i!od  at  a  ilietitDci; 

>  nucleus  ofori^^n  is  except ioiinl  in  iho  cranial  uci\t».     I.c«viug  the 

see  of  the  brnin  in  ihe  valve,  il  takes  n  snperticiid  coureo  curving  ( Fig. 

it)  hilmlly  and  ventrally,  and  ninkc's  ils  appearance  in  a  ventral  view 

lie  brain  al  ll>e  frciQl  ed^c  of  the  pous,  on  ibc  Inlerol  edge  of  iIm.'  crus 

J  AM.  /'Ar  Ibird  or  oculx^nuUir  urrvf..  The  Ducleua  of  this  nerve  (n|j. 
^'1.  III.,  \^'J.,  III.  II. )  is  a  culiimu  of,  for  the  oiwii  part,  fairly  large  ntulli- 
nlar  calls  Iiinj^  «u  each  sid«  clime  tu  the  luedlnn  line,  iu  the  gray  matter  of 
''  irrairal  ruial,  just  durwil  to  a  bundle  of  fibres  nliicli  wi-  sJiall  t|>eak  of  aa 
l<Migitudinal  puot^rvor  hiinillv;  it  reaches  from  ihe  level  of  the  pcnterKM- 
nmiabwre  tn  iIk-  third  TcnlricJn  to  the  luv«l  of  the  junciion  of  the  anterior 
■wl  posterior  corpora  i^uftdrigeiniiia.  In  a  wcliCMi  laken  ihroui^h  its  middle 
I  Fig.  VJi)  tli«  nucleus  t*  wrn  Io  give  iitT  fibres  whirJi  run  verlicitlly  Uiwaitl 
iha  ttatnl  nirlacc,  Iravcning  the  tegmentiini  and  n  body  ( fin.)  irhich  vrv 
•lull  pfMCiitly  i>|>e«k  uf  as  tho  "  red  nucleus,"  bul  appnrvDtly  nuking  do 
■nections  with  these  stnictiires,  and  pierce  the  median  edge  of  the  pes, 
trging  (Fig.  186,  L')  on  the  surface  to  the  median  aide  of  each  crus.     As 


nchi  4i1«,  tb*  tiirii'n  MrlMam  ■Dd  optio  itMkiaiu  Hai*  brai  cut  swajr  h(n4»nlall)r  lovnnvBUh) 
■IflSh  IU  ot>li'r  Eu  tbnw  lliMt  lalnml  iljveniiw.  L.  lalenil.  E.  P.  rxitnutX  I'mlritm.  ur>l  II,  t:  nH" 
4lui  ivMonor  mAddio  or  Uw  ear<l :  /.  /*.  Infnrtoc  lodiincli.  S.  P.  ni|itrlur  iitduriule.  osd  P.  BiMilte 
rarfuacif  «r  ilrtcnvUltiini.nllcBiaonM.  Tho  doiMd  cnrrM  tln«>.iip)«iwidloi(«r, unibv Hibt 
bairaf  [hi>aKni«ini>iii<'i>  tliBifctied  Bner.t'.  outddcUirnRnreiuisu^asft  Ikseppsr  siul  liivtr 
hiaiMlmisiif  Iheioaaua  Ikstntimi  )»|im.  ThvoiilUua  iirdinlhimli  nauf^ltabown  tifa  liwM 
iU«k  IIb*.  Ill  la*  IIm*  et  Ihe  nnltlclc  ore  tit/wu.  on  llii!  nsTil  half:  ffi.  Kit**  poMv>li''r;  n. 
rH^nnwa  byi<e(lt«ai :  r  or.  irtcoBuni  aoiiUi'iuB  :  1. 1.  •mlorail*  MRa  :  i.  •■.  ilflB  aelMlsiw  on 
4nMt(iB : /. o.  tmm  sainlia:  i.r.  \nc\a  iimiltiwi  t  g.  nlr*  of  VIbuhkbi;  Q^xmuit\ot  unl  <]n. 
■Bi*ili,T(iirvu«i|iM<lit(*aunniD:  /U- |4u(al(l*nili  AV.  UMuntUncof  tbare4iiucloi»:  i,  Uiu  UiM 
naliMa,  In  whli-h  i'  \o»irMi.v  (he  iindilk  iii  koR  MUUOilNnn:  flp.o.  llM  |>Ulai«  of  Uiv  fofalt. 
teblu>l  wWr)il>In-tl«tpl  In  IhcnutiTDrihcllilnl  it«aM*tallisl»llo«a(lb«lnfiioiUbal«im  ('  Cf. 
IksfMniof  ikrnriuaeallouni.  IwtHMn  wbioh  and  ibo  6>mu  IbcntKraAcnalMihsnAli  tcd. 
MWtltlatflated:  r.  partliinolrarmliill'npr  ftonislhtailqAanouiMraak  On  Ois  1*fl  iMs  an 
ii« ■  II .  C&nflui  unaliun  :  O- r.o|i(trihalani»  :  rr.ivlirinu:  7.«LRibm«IiiiaanMtliK:  rt.j. 
HiraaMal  wiinu  miking  lh«  plan  of  neiviliit,  of  lbs  cliuiiailul  iJins.  On  Uit  itKbl  (lilasivaiiiairi : 
S.  C.  Iuad«f.  at,  end  of  tall  of  nuikOf  nuilnlu> :  0|>'.  (^p~ihclini|art*af  tbcgMHiaiallldar.  snl 
n.  Biitswin  f  iti*  niii'kiw  ImilnUrli  -,  .v.  a.  onieriui  biipIhu  .  .V  wed.  intdiui  niKlaia.  -V  bii.  bustsl 
•«(lfaa.aa4  l\'.  |iul<lMr>>r  ibeoi«li>tlwiMn<i>:  Cia,  ftmit  llnib,  <V- <">** '■>' paOi  f>p.biad  tinb 
at  Mamal  raiaole:  O.  evlonsl  oa|*>la:  f-  elauMnis  Ttt  DunMrab  III.  b>  XII.  Indtcal*  Ills 
Mtlu  «(  Ux  iBp»un  onnlsl  mrwt.  alt  tfaowa  nn  ibo  Wfl  tble  wlUi  itw  cteapdea  of  Uw  aciiipiy 
i^aih^i  ibiriiriiil  tX., X.. XI„  nhich «> atotil nahulnn la plarvd lai lb* rifbi  tblB.  I'. ii  Uw 
■MM  nadaiw  at  Ik*  nna  avrn  otib  ilig  dGacoHllng  no.  r.  a.  tbe  wtiKXT  anvlsat  of  iW  •smv 
alt'-  ■>—  >—-.■  -•-■.-'II'  -  "vK,  VIM  n,  nivllaa  nui'ltu*.  Vlll.  I.  latoal  andnis  of  Ikt  ■IkIUoIt 
n,'  iiiaL  TM  atlvnilliiH  nvt  oftba  ntnOi  asm  la  nvn  si  llwWiHttndal' 
■■      .\.X.XI. 


■60 


TirK    BRAIS. 


ire  shall  see  later  on,  ihis  nerve  is  uovr  exolusiTeljT  efferent,  nluitev^  il  mm 
Imvebeen  in  ntvre  primilive  beiii^.  Wesball  also  see  later  ixi,  Itial  iin|iul<r> 
Marling  flxiiD  the  cerebrum  uf  one  side  pose  to  (lie  nerre  ur  ilie  ntlier  Aiilr.  ihni 
ia  to  say  decussate ;  and  litis  is  alsi>  the  ou»e  with  the  other  eflen-nt  cniniu 
nen'cs.  Tlie  fibres  which  B»j>e»r  in  iiikf  origin  from  Ihe  nerre-celUor  tb 
nuoleuD  ilii  not  croe  over  after  enierj^iuK  from  Lh«  nui?l«u«,  but  keep  t'  ■!» 
f»mc  ^litle ;  tlien^  is  no  distant  deens»ation  iw  in  the  cane  just  nuUn  oT  ihi 
fourth  niTvc.  There  aw,  however,  libmi  ^Fig.  lil'2,  111.')  which  Icnviiii;  il^ 
nuckui'  crnM  the  tni'ilisn  ru)))if  from  oiii^  side  to  Lliv  uthe-r,  and  ihiw  (Msibli 
aro  the  iiiithi>  for  thf  d<'[:tiiw:itii(ii  rif  (lie  impuliiesi :  b«it  llwv  ninv  tir  likm 
pasring  irom  the  critK  ncmm  tho  niplio  to  Um'  iiuckus.  I'liw  nam  Iw 
gpecinl  rplnlion*  with  the  'iptii-  tmct,  but  of  tli<»e  we  shall  «penlc  nhm  ■> 
come  to  dcjil  with  tht'  function"  of  the  iicrvM, 

§6Sfi.  In  nttoinpling  t<^>  iindcrvtnnd  ihenntureudrvlaliansof  tlicwtnaiil 
nerves,  it  musi  bo  borne  in  mind  llinl,  while  Riorpholn^cal  Mudtos  lead  lu  ii 
believe  that.  Zf  the  vcrtohratc  t>iiily  hiis  been  developed  out  of  iin  invcrtebnu 
ancestrVi  so  the  brain  of  the  vertebralc  has  arisen  by  a  series  of  niixli&imiiani 
tcom  the  oervoue  structures  placed  nl  the  head  and  around  the  muulh  uf  u 
inverlebrnto,  the  fame  studies  teueli  Uf  that  such  an  evolution  has  bwi 
ac(.'oiopliahed  by  idi.>hdb  of  profound  ehauKes.  We  have,  for  instance,  nturn 
to  think  lliai  the  mouth  of  the  vertebrate  does  not  correspond  lo  the  ntoodi 
of  the  invertebrate,  but  ia  a  new  structure,  whow^  ajipearaiice  has  been  aomn- 
panied  by  a  considerable  dislucnlion  of  parts.  ^Ve  must  accordingly  espn 
to  lln<l  tlie  indications  >tf  a  eeKmenlul  arranKenicot  greatly  nbavund  ootlif 
«ne  hand  tiy  transpusitiou,  and  on  llie  other  by  Alston. 

The  iweltlh  or  hy)>ogluMal  nerve  ia  one  whoaa  natun;  oecju*  fairly  Minplt 
It  19  in  function  exclusively  a)i  elferejit  nerve.  Tlie  large  oclhi.  with  an)- 
nucuous  axis-rylindor  prooCMC*,  which  charaeterin'  ii«  nucleus,  areenctl* 
Ilka  tbow  of  the  anterior  horn  of  the  i>piiial  cnrd  which  give  origin  tollv 
fibres  of  an  anterior  rout.  The  nucleus,  moreover,  in  its  iia«iliun  corropMiib 
to  part  of  the  anterior  horn  of  the  Mpinal  cord,  if  we  tnlic  into  ai'oounl  ite 
shifting  involved  in  the  decussation  <>l  the  pyrumide.  and  in  the  new  develop! 
ments  of  (he  bulb.  If  we  compare  Fig.  1>S7  with  anysMtion  of  the  cnid.vt 
sec  that  the  hyiwglnssal  nerve  correspi>nds  to  an  anterior  root  of  the  spioal 
oonl,  but  that  the  Kbree,  afler  leaving  the  celU  from  whidi  they  takeibtn 
nngin.  traverse  in  the  former  a  large  tract,  and  in  the  latl«r  case  a  small  ttatl 
oftissue.  Whether  the  whole  nerve  corresponds  lo  the  fibres  of  several  scg- 
meniF  fused  together,  or  to  those  of  one  segment  spread  out  loajptudinally,  « 
for  our  present  purposes  of  secondary  importance. 

Recognizing  the  hypogloenl  nerve  aa  the  bomolofrue  ot  a  spinal  antenor 
root,  WL-  may  go  on  to  claim  the  nudd  of  the  third  ao<l  fourth  nerna  at 
^niilar  ki^'1>|'>  "f  cells  of  the  anterior  horn,  giving  rise  to  anterior  root* 
The  {luaitiun  ot  the  nuclei.  Ihe  character  of  the  cells,  the  fnnctiun  of  llw 
fibres,  all  aupport  thia  view.  The  cade  b  perhaps  not  t»i>  clear  as  that  of  tlir 
bypogloanl  nerve,  since  there  ore  reasons  for  thinkiuK  thai  these  ner\-cF  iMn 
untlergone  in  the  eourae  of  evolution  greater  changea  Utan  has  the  hypogUMal 
nerve;  siill  these  reaiiona  dn  not  oppose  the  above  conclusion. 

The  nucleus  of  the  t-.xcliixively  motor  sixth  nerve  doea  not  exactly  ooitt- 
vpviid  to  thcMe  of  the  thini  and  fourth  in  pwitioo;  hut  we  niity  pndialilr 
place  it  in  the  tnmc  «rri(.i>  with  them.  Thus  wo  luivc  iii  auoccwtnn.  the  thin 
itllirtb,  sixth,  and  twcltlh  nrrv»,  with  their  rutpcclive  nuclei,  a*  lliv  antorior 
root*  of  nerviw  of  their  acveral  aegmonU. 

In  tlic  fifth  nerve,  the  di*locaUon  ami  fueioD  spoken  of  above  has  iatit^ 
duom)  diSiculti'v.  The  motor  nucleus,  with  the  fihn*  of  the  motor  rout  i'> 
which  it  giveaurigiu,  has  by  some  lieen  conndered  m  homologviiis  to 


OltAV    UATTBB. 


rBi 


jii»l  <lo»PtibMl ;  bill  it  is  at  onc«  AbvioUB  that  we  cuniiut  look  u[)od  tliU 
lil\ti  nerve  as  correitpouding  to  one  H(>i»al  uerve,  niili  kit  ulterior  ami 
t>u«teri<<r  nol,  mat  m  tlie  Buper6ci)il  resembluwe  Beenu  to  be.  The  fenUirts 
•  •kf  the  TeliMirksme  oteeading  root  forbiij  this.  The  Rhrcaof  tins  root  taav  be 
tnoed  hnok,  w>  we  bav-e  Mid.  to  the  very  beKiiiuin^  of  the  bulb,  and.  iiKleeil. 
Into  (he  ipinal  cunl  Iwyood  ;  as  (tt  as  can  lie  aHL-oriaiued,  ibey  are  not  iu  ild 
ubviiiua  iu»l  direct  inanDer  L-oiiiieoled  with  ii«rv«-eells  alou^  their  couru; 
but  the  bundle  »r  fibre*  diu^pt.  as  wl-  have  seieu,  to  the  fcelatinoii!!  aiilMtauoe 
uf  the  iKMterior  horn  of  the  npinal  cunl  and  to  the  cnntiuuation  nf  thin  along 
lb*  b«ilb,  mad  Ihe  Ghm  are  lost  in  thi«  sinirture.  Tli«  rout,  tlicreiori^  a«  «re 
hiTO  Midi,  oonTHMiKls  very  cliiwly  to  |wrt  at  leuvt  of  the  pwlcrior  root  of  a 
ipiaal  nerre.  and,  Iboiigh  ine  matter  h«*  not  yet  bven  experinivatnllr  proved, 
>ro  may  infrr  that  the  tniphir  cnntrtv  'if  tliew  Gbrcv  w  lo  Iw  found  in  tli« 
pdk  of'^  the  Qanerian  ganglion. 

B«it  if  iheascMiding  root  b«  of  tlw  naitirv  of  a  pu)l«rior  root  (and  we  may 
facMeotilly  remark  tnnt  the  term  asoendiDZ  Uiu>  been  unhappily  chmwtn. 
phioe,  if  it  be  an  alfetvni  mot,  the  direction  of  the  impiiUt:*  whiL-h  it  '-arriw 
irill  be  a  <)<WM>n(ling  <>mc,  iinniely,  from  the  entrance  in  the  pons  unriiftl  the 
hin<liT  partiif,  we  ran  hardly  siippi.ei'  that  it  btiloii^  to  a  single  i>egroriil,  or 

tthe  L-ompleaiNtt of  the  motor  root  alone;  in  it,  most  probably,  the  poi^- 
rior  libf«6  of  several  fie);meul#  are  blended  together.  Further,  we  may 
perbiipe  inter  that  the  other  libree  of  (he  Ben«ory  root  which  end  directly  in 
iVhat  ire  have  culled  the  Eensory  nucleus,  are  in  nature  quite  distinct  from 
the  tibree  of  ilte  ascending  root :  and  if  so,  diffiotiltiea  arise  oa  to  the  nature 
«ik1  l>omolo|[i«i  of  the  nucleus  in  question.  These,  however,  we  must  not 
IdlaouM  here,  Dor  can  we  enter  into  the  question  of  the  nature  of  the  deecend- 
ting  root,  conc«ruing  the  fibres  of  which,  as  we  have  said,  auth»riti«  dill^r  as 
|lo  whether  they  jaw  into  the  niolof  or  wtuory  root.  We  have  said  enough 
llo  ilinTr  that  tlii*  lifth  nerve  in  extremely  complex,  ami  that  ilv  apparent  con* 
formity  tn  a  «implc  spinal  nerve  \*  in  reality  mialeading. 

The  tibrea  of  the  vagu?,  glouD-plinryngeal,  anil  hiilhar  acotwtory,  mkeii 
logMbcr.  arc  partly  cftVrcni.  partly  alli^iroot.  The  combinr.fl  nucleus  of  these 
Ithree  ihtvoi,  the  orllx  of  which  an-  small  and  dcvuid  of  conspicuous  axi§- 
icylinder  {irocessee.  is  usually  rcgan)<.->l  a»  n  M>ns'>ry  nucleus,  and  in  the  dia* 
Igram,  Fig.  193,  is  riiaded  aocordingly.  It  may  jwrhaps  be  oumparrd  to  th« 
fiiniry  nucleus  of  Ibe  fifth.  Thu»,ttie  oscrndiiig  root,  or  fasciculus  soHtjiriua. 
presents  many  analogie-  with  the  ascending  root  of  Ihe  fifth,  and  we  are  ltd 
bo  r^anl  this  as,  like  it,  a  gathering  of  tvriain  allcrent  Gbrea  of  the  poetenor 
boots  of  several  segments ;  in  its  case  also  the  lemi  ascendiDg  is  niflleadtng. 
Bill  there  are  many  difficulties  in  ooiiiieetion  with  this  nucleus,  as  with  tne 
fifth-  We  must  not  enter  into  a  detailed  discuwion  conoeming  them,  but 
nay  rennark  that  we  have  here  perhaps  to  deal  with  complexitiea  due  to  the 
Ihct  that  certainly  many  vagus  and  glosao- pharyngeal  durcs,  and  probably 
lotoe  of  those  of  the  fifth,  an-  apianehnic  in  funotJoo. 

The  nucleus  ainbiguus  (vntatns  largu  cons|>tcuoua  cells  and  we  may  proba- 
bly regard  it  as  u  motor  nui-lctu,  i3i[M<oially  of  the  vagus  fibre*.  We  may 
•no  perluiP)  place  it  and  the  nucleus  of  the  m^venth  nerve  in  the  same  cate- 
gory, and  lurlher  i-laiv  with  them  the  motor  nncleua  of  (he  liftli,  looking  upiia 
■U  three  ok -v)  many  detaehed  [MrtJoni  of  gray  matter,  corranondiiig  to  some 
Dart  nf  ibc  anterior  horn  of  the-  siiinal  tv)r.l.  Whelhor  tney  are  exactly 
■onologous  to  the  hy]iogl-j««d  nncl<-ii«.  and  their  fibres  to  simple  anterior 
roots,  is  not  so  clear. 

Lastly,  the  auditory  iH-rre.  both  from  its  character  as  a  nervo  of  siKcial 
trnoe  and  froai  the  remarkable  IVaturas  of  its  niieisi,  bevtn  more  difficult. 


■62 


THE   BRAIX. 


M(wt  i>rubiitblir  it  rcsiiltii  from  ihe  fttkion  <■>'  niore  roola  lltsn  tim;  Iwi  itn 
iiupoauble  ni  pivMiti  to  obtniii  «  ulor  owception  of  the  nnUirc  of  iba  ■!  ' 
nerve. 

3,  The  Sup^rfifial  fimg  JAiW<r. 

§636.  Tbowboleof  ibfi  suriiiccofvnch  cerrhml  h4-nii>irher«  for  funis  Uilr 
depib  inwiinl  consiflf  i>f  prav  mnlter,  |>i>«w»ing  ■[lecuil  ebnm'     '  :• 

nllc<)  tb«  uorlicnl  pny  mailer,  or  ihe  rortr^  trrrbri.  or  nhortl;.  it 

tlw  eorttx.     As  wr  »IihII  *ce,  bv  il«  tiistolomiMil  nnd  still  nmrc  bv  lu  {•Ihm- 
bifiionl  frnliirrf.  it  MiuicIh  apnn  from  nil  oilier  kinih  of  gmv  iuiiEIlt. 

Tbc  irhrlc  of  [he  surtiii'e  of  ih<?  et  rebel  In  ni  is  nlwi  eov-crni  wilh  jtrai  luait't. 
whi<'b.  wbile  {>o»«;f sint;  lenluree  of  il»  own,  so  far  rawiiibic  the  cvrvbrnl  oir'.(i 
ill  ils  hislulofiical  clmraoter^  ibai  it  too  htis  bei'ii  spoken  of  u  ooriex,  m  itr 
cortex  cerebclli.  Itv  ilH  fimclioDal  niauirratalioD^.  however,  it  iliflvK  *Mi 
tnttu  the  cerebral  corlex  ;  and  mik*  ihereare  muny  advantages  rn  Wiiix^li 
la  use  the  ffbrd  cortex  in  eoniiecliun  with  the  c«rcbriini  only,  it  ti  ilmriliii 
not  to  Hpeak  nf  a  cerebellar  eoriex  but  to  employ  the  lemi  "superficial  fm 
mailer  of  the  oerebelluro." 

The  third  ventricle  and  the  biuder  purt  of  the  fourth  wntride  an  fi 
moled  in  by  nervotia  uiaierial,  and  potirSfl  no  superfieial  gt:ay  raullei  it ' " 
In  the  corpora  i(uadngenitna.  «  hich  funi)  th«  rtM>f  of  the  a<|iieduci  "^  < 
nf  the  niid'brain,  j;!nir  niutli-r  !-■>  pretfent  and  poMeMM.  in  the  cum:  "i  u<- 
anterior  corpora  'pindriici-iuiuii  at  feiut.  churadersi  to  a  certain  cxinit  uil> 
^OUB  tu  lho»e  of  the  eurti-x  and  to  the  ccn-bt-llHr  AujM'rfleial  tfray  matUc  ltd 
It  will  he  best  t(i  consider  the  gray  matter  of  Uivw  bt>lie»  »  "^  ' 
another  categurr. 


3.  JTtf  InUrmedittt«Gnif  Mnttero/lheCrttntl^tlm. 

S  fl87.  W«  hiire  seeti  ($  WM)  that  Ihe  cnira  cerebri  form  llw 
pan  of  A  svEtem  of  loDgicuiiiDal  tibrefl  MrelcbinK  from  each  ceret 
Rpltere  to  the  bulb  and  to  the  spinal  cont,  Tbt«  system  of  libre»,  upoo  mM 
we  may  consider  the  various  pans  of  the  hrain  to  be  as  it  were  fouD'M,  ■' 
may  speak  of  ae  the  crural  aysleui.  It  is.  it  is  true,  not  one  eontioun* 
strand,  but  a  number  of  diRerenl  »traiids,  having  diderenl  be^inniii{p  id1 
endings;  tint  these  all  contribute  In  the  crura  ami  are  so  far  alikeaslojotlili 
us  iu  considering  them  ««  a  sydteui.  The  cortical  gnty  matter  of  (■chbnal- 
qibere  is,  as  we  iliall  m-c.  omnecud  with  vurtouapiinaof  ihit>sysleia.*tuliD 
oufl  sense  we  may  regard  ihi*  nMrtn  a«  heginniug  in  ihe  cortex  ofwi 
hemisphere,  and  emliug  in  the  npinal  ciml.  But  certain  mniw*  •■(  ^^ 
matter  in  (be  bewi:<pher«  not  »trictly  cuTticul,  and  wretal  ini|>i-rtniii  m.-i*H> 
and  arena  of  gray  nuitlrr  lying  brineen  the  hrminpherv  and  'I 
ronueded  «ith  ltie*y*ten> :  nnd  th^^tr  n<>  may  .■'pi-ak  of  a*  the  '  n 
gray  niatier  of  the  mif^t  nyxtcm." 

(.^fptif  Kiriiilum  and  </ftlie  ihaUmv*.     Of  nil  the«c  novtrnl  collectinR^  -' 
gray  mailer,  the  hirgct.  moat  coDipiciinHi,  and  perhapn  ibc  immt  iin 
nre  the  two  nniMHv  in  the  front  part  of  the  systom  known  as  ibe  c»r|" 
turn  and  optic  ihulamup.    The  former  is,  as  ne  have  mn  (§  603),  a  ■■' 
m«nt  of  the  wall  of  the  cerebral  vesicle,  iho  latter  a  dcvelofunent  n(  i 
of  the  ^'eaicle  of  the  third  tentricle.     They  are.  tberelore,  of  diflereai 
allboiigh  ill  lh«  oniirM  of  the  growth  of  the  brain  they  become  eloselv  au. 
to  each  other,  they  are  at  the  outset  rjiiite  separate  and  distinct.     Mort 
an  we  slinll  see,  they  differ  front  each  other  bo  eaeeutially, in  their  naiurri 


TUK    GRAY    MATTER. 


rus 


nlatiana,  ihut  ihry  rniinoc  be  coitfiHercd  as  hutnulogouB  bodies ;  bdA  llie  lert» 
"  bHil  |riiii)i;lia  "  ••Adi  «]i|ili«d  lo  ihrm  i*.  therefore,  unrortunale.  Neveitlie- 
k«8,  it  will  render  ilu'  iltxcnjition  of  tb^'ir  luiirgrnpliicBl  relations  eaakr,  it' 
for  n  little  uliile  ii«  coi»i<l<'r  ihi-iti  ingi-lhtT. 

When  the  latent)  vnilHcK^  is  liiiil  o[>tn  from  above,  iiart  of  the  corpus 
■Irialiini  it  m*ii  pr<ijnrtii)}i:  into  the  cJivily  of  (ho  vcntncli-.  I»  fn>iit  the 
prnJMtlDg  part  i«  lironit,  Innnitie  thn  lateral  wall  niiil  iiait  <il  ihe  ll<M>r  of  tbe 
reniriotv,  and  to  it>  nn-ilinn  nitli-  lies  ilw  ravily  of  im-  vi-nlricle,  i«|iarated 
tmm  it*  fellow  by  tbi'  crplum  Ineiduni.  FiirlhrV  Iwck  tbe  proji-i'iing  part, 
beoomtna  ^adtinll/  tiarrowcr,  nminHs  a  mori?  lateral  pwitioii  and  pawn 
bito  th«  dtMending  hem.  In  (his  rnrt  of  ii«  couno  there  lie«  on  itk  lunlian 
tide,  wpamte'l  fn^m  it  hy  a  narrow  band  callod  the  tienia  seniieircularb  or 
stria  tcnninali*,  the  optic  thalnmuB.  a  oarniw  Anp  of  the  siirfiice  of  which 
It  aven  projccling  out»idc  th<>  edge  of  (he  choroid  niextia.  If  now,  nitt  only 
htAlt  lattTitl  Tcniriclet  be  laid  open  by  reinoral  of  the  corpus  calloxuin  and 
Ibe  fornix  with  the  velum  int^rpneiliini  and  choroid  plexus  be  taken  away, 
>o  a*  hilly  lo  expose  the  third  rentricle.  but  also,  in  order  to  obtain  a  better 
view,  ibe  orbolc  of  the  hinder  Dart  of  [he  cerebrum  coDCainiiig  the  poi'teriur 
borna  of  the  lateral  ventricle,  tie  completely  cut  away,  it  ja  seen  (Fig,  1!^>^) 
that  (Im-  two  optic  ibalanii  {O.  T.)  preeent  ihemaelva  as  two  large  oval 
bixUe*,  placed  oblitjuely  athwart  the  diverRinjc  crura  cerebri  and  convfirgiiig 
in  front  to  form  the  imiutdinie  walls  of  the  third  ventricle.  In  fri>ni  and  In 
Ibfl  Mdf*  of  the  optic  thulaiui  are  seen  the  cor|^>ra  iilriaia  (  f.  -V)  foroiiiis 
■ntvrtnrlr  the  lateral  waJ  In  of  the  I  wo  lateral  ventricle*,  and  dirergiiuc  behind 
lo  allow  (if  the  iDterjiosilion  of  the  optic  ihalnini.  Ou  each  >ide  of  the  brain 
then  ihcK  two  bodies,  tbe  i-or[uis  Mriatiini  tiiid  upti<-  thalaaiUK,  np|ieur  as  two 
maiwes  of  ^y  matter  placed  on  tlie  crus  cerebri  ai  tbi»,  diverging  from  its 
fellow,  befina  to  spread  ou(  into  the  cervbrei]  hcmisph«r«.tlic corpus  alrtaluiu 
beinc  placed  fonicwhat  in  front  of  the  optic  thalamus.  Th«  relationit  of  the 
two  hodirs,  moreover,  arr  such  that  while  the  optic  thalntnus  alone  forms  the 
wall  of  the  third  ventricle  to  which  it  properly  beloDfjs,  and  th«  oftq>U'  Mria- 
tutn  forma  jvrt  of  the  wall  of  tbe  lalcrat  ventricle  to  which  it  in  tuni  pro|>- 
eriy  beloon,  the  optic  tlvalamus  also  projects  into  and  seems  to  form  |>nr(  of 
the  wall  <^  tba  lateral  vciilrtcle,  though  at  its  origin  it  had  nothing  to  do 
with  tka  eor«bra]  rceicic. 

We  apoko  just  now  of  these  bodies  as  l>eing  placed  on  tbe  crurw  cerebri, 
IniI  though  their  dorsal  surfaces  ihiis  nri>ject  from  the  donal  surlace  of  tbv 
dlrerging  crura,  a  larf:e  portion  of  each  Itody  is,  io  lo  sneak,  imbedded  in  ths 
BubaUuice  of  the  divorKi'iv  crus,  and  what  ia  aeen  in  the  above  surihce  view 
is  only  a  part  of  each  body,  and,  indeed,  in  the  case  of  the  coqwa  Krialuni, 
only  A  small  part.  In  order  lo  understand  tbe  nature  and  reUtions  of  lh«w 
two  important  budira  we  must  Miidy  aeetionH  taken  through  a  cerebral  hemi- 
SpherM  in  varimis  planes  (Figs.  1!H-201). 

Each  cms  is  made  up  as  we  have  seen  of  a  doiani  portion  or  tegmentum 
consisting  largely  of  gray  matter,  and  n  wntnil  jiortion  or  pes  eonsistiBg 
exclusively  of  lougit^idinally  ditposod  tlbm.  The  tcgmmtMm  end*  partly 
ID  structures  lying  ventral  (o  the  thalnmits,  pwilly  in  the  thalninitn  itself; 
kJHJ  we  ntay  for  the  present  Iraw  this  part  of  the  cms  out  of  ctiii»i deration, 
Tbe  fibres  of  the  {ic»,  while  conliniiing  their  oblique  course  forwnni  and  out- 
ward, soon  rite  don«IIy  by  the  lude  of  lli«  thalamus  and  hence,  in  a  trana- 
verse  dorwweotral  section  at  the  level  of  (he  hind  part  of  (he  thalamti*  '  Fig. 
194),  are  aeen  Icavinj!  (lu-ir  previous  position  veniml  lo  the  substatilia  nigra 
iSn)  and  |«ning  (Cip)  hy  tb*  rid«  of  tlw  ihaliimiie  on  their  way  (n  the  cen- 
tral while  matter  I'f  the  hcmisnbere.  In  this  part  of  their  coutse  they  fonn 
n  thick  strand  reparating  the  ihalanius  (In)  from  k  large  maa  ofgray  matter 


Moei  finilwbly  it  resiiUa  from  lh«  (Visinn  of  inons  rwrts  iImvd  oil*;  but  ii  ii 
i»i|K«0ible  al  presetil  i<)i^>Uuh  a  vtear  oonc«|)Uoa  of  llw  tiKlure  uf  ibt  »)' ' 
uerre. 

■2.  The  Superficial  (imy  Matter. 

{  6S6.  Tbe  wbi)l«(iriW  *urf»c«of  Mch  cen-bral  hemisphere  far •uine  ItUir 

cailcil  the  coitinil  mv  nm(l«vr,  or  the  rorltx  eetrhri,  ur  hHotIIv  iiti>i 

Uk  cortex.     Am  wo  diflU  fe*s,  liy  iu  hintolwiinl  mxl  »till  mora  by  ilo  )ih}  mv 

logE<-Bl  fi-HUirc».  it  »tiimlii  aimii  from  all  mher  kiii^I*  "f  grav  inKi'ler. 

Tb*  whtjlcof  theeurfiirctirihi'rcrrlM-Uiim  itnilwi  covrrr^I  *ilb  ([Ti)  ' 
nliurb,  wbil«!  jxKWMing  Ifnlun-n  of  irn  own,  w  fur  rii*-nitilc  the  cerrhn 
in  it*  biKluUieical  rhBritclen  Ihm  it  loo  lii»>  Ix-i-n  .-i><>k<'ii  cif  an  i 
cortex  crrabcili.     Hy  ils  functional  inanir<>(iiiii>iii>,  boni'vor.  il  li" 
from  the  c>.Ti'brKl  corI«x  ;  nwl  ^imr  ihcmnrr  nmuy  ii<1viio(nc*«  in  t^ 
to  um  the  vroxl  c>i1«x  in  coniieditjn  with  tbc  nn-bnim  ou^.  it  in  •!'    ' 
iiot  to  tfi^V  of  «  r^rcbellnr  cortos  but  to  rniploj  tbc  lAnn  "Nuporfidtl  ;r*T 
nintt«r  of  tbc  ccn-belluin," 

Tbe  third  vfiiirick  aitd  the  bin(l«-r  part  of  ihe  Ibtirth  vp»ir>L-l«  nn'  dm 
routed  in  br  nervous  nuilerial,  and  pMtves  no  superficial  gmy  nioltrt  ft  'i 
In  th«  rorfmru  qiindrigcniina.  which  forsD  th«  roof  of  the  mquediiLi  f\ 
of  the  mid-bniin,  ^nty  malter  b  preeent  and  pomeses,  in  ih«  ciu<-  "i  i" 
iinterior  corpora  (jUAdrigemina  at  koM.  characters  to  a  wrtain  <?x(«tit  aiioi'" 
gotiB  to  ihoee  of  tlie  cortex  and  to  (be  cereiiellar  euperlicial  gny  mallvr :  b»l 
it  will  be  best  (o  concider  cite  gray  ntatler  of  thcee  bodtee  as  beUwi^tt 
another  caUnory. 


•1.   The  Intenwdiale  '>/»y  Matter  i^'Ae  VkKrtU  Sgdem, 

S  6S7.  We  have  ifeii  (S  (WO  that  the  crura  crrehri  form  llw  iimmttwni 
part  of  ■  ijrMMB  of  lon^iludiiinl  librm  ■■(ri-tvbin);  fnvm  tiich  ccnrbrni  '■ 
spheraiA  the  bulb  and  tn  tbi-  ipiiinl  conl.    Tbi*  «yiitein  of  Hlirea.  a\m'. 
•nt:  mny  convidrr  \hi:  vnrioui^  jinrls  of  tbc  brain  to  bo  M  it  ititv  fmiti:' 
may  i<|icak  of  a*  lh«  critnil  (yaU'iu.     It  iji.il  in  tni(%  not  <>»■-  <   < 
Mrand,  bm  a  nuinlK-r  i>f  difl^rtnl  Mrandii,  hnving  ilillt-mit  \*;\l 
endings;  bnt  tluvenll  voiUrilHile  tn  ifae  cnira  am)  an-ti»far  nlikt'.j- .  - 
ui  in  coDcideriog  Ihrni  no  a  syHtcni.    Tbo  oirlical  gray  inntX'r  of  cai-h  bivi- 
•phare  is,  as  wo  shall  ee«.  cnnnoctcd  with  various  yunt  of  this  sreh-ui,  inil '» 
WMWfwewc  may  n-eard  this  syMcm  as  begini>ing  in  iha  conex  of  iMch 
hrtniiiphcrT^  and  ending  in  tin-  spinal  cord,     Hot  nrrtain  masea  ofgn^ 
mailer  in  Iho  hvmispbere  not  slrit-tly  cortiral,  and  Mrt-ral  iiniMiirtaBt  IMMR 
and  areas  nf  gray  matter  lying  between  the  bemiepben-  and  Oi 
fonnccted  niili  tbeByslem  :  and  lbet«  we  may  speak  of  as  the  "  .n 
]fniy  matter  of  ibe  crural  »y^tem." 

(VrpHf  Mrintvfn  and  optic,  tkatamu*.     Of  all  ihese  seTenil  O'Def^i"!)*  -^ 
gray  matter,  the  l«r:g6M,  moM  oouspicuous,  and  perhaps  the  m"-: 
are  the  two  niassts  jn  the  IVoni  pari  of  the  syalem  known  a»  ih'r '     . 
lum  aod  opiic  llialaniu*.    Ihf  linmer  ia,  as  ne  have  seen  (§  fiOI)  i,  a  <i' 
menlof  tlie  vail  of  iJie  cerelinil  veniuie.  tbo  Ult<<r  a  development  nl'il 
of  the  venicle  of  the  lliint  ventricle,     Tlii-y  an-,  llit!ri--ffin>.  >>f  diirvrtm    i  . 
■UhodKh  iu  the  counte  of  tlie  growth  of  ibu  brain  tbvyb4>c»iiM>cl<>«ely«iir 
to  eacn  other,  tbey  are  ul  the  tmtMt  ({uitc  tcpanito  and  diitincL     Mi  < 
as  we  shall  see,  tbey  diffbr  fnun  nxth  olbcr  so  CMCOttially,  in  tbcir  naluu  ~- 


THK   GRAY    MATTER. 

ioD»,  ihnt  tli4-)r  cnnii<>l  )>e  coit»i<lcr«d  as  liatnologau*  bodin ;  and  tbe  1 
^  hMil  Knnglin  "  ••i\ta  applied  (o  ihcm  i«,  th«n>forr.  unronanalc.    ynuilfci 
Iwi,  ii  will  rctiilor  the  description  of  iLdr  topogniplticB]  nlatioM  ««Hr.  S 
Jnr  a  little  while  we  coD*ider  them  lo^elfacr. 

Whm  the  lueral  vcniricle  ia  laid  open  from  nbovi;.  f«rt  of  the  («^» 
■iritttutn  ia  »eeii  ymjvciiug  into  the  fuvity  of  the  rcntnelr.  In  flMn  «W 
prDJrnin^  purt  n  linwd.  foriiiiitK  the  tuleral  Hall  and  Mtt  i>f  tb«  i 
vrntriclr,  aiid  lo  it*  nK-diau  side  lit-A  tbe  cavity  of  iW  vnttiidt^t 
Inaa  it*  fellow  hv  ihv  trptuni  lucidum.  Further  back  tbt  faijaataf  ^■'t- 
bteMnins  gradually  nnrroiner,  bmuiik*  a  luore  lalervl  pMliBB  md  fHM» 
Into  the  dMCMHliDg  Imrn.  In  ihiii  ran  of  io  counte  thnc  fia  M  iSa  mBm 
••(Ic;  w-|iaralc<l  fh>in  it  hv  a  oarmw  hand  ealM  the  iKsia  MBMomlaB  ^ 
airia  tvrtDiDnlt*.  the  a]>lic  tbaliiniii*.  a  narmw  ^np  of  ihe  wuhm  4f  vteA 
b  ttfn  projodinj;  uulwth;  tbe  vd^  nf  ihc-  choroid  plexBL  If  : 
both  lnli.'nil  rmiriclea  be  laid  i>iH.'n  by  reniovnl  or  tbe  «oipa* 
lite  fortiix  with  tbo  velum  iiiterpiwiltiiti  and  choroid  plotaa  kr 
»■•  p*  lulty  to  expose  the  third  TODiriclc,  but  nlao,  in  eadar  •»  at 
ri«w.  Ibe'whotv  of  Ibc  bitidi-r  pari  of  tbe  orvbrum  onotnniar  ^  '^ 
of  the  lateral  venlrich-.  be  COtnplMely  cot  avar,  it  m  «n:  Ts 
the  two  opiic  ibnianii  {(>.  T.)  prrvi-iii  tbeoatlMi  a» 
»,  placed  •pblir|ticly  athwart  ihc  divir^ine  eran  mrfK 

fVont  to  form  tbe  tinniedialc  walU  of  the  third  VoMddft.     Ifc  l 
the  tidn  of  the  optic  thalami  arc  «cen  lh«  <«rpwi  ani»  'C  £-i 
■ntrTinrly  the  lateral  walls  of  the  two  lateral  reDtrictnci 
|(>  allow  of  tin  ioterpotiilioii  of  the  optic  ihalaisi.     Ott  i 
then  these  two  bodictt,  the  corpua  flnaluni  and  oyUr 
muHra  of  gnf  toaller  placed  on  the  cru*  rrrwbri  ■■  Urn 
fellow,  be^na  to  aprvad  out  inlu  the  cerebral  *      -    •    -  - 
't^nc  plared  anruewhat  in  fh)nt  of  the  ofAic  t 
two  Wlit*,  DMiTTOTer,  un  iinch  that  while  tbe  i 
wall  of  ih"  thini  reniricJe  to  which  It  prripBl^ 
tnm  fiirnia  imrt  of  ihr  wall  of  the  lalvral  r^Ot 
crly  Iwlonva,  tbe  optic  ihahtnioa  aUo  jirwicfaa  MOt'^t- 
thr  wnlt  of  tbu  lateral  ventricle,  thougli  ai  b*  • 
with  thr  crrehml  vr»i.'lc. 

\V>.  •[liihi-  jimt  itiiw  iif  tbe«r  Ii>v)m«  i 
t     ■  ■  ■    ■  '■>ir  (Inrul  Buit  - 


'  >  A  tiiian  [art. 


4 


7W 


TUE    BRAIN. 


which,  niughly  Iriunifuliir  in  »evtioo,  is  divided  by  iiiirtiti'm*  if  wliiu  iuit«i 
into  tiiTve  jiarM  ( tip',  <ip",  PI  \  and  of  wliicli  we  snail  i^jteiik  direcilv  ■*  ibt 
niicleUB  leiitii'iiliiH^. 


PM.IM. 


\ 


.IV. 


•r 


\ 


V.3 


-M4 


'v 


'v'^"^:; 


> 


ty.d 


y 


tNMia-uoi'TicOiiUMetir  i  Tiit!«vcnut  i>oii9D<vK<itiii-  )-u:ii<»  maut-nn  the  Iiiu4n  111 
iMii^ti,  tl  Lkvil  PimiMDii  iiirtiE  KxElur  t>ilM(a-vii.  r,ir>|iLi    <ii»uii.'uJTa>.| 

He.  iiui.-lo<n  aititatiu;  In  (bo  uppBr  pKrtoT  iheflnM.  ihaimlloaarilicniulein  h  ikiMikl 
MMiOUVt  M**!"!' *t>Ich  (uec<i«di  Ihu  wHur  fruitl  vi><1  or  huiHl:  in  Ih*  lowvt  pui  n(  tlM%iitl 
WMlda  p«i«ai>  Itironch  (he  lall  i>r  iric  iiui'lcui  iimr  Il>  mil.  una  llil*  |snlnii  of  It  ka*ftirll»«Ui 
«lmnie»  beta  •UQ-U)(«d  fmoi  Uio  trmj  imtivr  of  .Vu.  ducIciu  unfv^U*,  man  lUilla«il|  UMl 
NalUf  i>  Ihr  •^*H.    ^',  dp".  hIoUiu  |■lUl<Ill^  1H-U  Uunlu  Iku  xvmtob.axl  K  pUtMnni  *t  taiMi 
toaltcubrt* ;  'IT.  lilt'  aiitmnr:  (tr.  itii<  iiiiii^i.  nii<l  la,  I  lie  lalvnil  niicloai  u<  llw  opHc  iIkIiobi* 
«t<»liihi.-*  iMIlesl  la)vr"  Ijinit  duii  <»  (.v.  Uie  inBUrlor  liDitiof  Uic  lu«cre*lcii|aiilcMl«» 
Mlalnc  uiMin  iiruidi  »(  itlim  u]ili-li  iiiliiKlt  wlIU  It     In  llir  IIimttmiH  balwvrn  tbf  anlMMK^ 
lotrnikl  niirlrioii  Diiviii-  IiHti>1  nii-l  llv  liilrnil  niivleu  mi  tlir-tlhcrlta  Ujrr  •lia'lnl  lea  >W1)  O 
%ht  flpipc  r«i<«entlntf  ibt  liiti^ma]  iiiolu].lur)'  Uiuiiib  nf  iJii*  iliaUpuw^  cuiuLi41ii(  IvntctfOi  *t* 
nUtMT,    iflhvrcullKiiviu  of  nblM  mttlcr  wllliiii  tlu-  llialaiuiu  aiv  llvUiv  buadltril  \10|  4'iiR. 
HOd  f,  I  III'  Innmrii-I  of  Ih«  aiite'riir  iiUbirnr  Die  funilt :  /'  Ihtf  upfa)r*o-l  of  tbcuiHlM|(U'^ 
tIM  tvBti.  Ulm  If.  (III!  cotinu  ckllwiun  ;  tub,  cut\mt  lubibaUuileUK.  runnJui-  •>  f-i->ii  niuluia* 
BUM  «rul>  tbt  Uultimu;  .^ . >utM*tiiln  iiign:  rL <>i»i'i[iuu ;  ct.  oiMnwl  ' 
■•onioa  of  AiitafotccuimlHim  :  h.  Itir  IiifiiU or  lulniiil  o(  ICfll ;  tt.Mnairen'  i.<  .<  ■  ■^■ 

lnt^utnvt  iMItni  ntmilvle;  I'.S.  Im  ihu  rulUou  ufiliv  Uilnl  renuicle;  ItKiHiUiiiaiil  lUWiaa 
•TV  iiwAc  ■UifninmulMlIf  •IMloc*  b}  Ihlrk  liWk   lliiu*:  0^.  ot'lc  tr*c<-  f>.  P.  pUMll  < 

r.  uinp-mi  Me. 


THE  ORAT    MATTER. 


If  iuiileiid  of  (flkiDg  a  traiifvoreo  Be  tuliP  a  lon)»ilutlmaI  doreO'VC'nlnil 
Kor  as  it  »  called  !a|>iital !  amotion  (Fif;.  2U(I>  wc  lind  ihsi  tbe  librae  loruiiij; 
|fhe  Mranc)  in  c|ua(i(>n  ilo  not  coniiniie  pnriillel  to  each  other  as  they  riw  dor- 
■bIIv  bill  diverge  in  a  rsdiatini;  ninnner,  Inriuiii);  the  eo-calied  corona  radiata. 

5f  a^ain  we  take  hDriutnial  seitiona  at  i>ro|)«r  levtU  (Figa.  19S,  199),  we 
tid  that  thb  Blraod  or  rather  thick  haiid  -if  doraally  dineoted  radiating  flbm 
^ot  only  Btretcfaee  l,f  Vp)  between  the  thalamus  stid  the  firay  iush  juU  kpoken 
pf,  but  reachinK  farther  forward  panea  { da )  Ix^iwueu  {\v-  »ain«  gniy  maw  on 
the  bieral  «ide  and  anutlier  cray  man  (J\»  on  tin-  mtdiiin  tide,  the  lalti'r  fVum 
kji  |H<Hiiti)n  being  evidently  the  {lart  of  the  curfius  etriatuui  which  |)n<im-t)> 
Inlo  the  lateral  ventricle.  The  uiiue  hoiiiontal  «eetii>i»  ftirtbcr  («ach  ii»  i  hut 
|he  front  j^urlof  the  hand  (Cia)  ia  bent  at  iin  angle  upon  the  hind  |>iiri  I  dp). 
1l  upiK-urs  then  from  these  tectionti  that  the  fibre*  nf  the  pe»  a*  ihey  rite 
hp  dorauly  into  the-  heimaphere  uprend  ont  in  iho  form  of  a  fan  hr-nt  u|Hin 
Itoelf.  ThU  run-like  cxpaiuion  of  the  pen  is  vall(-<l  the  ini'-rn-il  caiauir,  tho 
%ngle  funned  by  the  bend  bein;;  rallcil  iia  gnni  or  kntv,  {C'iji  i\w  juirl  in 
!(r<int  of  the  knto  thu/r'^nf  limh,  und  lli<r  pnrt  iH-hinil  tlie  knee  the  IuhJ  limb. 
'And  horizontal  M-ni«nH  iit  lirvelit  more  domal  than  thiw  given  in  Fig».  193- 
,19'.>  would  »hnn  that  the  lihmt  componine  ihb  fan-like  intvrnal  oa|«iil«,  as 
'ifaey  rofe  doiNtlly,  curved  auiiy  in  variouH  dirctctiooH  U>  reach  nearly  all  pans 
tf  the  furlaoc  uf  the  hi'iui»|>ben-.  We  nuiy  add  that  though  the  internal 
lapeule  is  mnibly  cnaiprHW*!  of  librei!  whieh  tliu»  strt^tch  all  the  way  from  the 
Cerebral  cortex  to  the  pea  uf  the  cru»,  it  also  cuntainR  other  fibres  of  which 
we  »hall  *peak  later  or. 

<  1;  028.  The  gray  mniw  leparnted  from  the  thalamus  bjr  the  hind  limb  of 
ibe  internal  capeiile  is  called  hh  an  hole  itm  nueleuf  feiiticiilaru,aace  in  hori- 
■ontal  Hdion  it  presents  a  cerliun  ihoiifth  distant  resemblance  to  a  len».  Of 
the  three  divisionH  inlo  which  it  is  xplit  up  by  the  partitions  nf  while  raatter, 
two  median  ones  Up'.  Up",  are  spoken  of  together  as  the  g/of>ui  pnlliilnt. 
Dame  being  mea  to  them  on  account  of  their  |>a)er  eolor.  Tlte  third, 
leral  diTtwoD  f/.  tft  called  the  putaimtii.  The  use  of  these  tno  nanie^  for 
e  two  difi^rent  parts  of  the  one  bo<ty,  ap|)eani  to  lieju^tiRed  by  the  different 
nections  and  leaturf«  of  the  two  parts. 

The  gray  nisie  which  in  a  horiiunial  section  (Fig.  193,  Xe)  19  separated 
ftnm  the  nucleus  lenitcularis  hy  the  j'nmt  Hnib  of  the  ext^rtml  ca))sii1e,  oimI 
|irhic)i  projects  into  the  lateral  vemriclt-,  in  called  the  tmrle"*  rtiiulaliM.  The 
ucleus  caudatUH  and  the  nucleun  It-ntunilaris  form  together  the  corpiin  ^iria- 
01 ;  the  farmer,  nince  it  projects  into  the  lattTid  ventricle,  being  the  part  of 
:  cor]>iifi  »1rtatum  tern  when  the  lateral  vtuiriolr  in  laid  oi)eu,  is  fumetlnief 
ikenof  as  the  intTa-veniricnlarporiinn  of  thi;  whole  body,  while  the  nucleus 
irularis,  which  is  whujlr  hJcld<-n  in  the  hennHplK'ni  and  in  no  part  prfjeclif 
to  tht-  talrrai  ventricle,  is  callH  the  extra- ventricular  portion. 
But  only  a  part,  indeed  only  n  relatively  r>roall  jiarl.  iil'  the  nucleus  cauda- 
|U»  it  difcloeed  in  such  a  horixnnial  wctinn ;  to  h-arn  the  ximewhat  peculiar 
D  and  relations  of  ihe  whole  nucleus  a  number  of  Mrlion*  of  *  hemls- 
taken  in  diHerctit  planes  mu>t  Im- gtudicd  :  and  then' will  nt  the  «arae 
I  explain  why  the  nurlcus  is  uiDcd  "  laudiitus.'*  Thete  t<«ch  u«  tliiit  the 
has  somewhat  the  f"rm  of  aooniniu  (Fig.  litii.  The  thick,  rounded 
i  fbnu  the  lateral  wall  of  the  front  pnrt  of  t\w  Inlcnil  ventricle ;  tbeoct 
body  passes  backward,  narrowing  rapidly  and  diverging  somewhat  later- 
ily ;  iu  its  course  it  archee  over  the  nucleus  Icnticiilsni.  curving  oo  much 
\il  the  end  of  the  tail,  sweef  ing  round  the  hinder  border  of  ibni  biidy  and 
iMiging  its  direction,  runs  eventually  ventral  to  it.  In  a  horiMnlul  i^ction 
ken  Hi  a  certain  depth,  such  as  that  represented  in  Fig.  ll);t,  only  a  portinn 
the  bead  or  hiuly  (,Vc)  in  the  front  part  of  the  figure,  and  a  truwvene 


7W) 


THE   BRAiy. 


•cc-tioii  of  the  end  of  tlio  luil  (.V<-)  in  ihf  Iilml  )>art  »r  tlie  fikiTe  are  Men ;  lU 
Ihv  interfiling  mrtion  of  tltc  iiuctcii*  lii»  iiUive  the  plaue  of  the  •Mios. 
Ill  n  irniitvcrao,  ili.< no  ventral  wi'tiim  tiik«n  »'iiui-whnl  niil^riorly  ihroufli  ihr 
frout  iimb  of  the  cnptiilo  (Fig.  I9')),  thc!  hrJiil  or  Ixily  i>f  the  u'ucleui  »u4i- 
(lis  t.Vr),  which  ha.*  not  yet  n-nchtil  iu  gn-nK^M  >litnpa«i<>u».  u  aecB  ]jiog 


Fta.  Ml 


ee 


eia 


M 


UuaiLuuuTir  optukc  or  *  Tujnna«  mMMO-VBCisiL  Aicidw  tiimi.'om  thi.  IIaud 
rauc  IMtnj  jir  «  LnBL  AmKwoK  to  no.  i>i.    lAniiiaiNaiDs.)    Kntuul  itj*. 
Jtf.  iluclcu(««litiu:  Up'.  'Jf>".  (lotiut  imUMoi,  via  bent  IB  two  Hsmoun.  •ml  II.  irimmT-t 
ItMltlU  ttuUcnUrb:  OT.  oiulc  (linlBinua.  ulUi  (w.  uiMTlur  uumiuwun>  ■■  cliim  nIMI 
kiturtor  Haiti  fit  iBicmA)  (niatiV,  4V.  dtcntikl  cajiial*;  4ip- npUl  Inict :  c<.  oiffHn  i 
tmix :  Ir.  a  (pMD  ihti  III  III  u|>|i*c  i«rt  brloaci  U>  tbt  iMenI  T«iiitet«.  In  In  inm  i 
nw  Rdd  of  nlKiaDliMU  UmmmM  |d«  aMn.  Ibe  •U*  Mdik  of  wMth,(D«>««*a*llfe4 
taraaOttibanU  ftam:  tUt  OM  vnM  OMti^aa  In  Uw  nuMniar  itoMaUoauitmBr 
At. ik« tenia:  /'.ftoaoklhtoi /'.■■rlMBllolir:  r-UrapsnlkilK.    RKKmicreiauiMnibtc 
PdimiMHr.  wUckbdutdodlBPIc.  t*l>.  Ii  in  ihb  flciuc  kfl  uiuluulod. 

(lonol  lo  the  nucleus  lenticularis,  »«paral«d  frum  it  by  die  whita  oiaM  ot  tbi 
fruut  liiub(ri<i)of  the  capsule, lhou;{h  this  a  Bumewlml  broken  U|»  hv»ir 


ot'^roy  iU4tler  puoaiuji  from  one  nucleus  to  the  other. 
Tejilnil  KctioD,  Mkeu  Mill  more  Mileriorly,  Ibrougl 


lu  a  tranavcrtt,  <1 
the  frodtol    lob*  I 


TUE   GKAV    MATTKtt. 


76; 


>  bwl  n(  llip  nucl«'UK  miiiliitut  i*  aeen  at  nbr>iit  iu  ((rMtttl  tixo,  nnd 
Jhhilig  iiiirktiii  lontN'ulnriii  i  XI).  n'pmiciili.-d  Uv  (lie  putamcii  ftloii«, 
ihg  (utH'il  wilh  it.  llir  Ino  tHifloi  lH-iii;|;  >M;|inrAtoii  by  n  *iaall  <|uiitility 
vkh*  tnntU-r  of  ihi'  iiiUimal  i-a|i«iilo,iinr|  t\v.u  Inrtcoly  lirokvii  up  l>r  bridlet 

rnr  nuutor,  giving  ri»o  In  ii  vtrinlc-il  niijiniMiiM'.  In  ii  similar  tvctiuD 
lurlhrr  r»r«»r<l.  tin-  iiuotcii^  Iriiticiiliiri*  n-uiilil  he  aWnl.  the  hciul  of 
iiueli-iiscnuilBtti- iii>iK!«iriii^  l>v  ilin-lf.  lU^Ciitiiiii^  In  l>i<-  liiii<li-r  juirt  ur 
lM.'iHUj>lii.'rc,  w«  6nA  in  ii  ilon>u-vci]trnl  wctioii  Uki-ii  thruugh  lli«  himl 

Pto-UB. 


CC 


-■-CI 


iKuniTir  fMTUJii  or  i  TBAirrrEMH;  DuNro-vtsnui.  iacttox  i»  Rmflr  Uuin>iik«ii  iViW) 

,  b«ad  cf  iHicttiw  OMMIMiB.  sBil  .VI,  iIh  Inuil  unit  of  ilta  (MUunia  irf  tlw  uuolciu  luuUfulAN* 
Blii#  fuad  «llk  II;  «•.  «or|w>  taBcanin,  oat  tli(««Ii  at  lU  hml  h«Dd  Or  rMiDm,  *a  tfau  bMk 
tl  tat  nM/nl  ivithiiu  Ira  dwHii-.  bowWD  IbaH  it  tana  thv  tnhnairlol*  <vcmniTlu  lb* 
tn  tUL-Minn  »t ;  (r.  kMcal  nniflcla ;  O,  clu«nua  i  f,  miniul  tota.  COcUial  gnijr  muMr,  •»  l« 
1*0.  left  uiwtuulwl. 

b  of  the  c«ijeule  (Pi>:.  11^4)  tbml  while  ibe  iiucleux  IcniiculAriii  U  horu  at 
treaUrdt  airs,  (he  tieit^  of  the  uud«iu  caudaiu*  (.V<*^  lyioK  dorvial  to  the 
leal  lentionlarib  uod  wjiianXfil  fhmi  it  by  a  ci>iui<lcriibTi.<  ihickn(«>  of 
irnal  caiiwile.  biu  lourh  diniiiiuhiM);  the  aamis  Kclion  laorvor^r  Hhiara, 
iral  to  the  iiiiL-leuH  Uiiiiruluru  nm)  clinging  to  the  dcsoendtng  honi  of  the 
ml  rentricle  i^l.r.ii.),  the  cxlrenw  tip  ofth^  tail  of  the  nucleut  catidnlui 
?»ioo«  about  tu  fb»o  with  Ihritnuill  miu«  ofgraymnuer  called  thsriKctu,* 
ftfl'tlir  (.Vrr).  A  UgEttal  (lOD^ilmliiial  cliimo-vt-ntnit  i  wdioii  taken  at 
ic  ilidiance  from  lb«  median  Inif  (Fig.  I!*7  ^  nh<m»  the  curved  c»uree  of 
largtr  imriiiKi  of  the  iitu'lni:*  rAii<liiiu>,  the  cxtrvma  head,  aa  well  as  the 
tr  |>art  of  ibi;  tail  lyiii^  >•«■[  ■<!*  (lie  pUiiir  i>f  llw  Mctian;  and  a  aimUar 


THE  VltAIX. 


MCtion  Ukeii  nonrcr  ilic  niidiJK'^  tine  (Fig.  200)  sIiowb  how  the  nudeui  b 
tbo  middle  portion  is  l)n>keii  up  by  bantu  of  fibres  of  the  iDiema]  oepnlt 
trnveraipg  it,  nnd  thuR  coiitrihiitiiig  ut  tlio  Mtriiilcd  anpeantnoe;  tlie  »mt 
fcction  nlM>  sliutrs  that  tho  globiii  lulliilus,  u  well  M  tne  puiwuen,  beiicaw 
con  tin  II 01 1«  with  lb«  iiiielcu«  cautUlus. 


Fill.  I9T. 


-^ 


.O 


vN) 


'^' 


o 


DucouimiTic  Onuira  or  a  Sujittil  aaamoi  takci  raMtca  n»  Riciit  MDinriiDi  >Xi* 
sun  mcoi  TH*  HoMi.  ^TRrjtiK.    'itnuuuiBTTOE'-i    Uolr  nuiuni  (i«. 
Tb«  pltiiv  or  the  nctlim  lannllnilriBCiKBl.  but  <1Ik>i>I]' If  I'ltnct.  .Vi-,  tbr  oaudatr  iiveliui  a>Mal 
lolfaclcnaf  ttic  lvIlen.VriDni«il]r1liiciitlmuiMrlure>lcDi,  i«(lBblori>ieI*lun  In  hr 
|«nof  llii«*Utim<i(*i>I,    II  tonmui  arch  ntcnrBWIUriiTrr  IIiir|nm]  niUKt  om,  tlwpiu 
■nd  Op,  the  (lolRW  i«llldui  or  ihc  lontlciilniniwleitfi  Xn.  Iliv  itnnilBlcild  nueleiw;  t1.  (L  <t,l 
Inunnl  («[*ulc ;  Oi.  ibcaDtorlurcuniiiiliviLn  ;  i  r  llm  Iilrirtm  tliiitl  nrWiiii  nf  lliii  hiImiIiiwi 
Oftlkal  -.  I:  ihi'  iKiluIat  iaW;  T.  Iliu  tviiiinrvl. 


Thus,  u'hvn  wc  sjniik  of  tlic  curpus  slrintuii)  its  »  wholo  wo  i»v«n  a  luge 
iiiiuH  of  gray  mutter  lyine  liil«nil  to  the  optic  iliiilnmiis,  rcacbtng  nesrlrM 
far  back  us  that  body  nnJ  strccohiiig  iiiucii  furtbcr  Ibrwanl,  as  far  forwaiilin 
fact  as  does  tho  latcnl  ventricle;  but  it  is  iiop<)rt«nl  to  rvn>riiibt>r  that  Uil 
divided  into  livo  massea  or  tiucln.  which  ari>  fused  togi-thrr.  and  that  in- 
perfcctly  at  the  very  front  only.     These  two  nuclei  are.  ihe  one  the  camna- 
sliaped  nucleus  cauaatus,  the  bulk  of  which  is  plaeed  Ibmard  projecting  int* 
the  lateral  ventricle,  and  whteti  on  the  whole  is  the  more  dorsal  portion  of 
tlie  whole  body,  the  other  tbe  irregularly  shaped  nuckus  leuliciitariti.  At 
bulk  of  which  is  pliiceil  further  hack  than  the  lateral  ventricle,  by  the  aiilt 
of  tbe  optic  thalaniii£,  and  which  on  the  whole  is  the  moie  ventral  ixirtioo  of 
the  whole  bodv.    It  is  no  lex^  imjxirlaut  lu  remember  that  tbe  radiatiiif;  l)hre^ 
which  we  calf  the  tuternal  capsule,  pats  in  tbe  hinder  revioa  of  the  wbala 
body  between  the  Uutlaiuuii  and  (he  nudeuH  lentieularia,  rorming  the  hind 
limb  of  the  capsule,  and  in  the  fhial  region  between  the  uucleiis  caudatu* 
ntid  tbe  uucleuit  laiticularu,  formiog  the  iVonl  limb  of  the  caneule.  the  froat 
and  liind  limbi  being  heut  na  each  other  so  au  to  form  an  angle,  the  so-oalltd 
koce. 


TUB    QKAV    MATTKK. 

rin.  IW. 


7mt 


<* 


ff."- 


itf^ 


i 


'f?^ 


Of- 


ai 


r**l 


^"5^ 


*. 


I 


Vm*  or  Muht  Htir  OF  BuiAiii  or  Uisi  *>  n»ciMMi  ar  *  Lwnim'DDUL  sicncni  ik  iiic  Uuman 
LnatiOKfraii  mi  LoHom-inHAL  Fiw-ku.    {AiiKiiaixiiTMi.)    lUI/  iiaiiiiml  iln, 

TlNto*,KtBMtna|liiiilIiu)icccloDM  0.  lUK*  lata  Uiciiuv  J>,  uul  IdIo  Itie  rrw  ontrf.  nbkh 
llilbCMlablk|B«l)rwnM>Mtld1ir«rB«  tnlo  Uio  hcnil>|ih«i«  •nd  )«■«* oiil  of  Iba  notion.  A  port 
«f  UN  Tcntml  Mirfluic  of  ttn  vrm  li  tfaown  In  Ui»  iiiiiM  ton  matkad  VX.  Ai  0/.  tliv  anirni  ranni 
•>r  iht  iftMl  coM  fa  n*n  oivnlnR  udi  lnu>  Um  /ohiU  oatnclf  (41b).  ararbnng  by  tho  taicbetlnin 
lUafHol  Id  lb*  mUUIv  tiiiiri.  kuil  innlas  oD  bf  tb*  afwrfvcr  tOHUb  tb*  poAHw,  9 P,  and  duenor. 
</■*.  r«rp«ni  tptadriariittita  Into  the  flUnl  rmMelr  (1).  Tbo  potttlor  osTpOi  qllBdl1(UIilMlill  ii  «aif 
(IvDOB  bdilnd  miiii  Uia  rairr  i)f  I  ir-ttim,  aiiiwiitil  to  UM  «ip«rfor  podaBola  Of  Uw  e*rrMlnin,  Mid 
■vcniDa  Umclntillaal  McUon  oTprbauclna  ilie  finnt  parlor  Iho  Ibunh  TanUlola  Tta  rorpoia^Ua<- 
(KHUaa  tt'""  ralallnlr  imall  brcauw  Uio  mcU&u  iiaiaw  Id  Uic  latdlaTi  line  in  ibo  dDina^im 
banrMffllkartibCanillvn  bodln'if  Uif  cmiialni  uid  [ininBlUiliiljr  In  tnrntiJ  tboin  la  Uiw  •ocaon 
uf  Ihanoriallr  iiIbcbI  i>(iiniliili»»f  f,  wbich  ororbaii^  tbc  opculng  of  ibe  itqiwduet  lato  Um  tblM 
twpfct*,  anil  UiB  ilulil  aim  ol  wlilch  niiinliin  In  ttit  bitaml  wall  of  Ibr  tUM  vtowlolo  la  allows  by 
aa  nnakated  iiBoL  Thanor  of  Ih*  tbIM  rtniclotc  It  hcd  lo  b*  (iratabad  bjr  Uw  «rc*i  «f  tht  JWbM 
f,  afcB»a  naaliaded  In  lon*ltniUnal  acvuon.  r«i«iDrlr  ibe  tody  oTIto  fetnts  paaai  )>!»  lte4lT«K- 
bi(  rtfbi  ^rtrtrn-jWItiir.  whina  ^liUuoM.  and  laluuu  vl»  uudn  tha  onrtiBngliii  roundadUod 
rod  or  ipimmm\$inottheearji»trmlloiu'n.  Inlhmi  rbv  bodj  of  Iba  Ibnili  l«  Man  |iaalii|  Jbat  behind 
Uia  ttafimn*  •canion  uf  Ibc  onlrrMr  fammlHun  .1  Inlo  tbudlTaistuKlfsl>liM'<rtiirv<W>r/.  whloh  la 
tMtintto««atltl>«(clif*1nilio  lnEn«linl1i:^lh*<xniHolplnvaidUia<wpaaia«>iHilIlkv*e*«MMiM 
M.  Tht  BMll  whllo  i-rma  Ituincillatrlv  taliliid  /  liidiau*  Uw  imlUoa  of  Ite  /liiaami  qf  ITava. 
Tb*  bii%tat  malliin  lurftas  of  Uw  ogiUf  rftiiUiiiiu.  »  r.  it  xen  fbnninf  lb*  laMial  wall  of  iba  bInMt 
(and,  oatlBii  la  Uw  eiaalal  Aami^  Uw  nuni  doml  i  ikh  of  Uw  ihlrl  vauUida.  and  on  tbla.  tulow 
llteaM)iarilwFla(al(VUid,l>a«tCOn*tiadod.  UxatcUonafUwaitllorwfiMlfenMilHnd  BM««Fn 
thr*  tOiBBl  (land  i^aiid  Um  *[iltfiluni  (J^jkwMi  Uwhinilandorjndrtaarof  Iholbaluiuui  |i[«jm<. 
tof  InMlbaaMAllad  imunne  dwunof  Ihcbialn.  thonn  ahadad  In  Uw  Biui*.  bf  which  (bo  |iu 

nwWi.  laaJiiiiilianiaUi  lliii  >i»laiiliM  cil  iifll Mliiiiwaiin  ilniii  llii  iiiii<*llinn.  |alaaaiiaw 

to  (ba  UiUd  taoblria.  Ui»  iwWoii  of  lb*  nhw  b*ti«*n<ni  bjr  lb*  iblii  bUak  Una  -^f-""!  (Kb 
thaii|il«iliBn  iDtlw  Ibrnli.  Tkr  franl  laad  moH!  ivalrali  |ian  of  (ho  Ihird  Tcnltlvlo  ta  aeni  tt>«ad 
Ui  Um  li^mUlHtlmm,  aiiulidd  lu  nUcli  U  (lie  iMMItry  btrlg  II,  «u  La  wcllun  *i  t  In  remit  of  ilio 
IslandlbdtnDittnnitbaopnfwmnrt  aonwat  UiaiyAcrfMawallnt  Oi>,MraIablaf  Ran  whkit  hi 
iM  aoiWrtM  WNnmtamn  U  Uw hMiaa  vrmiaofti.  MrMtMof  bM««MUw«atp«<*li»iiMosiic<n 
la  langllndtawl  anUon  irUb  a  NriaM  appaatanw.  and  auUnt  In  Omt  ai  Uw  nMMM  Jl  and  babind 
■I  llil»lrtWitnw  ;>i  ilniMltj  aiiil  lliii  ftiiiili  iiailiaflj  la  aarn  inriitwdtall  thii  afptaaa  birtilaw  Wf .  bw 
iftap^4af  panof  iMt  baabnnuuiavay  laetdulodlKlsaaUwrtfbt  laleiml  ranMtla.  tn  Uw  wall 
ct  labldi  la  aaao  Ihv  btilgtnc  aadtw  tmittaltu  .VC  Abnte  tb*  Ooti'iu  Callgenm  I*  aam  Uw  nM*bU 
•vAm  ot  tbe  dibt  banila(b«re  fentfnc  iba  rttthl  launl  vail  of  Uw  lonxtiuillnal  Ownn.  On  (hia 
aiailal  aofftM  appna  tminodklalj  ald>r«  iba  ceriwa  Mllsiuni  Uw  anbnl  (ijirM  AnalMtai  (;,/*., 
dallMdBbonbgrUMoJItav-aMrtKaaJjlHiiw/^w.  TbawboleollbcniMbcrwan In Uw fMoial F«0an 

49 


r68 


TBB   BRAIN. 


MctioD  ukcn  n«rer  llie  middle  lino  (Pig.  20O)  sbovra  how  ihc  mclnu  ii 
ilie  iDtildle  puTlMKi  in  l>n<ken  up  b^  buiu«  of  Glinis  of  tb«  io(«nia)  optV 
inivening  il,  nnd  ilius  <x>i)tributing  ta  th«  ilrlnted  anpcanueo;  ih-- 
aectioD  nim  ahows  that  the  globus  pullidua.  u  wdl  u  tb«  putanMi,  ^. 
contiDUMiB  wilb  l1i«  iiucleua  caadattie. 


m.tf9. 


0 


^Of 


O 


m 


MviiUMaATir  otmutM  or  i  Ajuiimi.  Sncnn'i  itiiiui  rnncita  ihk  Hiuin  ItuKwimn  <)i 
•OM  nam  tiik  UnOAL  tii-ari's.    ^MMuaixniw.)    llnlr  iui>iml  tlw. 
Th«|<l«i>eo'llH.-Malu»l>ne«Uul)ra^lu>I  Ihm  tttKhUrliirllari.   .Vp.lhxaiidMetiUclMic 
laUlOliAiK  UwlMI(nA>lnaMtlrlU*'lt>t*alil«t)or»tviil,toriRfciarilMI(>It«'*  i»  - 
[wltirUipaMOfMrviiani,   It  ftmuuiuohnf  (n;iM»«Bt«r  il»tm]  Batu 
Mddp.lbetli'ba*  laluduiofUie  taalkutojiivkiMj  AXiliii  MnjrsdBic*!  nil        -         'til 

MlM:  J>.ilwiarl(Mlobe:  r.ibeumpanl. 

ThiM,  wlwii  wo  spMik  of  tl>e  corpus  HtrijUiim  iw  it  wli»lu  we  Hi«iia  »  Urfs 
liiMB  of  gnir  m«IUr  tying  lateral  to  tlii<  ojitic  thiilniiin''.  r\-«cliiat:  ticarly  u 
fkr  hack  na  that  bod}-  and  atretdiiiig  much  furthrr  lirni  iin),  »«  Ihr  furwaKl  in 
fact  an  Aim*  tbe  lateral  v«ntricle :  but  it  is  impunant  to  remember  thai  it » 
divided  into  two  masea  or  nuclei,  which  aro  ftieed  together,  aw)  tbit  in- 
perfectly  nt  (ho  very  (Wtot  only.  The*e  two  nuclei  uro,  the  one  tliv  coiitin* 
shaped  nuclcii*  cauoatus.  t)i«  hulk  of  which  is  placed  forward  proitrcliiie  tnl" 
the  lateral  ventricle,  and  nbid)  un  the  whole  a  tbe  taore  doiml  {Hirlion  nf 
the  whole  body,  ibe  other  the  irregularly  shaped  niicleua  leulicuUro,  du 
bulk  of  which  is  placed  further  hiiek  clmn  the  lateral  veolricU,  hy  the  wl* 
of  the  optic  thalaniua,  aud  which  on  the  whole  is  the  more  vent  nil  [NirtiMiof 
tb«  ifboK  bodv.  It  iano  lene  im)>ortant  to  remember  that  the  rs'listiui;  libt«^ 
which  we  call  tbe  inleninl  capwile,  |iaaa  in  the  hinder  region  uf  ibi-  '  '~ 
IkmIv  between  the  tbalumu*  aw)  the  nucleus  lenticularU,  li-rnuTr.'  thr 
limff  of  the  cii]iaulr,  nnd  in  ibe  front  regioD  Iwiween  Ihi'  v.' 

iiud  thf  Mucleua  k-nticularif,  tonoiiig  tbe  ttoal  limb  of  the  cui  , 

iwd  hind  limU  Wing  bonl  od  each  oilier  ao  a»  to  form  an  angle.  tli<<  ti-eaS» 
knee. 


no 


THK    BRAIK. 


i  626.  The  uptic  tlialamua  lu  a  wbnle  U  s  soniewliat  ovul  nuus  of  ^^ 
inittter  lyiii);,  aa  wc  liav«  said,  nthwftrl  d»e  iltrer^itix  crus.  in  wliicb  tl  b 
|uinl_v  iiubeijded.  ItH  curved  iue<Uuii  Mile  ■■•ivereil  with  »  thm  Inyer  ofna- 
tml  gray  matler  foriuH  the  IniemI  wall  of  tho  (htnl  \-«ntncle  ( Fi^  193,  IH 
199),  mkI  in  n  loiifcituOiiml  verliciil  seclion  of  thu  liraiii  taken  id  Ote  lltw  'i 
tho  midille  af  the  t^ln)  ventricle  (Fi^.  1!)><,  O.T.)  »  hvii  iH'cupying  tbe  m» 
belnccii  the  formx  aiiil  hiii'l  imk)  (vple-iiiiim)  <if  tho  cin>u*  culoMn  mqit 
■tnd  t)ir  iliveri;itii;  itiim  below.  It*  man-  ur  !>»•  utraiglit  lateral  border  tbur 
on  the  internal  chimiiIo  (Pi>n.  19.S,  194,  19^).  Il»  ilmviil  Hurboe.  M  «•  hxu 
alreadv  nvn,  iiliut  furinj"  jmrt  of  thf  wall  of  tin;  thinl  vcntriolv  aiwl  bt  fnr: 
bnl  ibcri-  liw  clow  ubnvi'  il  the  |iri)|i>iii^t(iou  of  the  piii  mnu;r.  fomiiRg  tkr 
velum  iiHerpiwiliim  with  iia  cliorotd  plexii»  (5  fi()S).  which  crr«|»  in  owr  ii 
bcnontb  ihc  nrojvctine  liind  eiid  of  tho  coriius  cnllosuiB  aiid  tile  fbnii 
IFifi-  11*8).  It»  ventnil  aur&oe  is  fused  with  Inocnis;  indew),  the  t«^timiit 
or  <jor«aI  portion  of  tho  crus  ntajr  be  said  to  end  in  it  and  in  cortaiD  HnK- 
tures  IviiiK  vciitnti  lo  tbe  thalamus,  in  what  is  called  the  " mbtlialunic 
retail  '^  (Fig.  194),  while  the  6bnw  of  the  pes  jnas  firet  veutral  and  tlua 
lateral  lu  it  to  form  the  intornal  ca|>Bulc. 

Tbe  gray  inatt«r  of  tbe  whole  bodv  is  more  or  leas  dislinetly  divided  bt 
>heet«  of  white  matter,  as  seen  botli  id  bonMiital  aiid  in  vertical  lentiw 
iFi^.  li*'-i.  194,  1!>9),  into  three  parta  which  have  received  the  name  a( 
nuclei,  namely,  the 'pWum  or  ianer  nuofeiu  ( Fix-  194.ii(),i*hivh  with  the  thk 
layer  af  central  ^ray  matter  forms  the  side  wall  of  the  third  rentricle;  lb 
larjcer /'if«raf  riWoiM  (/7i\  which  abui«  u|M>n  the  internal  capaule;  aixltki 
nmnll  anitrior  nwnlotia  (Rti),  which  lies  on  the  dorul  aurfiioe  nf  tl>e  fnti 
jian  of  the  body,  and  which  thus  at  iu  tntnt  end  appean  to  proje^i  into  tW 
lateral  veiitrtule. 

ThcH-  three  nuclei  form,  however,  not  the  whole  of  the  optic  thalamus,  tral 
only  ibe  birger  front  portion ;  licbiiKl  ibem  11'^  the  important  |>orti(iii  calb^ 
the  pu/riiiiir.  into  which  the  hind  fxirt  ol  tlu-  meilian  nucleus  merpM ;  (his  ii 
partly  imlxvidod  in  the  crue  vontniUy,  and  in  tlic  hemisphere  laterally,  aal 
IS  )>artly  free,  coming  to  Uic  surface  beneath  tlie  hind  end  nf  the  corpui  <al- 
loeum.  Id  a  median  longitudinal  section  of  the  brain  (Fig.  19S)  it  is  tht 
pulvinar  which  Inrms  the  cushion-like  (hence  the  name)  end  of  the  thalann 
beneath  the  overhanging  eplenium  of  the  L'orpus  callosum,  by  the  nde  Df  tit 

Cineal  gland:  and  in  the  horizontal  view  (Fig.  193.  /Vr).  in  which  lb 
emlspheres  are  euppueed  to  have  been  removed,  tbe  same  pulviuar  it  mm 
frojectiuit  over  the  cms  by  the  side  of  the  anterior  corpus  quadrimninMi. 
be  buried  portion  of  tbe  puKnnar  is  eipiiaed  in  a  tnuMrerw  aecltoa  tatM 
through  the  anterior  c<>rpu«<  qiiadrigemiuuni  (Fig.  192) ;  the  extreoie  endtf 
tb'iK  pan  of  ibe  pulvinar  ( I'vt)  is  here  6txn  lyiuK  dorwil  and  lateral  lo  thr 
l>et  of  the  cms,  immediately  above  two  inoaMS  of  f^rajr  matter,  ihe  crrfx-n 
getiiciilata  ( Q/l.  C^ot.).  of  which  we  oball  speak  later  on.  Oni-  uf  tbeae.  thf 
Inlerat  corpuii  geuiculatum  C.g.L),  is  especially  ooaneoted  with  the  oplit 
Uuei  (o/t)'  oi'd,  lis  wesliall  me  hereafter,  tbe  pulvinar  iUelf  i-<  aUo  ctiniteolsd 
with  the  optic  trad,  and  'u  an  iui))ortant  |iart  nf  the  oootrat  appitratui  uf 
vision. 

S  030.  The  mibnUtiUUi  nit/nt,  Uv  re<l  nufUiu.  nwi  vthtr  p^^f  iimtter  of  &> 
ttgtiuMtum.    Nerve-cells  and  groups  of  Dtrvo-cdls,  or  snu  of  gnj  tnalier, 


■IcHMlB 


In  innt  ft  ttw  miiM>(M:ita»l  itani*,  irmiah  iJIrtiM  bjr  n«tim^  )•  calM  Ihs  margli 
inlhtmlMlepuiBtMlnaion»tior>ioCtbt  cetabml  MlalaDcr  bu  bna  nmovrt  Inordarlo  Am 
(tM  tMlHnn  of  III*  BrsinW  jbmt*  or  jiMUH  qf  Ililait4<i,/t..»nd  IninunUstrlr  Mow  IhlthMnaiM* 
01  PA.C.tbi^  punbvninii  i(i4i>I«.  Iii  ihaoanpltal  nvl<m.  J>K.0.1t  lli«f»i»n*A>iirtwaAiHtM«lr.MH 
C  Ilwfww,  irhllB  tl  O.L  timn  ■  p4rl  or  lUettntwU  Uibalt.  Tl.  ka  |«n  of  ih«  AV^Nf  I 
aedpOal  eantbiiUn.  Uie  (tMior  p«n  of  whlob  1*  lildilcin  to  vlai*  by  ibe  pM»  ■■■d  cnn 


THE    RRAV    UATTER. 


771 


lo  daicm  spwtial  nunm,  »rc  scnttored  throU);hutil  itie  legfiuMitiim 

'  il*  coiiTW.     But,  beaides  tfaf«o  ami  tb«  niicl«<i  or  lli^ltiinl  am)  fuurtli 

tl  atrvtt,  of  which  no  have  already  spoken,  certain  lar;;«r  ci^Ut^dioaa 

_  Kv  BtattM'  doBcrve  atlention,     A  conapicunus  maas  of  gny  niatler,  n\r- 

ilftr  in  iruntvcne  s«clion,  placeiH  in  die  ruidat  of  the  tegmentum  on  each 

de  but  fiomenhal  near  the  middle  line,  and  atretcbing  frAiD  the  hinder 

;in  uf  th«  third  venirii'le  heneaih  the  anterior  c»rpus  qinidriKeiniQiim 

lf>2.  I<J3),  is,  from  tlie  red  tint  il  poawma,  called  the  red  nuoletui, 

itt,  ur  locu4  ruber.    It  id  trttveraed  by  fibrea  of  the  thin)  nerve  as  thew 

ik«  their  way  ventrally  from  tlie  nucleua  to  tlie  surface. 

We  mu»t  ooutider  alao  oa  belonging  to  the  leicnientuni  a  largo  are*  of 

ay  matter,  aumewbat  lcD»-aha|)ed  in  nerliim  (Fik-  192,  Sn).  which  lie* 

twcen  the  pea  oiid  t(.-gmentu>n.  xharplj:  marking  olT  the  one  fr»m  Iho  olher. 

Da  it<  dark  Kp|itMtrani,v.  duv  U)  the  ahtiiidaiMe  of  black  pigment,  it  is 

thtr  tutulanti'i  nigra  or  lorxu  ni^r-r.     It  acquire*  iu  Ikmet  dimonsioni 

It  till-  mtddk-  iif  the  li^ngth  of  ttif  cruH.  cuming  to  no  004  in  front  (P<g> 

«)  mid  Jailing  nwny  bt-hind  (Fig.  191),  w  the  crus  pa«MS  beneath  the 

rior  corpora  tjuadrigeminii.     Th<«c  twn.  the  red  nucleus  und  thcxub- 

nigra,  are  porttapa  the  niuel  imporlnnt  wlk'ctions  of  gray  matter  in 

Qontum,  bul  wo  may  nild  tbnt  at  the  frant  of  the  crua  h  tbo  aiib- 

.  nigra  comes  to  an  end  there  ia  aeen  in  a  somcnhnt  rimilar  potition 

itral  to  the  liind  part  of  ihe  optic  thnlnmua  a  colloctioo  of  gray  matter 

Jl«d  thie  nrpiu  ntlAfuiiamietim  (Fig.  194,  t'.ib). 

At  the  hinder  part  of  the  crtia,  ae  it  ia  about  lo  plunge  into  the  pona,  while 
ba  pee,  now  decreasing  relativelv  in  aize, still  continues  to  be  ordinary  white 
■composed  uf  longitudinal  bundles  of  medulUted  fibrea,  the  tegmentum 
iktt  no  more  and  more  the  structure  which  in  apeak! D;f  of  the  bulb  we 
illed  reticular  formation,  and  which, »:•  wo  aan,  d«wrvei  to  be  coiuiderei)  as 
.  kiod  of  gray  matt«r. 
Jftc  yray  mattfr  0/  Ow  poiu.     When  tbo  conjoinod  crura  as  wo  trace  them 
vani  plungn  iM-iiojitli  the  ponw,  the  longitudinal  fibrvs  of  thr  i)os  of  each 
in,  nf  wr^  have  said,  aooii  split  up  into  bundlw  niid  i>cntt«.-rcxl  among  the 
verM  fibres  bciouging  to  tho  poiks  itaelf.     Dorcal  lo  this  splcni  of  irana- 
I  and  longitudinal  fibre*  formuig  the  poos  proper,  botween  it  on  tbo  vea- 
jrfiwe  abd  the  centra)  gray  matter  with  tbo  pnst«rior  corpora  quadri- 
CD  the  doml  mriiM«,  is  n  region  which  may  be  called  u^^cntal. 
t  it  is  a  cnntimialion  of  the  tegmentum  of  the  cniA.     In  the  front  part  of 
I  poo*  (Fig.  191),  where  the  posterior  corpora  numlrigemina  «till  form  the 
tina]  roof  of  tlie  section,  this  tegmental  area,  wnidi  ia  much  broken  u]>  by 
I  atranda  of  longitudinal  ftbros,  of  which  we  shall  apeak  later  on,  oontaios 
*  nerve-celb,  and  ii  largely  composed  of  reticular  furiaation.     In  this 
I  on  each  side  agnnipof  nerre-cells,  tii«  lotvt  raritleiulVig.  lill.JLc), 
thivh  we  have  alniadv  referred  (§  622)  aa  probably  serving  in  part  aa 
[thaori^n  of  the  dcncendiiig  root  of  the  fifth  nerre  (V.<f.).  iust  ventral  to 
rhidt  it  linL    Thin  nojuirea  laiver  dimvosioiu  further  back,  in  the  front 
, of  ibi' fourth  vcnlrtdc  (Fig.  193,  Le.)  lietwc^u  the  levels  repreiented  in 
190  and    191,  and  ix  a  collection  of  large  spiudle-nhapcd  nerve-cetla;  il 
bluish  tint  when  itj>  bhiclc  pgnicnt  is  Mon  shLniag  through  the  sur- 
Bg  more  or  lew  tmn^iKircnt  material,  hence  the  name. 
Um  hinder  pnrf  of  ih«  pnnx  (Figa.  189, 190),  where  the  cerebellum  is 
^orerhanging  the  open  fourth  ventridei  the  reticular  fonaatioo  of  the 
Dtal  area  is  still  more  conspicaoos.    The  only  special  collection  of 
^aoatler  in  this  region  to  which  we  need  call  attention  i>  one  which,  con* 
f,  like  ibeolivary  body  of  the  bulb  (or  inferior  olive),  of  a  wall  of  gray 


772 


THE    U1tAl>'. 


niBltcr  Eurroundiiig  and  Burraunded  bv  while  mailer,  is  rallei)  thtl^fpiri 
(F^  IKll,  l»U.  *.«.)■ 

Toe  veDtraJ  fiarl  of  the  pone,  nrllie  pons  pr<i):er.niilike  ilte  pesortbecni: 
coiiiaioH,  niix«(I  with  the  flbree,  a  verv  cuDsidtrable  quantity  ofgnr  mtiifr 
Tliia  is  fairlv  almmlaui  in  the  from  part  of  ihe  jxina  i  Vig.  191 )  Wo«  li, 
corpora  quailrigemiiin.  hut  increafefl  even  more  behind  this  *  Firb.  1«I>,  JMh 
Heucc.  UKiugh  Ihr  ponn  proper  is  largely  built  up  of  traiiiiverec  and  iMuiiu 
diiinl  fibre*,  niid  iboiifih  it  coiilainH  no  comijact  H;^ri'^Blioi»  of  ^raj  autltr 
rc(t'iving  ii|jei;iHl  DBiues,  it  due*  contaiu  Hialtered  ihriMigbout  it  t  very  lirp 
i|iiaiitity  (it'gruy  mailer,  far  more,  indeed,  lliuii  w  pr<-«rnt  in  ibe  t^jTaenul 
|Hirtion  :  the  gniy  matter  of  the  pon* — thul  U,  of  tlie  jioiu  proper — ibuii  k 
n'gardeil  an  fiirintnu:  ii  very  iinixirlniil  part  nf  the  gray  matter  of  tbi-  crnni 
mtrni,  ami  nf  no  litlle  phy«<jlpgicul  wgjiificancc. 

Dchiiid  the  pons  the  ernral  vycleni  is  continued  into  the  bulb,  «ith  'hen 
etructuro  no  h&vc  ulrcndy  dealt. 

4.    Otfirr  CttlUttiont  of  (!nty  .Vatler. 

$  631.  Of  tbese,  three  descn-e  cliiel'utt«Dtion,aDd  may  lie  cltuMtl  ta|{«ll)n, 
tboiiKli  they  differ  in  nature. 

7'fte  gray  mattfr  of  the  airpoui  ijtiadrigrmina.  On  cidi  M«le  of  anil  Mn* 
what  dorval  to  tbe  eenlral  gray  matter  of  the  aqueduct  which,  a>  we  limr 
•ceil,  is  well  developed,  etpecially  on  the  ventral  «ide,  cnlleciionfi  nf  ^i 
BUtller  form  ilie  chief  part  of  tbe  corpora  ijuodrigemina,  both  anteric>i  Mil 
pcaterior. 

Th«  gimy  matter  of  Ihe  nnierior  corpora  quBdricen><'>*  (I^'Jt-  '^i  •*■  V-  •• 
»  more  ditlinclly  marked  nff  friim.  and  MpnmtwTby,  a  uider  tract  cif  wfciif 
mailer  from  tbe  central  giBy  mailer  of  llie  utfueduct  llian  is  ibal  ofilir  p> 
lerior  corpora  quudrigeminn  i  Fie.  192,  "J''/)  :  it  it.  moreover,  of  a  <)ilfmii 
nature.  Indeed  the  tuo  pairs  ot  bodies  have  quite  diHereai  relalioDf, art  iJ 
diflerent  nature,  and  perform  dillerent  functiona. 

fiwyjdryi  ffenicvhilfi.     The  two  oplif  nervea,  an  we  shall  aee  in  detail  l»t« 
on.  give  riae.  ihmugh  the  optic  decuMiulion,  to  the  two  optic  trnela.     ([arit 
optic  tract  (Fikul  IS'J,  lir*.  0;i),  wiiida  ruunda  the  criia  cerebri  on  ii-  Teainl 
nurfece  to  reach  the  vubxlame  uf  the  beiniaphere  in  the  region  Mxatk 
opiic  thulamua,  and  »■  it  doea  au  ia  described  aa  dividing  into  n  Inleral  in' 
metlian  portion.     The  lateral  portiou  juat  a*  it  «nei'|)<i  round  the  far  nip, 
that  ia  ine  initer  or  laternl  edge,  of  tbe  crua  l9rar*  a  mun<led  awcUlnir '  P.- 
146,  R  and  C,  C.ffl.}  the  lateral  or  onttr  eorjiii*  t/mifvlalmK,  (he  lui  ■■ 
wfaicb  confiNlH  largely  of  gray  matter  (Fig.  I!>'2,  Cgf)-     Tbe  median  i 
fimilnrly  beam  unottier  like  twelling  orr-upying  a  more  median  piwi- 
mrdi'in  or  innrr  eorpu*  grnirnlalum  i^^Fig.  18*1,  A  and  K,  Cm),  iJie  initr>c 
of  which  (Fig.  11*2,  Cytn)  ii1h>  concists  of  gray  ninticr.     It  ■*  to  hengntBal 
that  tbece  two  bodies  should  bear  the  nme  nume,  for  tbcv  nrv  diffimii  a 
tbeir  origin,  in  their  conneclinns,  and  in  their  InnctKHM.    Yhe  luli-ral  l>*N 
is  nid  to  be  derived  from  the  fore-braiD.  that  is  from  the  vesicle  of  lli«  ikini 
ventricle,  hae  definite  conDcctioita  with  tbe  reiiniil  optic  tibre«,  and  i*  dii 
tlnetly  concerned  in  vision  -,  ihc  median  body  is  derivol  trom  ihe  miiMifvi' 
ia  Dot  definitely  cDnnecUd  «ilh  the  retinal  fibres,  and  ap|>enrs  to  bo  ta  oi 
way  ccncemed  in  TiaioD.    We  »ball,  howtter.  return  later  on  to  the  conixe- 
lions  and  probable  functiona  of  llie«e  bodies. 

f'nrjrtio  dnita(vm  if  ihf  etrtinltuw.  Id  tbe  midal  of  llie  »■»  of  ■1* 
mailer  which  ia  formed  in  lite  interior  of  the  cerebellum  by  the  coDtMU* 
of  llie  three  piduncle*,  is  ioiind  iFii;.  \^9,  CD)  an  area  of  cray  MliO' 
iirraDgei),  like  the  olivary  budy  of  the  bulb,  an  a  sharply  (bided  ur  |il*il(^ 


THg    GItAV    MATTEK. 

rio.  tm 


rT8 


OVTUn  or  DeiMUSTiL  ScmuH  of  liku^  v>  now  tub  Ifrnumn,  <'tr*i'u.    MunlMM. 

I  te  Mkan  M  a  Inol  mni«  Tnutnl  lliUi  iliowiiin  >^  m  Tliii«ntr  uiaUwof  (baracUs 
■mUlanaiukailei.biit  ibMOf  itao)[|iiu*irlBiuuiaa'l«|iU«ib>Uiiiiii  li  ihaded  ;  or, 
«itila<l«IIMiM.>ti0irtiitUi«  axUao.  LOBBl.AUd  aauilar  iiuctul ;  .ViL  iiucleiw  knUcularlt,  akvir- 
H«  t*cpatiBaataJ|CkaB4»irln<i«r4lTMei>Of  (IU(labut  fvllldin  rtrr  •mall :  XC.  nocteiB  «»u- 
.Ikakifvbaad  tafroalof.  auillliaitliDtalihliiitall  tMhIa<l.tIi«lhalaiuu>;  O,  ih*  knee  uT  Ifet 
.  mini"<|>("ta-'JNf."nutf (tafodUoaaftfeipgronil'tBltnetaaaiiilMtaiMd 
Ita  «m»»l  bun*  iBdIcale  tmadlr  th*  niaun  pmMmu  dT  ik«  Mtwal  coiMdMaiUa  <rf  ih«  una, 
iMMd  ae«nrdl«c  lo  Ihs  wavuiuMi  wllb  wWcb  UOTal*  awwniBd :  Uiui  Ar.  iDo^aMcMb  o(  Iki 
*T«t.  JM.  <4  ibc  bead ;  Ik.oritwlonco*:  ••tt.uriWnuulb.SW.arilwAaalilar;  A,«#tlM«)!bnri 
P^ at itw hauil :  .tM.uriboalilaa«n:  Hi^vltiir  hip:  jTa.  of  iba  hate:  Mftof  lkafca(i4llto 
iBai<0ni-n<vl|>tal  imt :  vc,  Staw  to  lb*  iiralrlHl  tota :  <%■■  vfU"  nllatioa  Ai  iMi  lavcl  (h*  Hint 
a  th^ltvaui  Mt^laUianiW'Uinbnr  tiMMpMtolMhiMlof  ttenrauiUal  tneu  nw aloM*  katl- 
MBMltl'.  ^Wllrl  irtth  Uig  iiUm  <ir  lbs  koUiM.  CC  Tlf.  M.  /Vaa.  <«.  tlu  nMniH  of  U«  rarpiw 
(•ltaNn,'MllWif«nli*'<'<h«winr  both «IU MtO*  barlBMMallr.    Th* tlOtkdark  lint  liiillciaM* 

i>a  WwiiilaiJ  nr  ibiiiaiHI (  Un •itMioranl  4«n«iiUiii  kcrw  o4  ibo  bu«tal  nuiral  and  or  im 

Ife*  tttM  nnUlotab  (lia  lw«  T«alil«l«*  Mac  U4  Dtwi  lilo  onn  br  tiM  rvmotal  or  (ho  nliim  aiiil  cliu- 
WM  H"***  ***-  'n«DtaloiMlinal>lb(B>FB'pai1a<tbUniirUTl»>llaam  tkcfonili.  Ul*nl  lotlic 
nadaii*  l»lUlraUi1>  l>  ■««  is  omMim  Ikt  clauiLram.  Itw  mrwi  sf  ilio  liUa4  <rf  MM  ao-I  Ihr  npot- 
fala«atM«««lilUanontUn''<t*MW*n1 0(11*11  fli  ln»rl>4  lutteir  irkloh  !•  lbahlii<l-(«rl 
MtteMMo*. 


^ 


774 


THB    BRAIN. 


band  in  (he  shape  ul'  a  Ratit  or  boit\.  An  In  tbv  HiniilMrr  uliTanr  tiodt  tbt 
gniv  tualler  of  itie  flank  i*  cuveml  up  by  and  il*  iDi«riur  nllcd  up  with  *liil« 
niaUcr;  the  uoutli  of  tli«  Haik  ii  on  each  niilf,  dim!t<<<)  lownrt)  Ihe  mf^lui 
line ;  the  fibres  paw  cbii-ftv  to  tbe  ttiporior  ]H-i)iiDctt'. 

Thent  are  ul»n  othut  itilWlioiu  ofsniy  miiirer  in  ihv  ci-4)tnil  uliitv  nalttr 
(jf  the  ctTtbclliini,  Din^  iif  which,  ciillcu  ificniiclciunf  tlir  njof."  iiCooaecierl 
with  ibi-  two  iiifi-rior  |xtliinFl<». 


THE  AMUmEXEMT  OF  THE   rUIRES   OF  TDK   URAIS- 

{  63S.  The  systeiDB.  Iracte,  and  btiodlce  of  fibres  m  H'hich  the  white  imtttt 
of  the  brain  is  arran^d,  may  be  distiDKtiiahed  from  each  other,  partly  ibniugii 
mere  inechauieal  separation  by  Dteaos  of  llie  n:B)|>el,  partly  by  l*eiD^  incri 
out  with  the  help  of  the  microacupe,  but,  as  m  the  9j>inHl  i-nrd,  miu'li  nion 
fblly  and  completely  by  diil^rences  of  (fev«lopo>eiil,  aitd  by  thci  nieihM  '^ 
(legrneralion. 


')C 


UCTUVS  or  1  9imnAt  Sbcvmoi  tii»ol'iih  tak  Ummnimm—ittx.    itstaaiKiHH  > 

Tlwustilnii  lj  uktu  not  far  tollwrlchlor  (Iid  moillui  pluMMnd  lnanc-lMlf  UlMarur  infuwl  — 
TheKiai  mitilvc  o(lIie  uurpiu  ■Irlaluiu  HiirJ  Italamu*  U  tlMd*!  .V<%  ^.  Uw  caodM*  nmt^K.  ^ 
ltepu(Mn(n,»iul  i^.tlw|lai'i»i»iil'liuor(lieleiiilca1ttfaiKil«u«:  or.  iliiiu|iUc  iliMluna:  C3.iw 
InHmal  oianlt  wltli  a  ilraatol  ■I'l'snuutn  nnallnf  aiiprajilmMd)!  Ibu  illfvrUon  lmt*n  kf  "*' 
biwtH*  pHUot  tfiM  It  from  ihu  i»nlon  nt  ttitmit  ntdlua  orar  U.  la  >hMn  wn  nf  hun*!*  ■■>  ^ 
bfcaitlTill**laCIilil>edabwiMtij-slna,yroa,ap]r'*'><l4*llJM«in,  P rOMllattTlMht* tola mitel n**- > 
tn<lil*>  ttraaU,  4un»liiinl>t>  iihn.  (uh  >,  tnil  Imatenaoiil  ila*.  mc.)  mn*.  ami  ■  '>«|—> 
dfMal  ifaMni.  •m- :  lb*  tlimiliin  ^r  thr  tmn  of  tba  intMwit  o4|niil*  l«  IndleaM  br  f -  (X.  <■* 
«Tiuetrtbt1:0b  llici»<allad-ipuv  rw1Uiic>iu]MHliizInlotti«(i«clH>*l  ■■>t»i  rv.  tbt  >9faiil*.~m)>' 
■ha  C0Tt*i>  talluuiu;  r,  >.  r.  llH-liilafal  mUrlQlt  cut  acfnai  iii  l>in«  iliITurani  t4a.-- 
Hiiliaiilin   II     f'li   Hill  inHliilnliT  III  iii«  aiilliiii     nutofltietvivl-'lUiiBltami  i  .      . 

rtfbi. 

We  linve  »eeii  that  a  o>arlcei)  feature  of  (lie  hniiii  i^  Difttendil  \>\  " 
crura  cerebri  wbicb,  iiiniiiii^  forward  from  ibe  hiud-parix  of  tii 
spread  out  into  eacb  r^rohral  hemiaphere.     We  bare  alau  ;«i-n  tliat  i  >'  ' 
in  the  wiiU:  twti»c  of  tb«  nonl   conaiaia  of  lvi>  parlK,  a  dunMil   part,  i>. 
Dieiiluin,  and  u  v<:Dlral  part,  ihit  iim  or  rruKln,  ami  that  tlimv  two  iMri* 
very  stiikiitgly  fWtin  ea«h  <rlhor  in  HlriicliirL*  and  in  rvlations.     Titr  |*- 
mt£  cxctuMvHy  of  bundlts  of  longiimtiiinl  libm,  and  wv  may  Ini  ' 
from  the  cerebral  hemiupbenv  iiilu  tli«  tioiii<  and  aoinv  of  ihem  hvyi 
pons  into  tbe  bulb  and  Kpiiml  oortt,     Tnv  Itftnii-iiiiin)  in  more  niini' 
Btrvciure:  it  cviiaula  of  gray  matter,  and  of  tibnn  and  biiodleB  "( 


d<&r 


I.ON'ClTL'tHSAL   FIBRES    OP  TBK   PIUAL  8TSTKU.      775 


luivini;  various  relntiouB,  bolh  wilh  die  oilcoiiom  of  gray  mutter  Ivitii;  uitliin 
iuelf  and  wilh  aurroundio^  ittnictur».  Il  too  has  connections  with  the  parta 
lyipg  in  front  of  it,  and  with  the  parts  lyinj;  behind  it;  we  may  trace  it  too 
^M^kwan)  throufcb  the  pons  into  the  bulband  forward  to  the  optic  thslamus. 
If  we  allow  ourselves  to  oonoeive  of  the  optic  thaliunua  aa  constituting  the 
froui  ending  of  the  tegmentum,  we  ma}'  arrange  a  large  part  of  the  brain 
Into  (wo  main  regions,  into  h  tegmental  re):ion  stretching  from  the  optic 
Uialaniu*  through  the  donial  nortion  of  the  pons  to  the  donnl  portion  of  the 
bulh, ami  into  a  re;;i<>ii.  which  we  ma)-  <-all  the  |>edal  regKMi,  stretching  from 
ibe  intrrnitl  c>intiu)»  through  tht^  venlnti  |nriioD  of  the  pona  to  (be  ventral 
jKirtion  iifthe  oiilb. 

Tlir  Hhn»  of  thp  hmin.  iis  ii  whoK'.  iniiy  Ih.-  hmodly  rlii^itu'd  into  longl- 
liidinal  tmcts  mnnertinf;;  piirt.i  of  the  hriiin  with  )iijcyH-i:din){  |Birt.-<  nml  Into 
ITOIM  or  oummiwurnl  Iriu-tii  hi-twiTn  ••"v  lutt^nil  hulf  Mnd  the  olhi^r,  bikI 

iio  tncta  vonnecU'<l  with  the  ^^vrnil  [-ranial  nrrvi-t>.     Talcing  the  loiigitu* 

inal  fihriw  fiml  wtr  may  in  BcciirdiuKv  wilh  the  division  junl  explained  into 

,E  petal  and  a  tegmental  region,  coiiiiidcr  ihiM^  iw  forming  on  the  one  band 

pednl.  and  on  the  other  hnod  n  tegmental  K)-»tcm. 

Both  Nystcms  begin,  us  we  xhall  we.  in  the  cortex  of  the  eerrhrnl  htmU 

ihena,     Wc  shall  linve  to  deal  with  the  tv^cmphy  of  the  cortex  later  on. 

t  nay  hero  say  thnt  the  tin>t  broad  diri»ion  of  the  whole  eiirfiice  uf  a 
bemtaphen ie into  four  mnin  regions;  frontal, parietal. occipital, and  temporal 
(Piga.  194.  195,  m»>- 


i«x<irrt'i>ii>Ai.  FitiRB)  or  tuk  pbdal  Hvsrreu. 

S  633.  7'A<-  piiraiHidal  fr<ai.  We  bare  already  (fi  S7fi)  said  that  ihe 
atdal  tract  of  the  spinal  eiird  may  he  traced  to  a  particular  >«£'<■»  of 
be  cerebral  cortex,  ^^e  Hhall  study  the  d<rtaiU  of  this  region,  it'll ich  ia 
often  spoken  of  &.i  tite  "  motnr  nrra  "  later  on.  but  miiy  here  nay  tluit  liniadly 
apeakinc  il  is  ixirii-tat  in  jinaition  and  cor  res  {Hinds  Ut  the  partu  of  tbe  cortex 
giathered  rixitid  the  tiwiurt-  uf  Hultiud".  Fibrm  piu»ing  from  the  gray  matter 
iOf  the  (^>rtex  of  ihU  n^gion  to  the  white  mattrj-  Iwlow.  and  »i  eontrihuting 
lieir  share  to  thu  central  wliiti^  matter  of  iho  henii.iphere,  convert  (^Ig*- 
~l),  '201)  to  form  part  of  the  internal  cxponile,  namely,  thnt  part  which  bi  a 
nn»iiilnl  aection  {Pig-  109,  Eyr  to  Ply)  oceupic*  the  kne«-  and  strvtchea  fur 
acre  than  half,  or  itcarly  two-thirds,  along  the  hind-liuib  of  the  cnpnilv, 
tftten  the  optic  ihalaniiis  on  the  inside  niid  the  nuchrus  IcniictilariM  on  the 
^Utaidc.  From  Ihe  knee  and  liind-limb  of  the  capaiilc  they  paa«  by  the  side 
if  and  ventral  to  the  optic  ihntiimiis  <;  Pig.  I'M,  'JOl ),  and  so  contribute  to 
'fenn  the  U-(;;inniiig  of  the  cms  cerebri.  In  thus  copverging  to  take  up  their 
Hitiud  in  the  ra]«iilc  and  in  (heir  further  panaga  to  tae  cnu  the  fibna 
h>w  a  course  of  somewhat  complicated  CTirvatnre,  Aa  we  trace  the  cup- 
nilr  from  more  dorwil  to  more  ventral  levels,  wc  liiid  it  CODtiuuttllv  changing 
form  1  the  exact  shape  of  the  rfl|«ule  shown  in  Fig.  100  only  holds  good 
Kir  the  level  at  which  the  section  wa^  taken:  it  difl'ers  somewhat  from  thai 
'II  in  Fig.  llftl  taken  at  a  sliKhtiy  different  level,  and  sections  still  more 
il  or  still  more  ventral  wixild  present  still  greater  differences.  When 
examine  a  series  of  Iiorizonl.-il  sections,  taken  in  sticeeasion  from  the 
dorsal  to  the  ventral  regions,  we  lind  that  the  knee  shiAs  ita  poeittOQ  and 
bangea  in  the  width  of  its  angle,  that  the  two  linihs  vary  in  direction  iu 
!  and  in  sliape,  and  that  at  la^t  the  bent,  flattened  capsule  pafaee  into  the 
re  or  leea  nwndetl  erus  hy  the  rapid  diMppearauce  of  tl>e  fore-liiub,  and 
oonaequent  extinction  of  tl>e  angle;  so  that  in  one  m-owe  it  ia  tlie  hind* 


OvruKI  m  *  TK^ttvian  Uohm-tdctkii,  Sbcdon  or  iuk  Ridht  U4Lr  or  tuk  Diatx. 
(KklanU  dai)    (SonjUMania.i 
TI>aaNQoniihlaliUlak*n*t  Uir  ltr«l  of  Iti*  kna*  or  ilw  ratwilw.  ami  1*  tlwntat*  hik 
bMWOTn  Pki«d  aiKiini  111  Fl^  IH  knd  i^*!.  U  luuvdnaed  is  iliiuimis  iiw  rouiw  <if  iim«im«Iium»^ 

the  pynmlilitl  tnU,  0  T,  Ojrtiv  llulnniiu .  St.  Baoleiu  iitu<l>tiu— Ui*  bout  tatly  mpfttn  IB  tm 
•crtlon:  n.  imlniDi:)! :  tip".  (^'.  Divtio  ram  of  llii.'(liibnt  palUrliwoT  Iha  luettil*  iMMImUria  <' 
llw  clauflr.au.  i~£,  ibu  uimtuI  i:a|aiilB:  Iii,  llio  lilaiwl  of  IMI:  ca.  ilia  aiiUrbv'i 
•bwM  l»  midpt  II  dlUlnol  ■iid  Hip  nbi<<i  fincn  Uio  l«m|>Dn>4pbi>niilJal  Inbr  wlikk  («■  |gV>  It  Mn 
Illdk*k4  br  brakes  llnca:  Op.  lbs  ofiilc  Inct:  Inl.  the  radot  Ihs  dMruiidliiit  bum  ottlM  tatn< 
niilrlct*'.  F,  Ibt  Ibmli:  /*.  ib«  nid  uf  ibu  aniHlnr  iilllsr of  iha foriiii  in  ibr  (■••of  ilwiMlwHi 
(  f,  oupw  oallotum ;  (l  r.  anivrlor  [«it  of  iha  o-K<i'iial  1-itw  /<■  !•  ibt  rvntml  BwK  or  ikaan  c 
RoluidiX  Tin  fouoa  of  the  Dbiwof  ihc  vynmuiliil  imi-i  ivmnopt*!  ninniRl)- irllb  ■••-  ■-.■■>  i<t. 
add  ami  and  bnuMvIlh  t|<Inal  iiemmanituf  tliiH4tDniii>rCivl  with  tUs  (iMali4  hrn'  ".tl 

Mrnn,  I*  tnuiirn  br  brokoD  Uncfc  TtiHvanallnMMiiTcrfiiitt  ibiothrlaicmalaai-  tidi 

lllimitbouM  In  rDipK*  uili*  Dy.inaot  ibn*  DhnalneaiiiiiarBl  wHb  ibc  burtuiiial  •wiiii«  iluwa 
In  tit-  IWiDd  Ui«acltlal  finurt  ibnim  In  flE.  Vn.    fflBdlOUtillia  ttumt  nt 'Ibt  iiuni  aatethit  ut 
4aml  |an  ot  Uio  wmfioKhocdiiliBl  Racl     Tlw  fliu  diMMt  llDoi  «aiiTpr|iaR  In  ilw  cTWfM*  '• 
r  r,  Indlnta  lb«  roUiM  nf  [h«  csUoial  llhiT^ 

14  gbvioui  that  the  flUroi  of  Ui«  i>yranI<Jiil  tract,  lik«  tliv  othvr  Sbrw  uf  lli« 
capaule^  are  eoniinuHlIf  eh«agiii){  ibcnr  directioD  u  lli«r  pan  ihmngl)  itie 


I 


I 


I 


Moreover. «  bile  ibe  fibres  tnm  diflereot  purld  of  the  "  motor  ares  " 
.  defloite  |MiHitti>ur  in  relatioo  to  each  irtber  %s  they  [xua  inio  the 

apanle,  their  rebUire  pomtioiM  are  nol  cooalant,  but  varr  soroewbat.  To 
ihn  point,  however,  we  shall  retura  wheii  we  dime  to  apeak  of  the  fuuciiofl 
of  thia  tnet. 

In  the  crut  thcM  fibre*  rua  excluDively  In  the  |ks  aiid  fonn  a  compact 
■mnd  (Fig.  192,  I'll),  (iron  I  lying  tlie  c«ntral  ami  Inrgpr  portioD  of  the  pest 
betWMO  a  HQuill  DittliaD  )M>rtton  ou  the  Uii«t<le  aiid  a  lateral  portion  on  the 
OUUMc  Maiulaiiiiiig  l.hix  jXMiiliun  aUmg  tliv  cru*  th«y  entrr  tlic  p<iiu,  Iwl 
Iwn  tb«  (mviouiily  coiiipiurl  Ntrnti<l  i*  K]>Tit  iili,  by  tlie  iiitorlneing  traii»A-«no 
ibrm  of  tho  pon«,  into  a  immbcr  of  McatIon.-il  luiiKllm,  wliii;)i,  huvtcv-cr.  n»  a 
wbok.  Mill  kec^  th«ir  cviitntl  (weilioii.  Th«y  f»rin  thn  greater  part  of.  but 
not  all.  the  butidlM  aocii  cut  tntievenely  in  tmoavonw  aooliofw  wf  the  pons 
(Fin.  ID<i,  11^1).  Further  barkwani  thev  bcci)m«'  the  pyramid  of  the  bulb, 
ukTm)  give  riM  in  the  spinal  conl  lo  the  dirccl  ami  onwscil  pyramidal  tract*. 
TbtM  tibm  &OID  ihe  motor  area  of  tht;  cortex  of  the  oorebrnm  are  thus  tbi- 
■oorM  of  the  pyramidal  tracts  of  tho  spinal  cord,  and  hence  the  wliole 
straiMl  of  (ibm  frum  ibe  cortei  dowDvard  has  been  called  the  pyramidal 
tract.  We  have  said  (§  5713)  that  ne  have  reafions  for  thinkioK  that  the 
pyramidal  tract  in  the  spinal  coni  make*  oonnectious  through  the  gnj 
inatier  of  the  anterior  born  with  the  anterior  roots  of  all  the  Spinal  nervei 
in  succeadon;  and  nmilarly  ve  have  reason  to  think  ihiit  along  ita  oouree  in 
the  crus.  in  tbe  pons,  and  in  the  bulb,  before  it  reaches  the  oord.  the  tract 
also  niakea  connectionti  with  the  nuclei  of  thoae  cranial  nervea  which  are 
motor  in  fbiietJon.  During  tbe  ]>a«Hige  of  the  tract  thmiigh  llie  iuteroal 
capeule  the  DhreH  dentineit  for  cranial  nuclei  occupy  the  knee,  while  thoae 
belaogiBg  to  the  npiuul  eun)  run  in  the  hiiid-limh.  Some  authora  limit  the 
tam  pymmidal  Iract  to  the  spinal  moiety.  Mni-e  thiv  alone  r<irins  the  pyra- 
mid ;  fnit  thii*  w  undesirable. 

Tlib>  tract  t*  well  marked  out  hv  the  drgoneration  method,  and  thr  dcg«n- 
eralioii  in  it  is  a  deMooding  one,  tlie  trophic  ccnim  of  the  fibres  lieing  cells 
in  iIm-  gray  matter  of  the  cortex.  Removal  of  or  injury  to  the  cortex  of 
Ihe  aholc  motor  ana  gives  rise  to  a  degeneration  along  tho  whole  tract,  and 
reoMval  of  or  iojnrj  lo  part  of  the  area  givei;  riw  to  degeneration  of  some 
of  the  strands.  The  tract  is  also  well  marked  out  br  (he  embryo  logical 
method:  the  lihrett  belonjjing  to  it  aci^uirc  their  medulla  at  times  diSifrent 
from  tboee  of  other  fibres. 

Anltrior  9r  frontal  eortieaL  Fibrea  from  the  gray  matter  of  the  cortei 
in  front  of  the  motor  arvn  also  pass  to  the  intetnal  cajHule,  bnl  occupy  the 
fare-limb  {Viic.  200,  fron).  Thence  they  psK  to  the  crus,  of  which  they 
form  Ihe  ^uall  inner,  mediao  portion  of  the  |>es  (Fig.  192,  /->.).  and  fron 
the  crus  |iato  into  tbe  pons ;  in  transverse  sections  of  the  pons  tbey  are  seen 
as  scattered  bundles  (r'ig.  191,  F.  C.)  to  the  median  tide  of  tl>e  pyramidal 
SbresL  But  here  tlwiy  seem  to  end ;  the  deseneratiou  of  the  tract  is  a  de- 
Mending  one,  lutd  <vuMt  here.  Most  probably  the  fibru>  end  in  tbe  uerve- 
oelk  of  the  gray  malter,  which,  a»  we  nave  wen,  b  abuitdant  io  the  jMMia. 
It  ia  also  }irot)atile  that  tlimugh  these  nervo-cellii  the  libros  of  this  tract  are 
connected  with  lniQ»Ti,-npc  libres  pasrinff  along  the  middle  orebellar  oeduncie 
into  the  cvrebclhim  of  the  opposite  nide;  but  thin  hu.1  nut  lieeii  detinilely 
proved. 

l^dtrior  or  Irmporo-ottipital  nrtital.  Fibrvw  fivm  the  gray  mattw  of 
parts  of  the  cortex  behind  tbe  motor  area  also  converge  to  the  iDtrrnnl  cap- 
sule, forming  the  hinder  end  of  the  hind-limb  behind  the  pyromiital  tract 
rFig.  IWt,  A').  Tbeee  fibres  also  contribute  lo  form  the  crus  ocrchri,  paaiiii 
iolu  Ihe  pes,  of  which  they  occupy  the  outer  lateral  portion  (Fig.  If 


ns 


T1IK    ItRAlS. 


iV.  0.)-     From  the  cms  lliej-  pass  inlo  the  woiib.  where,  like  lh«  llbni 
the  preoedinR  tract,  tlwy  np[)ear  to  end.  and  probably  in  »  Vikn  lowiiil 
ThU  InicI  haa  lievii  <]«fiLTil>ec)  lun  one  of  ofvodin]'  define  rat  inn,  Init  in  all 
probability  like  Ihe  precciliiiti  ia  one  oC  de^t^nAlug  deceDeralion. 

The  nbove  tlirw  tracbi  n(  fibres  may.  therefore,  all  Be  reganl«d  ■•  rtartiiy 
iVom  or  liavin^  tlietr  trophic  reiitres  in  the  <.y>rtical  ifrny  matter  of  the  htm- 
H>here>i,  as  all  helpiux  to  fonn,  6r«t,  tlio  inti-'nial  ca[uule  uid  then  the  |NSif 
the  cniA  cerebri.  Hut  while  the  pyrnmidiil  tract  mnes,  in  part.  In  the  •)<iiiil 
cont,  the  other  two  ocaae  nt  the  jhhih.  and  pmhablr  throuKU  tho  ^ray  niautr 
of  thti  poiin  iiinkc  c<inii(.i.-ti»iin  with  the  cerebellum.  Purtber,  while  tW 
pyraniidul  tnu-t  citming:  from  the  middk'  rt-giun  of  the  cortex  oocii]qeia 
niidille  [Mniltiin  in  the  cap*iilc  and  a  niiddli^  |Hviiti<ifi  ju  tlte  cru»,  the  «ystcB 
from  the  I'ronl  jinrt  of  thf  cnrlcx  uiTiijiir*  a  front  pnnilion  iti  the  capnulc 
and  an  inncT  or  TDcillan  iKwitimi  in  llic  crii#  and  the  sy»ieai  from  (he  Iiia4 
part  if  [he  curlex,  n  hind  pi>»itton  in  the  capsule  ami  an  outer  »r  latml 
jtoiiitian  in  the  crux.  A>  llic  thrt«  syMWDi  paw  from  the  cortex  throuf^  tb» 
caiNfuIr  tu  fonn  the  jh*  of  the  cru»,  their  mrition)>  in  relation  to  ench  olher 
are  nhiiUil  fnun  "oc  plane  inlo  another.  .\»  the  fibre*  "prcad  out  iVom  thr 
pea  through  the  capxulo  to  all  parl4  «f  the  cortex,  or,  put  in  another  way,  u 
they  converge  from  the  corlox  through  the  capmlc  to  the  pv*.  they  form  * 
fan,  the  ciirnna  radiatn.  which  u  not  only  ctirved,  but  the  consUtuvnt  part* 
of  which  cm«  each  other. 

Betides  these  three  systems  nil  paaeing  from  rarimit  rVK)OD«  of  the  mnci 
to  the  crud.  there  is  yet  a  fourth  strand  conlributod  to  t£e  pta  by  tba  Mt^ 
bnl  hcmiiphere,  though  not  stftrting  in  the  corteic.  fnn  thf  nHfhu* 
caudattui  fibres  pas'  down  to  the  cms.  and  take  ud  a  pa«itian  in  tbe  pa 
dorsal  to  the  tracts  just  mentioned,  occupying  a  lana-uiapea  area  imm«diu«lj 
ventral  to  the  auhstantia  uifrra,  and  prolubly  passins  into  the  suhMantu 
nigra  ilaelf.  Tht^w;  uiunut  be  traced  (hrtber  down  tnao  the  poos,  when 
they  ap|ieiir  to  end,  tlmugh  jKWBibly  aome  terminate  higher  up  in  Ihe  mI>- 
stantin  nigra.  Thi.t  traet  hiw  a  (lciu?endinE  de;i:eneratK>n,  and  maybe  re- 
ffantv<l  M  a  tnurt  a:ialu)piu.-<  to  the  front  and  hind  oortical  tracts  though  il 
ntrgiiis  not  in  the  eorlex  but  in  the  Hucleuv  catidattia;  it  is  not,  however, 
a  very  pure  tract,  many  fibre*  of  the  pyraniithtl  tract  pu«anj{  iotu  il  in 
thejK*. 

Tlicae  are  the  main  tracts  of  the  pocUl  nyMcni.  For.  though  tbr  nneUv* 
lentSculaii*  girc«  ofl'  tibrea  tn  the  internal  caprale,  our  kli(>wh'<lge  of  the 
Ibrther  course  of  thew  ■«  at  prcn-nt  imperfect,  and  though  there  wem  lo  W 
lun^tiidinal  Rhrew  connecting  the  biilh,  the  pons,  and  the  [M*  at  Tariou* 
]€«««■.  thcmi  are  not  nunicrous,  and  at  nil  evente  do  not  form  eumtpieuQw 
atnindp. 


I.0MU1TI;DIXA1,  rillltl»  UF  the  TICoHEIITAL  ifT)*TKU, 

$  6M.  0>rlietU  JUrt*.  Although  the  fibres  of  the  pedal  syaleni  form,  a» 
we  have  tven.  tbo  greater  pari  of,  they  do  not  form  the  whole  of,  the  internal 
oapaule.  Fibrce  OOmiOK  from  all  or  nearly  all  [larti-  of  the  eurtex  |Jk'UkI> 
they  help  to  li>nn  the  internal  cajieule.  rlit  nol  go  on  to  form  the  wm,  but 
paw  to  the  optic  thalamus  (Fi):.  1!J4, './.)  and  appear  to  end  iu  inv  gray 
matlcr  of  that  body.  In  Iheir  pai»age  through  the  cap«ule  the  flbrea  of  tbii 
iiAtare  from  the  frontal  and  jiarietal  n^ons  of  the  ci^rtcx.  ncciipy  the  extremr 
front  end  of  the  front  limb  m  front  of  the  frontal  straml  of  the  tibrcs  of  tlie 
of  the  pedal  syuem  (Fig.  VJ'J,  Tb.).  The  fibre*  from  Ihe  on'ipiUil  aiid  tern- 
-nral  rc);innit — tho*e  fiirin  the  oodpital  nigbuu  being  the  moat  iiiiRM-rou*. 
'-lUecil  being  vwy  cwupkuouc — occupy  the  extreme  hiixl  end  of  the 
t 


LON'OITCDIltAI.   riBRKS   OP    Tilth    TBOME.VTAL   SYBTGH.      719 


hfod-limb  of  the  capsule.  Kebind  the  teroporoHicGipttal  division  of  the  pedal 
■mem  (f'*iK.  \iH>,  Op}-  ^-iuc^,  as  uc  shall  lee,  w«  have  reaiton  to  aaeodau 
the  (x.-eiDiial  region  of  the  oonex  uiih  vitiioo.  thv  fibrv*  ihuii  nidititiag  to  for 
from)  tne  thabiroui  through  tho  exlri-tne  btiKl-liinti  of  tti<-  ('ii|^<i>ulc  Irom  (or 
to)  the  occipital  MiMex  hnve  Wen  fiilleil  ihi-  u/ilir  railoition. 

All  the  aoovi'  traci.i  of  librr*.  Uioujfh  joininji;  tlii;  llialnniun  aii<l  not  potting 
on  to  the  f)M,  (nkv  purt  in  ihu  forinaiiou  uf  liit!  internal  ai|Mul«t.  Btit  ■  con- 
•idenble  mimberur  rihrc*  I'dmiufj;  from  Ihr  ti-inporo-occipital  rveiiui  nod 
etpecially  (rum  the  letniionU  region  iiiiw  to  tbr  thaUinn*  without  joining  the 
capMile:  thejr  ban  rentnil  to  kikI  U-hind  tlio  pm  m  thii  pluugCN  tnto  the 
hembphere  tii  Wcoine  llic  cni«uli.',  urid  s<>  r«icli  th>.-  thiilikniii)>. 

We  tniiy  Iwrw  p-rhapii  liivcrgc  for  a  monH'tit  to  point  out  the  contnut 
betwreii  the  optic  thnUuiiiv  and  the  corpus  strialum,  or  at  lcn»t  the  oucleua 
caudniiuL  Thi>  fonncr  don  not  contrioule  lo  the  pedal  tyxtcm,  lh«  latter 
nupplic*  a  marked  contribution,  The  former  receives  Ubres  from  alt  purta  of 
the  cortex  :  there  are  no  luch  special  oontributions  frotn  the  cortex  to  the 
latter.  .\nd  lhi«  differenoe  accords  with  the  experitrncc  that  when  partit  of 
the  cortex  are  removed,  or  are  eongenitalty  absent,  no  defeneration  or  want 
of  developntenl  is  ohserred  in  the  corpus  striatum,  while  degeneration  or 
want  of  development  is  obwired  in  the  optic  thalamus  as  well  as  in  parts  of 
ihr  pedal  and  le^'mental  syatCBW.  llenoe,  while  we  may  regard  the  opiic 
thalaiiiu*  as  nn  intrrnieiliale  mass  of  Riay  matter  receiTing  tibres  fn>ra  the 
cortex,  and  cnuneeling  the  cortex  with  lower  pans  of  the  tegmental  region, 
tbtf  corpus  strialom,  Appears  mthcr  to  be  analogouH  to  the  cortex  itself,  (o 
be  a  special  modilicatioR  of  the  cortex,  sending  fibres  down  into  the  pedal 
l^Vtcn,  but  itself  receiiing  no  special  tract*  of  Rbrcs  from  the  cortex.  Indeed 
wcmay  probably  regard  the  corpus  atriaiuiu  as  tlw  oldem  part  of  the  super- 
ficial i;ray  matter  of  tbe  heiuiiipliere,  the  more  onlinary  cortex  being  a  lattr 
develupuem. 

Tbe  tef;mentum  pniper,  lying  vcutivl  to  the  hind  end  of.  and  behind  the 
thalamu«.  in  which  reui"'!,  a>  we  bare  sct^n.  the  conspicumis  rcil  nucleus  is 
•iluated,  t*  thus,  by  riuinon  of  its  connection  with  the  ihalamuH,  indirectly 
connected  with  the  cortex.  But  Ixvidcs  this,  it  has  direct  connection*  of  It* 
own  with  the  cortex.  Some  of  th«  fibres  of  the  optic  radiation,  as  well  a« 
fibm  from  Uw  temporal  and  occipital  regions  described  above  u  sweeping 
round  the  baae  of  the  iiitenml  cansuh-,  are  saiil  to  pass  not  to  the  thalainiis, 
bvt  lo  the  tt^mcntuni.  Other  fibres  fmm  the  frontal  and  parietal  rt^ioaw 
liavfiting  the  lenticular  nucleus  in  ihe  sheets  of  while  matter  tnlittiDg  tlM 
Bod*lM  into  parts  ar«  also  said  to  reneh  tlie  legmeotuni  either  by  piercing 
thiwigh  or  byswaepjng  round  the  interual  capenle.  On  tlieir  path  iltcM 
fibres  are,  according  xa  sonw  obMrverv,  joined  by  fibres  coming  from  the  Icn- 
lictdsr  niteletis  ilself,  and  possibly  firou  the  caudate  nucleus,  wbtcfa  fibres,  on 
the  Tiew  that  these  nuclei  arc  modified  ooriex,  may  also  be  ooosiderHl  a» 
conical.  Thus  the  fore-part  of  tbe  (egmenlal  resion  is  brought  into  ample 
connection  with  tl>e  cerebral  hcmiipheri-  partlv  bv  libnr*  joining  llie  thala- 
mus, partly  by  libres  |m»ing  directly  to  tin-  tt-giuentum  pniiwr. 

Tbe  mode  of  degeneration  of  tbeee  cortimi  hbnv  of  the  tcgraeiilal  system 
is  at  present  a  matter  of  ditjiute.  Nor  i>  the  general  oatiin'  (if  tlie  tibrvs 
concluKivety  detenuinetl,  though  it  in  eem-nlly  Mip[K<s"d  that  tltey  cany 
impulMd  from  the  thalamus  and  parts  oTthe  ICEmentum  to  the  cortex. 

I  63S.  I»  the  tegmentum  from  tbe  subtlinlmic  region  to  the  bulb  the 
reticular  furmatiuit  u>,  as  we  have  scrn,  more  or  less  abundant ;  this,  and  the 
occurron'r  of  variouB  bundloi  of  fibre*,  gives  the  region  great  complexity ; 
and  «e  must  confine  ourselves  here  lo  touching  on  one  or  two  important 
looglludinsl  Mrand*  nhich  iravcm  it- 


11k  tufterior  peduHcit  af  tlu  eerebeUma  in  on«  of  the  mosl  impoflant  ofl 
llieae.  TkU  mi  each  ude  nf  n  bundle  nf  fibres  which,  Mkinc  origia  chiefly 
from  the  gray  muli^r  »r  i\\r  iiucli'ii*  dviiiutii*,  und  the  tnuiUer  noigbliorinit 
ci>lleciii>n  of  ft'iiT  >nalU-r,  liiil  iilii»  in  lutrl  Trom  th«  tuperficiKl  zr%j  nuOcr, 
leuveo  (be  ccrubulluin  in  fruot  of,  itnJ  l«  iho  niudian  side  of  tae  rotifortii 
IhiiIv  hdiI  ]<«i!M(v  forwnnl  lawurd  the  ciirjxirii  (jitudriffemiita  to  converge  vith 
ii.->  telliiw.  At  RrM  ih«  two  pmluncle*  am  viipcrficiB)  Kiid  doraal  in  pontioa 
(Figa.  189.  liiO,  .S'.  f.)  iind  the  spnco  bclwocn  lh«m  i*  bridged  over  by  tbt 
vnlve  of  VteiiSA'n*  (Fig.  li"),  Vln);  but,  still  conv«rgiog,  thej  mmu  tiak 
vwiirally  Ih-im^jUIi  the  ["wtwnur  corporn  qundrigrniinitaiid  at  I  be  level  of  the 
juticli'xi  Ix-rwix-n  the  itnterior  itiid  pintt^rior  corpora  ijuiulrigvimoii  meet  t»l 
dccu»iai«  vcntml  lu  thtiee  bodies  iii  the  VL-nlrnl  region  of  tbu  t«gnieiiluai  (Fi^ 
li^I,  iS.  P.).  Beyond  the  decueaation  (hey  arc  coDtiiiued  forwanl  in  the  tcf;- 
nitntiun  ventral  to  ihe  an(erior  corpora  qiiadrigeminn  u*  (vo  straurla,  oik 
on  vaeh  side,  which  appear  to  end  in  (he  red  nncloi. 

In  ihU  nny  ihe  peaunclea  connect  tert&in  parta  of  the  cntv  ina(X«r  of  lb* 
n<r«bcllnni  with  the  tegmental  region,  and  more  particularly  with  the  nd 
inicleiu,  and  thus  indirectly  with  the  simctures  with  which  that  region  u 
itMilf  connected. 

ThetiiUt.  This,  at  ve  have  iiecu  (J,  GIZ),  takea  origiii  in  the  bulb,  b  tbf 
intcr-olivary  layer  bulweeo  the  inferior  olivw,  frum  fibres  which  arc  derived 
thivugb  the  nupra- pyramidal  or  nejuury  decuieatton  iVoni  the  Knu-ile  ud 
cuncate  nuclei.  Fnmi  thin  origin  it  patwa  forward  on  each  udt  iw  a  Hal 
band  into  the  lejfmiMitnl  region  of  thr  pon*,  receiving  scceflBtODs  from  tlw 
superior  olive  and  ')thcr  collecticin.i  of  grav  matter,  and  dividing  them  into 
two  straiidn.  the  mtflian  (FigH.  1!)0,  191.  Fin)  and  latorat  (Figs.  l!tl>.  191.  fl 
and  Fig.  Ififi,  HF)  filial.  Tlif  lunral  itiviKinn  end*  i>artly  in  the  gray 
matter  of  (he  posterior  corpus  f|Uadrigotninuni.  and  partly  in  the  while 
muter  nndi^rlying  (Fig,  11';!.  itm)  the  luitcrior  corpus  <|uailrigi.<minum ;  the 
median  division  puseing  further  forward  appears  partly  to  eiid  in  tlie  gny 
matter  of  the  anterior  corpus  ()uadrigeniiuiim,  but  [lartly  to  be  condnnca  on 
lo  the  subthaluDiic  region  of  the  tegiueiitutu  ventral  tn  the  tbalamiM. 
to  the  tholaiuui,  and  so  to  the  cortex- 

Tke  toiufitudinrU  pontunor  bui>dlt4.  In  a  transverse  wction  ihmagh ' 
funvpart  of  the  pona  at  the  level  of  the  posterior  corpora  quadrigi-reinnl 
rather  conspicuiua  bundle  of  longitudinal  Gbree  (lulled  the  loiigitndini 
poaterior  bundle)  in  hkh  <in  each  aide,  cut  transvereely,  in  the  dorsal  n-gifl 
of  the  tegnientum  junt  ventral  to  (he  nucleus  of  the  fourth  nerve  I  Fig..  \'J\  ' 
Traced  backward  fmm  (he  Hijiii'duct  l>encatli  the  fourth  ventricle,  it  bcconi 
len  eanapicuouii  (Fig.  19U,  I)  though  niaintuiuing  ii^  position  dorwl  to  ibt 
reticular  furmalion.and  at  llic  hind  end  of  the  hulb  up  pen  re  to  be  a  continn- 
ation  fomard  of  thnl•l.^  libnv,  "ground  fibnw,"  tif  (he  anterior  column  of  tbt 
cord  which  probably  f^rve  n»  HuccnMive  thurt  luUKitudinal  coraniiamna 
between  the  si^aieats  of  the  cord.  \^'hilc  the  vomewhat  aualogoue  lillei  runs 
ventral  to  the  reticular  formation,  this  |KP«t«rior  longitudinal  buudle  ruoa 
alway:>  donwl  to  llitit  ctriictuiv.  It  may  be  traced  fomunl  as  far  as  tbe 
nudeui  of  the  lliird  tiervc,  as  is  seen  in  traniveiac  aectloiu  lyiug  immediately 
ventral  to  that  group  of  cclU  i  Fig.  192./).  but  it»  further  counet-tious  f>rwanl 
have  not  as  yet  been  determined.  It  is  relatively  more  pniuiueui  in  the 
\nytfr  than  in  the  higher  animals,  and  its  fibre*  acquire  their  roealulla  rela- 
tively early.  It  is  supftoeed  to  be  connected  with  the  nuclei  of  the  nerves 
t^reniing  tlw  niusolce  of  the  eye,  and  so  lo  be  eoncenied  in  the  marements 
\m  that  organ. 

TrttrUfrnm  thf  ixtrpon  <iHailri^mu\a.    From  eoch  corpus  ((uadragcminu 
tliere  puMw  obli<piel}-  forward  and  downward  on  each  aide  a  band  of  filir 


TBANSTKBSK  OR   SO-CALLKU  COHMlSSlBAb   FIBBBS.     781 

ineded  wilh  tbe  Ktar  matter  af  lli«  coq>ua  oaA  kwtua  ta  iu  hrafhitm. 

«  anterior  bracfaium  (Vig.  I'J'J,  7Ai),  as  *re  shall  t>e«  in  iltaliug  witli  Ihv 
^»tic  uerve.  joins  ilie  latcnil  ii<r|iii!S  geniculaium  aiid  )ivI|ih  t<>  I'oriu  itie  nptio 
tract,  Irtit  »boi«orit£i^let'|'er  Iviiif;  libree  proceed  lo  ibe  octipitat  oirlpx  tltnu- 
ing  part  of  ili«  tibr<-!i  nhich  *»  liuve  (§  (>34)  described  a*  riiiHiiiji  from  the 
ooci[Htal  cnrtex  to  uml  jwHt  ibe  thalaniUH.  The  tMHlerior  brui-liiuiu  pBnac* 
ta  tue  Rwdiau  cvr^ma  ({i-tiiculttliim  ;  biivinjr  receiTed  tibri-n  tVotn  nud  nromblv 

E'vrn  fibnt*  ujitotbat  l>i>dv.ii  ia  i-nuiiuuM  onto  the  li-i;iiiciiiiiiii,iiiid  accord- 
g  to  tome  ■iithnm  through  the  legm^nlum  by  th«  bind  part  uf  tbi^  bind- 
linb  of  ilw  iiiienml  cii|wulv  t»  iho  (fnipHrnl  n^nn  i>l'  ih<>  cortex,  mingiint; 
tn  hs  couiM  Willi  libroi  rrom  ibe  thalamus. 


TIUXSVEIISR  OR  MOCAU.KD  (t>MMt880RAL  ftBIIDf. 

S  636.  Tbe  two  chief  mrmn  nr«  thow  on  the  oni:  hand  bolongiDg  to  U»e 
cerebrum,  and  those  on  (be  other  htind  bclongiDK  !'■  the  cercbrtltim. 

/n  the  ftTthrum  thi>  mott  imposing  mius  of  irumverw  tihr«s  from  the  a»T>iu 
taOottim.  Starting  fram  the  cortex  in  Dearly  all  parts  of  ibe  hemispbere. 
ibo  Rbrefl  convert  loirard  the  thick  body  of  the  corpu!  callosum  placed  in 
the  middle  line,  aud  llicnce  diverge  to  nearly  all  parts  of  tbe  cortex  of  tite 
haniipbem  on  the  oilier  side,  interlacing  in  tbeir  course  with  the  cortical 
tbrea  of  the  pedal  aud  le^iiienlal  systems.  It  is  Buppowd  that  by  lueaOB 
of  theae  fibrea.  each  part  of  ibc  curies  of  one  hemiepliere  w  brought  into 
'i>n  with  the  curreeitondin^  part  of  the  other  bemisphere. 
s  thcae  callcael  nbrea  trom  ooe  lieiiiixpherc  to  another,  the  vbite 
)er  of  each  bemispliere  contains  fibres  cbIImI  "  asttiiciaiion  Rbrea,"  {Mannj^ 
fh>Di  one  cnnvoluiion  lo  aootlier  of  the  same  heTiiis|>here. 

The  iinnll  antrrinr  tvhil<  mmtniMuiy  though  it  in  placed  in  the  front  i«Tt 
of  the  ihinl  ventricle  (Pig.  198,  A )  and,  in  jxirt  of  it«  counc,  lies  along  the 
ibalaiDiiB  I  Fig.  ll>'>,  (])if  i»  really  a  coinniiwiirc  of  particulnr  parl«  of  the 
cerebral  hrniiFpbt're*.  .\  [rurtion,  very  Hoall  in  man,  boEongn  li>  the  olfac- 
tory tract :  the  reat  takes  origin  on  each  side  in  a  limited  jxirtion  of  the 
cortex  (Fig.  194.  Cc).  which  we  shall  Inter  on  speak  of  as  the  tempom- 
vpbetXHdal  convoliitioa  and  in  which  calto<«l  tibm  are  deficient,  whence  it 
arobee  forward  throng  tbe  globus  pal lidns.  past  the  thalamus  (Fig*.  201.  ra, 
1&&,  (bl  to  the  front  nan  of  the  third  ventricle.  It  may  be  remarked  that 
ibit  ootnmifisure  is  still  tbnnd  in  those  lower  animal!:  which  do  not  poeaoro  an 
obvious  corpus  callosum. 

The  ainall  poeterior  commiMure  niay  be  regarded  ns  mainly  a  commiNRire 
between  the  two  tliolami,  but  It  alto  belp*  to  unite  the  tegmentum  of  the  two 
aidea  and  some  fibres  are  Bai4l  to  paas  on  each  nde  inM  the  hemisphere.  The 
middle  or  soft  commissure  of  the  third  ventricle  ( Fig.  193.  c).  thuugh  it  con- 
luiiu  IraDiTerse  flbres,  ia  in  the  main  a  collection  of  gray  matter,  indeeil.  a 
part  of  the  central  gray  matter. 

Tlw/orMLT,  to^ber  n  tth.  al  all  events,  part  of  tbe  septum  lucidum  which 
join*  it  wilh  the  corpus  cullosuiu,  must  also  be  regarded  sa  a  comminwral 
structure.  But  its  relations  are  peeulinr;  for  while,  l>ebind,  tbe  direrxing 
poatsrior  pillars  begin  in  tlie  cerebral  liemttpberes,  uamelr.  >n  the  «alu  of 
tba  dtacendiiig  Ikoni  uf  the  lateral  ventricle  on  each  tide,  in  /Vont  the  anterior 
pniail  or  eolumn*.  Icnviug  the  cerebral  hemispheres,  pus  nloug  the  lateral 
walls  of  the  thir«l  ventricli.*  (Fig.  19M, / ),  and  apparenttr  eml  in  the  gray 
matter  of  the  corpora  ulhii-antia.  WhetlKr  tbe  band  of  fibn*.  known  as 
Vic<id'Asyr'8  bundle  (Fig.  UU.  I'fr),  whieb  running  in  the  lalcral  wall  of 
the  tnird  ventricle  leads  dorsully  from  lach  corpnii  alliiciuu  up  to  tbe  anterior 


TBI   BB&IX. 

nuclMUof  the  llixUiuu*.  li  reatir  lu  t>«  ronxiilfrtMl  lu  a  ounliiiunli'in  af  iki 
fornix  it  dbptitorl ;  it  mar  more  prolmbly  bi;  ivgartlc^  w  n  pari  uf  tlie  tjtum 
spoken  of  itnnvc  a*  oiinecting  tnv  vurtcx  ifilh  tliv  (hnliimas. 

h  tlte  eercbrllam  true  onimisaiiral  61>re«,  «rv  supplied  hj  the  auiUlr 
jwJuhoIm ;  but  by  nv  menne  itll  lh<:  (ibrea  uf  thcev  p«duDcl«  w  of  Hm 
nature.  The  Hbrat  of  the  tnidillv  poduncle,  in  oootrnci  to  those  iirtbi  up»- 
rior  peduncio  which  Klnrt  cbieflv  from  the  nucleus  dentatui,  or  other  iotcral 
jtntv  iDRttor,  nnd  U>  th<i«e  of  tite  inferior  peduncle  which  start  chicDr  fraa 
the  superficial  gray  mnlter  of  the  vermis,  appctir  to  start  from  tho  HiperfieU 
gny  niatt«r  of  the  wrliote  anrfnoe.  from  that  of  the  median  rermts  at  well  u 
fnim  thai  of  the  lateral  hemispheres;  ihej  lhu»  form  the  greater  part  oflltt 
ceDtral  while  matter.  Sweeping  down  into  the  pong,  they  form  the  trau- 
verae  fibmi  of  that  body,  interlaeiiig  with  the  longitiidioal  libres  of  the  crural 
^ytiem  and  iotecniDgliDK  with  the  abundant  gray  matter. 

Of  theae  tnuisvene  fibio  ot'  the  pom,  a  ctrtaio  number  are  trulr  ocmiiw- 
fural :  they  mako  no  coDiieelions  with  eells  in  the  poiu.  but  coutitine  tluir 
way  uiibrohen  across  it ;  they  »larl  in  die  superficial  gray  mutter  of  uoe  ndf 
of  till-  c-efebelluiu  and  end  in  the  superficial  )cruv  raatlvr  ai  the  other  lida. 
tho  parts  or  the  gray  matter  thus  united  being  probably  Liirrtupondiug  put*. 
The  niDBt  vetiLrally  place<l  trannvente  Obrca  of  the  potu  which  form  a  Mpcr> 
ficial  layer  of  white  matter,  free  from  gray  matter  {Fig.  189,  tr.  P,)  an 
i>robably  of  this  nature,  as  arc  alao  the  tninsrerac  fibres  plued  mou  dorialty, 
just  veutral  to  the  tegmeutal  rcfpon. 

A  lar^  number  of  the  traii:>vcr»e  fibres  arc  not  of  tbb  uaturo.  'They 
orow  from  one  aide  »f  the  ocrcbullum  to  the  onpoeita  ndt  of  tba  pooi.  b«'t 
end  in  tbc  ponM  apiAreiitly  iu  the  ner^'o-celU  of  the  grajr  mattar ;  and  tl  b 
soppowl,  that  by  thcM  nDrv«-e»il»  iboy  arc  briHigbt  int*)  counoctinn  with  th« 
longitudinal  fihrm  of  tbo  pedal  syflem  and  thus  with  tlw  oerv^rum.  They 
are  Iransveree  a|ipcndag<>*  of  the  [ledal  system,  not  true  commtaMiral  fibns 
though  thev  do  eroe*  the  median  line. 

It  N  further  supposed  tlial  other  tibr«  of  the  middle  peduncle  reaahiag 
the  pons  do  not  croffi  the  median  line,  but  k«ei>iug  tu  the  same  aide  and 
chaapng  their  direction,  tnke  a  loni^itudinal  upward  course  either  wUh  or 
wlthocit  the  iaierveniion  of  nerve-cells,  and  so  make  their  wajr  to  the  leg* 
awntuui.     llul  this  is  not  certain. 

We  mual  ubu  consider  as  oommissaral  stnictnrea  the  numerous  ftbres 
crowMug,  or  serving  to  fonu  the  raediaa  ra|kl>e  in  the  bulb.  Thin  raphe:,  with 
similar  commissural  fibres,  is  present  in  the  tegmental  portion  of  llic  puu, 
and,  indeed,  in  the  tcgmenttiui  itself. 

Fibres  also  oross  from  one  Aide  to  the  other  in  coDDOction  with  the  cranial 
nervnt,  but  theae  •»  well  at  all  the  ti^acta  specially  ooonected  with  the  cranial 
nerves,  ineluding  tlte  ul&otory  and  optic  uervet,  had  better  b«  cooBidered 
bv  ihcmselvvt. 


SirUMARY. 

^  837.  It  muv  perhaps  apficar  from  the  foregoing  that  the  brain  coansts 
of  a  number  of  isolated  maasos  of  gray  matter,  and  some  large,  some  small, 
OOQDected  tccethor  by  a  multitude  of  ties  of  white  matter  arranged  in  per- 
plflXlDg  iotncacy  ;  aixl  the  nd'Iition  of  numerous  ooUectiuns  of  gray  matter 
aod  strands  of  white  matter  of  whirh  we  have  made  no  mentioa  would  »iill 
Airtber  iorrrasi-  the  perplexity.  Nevertheless,  a  systematic  arrangenent 
mav  be  rec<3gni]:e<l,  at  least  to  a  certain  extent. 

The  least  conspicuous,  but  perhaps  iu  point  of  origiu  the  oMnt  part  of  the 
brain,  teems  to  he  what  we  have  called  the  central  gray  matter.    Thia  soems 


SL'UltAUY. 


783 


iy  t»  m  bci]  fur  the  development  of  tin  nuclei  of  tli«  cnuid 

I  Ui«  oTJitrnl  gnif  ranttor  wul  more  or  leu  a«odi»tmI  wiLh  it  ramea 
irtiAl  we  liuve  called  the  togmuitiil  region,  of  which  tbe  micular  tunnatjon, 
eomiog  into  prominence  in  iht  bulti  end  continued  oo  to  the  »ubtbalamic 
nigiaii,  Ibno*  oe  it  were  the  core.  Belonging  to  the  l«Kmeatnl  Bfsleui  are 
nniDdnias  mMtee  of  gray  natter  from  the  conitpicuipiis  optic  ihnluiuui  and 
th«  red  nndetti  in  front  to  the  MVcral  nuclei  of  the  bulb  buhiud.  Tbia  com- 
plex tvgnientnl  ay»tem,  which  may  perha|M  be  regnrdvii  tu  a  more  or  leu 
eontiniioiis  column  of  K^ay  iimlter,  comparable  to  the  gray  niatler  of  the 
B(Hiial  cord,  serves  nit  a  sort  of  bnek  booe  to  ibe  re«t  of  the  central  iiervoua 
■ntetn.  With  tlie  s[hiui1  oord  it  ia  connected  by  various  liai,  lieiii<leit  being 
aa  it  vere  a  cootinuatiou  of  ihe  spiDal  grey  nutter,  and  around  it  are  built 
H|>  tbe  Kr«at  mius  of  the  cerebrum,  and  the  Hmaller  but  still  larj^cr  maM  uf 
ihe  oeivbellum:  the  leas  important  corpora  (|uadri)[einina  we  may  for  sim- 
plicity's Mtlte  neglect. 

At  the  tiiud  ejid  we  find  varioua  jmrta  of  tbe  iipinal  con!  becoming  coti- 
uected  with  ibijt  tegmental  system,  either  panio);  into  it  and  becoming,  a*  far 
as  our  preoent  knowledge  goett,  luet  in  it,  or  iu^iplyingntrundsurtlbna  which 
paiiing  into  it  Income  through  it  connected  with  other  |mrU.  Thai  the  au- 
lerior  column  of  the  oord  exoluslre  of  the  direct  pyramidal  tract,  the  Utcml 
ctilumu  exdutive  of  (he  criMwd  pyramid:!]  nnd  (xirvbHllur  trtuttd  (aiidpiiMibly 
the  an lero- lateral  avcciiding  truci),  tu;;i^iher  with  jiarl  >if  thi-  jiiwtrriiir  column 

rsar  to  join  the  teemeiilal  NynlL-m,  while  piirt  of  the  jwist^rior  cnliimii,  after 
rday  uf  the  grncile  umi  curi<-alu  nuclei,  |ubu«>  through  tht-  nyntcm  lu  tlit- 
fillet  dnrtiiKil  for  various  ittriii;tiires. 

At  tin-  front  end  we  lind  iill  parln  of  the  c«rchral  corlvs  (,thvugh  some 
ngiooa.  namely,  the  rnnipDrD-nocipiliil,  lo  it  gr>.iit<ir  extent  than  othemi,  con- 
nvCied  with  tbe  thalamus  aud  other  |Mirl»  ol  the  tegmental  ayslem  ;  and.  at 
a*  ire  have  seen,  tbe  corpus  etriatum  rany  postibly  pooseta  like  connectiotu. 

The  relaliona  of  the  cerebellum  to  tlit»  spritem  are  notable.  On  the  one 
hand  the  cerebellum  ia  directly  connected  with  the  system,  partly  by  fibrce 
which  paas  from  the  bulb  to  jwn  the  reatiforra  body  or  inferior  peduncle, 
partly  oy  the  superior  peduncles  which,  as  we  have  seen,  are  in  n  measure 
lust  iu  the  tegmentum,  and  partly  probably  by  fibres  of  the  middle  peduncles 
also  making  connections  with  the  tegmentum.  On  the  other  baud  tbe  cere- 
bellum form*  around  the  te);mcutal  ityslem  a  great  junction  between  the 
H|iinal  curd  and  tht-  cerebrum.  Ti>  the  Hpiual  cxtrd  it  ii  joined  in  a  direct 
manner  by  iliv  oerehr^lbir  tract  and  |>oa>ibly  by  ibe  a ntero- lateral  asoendiog 
tract,  and  in  an  indirect  manner  by  the  reluy  of  the  gnieile  and  cunnte 
nuclei.  To  all  partn  of  the  cerebral  cortex,  it  up|i«ani  to  be  joined  by  tboae 
ooMpicuoua  Mtraud*  of  tbe  [ledal  nytitem,  which.  a.i  ire  have  seen,  end  in  Ihe 
pooa.  and  tlicre  miikii  ii>nuectiuiii<  with  the  fibroi  of  llw  middle  jiedunijc. 
And  we  may  iK'n;  jN.-rha|ici  tviuark  that  while  tliu  connection  bclw(.'en  the 
etnbrum  and  oereWlam  in  whidly  a  erUMetl  one,  each  cerebral  heininjihere 
being  jojned  with  thvoppiMlu  half  of  the  cL-rel>ellum,  tbe  conuL-ctioiu  between 
tbe  kpinal  coni  and  the  o<Te)>elIum  are  hirxelv  uncnewl  one*,  that  by  tbe 
ocrvbeltar  tract  being  nholly  uncronooil,  and  that  with  tlic  jioatcrior  column 
by  the  relay  of  the  gracilc  itud  i-oDi»tv  nuclei  l>cing  in  [<«rt  uncroaied. 

Thus  the  cerebral  oorlcx  Ium  a  double  hottt,  so  to  s|>vak,  on  the  real  of  iha 
cmtnl  nervous  «}-«t«m,  fir*l  through  the  the  Kwmautal  systom,  and  soeoudly 
through  the  oerebcllar  junction.  But  in  addition  to  this  there  is  another  tie 
betweeti  the  cerebral  cortcs  and  the  wliolw  length  of  tbe  oersbro-epinal  nsia, 
or  at  leut  between  it  and  tin-  whole  scries  of  motor  mechanisms  in  sueoosston 
from  the  nucleus  of  the  third  ner\-e  to  the  nucleus,  if  we  may  so  call  it,  oi' 


7M 


THE  8RAi:r. 


the  nbierior  rixji  of  the  coccmwl  n«r%-e,  iiura«ly,  ihc  fcrt»t  |iyntmUUI  Inn, 
which  thiiM  upiwura  m  a  miuMiiEd};  *iipera<iil«d  lo  all  tba  rat  uf  lb«  «enuid 
iKrvoiis  8}'8tem. 

Wh«n  the  cen'.bral  hemuphrres  tire  reraorecl  thit  prntmidal  trart  &Bi 
airny  aa  ilrN»  nlsii  the  peilnl  syslein  Iciuling  rn>in  ihc  ccrchrum  tu  lht>  [uru, 
but  there  rtill  remninfi  ihr  legiui-jital  :>_r»lcm  with  \t*  ifrcbellar  and  otbff 
iidjuncls  iind  this,  n^  we  shnll  see,  eoni'tiiiiU'a  n  nervoiiK  lunchioor;,  capaMt 
of  ciirryitig  luit  excealinglr  compHcntcd  acts. 


Ok  the  Phknomisa  RxiiiiiiTKu  UY  AN  AxiUAL  DKritivKd  or  na 
Cbrkbral  Uemhpiieres. 

{ 038.  The  cerebral  heniiHpheree,  as  we  bare  more  than  once  iiisistciL 
•eetD  lu  Btnuii  apart  t'nini  the  reel  uf  tlie  brain.  Id  the  ciue  of  aomv  antnuib 
it  is  pnwible  lu  remove  the  eerebral  bemiapherea  and  to  ke«p  the  aiiinuJ  doI 
ooly  alive,  but  io  good  health  liir  ii  loii(c  t»ii« — days,  weelcH,  or  eveu  nicalh« 
all«r  the  operation.  In  xui'li  raae  we  are  able  to  Mudy  the  Itehavior  of  u 
anininl  posM«iiinK  no  uerebrat  be  in  sphere*,  and  M>  iiimpnre  it  with  thai  of 
an  intact  animal.  Sueh  un  cx|H^rimetil  is  best  i-arned  nut  on  a  frog.  In 
this  niiinitti  it  is  i^ompiinilivelr  vn»y  t*>  reoMVO  ibc  cftrcbral  beinbphmK 
irichiding  the  pnrls  ciirn^p'iiiiliTig  In  thf  rorpora  striata,  leaviog  bchinil 
intact  itnd  uninjured  the  ojiiir  thntnnii  with  thtr  opiii'  nt'rvcs.  th«  oniic  lohf* 
(or  repre»<^ni«tivi-s  of  tlic  ooqicrn  iiuiidneeiiiiiin),  the  small  eerrUiflura,  aiid 
the  bulb.  If  the  animal  Ik-  cnrrfnlly  ft-d  and  attended  to,  it  may  be  tw|it 
alive  for  a  very  hing  time — for  nu^re  than  n  year,  for  invlanM'. 

The  ealicnl  foot  nboiK  a  fm^  Inciting  the  eenibral  liemisphercs  is  that.  ■* 
iu  the  case  of  a  frojj  deprived  of  il«  whole  brain,  the  siftns  of  the  workinirur 
an  inl«lli(cent  voliiion  are  either  wholly  absent  or  extremely  rare.  The 
presence  of  the  bulb  and  the  middle  parts  of  the  brain  (for  «o  we  may  toe- 
venieutJy  call  the  cerebral  stnictuive  'ying  between  tl>e  verebral  benmpher» 
and  the  bulb]  insures  the  healthy  action  of  the  rascubir,  retpimtory,  ais) 
otli«r  iiurritive  systems;  food  placed  in  the  mouth  is  rMdilyanil  easily  swsl- 
lowed;  the  auimni  when  stimulated  executes  vnrinus  movements:  but  if  It 
Im  )eA  entirely  to  itavlf,  auil  care  Iw  taken  to  shield  it  from  advenritiuv 
stimuli,  either  it  reinainN  |>crf<'ctl^-  imd  pennaDciitly  ljuieacent,  or  thr  appar- 
ently spouluneous  nMvom(!nt:>  which  It  carries  out  an  so  fijw  aotl  ■<(  Hmitel 
as  to  make  it  very  doubtful  whether  they  ran  fnirty  )w  called  vuIitiunaJ. 
Such  a  IVtig,  for  inxtjincv,  nfl«r  heing  kept  alive  for  some  time  and  made  lo 
exhibit  the  phenomena  of  whicli  we  an-  aliout  Ui  s[M«k,  has  been  placed  on  a 
table  with  a  line  drawn  in  clinik  aroiiti<l  the  urua  covered  bv  iU  body,  and 
lef^  to  ittclf.  has  KnW']iH'Dtly  been  found  dead  without  havTng  stirrM  oul- 
sidc  the  chnlkitl  circles 

Wc  must  here,  howrvcr,  rejicttl  Iho  caution  laid  down  in  §  S83.  as  lo  the 
ultimate  eflects  of  an  upcnition  on  the  <^vnlral  nervouH  syvtem.  The  longer 
the  frog  is  kept  alive  and  in  gotx)  health  afler  the  removal  of  the  cerebral 
beiDtSpnera,  the  greater  is  the  tendency  for  np{mrently  spontane^Mis  more- 
meots  to  show  themselves.  For  days,  or  even  weeks!  auer  the  operation 
there  may  be  do  agon  whatever  of  the  working  of  any  volition ;  but  after 
ibe  lapse  of  months,  movements,  previouely  absent,  of  such  a  cbaraeter  as  to 
auggat  that  tbey  ought  to  be  called  voluntary,  may  moke  their  ap|>eanuK«. 
To  this  point  we  shall  return,  but  may,  in  the  meanwhile,  slate  that  eveu  in 
their  most  complete  ilevelopment  such  movomenU  do  not  negslire  the  view 
that  Ihe  troz  in  the  alMence  of  ihe  cerebral  livnii^pbcres  b  wanting  tu  (rhat 
,  we  onlinari^  call  a  "'  will." 


WITIIOCT   CEREBRAL    HEMISPHERES. 


786 


I 


Wr  have  t*xa  (httt  a  froji  from  wliiuh  ibp  nhotc  brnin  lin»  t>«;n 
Bvdi.  KiMi  ihp  spirul  cor<i  only  kfi,  npponn  ^iniilnrlr  'tcvoiti  "f  »  "  will ;" 
^tlt  iht?  I'hcnompnii  pmraUii  by  n  frog  iiQwcwin^'  Uic  mi<J<)lv  |>ortioni)  of  the 
bmin  fliiliT  wii]ely  Irum  th-.««  iirvfciiieti  br  n  fm^  yn^nt.Mig  n  tpinml  cord 
oaiy.  We  m«y,  pcrhnp*.  Iirondiv  ilowribc  tlic  bclmviorof  n  iVog  from  which 
ibe  cerebral  hcinW|>ht>iTfl  oiity  hiivc  been  remorcd,  bj*  Miviac  ihnt  such  an 
aDinial,  tbuugli  exhibit  in)*  no  epoiitaneoiis  movements,  cao  by  the  ttpp  lien  t  ion 
of  appr»|jriate  slimuti  be  iiiduceil  to  perform  all,  or  nearly  all,  toe  luove- 
meats  which  an  eu(ir«  fmt;  is  capable  of  ex«ciititi);.  It  <.-aD  b«  inad«  toawim, 
la  leap,  awl  to  crawl.  IJetl  Lo  itwlf,  it  asiunioa  wltot  may  be  called  the 
natural  posture  of  a  lro|{,  with  the  fore-limbs  erect  and  thchiri(t-linibedexed, 
•u  that  tlie  line  of  lh«  uxly  makes  nu  angl«  with  ibe  surface  on  which  it  is 
rtviing.  When  placed  on  il«  back,  it  im  met  timidly  regains  this  natural  f>as- 
tnre.  When  placed  od  a  board,  it  does  not  fall  frum  the  board  whtii  the 
]mUtr  a  lilteu  up  so  aa  to  dbplace  llie  auiinal's  centre  of  iiravily ;  il  cniwla 
up  the  board  until  il  gains  a  new  poution  in  which  iia  otntre  of  gravity  is 
Ratw^  10  ila  proper  place.  Ita  moveiuenta  are  exactly  ihiwe  of  an  entire 
tng,  except  that  tiiev  uev:d  an  cxienial  stimulus  to  call  rhem  furth.  They 
dillvr.  moreover,  fuii<{umeniully  from  thoae  of  an  entire  froj;  iu  the  fullowing 
iropocuuit  feature :  ther  inevitably  follow  when  the  lUmulus  is  applied  ;  they 
eOBM  lo  an  end  when  iheitimiiluB  ce«ae«  lo  act.  Br  continually  varyiug  ttic 
inclinaiiou  of  a  buunl  on  which  it  tii  pluceil,  the  frog  niav  be  uiaile  tu  OOD- 
linuv  crawling  almost  inde6uitely  ;  but  directly  the  board  i<  nmile  t»  assume 
■ucb  B  poaitiofi  that  the  body  of  tlie  fniir  i*  in  equihbrium,  the  crawlinjf 
ecaiaa:  aiid  if  the  {KNiiioH  l>e  n^it  diaturlwd  the  animal  will  remain  impassive 
Hul  quiet  for  an  almmtt  indefinite  time.  When  thrown  into  water,  ihu 
rivalure  liegins  at  onre  to  «nim  ntioiit  in  the  mo>t  regular  ninnnrr,  and  will 
foniiouv  to  swim  until  it  is  exhausted,  if  llicre  be  Doihiug  pn-Mciil  on  which 
it  caii  come  to  mt.  If  a  small  piece  of  wood  be  placed  on  the  water  the 
fh]|>  will,  when  it  comes  in  contact  with  the  wood,  crawl  upon  i(,and»u 
flone  to  rest.  If  disturbed  from  its  natural  posture,  ns  by  bcin^  placed  ou 
Ua  back,  it  immediately  slruf^gles  ta  ngain  llial  p^ture  ;  only  by  the  nppli- 
calioa  of  continued  force  can  it  be  kept  lying  on  its  back.  ^Sucb  a  fro|(,  if 
its  flanks  be  gently  stroked,  will  croak  ;  aud  the  croaks  follow  so  regularly 
and  surely  upon  tbe  sUokcs  lluU  the  animal  mav  aliiioet  be  played  upon  like 
a  musical,  or  at  least  an  MMMMic,  iustruuieut.  Moreover,  oruvided  that  the 
ofillc  nerves  and  their  artatwemeDls  have  nut  been  ii)jure<l  by  tlte  operation, 
tne  ■noTementaortbeanitualappear  to  beinflnenceil  byli^'hi;  ifilbeurf^ 
to  moTS  in  any  particular  direction,  it  iceuis  in  its  pro^rvos  to  avoid  obata- 
cio*.  at  teost  sucu  as  cast  a  stixiuj;  aliaduw  ;  it  tunui  its  course  to  the  riifht  or 
leA,orsoiDetimea  leajis  over  the  obsiaiele.  In  tiict.  even  to  a  careful  observer, 
the  (lilferenees  between  such  a  frvi)c  and  an  eutire  frog  which  was  simply  very 
stujiid  or  very  inert,  would  upfieur  nliKbt  and  uniui{>urtam,  except  iu  tlii^i. 
that  tbe  animal  without  iLh  cerebral  heuiiapheres  in  obedient  to  ever)'  stimulus, 
aud  that  each  ttimulua  evukw  on  ajipropnate  movemeut ;  whereas,  with  tbe 
ODtiro  animal,  it  is  imfMaeible  to  predict  whi-ther  aiiy  result  at  all,  aud  if  si> 
wbat  roult,  will  follow  the  applieatioii  of  tlits  or  that  Htimuluo.  Both  may 
bo  rvganleil  as  maohineH;  but  the  oiic  u  a  mnchiiie  and  nothing  niurv,  tbe 
otiwr  is  a  machine  governcil  and  checked  by  a  duminunl  volition. 

Now  such  ronvcmeni*  as  crawling,  leaping',  swimming,  and,  indeed, 
a*  va  lasTO  almdy  urgi-d,  to  a  grtaier  or  Win  extent,  all  bodily  movv- 
nieiits,  are  cnrrie<l  out  by  ni«iii»*  of  cni)rdinntu  nervous  motor  impulses, 
inOueaced,  arranged, an<l  p>v)Tnc<l  brcoineidcni  iriisory  or  aflerort  im pulses. 
MuBculor  movements  are  iletermincd  by  nHerenl  inllueiKOS  procoadiug  from 
ifca  noacU-s  and  couttituting  the  foundiitiou  of  iIk  muMular  seusa ;  tiey  arc 

Ut 


780 


THE   BRAIX. 


iil«o  ilifocled  by  means  of  nOVrenl  ioipukes  piMiiij  centripelally  aloOf  tlu 
fCDMiry  nerves  of  Lhei^lciii.  the  eye,  lite  ear, and  other  ur^iM.    Inij<>p«idiii[l| 
of  the  pnrticulnr  afferent  ini|itilM«,  whii'li  uetiuft  a-i  n  Mimalus  call  f»nk  lu 
muvi-iueot,  very  miiny  other  afrnretil  im{iul»eit  nre  couct-riM-il  in  t\»  pom- 
liun  and  oniirdinntii)n  of  the  renullani  iiuMor  impulto.     Kv^ry  ImhIiIv  iann> 
tuenl  Biirli  aa  thoee  of  wliirh  we  are  H|>eakinx  i»  the  nork  of  ■  nK>r*  or  In 
comiilicated  Dervoiiit  nieclianixni.  in  whii-h  iliere  arc  not  ouly  central  iiiJ 
eAerent,  but  alsi>  ntren-nt  ftietont.     And,  fnilting  nuidr  the  ijuivtion  of  nn- 
■riouBiieM,  frith  whk-h  we  liuvv  here  nn  occiisiixi  lo  deal,  it  i»  evidvni  ihsi  b 
the  frog  ijeprired  of  its  <«re1irai   lii-Tiiii'|ihi-mi  all  thon;  lactnn  air  | 
the  ufliinent  no  lew  ihnii  the  ci-utnd  nnd  tlif  clfurenl.     TIte  nuiehiort'  i 
the  Uf^eMKry  and  uiunl  lintlily  nutvcnH-ntu  in  {ircwnt  in  nil  it*  cimiili'iitirw. 
We  may  rei^rd  the  thnrv.  ihercfnr>'.  which  the  cen^liral  h«mi<>iiher<.-<>  uit  a 
cx<.-uultne  the  movvmciil^  of  which  the  entire  onimid  i»  c«|ittt>le,  a*  lhai4 
putting  uii»  miichinery  into  action  or  of  limiting  its  prcviuuii  activity.    TU 
reUilinii  which  [he  higher  nervous  choiigv*  concerne<l  in  volitioo  bcAr  to  lUl 
mnchinery  nmr  be  compared  to  that  of  a  EtiniiiliM;  uliniys  bearing  in  fninl 
ibat  llie  ('fleet  of  ft  slimulus  on  a  nervoiie  c>.iitre  may  be  either  ta  Uan 
activity,  or  to  inemM,  or  to  eurb,  or  to  »top  iicliviiy  alremly  prewnL    Wi 
might  almost  spmk  of  the  will  aa  nn  intritieic  fCimtilue.     Il»  operati-iot  on 
limitc<l  by  the  ninchinerv  at  itn  eommanil.     We  niuy  injur  that  iu  ibe  in^ 
tho  action  of  the  eerebrai  heniisplieres  in  giving  shi)|M>  tu  a  bodily  laoveranit 
is  that  of  thraiving  into  activity  pnrLleular  piiri«  of  ihe  nervous  nuieblncry 
Htuated  in  the  lower  pnrt«  of  the  braiu  and  in  the  spinal  cord ;  preciMlr  iIn 
same  moveraeiic  may  be  initialed  in  the  abaencv  of  the  cerebral  bemiipDmi 
by  applying  $iie)i  aliniuli  ua  nball  tbrow  precisely  the  oatue  parts  a  ikai 
luachincry  iiilo  the  oaine  activity. 

Vi-ry  niurked  la  tbe  conirust  ticLweea  the  behavior  of  auch  n  frog  wbk^ 
though  deprived  of  iut  <^e^L'brnl  heinupbftrei,  Btill  retains  the  iittu>r  partai^ 
the  brain,  and  that  of  a  fmg  whicli  poaseam  ■  tipinal  cord  iinly.  Tb«  UUii 
when  plooeii  on  ita  back  maki'!<  no  attempt  to  regain  it^  mirinnl  jxMluni;  ia 
fact,  it  may  be  Mitd  to  have  eonipletely  h»t  itA  normal  |HMtiire,  for  una  tthai 
pineol  OB  it*  belly  it  diK'.i  not  Nland  with  il^  foTe*fvcl  erect.  0*  dots  the  othft 
nnimal,  but  lie*  Bnt  on  the  gnxjnd.  When  thrown  into  water,  instnwl  if 
twimming  it  nnkM  like  a  lnnii>  of  lead.  When  pinehnl,  or  olhcrwim-  »liii» 
lated.  it  doM  not  crawl  or  leap  liiraard;  it  iiini])ly  tbruw*  out  it#  limlab 
various  wayf^  When  il<  tlank*  are  xirokeil  it  doei  not  crnalc  ;  nnd  niiraa 
board  on  which  it  is  plac4.'d  i*  inclined  Kulliciently  tn  difptacs  it*  centre  of 
gravity  it  makes  no  ctbn  to  regain  iis  balance,  but  tnWu  oQ'  tlie  boanl  likca 
IifekM  mast.  Thmigh,  as  we  have  m«i),  the  \-nri«us  part*  of  ibc  spinal  cord 
of  the  frog  contain  a  large  amoimt  of  ctmrdinaiing  nuicbinery.  to  that  tbi 
bniinlen  frog  may,  by  appropriate  stimuli,  l>c  mailc  to  execute  various  par 
jKveful  coordinate  movoiiienl^.  yet  th<'»e  arc  very  limited  compared  aitb 
those  which  can  lie  similarly  carried  out  by  a  frog  posMwing  the  middle  oaJ 
lover  purls  of  the  brain  in  addition  to  the  sjunaTcnrd.  It  is  evident  ibu  • 
great  deal  of  tbe  more  complex  machinery  of  thi<  kind,  specially  all  tit* 
which  bos  lu  deal  with  the  body  aa  a  whole,  and  nil  that  which  is  entttiuriMil 
WttJ)  e<inilibrium  and  i^  6[»ecially  govonutl  by  the  higher  senses,  ti  iraird 
Dot  ID  the  Hpinal  eord.  but  in  the  brain.  Wo  do  not  wish  now  to  dtM;ua>  iJic 
details  of  this  maeliinery  ;  all  we  desire  to  innst  apun  at  praami  b  tliol.  ia 
the  &og  the  nervous  uiacbinery  required  for  tho  execution,  as  distinifutthrd 
ftiini  the  origination,  of  bodily  movements  even  of  the  tnosl  cyMnplicnlcil  kind, 
is  preaent  after  complete  removal  of  ibo  cerebral  hemispheres,  though  tiim 
mnveoieuta  are  such  oa  to  retjuire  the  cooperation  of  highly  diffiuvatiaivd 
aflbrent  iinpulses. 


WITHOUT  CBHKBKAL    II  £UI3Plt  ERES. 


7S7 


\ 


{  640.  In  wmrm-liloodfil  aiiiiniiU  tlic  rrniovnl  of  the  cca'1>ra]  homUplicraa 
■ttcuditl  «ii(h  much  grciUr  'littiruttiw  ihnii  in  ihv  ciuw  of  tlio  fro^.  Nov«r- 
'  I,  in  tli«  bml  ihi'  (i[)cr>ti  in  iiiity  be  mrrietl  out  with  ftp|iroxtinntc  huc- 
Pisenus  for  iualfliice  huvc  l)C(iD  kept  alive  for  five  ur  six  wraks  KlWr 
cniDpleta  ivnxwul  of  the  (.■ervhral  hiWMWpbenw.  with  the  cxccpli')!!  of  portioui 
of  tne  cnira  and  corjtoni  strima  imfliMiately  surrounding  (he  optic  toitlanii; 
tbeM  |MiU  were  lelt  in  order  to  eiuurv  the  iotacl  voodition  of  the  lattcr 
IkkIw!*. 

Wheu  tb«  iiunifdiiile  «flbcle  of  the  operntinu  htiv<!  pnscd  olT,  and  fur  uaw 
Uiu«  alWrniird.  (he  apmaranoe  and  behavior  of  the  bird  Br«  alrikiii^lj 
•iiuiUr  to  tbuM  of  u  bird  exc«e'liui;Iy  el«epy  and  etupid.  It  U  able  to  itiain* 
tain  what  up|n:ar»  to  be  a  completely  normal  jxMlure,  and  c«n  balnuLi!  ilaelf 
wn  ouc  IcK.  ftfler  the  fo^hiuii  of  a  bird  which  has  in  a  natural  way  ^nue  to 
»)««]>.  Urh  aWe  iu  iierfed  (piiet,  it  will  remain  iiiipassive  aiid  mAlioulew 
Jbr  B  loD);  tiini;.  When  >ttirn.il  it  tuuvoD,  abifis  its  [Muitioo ;  and  then,  »ii 
ling  IcA  tlitne,  returns  tu  a  uutnral,  easy  posture.  Placed  i>ii  iiA  siib-  ur  iia 
ick  U  will  rcfpun  it»  feel ;  Ihrnwn  into  the  air,  it  flie*  with  conKiilerub'* 

Ervciitii'n  for  *oRi«  diotance  before  it  returns  to  re^t.  It  fri'ijuently  tuck*  il« 
rad  uDiter  its  wiDgH,  and  at  liitie*  mav  lie  m<vu  to  clean  iui  feather*  ;  whuu 
ii»  beak  ia  pIiiRK<.''t  into  corn,  it  euln.  It  luny  l>c  induced  to  move  not  iinly 
l>y  ufiliiiiiry  stimuli  applied  to  the  akin,  but  almi  by  ^tulden  hiud  sounds,  i>r 
bj  ttMbca  of  li((hl:  in  iu>  (light  it  will,  though  imj^ierfecllr,  avoid  obttuclos, 
MhI  it*  Tsriout  roovementv  iip|H^r  to  bo  to  a  curtain  extent  gnided  nol  only 
t  by  touch  but  ix\»y  by  visujil  iuiprMnoii*. 

V     III  a  certain  number  ut'coMt  ibi«  slMpy,  droway  condition  poMoioffand  is 

laacoMxlcd  by  a  phase  in  which  tlie  bird,  niiparently  «{K>iit«neously.  without 

■  the  intervention  •>(  any  obvioitH  iiliniulu»,  nixvcs  rapidly  about.     It  dixa  not 

I  At,  that  is  to  say,  it  does  not  raise  itself  from  the  ground  in  IliKhl.  but  walks 

"  a&oui  inottaantiy  for  a  long  while  at  a  time,  periods  of  activity  alternating 

Kith  periods  of  rejKMe.    It  iceniB,  fruni  time  i"  time,  to  wake  up  and  inove 

■hiut.  mid  then  to  g«  to  sleep  afiaiu :  and  it  has  been  observed  that  during 

tJie  ni^-ht  it  ap|>eani  to  be  always  asleep.     It  is  obvious,  therefore,  that  the 

•liTpy,  •(uieaeeut  cunditioii  is  nul  due  tinply  to  the  absence  of  the  carebntl 

bviutfjibrra,  but  U  a  tem|><>rary  effect  of  the  operation,  and  that  s|iontanootu 

BOTCaBCUta,  that  is  to  say,  movements  not  started  by  any  obvious  rtimuliu, 

may  ovenr  aAer  removal  of  ibe  cerebral  hemispheres.     But  the  luovemcnta 

sn  witnR«<^l  'lilTer  from  those  of  an  intact  bird.    Thev'  are.  it  i»  true,  varied : 

aiul  Ibe  varialii'hM  are  in  part  dependent  on  external  circum.<taitc«i,  iho  bird 

b«ii>g  vultled  by  tjii-lile.  and  sd  we  have  said,  viuial  seotttiMUs.  ur.  to  be  mora 

exact,  Dv  imprctiiiiUM  niud<:  upon  the  sensory  uurvesi  of  the  skin  and  on  the 

In-tina;  out  they  d^i  not  shuw  the  wide  variations  of  vo'.unlury  m'lvnmiriiU. 
The  bin)  never  llies  up  from  tbi;  (cround.  never  spootJtn  eon  sly  piclu  up  oora, 
and  ilanimliiui,  monolunouii,  rmtldj  walks,  rcnumblinz  the  continued  sn-im- 
tning  of  tJic  frug  thrown  into  tlte  water  after  being  deprived  of  its  c«n.>bral 
hvmispboras,  forcibly  «uggv«t  that  the  aoiiviiy  is  the  outcome  of  some  intrinite 
itupulae  generatvl  in  the  nervous  machinery  in  iu>me  way  or  other,  but  not 
bv  tbe  working  of  a  conscious  inielligence  as  in  the  impulse  which  we  call 

I  tbo  will. 

I  8till  we  mutt  not  shut  »ur  eyes  to  the  foct  that  Mpjnlonoous  movements, 
whatever  iheir  exact  nature,  arc  manifMtexl  by  a  bird  in  the  iibwnce  of  tlie 
cerebral  hcnii^jihcres,  and  )>eci>me  the  nnre  olnking  the  more  complete  the 
recovery  from  the  ptiutng  elfcol*  of  the  more  o|>er*tiiin.  Ciuld  s.ich  birds 
be  kept  alive  fur  any  considerable  lime.  (luMihty  further  dqvel')|inicnta  oiigbl 
Ite  witneawd,  and  iudee<l  cusw  are  on  r.icird  whore  birils  have  bsen  k-ipt 
ftlivc  for  moDths  after  llie  operation,  and  lisvc  shown  spontanoous  move- 


78S 


THB   BRAIK. 


mentsof  a  still  more  varied  charncter  than  ihoae  jiut  described;  twl  itttnA 
CBses  lli«  reinovat  of  tbe  bemiiptieres  has  not  been  coniplele,  [tonioos  of  ihr 
veolrftl  reeiniti  bein;;  leti  behind  ;  and.  ihoiij;))  h  iiioTe  ivtiinaul  left  ■nanj 
ihe  optio  thalami  ean  hardly  be  legnrded  as  a  sufScieut  rause  for  tbe  tpie- 
tSDcity  uf  irhirli  ue  are  ^iienkiiig.  a  larger  maM,  still  more  or  lav  ralwa^ 
its  Do'mat  etruclure.  might  have  a  markeii  eJlecL  Aod  we  may  her»m> 
bii[ia  remark  that  all  these  fhets  seem  to  puiiil  to  the  conclimion  that  nii 
may  be  called  meuhuiiicnl  Bponianetty,  sometimes  spokeo  of  as  "auiitmntlmi,' 
dillm  from  Ihe  &p(>iitaueily  of  the  "  will  "  in  degree  mtlicf  ilian  in  UtA. 
Lookiiif;  at  the  mailer  from  a  purely  physiological  poioi  of  view  (thttnlj 
one  vihich  has  a  ri;;hl  to  be  employed  in  ibeae  pag»),  ibo  r««)  aiflhftoct 
belwceu  an  automaiio  act  and  a  voluiitanF-  itei  in  ibui  tbc  rhiiin  of  iihttio- 
logical  evenis  hetwec-n  lliv  acl  and  ils  |diyaiid(>giud  niune  in  iii  (be  ow  or 
fliorl  and  Him]>le.  in  the  ulhcr  long  and  complux.  Wa  bnvc  men  that  a  fn^ 
bickin);  ila  cen-bral  heminfilieres,  viewed  fr»m  one  stand p<-irtt,  apjioiri  in  tkt 
light  iif  II  roechaoicat  npfiarntns,  on  wh{<'h  c«ch  change  of  eirrumilanon 
producn  a  direct,  nnvarying,  iiievitablo  efli^d.  Ami  yet  it  is  ou  rKonI  tkai 
such  n  frog,  if  kept  alive  long  eiiongh  for  the  mort  complete  dianpnorawt 
of  Uie  direct  cHl-cU  of  the  oiN'-nilion,  will  Imrj-  itself  in  the  cmrtli  at  lb( 
approach  »f  winter,  and  t»  able  to  calch  uml  swallow  flic*  and  olh«r  hoi 
coming  in  ils  ncighborhofxl,  allhougb  in  olher  respects  it  shows  no  Rgntof 
an  iiilclti(,'rnt  vuTtliou,  and  mtswrrv  with  unerring  mecbniiical  oenaiiUjrto 
the  play  of  ilimnli.  Wc  mnv  add  that  in  some  firhi^  the  removal  of  Ihi^ 
cerebral  heniii<j>bcrrs,  Hhieh  m  these  animals  f'irm  n  relatively  small  lort  of 
the  uhoIcbrniD.  produces exeetdtDglylitllu  change  in  their  general  iMtnivior. 

These. however. arc nol  thecunsiaerationE  on  which  we  wi»l)  here  to  dwell; 
we  have  qiioled  ihe  bchavinr  of  the  bin)  depnvi-d  of  its  cerebml  bemisphcR 
mainly  to  show  ibat  in  tbtf  warm-blooded  auintal,  n^  in  tite  more  IdwIv  cuU- 
blooded  frog,  the  parts  of  the  brain  below  or  behind  the  ocrclirnT  bemi- 
Bphem  conMilute  a  nervous  machinery  by  uhicfa  all  the  ordinary  bodili 
movemeuta  may  be  carried  out.  The  bird,  like  the  fbig.  sulfiT^  uo  poralya 
wbeD  the  cerebral  hemispheres  are  removed ;  on  llie  cuuirary,  though  ib 
movemeDla  hare  uoL  been  (tudied  »  clooely  as  those  of  ihv  Irog.  the  binl 
without  its  cerebral  bemis|)lieres  aeems  capable  of  execuliDg  at  nil  v^'enia  aQ 
the  onlinary  bodtly  movemeuts  of  a  bird.  And  in  tlie  hini  nr  io  the  frup. 
the  afferent  impubea  passing  into  tke  central  nervous  system,  whHherlkt 
give  rise  to  consciouwess  or  do,  plajr  an  iiii|)ortKiit  part  not  only  in  arigi- 
uaiing  but  in  guiding  and  coiinlinating  ibe  i-ircr«ut  im]>»lKii  nhicb  stir  itv 
muscles  to  couiriirt.  the  cin'rili nation  bemg  elfeete^l  parliv  in  the  spinal  cori, 
but  largely  and  in<leL-d  ehiclly  iu  ihe  |)art*  of  the  brain  lying  tichind  thr 
cerebral  hem  in  ph  ere".  It  \*  further  worthy  of  notice  that  spuntnueily  u( 
movement  of  the  kind  which  we  have  docriliid,  is  much  more  nromtneut  iti 
the  more  highly  developed  bird,  than  in  tbe  more  biwly  fmg.  The  cerebral 
lieniiephcres  are  not  the  only  part  of  the  central  nerAouK  nystcm  which  hu 
iiDdcrgonc  a  grcuter  development  in  the  bird;  the  other  parts  of  tbe  brain 
have  also  acigiiired  ii  fiir  greater  complexity  than  in  Ihe  fmg. 

^641.  Id  the  mommiil  ihe  removnl  of  ihe  cembml  hcmispbcrce  ■  still 
more  difficult  than  in  the  bird;  the  animal  cannot  bu  kept  alive  fbrmnrr 
than  a  few  hours;  but  in  some  nuimmalu  it  is  pvmibia  to  obserre  dtiriue 
those  few  hours  pbeuomcnn  kindred  to  those  nitntased  in  the  bin 
aod  in  the  frog.  The  rabbit  or  rat,  from  which  the  whole  of  both  hemi- 
spheres has  heen  removed  with  iho  execption  of  tbe  parts  iiumcdialely 
Bumiunding  the  optic  ihalami,  van  stand,  rvD,  and  leap.  I'iaced  od  its  tide 
or  back  it  at  once  regains  its  fcM.  LeA  alone  it  generally  remains  as 
niutioulera  and  impnesive  as  n  statue,  sure  now  and  tbeu  wheii  a  [>anii)g 


TTITaODT   CBRXBRAI.    REMISrHBRES. 


ipulw  BMiM  (o  tilir  it  to  H  iiidili-u  but  britif  mnvement ;  but  *oractiniot  it 

Mcms  mbtMt  to  n  morv  ountimicd  iiii|m'iii;  hi  niuvo.  iu  vrliiirh  caM  dnith 

WmtanjfommTery^fttAilf.    Budia  rabbit  will  remnin  W  ininiiln  u«vtli«r 

niUrlT  hveillMs  of  k  mrrot  or  cabbHf:«F-Imr  pliuv^l  ju*i  befurv  il»  mwe.  ihiHigb 

tr«  tnnrMl  Iw  placci)  irilliin  iu  moiitli  it  nt  4iicc  bl^gin*  to  cat.    Wlwn  atirn^l 

it  «ill  with  omm  nni)  KimlinvM  run  or  leap  roraiiH;  nml  olwUcIc*  in  its 

coun*  an  varj  fmgurntly,  with  mure  or  Ivn  taccan,  avutilrH.     In  »i>mi.-  cium 

tbr  aninul  (ni)  ba*  bmi  described  m  follonin);  br  inn\Tm<'nt»  of  the  h«wl  ■ 

brijflit  \lgln  )iH<l  in  front  of  it  (urovided  tlint  tbc  o[>liL-  ncrrw  and  tracts 

hna  jHt  hw)  itijnrcl  during  tbo  operation  \.  m  nlnnini:  when  it  «bril1  nnd 

HNd  nciN ll  naik'  ncnr  it,  and  ii«  erring  vrbcn  pinclKil.  often  witb  ii  too^  nnd 

ncemiogl;  pinintivo  scfMii.    So  pUiniivc  U  tbo  cry  which  it  thus  girca  forth 

Itai  to  •n^'gisl  to  the  ohae<ri-er  tb?  cxiitcncc  of  {n«i<>n.  this,  hovrover,  ii  jirob- 

■  My  K  wnmj;  inleqtretation  of  a  tocuI  uclion  -,  ihc  cry  nppeKrs  plaintive 

limplr  bccaiiw.  in  eoiueqaenre  of  the  coiuplctcncne  of  ihe  reRoiE  nervous 

Iaiarbincrr  and  ihe  ubsetioe  of  the  usual  netraintJ,  it  is  proloni>od. 
Without  instsling  too  much  on  sucb  results  as  theec,  and  alloirini;  full 
wpigbl  to  tbo  ohjecliiin  which  may  be  uived.  that  in  (onie  of  ihew  coses 
part^  of  tbc  rercbral  hciuispborM  uirrouniiiil];  the  optic  thalaroi  wrv  left, 
llwre  still  remains  adequate  evidence  to  show  that  a  mamnial  such  a*  a 
rabbit,  in  Ihe  same  way  iks  a  fnig  '"'d  a  bird,  may  in  the  cuniplele  or  all  but 
roplete  absence  of  the  cerebral  bemiaphem  maintain  a  nnlural  posture, 
frooi  all  aigna  of  dttturtiaiice  of  e<)uilibriuni,  and  U  able  tu  carry  out 
ilh  auccaag.  at  all  eventet  all  the  ususal  and  commao  bo-lity  niaveiiienis. 
And  as  in  tbe  bird  and  fr»K.  the  evidence  also  showd  that  theae  nmvetueuU 
Dot  only  Diiiy  )>e  started  by,  but  in  ibeir  varryinji;  out  are  guided  by  aud 
rdinated  by  afferent  iiupuliNSi  aliinj;  aflenml  nervea,  iueludin{(  tlMMeoflh* 
'  MiiK*.  Rut  in  the  cjise  <tf  tho  rabbit  it  Ik  even  ittill  cleuor  than  in 
am  at  th«  bird  ihnt  tbc  oflcda  of  lhi.i«c  atrvn-nt  inipulgw  are  ditfomit 
Jron  thoK  which  rtwilt  wbon  tbe  impiilxr*  gain  aci-cm  to  an  intact  brain. 

BjDovemcni^  «f  (he  animal  seem  guided  by  iraprcssion*  mndc  on  its  retina, 
III  as  on  'ilhcr  scuuiry  nerves ;  irc  luiy  perhaps  speak  of  the  aoimnl  as 
Milijnct  of  spnsniioiis;  but  ihcrv  is  no  satisfactory  cvi<lcncit  that  it  |>os- 
■  either  visual  or  other  perceptions,  or  that  tlic  fcnrations  which  it  ex- 
pwtema  gives  riw  to  idcti».  \u  avoidanou  of  objvols  depends  not  so  much 
on  tlM  (om  of  thmc  as  on  their  iutcrfereoeo  with  light.  No  image,  whe<tber 
pleasant  or  terrible,  whether  of  food  or  of  an  enemy,  produces  an  effect  on 
U,  other  thnn  that  of  an  object  reflecting  more  or  less  linht.  And  we  may 
infer  that  it  locks  the  possession  of  an  intelligent  will.  Uul  it  must  always 
be  renwrnlKTcd  that  some  of  tlie  phenomena  are  due  to  tlic  operation  pr\>> 
dudoR  other  results  than  the  mere  absence  of  tbe  part  removeu.  We  ratut 
bear  in  mind  that  in  all  theaboveexpenntenla  while  the  positive  phenomena, 
the  things  which  Ihe  animal  c^mlinues  able  to  do,  are  of  great  value,  lh« 
pegativc  pWoomeoa.  the  things  which  the  animal  can  no  lunger  do,  are  of 
much  lew.  iwieed  of  doubtful  value.  The  utorv  carefully  and  sUOceoBfully 
|li«  uperinwDls  are  i-arrie>I  out.  tbe  narrower  become  what  ne  may  call  tbe 
*d«fiaCDcy  pbenotnciia,"  the  pheDomena  which  are  alune  and  directly  due 
to  aooiething  having  been  taken  away.  Were  it  puasible  to  keep  iliu  mbbit 
alive  long  enough  lor  the  mere  elfccts  of  tbe  operation  to  poas  e»m|dH"Iy 
amy,  we  atiould  not  only  probably  wilnew,  as  iu  the  case  of  thi;  tiini,  » 
greater  scope  of  movt^ment  and  niort  frequent  •[lontancity,  but  |)iM>ildy  lind 
~  dillicullv  in  describing  the  exact  condition  of  the  animal. 
i  642.  tiilliertu  uttempu  to  witiioa  similar  phenomeaia  Id  mom  highly 
inimi  mammals  stich  ns  the  dug  have  faile4l ;  iheao  animnN  <lo  not 
frora-the  operation  of  removing  tlie  whole  of  billi  ibdr  humispbcro* 


rfto 


TIIG    BBAi:e, 


Miffi<ri<^tl7  to  €Diili1e  Hi  to  jiiHge  Kbclber  (bey,  like  tht  freg,  Ae  hM.  tot 
the  rabhit.  mil  cam-  mil  i-oonlinalc  Ixxlily  luovenietiti  is  ibe  •iMMS^ihc 
beii>i»|>hrro,  cr  ulteilicr  in  tlieiti  lliw  jwri  of  ih«  lirun.  so  lufrlj  A i i^f  14, 
hm  utiirpid  fiinctii.nii  nliuh  in  lb«  lower  inimala  bdon^  tsMfer (wn 
Our  kDonltdffe  is  lHT),t'lv  criiit>ne<l  ii>  the  px|i^ricnr«  ihu  «wa  li  kdaf  At 
ceicbnil  convolulioiig  nre  rrnidvei)  lierenml  it  MTtfml  a) aniwi,  tk 
aoiiDul  may  be  kept  altve  Rod  iD  kocmI  li«attli  for  e  Iouk  (Jne,  wmMf  mrtlkt 
Bt  lenvi,  e^'^n  aDer  ih<-ie  pans  «r  ibe  brain  havr  bmn  rnjund  t4>  nfjoHll 
diinenriuna,ai)d  tbat  under  i1ie«e  i-trctini»tBmt«  ibr  animsl  '»w*i^Mi 
to  carry  out  ntth  wme  limiliilinni  hb  txditinrir  bodily  mntTtoFOti^  Ml  ife 

exbtbita  a  tiponiaii«iiy  vbvkiuily  betukfning  tbt^  ptDwikioi)  not - 

couwiuiu  Tulitii'D  hut  of  a  cvViain  amount  of  iuldliccocc^  I 
KJIIinfc  to  Wlkve  ihnt  a  nirrc  fnigoM'nt,  ki  to  Mfnik,  uf  thv  iMtDnpcwrn  ni 
take  on  n>o«>t  cxlnidrd  iiontr*,  lucb  nn  oxprrirncr  ■mn*  to  tlxnr  llm  iail* 
dog  It*  in  lb<-  riibbit  and  in  the  bin),  ibt^  dmlopawnl  of  M>«alM  Uf^ 
fonclioDs  i*  not  limitt^d  to  iW  crn-brgl  hrmiapbnT*,  tbat  ti»andAmi 
\ovctr  portion*  of  lh«  bmin  in  thr  bighrr  animRlt  bk  co«Bimrt4  «kk  iki 
lower  do  not  iocmisc  in  bulk  mvroly  n»  ttie  ii)ftnim<nts  of  ibr  htaitfk»m, 
bul  like  the  hcmiiplicrv*  ncgnirc  more  nnd  mure  oomplpx  fuixtioMi  V| 
niny  perhnjis  go  so  t'nr  a»  to  atk  lliv  '|U(«ti^i  vbcthtr  the  vvlitv*  md fakt 
li];t^nce  nliirb  sudi  a  dog  «sliibilB  is  nt>l  as  luuch  the  product  of  ibtfam 
lyiiiv'  behind  the  bcniif^plicref  as  of  the  !lunip  left  in  ibe  fniBU 

II  ve  csn  thus  say  little  about  the  condition  of  a  d'j^  nitb-i<tl  iW  canbrij 
beiDi«pber»,  Ke  can  say  still  leva  about  the  toonkey.  ithicb  ia  all  aaum 
toui-biuR  the  cerebral  nervooia  syelein  aervtt  as  our  hm,  tadt«4  MV«*^ 
fpiide  fur  dra«iug  inference  coucerninf;  man;  but  in  all  profaafatlity  4i 
innnkcy  in  ihio  reaped  bearv  nunieiA  liai  ili«  Mine  reluiimi  tu  lac  dog  lul  ik 
doK  btani  to  (be  bird. 

In  sliort,  the  more  wc  study  the  ph«Domena  vxliibited  by  aDinak  pcan- 
iiig  n  part  only  of  their  brntn.  the  cliwr  uc  are  pii*lM><l  to  ibe  or  ' 
tbat  mi  shant  lino  can  be  dniwii  l>clwc<'n  volition  nnd  ibc  Ui-k  of  ' 
or  between  liie  [wufsfwioii  nnd  nVisence  of  ink-lligcnce.  Bclwi^n  (ht  ttox  '■ 
ftene  prepnralJKU  at  the  nne  limit,  and  mir  n.'ne(-inuf  willing  ttlmailbf 
oibcr,  there  is  a  continuous  gradation  nithoul  a  break  ;  we  aoaat  (i  *■ 
any  linear  Itarner  iu  the  bruin  or  in  the  general  n^-rrnnt  trft»m,ni»} 
"  ''fy^")*'  <'''"  tben-  h  volition  and  intclli;^>iicc,  but  up  to  thb  ibvrr  ii  •«&* 

Ink,  however,  is  not  llie  (|ueflii<in  with  which  we  are  now  dealing.    Vht 
we  want  to  point  out  h  that  in  the  higher  atiimals,  iocltiding  at  ImM  am 
miimninb.  a*  in  the  frf>j(.  uller  tbe  renioviil  <if  the  cerebral  heinispb*rM  fnt 
tliougb  roDMloiia  voliliim  and  )nlelli;;en(-e  appear  to  be  Iiir^ely,  If  i»>l  relin','. 
lo»1,  ibo  boily  b  Kill  tujiable  uf  exeeuiiug  all  the  onliuary  luovemm!*  ak^l 
the  animal  in  it*  mttunil  life  is  wont  to  jHrf  >rm.  in  i]tite  of  ibene  murtmrti'.' 
Docoaulating  tin; ''i>rij)erati';n  of  vnriotu  affertul  impulses :  at>il  i^>i  il-rr 
foro  tlio  iK-rvMi»  Riacbiiicr>-  fur  lli«  csecution  of  thfse  movii 
•nnif  part  of  the  brain  other  thnn  the  rttrebral  hcmiif^ere».     W .  .1 
•ons  ^ir  ibinking  that  it  it  liiiian.-d  in  tli«  ttrudurea  foriiiiu)E  thi 
nnd  himi  brain ;  lu  wc  iiball  rec,  interfen-ncc  with  tbne  parts  pruiutT-  •■ 
once  remarkable  diiNtnlcre  of  movement. 


The  Mactii!iert  op  06BDi».vTEt»  MovmnKiti. 

§  643.  We  may  now  direct  our  attention  for  a  while  m  s.ime  «m»»ili-  > 
ninc«nitng  the  nature  uf  tlitt  complex  nerrou^  muchiner^'  fur  (be  O' 
Mon  of  bodily  moveinentB,  and  m|m'tally  concerning  lh«  part  playtil  "! 


TUB    JIACHINKHV    ar   COORDINATKI)    MOVKUKSTfi.      701 


impulara.  MoBt  of  <nir  Icnoirleil^e  on  this  pMOt  bu  bccti  ga!rieil 
[by  N  ttudjr  of  uiiouilft  not  ili'|<rivei)  of.  bui  f.il\\  pttetming,  their  c^i^bnl 
0«n)M[ilivr«A,  or  by  dnluvtiont  from  the  data  vf  uur  own  exprrinice ;  Imt  it 
p  pcwsible  [n  nuat  cum  to  eliiniuntc  from  Ihe  total  rojutu  the  ptietinmefla 
<Mliii-li  arc  due  (<.i  ibe  morkirig  nf  u  oimiciriiis  inielliKenoe.  Buine  ul'  the  ntoet 
■thkiiif;  lactn  lieuriiig  tm  ibi*  niiiltcr  bave  been  tcained  by  studyint;  tlte  dfecU 
'  ofM-ntttvf  tiitcrfeicncv  nilh  ccrliiiii  |>urt9  ufthe  rtileninl  ear.  known  v  tli« 
(dtrular  Cttnal*.  Tbe  dctniU  ui'  llic  ntruiturr  o(  ilie^  |Hirts  nc  nliall 
ibo  Inter  on.  wlieD  vr«  txtaie  l<i  deiil  ultb  bcariuji^.  but  we  riiay  hen  aay 
iluil  Mch  internal  eiir  pouMMtes  tlireo  membruouuii  oemii-iri-iilar  canaLt,  dit- 
ned  in  tlie  ihrcL-  pluDiv  nf  i>|iaM!  (»ne  bitrizoutnl,  and  one  in  each  of  the 
,wo  vertical  plani^,  fun  nud  utl  and  Hide  to  tide),  eavb  meinliranoiu  mual 
iMine  •umiuiiili'd  by  it  bonv  ciuiid  of  niairlj  th«  Mnie  flinnc.  nod  being  ex- 
||mndrd  ol  one  <'nd  inii>  wlint  is  vnllnl  an  nnipulla,  on  irbich  fibm  of  tba 
■udilorT  iHTvr  end.  Kui-h  nieniliranmis  canal,  in  cvminon  vilb  the  envity 
•f  tbo  intiTniil  i-sr  of  nhi^h  it  is  a  pr >In illation,  coatiuna  a  Hniit  ullini  to 
|yRi|ih,  callol  rn'lolyinph.  and  the  »|>aor  tH'twii-n  each  menibranoii*  canal 
mm]  tt»ci>rra{Kin<line  bony  canal  is  in  renlity  n  Ivmphnpnec  contuininj;  a 
Ruid  whieb  is  virlually  lymph,  lh(iOf;h  it  ie  called  by  the  «DCcial  nnnie  of 

Jn-rilyniph.     In  birds  iolerfc'rence  with  Ihe  •emicireular  cnnals  (iroducus  tho 
ullonin^  reiTiiirknblc  remits : 
I      WlH^t  in  a  |>i^'««m  iho  linritontal  membnuuHis  Mmieircular  cnnal  i»  cut 
|tbru«i);h.  tlw  bir«)  is  »b*erveil  to  be  coDtinuallv  moving  Us  head  from  side  lu 
ikitle.     If  une  of  the  vertical  canals  be  cut  through,  the  ni-ivenientf!  nn-:  uu 

Ed  duUH.  Tlie  peculiar  movements  may  not  be  wiincnfcd  when  the  bird  is 
rfoctty  (piict,  but  they  make  their  sppenriincc  whenever  it  is  disturbed  or 
kmpt<i  iu  any  way  to  stir.  W1il-u  the  injury  is  eonlinoil  to  one  cnnal  only, 
|«r  even  to  the  canali  of  one  side  of  the  bead  only,  the  condition  lUler  a 
Iftthile  |ttMes  away;  when  tbe  eunalt  of  both  tides  have  been  dividetl,  it 
becomea  much  cxaegenite<).  iatts  tiiuch  longer,  an<l  in  some  ca»<s  »  nuid  to 
rrunain  |)ermaiiently.  AlW  such  injuries  it  iti  found  that  these  jievuiisr 
[movetnctits  of  the  htriui  are  asHieiattHi  wtlli  what  ai)|]Cars  to  he  ii  great  wnitt 
Itif  ctntnlinuiiiin  of  botlily  niovemttnlfi.  If  the  bin!  be  tbmnn  into  the  iiir, 
lit  llulteni  and  lalls  down  in  a  hclplvn  itnd  coufuHw)  niimner;  it  np|H-iin>  to 
hi\«  lost  tile  [Kinrur  of  orderly  (light.  If  plii(-«<il  in  a  liaUni.'ed  {Haiiinii,  it 
nay  remsin  for  «»■>■'  time  iiuiet,  grncritlly  with  il«  licnd  in  a  peculiiir  jnm- 
|UI«:  buLdir4.<ct]vit  i*  dtitiirlHnt,  the  niov<.-rnfnt--<  which  it  alteTngita  tocxocuia 
sra  imfCiiUr  imd  full  xhurt  of  their  [Hiquw.  It  hiw  ({real  ditEciilty  in  |MCk< 
Ii^  ui>  food  and  in  <trinkinc :  and  in  gciicnil  iis  Itebaviar  very  niuob  rescm- 
mm  that  of  a  penon  nho  is  «xocedingly  diiixy. 

It  can  bear  perfectly  well,  and  therefi>rt^'  the  »ympt'inii^  cannot  bo  rvgurdcd 
•a  the  remit  of  any  abnormiil  anrlilory  sen»ntiun».  such  a«  "  a  njnriog  "  in 
Iba  «an.  BesKlcs,  any  such  stimulatiun  of  tho  auditory  nerva  sa  the  le^tilt 
•r  Ibaseetion  irould  f])ecdily  die  away,  whereas  thcMi  pbcftomaiui  nay  lost 
for  at  least  a  very  consiilerable  tima. 

\  The  nmvemeuLs  are  not  occasioned  by  any  partial  ]«^Blrsi^  by  any  Hant 
of  |Miier  iu  particular  luuacles  or  group  of  muscles ;  though  removal  of  the 
canabvf  one  si<I«  has  be«n  dateribed  as  leading  to  dimiuisl»ed  muscular 
force  DO  tbe  same  side  of  the  Iwdy.  the  mere  diminutioa  of  force  b  insuffl- 
I  ciciit  tt>  explain  the  plwuoniFua.  Nor  »u  Ihe  other  hand  are  the  movements 
idue  to  any  uncoiitnillabic  irajmlsei  a  very  gentle  preosure  of  the  band 
■ufficca  to  ttMi  tbe  inoveiuenia  nf  the  bead,  and  the  hand  in  doing  so  experi- 
COcaa  noatraiB.  The  awixintut!  of  a  very  slitiht  sujipurt  enables  movements 
etiMmEBe  impombleor  mutt  iliHieult  to  lieeosilv  exevuied.  Thu«.  llioogh  nhen 
laft  aU«e  tbe  bird  has  gn»t  ditliculty  in  drinking  ur  picking  up  corn,  it  will 


792 


THE  BBAIIF. 


rnniinue  Ui  <M  willi  r«M  if  ita  bosk  bv  plunged  inO  trnlrr  or  into  ■  bMp  rf 
biirli'v  ;  thi;  iiliijhl  stipjuirt  of  th«  vtntcr  or  of  the  grain  tf*fM  MlSehni  h 
MfBilr  ila  niDvcnicnrs.  In  tbc  miDO  vnr  il  can.  «ven  wi[h<>ol  H»iUiD(t. 
ciL-na  it»  fenthcre  and  ecrnich  tix  hmd,  its  beak  and  foot  beisj;  in  that 
operation*  giiidrd  bv  contiict  wiib  it»o«n  body. 

The  amount  of  diaordvr  thu«  induced  diflbre  in  different  birds,  and  hw 
mownxwU  ara  mon  affiwted  thnn  otbon.  As  a  g«^npral  rule,  it  mar  be  mH 
that  the  more  complex  and  intricate  a  niovement.  llie  IViller  and  aon 
doiicuie  the  coordination  needed  to  carry  it  out  succeMfuIly,  ll)«  mm 
markedly  u  it  disordered  by  the  opcmtion ;  tbu».  after  injurv  to  the  oaU, 
while  a  pigeon  caniiot  fly,  a  eooee  ja  tflill  able  to  awioi. 

In  Duunmals 'rabbits)  lectioDs  of  tlie  canals  aboproduoea a  c«nniii  amoiA 
oT  lonofooordinalion,  but  muoh  leaa  than  tliat  vitnesMd  in  birib;  aaJ  lb* 
inovenieiits  of  the  head  ar«  not  m  niDrkeil,  peculiar  DarillHtiiig  monfocall  of 
the  eyeballs,  dilfi^rinK  ■■>  direciiuu  and  character  aoconlinit  to  the  canal  or 
rfltiaUojieraled  upon,  beeomiti);  however  prominenL  In  tho  (nrgaaini^ 
titina  of  the  head  are  seen,  but  there  '»  »omeI<«sof  coiirdinaiioii  in  tbeiMT» 
mentsof  the  body.     In  fishes  uoefiect  ul  all  i^  pr»duc<.-d. 

Injury  to  the  buny  canals  aloao  is  iudufCrieiit  to  prciduce  the  arnptaw. 
thf  iiiembniU'iUK  raniilii  themselves  inu.it  he  divided  nr  injunvl.  Thr-  clisnc 
tcriirtio  movements  uf  the  hand  may  hnivever  hi'  hniught  about  in  a  biiil 
vfithoitt  opening  the  bony  canal,  by  stiddunly  hrating  or  ooolinjj  a  caoal, 
citjHvially  Its  ninpullur  temiinationii,  ur  by  tht>  making  or  brealliitg  of  a  oun- 
6lant  I'urrcnt  directed  through  the  runat. 

Then?  can  bv  no  doubt  that  the«e  chantctt.'iriHtic  movements  of  the  head  ai» 
tlte  result  of  alTerciit  impulsns  started  in  the  nervous  eiulingc  of  the  andiliiij 
aervfl  over  the  ampulla  of  the  canal,  and  conveyed  to  the  brnin  ahmg  thsl 
oervB.  And  thai  injury  to  or  other  stimululion  of  each  of  the  three  canah 
abould  prtxluce  in  each  cnse  n  dillcrent  niovcnient  of  ihe  head,  the  rlirertioa 
of  the  moveuienl  bein^  diHereui  accordiu);  to  Ihe  plane  in  which  the  i!BJmI 
lii.'M.shriws  that  these  impulses  are  of  a  peculiar  niiture.  Tliis  is  futiher  illiu- 
Irair^l  by  the  fullowinfc  experiment.  If  the  horizontal  canal  )>e  rarefully 
laid  bare,  and  the  membraDoua  canal  opened  so  as  to  ex[H»>e  the  eiid'>lynipb, 
b'owioz  giMitiy  over  the  opened  canal  wiih  a  6»e  >;laM  cauula  Kill  prmluo 
n  definite  movement  of  the  beoil.  whii^h  i&  turned  lo  the  one  side  »r  to  iW 
other,  ac«or<line:  as  tlie  cutretit  of  air  drives  the  etidolyniph  tuwaitl  or  awiT 
from  the  nm|)uTlu.  From  this  it  is  inferred  thai  a  movement  of  t)»e  endo- 
lymph  over,  or  an  increased  prtssure  of  the  endotymph  on,  the  nervous  end- 
ings in  the  ampulla  gives  rise  to  aflcrenl  impulses  which  in  sonic  way  ddcr 
mine  the  issue  of  efferent  impulses  lc«iliug  to  tJie  inuvenient  of  tlio  hroil.  It 
is  further  suggested  tlint  since  the  phun-s  of  the  three  canal*  Itc  in  tlie  tlirse 
axes  of  space,  anv  change  in  Uic  position  of  tlie  head  miiM  lead  ti>  obangta 
in  the  prcwnre  ot  the  cndolym|>h  on  the  walls  of  the  ampulla'  or  to  more* 
DKOts  of  endulvQiph  over  those  walls,  and  mi  must  give  rise  to  irainilpn  pav- 
ing up  Ihc  auditory  nerve  ;  and  thai  sinoi;  cvory  change  of  jvHition  will  ufTvct 
the  three  cannU  difliirently  'nhemw  the  change*  of  proMure  of  lb*  rtulo- 
lymph  involved  in  a  "  witvc  ofxiund  "  will  afloct  all  throe  ampulb<  equallr) 
those  impulses  will  diHl'r  according'  to  thi^  direction  of  the  chaoee.  A  Still 
further  extension  of  this  view  gu|ij><>«e:>  thnt  sinoe  in  any  one  position  of  the 
bead  the  pressure  of  the  eixlolymph  will  differ  in  the  three  ampulhe,  m«rs 
position  of  llie  head,  ai^  <li«tinKui>ihcd  from  cbstigv  of  position,  is  ade<{Uat«  la 
getierate  afferent  impoloes  diHi-ring  in  the  different  pntitions. 

Let  tis  now  for  a  while  luni  aside  to  ourwivos  and  exnmino  tl>0  CoHfdid 
tioii  of  the  niovemenls  of  our  own  bodies.    When  wc  appeal  to  our  ui 
sciotuoiess  we  find  ibat  our  movecnents  are  govorawl  ud  guidod  1: 


THK    HACIII.VKRr    OP   COdRDIKATEU    MOVEMENTS.      TfiS 

«*  niaj  mil  satDW  of  eqiiilibniini.W  nn  nfipnvinlion  of  Uii'  [HMilW  of  our 
Wly  and  ris  rektioDs  to  spnce.  Wlicn  tliU  mrw  of  oqiiilihrinni  i*  dixtiirbiHl 
wr  mr  wi>  are  ilizzy,  and  w«>  then  tttigger  and  reel.  Wing  no  longtT  able  to 
RHinlinatp  Ihe  nHivcntfiitH  of  our  bodicfl  or  to  adapt  lh«ni  to  the  p<mti->ii  of 
things  around  ub.  What  is  the  origin  of  this  iense  of  rquilibriiini*  By 
what  nicans  are  we  able  to  appreciate  the  poHilion  of  our  body  ?  ThcfV  can 
U>  no  duiibt  ibat  this  appreciation  is  in  Ut;r«  nieaauK  the  product  of  ¥■*»»] 
nod  tnrlile  Hmiitttiuni ;  ire  recognize  the  relatiuns  of  our  bndy  to  the  l-hin^ 
around  u«  in  jtreat  measure  br  sifcht  and  totieh :  we  alito  Icarn  inueh  by  our 
muHuUr  ceoee.  But  there  b«or»«thint;  b«»id«a  theee.  Neither  siKht  nor 
tou<-h  nor  nutoular  kom  can  help  us  uhen,  placet!  perfectly  Hat  and  nl  rest 
»D  ■  lutrisontal  rotating  table,  witJi  the  ey«s  f>lmt  and  not  a  muscle  stirring, 
««  atiMi)|4  to  determine  whether  or  nn  the  table  and  we  with  it  are  being 
tmiTexl,  or  to  ascertain  hnw  much  it  and  we  are  turned  to  the  right  or  to  iho 
left.  Vet  under  auch  drcuniii(aiu-««  we  are  cnnscioiu>  of  a  chanj^  in  our 
pneittoD,  and  some  ab«erveni  have  b«en  even  able  to  pose  a  tolerable  sucoeaa- 
All  jud|[nieiit  aa  to  the  angle  tlirougfa  which  they  have  been  moved.  Tliere 
can  be  no  doubt  that  meh  n  judgment  'a  biuted  upon  the  interpretation  by 
ooaadoaaneMof  siRirent  impulswwhioh  nrt-  dupeiideiit  on  the  p(«ition  of  the 
body,  tint  which  are  not  alU'rcnl  inipuln^  Ix-limgintr  to  Mcnuilion^  of  touch  or 
wht,  or  lakinjf  pari  in  the  mnitciilur  M'no:.  And  it  in  uiyed  with  ureat 
plauitbilitr  that  the  atrm-ni  impulwx  in  •{uwlinn  arv  th(4ito  which  we  have 
ju«t  rtfi-mvl  to  a*  ftartLiI  in  the  f^miciix-ular  I'nnaU. 

If  ni-  ailiiiit  ihf  i-xiM(-u<v  of  Kuch  a:n{ni]Inr  impiilw'V.iru'v  may  renttire  bo 
to  call  ih«ni.  and  nii>):niEr  thc'm  iiai'ontribiiting  largely  not  only  to  uxr  direct 
ttcrceplton  (if  lli«  pofjiinn  of  the  lu'ad  and  thn»  of  the  bixly,  but  alvo  in  ii  more 
indirect  way  to  what  we  linvc  called  tliv  iV'niw  of  tijtiilibriiim,  we  »liottld 
•iperl  to  find  tbut  when  tltcy  nrv  abnormal  the  acnte  of  etjuililirium  ii<  ditt- 
turbfd,  and  that  in  coosequeDce  a  failure  of  coordination  in  our  movemeata 
mulls.  And  the  Io«e  of  coordination  which  we  described  above  a*  rt!>idling 
from  injury  to  the  aemicircular  canals  has  accorrlin}>Iy  been  attributed  W>  a 
dsficieocy  of  disorder  of  normal  am|Millar  impulses. 

But  vc  must  here  disiint^uisb  between  two  thin(i:B.  It  seems  clear  that 
wh*n  the  membranous  ciinala  are  injured  or  otherwise  ttimulated  nlfereiit 
tnpulsea  are  generated  which, on  the  one  band,  may  produce  [veciiliar  more- 
menti  of  the  head,  and  on  the  uiher  hand,  teem  able  when  the  injury  is  largo 
lo  eauaea  loeaof  coiirdinatiun  of  buddy  movemeuta.  But  it  do««  not  necea- 
•arily  follow  ftnin  thu  that  in  a  normal  omdition  of  thiniT'  alftreni  iminilan 
are  continually  pasting  up  lu  the  bmiu  from  the  semicttctilur  canals,  am) 
that  (be  low  of  codnlination  which  tiillowt  upon  injury  to  ilic  canals  b  due 
lo  theae  nonnal  impulxs  henij;  deficient  or  altertnl.  It  may  he  that  such 
normal  impulses  do  not  exist,  and  thnl  the  lotn  of  ciiiirdiaaiion  in  the  result 
of  the  central  raacliiner)-  fiir  cudrdiiuuion  tieini;  inti'rferisl  with  by  '(uite  netr 
imptilaea  gencraled  by  the  injury  to  the  canal  with  the  conNCquttot  Im  of 
endolymph  acting  as  a  ttimulu*  tu  llio  endings  of  the  nerve.  For  llie  expe- 
rience <|uoli-d  iilmve,  though  it  provM  that  afferent  impuW*  other  than  those 
of  MgUl.  touch  and  the  muKcitlur  tcn«c  do  n'ftcli  the  brain  and  aflim)  a  biiM* 
fur  a  iudgmenl  lut  to  the  puiiitiun  of  the  boily,  don>  nut  by  ilavlf  prove  that 
thoM  im|)ul*ni  come  from  the  lemicircular  canal*;  the  arrangement  nf  the 
canals  is  undiiubtc>lly  *ugi[c»iive ;  but  it  it  (luiio  jKitoiihlv  that  the  afleroot 
impulara  in  itur^tiun  mny  Ix-  generated  by  one  or  other  of  various  obangaa, 
Tommotor  and  Otberw,  of  the  tnaucs  of  tito  IxHty  which  arc  involvMl  in  a 
change  of  poailion.  And  if  it  bo  trv«  aa  affirmed  by  tunic  olwrvcr*  that 
both  andilory  nerves'  may  lie  completely  nnd  permanently  Mevvm).  wiihutii 
as/  aflbct  ou  the  coordination  of  moTcmcnla,  it  is  obvioua  that  thu  incufinli' 


TBE  hhais-. 

nation  wl)k'h  follow*  upon  icrtion  of  (be  Mtnicimilitr  canRb  m  dw  f  ■•m 
sjircinl  irrilnttoti  Ml  ii{i  hr  tlio  nporalioii,  Htiil  nut  lo  tite  incr*  abariuv  nf  u; 
normal  aiii|Hillnr  impulses.  On  the  other  hnnd,  if  lhe«ffi>ct«  w  ihoM  nf 
irritution,  it  is  dillicuit  to  nndereltind  hoir  thcj  mi.  us  fl<.-c<anlini;  tn  emiii 
obwrvcre  lh«y  corliiinir  do,  become  p«rmaneni.  It  )iiu>,  bimrrr,  ka 
mmngly  urged  tlmt  io  hicIi  cwm  nf  pcrmmnent  inontirdiniition.  llir  (i(«rai)Di 
hit»  Fct  up  wcondnrr  mischief  in  the  brain,  in  the  cMvhoIlum  for  iMlaan^ 
wiib  uhitrh,  »  we  jiuvo  »eeii  (§  0I!>>,  tlifl  vcMibalar  auditorf  neno  tMbs 
itpcvtiil  connections,  and  ihut  the  permuaeot  eSteta  are  re*]!;  dnt  to  iht  di» 
eaw  f^in;;  on  tiera;  aivl  we  have  reaton.  lis  vre  »hall  w«,  to  ihiiik  thit  iW 
cerebellum  is  concerned  in  the  (;»5i<ti nation  of  movements.  Ii  oannii<,ihrf» 
forv  l>erepirded  Ha««ttle«l  that  (be  mnnl#  iire  tin-  rH>iirce  of  normiil  iin|wlMi, 
or  that  our  coiiscloua  appreciation  nf  the  i>rtMiii>o  of  the  buul  ainl  (•>  »(  Ik 
body  iu  «pace  is  baaed  oa  aiich  impnUw.  But  mieb  a  view  b  nut  diapmtd; 
and  in  any  caae  it  remains  trui^  thai  injury  to  the  rana1>  tlo«a  In  fniw  nj 
or  other,  eitht^r  by  piieraling  n^w  impiilw.-*  or  by  allcriu);  prerxiMintt  uui, 
so  modify  tlie  flow  nf  aHercnt  imiiulMa  into  tbe  machinery  of  co  urdiaMM 
as  to  throw  tlial  machinery  out  «f  gear. 

$  644.  We  have  dwelt  on  the»«  pltcnomcna  of  the  •emicircidar  (auah 
l)ecauM>  they  illunralv  in  a  alrikinj;  manner  ihc  important  part  played  bf 
nH^rent  impnlM-s  in  tho  couritinatinn  i>f  movemouii.  We  taw  rea.*oti  t) 
ibink  (S  ■'>9l>)  that  oven  in  an  nnliuarr  rrllei  mnvemeiit  carriMl  out  by  th* 
tpiiial  ennl  or  by  n  porlinn  of  lliv  curd  atli-rent  in)pulii«)i,  otlM-r  than  ihoM 
nhti'b  cxrtte  the  movement,  arc  al  work,  dvli'miiiiine  fruch  coilSnU nation  at 
in  pnvcnt  In  each  a  cfl»e  tlic  cionlinating  ajfi-n-nt  impulm,^  ar«  rclaiinlf 
Ktiupli-  in  charoclcr  and  rtnrt  chictly,  al  all  event*  in  the  muiwlca  cunKni«<L 
In  an  aiiinml  [low.'ninf;  the  lower  parlsiif  the  bruia,  thtiuirh  di-priv-d  uf  ih» 
eerehral  heniiH|i)ieree,  the  coonliuatin;;  aficreiil  impitlicp.  in  ncoiilimee  «tU 
thu  greater  diversity  aud  complexity  of  the  nuivements  which  the  Biiimal  it 
able  to  execute,  are  far  more  |>olent  and  varied,  Ilct'iiles  aHi^rent  inipubw 
fVom  the  mutiele«,  f'trmiii);  the  basts  of  what  we  have  called  the  muneulu 
seMe,  atlcrent  impidsen  fnim  the  akin,  forming  the  lia'is  of  tbovnge  •tft'Kirli 
in  the  wide  ni4-nniu^  of  that  nun],  niher  afferent  impulsw  of  ol^wure  clla^ 
acter  from  ibo  viiu^-ra  and  varioim  tiHue^.  and  tl>e  peculiar  alTerent  umpullir 
im|Hilw«  (if  nbieh  wt^  have  ji»t  epukcii,  iaijiortanl  s|)ecial  afterent  impulM 
borne  alnng  th«  nerviw  of  tight  and  haarinj;  come  into  play.  Tbe  fr"g,  tfe 
bini,  and  even  the  nmtiininl,  deprived  of  the  wrebral  hemijipberen,  tbinim;''  ■< 
may  *}iow  little  itigtut  i>r  none  at  all  of  having  a  distinct  voliliou,  »,  aa  wt 
have  ur^^l,  indubitably  afre<-lcd  by  vifual  and  auditory  ini|>reisi»M,  aail 
whether  we  admit  or  no  that  nucb' an  aniraul  can  riichtly  be  spoken  of  ai 
being  cimnciuu^  we  eaiiuol  rr*i»l  the  oincbitii'iu  that  affierent  iin|niliin*  ttarted 
in  ill  retina  or  iniernni  ear  priMliieo  in  iti>  central  nervous  ajaieni  chanitca 
Mmiliir  lo  those  which  in  n  c'iin<Wini»  animal  form  llic  basis  of  visual  and 
auiiilory  sensatioDs.  and  we  niit«t  either  call  ihwc  <^hang«d  scnattioos  or  find 
for  Ihcrii  some  new  wonl.  Wh.ilcver  we  call  them,  and  wbethw  eoiiMliNis- 
IMW  i"  ilirtinetly  involved  tn  them  or  no.  Ibey  o1ivi>Hi:>ly  nlav  an  ini)H>rtaat 
pari  iu>  fuetore  of  tbe  cuonlinniion  of  iDOvenieiit«L  Imk-id,  when  w<<  apfiea) 
tA  ihv  experience  of  ourselves  in  |ioeeca»ioR  of  consciouHHMS,  wo  find  tliat 
though  various  sensations  clearly  enter  into  the  eo&rdinatioa  of  our  movr 
m«<nte,  we  carry  out  movcmcnis  thus  coSrdinateil  without  Ih-iu^  distindly 
aware  of  these  co5rdinatin;;  factors.  In  every  movement  which  we  make 
tbe  coordination  of  the  movement  i«  dependent  on  the  impulsnw  or  inllueams 
which  form  tbe  basis  of  the  muscular  sense,  yet  we  are  not  distinctly  coa- 
sciotis  of  these  inipulE«9 ;  it  is  only,  as  we  shall  see,  by  special  analyMs  that 
we  come  to  tbe  codcIunod  that  ne  do  posseas  what  we  shitii  call  ■  mUMuW 


tNTS.     795 


So  agniti.  tiikiiiif  the  iniilter  ffoin  ii  jiotiiculiat  'liB'ereiit  (vkint  of  vi«w, 
if  o«r  ttmvrm-tiis.  iimrktHJIy.  ■»  we  xliall  3««,tboM  of  the  eyel»ill«.  >re 
n<rinliDaln)  hy  viMial  gentiiitonn.  nm)  wlicn  vr«  tJntt  or  wlien  we  tlunra  to 
nitiMc  our  movewmta  iirc  CHinlitiBieil  by  ih«livIpAr*eDBatlnu3of  muihI.  In 
th«M  MM*  dittiiMt  ■eiuMtiana  in  the  ordinary  i^nwofllie  woH  iiitorvene;  if 
wt  ciuinot  M«  or  cnnoot  hear,  ibc  movcmetit  fHila  or  in  imiierfect :  y«t  even 
{n  ihrM  cnw*  wo  »i*  not  dirrctly  cimciou>  of  ilic  tcftntlonii  u  pofirdinniiojt 
fiictoni ;  It  DrMis  nn'fiil  ■luilpf*  to  |)ni70  ihal  the  Mccna  of  the  aM)veinent 
in  rmlly  iJrprmlrtit  nn  ihr  wuinl  or  on  the  *ighl.  TheMHiMl  nthcr  fiictii  oiit^ 
mt  lli«  virw  tbiit  iht-  fHiint  nt  whii-h  the  vnrioii*  nlTerent  ira|Milw>  whioh 
form  lb*  Ixint"  of  the  »eitfUlioii»  nf  n  conwinuit  indiviiltml  rntcr  into  tHc  00<(r- 
dinfttiD^  mwbnni^in  is  or  mnv  lif  w)ni«  wtty  *Ih>t1  of  (hr  »iiigc  nt  itbicli  the 
coni|kl(<I«  oonrereion  iif  tlw  imjHilw  into  n  pcriVcl  iwnwitiou  mki^  jtlnm. 
TliPfvc-nts  which  fonjiiuitpwhiit  wp  inny  call  vi»UHHni[Hilm^,  n»  thiiM;  Ipnvo 
thp  retina  to  »«wp  along  the  optic  nerve,  lire  we  tno«t  nilmil  very  (Hflercnt 
fmm  thiffc  which  in  ihe  npproprisic  jmrls  of  ihc  bniin  ooiMiliitc  whiil  we 
Bmy  ciill  consCToiw  vision  ;  mud  pmhiibty  Itrtncon  iIkt  beginning  nnd  (lt«  end 
there  tre  pragreMive  ohangm.  It  in  probnble.wttMy,  that  these  ritusl  eveuis 
mnyslR^t  lh«  coSrdinating  mechniiisin  at  eoniertageof  iheir  prmrrMs  before 
iher  reach  ihcir  final  nnd  perfect  form.  If  this  be  so  we  mny  fitrlher  con- 
cluae  that  lhoU);h.  when  ihc  whole  ncrvotis  mnchincry  isprcaeut  in  ii^  entirely, 
the  aflerent  impulsef  which  lake  pnrt  in  cooniinalion  miti>1  iaevitablr  at  the 
nine  lime  ^ive  rise  lo  eoDM'ioua  gcntoitionB.  iltey  nii^ht  Mill  eflect  Iheir  coAr- 
■linatinj;  work,  when,  owing.to  thrir  imperftciion  or  lack  of  Ihe  lorminal 
part  of  tbeoervouH  mneliiuery.ibe  impulses  failed  lo  receive  their  Bual  trana- 
formniion.  and  coosciuus  feiisations  were  nhaent.  In  other  word*,  the  coi'>r- 
diniit  int;  influences  (if  »en*ory  or  HlTereiit  impulses  are  not  eMenliolly  dependent 
OD  che  cxixu-nce  of  a  diminct  (viniciou^cit^qi. 

{  645.  We  have  rntncd  this  piiint  piirtly  for  tht^  Mike  of  illiMtmlinir  the 
working  of  ihe  coordination  rnnchincry  in  ihir  nlMcnc^  of  the  eercbrnl  ho'id- 
gi>h(?fe».  hilt  alfn  in  onlcr  to  aid  in  thr  inti-qirftulinn  of  the  ml^Vclive  mtidi- 
tion  which  we  ■|>Fiik  of  w  ^•idrliiirivi  nr  ili/v.iniTui  or  verligo.  We  coni(iarei| 
the  omdilion  of  the  pigeon  after  iin  injury  to  (he  temicircular  cannU  to  that 
of  a  |)er«on  who  n  giddy  or  di/f.y.  nnd,  in<le<-d,  verlign  is  ihe  iubjeclite  vx- 
pnrHion  of  a  dirnrmiigmncnt  nf  ihe  ei>ordination  rnnchincry.  eitpeeiatly  of 
thai  C'wemcd  in  (he  mainlennnor  of  IxKlily  oqiiilihrium.  It  may  oe  brought 
about  in  manr  wiits.  When  a  constani  current  of  adoipiate  slrength  is  stmt 
lliroiich  the  bead  froni  cur  lo  ear,  we  experience  a  pence  of  vertigo;  otir 
ntoTemenla  llivn  ap|M-ar  lo  a  bystander  to  fail  in  coordination,  in  fact  lo 
reeemble  three  of  u  pigeon  whoee  semicircular  t^nals  have  been  injured; 
and.  indeed,  ibe  effects  are  probohlv  produced  in  (be  same  way  in  |I»b  two 
oaaea.  In  whni  a  culled  Meniiyre'a  disense  atlacks  of  vertigo  H*m  to  he  hsmi- 
eiated  with  disease  in  the  ear,  being  atlrilmted  by  ninny  lo  disorder  of  llto 
feiuteirculnr  canals,  and  cases  have  been  recorded  of  ciddineai  as  well  as 
deafnen  reoiiltinK  from  disease  of  the  auditory  nerve.  Visual  teoaattoiis  are 
very  potent  in  producing  I't-rtigo.  Many  perwHia  feel  giddy  when  tbey  look 
at  n  nalerfall ;  and  this  is  a  case  in  which  both  ibe  aenae  of  giddiness  auil 
the  dtumngemeiiit  of  coordination  ia  the  nuult  of  the  action  of  a  pure  aen- 
aailon  and  nothiti^  else.  In  the  well-known  ioteitse  vertigo  whieli  w  enuseil 
by  rapid  rotntiou  of  Ibe  body  vbual  lenaaiiun  ptnya  n  part  nhen  the  rotnlion 
U  carrieil  on  with  the  eyes  open,  but  only  a  |ian  :  for  vertigo  may  be  indure<l, 
though  not  *o  readily,  by  roliilion  with  the  eye*  eompleiely  shut,  hi  the 
lath-r  rate  it  ha*  l>rcn  HUgg4-*li-iI  ihat  the  vertigo  is  cauieil  by  ahuornuil  am- 
pullar inipulfr*,  hut  thi-t«  enn  only  conlrilnite  lo  the  rexull  which  ia  (n  the 
min  rautol  by  direct  disturtionceof  the  brain.     When  the  rotation  i«  c«r- 


rnc  BRAIN. 


ri*^  oat  with  Ihi?  evM  open,  lh«  vfiriii^  wbich  is  felt  when  ili«  raUlisn  i 
\»  pnrUy  rauseH  by  the  vtstinl  ««iiMtii>ns.  nn  accwiDt  of  the  hrhavliir  t 
CjtcImIIb.  coostn^  to  b«  in  hnrmony  with  the  reft  of  ihc  MOKntinnt  nnd  •fitnt 
impuism  which  iiel[t  to  make  up  the  coordination.  The  roUUioo  «eta  up 
jwculiar  oecillnliu);  mnrementa  of  the  cyebiills,  which  continue  for  •obh  timt 
«ftcr  tite  rotation  lias  ceased  ;  owinK  to  thwe  movements  of  th«  eyf^k  llit 
visual  sensations  excited  are  BUoh  as  would  be  excited  if  cicteniJil  abJMtl«m 
rapidly  innvinK^  whereoa  all  tbe  other  senntioaa  ami  impulsw  whidi  in 
alMctinK  the  central  nerToinajruAmirewob  as  an>  excited  brobJMt*  at  rat 
Jn  a  nonual  slate  nf  thinKi*  the  visual  and  the  other  seusalioDS  and  ini|wlMi. 
which  go  ta  make  up  ilie  cui'irdiiiatici;;  niachiuerv,  are  in  at'cnrd  vitii  Mti 
other  in  ^e^«^l>u<^e  to  the  event*  to  the  external  world  which  are  gWim  nm 
to  tliem :  alter  rolatiiMi  (Imj-  are  for  a  time  ia  dida«coriI,  and  tlie  ooordiiiaiiag 
maehinery  i<i  in  <!0ikae(|uaiicc  diMrrnugwI. 

When  w«  inUrrogat*  tmr  own  ofHUciouaneM,  we  Hod  (hat  we  an  nBtdii- 
tincllv  cv)uiicio4i»  iif  ilii«  dioiuicord;  the  vitual  senialions  are  ii>  pnfiotBiit  a 
cnrntrJoufin'M,  that  we  really  think  the  vsternal  world  b  ranidly  whiriiag 
n^uiid,  all  ihnt  we  arc  furlhor  eondou*  «f  i«  thv  foelinj;  of  |{id<lineai  ai>4  nor 
iuabilitv  to  make  our  Wlily  moTmoent  harnioniw  with  onr  viiiial  i 
S.I  that  even  in  i1wciim«  where  lhi>  I'm  of  co5rdlliation  is  hrr>Ui(hl  I 
wnsntioiis  what  wo  raally  appreciate  by  nuauu  of  our  convinuMiaa  1 
dixirnin^mcnt  of  th«  c-Mnlin.iting  machiiiory.  It  b  th^  appncialiun  tJ 
this  disorder  which  consiituUw  the  fMling  or  vertigo;  both  tue  (Ssding 
ghldiiHOB  and  the  diforderod  movements  ar«  tbo  outoonw.  one  «iibj«Mii«  u 
tba  other  objective,  of  tbe  tame  ihiii};.  It  is  not  booauae  w«  ttti  ffjiAii  ihM^ 
wo  KtAgger  and  reel :  mir  movements  nre  wrong  baoauM  the  madiinerv  ii  u 
fanlt.  and  it  u  ibe  faulty  action  of  th«  machinery  which  nUo  makei  lu  M 
giddv. 

We  may  h«r«  perhaps  remark  that  it  is  an  actually  dtsonlei*d  otaditbw 
of  tbe  coordinating  meehanisn)  which  ^ivee  rise  to  the  aAoctiou  of  ooMttMf 
neas  which  we  call  Kiildinee».  nut  n  mere  curiaitin;  of  thi>  mMihanism  >ir  M 
failure  on  its  |)art  (o  make  itself  etreclive.  Cimpleic  hIiiidoeM  limiU  L' 
niue  of  activity  of  tbe  maohinery  hut  leavee  the  remaiiular  intact,  aad  i 
gidataea*  is  felL  Ho  ai;iiin  in  oeruin  diMaaas  of  tbe  nervoos  syaUa 
muscular  iMiAe  ia  enterlered  with  over  c^naidarable  regions  of  the  Uidr,  i 
fa  these  regions  coord i nation  fails  or  is  imperfect,  but  the  central  maeliiMt^ 
b  not  therebv  afliboted,  thoujch  it4  area  of  UMfulneas  u  limited,  and  no  gMJi' 
neas  ta  exp«ri«nced ;  aud  M'>  in  other  inslaneesi. 

S  MS.  Fomid  mortmfnU.  So  far  as  we  have  direU  on  disurden  of  iW 
coonlinaiiiif;  machioery  brougltt  abMit  by  tliu  aeiiun  of  various  aSmai 
iiupulM^.  We  have  now  to  call  attention  to  some  peculiar  pbenonieDa  whiA 
retiutt  from  oitcrative  interference  with  jiarta  of  the  brail),  and  whieh  in  SMW 
inxlanrui  nt  leiwt  may  1>v  taken  to  illuninte  bow  this  complex  naoluSHT 
workH  when  some  of  ili  inner  wliwU  ar«!  broken. 

AH  invcM^tori)  w)i<i  hav»  ptirl'nnni-d  experiments  on  the  hmin  bare  ob 
eerrcd,  as  the  rmtdl  of  injury  to  varioux  |urt8  of  it,  remarkuhle  iniivcnw 
whidi  have  the  apiH^rnncc  of  Wioji  irraistihle,  compulsory,  foroix),    ~" 
Vary  much  in  the  eslCfll  to  which  they  arw  driveloped :  some  are  so  i  ** 
hanlly  to  d<;wrve  the  name,  while  otiK-n  hk  i>lnkin|ily  intenae.     On 
nuat  common  t<>rins  b  that  in  which  tbe  nnioul  roll*  ineeMantly  niund 
lon^tndinsl  axis  of  iia  own  body.    This  b  es{)wially  common  aft«r  tvriiq 
of  otic  of  the  crura  corahri,  or  of  the  middle  ami  inTrrior  pedundaa  nf  I 
oereMlum.  or  after  unilateral  SMtioa  of  the  pon*.  hut  hu  also  basa ' 
nessed  after  injury  to  tlio  b:ilh  and  o-irpam  <|iiadfigeniina.     tJomKimiu  iW 
animal  rotates  towiird  and  loniotinica  away  fntni  tbn  skis  operated  na. 


» 


^ 


lAhrr  fi>rni  b  that  in  whieti  t)io  animal  exectilea  "circuB  mnveiiieats,"  i.  e., 
coniiiiiinllj  inovra  rmiiiil  nnil  ruuml  iu  a  circle  of  lua|(vr  or  iih'>rt«r  ruiiiua, 
•iiinclinMB  toward  hik)  HomclimM  away  from  the  injuiwl  oido.  Tliu  nuiy  lie 
MTU  Bft«r  Mveml  nf  lli«  above-raentluned  operations,  antl  in  one  fiirni  or  an- 
otlirr  ia  Dot  iincminioM  aflt-r  vnriouit  uniliitcrnl  iiijtirim  tu  ibe  bniiii.  Thvre 
it  a  vnrirtv  uf  ihc  circiut  inovcmeiil,  lliv  "cKx'klianil  ranTctneiii,"  himI  ta 
ocnir  frTi)UHiltv  after  InnonMoflbe  piMcrivr  curjinni  iiuaJriguniiiin,  in  wliioh 
tbi' Buinial  oii>v4ts  in  n  nrcle,  wttb  tbe  lungitmlinat  nxin  of  lis  body  oa  a 
ndiuM,  anil  the  end  of  il«  luil  fur  a  mnln!^  And  llii*  form  again  may  carily 
{MM  into  a  simpler  rolling  movement.  In  jet  anollier  fiirro  (he  Animal  roUUM 
ov«r  lli«  trwwvfnw  nxi«  of  itn  ImmIv,  tiinililw  head  ovw  heidit  in  a  >ori««  of 
MMiH'taanllR ;  or  it  may  run  tnnauiDtly  in  a  niniighc  liui-  liackwan]  or  for- 
ward until  it  is  atojipcd  by  aoiM  obMnclo.  The*i.^  lallcr  form»  nf  forced 
wov<^mc»l»  are  somelinM*  aecn  »1\tr  injury-  to  itir  eorpiiK  mrintiiui  i-vrn  whun 
a  v^rr  limited  portion  of  tho  gray  mniK^r  j*  iiHK-led.  And  many  of  thcM 
furc«(i  movcmrnU  niny  rtMilt  from  injurka  which  npfvear  to  be  cuolincd  to 
th«  c«rvl>ral  ciiricx. 

When  tbe  phenomma  are  well  davelopcd,  vvery  cflbrt  of  the  iinimni  bringa 
on  a  movement  of  this  forced  character.  I^ll  lo  iieotf  an<l  at  n.-«l  tii«  ani* 
nial  may  ptment  nitthing  iibnormal,  il«  ()o»Tiin!  and  ulliKidu  may  be  quite 
naluml ;  but  when  il  in  excited  to  mow  or  when  it  attempts  of  ItMlf  to  nwve, 
it  exeeutce  not  a  nataral  movement  hot  a  forced  one.  turning  round  or  roll- 
iug  over  a«  ihe  case  may  be.  In  xevere  cases  tbe  movement  is  conttnuctl 
until  tlie  Bntmnl  is  exhausted ;  nhcn  tbe  esbaustioD  passes  oM'  tbe  iioinial 
niAT  remain  for  some  little  time  tiniet,  tint  fome  stimulus,  iniriaaic  or  ex- 
trinsic, soon  inauijuratcs  a  fresh  outbreak,  to  be  a^in  followed  by  exbauatioD. 

Jn  some  of  lb«  milder  fonns,  that  lor  instance  of  the  circus  movement 
with  a  lon^  radius,  the  curved  character  of  tbe  pro^resxioD  appear*  aimply 
due  lo  tbe  tact  that  in  the  clTort  of  lucuwolinu  vuhtiitual  inipulata  do  not 
gain  oucb  ready  acKxsa  to  one  nde  of  tbe  birtly  a*  tu  the  other,  die  injury 
navibg  eauaecl  aome  obtiacle  or  other.  Heuoe  th«  contractiomi  of  tbe  mu*- 
clca  of  one  aide  (the  left  for  insianoe)  of  the  body  are  niortt  jKinerful  than 
Um  Other,  and  in  conwequcnc*  tbe  bcxly  i*  conlinuiilly  thrunt  tonanl  tbe  other 
(the  right)  fide.  A*  ts  «<'ll  known  we  ouRfulvrf,  wbeu  our  walk  ia  not 
guitled  by  visual  wmuitioii*,  lend  to  dencrilio  a  circle  of  fontt-nbat  wide 
radiut,  iW  (k-vialinn  being  due  lii  a  want  of  bilateral  *ymm«try  in  our  liinba  ; 
and  the  above  circii*  movement  i»  only  an  exnggt'ratiun  of  tbut. 

But  tbe  other  mure  itilense  fomu  of  f'jrecil  movemcutM  arc  morn  compIE- 
caird  ill  their  nature.  No  im-rc  blocking  of  volitional  imi>ultcs  will  explain 
nhy  an  animal  whenever  it  elteniptc  lo  move  rolls  rapidly  over  or  ruihca 
irreaialibly  forward  or  biickwanl.  It  ia  not  poaiibic  with  our  prevent  knuwl- 
fdf^  l4> explain  how  each  particular  kiiKl  of  moveoieni  i»  brought  about: 
and.  iodcvd,  the  (cvernl  kinds  are  probably  brought  about  in  ditlereol  wars, 
for  they  dilfcr  ao  greatly  from  cncb  oibcr  that  we  only  clan  them  together 
because  it  is  diflicult  to  know  wlicro  lo  draw  the  lino  between  them.  Uut 
we  may  regard  the  more  intense  lurme  as  illiisltatiug  the  complex  nature  of 
what  we  have  cvlte^l  the  coordinating  nwchinery,  the  capabilitica  of  which 
are,  so  to  speak,  di«closed  by  its  being  damagol.  •'fucb  groM  injurica  as  an 
involved  in  dividing  cerebral  stcncttirea  or  in  injecting  corrosive  mfastanoe* 
imo  this  or  that  pun  of  the  brain,  must,  of  necenity,  portly  by  blocking'  tbe 
way  to  tbe  impulses  which  in  a  normal  state  of  things  an  oootinually  [m«b- 
Id{;  from  one  i«rl  of  the  brain  to  another,  partly  by  ({eneiating  new  unUMial 
impuWa,  »eriou«ly  nUed  tlK>  due  working  of  llie  general  coordinating  machi- 
uerv.  The  fact  that  an  animal  <--aa,  ai  any  moment,  by  an  etfort  of  its  own 
w)l(,  rotate  vu  its  axi«  or  run  slrnijjht  forwaixl,  shows  that  tbe  nervoiu 


79S 


TRK    BBAIK. 


i-nntintio  bi  mt  iritl)  mm  if  ili  bt-nk  bo  |>luDg«<d  intn  water  or  iitln  ■  hrafl 
loirli'v ;  the  iili|;lil  aiipporl  of  tltc  wat«r  or  of  the  imin  seema  siifllvical  M 
fl««<l}^  it«  mnvcminits.  In  the  mme  itny  it  can,  even  wilhriiji  kiwfatuei, 
cimn  itN  fcnthors  nnd  scrnich  iix  bend,  its  Iwak  and  foot  b«uiK  U  1^ 
u|irnilUin»  guided  by  cimliict  vtilb  its  oKn  body. 

The  nniount  of  disorrlor  thus  induced  dil)i>ra  io  difTeKot  bird*,  uid  tarn 
inov«iiHnt«  nro  toorv  tMeclvd  thnn  othora.  As  a  g«ii«rHl  rule,  it  mar  ha  hU 
that  the  mnrc  oamplcx  nnd  intricate  a  niovenient,  the  fnll^T  and  nuiC 
driicnie  the  onnrdiiinlioo  needed  to  carry  it  out  HiocevHlullv,  the  nun 
iuark«dly  ia  it  disnrdered  by  the  operation:  thuR,  aAer  injury  to  t)te  aaab. 
while  n  pigeon  cannot  tty.  n  fjooac  is  etill  abl«  to  swim. 

Id  mammals  i  rabbits  i  serltunii  of  tlie  canals  aisu  pmduoca  a  Cf-rtjuu  aDinaU 
of  Inas  of  coordination.  bn(  luuoh  leas  than  that  viueaned  in  binU ;  and  ikl 
moTemenis  of  iW  head  are  not  m  niarke<l.  peculiar  oacillnting  RKtvaaMMH  rf 
the  evebatU,  dilfi-rinK;  iu  dir«eiion  and  charaotcr  aooonlin^  lo  tho  ctnl  tf 
nuiafs  operated  upnn,  becomitiK  lii^wever  protulDciit.  In  the  frog  no  (l«rW 
tiuna  of  the  bead  are  Men,  but  tltere  it  ixHneliMDrooJSnliQBtinii  io  tb«BM*> 
inents  of  the  body.     In  fiihea  ho  ell^t  at  all  b  produoM). 

Injury  to  the  bony  canals  aloiw  u  intufficient  ta  prmltiMt  th«  sritiptaai; 
the  tnembrannus  canaU  llieniaelTei  Diu*t  be  diviiki)  or  ttijurvd.  Tm  elMno> 
tcriuio  niovementa  of  tli«  head  may  ho<irov«r  b«  bmuglit  about  tn  a  M 
without  ojWDing  tlie  bony  canal,  by  widdmly  boating  or  ooolinj^  a  caul 
tttpecially  itii  ampullar  t^rminatiiMui,  or  by  the  making  or  breaking  of  a  «a> 
atnnt  eurrcnl  directed  through  the  eniinl. 

There  can  l>c  no  doiilit  that  tbiwA  cltarnotertXic  ntoremeDia  »f  tbe  haul  W 
tlifl  nsull  of  aflitritit  impulMv  •Uirtecl  in  the  nervouii  rndinf^  of  the  auiliwy 
nerve  over  the  nnipuUa  of  the  cnnal,  and  conveyed  to  th«  brain  along  thil 
nerve.  And  Ihnl  injury  to  or  other  stimulation  of  each  of  the  ibni-  iaoiIi 
should  produeu  in  cadi  caw  a  difl^ront  movement  of  (he  bead,  tlie  ilin-i-iiaa 
of  tl»e  moTemant  being  dtflbmt  according  to  the  plane  in  which  iK<- <-:iii«l 
lies,  ehons  that  these  impulsoa  are  of  n  peculiar  nature.  This  ia  furtli'  : 
treted  by  the  following  experiment.  If  ilie  borizonlal  caual  be  m! 
laid  bare,  and  the  merobraDous  canal  opened  to  as  toexpoiw  the  endi'Iunjih, 
b!nwina>  gently  over  tbe  opened  canal  with  •  fine  glass  canula  will  pn«laa 
a  <lefinrte  movement  of  the  bead,  which  is  turned  to  the  one  aide  or  to  lb» 
other,  according  as  the  current  of  air  drives  the  endolyinph  toward  i>r  »nj 
from  the  amputta.  From  this  it  is  inferred  lliat  a  movement  of  the  «tii> 
lymph  over,  or  an  iocrensed  pmsure  of  the  endotyiDph  on,  the  nervou*  rait 
IngM  in  tlic  ampulla  givM  rise  to  aflerenl  impubee  which  in  wmx'  way  lUut- 
mine  the  ia«ue  of  eflvrenl  impulses  leading  Ui  the  movement  of  th*'  liciul.  Et 
E«  further  niggMed  that  since  tbe  planes  of  the  three  canaU  lie  i»  th«  itine 
Bx<s  of  H))aoe,  anv  change  in  the  position  of  the  head  miial  lead  tn  ebans* 
in  tbi^  prtrwure  of  the  eii()o1yni|>li  ou  the  walls  of  the  ampulln  or  to  no**- 
meniK  of  eiidoljrmph  over  those  walls,  and  »o  roust  ^ve  rise  to  impubas  ]m» 
ittg  uii  th»  auditorv  nerve ;  and  that  t>\nct  every  ohanae  of  position  will  aAM 

the  ibrec  canals  <lilfureotly  (whereas  the  changes  of  pre*urv  of  lb i" 

Ivmjih  involvetl  in  a  "wave  of  sound"  will  affile*  all  ihrae  ain|Hillnf<ju.<!it 
tlioeO  impulsM  will  difli-r  aeeordin^c  to  tlie  dirvelion  of  the  cfanngi^  A  itill 
further  extensioo  uf  this  view  supjio^nu  ihni  miMv  in  any  oiio  pxsilJun  nf  til* 
liend  tbe  pressure  of  tliv  cndolymph  will  ilitlbr  in  the  lbnx>  ampulbe,  iwrt 
position  of  the  head,  bi>  ilitiliiiinitfJied  from  i-)iungc  uf  poaition.  is  Bd<<<|iMt«  to 
generate  afferent  impulM-a  <litt«rin|;  in  the  dilTi'rcnt  ]>««itionfi. 

X^  us  now-  for  n  whib^  turn  Buidn  to  oiirM>lvni  and  examine  the  ooOntins- 
lion  of  the  movcmentN  of  our  own  b(Mliw.  When  wi:  ap|>cal  to  our  iian  r-nt- 
sciuiisaesB  we  find  that  our  movumuiits  arv  governed  nod  guided  by  "hsl 


TnE   HACniXEBY   OP  COUBDINATBD    N0VKXEKT3.     793 

a' tatty  mII  ■wnM:<if  equilibrium,  bv  an  H|>prEciiiLioil  «f  tlw  pwilion  of  Mir 
Kxly  nnd  i\»  rvliUions  to  R|mcv.  Whvn  ihio  Mtnsc  of  equilibrium  in  <li*turb«(l 
Mr  wo  nrc  <)iixr,  nnd  we  then  elitg)^-f  nnd  reel,  boin^  no  loiigtT  nblc  lo 
icvirdinitlv  tbo  movcmrtils  of  our  bodiw  or  to  lulnpc  lh«m  to  lb<!  jMHilinn  nf 
tliiriK"  nrimitd  iii^  Wliat  is  tbe  origin  of  ilii*  «i>»p  of  equilibrium  V  By 
bat  mMui<>  are  irc  able  to  np)ireciiit«  the  pneitiOD  of  our  body  t  Tbim'  cnn 
B  no  diMibt  that  this  appreciitlion  is  in  Inrgfl  meMUr«  the  prodncl  of  visual 
nd  laciiUi  nenntiona:  we  reoot^izo  ihc  relntiuns  of  our  body  to  tbr  tbin^ 
Ikkiih)  us  in  great  measure  by  siKbt  nud  touch ;  we  also  lenm  much  by  our 
UM-ulnr  HUM.  But  there  ismmetbini;  bfl^ide0  tbeae.  Neither  sichi  nor 
luch  nor  musculftr  ien»e  can  help  ua  wben.plaoed  perfectJy  flat  and  at  rent 
11  h<>rij:iinia]  rvilatin;;  table,  nilh  the  eyes  «but  anil  not  a  miiBcle  stirring, 
'«■  Rtii'Uipl  U<  delertuine  uheilier  or  no  the  table  and  we  nith  it.  are  being 
vod.  or  to  ascertain  how  much  it  and  we  are  turned  In  the  rif-bf  or  to  th« 
pft,  Vcl  under  such  oireuiii8lano«  we  are  cinaciuu?  of  a  clian}»e  in  our 
loflitioD.  and  eome  obiervers  have  been  even  able  lo  pam  a  tolerable  suooeM- 
al  judgment  as  lo  the  anitle  through  which  lh«j  liave  been  tnored.  There 
BO  be  DO  doubt  that  such  a  jmlxment  is  baaed  upon  the  interpretation  by 
DaaeioaeaeMofalTereDi  impulnoewltich  are  dependent  on  the  position  of  the 
Kiily,  but  which  are  itot  affeKnt  impulaea  belonging  tottenmttont  ortou<;h  or 
iRht,  or  lakint;  part  in  the  muscular  »e»*e.  And  it  in  urned  with  Kreat 
Hausibilily  that  the  uiTervnt  iwpulntvi  in  qiit-Jilion  an;  ibue  which  we  liave 
Di»l  referred  to  a*  itart«d  in  the  Mniiciniulnr  ranuln. 
If  we  admit  the  exinlcnoe  ofsuch  ampullur  impulwi*,  if  we  may  venture  to 
call  them,  and  recn^iniie  lti<-nt  lu  iiinlributing  Inr^ly  not  only  lo  our  direct 
rceptiun  of  the  [Kuilion  of  ihc  Intiil  and  thuii  of  th<!  botiv,  but  a1»o  in  a  more 
direct  way  to  what  we  have  oalliHl  the  scnou  of  equilibrium,  we  should 
(lect  to  find  that  wbou  they  an-  abnormal  ihv  vrnw  of  rfiuililirium  i»  dia- 
rfoed,  anil  that  id  conwquenc"  a  failun-  of  coTirriimilioii  in  our  movi'incuiM 
Ita.  And  tbe  loM  of  coord  i  mil  i»n  which  nc  drvcrilHfl  above  n-i  nsnllin;; 
iiu  injury  to  ihf  Mmicirenlnr  caiinlii  h»:>  acconlingly  been  uttribuied  lo  n 
ticirncy  of  dinordcr  of  normni  ampiilUr  impiitmi'. 
Btll  wo  inurt  here  di»lin|^iii«h  Ijclween  two  th)ng».  It  wcm"  cWr  (hat 
bta  Ibe  membranous  ciinnle  arc  injured  or  othcrwiM'  vtimulatcd  alTcmit 
Dpulam  are  Kcoemted  which, on  the  one  ban<l,  may  produce  [Ntciiliar  moro- 
IMilB  of  tbe  bead, and  on  the  other  hand,  ecem  able  when  the  injury  lit  lar^ 
<  oiiiK!  a  Ion  of  coordination  of  bodily  movcmeuta.  But  it  dom  not  iH)c«a> 
rily  follow  from  thiti  that  in  a  normal  condition  of  ihini^  atrvrenl  )ni)>t)lMs 
re  cniitinually  pa^siu);  up  to  tbe  brain  from  tbe  semicircular  canal",  nnd 
It  tJ)o  loM  of  on6n)ii)ation  which  follows  upon  injury  to  the  canals  is  due 
these  noriDa)  impulses  being  doHcient  or  altered.  It  may  be  that  such 
Drma]  impulsea  do  not  exiai,  ami  that  tbe  loea  of  coordination  is  the  reeult 
f  tbe  central  naehinery  for  ooordinaiion  beiun  interfered  with  by  '(uite  new 
ipulsd  fTcnerate'l  by  the  injury  to  the  canal  with  tbe  coasequeut  lose  of 
laolynipli  acting'  ae  a  stimulus  to  the  eudini^  of  tbe  nerve.  For  the  exf»- 
>nce  quolol  mIiovo,  lhotif(b  it  provcti  that  atferent  impulaw  other  than  tbrM 
'  aitlbt,  touch  and  tbe  muscular  sense  do  reach  the  brain  and  afford  a  baais 
r  M  judgment  aa  to  the  pi^iiion  of  the  body,  doee  not  by  ilaelf  prove  that 
idse  impubn  cone  from  tbe  eemiciroulnr  canals ;  the  arraDKemeut  of  the 
tnnls  is  undoubtedly  sugMstire ;  hut  it  in  quite  |)o»>ihle  that  the  adWrent 
i)mUea  in  queation  may  be  (generated  by  one  or  other  of  various  chanxea, 
laotuofir  and  others,  of  the  tbauee  of  the  body  which  are  involved  in  a 
fbaniri-  of  |M»ilH>n.  And  if  it  be  true  aa  affirmed  by  some  observers  that 
^tb  auiliiory  nervca  mar  \*e  completely  and  [wrmanently  severed.  with<mt 
~  ly  eflect  on  tbe  co6rdiuatiou  of  rooTements,  it  is  obvious  that  tbe  incoSrtli- 


TnB    BRAI!9. 


BRtioti  which  ro11<iw*B  upon  eoctioD  or  iho  semifiniilnr  caimN  n  iIiik  (OMim 
sprrinl  irrilnlinn  set  up  by  th«  nperaUou,  nnil  not  to  tho  mfre  nb»rtioc  of  Itf 
normn!  nmpiillitr  impulse.  Oa  the  other  hand,  if  the  eflecta  nn-  (1i»hi  at 
irritHlinn,  it  is  ditBi^ult  lo  utidereUiKl  how  ihey  can,  ns  arcordio);  In  in-ruil 
oWrv«rB  thev  certniiily  do,  beooms  perniniMDl.  It  bus,  b»wpwf,  tn^a 
Mroni;ly  urjt^d  ihat  iu  such  ciwes  of  p«riiiaii«nt  ioooSnIinaliou.  ih«  u\'<-—<  t- 
hne  set  up  wvoudin-  tnisdilef  in  lli«  bntin,  in  the  cerebelluiu  fur  <<  - 
with  ti'birh,  m  w«  have  aet-a  (§  CItJ),  ih«  veatibular  auditory  nerve  m^m 
Hpet-ial  coiioe<rlii>i»,  aiid  that  th«  pennanoDt  effbcts  are  really  due  to  thi-  ■!» 
mae  Roint;  <>ii  h«r<-;  niid  ne  bav«  rv«Kin,  u  we  shall  sc«,  in  think  iliai  iht 
cerebellum  is  coticvnm)  in  th«  nr)0itlinali«o  of  nunminenii).  It  ckiinM.tlwn- 
fore  heKicnrded  iw iwtl1<-*l  tbiit  tho  caaab  are  thi^  «'>urre  of  nnrmiil  tm|>ul«^ 
or  that  our  contciou*  apprcnstioa  of  the  iwmiion  of  lb«  head  ami  »•>  i'(  iW 
Iwdy  in  fpacc  W  baMd  on  *ii<-h  ipnpulHo*.  But  tiiich  a  view  is  not  dtiipr'vnl; 
and  in  any  oho  it  rmiaiDR  triK-  that  injury  lo  tbr  oauaU  d»«>«  in  vrnf  war 
or  otlwT.  *'ithfr  by  ^ntmting  iww  im[HiW«  or  by  altfirini;  prri'xiaiii 
HO  moiiify  th<'  flow  of  aHorent  impulmi  into  ibe  roachincry  of  co  orWn 
tm  to  throw  that  niovhiiwry  oiil  of  gt*r, 

i  644.  Wo  have  dwell  on  tbow  phennnwia  of  the  aoniiHrcular  ram!- 
b)x-atif«  thry  illustrnio  in  adrikin^  niann<>r  tliv  important  [wrl  pt.-. 

affcmit  impiil««B  in  th«  coordination  of  niov<inK-iit».     W<>  knn   r>u 

think  (S  '^W))  that  ev«n  in  an  ontinary  retk-x  Riov4-nu>nt  carrio'l  out  br  tlo 
»{i«Dal  cord  or  by  a  portion  of  the  nirti  alK'n-nt  iinpiitMM.  other  than  ihiw 
whit'h  «xcile  Ibe  ntovemenl,  aro  at  work,  itvtrnuining  Mich  coCnlination  ai 
it  pnwnt.     In  wch  a  nse  tho  eo&ntinaling  aA«r<-nl  inipuhxM  an  n'  ' 
ilmple  in  fihaneter  and  start  chiefly,  at  all  eventa  in  the  iDitaclca  wi 
Tn  an  animal  poase^iuK  the  lower  parts  of  the  brain.  thoui:h  dt-privnl  >'i  tr>F 
cerebral  bemispherf^.  the  co^nlinntint;  afli^rent  imputsee.  in  ncc»nlaii(«  uii^ 
lh«  (jrenter  diversilv  ntiil  <.t>niplexity  of  the  movemenls  nliifh  the  an' 
ab'e  In  execute,  an*  far  mure  |>otenl  and  varied.     He*  i- 1  v*  n  tie  rent  '.n 

from  the  niii«r]c«.  forniin!;  the  basis  of  what  we  havi^  cnlled   the  it 

sense,  niri-rriit  ini]<utM-B>  from  the  skin,  forniinK  the  l^ai't*  of  the  v-nf  ni  i<  i' 
in  the  wMk  rm-aiiiiij(  of  that  word,  other  aflerent  imptitsM  of    i 
acter  fmni  the  vi«*ra  and  various  tisftues,  and  the  peculiar  aU'er-  n 
impul»e«  of  nhieh  wo  liave  just  s|ioketi.  important  specitd  afTeivnt  imi'iii" 
home  alonji  the  norv««  of  xjght  and  Iwarinj^  ooino  into  piny.     The  ft'L-.  !'>• 
hjnl,  an<l  oven  the  mammal,  depHveil  of  the  cerebral  liomispberea.  tli 
may  show  little  *igm  or  iMwe  at  all  of  bavin);  a  distiuut  voUtion,  t<.  ^ 
have  tir):eil,  imhihitubly  afloe(«>l  hy  visua]  and  auditory  imprawinnt,  Mri 
whethi^r  we  admit  or  no  that  Mich  an  animal  can   rightly  be  ^■"■^.—    >'■' 
Iwint;  eoimciouK  we  cannot  rvillM  tho  conohision  that  afliirent  imj' 
in  it*  retina  or  internal  ear  prodiieo  in  ita  central  nerroua  ayntem  mu':--- 
similar  lo  thcwe  which  in  a  ccKiieiouit  animal  form  the  baaiii  of  vfamlw 
auiiilory  w^niiatiimf.  and  ne  murt  either  rail  tbeae  obaneu  aenaMloU  M  lal 
for  tlii-in  »»niv  new  won).     WhaCevoj-  we  call  them,  anil  whaiher  cuaudM*- 
nMK  i*  diiAinelly  involved  in  them  or  no,  ihey  obviounly  play  an  imp<ftwl 
part  iu>  factiioi  of  the  ci»jnlinulion  of  movvnienlH.     Intlvi-<1,  when  Wo  ■tpT'*' 
lo  the  eipvrieoou  i>f  ourMlvi-M  in  pooKwiion  of  o(Mi«riou»n«M(,  wa  Dml  thii 
though  varioiH  seiuntions  clearly  enter  into  the  eodrdinatioo  of  nur  nuin 
mcnlM,  we  carry  out  raovomenla  thu»  cnordinaitKl  wiilmut   l^-injj  dWintttf 
aware  of  these  ctKinlinating  factors.     In  everj-  nioverm-nt  wliicli  w*  m»l« 
tho  co6r*linntion  of  the  movomont  is  de|>enilcnt  iin  the  impulst-s  or  inflortW 
which  form  the  baa'^fi  of  tlw  mtiaoular  sense,  yet  we  are  not  disum-llv  e^* 
sciwi*  of  these  impulse:*:  it  is  only,  as  weahall  m'«,  by  speetal  aniitrui  tlul 
w«  come  to  the  eoncbiaiou  that  we  do  puescn  wliat  wo  snnll  imll  a  mUMmlv 


I 


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I 


BSBN.  60  xgain.  lakiiiK  iW  nintlcr  fmm  n  ttointtwliitt  fllflV^rGiit  point  of  view, 
manir  of  utir  rooremfiuti,  marknlly,  u  we  fthnll  mo,  ihooe  of  lh«  eyelwIU,  are 
oMinliiialcd  hy  vlMial  aetmili'ms.  and  vbo)  we  xin^  nr  when  we  dance  to 
muaieour  movt^nH'TiU  arPivH^rtliimtrd  f>T(li<!  hi.-l|iorM>iiMition!i  nraotind.  In 
llieee  cawa  dinliacl  .■x-iiniKioiin  in  [ho  urdiimn-  m-im^  of  thi?  wonl  intervene ;  if 
we  nuinot  hm  ur  );niiiiot  lit-nr,  ihr  mcivinni-nl  luilii  nr  i»  ini|>i-rf(-(rl :  ¥■-'(  fven 
in  thrw  cnsn  we  iiro  i>»t  directly  (-oiiin'ioiiii  uf  ihr  *cnMilii>:u>  iin  ni^inliimiinii 
fartnni ;  it  nro<)K  ciircrul  iiriiilv<i:>  l'>  pmvc  (hut  lh<-  *nc-(T!B<  «f  tli«^  mi>vi>m('Rt 
ia  ti-tdly  drgieiultiit  oti  the  Mnitiil  "r  <>n  iho  *i[!ht.    Thr^r  and  other  fnci*  hik- 

!;PM  (he  vH-o'  (liiit  ill-'  |H>inl  lU  whk'h  tii<^  vnrioiiit  nfffrrfnt  impiilw^  which 
firm  lUc  liiwif  uflhv  ffttfatu^nnof »  ci>ii«pioui!  itidivi<luiil  witcrinWi  Ihe  co5r- 
(iiftating  mct^banisDi  is  or  mar  be  »»me  way  Khort  of  the  stage  at  which  (he 
cnniplric  cnnversion  of  the  impuliw  into  a  p(^rfcct  sctiHition  taken  place. 
Thr  i-vrols  which  conflilute  what  we  may  call  vi»iial  iiiipiilees.M  theae  teatre 
the  n-liiia  to  sweep  along  the  oi>lic  nerve,  are  we  mii»t  admit  very  diRereat 
Ituri  iIkwc  which  in  the  appropriate  parts  of  the  brain  conotiliile  what  we 
tnay  call  conscious  vision  ;  and  nrubablv  between  the  JM-cinninf;  and  ibe  curl 
there  are  pmgrcasive  changes.  It  is  probable,  we  say,  that  iheae  visual  eveiile 
niay  alTcri  ibe  niordinaling  niechnnisin  at  some  slni^  of  their  prodTesa  before 
they  reach  their  linal  aiiit  perfect  form.  If  this  lie  so  we  may  further  con- 
clude that  though,  when  ihe  whole  nervous  machinery  ia present  in  its  entirety, 
the  nifercut  impuism  which  take  part  in  ciWirdioation  must  inevitably  at  tbe 
aanie  lime  give  rise  to  conscious  sensations,  iliey  migbt  alill  effect  their  eirfir- 
diiinting  work,  when,  owing. to  their  im|*ifrelion  or  laok  of  the  terminal 
fiarl  of  t  lie  nervous  oiacbinery,  tlie  im|>ii)^a  failed  to  receive  their  final  trnns- 
forinntioii.  ami  vonseioils  senaations  wi^re  aWnt.  In  other  wonl.*,  thi>  <iH'ir- 
dinat ing  influences  of  arniKiry  or  afferent  impit Ilea  ate  not  ai«wnitnllyde|>en<lent 
»D  the  ex'otenee  of  a  dialinct  coniti-iou^ueas. 

$  64S.  We  have  raised  ibia  jioint  partly  for  iht^  Mike  of  jlluatmtinir  the 
wnrkin^  of  (he  coa'nliiiation  innt-hinery  in  thi-  almcnce  of  the  cerebral  b(nni> 
ai>here»,  but  ala»  In  onler  to  aid  in  the  inlerjiretation  of  the  sutiieclive  eondl- 
tii>n  whieh  we  spenk  «f  a*  ^iddin<«D>  or  di/7.init«>  or  vertigo.  We  ci>m]Mre'i 
the  eondition  of  the  pigi^m  after  nii  injury  (o  the  M-micircuIar  canaU  to  that 
of  a  iH'nwn  who  in  gidily  or  dixty.  and,  indeed,  vertipi  is  ihe  subjecliro  ex- 
irecsiim  uf  a  di:>»rriing<'rnent  of  the  coiirdinalion  machinery,  especially  of 
eoiicernisl  in  the  niarnlcnance  of  bivlily  <xiiiilihrium.  It  may  be  hriught 
„jl  in  manv  wayn.  When  a  constant  current  »f  ade<|uatv  strength  is  aeot 
trough  tbo  hcail  fr-n.  .  n  .  ■  ;ir  u,  exjicriencc  a  *en»e  of  wriigo;  our 
BtovemeDta  then  api"  <  .n  :  r  to  rail  in  oiirdination.  in  fact  to 

rei^mlile  llioao  of  a  pigeoti  ullo^«  xmicircular  canals  have  been  injured; 
and,  ii)de«il,  lh«  eAciia  arc  prohnhlv  proditi'cd  in  the  same  way  in  the  two 
eiiaea.  In  what  is  callfl  Meniere's  disease  attacks  of  vertigo  seem  to  be  asso- 
dalcd  wiib  diM-ase  in  th«  car,  l>cing  atirihulcd  by  many  to  disorder  of  the 
eeininrcuhtr  canals,  and  c.-ims  have  been  recorded  of  eiddineaa  ea  welt  aa 
dcafiiem  resulting  from  disease  of  the  auditory  nerve.  Visual  senaations  are 
very  potent  in  pnxliicing  vertigo.  >Iany  persons  feel  giddy  wlien  they  look 
ftt  R  waterfall :  and  ibis  is  a  ciise  in  which  both  tbe  sense  of  giddiness  ai»d 
the  diaarrangement  of  cixirdinution  is  the  rMult  of  the  action  of  n  pure  aen- 
Mlioii  and  nothing  else.  In  the  well-known  intense  vertigo  which  ie  <?aused 
bj  rapid  rotation  of  the  body  visual  sensation  plays  a  part  when  the  mlutioa 
b  rarried  on  w  ilb  Ihe  eyea  open,  but  only  a  part ;  for  vertigo  may  be  in<luce>1. 
tliouKh  not  to  readily,  by  rotation  with  the  e>'es  eomplelely  shut,  tn  ibe 
latter  ease  it  lias  been  suggested  that  the  vertigo  is  mused  by  abnormal  am- 
ptillar  impulse*,  but  these  ran  only  contribute  to  the  result  which  is  in  tbe 
niaiu  cauiwil  bv  direct  disturbance  of  tli«  brain.     When  the  rolaliuu  i*  car- 


jj 


802 


THE   BRAI.V. 


Bi<lv«  into  the  nuclear  Injer :  or.  »ut  in  anollwr  wsy,  ui«duiUu-<I  film* 
ing  out  of  the  uudear  layer  at  all  puinU  converse  tii  funn  ilie  ccGttol  ohlK 
iBRlter.  Some  of  these  nbres,  ss  we  have  seen,  beeiii  ur  end  iti  ihc  relUrf 
Purkinjj.  None  at  them  appear  to  join  the  cellti  •>(  tlie  uucliMr  layrr,  inJ 
ve  linve  no  evHleDce  that  any  of  them  end  or  bi^^to  in  any  way  in  tlin  nadai 
layer.  A  certain  number,  Iiowe\'er,  mav  be  setui  to  paw  tlm>ugh  the  naciw 
layer  sni)  Wtoet^n  the  cells  of  Putkinj/- into  the  molecular  layer,  wlwn  Initee 
their  medulla  they  divide  and  apparently  iwintribute  In  tlw  numnoM  Unik 
of  tlie  molecular  layer.  The  pTWUinjXiun,  therefon,  b  that  all  iJie  Ohmrf 
the  while  matter  bi^n  or  end  atlier  in  tlie  cells  of  Purkiujfi  or  tlM  Ibribgf 
the  molecular  layer. 

The  uipcrtic'ial  gray  matter  of  the  cerebellum  then  rcMmUn  the  gny 
nuHtTr  iif  lli<!  tpiiial  cord  in  to  fnr  as  it  oonniKl*  of  hmncbiDg  nemnlU 
ncrvv  lihrwi,  and  nerve  (ibriU  imk-ddcd  in  neuroglia;  but  the  di»f»«Ji"i 
BDd  f<.«turc«  of  the  ncvcral  furlorH  urt-  p««uliar.  We  may  take-,  jt-riiiijn,  m 
the  key  of  the  slnivturc  the  fihril*  »t  the  molecular  layer ;  thii>  layer  i*  nU 
lively  very  thick,  about  4(Kl  f.  murh  thicker  than  the  nuclear  wlii''h.  bi*- 
ever,  vnric»  in  ihioknca.  Wing  gewrnlly  thickest  at  iho  top  of  tlie  UU; 
hence  the  number  of  libriU  in  it  may  be  spoken  of  ns  enoratuUB.  T^n* 
fibrils  •eem  certainly  to  bo  conooded  on  the  one  hand  with  the  call*  ■•(  it'- 
Duclear  layer  and  on  the  otber  hand  with  the  scnitercd  small  cells  u(  timi 
own  layer;  but  we  have  no  eridenco  that  cIkm  two  sets  of  fibrils  an cna- 
tinut>u«  with  each  other :  on  the  contrary,  it  aeem<  more  probable  that  iW 
two  eels  of  cells  repnseut  two  independent  syelems.  We  can  hardW  dmbl 
that  these  fibrils  arc  in  functional  oounediou  with  the  mednllated  ^bra'' 
the  central  while  matter;  but  we  have  no  clear  evidence  that  tlio  fyiUiD 
of  Mattered  cells  is  continuous  either  with  the  cells  uf  Turkinjf.  and  so  aiik 
lh«  medullated  fibres  beloufpng  to  those  cells,  or  with  the  iiiMlullaled  6bni 
which  end  iodependenUy  in  the  molecular  layer:  and  we  have  no  evidna 
at  all  that  the  system  of  the  c«lls  of  the  nucktar  layer  is  nKinoetcJ  wA 
either.  We  can  hardly  think  otherwise  than  that  Itie  nulecdlsr  efanga 
which  sweep  to  and  fro  along  the  tangle  of  these  fibrils  (whose  nntiithah 

frobably  gorerned  and  hence  whose  functional  svlivitv  i»  probably  renUtsI 
rlhe  nuelear  and  scattered  cells  respectively)  are  intlut-uvud  by  or  an|;tatfi 
toe  nervous  imjMibea  paning  along  the  medullauxl  fibnw  of  the  nhiir  malK: 
and  hence  we  must  conclude  that  either  a  ounlinuily  exintii  which  has  m  J* 
esra|)ed  detection  or,  what  is  quite  iMsible  if  nut  probable,  that  one  SM 
can  act  u|iod  another  hy  nimple  contact  or  even  at  a  distmnc«.  Paitbtf. 
while  the  cell  of  Purkinjf-,  niili  its  large  celMiody  and  nucleus,  its  (MBi|ridi' 
ous  Hxi«-cylinder  pr<ictM  and  its  other  branched  proc»M>«  prvaenls  wmkJ 
analogies  with  a  motor  cell,  such  us  ihcate  of  the  aiilcrior  hum  of  tli«  ijaMl 
cord,  and  ra>M«  tbo  pmumntton  that  the  im]>uttN»  which  move  aloog  i> 
axis-cylinder  proctM,  proem  outward  from  ihc  rrll  w  motor  or  at  leota 
eHeiviit  impulses,  welmro  no  dirrvt  proof  that  thi«  is  Ko,  And  thnui^itil 
templing  to  suppoM  that  lh«  other  mmlullai<Hl  fibres,  which  like  the  bbm 
of  a  posterior  not  are  lust  in  ihe  grmy  matler,  nilhoul  tW  iolerveutlon  «f  > 
coDspicuouB  cell,  carry  atlcrcnt  impiilani.  we  have  n»  yet  do  proof  nf  |1m> 
All  we  can  say  is  that  tlie  gray  mailer  is  ciiiiiircled  in  two  dilferent  wsf) 
with  at  least  two  sets  of  6br««,  which  probably,  thcrvfore,  have  diStnU 
functiuDB. 

We  may  here  add  (he  remark  ibat  tlie  large  body  of  the  cell  of  Purkisj' 
lies,  a*  inileed  do  tlio  other  nervous  eleiMDts,  in  an  appropriate  span  « 
the  bed  of  neuroglia.  Between  the  surfaoe  of  iIk  cell  ao<l  tbe  wall  of  phi' 
roglia  is  a  apace,  generally  eo  narrow  as  to  be  potential  rather  than  aciult 
bill  which  may  sunictimes  be  considerable.     >\  hetber  small  nr  large  it  r"- 


SOMK   HISTOLOQICAI.   FEATCKKS  OF  THE    DRAIN.       803 


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Itiiw  lymfili,  anil  tbe  cnvUy  in  whicih  tbc  oell  IJet  ii  ui  oonneetion  nkh  lite 
lympluUHii  of  tbc  bruiu.  Ktich  (till  then  Vit*  in  a  lymph  xpave ;  but  ve 
tncroly  mention  tiii!  pMrt  now  ;  nc  ihiill  havi>  i»  riMurii  In  tbv  niHtt«r  wh«n 
«•  e(Hn«  to  iliuil  witli  ibc  tymphalio  ukI  vuculsr  uTmngemenU  of  Uie  i>nuu 
uid  qdnul  ounl. 

TA«  Cerehni  CorUix. 

^  6ft0.  While  the  euperfiml  gray  matter  of  the  cerebelhim  ioa  not  differ 
ttrikin^ly  m  to  its  hiatu logical  f<paUiK«  in  diflerent  re(;ioi)s,  very  considerable 
ditfert^ncea  are  obserTe^l  in  diller^ni  ivgiooa  of  tbo  nrebral  cort«S.  A  )ten- 
eral  |>laD  of  structure  may  perhajw  be  reco^i^ed,  but  tts  ne  paas  from  one 
|i«ri  of  the  cerebra!  surface  to  another  *ie  find  otodilicatioDS  continually 
lakin)^  place.  We  uiuat  content  ourselvea  here  wilh  attenipUni;  a  iJeacrtirtiou 
uftlu!  f:ei>erHl  plan  ((illoiDeil  by  an  iitdicatiuu  oflbe  more  striking  cbantcUr- 
utiai  of  certain  rei^iunii. 

Hie  eortical  gray  matter,  having  fui  average  Uiickneaa  of  about  3  min.,  1>ut 
vmrying  coundtradly  in  diflerent  regiuns  ttom  1.8  mm.  in  Mime  parin  of  the 
occlmtal  lo)>«  to  -1.2  mm.  at  the  dnmal  aiimmit  of  the  (irecentral  convolution. 
w,  like  other  ^rmy  matter,  comiMmed  of  m-rve-cellA,  and  of  nerve  fibn.'n  and 
fibrib  lupiKiried  by  nvuro^lia.  The  nerve-cclU,  at  l«iutt  the  uonxpicuoiig  and 
Muily  raooKniit^l  norve-s.'eltii.  an-  Hcatlfrcnl,  and  appear,  in  nectionii,  to  l>v 
inibewlcd  in,  and  »e(<oraleiI  fnitn  eat'h  other  by  u  not  inc(inKi<Ifrabli'  but 
variable  c|Uan(ily  of  itnnittwhat  {ii'Ciiliar  ground  milmtanci-,  not  unliki.'  that 
which  form*  w  InrK*  a  i>«rt  nf  tfi*  mcilf'ulur  layer  uf  the  iNTi.7l>clliim.  I'nrl 
of  tlib  i^und  nuhMtance,  irbieh  nnjiarcntly  i«  not  cvmtiiuit  tn  any  piirtifiilnr 
layer,  but  vlrvtchon  Ihrciiighniit  tlie  thicknt.'wi  of  ihfi  (^irt^'X  i«  iindiiiilitcdly 
omrtigliBl  in  nature,  hut  jmrt,  und  priibnblr  the  grpjiter  |utrl,  is  nervous  in 
Dalurc;  it  iw  largely  com|t<iM-d  nf  fine  tibrifi!  tr«V(!r»ing  it  in  various  dirtc- 
tioHH,  tlie  irangvvrw  mvii^nin  of  thi^-  lihriU  giving  it  n  characteristic  doited 
or  "molectilar"  appvaranci" ;  nud  ih<*  ninjnriiy  of  ihwe  fine  tibrilaara  prob- 
ably the  TOiilinuatiiin*  of  branthing  ncrvr-cvlls  or  dividing  nerve  fibres,  the 
remain<ler  Ix'ing  neuroglia)  Hhrils.  Tn  this  r««i)cct  it  memblits  llic  molec- 
ular layer  of  tlie  orrehelluni,  hut  it  !»,  to  a  mtich  greater  vxtent  than  is  that 
layer,  tnvervcd  by  niediitlaled  nerve  lihro>,  especially  by  fine  medulUted 
fibres  like  thoee  wen  in  th«  gray  rantter  of  the  spinal  cord.  §  564. 

The  iKrve-«etla  imbcKldcd  in  this  ground  siibdance  is  more  or  leas  distinot 
layere  an?  of  various  kinds.  The  raoM  conspicuous,  abandant.  and  character- 
istic  nerve-cells  found  in  tlifl  cortex  of  all  redona  of  the  cerebellum,  are  tboae 
which  from  their  shape  are  called  pijritmiiUu  etUs.  These  vary  very  much  in 
utJi  and  have  been  dMin^uislied  as  "small  pyramidal  "  cells  averagiux  12  ^ 
in  length  by  8  ^  in  breaitth,  and  "  large  pyramidal "  celU,  nmfllimee  calleil 
"  iranglionio  cells,"  of  which  the  mcliiim  size  is  about  40  /■  iu  lenittb  by  20  u 
in  br«dlli,  Some  of  the  tatter,  occurring  iu  s|)ecial  regions  are  of  rery  ]arg« 
liie.  120  ;>  by  50  A  and  have  been  calleil  ""  jjianl  cells.' 

The  features  of  a  "  targe  pyramidal  "  cell  are  very  characteristic.  Suoh  a 
edl  nitpears  in  a  well  prepared  vertical  section  <>f  the  cortex  sa  an  elongated 
itoaceles  triangle  placed  vertii-uMy.  with  the  \imv.  lookiu^  t'lward  the  under- 
lying white  subdtance  and  the  taperiug  a|tex  jioiniiug  t>i  the  •iiirluc«.  The 
oell  HubfUnce  u  finely  grauulnteil  or  titirilluled.  tli«  fihrilliL-  aweeiiiuji  round 
in  vnriooa  directions ;  il  not  uafrcuuvnllj'  cuntnins  pignu-ut.  In  the  nii<hit  of 
lhi>  cell  lubatance  ratber  near  the  base  lit-n  a  largi-,  ciciir.  cDiispicuous  round 
ar  oviti  nucleolatiHi  nucleus.  At  tlic  haHc  tbv  <vll  »uh«t«iK-e  ih  pmlongcd 
illlw  a  nURib«r  of  proceMuai.  One  of  thiiK',  generally  Hinrliitg  from  alwut  the 
midtlio  of  the  ba«e,  runs  for  Morae  diataiice  without  dividing,  and  soon  acquir- 


B04 


THE   BBAIir. 


ipea  ni«diilla  may  be  noognieed  u  an  axia-eylinder  proooe;  ihelbrv 
which  it  ijivM  arigin  sweeps  with  a  noiv  or  l»8  curved  couree  iiit»tb«B 
jnvenl  nhile  matter.     Iii  some  instances  llie  Bxis-cylinJ^r  prooav,  kj 
T-division  like  tliat  seen  in  a  f^nt;''^''  of^  *  poetertor  root  (S  91),  gliti 
to  two  libT«8,  one  of  which  mav  take  a  horixonlal  direction ;  in  lotiie  Rc._ 
of  tite  cortex,  the  occipital  I'or  instance,  tlie  axia-cirltn<ier  proems  a  tuA  b 
^ve  rise  hv  division  to  sevemi  tibrea.    llie  other  pmoesses  JVom  the  but. 
especiallv  tfiose  fhiin  tbe  aogla  nf  the  triangle,  rapidljr  branch  inio  fin 
fibril»  u')ii<!h  are  soon  loat  to  view  in  tbe  jprotiiKl  suMtanee.    Tb«  aiiei<f 
the  Iriungle  is  also  prolemgetl  10(0  a  pn>cew,  wbirh,  jc'vin^  ofl*  fine  lat«nl 
braiiclKs,  niHk««,  as  it  were,  i>trait(l>t  for  the  s^irfnce.  but  ultimately  bnac^ 
inj;  into  niii-  librils  la  loat  to  view  at  some  dislnnee  fn>rii  tbe  tiody  of  tbec«ll. 
Tbc  cell  Vu-r.  in  n  cavltr  of  the  ennind  ^tilutance,  which  it  apMan  nonMUr 
to  fill,  but  from  ibc  wallj*  of  wbicb  it  Homeiinics  abrluks.  di'velopinr  hHntn 
itself  and  (be  wall  nfihe  cavitr  as[i«cc  which  may  ooDUin  not  only  ixnfh. 
hut  oct-nsiimidly  WuoocytCH.     (n  preftarod  tpcciaMnH  the  rMractioD  «illiin  ai 
cavity  of  ibo  artiricially  shrunken  cell  mav  tie  oft«a  obacrred. 

The  "small  pynkniidal"  cells  have  inucfi  the  Mint  Mtum:  that  i«inMf, 
IIk  cells  are  charactfriscd  by  ihvir  prrnmiilal  fum.  though  this  is  nsianiJ/1 
not  w  distincl,  by  ilieir  verlioal  |KMiino,  awl  by  the  poasvMton  of  bnartiii^ 

Erootcwe  which  are  bwt  in  the  moUi'idar  ground  subvlnDtx' ;  thcprfMiK*. 
Dwerer,  of  a  niidbnsal  axiscyliudtr  process  has  not  been  clt«rtj  iIvuh- 
•I  rated. 

Otber  nerve-cells  are  more  like  tbc  ordinary  nerrtscells  of  the  ipiMl  mnl 
and  of  tbe  internal  cervbnil  gray  matter ;  they  are  branched  cells,  of  Imft* 
lar,  not  of  pyramidal,  form,  and  for  the  niuet  part  small,  18<>  by  10^  I'M' 
may  be  eliarsoterixed  by  Ibe  relative  large  siic  (7  »i)  of  tbe  nucleus,  uddl 
not  poaacss  au  axidc-ylinder  process ;  ai  least,  such  a  prooan  has  not  yet ' 
detnoDslralei).    They  are  freijuently  spoken  of  as  "anpilar"  cells. 

Another  kind  of  cell,  tbe  "  liiulbrm  cell."  which  is  found  in  all  repMSol 
the  cortex,  baa  a  characteristic  spindle-sbape.  the  cell  subetanco  hetoit  pn* 
longed  at  the  opnosite  poles  into  taperin);,  ultimately  hrandwd  pmesn 
The  long  axia  of  tlie  cell  is  generally  placed  borixontally,  following  tbe  vu- 
vatiire  of  the  cortex,  and  being  Llius  at  the  sJd€*  of  the  sulci  venial  to  Um 
surface  of  the  brain ;  it  is,  however,  at  times  inclined  at  various  angti 

Siill  unoth«T  kind  of  cell,  the  "  granule  cell,"  or  "  nuelear  cell."  b  ana 
which  ihe  nucleus  n  surrounded  by  a  relalively  small  iiuantity  nf  cell 
Ktunce,  £1  ^  by  7  /i,  more  or  Imt  sphcn<ul  in  form  in  onlinary  preparatii 
but  probably  brenking  up  into  dclirate  branched  procwMw.     Cells  nf  thW 
kind  nrespamlyscatlvn-d  throughout  the  (xirtax  genomlly.but  in  [larticulM 
n-gii(ii» — e.  </.,  the  occipital — are  crowded  togatfaer  into  a   layer,  which  in 
many  rmficcts  ra^:mMi!)i  ihe  nudcstr  layer  of  the  oervbetlum,  and  has  h« 
cnlli'd  the  "granular"  or  "nurlcar"  layer. 

Lantlv,  itimughout  the  cunex  are  found,  Ixsidm  indubitable  aerve-cdk 
and  inifuliilalilc  Rfiirogliid  eel  In,  numerous  Nmatl,  ennicwhal  irregular  cslh. 
ccnwniiiig  which  it  may  be  debated  whether  thej  are  rcsilly  iiervmu  or 
Mmply  iii!ur<>Kb"l  )'■  nature.  Honover,  in  using  the  namea  given  above  fot 
rite  vuriou:!  kintU  of  Dorva-calli,  it  must  be  remembered  that  many  tratui- 
tionnl  fiirm.i  an-  ohaerved ;  eells.  for  instance,  may  be  scon  interiuediulai^J 
form  Wlnt'cn  pynimidnl  <.<clls  and  "  fiisifonn  "  or  "  angular  "  cella.  ^H 

The  iurdu]lai<-<l  nerve  lihrra  which  take  part  in  tbc  cortex  may  be  enP^ 
sidered  provtsinnally  ns  forming  two  categoriee.     In  tbe  first  place,  flbns 
sweep  up  verlieally  into   iho   cortex  from   the  subjacent  "  centml    while    1 
niatt«r,"  taking  at  first  11  curved  conrse  as  they  enter  into  the  gray  matter, 
and  iheu  np|M'4iniig  to  run  straight  toward  the  surface.     Tlieae  ore  orrai^td 


m 


soys   HISTOLOGICAL   rBATCRSS   OF   THK    BBAlX. 


in  tha  dMpcr  levels  in  hiindlf*.  leuvine  verticnl  oolumnH  at  Iho  grnr  mauer 
b«lwrcn  tnoni:  but  at  more  siiperficiiiltevt^ia  ibe  biinHlt«BpK9id  omniid  Kre 
cnuluallr  lost  to  view.  Beeidee  tti<«e  diMiocrt  vert4cal  litirra  nod  bundlen  of 
Gbm,  of  the  (l^iiIla^v  modullAted  kiiii),  which  we  have  resMti  to  think  are 
the  vimIm  (or  Ix^nnings)  ou  the  onp  hand  of  Kbra  of  ihe  pedal  and  tegDiental 
(yttcnu^  and  on  the  other  hand  of  libree  of  tJie  corpus  (.'allnatiui,  or  tlie  other. 
wmmWtirnl  fibres  spoken  of  as  "  afaociaiioa  "  6br«a  ',i.  CHrij,  an  esceedinijly 
Inrge  mimber  of  fibres  of  the  peculiar  fine  raedullftted  kind  run  in  rarioua 
directions,  forming  a  <ten»e  network  in  the  jrround  subilanec  of  the  (tray 
mnlh^'r  hetw<«u  the  eeita.  We  may  add  thai  this  system  of  fine  uiedullatM 
librfc  is  of  late  growth,  and  la  not  fully  ileveloped  iu  man  until  two  or  three 
ycare  alter  hirlb.  Many  of  the  niedtillateil  llhree,  coaree  as  well  as  liue,  take 
a  horiioDtal  direction  parallel  to  ih«  surfiii«,  aud  in  certain  regions  an 
specially  <l6vek^>ed  iii(<>  a  lajrer  or  into  two  layera  so  oa  to  form  a  horizontal 
streak  or  Mreaka. 

The  raacular  |>ta  mater  umwla  cimidv,  u  ire  hav«  saiil,  the  whole  Kurfaoe 
of  the  cortex,  dipping  down  into  Ihetuloi;  and  from  \l,  a*  in  the  case  of  the 
spinal  curd,  proecMM  oarryinj;  h!nudve«eU  un>l  Ixnriuk'  lymph  ><[>ui:ei  pa-in 
inwant  to  Hipply  tho  fcmy  inaCtor  with  bloiul.  Ilia  wliilc,  aa  wi:  shall  w-u 
later  on,  the  supply  of  hlooilvea«ela  to  the  gray  nintti.T  i*  roDsiderablo,  tlio 
truljr  euuneotive-twuc  vlnmeiit*  of  tho  iiia  nialer  pron-xam  an-  fmn  method 
into  neumg'lit.  Imnudiatclv  hi-ni.'«tli  tlie  nia  miitrr  furmin^  tliv  iiniumluito 
■urftee  of  tl»e  cortex  »  a  thin  layt^r  coiuisling  of  neuroglia  only. 

§  6U.  Tli<-  nvr%'0-cclU  of  tho  abov«  nm'enil  kind^  arc  arrangml  more  or 
k»  dislinrtly  iu  l»yer<  parallel  to  the  aurfiicv,  so  that  the  whale  th!cknn««  of 
tlw  cortex  may  by  nicniu  of  them  bo,  more  or  less  successfully,  divitUxl  into 
«  Mntn  of  lonos,  one  above  the  other :  atid  wc  may,  as  we  haw  said,  n'vng- 
nbt  on  ibe  one  lumd  a  general  arrniigenienl  oomtnon  to  the  whole  stirfacD, 
Ukd  ma  the  other  hand  mod  ill  eat  ions  existing  in  theseverHl  region*.  The 
generul  arrMigoiiMint  miiy  be  said  to  bo  one  of  five  layers  or  lones,  usually 
counted  from  the  surface  inward. 

The  fifth  layer,  lying  next  to  the  (-enlral  whitfl  matter,  fairly  uniform  in 
chamctera  and  thickness  (about  1  mm.)  over  lh«  greater  part  of  the  brain, 
is  cbaracteriied  by  the  presence  of  eomewhat  sparwlv  scattered  "  fusiform  " 
cells,  though  other  branched  cells  are  preaent.  It  is  broken  up  into  vertical 
columns  by  the  bundles  of  vertical  fibres,  and  its  demarcation  from  the  white 
matter  below  ia  somewhat  indistinct  owing  to  the  fact  that  in  the  brain  tlte 
white  matler,  eapeeiolly  that  lying  beneath  the  cortex,  coniaina  cells  and 
small  gruupa  of  celb  Wing  between  the  bundles  of  flbree  to  a  much  greater 
extent  ihau  don  the  wuite  matter  of  the  spinal  cord. 

The  fourth  layer,  lyiug  abure  tlie  preceding,  varies  much  more  both  in 
tltickiMW  (0.&&  mm.  to  0.13  mm.)  ami  iu  its  cliaracterB.  The  constituent 
celb  are  on  tbe  one  hand  lar^  pyramidal  cells,  and  on  the  other  hand 
"granule"  or  "nuclear"  cells.  In  ■'ime  n-giona  It  may  he  aubilivided  into 
twu  layen,  the  araall  "  nuclear"  cuUh  tii-iiig  »>  iiliunituut  as  to  form  in  the 
up|i«r  {lart  of  the  layer  a  M'iiarnt«  Inyi-r  cnlUil  the  "gmnule"  or  "nuclear" 
layer.  Thin  fourth  layer,  Itkn  [he  pri-ctnliiig  filVli  layer  beneath  it,  is  split 
up  into  veriic-al  columns  by  the  bundUu  of  vrriii-al  fibril,  but  to  a  less  degree. 
li  is  marki^l  in  ibi  loner  part  by  a  horiitonliil  xlrvAk  <luc  to  numerous,  mostly 
liDe.  niedtillnled  fibnn  running  horiximlalty.  Iu  ihi;  c>irttoc  of  the  island  of 
Rial  this  horixoiilal  larc^r  i«  ilcvrlo|H'<l  into  a  cotispiciioiis  iihcet  of  medullatetl 
fibrea,  separating  the  rourih  mid  lirih  layen  hy  ii  iliHiincl  interval  of  obvious 
while  matter.  This  fifth  laver  of  fuiiifonu  celU.  thus  ik-taclied  fri>m  tbi.;  rest 
of  the  cortex,  is  what  is  called  the  nhutfrum  (FigH.  IDS.  I'M,  r/.). 

In  Ihe  third  hiyur,  the  constituent  c«lts  are  the  ctiarocterislio  pyTamidol 


t'l  till,  bill  froiu  the  usili- 
itself  mid  the  ^viill  ufili. 
lint  occasiDiiiilly  ti'iicoi' 
ciivity  of  the  nrlifii'ijili'. 

The  "cniiill  ]iyriiini 
the  tells  are  ehiir:ii';r  ■ 
iii'L  60  liistiiK't.  I>v  r. 
liMfe^ws  wliii'li  in. 
imwever,  of  ii    lui-' 
wmteil. 

Other  iicrvi-i- ' 
ami  of  tile  iii[< .  ^ 
liir,  not  of  \n  t  :• 
may  l«  eli!ii:ir 
not  pnee(.'!i>  ill!  ' 
(leinoiistniti  <l 

Anothi'v  ' 
the  ciiiiiv 
)iill)reil   al 
The  h.M- 
vatuiT  "1 
surthi-i' . 

Siil! 
whifli  ■ 
etiiiii'i 
hill  I' 
kiii'i 
n';:i 
mil-' 
t'ii'  ■■ 


RATrniS   OP   THE   BBAIN. 

nam  and  In  tlie  monkey,  tbuugli  iml  in  some 

nlilni)  ill  very  definite  clusUra  in  tbe  motor 

•  ■•■■l  region.     In  thit  oovipita)  TVgian 

..    -Murth  laver  13  very  conipjouumt,  miid 

iiivJullAteil  iibrea  preBenl,  tbrmn  11  while 

:  ibtt  motor  region,  the  nrnui)fi.'iui^iit  it 

ihtv<>  i)cHcril>u(i  H-i  till!  gi'iicriil  [iTiui.    Tbe 

i.iii  k''<:,  iiH  in  aliiu  tlu'  ftmrtk  liiynr;  )>iit  the 

iiH'ti  thinner  ihuti  in  tlii;  moinr  rv'gioii,  as 

I'liirlh  hiyvr.  whilir  thr  Rl'ih  layer,  thiit  o( 

I'Tu,    Smiiil  '■  iiiiclfJtr  "  wlU  arc  iK-rbn]* 

^'hijut  nil  l*y<T»  than  in  tht?  mi>U>r  region, 

111  ill  thp  ocopital  rcgiiin. 

lie  iraniiitiiin  iii  «triK-turc  from  one  region  to 

'i:tr]>  nixl  ili»liii<7t,  dnil  in  pcrhn|«  mpwially 

ilor  region  Imrkwanl  to  tliv  occipitnl  rcgioD. 

jiiiie  htRtoTogiolly  the  limit,  for  inatAoce,  of  tbe 

I  fx  peri  mentally. 

I   '  Iiritin,  lor  innUincc  in  tho  olladory  bulb,  of  which 

.  I'fv  grenl  modihcationH  of  the  general  plan  may  be 

,_.      \Vo  cannot  enter  upon  those,  but  nnjiy  just  refer  to 

I  iir  bififtomnipUB.     At  the  ventral  end  of  the  ternporat 

a^wanipi,  the  atruclure  of  uhoie  cortex  follows  the  tceneral 

Jrtiril  »o  ua  lo  project  into  the  cavity  of  tlie  desceodins  horn 

Evrlcle,  fiiriuing  the  rid|{e-like  prominence   known  hv  the 

liubstance  of  the  cornu  ammonis  is  therefore  cortical  8ub< 

the  side  uf  the  ventricle  by  a  thin  prolongation  <if  the 

J*r,  which  i*  in  (urn  covered  by  tbe  ei>t^ndynia  linina  the 

ticnl   w-i-tion  uf  this  substance  &hows  that  while  the  tiHh 

I  nrv  rcdiicMl  tu  ^mall  dimensions,  the  thini  layer,  that  of 

Fcclls,  in  w«ll  devoluped,  though  narrow.     The  celU  are  large 

*]«np,  Biitl  the  tajwriiig  proi-eeaa  are  arranged  »o  n^gnlarly 

t;uillr  in  iitatned  pregmratioaa,  to  a  marked  radiate  apjH^r* 

■t  of  tlH'  second  layer  there  occura  a  large  lievelopment  of 

ttb  and  a  sair(!en««s  of  oells,  giving  riae  lo  a  "  lacunar" 

^dihI  ili«  lir^t  (ir  m<i!ecular  layer  is  uf  some  coDHtilei«l>le  thick* 

I  Ihe  prominence  i>f  the  jiymiuiilat  cells  in  thiii  region,  tho  third 

enemi  plan  of  llie  cortex  ha«  Hom«tinie8  been  spoken  of  as  the 

'  the  cornu  uninioniit." 

he  prvsent  Htat«  of  knowledge  it  t*  imixjiviible  to  conw  t^)  any 

onclusion  cnnovrning  tho  meaning  uf  thn  vnriuty  and  arrunge- 

FcellsaHd  other  con^ttitiicnte  of  the  CJirtex.     Tbo  cells  with  their 

nerve  fibres  and  the  nerve  lihrils  form  a  network  of  gray 

we  may  compare  with   tbe  gray  matter  uf  the  epinal   cord 

(btch  is  obviously,  iw  wc  might  qxpocl.  far  more  complex  than 

We  mnv  conclLido,  and  experimental  oMorvation  oonfirnis  the  con- 

,  tlie  large  pyramidal  oolls  irilh   recogniinble  axi»-cytinder  pro* 

■B  trophic  centres  for  the  fibrm  which  appear  to  slnrt  from  thein. 

t  may,  though  with  Ices  confidence,  explain   the  large  vize  of  thcN 

kibe  motor  ref^on,  by  the  fact  that  they  give  ri^fe  to  fibres  of  the 

tract   Mrett-hin;;  a   long  way  from   their  origin  in  the  cell,  and 

demandiuji;  gr«at  nutritive  aelivily  on  the  part  of  the  cell.     We 

ape  ttlX)  conclude  that  these  fibres  are  efferent,  motor  flbra,  ilee- 

tnj  impulttes  from  the  cortex  to  the  peripheral,  or  at  least  dtataot 


806 


THE    DHAIX. 


celU.    TlicK  are  for  ibe  mrnt  p«irl  iur\cv,  (luxi^h  dimiiiUliini;  in  m 
lieliiu'  ii|>warrl.  ami  the  layer  Iiua  I)c«ii  rutleil  i)i«  "  layer  uf  larjte  jiyr 
calls,"  lli(iii)(li  in  cenain  ivt.'iuii!i  tlw  largM  pymmldnl  nlla,  ana  notaUyl 
giaot-celli'  an^  fotiml  in  (Ix:  [irecedine.  founb,  layer.    Tho  celb  are.  on 
wImIc,  acattenil  M)tnim')iat  ii)iar><rl}r,  ImKi^h  Irwiutnlly  f^utliureil  into 
ffr»up«,  auA  unionB  tWm  orcur  iiinall   "nuclrar"  aiit)   nthcr  vvlU. 
DuiMlliHt  of  Vfrliral   filir!.-*  r>{)rMi<l  out  rapidly  id  tbi*  layer,  ao  ibat 
culumnar  arrniigcmi-iit  1wg"iui'«  liift,  unci  many  of  lliv  fibrni   umlnublHilJ 
Ik-odioc  uxi»'Cyliii<K-r  jin>cr«H'»  of  the  fiyramidal  cclU.     Thoiigb  llw  lay 
varitit  in  thioltm-iw  (1  mm.  toU.4  mm.),  and  in  w^mv  of  ilx  ft^tiirx-H  in  diffirnOI'^ 
re^on*.  tlio  chamctcrifttic  pvramidal  cvliK  arc  prcHiit  over  th«  wIkiIc  (urDuir 
of  the  hcmifphert-.    In  tbc  loner  pari  of  the  layer  a  MMnd  hurixooial  aimk 
of  cliMfcly  interirovoD  horizontal  tibrr*  freijncDtIr  make*  ita  appaamwa. 

Tile  Bcconil  layer,  {•cuernlly  a  thin  one,  tlnni^h  vnTvinij;  from  C-  "'       i    '  > 
0.7ij  mm.  in  thicknew,  is  also  formed  by  pyramlilitl  cclli^  Ixil  ittdi- 
fruni  (lie  layer  below  by  the  nbwnce  of  largo  and  medium-siMti  cclU  ouU  l</ 
(lie  ptMonce  of  nunien>uH  small  <«ll8  cluaely  packed  together;  it  hw  btia 
called  "  ibe  layer  of  »mall  pyranmlitl  celK"     A«  we  have  said.  ihcM-  tninllR 

Iiyramidal  cells  dilfer  tonii^wiiiil  from  the  larger  oella;  and  tliv  ccU»  in  lb> 
ayer  are  Bomolin)e«  described  ae  ''an^fular." 

The  6rsl  ami  mi«l  uiijwrfiiiBl  layer  is  i-hflracterieed  by  tlie  pr«duainaMt 
of  Uie  noleeular  Kf^mud  Bub»taiice.  tite  vella  bein|[  few,  far  lietwoeD,  Mull, 
and  irrefcular.  The  k""'""!!!  subsinuce  ilaelf  seems  to  be  iin)re  Urgcly  w"- 
roglial  in  nature  than  in  the  other  layera,  and.  as  we  Mtd  above,  its  eiimur 
surface  appears  to  l>e  furnislii-d  by  neuroijlia  atone.  The  layer  i«  i^-iwnll' 
spi>ken  of  as  the  "  jM>rl|ihern]  "  or  "auperflcial  layer,"  or  aometimia  ae  thr 
"molecular"  layer.  The  tapcriiix  venlca)  p«i>cest*«e  of  the  pytaiuiilal  crIU 
may  be  traced  into  thin  lever,  wliicli  indeei]  varies  in  thickneas  aceurdin^  lu 
tbaabunduiice  of  pyriimiilal  ccIIh  in  the  subjacent  layers ;  num«raiu  su*>- 
what  6nir  me<liillut«Hl  tibriM  atxi  traverse  it  iu  a  honEuuial  direction. 

$  662.  Till-  ^neml  arrangenKiit  juM  dencrtbed  variot,  as  we  have  said,  in 
dilTercJit  r<-gi<>n*  of  the  cerebral  nirCue.  We  must  eonieat  ounelvca  bnr 
wilh  pointing  out  the  eluinict«rialk«  of  two  or  three  ini|Mirlaut  regions. 

The  region  which  w«  have  (§  tfSS)  callcil  Um'  '"  niotiir  an'a ""  or  *"  rppM,' 
is  charactcri/«<d  on  ihc  one  hand  by  the  gnvt  ihlckuuM  (1  mm.)  of  ihr  thini 
layer,  thai  of  Inr^  pyramidal  cells,  as  acll  as  by  I  bo  number  aiiij  siceoftlK 
cells  contained  in  it,  and  on  the  other  lumd,  and  ctpcdaltv,  by  the  prMni- 
ncnce  in  the  fourth  Inver  of  remarkable  clustere  of  very  large  pyraniiibl 
cells,  of  the  kind  which  are  ntferr«d  to  above  (§  OftO)  as  being  friM|otuitlr 
called  "ganglionic;"  ii  is  in  this  region  tlial  "giant  celts"  ura  rmindin  ik* 
fonrih  layer,  namely,  in  the  up|>er  part  of  the  proceutral  and  at  the  Hmniil 
of  the  poetceninti  convolution,  and  in  iho  |)anicc»tnil  lohule,  aoC|ulriflg  thfst 
grtUatt  eixe  at  the  lop  nf  the  precontral  convolution. 

The  occipital  rej^ion  a  characterixed  by  the  prominence  of  the  "  gfasalt" 
or  "nuclear"  cells.  These  not  only  (brm  a  dMinct  rlivbion  of  the  foat^ 
layer,  but  are  stiio  conspicuous  in  otiier  layers,  their  arrangement  beiai;  tart 
tliat  some  anlhon>  have  been  led  tn  divide  the  cortex  of  this  region  iutow"" 
or  even  ei^ht  lay«-rti.  In  ihe  present  state  of  our  knowledge  we  awv  bo  oiu- 
Icni  wici)  in.iintiiijt  that  thii  great  mark  of  tht»  uccipilal  n^ion  is  ue  abun- 
dance of  thi-w!  nmall  "  nutdtrar  "  cells,  toother  with  Other  small  "  anguUt" 
cvlk,  whnn^liy  l)<c  |iynirriidul  celU  sieem  to  Iw  made  less  con^pieuiin*.  It  i* 
worthy  of  iiotii-e,  however,  that  in  the  third,  but  more  eapecialty  in  tlw 
lourtb  layer,  n  t'l^w  er-U*  of  verv  lar;ie  um  are  met  with,  which  by  thrir 
large  branched  c<-ll  luhiitunce  luxl  conapicooun  axtveylindcr  pmotM  rweaibir 
the  large  cells  in  the  motor  rrgiim;  hut  it  Uiuuld  be  notvd  llinl  whilMkos 


SOME   IIIfiTOLOaiCAL   rKATITBSe  Of  THB   BRAIfT. 


„  cells  occur  (itl  least  in  man  Mod  in  ihv  ni'^nker,  (l)i>ut;Ii  not  iu  s'>in« 
ipf  tlw  lower  KiiimnlH,  sa  the  nbbit)  in  very  definite  clusters  iu  tiie  iikHot 
region,  ibey  oceur  ain^lv  ia  the  occipitfll  r^ion.  Id  this  occi|nl«l  rvKiun 
Ibo  layer  of  hoi-iifintai  Abres  iu  the  fourth  larer  is  \'ery  oonajiicuoaiB,  ati<l 
jtwiar  to  the  number  of  ordinwir  medullmted  nbr«e  present,  forma  u  while 
pumk  Tuible  eveo  tn  the  naked  eye. 

t  In  tlw  firoBtal  region,  in  front  of  llie  motor  reigion,  the  arrancreuedt  b 
inore  ia  aceordauce  with  wlial  we  have  described  aa  the  ^neral  plan.  The 
|wo  pyramidal  layers  are  well  marked,  aa  is  also  the  fourth  layer;  but  the 
layer  of  large  pyramidal  cella  in  much  thiiiui-r  Ihaii  in  Iht:  motor  re^jpon,  as 
|b  also,  though  to  a  Um  extent,  the  fourth  Inyer.  while  the  lltlh  layer,  tJiut  of 
jfbaifonn  celU,  it  tluekerthanuWwhere.  Stuull  "  nuelear"  celli  art:  prrhapa 
■nore  abuudanl  in  ihia  rcgi»ii  thn)ii;|!;h()Ut  nil  layer*  than  in  the  motor  region, 
but  an  (kr  le»  oau^ivuouH  than  in  the?  ocrlpitnl  reifiori. 
I  We  may  here  remark  that  llxr  truiiaitiim  in  viniotnre  from  one  re^cion  to 
■nother  U  very  [^niiliiHl,  nut  Khurp  and  di»tuii;t,  and  i»  p);rhnn»  avprcially 
Cradaal  in  piutiiii^'  from  the  motor  region  bm-kwanl  to  the  oc.'ei[M[jil  resinn, 
Pt  ia  not  [HinibU-  t^)  reco|rDize  hiMoTog^irAlly  the  limit,  for  inxtanec,  of  the 

r*>r  n-jpiin  lu  dvUTminea  eipcrinifnlally. 
In  ais^tial  rreiona  of  the  brain,  for  inittanoc  in  the  olfactory  bulb,  of  which 
fire  ahnll  «|K:nk  uUor  on,  vorv  grcnc  aiodilicutioiM  of  the  general  plan  niiiy  l)e 
Iphiierruil  in  the  cort«x.  We  cannot  enter  uimn  these,  but  mny  just  refer  to 
the  comu  ammunis  or  hippocampus.  At  the  vontrol  end  of  the  temporal 
lobe  iKe  eyrus  hippocampi,  the  structure  of  whow  cortex  follows  the  general 
plan,  ie  thrust  inward  so  ne  to  project  into  the  cavity  of  (be  dowending  bom 
Af  th«  Inicnil  ventricle,  formint;  the  Hdgeltke  prominence  known  bv  the 
Bbove  Itame.  The  substance  of  the  ooniti  ainiuoni*  is  therefore  cortioal  siib- 
Manco  covered  on  the  side  of  the  rcntrii-!e  by  a  thin  prolonj^alion  of  the 
^entral  white  matter,  which  is  in  turn  covered  by  the  cp<:iidynia  lining  tlie 
IveDiricle.  A  vertical  section  of  this  substance  shows  that  while  the-  lifth 
id  ftxirth  layers  are  reduced  to  emnll  dimensions,  the  third  layer,  that  of 
lUrKo  pyramiilal  cells,  U  well  developed,  though  narrow.  The  cells  are  larM 
'  r«narkably  lon^;.  and  the  tapeting  proeenee  an  arraOKed  n  regularly 
to  give  tifie,  es|>ecially  in  staiuM  prepantioDa.toamaHted  radiate  appear^ 
loe.  At  the  lerel  of  the  second  layer  there  occurs  a  large  development  of 
pillary  bloodveaidB  and  a  ecarceiMw  of  cells,  KivioR  rise  Ia  a  "  tacanar  " 
.p[«aniuoe;  and  the  finrt  or  molecular  layer  i*  of  some  considerable  ihick- 
bcM.  From  tiie  promioenee  of  tJie  pyramidal  celU  in  thia  region,  the  third 
^yer  in  the  general  plan  of  the  cortex  liaa  Bometimes  been  spoken  nf  as  the 
"  formation  of  the  cornu  ammonis." 

§  663.  Iu  tlw  preaent  state  of  knowledge  it  is  impoastble  (o  come  to  any 
MJtfacUirv  eoucluHon  concerning  the  meaning  of  the  variety  and  armiige- 
Deiit  of  tlte  colli  and  other  couatituenla  of  the  cortex.  The  oelU  with  their 
brancbc*,  the  nerve  6bres  and  the  nerve  fibrils  form  a  network  of  gray 
matter  which  ne  may  oumjMre  with  the  gray  watiex  of  the  vpinni  oortl 
i%  MO),  but  whi<;h  ia  obviously,  m  we  might  exnect,  far  mom  complex  than 
llhat  i*.  We  mav  eoncludc,  nml  (■xperimental  omervntion  confirms  the  con* 
Iclusion.  thill  the  lar^c  pyramidal  cull*  with  recognisable  axi^i-eylinder  pro- 
'  asee  Mrvc  iw  trophic  cculrux  for  the  hlim>  which  appear  tii  atart  from  llieiD, 
nd  wo  may,  though  with  hw  cutifidi-nce,  cxpiaiu  the  lai^r  »jtt>  >if  tlwiw 
b  in  the  motor  region,  by  the  fact  thai  ihcv  give  rinft  to  fibrvn  nf  tliu 
ramidal  tract  slretcliiii<;  a  long  way  fmm  tdcir  origin  in  the  ci'll.  and 
ereforv  demanding  great  nutritive  activity  on  the  |)itrl  of  the  cniH.  We 
lay  iwriiaps  also  conclude  that  iheae  fibres  are  oAbrcnt.  motor  tilire*.  >i(*- 
'  to  csury  impolsM  irom  the  ooitex  to  tbe  peripheral,  or  at  Icuat  distant 


TnB   BltllN^. 


mechan!am  Ibr  the  executiirn  of  thow  mivementd  ia  rcadv  «t  hanl  in  itie 
brain,  wnilin^  only  Ui  hi  d'txharfied ;  ami  it  u  euy  tu  ooouelve  how  »ii<rh  ■ 
diNfliiirKe  nii|clit  oe  iilfecled  either  liy  Uw  uibKitutiun  for  tliv  urill  of  wmc 
])(>tvtit  iniriiiiic  niTviviil  irtipulM:  or  l>_v  «uiii«  niifdirnclioD  ul*  ToltUonal  iia- 
)>iiIm«.  PenciiiA  wbo  ban-  experienccl  iimilar  forcci]  iuovenivDt«  u  llin 
retull  of  dWttw  repoM  tliat  they  nrc  freiiuciilly  MicompAniod,  niwl  aoaai  la 
be  CBUwd,  b<r  liiMurbLtl  vUual  or  other  sciualiotu ;  thu*  llwy  ituribuU  th^r 
KiiililL-nly  falling  furwunl  li>  ihi^  (lociirrtucc  of  tiw  KimtiaD  ihdC  thr  Ki^mnd 
in  friinl  of  ibuin  i»  MiiMcnly  linking  away  bonoUh  their  (mU  ^^  ilbuut 
IruDlin^:  too  cluHoly  to  tbn  intvrprHuliniui  thu  xubjvcU  of  thaw  dUanlvn  fpwt 
of  ihcir  own  fi.*cliiig*,  and  rcmcmlxTing  what  wa5  saii]  above  OoncvrniDg  Ttr- 
ti)fo,  ««  may  at  Ii-wt  coni:liiil«^  tbni  th<>  nnuaitnl  nvivvmrntit  art-  in  aiaaj 
cues  due  tu  n  ■limirikr  of  the  cucird  inn  ting  nK-clii>iiUni.  bmugbl  abocii  hy 
stTBDge  or  disordered  statmry  im\m\»vs-  Ami  lliin  vit-ir  i»  Miiipurtnd  b_r  Uis 
Jkct  ihnt  many  of  thvne  forcvd  ni<jveincnt»  aro  aco(im]>anicd  by  n  [icruliu 
■ii't  wholly  abnormal  piwilioii  of  the  ryes,  whii-h  alonu  might  peramfm  tx^Ham 
manv  of  the  phrnomcii:i. 

§  647.  The  phetiomrnn  presented  by  animals  d«prircd  of  ihoir  ccrabnl 
hemiAphiMTV  show  that  llii#  niuchinfrv  of  coordination  is  supplied  by  cerebral 
structures  lying  l>^lwccri  tha  cerebral  hemisphere  above  und  th<;  U>p  of  tbt 
spinal  ourd  bi-loiv.  But  when  ivc  ask  the  further  qucstinn,  how  ts  thit 
luacliinery  related  to  the  various  elemeDts  which  go  to  make  up  this  pan 
of  tJie  brain?  the  only  answers  whieJi  we  receive  are  of  tiie  moat  imiieriiwi 
kind. 

Jd  the  case  of  the  fro^  we  can,  afier  removal  of  the  eorehral  heniiitphi^rc*, 
make  an  experimental  dutiuction  in  the  {lartJt  left  bvtwci^ii  the  optic  llialoaii 
witJi  the  optic  nerves  and  tracts,  the  optic  Inltee,  and  the  bulb  with  the  ruili- 
tucntary  ccrcbi-lluni.  Wtien  the  optic  thiilami  ari>  removol,  as  might  bs 
cx|H'4-lL-d,  tbu  evidence  of  visual  imprca*ioiM  muilifying  thu  tnorcmenta  of 
tlie  animal  diMpjieant ;  and  it  is  .stated  that  apparently  3iponUi»<--jus  mow- 
tuents  are  mudi  more  rare  than  irbcn  llit-  ihalunii  arc  intact,  Whi-ti  tbe 
optic  \chtt  B»  mil  lu  the  cerebral  bemi»i>hcw-«  are  retiiuvc.il,  Uio  power  of 
udanciog  is  iMt ;  wlien  itiich  a  fro^  is  Ihmwn  otT  its  biihineo  by  incliniag 
the  plane  on  whirh  it  in  phut'd,  it  slips  bock  or  fnll.t  down ;  the  special  o>- 
ordinaling  nifchuDism  for  tuaUncing  must,  therefore,  in  this  iiuimal  havst 
efwcial  connection  with  the  Ojttic  lomM.  liui  nflcr  removal  of  thcw  oritaiM 
the  animal  is  still  cupalile  «f  a  great  variety  of  cuontinate  niovecnvnu; 
unlike  a  fmg  retaining  its  spinal  coni  only,  it  c«u  swim  and  Icnp,  it  miiB- 
tains  n  normal  puMur*.-.  and  when  iilaccl  ou  its  baek  immediately  rcgaini 
the  normal  posture.  The  cercUclliim  of  the  frog  is  so  small,  and  in  n- 
moving  it  injury  is  ki  likely  to  he  done  to  the  underlying  parts,  tiiat  it 
becomes  ditlicult  to  ny  how  much  of  the  coonlinatiov  apparent  in  a  fny 
noasctning  ccrchclluni  and  bulb  is  to  be  attributed  to  th«  former  uriotlic 
latter ;  probably,  however,  the  part  playol  bv  the  former  is  small. 

Ill  thu  case  neither  of  the  bird  nor  of  the  mammal  hare  vc  any  rxMl 
iulorniation  as  to  the  behavior  of  the  animal  after  removal  of  iIm)  poitt 
behind  the  hemispheres,  in  addition  to  the  hemispheres  ttieiuselru.  Our 
knowledge  ia  continetl  to  the  results  of  the  ablation  or  of  the  Btiiuutallun  t^ 

Earts,  tbe  cerebellum  for  iustance,  in  animida  in  which  tbe  rest  of  the  brain 
U  been  letl  intact.  Ubeervaliims  of  this  kind  have  di^eluKd  many  int»t> 
eating  ftcts,  besides  the  forced  movemeuts  juAt  referred  to.  but  Ihcy  liiive  uiil 
led  to,  and  indeed  could  hardly  be  ex|>ecled  to  lead  to,  any  clear  views  as  to 
the  point  which  wo  are  now  ilisL-ussin){.  It  doa  not  folluw  that  every  ]«rt, 
injury,  or  stimulation  of  which  interferes  with  coordinated  muvemt^nts,  or 
gives  riae  to  de6nite,  forc>ed,  or  otiter  niorementa,  ii  to  be  cunsidored  as  pan 


I 

I 


I 


of  thr  Diacbinery  uniler  coiuiderntioii.  Tlie  cnrponi  stristft  and  cerebral 
hrniu|>b«rt*  ruriu,  lu  vr«  ha\Q  aceii.  u<>  pan  of  ih«  luaobinerv.  yet  injury  tu 
llim)  mny  (li.i'trtk-r  ibi'  mAcliint-rv  ;  tiiic)  lb«  fact  lliul  reniaval  of  ur  injury 
tu  tbe  ctrcbc-Uum  •lisonk-ra  the  nmoliinerv  a  do  pruof  by  iUelf  (bat  tli« 
co/rlii'llutu  i*  lui  uaeutia)  |iart  til'  itid  luucbiuery. 

]  f  nv  may  Irum  t»  iloluclionii  fruni  alructurul  arniiijteinenU,  ira  mi|{lit  be 
incliiiril  to  infer  llint  the  luiatoRiioal  relatioutt  nf  what  ve  Iiave  milvd  the 
Ici^M-iitnl  rcKtuo  from  tli«  bulb  unniirt)  poiiil  to  ita  scrviiij;  at  tlw  fouudiuioD 
ol  llii'  iDiicliiDeiv  ID  (lUMtioil.  twhiud  it  hiu  full  conncctiun^  with  vaHitua 
|mi(n  ui  ih*  rani,  while  iu  iVunl  by  mtaiu  t>f  Iho  otitic  ibulumi  and  atiierior 
Nrfxira  <iua<lrigoioiiia.  if  not  by  other  wuyi  a«  k«1I,  it  tt  itu  far  luuoL-iatutl 
aillt  tliu  optic  lu-rve*  that  tbc  pricb  »i«nii  njieu  fur  visual  im[>HlM»  Ut  fniin 
si-cv-M  tu  iu  Tu  thia  luuiitiatiQii.  Iidwcvit,  vr«  muNt  ad<l  thu  nrcbdluui,  nn 
aivouiil  »r  i(*  rvliiliont  to  it,  to  Ihu  iNird,  and  ti>  the  lulb  through  th«  nnti* 
form  If  xlicf.  inoludinz  ila  tin  with  ihv  iiudilory  nervt:.  And  it'  we  add  the 
cvrpln-lltini  WK  miiat  also  probiihlv  add  th«  |>i>ii:<.  W«  may  sxcluda  tli«  pea 
of  thi-  cTiii.  Finer  this  ic  compoM-d  cxclu»ivcly  nf  Gl>n«  bringia^  tbe  cerebral 
I>dni<[ih<'rc8,  including  iIm  oonxirii  ctrialK.  into  ci>it»<?ct)on  with  thi?  |>i<n<i, 
bulli,  ami  conl,  nnd  m  with  tbc  cuonliiintiiig  niiiL-hiiii.Ty  itaclf,  n*  well  n* 
with  i<lli«r  {wTis  of  iho  nervous  mtcni.  And  ob<crralk>ii.  im  fat  i\»  it  gov*, 
auii|Miri8  this  iJtduclioit  from  nnaiomical  relationship*.  We  will,  however, 
iitivT  tihiit  eiee  wc  have  to  say  on  this  point  until  alt«r  Kfi  hav«  dUcuncd 
tile  carrying  out  of  VoluDUry  niovemcnis. 


Ox  SouE  HnroLooicai.  Fkatureb  of  the  Bkaisc. 


I 


I 


$  648  TIk  while  matter  of  tbe  brain,  ns  we  have  niremly  said,  like  lliat 
of  Ihv  >[>iiial  cord,  comi*taof  medullatcd  fihrca  of  varlout  tize*  imbcildctl 
in  ni'uriigiia  niii)  Hui>|H>rl(M!  by  iM;]tta  of  eonnvclive  timue  (k-rivud  fnini  the 
pia  oialrr.  Savo  loat  cvll>,  or  even  gronjin  or  ron*  of  (.-i-IU,  fur  the  IDOK 
part  vmnil  e«lb,  about  mmtv  of  which  it  may  be  dcbalctl  wlu:tlivr  tbey  U» 
aervfe-colb  or  neuroglia  ei,-ll*.  arc  fiwjUiMitly  nccn  between  the  filma  ami 
bniidlca  of  fibres,  the  white  loallcr  of  the  brain  M«ni  tncoiially  iileiitic«l 
vith  that  of  tbc  Rpinat  or^. 

The  gray  matter  of  the  brnin  in  etDeral  also  cormponds  to  tbe  gny 
Rtattcr  of  the  cord  in  coiiMfliiig  of  brniiching  ne^vc-ccll^  fine  inr<liitlau>il 
fibm  of  |>rciilinr  nature,  noiMiirdullatcd  Kbm  and  lihHls,  with  a  Ivw  unli- 
narv  nicdulhiteil  tibm,  all  eupjMirled  in  neuroglia. 

I'hc  "  ocotral "  gray  mnlter  u  cxtrvmely  like  that  of  the  ootd  except  ibal 
the  ncrrou*  elemeno  arc  imbedded  in  a  relatively  larger  ({uantiir  of  m-u- 
roglia.  Immedtatvlr  undenicath  tbe  epithelium  lining  ihceei'eral  vciitriclca 
and  tbe  aqueduct,  tbe  neuroglia  ia  especially  develo|>ed,  forming  a  distinct 
layer  whicb  may  be  rcgiinU.^  at  a  continttatiuu  of  tbe  central  g«hitiuous 
aulMiuncc  of  the  spinal  cord,  and  which,  with  the  epilheliura  overlying  it, 
forms  what  is  known  as  tliv  tpemtyiMa  Tbe  "  nuclei  '  of  (be  cranial  iiervw 
are,  as  we  liave  seen,  companible  to  tbe  groups  of  nerve  cells  in  tlic  si^iutl 
cord. 

A  K'^*'  <'^  '^^  ^^^  ff"'T  matter  of  tJie  brain  may  be  apokeo  of  as  more 
"ditliivc"  or  "  st-attered."  more  broken  up  by  bundles  of  fibres  than  is  the 
case  in  the  spinal  cord.  Tbe  "reticular  lonnatioD"  of  the  b.ilb  and  of  tbe 
iegai«tital  rei;ioii  is  an  eilriiue  furin  of  this  dilfusc  t;ray  matter  And  even 
in  web  collediotia  of  indubitable  gray  maiivr  us  tl»e  enrjMi«  sirtatiiin,  uptio 
thalamus,  and  the  like,  the  pure  gray  matter,  if  we  may  um  tlie  term,  ia 
much  wore  interrupted  aiM  broken  u|i  b/  conspieuoua  bundhi*  of  white 


THK    DRAI^. 

flbrefl  than  is  the  case  in  any  region  of  thp  sfiinal  cord.  In  tUc  oorpon 
quiidrigcniiDB  to  Uw  gray  iitait«r  is  broken  u|i  by  »l»e«(a  or  bundles  of  mhkt 
matter. 

The  oi^rve-oent  of  the  aeveral  ciitlectiooe  of  (;ray  matter  are  not  all  dika; 
ihey  present  in  dld'ereut  re({ioni(  ilitTt^rences  in  si<e,  furm,  and  in  other  tftu- 
sclera.  The  cells  ot'  the  Ducleiix  caudatus,  for  instance,  arc  rather  small  ti>d 
oDeu  round  or  spindle-Hliaped.  whil«  ihoee  of  tb«  oulk-  ihslamits  an  larp^ 
broDchcd,  and  rich  in  pi^'iiicnt.  The  cells  of  the  sulwlnutia  uir,tn  ui 
■pindle-aba|ied.  of  inod«r»te  xuc.  mid  mi  luadtd  with  blaek  pij;nient  (iu  iiiu) 
as  to  jtuiily  ti>e  name;  thoiw  of  the  hioui  ai^ruleiiit  are  very  lar^e  and 
siiberi<-al,  iviih  juet  so  much  {%iiiGnt  as  tn  give  a  bluioh  tint,  liut  nui 
knowledge  of  the  lioer  hiMulogioi)  details  ut  ihe  rarioua  mosaee  of  k^J 
matter  is  at  present  too  impvrlect  to  aflbn)  auy  bsfiia  whatever  fur  jJir^ 
logical  deductions;  and  it  will  be  hanlly  [imfiinhte  to  dwell  u|wiu  tlicK 
Two  regions  of  gray  matter  alone  e«II  for  ipeciul  CMcrifitiou,  the  conn 
ccnhrl  and  the  superficial  gray  matter  of  the  cerebellum. 

The  mperfieiai  yrajf  matltr  0/  lAe  cenMiutn. 

g  649.  The  ifurfacc  of  the  cercbolluni  is  increased  by  bdnc  fgldsd  « 
plaited  into  Icnfliku  folds,  and  c4tch  of  ihcw  primary  Iblds  U  tinllulT 
folded  into  a  number  of  secondary,  nlso  leaf-like,  fbl<l*  or  lamttUn.  Eua 
of  ihcM  lamella)  consiets  uf  n  central  core  of  while  nmltvr.  the  fibre*  vT 
which  pn«8  inward  to,  and  cuiilrihiile  to  form  the  ocairnl  whice  niatlrr  of 
the  (i'n.'hclluin,aDd  of  a  supcrlieial  layer  of  grar  omtlcr.  A  M-ctinn  thpLOjti 
a  laniclin  perpendicular  to  the  »iirliice  shows  that  the  gray  matter  codmu 
essentially  of  two  layers:  a  layer  Iving  next  to  the  white  matter  formed  !«■ 
denevly  crowded  small  cells.  ealW  the  nuehnr  layrr,  and  l*tween  this  sad 
the  tiu|ierficial  pin  mater  a  much  thicker  layer  of  peculiar  nature,  aUledlke 
mottcular  laiicr.  Detncen  these  two  layers,  and  connected,  as  we  sball  M^ 
with  both  (j1  them,  lice  a  row  of  ver}-  larure  and  remarkable  cells,  called  dii 
k/I*  of  Fvrkiriji,  the  bodies  of  which  abut  011  the  nuclear  layer,  and  lbs 
loiig  branches  of  which  traveise  the  molecular  layer;  these  cells  so  ptiesd 
may  be  Mid  ta  constitute  a  third  layer.  Before  pmcce<liu]r  further,  we  maj 
b*re  remark  that  a  section  uf  the  lamella,  that  is.  one  of  the  seeoudary,  bM 
one  of  the  pHmarv,  folds,  while  Htill  remaining  a  vertical  section  (tbsl  it 
perprndicular  to  tlie  surliice)  may  be  carried  through  the  lantella  in  dillmat 
planet,  and  ibai  of  these  several  plation,  the  Mictions  Ukeu  in  two  uf  ihcia 
am  e«[H'('ially  inittructive,  onmely,  the  one  taken  in  what  we  may  Mil  tk 
longiinilinal  plane,  pasfJng  fKim'tbe  lop  «f  the  lamella  to  i|s  baae,  anil  tht 
one  taken  at  right  angle*  to  the  farmer,  in  what  nc  may  call  tl»e  tnuunroae 
plane.  The  nuclear  layi-r  and  the  molecular  layer  pn-eent  lb«  snina  brwd 
IVntumt  in  both  Imigituilinal  imd  Irnnsverse  n^-iiunn,  but  the  long  bmncbcd 
processes  of  the  celli*  of  I'lirkinj^-  >.ince  tbcy  run  in  the  tniitsveree  nlaue  an 
iidciiiialcly  fven  in  iransvctw:  sections  only;  longitudinal  seclioiu  soow  only 
their  proh'tcs. 

The  molecular  layer  is  of  a  peculiar  mlurc.  lu  manv  m<Nlci>  of  prenn- 
lien  and  in  ntauy  sections  it  appears  chietly  composed  ol'a  granular  or  avttel 
groutKi  Euhslance;  hence  the  name  molecular,  na  if  it  were  an  aggre|[Klioa 
of  molecules.  The  dots,  however,  are  sections  of  fine  fibrils,  some  of  wbtcb 
are  neuroglia  fibrils  hut  otbera  are  undoubtedly  nervous.  The  layer  eoOMlt 
in  fiict  partly  of  nervous  elements,  and  here  perhaps  even  more  than  elie- 
where  it  is  extremely  dilBeuIt  to  say  with  regard  to  many  of  the  eli-tueati 
wbrtlicr  they  are  neuroglial  or  nervous  iu  imiurw.    A  considerable  {Mrtioo 


fAL   rSATCBES   OF  THK   BBAIX.      801 

of  ibe  wholt  ana  of  the  iiifili.-culiir  litvur  U  lakeii  up  l>r  the  cniispicuoua 
bnntchtd  prwCMiM  of  iW  wUa  i>{  Purkiuje ;  «u>]  KcatlcnHJ  about  lie  numer- 
aa*  iinntl  cell*,  tame  of  irhidi  mi*  oeuroEli*  oella,  but  >om«  of  wl)ic)i  are 
iit)d<>iil>le>llj  Derv«-celb.  The  moit  conaMCtiouj  feature  of  the  \&ycr,  boir- 
KTor.  M  tlw  pmeon  in  lar)^  ntimliera  of  tli«  linu  fibrils ;  but  before  we  *p«ik 
of  thcw  it  will  be  diwntble  to  turn  to  tbc  cclU  of  PurklujA  nud  the  uuclcar 
Isrer. 

'The  »11  of  Purkinj*  ponxwn  n  Urge  (40  ■  by  SO  »<)  flatk-^haped  I»odj-, 
nirroiiMding  a  large,  cum imciioiml,  elm r,  rounded  iiucI«uh;  it  ha*  oiucb  ibo 
apprnrance  of  n  larzc  giinglioD  evil.  The  biMv  nf  the  fliwk  nal*  on  the  nuclear 
laTrr.  ni>d  frtiRi  it  ihcrc  proceeds  af  ingle  nxiv'CjliiKU-r  praorai  which  pwaing 
throurit  the  nackar  layrr  foioewbal  •ibli<)urljr,  nii<l  in  il«  piiatagi*  nnguiring 
a  BMOaila,3oJiia  the  central  uhiir  Hihoinnco ns u  mi-ilnltatoil  tilrn?.  The cell», 
■a  wa  have  aatd,  form  a  ainglr  laver  only,  hiii  riavr  ihin  vovcn  the  nttclcar 
layer  over  the  whole  of  the  lamolln,  a  cunvidcnible  iiumlx^r  of  the  (ibru  of 
tM  white  central  matter,  tltotigh  imlv  a  vpn-  (mnll  fracliuii  of  iho  whole,  ara 
Uina  ilenved  from  lh«ae  cells  of  I'lirkinji^.  Tbe  niirn)»r<l  nt-rk  of  the  flaik 
niDiiiD^'  outward  in  the  nioleculur  layer  divides  in  an  arboraceni  fitehion  into 
a  lar^c  niiiuber  nf  bmnclieB  nhicb.  fepreadiug  out  laterally  in  iIk;  tniii»verie 

itlane  and  iitretchini^  a*  far  as  the  MUrface,  rnniifv  through  (bo  tnolocular 
aver,  aiid  are  eventually  lost  to  view  aa  exceedingly  line  fibrils.  Some 
ooterTers  maintain  ihu  aoiDe  of  the  line  proceosee  are  continuous  nilh  pro- 
e»[B  of  the  small  nerve-eelltof  the  innleeular  layer,  but  this  is  not  a^liottted 
by  all.  In  any  case  llie  fibrillar  terminations  of  these  cells  of  Purltinjt^  oon- 
tribute  to  the  iine  jjbrils  of  the  molecular  layer. 

The  nuclear  layer  in  ordinary  stained  specimens  has  the  appearance  »f  n 
nan  of  nuclei  clueelv  crowded  totfetJier  in  a  bed  of  reticular  nature ;  aud 
•inco  tlie  nuclei  ttnially  stain  deei>Tv.  the  layer  Htands  out  in  stmng  conlraat 
to.tha  nnch  leas  di-eply  nluiootl  mulcciilur  layer.  Careful  emniuaiivn  with 
•|»cSal  modci  of  prcpamtiun  >hi>wit.  bowcTer,  tlmi  while  wnM  of  the  nuclei 
an  nuclei  bdoagiog  to  nL-tiroglia  and  bloodvcnwU,  ilw  majorilv  belong  to 
iinall  iwrve-fialb  of  a  pi-culiiir  nature.  In  tboc  cells  the  nucteuM  is  sur- 
rounded by  cell  solMluncr  mhich  fiirniing  n  thin  layer  iinmedialvly  anmnd 
the  nurleiii<.fschteIlydix|Hi*f<las  thin  r]>r«uiting  bmnchc«,woi«  of  which  end 
in  a  i>ci-uliiir  nrborceccnix- not  untiken  mii»>?le  rn<l-|>liilc:  thcee  prooevoe  oon- 
iributc  nilb  the  neuroglia  t"  fnrni  tlu-  rcticu  la  r-lo«  Icing  bed  spokm  of  above, 
Noprucewctin  be  Iruecd  inwiinl  to  the  central  while  mntler;  but  one  of  the 
pnoetees  gives  olf  a  branch,  which  piissing  vertically  outward  lakes  on  tbe 
appearance  of  a  delicate  axi> cylinder  prooeea  and  runs,  without  dividing;, 
into  ibe  molecular  layer  for  a  Ttiriablo  distance,  aometimes  reaching  clo«e  to 
llw  mrfacc,  but  nt  last  divides  at  right  angles  into  two  Hbrils,  which  mn  in 
the  hutgitudinnl  plane  in  opposite  directions  for  a  considerable  distance,  auil 
are  ultimately  loet  to  vtow.  ^incc  theae  cells  in  the  nuclear  layer  are  very 
numerous  nod  each  gives  rise  in  the  above  manner  to  longitudinal  6brils,  tl»e 
molecular  layer  is  traversed  by  a  multitude  of  librils,  visible  as  such  in  lon)n- 
tudioal  sections  but  appearing  as  dota  io  tronsvene  eeotioDS,  in  which  &e 
cells  of  l'urkinJ6  are  bc*l  displayed. 

BeaJdea  theae  longitudinnl  librils  proceeding  fmni  the  cells  of  the  nucleur 
layar,  epeeial  modes  uf  pn.'|iaruti'>n  HimiUrly  diH'Kiee  numeruuB  traiMvenM  aji 
well  as  more  or  lees  obli<|ue  librils.  Mitny  of  l))»c  »p|>ear  to  result  from  the 
branching  of  the  small  nen'e-cells  of  the  roiili-mliir  layer,  and  soow  of  ihoae 
ao  ariviiig  descend  ti>  tbe  layer  of  the  cella  of  I'urkiiij<!-  and  end  around  the 
bodiiw  ol  ibwe  cellii  in  n-nnirkablc  neat*  of  fibriU,  williout,  however,  actually 
making  connwlioiu  nilh  them. 

The  meduUatvd  fibre*  uf  Uw  ovutnd  nliito  matter  of  a  lamella  pas  on  all 


TirS   BRAIX. 


sidee  iata  the  nuclear  layer ;  or,  nut  in  uiather  wsy,  mctlullatt^  ftbrf*  pai* 
iiig  out  of  th«  nuclear  layer  at  alt  poials  converKC  to  rorm  the  ctnuml  •hiic 
matter.  Some  of  titeae  fibres,  us  ne  have  M«n,  bi^ti  or  i!!i>d  in  the  cWltor 
Purkinj^.  l^oue  uf  them  aji|icar  to  join  thv  ccIIh  of  Ihe  nuckar  lajM*.  and 
we  have  no  evidence  that  any  of  them  end  or  begin  in  any  way  iii  thr  nuelav 
layer.  A  certain  number,  hdwcver.  Hinr  l)C  *«vn  to  paw  ibmngh  tb*  noctrai 
layer  and  between  tlie  cells  u('Fiirkiiij<'-:n to  die  mulcrular  tayt-r.  triicrt  Unnc 
ihdr  medulla  tbey  divide  and  a))purcutt)-  cunlribulc  to  thv  numcroa*  fibrih 
of  ibe  molecular  layer.  The  prcnuroption,  iliercforc,  i«  that  all  iho  libn>  of 
Ihe  white  matter  by^in  or  end  eiilier  in  tlie  cells  of  Purkinji  ur  tlw  fibrili  of 
the  molecular  layer. 

The  KUperGcial  gray  matter  of  the  cenrbclium  then  naeniblca  the  pmj 
matlt-r  of  the  »))inal  cord  in  so  far  of  it  canRtila  of  braocbiiif;  nem  rcll^ 
nenc  tihnai.  and  nrrvc  iibrilii  inibi'ildrd  in  ncuroclis:  but  the  diapoaitiM 
and  fi-alurcM  of  the  »vvtTal  foctora  nn-  peculiar.  We  may  take,  |)erlMfa.M 
th<ikcy  of  the  ilnirturc  the  Bbrilsof  the  mdleciilar  layer;  this  layer  is  reU- 
Uvcly  verjr  tliick.  about  400  >,  much  thicker  than  the  nuclear  which,  bw- 
ever,  vmrica  in  thickncH,  bung  piutrally  tbicknt  at  the  top  »f  the  Ml; 
hence  Ihe  number  of  fibrils  in  it  may  be  epoken  of  as  cuormoua.  Hioe 
librilti  acim  certainly  to  be  ci>nn«ct«d  on  the  one  hand  witli  the  cells  uf  ike 
nuclear  layer  and  on  the  other  hand  with  the  scattered  ainall  c«11b  of  tfatir 
own  layer ;  but  we  bavc  no  evidence  that  these  two  sets  of  fibrils  arw  ooa- 
tinUQUS  with  each  other;  oa  the  contrary,  it  seetin  more  probable  thai  tbt 
two  seta  of  cells  represeut  two  indepeuHoot  syMema.  We  can  banlly  doult 
that  these  librils  are  in  functional  ouniiection  with  tbe  me«lullaled  iibre*'/ 
tlie  central  while  matter:  but  we  have  uo  clear  evidence  that  lite  iiT*t*m 
of  scattered  cells  is  continuous  either  with  ilie  cells  of  Purkinji-,  nud  *o  witk 
tlio  medullaied  fibm  belonging  to  thoie  celU,  or  with  the  luL-^lulhitt^  tibrw 
which  end  ii>d^DdeDlly  in  tho  uiolucular  layer;  and  wc  have  no  evidtao 
at  all  tliai  tfae  srMcni  of  the  cells  of  the  nuclear  laver  u  connected  >itb 
eitlwr.  Wo  Cflu  tiardly  think  othemiie  than  thai  llie  molecular  chants 
which  sweep  to  and  fro  along  the  laiiglu  nf  thtvc  fibrils  (whoae  nutriuua  i* 

EitlMibly  governed  and  hrncc  whoao  Atnotional  activitv  »  probably  r^uUied 
Ihe  nuclear  and  scattered  colls  r«»pMtJvcly)  arc  inducnccd  by  or  originate 
)  nervous  impulses  pauing  along  the  nH)dulla(4.-d  tihrcs  of  tbo  white  matter; 
and  henc«  we  must  conclude  thai  cither  a  c<Miliniiity  exists  which  has  as  vei 
««rai>e<i  detection  or,  what  is  nuile  possible  if  not  probsblc,  that  ooe  SGvi) 
mn  net  npon  another  by  simple  contact  or  even  at  a  disunce.  Fuitbcr, 
while  the  cell  of  I'urkinj'^,  with  its  large  cell-body  oud  nucleus,  its  oaiia|ilra' 
OUS  Kiiaoylinilcr  procew  and  its  other  branchml  proceeds  prceeota  nuuiy 
analogies  with  a  imitor  cell,  auch  as  thura  uf  ihe  anterior  bom  of  tbefptsal 
cortl.  and  raises  the  preaumption  that  the  impulsn  which  move  along  in 
axi*  cylinder  procesa,  proceed  outward  from  the  c«ll  as  motor  or  at  lea*t  ai 
•Akivtit  impulse*,  we  have  no  direct  jiroof  iliai  this  is  io.  And  though  it  it 
Umptiiig  10  luppoac  that  the  other  medullatcd  libres,  which  tike  thr  libra 
of  a  noatcrior  root  an  loat  in  the  gray  mutter,  witlioul  tlie  intervcniran  of  a 
r'>iH|>iouoiu  coll.  earry  aflVrcuc  impulse*,  we  have  as  yet  no  proof  of  ihia 
All  we  can  say  is  that  lh«  gray  niniier  is  eouuected  in  two  otflenut  trays 
with  at  least  two  sets  of  Bnm,  which  probably,  therefore,  bave  diOknuA 
funi'iioiu. 

We  may  here  add  the  remark  that  the  large  body  of  the  celt  of  Pnrkio^ 

lira,  ns  inlle<-d  du  the  other  nervous  elements,  in  an  appniprialo  spacv  in 

ft     >.:  I  :,f  neuro^'lia.     Itetween  the  surface  of  the  cell  and  the  wall  uf  nea- 

II  siwco,  generally  so  narrow  as  to  b«  [Hitential  ralhcr  than  actual, 

loll  uiiK'h  may  sometimes  be  consKleTablv.     \N  betber  small  ur  lai^ge  i|  ena- 


SOME  ntaTOLOGICAL  ?EATDRKS  OF  THK   BRAIN.      803 


imino  Irmpli,  awl  tlic  cavity  in  which  the  cell  li«t  ia  la  connection  wjlb  ibe 
Itmiiliatica  uf  llio  liniin.  KhcIi  cell  then  li«»  in  s  lymph-»pac«:  Itut  we 
merely  menti&n  tho  fnrt  uow ;  ive  nball  have  to  nrltirii  to  the  matter  when 
w»  eomo  to  <Ich)  with  ihv  lirmiiluklti;  luul  vascular  urmDgcnieiitn  uf  the  bruiu 
■ltd  splaal  flord. 

TA«  ftrrrfm/  Orfar. 

$  660.  While  (he  soperiioiHl  gray  matter  of  th«  ccr«belliim  does  not  differ 
atHkinKly  us  to  i in  bislolofjiml  fcalurcs  in  i.lifR.-rent  rv^ions.  very  considcfnblc 
difleffncn  are  observed  id  <liircr«iil  rcgiooe  of  tltv  cerebral  cortex.  A  gpn- 
ernl  plan  of  Htructurv  inny  perhaj^  lie  i«ro|;nixed,  but  as  we  pns§  from  one 
purt  of  the  cerebral  surface  to  another  we  Biid  n)o<liticstionB  continually 
lakinj;  place.  We  niuflt  content  ounelvea  here  with  atleinptiit^  a  deflcripiion 
of  ibe  funeral  plan  followed  by  en  indicatiiHi  of  tli«  more  otnking  charucter- 
latit*  ot  certain  regions. 

Tbe  cortical  grav  matter,  hating  an  average  thieltneee  of  about  3  mm.,  hut 
rar^'ing  Considerably  in  different  regions  from  l,»  mm.  in  «>me  ]Hirl«  of  tbe 
occipital  lobe  to  A.'i  mm,  at  tbe  dorsal  summit  uf  the  preoenlral  convolutiuoi, 
t»,  like  »th«r  K^ay  matter,  coni)ir«e<l  of  nerve-cells,  and  uf  nerve  fibre*  and 
flbrilt  supjHirtci]  by  neuroglia.  Tbe  nerve-cells,  at  leasi  the  oonspicuous  and 
«a*ily  rtco^lxed  nervo-ceiU,  are  scattered,  and  appear,  in  aectiona,  to  be 
tmbwided  in,  and  scjiaraled  fWrni  each  other  by  a  not  inconaiderable  but 
variflbW  iiuantity  of  somewhat  peculiar  ground  suWtauce,  not  unlike  thnc 
which  furiiio  «n  large  a  jiart  of  llic  moleciilar  layer  of  the  rereliellum.  Part 
of  this  ground  «nb>ilnnce,  which  n|){iart.-cilly  i<  nut  confined  to  any  particular 
layer.  1x1  (  xtrftcli'w  thrnngluHit  tne  tbiekncn  of  tbe  ciriex  U  undou)>tcdly 
neuroglial  in  nature,  hut  jiRri.  and  probably  th«  gn^tto*  p^rt,  i«  nervous  in 
nature:  it  is  largely  c<ini|><F»cd  »f  fine  fibril*  lmTen>ing  it  in  variouM  dirtw* 
tioRs,  the  transvcr«e  socliona  of  thtvc  libnU  giving  it  a  characteristic  dotted 
or  "  molecular"  apiK-nnince  :  nnd  thtt  majority  of  these  line  librils  arc  prob- 
ably the  continuations  of  braiiching  nerv»ceJle  or  dividing  nerve  librce,  the 
remoiwler  being  neuroglial  fibrils.  In  this  Ttamct  it  resembles  the  moleo 
nlnr  layer  of  the  cerebellum,  but  it  is,  to  a  inuon  gmter  extent  than  is  that 
layer,  tnivcned  by  niediiltutcd  nerve  fibres,  especially  by  tine  medullated 
flbree  tike  Iboec  seen  in  the  gray  matter  of  tbe  sjMnnl  cord,  £  o64. 

The  nerve-celts  iiubeddcd  in  this  ground  substance  is  more  or  leas  distinct 
layers  are  of  varioas  kin<U.  Tbe  most  conspicuous,  abundant,  and  character* 
istic  nerve-cells  found  in  tbe  cortex  of  all  regions  of  the  cerel>eUuni.  are  tliose 
wbieh  from  their  shape  are  called  pymmi't'U  ceti*.  These  vary  very  nmcb  in 
•iiM  and  have  been  distinguished  as  "  small  pyramidal "  cells  averaging  12  ^ 
in  lentrlh  by  8  r>  in  breailth,  and  "  large  pyramidal "  cells,  sometimes  called 
"  ganglionic  cclb,"  of  whieb  (be  medium  sixe  is  about  40  ii  in  length  by  20  m 
io  breadth.  Some  of  the  latter,  ucciirring  in  s)>ecial  regions  are  or  very  larjfe 
rise,  120  III  by  50  *>  and  have  been  called  "eiAnt  cellii.' 

Tbo  features  of  a  "targe  pyramidal  "  cell  are  very  characteristic.  Such  a 
t*\\  nnpeara  in  a  wet!  jin-'imml  vertical  section  of  tli«  cortex  as  an  clongatod 
niiMN-liii  trianglu  plaeeil  vertically,  niih  tbu  Ivasi-  looking  toward  tlM  under- 
lying white  tubiluncv  and  tlie  ta|ieriiig  a|ies  |H)inting  to  thi^  Mfliica^  Tbe 
cell  subataace  b  finely  gnnutated  or  filiriltaiol.  lh<;  fiTirilb-  nwecping  round 
in  various  dirfCtioiu ;  it  not  unfreuuentlv  c^nlainn  pigmrnt.  In  the  midiit  of 
this  cell  siibntann-  rattier  near  the  nose  Ik»  h  large,  cli-ar,  conspicuotu  round 
or  oval  nucl«ilatr<l  nucleus.  ,\i  ibig  base  thr  veil  iiulwtaAC*  ia  prolonged 
into  n  number  uf  proccsM^  One  of  tb(.-ae.  g«nenil)v  ulnrting  from  about  tho 
middle  uf  the  base,  runs  for  somo  distance  without  dividing,  and  soon  aequir- 


804 


TUB    BRA1.V. 


ing  a  roedulln  may  b«  recngniud  »  an  axis-cylinder  prooew;  tba  fibrp  lo 
uliich  it  |iv«s  origin  sneepA  with  a  moir  or  I«m  curved  onuree  into  Uw hI>- 
jm-eiit  white  matter.  In  suiue  instancee  the  axu-cylimlcr  prooen,  bj  a 
'T-(livi»iuD  like  that  eecii  in  a  ganglion  of  a  pDet(>rior  root  (^  97),  givwriK 
lo  two  fibres,  one  of  which  may  take  a  horizontal  ilirodion  ;  in  sotoe  renoiu 
of  the  cortex,  the  o(.-ei[>ital  for  inAiance.  tho  axbcytinder  prncea  baaiilla 
give  rise  hr  divisiuii  to  eeveral  librfs.  The  other  praoeeBee  from  the  bat, 
njiecially  inow  from  the  angles  <>f  the  triangle,  rapidly  branch  tab)  flat 
libril*  which  are  soon  lost  lo  view  in  the  |i;raund  Nibstance.  TheaoexW 
tlic  triangle  in  also  prolonged  into  a  procem,  which,  Kiviox  olT  fine  latonl 
branc-he>,  nnilce^.  as  it  were,  strait{ht  for  the  surfaoe.  bul  ultimately  bniteb- 
ing  into  fine  lltirilti  la  lost  lo  view  at  aooie  distance  from  the  body  of  the  ail 
The  cell  lit-*  ii)  a  cavity  of  the  (;r<vund  aubiiluDoe,  which  it  appears  nomallT 
Id  fill,  hilt  from  the  wallH  of  which  it  sometimes  shrinks,  developing  l>etiien 
ilMlf  and  the  wall  nf  the  cavity  a  «)»cc  which  mxy  contain  not  only  Irmpb. 
bnl  occmiioiiaHy  Irucocytce.  In  prcjiareil  apeciinens  the  reiracliun  vitliin  lO 
cavity  of  tli«  artificially  shrunken  ctlll  may  be  oflen  observed. 

The  "small  pyramidal  "  cells  have  much  the  same  features ;  that  (■  to  ist, 
tlic  cells  are  characterized  bv  their  pyramidal  form,  though  this  U  milunlljt 
not  to  ilif'linrl,  by  their  vertical  piMilion,  and  by  tlic  pnwmion  of  braDoUlf 
proccfBCf  which  are  hot  in  the  molecular  f^round  «ub«lancc;  (h«  ptfWDcc, 
flowever,  of  n  midluiMLl  axi-i  cylinder  pn>i.>M  has  not  b(«n  clearly  ilomoS' 
et  rated. 

Other  ncrvo-cclls  arc  moro  like  tho  orrlinary  nerve-cells  of  the  apliial  »nl 
and  of  the  inlcronl  wnihral  grav  matter;  they  ar*-  branched  cells,  of  im^- 
tar,  not  of  pyramidul,  form,  and  for  the  mo»t  jinrt  itmnll,  1H>'  by  IOf>.  Tbct 
ntftj  be  dujacterixcd  by  Ihv  relative  Inrgo  sine  (T  n)  of  tbo  micleua,  aarf  w 
not  po8MM  an  axis-cylinder  process ;  at  least,  »ich  n  praCMi  bas  tkot  fet  bto 
demonstrated.     They  are  fmiDently  spoken  of  as  "  angtilar  "  cells. 

Another  kind  of  cell,  the  "  liinfoTTD  cell."  which  is  found  tu  all  n^omt^ 
the  oonex,  has  a  eharscieristic  spiDdle-ehape,  the  cell  substance  being  |>r»- 
Iniiged  at  the  oprioeite  |Kiles  into  tapering,  ulliniately  bmncbed  pfoeeso. 
The  long  axis  of  tlie  cell  is  generally  placed  horizouially,  following  the  cut- 
vuturo  of  the  cortex,  and  being  thus  at  the  sides  of  the  sulci  vertical  Ui  Ibt 
surface  of  the  brain ;  it  is,  however,  at  linws  inclined  at  vuriotia  angles. 

filill  another  kind  of  cell,  the  "granule  cell,"  or  "  nuclear  cell,"  isowis 
which  ihc  nucleus  is  siirmunded  by  a  relatively  small  ouanlily  of  cell  nib- 
BUuioa.  9  !•  hy  7  ^,  more  or  Imb  spherical  in  form  in  ordinary  prenatatioDi. 
bat  probably  breaking  tin  into  delicate  branched  procaaea.  Cells  of  ihii 
kind  are  sparsely  scaticnil  throughout  the  cortex  generally,  but  in  particuhir 
rvjiioiif^r.  y.,  the  ncctpital — are  cniwiletl  together  into  a  layer,  which  ia 
many  rcKpccIs  rovmbl(«  the  nuclear  layer  ul  the  cenbcilum,  and  hsN  licea 
calkVl  the  "granular"  or"nuchjar"  layer. 

Lastly,  ihrou^diout  the  cortex  are  found,  bcddde*  indulHtable  iMmr*«sili 
ami  indubitable  neiirriglini  C4-lti>,  numerous  small,  aomowbai  irregular  cclk 
conceniing  which  it  may  l»e  dchntc<l  irhelher  they  are  really  ncrvota  q» 
simply  neuroglial  in  nature.  Moreover,  in  umag  tlie  name*  given  above  for 
tite  various  kimU  of  ncn'ccclls,  it  must  be  rvmemborcd  that  many  tninri- 
tional  forms  an  observed ;  collf.  tor  instaoco.  may  be  seen  interniediatt)  in 
form  between  pyramidal  cells  and  "fusiform"  or  "angular"  cells. 

The  medullsied  nerve  lihm  which  take  part  in  the  cortex  may  be  coti- 
eideivd  provisionally  a»  forming  two  calegorica.  In  the  finti  place,  fibres 
SKcep  up  vertically  into  the  cortex  from  the  subjacent  "central  white 
mnttcr,"  taking  at  fim  a  curved  roune  as  they  enter  into  the  gray  matter. 
and  then  ap|)earii}g  to  run  straight  toward  the  surface.    These  are  armngctl 


AOUE    HISTOLOGICAL    FKATUBES    OF   THK    BRAI>*.        805 


the  dcep^  levels  in  iMiDdlfv.  leavinj;  verti<.'n1  columna  of  tlie  |>nir  miitler 
belwcou  iDCtn  ;  but  at  more  Eiijierra-iul  k>vela  ihe  biin<lleB  s|iren<l  out  aud  ura 
cniiliiKDy  loM  to  view.  Uraidee  (hue  dixtiiict  veitical  fibrea  uid  buodla  ot 
nbm,  »f  tlie  ordinar;-  roeduDnted  kiod,  which  we  have  reason  to  think  an 
Ui*«ads(or  bef;inniiij^)  on  I  he  ooe  band  of  fibres  of  the  pedal  and  teKuieiilul 
•yaMmai  and  on  ih«  uiher  huud  of  Bbna  of  the  corpus  calhwiiin.  or  the  otbci^ 
comtniawrftl  fibrea  spoken  of  as  "asocial  ion"  fibres  t^  GW).  an  exveedingljr 
\nTgf  number  of  fibres  uf  the  peculiar  fine  iiii.-iliilhuod  kind  run  in  Tarious 
dircctiona,  forming  a  di-ti««  network  iu  the  jiriiuud  substance  of  the  gray 
tnaiicr  between  llie  celU.  Wo  itiuy  add  tlial  tItU  svuem  uf  fine  medullated 
fibres  »  of  late  growth,  iind  is  not  l\i]lv  developed  xa  ninu  until  tiro  or  three 
jreare  after  birlh.     Many  nf  tho  wedullaled  fibns,  coarse  as  well  as  fine,  Inko 

•  horiionial  dii«ction  porullel  to  the  surface,  and  in  certain  regioin  are 
sfiecially  developed  into  a  la^r  or  into  two  laj^en  so  n  to  fonn  a  horizontal 
•treak  or  Mreuka. 

The  vaicular  pia  mater  in\-rets  clnwlv,  mu  «i>  have  xnid,  the  whole  tiirfnoA 
of  the  cortex,  dipping  down  into  ihr  *ulci :  nnd  fmni  it,  iw  i»  thocitMof  the 
spinal  cord,  [irnirwn  carryhig  IiIoimIvc-'Wi'Ih  nnd  hi-jiriug  lymph-^MOM  pan 
inward  to  supply  tlic  gray  matii^r  with  bUxul.  Rut  whilr,  as  wo  sfaall  ••• 
later  on,  the  nupply  of  oloodvcMcIs  to  the  grny  matter  is  considcrmble,  lh« 
Iruljr  connL-ciivoiixHue  elemmta  of  the  »in  miiier  proccmta  are  soon  momd 
inio  tteunjg'ia.  ImmrdiatHr  )>rni.-«th  the  j>ia  miUvr  farming  ihu  Immedtiite 
MlHkeo  of  thp  cortex  io  n  thm  layer  oimsting  of  neuroglia  only. 

§  651.  Tile  nervp-«II»  "f  ihi-  above  several  kinds  arc  nmiiigiil  more  or 
IcH  distinctly  iu  Inycn  piirRlkl  lo  the  surface,  so  that  the  whnk-  iliickncwof 
tlM  eoiUx  may  b;  meom  of  thoni  be,  more  or  Ivs  succ«Mfullr.  dividt-d  into 

•  MliSB  of  lones,  one  above  the  other ;  and  we  may,  ns  we  have  uiid,  recog- 
niu  on  the  one  hand  a  general  arrangement  common  to  the  whole  surface, 
and  on  the  other  hand  uiodificatioos  existing  in  the  several  regions.  The 
geoeral  arnuigenMUt  mair  be  said  to  be  one  of  five  layers  or  xones,  untally 
CDUnted  from  ilie  surface  inward. 

The  fiAb  layer,  lying  next  to  iIm  "eniral  white  matter,  fairly  uoiforni  in 
dwracters  and  thickness  (ahuut  I  mm.)  over  the  greater  pun  nf  the  brain, 
is  characteHied  by  the  presence  of  sotucwhnt  sparselr  scattered  "  futiform  " 
eelli),  though  other  branclted  cells  arc  pn^tenL  It  is  broken  uu  into  vertli-al 
c<>luinns  by  the  bundles  of  vcrlinil  fibrui,  luid  tU  dciuaroatioo  from  the  whltu 
matter  helon  i*  somewhat  iudistiucl  owing  to  the  fact  that  in  live  hrnin  tlte 
while  mntli-r,  uS[H:('iaUy  tlinl  lying  hnnc-ath  the  cortex,  cuatuim  celU  and 
small  gr<iu|«  of  cells  Iring  betwocn  the  bundl>«  of  librva  to  a  much  greater 
extent  ih4H  does  ibe  wnite  matter  of  the  spinal  cord. 

The  fourth  layer,  lying  above  the  proccding,  varies  much  more  both  iu 
thickness  (O.i-'t  mm.  to  O.l.'i  mm.)  nti^l  in  its  charncterSL  The  constituent 
cells  ore  on  the  on«  hand  large  pvrnmidul  ctrlU,  and  on  iIh;  othrr  ham] 
"granule"  or  "nncle-ar"  cells.  In  wnie  rvgi^U"  it  may  Ito  subiiividvil  into 
two  layen.  Ibe  small  "  nuclear"  colls  being  oo  abniidani  as  to  fumi  in  tlic 
Uf^r  iwrt  of  the  layer  aiepiirate  layer  called  the  "granule"  or  "nuclear" 
layer.  This  fourth  layer,  like  Ibe  prcooliiig  fitlh  layer  beneath  it,  t*  split 
Hpintii  vertical  column*  by  tbo  bundles  of  vertical  fibres,  but  to  a  lestdsgrwo. 
It  is  marked  in  its  lower  pnri  by  n  horiioutal  streak  due  to  numerous,  mostly 
fine,  niedullatcd  fibres  running  huriionlally.  hi  the  oufiex  of  iha  bland  of 
Kiel  this  horiioutal  layer  la  developed  into  a  conspicuous  shaat of  nwdullated 
fibres,  eeparatiiii*  the  fourth  and  fifth  layeifi  by  a  distinct  interval  of  obvious 
while  matter,  i'his  tifth  laver  of  ftisiforni  celli.  thus  detached  from  the  rest 
of  the  cortex,  is  whiU  i«  called  the  el'iiutrum  (Klgs.  193,  im,  e/.). 

In  the  third  layer,  the  ooujttitueut  oelb  are  the  characteristic  pyramidal 


806 


cells.  These  nre  for  tlir  mimt  pnrl  litr^c,  tlioiigh  (liminnhintr  in  mu  fW>in 
below  upwarti.  ami  ihc  layer  hns  l»wn  cnlUtl  (Ik-  "  layi-r  i>f  UtJt;  pynniiiUI 
oellK,"  tl)iHi);h  ill  certain  regions  the  Inr^gcnt  [lyramidiil  oelll.  Aiiil  noulilv  llw 
{(iant-cclls  are  luiinil  in  (tie  pnnM-ding,  luiirlti,  Uvcr.  Tlie  celU  «nr,  oii  ilw 
wbole,  scatlcreil  Bomewhnt  sptirffiljr,  though  frvijiietilty  gnthervd  inlii  mail 
ETuups,  and  among  them  oeair  small  "nuclear"  and  other  iiulU.  Tbr 
buodltfl  of  vertical  fibres  tprcad  out  rapidly  in  litis  layer,  so  tliftt  lin- 
ealumnar  arrangement  becomes  lost,  and  many  of  the  Rbm  undnublully 
become  axis-cyliniJcr  proceBsoa  of  lh«  pyramidal  cells.  Though  tlra  Ujw 
Tories  in  thickness  (1  mm.  to  0.4  ram.),  and  in  some  of  ils  features  in  diffeniA 
tenatti,  llie  characlerialic  pvramtdal  cells  are  present  over  the  whole  surfoA 
oftlK'  bemisptiere.  In  Llie  lower  part  uf  the  layer  a  second  horiuintal  dreftk 
ol'cliisely  iDterwoveQ  bori^onlal  flhres  fretgueiitly  makeii  iu  appearance. 

The  second  layer,  geneniUy  a  thin  one.  though  varvius  from  O.i'i  mm.  |« 
0.T&  mm.  ill  tliickneM,  is  alai>  funned  hy  pyramidal  cells,  but  ii^distingul'lieJ 
from  ihe  layer  b«li)w  l>y  the  nb>euce  of  lurgt  nuil  medium-sued  cells  and  Uf 
lh«  proieiiee  of  ouiiit-Miiti  amall  cvUf  dosirly  packed  lu^tlier;  it  has  ben 
cnll«<i  "the  lavcr  i>f  *mnll  pyramiflal  celU"    As  we  have  said,  tlteee  unaUer 

Iiyramidal  c.a\\i  dilfer  niitii-what  fr<ini  llie  larger  cells ;  and  the  oella  in  tin 
ayer  art  souieiimai  dwcrilii-il  on  "  ituj^ular." 

The  lin^t  ami  miwt  «ii[)t-rti(-iul  layer  is  cbaractoritMl  by  tlie  predominance 
nf  tliv  molecular  ground  MihiUincc,  l.Iie  i.-clU  being  j'cw.  lur  between,  naall, 
ami  irrt'icular.  The  ground  wilxitantH!  itself  Mccmn  to  W  more  largely  tte«- 
roglini  in  nHlnrc  than  in  ihc  other  layer*,  and,  us  i*C  Aaid  above,  its  extrviu 
•urface  ap|MMtr«  to  Ix-  fiimi»he»l  hy  iiuiinigtia  ali>iic.  The  layer  m  gmeraliy 
spoken  of  as  the  "  peripheral "  or  "  sujHTliml  layer,"  or  sontclimiaia*  ik« 
"  molecular  "  layer.  The  tapering  reriical  proccsMs  of  the  pyramidal  eel!» 
iBfty  be  traced  into  this  layer,  which  indeed  varies  in  thicknesa  according  lu 
the  abundance  of  pyrntuidal  cells  in  ihe  subjacent  layers;  numeroos  euBtr- 
vhat  line  medullatcd  fibres  also  traverse  it  in  a  horiiontal  direction. 

^  652.  The  general  arrangement  just  described  varicH,  a»  we  luiee  aaMl.  in 
diirereiil  regions  ul'  the  cerebral  surface.  We  must  content  ouraelree  hut 
with  pudnting  out  the  eharaoteriHtieg  of  two  or  three  important  regions. 

The  regiuu  which  we  hnve  (^  O^l.'Ij  cidled  the  "  motor  area  "  or  "  rc^iaB," 
I*  t-hnrncteriud  on  the  one  hiiml  by  the  grenl  thickocae  (1  mm.)  of  the  thin) 
Inver,  that  of  lar^  pyramidal  cells,  as  well  us  by  tlte  number  and  siee  of  the 
cAU  containeil  in  it,  nnil  on  the  other  hand,  and  iwpei^iallv,  by  the  promi- 
nence in  the  lonrlh  lavcr  of  remarkable  cliinter^  or  ver)-  large  pyramidal 
celN,  of  the  kind  which  are  n^fnrred  to  nlmre  <.S  G'^Oi  as  being  IKfjuently 
called  "gangliunic  :"  it  i»  in  tlii«  rvgion  that  "giant  celU"  are  lixittd  in  tlit 
fourth  layer,  namely,  in  the  upjicr  part  of  the  precentral  and  at  t)K  summit 
of  the  (toetcontml  convolution,  an<t  in  the  immreutral  lobuU,  aix(uini>g  tlidr 
gnmlCEt  tsite  at  the  top  of  the  preconlml  cunvolnliuiL. 

The  occipital  region  is  chonivteriwd  hy  the  prominence  of  the  "  Bmnula" 
or  "nuolear"  cells.  These  not  only  form  a  disiincl  division  of  tbn  fourtb 
layer,  but  are  also  conspicuous  in  other  layers,  their  amngeroent  being  surh 
that  some  authors  have  been  led  to  divide  the  cortex  of  tbu  region  iittu  seven 
or  even  eiglit  layert).  In  the  present  state  uf  our  knowledgo  ire  may  be  con- 
tent with  inaijLing  that  the  great  mark  of  this  occipital  ra^on  is  tna  abun- 
dance nf  tbese  small  "nuclear"  cells,  together  with  other  ^mall  "nngiilar" 
cells,  irheivby  the  pyramidal  cells  seem  to  be  mode  l«n  coti«piciioUK.  Il  is 
worthy  'if  notice,  however,  thai  in  the  third,  but  more  especially  in  the 
fourth  layer,  a  few  cells  of  verv  large  siie  are  met  nith,  which  hy  their 
largo  branched  cell  subtttauce  atid  eontiptctious  axis-cylinder  prooeas  rceemble 
tbo  \»rge  cells  in  the  motor  region  ;  but  it  should  be  noted  thai  vbile  ll»eae 


flOMK    HISTOLOGICAL    rEATURES   OF   THE    BBAIN.        S07 

iatfit  orlU  occtir  (at  Irast  in  idbii  and  in  tliP  i»on)»!y,  though  not  in  goate 
of  ikf  lover  aiiimalH,  as  llie  ralibit)  in  rrry  iJHinito  cluMrre  in  the  motor 
n^on,  ilicy  occur  Niiglv  in  lh«  occipiliil  nxton.  |p  Uua  occipital  rc^oa 
tbr  layer  of  liorifrinuil  ^brcs  ia  the  Tourth  layvr  is  verr  COiupicuouf,  and 
owIdc  to  (h«  number  of  ordinary  medullaled  ohm  prpsent.  foriua  a  white 
alf«aK  vwhie  even  to  tbo  nalc«d  eye. 

Ill  tbi-  fr-inlal  rC|;ioii.  in  front  ul'  lhi>  motor  region,  the  arrftni^eiuent  is 
more  in  ac4'ordiuioe  with  whiil  we  have  described  &«  the  ;;enerui  jilun,  The 
two  prminidal  layen  are  we'l  marked,  as  ia  alao  the  fuurth  layer ;  but  the 
layer  of  larf^  pyramidal  cells  ia  much  thinner  titan  in  the  motor  re^'inu,  u 
is  aJao,  though  to  a  lew  extent,  the  fuurth  layer,  while  the  tif\h  layer,  that  of 
fusUbnn  oell«,  ia  thicker  than  elsewhere,  i^mall "  nuclear  "  celU  arc  perhu|ia 
more  abuu(lau(  in  tliia  region  throughout  all  layers  than  in  the  motor  region, 
but  are  for  leo  oouspicuous  than  in  the  occipital  region. 

We  may  here  remark  that  the  transition  iu  structure  from  one  region  to 
anniher  u  very  gradual,  doI  tihurp  and  dtdlinel,  and  i^  perhaja  e^pucialty 
Knidual  in  pwuing  from  the  motor  i«Kion  backward  to  the  occipital  refciou. 
It  ia  not  uowible  to  recogoiie  bistologioally  the  limit,  for  iustauc«,  of  the 
tmitor  repon  na  determined  ex  pari  men  tally. 

Id  sneuial  iwion*  of  the  bniin,  for  inntaui'e  in  the  olfactory  bulb,  of  which 
m  shall  nicak  later  on,  very  great  nioilirnutii.iu.''  of  tht;  ^ncral  jilan  may  bo 
obMTved  n  tbo  cortex.  We  eaiinol  onl«r  unon  thcM«.  but  may  juKl  refi?r  lo 
Um  ooraa  aminoDis  or  hippocampus.  At  tnc  ventral  end  of  the  temp'>rul 
loba  ttw  cyrus  bippocamiii,  the  structure  of  whose  vurl«x  follows  tbo  gvnoral 
plan,  b  Utrust  inward  so  as  to  project  into  the  eavity  of  tho  dcsoeoding  horn 
of  llw  lataral  vetilricle,  forminir  iIm  ridge-like  proininence  known  hi-  the 
ahoi*  oamc  Tbe  substance  of  lh«  oorau  ammoDis  is  therefore  corticnl  sub- 
ttmuot  eoverwl  od  the  side  of  tbo  ventricle  by  a  thin  prol»nj^tion  of  the 
eentml  whito  matter,  which  is  in  turn  covered  by  the  ependyma  lining  the 
ventricle,  A  vertical  Kcliou  of  this  substance  ehows  that  while  tlie  fifth 
and  fourth  layers  are  reduced  lo  xmall  dimeuaioiis,  the  third  layer,  that  of 
large  pyramidal  oella,  is  well  developed,  though  narrow.  The  cells  are  large 
and  rumarkalily  lon^,  and  tlie  tapering  procewn  are  arranged  so  reijularly 
aa  to  give  rt>«.  t-«pecially  in  siaiueil  preparations,  to  a  marked  radiate  appear- 
aiHieL  At  tho  level  of  thv  aeeund  layer  there  uccun  a  large  deTelopment  of 
capillary  bloudvesMhi  and  a  seareenuM  of  cells,  giving  rise  to  a  "lacuDar" 
■ppearaDoe;  and  tho  Tirwt  or  mulocular  layer  is  uf  some  couiiderahle  (hiok- 
una.  From  tlw  promiuence  of  tlie  pyramidal  cell&  in  tbL-  region,  tlie  third 
layrr  in  the  gVDcrml  plan  of  the  cortex  has  sometimes  been  iipukeu  of  u  the 
"  iiirniiitiim  of  tbe  coniu  aininoni*." 

(663.  In  the  present  state  uf  knowledge  it  is  im|Hituihli^  to  oomt"  to  any 
Httsfiutory  conclusion  conceniing  the  meaning  of  thi-  variety  aod  arrange* 
moiit  of  the  celUnnd  olhrr  comtitiient*  of  iho  curtpx.  The  celln  nith  Ihrir 
braacbee,  the  ncr\-o  tibres  and  tho  nerve  tibrils  form  a  network  of  gray 
matter  which  ne  may  oompar*  with  thir  gray  matter  of  the  s]>inal  cord 
(6  MO),  but  which  is  obviously,  as  we  might  exiHict,  far  more  complex  tlinn 
liiat  il.  We  mav  conclude,  and  experimi-mtal  olm-r^-niion  confirms  the  ooa- 
cJuaioo,  tbal  the  large  pyramidal  cells  with  rpcognirahlc  axi:M:ylindcr  pro- 
oaana  serve  as  trophic  centres  for  the  Kbrcs  which  appear  to  start  from  them. 
And  vre  may,  though  with  less  confidence,  explain  the  large  siu  of  thoeo 
cells  in  the  motor  region,  by  the  fact  that  thcv  ^irc  nno  to  fibres  of  tbe 
px-rainiilal  tract  stretching  a  long  way  from  their  ori^n  in  the  call,  and 
ibcrcl'ore  demanding  great  nutritive  activity  on  the  part  of  the  cell.  W« 
may  perhaps  also  ooncla<le  that  these  fibres  are  olferent,  motor  fibres,  dea- 
liued  to  cmrry  impulaea  from  the  curies  u>  the  peripheral,  or  at  leuit  distant 


80&  TFIE    BRAIX. 

pnrts.  AimI  ir«  may  fitnher.  with  bonover  ilUtinotty  !>'«  confitlviict.MHM 
tlinl  l)i«  n/x  of  tl>e  ci'll  iit  ctirn-lateil  t"  (lie  tm-r^T  nliirb  haa  to  bo  toiBaHU 
in  llif  ilii>cliiirgu  nl'  t-ilVmil.  iimtor  im[tui»c:).  ll'  wi-  nc(i'p(  i)h««  cooaarinni 
wc  muxt  nlw)  Iwjir  in  mind  llimt  mich  ii:ll:i,  irilli  nxin-c^'liuiliT  iirocaHBooi- 
linnecl  on  nii  filirii>,  tirv  iint  liinilc^d  tii,  tliougli  most  ■)Hin<liint  in  tbtt  moUt 
ngion,  hut  nrc  fuunH  in  nil  regions  of  Umi  cnrivs ;  uid  wv  muat  litnc*  cm* 
elude  Uiit  iinpulMS,  which  vre  mtiat  vnll  pRi^rrDt,  proceed  from  oil  pan*  iif 
tho  cArtex. 

Il  M  ohviouf,  howcrrr,  thnt  the  conncctioD  of  the  conical  networit  of  gn^ 
matter  with  lh«  fihrt-s  of  iho  whitv  mntlor  is  <!Abclcd  in  mrt  only,  muI  iMt 
n  fRiall  (inrt,  hr  thr  mpthrK]  nf  axis-i-ylindcr  |irace««M  definitelr  pnilniiiKd 
from  tlip  cell  »iiWimcc  of  cclU.  A  pnrt,  nnd  probably  a  greater  pari  uf  Un 
fibree  sweeping  up  from  thp  subjacent  whil«  tiinUer,  vhcihcr  they  be  fibiv 
of  the  pednl  iind  Icgmciitnl  »y»toDiE  or  c-iilloeal  or  "aMocialion  "  fibres,  col 
io  the  gray  matter  in  eome  other  war  than  bv  bodily  bein^  continue  ip  lli 
cell  BiilMtance  of  cells;  they  plunge  into  ai)d  brenli  op  witliia  the  network, 
of  which  fibriU  no  less  than  ccIIb  lonn  a  conspicuous  jtart :  and  we  may  hai 
rejieat  the  remark  which  we  made  in  speaking  of  the  cerebellum  coocerauj 
llie  uctual  continuity  of  the  element*  of  the  network.  Moreover.  bcMte 
the  vertical  fihrei  obviously  coming  from  the  subjacent  while  matter,  we 
have  io  this  gray  mailer  to  deal  with  the  lihfes  of  homotiisl  nitd  otber 
dirc<-lt'>u»,  which  may  come  from  while  nuiUer  not  far  <tff,  hut  which  nmr 
coniv  from  some  Dei|;hl)oring  ^ray  matter;  our  praaent  kDoirleclge  will  M 
enable  ua  to  settle  this  |>oinL 

In  the  spinal  cord  we  were  able  to  divide  all  the  fibres  tnlo  affi>tcut  at»d 
cfferrnt  reiipeotively ;  though  even  here  we  met  wttJi  some  difficulty.  ))nl- 
ing  with  the  cerebral  cortex,  which,  a>  we  have  already  aeon,  is  rrnniidjr 
espeaally  conccrneil  tii  voluntary  moTcineiil«  and  in  ibe  dcTclopnieDt  of  (ull 
eensaticnE.  we  mar  he  teniptctl  to  con*idrr  the  fibres  connected  with  lb*  ptj 
matter  as  similarly  ilivisiblc  int^)  motor  and  urn^ory  ;  and  no  may  go  on  IS 
suppose  thnt  the  tihrn  joining  (he  cnrlcx  a*  axis-cylinder  processes  of  ntag- 
niiahle  cells  are  moiur  lilircs.  ntid  ihnl  all  the  other  fibres  joining  (be  ffij 
matter  in  some  other  wiiy  are  sensory  tihn?s.  But  io  doing  so  we  are  goio^ 
beyiiml  our  lether ;  in  all  prohahiliiy  thp  nervous  proecsSM  fpHtij!  on  in  tbs 
cortex  are  far  too  complex  to  permit  such  a  simple  claasifioalion  of  the  fatw- 
liuna  of  fibres  as  that  mto  motor  and  sensory;  and  any  atteoifH  lo  arnuin 
either  fibres  or  regions  of  the  cortex  as  simply  motor  or  sensory  h  iirohahly 
misleading.  But  we  shall  have  to  return  to  these  nuitteis  when  we  deal  viu 
the  functions  of  the  cortex. 


Ok  VoLCJiTARY  MorRURHTs. 


r  i»ov»    I 
.  of  tW    I 


$664.  When  we  examine  ourselvea  wc  rccngnixc  certain  of  our 
roenta  aa  "voluntary;"  we  say  that  wc  carry  thcro  out  by  an  cflbrt 
"  wilt."  And  when  wc  nitn<«s  the  rocivcmenlR  of  other  people  or  of  animab 
we  regard  as  also  voluntnry  xuch  of  those  moxpmeniK  as  by  their  characters 
and  by  the  circumstaiii'cs  of  their  occurrence  ecom  to  be  carried  out  in  the 
same  way  as  our  own  voluntary  movemoDts.  Kven  in  tho  caw  of  some  of 
our  own  movement]^  we  are  not  always  clear  whether  they  are  m]ly  Tolun- 
tary  or  no;  end  in  the  case  of  other  people  and  of  animals  it  is  atill  inore 
diliicult  to  decide  the  question.  It  would  be  out  of  place  to  attempt  to  dis> 
ciiiv  here  how  vulunlary  moreoienta  really  differ  from  involuntary  niov» 
mcntF,  or,  in  other  wonls.  what  is  the  nature  of  the  will ;  we  muat  be  muimt 
to  lake  a  somewhat  rough  use  of  the  words  "  voluntary,"  '*  voHiioiuil,"  and 


609 


"  will  "  M  «  Intuit  for  phyii"logiritl  HiscuBRion.  Wc  may.  however,  remark 
lliat  iia  fur  v  llir  muftcuUr  side  of  the  act.  iT  »i>  may  »*>'  *\ii;h  an  vx|)red«ioa, 
ia  concerned,  a  roluntary  movement  dues  not  dilfi-r  in  kind  front  an  involun* 
laiy  nioventont.  It  i*  perfectly  tnie  that  a  fkilled  mnn  may  by  pmetice 
Icam  In  exonito  miiKiiliir  manceuvrce  which  he  irnuld  not  have  Ininit  ta 
txtvvie  hud  not  nn  intelli)^Dt  volition  bcco  operative  within  him;  hut  our 
awn  eX|)«rienoec  teaches  ua  that  many  more  or  lea  intricate  movenipnl* 
which  have  nndoubtetlly  been  leaml  by  help  of  the  will  may  be  carrioil  out 
under  ctrcuntstancee  of  such  a  IcimI  ihnl  we  feel  comiielled  to  refE'i'*!  thom 
U,  at  ihe  time,  involuntary ;  ami  it  may  at  leuat  he  debated  whether  rvcry 
iDoveiDeiit  which  we  can  carry  "Ul  by  an  efliiri  of  the  will  may  not  nppcar 
«nd«r  appropriate  circumatancai  ii*  part  of  an  iovoluDtary  act.  In  the  «ue 
of  the  lower  aniroalB.  in  the  fm^  deprived  of  its  cerebral  hemispherM,  for 
itMaDee.  we  have  Hceti  that  viiluntary  diffrr  from  involuntary  mivomonte. 
not  bj  their  eMuiitial  iiuliirr,  hitt  by  iho  rvlation  which  their  occurrence 
bouv  to  clreumtilnnceH.  We  have  lher*'fiiri'  to  m-ek  for  the  distinction 
between  voluntjiry  and  involuntary,  iii>t  in  Ihr  cim Ordination  of  the  miucular 
Ktid  iiervouti  com[iiinenU  of  a  movcmciil,  but  ia  the  nature  of  the  procMS 
which  *tart«  the  whole  act. 

The  ht*toriai,  related  in  a  preootlins  section,  of  variouH  animals  di-prived 
of  their  cerebral  hemiiphcnr,  while  they  have  further  *hciwii  tli<!  dilfii'ully  of 
ilniwini,'  a  «hnrn  lint'  lietwc'ii  tlio  pmenoc  and  aliwiicc  of  volition,  aucb  aa 
when  *c  apjmi)  m  <nir  own  conticiousncM  we  room  able  to  draw,  have  tauf^ht 
a*  that  ill  a  broad  een»o  the  iirmrncc  of  volition  is,  in  the  hinhnr  vertebrata, 
^priulent  nn  tlie  pomewion  of  the  cerebral  hemiephen?«  ;  and  wo  have  now 
tn  inquire  what  we  know  oonceming  the  way  in  which  the  cerebral  cortex, 
(or  tbi>,  a«  we  have  wen,  is  the  important  part  of  the  cerebral  hemiitphero, 
by  the  help  of  other  pana  of  the  ner\-ou3  syxtem  carries  out  a  vuluntary 
movemcnt. 

$  6U.  Wiib  this  view  we  inav  at  once  turn  to  the  reanlla  of  ex[>erimental 
Interference  with  the  cortex.  When  the  aurAice  of  the  brain  ia  laid  bare  by 
removal  of  tl»e  skull  and  dura  mater,  mechanical  atlmuhition  of  the  cortex 
pnxlucca  little  or  ii»  efted,  lhu>  afTortling  a  contrant  with  the  nwulia  of 
nievhanii-ally  alimulatin^  other  portion*  of  the  brain,  or  other  ner^'ous 
mmclurt-a.  And  for  a  long  time  the  cortex  war  upokvn  of  •«  InaeoMble  to 
Htitnulation.  When,  howt-ver,  the  eleclric  current  t*  einjtloycd,  either  the 
make  and  break  of  i1h*  constant  currmt  or  the  more  miinat;mhle  inlcrrupled 
current,  vtry  markiil  reiulii  follow,  II  is  found  that  certain  movementa 
follow  upon  eWtric  otimiilntion  of  certain  regions  or  areas.  The  rcsulta, 
inomiviT,  dilTer  in  dilTi-rcnl  animals.  It  will  be  convenient  to  begin  with  the 
dov.  on  irhich  animal  tht^  obtcrvaliow  of  this  kind  were  tint  oonductett. 

When  the  surface  of  the  dog's  brain  ia  viewed  from  the  dorml  surface  • 
short  hm  deep  soleu*  is  smn  toward  the  front,  running  outward  almost  al 
riebt  anzica  from  the  great  loDjptiidinal  lueure;  this  is  called  ihf  irueial 
aiwM  (Fig.  2<''2),  the  syras  or  convolution  in  front  and  behind  it.  and 
■weepinx  around  its  end  being  called  the  aiffmoid  gyrtu.  It  will  hardly  bo 
proJilable  to  discuss  here  cither  the  homology  of  tbia  sulcus  or  the  names  of 
iIh'  otl>er  sulci  and  convoltilioits  of  the  dog's  brain.  We  mention  thi<»  sulcus 
tiecause  it  is  founil  that  (^liinulaiion  of  the  cortex  in  a  region  which  luuy  lie 
broadly  d«scribeid  as  that  of  the  neighborhood  of  this  crucial  sulcus  givca 
riae  to  movements  of  varioui  parts  of  the  body,  whereas  no  sucli  noventeots 
result  from  stimulation  of  the  extreme  frontal  resioii  in  front  of  the  area 
around  the  crucial  sulcus,  or  from  siimuUtiou  of  the  occipital  rt^ion  behind 
this  area,    i'ertain  exceptions  may  be  ma«le  to  this  brood  ttoteraent,  but 


TOE   BRAIK. 

tlwse  it  will  bo  b«st  to  <li«cu«  la  reAtnnoo  to  tli«  more  highljr  <lfTtlii|iNl 
monktr. 

The  region  of  the  corl«x  in  the  iwighborbwtd  of  tb«  crucial  wIm*  dwjr 
theu  bo  t«rmrd  nil "  exdtablv  "  or  "  motor  "  ragion,  iiiadmach  u  ilimiililwa 
of  thi<i  roRion  leads  to  luovcmente  cnrriiMl  out  hjr  akelotal  muwin,  wbik 
etim Illation  of  other  re^i'ins  <loe*  not.  Further,  Klimulatioti  of  Mrttcnlar 
dislriciti  or  arvm  of  tlie  re;ii<in  leads  to  particulur  movvmeois  earned  out  bf 
partkular  musolte.  Fur  iuitiaDoe,  stiniiiUti«n  of  the  more  nwduD  parti  « 
tbe  errtifl  beliind  ihe  k-rucial  aulcus  ( l^xji.  'iO'J,  C)  l«mla  to  movenetitB  of  tha 
1iin<I-ttmb.  nhereaa  atimtilalton  of  tbe  lateral  part  or  oul«r  «nd  of  tba  tarn* 
gjixn  leads  to  inoT«neiit«  of  th«  fore-liiab,  aod  im  najr  h«t«  dtatia|[ilU 

no.  m 


^ 


Tiia  Arm  op  tbi  CuniiAL  Oa»voumM«  or  n>  Vwt.  teooann*  to  liirao  tin  tmnn. 

(1)  B.  Tbcuoitbi  iht  muMilaiof  ilMMck.  (31  A,Tlia  ana  ftir  Um  extenili«  »oi  aMBahaW 
Ih*  itaf*.limlv  fllK  nauwkvtktOmoaaailraMUaBaf  UwftnlUBii.  'liCTlHuaM  IM 
blMd-Unb.  Konnlaa  lnuin«fwl)r  Uwwd  *m»  tfunUam  I  *nd  3  Itma  bkihI  i  I*  ibm  ■Mav*" 
•aim*.  W  D,  Thir  bKtBl  UM. 

between  nn  areA  atimultilion  of  wbich  (Fig.  202.  E)  ImiU  to  flexi'>r, 
fore  limb,  and  an  area  (Fi^.  202.  A)  etimulntion  of  which  leads  tor^' 
of  tlte  saiae  liinl>.     lit  a  atoiilnr  way  stioiulalioD  of  ollMir  ureas  wi: 
"motor"  region  leadg  i»  muven»eaia of  this  kind  or  of  thiu  kind  of  ;i< 
of  tlw  ejet,  at  the  muulh,  of  oilier  p«rta  of  the  face,  of  the  tont;n(<.  *«''  "' 
on.    Obviougly  iit  tlic  <ii>g  this  ref[i<in  of  tlie  oorteix  hua  conn«cti<)tu  •iU 
tbe  skeletal  muscles  wliieh  ild  ni>t  ot>uin  betw«eea  other  re);ion«  of  thocnrtan 
and  thi«e  miMcloe;  and  rurih«r,  the  reunion  tn  questioo  ta  lopoi^itr^''^''' 
dillereiiiiutod.  ao  that  certain  area*  or  dislriets  of  tliu  re^ou  are - 
connected  with  certain  »kel<Ttal  niuiwlee  or  >,'r<>M)a  of  niu»clw.     U'^  >»•' 
■peak  of  ft  '*  lucHlt«uiii}ii  of  function  "  in  Ihid  rt-uion  as  oonipftred  with  nibfi 
regions  of  the  cortex,  and  in  tiie  aevenl  areas  within  the  rogioa  as  eomptn^ 
with  each  other. 

Tlte  muHoloa  which  arc  ihuN  thrown  into  oonlractiou  are  the  mutd*'' 
the  np|HMitv  side  of  tbo  body.  When  "  tlie  lure-liinb  areb,"  a»  we  niay  <all 
it,  of  the  riuhl  hemiepbcre  ia  elimulntnl,  it  in  (he  left  f»n>-limb  wbicb  i* 
Riovet) ;  iinif  so  with  the  otlier  arena ;  it  i>  only  in  exceptional  cum*,  tt  io 
certain  niovementa  of  tlie  eyti.  that  tbe  eflttd  is  bilateral :  m  Diov«iii«it  oxi* 
fiuni  to  the  aam«  aide  h  Uist  •Umulateil  la  never  wituewMl. 


tir   TOLUNTART    XOVBHENTt 


811 


I 


The  KitilU  nre  most  ctear  wheii  llic  current  «!iii|)] ()>■«< I  u  a  Mimulus  u  nit 
*tmi|;er  iliau  ujusleufficieflt  tujinxlucetbeapimiprmitf  m'iveni«Dt  (roufcbl^ 
apeskini;.  n  ctJirenl  jtiat  perceptible  to  the  limuve  uf  the-'i|)ersti>r  U  in  ordl- 
lutr*  ciuen  a  u*eAil  i>De\  ami  when  (he  cnrlex  in  in  ipiwi  i)ii(ritiv«  condition. 
In  luy  ox)ierin)i^iit  ihc  r««iilt«  ohuTriMl  )>y  tliceurlicr  rtimulntiom.  W)on  after 
Um  cortex  bu  IxH-n  expowcl,  aro  lh«  brat ;  nlU-r  n>)>i-«l<i)  attuiulatiiMM  the 
Mirfiior  n  apt  to  become  bypencniic.  iind  it  iw  thra  rrv<|ucntlv  obaerverl  tlwt 
tbw  ntOTCiuentM  nwultiiix  from  the  Rliiiiiilalktii  uf  h  [uiriicular  area  are  not 
OOnSlKtl  to  the  appmnriulo  miivclc*,  but  «prvad  to  the  (^Trnpniidiiig  niUNclea 
of  the  opporito  aide,  (nen  to  musclfl*  oouiio'letl  irilh  other  i»fLical  amu,  aiMl 
at  iMt  to  Ifat  iDUKclffi  of  the  body  generally ;  itt  the  Mini«  time  the  move- 
BMDta  loH  tbcir  diMinclire  piirpiwfut  chiintctT  mid  (be  niiinial  i»  ihmirD 
into  convulsions  ol'  an  e|>ilepiif>irm  kind.  It  not  urifrrqiinuly  Imppeit*  that 
an  pj[|*finwnt  hn*  to  br  Mopped  in  «>iwr»]iieiicc  of  tbo  onset  of  the*c  epilep- 
tifoftii  c»nviili>i(inH.  The  n»poii»o  of  movement  to  sttmulation  niiir  bo 
obecrvnl  white  the  animat  is  under  the  moderate  inHiicnoo  of  an  nnresthvlie, 
ImjI  a  lo<>  profound  niiir^thesia  leMona  or  annuh  tbo  eflccts. 

In  order  to  rarry  out  a  cinder  annlvi-ia  of  the  phonomcRn  it  is  dcsimble-  to 
«atch  or  record  the  coniraelion  of  n  pnrticulnr  group  of  niufelee,  or  porhniM 
better  still  a  ]>anicular  muecle,  p.  p..  (be  nreti  for  extension  of  the  hind  limb 
■nay  be  studied  by  help  of  the  eKC«nsor  dif^itorum  communis  of  ibe  limb. 
Wh«n  this  is  done  the  fullowini^  important  facts  may  bo  obvrved :  The  anm 
of  cortex  having  been  found  which  jfivea  the  beet  niovemenls.  and  the 
Kimulus  haag  no  stronf^r  than  is  neoeaHTy,  isolation  of  the  area  from  )t« 
lateral  Burrouodintp  by  a  circular  indsion  carried  to  gome  little  depth  n-ill 
But  prevent  (he  development  of  conlractiitns  in  the  muscle;  but  tlieM  do 
ceaae,  even  without  the  circular  incision,  if  by  a  horizontal  section  th«  eray 
cortex  is  nparated  from  tbo  fubjncent  white  nuitier.  Alter  removal  of  the 
corlMC.  Mimulatiiin  of  ilie  irbitn  matter  underlying  tbo  area  producea  the 
appropriale  conlraction  ;  not  only  however  i«  a  stmngitr  ittimnliiit  Deocautry, 
but  aUii  ihr  latent  ptrii<d,  that  is  ih<!  time  intcrvtmin^  Iwin-i-cn  lh<-  beicrnning 
of  the  n|>)ilicatioa  of  the  Ntimulntini!  current  and  the:  lH-(;inning  of  the  mut* 
rular  c»ulractii>n  lit  appni;inbly  nhorteued.  The  approprialiT  cHiulnictions 
Dot  only  apjiuar  when  the.  whit<'  matter  immcdiiitcly  ln-Kiw  the  I'ortox  ia 
slituulalrd,  but  hy  niukingndccewiveh'irisonlul  aoelionii  and  stimutnlingi-Hch 
in  (urn,  the  *-lli-i-t  m«v,  so  to  #i>r-jik,  be  traced  through  the  eititral  white  mailer 
of  ihu  hemisphere  "(own  to  the  internal  capoule.  \V<t  nmy  cnnelud"  from 
thcM-  rc>ult«.  that  when  thv  eiirrcni  is  ap|>linl  to  ihv  surface  of  the  cortex, 
oenuin  parts  of  o^rtain  struetum  in  the  gray  matter  are  stimulatod,  tli« 
pruMas  naving  a  nuirkea)  la(cn(  period,  and  that  as  the  outcome  of  tho 
ebuigea  induerti  in  the  gray  matter,  iniptilsva  paa  along  the  fibrea  Icadinic 
iloirn  from  (he  gray  matter  to  (he  internal  capsule  and  m  by  tho  pwlal 
kyslem  uf  fibn*  to  ue  apinal  oord  and  motor  s)>inal  roots.  The  anatomical 
consiile  rat  ions  advanced  in  a  previous  section  hiad  us  to  «ippo<e  that  tlic 
fibres  in  cjiiestion  belong  to  the  great  pyramidal  tract,  on  which  we  have  bo 
much  insMed ;  and  as  we  sliall  see,  all  our  knowlcdi^  conlimn  this  view. 

It  must  Dot,  however,  be  Fup|>oeed  that  the  several  areaa  stimulation  of 
vhieb  produoes  each  its  di<linetive  movenieot.are  in  the  doK  sharply  defined 
lVo<n  each  utber  ;  when  the  term  area  for  exteonon  of  the  hind-limb  is  lued, 
it  mu«t  not  be  BupjKxied  that  the  area  can  he  defineil  by  an  otii'int!.  within 
which  Htimulation  prodiioM  niilhtiig  but  extension  of  the  hind-limb,  and 
ouUade  which  iximulntion  never  pruduee*  extension  of  (he  hind-limb.  All 
tlial  is  mesnt  i*  that  rxteonion  ••]'  thv  hind-limb  is  the  salient  and  ftlrikinf; 
Nwlt  ofMlmulatinit  the  art-a.  Wbr'n  we  study  the  various  raovetnenia,  and 
wptdalljr  perfia]a  wlien  we  ntudy,  bg  l>«lp  of  a    raiihic  record,  the  oon- 


812 


TUE   BRAiy. 


tmctSoM  nf  vnriotit  injiviiliinl  mu«oI«s  Ksnltlng  from  th«  ftimnbtioe  of 
Turioua  paru  of  the  motor  region,  w«  (tixl  mA  nnlr  thnt  Hk  areai  (bf  fw^ 
ticuliir  muvcinctiU  or  pnrticiiliir  miKclm  nra  very  <liflu««,  but  tkAl  tbetevpitl 
arau  largely  iivcrlnp  «ich  olhi-r.  Il'  for  iiiftaiin^  «t>  were  l»  map  out  oa  lb 
tuns  dia|;riini  the  several  nms  belonging  (o  four  nr  fiv«  muntes  of  diKfM 
nnrls  of  the  botly,  biicIi  m  the  cxtpnwn  of  Ihr  Aigitf  nf  Uie  fora  wii]  of  tb 
nind-litab,  lii«  flexors  of  the  ^ame.  nod  ihe  orbiculitr  muaclc  of  tb»  fftfiJ, 
that  u  toaay,  tbeBevernl  Hrena  irilhin  which  in  turn  Mimtilntioii  of  tbeeDlln 
produced  coDtmclioii  of  the  jiarticuliir  miifote,  the  ovcrlappiug  would  br» 
mat  that  the  whole  li^ure  vould  appear  bichly  o^nliifd.  In  a  iiimiUmT 
tno  excitable  motor  rej^ioa  as  a  whole  would  };nidually  inerg«  inin,  W  hriiL«ti 
up  into,  the  uiiexcitable  tVontal.  occipital,  and  temporal  regiona,  io  frini. 
behind,  and  below.  In  other  words,  Lh«  localuation  in  tlie  coriax  of  itx 
doe  is  to  n  marked  de^'ree  iniperfeci. 

In  this  respect  the  do^,  corittitondin^  to  ils  position  in  the  animal  biennkf, 
is  iDterniediate  between  aiich  nuimaU  as  the  rabbit,  the  bini.  and  the  ln^,iia 
the  one  hatid,  and  the  more  highly  developed  monkey  on  the  other :  asd  thu 
is  oDO  rcnsou  why  we  have  taken  ihe  do([  tint  aitd  dwelt  w  long  anon  it.  In 
the  rabbit,  a  umilar  localization  may  be  oluierved,  but  far  (a»  oefiaiU,  la 
more  diffuse;  it  Itevomea  Mill  Ii9«  in  the  bird,  and  ii  hardir  racoKoiaUcia 
the  fro^'.  It  will  not  be  profitable  to  dwell  ou  the  detaiu  of  ui«M  Inn 
animals ;  but  the  plieiiomcna  of  iha  monkey,  lending  up  oa  tbey  do  lo  UiM 
of  man,  call  for  ai>eeial  notice. 

§  656.  Whitn  in  a  monkey,  in  no  individual  for  inttanee  belonging  to  ibt 
jfeaoi  Maennu,  the  fiirfan-*  of  the  oerebnim  it  expton-d  with  refenMel* 
tlie  tfftct*  of  electric  «liitiiilntii)n,  it  is  found  that  when  the  eiirrvnt  ia  appM 
to  the  precciilrul  or  iis<i<iidins  frontal  nnd  the  pxrt-centnil  or  oacondiaf 
parietal  convolutions  which  lie  respectively  in  front  of  and  l»hind  ibt 
iniporliint  central  lissore  or  flsanre  of  Kolando  (r^.  Fig.  '2t)^t,  movwiMlitl  tl 
theforr  limb  follow.  The  "  motor  area  for  the  fore-limb  "thiu  diaeufmdii 
more  circiin)scril>ed  and  dciinile  than  is  (he  oorrospondiog  area  in  iha  ivf, 
lu  outline  (Fig.  ^iHj  is  roujrhly  that  of  a  tnincaled  trtanele  biaocled  by  IM 
rentral  li»ure,  with  the  broad  bone  at  some  distance  from  tne  m«»ial  liar.ul 
the  triiDoated  ajtex  reaching  on  the  lateral  surface  of  the  hemisphere  t»i 
well-niarketl  bend  in  the  loner  part  of  the  central  flsaure.  Behind,  it  mi-l« 
as  far  as  the  inira-piirieiAl  ftMure  which  somewhat  eharply  defines  itf  bind 
bonier,  aud  in  frunt  it  cciMea  no  leaa  definitely  at  aome  little  dtmincv  IwhioJ 
ihepreceniral  tia&iire.  Further  examination  ihows  that  the  whole  areab 
divided  into  areas  correoponditi);  lo  movementa  of  imrticular  parU  on)* 
forearm,  and  that  Ih^M-  nn'  nrmnged  iu  a  defihile  relation  to  each  olhrr. 
In  tbe  more  dorml  jiart  nf  llic  area,  nl  (he  liaiv  of  the  triangle,  atiiuulmtm 
produceM  movement*  of  Ihohouldcr  (Fig.  '20J  <;  if  the  electrodes  be  vhifitJ 
veDtraliy,  movemciil«  of  the  elbow  make  their  uppoarunce;  if  atiU  mm 
veulrally,  movomenle  of  the  wriM  come  in,  and  tiMWC  are  in  turn  MioeeeM 
\-entrallv  by  movement*  of  the  digits  generally,  of  the  f<>n.'finij:i-r,  and  Laitlf 
of  tlic  tliumb,  A  very  striking  experimont  may  b«  made  by  applying  s 
cunent  of  suitable  streiigtli,  lirst  at  the  lower  ventral  border  of  tli«  am, 
and  then  gradually  advancing  iipwurd  toward  the  mmial  Hne;  the  thumb  >> 
moved  lintt,  then  the  foretiuger,  then  the  r«^t  of  the  digits,  then  llie  wrwt, 
next  the  elbow,  and  lastly  tbe  shoulder.  Further,  in  certain  parts  of  tbt 
am  tbe  resulting  movement  is  flexion  of  the  appropriate  segnieot  of  tba 
limb,  in  other  pairtti  extension,  in  certain  porta  abduction,  in  other  paM 
adduction,  and  so  on. 

Similar  eiploratiuo  show*  that  the  "  area  for  Ihe  hinddimb,"  ties  on  tbt 
rocdinn  side  of  (lie  area  for  the  fore-limb,  stretching  besides  on  to  the  mc^ 


OSr  VOLPFTJ 


VOTBMBXTS. 


nrflwe  al'ififr  ilio  margiual  eonTolution  whicli  fanm  l)ii-  dortnl  pi>rlioii  of  the 

■nil  of  lli«  gTvM  ltiii];ilud)Dal  IWiire ;  it  rvaclioM  lut  fur  liiu-lc  m  tlic  intn- 

■ivtal  lulcus.  utd  is  aueocetJed  ui  rnml  t>^  tbn  "  uvn  for  tho  iruiilc  "  (  Tig. 

)),     WilliiQ  liiis  general  Hrcn  fur  the  hiixl-linib  wc  mmy  xiniilnrlj  distiiu 

lU)  •[weial  urans  Tor  i)m>  lup  (Fii»i  204,  205)  in  th«  rroiil  porlton,  for  the 

tnc*  UMi  ank)«  behind  thia,  and  Ibr  the  diglu  atill  furtlx-r  backward,  the 

•n*  for  th«  greu  lv«  being,  however,  Id  front  of  ihe  nrai  for  the  other 

I  digit*. 

Fib.  SB. 


I 


i 


littftr.  frvitla/M 


V 


J^r 


xi'* 


>. 


»MpTi9r  frantal 

X 


^ 


t 


->'J 


X 


•et/fittm/. 


I 


Orrun  or  aatto  or  MmKET  (JAioinui  ro  euoii  rnutupAL  tvM  ifiwiiKt*}  «ra  otu  (Oovto- 
UTTKUUI.  r^wliiMvroiialUiHonuiYUidSnitnuLI  NaiorKl «lw. 
Tin  bnln  Ofiml  li  Ui*  aimu  u  ibnt  In  Fit.  IM.  «nd  ili«  i>u  Otim  ihoiibl  k«  cunnilM  UgtOm. 
Ont  M«b  mIcw^  lariiowljr  i-rliiwtl  v«rT  Ihlck.  tb>  mum  I*  WritMil  111  imM  mpUali.  om  «Mk  BTHM 
la  mNm  >  tndkaw*  Uw  «n>LU  •l«t>nMiau.  lurdlr  %o  In  wll«4  a  nlous  vblob  I*  loppcNad  lo  t« 
buMWliBim  vltb  Uw  wpfrior  tanHl  nlnw  oT  man :  aiwl  Oi  r.  ^  iiwlarljr  ladlaaia  tuM  whow 
liiwnlrnlw  an  ntn  nirlain     rorioimiriionri'uaalVi'SOT.sm. 

In  fVont  of  the  areas  for  the  limbs  and  trunk,  on  the  inediaD  dorsal  sur- 
fncv,  dippiiig  down  into  the  mesial  surface  along  the  marginal  eonvolution 
(Pig.  2(u)  and  reaching  laterally  on  ihc  lateral  d'>r>ai1  aiirface  to  the  dorml 
MlremltTof  the  precenlral  8iilcus(KiK.  204),  i«  lhe"nrvn  for  the  head,*' that 
ia  la  aa^,'  for  ibe  raovemenia  uf  Itead  Drought  about  bj  conlrvctions  of  llie 
nuaclea  nf  the  Deck. 

Vcntfal  to  ihii  again,  in  front  of  the  prec«Dtml  iiik-us,  is  (h«  "area  fur 
Ibe  eyes,"  that  i*  to  aur,  fur  cciuractiona  uf  the  ocular  mueclee ;  and  behiuii 


814  TilK    BRAiy. 

ll>c  nreoentnl  Nulcuf,  venlml  to  the  arm  area  lies  m  snuUl  *n»  (or 
of  Uio  eycliilii,  l)ri>iight  nbuut  by  cualractiiHM  of  ihe  orbioularit  ntoirh. 
Ventnl  to  lliis  aguin  u  ihtt  "  nr«a  fur  the  fuoe,"  in  irbicb  we  may  diatinguU 
no  nmi  fi>r  the  mflulb,  tliiil  in  an  un-a  atiaiulation  of  tihirh  |>roduL-at  cWpf 
in  lh«i  biici'al  tirificv,  vjicning,  filuittitij;.  <lruvrii);(  to  unc  tide,  (He.,  uiil  mt  un 
for  n>uvenM-nl»  'if  the.  limguv.  Thnw  two  mms  rvticb  dunnnRnl  to  tlis  faauit 
of  !?ylviiin  atxl  iHii'kwnru  tn  the  line  of  the  iHlra-|)«ric<al  >u)vua.  In  fnoii/ 
thcni,  occiipyinf;  «ll  thu  vi-ntnil  pnri  of  tlw  proctntrml  convoluliua  iiU 
rvuL-liiiig  furnHrd  lu  for  lu  tb«  precuiUnil  Mulcua,  wli«ra  it  nioi<ta  iba  un  to 

•ITJ 


*«..■  -  ■  "^ 


«  ION 


lip  "."'t -*iji.u!i:     ,  oiiiTs 


VISION 


t^T 


Lett  Uuamau  or  rat  Ciiuai*Lum  or  Mokxkt  yttaraaut.  Viav^  raox  n>  Lm  >m  «• 

rtOM  AtovE.  (SiiiuiNnroH  mHit  llnOMii  and  HkkvoIi.)  VbIuivI  ttm. 
Thv flvum ihosi iha  i<aiIUonior  ihepurtinnioT  luc cortex  nxMnncd  wKb  mnTfawntrf  wni 
101  ri«.  kiid  Willi  lliowrw.vof  ittlit,  uDcli.  niii1  IimRIik>  TIm  torUrml  KNa  ronneettd  wM  Ha  ■»• 
■mrDUuf  tlw  lifU  iliiuIfO  mrtlcall;  lurruB.  Ihai  w)Ih  Ihc  mintmenta  t4  llic  WB  tiod*mil>II;.ial 
Ida)  «iUi  Uw  uiUTOUunU  of  ib*  trunk  jii  a  ilautlnit  <llm!lloii:  Uio  ana  (OUiicinl  alDithram 
■MliNoT  (III  liiail  iiwckj.  tk<x,  4Iid  eja  u  dollpl  Tlicc«i|i>«  oT  Uw  OhlaTllBUia  b  ladbuM  )f 
tfucle  llnix, 

the  e^,  lies  an  area  (tinmlation  nf  which  pmducen  ntovcumts  ot  tb* 
jiburyDx  ur  laryus,  at  w«ll  u  tbo  motiih  or  face,  itud  which  maj  be  diTJM 
iuio  areas  for  inantii-aiiou,  for  ■vrallo<ring,  and  for  tbc  prodocUoa  uf  Lh* 
voice. 

We  luiglit  s|>ealt  of  tbeK  Eeveral  arciu  iu  aiiotli«r  nny  by  referring  to  tk 


OK  TOI.USTART  MOTEMEST8. 


eio 


ncrr«  cooconird  incnrniiifioul  tlwMvcrol  miivcmentit,  though  itnloingwi  we 
mtut  ntii«nilMr  tli«l  lh«re  t*  Dot  nn  exoct  corrtopoudcncc  between  tlio  tvlntive 
pantiii)  nf  m  mufclc  nlonft;  rli«  nxia  nl*  the  body  or  aloDg  the  axu  of  »  limb 
Mid  Um  raUtivo  potiliuQ  along  tlio  oervbro  i[>iiinl  nxi*  of  lh«  norvc  or  nerves 
govaraina  lb«  mutdai  We  roar,  however,  wtopting  this  method,  nott?  ibst 
the  MuraT  aod  lumbar  oervtt  are  rcprvMnted  \>y  (he  moat  racaial  portUm  of 

tta.X6. 


)Ua*l  Unet  ortNX  I.nr  lUi'  or  tin   Ktitv  i^r  Ui'icn,  l>Mrt4V«i>  hy  Sutmv  v  nrR 

HnlJlV  SUfTTlL  PLAKX  and  RDtOTXL  OT  THK  CUtMll.ltU.      IVUUUIHUTOH  ■Acf  HOMLtV  kod 

7«M  hMclMd  and  MlppM  tiMU  «#  UK  tnrtlee  (bow  ih*  rvglcdu  or  Uw  mtcs  coDiwMid  wUh  »aT«L 
mmatolih»fitl.hin.Up.tafI,trwnJt,tadtitrtiweaYtlj.  TiMHvaalpaMtlDaiaril»«nuo(aci(Mi 
IHliXtfIrt  ■!«>  ttMim  and  iwrf  ■mi  •tiOi  niaiimu  tmalitm  t«  Indtratgl  tr  Iha  ■ffnupif au  wortl. 
tt^HM^o^—ttontMimBJiliwiBrt  thetorpnifHamai,  <f..  ff  .tf..«na  thioiitlithaaiitwior 
caaBAanr*. «.  qHtiif  iha  lal)  pillar  o(  Uw  fiitnli.  K:  baUiid  ii  ii»i  UinM  iw  anwtUir  fart  of 
ihBf«wla]PlvopaUMB«iMdiui.  il4.  nor*  ivfUa  ad  quanniDTimliViiluin);  itot;  tto IvR  hal/ 
of  tka  foaalu  ftfiaMMMooiCy,tteapileeeaiiUau»cut  acioc^  in.  UwimtcJ  ihvtlilnlnaRte) 
turn:  rM.  Om  bontal  tola;  Oe,  Uw  onlrlial  fula:  0>.  dia  cuscw:  JV^  Ih*  mnncw:  0>, 
0^  0/a.  tba  iTTv*  fc«>l(ati» :  iho  tinlciioivd  DMirv  •«««  U>  (um  lb*  a|i|cr  boundaf}  ut  ■»■■? 
fynia  Id  IU  npis-CBlknl  t^n  1'  <1h  «all«ci-iiiamlnal ;  ivy.  ibc  |«ileli>wri(atal  Oman. 

the  whole  motor  area  and  br  the  hind  diviiion  of  this  mntal  portion ;  that 
the  lumbar  and  thoradc  nerves  are  repn^culed  by  the  fVonl  divt»IoD  of  the 
mma  neilal  portion;  that  the  upper  thorncic  with  the  lower  cervical  nerires 
beloDg  to  a  region  iytnf;  lalemi  lu,  nod  the  upper  cervical  nervM  to  one  lyinff 
in  fmnt  of  llie  prectnliu^  area;  mid.  lastly.  iliHl  thu  rt^muiuing  lateral  and* 
vrtilml  portions  of  tlie  whule  uiolor  region  afijierluin  (u  tliv  cninial  nerves. 
Rut  tliv  Ui]»ij;riiphic-ul  ditferenlistion  does  not  come  out  im>  clearly  by  this 
inrlhoil  na  by  thut  of  iiikiti);  fur  our  guide  distiuettve  niovemeuu  of  the 
teveral  imrt»  of  tbe  biniy. 

It  will  be  ubicrved  that  all  tlieae  areai  laVen  together,  RprMented  by  the 
portion  of  Figi.  204,  205  aliaded  in  one  wav  ur  auoiher,  occupy  chiefly  tite 
parietal  irdoo  of  the  evn^hral  surface,  thoufih  they  alao  reach  into  tbe  frunlul 
region,  fiumulntinn  of  tbv  fnmuil  region  in  fnnit  of  this  motor  area  or  of 
the  occipital  region  behind,  nhethrr  on  the  lateral  or  on  the  meaial  surfaee, 
or  of  the  temporal  region,  wheilier  abo  on  the  lateral  or  on  the  mniol  sur* 
fkcK,  or  of  the  gynis  fornicotii*  (Fig.  206)  coADecling  the  frontal  and  occipi- 
tal npons  on  the  mnlnl  furfiice,  and  running  ventral  to  the  nuirginul  ^rut, 
doM  not  give  riec  to  movcntcnte ;  or,  to  be  more  exact,  doea  not  give  ruw  to 


816 


TBIC    BRAIN. 


tDovemenU  coropantble  to  (o  those  just  dMcribed  M  resullitiK  ''^'"  MiiiHli^ 
tion  of  vaiioUB  purte  of  llie  motor  reginn.  MovemeDls  do  take  j>liuc  «faA 
ceilaiu  parts  of  the  occipital  or  of  the  (empoml  reinon  are  BtimuUioJ.  bat 
ibeee  an  nut  only  feeble  oud  expcriuienlaltv  uiicerlaiD,  but  appear  to  btti 
a  diSereni  nature  from  thoae  r«ftitl[iii)f  fruiu  stiiutilntjoii  of  the  uiolorragtM, 
it  will  be  cuDveiiwDt  to  apeak  of  the  iialun>  and  meaning  of  thn  kiJul  af 
Riovenieut  when  wc  vonie  to  diecuaa  the  dovelopuent  of  aeDsatJon*. 

§  6ji7.  It  i»  obvious  fruu  the  foreguiog  thai  the  inecbaniBro  for  tfaederelt^ 
ment  of  these  moveiueiils  uf  cerebral  origiu  are  far  more  bijfbljrdifleroitiittil 
in  the  monkey  tltou  in  the  dojf.  ilul  even  in  die  monkey  (ifaraeiu ud 
allied  forniaj  ihe  ditlbreoliatiou  ia  atlll  very  iucouiplcie.  If  we  ezulore,  fct 
inatance,  the  area  fur  the  nrisl,  we  l!nd  that  )t«  hmiia  ate  illddiixd.  In 
some  parts  of  Ihe  area  we  obtain  utovenicula  of  the  wrift  only,  but  in  othtt 

Eiirts  of  the  area  sliimilation  iirodut-eB  not  ouly  moreinL-nts  of  tUo  iirul, 
ul  al»o  of  the  aboulUer  or  of^ibe  digits,  or  of  the  nvck;  mk)  M>  witk  tlw 
oiber  areas. 

If,  hiinever,  not  a  Maeaciu  or  other  ordinary  monkey,  but  th«  more  higUf 
derelojiMl  vurangoiilanc  betaken  aa  theaiihjcctof  exiierimenif.thedilwo- 
tiatioii  ill  found  to  bedislindly  udviiiic^d;  the  fcvcral  arena  are  m<irc  olinrplj 
dvfmtil,  and  what  ia  iiupurlaiil  to  iioli-,  the  rcflfx.'clive  an-an  (riid  to  be  Mf» 
raitd  Iriini  ouch  by  putllon*  of  cortex,  ntiniulation  of  which  givtv  rtw  to  aa 
moveniMit  at  all. 

The  o[ipiirtmiiiiLit  of  »timnlnt!ng  the  cortex  of  man  hinurlf  have  been  tn 
and  far  lietwei-n,  and  bnve  for  tlic  mofl  piirt  been  conducted  under  unfu\-iir- 
able  circumntBUCi-*;  but  an  far  as  the  rcvulH  m>  obtiiineil  go,  lh«y  sliow  ihil 
the  lopoKtaphiciil  dirinbution  of  Bn;n«  for  the  acveral  movements  is  carrM 
out  on  the  mnic  plan  as  in  Ihe  monkey  (wc  are  purposely  cunlinios  ouiwItm 
now  to  the  results  of  arlilicial  etimulation) ;  and,  moreover,  Justily  the  cq>- 
clnaoD,  which  li  priori  reasons  would  lead  ua  to  adupi,  thai  in  man  the  dif- 
ferenUaiiou  is  advanced  still  further  than  in  the  monkey. 

Thus,  when  we  survey  a  series  uf  brains  in  sucoeasiun,  tVooi  the  nior«  lovlf 
frog,  through  (he  biid,  the  rabbit,  the  dug,  ami  other  lower  mammals  up  la 
the  monkey,  the  aiuhmpuid  ape,  and  do  to  man  himself,  we  liud  lui  incrn» 
ing  diU'ereniiaiiou  of  the  cerehral  curlei.  by  which  certain  areas  of  the  oortsi 
are  bruiighl  iutu  sjimal  couiitctinn  wiib  veiluio  skeletal  or  other  mtiacln  ia 
such  a  way  that  slinmlatiuu  uf  a  uarlicuiar  portion  of  the  gny  nwtUr  jptm 
rise  to  a  particular  nioveuieut,  and  to  that  atone. 

§  6fi9.  In  treating  uf  Ihe  structure  of  the  brain  we  u>ok«  ($  633}  of  tie 
pyramidal  tract  ua  utsriing  frum  the  motor  region  of  the  cortex :  anditii 
obvious  that  the  librca  of  Ihin  tract  miixt  be  conevmcd  in  llio  development  vT 
the  movemenU  which  ne  huve  junt  described.  When  the  mavDnieniSBn 
biuujjhl  about  by  nliuiulntiuu  of  the  Rbrai  in  some  {latt  of  their  cuurw,  in  tbr 
inieruiil  ciiniiule,  fur  in»[anc(r,  [here  can  be  no  doubt  that  (he  stiniuloliaa 
starts  inipuUi-n  which,  iruvclliiig  down  Uiu  tract  to  ll»C  origins  of  oertsin 
crauinl  or  itpinul  nerves,  in  (oinc  way  give  rise  to  co>>rdtnaie  motor  iinpuiw 
along  the  laulor  fibres  of  ihc  ner\'t9 ;  un<l  tie  mny  with  rcn«un  speak  uf  the 
iinpuUc*  ihcD  passing  along  the  tract  u  motor  or  cSl-rent  in  nature.  Whni 
the  stimulus  is  applied  direct  to  the  cortex,  wc  may  assume  that  procwu. 
started  in  tlie  gray  maticr,  cvcntualo  in  similarly  eilerent  impulsca  aloo{ 
the  fibres  of  the  tract.  All  the  evidence  lends  us  to  regard  tbia  traet  aaati 
eRercnt  tract. 

Whet)  i))«  spinal  cord  is  divided  in  ibe  lower  dorsal  region  and  tbe  tieo- 
trodes  of  an  electrometer  on  brought  into  connectivn  with  the  troneverte  cot 
surface  and  with  some  point  of  the  Kingiludinal  surface  above,  the  electro- 
nieler  giv<s  evidence  of  currents  of  actiuo  (.uanilested  aa  negative  variatiuiu 


ON    VOLL'MTABT    H0VBMBXT8. 


817 


^11  •InnirctttuincuTnnlornirrcDlnf  n.M,§  67)  wtirnerer  the  motor  sre«  of 
the  hitiiMliiili  i«  HtiimiUt«0,  but  not  when  othiT  pitrtttof  tbucorl«x  nrastiiaa- 
tnu^.     Wc-  hnv«  iilr«adj  Mid  tlinl  «limulnti<>n  of  aiiy  nnrt  of  tlit>  motor 

p'lD  may  uiMlcr  Bboonnal  c'in<Hlinn#  givo  ri»c  to  general  epilcptilbrtn  coii- 
iont:  vhvti  tbtMoecur  <liiriii):  ciicl)an<>xpcHmpiil)u<  the  above,  ctirrcnta 

'  Mlion  nianif«t  thunMlvce  in  lh«  lower  dorMil  lord,  whether  the  stimula- 
tion givitij^  riw)  to  the  convulsMtis  bv  ajiplieH  to  tlie  area  for  th«  hin^-limb 
or  111  any  fiart  of  tius  motor  rrginn.  It  Km  bMin  further  obeerTe<l  that  the 
carrcnis  of  action  d«vel<i}H!>d  irithin  tJio  >{pi>i>l  <^'^  lallv  in  a  very  exact 
manner  with  the  muBculnr  movonicnta.  Th«  eonvulgioDB  begin  with  n  bus- 
lain«d  "  tonic "  contraction  of  tbo  mueclee,  and  the  electrometer  eIiowb  a 
(tmilar  auMained  current  of  avtiun  ;  this  is  followed  by  rhythmic  moTemeiite 
of  the  mwelci;  accomjitinied  by  correBpondiag  rhythmic  niovcmCDls  of  lh« 
awrrury  of  tli«  «lectroiaet«r.  Without  in^isling  too  much  on  the  exact 
interprelatioD  of  tli«e  results,  we  may  take  them  as  at  teaat  shonin);  that, 
«hi-n  the  lootor  region  of  the  cortex  is  excited,  nervous  irniiulses  acconi- 
|iaiii«d  by  "  currents  of  action  "  paaa  downward  aloog  the  fibres  of  the  pyra- 
mi<Iiil  IrHcE. 

Thv  [ittults  of  Btimulating  the  fibres  of  the  tract  !□  tlieir  cmirae  throu^ 
theeoraDaradiatauodilieiiilenial  oapaule,  and  tbereeultHubmined  hy#tudy 
mg  the  de)(eDe rations  fdllowiug  upon  injury  to  or  remnvul  of  the  seveni]  parts 
of  the  cortical  motor  region,  agree  in  marking  out  the  pullia  taken  by  the 
several  couilittienta  of  the  tract  throu^'h  the  central  uiittt^  matter  of  the 
faemisuberc,  the  coruiia  rudiata  aii'l  the  cajwule.  Comparing  ^'fP-  -*>^f  -'*'* 
with  Fijp.  litO,  200,  and  201,  it  will  be  seen  that  the  purtton  i^f  the  tract 
daiincij  for  the  cranial  nerves,  and  so  l4>r  the  movements  of  the  eyes,  the 
nouth,  fact-,  tunitue,  pharynx,  and  larynx,  starting  fVom  tlie  ventral  jwrts  at 
the  morf  frunlnl  di«trirl  of  Hie  motor  ivgioo,  take  up  their  jHMJtion  ai  the 
knw  uf  the  internal  opBule;  and  the  portion  destincid  lor  tho«o  upper 
cervical  iM-rvts  which  carry  out  movements  of  the  head  through  the  mu«cl«a 
of  the  nei-k.  siaHin^  from  the  extreme  fnintnl  and  dorsal  |>arta  of  the  area, 
la  nlw)  appareiilly  direclcd  to  the  knpc  of  the  cap>ulo.  The  rest  of  the  tract, 
tuning  from  t^ie  part  of  the  area  lying  at  once  behind  and  mcvial  to  the 
above,  occupica  in  the  catwiile  a  petition  posterior  to  them  id  the  hind-limb 
of  tbe  capaiue ;  and  it  will  be  obwrved  that  the  inict  for  the  lore-limb  which 
beipna  on  tlie  surface  lateral  of  the  tracts  for  tbe  trunk  and  hind-limb,  shifts 
its  course  in  rclntion  to  llieirs.  so  that  in  the  cajMule  it  is  in  frurit  uf  them, 
not  lateral  to  titeiu.  It  mav  further  be  observed  that  while  in  the  tmcts  for 
the  trunk  and  bind-limb  the  same  tore  and  aft  order  which  obtaiiiecHi  ibe 
surfuc-e  is  reproduced  in  the  capeule,  even  apparently  to  the  Strange  prece- 
dence of  the  ankle  over  the  knee,  the  order  of  the  aeTenI  elements  in  the 
fbre-linib  tract  which  is  lateral  on  tbe  surlnoe  becooiea  regularly  fore  and  aA 
in  tbe  capsule.  In  tbe  capsule  the  several  elements  are  arranged  in  a  linear 
order,  corresponding  brou<lly  i»  that  of  tlie  diatribution  »f  the  musdee  along 
the  lonKitudiual  axis  of  the  body ;  on  the  cortex  thev  are  disposed  in  an 
order  the  cause  uf  which  is  at  proient  nut  very  clear,  nut  which  i*  probably 
determined  by  the  r»(>e«iive  rctatiuus  of  tlie  several  parts  uf  the  motor  region 
to  the  functional  activity  of  the  i>ther  paris  of  the  cortex.  In  the  tibi(ting 
ftoni  the  one  order  to  the  other,  tlw  several  oMutitueiit  fibres,  as  nv  liave 
nid.  deai-rlbe  a  *uiUL>what  iiccultar  ciMirwo;  and  when  we  remi-ml>er,  a?  atatcd 
la  i  6tU{,  ibnt  the  onlcr  slioun  in  Fig.  Uiit  it  only  the  order  <ili(ainin^  at  one 
particular  level  uf  the  capMilc,  and  that  from  the  doranl  beginuutgs  of  tbe 
i-aptulc  in  the  corona  nidiatit  to  its  ventral  end  >D  tlie  pes  the  caiMiM  is  con- 
tinually cliaagiBg  in  famx.  and  iia  fibm  therefore  continually  shifting  tlteir 
relatione  tueach  ollker,  tl^wltole  course  of  tbo  etfvaral  fibrm  of  tliv  tnu;t  ffvin 

U 


I 


TITE  BBJlIjr. 


their  origin  in  tlie  corteic  uotil  tbey  are  e"t'>^'^i^  >*P  >■>■<>  ^  eutnl 
or  the  ]>e«  (Fig.  lU'J,  /y)  idubI  be  a  very  complicalcM)  one. 

When  the  area  nf  one  heraieph^re  ta  etiiiiulated,  ilie  movemnit  miiA 
reaulu  ia  in  most  caa^A  seen  on  the  other  tide  of  the  body,  ami  on  that  odiir 
tide  alime.  Thus  when  the  area  for  the  fore-limb  b  stimulatMl  on  the  ML 
bemiti|iliere  it  is  the  ri^bl  fure-liiub  which  ie  nutveil-  TU'a  b  in  sconnluet 
with  uhac  we  have  learned  ol'  the  pyramidal  tract  and  ils  ultiuiate  cniin 
decusration  befure  it  reacliee  the  motor  iiervee,  the  decuamtiou  either  oetat- 
ring  n>a»tively  as  in  the  case  of  the  crwKil  pyraniiiUl  tract,  or  in  a  mtn 
scattered  tiiauiier  along  ttie  upper  pan  of  ihe  spinal  euni  in  t)w  cue  of  ikt 
direct  pyramidal  tract;  and.  an  w«  have  aeen,  there  is  a  nmilar  decuMatiio 
for  Bucli  pari  of  the  i)yraiuiiial  Iraa  as  in  connected  with  the  cranial  ucrra 
above  the  ilecuatation  of  the  p]rraiuitU.  Kxce|>t  in  the  case  of  certain  arot 
for  U'lveiiienis  naturally  bilalentl,  of  which  we  stiall  speak  pmeoUf,  Ik* 
ragveiueni  ia  normally  on  the  cniHiwil  fide,  and  on  lh«  eroaiid  tide  nly. 
Uu'ler  abnormal  oonditiouit.  howevtr.  the  liuib  of  tbc  other  sill* — lba(  ii^sf 
the  BiUiie  tide  at  the  hemisphere  sliumlalcil— may  move  abo.  But  Mchia 
ahuormal  ni<ivenient  of  the  same  side  biut  not  tli«  nroe  character*  a*  ib« 
projtff  luoveuwfil  of  the  crowed  limb.  lunlcnd  of  being  an  orderly  oa>ili> 
uate  inovenieiit,  it  is  a  more  aimpic,  cither  tvlanic  or  perfaaia  touie,  *t 
rtiythmic.  clunic,  uontructiun  of  the  muscle*.  Obviously  iia  uwduuisa  b  tf 
a  dilleruiil  nature  from  llint  by  whit-h  the  proper  movement  of  tbe  croaal 
limb  is  effecteil ;  but  it  ih  important  to  bear  in  mind  that  a  nKivcmaatlf 
ihe  uncriwwetl  limb  riiay  tiike  place;  and  further  that,  tbc  abnormal  caodi- 
tiuiis  continuing,  rqmilar  mnvcmeuls  of  an  uncoordinated  character  a»t 
iipread  to  the  hind-limb  anil  other  jiartsof  the  cn»Kd  aido,th(Miffh  llwitiaia- 
laiion  bo  alill  contiuod  t<>  thv  arm  arc*,  llirn  t<i  Klbcr  jmrls  of  iImi  uiKtraal 
side,  until,  ti*  we  have  said,  the  whole  body  if  thrown  into  epileptil^im  mi- 
Tulamw.  Thi*  feiiturc  muHt  not  be  forgotten.  In  fact,  it  may  be  Uiri; 
instfWd  upiin  thai  while  we  may  speak  of  a  (nrlicular  cu(~>niinate  oMnatM 
us  being  the  normal  outcome  of  an  ordinary  careful  stimulation  of  a  par 
ticular  arm  in  a  normal  condition,  it  is  no  Icea  true  thai  did'use  uucu»rdia>t«i 
movements,  cilloiioating  in  general  epilcpliruroi  coovulsiuns.  are  tb«  nstunl 
outcome  of  tbe  Btimiilaiion  of  any  area  in  an  abnormal  cyindition.  Aud  ia 
attempting  lo  t(>nn  any  opinion  of  the  nature  vf  tlte  6nl  Act,  we  nnal  beat 
the  second  in  mind. 

As  ve  Mid  above,  the  movements  iveulting  from  cortical  siimulaii<>ii  aa 
most  conveniently  described  in  terms  of  parts  of  the  body — of  the  arm,  of  ik 
thumb,  of  the  tongue,  elc.     Tbe  moveinunla  of  the  same   pan  uay  ht 
further  distinguished  by  means  of  Ihe  n»menolMure  usually  nd>ipt«d  ia 
speaking  ('(  muscular  movements,  such  as  flexion,  eslensioii,   ftbductMO. 
adduction,  etc. ;  so  that,  within  tbe  area  bearing  tbe  name  of  aome  parlicnlu 
part — such  as  the  wrist,  for  i^slall(^e— ne  have  lo  distinguish  an  area  for  iW 
fleiion,  and  another  for  the  extcimon  of  that  joint :  and  in  like  mnniwr  ia 
refervnco  to  other  parts.     But  it  will  be  rMdifv  umieratooil  that  it  ts  easin 
to  map  out  tbe  area  for  a  {xinicular  {mrt  than  to  dtminjj'iiab  the  an-as  e»r- 
responding  to  the  aeveral  movements  »r  ibut  part.     Huiice  ilir  uMmcnclaUirt 
UHually  8du|>ted  in  speaking  of  the  m>>l<if  n-^ion  U  one  biuol  on  tbe  (kartaof 
ti>e  biidy  moved,  rather  than  on  the  character  of  tlw  movements.     Tli«  ntort 
cloeely.  however,  the  ui»vemcnt»  in  ijucation  nre  studied,  the  mora  proliabb 
it  appenrb  tliat  tbe  liicalixaliou  nbich  obtains  in  the  cortex  is  easentially  a 
localixation  currea{>uuiling  not  to  tiart«  of  tlie  body,  or  to  nervw,  or  to  inaa- 
cics,  but  to  movcmcnio.    In  coniiilcritig  ihi*  point  it  must  be  fcmenibeieil 
bun'  rude  and  barbannii*  a  mcthixl  of  Mimuintion  is  th.it  of  applying  electMdes 
tu  tlie  surfacv  of  iliv  gray  matter  compared  with  the  natural  ttimuliuioo  nbtufa 


819 


taiiea  p^Att  during  oerebnil  action ;  ilie  one  prrtbably  ii  about  as  mudi  like 
>tt  is  rtrikiof;  llie  keys  of  ■  pisiio  nt  a  distance  with  a  bnviiiMiii'k 
to  Uie  exeriition  of  u  skilled  musidnn.  Wert  it  in  our  power  la  stimulate 
Um  rortes  iii  any  way  at  all  approadimf;  th«  natural  method,  wo  should  iu 
■II  iiniliability  arrire  at  two  results ;  ou  the  one  hand,  we  should  be  able  lo 
produce  at  will  a  ramly  of  muremeiits  of  ditfereot  de|;reea  of  vuinptexiiy, 
■one  very  simple,  otbcra  very  complex,  aud  for  these  we  should  have  to  use 
mtBtt  sugKested  by  the  characters  apd  piirpofe  of  each  movemeat,  au<l  Ity 
thcH  khwe:  on  the  other  baud,  we  should  tind  very  decided  limits  to  the 
Dtimber  uti  kind  of  movemeiiU  which  wo  couhl  evoke,  limiu  fixed  in  the 
CBM  of  each  subject  (Minly  by  tuherit«d  or|{iiiii£utii>D,  partly  by  (be  iruoiu^ 
of  the  iadividual. 

Some  Buoh  results  of  relln«d  ex pvri mentation  are,  indeed,  already  fore* 
■)ind<iw«d  by  ibe  rude  ratultoofour  prfisent  r»uKh  methods.  The  uiovcmetitjt 
which  uauullr  follow  ttimuUliciu  <if  the  inutor  region,  an<l  which  *ie  have 
dnMTtt>e<l  a*  llcxi'iu.  utc.  an-,  no  t'l  ununk,  the  elementary  fuctori  of  ordinary 
budily  moVL'uivnif,  thu  di-tathtiil  and  iuiperfeul  chords  uf  n  iiiuitical  piece; 
and  iu  the  fotluuiu);  fnclii  rfliiliuj;  to  llicir  priHluotiou  tiv  can  recMgiiize  llw 
iuliuvotitit  of  iirjtaniiatiLin  and  hnliit.  As  we  have  Mtid,  stimiilution  «i'  the 
ruulur  area  of  one  beruinphi^rc  pnxluow  movementn,  at  n  riik',  wbicli  arc 
limited  to  uue  hUU'  nf  thv  Imdy,  and  thai  the  opfiiMtlc  side  Now  b<)t)i  in 
unnolve*  and  in  the  bigbiir  animals  a  large  number  of  bmlilv  oi<ivonic-u!«L, 
capeeUlly  of  the  tinilHt,  arc  habitunlly  undntcral:  and.  puKiii^  luidc  ihi^ 
4)il«alk>n  why  there  nhould  be  two  halves  vf  the  bntiii.  ainl  why  llie  <in<>  half 
of  tbo  brain  »h»uld  be  OMociniwI  with  the  crow  half  of  the  tKNtily,  wc  may 
rMOgnixe  in  the  unilnlcml  cr>»!cd  niovcncnt  raulLing  from  Htimulniion  of 
the  cortex  an  accfirdancu  with  natural  habits.  But  some  movements  of  the 
body  ire  ordinarily  bilateral;  'he  two  eyes,  for  iiutnuce,  are  ordinarily 
niuveil  tii^lher.  and  the  two  side*  of  the  trunk  move  together  very  louch 
mure  Ire'^uenily  than  <lo  the  two  fure-linibs  ur  the  two  hind-limlw.  And  in 
acioordance  with  this  we  lind  that  Dtitiiulaliun  of  the  motor  area  for  the  eyes 
on  eitlicr  hcniisphcrw  pnxluceit  moveuii-ntd  uf  hi>tb  eyo»,  and  atirnulation  uf 
the  trunk  an^a  uf  one  hemisphere  is  aUo  very  apt  to  pruiuce  bilateral  at'tion 
of  the  trunk  musclei ;  iu  such  instances  the  movemenu  on  both  aidm  are 
cjuiie  normal  movements.  We  may  iociileiually  remark  that  remoral  of  the 
trunk  area  leada  to  a  jcoiid  deal  of  bilateral  de^'i^nerntiim,  that  is,  to  d«)[ener- 
aiiun  ufftiramlit  in  iheiiyruniidal  tracts <iftiuih*i<le«,  whereuMch  a  bilateral 
deiceneratiun  is  L-»wparatively  scanty  after  removal  uf  the  itg  ur  arm  area. 

That  it  is  the  mtivemciit  and  not  the  iiart  moved  which  ts.  so  to  afieak, 
repcvMnled  on  the  cortex  t*  further  ihowii  W  the  relative  m.i^jnitudia  uf  thL> 
several  cortical  areas  when  (Ii«y  are  map|ie(l  out  accordiii);  tu  parts  of  the 
iMxJy.  Tlte  are*  for  the  arm,  fur  instance,  cf.  Fig*.  'Jll4,  205,  is,  so  to  speak, 
raormoua  compared  ti>  that  of  (be  trunk  when  (he  relative  bulk*  of  theK  two 
partt  uf  the  boily  are  oon^idercd  ;  and  within  thv  arm  area  ilMilP  the  spncc 
ooeit|ne>t  by  the  thumb  and  lun-linger  and  diyit*  i»,  bulk  fur  bulk,  out  of 
proportion  to  the  (pace  allnited  to  the  vibouhler ;  so  aUo  the  area  fur  the  cyM 
or  (ur  tlie  mouth  is  out  of  prupvrliun  to  thu  stxv  of  thoM  organs.  But  thiM 
niklive  uies  of  the  rc*pectivo  nreoa  becomo  inielliglbla  when  wc  bear  in 
reUlirc  mobility,  nimblenoM,  and  delicacy  of  exeuuliun;  in  themi 
the  shoulder  is  far  behind  tli«  thumb,  while  the  eye*  and  muulfa 
moot  other  parts  of  (ho  body, 
^c  are  broui;hl  yet  a  step  furtht-r  when  we  conpdu«,  Id  rMpMl  of  the 
rorlieal  motor  iv^ion.  anintals  uf  ditlert'nt  i^rodee  of  vrgonitallon ;  and  the 
results  thus  obtained  lead  us  to  the  conclusion  that  (be  motor  region  is  orrc- 
laied  not  to  movemeuts  in  general,  but  to  mowuietila  of  a  jMnicular  kind. 


8S0 


TQK   BBAIN. 


Tnking  in  wriee  tko  nbbit,  tli«  doe.  tbe  nonkcr,  Mid  man,  w«  find  io  pwring 
from  ono  to  tho  otlwr,  lui  incmso  m  proniincuioe  Knii  in  dirrvrrntUlion  oftW 
motor  rvgion  Bccompnnicd  liy  nn  incrviiKiiti  tho  balk  of  tlii:  prntmiilAl  met; 
nnioDf:  tile  mmt}-  itrikiiig  itifttrciK-rs  betwBcn  the  bnin*  of  llwM  Hvcnl  anl- 
mnl«,  ihcpc  l«o  fcnitii'PK.  thp  jncrcasing  complpxilj  of  tbr  motor  n{(lon. asil 
lli«  incrtnsiuj^  i^ize  uf  ihc  pyrnniidiil  tnicl,  nr«  among  tbr  tncet  rlriking.  Tbi 
»ii«  of  llie  nrramidnl  tract  is  ilwlf  corrclnlcci  to  Ibo  comploxily  of  lb«  motor 
region,  find,  beinf;  the  marc  rBsily  detcrniined,  may  be  uwd  as  iodintiog 
butb :  the  difl'^ienee  in  tbe  sine  of  the  jiyniniidal  tract  in  tbeao  a&iuaU  ii 
eeen  tUI  along  tbe  whole  length  of  tbe  cord  (I-'ig.  20tt).     }4dw  aa  nguil 


rio.ao>. 


rvi 


MAN 


HOHKWY 


OQS 


DiAfliuH  IO  liuvncATi  mi  Rkutit*  bus  or  the  funAMWAi,  Taimr  la  nu  Doo,  Hovui,  u> 

Mt.S.     ItaSmMITOH.) 

Til*  flgnM  ibDin  In  oailioe  Uic  laicnl  hilf  of  iheciirt.  Mlka  loiol  of  HioaitblbonelowH 
tn  A,  nwD ;  B.  monkvy :  C,  dot .  A  It  ■  rriirodncUcin  uf  (*  iii  rii.  Iiq ;  b  uid  C  tn  ilniwn  c>  IM 
Mm*  dw  M  A.  JV-  iludod  oblliilKlr.  the  p;runi>l>J  tncl ;  Ihe  depth  of  iihtdlDff  lndl<at«  IMO  U< 
Inol  ll  Dorn  rrovdnl « Itl)  tnic  jirninWiii  nbmm  wrll  m  larfcr  In  A  (lun  In  a,  ■ndin  atkanliC, 
In  8.  jyiiui  oallilnc  ponlnna(ll)^I7nmlll■l  inoi  Kfanldl  ftoinUiCNM  bf  the  «*tfIj(1Iu  ImM 
JV.il.  Uw  direct  tTTWnldal  incl.  pnwnl  in  maii  oulr.  Tbv  (Imr  ■MWrotat  rMIvsIt  luvtHC 
t«nawll)«wciluii  XHiolen  rrdiunTeijjbuiiif  |iup|>]r, 

mera  ouanllty  of  raovenient,  if  we  may  use  such  an  exprcaion,  the  diflir- 
eiicca  DdwiL'H  ihte«  aninmla  are  of  uo  great  moniiiit.  If  wc  were  (u  take 
tbe  nniount  of  energy  txiicnded  aa  luovi-iiivni  in  tvrfuty-four  boutf  per 
grunmiG  of  iiiiinrle  prenirnt  in  tbe  bodv  Eu  t-iich  of  the  four  caan,  we  alxwtil 
ccrlniiily  not  find  imy  i:urrta|iondpDce  Dctwcun  that  und  the  fiw  of  the  pyr» 
midnl  tmct.  If,  however,  wc  take  n  particiihir  kipd  nf  inoveinviit,  what  «a 
niDf  pcrhapa  cull  (killed  inuvnnrnt,  that  la,  miivcnicnt  ratrii-d  out  by  meaiu 
of  iiilriciilc  chniigt-a  in  llic  cciiirul  ntrvmia  ayalcni,  wc  do  find  a  rcninrkabk 
p<iralldi«ni  in  Ibe  above  ctim-»  hvlwccii  thv  iimotint  of  viich  akillnl  tnovcmtui 
vnlciinp  into  tbe  daily  life  of  the  individual  and  iW  cia;  of  tho  pyramidal 
tract.  In  thcae  two  rrviwcla  ninn  is  much  nhovc  ibc  inoukcy.  and  the  monkey 
far  above  the  dog.  ^^  v  may  concUidc  then  Ibat  the  conicid  niutur  region  » 
in  Fonio  nay  »]>i'cinlly  couctmcd  with  tb«  kind  of  movement  which  we  ban 
i-nllcd  "skilled.^' 

$  QS6.  These  skilled  inovciiienlB  are  to  a  Itirge  extent,  though  not  exda- 
aively,  voluntary  luovcmeuiB.  We  hnve  in  a  prcvii>u<  section  eeen  reaaon  to 
ibdiere  tbal  the  cerebral  cortex  it  in  some  vny  especially  awocialed  with  llie 
deretopmenl  of  voluntary  movemeDts.  Putting  logelhvr  this  conclusion  and 
tlw  oouelusiousjuat  arrived  at  we  are  iiaiuntlly  led  lo  the  further  concIuaioD 
tlial  tJi«  cortical  tuotor  region,  uilli  the  )iyraiuidal  tract  belonging  to  il. 
pliiya  an  inipurinut  part  iu  carrying  out  voluntary  movemeata.  Di>  tuber 
&cl»  support  tbJH  view,  und  if  ao,  nlmt  light  do  ibe^  throw  on  llie  c|Uce4ioD 
at  to  what  purl  and  what  kind  of  purl  the  luolur  region  thus  plays? 


ON    VOLUNTAKr    MU  VKU  KNTS. 


esi 


1u  ihb  eoaneclion  we  nntumllir  dnira  in  kwiw  what  are  lite  results  ofS 
rvniovi&R  frotD  aii  mfaerwiHo  Iniact  luiimul  the  vrbole  motor  r«Kia<i.  nod  more  | 
flqweiftlly  ihu  ur  iliat  iwrtictiUr  (M>rLiuD  of  iL  Before  prm.'eediuif  further, 
bmnver,  we  may  mioe  mure  call  attenlion  to  the  uiiitiuii  f(iveii  in  $  oOA,  aad 
npMtad  in  S  641 ;  imleeil,  when  we  eoiisi<ler  ihe  hiftli  organixMiou  ami  com- 
plex AiBctiooa  which  obviotuir  b«li>nK  (»  the  cortux.  when  we  bear  ia  mJaii 
llutl  it  ai>i>eara  to  ffnwrn.  am)  miim  thcn'fore  W  hound  l>jr  clone  Ihw  to  almost 
all  ilie  Kttt  of  the  L-viiinil  iit-rvnuH  *y«teiu,  nc  inuat  be  prc|>iire>)  to  tliiil  after 
rWDoviuK  A  portion  of  ci>rifx  that  the  pure  "<iefineacy"  pheuomeiia,  iIiocM) 
«hich  naull  fntm  the  inere  itlixcacc  of  a  pieco  of  llie  oortex,  are  larfcely 
obtcureil  l>v  the  other  cfli«t«  of  ihv  opemtton. 

Ill  the  rabhit  the  rcniili*  luivv  liii'ii  nlmiwt  pureir  neeAtivuL  When  in  thi* 
aniual  the  (nirl  of  the  cortex  which  may  Iw  coiixiilereil  M  the  nurtor  regiuii 
U  rerooved,  nolhiiiK  roninrknblv  it  obverved  in  [he  uovoiiietilJi  of  ih«  unimiil. 
We  can  hnnllj  xii{ipi»(!  that  (ho  0|>eralion«  of  th(<  contml  ni-rvuii*  Hvntcin  nro 
the  «ame  iu  an  o|M-rnleil  iif  in  an  intJict  tmimni,  nnd  tliv  ditlrrvncv*  imlucwl 
ought  to  be  brlntTcil  by  the  movuniunts  uf  tlic  body;  but  nl  prtnont  ifaey 
hare  <wca]>ed  olwcrvation. 

In  the  do);  the  reiDoval  of  bd  area  i*  followed  by  a  loM  or  dimitiutiou  of 
voluntary  movement  in  the  cvrratpooding  part  of  the  Icidv.  Wb^-n.  for  in- 
alHn<x-.  tiie  area  for  the  fore-limb  is  removed  froin  tli«  lull  bemi'pbere.  tho 
ri)£ht  fore-limb  ia  eumoletely  or  pAriially  "paralyied."  In  carryint;  out  it* 
o^innrv  movementa  the  opernle^l  nuimnt  makes  little  or  no  u«c  uf  ila  riy;ht 
fure-liinK  Rut  this  stntv  of  thin^  is  temporary  only.  After  «  whi la  the 
animal  renins  power  oi-er  the  limb,  and  in  HueeeMful  ooaea  reooTl^ry  is  so 
complete  that  it  is  impoasible  to  point  out  in  the  limb  any  iippreciablo  devia- 
tion f^>^l  the  norniiil  uw.  And  eareftil  examination  after  death  has  shown 
not  only  that  the  aren  had  been  wholly  removed,  but  also  that  there  was  do 
Rgeneratitm  of  the  hot  imrld ;  the  removal  uf  the  cortex  leads  in  such  caaea, 
M  uaaal,  to  de;^neralioa  of  the  cornspoinlio;;  »lrand  iu  the  pymmi<tal  tract 
right  awuy  l'n>m  ih^-  rerehral  mirface,  tu  the  endiuK*  of  iho  strand  in  the  oer- 
Tjoal  and  donal  spinal  curd.  Nor  raiii  it  be  ur^l  in  such  awei  tliat  diOused 
remiiaJita  of  the  arm  an«  hnd  Iitvd  lofl  in  tlui  raiuunin)i;  |iatl.->  of  the  motor 
refiioH ;  for  the  wholt-  motor  rc)pon  has  been  nniOTcd.  an<l  y>-t  the  aotmal 
haa  r«coTereil  to  sueh  an  ext«Dt  that  a  casual  ohaerrer  could  detect  no  ditler- 
cnoea  between  the  movementa  of  the  (wo  >i<les  of  the  body.  CluMr  examiua- 
tiou  did  difi^loiie  certain  im  per  feet  ion*  of  movcmonl;  but  the  Ofiention  had 
involved  injury  t«  or  priMluced  c)isn);ce  in  structures  other  than  the  motor 
rtgioa.aw)  the  impcrlectionf  niij^ht  have  lice n  duo  to  tlir  additional  daniaan. 
Morcan  it  Iw  nr^ed  that,  in  such  a  ca«-.  where  one  oide  i»  removed,  tne 
reiuuning  hrmispbere  takes  on  double  functions  :  for  the  ^rvutvr  part  of  the 
motor  an-u  have  been  reuMved  on  both  sides,  and  yrt  the  animal's  m»v«- 
rornto  have  iMvn  so  far  apparently  complete  that  a  casual  olnervcr  would  see 
nothing  si ran}M  in  them.  Ag^in,  the  whole  motor  region  bos  been  removoi) 
frcicn  one  hemisphere  in  a  yooni;  puppy,  nnd  sometime  later  whvn  llw  (nixrc- 
ments  seemed  to  have  rcoivered  iboir  ncM-nal  condition,  (he  removal  of  the 
mot4>r  rej^ioiii  of  the  other  hemisphere  has  produced  merely  a  paraltvis  of  the 
criMsed  side  of  the  body,  an<t  that  as  bef>>re  only  of  a  temporary  chanu'ier. 

Two  things  have  to  he  noted  here.  Iti  the  first  place,  the  removal  of  an 
area  does  siTiH^t  the  iDOveroeuts  which  are  brought  about  by  stimulating  that 
area,  it  leads  to  their  dinppearanee  or  at  leant  lu  i;reat  diminution  of  tlwm  : 
and  this  aHiirda  ati  niliittional  arcumeut  that  the  ooiuieciion  between  the  araa 
and  the  movement  ia  a  real  and  important  one.  In  the  aeoond  iilace,  thtt>l 
physiuloffical  effect  ia  lemporar}'  only,  thouj^h  the  analomical  results  of  the 
operation  are  permanent,  for  tlie  cort£x  is  never  renewed,  and  the  pyrmmidnl 


823 


TBB  BRAIN. 


Iraet  degenenitea  nlnDK  its  «  hole  Irogth,  never  to  be  n»tar*>l :  th'w  •b'tui 
thai  we  have  to  dest  bcre  with  events  nf  m  wry  complex  cbnnictvr.  Wliiv 
a  pHrliciilar  iDiiveineiil  multf  from  Blimnliitioii  of  the  tip{iro|irinl«  eartii'sl 
nrea,  we  may  be  sure  that  whatever  takes  place  in  the  mrtox  anil  nloog  Uit 
pTrunii<)al  Imi'i,  inouir  imrul^^es,  duly  co'Winated.  pass  alun^  certain  >&!«• 
rior  roola  lo  certiuii  rhim-'U-s;  and  we  know  ihm  if  we  reniDVol  a  sulSnfM 
length  of  Mfh  (if  thi'U^  anterior  ruoia  that  fianicrulnr  movemeut  mikiM  ht 
li*l  for  the  rt-rf  "f  the  life  of  thr  incliviiliial.  We  may.  iherefuf*.  infer  ikai 
the  cvvutN  whi<'h,  nhait!vi-r  be  ilii-ir  eincl  nature.  lukinK  plucv  in  the  rona 
and  along  tlio  pyramiilnl  tract  Ictiit  iiltiiiiutrly  to  iIh:  imuc  of  molor  Impute 
ulong  the  anlcrior  nmti.  ililter  ■■RH'nitMlly  fWjni  the  evcDta  attending  ik 
trnnHmiMion  uf  oriliimry  motor  impulKii. 

In  thi:  cn«c  of  the-  monkey,  the  mult*  of  reuioriof;  parla  of  the  tntlhil 
raotnr  rejci^o  hn\'e  nni  iH-rn  no  nc(?onliini  n*  in  thi^  I'luw  nf  the  'log.  Tht 
two  animnU  a^i>  iirrfvclly  in  ■»  fnr  that  tho  roniovnl  of  a  jwrlicnilar  an* 
leniln,  a*  an  immnliale  rrsiilt,  to  the  him  of  tlM  Oormiwin'lini;  miiveiiMil ; 
hut  wliilo  in  *nmp  inxtance*  nrcovery  of  the  moroionil  Iiiif  in  (he  ninnkeyu 
in  the  dog  aftvr  a  nhile  taken  place,  in  oilier  instaiH^cs  llx'  "  iMralran"  las 
appeared  to  be  pcrmanmC  As  a  rule  the  pamlvHS  Miiml  by  a  lar^  IrtM 
is  Dot  only  niorv  extensive,  but  also  of  lonf^r  dunitioii  than  that  cniiinl  hr 
a  small  one;  and  natural  bilateral  moTemcnts.  as  of  ihe  erv*.  rv«pp«r 
earlier  than  iinilatL-ral  movements.  The  facts,  however,  witltin  otir  kimwl- 
edf>e  relnlin);  to  the  permanence  of  the  effeet  arc  neitlter  nuincrimit  nomad 
enough  to  justify  at  prevent  a  definite  crincluBioii.  On  tbe  one  hand,  th* 
paeitive  csma  where  recovery  has  takeu  plm-e  are  of  more  value  than  ths 
iM^tive  ones,  since  in  the  latter  the  recovery  may  have  been  hiodend  hj 
concomitant  evenis  of  a  natun^  which  we  may  cull  atciiltiilal :  and  It  if  at 
k'li^l  It  priori  mtBt  unlikely  that  thi;  pyramidal  Iriict  nici'haninu,  if  we  niajr 
nsO  tho  i>x|>ri'iuiiin.  I  hough  il  mnv  dilb-r  in  (bo  moiikrvam)  the  dog  in  ckfTt* 
of  develop  mi -lit,  ditl'i-m  m>  eawntmlly  in  kind  ihat  damagi?  of  it  lend*  in  lb* 
one  case  to  pcrmaoont,  and  in  the  other  to  mere  (cm{iorAry,  lij««  of  ftinedoa. 
Wo  may  adil  that  «<■  .nhould  further  oxpect  to  meet  in  the  monkey  with 
more  prominciit  and  more  lasting  complicnlions  due  to  the  suluidmry  cdrdi 
of  tbe  operntioii,  and  il  may  be  lionbled  wlMrthcr  in  any  of  th»  rvcurdid 
evperimcnis  tiK-  animal  ha*  been  allowed  tn  live  n  sutBeicnt  time  for  ibw 
subsidiary  eveniK  In  hnvn  clearvil  nway,  having  only  ohnt  ve  have  nilbd 
Ihe  "delieieney"  phenomena,  due  to  the  loss  of  the  (sorties)  area  ainnc.  On 
the  other  hand,  it  muit  be  rememben-d  that  iho  mnventenls  of  the  u>onk«^ 
are  more  iulricute  in  origin,  more  "skilW  than  those  of  the  d'lf;;  and  A 
may  be  lliat  diHerences  in  the  characlcre  of  movenieuta  determine  the  pdw- 
bility  of  ibeir  recovery.  In  illu''tr,«tiou  of  this  we  may  fguoie  the  expe- 
rience thai,  after  the  removal  of  the  arm  area  in  the  monkey,  a  oenaia 
awkwardness  in  the  movements  of  (he  (humb  is  one  of  the  last  eBVcta  oftW 
operation. 

§  680.  Bcibro  wa  pmoeed,  however,  any  Ainher  tn  Iho  discussion,  it  *i|^^ 
be  of  adviintnge  to  turn  aside  to  wliat  is  ktionn  concerning  ibe  c«>nl^^H 
motor  region  in  iiiRn,  As  we  have  already  said.  the<in.'tiL*al  eoiujiIeratJai^^^ 
lead  us  to  bcliere  that  the  cortical  motor  region  lu  man  u  disfiuaed  tu  nccunl- 
ance  with  the  plan  of  the  anibrapoid  aiie  a*  aacertaiuod  es  peri  men  tJilly.  bvl 
with  (he  diflt'rentiation  carried  siill  lurthcr;  and  llw  few  caaat  of  OJtper*- 
mental  stimulation  of  (be  human  cortex  support  ihi*  view.  Our  chi«f 
knowledge  in  ibis  matter  is  derived  from  the  atudy  of  diacase;  and  In  tbit 
the  advantages  of  dealing  with  one  of  ourM-lvos  arc  lar|i«ly  connterbttlaneol 
hv  tbe  disadvantages  due  to  disease  being  m  olV-n  anatomically  dillbsa  and 
|tli}-ei<iIogically  vbangeful  and  progrcMii'V. 


OS   VOLDSTAUr    MOVEMBXT8. 


828 


"We  Mi'I  almrn  (hat  iluring  «s]>rrint«nt«  on  niiimali*  atimulnlitm  of  any 
pATt  of  iltu  iTKilor  rrfpon  may  iiiii)<t  nbiivnDnl  nKiihlimiii  Ii-ml  in  i;Mi)!mI 
vnilvpUform  ounvulawxin.  Now  cliiiicnl  ftudy  liiia  showii  llijit  id  man  certniit 
klildl  of  vitilvptic  nllni-k*  iirr  of  Miiiiliir  cnrlicnl  nri^m.  In  tlione  ciim!S  it 
his  bcon  ooHrrcH  that  thr  mtark  ln-^in»  in  n  ptttliciiliir  tiravcnieat,  by  con- 
tfaetkmt  of  (Mrticiilnr  miiKcU*  or  of  ilir  imiK'k'*  >*{  it  luiriicular  rrffi'in  nf 
Die  tHiiJy,  «f  iho  haix).  foot,  tor,  ihiimb.  <>ir.,  and  ihrii  xpmiilii  in  a  liofiniic 
ordrr  or  "  miirch  "  over  iho  miiK-lc*  of  other  n-giorw  iiiilil  the  vrhok  IhnIv  is 
iavolvrd.  When  in  nn  fxporimrnt  un  iin  miimnl  cpilqiliform  conrulsions 
Mipfrrfnp,  thry  jimilarly  »i"rl  fn-m  ihe  region  of  the  l«>iiv.  the  motor  area 
.  of  whii'h  u  Iieiieaih  the  electrtxlrx  at  the  time.  nnH  »nnii]iirly  spread  by  a 
i]e6nire  "  march"  over  (be  whole  body.  Hence,  in  ibe  htiman  e|iik{>tiforiD 
attack*  of  which  «e  ar«  cpenkini;,  it  bns  been  inferred)  thHt  tho  immediate 
«x«iting  oaiiM  of  the  Bltsck  )■  to  be  nought  in  events  Hiking  pliice  in  that 
part  of  tbe  eorlex  whieh  cervee  as  the  urea  for  the  movement  trhich  ushers 
intbenllnrk.  Further  in4|uiry  hns  Dot  only  coofirmed  this  view,  but  baa 
aboBhomi  tbnt  the  tonography  of  the  eorti<«l  areas  in  tiuiti.  u»  thus  deler- 
tnined,  very  cloeely  follows  that  of  the  niookey. 

Other  diseases  of  (Ik  eartei  have  been  ninrked.  among  oth«r  sytnptoins, 
hy  Ion  or  impnirment  of  pnriicular  niovenieiils.  In  must  of  siieh  co^es  the 
cortical  krioD  bns  been  of  such  sn  extent  ns  to  involve  a  number  of  s|>eetal 
areas  at  tlie  same  time,  nod  «o  to  lend  to  luna  or  impairment  of  inoTeraent 
over  relatively  cunaiderable  rej^ioiifi  of  tbe  body,  such  as  the  wliota  of  OUB 
arm ;  and  ii>  general  the  teaching  of  these  cases  of  disease,  while  eoafirminit 
ilia  deductioDS  from  the  monkey,  and  givin;;  us  some  general  idea  of  tite 
topof(raphy  of  the  human  motor  cortical  region,  has  at  present  given  u> 
approximate  n-sulla  only.  Figs.  209  and  210  ahow  in  brund  diagrararaatio 
maniwr  tlw  im^iuud  and  relative  extent  of  tbe  motor  areas  for  the  leg,  arm, 
and  fae«  in  mnn,  ni<  far  ax  bai  yet  beun  awcrtaincd.  To  aiwist  the  reader 
we  givi!  ul  tbe  ninie  lime  dingrams,  Fign.  *2))7  and  208,  illuatraiiog  iha  do* 
ncDclalurc  of  the  surfaiT  of  the  hunmn  brnin. 

One  ana  is  of  special  and  in«troclive  interest.  Sp«*ch  is  an  eminently 
"skilW  movemctil.  We  havo  »wn  that  in  the  monkey  tbe  arxia  for  the 
mouth  and  tongue  lies  nt  the  ventral  end  of  the  eeiitml  timiire  or  fissurv  of 
Rolnndo,  ventral  to  the  arm  area,  and  that  the  extrrrae  ventral  and  front 
p<irt  of  the  motor  region  just  above  the  Hwurc  of  Rylviuo  supplies  nn  area 
which  we  marked  as  that  of  pbonation  <  Fig.  'i04).  In  the  monkey  the  area 
of  pbonation  is  determine<l  by  experimental  stimubition;  in  mnn,  in  a 
similar  position,  on  (he  third  or  lowest  frontal  convidmion,  R>metimes  eallct 
Broea's  convolution,  ventral  to  and  in  frvmt  of,  and  probably  overlapping 
backward,  tbe  area  which  in  Fig.  'JU!>  it  marked  "  tnc«,"  and  which  incluwi 
the  mouth  and  tongue,  clinical  study  has  dtschwetl  the  exiatenee  of  an  area 
which  may  l>e  spoken  of  ns  tbe  area  of  "speech."  Lesions  nf  the  cortex  in 
this  area  cause  a  Icm  of  or  inttrlerence  with  speech,  i 
known  as  aphatia;  to  this  we  shall  presently  return. 
■8  shown  in  an  approximate  manner. 

The  movemenls  of  epeeeh  are  eaaentially  bilateral  movements.  In  tbe 
dog  awl  monkey  various  bilateral  movemenia  may  be  excited  by  stimulation 
of  tbe  apiiro^riale  area  in  either  hemisphere ;  and  analogy  would  lead  us  lo 
Biipjiotie  that  lu  man  the  movenK'ut«  of  siieech  would  be  connected  with  (ho 
ff)e^-h  area  in  b<>ih  one  and  the  other  ncmispbere.  The  results  of  leniomi, 
liowever,  show  tbnt  it  is  in  moat  caaca  eapeoiallr  tbe  left  bciniaphere  which 
Is  connected  with  i<|ieeeh;  it  b  a  leaioa  in  tbe  third  frxmlnl  convotutinn  of 
Ika  left  hemisplK're,  olten  nsaoeiated  with  other  Iwions  of  ilie  same  b«Rii- 
•pban  leading  to  paralysia  of  the  right  aide  of  the  Iwdy  and  facv,  which 


'h,  the  condition  being 
In  Fig.  :209  thia  area 


89$ 


THE  BKAi:r. 


c«ue«»  nphuia,  it  Wing  nnlr  En  cxeoftfioiMl  etut»  thai  Ihc  oonditJOD 

from  &  IraioD  of  llio  comspf>ii<ling  nrca  of  curlcx  oo  tl>e  right  bemiapbore. ' 

Id  maD,  thcD,  clinii-al  study  corroboratcc  tlxt  oMicliudoot  dcdtiCM  turn 


R  0 


.0*) 


I'?-.: 


nr-O.! 


^ 


^■«A 


-*' 


;^>r5 


lO  B  C 


^ 


't>. 


'■^^ 


T  E  M  Po  BUL 


-OB' 


UluMT  iUwu-HDi  or  Uni'.    «to*tu) 


Ftc-W, 


0..B,  ,E 


.^;^«»i«. 


^*/. 


TM 


I." 


UntjJ 


.N 


■Xo 


ot 


The  ume  oa  mx  Uboal  Scwao.   (OomM.) 

tn  botti  llfiixM  ttia  uiipl  an  luiliioMd  tr  <Mle  >nd  ll»  oMiTolaUoni  I>t  roniKii  tni*.    TIm  IhUaa* 

lliBlUto(wnici)>iioi]}miiiiiT)>crhB|Bl)coI  UN  to  omDMIlcti  Willi  Uwrc  Ikllla  >Dd  tboMcf  tt* 

tnln  or  Um  luonicy  iFigi  OK  uul  afl). 

Oyrf  «r  nnnvlurriHit,  rm«ntni1  nr  anUrlar  rantml  —  unndlns  ftonul.  fodccMnt  or  ir^ilw 
tmn«l*>*«siidIni[|iiuteDiI.  SupMorMmpanl-lDtM-aaigliMlvilnKcnironi.  Triuvular loboto 
aninau*,  C»nti»J  tobt-MUwl  nf  Rsfl.  frntiionitnl  int>Ul*~lli«  tnoaUl  Ikta  of  Uh-  raprfMr 
(raoMl.  >HIilD  lliv  nuflRiil  trnu.  (.IhsuIdtii  —  Uie  |«/i  of  tin  qtih  toniliialiB  wblch  ul)Daa>tl>B 
eorpo*  oalknun.  Ojtut  hljipaiamft "  aaiilotUi  lym*.  UhmikIi  Uu  laltn  nuDO  li  KiinrllnM*  i*- 
iMoivl  Io  ibc  ftwii  t«tt  of  tliB  lil|i|NMiuii|«l  grtvt :  iha  iin>  mir  ta  caitUviwl  oi  a  aoarUniMUiin  i4 
UnsTTua  fhrnloMiu. aod  ilw  Uim  lnc«lher.  flitDi[i«B  Brtn,  turn  btoa  tallnl  "Iha  ^isl  linUo 

aiM«r/bnira.  OmUmI  —  HfiUndIc  or  of  Rolando.  nqViuUcnlBr— farlOI»<]eel|4l«L  t^nsul 
—  tain'infleMJorwiBfUmeiUiWr'puMBL    TVmionwpbencMalloto— tempomllobo. 


rOLUN-TABY    MOVBUEXTS. 


825 


rimenliil  iDTefltiKiitioD  of  the  dog  and  of  iho  moiikcT,  but  (till 

FM  ill   iinoeriaintv  oa  Ui  tbe  (|ue8tioa  what  noil  whiit  nloiio  arc   tlto 

lutelj  permwieni  eSeeta  of  the  loos  of  a  oirucal  arra  nn<l  mithiag  eUo. 
tfa*  OHO  hand,  io  Um  cam*  in  which  reoovery  of  a  moviMnenl  Tullow*  upon 


rio.  nti 


f~i.'^  t 


lft<- 


-J» 


Oe' 


M  EARING^ 


Smal  9emr»ea  or  nm  Rioirr  CMtaau.  HEHnmmt  or  u«m  ih  OvTuya.  to  iLuvnun 
T«i  Cmtiul  Aaau.    (KcdoMtf  (Torn  natniv.l 

TM  pnlUon  of  llw  anw  of  Ui*  conoi  couocraid  whb  noTamant*  of  ItM  Am.  arm.  &nd  les.  •x'l 
■1B>  Uie  wn—  of  dibt  mJ  twriin  «»  *ppwjlm«t«lr  ilwuni,  TlwimlUMartlM  «>««  eooiuwMit 
«iUi  itiMfk  (BfOM**  omifTlHilao  ihnn  fbr  iba  Mike  Of  dMttMlmi  of  II  wlib  (bo  tadtlnncf  IM 
Ml  tb*r«i>«>cnutiuii  i>r*imui»itwranajce(miil  U■^  bowvrer, In  ibc ^  bomUvbcn 
Oe.  L,  wclplul  lobt.  Ft.  L.  frooUl  lube:  ft- 1.  MuiponJ  lot*:  ^,  /.  itw  •*■««  of 
1i*:  C./.  ibei»DUmlitMim(Ki>Uiv1lc];  Ctn./iliidlralM  ib*  putUon  or  IbepMicrtorcailcf  (lie 
■flia«l  HMire. 

m.  m. 


Fr-Ll 


lOii> 


»A 


Tf  L 
TBS  Hboal  SumTAOi  of  nn  Rnun  Cuekkii.  ducnriiKiii  or  His  dk  Ovtum.  ni  iLuwraiis 

Tat  CUKTICIL  Amku. 
TbavBualwwuuviIiowoonticclnl  with  the  iDomnmliof  Ik*  IcC  ftod  with  thcKMia  fif  righl 
a*d  hhU.  n.  L.  am  IkMiM  polo  ofUie  boioliplioni ;  Oe  t,  ibaocM(«ul  polv;  ft  L.  ilic  wot. 
pMkI  id(c:  Ch  /,  iIm  aUkM»«i4iitiiBl  taam  nfantlni  Iba  musln>l  sjnu •Idt«  D'Om  tiw tcynu 
fcwiWWt  l*law :  Cf.  naifet  lb*  iltiiallnD  of  Ibe  omukI  llBar*.  ili«  Omits  li>«lf  not  Wag  aiiiMRiii 
ealfeaBMtlaiicMaf  lb«bml>iAian.  Tb«niiiiiBfaIlamiauida«*Blerto(eoanl«nii«««Maii 
taatmrnMau. 


?2*  THE    BRAIN'. 

its  I-r*  T  ImpairTB*EiL  H  w  •■■vn  for  us  to  niopoae  that  the  lerioo  itoelf  ««> 
r«ir rorsr*.  »c-i  '■fis.t  »i'e  tfc*  «ire  of  the  m&Iady  the  cortical  area  r^inai 
hi  n-«Ea!  ocii'-.o.  *~*a  cEw  other  hand,  where  the  diseftf«  contiuupB,  the 
ivrmioencT  .  f  :s^  \.m  -4  anr  novemeflt  may  be  attributed  to  the  disax 
d'icz  T.ire  t'ras  rr-rr^r  H»r«fHi  the  function  of  the  cortical  area.  Aphasia, 
tst'T'.ial'r  ia  T'«:dj  r^mc*.  ha?  been  followed  by  recovery,  but  in  such 
ra**^  i;  fca*  befo  "rrr.-e*'!  tbat  ibe  donnant  area  on  the  ri(fht  side  ha*  heen 
awaken*-!  M  ntiv;:T  m  ibe  !•■*»  of  the  left  area ;  and  in  support  of  this 
Titw  oa^ee  have  ^**n  fW»->pi<d  in  which  a  firet  aphasia,  due  to  a  lesion  on 
the  \ih  ^de.  hs^  hreri  f'-illow^nl  bv  a  second  aphasia  due  to  a  sequent  legion 
fptxurrinz  ■■n  tbe  ri^bt  si.le.  On  the  whole,  perhaps,  the  evidence  of  clinia! 
»ludv  tecd<  '■-'  fb>''w  chat  in  man  the  Ion  of  movement  due  tn  the  destniclioo 
bv  -lijeafe  <->f  an  area  is  a  permanent  one,  though  actual  demonstration  of 
lhi#  i*  waufin^. 

^  S6L  We  mav  n->w  retom  lo  the  discussion  of  the  qnestinn.  What  ia  lli« 
rart  plaveil  bv  a  m.»tnr  area,  and  bv  the  contribution  from  that  area  to  tHe 
piran^idal  tract  in  carryinz  out  the  movements  with  which  the  area  isaao- 
ciaieil? 

We  mar  premL>e  ibai  ihe  evidence  points  very  distinctly  to  the  roncluoinn 
that  Khatever  he  the  nature  lifihe  whole  chain  of  events  of  which  the  cortical 
area  -'eem^  to  Iv  a  s^n  of  I'enlre.  the  fibres  of  the  pyramidal  tract  serveM 
the  ''Iiannel  of  nrivewe^  which  we  must  regard  as  eSerent  id  nature.  Ii  i) 
perfectly  irue  that  in  many  case!>  at  least  the  removal  of  a  cortical  ares  hu 
le<l  io  diminl-'heil  vendibility  of  the  part  iu  which  movements  are  excited  br 
stimulation  of  the  ar^a:  and  there  are  many  facts,  of  which  we  shall  pre*- 
enilv  qu'Me  a  very  ^rikintr  one,  which  go  to  show  that  the  cortex  of  tlie 
m-ifir  Tvjiivn  i*  larselv  intluenccil  bv  sensory  impulses  from  various  parts  "f 
ihe  K»lv;  but  we  i-annot  suppose  that  the  pyramidal  tract  is  the  chsnM! 
liv  «hioh  siii'h  *en*-'ry  impuli=es  reach  the  cortex.  As  we  have  previotislr 
a  -'>6:l  ur^e<l.  the  fact  that  the  defieneration  of  the  fibres  in  the  tract  iii 
des^vnitin^  one.  cannot  be  trusted  bv  itself  to  prove  that  the  direction  in 
which  the  tibrwj  carrv  impulses  is  only  that  from  the  cortex  downward;  but 
this  adiieil  i.i  the  tact  that  when  the  fibres  of  the  tract  are  stimulated  at  mi 
psrt  111'  thfir  iiiur*e.  movements,  the  siffns  of  the  occurrence  of  eSerent  eva- 
tril'u!:al  impttlfv^,  are  produced,  leaves  no  doubt  that  the  tract  is  one  nf 
efferent  libre*.  Hence  we  may  infer  that  whatever  be  the  nature  of  the 
events  tskini;  place  in  a  motor  area  during  the  carrying  out  of  a  movemenl. 
the  ]wrt  (ilaveil  by  the  fibres  of  the  pyramidal  tract  is  that  of  carrying 
eflen'nt  inipiilj*^  from  the  area  to  the  muscles  concerned. 

Let  us  con'^iiler  tirsi  the  movements  of  speech  in  man,  the  evidence  tonch- 
ing  the  connection  of  which  with  an  area  nn  the  third  frontal  convotutinn 
a|i|>ear;  lui  verv  clenr.  ^^|>eech  is  eminently  a  "skilled"  movement;  it 
involves  the  ni<>st  delicate  coi'rdinatioD  of  several  muscular  con  tractiMU.  anil 
we  m:iv  ivrtainlv  sav  of  it  that  it  has  to  be  "  learned."  The  whole  chain  of 
oo<inlin:Ued  events  bv  which  the  utterance  of  a  sentence,  a  word,  or  any 
yncal  sisrn  is  aixiimplishei!  consists  of  many  links,  the  breaking  of  any  of 
whiili  nrll  lead  to  failure  of  one  kind  or  another  in  the  act.  Something  maT 
go  wrouir  in  the  glossal  or  other  muscles,  in  the  nerve  endings  in  th(»e 
nuiiscles.  or  in  the  fibres  of  the  nerves,  hypoglossal  and  others,  between  the 
centml  nervous  system  nud  ibe  muscles,  or  something  may  go  wrong  in  that 
part  of  the  eenlral  nervous  system,  the  bulb  to  wit,  iu  which  a  certain  amount 
of  coiirilinatiun  is  carried  out  just  previous  to  the  issue  of  the  motor  impulse. 
Paniiige  done  to  any  of  these  parts  of  the  mechanism  may  lead  to  duiubnes 
or  ii>  imperfect  sjieech.  In  the  latter  case  the  imperfections  have  a  certain 
character ;  if  we  are  at  all  able  to  gather  the  wish  of  the  speaker,  we  recog- 


627 


ittf  thnt  Ke  »  Bll^mpliiic  m  inter  r)i«  rii:)il  norHn  in  t)i«  rifiht  R«<|iiciiro,  hut 
tliitt  his  rflbrts  are  frtwf  ral<^i)  hy  imporfcct  cniirdiitfltioii  "r  imtwrrcd  nni^ciiliir 
■etiao :  hit  flpech  ii  "  rbirk,"  the  B^llablM  ik  hlnrred  mtd  the  like.  On- 
w  of  the  bulb  at  times  WaAa  lo  iinpert^  apecx'h  of  thia  kind  in  whirh  thr 
p«ri«clinn  may  ho  r^cofiiiiEeiJ  as  due  tn  Ow  luck  of  proper  co^^rtli nation  of 
Enninr  imptilwa.  The  alfeetton  of  speech  known  aa"apliaBia,"  which  is  ca  need 
Ihr  Iwioni  oflhe  cf-rtex.  is  ofa  difli-reot  Hiaracler,  ami  the  furmH  of  imperft^ct 
'^Speech  caused  hy  bulbar  diwaite  huve  juMlv  been  di»i  intuit  lied  f^>n)  (rue 
aphakia  by  the  uoe  of  oilier  ternii.  Csm*  uf  complete  aphaiis  in  which  all 
power  of  speech  in  li>«t.  do  little  more  thRO  help  us  lo  ar(<erlain  the  to)x>- 
graphical  pnsiimn  in  the  corlex  of  ihe  "speech"  an-H,  hut  cosee  of  fmrlial 
■pbsrla  are  e^|)ec-iiillr  iuMruHive.  Without  ntiempliiii;  to  ^>  into  the  details 
of  the  Biihjrri  and  inin  the   ninny  c<iii:<idrr«ti<in><  which   have  to  be  had  in 

I  mind  ill  (Wlinfi  niih  it.  for  tberu  are  difrcnnl  kind*  <if  aphoiin.  we  may  ren- 
lure  to  Niy  that  the  *irikii>jt  friiturv  of  jiarlinl  aphaxia  in  thi>  failure  lo  sar 
certain  «oril>i  or  orllnhlr*.  and  the  tendency  to  riilwtiliitc  *omo  wrnnu  woril 
or  *yllnl>h-  for  ih*-  ri{;hl  une.  The  words  nr  sylhihli>»  nhich  are  iiilered  are 
Hchilv  fninnuMCi'd  iviihoiit  deftrt  nf  articulation;  and  iu  many  raw*. 
ttiou|fh  the  Hf;ht  woril  rnnnnt  be  pnHluccd  nr  i>  direct  cRorl  of  the  nill,  it 
Inay  he  utlrrt-il  under  thi-  inHiicncf  of  nn  cnioiion,  or  indcc<l  M>melimc«  aa 
ibc  n'»ull  of  »"nic  jwrcbiml  procrwun  more  cnniplcx  than  lh(i*n  involvcrl  in 
lbs  nif-rc  volitional  i-tToM  to  i<ftv  ihr  uord,  An  inslruclive  cii*e  i»  rcfvirtled 
of  m  mau  nuflriintr  fmrn  vli^'ht  nphaxin.  who  after  Mvcra)  failum  to  any  llie 
word  "  no"  by  ilwlf.  nl  laxt  Hitd.  "  I  cnn'l  «iy  no.  rir," 

From  the  phrnnmeoa  of  jinnial  npha^in  we  may  draw  the  deduction  that 
the  corlirat  upcech  area  does  not  carry  out  the  whole  nf  the  coftrdinalion  of 
Ihe  iinjtiiW*  iiivoh-cd  iti  nrltntlalion.  Thnt  co'^rdiDation  is  exceo<lini;ly  com* 
ptex.  kikI  ue  oupht  (ifrhaps  to  recof^iiie  in  it  more  than  one  decree  or  kind 
of  ciinrdinalion.  The  laiture  of  articulation  in  disease  of  the  buln  show^  that 
•  certain  amount  of  cmi'rdinaliou  lakes  place  ibere;  for  the  affection*  of 
qiccch  due  to  biiltmr  dieea»e  are  not  ibe  »ame  as  those  reetdlinir  frr>ni  ihe 
intf*  loss  of  this  or  that  muscle  or  nerve.  We  munt.  of  rouree.  admit  that 
■nme,  poanbly  a  creat  deal,  of  co'kdination  of  n  certain  kind  take«  place  in 
the  cortex,  for  the  bulb  cannot  by  itielf  be  made  to  fiiteak  ;  exactly  how 
inuch.  the  knowlcdj-o  at  |>r(«ent  at  our  disptwal  leaves  a  matter  of  threat 
VDcertainty ;  but  it  in  itiijiicienL  for  our  present  purpoae  to  reco^iao  that 
whatever  may  be  ibe  nature  of  the  eventH  takiuK  place  in  tlie  cortical  arvm 
durioff  tbe  act  of  Bix^ech.  those  events  make  u^  of  ibe  machinery  already 
proviiled  in  the  hulb.     ^^le  word  iipokeii  doe*  not  stort.  mi  lo  speak,  ready 

Itmide  in  the  oiriex  ;  it  is  not  that  a  f;roup  of  impulMs  atart  fKini  ibe  cortex 
with  their  coordination  fully  achieved,  and  pass  aloiitc  certain  ncn'e  fibres  M 
certain  muscles,  making  their  way  without  rhunire  ihrtiuffh  the  lantcl^  of  the 
bulb,  as  if  this  were  merely  n  bundle  of  linen  oflerin);  pathn  for.  but  exercis- 
ioK  no  influence  over  the  impulaeH.  We  miiM  rather  anppoae  ibal  Bome*biDfc 
lakes  place  ia  the  cortex  of  the  third  fttm.lal  convolutiua,  aa  the  result  of 
which  eflerent  impiiUea  paaa  alo»j{  the  appropriate  fibm  of  tbe  pyramidal 
tract  lo  the  bulb,  ami  there  »tart  a  series  of  evenla  leading  to  the  i«>>ue  of  the 

Ordinatod  inipidi>ra  hy  wliicb  the  word  in  *p»kc]i. 

(668.  We  have  uu  n-ajHin  ulialL-ver  to  think  that  llic  cortical  area  for 
speech  dillbrx  in  il*  fuuiltitiii-nlal  ohamcterw  from  other  didikwa  of  the  motor 
legion,  and  an-  Jij>lifii.-<l  in  carrrinR  on  to  other  ari-aM  tbe  deduction  we  have 
JnH  dnwD  in  ninncc-tion  with  the  (pt-rch  iin-a.  With  that  end  In  view  ne 
nav  now  turn  back  to  the  expcrinwnlal  multn  olitaiucil  on  the  do|>,  and  tt 
will  niakr  our  dltciitninu  iiiniplcT  if  we  lake  aa  an  illustration  Mine  large  area 
such  a»  the  lore  limb  aren. 


8S8 


THB  BBAIS. 


We  have  wen  that  Mimulntion  of  lliij)  urtA  pruduoe*  what  ire  msf.  to  Btart 
with.  »|)eiik  of  •implj'  im  roovemrnt*  of  the  fore-limb:  ami  gtiMed  by 
nnalutcv  of  Mf>eech  in  mtiD  we  mnv  confiHvntlr  conclixlc  ihni  wlien  the  i\of 
volunliirilx  mnrvw  iho  foro-limb,  tlic  net  u  cnrriMi  out  ttv  ni«Hiu  u(  event* 
tiikint!  pliicc  ill  ihc  fon-linil>  cortical  iir«&.  The  fimjilicily  "f  the  ekctri- 
cal  pfaenomeiin  i-fsiillins  from  cartiual  slim  illation,  which  vrr  dti«(-rib«d  in 
9  658,  Diigbt  at  lirst  si^nt  lend  ui  to  coiirliiilc  thai  the  wlmk-  lumber  wv 
fiiirly  mmple ;  anti  tndcciJ  sum«  wrilcre  ni>prar  to  vntortain  lliP  oooorptiM 
that  in  a  voluntary  niovcmriil  Kuch  as  that  of  the  foro-lirab,  nil  that 
Inki^  ptacu  is  that  the  "will"  itimiilatM  corlnin  cclU  in  thn  oortieol  mm 
cnii*inglhe<]ischar^of  nxilor  impiileea  along  the  pyramidal  fihraa  onDMVtn] 
with  ibufir  ccIIb,  and  that  th^se  molnr  impulses  tnvel  strsif;ht  d'>irn  llit 
|tyrnmidnl  Irnct  to  the  motor  libras  of  the  appropriate  nerves,  undrrcoiag 
powihiy  »nmc  cban^K  at  the  place  in  the  cord  where  the  pyramidal  tibn 
make*  iimction  with  ihe  fibre  of  tlie  anterior  rout,  but  deriving  their  chi>^f  if 
not  their  whole  co'^rdioation  from  the  cortex  itself,  that  is  to  say,  bdng  eoOr- 
ilinated  at  their  very  startin;;-poiut.  That  such  a  view  is  nnlenablv,  nsd 
thai  the  simplicity  of  the  electrical  pheDomena  is  miilendiu^;  is  shown  by  llu 
(■illowint;  two  oonsideratioiu  amonj;  others:  Ou  the  one  band,  as  was  sbnoa 
in  a  prei-iods  eeclion.  the  co4'>rdi nation  of  movemeate  may  be  carrtMl  out  ajiatl 
from  the  cortex,  namely,  in  the  absence  of  the  lieniisplieTes ;  and  we  caa 
hardly  suppose  that  there  should  be  two  (|iiite  disliocl  systenu  of  oo-'krdin- 
tion  to  carry  out  the  aaroe  moveoieut,  one  employed  when  volition  was  the 
tnovinR  cause,  and  the  other  when  aometliin^  else  led  to  the  nM>venient.  Un 
the  other  hand,  the  analogy  of  speech  justilitM  us  in  conoludinf;  that  the  cor- 
tical prnoeme«  <lo  take  advantage  of  a  ooonlinatiuo  effected  by  the  aclwia  of 
other  parta  of  the  nervmi*  nyslern. 

Hearing  thid  in  niiiid,  we  riiav  recall  attention  to  the  remarkable  effv^l* 
which  result  from  the  rcniovnl  of  iho  area.  Thefc  arc  twofohl.  In  the  Hni 
plave,  there  Is  more  or  1cm  cixnpli'tti  paralysis  of  the  limb;  all  the  mor*- 
menu  of  tbv  limb  are  f  jr  n  time  ineHcciive.  It  »  not  that  purely  voluntary 
movemenis  are  alone,  so  to  speak,  cut  out.  the  relli-x  and  other  moveMeau 
arc  a\m  impair<'4  or  lemporarily  abolished,  and,  as  wo  havu  almidy  sai<t,  ia 
manv  cases  at  lni»t  the  sensations  of  the  limb  are  interfcrxvl  with.  Thev 
tro(ible«  are  of  cmirso  in  part  tho  oflects  of  the  more  ooerttive  interferroa 
belonging  to  what  we  spoke  of  in  $  h6'i.  as  being  of  the  nature  of  shook. 
But.  even  giving  full  weight  to  thL<  consideration,  there  remains  the  llsi-t  tbil 
the  cortical  area  u  aatociated  with  the  various  coordinating  and  other  am- 
Tous  inwhani^ins  balooging  10  the  limb  by  such  dote  tie*  tfaat  these  art 
thrown  into  diiorder  when  it  is  injured.  And  side  by  side  with  this  we  may 
put  the  remarkable  fact  previoniily  sialyl,  thut  during  an  abnormal  oonditiuD 
of  the  cortical  area  Bti mutation  of  the  area,  instead  of  producing  the  appn^ 
prifite  movementa  confined  to  the  limb,  may  give  rise  to  niovcmeuta  of  oibtf 
parts  ciilmtnaliii);  in  epileptiform  GonvulMuiU. 

Ill  the  Hrcoud  place,  ihit  paralysis  ia  temporary  only,  tlie  voluntary  mcft- 
menu  are  after  a  while  regaiiied,  ami  that  in  spite  of  the  fore-liub  moiety  of 
the  pyramidal  traei  pcniiauentlv  degenerating  alon^  its  whole  lenf[th,  oaxket 
it  nor  the  cortical  area  ever  being  itgeneratiM.  This  shows  that  whatever 
be  the  chain  of  eventa  in  the  intact  animal,  it  ia  jMesible  for  the  "  will "  of 
the  animal  to  get  at  ilie  musclca  and  motor  meehaniams  of  the  fere-limb  br 
some  other  path  ihaii  ihnt  provided  by  the  appropriate  cortical  area  and 
oorreapoiiding  |mtliof  the  pyramidal  tract;  and  ibeMcts  previous! v  recufdvd 
(S  659)  ahow  that  that  other  part  ia  nut  the  correip  mdin/  part  nf  the  pyn* 
midal  aystem  belouging  to  thti  other  half  of  the  heini«|iiiur«,  an<l  inilM-d  it 
not  any  part  at  all  of  the  whole  pyramidal  system.     The  '•  will."  whatwi'T 


I 


ibe  proccMM  hy  which  it  tiikt^  origin,  am)  nlxervver  b«  the  pl<w  vrhcrr 
ih^TBrv  carried  vii.U  nlik  in  thcitWncvof  the  pyramidal  i^stem,  to  {iruduoe 
il*  •flbet  on  tho  inotvr  Gbm  of  the  brnchinl  nerves  !>/  working  on  oLh«r  |mh1b 
of  th«  CBDtrml  itcnroiis  FVEtcni. 

Ht-iict'  whilo  fldmiliin^,  m  wc  miiH  do,  thnt  in  tli«  intnct  nnimni  the  cor- 
licul  nrcu  and  |>ymmidnl  tract  piny  tbcir  pnrt  in  cxrrviiig  oni  volunlnry 
noTemfiitB,  th^-ir  action  i«  »oi  of  that  »iinp)c  chnmck-r  fiippuvcd  by  lh«  view 
rrfprml  to  nbov«.  Od  tlio  conirnn',  we  mro  drivQO  to  regard  iheni  ralher  ib 
linke.  in)|N)rlnnt  link»,  it  is  true,  but  flill  links  in  a  complex  chain.  A»  n-v 
have  already  orged,  we  may  prolwbly  speak  of  ihe  changes  taking  place  in 
th«  pyraiDidal  fibres  n«  being  in  the  whole  of  the  natiirv  of  efferent  itDpulsea; 
but  we  thould  be  going  beyond  (he  evidence  if  we  concluded  that  ihey 
Here  idetilical  with  the  ordinary  efferent  impulses  of  motor  nerves.  And 
above  all  it  must  not  be  left  unnoliced  that  the  corlicnl  area  has  close,  if  not 
direct,  oonnecliom  of  a  sensory  nature  nilh  the  part  in  whose  movements  it 
b  concerned.  This  is  (hown  by  the  foMowiog  remarkable  results  whieh  may 
Drake  iheir  appearauce  when  Mimulalion  of  llie  cortex  is  carried  nhile  the 
aniioal  (ihrgr  is  in  a  particular  stage  of  the  intlueiiL'e  of  morphine.  If  a  aiib- 
luiiiinial  blimulus  be  found,  that  in,  a  current  of  such  iulciisity  that  applied 
to  a  mulor  area  it  n  ill  produce  no  movement,  but  if  increased  ever  so  slijchlly 
will  give  a  feeble  contraction  of  the  appropriate  miipclcs.  it  may  he  observed 
that  a  dU^hl  stiiuolue,  sucb  as  gently  strokine  the  skin  over  the  muscles  in 
(fiwfltinD.  uill  reiKJer  the  previous  submiuimul  slimtilua  elleelive,  and  so  call 
liirth  a  ntovemenl.  Thii^  if  the  area  experimented  on  he  that  connected 
with  the  liDiug  of  the  forepaw,  and  the  euhminiaial  stimulus  be  applied  to 
the  area  at  interval*,  after  several  applications  followed  by  no  moTumeuta,  a 

fentle  stroke  or  two  over  the  skiu  of  the  paw  wilt  lead  to  the  paw  being 
d1»l  the  iwxl  lime  the  mininlnf  U  a|iplic<]  to  the  area.  A  umilar  rt«uli, 
hut  l«ai  sure  and  vtrikin);,  may  follow  ujion  the  Mimulntion  of  pnrlM  of  the 
body  other  ibsn  Ihv  |mrt  ■'ornvpfiiiding  to  thi-  arm  stimulated.  Then,  nirain, 
it  haf  Iwcn  ol>>crviH)  ihnt  in  M-rtain  other  xlagcs  of  the  influence  of  mnrpninc, 
ihr  cimei  anil  the  r<»l  of  thn  ncrvoun  system  are  in  »uch  a  condition  l)uit 
th«  npplicniion  of  even  a  momentary  ttimuliM  to  au  am  leads  nut  to  a 
•tniplt;  movement,  hut  to  a  long -continued  (ooic  contraction  of  the  appixi- 
priaii*  miMclea.  Under  Ihcec  nr<-unift«ni-n  a  gentle  stiroultiiF,  fucU  ns  strok* 
ing  the  skin  or  blowing  on  the  face,  applied  immedintelynller  the  application 
»f  i1m<  electric  stimulus  to  the  area,  snddrnly  cuis  nhort  the  contraction,  and 
brings  the  muscles  at  onco  to  rest  and  normal  Haccidiiy. 

Tbcfc  expcriractitfl  abow  that  the  development  of  the  procc8>«s  in  the 
conrs  kiiiling  to  the  mne  of  whut  we  have  agreed  to  chII  efferent  impulses 
along  the  pyramidal  l)bn.-8  i«  markedly  nH<?cled  by  sensory  impulses,  and 
specialty  by  sensory  impulses  starleii  in  liie  tkin  overlying  anil  correspnnding 
to  tliv  mosaes  put  into  movement.  How  those  sensory  impulses  reach  the 
cortex  we  do  not  exactly  know;  but  ne  have  no  evidence  In  show  Uiat 
aflerent,  centripetal  impulses  can  travel  backward,  to  to  speak,  along  the 
pyramidal  fibres ;  and  it  is  more  reasonable  to  suppocie  thai  the  senior}'  im- 
IioIms  in  question  reach  the  cortex  by  the  ordinary  paths  of  sensory  impulses, 
which  we  sliall  presently  discusa.  We  may  therefore  take  tbe  results  of  llie 
ex(>enmenls  as  sliowing  how  close  is  the  c^jnneciion  of  the  motor  area  with 
Uie  sensory  inechaDisDM  of  the  spinal  cord  and  lower  parts  of  the  brain,  and 
as  illustraliDS  the  oooiplexity  of  the  chain  of  cvenis  by  which  tbe  motor 
area  brinirs  about  voluntary  uoTementa. 

ji  663.  We  hii\  e  alKive  used  the  fenentl  phrase  "  movenienia  of  the  limb," 
since  in  the  ilnji  it  h  not  ttwy  In  pick  >Hit  cerlain  movements  a*  lieing  pnrlicu* 
Inrly  skilled  movoiin-nln.  In  the  monkey  such  a  divtinctiou  i*  easier.  In  this 
auimal,  aswe  luiw  mid,  recovery  of  voluntary  mvvetueot  also  ukrs  place 


I 


830 


TnS   BRAIX. 


nlier  reoiuvul  of  a  corticnl  area,  or  at  least  lias  dune  so  in  many  laisei ;  aud 
white  tbe  j>heuuui«uii  iu)m«iliaiely  lulluwiu)*  removal  uti  iti«  whulv  twembl* 
tbuw  iriin<*ie<l  in  tbe  dog,  a  certain  order  oC  recovery  may  be  observed  :  lii) 
more  akill«<l  iiKiveiiieiiin  are  ibe  btit  u>  return.  When,  fiir  iuataaoe,  tbe  aru 
»tt»  in  remuved.  tlie  delicate  movemeiits  of  tbe  hand,  uf  tbe  tbuub  uai 
liu^r,  are  the  lust  to  be  reratablitilied :  and  u  uuudiiioo  of  Ibin)^  nuy  k 
met  with  io  wbidi  tbe  atiiiiml  aAer  removal,  say  ul'  tlie  arm  are*  id  ilie  Itlk 
Itembpfaere,  Uf«B  by  preference  the  lelt  biuul  at  a  time  wbeu,  if  [mwaiiJ 
tViMU  ueiing  tbut  baud,  he  m  able  to  ane  llie  ri^lit;  tlmt  U  to  !»y,  the  raouvgry 
iu  tbe  riichl  limb  alter  the  removal  of  tbe  area  on  tbo  ivii  aide  it  ituarly  tna 
nut  (juiie  coiupleie;  tbe  "  will  "  can  j^ain  aooan  l»  tbe  ri)(bl  baud,  but  lui 
ao  caaily  an  to  ilic  Ml  band,  nud  tbitt  latter  i«  UNcd,  tliou^li  under  ordinary 
cireuiu*iauo»  it  would  nut  be  uMcd. 

When  we  turn  to  niiiii,  in  wliuni  the  great  (luvclojtinvut  of  the  iiyraraiiU 
ayileui  and  dillereotiultnii  nC  tlie  curiiciil  ami  is  |i«irallelwl  by  tlio  (irvnt- 
notice  of  tkilJcd  and  trainol  movements,  thfl  MiBlaffy  of  the  i>UpnoDMU<>r 
•pe«vh,  if  it  be  true.  ii»  cliiii<'iil  bioiories  accid  to  abow,  that  di«iructioa  bf 
tliaeaie  of  the  *|ire(rh  area  of  both  «id««  causes  [>«rniHne4)t  aphakia,  woulil 
lead  ua  to  oiuii'luile  tliul  n(  IrJint  highly  ekilM  vuluntAry  moveoMnU  ai* 
carried  uut  by  the  pyrnuiidiil  vysLi-m  and  by  that  alone.  But  in  nfervnm  (u 
thia  it  must  he  romombervd  iliut  xiich  a  perranuMit  aitliaeta  may  ba  dtia.  w* 
to  mere  lou  of  the  pynimidal  chiiniivt.  not  to  llie  will  b«ii>g  merely  nnaU* 
to  gain  aoc«M  to  lower  coiinlinatiug  itii-cliauUinB,  but  lo  the  abMDce  of  tlw 
diHJwtditiaicd  cortical  gray  matter,  by  rnuon  uf  which  absence  the  will  cnno'it 
initiate  the  fintt  procvsMa  «(  the  ncl  of  it|<eech  ;  it  may  Iw  that  were  it  abit 
to  do  M),  the  pru(W»es  to  started  niijiht,  in  I  Ite  nlwcncv  of  the  pymtaJdal  tntd, 
lind  some  other  way  to  the  bullmr  nu-chnnism,  ns  in  ihc  caau  of  the  ittiskilM 
moTements  of  the  dog.  This  [loinl,  however,  clinical  biuorieft  have  not 
definitely  tettted.  Moreover,  io  dc^in^  with  the  phenomeoa  of  the  nervoet 
system  uf  oiau,  as  revealed  by  diAea^e,  we  meet  in  relereiice  to  tbe  oanlnal 
cortex  the  same  dilHi.-uUy  ilial  we  dwelt  upon  iu  dealing  with  the  dpinal  eonl 
(§o!f2).  Lesions  of  the  pyruuiidal  sysiem.  of  the  InlemaU-ajKiule  for  JustaiWR 
leail  ti)  Ihe  loiis  not  only  of  skilled,  but  of  all  volutilary  movements  ;  aceort- 
lag  to  ihe  character  and  jMaitiuQ  of  the  Imioti  tbi>  or  that  jMirt  of  tbe  bod; 
is  wholly  withdrawn  from  the  iutlui^nc-e  of  ihe  will.  Ami  it  t*  pOaaiUe  Iv 
inaintaiu  the  thetiid  that  muo  lius  l>eco(iie  no  <leveIop>:d  ua  to  his  nvrvoo*  tjt- 
turn  and  the  motor  oiirtex,  so  aci-ii>tomcd  Io  make  tMe  vxcUiiivcly  of  ik 
pyramidal  system,  that  the  will  haa  l-nt  ilie  [H>w«r,  mill  |»iiuvwpi|  by  Iumt 
iiniraals,  to  gain  access  by  sunie  paih  ulbur  than  the  pyniniitlnl  om<  to  tlv 
immediate  nervous  mechanism*  iif  movement.  Tbe  dnla  liir  loriuing  a  tMit 
IkcUiry  euuelusion  as  tu  tbt.^  pi>iat  are  so  few  nod  uni'crtaiu  thnt  it  would  b 
nuprufitnble  tg  discuw  the  (giK^tion  licre;  hut  we  may  v«ntnn;  to  ptiut  iiui 
that,  griuit  as  is  the  devcluptiient  of  the  cerebral  cortex  and  th<?  pyr^uii'lsl 
aysteoi  in  man,  that  development  is  aocompaaicd  by  ■  hardly  lew  slrikis; 
ezpauuoD  of  other  parts  of  thu  bnin  not  directly  OKinoctisd  with  tbe  pyra- 
midal ty*tcui  nhich  we  have  previously  seen  rauoil  to  a««iic!ale  with  iba 
ejiirdiniilion  of  iiiovumuntj).  for  ciiimpio  ihe  oerebelluin.  Ami.  indeed,  it  ii 
clear  that,  niliuitting  the  pyramidnl  tract  to  bo  the  onliiiary  chsuoel  by 
which  volitional  impui»c«  ftnta  lo,  or  by  which  the  will  gains  accees  tn,  ili< 
motor  mwhanisiiiK  immcdiiiU-ly  associated  with  the  anterior  tuols  of  tJiU  « 
that  »pinnl  nerve,  we  must  also  admit  tlial  ibom  volilioiinl  impulsed  paaiiaj 
along  the  pyrminidai  tract,  or  at  leiist  iome  of  tbe  prooeatea  ooasiiiutiuj;  tlw 
will,  are  in  connection  with,  and  thus  are  influeooed  by  the  oonditiun  i>f. 
olher  parts  of  the  braiu.  When,  fur  instance,  a  gymnast  executos  a  sklUeil 
VuluoUiry  uioveuieul  iu  which  all   bis  four  liuibs  and  other  jHirta  as  well  pnr- 


ON"    VOLl'KTARy    HOVKUENTS. 


881 


I 


I 
I 


liialxiJj'  nri-  involvol.  it  u  pnilMtlily  tlw  nM  llmt  chnngn  of  tin 
iMtiirv  or  i-HVrtiit  iMi|HiU>«  fvitvp  ilowii  hii  pyntniiilnl  inid,  and  timt  tiMH 
j»i|HilM-a.  Hlurtiiig  ill  o  (U-liiiiUi  unJcr  from  hit  corUix,  ihiil  in  Id  my.  having 
uitik-r>,'<iiiv  a  n-niiiii  uuKiuiit  of  initial  outiiinnlion  m  lli^ir  very  nngiii.  iiR-vt 
Mitli  liirthur  oonJiiikiioB  in  tbttpiiial  grtiy  Rivtlvr.  wbii-li  Mrvn  u  n  m4  uf 
iturlui  ul'  (irigii)  tur  ili«  inolor  nervM  conoerned  in  ilie  ntovcnwot  botbrv  Ihvy 
iMtiu  BR  oniiiiary  tuotur  impulses  aloii);  the  niuerii)r  nxita.  lint  tlii;'  t«  nnt 
ftU.  Sbuuhl  ihe  ;;yniiiiu>l'H  seoiicircular  ctintilH  happen  tu  be  injurvl  anil  hi< 
cerebeiliim  tbereby  bo  Iroutiletl,  or  mischief  fall  on  some  oth«r  part  uf  lh« 
drain  wliioh  like  ibia  baa  no  direct  cunDeciioa  witb  cither  Ihe  pyramidal 
Inct  or  tii«  luolur  curlpx,  Ihe  movemenl  foils  thrungb  lack  of  coordinnlion, 
thuagh  bulh  the  cortex,  the  pyramidal  tract,  and  the  spinal  motor  mechan- 
iaraa  ranaio  as  tbey  uere  belure.  Obviously,  the  carryiuK  out  of  a  voluntary 
muvement  b  a  very  complex  proceedin;;,  and  the  muiiir  ciirlex  with  llw  pfrft- 
loidiil  tract  is  only  one  part  i>f  the  whole  meclmuiam  ;  k>  tar  from  the  whol« 
bu>-iitea4  beiujf  L-»nliiu.-d  lo  tliefie,  it  is  perliajM  no  esa^^raiiuD  to  say  lluil  in 
eai.-)i  iiiuv<^u(i:iit  uf  the  kirxt  mu^t  paria  of  the  whole  hrsin  bave  a  greater  or 
lea*  abare. 

The  exact  luUure  of  the  part  playe^I  br  t)ie  cortex  and  the  pyramidal  tract 
iu  voltiuDiry  moveiDcoia  uiir  present  ko<iwle<l;,'f  n  iniKk'i^iinte  to  detini!. 
Wh'ii  We  iMua  in  review  a  wriett  uf  braiua  Irom  llie  luuur  Iu  tite  hi};her  and 
•cf  bow  ibe  pyruiiitilal  nyiil<.-iii  is,  »i>  to  npenk,  grafUd  un  to  Uie  rtst  uf  the 
Itmiti.  wWn  nf  ob-i^rve  huit  the  iiit-rea*iQg  ditferentiatioD  of  the  motor  cur- 
t«X  niiu  parallel  In  the  iucrciuiog  pOMemon  uf  skillctl  educated  muV6m«Dl», 
wc  way  ]ierha|«  flUppnet.-  lliiil  '*  A  alrart  cut "  fnnu  thi;  ourles  to  the  urtfjpria 
of  tJw  aeveral  mulur  ui^rvcs.  vucli  hh  in  aHunlcd  by  the  pynirnidal  tibn-s,  Irutn 
tbo  advantagea  it  uiren  t»  lh«  umrc  primitive  [wth  fr^ni  i>e}(dieut  tu  M^ncnieni 
aluo;;  iIm  CVNbro-spinal  axi«  baa  by  natural  selcctiun  bcien  developed  intu 
bcin^  in  man  the  cbivf  and  trn^t  important  instrument  for  carrying  out 
voluiKury  movements ;  but.  we  rcjicnt.  il  remains  even  in  itn  higheat  dsvolop* 
laent  a  link  in  a  chnin,  and  a  knuKledga  of  buw  th«  vhola  chain  worka  ia  at 
preeviil  bidden  fi\jm  ua. 

We  must  Dot  here  wander  into  psychological  prob!e>Ri«,  but  may  ropnt 
that  in  the  above  diocusiion  we  have  used  the  word  "  will  "  iu  a  genural  acoM 
unlj.  A  man  may  be  broufiht  into  a  condition,  for  instance  in  certain  byp> 
nolle  phasee,  in  which  he  can  carry  out  all  the  various  skilled  niuvomcuU 
which  Ite  has  inherited  or  which  be  bu  tearneil ;  and  yet,  ncording  tu  some 
(letiuitions  of  the  word  "  will,"  thuM  ntOVeiDeals  could  not  lie  said  to  bo  initi- 
ated by  his  will.  It  can  hanlly  be  doubted  that  in  sucb  cases  the  motor 
cortex  and  pyramidal  Itact  play  their  usual  part.  lint  we  may  pass  from 
>uoh  caaea  aa  these  ihrou^'h  others,  uniil  we  come  to  casei  where  a  skilled 
niuTemeut  which  baa  t>een  learnetl  and  praciiwd  by  the  wurkinj;  of  an  iaielU- 
^leul  will,  may  continue  lo  be  carrit'd  out  under  cirLntoutances  ifhich  seem  to 
preclude  the  intervention  of  any  ounscious  will  ut  all;  and  the  tramitiun 
Irom  tme  case  to  nuoiher  is  so  i;rad<jal.  that  it  is  impiuaible  to  (uppase  that 
there  ha*  li««n  auv  sbifiinjc  uf  tlte  macliiuery  employed  fur  cnrrying  out  tite 
noTeuenl.  8u  tnat  a  volitional  origiu  b  not  an  Mtcniial  feature  uf  tli«M 
•o-called  vuluoiary  ninvemenu,  and  the  raaohinery  of  the  motor  corl«x  and 
pyrsmtdal  trad  is  available  furiHher  ihinj^  than  pure  voliltonal  inpukaea. 

I  684.  The  ))recedia;;  dbicuation  will  enable  us  to  be  very  brief  cuncerning 
a  queatiaii  which  hai  fruiu  time  U>  linte  bcvn  much  disciuMvil,  iinil  which  hat 
acquired  |ierbii|H  ftuiiiiou*  im porta ix-e,  vii.,  llw  qucaiion  n»  la  how  voltiiunal 
impuinn*  leadm),'  Iu  volnntitry  niovrmcnta  iravvl  along  iho  i^piiud  cord.  Tlie 
oonclUMon  at  nhicb  we  linve  arrived,  nxmi^lr,  ihai  in  ihe  normal  carrying 
out  of  voluntary  movements  tliv  chief  put  ia  jilayvd  by  sdennt  imputsus 


883 


TH«   BBAIK. 


(mning  kIod);  the  pyramidal  Irart,  carries  with  it  (lie  ftoener  tint  Tolilionl 
ioipulaes  travel  id  Ihe  spioal  cord  aluiif;  tlw  pirraini<lal  tract. 

In  ibe  dot;.  ^°  which  tbe  nholc  pyramidal  tract  croeses  al  the  <leoaMBiiia 
of  the  pjrKiuida,  we  should  ex{>evi  lo  6nd  that  a  br«ak  id  the  p^TMiudil 
tract  of  uDe  aide  of  tbe  cord  al  an^r  poim  aiun^'  ita  leotflli  cauaM  lo*  tl 
voluntary  movement  on  the  saiae  «<le  below  Ibe  level  ul'  the  bremlc.  Aod 
ex|)eriu)eul8  as  far  as  they  go  support  Ihia  view.  Ho  one  it  ia  true  bti 
attempted  to  divide  or  otlierwtee  cause  a  break  in  the  pyramidal  tract  ■loar. 
leaving;  ibe  real  ul'  the  curd  intact;  and,  indeed,  even  if  an  injury  wtit 
limited  to  the  area  marked  out  as  tbe  pyruaiidal  tract,  fibres  other  tkaa 
pynimidal  Hbrnt  would  be  injured  al  the  Mme  lime,  unce  Uie  tract  b  never 
u  "  port- "  one.  But  it  hns  been  found  thiii  ■  secitun  uf  u  lateral  half  of  llw 
cord,  a  luieral  bcm'iseotion,  or  a  teciion  limited  to  the  lateral  eolumn  of  ew 
aide  baa  for  one  of  ita  priDdjial  ed'ecta  Ium  of  roluntary  raoTenieut  on  Hit 
aame  tide  in  tlie  parU  tupplied  bv  motor  nerve*  leaving  the  cord  beluw  t 
level  of  tbe  set-tiuu.  Wc  my  "  one  of  it*  ]>Tindp(il  eBcoU"  because,  \r^' 
the  coucomitaiit  inicrrereticv  with  MiiitnlioDS  coucerDtDs  wbidi  we  shall  i  _ 
jirtvciitly,  the  Ium  uf  voluntary  ■aovcnient  i*  not  nbsututely  confined  lo  ibt 
same  side ;  tbera  is  some  lo«  oi  |>ower  on  the  croand  side,  at  least  in  a  large 
number  of  casct.  Wo  mutt  not  lay  alrea  on  thia  croMe<)  parnlyvia  bcotim 
it  is  probably  one  of  the  cibcta  of  ibo  nitre  operation,  not  a  iwre  "Ml- 
ciency  "  phenomenon,  and,  indeed,  appcan  soon  to  poaa  aw«y.  But  laking 
into  consideration  what  was  nid  ahovi;  conoorning  Ihe  cflVvts  of  rentiirlu 
conical  arcuK,  it  is  imjKtrtnnt  to  note  thai  in  ihc  experi*nce  of  many  rxpov 
lucuK-n  th<:  low  of  voluniiiry  |H>w<ir  on  tbe  opomled  lido  dimloialies  alter  a 
while,  nml  Ihtit  the  niiimni  if  kept  alive  and  In  good  htalth  long  enouli 
appeara  to  regain  nlRioel  full  voluiilnry  power  over  tbo  aflcctcd  p«rt&  In 
such  oaaee,  ss  m  other  operaliona  on  thu  i;eDtral  nervous  •ystem,  there  it  aa 
regeueratiuu  of  nervoua  tissue ;  the  two  surfaces  of  ibe  section  unite  by  «» 
■Mclive  uoi  nervous  tissue,  and  tbe  Iracts  which  as  tbe  result  of  tbe  ie«lica 
degenerate  downward  or  upward  arc  permaueully  lost,  lleooe  even  if  «c 
admit  that  in  the  inlact  animal  a  voluuiary  tiiuvement  is  chieHy  carried  enl 
by  means  of  eHerenl  impulses  passio);  along  tbe  pyramidal  trail  riKht  don 
to  the  motor  niechaDisms  of  the  conl  inimediately  conuccii^  with  tlie  moMr 
uervea,  we  must  also  admit  that  the  "  will "  under  cbau(,tMl  drnitnstauctt 
can  find  other  channels  for  gainin)c  acoew  to  the  same  meehaniaais, 

II  lias  been  further  obferve<l  that  if  in  the  dog  a  bemiaeciion  tw  made  u 
one  level,  for  instance  in  the  loner  ihorncic  re);ioD  of  ibe  cord,  and  thai, 
alter  wailing  until  tbe  voluntary  power  over  tbe  hind-limb  of  that  side  hat 
returned,  a  secuud  bemiseviion.  this  lime  on  the  other  aide,  lie  made  at  a 
higher  lavcl,  this  second  ogHTuLinn  is  followed  by  resolla  similar  lo  ihowof 
the  6nit ;  there  is  loni  of  v»lijntnry  jxiwcr  on  the  *i<le  o[ierate«l  oo,  with  Mm 
lota  of  jiowLT  i>n  lh(!  crcKuml  sidr,  niid  as  in  the  lint  case  thia  lata  of  power 
not  odily  mi  the  saniu  but  also  i.m  Ihc  cro«H.il  ride  ntay  eveiilunlly  dtmpptar. 
This  kluiws  among  other  things  thnl  the  recovery  after  tlic  lint  u|ieration  wai 
not  duR  to  the  n^nmining  pyramidal  tract  doing  tbe  work  of  both,  Purtlm, 
the  hcmi-ii-cttou  may  he  repcaierl  ii  third  tiuK-,  the  third  Itcmisectioo  bs^ng  OD 
Ihe  same  side  as  thv  fint,  with  at  least  very  uoiisitlvrablc  retnru  of  ponr 
over  htilh  limbs.  That  is  to  say,  under  auch  abnornml  circumstancce  volun- 
tary impuUrs  may,  so  lo  speak,  thread  their  way  in  a  ligiag  manner  fntBi 
side  to  nilc  along  the  mutilated  cord  until  ihey  reach  tbo  appropriate  spioa] 
motor  mechanisms,  ^^uch  an  abnormal  nale  of  things  docs  nut.  hovever, 
really  militate  against  tlie  view  that  under  normal  circumstaocM  rolitioaal 
impuJsGt  normally  travel  along  the  pyramidal  tract ;  but  it  does  show,  what, 
indeed,  has  already  been  shown  by  tiie  phenomena  of  strychnine  poisoning. 


flH    VOLL'.NTAUY    MUVIIUKNTD. 


S8S 


» 


I 


S  5S7,  Uuu  in  llifi  central  norvoiis  ■yKtfRi  tlic  [taMii|;i;  of  nervoiH  inipulnM 
luttOfT  Ume  nords  in  the  p?nGml  fwnac  if  chaiigv*  p^rlpng1ll■^l  nlong  Dervuu* 
inal«fialj  ia  not  rigidiv  and  unsll«rably  lixpH  l>y  thp  ntiatomiml  dislrilmtion 
uf  traoU  of  fibrw:  in  ill  such  drK'iiMiniti  a*  ihow  in  whicb  we  are  etijfnMd 
we  mutt  bear  in  luind  tliat  pbyttiuli'tfitnl  (i>iidili'>nH  w  well  as  aiuatiiinical 
eootinuilf  ar«  puient  in  deli>rmitiiii>;  tbe  [inatiige  i>r  itieie  impuUiw. 

$  665.  Wlieu  we  reflect  on  the  fcreai  prominunwuf  the  pyrumidal  irm-i  in 
tht'  !i|>innl  ronl  nl  man  aa  compared  with  that  uf  ibe  du^.  "'^  nuir  jii>lly  inter 
not  only  ihni  tbe  t'Vruniidal  iraet  is  nnder  normal  eiri-'u instance*  more  exclu- 
tivoly  ilif.  I'hanni^l  id'  volitioniil  iiupiil&ca  in  man  ihan  in  audi  lower  aniinitk. 
but  iiliMi,  iM-iirin^  in  mind  (he  dinL-iiMJoo  in  n  previiuii  eliuptcr,  $  51*2,  con- 
oeming  tlic  uctivitiM  of  Uic  tipiaal  oml  of  niao,  thni  the  )K>uuitinl  iiltcrna- 
tivM  pmMiml  by  iIm  xpinnl  cord  of  ih^  do);  are  (crvally  reduced  in  that  of 
DiKO.  And  »uch  clinical  lunlorM  of  iliaeaite  nr  avetdeiitat  iojnry  in  man  as 
W«  iMMMMMipporl  Ihitt  cfinclintinu.  Lenions  i-oulincil  to  i>ne-hajrr>l'  tbe  cort), 
or  erini  Inton*  confined  to  tbc  Inicrvl  column  of  one -hair,  a[tmutr  to  lead  to 
IcMi  of  viiluntnrr  piiwt'r  on  the  «nme  ilile,  and  rlut  irainc  tide  only,  in  the  parts 
below  thi'  Icvrl  of  the  lr»iim  ;  ami  the  naint-  Hvinpfxn*  bare  been  observed  to 
accompany  diaeaie  limited  apparently  Ui  the  pyrnmidnl  Iriicl  of  one  side. 
Mureorer,  thougb  com*  of  recovery-  <if  power  have  beat  recorde<),  ne  iiare 
aot  Mob  Mtisfactory  cvi<teiK«  as  in  aniinalx  of  the  volitional  impulses  ulti- 
mately making  ihcir  way  along  an  alt>Tnaiiv<'  route;  hut  here  tbe  sBnie 
doubu  may  be  euterlaint^d  as  were  esprcswd  in  disL-nMiiiK  the  reflex  acts  of 
the  ronj  in  man. 

When  we  nay  that  the  Inm  of  Tolnntary  power  is  seen  on  the  aide  of  tbe 
le«i><n  oiiily,  we  ahotdd  add  that  ibis  statoineni  a]>poara  to  apply  chiefly  to  tbc 
ihotacic  and  lower  {mtis  of  tbe  cord.  We  hare  seen  thai  in  man,  in  tbe 
iiiijicr  r«f[iofls  of  tbe  card,  the  pyramidal  tract  is  oolr  jMUtly  cniwexl ;  a  vari- 
oolc  but  not  inconndernhlL-  uuml>ur  of  the  ]tyrumiuul  (ibn«  do  not  cros>  at 
ihe  decnesation  of  pyrami(K  but  running  strwifrht  down  n*  the  direct  pyra- 
nidAl  trad  uAvct  tbcir  croiwin^  Inwt^r  down  In  tne  Cervical  and  up|)er  tlmra- 
dongMMW.  Hence,  weabould  infer  that  a  heraineetioo  of,  or  a  lesion  conlioed 
CO  one  side  of  the  cervical  cord,  wniihl  allect  the  voluntary  DiovementA  of  the 
gfoawd  »ido  as  well  us  of  the  eanic  mite,  though  not  to  tbe  some  extent.  But 
we  have  no  cxncl  information  w  to  tbi»  point.  And,  indeed,  the  pur|>oeeof 
the  iliriTt  trad  i#  not  clcnr;  there  is  do  mlei)iiato  evidence  for  the  view  which 
has  lieen  held  that  thc«e  direct  tihre»  are  dc«tine<)  for  the  upper  linihs  nnd 
upper  fwri  of  the  body  ;  since  they  are  the  last  to  cmas  we  should,  a  priori, 
be  inclined  to  suppose  that  they  «ere  distributed  lu  lower  ratlier  than  tiigtwr 
pans. 

i  666.  We  KUiy  now  briefly  Huinmariie  what  we  know  cooiieniiDz  volun> 
tarr  inoremente.  Awl  it  will  be  convenient  to  trace  ibe  events  in  ortler 
backwanl. 

Certain  muscles  arc  thrown  into  a  ooniraelitju  which  even  in  the  krioAst 
movemeuta  is  probably  of  tl>e  nature  of  a  tetanut.  In  aliuu't  every  inove- 
meni  wore  thao  one  muitcle  iu>  defined  by  tl»e  analotubu  i>  cngnged,  and  in 
many  mnvem«Di«  a  ftart  of  several  muscle  is  empli>ye>l.  and  not  tbe  whole 
of  each.  It  i*  perhafw  partly  owing  t»  the  latter  fad  that  a  mtuclv  which 
hM  iMOOtne  tired  in  one  kind  of  movcnieni,  may  show  little  or  no  Intigue 
whw  unptoyctl  for  another  niovcmeol,  though  we  must  boar  in  miiul  that  in 
m  volnotary  nxiventeni  fatigue  it  much  Biore  of  nervous  than  of  niitscular 
ar%in. 

Boidai  iba  active  niusalea,  if  we  uuiy  so  call  them,  which  directly  carry 
out  the  moveineiil,  tho  metabolism  of  which  lupplios  the  energy-  given  -hiI  as 
work  dune,  uthcr  musclM,  •ome  of  which  arc  antagonistic  to  tlic  active  mu*- 

U 


TBB   BltAt<7. 


cles  anil  mmi.'  nf  uhicb  tniiy  W  #)M>kcii  of  lu  sdjuvaat.  caler  inUi  tbr  wlial* 
act.  Jo  fl«sii)ti  for  iiutancu  of  thp  fomrm  ou  lh«  ami  il  is  itot  thf  Boor 
muBcles  only  but  lh«  cxienmra  also  nbich  arc  eDpiK«<l.  Acconliuic  tu  tlir 
inini«<l lately  prccwlitiK  poeilion  and  use  of  the  arm,  aixi  according  u  tbt 
kind  and  auiouni  of  flexion  which  is  bi  be  tarried  out,  tJw  exteoacm  viU  bt 
either  relaxed,  ihat  is  to  say,  inhibited,  or  thruwD  into  a  certain  amciant  al 
vtmtrnvtiou.  And  in  some  of  the  more  ooraplicnied  voluut«ry  niovvin*rm* 
the  part  played  hy  adjuvant  muaclea  is  oousiderabk.  Henoe,  in  a  voIudMi; 
nunrem«ut  tlje  tvUl  btis  to  uuin  acee«»  not  uuly  tu  lli«  a4:tivi;  niuitclc*,  but  alia 
tu  the  unttiifonUtic  aud  aiguvaal  muscles;  and  uvcrv  vnhintnry  movcraiiit. 
tvea  one  of  the  iiiiupleot  kind,  is  a  more  or  Icm  ciinipli'x  ain. 

Tlie  imi)ul«i9  nhicli  lead  l»  tlie  cuiitrautloa  of  the  active  niUMcUti  r<.-nel)  lb* 
miiscl**  along  the  fibreu  of  tlie  auloriur  ruoti  (vie  may  for  ihv  snki-  of  um- 
]ili<-ity  uke  ftpioal  nervea  alone,  neglecting  ihv  pci^tilinr  rranial  n«rv«s).  asii 
lucb  evidence  as  we  )iaasen  goes  to  aliuw  llial  the  ira]>ul«ea  governing  the 
antagonintic  and  adjuvant  nniitdeii  tmrel  hy  the  aoterior  roots  mlao;  the 
question  wb«>lh«r  the  iidiibiliun  of  the  antagonistic  ninsclca  when  il  lak« 
place,  is  carried  out  hy  inhiliilnry  iupulsca  paning  as  #ucli  alon^  the  fibre*, 
or  eimjily  by  cuotml  mhibiiion  ^f  jiravioiisly  existing  niot^ir  inipuls«s  need 
not  be  conei'lcrcd  now.  Thntc  luilerinr  niots  are  connected,  an  we  have  smb. 
with  tlie  gray  matter  of  Ihu  cord,  and  in  each  hypothetical  segnieut  of  the 
cord  ire  mav  recopisc  the  existence  of  nn  area  of  eray  matter  whicbt  thoa^ 
ue  coQuoc  define  lU  limits,  tve  mny,  led  by  the  aouo)^  of  the  omnia)  uervca. 
call  the  niicWti  of  the  nerve  belonging  to  the  aegineut ;  and  we  luay  further 
recognixe  in  such  a  nucleus  what  wo  may  call  its  efferent  and  'Ha  uflervnl  Mde. 

Kvery  voluntary  niovoment,  even  the  sinipleet.  U,  as  »'i-  have  reneatnUy 
ioriitted,  a  L-o'inlinaied  movement,  and  in  it^  courdinatiou  atfcri.'nit  itiipuhu 
play  an  tmpuriant  pan.  The  study  of  retlex  nctioiu,  §  590,  haf  led  us  l» 
Buppoec  thut  i-Hcb  9)>inal  oegtnent  presriiln  a  uervout  mechaiiisni  in  whlcJi  > 
certJiin  nniounl  nf  coiirdinMiou  in  aln-nily  pn-veni,  in  which  «flhrent  impubs 
are  ndjiittU'd  in  aSiirent  iinpiihnai.  But  the  mulls  obtained  by  atirauullac 
iteparale  stitfrior  nervf  rootn  itbow  that,  in  the  case  of  moat  rotneleB  al  aii 
events,  the  cfnin'inlly  active  niuncloi  of  tbo  limb*  for  iitttAnic.  each  nmsckh 
supplied  by  tiling  coming'  from  more  than  (MW  nerve  root,  that  is  to  aay,  iht 
»ptnal  nu<:leus.  or  nt  I'uiHt  llic  npinal  motor  mechanigni  for  anv  one  tnnsds, 
extends  over  two  or  three  segments.  Honce  t  /oriiori  in  a  vofuntary  mon- 
ment,  involving  as  this  does  in  most  case*  more  than  one  miude,  the  opial 
Inechanism  engnevd  in  the  act  spreads  over  nt  least  two  or  three  sef^nHMs, 
thus  allowing  of  incratsed  coordination.  In  that  coOrdinaiiuu  the  tmiMho 
serving  as  tne  foundation  of  muscular  sense  piny  an  imjairtant  (Ntrt,  biH 
other  affbrcni  impulses. such  as  tbuse  from  the  adjoining  skin,  ulsu  have  thtir 
■liarein  the  matter;  and  it  is  worthy  of  nolice  that  not  only  ia  the  skin  ant- 
lying  a  muscle  served,  broadly  Bpcaking,  by  nerve  roots  of  the  same  legmait 
as  tite  rouBcle  itself,  aflferenl  in  one  cafe,  eflerent  iu  the  other,  but  in  tin-  part* 
of  the  body  where  coordination  is  especially  complex,  in  the  liagi-r«  dir 
(nslanoe,  not  only  is  each  muscle  supplied  from  more  than  i>w  siytufnt,  luit 
also  each  piece  of  skin  is  supplied  in  tlie  »iue  way  by  the  jMnicrinr  nmu  u( 
more  tban  one  nerve. 

In  the  case  of  ttie  fVog  it  b  clear  that  iu  reflex  movemenin  a  larp.-  amnuai 
of  coordination  is  carried  out  by  thaw  \'arious  spinal  meeluintsnu:  aud  as  »v 
have  ur^t^,  ne  may  safely  infer  that  iu  tlie  voluntary  movements  of  the  ftnf, 
ibe  nill  ni»k(«  use  of  thU  olrewly  exietinK  ciHiniinatioo,  whatever  be  lb* 
exact  |iath  hy  which  in  thi.4  animal  tlie  will  gaiii*  aoc<a«  to  the  spinal  iDwhan- 
iama.  In  llic  'Iok  we  may  conclude  ihnt  in  voluntary  movraienl^  the  sjiiaal 
jBKhanwn*,  with  ojurdinating  faocliunt,  are  also  set  in  action,  iu  this  <  ~ 


ON    robUKTAftV    UOrBMKNTS. 


835 


I 

I 


I 


/ImpiiUes  ptunio;;  !imi;;fai  Trora  Ui«  cartel  to  ihe  nieclniRuiiM  lir  ilio  |iyrn- 
luiilnl  tract,  tlioti]{h  a|ipiir<-utly.  in  tli«  absence  oT  the  pvrumiil.il  tract,  I  he 
will  am  work  uvum  the  oii-clianuiiM  hv  changes  travelling  thniu|ch  other 
pttru  of  the  cereoru-4i|Huat  tixiit.  Ad<I  in  the  ntitiiltej- aiiil  laati,  yubjwt  to 
ih«  doubu  alreuily  vzpnMed  aa  to  the  iioii^iiLiiilititi*  i>(  tho  human  spinal 
cord,  mt  may  {imlKihly  abo  infer  thni  in  mnh  vuluiiinry  marcmenl  KOmo. 
parhii|H  <rv  luiir  Mty  much,  of  th«  cminliiinliim  u  currivd  out  by  tho  ef/iiinl 
■DMhauitim  wl  iiilu  nctioii  through  impultw  nlnng  the  pyramidal  tract.  W« 
may  probublv  further  inror  that  a  careful  niljugluionl  obtains  botweeo  the 
baiginDinK»  »i  (h«  prnimidal  tract  in  the  cortex  and  it«  i-ndiniri  in  ih«  conj, 
Hj  that  tha  topography  of  "nrca«"uf"  foci  "in  thr  cortex  above  ic  an  imagv 
or  prajvotion  of  the  ttpinal  mcchaniama  bolovr. 

Tba  aompJaz  eharact«r.  on  which  vrc  iniiated  jiMt  now,  of  alnioel  eveiy 
Toluntary  mov(Mn(>nt  ncccssilaica  that  in  every  such  movememt  a  Urge  area 
of  iipinal  mechanism  is  involved.  Bnt  this  L»  not  all.  The  muTenieuta  of 
•Djr  pom  of  th«  leigs  for  initanoc.  niv  not  delermioed,  nor  is  the  oo&rdiuation 
of  the  movements  aflected,  simply  by  what  la  i;oiiig  on  in  the  l«gs  and  the 
part  of  the  spinal  cord  belongin);  tu  theiu.  The  diacuiMioa  iu  a  previous 
Mctioa  hoa  sbown  that  much  of  the  courdtnacioa  uf  the  body  is  carried  out 
b/  the  middle  p'lrtions  of  th«  brAiD,  and  oa  theee  the  mo^r  area  mii«t  have 
tu  hold  an  well  as  on  the  spinal  mechantsnis. 

The  detail*  of  the  nature  of  that  hold  are  at  preaeat  uoknoiru  In  lu:  but 
it  muKt  be  remembered  tliat  not  all  tht-  libr^  uasnog  down  from  th«  motor 
reciod.  not  all  thoae  even  proceediui;  from  tiiu  (U-uit<Mt  nud  mo<l  uleurly 
dehoeii  motur  areas,  are  prramidal  tihre*.  Witli  the  pyramidal  Qbrej  arv 
minuted  Aitr^  having  other  dcali nations,  aud  aoue  of  those  probably  pium 
to  toe  thalamus  and  so  join  the  Ertat  Mgmeatal  ref^on.  Moreover,  tb« 
faotof  region  muot  liave  close  liee  with  otlwr  rcgiona  of  the  ooricx  wh«nM,  as 
wo  hava  saen,  ^  ^'i'i.  dbnt  nasi  to  tho  pons  to  make  connections  with  the 
eervbvllum.  On  the  other  band,  as  we  baro  Men,  $  113,  tho  corcbellum  ts 
vspccially  conrtccuvl  with  what  wc  may  fairly  consider  tlic  aflorent  >!!d«  of 
this  e|>inal  cord  nnd  bulb.  Tli«a«  facte  must  mereljr  be  lakeu  as  indicating; 
ihe  powbititiee  by  which  th<r  motor  region  is  kept  in  toucli  with  the  great 
onordiDadog  mecoanism  ;  it  would  be  venturesome  at  present  to  say  much 
mora. 

In  an  ordinary  voluntary  movement  an  intelUjceoi  coaaciousaeas  is  an 
eaiential  elemeoL  But  many  skilled  movemenbt  initiated  and  repented  by 
help  of  an  intelligent  conscious  volition  mar,  when  the  uervons  machinery 
for  earrying  them  out  has  acquired  a  oert^n  Gicility  i,niid  in  all  the  higher 
prooeisCB  01  the  brain  ire  must  reeogniie  that,  iu  nervoud  losterial  at  all 
events,  action  detenntnes  structure,  miauiing  by  structure  moleoular  arrao^- 
ineut  and  dts|HMition)  be  carried  out  under  appn>priat«  circumWancw  witli 
ao  little  iut«rventtoii  of  distinct  oonscioutnaai  tliat  the  moveinesits  are  then 
often  >pokcn  of  an  involuntary.  All  the  argtiRientx  which  go  to  show  that 
the  dtttinctly  euuscious  voluntary  skilled  movement  U  carrieil  out  by  help 
of  the  appropriate  motor  area,  fpt  tii  *liow  tliat  the  motor  area  oiust  play  its 
part  in  thwe  involuntary  ^killetl  movements  also.  So  that  diftind  consaous- 
nea*  is  nut  a  neoesaary  adjunct  to  the  activity  of  a  motor  area.  And  it  Is 
worthy  of  nolioe  that  aoaie  of  these,  in  their  origin,  purely  voluntary'  skilled 
muTsmMits,  which  by  lone-cimiinued  training  have  Decome  alauMt  as  purely 
involuDtary,  am  hamfKrcit  rullu-r  ihAU  uvintcd  bv  being  "thooght  aliout." 

The  wonl  "training"  »tiggw>ta  the  retlcclion  that  the  phyaiologieal  intor- 
pretatiou  of  bocomiiu  easy  by  practice  is  that  nc<r  jutbs  are  nuule.  or  tho 
iRateria]  of  old  [Mtb*  tnads  mors  mobile  by  effort  and  uec.  We  liave  already 
1, 1  582,  that  the  gray  autter  of  Ihe  spinal  cord  is  a  network,  in  whioli 


83S 


TUR    BBAIS. 


l(i«  iwsaigo  of  impiilwn  w  il«ti»tniD«l  b^  phynokwlfitl  OKiililioat  ntJwf  than 
BRBtoiDiciil  coiiiiiiui(y.  mtd  lh«  mnio  coomaenUKim  ribv  oiih  «ttll  grauw 
Turce  be  np[>)tc<l  In  thV  brain.  W«  inual  Hipp>iM>  thai  training  proinatc*  iIm* 
groKth  and  mQlecular  mnbitity  of  thi'  motor  areii  and  of  nil  ita  vonDvilioU) 
1  herv  nre  doubtlas  limits  to  tbe  cliangcs  nhicb  am  he  elTcctetl,  but  wilbn 
tlwae  )iinil«  tbe  will,  blundering  nl  Rrst  in  the  niaice  of  llie  nervous  network, 
gradually  eetabli?h«:  ea^y  {nibs;  ihixt^li  even  to  tbe  end  it  blunders,  in  trt- 
■nr  to  csrry  out  one  movetneni  it  olieu  aro'tnpliHlies  anoitier. 

ijutly,  witbiiui  nlieiiipiioK  to  enter  iuu-  iKViholnffknl  (juciilioo>,we  Diaval 
K-Mt  uiy  that  the  birthplace  of  what  ire  call  tbe  "  will,"  ia  not  enotemiaa** 
with  ibo  motor  area;  the  will  arises  ftom  a  owtnplox  «eriea  of  «Teau,»iDenf 
which  ittke  ptave  iu  mlier  rewioria  of  the  oonex,  and  pmhably  in  oiber  parti 
of  the  brain  as  well.  With  Ihese  |Min«  ibc  motor  arcji  hax  l\«*  ■■nncrrneil  un| 
in  tbe  carrying  ■>■![  of  volition,  but  in  the  gwemtion  uf  ibi^  will.  So  ibii, 
looking  round  on  all  sidts,  it  >«  (tltviouc,  m  uc  have  aid.  that  ihr  imtor  am 
is  a  nn-tv  link  in  a  complex  ihnin.  It  »,  moreover,  a  link  uf  nich  a  klid, 
that  while  iliv  changn  which  the  breaking  of  it  makn  in  the  daily  life  of  % 
lowly  animal,  <uch  a«  the  dog.  in  whom  tlw  expi'rieon-of  the  individual  otMl 
relatively  little  In  ihe  tM.'n,'ouv  and  p>ychica1  »i"rehouEe  iraitcmilled  from  hii 
ancertors,  can  hardlv  b«  a|>prt.-ciatcd  by  a  bvMaitiier,  tbosp  which  tbe  breai- 
iot;  of  it  make*  in  the  daily  life  of  a  man,  whu«e  brain  at  any  ninmenl  ii  not 
only  a  machine  fitted  for  present  and  Aitnre  work  bni  a  <'li«ely  pucke<)  reeorl 
of  bis  pBBt  life,  are  obvious  not  only  to  tbe  individual  himself,  but  lo  hit 
felloWB. 


Os  THK  UEVBt-OPMKST  WITHIN  THK  CkXTRAI.  NeRTOIS  SrSTKlt  Of 
Vli>UAI.  A!iII»U»'!^>M>:  iiTllltK  8ut«ATIO!CH 

ritual  Stntntim*. 

^  087.  In  the  chain  of  events  through  which  some  influence  broi)f>ht  to  bar 
»u  the  periphery  of  a  senfory  nerve  gives  ri»e  1«  a  senealion,  we  are  abb, 
with  uore  or  len  success,  to  disliuguifib  betweeJi  those  eveuts  which  are  ilettr- 
niined  by  ibe  changee  at  ilie  periphery  and  ibooe  which  are  die  cxpfoaica 
of  cItanKes  induced  in  ihe  central  nen~»us  system.  Tbns  when  rertain  njt 
of  light  proci'e<liug  from  au  object  and  iBlliiiji;  upon  the  eye  give  rt>c  in  viraal 
perceptiouuf  the  object,  two  aeUnfeveiiis  hii{i|icu:  ibe  rays  of  light,  by  Mf 
of  tbe  mecluuiisma  of  the  eye.  partly  dinpirK-.  partlr  ncrvMis,  give  riw  tu 
wnnia  chaiiM^  in  the  tihrcH  uf  the  optic  nerve,  which  we  may  mil  vtraal 
iro]>iit«ni:  and  lht«c  vtMial  ini{HilM«  reaching  tlic  brain  along  tlie  oMic  iierft 
give  rim-  to  vtMial  n-imtion.''  and  m>  to  visual  pcrcc|iti<>ii  of  the  ohiecl.  Vft 
■hnll  tnl<-r  on,  under  tlie  beuilingof  "the  *en«n,"  deal  chiefly  wilh  the  [leripb- 
enil  evenln.  and  havv  now  to  ci'iiiiii1<<r  »ime  point*  conwcled  nilh  the  central 
eicnw.  lo  learn  what  »i-  know  coiici-ming  how  the  variou*  K-n»'<ry  iinjiuW 
li.i veiling  along  the  several  kimlsof  feiisory  n<in'<*  behave  wilbin  ihe  central 
nervou.<  system.  In  doing  so  we  shall  have  from  lima  to  time  to  refer  Id 
peripheral  events,  but  onh'  occasionally,  and  never  in  any  great  detail.  It 
will  be  i-onrenieni  to  begin  with  the  spocial  sense  of  Rght.'  and  we  must  6nl 
briefly  call  allcniion  to  a  few  points  which  w«  shall  have  to  study  in  fuller 
detail  herealler. 

Tbe  eye  is  so  constructed  that  image»  of  exicnial  objeds  are  brougfat  u>  a 
focns  on  the  retina,  the  stimulation  of  which  by  light  starts  liie  visual  ira- 
ilsea  along  the  fibres  of  the  i}|>tic  nerve;  and  tbe  distinctneai  with  abieb. 
ty  iDcaoB  of  the  visual  seii^iations  arising  out  of  these  visual  impalm,  irv 


vrSFAL   Ayi>  OTRKR  StySATIOMS. 


I 


I 


prrwirc  extenwl  objocU  Ja  ilepeodcut  ou  ihe  ithnrpnMs  of  ihe  retinal  imogee. 
Tlie  ere  is  further  so  c(in>^ruc[etl  that,  in  auy  (Wftition  of  thir  eye,  the  rsya  of 
lilfht  (irooeediiiK  ttom  a  portion  only  of  the  pxionml  wiirlil  fall  upon  tli« 
rMtna;  or  in  otlier  wordi.  in  any  one  pasition  of  the  eye  only  a  {Mrtioii  of 
[b«  external  world  ia  visible  at  the  same  time.  The  |Mrtion  to  teen  is  tpokea 
uf  an  Ihe  runuif  field  for  tluil  pueilioo. 

The  iniafce  tJ)n>wu  od  Ihe  retina  la  au  inverted  utie,  so  that  the  top  of  an 
HcKnil  obJH't  i.-<  r«prf!<eDtM)  by  the  lower,  and  the  bouom  by  the  upfier.  |)art 
of  ibe  tetiiuil  iniflge ;  similarly  the  a«ttud  lefl^haud  lide  of  thv  reliiial  ims)^ 
r(>rrTH|Mi(KU  to  the  rijtbl -baud  *i<le  of  the  artoal  obiM.-i.  and  the  rigbl-liaud 
niilo  tu  th«  len-hanit  side.  Hence  llie  rigbt-liand  half  of  the  rinual  li<-Id 
cornwiMnfU  li>  tltv  Ifd-haiid  »i(le  of  (he  retina,  nnd  ibe  left-hand  half  to  the 
rigfat-liand  *id<-. 

The  ■■vc  can  be  movcl  in  vnrioun  itiructioDv,  and  diner  in  ibc  vimiuI  field 
thr  (Mitlioii  of  cxlvmal  nature  n  hich  aio  be  wen  ai  the  Aine  lime  dilfem 
with  i^ch  dillirri'iit  |H»iii<>n.  ii  large  range  of  virion  i*  tliu*  iRMured ;  nii'l  ihiH 
CTUi  Ik  further  iiit'reii»^'d  by  nioveroonUt  of  the  l»-iid.  Moreover,  wc  iic.r- 
mally  tankti  u*o  of  twi>  vy««:  our  normal  riwon  i*  binocular,  and  lliv  visual 
(i«KI  of  tW  ri|;ht  pyi<  diflvrs  from  tJial  of  the  left  ere.  There  n  one  »trikiiiff 
diHcrcDcv  u'hicb  must  always  be  br>nie  in  mind.  A  H-clion  earned  ihrougn 
the  eye  in  a  vertical  iin<l  front-tu-back  [ilaDe.  through  what  ire  tihall  learn 
to  call  Ihe  optic  axis  (Fi|^.  'J1 1. 1>.  r.)  (the  exact  details  of  the  plane  nuiy  be 
left  for  tbe  present^  will  divide  the  rcltna  into  two  lateral  hsKes,  an<l  in 
each  rvlina  one-half  will  be  on  the  uaaal  sitle  ucxi  to  the  noiie.  and  the  other 
half  will  lie  on  the  malar  or  tenipornl  side,  next  to  the  check  or  temple.  It 
roust  be  retuenibervd  that  (he  na«il  halves  and  lemporal  halves  of  the  tiro 
retinas  i|i>  not  occupy  currM|)oodiiiK  poeitiona  in  apace.  The  teniiuiral  half 
of  tbe  leA  retina  is  »n  the  left  tide  of  ila  own  eye,  wherenja  tl>e  teni|M>ml  half 
uo  tbo  rieht  retina  \»  not  on  the  left,  hut  »ii  the  righl.  side  of  iiM  nye:  and 
M  witb  ine  nami  halv'v.  Now,  in  lh«  ri)tbt  rye,  (Ik-  ri);hl-hniid  niile  of  the 
THual  hi-ld  oimsponiU  lo  the-  nit--><l  half  of  (lie.  r4-ti»:i,  and  the  Ict^-hnml  vide 
of  tlw  visual  Held  to  tht  tem|H>ral  half  of  thr  retina,  wh<-rea»  in  (be  left  eye 
ibe  right-liand  nide  of  the  visual  lichl  «irr«!«|M'ndit  (n  the  temporal  half  of 
the  mina,  and  tli<>  left-hand  niiie  lo  the  niual  half.  This  ia  snovn  in  Pig. 
'it  I,  where  ihv  left-haiul  vtMial  Hold  ami  the  retina]  area  conocrnMl  are  shown 
sbaiied  in  mch  eye. 

Wben  we  look  at  an  object  with  iho  two  eyes,  thoufjh  two  retinal  images 
are  |>roducc<l,  otM>  in  i>no  eye  and  one  in  the  oilier,  we  perceive  one  object 
only,  Uut  two.  This  is  the  eswntial  fact  of  binocular  vision:  wben  certain 
parte  of  eaeb  retina  are  slimntaied  at  tW  same  lime  ue  are  cviusejouS  of  one 
MOMliou  onlv,  nut  two ;  and  tbe  parte  of  the  two  r«(i»as  which,  MiniulaiH 
■t  the  same  lime,  f{ive  the  lo  one  senaation  are  apoken  of  as  "  rorrts|M>ndirig 
parts."  Froto  ihc  Airucture  and  relations  of  the  two  eveb  It  follows  that  ihv 
temporal  ud«  of  tin?  rijfbt,  awl  Ihe  nasal  side  of  the  left,  ejre  are  such  cor- 
reapondini:  tairts,  while  ihe  narMtl  aide  uf  tli«  ri)cht  eye  corrw]M>ndM  lo  ibe 
iem|Minil  nidi?  of  the  left  eye.  Itut  the  whole  of  each  retina  is  not  employed 
in  biniM'ular  vtMon.  Owin^'  to  ib<:!  ihnition  of  the  two  eyes  In  relation  to  (he 
noec,  it  come*  ah<-)ut  that  un  objccl  field  very  much  on  one  «ido,  to  the  (o(t- 
haoil  aide  for  iniHaocc,  while  it  is  aipable  of  pruduc4ng  an  iiua^  on  tJ>e 
•xtmne  aami  nde  of  tlw  left  eye,  and  can  be  M«n,  ttwrnforv,  by  Ihal  eye. 
cannot  prodtice  an  Image  on  thv  t«ni|ioral  aide  of  the  right  eyo':  the  nose 
blocks  tlie  way.  It  i>.  tborefure,  not  eeeii  br  tbo  right  eye,  and  tbe  vision 
of  it  is  monocular  br  tbe  left  eyo  onlv.  In  Fig.  'Jll  it  may  Im-  seen  that  the 
left  visual  tielil  iif  ine  left  ere  <  L.  /'.  L. )  extends  more  Ut  the  left,  and  is 
larger  than  the  left  visual  licjd  of  the  right  eye  {L,  K  Jt.),  and  that  the  right 


riaUAI,  AND  OTHKR   SENSATIONS. 


retinal  nrvm.  cnrnwpondiii^  lo  iImk  left  risual  field,  extends  furlhrr  nloi)^  Uio 

nasitl  aide  of  tin'  lirlt  tide  (o'l  than  It  do«  bIdii;;  the  tcmpciral  sido  of  tbo 

right  ryti  (a'>,  thp  diftvretiee  beinR  due  lo  the  presence  of  the  non  {F.\. 

I  And  MiniUr  conditiooa  obtaiti  vitb  regard  to  the  extreme  rij;bt-hand  aide  i>r 

'  the  viMUftl  Held. 

h  i  868.  Xher  ihcae  preliminary  stateiuenta.  ire  may  now  turn  to  consider 
■MRHv  anaioRiicfll  facts  eoiii'eniing  thi.'  ending  of  ihe  optic  nerve  in  t)ie 
fbniiD. 

;  The  optic  aerve  of  each  eye  oouaiUa  of  nerve  fibres  comiDg  from  all  paHa 
;  of  tha  retiaa  of  iliat  eye:  hut  tlio  two  optic  nervt!!  iiioeL,  ventral  to  tlie  tloor 
I  of  the  itiird  v-eulriclv,  <-ruM  each  other  lit  thi;  opiie  rhiiumut  i  Fig.  'Jll.  Op. 
/Jr.\  sod  are  tlieocv  ountiDued  on  umk-r  the  name  uol  of  onlii;  nerve*,  hut 
I  of  itfjiF  <r»fU  ( <tp.  T.I.  The  decuwtutimi  of  fibre*  which  taKu.-<  place  iu  the 
cliiaaaM  luu  pet-uliar  rliiinu'ten.  Al  their  deciimlion  (wc  are  spcukiug 
DOW  of  man  l  the  flbriat  in  tlio  optic  iicrvv  Imloiiging  tn  tlie  tenipoml  half  ol 
tiie  eye  iu  which  the  ncrvu  ends  paM  into  one  optic  tract,  itiimrly,  the  uptic 
trmet  of  tlie  Mine  viilc,  while  the  fibrts  beloDgioe  to  the  nanl  half  ww  ii)l» 
another  optic  trmct,  namely,  the  optic  tract  of  trie  opposite  sidir.  Thiiii  the 
Rhm  of  ihe  tenipoml  half  of  the  right  eye  and  of  tne  oaaal  half  of  ttic  \t(t 
Cft  pWH  int'i  the  right  optic  tract,  and  the  6bre»  of  the  nni|nl  half  of  the 
right  eye  and  of  the  temporal  half  of  the  led  eye  pass  into  the  \«fl  optic 
tta«t.  Compare  Fig.  'J11,  in  which  the  tibm  forming  the  right  optic  triict 
MC  ihaded.  white  thiMo  forming  the  letl  optic  tract  are  lelt  nnshadcd.  Non 
tbv  OMbI  half  of  one  retina  and  the  temporal  half  of  the  other  retina  are 
" cocTwpond i iig  "  parts.  Hence,  while  each  optic  trad  contains  fibres  be- 
loo^ng  to  half  of  eai.'b  eye,  the  two  halves  thuii  re j) resented  in  each  tract 
are  corresponding  halves. 

The  amount  and  character  of  the  decitiwation  tukin)i;  plai-e  iu  the  opllc 
chiuaia  difiitRt  in  dificnuit  aninuil  lvp<«.  ihc  di<r(:rrnci.-ii  having  rvlation  to 
the  amount  of  biixictilar  viiiion,  which  in  (urn  de[>i-ndgi  on  tho  pnoitioo  of 
the  eye*  in  the  head,  that  i«,  on  the  prominence  of  the  fiioe  between  the 
evM.  In  the  liah,  for  in«tanc<:,  with  hilcTnlly  plni^od  rym.  n<>  binocular 
virion  at  all  in  pari ble.  and  the  dccuwntion  in  complete-,  the  wholu  optic 
nerve  id'  each  eye  cronei  over  to  the  other  optic  tract.  Betwwii  this  and 
tha  amngcnwnt  in  ninn,  juat  described,  vanoiia  stage;  obtnin  in  various 
aniomU. 

The  cJiiasma  nlao  eonlains  nt  it#  hinder  part  fibres  wbicli  have  no  <-od- 
nection  with  (be  optic  nerves  or  (ho  eyes,  but  are  limply  comintwurel  tracta 

IWMing  from  one  side  of  the  brain,  nantely,  from  the  luealian  corpiii  geniuu- 
atum  ($  631 )  along  one  optic  (ract,  through  the  ehiaema  to  the  other  optic 
tract,  and  b»  to  the  iiietlian  cor|Mia  geniciilatiim  of  the  otlier  side  of  (be 

tM*ia«l>lil«nf  UiartUravr  (ber1sblCTD>adilien«Mltfilaaf  llioi«Uniiof  tae  kA  oyv:  U  K  L 
■ndr  r.  ff.  Ik*  trfl  <l»a)  IMdiirf  lln  Ml  ■»«  M|M  pjw  t«pntl**lV;  ibo  Ivo  AtUiakl  tk«|«ft> 
e4  lb*  ■••»  nUniwwIinc  «M*UUIiia  ffaAara  ttoloii  mwt  llM  BtMi  an  thwlcO.  Uwo*jMtala  tlw 
aiUdf  Itilrtstil  4M«  CI«1li(  iVa  lukniiiMC*  Mn'.  ■uit  noitUMlatt  iMdui  laaKsal  ■■'.  Tlie  ni|h( 
mfUie  limet  h  i»pr— aloJ  ■•  (lattiiK  lii  'i  I,,  ilic  l*l«i»l  iinrtiii*  VMkl«iitol*pi  -.  Ill  Jv.  ibo  taliimv . 
«hI  lo  A  tf.tbc  akleitnt  rar|iM  •iiiHlrleialnBiii,  all  tlim  illiiiilfit :  op.  nul.  ttK  ofCIn  ndlaUcn 
(rum  Itww  bolm  !••  It.  Or.  tba  rffkl  otvli^Ml  lobr.  mkiv  •tln4wl  nslDK  Indlrals  Ik*  "vlnia 
f  it.  ib(  ~<tiniri"  inrt  to  Ibtenmu:  ••■.  mcpu*  rallixiiM,  tWacmaai  ibr>i<lmiuin  -.  i.  :d. 
\Ut  IKHU  or  lb«  IMonl  (WMnale :  llw  kfl  lUr  Iu*  bn»  adUUei  ■•  ln<tln(c  lU  F.  (liwM 

Utn*.  ibt  (vnWI Mouw arw  bir  Uw ']ra ;/•-'.  In-Uoiw  Ik*  |iMh  fhHn  ii  t»  III.  IV.  VI.  tha 

nwUI  una*  Iblnl.  tuonh.  ftn<l  ill  111  Mim:  |>.  t.  Ikt  tnXirtnr  l<nitltii>1inal  biiiull*,  •teffii  a*  a 
b>uk««  llnr;  .V  C  Uc  nwttiu  «u>lalin;  t-V.ia«  niiclaui  iMMculatti:  an.l  T  U.opHe  UialatDiu 
atumi  InaMKno:  f*'.  Ibo  l><in(  M»b,  ritf.  Ik*  kaaa,  ami  r^i.  lb*  blurt  llnli  OT  lb*  iliWroU  rapaul* 
7W«(llilll«ief  Ik*  limrili  iviilrlvlik  lib  l^aMluTlhe  inMctlar  fotpon  iiBdncMBlaa  Siv  •!»*■■ 
tir  *toU*d  ltn«^  ihai  ol  Uw  bulb  M  •hown  I?  a  iIim  IIiw  ;  ji,  Ibe  tMnaal  «IumL 


■riian 

m  ciMUiecfe«l  vid 
whidi  pK>  h)  (««j 
M  Uiai  («n  of  I 
iW  rMiDJU  uf  tif  I 
in  rkkAn. 
icwllr  in ! 

grmr  Dutur. 
«od  to  DtAtn  I 

iiy  (if  thr  (W 

of  tibrrv  pncM 

•(■read  iiai  tau 

■deimble  lunbi. 

■EtMT  eornus  quadrisMaaBS 

^  _  _  MytiOlly  In  Uie  nerwolk 

If  Mdr  ionB  of  tbe  ufiiic  tnct  i^ 

\we  hieral  enrpm  EwicHhttB. 

i|— liigirinmiiii       PuHtwr,  ««  bn 

pwtal  ali  eveuu  ••'■■'■■■  /ray 

I  wilfc  >ad.  ID  ■  <«ftAin  ><  -fidMB* 

■«>5  fttiM  ill  mplik  CTiilre  it  d^gcnenlw;  k« 
fU  fflrlilMi  aad  Mm  loa  of  tke  ptripfaenl  dtgvDcrating  portion  bM  «^ 
(itivifMi*  aAd  on  lb*  tnftoe  eeotre:  wbn  r  >iniMl  ncrv»,  for  imUMv.tiH 
i|i'     I  '   m  tit*  •fiiiul  naftliM,  tboufjli  tbe  a«r>'r  Mow  ili«  «!c(n«4te*-  ^ 

nnr  iiikUhd  anil  tu  pJMC  of  nerve  in  oWDPclion  with  it  nmaiBfK* 

itiiirli  n«  UfoTv,  ««  Itftve  it,  tiowerer.  in  oar  pover  to  brinj;  Abuut  c1wh«*( 


1>41 


nni)  wilier  charnetiT.  a  c-nwotioti  of  Kn>vn\i  nmountiii);  to  atro|>hT, 
iltvi-  iiiicrfi-Ti'iici-  with  ihtvuu*  iilriii4iin«  lictiiro  ihcv  nre  fnll_T  tle- 
Vttlopcil.  Tbiix,  in  nn  mlult  tiiiiiiiitl.  ii  >ri-ti(m  nt*  iin  Dptic  nerre  or  removal 
of  tlH-  vyv  Irjiils  to  ■k'^^iicrutinii  in  ihi-  npiic  m-rvr  uml  optic  tnict :  tbc  aptto 
Ibn*  )iii\'<-  lh<*ir  lr>i)ihic  mntri-  in  (NTlaiii  ocllx  iiI'  lli<'  rptina,  nl'  which  «e 
11  >|iruk  in  In-iiliti^  of  viMoii,  guiil  cut  bwhv  from  tli«l  ccntni  thcv  (legeo- 
lir  lliu  tiK-unn  Ibr  nitluiv  »f  tho  oplic  Hccumation  in  miimtilii,  mm) 
in  mnn,  ban  lievn  n«ccnniD«l.  But  it'  tho  oyra  !«  rcmovrd  i;  rroiiovnl 
bittli  erco  bcinc  dcNDtble  on  accoiini  of  tlip  ctmraclera  of  iho  optic  rlwtw- 
tiun)  io  n  n«wboro  wiimal.  oot  only  do  both  th«  opti<-  ncrv»  nnil  llw 
itirr  |iKrt  of  hiith  optic  tracts  ccatie  to  be  further  develo^wd  and  iK-gan* 
titil  the  hodtm  meiilioned  nbuve,  the  two  lateral  corpora  g""!*'" '**'*• 
-  ulvinu"  on  eneh  side,  and  the  Iwo  unleriur  corpora  ifuadrigeflitaA,  do 
TuIIt  develop:  cctlain  parM  of  tliviu  undergo  atrophy.  The  develop- 
bpl  of  these  oervous  »lrucUire«  seems  therefore  to  be  largely  dopeudetil  on 
■r  funrtiofial  connection  with  the  even  by  means  of  the  optic  tracts  bikI 
Brrea. 

The  Huriie  meiliuil  conSroia  the  view  exprc»ed  above,  that  the  niodian 

irfiiH  i;eiiirulaLuiii  ha«  uo  coiineriiim  with  viaiou.     Wheu  the  eves  of  oew- 

rn  nniiualH  arv  extirpated,  neither  the  mediou  corpora  gcnicuiuta  nor  the 

iinrior  corfMim  ipiailrijceiuioa  ihow  any  au|;ii  of  nlmphy,  and  tlw  part  of 

optic  irut-t  which  doea  aot  ilegenerate  u  the  infcrinr  commiMara  eaa- 

i«itJii)i:  the  two  median  corpora  Kcni"«l*t«.     Obviously  th«e  [Wtrta  are  aaao- 

'ilcd  with   luiictiDnn  of  ihif  bnun  oth<^r   than  thoM  of  sight.     The  lateral 

itjioni  ipMiii-ulatii,  th«  pulvinar  atid  the  aDlorior  corpont<pisdr!grimina,HT«. 

may  mfx.-nt.  ulone  to  be  rcnrdod  a*  the  cliicf  oeBtral  parts  iit  whieh  tint 

10  nvrviv  ctid.     Wc  may  alto  rvpent  that  owing  to  the  [wculiarity  of  tbv 

lie  deciisatidu  each  optic  nerve  thus  finds  lu  eiraiDK*  in  buth  sidiis  of  llie 

in. 

While  th«  optic  cbiaania  is.  as  we  have  aeeo.  h«lpiiif[  to  form  the  floor  of 
ihird  ventricle,  it  ipvea  off  librea  to  the  ouslerior  |>erfi>rated  api*.  fNiine 
tliew  hav«  been  iiuppmwd  to  pa;M  direetly  in  the  wall  of  the  ventricle  to 
nucleiM  of  the  tiiiril  (ooulo-motor)  nerve,  aiid  to  M^rve  a«  a  channel  fur 
t  Impulses,  eausiiix  oonstriclioii  of  the  [itipil :  but  to  this  we  shall 
urn  in  dealing;  heri-sAer  with  the  mov«nivnti>  of  the  pupild. 
^  671.  Th<iii|;h  iht'  aIkivr  three  UkUm  arv  uDdoubt«dly  the  chief  eudiiifcs 
ika  optic  Dcrve.  three  primary  visual  centrvi,  if  «r«  may  ao  call  tliein,  it 
atw  belicv(Hl  that  w>me  fibrea  of  tlrt  optic  tract,  makini;  counectioiu  with 
'ihrr  of  iliw*-  three  hmlii*.  jmih  by  iW  cru»  cerebri  straight  tv  certain 
of  the  cervhnti  licmiNtihen-  t  Fig.  *J1 1.  <f ) ;  but  this  fourth  ending  is  by 
mrans  m>  clcarlv  lyliihliahoil  as  arc  tW  other  thrvn. 
And  undoubtedly  the  nuiin  oounection  of  th«  cerebral  hcinisphere  with 
optic  tract  is  not  a  direct  one,  bui  nn  indirect  one,  through  the  thnM 
ies  in  iiue^tion.  Wc  said  (S&'M)  thai  (ibrea  proceeding  from  the  occipital 
irtex  bihI  reaching  the  thalamus  through  the  hind-limb  of  the  internal 
ipHile  formed  what  was  called  the  "optic  radiation."  Theu  fibres  be^n- 
ng  (or  ending)  in  the  eortei  of  the  occipital  region,  end  (or  begin)  fPig. 
,  i>;>.  mil.)  tu  a  Inrev  extent  in  the  pulvinar  aiid  in  the  lateral  corpus 
iculalum,  but  alw>  in  the  anterior  i>ir|>tu  ifuadrixeniiuum.  reaching  it  br 
anit'rior  braehiuin  '^  t>^).  When  evuu  in  a  grown  nuimal  the  occipiial 
cortex  i-  •lv<troye«l,  not  only  ihe«e  fibriy.  but  also  [nrin  of  the  pulvinar  and 
ril'Tnul  corpus  tirniriilaltini.  iimb'rgi)  dv)ceii('ralti>ti.  and  tliere  !•  some  change 
in  the  anterior  corp«ii*  iiuitdriK<"iiinuni.  When  the  mmo  cortex  is  deatntyed 
in  a  newborn  animal  ibc  .-anie  paru  ntmphy :  and  in  nuch  cbms  the  ontic 
land  ovr.':.  which  an-  but  link  ndixitoil  by  the  g|)er«tioa  in  the  auult 


MS 


TUE    UBAIX. 


ftoiual.are  aUo  iiivolrvd  in  Ihtr  atrophy.  W«  tiuiyailil  llint  rcinovml  iirix^li 
eyta  iu  lite  ncwboni  Knimul  u  nid  tii  l«iul,  baulw  tlic  aimpliy  of  ib»  tbw 
ImdicB  in  qii«Mion,  to  dJininishcd  ocvipiul  lobo  duv  in  Uick  of  while  hmUct. 
We  may  tberofvra  conclude  dial  iu  Uw  oompk-x  net  of  viviui)  two  oriwntt 
central  unptimtiu  lira  involved  ;  we  insy  epcak  of  iwo  kindn  of  oeuUH  for 
vinioii — lae  primarr  or  lover  vitual  centres  supptiwi  bv  tlw  thr«e  bodiM  of 
which  wo  ara  ({icakiDK.  and  «  iMODdary  or  higher  visiiitl  oeatrr  iupplitd  hf 
tli«onrt«x  in  the  occi|>itaI  region  of  tb«  cerebruni.  And  pxperiineuial  renlti 
ncourd  with  this  view. 

Beli>r«  we  pn>oe«i  to  dimuB  ihoee  reoulu.  one  or  two  prvliminnry  ubwm 
Umm  may  piwra  of  use, 

111  tW  firet  place.  a«  m;  have  prcvionply  urfM.  the  iiiterp«vtrtlii>n  of  Uif 
rcMiIta  of  an  oxperiineiil.  in  vthicli  ne  Iww  li>  judp!  of  eeneory  rfliictik  *n 
far  more  (in<«rtHia  thiin  whvn  wr  hnv«  to  judnco  of  motor  etfeat»,  that  u,  rf 
vouree,  when  ibe  oxiierimcmt  is  conducted  on  iin  animal.  We  can  eatimali 
the  motor  vtttict  'iiituitilAtively,  w«  can  iDCmiiv  and  record  the  contnctioi' 
of  the  tiiuitd<^  hut  in  tvlimstme  n  Msnsorr  rflcct  wo  liave  to  depend  on  wgn 
our  interpnrlation  of  which  w  dii««1  on  annlogi<w  which  may  or  may  not  tt 
niialeadinfc.  \Vc  are  on  sater  eround  when  wc  can  nptH'nl  to  man  biinMtf  ii 
llie  exjwrimentF  instituted  br  dieeaBe :  but  the  many  aiivaiitagiTi  ihu«  Mcnid 
are  ofl«n  more  ihan  con nteri)a lanced  by  the  diflu«o  cboractcni  or  the  cumpkl 
Gon»)niitnnl«  of  (he  lesion.  In  dealiii;*  with  sensory  ef&d*  wc  must  eipM 
and  be  content  for  tfa«  niwent  with  (ytncluMons  Icm  definite  and  mon  UM» 
tain  even  than  thoee  gained  by  the  study  of  motor  efi«cta. 

In  the  arcond  place,  in  dealing  with  vision,  it  will  be  de^irahlv  to  kuo*  tbt 
n)c«iiiiig  which  we  are  attachuig  (<i  tlie  words  which  we  employ-     By  fating 
mw,  Ihni  ifi,  "  complete  "  or  "  total "  blindnew.  we  mean  that  the  movHiMMl 
and  other  aclioni  of  (he  body  are  in  no  way  al  all  iotltieiiced  by  the  aauoM 
of  light  falliuK  on  the  retina.     Of  partial  or  incoiniilete  or  imperfect  riaw, 
tiaiug  liie  w<ira  vifion  in  its  widest  sense,  there  arc  many  varieties:  oailvs 
may  iltuitrnte  some  of  the  defects  of  the  visual  machinery,  re|t*rdn'  ■*• 
whole,  with  its  centra)  as  well  as  its  peripheral  parts,  by  rvlerring  to  cenaii 
defect*  of  vtxion  due  to  cban;^  in  the  eye  itself   The  eyo  may  fall  into  talk 
a  condition  that  the  mind  can  only  apprecinle,  and  that  to  a  varying  ilefiM 
the  dilSuvncc  betneon  light  and  dorknew ;  the  mind  is  aware  ihiu  the  rrtiM 
(or  it  may  be  part  of  (he  retinm  is  Iteing  niitmliiied  to  a  Ivm  or  KnaUr 
dcereCi  but  cannot  perceive  that  one  pan  of  the  retina  is  being  ntiinuUlH  in 
n  dilTerent  way  fl^m  another  part ;  a  sensation  of  lif;ht  is  excilix).  hut  not  ■ 
ni  of  visnal  MOuaUona  eorrMpomling  to  the  seta  of  {wnclln  of  Ininiiuxis  nn. 
which,  reflet'tei)  or  emanating  fnwu  external  objects  in  a  definite  ordw,  sit 
falling  u|M>n  the  cyi-.     The  eye  again   niiiy  fall   into  anotlter  c>iniliticii,  ia 
which  ^ich  aeta  of  visual  scnmlions  are  rxcttcil,  but  on  account  of  diopUir 
imiterfci-tioo!!  or  for  other  reasons  the  several  weiiMttiiinti  are  not  «>t«auiell 
distinct :  the  mind  ii>  awnre  through  the  rye  of  the  esisteiic«  of  "  thngK 
but  cannot  uilcjUHtely  recugniiie  the  cbarncters  of  thnac  tbiii|{a ;  tiw  liimt 
imof^  are  hlurmi  and  indistinct.     And  a  large  nnmbcr  of  grailntvinn  tn 
poMibIc  bdwecn  the  extreme  condition  in  which  only  these  otijecis  srhWA 
prCMDt  tlte  strongest  contrast  with  their  eiirronndings  are  visible  to  a  ofliK- 
lion  which  only  just  foils  nhon  of  normal  vision.    Imperfi-ctioun  of  ihi*  UbH. 
of  varying  degree,  may  result  from  failure,  not  in  the  peripheral  iipparatu*. 
not  in  the  retina,  or  onUe  nerve  or  other  parts  of  the  eye.  but  in  the  cvntrsl 
appMratus;  the  retinal  image  may  be  sharp,  the  retina  and  the  njitic  fibrw 
may  be  dulv  ri-Hin'onive,  hut  ft^ni  something  wrong  in  some  jmrt  or  lAlwroT 
the  brain  t)i4r  vifunl  scnsntions  csoiled  by  ibe  visual  impuwi  may  tail  in 
dittinctncas,  and  that  in  varying  dcgrr*  :  imperftctions  of  vismDt  wlMtbBritf 


I 


I 


irigiit.  in  which  visiin 
I'livrnllr   «poken   of  undfr   lli«   iiol    w 
•tmAti/vjiia. 

If  line  optic  nerve  be  divided,  tool  btindneBs  of  odl'  ryo  will  tvnilt ;  but 
if  onir  ii\*'u-  tract  be  divided,  it  follows  froiu  whnt  hns  been  wid  ubovu  that 
hnlfbiiiidnvM  in  the  oAmspondiiig:  hiitveii  ut'  both  eyes  will  rrsult.  If.  Ibr 
iiutnnco.  lii«  ri^hl  optic  imet  (Ki^.  ^OU,  Op.  T.\  bi-  divided,  llie  U}t  vigiiitl 
tivldii  of  both  eyee  will  be  hloiled  uiil.  The  miui«  condilioD  will  be  brought 
ttltoiit  by  failure  in  the  optic  Irai^t  at  iia  rculral  eliding,  provided  of  <.'ourM- 
ih«  mischief  be  coofiDed  lu  tli«  ending  of  tbe  one  tract.  .Such  a  hiilf-blindiitiM 
or  half-vision  is  apolcen  of  on  hnnianafuia  oT  heminu'ijiia  or  hemiopia :  tlio 
words  lel\  and  ri|{ht  are  tci-i": rally  \ne*i  in  refnruicu  to  tl)«  visual  lieM ;  thiiti, 
left  heiuiunu|Hia  i»  th«  blottiii^  out  of  both  K-lt  vinual  fidda  ihrough  failure 
i4  the  riyhl  ofttic  tract. 

If,  iii»i«iid  i>f  ihf  whole  optic  nerve  boing  dividwl,  oertaiu  bundles  only 
were  cut  ac-rw*.  iinrtial  blindnnu  woiihl  be  the  rtwilt.  a  portion  of  the  vieual 
field  would  Im?  blotted  out.  and  miK^hk-f  limine)  to  a  few  biindluof  ooe  oplic 
tract  would  load  cornvjoindiog  blots  in  the  corresponding  hnve*  of  tlie  visual 
€«lda  of  both  cy». 

Furlb«,  nn  aflirction  <'f  h«lf  the  retina  or  of  a  limited  arva  in  the  retina 
might  iicvur  of  fuch  a  chantHcr  as  to  lead,  not  to  complete,  but  to  |Mrual 
bliodncM^  to  a  bemt  aniblyopin  or  to  a  partial  amblyopia.  Thv  pari  of  ibe 
retina  to  Itfliwtnl  might  be  central,  or  peripheral,  or  a  quadrant,  or  any  puteb 
of  any  ■!/<■,  form,  iind  relative  portion.  And  we  may  further  imagine  it  at 
Inut  iHDwible  that  mischief  in  the  brain  might  be  so  limited  as  to  protluce 
any  of  the  above  partial  eflects.  though  lh«  reliDS,  optic  nerve,  and  Optic 
tracts  all  remained  inlacl. 

The  above  visual  imperfections  we  have  illuHtrvted  by  changes  to  the  peri- 
pheral a|>paratu^  but  there  i»  a  kind  of  ini|)rrleolion  which  we  may  still  call 
a  visual  iMi[>erfcction,  though  it  in  of  purely  central  origin.  Id  a  norma) 
>iate  of  thing*  a  vi-mnl  scnMtion  excited  in  the  brain  is  or  may  be  linked  on 
to  a  cbain  of  jMychirul  evcnl*;  we  often,  then,  spnk  of  it  as  a  visual  i<lea. 
When  we  see  a  dug  the  vinonl  »cnMtion.  or  rather  the  jjroun  of  Mrnsations 
miikiiij;  up  the  vinual  pcriTpiioij  of  the  dog.  does  not  exist  l>y  itwlf,  apart 
from  all  the  »lher  eveni)i  of  the  brain  ;  it  joins  and  aflects  them,  and  among 
the  events  which  it  hi  atl'cct«  may  be  and  often  are  psychical  events;  the 
vivual  perception  "cmeni  into  our  thoughts"  and  modilics  them.  Between 
the  vixnal  impulse,  as  it  travels  alon);  the  optic  nerve  or  tract,  nod  ilji  ulli- 
mate  pvychical  eflect,  a  whole  nriea  of  eveois  intervene  ;  and  we  may  take 
it  fcT  granted  that  the  chain  may  be  broken  or  s|Kiill  at  any  of  its  link*,  at 
the  lairr  as  well  as  at  the  earlier  one*.  Wi?  mav  therefore  consider  it  ptwn- 
ble  that  the  break  or  damage  may  occur  at  the  links  by  which  the  fully 
developed  visual  wnaatiixi  JoioH  on  to  {wychieal  onerationu.  We  may  sup- 
jMH  that  an  objed  m  »eeu  and  yet  docs  U*>t  afliMt  (be  miiid  ul  all,  or  allk'la 
It  in  an  abnormal  way. 

Theae  foregi^iug  coiniiderattomi  emphouM  the  diffimilty  and  unceriainly  of 
inlerprelioi;  the  visual  coDditicin  of  un  aiiimal  which  has  U-cu  rX|>i-rimeutRl 
upon.  Wbet),  for  inslan<-e,  after  an  operation,  an  animal  iwiuo  lo  Ite  influ- 
enced in  ilH  iireviiiuM  normal  manner  by  tbeTisual  cH'rcts  of  external  objects, 
a  moM  careful  twycliical  annlyi<!»  is  often  necessary  to  enabto  u>  lu  judm 
wheUlcr  the  newly  introduced  disrrgard  of  this  or  that  objeel  it  du«  to  the 
■HI*  vumal  denMlions  being  blurred  or  blunted,  or  to  some  failure  lu  the 
nmrebical  appreciation  of  the  sensations :  and  in  most  eases  S4ich  an  analysis 
H  Myond  our  reach.  The  i>realest  caution  is  needtbl  in  draaiu);  conclusions 
from  txperiineiiiB  of  this  kiixl,  especially  iVoni  such  a^  ni>|iear  to  have  been 


H14 


TnH    BRAIN*. 


liiMtil}-  cxrriod  out  or  lioMily  oWrvcd ;  and  we  must  be  coDtoiit  hwe  tndvvll 
00  «om«'  of  thfl  bruatler  fouiiires  only  of  the  subject. 

S  672.  .Since  we  have  iu  this  natter  to  trust  eu  mucb  to  8nalogi«s  with  our 
own  experience,  we  roar  turn  at  once  to  the  monkey  aa  bein);  more  taltRl^ 
tire  than  any  of  the  lower  anunals.  We  have  alrvady  Mid  that  cl«tKll 
escitaticin  of  the  om|iital  curlex  behind  the  motor  reKiou  may  prmlaca 
luovemeiiu.  but  ih«i  ihc-<e  tuoremeuta  arc  in  charaoivr  difR.'retit  rmm  th«a 
caused  by  ^limulaiion  iif  the  motor  r«)(io<i  iMtlf.    In  lUt  maiA  <  lUtka 

nf  partA  of  the  iu-c;ij)ttiil  rcj^ioo,  the  occipital  lobe,  ani)  llu-  au  i  lu,  ftl 

iiiManw.  may  glyc  rim-  to  niovrmciiU  nf  ihr  oyc«,  of  the  fiyvlid*,  w»l  uf  lbs 
hi-nd.  that  L<  ot  the  n<<ck.  all  tht-  movcntt^ltt  ^i  pmiliic).''!  Wing  «uch  ■*  an 
onliiiarilv  (.■oiint^i'tnd  with  vtrioii.  It  will  not  W  prutilable  I"  i*nli'r  herr  rain 
tin;  detail*  poiiciiminE  thi?  t-xact  topography  of  the  rxcilabU'  part*  or  nf  (hs 
niifcial  chnractfirK  of  the  inoveincale  s«  caUcd  I'orlh.  But  it  w  important  Iu 
U'lle  that  thcsr  niovetnculs  are  unlike  the  moveinontu  cKcitttd  by  KlintnlaiMa 
vf  (he  appropriate  motor  area,  insHinuch  as  their  occurrence  is  Oir  b-m  cri 
tain,  they  need  a  Btron;>er  stimulus  to  brinj;  them  out;  when  evokeal  thiT  ar* 
fwble.  Iiein]*  easily  autag^onixed  by  appropriate  stimulation  ul'  the  molir 
urea,  and  they  have  a  much  loiif^r  latent  jieriod-  They  are  not  due  In  mtj 
indirect  stimulation  of  the  motor  area,  ihroujth  "  nsMtciation  "  fibres  oob- 
neotin;:  the  aput  siimulate<l  with  the  motor  area,  or  »therH-i_«e,  since  (btf 
per^t  atler  removal  of  the  motor  area.  Movemeuta  of  tbii  kind  may  aM 
be  niiu&Med  tn  the  Hug.  They  arc  ohvioualy  the  nault  of  iiupulaa  tn» 
miltt-d  in  »oiiii>  ilin^ct  manufr  fmm  the  ortex  Inaome  parb  below,  and  nt 
bo  triki'ti  AH  III!  indiriition  that  the  pari*  of  the  itiries  in  ijuiation  arr  id  mv 
way  r>inii<.-eti:d  wilh  virion.  The  exact  manner,  howpvi-r.  in  whioh  titer  air 
)iri>ij);lit  abiHit  i*  at  priwiit  obscure  The  exphiuation  nf  ihcir  ^n<Mii  nblth 
h  fre(piently  oflereil.  namely,  that  the  stimulation  No  hITivIa  the  i-nriit-al  p»j 
matter  as  to  ^ive  rise  to  visual  fC'iiBalions,  and  thnl  the  ni'ivvRicole  expiw 
these  seusalions,  does  not  aeem  Ml iii factory,  For.  if  i(  !>>.■  p'<uilile  that  the 
KKIB9  chanjtei  whidi  the  electric  current  seta  Koins  in  the  ortii-al  [•'»y  nalUf 
can  repMiluiv  the  |idych!c«l  erenta  which  take  place  in  that  gray  matter  ia 
iht^  normal  uctinn  of  the  brain,  we  ahoiild  expect  Biimulation  of  anyud 
every  part  of  ibe  cortex  to  call  forth  wtme  movement  or  other,  ainoe  it  CUMt 
Ik-  iloublcil  that  every  part  of  the  cortex  i*  in  mme  way  or  other  eDffiffd  to 
mychiojil  operati<>n:i,  nnd  that  cvcrv  piyehical  phaae  tend*  to  express  ibrif 
in  niovemciit.  Whert^ny,  ontiiido  the  motor  region,  with  tbe  exoeptiMiC  Wl 
Br<*  now  dixTUwing.  tlic  cortex  i*.  as  we  have  •wtn, ""  inexritable."  and  ewn 
within  the  motor  region  itself  the  escitnble  sub«lnuce  is  ncatteretl,  wilh  m- 
cnuiog  segreealinn  as  we  advance  aloni^  the  animal  lu'ale,  amooj;  iuexcitahit 
aubitanoe.  When  we  apeak  of  the  region  ur  nubitaniv  lu  inexci table,  ve  4o 
n»i  mean  thai  the  electric  current  pn)duces  no  vlTeet ;  we  nnlv  mvan  that 
the  e6^i-t  is  not  manifested  by  movement :  the  real  diiren^ncv  ItctwecD  thr 
ext-itable  motor  re|;iou  and  the  inexcitable  rest  of  the  cuitcx  in  pnibablj 
thai  in  tbe  several  mofir  area*  the  current,  playing  upon  the  beginning*  of 
the  pyramidal  fibres,  ia  able  to  inauKumte  simple  motor  impulw' or  wiar 
thing  like  them,  whemui  elaewhcre  the  molecular  cbangiv  indiioeil  by  iht 
curreut  arc  loo  oonfuKcd  to  reach  tJieir  normal  expression.  Thor«  oao  lac  n<i 
doubt,  of  ODUtw,  that  molecular  change*  in  this  or  that  part  nf  tlie  bnin, 
set  going  by  proocmes  other  than  acltial  visual  impulsee  aloog  il>e  uptie 
nerves,  may  <^ivo  rise  to  visual  sensation* ;  and,  aa  we  shall  see  in  dealiRf 
with  the  seikMs,  the  subject  of  lucli  "  vubjci^ive"  aenuitions  is  unable  to  di*- 
tinguiab  them  from  sensations  uf  "objective"  origin;  but  it  is  at  leari 
unlikely  thai  ihe  coaree  disturbances  started  by  a  letaniiing  current  *h"Ul>l 
lake  Hich  a  definite  form.     Morenver  lh«  vi«w  in  *iue9lion  b  disproved  liv 


VISUAL    AND   UTntCR    SES'SATIOXS. 


M5 


I 


lb«  evperinteuUil  mtill  ilmt  ilie  aaiiie  luoveiiieDta  art'  hiviut-ht  aboitt  hWu 
thi-  eortex  n  paTed  aixir  ami  ilie  clectruclcs  nre  applied  to  thi.-  hu i>jnt-i.'iit 
whiir  nuiiier.  Tbis  reaiilt  >iitj];;e«i(i  tlie  exiatencv  of  ertirrriii  (racUi  urbiiuill^i 
tif  M  i|ieci«l  kind,  ilifleriii;;  fn>ii)  tbose  of  tlie  pvramidul  kind,  itiough  like 
them  making  cunnecltonv  witli  the  ooulnr  utui  oiltvr  m\]»ekti :  we  hnvt,  liow- 
evt-r^u  yel  no  ullicr  cvideiico  of  iiucli  Inict*  vx'ti^iag. 

%  873.  Tbc  rctullii  <if  iTiiioval  vi'  the  cortex  uUo  iiiipjHtrl  ttio  mnfl  g^DCnil 
caitclukinn,  iboiigli  (kcre  it  much  discordance  untoog  tbi.-  various  (ibMrwrs, 
bdlh  ai  III  tlw  pnrrictilar  result*  nnd  cspccuiilf  mt  to  their  iuifrpretAtion. 
broftd  tavt  comts  utit  in  all  thr  obcerration«,  namely,  thm  tbe  rrmovnl 

or  injury  to  tho  bind  rrgion  of  iho  cnrtvx  always  prxHJuvce  Butno  dislurb- 
of  vHton,  and  pmduora  dislurbnnct!  of  Ttcioa  more  surely  and  lo  n 
prvaUr  exttoi  tbun  dom  injnr}*  to  or  removal  of  any  other  region  of  tliv 
cortex  ;  l>ut  beyond  this  broad  laot  there  i»  mnch  dieput«,  and  we  niuet  bi- 
K'  litem  here  with  n  very  brief  sinlemenL 

In  tbc  monkey  some  observere  have  found  that  n-moval  of  Ihe  occipital 
lobe  on  one  side  (the  resion  marked  "  viuon  "  in  l-'igs-  -0-1  and  *J05)  caiiwil 
betniopia,  the  elf^  on  the  visual  Heldfl  lieinfc  a  cnMsed  one ;  when  ilie  right 
lube  wBM  removed  there  was  blindne^M  in  the  leA  visual  fields,  that  ia,  iu  the 
right  halve*  of  the  reiinaa  of  both  eyes;  in  other  wordn.  the  viaual  impulst-n 
|iMiiiin|j  uloug  ihe  right  otitic  tract  failed  to  produce  l)it.'ir  iiMial  elfect,  so  thai 
tbe  animal  aungaraed  objects  on  Jlii  MX  baud  sid«.  We  may  remark  tbnl 
the  decuseation  of  tbe  optic  nervo  iu  the  muukev  ih  wry  Minilar  to  ihnl  iu 
man.  When  both  occipilnl  lobe*  wen  removed,  tutnl  bliiidncM  r«iulted. 
But,  and  thiii  is  moat  ini|Hir(aHt,  not  only  wan  thi?  liemiopia  canwd  by  the 
nrnioval  of  one  lobe  ImiiMcnt,  but  alwi,  arcordiug  to  aonic  oliwrveni,  the  lent 
vi»ion  returned  after  the  total  removal  of  both  IoIkw,  though  xomo  impair- 
tnrnt  might  be  noticed  lung afteraard. so  lung  in  fact  ao  the  aninnd  *ae  Kept 
alive. 

In  the  bands  of  other  observera  destruction  of  tli«  angular  gyrus  of  one 
side  (Fig.  ^20t^)  has  led  to  hemionia,  failure  in  the  left  (or right)  visual  fields, 
indicaling  failure  iu  tlie  central  endings  of  the  right  ior  left)  optic  tnct. 
Wing  cfliKeil  by  removal  of  the  rigbl  (or  IeA)gyrui(.  and  <le£tructiou  of  lioth 
angular  ^yri  has  led  to  total  bliodnew,  not  only  the  heiutopiu.  but  tbe  total 
htiixliieM  being,  however,  apparently  trauaitory.  And  cases  have  hern  ob- 
H-rvi-d  in  which  the  transient  blinduen  due  lo  removal  of  the  occipital  lolie* 
hwi  l<r«D  succeeded  hr  )<erniai>ent  hemiotiln  up<tii  the  sub»ei|ucni  removal  of 
tliv  angular  gynu.  Indeed,  the  general,  but  not  uniform,  tendency  of  tlie 
nany  experiments  which  have  been  made  in  to  connect,  in  the  monkey,  botli 
tbe  occipital  lobe  and  the  angular  gyrus  nith  vi*i»u. 

In  the  dog,  removal  of  portiotM  of  llie  ocripitsl  mrtex  have  also  led  to 
p«irtial  and  tninnient  blimturw,  or,  aceurdlDg  lo  Mime,  to  |>ennaurnt  blind- 
nest;  but  thi^  ilifficulties  of  judging  the  vixual  condition  of  a  dog  an- vciy 
considerable,  and  his  vinion  ts  so  dillbratt  frt>m  that  of  man,  so  much  lt»s 
binocular,  for  in»tunoo.  than  hi».  that  it  would  not  Ik  profilablc  to  relate  at 
length  the  resulls  oblaincd  in  ibe  dog  or  to  diwuss  the  cooclufiona  which 
have  been  derived  from  ihcm.  We  will  only  say  that  some  obterven  have 
lieeu  led  to  think  that  the  lateral  part  of  the  retina  i«  coiincclnl  with  Ibe 
lateral  part  of  the  visual  occipital  area,  the  front  part  with  tbe  front  part, 
and  mi  on,  the  rdiua  lieing,  as  it  were,  projecletl  on  tu  tbe  occipital  cortex  : 
but  ibv  faciD  are  not  clear  enough  lo  make  it  worth  while  lo  dwell  upon  tbem 
Wre. 

In  man  clinical  histories  hi  far  conform  to  Ibe  Te»ults  of  experiments  oil 
the  monkey  oa  to  aaecoiate  tite  occipital  cortex,  and  more  particularly  the 
ctineus  (irc  ITiga.  207  and  209),  with  viNon.    They  liave,  hoiiever,  raised  a 


846 


TTtK   BRAIX. 


point  on  u'hiub  w«  have  nol  yet  touched.  lu  llie  i.*X|wHmeata  nn  thr  innnkM 
((uotci)  abuve,  t1ie  reoult  (putting  stide  iruuieut  elTecta  <)<■»  prob*bly  i'> 
"  «hnck  ")  «r  interferenoe  wrilh  one  aide  of  tin!  brain  wk>  huiuiojiiK ;  und  ihi* 
in  urliat  we  iniKkt  expect  from  tlie  auatomiciil  nUtionN ;  iht?  uplic  tract  gm 
Mtrnight  to  lh«  K^iuiiiiil  mHM«  ot  iu  own  dde,  wtil  ihr  oplir  nwliMaiB 
puKS  from  thoM  iDMwa  to  the  occipital  corux  of  tbr  name  aitle ;  tlitn  \t 
no  dwntaition.  MV«  of  lh«  fibres  at  tbv  otitic  norfc,  or  thry  piui  inia  ibr 
optic  tract  at  tiMP  chtuma.  (Ninical  )iisl<on«  tench  thr  Mme  Iflnooa  «■  them 
experiments  on  animnltt:  lo«ion.'>  limilod  to  th«  occipital  lobe  ht\«  fori 
eyniptom  heniiopia:  anil  tbi«  i>  Mud  to  be  capcdully  the  rivult  of  tnbchirf 
liiniied  to  the  apex  of  thtr  iiccipital  lob<^  tJint  is,  to  the  cuoeus.  Hut  «x)itri- 
nwotd  on  iD'inliers  hnvi?  been  niiido  in  which  destructimi  of  oDe  uwular 
grnia  ba«  produced,  not  hemiopia,  hut  cnimcd  blinduen  or  crowed  aniHTih 
pia,  that  U  to  sar,  ha*  ntTttelcd  tno  whiile  t)f  the  retina  of  oD«efe,U)d  tbattW 
cnmed  eye.  the  eye  of  thi^  eame  aide  not  being,  or  heinj*  Ruppoaed  not  In  li«,il 
>ll  afl'«cte'l ;  similar  results  have  al§a  been  stated  to  fullow  u|hju  removal  <tf 
on«  ocd]»tal  lobe.  Aud  a  few  clinical  cases  have  Ikeen  reoorilerl  in  whieb 
diseiMe,  etpocially  of  the  aneular  gyrug,  seemed  to  affect  thr  vi«iuo  of  tk 
whole  of  th«  croaied'eye.  (It  must  he  reinemhered  thai  the  aiiKular  grrw 
of  man  corrwponds  ti>  ii  part  only  of  the  whole  augjular  gyriin  of  tlie  munVn. 
Cf.  Pit;.  '20^  with  Fig  2<>T.)  Si>m!  authoH  have,  in  eocardanoe  with  tliM. 
put  forward  the  tbeiiry  that  the  occipital  lobe  serroi  as  a  oortieal  centre  br 
the  optic  trnct  of  iixiwu  side  only,  aiul  so  fur  iine-hatfufwch  retina,  while  ii 
fri>nt  iif  thi«  on  the  angular  gyrua  it  a  oentn-  in  which  hotli  ojitic  tracts  ■» 
rt-prr^nled.  But  the  clininal  hiitorie«  hearinjc  on  thi*  point  oiDlM  b* 
rnguried  as  wholly  ttti«factory ;  and  with  rvfvrcnce  If  the  experimeiHal 
t«*ii1u  we  may  once  more  iiuisl,  and  the  warning  appljv«  perhaps  with  nv- 
tjoular  fbm-  to  these  experinienta  on  vision,  on  the  dan),'vr  «(  ooofoaiiiliDf 
lltose  immediate  efTects  of  operative  inlerfereiiw,  which  an  of  the  oatniv* 
'shock  "  in  till-  wide  sense  of  that  word,  with  tliose  pure  "< left e ion CT "  iil» 
Qomena  which  are  alone  the  outcome  of  the  loss  of  the  part  rcnuivut).  It  ii 
diflleuU  to  Tivi*i  the  cunclusiou  that  much  of  the  tnuisit«ry  blindnnM  whlck 
u  observed  in  thwc  experiinenta  belongs  to  the  former  L-aU-gory,  lliat  iW 
effect  b  transient  because  It  b  of  the  nature  of  shock,  and  nut  Iwcaitw  tli 
luM  of  faculty  U  supplied  by  some  other  cortical  area  heing  HuhMi|i»Bally 
gobrtituled  for  the  on"  removed.  In  the  dog,  injury  to  (ho  fmnU)  region  ef 
the  cortex  unaccompanied  by  any  secondary  mixcltivf  in  the  occipital  ngino 
ha*  IctI  to  inipaireil  vision:  and  thin  was  probably  an  iiMtaDoe  of'stiitck." 
lor  we  hav«  no  other  reiuon  to  connect  the  fiODta]  r«vioD  of  Ihv  uirtex  with 
vinoD.  We  must  be  very  cnn-fiil  in  drawing  the  coocluriin)  that,  becaase  u 
operation  produces  iraasicnt  hlitidiiiw,  tlie  )«rt  operated  oo  haa  ■  dlna 
•hure  in  vision;  and  we  may  well  hMitnte  to  accept  the  view  that  the  wbole 
retina  t<  repreKoted  in  the  crossed  hemtsohera. 

Id  codcIuhiou  we  may  say  llint.  when  all  the  many  results  which  have  lien 
arrived  at  by  fxjieriinent  or  by  clinical  obscM'alion  are  duly  weighed,  it  will 
h<?  felt  that  while  the  evidence  for  tlic  occipital  li^,  eBi)ccially  the  cunem, 
being  coiK-nrnnI  in  tite  matter  is  ooiivincing.  we  cannot  in  the  preacnt  itai* 
of  otir  knowlcflgc.  dogmatically  exclude  the  angular  gyrvs.  aud  that  heac* 
the  only  clear  and  consbttent  statement  which  can  be  mode  with  any  eqa- 
SdeDoe  b  the  hrnad  and  Kinipte  one  that  the  bind  region  of  tiie  cortex  m  h 
some  way  intimately  cuncvrned  in  vision. 

§  874.'Siich  an  attitude  becomes  all  the  more  ueoeuary  when  we  ask  gnr- 
selve»  the  igiiestion.  What  b  il  wbich  actuallr  takee  place  ia  the  corlei 
duriiij^  vision?  Are  we  to  conceive  of  il  tm  if  a  vi*uiil  impulse  set  guttt 
ailing  the  fibres  of  the  optic  tract  underwent  n»  iwciitial  cban^  until  it 


VISUAL   AM>   OTHER    HBNSATIONS. 


8i: 


tliA  <-ortex.  u  if  it  lli*i«  su<I<lco1y  developed  Iiiln  u  "  vixuitl  (m*u- 
'  We  can  hanlly  JU)i|)uie  thti.  Belween  the  (.-orlcx  itoil  ihr  vgilio 
the  lower  viiual  ceutrea,  the  teciueiilal  iqium*,  inivn-euc ;  aud  we  cnn 
llr  ■ii|>paBe  tliiil  imerfereDc«  uitlt  lliG«e  tiDdiea  (tTioducvs  tli«  «antc  tSect 
▼uiui)  &!>  Rimpte  ieditiii  of  the  uplic  trmt.  We  have  ic-n  in  ■  previou* 
•rrlion  ihat  the  ttog  nnd  the  hird  cerininly,  luid  nrvordiag  |i:i  •ome  »b»ervvn 
■Uii  ihi-  rabbit,  Arv  in  the  abtwnot!  of  the  ixrehrnl  homuphorce  not  totally 
',  Ihfir  iiwvt'uieDln  bciiiji  ^iiiilnl  )>y  retinul  iinpnwione;  nnd  cum  are 
d«d  of  tb«  dog  imtig  ohviiiiiiJv  *|UI  i^iiidwl  in  eotm-  nciHurc  by  rotiniil 
after  the  Md^>itul  lu^w  hml  b«eD  wholly  or  almoai  wholly 
ramovcd.  And,  though  thi>  i»  a  nintlcr  at  pnKcnt  ouI«ido  exnct  biiowkdge, 
aiul  I^MUffh  it  ii  j>crhn)i«  iHwhle  Tor  «imple  aflbrcnt  impulsoi  to  dvlertnine 
area  Oi>mpV-x  nmvt^tiK-ot*  without  Lhu  interveniioti  of  "  roDB<.-iuusiies4,"  irv 
are  pmbiihlv  juMilir'l  in  iiwuniing  thul  (he  simple  visuni  impulwM,  trBvellinfr 
along  ih*'  fibrw  of  the  optiir  iriK't.  undergo  impiirtnnl  tniD«foriiiatioiu  iu  th« 
tapBCDial  masMa.  and  that  th«  changes  which  are  propagated  aloDg  the 
flwflfl  oT  Ibe  optic  radiation,  constitute  something  quite  dilferent  from  the 
itDpuIsM  along  the  optic  Irnct  or  nerve. 

Judging  from  the  noulogy  of  the  oiolor  region  we  may  probably  aasuai« 
that  in  visiun  llie  cortical  events  are  ptiychical  in  nature,  and  that  ihefunctioQ 
uf  (he  optiL-  indiaiion  is  to  fumiali  whni  we  may  call  crude  vuual  eeouitionii 
for  further  |)tiyi.-hical  elaboration. 

Ntir  awfl  this  view  oomfiel  ua  to  supixxte  lhat  injury  to  or  rciDoral  of  ihv 
cortrx  niuat  |lrudul^e  only  psychical  blindneaa  or  {MTobifisI  impairinvnt  ol' 
Yiat-in,  tbiiufth  thin  |ioinc  has  probably  not  beeii  Mumclontly  lieUI  in  view 
during  the  variou*  ex|>eriiiientj»,  nutTioii-nl  care  not  having  bcvn  taken  In 
iDiDc  biiw  liir  the  litindniaa  wan  purely  ptychical.  Bearing  in  mind  tbc 
iMHtinn  following  upon  IminnK  of  ihc  occii>i(al  iu>rt4:x,  and  the  br- 
ing cflcctK  of  any  o[tcnition  on  (be  brain,  we  may  euppoae  tlwt  injury  to 
cortex  nReclx  the  lower  centres  as  well ;  and  B'>me  of  tho  tnnaJeut  ini- 
IMinDciil  of  vision,  on  which  we  liave  ju«t  dwell,  may  perhapa  he  explaiued 
ua  (he  eirect  of  ihe  cortical  injury  on  lite  lower  centm. 

Although  the  mailer  is  thus  in  many  of  ita  details  at  present  ou(«ide  our 
Vftcf  koow  ledge,  we  may  probably  conclude  ihal  in  the  complex  act  ofcorn- 
j>Iete  vi*io(i.  while  pari.  efi|>ecially  the  more  psychical  pari,  is  carried  out  in 
(he  ci>riex,  moie  particularly  of  the  occipital  region,  part  is  afioomplldied  in 
ihe  lower  centres,  Ibe  lei;m«nial  maasta.  As  to  the  several  fUnctitmi)  of  the 
ibree  inawea,  we  know  almoA  alMolutely  nothing.  Kleclrio  stiraulattnn,  and 
it  ia  *ud,  luecbaiiiiral  stimulalii>n  alM.  of  the  anterior  corimra  •{iimlrigcmiiia 
■  iu  uuunmaia,  or  lh«  upttc  hibt-i  in  lower  auimaU  calln  fdrtli  luuvcim^nla  of  (be 
^^Hl  and  of  varioun  purL>  <>f  the  biKly  :  and  ruiuoval  of  th«ni  oauaca  blinit- 
^^Hi  and  in  vome  cami  Una  of  <M>unlinat)iiu  of  movements.  Our  knoirlclgc 
■  III  th«vc  points  iii  not  very  exact;  but  fnmi  lh«  alwive  facU  aa  wall  as  fr<>m 
the  ■■i>nno:lti>ii9  of  thu  nnlcrinr  corpora  ouadrigvwina  with  (be  porta  of  the 
brain  behiixl  wr  may  p<w*iblv  NupixMHr  tbai  th<s«  iKHlica  are  nora  miecially 
cniKCnivd  wilb  the  part  viiiual  im|>ul>ca  play  in  detvriuiaing  the  coordination 
of  iDorcmcntc^  Wr  must  reniombi^r,  liowercr,  that  all  three  maam  ara  con- 
aeetad  with  lh«  cortex,  aiul  probably  all  tlireo  play  a  part  in  vcrion  even  of 
111*  higbcat  paychical  kind, 

StRMfMNu  (^  Sm«U. 

i  87S.  The  olfactory  nerve,  wbkh  ia  undoubtedly  the  nerve  of  smell,  itanda 
like  Ihe  optic  nerve  apart  from  the  real  of  the  eraoial  nema;  and  a  few 
wordi  H  to  ita  auuGture  and  relaUons  will  be  ntemmij. 


THE    BRAiy. 


Lj'ing  'Jii  ibv  vnilml  «iirluco  of  Um  niitc-ridr  rogioi)  (if  i-it<:h  hriuiapbcA. 
•  m  citch  side  of  lhi>  anterior  liBMiro.  k  mod  tlic  (illiirtnrv  Itiilli,  vrliirh  b  pro- 
longed diret'tly  linckwiird  tie  the  olfiu^Uinr'  Imcl.comiiiR  aiiiHin-iitly  In  kd  ml 
where  ibe  liim]  mnr^Hii  of  the  froiiliil  lotw  iibuto  on  Uit-  nntt'rior  ixTforkb*! 
ttMCA  in  ttie  Hoor  of  thi>  Irani  pHrt  uf  ihe  thifl  rvtiiricle.  Tbp  l>un<lla  at 
fibrm  forming  the  nlfnctory  norve  nroper  »j)ring  from  lliv  bulb,  whi<-h  is  cbtk 
iniRiMliate  c«rebml  origin,  both  uitlb  und  tract  being  really  pnrts  of  the 
cerebrum.  Jual  as  the  fure*braia  budi)  otT  on  each  side  the  oplic  vesicle  U 
form  theopliL-  nerve,  so  eneh  cerebral  vesicle  buds  of!  an  olfaclory  reride, 
rhe  front  part  of  uhioh  becoraw  ihe  ivmnded  bulb  aud  ih*  remaiuder  Ihe 
rounded  Irigonsl  Iracl  or  |)eduoole  coDuectinK  the  hulb  with  the  hetuispberr. 
Ill  man  the  original  cavity  of  the  vwcle  is  ooUtcTsted.  beiii;;  filled  up  with 
neuro];lial  gelatinous  nuhi^tuuci.',  but  iu  llie  lower  animals  reiimiit^  an  a  liiitai 
apnoe,  ^e  ventrii-li;  uf  the  olfactory  tract. 

The  bulb  is  a  spvciallKed  mataof  gr«y  nuttier,  formini;  a  aorl  uf  cap  lollw 
eD(I  of  the  tract,  and  prwcnia  somo  analojtie*  with  tlie  corivx  nf  tlie  ImbI' 
sphere.  Along  the  middle  line  Ikii  the  core  uf  neuroglial  g«latioou>  mth- 
•tance;  but  the  side  uf  tlic  bulb  ilorxil  U>  ihiit  oire,  in  i-onlait  with  tbr 
hemitf^ere,  u  much  le«  devirlnpi'il  ihiiu  ilitt  tti<le  lying  ventral  l»  th«  oort-. 
next  tu  ihb  cnbriflirm  plate;  nud  wc  may  confine  aunwlvM  to  lb*  vmirkl 
portion.  Next  Ui  ihc  nciirogliiil  core  lie>  u  lavin-  of  longitudinal  mtidalUlrd 
tibn.01,  with  which  arv  niin^lpfl  mmc  ncr^'c  will*.  Thi»  layer  which,  Ibnnnh* 
beginning  of  the  tmct  inside  the  bulb,  ii  ihinniatt  al  the  ruund«d  frvnl  «i- 
tremity  nf  the  bulb  and  gmdunllv  thicken*  bnckwnnl.  Next  tu  il  liM  a 
"  niicJi.iir  "  layer,  compowd  of  small  nuclear  cells,  arranged  to  ii  Urg>-  rxMI 
iu  loD^tudinnllydi^pcwed  rovs.  Fibrre  from  the  proceding  lay^'r  |«« 
betwcwD  the  groups,  which  are  moreovvr  ecpnrntcd  by  interlacing  bundlvsf 
libref^  >'ext  to  tnis  layer  comis  b  eomewbiii  thick  one,  which  perhaps  nn 
be  compared  to  the  molecular  layer  of  the  cerebellum  or  to  the  pyramidal 
layers  of  the  cerebrum.  It  in  coiufHiiied  of  a  niole«ular  gruund  «ubaiaD«c 
partly  neuroglial  in  naiun.*,  traversed  by  numerous  fibrils  and  fibres,  nan* 
i>r  thti  latter  being  of  the  6ne  medullaied  kind  ;  it  also  cnntaiiu,  in  no  Inrp 
number  iu  man,  nerve  cells,  some  of  which  from  their  triangular  form  SM 
tapering  branched  procc«He«  are  not  unlike  the  pyramidal  oelh  uf  the  wrtei. 
TIk-  larger  of  these  cells  are  generally  found  near  the  nuclear  larer.  Nut 
Ut  ihi«  mulecidar  layer,  or  "  gelatiuuus  layer  "  a*  it  i«  someiimea  «alled,  eono^ 
still  working  outward  Inward  the  aurfuce,  a  cbanu-ierintic  layer  iu  which  are 
found  the  "  olfactory  glomeruli ;  "  oml  oni>idi;  tbi*  is  tbe  luyi;r  of  nllactiirf 
Itbrcs  pni[)er,  that  ix  to  say,  tibns  non-nitMlnllalod  (S  70)  hul  bearing  in 
obvious  neurilemma.  Tht»e  olfactory  1ibm<  are  arrangeil  in  a  closettl 
plexus,  anil  bundle  of  ftbriv  gatliered  np  from  the  plcxuN  ■(  inlvrvaU  pi^rot 
Ihc  pin  nialer,  which  invent:^  trie  bulb  anil  furnishm  it  with  lui  ample  lupplf 
of  blooilveMels,  to  form  the  olfactory  nvrt-c  proper.  Tlw  strmttinr  of  IM 
olfactory  glonH-ruli,  which  arc  nliout  UM  mm.  in  diaioMCr,  has  wrt  T«t 
boon  fully  made  out;  ihry  nr«'  describrd  Bf  Ix-ing  formed  by  cuils  of  bit 
olfactory  fibres  with  small  cells  and  bloodvcnwlsiatonipennd  among  the  rail*; 
ill  the  lower  anininls  a  finely  eninulnr  grouiul  subauuioft  is  proeetit.  Flbm 
from  tbe  layers  benvtilh  have  been  traoe^l  to  them.  We  may  perhaps  ooiiim 
that  they  serve  as  the  immediate  origin  of  the  olfactory-  tibres;  but  lIioT 
exact  notations  to  the  other  layere  of  the  bulb  arc  by  no  means  oleftT. 

The  tract  is  compoeed  partly  of  longitudinal  Hbres,  wilb  which  are  miBgU 
nerve  cells,  and  partly  of  neuroglial  gelatinous  subaiADce.  Tbo  fibres  b^ 
in  the  bulb,  which  apiieaiv  to  serve  aa  a  relay  between  tbein  and  the  fltini 
of  tbe  olfectory  nerve  proper :  and  while  some  appear  to  end  in  <«IU  in  the 
tnct  itself,  others  are  continued  oil  to  tbe  end  of  tlie  tract,  being  joined  by 


VIStlAL   AND   OTHSB   SENSATIONS. 


S40 


I 


I 


I 


I 


9  taking  origin  nlong  lh<^  tnirt.  Wc  niny  compiirc  the  Iiiil1>  »□<!  tho  tract 
l<>  a  fwrt  or  the  reiiuu  (bh  n«  iJiiill  «u«,  n  purl  cil'  thi;!  rvtiiiii  <uriVM}H)n(la  to 
the  iitfactiiry  miicnUH  n>i-mt)ran«)  nu<l  tlu^  ojilic  ni^rvv. 

Th«  donal  nurfucv  <>(  the  tract  k>  itilhcixiit  tn  iinil  continiious  nith  lb« 
Mibatuwe  of  the  cerebnU  bcmwplicrc.  in  ■  eroor«  of  which  it  lies,  hut  tho 
tract  may  be  enciMderecI  a«  iDdvnriidciit  of  tho  Itonii^phfre  until  it  rmchu  its 
dkd,  at  which  il  hrcnk*  up  iiitn  Immls  of  fihivs,  sjHikcn  ofao  iti  "roota,"  Tho 
mnu  c<>iu]>icu<iUH  of  ihciw  is  it  liitcml  ono,  which  ewccpiug  Internllvncnwi  tho 
ftnt«riur  pvrfDratril  i>p(u»,  at  the  mouth  of  tlie  liMuro  of  Sylvtii^  mny  be 
InK^  to  the  nuctcti)  amygdnlti;  (Fig.  194,  .Vb),  nn<I  the  junction  of  this  with 
tbe  hip|Niciini)iBl  or  unciniitc  gynu  ',Fig.  '20N)  in  tho  Icmjionil  lobo  of  th« 
heiui9|>befv  of  the  anmo  liilc.  A  much  smnllor  laoilian  one,  which,  hon-ever, 
in  aome  of  tbc  lower  unitnnU  ia  largo  and  coiupicuoufl,  tnkce  a  median 
iltrvctiou,  pOMca  into  the  anterior  commiMtiro  ($  ff'ifi)  aiid  ta  rtacbes  th6 
olfnclory  tract  of  the  opjioxito  side,  Uther  smnll  ruota  have  abo  beea 
■leicribrfl. 

S  676.  In  many  animals  ia  whom  th«  senw  of  nnoU  is  ncuto,  a  portion  of 
the  nirtfx,  knoirn  as  ibe  "pyriform  lobe"  or  "hippoetimpal  lobule,"  and 
which  is  anatomically  continuous  with  the  front  end  of  tbc  hippocampal 
gyrua  (tho  part  to  which  the  name  UDcioale  i;yrus  ia  ofleo  restrieteu  i, 
acquires  rvlniivcly  large  dimensioDs.  This  and  tbe  niintomical  relatious  juU 
HKniioncd  would  lead  us  to  suppose  that  a  part  of  the  cortex  which  b  cou- 
limious  with  the  front  end  of  the  hippooanipal  gyrus  is  in  >om«  way  oon- 
ncvtml  with  «uell.  The  argument  from  comparative  anatomy,  however,  ii 
oDo  which  must  be  used  with  otutiuD ;  einc«,  Widea  the  great  difficulty  of 
determining  the  bomologiea  of  |>arts  of  the  brain  in  dilferent  ajiimata,  rela- 
tive iiicresM  in  the  part  in  ijueBtiaa  mifcbt  be  correlated  to  other  thiniits  than 
the  power  of  smell,  and  might  be  determined  by  cirtumstancce  having  nu 
reJaiion  toamell. 

The  esperinHntal  cvidenoD,  though  on  the  whole  it  girai  support  to  the 
Tiew,  it  conflicting:  and  when  tha  dlfflcultv  of  deierniiniiig  whether  a 
"duuih  animal"  cau  or  caiiDOl  amell  it  bomc  lu  mind,  thii  will  not  Iw  won- 
derc-il  ai.  Tlie  obavrTitliim  that  electrical  stiiuulatinn  of  thn  region  ifl  flues' 
lion  givt*  riw!  to  movt-nK'nts  uf  tlic  no*triU,  n'lii<'b  have  liecn  iuterpreieit  aa 
tnithitg  in  rexponn  to  subjective  olfactory  scnMilioiu,  caiioot  linvc  much 
aeight;  ami  while  aotuc  obwrvcni  haw  found  that  tlie  removal  of  this 
part  of  tli«  brniii  deatroya  the  senM  of  smell,  others  hare  obtained  nrgatire 
rtvulla. 

Thi- fi'w  clinic-nl  hiittorii«  which  hear  iipiui  the  matter  arc  perhapa  mor« 
tnutmirlhy.  Tlieiw  seem  to  xhow  ihnt  a  Wioii  involving  the  cortex  of  this 
ragioti,  but  leaving  iha  olfactory  bulb  and  tract,  as  wvU  iia  other  parts  of 
the  brain,  intact,  may  d«etray  or  greatly  impair  Miiell.  And  we  may,  per- 
haps, give  particular  weight  to  the  caws  in  nhieb  epileptiform  atlack»,  pre- 
OHKd  Dy  an  "aura"  in  the  form  of  a  peculiar  smell,  linro  boen  aa«ociat«d 
with  disenso  limited  to  this  region;  for  the  phononKoa  of  "aura"  seem  to  be 
cnnneelcd  with  cortical  proceaace. 

Though  the  evidence  on  the  whole  goes  to  show  that  the  cortex  at  the 
front  end  of  ibe  hippocampal  gyrus  is  especially  connected  with  smell,  and 
wa  have  so  marked  it  in  Vig.  itIU,  yet  the  whole  matter  stands  on  a  aoios- 
what  difl^roDC  footing  from  tlte  sense  of  sight.  In  man  the  relations  of  aniell 
to  the  olber  operatiuns  of  the  brain  (thotigb,  as  we  shall  we  in  dealing  with 
the  seitsea,  somewhat  peeulinr)  are  far  more  limited  than  are  ibuw  of 
TBion,  aiMl  (be  psychical  development  of  simple  oUaetury  seusaiium  ia  ex- 
tremely scanty. 

M 


650  THE    BRAIN, 


Seiuali»iu  cf  Taste. 

g  677.  This  special  sense,  ibough  «o  closely  lUBOcialed  with  noell,  bUim)), 
togelbcr  wiih  the  special  eeuse  of  heariug,  od  x  ditIer«o(  footini;  from  the 
two  jirvciiiling  special  aens»,tUDce  Itie  nerves  ooa<:enie<l  Iwlong  to  ibe  ale- 
gor^  of  ordiiiiir^  cranial  nerves,  and  we  lack,  in  reference  to  then,  tlie 
nnuioniiuil  leading  which  is  ulfered  to  us  in  the  case  of  the  optio  and  olbo- 
turv  iiurvfi^ 

\Vc  shall  tee  in  dealing  with  the  senses  that  tlie  fifth  nerx-e  and  tlte  glcoM- 
ii)i«rjng«al  nerve  buve  been  ci>n*iden!d  as  nerves  of  taste,  but  that  the  inaiter 
isonevubjcct  to  <-i>n  trove  ray ;  thu  giiAtatorr  fuoctJou  of  the  6tih  is  attributed 
to  the  pociilinr  choriU  tyni|iiini  uuctc,  iuiA  otlMf  (luestioDS  hare  been  raissil. 
Whatever  view  we  luke,  hnwtver,  the  nervet  of  lo.ite  nre  onlinarjr  cntnial 
Dcrvra,  nad  w  have  n<i  uiiatninical  guidance  as  to  the  fihrM  uf  i;ilher  of  ihs 
n1>ovc  two  iiurvi'ii  makiiiK  «pei-'i)it  ci>niH'cti<>ii»  with  nnv  part  uf  ihc  enrtcs. 
Though  iu;nfali(iuii  uf  tHHtt?  i-tiler  largi-ty  into  the  life  iif  Biiinmlii,  and  ioilnd 
of  nifin  hiinnvlr,  nv  have  no  Mitixfartory  indications  which  will  ennhle  as  to 
Goiinvct  lliii)  Kpc'ial  h-hm;  with  any  part  of  the  cortex  ;  the  view,  ind^'tid.  Ihs 
bven  put  forward  that  xvinc  part  of  llir  rortes  in  the  lower  portion  of  lb 
tempiiral  lobe,  Dot  lur  from  the  ct-nlro  fur  imcll,  nrvm  as  a  centrr  lie 
liuu-;  but  thu  arguments  in  favor  of  this  view  are  not,  as  yd  at  l«sM| 
convincing. 

SenMiiont  of  Hearing. 

^  678.  The  cochlear  division  of  the  «glilh  or  atitlitnry  oern  nij  k 
nftiiinieii  to  be  a  nerve  of  the  special  sense  of  hearing,  snil  of  that  alcw; 
the  vf^tibuUr  ilivUiou  serves,  as  Ke  have  seen,  for  other  functions  than  \iam 
of  hearin;^  (§  ti-lH),  but  as  we  Bball  urge  in  dealing  witJi  the  senses  U  nut  tt 
be  regarded  as  whully  useless  for  the  purptisca  of  uiat  »mm.  The  cnohlar 
divisiMi  we  have  Iruced  ^|  lilif)  iutti  the  bulb,  and  the  vertibular  dirbita 
into  the  lateral  aiidili>ry  nucleus  (which,  {>^rhup«,  majr  be  rvganlcd  ss  s 
ooiiliniintion  ur  segmental  n^itetitiuu  furward  of  the  cun«at«  ducIms  ei  rf 

Iiarl  of  thai  nucleuH),  and  iiil»  the  cerrlielliim,  the  cfrebcllar  coniinusila 
(cing  probably  lh«  part  uf  the  lu-rve  whii^h  m-ivfti  for  coordinating  {\Uf^ 
tions.  The  conneclious  of  the  auditory  ovrw  with  the  ccrvbral  be(uis|>ken 
hcl'iiig  to  tliv  sanit'  category  as  llione  uf  iitbcr  air<:rrnl  cranial,  and  w»  WKf 
add  vpiiial,  nerve*;  we  have  ug  very  clear  anatomical  gutd*  toward  taj 
particular  part  uf  the  curieK. 

When  wu  turn  lu  the  empirical  result*  furni»hud  by  cxperimeol  Oil 
clinical  glNwrvationo,  we  liod  that  these,  though  even  loai  dcifinitcandka 
accordant  than  in  the  caw  uf  the  senses  of  sight  and  einoll,  point  tn  poitgf 
th«  6nt  or  superior  temporal  (tcmporo  sphenoidal)  convolution  i  Figs.  Sf>l, 
207,  and  209)  lying  in  the  teinjiuml  lobo  lust  rcntntl  to  the  Sylvian  lisiurr. 
as  being  specially  concerned  in  lionring  in  some  such  way  as  the  ooci{>ital 
lobe  is  concerned  in  vision. 

Electrical  Niimulnlion  of  thi»  region  of  tJie  cortex  give:;  rise  to  "  prickiag 
of  tlic  ran,"  and  other  movements  such  ae  are  frequently  coooeeted  wiu 
auditory  sensations :  but  such  phenomenn  are  in  ibis  iusUnce,  perhaps.  In  bt 
depended  upon  even  len  than  in  other  similar  inslonoes.  While  sqm 
ohwrA-era  maintain  that  this  conviilution.  the  ojwration  includlns  other  |Mr- 
tiuns  of  the  temporal  lube  as  well,  may  be  remured  from  a  monkey  wttliott 
prorlijcing  any  certain  signs  of  deafness,  other  ob«ervers  have  Aiund  Ihsl 
reniot'al  of  it  on  one  side  alftoted  the  hearing  uf  the  car  on  the  oppuaite  nde, 


CUTAKBOCS  AND  SOUB   OTnER  SENSATIONS. 


SSI 


ttnfl  rmmvnl  on  boili  hiiIiv  brouglit  the  uniiiikl  into  n  coii'lition  in  which, 
without  being,  [icrha|Kt.  itlxu^luMlj^  cIohC,  it  ru(icte>l  luiruril  sriunil  iu  a  vtty 
im{>crri-n  Riniin^r  iiuWed,  verjr  iliiri-rotit  fmm  if  n'lriiial  ItchaTior.  Tho 
tcttuty  clink'ul  hi*t<irici  bMring  oii  Cht«  mnU«r  iirt'  not  vt-rr  <l<.viiuvc;  tut 
(bough  dofttcH  hw  beeii  oW-rvtil  in  cnnncciioii  wilh  ilixr-o*!:  ulliscliiig  llio 
M|i«riDr  I«in|Mnl  cunvoliiliim,  Xbv  li^ion  Ua^  usually  invniltHi  other  [iiirt*  A* 
««ll,  ami  tho  iliAfiiew  hns  bovn  imiH'lBtf)  vrith  other  «ymptoiiK,  iioUtbly 
opbuin.  All  auditory  "niirii"  hiu.  hovrovcr,  ai  titiirs  h^eii  obicrviil  in  oon- 
Bcccion  with  dinuwe  nf  this  nvioii,  u  nlto  n  |HM-ulinr  jwychicul  fnilure, 
known  ta  "  vrurd-dcAfutsw,"  in  vrnich,  though  «tuni)8  arc  bvard,  thai  ia  Co 
Mf  Mui'Uory  wimtioas  »n  f«lt.  il  amy  bo  ovon  as  UMintl,  thd  porcoptivii  or 
paychkal  npprtmtion  ot'  the  tounils  U  tacking,  and  a  ftpokea  woia  '»  not 
rvn<g»imi. 

Iitutlr.  we  may  add  that  though,  ni  we  said,  tho  anatomical  leftdiog  is 
Dot  debtiitc,  ob»ervet¥  have  fouuil  that  in  nenb'iro  animiil*.  on  tho  ono 
band,  destruction  of  iho  fwrt  of  the  ci>ri«x,  |>rjl>ably  corr«:«poniliiig  to  llie 
ragioji  mmtioncd  above,  lemla  to  atrophy  of  the  median  corpus  gniiculatuiu, 
and  to  mnte  extent  of  the  poBlerior  corpus  quadrigeminum ;  aiid,  on  tho 
other  hand,  destruction  ot'  the  iulcrnnt  ear  lends  to  an  atrtiiihy  of  part  of 
tho  lateral  fillet  of  t lie  opiKieile  criMsed  side,  wbJeb  (BAjr  b«  traced  to  the 
posterior  corpus  qua(lfi;(i;iuiauin,  and  llieiice  to  the  median  oorpiK  genicu- 
lalum  ;  and  seetioa  of  the  lateral  fillet  nu  one  side  leads,  among  oltier  re- 
sults, to  siruphy  of  tbettrin  acustica;  aud  tuherculum  acusiicutn  (Smifjof 
tho  mnwuil  sidu.  Thia  auicgeita  that  the  path  of  auditory  impulses  ia  along 
Uw  cochlear  nerve  to  the  uUeral  fillet  of  the  crossed  side,  and  so  by  the  poa- 
lerior  cor|His  (jiiiulrigeuiiiiiim  and  median  corpus  geniculatuin  to  the  cortex 
of  the  teinponl  lobe  uf  that  croMcd  side,  the  two  later  boiliei  beariutf  toward 
bearing  a  relation  aomewliai  tike  that  borne  towar«l  eight  by  the  anterior 
eorpua  quBdri)^:cininuiu  and  lateral  corpus  geniculainm.  But  tlm  matter 
needs  funlier  iurestigalion. 

Tlierv  remain*  the  special  aenae  of  touch,  but  this  wo  bad  better  consider 
in  oonueciiuii  niih  mentations  in  gonerml. 


Ox  THR  D(n-|CI,OPllBKT  OP  COTAXtOVB  AJIO  OOMB  OTItER  SkMSATIOS'S. 

$  STB.  Tho  eenaaliom  with  which  we  hare  juH  dealt  ariw  through  im- 
pulsee  [M)«ing  along  special  nerves  or  partA  of  special  nerve',  ihe  optic  nerve, 
tbo  olfaetury  nerve,  etc.;  ne  have  now  to  deal  with  aeitsaiious  arising 
through  intiiuises  alou);  the  nerves  of  the  hudy  generally.  Those  are  of 
several  kinds.  In  tlie  tlmt  place  there  an  aeusaiious  which  we  may  speak 
uf  MS  "cutaneous  seoautiotiii,"  the  impulses  giving  rise  to  which  are  stnruil 
iu  the  skin  covering  the  budy,  or  iu  toe  so  called  mucous  membrane  lining 
certain  passages.  Vbtae  sentatioua,  wbicb,  as  ne  shall  see  in  dealing  vita 
the  MUM,  are  dependent  on  the  existence  of  special  terminal  oi|[aiM  in  or 
near  tlw  skin,  are  senaations  of  "touch,"  iu  the  narrow  ueaaing  of  that 
word,  by  which  we  a[>preciuie  contact  with  and  prenure  ou  the  skin,  and 
the  w-nsatiuns  of  "  tcni|>enilure,"  which  again  we  may,  a*  we  shall  aoo, 
divide  into  <<-nBstiiin)i  of  "hrJit"  and  >cnuiti<>ii»  of  "cold."  ThcM  senaatioiM 
may  Iw  cxciteil  in  varyinj:  degree  by  impulwes  pawing  alimi;  any  nervo 
branches  of  uhicli  are  siipiilird  to  the  akin.  Tlien  lliere  are  the  wnsaltoiH 
ninitiltiting  the  "  muKcular  srniu-,"  to  which  we  have  alrcaily  refi-rrol.  and 
tlH-*e  again  may  bo  excitcil  in  nny  nerve  having  ounneotion*  with  ihv  skrt«tal 
uuKclo. 

Aa  nc  shall  see  iu  dealing  nith  the  se^s(ll^  when  a  u«rve  is  liud  bare  and 


652 


TDB    BRAIK. 


it*  dhmt  arc  fltimtilnlcd  dircclly  vith^r  by  pnmure,  Kucb  u  plnchij);.  or  br 
hmt,  or  by  cold,  or  in  other  irny*,  Iho  E«»uiotii  which  are  atused  ilo  nnt 
fnablo  UK  to  npprwisto  wlii-thcr  the  elimulatioa  is  one  ol' contact  or  pmniR, 
or  of  tcnii>erntiire.  "r  of  mime  ollirr  Itiml :  w©  only  Piperience  a  **  fccliag." 
which  nt  all  events  vthrn  it  rcncho.i  certain  intensity  we  speak  of  sa  "pain." 
And  no  have  rctuon  lo  think  that  nt  leti^t  from  lime  (o  time  inipulaes  alung 
various  n«T^'cs  give  Hkc  to  sciifations  which  liave  b«en  apoken  of  aia  iboae  o^ 
"  <^ncrnl  Bcneibiliiy,"  by  which  in  addition  to  otfafir  senaMiona,  mcli  U  than 
of  loucli  and  of  the  niusciilnr  ecnne,  ne  become  aware  of  chan^ei  in  tbe  con- 
dition and  circuni^tnnces  of  our  body.  When  tlie  stimulaUon  of  lli«  akia 
excee<)s  a  certain  limit  of  intensity,  the  sen»e  of  touch  or  teuperature  it  Icat 
in,  that  b  lo  «ay,  ia  not  appreciated  aa  separate  from,  tbe  seuae  of  [tain ;  and 
uiidcT  abnormal  circumstances  acute  aeusatiuns  of  pain  nr«  started  by 
ohangeit  in  pitrtsi,  for  example  tendons,  thi;  condition  of  irhioh  under  nurmal 
cJreiinisiancvs  we  are  not  conscious  of  appreciatioi;  through  any  diatiact 
HcniutlioN,  though  il  may  be  that  these  parts  <Io  uorniallv  givo  rise  to  ftablt 
impulses  coiilrihuting  to  "^neral  acnaibiliiy."  It  may  Ihcrcfore  ba  debaud 
whether  "  pnin  "  i#  a  phatw  of  all  ML-iisations,  or  of  ocncnd  nntibtlity  aioiM, 
or  a  aeDsalioii  itri  ^mrrir.  We  »ball  hnvu  utiuetbmg  further  In  aay  od  Um 
iDBltcr  vrheii  we  tn-at  of  titi-  aenscn ;  nieiiiiwhile  it  will  be  convciiifot  fijr 
prtacnt  purpoew  if  we  coniiitlcr  ibiii  thu  M^imtinna  wo  have  to  deal  with  jort 
now  are  the  aenantion*  nf  toin-h  imd  of  tcm|icrAturc  tho«c  of  tb«  muacular 
Ecn^c,  and  ihoM  of  genera]  wMisibilitv  including  thmw  of  rain. 

S  680.  The  lairly  convincing  cvi({<rucv  that  the  occipital  cortex  haa  «|)«ciil 
relatione  nilh  vi»i»ii,  and  tbo  leas  clvar  evidciMo  that  other  ret;miis  hate 
special  relations  with  #mcll  and  hearing,  suggest  that  opecial  parts  of  ibr 
cortex  have  spedal  relations  with  tbo  M-u»aiioii4  now  uuder  conaidermtiaD. 
Rut  in  tbecoenof  the  senses  of  sight  and  smell  we  had  a  distinct  anatomical 
leading;  and  we  have  seen  how  iincertaia  is  the  eviilence  where auehoa 
anai'inilcal  leading  fails,  as  in  hearing  and  taste.  In  the  cose  of  aenntiaaf 
of  llic  body  at  large,  the  anatomical  leading  siniilarly  fails.  Moreover  anr 
attempt  to  piith  the  auahig)'  of  sight  raises  the  Ibllowing  (jueetion :  If  tlute 
were  Ino  optic  nervts  on  uarh  side  of  the  head,  would  tliere  be  iwo  cortKal 
nrtn.i,  one  lor  each  nerve,  in  each  hemisphere,  or  one  visual  area  only  ?  And 
again,  if  the  optic  ucrve  were  the  iostntmeot  for  some  sense  in  ailditioa  to 
thai  uf  fight,  ivotild  thi^re  be  two  oorlical  areas,  one  for  each  actu>ation,  or 
one  area  only  srrvin)(  on  the  cortioal  BtatJon,  bo  to  af)eak,  of  ibe  wholu  nerve* 
If  wc  push  the  nnulogy  of  sight  it  is  open  for  ii*.  sin<-e  we  cannot  give  a 
definite  answer  to  the  nlMve  (juoilion,  to  suppoee  either  that  there  \*,  ouc  afm 
for  touch,  another  area  for  iem|ieniture.  ana  so  on,  cueh  fur  the  whole  bu<lv, 
or  that  there  is  an  arvn  liir  sen^aiious  of  all  kinda  for  i-Dch  ufli-rcjiL  nerve,  xr, 
that  then?  i»  an  intricate  arrnngemerii  which  su])pli«»  all  the  iinnbiiuUioaB  of 
the  two  uhich  are  re<inirud  lor  tbe  lifi-  of  the  individiuil.  Of  ibo  thits 
hvpothcwe  the  iHllcr  i»  the  nicin-  pmbable  ;  but  ifto,  it  \»  by  it*  very  oatan 
nfninst  in*iieceptjble  of  en i>cri mental  pro()f,  e»|jeuially  when  we  bear  in  mind 
what  wc  have  already  (aid  touching  tliLMliKiiolty  of  jmlging  tlw  smsattoiM 
of  nninints.  If  the  judgment  nf  visual  senMilions  is  diHJcini.hnw  much  mon 
difficult  must  bo  the  jiidgmmt  of  nenMiliotia  of  touch  and  lemperatureT 
Indeed,  sensations  of  poiii  are  the  only  tfciiutions  of  which  we  can  tonn  a 
qnantitalive  judgment  in  animals ;  and  our  method  of  judging  eveo  these, 
namely,  by  studying  the  movenivDta  or  other  effects  indirectly  produoed,  is  ■ 
moat  imi^rfoct  one. 

We  can  learn,  therefore,  almoat  absolutely  nothing  in  this  malter  frtitu 
experimental  stimulation  oT  the  cortex  in  animals.     As  we  have  jirevioorlj 
J&ViJt)  urged,  the  absence  of  tnovemente  when  parlaof  the  consx  oiberlbui 


CtTTAA'BOas   IXD  80MB   OTHER  SB::TSATI0N'S. 


&fi3 


the  motor  ngiom  are  Blimulaler]  is  no  ovid«nce  tlist  tboslimulntion  doa  not  i 
^ive  riM  to  mrcliical  oveiiU  iutu  whicli  scnsntii>ii«  eiit«r;  and  movcmcoU  ] 
follov  Btimulaitoii  of  tlie  motor  area,  not  beesim  that  area  is  wholly  givMi 
np  to  motor  ereiiu,  but  because  fi'Oin  the  bialolaxical  arraDgemoot  th« 
stimulus  gfitt  rmdf  tceem  to  relatively  simple  motor  meohaniani*.  TliJit  ths 
motor  re|[ian  has  close  oonn«otiona  with  sensory  footon  is  not  only  almost 
certain  uo  ibeorelical  Krounil«.  but  h  ibown  in  many  ways,  fur  example  by 
the  experiment,  deMrribed  in  S  Gtii,  of  exalting  the  leuaitireaess  of  a  oiotor 
area  by  generatioji  peripbenil  eeDwry  impulseo. 

Nor  can  the  eflecta  on  Miiaation  of  reinovat  of  parts  of  Ike  ooftox  be 
inierprvt^d  with  olearneu  and  oertainty.  In  thi->  monkey  removal  or 
Heeiruciivii  of  die  gyrus  f(>rni<-utus{Fi{pr.  'iO-S  nui]  205)  on  the  meaial  surfaos 
of  the  braiu.  veniral  to  the  c'ull<i:to -ra^r^innl  suI(-uh  whiuh  forriH  on  the  meaial 
aarfnce  the  ri>iitral  limit  of  t]i«  motor  rf^i»ii  fait  operatiim  of  very  great  dif- 
ficulty), ha-<  brought  die  wfaulu  iif  the  opjHuite  »i<j<:  nf  the  body  toaoonditioil 
which  baa  bceu  <li>3irribty|  nn  aii  anicsthvsia,  that  U  a  low  of  all  oulaueoua 
tactile  Mneadon*,  ainl  an  aunl^fvvin.  that  itt  a  lo«  nf  M-iuatiuiu  of  [lain,  the 
couilitioii  ImIii^  acc!itin|ianivi]  by  littlr  or  no  impiiirmi>iit  uf  vulinilary  move- 
mcnlii  iiikI,  ihnujjh  npjtaruntly  ilimininhinj;  n»  linir  went  on,  lantiiij;  iiulil  the 
(liMth  of  tlii>  animal  some  wft<lc»  nArrwunl.  Ajfain.  removal  of  the  eon- 
tiniiation  nf  tin*  gyrus  foniioHluii  into  the  iiyrux  hi]i|>i)campi  hoa  in  other 
ioManoea  led  to  a  nu>rv  tran<ipnt  annj^lhtvia  also  of  the  whole  or  greater  jiart 
of  one  iUki  of  the  body.  Ami  it  i«  imi-rlcil  ihut  removal  of  no  other  rLVton 
of  thf  cortex  iDt<:rfcri.ii  wilh  irulnn^oiis  and  )«inful  s«ii«atigns  in  «u  striking 
and  laMtiiic  a  manner  as  docs  the  removal  of  parte,  or  of  the  wbulc  of  Uiu 
mMtal  r^oD. 

ThcM  ruulta,  however,  do  not  accord  with  clinical  experience,  which, 
thougli  aouity,  seeniD  as  fur  ns  it  gix*  to  shoiv  that  in  man,  when  mischief 
apparently  limited  to  the  cortex  produces  loss  of  aeiisatioDs.  it  is  Ihu  parietal 
lobe  eorret|H>iHliu>;  to  the  mutor  region  which  \a  afTiwted  ;  but  ihore  appears 
to  be  no  recun)  of  any  caM  of  a  cortical  lesion  aSeedng  aeiisaliaa  without 
aSet'iiu;;  mi>i'eiiiuiil.  We  have  praviiiusly  called  attention  to  the  fact  that 
Uie  temporary  Iiku  or  iiapnirmeut  of  movement  whivh  follows  removal  of  an 
area  iafr«()ueutly,  if  not  alwuvii,  mi-omjanled  by  an  impairmeDt  of  cutaneous 
sensations  In  the  limb  or  part  "  (taralytod  ; "  an<l  side  by  side  with  thU  we 
may  put  tlie  expuriciicu  that  in  the  human  cpilepliform  attacks  of  cortical 
origin,  the  *L-iiiirt:  U  at  times  ushered  in  by  peculiar  •enHations.  calleil  the 
**  aura,"  in  the  part  moventents  of  which  iiiauKuralv  the  iiian-h  of  oonvuliiv« 
novemcnts.  Rut  these  thin;^  do  imiKhow  thai  the  cortical  area  is  tbe"aeafc 
of  sensaduiu,"thev  rstber  illiii>lratc  what  wt  nutd  ooncerninK  tbo  complexity 
of  the  chain  of  wliicb  the  events  lu  the  orlical  area  an-  linlU,  and  tite  cltMe 
lie  between  sensory  factor*  and  the  diaracl^rislic  elcuunls  of  the  motor 
nrioo. 

la  ibodog,  while  romoral  of  almost  any  oonsidcrable  portion  of  Iba  cortex 
nflbotsanmdon,  removal  of  |>arts  in  the  frontal  region  producing  per^iapa 
l<M  «6«ct  than  removal  of  parts  in  other  regions,  the  loss  or  iiapairmeot  of 
•cnaatioa  apfwars  to  be  trannent,  though  having  a  duration  brosldly  pnpor- 
liouu*  to  tM  extent  of  cortex  removod  ;  and  when  a  very  large  portion  of 
tha  cortex  ta  nmoved.  some  imporfeclion  apiMutrs  to  rem  lia  to  the  end.  ^Ve 
have  already  nfcmd  to  the  cim«  of  a  dog  from  which  the  greater  part  of 
both  ccrtbru  bemitphem  hiui  Imwm  removed,  but  irhich  remaiiwd  capable  of 
currying  out  maet  of  the  ordinary  bodily  moremcutB,  ami  that  apparently  in 
a  voluntary  naninri  in  this  ease  the  "blunting  "  of  cutaneous  scnatioiM 
was  perhaps  more  striking  than  the  imperfcciiim  of  movement.    It  will  be 


854 


THE    QRAIN. 


wadh  vrhilc  to  consider  the  condition  of  this  dog  n  liltlo  cicely,  on  Drcnunt 
of  Ihp  li|!ht  vrhii-li  it  thron-e  mi  the  {l^)b1em  which  irv  nre  now  diKruwiiit'. 

Clinit-ul  vxpcrieticv  shows  thnt  i»  mnn  (lie  tnlpgriir  of  the  cH-nrhnl  hviui- 
epherefl,  and  til' the  conneclion  of  ihr  hi7ini#phprcs  nilh  the  rot  of  Ihi;  i-eiitrnl 
nerroua  PTsleni,  is  e»^ntiiil  to  the  full  dcvc'opmi'nl  of  Bensnttana;  Hiid  ittnl 
in  this  i'e»pei?t  eavh  heiniitphere  is  rclolcd  to  ihe  crowed  eid«  of  tbo  bodr.  A 
very  nminiitn  form  of  pHrnlyfis  or  "  itroke  "  is  llim  due  to  n  Icwiou  of  dmiic 
pnrl  of  one  hpint<>pbere  i  the  e\act  poflilion  of  the  lexion  need  not  concera  n 
now  f.  freqiieiilly  cuiiaed  l>v  rupture  of  a  hloodvmsel,  in  which  ibe  pttMlit 
lo^ea  all  [lower  of  v«lciutary  movement  and  all  senMlioM  on  the  cmoaed  fide 
of  hie  body  (.incluilio^'  the  face) ;  lie  is  said  lo  he  sulTeTinK  from  hcaii|defta, 
"oiie^ded  stroke."  Not  oulv  )to  vnluntarv  iiuimlaea  fail  lo  nach  the  mu»- 
c)ea  of  the  oflecleil  side,  but  Bensory  imjiuiaes.  aiii-)i  as  those  wbicb,  starlcd 
for  iotilance  in  the  !<kiu,  would  under  nornml  mnditioiti  leiw)  to  aenaslioas  of 
touch,  of  heat  ur  cold,  or  of  pain,  fail  to  ede«t  oouaciouaneM.  when  tiwr 
originate  on  the  alfected  itide :  the  iiatient  ceaiioi  on  tlinl  aide  feel  a  reugli 
surrace,  or  a  hot  body,  ur  the  prick  of  a  niu.  For  the  sake  of  c)e«iroeM  it* 
•uppoeie  Ibe  loes  of  ninvenient  and  »en««ti<in  to  he  eoinplele,  but  it  niif  bl  nf 
CQune  be  pnriiaL  Such  u  case  Bhuvs  we  retieat  llmt  l\n<  integrity  of  thr 
oerobnil  benii*phere,  and  of  the  eonneciiaoH  ot  thnt  )i<:ml->pbcre,  we  mny  mj 
of  (he  ct>rtex  ot  that  henil^phure,  with  the  other  parU  of  the  nervous  qntm. 
i»  cmcnlisl  lo  the  develnnment  nf  the  «enM(tion!t :  l>ut  it  dnea  not  prove  tbat 
the  oorlcx  of  ihu  heminphere  i*  the  "  r<}al  "  nf  thu  wMiKjiltoru,  it  d(M«  not  ptvn 
that  ibi;  a(IVr«'nt,  and  Miiimry  impiilm^  olnrted  in  the  skin,  uodorgo  M 
Dintrrinl  chiinge  nnlil  thfv  mich  the  Diricx  mid  nn'  ihi'n  ^nddciilv  convertrJ 
into  »i'n>alii>iiii :  il  njily  priiv^'*  ihal  in  the  rnniplcx  chain  of  <.'vents  bv  wbitk 
ecntory  inipiil^ick  give  riw  In  I'lill  tmnsciDiin  K-nwilioiw,  thcevciila-in  the  conn 
niroish  an  in<Iie|>enHible  link.  And  the  phi'nonicnn  of  the  dog  in  qUMwa 
on  the  one  hand  illiistrale  how  complex  ihe  chain  is,  and  on  the  other  hand 
mi^gest  that  the  contpletcDeas  of  the  lorn  of  senHitian  in  tbe  heniiple^e  bmu 
h  not  a  pure  '"deficiency"  phenomenon,  but  is  due  to  the  Iwion  atlecliDglha 
diaiu  of  eventa  in  some  way  or  other  besides  merely  removing  tbe  link 
Airnialied  l>y  means  of  the  cortex.  For,  as  we  previotiiily  urjce^l,  the  dog  in 
i)iit«tion,  however  curtailed  ila  psychical  life  may  have  been,  wcmnl  to  a 
nenal  observer  to  feel  and  move  much  as  usunl.  Neglecting  vimukI  and 
auditory  sensations  with  which  we  are  nol  now  d(!alii)g,  it  nertlol  cnrrful 
ob»ervaiiou  lo  ascerluin  thai  m>me  of  (he  aniuiurx  movi-meuts  fpll  iihort.  llir 
failure  lieing  apiuirently  due  to  the  lack  of  udeiuatelv  energetic  ciH>r<linnliiij; 
tenMiry  impiil>rH;  n  stnniger  stimulus  than  iittunl  find  to  be  nppli*^]  to  tlm 
•kin  in  unlcr  tucjdl  furih  the  usual  moveinenis  and  utiter  lokena  tliai  tlw 
•linMihiii  niu  "frit."  A*  we  have  before  urged,  it  is  inipoMiiblc  tosnupoM 
that  tbe  mere  (tump  of  cerebrum  k-fl  in  thu  ciuc  i-otiM  have  tnkcn  or  nil  iIm 
funi'tinoK  uf  the  loft  heniLiphcri-M ;  an<I  making  ax  we  have  prvviouely  don* 
full  allon'ance  for  thediflVrentiatinn  butwcrn  niiin  and  t\<r<j[,  wc  muri  ooncludi- 
Ihat  in  tbe  more  geneni  seiimtinnit  with  which  we  arc  now  dt-olini^.  ne  wilh 
the  ninri'  ^pircial  vnrmil  scUMlions,  tbe  full  di^vrlopmcnt  of  a  complete  mdm- 
tion  is  a  complex  act  of  more  singes  than  one  between  thi-  adereiit  impulfc 
along  the  nffi-renl  nerve  and  the  aflirction  of  cnnacioiMncm  which  we  sub- 
jectively rKognin!  a»  "the  scnealion,"  llio  cortical  Bvcnt*  are  only  mnw 
among  several.  It  fullnws  that  any  nnal^igy  bctwcon  lh«  cortical  evenu 
which  play  thi-ir  part  in  a  sensation  and  the  corlical  events  which  irnme- 
diatcly  precede  ihe  imuo  of  impniscs  frooi  tbo  motor  region  along  tbe  flbra 
of  the  pyramidal  load  U  misleaiiini^ ;  the  hi);hly  diRereiitinted  molor  hicallm- 
tinn  does  not  juslily  ns  in  concluding  thai  ihere  exists  a  aimilnr  lojiograplilcal 
'  iisiribuiiou  of  Mneattons. 


,  .  mav  now  Hlbick  tin:  juvililrin  in  *  iliflcrvot  nn)'.  nml  iimli'Kii 

Wgiiining  with  Iho  onrlcx  ln-gin  witli  ntfcrcnl  imptilww  stnrtcH  nluiiK  nlfcrrol 
iwTvcs  from  (heir  pcrii>h<rnl  piiiiinjpt,  iitiil  allrmpt  to  Inn^  ihctn  twntnilwird. 
Anil  lint  wo  aiKv  («ll  to  minil  nhnt  nnnlotnknt  giiiiliiDcv  wc  |i[>{«Fn.  (S  570.) 

W«  hRVt  HCD  tbkt  tti«  tilirrs  of  nnMcriur  ^»<>li^  the  chBnnMd  of  nSorcnl 
iropalM*.  cod  in  the  Hpinni  cord  in  «t  lea»l  two  mun  »»]*».  Ono  tiet  nrr  r^ii- 
liiiucil  "O.  not  lirokcn  by  nnv  rvUys,  lu  (ho  metlinn  pn^lvrinr  triict,  and  Uy 
this  Irnct  ropn?80Dtativf»  ot  nil  the  s[>iiinl  imtvc«  arc  coiinccl«l  with  lh« 
gnu-ik  nuclviifl  in  nhicli,  ^fill,  tli«  nitxlinn  {losCerior  coiiinio  ends.  The 
olhor  fibres  of  a  po&tcrior  rum  ap[>«sr  to  ciiil  in  the  gray  matter  not  fnx  from 
tbnr  entrance ;  but  from  the  gray  instter  there  Blarls  the  cerebcllnr  tract, 
which,  though  not  conctusively  iiroved  to  be,  mar  be  aMumed  lo  be  an  sllercnt 
tfkct.  We  may  therefure  pnibubly  suppoee  that  afikrant  irapulaca  aloDi; 
certain  of  the  fibres  of  the  pMlerior  root  make  their  way  upward  aloOf;  the 
cerebellar  trad,  and  there  are  some  reasoiM  for  re^rdiiig  the  TeeicuUr 
cylinder  nod  tlw  colls  which  rcpre*eTil  thia  where  it  in  nut  conspicuous  in  the 
ref^ons  of  the  cord,  as  a  relay  betuecn  the  Iwd  ^yittems  of  Hbres.  There  are 
alM  the  more  scattered  tibres  of  the  ascending  a ntenv lateral  tract  (ji  &t>H), 
which  probttUy  ia  also  an  allerent  tract,  and  therefore  probably  also  cnn- 
oecled  with  the  poscerior  roots  ;  but  ns  uo  have  seen  mir  koowled^ie  iif  thia 
tract  in  imperfect,  thou^'h,  if  an  some  ui>;e  it  coda  in  the  resliforro  body,  we 
may  [tcrhupe  oouoider  it  as  similar  at  least  to  the  cerebelJar  tract,  and  treat 
the  two  as  luiev 

Thus  there  iieem  to  be  at  least  two  main  reci^gniied  [mIIib,  in  the  form  of 
tracts  of  6bre^,  for  at&rent  iiDimlnea  aluu^;  the  ei>nl ;  one  along  tJie  median 
MMArior  column,  the  other  aUnig  the  lateral  column  in  the  CLTcbellar  truct. 
The  latter  paasea  straight  up  to  the  cerebellum  by  the  nslifonn  body,  lmv> 
elling  along  tl;«  luimc  ntdu  of  the  cord,  and  any  cro*>iiig  ><f  impulse*  (Musiug 
along  lhi»  tract  munt  toki.'.  place  brfore  they  mitrr  the  tract ;  wc  have,  how- 
•rer.  no  anatimiicnl  giiidnoco  lor  viich  u  crowng.  Tbo  other  pnth.  along  the 
BMdian  poMtcriiir  [racl,  comes  to  end  in  the  grncilc  iiucIcur;  it  has,  imleed, 
been  nrgiil  tlut  the  grncilc  nuclei)*  ic  thus  ciinncniect  chirHy  with  the  lower 
limbs  and  lower  pan  of  the  body,  and  that  the  nniilngous  posterior  root 
Gbres  from  the  upper  limb*  and  iic>-k  past  similarly  inUi  the  cuncalc  nucleus, 
or  at  least  into  the  median  diviaion  of  that  nurlvus,  but  this  cannot  be  con- 
ddsred  n*  proved.  Moreover  both  the  posterior  columna,  median  and  ex- 
teroal,  bring  to  thme  nude!  DbrcK  which  h:tvc  started  from  mme  relay  in  the 
gray  matter  lower  down,  nnd  which  are  not  Kbrca  coming  atnii;;ht  wiihuut 
maj  r»lay  from  the  posterior  roots;  these,  however,  wc  cannot  diatiaguish 
mm  each  other  in  their  course  beyond  the  nuclei.  From  the  f^radla  and 
cuoeate  nuclei  the  path  onward  is  a  double  one,  one  broad,  one  narrow.  The 
broad  patli,  the  one  having  must  fibres  and  presumubly  ctirrvin);  m<«(  im- 
pillsii,  leads  to  the  cerebellum  by  the  resliform  body ;  and  lierv  the  path. 
praviously  continued  exclusively  along  the  same  aide  of  the  oord,  heDimcs 
partly  craned  tboitgll  ninaining  ;iarily  uncroaseil,  the  aeiiaurr  decasaMloo  in 
the  bulb  beioj;  the  oroased  and  the  other  fibres  paisiu;;^  i^rom  the  nuebi 
attmigbt  to  the  resliform  body  bcjng  the  uncruaseil  one  ($  613) ;  the  uncrossed 
one  we  may,  perhafw,  look  upon  as  really  an  upper  part  of  the  cerebellar 
IracL  The  uariow  path  U  die  fillet  (§  63-5),  by  which  some  of  the  libres 
from  the  nuclei  am-  co[itinue<l  uo  toward  the  cerebrum.  This  jnith  is  a 
crossed  one.  the  (-ntteing  taking  place  in  the  sensory  decuMalion,  and  it  car- 
liea  relatively  fuw  impulw4,  the  chief  increaM  in  the  titjn  <>f  the  fillet  as  it 
paans  onwiinl  lieing  iliie  to  tibmt  coming  from  siniotun^  other  than  the 
graf  tll^  anil  cum-ati;  nuclei. 

Ili'iicc  of  the  MiuMry  iinpultcs  travelling  along  continuoiu  tracts  io  ibe 


I 


THE  BSAIS. 


epinnl  conl,  these  tracts  nppftrenilv'  kci^iiig  alwAjr*  to  tho  borib  ^d«,  tlie 
creat  mniDrity  nnw  to  the  L't^robclliicn;  nnil  i>r  ihcw  again  the  fmUer  nu» 
b^r,  atl  thoee  alnng  the  corchclliu'  tract,  and  some  of  ihoeo  paMiHg  llimuxk 
the  frracile  nrtd  cuneaie  nuclei  rcmnin  uncrowcd  to  the  end.  Th«  niily  p«lb 
by  irbich  nil  these  impnlsee  lliiis  paasinR  to  the  cerebellum  c«n  gitin  nrcm 
to  the  cortex  of  the  cerehrum,  is  by  some  or  other  of  the  lies  betwcrii  lb( 
cei%belluD)  and  the  cerebral  cortex.  The  relatively  feir  impuleee  which  (■■ 
aloD);  the  fillet  are  for  the  most  pnrt>  landed  id  the  rniddle  paru  of  the  hrmip, 
for  only  a  Hiiiall  portion  of  the  fillet  paareH  l»  the  cortex  ((  &3o),  wmI  it  it 
not  clear  that  this  part  pf  the  fillet  coiues  from  ibe  gracile  and  cuiittlt 
nuclei,  ^a  that  ntoet  of  these  impulses  can  cain  sccos  to  tlie  cortex  only  bj 
the  relays  of  these  mid<)le  parts  of  the  brain. 

Vvry  striking:,  indeed,  are  these  conslanl  relays  oloii^  the  path  of  anuoty 
impulses ;  in  this  reufiec-t  the  sensory  impiilaea  offer  a  atroag  oonlrv.-'t  \n  tbt 
TDutor  iiupulsea.  Itut  a  still  tnore  complex  system  of  relays  ha»  t'>  l>e  tni»- 
ttoned  ;  fi>r  yet  a  third  path  ia  open  for  sensory,  aflbreot  imgmbf*  aloD)(  tbt 
o»rd.  We  miiM  admit  the  pMsibility  of  alli-Tent  Impalsee  trnmllitie  ainar 
the  ui'twufk  'if  the  Knir  matter,  their  path  lieiiig  either  ahaoluioly  i-oDan«j 
to  the  gray  matter,  or  leaviDg  ibo  gray  niattur  at  iiiten'ala,  nuil  }i>!iiin;  it 
again  fav  meiitin  of  thoae,  toncer  or  thorter,  commiMural  or  irifruunoil 
fibres  w^ich  unite  the  longitudiiinl  ti^mcntii  of  gray  matter,  and  fors  na 
ioooosMeruhlc  |>urtion  of  the  vrhrile  while  nuitler  of  ihv  corvl.  Vft  ha*f 
seen  (§  AS7)  that  under  nhnoroial  circiiai9inni:ni  impnixv  pais  frwIyfaniJI 
directionH  aloD)|r  the  ^ray  matter,  nm)  we  may  coucludv  ihut  under  DurnuJ 
eirciini^iniicu  they  can  piuw  ahmg  it  under  ri-Ktricli«iiit  and  along  linca  d» 
lortninv<)  by  phv.iiologii-'nl  ccinditiiniii.  Th<-  Hbrm  in  the  white  matler  wUlt 
do  not  show  either  divci^iidiu^  or  utccDding  degcaontlion  am  pr»bub1y.  a*  n 
have  laid  ($  M'2).  intern itiiciul  fibro*.  oooneeting  ■^meols  of  ;;ray  noilM 
in  a  longitudinal  dinwtton:  and,  though  we  have  no  exact  knowledije  IMt^ 
ing  this  matter,  wo  may  suppose  that  some  of  these  ooovvy  impubea  Hptwdi 
and  others  downward. 

If,  as  some  maintniD.  the  fibres  of  the  ascending  ant^ro-lateml  lrac<  «nd 
not  iu  the  cerebellum,  but  in  the  gray  matter  of  the  bulb,  or  hiifher  up,  m 
have  a  lourlh  path  for  sensory  impulses,  which,  afler  the  (>rimury  relay  io 
the  acKniental  gray  nintter,  pass  slniighl  up  to  the  bulb. 

%  6S!.  ilow  do  experimental  n»ulis  and  cliaioal  bistoriei  acoord  irilbtueh 
an  anatomieal  programme? 

We  may  6nl  call  attention  to  an  experiment,  wliicb,  though  sonMwbu 
old,  carried  out  on  rabbits,  and  con&ned  to  one  region  only  of  th«  oord,  ibe 
lower  thoracic,  has  nevertheless  a  certaiu  value  on  aeeounl  of  iu  ■flhrdiiqt 
mon  or  ledt  dttilnctlj'  i(us.utilative  and  meuavirnble  reMltn.  Wo  ban  seal 
(S  I7R)  that  alTereiit  im|iul««  started  in  aflcrenl  fil>n,«,  in  iltoac,  for  instaiiet, 
of  thi;  ikiiatie  nerve,  so  afleot  the  va«>muf>r  (.-entrv  in  the  bulb  as  b>  caxuaa 
rise  of  blodd-jiruxure,  at  least  In  an  animal  umler  urari.  Tboac  aflVnot 
impulses  mugit  \inia  hr  some  nntli  or  other  from  iitv  root*  which  «npi)lT  tfai 
sciatic  nerves  wil^  Htii-rent  fihreH  along  the  thoracic  and  orrvical  conl  ta  ibr 
bnlb.  If  the  path  lie  Muclted.  tliv  Htimuhition  of  tht^  »cit>tic  nerve  will  Glil 
to  prxiduce  the  usual  riw!  of  blood -pnvMU re.  Now  in  a  rabbit  the  aiixmul  •<! 
rise  of  blood  prewurc  folhining  u|Km  thu  (timuhition  of  ono  sciatic  oerw 
with  a  certain  strength  of  ciirnmt  having  beou  asooflaiood,  it  is  found  that 
a  much  lose  rise  of  blood-pn^iirc  or  none  at  all  folloira  the  same  stimulalioa 
after  division  of  cerlain  i>nrli<  of  the  cord  in  the  mid  or  upper  ihoradc 
region ;  that  is  to  «ay,  the  scclinn  of  the  cnnl  has  partially  or  completely 
blocked  the  path  of  the  aAeront  inipulwn.  Further,  the  block  is  oonapirixiu* 
when  the  lateral  column  is  divided,  and  is  not  increased  by  other  jiarts  of 


llio  mni  beiiiK  dividiil  nl  llit?  same  tini«:  when  I>i>tli  Inlcnil  NKiiniia  are 
divkM,  tli«  block  id  almiuit  complete.  Ami  furiher,  AU]>pi»iiig  udo  ticialio, 
my  llie  rinht,  i»  the  oiw  vrlik-b  h  Hltroulnli;!),  m  block  oocun  both  nbt-u  the 
lateral  cobimu  nf  llic  Mimi;,  nf^l,  »ici«  nn<l  irhcii  that  of  tho  cnjMvil,  left, 
ri*le  b  <livi<le<),  but  \»  tjrvntrr  wbtni  th«  itivioiun  in  on  the  croHwd  than  when 
it  b  i>u  tli«  Mine  Hilr.  Wv  innr  ill^<^^  tbtit  tbc  impiilMs,  which  rencb  tbo 
luRiliar  inni  bv  tlic  roota  of  tno  Huatic  iivrrc,  travol  up  the  oonl,  ur  f;iv« 
riov  wiihiu  ibi-  binibnr  cnrA  U>  cevnU  which  wc  maj  cnmtmro  to  rKTViJU* 
impulm-ii,  ami  which  travel  up  the  corH  lo  »uph  a  maniior  thnt  in  Un-  hiwer 
Ibiiraric  n-cirni  lhi\r  p*>«  almnct  excluiirolj  «loti2  the  6hrr?  of  [Ik*  InU'ral 
ctilunin,  Hoino  hnviiig  kept  t'>  the  mow  aide  of  tne  conl.  hul  nii>r«-  haviug 
|.  ornMiit  over  to  tbo  oppoailc  Bilk'  before  rpat'hing  the  thi>riicic  region. 

Tbi*  rr»iill  ww>  i>ht«inc<i  in  rabbilf,  anii  tbo  eKperimciit  whs  mrrietl  out 
in  ihv  liiirrr  thoracic  region  only  ;  the  nmcbiMons  to  be  drawn  fmm  it  hold 
|IO(hI  fur  that  animal  only,  and  lor  that  i>nrt  onlj  of  its  cord.  Moreover, 
the  experiiiH-Dt  only  t<«t8  the  path  of  euch  im]>ul«c«  as  reach  and  atlrvt  the 
TMOinol'>r  centre  in  the  Ixilb.  It  ia.  however,  DXceedingl}*  prolMible  that  the 
inpulaea  which,  Reoeraled  in  seuBory  nerves.  alTi-'ct  the  vasomotor  centre  aro 
impulare  which,  in  the  con«ciouB  animal,  f-ive  me  to  eensationa  of  |>ain  ;  in 
an  intacl  anitoal  chan;^  in  the  vasomotor  centre  occasioned  by  the  sliainln- 
iMHi  of  eeniiory  nervee  are  accompanied  by  eigns  of  nmre  or  leas  [laia.  And 
indeed  lliia  is  oonlirmcd  by  the  fact  that  eimilar  reeulls  were  obtained  when, 
Ike  eiperiment  beint;  conducted  iu  a  eimilar  way,  sigua  at  irain  instead  of 
rariatioiia  in  blood-preaiure  were  taken  as  the  t«kenii  of  ilie  blockioj;  of 
inipul-M.  Hence,  aMuniin;;  this,  wo  niny  regard  the  experiment  as  indi- 
cati(i){  that  the  impulses  nhich  form  the  basis  of  painful  sensations  paM  by 
the  lateral  columns  iu  the  lower  thomeic  region  of  the  L-ord  of  the  rabbit, 
and  therefore,  though  thi»  in  a  funhi^r  atunniption,  by  the  nine  eolumna 
aloiiif  the  tt'holc  length  of  the  cord.  Wi>  further  may  infer  that  whilv  aome 
of  the  impulaea  keep  to  the  8anu>  Mk  of  the  conl,  olhcrf,  and  indeed  the 
greater  uumbcr,  croat  to  the  ojipiieiie  Mo. 

TheM  eoDcluviona  entail  nssumpiiona,  hut  the  main  intcrprctnliou  of  the 
whole  eiperin>cul  ontnil*  a  still  greator  aaninptioD.  Th«  tcitiog  of  the 
influcnn'  of  llie  tKiatie  atimulation  waa  oanied  out  soon  nfter  the  aoction  of 
the  conl,  and  vet  vin  have  asumod  that  the  block  of  the  imjiulfc*  wti*  due 
to  a  pure  drjieiency  phenomenon,  the  aliM-noe  of  a  UHial  path.  But  wc 
have  no  right  to  do  thiit.  It  m  ^lomiblo  that  the  section  produced,  in  aome 
say  or  other,  a  dvpmxing  or  inhihitorv  effect  loner  down  in  the  cord, 
otfectinf' etructnres  other  than  the  laternf  columns;  all  our  experic^icc,  in- 
deed, of  the  eflecia  of  o|NTntions  on  the  cord  would  lead  ua  to  expect  thia. 
It  is  further  t>os»ihle  that  ii  section  of  the  lateral  colitma  might  prodnee  thia 
depraaiing  eliect,  while  oectiona  of  other  parla  did  Dot,  or  might  produce 
mon  e6ect  than  they  could.  It '»  possible,  for  inataiice.  that  the  section  of 
tlw  thoracic  lateral  column  inhibited,  for  the  period  during  which  the  ex- 

Gnmctit  wa«  carried  out,  the  gray  matter  of  the  lumbar  cord,  and  that  the 
ock  nallv  took  place  in  this  gray  natter.     Until  the  uneertaintiee  thus 
sttMtdinfE  the  interpretation  are  removed  the  ex|>erimeDt  ia  not  valid  as  a 

Eri»f  that  the  lateral  columns  are  the  paths  of  alleretil  impulsee;  it  would, 
utrever.  Htill  aervo  lo  indicflte  that  the  air<.-reiU  ini(>ulse«  reaching  the  onrd 
aloii)!  the  sciatic  nerve  croawd  over  to  a  large  extent  before  they  iratne  under 
the  iiitltience  of  the  inhibition,  aince  we  have  uo  evidence  to  »how  that  .-uch 
ail  iiihil^iury  aelioii  of  the  K«tioii  would  be  exerted  chiefly  on  tlie  crooaed 
tide. 

Again,  we  liave  aeen  that  the  afferent  impulse*  nffiH^ting  the  vaaoinolor 
oeutre  gain  ocota*  to  that  conn  without  the  liclp  uf  tlie  |)aru  of  the  brain 


i 


TUK   BBAIV. 


nlwvc  (he  bulb:  th«  ^xblenoe  of  iho  vasomotor  entire  wns  made  oat  (J)  176), 
by  combiDlog  sttmiiliiiion  nf  n  sciatic  awvt  nitti  a  twries  of  operaliow  cnn* 
mating  in  ninkin^  Micc««»)ve  trnnsvene  sections  of  the  bulb  from  abuve 
doiTiiwnrd ;  an<l  it  whb  not  until  the  Beclions  ivat^'lie^l  liie  rasomolor  pvaire 
that  the  blood-preseiire  eflW-ts  of  tbo  K'iatic  etiriiulsii'>a  were  modtfted. 
Hrat-p,  if  ibe  ex]ierim«Dt  be  taken  aa  sboiriDg  llui  not  only  alTeiviit  ia>- 
nulsps  alffrcliDK  ihe  vaeomotor  centre,  but  otber  aflbrant  impolMs  alau  imrd 
oy  the  tHicral  cohiinDs.  it  would  also  seem  to  show  that  ihew  otber  impuba 
raw  ID  like  manner  to  the  bulb,  ami  fpiin  aeceM  to  lli«  oonex  lliruu|ib  ibt 
bulh.  TbiiH  iiiL-reases  a  <)i0icultj  wbieh  preaenia  ilwlf  vn^a  when  ilie  afleml 
ini|iiilses  alfectiujc  the  vasomotor  centre  are  alone  oousiiltre^l.  If  tine  es|icfv- 
meat  means  anything,  it  means  that  tbe  impulsa  having  in  aaiaewajv 
otla-r  reached  the  lateral  eoluinn,  travel  up  that  column  by  aome  coniinuiNi 
path,  anil  imlee^l  b  ifvnenilly  lalton  ax  bavin:;  thtii  mmitiiig.  Il<i(  if  a«  pul 
uoiiltT  the  very  ihiiibtt'iil  vievr  that  the  aaceniliii^  nnliTri-hileral  tract  end*  ia 
the  bulh.  there  In  no  <'iiiiliniii>ii>  iilTiTcnt  inict  in  ihr  latent)  column  viuling 
in  the  [>iilh ;  the  only  ilelinitc  oontintutiu  ntFurMit  tract  in  iho  lateral  cilania 
of  whirh  nc  have  any  clear  knnwhilgc,  nanitilv.  ihi^  lyreUrllar  tract.  «*Ji 
not  it)  Ihi'  hiilh  hill  in  thu  cm-bclliim.  Anil  if  itc  attempt  to  gt>ttiat«l 
Ihe  ilitficuUy  hy  wippnninir  that  thiwc  impnlnw  at  least  which  anoit  iW 
vasomotor  centre,  nfi«r  truvrlling  fur  »omt  iJii^tance  in  tbe  cvrelwllar  IrtiJ, 
leave  tbnl  tract  for  xomr  path  Imiliii^  t»  the  bulb  'ami  th«  eervbellar  tnd 
AotB  probnbly  give  "H'  »*  ivcll  as  receive  Sbm  along  ils  enun«^),  we  |irKti- 
cally  admit  ihat  the  experiment  docs  not  prove  tbe  existcnoe  of  a  cuntiDaoM 
piith. 

A  further  difficultv  i«  raised  by  the  fact  that,  ncenrding  to  tbe  interiinta- 
tinn  which  we  are  disctiinng,  the  section  of  the  lateral  column  breaks  ibi 
pntlia  of  what  we  mav  consider  two  kinds  of  impulses;  those,  tbe  larfir 
mimln-r,  which  have  ulready  cioased  iVom  one  side  <if  the  cxtnl  to  the  nthsr, 
and  tbow;  which  have  remained  on  tbe  same  side.  For,  as  are  bare  alrvadr 
wiid,  we  have  evidence,  in  man  at  leiiat  and  aooie  other  nnimals,  that  alKreiU 
impiiUc*  crrm  coin|ileiely  over  somewhere  or  other  on  ibcir  path  b«lcin 
they  arc  develops)  into  full  senMilionH :  anil  ae  have  alio  cvidenoe,  iboo^ 
bw  strong,  that  they  enui*  not  lon(f  after  their  entrance  into  the  ronl.  But, 
if  wcmppiwo  thin  to  bi-  tbe  cuse  in  tbe  ntblnt  aliio,  it  follow*  that  in  ibi 
experiment  in  tiuivlicm  the  inipiiUat  whioli  were  blocked  on  their  pOMUip 
nloni;  the  lateral  column  of  tbe  aame  sbk,  whatever  the  way  by  which  tblf 
reiichcd  that  Intcnil  column,  were  pursuing  a  tiath  which  would  evonlutJljr 
have  Icil  tlivm  lo  tbe  other  aide  of  the  oonl.  Hence  the  tei'tion  of  tM 
lateral  coluinn.  in  hrt-akinu  their  path.  Iimke  not  a  rotiiinnoun  path  kve|iini 
to  the  IntomI  column  up  the  length  nf  the  conl.  but  a  niilb  which  *oon  Irft 
the  lateral  column  lo  pnwi  cWwIicrc.  Tbe  experiment,  tnercfbre.  as  flir  a*  iW 
impulses  passing  up  the  xanie  xide  an-  conci-nied,  docs  not  prove  that  llw]r 
purfuo  a  continuous  |>ath  along  the  lat^-ral  column ;  and  if  so  what  bewnMi 
of  ils  validity  of  the  cxiieriment  as  regards  the  impulses'  eroming  over  trm 
tbe  other  aii^e,  for  tbe  experiment  in  itwif  nmki'S  no  dirtinction  beima 
tbe  two? 

We  may  add,  however,  Ihat  tluingh  tbe  pi>int  has  not  been  spet^'inlly  Iv 
vc«tiK»led,  it  is  possible  thnt  in  tlia  rabbit,  in  wliuse  hind-limbs  bllatent 
movements  are  so  pnytominant,  lher«  n  asanciated  with  the  mnvemeala  ■ 
bilnleral  arrangement  for  senHaiioiu,  and  that  thnae  impulses  whicb  rsnisia 
aloMif  the  Mime  side  of  the  coid  as  the  nerve  in  which  tbey  origlnata,  an 
carrieil  up  to  the  brnin  willioiii  any  crosfiug  at  all. 

$SB3.  The  results  of  this  vasomotor  experiment  then,  though  tbev  are 
fnnpiently  cjuoted,  do  not  nhen  closely  considered  aiTord  adetjuatc  proo^tlial 


•flVn^nt  iinpu1«r«  pumi«  k  cvnitimimi*  |inlh  ilnng  the  liitcrii)  columns  of  (he 
otti,  ami  mun.-»vfr  lliti  fiu'tK  brought  In  light  hv  ihn  cxpcrimeDt  «li'iw  hut 
lilllv  iu-c<inl  uitli  tlw  anaromicfll  imigrnmitK'.     \Vi-  hi>v«  dwdl  i>n  it  to  long 

»brmUM.*  it  i*  more  or  ]««■  illiialrnlivc  of  tW  mnnv  iliffii^iilticx  alt^Diliiiit  the 
iiilrr|in-(aiioii  i>(  i.>x|H-rimrnl»  of  ihis  \tintl ;  ami  il  i*  in  thru  n'*|M'ot  nil  tlie 
mort' valumltlfl  tfM-nuM!  the  notiifil  (■xprrimontni  iyvuIIk  mro  sbnrp  nml  fvlciir. 
Wr  iiiHv  i>M>  oier  mi>rr  rnpiiliv'  t)ic  iinmi'rniis  e<K|KrrinimL*  on  thi^  lower 
naminiiM,  >ti('h  iu>  rnUhit*  itml  dogs,  in  nhirh  olWr  inilicAtiotiB  nF  icDiutton 
have  hwi)  miuli;  ut  of.rhii-My  (hiwc  which  nrplhc*ipn»or|minriiI  nMnnliooji ; 
(h<»"'  have  h«i'w  rarrini  out  in  vnHnuB  repnnn  of  (he  cnnl,  hut  chirflr  in  tht 
ihnracic  n-^i<in.  iin<l  in  ihem  a  like  unccrTainlr  of  inl^rprelntton  t*  further 
ini-nnw-d  hv  div  want  nf  cxiicln«*s  nnd  aKivoinciil  in  (li«  r«»nllfi. 

If  ire  cnnlirnt  nuKrlvps  nilh  innkinj^  no  ilixlinrtiori  lielneen  the  iliirrr<>nt 
kinds  of  alTcmu  impiilsrs,  nnd  in  (h«  cute  of  ihew  animals  it  wnuttl  h.inlly 
be  profiliihk  to  nttcnipt  to  moki?  n  ilixlinction.  we  niny  say  thflt  thi*  •■-vcrn) 
■  •itxrinicnt)'  m>  fur  nf^rvc  ihnt  they  point  to  the  laleml  columns  as  hoing  thi.^ 
uhiff  paths  of  alTtrenl,  fcnmry  in)|m])>ra.  or  to  spenk  mure  eiacllr.  to  tlio 
■INMMge  of  these  impulses  bcine  <»|>ei-ia]ly  blockinl  hy  aeclion  of  the  Inlpml 
■eoldtnitB.    tfome  obefrvera  find  that  in  the  dog  and  other  loner  nmmmale  m 
nction  of  the  lateral  colimin  on  one  aide,  or  at  least  a  liemisection  of  the 
cord,  produces  "  loss  of  sensation  "  on  the  oppoaite  ride,  (■reater  than  on 
tbe   ain«  side,  or  confined    to  the  oppojrite   aide,  and   even  accompanied 
hv  an  exaltation  of  sensation,  a  hy|>erMthcsla,  on  the  aiirae  aide.    Other 
oWrvers   a^in,  and    these  certainly  competent   ohserver*.   find    that,    in 
the  ilo}t,  section  of  one  aide  affects  sensation  on  both  aidea,  and.  indeed, 
rhi^'tly  on  the  same  aide.  We  may  perhafs  onoe  more  repeat  th«  vaining  how 
difficult  a  the  ciuantitative  and  (|ualilativ-e  dt.-t<Tnji nation  ofM-nnitionH  in  such 
an  animal  an  the  lUig :  and  may  r«'ni(irk  thnt  in  nil  thc9«  cases  of  unilati-ml 
LsFclion  the  incrciiM-d  blond  Kupply  dur  to  failure-  of  the  normal  vnoooon- 
'■iriclar  tune  niuyl  intliicn<v  thn  (ifriphoml  development  of  aensury  impnl***. 
In  ihete  experimint.-',  «»  in  ihtiw  on  voluntnri-  movements,  it  is  laoH  im- 
portant to  diatiiiguinh  hi'lw«N-n  tmniiHliatt^  or  tenipomnr  and  more  lasting 
tfTrclM:  and  obaerTcra  hnvo  found  (hat  the  loss  of  sensation  folloiring  a 
liemiM-ititin  of  th*  rord.  like  the  lo<«  of  rnluntary  movement,  is  temporary 
only,  and  eventually  disappeiirs,  though   the  recovery  is  slower  and  leai 
eoninlcte  than  is  the  ckm  with  movements.     As  with  voliiniary  movement 
(f  G04)  ao  with  Si-nsntion,  recovery.  tJiough  leM  eomplete  than  that  of  move* 
meni.  b  pQiajhIe  when  n  hemiscetion  on  one  side  has  been  at  a  later  date 
fultowed  by  a  bemiscclion  on  the  other  side.     We  tnay,  therefore,  repeat 
in    rvfercDoc   to  sont>ations  the    remitrks   which    we    then    made   in    refer- 
ence to  inovenient;  there  is,  however,  an  inijiortnnt  diflerence  between  the 
two  cases;  in  respect  to  movement  we  have  evidenoc  that  under  normal 
c<>ndition«  the  pyramidal  tracts  pinys  an  important  part  and  thai  any  other 
|NUh  for  volitional  impulses  is  more  or  le*B  an  alternative  one.  whereas  in 
napect  U>  seoaation  we  have  no  anatomical  or  other  distinct  piuof  of  any 
Boen  Dormk)  jMth. 

Th*  expennetita  on  monkeys  are  in  tike  manner  oeilher  aecordnot  nor 
deviaive;  and  even  in  thrae  animals  with  their  more  varied  Mgna  of  acow- 
tiona,  the  interpretation  of  theae  sij^ns  is  beset  with  fallaciet.  fiome  nb- 
aervcn  bare  fuiund  that  a  hemifcction  (in  tlie  thoracic  region)  priMluce^)  Ion 
ofaenaaiioa  on  the  croajeil  side,  accompanied  by  little  or  no  loes  on  th« 
Mme  aide ;  other  ohser^'era  acain  have  liailed  lo  obtain  after  a  hemisectioo 
Htbftetory  proof  of  imy  auch  marked  loss  on  the  croEMed  aiile.  Further, 
large  portwna  of  the  lateral  column,  the  more  internal  pons  adjacent  i»  the 
gray  matter  being  leJl,  have  been  removed  without  any  very  obvious  and 


TUB    BRAIX, 


ceiiAiiily  wiibout  any  la&tiag  defects  of  aenaaiion  on  the  one  tide  or  tiD  th* 
oUwr, 

£  684-  Tli«  f^ltiiica)  hUtories  of  diMases  of  the  cploa]  cinl  in  ntaa  briDg 
to  light  ill  a  fairly  dear  iiiauner  a  f«et  of  fODW  ini(>'>rlHlic«,  tumely,  Uul 
the  Kvcntl  im]iul96i  which  Airia  t1i«  hues  of  Uk  Mvi-ral  kiiiila  afattauia 
of  touch,  h«al.  c»Ul,  and  |Miiu,  and  of  iho  muiiouinr  ttaae,  mn  tranvmil 
along  the  O^rd  to  dilTureiit  wavo  and  pn^umnlilr  bj  diiRMVnt  ■ininu 
For  dtMuuc  may  iiupuir  one  of  ihmt  muationt  and  leave  the  othwv  iolacl. 
ThiM  ca»o>  of  :i|iiitiil  ducuue  are  recorded,  in  which  on  one  aide  of  the  budf 
or  in  one  limh  onHnary  tnctilo  nnwiti'Xiii  M.fincl  ti>  1>o  liltU^  impurMl,  nM 
yet  MnsatioQS  of  pain  vrvn  iil)«ciit ;  ytbua  n  OMillc  vras  thrust  intu  lh«  akia 
no  pain  \tttf  fdt,  th'>iiii;h  the  pikUcnt  waa  airare  that  the  ncc^lte  hai  bm 
presN^d  upon  ibo  i>kin  at  a  particulnr  spot;  and  converMlr  in  otiiercnMt 
pain  htie  been  frit  upnn  the  in»crli»R  of  a  Dcedle,  thi>u);h  mere  ooataet  with 
or  prMBiiro  on  the  tkin  ould  not  bo  appreclAlcl.  Attain,  caaaa  are  reoonW 
in  which  the  ekin  was  teiisitivc  to  touch  or  pain,  but  not  to  rariatioM  vt 
lent perature :  il  i«  furthi>r  stated  that  cases  have  been  met  with  in  «hi^ 
cold  eould  be  appreciated  but  nul  heal,  and  vice  reraa :  and  there  are  Mat 
&cta  which  point  to  senaatiotu  of  pain  heini;  mire  chicly  a.«sociated  wili 
tlinae  of  heat,  and  utclile  aensalion"  with  those  of  cold,  than  tliuae  of  pi'a 
with  thoee  of  touch  or  ihoae  of  bent  with  ifaoae  of  cnld.  ('aoes  of  ffonl 
diaeose  are  al»u  remrded  in  which  the  nmseulnr  seme  ap)>cared  to  bea£bciel 
apart  from  other  senMtiooB.  Weaball  return  to  iheae  loattr^n  later  oe  a 
dealing  nith  thoaensea:  we  refer  to  them  now  Htnply  lu  iihciwin:;  thai  iti»- 
eaae,  limited  at  far  as  ran  )»e  u^certaiiied  to  the  8[>iual  oinl,  may  ulKsd  lb* 
aevenl  at'naationa  aepnratvly.  and  therefore  a^  ta^ntttitig  that  the  ttntH 
kinds  of  inipiil;^,  fiirmin)^  the  lin»o»  of  the  Nevcral  kimU  of  aenxatiun.  u* 
traMniittod  in  diderent  waya  and  f»lluw  dilforont "  paths  "  aleag  the  apioal 
cord. 

Clintca)  histories  mnreover  agree,  at  lenal  to  large  eitcni.  in  ahowin;;  llM 
nhen  the  lesion  is  conlined  to  one-half  of  the  cord,  ike  sensaiiiiMt  affected  n 
the  parts  below  l)ie  level  of  the  leaion  are  chieBy  or  even  exclusively  ihm 
of  the  crossed  side.  But  there  is  not  entire  a<.'cordance,  eajtecially  at  totla 
cro8sin(>  beini;  complete.  And  with  re^rd  to  the  muscular  sense  there  iis 
distinct  conflict  of  opinion  ;  the  nmjorily  of  cnsee  seem  w  show  that  in  ait- 
lateral  disease  or  injury  to  the  conl.  the  museular  sense  in  company  milk 
the  volnutary  inovementa  fails  on  llie  *aroe  side;  but  cases  hare  fam 
recorded  in  which  the  niuaeular  aanae  in  comiiany  wiih  other  aennliio* 
seemed  to  be  affected  on  the  cra«sed  tide;  it  nitwL  be  rvmembered,  howevfr, 
that  il  is  very  didicull  t»  appreiTliite  a  dfticiency  i»f  muscular  sente  miacM 
with  deliciencie*  in  other  utiiiHaiiuns,  and  wa  should  d  priori  expect  the  mia- 
culnrftense  tii  run  pnrulli^l  with  motnr  impiiliu-M. 

When,  howcviT,  wr  appeal  U>  clioi<'al  hi^toriu*  or  indicatiooa  at  to  lb> 
aeveral  |<athii  within  the  Kpiiml  cord  liiken  by  iheie  several  inipuUe*,  tbf 
answer  it  a  miul  uncrrlnin  one,  lu  indeed  might  be  expvctcfl  fnnn  tbe  KM 
often  difTuKe  chnnicKT  of  the  li^i'ins  uf  dtseaw;  and  it  \*  [N)rliB|M  not  IM 
much  Id  car  that  i>n  Nttisfnctory  d<v!uctioas  at  all  can  bo  modo. 

§685.  Whcrihcr  tlicii  we  turn  to  experiments  on  animalt  or  totboitedr 
of  difcaae.  ihc  loachings  with  regard  to  sensation,  in  contrast  to  thnse  wito 
regard  to  voluntary  movement,  are  in  the  highest  degree  uncertain  ao4 
oDMure.  A  few  general  reBeotions  will  perhaps  help  us  to  appreoiali  tbt 
value  of  such  facts  aa  we  poataaa. 

We  have  seen  reason  to  think  that  in  every  movcmewl.  whetlier  voto 
and  of  cortical  origin,  or  involuntary  and  siarled  either  as  n  simple  •. 
redex  or  through  Uie  working  of  some  part  or  otJwr  of  tbe  brain,  the  i 


I 


I 


CUTAXEOUB  AVD  SOUS  OTDEB   SENSATIONS.  8SI 

iiniMiltww,  which  twcep  dunn  the  motor  fibres  to  tba  rousclca.  imuo  mar- 
sliBllnJ  nitii  cixViliiMtled  tram  l)i«  gny  maUer  of  Um  eofd  (lor  lh«  auke  of 
di-nmnt  «r«  nifljr  otnit  the  cranial  nerve*)  from  wlitit  we  hare  cm]l«tl  tbi: 
■i)"i»r  moduinisRia  of  the  cord.  Analoey  would  Iuhi)  up  to  suppoM  th»t  tlic 
nlli-rviii  iiiipulM*,  formiag  th«  baaea  of  Uie  aaveral  ktoiu  of  KDttatiuna,  aiml- 
Inrljp  li;ll  tW  udercnt  librts  to  join  tba  gmy  mutter  uf  tlie  cord  in  what  we 
naf  call  ibo  Mosory  mechanism.  Am)  ^uch  anaiumica)  lexliiiji  iin  we 
pTMKM  tttmt  to  Biipport  thia  view ;  miih  tbc  escepiion  of  the  mciliou  po»- 
K'Mor  Intut,  to  which  we  irill  return  imuKNliatvly,  nil  the  Shren  of  u  piaicrlur 
TDul  M«m  to  end  iu  the  gny  matter  not  very  fur  from  the  eiilronce  of 
the  root.  We  have  seen  tliul  a  ooOrdiuatv  rcllex  ntuvenitiut  may  be  carried 
out  by  at  Ifast  a  few  »e];mei)t«  of  the  conl ;  that  a  reSex  movemi^nt  may 
be  started  by  ctimuli  uf  vnriuuti  kinda  and  therefoiv  prcmmably  by  atTcront 
impuUa  of  various  kind*  ;  and  that  impuUvn  forniinj;  the  baau  of  tli«  iDns- 
cufar  matt  »n  Mwiiiial  to  thv  ciHtnhmitUm  »f  tht;  n]o<reiiMDt.  All  our 
kii»«Iri]Ke  Ko^  t>i  show  that  in  a  r^tlex  moveBienl  carru'il  <>ul  by  a  low  seg- 
■ueiits  lit  ilic  onl,  the  whole  vhaiu  of  nv«ut»  between  thi;  arrival  of  the 
adervni  ImpulaM  along  iba  poaicrior  mot  and  ibn  inuc  of  eHl'rrnt  impubet 
along  tli«  anterior  root  may  be  carriv<l  out  by  gray  niatlor.  and  gray  raattor 
tlone.  We  may  further  infer  tliat,  while  on  ibo  one  band  tlio  hum;  pro- 
cedure miKht  obtain  not  through  a  IVw  w^gmi-tiit)  only  bnt  alimg  tlw  whole 
Itaglh  ol  the  cord,  there  would  bu  an  ndvaiila^^o.  ni'iiiallr  in  rvupect  to 
the  rapidity  of  lran«ni»ton,  in  employiiig  inicriiuncial  ImctB  of  tibraa  b*- 
tncen  tlw  teireral  Kgroent«,  the  advantage  being  greater  the  more  dittaiit 
the  Ngmenla  which  have  to  work  togvlher. 

W'e  might  furtlicr  tuppose  thai  il  would  ho  of  ndvaotag«  to  poaMiai  aomo 
direct  path  bclwwn  the  oercbral  cortex  and  the  spinal  Hanory  mechanism 
iume<lialely  i-onncclcd  with  the  posterior  root,  such  as  is  atl4>r'led  by  tbe 
p^vramidal  tract  between  tbe  cortex  and  the  *puial  motor  mechantum  iuinve- 
ilMiely  connected  with  the  anterior  root,  but  ito  auatoniii-al  evid«uce  of 
•ucb  a  trad  ii  fonhvoming ;  and,  od  we  have  before  remarked,  along  all  the 
traoU  whieh  seem  to  be  aeDaory  in  nature,  in  controat  to  what  takes  place 
in  tite  motor  tracts,  relays  of  gray  matter  are  i-oiuiiiuuliy  lieiiig  iMter|ioLBted. 
The  HH-diau  |KBie(tor  tract,  uace  it  gat  hem  up  rtpienetilalivcii  uf  Miceeative 
DATTM,  prweuis  ilM-lf  as  llt«  nearest  apptuHch  to  auch  a  »eiuury  humologuc 
of  tba  pyramidal  tract,  though  it  emJ*  iu  the  bulh  and  it  not  continued 
directly  un  to  tbe  cortex.  And  pursihly  it  di>e«  play  a  xmieithut  analogous 
|Mrt.  ill  fo  far  uh  it  »erve>  a»  a  Hjiecial  CKnucction  hclnwn  lh«i  brain  aiul  tlw 
whole  tericfl  of  Hpiiial  iiervra.  Hut  we  are  wholly  ignorant  as  to  wlial  il 
mlly  does;  and  whatever  !«  the  exact  nalurti  ol'  I'he  part  which  it  playii,  it 
proliably  has  relation*  not  to  one  kind  of  sensation  only,  hut  to  all  tbe  dittos 
rnt  kituls  of  sensation.  It  liiis  indeed  been  suppiwoi  by  »nM  to  be  csfic- 
cially  a  tract  liir  ih«  impulM-s  of  the  muccular  «en>e;  but  neither  oxpctitneuL 
nor  clinical  study  aflbrds  udiijtmle  jiroof  of  this  view.  The  condition  knom 
w  locomotor  ataxia,  the  sidient  Iralure  of  which  is  1«m  or  impairment  of 
muNular  sense,  i*  avociated  with  diwaM  of  the  posterior  root  and  of  its 
entrance  into  the  cord,  not  with  discBK  oonfinvd  exelurively  to  tba  nmliiiu 
pottetior  ouluma.  Moreover,  the  tract  cannot  carry  all  the  iropulMrs  of 
uiUBcular  tense,  since  some  of  them  must  pas*  at  once  into  the  gray  msllcr  to 
take  part  in  the  c»r>nli  nation  of  reHex  movamento,  aitd  BitHi  tbanftire  travel 
by  librvs  which  do  not  form  this  tract.  tSmilarly  is  tb««  BO  idaqtHte  proof 
ol  the  Iract  tK-iii^'  an  eiclueivo  channel  for  tactiM  or  fbr  pdabl  MflMtiona. 

We  may  alito.  i^rliups.  urge  »iniilur  conBiderattOlM  with  Ttffoi  to  the  cere- 
bellar tract,  which.  thi>ii;{b  Htariiu);  from  a  relay  of  gray  nutter,  is  theoce 
vtlWBXd  to  the  Cerebellum  a  vuiititiuous  tract.     Tlus  tract  also  has  beeu  au|»- 


8A2 


THE    BRAIN. 


pOMd  to  can?  impulaee  of  a  particular  kind,  and  more  {Mrticulnrly  thowef 
tuuacular  aeiiee.  rhere  U  Iras  A  priori  olijectioii  to  this  view,  uiic*  thr  tnci 
Mnrta  iVoui  the  gray  niatier,  wher«  the  iiiipiilMS  of  muscular  eenan  uuiy  hnn 
ulrvuily  (lime  Uiuir,  so  to  sgieak,  loral  work,  and  emis  in  lh(><wri'lH-tlum,  wbirk, 
na  wv  Imve  Ktti,  seems  etJiiecially  coiinei^lod  nilli  llie  (VM>rdiiiu(iun  of  ixii>v*< 
uieut*.  Ilui  M'illi  ri>&pt^ct  lii  tliia  tract  also  neillier  expcriiiK-iit  nor  cliiiio) 
study  al!i)rds  any  clear  and  ilecialvc  pruut'  that  it  is  «olely  or  even  niwciallj 
OMivi^rued  witit  the  muscular  eeii«. 

With  re;;ard  lu  the  aDl*ri>-liiieral  asccudinf;  tract  our  knowledj^  is  tea 
iRi|>erfect  ii>  Juetil'y  us  in  su{>fici»iiuj{  that  it  is  the  special  or  eKclutivc  cbaniwl 
for  any  one  kind  of  seuiiatiuu,  or  imleed  id  drawing  any  cooclusiuti^  at  all 
concern  ing  il. 

But  wlieD  we  subtract  from  the  while  matter  of  tho  cord  ihme  coDtinDOM 
tracts  (if  asvcn<li»g  de)(eueraliun  of  presumably  sensory  or  atlerent  functi-is. 
and  ibe  continuous  tracts  of  devceuJinj^  dc^nerniiun,  irhich  we  may  oooli- 
dcntly  s|>eiik  ol'  as  tuotor  or  at  least  elfenait,  tlH-re  are  leA  only  ibe  fibrts 
which  we  httve  l§5S:J)  Bup|iiiscd  to  l>e  longitudinal  oomrataMiral  or  lot^r- 
iiunciul  it\>n*  between  nurciwivc  mij^metits.    We  are  thus  driven  buck  looar 
titrnsr  conclusioti,  that  seiuury  impiiIiM<*  ftam  either  by  the  ({my  nialtn 
alooc,  or  by  a  seriu  uf  tnvjm  us  it  neii>,  by  relays  of  gray  matter  cuniMvtd 
by  internuucial  tracts  ut'  lilins.  whuni  It-iigth  «e  eaiinul  ssoertiun,  but  «liitli 
niay  hv  nhort.     That  Hurh  inli-niuncinl  tracts  intervene  is  rendervil  [irubUiW 
on  ihi!  one  hiuid  by  the  fnct  tbitt  sectiou  of  the  while  inalter,  leaving  lJb< 
gray  nmiicr  iiutou<-hp<i,  doni  ntli-rt  M-ii.-<ali<inK,  nnil  on  the  other  h«ud  by  thr 
lact  that  the  acverul   kiudn  of  n'li^titii'u  apjH-ar  tu  iravtO  along  the  card  b« 
sopurutc  paths,  or  al  ttuu^l  may  in:  nrpiirnti'ly  blockvil.     It  t*  uf  coursr,  as  as 
have  already  urf^eil,  p<irsilde  thai  the  eUcct  uf  a  section  of  n  tniot  of  Hbm 
may  not  be  the  mcn^  bluck  due  to  Iinss  uf  continuity,  but  somv  ac-tton  tm  lb 
gray  luallor  nilh  which  r.ho  tihre?  are  cttiinectcd,  whereby  that  ^ray  nulicf 
lails  of  ite  usual  functiuns  and  ceases  to  carry  unmnl  the  seosirry  impiibn 
reaching  it  from  beion' ;  it  is  alsii  iHtwible  that  tliis  or  that  leaioti  of  iliMwit 
nrny,  directly  or  indirectly,  allect  {larlicular  parls  of  the  gniy  laittler  st 
allect  llie  gray  mailer  in  a  particular  way,  so  that  a  ocrlain  kind  of  maairj 
impulse  and  nouo  other  is  blocked.     Ou  the  oilier  hand,  we  have  reasuu  lii 
ibink  thai  the  rate  at  which  impulses  iravel  along  the  gray  uiaiter  is  rm 
slow  com|>are<l  uiili  ihat  along  nerve  fibres;  and  in   the  striiftgic  for  lin 
rapidity  of  Iransniiiviuu  uf  nervous  imjiulscs  is  of  great  imi>ortaiice.    ilesot 
the  view  that  ihe  iulcinunciul  lihrc=  intervene  has  more  to  cuiumeitil  it ;  it 
IK  moreover  to  a  certain  extent  dupportei)  by  clinical  hinloriee.      Itiii,  it'  «t 
ucoeut  litis  view,  ne  iuii«t  at  the  mitiie  time  admit  that,  in  auiiiialj  ai  leau, 
tlio  Itne*  provided  by  the  iuiernuuciid  tracts  arc  nut  rigid,  thai  within  limiu 
and  under  circuiiHianccF  alieniiiUve  luules  are  poasible. 

§  686.  We  may  here,  [lerluiiM,  laise  ouce  mora,  and  this  time  more  pniai- 
odly  than  hell>re,  the  duuhl  whether  we  are  jualilled  in  auiiming,  a*  «( 
gcncndly  do  iin^uiiie,  lliut  the  events  which  take  place  in  ibe  tiltrss  ii»- 
nceling  relays  ol  gniy  uiaiti-r  wilhin  tbe  centr:U  nervous  *yaii-iii,  arr  exaetiT 
the  same  nx  tliow  which  take  ]ilnce  in  tbe  tibrtii  of  nerves  outaiile  thr  nntrsl 
system  during  the  piuBiige  nf  what  we  call  u  iiervouH  impiiW.  Mini  of  v«r 
knowledge  ol  a  ncrvoua  im|>uliM!  ha*  been  gained  by  ibe  «lndy  of  tbe  tuudir 
nen-e  of  a  mnsclcnerve  preparation.  Our  knowMgc  uf  llw  pnicw^c"  in  at 
lercut  nerves  is  mucb  mure  im  perl  eel ;  but  llirreare  nuuiy  facts  wbieb  al  Irhs 
•nggoal  tbat  the  molecular  event*  conslilnling  an  allen-ni  impulse  along  sa 
allvrcQt  nerve  arc  dilfim.-til  from,  uud  probably  more  cvmplicate^l  tbun.  ili^as 
constituting  an  elfcreitl  iinpulM;  ntong  an  eHenMil  nerve.  And,  with  regard 
to  th«  |>romiuu  taking  plac*  in  fibres  witliin  the  central  nervous  system,  a* 


OPTANEOl'a   AXD   SOUS   OTIIKR   SENSATIONS. 


863 


I 


ITC  liArtllj  imj  exact  oxpcriiDentol  konnlcHgv  nl  nil,  It  luM  l>oou  matii- 
tftiiwd  by  iDftoy  nbwrrcn  tbat  not  Olilj'  ibc  gray  mntt^r,  l>iil  nUn  tli<i  Iriii-O 
of  wliilc  loatUr  in  llio  xjiinal  cord,  while  tlii-y  arc  m|iiil>l<-  »(  conveying  ini> 
pulM-s  in  one  (lireclioti  ur  the  other,  nrv  int^iniihlo  (if  b<:iog  so  cxrio-it  by 
urtilicial  sliniuli  M  to  g«ncrflt«  next  inipulsca.  Then  obwrvera  mntnliiin  ihitl 
nlifti  niuvcmenis  or  sign*  of  »eii«iitioD  fvllow  tbo  direct  slimulKtion  »f  varimi* 
parl«  of  (he  cord,  tho  cfl(>c[ii  arc  due  to  ixcuiug  motor  I3br»  or  cnloriiig  win* 
Mtry  libra  bmving  bei^u  riiniiiliiled,  and  niit  to  a  aiiinulBtion  of  thv  intriniic 
suntance  of  ib«  puri^  tbomsckn;  thoy  pmpoM  nccorditigly  h>  call  ihoo 
part«  "  kinesodic '  ami  "  iCsthModio  "  ra<(>ective]y,  that  is  to  say,  serving  m 
patba  lor  inotiir  oraemory  impulses  without  being  themsolnM  either  motor 
or  aensory,  Tlie  i<vid«ac«  on  Ihe  nhole  goes  to  show  that  this  view  in  n  mis- 
tokeii  ooe;  that  the  vurious  tracts  of  the  spinnl  cord,  like  the  pynimitlal 
tract,  and  iitdeed  other  [mMs  of  the  bruin,  are  excitable  toward  ariitii-inl 
stimuli.  The  question  caiiuol,  huuever,  bo  considered  as  definitely  dosed ; 
aad  t\*e  very  fuut  ttuil  il  lias  been  rnised  illustnitea  the  point  on  which  we 
are  now  direlling.  We  may  further  quote,  in  similar  illuairulion  of  the 
«rae  point,  the  fdlowing  rt'tuarkable  fact  wiiich  waa  obmrved  in  the  series 
of  ex|wriinenie  referred  to  in  ^  G6i  un  the  eifecta  of  repeated  hemieection  of 
the  spinal  eiird  in  duifs;  The  animal  had  partially  recovered  voluntary 
muvemeuiii  in  hia  hind-liiubit  utter  a  ibinl  heiuitiectiofl  of  the  thoracic  coru, 
and  yet  uheii,  at  his  ileatli,  a  strong  tataniuos  current  iras  directed  tbrouch 
lliu  Bulb  und  cvrvical  cord,  no  moveineats  of  tbe  liiod-limbfl  followed;  tna 
impuhea  started  by  artificial  sttinuUtion  could  not  paaa  the  bridge  which 
auffioed  fur  rolillunal  impuUea  of  natural  origin.  It  is  not  too  niucli  to  say 
thot  our  exnerimeutal  ItuowMve  ta  to  the  eveuls  wlitcli  aocoutpany  tlie 
activity  of  the  strucIurM  within  (lie  c«nirul  nervous  system  it  almost  entirely 
limitni  to  llx-  rccn^iitiDii  of  the  "  currvJiIa  of  uclioii "  referred  ut  in  $  651}. 
We  are  already  going  beyond  our  lelhur  wbvu  we  umunie  on  the  straigth  of 
this  that  the  proMwi*  started  in  the  fihrva  of  the  pyramidal  tract  by  artifi- 
cial stimuliition  nro  in  all  rcspM^ts  idculii-Jil  with  tli<>»c  stattcd  in  the  libres 
of  a  motor  nerve,  \^'e  arc  going  still  more  bcywd  ■>ur  tether  when  no 
assuntv  Uint  the  proccwcs  started  in  the  MiinC  pyramidal  librcs  n»  the  outoimo 
of  nnturvl  events  in  the  motor  cortex  nrti  of  the  same  kind.  Ilui  thcw 
anuniptions  are  trifles  cunipnrcd  with  ilic  nsfumption  that  the  evvnl»  taking 
place  in  the  fibres  of  tbe  optic  riulijtlion  |Misung  from  (he  pulvinar  to  tbe 
ocxripiial  cortex  are  identical  with  the  events  taking  placo  in  thi.-  tibn«  of 
the  optic  tract  on  the  way  to  the  pulvinar,  or  that  the  events  Intvclliiig  along 
the  Bpiiial  cord  to  the  bruin  as  tbe  result  of  a  prick  of  the  little  finger  are 
idfuticiil  with  those  which  the  prick  has  HttLried  in  tho  fibres  of  the  ulnar 
Derve.  Of  the  latter  events  we  know  a  little ;  of  tbe  former  events  we  knoiv 
nest  lo  nothing.  Aod  we  may  here  ask  tbe  question,  WluU  is  the  meaning 
of  these  continual  relays  of  gray  matter  alouj;  tbe  ecnsory  tract,  unlees  it  tie 
that  at  each  rtlay  *>imtf  tranlfuriualion,  some  further  elaboration  of  tbe  iiu- 
pubea  takes  pUce.  until  what  were  the  relatively,  but  only  relatively,  simple 
impulsw  along  tbe  libres  of  the  peripheral  nerve  are  by  successive  ste[iB 
diangeil  iu  the  complex  events  which  we  call  a  cAnscioua  sensation?  This 
is  what  wu  had  iu  mind  when  we  gave  ($  G63)  a  note  of  warning  ooncerniug 
ibcdungtr  of  considering- alt  the  events  iu  tlte  central  nervous  system  at  cither 
DMior  or  aensory  in  nature.  It  in  jierhupa  not  an  exugKeration  tu  rv{>n3iunt 
the  views  of  some  olisen-ers  a*  if  tti«y  Huppa»d  that  ult'ercni  impuli-es,  suy 
tactile  impulMS,  U>at  i»,  impulsca  eventually  giving  rue  to  tactile  sensations, 
travelled  unchanged  from  the  skin  to  tbe  cortex,  and  there  suddenly  btus> 
•omril  into  sensations.  If  such  a  view  were  trae,  undoiibieally  tlio  chief  liuk 
of  jihysiology.  alnMst  tbe  uuly  one,  would  be  tu  asc-rtnin  Uiu  trout  uk 


TSC   BBAIX. 


or  patk*  mak»  tat* 
praMcM*  w  to  vktt  an 


which  Uicae  impukM  {MUMd.  Bat  iC  os  ito  Mkcr  1 
urged  biTe  uijr  real  fi)uDiIaiii>ii.  the  humom  of  ti 
inogtiiAcuiee  eumpuvd  KJih  ih«  altaoK  gaiMAtJ 
the  KTeral  ciuuigca  bj  which  simple  UBpalm  arei 
tiona,  uid  when  and  bow  the  diaag^  are  eAend. 

{U7.  SeeiBg  bow  UBaiisfaMary  ii  oar  pnaeM  haaahiJm.  wiik  rvgaH  M 
tbetncUor  pathaofaeocatiitiif  id  the  rdaurelT  uipla  tfcMl  eoid,  u  vooU 
be  maloi  la  aUenifit  any  dtanuoioa  u  to  thcu-  patha  t>  iW  mch  ■«■ 
eomplez  brain.     If  it  be  ptDbaMe  that  tbe  prntrnge  it  aSeeud  bf  wbiyi  «f 

Ef  iBau«r  in  ihf.  forruer,  the  aarae  ra«th'vl  ■•  aocb  Mea*  frnfeaUa  M  tbt 
«r;  and  if  iKJiUer  exiKriment  itorclioical  Modr  lbr»«a  wieb  HBta«a 
ibe  pnih  up  to  Uie  bulb,  theaa  csimot  be  cxpcdM  le  ci««  flBScb  Mpin 
Ibe  maxc  oigny  matter  and  Rbrei  by  wbldi  tbe  balb  it  jmad  le  tbe  obRM. 
Th«  iwveral  (lu'Sncd  areas  or  collcOioD*  of  rnr  matur.  and  tba  antnl 
■Inuuk  und  tract*  of  fibre*  which  w«  briefly  dcacribcd  in  a  pcrrioda  HOiiiB, 
mtitl  hare  of  courte  a  meaning ;  but  it  may  be  deabted  wbtcbv  m  1mm 
even  to  much  a>  ■  cnrrcet  glinama  of  that  nkcasiaf  ta  aoy  ooe  ease,  ff  m 
txoept  tboM  which  urn  in  immediala  conaecUoa  with  tbe  cranial  iMfT«i  lal 
tbeir  nuclei.  Seeing  that  iho  thalamus  appean  oo  tbt  ooe  band  to  be  am- 
occtcd  with  all  or  nearly  nil  parte  of  the  con«x,  and  en  tlkt  etbar  ktai  It 
■trve  a*  the  front  of  tbe  tegmental  ayatem.  it  it  icmpltag  lo  aappoea  Miai  il 
playa  an  imporunt  pnrt  in  eeoaatloiia  penaining  to  the  body  gaaerally, « 
port  of  it,  the  pulvinar,  cortninly  'loee  with  refcratee  to  tJie  special  Moaa  of 
sight ;  bat  we  uve  no  decvivo  indications  as  to  what  pan  it  play*.  And 
tiw  part  which  it  plnjrs,  whatever  that  nay  be,  is  not  aa  exdocirely  eaMHy 
one,  noce  both  expenmental  and  uorlrid  Iceioiis  of  the  tbahtaae  are  apt  to 
produce  disvrdera  of  movement  as  well  as  oth^r  elTerent  eflecta,  We  oo^ 
perha|)e  to  >ay  tbe  pArU  which  it  plar«,  fur  it  is  a  eonplex  body.  baTJpg 
uanv  tie*  and  prolialilr  irerr«riiiiiig  many  dutiea. 

Tne  CUR* [lieu '•UK  lillei  u)cuiu,  weming  oa  it  does  to  be  a  special  inlenmacii) 
Imct  conne<:lini[  what  up|ienr  tu  be  n*ure  paHlcuUrly  aUvreot  or  ecnsaer 
ports  of  the  bulb,  such  ■*  tlie  grucile  nod  euneate  nuclei,  with  rartOM  paiH 
of  tbe  middle  brnin  and  pruluiblv  with  the  cnrtvs,  preacnta  iiarlf  a*  a 
prolmblc  piilli  of  xcnEatiifiu  ol^  vuu  kiud  or  anotlwr  frooi  tbe  budy  at  latp; 
tbC'iuirniw  iMlh"  of  the  uiutomicid  programme  (§  681  r;  but  b  reftrente 
to  this  liKi.  Govond  its  prubable  oonuection  with  tbe  auditory  lefiaaliwi 
(i  078i,  we  Ucit  eridenee. 

A  i'»iv>{>ieuuus  {nrt  of  ibc  brain,  namely  the  oercbellun),  natarally  anm 
our  attention  on  account  of  its  large  connecttoor  with  what  appear  to  W 
a^r«nt  siructures ;  in  the  luiit  lorn  leal  progrmmmc,  we  called  it  "  tbv  bnod 
pnlh."  By  the  cerebellar  Intel  it  has  an  uncraacil  grip  upon  what  ia  pncH- 
cally  tbe  whole  )eii;;th  of  thu  spinal  oord  ;  by  th«  olher  constituents  u(  Ik< 
inferior  peduncle  it  iins  a  like  uncrossed  grip  upoti  what  appear  to  be  aObtat 
etrncturca  in  the  bulb,  the  gracilc  (uiu  cuncalc  niideitaa  wdl  as  on  iht 
eighth  (vcMibuIar)  nerve  and  pnjbiibly  rcprcscnlntives  of  other  aStraal 
cranial  nerve*  :  it  haj  furllier  a  crosx^l  grip  thmiigh  the  grncilc  and  cuncat* 
nuclei  on  the  alTci^ut  poaterior  coluriius  of  the  whole  curd.  Il  is,  of  eounc, 
possible  thut  tbe  (>erel>ellur  tract,  though  id  itself  oncruased.  Inrs  its  hand, 
DV  nienni  rtf  the  veaioutiir  cytinder  fur  instunce,  on  impulses  which  ban 
nlrendy  rro*scil  fh>n  tht  pveteriur  roots  of  the  other  side ;  fur  as  we  hart 
seen  the  evidence  BS  A  whole  ahows  ilmt  acnsory  impulses  do  cross  over :  bet 
neither  has  the  craesing  of  the  immilaee  tieen  definiiely  pruvc<d,  nor  has  the 
path  of  tlie  cruuiDg  been  clearly  oeuoostrated ;  while,  on  the  contrary,  tbt 
bbree  uf  the  audltury  nerve  which  [>at«i  to  the  eereliellum,  and  whidi  us  we 
have  >uj{geeted  ($  Ul-'J' '»"}'  I''  coni{i<iied  to  an  outlying  port  of  ifie  oer^ 


>TaKB  ABPICTS  OF  THS  TOXCTIONS  OP  TUB    BRAiy.      8fl3 


bcllsr  trad,  ccrliiinir  continue  uncroceed  into  the  peduncle  of  tl)«  buiu«  tlchi, 

Wv  mity  coocludfl,  tlierefore,  tliat  tlie  ties  of  the  cersbelluiu  with  tbc  |io*- 

irrior  nM(»  SI*  botb  cnaBM)  and  uncroeaei).   And  we  may  revard  iIiIh  dmiblu 

ugrin  of  ibe  cefebellum  on  ibe  curd,  (hid  Rrip  on  botli  tide*  of  it,  an  lui 

Eduitionnl  evidence  that  llie  ties  of  tbe  cereoelluni  with  the  *|>iDal  ooixl  nn 

"not  iDcrelj-  for  tb«  purpose  of  servinj;  as  the  diaou«l  fi>r  tlie  impultca  uf 

DiUEculiu-  Hn«e,  but  are  tbe  means  by  ubicb  the  cerebellum  tmnnfunus  or 

elnburales  nnawy  impidBcs,  uot  of  luuaculur  »en»e  alone  or  cii'wi\y,  but 

pmhably  of  all  Rjods,  in  order  lliat  ibtv  mny  lako  part  in  cerebral  upvrn- 

lioDs.  of  nhicli  the  oodrdioacion  of  buddy  juovemenia  may  be  one,  but 

probably  is  only  one  of  Mveral  or  even  of  many. 


SOUE  OTBER  AsrECTB  OF  TBE   PcNmOXS   OF  TIIK   BlUIIC. 

It  ia  diffioult  toaaT  anythiii]^  duiiniu;  concvrniti);  tbo  Iransiaission 
Bury  impulaea  and  the  dt^vrlojmimt  of  »en»Htiuni;  it  is  siill  more 
<Iifficiilt  io»ay  auytbingderiDiio,  bcvond  what  ha«  l)e«ii  already  iucidenlully 
aaid,  cunrcrniaj;  tbe  parut  [ilayvfl  in  the  work  of  lb«  brain  l>y  the  various 
aggTvgntkMU  ol'  sray  matter  and  tracts  of  fibraa  forming  the  middle  part  uf 
llie  broiH,  Neiilier  ex])tirim«nt  nor  clinical  study  has  as  yet  nSurded  any 
ckar  or  i>ure  lading. 

To  what  bas  alivndy  been  nid  abuut  the  oerebolluin,  we  may  ad<l  the 
fidlonini^: 

Elrctni.'al  stimulaiion  of  the  surliice  of  the  cervbelluoi,  in  the  monkey 
ud  in  olhvr  luiiniulo,  has  le^  to  movenuints  of  the  est*,  and  of  oth«r  parts 
of  lh«  h«ad ;  but  we  cannot  from  aucb  results  draw  any  satiafactuiy  iu> 
fyttaeta. 

TUe  removal  of  various  part*  of  tlte  cerebellum,  t«pectally  of  the  medium 
|»r1a,  has  led  to  a  want  of  coitrdioatioD  in  liudily  moveiii«ula ;  and  an  uu- 
ateady  ijait,  due  to  a  like  waui  of  Rde(|Uat«  cu&rdiuution.  i>  a  frequent 
syoijnoiu  of  cerebellar  di»«'ase.  But  tbe  inco&rdinaiion  which  makta  its 
appearanco  inioiediately  after  reinuval  uf,  or  injury  to,  tlie  cercbolluni  iitay 
ervniually  disaptiear,  even  l)i<iu>:h  lar^e  [>ortiun»  have  been  removnl ;  and 
maay  caves  of  exlen^ive  cerebellar  disease  have  been  recordnt  iu  which  the 
noat  perfect  ciHtrdJ nation  of  ninvetuents  was  retained.  Hcncn  the  ttsults  of 
expeniuenial  auil  clinical  ntuily.  while  un  the  whole  aupporting  tbe  godcIu- 
•ion  that  tbe  cerebellum  has  in  w>iue  way  lo  do  nitb  coSrdination,  throw 
little  or  iw  lif^ht  on  the  exact  nature  of  the  part  which  ibeiH^ui  plays  in 
the  Complex  proveas,  hut  f>erha|H  rather  vbow  thai  we  ore  at  pnaoat  Hholly 
Ignorant  of  buw  cuordiuatiun  is  bmuKht  altout. 

Many  liyjiutbeMS  have  be«u  put  ti>rnard  as  to  the  work  carried  out  by 
the  c^ivlwllum,  but  none  of  iheMi  can  be  ttaid  to  have  an  adct]uate  buais. 
Am),  iixleed.  if  there  be  any  value  in  the  rvdections  wc  have  repeatedly 
made  iu  previuua  ]>s^,  the  ^diysiulogist  ought  not  to  use  the  words  "func* 
liana  of  Iliv  eerebellunt."     Iruni  a  phyMolngical  jiuint  of  view  it  is,  so  to 

rk,  •  mattvr  of  accident,  that  vaiiuus  alructurx^.  the  mla  of  rariotis 
li'ilugical  pruct-aiK'a,  have,  front  mur{iliulouical  causes,  been  gathered 
togvilii-r  into  llic  hiidy  which  ■ualonii*li>  call  the  cerebellum.  The  task  of 
iIm;  [•byatiiliitcixt  is  lo  unravel  the  tim  binding  these  various  cerebellar  striic- 
turea  with  oilier  parts  uf  the  ceJilral  nervous  systwrn,  and  so  nilh  various 
parts  of  the  hudy  at  lar;ge. 

We  must  cmtieiit  oureclvea  Iwro  with  calling  altenlion  to  two  or  tlinio 
a4l  anil  suggealive  facts  ooncarning  its  »truct«ire  and  oonoectious. 
iu  the  first  place,  one  striking  fact  about  Uk>  cerebellum  is  tbe  very  Inrgt 

M 


ma 


THE    BRAIN. 


development  of  comniu«ural  fibres  eonnecting  tocher  tbe  fuputfidAl  giwj 
matter  uf  tbe  !«-»  beinuphem  for  tlie  grudter  port  of  Ihcir  pstent,  aai! 
pnwrig,  not  onlv  lliri>ut:h  the  ponir  (^  t>^)  v  pan  of  the  niiddlA  pnliineir, 
bill  nl«o  tlinxign  llie  ruedian  vcmiui.  Thi*  gnml  vmamimaro  it  noond  onlt 
to  lliC  c'^^t  nilliiral  eoiiimiMurc  (if  tlu- cenbriim:  iiml  fna  th»  fiut  tku 
ine<li)in  inioii*  uf  ilie  rtrrebt^lluro,  th<js«  nliicb  iln  niiicrt  dnnun  to  thi* can- 
miwiire,  &rc  lb«  niii»t  I'tTei'livc  in  enuning  incourltniilion  hdcT  iomd  nwr*- 
menM.  m-  may  infer  (biti  U  in  wimc  wmr  pUya  nn  hoportsnt  part  In  w 
ordinntion. 

A  »rcnnil  striking  fiict  i.-  nne  on  which  w«  have  tilrend<r  juel  dmlCllw 
connoclion,  ebioHv  nii  inicronuMl  one,  thmugh  tho  inferior  peduDcte,  with  tho 
atfcrent  slrucliirm  tif  llie  bulb  and  »piniiT  e'lrd.  Wc  mny  no«  mdd,  Ihu 
th«  fibres  of  tbi»  pediinelr  iitiming  into  lh«  centn^  of  the  tvhiie  malU-rnr 
Iho  coreliflbtr  heniinphcre  i>t  llic  «ini«  side  encluM'  the  gray  matter  or  ife 
niiclci»  (leiitatus  nail  appeiir  birgcly  to  end  in  that  boily,  though  aomtjm 
on  to  Ihe  vcniiin. 

A  third  Mriking  fact  '»  tho  connection,  Ibis  being,  m  far  as  we  Itan*, 
wholly  a  cnvscd  one,  thiniigb  the  pons  nnd  pee,  wiih  tbe  eerehral  (i<nu, 
both  of  the  cxlreiDe  frunial  region,  and  of  the  U-mporo  ocei|iiiitl  regi'xi.  nd 
putU'ibly  or  even  prnbnbly  with  lunrc  scatlervd  curtieal  elenit^nta  nf  iW 
parietal  (motor)  region.  This  connecliDn  is  one  between  eortex  and  cixtn. 
or  ul  least  between  cerebral  cortex  imd  cerel>elliir  6ii])eflicial  ^rny  natur, 
for  the  fibrce  of  ibe  middle  peduncle  pacing  fraia  the  gray  matter  of  th( 
piius  which  Hervcs  na  a  lelay  end  in  the  surface  of  ihe  lateral  bemioplitrc nf 
the  eerebellum.  The  frcinliil  citrlical  tibrea  pacing  to  the  pea  have  ■  d» 
Bcendiug  degeneration,  that  is  from  ihe  cortex  l(>  the  poait,  and  wn  mat 
pnbubly  a»iim«  that  the  similar  tetDjwro-occipital  fibres  similarly  derviMnM 
downward  to  the  puos  (^fi.lS).  Fmm  thia  it  huti  bei-n  iulVrred  iliHl  lim 
oenrbro- cerebellar  roniiertion  carries  iinpulves  from  the  ecnittr.ll  mrux  W 
Ihc  ccrvbelluin;  and  it  had  biH'U  t\)rlber  iDlVrreil  that  ihvw  ini|)ul*e«  are  rf 
the  nature  of  motor  iinpiil:ii;4^  A*  we  bare  more  than  oiico  tirgt<d,  lb* 
character  uf  drgvoenition,  Ihnt  ia  whether  "axcending"  nr  "  dcKy-oding,"  il 
not  n  vutiKfactory  priinf  of  the  dirrctinn  taki-n  by  impnl»c« ;  but  il  it  pw- 
bnpa  of  more  imprinaiicc  tn  rvmember  thnt,  ax  webarealiu^urgcvl.  we  liarww 
right  to  aiuiime  thai  the  tiiijnilmTS  pa.-«ing  along  nich  a  tract  m  the  omIb 
tineilioa  muKt  be  eilluT  st'iisury  nr  lunlor,  or  indiwd  that  auL'h  a  tract  gem 
as  an  instrument  fxr  prinbu'iiiK  etfecl*  in  one  direction  only. 

That  during  life  tUc  tibrc--  ot  which  wc  an-  tipeaking  »crve  w  an  impr-rfoM 
chain  by  whicn  cerebral  enriot  ami  i-iTelwllnm  aflpct  ihono  Ihe  oibcr,  lli»fi 
can  be  but  HUlc  ibmbl;  but  me  Bri.i  whully  in  the  dark  as  to  what  rvallf 
takes  place  along  [he  MIikk.  Wr  have  Mvn  i  §  -''.'A )  reason  to  think  that  lk> 
brain  may  and  nwf  exert  an  inbibiiory  initiienec  over  Iho  npinal  roni ;  wl 
Ihe  niechaoical  certainty  with  which  nii  iinimal  deprived  uf  ita  ceretnl 
hemisphere*  re»ponils  to  slimiili.  in  contratl  lo  the  untTrlainty  attending  \kt 
result  of  Miniuli  applied  lo  an  intact  animal,  as  welt  as  all  lh«  ex|ierienoe«f 
our  own  daily  life.  «howa  that  the  Cvrebral  coriex  can  work  iu  an  inhilWLMT 
manner  on  other  nans  of  l  he  brain ;  the  remarkable  **  forc«d  raitveroenlf 
on  which  wc  dwelt  in  a  previous  section  teem  in  some  iustaneea  lu  be  (In 
r«snlt  of  the  abrupt  trnap  of  some  inhibitory  bond.  Cunvcraelr  all  then- 
[wrienco  of  our  daily  life,  many  of  ihe  pheoomena  of  lh«  contlitiun  ki>o«B 
as  hypnotism  and  of  allied  conditions,  as  well  as  rari^us  esperitDeotal  n- 
suliii  Kuch  SB  thot  ijuoled  in  !i  t'll'i,  where  a  sensory  impulse  aeenia  to  tnhibli 
Ihe  aelivily  of  a  motor  area,  show  that  the  cortex  may  itself  in  turn  be  in- 
hibiied  by  other  iiarls  of  ilie  central  nervouaavslem.  Uul  we  have  at  |itMMil 
no  eatiafaclnry  indications  us  Iu  the  paths  of  inhibitory  iinpulMs  or  M  to  bn 


ASPECTS  OP  THE  PUKCTION'S  OF  THE  BRAtK. 

inhibition  it  brought  about ;  nor  linvc  trc  any  proof  that  the  ccrebo-ccrebellnr 
livct  U  ■»  iubibitorj  one  in  either  flirection. 

Wo  may  ailtl  (hat  tomn  of  the  Hbm  of  th«  niich]le  iiediincic  appear  to  he 
Dritlwr  colli niiim ml  imr  cnnnortod  «ith  the  conical  tibrc*  in  iImi  pn,  but  tu 
rnd  in  other  «n_vii :  nnil  Irncln  buve  Ih-i-ii  (IcoLTiht^  n*  continuing  onward 
•DliM  of  the  ccn-tirllnr  tiliri*  nf  the  iniil<il<>  jMriliincIo  on  the  oim-  hniiil  upuiinl 
bimird  ihe  cen'bmni,  nint  <in  the  »lhvr  liftin)  il'>wnw«r<l  lowaril  ihn  «]>i[i»l 
cord.     It  ha«  Itc^n  rurilur  nrgnl  ihul  lb*»c  tracts  nm  cflerr'nt  in  functioti. 

Lastly,  wc  msy  ciill  iittt-nliiin  t«  ihc  supcHor  peduncles.  Ties?,  which  as 
ir«  hai,**  tfvti  apiM-nr  to  com*  largely  from  the  gmv  matter  of  the  ducIcu» 
dentatd*  ami  lo  cnti  in  ihe  teemnitum.  largely  in  rho  red  mictciis,  mny  be 
regardwl  a*  cmi'tiluiing  ihroiijiD  f  he  reluy  of  die  fninl  pnrl  of  the  (cKraenliiTii 
another  tie,  presumiihly  of  adilTcreiit  naliirr  from  the  foregoing,  between  the 
nTcbellurii  and  the  cortex ;  ind^-ed  it  iiFcd  to  bo  •'n)le<)  the  [ir^iceaaiifi  u  cer«- 
bcllo  ad  cerebrum.  It  is  an  obvioui'ty  cr<»guHl  tnicl  (Fig.  If  I,  •SV)  ;  i  I  con- 
nects one  nueleim  dcnlatun,  and  to  presumably  by  that  relay  the  fibres  of  the 
inferior  peduncle  ending  in  that  boily,  and  perhaps  other  fibres  uroceeiling 
from  the  suiierficinl  gray  mutter  of  one  side  of  the  eerebellum,  with  the  red 
nucleus  and  other  parts  of  the  tegmentum  of  the  crowed  side,  and  thui  with- 
the  corleit  of  the  crome'l  side.  It  has  been  siippi^seU  that  the  direction  of 
inipuba  pvsing  atong  it  is  from  ihe  cerebrum  lo  the  cerebellum,  but  we 
hare  no  clear  proof  of  thia;  indeed,  as  to  what  it  doei,  ti'e  have  no  aatis- 
foctory  evidence  either  exfwrimenlal  or  clinicnl. 

We  may  here  incideiiliilly  remarlc  that,  in  cio.tequence  of  alTcreiit  tmcts 
being  trace<l  to  or  toward  the  tegmentum  and  of  the  shiirp  contrii»t  pro* 
•HilM  betwc«u  the  tejfmemum  and  the  ooD.tpiciiouMy  nl'l^t^  pvramidal  tract 
in  the  pea.  the  vien'  has  ^ined  ground  that  the  tegnientiim  u  OMDtiallr  n 
•maory  stru^tun^  lint  there  does  not  ap]irur  to  be  iidei]uaie  evidence  eitner 
cliiiiail  or  esiH-rimi-ntid  for  iiiich  a  cjorloMoii,  The  (balamus,  which  n'o 
bnvv  rvgnnled  nt  ibc  front  xo  lo  epenk  of  the  tegmentum,  euniiDt.  as  we  have 
already  urge<J  (SH«i),  In-  roniirU-m]  cxcliiaively  or  especially  sensory.  And 
many  of  the  lie«  of  the  tegmentum,  such  ns  the  nbrva  from  the  corpora  striata 
ending  in  tW  suUtantiii  nigrn,  fir  (bin  may  be  considered  as  piMjieriy  belong- 
ing to  the  tegmentum,  are  of  the  kind  which  we  may  suppose  to  be  eSereni 
or  motor.  Indeed  we  may  pnibnbly  reganl  the  wbow  tegmentum  as  beioz 
broadly  the  aiialogue  in  the  forward  acgmenta  of  the  cerebro  spinal  axb  m 
butb  tlie  anterior  and  posterior  gray  matter  of  the  spinal  segments  behind. 
■  TboUEh  we  are  thus  in  the  dark  coneerning  what  goes  on  in  the  cerebellum, 
UtBUty  M  Worth  while  to  call  attetition  onoe  uion>  to  the  remarkable  char- 
Ipetenof  the  superlieial  gray  matter  ($049).  The  many  [i»inu  of  rvM-m- 
pUanoe  between  it  and  the  eerebrAl  cortex  cannot  but  aujjgcit  that  th(<  i>r\i- 
Dtttat  taking  place  ia  it  have  aume  analogies  with  cortical  event*.  And  it  is 
at  least  a  fact  of  annie  significance  that  congenital  deficiency,  or  etrojihy  of 
ttie  cerebral  heuii^pliere  of  one  side,  U  fr^]uently  ac<rompa»icd  by  a  C«irrc- 
■powiiDK  delii-iituoy  of  the  ef<i«sed  ci'rebellur  lieinMphere. 

(688.  Both  the  anterior  and  nnslerior  <.'iir{>oraijuadri;{i^niina  arc  complos 
tn  atfucture;  not  nnly  do  ihi^y  djSer  from  each  other,  but  bIki  in  each  the 
grvv  matter  dilfen  in  dirfprmt  pnrta,  Ixith  an  lo  its  nature  and  nppeuraiiea 
■na  as  to  it*  connci'lioaM  witli  tracts  of  Hbnat.  If  we  have  little  right  to 
•peak  of  Ihe  "  functions  of  the  cerebtrllum,"  wo  have  even  Iwa  right  to  speak 
Of  the  •'  fuactioiis  of  ihe  corpora  ((uadrigeminB"  or  of  either  pair  of  them. 
The  anterior  pair,  as  wo  have  seen,  ba*  tu  do  in  s»me  way  with  vUion  ;  but 
we  have  rranm  to  think  that  a  part  only  of  the  whole  b»<ly  is  thus  concerned  ; 
and  there  is  some  foiindilion  for  the  view  that  of  thi4  pirt,  ooe  portion 
balungs,  ao  to  sfieak,  to  the  optic  tra^t  an  I  another  porltou  to  tlie  ooftioal 

I 


668 


TMK    BtCAlN. 


fibre*  of  tli«  optic  railUtion.  Pomblv  «lill  aiMtber  (Mit  b  coacwoed  in 
liriiigii));,  ns  we  have  ($  G7-1)  eug^CBlcu,  Ttniftl  impulan  to  bear  on  the  iw- 
vnliiiHlion  of  itioveiii«iiu. 

Sliiniilatioii  of  tlio  Hurfnce  of  the  poslcrior  pair,  boido  giviDg  ria*  U 
inovi-nii-Dt»  of  viiriouit  |iuriB  of  Ihe  bwly,  baa  in  nrnnkeyB  KM  warn  olhtr 
piiinml.4,  the  siiijfiilur  dlcct  of  prirxtudnK  a  vocal  utteraDc«  in  tht  (bran  of  ■ 
cry  or  b&rk.  HuL  ne  oaniiot  timke  tnuch  u&e  of  tbeee  rcsulu  tor  tb«  par 
pots  of  ilniwitj);  condusiiiiw  bs  lo  nhat  aliare  ibme  bodia  Utko  in  tbr  wliok 
work  of  iht-  hrnrii.  In  (be  fn>x,  ibe  oiilic  lobts  correspond  to  tbe  two  pair 
of  oorponi  iiiitiilri^uiiim  l<)i;k.'thi-r  ;  una  iho  cry  jufit  mentioned  majr  perfatfi 
be  put  side  l>y  fide  with  thv  fuel  tliat  in  tbe  fro^  tbe  optic  iob»  Memi* 
turaioh  a  mecbanisni  for  cniukin^ ;  nhen  tbe  optic  lobes  sr«  deelroj«iI,  tbt 
n-flex  viouking  mrutioncd  in  ^  6^il  in  done  away  witb.  Tbe  probable  cowmc- 
tioD  of  tbe  piwlcrior  citrjNTu  (luudrigeniinn  nith  bearing  b  alao  intereitiDg  b 
tbi*  cnuui-ctirin;  btil  we  have  no  MtiiKluciury  evidence  of  iiajr  special  \M 
bctnccn  tbu  liodicK  in  ijurrtion  and  cilhrr  tlie  coniral  urea  fur  pbonMuaur 
the  viieal  mfdniniARi  in  general ;  tbe  ovcurreiiuc  of  tbe  cry  remattu  so  turn 
i»(ilntLil  fact. 

In  frogm  in  which  the  cerebellum  is  very  (mall,  iho  nptie  lnbn>  seota  to  Is 
jiarlicLiinrly  cnnccnicd  in  the  coonlinniion  of  movcnwrnn.  When  tbebiib 
ts  rrmoviil  by  nimns  of  a  section  behind  the  optic  lobes  thv  nnimnl  loss  tltf 
|>uwer  of  balancing  ilsclf  ($U^U),  which  it  ixwmwcm  when  tbe  scctinn  psiw 
m  front  of  the  oplic  lobes ;  and  injury  to  the  optic  lobes  produce*  innWiHitn- 
tion  of  movement  und  iil\on  "  forced  movcnH-nl*."  It  biis  Ix-en  luaiiiuiaal 
ibnt  ibe  Iocs  of  coordinalion  is  in  these  cafes  doc  to  remorai  of  or  injarjli 
the  central  gray  molter  in  llie  walls  of  ihc  third  veDiricle,  and  oat  ts 
niertr  removal  of  or  injury  to  the  oftic  lobes ;  but  the  irhole  evideocs  p** 
to  abuw  that  in  the  fro;-  and  in  tbe  bird  the  opiio  lobea  d»  play  a  pnri  ia  ibi 
co{ir«)i nation  of  movement,  though  leniuus  of  ilie  centml  ^ray  matter  aroni 
the  third  ventricle,  or  indeed  of  the  thalamus  or  other  parta  of  the  i«p 
lueiitum,  may  give  rine  to  loss  of  coOnlinution  or  to  "  forced  moveiocnti.'' 

In  ilie  mammal  removal  of  or  injury  to  tbe  posterior  corfwra  i]u>dii- 
j^miDa  doeB  not  cau>c  biindnew,  but  may,  like  a  lesion  of  tbv  nuicrior  pai>. 
give  rise  to  loiut  of  ooOnlinulionor  to  foroeil  moveaients;  the  edwot,  bowcnr. 
14  in  niont  inKiuucai  very  tcmponiry.  The  voiiueotioD  of  tfa*  anteriot  mil 
with  virion  suggests  a  clue  n>  to  how  this  pair  tnkfi*  part  In  cofirdtnUM*: 
but  us  to  huw  the  posterior  pair  could  inlvrvcnein  the  mutter  wo  havobanfif 
»o  much  ns  a  hint;  fur,  even  if  viif  nilmii  u  eonneciion  between  ibcot  ni 
the  senn:  of  hearing,  and,  rem<-mbiTitig  ihiit  a  loud  souud  will  on«n  mm% 
])e»»ii  to  rtvl,  further  mlmit  that  pun-ly  auditory  iinptilKV,  lu  diattnci  tmrn 
what  wc  have  called  am|>ullar  impulM^,  may  lake  ]mn  in  the  ^Dcrale» 
ordination  of  bodily  movements  and  in  the  maintcnauoc  of  •qutlibriunmi 
tbcy  certainly  do  tn  the  ei>ecinl  coordination  of  laryngeal  move nients,  (till 
neare  not  miicb  nearer  un  undcntttnding  uf  tbe  matter.  Wo  mayaiMtyi 
wcliiiD  of  the  lateral  lilkt,  which  appears  as  a  consfncuous  tiv  beiW«M  Us 
|Hnteri<>r  corpora  qiiudrigeniina  and  the  parts  of  llie  nervous  systom  btbM 
them,  does  not  appear  lu  have  any  markeil  cHect  in  producing  inoo>>n]iliall|L 

Id  fine,  beyond  tlie  broad  facts  on  which  wo  dicell  in  a  previonsseed^H 
nanicly,  that  we  muiuiain  our  equilibrium  and  carry  out  complex  ridvcmmV 
involving  otlen  several  pnrlH  of  our  bu<)y,  lhroij);h  what  He  call  eodrdinatioa. 
that  allercnt  impubes  supply  important  faolors  of  this  coord i ua tiuo,  aoJ 
thai  the  ccrcbcllniu.  tbruiif^h  the  Tcsiiliiilar  nervee  in  part  at  all  ovtni*. 
together  with  other  portions  of  tbe  middle  brain,  ar«  in  some  itny  it*  cbNf 
instrumcois,  we  as  yel  know  very  little.  We  have  certainly  uu  adniualt 
kiiowled^  OS  to  bow  eitlter  pair  of  corpora  <iuadrigeminu  axooUy  ini 


I 


I 


ASPECTS    OP   THE    FUKCTIOlfS   OF    THE    BRAIX. 

in  ihc  mailer,  or,  indeed,  as  lo  what  other  pirU  thef  play  in  the  eeneral 
work  of  the  bntin. 

With  regard  to  other  Imcu  of  Gbres  or  areu  of  f-mr  mntior  we  have 
nothiliK  to  my,  except  at  rv^Hnli*  tUnee  which  arv  mora  or  lodi  iinmediately 
oMtDected  uilh  eertjuo  of  liie  criuiiid  tiervM.  >ucli  fur  InslaDoe  as  the  nurvea 
for  moTenionUof  tbecye»,Hn<l  tlieieit  will  be  beat  to  coosider  vrbea  we  have 
to  deal  with  the  oervat  tbemi<i>lv«*L 

§690.  Bt«i<lei  the  »oinatic  ftinctionf  which  In  prerioua  dIacuMlnus  nr« 
have  chi<-Ay  had  in  view,  thu  liniiii  lu  a  wboli-  undoubtedly  carriee  out 
aplandinic  functioDH ;  coiicernioi;  lliMo,  liowuver.  vin  miut  be  very  brief. 

Of  the  rttpiralory  and  vuoiDotor  fnuctioiu  of  tbc  bulb  we  have  already 
tmtrd  (d  (heir  ap)ir»priulr  place*,  and  we.  have  referKi)  ($53l{)  to  the 
experiinrntnl  evtdriici^  iliiit  n  ln<ii>R  of  ihu  ciirpiiH  striatuni,  or  of  the  front 
part  uf  tUi!  oplic  tlinlamtix  luui  n  minnrknbli;  infliivuce  un  tbii  development 
fif  heat  in  tbe  body,  Wu  hiivv  furllmr  »vv.n  thiil  thi-  higher  pnrU  of  the 
brain,  acllng  through  the  bulb,  cxprci*!-  powerful  iii(1iii--nci!<  on  nvpinilion,  I 
■la  lli«  vaAomotor  syntem,  nn  I  on  iho  bciil  of  tbc  hcrtrl.  Duly  f):pcnL-uce 
alT-trd!  abundant  in«t«ncc«iif  nclinn*  ench  m  those,  iv  well  luof  the  inllurnce 
of  the  brain  on  other  organic  fiinclions.  We  can  brinj;  our  will  to  bi-ar  on 
tbe  OKebaniun  of  micluritlon  (§431)  which  i*  almost  wbnlly,  nn<t  on  the 
meobaDKin  of  defec«liun  (S  271!)  which  is  lar;gcly  sjilnndinii-  in  nature. 
Tticae  movements,  however,  nn>  nol  skilled  niovcmiintx  :  nml  iw  wu  cxplntunt 
ill  dealing;  witli  them,  the  aciioo  of  the  brain  a.*  rcgnrils  them  ancois  liiiiit«<l 
lo  uii;;nteniiH;r  or  inhibilinj;  the  activitv  of  spiiiid  centre*.  Wcshould,  thera> 
fore,  hardly  expect  them  to  be  s|>ecially  represented  in  the  cortic-il  motor 
r^:M>n.  But  emutioua  have  a  mii(.'h  wider  and  more  powerful  tnHuonoe  over  | 
the  Rphuiclinic  functions  tlian  has  ttie  will,  and  hare  tbe  poirer  of  affecting 
thu  Work  of  certain  orjtanj,  fur  instance  the  heart  and  secreUng  glands,  which  ' 
the  will  is  umihic  to  toudi.  And  since  ive  have  ever>'  resson  to  believe  that 
the  corlex  is  chuxrly  aMor:iate<)  with  the  emotions,  we  mav  naturally  infer 
that  elements  of  the  curtex  ■ii]i|)lr  a  link  it)  the  chain  thr»u;;h  which  an 
emolioB  intlucnm  this  or  that  splanchnic  activity;  we  may,  accorilinttty, 
extieet  to  find  that  stimulation  of  some  pnrt  or  ■■lUer  of  the  cortex  produces 
»plaiichnic  ctfecis.  The  riwiilts  of  cxpcrinu'nlal  inveittgiitien.  however,  are  | 
Itoih  scanty  and  difconlnnt ;  but  the  greater  weight  should  {>erbai)s  be 
attached  to  the  positive  rcnults.  Thus,  some  obwrrvom  find  that  atimulation 
of  tbe  corlex,  the  locality  being  in  the  dut  sonwr  part  of  the  siiimoiil  jtyras,  , 
priMlucen  movements  of  the  bladder  ;  and  tncy  trace  the  path  of  thin  iullueuce 
ibmufch  tbe  front  rart  of  the  thalamus  and  the  tcgmcntam  to  the  bulb  and 
aa  In  tbe  curd,  exuludin;;  the  oeretMllum,  whiih  other  observent  believoil  to 
be  conceme«l  in  the  mailer.  Some  observers  a»iH  find  that  stimulation  of 
the  («irtex  produces  a  tlow  of  "  chorda  saliva,'  while  others  maintain  that 
ibe  Mcreiiun,  when  it  does  occur,  is  an  indirect  and  not  a  direct  efloot  of  tlie 
cortical  stimulation  ;  and  it  may  be  remarked  that  the  oortical  area,  which 
iactainml  to  be  a  "  salivalt>m  area."  IvIuk  in  the  dnj;  on  Iho  coavolntions 
iloraal  to  and  in  front  of  the  Sylvian  Wure.  is  not  either  the  area  eonoecied 
with  the  iiscial  nerve,  or  that  allotted  lo  lanie  or  smell. 

i^milnrly,  xtimulation  of  paru  of  tbe  eortex  has  in  the  hands  of  various 
obwtvcrs  kxl  to  movemcntB  or  to  arreat  of  movements  of  the  inte«tiRa«,  to 
cfaaiuea  in  the  h«*t  of  tin-  Iwart.  and  to  various  vasomotor  and  other  eflecla ; 
hut  It  will  not  be  profiiabh?  to  enter  into  an^  further  detuiU.  Wo  ntajr. 
however,  add  the  remark  that  wliea  the  oorticul  mutur  area  for  a  limb  \i 
reniove'l,  or  sutTcnt  a  Iwion.  tbc  temporary  paralysis  which  is  thereby 
dosed  is  acompanicil  by  a  ri*c  '>f  lctn|Wrature  in  the  limb :  Mf  may  be  at 
very  great  indeed  ;  in  the  moukvy  tor  {mtanoe,  tbe  band  or  fool  on 


B70 


TBE   BBAIN. 


Ihr  para1yz«<)  oitlc  may  be  a*  inucli  as  10"  C.  higher  than  (hut  nf  ibe  i 


»iiio.    The  cfTfi't 


nnlv  <lt 


.Ily 


riworoutor  raralyviv,  l>u(.  osfMTial 
fiilering  that  ibr  niii»cli-(  of  the  limb  nrc  rclatircly  rjuitnivtil  mikI  *u  pro- 
ducing ivM  lioiit  ihiiii  uKiml,  ejiniiot  Itf  tiuti  to  thai  ilonc  The  nrnmrhablt 
rc-eiill  niny  lie  luki-ii  ii«  "till  fiitthcr  iilu#iriuint!  tint  cwnplcxily  of  thv  prw 
ccwn  Coiini.'d<-il  v>  itb  Iho  cgnicnl  motor  nn-n  ;  lh«  nrrsi  is  in  t>i)iii«  way  umt- 
Gtntcd  with  ih<-  vn^culnr  nrriiii^omcnbi  mid  outHtiun  of  (he  initM-lea  «iik 
who*o  Diovcnitnl*  il  in  CDncrructl. 

S  691.  Then:  irmntn  yet  a  few  nords  to  tw  Mid  about  the  trortcx.  Wi 
rrgurd,  and  JLiHtly  so,  ihi;  Hp)>niaucotin  intriiigic  iwlivitr  of  the  brain  an  ihr 
nio»t  tlriliin);  f^^iilurc  of  its  life  'T\w  nenrest  npjiroac})  to  it  nhiiih  are  SnJ 
ebewbero  in  the  body,  is  perhaps  the  rhylhniii-  Ireal  of  ibc  heart.  Tlir 
analogy  between  the  "regular  aiilomationi"  of  the  oiie,  and  the  "  irrwalar 
autonialisRi '' of  the  othifr  ia  a  Elrikin^  one;  and  iiideot  our  kno»lt(^«f 
the  relalively  ttimple  sponlaDeiLy  of  llie  henri  haa  probably  iDdueiired  to  ■ 
larse  e.iteni  our  conceplions  of  ihe  complex  sjxHilaDeity  of  the  bnuu.  b 
the  heart  the  rhyihniic  didclmrga  of  energy  a  chielly  deternuiied  by  in- 
trinuo  cheniicnl  clianges,  hy  the  luciabiiliam  of  tbe  cnnlioc-  MilwiAnoe;  ilw 
influence  of  exIerDal  circunutHiicea.  ajwri  fmni  tboae  which  pnivida  aa 
adequate  supply  of  pro|icr  blond,  \»  wholly  subsidiary  aiu)  aervm  only  M 
roJse  or  to  lower  tbe  intrinaic  d>un;;e«  from  time  to  time,  a*  nccaiiroo  ma 
demand.  And  ihe  analogy  of  the  heart  btu  pvrhapa  led  us  In  cxwga«Mt 
the  part  played  in  the  bruin  by  itie  like  intrinKic  cheinicAl  tiwiamiMh 
(We  are  liere,  nf  cnunw,  viewing  the  at-iion  of  the  brain  from  iba  Mir 
ataDdpiiiiit  iidnii.i»i1ilc  in  llirae  pag<'>,  the  iiun:ly  phytii>lo«ical  oih>  ;  bat  wea 
a  mono  of  trt-iUuK'ul  iim-»  not  prejudge  olli<-r  puinls  of  view.)  Souk  wrikn 
use  czpreMionii  wliich  i^ceRi  to  implv  llin  coiiccplioD  that  tbe  iMrvoui 
diaoges  forming  the  btisis  of  tbe  perchi(.-tt]  and  other  procffiaes  of  llie  brato 
lire  chicHy  the  direct  outcome  of  the  cbcraicnl  mclaboliaiii  of  iho  gray 
mutter  and  e^pecinlly  of  the  nerve  ccIIh.  They  speak  of  "  the  diacharga  m 
energy"  from  these  c«IU  in  the  taiue  wny  that  we  can  speak  of  ibe  dil- 
charge  of  energy  from  a  cardiac  fibre.  But,  to  say  nolhiitg  of  ibe  luw  rait 
of  oervotia  metabolism  as  nienaurecl  in  terms  of  chemical  eitergy.  we  bar* 
no  exnerimentni  or  other  evidence  uf  nervous  atibstauce  in  any  part  of  th* 
body  neiiiji.  like  the  cunliao  substance,  the  seat  of  an  important  metabuli» 
carried  ou  irrei|jei:tive  of  influences  other  than  purely  nulritive  uuea.  la 
ibe  case  of  nerve-cells  interpolated  along  nerves  cou)|>u4ed  uf  fibru*  of  iht 
Mime  kind,  as  in  the  sporadic  ganglia,  nil  tbe  instances  where  tlw  nfrrc-tvUt 
were  supposed  to  initiate  active  jiriK-t&ies  have,  ou  exaiuin.itioH,  brokea 
donu ;  an  wu  have  seen,  the  ganglia  of  tbe  heart  do  not  aupply  tiia  moving 
cauite  uf  the  heart  Iteiit.  It  i!>  only  in  the  wiitral  nerroiu  mt«in  whsi? 
iiGrvei'^IU.  a>  |iart  of  |;ray  niniter,  are  found  at  the  meeting  of  utm-^r» 
of  ditrcreni  kinds,  that  we  have  any  evidi^nce  uf  "  discharge  of  antrgy* 
fruin  the  cl-Us- 

Aa  wtr  |H>inteil  nut  (SAd^t)  in  speaking  of  tlie  spinal  cord,  ibe  ilischargt 
of  efferent  impiiU««  fn>m  the  central  iivrvoon  AVEttvm.  though  it  uodouM- 
tdly  must  have  a  u^rtain  chrmicAl  bn»i*,  nniiiely,  tin;  metabolism  of  th« 
ner\'ou.i  subntaiicc.  in,  in  ilic  fiwt  lin",  dei>pndwit  <>a  the  itilvrnt  of  alfenal 
impulses.  Hut  this,  if  true  of  the  i>pinal  cord,  is  i>till  m<irv  true  of  ibt 
hrsin,  wbiuh  receivt«  or  may  receive  not  only  ell  the  impulses  which  reach 
It  through  the  cor^l.  but  cspecinliy  [Kitcnt  ond  varied  impulses  iltnctlt 
through  the  cranial  nerves.  All  lifo  long  tbs  Dcvcr-ncirang  ohangea  of  tht 
external  world  continually  break  us  wavca  on  the  peripheral  eodings  i>f  Uis 
afferent  nerves,  all  life  long  nervous  impulses,  iion-  more  now  fewer,  are  o«- 
liuunily  sweeping  inward  toward  the  centre ;  and  the  nervous  iuetab<'j!Uiii. 


OTHSB   ASrSCTS    07   TBI  FUNCTIOXS  OF  TUB   BRAIN,     till 


P 


I 


which  ill  the  bndi  of  Dervou*  ftctloD,  tnuBt  I>e  at  ]«aat  u  t&rjtoly  depeDilent  i^n 
tb«w  iiiDii«aca  from  irllhout,  an  on  the  lueru  «beiiiioaI  iiii|)]ilj'  runmhiil  by 
the  IiIohI. 

We  hiive  «Icvel<>|ieil  thii  point  becauM  uf  the  iuflueoce  it  uusl  have  on 
our  coiMWpliMU  of  the  (ihyritilneiml  |)rucV!Wi.ii  tttkiD^  iiIhcc  Id  the  coflex. 
If  we  tMKCpt  Htv  vivM  jiut  luid  (liiwii,  wv  miint  n-'jfiiril  the  *u|iereRiiiii.'Til 
KClivitj  of  the  corlox  mid  the  churiii.'tcr.''  uf  the  proi^vMoa  lukiiij^  place  in  it 
«■  clui"  uui  lui  much  to  itic  iplriiiKic  clK'niii-nl  iiiiLiire  nf  iht'  iiitvduh  xub'litiK'O 
n  hi<'h  i*  built  up  into  th<^  corlicnl  gray  inalter  hh  to  the  t'lit't  that  iniputx^ 
sre  ctinlinuallj'  itmmiug  into  it  from  «ll  pint*  of  ihu  hmly,  ihnt  alm><^E  all 
itiflucnco  bnmgt  to  U^ar  on  ihe  body  mnkr  ihi-miM-lvi*  firlt  hy  it.  To  put 
the  tuntter  in  a  ImiIiI  vny  w«i  mity  itek  iho  qiientioii.  Whiit  would  Itappt-n  in 
lb«  cortex  if,  iU  urilinjirr  nutritive  dupiilv  rcraniiiin);  a»  hi-fore,  il  wen?  cut 
wlrifl  from  nffercnt  impulses  of  nil  kimU?  We  run  Inirdly  doubt  but  lliat 
vuliliiioml  ami  other  [Mychical  pn>e>«a'«  would  to»n  ootoc  to  a  atnndstill  and 
OonseiouMieM  rnnHh.  This  is,  iiidveil.  roughly  iiidienlcl  by  the  remnrlcuble 
CMC  of  a  patient,  whose  iilmott  only  eomuiuiiictilinn  with  the  estcmal  nurld 
wu  by  means  of  one  eye,  he  beiog  b'iii<l  of  the  other  eyo,  deaf  of  both  nan, 
•ad  Mflering  from  seiiernl  niueethesin.  Whenever  the  sound  eye  waa  cloMd, 
)w  mat  to  sleep.  It  is  further  iiidireetly  itlustimted  hy  che  fonowiD;^  ex- 
parimefltal  reault.  Wo  have  seen  (!;(Sd.^)  that  a  vertical  inclsiun  carried 
tltroueh  the  depth  of  the  },'ruy  matter  around  nn  area  does  not  prevent 
■tioiulation  of  toe  surfaee  of  the  area  pnNliicing  the  usual  movemeota. 
Bat  after  aucb  an  iaeiaion  the  animal  suHVrit  s  parnlysit  of  the  Oioveiuoilla 
ooonecied  with  the  area,  lik«  that  leaultiu^  fr>iiu  the  remural  of  the  gray 
mftlter  of  the  area :  aud  the  u|>«raii<>n  i«  said  to  be  fulliiw(>d  hy  d>>>^uera- 
live  changn  in  the  area,  and  dei;eueraiion  of  the  pyrainiilAl  libKtt  «tar:iii^ 
from  iL  Home  of  thia  eOcvl  may  lie  due  to  nulrilive  chan);i^  brought  about 
by  iniury  to  th«  pia  mat«r  and  iliviriinn  of  bluodres«elN ;  l)iit  it  cknniil  be 
wholly  accountnl  for  in  this  way;  it  ap|>ear*  aa  if  the  life  of  the  area  il 
euriailed  whim  ila  nervous  tin*  arc  broken. 

We  may  conclude  then  that  we  nrv  not  juslilicd  in  s|X!nki»j{  of  con- 
•ciouancM  or  volition,  or  other  iMychical  prucuatui,  even  admitting  mat  tlieM 
fail  when  the  curtei  \i  removc<l,  as  being  functioiu  of  the  cortex  in  th«  saute 
■■y  that  we  speak  of  the  fuiictionii  of  other  organ* :  they  arc  mtUcr  func- 
UoM  of  the  ooanecliniis  of  the  cortex  with  the  other  parta  of  the  coniral 
nervous  syatera. 

We  altould  add  that  tliey  are  also  functions  of  the  oonucetions  of  the 
several  parts  of  the  cortex  with  each  other,  All  our  knowledge  goes  to 
allow  ihat  psychical  pruceMea  are  dejteniient  on,  or  are  in  eonie  way  aMo- 
Otated  with  the  cortex;  but  whatever  c  I  nasi  li  cation  of  psychical  fuuctious 
w*  adopt,  w«  are  wholly  unable  to  make  out  any  localiution  of  functioni, 
such  aa  we  can  make  out  for  in  •vemenla.  visual  len^ations  and  the  like. 
Even  taking  the  broad  aud  elemeuiary  division  into  "  the  emotions "  and 
"  the  intellect,"  ne  canuut  uitiafactorily  allot  eitlier  diviuoa  to  any  pariiuu- 
lar  |>art  of  the  heoiiaphere.  In  d<i^.  removal  of  [wrticular  part*  of  tli« 
bemiiipiiere*  has  iiKlced  been  i>b«erred  to  cbati^ce  the  character  of  the  ani- 
mal, cuuvcrtiiig  for  inilaiK'c  a  vicious,  moriwe  dog  into  a  mild  and  iuiA'en- 
aive  one;  aiul  removal  of  the  front  part*  of  the  beiuiipbcn;  neenui  to  have 
frei|ucutly  a  marked  ctH-ct  in  reoderinx  the  animal  mure  improatioiutble  artd 
excitable;  he  Wcoaiut  much  more  deiaoaitnitive  and  "gu»hinK"  in  his 
behavior  than  Iwforv.  But  ihcM  are  mere  hinbt,  and  the  clinical  hiatnriea 
of  dbacasc  in  man  do  not  enable  lU  to  snr  much  more.  Such  knowleilge  aa 
we  (to  poMoa  latlwr  tends  to  ahuw  that  tnc  piycbical  procwna  in  proportion 
as  they  beoooN  more  complex  involve  a  greolar  Buntwr  of  nwvoua  tactora, 


THE   BRAiy. 


and,  iherefbre,  hare  for  tbdr  miiterinl  btuls  a  frreat«r  wultli  nf  ucrvoin  arat 
nr  in  other  wonb  their  lucnliuilidu  bvoomM  laM  ileTiniu.  Tbia  while  ws 
may  localiie  tlic  iK^'inniuj^  of  h  pfycliical  procea*,  a  rinual  Knntioa  (ur 
imiance,  aod  ont;  of  ibi  U-rminal  nuia  auch  a*  the  inue  of  Impubea  sinntg 
the  |iyramitUI  tract,  we  cnniioi  put  our  finger  »R  the  Mat  of  the  iol«riiM- 
<lint«  tmii»actiou)i.  Tht*e.  Mvn  in  the  HirnpWl  procnM*  inu«t  b«  o>i(n|i)ei. 
aixl  mii«l  involve  many  rndiirs.  Our  timnltvl  conceptions  of  the  external 
wnrli)  are  bumvl  nii  u  cuinbinntion  of  vtfiinl  trnmtiinx  ami  tn^lile  aeiwatinQi. 
It  being  granted  that  the  vinual  nunntion,  in  onti  phase  of  iu  developQWt, 
i«  conneotei]  with  <H-nnin  ctuuiKcs  in  some  spot  of  tti«  ocdpjtal  cort«s.  thi<n 
mtiat  be  mmc  tif  iNMnfcn  this  nod  the  corrMponding  nvrmtM  aeat  of  iW 
tMtlle  aemalioD  wherever  that  may  W,  and  further  tU»  between  theae  >«4 
nther  pans  of  the  corU^x.  Hence,  m  we  said,  the  peychical  pnniM  b  a 
fimrllon  of  rnnncelions. 

Many  nf  i\HfV.  iiv*  arc  moft  pmhalOy  fiimishet)  by  the  anoriation  fibni 
paMine  from  one  part  of  the  oorC«x  U>  a  nei);>il)»ring  purl.  We  muat  alM 
proluihly  admit  that  impulses  or  to  nsv  a  more  general  word,  prooewn.  may 
travel  laterally  along  the  tangle  of  the  corlieal  gray  mnlter,  for  ihi*.  lin 
the  gray  mnttcr  of  the  spinal  oord,  seems  to  form  a  phyaiologicAl  conlinoily, 
DO  more  broken  by  the  l)<eum  than  is  the  cord  by  ita  segmental  arniitc*> 
meot ;  and  we  know  nothing  a>  to  the  limits  whieh  luUBt  be  plae«d  on  il» 
distaDoe  to  whieh  puch  prooeases  may  travel  from  their  focus  of  origiH, 
Further,  eeeiug  how  completely  In  the  dark  we  are  as  to  the  reason  why  M 
possess  two  hemisphere,  and  eopeeiaUy  seeing  that,  as  shown  by  speech,  tte 
whole  of  ench  hemisphere  h  out  identical  in  action  with  the  whole  nf  lb 
other,  we  may  perhaps  suppose  that  the  fibn»  of  the  corpus  catloetini,  wiAk 
form  BO  large  a  part  of  the  central  white  matter  ol'  the  bemisphere^  ban 
other  duties  than  that  of  merely  keeping  the  poinlii  of  one  benil*phei«b 
touch  with  the  et>rrMii»Tiiltng  poinln  of  tho  other  hemiupberi'.  Ritt,  wbca 
we  hnvir  niiule  rvery  allownncir  for  all  tho*e  direct  int<irc»rtiiiil  coonecliuafc 
wc  arc  drivt'n  Id  llx!  cimc1u.->iiin  that  the  in<lirc('t  tie*  betwvcn  one  part  (tf 
the  cortex  and  ani>lhi-r  thmugh  the  lower  parts  of  the  brain  an)  of  no  Isi^ 
pcrhapa  of  grentrr  importJiiici^  Thi*,  indn-it,  ii>  shown  by  the  n-ln:i<iat  t4 
the  motor  region.  We  hnve  already  ur^d,  that  even  as  re^rds  the  nivie 
carrying  out  of  a  skilloil  movemt^nt  (and  we  may  add  whether  that  b^^  rnl- 
untary  or  iiiroliintnrr  in  the  orJinnr}'  eommon  line  of  the  words)  tW  n>ni*< 
region  must  have  olhcr  lies  with  the  (lart  moved  than  merely  ibo  rfli'fMa 
tie  of  the  pyramidnl  tibres;  it  muxt  have  scntory  alTercnt  ties,  and  the 
course  of  these,  including  even  perhaps  those  which  belong  to  the  mitseular 
aense,  we  mav  regard  as  an  indirect  Mie  along  the  spinal  cord  and  middle 
parts  of  the  brain,  though  the  details  at*  as  yet  onknowa  to  us.  It  aiuil, 
moreov-er,  as  we  have  also  seen,  have  ties,  at  least  in  many  cams,  with  parts 
other  than  the  part  moved,  for  instance  with  the  geuersl  coonlioaliM 
maehiiiery.  And  the  ea>e  with  which  some,  not  very  ohviniie.  chani;e.  wiu 
|>ermit  the  siimidation  of  a  limited  iriolor  area  to  ^tart  epilcptifiriti  (.■oiirul- 
mous.  shows  how  ninoy  and  close  are  the  ties  in  another  direction-  Further, 
when  we  go  beyond  the  final  phases  of  the  process  in  the  motor  cortex,  to 
tbiMe  which  precede  the  issue  of  the  eSttreuL  iniputsea,  we  find  the  ties  mal- 
tiplyiiig.  For  instance,  since  our  mnvemenis  an*  so  largely  guideil  by  visual 
BeoaatioDft,  there  mu»t  he  tiea  between  the  mul^tr  cortex  and  (he  central 
visual  ap[>anitii«,  it  may  he  of  the  occipital  cortex,  but  it  may  also  be  of 
the  lower  rinual  centn«.  An  we  ituialeil.  the  motor  are«  is  only  a  link  in  a 
complex  chain;  and  what  we  can  see.  dimly  though  It  be,  iu  ref«rvui.'«  lo 
tlic  oortical  motor  prooeves,  probably  holds  good  for  those  other  n>Tlk«l 
piMCMM  as  well,  of  vhose  nervous  g«nQ»is  we  know  at  jtrescut  nothlag. 


THK   TtllE   TAKEN    UP    RV   CEREBRAL  0PEBAT10N8.     87S 


I 

I 


I 


I 


ertn  ibe  higher  iwyebtcal  ereoto  rannot  truly  be  tpoken  of  "»  fimo- 
of  the  oori«x,  ntuiiiig  that  they  are  'irnpiy  tlio  outoome  of  nolcculRr 
diugea  in  the  OMtio*!  gray  matter ;  thoy  are  r&lhor  to  be  it^rded  a»  the 
onteoae  of  eomplex  pncMMa  in  which  the  parts  of  the  brnia  belnw  lh« 
o«niM  pl«y  a  part  no  leaa  iraportaat  thaa  that  of  ih*  cnriex  it«e1f.  If  90, 
the  fibraa  pMsio^  down  from  the  eurbex  to  tlte  mi'ldt?  brain  hare  fbactJoiiB 
by  wliioh  Ibey  take  part  even  in  our  paydiical  life.  fuDctiona  for  which 
neither  the  words  motor  or  wnaory  are  filtiog. 


0»   THK  TtMK  TAKKX   I'P    KY    CkRKRRAI.  OpEBATlOirs. 

§  698.  We  have  nlrradv  rttn  ($  ASS)  ihnt  •  cmi*iH«rnb1p  liaie  ia  Inkcn  up 
ID  n  purely  rv6«x  act,  nach  an  thiit  nf  wirikiiiif,  though  thi«  is  perluips  the 
moat  rapid  fnrmof  n-fl«x  nvivcnictit.  WhcJi  thr  movtMnODl  which  ifl  executed 
in  mimnae  to  n  ftimiilu*  invilvn  cerebral  npcrationit  a  «liH  lonfcer  time  ts 
needed  ;  and  th«  inlprvnl  hclween  the  npplii'niiiin  of  the  xlimulua  and  the 
rnmnH-iicemciit  of  ih*-  tnnoctilar  coiilmction  varin  according  to  the  natui?  of 
the  mental  labor  involved. 

The  Mniple*!  case  in  that  in  which  n  person  makea  a  msnal  immediately 
that  bi>  p^rreivi:^  n  ^tiniutiis— rj^.  ^r.,  cloeefl  or  opens  a  f^tVaniC  circuit  tite 
moRMtnt  that  he  feels  an  iDttnctinn-sbock  applied  to  ihe^kin,  or  (r«9  a  l!a*h 
of  light,  or  bears  a  Bound.  Ily  arrangements  similar  to  those  cmplnriHl  in 
Rieiuutini;  the  velocity  of  nervous  impulnee.  the  moment  of  the  application 
of  Ifar  Ktimuhia  and  the  moment  of  the  making  of  the  Hi^Dal  are  both  rveorded 
on  the  Mine  travelling  surliiee.  and  the  interval  between  them  is  carefidly 
nmearrd.  This  interval,  which  has  been  called  "  the  reaction  period  "  or 
"ntaeiion  time,"  may  be  divided  into  three  otagea:  1.  The  lime  during 
which  afltrent  impuiiM  are  generateit  in  the  iieriphcral  Muse  organs  and 
transmitted  along  the  iilfi^riMil  nervca  to  the  central  nervoun  nvvtem ;  thb 
may  he  ralle<l  the  "afTereiit  stagv."  2.  The  lime  during  ithioh,  through 
the  operations  of  the  central  nervous  systctn.  the  affiireni  imiMilio)  are  imn*- 
formed  into  efferent  inipu|jw»:  this  mnv  he  called  the  "central  atage.** 
3.  Tbe  tiiiiv  taken  tip  hy  ihv  [isaMgc  nt  the  elTi-rent  tnipulacw  along  iha 
aB^ot  nervni  uud  tbe  t  ran*  format  inn  of  the  nervoiu  impulMv  into  muiicular 
eoatractioiis ;  t)ii«  may  lie  called  the  "  cflV-rnit  Htage."  Tn  the  rflert-Dl  slaiire 
the  eveata  are  omiwnttivclr  iiimpli'.  and  though  not  ahaotutelv  e<in«tant,  do 
Dot  vary  largely ;  nc  an.-  aide  to  furni  a  fairly  tntitfnctorv  citininte  of  its 
duraiiitn,  and  m  of  the  i>hnrc  in  llu-  nhnlc  nmetion  period  which  may  be 
allottrd  to  iu  The  ovi'oIk  n[  Lhe  uflfri'nl  ftage  an?  much  more  comples.  and 
tbe  calimatea  of  ila  dumtion,  Ix-ing  arrived  nt  in  an  indirect  manner  nod 
chiefly  baaed  upon  cah^latJont  of  tbe  whole  reaction  time,  are  very  unoer- 
Uin.  Henoe  all  atieiuptii  to  estimate  the  length  of  the  "  central "  stage,  the 
"reduced  mnction  period,"  as  it  i*  sometioiM  called,  by  subtracting  the 
eScreot  and  aflrrenl  staifca,  must  be  rabject  to  mnch  error.  But  a  good  deal 
maybe  Iranird  by  otudying  the  variationa  under  diflereat  circoinsiaaoes  of 
tbe  reaction  iH-riml  lut  a  whole. 

Taking  lirat  of  all  tbn  cases  in  which  the  eventa  of  tbe  oeairal  stage  are 
aim  pic,  such  as  tbnse  where  the  xuhject  baa  merely  to  make  a  rignal  uyon 
fheling  a  MDsatian,  we  fin<l  ihiit  the  length  of  tbe  reaction  period  ■  depenatnt 
OD  iba  {nlMHity  of  the  stimulus,  being  shorter  with  tbe  stronger  stimultia. 
But  variations  in  the  strvngth  of  the  stiuiiilus.  npectally  in  tbe  nuei  of 
minimal  etinnuli,  have  a  much  more  striking  eKcct  iu  determining  the  ivr- 
tainlv  nf  the  reaction  than  in  nlfcctiug  the  laagth  of  llie  period.  Thus,  when 
the  signal  is  made  in  r»|Mn>e  to  some  visual  Beoutiou,  ujiou  seeing  an  elec- 


874 


TQg    BBAiy. 


trie  eimrk.  for  iiuUnoe,  If  tlic  apark  be  a  very  weak  one  the  subject  of  tke 
experiment  often  fails  lo  make  Ibe  lipial  iil  all,  tbougb  be  luay  nireljr  GUI  it 
(he  ajwrk  be  a  Ntron^  inie. 

Suniv  uf  tbe  in<ict  mnrkcil  viiriatioTw  in  tfae  lenirlh  of  rhe  re«c-tii>n  (leriad 
arc  (lettTiiiinnl  by  ibe  individualttv  or  thc<  nubjonL  Tliu«,  vritb  them* 
6ltmiilii«  ii{)(ili<'!'l  iimlt-r  thi'  luinir  circiiinnliinn*,  ihe  naoiiun  perimloTMi* 
|icr*rin  will  W  fonml  vrrv  ilifTcrr'nt  fma)  tbiil  iif  UDOllier. 

The  IciigOi  of  the  rcnclinn  pcrim)  vnriiv  u\mi  acv>r>liiiji  t<>  the  luiturc  lad 
(lisfKMiiti'in  or  thr  pcrifihrriil  ort^iim  »timtilittril.  In  i;i-ni>nil,  il  inny  be  mi4 
ihal  nitnm-ritip  srriKatiotis  priHliKiil  by  tbc  :>iimiibi«  of  aii  i-jivirii-  *hiui 
tLT>pli<''i  l'>  the  »ltin  i  the  »i^al,  for  inolnnoe,  bt-ing  mnilo  by  tbi-  rijiht  liuij 
when  tbp  »Unc'k  i»  iHt  by  ihu  k-ft  hnml)  nre  followcii  by  a  aborttT  reariinn 
prri<Hl  tbnii  nre  auditory  ernsnti'ins,  whik-  tbc  period  of  tbne  w  ia  tura 
»b'>rirT  than  thnt  of  visual  fLiitni  inng  pmrliict^it  br  luminous  ol^ect*:  on  ih* 
otbiT  band,  the  shortest  period  of  all  i«  aid  to  W  Ibat  of  vImikI  a^niialiaM 
produced  by  direct  electrical  stimultilion  of  the  retina.  Itoughly  Mimikinir, 
w«  may  say  thnt  the  Tcactiuii  |>eriod  is  for  cutaneous  srnntwns  oii»s*VMtii, 
Cir  hearing  one  sixth,  and  for  ei^hl  one-firth  of  n  SMond. 

Practice  materially  fihortene  the  reaction  pcrind  :  indeed,  after  Xnog  jvto- 
lieo,  makinff  (lie  aisiial.  nt  lir«t  a  distinct  effirl  of  the  vill,  takes  on  (he  char- 
acters of  a  reBei  act.  with  a  corresponding;! r  shortened  interval.  Ltially,  tt 
mar  add  that  in  the  name  individual  and  with  the  same  stimulus,  the  toaylli 
uf  tlie  period  will  varr  actrurdin);  to  circu nidloncea,  Mich  as  the  time  of  year, 
the  weatber,  and  the  like,  aii  well  as  accordiiif;  lo  the  condition  of  the  iacli- 
vtdual,  whether  fresh  or  fatigued,  fasting  or  replete,  having  taken  more«t 
leas  alcohol,  and  the  like. 

The  reaction  [leriiwl  of  vision  has  long  been  known  to  astronomen.  ll 
iniB  early  found  that  nheii  two  oWrvem  were  watching  the  ajipranowt^ 
the  ><am«  star  a  con^idrrnbU'  di-«-n^]>ancy  i'xinli-<l  l>etween  lh«ir  reapeOlTs 
Tviiction  pcHoilii.  and  th;ii.  (he  iiilf<'rcnc<-,  forming  the  basis  of  tht  KhoUM 
"  [leriHiiuil  CQuntion."  vnncd  from  tim«  lo  lime.  According  to  Ifaa  paftoml 
conditions  of  (he  observers. 

§693.  The  events  takini:  place  in  tbeecntmlatagcarcnf  courM,comp(tz, 
and  this  stage  mar  be  suhdividol  into  scvemi  sti^ca.  Without  attrnpiiif 
to  enter  into  psychological  ijocsiiong,  we  Diay  at  least  rMogtitw  oeriaia 
elementarr  distinctions.  The  adcrent  impuImM  started  by  the  stimtiliis,  wh•^ 
ever  be  their  nature,  when  tbey  r«ich  the  central  no rvmts  system  undtrgs 
changea.  and,  as  n-e  havcseen.  probably  compl«K  changes. bci>>rotb*)y  beoomt 
aeiisatiouH;  and  further  changes,  now  of  a  moredistintSy  pavehicat  rnaraelar. 
are  neceatar}-  liefore  the  mind  can  duly  approciale  the  cfMravU-rs  of  Uwa 
senaaiioiiB  and  act  acconlingty.  Then  come  the  psychical  procuasca  thnugb 
which  thetie  ajipreciulcd  sensations,  or  perceptions,  or  anpercepliona,  as  ihay 
an  eometimoa  called,  dclcrmino  an  act  of  volition.  LMtly,  there  are  thr 
executive  prooenee  ■>f  volitiou.  the  procemes  which,  payfillimi  to  bef  in  vitb. 
end  in  the  imie  of  cocirdinate  motor  impulsea,  or,  ia  other  words,  start  ili* 
dUtiiictlv  phvalolni-ical  prucesBCfl  of  the  efferent  Mage.  We  (tiay  ibiis  sptok 
of  tlu!  tictiL-  re<|tiiri'd  fur  the  [lerceplion  of  thestimulatJOD.  of  the  time  rei|uircd 
for  lb(?  action  of  the  will,  aud  of  the  time  required  for  iIk  oomplex  iiaydiical 
pmccKtM  which  link  tlieee  two  together.  Accepting  this  elementary  atialyii*. 
It  is  obvious  that  the  totjil  length  of  the  central  stage  may  be  variod  by  itif> 
ftircucM  in  the  length  of  each  of  tbeae  parts :  and  a  more  oompleto  anolystt 
would,  of  course.  o[>eu  the  way  for  further  ditttiuctions.  Heoee,  byattHlTbg 
ihe  variatiuiu  uf  the  whole  reaction  time  under  varying  forms  or  psycfuou 
arlivity,  we  may  form  lui  estimate  of  linic  taken  up  by  various  ]isychital 
processes. 


I 


I 


THE  TIMS  TACBK    UP  BT  CEBBBRAL  OrBRATIO.VB.      875 

Wr  mn;'  tnkc  as  nn  intlsnce  Ihe  nt<«  in  vhich  the  wibjpct  of  tho  i>xficri> 
menl  hni  to  Pi<rcu4>  iliKriniinntion.  ']'h«  mode  nf  making  tbo  Bignitl  Iwiitf; 
tlie  Hini«,  and  lh6  stimulus  bcinf;  of  ihe  Mine  order  id  each  trial — that  \«  to 
Mijr,  viMial,  or  culaneoira,  or  auditory.  i-K;.— nmi  getieral  rirciimstiinc« 
RnMBing  Ute  hidp,  two  diff«rent  tlimuli  are  employed,  and  the  subject  v 
required  to  mak^  a  ^i^finl  in  respoiwe  to  the  one  stimulus,  but  not  tn  the 
other;  (he  lubJeiM  has  li>  diteriininate  between  the  payebical  elfecti  of  the 
two  stimuli.  Suppose,  r»r  example,  the  flltmulua  i>  the  sound  of  a  spokeo  or 
sunt;  vowel,  and  the  subjecl  is  required  lu  make  a  siKual  wlieo  a  is  epokefl  or 
ranii.  but  imI  uheii  o  is  b|)oken  or  sung.  If  lli«  subfeot's  whole  reaction 
perioa)  l»e  deleriniiiet)  (1)  in  tlve  usual  ttav,  with  riihLT  a  or«s|>oken  (and 
tbn  result  will  be  ftiund  uul  lo  differ  miit^rially  nhrthcr  n  ur  o  be  u»ed>,  the 
■vfajed  knowing  that  imlr  <i  «r  o»It  o  will  be  g^Mik^n,  and  then  be  determined 
ajliiin  (2)  when  he  has  ta  dlscriniinalc  in  order  tlitil  he  mnr  make  the  sixnal 
whvn  II  is  spoken,  hut  not  nhrn  o  \»  KiHikrn.  bi^  not  knowing  which  is  about 
to  bo  spoken.  th«  uhnle  miclinn  period  wilt  1h-  found  l»  )h-  diKlimaly  louiter 
la  the  scc«ud  cn-ie.  The  exitt-rimrnt  mav  br  variiil  by  makingimMif  iill  the 
vowel  nunds  Inkcn  irreiciilarlv  m  lh«  otimulu*.  the  iiihjcct  mpondintr  by  a 
•icaal  to  one  only,  an  urrangtsl  lirfnn'hniid,  And.  of  cuunM.  other  orders  of 
Mimulutt  mar  be  iiicd,  either  vtfual.  ihc  [litEnal  hf  ing  miwte  wlii^n  a  nnl  light 
is  sbi'wn  but  not  when  other  t'olorx  ur«  ahown,  ur  tactile,  tin' nignnl  Wing 
made  when  one  part  of  thu  bo<ly  is  touched  but  nut  when  other  pitrts  ars 
tourhol.  nnd  the  like. 

In  such  cx|N.-riinent4>  where  the  eubji-cl  has  (o  disttnjruiBh,  to  discriminate 
ItrtwfrD  two  or  mora  cvcdis.  th«  prtflnnmlion  of  the  reaction  period  la 
obviously  due  to  Iht  lonMr  lime  required  fi>r  the  psychical  procMWH  takiag 
plain  (luring  what  w«  have  called  the  orotral  slngv.  In  the  two  cows,  one 
vtthout  ana  lh«  other  wiib  discrimination,  not  only  are  the  aflercnt  nnd 
eflerent  oiaKes  the  nme  in  br>lh.  but  we  have  no  reason  lo  luppiue  (hat  in  the 
rentrnl  stage  is  there  any  diflerence  b^inecn  the  two  c»»e»  as  lo  (he  time 
taken  up  by  the  transformation  of  simplo  feimary  impulsca  into  perceptions, 
or  as  to  that  taken  up  by  the  will  in  giiining  accns  lo  the  motor  spparatiM 
nnd  HO  staniiig  the  processes  of  the  tlUn-iit  stage;  the  delay  takea  place  in 
the  [ciyiliinil  procesBea  interrening  betneen  th«o  two  piiri*.  and  the  amount 
nf  delay  it  the  meaHure  of  the  time  necileil  for  the  pric™««  invntved  in  the 
discrimination.  Thiit  "  diicHiniuatiim  jicrioi] "  lim  l>><cn  fouitd  to  ditler  in 
tbe  same  individiml  aci^ordirig' to  the  wnsn lion  emptoyetl,  viiual,  nuditury, 
etc,  and  accnnling  to  thi-  kimi  of  dillervucc  in  tbeamntiot)  which  hoi  to  be 
dii>criminal«l.  for  iniijincr  in  viiunl  scn»ntioiis  between  oilors  or  butireca 
ob;re(#  in  ililh'ri'nl  narls  of  the  tield  of  virion.  In  n  tniric*  of  oWrvntiona 
made  in  this  way.  tnc  discrimimition  periixl.  i.  p..  the  prvilongntion  of  the 
•implc  reaction  jicriod  due  to  having  to  discriminate,  was  found  to  range 
from  0  01 1  vcomd  U>  O.iWi  svcoiid. 

Another  irries  of  obtrrvat ions  tnny  l)o  made  in  the  fiillnwing  way:  Tlw 
signal  being  one  mode  with  Iho  hand,  the  simplo  reaction  period  tnr  n 
stimulus  is  uclermiitcl  with  the  signal  given  by  the  right  hand.  Two  kind< 
of  stimuli  are  then  employed,  both  nf  the  same  order.  Iiro  vowel  sounds  tot 
iostanoe,  and  tlie  subject  is  directed  to  respond  to  one  vowel  with  (ho  right 
hand  and  lo  the  other  with  the  left  hand.  It  is  found,  the  subject  being 
right  knoded,  that  the  reaction  perio-I  i#  greater  when  theagoal  b  made  with 
IM  left  haild.  In  this  case  the  oetay  take^  place  not  iu  the  KOOgnition  of  th« 
etfbcts  of  the  atimubts.  nor  in  the  Drooeves  ihrougb  which  tlie  will  is  lVm«<l 
upon  that  recognition :  these  ore  tiie  same  in  the  two  ea^es ;  it  takes  place  in 
■  he  procMsn  by  which  the  wilt  is  brought  to  bear  on  the  nervous  motor  ap- 
I«r«Uia  for  making  the  tigujd,  on  the  vortical  origin,  for  exam|ii«,  of  the 


878  TH«  BBAIS. 

pyntnidal  tnct ;  Iheae  prooeaea  take  n  Inntc^r  time  in  ihe  ctim  of  tite  unic- 
rtistomod  left  hnnil  limn  in  the  cue  of  the  u«iinl  nclil  bend.  In  this  way 
we  obuin  k  mea>ure  of,  W  to  Ipeak,  the  volitional  sidi*  of  [isydiical  |<ir>- 
cewes. 

In  n  »nm(!wl)iit  ximilnr  vny  wti  miir  nhtntn  a  meanire  of  the  time  recuireJ 
for  ]M;rrrpttnn.  A  Mtmng  mnMition  fcillnvrini;  ton  cliwcly  upon  a  weak  one 
will  jiTTTont  the  p«vphi<^l  rocofrnilinn  of  lhi>  wmker  onf.  If,  for  inttanoe, 
tven  or  ihrm  Ictten  in  white  on  a  lilnck  hnck^ronnd  W  pnw-ntnl  to  iIip  •■yr, 
and  n  Inr)^  white  siirfncp  he  pron-nlcd  nfterwaH  at  an  int^rvnl  whitli  h 
mndi?i'ticcce!ivelT  "hortcrnni)  shnrler,  it  i»  found  ihnl  when  llip  inti>mlli 
nmdc  very  Iwief  indeed  the  letters  rannnt  bo  perceived  al  nil.  In  propnrliia 
«»  the  tiitprnit  is  proinnired,  tho  recojmilion  of  the  kttew  incn^w*.  nnlil  at 
an  inlervnl  of  about  0.05  gpcond  they  are  fully  nod  clearly  retvi^initnH. 
That  is  to  my.  the  time  rei)iiired  for  peroeplion  U  in  such  a  ca«>  nf  ahotl 
that  lenirth. 

The  dnmtion  of  all  these  psveliical  proeceaea.  as  of  the  simple  rrarltniB 
period  itself,  variea  of  course  under  different  cireumstances.  and  the  disi'Hmi- 
nation  period  may  beoonvcnienilj  used  for  measurements  of  the  varyiaj; 
effects  of  HrcumilanoM.  Pntclioe  shortens  ll»e  diiwriiDinstioo  periixl  a*  ii 
dnes  the  simple  r**!-!!!*!)  jieriod.  One  of  the  most  powerful  inlliieneea  is  llial 
of  ellralioD.  Aiid  it  is  stated  that  the  shnrteDinir  of  the  period  is  creatft 
when  Ihe  atirniion  is  cnni-enirated  on  the  mnkinic  of  the  aignnl  than  when  il 
to  more  MrwHally  dirrdcil  to  r(-c<>|fttilir>n  or  the  xiimuliis;  in  other  ««nll, 
the  volitioijal  prncessrv  are  more  ampnabli?  ibiin  are  the  perceptive  pmecMM 
to  the  piivfhiml  nctmn  which  we  call  atlUJiltun.  On  ihe  other  haiid.lht 
perimi  is  dirtinftly  prolnngwl  if  the  i)liiicrvi>r  h*-  dUlnwieil  by  C(inc»niiiani 
aensnitoDs.  For  ♦■namnlv,  thi- perioil  far  diMriminatine  lieiween  two  riml 
aensaliona  is  prolonj^  if  powerful  auditory  stinsat ions  he  eKnt4.il  at  the  MSI 
timf. 

The  *ame  method  of  measurement  may  be  used  in  other  waya  and  anda 
nther  eircunislanoes  with  reference  to  psychical  processes.  It  must  bo  mama- 
bered.  h'>wever.  that  all  such  nbaervations  arc  open  to  many  fallaewaaaj 
Deed  particular  eaution.  It  not  unfrequently  happens  that  falm  reealt*  u* 
obtained:  for  ioRtance,  the  subje<H,  eipeetinj;  the  stimulu*  to  be  hrmitrhl  t« 
bear  upon  him  and  straioin^  his  attention,  makes  the  signal  bcfir*  iht 
stimulus  actually  eonm  off"  And  the  interpretation  of  the  roaulia  obtaiaid 
are  in  many  anu-s.  verv  difBeult ;  but  it  would  be  out  of  place  to  d<*«U  vp» 
tli«M  matter*  nay  further  hero. 

TrB  LtmI-IIATIC  AltnAXUKUBHTS  OP  Tnii  BHAtX  AVD  Spikai.  Ooi& 

!  684.  The  mrmbranet  of  (A«  brain  and  ipinal  eord.  The  oerebr»«pllMl 
canal  in  lined  br  a  tou(>fi  lamellatcd  membraiw,  composed  of  cooiwrtit* 
tiaauc  with  a  small  amount  of  elastic  nctworlia,  colleil  the  •iura  mtUr,  whMi. 
Bomowhat  closely  adherent  to  the  walls  of  the  cranial  cavity,  is  sepanud 
fWtm  those  nF  the  vertebral  canal  by  a  oonslderable  apace,  contuinin);  blood- 
vewicls,  especially  l^ri.'e  venous  BinuMa,  and  some  fat.  Il  mity  be  cousiderej 
*»  a  development  of  the  periosteam  lining  the  wrehrunpinal  cavity.  It 
•eiMb  tubular  sheaths  for  some  distance  along  (he  i>rver.il  cranial  and  spiDal 
nervn  ;  and  forms  between  the  cerebral  hemisphere,  in  the  longitudinal 
IWure.  a  conspicuous  sickte-iihaped  vertical  fold,  tlui  fiUf  etrthrl,  a>  w«ll  m 
a  smaller  hnriK'mtal  or  ublir{Uo  fold  between  the  osrobellum  and  otrvbniai 
known  as  the  lenlarium. 

The  vascular  pia  iNa(«r  b  oloaely  attached  to  the  sur&ce  of  ibv  brnia  mi 


•piiul  cord,  dipping  down  n>  ite  liare  aecn  into  i)ie  vontrni  or  nnuHor  tiMiirc 
ul'  tbs  cord  M  well  lu  Into  iW  tiwure*  of  tlic  liruin.  8heiilli-like  invmtmvDU 
of  pia  mUcr  nit:  roDliniui]  nlnng  [be  •everiil  nerrcs  u  llicv  Icjiw  the  ccKbro- 
•|rilMi  CBviljr ;  nml  iu  ihig  v<Tt«bnil  cbiiiJ  ui  impvrfoct  jmrtiUun  Itnll'wmy 
biniKa)  llio  donal  and  wutml  nurlnci'*  of  tho  cord  is  funiiiilieil  br  «  moni- 
bniw  of  oonnecliTe  tiwuc  which,  ctniliiutoiiH  iiloii);  iiit  whole  length  wiih  iIk 
pis  mater,  in  atluched  to  Bn<l  IiihkI  with  thi;  dura  mater  at  iiilervab  only, 
uninely,  l»etwcrn  the  nucccMtve  nerve  r<joI)i.  .Siinic  iU  outer  etige  lio*  lhii»  it 
toolbod  ajipeaniiice,  ths  mciubrtttii;  i«  ml  led  the  li'ianieftnm  dmlieulatiim. 

»BalwMD  ih«  [Mft  muter  Dcxt  lo  tlie  brain  nnd  curd  niui  tliv  dora  maler  next 
to  ibo  bony  -HtiW*  i*  a  ovily,  which  is  divided  into  twu  bj  n  thin  membriiiic, 
ttir  nmi^fivid,  cnnipo^  '•!'  interwoven  bundles  of  coiinet-Uve  ti»ue.  Tlie 
tjisee  between  the  nrnchniiid  nnd  LhcdurK  mittf  it  culled  tho mthdunU tpOM, 
and  the  ipoee  betiroen  tho  urschnoid  and  thd  pin  mtiler  i»  called  the  <«i6> 
atwiinoiit  (fpaet.  When  tho  brain  ii  expt«eil  by  n-nioving  the  roof  of  thv 
•kiill  and  Hlitting  open  lh«  dura  mnter,  the  siibdurid  fjinco  it  Inid  bitre.  iind 
iJie  arachnoid  i«  seen  »trelcl>ing  over  the  pia  muter ;  to  the  vertebml  ennnl 
tbe  arachnoid  lies  clom  to  tfa«  dura  mnter.  so  that  UHiinlly,  when  the  dura 
nat«r  is  slit  open  and  tum«d  hack,  the  arachnoid  i»  carrieil  with  il  and  the 
cavity  exptwed  is  that  of  th«  mbanichuoid  epnee.  The  ani(;hiioid,  like  the 
dura  mater  and  the  piit  uiatcr,  iaoontinucd  for  some  distance  over  tbe  nerves 
•8  ibtty  leure  the  een-bro- spinal  eavity ;  bo  that  each  nerve  at  il«  exit  is  sur' 
KKloded  by  a  tubular  prolun|{atioD  of  the  Bubdural  Bpuce,  nod  wilbin  tbiB  a 
aiiuilar  tubular  proluuKBiiou  of  the  subaroohnoid  apai% 

The  Bulxlural  apace  itt  broken  up  to  a  alijtbt  «Ktent  only  by  bridles  carry- 
ini;  uervea  and  bloodvedaeK  especially  venous  sinuses,  between  the  pia  maler 
and  dura  mater,  and,  over  the  surface  of  the  brain,  by  villus-like  prujectioua 
ud'tbenranbnuid,  ctilleil  Pacchionian  glands,  some  of  wlUch  pierce  the  venous 
Mouses  of  the  dura  mater.  It  u  lined  throughout,  both  on  itt  dural  and  on 
iu  arachnoid  irall,  by  an  epithelium  of  Hat  epithelioid  oclls,  nnd  may  Ik 
oonipared  lo  B  wroii*  cavity  such  a*  that  of  the  peritoneum.  I>ike  tbeteroutt 
cavitit*  it  <.-ontnint  nonuiilly  n  small  ijuantity  iiiily  of  lluid,  and  ita  nu  la 
potential  nithrr  than  actual. 

Tliv  aubamchnoi'l  tpnco  on  the  other  hand  w,  wpccinlly  in  certain  rvgioua, 
such  as  thi'  donui)  portion)!  of  the  vertebral  canal  and  the  base  of  tlie  l>rain, 
iDucli  broken  up  by  bridles  of  coniMCtive  tinxue  pnniujf  from  it  to  tlie  pia 
malvr,  ns  well  os  by  a  network  or  s|ionge-like  arrangement  of  bundle  of 
counectivu  lii«ne  lying  immediately  benntlh  itself,  and  giving  it  when  viewed 
Irjoi  below  a  honeycomb  or  fenestrated  appearance.  Ihe  under  surface  of 
the  membrane  itself  iia  well  as  all  the  trabecule  of  the  tponge-irofic  and  the 
bridl<«  are  cuvereil  with  an  epithelium  of  flat  epithelioid  cells,  wliicb  is  con- 
tinued aim  over  the  pia  mater  and  the  ligamentum  denticulatum,  anti  lines 
the  tubular  sheatb-like  prolongations  of  the  space  along  the  issuin);  nerve 
rooit.  Tbe  subarachnoid  space  therefore,  like  the  subdural  space,  may  be 
mpirded  as  a  serous  or  large  lymphatic  spac«,  but  it  is  an  actual  not  a  mere 
puleotiat  apace  1  it  always  contains  an  appreciable  quantity  of  Duid,  whidi 
however  is  not  ordinary  lymph,  but  is  luniished  in  a  particular  way,  and 
devervei  «[)eoial  utudy.  To  understand  tiie  nature  and  origin  of  tliisemfcnt- 
epinalfiai'l,  u  it  ia  i-all«d.  we  mutt  turn  to  some  special  arraagninenu  of  tbe 
pia  mater. 

I  685.  The  [na  mater  pro]>«r,  conaiMing  of  interwoven  buitdlee  of  con- 

Deotive  tiaiue,  with   wine  dartio  ISbrer  and  a  considerable   number  of 

coBiMCtivc-iiatuv  ooqmaeba,  senrM  aa  wo  have  taid  a«  the  bearer  of  bluod- 

to  tbe  nervous  structures  which  it  invests.     The  imnll  arteries  oa  they 

into  the  nervoua  substance  by  tbe  way  of  tlio  septn  nra  surrounded  by 


878 


TOE    BRAlIT. 


fieri viidcular  lyniphuic  rannlji  with  trhicli  spocea  in  the  tmroglU  rtmibI* 
Murk  both  of  ibi;  bniiii  mid  ii[iiual  i-urd,  cvpeciallf  stisces  eumiiiBtna):  tta 
larger  nerre-cctlii,  ore  coniiiiiKiu*.  A»  i*  ibc  vote  iriih  other  ib»i»,  m  villi 
lh«  crntrnl  nfrvrtii*  *y>triti,  tbu  Mvcnil  elrnient*  of  tlw  iHWie  »n  batM 
«itb  Irniph  ikrivcil  ftom  ihe  bli>od;  ami  lliU,  oo/ing  througb  the  apMM  lata 
lh«  ptrivn^ubir  (■iiniiU  ntiil  tbi:  nihrr  lyinphutu*  vnm;lii  of  ihv  pla  HMUr, 
litakai  it*  way  iolo  ihc  nubHiiichDoid  vjihcv  ;  but  tbi;  fliiiti  in  the  wibamdlBiM 
tpacvi  ha«  oilier  •ounx's  bntiilcn. 

Tbe  roof  of  ibr  fourth  vnilriclc  iii,  aa  wn  hurt-  aaii)  ($  602),  rpducvd  to  a 
nioglr  InytT  of  111)11  iivrvnii*  I'oltininar  cpilbcliiini.  nbtch  Bpp4-an  aa  a  moc 
liniii^lii  lh«  |>iii  iimicr  ovi'tlyiiig  it.  Jii  ilu-  hiiiiirr  twrt  oflbi^  vrtitri(-l«  ihii 
rniif  i?  ptrfiiratnl  bv  a  iliMinct  narr^iw  oval  otififx',  the/oramrn  «/  .UaJ-iJir. 
hy  lhi«  orilicc,  Hlik'h  pti«c4«  right  tbroiigli  bulh  ibo  pin  rniilvr  aiiri  tlM 
uiKtrrlving  Inrvr  ofrpillidiiim.llivmvitT  of  the  Iburlh  vctitridc.  aiiiJ  so  iht 
11  hole  (criteof  ciiviiicHiU'rivciJ  fr>  in  the  original  mcdullariF'  cnnal,  the  laiml 
■od  ihinl  vcniridoK,  Ibc  ii'iiicdiicl.  and  tli«  crntial  cniial  of  tbi<  apiual  oord, 
are  niiide  cunlinuoUN  with  tne  »ubura<-bnoid  Rp4ic«.  Tli<rfv  ant  also  other  \tm 
coRfeplciioUB  cuniRiunii'nUone  bclUM'D  the  eubainclinoid  space  an<l  lh«-f'>unk 
v«Diri('Ie.  Il<'iii.'e  (lie  (erfliro-spiniil  lluid  in  made  coinn»on  to  all  thcM  obv{- 
li«»,  and  ia  furnteh^d  nd  only  by  llie  pia  maier  invealing  the  oulude  of  tlit 
brain  uod  tpinat  cord,  but  aim,  and  indeed  probablj  to  a  larger  extent,  bf 
ibe  epithelium  lining  1  lie  several  i.'aviiie«of  the  cerebrO'Spinal  itxit,  tapveuXtj 
)>erhii{ia  by  lh<«e  porlinrift  of  that  epiibeliuni  wbifh  coat  the  proonaea  of  fai 
iiinttr  priijectini;  iitlo  iljuHe  cavities  ut  certain  ptueea. 

We  eaw  jirevjouBly  (*  IJU3>  thai  a  lar^e  l»ld  of  the  pia  mater,  cnrryincto 
with  it  the  ibiu  non-nervou»epilb4^liuni  which  alone  frprniL-iila  nl  ibe  fiaM 
the  oTi|-iDal  wall  of  the  medullary  canal,  is  thruat  iiinanl  at  thi-  iran*Tprv 
fiaaure  of  tbo  brain,  b<-iii-nih  the  toniin:,  tn  form  thu  velum  iDturpuciium,  iku 
tnpplyiog  a  nuf  in  lb«  ihinl  ventricle,  and  that  it  ihanca  pnfjvcta  iota  tttk 
bili;ral  reatricle  an  llie  dioniid  ploxuv  of  Mcb  ntdu.  reaching  from  tbo  fuiv 
RM-n  of  Mouru  iu  fmut  along  ibe  ■■<Igr-  i>f  ttiv  I'urnis  to  the  li)i  of  tlw  detoMd* 
ing  horn.  The  velum  bi-irig  a  fold  of  the  piii  mat<T  con«ifl<  thcoreticall*  af 
two  Inyen",  ami  bclvteiti  the  upper  ilorMil  Inyi-r  ami  the  lower  Tcntral  laytr. 
I'm  a  ihin  bc<i  of  cinitieclivc  tiasue  carrying  nrtoriea  forward  from  the  hind 
Cilgc  of  ihv  corpUR  ciillu«um,  and  similarly  carrying  vvitu  backvarU:  them 
vrawla  »upply  the  choroid  plexuK  with  an  abundaot  nipply  of  blood.  In  the 
choroid  plvxiia.  the  fold<:'il  pin  mater  i«  develofwl  into  n  number  of  tiIIm- 
like  pniceMc*.  the  primary  prorcnscx  bi^iiring  secondary  onea.  Kadi  prucc* 
coiisisia,  like  a  villii*.  of  a  bii«i«  of  curinvctive  li<«ue,  iu  which  the  blomlveaadi 
end  in  cloec-«et  cii|>illary  I»iips,  covercil  wtihan  cpilheliuin.  The  epiiheliuin, 
though  conliouuu»  with  iIk'  rest  of  the  epithelium  lining  the  lnlera.1  vi-nirictt, 
and  tbiiis  oa  wc  have  said,  shutting  off  the  lateral  liNim  the  third  veniridt 
(except  at  tlic  litrHaicn  of  Monrn^  and  thoofjb  like  it  deriveil  front  the  wall 
of  the  ori;;inaI  medullary  canal,  in  dillereoi  in  structure.  Over  the  vnitiiele 
generally  the  epithelium  consiniii  of  ordinary  short  columnar,  npparvatl* 
viliatetl  cells  "ilh  more  or  leso  troiirpiireiit  («U  substance;  the  oolln  uvrr  tH 
choroid  ptexuH  arc-  cubical.  uHcn  irrej^iilur  in  form,  and  their  cell  aiihataDcc 
ia  loaded  with  granuleti.  M>me  of  whic-b  are  pi|fineniary.  Thejr  have  nrj 
uach  the  apjiearanee  of  "  active"  necKtiug  cella;  aitd  iodoed  a  branchM 
proceoa  of  the  plexun  may  bo  coinpared  to  an  everUvl  alvc<>lu»  of  n  ■veretiog 
eland,  wtib  the  epiihelium  uutHiih!  and  iho  bloo(tv>»L-lii  within.  It  c^niiut 
be  doubted  ibnl  these  i-elln  play  an  impuriant  iMrC  in  itecreting  into  the  ority 
of  ibe  ventricle  tluid  which,  pawing  tlK-iice  dv  the  foramoD  of  Monm  inUi 
Die  third  and  au  into  the  fourth  ventricle,  lindi)  ita  niiy  by  tb*  roraiuen  itf 
Uajeixlic  into  llw  tiiibnracbnoid  space. 


TUB    LTMPHATIC   ARRANOEUKN'TD    OF    THE    DRAIN.      679 

At  lh«  r«liitn  owrhRiiga  llie  (hiH  ventricle  it  w&cils  down  Tnticnlljr  two 
iigitudiiial  linctir  rHii^ce.  wlii<rti,  n.-*cnil>liiig  in  alructure  tli«  chcroid  plex- 
uvnof  the  Imtenl  vciilncic,  nre  cnllcd  lite  chonMd  plciusm  of  the  third  v«n- 
triele.  From  th«  rooruf  tho  f<3imh  vctilricle  (here  naogR  down  on  mch  side 
S  eimilnr  lincnr  tViiige,  tlie  choroid  plexus  of  the  fourth  ventricle,  which  is 
aii«cialljf  develope^l  al  iio  frunt  end  beD«a(h  the  overhsaging  eeretiellum. 
Tdcbc  oulnidiary  cboroiil  proceoECfl  doubtles  ueisl  in  furnishing  cerebro- 
•funnl  duid.  but  their  share  is  snuiU  coai{Mred  with  that  of  the  main  choroid 
plexiita?8  of  tlie  lateral  veotricte. 

i  686.  'J'lie  errrbro-rpiiuil  JIuiJ,  The  apeeituens  of  cerebro-apituU  fluid 
which  have  been  cxntnined  aa  to  their  cooipuitiituii  are  not  quite  ooiDparabte 
wilb  e«cli  other,  sioce  while  some  (aueh  aa  i.liuoe  obtained  Irom  cases  where 
•  ftaotore  of  the  haw  of  the  skull  has  plaoe<)  the  subarachnoid  epace  at  the 
baae  of  the  hraiii,  where  it  u  l>ri{ety  <icrvelo|>ed,  in  onoimunicatiuD  with  the 
exiemal  mentuK  aud  the  fluid  e*c')i|>e(t  by  the  ear)  niar  be  reicarded  as 
Donual,  otiient  (such  as  ihone  obtained  from  caseit  of  bvdruvephalua  where 
the  vviitriclea  contain  an  imusunl  •[Uaoiity  of  tluid.  or  Iruni  chhkh  >if  ajiinul 
nmlfiirniitliiiiia  I  muHi  be  (-oiuidi^rKd  ud  abnormal.  In  iuihI  of  the  more  oini> 
|iU-tr  iiualyM^.  ibi^  Hind  i-xiiuiiii«<l  hiia  belonged  to  the  lattvr  ctiba ;  nud  the 
lollooiiif;  HtalciueuiH  a|i|)ly.  strii'tly  s[>cakiQf[,  to  thvm  uloite. 

With  tbii  niiiiioii.  we  may  say  that  cetehru-iiiitDal  fluid  ia  a  tramparenl, 

wlotleMor  very  th^htlv  yctlnuinh  fluid,  of  fiiinl  alkaline  rMclion.  frvv  from 

bbtQlogioal  I'leiuciild.     I'hp  >|irt-ilio  gravity  t*  about  lOlU  or  Ium,  thi-  untouut 

iT  wilida  Ix-in^'  on  an  avrrni;)?  1  jirr  c-cdI.     Of  the3«  by  far  the  ervalor  part, 

1.0  or  U.S  per  oent.,  i*  *u|i|))ii.'d  by  nalla,  the  total  ijuanliiy  of  which  a*  well 

ibe  relative  amount  ol  the  iu;v<'ral  vooittiluenlji  being  about  the  mine  ni 
in  in  bloud  nnd  lyn>|>h.  The  coinpamtivv  dfficivncy  of  voUda  i*  due  to 
tin  Kifilineas  of  the  pnuviilA,  which  rarely  exceed  U.l  per  cent.  Thoe  are 
cbieHy  globulin  kimI  a  form  of  nlbumoee.  or  crcn  peptone ;  albumin  is  taid 
to  be  i^nerally  ahwnt.  The  fluid,  save  ap{HireniIy  in  exceptional  cases,  does 
Dot  cloi,  and  conlniii<>  iieilhcr  tihrogenoua  factors,  nor  flbrin  ferment.  It 
very  frequently  coniatiis  a  substance  which  like  dextrose  reduces  Fehling'a 
•oiuiiou  hut  which  is  not  a  sugar  ;  it  appears  to  be  pyrocatechiu  or  a  cloaely 
allied  iHMty. 

Heeing  that  a  fluid  of  such  a  coiupOsitioD  is  of  a  diflerent  nature  from 
ordinal^  lymph,  furnished  entirely  in  the  ordinary  way,  we  luifcht  be  inilincd 
lo  inter  that  probably  a  very  lar^e  part  of  the  whole  maas  of  the  fluid  it 
fuiniBbvd  by  the  aecretiuK  cpiihejiuiu  of  the  choroid  plexua.  Bui  it  must 
be  Uirne  in  miitd.  that  tlie  (uri-i;oii)>;  unalyaes  rvler  chiefly  lo  duid  appearing 
under  abnormal  circuiiiBtaiKvt.  aud  il  wuuld  be  hazardous  to  draw  any  wide 
tafeiriioe  from  them.  We  have  little  or  no  exact  esperiineDtal  evidence  aa 
to  hon  much  fluid  is  actually  secreted  by  the  choroid  plexuiee;  aud  if  tlie 
flui4K  which  have  been  nimiyusl  do  repre*eut  a  mixture  of  ordiiurr  lymph 
aupphcd  through  the  pia  inuter  with  the  jieculinr  ttecretiun  of  the  cboroiil 
plexun  and  cerehro-ipinal  omihI,  aoiuc  further  change  beyond  tlie  mere  niin* 
glingof  the  two  fluids  ia  needed  to  explain  the  remarkable  alMCnce  of  albumin 
wliii'li  liii-H  liren  to  ittrungly  insuted  ujKin  by  various  authort. 

j)  687.  We  may  fairly  auppoto  Uial  during  tite  the  duid  ia  oontiuually 
being  Mi)i(>lied,  from  the  ono  KXiroe  or  the  other ;  but  we  have  no  vrry  exact 
knowbngv  ai  (o  the  rate  al  which  it  ia  funiLdietl.  In  the  dog,  the  fluid  haa 
n  ot>M;rve'l  to  i^ncJipe  at  ii  rale  varying  very  lar^gely  under  diderent  cir- 
cuinstitnccf.  anil  ranging  fomi  1  c.c.  in  Tbrty  minute*  lo  a«  much  a*  1  co- 
in six  ininutrs,  the  i4mil  i|iinniity  discharged  in  twenty-four  hours  varying 
Irom  '-Hi  cc.  to  'J4U  c.c.  In  the  casea  of  fracture  of  the  base  of  the  skull 
lucuiiuued  above,  a  very  coosidcrabic  flow  haa  been  frequently  obecrvcd ; 


«■  ,1, 
Bbeii 


i 


TRIE  BBAIK. 


but  it  may  be  d'>ubt«cl  wliethi?r  th«  abnormal  circumsdiDoes  of  such  an 
have  not  raited  the  Kcretioii  above  the  Donoal.  The  rate  of  Sow  was  futunl 
ID  lh<!  dug  to  be  much  increased  hv  the  injection  of  aubsunoeB  (nonuBl  Mtliot 
euluiiun)  iuto  the  btood,  but  to  be  relaiively  litlle  infltienced  bv  anifical 
heightening  of  arterial  preaaure.  This  has  been  put  fifrnard  *a  indinun^ 
that  the  lluid  ia  chielly  fnniished  as  a  eecrelioii  sod  oot  ua  au  unUoai; 
iraneudntion  of  lymjil) ;  but  it  cannot  be  regarded  u  attoidiug  »  valid  arga- 
roeni.  The  preeaure  under  irhkh  the  fluid  exists  b  also  very  variable ;  it  ii 
olueely  dependent  on  ibe  viiscular  arruo^emeuts  of  whkh  we  almll  linTvto 
speak  presently.  In  ilie  dof{  tliu  averajj^  pressure  baa  b«eu  cMitnaiMl  u 
aoout  I'J  mm.  of  mercury. 

II'  the  fluid  i«  thus  cunlinually  formed  it  muHt  alvmy*  liiid  a  aummtl 
eeeai>e.  This  is  probably  supplied  by  tfa«  tubular  pnjl<>ngnii<inN  of  thvaulK 
arachnoid  space  along  the  iiervo  i-oota ,  these  are  oontiimous  with  (hv  lympb- 
aiie  vesulsof  ibe  nervts,  and  so  uiih  lli«  lymphatics  of  the  body  gtoijwji 
and  in  the  skull,  the  |>asaagesof  this  kind  aiou),' tliv  cniiiial  uvrvm,  etpttiulj 
uUiiig  the  two  uulk-  nerves  into  tli«  urbiln,  nllbrd  a  rculy  tneuis  of  iKMa. 
it  i»  all")  ur);e(t  that  some  of  the  lluid  etcapes  through  the  PacchioBiaa 
^luDiU  directly  into  the  hlfwl  of  the  venous  nnuMw.  In  a  d«ul  budy  flaiil 
ininiduved  iiito  the  sulrararhuoid  ii|tncu  through  an  opening  owr  lli«  hulK 
dbapiienrs  at  even  a  very  low  iin-murc  with  ^rcat  raptdily.  Thi-  cimi*- 
nlaiK'iii  then  are,  however,  not  the  mmc  a*  in  lifv ;  nnii  the  ftv  pxperin>aita 
mhich  bttvo  been  made  seem  to  «liow  thai,  during  life,  n  sonienhat  hi^ 
pri-Mtirtr  in  re(|uireil  to  swure  the  escape  of  (laid  iiilnnlueeil  in  additioD  It 
that  naturally  inwn![«d.  Thus  it  is  Ktiilcd  thai  when  in  a  dog  normal  mlm 
lolulidQ  i*  inlniduocd  into  the  subarachnoid  caviiy  at  the  loirer  end  of  tk 
epiuid  cord  very  litlh^  ri.'«iir]>lion  lak<'«  place  so  long  aa  the  pieswn 
rontains  b«  low  ns  nbout  10  c.  c.  of  mercury ;  as  the  preraure  b  JncrtawJ 
beyond  this  rcior]ition  (juickly  iucreoses.  Ilut  it  may  be  do^ihtnl  nbethfr 
the  resorption  of  added  fluid  is  n  fair  leel  of  the  a»cai>e  of  lluid  nalurallt 
preteut ;  and  (he  exiwrinient  Is  of  value  mther  as  showing  simply  that  thHC 
are  lueans  of  escape  than  as  aClbrdtng  a  lueasure  of  the  rate  of  caopfe  B» 
sides,  the  immediate  effecis  of  applying  pressure  at  lli«  caudal  end  of  i^ 
spinal  curd  are  not  the  same  as  ihuse  ol'  applying  the  preauirt  witbio  lb 
skull. 

The  rale  of  possible  escape  is  not  without  importance  urn  regards  lb 
mechanical  ioiportauce  of  the  <«r(--hrO'SpiDal  lluid.  Thus  it  has  b«aa  lUgld 
tJiat  when  an  extra  ({uantily  of  blood  is  driven  into  the  skull,  any  injuiiow 
intcrcmuial  compreesion  is  prevented,  not  only  by  iImt  tran^lerviic'e  of  a  «t^ 
irspiinding  quantity  of  cercbro-spinal  fluid  tfaTOUgk  titc  ft>rameji  of  Mintodit 
fmni  the  cranium  into  ibe  Mpiiial  canal,  the  walls  of  which  nru  lees  nfM^ 
complete,  but  also  by  the  direct  escape  of  tlie  fluid  from  (he  cavity  of  Ibe 
tkull  along  ihct  cranial  nerves  in  the  manner  denrrilxMl.  It  has  also  hnn 
urgtil  Ihnl  the  fluid  at  Uw  base  of  the  »knll,  in  the  largv  miharnchnnid  spaon 
of  nthich  it  gutheni  in  larger  quanlily  than  elsewhere,  ad*  an  n  s»n  of  pr» 
tcctive  water  cunhiun  to  the  delicate  cerebral  substance,  and  thai,  in  gvnenl, 
the  prxiN'nn)  of  the  fluid  is  mechanicully  usoful  to  ihe  wel&ro  of  the  bnua, 
rcHKivnl  of  the  fluiil  by  aspiration  being  said  lo  lead  to  bemorrliage  from  the 
pia  maCrr  and  to  various  nervous  divordcrs.  But  our  knowledgo  u  lo  the 
part  which  the  fluid  playit  is  at  present  very  imperfect ;  and  its  very  peculiar 
chemical  characteni  suggest  that  ii  has  sorac  chemical  as  well  at  least  si 
iMcbauical  functions. 


?B^TAflODLA^ERHANOBMBJ?T^^TH^BBAIN.      881 


Tbe  VAsc-vtuK  Arranoemcntb  op  the  Braik  and  BriKAI.  COHD. 

$  098.  Tlic  bloodvcwels  reach  the  nervous  Blnictures  by  roeauii  of  the  |na 
nitiirr.  In  llie  aiiiiial  curd  nrtcricii  cuming  fr»iii  the  vertebral,  iDterfuaial, 
anil  utber  arteriee,  anil  travelling  iiloiij^  the  nerve  ruotd  join  the  pis  lualer, 
anil  Uk-r  lhn>ui;h  the  liwiurcii  and  wptn  n^ch  all  purls  ut  the  oottl ;  but,  na 
we  have  prrvi'iuisly  rvmarked,  tho  capillary  tietwurk  t»  much  deiiaer,  au<l 
Ibcivriro  the  bloml  mpply  much  f^rcater  in  llie  gray  than  in  tiie  whil« 
malUT.  The  x-faia,  also  giilhemi  up  iilong  tliu  iieptA  aixl  tiwurea  into  ibe 
|tia  niatiT,  ih<i«>G  cuniiug  IWiin  the  gray  matter  forming,  l>ffi)iv  thrjr  rtqu'h 
Um  extrrtifll  pia  niatcr,  ii  (■■>■■■  pi cuoii.i  longtluilinal  vein  on  eut'h  Kidv  nf  tlio 
|MMarior  gray  cuiuniiwure,  puvK  Ironi  tho  piu  miilvr  to  the  large  renotia 
MliuMa  of  lh«  diiru  niiiter  nml  »i>  to  ii(lji.)tniug  vdna. 

In  the  hrnin  two  iinporliiiil  iVqitiirtv  of  th«  dutribulioD  uf  the  arteriw 
<l«<TVe  cpcriiil  uiK-nlinn.  In  the  tiril  pinrr,  tin-  iiuiidruiile  viipply  by  tbo 
right  anil  Icti  «'rli>hr«l  and  inlcrniil  ciirolid  nrttric"  i»  nia<lc  nnv  hy  renuirk- 
able  aua»|i>ni<«<-»  f'irniing  the  nrrtc  of  H'lllU.  The  right  nttd  li'iV  vertebral 
arleriea  entering  thi.-  rerictiml  cMtiiil  nt  the  U-vcI  of  tli'^  sixth  cer^'icnl  vcr> 
lehra  ami  running  l'i>rwBrtl  toward  tJte  bniiii  join  hcticath  the  ventral  Mirbc« 
of  the  hitlb  to  Torm  the  *ingle  median  liiwilur  arirry.  This,  niti-r  giving  afl' 
brmnehes  to  Ihv  kult),  cercUelhim.  and  {>ons,  divides  into  the  right  and  left 
poeWriof  ocrehnil  iirteriiw,  Each  inicriinl  carotid  entering  the  skull  readies 
the  blue  of  the  brain  in  tho  region  of  tho  Door  of  the  third  ventricle,  and, 
pataiog  ventral  to  and  athvori  too  optic  tract,  gii-es  otTlhc  large  and  impur- 
tutt  middle  cerebrnl  artery  along  the  ti^suro  of  rfylviut,  and  then,  luroiug 
forward  and  toward  the  DiMiBO  line,  puMes  duraal  to  the  optic  nerve  to  eoa 
in  tbe  anterior  cerebral  art«ry.  Just,  however,  sa  it  giv«a  oA'  the  middle 
■rlery,  it  sends  backward,  inclining  to  the  middle  line,  a  relatively  large 
bnacb,  the  puaterior  cxiiuniunicutiug  uriery.  which  joinx  the  poetctior  cere- 
bral near  the  origin  of  thin  fn>m  the  basilar  uriery.  Moreover,  the  tw4 
anterior  cerebral  urteriu,  amm  after  they  have  criMed  th«  optic  nervei,  jual 
M  tbey  ure  about  to  run  straight  forward  ulong  the  ftontal  lobes,  are  joined 
lonelier  by  a  dboft.  ivide  brunch,  the  anteriur  comrauiiicaling  artery.  la 
thw  uny  tlM  vertebral  arterieH  through  tbe  Wilur  artery  join  with  ihcu 
carotid  artrrie*  to  furin  uruiind  the  optic  chiaxnia  Ixiucath  ihe  floor  of  tbsr 
tbinj  Tcntricli-  an  arterial  circle,  Ihe  circle  uf  Willis. 

BIoihI  can  piiM  along  thin  circle  in  vnrioii*  way^i — from  the  bu^ilar  arlerr 
■long  the  right  podteriur  comniuntniting  artery  to  the  right  internal  cnruliu, 
aii<l  «o  by  tlie  right  anterior  cerebral  artery  and  anterior  conimutiiaUiiig 
uriery  to  the  Icll  Hide  of  tlie  circle,  and  siniilurly  from  the  basilar  artery 
along  tbo  led  stile  to  tbe  right,  or  from  the  right  or  frtrni  llie  lell  canitid 
through  the  circle,  to  the  right  band  or  to  the  lv(l  hand  in  vuch  ease.     Sine*  j 
the  channel  of  the  circle  is  a  (airlv  wide  one,  the  jMUwagc  in  various  dimciioni  ^ 
is  an  easy  one ;  all  th«  vrtvels  nidmiing  from  the  circle,  including  the  biwilar  i 
artery  nnd  ils  branchtw.  can  lie  siipplirid  by  the  carutida  alone,  or  by  tite  ver- 
lebrnls  alKue,  or  oven  by  one  rurutid  or  one  vertebral  alone.     In  this  way  an 
ample  Rupply  of  blood  lo  the  brain  is  M-cnrc<l  in  the  face  of  any  hindrance 
to  the  Hoir  of  blixnl  along  any  one  of  tho  four  channels. 

In  what  muy  perhaps  be  consi<lered  tbe  usual  arrangement,  the  («libr«  < 
ihe  pislerior  coiiiniiiiiicating  arteries  is  rather  smaller  than  tbe  other  pu 
of  iIh'  circle,  to  that,  oiher  things  being  e^jnal.  moat  of  the  vertebral  bla 
will  |iafe  by  the  ptieterior  cerebral  arlenca,  while  the  carotid  blood  ptMa  tO  , 
ihe  middle  und  anterior  cerebral  urleries  ;  but  many  variations  are  met  with. 
We  uny  also  here  i>erha]>a  cull  to  uiin<l  the  fuel  that  the  kii  carotid  coming 

M 


882 


THE    BltAI^. 


off  from  lb«  top  of  the  aorla  ofTere  a  more  »tnii)jht  paib  fur  [Iw  blood  than 
don  llw  right  carolid  which  com»  ofl'  from  lh«  lODominiile  arlerjr. 

AniillKir  Bpecial  fenlure  of  the  artenal  itip])ly  to  the  braia  is  thai  4) 
three  Innje  cerebral  arieriea — puBierior,  middle,  aod  anterior — are  diiuibf- 
tod  alnuMt  exdmivelv  lo  tlie  coriex  sad  to  the  sul^aeeat  vhiie  inaiter,  «kilt 
th«  dr^jier  twrtt  of  the  heiuisphere,  the  nucleus  raudatiis,  llialainiiE,  aM  tht 
like,  with  the  cap»iile  aiid  oiher  adjoiniiifc  tibite  nuilt«r,  are  mippliol  hi 
iniallur  arteriffl  i-»iiiiDf:  direct  fn>ni  the  circle  uf  WiHin,  or  fmrn  the  tmj 
breinniiign  of  the  llirte  cerebriil  art^rie*^  Ii  in  Mated  that  then:  two  Mrliflt 
mnicu  DO  auafiiriiiiiveit  with  ench  oiher;  but  thi»  nnpeani  to  varr  mtirh  in  diT- 
fcrciit  iiidividiiulB  We  iiiii)'  add  that  lli«  antvnur  cerebral  arti^rv  riuiiplin 
the  c'lrtex  uf  the  ilnraal  HHpect  iil'  the  Ircintal  I»bc  a»  o-ell  a*  the  fn>ni  aid 
niiddle  pirtioDH  of  the  whole  ineajal  Hurface  of  the  bcmiiiphcre ;  nhil*'  the 
middle  cerebral,  alwuvs  lar^f,  U  diiitribut«ij  f>  the  tide  of  th«  brain,  that  a, 
till;  jiarietal  lobe,  wltb  the  ventral  [lart  of  ibc  frontal  lobe  and  thr  dunal 
part  uf  tli«  temporal  lobe ;  the  uoiilcrinr  cvrebral  ■npplyiiig  thv  rot  of  ihr 
cortex,  that  is  to  aay  the  occipital  lobi;,  inchidioK  the  bind  part  of  the  TonU 
turfacv  of  hemidphere,  toffcther  with  the  ventrnf  part  of  th«  tOin|><>nil  liiht. 
The  dixtribution  of  ihi.'M;  ant^not  ilivn-f'Te  doea  not  correapood  Ut  fubctioul 
diviirionii,  for  nbilc  the  middle  ren-brul  Kuppliiv  a  large  part  of  tbe  iDotw 
region,  it  doen  not  mipply  the  whi.ile  ol'  it,  and  dot-*  »(i)>|ily  ]>ari«  uuulde  tl. 
Though  ihcRii.all  arterial  a«  they  run  in  the  pia  mater  un  the  Hirfnc«  iif  th 
cortex  a]iiu>l<>ni(ii,f  freely,  there  i«  very  little  nDa»toiDOM>  betvpeen  lh«  mall 
artsrios  wbieh,  Waving  the  pia  mater,  dip  dowD  into  th«  mbataDca  of  tit 
braio;  bence,  wlien  tlK^e  hiller  nrleries  are  blocked,  tbe  nutrition  of  Ik 
part  of  the  cortex  supplied  by  tbeni  i«  apl  lo  \k  impaired. 

S  699.  The  venous  arrange  men  la  uf  the  hrnin  have  v«ry  epeciHl  ehM- 
acters. 

Along  the  i)pf>er  cimvex  border  of  the  siekle-shaped  fold  of  dura  BlUr. 
tW  fatx  cerebii,  in  devel»ped  a  lar^e  venous  oiiiuti,  the  mperurr  tongitu^ml 
Wiititi.  Tbia.  triangular  In  Hx-liou,  increueiujt  in  calibre  from  bviorv  back- 
wanl.  \d  a  einiift.  nm  a  vein  ;  it«  ukIIh  are  |i>ro>ed  of  ii'rtbing  but  cwooeditt 
tiMue  lined  with  epithelium,  musL-uIar  elemeiita  being  cniirtly  nbwm.  Thuu);b 
iti  dianuel  ia  broken  by  bridlea  i>f  conn«ciive  tintue  pnMing  acnaa  it,  it  pw 
•eanauo  valves,  and  iudeed  theee  are  a  Wot  from  all  the  niniiiH'J'  and  reiurf 
llie  braiu.  Miidt  of  the  blooil  r«tii  ruing  from  the  oortex  and  ttuhjaomt  while 
matter  i»  carried  itito  this  ainua  by  veina,  tbe  mouths  of  wliicb  arc  fur  tbt 
moul  part  directed  furnanl,  that  is  tn  oav,  agaimil  ll>e  direction  of  the  falooJ 
Klmm.  Aliiiig  the  lower  concave  bonier  of  tlw  lalx  in  a  ximilar  liaiM,  tL( 
inftri'tr  fon^iluiliiial  rinut,  which,  however,  b  tmali,  and  into  which  rtla- 
tircly  few  veins  o|M-n. 

From  the  deeper  purl*  of  the  bruin,  and  Ofperially  from  th<'  ebttnid 
plexuii.  blood  id  coiiveycil  bv  the  vritm  uj  Oalrn  along  the  velum  inlcrpoiitaiB 
to  the  iransvcr:^  fismre.  wbcn;  the  veins  of  Ctalen  join  ihc  inferior  longi- 
tudiiial  siiuis  to  foi  III  llie  ••Irati/hl  <ri'iiii*.  This,  running  along  tbu  line  formal 
by  the  inter>ecti(in  of  the  vertical  lalx  wiih  the  (mora  or  leasi  bortiuwal 
tentorium.  Joins  tb<-  end  uf  the  superior  longitudinal  nnus  to  form  tW 
twcrvoir  or  cellar,  called  the  tortiilnr  Hm/jtMi,  j'nim  which  tlie  l-tlrml  timut, 
pHEsing  on  each  xide  along  the  convex  border  of  the  tentorium  and  gallMTUg 
veina  from  the  cereliellum  and  hiiid  regioDS,  as  well  ns  from  the  base  of  lb* 
brain,  delivcre  the  blood  into  the  internal  jugular  vein. 

It  obould  be  added  that  veins  from  the  noee  and,  through  th«  dpbtlialair 
reioH,  from  the  face  join  the  veins  and  ainnaea  of  the  braiD,  and  that  tbe  to- 
called  emiaaary  veins  pass  through  the  crsuiiim  from  the  scalp  to  tlie  tuperiur 
lou){iludtual  and  lateral  sintites. 


THE   TASCOtAB   ARBA:rOC]tEyTS  OP  TITB   BRAIN*. 


I 


t 


t 


I 


Tin  flibanneb  for  (he  venous  blood  of  the  braia  are  therefore  nol  veiiB,  but 
ftiDUMs;  not  to  much  tubas  for  muiDCainini;  a  uiiifarn  curr«tit,  w  longi- 
tudinul  r«aervoirB,  which,  while  affurding  an  ea^v  onward  path,  cno  also  De 
euily  lillcd  and  eǤilir  emplied,  and  io  which  the  blood  caa  move  to  and  tVo 
withoul  the  reelrictions  of  valves.  ThU  arranj^enieol  is  conelated  to  thu 
peculiar  surrou»diuj^>s  *if  the  brain,  which  is  not  like  other  or;pin9,  protected 
itiervlv  bv  dkiii  or  other  exieiisible  or  eluaiic  tuwue,  bm  id  enciued  by  a  fairly 
r<iB)p(ele  in«xlcnaibli!  eiivelo{>e.  the  dkull.  Aa  a  cutiMK|ueoce  of  this,  wh«a 
at  any  time  an  extra  quantity  of  bluoil  ia  aeul  fr»Ri  Ihe  heart  to  the  brain 
room  muit  be  made  for  it  by  the  iucreiiMMl  exit  of  the  fluids  already  present. 
For  any  prcwurv  on  the  brntn-HulMliiui-e  beyond  a  ceriniu  limit  in  injurioua 
to  its  welfure  and  a^-tivitr.  as  is  seen  in  certfliti  maladies,  where  bluod  pawing 
bv  rupture  of  th«  bliHMlvenael.i  uuC  of  ii«  n'>rmiil  chnnuels  remains  efTiiMd  on 
tbe  surface  of  the  bi«En  or  et«ewhere,  and  thu«  takiu^c  up  the  room  of  the 

1tni]i«r  hmin  Hutxttanee  lends,  by  "com]>r«iHioii,"  as  it  u  callud,  to  pamlyvia, 
•  m»  of  coiwciouMiwv,  or  dnilh.  Some  room  m»y.  os  we  have  Men  f§  6S7), 
b«t  providnl  by  the  i^^ape  of  cerebrn-spinal  ttuid  from  the  tknll.  But, 
within  the  liuiila  of  the  normal  cerabnil  einmlnticm.  the  characlerislio 
venous  iiiimttni  i-Dpec^ially  Morve  to  regiilalo  the  internal  prMsurr  ;  they  fcirtn 
temporary  nwrvoin  from  which  a  uomparalively  lur^-  quantity  of  blood 
can  Im  rapidly  divcharKi'd  frnm  the  cranium,  the  flow  from  the  sinnHo  being 
greatly  aiviitMl  by  the  low  or  nvgntive  pnmure  obtainin);  in  the  veins  of  the 
neck  at  each  inspiratory  aiovrnwnt  i>f  the  chest. 

S  700,  The  cupplf  of  hlootl  to  the  hrsin  sM-ms  at  first  sight  nol  to  corrs- 
spund  to  the  ira|>iirliince  of  this  the  chief  organ  of  tbcbixlv.  In  the  nibhil  it 
would  amx-ar  that  hardly  more  than  one  per  cent,  of  tde  total  ijimnTicy  of 
the  bloo<l  of  lh*r  tuxly  is  present  at  any  ona  time  In  the  brain,  a  lunniily  but 
little  more  Ihau  half  that  which  is  found  in  the  kidneys;  and  white  the 
weight  of  bloml  iu  the  brain  at  nity  one  time  amounts  to  about  live  per  cent, 
of  the  total  weight  of  the  organ,  beioj;  about  the  same  as  in  the  miiaelee,  in 
the  kidney  it  amounts  to  nearly  twelve  |*er  cent.,  and  in  the  liver  lo  as  much 
IIS  nc«rly  thirty  per  eetil.  Mnking  every  allowance  for  the  relative  small 
•iie  and  functional  impurtUDce  of  the  rabbit's  brain,  the  bhHxIsupply  of 
even  tl»e  human  brain  must  still  be  small ;  and  making  every  athiwanoe  for 
rapidity  of  current,  the  interchange  between  the  blood  and  the  nerrmti 
alenienu  luuat  also  be  small.  In  otner  wnrdA.  tiM  metahulism  of  the  bnln- 
•uhstAtie*  b  of  impurliinee  not  so  much  on  account  of  ita  quantity  m  of  it< 
spMiRl  qnmlitica. 

The  drvubtion  in  the  brain  may  he  ntudicd  bv  help  of  rarioiu  in«th'wt*. 
A  ncnoineter  may  be  connecied  with  the  jieApkrral  end  of  the  ilivid.-d 
inMnul  carotid  artery,  n  second  maiiomrler  being  alluchiKl  in  the  it^ual  way 
U>  th*  central  |H>rti'JU.  Since  the  pcriphL-nil  manometer  reconi*  the  blooil- 
pnwure  in  the*  circlii  of  Willis  transrniiied  alonjc  the  peripheral  portion  of 
the  carotid  artrry,  varinlion*  of  iiremin^  in  llie  ctrcle  of  Willis  may  thu*  be 
attidivi] ;  ami  a  comparii>on  of  the  pc'riplientl  with  the  central  manometer 
will  indinle  what  general  changes  are  taking  place  in  the  circulation 
ihrmigb  the  brain,  Thus  a  fall  of  prtwure  in  the  peripheral  manoraoter 
unanN>mpimicd  by  any  corm|M>iiding  fall  in  the  centra)  minomcter  would 
show  that  ib«  "  |)eriphcnil  resistance "  in  the  brain  was  being  lowered,  in 
other  words,  that  thw  vessels  were  being  dilated. 

In  another  melhoil,  in  the  dog,  th«  outflow  of  venous  blood  from  the 
lateral  ndus  through  the  posterior  fncinl  vein  has  been  msMured.  The 
freetlom  with  wbii-h  blood  passes  along  the  sinuses  juslilios  the  ueamption 
tliat  the  outflow  through  the  opeu  reiu  gis-es  an  appruximaie  ineuiire  of  the 


THR   BBAIS. 


■SCI;  I 


mu  of  fl«v  ttDdcr  MUiiml  cMtdiikM :  «EB  fk* 
aad  bnUm.  Um  coMivMd  kw  «r  UmJ 
A  lUnl  Mtbod  b  >  pktbyHM^^kfe  «M. 

lb*  rij^  banaf  btMi  nmvftd'  br  ibt 
belt,  Md  tbt  wmsnto  of  iW  Mnb 
utd  Unror  AneUy  bj'aJew.    layvaag 
Ika  of  IW  cnMO)  aol  jrH  «mScd.  b^  U 

Aod  it!  noraanta  noorwd  in  ■  KBilsr  am 

fluJ  to  ibc  bde  in  B  «ster-ti^bt  Bwacr.  U 

btcnMi  pr^nin :  uxl  oe  bs^  uk«  it  fcr 

mcd,  that  pester  or  lea  pnnw*  m  4m  I»  bor  b 

U>  Um  bnw-     B«t  ibe  uaocnl  «f  ffBuia  kcB^ls  *•  h 

iiMtraowftt  ■ill  bImi  (kiwsd  on  IM  fLifiaf  nib  win 

fluid  ncapca  frMD  tbe  cxTiif  of  tbc  ilivll :  if  iha*  W 

ocape,  or  on  tbe  otber  fautd  sn  i»crtBgJ  fiaBly  af 

crtwe  of  wpplf  of  blood  will  piwiace  ia  oaa  cm*  a 

inhaler  norentat  of  ibe  Icrcr.     If  tbe  Btabcaae  be 

ilie  hule  BO  as  to  allow  free  ocape  of  tbe 

(ftatrtically  taiinf;  >m  llie  lurfsre  of  ibe  a 

rrconla  Tariaiiom  in  the  dorao-v«-ntnI  diaaWer  af 

Ibne  laaj  be  taken  as  neaHtriDK  VBriaiima  ia  ibe 

■0  in  tbe  blwrfl  Huifpl^.     Id  n*-iih«r  furtn.  howercr,  d«a  iba 

Eive  (M  all  llie  itifurmaiiuu  «btL-li  we  want.    Aa  taiTCBa 
rain,  aod  tberdore  au  «x[^quuiuii  uf  the  Imia,  and  §«  a 
n^u^iag  inXrtiiiiriit,  rmv  i««ilt  ntbcr  intm  a  fnUtw 
fron  hMrance  Iv  the  vtooiw  oalfluw  ;  tbe  ibi 
iDcat  run.  favorable  to.  ibe  laiur  alwaja  aad  liaiiaLily 
aclii'iljr  nT  thi-  iM'tvi>uit  *(ruc-lur<i 
lie  rurrtiinl  liv  a  liniiiliBiM^OB 


tolfct 


A: 

benca  tbe  teacU*^  at  tbe  keer  aa« 

__  ubcvrvaticio  of  the  naral  arteria}  ptwt 

sod  »r  ibc  blux)  (irtwure  in  lbs  vetna  of  tbt-  ovvk.  Muewntr.  tbw  aryaaw 
wUicb  wv  uMtl  'i  4)^>  in  refrrenrc  to  the  kidnrj  bbj  beafi|djed  bmiad 
I'tubably  wilb  cfual  lurcr,  namcljr,  lint  iho  vaJoe  of  tba  bmd  aUaa  to 
tilt  uutritioo  uf  ibe  lirnuc  is  ikjiendrnt  not  atoae  on  tbe  SBenM  af  Ua^ 
|>r«Mire,  bat  alto  and  n|iecially  on  tbe  rapidiiy  of  tba  Horn  •  inihid.lfca 
Mcioond  factor  i*  of  parliculBr  im[H>rlance  in  view  at  tba  aeed  of  wipffliat 
tbe  nrrTOUB  «kn»cnl>  wilb  an  Bik((UBte  inlercbaDp  of  gaega.  Sam  4)i  At 
rapMlrty  of  flow  tbe  pin  byBmograpbic  method  ata  i^ve  us  iadifaei  ii^ttmt- 
lioB  unljr. 

t  701.  Djr  one  or  otber  or  nil  of  iliew  method*,  certaia  inportaM  ku 
have  lieen  laode  ouU  Tbe  volume  of  ibe  brain,  as  deleriBined  tif  Ikt 
BuiouDt  or  blood  present  in  it,  is  coniiiiuouiy  aadeifoing  cbanga  bnagk 
nbiiut  by  varioaa  cauHiL  Kacli  lieart-b««t  makes  hadf  viable  oa  Ibe  em- 
liral  BB  ou  the  renal  plelhy«iui>;;ra|>bic  tracing,  and  as  we  ban  ma  in 
•(■cakini;  of  rvtpirslion,  tbe  diminuiiuD  of  prraure  in  tbe  great  vciaa  of  tbr 
ti*^-k  during  iiiapirmii»n  lesils  to  a  abrinkin);,  and  the  reverie  ebaage  durinf 
rxiniaiion  lo  a  swelliii}(  uf  the  bniin.  Thv  plelbyan(^rB|A  alan  shows  vans- 
ii<iiii>,  Inrgvr  and  slower  tbau  tbe  retpiratorv  imduUiiou.-.  and  brouehl  ab«al 
by  various  causes,  sucb  as  ibe  position  uf  ilie  beed  in  ri-laiion  to  wo  Inink, 
inovenienia  of  tbe  liinbe,  roodilicaiinua  of  ibe  renpiraiurv  moveintnta,  »ai 
upparruily  pbnses  of  activity  of  ibe  bniu  ilvetf,  a*  in  wading  and  tlcepiog; 
iitidiilatione  corrvspondinft  to  ibe  Tmube-IIcnng  variaiioua  ($  3$t(}  «f 
liluwI-prtBure  ntaj  not  unfrequeully  be  glmer^ttl. 

All  ibe  vartuua  melliods  Hbuw  tbiit  lliv  flow  through  tbe  brain  is  birg^f 
dHcrmincd  by  u  vatooMlor  acliun  of  nonic  kind  ur  another.     And  ibb  vs 


[AiN.     883 


I 


I 


I 


might  initwd  infer  from  onlinnrr  eiperieiice.  When  tbe  head  is  i^irdttcnly 
ahiOed  fmin  the  eKcl  to  a  han^-iii;;  ]io»iilioD,  there  muM  be  n  t^ndencv  tor 
the  blood  to  aceuii)ulaC«  iu  the  cranial  cavity,  and  Cfjnveniely  when  the  head 
M  Baddenlr  shiAed  from  a  han^Jii^  to  an  erect  piMitioQ,  there  mual  be  a 
tendency  fn  the  supply  of  blood  within  the  cranium  to  be  for  a  while  Icm 
than  normal.  K>tber  ohaDg«  of  fxisitton.  and  especially  perhajM  the  latter, 
would  Iea«l  to  («rebral  dijilurbinces,  which  in  turn  would  in  oiirwlve)  be 
revealed  by  affectiouB  of  our  conauiouaneia.  Thai  a  jierleotly  healthy  and 
especially  youn^  or^iiuitu  whi»e  Tasoniotnr  niechanlsinj  are  at  nnoe  eReotive 
BD(I  delicately  reipi>iu,ive,  can  i>aas  nwiflly  frnni  one  jiu«iti<ia  nf  the  head  to 
the  other  wiihuut  ioctrnventein-e,  whcreiut  thoM  iu  whom  the  vii*imi>tor 
mecfaauisma  have  by  aic«  or  olherwiac  boome  imperfect  are  giddy  when 
Uiey  attempt  tuoh  rupii)  chani^,  U  in  itaclf  adequal*  evidence  of  the  ini- 
|>»nnnc«  of  the  vaaumntor  arrangemenla  sifbctinE  the  circulation  throiij(h 
iIh>  bruin.  Tho  iMveral  methods  aeree  in  ahnwing  that  incrcaaed  general 
arterial  pr^^Mure.  Mich  as  that  fir  instance  indiicol  by  NtimulHtion  of  a 
•enitory  ntrrc,  leada  Iu  a  gnmier  How  of  blocul  to  the  bniin  ;  the  vnlume  of 
tbc  bmin  in  increawd  and  the  vcaoiin  outflow  by  the  lateral  linus  U 
(lutckencd.  Oinvervly,  a  lowcriiig  of  artt'rinl  prctturc  leads  to  a  le«cne(l 
flow  of  blood  to  thi'  brain. 

Seeing  that  thi-  ccrfbrni  arteries  have  wolMevelo|X!<l  iniiicular  coals,  the 
bcwilar  artery-  in  fact  l>eing  ci>niiptcuouii  in  this  rrspect,  one  would  be  led  to 
suppofc  that  th«  hrnin  pnewnseil  snccinl  vaj>om«tor  norrrs  of  its  own  ;  and 
racogaixing  the  importance  of  Mima-supply  to  rapid  functional  activitv  niw 
wouM  perhaps  antidpnic  lh.it  by  special  vasomotor  action,  the  siii>p1y  of 
bl<M<l  to  this  or  that  particular  part  of  the  hrain  luighl  bo  rvpnlnml  apart 
from  changes  in  the  general  supply.  The  various  observation",  however, 
which  have  hitlierto  been  made  have  faile<l  to  demonatrate  vilh  certainty 
any  such  special  vnaomotor  nerves  or  fibres  directly  governing  cerebral 
vewels.  Ii  would  be  hazardous  to  insist  too  much  on  tliu  negative  result, 
especially  xiuce  the  obaervationa  have  been  chieHy  directed  to  the  nerves  of 
the  Deck,  the  exiierimental  difficulties  of  investigating  the  presenoe  of  vaso- 
motor fibres  in  the  cranial  niTvei  being  verv  grml.  Slill  tt  may  be  urged 
and  indeed  has  lieen  urged  that  the  flow  of  bluiKl  through  the  hrain  in  »o 
delicately  respotuivc  to  the  working  of  the  general  vasomotor  mechaniitm 
juKt  W-ause  it  has  no  vasomotor  ntTves  of  its  own.  In  such  an  organ  as 
the  kidiwy,  an  increase  of  geiwral  blond-praaure,  a*  we  have  more  than 
once  insisted,  may  or  mar  not  lejiil  to  a  jrKstcr  flow  through  the  kidney 
nccordinjc  a*  tlic  vtsMis  or  the  kiilnry  itsi-lf,  through  the  action  of  the  renal 
vitmmolor  nerves,  are  dihtol  or  c>n;«tnctcil;  and.  a*  we  have  Men,  a  ooil* 
•tridion  of  the  n'.nal  vrmiIs  may  be  one  of  the  conlributon  to  the  incTMsod 
genenit  priw^urc.  !u  the  hniin,  on  the  other  hand,  an  increase  of  general 
arterial  prwsure  seems  alwav*  to  lend  to  increase  of  flow.  Thus  in  the 
Traul>e>Henng  undiitattons  juxt  mentioned,  the  expansions  of  the  brain 
arc  coincident  with  the  rises  of  the  general  prcMurc,  whereas  in  the  normal 
kidney  and  in  other  organs  the  local  Traubo- ITcring  nn<hilat)on  reverses  tiui 
Kviieral  one,  the  slirinkings  are  synchronunn  with  the  rises  of  nreasurc,  the 
U>ca)  ooustriction  being  ona  of  the  factors  of  the  general  rise.  It  is  arguod, 
that  in  the  nlMcnoe  of  vasomotor  nerves  of  their  own,  the  cerebral  vessels 
are  wholly,  ro  to  sneak,  in  llie  hands  of  the  general  vasomotor  system,  so 
thsi  when  the  blooa-presaure  is  high  owing  to  a  large  vaso-eoiutrMtion  in 
the  abdominal  visoenti  more  blood  must  necessarily  poM  to  the  brain,  and 
when  aesin  the  bload-j>reasure  falls  ihroug^h  the  opening  of  the  splanchnic 
rtiMxt-galee  i,^  IT3)  lets  blooil  ncceasnrity  tlowa  along  tho  cerebral  vessels. 
And  indeed  one  may  recognise  here  a  sort  of  self  regulating  action ;  for 


THS   BRAiy. 


dimiiiif  hiiig  llw  Biippi}'  "f  blcmi)  to  cite  viuriniiftor  ■.■rntro  in  ttie  bulb  mdf,  m 
we  kooK,  UBA  powerful  Hiinniliii  in  [producing  va*<>-c<>ii»lnchiiii,wi<l  m  1m4i 
to  a  rieo  nf  blnotl-pn-murv  ;  but  Uim  very  rwv  of  blixxl'pmwura  drirot  ni'iii 
blood  to  th^  binin,  including  tbc  bulb,  und  thit*  the  injtiriout  «fliBct«tatU 
brain  thrcdicnpd  bj:  un  ana'niic  conditioD  are  wnrdcil  uB'  by  the  vtry  br 
Kinnine  of  the  niin-mm  itself.  All  (hive  ndviint«gc#  are.  bnwevtr,  <)ail« 
compatible  wilh  the  cik-x  isle  lire  of  >>p(rcial  vnsixiKitnr  mrrtmniNfUH. 

S  708.  Moreover  the  Hrjv,-  of  lilood  to,  iii)d  eoDMSiuent  ehangc  iD  tfae  Iwlk 
nf,  the  braiu,  ninl  iiid<-eil  the  tlow  of  IiIo'mI  l)iri>U);)i  the  brain,  br  iDcanrfd 
by  the  ventwe  outfluw.  inny  Iw  modifird  iinlejK-ndenlty  of  chaugr*  in  i1m 
general  blood-prcwiire.  For  iiii^tiince,  i-limiiltHiiMi  of  ihe  motor  n^-a  of  tli» 
oOJtex  (juickcn?  the  vetioiiB  uulfliivr,  without  jirocliieing  nnr  ninrkcil  chaitp 
in  thegenemi  IiIinHl-prenure:  this  feature  becomes  vcr)- (inking  at  thr  efutl 
nf  epilepliform  conviilsione  when  these  tiinko  their  appearance.  It  n  difi 
cult  not  Id  connect  iuch  a  result  of  functional  activity  with  some  special 
vasomotor  nrrvmi»  arr]iu)jeii>ei)t  comparable  to  that  so  obvious  ia  the  rtM 
of  a  secreling  k'""''-  A^aiii,  it  has  oeen  observed  that  eertnin  drug«  lian 
an  elfect  on  the  volume  of  ihe  brain,  'luile  incomincnsiiratc  with  ib^r  ei&d 
on  ihe  vasomotor  eyrtem  ;  thus  in  juirlienliir  the  iujectioii  into  the  ^DetiJ 
liIiHiil  stream  (if  a  weak  acid  |iroduce8  a  large  and  immediate  espaosioa  4 
the  brain,  while  the  introduction  of  a  weak  alkali  siniilarty  givea  rin  t* 
similar  considerable  ehnuking.  It  isHUggeeted  that  tlieseeffeetfi  are  pradwod 
by  the  acid  or  alkali  ncling  directly  on  the  muscular  ooals  uf  the  mioiiu 
arteries  and  ao  leading  to  relaxaliou  or  contraction  respectively.  In  treaiiiu 
of  the  chemistry  of  iiervuus  substance  (ST2)  wo  slated  thai  "  ibe  ptf 
matter  of  tlie  central  nervous  sysiein  is  snid  to  be  ali|;hlly  acid  durioflift 
niid  to  become  im)re  acid  alter  death."  lieceni  observations  gi>  to  »\h*9  tbt 
tiM!  gray  matter  of  ihe  cnrtex  in  faintly  alkaline  diirin/  life  and  unHrr 
normal  (iinditioiiii.  hut  beconieti  acid  alter  dcatli  or  wbni  its  l>loi'<|.*u|ifIy  ii 
interfered  with  ;  and  it  hiu  Wn  urgi-d  that  nerrous  gray  mailer  like  mm- 
culnr  siihslance  tlevulii[H  acidity  during  ncttvity,  a*  well  a*  upon  death,  tk 
acidity  bciug  pnibably  dui'  in  uic-li  cam;  l«  Mime  form  of  lactic  Ocid,  AimI 
just  as  it  bm  been  xuggMtiil  that  the  dilation  of  the  miniil«  artefitiaf  a 
skeletal  muscle,  accomimnying  or  f  illowini;  the  contraction  of  ibe  ffiiHtlfb 
is  btQUgbt  about  by  the'  acid  gcneralcil  during  the  coDtractioii  eannf  i 
rel«xation  of  the  uuis<:ular  ojals  of  (hi;  minute  arteries,  so  it  has  been  tap 
gated  that  a  (imilnr  aiidity,  the  product  of  nervous  aciivitv,  similarly  ]nm 
in  nervous  tissue  to  n  dilation  of  the  veiKels  of  the  part,  'flie  exbteace  «f 
special  vasomotor  mechanisms  would,  bowevcr,  afl^rd  a  more  BBlbbdOTy 
explanation  uf  these  and  other  phenomena ;  in  sjtite  of  the  negative  radu 
m  far  obtained,  the  matter  is  obviously  one  needing  further  invesiigalitA 
Meanwhilewc  bare  abundant  evidence  that,  however  bn^Uf-ht  about,  tW 
tlow  of  blood  through  the  broin,  and  probably  through  particular  pnntnf 
[be  brain,  is  varied  in  acconlanco  with  the  needs  of  the  brain  itaelf  himI  tW 
cvcnl6  taking  place  elsewhere  in  the  body. 


CHAPTER  III. 


eiOHT. 


{Phytiolayieai  AnnUimy  of  the  Eye. 

Tdr  «jelMll  is  of  ft  •plierol<)iil  itini>e.  1(  ci)ii>>!h(«  of  two  ■Mmentl 
(lidtt«Dl-m»(l  apbtTML  The  Inr^r  M-Knit'tit  is  »ituiile<l  poateriQrIjr,  mmI 
coitititiitn  nbrMit  fivcitisihit  of  the  wntls  <if  ihv  <>vciliull.  Prom  its  frM 
margin  prujccb'  thv  samllcr  »cgmci)t,  whicli  i*  llint  ni  ti  Kmuller  xfihort.  Thu 
puatarior  wgment  b  oompond  of  a  urbitish,  i}|iui(ue,  firm  wall,  cuMi»liog  uf 


FM.aa. 


Ita.»a 


nn.311— INxuBUi  or  1  llaiiiMWTti.  StcnuforTitt  Rviaiii.  n. iiuwi or ■ctimUc tutt :  d.Vht 
mnta :  a.  mfdntlo  M  chomlltl  c«i  i  ■.  dlUtr  UvuMiit .  i.  'iiUry  iiiwiai  -.  t.  «ilt*r<r  niu*rl«,  and 
/.  ifit;  (.  iBDoiMai«(i*aiia,o(iMl9iiiMiawiiht)Mo;>UcnDTv«|jablnd,  wlUtkAtrklvv'^Mda  U: 
p.lM>j  LBMptiMnr  llMiiwDl  a<  tba  Im*:  K  vlucoui  boilf ;  h,  bralitd  mcaibfwM!  t,  ftmmiM 
abBBlMi  «.<miulirfPM><:  r.ilntvclwalMUUIdli:  iD|«la  Banc  Iki  douri  lUw  IhfiNicb  Om 
•MiM  to  Um  kofllBitla^  ■>»  nr  Ih*  tall. 

Pio.  lU.— TniMUb  SacnoM  or  TUK  Dmku.  a  P*op*(  Ubus  of  iba  conMa:  Jl,*nia*i«r  (tuUa 
taml^of  ooreflk,  wllh  IMha  ooDlnncllTat  apHlMUiun  on  It;  C  <>Wlquaabna(i»m  II  lollw  I»)«h 
o((b««(nMB:  X.  p»H><M  «lMtla  Unim.  wllh  r,  tfilUMUiiaaa  ItoTtlM  membaaa of  Dononn : 
9.  Hutee  Tl*w  of  Uw  •pliboUvDi  of  lit*  mtmbruio  4f  Dvidmu. 

three  watt  or  (tiHtei — llie  itlrrniie,  the  ehoroul,  aiul  retina.  The  nntcrior 
•egmmt  u  coDtinuouR  with  tlip  lolerolio  coat.  ( Fig.  212.)  It  it  a  trmiispnivnt, 
•iHlic,  *»QV«x  ufK^n,  called  tlve  «>r«M.  The  cornc*  OOfUiM  of  ihrw  Inrera 
— an  ftnurior  ami  pueterior  eliutk  lauJaa.  hnritie  h«(w««n  lh«m  ft  tarer 
which  i«  the  pro]>er  lusue  of  lh«  or(^.    Tliia  niitFiDc  hiycr  is  oompoeed  of 


8I0HT. 


Fl.j   JH. 


about  sixty  siipenrnpo^cl  tnniinii*  of  funfdrni  fibroim  ocIIr.  In  flic  intCMlod 
between  the  Inminn;  nrc  tViiini]  tubular  »jia<Mfi,  wliicli  contain  a  inuMmmi 
fluid.  Tbeanteriur  nnd  noitcrior  citulic  lnmiiimnn?siriiclun-IrM  anil  nigU; 
elutic.  When  Kptiratell  fmni  the  gimiMT  eornc«l  liiMie  thev  haw  k  gnM 
lendcney  to  curl  up.  Tlii]>  fact  siiggota  that  ihme  two  laminie  an>  aotin 
n^nts  in  th«  retention  of  a  [imper  cnrrnlurc  of  the  cornn.  The  oonMa  » 
covered  on  ile  anterior  surfaee  by  the  onjiinclivnl  mnrwii  mem brnne.  which 
consists  of  three  or  four  layers  of  )>nvonicnt  epithelinm  c«>ll«:  llt<>  deoper 
layers  of  cells  are  obtont;.  and  placed  per  pen  ilicii  la  Hy.  (Fij;.  'Jl.'l.)  TSt 
conjunctiva  at  this  point  has  no  perraptinle  bnsemenClMinbraiM.  The  p>«- 
letior  Btirface  of  llie  cornea  is  covered  hy  a  traiMparaQt  HfOilS  ntetnbraBC, 
wbicb  conaisU  of  a  simple  layer  of  iKily^imal  pavement  epitbeliunt  oclb  iw- 

iiig  on  an  etat>tic  memhrane.  This  is  tallH 
the  membrane  of  Demoura.  Tlie  mrori 
has  DO  blootlveesels,  and  tlierefure  dentroi 
itflniilrinietit  by  diiriist<Ki. 

The  fi-lernfie  roril  is  M>  naniH  n«  accom 
of  the  Hnimnis  of  iu  texture  ami  h»r<liiCK 
II  forms  the  outer  tunic  uf  the  p(»iifMr 
Mgnieiil.  It  i*  whiiwh,  opn(|ue,  #mii4l, 
excepting  nt  the  poinia  of  aitacbmrat  J 
the  nitiiulc*  of  the  eyeball.  It  U  comfwnj 
of  white  (ibraua  tinue,  arranged  tarwr  v 
luM  in  bundle*,  which  interlace  each  mW 
in  various  din-ctioDS.  Anienorly  the  iai» 
lacomenta  are  in  n  cenemi  tr:in»vcr8odin^ 
tiou;  pwteriorly  t^e  dinrvtion  is  lonciM- 
dinnl.  This  coat  also  coniaira  tcIIov 
elastic  fibres  and  fuufum]  nuclealed  (elk 
It  is  ranttniiouB  anteriorly  with  the  eoiiHi. 
and  posteriorly  nith  the  perinvnriiimoflke 
optic  ner\'e.  Ac  the  iutemat  border  of  tke 
junction  with  the  oonieu  \*  a  vrnuui  (inn 
called  the  lima di*uiariA  iruU*  uttwuUM 
Sehlenuii.  The  ojtitc  iterve  ptcrcn  it  aUiui 
2.6  mm.  internal  to  the  an tero- poster! or  axis  of  the  eyeball.  At  tbit  poiat 
the  ooat  is  perforated  by  minute  o^nings  for  the  mmig«  of  lb*  ntn^ 
ftlaments.  One  nf  tliese  openintts,  which  iit  relatively  large,  gira  MMi^la 
tbe  arfTui  eentralu  refina.  Surrounding  thin  point  of  eninocc  of  tba  ufrik 
serve  are  many  small  opiiiugs  fiir  the  poMnge  of  tbe  ciliary  ncrvnuJ 
TCMels.  The  intenial  surface  of  the  nt-Ieru  cniiuioa  mhid  pigment  granalaL 
It  i»  setiamieil  fV»m  th«  tJwnnd  coat  by  a  dolicalc  flocculcnt  cellular  tiamr, 
called  the  Inmini  Jfuea. 

The  tharuiii  coat  i«  a  vaitciilar  menihrunc  containing  some  pigmenl-vcraniilet- 
The  cxt<Tn»l  portion  ix  omipHW^I  printipnlly  of  bloodvesMb  and  nervH, 
Between  the  vt-wfcli^ure  found  niiniurous  xlcllale  pigmcat-cells.  which  furBia 
fibrous  network.  Th"  interniil  ourlacc.  where  it  is  adjoined  to  the  pigmeM 
layer  of  the  retina,  atif)  conlaiux  pigniont-cells.  I'oateriorly  it  is  pierwd  b^ 
the  optic  ucrve ;  anteriorlv  it  is  conlioiious  nith  the  ciliary  proceaMe,  and  M 
separated  from  the  sclerotic  coat  by  the  cilinrii  mtuele. 

The  cii'tanj  f/roceurf  are  iirrnnged  in  the  form  of  a  ring.  Tbey  oooakt  ef 
about  sixty  to  eigblv  somewhat  conical 'Shaped  bo<lie»,  situate  with  their 
bases  internally,  (^'g-  •U)  They  are  plaoetl  posterior  to  the  tru.nnd  an 
ailaehed  by  their  tliicKened  or  internal  extremities  to  t]tenM/lefuor]r^'JrltMea' 
of  tbe  IcDB. 


Imm  Viiw  «r  the  Kuuhtt  or  thi 
Cmanni  Otur  wmi  m  ciumv  Piio- 

CBMS.  IMD  m  Kll-K  OF  TIIK  IHM 

It.  >D(«nor  plMD  of  lb«  chnrali)  ecu: 
A.  cIlliiTy  |irae—L'i:  c,  irU;  d.  >|ililMdrf 
nf  tlie  pupil :  (.  bantllaof  niimior  Uic 
aOklurof  (boimpll- 


PHT8IOL00ICAL   AN'ATOUY   OF  THE   KTB. 


8S9 


THc  Oi/iary  mvtcU  ari«r«  from  the  pniul  i>f  juiictinii  of  lh«  •clemlic  eont 
and  th«  mrntw.     Il  c>iii>i»(s  of  two  givniiinf — r  nilinliiig  or  immdioiial,  and 
s  cin-oliir  larrr.     The  rnilintii));  fnsdouli  Mrc  ntiwtwl  vzt«mnlly,  umI  linve  n 
riiliuual  (lirvrliuii.    I  Fig.  '21-5.)    Froai  thia  Imytr  nunwrouff  laxciculi  iiiter- 


Ptn  ;iv 


\.V 


I 


Samoa  of  thi  Quoy  lltatoii  or  ink  In  ix  Htt>. 

a,  mriMloiMl  niarliMr  bclcull or  I1»  miuruloi  MHani:  b.dcfptT'Nalnt  mtlolnt  flurliull : 

t,  t.  r.  aauulu  |it*xiu :  d  aanulitr  miurte  of  Mulla  ;  /  mtHriilnr  lamina  on  It)*  [•■lerlur  rarlVru 

«rilm  Ittn;  a,  miuriiliiTiiU-iaiiiihodllkrr  honUror  lti*tni^  r.  ■nnulnr  (WHlou  r>r  IIiu  riiiiOuIui 

MliarM.  K  ll(aiiien(uni  peciIuaiiiDi. 

Ince  betwcvn  the  fnsciciili  of  the  circulnr  layer,  which  occupies  nn  iiitoninl 
poeiliofi  to  the  mdintin;;  layer.  The  ciliary  niiiacle  ii  inserted  into  the 
CXlrrDal  Hirfuce  »f  the  aDterior  portion  of  the  'cli<inii<l  cimt.  the  tibn-«  cxtfiid- 
ioj  Minewlint  p"«leiior  to  I  he  aitierior  ii>ai){>t)  "f  thi-  retina.  This  inuiflc  i* 
•  rery  imporlnnt  factor  id  itie  mectianiaiu  o(  Bccotntnudiition. 


no.  ■a*. 


i^ 


MocvLtm  nRiH-rrsK  or  mi  I«M  or  a  vriim  Riawr. 
d^VHanuirf  ilMpu)iU:  b.  a,  laduuiif  ftadruU  ol  dllatw  iniwole;  c,  c,  enaimltaa  umbc  u-IUi 

The  rri*  is  •  fibromiifculur  curljiii)  whtcb  is  auipended  bct«-c«D  tbc 
comcn  iinil  the  criKtalliixt  l«n«.  It  ia  attnclH^  by  lla  dminiH-TVnuc  to  (he 
ititenial  vaU  af  lh«  > imi»  c.  iridMi  Id  It*  eenire  u  n  ri>u»il  |icrf<irali<>n  nilln) 
(Im-  puj>il,  which  i"  ■uwcptiHIe  of  n>(i>titeml>l<-  vuriali'>ti«  |a  sIm,  Thi*  nii-m- 
braiiv  IB  cx>i»|iow(l  of  >  fibrv  cuuncvlivi-  tmuv  having  •  gtntnil  rnilifttJa 


8I0BT. 


no.  SIT. 


direction  ttnm  tbe  pnpilliiry  b(ml«r.  Wiltiin  ihia  tissue  are  fuund  pigRif^t- 
relh  ati<]  unstnnlecl  niuecular  liaBue^  Tlie  niui«<ilar-lMiti«  eiraitiil  r>ria*iiU 
of  rtitUnting  hdiI  piradar  fasciculi.  'Fif!.  216.)  Tbe  firenhir  fiucieuli  fnna 
a  Bpbitioter  nl  the  [iii|iillary  margin;  the  miliaiini;  faMrit-uH  radiatp  frnn 
the  B)ibiiict«r  m  tbe  circumference.  Ai  llie  drrumfereuce  of  tbe  irialbt 
■□einbmi)e  lining  tbe  anlvrlor  chamber  form«  6brous  pfxic«wee.  which  ai* 
teniictl  thv  li'jiimtnlum  iridi*  ftectuuilum.  Tb«  puMerior  wirfaoe  ii  <»ren4 
vith  a  pij^iiL'iilary  layer,  wbicli  is  a  oonlinuatton  of  the  pigment  layer  of 
Uk'  rvlinu. 

Tbc!  retina  or  third  coat  cniuiata  of  two  [tnrtioiu;  the  plfcmenlary  man- 
bniiM-  anil  lerminal  elunn-nU  nf  tlia  optic  nervr.  The  pigmeittnrif  Ufnknmt 
or  Kiterniif  layer,  which  ba*  Imwii  ralleil  tbe  system  nf  tbe  unki.  coven  tha 
whole  of  tbe  internal  durfuiv  cif  the  dliary  prnciixes.  ibciriii,  aoH  tlH>chura(4i 
It  consbtF  of  a  eitiiftc  layrr  of  hcxnji^inat  nuclfnieil  pi^nwnt-ix-ll*  (Fie.  -I') 
of  a  dark-browii  cohir.  From  the  internal  siirfuciMtf  thinmrnihranctWltaiM 
fibrw  arc  oonlinuc)  bctwi'pii  the  cellular  dcmi-nU  of  the  itcrvnuii  layor.  It 
is  fmqueRtJY  diMeclod  with  the  choroid  coat,  and  »{>nk«n  uf  a»  kd*  iif  ill 
Umiiw.  1^  color  of  thn  iriit  in  rlifTcrent  imiividuals  i*  ih-pcndirnt  ii|nD  iW 
derwity  of  the  fibro-ttmnwtivo  tiwuc  Bntcrii)r  lo  ihc  myvi,  and  to  thr  anionni 
of  pi}.'ment  gmniilci*  in  it.  In  pcr«oni>  with  dark  eye«  lb«  pigment  ia  lUi 
tiB>(ie  ia  relatively  murv  abuDdaiit. 

Tbe  iiitrntitl  or  nmwu  layer  of  the  retina  it  cnmptved  ea«entially  of  Ik 
terminal  nerve  eloiueots  of  the  optic  nerve.     Bxiernally  it  ie  corereJ  with 

the  pigmentary  layer;  internally,  it  ia  lined  hy 
A  hoinoceDeoUB  tranaparenl  Blructurv  callnl  IM 
htfolotd  membrane.  The  Mruclure  uf  llie  reliu 
ia  one  of  great  ci-uiplexity.  It  conaists  of  nbc 
diKliact  layers  M'.wn  of  whi<;h  are  layen  of 
nerve  elenenlti.  .\11  of  the*  layera  are  bouai) 
toK^lher  and  »iippiiried  by  a  eonnoctlvo  tiwui 
which  contaiuN  blood vi-itvl*.  Thi»  layer  exttwb 
from  the  entranoc  of  the  oittic  »i>rvc  In  a  poiai 
where  the  aiinidRr  famHciili  of  tbe  ciliary  iniif 
clenrefoiiDil ;  at  this  point  tbe  nervoiiaclenwiib 
ocaac  to  exist,  nud  the  layer  bna  an  irrr^lw 
dcntalcil  margin  railed  the  vra  t.rmUt.  iteyqnd 
thi^,  the  nervous  layer  i«  coniinued  as  a  mtn 
librriu)'  exlenuBlion. 

The  optic  nerve  piorcM  the  sclenHi'c  and  lit 
choroid  coats,  and  ine  pii^rneiilary  meinbranoif 
the  reliDa.  when  it  rapidly  divides  into  iMl 
numbera  of  fibree,  which  conaisl  alane  uf  llx 
axisMjylinders  or  their  ultiiDBte  fibrillie.  Tbit 
layer  of  fibres  is  continuous  over  nearly  tk* 
wliiile  of  the  internal  surface,  and  ia  called  tbt 
ffcand  or  oplie  iierve-Jibre  hi/er.  On  ttd  inlerwl 
aurface,  between  it  and  the  byaloiil  membrane,  a  a  delicate  Mructure  callid 
tbe  firtt  layer,  or  mrmhrana  limilaii*  inlerna.  Tbe  Oiird  or  ffonglion  lofm  It 
oompoied  of  multipolar  ganglion  cctl*.  itimilnr  to  thoae  found  in  tbe  cerehnl 
•uhManoe.  Id  the  [loiitvnor  portion  of  the  retina  these  ganj^lion  celln  art  in 
flereral  layen ;  at  tlic  mnriila  tulea  there  are  at  many  aa  eight,  and  at  tbt 
anterior  portion  of  the  nlinn  I  here  is  but  a  Kingte  layer.  From  each  iif  ibCK 
cells  tifarea  are  cuntiniicl  li>  llic  fifl^  or  uiternit/  ffntnulr.  liii)tr,  which  eonntt 
of  granular  cellii  with  nucl'-i.  nHwcen  the  thiril  and  lifth  layers  ia  a  lam 
of  veaienUr  nmttvr  containing  iicrve-lihrils  of  extreme  minulenes.    tVa 


r«aHit>rT-<au«  or  nii  Ktiaiiu., 

iKOLUKKII.) 
A,  immincd  pl(iiicnl.<iBlk  of  Itic 
<4ia<ilil  runt;  K.  fr>iiit  tivii  of  tliv 
hgHWIPFIfc*  QollJiof  tho  lAgmKnuiry 
iiMOibniio. 


rOTSIOLOOICAL    ANATOHT   OF   THE    KYE. 


en 


b  the  fourth  or  inl«nial  ^ranulaUii  or  mo/<-rn/<ir  hi/rr.  Tti<-  liilh  or 
rxtrrii'il  yranutiiltil  or  i>w/wii/ar /oyer  uouista  itl'  |>nriillcl  inU'cliived  lilinv, 
ootiliiiiiini:  nuclei  miH  stuonth  cell*.  TW  MirritfA  »r  extrrnai  iiniinilt  Imtr  il 
r*rr  aimiliir  lo  llioyi/lA.  The  n'jrAfA  luyer  o>inRi#t»  of  n  •.lelicnlo  ntctnbimDe 
>»f  vi>nDecliT9  ti»u«,  called  lh<:  mtmbrnHa  UmiOxn*  ejtfrna.  The  iii'h'A  or 
biidllury  lajwr,  or  ftij^r  <>f  rid*  aoi)  coNm.  or  Jae«b't  mrmbrauf,  is  mniputcl 
of  Iwo  etomenla,  ibe  roj*  nod  conr*.    The  roU«  are  cvlindricul  hudies,  cHch 


Flo.  :!I9. 


niLKD. 


i 


Tta.  tia,— OnoatHHjtiii'  KKnnccTji'moi  nr  tiib  OiiniBi-niiia  or  im  JCiaTx-nnitn  i*  TWt 
l;rmi.  l.  iDomliraDB  llmiiKU  inlema :  2.  ApUc  a«rr*-nbt«  laivr;  S.  ■>)'»  utiiUNlllolmll*:  I.  Ib- 
IkhmI  BTUiiilXtd  or  tnolfvular  Uyu :  \  liilonul  gritniilt  l*rtr ;  '•  astna&l  ■mnitlaWd  or  uiolvcsltr 
■■fcr:  T,  cxtaraal  rminlcUrtri  «i  mvaitiniiu  Uinlumcilertor;  >^  tHclIltir  Urcr.  or  Itfer  uf  rod* 

PMl.  tl».— Rob  nan  C^iwii  riuui  txk  Itcnx*  cv  M  *^.  [inwnrnl  In  o  tm  rrr  niu.  mliiUrai  ol 
pcnanteaeld  lodtow  tbt  diKlllmiioritionrlkn.  biiJ  ihc  iIKTitcih  koiihturibi  [nlpmkl  •(■«•»(. 
1%«  oalor  nsmentol  ilio  tmu  la  tm>li«4i  up  liilo  <tl>kji.  xblnb.  Iinwimr,  ar*  Ulll  wUwiWit  M  ono 
■■Mk*r;  slUit  taaauriht  ooiui  are  iMn  alMr  KnirhiLln.  tx  IIMDitluiielen.) 

FN.  aa.—DuaMim>UTK  RrpunoiTtRtHi  or  ms  CnsvBcnvi  Tmtk  er  nu  Rmi>*  i^  «uk 
sKiBmitMuilKHKirt.  TbwnuiabaneatiMinnille  tboMorUwnvtnlUyenodbvRaiMahoitn 
Inric  us 

rnding  cxicmnlly  in  a  truncated,  flattened  eitrcniity,  and  internully  as  an 
■llvnualiM]  GttiT,  which  probnbly  communieatw  vritb  the  de«|ter  lujer  of  ]:;nn- 
eiiitn  ovIU.  The  rones,  as  ibcir  names  indicate,  ure  o)iii<.'al-Bfaa|>ed  budies. 
VMch  ciiiisisla  nf  twu  jKirtions,  a  cmical  btxly  havin;>  prujeclinK  rroin  iU  ajwx 
A  rud  like  wgment,  ubich  sppeare  in  all  n«pecU  like  Ihe  ruda.  Tbis  kic- 
■Mot  is  callcathe  con«  rod.  Tlie  terniioal  eitrcinities  nf  llie  cone  rods  no 
not  extend  us  far  externally  hb  the  extremities  of  tb«  rods.  The  rods  and 
cones  have  been  demonstrsled  to  vrimiat  of  iwo  Kegmentg  ur  liniba,  which  are 
CMupoaed  of  filawents,  granular  matter,  and  uugloi. 


-1 


893 


SIOHT. 


Tli«  optic  nerve,  where  it  pierces  the  co*ls  of  the  eve,  projocl«  •)m««)M 
keyoDcl  the  Burfitce  of  the  reliiia,  as  a  ;>'i/)i//'i ;  here  ihe  «MBeDti&l  nern'<l(> 
ments  of  the  n-lina  nre  absent,  and  luminoua  raya  are  iinperocived  :  hnt*, 
it  is  i^alleiJ  the  blind  tpot.  About  'i.6  riiq.  external  to  the  point  of  eotnum 
of  the  optic  nerve,  and  in  the  exact  wntre  of  the  retinal  surfiice  correepoDil- 
in^  to  the  tmtero  puecerior  axis  of  the  e^ve,  ia  the  "  yellow  spot  of  SonitCT- 
riog"  OT  mtKula  lutti.  (I'tj;.  2'Jl.)  It  n  an  elliptieal-ahapetl  apot,  haran 
its  long  diameter  traiHverio.  In  the  nenire  of  the  macula  luie«  m  a  ilepfw- 
aiou  called  ihefmvi  e^ntralU.  At  thi.'>  iminl  the  nervous  layer  of  ll>e  niiu 
U  very  much  nKHlificd  in  ciimpiMiiitDn  or  the  dilferenl  Inin-Tn.  At  the  niBmb 
Itik-a  the  nervou*  layer  ia  much  thii^lccr  than  at  any  other  juart  of  the  in«in' 
braii«.     The  f^nglioU  ({/iini)  and  the  extcninl  Kraiiulatcd  (*itih)  arc  tlir 


Kio.  ai. 


Fid.  SZ2. 


rin  2S 


llRibndiiloiit.  >iiti«rp|imriil(il  byatisitlnit.  uid  In  Ita  mMJlclLiviUrlitinl   tto itw InMM  »<* H Oi 
iicnt.  Kith  lu  acciiiiiianiiiiic  lulerr.    (Aftor  Soxhriiiii  xn, ) 

Pio. m.— WtiiNKicD  VnmciLEiETiosoriMcRinaiiMlvned  (Nm  KoiuKKn).  *,  mlonMW 
■ppMMnw  of  the  ouicr  (urfai'tf  of  tba  rctlnii  am  Ilia  jrcltuw  iput,  hIicto  iIhi*  uc  oniT  pj—.l 
tppnuanni  of  liirr  n>(liu  imr  nm  fvllox  ipnl— a  ulncla  drcla  tX  rxli  BununiiiMBC  (UB  Sdw[« 
>pC**rinM  or  Ihu  ml'l-llpaf  Ibercllna,  n  iust  numticrar  rola  ■nrruiiuilloKAicti  ■•••.  In  aD  IM* 
Ditiins  IDC  lunpu  rliiii>  rapnsuiit  [li»  ouuia.  mul  Idu  •iiiuUvr  uiini  tbi  Mil  Moa  vnlvu*.  lUa 
Kl.ii^.l 

Fin  ::a.-~AKzritnncT(TKiHorniiL.tHiJ[XM  ji  Oahm^rd  Lna.   a.ikci»uc)«iB;b,« 
teniiiiiv 


RiMt  thiclc<'ricd.  The  ;;iin^]imi  layer  Ruiiitist<  of  six  or  e!;;hl  InmiiDO  of  eeUk 
Tin-  rod*  of  the  ninth  layer  nrr  absent,  and  nro  rcpUoed  bv  ocxie*.  In  th* 
f'lvnn  ftitti^ili»  the  inlcrnni  gnmulnlcd  (Joarlh),  the  inteniaf  grnuuli?  (Mi\ 
mid  the  optic  iicrvt-fibrc  (trcond),  nre  wantine.  The  gBiig1ii>n  ocll  (rtrn/^ 
thi!  external  gr«nitliited  (lizth),  and  the  external  granule  (mm->i(A)  lajronan 
incrc3iM-d  in  thickiic^a.  The  giLn^Uun  layer  of  oelU  in  the  fovea  eootbttif 
thrcv  laininn.  In  all  nortions  ot'tne  nervous  layer  the  nxlc  grMtly  pmUimfr 
nalc  in  number  aver  tne  codu,  exoepling  in  the  macula  lutes,  where  ihtj 
arc  entirely  absent.  The  retina  is  much  thicker  posteriorly,  becomiDp  thinner 
a*  it  ext«n<le  forward  ;  the  nervous  layer  gradually  disapitenring  in  the  dsic* 
rior  pnriiun  of  the  membrane. 

The  inloriur  of  the  eyeball  is  divided  into  two  portions  by  the  OfyaUlliM 
kiu  and  ite  aiupensory  ligament.  The  anterior  portion  ountaine  the  oftrnw 
humor,  the  [wwierior  contains  the  vitreoiu  body. 

The  fr'j'latline  lnu  meuiurea  about  7  mm.  in  transverse  diameter,  as4 
nlMHit  4  mm.  anleM-poiterior  diameter.  It  Is  a  transpArenl  biconvex  bi)dr, 
eomoirhnt  Aatletied  anleriorlr.  It  oonslsis  of  a  uunilier  of  ngmenb  whick 
radiate  from  llie  centre,  similar  lu  the  segments  uf  an  i>ran^.  TheM  Mf> 
ments  are  cnmpostHl  of  superimpoMd  laminae  of  varyinjir  density.  The  la-et 
BuperHcial  are  soil  and  gelationut;  the  deeper  ara  relatively  hard,  so  that 


ravsioLooiCAL  anatohv  or  tiik  f.vk. 


8D3 


I 


I 


I 


thev  furni  ■  kcnicl  or  ntKleua.  The  laminEe  arc  made  uji  of  parallel  fibres, 
niili  an  iiitilulnttng  ctnirw,  ihe  convesiti««  and  roDcavilieaul  ihc  nttjoiaitig 
fibita  filling  a<:curnlctv  miu  citch  iillier.  The  kiis  U  covered  with  n  cai^fiule 
eouiMiDg  ol*  H  Iniimjiiiretit,  eluatic,  frH),-iIe  lueinbrnue,  which  lins  a  icnOeucy 
Iti  cur)  U)>,  wilh  ill  I'sU-nuil  jiiirface  tuiifriuiiBt. 

thu  MUfpevM/rir  liytmrnl  of  the  U-ii-*  U  I'onDCil  br  a  conliituatioo  of  tliu 
hjralotd  iiii'tiibrnnc  irhk'h  lines  the  vilrcoti*  biidy.  The  hvataid  meinlirtine  is 
n  <k-lic«te  lniii*|'iirt'iit  Mriictiire  lituated  hclw«ea  the  vitKKtus  body  aiid  tueiu* 
brana  liiiiitan*  inlcrnn  of  ibc  rvliuu.  Il  i»  continued  lu  fri>iil  to  the  orn 
•rmi/'i.  wlierc  il  dtvidvt  into  two  In^'on.  The  jHinti'ri'ir  is  lUinched  Ui  ihc 
pc«I»rior  portion  of  th«  eti])tul«  of  the  I<;iik;  the  nnterior  [loriion  jcradunllv 
boeoRica  Ihickcr  a»  il  cxtendx  forwnnl  behind  the  cilimn,-  firocettiai,  and  u 
mtavhcd  to  the  atiU-riur  Burimcc  of  the  cufMule.  Thiv  thickciii'd  porti^u  of 
ibe  mnnbrane,  which  is  orrugatcd  where  il  haa  ailHcheil  the  ciliary  pro- 
coan,  h  ctillci)  Uic  I'mr  of  Zinn.  ThcM:  twu  hiycra  L-oiivtitiite  the  nuvjit'nwry 
ligamenL  Brtvrreti  Ihem  is  n  irinntnitar  capal,  wilh  il*  bune  ci)rtv«{<oiiitiug 
lu  the  cmlwlline  Iciis.     This  is  cnlksl  tho  cniitil  ol'  Pctil. 

The  ri'trro»»  bodi/  w  coDiaiiicd  wilhia  llic  cavity  Airmvd  by  lh«  hyaloid 
HMinbrane  and  the  posterior  siirfnce  of  th<.-  Iuhk.  It  coiwinU  ot'u  clear,  odor- 
len,  altKiniinotis  Hiiiil.  hitving  an  extremely  drlicnlc-  inlvrlMOnieiit  of  fibres 
extending  in  all  directik'iis  through  il.  Thi'^  tilire«  are  not  disCVTHible  in 
the  adult,  but  can  readily  be  seen  in  iho  fixtus. 

The  aqitam*  liumor  is  contained  within  the  spac«  formed  by  ihe  poslorior 
turface  of  the  cornea,  and  the  anterior  surface  of  the  lens.  The  space,  which 
b  divided  into  luo  chniubera  by  the  iris,  is  filled  wilh  n  clear,  colorless, 
limpid  fluid  conioing  uiline  and  pruteid  substances  in  solution,  This  Uuid 
CvDMilUlea  the  a^unuA  hujnor. 

The  anterior  external  portion  of  tlie  eyeball,  compritint;  the  surface  of  tlw 
cornea  and  about  6  or  8  mm.  of  the  sclerotic  coat,  is  covered  by  the  oonjunc- 
livnl  mucous  membrane.] 

A  my  of  light  falling  on  Ihe  retina  (tires  rise  to  what  we  cull  n  sensation 
of  light;  bul  in  order  that  diMinct  vi>:on  of  any  object  may  b«  gained,  nn 
iniugc  ol  the  object  niiiiit  be  funned  on  the  retina,  and  the  Iwltrr  define*!  ibu 
itiiu]je  the  niorti  dinlinct  will  be  the  vision.  Hence,  in  studying  the  pbyaiology 
of  vision,  our  firel  duly  is  to  examine  into  llie  arrungt-iiients  by  whicb  Inn 
formation  of  a  wlislintnry  ininge  on  ibe  retinn  i»  cHcictcd ;  ihc^  we  may 
call  brk-lly  the  ilioplric  merlumitims.  \Vu  shall  then  have  to  iu'juire  into 
the  laws  according  to  which  r«ys  of  light  impinging'  on  the  retina  give  rise 
to  sensory  impulfM,  and  those  according  lo  which  the  impulses  thus  gvncr- 
•ted  give  rise  in  lum  to  sensalionitL  Here  wc  rhall  n>mo  upon  ibtdithculty 
uf  distinguisbing  between  the  unconscious  or  |>hysical  an<l  the  consciuiis  or 
[»ychicai  liiclors.  And  we  shall  find  our  dilrieultin  increaae<l  by  iho  fact. 
iliai  in  ap)>c«ling  to  our  own  consciousness  ne  are  apt  to  full  into  error  by 
confuuniling  primary  and  direct  sensations  with  states  uf  consciousness  which 
are  producvd  by  the  wcAving  of  ihese  primary  scnMlions  with  other  opera- 
lioDs  of  the  central  nervous  system,  or.  in  fumiinr  language,  by  confounding 
what  we  see  with  what  wc  think  we  ace.  Thwe  two  things  we  will  hrictly 
ditilioguish  as  visual  sensations  and  visual  juilgmenls ;  and  we  shall  find  tlial 
both  in  TuioD  with  one  eye,  but  more  («|>eciAlly  in  binocular  vision,  viaun) 
judgnwnis  form  a  very  lai^fe  part  of  what  we  frc<iuenlly  epeak  of  as  our 
sight. 


894 


SIGHT. 


Dioptric  Milchaxisus. 

Tht  Formaiien  o/  fAc  Image. 

T1i«  eve  is  &  «inK>rn.  cotifieting  of  k  wrw«  of  Icnwe  mid  idpiIir  >m&gal 
ii)  a  (lark  chiimlicr,  the  iris  serving  ns  a  diophriigm  :  miil  llie  objret  nT  i1k 
OjitHLrnlos  It  tu  furm  on  the  reliiiu  a  rlialiiict  ininj^i^of  extcrual  •ihjei'ta.  Thai 
a  (liiiliiiL'l  iiimgp  le  I'trintd  on  the  rcliiia  may  )>e  a«cerlainci.l  by  iviiioi'ia|E  l^ 
Bclerutic  from  llic  bntk  of  on  pye,  nnd  |i>i>|{)ii)(  at  the  hindor  etirtaee  w  ibe 
IraiiBparenl  reliua  white  raye  of  light  jiroi^eediiig  fri>ni  nuy  external  objeci 
are  allowed  to  tall  on  ilie  coniea. 

A  dioptric  apparatus  in  its  simplest  form  cnoaista  uf  two  media  wparutj 
bjr  a  [spherical  i  aurfuee  ;  and  the  o|)iti-»l  propcrtia  of  such  an  a|>p«niut 
<lepend  iipoo  (I)  the  curvature  of  the  surface,  (2)  the  relative  refradin 
{Hiwer  of  the  media.  The  eve  cnnwsia  of  aevera]  media,  bounded  bj  mi 
lacee  which  are  approximately  apbcriail,  l>ut  of  diSereuL  curvature.  Tte 
turfacee  are  all  centred  on  a  line  called  the  optic  ttxit,  which  meeU  the  rctiu 
at  a  poiot  Boiueu'hat  above  and  to  ilie  inner  (naaal)  ride  of  the  fuven  rm- 
tralis.  In  pawinx  fruru  the  outer  surfnct-  of  the  ctrDea  to  tbe  rvtuu  ibr 
rnys  of  lii;ht  traver^  in  sucecMion  the  cimien,  the  aqueniu  humor,  the  Ua\ 
add  the  vitreous  humor.  Kefrnetion  tulte*  place  al  all  the  •urfaoe«  hmoA- 
ilig  ihrae  several  media,  but  pArliailarly  at  the  anterktr  Aurfwre  or  Ik 
<i>ri)ea,  and  at  bmh  the  nuterior  ao'l  juBlvrior  siirfnt^eti  nf  the  l<-aiL  i^iw* 
the  anieriur  ami  poslenur  !<iirfiioc«  i>l  ih<-  ("irnea  are  [innilli-l,  nr  very  noiIy 
(to,  tlie  rays  i>f  li^ht  would  snlTer  littli-  or  mi  ohaiige  of  dinn^iinn  in  piMii^ 
ihnMigb  the  i-driiua,  if  it  wt^re  bounded  <-u  linth  rUUr*  by  ihr  Knmr  mrdian. 
Tlw  direction  of  llie  riiy»  of  light  in  the  n<|U(.i>ufi  humor  iroiiM.  iherHbn, 
remain  the  Mimv  if  the  cornea  wvrc  iimdc  exceedingly  tbiii ;  if.  in  fiict.  in 
two  surliu'cn  wvn:  nindi-  into  one.  fonning  a  single  anterior  surface  to  ibt 
a^ucuiii>  humor ;  or,  nhich  comes  t^i  the  same  thing  in  the  end,  since  (be 
refractive  power  of  the  substance  of  llie  cornea  la  almost  exactly  the  nnM 
as  that  of  the  a<iucoui>  humor,  lite  rcfmction  at  the  poelerior  surface  of  the 
conKt)  may  l>e  ncclcclcd  altogether.  Tims  the  luo  surlaoes  of  the  curaea 
are  practically  rrtliiccd  to  on«.  I'he  lens  varies  in  density  in  dilfercut  partt, 
tlie  refractive  power  of  the  centrnl  [lorliona  being  (greater  than  ibal  uf  tke 
external  layers;  hut  tlie  refractive  ]>oiver  of  the  vhole  may,  with'iut  aay 
serious  error,  be  lueiimcd  to  be  uniform.  The  refractive  power  uf  the  rilmai 
humor  is  almost  exactly  the  same  aj)  that  of  the  aijueous  humor. 

Thus  the  apparently  complicated  natural  eye  may  be  simi>1il1i>d  into  a 
"diagrammatic  eye,"  in  which  the  refraciiiiK  surfaces  are  rwluct-cl  to  llint 
via. :  {I )  the  nnlerior  surface  of  the  cornea,  (2)  the  anterior  aurfaoe  uf  lii» 
le«9  separating  the  lens  from  the  aqueima  humor,  and  (3  f  the  poatvrinr  n^ 
face  of  the  lens  separating  the  lenii  fnim  the  vitreouB  humor.  The  medii 
will  similarly  be  reilucetl  to  two:  the  subslancfi  of  the  lens  and  thi'  a'luvMi 
or  vitreous  humor.  Tliia  "diagmmmatic  eye"  ia  of  {;reai  ute  in  the  VSTM 
calculations  which  become  neceat^iry  in  studying  physiolugicn)  nptlca:  fm 
the  macnitudea  which  are  derived  by  ailculation  from  it  n--|^>m>cn[  tlip  cut- 
reaponoing  magnitudes  in  an  avemge  natural  eye  with  Kuffirnni  accuracy  in 
•crve  for  all  practical  purpoM;*.  Tlie  vulum  adofHcd  hy  Ltsttntf  forth* 
onvtanis  of  tltis  "  diaRram malic  eye,"  and  to  him  we  are  iudubtcd  for  lb 
introduction  of  it,  are  oa  folluw : 


DIOPTBIO   MECnAMSXS. 


895 


I 


I 
I 


K*4ltu*  ot  curvature  of  coram 8  tttm. 

of  wurior  furrsoe  or  tea*  .  10    " 

of  poalerior     ■'  "  .        .        .  tt    " 

It«rnit1iv«index  oraquMiMor  vltrmua  boinor        .        ,        ■  W 

MfMii  rrrmciivc  index  of  len* Jf 

I'lsuni^o  rnmi  aotrriar  aurfncc  nf  comen  (o  aiili-fiur  ^nrfMH  of 

lens -I  mm. 

Thitknmsor  lena 4    " 

Tbe  culculute<l  poxilioii  nf  [he  principal  p/mterior  Jiteut,  i.e.,  the  {>oiiit  at 
which  all  nt}^  fulling  "■>  the  ooriiea  jwrnKel  lo  the  opiic  axU  an  brought  to 
sfiwutiU  ia  thetiiauruiiiiiiaiic  eve  14.ri4(i)  mm.  livbioU  tbe  |>t)iiierlor  Hurfiuw 
of  tlie  lens,  or  2'J.b4tO  miu.  behind  the  univrior  nurliue  of  tbe  cornea. 
That  i*  to  say,  tbe  fovea  i-etiiralb  iduu  occupy  thin  pusiiiun  m  onler  that  a 
•JiatiiK-t  iiDave  of  »  ilislant  uttjeet  may  be  fiiruir<)  ufioii  it.  It  mult  be 
URilemt)»tl  uinl  tbcwc  vulues  rvfer  to  the  eye  nhcii  at  reil,  t. c,  wh«n  U  b 
not  uudergoiiiK  any  utrain  of  ucrommutlatiuii. 

AeeanmoiiaUon. 

WhcD  an  object,  a  lens,  and  a  screen  lo  receive  the  iinege  are  bo  arranjretl 
ill  rel'erence  In  each  uther  that  tbe  iraajte  falln  upou  dm  vcreeit  in  esiiel 
r<icii9.  the  rays  ul'  \'\^\\\  proceeding  IVom  each  luminous  point  of  ihe  object 
an.-  hr»u]-ht  iiii»  f'n'us  nn  tbe  screen  in  a  |>uint  of  tbe  iina^  corre»]ninitiog 
til  tbe  [Hiint  of  (he  ubjeci.  If  the  object  he  then  remuvcd  further  uirrnv 
frutn  the  letis.  the  rayit  proceetliog  in  a  |>encil  from  each  luminou;!  |H>iHi  will 
b«  bn>ii)(hl  to  a  Ak-ua  ai  a  jHiint  in  front  of  the  Mcrveii,  and,  •uhni-igueDtly 
(Itverving,  will  &I1  u|>un  tlie  screen  at  u  circular  imtRh  ouoiiHveil  of  n  Mri^ 
of  ciivlcb.  the  to-called  difftttion  eirelai,  arraiiireil  cunccniricKllj  miind  the 
priiicijMil  rav  of  the  pencil.  If  the  object  be  removed,  not  further,  but 
neanr  the  ivtu,  the  pvocil  of  raya  will  meet  tlie  Krven  befur«  they  have 
bc«D  brvtight  to  fiicnn  in  a  {luiiit,  nmt  coiiwiiucntlv  trill  in  (hi?  n>«e  nIfO 
giv»  riM  to  tliR'ueion  rirclca.  When  an  object  i<  placed  before  the  eye.  so 
that  the  image  falls  into  exact  fucUH  on  the  rclitia,  and  the  pencil*  of  ravs 
proccrding  fnim  each  luminous  point  of  the  ohjcci  are  brought  into  focus 
iu  iNtinl*  on  the  rclina,  the  seiiiatioii  called  furlh  is  that  of  a  distinct  iniagv. 
When,  oil  the  contrary,  the  object  is  too  far  avay,  so  thnt  the  focus  lies  in 
front  of  tbe  retina,  or  Ion  near,  to  that  the  I'ocit^  liea  behind  the  retina,  and 
tbe  pencils  fall  on  the  retina  nut  at  |K)iDt«.  hut  as  syeteraBof  ditfiision  circleo, 
the  wiintioii  produced  is  ihac  of  an  indistinct  and  blurr«d  in^.  In  order 
that  objecU  both  near  and  distant  may  be  ^«eu  with  eqaal  ilutiueiueas  by 
the  tame  dioptric  apparalus,  the  focal  arrang«menla  of  ihe  anpoTUus  iDUat 
he  artommodaltti  to  the  dislaocc  of  Uie  object,  either  by  chaagiDi;  the  refVac- 
live  jMwer  of  Ihe  lens,  or  by  allcriDg  the  distance  between  the  lenv  and  tltc 
•creeu. 

I'liai  the  eye  does  pomeea  such  a  power  of  acconiuiodnti<Hi  i:*  sliown  by 
e%'ery-day  experience.  If  two  ne«<lles  be  lixe<l  upright  aunie  two  feet  or  •!> 
aMii  into  a  long  piece  of  wood,  and  the  wood  be  held  before  Ihe  eye  so  that 
the  Detdlei)  are  nearly  in  a  line,  it  will  be  found  ihat  if  aiteiiiioii  Iw  direvtcd 
lo  tlie  lar  needle,  ihe  uear  one  apf>eant  blurred  and  ijidiatinct,  and  tluU  cun- 
vciMtly,  11  hen  the  near  one  b  dblinct,  the  far  one  apiiMLni  blurred.  By  an 
effort  of  Ihe  will  we  can  at  pleaaure  make  either  the  lar  one  or  the  near  one 
diftincl ;  but  uoi  both  at  the  «ime  lime.  When  the  eye  b  anangcd  m  that 
Ihe  far  neolle  ajijieani  diatinct,  the  iuuige  of  that  needle  falls  exactly  on  tlw 
relimi,  and  ■■ach  pencil  frrmi  i-nch  luminuun  [lotnt  of  LIm  lieeille  unilei>  in  n 
point  u|>on  ihv  rctiiut;  but  wlten  this  is  tlte  chm  ibe  fociU  of  the  near  needle 


SIOBT. 


lies  beJiintt  lIu)  retina,  mxl  vncli  pencil  from  mch  tuminuut  )i»ini  <if  ihit 
needle  iitlla  upon  the  rerina  in  n  acrttx  or  itifTitflon  circles,  i^imiinrlr.  ohen 
tb«  eje  is  nrrangvd  so  th»t  tiiB  nuir  nrc<IIo  w  diMincC,  the  imaj^  uf  Uial 
Deedle  fulls  upon  the  reliiin  in  encli  a  way,  tbat  eacli  |iciicil  of  rnys  rrmn 
eAvh  luiuiaoUB  point  of  the  nccilk-  unites  in  a  point  on  the  retina,  wltili'  Mck 
pencil  I'roiu  encii  luii)ino<iH  |>oint  of  the  far  nec^lie  unites  at  a  pi'int  in  /nml 
of  llie  retina,  and  ibcu  divLTgin^f  attain  fdlls  on  ilie  retina  in  a  iteries  uT  dif 
fusion  circles.  It'  the  near  needle  be  (jradLisily  brought  nearer  and  nearer 
tu  the  eye,  it  will  lie  fuunil  that  greater  and  greater  etiort  is  re<)uin!d  to  tee 
it  diatinctlr.  nnd  at  hiel  a  jioiut  is  reached  at  vrhicli  nu  eObrt  c«U  nialie  tlie 
iaiai^e  of  ibe  needle  api>e.ii'  anvlliin<j  but  blurred.  Tli«  diDiance  of  ihit 
point  from  the  vye  murks  Ifie  timil  of  aeconiiuodaliiM 
riant.  for  near  ubjccie.     .Similurij-.  if  the  pentou  Im  short- 

eigliled,  the  far  needle  nmj  be  moved  aw&y  trwa  iIm 
eye,  unlit  a.  point  is  reaebed  nl  which  it  cemaet  lo  be 
seen  difltinctly.  and  apjiears  blurred.  In  tb«  ooe  cut 
the  eye,  with  all  it^  jHiner,  in  unable  to  briuj;  the  ItiMgc 
uf  the  needle  aulBcienily  forward  to  fall  on  the  reiin*; 
the  fucuH  lien  perinaucntly  l>vhiii<l  the  rt-tina.  Id  Ik* 
other  the  aye  cannot  bring  tliv  iuta^  ntiHicivnlly  haci- 
ward  to  fall  on  the  retina ;  lh«  focu»  lin  {rrtnaneatlf 
in  front  of  the  Ktina.  In  both  ca»ei<  the  [KuriU  uf  ra;( 
from  the  needlea  strilcc  the  retina  in  dilfu^ion  drelo. 

The  «ttnic  [ihenomena  may  Iw  ibowti  with  grcaicr 
nitety  by  what  iit  called  Hcbuiner'»  FIx|>orimmt.  If 
two  itnioDlb  hotf«  1)0  pricknl  in  a  card,  at  a  diatowr 
from  cJich  otlKT  Icsx  than  the  diouKtcr  of  the  pu]iil, 
and  the  card  be  held  up  before  one  eye.  with  the  hula 
horizontal,  and  a  needle  jilaccd  vertically  be  looked  M 
tlirough  the  holes,  the  fullovrin)*  facts  may  be  ufai«mi): 
When  attention  is  directed  lo  the  needle  itself,  the  iau|e 
of  the  needle  appenre  sii));le.  Whenever  the  gue  » 
directed  to  a  inure  diKtanl  object,  so  that  tlw  eyu  it  m 
luDjter  accommodated  for  the  needle,  the  iningv  uppMii 
double  and  at  the  same  time  blurred.  It  nl»u  spjmn 
double  and  blurred  when  the  eye  is  accumiiiodatvit  for 
a  distance  nearer  than  that  of  Ute  iieedli'.  When  unly 
one  needle  is  seen,  and  the  eye  lliervfore  in  pnjpcHy  b» 
comimiduled  fur  the  diniauce  of  the  nceiilv,  no  wlMit  it 
produced  by  blockinic  U]>  one  hole  of  the  card,  rxocpt 
that  the  whole  Held  of  vision  ieetna  diiumvr.  Wbcii, 
however,  the  image  is  double  oii  nccount  of  tb«  rre  be- 
ing acciKiiaKidated  for  a  divtanee  grtMer  than  that  i4 
the  needle,  blocking  the  left-hand  hole  vauen  a  d'mf- 
pearoiice  of  the  righl-bund  or  opjHifilf  ima);e,  vul 
blocking  tbo  right  hand  bohr  niiiiea  the  lell-lniml  imiigt'  to  diMipfx-ar.  \Vb<u 
the  eye  it  aoconimodated  lor  n  divtanco  nenrrj  than  thiit  of  ihv  needle,  block- 
ing cither  hole  causes  the  iningo  nn  the  nmo  udv  «i  \'nnisli.  'flte  aitoK 
dingrsiii  "ill  explain  how  time  results  ara  brought  nbouL 

Let  u( Fig.  '2'Hf  be  a  Inniinnii*  point  in  tlte  nettllv.  and  »  r,  n/tJw  extreoM 
right-liand  and  led-hand  ray«  of  ihc  pencil  of  rays  proceeding  froni  ll,  and 
passing  resjiectively  tbrough  the  right-hand  e,  and  letl-liand  /,  boloa  In  llie 
oard.  (The  figure  ia  stimwtMd  to  be  a  burlsunlal  section  of  the  eye.)  Wbtn 
the  eye  b  accummodaieil  for  n,  the  rays  «  and  /  meet  together  in  the  |>o(di  ', 
UiD  rettDB  occujiying  tJi«  inwitiou  of  the  plane  x  n ;  llie  lumiuoiu  (wiut  a^ 


DuonAM  or  Hrnmiis'B 
ZxrauHot 


DIOPTRIC   MEOUAKISMS. 


807 


I 


pmn  w  nnr  iHiint,  Hill]  iliv  iwc(lt«  will  apiHtir  u  one  occdlo.  When  llio  ejro 
■>  MoMninoliilcxl  for  ■  ilinliinrc  be.vniiil  •!,  lln-  rottna  mny  bo  cuit>i<U'rfd  t»  Ire' 
no  Im^fCr  *l  n  n,  Ixit  iM-urvr  the  \iiu*,  nt  in  >n  for  cxitniplc:  the  mp  a  e  will 
Ml  th»  plftne  nt  p.  ami  Ihe  raj:*  a/Mif;  heDC«  tlio  luminous  point  will  no 
loDgtT  ft^i|H-iir  •iiiglu,  bill  will  In?  xnn  lu  tvco  poinbt,  or  rnihor  a*  twn  «vs[ein» 
cif  SitTiiHuii  circl««.  iiod  the  sin^to  iivetilv  will  iip[icnr  m  two  blurrvi]  dmhIIw. 
The  ray»  niu»ing  thr»ui;h  the  right-hniHl  hole  «,  will  cut  the  rvliun  at  » — iV.. 
oQ  ttto  rignt  hanil  »Mv  of  the  ojitii.-  axis ;  but,  u  ne  shnll  •«)  in  #|>oflKiiig  of 
(he  Judgtnontii  pFri«intiig  to  vuion,  the  imagtt  on  the  righl-hniiij  stdi;  of  the 
ntina  '»  rrjerral  kv  tht  mind  to  an  object  on  the  Icft-lintiil  lidc  of  the  dlt- 
•on;  bunco  the  attectiou  of  the  rt-tina  ut  p.  j>rtKluccd  by  the  nip  a  r  lulling 
Ml  it  tlirrv,  give*  riie  tii  nn  iinngc  of  the  sput  a  at  /',  and  »ii»ilarly  the  led* 
luind  »]Mit  7  corresponds  tu  the  right-hand  '/.  UWking  the  Ictt-haiid  hole, 
lhcrrfi>ri-,  caUMX  a  disnppcnrnnce  of  the  right-hand  tningv,  and  eier  verM, 
Sintiiarir.  when  the  eve  is  nccoinmoduled  for  a  distance  nearer  than  the 
OMdlt, la*  Klina  may  (k  8uppi«ed  to  be  removed  to  i  I,  and  Uw  right  hand  a  c 
■nd  teft-haiul  a  f  rays.  a(Wr  uniting  at  <r,  will  iliveryo  again,  ana  strike  thq 
retina  at  p'  and  '/.  '  Tiie  blucking  of  tbe  bole  e,  will  now  cause  the  disap- 
pearance of  the  image  ij'  on  the  Ifltl-band  aide  of  the  rvliua,  and  this  will  oe 
rererre<l  by  the  mind  to  the  righl-hund  aide,  so  thut  <^  will  seem  to  vanish. 

If  tbe  needle  l»e  bmughi  grmlually  Dearer  and  nearer  lo  tbe  eye.  a  point 
trill  be  reached  within  which  (he  image  b  alway*  double.  This  i>uinC  marks 
Willi  oooiiderable  exactitude  the  near  limit  «f  ac(»>miuo)}aliun.  With  aburt- 
eighted  [ler^ms.  if  the  needle  be  removed  further  and  further  away. n  point  is 
rMebed  lieyund  which  llie  image  ia  always  double;  Uils  marks  toe  litr  limit 
oT  Hooramodalion. 

The  experiment  may  also  be  |>erfurmed  with  the  needle  placed  boriiou tally. 
Id  vbich  case  the  hulcs  in  the  cnnl  «liuiild  bo  vorticnl. 

The  adjiutnictii  iif  the  oytj  for  near  or  fiir  diitancM  may  be  a«i»tml  by 
usinj;  two  necditm,  iintt  ueiir  and  one  liir.  In  this  case  one  needle  should  \h! 
vertical,  and  the  other  horiminlat,  and  the  cjinl  tnmoil  nund  so  tbnl  the 
ho)ca  lie  horixontally  or  vcrticnlly  according  to  wliethor  the  vcrii^ud  or 
hnHx»n<al  ncrdle  in  bring  mailo  l<>  appear  double, 

III  wlini  may  hv  regarded  iis  tbe  normal  eye.  the  so-called  emmHrapk  tvn 
[Fig.  fJO],  the  near  limit  of  accommodation  is  about  lU  or  Vi  cm.  and  the 


XHairiiunc  Sts.    FASAUit,  mi.n  ruiv«u  or  t«i  anal*.) 

far  I'lmil  may  be  put  for  practical  purposes  at  an  infinito  di#lancc.  [Fig. 
S'id.]  Tbe  "  range  of  distinct  vision."  therefore.  (<ir  the  emmetropic  eye  is 
very  great.  In  the  tnyopie,  or  short-sighted  eye  f  Fig.  '£"£7}  the  near  limit  Is 
bruuglit  much  closer  (5  or  0  cm.)  to  the  oomea ;  and  the  far  limit  is  at  a 
Tcriable.  but  not  very  great  distance,  so  that  the  rays  of  light  proceeding 
frofn  an  object  not  many  leet  away  are  brought  to  a  focus,  not  on  tbe  rfltiM. 


■  or«oufH.n  th»aoiiwi  tro.  «■  «r«  *t»tl  m*.  aamrnaalMMNt 
■■4  DMtTMialHnUniiaiWfaUtkmarilieMUtiai  Ht  IDr« 
|HM  tlM  IWIBB  to  M  monU. 

67 


.  tatiboud  lijackuiM  UthaWai. 
OMnataaM  «fcSb  *b  nsf  turn  lap- 


SIGHT. 


but  in  ibc  TitreouH  humor.  Tho  ran^  of  ilintiixit  virion  b,  tbc^^f^rp,  in  ih^ 
myopic  eye  wry  limiird.  lo  the  kgptnuriropie  IFig.  -IMIJ,  or  lonK-Nk'tilal 
eyv,  thv  rft)'H  or  tight  comiDg  from  cvtm  nti  infinite  ilisuincv  *re,  in  the  |m»- 
Rvo  BtAto  of  ifae  eye,  brought  to  a  IWcw  bpyood  the  mfoa.     Th«  nrar  hmit 


[Fm-sa 


DMmono  Etk.   Tbc  iloit4>d  lluo*  iliowliic  bow  HconuuvlKtJan  lut  iba  iUtmvI'C  bj*  i'  mv 

«t4«0titi«SkCiM] 

of  >ccmimo()utioo  is  «t  tnme  flistADcc  olf,  nm)  a  hr  liniil  of  nrcomimalAliM 
doff  not  exict.  The  pr^jiAijnyjiV  eye. or  tho  long  aight  ofohl  f<»plu,  nMild>hl 
tbc  hvp<Tiiii-trx>pic  eye  in  the  liistuiw  of  the  near  {xfiul  nl'  nn'ommndMioa 
but  dittvn  from  it  innnmuch  a*  the  former  i«  tai  w«cutially  defective  ooadi- 

ine.  m. 


m 


UVDiic  Rte.| 


lion  of  the  aocoRimodation  ine«hnniain,  vhereu  in  the  Inlt^r  the  povtrtf 
accumuodatioD  may  he  good,  and  yet,  flrom  (he  tnternal  arningemenis  itf  ll» 
eye,  be  unable  to  bring  the  iiuH^  of  a  new  object  on  to  tl»e  retina-  Wb« 
m  Dorcnal  eye  hecoiues  presbyopic-,  thu  fi>r  limit  may  remnin  the  Mtnc,  but 


llTrKHHimioric  Evi,] 

since  the  power  of  accommodating  for  near  nbiecta  is  traakened  or  loit,  tbt 
chaogtr  is  di*lincl)y  b  reduction  of  tho  r«0}^  of  disliuct  viiiun.  In  th»  Mr 
ma)  emmetropic  eye,  vihen  no  effort  of  accommodstion  b  nude,  the  priDei]Mt 
focus  of  the  eye  lite  on  the  retina,  in  the  myopic  eye  in  front  of  it.  and  ii 
the  hypermetropic  eye  behind  il. 

Mtthtnitm  of  atvommod'ttiein.  Id  directing  unr  aUeolion  from  a  fiir  Ua 
very  near  objeci,  we  arc  codecIous  of  a  ilii»[inct  eSbrt,  nod  fv«l  that  «0M 
change  has  taken  place  in  llie  eye;  when  we  turn  from  a  very  near  to  a  &' 
object,  if  we  are  cuoBcious  of  any  chanj^  id  iii«  eye^  it  m  one  of  a  diflfenni 
kind.  The  former  is  the  ien»c  of  aii  active  acoamawdatjan  for  near  otyetfi: 
the  LaUer,  when  it  b  felt,  is  the  seuse  of  relaxation  after  esortiou. 


DIOPTRIC  JtECHANISSra. 


899 


Siuct  the  fkr  liratl  <if  : 


I  <lislnnr«,  no  ituch 


r-ii)tiui(iYi|iic  v.yt  u  ii 
notivr  nrmmn) (Mint mil  llirfitnlii'tiiiu'cs  miil  viiNt.  The.  niily  chiingc 
ihat  will  liik^pliK'i-'iii  th«:  ovc  in  turning  rmni  nvjirtu  liiniliJMtswttl  lien  atvm 
|wiwvvui»daiDgortbcHCGODiiiiod«ti<in)>r«viou»tyiua*lvfortbcne«robjeicU  And 
Uikt  no  »ueh  Kotive  Mcomoiodation  Tor  fur  dbuuiM  tnkt*  jilaci-  in  tliown  t>v  the 
IkrU-tUftt  the  eve,  nhen  opened  nlUTlx-ingelosod  for  some  time, is  fount)  not 
in  mealium  Rinli.',  bitt  adjusted  for  illMnnc* ;  tbnt  when  ibo  aeoom modal iun 
n>n-liiini>m  "f  ihc  eve  i«  purnlrtnl  liy  lUropinr  or  ncrvou*  Hi»cnw,  the  acconi- 
ni<xliilii>ii  fur  (lii>iiiiit  objn-l!i  i#  iiniiHcr'Irfl ;  iind  llinl  v,c  «re  coiueious  of  do 
cflbrt  in  Itirning  from  m<Hl<-ralcly  ilisliint  («  for  ili«liint  objcrW,  The  senw 
of  effiin  ol^cn  «p<)ken  of  by  mvr>nic  pcnionB  a»  being  frit  when  tlwy  al- 
leni|)4  to  BM-  tilings  nt  or  bevnnJ  the  Inr  limit  of  their  range  teeniH  to  arise 
from  a  movcmeni  of  the  eyelid*,  and  not  from  aiij'  iiileniar  changM  taking 
place  in  the  eye. 

NVIint,  (lien,  are  the  changes  vrhieh  take  place  in  the  ere.  when  we  accom- 
nodnle  for  iK-nr  objeels?  It  niighl  lie  thought, nnil.inilced.onoowaa  thought 
thni  the  curvatures  of  the  eorne«  was  chnnged,  lH-i.iiming  more  convex,  with 
■  shorter  ivdius  of  curvaliire,  for  near  ohjeets.  Ynuiig.  however,  showed 
that  aotrom  modal  ion  took  place  as  usual  when  I  he  eve  (and  head)  is  immeraed 
ID  water.  Since  the  refractive  powerv  of  BC|UeoUB  liuntur  and  water  are  very 
nearly  alike,  the  cornea  with  its  parallel  surfaoee, placed  between  these  two 
fluids.  caD  have  little  or  no  effect  on  the  direction  of  the  rays  passing  ihruugli 
it  when  the  eye  is  immersed  in  water.  And  accurate  ineasuremeiitJi  of  the 
dimensions  of  an  image  on  the  oomea  have  shown  that  these  undergo  no 
change  during  aceoniinodation.  and  that  therefore  the  curvature  of  the 
coniea  is  »i>l  altered.  Nor  is  there  any  change  iu  the  form  of  the  bulb; 
for  any  variation  iu  this  would  necessarily  uroduce  an  alieratiuu  in  the 
curvature  of  the  cornva,  and  prtmurc  on  the  Dulb  would  act  iujunounl}-  by 
rendering  the  retina  ansemic  and  >0  leM  aeniitlve.  In  fact,  tbvm  an-  only 
iwo  cbangrw  of  ini|iorliince  which  can  he  nnccrtaiDcd  to  take  place  in  the 
eye  durin;;  nt-coriinioilniion  fur  near  objects. 

Our  i*  that  ih<-  iiuiiil  ['onlriii-ts.  Wlii-n  we  look  at  near  ol>jC4:l«,  the  pupil 
becunuw  sniBll ;  irlu-n  wc  turn  tn  djuiant  iilijvclf,  it  diliittv.  fhin,  hnwovvr, 
cannot  have  more  than  an  indirect  intluenoir  on  the  lormatiun  of  the  image ; 
the  chief  lue  of  the  contracltoii  of  the  pupil  in  nccomniodauon  for  near 
ubjecta  is  to  cut  olf  (he  more  divergent  circuralvrrntial  rnys  of  lighL 

Tbe  other  and  renlly  efficient  ehnnjn-  i«  that  the  anterior  surface  of  the 
lens  beramca  more  convex.  If  a  light  Iw  held  before  the  eye,  three  reflected 
iniagi-s  may,  with  care  and  under  pri>])er  [ireeautions,  be  seen  by  a  bystander; 
one  a  VL-ry  bright  one  cwused  hv  the  anterior  surface  of  the  cornea,  a  sevund 
Im>  bright,  by  tlie  anterior  surface  of  the  lens,  and  n  third  very  dim,  by  the 
posterior  eurlace  of  the  lens ;  when  the  imagM  arv  thusc  of  an  object,  such 
Bs  a  candle,  in  which  a  top  and  bottom  can  be  recogniKod,  the  two  former 
unages tre aeea  to  be  ereirt,  but  the  third  inverlerl.  Wbeulheeye  is  aecoiu- 
mwuMd  for  near  objects,  no  change  is  observed  in  either  tfae  first  or  the 
third  of  tliese  imagiM ;  but  the  second,  that  from  the  anterior  sur&ce  of  the 
lens,  ie  seen  to  Wcunie  dislinetly  smnller,  showing  that  the  surface  has  beoooie 
more  oiuvex,  When,  on  the  contrary,  vision  is  directed  from  near  to  far 
iibjects,  the  image  from  the  anterior  surface  of  the  lens  gron  larger,  indi- 
cating that  the  convexity  of  the  surface  ban  diminiebetT  while  no  change 
takea  place  in  the  nirvature  either  of  the  cornea  or  of  the  posterior  aurfaea 
of  the  lens.  And  aceumte  measurements  of  the  size  of  the  image  from  the 
anterior  surface  of  tite  leas  have  shown  that  the  varisUoos  iu  curvature 
which  do  take  place  are  an  flicient  toacoount  furthe  power  of  acoommodalion 
which  ike  eye  |) 


SIOIIT. 

Thsobavrvntionof  ttiMprvRccW  IihicmU  raci1ilal«d  bylbcalaiple  inftnimtnl 
Intrnducril  by  llclinhollx  iitid  cnlleU  «  phakotcopc.  It  comiata  of  a  pirhII,  ilifk 
i.'liiimti«r,  wiih  n|ifTiurM  fur  the  bbMrv(>.l  ami  obwrving  tyw,  a  nerdlf  i*  ttud 
at  a  ilKiri  iliHiuiice  in  Tront  of  lli«  fomuT,  to  Ri>rv«  h  a  acsr  ol^fct.  Tor  «liicli 
HGcoinmnHalioi)  him  to  bi>  inatl<- :  and  a  lamp  iir  cnndlc  i«  *o  dUpoaed  ■•  to  tlunw 
an  imnf^  »ii  rni-h  of  the  Ihrrc  Kurfncn  of  ti)«  utnerrej  tje.  Since  lb«  dlaUst* 
between  tau  iinHgeii  is  more  rmdily  a|ipreclat«il  tliaa  !■  a  ai(n|>t«  change  of  ru 
or  a  iinglt  lintige,  two  prisms  an  employed  m>  tut  lo  lliroir  a  double  imagv  of  iht 
lamp  on  each  ot  the  ilireo  fiitrrac«>.  Wlien  the  anterior  iiurfB«c  of  Dm  tm 
become*  more  convex  the  iir»  imagtv  rctlec.ied  from  that  surface  appnadi  twk 
oilier,  when  it  becunin  lew  efiives  they  retire  from  t»vh  other. 

Tli«te  obeervaiions  leare  do  doubt  tlml  llt«  etaential  clmnee  by  wliici 
ncc<Jium(j<)ftiiou  is  eHi>cled,  U  lui  alteration  of  the  convesiiy  of  the  ititervir 
iturrB(<e  of  the  lena.  And  that  llie  lens  id  the  ageDt  of  ac^iminodatioii  b 
Turtber  sliuwu  br  (he  fact  that  aAer  removal  of  the  lens,  as  iii  the  o[)eniiic 
for  (fitiirurt,  the  power  of  accouiiundalioii  h  lo4t.  lu  the  ca^ee  which  faan 
lieeti  recorded,  where  ey(4  from  wliii-h  the  lenH  lind  b«fii  removed  eecnttil 
>lill  to  puniteM  vome  iii'i-(>iim)o<lBtioii,  ««  niuni  tupixii^  that  titj  reul  iccutBii» 
dalioii  tuok  placo,  Init  that  the  jiupll  crmiruciea  when  u  neur  object  km 
liiokeil  at,  mill  xo  arwiptcii  in  ninkiiif;  viiiiiin  more  diatinci. 

Thi»  incrraw;  of  the  convexity  ot  the  li-ioi  \ih»  b«oii  »upp<jsed  la  be  doele 
n  coniprtsvioii  of  the  circuniferc'ncyr  of  the  Iciu  by  a  conlntctiuti  uf  ikv  farii; 
but  this  is  disproved  by  thp  fact  tbnt  accoiniiKulation  may  tukc  place  in  IJV 
from  wliich  the  iris  u  miigeiulallv  abwiit  It  ha«  aim  bwii  attribulei)  U 
VRRumotor  eJianges,  lo  incrcjiM'tl  liiloen  of  Lh<-  vimvU  of  (he  irii  or  ciliar; 
procMMs,  niRoundine  ihc  Icno :  but  th>«  alv)  in  disproved  bjr  ihc  fuvt  llnl 
nccomtnodntion  may  Tic  effictcd.  nftcr  death  in  an  cyi>  whicli  i*  nrai-ticallj 
bloodless,  by  GiiniuIaiitiK  the  ciliary  (runglioii  or  ciliari'  nerves  with  an  inla- 
runted  currcuc  or  by  other  oiennB.  The  real  nature  of  the  mecliBtiiatu  mvim 
la  De  ae  I'uUuws. 

The  lens  when  eiamiued  afler  removal  from  the  eye  i»  found  to  be  a  hcrft 
of  con  aide  ra  hie  ehisiiciiy.  When  tlie  curvature  of  the  anterior  aurfamnt 
the  lens  ia  determined,  as  may  he  done  by  appropriate  means,  in  iia  naturtl 
pufeition  iu  the  eye  at  real,  and  then  again  detcTTUincil.  nl\er  ilie  k-iiH  bait  hcM 
removed  IVom  the  eye,  the  aiuerior  surCuce  is  found  to  tie  more  ci>nvex  in  tlv 
latter  than  in  the  furiuer  case.  There  seems  to  be.  in  the  eye  in  ii»  natvtil 
4<oiiditiun,  winie  ajtencv  ul  work,  keeiiiug  ihe  anterior  surface  of  ibe  tfM 
•omewhat  fiattened.  The  siixpeuaory  ligament,  attached  to  the  choroiil  Mi 
viliar)'  procctwe*  behind,  and  paMing  over  the  fntnt  of  the  lena,  b  jutt  «utb 
a  fttnictiire  aa  would  iiroduce  this  efltcl.  In  the  iiatitrnl  pu«it)ou  of  ibt 
choroid  thi«  ligament  u  tcnxc,  and  leml.-i  to  lliilten  the  front  nf  (he  leM 
When  iho  choroid  u  pulled  forward,  ibe  lignmeut  becomes  alack  and  lb* 
knit  bulge  out  forward.  Further  the  cilian' niuacle  nitachod  im  tb«a* 
band  to  a  fairly  fixed  region,  the  junction  ol  the  fcleroiic  anil  cornea,  aai 
on  the  other  U>  the  loiner  and  more  movable  chnroid,  would  naturnllv,  abn 
thronn  int<>  cinilniclion,  pull  foruard  the  choroid  and  «n  nlacken  the  aaann- 
wiry  liganivMi.  and  hence  i>ermit  the  elastic  lena  to  bulge  out  furwnn).  AaJ 
we  have  cxiurinH-nlii!  evidfOfc.  carried  out  on  lower  imimata,  that  nimla- 
lion  of  the  ciliary  ganglion  or  of  ilf  »o^called  radix  brevia,  tlott  lead  oB  lU 
one  hniid  lu  a  conimciioii  of  the  ciliary  nin«elc  and  pulling  forward  of  tbi 
choroid,  and  on  ihv  other  hand  to  an  iucren«ed  ewrvaturc  <>f  the  aniemr 
Burfaco  of  tbo  lens.  Hence  ire  may  conclude  that  aeooioiDodaiiiin  fur  oca) 
objects  consists  e«Kiitinlly  in  n  contr.iction  of  the  ciliary  tnutole.  which,  by 
pulling  forward  the  choroid  coat  and  the  ciliary  process,  sliK'keiia  the  nuipco- 
sorv  ligament,  and  allows  the  lens  to  bulge  forward  by  viKue  of  il^  elutidly, 
HDa  eo  to  iDcrcato  the  convexity  of  its  anterior  eurfitea 


DIOrTRIC    yECHASlSM8. 


£101 


I 


I 


AccOfumoiliiii'Hi  ia  in  moat  cnwa  a  voltininry  hcI  ;  »inc«.  homsTar,  thv 
cbuigfi  ill  thi-  kiM  is  ulirnrs  accomiHiDicd  l>y  movvtikOtite  in  tho  iris,  it  will 
Im  coovcuieBt  to  cooaitler  the  latter,  oefore  wq  disuiMs  tho  nerrous  mechaDism 
of  th«  «liol»  u-t- 

JiwaiunU  of  thf  pirpit.  Thriu;>h  by  makin);  ihe  pflbrts  required  Tor  ac- 
CDtDiDodatioo  ire  can  at  pl«D»ur«  contract  or  diiaiv  tlit-  {>iii)il,  it  is  not  in  our 
txia'pr  to  brinj;  the  will  to  act  dirwtly  on  the  iris  by  it»elf.  Thia  I'sct  alone 
udkatca  tbat  tiie  nervoue  meebaniam  of  the  pupil  14  of  a  peculiar  ubaracter, 
and  such  iodmd  we  6nd  it  to  be.  Tbe  pupil  ia  coiilnteteti  (1)  when  Ui« 
miaa  (or  optic  nerve)  h  atiinulutod,  aa  wlieo  li^ht  falls  on  tbe  retina,  the 
brighter  tbe  li^bt  tbe  greater  being  tbe  coniraotion,  (2)  when  we  Rccommo- 
dale  fur  ne«r  ubjects.  The  pupil  is  also  contracted  when  the  eyeball  is  turned 
inward,  when  the  aijueous  humor  is  defirient,  in  the  vat\y  mma  of  imianuiiifc 
hf  cblorofonn,  alcuhol,  «tc. :  in  nearly  all  stufcea  of  poisuning  hj  morphine. 
pnTaoMiginiue,  and  aume  otli«r  <lrugii,  and  iu  deep  slumber.  The  pupil  ia 
diatUd  (1)  when  Hliniulntiiiu  of  the  retina  (or  uplEc  nerve)  ia  diniinulwd  or 
atmied  ai  in  piiaaiuf;  frum  a  bright  into  a  dim  light  or  intn  dnrkueai,  (2) 
when  the  eve  u  adjusted  f»r  far  r>l)jvi'tA.  Dilation  alan  (Hvum  wht-n  tht-re  i* 
an  exccMofaqtieoua  humur,  duriiif;dy!>pnwa,  during  vinluiil  mti^cular  tflurta. 
aa  lh<^  ruiult  of  a  Htiinulaiiun  of  Miiisurv  nrrv<«,  ua  an  cffcci  of  emutiona,  in 
tlir  liUi-r  vtiigcs  (if  jiniaiittini;  by  clilurutiiriii,  etc.,  and  in  all  stages  of  ptiiaun- 
iiig  by  atrnpini!  nnd  aiimc  other  clnt|ni. 

(.'ufi  tract  ion  of  iho  pupil  ia  cnuain]  by  <vintraclioii  of  the  circular  fi\>x*t  or 
sphincter  of  the  iria.  Dilatiun  is  caused  by  cuntnirli'>n  of  the  radial  fibrot 
of  the  iris;  for  though  the  cxialence  of  radial  librcs  boa  been  denieil  by 
many  ohsarrcn,  the  preponderance  of  ovidoncc  i*  clearly  in  bvor  of  their 
bdog  really  preacnt. 

Coinidt-ring  liow  vascular  the  iris  is,  it  does  not  seem  unreasonnbU!  v*  in- 
terpret some  of  the  varialious  in  the  cuditioD  of  tlie  pupil  as  the  results  of 
aimple  vascular  lur^feoceace  or  of  depleiion  brou^bt  about  by  vasomotor 
action  or  olherwiac,  the  small  or  coiitracled  pupil  corresponding  to  the  ili- 
)atcd  and  filled,  and  tbe  liirge  or  dilated  pupil  to  the  constricted  and  emptied 
condition  of  the  bloodvosela.  Tliua  slight  iiscillationaof  the  pupil  may  l>e 
observed  syuchmnous  with  the  heurt-lieut  and  others  eynchrououf  with  the 
rapiratory  movements,  llut  the  variatioUB  in  the  pupil  seem  too  marked  to 
be  merely  tliv  rlfi-cta  of  vaacular  chnngi^,  and  indeed  that  consttctiun  nt  tlw 
pupil  <«iiBot  be  wholly  (he  nwult  of  lurgescenctf.  nor  dilation  wholly  the 
rvault  of  depletion  uf  ilie  vca*«l«  uf  tbe  irii,  ia  shown  by  the  fncU  thai  both 
ibeae  event*  tour  be  wilm-Mwd  in  a  pvrfvi-tiv  blnodleaa  eye,  and  tliat  the 
movement*  of  tli«  pupil  ulxen  brought  about  by  agents  whidi  aliu  nlTtvt  the 
liloodvcawlt,  begin  a»ni«  time  bvl<)re  the  chaiig<ai  in  the  cidibre  nf  the  hloud- 
v«taeU,sDd  ind««il  may  1w  over  brtorcllicac  have  arrived  iit  tlietr  maximum. 
Moreover  the  fibr«  of  the  aymimlhciic,  which. aa  we  shall  ace, arc  ooniwnKtl 
in  cauiing  dilation  of  tho  pupil,  run  a  (otncwhat  diflcrent  murac  from  those 
which  govern  the  bloodvcaacla  of  the  eye.  We  may,  ibcrtfirrc,  adhere  to  tlie 
view  that  the  main  cliangea  of  tho  pupil  in  the  dirt«ti»n  of  nnrrowing  and 
widening  tirv  brought  about  by  contmctJona  of  the  plain  inuecular  fibres  in 
the  iris. 

.Muscninr  contractions  lending  to  changn  of  the  niipil  may  be  obferved  in 
the  eye  fvmovcd  from  the  body,  and  indeed  in  Inc  extirpated  iris.  The 
plain  mUKuIar  tibreeof  the  iris  like  other  plain  muscular  fibres  are  remark- 
ably sensitive  to  variations  in  leni|>erHlur?.  Betides  this  there  seems  to  be, 
in  ccrtaio  anioiaU  nt  leant,  a  connection  within  the  eye  between  the  iris  and 
retina  of  such  a  kiuil,  that  1i;;lil  falling  into  an  extirpated  eye  will  lead  to 

uarrowiug  of  tbe  [lupil.     Putting  aside,  however,  sucb  exceptional  events 


aiOHT, 


ri<i.9sa. 


wc  mar  lar  down  tli<!  bnmd  priDciple  iliat  coulraction  of  ibe  pupil,  Itrmiilit 
•boiit  hy  Ufcht  ralliiii:  i>d  tbe  I'etiua,  U  a  reflex  aei,  of  nliich  tbe  'ipiic  b ibe 
•flb'eiii  n«rve,  tlw  lliinl  or  Dculii-mctor  the  eRl-reiit  atrve,  and  ihe  owtn 
•otnc  jiiirtiiiii  ■>!'  ilw  liriiiu  lyiiix  beluw  ibe  i-orpont  riuudrigcniina  in  the  frtni 
pHit  or  ihe  ficicir  of  ihe  aciucduct  of  Brlriun.  Tbi*  iit  pnived  by  the  follow- 
tug  fnvi»:  When  the  optic  tierve  is  dividt-il.  iliv  fulling  of  ligbl  un  th»  rettna 
iH)  li'Dgcr  vutiri-H  n  vuutructiuii  of  (lie  pupil.     When  the  third  at-rte  it 

'livideil,  xlimulntiiin  uf  the  reiUia  of  of 
ihv  (ipiic  nerw  iio  lnDjcer  cuiuc*  nift- 
Irni-tiou  ;  but  direct  uliniuliitioi)  uf  tb» 
[loripbc-ml  iHirtimi  nf  tbi- ilividMi  ibifd 
iKTVt  CHUMS'  fxtrvRW  coatrudi'io  tf 
the  pupil.  If  tbc  region  of  tbe  brwa 
ofHikcn  uf  iilxtvr  a«  a  centre  be  «■!«■ 
fully  itiinulmi-d  contimctigii  at  tb 
pupil  will  tnkr  pIiKi>:  vwu  in  tbe  ab- 
wnnr  of  light  iiiid  n)U-r  divi^iim  of  tb 
optic  norvc.  A(1>t  rcinoral  uf  tk 
Mine  oenlrc  slimulniinn  of  tlM  rdiaa 
is  inctft-ctunl  in  Rnrnning  th«  pupil 
Bill  if  tbe  centre  aixl  iu  cnnoetiiw 
with  ihe  optic  nerve  and  ihiid  Mm 
be  left  iDtad  and  in  tburougbly  kmbJ 
condition,  contraction  of  the  pupil  viO 


-7c. 


U 


'-f—s-c. 


occur  aa  a  reeult  of  liifht  falling  on  ^mJ 


r~— -w 


^wT" 


PinnnuiHinc  BirnDiENTiTrrrN  or  mx 

XUVM  (ImiKNUIU  THE   PCIir., 


reiina,  tbou);b  all  other  nenous 
be  removed. 

The  Dervoti*  centre  ia  n<it  n  dnuhls 
centre  with  tim>  completely  indepcndeal 
htilve«.  one  for  each  eVK ;  thcro  ■>  a  n^ 
tiiiii  amount  of  funcliimiil  c<nniiuDaiM 
l)etM'cvn  |h«<  two  xidcs,  »•>  ihut  aLtn 
one  rctinii  in  Hlimolaled  iKiib  pniii^ 
contrucl.  It  might  be  imagined  ihst 
ihif  cerebral  oenire  acted  to-  a  laaie 
ccnlre,  wbofe  actitMi  wM  dimply  !>■ 
crcaMd  not  orijjiiiated  bv  the  •Itniula- 
lion  of  the  retina ;  but  this  is  disprivn) 
hjr  the  fiict  ihiil,  if  the  optic  nerve  l» 
divi()cil.subc«i(uent  rection  of  the  thin) 
Dcr\-e  produces  no  further  dilation- 

In  omiMdcring  tbe  tnovenieuta  nf  tbc 
pupil,  however,  we  bavo  to  deal  Ml 
only  with  a  narrowinf;  of  tbe  pupil 
thus  brou;>bt  about  in  a  rcHex  wav  \^ 
cotilrnctioD  of  tbe  circular  aphiiicttf 
fibres,  and  with  llie  abeeoce  ol'  eurbi 
uarroniuK-  but  also  with  active  diW 
linn  due  to  a  conlructinn  of  tlie  railial  dilator  fibres,  and  Ibia  tenders  the 
whole  nuittcr  niiicli  m'>rc  cuinpleK  ihan  might  be  auppuiied  to  be  ibveat 
from  the  simpb-  itiitcinciit  just  made. 

The  iris  ia  «upplicd,  iu  CDniDion  with  Uve  ciliary'  mtiacle  and  cboroiit,  bj 
Ibc  abort  ciliary  ncrvm  (Fis.  229,  «.e.)  comiu;:  fruin  tbe  o|ihihu]mic  ur 
tcnticular  (ciliarv)  enuglion  (lo.)  which  In  Bounvcled  by  iu  mou  wilb  tbt 
third  nerve  (r.fr.\  we  cervical  lympnihetio  nerve  (jiym.),  and  with  tbe 


IX,  opiic  Dorrv  :  1.9,  IcoiIcoMi  gkiigliun : 
t.h.  II*  tliun  max  ftom  til:  oc.ki,  iblH  at 
oculooiolar  nirre  :  fjnn.  \i»  >)rinp«ltiiiUr  nail : 
r.L  IB  Iddr  nwl  nnm  V.  opWAn.  Uir  twutl 
Irnnch  at  Ibv  u^hUialnlc  dlvlilun  of  ilit  DRb 
nrfTS :  t.  c,  Uiff  *hait  olllurr  nnrvn  Dotn  llis 
IcoUoabr  (uiBtlon  ;  I.e.  tbe  loot  tillirr 
n«rn  Cmm  ib*  raal  bmach  of  Uw  opbitial- 
Dilc  ittTMon  at  ibo  nftb  Mm, 


DIOPTRIC    HBCHANISUS. 


903 


inch  ftftlic  nitlithnlmic  di 


I  (r.  (.).  The  t\*an  dli«ry 


I 
I 


I 


ncrvr»  «nt,  mnrvuviT.  iicc<ini{iHnir<I  by  llir  Inti^  cilinrjr  ii«rrc«  (I.e.)  coming 
from  iIh'  Miiiui  DsmI  branch  of  iho  Diihthnlmic  iliviRion  of  (ho  fifth  n«rvo, 
Wbat  uri;  Um  asM  of  theae  Mv«ral  nvrvnt  In  rrliuion  lo  the  ixijiil  T 

If  the  ctrvical  ■yDipKth«tic  in  thv  neck  Iw  ilividrd,  nil  otner  portioDS  of 
the  nwTOUs  inocbitDtaiTi  bein^  iiiinct.  n  conirnction  of  the  pupil  (not  nlvayt 
wry  well  mnrkcil)  tiikw  place,  and  if  llip  pcriphcrnl  portion  (i.  r..  tlic  iipfwr 
portion  utill  <!<innecleil  witli  the  hend  >  be  Htimiilftted,  n  well -<lo vol o)icd  diln- 
lion  w  tki'  mull.  The  ayoip&thetic  hu,  it  will  be  oh'K'rveil.  an  rfTt'Ct  on 
ibe  iria,  tbir  oppcaite  of  that  whicli  it  eiercisea  on  the  blundvcssiiU  :  when  it 
i»  Mimiilnied  llie  pupils  are  dilated  while  the  blooilvoMcU  nrv  onelncted. 
Tbta  iJiluini;  iiilluenee  of  the  Bynipaihetic  may,  as  in  the  cue  of  the  vaao- 
motor  action  of  the  aame  oeri-e,  be  traced  back  down  the  nock  to  the 
npper  thoracic  ganglion  and  thence  aloof;  the  rami  commuoicantes  and 
raote  of  the  h>wer  cerviciil  and  lirtit  dimal  or  (wo  Hrst  dorm)  spinal  oervee, 
to  a  rej^n  in  llie  lower  cervical  and  upper  doreal  cord  (called  by  some 
ftulbors  the  eenlrum  ciUiytpini/e  inferiiu),  and  fnitn  iheuce  un  ihriiiu^h  the 
medulla  obloo);ata  to  a  centre,  wliich  ap|>eare  to  be  [ilaced  in  t(i«  floor  of  the 
front  part  of  the  B(|iiediict  of  Sylviiid  not  far  from  and  appsreatJy  on  nlber 
aide  of  the  centre  f»r  cimtmction  of  ihe  pupil. 

The  dilaiiiin  of  the  pupil  which  in  wiineMte<l  in  dyipncea.  and  that  whidi 
nsulu  from  •tiuiululinn  of  n'nitory  ncrvvit  and  from  emoliuna,  appeara  to  he 
bn>U){hl  alxiiit  by  ihr  action  of  the  aympiuhetic.  thu  venous  blood,  or  the 
aOMory  impuiiwii  or  the  ciiioiiomil  impiilws  »>>  iifll-cliui;  llie  dilating;  centre 
U  to  an^nni-iit  th<'  lUliilin^  iinpiilvN  procevirui^  from  it  hIoii]|C  the  xyni|M- 
ihetic.  The  i-xiiitcii(.i'  of  the  snbnnlimite  centro  in  the  ci-rvical  or  doml 
eoni,  *{wkpii  of  just  now,  i*  Kuppwcil  to  be  indicalrd  by  the  fiict  that  after 
divinon  of  the  niaduUn  oblonj.'ata,  and  conWi)uent  Deverancc  of  the  eHurenl 
paths  from  the  centre  in  the  aqueiliict  of  Svlvitie,  dilation  of  the  pupil  may 
still  b«  brought  about,  in  some  animals  at  feast,  by  dvBpnwa  or  by  adequate 
stimnlatioo  of  sensory  nervea.  A  question  ia  raised  herv  in  fact  somewhat 
similar  to  that  raised  in  connection  with  (he  me<lullary  respiratory  centre 
{)>.  47iJ);  and  here  as  there  we  may  pmhably  conclude  that  the  independent 
action  of  such  a  spinal  c«utre  is  of  Hubordiiiaie  im[<ortanoe. 

The  pnpil  then  «reuia  to  be  under  (he  doruiniun  of  two  antaifanlslic 
neobanuiDa :  one  n  ciJiitracling  m«chanl*ni,  rellex  in  nature,  (be  third  nerro 
•ervinft  as  the  efr<'ri-iil,  iiud  th«  optic  as  (be  afferent  tract :  the  I'tUvr  a  iltlul- 
ing  methaniim,  appun-ntly  tonic  in  naltire,  but  mbjucl  to  au;:wpntation 
ftnm  variouH  causca,  and  of  tin*  tlve  cervical  aym]iia(betic  it  the  pITcrcnt 
channel.  Hi-nci.-,  when  the  (binl  or  optic  nerve  u  divitlw),  not  only  doe* 
contraction  of  (bo  puiiil  coue  to  bo  manifest,  but  active  dilation  occurs,  on 
account  of  (be  tonic  dilniiiig  tnflurnoc  of  (bo  sympathetic  beloK  left  froo  to 
work.  When,  on  tite  other  hiuid,  the  sympathetic  is  divideil,  this  Ionic 
dilating  tnlluenrc  falls  away,  and  contraction  re»iilt«-  When  the  optic  or 
thini  nrrvt  is  'limulnleH,  ibe  dilating  dfect  of  the  symjinlbelie  is  overcame, 
and  cuDinK-tion  results:  and  when  the  syinpnthotic  is  atiwulated,  any  oon- 
traciinic  inHLieiiec  of  the  third  nerve  which  may  bo  prweat  ia  oreroomo,  and 
dilation  en  sum. 

But  (berc  are  oonsidcradons  which  show  that  the  matter  ia  Mill  DH>re 
complex  than  this.  A  small  quantity  of  ntrtipine  introduced  into  the  eve  or 
into  tlie  system  causes  a  dilation  of  the  pupil,  This  might  be  atlrihuted  to 
a  paralysin  of  the  third  neri'o,  and,  indeed,  it  is  found  that  after  alropiae  ha« 
ptijdueed  its  effects  the  fulling  of  li^ht  on  the  retina  no  loo^i.'er  cauMa  outi- 
tnetHHi  of  the  pupil.  A  ditfiouliy,  however,  is  introduced  by  the  fact  lltat 
wbto  the  third  nerve  ia  divided,  and  whea,  thorefore,  the  conlnicUug  oflkvli 


SH3BT. 


of  Ml!  mil  In  lion  of  tli«  relina  are  )j)ac«il  enliral)^  ou  one  itde,  anil  titerc 
noUiiui{  lu  prnttut  tbe  ity  in  pat  be  lie  pmOucing  its  <iii«iin^  vffccta  to  ibc 
utinoKl,  dilntion  it  mill  further  iucreawHl  liy  atruniob  When  )>bvs(»li|pDiM 
in  inlroiliiix'il  into  the  tyn  iv  ftyitcin,  ouTilniclion  of  ll>c  puful  i*  omad. 
wh«tli(T  tho  ihinl  iiorve  he  dividMl  or  nut ;  nnd  irbni  tbe  doM  h  nSkJCiUjr 
Htrong  t)i<;  <'<>n  tract  ion  in  so  urmt  tbat  it  <ntiiiul  \}c  urercomc  by  stimulalita 
of  tli€  M-nipnthriie.  The  dilHlion  which  la  cKUM-d  by  a  »ufli(-i«ii  <lcwo( 
fitrupiiip  nmy  he  grciitiT  than  ihnt  which  am  onlinarily  1>K  priducvil  by 
Kimiiliilinn  uf  the  sympniholic.  nud  the  ('<inlmetion  cnuoed  l>r  ■  *ullid«M 
dose  of  }ilmi»tigni)ii<- miiv  )w  grvitlrr  thnn  ihnt  vibioh  is  orilinaril;  nnr 
ilticed  in  n  rrtlfx  iimimtT  i>^  j^iRiulatinn  of  tW  optic  ntrve,  or  C%'«D  tun 
that  produced  bv  dirrcl  eliniulniion  of  tliv  third  nerve.  Ei-idt^ntly  llio* 
druee  net  either  directly  on  the  pinin  niUK-iilnr  tibrts  of  tbo  irin  or  on  ««■« 
looal  mechanism,  the  one  in  Mich  n  wiiv  tin  to  cause  diimtiun,  tli«  olber  in 
■udl  ■  wsy  as  to  canse  contmclinn.  8i)cn  ■  local  niechanisiD  cnnnot,  how- 
ever, tie  in  the  ophlhalroic  ;^nglion,  for  both  dru(^  continue  to  prndoof 
tha<e  tllecls  in  a  most  marked  de;;rcv  aller  ihe  gBD>;lion  has  been  I'XerciMd. 
We  mutt  suppose,  ihercfort',  that  the  niechantsm  if  it  exists  is  sitiiatnl  a 
the  iris  itself  or  in  the  choroid,  where,  indeed,  jtaDKltonic  uer\'e  cells  an 
abuiidaiil.  Tlie  niovemenU  of  the  iria  in  the  extirpaletl  eye.  afwlieu  of  jmI 
tiow,  may  perhaiw  be  altribuled  lo  the  same  local  mechanism.  Further  il 
Ih  siati-il  that  with  i!timuUtion  of  the  ermpaihetic,  the  latent  |>eriod,  ■'.<-.,  Ue 
)>vriiHl  iuierveninK  between  dte  betfinninj;  of  aiimulatiuit  and  the  liegiDiiia| 
of  the  movement  of  the  iris,  is  much  k'V'>I^  tl"i"  **'<'h  Hiintulaliou  of  ibt 
thirtl  ucrve,  iiidicattiij;  that  tbe  former  acta  tlirouiih  a  local  iue4,<lmuiain  b« 
tbe  tmicr  more  directly  tin  the  muscular  llbrea.  Tbe  nbole  rpieatioii,  hint- 
•wr.  of  thi*  local  mcchaniam,  and  of  the  exact  nmleoractioa  nf  tbe  varinui 
drup  and  of  lh«  cbangei  in  ihi^  body  which  luad  lo  (wntrac-tion  or  'lilntM 
respectively  of  the  pupil,  netnli'  fuller  di«cuHiuu  than  we  cui  affofl  to  gin 
to  It  here.  Wc  may  ad<l  thiil  the  local  ncliou  of  nUopinv  in  oonlm^i  muj 
action  on  the  rcnbrnl  centro  is  well  illiiKlrnleil  by  applying  atn-  ^ 

eye  locally-     Tbe  pupil  of  that  eye  dilnti-a  widt'lr:  i<>  ci>ni>i.->(i< ;« 

light  linlls  un  tbe  retina,  nnd  this  ro  uflecis  the  cerebral  centre,  ivbich  aa  mt 
have  M-en  is  not  slrietly  unilalemi  hut  in  communion  with  its  iVIlufr,  UiU 
increaitud  constricting  impnises  pan  from  both  centres,  and  tbwc.  iho«igh  in- 
ellectiial  in  the  airvpinitcd  eye,  lead  in  the  untouched  eye  to  an  iacreaued 
narrowing  of  ihe  pupil. 

Th(!  share  of  the  Mh  nerve  in  the  work  of  the  iris  aeeme  to  be  in  parta 
•entory  one;  the  iris  is  sensitive,  and  the  sensory  impuUce  which  are  fta- 
eratcd  in  it  pass  from  it  along  tbe  fibres  of  the  tilth  nerve-  Moreover  On 
lidb  in  peculiarly  rvluled  lo  the  dilating  eflecis  of  tbe  syinpathetir.  Far 
though  t^e  opbtbulmic  ganglion  does  receive  libres  directly  frooi  Ihe  carerti- 
ouf  pilous  <if  tbe  dympaiheiic.  the  dilating  aOion  of  tbe  aympatbctic 
woulil  m.'cm  to  lie  carried  out  oat  by  thate  UhivA  but  by  Bbrea  jiiiriiaii;  the 
GIt.h  nvrve.  and  {)na»ing  to  the  iris  not  by  the  ganjjlioa  but  by  ibti  ophihil- 
mic  hritiich  nnd  the  lung  ciliary  nerves  Tbe  vil-mi motor  fibres  of  ihv  ■>*»' 
pathetic,  and  tbngw  which  dilate  the  iris,  al^vr  riiiining  together  in  the  ribib 
Oorvioal  vyoipatlietic  chain,  purt  compiiny  higher  up,  the  latter  piuuuox  I* 
UiaOflMerian  j^nglioo.  and  thus  nuicliing  the  niiMil  braudi  of  |]ia  nphtSll- 
mic  division  nf  thi-  fiAh  nvrvc.  Sumir  ntti^TveRi  maintain  that  in  addition 
to  tiKVo  dilating  Hbrc^  of  [hi;  nv  in  pathetic  joined  to  it,  tbe  fifih  coiitun* 
fibre  iif  iis  own  which  bIho  am  able  to  dilate  tb*;  pupil. 

We  ninv  mm  up  the  ncrvims  nievbanivm  of  llw  pupil  then  Miaowbal  •* 
f<jIlow«.  The  «alivnt  and  miHt  frcigiiently  rviiDalcil  event,  tl>c  oontrvctioo  nf 
Ihe  pupil,  upon  cxpa«urc  to  liglit.  is  a  t«fl«x  act.  (be  centre  of  which  i* 
placed  10  the  brain ;  and  the  correlative  widening  of  the  pupil  upon  dinii- 


DIOPTRIC    XECUA.NISMS. 


906 


I 

I 
I 


nnttnn  of  liglit  in  iliie  to  ili«  innicHciion  of  th»ityin|MUbelic  mnkiiiii  iiwlf 
Mt  upnu  the  nmiiiiii  of  \u  nuinpiuiiil.  Tho  «;iiiilrftctwn  of  Uio  piipii  in  the 
nrliiT  utatrra  of  lUc  Hctiiiii  uf  bIooIioI  ■m)  chlorofonn  kik)  in  Hiunilwr  U 
ptulxililv  <lit<)  to  Ml  iiicnWwNl  acliiiii  of  llu-  cootmcling  t.-mm.  ImiI  lh« 
uBrniK  ]>ii|iil  cnu»oil  by  viicli  ilrugx  M  morphiiK*  unit  phvuneli^iiiio  i»  iluo. 
chivAj'  III  l*-n»t.  to  K  Idcnl  nclion.  The  (jilaliiig  i>trvrt)>  of  fueli  dniev  ne 
Urouine  nn-  ■!»»  luri^cly  due  to  a  locnl  nctinii,  but  in  t)i«  «'i4leiK'<l  pupil  of 
iba  lutvr  ttiu^  of  kloohol  puisoniag  anil  of  dyspnoMi  we  c&ii  prubnbly  trace 
cIm  dTccta  of  au  exhiiuslion  of  ibo  cpivbral  coiilrading  cei>ir«,  MHsted  poe- 
liblv  by  sn  tncraiecd  actiritv  of  lh«  ililatiBs  centre. 

Tlwn*  iviuniit^  h  notd  to  be  said  conceruiiiK  the  conlraclion  cf  the  pupil 
which  takes  place  when  [he  eye  is  acci>iniii(Hlat«(J  f<)r  near  obj^cta,  aiid  when 
the  |Mipil  it  lurneil  inward  (the  two  beiii);  clusely  allied,  »ince  ihe  eyes  {am- 
verite  li>  aee  uear  uhjeclH).  and  ihe  return  to  the  more  itilaled  condition 
nhtn  tlio  eye  returns  to  rwi  uud  re^tii"*  'he  accommodation  fitr  far  ohjecta. 
Tkcae  are  instances  of  what  are  called  "asaociated  muvemi.'nt«."  Two 
motenieuts  are  Ibua  apoken  of  aa  "Mandated"  wheii  the  a]>«cial  central 
MTTOoa  nieclianbni  empluyctj  in  carrying  out  the  one  act  ia  to  connected  bf 
nerruui  tiw  of  some  kind  or  othvr  with  that  eiiifil»yed  in  carrying  out  tlw 
oiber,  that  nben  we  «et  the  one  inei^hani«iii  in  aetiou  «re  unintentionally  act 
the  olhiT  in  ai'lion  ulwi.  Tlie  ciliary  niiiT«-leii  wliieh  brlus  abimC  acoiniDO- 
dali'in  arc  governed  in  ihii  action  by  fibres  which  may  lie  traoed.  through 
the  luliniy  Dervir:<  and  Iriitieular  Ka»u:li<>ii.  alonj;  the  t1iir>)  or  <h~i]1>i- motor 
Dvrvv,  to  a  ci-iilrv  which  Iic9  (in  ihigii)  in  the  hinit  part  of  ihe  door  of  the 
thir<l  ventricle,  and  which  in  enpei'ially  oonni^clcd  with  the  mo»t  anl<-rii>r 
btiadle*  iif  the  r«iiit:<  of  the  third  nerve.  Thin  centre  i«  nnder  the  command 
of  our  will;  witeii  wc  wish  tn  nccnmmodntti  for  near  objecia  wo  throw  it 
into  action,  aud  it,  when  in  action,  chHd  also  into  action  by  "  aMocintion  " 
the  Nnire  fur  the  ooutraction  of  tlie  puf^l ;  wlien  the  action  of  the  accom- 
modation centre  OMM*  and  the  eye  falls  back  to  the  condition  of  rest,  in 
which  it  is  accoinmodated  for  far  objects,  the  action  of  the  piipil-contnictio([ 
cetitre  ccasM  also,  and  the  pupil  therefore  widens. 

The  iiieclianisni  of  accommndAlion  may  al«o  l>e  effected  in  a  local  manner. 
And  tite  ilruKS  which  have  a  sjiecial  action  on  the  piifHl.  fiuch  us  atropine 
aiid  Calabar  lieau,  also  alfect  Ihe  mechaniani  of  acconiraudalion.  Atropine 
liatwlyxca  it,  to  that  the  eye  remains  adjusted  for  far  objetis;  uml  phyio- 
•tlKnunc  tbnm'a  the  eye  int<i  a  <-ondition  of  furceil  accommodation  for  near 
objeeU.  Tliia  double  acl»<in  luia  been  explained  by  the  HUppovitiou  that  ubilo 
■Iropine  paralyti^n.  pliyanalig;n)ine  tlirows  into  tonic  or  tetjtnic  oontrtietiim.nn 
the  one  hand  the  circular  mnacla  of  th«  iris  and  on  tlie  otltcr  the  cili-try 
louK-h*;  bttt  the  pheiiomeDH,  on  inquiry,  appear  loo  complicated  to  ba 
expUiaed  in  aoaimplv  a  manner. 

We  can  BceommiMlatc  at  will ;  hut  few  peraoDS  can  eflect  the  ni.-cr«i«ar]r 
cbangeio  the  eye  unlr»  they  direct  their  attention  loaome  neJtr  or  far  oliject, 
aa  ibe  case  may  be,  and  thus  avisl  their  will  by  visual  M-JiMtionK.  Ry  jinM> 
lice,  however,  the  aid  of  external  object*  may  tie  diipcnaed  with :  aix)  it  i<t 
wlieo  this  is  achieved  that  the  pupil  may  »ccm  to  bo  nuuk  to  dilate  or  con- 
tract at  pleaaure,  accommodation  being  cSoclod  without  the  eye  being  turnod 
to  any  pantcuLar  object. 

Imperfeetioiu  I'n  Ihe  Diaplrie  App(tfiilH$, 

The  emnwtrojHC  eye  may  l>e  taken  as  the  normal  eye,     The  myopic  and 
hjrpermelnjpii-  c\e*  mav  be  cunaidered  as  imperfect  eyes,  lhoui;h  the  former 
oerliuu  ail  van  itt^  over  the  n'>rmal  eye.    An  eye  mighl  be  inyupic 


810  DT. 


fw>m  too  i^TeMt  a  conrexiiy  of  tlie  cornea,  or  of  the  anterior  iurfiiw  iif  ' 
lens.  OT  fnun  permnn^nt  »r>ni)ni  of  tUe  accomiMnd«ii"ii-mech«nwni,  or  fn 
ton  Kreut  a  len|[lh  "f  f  hi-  ]<mic  axl*  of  the  eyeball,  TUe  last  ajipear*  to  b» 
the  UBital  (-iiuw.  Siiniiurly,  mo»t  hy|K'rmi'trrt|>ic  eyea  powctb  loo  cliort  a  hiilh. 
Moreover  in  Ihetttronglymarkwl  inyopi*- pve  there  w  fWquentlv  hypertnifihT 
of  t]>e  lonKitiidinnl  (meridiniial)  lihrts  nf  ihi-  ctltiiry  mu»cle,  often  upokwi  (/ 
«xeluure]y  lu  the  cilinry  rawwle,  nod  atrophv  or  alm-iice  of  ihf  rimiUr 
fibrai;  ill  the  hri>Tr(H'trcipii"  pvc,  on  the  othi-r  Ituiii).  tho  rirrtilar  flhr«  art 
well  devdopct!  luid  the  mrriilionrtl  Rhm  si^nty.  Tlii'  |tml>y<i|)ie  eye  ia.  h 
we  havp  it-en.  iin  cvd  normnllv  conallliitivl  in  mhit-h  th«  inwer  of  m-wwniwi- 
dntion  hiiN  iMt'n  lo«t,  nr  is  fiiilini;  thmnch  increioing  wenknen  nf  the  inliary 
mi>«dc  or  a  loM  of  elaalicity  in  the  lens,  or  through  tbe  pArta  beconinf 
ripiH. 

Sphtrwal  abemfiott.  In  a  Fpherical  l«i»  the  rayn  which  iinplnice  on  th# 
rircumrerence  are  brong^ht  to  n  fociia  soonirr  tlian  thoM  which  p«M  nnutr 
tlie  wntre,  nti<l  the  rsys  praceedin^  from  n  himiDoii«  pntnl  nrr-  no  Inasfr 
brmigbt  to  a  mnt^le  focus  at  one  point  hut  form  a  number  of  fiict  ml  fUffinMil 
distanflos.  Hence  when  rays  nre  allowed  to  fall  on  the  vhole  of  ihi-  k-iin.  thi 
imaiie  formed  on  n  ecreeti  plat.'ed  in  the  focus  of  the  mora  c<-niml  ranfi 
blurred  by  the  diil\tB  ion -circles  cait«ed  by  the  circumferentiiit  raw  whiA 
have  been  br»u(rht  to  a  premature  f»cii!i.  In  an  ordinary  nr>t>i.-(il  in'tninMet 
Bph«ricsl  aberration  is  obviuled  bv  a  diai>hragni  which  ■hTiiii  nfT  the  iwn 
circiiniferential  ra«.  In  the  eye  llw  iri*  ia  an  adiiirtabtc  diaphmi^a ;  laJ 
when  llie  pupil  contracts  in  near  vision  tlie  more  diversent  ravs  priM-efdinc 
from  a  near  ohj eel,  which  ten<i  to  fall  on  the  circumferential  parts  of  tHa  lot 
are  cut  off.  As.  however,  the  rvfriiclive  jwiwer  of  the  lens  doee  not  IncrctM 
renularly  and  progrewircly  fn>m  the  wnire  to  the  circumfertnee.  bul  rari* 
mo«t  irrec'ilarlr,  the  purpooe  of  the  nnrmvioi;  nf  the  pupil  cannot  be  timplt 
to  obviate  Fplierical  aberration  :  and  iniWd  ilic  other  <)[ttieal  imperfectKM 
of  the  cvo  nre  so  srrtt.  that  wich  spherics)  alHrralioia  na  are  caused  by  lh( 
lens  produce  no  obvious  effeol  on  vision. 

Antiirmnliun.  We  have  hithenu  treated  Ih*  ere  as  if  its  dioptric  mtAm 
were  all  pnnsof  iwrfeot  spherical  auriiicen.  In  reality  thi*  i<  rarely  the  cmm, 
either  with  the  lens  or  wiib  the  cornea.  Slight  doviatioii!'  do  not  prndun 
anv  marked  effect,  but  there  is  one  deviation,  knowD  aa  regular  a*ti|croaii>"<< 
wbieti,  preeenl  to  a  certain  extent  in  most  cv«»,  very  lar^ty  developed  fat 
Bome.  fre(|uenlly  leads  to  very  imperfect  vision.  Thia  delect  la  d>ie  to  the 
dioptric  surface  beinj;  not  spherical  but  mora  convex  alont:  one  meridiaa 
than  another,  more  convex,  for  instance,  along  the  Tcrlicnl  than  alone  th* 
horizontal  meridian.  When  this  v  the  case  the  rays  pmceuding  from  ■ 
luminous  |MHnt  nro  not  brounht  to  a  ein);le  focus  at  a  point,  but  puawwi  t*« 
linear  foci,  otie  nearer  than  the  uormal  and  correspond injr  to  ihi-  laurr  iiinvat 
surface,  the  other  further  than  the  uormal  tociis  and  cornvponttiii),'  In  thn  ha 
convex  Burface.  If  the  vertical  meridians  of  the  mrfaca  be  n>on>  oonva 
than  (he  lioriruntal,  then  the  nearer  Huear  focus  will  be  horiconlnl  and  tla 
farther  linear  focua  will  lie  vertical,  and  ptcr  verfn.  <This  can  tw  shorn 
mud)  more  effectually  on  a  modet  than  in  a  diagram  in  which  we  are  limiltJ 
(A  IwodimeusionH.)  Now,  iu  order  to  see  a  vertical  line  distinctly,  it  ia  muoh 
more  iiuportanl  that  the  rays  which  diver^^elrom  the  line  in  a  acrica  nf  har>- 
innlal  planes  tihould  be  brought  to  a  focus  properly  than  thow  which  divet^ 
in  the  vertical  plane  of  the  line  itaelf ;  and  nmilarly,  in  order  to  see  a  hcn- 
lontal  line  diMinctly,  it  is  much  more  im^iortani  thai  the  rays  which  (liret)^ 
from  the  line  in  a  seriea  of  vertical  planee  should  be  brought  to  a  fociu 
properly,  tlian  those  which  ilivertie  in  the  borixontal  plane  of  the  Hue  tiAtf 
Hcuoe  a  hoiitonial  line  held  before  an  aitigniatio  dioptric  aurface,  idmC 


DIOrtRIC    XBCBAinSUS. 


807 


i 


ronvox  in  rlir  vcrfical  rnpHdiniif,  uil)  ^ve  riiw  to  ihp  iniocv  of  a  h'lrin'iital 
line  nt  iW  iioin-r  t'uciie,  ihe  veMical  rny*  iliverKinj,'  ftoni  Inc  liur  being  lirrw 
btDOgbl  to  a  liiwar  hi.iri«iiilal  I'ocitB.  Hiiuilarly,  a  verlicnl  line  h«li)  bofurt; 
the  aBni«  enrface  will  give  rise  lo  an  intake  of  a  vertical  line  at  the  furihcr 
fucuf,  llie  borizAiitnl  mrn  iJi\er),'ii](;  t'toiu  llie  vertical  line  bein^  bete  bntiight 
to  B  linear  verlieal  fueua.  In  other  words,  with  a  dioptric  surlnce  nmet 
convex  in  the  renicAl  meridtuDa,  horizonlal  liuee  are  broughi  to  a  focua 
aoooer  than  are  vertical  Viote. 

Slnst  eye»  are  thus  nior«  or  lew  aflticroaltc.  and  (tenerall}'  with  a  frrealor 
cnnvexity  aUng  the  vertical  lueriOians.  If  a  ua  of  horito^iial  or  vertical 
lines  b«  IooIcmI  bC  or  if  the  nt^ar  piiiai  of  Hrc'iuiuioilatiiiD  be  deierDiiDed  by 
Scbeiuer's  experimeul  (p.  8U0K  for  the  iietslle  plactd  firac  horiiuin tally  and 
then  vertically,  the  hnriziontal  li»«  or  nM'dle  will  be  duttoctly  visible  at  a 
tliorter  distance  frum  the  eye  tlinn  the  vertical  tinea  or  needle.  Hiniilartr, 
the  vertical  line  niunt  be  furihcr  from  the  eye  thun  a  horiituDtal  one,  if  both 
tit  to  be  seen  dtMinelly  at  the  wine  time.  Tin-  oaiiite  of  asiiK>nati»ui  is,  in 
tbflgmit  niuj'irity  of  ciiseii,  the  uni'i)iiMl  curvature  iif  the  mniea ;  but  some- 
timea  the  fault  lit*  in  the  lens,  its  was  the  caM  with  Yoiin){. 

WbeD  the  curvature  of  the  c-nira  or  lens  dilfcn  not  in  two  meridiana 
uiily  but  in  wveral,  irregular  B.-<tik!mBti.ini  in  th«  result.  A  oertain  amount 
of  irrefcular  asti|[matisin  cxisU  in  tii'Hit  leniv^  thus  causing  the  image  of  a 
bright  (U'iut,  such  as  n  star,  t»  be  nut  a  circle  hut  ii  radinic  figure. 

Chrrtmnlie  ahrrrnUon.  The  diflercnt  my»  of  tho  «|ieclriim  nri-  of  dilfemil 
rrfningihiliiy,  tlitsM:  townril  the  violet  end  of  (hv  sDectrum  Ix-ing  hroiigbl  to 
n  f(K-tU  wHiocr  thun  those  near  the  red  end,  This  in  optical  instruiueiil*  it 
oltviateil  hy  using  conit>ou»d  lenses  made  up  of  various  kinds  of  gliiM.  In 
iIm  oyc  wo  have  no  evirlenoe  that  the  lens  is  so  conslitutcd  as  to  correct  tbb 
faolt ;  Mill  the  total  dispetvivc  power  of  the  instruinctit  i?  so  smnll,  that  such 
itSOUBt  of  chmmalic  aberration  as  does  exist  attracts  litlle  notic*.  Never- 
tiMtcHsoRiaslijihl  aberration  may  be  ilelec'ied  by  c«rel\)l  observation.  Wlion 
the  sfm'triiiii  is  observed  at  some  disliitice  the  violet  end  will  not  be  ecwd  In 
focuB  at  the  Mime  time  as  the  re<l.  If  a  liiniinuua  |)oint  Iw  hioked  ai  through 
a  narrow  orifice  coveie^l  hy  a  piece  of  violet  glnsa,  which  while  shutting  out 
the  yellow  and  green  allows  the  rei]  and  blue  rays  to  nuw  thd'ugh.  there  will 
be  seen  allernnlcly  an  image  hiiviiig  n  blue  centre  with  a  re<l  fringe,  or  a  r»l 
centre  with  a  blue  fringe,  ac(^or(ling  us  the  iuuige  of  the  point  Itmked  at  is 
iJirOfra  on  iin«aide  orotber  of  the  true  focus.  Thus  suppoting /l  Fig.  %\fi.) 
to  be  ihe  plane  of  tlm  mean  focu*  of  A,  the  violet  rays  will  be  brought  lo  a 


Via.  ro. 


DiioaAM  lU.ivnuTDKi  CiiRminr  AsissinMi, 
(t  i>  il>i  itlapifl«  (Diftcs :  trnt*wsta  ibc  blun.  >nit  Srihe  r<1  ajn:  flstbglbesl  |dinaar  tlia 

blur.  Jt  uf  Ills  red  nn , 

toKW  in  llie  plane  V.  and  the  nA  rays  in  the  plane  ft.  If  the  nija  be  aujp- 
pus(^l  to  fall  >ti\  the  retina  between  I'Bnd/,  the  diverpng  or  blue  ray*  will 
form  A  crntre  xurroundeil  by  ilie  still  converging  rrd  rays;  whereas  if  the 
ray*  fall  •■u  the  reitnu  bi-ixeeu/and  H,  the  (Mtnverging  red  raya  will  form  n 
ccDtfv  with  (lie  still  divcrginif  blue  rajra  furmiug  a  fringe  around  tiMBk 


SieHT. 


tbe  mrs  Tnll  an  lh«  reiinn  ni/.tbo  two  kiniU  ufmn  will  he  misM  togtlbir: 
U  will  be  Mt«  fniii)  th«  ttgun,  ihc  circiimlvmilmr  Mill  ooavttrging  nd  n; 
A  r  M  it  outc  ilic  plniiu  of  th«  rvtina  ii,  in  ordinary  vistua,  ■coumpnniiic)  tif 
the  divrrfpng  vidIh  rny  A  (i.  Mud  thus  by  n  sort  of  compmniion,  mt  m 
logctlirr  even  (lit-  myit  which  <liffbr  moet  in  rvfniction. 

Eiilojidr  phi"iom«nii.  Tli«  various  inmliu  of  the  eye  are  not  itnifotmlT 
IniiiitfiHmit;  thi?  rays  of  light  in  pRuing  thnm^h  thein  iiiidrrgo  local 
iihKi>r|>li<>n  und  rtfrnclioD,  imd  ihus  various  (hndows  nre  ihniwn  on  lh« 
n.-linii,  of  nbtcb  we  bocoine  cioitci'ius  lu  iiiiporfection?  in  ihc  ft«ld  of  vinoa. 
Mpecially  wbcn  the  ey«  is  dir(!<.-te<(l  to  a  iinifonnly  illuiniunlcd  aurbce 
Tbew  tin  spoken  of  as  eotoplic  pheoonieua,  aoil  are  very  varied,  iniuiy  forw 
having  been  deecribed. 

Tlifl  ruoBl  cominon  are  tbcee  caused  by  th«  pf«sence  of  fiualiog  bodis  in 
tlte  vitreous  humor,  the  so'called  tini»tat  I'oiilanla.  Tbeao  are  reatlily  wn 
when  the  eye  ia  lunied  toward  a  uiiifurni  atirfuce,  and  nre  freiiuently  vttf 
troubleeonie  iu  Wkinji  through  a  niiL'ro«c(i|>e.  Tbey  are  opectnllr  obvioui 
when  diverKCDi  rays  full  ui>oa  the  eye.    They  aaiume  the  firm  of  ru«i  aad 

S [roups  of  l>eadit,  of  single  ttesda,  of  sireakit,  {mtchts,  and  )(nuiule»,  and  aaj 
le  reco^'nixHl  by  their  alnioal  conliuunl  tnoveiDuiL,  ca|>ei-tally  when  the  htat 
nr  eye  ia  moved  up  and  duwu.  When  nti  atti^inpt  \t  made  ui  fis  tbe  vwica 
upon  thi-m.  tbey  immeiliately  float  awar.  Tearw  on  tbe  conit-n.  t»iu|¥mry 
uueveiiiiciw  na  the  aiilcrior  surface  of  the  eonie*  al\or  tbe  eyelid  tuu  btas 
pnneil  on  il,  and  iiujwrfci-tinii*  in  the  ten*  i>r  its  capsule,  kIimi  give  rise  tn 
visual  tinngiii.  Not  uul'rei|iicntlv  a  rndiitt«  liKure  corr<-fl{K>nding  f>  Uw 
■rrangciDunt  of  the  fihns  nf  llie  Icnii  makcgi  t|.-<  appi-nnincv. 

Iin|ierfoctioii.'>  in  the  luarj^in  of  the  pupil  a|ipi'fir  in  the  rhadour  of  the  irit 
which  bound'  the  field  nf  vinun ;  and  the  mdvonieiilji  >>r  the  irii'  in  nne  «y4 
may  b«  reiidereil  visible  by  looking  at  n  bright  point  or  luminous  surfact 
through  a  pin-bole  iu  a  cnrd  pluml  close  in  the  front  of  the  eye,  in  the 
anterior  foous  in  fact,  and  then  alternat«ly  elosinj;  and  o[)ening  ibe  other 
eye ;  the  tiehl  of  the  Hrtt  may  be  ohserved  to  contract  when  li^ht  enler^  ami 
to  eipnnd  when  the  light  is  shut  otf  from  tbe  seoond.  The  iiie<lia  of  iheeVD 
are  fluoreseent :  a  condition  which  favura  the  pereeplioii  of  the  ullra-TiuW 
rajs.  If  a  white  sheet  or  white  cloud  be  looked  at  in  dAyligbt  tbruuifb  a 
Nieol's  prUm,  a  somewhat  bright  double  cone  or  double  tuft,  with  the  apion 
loucliiog,  of  a  faint  blue  color,  is  seen  in  ihe  centre  of  the  field  uf  vitian, 
crosaed  oy  a  Mmilar  double  cone  of  a  somewhat  yellow  darker  color.  Tb<M 
are  spoken  of  as  Haidinger's  brushes ;  they  rotate  as  tiie  prism  ia  rotated, 
and  are  nuTiifised  to  he  due  to  tht?  nne<|uul  absorption  nf  the  iNilarJuHl  li^hl 
in  the  ycthin  ^[lot.  The  primti  tuu»<t  l>e  freijuently  rotaicil.  n»  wlten  tW 
prism  reiuniuft  at  rest  t)ie  |ilien»ineiiu  fade.  LuXly,  the  otxioil  nrnDge- 
nietils  have  a  further  imperfecliou  in  that  the  dioptric  turfnctt  nre  nut  Ire)* 
ceutjed  uu  the  uptic  axin. 

Visual  SESSATioxii 

Light  falling  on  the  retina  excitca  seiuory  itnpuUet,  and  the«e  paaung  op 
the  optic  niTve  to  certain  parts  of  the  hmin.  produce  ohaonB  in  ccnail 
cerehrul  i>(riir;tur«'«,  and  thuH  tpve  riwe  to  wbtit  we  call  a  teiuttluut.  In  a  sta- 
aatiou  we  ought  to  be  ahlu  to  diHtinguiiih  brlwvca  the  events  ihrougb  whid 
tbe  impact  of  the  ray*  of  light  <yn  the  retina  is  enable<l  to  geiicnite  etOMfy 
impulser,  and  the  evenU,  nr  rather  Mries  of  events,  through  which  ibat 
■cnwfy  impulsra  ifor.  jud^'ing  hy  tbe  analogy  of  motor  nerves,  wc  have  on 
rauDtl  to  think  that  they  undergo  any  fiindanieulal  changes  id  psetiing  nhiaj 
tbe  optic  nerve),  by  the  ageney  of  the  cerebral  arrungemeoia,  (Hvelu|i  iuix  > 


TTSCAf.  SENSATION'S. 


909 


rinuntioii.  Huch  an  nniilrtiii*,  however,  h,  at  present  nt  lea>t.  in  mort  pnrtlcii- 
Un,  iiuili-  l>evi>niJ  oiir  )iawer ;  iind  ne  muiil  therefore  treat  ut'  the  seDBaiioils 
tia  n  wliolr.  (Ii*lin);iii>hiiif;  iK'tucr-ii  ih«  fverijibenil  ami  ceiitrul  pheuootena,  on 
th<;  mn-  octuai'im  when  nv  arc  iible  to  dg  m. 


The  OrijfiH  of  Vutml  ImpuUet, 

Of  primnr;-  importfluni  to  lh«  uiKientamling  nf  Ihf  wnj  in  vhich  lumin- 
am  andiilationa  giro  riM  to  tboec  ncrv»ii»  change*  which  pa»  alon^  the  opiic 
nerve  ua  vignnl  itnpulwfl,  n  the  fnct  thai  tho  rays  of  light  pmdiicv  iWir  em<ct 
by  acting  tiot  on  (lie  optic  nerve  iiielf  hut  on  ir»  terminiil  organs.  Thrj  pnu 
ihrotigh  tbc  anterior  lareiv  of  the  retina  iippdrently  without  inducing  any 
edcct:  it  is  not  till  they  hQve  reached  the  region  of  the  n)d»  and  cones  that 
they  set  up  the  cbangrs  ciincemed  in  the  gfneration  of  visual  impnlpcs;  and 
Ibe  inpnUM  here  geiiemtr<l  tmvel  hack  to  the  layer  >if  fibres  in  the  anterior 
■iTftoe  of  tbe  rellDft  and  ibonce  pass  along  the  optic  ner\-e.  Thitl  the  optic 
fibres  are  themselves  tnscnuble  to  light  and  that  vixoal  impulses  begin  in 
the  region  of  rods  and  cones  is  shown  by  the  phenomena  of  the  blind  ep>it 
and  of  I'urkJDJ^'s  figures  respectively. 

Jilinii  »pol.  There  is  one  pan  of  the  retina  on  which  rays  of  light  fall- 
ing give  rise  to  uo  sensations ;  this  is  the  entrance  of  the  optio  nerve,  and 
Ibe  cnrrespniiding  area  in  the  field  of  visioD  is  called  the  Mind  spot.  If  the 
vinal  axis  of  one  eye,  tbe  right  for  instance,  the  other  being  chised,  be  fixed 
on  ft  black  s|>oi  in  a  white  slbeet  of  paper,  and  a  small  black  object,  such  as 
tbe  point  of  m  (|uill  jwu  dinped  in  ink,  be  moved  fEmdually  sideways  over 
the  paper  away  to  tbe  iniiaide  of  the  liehl  of  vitiou,  at  a  certain  distunee  tbe 
black  point  nf  the  <]iiill  irill  tiimppear  from  view.  On  ci>nliDuing  the  move- 
nH'nt  (till  further  outward  tbc  point  will  agaiu  cnme  into  view  and  cnntinnv 
in  sight  until  it  is  Inst  in  the  |H'riphery  of  the  field  of  vision.  If  the  pen  be 
used  In  make  it  mark  on  th<>  paper  at  the  moment  when  it  is  lost  to  view, 
and  lU  the  moment  when  it  comes  into  sight  again ;  and  if  simitar  marks  bt 
niKiia  along  the  other  meridians  as  well  as  the  horizontal,  an  irrcgiitar  out- 
line  will  be  drawn  circnmscribing  an  arm  of  tlic  field  of  vision  within  which 
nya  of  light  produce  no  visual  sensation.  This  is  tbc  blind  spot.  The 
dimeDsions  of  the  figure  drawn  vary,  of  courw,  with  the  distance  of  the  paper 
fironi  the  eye.  If  this  distance  be  known,  (he  sire  as  well  w  the  position  of 
ibearea  of  tlie  retina  corresponding  to  the  blind  xpot  maybe  calculated 
from  the  dingrammatic  eye  (p.  Mt4v.  The  prisiiion  exactly  coincides  with 
tbe  entrance  of  the  optic  nerve,  and  the  dimensions  {shout  l.>^  mm.  diameter) 
•Im  correspond.  While  drawing  the  outline  as  above  directed  tbe  indiea- 
tioM  of  the  large  branches  of  the  retinal  vessels  as  thev  diverge  Iram  the 
cntnuce  of  the  nerve  can  frequently  be  recogniied.  Tne  existence  of  the 
blind  sjwl  is  also  shown  by  llie  fad  that  an  image  of  light,  sufficiently  small, 
thrown  upon  the  optic  nerve  by  means  of  the  ophthalmoKope,  gives  rise  to 
no  sensattuns. 

Tbe  existence  of  the  blind  a{)ot  proves  that  the  optfc  fibres  themselves  are 
InseMible  to  light:  it  is  unlv  through  the  agency  of  the  retinal  ex|>ausiuit 
that  these  can  be  atimuhited  (>y  luminous  vihrations. 

Pitrtitijf'4  fipin*.  If  one  eutcn  a  dark  room  with  a  candle,  and  while 
looking  at  a  plaiu  (not  iiarti- colored)  wall,  muvea  the  candle  up  and  down, 
holding  it  on  a  level  witn  tbe  eyt-s  by  the  aide  of  the  head,  there  will  appear 
in  the  Arid  nf  vision  of  the  eye  of  ihv  same  iide,  [ifojecie>d  on  the  wall,  an 
image  of  tlw  n<linal  vmmIs,  Qtlilc  similar  t»  that  seen  im  luokini;  into  an  vye 
with  the  ojditludiBOMOfie.    Tli«  field  of  vidian  is  illuuiinutvtl  with  u  glare. 


dio 


SIOUT. 


and  on  tliia  th«  branched  retinnl  reMela  apiwnr  lu  KbiuUou,-!.  In  tlii*  mocU 
of  eipcrimeiitiiif;  the  light  eot«n  lh«  eve  ilimiigh  the  (^inii>n.  nixl  nn  traue 
of  thi!  nuulle  ia  furinei)  on  the  duhI  mle  of  (he  retina ;  guid  it  i*  thn  ligSl 
eniniintinfi  from  this  image  which  throwt  ihadoirA  of  the  rttiomi  vmhIi  on  lo 
ibo  read  of  the  reiitia.  A  fur  better  mttluxl  b  for  «  Moood  penon  to  omicm- 
tratc  the  rays  of  light,  with  n  lent  of  hiw  |iowcr,  on  to  the  uutatdo  of  tb« 
sckrotio  juHt  behind  the  cornMi;  tlic  tight  in  this  cb»o  rtDBiiiitw  frooa  tk 
illiiniii)ated  S[Hit  on  tbc  Hdi^ntic  nml  [loiHing  Mritiebt  thmiigh  the  rilpeow 
humor  throWH  a  direct  vhiubiw  of  the  vtmel*  on  to  the  retina.  Thus  the  nji 
ptw<ing  tbrtiugh  the  tclerotic  at  A,  Fig.  231,  in  thediredion  br,  will  throw  i 
ebsilow  i>f  the  Te««et  '  on  to  the  rctinnat .';  thi#  will  np))«ar  iwadark  lincu 
11  in  the  gluri'  nf  On:  li<,-]d  ijf  vi;<irti).  Thin  provv  tbal  the  Elmcture*  a 
which  vL'<ua]  impulMw  iirigiiinle  mtiiil  tin  behind  th«  retinal  vewcts,  otfaemin 
the  »lindi>WN  of  tbc^c  could  not  be  porceivod. 

If  the  light  he  mciveil  from  A  to  a,  the  «hndow  on  the  retina  will  mon 
fhtm  a  to  ",  and  the  dark  Iin«  in  the  field  of  viiion  will  more  from  B  to  X. 
If  the  distance  B  A  be  nMiosured  when  the  whole  image  is  projected  at  a 
known  distance,  t  B  from  the  eye;  k  being  the  o]>tical  centre,'  then,  knowing 

rm.  III.  FiQ.  at! 


JfeoRBllI  nXnTRATDN  Tlti  FOUATIOH  At 

^gaai)i»>  nDiiRMwan  rut  lLi,niis(Tio:< 


nuoaut  iLuenuTDM  m  Tnnuneal 
i-i  iiKisuf  •  navnta  wimi  nta  lummm 
Ik  IiiBscrxD  nnociMi  not  COwtB*. 


the  distance  it  i$  in  the  dingrammutJc  ere.  the  distance  ,'  «  can  be  calcabUel 
But  if  the  distance  ,^«  be  thuv  estimated,  and  the  dbtanoo  &a  be  directlf 
mnuurtd,  the  distances  ^I'.nv.i-i.  <iv  can  be  calculated,  and  if  the  appearaoo* 
in  the  field  of  vision  is  rmllv  caused  by  the  shadow  of  ''  falling  on  ,i,  thew 
diiitanccs  ought  to  correepoiid  to  the  diHtancesoflhe  retinal  veeeeUi  fronlh* 
sclerotic  b  on  the  one  band,  aii<l  from  that  |>»rt  of  the  retina  ,i  where  Ttwid 
impr.-mons  begin,  on  the  other.  H.  Miiller  found  thai  the  dialanix-  ,)  i-  thai 
calciiliilcd  corresponded  to  the  distance  of  the  retinal  reanU  fr<>iu  the  lam 
of  rods  and  cones.  Thus  PurktnJ^-'H  figures  prove  in  the  first  plui.-«  that  tbt 
•ensory  impulees  which  form  the  commencement  of  visual  lensatinus  oHgi- 


Im»  ncBf  tu  iicHuiloc  (nri^eo.  at  about  It  mm.  4Uuac<  iniai  (bi  rcdaa. 


-I 


TIBVAL  BBXSATtOKS. 


911 


naie 


pttK  of  tlie  rc4inn  Itdiiod  tlic  rrliiiiil  vcmels. 


tome  pttK  ot  tlie  rc4inn  tiohiDij  the  rrUiiiil  vcmels,  i.  p..  loniewhora 
lielweeo  (Ih>iu  aad  the  c-Iiorui*!  coal :  and  11.  Mullt^r'it  cak'uUliunf  go  Ikr  to 
^ow  liiat  tliey  originate  hi  ibe  niuitt  pusl«rior  or  exirtnal  pun  uf  tliu  Trlina, 
vie,  itie  layer  of  rods  and  cones.  It  muel  be  lultniiml,  tiowcvvr.  thttl  11. 
Muller  B  TMuliB  were  Dot  sutBcitrDtly  exact  to  allow  any  great  ecnws  to  be 
plac-etl  on  tbis  arKumcni. 

Id  tlie  secuod  inctiiod  of  exftcrimentiD);  tlie  imoKe  always  inovea  in  the 
OBine  direclioo  bs  tbe  livht,  aa  it  obviuutily  uiuat  do.  Id  llie  flrai  nivlbod, 
«b«re  the  lifilit  eoiera  tlin>Uftb  tbe  cornea,  the  iioafice  luovee  iji  the  unie 
direction  u  tbe  lijjlit  wIivd  tbe  li|{bt  in  moved  froni  tifi,bi  to  lell,  pruvideil 
tbe  moveiDeiit  does  not  exiotid  l>ey<tud  tbe  middle  of  tbe  vorDea,  but  iii  ibe 
(ippowte  direclion  lo  the  light  when  ib«  latter  it  aioved  up  aud  dowo.  In 
I-ig.  232,  whieh  rei>r<*ciitii  u  liurix»utnl  aeetiun  of  no  eye,  il  a  be  tuoved  tu  ii, 
b  Dill  utDVe  to  ,i,  tbe  dlinduw  on  tbe  rvliiiii  c  to  r,  otxl  tbe  iniuge  d  tu  i.  If. 
un  ibo  other  hand,  k  be  Hiijipiwol  tu  iiiuve  ubove  the  plane  u I  tbe  jiajwr,  fr 
will  move  below,  lu  funi>et(uttii'c  c  will  tuove  above.  Mid  </ will  a{ii)iear  U> 
niovc  Ix-'low,  t.  «.,  d  will  aitik  nn  a  ri.'>cii. 

It  it  dtairwblc  in  thii»:  cii--<u>  to  move  tbe  lt){bt  to  and  fro,  i-M[>erially  in  tho 
fitat  tDCthwt.  all  the  relitiH  nnun  In'i-omi-n  lircd,  ami  the  inrnj^u  liidiv  awiijr. 
Sonic  ubKrverv  can  rvcognirj-  in  ihc  axiit  of  virion  a  tnitit  hImiIow  corrv- 
•pODdiug  tu  iht  ed^  of  ibe  ile|iri«iiun  of  Lin-  fovm  cmiliulis. 

Tb«  retinal  vewcU  niny  iilao  lie  remlervd  Tisiblo  b;  looking  through  a 
■mull  ontiov.  nieh  a*  n  |>iii-bole  in  a  i-nrd  plaeed  vluM  to  tbe  «ye,  at  a  bngbl 
Ituld  uncb  a*  tlie  Ay,  ami  moving  the  uritiw  very  nipi<illy  from  ^e  to  Mdo 
or  up  oud  down.  If  the  Riovcnicnt  be  from  nitlc  to  «ide,  the  v«mgI«  which 
run  vsnical  will  be  iK-en  ;  if  up  and  down,  tbe  horizontal  vcmcU.  The  liDft 
capillary  vtvmI*  are  seen  mom  niHly  in  tbis  way  than  by  Piirkinji-'»  method. 
'Vliu  same  uppcnraocee  may  also  bo  produced  by  luoktog  through  a  micro- 
Kope  from  which  the  objective  has  bL>en  removed  and  the  eyepiece  only  left 
lor  in  irbtch  at  least  tber^  is  no  object  dialiDOtly  in  focus  lo  the  field;,  aud 
moving  the  bead  rapidly  from  side  to  aide  or  backwanl  and  forward.  Or 
the  inii-rosco|ke  ii«ell  uiny  be  iiivvv<l ;  a  circular  movement  of  tbe  Held  will 
iben  brinj;  both  tbe  vertically  aud  hurit<uulaUy  directed  ^'eoMU  into  view  at 
tbe  Mme  time. 

TiK  pkolt-riiemiAtiy  nf  llie  rdhia.  In  AeekiDK  to  understand  how  it  ia  thai 
ra)a  ul  liuht  lalliUK  upm  tbe  ru^iou  of  the  hkU  aud  ivimw  can  ^nve  ri»e  to 
wniurjr,  viiuial  inpuUM  Id  tbe  optic  ncrvo,  we  may  adopt  one  or  other  <if 
two  viewa.  Od  tlie  one  hand,  we  may  »uppiw«  that  the  vibratioiiH  of  the 
Ctber  arv  able,  tlirough  the  uiimna  of  tbe  rctmal  ap|iaratutt  of  the  rod*  and 
ounea  fur  exiiiuple,  lo  give  rum  in  mme  way  or  »thcr  to  molecular  vibration* 
whieh  are  the  Oegiaiiiiig  of  the  nervuua  impulwMt  in  tbe  optic  nerve.  Ho 
Mtuifactary  explauuiioti  of  how  such  a  cluinge  can  be  hnrnghl  about  faai 
been  oHufvd,  and  indeed  tbe  dilficullitv  of  such  a  cuuceptioD  are  very  great. 
On  the  other  haml,  we  may  more  naturally  luni  to  a  dicmical  explaiuUion. 
We  are  familiur  with  tbe  lact  that  rays  of  light  are  nbic  to  bring  about  tbo 
doouniptMUou  <il'  very  many  clwmiical  Bubflttnoc*,  and  »'e  aocoruingly  sprak 
ot'  llune  mbslancei  as  bciog  sctwitive  to  light.  All  Iho  bcU  dwolt  on  in  this 
book  illu«trale  the  groat  complexity  and  cormtponding  ioRtabiliiy  of  the 
coni}io»ilioa  of  protoplasm.  And  we  might  rca>^'<iiiibly  »iip|H««  that  proto- 
plwm  itnelf  woubl  bo  e«nsiiive  to  light:  that  is  lo  say,  mat  rays  of  light 
Miling  ou  cTcii  uudiffvrcnlinted  protoplasm  might  set  up  a  d(>compueiliou  of 
thai  protoplasm,  and  so  inaugurate  a  molecular  diaiurbancc;  iu  other  words, 
that  light  nii^bl  act  as  a  direct  stimulus  to  proloplBem.  As  a  matter  of  lact, 
however,  such  evidence  as  we  at  present  poaPCua  goes  to  show  that  native 
uuditfereutiated  pruiuplaem  id  u»  a  rule  not  teoMtive  to  li|{bt  (iliat_ 


913 


SIOHT. 


tbon  particular  waves  which  whuti  ibcy  full  oa  our  reliui  giro  ri«c  in  u»  Ui 
tb«  Mneation  ut'  liiflii),  tliuiigh  in  tbe  cnw  of  some  lowly  or^imtDS,  »Iiqi« 
I(r«to[>tuni  Bjchibits  very  liltip  (liH'enmtiaiion  mh]  in  narlimlar  cnotailu  nv 
pigment,  a  jvnsilivoiieai  to  light  hits  been  obef>rved.  >or  caa  we  be  mrprind 
St  this  i n (I i (Terence  of  prut"|il»sni  when  we  rcDect  tlisl  wliat  we  may  call 
pure  prutuplasm  is  remarkable  liir  its  traii»]>arenoy,  ifaat  is  to  say.  the  raji 
of  light  paM  tbratigb  it  with  the  Blijfliieei  passible  alnorptioa.  But  in  order  ^ 
thai  liKhl  may  pruduoe  obemtoal  eDei-u,  ic  iuii»t  be  amorbed  ;  it  mun  Jj^H 
apetit  in  i}oii>j{  the  obemioal  work.  Acorilincly,  the  first  aitrp  tow-ard  ll^H 
liitmaii'in  uI'  an  Dr^an  of  Tteiun  is  the  diirereoiiaitou  of  a  |>oniuu  of  fiiotir 

iilaam  into  a  ptgiiitiii  at  once  capable  iif  ahsi>rbing  littht  aiid  eeaiiure  la 
ii;ht.  r.  e,,  undt^rguinj;  deoouipositiuii  upoii  ex|Wflur«  to  light.  An  arj^anina, 
a  iwrtinu  of  whinte  pruioplasoi  bml  thus  beoxne  diflVrvutiatcl  intotucfas 
pigment,  would  be  able  to  reaut  toward  tight.  Tbe  light  fiillinj;  im  tU 
ui^Dism  wuuld  be  to  part  absorbed  by  tbe  {Mgrnenl,  and  th*^  nya  thai 
aW)rl>tHl  would  produce  a  chemical  acIJuu  anil  iM  frw  chutnicul  aiibaUUitn 
whirh  lii^foiv  wt^re  iiol  pnnciil.  Wv  have  only  to  suppoiM  tliat  the  cbiMnial 
siihiiliinciit  are  ul'  siicli  a  naiure  aa  to  act  lu  a  *timiilu9  to  the  prtiioplnaio  «l 
ullicr  jiurti<  ot'lbi^  orf^ni»m  (and  we  have  manilulii  evidvnoc  of  th<'  ex<|iiiHla 
»en»iiivi-ii(vi»  of  prtilnplnaiii  in  general  to  cbeniical  slimMli),  in  ontrrtiifo 
how  my."  or  li^ht  falling  on  the  organiani  might  excite  movouirnta  in  il,iir 
modify  moveiuenin  which  were  being  enrricil  on,  or  might  othorwiao  alftrt 
the  organism  in  whuli-orin  part. 

iSuch  c>ii»idcralii>n»  a«  thi;  t'uregoing  may  be  applied  to  even  the  cumpJei 
organ  of  virion  of  tbe  higher  nnimnln.  If  we  suppose  that  the  actual  ler- 
niinaiiiinB  of  tlic  optic  uervt^  arv  onrnxindod  by  siibatances  sensitive  to  li^i, 
thto  it  becomes  my  to  imagine  how  light  falling  on  iheae  seii^itire  Mb- 
BlMicee  should  set  free  chemical  bodies  pueMased  of  tbe  pru|>erty  of  aciiiif 
aa  stimuli  to  the  actual  nerve eadinga,  and  thus  give  rise  to  vbunl  ln)(mlfn 
111  the  optic  llbrea.  ^V^e  say  "  easy  lu  ima^ii'^,"  hut  we  are  at  prtnt  &r 
From  being  al>le  In  give  definite  proofs  that  such  an  explanation  of  the 
orij^n  of  visuul  impukes  is  the  true  one,  prolwble  and  eniiciu|i  M  it  may 
apiwnr. 

One  iif  the  mi»t  striking  features  in  the  stnictute  of  the  ratios  I*  tl^J 
abuniiancv  of  black  pigment  iu  th«  retinal,  or  aa  it  la  aometinMt  C^^^H 
choroidal,  epithelium.  It  in  liilboult  In  suppose  that  tho  sole  tuneiloB  fl^^ 
this  pigment  i*  to  absorb  iJii?  auportliioiiH  raya  of  light,  and  thai  the  layi 
tbiisahvorbcd  are  put  to  no  mw  but  oimnly  wantcil.  Aim!  indeed  it  baabwn 
ihown  ibiit  the  pigmroit  is  acnsiltve  to  light ;  but  the  ohangca  in  it  iadtiaid 
by  light  an-  excenirely  alow.  Mort'ovcr,  ita  pnwncc  cannot  be  of  funita- 
tnciitiil  impDrtanee,  since  virion  is  not  only  pomihle  but  lairly  distinct  witk 
nibinof.  in  which  this  pigment  is  aliscnl. 

Then  agflin.  in  the  viwl  majority  of  vcrtehrato  animals,  tbe  outer  limbs  if 
the  rxids  are  sutfuoed  with  a  pnrplish-n'd  pigment,  the  co-called  visual  purpk, 
whidi  is  so  eminently  sensitive  »>  light  that  ininges  of  external  objects  Day 
by  appropriate  means  be  pholographcti  iti  it  on  the  retina.  When  ibe  «j* 
of  a  frog  or  of  a  rabbit  is  examined  in  an  ordinary  way,  with  full  ex|>0Mn 
to  tight,  the  retina  appetirs  colorlem.  lluc  if  the  eye  be  kept  in  the  dork 
for  some  lime  before  it  is  examined,  the  retinii,  if  removed  rapidly,  will  W 
fuutid  to  be  of  a  beauiit'ul  purplish-red  color.  Upon  ex|vjsurc  to  light  tW 
color  changes  lo  yellow  and  then  fades  away,  leaving,  however,  the  rtfioa 
Dot  only  while,  hut  mure  opaque  than  it  was  before.  ITjion  cxaininadoa 
with  the  micriwcojie  it  is  louud  that  the  purple  oolor  is  oonlined  exdoainlf 
to  the  ntds  and  to  the  outer  limb*  of  the  rotU,  the  inner  limbs  beiog  whoUj 
deroi<l  of  it. 


he  color  of  the  rndx  u  <lu<-  tn  thi-  presoDc*  of  a  (lisliitct   tiigmciit.  lh« 

'  tmub)  purpk,"  (liSiiai'd  ihnxigli  llir  «ih«Unc«  of  the  uuirr  limhf ;  siimI  this 

may  be  rxiniclcti  rmm  (Ih;  rud»  by  dinolvitig  thcM  in  Bii  ti')Uoius  wkitiun  of 

bil«  hIib.     a  dnr  nurpUt  soliition  u  thus  obUiinexl,  which  m  cu|wb!«  of 

beitiK  blenched   by  ttis  nctiuti  of  light,  iin<l  tn  ils  genernl   features  aixl  l>e- 

■  liaviur  is  ttimilnr  lo  the  pigmiitl  ae  it  iintuniily  exiele  id  th«  retina. 

I      Visual  purple  is  fountl,  ai  wo  have  eai<l.  eseluNvely  in  the  nuier  limbs  of 

Hlie   ni(U:  it  Imih  never  yet  been  fouiKl  in   the  eniies,  and  it  is  acconliD]{ly 

^WMCDt  from  the  retinaa  (such  aa  thott  of  anakce},  which  are  comjiooed  of 

4ooea  only,  and  from  the  macula  lutea  and  fovea  centralis  of  the  retinas  of 

nan  and  iIm  ape.    The  intensity  of  the  coloration  variee  in  ititferent  animals, 

and  iW  retinaa  even  of  »t>me  animaU  pooeeasing  rocla  (bal,  dore,  hen  j  aeom 

ta  be  whollv  devoid  of  the  visual  purple;  it  is  i^nerally  well  nmrketl  in 

Rtioaa  in  wiiiuh  the  ouler  limbs  of  the  rods  are  viell  developed,     (la  abaeaoe 

or  pmeiice  is  not  demndetii  im  uuclurnal  habits,  since  Ihe  iutense  oulor  of 

the  retina  cif  the  owl  is  id  atrung  contmst  lo  the  abaenoe  of  cqIut  id  the  bat. 

It  has  lii'i-ii  found  tn  lli«  reiJoa  of  the  embryo. 

The  vioiial  purple  b  bleaclied  unl  ooly  by  wliite.  but  alaci  by  luonocbr't- 
mntic.  light.  Of  ibe  various  prismaUo  ran  Ine  moat  iieiive  are  ihe  jfreeniili- 
vvllow  m)'v,  thuae  to  the  blue  side  t>{  tlitat'  onming  next,  the  leuot  active 
bring  thi-  red.  Now  it  is  preci;elr  the  green isti-ycllow  rays  which  arc  mo«t 
readily  alwurhed  by  ibo  eol'ir  ilaoff.  A  naiurul  colored  retina  or  n  nolulion 
of  TwiiRl  iiuqilc  eivta  n  diffune  tpeelruiu  nilhuui  any  defined  alsorptioii 
bandi,  aiui  acvorUinx  tn  the  amount  of  culunug  inalerial  through  which  the 
light  pBWM,  ahwrpttoo  i*  aeen  either  to  bo  limited  to  Ihe  grveoiah  ycllotr 
part  of  the  cpectrum  or  to  iprcad  thenco  toward  the  blue,  and,  to  a  mueh 
Ira  fitenl,  toward   the  retl.     Thtm  the  variouji  priomalic  riiy*  produce  n 

ttWo-chemical  eDiL'el  oo  the  viaual  purjilv  ia  pro[>orlii)ii  as  they  nre  uhajrbed 
ly  iL  L'lider  the  action  of  light  tbc  vihuhI  purple,  whether  in  solution  or 
in  iia  ualural  coiiditinn  in  the  ruds,  pH«s»  tnrixigh  a  purplinborauge  to  a 
yellow,  and  tiiially  becomes  coloricaa;  and  we  appear  to  be  JiiMilicd  in  speak- 
ing of  a  "visual  yellow"  and  "visual  white"  ae  products  of  the  plwlo* 
ehemit-al  chatl(^  UoderBOne  by  the  visual  purple. 

Fur  (be  nUutmtion  ef  the  visual  purple,  atler  it  haa  been  destroyed  by 
light,  llie  maintensDce  of  ttie  nrculation  of  the  blood  through  the  tueuea  ^ 
tbe  eye  is  not  eaieiilial.  The  choroidal  epithelium  has  by  itiielf,  provided 
that  it  atill  retains  its  tiaeue  life,  the  power  of  regenerating  the  purple.  If 
a  |mrlioii  of  ihe  retina  of  an  excised  eye  be  raised  from  its  epithelial  bc«l, 
bleached,  and  then  carefully  reatored  to  its  natural  poeititui,  the  purple  will 

.return  if  tbu  eye  be  kept  in  the  dark.     The  churuidal  epithelium  way,  iji 

Ukii,  be  Kpoken  of  aa  a  "  pnrpurogenoua"  membrane. 

W    If  the  image  of  iorae  bright  object,  such  aaa  lamp  or  a  window,  be  thrown 

[mi  to  the  retina,  eith«r  of  an  eye  lu  its  natural  piMitioa  or  of  one  recently 
•xcNcd.  care  having  been  takeii  to  keep  the  retina  for  some  time  proviouM 
■way  i'roiu  any  raya  of  light,  tbe  portion  of  the  retina  od  which  the  raya 
have  (alien  will  lie  found  to  be  bleaohe<l,  the  reat  of  tbe  retina  ttnaiuing 
purple.  In  fiK-t,  an  "  opuigrum  "  uf  external  ohjecta  may  thus  be  obtained ; 
aixl  if  lh<t  n-tina  be  removed  and  treatc<l  wtlh  a  four  pereenL  aolutioa  of 

tintit^h  alum  lictore  ihe  choroidal  epithelium   haa  bad  time  to  obllieraU  tba 
ilcachiii^'  rH'X'iR.  ihe  retina  may  n-niain  [iern)ui>cntly  in  tltal  cotiditiuii;  Ibe 
jihiito^clieniicai  eilcrt  may,  a«  the  phiito^:rMpIivr*  aay,  be  "  fixed." 

It  aetmed  very  tcni[niug.  vapiwially  upon  the  first  diseovery  o(  it,  to  sup- 
poae  that  tbil  viaual  purple  is  directly  confirmed  in  vi»ion.  If  ne  aupptiw 
that  visual  purple  iL»clf  i»  inert  towurd  thv  ending*  of  the  ofttiv  iMrvc,  but 
,liiat  eilber  vuual  yellow  or  vintul  whik%  i.  c,  »oiiur  product  of  ibe  action  o( 

M 


'J 


914 


SIGHT. 


light  on  visual  purpItN  may  net  as  •  ■timulua  to  tboee  endingg,  tfae  wkj  Mtmi 
Of)flwd  Ift  uwleniiaiidin};  liou-  rays  of  li(>lit  can  i;ire  riae  lo  eeoaorr  ini|Mt« 
in  Ui«  npiie  nerve.  UnJbrtunatel.v  visual  jMirii'o  is  nlioeiit  trota  tlie  <»■« 
nixl  rmm  (lie  Tuvea  ceniraliit.  whU-b,  as  we  ahall  see.  l>  the  r«Ki"i  <*f  diiUaa 
it  i#  lurilier  eutirely  wautitif;  in  aonw  aDiiuale  wliioii  umloubtedlt 


VBion : 


see  vcr)-  well ;  nod,  lufttly ,  auinmU,  well  u  frags,  iiaiurallj  poanasuig  Ik 
pigment,  coiiLiniie  to  nee  rerv  well,  and  even  ajtparenlljr  to  see  cnlors,  trb» 
tbcir  vixiiiil  purjile  liaii  htxii  ulMi)Iiitel}'  blcaehttil,  »» it  mav  be  by  prohaied 
rspiHurL-  of  tlie  vyti  to  Hlmug  liu;hl.  W«  wniiot  thereiure,  ut  preeenl  il 
kn*t,  i-xfilniii  the  origia  of  vlsiinl  Tcapulsea  bjr  the  help  uf  rkual  piur|de.  ii 
tlio  winie  time  tiH  history  BU{[f|:e«ta  that  some  sabttancea,  sensitive  like  it  to 
light,  htil  tiulikf  it,  coWlnai  utid  tltervdciTe  esea^Hiig  oWrvalion,  may  nil, 
and  liy  phultt-chomical  chatij^  be  ibc  mean*  of  exciting  tttv  optic  ornw. 
And.  u«  we  vJinll  tee  later  on,  one  iJicory  of  color  vinkui  is  bawd  oa  lis 
nwiiniptimi  that  viiton  is  carried  on  in  aonie  way  or  otiter  by  changes  ia 
wbut  Riay  be  called  the  visual  wiibttancn  preaent  in  the  n-tiiia,  tbtae  h^ 
sUin<:t-9  bi-iiig  uM-il  lip  mill  rvguneratnl  tw  vision  ia  going  oii. 

But  even  nitmiitiiig  an  prooable  tlic  exi»lenec  of  (hew  sensitive  visual  mI»- 
stances,  the  ohnrigtv  iii  whicli  lead  tu  stimulation  of  th<'  teni  endings  of  tlM 
TCtimd  Dcrvoii*  Rieehaiiium,  ne  CAniiot  nt  pNaent  state  anytbiag  d«(iBtt«  eea- 
cerniiig  thoH-  ncrvc-rndings  or  the  maimer  of  ihoir  stimuluttuti.  It  may  U 
that  even  the  outer  limlw  of  the  rods  and  cones,  iu  spite  of  the  appaisM 
break  of  conliriuiiy  lictitecn  the  outer  ami  inner  limlw.  are  really  ntmm 
in  nnlurc.  It  mny  he,  on  the  other  band,  thai  the  outer  limbs  are  dllMT 
purely  dioplHc  in  tiinction,  or  are  associated  with  the  seusitive  Ttsual  M^ 
stances  in  such  n  vrsy  thiit  the  purely  nervous  structures  mtnl  be  cnnsidatal 
as  extending  no  further  ut  least  than  the  inner  limbs.  We  oiunutasyM 
make  any  deKuite  statement  in  the  one  direction  or  tlie  other. 

In  i»nnection  with  the  origin  of  visual  impulses,  we  may  |ierhafa  call 
attention  to  the  remarkable  changes  which  the  eella  of  the  retinal  pignmH 
cmthelium  undergo  under  the  intiuence  uf  light.  Wlien  an  eye  ha*  bsa 
siiut  (fir  from  nil  jiglit  for  tume  little  time  tlie  piginetii  is  oou'cvotnitsil  is 
the  budiei)  of  the  ceils,  and  the  remarkable  lilamcntou^  proonsm  of  tits  artk 
with  llie  pigment  granules  or  ervdtaU  which  tbey  carry,  eihaiid  a  slight  da- 
tBn<«  onfy  between  tbe  limbs  of  the  roils  and  c»nes  (about  ooe-lhird  ihni 
the  length  of  Uie  outer  limbn  of  tbe  nnla).  Under  the  influence  uf  1^ 
theae  proccMca,  loaileil  with  |)i;cmeHt,  thrust  them.ielvn  a  much  lunger  as; 
down  tiiwani  tbe  external  limiting  mvnihnine-,  in  ci>i>s«(|uenoe  n  i  iniijilitalti 
(luantity  of  pigment  is  found  niiiweil  between  the  outer  mad  even  ilie  iaMr 
limbs  of  tbe  rods  and  coiiea ;  iiul(«d,  tho  initer  limbs  of  the  ruds  fweliing  si 
the  same  lime  become  jammed,  an  it  were,  In-twocn  the  niiuiea  of  figm&i, 
cuiuing  the  epitbelial  layer  to  adhere  very  cloaely  to  tho  layer  of  rmli  sad 
cone*. 

Thi-  retina  and  optic  nerve,  like  other  iiervoits  struetunv.  develop  elccliie 
currenlH,  whieh  may  he  sjioken  of  us  currents  of  re«t  and  currents  of  acOM. 
Tlwy  may  be  shown  by  j>lneiiig  one  electrode  on  the  retina  of  a  bisecteij  syi; 
or  on  the  cornea  of  a  wholo  one,  and  the  other  on  tbe  optic  nerve,  or  b  af 
part  of  the  eyeball,  or  even  nn  some  dixtant  part  of  the  ImkIj.  Tbcrsit 
also  maiiifestnl  by  the  iM>lat«<l  retina  ilsolf.  The  pbenomena  appear  soar 
what  complicated  by  the  appenrnnce  now  of  positive,  now  ol  ncgainr, 
variations ;  but  this  fact  eomi-s  out  clearly  that  the  inrideocc  of  ligh.  m 
the  irritable  retina  develops  an  electric  change,  the  ma)^nittide  of  which  titi 
a  certain  extent  prn]iorti<>nntc  to  tho  intensity  of  the  light  acting  aa  a  4i»- 
ulus-     The  changes  acconiingly  diniint«Ji  and  cease  to  appear  as  th«  rrluu 


iufllly  loMS  Iti  irritability  after  >leiiih.     We  may  iidil  tliat  th<M  tJeoirie 
iKifDuna  apjienr  tu  Im  ijuil*:  loilopciuleni  of  the  uuitilitiuu  arihsVimal 
purpk. 

k  .SimpU  SentaUoM. 

RtlttloH*  of  thr  Mfiuation.  to  the  tiimiihu.  If  vt  put  ii»i<l*  for  ihfl  nrcmiit 
kit  <|u«Uun)>  o(  rulor,  we  may  my  that  Hght.,  vi«wi:)l  «'  a  *(iniu)u)  nltcctiiig 
Um  retina,  varin  in  iolcn^ilv,  that  if,  iti  iliu  rni-niv  vf  the  Itiniiaoiix  vibrn- 
vlinns  u  maoifmn)  by  Ihdr  ampliliiHv,  ami  in  iliiration,  that  it,  in  titi!  ivnelh 
BbT  tiiiiv  a  diirccfeion  of  wares  conliiiim  In  full  u]mhi  tlir  retina.  Tho  ofleot 
nf  ibv  light  will  also  (toneiid  oti  tho  t-xlcnt  of  retinal  mrfiicc  cxpomd  to  the 
taminmM  vibrations  lU  tne  mme  lime,  Taking  a  tiioiiiiiiiis  point,  in  order  to 
«UtBinat«  iht  buier  circiiniRl.inco.  we  mny  makr;  the  TDllowing  •tatemonls : 

The  aRMUton  has  a  duration  miicli  irrrnli^r  tlinn  that  of  ihu  stimulus,  and 
in  this  rMpwt  is  comparable  to  n  nmsciilur  contraction  c»iise<l  by  such  a 
stimulus  ns  a  sio^de  induction  slim-k.  Tlic  eontailion  iif  a  flash  of  nght.  for 
iaatanc«,  laaU  for  a  much  longer  time  Ihatt  that  during  whiL-h  luminous  vibra- 
tioits  are  &lling  on  the  retina.  Ht-'ncc.  when  Iwo  rtimiili.  such  as  two  flashes 
of  light,  f^dlitw  each  other  at  a  sufficiently  short  interval,  the  two  sensations 
are  lii«ed  into  iine :  and  a  luminous  point  moving  rapidly  round  in  a  circle 
l^ivea  rise  to  the  sensation  of  a  continuous  circle  of  light.  This  again  is 
quite  comparable  to  muscular  leuiniis.  The  interval  at  which  fusion  takes 
place,  that  is,  the  interval  l)etween  successive  stimuli  which  must  be  exceeded 
ID  order  that  succcasive  distint-l  sensations  msy  be  produced,  variee  acconlinj^ 
to  the  intensity  of  the  light,  being  shorter  with  the  stronger  light;  with  a 
faiui  light  it  ia  about  ^  second,  with  a  strong  light  ^g  or  ifg  second.  This 
nuiy  be  shown  tty  rotating  rapidly  before  the  eye  a  <li»  urruDged  villi  alter' 
nate  blatik  and  white  aector*  of  ei|inil  width.  With  a  faint  ilfu  mi  nation  the 
flickering,  indintive  of  the  succeioive  M^usatioim  frum  thi?  white  Mctors  not 
bring  eompI«t«ly  fuM.'d,  etmist  when  the  rotation  beonnw  >o  rapid  lluil  each 


pair  of  black  and  white  iieclon>  takes  only  ^  aeemid  in  pawing  before  the 

bcye      When  a  brighter  illumination  i«  useil  the  rapidity  munt  be  increiuwd 

Pbrlort  the  flickering  rlisa[i[H^m.     That  jwrt  of  the  H.-iii(utioo  which  is  rw:gg- 

niM^I  an  lasiinu:  aAer  the  ccwaticm  uf  thenlimulus  is  frei^ucntly  s[)ok«n  of  na 

llin  "  atU-r-imiigi'." 

Though  th(!  duration  of  the  afterimage  is  loiigt-r  with  the  sirongtf  light 
(that  caused  by  looking  even  niomentarily  at  the  sun  lasting  for  some  lima). 
lite  cxnimenceiDCiit  of  the  di-dine  of  ibn  s-^nsntion  hcginn  relativdy  Mrlitr, 
hence  th«  greater  dilficullr  in  the  c^Niplole  fusinn  of  siicecasive  atnaations 
with  the  strongrr  light.  The  interval  at  which  fuoiim  ink*"  plaew  ditfers 
with  dilTentit  colors,  being  shortett  with  yollow,  iulenudiate  with  red,  and 
loomt  with  bliK. 

'Die  duration  of  a  stimulus  necessary  to  call  Jortb  a  eenntlon  U  exc«od- 
ingly short:  thus  iheshortcat  ponible  flash,  such  ns  that  of  unolcelncs|»srk. 
gives  RM  to  a  sensation  of  light. 

Objacta  to  motion  when  illuminated  by  a  single  electric  spark  appear 
motionless,  the  stimulus  of  the  light  n>fl«cied  from  ihem  ceasing  before  they 
oan  make  an  appreciable  change  m  their  jHwitioo,  When  a  moving  body  is 
illtimiDaied  by  several  rapid  tfnshes  in  sucoessioD,  sercral  distinct  ituagea 
oorrespondisg  to  the  positions  of  the  body  during  the  several  flashes  are 
geocrated  :  the  images  of  the  body  correapoodiog  to  the  several  flashes  fall 
on  different  pario  ot  the  retina. 

TUe  inteiuity  of  tlie  aauation  varies  with  the  luminous  intensity  of  the 
a  nux  candle  appeara  bri]{hler  ibau  a  ruAhltgfai,    Tli«  ratio,  h»w- 


»l<t 


BIGHT. 


ov«r.  of  tlie  fTDMiion  tn  the  (limtilua  u  Dot  a  timjAt  one.  IT  tlie  luiiiiu<«itr 
of  uu  ubjrot  bo  graduHlly  increaMd  Truia  n  retf  fteble  unge  to  a  T«ry  brishl 
one.  it  will  1>c  fniiml  ihnt  thoiigti  ihecurn^ponding  Komliona  IlkeniMgrnu- 
nlly  inori'dK-,  thr  iiicn-meiits  of  Itic  Mtuation^  due  to  increnMrnU  of  lli» 
liiiiiitiiLi«.it}'  grndunllv  ilimiiiieli :  and  ut  Initl  nn  ioereiiM.-  of  the  luraiBontjr 
prndiicrs  till  npiiirniilile  incivxEc  nf  M-iwntioD ;  n  li^ht.  wbni  it  rcMlia  ■ 
ccrtiiin  lirighlnnK.  ii|i[)('Krs  m  liright  tlint  nu  mnmil  trll  vrh^-u  H  bteoaii 
■»r  l>rightri.  Hviice  it  is  niucli  c-imivr  to  iltHlingiiixh  n  xli^ht  dilfvmMlof 
brfghlnw«  bct*wn  two  feeble  lighlji  tliiui  ihu  Hinic  liitrcrmoc  tH-1«Ma  t«u 
bright  lighls;  wc  mil  ciwily  tell  tbc  diHi-wiicc  iM-twet-ii  a  mvblJghl  and  ■ 
WHXrniiilb':  l>tit  two  f^unn,  or  <-vcn  Imt  bnglit  liiiii|»,  mir  of  nbicfi  dilrml 
from  the  orhcr  nirn-lv  l>y  juKl  tbe  iiiinilirr  i>f  luniinoii*  nty*  whkb  n  nt 
(-BiidlFi-niili  in  iiditiiion  to  thorn- uriii  furib  by  a  ni*bligbt.  would  aiipMrb) 
Uf  to  luivc  oxnclly  llio  rame  brighinoK.  In  a  diirktnnl  r<H>in  nn  olijcd 
plnwd  Iwfon^  H  cHiiillu  will  throw  what  wr  considiT  a  dpv|i  slindaw  ao  ■ 
sheet  of  pnpt^r  or  any  wbilc  Miriam.  If,  bi>w«ver.  tunlight  bu  aJknnd  lii 
fall  (in  tlic  pnperat  tlic  vnnio  timo  fmm  the  oppmilv  fidv  the  nhoilnw  »  du 
longer  visible.  The  ditfercnoe  between  the  total  light  n-fU-cled  fmni  tktl 
part  of  tlie  |>ii]>er  where  the  «hndi>wwni>,  and  whieli  i»  illiinitiiAli.tl  byibrtui 
iiloiie,  nml  ibiil  rcHocleii  frnm  the  nvt  of  the  [injier  which  if  illuminntal  lit 
the  cfliidle  nt  well  ne  by  the  sun,  renitiins  tbc  aame;  yet  we  rail  Do  UiDgn 
apprecinio  (hnl  difTcrGiice. 

Un  the  other  hnnd.  if  tistd^  two  ruehliglits  we  throw  two  sbodowa  on  a 
while  surface  and  iDiive  oue  nmbligbt  nway  until  the  shadow  uitiatd  b^  k 
ceRses  to  bo  vigible,  and,  hftTinc  noteil  the  disUiuee  to  nbieh  it  bad  in  bt 
moved,  repeal  the  same  experiiiieut  with  two  wax  caudte».  we  shall  fiai 
that  the  wtix  candle  has  to  be  moved  juat  aa  far  as  the  rusbliglil.  Iti  fol 
it  id  (bund  by  careful  ubi««rvaiioii  that,  nilhin  tolerably  wtilc  limits,  lb* 
■mallcat  difl^rence  of  ltjj;lit  which  we  can  atiiirbciate  by  visual  a^UMtion*  isi 
ronstant  fraction  (about  ito'^)  of  the  total  lunuDutiiyeniplnyed.  TI>e«aM 
law  linldagoud  with  regard  to  the  other Koaca  aawcll.  Thennialli'st  diflirmo 
iu  length  w«  can  deivct  between  two  linea,  one  an  ineh  lon>;  and  the  otW  • 
little  Inw  thauan  inch,  iit  the  >ame  fi  action  of  au  Inch,  thai  thr  »lIlalIrftdiir^ 
L-nce  in  length  we  lan  dcieet  Iwtwecu  a  liui;  a  fool  long  nn<l  one  a  lUlJa  \m 
than  a  foot,  ia  of  a  fnut.  Put  in  a  more  gcn«rnl  form,  then,  i)m  law.  wbieb 
b  ofti^i  called  ^Veller'^  law,'  in  aa  follows:  When  a  aiiniulua  n  coaUauaUf 
incrcafeil,  the  increase  of  tttiiuubin  neeiioary  to  eflll  forth  the  aia>llMt  m» 
rivhic  increase  of  aeiisatiun  nlwuyH  hvan  th«  mux  proportiuu  la  tb«  aUs 
Miniulu». 

Itiffinrtion  and  Jyimtni  of  Kntaiimt*.  When  tight  falls  on  a  large  portte 
oF  (he  retina  the  total  teimtiou  prcMluced  »  grisirr  iu  iim-tuut  ihaa  wbw* 
nnnll  portion  only  of  ih«  retina  is  aflccted ;  a  large  pi«<-i-  nl  whita  |a}ai 
pnxliat-o  »  gn-aler  (ulal  etfect  on  our  conntioiisness  than  a  siimll  one,  Uwup, 
If  the  mrlaces  be  uniforndy  and  equally  illiiminaieil,  the  inUnrity  o(  the 
sensation  is  in  eneh  case  the  same;  the  small  piei-c  id  juaper  B]>i>ean  ai 
bright  or  nii  "  while  "  a«  the  laiga  ono.  If  the  images  uf  two  luminous  ub- 
jeets  Itill  on  the  rclina  at  sufficient  diuances  apart,  (bu  const<)uent  aenwlim 
are  distinct,  and  ihe  iuiiiuity  of  each  sensntion  will  dcjwnd  solely  u|iaa  tbc 
luniiniiily  of  the  conx-sjiondin);  object.  If,  however,  the  two  nbjects  an 
made  lo  approach  each  other,  a  point  will  be  reached  at  which  the  two  ica- 
sntioDB  are  fused  into  one.  When  this  occui?  ibe  iuluiiuiy  uf  the  total 
fensation  produced  will  be  greatber  tbsn  that  of  either  of'lhc  M-nMthiiu 


>  riMD  wblidi  Fcrliaa,  bjanuaummloB.  ol>l«liuaaiM'linwltHit*>i'>nwloa«(-lbtaiul>.«U(fe 
Is  MmtUnua  iHMmellr  tio^"  "'  ■*  PMhiivri  law. 


bj  the  einj^le  olijecU.  A  number  of  luminous  p  linU  seatu-rcij  ovi-r 
I  iurfiiw  irould  appear  each  to  hnve  n  oeriain  Imj^hlQcas ;  euch  would 
give  me  to  a  e^iualioo  of  a  certain  inlemilv.  IT  tbey  irere  all  gathered 
into  one  spot,  that  ijiot  would  appear  far  briifhter  than  anv  of  the  previntis 
pointa ;  the  intcnaitr  of  the  sensatiun  would  bo  Rreater.  We  may  theroforo 
wppoaa  the  retiM  to  bo  divided  into  nr^aa  cirreapoudiog  to  aensatioiiil 
unita.  If  the  iiiMj(«a  tkwn  two  luRtinnus  ohjecU  fall  on  separate  tiiuaI  areas, 
if  we  may  *»  mil  them,  two  distinct  aen-talinnA  will  be  produoed;  if.  on  the 
cmtrary.  thev  both  fall  nit  the  aarae  visual  area,  mie  aensatioa  only  will  be 
produced.  Where  the  senuttions  are  sepAtate,  the  intensity  of  the  one 
(with  est-eptions  hemtler  to  he  raentioiiei))  ia  nut  aHiK^ted  by  the  preaeoM  of 
t)>e  other ;  hut  whcr«  they  becnroe  fuied  the  ititeuitty  r>r  the  united  senaa- 
tiooa  U  KreatiT  than  either  of,  thoui;h  not  e()iial  to  the  «uin  of,  the  aJQ^Ie 
■entaiion*.  The  exiatence  of  theae  >en«aiii>aal  uiiii«  t*  the  basis  of  distinct 
Tbiuu.  When  wc  ^enk  of  the  sinallett  iiiee  visible  or  ilL>tin;.'Liidliable.  we 
are  referring  to  thi*  <linvusio[i<  of  tin-  retinal  arviu  iMrrai|>oiiiliiu[  to  theae 
aenaatiiuial  unita.  The  retinal  arva  mu«t  be  carrfiilly  dialloguiafaed  ftofa  the 
■anaatkMUil  unit,  for  the  NenxatiDu  ic.  tv  we  have  .-ven.  a  praceaa  whoM  arena 
atrMdica  fri>m  the  retina  to  ciTtain  purls  nf  the  bmin,  and  the  eireunojorip- 
tion  of  the  *eiimtiimNl  unit,  though  it  muM  b«^in  aa  a  retinal  area,  must  aUi> 
be  cntitinuei)  m  a  <vrehnil  aiva  in  the  brain,  tlic  latter  oorratiMndiux  to, 
and  U'ing  an  it  were  the  proj«i(:ti»n  of,  the  former.  With  matt  people  two 
atani  apix^r  as  a  Kingin  »tar  wbeii  tlw  distanoo  between  tbein  aubteadi  an 
auRlv  of  len  than  6i>  Kcondn ;  and  the  best  ey«a  g«n«rally  lail  to  diaiinguish 
iwo  (tarallel  white  sUeakc  whttn  the  distance  mjtwoen  tbe  two,  measured 
from  the  middle  of  each,  8uhicn<li>  an  angle  of  less  than  7S  aeoonds.  Some, 
howeveT,  i-nn  >li#tinffuish  obioits  •'iO  sccitn'Is  distant  from  ea^h  other.  An 
■Di;le  of  73  focoiids  in  aq  object  i-urreapond^  iu  the  diagram  mat  ic  eye  (see 
|>t  H94 1  to  the  lenjctb  of  5J^  /•  in  the  retiual  image',  and  one  of  AO  seooiKls 
to  3.ti.i ... 

In  the  human  eye  50  ooum  may  be  counted  alonj;  a  line  nt'iQOii  in  length 
drawn  thruu(;h  the  centre  i)f  the  yellow  spot ;  this  would  give  4^  fur  tlii^ 
disianoe  between  the  cenirea  of  two  adjoining  cones  in  tbe  yellow  spot,  the 
•venjce  diameter  ufa  cuoo  at  its  widest  part  beinir  •If  and  there  bein;;  ilight 
interva'a  between  ueiithboring  coaea.  Hence  if  we  take  the  centre  of  a 
eoae  a»  the  centre  of  an  anatomical  retinal  area,  these  aoatoTiiieal  areas  oir- 
respond  very  fairlv  to  the  phr^ioli'i^ical  visual  areas  aa  determined  ahove. 
That  is  to  tav.  if  two  pi>int«  of  the  retinal  iuia^e  are  leas  than  4^  apart, 
ibey  iiiav  bi>ih  lie  within  the  area  of  a  single  cone ;  and  it  b  Jnst  when  they 
uv  leM  than  about  4  ><  apart  that  they  oeiise  lo  cive  rtae  to  two  distinct  aen- 
•Uiam.  It  must  he  remembered,  however,  that  the  fusion  or  distinction  of 
I  the  wnaationa  ts  ultimately  determined  hy  the  brain  and  not  by  the  retina. 
[Twk  p»inis  Iff  the  retinal  image  Idu  than  4»  apart  might  lie  botli  within 
'^the  area  t>(  a  sln;;le  eune;  but  tbe  reaaon  why,  under  such  circuiustauccH, 
they  give  rise  m  one  senMllon  »idy  is  nut  because  one  cone  fibre  only  ■■ 
•timulaied.  Twu  poinla  of  a  rrtiual  iniavi'  mi^ht  He,  one  on  the  amn  of  ouo 
cone  and  another  «n  the  area  of  an  a.lJDiniiiu  time,  and  still  be  lot?  that 
4>i  npart;  iu  sui-h  a  ra«!  Ino  conn-fihrct  wouhl  be  stimulated,  and  yet  only 
OMatHMlion  Willi  Id  \i-  ]iniduc«d.  8o  also  in  the  lea  wcntilire  |>eripheral 
psrta  of  the  r<<iinii  («•>  p.iints  of  the  rMtiiial  imtfO  mi^lit  stimulate  Lwn 
CMiea  a  ooii«i<leral>]u  diMancv  apnrt.  and  yet  give  rini  to  one  senotion  only. 
In  the  CMS  where  IIm  two  pointJi  lie  entirely  within  tbe  area  of  a  single 
f,  it  b  Axeeodingly  probable  that,  oven  if  the  adjacent  cones  or  cone- 

>  Br  ^  !■  nwsDt  oi.»<tioia«a4tk  or  ■  uiUliUMtn. 


918 


SIGHT. 


flbrce  in  the  relinn  nri*  not  il  thv  Mine  lioic  MttinnlnKvl.  iniTiuliM  radiilf 
frnm  llie  ceretirni  riKlini;  of  the  exnt«l  cono  inlo  l)i«  iivigliboring  cpnrlinl 
enctinKB  of  tlic  neighlwriiig  conts;  in  othrr  words,  the  Hnsniion-nrpa  iu  iKc 
bntio  doee  out  exactly  corrarpond  to  and  is  ni>t  fJinrjily  dctintti  \ikt  lit 
reiinal  area,  but  gradiintly  mdee  away  into  n«i};hlit>ritif;  eeDMitton-ami 
We  niay  imagine  Ivo  poiiil«  of  the  retinal  image  to  tkr  apart  ihnt  rrtti  tir 
extreme  niargioH  of  Ineir  respective  cerfbnil  eeniinlion-an'a6  do  not  imicfc 
each  other  in  il>e  least ;  in  Hucti  a  cane  ihere  cnn  b«  no  duubl  about  ibe  t«« 
{>oin[a  giving  riiw  to  two  sensations.  We  niiplit.  Iiowever.  inia;;ine  a  Mcu>i 
CBie  wh«re  two  [loinU  were  jual  so  fnr  a|iart  lliat  tbeir  respective  waulii*- 
arena  ehouM  coalesce  at  ibeir  maTginb,  and  yM  thai,  in  ptBaiaK  fnioitW 
centre  of  oue  senBniioii-area  to  the  centre  of  the  other,  ire  should  find  im 
cxainiitalioii  a  cxjnHiderable  full  of  een^lioii  al  the  jnoction  of  (be  too 
iireaH :  ami  in  a  tliird  ciute  we  might  imagine  the  two  centrei  to  be  » thw 
to  euch  other  that  iu  paaiiii^  from  one  to  the  other  no  appreciable  ritabii- 
liou  of  ieuaatioD  could  be  discovered.  In  the  la^t  osae  lliere  wouM  be  \m 
one  Msnsation.  in  the  aecond  there  might  uill  be  two  Moaatioju  if  ibe  inar- 

final  fall  were  great  euou^h,  even  though  tbe  areas  inrtiallj  ooalwaA 
liiiK,  though  the  nnwiic  of  rods  and  oooea  ia  the  baais  of  dbtinct  tiaion,  the 
di*tincti(iii  or  Albion  <if  two  viaion  Impultea  b  ultimately  determiued  bv  tbt 
diMpu»itiiMi  and  (.-oudition  of  the  eerenral  ociitmi.  Hence  tliv  panabiliiy  of 
incrcaaing  by  exerci«e  the  faculty  of  dixtin'p^whing  iw>i  M-naaiiwiu,  itDee bf 
uw  the  cerebral  teiiaation-areua  teeoine  more  and  okiK'  diflen-ntiaird.  Tbih 
liowcvcr,  ia  evcii  more  atrikiiigly  HhowR  in  touch  thnn  in  aight. 


Color  SntMiionn. 

When  we  atlow  aanHght  reflected  from  a  cloud  or  sheet  of  l>nper  to  bll 
Into  the  ere,  ite  have  a  sentaiion  which  we  call  a  wnsation  of  white  li^rlii 
When  we  look  at  the  »iuie  light  through  a  prism,  and  allow  difftrmt  [mru 
of  the  spectrum  to  fall  in  Duccemion  into  the  ere,  we  have  ^DsatioDS  iiliidi 
we  cmU  noipectively  sensations  of  red.  orange,  yellow,  ^reeo,  blue,  violet,  ftc 
ligtit.  In  other  words,  rayu  of  light  falling  on  the  retina  fcive  risa  to  diStt- 
ent  MCDsntiono,  according  to  ihe  wave'lengihs  of  llie  rays.  Though  we  tpnt 
of  the  »i>ectriini  as  cuiiniatiug  of  a  tew  colors,  kuch  as  re<l,  urangv,  tie. 
there  are  an  nlinoxt  iiiliiiile  iiumher  of  internieiliBte  tiiilt  tn  the  ^WCtrui 
iLt«ir;  and  wv  pcrcHrc  in  external  nature  a  largo  number  of  eolot«.  mrhai 
purplr.  brown,  gniy,  etc..  whi<'h  do  iHit  corrrifioiid  to  any  of  tbo  color  tn- 
tations  giiiiXKl  by  rcganling  the  succi^wive  pari*  of  the  N[icciruni,  We  lU, 
bowerer.  «n  fxaininatiou,  that  certain  diatincl  coW  seoMtioiis,  not  con» 
Spooding  to  any  of  thi^  ci)l"r»  of  ihe  spectrum,  may  be  obt«iiM>d  by  the 
fbtrion  of  the  nrnoalion.*  cnuM-d  hy  two  or  more  of  lb*  prisnmtio  colon. 
Thne  pnrplc.  which  i"  nut  pm>ent  in  the  8|iectnim,  may  be  at  once  prodaoal 
by  furirig  the  «ciituiliiini<  of  blue  and  red  in  proper  pnip>'riioiM.  Monvnr. 
many  of  the  vnriouf  tint*  and  >hadcii  of  nature  may  Ih-  imitntiil  by  Aaiitg  a 
prtii-ular  color  scntuition  with  the  scniuiiioii  of  while,  or  by  allowing  a  etr- 
tain  ((uanlity  of  light  of  a  particular  color  to  fall  Rparaely  over  (he  arra  at 
ihe  retina,  which  is  nl  ihe  tame  liinc  protected  from  the  aceecw  of  anr  nthrr 
light,  i.e.,  aa  we  ray,  by  mixing  Ihe  color  with  black.  TIiuh  tbe  hmaM 
of  nature  reeult  from  various  admixtures  of  yellow,  red.  white  and  blaH>; 
and  a  small  quantity  of  white  light,  K^iieied  over  a  large  area  of  il>e  retiaa, 
t.  e.,  white  largely  mixed  with  black.  fDriiia  a  gray.  In  fact,  the  ijualitin  nf 
a  color  depend  (1)  on  the  nature  of  the  prbraatic  color  or  colon. «.  t-,cn  the 
wavfrlengtlks  of  the  onsiitueni  rays,  falling  on  a  ^ren  area  of  tbe  rvtiua : 


VISUAL  8SNSATI0NS. 


»I0 


I 


I 


(2)  oil  i)ie  nmount  of  LliU  eoloreil  liglil  witidi  fmllt  mi  Ihe  nrvn  uf  ibi^  rfliiiK 
in  a  |[iwn  linx! ;  iukI  (3)  on  the  tniouot  nf  whilv  li;;lit  fkllin){  mi  thr  iiitno 
arc*  nl  the  woe  UnM).  Whru  ray*  corr>Mi|)iiMiliii!{  to  a  prUiniitic  i^oltir  fall 
upon  llip  rclina  uDiLCO(»m|>aiii«l  hv  imy  wliili-  light,  the  color  !<  «iii(l  tii  bv 
"  Hiliinilnl :  "  oikI  n  color  in  k|hik<'ii  (if  tu  uivttv.  or  \vtf  niiliirnUil  nccordini; 
aa  it  i»  itiixiil  with  lnw  or  mori'  white  li^'liL  WbL-ii  wv  air  liil  Id  ihwcribc  a 
culur  (IN  iH-ine  "I*  s"ch  a  lint  or  hue,  w  an  ga\i\vd  hv  ihu  lirvl  of  (ho  abova 
cx>ui)itioi)».  Bill  Vic  hiivr  no  common  jihrmHs  br  wiiich  «ir  ilistineuuh  the 
aecootl  of  thv  above  ronditionii  fmtu  (he  thin).  Thv  wort)  *'  pnlu,"  il  ii  tnie, 
i*  nixt  frraucatly  utcd  to  expmM  n  color  \-orjr  slightly  ntiirnti.-J :  biK  iho 
ironb"ricli"  or  "(t«c|>"  are  iisod  fomclinii-s  aa  nwoniae  hichlj:  Milnrated, 
■ooiCtimM  u  ni*«ninp  simply  that  a  large  (lunniily  of  light  ot  the  particular 
hua  il  paMing  into  the  eye.  .So  also  witn  (lie  phm««  " bright'  ;  liiis  we 
oft«o  iiH  nbeo  a  largp  amount  of  colored  nntl  whilo  light  fall  nl  (he  samo 
tima  on  the  fame  retinal  nren,  but  we  eoioeliinc)'  alw  uw  it  to  vx]>r(«e  the 
narv  iiiteoMty  of  the  senaation. 

The  ))«■(  mrlboil  of  ru.ilii);  color  aeaMtions  b  that  adopted  br  MaKiell,  of 
alloniniE  two  iliirereiit  purL*  of  the  Bpuutruui  to  full  on  the  amui'  pui't  ur  ihc  rrtiiia 
at  ill*  Ntmi!  timt.  The  \u*  of  th«  piir<r  |iri4mai)c  colon  ellmfniilM  riror*  nliiob 
arue  wImh  pijnncnbt,  the  colorn  of  which  nrt  not  piife.  but  mixnl,  nfi-  cmploywi. 
And  wlwre  t>iKm«(iI>  nic  ut«l,  it  in  the  ■cnMliont  to  which  the  pi|;racn(ji  kiv  ri*a 
whii'h  must  be  miinl  and  ii'jt  th«  [>i|;uieiili  theinielvtii.  Tbiu  wliite  llit- senna- 
tioiM  ^in«d  by  looking  at  KAinboee  vellow  and  indigo  respFctively  when  fiiMd 
gfT«  riM  lo  a  Hnsation  of  white,  gamboge  and  indigo  thcmwlvn  when  mixed 
appear  gmn.  The  color  at  tlio  mixed  pigment  in  clue  to  tlie  fuel  that  tlie  rays 
nhii-h  reach  the  eye  from  the  mixture  are  thoM  which  are  leail  atiwrlied  liy  the 
tiro  pigment*.  The  gamboge  absorhs  ibe  blue  rnyit  very  largely,  but  ilie  green  to 
■  much  lemt  extent;  while  the  indieo  ah»orh«  the  trd  and  yellow  rii<»  very 
largely,  bill  alt"  aVuoriw  very  liiile  of  the  green.  Menco  green  is  the  predmninant 
huaofthe  mixture.  When  pure  piKmenla.  ■'.  e.,  pigment*  correajtonding  iw  cli«ely 
HiNMdble  to  the  priHmHtic  colon,  are  ujted,  utUfaelory  teaulta  may  be  HEaiiieti, 
dtber  by  lulng  th«  reOecled  Image  of  one  pigment,  aud  ariiueiiig  bo  that  it  falh 
on  tho  retina  al  the  same  spot  u  the  direct  imaici'  of  the  otlxT  pigment,  or  by 
allowing  ih'  image  of  one  pigment  to  fall  on  thr  retina  before  tbe  M'aiation  pro* 
dace<l  tiy  the  other  hai  paiM  away.  The  fir*i  mult  ii  ejwily  reached  by  Helm- 
bollx'a  MOiple  metliod  of  pincliig  Iwo  niece«  of  colored  paper  a  little  dlntanoe 
apaitoa  a  table,  one  on  ench  «ideof  aglaxipliiie  inclined  at  an  angle.  By  looking 
mtb  line  eye  doWn  on  the  glwu  plate  the  rcBocted  inijue  of  the  one  pH|>er  may 
be  oiaile  to  coincide  witli  ihc  direct  Imago  of  tbe  other,  tJie  angle  which  Ibr  Klnm 
pinie  maketi  with  tbe  Utile  being  adJnatM  lo  the  diatance'  between  the  piecee  of 
paper.  In  Ihe  hccoimI  method,  tlia  "color  (op"  is  used:  Mclor*  of  ihe  colon  lo 
be  inteotiialed  are  placed  on  a  disc  made  tt  rotate  rery  rapidly,  and  tbe  image 
of  one  coTur  ia  (bus  broagbt  to  bear  on  (be  retina  ao  toon  alter  the  imsge  of 
another,  that  the  two  itenuiiona  are  f^ued  into  one. 

When  the  Bonsstijms  corrcajKmdtng  to  Ihe  several  prismatic  cnlora  are 
fuwd  tog«her  iu  various  oocab  mat  ions,  tlie  follovriDg  remarkable  results  are 
brought  about : 

1.  When  red  and  yellow  in  certain  pro|>orliom  are  mixed  together  the 
result  is  a  iteniwlioti  of  oran}^.  luitc  iDdiBtiiigutshnble  from  (he  onin;:;e  of  the 
apcclrum  ilaelf.  Now  the  latter  is  produced  by  rays  of  certain  wnTe-lcnjrtha, 
whereas  llie  rays  of  red  and  of  yelluw  are  reajiectively  of  rpiitc  different  wnro- 
l«ngtbs.  Tbe  orange  of  Ike  tpeetrtim  cannot  be  made  up  by  any  mixture  of 
(lie  rerl  and  tht  i/dlote  of  the  ^>telrvin  in  (he  seuse  that  the  red  ami  yellow  mjs 
can  unile  together  lo  form  rays  of  the  same  wavo-lenj;llia  as  (he  orange  rays ; 
tii«  (hrte  things  are  abwlutely  diRerciit.  It  ii  iimply  the  mixed  tentalitut  of 
the  red  and  yellow  whioh  bao  like  tite  Mrtttniion  of  oraoge;  (be  inixUiiti  b 


SIOHT. 

entirelr  unl  obMlutely  n  plijViologioal  ona.  Id  ibe  ma»  wbj  we  lUf  hf 
Appn>))riut«  mixMma  produce  the  Kmstto(w(!ormpnD<tIng  to  other  parUof 
th«#|V'Ctruni.  Now  we  must  suppose  that  ra^  of  ililTcrviit  wnvi;- knjctli 
Sfive  Tim  III  iliirimiil  fenwiry  injpul*ee;  ihat.  fur  uManw,  the  u-amry  iai]H(lM 
KCuemtis)  hy  oningn  ravH  nrn  ilifliireut  rrum  thoM  gen«ratc<J  by  reil  ml 
hv  yvlluw  ny*.  Hence  we  nre  luH  by  the  fiict  or  mixoil  Kiiinli'MU  bdif 
uM-ntii'iil  nil.li  other  iipi>areiilly  itimjik  sritKntionii  to  infer  ihut  the  Momj 
impuiw*  which  iiny  my  nrigiimle*  tire  cither  theniMlvc*  ul*  b  crMiiplcs  dm- 
Mt«r,  or  )M  hitciiniiiig  mnvvrlLfJ  into  tciMntioD*  give  riM  (a  complex  or  miitl 
tci)nti<>n»;  ih^t,  Cor  iiiKtoiicc,  ihc  inipiilM  or  acnution  wbiofa  ■  ray  in  ik« 
niitMlv  of  the  ornnge  gives  ri»o  tn.  is  not  »  nmpio  impulse  or  Miitttjin 
iiii«wcniigttxclasi\'el^  to  thecolorof  thitt  rnr,  but  that  Ibe  my  ptx»  rw 
«itli<T  to  11  complex  impulM  which  bceomet  ciinvortoH  into  a  cniapkx  mm- 
tioii.  or  lo  n  iimplp  iaipiilsc  which  evenMinilr  <)ev«lo]is  into  n  mixnl  .4 
complex  tH-iiention,  into  ine  cumpwitiun  of  which  In  each  cue  other  itnop 
liniF  nml  shs'kF  of  ntl  niiij  yellow  enter. 

'Z.  Wlicn  certain  color?  are  mixed  locether  in  pain  in  oortAin  definite  |tn>- 
portionm,  the  ratult  is  while.    Then  oolore  are: 

KH  (near  a),'  nml  Bluc(5rcrn  {wja  F) ; 
Ornnge  (nenr  Ck  end  Biue  (ln-iitccn  F  and  O); 
V«11ow  <iiriir  D),  HQi)  Iiidi^'O'Blue  (near  0); 
Oreen'Yellow  (near  E),  and  Violet  (between  G  and  11), 

and  are  ntd  to  he  "  wmplcmentarv"  to  each  olhrr.  To  tboee  ml^l  b» 
add«d  the  peculior  uun-pniiriiiitic  coVir  purple,  which  with  gn!«n  abo  give* 
while. 

3.  If  we  select  arbitmrily  anv  ihrve  colom  corresponding  to  nay  tliTM 
parts  of  lira  fpcclrum  euflicicntly  far  apart— ear,  for  iustanco,  red.  gm%, 
naU  blue— we  enn,  by  n  proper  adjustment  of  the  pjoportioDs  of  each,  |ir^ 
diice  while.  Further,  iheee  three  coinn  e&n  be  taken  in  6uch  proportioM  m 
with  a  proper  addition,  if  necessary,  of  white  to  produce  the  eenaaiinns  uf  all 
other  ci>lur«.'  That  is  to  say,  given  three  itanditrd  sonsatwoB,  »ll  the  other 
MiiMlioOH  may  he  ^-aiDeil  by  the  proper  mixture  of  these. 

It  i."  obvious  JWiih  the  fore|toing  that  our  real  color  eeosUioiu  are  miKk 
fewer  in  number  than  ihuee  which  we  appear  to  huve  wlien  we  look  on  ihf 
cotoni  of  tho  ^jicctrum  or  of  nature ;  that  rays  of  li|;iit  awake  in  aa  certaia 
simple  w-nnation*.  which  n)ixe<)  in  variotis  proportions  repnxluoe  all  our  •«• 
salions.  Ami  the  oueaiion  ari»e!>.  What  in  the  nature  or  what  are  ibe  char 
acler«  <>f  thn«'  tiimpk-  ttcoHiitiriii!!  ? 

When  w(<  i-xumine  our  own  neuititlioiis  of  light  \re  find  that  certain  of  tliMe 
seem  to  be  (piile  diolinnl  in  nature  from  i-jit'h  other,  so  that  each  I*  aonotbiagi 
eui  genrrit,  wlicrens  wt^  i-iuiily  fiTngniie  all  other  mdmiJoiui  as  various  nix- 
tures  of  thciie.  Thu.i  rcl  and  yoHnw  are  to  U!t  iguite  dUlinci;  wa  ila  !>•* 
recn{;nize  nnvlhing  coninion  to  the  two;  hut  orange  u  ohvlouvlv  n  niixun 
of  red  and  yellow.  The  scnHttions  tniutieit  by  dilTurcnl  kimU  of  light  whiA 
(huB  api>enr  to  11s  distinct,  ami  which  we  may  oiieak  nf  an  "  fuuilaint'ntal  mti' 
salions. '  are  white,  bWk,  nx),  yellow,  green,  bine.  Kucii  of  thew  mwmi  10 
us  to  have  nothing  in  common  with  n»y  of  the  otlten,  wherens  in  all  olhsr 
colon  we  cnn  recogniu!  a  mixture  of  two  or  more  of  these. 

Thin  re«ult  of  common  cxpericiicofiJggc«is  the  idea  tliut  thiiwe  fuDdamratal 
Hcnoalion*  are  the  primary  or  simple  ecnaalions,  epokon  of  above  a«  tho«e  ovi 
of  which  all  other  tencaiions  miiy  be  supposed  to  be  compounded.    And  a 


I  "not  Idtcn  refer  to  Fimimnlx.fi-c*  lliin., 

■  A  Oiw  hlfkir  HiuniifO  Fi.lon  nnixii  ri>  v>  rvfrnliircil.  Mil  ■  nililoiriir  niir  no*  of  IfesaaSk 
whlNoui,  Ws  fDH) .  ivrli«».  ihrnrlbiv  'fiett  M  tlioc  hiumM-I  rrii-n  «  latlyc  "nwntiwial  If* 
iniiptiuiilllilnsllfn  nrtlm  TTiTT*«rMlrirlly  mlntint  nilnrr  wUh  Ibc loMnirMnB  ur«ait* 


921 


» 


tli«>urT  hits  h(>en  propoM"!  (o  nwMirilo  lbi>  vBrioii»  ftcK  of  color  tMod,  with 
i)iv  »iippne)(ti>ii  ihnt  we  pnmnw  lhrv»  fix  fiiii'liim^iiMl  KantloM.  This 
llicorv.  ktioMii  lu  that  of  lleriiiif.  in  fumicwhnt  m  follnvri :  Thr  *ix  M-fi«ili»n» 
readily  fall  into  three  nairv.  th«  members  of  esch  pnir  havini;  ana)<ii^ni*  reU- 
tioBs  to  each  otiier.  White  mid  btaek  nalnrnltr  pi  tojrolhcr,  the  oni;  lining 
the  nnlaf^iiifllic  or  correlative  of  the  other.  There  iit  n  niniiinr  c>nni!ic'tioii 
hetireeii  reil  and  )treen,  the  one  beini;  the  coni|>lemenliiry  of  the  oth'T.  nnd 
bptweeu  yellow  and  hlue,  which  are  aiinitarlv  com  piemen  tarv.  Wo  mw 
rcaaon.  a  tlioii  time  bark  (p.  SN),  for  believing;  that  vision  orieinulM  in 
the  cluinjiei  lakiiii;  place  in  certain  Tuiial  sulMtanoea  for  a  naunl  ■ohfllnnoo) 
in  the  r«lina.  Aud  the  (hcorv  of  which  we  are  speakini;  mippoicfl  tbiit  lh«rs 
exist  in  the  retiua,  or  at  leiwt  Momewhere  in  the  visual  apparatus,  three  dtB- 
tinct  TiMial  (iibiilnneet  which  iiri!  coiitinually  uudericoin?  a  (luiible  luiJlab- 
olbm,  one  cf>iwlfu<niri>.  of  muiinilation  or  buildiuK  up,  and  the  olh«r 
dMnictive.  of  diiwinitlnlii'ii  or  hrcnkiuv  <lown.  One  nt  thew  auhalADcei  ii 
funhi-r  of  Hiich  a  nature  ihnt  whrii  di.viinilution  in  in  exocM  of  BSMailBUao 
we  have  ■  t«-iiMif  ion  of  whit<>.  and  whrn  awniiluljon  la  In  exoSM  B  Mnsfttion 
of  black.  With  ■  itcciiml  milNttunn^  excMi  of  diMtmilnlJoii  pmvnkea  red,  of 
aminilaiioit  grr^n ;  and  uiih  tho  ihiril  oiibstance.  yclt'iw  and  blue  rMpect- 
ively.  Wbnt  in  th«!  lallvr  two  ntjliatancaw  dtMiniilatton  and  a:«imiliLtiikn  are 
exactly  equal,  no  rlfcct  i#  |ir>Mluccl :  hut  ivith  thr.  fir^t  Milwlamre  thin  oin- 
dilinii  pnxluna  in  ua  tli*  aflbct  of  gmr.  Furtht;r.  thc«c  HulistAiicc*  are  of 
Mich  a  kind  thai  while  the  first  or  whitr-blm-k  *ul»taniT  in  influenced  by 
ny  ahing  the  whok  rnngc  of  the  siwctniro.  the  two  other  wilinlnijcen  are 
difliTttntly  influintnt  by  mv*  of  different  wave-length.  Thw*  in  the  jwrt  of 
tlw  aptdroni  which  wo  call  red.  the  rays  promote  n  rapid  di<t>!mihii'>n  of 
tin  Rd-green  «iib«t«i|oo  with  com  pa  rati  rely  vlieht  eflecl  in  either  dirMlion 
on  the  Tcllon-hhie  aulistance;  hence  our  aeDsalion  of  reel.  In  that  part  of 
the  apc^niiu  which  we  call  yell.iw  the  rays  effeot  a  marked  dis*inii]ation  of 
lh«  yellow-blue  titbaisnre,  but  their  action  on  the  re(l-Kre*n  substance  if 
equal  in  tite  directi»n  of  both  awimilati<>n  and  dMsimflation  :  hence  our  sen- 
wtiun  of  yelUiw.  The  itrcen  mn.  axaiu,  promote  aasimilalion  of  the  red- 
green  Mibsiance.  leaving  the  ajatrntlation  of  the  yellnw-blue  nuWanee  eiiual 
to  the  diMimiliiiiou.  and  aiinilarly  blue  ray*  cwnae  aniinilation  of  the  yclhyw- 
blue  sulMlancc.  and  leave  llic  rvd-irn-cn  nnbitlnncc  neiitnl.  Finallr  at  tlie 
extreme  blue  end  of  the  uporlrum.  the  rayn  once  more  provoke  dtK<imilatii>n 
of  ilie  ml-graen  suhKlanire.  When  omngi-  rarx  fall  on  the  ritinii.  there 
ia  an  exccM  of  disiiinihition  of  l>nth  the  red-grren  and  the  yellow-bltie 
•ufasUnre;  when  greenish  blue  ray»  are  ncrreiwd  tborv  is  an  exec**  of 
Maimilaliun  of  Ir^h  thftic  tub<tanees:  nnd  other  ini«rmediale  tintn  com-' 
apond  to  variable  amounta  of  disiimilation  or  animilntion  of  two  or  moi«  of 
tltCM  Hubttniicc*. 

When  all  the  rav*  together  fjll  on  the  rctinn.  the  red-green  and  yellow* 
Idut  vulMtance  remain  in  equilibrium,  but  the  white-black  auhitium  Ii 
v(oI«ntlr  di«>imilnie{l ;  and  we  say  the  liiiht  i«  white- 

Anotltcr  ibcorT  ( known  a«  the  Young-Ilelmholti  theory,  beeaiiw  it  WU 
intnxluiTil  by  Young  and  more  fully  elaborated  by  Helmholtx)  strirci  In 
rodui^p  the  matter  V*  still  further  »impliciiy.  Starling  fVum  the  fact  men- 
lk>nci|  a  Fhort  tinie  since,  that  all  co'or  sensations,  including  the  sentutlioti  of 
whil<\  may  be  obtained  by  the  apprt>printe  mixture  of  thr««  standuni  iicnin- 
tioiiH,  this  theory  leacha  that  our  visual  apparatus  ii  m>  eonsliluteil  a-*,  wheii 
excited,  to  give  rise  1"  three  primary  senaationa.  and  that  these  primary  aen- 
aaiions  are  called  forth  in  diffi^rent  degre«a  by  diflereni  ray*  of  light,  •»  that 
each  ray  givea  rise  to  ■  dilfereot  mixture  of  the  three,  ^veral  aetn  of  thiee 
■neb  (irtmarj  seuantiom  might  be  cltoaen.  which  would  wliafy  the  oondiiiiH 


BSS  SIORT. 

of  ^viiig;  Hm,  by  npproprialv  ntixturc.  Ut  all  soBMiiona  n(  vnlor,  includiBi 
wbiU:;  bul  for  rmwtiu  into  whii-h  wc  catiix)!  enter  fully  hero,  tbe  SKimigM 
which  mik}-  thii»  be  tukcD  »  priinnry  seiistuioiiit  aitpear  to  dfrnwpoad  bi  tm 
•enwittonH  of  re<l,  gmn,  ouil  blue  ur  viulel.  Such  n  mw  uf  three  (trimiT 
cukir  wnvntioiu  it  repraaonted  in  the  dingraoi  (Fig.  233).     Tbiie  llie  m 

rra.  at 


^ 


I 


X  0  f  i-i- 

VfOMikm  or  Tunc*  f'KlHlR^  v 

ll«lhP(D-r«lIi?4"i«d.~  :"K'W"/'  ■ml  a  "  dclut "    n.  'Uilan      S.  O.  r.  ct&.  nfil* 

•inC  IhetTd.  unnic.  ftllow.  r[c.,  wlor  oT  Ibe  ii|«rtmm.  uid  Uic  dlavum  •hmrt  bytW  btlrklrflli 
citnain  cavh  i-nv,  ■■»  wlul  cileiil  Um  wvurkl  |«liiiArr  tulot  MOMltsa*  on  Tt>|<aiatvlT  «MIM  tf 
TlbmUou  ofilllhivul  ■■Tc-lvugllu. 

prioiiuy  wnMUion,  cxcitcil  to  a  cbH^  extent  by  the  nr*  *t  ihf  vxtrrnic  ml 
VD<I,  it  mtM  powtirfully  oBbcted  by  lltv  nivs  lU  n  liltlv  di«tiincr  from  the  vat, 
tJio  rays  from  this  point  onward  tuwiird  tin?  blue  end  producing  lev  aail  hs 
eflect.  The  curv«  of  the  green  primary  eensiition  begins  later,  sad  reaeha 
ile  ntaxiiDum  in  the  green  of  lli«  epet-irum,  while  the  blue  or  viulet  primarr 
MDBnlion  IB  Blill  later,  am)  only  reaches  iu  inaxinmin  totrari!  the  blue  end  it 
l)ie  e{H.'clrum.  Each  ray  euth  furtb  eucb  sensaliuii,  bul  in  a  ditlereut  dccRC, 
and  ibe  lulnl  reault  uf  each  lay.  or  •.('  each  group  of  rays,  is  deti^rniiiMU  bj 
tJte  proportionate  auinunl  of  the  three  eeuaalioiis.  Thus  the  aeoMtiaii  A 
orange  (O  in  the  ligiira)  is  brou;;ht  about  by  a  mixture  of  a  great  deal  tf 
the  primary  nn]  with  inucli  lew  of  the  primary  (trwn,  and  haixlly  any  oftk* 
iriinarv  blut!;  the  »rung«  oc-iiMlitin  is  converted  into  a  yellow  •«nMiliati  lif 
iminisliing  tl)e  primary  red  and  largely  increasing;  il>e  priomry  ;;rr<rn.  thl 
pritoar}'  blue  unitergoin^  iiUo  sunit;  dli((ht  increase.  And  uniilur ly  with  all  Ht 
other  (cnnt ions.  When  ench  uf  the  primary  Memotiona  ia  excitet)  lo  a  tiiasi- 
rouin,  a»  when  ordinary  light  falls  uu  the  retiua,  the  leault  ii  a  artyaliua  of 
nbiie.  Atvonling  to  this  theory,  block  is  Bim])iy  (he  abtencc  of  i)inTiiiii 
frriRi  the  vituni  nppiiriiluK. 

In  the  view,  as  urigtnallv  put  forward  by  Young,  the  three  primary  no- 
aations  ncrc  suppowu  to  )»  reiirrH-iilcd  by  three  m.1*  of  Bbr«a,  encfa  m4  of 
Hhree  being  dirtcrrntly  allcctcd  Ly  ditllrent   reyii  of  lii{hl.  and   the  impulHl 

SitBsing  to  the  brain  along  each  »ct  a»akoniiig  a  diiitiuct  teoMtion.  No  such 
Mlinclioti  of  fibres  can  be  found  in  the  retina ;  bul  an  auatomicnl  boiit  of 
thi»  kind  is  not  neecamry  for  the  Lhcsiry ;  we  can  ewily  eoDoeive  of  iheMiw 
librr-  transmitting  three  ili«tinct  kitt'U  of  impubea;  or  we  uty  supfMee  thai 
thv  visual  lubstancw  are  three  iu  number  instead  dfxix,  the  cnongee  in  Mwh 
Hulntanco  proroking  a  primary  wnsatiun. 

titich  are  the  two  nmin  theories  of  color  vinon ;  and  miieb  may  be  mU  ia 
tavoruf  both  of  tbom;  at  the  same  time  both  of  tliem  prevent  raanv  diffleal* 
liea.  To  diacuas  litem  fully  is  a  task  beyond  the  limita  of  this  booV.  and  lo 
discu.«  them  in  any  but  a  full  manuer  would  be  unsatiafacUiry.     We  muiI 


S 


I 


I 


iti*8cd,  tkcrrrfore,  witb  l!i«  furring  simple  stnl^'iiirni  nf  tin*  mo  twms- 
TtHlefMlDdcDll.T  of  any  thcon-,  however,  we  mny  remciiit*r  1 1  t  ihfll  nil  tliu 
MMiMili»iii>  wliicli  Kc  nxjwricDov  uihIpt  the  sclioii  i>r  light  of  whnii-ver  kind 
amy  hv  ri-<liicc()  to  sii,  while,  binck,  rrd,  vdlow,  gr^o.  nid  blue  :  nitd  (2) 
ibit  ibcar  m«y  Iw  all  rrprrMlnced  by  various  niiiKurM  of  three  •liinilard  mu* 
MlioilR,  if  bluck  be  alhtwitl  to  indicate  tbo  absence  of  all  wiHstion.  Thmo 
»tt  nintlrreof  fact,  whal  ta  nl  present  ile baled  is  whether  the  six  rundnmrDial 
■Biintions  are  the  outennie  of  l.hree  primary  censalioiis  or  whether  they  rcpre* 
wot  lix  diitiiiet  conditions  of  the  visual  apparatus. 

Chtor  hiiuilneit.  Persons  vary  niueb  iii  ibdr  power  of  BpprecKitin^  sn<l 
discritninaliDg  fiolor,  »'■  «,,  in  the  inleusiiy  nn<t  accuracv  of  ineir  color  »en«a< 
lions:  and  »onie  peonle  reKanI  a^  similar,  t'olun  which  (o  ninst  people  arc 
i;larin;;ly  dirtiiid  ;  tliese  taller  are  i>ai<l  to  he  "  color-bliud."  The  most  com- 
mon form  of  cilur-htioduess  is  that  of  (wrsooH  unable  to  diiUiuKuish  j;rcen 
aD<l  red  from  each  other  As  iii  the  case  of  Daltim.  ther  tell  a  red  gown 
lyinn  <«i  a  (jre*"  Ifraw  plot,  or  a  red  chernr  aumu):  the  ([r*eii  leaves,  by  its 
foru),  and  not  by  its  color.  Tli«y  confound  nol  only  red,  green,  and  wrlain 
rorma  of  brown,  hut  also  rme,  jiurplt^,  utiil  blue.  Such  |>erso»s  ure  oflcn 
vpoken  of  oa  "  re<l  blind."  On  the  Herin);  theory  ihey  lack  the  red-icrcen 
visual  substance  :  bene*,  nil  t)ie  color  lu-nwitionii  tbey  piiaMW  must  he  lliose  of 
yellow  Hud  blue  fre^l  from  all  mixture  of  nil  ur  ftrceu;  and  such  ai-counts 
as  have  li«en  itivi'ii  of  their  »cnsuli»ns  by  those  pi-nons  who  are  "red  blind'* 
in  one  eve,  but  piMtn*  normal  vi»iun  with  the  other,  acconi  with  tliw  ronclu- 
■jon.  On  the  Young- Hetinholii  theorv,  «uch  persons  Invlc  the  priinnry  red 
MDMlion;  and  bdico  tbo  femntious  wtiicb  thev  have  miiri  be  niixturta  of 
grwn  and  blue  alone,  our  yellow  appearing  to  ihvni  n  bright  ^r«cn,  and  our 
gnrn-bluc  a  kind  of  gray. 

All  such  red-blind  peupla  ought,  on  either  tlieorr.  to  be  len  aifeded  thao 
are  persons  with  nonnal  eves,  by  the  red  end  of  the  spectrum ;  this  ought 
with  (l>ein  to  be  •bortenea  and  obscure.  In  a  certain  number  of  persons 
who  confound  red  and  green,  this  b  the  case ;  but  in  aoroa  instances  no  such 
lack  of  appreciaiitinuf  the  red  end  of  (he  spectrum  can  be  aacertained.  Kuch 
esses  have  lieen  suppcaed  to  be  t-r^n  blind,  ibat  b.  lacking  the  primary  sen- 
Mliuti  of  Ereen.  According  tit  the  Ueriiit;  rhei>ry  >;re«o  blindness  apart  from 
retl  blindiifw  bimpooiible,  the  only  two  piMeible  color  defects  being  rc>i*);reen 
and  bltie-yellow  bliuducw.  And  ihe  exbienee  of  dblioci  green  blindness 
faaa  been  held  to  cotiinidkt  that  theory.  On  the  oilier  hand,  the  Ilering 
theory  admit*  the  pomibiliiy  of  total  color  hi  indm-M.  ■'.  e.,  ihe  inability  lu  see 
anylbinir  but  white  and  black ;  and  thim.  on  the  Yuting  HelmholtE  theory,  U 
impomibUt,  *iuoe  for  viii-m  t»  exist  at  all,  oue  of  the  throe  pnuiary  iwtisations 
muit  l)c  prMH'nt ;  n  man  to  «ee  at  all  must  aee  things  in  various  shades  o( 
(itbitr  rvd,  or  of  ^rren,  or  of  viidet,  though  he  mav  confouml  this  sinKlc- 
eolONd  vioion  with  the  normal  vision  of  white  of  didtrrnt  inienstliea.  Bui, 
indeed,  n  full  examination  of  color- blindnras  ratlier  increusva  tbati  diminisbea 
the  difficullies  of  deciding  Wlwetui  the  two  rival  theories.  * 

Injiuimce  of  the  piffmeiil  of  the  ^Uow  »fiol.  In  thi>  macula  lulea,  wbidi 
(MM  of  tbe  retina  we  um>  chiHly  for  vision,  images  fulling  on  other  jMrtx  of 
ihp  rrlina  bting  wiid  to  give  riw  to  "  indirect  virion,"  the  yellow  pigment 
■ImoHi"  some  of  the  grccnishbtue  rayii.  Hcnoo,  the  Mnsation  which  we  re- 
ceive from  objects  which  wo  art-  in  the  hnbil  of  calling  white  i«  that  whidi, 
if  this  pigiuetit  were  absent,  wc  should  receive  from  ohipcl*  more  or  l(w  yel- 
low. We  may  use  thb  feature  of  tliti  yellow  xpot  for  the  purpose  of  mnking 
ibe  S|iot,  so  to  speak,  rinble  to  onnelvn*.  by  an  experiment  euggcHt<i|  by 
MuKwell.  A  solution  of  chrome  nlum,  which  only  triinsmits  rod  and  grem- 
i(b-blue  rayv,  it  bdd  up  between  the  eye  aud  n  white  cloud.     The  greenbh- 


tm 


BIODT. 


blue  myt  ar«  alMurbeil  by  tk«  yellow  sji<it,  ami  here  the  liifbt  ifittt  riae  la  a 
MliMtiaii  of  red  ;  wheroiu  in  C\)t  ml  i>{  tbft  field  of  viaioii.  ibe  Mosuim  « 
tliKt  onlioiirily  iiroducuil  by  ihv  piirpltih  solution.  The  yellow  spot  MCOBK- 
<|U«iiLl3r  Dtnrkuil  oui  u»  »  riMy  jintch.     ThM  very  Ktna.  buwerer,  ai««  ftWay. 

In  sptflkin^  urMiiiuition  lu  a  I'oiictinn  i>f  tliu  riiitiiiiu*,  p.  !)15,  we  nfetn<\ 
t(i  wbit£  liglit  i>iily:  biil  the  dilTcruut  oi>]ur*  urv  tincuuiil  la  the  reUli4U 
biinui  by  thit  tnlviixily  »!'  ihti  utiniiiliin,  to  the  amauiil  of  AOiutitiuD  proilaeel 
Thii*  iJie  lann:  rcfrnn^biv  bliut  nyt  procljoe  K  winwtioa  more  r«ia<li1y  ihin 
thii  jolloiv  nr  rdl  riijA.  Henco,  in  dim  lighu,iu  th>wB  of  evening  nu>l  oiiMa- 
ligbt,  the  bluet  Drupnnili^-iiv,  itml  the  ti^U  iinH  yellov*  arc  le»*  olivi'iiis.  Sr 
ftlnQ  u'hm  a  UekW-mjili  i«  viitwcil  tbrougb  a  yvlloiv  glim,  the  yellow  hue  Wf 
gi-siA  to  the  mind  bright  sunlight  ninJ  auniiner  •toiktber,  ailbimgh  tlie  acwal 
illiiniii)nli«n  which  reaches  the  eve  i*  dimini^hoil  by  the  gloM.  C>iiV«rMlir. 
when  the  e-jino  kad^i-itpe  i«  vioiceil  through  u  bliio  glius  the  iilvn  of  miioDlisil 
or  winter  ie  tuggesk-d. 

The  iheiiry  ol*  three  printnry  color  wnsattons  mny  bo  usol  to  explain  wliy 
nDV  coliired  light,  if  iniidu  BuHieiently  iut«o»e.  appears  white.  Thii*  n  riultl 
light  of  iDodenite  intensity  npiieiirs  violet  bocAiise  it  e]ccit4»  the  primary  Mn- 
Balion  of  violet  much  more  thiin  ihiisu  of  green  and  rod.  If  thu  slintului  ha 
inerejised  the  mosiitium  of  violet  stimulation  trill  be  reaehed,  while  tbe«U*0' 
latioH  of  green  will  coutiauc  lo  be  In^-reaKd  aod  even  that  of  reil  In  ■  slij^t 
degree.  The  result  will  be  that  the  li;rhl  apjieitn  violet  niixe*!  with  gTMO. 
that  is  blue.  If  tbe  BtimuluB  be  Mill  t<ii'th«r  inereosed  while  the  f;reeii  and 
violet  are  bi>tb  excited  [o  tbe  iiiaxiniiiiii,  the  red  atimulatiuu  mar  b«  increainl 
uniil  ilie  rt-tiult  U  viol^i,  greea.  aiid  red  iu  the  pruportioua  whteb  malu)  wUlt 
light.     And  s>  with  li;(hl  of  other  colora. 

After- imiige*.  We  have  alreadv  se^u  that  in  virion  the  sensation  ImK 
much  longer  than  the  «tiniu)ii:>.  Under  eeniiiii  cireum.ilanccri,  iiueh  a»  p■^ 
ticular  C'luditiim*  iif  the  eve;  aa  inli-ii-te  *tiinulu*,  etc.,  the  acnv^tiim  it  m 
pmlongi-d,  that  it  is  ypokcn  of  n«  an  nfu-r  iniii/u.  Thut,  if  the  evi'  b«t  tllrecteH 
to  tlic  NUn,  ibe  imn^  of  ihnt  hi>dy  is  prcM^it  for  u  Itxig  whilv  itfter ;  aixl  \S, 
<tn  varly  waking,  ine  eye  be  dirccteii  to  the  window  fur  an  in.itaiit  guid  then 
vl'ifCfl,  nil  iiuai^i-  of  tbe  window  wiib  ils  brighl  ikioi.'ii  and  ilarkfr  «a<h4.  thi 
vari'>iis  parts  being  of  the  same  color  as  the  object,  will  remain  fur  nu  Bpfr» 
dable  time.  These  images,  which  are  simply  continuatiovs  of  tho  sodMUioa. 
ftre  spokea  of  as  potitive  <i)Ur-iinaoa*.  They  are  best  aeon  after  a  awmeatsry 
wiiiosure  of  the  eye  to  the  slimulus, 

VVhen,  however,  the  eye  has  boon  lor  some  time  subject  to  a  stimulus,  the 
aeusatioii  which  follows  the  withdrawal  of  the  stimulus  »  of  a  ilidoroDt  kivl: 
what  H  called  a  neijatine  aflfrimaiff,  or  n^galivr  tinijre,  is  pruducod.  If.  »&»f 
looking  sleadfaslly  at  a  while  patch  on  u  black  gri>uu<l,  to*  *y»  he  turned  Is 
a  white  ground,  n  );ruy  |Httch  b  seen  fur  some  little  lima.  A  olnck  Datch  <m 
a  white  ground  similarly  gives  rise  on  a  yray  ground  to  a  uegatiw  imagsffl 
the  form  of  a  white  patch.  Thi«  may  be  eX|dnitR'd  as  the  result  of  exltaot- 
tion.  Whcn'the  white  patch  htis  been  looked  at  steadily  for  SOnM  time,  \it$ 
part  of  the  retina  on  which  the  ima<;e  of  the  pntch  fell  beixmos  tired  :  h«aM. 
llie  white  light,  coming  from  the  white  ground  siibjeriueiitly  Uiokei)  at,  which 
falls  on  this  part  of  the  retina.  d.>ej  not  produce  »i  much  seuMtioQ  as  in 
otl>er  parts  of  the  retina  ;  and  ihu  ima-;e.  c  lo^e  jueutlj,  appean  gr>«y.  AnJ 
•0  in  the  other  iu^tance.  the  whide  of  the  retina  is  tirea,  except  at  the  patch; 
hare  the  rettua  n  for  a  while  man  seoiiiire,  aD<l  lienee  the  white  negativt 
image. 

When  a  red  patch  fs  looked  at,  the  negative  image  is  a  green*blue.  that  u. 
the  color  of  the  negative  image  la  complementary  to  that  of  tlie  objeot.  Thai 
aUo,  orange  produces  a  blue,  green  a  pink,  yellow  an  indigv-blue,  oagaliti 


» 


I 


nnsf!«,  iind  so  nn.  Tliis,  loo,  can  be  exjilBinof)  ns  n  mult  of  exhauUion  on 
either  liriMlbettis  of  color  vifion.  When  the  colored  patch  it  limked  aC.  one 
of  llie  itir««  jiriniary  color  ecttsationa  h  niiicb  cxlinutitd,  ami  ihc  ii<her  Iwn 
leu  au,  it)  vKryiiis  proporiioos,  according  to  the  csaci  natuic  of  the  color  of 
Ibc  |«tcb ;  and  Ine  less  exhauBied  Moeaiiona  become  promineut  iii  tli«  afrer- 
imatt^.  Thus,  tli«  red  jialch  eiliauels  lli«  rrd  fcDfatiun,  and  ibe  negative 
imaxe  ia  made  ui>  chiefly  of  green  and  blue  aeunilionF,  tbal  is.  appears  lo  W 

Cnh-blue,  ur  uluttb  Kreen,  according  lo  the  lint  of  the  red.  Oa  the  other 
ilbeiia,  «e  ins;^'  luppoee  that,  owing  to  Uie  continned  eifect  of  lookiue  at 
ifie  red  patch.  diFxiniilaliou  of  the  red'){re<'D  auhatance  becumea  len  aud  Tcm, 
lemdiu^  to  a  pnimioeoce  and,  indeed,  to  an  actual  iDcreaae  of  tbe  proccaa  of 
nfr*iuiiiaii<in  ol  tbe  name  lubaiauce;  h<-n<«,  ibeteiiMitiou  uf  green  dominating 
in  ihr  nrfTiilive  iinaire. 

SioilUrly,  «beii  the  eve.  after  lookiii);  at  a  colored  |«[ich,  is  turned  to  a 
colored  gruoud,  the  efli-cia  may  tuiily  hv  explained  by  relereuoc  to  the  cum- 
parsiire  exbauatioii  ul'  ilie  cnliir  peiieatiima  rxciied  br  ihe  jMitch  and  the 
ground  re)>{)eciively  ;  if  u  yelton-  gnmnd  be  cbiit-n  after  lunkini;  at  a  ^r«vu 
object,  the  aegntire  imnge  will  iip|ieur  nl'  n  reilii(>h  yelluw.  and  *ii  uo. 

The  theory  of  three  primarv  KnrntiutiH  dn«-n  not  to  readily  ex[>lain  why 
tifK*l>ve  iiuagei  nhould  ninki;  tm-ir  apjicnranco  without  nay  >ul  tieifiienl  Mimu- 
latioii  of  the  relitiB.  When  the  eye*  nre  tliut  and  all  nceew  n)  liuhl,  evt-ti 
ibroMgh  ibc  eyelid*,  carefully  avuidcd,  tb«  field  uf  vi»iou  i*  not  abtulutcly 
diu-k  :  there  ii  *till  u  iKiiHtioo  of  light,  the  •u-called  "  proper  light "  of  iIk 
retina.  Ifa  white  patch  on  a  black  ground  be  looked  nt  tor  «oni«  time,  and 
lh«  cyca  then  shut,  a  negative  ^black)  image  of  ihc  ajwl  will  be  Men  on  th« 
grouitd  of  the  "  proper  light "  of  Ihe  retina,  having  in  its  immediate  neigh- 
EnriHod  a  ijiecially  briebt  corvtiii.  iyo.  alM>,  ir  a  window  be  looked  at  and 
lb*  tjtt  then  clorcd,  iTie  pmitive  afler-iniafic  with  bright  jmiirs  and  dark 
Miches  gives  rise  lo  a  ne^ativo  alter-imsge  nilli  hright  sastiefl  nod  dark  panca; 
and  similar  eflecis  appear  wiih  culora.  I'hcc^  and  amiUr  facte  have  been 
largely  u»rd  in  support  of  tbe  Uerinj;  tfaeurr.  When  the  eye  has  been 
looking  at  red,  and  to  has  raUMd  diiainitlaliou  of  llw  red-green  substance 
mere  re»l.  as  on  thutiing  the  erts,  favurs  as»iniiIntion  of  the  same  substance 
and  thus  leads  to  a  aeniuition  iif  green.  And  tbe  rbylhuiio  oscillations  from 
one  color  to  its  correlative  and  batk  again,  fre<|uentty  obeerved  under  theee 
conditions  aud  irbich  puint  to  asimilatiuii  and  Uiafeimilntion  alietnately 
ffmiag  the  upper  band,  are  nut  witbuutanalogiea  in  other  commoo  iuataocee 
uf  {iroiDplaiiiiie  metabolism. 


VnOAL  Pekceptioxs. 


I        Hilherlo  we  have  studied  fenfaiions  only. and  have  conndercd  an  external 

'    object,  fueh  ea  a  tree,  a*  rimply  a  aourct  of  «o  many  dtttinct  •ensntioiii*, 

diflering  from  each  other  in  inicn»ily  and  kind  (color).     In  Ihe  mind  theia 

eviisatioiu  are  ooordinalcti  into  n  pcixeption.     We  are  not  unly  voiHCtoua  l>f 

a  number  »r  «cnsaiions  uf  bright  and  dim  lightv.ofgrem.brunn,  black,  etc., 

but  tJicM  M-HMitiuDs  are  so  rclatetl  to  each  other  and  by  virtue  of  eeRbrai 

Moctwie  m  fashioned  into  a  whole,  that  we  "  ew  A  tree."     Wo  aooaeUnee,  in 

lUwtntion  of  such  «n  effect,  speak  of  an  image  or  picture  in  tb*  oiIim)  cor- 

KHKniding  to  the  phvbicnl  image  on  the  retina. 

E        When  we  look  upon  the  external  world,  a  variety  of  imagee  are  Ibroied  at 

'   tbe  aame  time  on  tbe  retina,  and  give  rise  lo  a  number  of  contempMWWoua 

visual  sensations.     Tho  sum  of   thc«c  sensations  eonetilntea  "the  field  of 

viaioo,"  vhieh  varies,  uf  voume,  with  every  luovemeni  of  tbe  eye.    Tliie  field 


926 


SIQBT. 


(if  %'ifUMi,  bein^  id  ranlilr  an  iiegrvgatc  of  tramionfi,  is  of  omirM  «  mijttliwi 
nmUor ;  biit  we  arc  in  tlici  hnbit  of  uHDg  ih*  nme  phrase  to  denote  ih«  Mm 
of  cstemul  objvcts  which  give  Hno  to  the  wgregat«  of  vi<ual  semttiuiu;  in 
common  langutti^  the  field  of  viatoD  is  "  alllhiil  we  can  Eoe  "  in  iinv  (raaib<« 
of  ihc  eye,  and  wc  have  n  field  of  VMon  for  csch  eye  separately  and  for  th« 
im)  «ym  combioed. 

Using  for  the  present  tbc  ironia  in  their  Bubjevtive  Benae,  w«  may  renark, 
(hat  we  are  nble  to  neaigo  lo  caeh  conatititenl  ^Titration  tta  place  aiDoag  Uw 
nggrei^Rlc  of  senaatiooa  const i tilling  the  field  of  viaion  ;  we  can,  aa  we  Hf, 
toealiie  the  senaalion.  We  chusiiv  n'liether  itbelooga  to  (what  we  regard  ai) 
the  right  hand  or  leA  hand,  the  upper  or  the  lower  port,  of  the  6eUI  «( 
viiion.  We  are  able  to  disliogiiish  the  relative  poeitiona  of  any  two  diaiocl 
senaaltona;  and  the  relniive  pusitions,  together  wiih  the  relative  inteuilio 
sud  qualitM  (oolor)  of  the  Benaaiiona  arising  frifiii  any  i>hje<Tt  determiiw  our 
perception  of  the  object.  Il  need  huriily  be  remurke^l  that  this  lucalitatMa 
IB  purely  aubjective.  We  simply  determine  the  p<»idoii  of  the  M/uarion  ia 
ihc  lieli]  of  rikion  (which  is  itself  a  wholly  tuhjective  matter) ;  we  do  not 
deleroiiDe  the  pi»ilion  of  the  oijKf.  The  cuniieettoo  botwevu  the  jioikim 
of  the  object  iu  the  external  world  and  the  iKwiilon  of  tiic  Mnmtion  in  tha 
field  of  vision,  cannot  be  determined  liy  visual  uboervatimi  alonr.  All  tb» 
inlbnoalion  which  can  be  joined  bv  the  eye  is  timitci)  to  tbe  field  nf  virion, 
iind  provided  that  the  relative  pnsilion  of  ihe  wnxnitiuis  iii  the  fivM  of  vixnii 
reiaained  the  kame,  the  actual  p<»itioii  of  exiunial  nbjccu  miglit,iufiuH 
tUod  is  ooncenicd.  be  chikuited  without  our  bciiijc  airiire  of  it. 

Asa  matter  of  fact  the  lield  of  vimon  in  one  im|M>rtant  gittrticuIaT  ika 
not  correapond  tij  the  field  of  external  oinects.  The  inittgv  on  ihr  rrtina  if 
inv«rtMl;  the  mvH  of  light  proceeilinj;  <r<ini  an  object  which  by  touc^  «i 
know  to  be  on  wlial  we  call  our  right  hniid,  full  on  the  lefthund  »i<Ie  uf  tht 
retina.  If.  therefore,  the  firld  nf  viiiion  currcMtHindcxI  to  the  retinal  inaM, 
the  object  would  be  aeen  oti  the  lef^'  hnnd.  U  c,  hoirever,  see  il  on  the  ri^ 
hand,  bceanse  we  invariiibly  aiuiociate  right-hand  tactile  localiutiuo  aitk 
left-hand  visual  looilixiition  ;  thai  ii  to  wr,  niir  lield  of  piston,  nhen  inur- 
pretcd  by  touch,  is  n  re-inver»i»n  of  the  reiinnl  image. 

The  diraeosions  of  the  fichl  of  vision  of  a  single  eye  ar«  abntit  146  Afgna 
for  the  horizonlnl  and  lUO  degrees  for  the  vertical  meriilian,  the  former 
being  distinctly  grenler  than  tho  latter.  The  lioriiontal  dinieiision  of  lb* 
field  of  vision  for  the  two  eyw  is  aboni  11*0  degrees.  By  moTemenin  ii("  the 
ejfcf,  however,  eveu  apart  frum  those  uf  the  bead,  tiw  utent  may  be  coD' 
siderably  increased. 

The  satinfactory  perception  of  external  objects  re<)uirea  distinct  tUm; 
and  uf  this,  aa  wo  have  already  said,  the  formation  ol  a  distinvl  Etnagt  mi 
the  retina  is  an  caeeotial  condition.  We  can  receive  visual  sensation'  uf  all 
kinds  with  the  moBt  imperfect  dioptric  appamtus,  but  our  pnrceptioo  of  aa 
object  is  precise  in  proportion  lo  the  cleanieaa  of  the  image  oa  th«  ntina. 

Rtgion  of  distinct  niti'iii.  If  we  take  two  pointa.  nieh  at  Iwu  bJack  iatk 
only  just  so  far  apart  that  lliey  can  be  seen  disiinelly  as  two  wbu  ptacii) 
near  the  axis  of  virion,  and  then,  keeping  the  axis  Bxed,  move  i)i«  two  mfiui 
out  into  the  circumferenlinl  parts  of  the  field  of  tIbod,  it  will  Ix-  fonnii  llial 
the  two  soon  apjfear  as  one.  The  two  sensations  beeome  fiin.tl.aii  ihvy  wwM 
do  if  bnmght  nearer  ti>  each  other  iu  the  center  of  the  field.  Thu  funhn 
away  fmni  the  centre  of  the  field,  the  further  apart  must  two  pi>iDt«  be  la 
order  that  ihey  may  be  seen  ns  two.  In  other  ironb,  visioa  Is  much  mart 
distinct  in  the  centre  of  the  lield  than  lowanl  the  dreuniferetice.  Pradi- 
cally  tli«  region  of  distinct  vision  may  be  said  to  ho  timilnl  to  the  macuU 
lutea,  or  even  lo  the  fovea  centralis ;  by  continual  aiOTemeiila  of  the  eye  ire 


» 


lire  comlnntlr  bringiiig  nny  object  nhidi  vc  niih  (o  mc  ia  mrh  b  po«iiiuii 
thst  lis  itns^  fftlla  no  ihis  rcjiiou  of  tlic  rotinn. 

The  diiiiinutiun  of  diHtmcln«»  does  ui)t  lukc  plucr  c<)iinlly  frum  tli«  ct'iitro 
to  the  eirciimlereiK-'e  nlong  *ll  ni«ridian>.  Tlie  outline  di'schbed  \ty  a  line 
uniliiic  ihv  points  where  tvo  spots  oeaM  to  be  ttca  ns  tn'u  nhcii  ii)ov«tt  alunj; 
di6ei«Ri  rami  from  the  centre,  ia  a  very  irrq;"'"'  figure. 

The  seoMtioDB  of  color  are  much  more  distinct  in  the  centre  of  the  retina, 
tban  towsrd  the  circumference.  If  the  visual  axis  be  Bxed  and  a  pi«ce  of 
colored  paper  be  moved  tunard  (he  outside  of  the  field  of  riaton,  the  culur 
tinderp'ea  cbanfrn  and  ia  eventually  lost,  red  disapitearinj;  llru,  and  blue 
1a»t,  the  objwt  renmininH  visible,  though  with  very  indistiurt  ouilinei.  when 
tt»  »>lor  can  be  no  Um^r  recoitnitied.  A  purple  color  bec<>itie#  blue,  an<l  a 
riitie  color  n  tihiul)  nbit«.  In  fact,  t  lie  re  seems  to  be  a  certain  aiDount  uf 
r«d-bUndi>e«*  iu  tbe  |>eri(iheral  parts  of  all  retiuHS. 


Modifieit  Pentptiont. 

Since  oar  perception  of  external  objects  b  bued  on  the  dinlinclntM  of  the 
misations  which  so  to  form  the  pcrci-cition,  it  might  be  cxiwlcd  that  when 
ao  image  of  an  object  it  formed  on  tntr  retina  ine  Mmitory  iinjmlM^  would 
coiTMpond  to  the  retinal  imii^,  ihv^  •cuMtlionN  cirntponil  to  the  sensory  im- 
pubnanil  the  i>crccpt)on  cnrrtvpond  in  the  M'nNilivnt,  and  ihnt,  therefore, 
(he  mrnitil  ot<naiti(iii  mullinji  IViim  our  Incikiii^  at  any  aii}t*:t  or  view  would 
corm|wnd  csnctly  (o  the  n.-tinal  imsEC.  Wc  hnd,  however,  thai  this  is  not 
the  cnre.  The  Mnentions  and  probably  even  the  simple  setimry  iinpubea 
produced  by  an  image  n;nct  upon  Mcb  other,  and  thefe  reactions  modily  our 
mrcvplions,  independently  of  tb»  pbysicnl  conditions  of  tbe  retinal  imase. 
There  ariae  oeriaiu  diacrcpanciea  between  the  retinal  image  and  ili«  jiercep- 
t*(>n,  some  having  tlieir  siiurce  in  the  retina,  some  in  the  bruin,  uiid  <ith«n 
beiuji  (if  Bucb  a  nature,  that  it  is  difficult  to  say  where  tbe  irrelevancy  is 
introduced. 

Jiraiiialion.  A  white  patch  on  a  dark  ground  appears  larger,  and  a  dark 
patch  00  a  white  ground  Soulier,  than  it  really  is.  Tbio  t*  e»pecially»o 
when  the  object  is  somewhat  out  of  focus,  and  may.  in  this  case,  be  partly 
explainet]  by  tbe  difluuon  circles  nhich,  in  each  case,  encroach  from  the 
white  u]Mm  the  dark.  But  over  and  beyuml  ihi«.  any  Mu:»ati<in,  coming 
from  a  given  retinal  area,  oocufdea  a  larg<^r  nbare  of  tlie  livid  of  vijtioti,  wban 
the  rt:>t  of  tlic  rclina  atid  central  visual  apjiarstus  are  at  reel,  than  wli«d 
they  are  simultancoHsly  excited.  It  is  as  it  tbe  neijfbbonn^,  either  retinal 
or  cuebrvl,  structures  were  sym|>aiheuca]ly  thrown  into  aouon  at  tbe  saow 
titnsL 

Omtrtul.  If  ft  white  strip  be  placed  between  two  black  ilri|M,  ibe  edges 
of  the  while  strip,  nnr  to  ine  black,  will  np[>ear  whiter  than  iu  median  por- 
tion; and  if  a  while  cross  lie  placed  on  a  Mack  iMckgniuod,  the  centre  of 
tbs  cron  will  appear  somctimoi  su  dim,  compared  witb  the  }»rt»  cluee  U*  the 
black,  as  to  seem  shaded.  This  occurs  even  when  tbo  object  is  well  in  foous ; 
tbe  increased  tcDsation  of  light  which  cause*  the  apparent  greater  whttoiea 
of  the  borders  of  the  cross  is  the  result  of  tbe  "  contrast "  wiih  tbe  Uaok 
place<l  imrordiately  clwe  to  iu  Still  more  curious  results  are  seen  with 
colored  objecls.  If  a  small  piece  of  gray  paper  be  placed  on  a  sheet  of 
green  )>Di>cr.  and  both  covered  with  a  ihret  of  thin  ttteue  paper,  the  wny 
paper  will  appear  of  a  tunk  color,  the  complementary  of  the  green.  Thn 
eOeet  of  contrast  is  lar  legs  ttriking,  ur  even  wholly  absent,  when  the  snuill 
piece  of  paper  >«  white  iutMd  of  gray,  iiud  geDCralljr  disappears  Nben  the 


siauT. 


tbin  covering  of  tiwuc  jMpcr  i^  removed.  It  ibo  Taniibc*  if  a  hold,  brnul 
binck  liDci  Ik  <lrHwn  round  the  small  piece  of  {wpcr,  m  m  to  iaulAle  ii  frum 
Ihe  ground  color.  If  s  hook,  or  pcni-il,  be  placed  vertically  on  s  (bNt  u( 
while  paper,  nncl  illuminated  on  ooe  Fidv  Ity  the  mu.  and  the  otlwr  tij  a 
candle,  two  shaHonK  will  be  produced,  one  Trum  the  auo  which  will  bv  Ql» 
niinnieil  by  the  yelluwifh  ligtil  of  the  candle,  imd  tlte  other  frvni  Ihe  caaiU* 
nbich  will  in  turn  IwillDminiUcd  bv  the  nhilelii;hl  of  the  sun.  The  fnmtr 
Datiirully  appear*  yelloir;  the  Inttcr.  however.  ap|>eara  not  while  hut  blue: 
it  anunics,  by  contrast,  a  color  eoin piemen  1  a ry  lo  that  of  the  eBuilli.'-li^ 
nbtch  eurrounds  it.  Iftbo  candle  be  removed,  or  ii»  lif;hl  shut  Kfr  by  a 
ccrceo.  the  blue  lint  diiappeare,  but  retiirDs  when  liie  caudle  i»  a^^ain  allimed 
lo  produce  ile  shadow.  If,  before  the  candle  a  brought  baek,  a  vim»u  W 
directed  through  a  Durrow  blackened  luhe  at  some  part  lallin^  entirely  wiiJuB 
the  Biea  of  nhat  will  be  the  candle'f  shadow.  tiK  arem,  nhich  in  the  ahaoiTC 
of  the  candle  appears  while,  will  mniinue  to  appear  while  when  the  caaUe 
is  made  to  cast  iis  shadow,  and  it  is  not  until  the  directiun  of  tb«  tube  b 
changed  so  as  to  cover  pan  of  the  ground  outside  the  shaduw,  ua  well  at  put 
of  the  shadow,  iliat  the  latter  aaHuines  its  blue  tint. 

FUling  vfi  Hie  blind  *poE.  Though,  as  ae  have  seeu,  that  |iartof  the  nitaa 
which  corresfionda  to  the  entrance  of  the  optic  iierre  io  quite  (iMooaibfal* 
light,  we  are  conscious  of  no  h)ank  in  the  tleld  of  ruion.  When  in  lo"kitt 
at  B  paue  of  print  we  llx  the  visual  axis  so  thai  aume  of  the  prim  luuM  fiifl 
till  ll)«  blind  s|M>l.  no  gap  in  [M.-rceived.  We  ciiuld  not  cx|hh-i  to  ncv  a  black 
patch,  Itecau^e  what  we  call  bluuk  is  the  ubteneeof  the  T^tioaiiun  of  ligU 
ln>ni  sirnetur^-a  which  are  »en»itive  to  light;  we  must  have  visual  urgaMt* 
■i:c  hinc'k.  But  (here are  no  vimihI  nrgauM  in  Uiu  blind  sjwt,  aud  ci'iiM-qucotl; 
we  are  in  no  n-ay  at  all  nltbcieii  by  the  nip  of  li^ht  which  tkll  mi  it.  Tlwn 
Ik  in  our  subj<-c-tivv  field  of  vision  no  gap  cormpundinfr  !»  the  gap  in  I bt 
retinal  image.  We  rclcr  ihc  venial i>in:>  coming  from  two  piiiiiis  nf  ihe  i 
lying  cm  uppostlc  margins  uf  the  blind  spot  lo  two  points  lying  cloae  to 
(jnce  we  hnw  no  indication  of  the  spitcc  which  Hcpirates  thcui.  Om 
the  efleclE  which  are  pn>duccd  when  an  object  in  Ihe  field  of  view  paa 
the  region  of  the  blind  spot  there  boa  been  much  diccuniua.  In  (irdiaarr 
f  bion,  of  course,  the  existence  of  the  blind  sp>t  is  of  little  fnonient  sltiWB 
is  outside  I  he  region  u»ed  for  distinct  vision,  and  besides  ihe  image  uf  ■■ 
ubjecl  does  not  lall  on  the  blind  spola  of  b(rlh  eyes  at  the  same  tinier 

Oeu/iir  ^peef ivi.  Ho  far  from  our  perceptions  exactly  currespuiiding  toi^ 
•rransemenla  of  the  luminous  ra^s  which  fidl  on  the  retina,  «c  may  han 
visaaTMn  1^1  ions  and  |ierceplions  in  the  entire  obsence  of  light.  Any  fiiiaif 
lullon  ol  ihe  retina  ur  of  the  optic  nerve  »utHcientlv  inteuae  will  gini  riw  ID 
M  visual  sinsatiun,  (irndual  prei^ure  on  the  eyeball  otusei  a  •enaaliun ol 
rings  ol  i-oloicd  light,  the  socalk-d  jiboephcuee;  a  tiudden  bluw  ou  the  (yt 
caust^  a  M-n^aiiun  of  tlasbes  of  lij^-hi,  and  the  «eeming  idL-uiity  nf  the  vwisl 
»en.'«tions  m  brought  about  with  vinual  tvnxatiotiB  prcMJuced  hy  light  b  aril 
illuMtnili'd  by  ihe  i>laii'iui-nt  once  gravirly  made  in  a  German  cmrt  uf  law,  by 
a  niluwo  nho  atraertfil  that  on  a  pilchdark  night  he  recognirjil  an  awailaal 
by  help  of  Ihc  flaah  of  light  cauM-d  hy  the  iiaMMlant'v  hand  ciiuiiig  in  viiiitBl 
coniaot  with  his  eye.  Klectrical  MiniulalioD  of  the  eye  or  wpiic  nerve  will 
•Iw  give  rise  to  vitual  seoMitloDs. 

Tlio  acnntioiu  nhicli  muy  ariiw  wilhout  any  ligbl  falling  on  the  Rtias 
need  not  necessarily  he  undctintd ;  on  the  contrary  they  may  Iw  moai  cinHy 
dcBnctl.  C-omplex  and  coherent  visual  imagex  or  peicvptiuna  may  ariie  is 
llw  brain  without  any  corresponding  objective  luminoiu  cause  'l''- —  •»■ 
called  ocular  spectra  or  phantoms,  which  are  the  nuult  of  an  inin  u- 

lation  uf  some  (probably  cerebral)  part  of  the  visual  npparutin,  litv  a  li*- 


stogetbt^ 
Vxacer^^H 

MssesMP 


TIBIAL   flBOEPTIOIfS. 

llnc(nr«t  wliivh  givca  them  nn  nppnrcnt  olijrclivc  mlity  qiiiu-  ns  strikiiiK  as 
ihBt  oroniiiinn'  viRual  pvrcepliniiB.  Thoy  mny  occnsionallv  bcseen  with  th« 
ev<9  tifH-n  (iind  ihenefure  wliilo  ordinary  viiiinl  pfrccpliitiis  arv  being  gcn- 
emied»at  veil  hc  when  (lie  eyes  aio  closed.  Tney  sometimes  becuaie  so 
ft«<)uent  Bnd  ol>lni»iTe  as  lo  be  di«(rr««in|;,  tind  J'onu  an  important  elanSHll 
io  sunie  kinds  of  delirium,  such  as  delirium  tremens. 

A}iiTftiulion  of  apttarenl  tite.  Uy  the  eye  alone  we  can  only  estimate  the 
appaifitl  tiie  of  an  ottjecl,  ire  can  only  tell  what  space  it  lakes  in  the  Held  of 
Tieion,  «e  can  rinly  percvive  the  dimensions  of  the  retiDnl  image,  ami  there- 
fore have  a  tijiitl  only  lu  speak  of  the  angle  which  the  diameter  of  the  object 
•ul>teii<ls.  The  rent  sizu  of  an  object  niuat  be  determined  by  other  means. 
But  our  [)eiv«iilion  of  even  the  appareiil  eixe  of  an  object  is  so  modified  by 
coiKurrttil  ciintnislnnces  that  in  many  cases  it  cannot  be  relied  on.  The 
RpptircDi  >iieof  the  muon  nmat  be  the  aame  to  erery  eye,  and  yet  while  some 
peraouB  will  be  found  ready  to  compare  the  moon  in  mid-lieaven^  with  a  three- 
penny iiie<-i>,  Mtliere  will  liken  i(  to  a  cart-wheel;  that  is  to  say,  the  ooffle 
auklriMcil  by  ihenioooseemaioiheoneto  he  about  eigoal  totbataubteDded  oy 
a  lfaree-t<eiiuy  piece  held  at  the  diainnce  from  the  eye  at  ivhich  it  u  most 
commonly  hmked  at,  ami  i»  the  other  about  equal  tu  thnt  Aubiended  by  a 
curt-whevl  similarly  vivHfil  at  the  dislance  at  which  it  is  luMt  commonly 
Inokt'd  at.  If  a  line  niich  an  Ai',  Fix-  23'l'  ^e  divided  into  twoe4]ual  narta, 
A  B,  />  C.  nixl  A  H  lie  divided  bydiMinctiuarks  iuiowvernl  parts,  aa  U  sDuwn 
in  the  livnro,  while  li  V  he  Icit  eiilire,  the  distance  A  ti  will  always  appear 
{;ivii|pr  ilinn  C'B.  Su  nlno,  if  two  eijunl  squnrea  be  marke<l,  one  with  biiri- 
■uiital  and  iIm  oilier  wiib  vertical  alternate  dark  and  light  banils,  lh«  former 

rto.su. 


I 


wHI  appmr  higher,  and  the  latter  hmader,  than  it  really  is,  Ilcnce  short 
pprvnus  uili-ci  drtm-A  liuriznmally  tiriped  ju  order  to  increase  their  apparent 
WiKlii,  aod  veiy  sioiit  persons  avoid  lon)[itudiual  slripee.    Two  pencctly 

IiHrallel  l>tii-»  or  bands,  each  of  uhivh  is  crowed  by  slanting  pamltel  short 
inn,  will  api^ar  nut  parallel,  but  dirergiiig  or  converging  according  to  ilie 
direction  of  the  vrtm-linea. 

AKKin,  when  n  short  jierson  is  placed  title  by  fide  with  a  lall  {)er»(»),  the 
fortner  aiipeara  sborier  and  the  liilier  taller  than  cacti  rually  h.  The  muuii 
(Ml  the  hiiriuiD  ap|>fara  larger  than  when  at  the  xciiilh,  becaune  in  the  lint 
ptMiiiuD  it  ran  be  ntwt  ea>ily  cuitipiired  wiib  icrmtrial  ohjecis.  The  absence 
uf  CQm|«r1iK>n  may,  boHever.  ctjnirilHiic  to  nn  opposite  effect,  a*  when  a 
pet*oi|i  Innks  larger  in  a  f<>x;  hciugsveti  inili*tinclly,hu  is  judgeil  to  be  furtJier 
oil'  than  he  ivally  i«,  and  >o  ap^it-nni  larger  ihnu  he  natuinllv  would  do  at  the 
(ivtani'e  at  which  1h- ii>  suppiurd  tu  Itc.  Ht>,  onnvcmly,  duumt  niountaiiia, 
when  Kcn  dtitiuclly  in  n  L-lear  alnKupbcrc  appear  small,  because  on  aocouni 
of  their  di>i!ncin««a  they  are  judged  to  be  nearer  than  they  really  arc.  Indeed, 
«<ir  daily  lite  is  full  of  inMancea  in  which  unr  direct  perception  is  inodifitd 
bv  circuniM niters'.  Among  ibo*c  circiinmtnncca  previous  experience  i*  one  of 
lUt  most  |H>irnt,  and  thus  simple  {icrceplions  btoouM  mingled  with  «  hat  arc 
In  rralily  judcmeots,  though  freqiirutly  made  unconsciously.  But  this 
intniKion  ft  lui-.!  eicpericnco  inin  present  perceptions  and  sensation*  la  must 
'  "iotia  in  binocular  vision,  lo  which  we  now  turn. 


930 


STOUT. 


rw.3». 


BiKociri^AS  VmoM. 

CbrrapondiHy  or  Jtimtieal  PotnU. 

Though  we  bav«  two  eyes,  nod  must  therorore  r«ceirp  froRi  every  ohJM 
IwQMU  uf  seniiatioDB,  our  perceplian  of  any  object  is  under  ordinHry  cimiK- 
rtunrex  >  bihk's  one  ;  we  aee  one  object,  not  two.  By  mitting  vilher  eve  imo 
nn  nnueual  jKisitiun,  as  by  BquioliDg,  we  can  render  (tie  perception  aoabl«; 
1TC  eee  two  objects  where  one  only  cxisrs.     From  which  it  is  eri))etii  thit 

tinfjleness  nf  perception  depends  on  tbe  imM 
ol'  the  object  Imlling  on  certain  jmuIa  of  ttm 
(B  reliiis  at  the  same  time,  these  parts  betOf  K 

relaied  to  eaeh  irtber  that  the  Aenxatidna  tnm 
eu'h  are  blended  into  one  perceptioQ :  and  il 
is  also  evident  that  the  inovetneau  of  the  ej^ 
balk  are  adapted  to  brinf;  the  inia^  of  ibe 
object  to  fall  on  these  "  eorrMpui)di»ff "  or 
"  tdeutical  "  parts,  as  they  are  called,  of  each 
1  IVV  I  retina. 

When  we  look  at  an  object  wiili  one  cyv 
the  visual  axis  of  that  eye  ts  direcied  tn  Ui« 
object,  and  when  we  use  two  eyes  tbe  ridul 
axei  of  the  two  eyw  couverjje  at  ih«  ol^M, 
tbe  erebalU  innving  accordiujtiy.    Tli« 


spondiiif;  points  or  tbe  two  retinBH  arv  tU^H 


wvHutKo  iwrm. 

t,  Uu>  lea;  K.  tlie  tWbl  Of*:  K, 
tt»(>|M(«)a>Dn«:<ti,lk,.(^ftN  (wlnu 
in  thi  rtf  he  •TV  eornaimidluit  ii>  iha 
pot  nil  n.  (I.  cin  lUalatt  efc  Tlietwo 
flipua  bcloiF  arc  ptQlacaaa*  ttl  L.  Ui« 
Ivfl,  anil  a,  iliw  r^t  inlnii  li  will 
t«  imii  llwl  0,1111  Uju  muter  udpoft. 
curmpuuila  lu  Oi,  ou  (be  nuMi  aide 
at  B. 


OU  which  the  two  images  of  ihr  nbjwt 
when  ihe  visual  axes  cuuverKe  at  tbe  ubycct 
ThuB  in  Fig.  2Sr>.  if  Ce,  C'c,  be  (bo  two  viMul 
axe*,  c,  e,  being  tbo  ocnirm  of  the  fuvw>«n- 
Iralva  of  the  two  eyes,  then,  tbe  object  ACS 
btttig  seen  single,  the  point  a  on  ibe  oo« 
rciina  will  "  corr4«|Kin<( "  tn  or  be  "  ideotfaal" 
with  the  prant  a,  »n  the  other,  and  tbe  raial 
&  in  theoiK^  toihcpointi,in  theoth«r.  tunct 
a  p')ini  lying  anywhere  on  tli«  right  side  of  dm 
retina  hu:'  il*  cQrrcsi>on<Iing  point  i>n  tbe  n^ 
side  of  the  other  rc-tiiia,  ami  the  f>oiu{s  oo  ibt 
left  of  one  correspond  with  tboso  oo  tb«  l«ft  of  tbe  other.  Thus,  while  tbf 
U|>p!r  half  of  tbe  retina  of  the  left  eye  corresponds  to  the  upi^er  ball'  of  tin 
reima  of  the  right  eye,  and  the  lower  to  the  lower,  tbo  hkwo/  side  of  ihe  llA 
eye  correiipiinili>  wilh  the  malar  side  of  the  right,  and  tbe  m-ttnr  *it  ths 
left  with  flic  natal  vide  of  the  right. 

Tbe  bliMiding  of  the  two  sensations  into  one  only  occurs  when  lbs  tws 
images  of  nil  oliject  fall  on  thrifo  corresponding  points  of  tbe  two  rptiaK 
HeDoo  it  is  obvious  that  in  single  vision  with  two  eyes  the  ordinaiy 
iDoveinenIs  of  the  eyeballs  mtiiit  be  such  as  to  bring  the  Visual  axes  to  aB- 
verge  at  the  ohjuci  so  ttnil  the  two  images  may  fall  on  corresponding  poiala 
When  the  visual  axes  do  not  so  converge,  and  when,  tliereli>n<,  tbe  111114H 
do  not  tall  ou  corns>[KMidiDg  points,  the  two  senaattoui  ar«  not  blended  ioU 
one  porecptton  and  vision  becomes  double. 

MovanenU  1^  the  Ej/ebalU. 

Tbe  eye  is  virtually  a  ball  placed  in  a  socket,  the  bulb  and  tbt  orU 
forming  a  bull-and-aouket  joint.     la  its  socket-joint  the  optic  ball  is  capsUr 


BINOCULAB    TI8I0X. 


031 


P 


PW.SM. 


ciU^, 


\ 


M.i 


of  A  viiriet]r  of  nioT«iii«ate.  but  it  cnntiut  bv  anv  vijliinlftry  eflbii  b«  moved 
i>iil  of  ilB  soctivl.  It  is  slainl  tbut  by  n  vcrj  torrible  (iponiog  of  tbo  ey^' 
l\dt  lite  cycbull  may  bo  rligblly  |milruiJctl ;  but  tins  iriSine  lowniniion  timy 
be  n«Klcct4Ml.  By  (IImiuc,  howirvcr,  th«  position  of  the  eyvuull  in  thv  auckel 
DiNV  tK  niat«rinlly  cbaomd. 

Emcii  eyebnll  is  opable  of  routing  rount)  wi  immobile  crntre  of  rotAlion, 
which  line  been  fuiiiKl  to  i>r<  placed  a  little  (1.77  nimj  Wliind  the  centre  of 
the  ere;  but  the  tnoveiui'iils  of  the  oy«  round  tbo  centre  are  limited  in  a 

C'culinr  way.  The  shonlder- joint  is  uImi  a  Iwll-and'foqkct  joint ;  and  we 
DOW  that  we  can  not  only  move  tlic  arm  u|i  and  down  round  a  borixuntal 
ftxw  paaeiDK  through  the  centre  of  rotation  uf  tbo  bend  of  the  humctiiit,  and 
from  «id«  to  ndo  round  a  vertical  axis,  but  w«  can  abo  rotate  it  round  its 
own  longitudinal  axi«.  When,  however,  we  come  to  examine  clo^ly  the 
tuoTemenU  oftbc  eyeball  we  lind  ibut  tliougb  wo  can  move  it  up  an^l  down 
round  a  horiionlal  axiti,  aa  when  with  tiied  bea<)  we  direct  our  viaion  to 
the  heavens  or  to  the  ui^untl.  and  fmiit  side  to  side,  as  when  we  look  to  lefl 
or  ri);ht,  stul  tbuuub  by  combining  iheee  two  movemeota  we  cau  give  the 
eyeball  a  rariely  iil  inclinalluns,  vtv  cannot,  by  a  voluntary  effort,  rotate  tlie 
eyeball  rouiid  its  lougitudinal  visual  axia.  The  urraiigeuieui  of  tlie  mutclet 
itf  the  eyeball  will  permit  of  such  a 
tuovemeut,  but  we  ciinuut  by  any  direct 
effort  uf  will  bring  it  about  by  itMlil 
la  certain  rauveucnl.-i  of  the  eye,  rota- 
tion uf  the  eyeball  doea  take  place ;  an<l 
by  brineiog  al)i>ut  tl)«<e  movement,  we 
can  imiiroctly  cauw-  mtnlion ;  but  wc 
cannot  rotate  tlw  eynhnll  except  thuti 
iiidirvclly  Uf  a  part  of  these  movement:^ 

If,  wh<-R  vision  in  directed  to  any  ob- 
je<'t,  the  head  be  mnvei)  from  eido  to 
siile,  tile  «yc«  dn  not  mi.ive  with  it ;  ibcv 
app<-nr  to  reimiin  stationary,  very  much 
as  the  needle  of  asbip'scompnsa remains 
Blationary  when  tbe  head  of  the  ship  is 
turned.  Tbc  change  in  the  pOBilionof 
the  viMial  axes  to  which  the  moveuenl 
of  the  head  would  naturally  ^-ive  rise  is 
met  by  compeosatiD)'  moveiuvnis  of  the 
eyeballs;  were  It  not  mi,  itteadineas  of 
TisioD  would  be  iaipuatilhle. 

There  is  one  posiiiuu  of  tbe  eyes  whid) 
ha*  been  called  tbe  firimarg  jiafilioti.  It 
oorrcaponds  to  that  which  may  be  at- 
tained by  looking  at  the  dlntaot  borixoii 
with  the  head  vertical  and  tliv  body  up- 
right ;  but  ltd  exact  deterniiiiution  re- 
i]utrea  sjieciul  prc^-autious.  The  visual 
axes  are  then  jmralkd  to  i,iu:b  other  and 
to  tla-  meiliiui  J'Iiuh:  of  the  iH-ad.  All  other  pcwitiviu  of  tho  eyea  are  called 
teoondatTi  ftotUioiu. 

U*mim  «/  lAc  tgtiaU.  Hie  eyeball  b  mover)  by  six  muscles,  the  rttti 
tM^tnOf,*mtrittr,iuiernu*,mDd  exleruiu,  and  the  oltliftii  infr-rior  and  niperwr. 
It  b  fixilM  by  calculation  from  the  attachments  and  din-dioMH  uf  tli«  mus* 
clei'.  ajid  Ooufirmcd  by  actual  obtervatioii,  that  the  six  muscJeri  may  bo  con* 
sidurcd  u  three  pain,  each  pair  rotating  the  eye  round  u  particuUu-  axis. 


Mi 


IMtnaiH  cor  ra*  ATTucacm  nr  na 

UlHLI*  ur  THE    SYC    tHS  OT  THDM    Am 

or  lUir^iluK :  thg  t*iwr  totBH  npramiMd 
b>-  duitdl  lla«L 

Til*  Kill  llT  nULiIII  .if  III*  MOIU*  PlMIDUt 

and  inHmuii.  b«in(  |cr|wndluulBr  (o  tht 
pUnuff  lhc|wp«.  atnnotMihawn.  (AMcr 

Fiisi 


m 


SIOHT. 


The  rclaiive  nitnchiueuts  aci]  ttie  nxta  of  rolalMi  are  diflgmuimduiDT 
vlwiwii  ill  Fig.  236.  The  reclus  Miperinr  and  ihe  reciiis  inferior  rotate  tlit 
eye  nxini)  ali»ri£nntu1  axid, uliich  isdirected  from  the  upper  end  uf  ihf  dok 
tr>  ilic  icnipIiT;  the  olitiijuti^  Mi|iennr  aod<il>1ii|uue  inferior  rL>u ml  a  liofitooul 
nxixlin'i-U'd  rriiin  the  renire  i<f  tbe  eyvlmll  luihe  occiput :  and  tli«  rectm  lo- 
t«niUK  and  recttiH  cxUTiiiin  rfiiind  n  vt-rlical  axis  (uhich,  being  at  right  aa^kl 
lo  iW  plants  i;fthc  paiifr.  ninnoL  be  »lionu  in  llie  diaKram).  [MHini;  thrati^ 
lb«  reiitrc  ')f  riitiiiinn  nt'llic  evrbiill  |uinillcl  (o  ihe  meilian  plane  of  ttin  hiM 
when  (lie  liciid  i.->  vrrlinil.  Thus  the  Inller  pair  aclin;;  uluoe  woiilil  lurn 
lh«  eye  fn>m  itide  l»  r-ide.  the  other  *trnight  jwir  iivtinf;  alone  would  tanft 
Ihe  oii'o  up  and  down,  whili^  the  tibli'iuo  niiudea  nrliug  alone  wuuM  pn 
Ui«  eye  an  obli'jue  movement.  The  rcctiiv  exteniitfi  acting  alooe  wouM 
turn  (be  eye  lo  ihe  miilnr  side,  the  internuK  to  the  »aMl  »de,  the  mOui 
eupcnor  upward,  the  rectng  interior  downwunl.  the  obliijue  Miperiordnvv- 
ward  and  mitnanl.  and  the  inferior  tipwnrd  and  outward.  Tbe  rrcti  ftiperiit 
ntid  inferior  in  nioviDgtheeycnpnnddowiialtu^iiirn  iiKiiuenhat  tnvratdud 
al  the  some  tjme  give  it  a  *lieht  amonnl  of  rotation ;  Ixit  thin  i.-i  corrcoH 
if  the  obliijiie  niiiteK-«  net  »t  ine  Mime  tinK< ;  and  it  in  found  ibiit  lh«  rectiu 
enperior  ncling  with  the  obliquus  interior  move*  tbe  eye  upward,  and  tkt 
rectus  inlerior  with  the  obliiiuiis  superior  ilownwnrd  in  a  verticnl  directina 
Iti  oblique  movements  also,  the  obliqui  are  ulweyo  ataumietl  with  tW 
reeti.  Hence  tbe  various  muvctDenis  of  the  cyolwll  may  bv  nmnged  ai 
follows : 


E3cTation, 
iMprcaaton, 
Adduction  to 

nasal  side. 
Adductiuii  to 
maUr  side. 
Elevation  with 

adduetion. 

Depreidion 
nitb  adduction. 
KleTAtion  with 

■brluetiun. 

Deprextloii 
wilb  ahdnction. 


Reetui  •u|>erior  and  nbliquu*  Inferior. 
Keelua  interior  and  obliquus  lajreriur. 

ileetu*  iQteniu*. 

Elect  lu  extern  us. 

Kcctiut  superior  and  internns  with  obliiiuu* 

inferior. 
Rectus  la ferhtf  and  internns  wilb  obli<|Uus 

superior, 
Iteelus  RUperiof  and  cxivrous  with  oblii|uui 

inl'eriur. 
BectiiH  inferior  and  exiernus  with  oblI(]Uu« 

superior. 


Oidrrfinotton  of  vimal  movetumlt.  Thus  «t«i  in  the  moT«nienb  uf  i 
aingleeycn  eonsidcmble  amount  of  coordination  takes  place.  When  tits 
eye  is  movml  in  iinr  uilier  than  the  verlu-ul  and  horiznninl  meridiaai,  iw 
pnlse?  must  descend  t<>  at  least  tbrcv  (uusc[<«,  and  in  »u<'h  relative  energy  to 
eaeh  of  the  three  as  to  product)  tbe  rc|iiired  invlinalirm  of  the  visual  aim. 
Uut  the  cDiirdiniition  unevrvfl  in  binocular  vision  is  more  striking  still.  If 
the  movements  of  i>ny  {lereon's  eyes  be  wacehe'l  it  will  be  aeva  llint  the  Iwv 
eyes  move  alike.  If  ihe  right  eye  moves  to  the  ri(;hl,  «>  ili»s  alwi  the  UJl : 
and,  if  tbe  object  loukctl  at  Iw  a  disUint  one,  exactly  to  tlie  aume  extent;  U 
the  right  eye  looks  up,  the  tefk  eye  hxiks  up  also.  aiKl  H  in  e^^-ry  iitbur 
direction,  very  lew  pereuns  nie  able  by  a  direct  eHort  of  the  will  ui  taitn 
one  eye  independently  of  the  otber ;  though  some,  and  iinioiiji;  them  one  ills- 
linguibbed  both  as  a  pbysiftlogisi  and  an  oculist,  have  ncttuireil  Ihu  po«4f. 
lu  fact,  the  moventeiils  of  the  two  e^'ea  are  so  arran^d  that  in  the  variMi 
nioveineutB  the  images  of  any  object  »liould  fall  on  the  i.MrrfKpiii)dirtg  [miaU 
uf  tbe  two  reiiiuu,  mud  that  thus  sin^^le  viniou  should  reitili.  We  isnMit  ht 
anr  direct  efK>rt  of  our  will  nlaee  our  eyex  in  nii'b  a  {Muiiion  that  the  ran  lif 
liglil  pniceetling  from  any  object  hball  he  bniu^lit  lo  a  focua  on  parts  ut  tb 


BirroccLAR  visros. 


I 


L 


two  rMmu  which  <Iu  not  cornupnii(),  and  thii^  i;ive  rise  to  twa  <lmini>t 
visunl  inuges.  \\>  cna  brin^:  the  visual  kxea  of  the  Iwu  eyea  fraoi  ft  conili- 
lion  uT  jHinllelieni  to  ooe  of  great  convereeDoe,  but  we  cttonol,  without 
special  aMtslance,  bnn)[  them  froin  a  ooudition  of  pnrallelisiu  to  one  of 
divergent.  Tlie  iierei»oa|>e  will  enable  us  to  create  a  diverKencft  If  in  a 
il«rcoei»|HO  picture  the  diAiance  Iwlween  ihe  plattirea  be  invroaaed  verjr 
gradaally  so  a*  carefully  lo  luiiiatain  the  impreMioii  of  a  aiDgle  obieot,  the 
risual  ax«a  may  be  bmuithi  to  diverge-  (^imitarly  if  a  distant  object  be 
loultcd  at  n  itb  a  prism  hi-fore  one  eye,  and  the  tmajre  of  ibe  object  be  kept 
mrrfiilly  HinKle,  while  the  pridu  ia  turned  ven'  !)l»wlr  up  or  down,  tbeni  on 
suihlenly  reiuovinj^  the  pri^m  n  duuhl«  iniajie  id  fur  a  luooieDt  aeon ;  ahow- 
inK  thai  llieeye  before  whi<-h  ihe  prium  vnt  placed  bad  moved  in  dUacnord- 
anoe  with  the  <ilhcr.  Tli«  d>iul>le  ima^',  hoirever,  lu  a  fvw  oocond*  af\tii-  lh« 
reitiiival  of  the  pri»tu  beoomat  klnglu,  un  aoouuni  of  llie  eyca  omiiif;  into 
a4.-c»n  lance. 

It  ia  <>nlv  wliri)  luM  of  oourilination  ooRur*,  n*  in  varioiia  diMaaea  and  in 
alcnhulic  or  nihrr  (H)iw>Riojit,  that  the  miivctnail*  of  the  two  cv«t  oeaM  lo 
agrew  wiUi  uu'h  iilhrr.  It  in  cvidtint,  th«n,  tlial  wh«ii  wv  lonk  at  an  itlijtx't 
(o  lli«  right,  WQM)  wf  thereby  ahdtiot  lh«  right  oyc  and  ailduct  ibo  l«ft.  we 
tlirnw  into  actiim  the  rvctus  cxicriiun  of  tlie  rieht  eye  and  the  r«cluii  int«rniu 
of  the  Icit,  and  vimilxrly  whoi  vc  look  to  the  left  wo  titc  tli«  roctna  eslcrnua 
of  the  left  and  the  rectus  iiitcniiis  of  the  right  ore.  On  the  other  baml, 
when  we  look  at  a  near  (i<>ji:i't,  and  therefore  converge  the  visual  axes,  wc 
U*e  the  rrvti  intenii  of  huth  eye* ;  and  wht'ii  wc  look  at  a  diiilant  ohje<;t,  and 
bring  Ihe  »xct  from  (vuivrr^cnce  tiiwanl  pninllelisai,  we  »tv  the  recti  esterni 
of  b-itb  eyoB.  In  the  varimis  muvPiiiGiils  of  thv<  erv  there  is  therefora,  »o  to 
•peak,  the  moit  delicalp  picking  and  choasing  of  t)l«  muscular  instrunienu. 
Buriug  this  in  mind,  it  cannot  be  wondered  at  that  the  variuus  niovementa 
of  the  eye  are  dejiendeiit  fur  their  cnuMttion  uu  visual  senaatiims.  lu  ordur 
to  BiAve  our  eyiv  we  muj^i  either  hMk  at  or  fur  an  otjeot :  when  we  wish  to 
oonTOge  our  tix-^  ne  l'H)k  nt  some  near  object,  real  or  iiiiaKiiinry.  and  the 
cnnvugence  uf  ibi-  axi.-«  i»  iisuatly  accompanied  by  all  the  ivitidiliuns  nf  near 
Tisioo,auvb  n  incrautci]  nccumnwdation  and  wntraciiun  of  the  pupil.  And 
Mk  with  other  loovemrnts.  The  doae  auocialion  of  the  movcroenls  of  the 
eye  may  tie  illtictrnl<H)  by  the  fidlt)win);  au»:  RuppuM  the  eyca,  to  Mart  with, 
i|ir<Ht(^)  fi>r  thi;  far  diDtancr.  and  thai  it  is  deaired  lo  direct  attention  in  a 
nearer  iHiint  lying  in  the  vi*i:nl  linr  of  the  right  eye.  In  ihia  case  no  move- 
toeiit  of  the  right  eye  is  roi|uircd  ;  all  that  is  neoeatary  is  for  the  IcH  tyv  lo 
he  turoeil  U>  the  right,  that  is,  for  the  rectus  internua  of  ihu  left  eye  to  lio 
thrown  into  acii^m.  But  in  onlinary  motrcnicnta  the  contradinn  of  this 
miiacte  in  always  associated  with  eitlier  the  recttis  eitornu*  of  tlic  right  t>ye, 
as  whm  both  eyes  arv  Uimcd  to  the  right,  or  the  roclns  internus  of  tluil  tw, 
aa  in  i-onvvr|;on<x ;  tltc  muscle  is  (piitc  unacciittomed  to  act  nluno.  This 
would  lead  oa  to  suppose  ihnt  in  the  civv  in  luoslion  the  cinlractifin  of  the 
reclua  inlamus  of  tne  lel\  eye  is  uecKOtpunied  by  a  otMitmction  of  both  recti 
exiernus  and  inlernua  of  the  right  eye,  keeping  that  eve  in  lateral  i-(|i)i> 
librium.  And  the  peculiar  oscillating  movements  seen  in  the  right  eye,  as 
well  at  the  seoM  of  efllirta  in  the  right  eye  which  ia  felt  by  the  person,  show 
ibia  to  he  the  case. 

Hueh  a  coinples  CHirdinaiiou  re(|uirea  for  its  carrying  nut  a  distinct 
nervous  wHcliiuFry,and  wc  have  rea^tons  for  thinking  that  such  a  machinery 
esitU  in  certain  purls  of  the  corpora  ipiadrigeniina  or  in  the  underlying 
structurm.  In  the  nate*  there  apttcani  lo  be  a  cumnion  eentie  for  both  evos, 
stiuiulation  of  the  right  side  prwiucing  niovemenis  of  both  eves  to  ibe  ieii, 
•if  the  led  side  luavemeiits  to  (be  right ;  while  sliiuulaljoa  iu  tlie  middle  lino 


SS4 


sianT. 


Iwhiod  cauMa  s  dowmiruni  iiiovement  of  bold  eyea  with  conv«rKen<w  of  ilit 
flxe«.  sill)  in  Ibe  fmnt  nil  unwiird  nvovciKiil  nitb  return  to  parol  Id  irai,  hotk 
acouiiipauied  by  lh«  iintuntlly  awi^ctaletl  inoreitients  tit  the  paf^il.  SiimaW 
tioD  of  variouH  paru  uf  the  mats  muH^ti  rnrioua  ntaveineols.  <lepei>Hin|:  an 
tlie  ]>08ilioD  of  ibe  »prii  ttiraulnted.  AAt-r  nu  inciuon  in  the  middle  ItM, 
BtimulatMHi  of  Ibe  ncrvi^uN  centra  ou  one  ude  producea  iDorenMinl*  io  tW 
ey«  of  the  aame  aide  ou}y. 

Ttif  Horopter, 

When  we  look  nt  nny  object  wo  direct  to  it  the  vmwA  kxv*.  t«  tliat  wtini 
the  object  is  stnnll,  tbt?  "  corr««ni>nding"  pnm  of  the  two  rrriiiiwi.  nn  «hi«l 
\hf  two  itniigos  of  the  ubjcct  fill),  lie  in  their  mpective  fo7(w  ccntrnln.  But 
«bile  we  nrv  looking  iit  the  pnTticiiUr  object,  the  images  of  other  ntjeeit 

surrounding   it   fall  nn   ibe   retina  ma- 
no-  W.  rounding  the  fov««,  and  tbu«  go  Xu  tarn 

e  nhat  i«  cnllcd  indirect  vision.     And  il  ii 

ohviougly  of  advantage  that  thefe  ima/n 
also  fihontd  fall  on  "  cor  res  pond  tag"  |«rti 
in  the  two  eyea.  Now  for  any  given  pea 
tion  of  ihe  eyee  there  exisls  in  the  field  tf 
vision  n  certain  line  or  aurfnce  of  sucka 
kind  that  ibe  inmgex  of  the  |xiint8  in  it 
all  fall  ou  correfip-mding  jwiint*  of  the  re- 
tina. A  liiio  or  siirfuct'  having  ilib  prop- 
erly is  ea1le<l  a  horopter.  The  hofvpitr 
ia,  in  fact,  Ihe  aggregate  »f  all  thoM'  jxitDli 
in  Kpac- nhicb  arc  projevUil  ita  tv  com- 
aponding  |>otntii  of  the  nrtina;  beoM  ill 
deieniiiitntion  in  nny  pnrlicttlnr  ean  it 
ainiply  B  matter  of  geomi-lrical  calculi- 
lion.  In  wMiiQ  incUinces  it  becnn»C8  a  rar; 
oomplrenicd  figure.  The  rnM-  wh<«a  ftai- 
lire*  arc  m™t  «»ily  gmsped  ia  a  cifdt 
drawn  in  llic  jiliincof  the  Itro  vistial  <i« 
tbrough  Ihe  point  uf  the  convergence  *t 
the  nxen  luid  (he  optic  centres  of  ibe  !■• 
eye«.  tt  k  obvinn*  from  geometrical  rchtlions  that  in  Fig.  '237  the  iaifa 
of  any  point  in  the  circle  will  fall  on  correeponding  [H>jni«  ot  the  two  r^ 
liua^  When  n*e  Mnnd  upright  mid  Imik  at  the  dislanl  horixon,  the  horopitr 
is  (appraxininiely,  for  nnrmni  eminetropic  evce)  a  plane  drawn  ihroufb  Mr 
leei,  that  ia  to  say,  ia  the  ground  on  wbieh  we  stand ;  ibe  advantage  of  Oil 
tt  Qbrioii& 

VtSUAL  JviH)MEyT& 

Binocular  vision  is  of  use  to  us,  inasmuch  ns  the  one  eye  is  able  to  till  iif 
ibe  gitp  und  imjierfeclionii  of  tbe  other.  Fur  example,  over  and  abuvo  lb 
monocular  filling  up  of  the  blind  spot,  of  which  we  spfike  on  pan  9S^, 
since  the  two  blind  xpota  of  the  two  eyes,  being  each  on  ibe  nanal  nA§,  irr 
not  "correnpondinu:'  part*,  the  one  eye  suppliM  thiU  part  of  th«  Caitrf 
vision  which  i»  lacking  in  tbe  olbrr.  And  olber  im|MTfecti»n«  ara  atmilarh 
mode  good.  Rut  ihn  great  uw  of  liiixiciilur  viiinu  t»  to  nlTiiF>l  us  iBcaa* 
of  forming  visual  jui^menia  oonciTtiiiig  the  form,  mec,  and  dtstance  «f 
bbjecis. 


nUCllUI  ILIIvruTDM  A  8111  ri.i 

tloMuma- 
Wlran  tli»TUu>l  US  nHnvisaiil  C.  Ihe 
nimgn  0.  a  of  anr  |otnl  A  t'U  Ibc  i^lrvlc 
dnoii  IbriMiiib  C  mid  ihu  a|<Ucal  cvatna 
1. 1  «1I1  flill  on  a>iiT*|niulInK  p'4n». 


vtscAL  3t:D0ue:;Ts. 


»83 


I 

I 


Judgment  of  diManee  ami  tite.  Th«  pempiiont  which  «r«  gain  ■imply 
Mtd  tMt\y  by  our  lield  of  virion  concern  two  dimensions  only.  We  ciin 
berontc  aware  of  the  apparent  site  of  any  part  of  the  tield  cormpoO'ling  tn 
anv  particular  object,  and  of  its  topofiraphicnl  reletiona  to  the  re«t  of  the 
field,  but  DO  more.  Had  we  nolhtn);  more  to  depend  on,  our  Btght  woiild  be 
aJmost  valueleaa  aa  far  as  aiiy  exact  infornmtton  of  lh«  eztenial  world  wai 
ouneemed.  By  aaaociation  of  the  visual  Bensations  with  Mnntions  nf  loiioh, 
and  with  scusiiliouf  derived  fr<>m  the  movementa  of  ihe  eyeballs  rei'ilred  to 
make  any  such  part  uf  the  field  as  corrceponda  to  a  [larlictilar  object  dis- 
tinct, we  are  led  to  form  ju(l;;menls.  t.  r.  (o  draw  conchiatriDs  concernini;  the 
esletoal  w<>rli)  by  meona  of  an  inlerprctalioo  of  our  visual  perce|itionB. 
Lfwkin;;  Itef-ire  u».  we  say  we  see  a  cennin  object  nf  a  certain  cnW  neArty 
in  fn>ul  of  us.  or  much  un  our  ri);ht  hand  or  much  od  our  left  ;  (hat  ia  to 
aay,  nc  juilp.-  such  an  object  tii  he  in  such  a  ptisition  because  fwm  the  con- 
■Ulutiuu  of  our  brnin,  str«U]i:thcue<I  by  ull  our  ex|)erience,  we  associate  such 
a  pan  of  our  field  of  viBion  with  such  an  <)bje<-t.  The  subjective  visual 
coRi|ilcx  a^nMUon  or  )<er«.-cj)lion  is  to  us  a  syinbul  of  (he  external  object. 

K\'ea  with  one  eyo  we  caD,  to  a  certain  extent,  form  a  judf;ment.  n'>t  only 
aa  tu  the  position  of  the  object  iu  a  plane  at  rifcht  angles  to  our  visual  axis, 
hut  almi  an  to  its  dixtuncc  fn>in  us  nlont;  tlte  visual  axis.  If  the  object  is 
near  to  UK,  we  have  to  acc'iuimoilate  for  near  visioa  ;  if  far  from  us,  to  rvlnx 
Mir  acoum mild nti»n  inechnni«m  so  that  the  ere  becoroei  mliuHled  f»r  ilistance. 
The  mtitcular  meivH:  (iif  which  we  shall  »\)t:tM  preaently)  of  this  L-lTort  enables 
»s  lu  form  a  judj^mcnl  whi.>thi:r  the  object  is  far  or  near.  Se<-int;  the  narrow 
twige  uf  our  acoommcxlalioii.  and  the-  ^li|{ht  muscular  etforl  wliicb  it  vntaiU, 
kll  nonocnlar  judi;meul*  of  diiitanoi!  must  b<^  lulijuct  t»  much  crmr.  ?^vvry* 
one  who  has  tried  to  threnil  n  neeilli;  without  unin;^  both  oyc«,  knows  how 
grmt  these  errors  may  be.  When,  on  the  other  hnnd,  wc  use  two  eyea,  we 
have  still  llie  vanalions  in  aci^ommoilntion.  and,  in  addition,  have  all  the 
ai><>i»la[ice  which  arises  from  ihe  muscular  effort  of  so  diroctinf;  the  two  eyes 
on  tlie  object  that  single  vision  «hall  reuilt.  When  the  object  i^  near,  we 
cimverge  our  visual  axes;  when  distant,  we  brinj;  them  hack  tuwar>l  jwral- 
lelisni.  Thin  necessary  contraction  of  the  ocular  muscles  affords  a  muscular 
sense,  by  the  help  of  which  we  form  a  judgment  us  to  ihe  distance  of  the 
object-  Hence,  when  by  any  means  the  convergence  which  lb  aeoeaaary  to 
bnog  the  object  into  single  vision  is  lessened,  the  object  seems  to  beoone 
roore  ilisiant,  when  increased,  to  move  toward  us:  as  may  be  seen  in  the 
■lereoaouite. 

The  jiM^meut  of  siie  ia  closely  connected  with  that  of  distance.  Our  |)«r> 
ce|itioiu,  ([aiiied  exclusively  fK>m  the  Held  of  vision,  f^o  no  further  than  the 
apparent  late  of  the  ima^,  i.a,  of  the  angle  subtended  by  the  uliji-ct.  The 
real  sixe  of  the  object  can  only  be  gathered  from  th«  apitarfut  Mf  uf  the 
Image  when  the  distance  of  the  object  from  the  eye  is  known.  Thus  per- 
crivin^  directly  the  a|>iiun:nt  niw  of  the  lniB}(e,  we  jud^  the  di*lanc>«  of  the 
object  ^'iving  the  image,  and  upon  that  oome  to  t  conclusion  as  lo  its  size. 
Ami,  cxinvcriwlr,  when  we  sec  an  object,  of  whose  real  Hi7.c  wc  nrr  uttuii  aim 
aware,  or  arc  led  to  think  wc  are  aware,  our  judgnx-ut  of  its  ilisl.ioce  it 
inSuCDC^  by  its  apimrcnl  sixc.  Thus  when  in  our  ticid  of  vision  there  ap' 
pears  the  inuigc  of  a  mim,  kniiwint;  otlicrwtse  the  ordinary  siw  of  a  man,  we 
inftr,  if  the  imagv  be  \nrv  small,  tlmt  the  man  is  far  off.  The  reason  of  the 
innge  being  small  may  W  Wcnuoc  the  man  is  far  off,  in  which  case  nor 
judgmcnl  is  correct ;  it  may  bo,  however,  bocJiuan  the  image  has  been  lee> 
sonrd  by  nrti6eial  dioptric  means,  as  when  the  man  is  lookeil  at  through  an 
invcrlcti  telescope,  in  which  case  our  judgment  becomes  a  deluaion.  Ho  nbo 
an  image  on  aecreeo  when  gradually  enlarged  swins  lo  cooie  forward,  nlien 


9S9 


SIOQT. 


eraduallr  (liiniuiitlicd,  Monu  to  recede.  In  Umm  omh  tbe  inflnwio*  oa  *Kr 
jwJgin«D[  of  tbc  iiiuRciilnr  hcmo  at  biuooular  adjiMinoot.  or  Bwnooalir 
accnmnkodstiun,  n  ihwariid  hy  the  man  ilinx'l  iiillucnoe  of  ibe  iwofiiittin 
belirocD  rite  kdcI  (ttXiiDcv. 

Judfftiifnt  oj  ntliiilty.  Wbon  wo  look  at  n  siunll  cjrc'o,  ill  porU  of  tW 
cirole  aro  nt  the  tamv  ilislaooc  from  »*,  all  pjirta  are  e<|[iul)y  di»liticE  al  \i» 
tamo  time,  vbctbor  ne  luok  at  it  will)  ono  ojrcor  with  Ihd  eyes.  VVlico.aa 
the  oilier  hnod,  wu  I<H>k  n(  a.  sfilicro,  tbo  rariuuB  pnrl«  of  wliich  &r«  al  dUEn- 
eiit  <li»lanciit  frum  u*,  n  tvmie  of  the  aocoiniiiodatiun,  but  much  more  a  taut 
of  Lh«  binocular  a<^iiatfDeiit.  of  the  coDvei^eiwe  or  the  oppoaito  of  tbe  t«fl 
ei-o, required  tomalte  Uie  various  parta«uceewivelyd)»tii)ct,  makes  uaawm 
that  thi^  TftriouB  parte  of  the  s|>liere  are  uue<]uall_v  <li»laoi ;  aod  froni  that  «r 
forai  upudgnicnt  of  ita  solidity.  As  with  diatatic-e  of  ohjeoU,  so  wilb  toltd- 
ily,  which  is  nt  bottom  a  matter  of  diaUuioe  of  the  parts  of  an  object.  «« 
CM)  form  a  judgment  with  one  eye  atone;  but  our  ideas  beooioe  niucti  man 
exact  and  trustworthy  when  two  eyes  are  use*].  And  we  are  much 
by  iho  ell«4.'is  produced  by  the  redeotion  of  li^ht  from  the  various  mi 
of  a  solid  object ;  eo  much  so,  tlwt  raised  surfaces  may  be  made  to  a[  __ 
depressed,  or  tiiK  t<n-«>i,  and  tlat  surfaces  either  raised  ur  depressed,  by 
proprijiie  arraD^Dieuts  of  shadings  aud  shadow. 

no.  SM. 


B 


f^^c"^ 


\j 


/5x 


R 


BioM^ular  vUion,  iimreoTer,  aflbrd*  us  a  meant  «f  judxios  of  thir  aiiliditi 
of  obj<.-ct«,  ina-MDuuh  iin  the  image  of  any  wjlid  ubji-ct  which  falls  oil  lo  tbi 
right  eye  cannot  he  csiu'tly  like  Oint  which  iklls  oo  iho  lelV,  tJ>ough  both  in 
coiiibiDcrl  in  (be  sindo  purccption  of  the  two  eyes.  Thus,  when  wc  took  M 
a  tniucated  pyramid  placeil  in  tlie  middle  line  before  u»,  the  iroAM  wkidi 
falls  on  the  right  eye  is  »f  Iho  kind  repremited  in  Fig.  '£Mi,  R,  white  that 
which  falls  on  Iho  lefV  cyo  has  the  form  of  Fig.  2^^,  h;  yet  the  peraeptita 
{^ined  fn>m  the  two  inin^s  tngclhor  C(inwpciDdi<  to  the  form  of  wbidi  Fifr 
',!38.  It.  is  the  projcclinn.  Whenever  wc  thus  oomhiiM*  in  one  perceptiou  tsa 
disfiimitar  iniiigirx.  one  nf  the  one,  and  tho  otlier  of  tlie  otlier  eye,  we  jadp 
that  tlie  object  t:iviiig  riMt  to  the  images  i*  solid. 

This  is  the  simple  principli-  nf  the  sicreoscope.  in  which  two  sligbtJy  dls 
simihir  pictures,  such  as  would  correspond  to  the  vision  of  each  eye  stp- 
«»taly,  »tv,  by  meisns  of  rvAecling  mirn>rs,  as  in  \Vhe«t»U>[ie*s  urMinal 
tiwtrmDent,  or  by  prisms,  as  in  the  ftrni  introduced  by  Brewster,  made  M 
coat  images  on. corresponding  pnrLi  of  the  two  retinas,  so  ss  t>i  produDS  ■ 
Stable  perception.  Though  each  picture  is  a  surface  of  two  diinea^iiiiiis  uslr, 
tbe  resulting  perception  is  ibe  eaciie  ns  if  a  single  object,  or  group  of  objccu. 
of  three  dimeusions  had  been  looked  at. 

It  might  be  6Up|>osed  that  the  judgmeut  of  solidity  which  arises  vrboa  iv* 
diasimilttr  images  are  thus  combined  iu  one  perception,  was  due  to  tbs  fact 
thai  all  purls  of  tbe  two  ima^  cannot  fall  on  correspond ioR  parts  of  iW 
two  mtiiuis  at  the  same  time,  and  that  therefore  the  combination  uf  iIm  in 
needi)  mmie  niovenieut  of  ilie  eyes.  Thus,  if  we  superimpose  K  on  L  {Fit 
2S8j,  it  it  flviilent  that  wheu  the  bases  ouiuvide  tlie  imucated  ajiioea  viill  uod 


MM  rena;  ht^iioc,  whrn  tba  biwa*  fiill  rni  oormpoDdiii}:  [wirts,  ihv  ti|M«a 
will  Dot  be  C'lmbiiiMl  in  <>av  imsf^,  kn<l  i''<v  ivrrM ;  id  order  thiU  boUi  inH)* 
b«  cotnliiiK'f},  tlicrv  niuit  bp  n  slight,  rapid  Bi'ivrmciit  of  the  cvm  from  ibo 
OM  lo  the  uthiT.  That,  hnncvrr,  ni)  Kiich  movumMit  ia  aetxmstry  for  -itdi 
portieuiarwe  is  •Itowii  by  the  fad  that  ^1  id  obj<-(?C«  itppMrna  iuch  irbai 
illuminatnl  bj  >n  eledric  ipprk,  tho  diirulinii  of  which  h  ton  short  to  iwrmil 
of  any  n)ovenenl4  of  the  <>rM.  If  rhe  fln«h  occurred  at  the  mnmcnt  (hat 
lb»  •yen  «r«re  hinocuiarly  Biljustcd  for  the  bases  of  thp  |>yrnmid».  tho  two 
apion  ni)t  fnllinj;  on  exadlr  comspn^Hlin;;  piirts  noulil  f>ive  rise  to  two 
pom^pliona.  and  thp  whole  object  ouuht  to  aTtpear  caiifuseil.  That  it  do«e 
ant,  but,  on  the  cnntrary.  appears  a  single  mlU).  must  be  the  result  of  cere- 
bral operations,  res'dliiis  in  what  we  have  called  a  ji>d)>meai. 

Stmg'jU  of  th(  two  fiti'U  of  vitioH.  If  the  iioajte^  of  two  surfaces,  one 
btMik  and  the  other  white,  are  made  lo  fall  on  eorrespoudins  paitsxf  the 
•y«,m  as  to  be  united  iulo  a  Bincle  perceirtion,  the  result  it  not  always  a 
mixtnre  of  the  two  inipreMinnB.  that  ix.  a  unir,  but,  io  many  cases,  a  seosa- 
tion  similar  to  that  pr^xliiced  when  a  piilished  Hurface,  auch  m  |fluiu)>as^,  is 
)ook«l  at:  the  surface  uppean  brillianl.  The  reasun,  probablr,  is  Iwcau'e 
when  ire  l<><>k  at  a  p<>lishe<l  surlaci?.  the  aiiiniint  of  reflected  li;;ht  which  falls 
upon  the  relitm  n  Keuerally  iliirefKnt  iu  Uie  two  eyes ;  aiiil  hence  we  anociilte 
an  une(|ual  stimiilalion  of  the  two  retina:)  with  the  idea  of  a  jmlished  sur- 
face. Si),  aU).  when  the  iiiipruAiiiin.t  of  twi>  c»lorfl  are  united  in  binricular 
%-isioD,  the  rMult  it,  in  most  casea,  not  a  mixture  of  the  two  eolont,  as  when 
th*  nmc  tno  impressions  are  brought  to  bear  toi^etber  nl  the  name  time  on 
a  single  retiita.  but  a  ilruKKl*^  between  the  two  culon,  now  one,  and  now  the 
other,  becomiii)t  prominent,  iiili-rmediate  tintu,  howerer,  bein^  frei|uently 
pasaed  ihrouirh.  Thiit  niayariM-  fn^m  the  difficulty  of  uccommoilatinK  at  thv 
Mtme  time  fur  the  two  ililTcrent  »:>lunt  fsoe  {t.  907 1 :  if  two  cyn,  one  uf  wliinh 
ii  looking  at  red,  and  the  other  at  blue.  I>c  both  «c«omniod>lcd  f<>r  rvd  rays, 
tbt  red  KiiMition  will  overpower  the  blue,  and  Ww  i-crra.  It  may  be  how- 
pTcr,  that  \hv  tonilciicy  to  rhythmic  action,  so  munifcsl  in  olhvr  nimpler 
mauifnttalinns  of  protoplasmic  aclivitv,  niakoa  its  »{)|>caraacc  als^  in  thu 
higher  cvrebral  l&bora  of  binocular  vision. 


The  Pbotectew  Mix-SAStsua  of  toe  Ete. 

Tlie  eyelmll  ia  protecteid  by  the  eyelids,  which  are  capable  of  moTement* 
called  rrsjiectively  opening  and  shuttin;;  the  eye.  The  eye  is  shut  by  the 
contraction  of  the  orbicularis  muscle,  carrinl  out  either  as  a  reflex  or  volun- 
tary act,  by  raeans  of  the  faciid  nerve.  The  eye  is  opened  chiefly  by  tbe 
raising  of  tbe  upjwr  eyelid,  tliroufib  the  contracliun  of  the  levator  puljiebne 
carried  out  by  meana  of  llie  thir«l  nerve.  The  up|>er  eyelid  ia  also  raised 
and  tbe  lower  depressed,  (he  eye  heiu^  thus  o|M>uc-d,  by  means  of  plain  mus- 
cular flbreii  •.•sisiinif  in  the  two  eyelids  and  ic>iverned  by  the  cervical  sympa- 
thetic- Tlie  shuttinn  of  the  eye  as  in  winking  >*  in  general  eflected  more 
rapidly  than  the  ii|)pntUK. 

The  eye  i>  ki-|it  continually  mnkit  partly  by  the  necrotion  of  the  gland*  in 
the  conjunctiva,  and  of  the  Meibomian  t;laod.i,  but  chiefly  by  tbe  scorvtioii 
of  llw  lachrymal  gland,  fndcr  unlinary  cirfuru-itanct*  tlx*  fluid  thun  lunued 
is  carrietl  away  by  thi-  Inohrviuul  cniDiU  inln  ibr  noMil  ><ac  and  thus  into  tlie 
(■avily  of  the  n>iH!.  Whi'u  tht-  M>i.'n.'lii<n  liecDnHs  to<>  ahunilant  to  eacape  in 
this  way  it  i<vt.-rlli>ws  mi  In  thi'  i*lm'k:>  in  the  form  of  ii-am. 

If  a  i(uun(ily  uf  ii^ir-  1 1  i    i'  d,  thcv  arc  found  lo  liirni  a  clear,  faintly 

alkaline  fluid,  in  mnit)  tl^i-.^j;.?  itko  tuliva.  conlaiDing  alwtit  1  pvr  eyau  of 


eiOHT. 


aniids,  oC  wliiirh  a  small  {lart  m  proteiil  In  nmturc.    Among  Ute  mIu  pnccat 
eodium  chloride  is  coDSpicuou^. 

Tlie  nervDua  nicchanisni  ol'  the  wcretion  of  tWB,  in  many  respeoU.  mnn* 
Mea  llint  uC  the  aecKlion  of  BalivA.  A  flow  is  usually  bronchi  about  <*thft 
in  a  rvHex  iiiaDner  by  sliiiiuli  applied  to  the  conjunctiva,  ibe  iiitasi  mncOM 
metntnune,  toti^-ue,  tiptic  nerve,  etc.,  or  mora  direallv  bv  eiii<>li->nB.  VewMW 
OODgeuion  of  itie  heait  ia  alao  said  to  came  u  flow.  Tlie  •^Iferenl  uervc*  beloac 
ftilher  to  the  oerebr&^ioal  aysteo)  (the  laohrymal  and  orbital  brsneW  m 
the  fifth  nerve)  or  arise  ftuni  the  cervical  ftympatlielic,  the  aflureni  aenrn 
varviuj;  aofi^rdirii;  to  the  enciliiii;  caii§e, 

The  avt  of  blinking  undi^ubteilly  fuvtirs  the  pttuotfe  of  team  thmiiith  tb« 
laohrymal  cunaU  into  the  nnsiil  hac.  and  hence  when  the  orhirulari*  ii 
jMUalyiwd  tvani  do  not  pa^  ao  r«a(ti<y  ad  uaual  into  the  oo«e ;  but  iliv  veacI 
inecbaniHui  by  whbb  this  is  ettboted  has  been  inucJi  duputod.  Acmnliaf 
ta  tome  auihont,  the  conlraction  of  the  urbicularis  pre«e«  th<i  fluid  onward 
out  of  the  canals  which  u|H>n  the  relaxation  of  the  orbiouliirin,  iltlataaaj 
r«!ceiv«  a  fmh  i)UBnl!ty.  Othera  maintain  that  a  apecial  arranifrini^nt  i>f  miw- 
cular  fibrUH  keupi  the  eauaU  open  even  durinii  the  chuingnf  the  ItiI^.iui  lliil 
the  premiin;  of  the  omtractl'm  of  the  orbluularia  U  aUe  to  haw  lull  eAea  ia 
drlviDg  the  teur*  thniugh  (he  oauaU. 


CHAPTER    IV. 

IIEARINO,  SUELL,  AND  TASTE. 
Uearino. 

[Phytio(ag'u)al  Anatomtj  o/lhe  Kar. 

TiiReur.orofg&Dof  liekriug,  iflc>iiipooeilorthree  j)arU,cnlIeii  tho  nrftfnur/, 
Mtiidle,  at  internal  ear. 

TtM  aUmiU  ear  ooiwbt*  of  an  oulfir  |>n)jec(iii{(  porliim,  culled  thv  pinnn, 
mntl  tlw  HudltorT'  cmiul,  or  nttatii*  auditoriu*  ejierntu.  (Fig.  2.t5l.)  Tlic 
|>iiitiH  !■  a  »oii)cnh«t  ubiong  fHun«l-«biiiiMi  orgau,  tbe  ttDinllcr  portioo  of  lh« 


Flo.  at. 


f.V4 


;i->^-V 


fAiii 


:«,•■ 


Vumcjti  aWTiOH  or  n*  llR«Tt«  AVBROmn  jNb  Trurii'iTa.    (9urpi.| 

o,  cofSlavliKiai  p«rt  of  tbe  mtuim :  i.  owtow  ti*n>DO ;  <*.  maulmBa  iini«nl  i  d,  nrtv  of  the 

■rmpAunio ;  t,  Ewleelilaa  tub*. 

funii«l  beini;  attaohed  to  tbe  alciill  by  li):aiiii>iit»iiH  tivue,  l)ie  larger  portion 
Bervin^  lo  wlleot  Utd  CODVey  lb«  wimmius  iimlulmtiunfi  to  tbe  niVHlus.  It  is 
composed  of  cartilsfie  covered  by  iuieftuaittit.  It*  iturface  is  irre^larly 
ctirvnt  aod  d«|>reaaed.  The  outvr  nr(>)«<:tiii^  ritii  i»  lh«  hetix :  anterior  to 
the  helit  ia  a  tecood  elevaiiuii.  railed  ib«  antihtUx,  wbirh  dmcribea  a  curve 
pnnialljr  around  a  <Iee)>  tleiircMioD  wliicb  IcwU  to  ilie  tnealus,  called  Ibe 
coneAii.  Between  the  Iielii  luid  aiilthelix  m  thf/ounorike  helix.  Tlie  anti- 
helix  biAircateaat  iissui>eri«r  portion,  and  eitdoK*  tbe/iMm  ofthe  aulibelix. 
ProjectiiiK  [xutienurly  fnun  the  sntrrior  portion  of  the  ciuicha  it  n  papillary 
pmmincix^  called  thi^  tragn*:  ^luiterior  to  ibin,  scparut<Hl  by  n  fiaitirv,  ia  ibo 
anlilmffut,  which  i»  a  lymtiiiuiiiioii  of  the  helix.    Op  the  inferior  portion  of 


010 


HEARIKG,   3HELI.,    A:fD  TJlSTS. 


tbe  piniw  in  m  «ofl  prmliiluu*  iinrtioii,  tenoed  the  lobute.  Th«  niMlai 
leada  trom  Iho  coacba  to  the  mtilillc  utr,  from  which  it  is  aepxrai^  Hr  •>' 
Ijmfno'ic  membrane.  lUi  direction  iit  forwnrJ.  iowtrd,  and  slighdv  u|i'  . 
]u  Inircr  turfiiM  being  loogor  thnn  the  upper,  oa  socount  of  tM  oblii|uiu  "i 
thi;  puMitiun  [>r  thfl  tympsDic  mcmlirune.  The  canal  considta  of  »a  ezUnul 
mevthmiM  earlUnginmi*  porliou,  whicli  in  contiuuoua  wilb  llic  piuna,  >n>l  *o 
liilvnial  OMCWM  pnrtion  funned  by  the  ma-iluid  bone-  In  ibe  etwmni  p-ir- 
tiiiii  of  the  cnnnl  arc  found  nuiiivn>ii»  bain  nod  aebuceoua  (ctaarb:  in  ibt 
iiitcrnnl  portiiin  iire  found  the  ftratuHotu  glantU,  vbioh  Becrete  ft  jwcului 
KiilMtniico  commanly  knono  ns  lfa«  carwax. 


no.  240. 


*f-1 


i^l 


7Ut.   311— IKNXII  ViKV   or  Till    UCKDMllll 

Ti-MTAXi  a  ran  P-mx  vmi  nil  MtLLEn 
ATTjiCHtn.  n.  iiinnliniiivurilruin  ■<(  ihalfnt- 
|«Duni;  A.  nullciia:  e,  t«uil  orelmuUi  llhrci 
■(tb«olrcuiD(^nTnci!:il,liif«r1or.<uidr.fU|«riur 
l]nii|asi«  m.ntrj :  /,  trmcanlo  boo*. 


Fw,  MU-PUX  nr  THt  OMCiai  nc  remnem  m  TKiTvMi'ixt:ii.«int  tntik  MoiFtM. 
of  lAa  ijiiipuiain:  A,  iiMiabmii&  trwioni.  '■  EutUiliUn  l«bc:  <  BMllrta;  r.  limii/iiipM;] 
Ujouw  tjmiiiaiiliDiuol*;  A.  teiinnrtyuiiAiil:  1.  •upedhu. 

The  niidiiU  Mr  or  tymfritiian  \a  an  irre^lur  tlnit«ned  cavity,  aiitiotnl  ta 
the  petrous  portion  of  the  teuporal  bone,  and  lined  irith  a  mucous  iseRi- 
bran«.  It  b  «ej>arate<I  from  ibe  meatiu  by  a  ineiuhratiuui  diaphrB|[m,  which 
H  the  ti/mfinnic  menUifane ;  uud  from  tbu  iiil«(tiat  ear  by  an  oaseo-membranoB* 
partition,  nbich  turnis  a  eommim  wall  fur  Wh.  Tbroufcb  tJK  Kugtachiai 
lube  it  oominunicales  with  tbe  pharynx.  On  iu  poaterior  iraii  ars  Man 
orifices  of  the  inaaluid  ceUn.  The  tympanic  membrane  is  a  setnitnuuiKimU. 
oval  nicmbranr,  cimcave  uu  it*  exlrnial,  nnd  cmvex  on  ita  internal  surface, 
where  it  hiLi  ntliiohed  tbe  long  iiroccw  of  (he  iiiulluuit,  one  uf  the  oosielw.  It 
is  plaotKl  tti  an  ubliipii;  prwilion,  stuping  dowunard,  forward,  and  inwanl  iH 
•n  angle  »f  nl>(>ut  4o  degrot*.  Its  circiimforoooe  U  altadicd  (n  a  gruiitre  in 
Ibe  temporal  bono.  In  the  fietii*  tlii«  iiortinti  of  thr  bone  exiHia  aa  a  oepant* 
piece,  callud  ibef^mp'intc  6on«  (Fig.  240>.  but  it  alWivar<l  becomes  omfisd 
^<  tbe  temporal.  The  tympanic  mcmhrano  oonibta  of  three  layers — lh( 
cxlcnuil,  middle,  and  internal.  The  external  »  a  continiialJoa  uf  ibe  in- 
tvgiimvnt  covering  the  mentns :  th*;  internjil  is  a  cimlinuuliun  of  the  miwou* 
membrane  lining  the  lympaniiTu  ;  the  miildl*  layer,  which  is  the  bust 
importani,  is  tense,  slrong.  and  tibrous,  made  up  of  circular  and  nuliatiag 
fibnM,  nith  a  small  amount  of  clastic  tissue  intcmtixeil. 

In  the  int«riiat  wall  of  the  tympanum  are  tnrismiill  o|>oiiinga— Uie /r A'rfni 
»ni/M  Mad  Jenetira  rottuw/u  — which  communicate  wilh  the  labyrintb.    Tb~ 


pnrsioLomcAL  akatouy  or  the  ear. 


9-11 


f«nr*lnif«tiindii8clo«d  by  a  mcfobniue^  ExUndinj;  belwc«n  ih"  (vnipnnic 
fti«-mbrann  boiI  the  feneMra  ovitlis  nr«  the  omMm.  ammtwii,  at  ihrc«  small 
bona,  which  Conn  b  eyeteni  of  levcre,  nicse  reticles  are  lerntCfl,  t'njm  Ihrir 
rtMnbUiioe  lo  particular  objects,  ihv  malltut,  iueiu,  aod  tUipe§.  (Fie,  :;41.J 
Tbn  lualli-iia  cnneieu  of  a  head,  iipck.  lotip  and  abort  ]>rocCM,  and  Mudle. 
Tln^  hi-a-l  aniculateB  wlUi  tho  nmf  of  the  ijinpanum,  aw)  in  a  di-premion  of 
iha  iiH-ua ;  ll>e  linndle  i*  direcltd  downward  and  altachcil  by  iti>  whole  Icii^-lh 
to  the  trmpaiiio  niembranc ;  tb«  long  procas  ( pnce»nu  rjTnnli»\  »  dir^i'led 
furwam  and  has  atlai-h^I  the  insertion  of  the  lazator  tympani  mutrlt :  tlie 
»h»rt  proceas,  which  is  at  llie  bwe  of  tbe  lonjt  !>««»»»,  has  BtUK-hwi  the  In- 
■wrtioD  of  ibe  Unwrtumfi'ini  muivlf.  The  immi*  coDeiata  of  a  body,  a  long 
and  ibort  procesa.  Thu  budy  of  the  incus  has  a  depmeton  in  which  anicu- 
laivB  the  bead  of  the  mallcut;  the  thorl  )>rocew  is  ariachvd  to  the  |ioeieriur 


t'l'^  'Jt2. 


Fiiksn. 


Kainr*!  ■)». 


('.  *wUtiHlo^  or,  kiiuilucl  lit  tha  wMlbulei  o.  lam  btnivllii'tir* :  r,  ftm«  ntinlttibtrlra ;  A 
i^tfcUdilHMiM]*- t.niiwrtut:  p.  pMcMor:  l,harjwn(sl:  a.n.a.  ■b*iiD|ifiItari>iuciuit]r(rfncb; 
C  mtlitM  -.  «*,  aqtudiun  of  iho  rooblw :  •>.  (in*oiu  tone  or  the  lamipa  >|dnlu.  41iot»  nhlch  It  Uit 
•rBltTatlMUmnnrnmlcBiingaiibtbuTntlbuIvi  A  Ksla  ifmisnl  bclcnr  iha*i4Ml  lamlii*. 

wall  of  tbv  lympaiium;  tbe  long  proctTa(knl[cular  procoa)  n  placnl  almost 
vertically,  and  at  its  rnd  if  a  rounded  proceaa  (the  ot  orhimhrr),  which 
aniciilalei  with  llic  head  of  ihc  Mi[nt.  Ilie  fiapn  i-oDtislii  of  a  bend,  neck, 
two  crura,  and  a  lin/e.  The  head  nrlicuIait'H  with  ihe  long  pron-tn  of  ihe 
incus :  lht>  neek  «cn-fs  lis  a  tioini  of  iDN-rtioD  of  the  »iarH-iiin»  muiclc;  llio 
cnira  divcri'e  from  the  aixK  end  iinilt'  wilh  tW  ovnl  bHM>  at  il»  trreatcct 
diameter.  The  bun-  ia  6xtii  ia  Ihe  feneatra  ovaliit  by  attiu'hmenis  formed 
by  the  lining  nitnibiiiPta  of  Wb  Ibe  tytnjuinii in  and  iulcnial  ewr.  Tliew 
vasiolea  arc  eonneclcil  with  eat  h  other  and  lo  the  wnlla  of  the  tymi  nnum  bv 
ligaiDMils,  and  at  iheir  artionlattons  they  are  rurnixhi-d  with  eartiliiges  nvA 
synovial  meinbrnDes.  They  are  cnTelo)>4il  by  pri>)<'ngatii>ii«  of  ibe  nincous 
Btembrane  lining  tbe  tynipnnum. 

Tbe  iutmiol  tar  or  folryrinlh  ia  ibe  mc«t  enenlial  portion  of  the  aadilory 
api>araiu».  Il  cunsiaia  of  three  ptirtiona — the  irHihtitt,  (■rniiciVcufcir  rano/f, 
and  eofhlea — aud  U  situated  within  the  peln>us  portion  of  the  teninornl  boue. 
Within  ihe  omcouh  labyriuib  ia  a  nienibranona  Inbyrinih  to  wbicn  the  audi- 
tory ncTTc  is  distributed.    The  vestibule  is  un  irregular  chamber  which 


M 


nSARITTO,   SHELL,    ANT>  TASTB. 

ecrvM  H  a  odidihoo  mnuis  of  oaiumunication  betvit«ti  ihe  ivinpuiuiB  uJ 
tKc  twniicirciilu-  caiuU  nod  oodiliM.  Oii  iti*  cxuruul  wall  u  tbe  fencttn 
ovuli».  cIowm)  by  the  bMe  of  the  atJk|>««.  On  iu  intvrDBl  wall  ia  a  dqn«MH 
ciilird  the  fitvf'i  iKmiff^ierica,  which  'm  MfornlvKl  by  i»inut49  upentan  for  the 
Mupagc  of  uuditur^  iivrve-filitmeiiiM.  Abov«  nud  piMerlor  to  tliN  mpntmrn 
u  MiotJivr,  tlic/o'vn  krm'itltipiiea.  Poslorior  t<>  th«  fovoa  benii»phericB  b  the 
oriGco  of  tlM>  nqiitsluctu*  vusUbuIi.  In  the  {Koiterior  wall  are  fire  opcnioa 
loading  to  the  tcinicirculnr  octnalR.  Anteriorly,  it  wmniuuicateB  with  IM 
cochlea  by  tho  npvriurfe  tenia  veAlihitli  taeJiinr^  TUt  tenieireular  entmU  an 
three  io  immbor — l\iK*iiprr'wr,po*U-Tiaror  inferior. mjtAhorixQiUaL  Thn  fam 
tbo  grtnier  purtion  of  a  circle,  nnd  cotnmiinicHtc  with  tbe  TMlibula  oj  In 

PM.1M. 


<ti 


f 


AKPitDccTiTioii  D>  thk  SmictRiTtt It  CiKiu  i.MjRiicu.     iFiuiu  k  mndri  la  Vhtfanlir  fijllni 

Uiiwum.l 
«,  (Dpoilor  Tonlnl .  t^  poaierlor  or  Inbuiat  tvrual :  ma  t.  buriaiiiiu  oanal  j  4,  mmbmb  ai*» 
lD|uf  iliu  two  tvnliAl  r*i'*U:  K  \*n  ul  iliu  vciUtiuUr  favlty;/,  opMins  of  Um  uiandBct  at  Oa 
vcitlbuli. 

openingi,  on«  of  which  is  common  to  tlie  eiiperior  and  horiioiital  caoak 
Ihe  superior  caiitil  ia  situated  vcrticallir  and  at  right  onglee  with  tlie  pos- 
terior surface  of  th«  petrous  bone;  the  posterior  eanal  is  also  vertical  aid 
parallel  with  the  posterior  surface  of  the  petrous  bone ;  (he  inferior  canal  il 
placed  hurizontnlfy  aud  at  right  angles  to  the  others.  At  the  oonnDOiee- 
ment  of  each  of  inese  eanabi  is  a  dilated  portioD,  called  tiie  ampulla. 

The  ooehiea  occupies  the  anterior  portion  of  the  labyrinth.  lu  boae,  whicb 
wrreaponds  to  the  iriternal  auditory  mftxiua,  \s  perforated  by  laauy  mimite 
orifices  for  the  |)anagc  of  tilaments  of  the  cochlear  branch  of  ibc  auditory 
nerve.  The  cochlea  consists  of  a  central  axis,  or  moJInltu,  which  liai  a 
SpinJ  canal  wound  around  it.  Tbie  canal  makes  two  and  a  half  compleu 
luriH,  and  lerminateB  in  the  a^>ei  of  the  cochlea  iu  an  expansion  Leraied  the 
iu/itndlliu/um.  (Fig.  'H').)  i'he  modioluH  is  »>inewliat  cone^baped,  tai 
furiuB  the  internal  wall  of  tbe  canal,  being  [lerforaled  in  iU  centre  and  M>l«t 
by  aitertura  for  the  ponage  of  the  filaiaeuta  of  the  auditory  uerve.  Tbe 
canal  ia  divided  into  tKO  paasBgee  or  eeata  by  a  »e|rtuiu  called  the  lamimt 
tpinlii,  which  is  partly  oweuus  and  partly  tueiubraiiuus.  Tbe  ouaecm  por 
Uon  projecta  fruui  tbe  ciiodiulua,  uiidnay  across  the  canal ;  il  coneista  of  M 
laiuiuie,  between  which  ilie  nerve  filaineuUt  run.  The  meuihranoua  portiM 
exienib  fruui  the  external  margin  of  the  ua*e<ju»  laiutua  t  >  tbe  external  wall 


rilTSlOLOGlCAL  ANATOMY   OF  TQB   KAB. 


913 


A. 


V-, 


e.e. 


at  tW  raoa).  Tt  contiuitH  of  liro  lay^n;  ibe  superior  i»  (he  ii)i-iiilintii«  of 
Corli.  or  mirnifcrnu'i  trrinria ;  ihn  iiifurior  the  tnan&ran'i  baeU'iri*,  wliicli  k 
•ttacbcd  i^xlrnintlj  to  thr  pl'inum  trmilimnrr,  Tli<;M  mctnbmiKii  lire  iilacvH 
psrmltel  «ilh  cncli  i>th«r  un<l  cunlniii  U-tw<ri:ii  tliciu  the  or^nn  0/  Corii,  wliicli 
KstB  on  Uie  bAsilnr;^'  rovmbniiut.     (Tie-  ^Iti.) 

Th*«raAi  mrfifrif/i'coDimiiniciitra  Mow  wiili  thcvwtibule  by  tho  apertura 
$eafa  vrsti^uU  rorhlta;  the  lower  prnwi^,  iir  #r>i/a  lymptini,  cominuntcfttoi 
with  lh«  tyinjniniim  bv  tht>  fctiostni  nitiimln.  Thtc«  ecuin  communicate  al 
th«  a{>ex  of  the  otchmi  by  an  o|K-iiiii(;  liTiDnl  the  hialtu  or  hr/ifotrema, 
which  exists  iti  coDKijunnco  of  11  tlctimncy  or  the  Ital  half  turn  of  the 
■   lamina  Bpirnlis. 

r  SuTlod  III>r>l-Gll  IMI  C^XrllLU.     (IlMnniEr.) 

«,  axil  wtUi  lU  canali:  i,  liiriiiullliuluiii  nt  •nlni^l  uppw  sad  of  Iho  ub:  c,  H|-t"'a  ot  tl» 
eothlM  1  iL  aiMnlmna  ttf  Ouni :  t,  mambmns  of  Bcibdh  ;  /,  tilMHi  or  ballaomiui  1  •>,  antla 

The  ooKous  portion  of  the  lamina  spiralis  baa  on  its  superior  exiomat 

Firlion  a  dcniioiilaled  cartila^initus  eubstanci*  called  the  (antiit'i  lifniiruOttii. 
rom  the  superior  surface  of  the  spinil  luiuiua,  and  internal  10  the  lamina 
denliculaia.  la  a  delicate  tuembrvDe  esi»i<)iu}:  upward  and  outirard  at  an 
Ugle  ul*  about  45  dfyrees  to  tho  cxli-nml  wall  of  ihe  seal*.  Thia  w  called 
the  membrane  of  Reiamer.  It  divides  the  acala  into  Iwo  paeoag^,  the  lower 
of  wliicb  ia  tbe  (fiurFiu  ewhUar'u.  ThiA  duel  eodd  in  the  apex  of  tho  cocble* 
in  actvca,  and  coaimunicat««  at  the  haae  with  the  aaccule  by  the  ditettu 
revnitnt;  h  contains  the  easenlial  |)urtiun  of  the  auditory  apparatus  of  llie 
coeblea,  anil  is  a  part  of  tbe  menibranouit  labyrinth. 

The  oeyin  0/  t'orti  reata  ujwd  the  traiiilury  inembrane.  It  contnsta  of  Lhc 
inner  and  outer  hair-cell.i,  and  two  rows  of  elongaied  cells,  placed  paralld 
with  each  cfther.  bavin);  an  incliuin);;  piitiliun  tti  that  their  free  extrentitica 
rcat  againm  each  other  and  tbua  form  tbe  ardi  of  Corti,  which  oovcrs  Uie 
ecftlrtii  rjMiee,  (Ki)(.  '2\fi.)  ThcM;  rMwii  are  caller]  tJie  inurr  and  otttrr  rods, 
orpillaniol'Curti.  Fnmi  the  itu]ierinr  extremity  of  both  the  inner  and  outer 
rods,  Gnf^er-like  proeewn  project  externally.  At  ibetr  \mm»  c<irrv9|Hjtiding 
to  tl»e  oentral  »|)ince  are  Mnj^le  mwii  of  nitcleatcd  cells.  On  tbe  iuiprnal  oide 
of  Ihe  inn«'r  riHl  i*  a  »ing}e  row.  and  on  the  external  aide  of  the  outer  roda 
■re  tlirve  rows  nf  elongated  cilialol  cella.  Extending  neniM  the  top  of  tho 
oi^gan  of  Corti,  from  the  iuner  hair-oelU  to  the  external  wall  ul'  tlu-  onal,  t» 
■  very  delicate  alructurc  called  the  rtlievhr  memhrane.    The  auditory  nenro- 


<  Ttw  tiMtr  Matx  b  iJlililMl  inEo  two  iwn  to  ■  menilinniiut  ntUlhMi,  tka  uqa 
aallaa  >te  •»>■  lotituu .  Uia  oibw,  duciw  cueiiksti*  iri§.  Mt). 


of  wklcb  ti 


RBABINO,    BMBLL,    A!fD   TA8TB. 


H 

^ 


fibuiMtato  probcblj  lerminalc  in  Dw  ciliated  oella,  bring  (tiliroueljr  onnsceud 
itilh  the  riliii. 

Tbo  OHM'oii"  ItilijriDth  i»  Matii  br  ■  fibro-M-rniu  ntvitibrimr  whieb  WcMn 
u  wutcjy  fluiil  called  Utc  ptnlgmpk.    Tbc  perilymph  fills  ihe  tcaJa  of  iJU 


PM.Mt. 


ADuo«AXor4«iCTK«orniiTiuiirnii:C^.iiitiKiuM.Hi.  (UuHAoI  tmm  lUmt 
«r,  «■!•  Tvtlbull :  ST.  wala  l;in|iinl ;  ft;  «ml  nf  Ibc  rorlik* ;  I,  neuitn**  uf  tt^mm 
MVhlwr  ■•ni'i-buf  ibgaa<llr->r;DMT«:  t.  Iiini1iu«|<lnillii«n>!  1.  i-tanon  •Mn'iiinni':  a.  W 
flnUruiMa;  b.ii>1<.-'»i|iInLll<:  M7iD|«nl>'ll|.atihi'(iilp<ii  trJnlM:  ■!.  iBiKrtodc^  uidl :  ».« 
mdi«f  Cunt;/.  IkiulB*  rvlirutul*.  i.  In»vr  halrcvlti;  «b,  B«mlinH  taitlulii  mT.\ 
(MnUp.oululMlT-nllti  M.cvutml  mbp*  LtUKmih*  m*. 


F>o.;n. 


FnWt. 


Fm  mt.— Pxraotii  iMoii  Piinr  Bntcrm  n  saov  nil  iiai>um>n  Livruiini  ra  n^a 
IBatMaiir.)  n.niiilt  mc:  ft,  lixitalub-.  r.duotui  camimi;  ■!.  U>a«  wo  or  atiMv:  i.  Iliiilttil 
/. ■iDIolIaiy «DUii<niiMil>oiiaMBlolm>Ju lube:  g. •MDlaln''ilit  ioIk. 

now.— p«muMmooi«r!tiBna  toTiii  umitiwiisLdiiivnjyTit.  iiiBmnn.i  «,u«n«i»tt> 
Minute:  t,  Dcm  rMMtDf  ib>  umiiuUiirT  tmlBrtniviii  rm  ■  «imlcltriilar  lute:  «,bn«(b4f » 
ncm  •ulartni  tUa  bitci  n<  o>  nirttlt. 


PHYSIOLOGICAL    ANATOllV    OP    TtIK    KAK. 


»4fi 


eoebles,  nnd  nirrouods  the  liueluf  foMrnriA  nnd  th«  tDembranous  portions  of 
llie  Ubyrinih,  which  an  iiUiatcd  in  the  vo*iibule  and  sttmicirciilu-  c&aala. 

The  memlmiHoug  fubyrinth  ia  a  closed  sac  conuattog  of  the  ecmictreular 
oDals,  D  vestibular  porlioD.  and  the  ductus  oochlMlia  of  the  cochlea,  llie 
f«iiiicireu]nr  caiuila  arc  of  the  bbido  fom  U  tht  OOMOUfi  canals,  and  arc  coii* 
taiueil  u'ithin  ihera.  The  vestibular  portion  OOnKSto  of  an  expanded  body, 
the  ufriWtr,  and  a  smaller  body,  the  meevh.  The  utricle  is  eitualed  at  ibe 
fuvi^  h«a)iellipiica;  the  eeniicircular  canals  open  on  ils  internal  surface. 
The  saccule  lies  at  the  fovea  heuiispherica ;  it  ia  connected  with  the  ductui 
oocbtearts  by  the  diiettu  rcunifiu.  In  tlie  walla  of  the  saccule  and  utricle 
are  two  calcareous  bodies  called  the  oUilUht.  The  walla  of  tlie  auipullu, 
according  to  Bowman,  alao  contain  aome  graiua  of  a  HiuiUr  aubUaiice.  The 
walls  of  the  inembranoua  labyrinth  couaiat  of  a  fibrous  ti»ue.  lined  by  pave- 


-^^^ 


:*  -t 


PUOUHOFTUSllOIISOrTSHIinitTtOHOrTHI  ACDITOKT  KKM  t  IX  TVK  A>rri.Uia  UD  JUlTVU. 

1.  Uwnllorthcaoipulla:  l.nraotarelaslMMiiwnt-iiMtiibtiiae:  >.(taulil]r«iiil(MFNl  nenv-Bbta 
I  a  I  In  I  Wllilw  UBTenliia  llie  baxnieiit-meiubmnc .  ^  pIcilDirui  iiDloii  ot  itac  n(rT»6lMcs  <rllb 
Inimfaiwa  nwW :  a.  ftullbrni  Mil*,  wliti  micJuiw  uul  ituk  fibni  In  (bait  Iniolai  T.nppgrtlai 
«lUi«.andUMTt«lm. 

mcnl  nucleated  epilWium  ot-lls,  having  a  elmcLurcIuK  baMnuint' membrane. 
These  cpilhelial  cells  arc  much  niodilicii  at  the  placo  of  CDtranc«  of  the  tibrca 
of  thii  BuUilor}-  nerve.  The  vestibular  branches  of  the  auditory  nerve  are 
distributed  to  the  ampuUie.  utricle,  and  saccule.  ( Pig.  24^.)  In  tV  utricle 
and  the  saccule  the  fibres  terminate  in  oral  plates,  called  \\w  m'lfida  ttetutica, 
which  are  more  or  lees  colored  by  the  de]>oeitioii  of  yellow  pigment.  In  the 
anpalba  the  libree  terminate  in  elevations  called  the  rrube onuti'oce.  After 
tbe  ncrve-fiUtnent  pierces  the  membranous  wall  at  these  poiole,  the  aiig* 
cylinder  alone  pooetratee  the  baaement-membrane ;  it  then  forms  a  pleiusof 
delicate  oerve-flbrw  with  nuclei,  and  finally  terminates  in  fusiform  epithelial 
celb  whicb  have  tenuinal  cilia  called  the  auditory  hairs.  (Fig.  249.)  I1ien 
dliaicd  cells  are  suptiorted  by  ooluniuar  epithelium., 

00 


HG 


HBARIKO,   SMBI-t,    AND  TASTE. 


The  tnembninous  Inbyrinlh  \*  lined  by  pulrgonal  oucl«ftle<l  e{HUieiiua, 
vhidi  mcfCtM  Ihe  em/o/ym/i/i  wliioli  &\l»  ib'e  aac] 

At  in  the  ejc,  ao  in  tbc  eiir,  vre  have  to  deal  fini  with  »  mrrv  of  tpttkl 
Mnr,  the  MliinulatiDii  »!  which  givM  rite  t«  ■  RjHTiul  •rnmlion :  woundiT, 
vith  lerniiiinl  orgaon  ihrougli  which  the  ph^cal  channs  (impt-r  In  iW 
spodal  «-ntK>  arr  rnalilcd  to  act  mi  (hv  i>vrve;  nod  ihirdU.  with  luUidiuy 
nplioniluR,  by  whifh  tbc  MMrulncM  of  the  tviwr  i»  incnrnwil.  TIm-  n'lilnl 
ciinni'diniif  "f  the  nitilttory  ii«r\-c  are  nuch  thnt  whenever  llie  auililitry  libra 
tin  iitiniiilnlol,  whclher  by  inc«n!>  of  the  tcrmioal  (>rj{iin»  in  lite  usual  an 
or  by  ibi;  din-rt  Eifi|ilicali(in  i>f  utinnili,  t-lcclrical,  ntcrhiiniml.  vie.,  thv  tnult 
a  always  a  Ki-iioiitiQD  of  •ouiid.  .Iimt  n»  etimulalion  of  ibc  <mlic  fibtn  ft> 
ducw  nn  other  Mnxattun  than  llmt  of  li^hl,  foRtimulatton  of  ihe  auilituq 
fibre;'  prixliiiT*  nn  nlhcr  M-nntiou  tlinii  that  iif  fumul,'  Tbc  terminal  orgui 
of  ihc  niidilory  ncr\'c  arp  of  two  kinds :  the  com  plica  lod  orgno  of  Corti  ia 
the  oocblca,  and  ihc  epithelial  urningcmcntff  of  the  macula.-  and  cristv  ui*- 
ticir  in  otber  pnrti'of  the  Inbyrinlh.  Wavc»of  »oiinil  falling  on  the  auililoi; 
nerve  itself  produce  no  cHect  nhalever;  it  is  only  when  br  tbe  mediiin  m 
the  endolymph  Ibey  nn-  brought  to  bear  on  tbc  dcticalc  aiMl  peculiar  i!|hU» 
lium  eel's  whicli  coiislilule  the  peripheral  tcrininaiions  of  the  nerve,  titf 
Mnsallone  of  sound  arise.  Such  delicate  sliuclures  are  fur  the  sake  of  pof 
tcction  natiiraily  withdrawn  from  tbc  surface  of  the  body  where  lliey  wmiM 
be  sulnecC  lo  injury.  Hence,  the  necessity  of  an  acoustic  apparatus,  fbrnuDf 
ihfl  middle  and  external  ear,  by  which  itie  waves  of  sound  Afe  most  Bdns- 
lageously  conveyed  to  the  terminal  organs. 


Thf.  Aeovjilic  Appnraiui. 

Waves  of  sound  can  and  <lu  reauh  the  cndolym)ib  of  tbo  labyrioih  b) 
direct  oou'luciion  through  thi-  xkull.  Since,  however,  aononwB  vibnitiua»an 
IraDsmitled  with  great  ilitlicuUy  from  the  air  lo  solids  and  Uquidit.  and  iMal 
sounds  come  to  us  (hroiigb  Ihe  air,soRie  special  ap|iaratus  is  required  to  Ina*- 
fer  the  aerial  vibnUions  to  the  li<iuid«  of  Ihe  internal  esir.  This  apparatiu 
is  enpplie<]  by  the  tympanum  miu  il*  appendages. 

The  condia.  The  use  of  tbis,  as  far  as  bearing  is  cuncerned,  b  lo  coIIm 
the  wtivm  of  sound  coming  in  various  direclions,  and  lo  direct  then  un  to  the 
nicinhrann  lympHni.  Inourwlvta  of  niodemteserTkeualy,  in  niAnyaiuMali 
il  is  of  great  imjiortanco. 

Tlir  mnnbrana  tpiipani.  It  IS  a  chnracieristic  protierty  of  slreuJied  mem- 
hninrs  that  they  are  reiulily  thrown  into  vibraltuu  hy  ai-rial  wavca  ufwaad 
The  membrann  tympsni,  from  iis  peculiar  conformation,  being  funnel-tfaa^ 
will)  a  deprcsevd  centre  surrounded  bv  sides  gently  convex  outwan).  ia  pecs- 
liarly  susceptible  to  sonorous  vibrationii,  and  is  ni'if't  readily  IhroKn  tDb> 
corresponding  mnveoieula  when  waves  of  sound  reach  il  by  the  meatus.  H 
has.  moreover,  this  useful  feature,  ibat  unlike  olher  mrelclied  metnltnina,It 
has  no  marked  note  of  its  own.  It  h  uul  thmn'o  inio  vibraliona  by  want 
of  a  pnrlicular  length  more  readily  tliau  by  othcn.  It  answer*  eqaallj  aiM 
within  a  coiisiderabit!  range,  to  vibraliuus  of  very  difierent  ware-teogik. 
Had  it  a  fundamental  tone  of  iu  own,  we  should  bJde>iract4>d  by  ibc  pruM- 
i>encc  of  thb  note  in  mi»t  of  the  sounds  we  here.  When  sounds  iuijiiu]^  o 
the  solids  of  tbe  bead,  as  when  a  watch  b  held  between  tbc  teeth,  tbe  nina- 

I  It  will  b*  M«n  Ut»t  on  itikt  llinv  an-  rraKini  for  llilnkliw  ihsi  impnlaa  [i*M>ia  slMaM 
sndllOTT  Mnr  may  fiva  na«  U  Mktr  Mncu  tlun  auiiiiary  MnMltont, 


rOTSIOLOOICAL  AITATOMT  OF  THE   BAR. 


I 


I 


I 


liniw  lymponi  u  Mill  fiini:ti<iiiiil.  VibnttiDiM  ara  cunvoyM  rrnm  the  trm- 
|>onil  IxiCie  to  it  anil  bciici-  pnm  in  th«  tiituiit  wny,  in  lulililiuu  lo  thotu 
tmoeioitlvd  dirvclly  iVoni  ihv  ixinv  to  (W  [>orilrm|i)i. 

T/ie  audilori/  tuvii-Je*.  Tho  niallou*,  tlio  IihoHIc  of  which  ilMConding  for- 
wanl  Mid  inwBnl,  it  itllBchcd  lu  the  meinbrnnn  tympntii,  unti  the  incus,  whose 
long  proccM  i*  connected  l>y  meaoH  of  its  ob  orblculure  or  leiiliculnr  procee) 
aoo  lh«  ilat>es  to  tli«  leneMru  avalis,  form  toj^lhcr  n  body  which  rotates 
rouod  lui  MM,  poaiiDg  through  lh«  ahurt  proccn  of  the  incus,  tb«  bodiiw  of 
the  inciM  nod  nislleus,  and  the  proccMua  ^racilia  of  the  mullou?.  When  the 
nallciiii  IB  curried  inuard,  iho  incus  mtive^  inward  too,  nnd  when  ihe  midleu* 
returns  to  its  p«ilion,  the  iiieiia  returns  iiiih  it.  lh«  peculiar  andille-aliaiie'l 
joint  uith  iia  catch  ie«ih  ])erniitlin^  thin  maremenl  readily,  hut  preveniinjj 
tb«  stajiM  Itcin^;  jmlled  buiked  when  (he  membranu  lympaiii  "ith  the  iukI- 
leua  is,  fur  any  reason,  purthvd  oulwanl  more  than  usual;  the  juini  thep 
gttpw,  so  as  to  permit  the  malleus  to  be  ii)i>ve<l  alone.  Various  lignmeuta. 
the  superior  or  suspeoii'iry,  tinlerior,  mid  vxterual,  also  aerve  to  keen  the 
iDalleuB  in  place.  The  whok-  Kcrit-*  of  ONiicled  luaj  be  resorded  bb  a  aliigle- 
anii«<l  lever,  moving  on  the  li^'amenlal  lUtuchmenl  of  the  wort  proceM  of  Ihe 
iticii!^  lo  the  poDieriur  wall  of  thu  tynuiununi,  the  weight  lieing  bruu)[ht  lo 
lieor  at  tli«  end  of  the  hmg  pruuiM  of  tlie  Incua,  nad  tM  puwer  at  the  «ad  of 
ibe  batidte  uf  the  inallcu*.  Tbu  long,  uwllual  arm  of  thu  l«ver  is  utiout  i>^ 
tnni.,  the  abort,  «tapvd)a1,  61  Diai.  in  length;  htiice,  the  movcmcnla  of  the 
Ma|)e*  ore  lew  than  thcwc  of  the  tyiiifmniim ;  but  the  Uw*  in  nmplitudv  b 
toade  up  by  a  gain  €>f  force,  which  is  in  itcvlf  no  obviotia  odvuiitAge. 

Thus  e^ery  movrDieat  of  the  tvnipniiic  membrane  i»  traiismitti»l  tlirough 
ikik  chain  of  omiclva  to  the  mcnibmnc  of  the  fenestra  ovaliii,  and  so  to  tb« 
iwrilymjih  of  ihe  luliyrinth:  the  vibraHoiis  of  the  tympanic  membrane  nno 
conveyed  with  Increu^U  iut^usity,  though  with  dimiiiiBhed  amplitude,  to  the 
latter.  That  the  boms  thua  miive  tn  nuute  bas  beeu  proved  by  reconliuj; 
their  moTcmcnIs  in  the  usual  L'raphie  melhod.  A  very  light  style  attacheal 
to  the  iaeua  or  atspM  is  mudi-  to  write  on  a  travelling  surfaoe;  wheu  the 
niembrsna  tymiwiii  u  thrown  iuf f  vibratiouit  hy  a  sound,  the  curves  dewribed 
by  the  style  indicate  that  the  chain  of  bouai  murea  with  erery  vibration  of 
llie  lynipanuni.  Uu  the  other  hand,  the  comparatively  looee  attach  men  bt  of 
the  several  buiiM  is  an  i)lj»iuele  to  the  mulecuUr  traiisuiisaiou  of  wmoroua 
vibrations  ibruu;{h  them.  Moniivcr,  auuoruui  vibrattona  can  only  l>e  truna- 
initied  lo  or  puiu  ahmg  such  bndie*  as  either  are  verv  long  compared  fu  the 
length  of  tile  souiid-»avn,  ht,  us  in  the  owe  of  membranes  and  striun,  have 
one  dimeoaiou  very  luuvh  smaller  thim  thi;  ullivra.  Now  the  bun«A  in  ijuoi- 
tioD  are  not  e«[wcially  thin  in  any  one  dimvnsiim,  but  are  in  all  their  diinen- 
sioos  exceedingly  small  c»m|uircd  with  ihu  length  of  the  vibratious  of  even 
the  shrillest  sounds  we  arc  capable  of  hcjiring;  hvucc,  they  inusl  be  usdesa 
fur  the  molecular  propngnlimi  of  vibrations. 

Tltt  lauor  lymjtani  mu*i-lf  even  in  a  ipii<9cent  state  is  uf  um  In  prevmiing 
the  ntcinbnina  tympani  being  pushed  out  fur.  When  it  cunlravt*  it  render' 
the  ni<-mbran«  lympaui  nioro  ten*c  and  Ix-ncc  haa  tiaen  *up|Hwci1  to  act  m 
a  ilam|K-r  lenseniDg  ihc  amount  of  vihrnliou  of  the  memlirone  iu  the  esse  of 
too  |K>werful  soumls ;  it  is  aaid  to  be  rotidily  thrown  into  contraction  at  the 
commencement  of  a  sound  or  noise,  but  to  return  to  ri-sl  during  tiK  conlinu- 
BUee  of  a  mufical  note.  Klferenc  impulses  roach  it  lhr\iiigh  tibr«s  uf  the 
liflb  nerve,  and  ila  activity  is  regulated  by  a  reticle  action.  In  some  pemoa 
Ihc  muscle  eeeoM  to  l>e  partly  under  the  dominion  of  the  will,  since  %  peou* 
liar  crackling  noise  which  these  persons  can  produce  u  pleasure  appears  1» 
bo  caused  by  a  contraction  of  the  tensor  tympani. 


94S 


IIEARINO,    SUEItL,   A>-D   TASTC. 


The  so-called  lasator  ivinpani  ia  coDBidervd  to  be  not  a  miucle  at  kII.  hui 
a  |iKtt  of  the  ligainentoUfi  Buppvirtu  of  th«  lunlleuA. 

The  ttaptdioM  muneU  h  su^i^i-iAed  to  regulate  the  movcineats  of  the  alapo, 
iiud  t^jienally  to  preveut  its  baae  bein^  driven  too  far  into  the  feuestn  ovilii 
during  liirgu  or  Auddea  uovenneDtB  of  tne  EDerabniiia  tyiu|iani.  h  u  ((nnnal 
by  flbfee  fmrn  the  fm-M  uen-e. 

The  JCiutac/iian  tiibr.  ThU  wn'M  to  niointain  an  equilibriuio  of  pmnn 
between  the  extenml  ntr  and  ih»t  wiihhi  the  tyiuiMinuin,  aod  to  serve  ■*  u 
exit  for  the  secrelionH  of  that  cavity.  Were  the  tyoipaiiuto  peraaiMntlT 
clcmed  the  viliratiitnB  uf  (he  ineiulirana  tyiiipaiii  would  l>o  irijiiriouKlyaAdel 
by  variatioDs  uf  preraure  occiirrlu^  either  itnide  i)r  outnidc.  Tbe  KaHtacklu 
tube  i»  undoubtedly  open  during  twatloviug,  but  it  if  Mill  iliii|iuieit  wfaeiber 
it  remaina  permaDeiitly  oiieii,  or  it*  opctied  ouly  ut  inierTiil* ;  probably  i|  a, 
at  imift  liitieri,  iieilhcr  widely  open  nor  clowly  *buu 


Auditory  Snuationt. 

tUit-U  vthimtion  ommuiiictiled  by  the  itapes  to  iho  poritympb  trareltaii 
ware  ovpr  the  vrftibulc,  tbt-  Ronii circular  canals,  luid  other  p«rte  of  the  labr- 
riuih  ;  and  from  (he  iwrilymph  is  iranBioittcd  through  llic  menibrunous  wbOi 
to  the  endolymph.  From  the  vestibule  it  passes  on  iuto  the  t^i\a  vcetibuli  of 
the  cochlea,  and  drsc!cndiiig  the  scnln  lympani,  ends  as  an  impulse  agaiail 
the  iiieiiibrano  of  the  fruentrn  rotunda.  lu  the  regions  of  the  luaculie  aol 
erialie  the  vibrations  of  tbe  endolymph  are  supposed  to  throw  into  eon*- 
spi'iidinj;  vibrations  the  Bo-called  auditory  bain.  In  tbe  ODcblen  tbe  vibn- 
tiona  of  the  perilymph  are  suppo§eil  to  throw  into  vibmliooB  lite  hB«lK 
membrane  with  the  ituperini{)0»&d  orj^u  of  Card,  consisunc  of  il 
Corli  with  the  inner  and  outer  hair-oelU.  Tbe  vibrationii  iIiu.h  tr 
to  these  ttructurts  zive  ritie  to  nervou*  iuipulstd  in  the  term  I  nii  tiona 
auditorv  nerves,  and  thew  impulMV  reaching  certain  pariH  of  t)Mi  braio  fl*- 
duov  wfiat  we  call  uudif)ry  Kunatioii:^  We  are  aovuatooied  to  diviile  oar 
auditory  aeinuitioni  into  ihrwe  caiiited  by  noiso*  and  ihottt  cauwcd  by  miwial 
mund*.  It  L>  the  charactcriittio  of  the  littler  that  the  vibraiiona  wludi  eaa- 
»litntv  them  ariT  |n-rti>[lical ;  they  occur  and  recur  at  rt'gular  inierVKli.  Win 
no  mnrkt'd  jii-Hndicilv  in  jircseiil  in  the  ribration*^  when  tbe  repntltioa  of  tbr 
wvcrnl  vibnilicinM  U  irregular,  or  the  |>erio<l  »n  complex  Ha  Dot  U>  ht  nti/Sij 
apprecintt'd,  ihr  upmrntiun  produced  i»  that  of  a  miisr.  Tliere  u,  bow«T>r.tW 
abrupt  line  belwom  the  two.  Itelneeii  a  pun;  nud  rimple  musical  SMtai 
jiroduocd  by  a  iK'rii-a  nf  vibnittons  each  of  which  hnit  exactly  the  same  wb»»- 
length,  lutd  a  hnn>h  noi»e  in  which  no  conHUCtilivr  vibniiioiis  may  be  atikft 
there  are  numerous  intcrmt^dlale  #tagea. 

In  l)oih  tioi«m  and  musical  «oiind«  in  nongiiiite  a  character  wbicb  w«  all 
loudncM.  This  I*  dctertuiocd  by  the  amplitttdr  of  the  vibrations ;  i^  gnaut 
the  distiirbanoe  of  tbe  air  (or  other  ined!i)ni)  the  louder  tbe  sound,  la  ■ 
luusical  sound  we  reeogniiu?  also  a  character  which  wc  call  pitch.  Thit  II 
determined  by  the  wavedcnglh  uf  the  vibrations ;  tbe  shorter  tbe  waf» 
length,  ibe  larger  the  number  of  consecutive  vibratioiM  which  fall  unoutfe 
ear  iu  a  second,  the  higher  the  jiilch.  We  are  able  to  sj)euk  of  a  wbide  ssis 
of  tones  or  musical  snunchi  of  diSerenl  pitch,  from  tbe  lowml  to  the  ht][bcC 
audible  tone.  And  even  in  many  noises  we  can,  to  a  certain  extent,  nof 
uixe  a  fAuih,  indicating  that  among  the  uultifarioiu  vibratlonii  tliure  its 
periodicity  of  certain  groups  of  rtbratiaiis, 

l,aDtIy,  we  diatiuguiah  mtuical  luunds  by  their  quality;  tfao  wune  Ml* 
sounded  on  a  piano  and  on  a  vioUu  produce  \'ery  dtlfereut  seoMtions,  «na 


PHTSIOIOOICAL   ASATOJCT  OF  THE   BAR. 


ul)«ii  H  arrir*  of  vihratimu  having  in  vnc\i  ctvte  Lhfi  Kuav  periorl  of  rrpctitioii 
b  wt  lulling-  Thi«  nrJMfl  JVnni  the  fuct  tlmt  the  mimical  soiiods  gcaeratcti  \ty 
noM  miuiciO  ingtniinrnls  lire  not  siniplo  but  coniDDUti'l  vibnuiooa.  Whcti 
lb«  notv  ('  ill  the  treble  for  instiiiico  is  rtriick  on  tne  piano,  xni)  wo  anmlym 
ihv  tolnl  MHiDi),  u'c  liml  tlinl  it  cnn  be  resolved  pnrtly  into  w,  terics  uf  vibra- 
liuiw  with  a  period  cbumcteristic  of  th<3  pur«  time  of  tbo  treble  C,  and 
MTtly  into  other  aerie*  of  vibration*  witb  perimle  charact«ristic  of  tbe  C 
in  the  nclave  above,  of  the  G  nbov^  that,  of  the  C  in  the  next  octave,  and 
nf  the  E  niMve  tiiaL  And  the  Mii»tiuii  which  we  anooiate  with  ihe  wiund 
of  the  treble  ('  on  the  piano  is  detemiiDcd  by  the  characleri  of  the  complex 
vibration  arising  out  of  these  eeveral  eonetitueiit  simple  vibrations,  A-lmoM 
nil  musical  sound*  are  thus  composed  of  what  is  called  a  "  lilDdaneatal 
tone  "  ncoomjMtnied  bv  a  unniber  oi  "  overlones."  And  the  overto&M  tary- 
in;r  in  number  and  relalive  promiiience  in  diflbrent  inslrumeDta,  f;ive  rise  to 
a  diflerenoe  in  the  sensation  caused  by  ibe  whole  t^me.  So  that  while  the 
fundamental  tone  determines  the  pitch  of  the  aound,  the  quality  of  the  sound 
is  detennitied  by  the  numlier  and  relative  prominence  iif  the  overtones.  In 
a  sontewhnt  similar  way  we  di^tiui;niiib  ibe  <|ualiLy  of  noises,  sucb  as  a  han;;- 
iag,  crackling,  or  rustliDji;  iKiise,  by  an  ajipreciaiinn  of  siiilden  or  irregular 
cfaanges  in  tlie  amplitude  and  |>oriijd  of  the  cimstituent  vibrations. 

Since  we  have  a  very  considerable  nppredalittn,  eaiiable  by  exercise  of 
aotonisiiiflK  enlar^niem,  of  the  loudu^wi.  piieh,  au<l  ijualitr  of  a  wide  ron^ 
at  noises  aiid  umsieul  »)undd,  it  is  dear  iliut,  within  the  limits  of  hearing, 
each  Tibration  or  serieit  uf  vibrations  must  prixJucc  its  tSix%  on  the  auditory 
Dcrree,  according  to  the  measure  of  its  intensity  and  period.  Out  of  those 
eiffierU,  out  of  the  sensiiry  im^iiilsM  to  nhicb  the  several  vibratiuas  thus  give 
rise,  are  geuenttud  our  sensiitums  of  the  n'liso  or  of  the  sound. 

The  vibrations  of  a  musical  sound  (und  tinoo  noisea  an  oo  tmperf<Ktljr 
undentiXN),  we  may,  with  benefit.  cbieHy  coulin«  outwivca  to  rousicu 
sounds),  as  they  pa»  through  the  air  (or  other  medium  i  are  not  discrete ; 
the  vibration*  rorrwpoDding  to  the  fundnmenlnl  lone  and  ovsrtooes  du  not 
travel  as  so  many  separate  wave*  :  ihey  all  toj^ethor  f^irni  one  complex  dis- 
turbance of  the  medium ;  and  it  ia  M  one  miapo*it>-  ware  that  the  sound  blla 
on  the  membraaa  tympani,  and  paasing  through  the  auditory  npptiratus, 
bnaka  on  the  terminations  of  the  auditory  nerve.  vVnd  when  two  or  more 
munotl  sounds  are  heard  at  the  Mme  time,  the  same  fusion  of  tlie  waves 
occurs.  iJince  we  can  di»tinguidh  several  tooea  reaching  our  ear  at  the  same 
time,  it  ia  clear  that  we  must  poeseaa  in  our  minds  or  in  our  ean  some 
ninna  of  aaalriiiigtheee  composite  wares  of  sound  whieb  full  on  our  acoustic 
omins,  and  of  sorting  out  their  constituent  vibrations. 

riiere  is  at  liand  a  simple  and  easy  physical  method  of  analysing  eom- 
jMiaite  Buumls.  If  a  person  standing  before  an  open  piano  sings  out  any 
note,  it  will  tie  observed  that  a  number  uf  the  strings  of  the  piano  will  be 
t]in)«n  into  vibration,  and  uti  esamin^tiou  it  will  be  found  thai  tb'^-'  strings 
which  are  thus  set  gi'ing  e<>rn-ii)ioi)il  in  pitch  to  the  fundamental  tone  and  to 
the  several  overtones  of  the  note  ^uug.  The  note  sung  reaches  the  strinj^ 
oa  a  complex  wave,  but  tha»e  string*  are  able  to  anolyxe  the  wave  into  iia 
OMHtituent  vtbrutiouD.  uich  siring  taking  up  those  vibrations  aud  those  vibra- 
tlofwonly  which  Iwlung  to  the  IuUl-  giveu  forth  by  itself  whun  stniek.  If 
va  s«[)|mmn;  that  tuich  tenniunl  fibril  of  the  nuditiirr  ner\-o  is  connected  with 
an  organ  so  far  like  a  piauo-slnng  that  it  will  readily  vibrate  iu  raspODse  to 
■  Strics  of  vibralin;^  iiiinulnugi  uf  u  given  |ieriod  and  to  none  other,  and  that 
we  poascw  a  numbrr  ot  nuch  terminnl  urgiuu  :iutBcicnl  for  tl»e  Bnal)rsis  of 
all  the  M>nDds  which  wv  can  analyM-,  and  that  each  terminal  urnn  au 
affected  by  particular  vibrations  give*  rite  to  aaensory  impulse  aud  thus  to 


9fiO 


HKAHINO,    S»EI.L,    AND   TASTE. 


a  ectiBnIton  of  a  rfUtincl  ch«i«rter — if  we  Mipp-Jse  thew  ftrfrnna  toexitt,  nur 
a  j>|  I  red  at  ion  of  soumlii  in  in  a  larpv  moasHre  cxitlaiiiHl.  In  Um  Offu  ol 
(  orti  w*  find  Mnictures  lUe  nrraniieiueiil  of  wliioli  irmutiblr  sajuilll  to  m 
lliiit  tli«e  lire  tlie  organs  »'e  are  sei^ltiog.  We  have  only  to  BiiiiiHoe  thai  nf 
the  long  series  ff  mda  iif  Ciini.  vnryiog  rejrulariv  as  these  ih>  mmi  ib«  }**■ 
t'lm  to  the  top  of  the  spral,  in  length  and  in  the  a|ian  of  their  arch,  radi 
|)air  vrill  vibrate  in  rm>i>ii»e  m  a  iiarticular  lone,  and  the  wlioI«  aiaiitt 
•cenu  explaiiiei).  But  the  more  the  imhject  i*  tiiqiiired  into,  the  more  do*- 
]>lex  and  diliicrult  it  n|i[ii-ani ;  unc}  we  are  obliged  lo  conclude  that  the  ma 
pUved  by  the  r»dH  of  Uorti  is  only  a  (ubordintite  part  of  th«  Ainclion  uttb 
whole  organ  of  C'orti. 

!n  dit  firM  place,  it  is  rlifficnit  ta  see  hnw  the  rmfe  of  Corti.  even  If  lh»f 
are  thmnn  into  vi1miti«ii,  ran  rirSginaie  wntory  irapulKS.  for  th<<  fihriU  of 
the  aiidiUiry  ucrve  (erniii)Bte  in  the  inner  and  niiter  hnir-ecll*. 'nd  illth 
thCM  cell».  nnil  not  along  the  oonrw  of  Uio  fibril*  w  lliey  |MMt  umler  ui 
b«tiroCD  the  rodn  of  Corti,  thai  ihc  »en»ory  impitlRi*  must  iMtrin,  In  tl4 
Mvoml  place,  the  variation  in  length  of  the  fibrm  along  the  »ork»  is  itmfl- 
rient  for  the  work  neHgiioi)  to  tnem.  Monrover.  they  appear  not  lo  bt 
elastic.  La«lly.  they  are  wholly  alMrnt  in  binK  who  vcn'  cWrty  can  appn^ 
date  muRical  Rounds.  This  Wt  fact  proves  indubitably  ihni  the  rocli  ia 
ijucilion  arc  not  nbsolutelv  cswniial  for  the  rconiftiition  of  tones.  In  tk 
Aice  of  those  ditlicult)i.>s  it  "has  been  sii^estcd  that  tlie  h«eilar  membruu. 
which  ifi  present  in  hirdt  as  well  as  in  mammals,  and  whieh,  beioj;  tow 
radially  but  loose  longitudinally,  i.  e.,  along  th«  spiral  of  the  oocbW,  mat 
be  considered  as  congisting  of  a  number  of  parallel  ndial  strings,  eacn 
capable  of  inde|>endent  vibr«linns,  is  the  soughl-for  organ  of  nnnlyDtt:  fcr 
it  may  be  shown  niathematically  that  a  menibranA  to  stretched  in  oae  dinc- 
liou  only  is  copablu  of  vibrating  in  such  a  manner.  And  tlH>  mitial  disKO- 
duns  of  tho  basilar  membniue  irive  a  much  greater  range  of  ditTcrence  tlun 
do  the  riuU  of  Corti,  diminishiu);  in  nmn  doirnwanl  fh>m  0.495  mm.  at  thi 
Uip  to  (l.(M12S  mm.  near  the  bottoiu  of  the  spiral,  whnn^ut  tbc  diirerrnu  ia 
kngth  i>r  the  latter  'a  iiimnly  thut  lielweeii  O.lMFt  and  0  085  mm.  for  the  inatr, 
and  betwt«n0.01!>  and  0.08,1  mm.  fur  the  out^r  libra.  Aocordtngti)  this  rirw.a 
parlioular  Kimpli-  viliration  rciidiiu^  the  s>;nla  tympaui  of  the  cochlea  iknxi 
into  sympullu-tic  vibmtii<ti!>  a  Ktniill  purlion  of  the  b^iiilar  membcaop.  ih* 
f-ibrat40DB  of  which  in  turn  so  affvet  [be  stnictun^  overlying  it.  that  acnaan 
impulses  arc  gvncnitrd.  The  K-nfory  impulses  reaching  the  brain  gite  Hm 
to  a  corresponding  scnmlion  of  n  particular  lone. 

The  remarltabfo  reticular  ni<^nibrnnc  which  has  such  jieculiar  relatloai 
with  the  hair-cells,  and  thri>ugh  them  with  the  bA*ilar  membrane,  must,  am 
might  imagine,  have  s>~>mG  specini  funi'tion  ;  but  it  is  impis*ib]e  at  preatui 
to  assign  to  it  niiy  satisfactory  duty.  The  structural  arrangemeuls  te*m,H 
anything,  to  indicate,  that  when  a  segment  of  (he  basilar  niembraiie  h 
ihniWD  into  vibrations,  the  overlying  hair-cells,  reticular  meuibmuc.  aad 
rods  of  Corti  vibrate  en  miate  with  it.  Itul  this  renderst  Ite  whole  inaiur 
still  more  diflicult.  Indeed  the  whole  subject  is  in  the  highest  ileartw  nb- 
Kctire,  and  the  moat  we  can  say  is  that  the  organ  of  Corti  as  a  whole  wnw 
lo  be  in  Home  way  cannected  with  the  appredalion  of  tones,  but  thai  tf 
present  it  in  very  hanirdoua  to  attempt  lo  explain  bow  it  acta,  or  to  naign 
particular  ftiDetinna  to  puriinitar  pans.  The  disliuciiun  between  the  iiMr 
and  outer  hair-cells  seeiua  to  be  very  parallel  to  that  between  the  rode  and 
the  concjt  uf  the  retina :  but  even  tbia  analogy  may  be  n  fallacious  one. 

It  hit*  l>een  observed  thai  among  the  niiditor^-  hair*  of  tho  cnis 
•Mnc  will  vibrate  to  particular  notes;  hut  the  auditory  luiini  of  tbe  ma 


I 


I 


■ra  fur  loo  muL-ti  of  tlie  Mine  length  to  permit  the  BUppoeition  tliat  tlioy  can 
set  ■■  or|;ni»  of  ftnalnis. 

If  the  organ  of  C<>rli  ia  the  mmnB  bj  nhicli  m  B|>prcciiitB  tones,  it  ia 
pviilent  that  by  it  also  «e  must  bv  able  to  e«tiniate  loutlocas.  fur  the  quality 
of  a  muHiral  sound  is  dependent  on  the  relative  intenBity.  ae  well  oa  ou  the 
tiaiure.  of  the  overtones.  Anil  since  noise  ii  nl  best  bill  omtu^  niueic-,  the 
cochlea  iuuh  be  n  nieaiii  of  apfireciatin);  noises  as  well  lu  si>iiada.  Uut  this 
wonid  leave  iiochiuj;  whatever  fur  the  rest  of  the  labyiinlh  to  do  in  respect 
In  the  appreciation  of  sound  Aave  to  far  as  the  diKerenoe  in  etruc'Liire  betwoeo 
tbe  blir-eella  of  CVrti.  with  ilieir  short,  thiek  nnia,  and  the  hair-Iteariiifc 
Mruciurei  in  the  inartilw  and  criHlie  with  their  ihiu,  deliral«  hair^,  may 
pceeiblv  iiidieale  a  diflerence  of  fuuciion.  the  latter  bein);  more  eui<i.'e|itible 
to  ihe  irreitiilar  vibratinua  of  iioiMs.  That  the  veHlibule  and  sciuiclrcular 
Cuiab  ari-,  however,  conterned  iu  hearing  U  Bhona  by  ils  heiai;  tbe  only 
Auditory  orKan  in  the  icrhthvupHiila.  iiuledH  wo  su[)|ioee  that  in  the  Ui;rhi-r 
verHferatea  ita  Amotion  has  l>e«n  wholly  iransferreil  tu  the  cuchlm.  That 
tbe  wrakircular  canala  may  have  dutiuo  a|wn  fr>i(u  luinriiig  we  ahull  abow 
later  nn. 

Concerning  the  flinction  of  the  other  |Huia  of  the  luleroa)  ear  we  linaw 
very  Utile.  The  oiolitlm  have  t^wn  »up[)uiieil  to  iiiteinufy  the  vihrntioiis  of 
the  ondnlyniph  ;  but  ninco  apimrunlty  they  are  l<Hl|cvd  in  a  (luanltty  iif  rouaix 
it  u  probable  that  ibcy  really  act  bh  damjierK.  A  aimilur  daiupiug  action 
haa  iieeii  Migfniaivd  for  the  ni«n)brane  of  (^irli  (inanfimiut  leciart'i)  over- 
han^nit  the  fibre*  aixl  hair-cells ;  ao<l  some  wrilcni  have  auppoMd  that  mu*- 
eular  fibres  prewnt  in  the  plaiinin  frmiluiinre  nmy  by  tightening  the  basilar 
Bwitibrani;  serve  iw  a  M>rt  of  ni^iminiKlation  me^'hanixni. 

(It  mart,  however,  he  borne  in  mind  that  creii  niaktnt;  the  fullest  aliow- 
ance  for  the  assistance  alfor^led  ut  by  the  orfran  of  Cjrli,  the  appreciation 
of  any  sotind  is  ultimately  a  mental  act.  The  analysis  of  ibe  ribraiions  by 
tbe  fibres  of  Corti  or  tbe  basilar  membmne  is  simply  |)reHtiiiimry  to  a 
syntbeeis  of  the  sensory  inpulMS  ao  generated  into  a  complex  seiuatioo. 
W«  do  not  receive  a  distinct  aeriei  of  specilic  auditory  impulses  rMulliun  in 
a  apei-iflc  Kneation  for  every  possible  variation  in  the  wave-lenj;Lli  of  sonor- 
ous vibrations  any  wore  than  we  receive  a  distinct  series  of  speciKc  visual 
impul.-es  fur  everv  noasible  wave-leuicth  of  luminous  vibralioos.     In  enoh 

^cate  «e  have  nrobauly  a  number  of  primary  sensations,  from  the  various  ^^ 

mingtinK  of  width,  in  ditlerent  proporljona.  our  varied  complex  seoMtioaN  ^H 

aride:  the  dilli^reiivc-  between  the  eye  and  the  ear  bein^  that  whereas  iu  tlie  ^^ 

former  tbe  number  of  primary  senaatiuna  a[rpeurs  f>  be  limited  to  thrve  or 

tat  least  to  six.  in  the  latter,  inanks  to  tbe  or^n  of  Oirli.  the  number  is 
very  lar^^:  wliat  the  exact  number  i«  we  t«iinot  at  prewnt  tell.  Oiirap- 
preeiaiiuu  lor  a  sound  b  ul  bottom  an  appreciation  of  tbe  CDmbinol  etlvct 
pniduced  by  Uie  relative  iuten»itic»  ti>  which  the  iirimnry  auditory  wiuatiuos 

tare,  with  thu  be'ii  nf  ihi.-  orifitii  of  4*i)rti,  excited  bv  the  sound. 
Whatever  Im.'  inc  exjdaiiatitHi  of  tbe  manner  in  which  our  iltntinct  auditory 
•en««tiun:>  ariM.-,  the  ranjcv  and  pn-i-iiiion  of  our  aiiprei-intion  of  mutical 
•iruniU  i«  vi-ry  threat.  Vibration*  wilb  a  rocurreiici*  Wlow  'Mi  a  itocond'  are 
aoable  fi  pr'nIuM)  a  scuutioii  of  snuiiit ;  if  thi- waves  an:  [Hincrfiil  enough 
wa  may  firl  tbem,  but  we  do  not  hear  ibcm  if  the  vibrations  aa-  Hmplc,  and 
•uoli  M  would  givo  rise  to  a  pure  lone :  if  the  fundamv^ntal  tone  U  aocom- 
putiod  by  overtones  wo  may  hear  ihi-w.  an<l  are  thus  apt  to  say  we  hear  thfl 
fonavr  itdsu  in  reality  we  only  hear  the  lntl4T.  The  nota  of  the  HMbet 
organ  pipa,  99  Tibrations  a  secund.  gives  us  the  seasalion  of  a  droning 


I  B}  KmM  kutlKin  tha  llmli  M  plutil  M  tuit  u  U  w  sm  It  ■  •reoiri. 


u 


Qr>2 


nSARIK'O,    SUEM.,    AND   TASTE. 


nound.  A  tone  of  40  vibraliana  is.  lMwev«r,  qui{«  distinct.  la  Um  oUsr 
direction  it  is  pa»ib)e  to  bear  a  iioK>  caused  by  38,000  vibnttoM  •  moaai, 
though  tlie  limit  for  roost  persoti^  ia  far  lower— abmit  16,000.  Some  foum 
he*r  grave  souihIb  more  easilr  than  liigb  ones  and  vwe  vena.  Thb  idat  be 
•o  pn>nouD«ed  u  to  juatifV  tJie  subjecu  being  ifwken  of  as  de«f  to  gnn  ur 
hrjtn  loneo  reflgwctively.    'TIic  rangt  in  difTerent  aniinala  is  vewj  difliervaL 

Tbe  {Miwcr  of  iliitiiiiifuiabiti;;  <>n«  tvAf  (torn  another  varies,  aa  is  well  knon, 
in  diffeKDi  iudividiiitl*.  aeconliiig  as  ihejr  liave  or  hare  not  a  "  mu>i«l  tar." 
A  well-lmiiiix)  enr  can  iltmiiiguiiiti  ttie  dillenenoeof  a  nngle  orerenofi 
half  ribntimi  u  !i>h:oiiiI,  aixl  tlint  ilir»ii);h  n  long  range  of  DOtci-  Tbemafi 
of  an  ofdiiiary  apprecialiou  uf  um«vi  lie*  between  40  and  4000  Tibratioiu  ■ 
t)econ<),  t.  e..  ik-twmi  tiii>  luKist  baas  C'  (C,  33  vibrations)  and  the  faigltM 
treble  C  (C*  ■l^'i4  vibnitions^  nf  llie  piano;  toi>es  above  and  below  Umse, 
eveii  whei)  aiKlibk-,  tieiu^  iliatiiigiiiali<-d  from  each  other  wiili  ^reat  diffieolljr. 

When  twu  conwicutivi;  noiiiitU  fulluw  each  other  at  a  suffimeotly  short  is- 
terval  the  teiiiwtiuuii  ore  fiiwd  into  one.  lu  this  respect  auditory  sensatiua 
are  of  shorter  duratioo  than  ocular  si'iiMtiuus.  Wben  oeular  aeoMtlons  an 
reiKntMl  ten  tinm  in  a  wtcood  tliej  l)ecoine  tuiexl  (p  915),  whereas  the  licb 
of  a  [wnduliini  Ix^ting  100  in  a  fcmnd  are  readily  andibloas  distinct  autiiMk 
When  two  tiiiiing-rnrks  not  i^iiitt-*  in  luni-urtTtitnick  toeMberlbo  interfirreiui 
of  tliu  vibrntioiiii  i^vt*  riw  tmtn  idli-rnalin^  riso  and  fall  of  the  sound,  knotn 
as  "beats."  Whvo  the  tHitU  fullnw  i-iicli  'Hhor  ii^i  rapidlj  as  1^*2  in  a  seooad 
they  nnse  to  be  recovgnisetl,  that  u  to  say,  the  sensotioas  wliicb  ibey  csim 
become  fu^cd.  BeJoro  ihov  diKapp<-.ar  Ihcy  give  a  peculiar  diigresahk 
roughnm  to  the  sound.  Th«  pleasure  given  by  musical  sounds  depcadi 
larvely  on  the  sbaenco  of  this  incomplete  rtiuon  of  lenMtions. 

(. orretpoiiding  to  cntojitie  phennmenti  there  are  various  c»Mie  phraom- 
ena,  sen  Rations  or  niodiflcaliaDB  ot  HeitsatioDS  orifcinolin;;  in  the  tvmpaauni 
or  iu  iho  lai)Trinth  ;  moreover  scnsatioDs  of  sound  may  riee  in  the  auditosj 
nerve  or  in  the  brain  itself,  without  any  vibration  whatever  falltug  on  llic 
lahyriDlli. 

AnJiiori/  JudrjnenU. 

in  leekiiig  for  the  cause  of  our  visual  scosatioM  «v  invariably  rvfer  to  Hon 
external  world.  The  sensiili^in  caused  by  a  direct  •timnlalioii  of  tbo  opir 
iterve  or  retina  by  a  blow  or  ■  galvanic  current,  we  ideiilifr  with  that  caustH 
by  a  flash  of  light.  A  sensation  arising  from  any  stimulation  of  the  leA 
Hide  of  nur  reliria  we  regard  as  caused  by  oonie  object  on  tlic  right-hand  sid« 
of  our  exteninl  visible  world.  In  a  »imiliir  way.  but  to  a  luis  exietil,  «• 
project  otir  niidilary  sensations  into  the  worl'l  outside  us,  and  when  the  aiwU- 
lory  nerve  is  alfeclcd  we  seek  the  cniifc  in  vibrations  starting  nt  a  gre«ter  cr 
l«n  distance  from  us.  Wc  do  not  think  of  the  sound  us  originating  in  Um 
car  ilM'ir. 

Tiu*  mental  projection  of  the  sound  is  much  more  compleie  wlien  the  ctl 
is  stimulated  by  vibrations  renching  it  tlirough  the  n>embTanH  tv|iai)i  thn 
wlten  thv  vibratioiis  arc  conducted  by  the  BoUds  of  the  head  directly  to  ihl 
perilymph  of  the  labyrinth  When  the  meatus  extemua  is  tilled  with  duiJ 
and  the  vibmtionsof  the  membraoa  tvmpani  are  in  consequence  inivrCntJ 
with,  the  apparent  outwardncas  of  sounds  is  to  a  very  large  extent  kal: 
soun<ls.  however  caused,  seem  under  these  circti Distances  to  arise  in  tbe  eu. 
Hence  it  would  eeem  that  the  vibrations  of  the  membraua  lyiiipani.  sr 
poesibly  the  action  of  the  muscles  attached  to  the  ouieula.  givK  rise  l» 
obscure  sensations  of  nbioh,  by  themselvM,  wc  arc  not  distiuctly  conscKHU. 


953 


l>ul  nliich  DcverthelNS  lend  u<  to  juilgc  thnl  tliG  K)uni]ii  lieanl  bj-  tncans  of 
th«  lyiDpaiiiim  come  from  i>iil«ide  theenr. 

Our  judgment  of  th«  tlitttinee  of  8oiind»  is  very  liinit<^l.  A  s'lnnd  whose 
rh*ncl«n  ira  know  ap|)eare  to  ua  nenr  whon  it  is  loud, mid  Tar  olF  wtien  it  is 
Aint.  A  blindfold  pereon  will  be  usable  to  dinlingimh  bctni-ca  llie  difier- 
ence  of  inteneiiy  pnidiiccd  on  the  one  bund  by  n  tuning-furlc  l)«in}[  held 
befitre  liim,  finit  with  the  broad  ed)(e  of  (he  fork  toward  liim  and  lliCD  with 
tbe  narrow  edfte,  and  the  diHerenoe  on  the  other  liand  cauaod  1>y  the  removal 
of  Ihe  trmini;-fork  lo  a  diatanee.  We  can,  on  tbe  whole,  bctt«r  apj)rti<.'iat« 
tbe  distance  of  DoiseetbaD  of  iniiueal  sounds. 

Our  juii^nieiit  of  tbe  dlrretion  of  i)ouo<U  is  also  rerv  limited.  Our  chief 
■id  in  this  u  the  pontiou  in  whk-h  we  have  to  place  tne  bend  in  order  that 
we  may  bearthe  Bound  to  the  best  advantage.  If  a  tuning-fork  be  h<"ld  in 
the  n>edian  vertical  plane  over  the  heiid,  llioiiah  it  is  easy  to  roconpiiH.-  it  an 
beinic  in  the  median  pluDc.  it  hecomea  very  difEcull  when  the  cyn'  are  »lnit 
to  say  what  is  ita  piwitiMii  in  that  iilanci,  i.  e.,  whether  it  is  more  t«nard  th« 
ftoDl  or  luck  uf  tbe  heail.  In  tlii:>  re»i>ect,  loo,  our  appreciation  it  more 
rate  in  the  case  of  awstv  thnn  nf  niUHical  tonnds,  with  the  exn-plion  of 
pveu  out  by  the  humnii  voice,  the  ilirectiou  of  which  can  be  judged 
better  Ibaii  even  that  of  a  ooise. 


[Phytioiogietii  Anatomy  «f  the  yatat  Ftma. 

Tho  nnnl  foMse  arc  two  irregular  caritiea  nhich  oommiinipate  anteriorly 
with  tho  air,  through  the  anterior  nares  and  jMjateriorly  with  the  pharynx 
through  the  posterior  nares.  The  fo'aie  are  partially  divided  into  upper, 
mitMIe,  and  lower  air-pawauea  or  chamlwm  by  the  Buperii>r,  midiilc,  and 
inferior  torbioated  buncs.  They  are  lined  by  the  Rcbneiiterian  or  pituitary 
niueoos  ineinbrane,  which  ia  oontinuntis  uulcrinrly  with  Uie  integument  and 
poateriorl^  with  the  mucoua  membniDe  of  the  pharynx ;  and  witli  the  mem- 
Drsne  lininjc  tbe  ductannd  siuuKt*  connected  with  the  foam.     At  the  podtion 

I  of  the  <Iiatril>ution  of  the  nlfnclory  nerve  fi  la  men  l«  it  u  much  ibickiT,  more 
vascular,  jiigmetitecl.  and  Vtuvd  by  (x>liininnr  nucleated  cpitlu'liuni  crib :  tbe 
nmaining  |>urtiun  of  llir  nieniliranu  covering  tbe  fimue,  excepting  near  the 
■Bierior  narai,  in  lined  by  columnar  ciliated  epithelium.  Thin  monihrane 
coataina  racemow  mucous  glandM,  which  mctHc  mucus  for  the  jiurpoae  of 
keening  the  membrane  oonataotly  moiat,  which  i»  a  condition  cswential  lo 
perfect  ulfnction. 

Tlie  olfactory  tract  i«  a  prolongation  of  the  cerebrum,  which  terminates 
anteriorly  in  a  hulb>iu*  expansion,  the  olfactory  ganglion.  It  cunrista  prin- 
ciinlly  of  gnty  malU-r.  Thi^  ganglion  rats  upon  the  cribriR>rm  plate  of  the 
cinmoid  In'uc,  and  in  thiif  position  tends  about  twenty  filaments,  which  con- 
sist of  gray  mutter  nione.  thtvugh  the  cribriform  plate  to  be  diMributed  to 
the  piluitnrv  membrutic  of  the  upper  third  of  tbe  septum  naai,  tite  upper 
portion  of  the  roof  of  the  no«e,  Iho  superior,  an<l  a  portion  of  the  niiddle 
turbinated  bones,  i  Fig.  2d0.)  The  wliole  surface  correapouding  to  the  dis- 
tribution of  the  olliictory  nerre  is  colored  brownish  by  the  pigment  in  the 
epithelial  cells  of  the  mucous  glands  and  merohnmei  This  nig  men  ted  revion 
is  ealkd  the  rryio  ot/uetoria,  and  is  tbe  eneottal  portion  ut  Ine  niual  foMH 
ooncemed  in  olfaction. 

According  to  .Schullie,  the  epithelium  of  the  regio  etfattoriit  u  of  two 
kimla:  The  tirat  (Fig.  261,  a  J  couaisia  of  yellow  nucleated  pntoptatniic  eel' 


9t 


RKARIN'G,   8USLL,    AXD  TA8TE. 


which  linvc  a  cylimlricnl  boilr  ipmiinaiing  Al  iu  Tree  extremitr  m  k  •quuvl 
Iruncatctl  Mirfiic-c  ;  tliu  'lUier  cxtrt'tnilv  of  ihv  kxly  is  vlrvHcboc)  owl  m  »  fiW 
in«Dtou»  prolongiUioii,  which  cxpamls  inin  n  irian^ilnr  phitc  nii  it  tpmmtim 
the  eiihmiicoiis  liwiio.  Fmin  ihc  luue  of  thin  plaiv  ii  numbor  of  nUntili 
nre  ^vcii  ofl',  which  nro  pniKm^^t  into  the  mbiuiimii*  ItMiio.     Th*  wtcBti 

They  nre  »imilur  (o  thoso  just  d4v<:ribc>].  exco|icing  thiit  ibeir  frm  titrhmk 
covered  with  cilia.    Between  the  epithelium  rolls  the  oIlHvtofy  oerrcM  unt 

Fio.  aU.  run.  m. 


V 


I 


Pio.  asi).— VitRTit*!.  ftK-nnx  Of  IliuHT  N*ui.  rnnu. 
Mioimlu  OITKK  8ii>i  or  ronu.  1,  ulDirtoiy  irnct:  'j. 
oinwiory  ncrva:  3,  mlddls  lurblBktcil  taoo:  i.  lo«*r 
(iirliliisM  br>ne:  A.  Iinnrlim  Itain  Ida  dflh  n«rTt>. 
Hnncba  or  tbo  nfUi  an  kin  (liowti  In  Uio  ADWrtoc 
inrllon.   (ARor  arhoui.) 

Kn.  Ifil.— CiLu  or  nu  ULrifTOHir  Uccoi'i  HtuinajiM.   (o.  fr.  <;  kAor  acHCLas;  t,Af,  *■<■ 
LocKium  CtAkKt.) 

oat«.  These  tennioal  (ilanieota  (Jb.f)  are  lonj;.  delicate  aiructare*.  mUA 
have  a  niimher  nf  fusifurm  espanainnii  along  their  courw:  in  lh«  lar^ 
eipanaiou  is  fuuiid  an  uval  nucteu*.  The  tcrniiiiul  GUnieaUi  an  calM  lb* 
el/aetory  relU.  As  yet  im  ouiineiUiun  hftwMn  the  Mibeiillbdiml  and  iat«npt 
tbelial  iicrve-filanieiiid  hait  lioeiidtiriionitrAMr!.  Thuepithutiul  C4:ll«(if  toAt) 
in  tli^  above  figure  are  «h(>wii  crxinucTU'i]  with  the  itubcpilhelial  liitfue.  YW 
fillh  iiiTvc  siippHui  the  truau:  with  ni-ii^ury  filnmciil*.] 

Odorous  pHTtieW  pitaent  in  Uiu  laipired  air  pMting  throuch  th«  Inmr 
lineal  cliaiiihi^n  (liH\i:>e  into  th«  uppur  nasal  chnmbws,  and  lafling  i>b  ibt 
olfiiutiir)-  fpiihi-lioto  pnidiice  nnmrr  iuipuIsM  whieb, ascending  to  Ihc  brain, 
give  ri'c  In  nctiwilicnis  of  son-It.  Wt-  rnuv  pn>4iime  thai  the  wnsorv  iFiipulm 
arv  ori^iiiulvd  hy  the  cuntiu't  of  tlie  nitDroiis  piirlicW  with  tb?  peiniliar  n^- 
nhaficd  iilfiielory  ot'lla  di^crihi-d  by  Max  SchiilUe ;  btit  wo  arc  ad  maeh  ill 
the  durk  about  this  mutter  as  ah  iiit  tho  development  of  risual  scoaory  im- 
]>ul*ea  in  the  roit»  and  cones  or  of  auditorv  sensory  irapuIsM  in  the  organ  of 
Corti. 

The  »tih*idTnry  appuratns  of  smell  is  exceedingly  meagre.  Br  the  (onwd 
nasal  inspi ration ,  called  siiiHing,  we  draw  air  so  fitrtibly  ihroiigh  the  nostrih 
that  ciim'tits  pans  up  into  the  upper  rh  well  as  the  lower  naaal  chamber* 
and  tbuM  a  more  complete  contact  of  the  odorous  partiotes  with  ibe  olfaoiorj 
membrane  than  that  nupplicd  by  mere  diffoBion  \t  provided  for. 

Wc  bave  ever}-  reason  lo  think  that  any  Btimulus  applied  to  the  olfactor; 


9VRI.t. 


955 


nerve  «!!!  ppMliice  t\>e  seitRHliim  of  aniell :  but  the  proof  of  this  !■  not  to 
ir  M  ill  the  caae  of  tW  ojMit-  lad  nadilurr  iictvm.  Wv  are.  hoirever,  sub- 
ject to  ■enaatioM  of  wnell  nnl  cautM^t  Uy  objei^tiTC  rxlon.  I1ie  olfaclory 
inembniiM  it  ibo  onir  part  of  tlin  bi»(y  in  which  mlon  an  iiuch  can  give  rise 
to  any  *«nntio»s:  am)  thit  iM>n!4iliiin«  to  which  t)i<-r  pve  nae  nr«  nlwajs 
ikoaf!  of  irtndl.  The  miicouti  incmhrnnc  n(  the.  niiie  i*.  howerer,  also  do 
tlDHnim«nt  for  the  (level opnif^nt  of  nflirrmt  impulxM  other  than  the  specific 
otfllclofy  ()fm^  Chrnicnl  utimiilation  orthfi  nlfni*ton'  merabrnae  by  pungeut 
subaiancca  such  it*  Bfiitniiniu  cives  riar  to  aienMition  (itnlinct  fn>in  that  of 
flnall,  iMiiHilion  which  nfrorr)*  us  no  informnii'-n  c<>nc<Tiiing  th«  ehcmical 
nalun&T  lh«  stimiilus,  and  which  is  ini)istinK>ii*hnblF  fmm  tli<-  MmutioBS 
producc«l  by  chemicnl  ^limtitniion  i>f  mhcr  pari*  "f  tli»!  muwl  inembmne  as 
well  a»of  other  Biirfacp*  enuHllyseiisiiiveloehemk-nl  sclioti.  It  is  jimhable 
Ihat  thcM  Ivn  kinds  of  sonmi'iiiB  thus  arisinc  <n  the  olfactory-  mcnibnioe 
are  conveyed  by  iliUi-n-iit  ncrvca,  IIm  former  by  the  ollnclory,  the  latier  by 
Ibe  fifth  ncr^T. 

For  the  tlevelopment  of  bouAI  it  appeflrs  necessary  lhat  the  odorou*  par- 
ticles should  be  conveyed  lo  the  uasal  merobrane  in  a  (gaseous  medium,  nr  at 
teaat  that  the  surface  of  rhe  membrane  should  not  be  exposed  nt  the  same 
lime  to  the  action  of  floids.  Tlina.  when  the  nostril  ia  filled  with  rosewaler, 
the  odor  of  roses  is  not  perceived ;  and  simply  Gllinjt  the  noetrils  with  dis- 
tilled water  suspends  fur  a  time  all  atnell,  the  sense  reluminf;  jfraduatly  after 
the  water  has  been  removed  ;  the  water  apparently  aoU  iDJuriously  on  the 
delicate  olfactory  cells. 

Kach  substance  that  we  smell  causes  a  speeiBc  Mnsatlon,  and  we  are  not 
nul^  able  to  reoo;;uize  a  miiltittide  of  distinet  odurii,  but  a]m>  to  distinguish 
individual  odora  in  a  mixed  «mel1. 

A«  in  the  previmi»  sciiitcit,  we  pn^jccl  our  Rcn«ation  inia  th«  external  wr>rM  ; 
the  Stncll  ap|ican  to  Ih.-  not  in  ikur  ikhh;,  but  Snmnwherv  outside  ux.  We  can 
Judm  of  itif  ponilion  of  the  mlur,  however,  even  lesw  definitely  that  we  ean 
of  liiat  of  a  sound. 

The  Miwatlon  laka  some  time  to  develop  after  the  contact  of  the  slimtilui 
with  tlie  olfactory  membrane,  and  may  Inst  very  long.  When  the  stimulus 
is  rrpeaicil  the  scnwilon  very  S(«>n  dies  out ;  the  sensory  termtnnl  organ* 
spM^fily  Iwcorae  exhausted.  Menta)  anraeiations  cluster  more  strongly  niunil 
sensations  of  smell  than  ruuiiil  any  other  impressioas  we  receive  from  without. 
And  rrHex  cllbct*  arc  very  frcfjiicut.  manv  people  fainting  in  coiKojucuec  of 
the  contact  of  a  few  odoniiis  paKiclcs  with  their  olfactory  cells. 

Apparently  the  Inrgrr  the  surface  the  more  intense  the  aenaation  :  animals 
with  neule  •cent  hiiving  a  proportionately  large  area  of  olfactory  monibrano. 
The  quantity  of  maleriul  re<iiiired  to  produce  an  ollnctory  senaation  may  be. 
M  in  the  case  of  mudk.  nlmivt  immeasurably  small. 

When  two  different  odors  ore  presented  to  the  two  nostrils,  an  oecillatiftO 
of  sensation  similar  to  that  spoken  of  in  binocular  vision  (p.  9^7)  takw 
place. 

The  assertion  that  the  oUiictory  nerve  is  the  nerve  of  smell  baa  besn  db- 
puled.  Cases  have  been  recorded  of  penous  who  appeared  to  have  poaseMttd 
the  sense  uf  smell,  and  yet  in  whom  the  olfactory  lobee  were  found  after 
death  to  be  abtent,  Direct  experiments  on  animals,  however,  show  that  )oa> 
uf  the  olfactory  lobea  entails  loss  of  smell.  On  the  other  hand,  it  is  stateil 
lhat  section  or  injury  of  the  fifth  nerve  causes  a  hiu  of  smell  though  the 
ol&etory  nerve  remains  intact ;  but  in  ihcee  Maes  it  has  uot  t>cen  shown  that 
the  olfactory  membrune  remains  intact,  and  it  is  <iuit«  poaaible  that,  as  in 
the  case  of  the  eye,  changes  may  uike  place  in  the  nasal  meaibrane  as  tho 
retull  of  the  injury  Ui  iliv  Uflh  nerve,  Mifiicieut  to  prevent  its  performing  its 
usual  funcliuHs. 


reabin'g,  shell,  attd  taste. 

Taste. 

[nt/swlo<ficat  AnaUnni/  of  th«  -Oiulalorif  iluoaiu  Jlemtnitt, 

The  peripheral  organs  conceniod  in  tlic  »cti»o  of  Mate  tn  locklbnl  in  Um 
mucous  Bwrnbraoe  cohering  tlKnIursum  oftlic  tongue,  tlw  ftuc«>.wft  pdau. 
kimI  uvnifl,  aod  poaeiblj'ti  portion  of  the  iippor  putt  of  the  phurynx.  Tlii< 
tncmbrane  is  analoeous  in  Mructurc  to  other  membmnea  of  it*  typv,  «x«cfl| 
OD  Ute  doreuiu  uf  tbe  tongue,  where  )t«  rtritcUiro  i*  limilar  to  that  of  tit 
integument.  At  this  position  it  cod»*i«  of  ii  eorium,  with  a  pupilhrj  and  a 
BUperiiciai  epitheUid  lat/er, 

PIC.2U. 


VnncAi.  soman  or  not  Qacvmrtu^im  fjinu-i.   iProm  Kolukck  ) 

A,  the  iMltllli  1  fi.  tbc  tumunilhis  vrati:  (i.lbac|ilIheUalcuv«1nRi  A,  llieiiorrca  u((W  |«|4Uiuil 

wiUl  «|inwilliiu  lowuil  tiM  luiftica ;  r.  tha  ■NODdaiy  inplllir.  y>. 

The  Klructurc  of  tlie  ooritim  is  nmilar  to  iJtnl  of  the  Mn,  bgl  i»  tJiinan 
mid  IcM  compact.  It  mrvea  as  a  point  of  insertiuo  of  tbe  inubcular  fibre*  of 
tbe  tongue. 

The  pojpUla  are  thicklj*  distributed  over  the  whole  donnl  surface,  bet 
more  part  tell  I  nrly  marki^d  in  the  anterior  two-thinls.  Thcr  project  M  mtnMc 
pRMUinencce,  wliich  jjive  tbe  tongue  a  rougheDed.  charactL-ristic  appearaaoa 

Plil.311. 


iTs^ 


Manei  jii(i>  SccnoK  oe  Tn>  PrxoiriMii  """i  »,     (Vmui  Kumikkk,  ■ml  nfUr  Tom  tart 

tklWMJIV.I 

J.  th«  (irrfltn  or  >  ruDdflmn  (aplllji.  imnlally  dcnudnl  M  )(•  ndUHdluo,  V ;  a,  i(<l<liaUnii.  J 
■!r<lanDrBfuiiNtfijrmiitiiniB«ri(bllHtUooit<n«Mtaln]aaUdio.uMT;  r.  Ma  i  r,  mfUImt  )«•■  •« 
iluido  |a|4lljc  In  liig  nsiKbbartaa  ■trncturaar  Uto  tDagua. 

The  |>apillni  are  of  two  Icindf,  tbo  timpU  and  eompound.  The  nimpU  paptllc 
are  aiinilar  to  tiinse  found  in  the  akin;  tliey  are  found  GCOttereil  over  the 
whole  dorsal  surface,  between  the  compound  pa{Hll».  Tbej  an  bum 
numerous  in  the  poatortor  portion  of  the  oi^an.     fne  eompound  papjllm  an 


957 


of  thiTc  vnrieli«i>;  the  pnpilln-  maximii:  or  circumvalliitje,  (be  pnpilln  modin 
or  ftiDgifonDra,  ntii)  (he  [inpillif  minintn.'  or  filifurtim. 

The  papula  rimimrfillatrr  ( Fig.  WJ  t,  which  arc  the  lnrpr»l.  »re  «btuil 
«i^hl  or  ten  in  number  ttnd  form  n  V-ehapcd  row  nt  llic  junction  of  the 
middle  and  posterior  two-thirds  of  the  tongue.  Thev  consist  of  a  central, 
bnxid  papilla,  surrounded  bjr  an  annular  rins  or  wall  of  about  the  Mmv 
deration,  and  se;>nraled  from  tbe  centre  impiMn  by  a  circular  liwiire.  The 
cCQiral  papilla,  aa  well  as  tbe  eurroundine  wall,  is  covered  b_v  siniplo  papilliw. 
Each  of  tneni  re>ceives  one  or  more  cupilTarv  loops  and  nerve-filnmeDta. 

The  papillix  funyihrmtr  (Fig.  '253)  are  found  principally  on  the  tip  and 
sides  of  the  tongue,  allhouf-h  srallered  fparwlyover  the  whole  of  the  anterior 
two  thirds.  These  are  so  named  from  ihetr  fungiform  shape,  being  espandcil 
at  llieir  free  eslreniity  and  projecting  on  a  sliori,  thick  pedicle,  Thev  artt 
vuTered  by  simple  papille,  and  contain  plexuses  of  TeaeeU  and  nerves. 


a    h    A  r       a 

4I, TWHOftl  MMlua  n««r  the  iiiltUio  uf  Uir  dnnBl  tutkciof  Owtotifao:  n.a,  ftmgtfcfm  ia)4llB: 
h,  tOXttna  fBMIbt.  with  ikrii  t>*ir  lltr  pnt-om,  <,riiiinvoBWdeprl*«d  of  umi •pUbenuD :  me- 
MBld  3  OlMftftn*;  S.  aiininn  (»id[iuudi1  |a|41lE^  a,  mittrf .  r.  vtiD;  e,  aplllu;  loofBOf  Iba 
•MOnduTiav"'*-  fr.  Un»orbueiuciil-iDCiiilirBDt-.(l,M004i>l(rTP''l>">»^<le|>ii*«dsff.(.  Iblf^ltll*- 
■an  i  /.  I)■l^llka  pmw«i  or  •(dltidtum  a*fi<tiis  Ui»  dinpls  |M[riiln,  uuwDlllal  3»  dluuctm :  f. 
M|anMdaa(iteudp«nl«k>ot«tlibotluiu,pu«fitlM3CO<lluii«Mn.  LXbatnAmndoatMiurflire 
of  UM  loiuM :  1,  m,  andii  of  bali-llk*  «|4I&«1M  procfM.  tkamlmt  *wMIn  la  lb*  iMtrtcMad 
ainDE*inent  0/ tb*  laiUeha.  bill  la  4II  •  aMt««MUB  erf  llM  pMOehi  towitd  ibapttnltXMHMSa 
KiH  hair,  roainlbed  IWi1luii«tcn~   (AflsrlVDoaDdBciwMtV.I 

The  papilla  filiforme*  (Fig,  254)  are  by  far  tbe  mctt  nnmeroua,  and  are 
found  thickly  distributed  ove^  the  entire  surface  of  tbe  anterior  two-thirds  of 
th«  tongue.    They  are  minute,  conical  in  aha[)e,  autl  generally  arranged  in 


nEAntKO,   ByBLL,    Airs  TADTB. 

bii)eniiirorin  rows,  which  are  more  or  less  panillel  wilh  the  two  ronf  of 
rapilln.'  circuDivalIa(a>.  Tlieir  free  eurface  is  covered  "ilk  »ini[ili?  impillc 
The  cjiklieUum  coverinj;  them  ia  greatly  modilied,  aad  afijinire  in  ihc  for« 
of  hnir-like  procefees.  (Fi^.  254.)  These  procetwa  Hr«  bathed  in  aiani^ 
arc  iiioval>le.  and  have  a  geiii;ral  ioclinalion  (miDtiOK  backward.  The  eiaiU 
enceof  ihfce  hair-like  pr»ret»cB  oil  the  fllilorm  papilla>  luggeetA  that  ikii 
variety  of  impillie  is  iniiumtely  cotineoted  with  the  taotile  aeasibility  of  ibt 
tongue,  a»tl  not  with  gu^lnii'^ii.  In  caroivora  and  herbivon  theDc  proonm 
are  of  a  horny  structure,  and  iterforiu  an  active  fuuctioa  in  ilio  attriiKia  nml 
preluntiioii  ol  fund.  In  man  iheir  iiipecial  functiun  appears  lhrmi((fa  ihtir 
inliniairr  (sinocciiou  with  the  tactile  aca»e,  to  Kuid^  the  tuiij^ue  in  ita  vuiaMi 
and  coiiii'Iicate')  inovetnMits. 

Thi:  uitininte  (enniiintiouii  of  the  gu»iatury  nerves  are  yet  envelvpeil  il 
olneurity.  According  ti>  Kngulmann,  the  kI<wo- pharyngeal  nervea  IcnniHCt 
in  flaek-shapcd  orgnns.  which  are  tcrim-d  tUc  gwtntnry  ttuthn  or  Intte  bndt 
(Fig.  235.)  ThcH-  hulbs  are  found  pHncipiilly  in  the  pMpillnry  stirftcvaf 
the  vrall  of  ihu  circumvallHlr  pnpillic.     They  arc  aUa  found  in  the  fuDglAni 

Flo.  3iS. 


^ 


On»iONT  Bi^lM  rsoH  iiii  l-inH*i.  UtnAToRv  Oants  or  mi  lunHr. 

pnpilla),  but  are  Icse  niimerDiiB.  They  coimiat  of  a  fla«k-ahaiie<l  fundus,  which 
r«eU  upon  the  »ubepithe]itd  li^Bue,  and  a  mouth  w  hich  opens  upon  the  sutftre 
of  the  mucous  tnemhranc.  The  mouth  ia  known  at  the  guHaiory  ftore.  Tbe 
fundus  of  the  flask  is  computed  nf  two  vnrietHS  of  cells;  the  outer  ur 
iiivetiiti^  eetU  are  fusiforDi,  nucleated,  and  eranular,  plnec*!  nnmlM  ud 
arranged  conrcntricnlly  in  a  direction  tram  Uic  haw  to  the  neck  :  iticy  Um 
form  a  wall  which  cncloees  elongated  niicleuied  ccIIh  with  filainenti<u»  jm- 
MflKx,  which  extend  through  the  gustatory  pore  and  prnjert  an  very  Kntty* 
pointed  or  truncated  extremities.  Theae  inner  cell*  are  calleil  the  gndaiaij 
tetls,  and  are  supposed  to  he  the  essential  terminal  elements  concvned  b 
gustation.  Their  relation  to  thegii-italory  nerven  has  not  as  yet  )K<en  ckarif 
demonstrated,  but  they  are  evidently  connected  with  (he  ganglionic  pIcxoM 
of  nerve-tibres  at  the  papillary  Im.-M's.  The  gusiaiory  nerves  are  nlsu  lup- 
poeed  to  tefiiiinale  in  the  epithelium  of  the  papilln.] 

The  word  taste  is  fre^nenlly  used  whcii  the  word  smell  ought  U>  be  cs- 
ployed.  We  sjieak  of  "  taiiiing"  i^ihirifvroiis  riibitiancni,  siic}i  as  an  onwi. 
wines,  etc..  when  in  reality  we  only  smell  them  as  wo  hold  them  in  iwr 
mouth;  this  is  proved  by  the  fact 'thai  the  so  cnllcd  tuetr  nf  thctv  thiap 
is  lost  when  the  nose  is  held,  or  the  nasal  membrane  rendered  inert  liys 
catairh. 

The  terminal  organs  of  tlu  wiue  of  taate  thus  more  etriotly  d«finei)  *n 


'  «n(lin((S  At  lh«  glMao-pburyn^fll  iiiid  liiigiiiil  mrvM  tn  Itie  tniico4ia  luem- 
bniMtof  tkc  tongue  and  paluli;,  iIickh;  nn\n  srrviiig  ni  tliu  ttiie^'tal  ncrva 
of  iMtC  \Vh«t)i«r  llie  Ki-callftl  gutlatory  budii  cut)  be  r«giiMi-<l  tUBjiixrlllo 
orglMof  liut«  npiican  (Inublfiil.  Thv  tiibuMiiry  njipiiniluk  u  cnntiiicd  to 
ll>i'  toiigiic  mill  li)>ii,  uliicli  by  thi'ir  movonicnin  tisrut  in  bringing  tbe  Mt|itil 

,  ■iibiiliinnw  into  nniitnct  with  l)i«  inucou)  nivmbntDe  "f  lh«  mouth. 

f  Tbougli  uc  can  hnrdly  be  mid  10  project  our  »en»atiun  of  tanic  into  the 
Cllernil  worKl,  vrc  uMign  to  It  do  »ulij«ciivc  lornlixalioD.  When  nc  piMe 
<)uiuiu)'  in  cMir  month,  llie  rrculting  •euiNitJon  of  tiiNte  givM  ns  no  intbrniiitiail 
■a  to  wlK-ro  the  (|uinin«  U,  though  wc  mtiy  Icnrn  thnt  by  oonconiitant  gcneiml 
Momtion*  aming  in  the  buccal  mucous  membrane. 

IWeVccugniic  a  niultitudr  of  diiitiuct  Instc,  which  may  be  broiullj'  claiw- 
fied  into  acid,  Mnline,  hitler,  nn<i  sweet  tniilM.  .Sii|>id  subttaiiceH  have  the 
■tower  of  producing  thwe  M-nsntions  by  virtue  "t  tlieir  chemicnl  nuture. 
but  olber  HiiHuli  will  iilso  giw  rise  to  aenifnliona  of  inste.  When  the  tongue 
»  tapped,  a  tnoie  ii>  lelt;  anil  when  a  eonatjint  current  is  piimed  through  the 
luoutb,  an  alkaline  or,  in  «onie  perwns,  a  hiltcr  metnllic  tusle  is  di:velo{>e(l 
wbcn  ih*-  an<xle,  and  ao  add  taste  when  the  kathode,  u  plnce<)  un  the  tongue. 
It  it  prohuhto  (hiit  in  theee  cases  the  terniinnl  organs  ure  iiidir*.-i-tlr  utlcc-ted 
by  the  ciirrcnl.  Whi-n  hot  or  pungent  sub:<tuncea  lire  intmdue<nl  into  the 
muulh,  scoHitioni'  of  general  feeling  nre  exciiiit,  wh)<'h  oWurc  miy  strictly 
gtuUlory  •ensatioDs  which  may  bo  prescot  at  the  siinic  lime. 

'iltough  analogy  would  leitd  ns  lo  supposv  thnt  a  siimulus  applied  to  any 
part  of  the  course  of  the  reni  gustatory  h'brcs  of  cither  the  glomt  pharyngeal 
or  lingiial  nerves  iruuld  ^ive  rite  to  a  sensiitiun  of  tiute  and  nothing  else, 
the  proof  is  not  forthcoming;  since  both  these  nerves  ore  mixed  nerves  con- 
taining other  alferent  libm  as  well  as  thi»e  of  taste. 
'  When  the  constant  current  is  used  u  a  meuiB  ot  exciting  taste,  gustatory 
aensaliuns  are  found  to  be  developed  in  the  back,  edges,  and  tip  of  the 
tongue,  the  wifi  palule,  tlie  anterior  pillur  of  the  fauces,  und  n  email  tract 
of  the  jxNilerior  part  of  the  hard  palute.  They  are  nb»eul  IWim  the  anterior 
and  middle  durval,  uud  under  aurlaoe  of  ih«  tongue,  the  front  portion  of  the 
hani  puliile,  the  [)C6terior  oiilan  of  the  fuueea,  the  gums,  anil  the  lipa. 
t^ajiid  BuliBlAUcca  are  unsuitable  as  a  test  lor  thii  purpoite,  ou  aei^ount  of  their 
rapid  itilluiiiio.  Bitter  sulMtonces  pruditce  imi^t  eflcet  when  pliiced  on  the 
back  of.  and  sweet  !<ul>dt«nce]i  when  placed  on  the  tip  of,  the  tonjfLic ;  but  the 
(■Mintf  ]x>wer  of  the  tip  of  the  tongue  variiw  very  much  in  dilft'ruiil  iudi* 
viduai.i,  and  in  iimny  Mreou  aliiiuit  entirely  HhM'nt.  It  in  mid  lluit  iicid*  nro 
best  npprtdni'il  by  the  edge  of  llie  tenguc. 

It  w  iMxniiMl  for  the  ilerelopment  ortaste  thnt  the Mihtlnnce  to  be  tasted 
should  lie  ilixnilved,  nnd  the  effect  U  Incrcnacd  hy  rHclion.  The  larger  (he 
surl'nee  (he  more  in|t-ii»c  the  Mamtlon.  The  scnsniion  lakes  some  lime  t^j 
develop,  and  endures  for  a  loog  time,  though  this  may  be  in  part  due  to  tiie 
stimulus  remaining  in  ooniaet  with  the  terminal  orgniw.  A  temperaluns  of 
about  W  is  tlic  one  nio>t  favorable  fur  the  prvduclion  of  ihe  sensntion.  At 
temperatum  much  above  or  Wlow  this,  tatte  is  much  impaired.  The  nerves 
of  taste  are,  as  we  have  t«i<l,  the  glosao- pharyngeal  and  the  lingual  or  gus- 
tatory. The  former  supplies  the  back  of  the  tongue,  and  section  of  it 
destroys  taste  in  that  regiin).  The  latter  is  dt»tribtiled  to  the  front  of  the 
tuogue,  and  section  of  it  similarly  <leprivce  the  tip  of  the  tongue  of  taale. 
There  is  no  reason  for  doubting  thot  the  gustatory  fibres  in  Ihe  gloaso- 
pharyngeal  arc  prowr  fibres  of  that  nerve :  but  it  has  been  urged  by  nuuir 
that  the  Kunlaiory  nbres  of  the  lingual  arc  derived  from  the  chorda  lympani, 
and  that  those  fihrea  of  the  lingual  which  come  from  the  tifth  are  eniployeil 
exclusively  in  the  sensotions  of  touch  and  leoliug ;  the  evidence  in  lavor  of 
this  view  M,  however,  inconcluiive. 


CHAPTER    V 


FEELISa  AND  TOUCH. 


GeXSRAL  6&N8IBir.rTY   AM>  TaCTILK   pRItCKPTtOXS. 

Wk  have  ukcn  the  foTcgalne  sense*  Bret  in  t]i«  ordsr  of  dtKiUMA « 
avcounl  of  ihcir  being  ominentlj  8[iccilic  Tho  tyn  givM  u>  onlr  vimi 
muatioDs,  ihc  cnr  odI y  auditory  scnsutione.  The  Mitntioas  lire  pruduocd  io 
each  CUM  by  H|wciJic  xtimuli  :  the  eye  is  only  ntTcctod  by  light  and  tlwaj 
only  by  sound.  Moreover,  ibc  informtitioii  they  iitTonl  us  is  c«>ii(ia«*l  totk 
extomal  world ;  they  tell  us  nothing  iibout  oiireelvt«.  Tbe  tkHoim  tjimI 
wnntions  tvhich  ariee  in  our  retiua  are  referred  by  us  not  to  tho  retina  iuelC 
but  to  some  real  or  imnginnry  objefl  in  the  world  without  (including  m  pan 
of  the  cxlernnl  world  euch  jKiritons  of  our  own  bodi«  as  are  vi.-qble  to  ow- 
tdvn).  .Sueh,  nlao,  with  diminishing  pnecisioii  is  the  iofonnalioD  gainol  iij 
boring,  taEl«,  and  smell. 

All  the  other  ailereut  nerves  of  the  body,  ronlripetal  impiiUci  along  w\dtk 
an)  able  to  aOcct  our  conscioueuesi,  are  the  means  of  conveyiog  to  us  is- 
lormatioo  concerning  ourselves.  The  aenHilione,  arising  in  them  from  tbn 
action  of  varioue  stimuli,  are  referred  by  ub  to  apprupriate  parts  of  oar 
own  body.  When  auv  l>ody  conies  in  contact  with  our  linger,  we  know  tlut 
it  is  our  liug«r  which  Iiaji  been  loucheii ;  from  tbe  resultant  seoaotinn  we  ad 
only  learu  the  existence  of  oertain  ({ualiliea  in  the  object  touched,  but  n 
also  are  led  Ui  vounect  the  oognitaaou  of  theae  <iualiUca  with  a  particular 
part  of  our  own  body. 

Like  tbe  inure  sjwi'itjc  *eii»cii  previou»1y  studic<l,  (he  Aeiuationa  of  wbid 
we  are  aav  tpeiikiu^,  and  which  may  be  referred  to  under  tlte  namt  «f 
touch,  using  tlmt  wunl  for  llie  prevent  in  a  wide  mtsuiing,  requlr*  for  thdr 
produdlou  terniinal  urpmx ;  ami  the  chief  but  not  excluttve  ornui  of  toad 
IS  to  b«  foun<l  in  the  epuli^rmin  of  the  nkiu  nud  cvrlain  underlying  Danrooi 
Structure!).  F«r  ihe  ilrvelDpmcut  of  sjn'cific  tactile  sciMttionjt  the*o  tcfsiinsl 
OlfianB  arc  a*  cwenlial  as  arc  the  t4-rniinal  orvnns  of  tbe  eye  for  sight  orrf 
the  car  for  hearing.  Cimtuct  of  the  «kiu  with  a  hard  or  with  n  hot  boJf 
gives  rwv  to  a  distinct  sensation,  wh<;rrl>y  we  rcco^isc  tbitt  <r<^  have  taucbfd 
n  bard  or  a  hot  body.  But  (be  a])plication  of  cither  body  or  uf  any  o(bn 
stimulus  to  A  ncn-c-lrunk  gives  rise  to  a  ««isatiun  uf  getural  frelin}  oalf, 
cornviiutiding  lo  the  Mniplc  sensation  uf  light  whtch  is  pro4luc6tl  by  dinci 
stiinulati<m  of  tho  optic  nerve.  Wo  have  no  more  tartilr-  prnxption  iifi 
body  which  is  in  contai't  with  a  ncrvc-lrunk  Ihan  we  could  have  i'muo/  ptf- 
CfptioH  of  any  luminous  obj<ct,  ibe  rays  proceeding  from  which  were  «Uvng 
enough  to  excite  sensory  impulses  when  directed  on  to  the  opiic  nerve  is- 
stend  of  on  to  tlie  retina,  suppusinj^  such  a  thing  to  be  pomblo.  It  is  furUwt 
ebarncteristic  of  these  ordintiry  nerves  of  general  feeling,  that  the  aeiuatiaM 
csusrd  by  any  stimulation  of  them  beyond  a  certain  degreo  devdop  thai 
slate  of  conscioueneM  which  we  are  in  tbe  habit  of  u[)eaking  of  as  "  paio.' 
Putting  a^ide  the  general  feeling  which  many  paru  of  the  eye  pnHiA,a 
very  strong  luminous  stimulation  of  the  retina  is  rei|uire<l  li>  prt>duce  > 
eenaatioQ  of  pain,  if  indeed  it  can  be  at  all  brought  about ;  wbere'ju  a  vtr; 


TACTlI.lt    SKNSATIONS. 


9rtl 


I 


I 


moderate  stiinalMMn  or  lh«  Bkio,  and  itlnxwt  every  BliniuUtioD  of  an  ordi- 
aarr  nerre-troiik,  U  said  bv  us  to  be  {xiinful. 

1* IioiikI)  iho  skin  is  the  clivef  on(Sn  of  touch,  the  mucous  membrane  lining 
ibi;  vnriuus  paBBAgeaof  lb«  b<nli|-  also  serves  ss  an  iDsLinneDl  for  (he  same 
teti»e,  but  onlv  ^rashutl  distance  frnm  the  re6|)eclive  orilices.  We  can 
re<.-<>f>nii«  harO  or  hot  bodies  with  our  lijia  «r  moulh,  but  a  hot  liijuid,  nben 
it  ba«  reaobt^I  the  o»ophaaus  or  atoinacn,  umply  sivea  rise  to  a  wn«atiou  of 
pain :  wc  i-aimot  distinguisjt  the  seou^on  caund  by  it  from  the  seasHtion 
cnutii-d  by  a  draught  of  a  luu  acid  fluid. 

Ffini  |>ar(M  aud  tiiwtiet  of  the  iKidy  other  than  the  akin  aud  tlie  portions 
of  RiucoiiK  ititimhraiie  juat  uicnliotied  wc  liave  ubacure  avuMlitina  of  Keuerol 
tircliiig.  by  which  we  are  mtuit:  vaguely  aware  of  the  geiiiTal  coiiditJim  of 
our  ImmIv,  though  our  jud^menta  in  thin  matter  are  chiefly  iuAui-nced  by  vhat 
me  aliall  have  to  vpoalt  of  directly  as  a  muiu'ular  !>ense.  In  all  |iarl«  of  the 
body,  however,  on  uct'aaioiii*  all  ton  fntfueiit,  thin  gem-ral  fcelintf  may  bccoma 
promiDCat  aj>  pain. 

Tb«  stimuli  which,  irheu  nppli<.-d  to  ihenkin,  give  riiw  to  tactile  percO]>lJott6 
are  of  two  kinds  only:  (1)  inechaDical.  that  in.  the  contact  of  bodies  exert- 
ing varying  degrees  of  prraiurv:  and  (21  thermal,  i.  c,  the  misiiig  or  lowar- 
ing  of  the  temperature  of  the  skin  by  the  anprDarh  or  conlnct  of  hot  or  coltl 
belies.  Wc  can  judge  of  (he  weight  and  of  Ihc  (emporaturo  of  a  body. 
because  i>c  can.  through  touch,  pefxeive  how  much  it  precHS  when  alJoirod 
to  reft  on  our  skin  or  hoK  hot  it  is.  But  wc  can  through  touch  derive  no 
other  nerceptiong  ond  form  no  other  judgments.  An  electric  shock  sent 
througli  ihc  «kiii  will  give  rise  to  a  scosatiDU,  but  the  sensation  is  an  iiidefi- 
Dite  one,  because  the  elcclHc  current  ads  not  on  the  terminal  organs  of 
touch,  but  on  the  fine  nerve- branches  of  the  skin.  We  cannot  distinguish 
the  sensation  so  caused  from  a  mechanical  prick  of  siniilar  ioteusitr,  wo 
OUlDut  perceive  that  the  tennatiou  Ls  caused  by  an  electric  carreot.  ^imi- 
krly  ocrtain  chemical  stil>nlanc«>,  tuch  ai>  a  strung  acid,  will  give  ri»e  to  a 
•HMUioD,  but  we  cannot  [tcnvive  the  aci<l,  nc  can  form  ui>  judgniciit  of  its 
BUUre  Aich  as  we  could  If  «e  ta.ilc<t  it;  and  if  the  add  dutv  not  twrraealo 
the  skin  tn  an  to  act  directly  and  chemically  on  the  fttni  iivrvo -ubrat.  wo 
cannot  distingiiivh  the  acid  Croni  any  other  liquid  giving  riMi  to  the  samo 
aiinplc  contact  impnwou*.  The  terminal  organs  of  (he  skin  are  sudi  •• 
are  nnly  nUbcled  by  j>rr0ure  or  by  temiMTnturc.  Conversely,  preamire  or  s 
varinliou  in  t'nipeniiuri-  brought  to  l>e«r  ou  a  nerve-trunk,  instead  of  on  (bo 
terminal  crgauo.  produce*  no  >jireific  tactile  sensations  of  pressure  or  tcm|)cr- 
ature,  but  merely  general  tensations  of  levling  rapidly  rising  into  pain. 


TaCTII.K  t^KKSATIONlt, 

Setitativtu  of  Pnttvre. 


■  As  with  visual,  so  with  tactile,  and,  indeed,  with  all  other  aensattoDS,  the 
I    intensity  of  the  Mtmilion  luaimaina  that  general  reladou  to  the  intensity  of 

■  the  etimuluB  which  ue  mike  of  at  i>.  916  as  being  fonnulaled  under  Webtr'a 
P    law.     We  ran  di.'tinguisb  the  diflerence  of  preieure  IxHneeu  one  and  t«o 

grmtamt*  as  rvadily  a*  we  can  that  between  ten  and  twenty  or  one  hundred 
and  two  hundnxl. 

Whrn  two  wnvalionx  fnlhiw  each  other  in  the  Mme  apot  at  a  tufficically 
short  interval,  (bey  arc  fumil  into  one :  ihiiK,  if  the  ItiiKer  be  brought  to  bear 
lightly  on  a  rotating  cnnl  having  a  serirs  of  holes  in  it.  ibe  botes  Mas*  to  be 
wit  a«  «uch  whi-ii  liicy  foiloa  each  other  at  a  ra|>idiiy  of  about  1600  in  a 

81 


962 


riBLiiTG  AXD  Torcn. 


sooood.  Tltc  vibrnlioiu  uf  ■  Cird  ociuw  In  bi;  a|>(in.-oiHbt«  bv  l4iucli  min 
Uief  reach  tli«  snini.-  ranHitr.  Wbcu  wiuniiMw  ure  generalpd  ■!  txiiuu  nf 
Ike  pkiii  bio  clone  t<igctni><r  Uiey  booomo  fuMd  into  one;  l>ut  Ui  tbU  (wiiu  *• 
shall  rctuni  pnwmtly. 

Tbe  mnsniion  cnusod  bv  prauun  Ja  at  its  innxiniunt  sooii  iift«r  iu  btfig* 
Ding,  fttid  tbencclorward  tfiminiibes.  11i«  mnrv  middi-iilf  tliv  pnaMira  b  W 
crcaeed,  tbc  grenler  llio  senuttion  ;  and  il'  I)k'  incrnwe  hn  sulEcieotlir  gndual, 
even  very  great  preMittv  timy  be  applied  n-ith'viit  givinc  riaa  Co  anjTMiHi' 
tiou.  A  genealioii  in  any  e|H>t  is  increased  by  contrast  WMR  Um  iiarraUB£a| 
arena  are  nut  eubjcicl  lo  prcMurc  Thus,  if  the  linger  be  dipp*-)]  inti  nut- 
cury.  the  pmsuro  will  be  felt  mo»t  at  the  turfaoe  of  the  Huid :  and  if  iIm 
finger  be  drawn  up  and  down,  the  Benaation  caused  will  be  that  of  a  riii| 
ingviug  along  the  linger. 

All  parla  of  the  akin  are  not  equally  positive  lo  preamre  ;  email  diflrr- 
encea  uf  simple  preaiure  are  more  readily  appreciated  wlien  brouf;bi  (a  bear 
on  the  jialniar  i>urfac.-v  <>{  the  finger,  or  on  tiie  tVtreheiai).  than  oo  ilip  anoot 
on  tbe  Hide  uf  the  fool.  In  makittg  ibeM  deterniinalioiu,  all  luuwular  man- 
nouti  sliould  be  avoided  in  order  tu  eliminaii;  tbe  muscular  aeaae,  of  wkieb 
wc  Mhnll  (peak  pr««iilly:  and  tbr  area  Nlimubilud  «hi>nld  be  aa  arnall  and 
tbe  anrlatx*  in  coniacl  il-  uniform  an  pi'vible.  Iu  a  nimilnr  manner,  vnall, 
conwcutivc  varinli'His  of  jirawuri:,  il>  in  wnnting  a  pulw,  are  imin:  nadily 
apprrcinUHl  W  c<:rtuin  part*  of  the  ^kia  ihan  by  ocbeni :  and  Uie  minimnm  of 
prcmnrr  whiuli  can  he  Ml  difliini  in  ilittercut  pari*.  In  all  casu,  vnristtMM 
of  prrwiirr  nrv  niorr  ciwily  ilixtingiiiithvx)  when  ihry  arp  nacocmTD  tluui  whni 
they  arc  MRiitltandouB. 

Sriifatlfint  of  Tirmparatun. 

When  the  tcmpenture  of  the  skin  i»  raised  or  lnirere<i  in  anjr  nioi.  w 
riM-cive  aeiiHatioiu  of  beat  and  cobl  respectively ;  ami  by  tbeac  MimiioM  «f 
the  tiMnperalure  of  our  own  skin,  we  fiirm  judgments  of  tlio  lcin|>onUurv  of 
b'fdicH  in  wutaet  with  it.  llotijes  of  exactly  tne  tuiine  teni|>eTmture  ai  tlit 
region  of  tbe  akiu  l»  nhicb  they  are  applied  produce  no  duoh  thrrmal  seiua- 
tionit,  thougb  ae  can,  from  tbe  very  aDsenee  of  aenMttioDs,  l<>rm  a  judgOMt 
US  to  their  temperature ;  and  good  oonductora  of  hi^t  appear  ra^ie«tinly 
butter  and  culder  than  bad  condiictoni  rattted  to  tlio  sanu)  teraperstur«. 

Wc  may  consider  tbe  tikiu  ai  having  at  any  given  time  and  in  any  ([irea 
Spot  a  normal  temperature  at  which  tlu-  wunaliou  of  temporature  is  at  tarn; 
fot  under  ordinarv  c-ircunistanceo  wc  ar*-  not  dirodly  contcious  of  thr  !*•• 
peralurc  ol'  our  skin  ;  it  t«  only  wht^n  the  normal  temperature  at  the  met  il 
raiaed  or  lowerod  that  wo  have  n  winjuitioii  of  beat  or  cold  napedinly. 
This  normal  tcra[)eraturo  may  bo  at  (he  Muao  time  dilTerenl  iu  diflVrent  tmM 
of  the  body ;  ihus,  at  a  time  when  DCJlhor  the  forehead  n'>r  the  band  art 
ainog  riso  to  any  sensation  of  t«mperaturo.  we  may,  by  pauiug  tbe  hand  to 
Aefwebead,  fro^uctHly  Iwl  the  fjrmcr  hoc  or  cold  bdcau^e  the  nirmul  (am- 
pentures  of  the  two  parts  diflor.  The  iionnal  teniporalure  iu  unr  vpat  oitf 
alao  vary  from  time  ti)  lime.  Thus,  when  iha  hand  b  placed  m  a  wars 
medium  fiir  soms  time,  the  aensation  of  wnttnih  cea4«i;  a  turn  nunnal  urn- 
peratane  it  esublisbed  with  thfl  sero  of  sen<aiiuQ  at  a  higber  lavaL  a  da|xw- 
tfOD  or  elevaiiou  of  thia  iieir  temperature  giving  rite,  howerur,  •»  It^f..: 
aensatious  of  heal  and  cold  respectively.  Thai  it  is  tlie  changei)  cm  It;,  m 
and  not  tbe  obanjjre  itself,  of  which  we  are  c»uKii)o«,  u  ahown  by  tho  (tei 
that  when  a  portion  of  tbe  skiu  i«  cooled,  by  brief  coninct  with  a  c^ild  -t:  ■  " 
ibr  liiManoe  we  are  still  conscious  of  the  xpot  being  cobl   aftitr  iW  " 


remove 
ptn^  li*-uiei]  fay  ili«  Bummmling  wanner  tlwuet, 

Tbe  (.-liaii^re  iu  leiu|>eriuurv  of  (lie  Kkin  neecaiBrT  lo  produce  k  teiMtUoD 
miM  have  a  certain  rapiililr;  uml  ih«  iiiDre  gm^ual  the  chnn^  Ui«  k 
{■itciiKC  Uie  «en»uti'>ii.  T)i«  refieiitvil  ili|i|>iiii;  of  tho  liand  iiilo  hut  n'ii(>.-r 
prwlueci  n  jircater  neitMti'ni  tliun  vrlii>ii  ihc  liimd  ir  iillowwl  k>  irinain  nil 
ihc  tini«  in  llie  wnirr,  tltougli  in  tin*  liittvr  curt!  ihe  teiii|HTitltirv  nf  (lie  'kiu 
i»  Riiwt  atTrdcd.  The  ciTccu  uf  oouLriut  urc  also  «ucd  in  titiMi  (Cimtiutu  m 
in  tbiDipof  (tremiirA. 

Wf  can  nith  Mitiii-  nceumcy  diitinguisli  varinlions  of  lcni|WratuT«.  npo- 

dally  ihiwc  lyi»eiii;urthe  ii»rmal  leinpsratiireof  tlir  ekin.    Thno  wnrntiuDi, 

in  fact,  folliivt  Wt'hiir'*  luir,  ilioueh  apmranlly  Mtieatioiu  of  slight  culd  )ir« 

mutv  virid  than  tlio«<'  of  >>liglit  nmt,  the  range  i>(  taixt  m-cunitc  KiMUtion 

<t>tuitig  to  lie  botwom  'JT '  luid  3-1''. 

The  regions  of  the  »kin  nuwl  ttcimitive  to  variations  in  t«mperutun<  nro  not 
iticHl  with  {ho*v  m<>st  '"nsilive  tovariationt  in  pnmiire.    TIiub  the  chrrks, 

vlids.  tcniptcs  nnd  lips  iirv  mora  muitivc  than  ino  hands-  The  Icael  sensi- 
tive parts  are  th«  \v^.  iind  front  iind  bni-k  of  the  trunk. 

Tm  simplest  view  which  can  be  taken  with  re;^ril  to  the  distinction  be- 
tween prcMuni  wnnlions  nml  lemnenilure  aeueatioos,  and  wliicli  is  sug- 
peted  Dir  ihe  fiicta  just  nidiliikncHt.  u  to  suppose  that  two  di^lincl  kia<U  of 
t«r'iiinal  orj^am  exist  in  the  skin,  one  »(  which  is  atlect^d  only  by  prepare, 
and  the  other  only  by  viirialious  in  teniiK-ruliire:  and  that  the  two  kiiub  of 

»|wripheni)  organs  are  ronnected  with  dilTereiil  piirla  of  the  central  sensory 
or};aii>  by  scimrate  nervelibres,  CertiiiD  pnthu1»givHl  coses  liave  been 
JnottA  fti  showing  not  only  that  tlua  is  the  case,  but  that  the  two  seta  of 
brta  pursue  diflereiit  courses  iu  the  spinal  cord,  'ilius  in  oertiiin  diseases 
or  iDturies  lo  the  brain  or  spinal  cciH,  hrpenettbcsia  as  rt^nb  tein|)ernt(ire 
has  ncen  nb*erred  unaec'>in|wtiied  \tv  an  nugmi-ntation  of  avniitiri-tieM  to 
propnire ;  and,  conwwelv,  inHtnnora  have  Ikth  wen  where  the  patient  could 
tell  when  he  w«.t  t/iucbcnl,  bill  could  not  diatingiiinh  between  hot  aiul  cot^ 
On  tho  other  iiaiid.  then-  arc  faclJf  which  «how  a  clow  dcjM'ndcJici-  heln-caa 
I  111'  -I  ii-ni  .iiiii  of  prr-.'Oiiire  and  tcin|)criiturri.  When  each  <ftiniiili(f  h  brought 
1  1  I'  1'  1  .1  vnry  liiiiiuil  urcn.tht  two  scn«ntiun«  are  frecpicnlly  confouiiji'd, 
a|>cclitlly  111  ihnce  regions  of  the  body  whom  sensalions  are  not  n<rutv.  Ho, 
alo,  II  [icnny  eoole<)  down  nearly  to  zero,  and  placed  on  the  Ihrchcad,  will 
lie  jiidgnl  t>y  most  people  to  be  ns  hoavv  or  even  heavier  thnn  two  penniee 
of  the  tt'mponttiirc  of  the  forehead  itseff;  and.  convcr«i^ly,  ti  body  warmer 
than  Uic  skin  will  often  nppear  heavier  than  a  budy  of  the  same  weight,  but 
of  the  snmv  lempcrvturo  as  the  skin.  Storvivcr.  cases  have  been  recorded 
where  a  hoi  body,  such  m  a  healcil  spoon,  was  felt,  though  the  applicctjon  of 
the  same  spoon  at  the  temponiture  of  the  body  produced  no  aeasattona,  and 
yet  the  lieatod  spiion  was  not  recogniied  M  a  tut  tiody,  but  anpeared  to  be 
simply  something  touching  the  skin.  It  may  be  argued  ibal  tneee  initancos 
■how  nothing  more  than  tbc  changes  in  the  akiu.  whatever  tbey  be,  which 
riv«  ria*  (o  sensations  of  pmsuiv,  are  modified  by  the  temperature  of  the 
Ain  for  the  linie  l)eiiig.  whereby  the  judgment  as  lu  the  prewure  which  is 
lieiog  eiertc<I  is  rendered  faulty  ;  hul  ihey  may  also  be  taken  to  indicate 
thai  variations  in  pressure  and  tcmfteratiire  nfiect  the  same  leriniiisl  orgaw, 
and  the  same  nurvc-Ubrcs,  though  slTi-clin;;  them  iu  a  ilifTfreni  wav.  and 
generatiui;  ucrvoits  impulMM  so  far  different  ihat  they  give  rise  to  di^erant 
•eiMUiuus.  And  we  may  hert-  note  ihnt  <re  certainly  cannot  speak  of  nerves 
of  warmth  in  the  same  seiL:r«  iu  which  we  sneak  of  nerves  of  sight  or  of 
iag.  A  «*.imulus  (of  whatever  kind)  applied  to  an  optic  or  auditory* 
t.  If  a<lu>|iinta,  give:i  rise,  lu  we  have  seen,  to  a  scuiuition  of  li^ht  or  of 


FEELIN'O    ASD   TOOCH. 

wund :  ft  Blimulus,  oii  tlio  oiher  hniiil,  npgilinl  ut  th«  trunk  of  *  cuUmoui 
iwrvp,  ipvee  riw  oiilv  to  gcnrnil  livliiig  i>r  pain  ;  tltmigh  ihr  nerro  etruiiilf 
cunuins  tibres  by  uliich  ^cnnitions  of  pnwtirv  imil  of  lc»)|>rraitini  nwli  iw 
brsio,  the  general  feeling  which  i-timulniion  of  tlxi  trunk  causw  u  akin 
n«itli«r  to  aensntioDs  of  pnrssiiro  nor  to  tboae  uf  warmth. 

The  nipidily  with  which  hot  or  col<l  bodiis  brought  into  c'ootact  villi  tW 
skin  Kive  riite  lo  Mosnlions  of  tt^nipcmture,  Higgesia  (Iml  the  terniinnl  ■{>pi' 
raiUB  fur  ^neraliiii,'  thetie  ^onNition^,  irhnb-Ter  h«  ita  nauirv,  is  pliioed  iii  the 
epi([«rmiH.  Mid  indeed  as  iiettr  ns  powibic  to  the  siirfnoo.  I'nvure,  on  iht 
other  hand,  (.-ud  be  rendily  trna^iiiilled  through  even  a  thick  layer  of  ikk. 
And  thoite  who  nmiiilniu  the  esistenoe  of  different  lenuiual  oiKUU  tat  pirn- 
Bureaod  le[n{>er&tu  re,  regard  ihe  uerreendiof^  in  the  epidermic  a^  the  Utirr, 
and  the  eorpu»cula  tacltid,  en<l't>u IIm,  and  allied  ortpuutte  the  foru>er.  Bwt 
tiw  evidence  we  poaaew  concerning  thia  loatler  is  at  protcnt  iuooncluiive. 


TAcrn.B  Perckptioks  asd  JuixiiiRiiTS. 

When  a  body  pruMM  on  any  part  of  our  skin,  or  when  th«  t«oiporatiu<i  oT 
tbo  skill  at  that  spot  is  raiMxi,  wu  uro  not  nuly  codmIous  of  prtvuiv  «  rf 
beat,  bill  perceive  that  a  purtii^ular  part  of  mir  body  hn«  b«eo  touched  nr 
htatcd.  W«  refer  the  lU'nuaiiniii*  to  their  nhuK  of  uri^iii,  uod  we  thia  tw 
touch  perceive  ihe  rtlalionn  to  mireelve*  of  tlic  hodv  whifh  ^Ivn  rise  tn  tlw 
tactile  #eii«alions,  iti  the  ^nmc  way  m»  io  our  vi«ual  |>er4<eplion  of  extMnal 
objei'ts  wc  refer  Ki  exleni.il  niidire  ihcienwlioiu  origiiuitiue  in  certain  parti 
of  the  retina.  Wheu  wc  nre  touched  on  the  finger  and  on  llie  l>itck  wc  nlrf 
the  sensations  to  the  tiuger  and  to  the  back  respectively,  and  when  wt  ai* 
touched  ut  two  platen  on  the  tuime  liuger  at  th«  same  time  we  r«fer  thea^^ 
aationa  to  two  iiiiin<»  of  Ibe  finijer.  In  thii;  way  we  caii  localise  our  >'^^fl 
tions,  and  are  tnus  assisted  in  perceiviu;;  iJie  epaco  relations  of  objects  inlf 
which  we  come  in  euntacl.  " 

This  l>f>wer  of  localiuuK  prendre  sensations  varies  in  diSkreat  paiu  uf  th* 
body.  The  following  table,  Jkini  Weber,  gives  the  distaiicv  at  which  in 
points  of  H  pairof  conipa.ises  nmsl  be  held  apart,  so  that  when  the  twopotnti 
arc  in  contjict  with  the  »kin  ihe  two  consequent  seiisationa  can  tie  local ivd 
with  sufficient  accuracy  lo  be  referrtKl  to  two  points  of  the  liody,  and  not  eos- 
foiuxhil  tog«lher  as  one: 

Tit)  uf  tongue I.I  aiin. 

Piliu  of  last  phalanx  of  finger S.2  ** 

Palm  nf  iocond    "             " 4A  " 

Tip  of  Hon- fl.6  '• 

White  psrt  of  Hiw 8.S  "* 

Bsck  or  seeoiid  pliHlniix  uf  finger 11.1  " 

Skin  over  malar  hone 16.4  " 

Rw-fc  of  hand 29.8  " 

l''orcnnu S9.8  " 

^teniuin 44.0  " 

lUck «6.0  - 

And  an  analogous  di«tribuiion  has  b«en  observed  in  reference  to  the  toosli- 
lation  of  MDsatiutis  of  leniiieTatu rr.  As  a  general  nilr.  it  may  bo  said  thai 
the  more  mobile  purts  are  ihiwe  by  which  wccan  ihu*  discriuiinato  semUioa 
roost  readily.  Tbe  lijghter  the  prcasure  used  to  give  rise  to  the  eefuatiow 
tlie  niore  easily  are  two  sensations  distinguished :  thus  two  points  whiob,  wbn 
touobing  the  »kin  lightly,  appear  as  two,  may,  wlwn  tinnly  proetod,  giveriis 
to  one  ^eniation  only.    Tho  distinction  between  the soiiM^utis  is  obscured  by 


TACTI1.K  PBBCKPTIOX8   AN'D  JTTDOMCJfTS.  085 

llii'riiii!  Mnwttion;  tiri«in^  Kt  the  i>anii>  time.    Ttiii.i.  two  |iiiiiitA  iir(i(i);hl 

tr  wi(hiti  a  ring  of  hifAvj  mnlitl  prcMMnv  on  Utc  »kiii,  Hn:  niailUy  cm- 

ftined  into  one.     And  il  noc^l  Iiimlly  be  wij  tlint  ihe»c  litctile  pcrocptinn*. 

I  like  nil  olhcr  pcrcoplmiia.  bto  imoicniwlv  incrcw«()  bj-  «svreMc. 

I      Our  "  lipid  of  loucb,"  if  n-c  may  be  nUowciI  lh«  nxprvnainn,  i»  coinpowd  ftf 

tactile  KrcDis  or  iinilA.  in  the  wlqic  vmy  thnl  viir  fio.M  of  vUion  is  )Xinipi.i«CK]  of 

viviinl  arras  or  unil?.     The  tactile  tcnxntinti  ic,  like  the  vtsiitil  MnmltoR,  • 

^^mbol  to  m  of  eoiue  esteninl  «vcitl.  nnd  w<-  r^'frr  tin?  •■.■nMtiun  to  i(e  nppro* 

priate  place  to  tbe  lield  of  touch.     All  thtii  hw  Ix^-n  mid  (n.  tilT)  conwrn- 

L  iDf;  the  subjective  nature  of  tbe  limits  of  visiinl  Hreas,  uiipliM  cijtially  n-oll, 

I  nuMu  miil-iH'liti,  to  laclilo  nreiu.     When  Iwo  points  ot  Ih«  cotnpnawA  are 

C  firll  as  two  di-lJoot  iteni'nlioiis,  it  \s  not  noocveary  tbnt  rwi,  and  only  two, 

I  Berre-iibreialiould  beatiiuulHlod  ;  all  thnl  is  necessary  is  I  hit  tliH  two  cerebral 

Ltensnli oil-areas  ftliould  Dot  be  ton  coniplot4.dy  fii*«d  ^l'.;l?llle^     The  iniprorc- 

r  Bieni  by  exercise  of  the  seote  of  touch  umet  he  explniiied  not  by  tin  increaaeil 

development  of  tbe  t«riutiuil  organs.  Dot  by  a  h'f>'Wth  of  iicw  nerve-flbrea  iD 

the  skiD,  but  hj  a  Diare  exact  limilalioD  of  the  ««Dsatii>nal  areas  in  the  braiii, 

by  the  develnpuient  of  a  reustauce  which  limita  thi:  mdiation  lakio;;  place 

from  tbe  wntreti  •>(  the  several  areas. 

Uj  a  multitudt?  of  siniulliincuua  uod  cuDscciiIive  tactile  seoanUoiis  tbua 
coDverieil  into  perccptiiinn  ne  an--  able  to  make  ouraelvee  aoi|uaiDt«d  with 
the  form  of  external  objocu.  We  <mn  I«l]  by  varialiun«  of  pretmire  whether 
I  a  lurfavc  m  rou^h  or  )>ni<iiith,  plane  >ir  curved,  what  variations  of  surface  a 
i  body  preaeiits,  ami  how  far  it  is  heavy  or  li^lit;  and  fmrn  tbe  iDformation 
thus  gained  we  build  up  judt^menls  a»  to  the  form  and  nature  of  obiccta, 
judgments,  however,  which  arc  idohC  iiitimatt-Iy  bound  up  with  viaual  judg- 
ments, the  knowledge  deriveit  by  one  aensc  oonecling  nnd  completing  tbil 
obtuin<;>l  by  tlie  other.  As  to  other  seDB«»,  so  in  this,  oiirnnntions  may 
mi!*l«ul  us  and  cause  us  to  form  erroneous  jiidf^i-nt»~  This  is  well  illns- 
tnitc<l  br  the  so-called  experiment  of  Aristotle.  It  !s  impciwible  in  an  ordi- 
Dary  poMtion  of  the  Kn^rs  to  bring  the  radial  side  of  the  middle  tin^-er  and 
the  alnar  side  of  the  ring  finger  to  bear  at  the  same  time  on  ■  small  object, 
eucli  oa  a  marble.  Heooe,  when  with  the  eyes  shut  wo  cross  one  fiager  over 
the  otiier,  and  place  a  marble  between  tliem  so  thai  it  touehea  the  radial  side 
of  the  ooe  and  the  uloar  side  of  the  other,  we  recogniie  that  the  object  is 
euch  as  could  not  under  ordinary  conditions  be  louohe<l  at  the  Nime  lime  by 
ihete  two  portions  of  our  skin,  and  therefore  jud^e  thai  we  are  Uiuebing  not 
one  but  two  marblesi  T.'|ioii  repetitiou,  however,  we  are  able  to  ourreoi  <Hir 
judgment,  ainl  the  illusion  dlaap|>eaia. 

Distinct  tactile  sensations  are,  as  we  have  seen,  prodnocd  only  when  a 
stiiuuliis  is  applied  to  a  terminal  orj^n.  When  seusatioiu  or  affections  of 
general  seitsibility  other  tliau  tbe  dntinct  tactile  sensntions  are  developed  in 
the  terminatHHi  of  a  nerve,  we  are  sdll  ablei,  though  with  leu  exairtiiu>b<,  to 
refer  tbe  sensation  to  a  |>articular  |)«n  of  the  Ixxly.  Tlius,  when  we  are 
jirieket]  or  burneil,  we  can  feel  whrre  tbi;  prtek  or  burn  i*.  When  a  sensory 
iicrve-triink  'a  alimulateil,  tb<-  weDKiilion  L>  alwuyx  rvfi-rreil  tit  iIk'  [Kriphenil 
teriuiuati'in-A  of  ihii  nerve.  Thii.-i  a  blon-  on  tin-  ulnar  nerve  ill  thi'  cltiuw  is 
felt  ns  a  tingling  in  thv  little  and  riit^  finjfun  eorrc^jrinding  l<>  ihr  •liatrilHi- 
tion  of  thci  ncrvi-,  nnil  lu'ii^ntioni'  *Uirliil  in  Ihe  slump  nf  an  ■T»piiliiti.--1  limb 
aro  rofbrmi  to  Ibv  alx<«Dt  ntombcr.  When  o<ild  i*  apprivol  t»  toe  ulliovr  it  m 
felt  as  cold  in  the  skin  of  the  elbow;  but  a  cmling  of  ihv  ulnar  nerve  at  this 
spot,  •incc  stimulation  of  a  ucrve-tnink  girca  rise  to  general  Moaations  only, 
(imply  gives  rise  to  juiin  which  is  referred  to  the  ulnar  tide  of  tlw  liaod 
ana  arm. 


■ 


see 


PKKLIXG   JiS'U   TOCCII. 


Wln-ii  we  ooine  into  citiitaci  with  eslernal  bodiee  we  are  eoDsiioui  M 
only  111*  il>e  ]>reMui«  exerteii  bv  tlie  objett  oa  our  skin,  l>iil  alsr.  of  tbf  iii»- 
sure  vh'ich  we  exert  on  ilie  object.  11  we  \t\nce  ihc  liiiiul  ami  iirui  flal  <«  % 
table,  we  eau  itiliniiile  the  prtwure  cxerteil  by  liudii?  n^tiii):  mi  llie  |<almW 
die  ban^,  Btid  i>u  vamt  Uia  evnoliuiuD  a*  tu  their  neiKblJ*;  in  ibia  men 
are  cmiiciouH  only  of  tho  pn>Mtm!  «xerte«l  by  the  body  on  our  ikin-  I( 
however,  wo  hold  itie  bmly  iti  llie  hiiail.  wo  not  only  ^0  the  pnwaiire  «f  th 
bu()y,  bill  we  iire  alw)  aware  of  the  mii«mlar  (.•simiun  n^juiml  to  nfpm 
and  lift  it.  We  jHuaew  a  miiRciilar  m-dm-;  mkI  wu  linil  by  cxpmeoc*  tbM 
when  wc  tni«t  to  ihlt  inuK'iilur  tiaifV-  lu  w«ll  a*  to  ttnwiiiinn  of  [inwu)^ 
ire  CUD  furni  much  niori' tuxiunite  juilgniciila  conocrainv  the  wviglit  ofbtxlis 
limn  when  wc  r«ily  on  iu.'iiMilioni>  of  prmtiirc  ulone.  \Vben  we  want  to  idl 
how  hcKvy  II  biiily  >*,  wc  nrr  not  in  the  hnbit  «■'  allowing  it  nimi'lv  to  gim 
on  the  hunil  ljii<l  tliil  nn  n  Inlilc  :  wc  holt]  it  in  our  Itanil  mn<l  lilt  tt  i][i  ami 
down.  Wc  Bjiiiciil  to  our  nuiM^iilnr  m-ii#c  to  inform  tn  of  tin- nmoiini  ot 
exertion  ii(-i->-t«iiry  lo  move  it,  and  )>y  help  of  that,  jutigs  of  ita  wvi^ 
Aod  in  all  the  inovcincntti  of  our  body  we  are  enidcti,  even  lo  an  ulonatt- 
ing  dtffW  of  nci-iiriicy.  mn  i«  well  fecn  in  iIk-  diectiKiioni!  conirrniing  visitjo. 
by  an  spprcciiitiiin,  more  or  len  dietinclly  <ron»ejoiu,  of  the  amount  ol'  ilit 
contmclion  tu  which  wc  arc  pntliiig  our  Hiuscles.  In  autnc  wny  or  other  «t 
are  made  nwiirc  of  nhnt  [larliciilar  muscle*  or  groups  of  miifclcs  are  hein; 
thrown  into  nclioo,  and  to  what  cxIcDt  that  action  i»  being  curried.  We  air 
aba  conseioup  of  the  rurying  cunditinn  of  our  inuscln,  even  when  ihef  an 
al  reel;  the  tired  and  especially  the  paralyzed  limb  is  said  to  "  feel  "  heavy, 
lu  iliia  way  the  stale  of  our  uiuHcle.i  largely  determines  our  gcDeml  fMliu| 
of  heultli  and  vi^r,  nf  wcariniM*,  ill  healtlt  atnl  feeblcoeaa. 

It  ha«  beiii  tugKio^d  that  «ince  iniuele  iiuMeMU  little  or  no  genrrvl  m- 
tihility,  compamtrvely  little  [lain  ttuing  fell  fur  imilai>ce  when  inunoloait 
col,  oiir  miiiK-ular  >eU)io  i»  eJiietly  denvtsl  fWiui  the  traetioQ  of  the  e<U>traei- 
ing  mii»('le  "U  it»  attachmeDln;  und  nDiliiiihlinlly  ui  many  iiMianc^  of  rrwi^ 
the  ]wiin  ii>  ehii-flv  fell  at  thu  joiiik*;  and,  an  we  know.  Pacinian  bodita  in 
aIniiidiiiiC  aroiiiid  the.  joiiilx.  Atrerrnt  nerve«,  honcver,  having  a  diderent  i!i>- 
pontion  fri'iii  llie  cmlinnry  motor  ncrvei'  which  li-nniimle  in  eiid-plalea,  htn 
been  deocribiil  n»  jircneiiT  iu  nitiwli-;  and  annlogy  wixild  lend  un  lo  euppMf 
that  tliew  nifcrctil  (il>rt».  though  [HJMCMing  a  low  niDOral  sODMbility.  bi^ 
l>e  eiiPilr  exeit<rd  in  a  vpceilic  miiniier  by  a  inuaciiTar  contracliMi ;  bat  ^ll^ 
Uier  invtatigmtionH  are  nec^wary  Itoforu  tJinc  can  (m  Hccofttod  as  tbe  tnt 
IKrvea  of  tbo  mu«cular  >ensc. 

In  faror  of  the  view  thai  the  niii>ciilar  khmc  it  {icriphcral  and  &■>(  ivoinl 
ia  origio,  may  be  urged  the  fact  that  the  m-um  is  felt  when  the  muscle*  an 
tbrown  into  contraction  by  direct  galvanic  stimulalMHi  instead  uf  by  tbi 
air«noy  of  the  will.  Slany  autliors,  even  vhile  admittioc  tite  exiateDoe  uf  • 
muiicular  wD^e  of  iicripbcral  origin,  contend  that  we  also  noaseas  uid  an 
very  lar|;ely  guided  in  our  luorenieDta  by  what  aiif^bt  be  culled  a  "  neunt' 
aenite  of  <7eutnd  origin.  Thai  U  to  say,  the  ohan|[e0  in  the  central  nervMI 
■yMeiu  involved  in  iuiiiaiiiiK  and  carrying  out  a  movement  of  tW  lajdy, « 
aflect  our  ei>iiKriousriewi,  thai  we  have  a  scnite  of  the  elliirl  ilcelf. 

Il  ha«  been  olieervetl  that  when  the  pueierior  mote  are  divideil.  inoveowMI 
lieeonie  lees  orderly,  nb  if  Ihey  lacked  the  guidajioe  of  a  muscular  wnm; 
aud  all)ic>iit;h  tlie  imjutirnii-nl  uf  tbe  muveiitenls  may  he  due  in  [utrt  tu  ibn 
coiuciilcnl  luni  of  [aclile  ieiiMitionn,  it  U  [ir<ibahlc  that  it  ts  incrvitMi)  by  lli* 
Ion  of  tbo  muscular  seme.    There  it  a  malady  or  rntlier  a  condition  atieii>r 


THE    Mf3CUl.AR    SENSE.  907 

JDg  vsrious  dUeased  states  of  the  central  nervous  system  called  locomotor 
fttaxia,  the  chaiacterletic  feature  of  nhith  is  Ibat,  though  there  is  no  loss  of 
direct  poorer  over  the  muscles,  the  various  bodily  movemeDts  are  effected 
imperfectly  and  with  difficulty,  from  waat  of  proper  coordination.  In  euch 
diaeasee  the  pathological  mischief  is  frequently  found  in  the  posterior  col- 
umns of  the  spinal  cord  and  the  posterior  roots  of  the  spinal  nerves,  that  is 
in  distinctly  afferent  structures ;  and  the  phenomena  seem  in  certain  cases  at 
least  to  be  due  to  inefficient  coordination  caused  by  the  loss  both  of  the 
muscular  sense  and  of  ordinary  tactile  sensations.  The  patients  walk  with 
difficulty,  because  thcv  have  imperfect  sensations  both  of  the  condition  of 
their  muscles  and  of  the  contact  of  their  feet  with  the  ground.  In  many 
of  their  movements  they  have  to  depend  largely  on  visual  sensations ;  hence 
vfaen  their  eyes  are  shut,  they  become  singularly  helpless.  In  other  cases 
again  ataxia  may  be  present  without  any  impairment  of  touch;  but  a  dis- 
cussion of  the  varied  phenomena  of  this  class  of  maladies  cannot  be  entered 
into  here. 


CUjVPTEK  VI. 

SPECIAL  MUHCULAR  MECHANISMS. 

TiiK  Voice. 
^Thr  Phi/fiotogieal  Aii'itoviy  of  the  Laryiu. 

TnR  larynx  ig  a  iiiumbniuo-cartilaKtnouB  chamber,  broader  kbov«  tku 
below,  mid  nluaiiil  iti  tlio  ■iiti.'nor  ineriiau  porlioit  nf  the  nevk.  It  coMiai 
of  ft  number  of  carciUgM.  irhich  are  articufaied  with  each  other,  ooniMMed 
bf  ligameiita,  morcd  by  k  nutabcr  Df  i»iuclc«,  aikI  lined  by  a  mueoui  mtm 
braoe. 

The  principal  cartilagee  arc  the  thyroid,  cricoid,  the  twn  irjrteoojd.  u»i 
tli«  epiglottis. 


-     ■> 


^.>a*.«« 


V==" 


UlDUs  ADTnoK  i»  Muimi.  NwK.  I'liinrHx.  ami  Immytx. 
«,  Mpmn  at  nait.  titlCHt  It.  trcLlou  nf  hu4  |i«]«le :  b.  loDfue:  t.  ■gMlos  ot  v«(iin  inOHM 
t«l>U:  4.<Upi;  H.  utuU:  r.  ■lurrloi  irrh  »r  )4Um  ef  fanvs .  i.  loocrlor  anb,  t  btfill.r. 
phatyax:  A.b)raUbaiu;  t,  Ih^miil  ivitillkt*  :  n.  artoold  mf1lln«i>i  <.f|Mii1oiiki .  r,  clutUt;  Kr*^ 
rior  oianlni  or  Ihc  nan*^  I,  Mliiuru  fnuuXiB  l  {.  mfcttia  nfeniBf  04  Ufyni ;  V  fMMff  Ml 
<Moptal(tIII  (iMMlbofriKhl  Eiutantiiaa  tobn. 

The  thyroid  cartilaij^  U  the  larf{«tt  niid  coosIMs  of  lirn  ((UMlrilaUril 
nlnlee  of  nl»,  which  are  <M>ntiiinoui  with  '-iich  other  in  front,  where  thtf 
jonn  ilie  i>rv<iniiiencc  calk-il  thi-  iK>iiiiini  Adaiiii.  Tbo  poeteriur  hordenaT 
tbe  tliyruid  cartilaKe  aerve  n.->  n  pmiii  of  nl.tndiiaeat  of  tlia  stylo  ptuirynffMU 
aod  pclato-pliaryni^ui)  niuKcIn.  Tlic  uppnr  purl  of  nich  of  tbeM  ^raM 
leriniiiala  m  n  superior  oonii),  which  articulat«s  ititb  the  Uymd  haite ;  U* 


» 


sr  portion  MrrDioAt**  in  thi-  iiifeHor  cornu,  which  artioutaua  trilh  the 
criooJd  cartil*g«.  The  uii]H'r  Imnlcr  bcLwecn  tlio  cornuK  is  oonnected  with 
tlM  hvoMt  buu«  ]>y  thu  idyro-lijoi*!  membninu.  The  Inwer  border  ia  coD- 
DMted  with  the  L-ricuid  cartilugv  by  the  ibyro-CTionid  inoinbrmne  at  the 
nediui  line,  aixl  at  the  hiIcm  hv  thn  orio-thyniid  niutoltfx. 

The  cricoid  cartilagi-  is  Mtiint«d  bcbit  the  thyroid  i-nrtilug«  with  it«  brood 
jKiriiou  iKMeriurly.  Al  the  ii[i|)cr  pnrt  of  its  broud  portion  atv  two  Moooth 
nirfaves  on  which  the  or/tciiDid  cartilngw  lutiouluic. 


na-W. 


riij.  a«- 


FUI.  SO. 


Pml aw.— Vint  or  nil  Liiivsi  jum  rikt  <»  tii>  T«*ciiki  nmn  BniiM'  hitii  ««  Miua,n 
ft,  Ik*  hatf  of  (he  lijxilit  b«m :  r,  •f(tk*tt> ;  i,  ihc  laUttur  bofden  of  tte  ihn"ld  a^i- 
»:  «,  tlie BtdMB  hdt« of  Uw  orKoM :  a,app«r  |aut  nr  ifa*  arrtviKdilr  ■.  iilitml  ui  oiMorUn 
•UlqM  hvieUIl  uT  lbs  vjtUuM  ouuela;  b,  Utl  poMac  oitetMiyUDold  idumIc:  t<id>  of  IbO  tn- 
«g|u(M(  canlUglBiAit  rln^  of  Ui«  Inobm  i  I.  Hbroiu  mcntnitc  craBlnc  tlie  lack  oT  Ibe  ttuchta ; 
a,  nwoulu  nn*  cxpool  ■■  ■  |iut.    (FMu  Quoi^  .Iwiuiiir.) 

riD.  JH^ViBw  OT  TiiK  LiatT'i  nooi  uen.  l.apnfura  at  rtrtUt:  l  afrtmotil  nraingM:  t, 
VMkI  oonli ;  I.  pnatHlnr  rTtA>«r7<0nnH  iDiBpln :  S.  laHnl  fdeOMHixM  moiclQ  <f  IlCtil  iMc.  thM 
«(  Islt  aMe  rniunicU .  4.  •lyli-notd  niucla :  t,  thjTixryMttoJil  mliaala  of  lolt  dila.  Ui*l  of  Hehl  (Ido 
nnwTfdi  *.  Uiyn*dr*»llJtKD:  *.  vntuiiltanibitrviU.  inMcnarcrlaHUTUiwilil  llgMnML  WllhUw 
cin>|ium  of  ilM  arxUcnb]  dukI*,  Uili  dtiBnm  U  ■  (»|7  fRiin  Mt.  WlUU'*  Ocni*- 

Pw.  nft,— View  ur  ttu  mm*  lunr  or  tbi  I^uitsx  a  toM  by  hum  nr  rai  LkBTKoaKora 
mwiKi'  TUK  t'TnB4H(««r  i  Orati  Xotk     <.PidsiauU:  <.  Uio  carlllicTC  of  8Hib>rltil|  a,ftfj1*- 

The  mrYlLiiiHcl  nrlilngn  xre  pvnmiidnl  in  form  and  orticulnta  on  the 
upper  siiriiicp  of  the  criwid.  Eac^  cartilage  ha«  ao  external,  posterior,  aad 
intenml  (nmliai))  tturliioe,  an  apox  and  a  biMo.  The  apex  Js  pointe<l  baclt- 
WBr<l  and  inwnrd,  and  it  siirmudDtod  hy  a  fniall  cartilaeiaoua  tutiercle, 
vailed  the  carlilnRe  uf  SanU>rini  ( Fi)^. 'J59).  The  b«se,  which  arti<Tulatee 
with  the  cricoid  cartJIaKe,  presents  at  iu  external  iiiternul  aD^le  a  projectioD 
calk-d  the  firoe*u*u  iwu/u.  Ai  the  posterior  internal  uiiu'le  ia  a  aeoaod  pro- 
jection, lailleil  tlie  froetatua  nntteitlarU, 

The  «U|N-rior  o)H.-iiiuic  of  the  larynx  is  formed  anteriorly  by  ilie  epijthMtii, 
poNteriorly  hr  iho  uptvea  of  Lite  arytenuid  i-artilavu*.  and  laterally  br  the 
■rjtooo^^wltidwu)  fohU  atretcliing  Wiween  thtsM:  puinia.     Tbv  inferior 


J 


970 


SFECTAT.  MCSCrLAH    VKCHAlCtSUb. 


ntmiing  i-orn!9i[i>inilii  tn  ihe  iiifi-rior  border  of  thp  crimid  ctirtilnR^.  Bt1««rg 
lli(*e  jMiinU  )i>  tbf  ci'.'ilii  i)t'  Ihe  UryDX.  wliicli  has  Htr«lehiiii^  ornw  ilt  «i(In 
tho  Titcnl  c<MiU.  Thu  vm-al  cofdn  ooiuut  of  two  |Mint :  the  eii|>en»r  or  faW 
t-iK-nl  ciirilit  Km  Tni:iiitiriLiii)-ligameiih»i^  biiaiU,  nhicU  exKiiil  from  the  nttA 
iii^  iingk  of  iho  thjrnjid  lu  the.  extiTiial  aurihoea  of  lb«  iin-t«n"i<l  <nni 
Ugn;  ihr  infiTiiir  ur  lrii«  vo<:nl  oonJa  (cAffrdi  iv>(vi/*j>  iiro  membratwi-hn- 
lueiKotiH  biiDdx  which  Mrddi  soron  the  cuvitv  of  tho  Inryns  fnm  tht 
rnvdin^  tinglr  i<f  ili<t  thyroii]  to  the  provwu*  tucaI«*  of  l\»  tirytttwiA  cu- 
lilagt*.  Rrtwccn  ihr  bitnlrni  nf  th<!  true  aiid  talte  vomlI  mrd*  Ui  no  eMiptinl 
oMntDjf,  th<^  rinUiflr,  whirb  Imils  to  ■  Kiianp  ruiiiiing  upK'iiril  nnil  hiiiioi 
litv  fiilwj  voail  curclo,  fidluil  lliu  *hiciJi«  tnrvti'jif.  Th«  mumti*  iDi-aihniE 
lining  IhiM  sic  coniiiiiis  t>  ^'n^il  niimtH?r  of  folliciilnr  ^ImiiU  wbiob  ^\\^f\^ucr 
n  iDueuits  wcraiioii  for  the  inir|Hwc  of  luliricjitiii)'  thr  trii«  vwnl  i-nnlv 

Between  tht-  trui.-  vocnl  rnH«  is  nil  optming  nlircU  is  callnl  the  riniit  yl«i- 
(trfiA  Th«  f(inD  of  tht  L'lotti)!  Vftrics  verr  much  tiolh  in  th«  tii.'>|iiniloi7  «»J 
exwnton'  nvU,  mid  in  tbc  act  of  nhouuIioD. 

Th«  tnusde«f  of  the  larynx  are  iliviilctl  nnatnmimllf  Jntn  the  iiitrioiic  wA 
i-xtrineic.  The  former  are  niiie  in  oumber.  fixir  of  tWin  Itcin^  in  fain 
They  are  ihe  eKential  luiiscica  cooceriieil  in  the  luovi'metitfl  of  tli«  arytraniil 
carii)a)!efi  an')  chorda  vnciilca.  Tlie  exlrioBic  nitiBcles  counccl  the  lanat 
with  adjacent  [wrtM,  and  ai-e  for  the  moat  |>arC  couoerDcd  in  tho  elevatimi 
&n<l  dei>ri?tiaiiiii  iif  the  orpiti. 

The  larynx  ih  lined  with  »  inueoiu  meiubrant-  whidi  is  Cdnliniioua  Aam 
wiUi  (bat  lining  ibe  jiharynx  aiid  mouth,  and  l>eh)w  with  that  Winat  Iht 
trachea.  Alxivo  Uie  chonia  voailtiH  it  u  lined  with  pavement  epithelim, 
excepting  at  the  lower  anterior  portion,  where  it  U  nliated;  iKiaw  tk 
chorda  voealcei  ihe  epitbebuiii  U  of  a  nliatml  (idiininnr  varieitT.  Tke 
nitUMiis  nifmbrani^  enntninti  niiniy  niticoiis  glandf.  which  i\tv  pn:Uy  ani- 
furitdy  di»tribut«i):  thvy  ua-,  hitw^rer,  very  ubuDdaul  in  the  |Mrt  of  tk« 
nM-inbmiic  lining  tho  >uti-cu1ii«  Inryngis.] 

A  blast  of  air.  driven  by  ii  mure  ur  Ims  prolongetl  expiratory  movenata^ 
ihmwa  into  vibmiions  two  elaalic  niembraues— the  fAonkt-  iwxUr*.  TbeM 
imparl  their  vihnilion§  to  the  column  of  air  above  tbem,  and  m  give  Hm  la 
the  ioimd  which  we  call  the  voice.  Since  tfae  sound  h  generated  iD  tbf 
vocal  cords,  we  may  speak  of  them  and  of  those  parts  of  tbe  larynx  wharh 
decidnlly  airect  their  condition  as  constituting  tbettoential  vocal  apparalu; 
while  tlie  chamber  above  the  vocal  cords.  comprtBinn;  the  vcnlricles  of  tb* 
larynx  with  the  false  vocal  cords,  the  pharynx  and  the  cavity  of  the  muutk. 
the  latter  var^-iiig  much  in  fnrm,couHtituteu!iiiMdiaryap^iaratusaftheiMliirt 
of  a  resonance  liibt!.  modifying  itie  uound  originating  in  the  vocal  corii. 
In  tJie  voice,  us  itt  otlier  sounds,  wu  di»tingiiith:  1,  I^udiMOi.  "nil 
dcpiuds  on  Ihe  Hlrength  of  the  expiratory  blaiiu  2.  Pilch.  Thi*  depnlt 
o«  the  kni-lh  iind  IwiMiou  of  the  vocal  oirdn.  Their  teni/lfi  nmy  Ih.'  regatdd 
as  conslani,  or  varying  only  with  age.  It  conscipirtilly  itt-trnniuca  tlw 
range  only  of  the  voice,  and  not  th<^  [lartioular  nolv  giv<-n  out  at  any  um 
time.  The  thrill  voire  of  iho  child  m  ■Iflfmiincd  by  the  nhorlniwi  of  ihr 
cords  in  infancv,  iind  lliti  vute^  of  a  wipriinri,  Icnor.  and  iMritoiM'  an  all 
dependent  i>n  the  r<«pcrtiv«  k'ligtlis  of  ihi.'ir  voeal  conU.  Thfir  ViuMail 
Ml  the  conlrnri'  variable  :  aikd  lh«  ebiof  uroblein*  conrnTlol  with  llu>  n<i9 
reler  lo  variiitioiia  in  the  Icmion  of  the  v«cal  conU.  'i.  Qiinlily.  Tib 
de(iend.->  on  tin--  numWr  and  character  of  the  uvertoiies  accoiii)tanyiiis  "»< 
Aindamcntal  notr  aiundcd.  and  is  detenuineil  by  a  variety  of  circunislj 
ch'tef  among  which  it  the  physical  c|uiility  of  lie  cord*. 
Tfae  vocal  curdjf,  atUched  in  front  to  the  thyruld  cartilage,  end  bduiiill 


971 

the  i-roTrtwi*  vocalts  <i(  thi?  arvl«n>iiil  (yipliliiges.  Hence  n  disttiirltoii  \m* 
btva  iJruwii  lietui-ni  ibi-  rium  vucsIU,  i.r.,  llie  ojwoitiK  boumkil  liilcrally  by 
tbe  viral  (.■•inU,  Mill  iW  Hniii  reapiniEnria,  or  Kfoice  oHvven  the  nnrCMi'iiil 
nrtilnm  lit-binil  thu  priK-aMi)  v«<-jil«:  thi!t«e  uaoxs,  bowevor,  are  not  I'rvo 
fro«»  objootio».     Ill  qukt  hmthiiig  (Fig.  260,  B)  the  two  ronn  togdher  % 


nu.sn. 


u 


n 


<^- 


'^ 


TUB  LAan>x  a  sax  kt  UttAH*  ot-im  Lilimiiumra  iji  innnKwi  Cuhmthim  o*  rnt  (iijoma. 
I  Pnon  Qt'ilVi  .1  nlwy.  ■<>«  C'uciihai.i 
J,  wblla  tfnflDV  a  Mib  aatr:  S.  la  quM  toi«lUii«.  Cilurla«a  dMfi  tniHntkn,  n*  (Ofn- 
q«adiii(  dlifWi— tie  Ikun* .«'.  V.  c*.  UluAmla  llio  rtauna  ia  fodtlon  of  llie  utwmU  (•rUlffO 
■aillli«fcfBorilicnini>«<>n>Uii>ii<lrtinHn»|<lnlnrt*lnlk(abi)T«Uin<«(aMlkloDt-  L  lh(  Intaof  Uw 
■Docac.  c.ilieiij>i*r  ft«[«rloI  ILe  «[•1|l^>(ll■;  t',  Uic  iDteida  OT raAlan  «f  tbe Cpltldtl'* :  P^l*n 
a(UH  aorlortM  skU  oSthe  (ilitrinx  IhIlIiiiI  Ihu  kryux  ^  u.  imtllBKln  Ifta  ar]naii>«T4(MililiaB  Rilil 
tanwdbylkcainllKgeof  WhttKtc:  «.  •*«lllniln>'v*<l  br  lb«  oaitUica t' 8a<>I«**nl ;  a.  (hn  niuiMU 
•dbuanvaold  aitltaKe:  or.  iha  iraovnal  oonli:  tii.  iW  libi  toMl  o«f<l>:  ir.  lb* UMbBft  wRk 
IB  rtot*  I  ti  Ik*  t«o  tiraiiobi  at  Uitdr  ooniionicwmviiL 

V-abii|K4l  »iMioi',  wlik'b.  rm  m«  havi*  tt-cii  (p.  449).  in  <lwj>  hif|iinilHO  is 
vri(li>ni.-(l  inlu  n  tliumlwiilal  (ifK'iiing  hy  tliv  divor^noG  of  tho  pmceant* 
vornliv  <  Pig.  360,  C).  Wlirn  a  nol«  »  uImmii  to  lio  ultcrrd.  the  rocnl  cKinls 
•re  l>T  ihtf  Kpnroximntinn  of  th»  pfoivMiis  vocal**  broii);ht  into  n  puniion 
pamllH  \a  mud  other,  and  the  whol«  Htnn  b  narrowed  (Kig.  'ifVX  A\  lif 
their  parallelism  am)  hy  ih«  nirruwDon  of  tlw  intrrrnl  beln-ren  tli«m  tlie 
cords  are  renilpn-d  moro  Miwvritihle  of  be)D|;  thrown  into  vihnilion  by  a 
moderate  blast  of  air.  The  prolilcinf  we  have  to  oomider  are.  tiret.  liy  nlial 
neana  are  the  conk  liriioght  near  i<i  each  otherordnwu  asunder  a«ocaiHiim 
demaixtf  ;  nod.  wcoudly,  by  what  lueaiis  b  tlie  tension  of  ihe  cords  made  to 
vary.  We  may  apeak  of  the«e  two  ncliong  aa  narrowing  or  widening  of  th« 
gkuia.  and  tijfhleniiii*  or  relaxation  of  the  vocal  conl*. 

JVorTOtnay  oj  Iht  ^lolli*.     The  change  of  fvru  of  the  glotti»  b  beat  itutlof 


072 


SPECIAL  Ml-SCrtAB    ItECHAKISMS. 


Alood  ichcn  it  Is  bornp  in  mind  tlint  eneli  nn-teuuid  curtila^  is,  wlien 
boriziontal  eecliun  <Fig.  2'iU),  someuliftt  of  the  form  uf  s  triMn)tle>i 
internnl  or  tudllan,  an  esl«riiat,  and  h  ]>oeteri(ir  side,  tbe  prooeeEus  ratalk 
beioj;  piaoed  in  the  anterior  Annie  al  tlie  junctioo  of  th«  meoion  wad  ezteral 
sidM.  When  the  cartilages  are  ho  placeil  tlist  the  processus  Tuoilca  »•» 
proximated  to  each  other,  and  The  internal  diirfacts  of  the  carttlsM  MU^ 
parallel,  the  ;:-lottis  in  narrowed.  Wlieu  on  the  eontrarr  the  oartilagt*  U 
wheeled  round  «!i  the  pivDtd  iil'  their  ariieulntiotts.  so  ihnt  the  pracnwu  tuoIm 
diverjiL-,  niid  the  iniemal  snrl'uccB  of  the  oartiln^  fonn  un  angle  (ritli  nA 
iHlier.  the  j-iuttJH  ia  iridened. 

There  are  Heveral  muaulea  forming  tuKethcra  group,  which  li»  bven  cmlled 
byHeule  the  itphincier  uf  the  liirynx.  Tliew  are:  1,  the(Ayrri-<trv-r/ii>7/o(finii. 
pnxweding  from  the  inner  siirfuce  of  the  llijroid  cartilagi;  iinil  Iruni  th«  arr- 
tenoid  <-pi>(hiUideiLn  liniuciit,  tiud  nwerning  rotind  thf  outvr  ridgt  of  Uw 
nrytenoid  (-jirula)j;e  of  fta  own  riide  111  Itft  iDHcrie'l  into  the  procCMUB  inasai- 
laris  of  the  aryi<muid  curtilage  of  the  other  »ide ;  '2,  the  lA^ro-nrt/lmoi'li^ 
ftcfeniM*,  piumng  from  the  rci-utnmt  angle  nf  ihx  tli^roiil  eartilni^  \o  W 
inserted  into  Un'.  outer  edge  of  the  arrteiiifid  enrlilikgc  of  the  rame  Hile ;  X 
ibe  AgronTiflrnolilriu  tntcrnuK,  puming  from  the  Miglc  of  tin-  thyroiil  at- 
tjlsgo  to  the  proi^wnus  vorali*  and  niiler  vide  of  the  arytenoid  eHTlilage ;  4,  tht 
arj|i«H0id«tM  (po'tien*),  pa««ing  t.rnnarenH-ly  from  one  iirf  tenoid  enrtilan  tu 
ODOthor.  All  thew  mujscle*,  when  they  Mci  logetlicr,  graep  round  tlio  glotdi 
and  tend  to  cIimc  it  up ;  ami  eacJi  of  them,  acting  alone,  has.  wirU  the  ex< 
caption  of  the  last-nnniiM)  (iirylcnoideiis\  the  MJue  efleet.  In  additioa  la 
Ibese.  the  cfifo-iinil^nouifiij'  tnttrijlit,  whidi  nasses  from  the  lateral  iMirder 
of  the  cricoid  Mirlds^^e  upward  and  haclcwanl  to  the  outer  aii^fle  of  Uie  tn- 
tenoid.  by  pulling  this  outer  angle  forward  throws  the  pmoewus  vecsb 
inwanl,  and  ao  aUo  narrows  the  glottis. 

l)V'jfcii(«y  of  tlu  'jloltis.  The  rrieo-ary>enoidfH*  ptwlifu,  patting  ftooi  tbi 
posterior  surface  ol'  the  cricoid  cartilage  to  tbc  Otller  angle  of  the  artrteaml 
cartilage  behind  the  nltachiuent  of  tlie  lat«m)  crico-arvleiioideuii,  pufli  bad 
thU  outer  angle,  aiwl  so  cauBiDg  the  proomus  vocalii  to  move  oatvanl 
wiik^ns  the  giottift.  The  arytmotdeu*  pottinHs,  acting  atooo,  ba*  a  tiaiUir 
vitect. 

Tightrning  oflJie  mm!  eorttt.  The  crMvjAyroi(f«>M  pulls  ihv  lliyruid  do«fr 
wanl  and  forward,  and  *<i  iiicreasai  the  diHtnnee  between  that  cartilage  and 
the  aryti'iKiidH  when  the  liittcr  are  fixed.  Suppucing,  then,  the  aryt<'D'>*Ii'w 
and  eri«)-arytcnr)idi;ii»  jioilicus  to  lis  the  arvlt-noid-i,  tlw  effijct  uf  lh«  cm- 
lracti<in  of  the  erini-thyroideo*  wnuld  1m:  to  tighten  tbc  vocal  cords. 

Sinckraitiy  of  ihr  xtmil  mrd*.  T\\\»  i»  cflbcted  by  the  nholu  sphincter  groua 
just  niciilioiicu,  but  more  i?<|M;i.-ially  by  the  thyro^nlrnoiitfi  r^lrmur  SH 
inferNiw;  throe,  acting  nlonc.  viippieong  the  arvtcnoid  i.-artilagus  to  be  fixel 
would  pull  the  thrr'tid  ciirtilngc  iipwan!  and  iiacknurd.  and  so  sfaortssi  lbs 
dtKtaiicv  between  tlic  procOMUs  vocales  and  tlini  body. 

Thui^  almost  every  movement  uf  the  larynx  i"  alTiftcd  not  by  one  musck 
only,  but  by  several,  or  ni  least  by  more  than  one,  acting  in  concert.    TW 
movcn>oiit«  which  ^vo  rife  to  the  voice  are  iirccmincntly  combined  aoilei^ 
ordiaate  moveinenta.     ^Vhen  we  reineml>er  now  a  very  slight  variatitm  h 
the  teoaon  of  the  vocal  cords  niu»l  give  rise  to  a  marked  dillbrence  in  thi 
pilcli  of  the  note  uttered,  and  yet  wliat  a  mullilude  of  fine  dtHereoces  ef 
pilch  are  at  the  command  of  a  singer  of  eren  motlcTati'  ability,  it  »i-)nn    1 
exceedingly  probable  that  the  various  muscular  combiaatioiis  reiji. 
jiroduce  tlie  posuible  variations  in  pitch  are  of  such  u  kind  thai  fn-' 
part  only,  possibly  a  few  libres  only,  of  a  particular  muscle,  may  Ix 
Contraction,  while  all  tlie  rest  of  the  muscle  renmiiu  <|Utei.     iiiKiug  m.v 


THE    VOICE. 


973 


I 


ir  t!ie  great  rnnRe  iif  jiitch  poesMBed  by  even  oommoii  voiceit.  iia 

'  ihi-  ]H«iail)lt!  vumliDtis  III'  lenuoD  nf  u'lik'h  lh«  vocal  fDriU  iti 

tbdr  nnluml  li-nglh  uri'  (-ii)iiitiU-.  it  Iibm  l>e«u  BU^igesled  that  Mine  uf  tbe  librt* 
of  thi^  thyni  nrvhriioiilrun  inliTtiu>,  wliieli,  puung  eilber  froin  tlie  tbyn>i>l  or 
from  tb>-  antctimi),  Hp|nutr  U>  end  to  lh«  vocal  coixU  iheioselvea,  wiij,  by 
fixing  |Mrti<'uUr  (initilM  nf  tbe  cords,  so  to  H|>eak,  "Mop"  tbem :  nii'd  by 
Uiu*  nrtilicially  ohorleiiiD^'  tin-  length  actually  lUrown  into  vibrntinti,  pro- 
dtico  higher  inAct  than  the  corda  iu  their  natiiml  lengtli  itrc  tiiiiablo  of 
prmlucing.  It  hiu  hwti  kIm  auggnl^Hl  that  tlie  prooMtUK  vocalm  way 
overlnp  ciwh  otiior,  and  thereby  shorten  llie  length  of  conl  urailable  for 
vibration. 

Thcw  varioiu  muRcIts  are  supplied  by  therneiiii  ner^'e,  or  rnlber  by  spinal 
■ooMSory  tibr«  running  in  the  vagiM  trunk.  The  «(i[>erior  laryngeal  is  tlie 
afl^rent  nerve  supplying  the  miicoiis  meiubnine,  but  it  aim  containf  ibe 
motor  fibres  diBlribiited  to  the  crico-thyroid  miisele;  heniv.  wfavn  ibis  nerve 
ia  divided  on  ooe  aide  tbe  oonwpondingvoad  cord  i»  mluxed  and  high  notca 
become  iiDpoaaJblek  It  n  wortJiy  uf  nutice  thai  thi«,  the  ebief  leoaor,  and 
therefiire  the  tnoM  important,  inuacle  of  the  luryns,  hiu  ii  Mpnrnlc  and  dia- 
tinct  twrvoUB  ailpply.  Acoordinj;  [<i  some  uuthors  the  nrytenoiduus  posltcua 
ftlao  receivca  its  nervous  tupply  from  this  nerve;  but  this  b  denied  by 
others. 

The  inferior  Inryngeal  or  recurrent  brandl  supplies  nil  the  other  tnutcles. 
Wtien  ibiH  nerve  ia  divided  tJie  voioe  ia  lost,  since  the  approximation  and 
paralleliam  of  the  vocal  oorda  can  no  longer  be  efleeted.  When  in  ii  living 
BDimal  both  recurrent  nerves  are  divided,  the  glutlia  ia  seen  to  becimie  im- 
mobile and  iMtrtiuUy  dilated,  the  vocal  curds  assnmin];  tbe  ponitiDn  in  wfiich 
tbey  are  fuuod  in  tbe  body  after  death,  and  which  may  be  coa«i<Ien;iI  as  the 
ooDdilton  of  iHiuilibriuni  betireen  the  dilating  and  coaMricting  niusckv. 
During  forcible  inapinUion  ibo  gloltia  puafcsi  from  thin  condition  in  the 
difvcliun  of  more  comnlete  dilation;  dnnng  forcible  cxpirution,  tbe  change 
is  one  of  constriction.  When  the  peripheral  portion  of  one  re>.-nrr«nt  nerve  is 
■timulotod,  tho  voeal  oord  of  the  tatma  sidv  !■>  approximatrd  to  the  middle 
litio:  when  both  nerves  arc  stimulated,  tho  vocal  cords  atv  brought  loj;etlier 
and  the  glottis  is  uanowci].  Though  the  nerve  is  distributed  tn  bolhdilaiiug 
and  euoslHcling  muscles,  the  latter  overcome  the  former  when  the  nerve  u 
artificially  elimolated.  In  the  complete  closure  of  the  glolli»,  iihicb  ia  so 
important  a  piiri  of  the  act  of  coughing  (p.  'tiyO).  tlie  group  of  mtiaclca 
which  we  have  spoken  of  as  constituting  a  sphincter  is  thrown  into  tonTible 
GODirsctioDS  by  tne  recurrent  Isryngenl  nerve. 

Though  fundamentally  a  voluntary  act,  the  utterance  of  a  given  note  is 
not  affected  by  tbe  direct  psasagA  of  aimple  volitional  impulses  down  to  tbe 
latynfces)  muscles.  Bo  eomplex  and  co5rdiuat«  a  movement  as  that  of  sound- 
ing even  a  simple  and  natural  note  re^nirw  a  ooordioatiug  nervous  raeolian- 
isiu  in  whidi,  oa  in  other  complex  muacuUr  actiooa.  allerent  impulses  play 
an  im{Kirtant  part.  Auditory  sensationa.  if  nut  m  important  for  uu  oocuralo 
manattenieDt  of  the  voioe  as  are  ritual  aettaationa  fur  the  tiKiveinenia  of  tho 
eye,  are  yet  of  prime  importonee.  Thin  is  recognized  wlten  we  auy  that  audi 
and  auch  a  one  wboM  power  over  bis  Isryugeul  iDUSctea  is  im|>orfcct  "  has 
no  vuT." 

A  penon  may  apeak  or  ains  in  two  kinda  uf  voioe.  In  the  one  the  sounds 
are  full  and  strong,  and  tSe  nwmanco  chamber  which  is  aupplifd  by 
the  trachea.  bn>uclii,  nod  indeed  by  the  wbol«  chMt,  is  throws  (nio 
powerful  and  piil|>»ble  vibriilioni;  banco  this  vdvo  b  spoken  of  as  tbe  ctiMt- 
voi<v.  The  i>lhvr  kind  of  voice,  called  tho  blsvtto,  in  (bin  and  ptwir,  dssls 
cbiedy  with  high  Dol4S,and  is  act  aecompanied  by  tlui  muuc  cxHi«|iicuiKis 


flT4 


SPECIAI.  Vt^SCCLAR    M'SCHAXISUS. 


viliraiioiia  of  llie  chwi.  Much  coiilrover^y  has  Uikm  place  m  to  ttwana 
miuiner  Id  which  th««e  tno  voiL-es  aro  r«|)«Gt)vely  iMudaced.  Tba  nnmflinf 
opinion  lencheH  that  in  the  chesl-voive  ibe  Tix>al  mnls  are  MinM'n'linl  iIiwIl 
iMir  HubaUuice  beinu  ihritel  inwanl  toward  llw  inealinn  lino  liy  ibi'  motnr- 
tiqo  of  the  lhvrii-aryleii<>ii]«i  i-xierui  luuaclw,  ami  Ihe  oiwning  brtnoeo  tli«n, 
Bnincliniea  ftu  Darrow  im  ii>  he  aliiiit^I  liiiemr.  exictxtii  iil»ng  ihvir  nbiilc  Irtutb. 
Ill  the  fiibettn  voice,  on  tbi^  i>th«r  ham),  tin*  vocal  iMnli)  are  Mtd  hi  br  tliit 
and  nif.mhraiKiut,  and  the  note  to  be  given  (arth  by  a  vibnitian.  tml  <•(  tb 
whoK*  Kidth  up  tli«  eunh,  a.-<  in  tbe  obait-v<^c«,  but  of  (titt  exlmtii'  nb« 
only,  till'  lateral  |>arts,  tUoujih  not  HbHuIiiUdv  at  r<i>t,  vibmling  with  a  iHif 
«iil  rhythm.  Tliuiigb  the  vi\wh  kryrix  in  tlii-  lalNi-tlM  vuicu  i>  stratcbad  In 
Ihe  nnlcro-iHMieriur  direcliun,  ami  thr  vncn]  curds  eumMpupdinjily  otoocMtl, 
the  ritna  ro(»ili»  diMs  uul  cxtt'nd  nlon^'  tbi-ir  wholi-  leugtn ;  nl  their  mMC 
jtarl  Ihi'  i'iir<l*  an  ill  oODtnt-t,  uml  indcxid,  uc-cnrding  in  ttjtne  naltion,) 
iiijjh  fal»olti>  noltw  are  pntdiK-id  by  a  i«irt  of "'  it»iif>iiii;  "  of  the  curdo. 
acnse  of  eflort  which  ai-i'onip:init«  ihr  fal>«'ltavoi<-o  iiiilicalee  that  the  d 
id  the  larynx  which  bring  it  about  arc  c-Aected  by  eonio  opc^-iftl  mu 
mnDanTrea.  m  U  n\m  titggnUxl  by  the  fact  that  iW  Mae  with  whicb  (alMla 
aulefl  can  be  utlorcd  is  readily  inrrpasod  by  pmclice.  Tlie  cbau;»  ff^im  iW 
I'ht^t  to  the  &lsetlo  voir?  is  an  abrupt  one,  nm)  the  cuiubiued  ranee  mar  W 
very  fSlenwve.  a«  in  the  i-ase  of  pcrMns  who  can  oirry  on  ii  duel.  «iigtDf 
ultt'rnatfly,  for  InelaRce.  in  a  tenor  (chest)  and  a  aoprano  (falM-llo)  voift. 

Thn  reulriolcs  of  Mor^f;ni  are  apjuircDtly  of  use  iu  K'^'ins  ^  ^'"^ 
cnrdM  iiutBcifint  room  for  Iheir  vibraiioDs,  and  |terhai«  supply  a  MtcrMiM  by 
which  the  vocal  cords  are  kept  adequately  iiioiai.  The  purpose  of  ih<  &W 
vocal  cnrd»  u  not  exactly  known.  Sume  authors  think  thM  In  tbc  fabMIs 
voice  ibcy  ai«  brought  down  into  conUuit  with,  and  tfau*  wrvc  to  stop,  lia 
I  rue  vocal  cords. 

At  the  ago  of  ginbcrly  a  rapid  development  of  the  larynx  l«kea  pUcft 
leading  to  a  chnngt-  in  the  range  of  the  voicv.  Thi.'  peculiar  handuewW 
the  voice  when  il  i»  thii»  "  brcnkinir  "  wwinn  1o  br  due  to  a  tcm|w>mry  («•■ 
grated  and  swollen  coaditinu  nf  the  mucouR  tnembranc  of  tbe  vocal  curdi 
aoconipanyinR  the  activo  growth  of  the  whole  larynx.  Tbe  cbaitE«  in  ikv 
niuvoiM  niennbrano  niiy  conic  on  quite  suddenly,  the  voice  "breaUng"  f« 
lasunoe  in  the  counv  of  a  inghL 


VowiM. 

Rvcry  aound.  or  even-  doI«  (for  all  vocal  Muiid*  irb«Q  cnocUlMvd  h 
tbcmwdvea  are  niusical  sounds),  caused  by  the  vlbriUluaa  uf  the  Toonl  ourih 
beaidca  iU  loudness  due  to  the  force  <if  the  expiratory  blajK,  uitd  it*  pitci 
duB  to  tlie  tensioD  of  tbe  cords,  has  a  ipinlitv  •>f  lU  own,  du«  to  the  ouaihn 
mm)  reUtirc  prominence  of  tlie  overtontw  winch  aoironiimny  thv  ('iiitdamMit^ 
ton«.  Some  of  thcee  fealnrea  irbiob  make  op  the  c(ualiiy  aru  inipueed  oa  lis 
DDtv  by  ttx^  naiun?  nf  the  vocal  oords,  but  ntill  mon-  urino  fritm  variowi  amb- 
ficationH  whirh  (he  relaiivc  inleuiilia*  of  thn  overtonrn  undergo  ihruiigh  th* 
reaonanci'  of  tbc  cJivity  of  the  tnouth  and  throat.  Whenever  ire  hear  m  nnu 
Munded  by  the  larynx  we  ore  able  to  n'cnj'niu<  in  it  featHRo  which  etinU* 
us  Lo  Etntv  (but  oiic  or  other  of  tbc  "  vowxl*  '  is  iH'ing  uttcrvd.  Voirel  Hiun4> 
arc  in  Aict  onlv  cxtrrmc  aun*  uf  <|uality,  •>xln-tnc  prominence  of  orttaia 
overtonn  brou^lil  about  by  thvi*liapciu*umcd  by  ihc  buc<(nl  and  pharynpaJ 
jtaaM{«8  bihI  onlicM,  a><  Hit-  vibrations  pan  through  thcin.     Kach  vowVlliw 


SPEEfir. 


970 


I 


I 


I 


lU  ii|>|troprIal«  tnd  oniiulirc  diaposition  o4'  llieee  parts.  When  i  (ee  in  Toet ) 
■0  B<>u»iic<l,  llie  Bounding-lube  of  the  upper  air-paangn  b  made  u  sfi'irt  n^ 
poft*ilile,  ili«  larvDX  w  raiued  and  the  lioa  are  retracted,  the  wliole  cavity  t<f 
the  uioutli  inkinx  on  t)i«  funu  uf  it  brood  flask  with  a  narrou  neck.  During 
the  k'^'i^K  '""  "^^  ^  ^0  '"  'i*^)  ^'''^  *hnve  of  ihe  nioiitlt  in  aituilar,  but  «ume- 
wliat  l<>tit:«r.  For  Ifae  priiduclion  ol  u  ibm  in  fuibtir)  Ibe  inoiith  ts  widely 
(>)MMi.  H>  that  the  buccal  cavity  ig  uf  ilie  (ihai)e  uf  a  fuiiii«I  willi  lite  ujm-x  at 
lfa«  phan-nx.  With  u,  tlie  buccal  caviiy  \»  iiauiu  tliink  :>liu|N.-d.  nith  die 
iiH>uth  more  rlimet)  Uuid  jii  a.  but  llie  liji».  iuxtCiad  «f  K-iu^  retnu-ied  aa  in  i 
and  e,  are  Mxiiewliat  {irotrudett,  *■>  that  the  auuniliD^-tube  tit  i>niKiU)/ed.  The 
greaiviAt  leii^rth  of  the  tube  i»  rcacheil  in  u  (i>»),  in  wbirli  the  Taryux  U 
oepreiM»l  and  the  lija  protruded  ax  much  a*  pixtnililo.  Whlln  the  two  latter 
vowel*  ara  being  utivlvd,  the  general  liirm  of  th<!  buccitl  CHvlty  Is  that  of  a 
flask  with  a  ihgrt  neck  and  a  KiniiU  u|)eiiing,  tin-  qrifiw.-  bdug  stnaller  lor  u 
than  liir  o. 

Kitcli  of  th«te  variou*  "  vowel "  furnid  <»f  the  inoutli  poaencs  a  note  of  ila 
own,  DIM)  tnwitrd  which  it  netH  a*  it  rvoonance  chnmlrar.  Thil*,  if  MVeral 
tuaiog-forks  »f  various  nllch  Ik-  behl  while  iiiiunditis  before  a  m»uth  vthtch 
fcaa  MWiatd  the  iwrticulnr  form  iiec^vary  for  •ounmng  U,  it  will  be  found 
that  tbc  nmaanoo  will  Iw  imKicnUrly  grmt  wilh  the  fork  having  the  pitch 
of  tho  bat*  ^ 'flaL  Similarfy,  ••ilier  nud  higher  nule«  will  \k  iiilciinilird  wh'.'ii 
Uw  nioiilb  if  iiinuldi'd  to  tutor  the  other  romila.  And  it  is  the  rspcrieiicc  of 
ringers  that  each  vowel  ia  Kiiiig  with  pocnliar  eau  on  a  note  having  a  pronii- 
sent  overtone  correepondiiig  to  the  tone  proper  to  (ho  mouth  when  moulded 
to  litter  the  vowel.  The  precise  nature  of  the  vowel  sounds  is,  however,  still 
diflfxited. 

Aa  the  ribiBtions  are  travelling  thron^^h  the  phBrgngMl  and  buccal  cari- 
lieB.  the  posterior  nar<«  are  closet!  bv  the  soft  palate ;  and  it  may  be  shoKD, 
by  holding  a  Uaiiie  livfrjiv  the  itoMril,  that  ui>  current  of  air  iMues  ttom  the 
nuae  wlwn  n  vowel  in  pn.i[)erly  »aid  ar  aung.  When  the  puHterior  narus  are 
no*  ollvctiialty  cliwed  the  sound  aotiutnat  a  nii^al  (ihnructer.  The  i«ine  hap* 
|ienH  wlivn  lh«  anterior  nam  are  closnl,  lu  nhiai  tb<^  niup  i>  held  bttlweun 
tbe  lingcre,  the  nnwtl  chnmlK-r  tli4-u  forming  a  cavity  of  resonance. 


OuuonmU, 

Vowels  are,  as  their  name  imiiliM.  the  only  real  vncnl  ^nuiids ;  it  is  only 
on  a  vowel  that  a  note  can  he  mkI  or  sung.  Our  speech,  however,  is  nuuH 
up  not  only  of  vowels  hiil  also  of  oonaonaDls,  i.  e,,  of  noiiiide  which  are  |»rv 
duce<l  not  by  the  vibralion»  of  the  vocal  cords  but  hy  the  expiratory  blast 
being  in  varioiiH  ways  interrupted  orotharwisatDodilicd  in  il#  courac  through 
the  ureal  and  mouth. 

The  distinction  between  the  two  b,  faovever,  not  an  abeoluM  one,  iinc«,  as 
we  have  seen,  the  characters  of  the  sereral  vowels  depend  on  the  tbrni  of  the 
itMHilb,  and  in  the  prolucttou  of  •one  consonaDts  '  B,  U,  M,  X,  etc.)  vibra- 
tioDB  of  tbe  vocal  cords  form  a  uaoenary  though  adjuvant  factor. 

CooaoDauta  have  been  dassiSed  according  to  the  place  at  whicli  the  obar- 
aoteristic  uiierru|>tioa  or  oKNliKcation  takea  place.    Thus  it  ruay  occur : 

1.  At  the  lipa,  by  tiie  lunvement  or  pmitton  of  ilie  li|»  in  reference  to  each 
other  or  to  the  teeth,  giving  rite  to  lahial  eonsouants. 

2.  At  the  te«th,  hy  the  nuivenii-iilor  poaitionof  the  fhint  mrt  of  the  tongue 
in  If  fervuei:  tn  the  leeih  or  the  hiinl  palate,  giving  rise  to  iUnlut  ooiiaonanla. 

3.  In  the  throat,  by  the  movement  or  i>aiilKMi  of  the  root  of  Uw  tnogue  iji 
reference  to  llw  aoA  [wJate  or  pharyux,  giving  rise  to  guUMrai  cottSMiauU. 


976 


SPKCIAL  UUSCl'I-AR    MKC11ANISM9 


Amooff  the  ileiilab  BffMU  nay  lie  d!xtin^uiHhe<l  Lho  rientnbi  mminoaljr « 
oiillw},  luch  Hit  T.  lh«  itibilnuu  iiiiub  lu  S,  itnil  the  lio^unl  L.  nil  dtflVritig  (a 
the  relative  pnriii»n  nf  the  tmiifiie,  tvcth,  nrnJ  jiiitnte. 

CotiMmniits  limy  hI»ii  be  rliMiiliei)  aci'Driliri^  bi  the  cbftracter  of  tlwBon- 
mcnis  wiucli   givf-   riw  In  ibi-in.      Tl]iii<  lti(:y  niiiy  be  citlirr  <^lMm  w 

1.  Exiit'i'ivt*.  In  tbcM.'  the  chiinKt«r(  nre  ^ven  to  thtr  maml  by  thv  miiUm 
utfthlUhtiicTii  i.'T  romoval  ol'thf  Rpprnpriiit*-  interriiplioti.  Tbiif.  in  uUmiu 
Uk  tuhiiil  P,  iho  lijiH  iin  firvl  rkueil.  ihnii  iin  exfiiriilorr  <-iim'nt  of  kir  ■ 
driven  iigntiii't  them,  nod  U)>on  tbcir  beiug  «iidilcnly  <>pcnp<l.  the  aouod  i 
ectKTiit<^].  Similnrly,  the  dontal  T  \t  genornk^d  by  the  eiiddcD  roionv&l  li 
(iw  tnlcrniptinn  c»iiBrd  by  the  npprosiiuatioD  if  ihc  tip  nf  th^r  tongiti;  (o  li* 
front  »!'  iho  hard  palate,  and  the  guttural  K  bv  the  «id<len  removal  of  tbt 
ititerniptioD  cau»ra  by  the  approximation  of  the  roof  of  the  tongue  to  Ihi 
soil  null)  I  p. 

The  labial  It  ilttferv  from  1*,  inasmuch  as  it  is  aceompHDied  by  vibralica 
of  the  vocal  cordg  (that  it,  a  von'el  sound  is  uttered  at  the  aaiue  time),  ui 
th«e  vibrations  (.'ontinue  after  the  removal  of  the  intemiptioD.  Hence,  B 
is  often  spoken  of  as  bein;;  uttered  with  voice  and  1'  irithout  voice:  and  D 
aiid  U  (hard)  vfilh  voice  bear  the  same  relaiioo  to  T  and  K  witliMit  ToittL 

The  emiiinwMs  conaooants  may  further  be  divided  loto— 

2.  Jv/iirfifc*.  In  these  the  souitil  is  Kciit^niled  by  a  ni»h  of  air  throa|{)i  ■ 
constriction  formeil  by  the  [lartial  closure  of  the  li|Kt,  or  by  the  miiiinvof  tHr 
toiigue  Kgiunst  the  hard  or  soft  palate,  etc.  Thun.  F  ts  sotindtil  vih«u  itc 
lipe  are  nrDught  into  partial,  ajid  not  as  in  P  and  II  into  compbtr  nppruit 
matioD,  and  a  i-iirrt'nt  of  atr  in  driven  iliri>UKb  tbi-  Darniw«)i  <>|n-i)in^.  Fit 
Uttered  without  any  accumpanyiug  vibration  of  tlie  vocal  corila.  u  r.,  willmal 
TOicCL     With  voice  it  become*  V. 

Thd  nhilant  ^>  is  formed  by  a  rii»h  of  air  post  an  olietnietioD  nuseil  bf 
the  partial  closure  of  the  tcrlh,  the  Iront  of  the  taogue  being  <lepr«na)  M 
the  same  time ;  and  S  aceoropunicd  with  vibrations  of  the  vocal  nrdi 
becomes  Z. 

In  Sh  lh<-  dor«al  surface  of  the  tongue  is  raMtA  m  as  tu  namw  tk 

Oo  between  that  organ  and  the  palate  for  a  considerable  porligu  of  iu 
■ 
Tb  is  formed  by  placing  tlie  tongue  between  the  two  partially  open  vm 

of  teeth  ;  and  the  hard  aiid  soft  Th  bear  to  each  other  tne  sanie  rtdat>aD> 
do  I'  and  11. 

L  is  produced  when  the  passage  is  closed  in  the  middle  bv  preasiu];  the  tif 
of  the  tongue  against  the  hard  palate  and  Uie  air  is  allowet)  to  escape  U  iw 
sides  of  the  tongue. 

When  the  constriction  in  an  arpirnte  b  fonned  by  the  approximalino  iif 
the  root  of  the  tongue  to  ibe  srdl  iialate.  ne  bare  the  gutturwl  CH  iw  is 
loeh)  without  voice  and  OH  (as  iu  lough)  with  voice. 

■'{.  Befjnanti  or  tiataltf.  iu  tl)e»e,  nil  nf  nliirh  must  have  ^HbratSoMrf 
the  vocal  eonli-  as  a  basin,  the  ueual  paasage  ilirouxh  ttie  mouth  is  cJtMd 
either  in  a  labial,  dental,  or  guttural,  fa^iiou  am)  tbe  peculiar  chandab 
given  lo  the  kiuwI  by  the  nasal  cbambert>  acting  na  a  reauoance  (»vilf. 
Thus  in  M,  Ibe  pustai^ce  Li  dotted  by  tlic  apjiroximatlon  of  the  li{«,  in  N,  bf 
the  appraximoiiuD  of  tbe  tongue  to  the  hnnl  palate,  and  in  NG  by  the  a^ 
pruximation  of  the  noi  of  the  tongue  to  the  *(ift  palato. 

4.  Tbe  various  forms  of  R  nre  oflru  spoken  of  as  tvfrro/ory,  tbe  characteristic 
aouml*  l>ring  caufM  by  tbe  vibration  of  eon»o  or  other  of  llie  parts  furaitnc 
a  c»ni>lricti<>n  in  ibe  vocal  paMagCi  Thus  the  Ordinary  U  is  pn-Itiivl  by 
vibrations  of  tite  jioiiit  of  the  t^wguc  elevated  against  the  hard  pnlate,  tin 


I.00OMOTOB   MROnANISHS. 


977 


rguUunil  K  by  the  vibrnlinnH  of  tli<-  uviilii  nr  other  purU  of  i1k>  wiillci  of  lh« 
pbliryns  ;  itod  id  touw  Inoguagcs  Ihvrc  Mvcms  to  be  kd  R  prvrlurvd  by  die 
ribratioDs  of  the  lipe. 

11  ie  caused  by  che  rush  of  air  tbrough  the  nidvly  open  glottin.  Whm. 
in  Boanding  n  vowel,  the  eooud  voincidoi  with  n  sudden  chftiig*^  in  th«  |iti«i- 
don  of  the  vocnt  corda  from  one  of  divergence  to  ouc  of  nppniximation,  tUc 
vovtet  id  |m>nouiiced  with  the  gpirilu*  'ujier.  WbiMi  the  vucnl  oonia  kit 
bruucbt  tu|;cth«r  belore  the  blast  of  air  begins,  the  Towel  u  nronouiiced  with 
the  «7>in'twi /rnu.  The  Arabic  II  Is  prudiiced  by  closing  lli«  rima  vocAlis, 
the  fjiijfKitlis  aud  fulae  vocal  cords  being  deprased,  and  eeodiog  a  blast  of 
air  thniu^-h  Uir  rimti  rusgiiruturia. 

On  nuiiiy  uf  tlui  abuve  ixiitils,  bowevor,  there  are  gnat  diflerencee  of 
ofitniitii.  ihc  dbicuMiiiH  of  uhtcb  Hs  neli  as  of  other  more  rare  cousoiiaDlal 
■ouiida  would  l««d  us  too  far  away  from  the  purpose  nf  thid  book.  The  fol- 
lowing tabular  •taionient  must,  iber«furt:,  be  regarded  ad  introduced  for  cou- 
venienrv  only. 

Rxi-UHIVES.  Latiait,     witliout  voice    ....  P. 

JMiaU,     wilh  mice D. 

Drittal;      without  vnicP     .     .     .     .  T. 

DtnlaU.     with  voice D. 

f}vltnriiU.  Tt'nUoMi  soiix    ....  K(bardC). 

QillHriiU.  nilh  voice Q  (hant). 

Abpibati».     lAbialt,     without  voiw    ....  P. 

Ijabialt,     with  voice V. 

DatiaU,     without  voice    ....  L.  8,  (toft  C),  Sh.  Th  (biinl), 

Detttatt,     wilh  voice  2.  ZU  (Ediuhiv,  ihePreoch  jl, 

Th  (soft). 

Oniffum/f,  without  voice    ....  Cll  (as  in /ee&). 

Oaffwnib,  with  vcMce Oil  (ss  in  ft>«ijFA), 

OXAim.    Jjobial.  H. 

itaiioA         N, 

Oyltumt, >■(), 

ViBXATOXT.  labial,      not  known  in  Riimpean  «|>eeoh. 

Vrulal,       K  (common). 

fMtvral,    K  (guttural  |. 

Whitperinj;  ia  s|)cech  irilWit  any  emjiloynHTnt  i>f  ihi;  vocal  cords,  and  is 
rllM-ted  chiefly  by  Ihe  li|ti  niid  tongue.  Hence,  in  whimpering  the  diitinelioii 
bt'twcen  omiwiiiuMl.*  needing  and  tlxine  not  nceiling  voice,  soch  as  B  and  I', 
bvcomea  for  the  niovt  |iaTt  lost. 


IjOCOhotor  MK(;iiAN[eH6. 

The  skeletal  muttclea  are  for  the  most  pnrt  amnged  to  act  on  Ihe  bonea 
and  cartihigi'ti  a*  on  levers,  exnniplra  of  the  first  kind  of  lover  being  miv, 
and  ihosc  of  the  third  kind,  where  tho  poncr  is  applied  umer  li>  the  fulcrum 
than  is  the  iTaght>  being  more  common  than  tlio  second.  ThU  arines  from 
the  fact  ihnt  i1m>  movemcDts  of  the  body  are  chiefly  directed  ti>  moving  oom- 

Saratively  light  weights  through  a  great  distance,  or  through  a  certain 
istaoce  Kith  great  precifion,  rather  tluui  to  moving  heavy  wctgfau  through 
a  short  distance.  Ihe  l\itcTiini  is  generally  supplied  br  a  (perwct  or  imper- 
fect) joint,  and  one  end  of  the  acting  muscle  is  made  ust  by  t>eing  attachcil 
either  to  a  fixed  i>oinl,  or  to  some  |Hjint  rendered  fixed  for  the  time  bejiig  by 
the  contra«tion  of  other  miuclet^  There  are  few  movement*  of  the  body  in 
vhich  one  miucle  only  it  concerned ;  iu  the  majority  of  cases  Kveml  muscles 
act  together  in  concert ;  nearly  all  our  moveuenti  an  coordiiuUo  iuov«iu«Dt». 

62 


978 


SPECIAL   MrSCl'LAH    MRCIIAMnMS. 


^Vltere  gravity  or  the  elastic  reifltion  of  tlie  pnrt»  mrted  on  dim  not  ailiirf  ■ 
Millideni  tuiIaKunum  tu  the  coulni'tioa  of  a  (nuMl6or  group  nf  iiia»cl«s, ibl 
return  lo  tbc  oocHlitiou  uf  ei|uilibniim  i^  providMl  for  by  lfa«  Bctiiiii  piUur 
ctiutic  ur  ooulractile  of  a  set  of  aniu^oislic  lumcka ;  thii  ia  Men  in  tht-  ca« 
of  ibe  fiu'e. 

Tlie  ertct  pnflarr,  in  which  the  weight  of  tlii'  body  is  borne  by  the  jiUdlu 
arcbck>,  Li  tlie  rt>aiilt  of  a  Miries  of  coDtracttoiiM  »f  the  iim»i>l««  >tt  tlie  iruid 
Hii(t  legH,  hiiriu^  for  their  object  the  keepiiij^  tht-  bixly  in  Mudi  a  poiitlnn  tbi 
the  liiiL'  (if  gravity  falU  within  the  iircu  of  the  fwt.  That  ibis  Aom  ntuii* 
mui>ciilur  L'XcrtioD  ii  aliDwn  by  tlw  facU,  that  a  iienoii  uIh-ii  titAOiJing  p«- 
ffN'tly  lit  rtwt  iu  a  oumpletely  hiiluiiceil  ]in«ilt<tn  fall*  nhen  hv  become*  ub- 
miwriciuN,  ant!  thatadMuI  Kxly  cannot  Witetun  lU  feet.  The  liooof  gnrilT 
vf  Ihf  ititail  latN  in  front  of  the  iwcdpttal  articulation,  a«  ■•  abown  bjr  thii 
nodiling  iif  the  liMid  in  ntcvp.  Tlx'  trnlw  i>f  (gravity  of  the  coiobiiMd  nnd 
and  trunk  lic«  at  uhnut  the  level  »f  the  entiifi>rm  cartilnicc,  in  front  of  tbf 
tenth  dorail  vertebra,  and  tbc  line  of  gravity  draun  fmui  it  |in««*  behimlt 
line  (oining  the  ceiitri«  of  the  two  hip-j<>iiil«.  xi  that  t)K>  <irec-t  Iw>)y  would 
fall  Mckwairl  were  it  not  for  tl)e  action  of  the  must'li'si  pftsning  from  tk 
thighs  to  the  ]w\\u  aMistod  by  the  anterior  tiganieDie  vf  the  hii>-ji>iDl&  Tht 
line  of  gravity  of  the  combined  hcaid.  trunk  and  thighs  falls  niorrovtri 
little  behind  the  knee-joints,  m  that  «om«.  thiKigh  little,  muscular  osertioa  it 
ret|uired  to  prevent  the  knees  from  being  bent.  Lastly,  the  tine  of  gtanij 
of  tile  wliolo  body  iitii^se^  in  front  of  the  line  drawn  betireeu  the  two  anklv- 
joints,  the  centiv  ol  (gravity  of  the  wliole  bo<)y  being  plaoe'l  at  the  end  u( 
the  sacrum ;  hence  some  exertion  of  the  musclm  of  the  calvea  is  r»|uirad  la 
prevent  the  body  falling  forward. 

Iu  uiiUiuff,  tliere  is  iu  each  stop  a  moment  at  which  the  body  rwts  vcfti- 
vallv  on  the  foot  of  oue,  Miy  the  right  leg,  while  tlie  other,  tlie  Ivft  kg,  ii 
iueliue'l  ubli<]uelr  behind  niih  the  hvel  raiMid  and  the  (oc  mtin|;oaiW 
grouud.     The  len  lej;.  xlightly  llexeil  to  a\-(>id  eonuci  with  the  grognd. » 
then  swung  forward  like  a  [wnduluni.  (he  length  of  the  >wing  ur  atap  inhf 
d«t«rmi»«<)  by  thv  length  of  the  l«g;  aiul  th«  left  tov'  is  hninghl  to  ikt 
ground.    Ou  thi«  lull  ton  as  a  fulcrum,  the  body  is  moved  forward,  the  oanir* 
M  enivity  of  tbc  bo<ly  divcribin^  a  cnr^'e  the  convoxity  of  which  is  upwud 
ana  tbc  left  Ic^  necrssarity  becoming  straight  and  rigid.     As  the  Ifody  iniini 
forward,  a  pom!  n-ill  b«i  reached  similar  to  that  with  which  wv  anupoMd  ik 
step  to  be  started,  the  body  resting  vertically  on  the  \ct\  foot,  and  tbe  rij^ 
Ifig  being  directed  behind  i^n  an  oblir|ne  position.     The  movement  on  lh«  wl 
Jbot,  however,  carries  the  body  beyond  this  point,  and  in  doing  »u  swinj;!  ih* 
right  leg  forward  until  it  is  the  length  of  a  step  in  wlvanc«  of  its  nreriNi 
poattoD.  and  its  toe  in  turn  forms  a  fulcrum  on  which  the  iKHty,  and  with  it 
tlie  lefl  leg,  is  again  swung  forward.     Meuee  in  succeasive  steps  the  eoolR 
of  gravity,  and  with  it  the  top  of  the  head,  describes  a  series  of  ooosecutin 
curves,  witli  their  convexities  upward,  very  simitar  to  the  line  of  flight  of 
many  birds. 

Sinee  in  standing  on  both  feet  the  line  of  gravity  faUs  betweeu  the  im 
feet,  a  lateral  diiplacement  gf  the  centre  of  gravity  ia  necenary  in  nrder  w 
balance  the  body  on  one  foot.  Heuee  iu  walltiag  the  centre  of  gravity  lU- 
■oriliea  not  only  a  aerie*  of  rerlleal,  but  aiwi  a  series  of  hortxoiital  eurvw, 
inaamuch  as  at  encb  ntep  the  liii'-  »f  gravity  t«  made  to  fall  altematelr  iia 
each  siandlug  foot.  While  the  left  le^  is  swinging,  the  line  uf  gravity  fslU 
withiu  the  area  of  the  right  font,  and  the  centre  «f  gravity  la  ou  the  right 
side  of  the  pelvij.    As  the  toll  foot  bucomi»  the  standing  foot,  the  ceoiiw  tif 

■  Tlililn<n<al«>iaTlM|B«kiitiliuuMI)e<knatanierlkuinMactaBlinBWce;  niuH|i««>,>lsraItM 
ti^l  lo  III*  crauiul  fliM.  Uitt  wnUiA  wait  Uw  tat  i-oalnt  kiMt. 


tOCOMOTOR    MECRAyiSIIS. 


I 

I 
I 


itrnvily  U  stiifttNl  lii  tliu  left  *ii]e  of  the  pelvis.  Th«  ftotud  curve  iKvcriboJ 
hf  \\w  wnirc  of  f^ivity  U,  lliercf  in>,  ii  Romcwliiit  compHc&Ucl  one,  Wing 
eompowd  of  vcrticnl  ainl  h»ri/.i>iitHl  factor:).  Th«  iiAluml  tlcji  i«  llic  ono 
whioh  >■  ilct«rmini-jl  hy  lliu  leii^i.U  of  tliu  awinjiii^  \cg,  shioe  till*  ncU  il*  R 
prndiilum ;  nn<l  hvna:  th«i  Kt«p  of  n  loiiK-lvegoil  pcnun  it  nnturully  Imigur 
tlinn  tliiitof  ft  purs-)!)  wilh  short  tefr*-  The  length  of  the  t'jep.  hoiruvdr,  may 
b*  diminished  or  iDcivaiBi)  hy  n  direct  intiiiciniir  cflr>rt,  u*  when  a  linQ  of 
Boldicrs  kocp  Mcp  in  Mpite  of  ihcir  hnving  Icn  of  diftorcnt  length*.  Such  n 
mwle  of  mnrching  must  obviously  tij  fiit)sniu|,  inumuch  m  tt  involves  au 
unDeoesBary  expc^nditurv  of  energy*. 

In  aloir  »-nlkiiig  thorv  it  nn  approciablo  time, during  which,  while  ona  foil 
M  alreadv  in  pnsilioii  in  serve  iis  u  fiilcmm,  thf  other,  stringing,  f  )o:  h»  not 
nt  left  tne  ground.  In  fiwt  wnlking  this  period  is  so  much  reduced  Chatooe 
Mot  leaves  tn«  gniund  thir  monieni  the  other  tiitiche^  it ;  hence  (here  is  prao- 
tMMlly  no  period  during  which  both  foot  ar«  on  ihe  ground  together. 

When  llie  body  b  swung  forward  an  the  one  foot  acting  as  a  futoriiru 
will)  Huch  energv  that  thU  fout  leaves  the  ground  before  the  other,  swinging, 
foot  has  mched  the  ground,  there  being  nn  interval  during  which  neither 
foot  a  on  the  ground,  the  penon  is  said  to  be  rumiina,  not  walltiog. 

Id  jumping,  this  proi>tilsion  of  the  body  lakee  plooe  od  both  foet  at  the 
attoie  tim«;  in  ho|^ing,  it  is  effi^cied  on  one  foot  only. 

The  loooiDotJi>norfour-foot«d  aniiuale  m  neeensrily  morecompliuat«d  tiian 
thai  ofiDnn.  The  ninple  walk,  such  as  that  of  the  horse,  is  exeout«d  in  four 
liniM,  witli  II  dittgonal  lucoeMion ;  thus,  right  forc-IeK,  left  hind-leg,  left  for«> 
l«g>  right  bind.lvg.  In  the  auhle,  such  as  that  of  the  camel,  the  two  fe«t  of 
the  Mine  *iili'  are  put  dowu  at  one  and  the  Mme  time,  this  movi-mmt  being 
foilowfv)  by  a  similar  mnvument  of  the  ollmr  two  legs ;  it  enrrcapomU,  there- 
fore, v«ry  closely  [i>  bumim  walking.  In  the  Irot,  which  orrctpondt  to 
hiiiiian  running,  the  two  diagonally  opposite  fiict  arc  brought  to  the  ground 
at  the  same  time,  nnd  the  body  is  propellml  fnrnard  on  them.  Concemiux 
this,  however,  as  well  oonceroilig  the  still  mora  complicated  gallop  and 
canier,  observers  are  not  ftgreod,  ftnd  much  disousion  ha^  arisen. 

The  other  problems  connectod  with  the  action  of  thit  various  skeletal 
muaclee  of  the  body  are  loo  s[>ecial  to  he  canei^lered  here. 


BOOK   IV. 

THC  TimVS  AND  MhrilANISMS  OK  RKPRODUOTION. 


CHAPTER    I. 


I 

I 
I 


ORGANS  OP  BEPBODUCTIOS. 

Manv  of  ibe  indivIJukl  constituent  pnrU  uf  the  b9dr  nm  ca|<able  uf 
Kprodiiction — iV.,  tlicy  vnn  givu  rim  tu  parla  like  ihciDWIveR:  or  thtj  are 
ca|>abl«  of  ifgvncnUin— 1.«.,  their  places  ciin  b<  taken  bj*  nev  ptrU  rnire 
or  len  clowlr  irm-mbliiig  tlinm»i>lirei^  Tbe  ctemeiiury  tiwuea  undergo  iJiiring 
liTe  II  vciY  large  amuuDt  of  rogencnition.  ThuD.  (he  old  epitlielium  ocntei 
irbich  fnllBwar  from  Ibp  Biirfnca  of  the  body  nre  Hucce«<:lod  by  now  st-alM 
from  tbe  uiHlerlyiiig  liiri^ra  of  the  opidermiit :  old  bk>iid>oorpuSGlea  give  place 
to  avif  onra;  norD-uiit  miiHclos,  or  tlutse  wbith  have  fuled  fh>ni  diswse,  an 
r«ii«ir«l  by  the  lu.'omtioo  uf  frceb  Hbra ;  divided  iiorvei  graw  agaio ;  brukpD 
boD«  arc  unilod ;  connective  tinue  aeenu  to  diMppear  and  appear  atni'»t 
without  limit ;  new  mcTvtiog  cells  take  tbe  plan  of  tlM  old  unea  which  are 
cofet  ofl*;  in  fact,  with  the  exception  of  aome  cne*.  sueb  a*  cartilage,  and 
then  doubtful  esceptioiu,  all  iho-e  fuufUmcDlAl  tiMue*  of  the  body,  ubicb 
do  not  f»nn  pan  of  highly  diflvnTiitiatod  organs,  arv,  within  limit-t  (ixeil 
morr  by  bulk  lima  by  anything  ol«o.  capable  of  regeneration.  That  re- 
generation by  NibnitutioD  of  molecules,  which  is  the  basta  of  all  lifu,  U 
aooomiwnicd  by  a  r^neraUon  by  aubstttutioo  of  m«M. 

In  tne  higher  animals  njffenermtion  of  whole  ori;aiu  and  membsra,  evan 
of  ihoM  nhoM  conliniicd  njDCtional  aetivitr  is  not  cwential  to  the  ««U> 
being  of  the  body,  is  never  witneseed,  lliuugK  it  may  be  wea  in  ibo  lowir 
animals:  the  dii;ii«  uf  a  uewt  may  be  restored  by  growth,  but  not  lb«M  of 
H  man.  And  ilio  n-pair  which  folluwa  even  |>artial  <leurueliofi  of  highly 
differentia  led  organ*,  such  a*  tlif  retina,  i*  in  the  hifjher  animals  very 
imperfect. 

In  the  higher  animals  thv  repnxluciion  of  the  irhole  individual  can  be 
eflTected  In  no  otlier  way  than  by  the  pruci^**  of  Mxiial  Mnerulion,  through 
which  ihe  female  ropmtcnlativt^  element  or  uvum  i*.  under  lh«  influrncip  uf 
th<>   male  reproMntative  or  •permato»)on,  developed   into  an  adult  indi- 
vidual. 

We  do  ni>i  purpose  lo  enter  herv  into  any  of  the  moqiholof^cal  probleins 
CJMtDMted  with  the  eorie«  of  changes  thpjitgh  wlitrh  the  ovum  becomes  (he 
adult  being  :  or  into  the  obscure  binl'>gicar  iniiuiry  as  to  how  the  simple, 
nU-but-^tniclurelcas  ovnm  contains  within  ilMlf,  in  |»teDtialily,  all  its  (btiire 
developinenls,  and  as  to  what  is  the  raseniial  nature  of  the  mate  acUou. 
These  problems  and  quealiomi  are  fully  discusted  eUewhere;  they  do  not 

Eroperly  enter  into  a  work  on  physiolojjy,  eioept  under  tbe  view  that  all 
iological  problems  nre,  when  imslied  far  enouirh,  pliysiolo^iicnl  probleuu. 
We  Bnall  limit  ourtclvet  to  a  lirief  survey  at  the  more  imparljuit  phyaio* 
logionl  phenomena  attendant  ou  the  impregnation  of  tbe  ovum,  and  oa  the 
tliitritton  and  birth  of  the  emhrvo. 


THK   Tiasues  AND    MBCUAM8MS   OP    RSPRODCCTIOX. 


Th«  frmale  orffatif  of  ijtnffalion  lire  nnntoniiciillv  rlivideid  Into  ihf  inv 
and  exteroa)  organs.  I'ho  Inltcr  conifiriM*  Utu  Inliin  untjorn  hhiI  minora,  lla 
clitoria,  the  hriiu'n,  tlio  luentiu  urinanus,  tlic  viilvii-viiciTiul  glumi*.  awl  ita 
tiiurous  aD*J  £«bnccoii8  elands  wliifli  arediHiriUiitnl  in  tlic  rmioiuii  lurmbriiM 
covering  ihe  parts.  The  rxtcmal  organs  piny  n  vpry  milwiiiiiiry  |mri  io  lh» 
function  of  reproductian.  and  tli«}-  will  bo  jniwrd  \>y  witli  lhi*(  brief  doUc*. 

The  inieroal  argana  comprise  the  vajpiia,  uteni«,  PaUupiui  toboi,ud 
oraries. 

The  vagiDa  is  a  niuBculo-meiubraDous  canal,  about  four  to  six  incbn  laa^ 
directed  obli(|ue1y  upward  and  backward,  and  i-xteodiD);  from  (he  hymCBM 
ibe  cen,'ix  iileri,  where  it  is  atiached  at  a  poiat  a  alwrt  distance  aboTc  iht 


Km.  Ml. 


U 


W 


^- 


U 


V 

intoBUounc V»a  ormE  I'lsniB  isum AiTB9iiw«n.ul 

(Frou  Qutol.)  HMir  niKunlilM. 

Ttt  elcniiBU-lu|>i«iiMrlof  tht  ntpjin  hoTV  boi'n  UM  o|vn  br  nmnvliig  lli*p(Mnlor«*U.  IM 

tUiupJin  luV.  rmiiKl  llsuiniit,  •OiloTurlM  IIkuuuiI  Iuk  Ivcn  cnlilwn.and  Uio  Imad  UH'"* 

mnorr-l  in  itic  kn  iidc;  u.  ilic  ii|>(wr  i«n  il  ilii  ownit;  t.  Ibv  tcnli  epK*""  *-^  i»  iiiiimin 

Uw  lilUJu^ilui  >t>«)HiiJt  llivulcTliii>i-«Tit)^|]  thciim,  atiil  Wm  dllstlon  oC  the  conloil  cntlr  i>Bkai 

ragii,  urmaj  arbor  tHk-  r.  upr*r  pan  nf  Ibcvaicluii;  ml,  F*IlD|4iu  lube  or  otIiIufI  :  Uw  iim-d* 

oniiiMinlcalkiD  of  lu  carJIjr  vlth  iBmoI  UiacORiunr  lliv  iitpni  t  oo  «a(k  >lila  Um«D:  t.  nniigtn^ 

iiwDI:l».IISUiieiilrtr  lliBonry;  0,<ntTf .  i  wide  ourlcrput  or  Uic  Tl«l<t  1^nflf*ui  lti*«,lL<a 

nnitelitl*<l*alnmlt]'-.  jin.  twoTBrtuin ;  Koavotxtia  br«MI>b  Ovq<in>ll)  rxml  tiDniuriad  vnili 

bmul  UfKIDCDI. 


OS  uteri.  Its  iralli  cotiMsit  of  an  cslenial  cost  of  limgiiudiital  mutcultf 
fibres,  a  niiddie  eri'dilu  c<^at,  iind  an  internal  mucwis  coal.  The  miiOia 
nK'Uilinaiie  id  cviulinumi.i  hclow  with  ihat  covering  the  extcruitl  geuiult,  s»l 
alxivc  with  the  munius  nii'nibrsne  lining  ibc  uicniB.  The  anterior  nntl  ym- 
tvrii>r  «urla(.-CR  are  marked  bv  longituiliual  folds  or  raphe,  from  wliichs 
numlwr  of  trdjisvcne  fi'l«ls  are  giveji  od'.  Tliifi  niembraue  Is  pruvi<ie(l  nith 
niuctMis  gliiiidx,  ami  is  lliickir  covertd  with  senailive  papillcc. 

TIh!  uterus  is  a  flattened,  pmforni.  muscular  or-^an  (Fig.  ^61).  Aaa^ 
lumically  it  is  divided  into  the  fuoduf,  neck, and  cervix.  TIh-  nevk  indicnM 
the  point  of  division  between  tbe  lower  coDslrided  purlioii,  which  i»  th 
cen'ix,  and  the  upptr  expanded  portion,  tlie  fundun.  Tk«  cervix,  which 
extends  from  (he  neck  (o  the  end  of  tbe  orxan,  projects  into  Uic  va|;iiM,il 
which  point  it  is  marked  by  a  triiDsvene  ftMiirc,  uallvtl  the  o>  iteri. 

The  cavity  of  the  uterus  is  soinewlinl  triangular  in  shn|>c,  and  rery  modi 


ANATOMY    OP    THE   UUOAX8   OF   OKNBRATlOy, 


U83 


Rlten^l  •nlPDJ  |«iBipriorly.    Tlie  iaft-rinr  aDKl"  of  ibe  cavity  i»  ontiuuous 

nilh  till-  i-iwhI   niniiiii);  tbrciuglt  llie  M-rvix  bi  tbe  vajfins.     The  superior 

anwlMiireMlIci)  ilicconiua:  iit  tlii-boiioia  itfradi  iian  orificeof  a  Fallopian 

tUM.    Tbe  utcriM  i*  coaiixMi'd  nf  three  coats :  a  veroiiii  (fomied  by  tlie  ]ieri- 

tmictiD)).  n  niuHrtilnr,  ituA  ii  miioiitiii  iviat.     The  miicoua  rant  a  L>outiDUi>iiit 

uilh    tliitt    lining  ilm    Fiillopisn    Iij1>n>  nn<l    vnxiiiii.      It  u  (.'4iv«r«il  nith 

■    cilumnnr  cilinlt'il  r|>ithuliiim,  itod,  if  cxniuinvd  with  u  I«dm,  thv  openiiig^  of 

ft  ibo  mucotic  fullidcs  will  W  mou  to  be  very  timfuiwlv  (ti«iribul4>a  over  the 

I  Riirfiiec.     If  n  vertical  wction  be  in«'l«,  aa  in  Fig.  26'X  thv  t»biil««  will  be 


Piu.  Ma 


W> 


;l 


*s 


"m 


RniKW  or  ma  Ukinii  Mumnavi:  «■  a  liini>  I  iu>a  «>  mi.  PuiKdi «r  UuiacMciiM  Thm- 
■ulTT.  lAMttiis  ihc  ■mniFiDini*  wiil  othrt  iimilMrUnof  ihc  (lanih.  ■(.<(. -il.  with  ItwhoiaM*. 
«.«.  n,OB  IhclnEcmai  larHu'ol'  Ibconwn.    Twiue  ibu  nalunlilTC. 


I 


Been  to  be  amnijet]  pcrpeDdicularly  to  the  aurfaw,  having  a  wary  coiinr. 
In  ih*  iinprexDaied  iitenis  lli«y  become  much  swollen  aod  eolarfpfd.  Th« 
niucoui  membrane  lining  the  cerm,  on  account  of  il«  peculiar  a(>)ie»nii)ce, 
is  (rallcJ  the  'irfti/r  viltt  uicrinaa. 

The  Fallupinn  tubon  (Fig.  '261)  are  abont  four  iuehca  in  length,  nml 
vXlMid  from  the  ciimua  of  the  uterut  tu  the  uvariet,  irberc  thcv  en<)  in 
enlarge*!  rxpnndnl  extn'mitic,  the  niarginn  nf  which  are  noven^l  bv  long. 
•trader  pmi'nwi^,  oni-  of  thcni  l>ciug  connected  In  the  nvary.  Tlii«  jKirtitin 
of  the  tube  if  rallc-il  tin-  finihrintecl  extremity.  The  luhw  nrw  cnmpoerit  of  n 
M!rou»,  muMuIiir.  mid  iniicoun  liiyor.  The  miicnnp  momhmne  i»  coverwl 
with  cilintrd  oitutniinr  t^pilhdium. 

The  uvarim  I. Fig.  'Jiil )  nrc  Unliencd,  ovotclal  I>odic«,  which  are  situated 
On«  on  each  aide  of  the  iilerii»,  and  rncliwrd  in  thn  f»li)#  of  the  hnrnd  li(^- 
menla.  They  are  each  ponnpclcd  with  ihr  nlerux  by  a  lignineDt.  and  with 
ihc  Fallopinn  tube  by  one  of  itc  timbrin;.  They  each  connirt  of  a  lilin)U8  cual 
((■(fii'fii  alhuijiiii-a  I  which  encloses  the  *truniB  <if  the  organ,  i,  I'*ig.  'Hi'l.  't  The 
■troma  is  coniprHed  of  a  soft,  vaiteiilar  fibroiis  tiMiie.  having  imiiedded  in  it  a 
nutnber  of  miall  bodies,  called  Grnalian  vesicles,  which  arc  in  divenr  dtagea 
of  devel4^Rient.  Theee  veifeiclee  cinintence  their  development  in  the  deeper 
portions  of  the  orary.  and  as  they  approMch  maturity  gradually  make  their 
way  to  the  surface,  where  Uiey  project  as  pmniinences,  and  tlieir  capmile 
finally  rujrfuring,  diachar^je  ibeir  cunieuts  into  the  Fallopian  tube.  Each 
vesicle  ct>u»iets  of  an  external  coat  furnieil  bv  the  ovary,  an  inicnial  c<>at  or 
capsule,  and  niihin  this  a  layer  of  cella,  wliich  constitutes  iIk-  metibraHa 
r/rniiulomi.  The  interior  of  the  veuicle  O'usisis  of  an  albnniiiimu  lluld,  in 
which  is  sUHpendetl  the  uvule. 

Tlif  mnU  /fenrntlic  ortfint.  Tlie  name  physlologicnl  intere*!  in  not  centred 
in  the  ninle  orgniu  uf  gruL-ration  as  in  tboee  of  the  femnle,  the  priuc)|>al 
iotercM  being  conoculratvd  uiiou  the  organs  which  lu'cretc  the  mali-  duid  by 
which  the  ovuli-  in  impri'giinied.  Our  remarks  will,  then-fore,  be  alnvNt 
■Biirely  cunlim-il  to  the  organ*  oooccmed  in  the  wcrvtion  uf  ihi«  llui<I. 


084     TUB   TISaUBS   and    MECHANISIIS   or   ItKPItOntTCTIOX. 

Th«  ntalfl  ornns  comprise  the  penis,  or  orgnii  f>f  <.'o|)ulmion,  iI)l-  prcwUie 
hhI  C'onpiir'i  gluidA,  the  teeticles,  aad  vaea  defcfWiiia  tuul  vwicuuB  ivin)- 
■titles. 

Tlic  pnwtHlti  Klaod  kiirrrtuiKb  the  neck  of  llie  bioiMor  and  commenoeHieM 
i>f  tlio  iin-lhni  iViic.  '2GA  ].  Il  wi-rolvs  ii  milky  l!ui<l,  irhich  u  oonveyet)  Itj 
(hu  proctutic  iliietd  M  Iho  Hour  of  ibi:  urHbra.  Cowper's  f^laixla  nmao 
rtusll  glaods  wbiebaresiliintcd  beliccvii  ili«  layers  »f  ihe  deep  perinea)  Cue)* 
at  the  aiiU'rior  jiiirt  nf  llie  mombranoiu  urolhrn.  Ttiev  secf«t«  a  visdd  Huij, 
whidi  is  wiivrj-t-d  bv  ducts  to  tbo  floor  of  tlie  iiretbra. 

Tlw  tcatus  or  Uwttclea  are  tiro  small.  Ilatleurd.  oToittul  );litu<ta.  nbleli  an 


VmopiMxnimur ^aiPMicnOVAiiTorTitRt'AT.  lAnn^iiniiH.'       i^ 
t.  onler  covtrlnc  aud  not  hunUc  of  Iha  ororr ;  t'.  alUdbnl  bnnSn;  z  llf  i-nrun  Mn^«.  imrf 
lIV  ■  Uliioiu  bIkI  nuiiiUr  itnitflupr;  A.  KminKiir  «»)Biiinra  lylnit  cili>ni*l  Wlluf  nimiiv  • 

bee:  CoilowiiK  ulil(i||  birr  Iwyun  ui crtluricr  vij  [o  low inon iVviilir  liilnllw  uruy  :  7.  aictcm 
ruuiii]  nlilrli  ilii-  llnstMn  (i.itllnir  uiid  tiiiiloi  rnniiilm  are  iinin  Itonaal.  •■■i)  uliVk  Mn  (Wiri 
w>mvnrhiildot|iariniiriLvivrafy  BL>d  Arv»iirr<i:>aiiilDi]b^UJontbnm'ktrQTua;  K  iUiweartrAiioHtOtiMa* 
MIUcIo  wltli  llii'  litiitii  tntxvMiiil  ill  III.'  lnlTruf  •-v1l>  roiKIIIIiUnc  Ibi-  pntllBPraV' <U<v  ^  t,  ntm^ 
•Anuucd  lOtllvli!  ixiiiUIiilOK  till'  iiTiim.  clo. ;  9'.  m  Rilll«lc  rrnm  wUcli  the  ovum  hiB  wnMNMIV 
wcBlqJ;  lU.  oirpiu  luteiiin. 

«ilu&led  ill  a  niiinciilo-menibniuoiix  ngueb.  cullwl  tbe  Krulum,  and  watfteaiel 
by  th«  epormiitic  cntih.  1-::ich  lf>ttid«  contltla  of  t«o  paru :  tb«  glaud  jDfnpw 
and  tbo  opi<li<)ymw.  The  ginnd  f  Fig.  205)  in  oompMod  of  an  otitor  nbraw 
coal,  tho  hini'i^fi  •i/hu^tnm,  thin  being  covered  by  a  scroti*  mombnuic  tbt 
(tiJitoa  wyini/u.  Tbosubetanoeof  th«Klai)d  pnnnii'ts  nfa  uuiub«r  of  pynm- 
ida]  lobular  divioioiis,  which  are  Mtuat«(t  wilh  their  bnsce  tOwArd  tlleH^ 
fac«.  Ench  lubule  i»ci>nii)OSod  of  servral  convMlud'J  Itibiili  urmini/cri.aai 
arc  oeparated  from  adjninitig  l»bul«  by  prolon^Htinii  of  fibrous  lixuie  fraa 
tbc  tunica  albuginea.  Tfie  tubules  arc  ootuixk'hI  of  a  b»n)ng«aet>u>  biistiBttl 
iuiM)]l>rane,  which  is  lined  by  granular  nucleated  epillKlium.  Id  tbo  >t|i<^ 
of  tbc  lobules  tliey  have  a  stnizht  caur«e.  and  form  tli«  vom  rrcln.  Ther 
then  cnl«r  the  flbroua  tiHUe  of  the  mediastinum  (Fig.  '.^6-3),  and  fvrn  s 
)>l«xu*  of  tubed  calleil  the  rfU  UitU.  nhich  end  in  the  upper  pan  of  lb 
medianlinuro  na  the  iimu  rjfrrenlia,  and  iheiw  becoming  verr  rauoh  convoluted 
form  ihc  gtobia  major  or  head  of  the  epididymis.  The  tubule?  of  the  (•lobw 
iniijor  iiniiu  to  form  a  Hn)[le  tube,  which  i»  very  much  convoluteil.  and  cio- 
liiitut*^  the  Irudy  and  ylobiu  minor  uf  the  epididymis,  and  is  then  cHitinusd 
I'rum  the  glnbu*  minor  to  lh«  baae  of  lli«  bladder  as  tbo  excreturr  dflcf  or 
III*  deferea*. 
The  vt*  dtjrreiu,  eoURienciog  at  the  j^tobus  minor,  ascends  (a  tlio  potttriot 


tWATOlCT  OP  THB  OBOAH8  OP  OByBBATION. 


9SS 


part  oftbeapeniiitic  c^>^l  (I)ri>u2h  the  .Hpinniticcaimt  iFil»thepelvii.  wheni 
It  niDM  lo  tli«  Imw  of  lli<-  )tlnd<[i;r  imj  becumei  culniyeJ,  uciiulaUi),  anJ 
narruw«<t,Mii]  j[>iu«<rilh  tlikMltirl  or  (ho  vuicula  Ne  mill  alii  to  fcirm  a  commuii 
ejsrataton-  tlucl.  Thv  walU  of  the  vii»  ilefomuare  OLimjx^wd  of  librauautd 
mtueular  (iMuft,  which  i«  lined  by  a  nmcou*  mcmbninc  with  oolumnar  cpi- 
iheliuni. 

n.1.  TH.  na.  «a. 


9 


r>9  >M.~TklE  OLMnr  Till  M  >!.■  UUIMIKK,  WITM  THK  VRKOBia  HWUULM  JtXD  PBOtTtnGLUIC. 
I'tAflfT  MllUU.  I.  <IM  orlnuT  blaililer :  'l.lh«  l(>n(>lu4lnftl  lajvr  Of  muMiular  HbtM  i  l.tha|inaUW 
1:  4, BiMBltnuiaiu  potUoa  at  ihs  uniiim:  X  the  urcMn:  A.  bloodnacU :  T.  lei) ;  I,  itgbt  iw 
mm:  >.  !■«  HiBlnnl  nwila  in  tM  iMtunl  inriuuni  iu,4u(iiu4>oaUior1ui«f  tlia  IcA  *lil« 
tnTTMnt  (he  prattaM  cUnil  i  II.  ilgW  wnlnil  *«ol«la  InjBttod  and  unrartllvd  i  12,  U.  blind 
»  winba  <if  *Mleu1»  -.  II.  rl(lki<luDiiu«fuuktunBili«T«nlncUie|if(M«o. 

ne.SSL— «,  lobuIiM:  b.  tom  rvou:  «.  nwdlaMlnuui  ^  <f,  vua  tfltanuiU:  r.  b^T  f^  cpldldjDtU: 
/  nu  loMoi  1 1.  ctobiH  minor ;  A,  ni  dchicM :  I,  lauli'K  albu^iMH  ■nd  II*  Inicrlobalar  rtHeellon* : 
E    /. ■Ii>taimijar. 

■  A  rin.  y«  t< 

1  -t  •  '  • 

■  4, 8FMK110M1  rnoic  TIM  tlnuM  Vm  UNnanin.   lAiivr  Xau4s«N.> 

'        I.  nwyii»rt  »"  ■■■  — *"  ■  ^MitDllk>lMndlaMMtn:a.  mUwiUc;k(lomkbn<» 
li.8rc>iuTKCKUjiA)<tiiMMUi«aa<iorTnaliuu.UiniuHMira  Pktiuu-mivt. 
(Alitr  Kmuku^   M-1. 
l,it«ia«llo  otOk  wHkOMM  taw  Dudol.  una  oftkiatfawr;  1.1,  hot  ■uakC  witb  (wciaMM 
lU  IbnMlni :  I.  tlw  BlawHIM  ttaa^Uii  mH  ih*  bodf  ttldtMil :  4.  MamtWi  Mitrlr  <1amd(aa. 


le  iwnoN&SMmitwifMaratwuQtoiigauJ  MceultCAd  badiet,pUccd  oxtonul 
to  the  vaM  defereotia.  Tbo  structure  of  the  aomlDil  T«gicl«a  b  simiUr  to 
tlial  of  the  maa  deferentia,  cuiui«tiiig  of  a  fibra-musctibir  «ral1  linod  with  a 


986     THE  TISSUES   AND    UECnANlSVS   OF    BEPBODtJCTIrtt. 


inucou*  ni(iiibriin«,  which  u  covi^red  by  (jranuliir,  nucleated,  poly§:ocial  qj- 
ihi'lium  ocllf.  Tbive  orgnnn  Acrve  as  rei-epliclea  for  tbe  BeoiiRnl  Quid 
ri-eivti-d  by  lli<^  t<-Klci>,  luxl  iiL  the  »aitie  time  prnluce  a  secretion  of  thnr  own 
wbicb  in  mUlt'il  to  It.  Thd  vjii<:ulnlury  duc-ts,  wbicli  are  tbrmed  by  tb«  unk« 
of  tbo  duct*  i>f  tbo  viiMi  d4;ti:n-iititi  und  veeiculx  teniinaltd,  open  inlo  ibe 
prwrtatic  portmn  of  lh<-  iin-lbrn.  Tbrlr  ettatti  are  ihiiiiier,  but  bare  aawDluUjr 
th«  nmv  xltucltin-  »»  tb<i  vii>a  dcfrn-tilin,  uitli  which  tbey  are  conUnuoui. 

Tli«  grmina!  jtui'l  in  n  (imiplcx  wcrrlioD,  being  cc>ni[Htf(^l  of  the  anMunical 
clrmeiit*  nf  rprTinaioioa,  which  are  IbrnM'ri  in  the  tntei.  luid  of  the  aecrelMiu 
of  ihc  VM*  ucforcniia,  vwiciihi,i  wniiwiiUv,  the  prwtiili'  and  Cowiwr's  glaadi, 
and  iho  niueoutt  glnmU  of  thi?  iin-lhm.  The  Mmiiiul  Siiid  ia  of  a  thMc, 
wblliih,  Ftrinlcd  nppcnriinrc,  and,  if  cxninimd  niicrtiw.-opic«llT,  is  teen  to 
rotilain  innumcntblr  bodicv  nbicli  iim  in  aclivp  moliim.  Thcac  *n  tW 
t>po^^mtol;oid^  and  nn  ibc  cwcniinl  mali?  clomrnt*  cinrrrui'd  in  ihi;  ftiounda- 
tion  of  the  ovule.  Kiich  of  Ituve  bodies  (Pig.  '2fi^>  c<iu»iel«  nf  a  flaUtoed. 
OToidal  hc&d,  havin)^  at  Us  bo«e  u  tapering  caiidntt-  appcfldue  in  acttre 
vibniiilc  motion.  Theee  aiialoniicfll  elem<-nt«  were  nl  tirM  caoriwrcl  aniioot- 
cuJA,  but  they  are  now  looked  upon  us  free  maseee  of  protoplasm  with  ciliu; 
apneiidsges,  which  endow  them  with  the  power  of  migration. 

The  fipcrmatoEOA  are  developed  from  the  nuclei  of  veeiclea  which  an 
formed  in  ibe  tubules  of  the  teatea,  Tbe  nuclei  are  metamorphosed  iau 
the  heads  of  the  spcrmnloxoa,  the  ciliary  appcaidages  being  afterward  derd- 
oped  as  a  eon  of  ouigriiwih.  Different  stages  of  tbe  developroeni  ui 
other  interesting  features  are  »liown  in  the  atiuve  figure.] 


CHAPTER  II. 


MENSTRUATION. 


From  pub«rty,  which  orcure  nt  from  13  lo  17  yrtin  it  H|re,  li>  ihu 
climftcUric,  whkli  arnvi-»  nt  frum  •l-'i  to  'tO  years  of  iige>  ihi.-  humau  reninlv 
is  Mihieci  to  n  nKiiithly  <li«cliurgc  of  ova  fniin  the  ovnrw».  iiccoiiipanicd  by 
special  ehmiftM,  not  ooly  in  lhu»e  orf^nOB  but  fll«o  io  ibr  FallupiaD  IuIh* 
and  iitenjii,  ni  well  ns  hy  general  cIihii^fh  in  tbe  body  at  Inrgc,  ilie  wlioir 
eooMilutiiig    "  nirnslniatian."     The  e«Bential  event   in  nitrnitruntioD  is  tlw 


jK  nt  HI)  ovum  froDi  iIb  GraafisD  Tollicle  [Fig-  26T].  The  whole  ov&ry 
at  this  tiau)  bccomce  coDg»ud,  anil  the  ripe  follicle  bulgrs  from  ilt>  eurfacv. 
The  mcwt  projecring  portion  of  the  wall  of  the  fnlliclc,  whM'h  has  previuuely 


|Fl.,    JIT, 


Fw.  aw. 


I  riii.'JW,  8»rnoetorG»<L*funlbuji.xaor  *  Uuuui.  iARh  VoxKiiia.)  t. iinnuaurtlieuTafj 
B  atili  tJM4*WMl*:  %p(ritoaeuui  S  and  1.  Urtx  at  Uie  ciitniBl  ouiof  ilieiinuOiui  ftiUk'lc:  3>. 
I    ntiMlWIii  (nankai  -.  C  niUd  of  Itiv  (tnulbiii  nilUcle- :  T.  imDUliir  oiiir.  ur  iKirut  irtoltttfvt,  von- 

■   lalnlnallMovnIvOi. 

FM.  IM^Ovcu  or  TtiK  Soir.   lAIUf  Ai.B«v.)    I.  inffmliKl  •pol ;  I,  fennliid  nalcia ;  R.  folk ,  1. 
M(M  fdlutlila :  \  dlKLO*  |irellgm* ;  It,  Kilbennl  gmnuh*  or  nlla-] 

becoine  exeeatiirely  Ihin,  is  now  ruptuT4<l,  Bn<l  the  ovum,  nhic-h  liaviuii  l»ft 
its  enrlipr  potiiltoii.  in  lying  cImo  untli-r  thv  projeclinK  Mirfare  of  ibc  roUiele, 
eaoupet,  together  with  the  cclli  uf  lh«  dinnm  jiroii'jiivi  [Fif[.  26d],  into  ibp 
Fallopjaii  lube.  How  ihc  ciitrani-i^  <-f  (he  oviiiit  info  llir  Fnllopian  ttiW  U 
MCuml  in  not  extti'tly  kiiouii,  8<>ni4'  mainlnin  ihal  ihr  oriiry  ia  graniwil  by 
the  lrum[M.-i-*hapc>(I  fiinliriati'<l  moiilh  of  thu  I'altopian  tube.  ilrHf  liir^icl 
HD<I  oitifctflvd ;  tlw  iiiovnnonlB  nccw»arj-  to  bring  ihi»  about  bi-ing  elfccUd 
by  the  |tlain  ffiii«nilar  tilirca  pment  in  the  nM>ui1i  of  lh<'  inbff,  (^herv,  ro- 
jetting  this  vii'ff,  ami  Rm:iling  that  the  turecscencv  of  the  lube  dooa  not 
ucair  nntil  aAer  the  ovum  has  Iwcome  safely  lodged  in  the  tube,  euggesls 
that  tbcovuin  is  carri<tl  in  (he  propiT  direction  by  currents  in  the  peritoneal 
cavity  »el  up  bv  the  action  of  tho  eilialed  epitheliinn  lining  ibe  luW,  cur- 
rents whose  drreclioii  and  strength  *ttm,  as  shown  by  cipeiinient.  lo  b« 
nde()iialo  to  carrv  into  the  uterus  particles  present  in  the  ptritnncal  flnid. 
Arrived  in  the  lube,  llie  ovum  travels  downward,  very  slowly,  by  the  actinn 
probably  of  ibe  cilia  liuJii;;  lite  lulie.  thtinph  poMihly  its  prt'grets  niay 
oocoaioaally  he  aMialed  by  the  peii^laltic  eonlraclii'ne  of  the  niuccular  walls. 
The  alay  of  Ihe  nvuni  in  the  Fallupiau  tube  may  extend  to  tevcral  day*. 
There  ia  an  (truBiim  of  blotid  into  the  ruptured  follicle.whieh  is  §uhfci|urnily 
tiillowed  by  histologitul  changtA  in  ibe  eoaU  of  ihe  follicle  letulllng  in  a 


MRKSTRUATIOK'. 

imrnin  tuteum'  [Pig.  '2H!>J.  The  disebargo  of  tho  ovum  i«  ncompMiw) 
only  by  a  coiigcetion  or  erection  of  the  ovary  and  Fallopian  tuUr.  bul  abti* 
by  marked  chun^efi  in  the  uterus,  e!^[>ecially  Id  ifae  ut«ria«  tniiiv>ut  cd«'Iii 
brnne.  While  the  whnle  orffao  bscomea  oangeeted  and  enlarged,  tha  niacKii 
membrane,  ikml  wpei^iallv  the  uterine  glano*.  are  distinctly  hypcrlropht»l. 
The  swollen  iiileriial  aiirfdce  is  thfDwn  into  fohU  which  almost  ouliUir4tr  iW 
csvilv  :  anil  a  heiunrrhuifio  dlsi-h^r^'e,  oden  cimiidenble  in  extent,  couftilnl- 
ing  the  meiuimal  or  catumeuial  tinw,  takes  place  from  the  greater  port  of 
ita  Burfaoe.  The  blond  lu  !t  pna^ei  thmngh  the  vazina  beoomaa  auai««hit 
altered  by  the  acid  secretions  nf  that  pauage,  and  when  soaaty  coa|[(ilaUi 


(Be- 


lu«^  »  VKimiui.eaLinair>.  Al  n  kahnwii  ibc  lUU  »f  (ho  IblUrit  IsmnlluHr  aAar  tlwctinl- 
■l(in  of  Uw  ariitft  It*  Mflty  bolni  nllvJ  w<ili  lii>»l  aiil  no  ui*n«lile  Inirawe  of  Hi  artlMW 
UiiUw  litvlns  yM  ■■t*Dpliipe  .  ai  (s  IMakonliif  ot  ttitt  hnlnx  bu  binotna  ai-parfsl:  ti  f  ittafW 
(11  pn^t  ruldi  wbic'h  nrf  <|.>i  i>iiii<il  ut  il,  sitl  ilio  clulnf  (ibtod  b  ibaortL-]  ^t"  >'»'>.  anil  MO* 
MinallfMiJwulnriivd  ;  ■  Piiilla'i(i>i»  nf  Uif  urns  I'luivo.  ai  *iu>«ii  at  r, /,  u,  *,  tjtiiu  ih>  lui^ 
luMom.  nllb  Ite  dalloate  d«lrlx.] 

but  eliehtly;  when  the  How,  however,  is  considerable,  distinct  dot*  may 
nuJce  t^wr'appea.rani«.  The  iwolleu  and  hyperlrophicd  mncoaB  niopikiane 
then  uudergoea  a  rapid  de^nenitiun,  and  b  shed,  passing  away  aomctirao  ia 
distinct  ninaaa).  forming  the  latter  part  of  the  raeDHtrual  flow.  The  lift  •>( 
the  mucous  Dienibnute  U  nn  complete,  Uiat  the  buses  only  of  the  iitenne 

Slandf  aru  \e(i,  and  fniin  tho  epithelial  oella  lining  theec  the  regeneration  uf 
i«  new  iiieinbrano  is  #nid  to  take  place.  It  ia  not  certain  that  meostnia- 
tion,  in  the  liumiin  subject  nt  all  evemtat,  in  always  accompnnied  byaillt- 
charge  of  an  ovum ;  inJocd  ca#cs  have  been  reconled  in  which  menBtraatiao 
oontioued  after  what  appi^arcil  to  bo  complete  removal  of  both  ovariea   Ati 


(■  Tb«litl'>afD(labulatitiUEiB:tit  tiy  lUtibQ liipi 
■nil  lilMUa  cf  Ibc  ooQ-pnf  iiaui  ai'l  |i'''V>o"i  n"iu: 


<lw  pclMl|itl  dllEfl 


bM 


At  Itr.  nul  </  MrM 

■imfei. 

OM  lamA. 
AnauMftL 


COkm  U-TBi'it  or  PuoMawT. 


1 


i-y«iT<  Iji-cei'u  or  Mi:-iyrHL'Anoc(. 
Thnw-iiiiinin  at  mi  liu'li  III  •llaiii' 

wall  trttclit  nt-  !  I«Tirirr,  toutoIuimI  nlUi  brtrU  f* 

iiltik.  I      to*,  dot •1111  rwMltli. 

lt>-i'".-fi  v.;r^r,pniliUMioIan  liitlj.  ,  9o*«»«ljlMlia  of  an  ln«h  iH  *adK»«. 
iilAuul  uloaMi-  WWcJillaa  «all  ■■'Vt^l  r*^'  .  f*^ 

BiKl  ^^' '    -  ■■»  li  rni  of  MM* 


Alwiit. 


AbMM 


I  on,.  I.  , ..,  ,■! .-,.  Maml 

ci..  ,-ln<l>» 

In  iiilanli)} 

any  bctfM  tbIIo*  «Dl»r,  i 


MKNSTKl' ATIU:'. 


'Jiii> 


II  weni»  pr(ihnb?e  bIvo  ibnt  under  ccrtnin  drcuDittKiuefi,  e.  g.,  coilui,  s  dig- 
cbarge  ol  an  uvuiu  uiay  lake  place  at  otber  tmn  iban  at  the  niemuual 
jxTioi).  Siiico,  biiwe\<^r.  ilio  lini«  during  wbich  both  tb«  oviini  and  rhe 
([tcntisiouyiii  may  rfniiiiu  In  (be  lenale  patftgEtt  aliv«  aitil  imtciibDally 
atimblu  i«  coaaide ruble,  probubly  cxtendinc  to  soiiie  days,  loiiuit  elTecicd 
ritWr  Mine  time  aHer  or  foin«  time  before  the  menhir  mil  ebtat>t-  ul  aii  ovuiu 
nii^bt  Irud  to  iti]|)K)tiiiilioii  aud  tubKQucnl  devi'liijimciil  oI'  an  ttnbryo; 
hrnci*  tbc  fiii-l  tlint  iiiifin-^nution  may  follow  upun  wiiub  ut  tuaw  time  alter 
or  hefiirr  intnotruntiuD  \»  no  very  co^'ent  Hr)(Ui»fDt  in  favvr  of  ibe  view  that 
eucb  u  0(iitii>  bay  caused  an  ludti^udiDl  eicajio  of  an  ovum.  Tlie  etcape  nf 
Ibe  ovum  i»  mid  to  i>rende,  ralbrr  iban  coineidc  witb  nr  fotlow,  the  min- 
mcnial  flow.  If  no  fpcrmntoxim  vnmv  in  contact  with  ibL'  ovum  it  din,  ihv 
uterine  mrmbraixi  rt'lurns  to  it*  normal  condition,  and  »■>  trace  of  ilic  di*- 
i'liar^  of  an  ovum  it  lell,  escept  the  corpUN  luteum  in  tbc  ovmty. 

It  ie  obviou*  thnl  in  lbf»^  jibrnummii  of  menxir nation  we  nnve  to  deal 
with  complicated  rrllcx  avlionx  alfi-cling  not  only  tbc  vnKiilar  supply  but, 
apparently  in  n  dirrct  mnnner,  iKc  nutritive  cbanpt  of  the  organu  con- 
cerned. Our  studies  on  the  nmotis  action  of  M'en-tion  render  it  co»y  for  us 
to  conceive  in  n  general  nay  how  ihe  stveni  event*  are  hroiiehl  iiboui.  It 
is  DO  more  difficult  to  Mipj^ne  Ihnt  the  xiimulut' of  ihe  cnlnrpcnient  of  a 
Grasflui  folliele  chufcb  nutritive  as  well  as  vuscular  chtmges  in  lh«  uterine 
mooona  iDemhraue,  iban  it  is  to  suppose  ihnt  the  stimulua  of  food  in  the 
alimentary  canal  i-auav  tboce  uuirilive  changes  in  the  Mlivary  Klund*  or 
paucrea*  nbieb  couslilule  fecrelii>n.  In  ihe  laller  ease  we  ciui  (n  r-uine 
extent  Inire  out  live  chain  of  events;  in  the  former  caee  we  bariily  know 
more  than  that  ihe  miiinttnHnce  of  the  lumbar  coid  is  tudicieui,  nn  far  na 
the  ceuiral  nervous  Hvalcni  ia  concerned,  for  tbe  carrying  on  of  ihe  work. 
In  the  cB*e  of  a  d<i^  in  which  tbe  ejiinal  curd  had  been  completely  divided 
in  cbe  dotml  tegi4>n  while  t  ho  animal  wmk  a*  yei  a  mere  puppy,  "beat' 
or  mcnatniation   look  place  as  iivual. 


CHAPTER  III. 


IMPEEOSATIOX. 


Ik  onitus  the  iJiR-linrge  of  tho  eonipn  coiilnining  ibe  spermxtoioa  U  idmI 
probabtr  eRocloil  by  mi-iinH  of  iIiq  perislultic  coo (racl ions  of  ihp  vtncala 
Mini  inn  les  nn<J  ritsn  ilcli-ivtitia.  UMiat**'!  by  rlifthmicnl  oHitraction!  of  tlw 
bulbu-caverDitiUS  tnusck'.  the  whole  being  a  redes  acl.  the  oenlre  of  which 
apjieiir-  to  be  in  the  lumbnr  apiual  cord.  In  the  do;  etDMStoo  of  Mmen  can 
l>e  brought  iibout  by  stiniulntion  of  the  gisas  peiiis  after  oomplet*  diviaua 
of  the  sptual  cord  in  the  dorMtl  rtgioD.  fhe  emtaetoo  uf  seuea  b  pracedcd 
by  All  erection  of  the  peiiig.  This  we  have  already  seen.  p.  274,  is  in  part  at 
ImuI  due  to  an  iacreased  vascular  supply  broujihl  about  by  nieans  of  lb» 
nervi  erigeotea :  it  is  iirobAble,  hourever,  tltat  the  coiidtiion  is  further  Mcurcil 
by  a  comproasion  of  the  efn-rent  veins  of  the  corpora  earenioM  bj  neaw  af 
amootli  muscular  tibres  prateni  in  tho^  boiliea.  The  aemcD  bttog  KoainJ 
into  the  female  or>;aiL.-.  which  are  ai  the  time  in  a  Male  of  tui^(«ao«aea  n- 
•ombling  lUo  erertioD  uf  the  iwiii*,  but  \na  marked,  ibo  «^<ermata8M  flail 
their  way  into  the  Fall<>|iian  tiitK^uixl  hf.rr  (protmbly  lu  il«  uppar  part) 
Come  in  contact  with  the  ovum.  In  Lhr  c-aiw  of  niiinc  aiiimaU  itnprwnaiiia 
tuny  lake  place  at  the  ovary  itM^lf.  The  piu«tiigc  of  the  vjHTRlRloiiua  u  miHl 
probably  effected  nwinly  by  ihuir  mvn  nhralilc  nctirity :  but  in  •orae  antnali 
a  retrograde  pfiri«tnltic  movement  IrnvelliDg  from  the  uterus  alou^  tbe  Fal- 
lopian tiibm  liiH  been  iibfcrved ;  this  might  aa&iat  in  brin;;inj;  the  semea  bi 
the  ovum,  but  innfmucb  sa  these  movementa  are  prvibably  pirls  of  the  act 
of  cniiuB  and  iniprcguatinn  may  W  deferred  till  some  time  after  that  event, 
no  Bnai  atreer  can  be  Intd  upon  them. 

A3  ttie  reeuU  of  the  iictioD  of  the  spermatoioa  on  the  ovum,  ibe  Inlur, 
liutcad  of  dying  as  wheu  impregnatiuu  fuib,  awakes  to  ^reat  nutriiin 
activity  accompanied  by  remarkublc  Diorpholo^oal  chaqgea;  it  enlarges  and 
develops  into  an  embryo, 

[Preccdini;  the  time  of  the  occurrence  of  the  entrance  of  tbe  apenaatOKNB 
into  the  ej^'g,  certain  anatomical  cbaiigea  have  l>eeu  observed  to  OOCiir,  wJ 
in  order  thoroughly  to  under^Iatid  these,  &s  well  as  the  chanim*  whlti 
follow  iu  tbe  ovum,  it  will  first  he  neccaiary  to  review  the  anatomy  of  tlie 

Tlie  ovule  is  a  minute  cell,  tlie  wall  bciti^  form«d  by  a  Mruolumlew,  traiw- 
]]ditpiit  membrane,  cnlted  tbe  tana  nrUiielih,  or  vileltiiic  menibnuti'.  ^VItUa 
thi*  i.i  the  yolk,  or  rilvlhiit.  wbieli  coiui^l*  of  n  graaular  wmi-Huid  mam, 
having  dUiipeiideil  in  it  a  iiuc/t^iu  or  ijfrminai  w^ida,  containiDS  a  niMMlu 
or  iirrminiil  spat.  The  genuiuBl  vesicle  c»R«i«t«  of  a  very  di^cate,  traas- 
jiaivni.  homogeneous  membrane,  which  enelons  a  fliit<l  nitb  granule^ 
and  MUtiieuded  in  it  an  eccentric  nucleolus  of  a  granular  and  librillated 
•Iniciurc. 

Previous  to  the  occurrence  of  the  impregnation  of  tbe  ovule  a  very  ia- 
t'-renting  seriua  of  changoi  linvc  been  obaorriKl  to  take  place.  Acoordinif  t" 
Itfllivtir,'  the  fini  iiiten»tiug  polot  to  be  noticed  is  the  migratioD  of  thr 

■wflt^iunarlyJoanalur  3illrnM«op)-,<irtiit>:>t.  wc 


IMPREGNATION. 


IK)1 


gwratinsl  vesicle  towani  l)i<?  cell  nnll.  Tbti  vcsiciilur  wnll  (h«n  beooiuea 
mvj  aiiJ  K'^""'!)'  UUujigtearA,  while  iil  the  uuav  tiuio  iho  tiiiclMlua  or 
gM-ntlDBl  ipuL  bas  UDdargoue  iiietaiinirplKiti),  <o  that  whiit  ramnins  or  tbrne 
Nruc4ur<*  u  a  spindle  aluiped  maw.  One  cKtrvmit)-  of  this  nuM  fcrniljally 
prnjcoU  tlirougb  the  nil  wall  nDil  ii  thmwn  nfTiu  a  potur  ivxieU.  Frum  the 
olh«r  ranainiiix  j>i>rLioii  a  lecond  |>»lar  rueiclu  is  forniocl.  th«  pnrt  of  the 
mnis  tbon  remiiiiiiujj;  in  the  uvulf  Ix-inj:  )ii-rmiiicnt.  luirl  m  calleil  the  hmtir 
pfwiMd«ttf.  Tho  iw>\i  dinugv  ol»orv<''l  i»  iliu  ti|>|H?nraiici<  ofa  xoDe,  of  radial 
Dtrifl)  anxiDd  itiu  iirimiiolriin  ami  iu  ii)i);rati<)n  lo  the  centre  nf  the  Cfi^.  The 
i>t)ernHitoz<iuD  ihcm  iteuutrato  tho  wall  iif  thii  ovule,  probably  ai  the  p(uut  of 
trie  formation  of  ihe  polar  vtriclnw.  Thr  tail  of  the  Hperniatozoun  beooma 
alMortx^l.  and  the  bcai)  u  motaniorphotec)  intu  the  male  piVHUie/etut.  Fram 
the  mnle  prunueleiiK  a  niiniber  of  nMialine  Rtriie  arv  glvtat  off  in  all  dirco- 
tion»,  itnd  it  tlivD  migrates  toward  iho  fflinala  proiiuoleus.  and  aflcrwanl  ftuM 
with  it,  forming  n  single  or  c/mn-uyf  nufiem. 

Cloaragc  or  segmentation  of  the  viielliia  then  begins  ( Fig.  2701,  by  whidi 
prooeos  the  niicleui  thus  forniDil  divides  iatu  iwo  pur(«,  eaeh  taking  with  it 


Fla.n«l 


I 


l^i  Bl 


intoKUM  or  ni  Vtuou*  Biu.a  or  ciJuvAiit  ur  nit  Y«U.   i&Rer  DtLna-j 

liair  uf  lh«  vit«Uin(!  (iiiiMa.  Tbeie  two  divide  into  fuar,  and  thene  four  into 
eight,  and  »>  on  indi^liaitelv  until  au  ag^Itinierate  mass  of  uuelttaled  cells 
rewlto,  oocb  of  which  euotaiiu  a  yt^n  of  the  oIeavag«  uuoleuH.  Tltia  maw 
of  celb  is  called  the  mulberry  iuom.  and  the  rain 
OMutituiint>  it  arrange  theinntlvea  aifkut  the  ioierior 
of  lh«  (U'i'i  fttlliiridii  and  furin  the  blntlodenaie  ttsieie 
or  m^mhran'r.  Thifi  inrnihrauc  then  BpliU  up  into 
two  laverri.  llie  cxteni.il  stiil  internal ;  a  third  ur  middle 
layer  iieiiij;  nllerward  forinwi  lu'twcvn  iheiu. 

Iniui«<liiitv1y  after  the  furmiUtnii  i)f  the  two  lay«r» 
of  UMtiMli'rfii.  Ml  opoqu*  roundiul  e»llectt>iu  uf  tuall 
oelkoocurn,  (.-ailed  the  nnea  ffefmat'itim  ur  embryonic 
Spot.  (Kig.  '^71. 1  This  epol  then  liouvnim  <>ltin|{iilul, 
vad  in  it*  luU',>iuidiaaI  axb  the  lint  trace  of  llie 
«fnl>ry»  apiicant  *a  a  fuint  line,  termed  lh«  primiltve 
trtter,  thu  being  in  the  inidsl  of  a  clear  oloDgat«d  duu> 
of  oallSi  (he  orta  peUtieidi,  which  is  itMlf  surrotinded 
bv  a  more  opaauo  wae. 

'  In  front  of  the  priuiilivt-  iraee  two  Pilil«  aw  formed 
from  which  a  groove  U  pr<doDged  Iwckirnrd  in  a  )in« 
with  Ihe  primitive  traoe.  Tlteae  folds  gnulually  rxtoad 
along  the  entire  length  of  (hi  gro.ive,  anil  f  jrm  the  Vimnit  4ar»aU*,  which. 
by  growing,  projeet  more  and  mir«  abjve  the  groove,  and,  gradiially  ap- 
proaching eocb  other,  ooaledce  and  enclcMO  thi?  neural  canal,  which  will 
AAerward  contain  the  oerebro-BpinsI  aiii.     At  abxit  th<-  same  inriod  eor- 


tai-«ue^~  III   )■   .   Aim 
Cuai)KK<i.ii>  •!   <■  r<inii«- 

n»0«ini  UM  ■MBCBflM- 

■tilra  or  aniliry«ale«pot, 
Uw  mn*    tmitmOk,  uul 


IMPnBOItATIOK. 

mpondini;  to  tbe  deveIo|)iiient  of  ibo  (lonBl  laminw  aiaiiliir  lamiia 
given  ofl*  IVont  the  under  surface  of  th«  blji«to(l«rni.  Thne  iiro  tlui  lam 
tUHlraltt,  wbk-li.  by  craduttlly  enlarging  nn<l  finally  L-imlcMing,  eitclow  At 
abdominal  cavitv.  I)ene«lb  the  Hoor  of  the  groove  alMve  di-scHbed  a  tMi- 
oale,  wliltisb  collection  of  cells  app«ara.  Tli»  is  (be  rhtrrda  dormtit  or  not* 
chord,  around  which  are  afterward  developed  lh«  bodies  and  pruonH*  vl 
tli«  vertebra. 

During  this  perKxl  other  cbang«8  have  also  taken  pttuv.  The  oepkalie 
and  ritudal  etiremitiea  bav«  become  flexed  and  form  tlie  cephalic  and  caniial 
fifx*iTf4:  and  the  einbrjro  hLm  being  <!urve<)  u|)OQ  itself  laierally.  the  vil«lliiw 
tour  appvnrv  i>i;paratrd  fn>in  it  by  a  connlrii'ti^iii.  Thbi  cijtiiitrirliou  gradl^ 
atlr  iDcmioing,  finiilly  MpanitM  the  rilelliiiu  niat»  as  a  vcnicn'Kr  body.U 
beme  ooimrctcil  with  tbe  l>ody  of  the  cnihryo  by  the  viiellitK^  (iucU  (jTvii. 
278.)    The  vninilur  btidy  thus  fonntd  w  tailed  tb^  wmMinU  vtMr.    Thi> 


l)tAV*»M>tnC  MCtVDI  MIOWIMU  TUK  UKMYMM  DI  *  MtMHAL  tMI  MI  K   Mut 

rmimvii  AUDiirTtav  <*i)»i.  mn  Tin  MuuiMXn  i>«'  tkr  Unti. 

TiMMBff*  npraxnipd  is  iliki  4l*(nin  vonaii-inl*  M  Uimi  ••■  Uiv  nnvttiili  ur  anvalf^U  di|  U 

Uw  hoaia  nntiTy<^  |ff«vhiiw  lu  ilie«i]«irtMiof  Uirallaiiuti:  r.  ilic  HUaw  ctHnloa :  ■>,  nu  iBoM  > 

m'.Xim  plM»  of  c«or<(gcncv  nt  ilie  uonlon  and  ranotlan  of  ike  fain  annlra,  a'tf.m  natum 

isaniaw»Uy«r:  c,lhi>  licailaiul  irontof  Uwmtrro,  raoti^Mnflli*  l«lMilUv- '. .  iir 

•Hul  uan:  i,t.  Uir  ili«>|il«  •IIibmimt  w^l  <»  »>  "PHr  *^  lomT  paf\'-  ■ 

MdUUmI  Tolclo :  rl.  Ibv  vlWillM  duel ;  ■.  tlH  Hllknlnla  M«n«rtnl  lo  arnlii  k'  i-iiti  im  iLaiiir 
Uon  til  Uw  rUsuuiUut  e*ii«l. 

at  first  comaiunicaiea  with  the  iiile*tina]  cavity,  but  as  <)evvlopiaeDi  pioenA 
tbe  duct  of  coinmttnimiion  Wcotuc*  cluscl,  and  the  voicU-  is  oierrly  Utachnl 
by  a  pcdiclt!,  and  finally  diimp]x-jira  alttigcther.  At  the  lirue  of  thn  iln«l«^ 
luent  of  the  bkiudvewcls,  vcMcIa  appear  on   itir  furl'nce  of  \'  ' ''ia  * 

vcnicle,  coRMtiluling  tliu  vattmlar  areit,  lb«  cbirf  vt^rctA  being  : 
ini-Henieria  iirtnrii-»  and  veiiw.     The  ve>ve!s  of  Ibe  V8i>ctilar  anu  ubtuib 
nutritive  niulerial    C(  nluincd  ailhin  the  vcmcIg  and  ctiuvcv  it  lu  (be  ttldMyi' 
Sot  ilN  suateQanou. 


rMPaBQNATIOX. 


993 


Sboftlv  afW  the  occurretK;^  of  the  oommeneeiDeut  of  tiia  formation  of  (be 
umbilical  %-«jricle,  double  f»l(l«,  furtneH  of  the  extertiul  iHVor  uf  the.  l)ln«tu- 
dttrm,  are  ^iviin  off  {nun  iho  cH^plialic  and  caudal  vxtrviuitiot  aud  Utcrally, 
wbioti  eurTi!  artiuiKl  iirer  ihc  doriinl  aiirfiK^o  of  cbo  embryo,  where  ibcy  iDiWt 
and  coalcwf,  and  their  point  of  junction  buonming  nb»or1>ocl,  form  the 
amuiotic  vavity.  (Fig*.  272.  273.  274.  «inl  'il^t.'i  The  outer  Wrr  at  th« 
full),  or  fabe  namiun,  graduxltr  os)Mind<  and  curers  tlio  whole  of  tbu  internal 


I 


fm.  m. 


riihiTt. 


f(, 


X 


■■\ 


f 

H      «,  otwrloii  wKL  villi.    Tlio  villi  arr  <li"Uii  u-  In  Uol  ileivlutml  (il  Il»>  |An  <<l  itw  rriiiriaii  b>  wlilck 

W    |k«  alUnKil*  It  tileiiiltng  :  Ihl*  purllmi  olltmsUIr  liMunui  Ihe  iilnoenta.    'i,  utaioc  tniiioiii  iholm) 

UT*n  lit  llw  amnion  ;  e.  uunloUc  cavity ;  •!,  11101111)11  of  Ibc  InmOuc,  ■bmrloc  lla  Miiiii(ii:Uan  wIlD 

tbc  nuiUlloil  uNlpttN  (.  uuiUllPal  (wd.'Iv ;  /,  tlluallnii  of   limn  auJ  nHwh.  9,  albiiUb^    lAflct 

Tairn  ut4  Boinuii.i 


I 


•urftce  of  th«  vitelliiu!  mwiibrMW,  which  it  uliimiitely  replucos ;  tbe  iuitcr 
Ufer,  or  true  amnion,  u  conlinuou*  wilh  tin-  skin  of  th«  embryo  nt  the 
UlubilicuB,  and  closely  envelops  it.  The  nmniotic  cavity  or  sac  ihua  Fumicd 
becomes  filled  with  the  liquor  ttninii.  which  gradimlly  iucreaws  in  utuintUy 
M  pregnancy  advaoooe,  up  to  about  tbi-  fifth  or  §ixth  ni<mtli,  wneu  tbo 
(jiinntiiy  gmiluKUy  decreases  up  to  tbe  time  of  Ubar. 


FH-ZM. 


ruKVM. 


rM. I?V— ln*u«AM M fKimuTtt  Bn.  (AAh  lui.nn).  •.imlriMMl<rBKh:Kamnliclc«Birlt)ri 
«.»lkuiol^ 

Fm.  sn— riKL'Niiiin>  Ens  witn  ALLurrow  >Euii.v  ivwruiK.  a,  Inaar  larrr  uf  ■•aiil<iuc  6M : 
k,  «UM  layer  u(  diuii .  r.  lutlW  olur*  Uio  KtoiiliiUr  (dU>  t»iu«  lu  coaUnl.  Tbe  allanlDt*  \t  mtm 
IwKUatlngtBimai  tbe  wMMaiHl  Inner  InjtBnnribcanuiinilc  foldi.  TliUII«un>.  whloh  reintMOU 
(Ml)  IM  uwlMlB  MkaBd  Uir  |aiM  ■likiii  rbem,  iboalil  be  oani|an.>-l  nlib  Pint.  matHlm.  Ib 
<iMi4i  will  tolMnid  llu  MnKRim  viomal  in  i>»«  MUk 

At  about  tbe  time  orthnc-nmuienonnMtnt  of  tfaederelopinentof  the  amnion 
N  new  orgnu,  tbv  itUaitoin.  aiiiivnnt  ah  h  pyriform  maw  of  c«lU  at  a  point  iin- 
niiNlintely  )uM(i>ri«>r  to  tho  vitdline  duct  and  projeolin^  throusb  the  aaine 
oj>«niu||c.'  (FiK-  -''■')    '^■■■<  mtwof  oi'Ilti  nndergow  npid  growth,  8;>reaidi]ig 

■;;( 


fiD-i 


IMPBRONATION. 


ilwir  hclvrccu  tli(>  true  iiuil  rnls«  Kmniiilic  foldi,  finallj  c(im|ile<ely  eoclumDjt 
tbe  ctnbrvo  nntl  amnion  <  Fij;.  -T6j,  bccDniiD)j;  M  the  name  tinw  uiljoiatd  to 
the  fniM  nniDioii,  wht-n  it  U  (Icvvlopcd  intu  the  Ime  cfmriou.     During  tW 

SroccM  nf  llic  develop mriit  <if  thi;  allniitoiN.  il  lias  Iwromo  vcn  vwcuIm-;  ll 
ret  there  aro  two  arlcritv  and  two  vcini),  altcrirnn)  aiif  of  iw)  Tcbw  diiik»- 
pear*.  Thcao  vcneU  coiirtitlilo  the  umbiliral  vritwl!?.  fomiitig  part  of  ihr 
umbilicn)  cord  nbiofa  oniDecIs  tbo  iillnnoiU  with  ihp  nnbr^o.  lluring  thr 
devclopiDpnl  of  the  Allniilniit  it  prc»rril»  thrrtr  distinct  nnatamical  uortMin*:  a 
portion  n  hich  bccnnirii  ron'trictrd  nif,  nit  il  wen?,  I'roiii  (he  ntt  anu  fbrna  iW 
urioary  blitddcr :  tbp  outer  portion  forms  the  cborion,  tbe  intvrinnliabc  |Dir- 
tiou  fomiiiiR  tile  iimbilicnl  cord. 

During  the  development  of  tbe  enihn,'o  up  to  tbta  titnc,  tbe  lir^  eluifioa 
waa  formed  by  villoeitiei  formed  on  tbe  ritellioe  membrane :  au<J  fulliiwinf 
that  by  villoeilies  developed  ii]K>n  tbe  false  amnion.  The  allantni'  then 
becoming  developed,  completely  eovere  tbe  internal  eiirface  of  the  &1m 
aniDioD,  nbieh  tben  gmdually  disupwarB  as  a  dialiaet  itructure.  Th«(r«r 
ehorioti  is  ihen  formed  by  the  allantois,  which  becomes  cuvered  by  a  ^rmlii 
of  a  multitude  of  vascular  shaggy  tufts  or  villi  lFi(£.  277),    Theac  villi,  »t 


rif:T.l.—t>n\*»   Hi  HIM  (Vii  H  Df  li'.idit  Wiia,  ililMii   Ittna  til  kUKlli  iii»t  wUailic  IW 
tuflr>i  (bvmtlhM  of  Ibvrliuilndi  |<«nlr  ■ammli  niid  iHnli  mtdawt  •Iwoq  b^  I  lie  cnmlhi^  nSt 

FlQ.  fin— nMma*  or  hHk  op  tiiK  Kimi.  N'iili.  ■I>u»I  io  Innu  |«r1  iir  ikv  |'Un>nta.  IU(V)  au 
nllnA    n.SL  tUM'11ulkrnri<ilIiv-4&,''.«,  ilTlcAfiilrefMlf.  •■.•■.  lli  lH»li<ilnkniit>-ilir  tlw<r 

tint,  are  dtdlribulcd  over  tbe  entire  mrface  of  Ibe  organ,  but  lltvy  aoon  t*a>- 
nwnre  dJMppeanne,  except  at  a  small  area  eorrebpi-Ddin;;  to  tbe  nlUchiami 
of  the  pedicio  nbi^  eonnects  (he  allantois  wilb  the  embryo.  At  this  |i<»iii 
(bey  beenniv  gn-ally  Ini-reaMxl  in  nuiiitker,  and  also  in  size  and  viueularilr. 
Thr»c  villi  arc  cijnipi«cd  of  a  fibrograDular  mjilrix.  in  which  are  nucaenw 
cniiillary  loi)pii.  niid  arc  covered  with  a  laver  uf  vpiiht^lial  t-ells  (  Fig.  2iS' 
Tliis  I'ortifiu  uf  the  cburioti  forms  tbe  fcelnf  portion  of  tbe  placvain. 


tVPREOVATlON. 


No  MMXh'r,  howctCTt  IWTa  itivm-  cliiiQ',;(w  Itei^iin  iti  thf  oriim  thnn  ourrela- 

tiv<  ob>Dg(».  brought  kboul  iiroWblr  by  rrHcx  action,  but  at  prmeol  most 

I  ofawnro  En  ihtir  cauMtion,  mkc  plnm  hi  the  iKcnH.    Thci  raucous  inembnuie 

of  thii  organ,  whether  lh«  coittis  mulling  iii  impre)itiati')ii  \k  coiaciileni 

with  a  m«nslrtial  (wrioH  or  Dot,  becomes  coug(St«<l,  an<t  n  rapid  };ruwth  takes 

fibtfr,  churHctcriM-il  bv  a  rnpii)  proliferation  of  the  epilbelial  nnd  subcpilbe- 
inl  iHHUcs.  Unlike  the  ciiee  of  nwnHlriintiou,  however,  this  new  (;rowih  iloett 
not  give  irar  to  imnieiliiile  dccny  and  b.viiiorrba^e.  bill  rcmaias,  aiid  luav  be 
di«tiogiii«li«a  as  n  dcw  temporary  liciiitg  lo  the  uirnie.  the  »o-called  decidua. 
Into  this  decidua  iho  oviini,  oii  its  dccoent  from  lti«  Fallopian  tube,  in  which 
it  baa  undergone  d^velopoienlal  thaDgta.  extending  most  probably  m  far.  ill 
least,  as  tlie  f'orntaliou  of  the  blastoderm,  if  not  further,  id  received ;  luitl  in 
tlii»  it  bet-oaiet)  imbedded,  the  new  growth  cloeiog  in  over  it.  (Fij{s.  27!',  2>*l>.) 
H«aiiwbi1e  the  k61  at  tlie  uterine  Htnictnr^,  i^i|iecially  the  muacular  tisMiie, 
become  alw^  niuib  enlar^eil ;  od  prc-u;niiucy  iidvaiicett  a  lar^  uuml>er  of  new 
mnacular  libreu  are  formed.  Aa  iLl'  »vum  i-ouiinuea  to  inoreaw  in  alw,  it 
bulgea  iDto  the  cnrily  of  the  uteruii,  carrying  nitli  it  llie  (lortioa  of  Uw 


wut.  zn. 


RI1.3M. 


h 


» 


IM,m— Ptan'  trioK  or  tkk  ronaAiiiiN  ui  ina  Uniur*  Retilia  laurxu  nit  oii'v. 
Fto-Mt-Hiiaa  AirtiMati  i^m*  nr  t>nniii:«  ItEnau, 

<lrct<liia  which  luu  closed  over  it.  Honcrforwanl,  accortlinzl]^.  a  dirtinctiun 
is  madt'  iu  the  now  welldevclopMl  dccidnn  bdvrcvD  ttin  rtMiiiw  rrttrxn.or 
thai  part  of  the  uiembraue  whii-h  covers  the  projecting  ovum,  and  the 
deddua  nrrn,  or  the  re*t  of  the  membrane  lining  thv  nivity  of  the  uterus, 
the  two  being  cuntinuoua  around  the  bam  of  the  projecting  ovum.  That  jmrt 
of  tlie  deciilua  which  iiit«rvene«  between  the  ovum  and  the  nearest  iitOTin« 
wall  is  frei|u«ntly  spiiken  of  aj<  ihe  litfidiia  wrntina.  .\»  the  nviitn  developa 
■Dio  tlie  fu.-iuit  Willi  its  menibraiiea,  tbe  decidua  reHexa  Iwcumea  pushed 
agaiuitt  tbe  dei-idua  vera;  about  the  end  of  tbe  Ibini  uMuth.  in  the  ailiuan 
subject,  tlie  two  come  int«>  complete  contact  all  over,  and  ultimately  tlie  dis- 
tinction bt-twern  them  U  loet.  In  the  rei;iou  of  tbe  decidua  serotioa,  the 
allaiitoie  \i-e»<i--lii  nf  the  fortua  tievelop  a  placenta. 

In  the  cariicM  ntnjpv  of  tlie  ()evelo]>iueDt  of  the  placenta,  the  delicaie 
tiIImu  pruooMoi  of  tlii>  oburion  insinuate  ihentielvM  into  tbe  hypertropbieil 
follkkw  of  the  decidua  Mnitina.  The  villi  thtni  un(l<^r'„'»  a  rapid  incretue  iu 
•lie  and  va»rtilanty,  Ix^miiug  branched  into  Mtcnnilary  and  lertiarv  rnmifica- 
tiooa ;  while,  at  th<-  tame  time,  corroipuiiding  ehnnfct*"  ore  taking  place  in  the 
follick*,  by  which  tlicy  Iwcomc  greatly  iucrcA-wi]  iu  »\ix  ami  vasctiluHly,  and 
al  the  HUiie  time  forming  diverticula  in  which  an'  irnilH-ildei)  the  mniiRcaiion^ 
of  the  villi.  The  villi  and  fullicl*-*  thui  grow  liiiiuliaueouily,  and  finally 
I>e0(>ine  blended  with  each  uther  and  an-  im  hmgrr  frparate  sinictnrM.  Tbe 
fcliii-ular  bloodvcewla  lirM  form  cagiillary  plexuM^ ;  the!«  veawla,  howevar. 


996 


IHPRBONATIOK. 


Iwcouie  ea\»i^ed,  fortuiDz  frei^ucnt  nniwhiiiiixteti.  nod  Knally  conlwHni  to 
form  ivnotu  Miiitm  ( Pig.  iHl ),  m  nhicli  nrc  Imthml  the  ftvul  villi.     There  U 


Vl'..  »\ 


AscTMM  lit  A  MMiDxar  *  FrLi.r  Kohhli-  ri.i<  ir»T*.  Hiik  iiii-  i«fi«(  tlw  atcnw  (a  ■h»«ab 
lIienin)MalT«B»l>:  .1.  li.  rutllnc  iir1crl»  i>r  lb*  uwrii*. 


nocoutiiiuity  e«liil)li»lied  heiwe«a  tb«  mnliiriial  and  fcuu]  blood;  tbe  laWf 
rhangQ  of  nutritive  inat«riul  iteoeftutrv  fur  thi*  er'iwtli  and  developmeiit  l( 
ibv  &!twf  tnkiT  pliicc  llie  dcilinilu  nnfu  »r  tlic  villi.] 

For  further  account  of  the  vnrioii*  clmtiee*  bv  which  thme  efenu  tn 
hraaght  nl>oii[.  if  well  ii9  of  the  hinlorv  of  Ihc  eriibrvo  ilwlf,  we  rutut  refer 
the  reader  to  ntiaiomica]  iKHtiMW. 


DvKi.vo  tbc  ilcvttlopni^nl  of  the  chick  wilhin  the  hcnV  egg  lb^^  miiritiv« 
tnaicriul  needed  fur  tlii^  grovrlh  fini  of  the  bltutotkriD,  nod  njb«e'|u«-ntl]r  of 
the  ecnbryo,  is  supplied  bv  the  ridk.  while  the  oxjnu  of  thi-  iiir  piimiog 
ttw\y  through  the  |ior<iiie  shell,  gnios  aecrm  to  all  toe  liwiKv  tKiiti  of  the 
cmbryu  uid  yolk,  either  dircclly  or  by  the  iotervenlion  of  Ihv  uUnDioic  vo- 
s^s.  The  nnuaiDaiiiut  embryo,  during  the  period  which  pivm)<.«  the  •xton* 
sion  of  the  atlnntoie  vewcis  into  the  cxviliea  of  the  uterine  wnlls  tA  fnnn  tho 
pltic«iiM,  ni<|]>t  be  nourished  by  direct  diffusion,  linl  from  the  cont«iiI>  of  thft 
rRllopiaa  tube  and  subsequently  from  the  deuidun  ;  and  its  supply  of  oxygvD 
iDint  oomc  from  Ihe  same  sdurcM^.  All  aiinlo^  would  leftd  us  to  suppose 
thai,  from  the  very  first,  uxidtilinn  is  gatog  on  in  the  blasloderniic  an<l  cm- 
bryooic  structures ;  but  the  urnount  af  oxygen  aotUftlly  wilhdmviii  from 
without  is  probably  BXc«e«liDf{ly  small  in  the  early  8laKc:°,  seeing  that  nearly 
ibe  wlHfle  onerey  of  the  metalwlism  going  on  is  directed  to  the  buililing  up 
of  structures,  the  cxjieuditure  of  euerg}'  m  the  fiirni  i)f  either  heat  or  eitet^ 
ual  work  btiuK  exireiuely  small.  The  markei)  iiicn-'atte  of  bulk  wliich  lakets 
pjftoe  durini;  the  (.■ouvcmioii  of  the  luulbcrry  maw  into  thL'  hliuttudermic 
vwkle, ahovis  that  at  this epuch  a  n-laiivtly  speaking  lai^  quaulity  of  vraier 
at  leoAt.  and  probably  of  uiilritive  mativr.  niu.it  pan  flrom  without  into  the 
ovum :  and  nutiM'iiu cutty,  though  the  bluslnilvrm  and  embiyn  may  for  ihime 
time  draw  ihr  ninterial  for  tlieir  continued  ponstnietion  at  lint  hand  fruni 
the  yolk-Mc  or  umhilicml  vmtcic,  both  this  and  ihcy  ctmtinur  prohahty  until 
the  idlantoiit  is  formcil  to  rr wive  frwb  malarial  frwm  the  niothrr  by  dirvct 
tlittusion. 

As  (he  thin-vrallerf  nllnjitoie  vesm-ls  come  into  doer  and  fuller  connNlioo 
with  the  maternal  uterine  siuiises,  until  at  Inst  in  tho  fully  formed  plarenta 
the  former  arv  freely  bathed  in  the  blood  streaming  through  ihi;  latltr,  th« 
nutrition  of  tho  eiubryo  becomes  more  and  more  cnnlinctf  to  this  tpKial 
channel.  The  blood  of  the  fattus  Hovring  along  the  umbilical  artMioa  aUbol* 
exebanges  with  tlie  venous  blood  of  the  mother,  and  leaves  tho  placenta  by 
the  umbilieal  vein  richer  in  oxygen  and  uuiritivc  material  lu^l  jioorer  in 
oarboDic  acid  and  excretory  products  than  when  it  iasued  fr»m  the  fo4us. 

As  far  as  the  gain  of  oxy^o  and  the  loss  of  carbonic  acid  are  concenml 
tbeae  are  the  results  of  simple  diffusion.  Venous  blooil,  as  we  have  slniidy 
■etn,  always  contains  a  (luantily  of  oxy-hiemoglobin,  and  the  i(uantity  of  this 
sub«lance  prcMni  in  the  blood  of  the  uterine  veinit  is  sufficjeot  to  supply  all 
tlie  oxygeu  that  the  embryo  ueetls ;  the  blood  of  the  fetua,  containuig  teas 
oxygen  than  even  the  veuoua  blond  of  the  niutfaer,  will  take  up  a  cerinin 
ttioui;h  small  quautity.  The  fietal  blood  iFavelltnf;  in  tho  uubiliotl  artery 
must,  in  proporlibu  u>  the  extent  of  the  nutritive  chanoea  goiBg  on  in  the 
cuhryo,  powea*  a  higher  carbonic  ten*iou  than  tlial  in  the  nmbilical  rain  or 
uterine  nnuit;  and  br  dilTunon  gel*  rid  uf  ihi«  lurplua  during  its  stay  in  th« 
pliuvnta.  Tlte  blowi  in  the  umbilical  arteries  and  veins  i«,  therefore,  r«lB- 
tivelv  tjwakingi  venous  and  arterial  rr!i|Hrctively.  though  the  simill  exrun  of 
uxj-AMlogloblD  in  Uie  bUxKl  of  the  umbilical  voin  is  luiufildeiil  to  give  it  it 
dhtlnctly  aiurial  oQlor,  or  to  diftinguish  it  a*  sharply  from  tlie  more  wnoua 


: 


MS 


THX   KITTRITIOX   OP  TBK    KHUItTU. 


tilood  of  the  iimbilirnl  artery,  u  u  nrdimn'  arterial  from  ordinair  . 
blood.  TbuB,  the  ra>lu»  breathes  by  tneans  of  the  maternal  hlikod.  in 
aaine  war  that  a  fieli  breathe*  t>r  menR<>  iif  the  water  in  which  U  dwells. 

The  blood  of  the  fietus  w  very  ])oor  in  biemo|{lobiii  cormpondioe  lo  iti 
low  oxjffiu  coaftumplioii.  Wlieii  the  mother  'm  a>iihyxiiiled.  the  Iietiu  ii 
■Hphyxiated  too.  the  oxygen  of  the  latter  paffiiag  Iraek  u;,iiin  into  the  blood 
of  the  former;  aiid  the  a«nhysia  thus  produoetl  in  ilie  fotue  ii  taiich  moi« 
rapid  thau  that  which  results  when  the  oxy^.'en  U  u^'<d  up  by  tht^  tianciar 
the  fwtua  alotie,  ok  when  the  iiuibilicns  is  Itjtulured  and  the  fa-tii;^  ni>i  allowad 
in  breathe. 

If  oxytfcti  a»d  carbonic  acid  thus  pa^  by  difliuiou  to  and  from  the  raiAhir 
nnd  the  ht-tuf,  one  uii^'ht  fnirlv  expect  that  ilitTuaihk-  »ilu.  jmiti^ida.  and  cv- 
bobydratea  wuuld  be  conveyeil  tu  the  latter,  aiid  dilfuniblr  rxcn^^ton*  tarrinl 
away  to  the  formur,  in  the  uime  way  :  and  if  fatM  ■■an  pniv  ilin>c<ly  tiif*  ibr 
portal  blood  durinK  ordinary  dif^tion,  tjicn;  can  Im:  no  mwoii  fiir  doiihtii^ 
that  this  chiM  of  fdOil-stiiflii  alNo  would  fin<l  it*  way  to  the  fii'tus  ttimugb  llir 
placrnlal  etmclurti*.  We  du  Icuow  fnmi  cxperintcnl  that  diHiifililo  tulMlaam 
will  jHMi  both  from  the  mother  to  the  frUiK.  niiil  from  the  Iwtits  tu  thr 
mother ;  but  we  have  no  delinilc.  kaowleilgv  w  to  the  exact  fumi  anil  raaoDir 
ill  which,  during  nnrmal  intru-nU'rine  lif<;,  nutritive  miiteriaU  an-  convwyH 
to  or  cxcrelioiw  loiivrvfd  fnini  the  grnwing  young.  The  placenta  is  remark- 
able for  the  great  development  of  cclliitar  slnicLiirw,  apjiArenily  of  an  c|n- 
thelial  DaUire,oii  the  border-Intid  hoiween  the  maternal  and  fa-tal  eleiunlf; 
and  it  baa  been  aug(n:»t.cd  that  cbcac  form  n  temporary'  digestive  and  secrtfocy 
(excretory)  organ.  But  we  have  no  exact  knowledge  of  what  actually  doei 
lake  place  in  theee  atructuree.  From  the  cotyledons  of  niiuiiiaiiid  iiur  ht 
obtained  a  while  creamy-looking  fluid,  which  from  maov  ftaiurva  o^  lli 
obeniicid  compcaition  might  be  almiMt  npuken  of  at  a  "  utcnne  milk." 

Bnmking  broadly,  the  fcetus  liree  on  the  blood  of  it<  fflother,  very  mucb 
in  the  »awo  way  an  nil  the  tJttoue  of  any  animal  live  oo  the  blood  of  th( 
Imdr  of  which  ihey  are  ll)«  |mrt«. 

For  a  long  lime  all  tlie  euiDryouie  tiMuet  arp  "  protoplasnio  "  io  cbanelir: 
that  u.  the  gradually  difTtrbtiliating  vlemeiiU  of  the  Mveml  tiaauea  reiaaia 
still  embedded,  ao  to  speak,  in  undif&rvniiated  |irotoi>la«m ;  and  during  tlut 
period  ibcre  mu«t  be  a  gvnerid  nniilarity  in  the  mctabolUm  going  oti  id  rari- 
out  part«  of  the  body.  As  iIiir<Tcniiation  bocom«  more  and  more  tnarkad, 
it  obviously  would  be  an  economical  advantage  tor  partially  elaborated  mai^ 
rial  to  be  stored  up  in  various  tintal  li»u«»,  so  as  to  he  rendv  for  immecUHi 
lue  when  a  demand  arose  for  it,  rather  than  for  a  apacinl  call  to  be  made  U 
cadi  occasion  upon  the  mother  for  compamtively  raw  material  iwediog  nk- 
sequent  preparatory  changes.  .Avci^nlingly.  we  And  the  tinaee  (^  the  (mat 
at  a  very  eurly  ]ieriod  lundi^l  with  glycogrn.  The  miiKlee  are  eapecially  tiA 
iu  tbiB  :9tiii9tanoe,  but  it  ocL'ur^  in  other  tissues  as  well.  The  abundance  of  11 
in  the  fornter  may  be  explained  partly  by  the  fact  thai  they  form  a  vm 
iArge  proportioa  of  tlic  total  nin^  of  the  festal  body,  and  partly  by  the  ba 
that,  white  during  the  praaence  of  the  glycogen  ihoy  contain  mucli  undirter- 
eutiat«d  pnxoplasui.  tney  are  exactly  the  organs  which  will  ultimalelj 
tindergoa  largeamount  of  dilferontiation.  aDd.lberefire,  need  a  largvamuott 
of  material  for  the  motaholUm  which  the  diirerenltation  entails.  It  i«  nnl 
iiutil  the  later  Mages  of  intra-iilennt'  life,  at  about  the  lifth  moiilh,  whniil 
i»  larmly  diwippearing  from  the  musclot,  that  the  glyi^^'i.'en  itogiii*  to  tw 
depnaitea  in  the  liver.  Ity  thid  time  bUloloncal  diflhrentiatioti  hax  advaiUMl 
lar^ly,  and  tin-  u*e  of  the  glycogen  to  ine  economy  luis  1iu<h>iii[>  that  to 
whicfa  it  ix  put  in  the  ordiuar;'  life  of  the  animal ;  hvniv,  ne  liud  it  ilejuMilvl 
in  the  iMial  place.    BeKtdej  being  pr«ai-nl  in  tlif  fuMal.  glycugen  is  found  ^ 


TUK  NUTRITION  OK  TUK  KUMBYO. 


»mi 


I 

I 


in  ihij  |>Iiicvntnl  stniuiiit'cs:  but  here  pnihiiblr  it  k  of  qbc,  not  fur  th«  fetii>>, 
b(il  for  tlio  nutrUioi]  und  f^rou'th  of  ibc  pliicoiilnl  HtniL'turos  lhftiii»elv«t.  W« 
do  not  knoH'  Uow  much  t'arbohydratp  uiiiterial  (iod?  its  way  inin  th«  umbilical 
Teiii :  Slid  we  cannot,  thcrclbre,  »tate  wlial  is  the  source  of  the  lislul  f;ly<.'ug«n  ; 
but  it  it  ul  Unat  pi)Mibl«,  not  to  sav  pr>)l>nble,  that  it  arises,  in  part  ai  all 
eveois,  from  a  splitting  tip  of  pmeifl  mitterial. 

L'oDccrfiing  th«  riw  and  development  of  the  fuoclioDitl  activities  of  th« 
eiubryu,  our  iiuuwledi^  in  abuost  a  blank.  We  know  ecarcelr  aavthtug 
about  the  variouB  steps  by  which  the  (trimary  fuudaniuuial  <|ualttie«  of  the 
[>nit(>|>|jisiii  of  the  ovum  ure  dilfureutiuted  into  the  complex  phenomena  which 
w«  have  iittempte*)  in  lhi»  book  to  expound.  We  can  hardly  slate  more 
than  that  uhile  tuuscular  contractility  buconiea  early  d«velupecl,  and  die 
heart  probably,  as  in  the  chiuk.  heaU  even  before  the  bhiod-corpuselea  ar« 
formed,  loovementa  of  the  fo.-tuA  do  not,  iu  the  human  subject,  become  pro- 
nounoed  until  uflvr  the  tiflh  muiith ;  I'roiu  that  ttuie  forward  tber  increase 
anil  NulMuqueiitly  become  very  marked.  They  are  <if^n  s[>okeu  of  a«  reflex 
in  i-Uaractur;  but  only  a  preoonoelrcd  btiu  would  [irevunt  ihein  fntm  being 
rrgiinim)  aa  lar^ly  niitomado.  The  digentive  fiinctioDii  are  uatumlly,  in 
tbe  nlxH-ncc  uf  all  fotnl  from  the  alimeutnry  cudbI,  in  al)Gyau<'(\  Though 
nvpHin  may  be  fiitnid  in  the  giiwtric  membmnc  nl  about  the  fixirlh  month,  il 
IS  doubtful  whether  n  truly  |N;]itii'  giuHric  juice  i-'  nccrtttwl  during  intra- 
nterine  life ;  Iryp'in  nppeiir*  in  the  |uiiicreiu  somewhat  later,  but  an  umyl- 
olylic  fcrnwnt  cnnnot  fw  obiaim-d  fn>m  that  urgiui  till  nftor  birth.  The  dato. 
hi.weTcr,  at  which  thi-w  »i'vcnil  fdrmcnts  make  their  itpixmriuico  in  the  em- 
bryo appcan  to  iliUbr  in  dilfcrcnt  animnU.  The  excretory  functions  of  the 
liver  nrv  developed  early,  and  about  the  third  month  bile  pi;;ment  and  bile 
salts  find  their  way  into  the  int«8line.  The  ijuantity  of  bile  wcreled  durini; 
inira-uterinc  life,  accumulates  in  the  inlostine  nnd  especially  in  the  rectum, 
formiutc.  tojrether  with  the  itnmller  secretion  of  the  rest  of  the  canal,  aixl 
•ome  d«^uamated  epitlielium.  ilie  so-called  me<^«nitiai.  Bile  aalla,  both  un- 
altered and  varioiitily  chaD;.-e<l,  the  usual  bUe  pigments,  and  cholestorin,  are 
all  pnseni  in  the  meeoiiium.  The  distinct  formation  of  btle  ti  au  indtcatioa 
that  (he  products  of  fmial  metaboliam  are  no  luUij^  wholly  carried  off  by 
l)i<^  matt-mal  circulation;  a»d  tu  tlie  excretory  function  uf  the  Uvur  thcrv 
are  now  luliled  tbow:  uf  the  akin  and  kidney.  The  substaaom  etcopUtg  by 
lh49>*  orgnns  liu<l  their  way  into  the  allantuhi  or  into  tlie  amnion,  aconrding 
tu  the  arninp-mi'jit  of  the  fecial  membrnnai  in  diflereul  cloMe*  of  un!tnal#  ; 
in  both  ibi-Bi-  tluidi  urea  or  allied  bmlie*  have  been  found  lui  wdl  as  the 
onlinary  nlinc  i.-oniilitne[iL->:  the  taller  may  ur  may  n'lt  have  been  aettially 
eecreten.  From  thx  allantoic  fluid  of  ruminants  the  body  allantoin  ha» 
t>een  obtainod,  and  human  and  other nniniolic  Huiilx  have  bren  found  to  oon- 
tnin  urea.  It  is  maintained  by  some,  honever,  ihnt  the  tluid  in  the  ■mnion 
is  wcrebn)  by  the  mother  nnd  that  benc«  the  eiibetanocs  prwcnl  in  it  am  of 
maternal  origin. 

About  the  middle  of  intra-ulcrine  life,  when  the  ftelal  clreulatiun  [Kig. 
*i92)  i*  in  AilI  developRienit,  the  blood  flowing  along  the  umbilical  vein  is 
carried  chiefly  by  the  ductus  veuneus  into  the  inferior  vena  cava  and  an  into 
the  right  auricle.  Thenoe  it  i»  directed  by  the  valve  of  Eustachius  through 
the  foramen  ovale  into  the  left  auricle.  pasMng  from  which  into  the  led  ren- 
triele  it  is  driven  into  the  aorta,  ['art  of  the  nmbilinki  Mood,  honever, 
instead  of  pa^itiK  dinx-tly  to  the  inferior  cava,  enteral  by  tli«  portal  vein  into 
tbe  beiMtic  eirculatinn.  from  which  il  returns  lo  the  inferior  cava  by  the 
bepiUic  veins.  Tlie  inferior  eava  aUu  contains  blood  coming  from  the  lower 
limhe  and  lower  trunk.  Hence  tbe  blond  which  tnMing  from  the  right 
aurtclc  into  the  Idl  auricle  through  the  fotviumi  ovale  i*  utMribuieil  by  the 


1000 


THE   SUTBITIOS  OF  THE   EVDBTO. 


]vi\  veiilTicle  through  the  aortic  nrch,  tltciiieh  chicllj  blood  comiDg  ilimt 
from  tlie  plncentn,  is  itl»o  blood  wliich  on  lit  way  Ironi  tbc  placenta  ki* 
paaeed  ihrniigh  Iho  liver  otid  blood  drmctl  fnim  the  timin  of  tb*  lomr 
part  ol*  the  body  of  tho  ftotun.  Tbo  blood  dncondin);  «!•  fivtnl  vODun  btood 
tnm  ibe  head  and  limbs  bv  Uh-  imponor  vcnn  mfn  dovs  iK>t  n>iii);I>'  «itb  thai 
of  th«  inferior  vena  cava.  !}iit  fnlU  tntu  the  right  ventricle,  rruni  which  it  ■ 
diseliarwd  ihr><ii);h  ihc  ducliiF  nrlcrimiis  <  ItoialU)  into  ll»e  norm.  iN-tit*  ih* 
arch,  whence  it  tlows  tiartly  to  ihc  lower  trunk  and  liinl>».  but  cbiclly  hi  Uir 
umbilical  arleri««  to  the  plarcntn,  A  smntl  qiiaoiity  only  of  ibr  cijutrni*  li 
th«  nKhl  ventricle  tinds  ile  nay  ititu  the  lungt^  Now  ihi-  bloud  wbi^i  c«am 
from  the  [daceoca  by  lfa«  nnibilical  vein  direct  into  (lie  ri(;hl  auricle  ia.  a*  ttr 
U  the  fdelua  ia  concerned,  arterial  blood  ;  aod  the  poniouuf  umbilical  hloei 


fHa.Vt 


:v 


\f  \f 


I,  (be  unbUlnii  mod.  mtKtuiiiu  ■>!  ili 
win  kwl  iwu  umlillml  *ii'  i  1l«v  l^' 

lli«  iilMiniU  ci^  1.  >■>«  ii'ii'  '  iIkMhi 

Inta  dim  bnuclin,  t«n  il.  4<  !'•  (k  •iiiintninl  tt 
IliE  llTvr,  inrl  oil*  il),  ibe  duriii*  vT-umnk.  urMik 
ralm  the  latrrka  *«a*  mn  if>);  *.  Um  |m«I 
vctu.  nluinlitji  tlu)  blood  A«M  UM  lnlnUDovMl 
iii>lIliii(wlitiUi«rlHhIhc|*<>'' '"-"''  >.  thirty 
/j        iinntlw .  ibpwntix' nf  Itr  t>l  -nlblfli 

•■  ftrrov  proccvfUDf  fivm  ^  lu  "  ..<  rttH  H 
lb*  loft  Ti'nlrlrlc;  Uid  htnol  Mlmmu  lb*  «nn 
Id  (III-  arvli  nl  Ibc  aona  ill),  to  Xm  dUUWM 
inniHKli  Ihc  bnodie*  (ittMoiT  bT  (tic ana  ti Oa 
IiMil  and  itpiiMRilmDitiM;  Ibf  arrow*  Uuif  II 
a'pr*»-iii  Djc-  mnm  ofibc  feJvod  ftnai  ite  >«< 
anij  iiiiiHi  riiinulUt*  Ibroucb  \br  ]ac«lu  •*< 
wibelstmii  teln"  In  lb-  ■'it^rt-^'  •-"•  •■«  iUt,ti> 
ilw  rlul'i  niirlcli!  i<i.  HI MlManiM 

IlimtUlll  Illli  n||hl  mill:      '       I  l<      II"    lAllUMMfl 

■rttlT  illil;  ]•.  Ibc  -IiiFlii*  ■rltrtii-u*.  vWtb  If 
l«an  liitsa  |icn|4:t  ttciUiiuiiIlon  -^  ■)>•  (•■InHatn 
unrrj;  (In- iifmn  al  ™cb  'i-l"'  •'■  ••' 

loH  iiiIUHirnrj- •n«l'.'«  rui  oir     1<  t 

knnit  Jii|[»  It"'  ilis«adlD«  aonii  .-.  i-  -wi^ 
•llililva  l«t"  <■"'  ri'iiiHua  ItiiuK.  (»■]  Ibas  ihloik 
liitcnial  UUa.  w  hkb  bnyoDr  <t»  i.i.iM^i.uUrua* 
(lU),  aii-1  Ti'lani  Ihc  liliio]  ■>  i  •«) 

lo  Ibo  I'lutnla.  Hiid  Ibvpii-  i-* 

■tv  noitlnafl  tobi  ibv  bvHK  •'ilivioliuai  tto 
■rmnit  n<  ibi>  trfaliialVin  ••!  Uiibc  i«ii«Ii  ■■■ 
llic  niluniot  iba  mvoot  UcBd  by  itwtWfc^ 
li'It'nnt  i-rnacnri.j 


which  irareraea  the  liver  probiihly  hi^es  "t  tbit  epoch  very  littbr  i.x; 
during  il»  iraiiail  throuith  that  gland,  the  liver  Iwing  at  tht»  |H-n.id  «  *"« 
excretory  rather  than  iiii  actively  melnbolic  orjjan.  Hcnei-  the  bhwd  of  i« 
inferior  vioa  cavil.  ihwiKh  mixed,  la  od  the  whole  arterial  blood;  ai»l  il  a 
thi«  blood  which  i«  wni  by  the  left  Tontricle  through  the  arch  of  the  nUia 
into  the  canrtid  and  tuboluvian  arteriea.  Thuit  the  bead  of  the  fastne  'u  \mi- 
vidofi  with  blocMl  cominaratiTelT  rich  in  oxygen.  The  blood  drtt-eiiiiiui*  fiMl 
Ihc  head  and  upper  limli*  by 'tbo  superior  vena  cava  ia  dieiincUy  v<Im«: 
and  thin  |>nf>ing  fmm  tbi^  right  v<niride  by  the  duclixs  aneriiiauii  b  ilrimi 
along  ili«  dwccnding  aorta,  and  together  with  BOme  of  the  blood  pnaKUj; 


THE   A'L'TRITIDK  OP   TRB   KHBRYO. 


1001 


I  U>e  left  vcniriek  touhi)  the  sortie  arch  falls  inlo  tbe  tinibilicnl  arleriM 
aad  80  reaelic«  ihe  pUceDtn.  The  fielal  circulaiinn  lh*D  i."  ta  amiiij,i;<l.  iliac 
while  Ihe  most  (ti^tinetl^  veDous  blood  is  drivi-n  hv  ihe  rifjht  venlrkle  back 
to  the  jtlacenlu  lo  be  uxyceoaleil,  the  luiuit  (lixiint-lly  UTUriiil  (hut  still  niixeil) 
blood  i^  driven  hy  ibe  left  veotnde  to  llii?  wrehrol  wlructurft*.  wliieh  have 
iDore  Dt«d  of  osyKi-ii  thnii  have  the  other  tiwiicM.  Cotitran-  to  what  lakw 
ptaee  afterward,  tJie  uurk  of  the  right  venirlt'le  i«  iii  the  fd'tu!)  ^Tcatcr  than 
thai  "f  Ihe  left;  and,  iiCd'Hin^lv,  ihat  greater  thiolcnrin  nf  tW  left  ven- 
tricular wall».  to  ch  anicteric  tic  of  the  adult,  dom  not  Ih-cviuci  iimrlced  until 
^clo•e  uiwu  t>iith. 
In  the  later  Hufcm  i>f  pregnane}'  the  mixture  i>f  the  various  kiocU  of  blood 
in  the  rieht  aiiriole  iiifrvaiu.it  jm-ptiralory  to  the  changea  taking  place  at 
birth.  But  during  thi!  wholi^  timrof  intni-iitcrine  life  tjiaainouulofcxygeti 
in  the  Moid  [ituoln^  fmni  tlu-  aortic  tirrh  to  the  medulla  oblongata  ia  outfi- 
cicut  to  prvveni  any  inapiralnrr  itiipiilM-a  being  orifiuatm)  in  the  medullary 
rtv^iiralory  cx-Hlre.  Thii^  during  the  whole  pcricxl  elapsing  betwwn  the  date 
uf  iIk  olrii'-liiral  mtahlinhint-nl.  or  rtUhrr  the  consequent  full  dGvelopmoiit  of 

tilii  irritability.  un<l  the  v.poeh  of  birtb,  remains  donnnnt ;  the  oxygvn  Rupply 
tf>  tb«'  pnilopltL-ni  of  it«  iierTe-cclli  is  never  brought  so  low  lu*  to  ml  going 
the  mpiralory  molecular  explosions.  As  soon,  however,  a^  the  iuiercourM 
b«t«een  tW  maleninl  and  umbilical  blood  ia  interrupted  by  separation  of 
the  plueenia  or  by  ligatiirf  of  the  umbilical  cord,  or  when,  as  by  the  death 
of  the  mother,  the  umbilical  blood  censes  to  be  replenished  with  oxygen  by 
the  malemal  blood,  or  when  in  any  other  way  blood  of  sufBcientlv  arterial 
aualitj  txnm*  to  find  its  way  by  the  left  veutricle  to  the  medulla  oblongata. 
IM  mpply  of  oxygen  in  the  respiratory  centre  sinks,  and  when  the  fall  has 
reachra  a  certain  point  an  impulse  of  inspinitiuH  ia  )tenerated  and  the  ftetus 
for  the  first  time  breathes.  This  action  of  llie  Kitjiirati^iry  ci-iilre  may  be 
•MlMed  bjr  adjuvant  impulws  reaching  thv  centrx>  alone  varioim  nflireut 
ncrvea,  auch  ua  thoae  started  by  exposure  of  the  body  to  ihi;  air,  or  to  ewld  : 
but  th<4«  are  oubordinnte.  not  i^vn'nlint.  A  retarded  fine  brentb  may  be 
hurried  on  by  dasliing  water  on  the  face  of  the  newborn  infant ;  but  on  the 
ollwr  hand,  the  fa-tus,  upon  tbs  ccmition  of  the  niacental  circulation,  will 
make  it»  lint  rtmiratory  moremcnts  nbilc  it  is  still  invesitil  with  the  intact 
membrane*  ao<l  thu«  sheltered  from  the  air  and  intleed  from  all  external 
stunuli. 

Before  this  first  bmilh  is  taken  the  pulmotinry  alveoli  contain  no  air,  and 
the  luo^  when  thrown  into  nnler  sink  at  once;  they  arc  then  said  to  be 
"  atalecUUic"  After  the  tint  breath,  the  alveidi  i-outain  air  and  the  lunga 
float  when  thrown  into  water.  A  striking  dillereiice.  however,  exists  hetweau 
the  lungs  uf  a  nenbom  infant  and  ihoee  of  an  older  petrvon.     When  tlie 

Sleural  cavity  of  the  former  is  opened.  Ihe  lungs  do  not  collapse,  no  air  is 
riven  out  by  the  trachea;  that  partial  dietendon  of  ibe  luugs, and  negative 
tboraciepreaaure,  apfiears  not  to  be  established  immediately  upon  Urth.  That 
porlioD  of  the  reuiiual  air  in  the  lungs  of  the  adult,  which  remaining  after 
the  mi»t  forcible  expiration,  is  Mill  driven  from  Ihe  lung*  u[>uu  the  pleural 
cavity  bdiig  laid  open,  and  which  might  be  called  "colla|Be  air."  is  wanting 
in  the  newlturn  infant.  When  the  change  from  uue  L'onditii>n  to  the  other 
is  eili-eted  in  not  at  present  known  :  it  may  puuibly  ariw  from  the  growth  of 
the  cheat  outMtripoing  lhat  of  the  lungv. 

When  the  lirsl  hn-alh  U  taken,  aa  iiuder  normal  circumidaucn  it  is,  wilii 
free  arcew  to  the  atmcxpbere,  the  \ttng*  become  lilk-d  with  air,  the  seantT 
supplv  of  MoihI  which  at  tlie  moment  was  |iM»iiig  from  ll>e  right  ventricle 
along  the  pulmonary  artery  returns  to  the  left  auricle  brighter  and  richer  in 
oxygen  than  ever  was  thv  ftrlal  blood  Iwfore.     With  the  diminniion  of  re- 


k 


1002 


THB  HCTBITIOK   OF  TBK   KMBRTO. 


MMUice  in  (he  pulmiiiiarT  cirviilalinii  Rniucil  1>y  lh«  cxpdiiiiiion  of  tbt  ibofit, 
u  lai]ger  ttipply  "f  h1ui)([  p«Mcw  inin  lliv  pulraonBry  Brtdrr  in»loiMl  nf  iaia 
tl>o  micUiis  arU-riwup,  anil  this  dorivnliuii  of  tli«  (.imtcntii  uf  Um>  ri^u  vrn- 
tricl«  iacrewiiug  wilh  lh«  coiitiiincd  mpiraLcir}-  mnvomcnU,  Uie  ourrrni 
Ihroueh  the  Inttcr  rniin]  Ht  Iwi  cckms  ulto^-tlicr,  nnd  ii»  cliannal  ibortlj 
mfmr  birili  bcconics  nhlitarnloij-     Currcaponding  tn  th?  greUor  flow  iuUi  tlir 
pulmonnri-  nriery.  »  lar^tir  mikI  Urgar  <|uaiilily  of  blixid  returns  fmin  ibr 
piilnionnrir-  vciii't  iiilo  l)ie  le)1  iiunclc.     At  the  Mine  limp  Uie  current  thnMifh 
the  diiclits  vciiomis  from  the  uinhilicnl  win  hsvio);  cnued.  the  flow  frqcu  ih 
inferior  earn  hue  HiiiiiiiUbeiJ :  and   tlif  bloml  of  the   richl  aurieic  findini 
litllc  re^istitnoo  in  l)i(>  ilirectioii  of  the  ventricle,  whieli   now   ivodily  di^ 
fhargra  tie  cdiiIodU  inli]  ihe  ptilniouary  artery,  but  fiixlin^-  in  lh«  lefl  auride, 
which  b  L'ouliniially  beii));  tilled  from  the  lungs,  an  nWacle  to  iu  MjMgc 
through  the  foramen  ovale,  wasea  to  take  that  course.     Anv  r«turo  of  blood 
from  the  now  vigorous  and  active  left  auricle  ialo  the  riglii  auricle  ta  pi»- 
vented  hy  the  valve  which,  during  the  latter  stages  of  iDtru-ulerine  life,  haa 
been  growing  up  in  the  left  auricle  over  the  foranieD  ovale.     At  binh  thi 
edge  of  this  valve  is  to  a  oertain  extent  free  so  that,  Ju  csae  of  au  emersieDCT, 
as  when  the  pulmonary  circulation  U  olutructed,  a  direct  wcape  nf  hhoi 
into  llie  left  auricle  from  the  over-burdenei)  ri)(ht  auricle  oan  take  pbm. 
Kveutually,  iu  the  (.-oiinv  of  the  6r>t  year,  adhraiou  talc<«  plaoo.  and  tbr 
Mjiaration  »f  the  two  uuricl<»  become*  cumpluh-.     \^'itli  it*  htrmr  supplr  «f 
blood  and  jtreater  work  tlie  left  vontride  acijuiret  the  greater  liiiclcDon  ebv- 
a«leri«ic  of  it  during  life.     Thin  tli<-  fn-tal  circulatiou,  in  coDMqiwaotoril» 
rM*{>initory  miivvmuiitv  ti>  wliich  il*  interruption  giv«i  riw,  cbuigtg  its       ~ 
into  that  diiiractemtic  i>f  the  adult. 


( 


CHAPTER   V. 


I 


PARTURITION. 

■pile  of  ihe  incrensifl^;  dialentioD  of  Jtfl  cavity,  iHe  ulenu  ramniilB 
quinoeni,  tut  far  an  nuy  lunrkeil  tnuHculiir  tuiiiraL'iionii  ure  iMiXM-meit,  uuiil 
K  <«rlttin  timt-  liits  been  run.  lo  tlie  humati  aai>ject  the  period  of  Ke^taltiiu 
gencrullr  ImW  from  'Si^  w  '280  days.  i'.  c,  abmit  40  weeks,  Uie  h'^ueral 
cuiOom  (leiiig  to  expect  parturition  at  about  'i-SO  davH  fr»m  the  latti  meiisitru- 
aiioii.  Seeing  ihmt  id  nuiii}-  vium  it  in  unci'rtaiii  wlieiber  lh<-  ovum  wliich 
develop*  into  the  embryo  [^{t  Ihu  ovary  at  llie  niL'tMlniation  prin'tnliiig  or 
•uoeeeaiog  ooltun,  or,  a*  itcime  have  iiruiuJ,  indopciidunt  of  mcu^tntatiou,  by 
nuon  of  tlic  roiluti  ilaetf,  un  exact  dcteriniiiaiioii  of  the  diinilinn  of  preg- 
nancy »  impomiblc. 

In  ifaeeoir  tlio  period  of  KMtatUin  la  ntiout  to  280  days,  in  the  mari'  aboiti  IVAt, 
•beep  about  IM  dny*.  dog  almut  >\''>  dnyn.  rabbit  about  no  dayi. 

The  extruBioit  of  the  fielus  U  brotixht  about,  partly  by  rhychmicnl  can- 
intctiona  of  the  ut«ru»  iUelf  and  partly  by  a  preiuurc  exerted  bv  the  coti- 
irootion  of  the  abdomiiul  mitmlea,  *imilar  M  that  deirribtii]  in  dcfecatina. 
The  conlrartionH  of  tlie  uteru«  are  the  Ant  to  apjiear.  and  their  fint  oRcct  \» 
lo  bring  about  a  ilitalinn  nftlieot  uteri  ;  it  ix  not  till  iho  latttrRtagv*  oriabi>r, 
while  the  fd-tus  i*  piu^ing  into  the  vagina,  that  the  nbdoninal  mnsclM  are 
brought  into  play. 

The  whole  (iroceee  of  parluritimi  may  be  broadly  considered  a  reflex  ayt, 
the  nervous  eeniri>  beiu^  pliiccd  in  the  lumbar  cord.  In  a  do;;,  whoae  dorul 
cord  bad  be«n  coiiiplelely  severed,  {Htrl urilioD  took  place  as  usual ;  and  (be 
Iket  that,  in  the  human  siibjei^t,  labor  will  progreoa  quite  naturally  while  the 
patient  is  unconscious  from  itie  ad  ruin  Ihi  ration  of  cbloraform,  shavs  that  in 
woman  also  the  whole  matter  is  an  involuntary  aoliun,  however  much  it  may 
be  aoaiued  by  direct  volltioDal  ellorts.  That  the  uterus  is  capable  of  being 
thrown  into  contractions  thniuuh  retlex  avtion.  excited  by  stimuli  applied  to 
various  aflereut  iierviH.  in  well-known.  The  oonlractioo  uf  the  uieriu,  which 
is  so  necf^tsary  for  the  prevention  of  lieiuorriiage  after  deliverv,  may  fnt- 
nni^tlr  be  bmught  about  by  exerting  prossttre  or  by  dashing  cofil  water  on 
tm  abdomen,  bv  the  introduoliuiu  of  foreign  bodies  into  the  vagina,  and  es- 
pecialiy  by  putting  the  child  to  Ihe  nipple.  And  we  learn  from  oxporimcnta 
on  animal«  that  rhythmio  iviniractioos  of  the  itterui,  n^Mnibling  at  Ictut  thnoe 
of  parturition,  may  I>a  brought  ahiKit  in  a  n;ll<;x  ntnnnrr  by  ftiniulating 
various  affereni  ocrviw.  Similar  movemenla  raay  be  induced  by  direct 
stimulation  of  the  »pinal  coni  along  its  whole  length,  as  well  as  of  varions 
parts  of  the  bniin;  but  thrrc  arc  rcowini  for  thinking  that  in  these  cawa  the 
impulses  starl4;d  in  the  brain  and  upper  part  of  the  spinal  <.-ord  praduoe  their 
flAola  by  working  upon  what  may  br  called  a  "  parluriliou  "  (^..-nlre  in  the 
Upper  bimbar  Fegioas  of  the  cord.  And  it  would  ajipaar  that  (he  uterine 
oontractionn  which  are  indtic«l  hy  such  drugs  as  ergot,  as  well  as  thoae  caused 
by  aapbyxia,  are,  at  all  events  in  |Mirl,  brought  about  by  (he  agency  of  Ihe 
tame  lumbar  centre.  From  thi<  centre  (he  path*  for  (he  cStren(  Impulses 
appear  (in  the  dog)  to  Ik  twofold  ;  one  along  syinpithetic  iracu,  by  nerve* 
passing  from  tite  inferior  mpsenteric  ganglion  to  tlte  hypogastric  plexus,  and 


1004 


PABTUItlTlON. 


tho  oihcr  iilou^  t<|iiTia1  tmctH  liy  Iirnnclieii  of  tUc  tncral  aervtB  ti>  tlic  ninr 
iil«xiJK.  Il  in  Kiiiletl  tliul  tlic  cliitrucien  of  tbo  luavemeuls  induwti  by  slimu- 
luting  iIicm:  two  traiTbi  lire  itniucwluit  ilifTurcui.aiiii  moreover  itial  tlie  synipa- 
Ui«LiL-  truc-t  in  vnnii-fiinstriclor  unit  (lit;  <[iiittil  tract  vowHlilator  iu  DMuk; 
bill  the  iimtli^r  huA  ddI  yi-t  \n\-n  fiillr  worked  oiit. 

Wu  nre,  however,  hiki-illy  jii«liHr<l  in  CDDxideriii^  tbe  rliylltmival  codUbc- 
tions  of  l.hv  ut<;ru»  during  jiarturilion  niiNn){ilc  nrlli-x  acU  excited  by  tbepft^ 
cncc  of  Uk-  fwluK.  Wr  lire  iillcrly  in  llic  durk  a»  lo  why  tho  uterus,  after  n- 
mBiiiine  npiinrciitly  perfectly  ()iiit.-sc%ni  (or  witli  cnntniclion*  m<  iltght  m  tn  b» 
with  dinic-iiily  n]>|>nTiiil*Hl)  for  months,  i"  »u<l<l*uly  thrown  into  ui-ti'iii,  akJ 
nilhin  it  miiy  In-  for  n  few  houm  or  even  Iww  g«U  rid  of  tbi-  biintni  il  bat 
borne  with  kucIi  ((ilirnnce  for  to  li.mg  »  time  ;  iiou*^  of  tlie  vuriuu.i  hy|x>tli^^M 
wliicli  hnve  bcTti  put  forwiirtl  caii  he  eun«idci'ed  id>  !aiti»lii<.-t(>ry.  Anil  uq^H 
we  know  what  8tnrii>  ihv  iietive  phiiee,  ne  shall  reinuin  ii>  ignoraiKV  of  the  ' 
exact  iniian«riii  wliicrh  llie  netiviiy  is  broiight  aboot.  The  pevtiliHr  rbyibmic 
character  of  the  c>'llt^leti<>n^  eaeh  "  piiiu  "  beginning  fn'bly.  rifling  to  m  BUx- 
imuni,  then  dcetiniug.  iind  lioiilly  dying  nwny  altogether,  to  bo  mioomuM 
after  n  pauee  by  a  similar  pain  just  liko  il«elf,  pain  following  pain  like  tiit 
tardy  long-drawn  beats  of  a  alowl y  beating  heart,  BUgg«tts  that  the  chun  *f 
the  rhythmie  contraction  ia  leated,  like  that  of  the  rhythmic  beat  of  Ik 
bearl.  iii  tlie  organ  it«clf.  And  this  view  is  8np|X)rted  by  the  lact  that  e«- 
tnctions  of  the  uterus  similar  to  thi»e  of  parturition  hare  been  observed  ia 
aoimalfi  even  al\er  cuinplete  daitructton  ot  the  »pinal  cor«l :  and  tlie  Btott- 
nieut^  induced  by  aitpliyxia  teem  iu  part,  and  those  cao^  by  sune  dn^ 
auch  aA  ammonia,  seem  lo  be  wliully  due  to  nn  inlrinBic  action  of  tbe  iit«n» 
il£elf.  Neveiheleaa,  general  evidence  aup|K>rta  (be  conduniun  that,  is  > 
normal  slate  of  things  at  all  erenta,  the  coniruetiuiia  nf  the  nt^nia.  liketluH 
of  tbu  lymph- hear  Is,  are  largely  dc|>i;ndc<nt  on  the  aplnnl  eord. 

Thir  occurrenoe  of  controctionN  in  eoRM'tiiienee  of  an  aAphyxiatnd  oDodilMi 
uf  the  btiiud  explaisa  why,  when  pregnant  luiimaU  are  tuphvxiaUK].  an  «!■ 
trusion  of  tbe  fcetu*  frequently  tnki?  pinec.  There  u  no  evjjenve,  bnwim. 
that  the  oiiact  of  labor  it,  aiuaod  by  n  gradual  diminution  uf  oxygeu  in  lb* 
blood,  n'nching  at  List  to  n  climax.  Nor  nre  there  HiHieii^ii  facta  to  oooiwi 
jwrturition  with  any  condition  uf  the  ovary  resembling  that  uf  lueiutraatH*. 

Tho  action  of  the  ahdominnl  miiseleif  in  parturition  i«,  on  the  otbtr  band, 
obviously  a  rellcx  net  carried  out  by  means  of  the  spinal  cord,  tlie  uvvamn 
stimulns  being  supplied  by  the  pressure  of  the  fcetus  in  the  vagina  or  by  tW 
contraction  of  the  uterus.  Uence  the  whol«  act  of  parturition  nuiy  with 
reason  l)c  eonxidered  as  a  rcHex  one. 

Whether  it  Ira  wholly  a  r«flex  or  partly  an  automatic  one,  (he  net  oa 
readily  be  inhibited  by  tbe  action  of  the  eenlral  uervmis  systeni.  Tbui 
emotions  ar«  a  ver^  freoue&t  cause  of  tbe  progress  of  pariuiitiou  beinx  ni- 
denly  stopped  ;  as  is  welt  knairo,  the  entrance  inln  the  bedroom  of  a  MnafH 
often  cau!«8  for  a  time  the  sudden  and  alwolute  ce^^atiuu  of  '*  labor"  paiaa, 
which  previouftlv  may  have  lieea  even  violent.  .Iud>;int;  from  tbe  aittlosy 
of  mieiuriiiuu,  Wwe«n  which  and  purturition  there  are  many  |toiiK*  d 
reaemblsnee,  we  may  8upiiiK>e  that  this  iuhibtlion  of  uterinv  (-ouiractioa*  I* 
brouffht  about  by  an  inhibition  of  the  centre  in  the  lumbar  cord. 

Aiier  tbe  expuUion  uf  the  lii^lni',  the  f<i-l»l  plair^mta  acparatea  from  ikt 
uterine  walln,  and  \»,  together  with  the  rcmnunta  of  the  luembruiu*.  cs)«Ual 
after  it.  Tbe  uteru*  then  fall*  into  a  lirm  tonic  oonliaclion  ainiilar  to  tte 
of  tbe  emptied  bladtler,  by  which  inirans  hKinorrhase  from  the  ^wwcU  Inra 
by  the  Mpataiion  of  tbe  placvutii  in  avoided.  The  Fining  incmbnuic  of  tha 
uterua  it  gradually  retitored,  [liv  mn»eular  elements  arv  reduced  by  a  n|ai 
Iktty  d^eoeratioa,  and  in  a  short  time  tbe  whole  organ  has  rclunied  to  iHt 
aormai  eonditton. 


J 


CHAPTEK    VI. 


THE  PHASES  OF  LIFE. 


I'he  child  bas  at  birth,  ou  nn  nvoraffp,  rmtber  leM  than  one-thinl  tbc  dux- 
iroum  length,  and  about  one-tweiiliclh  (bo  maximum  weight,  (o  which  in 
future  Tears  it  nill  nttain. 

Tb«  cttin|Miiitioii  of  the  body  of  the  newboi^  babe,  itf  compared  with  that 
of  the  adult,  will  be  seen  from  the  foUowiog  table,  in  which  the  details  are 
more  full  tlian  ihoie  f;<veu  on  p.  ii'ZH : 


Wllglit  of  ouii  In  peiTvnlur 

of  iKlilj-I'Vltht 


Era       .        .        .        .0.28  oi)2« 
Bnin    ....  14.34  2..^ 

KUmts  .0.88  0.48 

SUn     .       .  .  tlJ  8.3 

Li*w    ....    4.38  2.71 

lleitrl    ....    0.89  UjS2 
Stomach  and  intculine  .    2.S3  iM 

Lunpt  ....    S.16  101 

Skploton  .        .  Iti.T  tS.30 

>Iu»:)c»,  etc.  .  2.XA  43.1 

Testicle  .     ami  0.8 


WirtEbt  of  uniiin  In 

■it  nil,  u  oompftred 

wKb  mat  of  neotani 

tAtv  uivn  M  I- 


«n 


It  will  be  obeerved  that  the  brain  and  eyes  are.  relatively  to  the  whole 
iMilr-wetKhi,  very  much  lairer  in  the  babe  than  in  the  adult,  aa  b  also, 
though  t(>  a  leas  extent,  the  fiver.  This  disproportion  is  a  very  niurlced  em- 
bryonic ft*lure,  and,  aa  far  aa  the  brain  and  eye  are  cniiix-rned  at  least,  haa 
a  llK>T]>bolof[ical  or  phylojteoic,  aa  well  aa  a  phyaioloj^cal  or  teleol<<i;ieal.  aig- 
nificADce.  Inasmuch  aa  ibe  amaller  b'xly  haa  relatively  the  larji-er  niitfoce, 
ibe  akin  is  luiturully  prci|)ortioiiately  greatwr  in  the  Imbe. '  It  is  chiefly  by  the 
■ociimtilatiiui  of  muscle  or  flwh.  properly  so-called,  that  the  child  acotiirca 
the  Ittilk  and  wi'ight  uf  man.  the  skeletal  fraroewurk,  in  spite  of  ita  ncing 
■(wcilically  liifhlvr  in  its  earlier  cartiliiginous  »>ni)ition.  mainbuninj;  thrviugh- 
oiit  lift)  about  the  Mine  relative  weight. 

The  incn-*M<  in  stature  is  very  rapid  tn  curly  infancy,  proceeding,  ho««vef, 
by  dnn-asing  inerementM.  During  or  shortly  before  nunerty,  there  is  a^in 
a  KMntwhal  Ruilden  rise,  with  a  suli*ei|ucni  more  aieMy  bat  diminiiibing  in- 
crwa*  up  to  about  the  twenty -Rfth  year.  From  tlwnce  to  about  fifty  ytan 
of  age  the  hcjght  rcmaint  ntHtionary.  aft«r  which  th^rc  may  lx>  a  docTWM, 
eepecinllv  in  extn-niv  <ili)  ng<i. 

The  inrwwK-  in  weight  U  also  very  rnpiil  at  first,  and  proceeding,  like  the 
beif;ht.  with  itiiiiinl<bine  iDcr«nicnl>,  mar  eontindo  till  altmit  the  fortieth 
year,  .\flcr  the  *ixiictn  T«ir  a  decline  of  variable  e-xlent  i«  generolly  wit- 
neaani.  It  i^  a  remarkable  JVicl,  hunevtir.  thai  in  the  (irft  few  days  of  life, 
an  far  from  thrre  lieing  an  increaK-,  tWrv  i^  an  actual  dwrmsc  uf  wei];ht, 
so  that,  even  on  the  seventh  day  the  weight  riill  euntintiee  to  be  lea  than  at 
birth. 

The  saliva  of  the  babe  is  active  on  tinrch.and  tta  gastric  jmce,  unlike  that 


1006 


THK   PHASES  OF  hlTK. 


raai 

1 


uf  ninny  oewboni  aDimah,  hoa  t(ood  peplii?  powers,  fmm  whiirli  we  mny  iutrt 
UiAl  iu  iligottive  pr((C(w»  in  general  are  identical  witli  that  nf  the  a<luli; 
but  lh«  foots  of  lb<-  infant  contaiu,  beaidcs  owiniierable  quauliir  uf  iioili- 
mstod  f(M>d  (fat,  cnwiii,  etc.),  unaltered  bile-|>i(;iuenl,  and  utide(WiB|Kavd 
Dil«-«ttltfl. 

Tilt  hunrt  of  tlic  balw  («eo  Tabic.  |i.  1005) !»,  relatively  to  it*  body-«tjg)iu 
larger  tlinii  tbc  ndult,  niul  tlie  friijiient?}'  of  tite  bmrl-bcut  Riiicli  tffeaicr, 
vii.,  nliixit  nil  or  NO  per  miiiiilc,  fiiUiriK  In  nbmit  I  111  tn  tlii;  M^^ioa  ri«r. 
and  idimil  90  tn  ihc  tcntli  yimr.  Vonr^poniVing  tn  thv  smiiller  bulk  oi  tlia 
body,  the  wliiilv  circuit  of  the  blimd  nvFlom  i*  truvcrwti  in  a  i>hnrt«r  tiat 
than  in  the  adult  (12  »ccond#ne  ii};iiini>t  'i'^);  »nd.e"ii*r<jiieni]r.  thr-  natwal 
of  the  blooii  in  the  liwuc*  iicxccr.lingly  m|iid.  The  n-»pimti<>ii  of  ibt  bab* 
is  quicker  thiin  ihnl  of  the  ndiill.  King  at  first  nboiit  $'>  per  minitle,  fallii 
to  is  in  the  second  yenr,  to  it)  in  the  tilth  yenr.  and  to  onuard.  Tb« 
apimtory  Rork.  while  it  incrcnsee  aheotiilcly  as  the  body  grows,  is.  relati 
to  tfae  body-11  eight,  grcnicat  in  the  enrlier  yo^re.  It  is  worthy  of  iMtice 
tbe  abeorplinn  of  oxygen  is  snid  to  be  relatively  more  active  than  tbe 
duolioB  of  carbonic  acid  :  ihni  is  to  say.  there  ib  n  continued  acvuniuUJiaa 
of  capital  ill  tbe  form  of  a  store  of  oxyKen-holdinR  explosive  ooinpuuiKb 
(•ee  p.  472).  This,  indeed,  is  tbe  Btrikioj;  feature  o(  infant  meiabolisn.  It 
i«  a  nietabolisiu  directed  largely  In  constructive  ends.  The  food  taken  repR- 
tents,  uiidoubt«dly.  so  mucn  potential  energy;  hut  before  that  euerKy  ou 
aiHunie  n  vitid  mode,  the  food  iiiuat  Ite  convened  into  limue;  and,  in  auflba 
cymvemion,  morpholueical  and  molecular,  a  larife  ainouiil  of  ener)a:y  maXfe 
expended.  The  metiibolic  activities  of  llie  Infant  are  more  pnniouocMl  than 
thon  of  the  iidull.  for  the  ^ake,  not  xi  mueli  of  cnergtea  which  arc  npi-oi  m 
the  vorld  without,  as  uf  en«r|^c»  which  are  for  o  wliife  burieil  in  the  rapidly 
iocreafing  muM  of  (Ivsh.  Thus, the  infant  roqaire^  over  and  ubuvo  the  waiit* 
of  the  man.  not  only  nn  income  of  energy  corresponding  to  il>o  eoet^  oftbr 
tleeh  actually  laid  on,  but  nUo  nn  income  cormpondinK  t«  the  energy  nail 
tip  iu  making  thnl  living  iiculpturcd  Hesh  out  of  tnedcad  nmDrpboit?  ptnlnii, 
fnls.  c&rhoIiydnitc»  and  it»lts,  which  serve  as  fowl.  I.)ver  and  above  thL*,lkt 
infant  needs  a  more  rapid  inetabolisni  to  keep  up  tbe  narnial  hodilv  temper- 
ature. This,  which  is  no  lefs,  indeed,  slightly  t'l.:t°)  higher,  than  thai  i>f  tfct 
adnlt.  requires  a  greater  exi>eiidilure,  inasmuch  as  the  infant  with  its  rels- 
lively  far  Larger  surface,  and  its  cclreincly  vasctdar  skin,  htsea  heat  f  ■  a  pto- 
portionately  much  greater  degree  than  doee  tbe  grown-up  man.  It  is  a  matw 
of  cnmuion  experience  thai  cbUdren  are  mure  aBfacted  by  culd  Lban  an 
ftdults. 

Thin  rapid  metaboliara  is.  however,  not  ninnifeBl  inimediatelv  upon  birtk 
During  the  firai  few  days,  Mines  pi  wdiug  to  tbe  l«a  of  weight  QientiOMil 
nbdvc.  the  respiratory  aciivititw  <>f  tbe  tiHaiicn  ar«  feeble;  the  cutbryocir 
hebilK  u*'"  us  ret  uul  t<<  Imvc  U-i-n  cimiplotely  ibrowii  ofi^  and  aa  waaMaMl 
on  [1.  4!)'l,  newbiim  nniinitU  hiuir  with  impunity  a  deprivation  of  oxyEte, 
which  wiitiid  be  fatal  In  diL-ni  Inter  ou  in  life. 

The  quantity  of  tirine  paMMit,  though  scanty  in  the  Knit  Itvo  ilaya,  rio* 
rapidly  at  Ihe  end  of  the  first  wer.k,  and  in  youth  the  quantity  of  nriiK 
paired  i*.  rehitively  to  the  body-weight,  larger  than  in  lululi  life.  Tltie  nuy 
M,  at  Icaol  in  quite  early  life.  |Mirtly  due  to  the  more  liijiiid  nature  of  llif 
food,  but  is  bIko  in  jmrl  the  result  of  the  more  Hclivc  metabolism.  For  u>4 
only  is  the  quantity  of  urine  passed,  but  nlm  the  Hinounl  of  urea  uul  eoiw 
other  urinary  cunslilncms  excreted,  rclntively  to  the  body-weight,  greater  la 
the  child  tbiui  in  the  adiilt.  The  presence  of  uric,  uf  oxalic,  and.  nccordiBS 
toeome,  of  hippuHc  adds  'in  unusual  iiunutiltef  is  a  frequent  chamrterollo 
of  the  urine  of  children.     It  is  slated  that  calcic  phoe)>liales.  and,  iodani 


THK    fHASKS   OF    I.IFIt. 


IWT 


I 


I 


\ 


tili<i«plmte§  i^nerully,  are  deficirat,  beiDg  reuiiie>l  iu  tlw  l>Ml3r  fur  the 
buildiuK  ■'['  "'  l-"^  oi^seoua  skeleton. 

AHodiili'd  |;>n.)t>a1>lr  witU  these  const nivtit-e  labors  of  tlie  jirciwiii^  ftvme 
b  the  pruuiiueiioe  at  (he  lymiihiilk  srsteni.  Not  only  lire  the  lyiu|>hiilt(' 
gUD<h  largely  developed  uiil  mnre  nctJve  (as  is  pivitHibly  Hbown  by  ihcir 
tendency  (a  diseoM  in  ynuthi,  but  the  i|iiHUtily  or  lyiiifih  ein-ulaiimi  in 
gniitcr  than  in  Inler  vHin.  ('hHrHutertni<-<if  youih  ix  the  niie  cit'tbe  thyiiiiix 
body,  vthieh  iiu'reaiifti  up  to  the  ^ecvmil  yi-ar,  itnd  tiiuy  ihcu  remain  Inr  n 
while  ctatioiiary,  but  KeiterHlly  belhre  pubertv,  btw  vultered  ii  retrocrxn^ive 
iDCtatnoriiho«iii,  nnd  frenueiilly  hnnJiy  u  vcyligc  ol'  it  rviniiiDii  beliiDil.  The 
tbyruid  [mdv  i»  alio  relnlivoly  ^reiilcr  in  the  bnbc  ihaii  in  Uh'  lutiilt:  the 
flplMti.  on  ihc  olhfr  hand,  which  growi'  rnptdly  in  turly  infancy,  i«  not  only 
aWiliilely,  but  aloo  reklively,  ^n-ater  in  tne  mhilt.  It  nwd  luirdly  be  said 
that  the  recuperative  power  of  nifnm-y  and  early  youth  i*  very  itiarlced. 

It  woidd  bo  beyond  the  Mstpe  n(  tWn  work  (<■  enter  iiilu  the  jwyehieal 
condition  of  the  bnbe  or  the  child,  ami  our  kuowled^'  of  the  details  of  the 
working  of  the  nervous  ■^tlcm  in  inlinney  i»  too  meagre  to  permit  of  any 
profitable  disciiwion.  It  ie  hardly  of  dm  to  i>iiy  that  in  the  young  the  whole 
■errouB  eystem  \a  more  irritable  or  more  excitable  ihiiii  in  later  years:  by 
which  we  probably  to  a  great  extent  nieou  that  it  is  lesK  rigid,  lera  marked 
out  iato  nhat,  in  preceding  portions  of  this  work,  we  have  fl{>okeii  of  aa 
nerviiua  luecbanisms.  It  may  be  meHtionetl  that  etimulaiion  of  ibe  varioua 
cvrebral  areas,  in  newborn  animal*,  does  not  give  ri»e  to  the  usual  tocalJKed 
movemeiits.  The  lense  of  touch,  both  as  regards  prewure  and  temperature, 
•ppean  well  derelofwd  in  the  infant,  aa  does  also  the  sense  of  taste,  and, 
pomibly,  though  this  is  dispute*!,  that  of  smell.  The  pupil  (larger  in  the 
infant  than  in  (he  man)  acts  fully,  nnd  Donders  observed  normal  binocular 
movenienitf  of  tlje  cyea  in  an  in&nt  lets  thun  hour  old.  The  eye  b  (in  nutn) 
from  the  oiiLnt  fully  *eniiittre  to  light,  though  of  courM  riiiual  nerccptions 
are  imperfect.  A*  regard*  h«ariu);,  on  the  other  hand,  very  littV  reaction 
follows  upon  Mouudit — I'.i-.,  auditory  •enxationii  term  to  bo  ilull  duriiif;  the 
firil  few  day  of  life:  ihts  may  bo  partly,  iit  lea»l,  due  to  a))M!iice  of  air  from 
tbe  tympanum  and  w  tumid  condition  of  tho  tympunir  iniiennK  ni«nibrnne. 
As  the  cnild  grows  up  his  feii»e«  rapidly  i.iilminal(:,  and  in  bis  early  yoar«  he 
poMMMB  a  general  acuteiie«>  of  »>ghl.  hearing  and  tuueb,  which  frequently 
PffOllH*  blunted  its  his  pychical  life  become  tnller.  Children,  however,  are 
•ud  to  be  ten  apt  nt  distinguishing  colors  than  in  sighting  objcrls;  but  it 
doM  OOt  MMiear  whether  this  antes  from  a  aunt  of  |>ereeptive  discrimination 
or  from  tbeir  being  actually  less  sensitive  (o  variations  in  hue.  ,\  ehjiraeter- 
islic  of  the  nervous  avst«m  in  childhood,  the  result,  probably,  of  the  more 
active  niclabulism  of  the  body,  is  the  necesnty  for  long  or  frvijuent  and  deep 
slumWr. 

Dentition  marks  the  first  epoch  of  the  new  life.  At  about  seven  months 
the  two  central  iiieiaon  of  the  lower  jaw  make  tbeir  way  tlimugh  the  tciiiu, 
followed  iromefliately  by  the  corrMnonding  teeth  in  the  upper  jaw.  Tbe 
lateral  inciaoni.  lirHt  of  the  lower  anu  (heti  of  (lie  upoer  jaw,  appear  at  abntit 
tlic  ninth  month,  the  first  molars  ut  about  the  twelflli  month,  the  eaiiiuee  nl 
fliHtut  a  year  and  a  half,  anil  tbe  tem|M>rar>'  dentition  is  completed  by  tito 
npiH-ainnee  of  the  M'ciind  midan  usually  I>ef»re  tbe  end  of  (be  •eooiid 
year. 

About  the  aixlh  year  the  [lermaneiit  dentition  cmninenvea  by  (lie  ap> 
nearance  of  the  first  pi-nuanent  molmr  beyond  the  secowl  Umponxj  molar; 
in  the  seventh  year  ihc  central  [HTmaneul  inrlsors  replace  their  temporary 
representatives,  followeii  in  tlie  n«st  year  by  tlH-  lateral  iociaor*.  In  lli'v 
ninth  year  the  tem|Mirury  tirst  molars  arw  mjiliu'ed   by  tbe  first  bictiapida. 


TRE   PRASSa  or  tIPE. 


aud  iu  the  (eitlli  year  tbe  second  toniporurj  itioinn  «re  simiUrlr  rr|ilu«d 
by  ilie  secuud  bkuspids.  The  caiiiiie!)  are  exchanged  hIkiuC  tbc  eleventlt  or 
Lwdfth  )'ear,  and  t)io  ^coiid  |)eriaaiienl  tuolurs  ate  t'lii  ahout  thr  iir«lfUi  <it 
iliirleeath  year.  There  is  iheu  a  lung  pause,  llie  iliml  or  vrltdom  iMrtb  dm 
nialciug  ita  s[i|ieunuice  till  the  seventeeuth.  or  evpn  twenty-fifth  yoor,  or  ia 
Mime  c&aen  a»t  a|ij>eiiriut;  at  all. 

r>horlly  alter  the  cmoluwm  of  the  )>erniaiieat  dcnliliou  (thv  wisdottt  teHk 
vxMpteil)  the  oix-urrenoe  of  {luhcrly  nmrlu  the  hejriniiiti^  of  •  n«w  plunaf 
life;  aud  the  dilleratioe  between  the  itese*,  hiihi-tin  merely  |H>ic4iiia]. m« 
becoDiea  functional.  In  both  Kxei  th«  maturation  qI'  ih<-  gi-tii-ratiw  ongaai 
M  nocotupHDied  by  the  well-known  ehiingea  in  the  body  at  tar^:  but  tbe 
ovrntM  are  iitii<;h  aiore  churHe[«mtic  in  the  typiual  feoinie  thiin  in  th«  abet- 
mnt  male.  Tliuu^h  in  the  buy,  the  breaking  of  tbo  voiw  sad  the  ni|iid 
growth  »{  ihe  binrd  which  iiociini|iaiiy  the  itpnearonce  "f  avtive  Sperntate- 
20a,  nrv  xtrikinf;  fnitum,  yet  tliry  are.  nfltT  all,  superficial.  The  cuma  of 
his  inrreuing  weight  and  hi-iglii,  iind  of  iho  other  ev«nt«  uf  lib  econooiy. 
pitraur  for  a  while  longer  nii  unchanged  raiim :  the  boy  does  not  beeurn*  a 
miui  till  Rome  vcnrs  uAcr  puberty ;  and  tho  decline  of  hia  functional  inu 
hood  is  so  gra^unl  that  frequently  it  c«ii«es  only  when  diaeuae  put*  ma  wmi 
to  a  ripe  old  agei  Wilb  ihe  occurrence  of  iDeust  rust  ion.  on  the  otbor  haad, 
at  from  thirteen  to  neventecn  years  of  ajio,  the  girl  atmuM  at  oooc  becoim 
a  woman,  and  her  functional  womanhood  ceaaee  suddenly  at  the  dimaclMir 
in  the  fifth  decennium.  During  the  whnle  of  the  child-l>earinK  period  Wr 
organism  is  iii  a  coniparatirelr  slatiouary  condition.  While  tM-iurr  tba  tgt 
of  puberty,  up  lo  nbout  the  eleventh  or  twelfth  year,  the  girl  u  lightarai 
shorter  than  the  hoy  of  the  same  &Ke.  in  tlie  next  few  yean  tier  raw  itf 
growth  exceeds  his ;  but  she  hns  then  nearly  reached  her  niaximnm.  while 
tie  coiiliniu^  to  fftovi.  Her  curve  i)f  weight  fmni  the  ninvtwutb  year  ■•owaril 
to  the  cliiuacliinc,  reinainii  stationary,  being  fol  lowed  imbsequenttv  by  a  kl« 
inereitse,  so  that  while  the  inan  reaches  his  ruaxiniuiu  of  weigh i  ai  ahmt 
fnrty,  the  wumiin  iii  at  her  gn-iilent  weight  about  tiflv. 

Of  the  ■tiitieiil  tlttferenci-s  of  iwx.  loinfl,  »iii'h  as  the  formation  nf  On 
pelvis,  luiil  the  ci»tnl  nicehani^in  of  n^ptration.  arc  directly  conuecdv)  with 
Ibo  act  of  chilli-bearing,  while  uthen  have  only  an  indirect  relation  to  lh»t 
duty:  "nd  i  ml  i  cations,  at  knst,  of  nearly  all  the  ehnracteriatic  diffli>reiK» 
are  seea  at  birth.  The  baby  boy  is  heavier  and  taller  than  the  bnby  girl, 
aitd  Ihe  maiden  of  live  breathes  with  her  ribs  in  the  same  Huy  n.i  ikmi  ihf 
matron  of  forty.  The  woman  is  lighter  and  shorter  tliai  the  nian,  tb*  lim- 
its in  the  case  of  tbe  former  being  from  1.444  to  1.740  luetrtii  of  height,  aiul 
from  Sa.f^  lo  DS.d  kilos  of  weight,  in  tbe  latter  from  t.4fiT  t»  1.8!KI  n?  heiglil, 
in  the  latter  from  1.467  tu  I.HDU  of  height,  and  from  49.1  to  94.&  klhie  of 
weight.  The  muscular  system  and  skeleton  are  both  abdoluMlv  and  rela- 
tively less  in  w<iniiin.  and  her  brain  ia  lighter  and  smaller  than  tiiat  of  ntsa. 
being  about  I27'J  grammes  to  1424.  uer  inetabuliiuu,  n»  moa«ur«d  by  lb* 
respinilory  and  urinary  excreta,  is  also  not  only  ahaoluiuly  but  relalirely  1* 
tbe  body-weight  less,  and  her  blood  is  not  only  leas  In  <iuiuility.  but  alin  of 
liubler  specific  gravity,  and  contains  a  snuiUer  proportion  of  n-d  cornnscha 
liierBtKOgtb  is  to  that  of  man  as  about  5  to  9,  and  the  relative  lenirtn  nf  btf 
sl^aslOUOto  lIo7. 

Prom  birth  onward  (and  indeetl  from  early  inlra-ulerine  litet  the  incr» 
ineut  of  growth  pi-OKmaively  dimiuishM.  At  Inrt  a  point  is  rvacfaed  at 
which  tbe  curve  cnte  the  abstiiiwa  lini-.  nixl  tbo  incnmtenl  becomM  a  dteia- 
ment.  After  the  mltiiination  of  iiiaiihnix]  at  forty  and  uf  wooiaohnod  at  Um 
eliinacteric,  Ibe  ptiuie  uf  life  deelinei  into  old  age.  The  meidiidic  aetivitt 
of  the  body,  wbteh  ut  first  irn*  suliii'ienl  not  only  to  cover  ifae  daily  wada. 


» 


» 


it  to  ii'M  now  iDHlorUI,  Inrcr  on  is  able  nnlv  lu  tui>el  the  iliiilr  waiiln,  ami 
nl  t«>t  in  tii'>  iiiiiN-rlVYt  even  Ui  puHtain  in  ilt  vniircty  the  exutliis  I'rnm^. 
Nrillirr  ili  n-gnnli  vigor  lunl  riinctionul  npni'ity,  nur  im  rogurtl"  nt-ijchl  nnil 
bulk,  i|[<  iIk'  itirnin^'txiint*  of  Ou:  sa-vrnil  liftiniv  iiD'l  organ*  <-<)iii('i<li-  «ilWr 
nith  ciivb  other  or  with  that  ol'  thr  bmiy  iil  targo.  W'c  hnvf  ulraiuly  (VU 
lb«t  the  lilo  i>(  tticl)  an  crgnn  ns  lhi>  thymii*  i*  tinr  Hh^rtfr  than  that  vf  itK. 
pOMCMor.  The  eye  i»  in  [t«  ilinplric  prime  iu  phildhom!,  when  it*  molia  nru 
cImpM  nnd  its  niiioi'iilnr  mrchiinitiRiv  mi«t  niutiiU-,  ami  then  it  fi>r  the  riuwl 
pan  Mn-n  as  n  tiiy ;  in  Inlor  vmre,  when  it  couM  bo  i>t'  the  gn.«t4wi  >N.Tvir« 
to  m  i>till  avlivv  bntin.  it  hu«  almcly  fullen  iiilo  »  clomled  unci  rigid  old  a^p). 
The  )ikrl«tou  rciich««  itF  limit  very  ncnrly  lit  the  »anie  time  n»  Uu)  wbolft 
fnuD*  mehcs  it<  niaxininm  of  heijihl,  the  cuiilcscvncc  ul' th«  various  eDiphysM 
being  pn-tiy  w«ll  eimipkled  by  about  lh«  tnenly-filth  year.  8iniilariv  tbo 
mnwiilar  «T«leni  in  it«  incraisc  tallies  nith  the  weight  of  th«  whole  (khIv. 
The  brain,  in  ipile  ul'thc  inereiiHing  eoniplexily  nOtructuiv  and  function  to 
whieh  it  continue*  to  nttaiii  even  in  mitldle  liTe.  enrly  reaches  it#  linitt  of 
bulk  and  weight.  At  about  seven  years  of  ago  it  Attiiiiis  whut  may  Iw  eon- 
sidere«l  as  it'  tir*l  timil.  lor  though  it  may  inerejisc  somewhat  up  to  twenty, 
thirty,  or  even  Inter  yeare,  ils  progresi  is  mueli  more  sli>w  after  than  before 
•etreo.  Tbe  va«cular  and  digestive  oreans  as  a  whole  may  conliniMi  to 
iDCrMM  even  to  a  very  lale  period,  trom  these  facl«  it  is  obvious  that 
though  the  phenoneDa  of  old  auc  are,  at  bottom,  the  result  of  tho  individual 
decline  of  lite  MTeral  tiMiiea,  ibey  owe  many  of  their  features  to  the  tlis- 
anrnogeraent  of  th«  whole  orgaoisin  produced  by  the  premature  docav  or  dis- 
appearance of  one  or  olh«r  of  tlio  coDStitueut  bodily  liiclors.  Tliua,  for 
iDsiaoee,  it  is  clear  that  were  there  no  natural  intrinsio  limit  to  the  life  of 
ih«  nii)H.'ular  and  nervous  f)-«tems,  they  would  nevenbelees  come  to  an  end 
in  c-oitr«<(ueuce  of  tlie  tiutrilivif  diHturbanoee  cuuM-d  by  the  lowi  of  the  teeth. 
Aod  what  ii>  into  of  th<-  teeili  ia  probably  true  of  niauy  other  organii,  with 
llie  addition  that  llieM  euniuit,  liko  the  tovlli,  be  rvplaoed  by  mechanical 
ronlrivanon.  Thus  thi,i  tenn  of  life  which  is  ollottetl  to  a  mu.tcle  by  virtue 
of  its  niolecular  ounnlttulion,  luid  which  it  vouhl  not  exceeil  werv  it  alway* 
pluciil  umh'r  tbu  mint  favomblt*  nnlrilivo  eoudilicm*,  is,  in  tlw-  oi^nism, 
delerniiiivi)  by  ihv  similar  lifi-ltrnw  of  nthrr  tiiwuw;  the  future  declino  of 
tbe  briiin  i*  pmliably  involved  in  the  eiirly  deray  of  the  thymus. 

Twodiangas  ctiaractericticof  old  age  are  the  fo-eullcd  cniearcoitsnml  fatty 
dagCDCnitiuiM.  Thcae  are  seen  in  a  completely  typical  form  in  eiiriiUg^,  as. 
fur  irwtancc.  in  the  rlha;  here  the  protoplasm  of  the  cartilagororiMiscIo 
becomes  hardly  more  than  an  envelope  of  fat  glob«il«s,  and  the  supple  matrix 
ia  n-nd(Ti-i|  rigid  with  amorphous  deposits  of  calcic  phoM>hale«  ami  cHrhn- 
UBicx.  whit-h  are  at  tlu-  rame  time  ibe  signs  of  past  and  the  cause  of  ftitnre 
nutritive  decline.  And  what  is  obvious  in  the  case  of  cartilage  is  more  or 
less  evident  in  other  tissues.  Kverywhere  we  see  ■  disposition  on  tlw  part 
of  protoplasm  to  tall  Imck  upon  the  easier  task  of  forming  lal  mlher  than  Ui 
nny  on  tbo  more  aniuous  duty  nf  niflnufaeluriuK  new  malerini  like  ilself: 
everywlwre  almost  we  see  a  tendency  to  ihu  replacement  of  a  structure"! 
matrix  by  a  dejicait  of  atnoq>boiu  waterial.  In  no  part  of  the  svstein  la  this 
uwre  evi<)eni  than  in  the  arteries;  one  conimoa  feature  of  ol<l  af^  ts  ilie 
oonvertion  by  siirh  a  cliauxe  of  tlie  supple  elaalic  tubes  into  rigid  ehannela. 
whereby  the  supply  to  the  variouu  tiieueaof  Dulrilive  material  is  rendeiv<l 
iofireasingly  more  diHlcuU,  and  their  intriuric  decay  prvtportionately  hurrie<l, 
Of  tbe  various  tii4u«e  of  the  body  the  muscular  and  nervous  are,  however, 
ibose  iu  whidi  tbe  fuiK-tional  decline,  if  not  rfruciural  devuy,  beeotoes  aoonest 
apparent.  Thedyoaiuic  coeAicieDt of  ilwtkeleial  muoclea dimioiabw  rapidly 
alter  thirty  or  fbrty  yeata  of  life,  and  anmilurwant  of  power  ooiuea  over  the 

61 


1010 


THE  rnASES  or  life. 


ra  tbt 

1 


pUiti  iimtwulnr  fittrr*  al»n;  iW  heart,  (bouKli  it  may  not  (liiniobk,  or 
tamy  slill  iiicrciuw  in  wi-ij;ii(,  poMciwiw  luM  awl  lex  force,  aiul  the  amvw 
uf  the  InUstine,  l>Iii<l<i<.T,  aixl  utiier  orxauH,  <llmi»ii*li  iu  vigor.  In  the  ocrr- 
Mia  Hj>l«iii,  tbo  liiicw  of  mtiittaiicfi,  winch,  a»  it«  hav«  ao«u,  belp  In  map  <M 
ibe  centnU  orgiui«  iutu  inechaniftmK,  und  ho  u>  produce  iU  iiiulufiiri«n 
.  actioiM,  bocomo  at  Imtt  hiii<lnuuT9  to  tlM  puMigc  of  nerroua  tiupubo*  tn 
dirDOtiuD,  wbitfl  at  ihi?  »uan:  timv  the  molecular  cneisj'  of  iIm  impuUei 
•elv«e  becomca  lott.  Tli<-  oyc  l>vci>mM  fnblo,  tint  »iily  fnim  nl»ii<Iina«  of 
medta  oihI  prMbyofHC  mtiAcular  inabilitjr.  btit  aUu  I'mm  ihc  wry  bluDUtOMof 
thoretiiin;  tlic  vni^^ory  aixl  motor  irapulmv  pom  with  iorrvMug  alownca  ta 
and  from  thv  cpiilriil  iutvouh  vyvtcni,  an<l  ib<;  bmin  brcouun  A  mors  and 
noro  rigid  mttSf  of  pr<>l»plik»ia,  tlic  molcculiir  linc«  of  which  riitlior  mark  ibi 
hlrtori,'  of  past  iiclioii*  rnlhcir  ihiui  errvc  n«  indi<:«tions  of  prixeut  |iot«Bc;F- 
The  cjiitbc-iiul  glunditlnr  vlBiuaDts  seoni  to  be  tho«  whum  powers  ara  tbt 
loiigCHt  prcMtr\'vd ;  iiiiil  bunce  tJio  man  whu  iu  the  prinH'  of  hia  manhood 
a  "  nartyr  to  dj^spepfia  "  by  reason  of  the  wiisitivriic»  of  ^tric  nerni 
the  reflex  iiihiuitory  and  other  rceulu  of  their  irritation,  in  hia  lator  ~' 
when  his  nerves  are  bhinted,  nail  when,  therefore.  hi»  peptic  cells  iirc  &! 
pursue  their  chemical  work  uudisturbcd  by  extrinsic  nervous  worrios, 
and  drink.*  wttb  the  oouro^  and  sucooas  of  a  bov. 

Within  the  range  of  a  litelime  are  eomprieetl  many  periods  of  ■  dxkv  or 
test  frequent  recurrence.  In  spite  of  the  aids  of  a  complei  civilization,  all 
tending  to  render  the  eonditloiui  of  his  life  more  and  more  equable,  man  still 
sbowB  in  his  economy  the  eflects  of  the  seasans.  8ome  of  ibeae  are  the  dirM 
requite  of  varying  temperature,  hut  some  probably,  eticb  as  the  K*'"  **f  «eubt 
in  winter  and  ibe  loss  in  summer,  arc  habits  aoijuired  by  iloacenl.  Witfia 
tlie  year,  an  approximately  monthly  period  is  oianifefited  iu  the  fejaali 
meoBtruatiuu,  though  there  h  no  ejcact  evidence  of  eren  a  latent 
cycle  in  the  male.  The  jibeuuinena  of  recurrent  diMiam!^,  and  ibe 
critical  <Uys  of  many  other  malwliee,  may  bu  regnr<lod  a.*  pointing  to  cy^l 
of  amaller  duration  than  that  of  ilie  mouu'a  revolutiuu.  unltm  nc  admit  ibf 
view  urv«<l  by  ttome  authum  that  in  tlieK  cascu  tbe  roeurrcuctt  i"  U>  lie  attrib- 
uted rather  to  periodical  pboM!)  in  the  diwdue-pruduciuf;  germ  lUvlf,  than  W 
variittjoiu  in  the  medium  of  the  disease. 

Pnimiitenl  Hmon;i:  ull  other  eycHeul  event:>  i:t  the  fiict  that  mmi  animah 
poWMiing  a  ncll-develupeil  nerviMi*  iiyalem,  mtwt,  nigbt  afWr  night,  nr  day 
after  day,  nr  at  leaM  linn:  alV-r  time,  lay  lliem  dona  to  sleep.  The  siUmM 
feature  of  sleep  i*  Uia  ottwition  of  the  nuloaiatic  activity  of  the  bnin  :  it  it 
th«  diastole  of  the  cerebral  bent.  Kui  the  condition  t»  not  eonEnwl  h>  tfar 
cerebral  hemisiihcres  ;  all  part*  of  the  hmly  either  directly  or  indirectlv  takt 
sliare  iu  it.  The  plicnumuna  of  sleep  are  |K:rha|w  aocn  in  their  simpleat  form 
ill  tlt«  winter-sleep  of  hyhnrnation,  to  which  cwpecUUy  cold-blouded  a^'iimk 
hut  alsii  li>  some  cxtrjit  warm-bloiKle^l  animals,  are  subject.  In  tbew  cm 
the  cold  of  winter  slackens  the  vibrations  and  Icasens  tno  axplosiooa  nt  tlw 
pm(u|»Ia»m,  not  only  of  nervous  but  also  of  imiscubtraiM)  glandular  sme 
turvs:  indeed  ilic  activity  of  tbo  whole  body  is  lowered,  in  8on»e  res]wob 
almost  t»  actual  arrest.  At  the  same  time  that  the  labor  of  tbe  oerebtll 
muIceuW  liocomes  inaiifficicnt  to  develop  cofudousneas,  the  respiratory  oeotrt 
is  either  wholly  quiescent  or  discharges  fooble  impulun  at  rare  iotervaKanl 
tbo  heart  boats  with  a  slow,  infrequent  stroko,  not  by  rea»on  of  any  inlubt' 
torr  restraint,  hut  because  its  very  substance  in  its  slow  nwleoular  travail 
esn  gather  hnul  for  ex  plosions  only  after  long  |iausc«  of  rest.  And  sud 
few  ami  distant  lnonts  as  do  ooctir  are  amply  sufficient  to  meet  the  needs  of 
tbe  tboble  metahoiiain  of  tbe  several  ItMues.  The  sleep  of  every  day  difin 
ttom  the  sleep  of  winter>cnld  chiefly  because  the  slackening  of  motecaUr 


TUK    P0A8K5   OP    Lirs. 


1011 


I 
I 


I 


ICtivitMM  n  <)ur  in  tho  termer  not  to  oxtrinKic'  hiii  to  intriniiic  oiutM.  not  to 
chaogM  iu  tlic  medium,  hut  to  oshituglion  i>r  the  »iibjuet,  nnii  bocautc  lli« 
plMQomeoi  Bra  Ui^geljr  confiuod  to  the  cerebral  hcn]i«pUi.Tm.  It  it  tnii;  thnt 
tbe  whole  body  sham  id  the  eondition.  Tho  piilsQ  unA  breathing  niv  stom>r, 
the  intc^tnc  niict  »lhor  iiileninl  miiwulsr  mechnnianis  arc  more  or  l«n  at 
rcflt,  the  eccrcliDi;  orj^iiRs  acv  ic«  active,  some  appari?iittv  being  whollir  qoi- 
est'ent,  and  lh«  sici'iior  »n  Wiiikiiig  nib«  his  erM  to  brini^  hack  to  his  ninjunc- 
dva  its  needed  Dioislure.  Indeed  the  who]o  mclabolism  and  tbe  domndent 
tamperatiire  of  tlie  body  are  lowered ;  but  we  i-annot  say  at  prewnt  how  tkr 
tbeee  are  the  indirect  rranlts  of  the  condition  of  the  nervous  syalem.  or  bow 
ftr  iliey  indicate  a  partial  «[umbeiini;  of  tbe  several  tissues. 

Thoracic  respiration  is  said  to  become  more  prominent  than  diaphraf^inatic 
reapiralion  during  sleep,  and  the  Cheyne^toxes  rliythoi  of  respiration  (see 
p.  491)  b  frw|ucntly  observed.  Uurin);  sleep  the  pupil  ie  contracted,  during 
atep  ileep  exceedingly  so :  and  dilation,  uflen  unaocompanied  by  any  viable 
morements  of  the  hinhs  or  body,  takes  plaue  when  any  sensitive  Kir&oe  it 
Mlnulnted:  on  awokine  also  the  pupiU  dilate.  The  eyeballs  have  been 
guieimUy  described  as  being  during  sleep  directed  upward  and  converging 
or,  Bccording  lo  aome  authunt,  dirergjng;  but  others  maintain  (hat  iu  true 
sleeri  the  visual  axes  ore  parallel  aud  directed  to  tbe  br  distance.  The  eyes 
of  children  have  been  deecribed  as  ctintiDually  executing  duriui;  dieep  move- 
iuent»,  tilVeu  irregular  and  uatymmi'trlcul  and  unocoompanied  by  cbKiigee 
in  tliv  pupiU. 

We  arc  not  at  |>rt«eni  iu  a  pwitinn  to  tnux  out  the  ovciil*  which  culmi> 
luic  in  thU  inactivity  of  the  cerebral  ttructurok  It  ha*  Ix-en  urged  thai 
during  sleep  the  hruin  ix  augpmiu;  but  uven  if  thi*  aim-niin  is  a  conatODt 
accompaniment  of  itlet^i,  it  niuitt,  like  the  vascular  condition  of  n  gland  or 
any  olner  active  iirgnn,  be  rc^nlvd  as  an  effect,  or  nl  least  as  a  «uli«idiarv 
event,  ralhcr  than  iis  a  primarv  causes  Nor  can  the  view  which  regartts 
sleep  OS  the  r<«ultof  a  shifting  ul' the  mechanical  arrangements  of  the  cranial 
circulation  bo  considered  as  satisfitctorV'  The  oxplanalion  of  the  condition 
is  rather  to  be  sought  in  purely  molecular  changes;  and  the  analogy  betweeo 
the  systole  and  diasti^le  uf  the  heart,  and  the  waking  and  sleeping  of  the 
brain,  may  be  profitably  pushed  to  a  verv  considerabM  extent.  The  sleep- 
ing  brain  in  many  rSBpeols  closely  reeenibles  a  quiawent  but  still  living  veo- 
Iricle.  Bolh  are,  a>  far  as  outward  niauifestalions  are  concerned,  at  rest,  but 
both  way  be  awakened  to  ocUvilr  by  an  adequately  powerful  stimulus. 
Both,  though  (|uie»cent,  are  irritable,  in  both  the  quieooeDee  will  uliimalely 
give  place  to  aoiivity.  and  iu  both  lui  appropriate  tumulus  applied  at  the 
ritchi  time  will  detertuiue  the  cliangv  from  ml  to  action.  Just  as  a  single 
pnok  will  under  certain  ciraumttance*  awake  a  ventricle,  which  for  some 
seeoads  haa  been  luotionlew,  into  a  rhythmic  activity  of  many  beats,  so  a 
loud  noise  will  start  a  man  from  uleeii  loiu  a  long  day's  wakefulueas.  And 
just  OS  in  tbe  heart  the  canliac  irriiaoililv  b  lowcat  at  tbe  beginning  of  the 
dfautole  aud  iucreiues  onwanl  till  a  beat  Mirata  out,  so  b  xleep  deepot  at  its 
«oumenc«meDt  after  tbe  day V  labor;  thenee  onward  slighter  and  slighter 
itimuli  are  needed  to  wake  the  sleeper.  Forjudging  uf  (he  depth  of  ordi- 
nary nocturnal  iilecp  by  the  intomty  of  thv  notM;  requirMi  to  wake  the 
sleeper,  it  may  K-  tv>iiclu<bil  that,  inereoaii^  very  mpidiv  at  finit,  it  reacliee 
iu  maximum  within  thu  tint  Itour;  from  thence  it  diministiM,  at  first  rapidly, 
but  afterwaid  more  »liin'ly. 

We  caouot,  however,  at  present  make  any  definite  sint>-mont)>  concerning 
Iht  oaurc  of  tbe  molecular  changes  which  ilctermine  Uiix  rhythmic  rise  aad 
Ml  of  cerebral  irritability.  The  &ct  ihat  tbo  produci*  of  protopboiBio 
■divily  wbe«  ihcy  oocumulalc  within  tbo  protoplasm  appear  to  booome  In 


1012 


TII&  rrtASBS  or  tirs. 


ealijU 

f3 


tbe  end  an  obftruclion  lo  thnt  nctiviiy,  hnxsugcvetcd  the  i(Ii.-nlliai  tW  ]irr»rOf« 
in  ibe  cerebral  ligeiip  {>f  uu  excc«e  nf  the  prmlitcU  nf  ncrrmis  in<-Uiti'ilirm  n 
Uie  <'au»e  of  ilecp.  In'ieed  luetic  ncid,  thi>  incnuue  of  vhich  uriu  sapfwMil 
to  be  llie  caUf«  of  the  acid  reaclion  of  muecular  and  nervous  ttuum  aiier 
exercise,  haa  been  eBpecially  pointed  to  in  this  coilDectioti ;  but.  iia  me  hm 
wen,  the  acid  reactiou  iu  quefelioii  appears  Dot  to  be  due  to  any  incrraMd 

Sroductiou  of  lactic  acid.     Bcfiidee.  if  the  sccuniulntion  of  metabolic  [inv 
ucW  of  any  kind  were  the  caune  of  sleep,  it  is  not  cleor  why  we  ehiMiU 
ever  have  any  hope  of  uakin},"     More  may  he  said  in  f*vor  of  the  c*>ai 
lion  that  during  the  waking  hoitia  the  expenditure  of  oxyeeo  exceedi 
invoine  and  thai  the  (|iiic«cence.  which  we  call  tieep.  comes  trntn  lhi<  <    ' 
lion  of  the  body's  ttore  of  iisygen,  more  esjwcially  of  that  "  intnt-mol 

oxjften  of  which  we  spoke,  in  d^aliug  Vfilh  th«  revptratioii  of  (he         

Uut  tn  this  view  luii-il  be  added  some  hyjiotheBia,  auch  ih  th«  liyplny  ofnov 
iuhibiiory  medianiitm,  « hereby  tbe  rellpirutut^■  cetitru  ijt  not  mtuied  to  ib- 
created  activity  by  thin  lack  »f  oxygen,  for  ai  we  have  itrfu  the  lirrnihtitj 
sliarea  in  the  dluiuber  of  the  body,  lliouj[h  continuing  in  piny  with  u 
amount  of  enervy,  which  |icrnii Id  a  gradual  mioraiion  nf  th(.>  lott  itoreaf 
oxygen  aud  do  finally  brinic!*  on  the  awakening  vrliidi  end*  thtr  sleep.  And 
tbe  uccrafiity  fur  such  u  cnniplication  indioatCN  thai  tlu;  cxplntiatioo  i*.Bl 
prewnt  nl  leuM,  inadi-ipjali.'. 

The  phciiumc-Jiu  nf  xlcej)  nhow  very  clearly  to  liow  litrg«  au  exiMit  lo 
apparent  anioinaliiim  iit  lIic  idlimatv  outcome  iif  the  elTrclB  of  nntcceilnl 
Mimulation.  Whr-n  wu  wioh  to  fio  to  idcep  we  withdraw  oiir  automatic  bniD 
H  much  fl.->  [KiHsibKr  from  the  inflncnoc  of  all  CxtTin«ic  •tiniuli ;  and  an  ia- 
1crv»tin^  CH'c  i»  rrctinlcd  nf  n  lad  wlioi>i-  connection  with  ihr  external  norid 
was,  from  a  complicated  anicsthevia,  limited  to  that  aOordcd  by  a  singlecyi 
and  a  single  ear,  and  who  could  be  sent  to  sleep  at  will  by  cioaing  wcf^e 
and  slopping  the  ear. 

The  cycle  of  the  day  ia,  however,  nianife^ed  in  many  other  w«ya  than  bf 
tho  allerualion  of  eWping  an<l  waking,  with  all  tlie  indirect  eH^cl*  of  ibo* 
two  conditions  There  is  a  diurnal  curve  of  temperature  (tw  p.  6-19),  ap- 
parently independent  of  all  immediate  circuiuslances,  the  bereilitnry  iniprva 
of  a  long  and  andent  «ei|uence  of  days  and  nights.  Even  thv  puUc. « 
•enaitive  lo  all  bodily  chan^cB.  sluiwa,  running  ibmugh  all  the  immeiliaif 
eflTedn  of  the  changee  of  ihe  minute  and  the  hour,  the  working  of  a  diarvil 
influence  wbidi  cannot  lie  ai-counled  for  by  waking  and  alet'ping.  by  «urk- 
ing  and  reMiiiK,  by  rneulu  and  aholiuence  between  meals.  And  the  mmt 
may  be  «aid  concerning  the  rliythni  of  mpirallgn,  ao<l  the  ■inxlucta  of  pal- 
monar^-,  cutaneous  antf  urinary  excretion.  There  seema  to  Iw  a  dailr  iwrw 
ofbodily  melabulitim,  which  in  not  the  product  of  the  day'a  avBOts.  'XVitUa 
the  day  we  have  the  narroni-r  rhythm  of  the  mpiratory  ceiitrv  with  tlw 
accompanying  Hue  and  full  of  nclivitv  in  the  viiiuimoUir  oenln-d.  .\ail 
lastly,  ihi-n.'  stiind"  out  the  fundamental  fa<'1  nf  all  lioilily  |wriiMliirily.  ikit 
alicrnnlinn  of  the  heart's  fiyttole  and  iliiistok-  which  cascf  onlv  at  lUnlli. 
Though,  as  wc!  have  *crn,  the  intcnnitlcnl  flow  in  ihi-  arlcnt-ji  'u  loueil  ilm 
in  tht  ciipillaricM  to  nn  appnrrnlly  (•oiiiinni.Hi"  How.  slill  the  coii-^tnMtK  iw 
I>enlrd  cycle  of  tho  cardiac  (huttic  must   leave  iln  nmrk  ihr..  Iif 

whole  web  of  the  bwiy's   hfe.     One  mwins  of  invt^igalion  m  .r. 

riill  too  groM  lo  pcnnit  us  to  truck  out  ile  iultucn<-c.  .Still  lit«  are  hi  «I 
present  in  a  nceition  to  ^ay  how  far  (he  fundiimenial  rhythm  of  the*  heart 
ilsclf,  that  rhythm  which  is  intlucnccd.  but  not  cmilcd.  by  the  ohaon  ft 
tW  body  of  which  it  is  the  centre,  is  iho  mult  nf  ccvniical  cfaanf;>ei,  lae  rr 
Hcction  as  it  were  in  little  of  the  cycles  of  the  univerM>.  or  how  liar  it  b  ih* 
outcome  of  the  iahercut  vibrations  of  the  molecules  which  make  up  iu  nh- 
Htanec 


J 


CHAPTER    VII. 


DEATH 


Wbek  t)iv  aiiitiiul  kiiigiloni  is  surveyed  from  a  bmwl  iiiaii(l[M>iiit.  U  be- 
cnfnf*  ohTicM-i  thikt  lliit  nviini.  or  its  cuitelHtin'  (be  »pr.rm»Uy):.nna,  \»  the  giwl 
of  nn  iiiili villi) 111  i;xi»lri]cc;  lliut  life  is  u  cycle  beginning  in  nu  ovum  itnd 
eoRiittg  round  to  nn  uvum  tigiiiit.  Tlin  gnwter  pnrt  of  the  ■clton*  which, 
lookiDK  from  a  amr  point  i>l  view  at  the  bii;bt>r  niiitnal*  nlno«,  wo  nn;  apt 
In  rorutidcr  m  iiminriitly  tbc  piirposw  for  which  niiimikls  ounii!  inli)  exi»t«noG, 
whi-n  viowwl  frmit  ihr  dixtiiul  oiitlcdk  whcniv  the  whole  living  worlil  u  tar- 
Toywl.  fiulc  uwny  into  thd  likaieM  of  the  rauro  by|)lnv  of  uTum-boitriDg 
orguinnit.  The  Rnininl  body  i*  in  reality  a  v«]>icl«  for  ova ;  and  nfldr  the 
liw  of  Iho  paivnt  has  become  polAntially  renewed  in  the  offspring,  the  body 
r«iDain«  iii^  ■  cm i-ofT envelope  who^  future  U  hiii  to  rlic. 

Wcft- liu' nnimal  friinie  not  lh«  conifdi'wicit  mnchinc  wc  hnvcwonit  to 
be,  death  might  come  lis  a  »implo  and  gmdiinl  itimiliilion.  the  "  wins  overj* 
thing"  U'lii^'  the  laat  etoge  of  the  iiiicceHive  Iuh  of  fumlamcntal  ponren. 
Ad  it  iw,  however,  death  is  always  nioro  or  len  violent ;  the  machine  comes 
to  aa  end  bv  reowMi  of  the  disoraer  caused  by  the  breaking  d'lwn  of  one  of  | 
its  {NUU.  Life  oenses  not  because  the  molecular  powers  of  the  whole  body 
tlackeo  and  are  lost,  but  be(»u»e  a  weaknefe  in  one  or  other  part  of  the 
lunchinery  dirows  it*  whul«  workins  nui  of  gear. 

We  hav«  seen  that  tlie  central  factor  of  life  ii  the  circulation  of  tiie 
blood,  but  we  have  aita  m«ii  that  blood  b  not  only  umIm*.  but  injurious, 
UolaiH  it  i*  <luly  oxygenated  ;  and  we  have  further  m>«ii  that  in  the  higher 
animal*  the  Dsygcnation  of  the  blooil  can  only  t>e  duly  olTecleil  by  meant 
■  >f  th«'  rv9pinitt>ry  muncnlar  u)ccliiini*m,  prtsHdetl  over  by  the  molulla  ohloD- 
gum.  ThuK  thf  life  of  a  c<impW  nniinal  li,  when  r<<ducc<l  to  a  simple  form, 
eom[NiH-d  of  Ihm'  factor* :  the  muinteniini-v  of  the  circulation,  the  aocoai  of 
air  to  the  luGoiogluhin  of  the  blixiil,  and  the  funclional  activity  of  th«  !«• 
tiMratory  centre;  and  denth  mny  eouie  from  ibc  nrrcrt  of  cither  of  these.  Al'^ 
Itirhal  [nil  it.  death  tiikw  jilacc  liy  the  hcjirl  or  by  the  lungs  or  by  tlM 
liniin.  In  rviilitv,  liowcvvr,  when  nv  pioh  the  Bnalysis  further,  the  ooolntl 
tact  of  death  is  tlie  stoppage  of  the  heart,  and  the  conee<)Ucut  srn^t  of  the 
cir«ulatiun  :  the  tisMet  then  all  die.  because  thry  lose  tWr  internal  medium. 
Tlw-  failure  of  the  heart  nmy  arise  in  itself,  on  account  of  some  failure  in  its 
iicrvouH  or  muscular  elements,  or  by  reason  of  some  miecliief  aSecling  its 
mechanical  working.  Or  its  stopiwgv  may  bo  duo  to  sotne  fault  in  Its  inter- 
nal milium,  such  lor  instance  as  ■  waul  of  oxygenation  of  the  blood,  wbioh 
in  turn  may  be  caused  by  either  a  change  in  the  blood  itself,  ai)  in  carbonic 
oxide  imisoninf ,  or  by  a  failure  in  the  mechanical  c-onditioua  of  reapiratioa, 
or  by  ■  ceesatlOD  of  the  action  of  the  rapirutory  centre.  The  failure  of 
this  centre,  and  indceil  that  of  the  bean  iuelf,  may  be  eauaeil  by  nervous 
uifluencci>  itruceediiig  from  the  brain,  or  brought  into  o|>eraiion  by  meana  of 
the  central  iicrvoua  system  ;  it  may.  on  the  other  hand,  be  due  to  an  imper- 
fei.-t  tttate  of  btuod.  and  thia  iu  turn  may  arise  from  the  imjiurfeict  or  |>or- 
verse  action  of  various  ceoretory  or  other  tiMues.  The  mmlo  of  death  ar«  in 
reality  as  DumennHi  aa  are  the  poaible  nMdlfications  of  the  various  Gurfom 


L 


1014 


dkatu. 


of  life :  l>ul  they  aII  rod  in  k  Mnppnge  of  tbo  dmilation,  uk)  tbc  «itli- 
dnivnl  frnm  lh«  listut^t  of  tlirir  ini«riinl  niMium.     Hroce  w«  c»ni*>  (o  cdc 
sidcr  the  ilenlh  of  iho  hody  n»  niBrkc<l  hy  the  cefcation  of  tbc  bntrt'a  bt*l. 
ft  CMMilion  frotn  which  no  recovery  i*  possible ;  ntid  bv  ihie  no  are  nulilcil 
lo  lix  an  exact  lime  at  whieli  W(i  toy  the  body  ts  deatf.     We  cnn,  bovrvvrr, 
Ux  DO  BUch  exact  time  to  (h«  denth  of  the  individual  litsiies.     They  are  not 
mechanisni!!,  and  their  death  it  a  gradual  \iist  of  power.     In  the  caw  of  tb* 
coDtrnclile  tissue;',  ire  have  apparently  ■□    rigor  mortia  a   fixed  tenn,  b^ 
which  we  can  mark  the  exact  time  of  their  death.     If  we  admit  that  mfba 
onset  of  rigor  morlia  recovery  of  irritability  is  imposuble,  then  a  ripd 
muKle  is  0D6  permoDrotly  dead,     lu  the  case  of  the  other  tiiisueA  w«  btt* 
no  Bitch  i>bjective  eij-n,  aince  tbe  rigor  morlU  of  aimplo  pruioplaani  nutni- 
festa  itself  chiefly  by  obscure  cbemical  ngns.     And  id  all  ca:«s  it  is  ubriow 
that  the  piiBttibility  of  recovery,  depending  »a  it  docs  on  ibe  skill  and  knml- 
edge  of  the  experinieDtcr,  is  a  wholly  artificial  siuo  of  dealli.     Vet  ««  an 
draw  DO  other  sharp  line  belween  ilie  secniioglr  dead  tinuie  wh<«v  lifv  h* 
lliekered  <lowti  into  a  Hmoulderitig  ember  wbicli  cwi  still   he    fanned  bark 
a){ain  iulo  flame,  nud  the  bandfiiT  of  dimt.  the  n^regalA  of  chirntiiail  Nib- 
Btaiicea  iutu  which  ihe  dccoiniKising  tiMiii<>  finally  cruml>leiL 

Moreover,  tbc  fiiiliire  of  ihe  heart  itMlf  u  at  Imtton  1<M  of  irriubQitf. 
mid  the  prunitiiljly  of  recovery  hr.re  aluo  n-sto,  a«  far  as  is  kDUWii  at  prcMi^ 
tiu  till!  nkill  and  kntiwledge  of  lUwv  vho  iiltempl  to  recover.  .So  that  ttUr 
all  Ihc  I'igiii'  of  tbo  death  of  the  whole  body  are  as  artificial  M  ib<M>  of  tW 
dcutli  uf  the  coDslitUGDt  lis»tic>^ 


APPENDIX. 


ON  THE  CHKMICAI,  BASIS  OF  THE  ANIMAL  IIODI 


iiKsalniBl  bodj,  rr»m  n  cbeuiical  pointof  ci«w.  mity  he  reeardcd  uaniixlaro 
,  €>f  rRiioDK  rcjirpMDtitilvtH  <if  ibre«  large  oImhm  o(  cliemkal  HDbaUncM,  tIk.,  pro- 
leida.  <:>rbohT<lnil«s  tind  fnt*.  iii  nmocidtJon  with  ■mtillrr  qaanlitio  of  vmioun 
••line  and  other  uyttallinc  b»tli««.  Ily  pratciil*  are  mmat  bodin  coDtuiniug 
«ubon,  oxygen,  hyJroKni  iiiid  uitroKen  tii  a  oeruin  praponton,  rarying  within 
DaiToir  liiDtlt.aii(I  havlii)!  crriaiii  general  fmtorea;  tbeyarc  frf^iufnuf  iiiolLpa  of 
aa  albumiiKHd*.  B,v  carliohydrsi««  iin<  mranl  MaKhea  and  •iigiim  and  tbtir  iiJIio. 
We  have  also  Krrn  ihnt  thr  animnl  body  may  be  conaidcred  aa  an  aMemblage  r>r 
protoplaani  uiidtrT  viirinut  ni«clifii!iiiLon<i'nndi}rniimeroaa  praductaof  protnplaamic 
adivity.  We  di)  nut  nt  prtoeui  know  tiiiylhing  deflntle  about  Iho  Diotecular  oom- 
poritMMi  oriictivc  living  protoplasm ;  but  nben  we  ■iibmit  )irotoplaani  to  cheioka) 
aoaljttt,  ia  which  met  \i  ii  killed,  wo  slwnini  obtain  froin  it  a  conaiderable  ijuaii' 
tity  of  the  material  spoken  of  a*  prolcid.  A  iid  manr  nuthora  gn  no  fur  ua  In  apeiik 
of  prohiplHam  aa  bt<ing  purol;>'  iinileld  io  nature;  ihey  reganl  ibe  liviiiK  proto- 
plkMn  M  proteid  malehal,  whtcli.  in  pitMJng  from  death  to  lift',  box  BMiinicd  cer> 
tain  cbaraclrni  and  pmuinahiT  bas  been  chantcfd  to  <-(>n>tnictioti,  but  itill  i*  pro- 
Uid  natteT;  ihey  eoaielimrs  spmk  of  pnitoplmin  ns  "liviiij;  jtroield  "  or  "  living 
^bmaiD.''  It  ia  worthy  of  notice,  liowrnT,  ibnl  even  liuiple  lormB  of  pmloplaem. 
like  that  ci>ii«tittitloe  toe  bodv  uf  n  white  cor|>uitcle.  forma  of  proto)>la«m  which 
we  may  fairlv  conaider  »»  native  protoplaKtn.  when  they  can  be  obtained  in  auf- 
fideui  quiuilily  for  chemiral  annlyni*,  are  found  lo  contain  aome  reprnwDtatirc* 
of  uirUihydrntra  and  futo  iw  well  a*  of  proleidi^  We  might.  perbaM,  even  go  aa 
Imt  M  Io  My,  ibat  in  all  forma  of  liTinKprotoptaam.  the  proteid  baalala  fonad  npon 
aonlyxia  to  bare  tome  cafbohydmte  and  aome  kind  of  fat  aanocijued  with  il.  Fnr- 
ther,  not  only  don  the  normal  food,  which  it  eTentiially  built  up  into  prolaplaam, 
eoaabtof  all  Ibrec  dnun.  but.  na  wo  hnvc  tern  >n  Ihc  lecliona  on  nuiritioti,  i>ro> 
loplasm  mivea  rixe  hy  melobollam  to  nieiubem  of  the  aanie  three  claaw* ;  anil,  an 
far  aa  we  know  at  pnaeot,  carbohedniiea  and  fais,  when  formed  in  the  bodv  ont 
of  proteid  fiHxI.  art)  $0  formed  by  tlic  tucvaty  of  living  protoplnam.  by  aome  lii-ing 
Uaaue.  Hence  there  is  at  least  loiiie  leaiwn  for  tliinkinjc  it  probable  tfaal  ihemQle- 
eule  of  protoplasm,  if  wo  may  lue  >ucb  u  pliraw.  is  fur  muru  complex  than  a  laolfr- 
culvof  proleld  mnller,  that  it  eouiaini  in  itM-lf  raldoce,  »o  to  a|iMik,  not  only  of 
profeid,  but  aUo  of  carbohydrate  and  fatty  material. 

Be  ihla  aa  il  may,  for  no  dntpnntic  i^tatefneDt  can  nt  prraenl  be  mode,  whein  ws 
examine  the  varioun  lijuiie*  uiid  lluidi  uf  the  aniuial  liutly  from  a  chemical  iioint 
of  view  we  find  pmeiil  in  dillVrent  idacea.  or  at  dilferent  times,  several  rarielir* 
and  drriiativea  of  the  ihiec  chief  gIomio.  wc  find  many  forms  of  pruleicb,  and 
bodi*4  cIuMly  allied  lo  pnitrida,  in  the  forma  of  mucin,  gelatin,  etc.;  many  wie- 
ties  of  fata;  and  Mveml  kiiidi  of  carliohydraten. 

Wo  find,  moreover,  muny  ulbrr  brHtin  which  we  mar  rexnid  aa  atagoi  in  Iho 
coMtmciivc  or  de*lructive  metaboltwn  iif  boili  native  ana  differentia  led  prolo* 
plasm,  and  which  are  important  not  no  much  from  the  ijuantity  in  which  they 
occur  in  the  animnl  liody  at  aor  one  time  aa  from  their  llirowing  light  nn  tite 
nalor*  of  animal  mctaboliaiu ;  these  are  aurh  bodies  as  urea,  other  organic  crya- 
talline  bodif^.  and  (be  extnwtiTes  in  general. 

In  ibe  following  pagta  ih*  cbemical  featurm  of  iba  more  important  of  ibeae 
nrioo* aubaiaDcca  which  arc  known  to  occar  in  the  animal  body  will  be  brfeflj 
eOBiJdwed.  aiH-b  cbaraciera  only  Iteing  deicribed  ■«  pOMeaa  or  promiae  to  pow«aa 


lOia  APPENDIX. 

phfwaloxioal  intorat.  The  pbysiologiul  fonclicin  ottny  oubtUnc*'  miial  (]<'[iMiI 
ullima(«r]r on  ita molecalnr (inclndinK  itn  chi'iaicali  tiKlurp;  nml  Iti'tujth  kt  pr*ciil 
our  cliemical  knuwled^je  at  tb«  coagtlluciiu  or  aa  auiiuul  inklv  ^'im  lu  biit  little 
infi^bt  into  tbeir  pliysiolo^k-al  [iroperciw.  it  cannot  be  doubts  tbai  «ticrb  cliiai- 
cal  inf»rnifttion  a*  in  altninablo  i»  n  nvtvvury  preliminary  to  all  |>by<iiot«gl(Bl 
Hludf. 

PBOTEIDS. 

Then  fbrm  th«  iirlocipa]  aolldB  of  the  mu«oular,  n«Trou«,  iind  f  landular  tiauo. 
of  the  wraoi  of  tjlood,  of  tteroLi*  flnidi,  aimI  of  Ivmph.  In  a  hviilitiv  condition, 
■weat,  tMra,  bile  nnd  urine  cnnliiin  mere  tr«ciw,  i^aoy,  of  pruicida,  Tii«ir  genual 
peroeotfl^e  compiMtlioii  inajr  he  Iak(>a  as 

0.  H.  N.  C  6t 

From     S().9  CD  I&2  61^  Of. 

to  2S.&  to  7.3  to  17.0  10  fi4^  1o  i  (I 

(li(ippe-8i]rl<r.t^ 

Then  HxunM  Brv  obUiiKwl  rn>iu  n  wiuidenlton  nf  nunieroiu  aatlyuM,  rilglii  -  't 

■lie  rarlena  itaulu  Imliii  Iminitrrial,  irliarv  (h*  jiurtly  uribn  (ubtUinc*  ofna'.  tl 
li«doDn<talv  listennliioi, 

111  adilitiun  111  tlin  nl'iif  AinMiliioiitciinitpida  l«a*««in  iitiiilimi  a  *iir<<  iridiA 

In  Ilic  uuf  of  e|u  nlbumlti  iha  ;irlu<-lpaj  cuiiiitltnvnuof  til*  »>li  irx  vlit-  i  I'ain  u4 

|iiitaMi<tm.  Ihi^  lnlUr  icrMilyvxuHHint  tho  ronuor  in  aiii>-iunu     Tl>r  in:  ihtlMfrf 

ciJliim  (IkI  lulnuiiim.  in  ■•>iritiiUfitii>ii  irilli  phrupboru-.  iiilpliiirtc.  i>u<i  I'ldxaal 

icr^  iuiliII  4fuan1iliDd  of  {u1t.>lillri,  n>a^n«iir>iEil  aii<l  ir  i'      ti    r  i.'-,  t<  r'   r>  T^nl 

U  aLi^ft  A  ImoF  of  >L|jrfi,'    Th<*  a*H  '>f  frnifil-aJhuiMi          Ir 

liUt  Iht- ruli  rtf  Il.n  jifuTui.ii  of  iriutcle  *iiiilaiu>  nn  i-v  ■  ■   ii  ;i,ii  ,.i:  il.i 

titlnrvol  IheptinuccUon  <>rilic  iipii  niih  tliu  nnjiniil  it  all  II  a  iiia(t<f  >■!  olxt'driiy.  UMnafi"* 
|](Mtiiitltjl>in  j«  KiH  (j^  l^nv*  iiii  »Jh  on  icntV^I- 

IVolddn  u  met  wllli  in  Ibr  animal  body  are  all  amufplioiw ;  rodic  bit  folu 
«>iHiie  intnlublo  in  wnter.  nnil  iiU  ntc,  for  ibf  mnit part,  iluolublo  in  altnliolt 
«lbcr:  (licyart.'  all  lolubic  in  iinirii;  ntidiariO  nlkatica,  bat  in  lirC'>aiin);di*«Jtid 
modtly  undi-r|;i>  dee'^iuiiOBition.  Tiieir  Buluiioun  i>iiiu«iu  it  Irn-baml^  iiiiaviii 
ncttoo  on  the  ^lanc  >if  pulAri/.iliuii,  the  amount  depending  on  vAriau*  cirtus- 
stanoos.  and  boioji.  <rith  one  rxccpiiin,  vit.,  pejitonca,  cliangcd  by  beatiii);. 

'CiyilaU  iaio  »ho«*  coniprii><i'<ii  rvrtaic  imiUiit  (tapieiiiallj  globnllii)*  cleiiwiiit  ••(et  mn 
liAt  tiDoa  obaarvad  (n  tha  *euil>  of  iiihiit  pUnu ;  ai  y»l  (h«y  liat-*  nni  beam  Mit.ila>rf  aaf. 
Ilolaullr  luUM  ar  In  r^tiinliti-M  liiriv  ct'ioufli  Ut  firrmil  •ny'mnla  aimljaia  la  b*  mait 
A  mvlliol  of  iiolatloit  In  ciDantilv  aail  r«i'cyalaltulnf  tliuM  •uMuuiVf  liu.  Ivowenr.'lMM 
liiillcalwd.aad  it  •ctma  probable  tbat  analyaiaof  llieae  inar  load  to  lUlafvatinf  lilf.iiinallwi 
uu  tha  aulyMl  of  tlia  cvnililuUnu  and  ODmwnalioii*  of  |inil««d*> 

Tie  prcacDC«  of  pratt-ida  may  he  drtprininod  by  Ihe  folloiting  Icets  : 

I.  Hrat«)  with  ilranx  nitric  acid,  Ibcy  or  their  Miliiliuna  turn  y«llaw,  ami  thb 

nilor  I*,  on  tfaendditiuD  uf  ammonia,  or  cauHlic  ftoda  or  pr>la*h,  cliangvd  tvadw]' 

urwngtr  hue.     (.Xanthoproteic  reaction,) 

i.  With  Millon'H  rcatcent  they  givr.  when  prraent  in  milTlctfnl  <|UBntiiy,  a  fw 

cipttato.  wbii;h  turn*  rod  mi  hrniins.    It  tbi-v  nrr  'inly  prexini  in  lra<'M,  no  pn- 

dpilalir  ii  ublnincil,  but  merely  a  red  colotsiion  of  the  w>luli<in. 

3.  ir  niiied  with  Home  coneenlraied  solution  of  sodic  bydrale.  aod  oti<>  or  two 
dtotwi  of  u  Nolutioi)  of  oupric  aulpbalo,  n  violet  rulor  I*  obtained,  wbiob  dMpaoi 
ia  tint  on  boiling. 

Tbe  above  Mtie  tu  del«ct  the  Mmalleat  trace*  of  all  prDl«>bl».  Tbe  two  fallovbl 
tcatii  may  b«  uoed  irhen  ibere  i«  Diora  (ban  a  tnoe  iirvwiit,  but  do  nut  bold  to 
erory  kind  of  prot«id. 

4.  Render  Ui<i  fluiil  xtronEly  acid  irith  noetic  Of  other  acid,  and  aild  a  few  Anf 
of  a  anlution  of  fcrtucyauiue  of  putaJHiuoi ;  a  precipitate  atiiina  thfi  prwBBM  •( 
protddl. 

■  ""  ■'   "i -■■M.B.ta. 

■    ■  wi. 

■  |i|f!i^-.  Jipiim   I  [.■,ir,.  ii.Hi.    ->.  I..  IM.  IIX.  MNTtt.  AXIt 


K.  ICentler  lli«  lluid,  a*  befoK,  lUoagl  v  mM  witti  &<.«t!f  ncli],  add  nn  <v|iisl 
TuIuiBc  of  ■  cotiL-etiiritWd  M>1utlan  of  todtc  »iilpluii«,  aixl  boil.  A  pfNipiUbi  t> 
Ibnnod  if  proutiik  i*  itraMot. 

ThlaUMrwctiiiii  imvful.not  nnlrou  ■cixunlofitHZBflnMs.butBUBbMBUM  thartamDlB 
iumI  proluM  oo  <l'<>'iii[i>mii<>ii  »f  AilMr  budiM  whlob  iiidj  tw  iimtnlj  aiul  liaac*  aftar  fllln- 
liDB  Uie  Mne  lluM  nikf  lis  [iiril>«r  *nAlrwd  fer  other  ■abMaboM.  Adilitlo^iat  mctlwd*  of 
frvaui|*<n)ii1iini  Train  |iiVtMil>  aivi  acMulatinC  with  w^tlo  u-iiluiil  tfiiliiil- nvoiJinsMljr 
•soMOf  th*  >»•! '.  |irepl|>IUIioii  h^f  exoMofalathol ;  lu  IIm  Ullcr  oub  thn  tolulioo  tiiuil  M 
nvalnl  or  fititilly  t^i'l  lloppt'ScjleH  iMoninwiiil*  (he  cmpln^inenl  nf  a  atuntod  •olntlon 
Af  fttobly  |in>i-t|iitBt«il  hnie  lijdnM,  fn  MmUc  xml :  thi*  it  *i1iIkI  Ut  (Im  Mlutlali,  »Iiil  m 
botllag  til*  wlioie  Kf  ihApratoliU  *re  pmdpiUleJ  m  v*II  u  the  rarrio  hIi.  Um  latlor  ■*  a  bMio 
•(•taM.  Ilni<t*'»  Riaelind  oF  reuiovmii  ifi*  t*«t  tnu<(*  or  pnit«iil»  fAini  f  Ijincvii  mliidim*  U 
*Uii  iif  iiH  |n«  g]ycoa*n>.  I'tTCi|ikalfu>i  of  ttio  IjuI  tninv  uf  jirulciili  b)r  ruauu  of  li/dntod 
«ii<l«  nf  kail  ala  twiliiig  tcnijwnlijrr'  inii}-  im  nlio  rtaplgjrwi. 


Prolcid*  na;  be  cniiveDiently  divided  into  cIhmw. 


Ci.AMt  I.  ^/t'rc  .l/AitmiiK. 


4 


Mcrabem  of  ihia  clnM,  a*  Ihpir  name  iinjilir*,  nccur  in  a  nnturai  coaditiOD  in 
nnimal  t)«UM  aad  fluid*.  Ther  ar«  soluble  in  wnter.  ara  iiot  pn-ci  pi  luted  by  rery 
dituic  aL-lda,  br  ciirboiiaiai  of  the  alkalica,  or  by  amlium  chlunile.  Tlicy  an 
voa^tilaied  Ity  heating  in  aoluiioii  to  a  U'lnjwrature  of  about  7"'  C.  If  dritd  at 
40*  ('.,  the  rtviilting  mana  I*  'if  n  I'nlc  yellow  color.  CMily  friiililp,  laalitlcw,  inodor- 
OUa  and  nalublc. 

t.  BcB'Alburola. 

t'ornia  In  aiiueuus  Milution  a  aetitral.  tranaiiareiil,  yHlowbh  fluid.  From  tbia 
it  la  prmipiuted  l>y  excwaof  aining  alcubol.  If  lb«  al«ubol  be  rapidly  rcmoTcd 
tbe]>rKi|iitoU)  may  b« readily  rcdlaaalTwl  In  witlvr,  ir«iibjeoUMi  tuleiietbicr  action 
■  coaculalion  occ-'um,  and  ln«  albumin  is  then  no  InnRcr  iliui  aolublc.  KtruQg 
acid*,  eapeclally  nitric  ntid,  cauic  a  coagulation  ximilnr  to  that  produced  by  hcAl 
or  br  the  nmloogrd  action  of  ak-obol ;  ibo  albumin  bcooaio  profoundly  chaniced 
by  llic  Hdlon  of  tfae  ui'id  itnd  due*  not  diaaolve  upon  rciuuval  of  ib«  acid.  Mer- 
curic chloride,  argentic  nitriiie.  and  lead  acetate,  (>reciiiii.->te  the  albumin,  funuing 
inaahibtc  comiHiund*  of  Tariable  cnmpoution  with  it :  ih«  prooipituila  may  b« 
rMHOvtd  by  roeHDn  of  aulpharoltod  hydrogen  and  (he  albumin  agaip  obtained, 
a|tii«r«iilly  unalietrd.  in  M^lutioiu 

ntning  iir«tic  acid  in  excoM  ic'*^  "^  pr«cl|>llKl«.  but  when  the  aolutlan  U  cod- 
cetitrat^l  the  iillxiincn  M  iranaJToriiied  intua  transparent  jelly.  A  similar  jelly  la 
[inxluuW  when  atioTie  cauettc  potash  i*  added  In  a  i-oneentrated  sniulioa  of  ent* 
aDiuntiu.  In  Wh  ibne  caaea  the  Mibelancc  w  profoundly  allwcd  beeOBing, In 
the  (loe  COM,  uoid :  in  the  other,  allculi-nlbumiu. 

'Hie  apedflc  rotalofy  iiiwer  uf  c^-ftlbumin  in  nqueoua  aolHtlon  la,  for  yellow 
lichl.  — ^.6^  Kydtochloric  acid,  added  until  the  reaction  h  stroaxty  acid,  ia- 
creaaM  Ihii  rotation  to  —37.*'.  The  fnrmnlioo  nf  the  gelatinnus  conpuund  with 
i-aiutic  puiiuh  ia  at  firat  accompaniiK)  with  an  increaie,  but  Ihia  la  followed  bj  n 
decreate  of  nitatiun. 

tWp-ifiii-'ii,  White  of  hca'*-cf g  b  broken  up  with  aciaaon  Into  small  piece*, 
dilnml  with  an  c>]ual  bulk  of  water,  and  ilie  intilure  shaken  aUnnply  in  n  llaak 
till  quite  frothy ;  on  atandinic.  the  fonm  riaca  to  the  top.  and  carrica  all  the  Sbrea 
In  wliow  roeabworlc  the  ultiumin  wiu  c^uloincd.  The  fluid  from  which  the  foam 
liMbeeo  remond,  la  atraiiied,  and  trMtedcarefullv  with  dilute  acelio  acid  aahmg 
M  uj  ptecipilate  it  fanned ;  the  preeipitate  b  then  filtered  off,  nnd  the  ftllrato 
Kfker  ncu trail jEitinn  coiicentraled  at  40"  to  il«  original  bulk. 


Serum  -  nib  umtn . 


Tbitfonnof  albuniiit  rcaemblM,  to  a  ptat  extent,  (he  one  previously  dwcrlbed. 
The  fullowing  may  suHIm  as  dlalingulahlog  fratorea: 

].  The  taeeillc  rotation  of  eerum-albumtn  b  —S^;  llut  of  egg-albumin  ia 
— ^."i'.  bolli  mensarfl  for  yellow  light. 


«d.    I 


(it>(M.,ft«7,  ■  IMknalMar,  btiMhr.  r,  ini|nM>'CI«n->M,  tl.  iinntftail. 


i 


lOlS 


APPEXOtX. 


i.  Swum -albumin  k  uot  i-auBuliied  by  bcii)g  ilukra  uji  with  rtbvt,  ria;-kn»- 
BUD  is. 

.1.  Scmm-iilbuniiii  in  not  vtty  rptidily  iirrcipiiiird  by  *ui  ng  byilruchlorlc  idd. 
uihI  ouch  picd[>itii[e  >l>  doc*  occur  in  r«m<lily  rcdUiwlTcil  on  futlhcr  addilioii  urilw 
aeid ;  the  exact  jvrtnn  of  lh<M  l*ro  restu'tM  boldi  gbod  for  vfg-a1bun>iB. 

4.  Pndjtllated  or  coagulated  «crum-albiiiDiu  is  r«a«ljl  t  folDbrc,  ryx-albuBiio  il 
with  difiicult}-  fKiliibIc,  in  Rliv.nii;  nitric  a«id. 

5.  fr^-slbumin,  if  injf^'lcd  nubcalcDcoutly  or  into  o  vein,  a p[i vara  uDaltntd  la 
tli«  uHdc  ;'  BLTum -album in  uniilarly  injecied  doM  not  tbiu  iMTinallj  |i«a*  ooi  by 
tli«  kidney. 

Sernnt -album in  is  found  not  only  in  Mnoii-wrum,  but  b1»i>  in  hnifb.  bath  thai 
CODtained  in  tbc  projief' lymphatic  cfaannvli  nod  Ibal  dittuHcd  in  the  ti»ue*;  is 
c)ivl«.  milk,  Iran ludn lion H  n:id  loiitiy  puiliulu|;ii-ul  fluiila. 

It  V*  ibis  furm  in  wbicb  Hlbuuiiu  gt'cvrally  ajipeHTn  in  the  urinp. 

In  addition  to  (lie  bIwvd.  ticL«r*r'  Lun  ilocriUr'l  two  rIOKly  relalid  lulW,  Ui  abiifk  )>• 
SlTW  Ihn  iiniDiK  juinilliiimiii  nixl  iiwUlbuiniD.  Thv  fint  lie  oMalnvd  Itoia  irtanali  I'^ff*;  m 
■IkaliD*  loluiioiii  ■»  raninikaUa  for  bclDg  ven  tojij.  Il  Hvaii  ikniUAil  •li««jHTiU«la4/ 
ba  erolaiih  it  HilT'^naMiiibly  iiKvmpMilTon  Ihjm  lliMe.  Haeitia* giiva  a*  htaOMpnUta^ 
0.  3i.S.  B.  n.9,  .V.  i:.H.  C.  £13,  D.  I.t  jiw  mdL  ll  twoiu  to  ba  ametatol  wliL  H'Xm  W; 
like  Elyw^Qi  oijiaUe  of  being  DDbireit«)  itklo  a  •utrilnuuc  ei<ini  tL«  r>'  -^ 

MslaJbiiiiiiii,  fuUDcl  in  •  ilrnniiMil  fluid,  tvnmbl**  tliv  iirfci-'iiiiK.fcvl  ii        '  i  tf 

hydfochlohc  add.ciT  by  antic  add  aiid  bTRH-yaiilde  afiioUiainBi  ^  it  ia  j>rr('>|t  1111*4.  w  »* 
wagulalad.  by  alcobol ,  ita  aolDtion  I*  (nirorly  oupiIilM  r-n  boiling. 

Albumins  are  gCDerally  fniiiitl  nisncJAled  wiih  rntiill  but  deGtiilc  anuniiHa' 
•■]!ae  mulicr  A.  Scbmidi'  hoi*  (hut  lliry  niuy  br  frrrd  rrom  tlicae  by  dlalyM, 
and  that  ibcy  urc  then  not  cooi^ulutod  <m  bulling.  From  ibia  It  mlgbt  be  Infmrri 
Ibat  the  albuutiu  uud  ihe  aulme  uiaiters  wiie  peculiarly  telateo,  anil  tliai  il> 
latter  pluycd  «onie  specini  pari  diirin);  the  coRgulalibu  of  lh«  tanatr  by  hm 
Sehmitll'a  oborrvntion^,  however,  have  not  been  corictanively  c<MTo1xint«d  by  Mb- 
■ecjueut  olim-rvfrn. 

('labs  II.  Derive^t  Aft/imiHt  tAtbumiiuitety, 

I.  Ac  Id -albumin. 

When  a  native  albumiD  iri  suliition,  such  ad  aeruni-albumin.  ia  ireHied  far  Mae 
little  lime  with  a  dilnle  acid,  »ucli  as  hydrochloric,  the  pmperlie*  lK«(>me  enllrdy 
changed.  The  mnat  mntkrii  channe*  are:  (I)  itiut  ihe  inlutiun  ia  no  loogtf 
eosgnlated  b>  hrnt;  [2)  that  when  the  lolution  in  carefully  nruirnliied  the  wbula 
of  Ine  proleiu  ia  thrown  down  ai  a  precipitate;  in  uiber  wi'irdH.  ibe  MTuinalbumia 
which  was  soluble  lu  water,  or  ai  least  In  a  neutral  fluid  onliitnintc  only  a  anufl 
quantity  of  neutral  taltn,  hnii  become  conrerted  intoanitwlanire  invilublu  in  waw 
or  in  ainiilar  neutral  lluid>.  The  body  intii  which  aeruni' album  in  thud  becann 
cooveried  by  ibeM^ioo  of  an  acid  ia  aiJitkeii  ofas  ncK/-aU«Mii>.  Iia  characleriKii 
fealure*  ari-  that  it  ia  iuHoluble  In  distilled  water,  and  in  Dcntral  Mline  MilutinM 
anch  na  thote  of  sodic  chloride,  Ibnl  ll  ia  readily  wluble  in  dilute  iicidH  or  dihnr 
■  Ikalica,  nnd  that  lis  MilDCions  in  acid*  or  alknliea  are  not  conKiilatcd  by  boilin; 
When  iiua|i«ndcd,  in  Ihe  undiiunlTrd  alntc.  in  water,  and  healed  to  Tt'"  C..  il  bt- 
eoiBM  ooafulaied.  uud  ia  then  uudialint'nisbable  frfia  coagulated  neruni- albumin, 
or  iDdetd  troni  anv  olher  form  orcxisgulnteil  proteid.  It  is  evident  that  tbr  im^ 
atance  when  iu  sotulion  in  n  dilute  acid  is  in  a  dillertnt  rondition  frmii  that  n 
which  it  ia  wbcn  precipitated  liT  mill  rail  ration.  If  a  iinaiilily  nf  aeruni-  or  r^ 
albumin  be  treatiiil  >rilh  diluli-  liydrochlnrie  acid,  it  will  be  found  Ihat  the  me 
vvrrion  of  the  native  iilbtimin  into  ucid-albumin  ia  gradual;  a^|>eciuleu  lieaitpl 
to  7fl^  < '.  iminediately  alter  Ibe  addition  of  the  dilute  acid,  will  ronf^ulwte  alsal 
a«  uaual;  and  annUier  apecioirn  taken  at  the  fame  time  olU  ii^ve  liardty  auj 
precipitate  oa  neutral iutioo.  Some  time  later,  the  iuicrcnt  dcjwndiDit  on  tb* 
prof>onionof  ibeacld  to  thealbumin,  on  tcoiperpture.  and  on  other  circunutaKe^ 
the  coagulHtioD  will  b*l«a«,aad  Ibeneulralintion  precipitate « III  be (WBaldrrabl' 


■nnko^nreb.up-ii 
r.  IVlliol  aaal..  IM-K 
•  aBn-4(rClMan.ui'i    < 


^o, : 


'^dc  rAilioiniiiuncBraieltailMr:  slBlxluiaan.jlJtb 

.  ll.,  *.  lav 

*  kurV)  Jtiehtv.  s).  iin»i,  a  i 


thioiin  doK'B  oil  ncuirnliuitiiin. 

If  fiDdf-chofiptd  miuole,  from  which  the  aoTublc  albumins  bare  br«ii  rMOOved 
br  repMUd  waahiDg,  be  treated  Tor  tame  iltiie  witli  ilitute  iO:i  jrer  cent.)  Iiydio- 
cfalonc  add,  the  ircaicr  put  nf  tlio  muscle  is  diMohed.  The  Iranoparvnt  acid 
filtrate  containa  ■liiriti'  ((imiititr  d(  pmtHd  inntrrinl  in  n  form  wtitcli,  in  ita  gen- 
eral cbaracten  at  Icuat,  ugnm  iritb  acid-utbumiii.  The  ncid  anlutiun  ol'  the  i>r<>- 
leid  i>  not  ci)«eiilaled  by  boIKu^,  but  the  irhol«  of  ibe  proteid  Is  pn-ci  pi  titled  on 
ncuir»li»ition;  and  the  preclpiuie.  Insoluble  In  neutral  *odic  i-hlriridr  (oluitoni. 
in  rendity  diwolvrd  by  rvrn  dilQUi  nridti  nr  nlkntie".  The  proleid  thim  obtained 
from  mUKcIc  hiia  bci-u  mlled  n/nlonin,  bill  wc  bnvr  at  pnvriil  no  iiitisfiiclory  I«4t 
Ui  diniinsuitb  the  acid-albumin  [or  iTDtoiiin)  prepared  from  inuHcle  from  ihnt 
prepared  from  egg'  or  serum-albumin.  When  coaurulaled  albumin  or  oUicr 
cosBulaled  protfid  or  fibrin  >■  dinolved  in  xtrong  adda,  acid -albumin  ii  rormed ; 
andwhen  fibrin  or  any  ulfacr  prolrid  in  acicd  upon  bj  fcaatrk  juice,  twid-albuBiin 
la  QDeofihi^  firetprodui-ta;  aud  ihcne  iicid-albamins cuinot  be  dbtingulabed  from 
aeld-albuiiiiii  (>re|>Hr«d  from  musile  or  native  albumin.  Though  nydrocltlorie 
acid  i>  prrbnpR  tlir  mn»t  eoovcnirnl  Rcid  for  fornilng  acid-albunin.  Other  add* 
may  sUo  he  ii*ed  lor  the  purpOMo  of  tirrpnritiic  it.     Acid-albomin  in  toluble  nol 

tonly  In  dilute  alkolle*,  but  alao  io  dilute  Kirutioni  of  alkaline  urbonatfa;  tla 
voluiion*  in  thtee  are  not  coagulated  by  holUng, 
If  (odic  phosphate  in  exrera  i*  added  to  an  acid  solutioo  of  acid-albumin,  tbc 
acid-albumin  n  predpilated;  thii  also  occun  on  adding  iodic  acetate  or  pho*- 
phate. 

Ah  upecial  te«lt  of  acld-albumln  niar  be  glren:  1.  I'nitial  coa|^latloD  of  its 
•oiniton  in  lime-nairr  on  boiling.  3.  FurUier  precipitation  of  ibe  Mine  folntioo 
after  boiling,  on  Ibe  adililion  of  caldc  chloride,  magneuc  aulphate,  or  aodk 
chloride. 

JDlaaolved  In  very  dllul«  hydrochloric  add,  add-albumin  (ayatonln)  prepared 
ftom  nusdepoaetaMaaBpCviDclnvo-rotatonrpowerof— 72*  for  yellow  light,  tbU 
bving  independent  of  the  concent  rail  on.'  On  hcMing  ibe  solution  in  a  closed 
Ttaael  in  n  wiiirr-lialh,  the  roUmrj-  [lower  rim-*  to  — 818°. 

The  body  kDonn  n*  panipeptuue.  which  mnkrn  ita  appeann^e during  the  peptic 
digeaiioB  of  protf^id*  in  closely  allied  to  the  ■ubnUuiccii  juol  dncribed. 

3.  Alksll-albumln. 

If  aeruni-  or  egg-albumin  or  wnahrd  nuede  be  trealed  nllh  dilute  alkali  litftead 
of  with  diliile  acid,  ihe  i>roleid  und«rgo«a  a  cbiiiige  ijiille  fiimilar  to  that  which 
waa  bmugbc  about  by  tne  acid.  The  alkaline  •oluiinn,  when  the  rlungo  lua 
become  cainplc4e,  ia  no  longer  coagulated  by  he«t.  the  protcid  i*  wholly  preclpl- 
taied  on  neutralliailou.  and  the  prrcipitatr.  insoluble  in  wnler  >ud  in  nculral  aodio 
chlorine  •olulloni,  is  readily  Mluhle  in  ililutt-  acid*  or  alkallei.  Indeed  in  a  gen- 
eral way  it  may  be  (Hid  iha't  aild-ailininin  and  alkali-albamin  are  nothing  more 
tluin  aolutioDn  of  ihe  name  ■ubalnnce  in  dilute  .icids  and  alkalim  mpe«lively. 
When  ihe  precipitate  tiblained  by  (be  nruiraliiationof  n  noliitiuu  of  acld-Blbamln 
in  dilute  add  la  dbaolicd  ioadituK!  alkali,  il  mar  be  eonudered  to  become  a) kali- 
albumin;  and  coniertely  when  [lie  ptecipnie  ol'lained  from  an  alkali-albumin 
•olutinn  i*  diivfdrrd  in  dilute  mid,  it  may  \«-  regarded  »%  add-Blbumin. 

It  ia  utalrrl'  ana chararteriiilii'  ri'iulinn  ni  Ibia  muiliDrd  or  derived  albutntn  that 
it  ianot  precipitatrd  when  ila  alkaline lolutioun  mm  neutraliced  ia  theprcwBCWof 
alkaline  phoiiphates;  aolmlona  of  acid-albumin,  on  the  contrary,  areaaid  to  b« 
prrdpltaled  on  neutral  I  sal  ion  to  ih*  preaence  of  alkaline  ph<i*pbale>.  and  ibU 
difference  i*  coniidered  to  bo  a  diatincnifbiiig  feature  of  the  two  prateid*.  But 
doubt  ba>  been  caat  on  Ibn  BlateiueoL 

Alkali-albumin  may  be  prepared  by  Ibe  action  BOt  only  of  dllole  alkalie*;  bat 
alio  of  alrong  cauMtit!  alkalies  on  native  albusilna  an  well  a.1  on  coaguUteil  a1ba> 
min  and  other  protdda.  The  jelly  {-rodoced  by  the  ntiion  of  ouMic  potaab  oji 
whiteofepg, ipukenof  in  Clam  1.,  1.  la  alkali-albumin;  the aimilar  jelly  produortl 
bj  alroag  aceltc  add  i*  acld-ulbamin.    One  of  the  moat  productive  nethoda  of 


&    bj  alroag 


■  Umipe^cTttV.  Bilti  fliTi.  ralb.  Cium.  AliaL.  BiL  IV.  (L«t),  %  VA. 

•  nep|i»-i«ii»«.  ibc  <-it.  s  IV- 

•WjiVa.     rHipR'tArcb.,tl-l.  lU  •tr(n,!>  MI, 


^ 


1020 


API>BKUIX. 


obUloioK  ul kali ' kl lilt m in  U  that  inlroducwl  bjr  Li«l>erkEihii.' and conftiua  In  vlilitif 
■  slrone  idutiuu  of  c:iii*lie  f^tiub  lo  fiurifiM  white  of  ecg  until  Uie  *borv-inw 
lionod  jelly  It  oblain^d.  Tliin  ii  tb«ii  l-iii  Into  tmsll  pteom.  and  iliait-Md  uabl 
i)iiil«  whlt«.  Tbe  Iuidjm  Hre  i^bon  dionolved  bv  hratine  on  lh«  wnt«r-hatli,  tad  tbt 
alknli-nlbiimin  prccipitatod  bv  (lie  cnTodil  niMiliiin  of  acetic  itcid. 

Both  alkali*  and  acid-albuniiii  me  u-iih  ililKculty  prucifiitaud  by  alrahol 
tliMralltHlinoor  ncidflolulian*.  Tbo  imutniJixatlon  {ifevipilalea.boNeTtr,''" 
ooagulatwl  under  the  pra]oa;ged  action  of  alcofaol. 

Til*  bfldr  "prutciu,"JM.>ribed  lijr  Muld«r,k|>fwan,iftl*xi(Uat  >1I,U  W  eUaal^ miaM«l 
witb  tlkli  hody.    All  *iil>*n)uaiit  olwervvr*  hnv«,  liumvM.  bll«J  u>  oMilnii  lii*  tivwk. 

The  rotatory  power  of  alkali-albumin  ntriea  according  ft  lia  XMirce ;  tbuavluB 
prepared  by  alroag  cauMltc  tiotiuli  Iroin  aeram-albainln,  the  rotation  rtMi  tnm 
— 06*  (that  of  aoruiii-nlbiicnin)  lo  — .Sij° ;  for  yellow  ligbl.  Similarly  pmand 
from  <gK-albuiDin.  il  riM»  from  —3^-5°  to  — 17° ;  and  if  from  conjnilalM  wfatia  «f 
^g.  it  nm  to  68.8°.  Hence  the  exUtence  of  rariooa  form  of  ancKll-albtuoin  b 
probable. 

In  additinn  to  ilie  methoi*  glToD  itburB,»ll(ali-«JbiijBln  lay  b«  >1m  r—dily  «hiaia»l  kf 
■haklaji  milk  witli  Mmnii  otutlif  tmla  •ululi<in  niiil  •ili«r.  roiBOving  tho  •ihvrlal  (biIbUiw. 
ginvipilating  llir  rviuniDiui;  lliiU  wIlli  tcaiif  ui-id  and  wiuhlug  tlic  pncijitLale  wilb  mtim. 
oold  alculii-l  and  Filler 

Tbe  niml  natiMfnctorT  method  of  regarding  acid-  and  nlkali-Blbumin  u  to  coo- 
Mder  ihuiu  iw  rccpuctivcly  ucid  iind  iilknii  compouDdi  of  tlie  DPUtmliKalioo  pre- 
cipitate. W«  have  reoMMi'to  tliiTik  tliutitheii  tlie  precipitate  l«diHaolved  In  eltbcr 
nn  acid  nr  an  alkali.  U  doea  ei)[«r  iuiu  txinibl nation  witb  llicm.  The  aeulrallu- 
tiuu  prcicii>iiate  i«  in  itnelf  neither  acid-  nor  alkali*albuaiin.  but  nay  bvcoot 
cither,  upon  Kululion  in  the  ro*pPctire  rengcnt. 

Ii  il  pmbkblt  llui  Mvtr*)  <l«rir(ot  nltiumin*  riin,<  Jil!«rinE  uvwIiDit  io  tba  jimuiUl  tma 
whioh  (hc^flrv  lanaei  or  (nuibly  *L-ui>rdiuK  Is  lb*  uiodc  of  iWr  |mpualhia.BiiJ  itulnd 
<if  lli*M>  may  ax  id  ill  Hi  mrr* Ulii*  Tmm»nf  M4d-  aad  idkiilJ-iilliulHla;  but  Ui*  wliala  MilfM 
requlr«>  taitimt  iiiivalij^lion. 

Aoid-albumin,  prepared  bv  the  dirri'i  nclion  ofililuie  ooido  (in  natire  albumin. 
or  on  Eaiucle-iubiiiaiii-».  coiilaiiiii  auli'liur,  as  tihowu  l>y  the  brown  ooloratiou  wUdi 
appeaiawheii  ibi- prei-ipltateEa  bt«ted  wItJi  caustic  |>olasU  in  the  prvaenoeof  biife 
lead  acetate.  Alknli-albumin,  at  all  eventi  aa  prepared  by  the  aolioit  of  elroui 
vuuBtit-  poliub  oriioda,  di»C«  not  contain  any  >ulpbur;  and  the  acidalbumin.  pre- 
jured  by  tile  ■■ilulit>u  in  an  acid  of  the  neotralitUion  precipitate  froiu  Mich  as 
alkHll-alkuuiin  aoluiiou,  i«  Hlinllarly  tree  from  Bulphur. 

*.  Ouala. 

TbU  it  the  wdl-knoirn  protoid  eKiMinic  in  milk.  Whco  freed  from  (at,  and  ia 
the  moiot  condition,  il  ii  n  irbitu.  friabte.  npn^ue  li'uly.  In  miMi  of  it>  react  * 
il corteepoflda clMcly  iritbalkali-albuBiin;  tbiu  it  isreadily  uilublelndilatei 
and  alkatiei,  and  i§  re-iiteclpilated  mi  iientralli^tliin ;  if,  however,  itotoMlo  | 
|>liit»  in  prenent^  oa  la  the  caM  in  milk,  the  eoiutton  uin»t  be  Mrongly  arid  bdbft 
any  precipitate  b  obtained. 

Vartoiu  rMcHsot  1i*t«  al  diffareiil  lttn««ti«aa  OMijtiwd  Mim»>Ii>  »  diiiii>';ii:<t>it.(  ii  ttat 
(liBcloMir  alliiMl  body  olkati-itlt-uiniu.    Law  rurMrrbci  h*>'  ^4 

•o  tauvh  dnnbt  on  (mm  diUvrcuoH  Hint  the  idoniiiy  nr  mxi  .Ji' 

ull'uuun  rauit  (Utl  bo  left  mi  opsa  iiumIIoo,  th«  dltc'uMiou  vl  •n.i.it  Yri>L.iij  na  nm  <»  |UA 
her*. 

OMBin.aiounirrlDg  la  loilk,  hat  had  Mtfral  melioat  aatribnl  W  i(.  M^aroicteriMlei  ImI 
Ihea  low  their  inporuuiM  on  oMuideiliii  that  milk  containt.  tn  Hl<lllian  to  tmada.  oitm 
•«hllAaow.  wii'li  ■•  |i  il-uiifl  phMphit«.  anl  a  iiaoilwr  of  bodiM  which  yield  M*da  by  brntMi 
Uttsn-    Tha  prMHoce  of  pitouio  pli«i   'i  .'     'i  <  -  ub  >«paai«l  mlluauo*  oa  Ibe  rawiUMitaf 
mwm.     Id  11m  entire  aMeaoa  of  tVi*  .  .^.id  lo  Ibe  •lUjIUii  qoaslitiai,  m  aian  ft- 

bjii'C  aiihydnda.gUet  a  pfeoipiul*;  l>  i  Ji  it  pceiani.  <\irb>nu^  aiiliydrida.  k>>«*  an 

tmapflala,  and  ontie  aeid  only  ouo  whqii  Uia  mIuUoii  !•  atld  tnioa  (ha  preauKH  of  b««a«<> 
aii.l  iijt  rrocn  that  of  acid  paloaio  jihoapbate.' 

>  FtaMtodorff^  Anaalen,  M.  luirt.  ■.  It*. 

*  Kamir.   nanriAteh..  M  ivN.ii>C«u&'l*i. 

*  Au*  JCUK  l-Hitb.  d.  t*yiul.  Cbtm..  IM.  fl.  M. 


OnSUICAL   BASIS  OF   TU£  AXIUAL  BODY. 


10:11 


VThtn  i>np*TtA  IVom  mitk  hy  ms^iriic  *ii1t>b>rp  (Me>  bflnw),  tnri  by  eibrr 
(ram  fau,  aoi)  ijignolvcd  in  witttT,  cnarin  powcMwii  ■  iprdlic  mlulory  pnwrr  of 
-^80'  §0T  yrlluw  ligln  ;  iu  Olluie  iilkallnu  solutioiis.  ot  — Tti^;  in  vlTOUg  alkkline 
•ohitiow,  of— !'!' :  in  ililiile  hyitrdcliluTiu  acid.  o(  — SI". 

Caacia  h*»  bcrn  wturtcd  to  occur  in  muadv.  in  t^rnu*  iluiil*,  and  in  blood-aerum 

iM-rum-ca*rin).  In  many  eawa  it  ban  probiiUly  brrn  courouDdcd  wilb  gUibaliD* 
»te  Clan  III.);  but  blood-aeram  and  iDUncli'-pliiKinii  iiodoubti-dlr  coutain  an 
aJkall-albuDtin  in  addition  lo  whatever  globulin  may  be  [TeMnl,  ^ut  Ihe  u«ual 
dnubt  exiats  as  to  ihoidcntityof  tbi«wiihliuecnaciii.  Its  prewoco  mity  bp*howii 
bj  adilinti  dllulti  ncetic  jirid  to  blao<I'ii[>riim  wbirh  ba«  bcra  ffrcd  from  globalln 
bf  a  cntrt-nl  nf  cnrtionic  atihvdnilc ;  a  dialiocl  prt'cipilale  i«  (lirown  down.  A 
uibaooce  diniilaT  to  i-uavia  fiaa  also  bi-en  dmcrlbed  aa  exbtiiig  iu  uwuialed 
moBcle  and  in  ibe  nrntcplnntn  of  iicrvc-cclln. 

/Vrporo/fon,  [>iliit«  milk  nitb  fevrrni  (10  to  1.')  litnr*  il*  bulk  of  water,  add 
dilnU  anUcacid  till  a  prectpilale  begin  to  appear,  ibrn  para  a  current  of  carbonic 
anhydride,  fitter,  and  w«ali  Ibe  precipluie  wltb  auier.  alcobol  and  «tber:  tlie 
complete  removal  of  thu  fat  carried  down  with  the  caitcin  preaenia  some  difflcu)- 
tiea.  Ma^Mtc  rulphnle  addiil  t"  ■nturnlioii  uUn  prrcipitatri  vaacio  from  milk; 
■be  precipitalo  ai  thus  1orme<l  i*  rradily  lulublc  on  Ihe  addition  of  water. 

Clabh  III.  OMhA'm 

BnidM  the  native  atbumlna  then  are  u  miralier  of  native  proield*  irbtch  difli'r 
from  Ibealbnmins  in  not  being  aotoblc  in  <li(tilled  water:  ihc.v  nrnl  for  their 
aolntion  tbe  prewncc  of  an  appreciable,  ihoiieh  it  may  be  »  rnnnll,  cjnuntiiy  nf  n 
nentnl  aaline  body,  nuch  aa  aadic  chloride.  Tbuii  lliejr  rcHemble  tliv  ii  I  bum  inn  in 
In  not  being  aolubie  in  diilHIed  water,  but  dilfrr  from  tbein  in  being  aoluble  in 
dilute  sodic  clilorido  or  other  neiitrat  talino  aoluiiona.  Their  general  chnractera 
may  be  «<ated  a*  follow* : 

Tbn  are  insoluble  in  water,  soluble  in  dilute  (1  per  cent.)  lolutiona  ofaodic 
chloride ;  tbey  aie  alio  ooluble  in  dilute  ncid«  and  nlkalie*.  being  changed  on  aolu- 
tioo  into  acid-  and  ftlka]l*albumin  rwpectivelT  unlcM  Ihe  ncid«  and  alkallea  are 
ciceetllnaly  dilute.  The  utiiraiion  with  soliil  Hodic  chloride  of  ibcir  aoluliuae  Ut 
dilutt  aodic  chloride,  prccipitalm  mnt  mcinben  of  thia  vlaM. 

1.  Olobulin  {Criftiallin\. 

If  the  cryMnlline  len*  be  rubbed  up  wttJi  Hne  *and,  extracted  with  water  and 
filtered,  the  Ultnitc  will  be  fouixl  to  contain  at  leiut  iliree  pntleidn.  Dii  paaalng  a 
rurreiil  of  carlioniu  anhydride  a  mjiiom  precipitate  nccura;  thin  ia  globulin, 

Tho  iddilinu  nf  ililiile  iinitic  uid  (o  Iha  DIItbI*  fiocn  lit*  ilobHliTi.  tpvet  ■  pioripilala  nf 
•Ikali>altRiruin !'  nu-t  ih*  fillralD  (rom  llila,  irhaatod.  (IVM  rt  funltnr  pr»cip)Ul«.  iluo  u  Mniin- 

In  iia  ceiwral  reactions  Bhtbalinonrrmjioiida  almoct  exactly  with  the  nest  necn- 
hei«  of  inb  daaa  (panwlooulin  and  ftbnnogcn).  but  ha*  nn  power  In  form  la  pro- 
Biote  the  formation  of  fibrin  in  tloida  ooatftlniDg  the  almve-mentioned  bodin,  and 
IMMCwea  Ibe  following  special  featarea:  1.  AccurdingUiLehnianii.  iiHoiji-ctiiited. 
BCUtfltl  Kilutlona  become  cloudy  on  heating  to  7Jt°L',.aiid  arc  coc^'tilnted  at  Kf  C. 
3.  It  ia  readily  prccifiiiatcd  on  the  additum  of  alcohol.  .Vccording  In  lltrjipe- 
Stjlvt.  it  ia  not  precipilalcd  on  atluration  with  vhIig  chloride,  iffeniblinit  vitellia 
in  tiib  mpML 

Arcertlnt  1o  Kiihna'inrl  ElehwaM*  a  globalin  with  nroporlica  Identical  with  (Ik««  Jwt 
CiTaa  ma)' »  prwiptlatMl  IVoni  diliil*  wrnini  by  lh«  niitioii*  ■'1-litiaa  of  aeell*  ai4d,  Thla 
lady  iitlalwl  by  Wayl'tn  Iw  th«  mma  a*  funelAlxUio  (ribrliinplalllii),  lb*  lallnr  dlUbrlUg 
bmn  H  niily  hj  n  imull  ■■linlxlora  of  Abrtn-fAniMat. 

2.  Parselobulln  {FibriHopUftin). 

£iition.    IIlooil-MTUin  in  diluted  tenfiild  wlih  waitr.and  a  britk  cniml  of 
aofaydriile  ta  paaMil  through  it.  The  lltvi  funned  doudliMMtooa  becama 


» 


•  1tartM*aMa 
>  i^ili  <l  rk; 

'   llrllMlti'  (III  ..._..    , 


CiNMi  d  tB«atif«4U.  mm.,  U 


s.n). 


_.„.  „_.,  Uarfla,  vtn.  a.  I. 


1022 


AffENDIX. 


a  floi-culcQl  |>rL'dpitat«,  wlikb  i»  Hnally  i]ull«  xraniilar.  and  but  »a4ily  lin  lapv 
nttd  br  ilewintatiun  an<]  flluation;  it  dioald  M  washed  on  ttiD  fllur  irich  valat 
4.-r>ii Mining  uirbonic  iidil, 

It  baa  usually  bocii  itatod  tliut  pnnucl'iltultn  nay  hr  separated  frAm  Mruni  by 
Mtufation  with  wxliu  chlunde.  But  Haiuaiant^u' bu  abowo  Ihat  thu  bunly  ta 
part  true,  a  cuu  side  ruble  \ionloa  of  tin-  gluhulia  remnlaing  auprvcipltat«d.  The 
Mpariilion  mtiy.  howcv«r.  bp  cnmplctoly  t-flV-ct*^  by  MturatJoo  with  maga«io  «nl- 
fihalc.  Whon  deli'Tininpcl  by  Ihii  method  the  amount  of  MraglobulJa  in  aanai  i* 
Tory  ooa«idmible,aiiiriuii ting,  iiiwime  auw  ucMitdlnx  to  HammanttMi,  ta  a*  moA 
a*  iM5  per  txaU  {^eck<tlIl^d  r>ti  100  i-.c.  of  aenim).  Tlie  quantity  aeema  to  mj  ia 
illflereDt  aiiimnt''.  tlio  precipitation  bring  much  morv  onmplAlo  in  aMum  (Vdib  ot- 
biood  tban  in  thNt  from  the  blo'id  uf  home*. 

From  il*  KolutiuD  iu  (Iiliit«  nudic  (chloride.  paraf[lobiilin  mar  b«  pre«ipttalo«l  b^ 
a  uurreoc  of  i;arbuiiii:  anhydride  or  tbe  addition  of  HweJi'ny'y  Hitu'r  (Inu  thaa  I 
|)ro  inille)  acetic  acid.  If  ih<.'  acid  is  tirong.  the  pr«cipltat«id  |>ri>t«id  b«cua«i 
iminediatoly  chnn/rd  into  artil-nlbnrnin  (Cloaa  II.,  1 1.  In  pan  mter.  frt*  lh)n 
osyji«n,  paraslubuliD  ii  insolubli-,  but  <m  nhakinff  with  air  at  paanni;  a  eurninl  at 
osygea.  aolutiuu  readily  luket  )»lace  :  fcum  this  it  may  be  r«precipiint«d  by  a  ear 
rent  of  carbonic  anhydnile.  I  W-/(Vir{«  alkalies  diaiolvetliifl  body  without  chann; 
If,  howftvcr,  thnatrrnKtbnf  ihr  .likHti  be  rained  orva  to  I  per  ocnt.  the  panglobuia 
i*  chanjcod  into  alkali -album  in  (Uliun  II.,  i). 

According  to  Kilhae  and  A.  .'^cUmidt  tbe  solmioaH  of  thin  body  iu  wat«t  coa- 
talning  oxyecQ  or  in  ven  dilute  iilkaliiM  are  not  cuaj^ulaled  on  heitiiux.  Tb* 
Hodio  chluriBo  soluliona  (In,  hon-cTcr,  coagulate  whon  hoaMd  to  S&^-'lT  C..'  aai 
if  theKubulancc  itaelfbe  luiipanded  iti  water  and  beaud  to  70°  C>it  ta  eoAgulaled. 
Althoueb  insoluble  in  alcuhol,  Its  soliilluua  are  iritb  difficulty  precipitated  by  thit 
reueot 

Paraiclobulin  occura  not  only  in  blood-«f'runi.  but  it  in  al«o  found  in  wbiMcor- 
piBclea,  in  the  ■irooia  of  red  corpuictcH  (to  noinr  QXtrnt  at  1r«M),  in  coonnlivf 
tiMue.  the  oaraea.  aqueous  liuuor.  lymph,  chyle,  and  icruuR  Huida. 

Fnr  llie  umiirrtnnf  of  flobulln  in  urtu**M  EdleAan*  and  SanaUn. 

8.  Fibrlno(reO' 

The  geueral  reafrlioiiii  of  this  body  ure  ideBttoal  witli  iboie  of  paraslobalia. 
The  niOBi  luatked  diircronco  bctneen  tlie  two  Is  tli«  point  at  which  coacuIatMB  a( 
their  solution*  tnkca  plocn.  Hmnmanitcn^  hn*  sbown  tbat  AbrlnoMD  In  a  l->'i  per 
c60t.  Dolutiun  of  nodjf  chloride  ooa^^tilulu*  at  from  &2''-Ay  C,  WDereu,  m  stated 
above.  paraKlobuUo  (&br{ooplitat!n)  coaKulalen  fint  at  from  68°-70°  C.  Thi>, 
however.  Is  disputed  by  A.  Schmidt,  who  bolda  thai  the  subataiMc  coagulaliitK  at 
Hf-Ai*  (s  not  nbrinoKon,  but  ii  tort  of  noacant  fibrin.  There  la  abu  a  iHail«l 
difi«renco  in  the  precipilabilily  of  tliv  bodio*  by  rodic  chloride^  (8c«  below.) 
Otli«r  ditTerencet  between  tbe  two  mav  be  tbua  enumerated:  In  precipli^w 
fibrogen  by  a  current  of  carbonic  anhydride  tbe  containing  fluid  must  be  moA 
noore  strongly  diluted,  and  Ihc  gas  mu<t  paM  for  a  much  longer  time.  The  pre- 
cipitate thus  obtainea  diflen  from  that  of  pnraflnbulin  in  tliat  it  forma  a  viseeei 
dvpuait.  adhering  more  cloaely  to  the  sidea  and  iiutlom  of  Ihc  oantaining  Teaiel; 
there  la  alao  no  Sooculent  stage  prerlousto  the  visoous  precipitate. 

Pibcinogen  occur*  in  blood,  chyle,  seroua  fluids,  and  in  variwu  traniuilatioaa 
The  rdlationi  of  fibriROKcn  and  paraglobnlin  U>  the  fotinatloD  of  flbrin  hare  ttMa 
diM!UBcd  in  the  text,  p.  49. 

PrejMration.*  Salted  plaama,  oblaiaed  by  cetitrifugatlxing  blood  whriw  coaguls- 
lloa  la  prevented  by  the  addition  of  a  cortain  proportion  of  magumic  nulpbala,  W 
mi  xcd  with  an  aiual  rolunie  of  a  aatuntud  (85.8*  per  cent,  al  14*  C.)'  aoiiUioa  «f 
iHiilic  chloride:  liic  iSbrinogen  la  ihua  precipitated,  while  the  paraglobulln  renaJat 
In  aoluttou.    Tbe  adhering  pluamn  may  be  removed  by  waihiug  with  a  aolntfaiD 

■  l-BUfar*  Afahlr.  M.  itii  >wn>.  &  tu :  B4.  Xtlll.  {IS»\  s.  Si. 

•  tfamnanHcD,  ep.  dL 

•  CmuralbUU  C  nud.  Wl»  I>hr(.  inOb  S.  3V.    Alv>  Artk  r.  kiln.  Jlod..  M.  ta.  8.  <W. 

•  Vlmlinii'i  Arvlilr.  r.;  U   '   iV^  •  llMala  IiSkanAlnBiiiai  rirhsadUonr.    M.  it  tct 
'  a«  ItKianikiMcn,  >    '              r.-j.  tea.  Sal,.  l/'iiMta,  Bar.  Itl.  tdL  x.  Untl,  p.  H.    AI*o  fflaM'i 

AmhJr.  IM-iU.  il!)7*  - iiXskM.  IIBHL&UL 

'  Bgntlal*,  Abu.  CUIa  I'u,^   >.,  vol.  fll.  p.  m. 


A 


CKKMICAI.    IIA3IS   OT    TIIK    A.VIUAl.    HUUY. 


1023 


..  Mtdic  chloride,  and  ibe  libriBCUMO  floally  parified  by  being  4MTeral  tiiUM  il{»- 
MolTcd  Id  Kud  Kprpuipiuttd  lij  •ocUc  eliluride. 

There  I*  no  proof  tlint  thp  whol^  of  tho  mibntivncr  tlin>wn  Hftwn  by  cnrtionlo 
uibydriflo  (ram  diluted  blno'l-itrniin  {■  librin<i|>liuitit' ;  uiilc<<fl  wc  kiinir  Ihnt  K  true 
(Clotiolin  dermd  nf  fibrin  opt  Aitic  pmportioa  miiy  bv  ptopArvd  from  aitiiiii.'  WevI' 
consider*  Ifakl  lli«re  !■  onlr  ouc  dobuliii  In  iteruiii,  which  he  diBrMcteriies  br 
the  nameof  "eeniDi-Klibulln,"  and  rfijnrdK  dbrinopja^iin  a*  a  nitxiure  of  thi* 
bi>dy  with  «  pnilion  of  Hbrin-ffrnirni.  Wc  Icnow  for  certain  (■»  p.  41)  that  the 
wl>i>lf  of  the  fibtinufilnKtic-  (iKcipiiali'.  uicd  In  cuuic  ibe  cuRiculalion  of  «  flbrioo- 
B«auui  dutd,  does  uot  euiei-  luto  ihe  caiiipcnltion  of  the  fibrin  produced :  we  alao 
inow  thai  inch  a  |ir«cipitAlo  may  lo*e  itn  Hbrinoplaetlc  (lowert  without  any 
narked  elinnit''  in  il«  (ti-n^-rnl  rcnciiin*.  It  would  wem  adviwibl*,  ihttrefore.  to 
(peak  of  ihr  •tctuMil  pnjiluccd  by  cnrbuQii.-  iiiihydride  in  dilute  Mrum.  or  by  utu- 
niioB  with  nodic  chloride  in  undiluted  serum,  aa  globulin,  and  to  diitloKuUli  it 
■■  ttbrloopla^tic  i^lobulin  when  it  U  able  to  five  rise  to  tlbrin.  F^brinojten  Biml- 
larly  otieht  be  upoken  of  a«  Rbrinogonou*  globulin.  The  name  eryatallin,  mthor 
than  globulin,  raiftht  then  be  given  to  the  *ub«I«nce  oblainud  from  the  cry*txllin<' 
Ivne. 

I.  MyoelB. 

Iliie  u  Ibe  HiibttniM-e  which  rorma  th«  chief  pn>t«Kl  conaticiient  of  dead,  rigid 
miHCk;  it*  general  proEiertio*  and  node  of  preparation  hare  been  already 
dMcribed  nl  p.  103.  In  tlie  moist  eotidltloa  It  furrna  ii  gelutinoiLi.  elaatic.  clottetl 
luas;  dried,  11  \»  Tcrjr  brittle,  slightly  transparent,  and  elaittic.  From  itsAolulion 
in  »odi<-  chloride  it  W  wrecipitated.  either  by  eltrvme  dilutjoa,  or  by  Mtliratlon 
wiib  (be  solid  Halt.  When  prcclpilaled  by  dilution  und  nubmitted  to  the  pro- 
longed uclion  of  wat«r  mya«in  lotiea  fu  property  of  bein;;  soluble  In  Hulution*  of 
■odic  cbtoride.*  The  aodlc  chloride  iioludoti.  If  expotea  to  a  rising'  louiperature. 
becomes  milky  at  M°  C.  and  givof  a  Hocculent  precipltnte  at  IW  C.  Thia  pr«- 
cipilate  ia.  howoTcr,  no  longer  myoiin,  for  it  in  innoluble  in  a  10  per  cent.  *odic 


chloride  aoluUon,  and  doe*  not,  until  after  many  d&ya'  digeation,  yield  tyntonin 
on  treatmenl  with  hydrochloric  acid  (0.1  per  ceol.),    It  i4.  '     ' 
pratdd  (tee  Clan  y.}. 


In  fact,  voagulaled 


Uyoein  la  eioeeuvely  snliible  in  dilat«  acid«  and  allcalieH.  Advantace  may  be 
takwi  of  ita  eolubility  in  the  fonner  to  extract  it  from  mu«cln.*  Hut  if  (he 
rcagenia  are  at  all  concentrated,  myosin  undergote  in  the  nclof  itolution  a  radical 
ehaoge,  becoming  ia  tlie  one  caae  acid-nlbumTo  or  ayDloQiu.  in  the  other  allcall- 
albumln  (Claw  IT.]. 

UIm  Alirin.  it  nui  In  toin*  nuM  Henemf  oM  hydrogee  dioxiile.  and  oxidiM  guaiaenm  wiUi 
fceiMlton  of  ■  blua  enlor. 

A.  VltaUin. 

Aa  obtained  from  the  rolk  oftf^,  of  which  It  is  the  chief  proteld  eonatltueni. 
vitellin  is  a  while  granular  body,  latoluble  in  water,  bill  very  soluble  in  dilute 
Midic  chloride  •nluticma ;  it  aurpaaaea  myoain  in  thin  re*jiBct,  for  the  noluiioQ  may 
lie  eaiily  filtered,  [in  coiwulatioti  teaiMniture  la  higher  than  that  of  mjoaiii, 
lying,  aeivnliug  lo  Weyl.'Twiween  TO"  C.  and  HO*  C.  Saturation  with  aolid  audic 
chloride  giree  no  precipitate;  In  tlii*  i¥«pecC  it  dlflera  Ctom  moat  olbee  DManbera 
of  thi*  cIm*.  In  _yn]k  of  egg  rilellin  i«  nlwaya  aawKtalod  with,  and  pruliably 
txiati  ID  oombination  with,  the  peculiar  complex  body  lecithin, 

Uanl*.  aB<l  aller  hiia  lloppw-Sayler,  bata  abown  UuU  vMallln  balorfi  ih«  traatinent  ra^Mte 
III  free  il  rmin  larithia  pamema*  ppDpartie*  itntto  diflbranl  frem  otlior  pmUliLi. 

A  theory  haa  boeo  adranoed  that  vitellio  ia  rMlljr  a  complex  body  like  bcmo- 

C*  ibin,  and  on  treatment  with  olcohi^  aplita  np  into  eawubited  proteld  aad 
ithin.  When  well  puriSed  It  cenU^n*  0.76  per  cent,  auiphur,  but  no  phoa- 
pboroa.  Dilute  aci<lii  or  alkallee  readily  conTerl  it  lu  ita  uneot^^lated  form  into 
nmeaabeiof  Claw  II. 


•  Kakn>>ao<IKI«li<rald.loc.  eti.  i  tnl  vlt 

■  Wf7l  /r^IBwIir.  I  Pbrilol.  CUrm.  n't  1.  ni7'>.  E.  TT. 

'  [laiilkinkjr.  Zi-ntehr  t  pk; 4at.  Cbcm.,  M.  t.  a«li,  a  IM. 


•(*.*b. 


1024  Al'i'ESIIlX. 

Fr?Tny  ami  Val^ncieimea'  have  described  a  aeriea  of  proleMa.  viz.,  irhtbin.  irhlhtdiD.ftr, 
derived  from  fjah  and  ampliibia.  Tbey  appear  M  be  either  idemlcal  irilh,  or  ctowljillicil 
to,  vJteLlin. 

PrtparaUon.  Yollc  of  pgg  is  treated  nith  succeagtve  i^uantiliea  of  ether  as  long 
88  this  e^tlractB  any  yellow  coloring  matter;  the  residue  isdiaeolved  id  modtratelT 
stroag  (10  per  cent.)  sodic  chloride  solution,  and  filtered.  The  filtrate  on  falling 
into  a  lar^e  escees  of  water  la  precipitated.  In  this  xtate  it  is  mixed  with  lecithin 
and  nucleiD,  and  in  order  to  free  il  from  these  it  was  usuallj  treated  with  slcoli''!. 
Tbia,  as  above  stated,  entirety  changes  the  rilellin  into  tt  coagulated  form.  It 
Beems  probable  that  the  separation  of  vitellin  from  the  other  bodies  with  which  it 
ie  mixed  in  the  yolk  of  egg  may  be  effected  by  precipitating  the  aodic  chloiiile 
aoluiion  by  the  addition  ot  excess  of  water ;  the  precipitate  is  then  rediE>eolved  in 
10  per  cent,  solution  of  sodic  chloride,  and  tbe  process  repeated  as  rapidlr  as  pos- 
sible. 

6.  Olobln. 

GLobin.  staled  by  Prejer'  to  be  the  proleid  reaidue  of  the  complex  body  hvinoglobiD  \itt 
p.  457),  ought  probably  to  bo  congidered  aa  an  otillyiog  member  of  this  itIbm.  It  ia.howeKr. 
not  readily  soluble  eillier  in  dilute  acide  or  sodic  chloride  aolutiona.  It  is  ni<l  lo  be  abto- 
lutely  free  from  n»li. 

Class  IV.    FUmn. 

Insoluble  in  water  and  dilute  sodic  chloride  aolations;  soluble,  with  difficnlu, 
in  dilute  acids  and  alkalies,  and  more  concentrated  neutral  saline  Bolutions. 

Fibrin,  as  ordinarily  obtained,  exhibits  a  filamentous  structure,  the  component 
threads  possessing  an  elasticity  much  greater  than  that  of  any  other  known  solid 
proteid. 

If  nlliiwed  to  form  gradually  in  large  maesee,  the  fitamentflua  Etructure  is  not  si  nitin- 
able,  and  H  rcwniMes  in  Ihi^  foriti  pure  India-rubber.  Buch  lumps  of  flbrin  are  fiplJf 
of  being  p|dit  iti  uiiy  direi'lion.  aiid  do  definite  arrangemeiil  of  parallel  bundles  of  ]ibrH<^Ti 
be  made  out. 

At  ordinary  temperature  fibrin  is  insoluble  in  water,  being  dissolved  on  I  vat  tety 
high  temperatures,  and  then  undergoing  a  complete  change  in  its  characters,  la 
hydrtjcbioric  solutions  of  1-5  per  cent,  fibrin  swells  up  and  becomes  transparent. 
but  is  not  dii'solvcd.'  In  this  condition  the  mere  removal  of  the  acid  by  an  excrta 
of  water,  neutralization ,  or  tbe  addition  of  some  salt,  causes  a  return  to  the  origi- 
nal stRtc.  If,  however,  tbe  acid  beallovred  to  act  for  many  days  at  ordinary  fem- 
peraturci",  or  lor  a  few  hours  at  40°-00°  C,  solution  takes  place,  and  the  reaulting 
proteid  i^  syntonin.  In  dilute  alkalies  and  ammonia,  fibrin  is  much  more  readil.r 
soluble,  thiiufrh  in  thiM  cHse  also  ihe  solution  is  greatly  aided  by  wanning :  the 
resulting  fluid  (oniuiiiH  no  longer  fibrin,  but  Bikali-alDumin.  This  property  i:* 
not  disliniilv  cliiiraeterihtic  of  fibrin,  allhtiugh  it  diesolvei)  peibaps  miTc  readily 
in  both  dilute  aciiis  iind  iilkuliea  than  do  coagulated  proieids.  None  of  tfae>e 
solutions  cati  be  toHgulated  on  heating,  wbiih  is  intelligible  when  it  is  remem- 
bered that  lliey  no  longer  contain  fibrin,  but  either  acid-  or  alkali-album  in.  Id 
flddhioii  to  tbe  above,  fibrin  is  soluble,  though  with  difficulty  and  only  after  x 
con.-<ideri)blc  time,  in  10  per  cent,  solutions  of  sodic  chloride,  potassic  nitrate,  or 
sodic  jiulpliati-.  the  solution  being  olt«n  accompanied  by  putrefactive  ehanp'. 
TbcfC  ?oluii<iiis  iiiiiybe  coBgulateil  by  a  temperature  of  eO'C,  and  are  precipitaitd 
by  dilution  niib  water  ur  saturation  with  solid  aodic  chloride;  in  fact,  by  the 
action  of  ibe  reutrul  saline  solutions  tbe  fibrin  has  become  converted  into  a  body 
exiecdiiiKly  like  uiyocin  or  globulin.' 

(Ill  ii;iiiti<iii  <if  fibrin  a  residue  or  inorganic  matter  is  always  obtained  ;  iti^. 
hoivf  viT,  c<in-.idefed  timt  Hiilpliur  is  the  oiily  one  of  these  elements  which  entfrs 
I'weiitiHlly  iiilii  its  lonii  or-itinn.  In  other  respects  fibrin  corresponds  entirely  m 
pener:il  compcisilion  "ilh  tbe  other  proteids. 

I  ri.uic'i.  li^'iid.,  T.  \.s'i\iLi.  yy.  Ir^:>,  .'li'i. 

-' Vvil  <.|i  .ii.,S.7i,  >  Die  Bluitryftalle  (I'TIK  5.  I'lV 

•  r.  .ii.|.:.  1 1-  -I.IM11..U  in^LV.  himi-n-t,  inkt  [.lnei>  if  ihi-  fibrtn,  a.«  1^  frenner.ilj-  ll>e  en*.  .imiaitsV.v 

"  i.nui:,r,  1 1.1.  n.n.t.,  T,  Iwis.  1 1-7 II.  [..  iSi. 


\ 


cnsuicAL  Basis  uf  tub  xsiual  jjout.         102S 

8u«|it>iute(l  in  water  and  kotil«d  (o  TO"  0„  il  toum  iU  olacticitf  luid  beco4DM 
Opaqiip;  it  i*  tbcn  indinlinjpiUhnblv  ftom  (>tli«r  COHgnlatcil  pmloida. 

A  pamlur  pn>p*rt]r  or  (hi*  Imdr  wniiiia  yH  bi  Ixi  iiiiintii>ni><l.  tit..  il>  (nwtr  at  ilMom* 
,  peung  hjdn>SDii  dtpxtda.     Pi«u  of  (Ibrlu  pUiwi  In  Ihii  tlui-l.  though  themnWu  uiular- 

Kins  *a<b>angc>  tocoi  braiina  cnrciwl  irilh  bubbln  itt oxygen:  and  puaiacum  ii turnvd bliM 
(twin  i»  pnMDM  or  hydntvti  iKoiMa  ur  aaoalaad  torpantlaa. 

Pmaration.  By  vignmiuly  utimng  blood  wiih  ii  Immile  of  litigm  and  thoi 
wuhinv  with  wulcr  until  it  U  iiuili!  wiiil«.  IT  requirMl  uerfeolly  pur«  and  colo^ 
lew  It  •faould  be  preimred  from  pla-cua  free  from  curpiudw.  If  the  blood,  before 
ahrrin;.  be  dllaird  witli  an  ojiml  biiik  of  ivattr.  the  culiiMyiuoDt  wuliing  of  the 
Abrin  i»  much  fAoititntrd,  and  ii  mnj  reiidily  be  obtitincd  ijulii-  wbile.  Adj*  Hdb«- 
fcnt  fat»  may  be  rcniorrd  by  clhrr. 

Wbca  globulio,  luyuain.  and  llbriii  are  iwin|iared  «wh  with  Uic  other,  il  nlll  be 
■ecu  thai  ibey  form  A  Mrlca  in  which  myoela  Is  iatermedialc  iietween  globulin 
Bod  fibrin.  Globulin  ia  «xceMivel;  M)la&l«  in  even  the  mint  dilute  acid*  Hud 
alkitliea:  Rbrin  ia  ■ImoKi  in«-ilubIo  in  tbne;  while  myoain.  thi>ui;b  luoru  wiluble 
tban  fibrin,  ia  Ima  naluMu  than  globulin.  Qlobulin  again  diaaolTW  with  the 
CreBteal  eoae  in  »  rerv  dilute  wluiioo  of  eodic  chloride.  Myosin,  on  the  other 
MDil,  dlnolvea  wltli  difficulty  ;  it  Is  much  more  Bolnble  in  alO  per  c«nt.  than  in 
a  I  percent,  dilution  nf  fodic  chloride;  and  ctoo  in  a  10  per  cent,  tolulion  tin- 
Dijmiii  eiD  hardly  be  said  to  be  diaudveil,  ao  vucid  ia  the  rraultins  fluid  and  witli 
awh  diSculty  doM  it  (liter,  fibrin  again  diaaulrts  with  grrat  difflculiy  Hud  very 
■lowly  la  even  a  lu  per  cent.  Huluiinn  of  nudic  chloride,  and  in  a  I  jicr  moU  tolu> 
tlon  it  la  practically  insoluble.  Wh«n  it  iit  rcmrmbercd  that  libna  and  niyoain 
ar*.  both  of  them,  the  nvulu  of  criii){iilntinn,  their  sirailarily  in  inlelli|nbl«, 
Myoain  ia  in  fact  a  wiiuewhal  more  iiiluble  form  of  fibrin,  di-pmited  not  in  threada 
or  ttliirnenCa  but  in  clunipa  and  niaaieB. 

V  Cli«»  V.     Owsrii/aiyrf  Pmltid*. 

Thew  aro  inaolublo  in  wntrr.  dilute  ncida  and  alkaliea.  and  neutnJ  taline  mIu- 
tioAH  of  all  sirenetha.  In  fact,  they  are  really  aoluble  only  in  Atroas  acids  and 
■Lroafc  alkalit*,  though  prnloni^ed  action  of  ttivn  dilute  nciiU  and  dkalles  will 
eflbct  aoene  eolution.  especiHllv  ut  bi^h  tern peratu tea.  MarinK  aolntioii  in  atrong 
aclda  a&d  alkalltft  a  detttruotive  decoinjioaitloii  cakea  ptaee,  but  >ome  amount  ^ 
acid-  or  alkali-albu^iia  is  nlwayi  produced. 

Vary  little  i*  kDonm  of  the  cbrmiinl  i-hnractrrinira  of  ibis  claw.  Tliey  ars 
produced  by  beatiug  loTCi'C..  nolution*  of  rjtg-  or  aeiym'albumin.  globiiUna,  aiia- 
pended  in  water  or  dfiaalred  in  aalliie  M>Iutluua ;  by  boiling  for  n  ihort  tiiuo  fllwin 
■uapendcd  in  water  or  dlMolved  in  saline  aolutlona.  or  precijiitated  acid-  and 
alkali  ■albumin  ■utpciided  in  wster.  Tbe^  are  readily  converted  at  the  (cnipera- 
turc  of  llir  body  into  pi-plonea.  by  the  action  of  ganlric  juice  ia  ao  acid,  or  oi  pao- 
cr«alic  juice  !□  an  alkaline  medium. 

All  [iroceldN  in  itolutioas  are  precipitated  by  an  cicea*  of  atrong  alcohol.  If  the 
prtcipitant  be  rapidly  remoTcd  they  arc  aenin  «ohible  in  water,  but  If  ili«  nrecipi- 
tate<l  pr<itwda  are  >ubjrct<vl  for  aomo  time  to  tbr  action  of  the  alcohol  tuey  are, 
with  the  e^cceptiun  of  pcfitoun,  coagulati^il  and  lu*«  Ibcir  wilubility.  It  appears, 
however,  thui  t]ie  urotctdii  conlalnedlii  th«  Hietiruoe'gtaina  uf  plant*  are  excecd- 
lugly  rcfiittiint  to  this  coagulating  action  of  alcohol,' 

It  •a«aM  warmly  nerMMty  M  point  «ui  (li*  didiEioliaii  Id  ilia  u«taf  lh«  word  "ooajrala- 
Iku  "  ai  applied  in  lilood-  ce  mtualo-iiliunui  on  ili«  una  luiid  ami  tu  Ui«  KUoa  of  bnu  and 
almliol  npou  protoida  oa  the  otiicr.  The  itiflMwnoc  ia  olmoiu  when  it  ia  rauMwiWwd  thai 
Ib  tlin  flni  (««a  the eoacuUliuu  ImJ*  lo  (ko  fannatMU  of  Abriu  (CIbm  iv.t.ar  ■ny«aia  iCia* 
iii.l.aii4  Uist  UioM  IhhIIw  ni*y  then  fuMkor  iw  eoagulslcil  liy  iMatar  akotwl  ■•  iliirfHwl 
abev*. 

Ci-Aat)  Vt.     P^toata. 

Vtry  aoluble  in  water,  and  not  i>re«ipltal«<l  fVutn  tfaelr  aqneou*  aottitioiM  by  tlie 
addition  of  acid*  'it  alkaltea,  or  uy  boiling.  Iiuoluble  in  akohol,  they  are  pre- 
cipitated wUh  didlrully  by  thi»  reagent,  and  are  ancbaaged  iu  the  procwa;  Uie; 


i*»»\\i»^Kmm,t4  nijrdol.,  mL  ML  (i  ] 
06 


i 


1026 


APFKNUIX. 


difler  from  nil  oiher  |>n>lcid*  in  not  Lriiij;  CM^Uted  by  pralaagcd  «9 
skobul.    Tbof  are  not  precii>Uuivil  by  luprlc  anlpbMv.  ftme  chlari4*, ' 


:ij>ttuivil  tiy  L'upric  aniptiMv.  Rnte  chiarul*,  or,  n 
in  th«  liMtencei  to  be  iiieniionti]  jiteMntly,  bv  {K)UHic  ferrocyuniile.  and  . 
acid.  In  thma  point*  tbr.v  dilfrr  fnat  mo«l  oilier  proieids.  On  lb«  oUicr  I 
prei-i|>itiitii>n  i*  caiwcd  bv  rblorino,  iodino,  tnnnin,  mercuric  chloride,  uitrkharf 
nipicurv  aiid  vilvn',  and  Wli  uueiiiUs  of  lend ;  mIho  by  bilo-Bdili  in  an  Mcid  aola- 
lloii.  Id  c'lmmou  witli  ail  pruleids.  Ibeue  bodiai  poMsna  •pecifio  In-fo  rolatorf 
fMwer  over  polnriRcd  light;  but  tbej  ditTcr  from  all  ollitr  proteidii  in  itie  fact  Uiat 
boilinK  priKlui-n  no  rhanKc  in  lh<i  ■nuiunt  of  rnlntion. 

A  Kilutitiu  uf  |)e|'i(iim,  mixed  iriib  a  alron);  wiluiinn  of  cauatic  potaab,  gimkoa 
the  addition  ><f  a  mrrr  Inifr  of  (.-uprlc  eulplinl^.  a  /liat  color.  An  rxceM  of  tb« 
cnprir  uitl  tiri»  :i  viold  enlor.  whtch  doeji^rm  in  titic  on  boitine,  in  fact  th»  ordl- 
niirj  proteicrr«tcti(>ii.  Other  pmlrid*  hiin|<ty  givn  (h«>  viol«(  color.  But  tbei 
cburucltTiiitlL-  feature  of  peptone*  irt  their  tcliitivrly  Krtat  diflbailiillty,  m  i 
which  they  aloue.  ul  all  the  pruteids.  may  bu  aaid  to  poaanv.  aince  all  otiMC  J 
of  prol«4ds  pass  through  membmiiea  irith  th«  grealnt  dUHctilly,  If  at  all. 

Tho  diDHiiitrilitT  nf  peiilouM  la,  bowevor.  ■baotaLsly  amall  •«  cnm|ia«Td  <ttlh  Uial  nf  •.,. 
lalliao  tiodla**iichta*niftFoli1i)rid«;  in  llwlM>1ution«of  pvpUmw may  be  fr<wl  tmtm  ^ui, 
dlalyiti.  a  prwwH  euiployal  ni  llialr  j<n>panitloii. 

Notwltbntandiiig  their  ]>rubabl«  furaiaiioii  in  targe  ()unntiti«*  in  ibe  tfawtiacfa  and 
IntMlinc.  to  judge  from  ibe  reaulla  of  aitiAclal  ufgoilloti.  a  very  Mnall  oaantili 
only  caa  be  found  in  the  euiitonta  of  theao  organ*.    Ttiry  are  probably  i^Mofh 
iiK  (nun  OH  rririned.     Another  point  of  intvrcal  in  llirir  reconvrn>>on   iotii  o|' 
fornm  of  prolf  ids,  niiioe  ihii  must  oei'Ur  to  n  Kreat  cxtQiit  in  the  body.     We  \ 
liowever,  nit  yet  ignorant  of  ihe  manner  in  whlcb  this  reverse  cbmii.'!-  i>  I'lTx, 

fyodirlion.    All  proteida,  wiUi  the  ext«f>lioD  of  lardaoeiii  {-' - 
poptonea  (and  other  prodactaj  on  lrraiiii«nt  irith  acid  giwtriv     i  ji| 

creatic  juito  uhhiI  readily  at  the  Icmpcmliiie  of  tbe  human  body.     IVptonnl 
likewbe  pniducod,  in  die  ubaunceuf  pe[Hin  and  trypain,  by  tbe  action  <•(  •'" 
and  inodotntely  strong  acids  ii[  ni«diuin  temperatures.  hIm  by  the  acUoo  of  dli 
water  at  high  tcmneralures  under  pr«wiure.     Fur  Tarioua  meUwda  of  prv)u 
iin,  see  Maly,*  Adnnikiewicc.'  Henotnger,'  and  i^kelbario^* 


peptfint 


Iba  vUuD  fll 


Ii  ai-iiean  poaible  (o  renlilain  ordinary  cdM^iilalile  proUU*  tnmi  peptonM  by 
«lllier  pruluQctil  lioalint  Uf  I4(t°-1!0*  C.  ot  of'Miy^tMig  agoiiu.* 

Ko  diflirreooe  in  percrntage  composilinn  bctweeo  p^itoaeaand  tho  proUM  tna 
whicb  they  are  foruied  lini.  at  pren-ni,  been  deflniiely  etitablWbed, 

We  have  u*^d  the  pbrate  "  [leploneA"  in  the  ptaral  nunber  becauae  ir*  liaTe 
rcitaoii  l[>  think  llmt  more  than  one  kind  of  oeptono  exwla.  MeiuneT*  UMcriM 
ilirce  peptonni.  Qniniog  them  ropectiitely  A-  It-  and  C-pApUne.  He  di»iioguiihri 
tlicm  M  follow! :  A-|>ept(ii)e  is  precipitated  from  itaatpieoaa  aolutioni  by  eoficM. 
tinted  nitric  acid,  and  alao  by  [lolaMic  ferrocyanide  in  tbe  prcwuice  of  even  wtak 
aeello  add.  B-jieptoae  ia  not  precipitated  by  concentrattd  nitric  ai-ld.  nor  wIU 
lioUMtc  ftrrocyanide  (pre  a  precipitate  iinleM  a  oamidcrable  •iniintiiy  of  airotif 
ac«4ic  acid  be  added  at  the  aanie  time.  C-neptooe  la  precipiiuted  neillice  by  uitHe 
acid  nor  by  pol4nlc  ferrocyanide  and  acetic  acid,  wbatcTttr  l>e  ibe  strength  of  iho 
acetic  acid,  tn  place,  however,  of  apeakingnf  all  ihraa  m  pei>tonea.  It  ia  better  ■• 
consider  C-pei>tone  aa  tho  only  real  peptone,  and  Ibe  A-  ana  ll  peptone*  ai>  not 
peptone*  at  all.  Nevertbelwa'we  have  reason,  from  the  reaearchea  of  Kflbae,  Ur 
apeak  of  more  ihnn  one  peptone,  vi^..  of  u  bemipeplone  wbicb  ia  oapabl*  BMiiT 
ue  AciioD  of  tryjxiln  of  being  converted  into  loucin  and  tyrodo.  and  nf  Uk  aiili- 
|tepl<>ne  which  reiiMii  micb  n  de«i>mp<i»ition.  Tbe  natne  ■oti))rptiine  is  riven  li> 
the  latter  on  account  of  ibiii  rerintance  wblch  It  ulfers  toward  Irytuiu ;  thin  uaar 
beat i  peptone,  given  lo  the  former,  aignlflea  that  this  peptooe  is  (be  twin  or  0N> 
tvlallve  half  of  antipeplone. 

We  have  iwen  (p.  311)  that  when  any  proteid  i>  digtated  wilb  popaln,  what  n 

1  pai,p.r  - 

•  I^IbS-:  ".i."    M 

•Iwln.s..  Ivt  l^piinvn.  I^rit.  ISJN, 

•  I^*j^i'i  Ai'ti  ,  1^1   iin   .:•.•■.-(.  t',  I".'". 

>  t(«ii>liic<r.  lor.  n\. ;  IlLiOnrl.itf.  Zgluoli.  t  phydal.  Ckam.,  fid.  It.  11*1*1.  9.  aW:  rtkdtalBB. 
tor.  ell. 

•  ZrttMb  (. rat. Uta.  B4*.m.,iW.,a..alL.a.ilv 


OBBUIOAL  BABIB  OF   THE   ANIUJIL  BODY. 


102T 


I 


e 


nar  pivllinlnnrilir  call  n  by-product  makwtta  appenrnuee.  TbU  by-product  which 
bu  mniiy  riiM-tnblancw  lo  acid-albumin  or  ■vitwitn,  appMrin^  im  a  neulrallutlon 
pKrifiilah-  wilublp  in  dilute  luldii  ami  atkalim  but  inanliiblv  tn  dinlillcd  water,  ia 
fanrrally  <pK»kcn  of  no  |«rapepto«i(>,  Aoctirdiuc  to  Flakier'  thi>  ii«utraIiulioii 
precipilalf  in  ei|i«c'iatly  abuntunt  if  tlic  i>epslu  be  pr«vlotulv  miHliG«d  by  npo- 
aur*  to  B  ieinp«ratur«  of  Vi""  to  W  C.  The  petxJn  thua  modified  la  apobeo  of  bv 
Pinkler  aa  "  tonppnaln.  '  Many  autlmn  rcmrd  pa»|H<pt»n«.  ayatonin.  Kod  aold- 
alltumin  iiK  hfiag  ihc  nHmo  thine.  MpiwtiiT.  howoT«r,  inive  tb«  naiDe  panpfptone 
to  B  buily.  irhit-h  Deed  out  tuiA  probalilv  doM  not  make  lla  Kppearanc*  during 
BonaKl  nuiural  dlgmlan  or  during  iirlilk-ial  dlgeatlon  with  a  thoroughly  aclivo 
Mpttto.  bul  wbii'b  k«  formed  nhcii  protciiU  ari^  aubj«ct«(l  to  the  HctloR  of  weak 
nydrocbloric  acid.  ?iih<-r  alone  or  in  i.i>ninitnv  wllh  un  impcrfrr.Cly  .vUng  ])ep«tD, 
and  which  in  cirlaio  rhiiniclcn  i«  quilt?  iiistilti-t  rrum  ordinury  ■viilimin  or  acid- 
albumin,  [u  diBliii[;uiMhing  ft-aiurc  that  it  caiinoi  be  chaii|^  intu  peptone  by 
thi'  action  of  eren  the  nxMl  <.>iiortfeiii.'  pvptin.  though  it  i*  readily  «u  ci>DT«rtMl 
under  the  Influence  of  tryiwin  ;  othtrwlsr  it  vrry  rlo*<-ly  MHunblea  ayiitonlD.  VV'e 
have  here  aii  iedication  that  the  niintilc  chnnii.'U'ni  br  which  we  hiavo  described 
acid-albumin  may  be  borne  by  budics  liariiijr  inaiked  ailTercncM  from  each  other. 
The  r«M«rclia  of  KQbae*  biive  thrown  an  lmi>onaat  lleht  ou  thoie  iliffemiocik 
The  fkutdamenlal  notion  of  Kllbne'«  view  b  that  an  ordinary  native  albuiuln  at 
Sbrin  oonlAin*  within  itHcIf  iwo  rfoidiim,  which  he  calU  rrnpectivoly  an  aatl- 
r«iilae  and  a  homi'miduc.  The  renull  of  either  mplic  or  Irvptir  digution  ia  Ut 
wfiit  ap  lli«  albumin  or  llbrin.  mid  to  prodooe  on  the  pwrt  oftlie  unli-rc«idue  anti- 
peptone,  and  on  the  part  of  the  hemi-realdne  faemipeptone,  the  latter  being  di«- 
tlagnlahed  from  the  former  by  ita  bcipg  auMvptible  of  fbrther  change  by  trypUc 
dinMioti  into  leudn.  tyrwn.  etc.  AntipepboiM  lemaiiw  aa  antipeplone  oven 
wneo  placed  under  the  action  of  the  moal  powerful  trypatn.  providnd  pntrofactivt 
clianm  do  not  In  terrene. 

Benra  the  ala^  of  peptone  (wbethcr  unti-  or  liemi-l  ia  reached,  there  U  no 
iaicriBedlate  atage  correspond! nj;  In  the  formation  of  Kyntonin,  In  both  nonual 
Miplic  and  trvpiic  diKoticiti  antipeptone  in  prccMlnl  by  an  aotJ-albiimoMt,  and 
hcnitpcptnnc  ny  a  hi-mi-iillmm'ike.  Of  tboM'  the  anti-albumoae  iicloMly  related 
to  nyntonin,  aitd  liiu  hithcrt^i  been  regardtO  a*  ayulunin.  The  bemi-albumoa* 
liM  not  been  ao  fre<iuenlly  ubaerv^ ;  it  waa.  however,  boUled  by  Meiauifr;  il  ia 
appar«nllr  the  body  called  by  him  A-peploiie.  It  pomeawa aeveral  peculiar  IW 
tureii.  If  its  solutions  are  hemed  ih<.'y  pariinlly  coagulate  at  about  00*'-43°C.; 
the  precipitate  ia  soluble  at  abiiut  TO"  ('.  and  is  re -precipitated  ^  the  temperature 
■gain  (alls.  It  s1«>  yield*  a  precipitate  with  nitric  acid  and  putii»ic  fcrnicyanide 
and  this  aliM)  U  iiuliibk-  ai  the  hlgliM  leuiperntiire.  r«-preciiiitatiug  on  cooline-  In 
thMe  reajxcis  it  cliwely  rc^embtoa  a  proleid  body  obterriMi  hv  Bonce-.Tones  in  the 
orin*  of  miromalnciB.'  It  approaehae  myown  in  beinx  rcailily  koIuIiIo  in  a  10  jier 
cent-  aolution  of  mdic  chloride. 

If.  hiiwerer,  nibumiu  bo  dicealed  wllh  InaulSclcnl  or  with  loiiierfectly  active 

Eiptin.  or  Hiinply  with  dilute  Hydrochloric  acid  at  W  C,  aull-albuiDoee  b  not 
rm«<l.  bill  in  iU  place  a  body  makni  it*  appearanco  which  KUhiM  calls  antl- 
■Ibnmai*.'  Its  i-.hBrac.teriKtic  properly  in  thiit  it  cannot  bo  oonvertad  by  pevtic 
difcottion  into  peptone,  ihnueh  it  can  be  to  chiinged  by  iryptic  digeation.  11  b 
in  fact  the  purapeptoiie  of  .Melwoer. 

Il  WMf  pfvliapa  ne  adviuiblo,  now  that  Meissner's  pampeptone  ia  cleared  up,  lo 
rcMW*  Ui«  name  parapcptone  for  the  initiiil  producu  nt  both  peptic  and  Iryptic 
diK«*tion.  and  lo  apaak  of  anti-albumoie  and  iienii-alburn'»r  a*  bcinx  '^'^^h  parm- 
peptones.  But  in  thia  seuae  perspcpione  will  be  uu  iotenuedlBio  and  not  a  col- 
lateral product  of  dlgeetlon. 

MeiMiier  also  desoribed  a  particularly  jnaoluble  form  of  hia  parspeptone  ai 
i^jnpcptone,  and  another  intermrdiHie  pniiluet  an  nietapcfitaDe ;  but  further  invas- 
tuetiOD  of  both  Ihiw;  licidle*.  an  wdl  a.i  hi*  llpeptuoe.  )■  noceauuy.  Under  the 
inilaence  ofdilute  bydr-x^bloric  ncid,  Buti-ulbitm»l«  becomes  chnoged  iuto  a  body 
irbkh  Kfibnecallii  auii-altiunild.and  »lilch  leemi  idtnliciil  nlih  the  very  liiaolnble 
inotrid  described  by  SchiiUenberger  as  "  fauDipnitein,"  and  probably  witb  Mebe- 

'  PtuirVi  .trcblT.  ilT  (ISWi.  B  i» 
■  itelji  ■  ihi-n  Miminl  al  itaae  liu  H  ytt  b«a  PiiMlifcul 
IUI<lill>m.  Ikl.  I.  Ilffi  t,  tin. 
•  aa  albduiai*  noM  not  be  ranAniiKlRl  wlUi  an  allmailnaie 


VarluudL  d.  SuutWaL-OML  V«fDla, 


1028 


APPKXDIX. 


n«r'«  dnpeptnue.  Tlie  Mm*  bodr  It  produoed  lU  oac«  in  eompknv  with  i, 
b«1oDgine  lo  Uio  beini-grotip  by  the  action  of  S  to  5  por  cent.  siil|>burte  i 
native  nlDdnim  or  6lirJn.  Tlio  following  teblm  'linw  the  relaiinDo  mkI  gamia  of 
tho  bodicm  vro  hare  jiwt  dcacHbol.  The  teverat  praducta  (aatijwfiUiaA,  vtc-)  art 
Kivcn  ia  duplicaie.  oa  the  hy|Kith««b(wlikl),  thoitj^b  not  proved,  la  |>n>babl«)  that 
tbe  ubangM  of  dige»ili>ii  are  casenUally  hydrolytic  chnii|^.'  atcompanM  bf  a 
deduplication;  thai,  jiut  a»  a  moloculvof  o'lorch  ■pliln  up  into  at  iMat  iwa  ttul^ 
cu1o«  of  dulrvae,  or  a*  a  Dioltculc  of  can«-augar  «plil>>  up  tolo  a  molMala  «r 
dcatromj  and  a  molecule  nf  lerulone,  to  a  niolMuto  or  antialbuiunae.  far  Inaiuot, 
■pliu  up  into  two  molevulen  o{  aoUpepton«,  and  to  oo.  But  tli«  «bol«  •ch«B*  tt 
or  courae  only  prOTiaional. 


i 


DRCOMroniTiox  or  Pkorsioa  bt  Diosnios. 
Atbonitn. 


»  . 

i  I  Aniipopton*. 


AiitlalliUBiiMaL  HsmUlbuiiioM^ 

Antlp»|itan*.  Swnipqitoiio.  ll*iiitp*ptMia. 


LtudD.     Tytvia,    L«ai^ii.        lyroalB, 
•l4k  ate. 


DBOnWPWITIOK  BX   AclDB. 

1. 

By  OM  fM-  Mat.  UCl  at  4U"  a 

AlbHiBin. 


'I 


AsilalbuiiMtCi 

I 
AaUaHmnild. 


HcnialbnmM^. 


Jleniipepcon*. 


UcmipoptoM. 


3. 


By  IS  par  cant.  BfiiU  at  106°  a 
Album  la. 


Antlalbuniid. 


HaaiaJbvDKMfL 


ll*nilp»pta»«. 
Ltuoln,  Tjivaiat  «(c 


llaiuip>p*n»>] 

I 

LvurlB,  Tjnnutl 


Clik  VII.  Lardacri't,  or  Iht  to-called  AmfloU  £MM<mw. 

Tbe  itubMaiii-«  to  nbiL-b  th«  above  oaxue  la  applied  U  fbund  u  a  patlKdMlal 
deposit  ill  th*>  spleen  aiid  liver,  alao  in  numerouH  otber  or^na,  aueh  aa  tbe  bim- 
Tesaela,  kiilneys,  lung*,  vie. 
It  ia  inMtut>lc  in  water,  dilute  ni'idn.  nnd  nlknlj*,  and  neutral  •aliof  aoIaiioBa 
In  oentotiroal  oompoailiun  it  ia  almud  idculii;al  iriib  otber  protdd*,'  vtf. : 


0.and8. 
M.4 


B. 

7.0 


N. 


C. 


The  Bulpbut  iu  thia  bodjr  ezbta  In  the  onldlwd  atate,  for  boHine  with  cauiik 
potaab  glv<a  no  mljihide  ol  the  alkali.  Tbe  above  reaulta  of  analyua  wuuld  Uad 
at  ORG*  10  tbe  raokins  of  Urdaci^in  ax  a  proteid,  iinil  Ibta  i*  *tr(>ng1;r  ftup|<orted  In 
Other  Cuia.  Dtrons  ny(lnKbli>ric  a^iid  c«iivvrt«  ii  into  acid -albumin,  and  wutir 
alkalies  Into  alkali-alMinin.  On  tbe  other  hnrid.  it  cxhibila  the  followiojrmajM 
dilTbreucea  from  other  i>rot«ida :  It  wholly  rtoiitB  the  acUoo  of  ordinary  dicwb'* 
Ituida ;  it  i*  colored  red,  not  yellow,  by  lo>lf ne,  and  *IoIet  or  pure  blue  by  the JniM 

)  IlKinliiatr.  to*.  dL  p.  Ml 

•  V,  AshmldL  ADii.  il.  Cb«ni,  a.  Phano.,  Ud.  ex.  S.  :U«.  aad  PtMxdob  a.  Xelrnt*.  VtMbmt 
AkMt.  iu.  nl.  8.  W. 


CHBHICAL    BASIS    OF    TOK    ANIMAL    BODY. 


1029 


» 


I 


i 


* 


Mtioa  of  iodiiw  and  mlphnrir  ■cid.  Vcam  tboo  lant  rcMli'ina  it  his  dNlvcil  one 
of  ItsBUBCa,  "amjioid. '  tliouKh  (hi*  ii  eviilevlly  badly  cbMen;  fof  bMooly  does 
it  dlfl!^  from  tti«  HUieh  gn^up  la  cum pu«i lion,  bui  by  ni>  nieajia  c«n  It  b«  ouii verted 
iolo  f>ii)csr:  (bfci  latter  io  one  of  ibi-  iTiirUl  tnU  fnr  n  Inir  mfitibcr  of  th«  carliD- 
hydrate  |[rou|<.  According  to  llriu^hl '  nnd  t^^rnil,'  lUiiHn-viDlct  luirtLyl-aoiliuJ 
coloni  lardai-cnun  tiiou«  ruiy  red,  but  lound  liauie  blue. 

Tba  sijon  nwBiiMiiiiiI  •Invv,  ■«  ti*iiig  pro<liu«l  by  Iodine  and  mlplmrlc  add.  an  mneh 
dcantr  aad  lirifbter  ■'heo  Iho  reagents  arc  applldl  to  Ih*  puiilloi)  Urrlireiii.  Whmi  Iba 
ivsfBnU  aia  ■pplird  l»  (ha  Finds  anbttann)  in  iu  iwirinal  jnaiiioii  iu  (K*  iiiauM,  tlia  oolun 
oblalDad  an  aJwayi  dark  aud  ihrty-lnoking- 

Puriflcd  lardaoein  b  readily  loluble  in  moderatelv  dilute  ammonia,  aod  citn,  by 
•THioratina,  be  obtained  from  ililn  Nnhitloti  iti  the  form  of  loiicb.  gotatiiiou'  HaL'rw 
and  tompa;  in  thie  fonn  iljcive*  focblv  rracli una  only  wilh  iodjiio.  K  the  cxccaa 
of  ammonia  ti  nppllcd,  the  «olution  becotnm  ncutml,  and  u  precipitated  by 
dilute  addN. 

PrrfMtraiioH.  Tlie  gland  or  olher  ibaiie  coiilaining  Ihia  body  is  cut  D|i  into 
aniBll  pi«cm,  anil  tw  iituub  oa  poMible  of  ibp  iurroiiiidinK  tissue  rt-mnvcd.  Tho 
pifvm  are  tbrn  cktractMi  ■cverni  time*  wltli  wjiIvt  and  dilute  alcohol,  and  if  not 
ibtM  n-ndricd  col<irl<i«,  are  rcpralt-dly  Imilcil  wltb  alcohol  oootnioiDg  hydrochloric 
ftctd.  Thu  rcaldue  after  thin  operntion  im  dlgoaed  ni  W  C„  with  good  artiflclal 
gaairtc  Juice  in  eiceaa.  Everyihing,  except  tnrdaccin  and  xmAir  qiiantitin  of 
mucin,  nurl«in.  kfi:ain,  lotn'iber  with  uimi-  pcttion  of  the  olastic  tissue,  will  thua 
be  diutolrcd  and  n-movcd.^  from  Ihc  liiilcr  iinpuriliia  it  may  ho  separated  by 
d«cantatiun  of  ibe  liiii'ly  iiuntlvred  Bubataace. 

Tho  chief  products  of  Ihc  decomposition  of  pi^lcld*  are  ammonia,  car^nii: 
anhydride,  IniRtn,  and  lyiusin.  t^ornrnl  other  bodiw,  for  the  most  part,  like 
levcto,  amidalfd  ucida,  nucb  us  aspartic  acid,  glutamic  aaid,  etc..  have  also  been 
obtained;  alto  by  trjptic  diKMlioii,  hypaxaathin,  and  perhaps  xanibin.  Bui 
orcabaa  never  yet  W^n  derived  hy  direct  decoin position  from  proieid  material,  lUe 
tWtenents  to  this  olfert  having  been  luiscd  on  errors.  In  spite  of  numenrai 
rMiarcbea.  we  cannot  at  present  state  detlnitcly  wliat  is  the  real  constitatioD  of 
a  pmlrid,  or  in  what  manner  th«n  several  r«alduniareoonlain<d  in  the  undecotn- 
puMMl  Rututance,  U  is  unnecemary  In  give  here  any  of  the  formnlic,  ncnriy  all 
emplri«al,  which  have  been  made  loreprewot  a  proteld  :  they  all  f^iiv  with  e<|ual 
exnclilude  the  percontofe  compodtioD,  but  beyond  ibis  lliey  are  un  trust  worthy. 
Uf  tlie  various  attempts  which  nave  beon  made  to  nasign  in  nmlcids  some  deRniUi 
molecular  atruclure,  none  appt-'ni,  at  the  present  xtaffe  of  inlortnaliou,  suffideiilly 
reliable  for  general  acceptance. 

Among  ibe  most  clsbomle  Isluni  in  tbii  dirKiloo  may  b«  manUonsd  (bw  oJ  UlMlwals 
and  HaMnoaa.  In  their  Ant  piitilKatian,*  «Urtiug  from  the  pnetal  simikritr  of  lli»  pr«- 
■liMlB  of  daeompuailloD  of  tlio  jirulaids  aud  cartwIiydraMa,  (kay  triail  to  •stablish  ■  iMInlto 
relstioa  bslwcan  Iha  t«o  clsaot  of  bodies.  In  this  tbey  were  not  aorneiafal.  and  ia  tbnr 
Mcond  mmnli*  Ui*y  mine  ki  the  oouelution  Ihal  the  oartwliydrstea  lake  do  part  ia  the 
foriDslloD  uf  the  prolflldL 

OUier  experinienM  In  the  samo  dlreelioo  hare  been  laaJe  by  SthUtseabarxer.*  Re  ahows 
lliat  albDrain  cso  b«  dscoinpoMil  Into  tartunle  aahydriils  and  anunoaia.  sad  that  lbs  rslle 
of  tboe  two  i*  Ike  tmau>  as  tboegk  nrea  hwl  beea  the  bodr  oa  whieb  ha  opceatad.  Kfam 
this  h«  ooiioladss  Ibat  *'  tlis  molenile  of  alfaum'n  onnlsins  tho  |[muj>ii>ji  tf  urea  and  rein*- 
■enls  a  cgauplsx  urclde."  Ia  lik*  aeaiad  publloatlou'  lio  oouAnn*  hli  pnvivna  rtaulls.  «t«<nc 
that  the  aaiaiaiiia>  ofboiiie  sahydride,  and  oxallo  aeidi  nrodwed  by  lbs  dBaampowtioa  of 
pratald*,  ars  *o  oonnoolsil  i|uanliiativsly  ■>  la  Iw  eabsbis  of  darivatioa  from  vaiyias  ptMwr- 
tlo«*  of  ntoa  and  oaamidc    Ha  al»  obtained  from  tba  deoaupeuDon  of  pMtald*  a  aiuo 

K»WB  rsssdiss  whioh  oould  he  ftirmulsled  at  gi'I&K  rise  to  all  ttis  sni>>Uie-l  vidi  ■»■!  otlior 
las  qiokoB  of  atBVOL  Tlius,  suconhnc  to  hiia,  ■Ibuiinu,  built  ugi  as  ■  minplsx  uialdo, 
deoouipws  into  soinioiiiB,imibanie.M(Bliej  sad  aeatle  aelds, aad  Ibl*  altrDgeuoiM  body  {  this 
UMiboii  %\ifnm  in  lb*  oihor  prodaetsof  d««««np«altiea,* 

I  Wtm.  ninl  WorbcnHlif,.  Xo.  U,  R  Til 
a  (Voi^  Hsnd..  T  liii.  <■*»).  a.  law. 

•  XnhD*  and  KadMir.  VIntiow's  Arahli.  Dd.  ixxllL  <IMU  1. «. 

•  Ana.  d.  dKOL  tL  fhinii..  Bd  <IU.  S  SM.  ■  lUO..  M.  dxis.  a  IW. 

•  Geaipla»ltsBilufcT.sO|ISJU.p.Ba.  Bull.4a1s8uo.CMn. axlll.,  1«1, IM:.lU,>KMf,«Kulr. 
Setiu. 

■  UDmMsHsBdos.T.  laxsl.  r  IKK    UulL  da  Isteo.  CMm.  xst.  liT 

•  8se  alift  aelMMabHivf .  Ann.  do  cksOL  01  <Se  rays.,  T.  KM.  (IMI>>  ft.  atb 


1080 


APPIHDI] 


Botubl*  in  HC1  0.1  pta  cent,  in  ihe  cold 


It  wilt  b<-  notlcfld  tbKt  in  the  Kon«r&)  description  or  tli«  rariooa  prolwb  i 
tinclive  rOAcliou  tar  Mch  oould  not  l>c  k<wb.  but  that  varying  •otnmlitW  ' 
tbeohlsf  m««nHat  ourdUpoMl  for  iliniinguiahiiiK  ih«tD.    Tbc^  tna^  t>«  i 
Moofdlag  to  their  Mlublliti«H  In  tlic  fullowlog  ubaW  forui : 

Solublt  in  iluHlled  \etilfT — 

Aqu«')U8  solution  not  coRgolated  on  boiling    .        ,  l\ptonf*. 

Aqucoiu  wolution  con^lntH  on  boiling  ....     AAmtidma. 

iMOtuhle  I'ji  dUtillrd  water ; 

Soluble  in  NaCl  volution  1  per  cent OtohvHa*. 

Insoluble     " 

jAcH-  atid  J/faff- 

Iiwoluble  in  IICI  0.)  per  cont.  in  tlio  cold,  bnt  Mlubia  1    rl_;_ 
«l  60"  a  .        .        .        .        .        .        .        .        ,1  "*"'^ 

laaoluble  lu  UCI  0.1  \wr  cent.  &l  IIO'C;  aoluble  in  rtrong  acldft. 

Soluble  in  gMtric  juice Qtag^ibOtdi 

losolnble        "  " lianiaceiA. 

'fliudl  K  clflMifirAtiOR  i*  however  obviously  a  wholly  artificial  one.  uiiehil 
ilMp4uo'  puriMiKM.  bill  in  no  wny  iiluMntiniK  tbe  natiitnl  rplalioiMof  ibi?  u-i 
memben.  Nor  i*  n  diviaton  into  "  native"  and  "derived  "  pmti-idii  mui'li  n 
unlhtacliiiy.  It  ia  true  that  we  mnr  ihun  put  tofetlter  ■crum-  nniI  ciri;' nlbnu 
with  vitellin.  myn«tn.  nnd  fibrin,  oti  tlie  one  hand;  and  iieptonra,  coagulated  | 
telda,  and  arid- with  :ill!«liKlbuniin,  on  t)ie  oilier.  Bnl  in  what  light  are  we  U 
eoneider  casein,  icciiie  tliat  thoiiich  »  nntural  product,  it  biu  to  many  mffcnblaaMi 
to  alkali-albaminf  Moreovrr  ibi-- >yiitem  of  clKMification  moat  be  luwIeHwliitk 
would  plnoeflbrlnoplutlcgloltiitiii'arid  fibrinogen  in  the  luune  claw ■■  fibrin, lad 
yet  we  can  hardly  gpeak  oteitlii'r  of  the  two  fomier  bodies  a>  derieetl  protelda  If 
the  view  be  true  that  wbrii  fibrin  is  uonverled  into  pejHone  the  large  iiioleralf  of 
tbo former  ii  split  up,  with  nwumplion  nf  water,  itito  two  ■mailer  molrculn  "rihe 
latter,  one  belonging  to  the  "  anti "  nnd  the  other  to  the  ■'  heini "  groaj).  we  ■igto 
speculate  on  n  (loatible  doiwitication  at  all  proli-id*  inlii  hctRt'frniridK, 
proteida.  And  holo-proteldi.  Thus  serum-  luiif  oi;);- album  in,  niyunin.  and 
would  be  undoubledly  hnlo-]>roleidit,  pt'ploriM  either  nnii-  or  hemi-prMieids, . 
we  should  have  to  (fi'tin^iiinh  I'r'iliahfy  jn  the  heteiogeneoas  grmiD  of  <' 
albnioin*  both  anti-,  heni-,  and  htil'iiirMrid  memhen.  it  U  pnatihfr.  mar 
tliat  flhrinoplastic  and  Gbrinogennus  cldliulin  stid  rnnrin  may  )ir  natural  heioi- 


veBiBkt 
d..iSH 
id  M^H 
^ids,^H 


anli-proiei«t.afld  not  bolo-proteidi^ 
on  these  |ioints. 


But  we  have  at  pmvnl  nu  puaiiiw  knuwledgt 


NlTK0<IK.VOD«  N05-CKyitTAI.LIXK  ItODItK  AMJRO  Tft  PROTKIDi. 

Thse  resetnhle  tlie  prolelde  In  many  general  jxtinlH,  but  exhibit  ■motiic  thrm 
selvea  mtich  erealer  dlfTerences  than  do  Uie  |>ri>l(>iihi.  As  reganls  Uielr  molociilsr 
stmclure  nothing  Hatiafaetoryi*  known.  Tlieir  pcrceatage  wMnpoaltfau) apptoMliw 
thst  of  the  ]>roteidii,  and  like  Ihcse  they  yield,  under  ^drolytic  tnalRient.  ~ 
i|uaiilitie)i  of  leucin  and  in  oome  ease*  tyrown.    They  are  all  anior]ihoiu. 

Muoln.    {O,  S&,T.V    n,  d-Mi.    X,  HSO,    C,  *8.'>».)' 

The  chnmcterifitic  component  of  niuent.  It«  exact  «im]KialUoa  ia  ant  j*i 
known,  the  fixurea  Kivon  above  beinj{  merely  an  approiimstinn, 

Ai  occurring  in  toe  normal  condition  it  given  lo  the  fluidn  which  contAin  It  ibr 
well-known  ropy  eooalsleocy,  and  can  be  precipitated  (r«m  thsM  by  acetic  acid, 
alcohol,  alum,  and  mineral  acids:  the  latter,  if  ia  esccHS,  redtuiolte  the  on- 
cipitate,  but  this  u  not  the  eiwe  with  acetic  acid.  In  Its  pt««I|iiiaied  foro  itb 
inaoluble  in  water,  but  iwells  up  strongly  in  it,  and  thin  dlTeet  u  tncrea;i«d  by  tht 

freaeuce  of  many  alkali  anlts.  Alkalies  and  alkaline  earths  dkaolve  it  midlly. 
Is  solutions  do  aot  dlalyse:  they  give  Ibe  proteld  reaetiomi  with  Milloo* 
resgent  and  nitric  acid,  but  not  that  wltli  salplutte  of  copper,  and  are  precipitaltd 
by  basic  lead  acetate  only  when  neutral  or  faintly  alkaline.  According  to  Hichwald,' 


I  Bcbwslil.  Aiia.ll.  nhBti-B.  riuirni.,  Kd.exxalv.&lMk 


•  Op.  at 


wb«o  beaUxI  vith  dilut*  miticnl  adds,  niiiciD  yields  iicid-i,IUiniiB,  bdiI  iuinck«r 
body  which  in  nuuiy  of  ilx  |>rQ[icrlit«  cloaelr  memblr*  a  nugnt.  inuniiich  im  it 
rrducM  itolulionii  of  cupric  sulphate.  Prolougtd  bviliug  witli  Buiphuric  acid 
pvM  icndn  and  abuut  7  per  cetil.  of  lyroalo. 

Ptrf/tirafion.'  Oi-tjall  or  aii  nqUGoiM  cxlract  of  finclr-choppcd  mibmaxillanr 
fland  lBaciilulHi(«l  wiih  at-pticacid;  the  pmHntCatcd  mucin  to  tbrn  wimIicI  with 
waUf,  diuolvril  in  dilu[<i  Rodic  carbonate  and  nnallj  pracipiuicd  iritb  ac«tic  acid. 
It  tnaf  iilao  bu  ubiniiit-il  fnim  iiuaila.* 

Ohondriu.     (0..tl.i)4,     H.fl.TI,      N,  IS  h7.     C,4T.T4.     S,  OHO  por  cent. )» 

Thia  la  uatially  regarded  aa  forming  th«  iMiGnlinl  part  of  the  matrix  of  hjaline 
GUtllage.  and  la  contained  in  the  inlonticei  of  Ibe  fibfi*  in  dnilic  mriilagc.  A 
■imitw  aubatancc  can  be  prepared  from  tbe  cornea.  Eloiltil  wilb  n-iii^r,  it  dia- 
aoIrA  alowljr,  fonuinjc  an  oiwle>c«iit  solutiun,  wbloh  ia  precf)iiui<.il  by  Htrtic  acid, 
l«ad  acetate,  dilute  mlaerul  acid*,  alum,  and  «alta  ofHllTer  and  mpper:  aii  exce« 
of  the  taat  four  reagent*  r«disMi1vM  the  preciptale.  SoliiiionH  of  thia  body 
g«lflllRir«  on  Maiiding,  wen  if  vrry  dilute:  the  inlid  miiaa  ia  iaonluble  in  cold 
water,  teiulily  tnlublr  in  hot  water,  alkalies,  and  ammoma. 

Tbe  aqneooii  and  iillculine  nolulionii  of  choadrin  powota  a  left-banded  rotaijr 
poiraron  polariwd  tight  of^itlS.ft";  In  presence  of  «xce«a  of  alkali  Ibtobeconea 
-603.0°,  both  measured  for  yellow  li^hi.' 

Itaeems.  accnrdinKlo  ihc;  nbtctvation*  of  many,  thalcbondria  can,  bv  heating 
vith  hydrochloric  acid,  be  i-onverlcd  intu  a  body  wIi'mc  reaction*  reacmble  tboM 
of  aynUHiin,  and  anuthemubauinoe.  which  like' tin- simitiir  product  from  mucin, 
*o  till  reaeuiblea  grape  ^ugikr  IhnI  Jl  reduces  cupric  twltii  in  alkaline  »oltitlon  :*  it 
npiicart,  however,  to  i-onliiin  iiilrocen.  The  cxiolence  of  cbomtrin  b"  a  dMtincl 
(uMancc  bus  bowever  been  denied*  itii  thcnupiioaition  tlial  it  la  in  all  i-iuici  a  mrrf 
mixture  of  other  boilien.  It  is  itnted  tliat  a  auHlanoe  having  all  the  reniti'irin  of 
the  ao-cultrd  chundrin,  may  iit  any  lime  be  produced  by  a  mixture  of  mucin, 
glutio,  and  inorgaotc  aatts.  The  extreme  ulmilarity  in  tlie  reaL-tionit  of  chi>ndrin 
and  mncin  point  to  a  cloac  rolationnhip  l>ctwc>en  the  cini.  The  whole  subject, 
bnwcTor.  reijiiiriv  ni<irf  einuolctc  invt«tij(atinn.  With  alkulir*  »r  dilute  Hilphuric 
acid  chondnn  gives  leucin,  but  no  tyroitin  or  glycin.  Whether  chondrin  exi*ts  M 
uicb  in  ciirtilnse  i*  uncertain  :  it  iiecms  probable  that  it  does  not.  liuce  ita  exirao* 
tioD  from  eartlldfe  rer(i)ireH  an  amount  of  boiling  with  irater  much  greater  than 
that  reijiiiHiie  todissolva  dried  chondrin. 

Prr/ioT'itinH.  From  cartjla(«  by  extracting  with  water,  and  precipitating  witb 
acetic  acid. 

OAlAtln  or  Olutin '  (O,  2«.SI.  B,  7.16.  «.  l&aS:  C,  M.».  8,  0.60  per 
onai.) 

Thia  la  the  aubatance  which  U  yielded  nheii  coo nectlve-l lane  flbr»  arc  heated 
for  several  dHy»  wiib  very  dJIuie  acetic  aeid,  at  a  temperature  of  abinit  16°  C,  or 
by  tlie  pnilonge-t  iii'tion  of  water  in  a  Papin'*  digoler.     The  clantic  olenienla  of 

t  connective  tiiuui'  arc  unatTected  by  the  alicivc  treatment, 
Aanbtaine<l  in  this  war  glutin  w  when  tirait'ln  thin  riuid,an|{difylDg  on  cooling 
t<i  the  well-kodwn  gelatinous  form.  M'htii  dried  It  it  a  tnlorleM,  ttvntparcnt, 
briliie  Ixidy.  swelling  up,  but  rrtnniniiig  undiwnlved  In  cold  water:  heat  tog,  or 
the  addition  of  iraco*  of  acidn  or  nlknlim,  rcndit.v  elTccta  its  aolnlion.  Whoa  dla- 
nlred  in  wnU-r  it  ponieaaea  a  lirvo  rotary  power  of  -  ISO*,  at  W  C. ;  the  additioa 
of  Mrong  alkali  or  acetic  acid  re<luc(«  tlila  to -113°or-ll4*,  both  mcMUrcd  for 
yellow  llcht.'     Its  soluiion*  will  notdtalyse. 

Mercuric  chloride  nnd  tannic  add  are  the  only  two  rcagenta  whtcb  yield 
inaoUibli'  precipiiutr*  with  thii  body,  tis  presence  prpvenla  tfa<'  action  of  Trom- 
■ner**  (Ugar-test,  since  it  readily  diMolves  np  thi;  precipitated  cuproiii  oxido-  Th« 
proteid  reacUooH  of  gtuilo  are  ao  feeble  that  they  are  probably  due  merely  to  im- 


I 


<  nchtiklil.  op.  (Mv  aad  Chcm.  f-pntnlli.  IM*.  Xo.  II.   RaaMar  Ano.  d*  rb«M.  n.  num.,  Bd. 
eai.att    iADdw«iiT,z*HK<b.r.|ihx>b>Ln>tK,  B<i.T.na«iks.>n. 

>  LiUHtmbr.  ]!t««ih.  t  phplnl  llxin  .  &1.  ti.il'Kx.fL-n, 

•  naweiiSkt.  B4b.  pttya.  pMk.  Olwai.  AitiL  (  .Inl..  Wn,  8.  m 

•  )IonM<6a«ei?\'i^Mn'i,  ?Mulbli.-tDm).  V«t.  Il«i4tlb«rt.  U.  I.  (UHh  DtL  S. 
T  yMlntKoonfainuIal  vtUi  ttrnKaKtMatmUliffliiMa." 

•  Uopiw^eylu,  U'lk  •!.  t>Or*.  f*iIi.  obMa.  XaaL, «  Ann.,  wit,  B.  2a. 


1082 


pvritlM.  Heated  wilb  Bulpburk  ackl  It  yields  amiitoHU,  l«acla.  tni  glrcla,  bai 
BO  tjrnMla. 

Il  nppMU»  impniluililc  Itinl  itli'tinexUtii  t«iu)yfoniital  in  mnnn-i'  -  i'  flhra^ 
•intw  ibiae  tin  not  Bwell  up  in  wnivr.  nii<l  nulv  vii.'1il  glutin  alirr  '  Inat- 

■i«Dt  will)  builli>|;  iinur;  to  which  it  niAir  be'*dd«d  luai  wliil«|:liiiiri  ]-i  Aiinl  mpon 
hj  trypBiri,  tl)c  t-niine>.-[iv^tiMU4>  Hbm  in  Ui«ir  Oklurdl  i-ondiiion  rraUt  its  Ktioa 
(i«pp.  %'>i}.  Wlion  vlutin  ia  Knhmitlrd  for  rowe  lime  ut  ttic  ncliuii  of  dllM* 
hydnidiloric  acid,  at  38°  C,  nixl  llio  dungc  ■■  brouKht  about  eren  mon  rawUh 
hv  the  Hc^loo  of  p«p*iu,  il  lobta  iu  poner  of  cekiiniting  and  ia  now  dlAMlib 
tlin^iigli  noroiM  metnbrancfl  ;  tbe  name  of  getalin-iieploDe  baa  been  given  toUw 
produoi  tniu  obtiiined.' 

Elaatln     {0,SO.&.     H,T.<.     N.lfl.T.    C,  6G  S  pnrceoL) 

Tbls  ehBracUriBtic  i-oiupniieDt  of  elaatic  Dbrc*  U  leA  on  lb«  removal  ut  alt  ib> 
gititiii.  niudii,  oic,  fnini  Mich  tlHii«a  as  "  llgameniam  noclue."  odraninf  ic  Wiuf 
tnken  of  ti»  not  biinji  nlirrccl  when  il  is  hcniod  with  uater,  rvtn  uoHvr  i>teHura, 
Itilh  Nlr(iti)(  BCL-lk  lu'iil.  or  wilh  dilutr  nilcniir'K.  When  moiM  il  U  ji'llnw  and 
clnHiic.  but  uD  Jrt'iDf;  tiecoincB  britilv.  It  in  lolublc  in  *ui>ii]c  alkitlieB  at  boitlif 
tMtiperalureit.  and  conceiilratcd  bulphuric  niid  nitric  addadiwolve  ii  eten  lalW 
cold;  it  i«  al«o  diwolved  bv  the  action  vf  pfliiaTa  juit-iv  It  Ii  preciirttatc)  fros 
tinlutioTii'  by  laniilr  Acid,  but  not  by  ihr  luldi'tion  nf  ordinary  aci<l*.  Ndwhfc- 
aUndinic  Ihnl  it  clwclyappruiichoilhi'  praloidtiinita  pcKcnla)(v  compoiitJan.  tat 
giTCa  liittl^ucl  altbou'gb  feeble  pruteid  reactions,  any  very  cliwf  rc1atloB»Up 
between  the  two  appear*  imptubable.  atnce  elaalin  wben  treated  with  sulphiuw 
acid,  yicldn  leucin  |S0-40  per  ceiil.)  only  and  no  tyroaiii.  ~ 

i  lilKcr'  hail  obuincd  a  mmilnr  btxiy  from  the  abvtl  t&embtane  of  anaka 

Keratlc*    (O.  SaT-Ss  0.    H,  0.4-T.a    >',  IS  3-17.7.    C,  W  a-£3-S     It,  AT-U 

ptr  cunt.) 

This  body,  [hotigh  somewhat  resemblinc  ibe  prolcidi  in  general  oorapcNlliM, 
dill'en)  fniiii  Uiem  anil  aUo  rioin  thi-prei^ethiig  boaieaiowidvly  iu  other  pmprtliM, 
Ibnl  il»  dc»crii>l)i>n  i*  ptiiccd  here  for  roiivenlence  rather  than  anything  'W. 
Hair,  nniU,  fratheni.hitrn.itnd  epiilcruiicocalnconaiitfor  themo*t  part  of  keralin. 
Ileatcl  wilh  wiilrr  iu  u  diErmtrr  iit  IW*  C.  koratia  i»  partially  diaaolred  with  ew 
lulion  uf  HuIpburrttciJ  hydr<i|;en:  ihe  wibition  then  jciTe*  with  aoatic  acid  and 
fermcyanide  of  potauium  il  precipitate  soluble  In  excew  uf  the  acid.  Pnlonnd 
tralliiig  with  alkalies  and  scidt,  even  acetic,  dtaaolvea  keratin;  Ibe  alkaline  mm- 
tions  cTolvc  Hiilphurvtted  hydrogen  on  treAlment  wilh  aclda.  The  eul|>hur  ia 
kemtiu  il  rviduntlv  rcry  Icinat'ly  united  In  the  nibiitance,  and  in  all  it*  rcaelioaa 
there  iippean  to  be  a  wunt  uf  xiniiliiritT  between  keratin  ami  eitJier  pioleldi; 
mucin  or  gelaiin.     The  bio«i  ci'niiuon  uf  itn  pniducis  uf  deoompoKitioii  are  leode 

ilVjierccnt)  and  lyrnMn  (8.0  per  c«nt.].  and  aonie  aajiartic  acid^  no  cljcta  it 
irmed.     What  in  jcenenilly  known  iw  keratin  io  probably  nconipound  bQ^,«Uek 
ha*  iKit  yet  been  molved  into  it*  cumponenta. 

Kwitlil  unJ  Kuhiir'  buvo  deKnt>«l  ■  now  (nily  to  which,  —aam  It  e««iir*aaa  e«i<UlBMI 
of  uetrav  iisiiie  tboih  of  nerve*  ami  "f  lli«  eeniml  nertuiu  in<icin|.  aiiil  ia  yat  rinwity  tSt^ 
liotl  wit^  ordiiiarv  horny  liMna.  iliay  (tire  ItM  tiiiinn  ••!  ii<tin>konitib.  It  U  mparol  ia 
quaiiUly  (hiiD  tbebrsin  byeilraoliTiK  Ihli  tjBUe  witli  iI.viIkiI  ■»)  Hlmr,  aii-l  hiI^hiIIki; IU 
residue  to  the  sdifln  otftptia  nnJ  Itypin.  The  liiial  nwi.luu  ii  ueiMO-kciMiB.  aira  •mnrtt 
Id  I&  Iu  te  |<er  o«L  of  lb*  orisinal  tl«u*. 

Nuoleln.    C„R«S,P,0^ 

Diftcovered  by  Mincbei*  in  the  nuclei  of  nna  cmrpiHclM  and  in  (lie  yellow  mr- 
jiuicle*  of  yolk  «f  rnK'  fXhct  obecrvcni  Iiaw  NUhMqntfitly  obtained  It  from 
ypMt.  from  Kcnicii,  I'lum  tlie  nuclei  uf  the  red  bluud-AOfpiticIni  of  litnia  and 
amphibia,  from  liepmio  cells,  and  il  b  tirobably  pKaciil  In  all  nuclei. 

Wbt'U  newly  prepaied  it  la  a  oolorleM  amorpboua  Ixidy,  eoluble  li>  n  alifbl 
extent  in  water,  rvadilv  aolnble  in  many  alkaline  MitutKuia;  but  lie  aolubilttie* 
•Iter  on  keeping.    If  added  Kradually  in  tiiibcieai  •(unntily  to  aaoluUonof  camtle 


■  pciftMlM«(,MtMli.  f.  pbr-tol  (TiMin..Bd.a.<in*I.B.niL 

•  SnTft.  muliwtL  Cb«l>  '--  l.-^     t,?\  -^  w..     ii,,r__-r, 

•  lMnII."Kan»IA]r 

•  X'trtiaod.  XaHiUM^  < 

»  Mtd'ltan.  UmwwiJi..  1.  , ..  .,..-,  111.;,  t,  .    ...    .;; 


■'  •vA.-nnoc 

Il  ITLtt«l).^aldL 


CURMICAI.    BASIA   OF   T  H  IC    ANIUAL    BODY.  1033 

ilkali  It  Drill  neulnilixe*  tli«  HQlution  and  tlien  rend«n  ll*cld.  Ilseenw  Co  piaur^* 
all  iDiliKlinrt  »nt)i(i-|in)t«<ic  tcaclinn,  but  glvM  no  rMi-tJon  with  Millon't  llitid. 
It  fields  prcvi  pita  ten  with  sctctbI  mIi*,  r.  •/.,  linc  chloridtt,  nrKcntfc  nUrate,  and 
cunric  oilphaie. 

/yrjiaraliort.'  Since  nucttlii  is  vttf  r«ii*t«Dt  to  the  kCtioii  of  pepsin,  Jt  mny  Im 
obtained  fiofli  ih«i  granular  n-oidui;  coiwlalliw  oblelly  of  uudci,  which  m.-i.-un  ufter 
dlKn>lii>K  p«i»  wiLh  jicpsin.    The  iiicMt  rvinarKabI*  featarc  of  thin  body  U  ita  large 

Cerceniaee  uf  jilioiiphorus,  9.6fl  per  cent.    This  pbonphoriM  U  nwdUjr  separatod 
r  boiling  witli  Btroii)-  bydnivblaric  acid  or  caiiatioatkaliea;  the aame occiira  wllVB 
Mlatioa*  of  nucl«ih  are  aciduUt«<l  und  allowed  to  itaiid. 

OWlln-    t;^n,N,0„'. 

Altbuuch  nut  found  lu  a  con*tilu<'Dt  of  any  maTniiiulian  tiMue,  thii  aubiiUnu 
CMBpcwfl  the  chief  part  of  ibe  exo-akelelnn  of  dudt  iorcn«bratea.  It  mty 
pnibabljr  be  reearded  aa  tli«  animal  analngue  of  the  cellaloM  of  planta,  and  ttom 
tbh  pniDtoriicw  it  poMeMca conatderable  morpbologk-al  Inlcimt.  DoUi  oolluloae 
an<t  cbilin  njiprai  to  Tivld  tomo  form  of  augnr  nbeii  ircjiti-d  <ritb  *trong  acida. 

Whrn  purified,  (.'biiin  U  a  white  amorphuua  bcxly ,  nlli'n  rctHiiiiug  the  tfbape  of 
tb«  llttue  from  which  it  baa  been  prepared.  It  i«  in«oluble  in  all  r<«K«nla  eacapt 
atimtg  mineral  acid«.  the  beat  solvcnia  beloK  mlphurlc  or  hydroculoric  acim. 
Tbe  iinmvtliatr  addition  of  water  to  the««  ooluUon*  r«precipltate«  the  vbiliii  in  an 
unaltered  form  ;  but  the  prolonged  action  of  itul|iburtc  acid  cau*r*  a  decomtioal- 
tlon  rAnlltDg,  uccording  to  mme  iilscrTcrc,  in  the  formation  »r  an  amoruliotu 
fermenlablc  earbubydrate ;  nutl  when  bydroi^bloric  acid  in  used  an  amldatcd  car- 
bofardnte  ia  obtained  to  which  the  name  of  glyt-ottamin*  baa  be«n  given. 

/VaM?rj(i«n.*  The  cleaned  exonkcletoii  of  a  lobnter  i«  thorou)tb1y  cxtmcied 
with  dilute  liydruchlorie  avid  and  thru  with  cauntir  aoda.  To  purify  it  l^natly  it 
ia  Hibinitted  to  prolonged  boilin);  witti  a  Hotution  of  potawic  permuugamite. 

CARBOHYDRATES. 


Oartain  m^mbcra  oaljr  of  thia  ctaaa  occur  in  lb«  human  bodj ;  of  them  lb«  neat 
imputlaot  and  widopread  uo  thn*c  known  hh  glycogen  and  tM  twoauganitgTkpe' 
■agar  <>r  di-xlruii-  Igluctmc),  with  wliich  diabdic  ■uciir  iieMna  to  be  idOBticar  SDil 
nsltuae.  Next  tu  ibeite  L-ouiea  milk-sutcBr.  luiwit  la  another  body  of  this  cltM, 
•lIlHMigfa  it  dlfTera  lu  many  inipciriaut  |>oiuta  fruiu  the  preceding  two. 

8nfu*  tn  oRon  miuiilikrvd  to  be  puljtlioiiic  aloohala.  SannJ  of  tbeiu  itand  In  peculiar 
relation  I"  inannit,  and  may  be  «>nveri«<l  inln  that  ■abttanc*  by  Itie  u'lion  uf  toiinia 
aBalcaRt.* 

1.  DaxtroBO^Oni-o-tugitr].    C.n„O(+H,0. 

Oocura  in  the  cont«Bta  of  the  sUmentarr  canal  to  n  variable  extent  denendcnt 
on  the  nature  of  tha  food  taken.  U  in  alio  a  normal  conittiturnt  of  blood,  clirle. 
and  lymph.  Ounceming  it*  prcaenoo  in  the  liver,  aee  p.  'iT-l.  The  amniotic  fluid 
alao  cunlalna  thia  body.  Bile  in  the  morputi  condition  >t  free  froBi  ougar,  ao  alwi  u 
urine,  llmugh  thi«  point  haa  giren  riae  to  great  dittpute.'  Tlie  dUeue  diabetea  ia 
cb*raet«riMd  by  an  picau  ot  dextroM  in  tba  fluida  and  tiwucti  of  the  IkhJt  (w* 

When  pore,  dextioae  ia  colorlena  aod  eryatalliua  from  iu  ai]ueaua  aolnUon  In 
•lg-ald«d tablea or  prtoma, often agrio™'^'*''*'  iniowartylamp*.  The crystaU  will 
diMolve  in  their  o»d  irdglit  of  oolil  water,  requiring,  however,  aume  time  for  ib* 
proeem:  they  are  vetf  readily  aoluUe  in  hot  water.  Dextraae  ia  wKnewbat  ipar- 
tngly  aoluble  in  nlcihul,  and  cryatalliuK  from  anbTdraiu  alcohol  tn  priauii  free 
from  waUr  of  vryatallixolioo ;  it  i*  marearer  iiwolubia  iu  cihcf. 

■  ate  komh,  znuoh.  t  nhnini-  ctimi ,  Dd.  ni.  ntiff,  SL  m :  to.  nawh  B.  M) j  vlLllaa).  B.T. 

"yUMWoli.  aterd  Nurldii  u  liini  ■'[■HufiMirml."  Blrw»a  ■  Un. 

*htiATtum.7i»-rh.  I  |<i>r>ini  'luon.  ifl  tl.  ii*7«).a.  ai 

•  LiMCTlm*.  I'ffi  cit..  M.  IV.  imjl,  !^  XK. 

•  Ba(wii)i.  Areii.  t  A»i.  u.  it>n>»i-  Jaiux.  in«,  &  an. 
*l^qiw«ii9n,liiiw»T»f.wliiniiw>»t«i»i««rt»ucaofia«areeewnlaalaiheaywallioJyh>wnM 

bam  conhundM  io(«llwir  uudv  ibe  eamnnn  nama  td  AunvM  tm  ilaeoaa  n*?  bt  onwilital  at 
MMM  an  opts  «n& 

•  UnuMMiia,  Ann.  d.  Cbvm.  n.  PhMU.,  M.  mill.  B.  laa 
1  Sm»mt».  tMrMa»«MHMU«ut.laL.lL  tM 


J 


AVVKnOlT. 


Tlie  ftMhljr  prapnnd  «ild  «qaaMl*  ■olution  or  tliD  cry*!*!*  tMMMaM  «  daKUo^rutalor;  pM* 
»r-rt04°rurf#tlnir  lialil-  Thi*.  qakblr  oil  lia*ilB(,nHt*H«wI]r  on  Maailiug.  rklti  ("  -it', 
Ki  which  paiul  il  nioMliii  oonaUat. 


ItaxtnMB  resdilf  fntin*  Mni;»und"  witli  *oiiU  lad  nanj  MtU;  the  laUrr  u>»  vary  ■Ilu•ila^ 
doeonipailfii.iD  nkpidty  i>nliiiii|[  va  IiMling  llivos.  Wh«a  lU  laatolllc  oaminaiid*  »ra  iimm- 
pMtd,  Iho  docompoaltlwi  I*.  In  auutj  cmo,  •iin>in|«niad  br  Uia  pranpiintin*  ol  l]i«  mMUh 
«■  If:  taivm,  itiild.  meraurjr,  blefnuUi.    Ckuilin  iitkiiliN  rMilj'  lifMupsM  ihMD,  ■«  aim  Aim 

Dextrose  in  nwillljr  nod  coranlfftety  iirvcipilAUxl  by  lead  koeUU  and  aniiiKmii. 

Ad  (mpiirtnal  [»rniiert;r  of  "i'n  body  in  iu  |>ower  of  undergoing  Iwwmitow. 
Of  tbeae  the  two  princlpiLl  ar«:  I.  AktrMie.  This  u  ptx>dtiM<(l  ia  «qu«atu  aoln- 
Itonn  of  doxtrose,  undvr  ilie  inllueDce  of  y««Mt.  Tbo  dfConpOMlioa  b  ibe  folio*' 
inc.-  (',n„l),  =  SaH,a  ^  2C0,.  yicidinB  (*lhrl)  nlcoboi  »ml  c»rbonic  «ahTdti*. 
Olber  ali-nliDU  of  the  acetic  Mcrie*  uc  feond  in  tisce*,  w  bIm  ar«  glyoefln,  ■uc 
L-inlc  add.  and  pniliably  mnnv  other  bodiw.  Tbe  fennenUlion  is  most  adi**  H 
about  23°  C.  Below  S*'  C.  or'nbore  -tA"  C.  It  almost  cntlrclr  ce«<«>.  If  the  mc- 
cbarin*  iolutioa  cooiainH  inoru  than  lli  por  cenC  of  sugar  it  will  not  all  h«  ik«at>- 
piHwd,  a«  exccM  of  alcohol  stops  the  reaction.  2,  iMflic.  This  ucoura  la  U* 
pfta«i)«e  of  decompwRg  nitrogonoui  mH(l«-r,  twpccially  of  caarin.  and  is  probahlf 
th«  rMult  of  the  action  of  a  spvcifio  (erment '  The  firvt  stage  Is  tb«  pitidunka 
of  lactic  ucid,  C',H„0,  =  2CHtOr  Iu  tbe  aeond  butjric  nvld  is  fon)i«>d  wKk 
cirolutionof  liydri>geuaodf»fboolcanh);drlde:2C,H,0,  =  C,H,a,  ■■  2<X',  -  illr 
Tlio  nbova  ch'aiiK««.  lh«  Hrst  of  nhich  is  probabiy  iindi^r^oovi  by  nuxar  to  a  am- 
siderablo  oxtcnl  in  thi^  intestine,  nre  moat  aeti*e  at  Xi'  C. ;  the  preaeiice  of  alka- 
line ciirl)iiimt«ii  il  itt>c>  favorably.  It  is,  moreover,  aisential  that  the  lactic  icil 
should  bi'  neuLrulizeil  na  fiLal  tia  it  in  forui«J.  otherwbe  tbe  pres«aoe  of  ibi*  fn* 
add  alopt  the  proceiu. 

Tbo  preparation  detection,  and  catimatioo  nf  dextroaa  ant  so  fnlly  gifen  in 
rarioun  Imoka  that  Ibcy  need  not  be  detailed  h«re. 

3.  Maltose.    C„U„0„  •  H,0. 

Tbi«  form  ofiugarwss  Hrsl  described  by  Dubmofaut' m  a  product  of  tbe  acHea 
of  matt  extract  on  starch.  It*  cxist«iico  was  for  a  \on%  time  doubted  aatil 
O^nlUran*  repeat^  and  (^«tilirmtnl  the  previous  DsperiinuntA.  Aocordiiw  lo  bia 
It  etratalllcea  in  fine  atrit^ulnr  crystals,  posaeMeu  a  spedfio  rotatory  pow«r  of -r  IU* 
and  a  reducing  power  nrhii-h  looulv  one-tliird  as  great  as  that  of  dextiiMr.  ll 
•eens  probable  t^at  thin  in  Ihe  chWf  «iigar  obtainod  by  Uie  action  nut  only  if 
diaataae  butorptrniin  and  nitnrToatic  rerinenl  upnn  ■inrch  and  {irrhnps  alao  a|M« 
glyotwen  ;>  althougli  suini-  ilcxiruae  may  st  the  Mime  time  be  formed.  MuMului 
and  Oniber.'  have  ahoarn  that  mullose  may  alio  be  formed  b^  tbe  action  ni  dOatt 
nilphuric  acid  on  atarcli.  and  that  it  is  rspable  of  undergoing  alcobolio  ttrmn 
tation.  ~ 

/Wpiitnliini,    Sec  Miimuliu  and  Oruber  {loe.  eH~], 

S.  Mtllc-susar.    C„H„0„  f  11,0. 

AIm>  known  as  taebme.  It  bi  found  in  milk,  and  b  characterislk  of  tbl>  ««er^ 
tioo.     It  is  said,  however,  lo  oc>cur  abnomially  in  tbe  urine  of  lylnc'tn  w<M»m.* 

It  yields,  whoo  pure,  bard.  colorleM  crystals,  belooeiug  to  tbe  rhombic  ayilsa 
(fournidttd  prisms).  It  i*  loan  soluble  in  watv'r  than  dextrose,  roiuiriii)^  fur  «1a- 
tlou  six  times  its  weight  of  cold,  but  only  tvn  |>arts  of  bnilinj;.  water ;  it  is  tatMj 
insoluble  in  alcohol  mid  ether.  It  is  folly  precipitated  from  ila  aolntiona  by  IM 
addition  of  lead  aeetalo  and  aoimouia. 

Wh«n  frMhtr  <li*»lvc<l.  itsiu|u«ou>  ntulion  pMsasses  ■  (piMift«  ittxtm- rotatory  |Hvar  rf 

i-VAJ'tDr  sr>dluin  iichl;  ihit  <liiniii>i>li<M,  •lowlj  nn  Stan  dill  (.  rs|ii<lly  on  iBltinr,  anUI  a 
nslly  iBiiiiuDs  cooMkQt  at  -^UA'.    Tha  sniiHinl  of  rolaliou  Is  Inikjisa'lDat  of  tft  Bsaa» 
Inlion  or  Uh  •utulmn. 

LaciDMi  aaltss  i«aili1y  with  basts,  fnrxninx  unslalila  ■viiiKintitl*:  tittm  Its  meUUIe  vm 
pouiiilt  Ikc  neUl  is  pivcipltaled  la  Uia  rvluvod  slAt*  i-ii  la^lin)-:  II  toliioea  wppw  •slwst 
raadlly  u  d«itn*a  tnl  (o  a  less  exWal,  ris.,  in  the  ratio  of  :<■  t  loll, 

■  Llsur.  rMk  Hm.  Trans.,  vol.  ft*  lf%  v.  ts.  abo  QiMn.  Jaatn.  of  Uteraa  SiL,  ML  s*ui  lUOh. 
p.  in. 
'  Ana.  t^lDLPhnCDixl.  llUTi.nlTH.  •  Jooro.  Cliiiai.Soa..SM.%  *•!.  X.(aB&  h  OK 

•  Mutculusa.  v.Weitiia.  2#ltKh  f  plu«lol,ClimD..  M.fl.  fls3«>.il«al 

'  Zf  iwttr.  b  phnhd.  cImd.,  m.  II.  mn).  ti.  m.  •  UoiMMer,  twd..  Bd.  L  (wrri.  «>,  m. 


J 


CaBHlCAI,    BASIS  OP   THE   ANIMAL  BODY. 


toss 


ctuM  ii  Kenutlljr  tUted  to  udinit  of  no  Jirrct  klcoholic  fcrnvnUtinD ;  this 
miy.  hwTATer,  MHDetlinffl  ba  Iui)ui;«<]  bv  ibe  pruliitipMJ  ociion  of  fetuc  Bjr  bolt- 
tti^  witli  cliliile  Riinornl  acids  \nctnne  In  convorlod  into  giilacUHtv.  wbicli  readily 
nndrrKu  ■lo»h4ilic  ftTmntilalioa  Aiid  poMtcm  n  grcAtcr  rolACriry  power  tbun  IncKMif. 

It  fiia;  b*  ramarkod  h«r«  lliki  Ihoiijih  ifoUttd  Uotu*  la  inospaM*  of  ilinot  kloaholle  br- 

iMitollon.  Billk  ilHlf  m*f  be  Ibrmanteii;  BoftbdoC  ru  naabU  la  thi*  ilipwt  »lcnhr*lic 

ArnMuUtlaD  lo  ilFtM't  uiy  inl«na«dial«  >h»ng*  of  Um  laoteM  into  %WT  Mlier  bnnonuUo 


LaebMe  i*.  hoire*er,  ttimtty  cnpab1i>  of  iinderKning  the  luetic  mid  butyric  fer- 
mnitBlloiw;  tli«  circamsc&ncM&nd  iiroducia  itn?  tbe  name  m  in  ihei.-nneof  il«xlraM 
{•w  above).  The  nction  b  gcnernliy  prcxlacllve  of  n  coUaE^rul  small  iiiuntiiy  of 
aloobol. 

Lactnoe  m  lbu»  ili>tinj^i«hed  tmai  dvxtroM  by  itn  mnaller  toliibility  in  irater. 
Inaolubllity  in  aloliul.  urytuliin*  form,  loii«r  cupric  oxide  reducing  power,  and 
its  incapability  of  uailenrning  direct  alcoholk-  fermentation. 

fiftparali/tn.  After  the  removal  of  the  casein  and  other  prfteidn  of  tbe  milk. 
th*  oiolber  licfnor  i*  <ivaporal«d  U>  tbn  cryntallixing  point ;  the  cryalaU  ar«  putiBrd 
hj  rvpoatcd  crjrttallitation  from  warm  irat«r. 

»4.  iDOalt    C,H„0,  +  2Ht*^- 
Tfals  lubciauce  oocnn  but  ajiariiigly  iu  tlie  human  body ;  it  woa  found  ori^nally 
bgr  Soberer'  in  the  miiacle*  of  the  heart.    Cloetia  abowed  its  prewnce  in  ihe 
kiBp.  kidneyv,  iiplccii,  and  liver,'  ami  Milller  in  the  brain.*    It  occttt*.  aim,  in 
diaMtic  urine  and  in  that  of  '*  BriKhl'*  dlaviuie,"  and  ia  found  in  abuudauce  In 
the  vegetable  Icingdom. 
Pure  iuoslt  fornia  large  efflnreeceot  cryBlalii  (rhombic  lablen);  in  ulcroacoiiic 
I       pf«|iaratioDalt  ianeualtj'otilained  In  inftcd  liini]ittorfliie  cr7>bil».     Easily  Holubla 
In  water,  it  la  inmluble  in  alcohol  and  rthor.     It  nowcMo*  n"  action  on  |iolariii«l 
Illtbt.  and  doc*  not  reduce  aolutiona  of  metallic  aalta. 

It  adniita  of  no  direct  hIchIiuIIc,  but  ia  capable  of  undergoin);  the  lactic,  fer- 
mentation ;  according  to  Hllger,'  the  acid  furuied  ia  aarcolactic.  It  ia  unaltered 
bj  beating  with  dilute  nilTieral  acida. 

IlrtparatioH.  It  niny  be  precipitated  from  il4  aolutioim  br  the  iictlrin  of  6a»ie 
IavI  aMialc  and  BoiiDonin:  tbe  lead  it  then  removed  by  anlphurcttcd  hydrofreu, 
and  tbe  inoait  precipitated  with  exc«M  of  alcobol. 

Ai  a  apecial  teat  I.Schprer'*)  ninv  be  montioned  the  production  of  u  bright  violet 
cnlor  by  care  (III  evaporation  to  dryneaa  on  platinum  bil,  with  a  liltle  ammonia 
and  calcjum  chloride. 

h.  Dextrin.    (',H,gOj 

Uy  boiling  atntcb-past«  with  dilute  acid*,  or  by  the  action  of  feraionta,  the 
•tareh  >■  converted  inia  an  iaomeric  body,  to  whicb.  from  it*  action  on  polarixcd 
light,  the  name  dextrine  baa  been  gireii.  It  insoluble  iu  water,  but  in  precipi- 
taud  by  Htciibol.  Itdoea  not  nnderco  alcoholic  fecmeiitation  until  after  it  liaa 
b«tD  chaiigeit  into  drxtroM,  nor  can  it  reduce  metallic  aalta.  It  yielda  a  rcddnh 
port-wioc  cnlur  u'itb  iodine,  which  diuipnear*  on  warming  and  doc*  not  return  nn 
ooolinp.  rurlhfi  aciiun  of  acida  ur  of  rennenla  cunrcrtii  dextrin  into  dextriUe. 
Dextrin  ia  preveai  in  tbe  conientB  of  the  alimentary  caual  after  a  me«l  containing 
atarch,  and  ban  alao  benn  found  lu  tbe  blood. 

Tliere  m  not  tbe  Icaat  doubt  that  aevcral  modtflcationa  of  dextrlu  exiat,  and 
may  be  oblaiaed  by  the  action  of  acJda  and  fermenta  on  atarch.  Of  tli«M  two  of 
tlic  bwi  known  are  tboao  dncribcd  by  Bruckc'  under  tho  name  pferTtlirodextrin 
and  aebroodexiriu.  tbr  fijrmer  giving  a  red  color  with  iodine,  tbe  latter  not  yirld- 
Eng  any  color  at  all.  Eryibrodextrm  ma/ be  readily  convcricd  lulo  a  augat  by 
tb«  action  of  frrnienta,  and  thiu  ia  not  found  iw  a  product  of  the  oomplvle  action 
of  ptyalin  on  atarch.  Aehroudextrin,  on  the  other  baud,  ia  not  thu*  coDwrted  by 
fennenlH.  and  tberefure  rcmninB  in  aoluttou,  toj^tber  with  the  Mi)(ar  fi>rnie<l  by  the 
action  i>r  utTallii  on  alarch.  Achroudeitrin  may  b«  cuiivetled  into  doxtrMe  bj 
boUiiig  wllb  dibite  hydrochloric  acid. 


I 
I 


Ank.4,CtVHa.  IL  l-hartn.  IM.  lazl1L& 

IHd..  Bi.  eU..  a  IW. 

atOm.  d.  Viva  AL*4..  tK-i,  W.  Al*h. 


•  II.  . 

Aln.  Vortamacm,  2  AnL . 


10S8 


APPENDIX. 


a.  aiyooe«a.   c,n„Ot. 

Bcloan  to  the  stnrch  division  of  carbnhrdratw.  Oi^rovcrtu)  by  Dcraon)  la  th» 
liv«r  Mid  other  orjcani  (•rn  p.  oiai. 

Olyconn  !•,  when  pure,  un  nmorvluKt*  powder,  colorI«M  Miwl  Ujttel«M,  Nadl]/ 
tolukl«In  water,  IiuoIubl«  lu  aleobol  and  euier.  IUMiu«u«uaoltiUoB  i*  eencnDj. 
though  not  slways.  nirongly  opaletcent.  but  cootaiiis  an  particlM  Tiubip  Biov- 
MoiHcally:  the  nimlwrtinci-  in  much  iv^uc-od  by  th<i  MtMctte*  of  fr<<»  alkali**. 
The  tame  nolulion  pounuca,  accotclii))t  to  lloppU'i'cyri.-r,  h  rcry  atmng  d*XU^ 
roUtory  pow«r,  about  thrw  tiinM  «a  great  u  that  uf  dcxUuM;'  it  dUnltM 
hydraliii  uupric  oxiil^;  but  tbU  Is  not  TMUoeil  on  bollitig.  _ 

Ry  lb(-  aciinn  of  ijlliile  tnineral  acids  (eicepi  nitric)  il  ts  partially  onnrvi^MH 
into  a  fiinii  nf  niitcnr  i-nry  clotrty  m*mblinj(,  thoiijcb  probably  diffrrini;  ■ninewl^^H 
from  tmc  cIcxlriHr,  and  ihe  intiir  conversion  is  aliw  rwdily  edecled  by  the  act^T 
of  amylolriii:  l'«riiivnt«.  Tlir  nuj^r  into  wbich  the  g1y«30gca  of  tb«  \frtt  U  oaU- 
rally  coiiveited  after  il«alh  <Hi'e  11.  i'7'l)  ikjipeflrs  to  be  true  ilestrt**;*  ao  alao  Ibt 
•agar of  diabeioa.  Tlifi  roxiili  i.f  iho  aciion  n{  Jia^iaM.  or  ulivary  or  MocrwUlc 
ferment,  lino n  Klycojt«n  in,  hnncTer,  iic«:uniiag  to  MudcuIiu  auu  v.  alarioit.'a 
mixlurruf  ai-hriiTiclrxtrin  unci  nialtate;  the  quantity  of  dextroafi  niiUEtng  lla  a^ 
peamrice  at  the  wime  time  being  very  ainall. 

OpnlMcetil  itoluUonti  of  );lyi-OKi-'(i  UHiiully  become  clear  on  the  addition  nft«ujli( 
alkali ;  VintNubgan  tied  Hic'tl '  liavo  shown  ihiit  ihi«  is  aooonpanicO  on  botliDcbf 
a  change  which  i-onvcrtu  a  portion  of  Ih?  slycoKm  into  a  sabntancv  to  wbieh  Uirj 
give  ibe  name  of  .'■Klyi.'oKeti-drxlriiiP.  (KuUiif'  bad  prevtoualy  d«*cribrd  a  bodj 
to  which  he  gave  the  tiniae  (clyro^jeu-dexiriri.  That  deacrlbed  by  Viatachgau  aM 
IMttI  dilTins  slightly  frnm  Kdbnc's  body,  hcnctr  the  nan>c.  According  to  itat 
authora  one-fifth  of  the  KlvcuKcn  in  at  tbci  name  limo  diangcl  ititu  Home  olbrr,  tt 
prwent  UDdetermined.  i>ulwUint-e.  Nuriuiil  lead  acetate  Kicca  a  cloiidintw.  iti* 
basic  salt  a  predpitikte.  in  fluluiioni  of  glvcoKen. 

As  l«eti>  for  ibis  body  mflv  bi>  used  the  Tormacion  of  a  |Mi(l-wiue  color  with 
iodine;  this  disHppMrs  nn  narmin^,  but  relurna  on  cooling.  Tb«  sama  colof  i* 
produced  by  the  ncCioD  of  iixliuc  on  licslrin,  but  this  doca  not  f«appMr  on  osol- 
ing  after  it*  diMppearanco  bv  nnnning. 

Pffpnraliaa  ^  •il^.virn.  'riie  follovtiog  ia  UrOcke'a*  metfaod.  The  filt«r«d  M 
simply  simlnediiecoaiuu  of  perfectly  froth  llv«r  or  other  glycogenic  Uaane  i*. 
when  rnld.  Treated  alternately  witli  dilute  bydroeblorlc  add  kimI  n  aolution  nf  ibi 
double  iodide  of  pntnmium  and  mercurf'  as  long  aa  any  precipitate  occurs.  Is 
lh«  preaencr  of  free  hydrochloric  acid  Ibo  douole  iotlidr  piccipitatea  iitotM 
malteni  su  comptFtelv  iia  to  render  tbeir  loparation  by  Gltrslimi  eiuy.  Ts*  ■•» 
teidslieing  (hu«  ^oc  rid  of,  the  glycogen  is  precipitated' from  the  filtrate  byadditc 
alcohol  to  ihf  «)(tent  of  between  <!<'>  and  7t)  per  cent.  Too  much  atoohnl  (sub* 
avoided,  mdcc  other  substance  ho  well  lu  fflycoBcn  are  thereby  precipltaUJ. 
The  glycuKrn  v.  now  washed  with  iilcbol,  nnit  of  t;<)  and  then  of  SQ  porcruL, 
HiWnnrd  with  ether,  aud  finully  with  abiulute  alcobul.  Il  is  then  dried  om 
sulphuric  add. 

Tunioln.    (C,H„Oj)^ 

Ttiia  budr  ia  regarded  by  nany  observer*  as  identical  with  the  true  cellaloienf 
plants,  while  others  hare  iiHcribeil  tu  it  properlim  dilfering  from  Iboae  of  cvlluhoe 
sniDcientlj  to  Justify  its  receiviniEH  distinct  Dsnie.  !l  appears  to  be  more  re>i#kni 
to  rhr  action  of  chemical  rca)[cnt«  tbiiii  plant  cellulose. 

tl  (untlilulci  ihc  chief  part  iif  Ibr  inteifutnent  of  the  asctdia  or  (unlcala.  is 
prepared  fnim  tliiM  source  it  i*.  when  pure,  quite  while,  and  usually  retains  ill* 
shu)-*  of  the  liosue.  It  Is  uiiai-tnl  upon  by  any  reagent  except  strong  odd!  m4 
alktilies.  luul  by  tlie  action  of  tlie  forner  it  yields  some  form  of  sugar. 


■  »r>i:iiii.niutvt^Anh..iM  ixi*.  (um), 8. n. 

'  l-noflafs  Ann..  »l  Kli.  |is»i.  &  Ul,  aiul  aalr.  om).  B.  Ml 


•  atiMUu.  c 


Ai-h  Kai«  IML.  Bd.  ajdr.  (Mft 


•  PMnfaAicK 

•  UU>b.it. 


^%' 


pbrMoL  ' 

-  4.  WViJ 


>>'ii,    B-l  il.(tffin.8.4M. 
■:  IM. 

I-  lalfl.  |ISI»,  U.  Ahlb. 


'  TMi  Di*T  l»  piv]«id  t>y  i^ccuullaUat  r^taaao  kOIilp  irtlli  mMTMiric  «Ii1b*1iI»  and  ilMMmwl 
rnsbcd  p(Mi[Suw  lusliiM  tnluuon  of  pMaitfa  Mblv  ■*  fanfMitcannaiiesMks  takaooiTJ 


foollsf,  Mnw  aBosni  oT  snaiSiaw  oecnrs,  which  dui  tie 

At  aw. 


■a 


(omi  olT:  tbc  BltiMt  u  ih^  i 


CUGMICAL    BASIS   OF    THE    AXIUAL    BUOY. 


1087 


FATS.  TUEIR  DEBIVATIVES  ASD  ALLIES. 
Thb  Accrto  Acid  Skrih. 

0«n«nit  fornitiU,  C>1I,*0,  (ini>ni>l>Mic). 

This,  which  i*  nnp  i>r  tb«  mott  complete  homologous  wi'w  of  organic  cliem- 
itUj,  rua»  piirallrl  lo  the  •eric*  of  moiiKlonnr  alcnhota.  Thii<  rormic  add  corro- 
■pood*  lo  Diolhvl  nkubol,  aatilie  Moid  to  rthjl  (uriliuarv)  •k'ohul,  and  hi  on.  Tbc 
Mveral  Kcida  may  hv  regarded  M  beinK  derived  rron  tbeir  respective  alcuhul*  bj 
umple  oxidaiion  ;  ihuo  elbyl  alcobol  yielda  l^  oxidation  acetic  acid  C.H.O  -I- 
O,  —  C,il,0,  +  H,0.  Tli«  viiriouH  members  diHer  in  composition  by  cll,.  and 
t£e  botiing-pointK  ri>e  aticciwivrly  by  about  19°  C.  Similar  rclalioan  hold  gn<Ml 
with  r«f«rd  to  tbeir  mrlliiig  points  and  sprcific  grnvitie*.  Tbe  acid  pnipcitica 
arrntrotigeiil  in  ibosiMrhere  u  baa  ibe  least  viilue.  Tlie  luwi-at  uierubcn  u(  tbe 
aeries  are  volatile  iiouids.  acting  sh  powerful  acid*;  ibMc  auccewively  become 
lea*  and  Iras  fluid,  ana  the  highest  menibere  arc  cjlnrlem  mlid*.  cluely  resembling 
Um)  neutral  Tata  in  outward  appeamnce.  t'oDKCulivo  acids  of  the  arrie*  pns«ni 
but  very  sinaJ)  diflTerencea of  chenuiuil  mid  phvuical  pro|>er(ies.  hriici!  the  ditGoulty 
of  Mfwrating  them ;  tills  Is  fkirtber  lncreaw>il  in  the  auitnal  body  by  tbe  Tact  that 
•ZMllj  Ihiwo  Hcid*  which  present  tbe  Krcuirut  ximilHrititH  usually  occnr  together. 

The  free  acids  %n-  found  only  in  Hmall  and  very  variable  qiinniitics  ia  various 
piarta  of  tbe  body :  their  di-rivuiives,  on  the  otfaer  band,  form  miut  im[>ortant  coa- 
elltuenis  of  thebuman  frame,  and  will  be  oooaldBted  flirtJier  ou, 

Formio  aold.    cno.OQ. 

When  pure  is  a  sttonKly  cormeive.  ftimintc  fluid,  with  powerful  irritating  odor, 
(olidifyinf;  at  IJ°  (!.,  bnilina  at  IfHi"  0..  and  capable  of  boinji  mixed  in  M  propor- 
liona  with  water  und  alcihiil.  It  biui  bocn  obtained  frum  varioiu  parts  of  llie 
body,  such  *»  tbe  oplecn.  ihymuN,  pancreas,  uuadea,  brain,  and  blood;  in  tlM 
latter  its  presence  idht  beduc  to  the  action  of  ncids  on  tbe  hieoioglobln.  Aoooctd- 
ioK  to  some  natbors.'  it  occnrs  atwi  in  urine. 

Heated  with  sulphuric  ncid  it  yields  carbonic  oxide  and  water;  with  cauetlc 
pOUali  it  icivn  hydrogen  and  oxalic  acid. 

Aoetlo  acid.    C,H,O.UH. 

Ja  di»tin([ui<bcd  by  itit  characteristic  odor;  iu  bollinc  point  ia  117*  C;  it 
•olldlllea  St  &■,  and  la  fluid  at  all  tenipentturcs  above  IS*  C.  It  Is  soluble  iu  all 
prop'ininDs  in  alcohol  and  water. 

It  occur*  in  the  stomach  as  the  result  of  fenncntaiire  chnnKts  in  Ibe  food,  aad 
ia  frequently  present  in  diabetic  urine.  In  otfaer  organs  and  itaids  it  exbt*  ooljr 
In  minute  trace*. 

With  ferric  ebturlila  il  y)el<la  a  bbod-nd  lolntioii, deeoloriaad  b^  hydracblorie  add.  (It 
diSm  in  Ihi*  lad  reaction  (n>m  mliibonyaoiilK  of  Iroa  )  lleaisi  ■iih  aloihot  and  Hljihofk 
acM.  Um  rtiBrar<«<>tic  uflur  of  aeetle  ether  l*ob<aln«iL    It  does  tint  ndnoa  illver  nitrate. 

Propionlo  aotd.    C.H.o.OH. 

This  acid  cl'Kwly  rcHcnihIes  the  preceding  one.  It  posscHes  a  very  Miur  laate 
ud  pangcot  o>Iar;  it  is  soluble  in  water,  boils  nt  Ml"  C,  and  may  be  »«|i«raud 
bum  its  aqueous  uilutinii  by  excess  oC  calcic  chluridc- 

It  occurs  in  small  i{unntitin  in  twcat,  in  the  cvateiila  of  the  siomacb,  and  ia 
dlab«lic  urine  when  undeisoing  fermcntalion.  It  ia  similarly  ptodneed.  mixed, 
bowever,  with  other  products,  during  alcoholic  fementation,  or  bv  the  decom- 
position of  gltcerin.     It  pnrtially  rediMMsiilTcr  nitratoewlution  on  boiling. 

Butyric  iwsid.    C,ll,o.ou. 

Ao  oily  uolorlcas  li<)Uid,  with  an  odor  of  raacid  butter.  anluUe  iu  water,  aleo> 
hoi,  and  ether,  boiling  at  1112*  C.  Catdc  chloride  Mparatea  It  IVrnn  lu  aqueona 
aolution, 


I  BnllflnskT.  tioi'po«Df  k 
rktrnTaiK..  lui.  TfiL  p.  ool 


tar's  Med.  obeiD.  Ulilhslluuc.  II*A  &  ft  ua    TliiHlklMin.  Joun,  at  lt« 


1038 


APPBifDIZ. 


Found  ill  meat,  tlic  conivnu  of  (he  Ur^e  intcstino.  feoM,  And  in  nrlnr.  Il 
occurs  in  trmvo  in  many  oUirr  fluid*,  ftod  m  |>l«nliruliy  obtained  wl>»n  dub«tie 
urine  i*  mixod  willi  pun-ilcrrU  chnllt  and  ki-pt  at  n  temperature  of  3fi*C>  Il  eiWi 
oa  a  uvutral  fat  iu  auibII  (|UUiLltieit  in  aiilk. 

ThiH  1«  ib«  iiriiMiipal  jnoduci  of  tbo  tecond  stage  of  Uctic  fenaentatloo.    (6«e  , 
dexiroie.) 

Tolsrlonlo  ooid.    C^n.O.on. 

An  oily  liquid,  nf  iinnetrflting  ndnr  and  buMiinK  taDtr;  »olut>lr  in  SO  fWtaaf  ] 
wilier  al  !?'('.;  readily  wiluUi-  in  iilc<ibol  ami  i-ihcr.    Buil*  at  1TA*('.     PnaoHh  ' 
in  Tree  and  combfoed  Votid.  a  I'eeble  rigbl'banded  rotation  at  the  |tUn»  af  ftikr- 
imiou. 

Il  ia  found  in  Ibe  lolid  ex«<?mrnifi.  und  is  fonnfvt  r<?adily  by  ibe  decoBfwdtlci^ 
tbrongb  |iu|[cfa<'lion,  nf  impure  Irucin,  ■mmonU  bi-int;  nl  ihr  uunr  tilli««««l««d; 
bcnoe  it*  occurrence  In  urine  wkea  llint  lluid  contain*  Icuoin.  bj>  in  raina  of  acOM 
ntropby  of  tbe  li«-er. 


Cttproio  add. 
Cnprylio    " 
Ottprlo  (Kiiiiu)  acid. 


C,H„O0H. 

c.  n„o,ou. 

L„H„«.OH. 

Time  tbre«  occur  togetbvr  (a>  fat/>)  In  butler,  and  arc  contained  In 
proporlloiift  in  the  fecM  froiii  a  tnt-at  diol.    Tbe  &ntt  in  an  oily  fluid,  s 
wiluble  in  walor ;  tb«  olhcre  iir«  stilifU  and  •cnrcoly  aolublo  in  wntvr ;  ibey  u* 
•olublc  in  all  proportion  in  nlchol  and  olhrr.    Tb«y  tiuy  be  prc|>arcd  fron 
butler,  and  lepuratRd  by  tbo  varying  aolubtlitiM  of  tbdr  barium  aalta. 


C, 


„H„O.OU. 


Iiatiro»t«arlo  aoid. 

MyrisUo  "         C„D„0.OU. 

TbeH  o«;ur  u  ii«atntl  fata  in  (pomiaceti.  In  butter,  and  otb«r  hU. 
wtnl  no  points  of  Jot«niM. 


n«yi 


PnJmltlo  sold. 
Stearlo 


CV^d.un. 


TbMs  are  aolid.  colorlem  when  pure,  taatelea*.  odoritn  cryitatline  bodloi,  ibt 
former  meliinit  at  03' C.  Ibe  Intter  at  lld.ST.  In  water  ibey  arv  aui(«  itMolubk: 
palmitic  add  i*  more  readily  unlublc  in  cold  aloiihul  (ban  ■teoiic ;  bolb  ar«  ntiHij 
diMolTcd  by  hut  alcuhul,  ether  ur  chloroform.  tilsciaJ  acetic  acid  diMolTw  Umb 
In  large  quamitv,  ilie  solution  being  amUied  by  wanning.  Tlwy  radii v  Dm 
foapo  wltb  ibe  alkaJiea,  oIm  nJth  manr  other  melal*.  Tbe  varying  solnblllUMW 
ibeir  bniium  (alta  afford  the  mean*  nt  iicpnriitin;;  tbem  when  mixed ; '  tlila  n^ 
nlau  be  applied  bo  many  othem  of  the  biKner  mnubcni  of  (his  scriea. 

ThcwacJdcin  eombiiiadoii  wilb  glycerin  (nee  below),  togi-tber  with  tbeanala- 
gOBa  oonpouad  of  oleic  acid,  form  uie  principal  coi)8ti(uenis  of  buinao  fat.  At 
Ml(a  of  calcium  they  occur  in  (lie  fecea  and  in  "adlpocire."  and  pnibablyii 
ebyle.  blood,  and  Herouii  fluidii,  ox  wttiii  of  «odiuRi.  Tboy  nrv  found  in  the,' 
•tale  in  decom|io*ing  pan.  tuid  in  <!ajM.'<fUB  dapo*i(a  of  tulwrculoaia. 

Tk*  (rsiMenae  ot  mariarie  Add,  intvriii«dial«  to  Iho  abaTa  lwi>,  it  ftol  now  ailinlU«rl,i 
nun  lleinU'  bsiibowa  thM  It  ti  redly  a  mlxlura  of  palmitic  and  tUiie  aeld.     Uupiwl 
Bolil  pMMMta  the  anoiBaloiu  melting  pwat  at  ftV.S"  0.    A  nunara  of  A"  faaU  Naktle  and  M  J 
of  palmtUo  aiidi  wald  at  SO.S". 


Acim  OP  THK  Olbic  {Acktlio)  Sbbibs.    H(CiiIly»-JO,(moaobuic]. 

Many  addi  of  ttiia  aerlea  oeour  ■«  glycerin  compoumU  in  rariona  (ats,    Tiief] 
M*  Tory  niMtable  and  readily  abawb  oxygen  wbi-n  eip(i«ie<l  u>  tlut  Mir.    Tbt| 
higher  iooB9b*TB  ftna  deeompOMd  on  aKetnpting  to  dladl   ibetn.    Thoir  ohM 
|ieailiar  property  ia  that  of  wing  converted  by  iracM  of  NO,  into  *olid,  «Uibk 
netainetic  acid*  capable  of  being  dtaiillcxl.    Tb«y  bear  an  imereaUng  rdat 


BeOM.  Anml.  da  nj*.  u.  cliciii..  Bd  loilL  h.  Im. 


■OtLI 


CUBHICAL    BASIS   OF    THE   A.N'IMAL    HODY. 


1039 


I 

\ 


» 


lb*  acbb  of  Um>  acclic  *tntn,  Itroithin^  up  whta  hemed  with  ututic  iMlnitb  Imo 
■Ofttic  acid  iui<l  «i>iiH-  iiilitT  ini-Diliprof  the  kbiiki  m-nra.  than  : 

nC„H„O,-r-JKH0  =  KC,l[,0,    +     KCwQ^O,    +  D,. 
01«io  add.    CuUuU.utl. 

Thin  i*  the  only  arid  of  tb«  Mrin  which  !•  nhyiiolo^oBlI/  fanporUDt  ll  ia 
fi>uD<l  uniled  with  gtyceriu  in  all  the  IkU  of  the  nuDUUi  bodj. 

Wh«ii  pui^  it  >».  Bt  otdituuy  tempera  111  res,  ■  ntlorlne,  Morlnw,  ts*lel«M,  ally 
liqnid,  MrutiryinK  at  4°  C.  to  a  CT7aiallin«  uih*,  Infoliiblo  in  wilcr,  il  Id  soluble 
in  alcohol  and  pthcr.  It  cnnnnl  he  diiitilli'd  without  drccmpocition.  It  readily 
fiMiit>  witli  putnssiiim  and  Midium  ■nap*,  which  arc  mlukle  in  water;  it*  coui- 
|>nU[id>  nilh  inMl  ulher  baitea  are  insolubte.  Il  uinv  be  didtiogultbvd  tnm  tlie 
hckU  uf  Ihe  ai'etic  aerlca  by  ila  reaclion  wilh  N0|  anu  by  ibe  ch&iigM  it  uudcrgoea 
wlieti  fxpuMcd  to  the  air. 

Tbk  Neittkai.  Fath. 

Thrw  may  be  coniidcrcd  lut  elhent  faniipd  by  icplnciiiK  the  cxirbnngcablc  ntora* 
of  faydnigeii  iii  ibi^  triat/jinic  akiiliut  (•tyceriii  (»M>  below)  by  the  acid  radicle*  of 
the  aci>tk-  and  il«ie  ncritv.  Since  tbere  are  three  •ucb  excbangesble  atomiof 
hydrr«en  tii  glycerin,  it  in  powiblo  in  fiirin  three  claMCi  of  tlM«e  eihera;  only 
thoae.  noircTrr.  whi<'b  l>cl«n|[  to  the  third  cIom  occur  m  nntiirni  conHiituents  of 
the  buraaii  body;  thune  of  ilic  lint  and  aocoud  are  of  throrvllcal  impurliineo 
odIt. 

Tliey  poMeM  certain  general  cliaract^rtstlcu.  Inaoluble  In  wat«r  and  cold  alco- 
hol, they  are  readily  imluhle  in  hoi  alcohol,  eiher,  chloroform,  etc. :  (hey  alM> 
dinolve  one  another.  Thi^-  are  nrniral  bodies,  colorlen*  and  luielm  when  pure, 
are  not  capable  of  being  distilled  witboitl  underKoioi;  deeompoiiilion,  and  yield  as 
B  reaull  of  IbU  deconipoaitioo  solid  and  liquid  hydrocarbonii,  water,  hliy  odds, 
ami  a  peculiar  body,  acrolein,  [Glycerin  cootaina  the  eleinenls  of  one  moleuule 
of  acrolein  and  twn'molrciilceof  waWr). 

They  pouew  no  acii'>n  on  poloriied  light. 

Tlirr  niiiy  rrndily  be  dccompoocd  into  };l>'<^'<'>  '"■'l  their  rcapcctire  fatty  ocldi 
by  Ihr  Bcliun  of  eaiiitic  alkali<«  or  of  auperheulcd  «lcaiti. 

PalmitlB  iTri-p.laiitfn).    ,(!*|P|i,  }0p 

The  foUowiug  reaction  for  the  fofmalfon  of  this  £at  b  typical  for  all  the  othen: 
Olyowtn.  Pntmllle  adil.        Pnlmlllii. 

Jmiiin  in  allgbtly  ooiubie  in  cold  alcohol,  readily  to  In  hoi  alcohol,  or  in 
ether:  when  pure  it  crystalllies  in  One  needles;  if  mixed  with  Ucaiin.  il  gea- 
erolly  formii  shapelesa  liinnp*,  nhhnngh  the  miilure  mnT  nt  titnen  oMOnie  a  cry*- 
tatline  fotm,  and  wa«  then  rt^nrded  a*  a  diMinct  btidy.  niuuely,  maripirin.  It 
ptHBCMea  three  diflero-nl  melting  pointa,  acoordiiw  h>  the  provioua  tCRi|i«raturei 
toMhich  it  bus  been  aubjected.     It  •olldifle*  la  all  caeca  at  4A*  C. 

/Vipom'iun.  Piuiu  palm  oil.  by  remoTlng  the  free  palmitic  acid  with  alcohol 
and  oryitallising  repeatedly  from  olber. 


St««rbi  (Tri-itcario). 


*^Yy»}o. 


This  is  Ibe  hardmt  nnd  Icnot  fiiiiMe  of  the  ordinat;  fats  of  the  body,  ia  also  the 
ImoI  aoluble.  and  hi-iK«  i»  the  lintt  tu  cry>talliic  out  frtiai  sulutiooa  of  the  raised 
fatji.  It  crytialliiM  usually  iu  nqunre  tablca.  It  preoenla  peculiorltka  In  lu 
fiiiinK  iiointa  niiiiilnr  to  choee  of  palinilin. 

l^fpnralwn.  From  mutton  suet,  il*  Mparation  ftom  palmitin  and  olein  being 
effected  by  rcpeiiteil  cri-sinlliuition  from  etlMr,  •l«arin  beii>K  the  leaat  eoluble. 


Oleln  (TrUoleln). 


<^*-5TrM«- 


[t  ill  obtained  wilb  dilBcuUv  In  tb«  iiufe  alat«.  uid  U  tli«a  fluid  nl  m 
teingwruiuFM.  Il  Im  mora  soluble  th»n  [lie  two  providing  ones.  It  rrsdilj 
fon  oxidation  wh«n  pxpoMxl  to  tlic  air,  nnd  !■  uonTcrl^  by  inrrr  iracM  of 
into  a  Nolid  iiiomocic  fat.  Olein  yields,  on  iItjt  diittilUtioa.  n  I'lmrnrirnitic  mA. 
ihe  idbiicic.  und  it  mpunilled  with  inuvli  KK«tor  difficulty  tbuo  arc  palmilia  u4 
■tcarln. 

Prtjuirriiir/n.  From  nliv*  oil,  either  bj  ooUrk  to  U°  C.  Biid  praning  out  Ui» 
olrin  tliat  tcnininn  l^iiiH,  nr  b.r  dimolvinjc  in  mlcoDol  «Bd  cooliof.  *rh«a  thf  «lcln 
rviBiiiiu  in  noluiion  wbile  the  other  fmu  crvslnllitie  out. 


Qlyoarln.    ^^f^'IOr 


ThU  priodpiil  cuu!<tiluenl  of  tbe  nculml  f&l«  may,  m  above  (Utied,  be  toatgi 
upon  a»  a  irinlomio  ak-ohol. 

When  pur<i.  glycerin  in  n  vincid.  colorlcow  liifuid,  of  a  well-koown  aweet  fate 
It  i«  koluble  in  wntor  and  nlcnhol  in  nil  pnt|iartinnii,  inioluble  in  etber.  Esf>w4 
to  Tcry  low  teniperaliiri.'  it  becomca  alriimt  solid;  it  may  bi-  dia>lil]<Hl  in  d«) 
vcaielB  without  aecomiKisliioii,  betireeti  ■SlT,''--'m''  C. 

[l  di»solvea  the  HltcallM  and  alkaline  «<arihii.  hIho  many  oxld**,  uicb  h  thaw  if 
lead  and  copper  ;  many  of  the  fnity  acidx  are  aUo  soluble  in  glycerin. 

It  nnnewni  no  rutatorr  power  or  nolaiixL>d  liKbt. 

It  \»  eaaily  recogniiea  by  ita  ready  sulubiiity  in  water  and  alcubol,  ite  LdmIii- 
billtv  iD  ether,  lut  «weet  ta«ie.  and  ili  reacliou  with  boM*.  The  prodottka if 
acrolein  n  alio  characteriHtic  of  glycerin : 

Cjafi^  —  3H,0  =  C.H.O  (Acrolein).  | 

I'rrjjaration,  By  laponificAtion  oftlie  variocw  oilt  and  (at*.  It  U  alao  (bniicil  in 
Ninsll  qunnlitiM  during  tbe  nicokollc  reimeiitatliin  of  eucar.' 

Soap*.  Theae  may  be  formed  by  the  iwtion  of  cnuMic  allEnlic*  on  fata.    Tk 

Erocew  consikia  in  a  >ubtitilution  of  tlie  alkali  far  tlie  radicle  nf  glynoin.  iW 
titer  combining  with  the  elemeui«  of  water  to  form  glycerin.    Tliua : 


I 


TrfMcarin. 


*''i'ffr'*}°'+«"i 


airwnu 


FaneitatJc  JiiIm  can  *p1lt  up  Ail*  Into  jljoiinu  •nd  trr*  bttr  an<lf,aa4  tk«  Uto  likn***! 
tobocapablsoriBponilS-inglhcH  1iMyaB\Ai.   Thb amouutor  «Mpt  Ibrwieil  la  thaallnuivT 
taoal  It.  boir«T«r,  Bmall  atiil  uiiim|nKiiiil. 

Acids  of  tue  Glyoolic  Sskigs.  \ 

KunnlDg  parallel  to  tbe  mouaiutnic  aloobola  (OH,ii-,0)  U  tbe  Mrlea  of 
diulomfo  auonola  or  glycols  (0>H.4,0,;.    Thu«  corresponding  to  ethyl  akobqlh 

Aa  front  the  Bumatamie  alcobob.  H  fhm  dw 


tlie  diatomic  alcohol,  elhyl-gWcol. 

glycil*.  atuda  may  be  derived  by  oxtdntioB ;  from  tbe  lattev  (glycAh), 

iwu  lerim  of  acidii  can  be  oblaineil.  known  reapeotlvely  aa  the  glycolic  and 


•eriw.    'llie  lir»t  Mage  of  ojtiduiou  of  the  gtyeol  girai  a  mevber  uf  the  gl] 
Mvlea.    Thiu : 

EUiri-|lTO)l.  aijMlleavld. 

C,a,U,  J-  O,  =>  0,n,O,  -r-  11,0,  or  mora  geBerally 
C.U^  ,,0,  -t-  O,  =  C-H^O,  +  B,0. 

By  further  oxidatloo  a  ueoiber  of  the  glycotlo  terka  can  be  «Nirert«d 
member  of  the  oxali«  uriea.    Thiu ; 

atjcuUc  add.  Oxalic  mU. 

^t^fii  +  0,*  C,ll/>.  +  11,0,  Of  motagaotraar 
CUlyU,  4-  O,  -OU,— ,0.   r  U,0. 


TIm  acJd*  of  the  glycolic  terim  are  diatomic  but  monobaalc :  Iwt  tboae  uf  tha 
oxalie  aerin  are  diatomic  and  diabaajc. 


■  hiHui,  Altn.  A.  QuiQi.  u.  I'lurm.,  VA.  ctL  S.  »& 


CHRMICAL    BAEIIS    UP    THE    ANI»,V1.    BOllV. 


IiHl 


I 

r 


Th«  followliif  inblp  may  ht  f it^n  li>  show  tlio  gtoonil  rvlalMxialiip  at  kIcoIiaIi 
■ntl  acids: 


■MblK 

H*ih>t  (CH.) 

Bihri  (C.H.) 
Pfopyl  (CH,) 
Bniyl    iC.H.k 


AlmlHl. 

c  B,[or[) 
c,ii,(onj 

C.H^OB) 


A«it. 

atjttit. 

icUL 

Artin. 

Formic,     i 
HrnO,      1 

Cubniilo. 
H.CO, 

aO,ii,o, 

IK'.II.O, 
Oxvbuttrk. 

ca.H,o, 

A<-Hio. 

m-.n.o. 

Pmiilonk 

Ouiyrtc. 
HC.11,0, 

Rtlivl-Elvcnl. 

Pfoi.vt-cWpo^l. 

f.rt.ioii:, 
f.il.lOU), 

o'lniiii. 

M  ■Iodic. 
U.C.HO. 
auo-lalc- 
H,C.H/., 

ObvcoLio  Acid  SBKin. 
IaoUo  odd-    C,H,Or 
Next  to  rnrtxinir  hckI,  t1i«  moat  important  mmbtr  of  this  aertv*,  m  IWr  us 


B    phy*i'ilo|C}'  b  I'Mncmircl.  i«  lactic  acid. 

L«ctic  iit-i<l  exiala  in  four  Uomeric  modiflcaiioua.  but  of  ibew  oaly  three  Iia^d 
b««n  fouiiil  id  die  liutnaa  boilj.  TliMe'lbtee  nU  form  afrnpy,  colorlem  fluid), 
soluble  in  all  pro|>rjrlinDK  in  water,  nlcobol,  snil  pltitr,  Thr;  |kii<i<«is  an  inlt-nstly 
sodr  laMc,  and   a  slTinji  ncjil  rrnction.     Whrii  liruli-d  in  iii>liiii<in  Ibry  arc  par- 

»luilly  illstillcd  uver  in  the  tvcupiiig  vapor.    Tlivy  funii  salts  with  iiicialii,  of  which 
*tboM:  wllh  the  alkalies  luc  very  iN>lubl«Biid  erytulll^e  wiih  •iilUiulty.    Thr  »!• 
clucii  aud  dnc  salt*  are  of  the  )(r«atMt  importance,  u*  will  bo  Rvoit  iatei  ou. 

1.  Bthytiden«  t&otic  scid.  ThU  I*  the  oHlnarjr  form  of  the  acid,  bblAined  an 
the  charscterttiic  product  of  ibe  well-known  "  lactic  fcrraeninlion."  It  wcurt  in 
the  eoiileiitu  of  the  fttomacb  aad  ioieHlinca.  Afconlinu  to  Ilviti(i>'  it  ta  fouiMl  aho 
la  anaelcs,  sod  according  to  Osclivldlcn'  in  the  ttHnfC'ionir  cell*  of  the  gray  aub- 
stMica  of  tbs  brsin.  In  many  db<*M*  it  i>  found  in  ntinr,  and  exiiiti  to  a  large 
atnouBl  in  this  excretion  after  poiKuninK  by  photjiboraa.' 

Il  tuAy  liu  |n)i*rT>l  I>y  ihr  nnxnil  iii*Ihu|j  ot  iIawIv  oiHlKlBt  lb*  torwificwJiiij  icty««l 
or  by  aMjDf  np  nioDichlvrina'vi  prMiioaLo  dckI  triili  nioiil  irlvrr  ojiliie.  In  ubtAtuIng  it  Frcrni 
Ike  proilail*  i-f  Ui'lic  frni-vuTnlinu,  t)ii>  i-r<»li>  •'f  liiir  brlat*  nr*  piin(ii<d  1>y  M vstsl  ttytlaMi- 
aaiioai^  aiul  III*  aeid  lllxmliil  frt-in  tli*  «>in|wuDJ  by  il>o  ni^lioii  of  iulphur«ll«l  byilNii^. 

-■  Ethylene- 1 kCtie  ketd.  This  acid  is  found  accompMnjing  the  next  to  be 
daacribrd;  in  [Ij<-  watery  exinurt  of  mtiaclea.  From  ibW  It  la  seinraird  by  inking 
adrautagc  ut  the  <liiri'rf<iil  Kilubllities  in  alcohol  of  the  zinc  taliii  of  the  two  ncida. 
It  aeenu  probable,  however,  that  it  bun  not  yot  been  prepared  in  the  |>are  slate  by 
this  metlMMl. 

Wi*limi«t  Anl  nhuinvd  Uii*  a<id  by  iiMlias  hydroxy cya«i4«  ol  ethyltoo  with  aqwcoM 
iolBlioa*  of  ili«  allmlln 
The  BtiiM  ohnrvcr  luaa'l  II  alK>  In  laaoy  palbaloglMl  OoUl 

S.  Sareoludo  aoid.  Tbi»  acid  baa  not  yet  been  [>mciired  syntbettcally.  As 
Its  name  iini>lie».  it  I*  thai  fnrni  of  th«  acid  which  chiefly  occun  In  muscle».  and 
h*DC*  axi«la  in  lance  auaiiliticK  in  I.eibie'*  ''  extract  of  meat."  It  in  often  found 
kIso  in  pnlholngicrHl  HuidH.  Thi*  in  the  only  acid  of  the  Hcrini  nhivh  poifwca 
MV  power  of  rotating  ihe  plane  of  polarined  light;  it  is  otbcrwlM  Indiatincuiab- 
ableiroTa  the  preceding  elhylidenr-lnclic  acid,  and  la  generally  rciHwseiited  oy  Uie 
nme  formula.  Tlie  Irce  ncid  ha*  desiro-,  the  anhydride  livio- rotatory  acUoD. 
TIm  specific  roiatiiin  for  the  tine  salt  In  solutfofi  i*  — 7.0d*  for  yellow  light. 

The  tine  and  calcium  talla  for  aarcolactic  acid  sio  nan  soluble,  both  in  mter 


I  Aim.  •)  <.  tunn.  a.  I'litnn..  IM.  ftitl  9.  KR. 

'  nuxi->-i  Anhir.  Bd  tW.  fina-tiig.  iTi. 

■  Mgliiiliicn  inO  lltvs.  I'pbtr  M«l«  rhMiihomiitniilaB. 

•  Ann.  il  i7i<M  II  lluinn,.  llil.essttll.B.a. 


t'faM.  Oniialb..  iMk  f-  an. 


1012 


APPBNinx. 


aikI klc»hol.  Ibnn  tlioveofctliylideni'-lAclic  acid,  but  I«miu  iban  Ibmeof  filifl^ 
lactic  ■uid.  kdiI  the  Mme  njilbi  of  ethylene  lactic  kM  cootAiu  morr  iiaufi 
cr7*ullluili>n  ibau  tboM  of  ibe  oilier  iiro. 

Ilnnti'  hu  uodipirtd  the  alioie  acliU  li>  Uie  laoiitiaainu  atp»\>U  of  «xihui(  Iu  iMbnr 

ICinlraiTytla  luiiil,  Ih*  Tuuitb  la  thU  Hirlca  of  lutle  iDiib,  It  i!i«litt|iii*lukl  hf  lb*  B4ta*(  <l 
IU  ilcuMnpMiliOin  on  hoaliaj^.    It  u  n«T«r  ouod  m  a  naaMltumt  of  aalotal  badlaL 


OxAUc  Acid  Ssriih. 
Oinllo  add.    H,C,o,, 

Id  ili«  fret  MaU  thU  arid  <lo»  out  occur  Id  the  buraan  bod;.    ('«totc  oxahb^ ! 
howevMT.  iflB  not  unfreqnent  constlti)««il  of  urine,  und  eotem  into  the  ooa)po*iti<a 
of   aiany   urinnrir  cnlciiM,   Ibc  «a>oall«d    mulbonr   caleulua   o^nilatiag   almM 
entirrlv  of  it.    It  may  occur  in  feoe«,and  in  thv  ^U-bladd«r,  lbou|[h  thUbnr*!} 
obarTTi'd. 

Ah  ordiuariljr  pccipltatcd  ftom  solallnns  of  calcic  ulta  br  ammoalc  nialok, 
calcic  oxalate  in  i|uiu<  aninriihowt.  bit  in  iiriiiar;  dejiMlta  It  BamiiMa  a  MtiHi; 
cbaractcrialtc  cryaullino  form.  viz..  tlint  of  reclAngalnr  odobvdnt.  In  •ocnv  tatm 
it  preacolH  tbe  anoinalwia  forrna  of  niiindud  lumiM,  dumb-bell*,  or  aquar*  colamai 
with  pyramidal  otidit  It  ii  insululile  in  wabtr, alcohol,  and  Mbpr.  atw)  in  anoi'inu 
and  ac«ticacid.  Mineral  ncidsdlaM>lv«  this  nail  r««illly.  as  aJxi  to  a  imallcr  e ti*»i 
do  fliilacionii  of  Rodic  phonphate  or  urate.  All  the  above  character iatica  tittrt  vt 
detect  ibi*  salt;  ita  micmacopical  appearance,  boitcver,  ia  ^nerally  ut  miNt  fw 
for  this  |KiqH>te. 

The  pure  acid  ia  prepareil  either  bv  oxidizing  sugar  wUb  nlutc  Add,  ordrtiM-, 
pueing  ll|;neou*  limue  with  ciuMic  alkali*.  . 

Sucoinlc  add.    H,C,U,0,. 

Thin  in  Ihc  third  acid  of  Uie  osallt'  iterfea.  being  leperatMl  from  nxalic  a<-id  bt 
tlM!  Intvrincdiulf  maloulc  acid.  1I,C,H,0,,  It  occur*  in  the  iplecn,  the  Ihymiu 
and  tliyroid  huditH,  bydrooophallc  and  hydrocele  Buida. 

AeeBrtliaj  to  Mbihdct  a»d  Stiepanl*  It  li  (buBd  u  ■  anrnul  cantUliwal  nt  iirin*.  TV*  • 
cael«alad  1^  Salkixrtlli.'and  al«  \>j  rmi  9pej*t.  It  H«nu  prabaUc,  hnwwiar,  llkM  •t*r* 
trinM  aed  nmaal«d  linnan  eoutain  (ucelulc  aeid,  ami  ihli  laiwr  fa— ii  iinohaii^nl  iiib  &■ 
iiriuB,  tlwl  it  may  lli»  tw  onMAJunally  ]>mviil  in  Ihii  exrratictt, 

Succinic  acid  cry^talliM*  in  Isrtre  rhombic  tahlea,  also  al  lim«i  in  the  furm  ^ 
Iftrgepritmn;  tbcy'nrc  xiluMe  in  ■'>  partaof  mid  water,  and  2,2  of  boiliofr,  ■licliili 
•olablo  in  aki>hol.  aitd  ulmunl  iniuluble  in  rther.  The  rrtMaU  tneli  at  iW  C.. 
ud  boit  at  2-'ti>*  C.  being  hi  tbe  miuic  time  deconpowd  iiiio  the  anhydridt  lad 
water.  Tbe  alkali  salts  of  this  acid  ar«  Milubte  in  water,  inifiliihle  in  alcohol  a^ 
elber. 

Prfparttlioa.  Apert  from  the  avfithetic  aielhoda,  it  maj  readily  be  obtiUnei  kf 
the  frmicntntion  i>f  calclu  malnte,  acetic  aoid  being  produced  aimtillaneoualy, 

lu  pn-MDce  \»  revuetiiKd  by  the  tnlcroscnpic  cxamina^ou  of  it*  cryataU,  ■»! 
lla  characterlalic  reaction  with  nnrmnl  lend  acetate.  With  this  It  girt!*  a  pftdid* 
latccatiil^aolublcin  exccmof  the  precipitant,  but vnming  down  again  <in  wannu{ 
and  ahiking.* 

OHOLKifTltlllit.     (CmH^O.) 

TbU  la  tbe  only  alcohol  wfalcli  occurs  in  ibe  human  body  in  Hat  ftt% 
(The  trlatomic  aleohol  givcvtin  in  almotit  always  found  combined  na  in  the  fiu;] 
and  cetyl-aleobol,  or  »lbal.  U  obtained  only  from  •pormaceti.)    It  in  awhile  t-t^i 
lallins  bodj, crTaUlliilng  in  fine  necdtea  frvun  itaMlatioB  in  ether.  chl<>rt>ronB,i 


'  WifU(i-tii».  OK  (41.  AIn  Ad«,4.CIimb,I|.  riMrm,.  Ihteldte.)!  M.oUrflLftl 

■  I  iii.-(v<)c.1  ubRd- Eiinuh.41.  niinni''*-     llniiixi-r.  two. 

■  I'llDni'i  ArrMr,  Od,  U.  ^IMH,  H.  W,  404  M.  Iv.  iih:)).  &  M. 

■  |-<.rllinlwrraniciiUnMeMMBHa.»p.clu<utd  Uvlniai  awl  MIS'.  K<*iw1ir.  t  rat  MbI  ^U 


twnml :  tr<im  iu  bnl  alcoliolic  xolulionii  U  i«  i)(!poiiit«<I  oa  cooling  in  rliotnbic 
ubie*.    When  driird  il  luelu  ul  l^^i"  C,  urn)  disiiU  iu  cloacO  vaueh  ni  ;ti>0*C'.    It 

I  quil«  Imolubic  in  water  and  cold  dcoliol ;  Bolable  in  •olutJona  of  bile  miIu. 
^    eoluUon*  ordiolntenn  pomeM  a  li^fl-lianilvd  mUton  Klioa  on  polariiced  light, 
of  —  SS'  for  Tflliiw  Ufcbt,  thin  being  iniicpendoot  of  (vinoentmtioD  ■nil  of  the 
niilure  of  lh«  Milvvnt. 

tlenteil  wiib  airuag  tuliiliurlc  AL'id  it  yieliis  n  hydrocafbou ;  vllb  concentnied 
nitric  il  itivm  choleileric  acid  and  itthot  prodiict«.  It  ie  capable  of  uniting  with 
■i-idn  and  forming  compounil  otberx. 

Cbolcsterin  occun  in  small  iiiiantitits  in  tfae  blood  and  many  tinauea,  and  ia 

pKwnt  in  abundance  in  ibe  wtiitc  luntier  of  tbecerebro-tplnal  uxin  and  in  nerves. 

It  la  a  coaaiaot  conatitueitt  of  bile,  forming  frequently  nvarlj  the  whole  maaa  of 

•onie  call-Rlon«e.    It  is  found  in  many  pathological  fluid*,  hydrodv,  tbo  fluid  of 

ovariaTryatc,  etc. 

IVtparation.     From  nll-sconea  by  aimply  citractioD  witb  boiling  alcohol,  and 

aeail  with  ak-obolic  putaah  to  free  frriin  extraneous  inalter. 
Aa  tMl«  for  (his  Bub«Eance  may  be  given:  With  roncentratod  eulpburic  acid 
and  a  little  indine  n  violet  vnlor  ■■  obtained,  cbnniiinit  throush  sreoo  to  red  or 
bine.  TliiK  U  anplicablo  to  ilic  mU'ronfopic  erviitalii.  AAer  oioaolTiiig  in  chloro* 
'sriB  a  blood-red  aoluiion  i»  formed  uu  tbe  addition  of  an  e(|^ua]  volume  of  cooceai- 
nled  anlpburie  acid ;  this  aolution  if  exposed  to  the  air  in  an  open  disb  turo* 
Ant,  ^nwR.  asd  Rnally  yellow ;  the  sulphuric  acid  ondrr  the  chloroform  haa  a 
Krcpu  IluorcMcnce.  After  cvapciration  tu  drynow  vith  nitric  add,  tlic  reaidue 
turpi  red  on  treating  with  ammonia. 

TU*  body  II  lUwrlfaHl  ber*  tailier  for  Ilia  wke  iircanTaDlonce  than  l^m  II*  pnaMslai  aMy 
cldM  rclatkoiikip  ta  Ibe  wbitjiiiau  I  in  mediately  pracvding. 

K  OQMPI.KX    NtTltCHtRKOI/H   i-'lTH. 

"    LMdthin.    C„U^NPo,. 

Occtin  widely  ipread  throughout  tlio  body.  Blood,  bile,  and  aerou*  fluid  con* 
tain  it  in  amalt  quaniitleii.  while  it  ia  a  couapicuoiis  oomponent  of  the  brain, 
netvn,  yolk  of  egg.  bcmivii,  pu*.  white  blood-corpuaclea,  and  the  electrical  orgaiia 
of  the  ray. 

When  pure  it  ia  a  colarIni«.»lightlycTj>ta11in««ub«tauce.  which  can  lie  kneaded, 
but  often  crumble*  during  the  procew.  It  ia  readily  aoluule  in  cold,  exceedingly 
•o  Id  hot  alcohol ;  eilivr  diMulvea  It  freely  tltoogb  in  \vm  i]uantitiea,  ua  aUo  do 
cbloroforn).  fata,  benzol,  i-ur)>on  dl»ul|>hlJo.  etc.  It  b  often  obtained  from  ila 
alcoholic  a'tlutioD  by  evaporation,  in  the  form  of  oily  drop*.  It  »wella  up  io  water 
and  in  thi*  (late  yields  a  flocuulcnt  procipilale  with  lodiuin  chloride. 

]..«!iUiin  ifDoailvdeoompoaed;  not  only  doai  tbiidecniniHiiiiiiuu  act  in  at  70*  &. 
but  the  i>'iluiii>ns,lf  merely  allowed  to  aland  nt  the  ordinary  lemiwratnre,  auquite 
aa  add  r«actloD,  and  tbe  tulmtanci^  is  deciiniiicHeij.  .^dda  and  alkallea,  wf  courae, 
«Abct  thia  much  more  rapi'Ily.  If  heated  with  baryta  water  it  is  eoBipl<4ely 
dMOinpoaeil,  tlie  produrta  bring  m-unn.  glycerin ■phoapbimc  acid,  and  Iwrio 
atMiato.    This  may  be  thu*  nipruienleil : 


r 


c„iVNPo,*8n,o-stvi^o,   +    c.ii,po,   +    c;n„so^ 


When  treated  in  an  ethereal  *olutifln  with  dilute  aulphuric  add.  It  Is  merely 
eplil  up  into  nenrin  and  diMeHTyl-glrccrin'pbmpbdric  arid.  Hetica,  Diakonoir 
regslda  lecithin  a*  IhudintHirTl-glyrerin  pbmiihaleof  OFUrin,  two  alMttaof  hydra* 
■an  in  the  glycrriD-ph'MplioHo  aviii  beinjc  n-plnce<l  by  tbr  radicle  of  Stearic  acid. 
TtaMwaia  also  that  tliere  iirwbnbly  extft  otlieranalogoiu  compoonda  Io  which  the 
radiclca  of  oleic  and  palmitic  acid*  lake  p«n. 

Prtfiaralioti.  Usually  frooi  the  rolk  of  egg.  where  it  occura  in  union  with 
vilclho.    It*  ianlation  ■■  com  plicated,  and  the  reader  i*  referred  to  lloppe^iaylar.' 

■  Ham  mylW*  Ucd.  HiPtD.  I'liUHudi.,  IMt  ILOMTi,  axn:  Hell.  UL  aMl.  &  «■  CwlMlk 
f.  d.  MmL  mm.  I  IIW>.  M.  I.  T  R.  >. 

*  iMXVm.  i-iuHiiicu..  iMi  n.  yxmy,  tm. 


KH-i 


AITBNIUX. 


aiyoarfn-phosptaorio  acid-    i-,H,ru, 

Occtira  lu  a  procIiMt  i>r  ihv  ilnromprftlilim  of  leciibin.  an<l  benro  U  liiiii 
thoM  timuoa  uid  (tnids  in  whidi  Dib  IsUor  la  I'rMotil :  in  Ifiikhtraiia  lti«  ivin*  W 
■vd  to  conlain  thU  ■iib*t>ncc.  It  hiu  not  boon  ufabLinoJ  in  ditt  uiIhI  furm.  It  bit 
Iwen  proiluccil  ityi)ili<.-ttcuIlT  hr  braUng  glyccrio  aiitl  gUciiti  |>ho>pbi<>i(-  itclil .  it) 
may  be  Tey:ur(liMl  aa  furiiioil  \sy  tbe  uninB  of  ofi«  molecuk  uf  glyoerin  wjib  w 
|iko«{iliuric  acid,  with  elimlnaiinii  or  one  tDoln!iil«  ol  «nt«r.  It  in  a  iiitHiii«| 
itflMilta  with  liariuni  sDil  caJutucn  nrc  iiualublo  in  Htcohol, Mlublc  in  n>1i)  - 
Soluti«D«  or  il«  nlt«  arc  [>f«cipilatc<l  by  Iciail  noetolc. 

Prota«on.    l<-",«ir„N,PO„T) 

A  cryiitalllne  body  containiug  nitr«f«o  and  pbMpborati,  obtained  hr  LkIift^'  ' 
rrotn  tlie  brain  tiibHtiincc  ami  rcgnnlM  by  hliii  lU  (u  j>rinci|>al  con*'-itii<-Di.    Tia  < 
rcMAfchca  uf  ll(>p|i^K<^lcr  anil  Diakoiiov  icoil«d  tn  abciw  ibat  I'mUff  •■>  •»  { 
iDMdj  a  mixture  nl  lecilbtn  and  c«refarin,     A  rvitrlilion  of  I.iirlireicb  ■  esnrt- 
lueotB  ban.  buwever.  led  QamgtiF  and  HIankenbotu*  to  confirm  ib«  tititb  oflxij 
result*.    I'roTafciii]  appeura  to  wparxtc  out  frutu  warn  alcohul  ua  pwlual  cuullBfl 
in  tbp  (turn  of  very  "mall  (i««dl<«.  otitn  arntngvd  in  ^root'*-  ■<  ^  aliftbUy  •iii*k«^ 
in  cold,  more  Milublc  in  hot  alcohol  and  ctltcr.    It  U  lluwIubW  in  ciilnr.  but  varib 
Up  and  foruii  a  gdatiuuus  uiaw.     It  tuelt*  at  2D()°  C,  and  funnn  a  bruotn  q^rufj 
auld. 

/Wjyiriiiioa.     Fladr  diTidcd  bruin  ouUlaove.  frtcd  ttwa  blood  and  cnniiKtii* 
Umuo,  U  digMlod  at  tS'  C  with  alouhul  !S.^  per  tuot.)  as  long  ■«  Ut*  alMMl 
cxlTBCta  anrthing  frooi  it.    TboprotasoD  Khich  M-pntnits  out  frunktht  fltiraM  ll| 
well  waabed  viib  e(h«r  to  wrt  rid  of  all  chi-tntcrin  and  ulher  boilln  aotvUt  I 
ether,  and  Anally  |>utined  by  repeated  crytullijsatloo  from  warm  alooltol. 

Nourln  (Cliolii.).    C,1I„N0,. 

Dincovcrcd  by  Si f« lew*  in  pig'a-gnll.  then  in  oi-^hII.     It  d(>«  imvI  •■CL-ur  Uj 
ihe  free  stale  except  an  a  product  of  the  drcompi-iiion  uf  lecithin.     It  u  a  enli 
lew  Huid.  of  uily  cuixJslence,  poMmut*  a  «ining  nlknliiie  rravtiou,  and  forsw  «Ml 
aeiiln  vvry  deli'iucaccut  uilis.    The  nulla  with  bydmcbloric  acid  and  dio  ehl«(1d«| 
of  tiliiiinuiii  and  gold  «re  ihv  miiHt  ini|>oriaDt. 

hcnrin  in  n  oiimt  uohUblc  body,  ineec  bcaiinK  of  iu  nqueoiu  aoluilon  isAda 
In  tjilit  it  up  into  itlycol,  triuietbyliunin  nnd  cibylrnc  oxide. 

PrtpnrQtion.    Krom  yolk  uf  c^ig.    fur  ihiii  nee  Diakoaow.* 

W«rt<*  bu  otMiuixl  >l  *ynlliall(Mlly.  Ilr*t  liy  llio  wtlon  of  clcol  )iy>ir<  - 
iMlkylatoiii,  and  liicn  by  ifa&l  ot  nilirkbc  nxiik  and  <rMar  on  ll>«  mih' 
aboes.  McfUiar  rlUi  llin  m^ife  nf  iu  dKViDiiiailinn.  loial  to  Uw  Mw  tbn- 
r*s»nlnl  m  iriowthyl-oxyctbyl-aiBinoiilBn  Iiy4ral«k  »iCIf^i(OIltO,OIt. 

C„n„NO,(T). 

la  found  in  the  axia-cylinder  of  nervea.  In  ]>iia  cornonclea,  and  lareeljr  in 
brain.  In  former  timm  many  name*  Here  eiven  to  the  «ubMance  wheo  b  «a 
impure  itate,  r,  </„  cerebric  acid,  cerrbrole,  etc.  W.  JlUIIcf*  fintt  prepared  iiia 
Hie  pure  fonu.  and  couairueied  the  above  formula  from  bi*  anidvaii ;  the  mean  4 
Ibeae  ia  O,  15.M  i  H.ll.i;  S,  4.5;  O.  «S«.  Great  doubto  are.'howrver.  thwHi* 
npon  it»  parity  by  the  reM«rchea  of  later  obwrvert.  Accordlni;  to  Liebreich '  and 
Diakonow.*  it  is  a  gluooaldr.* 

Cerebrlii  is  a  llghl.  oolorlea*.  exceedinRlr  hygroMtipic  povder.  which  owelU 
BtrOBgly  in  water,  slowly  In  the  cuM,  rnpidljr  an  beuing.    When  heiiied  to  N** 
it  tum*  brown,  and  at  a  woiewhat  higher  temperstare  mcltti,  bubble*  up, 
linally  buniH  away.     It  ia  inwdnble  in  cold  alcobid  or  ether ;  wana  alcobol 


- :  UI.I  >nura.  uT  rh)>l.4,  wL  n.  fUOW.  k  IU 
lul- eilvlO.  £.  W. 


'(K 

V  irtMIOn.  m. 

'All-    _                ,   .  AMI. 

>  atttk  (.  isilixl,  A>«'  IMITK 

■  fMlnlti.  r  <l  luBt.v  ...  T 

•  e*»aW(itc«lw8l9>£. ......:.  :   vIiTiM.  rlMB..  Bd.  11.  nS?l|i.  &  XR- 


:l 


NITK<VJKNOUS  MRTAB0UTE8. 
TiiB  Vhbk  Gbopf,  AutPRs,  Avn  SiJitMK  BontKS. 


CUKMtCU.    BASIS   or    THK    ANIUAI.    B01 

•oItm  it  Mniljr.    llut«d  vrilb  dilatr  mineral  ncitt*.  ccrabrin  jiekb  •  Mgu^llkt 
bod*,  puMMsint;  l^ft-handed  rotation,  but  inoapuble  of  f«nnciilati<i(i. 
B     /*ipitratiou.    For  iIiUam  VV.  MOller.' 

'     The  cUi«r  CAiuUtu«tit  of  nufmal  uriiw  in  m  kin  mall*  anit  none  trtb«r  Aiiimnli ; 
th«  uriiM  of  birdtt  aho  coDUiiimi  nmiill  aiiiuuiil.     N<irmiil  blood,  KraOH  fluids, 

^Jjmph,  uid  the  litvr,  all  cmttain  the  samv  liod^  in  tnioc*.    It  Ja  nii4  Touad  in  thv 

^■BiiHclcs  •*  a  normal  coiwiiiupiii,  liut  may  tnaku  ita  apjiriirHnvv  lh«ro  aiidor  ucrtain 

^KfAthological  M>ndilioaa. 

Wbcn  |iiir«  ii  tryHialllMa  frnm  n  nmcvutrnti'il  tuilution  iu  ilie  form  of  long,  tbia, 
slitWrinf  niwdlM.  If  depottled  aluwlr  fnnii  •liliilc  «i>lutione,  Ibo  form  !■  tliat  of 
Imir-KidM  priuiiiwilh  pyramidnl  PiidH;  lliMC  arraliraf*  antiyilrmin.  It  puotFioeB 
a  aomowbHl  bitter  coolinp  taitr,  likp  uiltpclrr.  It  U  rrndilf  soluble  in  •nUvt  uud 
alnltvl.  Ui«»nlution«  boinff  n«utral.  In  anliydroiu  etlMr  It  U  Iniuitiibtr.  The 
CfiUU  may  be  heated  to  ISCi'C.  witb'ml  being  decompowd ;  at  n  higher  tero- 
peraturf  ihry  are  tint  liiiiiefled  Atid  ilien  decoiii|>w«. .Imvlng  no  rwidue.  llM[«d 
irilb  MrDntl  acidi  (ir  nlknliiw,  cleroniiinititinn  eriauea.  thp  final  prodnctn  being  rar* 
bttftte  anhydride  and  ummonia.  The  larae  d«cuinpaaiiion  tnay  al»u  occur  na 
Ui«  rettult  of  the  action  of  a  HpeciGc  ferment  oo  urea  In  an  aqueoiu  aolution.' 
Nitrou»  odd  at  once  decompowi  It  Inlo  carbonic  anbvilride  and  free  nitrogoa. 
It  readily  form*  compound*  witli  acids  and  basaa;  of  thaw  the  rollowiog  an  of 
ImportMice: 

Nitrate  of  tiroa.    (NII,),caU>'Or 

CrfBlatliiea  in  nU-tilded  i>r  rliombic  tablea.  lnaolubl«  In  elh«r  and  Qltrlv  acid, 
•oluble  in  water,  aliiililly  toluble  iu  alcohol. 

Oxalate  of  area.    [(NH,>,CO],.H,C,0. 4-  H,0. 

Often  crrstalliijea  in  long  thin  pritiiu,  l>ni  under  the  microscope  i«  obtained  in 
a  fortn  eloMty  rcavmbliog  the  nitrate:  It  In  alightly  aoiuble  in  wat«r.  low  so  in 
alcohol. 

With  mercuric  nitmlt!  urea  yieldi  three  Mtta,  ooaiainlnfc.  rcapectlvely.  (aar, 
three,  and  tW'>  e^iiiiatt-ntn  of  mrrcuric  oxide  Ui  one  of  iirefl.  The  flnl  i«  tlie  pr»- 
clpitale  formed  in  I.iebig'e  oiian illative  detemii nation  of  nrea,  and  may  bo  rvpra- 
•Mit«d  by  Iba  formula;  3N,H,GO.11k(N0^»1IkU.  Tbo  ucavt  conttituiioa  of 
tbcM  aalto  baa  not  yet  lieen  ueMrminea. 

/Vr/mrafi'm.  Ammonic  Mil|>iiHte  and  pulawc  cyaitat«  are  mixed  tucMber  In 
a(|ueuu«  »o1utioD.  and  the  mixture  ia  evaporated  to  drynea*.  The  resldiie,  vben 
extracted  irllh  hIiiioIii[«  alctiliol.  yields  urea.  Fri>ni  urine,  either  by  eTajMiniliiiK 
to  drynm,  buvini;  prcrinunlr  pr<<ripiuted  thp  urlni-  wiLli  nncmal  aixl  bwir  lead 
acetate  in  ■uccnuion  ami  removed  the  lend  by  lulphurcllvd  hydrogen,  and  then 
exiractiDf  with  aleoliiii;  or  wocenlralin);  only  i«  a  ayran,  and  then  fortnine  the 
nltr«le  oi  urea;  lbi«  ia  wwhed  with  fiuri  nitric  acid  ana  decompoMNl  witli  Miio 
carbonate. 

Iletection  in  tolDtiooa  In  addition  to  the  m[cr<k«i-opic  apnearaDce  of  Ihe 
rry^laU  i>V>tiiiiirit  on  (-v:ipurati»n.  tlie  nitrate  and  oxahitr  *hi>uln  be  formed  and 
cxumlued.  .Vnolbci  piirt  nhnuld  girr  a  precipitate  with  nirrcurie  nitrate,  iu  ibe 
abivnce  u(  vlic  chloride,  but  not  in  tlie  prMen«e  of  this  luKt  unit  iu  exceu.  A 
ibini  portidu  is  treateil  irllh  nilrir  add  containing  iiitniu*  nimc;  if  nrea  la 
present,  nllmgen  and  carlmnic  nnhydride  will  be  obtained.  To  a  fourth  part 
niuifi  acid  in  exceM  and  u  link-  mercury  are  adiled,  and  the  iniitute  li  wnrmed. 

'  Oil,  (II. 

•  Miseiilw.  rHnctf  I  AralilT.  M.  xU.  (MTCk.  %■  311.   Ail»cl>.  JMMeh.  t.  pbrMol-  rim*..  Sd.  T.  (tan). 


J 


IMA 


APPKNtllX. 


la  prtMOfVof  nr«a  «  niAjricM  mixture  of  ^Ror*  (N  *i>d  iX>,>  ia  ^t«ii  «£    A 4 
pnnion  bWpi  in«}t«d  forMutne  time,  dimolT«<l  in  WHicr.  nml  ctipric  Milphaicud 
<aiutie  tods  aiv  »diit4 :  ■  n^  or  vitilct  color,  ilui*  to  bitirel,  it  ilervlopM. 

Asantitative  detarminfttioti.    For  iliis  codic  Hicdsl  mann*!  mihc  U  ohi- 
•nlted.'    U  nill  aitlBcelMT*  to  point  out  tliat  tli«  detaniiinitioD  k  ta*A»  aiifeir 
with  a  Milittion  of  mercuric  nitralv  nf  konwn  ilrrnxlli  lLi«bi|() ;  bjr  i 
ibe  aiVB  by  meana  of  «odi«  hv|iobroai)i«  into  niimjteo.  tuubouic  anbvd 
waiM^.  anil  mcaauriiigilio  oilrocen  (Knop)  [N,H,00 -r  SNaBK>  =  3NHBr- 
■f  211,0  4  N,J.  or  by  lifaUng  uto  un-a  wilh  cauUlc  baryta  in  a  nealvil  lul 
urM  Ming  deicnninn)  by  ibi>  ircj^ht  of  biiric  carbonate  fonurd  I  Itun*««  |. 

Urea  in  g«ii«rally  coimiiliMFil  tri  bo  bd  nraklc  of  carbonic  aciil,  >.  r..  autaaaUt 
Tbt  aaiul«  nf  an  add  b  formed  vrbcn  wuivr  U  r«mor«d  from  tbe  ammuniuai  nti 
nf  ibo  acid ;  if  the  aud  be  dibaalc  and  two  uiolecalea  of  watrr  be  rnBorvi].  ibt 
MBit  k  often  trpokon  of  hi  n  dJamlde.  Tbm  if  from  ammnaic  carbiwata  (NH,', 
OOhtwo  molcculn  '<(  water,  il),U,  be  remored,  cirbooio  acid  bvioj  a  dihMc 
acH,  the  result  U  uroa ;  than : 

(SH,),(X).-2H,0-(irH,>,C0, 

vUeli  uaf  be  wrjtteo  dtlier  aooording  to  tlw  anirooaia  ty|ie  aa 

COl 


COl 


Br  a» 


^{su'. 


iw<>  atouk  <»f  amidoceti  (NH.)  being  Mib«tiloled  fur  two  atooM  of  bydmnl 
(HOI. 

TbU  connection   betwron  carbonic  ncid   and  iirrs  ti  sboirti   by  thit  fad  dul 
ammonic  I'aiboaalc  maybe  tbrmed  out  of  urra  by  hydration,  a*  when  tim  a 
aubjMlcd  ii>  ilip  ipeciGc  ferment  mentioned  abuie.     Re^'Ied.  ttien.  a>  a  diuddi 
of  carbonic  acid,  urea  may  be  itpokea  of  a>  carbamide.    Hut  ibc  tlio.n-tlral  dnf 
■ralioa  nf  itrca  I'luru  uinmunic  carlmoate  by  debvdratioa  cannot  he  mllael  n 
imciii-e,   kberciu  urra  can  rmdily  be  foTtncd   iVniu   ammooic  rarl>aniaie,  aad, 
Ktillie  )>■  iuclined  to  recard  it,  ncfl  as  Ibc  diuiuidc  of  carhiinic  acid,  but  IfllHH 
aHiid*  <>r  carhuuic  acid.     Ammooium   cnrtiikmutc.  <-'0,Njtl,  Mtmn   ll,4t.^^^^| 
urea.  t-X>,  >',,  H^ — wblcli.  if  carbamic  iieid  be  written  tu  tXt.  <)H.  NH,.  m^^^H 
wrlllan  aa  CO,  NH,.  NH,.  'rw  alom  of  Hinid-ijEen  bciuj^  fiibatituleil  fur  onr  atmH 
„f  1..  ,i,,,...i    ,m,i  not  two.  iia  vhra  lh«  uiWtaaca  is  rrgardrd  an  derived   tttAu  at-  ^ 
b-.  t>r«-biier:>  exjicritiiciits   indloote  a  ready  dcrivaliim    uf  urrn  fm» 

■uiL.  ....  _j.rtMaiale.  lie  liai  obtained  urea  by  the  elecir>ily>iii  of  aaulutiou  -i 
tbu  lalt  with  rapidly  alturiuling  current*,  Ibiia  removine  tbe  eletnenta  '-f  «aur 
frum  tiM  oaibamate  by  auch  alternating  nrocemea  of  oxidation  and  retlactirm  n 
may  be  tuppuetd  tn  take  place  in  the  body.    Tbe  mution  i«  expreaaed  aa  M- 


I.   XHct>oxn.-(.o-iNir,.<'ouKU,— u,o. 

2     Sil.COONU,  ,  H,=  NII,CO-NH,^  H,U. 

ft'aaklya'  aod  Gamgte.*  bowofpr,  Hnee  urea,  wbco  heated  viih  a  laije  exoM 
of  wnaiir  iierwiuiKaDMte,  ^ive*  nd'  all  it*  nilroKen  in  a  fttv  >tntr.  ux]  not  In  lb* 
'al'Ii'*-)  f-Mm  of  niiric  ncid.  iw  do  all  oilier  nmideo,  conclude  that  it  b  ool  an 
■f  that  it  ■■  isomeric  only  and  not  Identical  with  carbunide. 

'  itaui  to  remember  tiiat  urea  i»  also  laomeric  with  ammooto  qyanait, 

.  „    and  indeed  iraa  llrM  formed  ariiAcUlly  fay  Wfifalei  (18X8)  tivn 

..'  three  tMmefic  eompnuodi'.  auimonium     

'Mill  other  in  »ach  a  way  that  urea  may  i 
-■ii<>(  ii<>*."  .>j"tii' 'Ilium  cyanate or  from  ammonie  carbamate,  mxi  mar  nui.  luij 

...,,,     .^,   AiwlTw<)all»mKtULaat.TO.&»l 
.    nil.  il.  p.  'A 


4 


CnSVTCAL   BASIS   OT  TRB    A:flVAT.   HOliT, 

eaae  be  converted  Into  unmonic  corlioiiiii^.*  Now  aren  in  n  much  moro 
■bU  body  than  ■oimonic  L-]ranat«.  mod  In  tin.'  Imittrortiiftiluii  of  the  Utter  Iniu 
tbr  foTmrr  tnrrgj  is  aot  free :  and  it  u  northy  o(  iioiice  ilint,  ihongli  tht  ]>TewDc« 
of  BUl|ib('cvimi<i(a  in  tbe  mlivm  prntmlily  indlcatM  llii-  cxi'tnnce  of  cyanic  rr«iduot 
In  Ibe  body,  tlie  Dlirocenouii  product*  of  tiio  ilccom|jnaiiiDn  of  pmUad*  bdong 
ehirflj  to  Ibe  cIbm  of  amides,  cyanogeii  eonipuundH  beinfr  rare  among  tfaem. 
Pflfl^r*  lis*  railed  attention  M  the  ereat  molfcalar  eoNgy  of  lb*  CTmnogeo  Mm- 
ftMnit.  and  liiu  :>u|c^e>tp>H  that  th«  ninctioiul  mMaboliran  of  jirotopuaiB  07  wblch 
eiMCgy  in  Mtl  Ctce  luity  be  cumpared  to  tbe  converaion  of  tbe  eooTROttc  nostabl* 
(gruiegen  conipouudH  into  the  lew  enemtta  and  mure  liable  amidea.  In  olber 
worda,  ammonium  cyauato  Is  a  type  of  livuif ,  and  urea  of  dead  nltroeeD,  and  tbe 
QOnT«nnoci  of  the  former  into  the  latter  i»  an  imago  of  the  esacnltal  cbange  whicJi 
talm  place  when  a  liring  protrid  di«a. 

fW/tmut  Hnoi.  The  hydtngca  aloni  of  urea  imb  tv  replaMil  by  alMihoI  and  aelil  ndlelai. 
Tharaulu  ar»  AjRipaiiurl  <ir*Bii  orunlitno  when  Ih*  hyilruc««  it  n<|ilBaH  bv  an  icid  rulicja. 
Many  if  them  tta  mltcil  nirldt.  liurf  ihn  liy^lniflpti  tit-m  ibc  amide  gnnp,  if  »m  all  r*plaMd 
a*  ■bat*,  (mil  br  r*|ilar«l  by  mdal.  Tliu),  tlie  futntitutioii  of  oxalyl  (oxalit  aciili  ^vai 
IKintHOfe  add, 

fCO 
y,\  H.  nrC«,  Nil^S.CAs 

at  iiMtntjl  ilanroDle  acid),  dial  uric  arid,  rx).  Xlli,  XAIIiOii  of  maaoxalyl  imwoaatle 
Miidl.allman,  Ct).  K)I^X.<',f<r  TKmp  boliea  arc  iDltratlBg  a*  l«ing  aUsotrlaiaad  liytlM 
anitcial  oaldalKiii  of  uric  acwl.    (f««  Wleir.) 

XSt\o  add     C.H.N.U,, 

Tbe  chi«f  cooatilueoc  of  the  urine  ia  birda  and  re|rtl1ca;  tt  occur*  ouly  apar* 
iacly  in  ihia  excretion  in  man  and  mo«t  mammalia.  It  ia  normally  oreaeBt  in  ifae 
■plMD.  and  traces  of  it  have  bran  found  in  (he  tungti.  mivcin  of  the  heart,  paii- 
cnaa,  brain,  arid  liver,  ('ritiury  and  iriinl  calrull  iil\en  cotuiat  iarirely  at  Ihia 
body  or  ila  aiill*.  In  K""'-  lu-cuinululiona  of  urir  acid  Mlta  may  occur  in  ratinna 
parta  nf  the  body,  forming  the  «o-cnJIed  goulv  coucrctiima. 

It  is  when  pure  n  colorlcM,  (Tryalalliiie  powder,  laateleu.  and  without  odor  The 
cfTaUlline  form  U  very  variable,  hut  UKUally  tends  tnnard  that  of  rhombic  lablua.* 
Wbeo  impiure  it  cryalnlli/m  readily,  but  then  ]iiiwmura  ayellnwiah  or  brovni»b 
eolor.  In  water  it  ia  very  inaolubl'e  (1  in  H,OOU  or  15.000  of  cold  water);  ctlier 
and  alcdiol  do  not  diaaolve  it  apfwechtbly.  On  tbe  other  hand,  aulpburic  acid 
lakes  ii  np  wiihoot  ilecomfiosllioa,  and  li  ta  alito  readily  soluble  in  many  aalla  ot 
the  allcalits,  is  in  the  nikatics  Ihenuclvea.  AmnoDia,  however,  scaiMly  dtmolves  It. 

84IU  of  uric  tcid.  of  Ibew  the  moat  ImporUnt  are  the  add  iiisiea  of  sodium, 
potaNiium.  and  aniiiionium,  Tbe  sodium  salt  crT*>alIiz«ii  in  nanj  diStfoot  forms. 
tbwe  aot  bciiiK  chatai'icrlKtic,  aince  tbey  are  alm<at  the  same  (br  Ibe  corroapoad- 
iDt  «>miMMiD(b  of  ibe  other  two  baac*.  It  i>  veir  Inaoluble  ia  c«ld  water  (I  in 
lloOor  1300),  moreaulubte  in  hot  i|  in  VJA).  It  it  ibe  princlp>al  coosUluent  of 
MTeiml  forms  of  orinary  scdimrni.  and  compoMa  a  lurj^r  paii  of  many  calculi ; 
the  eicremont  ofanakea  contain*  It  largely.  The  potnaaium  rracmblD*  the  awlium 
aalt  verv  cliwely.  a*  ahM>  doea  the  compound  with  ammimlum;  tbe  latter  occura 
generally  In  the  ardltnenl  IVoni  alkaline  urine. 

PrmiratuM.  Caually  from  guano  or  snahe'a  excrement.  From  guano  by  boll- 
log  vltb  caustic  i>n|a«h  <1  part  alkali  to  W  of  water)  aa  long  as  ammonia  ta 
vrolTed.  In  the  fillnilc  a  precipitate  of  acid  urate  of  potamium  ia  formed  by 
pataing  a  curmii  of  carbonic  unbrdride ;  tbia  aalt  i*  then  wathed.  diwolvcd  in  a 
eaiHlIc  pdiaib.  and  decomiicned  by  carefully  pouring  its  lululion  Into  an  eiceaa 
of  hydiochloiic  acid. 

■  Tta  iDllniriM  IllcntniK  ti  iMCRattoa  ta  CMinertlan  *lin  l>»  quealtua  at  \tit  eyaaXt  a*  aaMi 

~  ID  dC  una— lirMhul  ^  Bh.  li.  k.  t.tinall  d.  WliK'LflMs- Hlf    "'   '"''   <-^'      >•■''  '  •^i"'«t.. 
LflUA     «.  KalwfaiD    Zt.f  Rk-l.  KI  i.il*;i'.R»X   Mimk    7i 
_.  J    K  Mlkotnkl:  Oiuniur.d.  Mfl  HI*..  in>.  N.>.  W;   |(«> 

R  IM    )WUch  r  fftvlfj   <i^in..  IVI.  I.  llfTI),  *t  1.  U.JJ);  UJ.  Iv. ;..  .-  ...  .•_   ,-.  l.i.—  .l*- 

Urv    kk*..  I  .■\y  i'ti'.'].ibt  ttii   a*ni.g,i. 

1  l'll*i[iT'"  Ar.-1-jv,  11.1   1     [-l.'ii.  *.  MI. 

•  8(aLuaw:>ii«ii^  K.  Ii  UaAnuiDiAllaadirllaniardlaente.  WIen,  Ua 


1048 


APPENDIX. 


Tbe  pratcoeeof  uric  acid  Ik  raconiied  by  iho  Tollawlng  tmU:  Th*  m 
haviiW  bMn  oximiDwl  niiemieapiflMljr.  »  portion  u  arnpgrdlvil  mrrt'uttf  tu 
Don  with  Mie  or  iwn  <ln>pa  of  nitric  Mid.  Tlte  rcsidaewtll.  \(  atie  add  U  firMvni. 
l>e  nf  ■  red  euhr.  ir|iii-ti  on  (ti«  addition  of  uhhobU  tunu  tu  ourolt?.  Thai  li  ih« 
muivxi'le  Imi.  itiid  cje|ieii<U  on  lh«  prMBBW  of  slloian  and  nllnxantln  (»  thi 
residue,  ^'nllilf '  ha*  EJven  ■  dolical*  rttwtion  Tnr  utic  acid.  Tti<^  •uhttuK*  b 
diaMlvcxI  in  itodio  carbonate  and  dfi^pcd  tin  |>*pcT  moiilonod  «ii)i  ■  aiUrr  mIl 
If  urie  acid  be  proanl  a  brown  >uiu  ii  fririuc').  4fu«  to  tlio  rndiiL'tinn  >*{  \\\r  ci^ 
bonoM  or  silrer.  An  alkaline  Motntlon  it  urii-  acid  can,  like  dext/nw,  r*diM* 
ciipric  KUlphAlo,  willt  |i(«cipitaliua  of  ilic  caprniia  oside. 

Uric  acid  naiais  vorv  la^ly  lb«  action  or  on>a  »tinn%  acida  and  alkitlln,  >i> 
lillnttng  iu  lliii  rwl  a  innrki^  diflemictf  from  am.  It  mii^t  ibrrcforr  pi-rhi)* 
be  su[ipo4ud  tliai  urea  residues  do  not  jirKsiit  in  urio  acad ;  o«verttaeleM  bjr  90- 
dation  uric  acid  doss  five  nsa  not  only  t->  ordinary  utm,  but  alsu.  and  al  Ih* 
same  limn,  to  the  compound  urcM  (iir«idM)  Bpnken  ofabove.  Thus,  by  oxldMigB 
irlth  acid*. 

nrl«  acid.  AtlMCSD.  Vraa. 

CjH.N.o,  1.  a,o  t-  o — OtS,u,o,  +  cs,n.o. 

Now  alloxan,  at  waa  atatod  abr>v«,  ii  n  Rnmpoiin')  um.  vti..  mmosalyl-vns, 
and  by  hydration  can  b«  ooavertcd  intu  aivsoxalic  acid  nnd  urea,  thua: 

Alloxan.  Afa^intiR.      rros. 

and  by  tlie  aciloo  of  chlorine  uric  acid  can  be  Hpllt  U|i  dir«oUy  into  a  moleculsif 
nwsozalic  add  and  two  mi»It«ulos  of  aroa : 


i 


Uric  uid.  Mtaeialip  sciH.      UrM. 

UiH.N.O,  +  0',  +  <B,0  —  C,H,0»  +  XCN,ll,OC  +  'JUCI. 


i 


By  uxidation  with  alkalien,  nric  acid  is  0(Hivert«d  into  allantoin  and  caiboab 
add,    ' 

Oric  adit.  AllsnloiD. 

C,H,K,0,  +  H,0  +  O -  t.li.N.U,  -f  CO. ; 

and  ntluntuiii,  by  bydnttiun.  beuomes  allanturic  or  lanlanuric  acid  nnd  nrw, 

AlUbtoln.  UrM.      Allantiirlo  and. 

c,ii,N.u.  + 11,0 =cn,N,o  4.  c.u.x.o. 

Now  allsalurlc  acid  \*  a  compound  area,  with  a  residue  or  glyox^lle  add.  Rr 
Other  oxidations  of  uric  acid,  imr.ibanic  ndd  (oxulyl-uroa).  osalnric  acid  (wbitft 
is  bydraled  parabanic  add),  sud  diuturic  ndd  (tartronvl-urcsil  arc  oliiuinrd.  It 
fiui,  all  tfaeac  dccorapoalliomi  of  a  m'>tecute  ni  uric  adtl  lead  to  ibe  i>r<idiii-t)nt»  tt 
ur«a  und  of  a  carbon  aoUf  of  aom«  kind  or  other.  The  reluiion  <>/  uric  acid  u 
ureL  as  illustmted  by  Ibe  above  rt>Hclioit>i,  is  brought  very  pmoiinenily  into  nr« 
by  tbe  arnlheds  of  urir  uoid  which  hiu'  r<-ooRtl^  boon  fvtUtftarA,'  It  ts  obtalnei 
by  nmplyltMing  loKclhrr  £lyci)i:iiiv(auiido-aoeiio  acid)  and  urea  at  n  t<>iBp«nt»» 
or  S00^-33iy  C  The  converse  fonnutioo  ol'  glycocine  from  uric  ut-id  nitb  iW 
•t  mill  taneoas  prod  notion  of  amntoiiis  and  carbonic  anhydride  ha»  lieeii  k.n'>wD  far 
aoma  time.  Since  in  this  Iatl4>r  reaction  th*  nRnnooU  and  <-jirbonic  anbydn^ 
are  in  the  proporlion*  in  which  they  would  be  obtained  fr-im  ryanii-  or  ryanarir 
add.  uric  ndd  bn«  been  rennJed  >■  Ixiilt  u|)  fri>m  midui-n  of  cyaniiric  acid  and 
lllycin,  iuHi  aa  bippnric  a«id  In  furmed  from  Klycin  and  bciir'iic  add.  It  wa*  ak» 
u'one  time  snppoaed  that  urie  acid  might  Im  regardod  as  urironyl  cynnamidt. 


If  the  osidi'oce  of  some  cyanogen  residue  is  thna  ansumod  in  tlt«  raolMola  1 
urie  add.  then  it  must  be  euppotwd  that  before  urea  can  be  obtained  from  it  > 

Ann.  d.  Cbi-m  11.  rhaxB..  M.  e»  :^  SI 
*  UnttaniMkl,  Sa  >l   tloMiili.  CbaN.OtMilU  Jahrg  1>«1.S.  sn«. 


I 


I 


I 


•  SMV.KnleilM.X*M>*fe.r  BM.M.RlH.(l«7).a.«l   fthiMtr.  MiMfc.  C  ttr^lL 

>  i*hib.  ln,um.  VM.  M  Xilll  i*  41. 

•  OUMiplxr.  a.  IM}>rtMk.  At»a.  I*CK  llnft  ■.  Sl  m. 


M. 


nnlncutiir  rlikO|ti>  iitkr*  |>Uct  by  which  ■  iMrtiati  at  Unuil  nf  thp  niunx^i  ■■'  tlic 
uric  BL-iil  u  oinvciicJ  into  the  Mtn«  cundilion  u  lfa«  rod  of  the  nltmgen.  vli., 
iiitrj  ih«  anld«  state. 

If  ibu  b«  M,  aiiiM  the  mi^tabnlMiD  nr  the  animal*  in  which  iiric  B«id  rci>lacM 
urm  cinnot  bir  au|i|><a((l  In  W  ftindiunciiUlly  dilTrredl  from  dial  v(  tin-  urt*- 
nmdacinf  aninub,  wi-  muy  iafet  that  Ibe  iiiiUi-i'ileiit  nl  Uilti  uric  iicid  anil  urtra 
In  lh«  regrtaalve  ntetulHiliuii  uf  (inii«ldii  U,  its  we  Auggvalv'l  uImtc,  a  \>oAj  c«ttt»iii- 
ing  Maw  at  lout  of  ita  tiiirug«n  in  thci  form  af  c^anogcii.' 

KreaOB.    C,ll,N,Or 

Occura  aa  a  cnnslant  cnatilituant  of  tho  jaicm  or  mnncte',  llioogh  poMlbly  It 
may  be  foniiAd  during  the  procoM  of  rxtmcti'm  by  the  hydration  of  noatinin. 
KraaUti  >•  not  a  normal  conalituont  of  urine,  but  it  ii  uiiil  lu  uccnr  in  trnco  in 
Mt«ral  flulib  of  the  liody.  Wh«ii  found  iu  iirine  ii> j>ra>eac«  1*  pmbablj  ilue  to 
tbi-  conrenloa  of  krcatlnln.  a  coitsuim  ciioMtitui-nl  of  uiiop.  Inio  Icrpattn  during 
il*  (■xlriwlinn.  »inco  Dcvwaijinw'  lia*  ihnwn  that  llio  mar*  layniUy  thr  uppamtion 
in  rlTrL-tnl.  lb«  Irwi  in  thv  iiuanlity  uf  krnatin  nbtainvd,  and  Ibc  gruil«r  tlio  naiount 
uf  krratinin. 

In  thi'  anhydrouH  form  it  is  wbito  and  i>pa(iiic,  but  cryitallizca  with  one  mole- 
rale  of  water  in  coIorteM,  trantpar^nl  rhombic  |'ri»m>.  It  pnweaMB  a  antncwlial 
bitter  taiiie,  in  solubk  in  cnlil.  exlrcmrly  onlnlilp  in  hut  wuler,  ia  lesa  (ohiblc  in 
abuiluic  than  in  diliitr  ak^ibol,  and  in  Nnlublr  in  rlhcr. 

It  is  a  wij  Wfuk  boiif?,  tcnrcvW  noutnilixlug  tin-  wenkenl  aoida.  It  forms  vryn- 
lalline  compound*  with  Bulpburfit,  hydrochloric,  and  nitric  acid». 

flftpamtion.  From  eatraci  nf  maaclo  by  ]>rccipiCotinK  rompletcly  with  baric 
lead  M-etntc,  and  cryHt.illiEinR  nut  the  krentin,  mixed  wilh  krcntinin.  Fmm  thia 
latier  it  it  lepiirnird  br  the  formation  of  the  xinc-aalt  of  kreatinin.  krcatin  not 
readily  yielding  a  nimilar  com]>oUDd. 

Knaliu  DMy  be  eanTonad  Into  kraaliala  uuiUr  the  lalluonco  of  udiU,  iha  ifBuifbriaialiM 
beiu|C  oiie  of  naiplu  •tvliyilnliun, 

Kreatiii  may  be  decompuaed  iotu  vtrcoain  (niethyl-glydn)  and  tirea: 

C,H,N,0,-  H,0=  U,H,NO,TCn,S,0; 

il  nay  be  formed  iiyntheliailiy*  by  the  acliao  of  aar«otiln  and  oyanamUIe : 

CH,XU,tCD.N,=C.U,N,0. 

San^n  [aBlydnin  wlilchoneatoinorbydrngen  haabce«i  replaced  by  lb*  akolMtl 
radirlo  mMhyl,  tbui>: 

Cllyei- 5?g."  }  O  beeow- ^.«4';.'*  }  0  i 
ltk«  f  lycio,  (areonin  ha*  nut  been  found  in  free  etate  in  llie  boAj. 

KiwAtinin.    L',H,N,U. 

TbU,  vfliicb  i*  aSmply  a  ilchydratcd  form  of  kreatla.  nccura  Bormally  a»  a 
•tant  cdOMltuent  of  urine  and  of  tnuwic  extract.     It  cryatidllren  In  color] 
•bintng  prtMnf.  poMtenaitig  a  alrong  alkaline  taele  and  rcat'tion.     It  U  rei  ' 
aolublein  culd  water  (1  in  11.*').  nlpwj  in  alcohal,  but  i>  icanvV  ■nlublo  in  ciIiot, 
It  acta  nil  a  iiowerful  baae.  formioK  with  acids  and  mil*  cumpouitd*  vhicli 
cryaialliM*  well      Of  these  the  ii>o«l  important  !■  the  anil  with  sine  chb>rlda 
(C,H-N,0|,Xa  t-l,.     It  \»  f'truied  when  a  concentrated  aolution  of  the  chlorhle  b 
added  !•>  a  not  t<x>  dilute  solnlUm  of  fcrealiuin.    Since  the  coiufixind  in  very  little 
afdnbl*'  in  alcohol  it  U  better  lo  ow-  alcnbolic  rather  than  aipidHK  wilniionn.     Il 
i*ri->tallJMa  in  warty  lump*  comiMMed  of  nfgrc(al«d  niaattai  uf  ptiauia  or  fine 
tieedlcK. 

frqtamiion.    EJtlier  by  the  action  of  iiclda  on  krentln,  or  l>i>m  human  ur^ne  by 


M  "••"■a" 


i 


iMoO  APrE-vDix. 

COnc« Dinting  an i]  precipiUtiDi;  with  lead  kcetit«;  in  the  filtrate  from  thisaMCoad 
prectpititt«  U  caiued  b^  the  adilition  of  mercuric  chloride,  and  consists  of  ■  com- 
pound of  thin  Halt  wiih  kreatinin.  The  mercury  is  removed  by  suiphurestei 
nydroEcn.  anil  the  kresiiuin  pariSed  by  the  format iou  of  the  zinc  salt  and  vssIub^ 
with  skohol. 

Kreiiliijia-ii[i<>  clikiriilr  rnHT  '«  rnnverte-l  inlo  ktvslin,  by  Ihe  Bcti->n  uf  hydnlcd  nxiittl 
]«ail  'm  iti  ^ppiljnif  acjueinin  ^'luticm. 

Allantoin.    C.H.S.Oj. 

The  characiemtic  cnnstitueBt  of  the  allantoic  fluid  of  the  fcBtaa;  it  occuitaho 
in  the  uriae  i>f  animalg  for  a  short  period  after  their  birth.  Traces  of  it  aresoae- 
times  detecu>d  in  tbia  excretion  at  a  later  date. 

It  cryntallizeH  in  »mall,  xhining,  colorlesH  prisms,  which  are  tasteless  and  odor- 
less.  Tliey  ure  soluble  io  l&l  parts  of  cold,  more  soluble  in  hot  water,  insoluble 
in  cold  alcohol  and  ether,  soluble  in  hot  alcohol.  Carbonate«  of  the  alkalies  <^\t- 
solve  them,  and  compounds  may  be  formed  of  allantoin  with  metals  but  not  iritli 
acidfl. 

Allant'iin,  an  already  stated,  p.  1048,  is  one  of  the  products  of  the  oiidilioa  of 
uric  acid,  and  by  further  osidation  gives  rise  to  urea. 

/W/iirii/iiin.  This  is  best  carried  out  by  the  careful  oxidation  of  uric  tai, 
either  by  meiins  of  potassic  permaoganate  or  ferrocyanide,  or  by  plumbic  oiidc 

Hypoxantbln  or  Sarbdn     C,H,S,0. 

Is  a  normal  constituent  of  muscles,  occurring  also  in  the  spleen,  lirer,  tnil 
medulla  of  boneK.  In  leukiemia  It  appears  in  the  blood  and  urine.  Itcijiul- 
li^es  ill  fine  iieedlea  which  are  soluble  in  300  parts  of  cold,  more  soluble  in  hoi 
water,  insoluble  in  alcohol,  soluble  in  acidsand  alkalies.  It  forma  crystalline coii- 
[HiundH  with  acids  and  baaea.  It  is  precipitated  by  basic  acetate  of  lead,  the  [«■ 
ci]>itat<;  being  soluble  in  a  solution  of  the  normal  acetate.  Its  preparation  &aa 
in  use  Ic-f.t  tract  ilepenrls  on  its  precipitation  first  by  basic  acetate  of  lead,  and  lh« 
by  an  iiinnioiiiatiil  no!ution  of  silver  nitrate  after  the  removal  of  kreatin. 

iliilli  hyintxjiiklhit)  HOil  Mie  nc.\t  IhhIv,  vjinlliin.  cnn  al^^  bf  oblainecl  from  proteidf  bv  lit 

HI''! f  |"ilr.TJi''liv.>  cliiiiiKei'.  "f  "•mIit  «t  lnjiliiic  luiiijwralurp.  of  dilute   !iydrufhliiriiri>il 

III.:;  [-ir  1  .■lit.)  lit  l() '  I'.,  mill  liy  {\ii-  atlioii  of  Ruslric  Biiil  fiHUc-reatio  fermeiiU.'  Ciiiueiniti 
tj»?i  Miilirril  ;i  if'-iiUiiv  difW-ri-Uf-  lk'IW4-*>ii  tiliriii  Hiid  e^e-<ilbiiiiiin  vrhen  3i>bmjtted  [<*  tboEi^^^ 
]iriH>^K.H>ri :  III.  fiiiil.4  i}ijii  ilif^  liitler  d^>r^  iii>t  vifM  iiy]*iixanItLiii  when  tnrat^l  witb  boilsEC 
K-iilcr,  11-11  h  ililiiiii  Ly.lripi'lil.iri.-  iii^id.  nr  I'ni'lrii-  tVrrneiil,  irliile  lhi>  former  does.  Ei!g-ilbum:o 
nil  till'  I  it  1 1',  r  fill  III  I  yi,iM:>  liyjHiXLDilhiii  by  tlio  ■I'lion  uf  ]>Biirrealic  furment  in  alki^liuriwluUi'o 
biiT  inil  ,.-.1  midili'  ji?!  liliriii  liin-s. 

Xanthin.     CiH.N,",. 

Firnt  liiHi'overt'd  in  n  nrinarv  I'alciilus,  and  called  xnnthic  oxide.  More  recentl.r 
it  hn.1  lit'i'n  f'liunil  as  n  normal,  though  scanty,  constituent  of  uHoe,  muscia,  wt 
sevnnil  orpln^<,  hiicIi  as  the  liver,  spleen,  thymus,  etc. 

Wli<-n  prci'ipitaliil  by  ('<'<>lin);  from  its  hot.  saturated,  aqueous  solution  it  Ub 
in  ivliiti'  llocks.  but  if  the  solution  be  allowed  to  evaporate  slowly  it  is  obtained  in 
:<mal)  soili'H.  When  pure  it  i:t  a  colorless  powder,  very  insoluble  in  water,  m]ii>i- 
in^;  iriOi)  time:*  ibi  hulk  for  solution  at  IW  V.  Insoluble  in  alcohol  and  etfaer,  n 
readily  ili^solves  in  ililulo  aciil:<  and  alkalies,  forming  crystal lizable  compoan<b. 

ny]io\:intliin  liy  oxidation  becomes  xanthin.  ISoth  these  bodies,  as  well  uii' 
foUiiwint;,  (luiiniii  :inil  c;irnin,  arc  evidently  closely  allied  to  uric  acid  ;  indwi 
uric  avid  hv  ilic  :u'li'in  of  :<oiliuin-am^ilgani  may  be  converted  into  a  mlitiiKi''^ 
x.iiilhiii  ;iiiil  liy|iii\;iiilhiii. 

/'•••l-i-'iliiiii,  h  is  obiaiiicd  fr^im  urine  and  the  aqueous  eitract  of  muscle  b.f 
prMci':i.->  siniihir  tn  tli:i1  for  hypoxaiithiu,  and  is  then  separated  from  the  l«11«r  br 
ilio  iu-li'Hi  i<(  dilute  hyilruchliiric  acid  ;  this  separation  depends  on  thedifl*r»i 
Kohibili til's  of  Ihc  liyiirocblorlili's  of  the  tn*o  bodies.  For  further  infonnalioBiM 
Ni'Uli:ilii'r  ami  Vo>;i4.-' 

7'*-l''7"  .  S.  >'>•}.     Kthvm!.  Ituu£.  liisft.  Iferiiitl"^ 
KifSM.-!.  /^'U-oh.  f.  ptiy^i^«L  v'bi'm  .  BtL.  v.  .IW".      | 
:  ll.i;:i  .Vn.i  >-^-  IM   i  -i.     I—'.    -  -■■■.     .V^Hi  iln-  liiitaiiirv  .|Ui>le>]  aleveun  hjrpoxuuUa. 


'  J  , 

..'      'I-    ,'. 

■-,-h:    ■■  1 

'>  ~ 

llVlil 

"1 

li 

•  h:::- 

.-I     '1.  -'.   '! 

r,    .■!  Il;i 

Si 

11    }-: 

'  ^ 

1'-' 

.liilirj 

\';^      1" 

-  .1 

.-...1 

1.  Mill). 

s 

nil 

I 


CHBHICAt.    HAfllS   or   TIIK    AMUAI.    BOUT.  lOAI 

OUBlB.    C,H.N,Or 

DisooTfred  by  Wei4«l'  In  exinci  of  niMt.  or  whidi  ft  oiaiiilutM  nbuut  on« 
pereeot. 

It  ciyntnllizM  in  t«hil«  miiwoi  crnnpoMd  or  very  sirtall.  irregular  cry«M]» ;  il  ia 
■olgUc  wllh  dilEcuhj  in  cold,  mnro  ciuily  Milublc  in  tint  nalrr,  iDMiluhli-  in  nloci- 
hol  and  Gtti«r.  lu  ai)uvoun  Holutiim  in  not  |>rvcii>i[iiitMl  liv  nonniil  Irail  novtate, 
iMit  ia  b^  tbe  baaic  acetate  of  tlijg  metal.  It  unltM  with  adda  and  mIM  forming 
cijatallin*  coHipoanHii. 

jyeporatwti.  In  found  In  the  prrripitttp  cnuard  in  Mlract  <if  laeal  by  baalo 
acetate  of  l«d.* 

Tlii<  liol;  psaiNH*  sn  iatara>liii(r*Uiluii  tf>  liTi-maiitliin,  inlo  whioli  II  iiMjr  W<DnvDrtal 
by  til*  Mfioa  eilbar  of  nilrii'  beuI  or.  fltll  boitnr.  V>f  lircFiiiii*. 

Ouanio.    (^tItK,n. 

Fintot>tn!n4Hlfrrimgunno.  but  recentljrobserredaaocourrlngin  atnall  ituntiliM 
in  tb«  pancTPiiH,  livrr.  and  muoclo  pxtrncl. 

Illaa  wfali«aniorpliou*  nowdvr,  iiuoliibl*  in  water,  alcohol,  other,  asd  ammonU. 
It  vnittt*  nilfa  acldo,  slkahen,  and  anlta  tu  Tonn  cryalalliubtc  conpouuda. 

Prfpamlion,  From  giiiuio  by  boiling  MicceMlvely  with  milk  nf  llm»  and  caoalic 
•oda.  i>redpituiliig  wttb  acetic  acid,  and  puriiying  by  lolutinn  in  hydrocblwk 
acid  and  firecipitntion  by  ammonin. 

Goanin  mav,  by  tbe  anion  nf  nitmua  a«id,  be  coorcrtnl  into  xauttiln.  By  oxi- 
dation i(  can  be  made  to  rield  iiHuciimlly  guonidlne  and  parabanlc  acid,  accom- 
panied, IiiiwcTtir.  by  »inaU<tuaiilitir*  ofureift.  xaiiihln,  and  oxalic  acid.  Ca|innics 
Ua4  giv«a  oevrml  rratiion*  chanirteriRtic  "f  thin  body.* 

Ita  sefiaration  frum  liypmiuiibin  mid  xanthin  drpcniU  im  it*  inauluUlitj  In 
water  and  behavior  with  liydiocbloric  uuid. 

Kynurenlc  aold.    f,TI„N,0,+  SH,t>. 

Found  In  ihi?  urine  of  dogD.  and  Orat  deaoribed  br  Lleblg.*  Wlien  pure  il  ^^*- 
talliT««  in  brilliant  irbite  needle*.  IniolubJe  lu  cola,  HtubTe  In  bot  alcidiol.  Tbp 
only  Mit  or  thin  body  nhirh  cry»lnltiies  welt  la  that  formed  with  barium.  For 
preparation  and  oibcr  parti ciil an  xr  Liobig.*SchtiltXMi,  and  Sebmiedcberg.' 

Olyoin.     C,U,(NH,|O(0H).     Attn  oikd  Hlyooedl  and  Glycocioe. 

Dow  not  nccur  iu  a  Tree  ulate  in  the  human  Imly,  but  ontera  into  the  eoBlpad* 
tloR  of  many  important  aubttaneo,  t.  a  .  hippuric  and  bile  iidds.  It  crystalliM 
large,  colorlea*.  hard  rboinbohedra,  wblcli  are  ea^itv  soluble  in  water,  inaolnbla  in 
cold,  ■liKhlly  aoluble  in  hot  alcohol,  iaeoluble  in  etlier.    Il  po-wcow  an  acid  reac- 

ttion,  but  a  ««r«t  tutte.  It  baa  aUo  the  pmpertr  of  uniting  wilb  both  acida  and 
baaea,  to  form  crystal t i «ib le oompouodii.  lu  thii'il  eshibita  ita  amide  nature,  and 
that  It  b  an  amide  Ih  rendered  evident  frwin  the  meihoda  of  Ita  Byntbetlc  vrepam- 
tton:  tboR  oiono-chlar  accllcacid  and  ammonia  giveglycin  and  amnontuctiloride: 

^dn,CI  0^  -^  3Nn,  =  C,II,(Xn,lO(0II)    -  NH.CI.     it  »  amido^cedc  add. 
Healed  with  caiucic  biir^'ia  it  yieldn  amnionla  and  mothylamine. 
J^rprtratioa.    Pruui  slutiu  by  thr  uclioo  of  acid*  or  alkallte;  from  hippnric  add 
by  decoffl]>jain|c  it  will!  hvdroehloric  at-id  ai  a  iMillug  lempeniUTe  ana  rraWTiBi; 
by  precipitation  the  ftimiiltaneou>ly  formed  bonioic  acid. 

Taurtn,    C^,NO^ 

In  addition  I'l  enterine  into  the  cninp<»ition  of  taurocholic  acid  (•««  p.  IDTifi) 
laurin  i*  found  in  trnim  in  the  juiots  of  muKcle  and  in  the  lunipi. 

It  cnrstalUcua  in  cuIoHmb.  regular  ■ii-aided  pritnu) ;  thete  are  reulily  Miluble  In 
water,  leea  ao  In  alcohol.  Tlie  aolollann  are  neutral.  It  Ida  very  Mable  coinpoand. 
neiaCinc  l«mpenitnrc«  of  lee*  Iban  240*  C. :  il  >•  not  acted  on  by  dilute  alkaliea 
■ad  acta*,  even  whrn  boiled  with  tfaem.    It  ia  nut  prccipilnied  by  melnlliu  lalt*. 

•  Ana. <t.  t-bnn.  u.  phUK,  51  rtviii  ji ais.  ■  ^^  »vii]ci.o(.  tit. 

•  ItHtti.  t  phnlnl.  <lMm..  IM,  tv.  nWDI. «  va 

•  Aaa. 4)  ClMtni  u.  Ptena.. IU  Ixxnl  »i.  ir.. *i>rt  M  n\a.h.*H. 
•0|i,eU.  •  Anr.  ri  n>eui  iL.naflB,  Bd.tUlT.&Ufi. 


\ 


Tuiriti  ii  ■Dida-i<Hlii'>nir  «i:i<j ;  bbiI  tnar  t>e  ■yntlirllmll)-  )>rp()*i«<l  rruni  Urtk» 
onlc  (fllhjrl-aulphurtc)  acid  by  the  ftcUuu  ot  •aiiuoiiia ;  ikus : 


^"•}  so.  +  SH.=  ':;fH|}so,+n,o. 


Prtyata&m.  An  i>  proilitct  nt  tbir  dcooiniiMlUwi  of  bile,  and  h  [KtfiGvd  bj 
ths  mnnr!u)[  iiiiy  iriicm  ul'  bile  aci<J«  by  ninoti  at  lend  aeeUbt,  And  Uihii 
wccwitcIt  cr.VBintlixing  fruui  naCer. 

Loucin.    r.HuNO^ 

la  •mii  (if  the  prindpol  prodaci*  of  ili*  iIci'>>iDpri>iii»n  nl  niiroeenouA  innurr, 
eJlhrrTinilrrtli<<indacnoeor|iatrcfHi;tii>ii  or  ornlruagiwiiUuixl  nllcall<m.  Iiiiccun 
bowevcr.  nonanWy  In  lb«  pnnvrivi,  iplncii,  tliyiniu,  iliyrnld.  nlirarr  ulandji,  li««, 
Mv..  and  in  oDe  or  the  uruduem  of  the  irypiic  (pancrt«tlc)  digoiign  of  pTtAmit; 
iaai.-iiieiilr<-iphyoriheIirer  it  U  preHcnlin  ilieurliui  in  laii{«<|unnt(iy  in  c«aipi>; 
iriib  trriMiii. 

As  liaunUy  oliUiint-d  in  an  impure  A>nn  il  iTyHUUitea  in  n>iii>d«d  lump*.  wUd 
an  often  ootlecied  t'lK^ibtr  and  ■nnietinie^  eihlbii  rudiAlIni;  iitri»(iim.  ^Vka 
purr,  h  (<-irm%  vttf  thin,  white,  slitieriiiz.  [!iit  i-ry^taln.  TlieM  are  eauUr  aolnUi 
;n  Imt  nnti-r,  Iwn  so  in  cold  waler  and  iilcoliol.  iiMotublc  in  «lbw.  Tlief  »«d  tttj 
lu  tile  luucli.  and  iin  wilboiit  *iiiell  and  ta*te.  Acid*  and  alknllea  <ll*sn1ve  ibMi 
readily,  nnd  crjrtallizablc  compuundu  ate  liinncd. 

OaN/Ully  boalMl  to  170°  C.  It  jiiibliiiiM.  bnl  nt  a  hlgbar  l«nporaiure  >■•!■-' 
ing  amyUmiu,  nrbouk  nnby<ln<l«.  and  Kninioiiia.  In  Ihe  prewnof  of  pn. 
BiaUor  >^  tplilii  u|>  inlii  v»lvrir  wiil  aD<l  aBBiniiik. 


..ni) 


I 
I 


4 


Leuein  ia  ainido-caproie  acid,  and  may  be  rejircaented  thin: 


''l^i 


J 


prtpitnidon.  Prnni  horn  «havinp  by  boitinK  witli  nuiphurie  acid,  nvumlldif 
with  uiiryla  and  *<-|>*iatiaK  fti>m  tyroain  by  f<ucei»iirv  vryslalliKitl'in,  See  ab« 
Kilbne,'  nbo  prcpon-s  it  by  ihc  itclion  of  pnnertiatic  furineni  (trv[i«in)  on  pi»- 
teida. 

Scberer  baa  given  tbo  following  tut  for  ieucin.  The  aiiapecled  anbatanct  I* 
evaporated  oarefully  In  dryntw  with  nitric  acid  ;  the  rcaidoe.  if  il  \*  leudn.  will 
)(«  almuat  tnuNparcnt  and  turn  yellow  or  bmwu  uu  ibe  addition  of  cnustlc  aa^L 
If  titix  Iw  Hcaln  rery  carefully  Joncenintied  with  tlie  alkali,  an  oily  drop  ti  ob- 
uiiieol,  whiuo  t«  quile  characteriitlic  nf  thlariiliataiice.  I^eni'in,  if  mrt  uw  tBipuni 
may  be  cwily  reojigniiici  by  tin  Miblimlnjc  on  boiitg  htatcd ;  a  cbaractfriatio  coliff 
of  amrlaniin  in  at  ihe  mmtf  time  evolved. 


I 


m 


Asparagine.    C,ll,N,Uy 

!■  noi  found  m  a  caiinliiaenl  of  the  animal  body,  1>ut  appears  li>  l>e  fomim 
the  d«oani|M«ilfoii  of  proteidit,  notnbly  iliirin|c  Ihe  gornimntive  cliiin|[4«  i>f  tbit 
proteida  In  leguminous  aeeil*.'    It  ia  a  cryalultine  body,  and  mbva  Unled  wild 
aclda  or  alluiUca  ia  rradily  oinveit^  into  lupantc  acid. 

Asportio  <iw  atjiaraginif)  ooid.     C,H,NC, 

Tbu  acid  haa  boen  obtained  in  amnll  qunniitia  among  the  priiHuclB  of  tlie  i, 
creatio  digeation  nf fibrin'  and  vegetable  gtutiii.*  altbouKb  tir.t  mrcarring  at. 
conultueni  of  any  uiiimal  tisaue  or  aovrelion.     It  i*.  on  the  other  hand.  T 
normally  In  plains.  n'>tablv  in  beet-augar  molaue*.     Il  ariaea  also  aa  a  i 
produd  of  tlie  action  of  alkalie*  and  other  reageniii  uu  both  vegetable  and  i 
proteidjs  and  nf  acidn  on   KeUtine.'     Il  thu*   |-MNe«ea  OOTMhlerable   inltr.^  ia 
reapcct  of  il>  relation  to  tbe  protcidH.     Il  eryMtallixoa  in  rhomliic  |>riiiKit  which. 


<  Vln4Kiw'*ATeMT.  IM   mil  fl  IW 
>  UiHlatnbwh.  V'--..  I 

■llmldclendlu.  >^ 

•  V,  Kutfffeui,  2i)ii-.  ... 

•  HorhKaMvU.  Hub.  <).  i.  Akaj  ii,  \'<  \f..  v,  xu,  x^D.  2  JMh.  Jnal  H«<L 


■leralL.  Jalug-  vQ-  imV.  !•  lU* 


» 


»r*  l«H  ■p«rin|[lT  nolgble  in  coM  irniw  or  Rtcobol,  mdWj  idIiiIiIp  in  buillii^ 
»»t*r.  Ita  kciil  •ulutiun*  are  dexlro-mtatory.  iu  alkaline  tn-Tu-niiali>rr  luitl 
rednoe  Fcltliii):'*  Buid.  It  furaw  «  cliaraoUrialU-  rMdilr  i-ryaulliubl«  com- 
pound with  i-u|>[jer.     Nltiuiiit  acid  conrerU  it  iolo  malic  acid, 

Olatamiolo  nold.    C.U^'O,. 

Tbf  circuniiitaiicQ*  and  c»n<litiiinii  under  vbicli  tht*  body  ocnn  are  iii  pneral 
the  ooaie  lu  fuf  ihe  aapariiL-  hcIO.  un<\  lii'ni-e  uh  a  product  of  Dmicid  ileL-omimaiti'in 
It  ocqalroi  Mim«  ini|ion>inc(i.  It  hnn  ii^>t.  Iiowever.  a*  yet  Iteeo  obuined  \iy  th<* 
action  of  poacraatic  fivment*  on  protcidii.  and  iii  thin  it  diflVr*  from  tlie  prM.'«diut,' 
body. 

It  erjilallixra  in  rlinrabic  iGirahedrn  or  octahcdrn ;  l<  nnt  very  aulnbli;  in  coUI. 
bat  re«ditv  tolubic  in  )iotw»i«r:  UiKoluble  In  alfohul  and  eib^r.  In  iK'id  itwlu- 
tloDB  poBBCM  H  Btrong  dexiro-roiatorr  fiower,  and  it  retliiL-M  Pebliiig'a  fluid. 

Orstio.    C,U,NSO,. 

la  the  chief  cttiuitiincnt  i>f  n  rarply  occuTring  urinary  calculus  in  kko  nml  don. 
It  maf  mlao  occur  iu  renal  concreiioiut  and  in  Rravel,  and  in  uccosionully  foand  in 
nrine. 

Frotn  calculi  it  i*  obtained,  by  eximirlion  witb  tiintnonia,  as  colorlHS  ilX'tiidcil 
tabic*  lit  rlionibnlicdm,  which  arr  iiriilr«l  iind  LMlclnw.  It  in  iniKilublo  in  i>at«r, 
alcohol,  and  elhiT.  wiluble  in  ommouia  and  tb«  other  alkniiiw,  nnd  aliw  iii  minenU 
adds.  The  Out  tlmt  tliia  body  la  one  of  Iho  Csir  ajntalliiie  iiubsUni.-ea,  ucvurring 
pbyaiotogii-iillv.  which  contain  mlphnr,  renden  its  deteoiloo  very  «sMy,  Apart 
Rom  lu  inHoliibility  in  wntor,  etc.,  it  yii>ldK  with  cauhUc  p'>tMU  and  talts  of 
either  silver  or  Ind.  a  brawn  culuratioi)  due  to  tbe  proMOCO  of  lli«  sulphidca  of 
tline  nietal*. 

AecoolioKta  Dswacaiiil  iiauitfi*:'  cyiiiii  l>*iiii<l<>-Mil|>ho-tivrurloaad,aiiil  II*  AirmuU  ii 
CilUroOi — pjrnino  boing  Inciic  ueM  aiiaui  mo  sl>>iii*  of  bylroijiiii. 


Tub  Akouatio  (iKKres, 
Bensoto  ncld.    nC.UtU,. 

Thia  t*  i»it  found  iw  a  normal  coiuUturjil  of  the  body,  but  Owm  its  pmenoe  I& 
urine  to  the  fcrmentutive  decompueiilion  uf  blppuric  add,  wtMreby  glydn  Hiid 
benxuio  oi-id  are  furni«d : 

tlippiiric  acii).  Glvrin,       Oouiiila  uid. 

C,H,(C,II,0)SO,  1  H,0  =  C,U,NO,+  C,HjO, 

The  lublinted  acid  ia  generally  cmUilliMd  in  fine  needle*,  which  am  li)rbt  luid 
gliateiiint; :  niiy  odor  they  poMeM  iii  not  dtie  to  the  acid,  hui  to  on  eHenttiil  oil. 
witb  which  llicy  nre  mixed.  ^SHicn  prcdiiitatcd  fWm  solution  the  cryBtallin«i  foTra 
b  always  indiitinct.  Thi>  arid  is  nolubic  in  SOU  patis  cold  or  %''  parts  of  U>iling 
walrr.  but  is  ca*ily  xilublc  in  alcohol  ur  etlier.  It  *ublim«*  readily  s(  IVi"  C. ;  It 
also  puuMC*  off  in  ihc  ra['on  urinin^  fniln  Ibi  heutc^  a'llutiuaii. 

Premmli/m.  Either  as  abuxe  ftftm  liipiiuric  acid  by  femientiuion,  by  boiling 
lite  blppuric  acid  wiih  acids  or  alkalies,  or  bjr  aublimattoii  fruoi  gum-benMln. 

Tyroolit.    CVl„.\u,. 

Q«Dorally  accampiinin  Icucin,  and  ia  perhapa  found  normally  io  small  ^uan- 
tilifs  !o  tlie  pancreas  nnd  apleen.  It  is  also  mually  ublaiocd  in  larxe  qnnntitiiii 
by  tbe  deoooipositlon  of  proteld  tnstlcr,  eiiber  by  puircfoolioa  or  the  outioti  vf 
adds. 

Tbe  rvaaaiDlMaof  Riutiif^awaliy'  rmdar  it  prnhotila  ilial  lyraain  ilaat  ael  ocmr  aonnallv 
in  aay  pod  of  Iha  bnnian  anaaiam,  azetFa  as  a  prodeiS  *t  paaaaalli)  lUitaaUsn. 

All  attempts  to  synthetlse  tjrosin  «et«  for  sofne  lime  fhiitlma,  although  eci- 
denoe  wna  »liiaiii<yl  MilHcieut  to  Indicate  the  probable  exiai«nee  iit  ib  molecule  at 

<  Juiim.  oi  \B»\.  and  pkv«oi..  ytn„  imi  u.  ita. 

>  AiDlilr,  (,  lalli.  Aaal,  bL  suvL  S.  1.    ZdlMb.  t  asol.  Ckav..  BJ.  *.  K.  Mt. 


1054 


APPEXDII. 


some  aiviaMic  (ph«nyl)  radicle.*  More  nvcntlr  (he  •jnlhMb  bM  bne* 
formod.*  «itd  «c  BOW  hBTo  pvery  nwon  Tur  rcguiliiiK  tyni»ii>  u  p«n-fa;ilrat, 
pheiiyl-(i  Kluniite.  This  »i-uth<Miii  u  wiMl  lu  tliai  of  uric'  acid,  referred  Ui  aburt, 
w  of  oonal<I«rftblo  iin|>(iriiiii<.-tf,  since  llie  idotc  defioitc  tlie  linoirledi^  wkich  w 
poAMwed  of  Ibe  true  molocultu'  etrnctiirc  of  tlir  prnducU  of  pti>tri<l  deeoaiiNMi' 
tiMi,  tbe  mora  mwxi  i>  tlior«  Ibr  ripcctini;  Ibut  Uiv  Kynlbmia  of  ■  prouM  fbtU 
may  be  realiiable  in  the  not  Tcrr  raiitMe  luture. 

TTrodn  cryiUllizM  in  exceedfiigly  Ane  n««<llea  wliicb  are  ii<mallr  oollvctwl  Inlt 
fMllicry  DiaiiMs.  Tbr  cry^uls  tire  itnow-whtte.  Uslelmh  Mid  odorlMa,  klnart  io- 
Mluble  in. cold  vttxcr.  ivjulily  notiible  in  liot  water,  Bvid*.  and  Kikaliw,  iiMoloWi 
in  Hlcohoi  and  elber.  If  errnUiUixcd  fmm  an  alkaline  *oluUon  lyrtnin  oAv 
anHimo  tlie  form  of  rotetue  oooiputii'd  of  line  needle*  arraaeed  nAiAielf. 

TyrMin  doe>  net  ■ubllme  by  bi^aiiiiL'.  but  u  deooinpmed  With  an  odor  of  pbml 
and  nilrobenxol.  On  boiling  wiib  Millon'*  reageal  it  give*  a  reaction  alnM 
ldenli(«l  wiUi.  but  much  more  marked  tban,  that  for  nrotuid*  (ilnirmaa'a  tM^ 
If  tvroun  ii  irculcd  on  a  watch-gtaaa  trilb  one  or  Iwo  dro|M  of  wUoiif  Milpbtnt 
acid,  then  diluted  with  a  little  water,  oeaimlixed  with  calcic  oaxboflate,  and  tW 
•olutioo  lillcrul.  a  cbaracivristic  violet  color  t*  oblained  on  llie  adiilthm  al  a  iuf 
of  acid-freo  firric  chloride  (Piria'«  leit). 

Pftfuiralion.  Ily  nienn*  liniilar  lo  tlio*n  nnplorci)  for  Icacin.  llieBCftanUkarf 
the  tiro  ili'pcoitinp  on  their  widely  diircrinc  sulul>itiiirs.  Accmlinu  to  Kdkac't 
iDciliod,*  large  qusutitlca  are  eusily  ohtaiueJ  aa  ibe  rMull  of  pancreatic  iligeriiaa. 

Hlpptirio  sold.     C.n.NO,      Or  BMiRoyl-Blycin.     C,II,(C,IV))N<»,. 

la  found  in  comudemble  ^unntitic*  in  the  urine  of  herbinira.  and  aWi.  ihMlk 
to  a  mitch  amalirr  amount,  in  the  urine  of  man.  It  ia  (braied  In  the  body  bf  Ui 
nni'in  with  lii-liydmti'm  nf  i;lycii]  and  hpiiKoic  iicid. 

CrvolaJlind  from  a  Hatoraced  iiqucuiu  iiulution  It  K<Hume«  the  form  of  Am 
oeedlee:  if  IVom  a  mofQ  dilute  tiolutir>Ti.  white.  Miiiittnii«)>iti<>ni  f'tui-*id<d  friwi 
arc  oblained.  Tliwe  when  pure  arc  i>dor!cnt.  nilh  a  itomcwhat  bitter  lavte.  Thij 
tun  ■'iltibic  io  000  p>irta  of  cold  natrr,  rcadilv  luiluble  in  bolliriK  water,  mdUJ 
eolifblo  in  alcohol,  lew  (o  in  ether.     All  the  ■oinlion*  rcddeo  lilmua. 

Hippuric  acid  is  monobaiic,  and  fortiii  Mita  which  are  readily  aoluble  In  waur 
(except  the  Iron  salu);  from  Ihtec,  ifSuBuffictenily  concenlraied  aoliithxi*,  cxnw 
of  hydrochloric  acid  iireoipilAlea  the  acid  In  fine  needlw.  When  hcRtnl  viih 
coiiCADtnted  mineral  acid*  it  !■  rewlvcd  into  bentoic  acid  and  clycin.  Tlir  us' 
dcooBipnoitioD  occon  in  pretence  of  putrefying  bodiw.  tflrong  nitric  acid  prv>j 
duc«*  an  odor  of  ollrobenxol. 

Pr^tmition.    /WsA>  urine  of  boraee  or  oow«  U  lrf«ted  with  milk  of  liiM^ 
order  (o  form  calcic  hippuratc  and  thus  prevent  the  dconmpuutioo  of  ibr  hljifm 
acid. filtered. and  the  liltratc  eraporatcd  toaamull  bulk;  the  hippuric  acid  i*lka 
precipitated  by  nddinc  an  cxceM  of  hydrochloric  acid:  the  acid  ii  then  jwriM 
by  aeveral  crystal  lli.t  I  Ions  from  boiling  water. 

VVhen  hentcfl  in  a  *miiU  iiitie,  bipivuric  acid  given  aenbliinate  of  betiMtc  artd 
and  ammonic  bcriKonto.  accoDipnnied  by  an  odor  like  tliat  of  new  bay,  while  oUf, 
rod  dropi  are  obterrcd  in  the  tube.  Tbia  it  very  characleriotic  and  diatln|[abW 
it  from  neoxoic  acid. 

Ptwnytlo  (e*r*.iiM)  aeld,  or/»A»iiaJ.    (',0,«. 

ThI*  body  la  undoubtedly  oblatneil  m  th<t  mult  of  the  putrefective  ittau 
tlonofprotdidR,  notably  in  putrcfnciivc  pKncrcuiiciligeationL*    It  may  be  obi 
from  (he  dtrtillate  of  mch  dij^mtivc  mixtum.     It  in  aUo  fmind  in  the  cmilenlK 
the  alloirnlary  canal  Utidvr  the  same  ciioditioiii  which  kI"'  >>»<-■  t'>  indol.     Whl 
M  uecnrring  a  jwrtioo  of  it  may  be  obtained  from  the  fecea,  while  Ibc  rea4  i 
pears  in  the  unite.' 


■  Diittti. aicm.  i>ntn)h.. laca.fl.MaB:  tStK&Tn:  ISn&NM.    Ilnfwr,  IMH.  imu, &  laa 
■una  n.  Kaiiit.-fit  n.vi ,  irfrt8.«aft 

•  RrleniuDiv'  ' .<r. >l. ilcoMft.  Cham- itmUl, Mum. xr.fOKXS.  IML 

•  Oj-  rti  .• 

•  SUkOHlkl.  Ikl.  :i.    ImilJCll.  CIlBUI     I  I  .  .        -  .1 

t-ia.    Kfi.  4.  4«4U(4.  rtiau.  (lo«l 
«».    ate  alio  tVnlnlli.  (.  iL  mttl  Wi- 
ll. Iinm.a.  Ml. 


eilEMtCAL    BASIS    or    TUE    ASIUM.    UOUY.  lOdfi 

Bulif  latky  ■  wn  iba  urin*  of  nan)'  Miimal*.  or  cor*  uiil  hnm*  ■Imjri^  conUiiu  •  Mb- 
itouo*  iiiMlubIa  In  ilmliol.  Nnd  not  praetplUad  bjr  load  a<«l»i«  and  knuiiMtlii.  wlil«b  ky  Urn 
•rtHMi  uf  iltlal*  mlnvrBl  aoid*  p've*  aarboUr  avid  The  •am*  ■eld  afii>lii>i  to  Ibc  hodir 
•sUnulty  ■■r  iaUrailly  aUi  pawM  ialo  (ha  uriur.'  BiiniUrlj  bWHDl  <(Vtl<),  «h«B  lAhW 
JniA  tlio  ■kiniafU,  appt^ari  ■■  a  catbfllip  acid  In  Ilia  tirinc-* 

Til*  pure  acid  crntslluM  in  lonji;,  colorlmi  prinBiitIv  omJIm;  ihcy  meli  «t 
Vt'  C.  and  boil  nt  Iw  0.  It  m  rMdily  aolubk  in  alcohol  an<)  ctlitr,  BlifliUjr 
Hiluhir  ill  vraict  f^l  part  in  30}.  In  toort  caa«*  it  net*  Ha  n  Rcak  acid,  running 
cryaUiUinL' Htilia  wiili  the alkalitt.  With  nitric  aclil  {ljI»IcU  pimcncid.  IukiIu- 
tioni  reduce  aflTcr  mnd  mercury  wiltM. 

I^HjMmlion.  Bv  the  dir  di*tillulinn  o(  RalicUic  add.  rIdo  from  tlie  acid  pro- 
diU't*  of  the  ilUtillalion  of  coal.  It  ii  obtaiacd  in  Ihc  laal  portinn*  of  thr  dintll- 
lalp  when  preparint;  iiidul.  and  la  Mpanit«tl  l>y  furmiui;  u  comiHiimd  H-ilb  briHiiinc 
q,UBr,iV 

TltK  ttlLK  8KKIKS. 

OboUdlo  (or  eAi>f<«)  Mid.    U.CIIhII«Oj^   U,0. 

Occur*  in  Iracnt  in  the  Bmall  iniMtine.  in  larger  quantili«a  in  lhi>  contfiBla  of 
th*  luff  inloitinv.  nud  llie  ttctt,  uf  uii-n,  oow>.  mid  il<^.  In  ict«ia»,  the  tirin* 
often  conMina  trace*  of  tliis  acid.  Bat  it*  i<rini-ip>l  inirrwi  liea  in  lu  being  the 
aUrtlng  point  for  tbp  varinua  bile  acida  (■•«  lirlour),  The  pure  acid  may  be  amor- 
pfaoua  or  crjnttnlline,  in  the  lattrr  rate  crfoalli^inf;  fr«in  hot  Rlci>hi>lic  M>lutJoiM  in 
tOlraJtednt.  Theae  otjiUit  are  iuwilublr  in  wnlcr  an'l  vlber.  In  tbr  nmorpboM 
form,  it  li  aomewbat  aotuble  In  viati-r  and  (-tlicr.  Ilcnicd  to  -^UOp  C,  il  u  cos- 
verted  Into  mttt  and  dyilyun  (C„il„(J,). 

Tbia  a<:Kl  pcMiaata.  in  the  anhvdroua  coiidilinn,  n  niicdflc  rolatnrjr  power  of 
4-  00*  for  the  yellow  light;  when  it  crvntalliMa  with  II,().  ihr  mtaiion  ti  +  S3* 
The  roiMor^  power  of  the  alkali  nalta  I*  alwaya  loa  thnii  the  nlHire,  and  wbon  ia 
■olutloo  in  aleoliol  ilio  rotniinn  i«  independent  of  the  i-oni-eotrtuion.    For  the 
alcoholic  anlalion  of  the  nodiutn  utlt  ibe  rotation  ia  4-  31.-1'. 

/yrj'iraiiftH.  Ily  the  deconipmition  of  bilencida  by  mean*  of  acida,  alkalio*,  or 
ftrmenlativechanice*. 

Bajcr*  ha**xainiii«il  iba  Ul*  bci-t*  atrial oad  froiH  liuiuan  lillQ.aDilhaiprrjairv]  fnot  iJiau 
•hoUlte  aild.  To  ibii  )in  BMignt  Iha  Ibnaiila  CttTTi^i.  If  ikU  ba  •>,  ih»a  diutalK  a^id  of 
biunaa  bils  vouM  mm  b'  b*  a  body  Miili*ly  diflktvnt  ftow  Uial  ohtaiMed  beta  ax  blla,  and 
analyml  bj  Stndior.    lUyar**  ramlla,  bowwrar,  roifuira  fcrtbar  araCmaUoo. 

IVifiiio/er't  UtI* 

Thi*  well-known  toit  for  bile  add*  dcpenda  on  the  rea<Tlioa  of  cholalic  acid  in 

Kreaence  of  aagsr  and  «nlphuric  acid.  If  to  n  (o1iiiit>ii  >if  the  aoid  a  little  lagar 
e  addod  and  then  nuhihiiric  acid,  keepinfi  the  trni|irf>lure  below,  but  not  mucb 
below  'ff  ('-.  a  beautiful  rcddiah  purple  is  obtained.  If  diluted  with  alcohol  thla 
•nimiiin  givea  a  chamcteriMic  a|)eclrani  with  two  abmirplion  luod*,  one  betweeo 
D  and  E,  neare*!  lo  K.  the  otlivr  cloae  to  F  on  the  red  aide  of  V. 

The  reaction  i«  mnrh  inipoded  bv  the  preaemv  of  colorinf  matter* ;  morcAver 
pcoirid*  and  other  liodies  eaaily  deconijioted  by  aulphurie  acid.  Much  at  amyl- 
klcohol  and  oleic,  t;lve  u  niaillar  reaull ;  ihe  colurint;  matter  iiroilunHl  from  iMM 
bodlea  di>»  [i<>i,  hifuevvr.  ^iie  the  abanrplion  bands  deacribed  above.* 

Olyoocholic  iMjld     c,u„No,. 

Thta  body  waa  firat  obtained  in  the  erratalline  fom  and  dnaerlbed  by  Unelin 
(1828),  who  ^ve  it  the  name  of  "cbolie  "  acid. 

To  aToiJ  eunfuaiuu  It  la  u>iw  b«t  lo  ■■•  tlta  Imib  ■■  eba4lo  '  a*  a  •^uiiaym  b*  "  aftDlall*,' 
Dafnarmy,  who  f nl  ( I938j  ibacrlbtd  Ilia  elioUlia  and  a*  a  pmlort  of  Ilia  ilaeDaipoaJUoa  of 


•  Uopp^dnlar.  Uol.  rbein.  l'nK««i«h.ll«nit.  ID«7i».3t 

•  AlSln,  ^«ii»JaatlL  .1.  riiani      ' 


__^ .  inn..  M.  uiir-^-ltl.     SaltowiU.  r«*(*r>  Artklr.  Bd,  T,(Un-ni 

•  IkfenlUpn  IL  Xatiujii,  Hclobim  <L  ina^lM* VMrntm-it  Anbl* ilMI),  tUA  10.  S. aW. 

•  7eIi^'I>  r  i*>T^tt  Ctnm.,  M  n  il«nbTMlLjM. 

'  t^liitiV>.n.-r,  Ankalni  il.  riKK  K  lliarm  .  M  lit  irHli<>.««. 

■  •  KaninliM  liilOrauUan  mi  (hUi  »■"  t-  .   -     -    -.        i     r     .,<  j(«J,.  i^v  ;i.  fiit  tii  n.  ur>. 

■  ScAultB.  aaa.  O,  i^htai-  ii.  rbanii.,  |i.  vnaloni.nlinlul.  I  nurnHdi.. 

■  infa.t9n.&n.     A4uBkW«tra.riv< 


APPK^IDIT. 


Ula  ai-i-b'.  Iiarltiii  |;h-«ii  it  tlio  t»in»  of  ahollo  mtU.    TW  tuiiw  rhoUllr  t> 
iinre  it  IjiiliublBi  IliD  Dialhoil  t/f  vliirli  (be  blla  Wlldi  U«  ijillt  ii|>,  vlL.  t^  I 
■ItaUi. 


This  in  thi- 


ipal  bile  acid  of  os-gnU ;  H  w  alin  pnywnt 

'  jii  iif  ciurnirora.     In  icicrut 


thr  lillr  of  1 


n  1 


'  ]>nnc)| 

[ilHcrreil '. 
coiibuD  Unoes  nf  (bin  atiO. 

tt  i!rj*ullisn  in  nne.  glintc-tiiue  ne«<llM.  TlieM  u«  aUgliily  nohiMe  In  oaU 
water,  readily  m  in  hm  wnlor.  Bn^falocihol.  but  Initolable  in  eilicr.  Tltcj  pomm 
a  t>ill«r  unci  ypt  airci-t  tiuir,  and  il  »tn>nv  acid  r««Ctti>n. 

Tbe  sails  or  tliia  acid  niu  readily  ■nluble  in  nkirr  and  crjutiillttc  mcIL  Tb 
mIu,  an  nell  AS  ihc  rr««  acid,  etm  rifilit-baaded  puiariiailun  aniounlinc  k 
-f  29.0°  for  tlic  ncid.  and  ■+-  25.7'  Tur  thu  todium  uli.  Iioih  meaMittyl  ht  yJltv 
lijrbu 

Oilyoncbolic  acid  i«  n  caoaptiuud  of  glycin  and  choUltc  a«id ;  Uiu*  : 

rhelnlir  •ad.     Ol»i>io.  (ll»por|ioli>  »pi4. 

C„II,0,  +  C.SHji)  — 11,0  =  <\,l'o>'W*- 

Prvlm^ed  boiling  irith  riitnte  mincml  uilitie«f*«>lli!iilk>ll«  JprampnMa  etvmrlMUxM 
Intoilyp-'i  IF'.'  -liilnlicMM;  ifiliMolvnH  In  mnceiitmlM  inil|>t 
cIddwIi"  ' .  llio  rsnoTal  of  xrie  laoliw'lla  of  wal*^  ywl 

The  b»ri r'  ihi*  l»i  BTv-l  it  iBX-liiblc  In  nlrr,  wtiioli 

ebolcnlc  iivi-l  fijn*ue*  DMTly  ilio  mwio  qiMllli)  rotalocy  powor  x  xivwicbutiu  liui-l. 

TViTiaroKoit.  From  ox-gall  by  <rvapomti'>n  to  a  <yrup,  dt-coloriiiog  with  rdIbiI 
eharcoal.  cxtraviio^  witli  Mrong  uli^bul.  uml  |)n.-cit>ilntinK  by  «  Itrgo  eirtw  ij 
cth«r.  It«  »e]Mratii>a  frvm  Murochulic  ai-id  dci>«iitlB  on  Ita  iirecipitMluo  b;  a*- 
mal  lend  oLvlalc,  taurocholic  acid  not  being  i>reci(>iuicd  by  tLis  rengent. 

TBurocholio  oold.    e^n^NSo^ 

(h^curx  iklxi  in  Dx-i;all,  but  b  found  Mpocially  plvntiliil  in  banian  bil«  and  Ibt 
uf  cnmivoru,  (loUUy  of  tlio  dOK' 

It  cryiilutliti-B  nit'li  difliculty  in  veir  fine  nccdlts,  which  arti  tfxctvdiaglj  il» , 
UoueAoent.  When  dried  il  !a  mi  aniucfiliiniH  pi)wd«r,  with  iiuru  ktt(«r  i 
(olublv  ill  water  and  alcobol,  insuluble  in  ether.  Alt  ita  ^iiIIa  ore  iinluh)*  Inwala. ' 
and  are  precipitated  by  basic  lead  acclntc  in  ibe  |>r«aenM>  of  fre«  sinmitnlA.  71* 
•odiiiin  lutt  diuiilved  in  alcohol  bu  mipecific  natatory  power  of  +  If 4.5*';  if  4^ 
•olvcd  ill  water  tlii*  routioD  ii  loaa.  And  in  thin  reaped  il  rcMtnblM  i^lyondtallE 
acid. 

This  acid  if  fur  more  unstable  tlian  ibe  precediog  one.  belii^  decomnoant  il 
boiled  with  water.    The  products  of  decompoeition  are  tauriu  nuil  cbolalic  atniL 

Taumcbolic  acid  is  a  <xiHip<iund  -if  taurin  and  cholnlic  acid;  thus: 

Cliololk  aci'l,      Taurin.  Taiiiwbolic  Mid. 

<''ii''wy»  +  C,II,NO^— 0/J  —  C,HuNO^- 

iVijMtrafim.  From  the  bile  "f  dog*  by  a  pmoM*  aiinllar  to  ibU  for  g\yt 
add.  It  b  nparaleil  froin  Irsceti  of  ibis  lalier  and  IVoin  cholalle  kcid  oy  \ 
Uaioa  with  basic  iMd  acetate  and  ammnnla.' 


1(1 1.B  Piouxjcn. 


It  ia  found  cbidly  in  llie  frwh  bile  of  man  And  otmivnni,  to  which  It  ^i 
cbaraoteriatlo  dark  gnlden-red  color.    It  frequently  ci>ii«titu|ea  a  oonaiderable  ] 
of  MNDC  kinds  of  gnll-stODes.  not,  however,  a*  ftM  bilimbin.  I>ut  hr  a  compoai 
with  e«rlhy  malter,  cbieRy  chalk  :  the  gall-stones  of  oicJi  and  pig*  iiTltM  eoDUtn ' 
40  p«-r  cent,  of  Ihi*  coraponni).'  These  are  tfaerefhre  the  best  natenal  fmm  whkb 
to  prepare  bilinibin. 

PraftamtioH.    The  ft" H -*(■>■■  e*  are  trOAleil  with  «lronE  ncdie  or  dilate  hy^r»- 
chlnrle  Add,  tn  sepArate  the  eartbf  niau«t,  and  the  rcHdoe  ia  thuruuKliiy  washed  j 

■  ll(kv.TtiMK.)f(>4..obiin.i;iiwn..Bil.l.3.M(ii 

•  Xalr.  aitilNr.  d.  WKn.  Itad..  M.  Irtt..  I«H,  II.  AMk.  V^M-  IIII. 


CHKUICAL    UA&IS    UP    THK    A.VIJIAL    SOUT. 


1067 


ralcT  nud  alcolH))  tnd  dried.  From  Diiit  nnldue  ihe  ]jn}Iong«(I  autlon  of  hot 
cbloroform  cxirecta  ifae  btliiubln.  wbiclt  may  Mtber  be  obUuacd  in  tb«  smorpboiM 
form  bv  ivrpci|))tntion«rith  ftU-i>Iii>l  nrilatmlutioa  in  cblorofbrni,  ofm  wcII-Hcfimd 
cri[irUli>  li>'  itit  iiliiR  rT*)inraiioTi  of  ihe  chlororonn  nolulUin. 

T1i<>  DxHt  uminl  fonn  of  tlii'  crymulii  is  thAt  of  rbombic  prisinii ;  ibe^r  At«  reudily 
•oluble  in  cbtoroforai  and  nlkatino  solutions  only. 

By  irrainierii  irtlb  oxidinn^  n;tcnt*,  tiu<-b  as  niirou*  acid,  bilirubin  takn  np 
oxjgra  and  brcomto  biliriTdin.  thn  rnlor  nl  tbo  nunc  lime  chan^ng  Ui  i;re«D. 
Tbt  MMaibk  oxidation  doM  iml  end  here,  and  if  contiuui'd  a  ncrie*  »(  prudiiL-ta 
an  owalnfd.  each  with  a  cbaracttnMjc  color,  n»  in  tbe  wctl-known  Omelln'a  teat.' 
Of  thme  only  ihe  Hnnl  product  of  thf  oxidation  ban  been  oblainetl  in  aatale  of 
f  DlHrient  purity  lo  nmbV  niiy  dpfinit*  ■tntruicnla  to  be  made  of  it«  chariLct«riatic».* 

fcThi*  i«  ibc  btidy  kn<iwi]  a.i  Ctioli-ielin  (>ce  below). 
Biliverdln.    C„U,.N,0,.' 
nb  iRoiluct  of  the  oxidation  of  blliroldn  gire*  tli«  cbaractt^riiilic  color  to  Iho 
le  ot  neriiivunt  and  Id  biliary  vomlu.     It  oocnr*  also  probably  at  limen  in  the 
•iilnr  of  jnundk-r  and  in  tlie  piftntcntary  loaiter  of  the  placenta.     It  lo  fonnd,  m 
oecan  in  imcc*  only,  in  gall  tttonp*. 

tWfamlioa.  An  impiirr  prodmU  t«  obtained  br  prccipilnlitif;  ordinary  hrr- 
blvorou*  bile  irilb  baric  chlorid»^,  ivashini;  ihc  jiiccipilali-  with  wiiter  and  alcohol 
and  dccoDiiKMlng  it  with  hydroi-hloric  acid.  The  blliverdin  tbu>  obtained  U 
waabfd  with  elber  and  diHtolvcd  in  alcohol.  From  ita  anluUon  In  the  latter  it  i* 
obtained  M  an  nmorpboun  green  pnn-der  by  nlow  evaporation.  I'uro  bJlivridin  M 
b^t  prepared  )>y  the  slow  oxidation  in  Ibe  air  of  bilirubin,  diMMilTcd  in  dilute 
oumicwida. 

Ii  da««  not  crvBlalllce.  and  »■  liinnlnble  in  ether  or  chloroform  ;  readily  ivilublu 
in  alcohol.  When  nxidixed  it  f.iv<r*  the  oarnD  play  of  cotura  mj>  dOM  hiljniblti, 
with  the  furniation  of  tlio  vatne  final  and  inleniietliale  ptiidnela. 

Neither  thi>  body  nor  bilirubin  girea  any  cbanicierlNtic  nimorptioii  haodn. 

Tfacre  Mema  now  no  reaaon  for  douhtiiiK  tbal  ibe  bile  jilgmenta  are  derived 
nltimately  from  ibe  cotorinp-  matter  of  the  blood. 

Vircbon  ha*  dracrihed'  tbe  gradual  cbangoa  In  old  blood<clots,  a«  of  cerchral 
beiiiorrbifp',  which  lead  to  Ibe  jirc^cnt'e  of  the  iw  called  bwmaiiudin  cry«tala. 
Though  tlieae  ba*e  not  been  obtained  in  HUtScient  <iuantili««  to  enable  their  com- 
poailion  to  b«  finally  tlxed  l>y  a  obemical  analyslo.'  tiill  tbe  Identity  of  tbeir  cits* 
tolllne  rorm  with  that  of  bilirubin,  and  the  fuel  that  they  both  give  (he  aame  play 
'  of  Golota  when  oij.lixoil.  an  In  itmelin'*  ie»t.  jimtify  tbe  awumption  that  hinaia- 
(oidin  and  hilirubiii  are  identical. "  Moreover,  the  balance  of  expen'nirntal  evi- 
dence diiliuiity  (upporL)  the  view  tbut  a  Uberatlov  from  the  corpusclen  of  lb* 
coluiing  matter  of  tbe  blood  In  tbe  bloodveawla  by  aii  Injedlon  of  cbloroform, 
water,  etc.,  teada  generally  to  tbe  appearance  of  btle-piKinoniM  In  the  urine-*  Tbe 
uccarrence  of  bilirubin  crynlBlii  In  the  urine  him  frcijuentlir  been  obaerrcd  after 
tbe  operation  of  tninKliwioti  of  b1<>od  in  man.  The  ebemica]  paaudbilily  of  the 
Ooa*eralon  of  bietiioi;1iiliiu  into  hilirerdin  b  readily  aeen  by  n  coaip«rii»on  of  tbe 
Ibrmul*  of  hamiatiu  (M-e  p.  iSi)  and  billrutitn.  The  (urmer  baa.  accordinu  to 
IIoppe-8#yWr,*  the  coini'oiiiion  Indicalfl  by  Ihe  furmuln  2(CHll,N,Fe(\)  while 
that  of  hillrubm  i*  ('liHi.NjO,.  Allbough  ibo  convel«ion  \uu  not  an  yel  been 
directly  elfectcd,  the  tollnniiig  facta  are  ■ifiniftcant.  If  bilirabin  i*  trenlitl  with 
fodiUBi  amalcam  theaubatauce  known  as  hvdroblllrubin  (see  Wlow)  it  obtained, 
ir  biemaiin  Cidiaaulved  in  caustic  aoda  ana  treated  with  mKlinni  anialviui  ur  in 
hydrochloric  acid  vilution  with  xiiic  dud,  a  nubHtiuicc  In  ohtaincil  whii'))  i»  now 
rceopii(cd  aa  identical  with  bydrobilirubin.*  Tbi*  I*  Ibe  most  direct  cbetnical 
evMeace  of  the  relation  of  the  coloring  tuMtera  of  the  blood  and  bile. 

■  ItodnaonunitainellD.  Dtn  VrnUuuni.  ISH.&n. 

•  Rendu*  unH  Cuni'lHtt.  l-Uuvti-i  An-Ii..  lU.  It.  iiniL  &  «7. 

•  ilal7.«Ub.<l- WItii- Akwl..  Al  lii.|lK4i,lll.  AIMb. 

•  Aran.  1  paih.  Jtiwi^  l»l  >, »  3-a. 

•  BetiD,  AnD.d.Cbem.u.  rtiftnn,.  Od.  ciM,  8.  Wl 

>  TMdiaaoir.  niVMr->  Anh  .  I^  IxilKO,  8,  «L    Sm  atn  Bd.  a  lUm.  *.  9)1. 

•  nvtfOlOKlKbe  CTwmle.  isn.  a.  m^ 

•  ksfn^nln.  Ucd -cUfflD.  rnMfeuai.  B«n  Iv.  IBIL  &  901.    Bcr.  d^dtnixti.  <b*m.  Q«mU-.  *V. 

07 


AfTKyVlT. 


Thin  *ulMlaiioeiNobUineA  lulbe  final  pTwIuct  of  Ibi-    '"  ''        '    i' 
rabio  ur  liiUi-erdlii.     It  ir  hv^l  I'reinrod  liy  M-iinu  u|>^< 
■dil  In  praMdconf  aI<^i1iii1  ;  tlic  vniioas  colon  iif  (Iciieliu  ■  >^.:l'  i'--i'  -•■  ■ 
ud  the  fin*]  redilUli-vpllow  i-aliiiion,  ir  p<iur«>l  into  wni«r.  j i«l<lii  ii  pf 
nholftcliii.     It  U  not  vrvKlnlliao  >nd  U  loliiblr  in  ■luoliol.  rthrr.  and  ivi. 
Wlion  iVntit)-  jiTcpiued  It  tMUiu  to  gift)  ma  unci-rlsin  nlnurption  )iAn<t  if  ex 
in  an  <jn<l  Hitutlon.    On  thh  acvouul  oomc  obipntnr  line  brco  l«l  lo  n-i_ 
Bt  lilcnlicHl  wilh  tiT<)rotii1inibin  |urt>ti<lin|.    Tb«r«  ia.  Itotrercr,  no  doiiU  Hut  thn 
aiv  <)uit^  distinct  biHtiisi.' 


HydroblUrubln.    CaH^N.O,. 

Tbifl  brtdy  nM  firet  dnuiribcd  bv  Maly*  iw  mulling  TroiB  the  acttoB  of  Miliiua 
■Kialgam  nn  an  nlkslint!  I'llulion  nf  bilirubin.  Wbca  Ihv  rMrtion  l«  cam^ru 
the  tolullan  i*  pntcipiLaiiMl  wiib  liydrocbloric  acid,  the  pr«cipital«  dixolvM  ia 
aminaiiia.  again  {yrvcipltatrd  by  ncid,  and  Uie  sub*ui>u«  thui  finally  ohuin4«l  U 
wwbcd  ailii  water.  It  ie  rcadilv  wilublv  in  aicobot.  Itm  w  In  etber.  Iia  aikaUar 
4olntion*  an-  rcllov,  and  titi-a*  turn  pink  on  UioadditMn  of  acid.  Dotli  ilsicU 
find  allcnlinr  mlutiuun,  tbc  hitter  eapecrallj  i>n  tlir  ■ddition  of  a  tev  dropi  uf 
chloride  of  xini-,  jcive  a  i-barainoriillc  abaorption  band  bciveeu  b  and  F.*  In  lb* 
coloni  of  Ita  alkaline  and  acid  !in1uttnn«  and  ibe  greeulab  ttuoraacenci'  of  it*  aaaao- 
nUcal  aolution  in  tlic  addition  of  chloride  of  dnc  and  in  ilRabaort>iioo  •iwclnia 
bjrdnbilirubiii  nhown  itn  vlme  relatiuu  to  urobilin  (>c«  bclmr),  vriib  which  iBdM4 
it  ia  now  oTuJilertHi  to  bo  identical.  It  la  aUo  ideutical  with  a  bodjr  luiMd  *bc- 
cobtlhi'  wblcb  hK<l  jirevioiisly  been  dMcrlbed.  as  a  product  of  the  alteration  of  ihr 
bile- pi  gin  en  t*  in  the  ntioioota/v  canal  occurriiijf  in  fecm.  There  ia  do  diScnkj 
in  MeiiiK  liow  llii>  chani;i-  (hydroeenation)  can  be  brou](bt  about  in  the  inteadK 
ffnre  it  t>  known  tbai  n  iroiialderable  <|iiautit}r  of  hjdroKoo  tnay  mak<'  it*  appav- 
ante  by  feriii«niiitlvoj>ri>ceucfl  In  the  ioteotine.  aud  in  ita  niuceot  itale  mi^t 
raadlly  timdiire  the  niinpte  change  which  ia  known  to  occur  when  bilirubiD  ' 
convened  into  brdrobilirabin. 


I 


PioHcicnt  OP  Uuxs. 

Our  knowjmlge  of  theae  bodies  U  at  prcwnt  limited  and  impvriaM. 
probabt}'  tbe;r  are  numerous,  but  only  t<n>  appear  HUlScienily  well  chancUriifd 
to  deserve  mention  here. 

Urobilin.    CJlJSfi,. 

An  itatvl  above  thia  is  now  rvitartleit  an  Identical  with  brdroblllrubED.    Il  i 
liret  df«cribml  bv  JaflV^a*  n  well  i:hnnirtrrit«d  normal  urinary  pigment  ud  lO  ' 
identity  with  hyarobiliruhio  inibie<|oi>nllT  deti-rininc<l.* 

Normul  urine  conlaitin  only  amnll  iiuaotitieH  oi'  urobilin  but  iherr  ia  prcatM  a 
•nbttance  (chroninKon)  which  under  the  influeiK-e  uf  acxi*.  with  abnorvtiM  ^f 
oiygun.  yield*  urobilin.  The  urinr  of  lever  frequently  i-ontaiiiit  a  con*ld«nbl* 
aoaount  of  Hrliial  ortibilin  ai  aueh. 

The  jiroiiertiiM  dracribed  above  for  hydroblllnibio  an  identical  with  Ottmrnt 
nrobilin.    Iih  prei>«r«l<on  from  urino  la  Mmewhat  difficult,  and  for  thia 
apeclsl  nianunl  tniu't  beconnuUud." 

>  MMy.  AtilL  •■  WdaAkaa.Bl.lrtXItMliIAMIi.  Pltr..  iind  M.  Itx.  IMt:  «AUlli .  AhH- 
am  Ihjnilu*  mA  liaBpbrtl.  Ute.  clt 

>  ]|ifFiul«* mwl  OnuMell. loe.  liL   Slukt1i.Ouiii>Ib.  td.  ued.  Wlw.,  X.s  itilnTJi.  a.m,  I 
•Ma]y.CautKil>.tdBed.vnu..No -ii<i«fi(.a.ci.   UttonMon.l-nLMn  Anh    iiiuiikmI 

KtH.  ■-  1 

•Vnnmlvr.  >1.  mnl.  Win..  .\o.»Ltm.    AniHl.  d.  Cheifi.,  Ud.  el(IU(U»l,&TT 
'  \-leranll,  Z^l  ■  -  h   r  n,.i  .  M.  U  (IKSva  toi, 
•Vnuulriiii  i.inlb.td  nvl.WIM_Xa.XI*'!. 

'  VKronl:.  i'  :  •trinKlaUDalna.  *tK.  TnUncm.  fCC-A  U. 

'  Wnlrall.  '  ■i.tMBLS.-JU.    Vlfeliow-*Ai«k.,M.altU<t«9l.am 

*Hal]r.ADii  J  i.Ua>.  u.  rhariu.-lkt  clHll  (ICrA.  H  ff. 
-  VI.I.-  .SViitxiiU't  and  VofrL    lUrnansIpD.  rI.  Mil  (IM)),  &  *!. 


CHEMICAL    UAiilS   OT    TITK    ANIMAL    BOOT.  1059 


lb  VniSitni  lu  be  the  •ulMlam-c  which  k>v«  to  tlw  otine  of  rbcummti*m  it* 
dwactcriilic  color.  Wrjr  littl«  n  koowii  i>r  {ta  ch«iatcal  |tra|>«Kl<a.'  It  npfwam 
10  bv  in  ■morpltoim  ivJiIirIi  body  nith  uii  nci<l  raactlon,  nlowlr  soluble  in  water, 
»lcobi>l,  Htiil  rlher.  Whrti  tmttrd  with  cAUntlc  nlksli  i[  turn*  grm-n.  Urine  TOO* 
lAlnioK  this  bixlr  tnlttii  on  ■  i'haractf-ri>lic  rcddiith-yelliy*  color  on  the  addition  of 
riinc«ntiiite<l  h/droclilorlo  acid. 

Ikudldiuio  ocoitiilan  that  ooruul  urlno  Mntolu  aalf  oaa  pIsiMHI,  wlilch  he  <alU 
■rodirona.*  Ma);  i*  iiidioi^  v-  minnl  thi>  u  the  ntiia  m  iirobiiin.*  Mora  rvcvnil; 
nmdldiaiu  bu  oplislil  lib  furirivr  viuwi.* 

TuK  l5i>tao  Sbkibs. 

iQdloKD-     C.U,NSO,. 

A  bodv  WKi  IiiiiK  uffo  dniL'rihrrl'  uoccurrinjc  in  th<'  urinp  iin<l  iiwnRt  nf  men  and 
otlier  aninwlii  wliiuh  yiFlcieJ  by  tlie  action  of  ncida  the  hliie  colcirinjc  inaltL-r  indigo 
Hsoiieuf  lh<*  prodiiclAof  ilsdecauipmitioTi.  8ehuiik  cun«itler«(l  thia  Bubstiuoe  tu 
Im»  idenliral  with  the  indicaa  known  to  occur  ioiev^ral  planlo  (Indlgnfera,  (lalla). 
Ho|i(ie  Se.vler.'  on  the  nthrr  hand,  having  r^ard  to  the  urcater  cuuie  with  wbicb 
(he  indican  from  planbi  undrrgoea  deconpoaition,  reKnrdcd  Ihrm  n*  mtat  probaUv 
difliBrttat  ■ubstanom.  Banniaoa  haa  «bo«D'  that  Ibe  two  are  really  different,  and 
hM  eoollrmed  hia  earlier  ntulemeRtK  in  n  more  recent  publication.'  AccordiiiE  In 
bioi.  Ibe  indicnn  obtained  fmni  urine  is  not  a  ^lueotide  (m  alao  noppe-i^efTer) 
and  yirldi  ititiihuric  acid  by  the  action  of  bydrochtorir  acid.  lie  aaiiirni  to  it 
the  furuiulu  C,H,V.O,SO,.0)I.  and  regard*  It  ju  induxyUulpbaric  acid.  The  acid 
Itaelf  19  Dor  ret  known  In  the  free  stale,  but  i<  vleid*  atabfe  aalta  aueh  aa  tbat  of 
potamluin.  C'jI.X.SI)  K.  It  on-ur«  largely  in  the  urine  as  the  rwult  of  the  prea- 
<iitt  nf  indol  in  the  Hiimeiitary  mnal.  In  thi<  nay  llaumann  aod  Hrie^fri'  wore 
eiiablrd  to  obtikin  laritc  <|uanlitieB  hr  i;<v'')|!  indul  to  a  doK>  I''or  it>  proparatiaa 
ibeir  original  paper  mint  be  cunaiilleil. 

Wben  treated  in  aqueoua  Koluiion  with  hydrochloric  acid  iu  presence  of  oxygen 
it  yields  indigo  blue 

rc,H,NSO,K  +  O,  =  SC,H,XO  +  SKUSO,. 

It  ia  always  otimaied  in  urine  by  conrersion  inU)  indigo  blue. 
iDdiso.    C,H,NO. 

It  ia  firiiipd,  a>  ulated  above,  fmni  indican.  and  giro  rM  to  the  bluiah  color 
•omelimn  'ibierved  in  sweat  and  urine. 

It  may.  by  *low  fi>r[tiitti'>n  from  indican.  be  obtained  in  line  crvstals ;  these  are 
inaotuble  in  walor.  •lijchtly  aotiible,  with  a  faint  violol  color,  in  alcihrtt  and  ether. 
Obloroform  aUo  diat'ilves  ibeni  to  a  aliaht  t-ttent.  Indigi)  h  loluble  in  itrone 
Milphuric  acid.  I'urinioK  at  tbe  tttme  time  two  compuaiiaa  with  tbi*  acid :  Lheie 
■re  Miluble  in  water.  It  poweaees  ajture  blue  color;  when  presied  with  a  hard 
body  a  red'tlnh  copper clored  mark  M  left,  and  tbo  orytlats oshihit  the  *ainocolof 
If  seen  in  retlocie*!  licht, 

Tbe  luliible  cmnpnundii  witli  ■ulpbiiric  acid  give  an  ahionitioQ  htkinl  in  the 
niiectram  which  lies  cIum  t»  the  D  line  and  to  the  rtd  side  ol^  It.  This  may  be 
iMOd  to  dried  iadi)*o. 

Treated  with  rediicinit  a^ont«,  indigo  i«  dae^loriMNl,  beioK  reduced  to  ioiligo- 
while.    The  latter  coniaina  two  at'tma  more  hydrofreo  than  Indigo. 

<  Hclki'*  AretUviIifli.  mnvxi,  ^  mi  i  BiiLM«d.n  .  N.B.M*  W1.  |BSI,  p.lM- 

•  Mal».  Ann  rt  Chi'm  u  nuit™  ,  I'l.'  oi    liTt.  *  M- 

•  JmrB.CIwui  s>eL,H«  ;.ToiiiIni'<:i;.pfiiM.«il.  _ 

*i«hllilk.  rtilL  »u.  val.  X.  K  n.xiT,p.2X:  XT.  pp.  A 117.  m  nKOLOBMnlb..  ISM,  8,10; 
Uar,a«TllBML»  W.  Il<>pi'«-ite;l>r,  Anh.  tpalli.  AuauBl.iiTU.  am.  Jsdk,  l-AU^M-i  Arab  , 
Bd.hl(t89m,atM 

•  Oiadb.  d.  vxh  Chan.  Anal .  VjI  iTfiniii,  8.  m. 
'ntnnr^Aitik.,  M.  alUiixTit),  s  nil.    ZalMCkr.  r.  pliT«laL  Cham..  M.  lOVn-ln.  &  a), 

•  ZsMHh.  t  ttjial,  Clifn .  h>l.  Ill  nont.  a.  »*. 
*tilmai.tttr*iA.nem.nn  iuaWf.iW    aMal*envr.d,a«uMb  ClMm.a«silUall<Uin. 

•D.U01U1S,  nM:asdaUI  <UWj.«.«M. 


loeo 


APPENDIX. 


Indol.    C,n,N. 

To  ibh  body  (li«  gpecifli:  cwlnr  or  lh«  fecn  >«  Pflrtlr  dor.     It  to  obuioMl  I 
liiinl  prnduci  of  Ibc  reduction  of  indigo,  mnl  mi»i>  bjr  ih*  dinlilUtiun  i>f 
natlcr  with  nuirtie  alhnlim.' 

Il  olirn  <iccun  among  the  product*  of  (h«  ai-tion  of  paDereatk-  renDeni  ob  piu- 
teldt;  its  jimence  in  eiich  chbm  appean.  hovevei',  to  b«  due,  not  to  th«  acUoD  nf 
the  trymin.  but  to  ■  *imultnncoiis  piitrvfaction  iindrr  ilio  inlluriu-c  of  baeUhi, 
etc'  If  tbo  puncrratii:  diftmlion  be  carried  on  in  the  ytcrvncr  of  mIk^Iic  add, 
indol  doM  not  tnak«  lla  appi-aTPiice.  Iitdol  b  a  cr^aiafliiM  body,  aolttble  In  ball* 
Ine  wat«r^  alcohol,  and  cturr.  Il  paait»  ov«r  in  ilie  U^am  «h«n  Its  aijutem. 
HnTntloD  IB  boiled,     Il  le  chnrnclcii/cd  by  tho  Ibllnnine  reaction".     ,\  »ui\i  ii% 

Sine-wood  moinlcncd  with  hydrochloric  add  i>  colored  briftht  rtiniMin  oiira 
ippcd  into  a  solution  iif  indul.    It*  alcoholic  iioliiiion  luriin  red  «hen  traM4  ' 
Willi  nltrouH  ncld.  aud  !■■  aquvoiis  iiulutioii  gIvM  a  copiotiH  ttd  pieclpiiBt«  wU  , 
the  Mnie  rcsgtnL     It  also  jieldA  a  chars ctrristic  crT^talliDo  oonpotiMl  witlij 
picric  aciil. 

Skntol.    C^,N(T). 

NolJc<^  by  HricRrt'  a*  onr  ol'lhr  producl*  of  pntrefnctivr  chan|[<-ii  in  the  until 
inieatiot.  I?«crrtun*  had  previously  dmciiWd  a  tiniilar  *ulBtaoi.-c  an  eriBing  frMi 
th«  putrefaction  nf  Hlbumln. 

Skatol  ia  crjMallinc  and  c/intaiua  nitrogen;  iL  ia  mor*  aolable  in  wain  dian 
indol.  and  doc*  not  pxi-  rii>p  to  any  r«d  coloration  with  nitrou*  acid. 

Skatul  readily  pa»M  into  tbc  uriue  when  it  uccora  in  tlio  alimentary  canal.  a«d 
then  KiveB  a  viulet-red  reuction  with  Mroog  hydrochloric  acid. 

T.  Kenckl'  prepares  this  (iibatance  by  the  jiutrrfactlun  of  a  niliture  of  Knrif  ' 
diTJded  pnncrena  and  Biiiiclc  siibKlHiicc.  After  the  addition  of  M-elir  add  th*  i 
Biaxt  iadiriillcd,  when  the  skatol  rendilr  piiuc  over.  Frcni  ihi-  dinlilUt*  Il  m 
precipitated  by  piciic  Mcid,  and  the  predpitate  when  attain  Oi>>iiltrit  oiihanii 
gives  olF  pure  alialo),  which  a>ay  be  finally  puriSexl  by  cryatalliaBidin. 

I  KaLno.  B«r  il  dtuiKh-  cbcni.  (looU-  Mil.  Jlimi,  B,  JBO. 

•  KUbiir.  VsfliDiKl-  HcliLIIi.  I>uliiil>ltl.-iiit4.  Vcr.,  ii.9.,  Bi).  i„  BR.  1.    BsrtMild.  tNrvUolm  (kiw 

0,^.ii^ti„n  ivT.  n-jj*. 

|W^.  rlicm  UvhI).,  J*)iFi;  i  ilNTTi.  I*.  1(97. 
■  I  -III  iPtitrrrBfildii  ilu  I'ulliuniiiit,    llaiioin.  I'M. 

■L...,,,.,L.  ;.  il,  luiiiJ.WlB.,  JKW.JLM1I. 


INDEX. 


ABSORPTION",    from   olimenlurv   ramil, 
4111 

uf  ilittuxilile  siilh>tancei<  imd  wat«r,  4'26 

of  fnw,  4'2a 
An.-nninicKln[ii>n,  «9S 

nierhunisni  of,  8i)8 
Atrtd -albumin,  KVi 

formntinn  of,  :in 
AciiL  a.H|>arlic  lUo2 

lieiiznic,  lOii:) 

Imlvric,  1037 

cniiVi.',  103H 

mpmic,  IftiS  ■ 

ra|)rylic,  HUB 

(■lir>rii',  lOVi 

«?lii_vlene-luctip,  1041 

ethvliiltne-  lattic,  1041 

fiirniic,  IC^tT 

f(]iiliiminic.  10<'>3 

Bl.v('erin-j)li(w|ihc)ric,  ll)4-! 

Klyc<K'h<iIio,  low 

hypiiuric,  III.Vl 

kvnurenir.  1051 

lactic  I  Ml 

laiim-slL-uric,  lO^tS 

mvrwtic,  103S 

oli-ip,  iO:ti> 

nxnlic,  1042 

inlmilio,  lOikt 

|ilicnrlii',  10">4 

liniprinnic.  10:iT 

wircDlni-tii'.  1041 

Mlt-nric,  IIWM 

Hiiifinii'.  1042 

taiiriH'linlif,  1056 

vnU'riniiif.  lOHM 
Ai'fluKlic  a|i|)iiratii»,  1)4(( 
Adlpiiw  tissiif.  Iil4 
AHiTonr  iiii|>iil*<,  1172,  K55 
Afler-iiiindes  iii'ipitivi',  1)24 

jjiwilivc,  !'24 
Al™nlr>in.  Hl'Ml 
Alliuniin,  iK-iil,  HIIK 

nlkiili.  Kll'.) 

ilcrivol,  1<ll4 

pffU,  1017 

nalive,  lOlT 

Htnim,  il>l7 
Albimiiniiiir'  jrliirnis,  1S2T 

ohmiKU-i  ill,  'liiriii;;  Myrctiim,  .141 
Alimcnturv   c-^iiiu1.   tmiwiis   iiR'niUraiiit  of, 

aiT 

mii-ioiiljir  c'lal  <•(,  ^117 
utrurlilrf  rif,  :117 
HiibniLiiiiu-'  •-■oat  of,  ttlS 


]  A I  kali -III  bum  in,  101! 

i  Allantoic,  'jy:( 
Alvi'gniat'K  [lump,  454 
Alveoli  of  lunftN  433 

blriicture  of,  433 
I  Amblvopiu,  843 
Aniipfia,  cliami'icrislicH  of,  33 
Ani'i'biiid  movementH,  liiT 
Anelettrotimils,  131 
AnimnI  binly,  (-hemicnl  baneii  of,  1015 
Animal  heat,  041 

diHlribution  of,  IHl 

pniduclion  ()f,  045 

rejliibition   bv   variationii   in  loto^ 

644 
wjLirrts  of,  641 
lem|>erutnre  of  bodv,  043 
Apha;<in,  H23 

complete,  H27 
|>artii(l,  )127 
Apnii'n,  -iW 
Aqueons  buniur,  Stl3 
Area  for  muHtiention,  R14 

l>nMlnction  of  voice,  814 
Kpecfb,  823 
HwalloirinK,  814 
Arteries  ehanjn^  in  calibre  nf,  2(t5 

stniiiiirt'  r)f,  178 
Arterioles,  178 
Awiiew,  417 
AB|iBrogine,  1052 
A«i)hyiiiB,  402 
A.'tiKniali^m.  itDd 
Atropine,  lu'llnn  cif.  im  heart,  262 

im  pnpil.  905 
Aiidilory  jiulicmeniH.  U52 
Anlomnlie  action^  171 
I  ALiti>nintiHin,  irrvgillar,  870 
r  PfKular.  870 

I  Axis^linder,  121 
■  Ax isH.'y Under  proee.*es,  186,  80" 


BILE,  Ml 
acidi.  ;i.>3 
I  formation  of,  508 

action  nf,  on  food,  353 
I         antiseplie  ijnalilies  cif,  'S-'A 
'         charaelen  of,  ;t51 
I         riini[«>sition  nf,  :lol 
I  formation  nf  ninHtitlientx  of.  51)5 

inHnence  on  )icpli<'  ili){L>f<tir>n,  39'i 
I  piKlnenli  of,  :)52,  5il5,  105ti 

',  Cmulin's  te^l  for,  352 

,  rcwriilinn  of,  3(ii> 


^^^loSl^^^^^^^^^^^^iNDex^^^^^^^^^^^^^^B 

l!i)iiwlt>.:i>3 

HUiwt.  roll-  of  i-tniiliiii>iti.  iV9                   ■ 

ttvw  Tor,  3&S 

n-lilioiuxf  "tii,  ti  ill.  (.Vi                 ■ 

l>rtll■lIk«^M'^  x-a 

rvsjiinli-r^                    it,  t'll                  M 

*n-n!<io:i  of,  ^11 

"'11''.*' '"'                     '"  <~onlr»rtU*  S 

miiriibiii,  3f>2,  UM 

•iii~>.  1  1 :                                      ■ 

liilitvnliii,  '^''i.  Wu 

nf  li^or.  M-J                                    1 

Itiiim-iiliir  visiijii.  tC!ll 

vnvoU.  (ii)>llbrr,  ITS                   ^^J 

lllndili'i,  iiiiix'k--  nt,  ■•i* 

Knin.                                               J^H 

-irorl'm'  '•(,  ''iti 

>ltH-iin-  of  •I)(iit  of  mltllMi  andW^I 

Illiiiilim,  Mi 

Bt«v.>n4                                      ^ 
kill)   <|ilnal  nirri.    Imttiliniir  amafl 

blind  ■w.>T,  tiiiiiitc  ui>  •<  vm 

inrtiii'iir.  -   1- 

IIUxkI.  41 

nicnilifaiic* 

mrlBink-  lu'i.l  in.  -MMI 

rRHIllar  ilrr.irii.-«  »•<  ,m>  <t,  r-j 

cliiuiK"-  ill  •[iiiuiUlv  Mr,  "iOl 

aiti-riiii' of,  illMrllnlion  nnri  rhaiwM 

rllcniiiql  (i.>iii|H>«iliiiii  i>f,  Ul) 

S--! 

ritillinu  i>f,  U 

IiUmhI  HIIiIiIt  ■•{,  «t 

>ici  Itmu  ■>f  Inm-iimilni:.  w9 

biifly  luil  in,  -U 

vuUMM  of,  'rj 

bulb  vi.  Tin; 

MqitUFli-*  in,  SS 

6bta>  nj,  74s 

i'ni>Miiiii'tiiiini  III,  4'J 

ifiitral  itniy  iiiniii>r  nt,  74> 

(-nii'l  "r  iiciilrnl  -ulwoil,  i-* 

i^Hn'l>rii"-|>iidl  tliiiil,  '*>^l 

rtTvrl  \'f  "-Kliiiiii  clilori'li?  nil,  -H 

i'hiLiirtr<  ii*  L'TiM'  iiiAltrr  of,  Tl^f 

i-llii'i  <<r  ii'iii|H'niiiirr  i>n,  -17 

(Tniniiwiinil  flhr^v  of,  7I<1 

lilirin  in,  41 

i"iin(i-1)'-n-  •-!  ^itiv   am)    h  IiIiu  a||^l 

filirin  rrnurn)  in.  ''>(> 

^H 

lllirliiiiuv'ii  in.  Ill 

nirjii'"!  ci-nivulntB,  77'-'                ^^| 

in  ftrit'rit^  ■'•!( 

iliiiiilriKMniiM,  77;!                      V 

in  vfiiii,  :^•i 

t^rar  mMU'r  cK,  TTS              1 

ii-iiffili  -ir  tiiw  of,  '1:1 

n>r|ni>  •(rtiiliiin  (if,  "idi                 ^^^M 

IKinnilt-liiiliu  in,  -Ml 

liliri'x,  7TH                         ^^^H 

i>)iuniiiii-  iii.  44 

(-mninl  m-rvAuf,  73<l                    ^^^| 

nii'iclilv  of,  i:i 

oiiibminii',  731                               ^^^| 

■rnini  in.  A'l 

lilirv  <if.  774                                   ^^^1 

■enini-aliiiuiiiri  jn,  -M 

fiiiu-iinio  of,  i*ll5                                    V 

color  of.  <'>4 

tnu-ili*  iii»l  (iiDmlr  niirlH  tt.  TM       1 

briulxiKw  ••r.  line  ii>  rrllLHli')!!  iif 

eny  iimlUT  uf,  74H                                I 
hiiii>I>-;;ii3l  fcalillts  nf.  TW                   1 

lifrlii  iliroiifrli  n.riiiiM-lt^  .'iil 

vrniiiix  mill  iinvriiil.  f )',! 

itiliTiiinlixir  Krnr  ninUor  nf,  7K        ■ 

OiliipixiliKii  III*,  I'-V 

luneiliiiliiiHl  lll>n->»f,  77>'t                     M 

lIUM'Ik  4-Vi 

nnlun.'  unil   rdolkint    of   lllr  t^^U 

iiK*ili"il>-f>ri>htalnln)[.  ViS 

iiiu-li'l  iif,  7lM                             ^^H 

llirlnlitili.  -tiM 

tilliari  iiiii'k-ii4  of,  743                 ^^^M 

fi-niiim  of,  I'H 

o)fiii-  iliiilimiiis  7K                       ^^^M 

lliplhnll  iif  •'•lilalllinx,  4lH 

(HwiiTiot  liiiiiilliH  of.  '(to              ^^^1 

IlHIIllll,   i'U 

]n»U'rii<r  r>.>niri<'  1/.  777                 ^^^| 

iTTalsU  i>r.  4114 

|)yriiriii<lui  Imrl  <if,  77o                    ^^^H 

llntiiiiutol-lli,  4''iT 

i|jlniii'tiiilf  fiiiii-liiiiii  ol.  SUV          ^^^B 

oliuraiioP'  "f.  4-'>T 

pltui-liin- iif.  7-'(l                                          ■ 

nii-ih'Hl  of  uliriiitiinx,  ihT 

r>iii*rfii'inl  pnir  mailer  of,  T62    ^^U 

(fNvtnwojiic  rintum  of.  4SH 

■>ii]H'rwir  ■■!  •f'liH.n'  ilmi-Kili«ii,|^^| 

iiiriclitw  iif  iTTHlnli,  4.'i7 

lnii!l^  fdiiii  ix,r|K>n  iimidrii^tf^^^H 

■iii>ihK<ii'>i;l«l>lTi,  41V4 

^^H 

IMflllwIc-*  <>f.  S'[ 

vi>nuiiH  iimnKvavni  iif,  tIKS       ^^^| 

>vi-nii!;v     miiiilirr    iil',     in     liiiiiinii 

inkllri  tif.  Hi  i                    ^^^^H 

lil™«t,  57  ^ 

ItliK'ii'*  iiaivnliitkin,  B2i1                   j^^^^l 

rliiinu-b'ri'lirs  of.  '>t 

Urundiin.  I.-Ct                                  ^^^M 

iwl.  •inirtupF  'rf.  ■"■« 

■Itiu-iiitv       43->                      ^^^^H 

lurni<>fllo)>ln  in,  o4l 

Broiii4ii<>lc^  Vii                              ^^^^H 

wliiii'.  1,^7 

Nlnu-iiin-  «r,  4%                          ^^^H 

vlln-l  of  Oi-liL-M'iit  BrrntioD  on,  468 

Oiiiilii<'h.  rotuiinu-  uf,  (Wtt                    ^^^1 

Itlntvlrti.  U» 

^^H 

]iliH|Uns  W 

1 

jireiKinv  1'*'^ 

pALAltAIC    liran,   BCtioti   of,  nn   laoH 

■iirvn  from  rnmllil  of  nifalill.  IXP 

quMiiily  of.  It>  iIlMrDiiiiiiin  in  I>'1<.  71 

('*l4riiiMTm^  fi39                                      ■ 

1  X  U  E  X  , 


u>m 


('n|iilliiL'i('S  ITt'i 

limilaliiiii  in,  I'.il',  '.'S'i 

I'niiii  lui-sfiiti'r.'  Ill'  «iiiin':i-|ii}ri  '"li 

lin->siirf  (if  IiIiiihI  in,  I'.HJ 

%i/i'  "f,  177 

-liiinuiliiiii'iir  .siiisis  if^ll 

Sinn-inn-  nf,  17(1 

vi'-Hi-ls  rif  niiwli-,  'Mi 
CiirlKilivilmtt'^,  ]ll'.>,  \m:i 
CurlHinii'  ai-i<l  I'xIiiLtttI,  4'itl.  -170 
(jinliiM-  (■•■nlniftiim,  fi-iiliiri-.-.  nf,  ■.'-"ill 

I'lirvfs,  disi-ii!wiiiii  lit'.  'JIM 

^'1 II nils.  :l:.1) 

fniiii  <]nf!'H  nlnniiicli,  i!21 

iiiiliiil«>,  Ul  1 

plNisi-^  <liiniliim  iif.  '2'li 

tU-ilH',  fLNiliircs  lit',  i'll 

Caniin,  lu'il 
Ciwiii,  :ll.'j,  l(l3i 
Cdl  lnHfy,  Hi;! 
Cells  fill  I'll  III' I  in  I.  I7tt 

i-]iilln-lii>iil.  17U 

piMi't,  -1711 

livniiiiiiliil.  no:! 
i'villr.il   iiiTVciiiB  .■•y<ii'ni,   ViL-iiiiiiiliir    fiinr- 

liims  111',  "27li 
CercU'lUir  Inu-I.  iiiiirw  iif,  7'Ki 
(.Vri-K'lliiiii,  iiir|>iis  ill']  II  lit  1 1  til  111'.  77l! 

fiintrniiis  iif,  ■ili.'i,  Mli7 

(jrjiv  iiijilUT  iif,  WM) 

lii'iol.ip-  >}{.  W2 

Mi|nTiiir  |Hilii'k'  of.  7WI 
t'ervliriil  <tmviiliiti(>ns  iir«i>  nf,  "Hi 
'•f  iIkmIok.  mi 

iHirli'X,  NIK! 

lii-iiii-[ili<Ti-K,  [ilu'inmiciiii  c^liiliiliK!  I>y 
:iniiiiiils  ilf|iriviii  of.  7S4-7'.HI 

"[K'tiitiiiii.-i,  tiiiir  tiiki'ii  nji  liv,  .■i7"i 
Con-liriii,  \-i':  11144 
(.'erfliriw-iiiiiiil  lliiii],  ■'•7'.l 

tllTVl-N   llil 
(Vri'liriitii.  miller  siirfmi'  nr  li:iii<'  nf,  lllll 
Cliiiiitn-?'  nf  liv  ill):  lis-uc,  l>4 
4 'li!iiivt-iiii    iiiiil     l>l^(f^^i    liii'iiiiititi-liiiuirlrr, 

■2\r2 
( 'ht-lllii-iil  i-ll;lilj-l-^  111) 
('lifviif-f^lciki-^  niiiiirniidii,  41il 
(  hiliii,  Id^C! 

( 'li>>U*(iTiii,  li.'i.  ■.i.y2,  IDl-Z 
Oiiili-ii-liii.  lll-'h-i 
I '111  mil  rill,  10:11 
('lliinlii  rvilivii.  '«'>'.> 

tviii|iiitii    iicrvt-,   imiiti'i'  :inil   iirliiui  nf. 
■  :i:t-i 
t'lmniiil  iimt,  "■•■h 
4 'limniiilif  iiln-rnilimi.  1117 
Clivli'.  I'liiinii  iiTs  nf,  4HI 
Chyiiii-,  ;is!i 
Cilijirv  tiinvcnii'iit.  |.'"i4 
rirciiliiriciii,  niUM-.  nf  irt^'Klilnr  livurt-licat. 

■2'.a 

i'iminisiiiii<i.>?<  I li-tt-rti lining  i-liuriii'lrr  nf 

tln»-,  hi:! 
Hli-el-  nf  !ili-ii!i(>l  nil,  "Jllo 
I'Hi'i-l-  •'{  I''"kI  nil.  :i;is 
fii'Iiil,  ll)IHI 


<  iron  till  inn,  liyilniiilir  |iriiiri|il(>  nf,  Ili:> 

iilHiif-mt'  nf  i.'K<'n*isc  nii,  lillli 
CiMi's,  (liHiiniiin,  Slk'i 
(  lurki-.  111] u mils  of,  (IS.'i 
i'oiilsnf  iirlf'rU'f.  1711 

of  vi-iiij,  IMl 
I'lii-lili'ii.  1142 
(nlil,  Hi'iisiilionK  nf,  KTi] 
Ciilnr-bliniliiess  1'2:! 

sonsjuiims,  I'lis 
Co  Inst  run  I,  li^,"! 
( 'oJiijHiKjtinik  nf  liiK',  '-i^tl 

III  IiIihhI,  lill 

nf  gimtric  jiiiiv,  IMK* 

nf  milk,  li'.>4 

of  |jfrx|>innioii,  .'iiil) 

of  «.^ivl^  :Wi 

of  Hiiirviiiu  IkhIv,  (>:iK 

of  iIk'  iinitiinl  IhkIv,  IJ2X 

of  iirini',  '>'2!^ 
Cnniiii'livi'  liiwui',  174 
Ciinsliml  I'lirn-iit,  lU-linii  nf,  l:!S 
I 'onlnictilc  iinwli-^  HHi 

tisswH.  7'.;,  141' 
( 'ontnirlion,  lirfiikin;;.  V2',> 

i(lio-iiiiis('iiliir,  141 

iiiukiiiK,  l:i'.> 

li'timii-.  74 

Hiivi'  of,  5l7,  l-'i^ 
Cnnniiimltil  niovtiiu-iitK,  nincliiiiiTv  nf,  7!KI- 

7ini 
CnnI,  Miiniil,  'i7o 

volitintiul  i»i|iiilws  ill,  KVl 
Cortuii,  .SS7 
Cnniti  uninionii,  ,sti7 
Cnr|>nni  ;n'niriitulu,  772 
Cnr[n>ni  i|ii:nlriin'iiiiii:i,  ftimtioiis  of,  Mi7 
I  oqiiH  iiniiilii,  1^2 

liiti'iiiii.  "N.^ 
Ciir(iii.-«'li's.  1 1  •limit  ivc  iis.-ii(',  174 

ntiiiili(.'r  nf.  in  liiimun  lilnoil,  '>7 

■if  IiIihhI,  5-1 
(  oMi-x.  .Trc'litiil,  S(i:l,  N7I) 

!li-(nlo«y  ni;  SIKl-MW 

ji--yi-|iii-:il  |.rni-t\-**s  in,  S71 
Cnrii,  nrj;:in  nf,  114:! 
I  nrtinil  iin-iis,  rcmnviil  nf.  >21 

motor  ri'fioii.  J-lO-Sl-'i 
< 'nini|>s,  miiH'tilar,  l-'k! 
(■ryMiiliiiu'  lens  Mi2 
Cnrrcnts  nnistunl.  7") 

olit-lmtcinic.  1:12 

iiiiliiiT(l,   7,'"i 

nf  ai'tion,  Mli 

nf  t^.'^l,  llli 
(  iirvi-s  nf  i-ii'liM-.irdino  |irc*iirf.  217 
CnliimiiiiH  M'liKut  ionH,  K.'il 
Cyatin,  llJ."i:l 


|\A>LKLI.S  Iminrv,  7.'> 
I'     lifiitli.  101:1 
m'finiiioii.  ;!'<:i 
l>0)-liililion.  :[7ri 
Ih-|irf«nr  iiiTvi',  2711 
l)i-rniis,  .V)2 


1064 

lVt'('lr>[iDirnt  "f  cmbrvo,  090 

I'f  (.luci-nla,  SM 
|)v\lmi.  UW, 
l>riirDM'.  :hh,  laia 

Diiiboll!-.  oH.'> 

I^DgTMnmnlii.-  cvf,  HUt 

ItUpliraicni  jv,  ii'(v>|iinti>iT  uiiWkln  U4 

Diet,  tiotmnl.  lifil 

Tiii>)ilii.iiti»Mi<  n(.  (bIT 
Dtltitfiiif  ill  h9|nniii.,n  in  wxo^  4H 
Ilixi^li-ili.  ;U)1 
l>ilntntii'ii  vf  iirtcni«,  IN."! 
l>i"|<triL'  ll|•|■l1mlll^  inijWTrrcijoiii-  in,  Wfc*. 

Ea(i'li.'iiii>iii>H  '4114 
Di«fliiirK'-  iif  t-niTity,  N7i> 
r>iiiri-tiiA  tVIA 
i'ivixinii^  [if  oir,  fttn 

*if  'jiiiial  (vini.  677 
thilnii.-Itcyiiioiiil  hey.  T7 
DurlH  i>f  iiiHnininrv  Kt!iliiJ>,  li'M 
Di-.i.i..™,  441,+>(f 


EAR,  WiV 
fiflllcii  nCiH-J 

■liviilriii  I  if.  |i:^ 
KiwlJicliiiin  liiU'.  Uth 

liitvraitl.  -T  lalivrjnili.  Ml 

UKiiiiii'  niiiliiiiriiu  piicrniH.  «t1 

nifHiliriuii-  iif  |{i-i»n(<r.  llj.'t 

mi-iiil-nini  iyiii|«viii.  mil 

iwniliniiiniui  lotivrlntk.  M>'i 

oivaiii.r  ('•■rti, ',11:1 

ni»n>ii>  lulitriiilli  of,  IH7 

■nwlili-  <if.  HIT 

|i[rrlKin|di. 'Mt 

|>lii-*|o].,i!i,';i|  nunininv  ,)f,  |1S9 

*Iii|Hiti<in  niilwlc  ••(.  9^» 

Itniior  lymjBiii  rhwIp  of,  SI" 
Eili-renl  iiu) III !•(>«,  *I72 
Eliuiiii.  Itn-.' 
P.lwlrinil  rhunxv^  118 

"limiili,  .H 
KlninNK'^  nnn-tHiUriiMlilv,  ll:i 
Q(i4n>ii>iiic  furrmt\  Vi'i 

Tariaiir-Ti.  1^  irrilithililv  (hiring,  l-ll 
KlfiJU-Htnri-  aiin^  tneiumt*  uf  ■liilinl.  H^' 
Rlcvvnlli  norvii,  7'ilJ 
Kmlwyii,  tiiirritiim  iif,  siil7 
Knd-|>liiii^  VIA 
KiierBV,  'liH-haifv  .if.  «7IJ 
f^lMTnliiun-  of.  fa* 
iiiK^iiii:  (rf,  AX! 
of  inn'liaiiiinl  mirk.  IHO 
EniD|iili-  |>li(>n'riiivnrL  INM 
K|■t■l■■nlti^  A.'i.1 
Kpjulnltit.  Hit!) 

Kpili-|.tiforiii  i»nv<iUiiin>,  Kls,  ««:i 
K|Ntl.fiiuni  of  ilir  .tmiA,  fanrtwno  of  341) 
PAt>tnrliiiui  iiiln'.  !Hn 
Kiir«i'ni,  JS7 

JCxtiiiliiiiiiii  of  aijuauiiK  rapoT,  WO 
of  rmrlmiir  arid,  <S0, 470 
of  mgnnii-  luallcn,  461 


1SDK3. 


ElllalMKin.  r«ll«ii  of.  1471 

Ksiilnitiuii,  «■( 

HfnnKiii  (iiv,  iia« 

(■llUrr  rrnlinl  of.  K^il 
•tiuk-niiiiiiuiH-,  !i9l 
i-mntrlnifijc,  "UT,  MW 
Ix'tioHiul  tviltni  of,  81*7 
hvjii-niwliri|iir.  dUt 
luivbiiniMiifi  •■/.  liilT 
■iic>VFmMit4  of.  ;i;in 
niavk>  or,  li-tl 
niyiij.jiv  KSW 

fliKnii-iit  ivll.  .rf.  nail' 


CAdAI.  i.,n-,v  T.'hI 
I        loiirw  of,  7.'») 
Fill li>i>i nil  |iil,r^  i(;s.T 
l'|nr:iJiMT>iin,  S4I 

I'uU,  •-i>ui|>lcx  nllr<>i[i-nnu>,  1ii|:( 
ri'Diiutloii  of.  (ll» 
naliin-  ..f.  ill  iiilljinv  liMiir,  fi|t| 
I  (Ifiiiral,  liii^i 

I  llicir  •trriralh^  iukI  alliif^  UKIT 

rfii-f.  :ill.'j 

[j-iiinlc  jnmi-ratiTv  niiiatniliH.  W2 

1' ilir»-Mitli-reul,  15U 

cfli-n-nl,  |.)ll 

■ifn«.rv.  |.)U 

luMM-iifKlrii-lar,  :r7(l 

I  TiHiililnior.  27(1 

nujrur  of,  'S'i 
J'll'Hii.  m  H.niiiig  of  liUni.  1 1 
lil'riiifim-ii.  1)1^2 
1-ic-fc'.  -j.ririK  ttinnniuclrr,  a^O 
I'illd  ni-n,..  7'Vi 

lininriMn  of.  7^0 
I'lmulctiiT,  :RJI 
K.iCiil  dn-iiliiit«n,  I(m«) 
,  F'ltlidc  irf  hiiJr.  .VV.  ^ 

Fwid.  u-tioii  of  Iillo  aiul  ■•nnernOlr  Jnbvl 
(■mnll  iiiiiiiiiit-.  :i!il 
dmiitti'^  ..f.  ill  )ri2v  in|4^iiic  SM 
in  luimili,  :w« 
in  •<iii;ill  ill  till  Itii',  .'tUI 
{||  •(oainclL,  ^1U 
vftvbof  fniiT  iind  rarlH»IiwInH>,i 
•■r  pn'lntin  uis  GSlt 
wJi  ai^nSll 

-•llll^^  :tii| 

I'lnnHi  lit  3(tJ 
ro'iriti  jiiTiv.  7'>l» 

KoiMi  l>i-iui>-|>litni«,  1142  ^^ 

riuicii.uH.1  iiriiviiv.  inttimiiT  oC  nn  ^mJ 
iniriili.-ii>><t»,144 


G.\  T,KX.  it'inn  of.  Xtj 
<Jall-(rinCN  iV^ 
;  (ianfflin,  ^ii|inthDlir,  lilA 
(nuiirilnnic  tio-irlt.  lAJ 
thuiw  in  liIfMiil.  (;ii 


I 


iitutr'ic  nml  inlnliinl  morcmMiu,  niTvoiu 
DKrfciiniuiii  of.  :tS'l 
dlfiatian,  HrrnitwiMwtM  iillwtinK.  :<i:i 

drrtiRMtmcoi   NtI<rCTi^t^   tcmixTn- 
lnM\  :1I4 

KCtion  n(,  on  milk.  :ll-'i 

nil  [itiiifiiK  :mh 
rhiiiiionl  olinntt'lcn  nf.  '.¥1' 
fcirinuliiin  or  Irrr  ite'ui  ••(.  'M> 
nuiiirr  lit  iliv  u'lion  ■•f.  't[4 
nx-rvliiin  I'f.  :t)T 

U«lMui,  \74.  1031 

Otoanilvp  <in(*ni^  fenul«v  Wt 

ShTximl  nnnuimv  uf,  M2 
.     >i' 

Krtivmt  iiLtlurc  iif.  HiH 

nf  lEninnrr.  ^>7i 

>if  l.k'lHckiiliii,  :i7'i 
(llJMOIl'!!  calMilp,  olUl 
<iloUn.  WH 

(iUiiDiTuli  iif  Iriilni-y,  fll7 

(ilalll".  mirninmK  ■>(,  ITl 

wilk-L1iri|C  <rf,  *j7. 

liliitiii.  KKIl 
niv.i'riii.  VHO 
lllvdii,  HIM 

((iTmiii'ti,  iin>.  ut:i.  milt 

■■iKnu-lm  'if,  STIl 

iviiivi-t>i»ii  at,  )bi>i  Aiiinr  Inr  llivr.  473 

in  nmx'li'.  'M 

ill  jtLirvni^  A^4 

ii*-*  nf.  ill  tivcr,  oSI 
(imi'lin''  lr<it  fur  ink;  3A2 
lioll,  (i>l<i>iiri<'  <it,  li>*lt, 
tinnlinn  r<illioli-.  1)^7 
liny  inallrr.  Iflll 
C  iTOTp'"  bnliiTc,  7 A 
(luunin.  I<ir>l 

limlili-n''  niniiiiiiKurv,  "10 
tii»nsl<>rr  liiilU,  U"m 

iniicHU'i  iiiriiitirnnc.  |ihTiiioIi>g!cBl  anM- 
omv  <ii,  IL'iil 


H.EM  \t  \-n  'M  ^^•HK  ..r  «Jow,rr«.  S!« 
ll'rml■ll^llllllm■•l<'^,  Vnlkiiiiiiiri'p,  AN) 
flmnatai-lioiiirti-r.  OixitYnu  iiul   Likrivl'*. 

a)ii 

himntiii,  'J64  , 

Ilnntii.  4tA  ' 

IlapiiKiiclobin,  4^7  i 

In  r*d  I)lwKlH«nni*'I«^  M 
Ikin.AM 

ttruiiax.  ivnalUinii  of,  HAO 
Heart.  'JOK 
^  -ImM,  uigmoniatina  nr.  Sill 

■  flovOTnuMsit  uf,  hv  tbo  iwrviMU  *r»- 

■  tnn.  ^1 

H  n-lk-i  ifiliiliilinn  o(^  S&i 

H  <«nliac  tyfli:  oj,  2U7 
H  koimmI  and  iwnbniir,  31'> 

K  viMiige  of  form  of,  SOU 


I 


Utwrt,  ilumiim  nf  tlir  •c*«f>l  phwo*  at  die 
ranllftr  t^yi-lp.  '"H 
viiiliHiiriliiu;  (iroMire, 'Jt3 

•ueibnita  ot  dclcrmining, 
:!U 
llr-lxmixl  nf.  212 

Bngiia  of,  ^-Vt 
ulnltif^T  nf.  'i'll 
mnliui-  miwuliU'  liaoe,  $11 
nifijiniirv  oT  nutmmwIJMi,  34J 

illl)iill>r  [if,  :!11 

iiillumuw  rqpilallnjc  lient  of,  3(1.1 

lUKln  tvtMt  mnirring  in  vi-nlridf  dtir- 

inft  *  bMU,  i2» 
in0Uiv«  (itvnutv.  nsiiuvand  nam  at 

nrrvo  <)f.  2Kt 

iionuul  lirut  iif.  'Jtxt 

iinuli<i!>  nf,  'i47 
ik-vi'l'tgiiurill  i>f,  S45 

iwyiiUliun  uf  kill  of,  -J-lfl 

Mcwul  (ounil  nf,  'iVi 

Mundoof.  :zl:! 

iniiiiniarv  uf  »vifiil»  om^iiinilnK  ■  (imt, 

vnlvBi  i>f,  '207 
vviilririiliir  nvrtiili",  S*W 
vjxihli'  iii'avTiK'oU  of,  l£l)6 
wurk  <l'iiii-  liy  "i'ii 

IICUI.  •t'IIMIli<-ll>  of,   S.M 

lldiiihotii'*  iirniiietii)i-"i  for  iH|ii(ilixIng  ili« 
make  niiij  liriak  kliookis  m| 

|lI)llk<~>Hlii|iv.  IHMI 

llFiiiiiiml>lvi>|iiu.S'l-l 
lli-uiinnriiiui.  t-IH 
llr'rikijiiii>|niji.  K|3 
llLiriii'piii.  Sirl 
Hfni.-'-  .Ixnilli.  ISS.  IM 

llik-riinit-m.  ittl 
lIi|>|)iiniiD|al  Inbiilc.  H4!l 
Ilipgiiirii^  nriil.  r'liniuiliiiii  iif.  54S 
llipt-'Iiiriiulin,  IDT 
lloni'lcr,  |i:l-l 

llaniui)  bnun,  noaiiimclatiuv  of  ill*  (orflwD 
of.  H34 

OVUSI,  W47 

Ilvnioid  RiMiibrsno  of  rrr,  HW 
llvdniUllruhli).  lUOH     ' 
lly(«rii<i'a,  4S7 
Ityimnlic  (-liuaw,  SSI 
I  ly  I H  i)[kHUil  npi^'p,  7-ID 
(••iiiw  ■•f.  74U 
llri>oiamliin.  K/iO 


IMAfiK  fnrnialion  of,  KM 
liii)wir<T-i  -jiifwli.  Km . 
liupnTifiuiiiiin.  twi 
liniiiilM'.  ni'miiit,  124 
Iwlknn,  IiKVj 
Indifo,  lajli 
Inilai  SSU.  IIMd 

IndiKtiAU  will.  7T-71» 
InlliUBinalion.  iihcinjiiiiein  of,  SHI 
InfmuUIialB  c>f  lll^|.■^  -133 
tfniiiirc  nt,  iH 


^^^IW^^^^^^^^^^^^rjCDBX^^^^^^^^^^^^^^H 

InhiUtl-iii,  fiwliiri*'  »r,  2^1 

].rrljiih-(ii^  Iwilrry.  TA                                 1 

••t  iiy'if^  hcon  In  ^linulnliDB  ut  'rvtctif 

lA-Ud-cvlhirsiia,  I'liarsTfrrUod    t^  ilMnM 

m-rvi-,  :;.'H 

of  whil«>  ci>rj                                                    fl 

InliilHlcin'  iivrvi'*,  I'l 

l.lfr.  |>liaK*>('1.                                                   J 

Iniijtvii.  I-I' 

l.itniniciiliim  mil  If-.  1.  ■                     ^^^| 

IniMil.  WXi 

l.iiiili,  iiHiitsiidil*  cf,  SSt                     ^^^M 

lii»|>initi>'ii.  444 

^^H 

liiTi'rtiinliil  miii'lcf-  in  nv)i!ral)iiR.  41T 

hill!  aijiilliirins  i'tl                     ^^^M 

Int<'rrilirillLir>iiUlftiiix>,  I<'l 

'illHIK  -ViN                                 ^^^1 

Itiualliiiil  iti((i^li(i|i,  :|91 

•iriii'liiri'                                ^^^1 

Iiit(T>lIiic,  cluxil- "C  ''SMI 

(ilUfllll'  lIllMlIc,  -JllO                              ^^H 

Innfiv  3T4 

IviBpliBlin  I'r,  '>7Z                       ^^H 

kfiivkl  fiMliinw  of,  374 

tirrvivi  of.  ■%H>'i                                ^^^1 

niiiti'-ili  mtriiibnini!  of.  3Qfl 

■iTiiLiiiTi-  i>r.  'Ml                           ^^^M 

miiJL  3lVi 

(^•k'k                                ^^H 

-IMvlul  fraltirtw'if,  :iiL*> 

l.tiltnK  Ih'Iv,  ttiHli'  of,  13                   ^^^1 

iilniL-liirv  (if,  3<lil 

LiijmI,  iiilliiciMv  "^  t:lV                        ^^H 

IriisSMa 

I^oIkv  ft  tiniin,  732                          ^^H 

lrT)ulin(I»ii,(IJT 

l.'ibiitn' (if  luiitE>,  433                          ^^^1 

Lunii,  lOi^:!                                          ^^M 

I.nilinL-'H  kTiiuifni|>li.  ISO                  ^^H 

].\<t)[l'S  .in-iii1imti(\  S91 
V     Jniindicv.  -'itl^ 

■liiiiriii^r.  :MI                                     ^^^1 

Luiiirs  4:11                                            ^^H 

JuiiT,  ipintric  3<iT 

^H 

ull'in  oil  nrulcEil*,  :tmi 
■niUcinl.  !»» 

HU'ln-imii-.  W                             ^^H 

'■r.  4M'                            ^^H 

rnnij'witioii  of,  308 
|wiii-miiii',  Xi* 

funcii{in  cf,  4^1                            ^^^1 

infuiuiiiiiiiii  nt.  i:a                ^^M 

nviiiiii  iiti  fixxl-^iilli^  Xn'i 

lyniphnlio-  <>i,  437                       ^^^| 

DFrrt"  of,  4;t«                                ^^B 

pmHuiT  <-xt'iuil  in  limiililng.  tin     ■ 

yATELWTUiCrUNl'S;  1»1 

Mnirliin'  ••{  mniiiDiiiliaii,  433             1 

IjiwplMiic  kUiuIis  sinuiiiiv  of,  ¥A        m 

KMifj",  ■■II 

tTMmi,  :u*i;                           ^^B 

Ktrri'in.  jivnuuiiU  of,  SI5 

i[liinii-nili  cif,  .".17 

ru*«K  •inii.-iii[v  '4.  l&i              ^^^M 

Ljinplinil<>,  KfiKin  of,  :ny!(               ^^H 

I4riii)ili.(ii|'il1»rii'>s  3»T 

Mnll'ichr.  {ivnimic)  nf.  alS 

i'liHr»i-t<-i>  cif,  41 W 

MiU]'i|{hi<ui  miMil«v  'MA 

>'bi-lliii'Hl  i"nill|">  i-J'  '■  ■  '     '"" 

iii-rvi--  ..r,  .'St 

IkhUI^  ■Itiii-liiT'                                  Us 

riinicriirv  i-f.  >'i|l 

iiiicnM'oiiit.- dui. 

lulilil)  iirintrvri,  .M2 

uiovcmMiu  of,  411 

viM.il]nr  nr ran t;v limit*  of.  'iSl 

viiMi-itilnior  ni-ri'<i  of.  o^i 

vnwi-tiiri'-irii'tor  iirrvo  of.  AM 

UACIMCTII'  iiiti-nu|<h!r,  SI;  \tt 

viwiiivl'>r  luvrhnniHniH  of,  fiilD 

Kim—wlir.  fl^:^ 

t 

Krtntiii.  Ml',  tl)4V 

i"-^ 1             .H 

Kmiiiiiin.  t<>-l'.i 

WIIH1I.WW              ^H 

K} Iiic-Knil'li,  IVO 

({wmnlOMM,  BW          ^^H 

l.ii(1wI|r'>S  11)0 

iwUcka.  084 

lunirs  ■JtoiRinM.  VH 

v»>  ilcd'n-ii-,  IWt 

I  AfTEAIJ*.  :Wfi 

Li     Lninliiu'  in  a  liunlrntd  laiu^  )*V:! 

rmirilln  K-niiiLrilt^v  V^l 

Mnli.iihl             !    Mto 

Idpdanin.  t<KJS 

r.5III 

lutO  inuvlinc,  ^74 

Ualln-r,        : 

iiKivcmtmb  «(  SKt 

Hatiiniarv  jilnnils  ilA) 

Larjrni.  KIM 

I'liiiiiliv-  rxy-iirHnc  !n  «23 

ruiilii)!**-  i>f.  W» 

nlniiiiii  ti'  I                  •ton,  ItC 

nvilv  i>f,  U70 

•tvmlliiii  >" 

miwdi*  of.  070 

nlrtii-lim'.  i>'.'<>                          ^^^t 

I*1)yi4i>l(i|j;liiil  Bnniuni7  of,  MS 

Muioiiicur.  nii'ii'iity,  l^V                  ^^^^ 

Twnt  oinU,  1170 

vnioiK  ly(^  lUi                                ^^H 

Ijili-nl  i*ric"),  ^7 

Uan-v'n  inuiljoiir  with  iBnllor  aMintL  SIM 

l.«<-illiin,  \-i'\  1143 

• 

"■"■"        J 

11                                                                                               .*■ 

.       J 

IN'DEX, 


1067 


HRxiniiini  manoiuentiT  «f  (ioltz  anil  Guule, 

214 
Maiwell'H  niflhod  of   fiwing  oilor  mnm- 

M«'hniii)-mH,  dioptric,  N!'4 

iir  uiuiniiiiiHlHliiin,  >-'JS 

locomotor,  !li7 
Medulla,  IT2 
McDibrann  lynipnnl,  Wi 

propria,  !7))  i 

Memhrant  nf  KeiHHiitr,  '.W-i 
Menstniaiion,  US" 

Mercurial  gnu-piimp,  LikIwi^'h.  ini  ', 

Metalailisni.  ^nerul  reiihircx  of,  tl-~i2 

intiiience  o(  nerves  on,  KST 
MetabolileM,  nilro^noiiH,  KMii  I 

Mflaniere,  npural,  1110  i 

Methipiiiogliilnn,  4(i4  j 

Movnerl'd  rommiwure,  "40 
Mii-roorgaiiismis   atlioil   of   In   iilinienlan' 

canal.  SM 
Micturition,  54K 

invoUmtarj-,  550 

nervoiiw  niechanlwrn  of,  -3411 

vutunlnrv,  '>M  ' 

Middle  ear,  tHI) 
Milk,  human,  ti23  ' 

cotupoiiiiion  of,  t!'24 

constilucntH  of,  tiXi 

quantity  sccrelcil,  Ii24  1 

recretion  of,  (ii)  i 

miear,  l(l'i4 
Jlillon  »  reaReni,  4.1 
Morse  key,  77 
ilotor  area,  tliaracteriHticn  of,  CtW 

for   left,   arm,   unci    fact   in   ninn. 
uviiion  and  relative  extent  iif, 

Movenienln  of  heart,  20ti 
of  limbx,  »-2V 
-killed,  WO 
Mucin,  ■M-2,  I(K«) 

Mncoun  eliind,  i'han)!:e»  in  during  ^ec^etion, 
34-J 
Rlands,  Si') 
MuH'H-  volitantei",  'JW 
MuK'le  and  nerve,  decree  of  irritabiliiv  of, 
1411 
experiment"  wirli,  7S 
lilienomena  of,  7)i 
eart;  00 

eliemislrv  of,  104 
(imlniclions,  simple,  H2 
i-nrrent,",  li;! 
ctirve,  M 

double,  !10 

from    tlic    gantrociieniiii.''    of    ibe 

froe,  f-i 
ninBle   indticlion   ebork    repented  ' 
rn|.idlv,  yi,ii:; 
i-lowiy,  111 
dead,  10>  ' 

dnrinK    coniriidion,    clian^'^    lakintr . 

Jlnee  in,  !M 
-plate"  of,  yii 
energy  of,  147 


Mnwle  fibre*,  elemonlary,  94 

microscopic  I'liangeis  102 

-nerve  preimralion,  7->,  IHO 
u*  a  mucbine,  I'l-i 

plasma,  10« 

sarloritis  of  frop,  U7 

size  and  form  of,  140 

slnictiire  of,  Vi 

>iibi.tnnn',  striated,  HI) 

under  ptitarized  ligbt,  10-{ 
Mnscniar  and  nervous  acliun,  nature  of,  146 
irretobilily,  7;( 

contraction,  single,  74 
simple,  74 

fibre  cells  from  human  arteries  160 
structure  of,  9!l 

irritability,  74 

sense,  9*Hi 

stibstanre,  striated,  It-i 

lisj.»c,  plain,  lAI 
iinstrialeil,  149 
Myoglolmlin,  107 
Myogriiph.  pendulum,  8li 

sprinjr,  Mii 
Myosin,  100,  1023 
Slyosinogen.  107 


NASAL  ri>s«i,  rifrht, '.(-14 
foMP,  9.')3 
plivKiulogii-al  anutimiy  of,  tl.').') 
Xerve  and  muscle,  electric  currents  of,  114 
cells,  Kroupint;  of,  fiM2 
of  spinal  i^ord.  KiT 
variations  in,  tWti 
(.entri',  I  IS 
cbemistry  of.  12.'i 
eighth  or  auditory,  "-A 
idevenlb  or  splnid  :ic\'es?ory,  7.'kO 
endings  in  striatetl  muscular  Kbrea,  123 
tibre,  niediillated.  ILO 
fibres  in  retina,  conmi'tions  of,  81H 
fifth  or  triceminal,  7.>) 
fourth  or  lr<H'hlcar.  7-V.I 
ninth  or  glosso-pharvngual,  750 
roots,  cimneclions  of,  1191 
seventh  or  fiiiial,  7-")4 
sixili  or  nlnhuens,  7o4 
structure  of,  UK 
tenth  or  vngus,  7.".0 
tetanixuliim  of,  V27 
Ihinl  or  oeubi-moior,  7-"i9 
iwclflh  or  hypoglo!*al,  74S 
tuh(.s,  hunmn,  I'M 
Nerves,  ilej^i^nenition  of,  141 
electric  iiirrcnts  in,  127 
Servotis  itiipulse,  I'-IH 

ebangen  in  nerve  during  passage 

of,  UK 
meusuremenl  of  velocity  of,  88 
svsttni,  ceniriil,  Itlil 
tissues,  general  fealureti  of,  159 
Xeurin,  12ij,  1044 
Xeurcikeruliii,  122,  12(1 
Nicol  prism,  102 
XilrogeuoHs  melidsdisni,  KVi 


^^^^^^^OTW^^^^^^^^^^^^INDSX^^^^^^^^^^^^^^B 

^^^m              Nod»  of  Rniiricr,  119 

Pnwiri'  la  MplIUri«s  IVi              ^^^M 

^^^^^         Nn<-leiii, 

Prmlirct*  nf  iliscMinn.  (viiirHF  l«k«<i  M^^l 

^)^H 

^^^^^^^          ACTIPITAI.  rvifioii,  |ii«niinmc«  of  nu- 
^^^H                \J    cinir  wlU  ill.  Wi 

In  |>r«ivi>)<  <::i 

bjr  mg^r.  4ti 

^^^H                  ttculiir  iinvini.  tUS 

\n  tiairr  luul  mI*s  4!ff 

^^^H                            <F<I('II1B. 

PrvmlAIf  eUiwI.  II>4-1' 

^^^H                 Ov«ipliiii;iii.  ^'I<> 

Pmuxon,  Ii\  Km 

ppotflil  Ikh1)<-.  chuMien  «f  ilw  nxm  k< 

^^^^1                         •niii-i'mi-nN  nf,  !IT1> 

^^^H                             BIU*rli« 

IKiriiuii.  :iiW 

^^^^P                         ocn'riu*  «■  i|)lt-  or.  XSl 

I'rutcids  I'il" 

dimllimlloii  i<f.  StS 

^^H               Olotii. 

cnivri'  ,■     !    !■   "■■ 

^^^H                  UlfiiKli>ry  luiiiMiK  iiit^ibniov.  i^l*  ot,  M4 

ikti"!!!               ■  li*  iJiLtt-Mion,  IOS> 

^^^^H                         viiMliiins 

I^Tiur^l  i.'i>.i""<ii'>n  vf,  14 
xan(biii>roI(Mo  tcA  fvr,  1>S 

^^^^P               On<yitrrji|>li. 

^^^^H 

I'mtoiilMn.  3^1  _ 
P>wa<lo|H>iliii,  1.S7 

^^^^B                Ojiiic  ntijinlioii.  Ml 

^^^B                        ihnlaiTllK 

I'in-rliiral  [•Mcv*<i~i,  liiimliuii  nf,  .174 

^^^^K               Urgonic  luiiili-r,  i-ilmtaiiim  of,  4%l 

lli'iiiaitin.  X.H.  ir,\                             H 

^^^^f           Otiiiuiiior 

Pllltl  t%S   HIlJlVIl,    '•'*II                                               ^^^H 

^^^^                       irf  ri-|>riH)iii'iioii,  Wl 

■                           Ovarii'^  IlKl 

■iiiicriilii\  'SIA                                ^^^B 

^^^^^^          Ociiiii.  '/^T 

kntiKTMic,  ZM                               ^^H 

^^^^^H 

iiii-[>i<h1-  ••{  rx-ivinlliiK,  'JSO           ^^^^ 

^^^^^^^^f 

^^^B 

^               n.XI.MlTIN.  UiSii 
^^H                  I      l'lm<-tl.■n^  IVl't 

I'lilM-Tiin-i'.  i'hnra.t«'r«  iif,  :nl 

I'iil><VH:iirt(-i  (ii-i-rilHil  liv  tiiliriniioxnpb 

^^^^B                      cliiuiii-i  ill.  iliiriiia  «wnlt"n.  :((<) 

Itvi-p^  3111 

^^^H                          i.r  <!•>£.  >n-ilon  of,  :i:;i) 

i^ll•■■-l^lU'inx  rnxri  no  urlllk'ul  ihinIcL  91 

^^^H                                iir  rnU>iT, 

frviiii  mnji  id  uurn  at  tiMtlhr  nt 

^^^B                                 ■•Iniriiin- 

Stl 

^^^^^^^^         PUnrrvuiio  jiiirv,  Il'>4 

PilW-nnvc,  ailiiiT>»lli',  V*li*F>  oC  "iW 

^^^^^^^ft                                          1111  (»[•  niiiJ  vlnrvb,  3-'>7 

I'll  nihri'i  of,  olnog  lh«  BTMtW  (IK 

^^^^^^^g                                    nil  r(>iHl-*IutK>.  ^Vi 

i;;w 

^^^^^^^                         i-linntrlvrn  of.  %i'l 

.licn.ll.-.  ii.\ 

^^^^B                                 HicrFiiiis  tif,  'iy.l 

raiiw  nf.  2H'> 

^^^H                 Pa|illlir.  rimiinvnllRbe',  V^^ 

fcjiiiirri  <.r,  39u                      ^^^1 

^^^^H                         fillucifi)riii. 

]-i.iCrli                                     ^^H 

^^^1                 Panutloliiilin.  IIIJI 

|.nHliopilir,  ^9                     ^^H 

^^^^1                            In  iht'  rlollinjc  <if  IiI'khI.  W 

v*l'»-ii>-  iif.  'JXt                      ^^H 

^^^^B                 I'anilixii.  crci'rol.  Xi'l 

Pnpll,  mi.vv.T.cnu  of,  VOI                     ^^^H 

^^^^H                  l'Bni|H-f>l'>iii>. 

nvM'i-i  ri.iFniinii.  110:2                  ^^^H 

^^^^H                 Ptmiiiil  (Utiil.  ni-miit*  nm*llltiu<in  of,  !t3> 

I^ukini".  «<|]>  ..f.  MM                          ^^B 
Piiiklni-'-  riuun-*.  IM'»,  Oin                ^^H 

^^^H 

^^^^H                  IViiiliiliim  inyivrapli.  H.^ 

Pvlnriv  cUiii)-,  ;l£t                               ^^B 

^^^^1                  [V|>i--^iii>ii>i  fiHHl,  3i0 

rvniiii'liil  iilU  >"3                             ^ 

^^B                  IV-flnn.'.          1(i:U 

pVlVtin,  'M'l 

^^H                  IVpiin.       1 

I'vrifiiriii  )caii;;l).uiknrrT«4«1l,  atnirtulB 

^^^^1                 pFrMn>'!i'n\  |<^ivn1  i*n>i1illltr  and  tartlle. 

\nn 

^^^B 

1(.W.  sil» 

^^^B                      m-Klitifil. 

^^^H                  Ppri^Mldr  lU'ivi^iciils  3iH 
^^^^1                 PtTiTwi-uUr  IvDiphatki^  ifK4 

AUAIlHUiEMISAL  Iwdi<^  772 
\J    (Juaiililv  lit   •(|iii<ou*  ra]H>r  rdufa 
4oO 
of  hlnod,  71 

mudo  of  aMlnalliui.  71 

^^^^B               Pi>r"{>jm(t'<ri, 

^^^^P                    pFllfnhnfrr'i  tril  ^r  We  alU,  VrS 

^^^^B                 rpvcr''  iinii'lwr^  lOI 

^^^^1                   Pliv«H|(|[iniiii-,  BrlloD  ci 'fO  pipll,  WU 

^^^H                 Piliiilan-  txicty.  ttlft 

^^^^1                 I'liumiap,  iu  rlntling  of  Mooit,  49 

of  inrbotiir  nriil  cil.al»L  4G<> 
<if  iircanlc  nuilarrefiliBlol,  451 
Qnnlliv  of  nanJ,  9tH                       ^^ 

^^^^1                 Foil-  Vnti'lii. 

^^^H 

^^^^B                                 Kniv  matin'  of. 

nAXVIKR-Snoa*.  IIU                  ^^B 
ll     IU|<iililT  of  nrcaUlioa,  ISW              ■ 

^^^^B                  I^ulrri«^  mliaiui  of  ■inaal  roni,  677 
^^^H                Pmuirvs  srtiiriii],  I3e 

.,_.    J 

r 

-■ 

IN'DEX. 


1069 


Bapidily  of  rimilation  in  veinH,  203 

of  i'lotting  of  hlood,  431 
Readion  of  urine,  H'lS 
Bectiim,  nrurture  of,  3T5 
Bed-blind,  ^23 

blood-corpiiseles,  54 

counting  of,  08 

a|>])ornlii«  for  tlie,  -18 
diameler  of,  o4 
ili8inlcgralicin  of,  50 
number  cjf,  57 
slmpe  of,  55 
clnu'liire  of,  51 
iiludv  of,  54 
ninrrow  in  bonv,  u  Kuurce  of  red  cor- 
pviM'les,  00 
Bi^llex  uciionii,  KiK 

nalurc  of,  I(i8 
of  i^iiinn!  mrd,  ill 
inliiliition,  2>5T 
fiefnirtion,  MI4 
KcGiilulion  of  heal,  <J-I4 
BciN-nvr,  niinilinine  of,  8-W 
Rpniok'N  ^iiii^lion,  '2H 
Kennin,  ;il(> 
Keprodiii'iiiin,  VUl 

coqius  liileuni,  1*88 

of  nienwtmalion,  iliHti 
of  pregnancy,  WHS 
develiipmeni  of  embryo,  Wl 
allanloip,  '.Hit 
pliiK'nia,  W'> 
ir^mtnlaliiin  of  ovnni  in, 

vari'iilar  aren,  Wi 
(imnlian  follii'lf  in,  ;if>T 
imi'tefiiialion  of  oiide,  VM 
mtnpfriiHliiiii,  it!-" 
iirpnns  of,  !>2 

Fallopiuii  xui-eK.  iit;i 

mall',  '.'Mi 

ovuricK,  'Jt:i 

vagina,  1182 
ovnie  in,  !ll  0 
ovum  in,  UW~ 
siicrDiatozoa  in,  ^1(1 
Hi'Kpitution,  431 

abforptiiin  iifosvgcn  in,  4(iT 
apmia  in,  410 

iipporHliL!!  for  tuliinK  ttacing>i,  442 
an|)liysia  in,  -!41,  4'.''2 

plicnnnu'na  of,  4'.r3 
carbonic  acid  eihaled,  nmouni  of,  450 
chanKcn  of  air  in.  Hi) 
Cheyni-f'^lokc^,  4{U 
complioitniul  air  in,  43!) 
dyspnii'a  in,  441,  487 
cHccl  of  lirtalhinK  foreign  gate*,  484 

of   chanfiKi   m   atniOKpheric  pres- 
sure, 41)5 

of  mutculsr  ejerci>i'  on,  489 
elhalalion  of  aiiiieotm  vapor,  451) 

of  csrlHinic  acid,  4>JU,  470 

of  orgunic  maltens  451 
expiraiion,  448 


!  Bet^piraiion,  expired  air,  impurities  of,  451 
'  nuliire  of,  450 

tcmpemmre  of,  449 
'  facial  and  laryngeul,  44!) 

pnphic  rcfordw  of  niovementu  of,  441 
influence  of  vagu.i  nerveK  on,  478 
inspiration,  444 
labored  inepiralion,  447 
niodilieil  movemcnlB  of,  509 
I  cougliing,  509 

cryinfT,  510 
hiwimph,  ij09 
I  laughing,  510 

I  !<igliinK,  50l> 

I  >tibl>ing,  S09 

i-nteiing,  509 
1  yawning,  .'lOy 

movement"  "f  diapbragm,  44o 
of  expiration,  448 
of  inFjiiraiion,  444 
milnle^  of,  475 
nervous  nii-chanipm  of,  475 
nnniber  of,  441 
relation"  of  riTpiralory  Kysltm  (o  Tji;- 

cular  and  oilier  systems,  4110 
residtial  air  in,  439 
rills  in.  action  of.  4411 
I  funi-lion  iif.  No 

Miitionary  air  in,  4^18 
lidiil  nir  in,  43.S 
vipible  movtniinis  in,  444 
Ee^pirlllclly  lenlre.  47(i 
cban>;e"  in  bicr  d,  4*il 
in  tlic  lip^iies,  471 
nndnlalii  ns  ^■<'^ 
Bete  mu^o^lnu,  ■"j-i^t 
Keiiciiliim  of  fpltiii,  5U1 
Betina,  ^i.0 

connective  lipfue  of,  t-'Jl 
inner  Mirl'iu-c  of,  8(^2 
niugnitled  verlical  nclir.n  of,  >■'.  "J 
of  man,  icd  and  lone  fri  ui,  ^91 
pbdlo-ilicmislry  of,  1)11 
Bibs,  action  of,  in  retpiralion,  44G 
liinctirn  [  f,  in  rc^piraticn,  443 
Bigor  mortis,  1tl4 
Bitler-Valli  law,  141 
Bods  of  (oni,  '.143 

Kolamlo,  piibj-lantia  gelatinofa  of,  fi>  1 
ml  ctilc  of,  74") 


CAI  EAL  nerves  of  dog,  lfi2 
l"    Valine  malterf  in  blood,  69 
f-alivB,  ;Hi2 

action  of,  on  starch,  303 
cbaracIerN  of  mind,  306 
of  parotid,  307 
of  publingual,  307 
of  tnbmaiillnr}',  307 
chemical  eharactertt  of,  302 
composition  of,  302 
nature  uf  amyloliiic  action  of,  305 
secretion  of,  by  lueanu  of  chorda  tim- 
pani neri'e,  333 
Salivary  g  I  amis,  324 


^^^^^^lOTf^^^^^^^^^^^tNBEX^^^^^^^^^^^^H 

^^^^^^^B           }|Sslivirj'  flsiiil's  Bi-iicnl  >)nii-lurp  of,  SH 

SiiwU.  H-nHiiiAiw  of.  M7                   ^^1 

^^^^^^1                           n<<tTiiii4  •i]|i|itr  of,  Si^ 

S'.n|».  I»I0                                       ^H 
Siiliiiiry  follii-liw.  luS                               ■ 

^             Sall>>  t>r 

^^^V                  }<ii»i>>nni.  i-flniln;^-of,  M(l 

.Sinuiii-  ftnil  i>|<Uiicliolc  B«rv«i^  IHI          I 

■                             Sfirlin,  1ii:.<i 

Si'inint'rrins,  vc41uw  mmi  of,  (M*.'             1 

SnxlnnTiitmiil.  iM.1 

SoiijiiL  '-'(H                                                ■ 

rrrtilmli,  'M:* 

[au-h  »r.  Vf^                                  ^^^ 

Srliviiicr'*  t'\|ii*riDii.'i)l.  iliajcnuii  iiC  ^^^ 

miu1il>  or.  V4'(                              ^H 
RotlDili  ■>f  ili«  linin,  313                    ^H 

Siililvtnm,  fJiijil  i-r.  S-"* 

i<iiintic  oprtr  nf  iiiiui,  1  lU 

S|M>ci£r  );niiilT  irf  nrims  A34 

nl'  nililiii,  iM-rrip-ilhfv  froin,  !!!■■ 

S]>wtniHii|>ii'  iuiii1v>i>  ■■(  hirllxiicliJilK  4) 

Stk'rolif  C'Bt,  WW 

Si^-wli.  v:4 

HttbiiccDiL-*  kIiuuIvi  ""(l 

Btvn>  tor,  KSH 

Kn-rrti'm,  i;i-n'Tnl  nniun-nf,  !H-S 

IliitHTfnI.  'Tili 

ii.iKirc  <■{  iiii-  ni-i  "f.  ;Mr 

(■BUiol  W  Iwllwr  Jij^nn.  R37 

!4cttim-ii:iiiiim  'if  miiiu,  OTI 

iiiick.  ss: 

S^iiiviixniinr  cniinla  '>13 

S|H.-riiiii|iiUxi.  WHi 

Si-iiiitinl  llilM.  KH" 

S]>)ii-riml  nU>rnit(»n.  VOU                     ^^ 

Sa-iiiinirrnoH  riiliulMv  BW 

Hpli.Vi,-ni<>((nipli.  t>iiil|;<raitlV  227         ^^H 

Svii4iT!'>n,  W-* 

ilnn-y'-i.  :r;7                                   ^^H 

Scti'Aiii'ii-.  iiii.liturv.  W^ 

8i>iiuil  iMvvmirt'  nerve,  iM                ^^^M 

■■iitiini'viii',  "I'tl 

n.nl  171                                        ^H 

ili-linrllriil  nl)<l  fiiMiKi  iif.  I<IS 

unu-r>>-Ul(Tal    iMvnJimc  M^H 

of  iiilil.  S.M 

:uu                                 ■ 

.if  .'(.I'.r.  HI" 

ii>iH-ni)in)t  inwt>  nf.  AMI                1 

priiiinrr.  yaa 

mill 'Ilia  ill-  itriloiH  of,  734             I 

oT  lifiiriiiii.  H.'ifl 

cciilnl  mnni  i>f,  ltT7,  iMll           M 

.)(  Ii.-i.t.  J*".l 

n-rvU'lliir  Iran,  XlK               ^H 

irf  |ip»«lni,  HftI 

C"liimn>  tii   RiiHwIi,  IHUI     ^^H 

llf  VUK'II.  "i' 

of  1  Inrk.  f.V.                     ^ 

nf  in-'lt-.  "(V) 

llf  (iflll,  IWI 

of  KrlllllfniUKV,  >*->l.  VSi 

niRinlcihviif  rrflpx  mnvvMnail 

7  il-7»l 

rvlnlinii  III,  t»  «tiiniilu.\  fllS 

ninm  nf.  (t7T 

■I<-ci-n>liiiK  inrO  u^  (US 

fi-iDiiiv  llf.  I'-iM 

viMlnl.  93*1.  IK)* 

liMiins  of.  ITA 

S!U*r.  Tiiiii'iilsr.  '.'■'•li 

ici-Uiiit'iii--  MitHtMicp  nf  Btthd 

Scnuorr  imgiiil-vs  WH 

(iNl 

p<iTrm"  iM vilify  -I'W 

(rrav  ii]»lirr.  nxiiif  nl.  TWIi  TifV 

fliiltl.  rlii-niliiil  Hianu1«r  nf,  410 

-trui-uirp  <)f.  HTfe 

Srniiii-ntbiiiiiiii  hi  rlnltini;  of  I4(kmI,  411 

loiiKilmlinuU,  cnnBi'iaMiM)  tnrtti 

ripruiii  int'liHlinjt  "f  liI'miL  ■Wl 

70!i 

tl<!i*i-iilli  jivnv.  7'i4 

|i>n<  iif  tfinp  laf  filidMal  mavtn  1 

Scic^  ilif1i-n.-iit^i?  ill  mjilmtiim,  -144 

7*-, 

SllhV  jX 

n>Ilpi  artinnxif,  711 

iSiKth  orn'Pi  T-^l 

inbiUllon  i>r.  T:tl 

Sknii>l.  I'>«l 

lisir  nvpiimJ  frir,  731 

Pkin.  .Vil 

n-liUU*  tbv  ami  fonn  r/,  lUM 

sl>u>(|>iii>ii  liv,  MI 

rpik'iilNr  fnrnitiinn,  iVU 

cBl>iif<ut  rv-plraliMi,  iVK) 

liXiilllT  nf  mii-L-lo*  tlirMuA  tak 

di-rnii*  '>r  triiv,  'i'>1 

.>r  :"■;•» 

HildpniiiK  'VM 

■  1.  i[7't 

li«l»>.  -v.: 

ixiuiifoa  oC  714 

fnllii-lu'  nf.  •'liiT 

«.!   1-    '1  ,[!■                        r,-  of,  ICT 

tM'r'fiimunn,  ninoanl  uf,  M9 

rr  ■ 

.>.TT><->iiiioii  trf,  .IW 

H|ijn*1  'li-  '-■ .  'I'liiiu. .,.. .,,  ,-.itn  HI,  WH) 

r-                      Hi  of.  *"fc*S 

f.ni:.'!:  ,,   ltl.'t 

h'l  .  Dimli^  Wl 

[-.■■T.I    .     li'l 

mailvn  or,  -"■'i" 

SplcMi,  OSH                                                    ^B 

Hv«vlioa  of  ntMi,  iDi-chiiniiini  of,  S62 

l.l<Ki>lvc>i>U  o^  fiUI                        ^B 
rbcinlral  i«ii<iiinrabi  nC,  8M         ^^B 

•IRIi-liirr  nf,  ^>l 

»<>t4i-i[lnnil^  'AS 

lrni|>hBtici  •■{.  'I'A                                 1 

..f.  IWI 

^[nl|>i).'llii<n  mrpnK'Ica  of,  &PS            1 
mitri'iiiiiiil-  nf,  ■'IlKI                                 1 

1 

^^^^^^                               iifenf.  **3 

^^^^^^" 

J 

INDEX. 


1071 


Spleen  jHilp,  ~>'yl 

nHloiqHwIe^  in,  0(1 

rvliiiitiim  i>r,  ')\fl 

-iriH'liire  uf,  -WK 
ISpriiis  n  in  Hum  Her,  Pick's,  22li 
(*la|Hiiiii'  [iiii»<.le,  'J4^ 

Stearin.  IO;l!l 

Sii'llale,  iiiTve  wUn  Ili-'i 

Slt'rni>-tiia-^li>iil  in  ninn,  »ti-linn  fmoi,  !>-> 

Stiiiinli,  I'liiinivUTs  of,  li(!j 

Klimiilii'i.  luilnn-  iind  iiinile  nf  n)i]iliniliiin 

of,  IMi 
Siomai-li,  :!i;' 

iintnim  [ivlori,  .t^ll 
puniiiif  irl anils  of,  'fM 
jtnslriv  jiiiiv  in,  ;W" 
iiiDvcnitiilji  of,  ;tMO 
nervdii'*  siippiv  of.  :tH 
]>_vliirii'  Kliinilf,  ^2^ 
-tMiflurc  iif,  :il'J 

(t-mrjil  relU  in,  H^'J 
[•iirieliil  i>r  civdiiI  cvIIh  in,  lt'£\ 
Slnicinn-  nf  alvccili  uf  liinps  43(i 
of  iintries,  17>> 
of  IjInddiT,  'i4li 
I'f  Imiiii,  Tit 
of  bronchioles,  liUl 
of  {.-upilluries,  17l> 
of  eilemul  ear,  "'fl' 
of  froit's  innir,  4^1:! 
of  irrav  ninller,  (171* 
of  internal  ear,  'M\ 
of  kidnevs,  .'ill 
of  liiryiii,  SHW 
of  liver,  'ili'i 
of  niidille  ear,  'J4D 
nf  nerve,  HS 
of  newt's  hiiiK,  4ti2 
of  spinal  corn,  (iTo 
of  spli«ii,  oSS 
of  s(o»ia(4i,  ;lll' 
of  tlivnnir^  tilo 
of  inicheii,  4W 
of  ureter,  ■'>4ii 
nf  iilcriis.  Its:; 
of  veins  l"!! 
of  villi,  :!7() 

of  white  IiIoimI  t'orpn^^'li's,  <il 
of  white  iii;il[er.  ii77 
Sniininvinurv  (flund,  -!'!:< 

iHTvi'?.  of  "t:{2 
Snivn-  eiiti-rii'ii".  itW 

ii;i(nre  ;inil  aWion  of,  Ilo-I 
SiiHori^ia  rolls  ylund'^  h%V) 
Sn]ira-rrn;il  ii'Klii-^  (il  1 

i'ht-iui™l  consiiiiiuiitH  of,  '>!:! 
fiLnrtiims  of,  fii'2 
-triiitiire  of,  til  1 
Sweat -((I  a  ml  ■^.  '•■>'i 
Sylvius  aijiuiiiivt  of,  ~'.i'Z 
Svntonin,  Ulil 


rA(TII.K  ]MTiv|itions  and  judgments,  'Mi 
Taiiiljour,  Marey's,  :ilti 


I  Taste,  aw 

drcum vallate  imiiillte,  fl'i" 
tiliforiu  pnpilhi',  iliiT 
fungiform  pauitipe,  IVi" 
giulutory  biilLs,  itiiH 
Kensntions  of,  M50 
Tauriii,  10.>I 

■  Teniiieradire,  043 

eflect«  of  great  cold  on,  O.jI 

of  jireal  hem  on,  I'lM) 
influence  of  fooil  on.  IS4l) 

oil  contrnetile  tissues,  142 
of  miiscnlur  action  on,  046    . 
o(  time  of  day  on,  (j49 
of  IhhIv,  «43 
,         of  varioiis  animals,  U43 

pyrexia,  11411 
I         sensationH  of,  Hoi 
,  Tensor  tvtupnni  nmsi-le  of  ear,  947 
Tenth  ner\-e,  T-W 
,  Tertieles,  SIS4 
1  Tewta  for  bile,  :«:? 
I  Tetanic  coniraclions,  74,  tH) 
I  Tetanus,  iH) 
I         conlnu-tions  in,  liW 
I  Thalanii  oiitioi,  770 
.  Thermal  cliangeH,  111 
iThemioiiile,  111 
ThinI  nerve,  T")!* 
I  Thomeir  diu'l,  ;W7 
'  Thyniiis,  fiinclions  of,  61,1 

atriicturf  of,  til.1 
.  Thyroid  body,  (i07 

functions  of,  (fO!> 
!  slnK'lllrc  of,  (JOT 

I  Tidal  nir,  4:jH 
Tisflies,  conlnictile,  72 

■  Tongue,  9511 

Tonic  eon  tract  ion,  lo4,H17 
Trachea,  ili-'i 

stnLCture  of,  iH-'i     ■ 
I  Tracing  from  heart  of  cat,  210 
,         of  resjiiralion,  443 
'  Tmnfiidation,  phenomena  of,  414 
,  Tniniie-l  lering  variations,  HS4 
Trii-emlnid  nerve,  7"« 
'  Trochlear  nerve,  7")!' 
Tryiwin,  34li 
Try]isinOf;cn,  ^(47 
Tubules,  nriniferoiis,  oli 
Tunica  albngiuea,  1*S4 
exiiuiii,  17'.l 
intirim,   171> 
nitiiia,  17V 
iTnni.'in,  ll):ti; 
Twelfth  nerve,  74'J 
Tvrifsin,    lOO'l 


UMBII.ICAl,  vesicle,  HO:; 
I'rari,  [Kiisoning  by,  73 

riw.'  of  IjIoikI  pri-J-^uri'   in  animals 
I  un<ler,  Soli 

j  L'rca,  IW--. 

I  formation  of,  in  liver,  (HI2 

I         nitrate  of,  11J4.> 


1072 


INDEX. 


rvlsiiim*  lo  cytiniiecn  vaaD|ia«iiMU  COQ 

•ynllMTii-i  of,  Dftl 
L'rUM,  Mrm-liini  of,  -Vlli 
Vric  •I'M.  oiA,  (lO.-.,  1(H7 

■nllK  of,  1017 
rriiwv  W4 

NbuiuiQul  «inilitti(^iitn  of,  'I'JS 
iilbumiii,  hri^ 

acidity  iif.  -'iSti 
■iiiiiLial  t'i,  W£: 

I1>III|UU4ll<i|l  l>f,  .'j28 

fcnin'nlp  ill.  Ji'JT 

at-iK-i'iil  i'liiniru-r>  of,  334 

Til)'|>iiri('  mill  in,  hHi 

iii'Tinmii'  -"ll*  in,  "lii 

ii.pn-iiiiro(!i'iioiw  ii'tuiituiiiU  ftf,  8S9 

iK'Tiiinl  iTinutnii'  iiiiuiiliiirat*  t>t,  hit 

liiBi'icnK  ■•J",  Urt*! 

rciiciii^ii  of,  *>'2A 

rclnlitiim  of  HH-tvl1oa  of,  w  Ibntl  mhI 
itrink.  -VU 

•Crrvlioii  nf.  •li'!' 

xlcimFmlnr,  M8 

•jifcilii'  itmvity  al,  tt'iA 

urea  ill,  iVJ-l 

nrii;  oriil  in,  A*J-> 

uTiiniim  u(^  in,  321V 
rriiiift-ruiK  iiihiili^v  'iM 
rnibiliTi.  Il).'>'* 
^^•<'^' ill  rill,  XfXiii 
Uterus  WS3 

o*  uteri,  V82 

ftniniirr  ..f,  W2 
tllrUlM  .rf  Mir.  tfVi 

\rA(iIN,\.  mi 
Vof^up  ni-Tvi".  751) 
Vii1luiuiiin'>  hn'niiiitiviiiMiwti'r,  200 
V'illr«>  of  ht-iirl.  )»:; 
VnriotH  forniK  of  Kiimuli,  75 
VoHiJar  nminKcuii-'nl  i>f  tfai;  kiilix^,  ti'll 

IT1lvhHnT-M^    ITIt 

Vac  difi'irii",  K'l 

Vo»o-v€iU!"irioi.ii  librw,  ruorw  irf.  27:1 
arrviw,  I  111 
-«lilali>r  lilirvr^  ii'iinv  of,  £7-1 
■Rtiitxr  iiiliiiiw,  'I'Vt 

etiitti.  oT,  27 A 

VrioB,  IM 

IiIikhI  j.rtwnro  In.  IS6 
orviiUli'Mi  in.  Tn|>idily*<>f,  JOS 
miin  f>r,  I  si 
oln>ii('ii,T  of,  184 
tirurtui*  I'f.  ISl 

TRMimoliir  ncrrm  oJ,  2ft6 
wIDi  valvMcUwd,  ir'2 
opening 
Viil«ciQr  uf  blood  m  uterins  IW 
ill  (^pillarin,  SOS 
«f  ill*  jiulw  VBve,  333 
Vmoiw  {>iib^2S0 
riiMiM^  883 


Vcwnil»  f  caiinaJai,  l'S> 

Vllinlinff  liminit-furk  with  lhv|itTt>  i 

»7 
ViiTordl  hniMUftianwfer,  MM 
Villi,  chanrtot*  «f,  3l» 

rtruaiur  of,  370 
ViMiii,  908 

biniHulM-.tiSO 

rtt;>i>n  of  ili-iiiii.*i.  VM 
VwudM>l,».t7 

Initiulim,  origin  u(,  IHIU 

vt  llillMMV.  DM 

iif  •!»?.  SOS 

i.l^r-.lHlii>.90n 
(nini-iiK-iii^  •irf'tilinoiiiin  i4,  VSt 
iwiri-iiii-iii-.  '■^'' 

(imlnv.-!  'if.  tffi 
)>ar|>tc,  I'l't 
•ramliniw,  kAi.  WM 
irliili%li|:i 
v,.|t..n^,  ttl.! 
Vhplliii.  1(121 

ViinviiiH  tiwly,  fVS 
Vocal  itinli,  U7U 

lll('VI-ln<*lll>  »f.  V'S'i 
Vnlilioiiut  lniii<il->->  in  ilie  ninl,  iCS 
Voliinimry  mot' |<      '     tin.  «ii 

111  I II  ilip  lontr 

I     I      III 
Vwnilinv,  U\ 

WATEltY  vniH.r,  nlinlallun  •<  «lt 
M'nic,  i-rinlriHlion.  US 
WblK  blood-corviiH'In.  '>! 

rlM^nlcal  i-SBRiiniittH 

iiii^niiliwi  (if.  M,  '.SM 
■imaiimu  nf,  114 
niiLlri  i>f,  frl 
Diuiilrr  "f,  fit 
iriri;e>>i  "',  <)>i 
|irui»>rtu>n  of,  lo  ml, 
fi(r  of,  01 
tffiiFliirv  of,  (II 
iniiiif»niidiiiia  itttv 

«7 
Wrfk  <if,  G0 

Whitv  uiniiiT.  I£>.  lOU 
Wtlli^  i-in-Ic  of.  KM 
n'nrlc  diinv  hy  Uvn,  SSa 

XAXTIIIX.  HCO 
>kaiiilir(ii>n>icic  tM  for  iiin>uUv< 

YOrNO-llKLMHO!.T2  iheorr  oT 


ZISX,  looe  of,  hS8 
:!faia  iK-Jliiada,  WO* 
Ninn^ima.  CSi 


LEA  BROTHERS  &  CO.'S 


CLASSIFIED    CATALOGUE 

or 

J^EDicAL  ^  Surgical 

^ifblicaiions.  ^M 

TiiMUiift  1I11  »t[iiiii rilnymfwilfiiiliiilii  miiVii  iiliiiittml  In  A*  tjllowtng  pm^ 

th*  publiihus  vniild  Mat*  (hkl  BO  faiam  at*  fpRiwl  to  «mum  ■  osatiDuuiM  of  Ui*  ocnfr 
rtco(«  fKTDMl  for  Ui«  publicklioiw  or  th«  bouM  iij  \bm  caitfal  Mlcctioo  uid  aoeiintj  uid 
linuli  of  Aircution. 

Tl>«  pr(cil«>l  prlrM  aw  llinM  »l  wliicli  Ivxik*  on  ic^npnillT  li«  mippllarf  hr  Ixxiliffllpri 
tbrougliout  Ibo  Unitol  Sutn,  vbo  ran  re*ilU]>  procure  (or  lb*)!-  cuntoawn  aaj  icork*  Dot  ^ 
kept  is  stock.     Wlier*  nccne  to  Ixmkalorta  U  not  MiiTenlMit  liookB  «)U  b*  MM  bj  mall  lT^| 
th*  pnblliihcni  p(nlp».l<l  on  rMwipt  nC  !]>«  |>rinl4<l  prir*.  uid  u  th»  limit  of  m^Ublo  w«4f(l>t^ 
hubMn  ninoTwl,  DoditBctiltj  will  b«  pipcrjencn)  in  ntiuumng  ihnnagU  lb«  piBt-ofGoa 
u)7  work  In  thia  cnulogue.     No  naki,  howerer,  bk  uiurunl  either  on  tli«  Dion*;  or  , 
on  th*  bookiv  »nA  DO  publloUlon*  tint  oiir  own  «r«  «ii)i|illed,  »o  thnt  |[«ntl«m*n  wil 
nwBt  out*  Bad  it  mort  ainr«nieDt  to  deal  with  the  iwarot  booknUer. 

LEA    BROTHERS  A  CO. 
Koa.  TM  ud  T08  aureoM  Bt,  Pmupici.rmA,  8«plnnbcT,  1S91. 


Practical  Medical  Periodicals. 


THE   AMERICAN    JOURNAL    OF    THE    MEDICAL 

SCIENCES.  Monthly,  $4.00  per  annum. 

THE  MEDICAL  NEWS,  Weekly,  $4.00  per  annum. 


To  ont  aMrma, 
pott-paid, 

B7.80 

p«r  anniiiB. 


THE  MEDICAL  NEWS  VISITING  LIST  4  styles,  see  page  3  ,  $1.25. 
With  either  or  both  above  periodicals,  In  advance,  7Sc.  ^ 

THE  YEAR-BOOK  OF  TREATMENT  (see  page  17  ,  $1.50  With  either 
JOURNAL  or  NEWS,  or  both.  75c.  Or  JOURNAL,  NEWS,  VISIT- 
ING LIST  and  YEAR-BOOK,  $8.50,  In  advance.  ^ 


Subscription  Price  Reduced  to  S4.00  Per  Annum. 

THE  MEDICAL  NEWS.       * 

THAT  TUK  Nkwv  fulfill  iho  wiitl*  of  mira  in  Mlivc  pmutiiv  i>  miulc  clear  t^  Um 
MMdy  (;rijBtli  i>f  ll*  tvlocriplion  liM.    Tbia  iatium  of  raadera  bM  rcodend  powt- 
blc  ■  mluciianin  ibe  pricvof  Thk  ^Kin  bi  FofU  Dollars  per  year,  n  that  it  it  kw  , 
bj  br  iWcbtiapcM  M  wfll  u  llio  bnl  Inrfo  w*«kl7  Journal  pnUkbed  in  AmtHca, 
By  in«BiM  of  The  MzdicaI.  fi'Eird  rv«qr  |ib]raicUn  b  now  abla  al  s  nilniaititn  i 
lAliwurabisoirnrK«ipt<irtbeekrlMm  ami  mart  oatborilatlve  iafomaiion  on  all  mi 


bBA  BkoTHBM  < 


THE   MEDICAL   NEWS— Continued. 

of  ifll«r«tt  to  lli«  gnal  nmliiBl  worlil.  Tli*  (crainat  writvn,  Wadwr*  aoi  finctlL 
e(  Ibe  dajr  fiirnUh  nrigionl  utidc*,  otiniciit  l«ctiir«i  Nail  tmUst  tia  pnctlal  ail* 
tbs  UUM  mdJioita  In  liadin);  bmplinl*  art  i>tamptlj  r«]i«n«tl ;  •  onodMiMd  Mn»W74 
pngm  H  glnancd  mcli  vMk  ham  m  lox^c  eii  liaii)[*  llM,  CDn]|«iB!ng  Ibt  b« 
at  boms  luiil  nbrntil;  a  *pcdal  dcparttncnt  ii  aisigDeil  lo  ilalrai-U  rcqujrii^  Ml  tra^ 
tDUDI  for  projwr  jirMiinUtiMi ;  adllorUI  article*  an  Mnind  from  trHtan  abU  la 
iiwtnictiTel/ wiib<)ucBllo(uar  Ili«ila7;lwi>^*r«e»rvru11/  rerivwHl ;  momj  pmomllip 
•r«  t«pftMi)t«il  li^r  tli«  |>llli  >lon«;  rcfiilu  cnrrctpaodenc*  i»  fumuilwd  b;r  gsndaiim Is 
poaitiun  to  know  nil  otviirrmcea  at  itnpiittanM  la  ll>«  dlHrlrl  nirrrnitulla]!  Iinpwtul 
medical  ccalm,  nod  minor  mallere  of  tntercel  an  groupvd  lacli  week  iiDd«r  nen  IMk 
ETorrllilng  b  yrMtatod  vitli  sitcli  bn^vltj  na  » compatibU  with  clcannw,  ami  ia  lU 
mnst  aiinclit  e  BaBnrr.  In  a  word  Tub  Msucal  Sm  b  a  criip,  fnah,  wmIcI;  m«» 
pajicr  and  na  mch  Mtnpin  a  wgll-niailud  spli«««  of  tuafiilMM,  dbtiact  uul  ci]iu|>» 
uMiuirj  (o  tliQ  hImI  montlily  nwrKuiiic,  TuK  Ahxhicax  JovrhaL  or  tmx  Mkdku 
tJramci-nt. 

The  American  Joui^nal  of  tijB  Medical  ^ciencej 

Published  Monthly,  at  Four  Dollars  Per  Atmwm 

&lenuiioaila>eventrHMKocid7faT(li491)wilhaMiiraiKworincT«aatdiiMAiln«k.  Eacw^ 
■gxl  by  Uia  gpiplrtllc  tPdoneiawt  otth<  prefewlon,  m  inJicrttd  by  a  growtli  in  iUwbMrl^ 
Um  t  lot  of  fiAj  p«T  cent.  usM  iu  appeanuioa  M  •  Doonlhl  J  at  a  reduced  pricp,  UiiiM  in  diatgi 
will  tpare  no  nffi>rt  to  Riaintaia  iu  place  n*  ilia  l««dv  of  latdlcal  pwlodLcttl  UlanMK 
Bang  th*  medium  chuwu  hj  (tt«  twal  mindi  of  ll>«  proEmion  diirioK  the  pMlwtMf 
jMn  for  the  pracnlalion  o^  their  ablM  pa|icni,  Tiik  Ami3ii'<ik  Jocbxai.  baa  mII 
Mnwd  tht  inaiM  aoeotdtd  it  hj  nii  uoquoitjaaed  atitlmrii;— "  rnun  ibb  □!«  alose,  ««* 
ftU  otlior  puUimtinn* of  lh«  prcn>  for  ihelAnt  Gft^fcan  d«slniT*d,  it  wooU  bapnMbbM 
npaodDoo  Ui«  )[ri«l  maji^ilxr  n(  ihv  ml  contriliutioiu  uf  (he  world  to  medial  toMM* 
during  that  pvriod."  Original  Articlei^  Reriew*  and  Pn>grcn,  the  tbrea  nain  dcpanmnai 
ialo  which  thaconUnUorTiiK  JovnNAi.  arvdiTidod,  will  b«  fotinliopMHWMUt  Ki«*ttr 
ial«rwt  lluii  III  t)i«  ful.  Tlii>  liri^htaM  talent  on  both  lidM  of  111*  Atllatio  b  cnliilid  b 
ila  behalf  ami  luiclliiri  will  bo*pai«d  lo  moke  The  Joukxaldiocc  than  ev«r  wvcilij  d 
ba  poidiioD  a*  the  rvi-tv*vnUilva  of  tlio  bl|[liwt  fcrm  of  mmlical  ihooghi. 


i 


COMMUTATION  RATE. 

Takoi  to^nber.  Tue  Julkml  4n<l  New*  form  a  pcculiarlj  uefiil  mnUa 
■lul  affiml  UiarrcaJen  itic  nminuice  Uiat  nnitiioff  cif  ralue  In  Uvn  praffrcM  of  m 
DatierathBllfacaMMtmiioii.    To  lead  evee;  reader  10  pcoee  tbb  peraoaally  tba  ' 
muiaUoo  rale  faoi  been  placed  at  the  viceediogljr  low  flgare  of  9T,60. 


SPECIAL  OFFERS. 

The  MsniCAi.  Niw»  VouriyH  Ltn  invent  piic«,  11,30.  *e«  ooxt  r^c^}  or! 
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paf  ing  (obKriben  to  ciilivr  ur  boifa  of  lh»o  perimGoab  fur  79  ceou  apices ;  or  JoanaL 
Hn^  VUUOK  Urt  and  Ycat^  Book,  96JA. 


SabmHtrt  mm  iMaai,  tU  lAc  dip  ^  «anl  mtmM,  eM&  (unrr*  /ar  Thk  Joitwiai.  i  » 
OManHy),  andljvr  TiiK  Skit*  (eaa  cmiaBf),/rt4  Ay  noi/.  Ay  rMtJftn^  TVs  Otmit  lor  Tai 


l9*T1ie  MlHt  mode  of  readtuim  b  bj  bank  ohedt  or  poMal  maiuij  order,  dnwa  » 
tfac'jntcrofthainiilenigoed;  when  thsevamaotaooeeriUe,  ramitUDOcaror  wteeripuai 
maj-  t«Miiit  ni  ihe  riik  cif  th«  piili)UIi«>ri  \>j  f'innirding  in  rr^iMtral  \eitm.      AdJrna. 

LEA  BROTHERS  &  CO..  706  &  708  Saasom  Slnet  Philadelphia. 


THE  XSDICAL  ySWS  riftlTING  LIST  FOR  J899 

Im  ^ubli>lie<l  it)  four  nrlcn,  Wtvkly  ^liiti'd  fur  30  palicuu] ;  Miiutbly  (uwlnlcd,  for  190 
paucnu  pw  nanUi ) ;  Prr)>»l<inl  {iinUl«d,  for  30  nalimU  >MktT  per  year) ;  aiuI  Par- 
fvtiial  (uaibMd,  fur  60  tulirnt*  wmkl^  )ier  rear).    The  OC^wtient  )'cr(>r[u&l  cotuirta 

du*  uiil  17(1  pan*  of  tyMrt*!  lilankt.  Rm4i  MvU  U  id  «n*  iirali*t«hiin«(l  bock,  lexher- 
boiiDil,  wUh  puck(!(,  (WDcll,  niMivr,  eosiMr  litl>lct  ami  nlhMcf-Kale.    Price,  ckcb,  t1^. 

SPECIAL  COMBINATIOHS  WITH  VISITING  UST. 
Thk  Amkk.  Joiriiv.ti.  Iff/  niih  Vl-jtisu  Li>T(t1.2&X"'VEAH-Booic  (f l.SO),  fot  ^TS 

TlIK   MkWC*!.   NkUtOU -  .1  ..  n  ..      4^75 

The  JoiRXAL  Asi>  Nrw*  iJTSOi        "  "  "    SjSG 

The  JdiKKAL,  N»:«>.  Vi.-itjs..  Lt-t  anJ  Yluit-BiXiX  (•«  (Mpi  17),  ,         8g60 

TIili  lUi  ■•  ill  ihu  eouM  Im  iIhIiviI.  Ii  eon- 1  tM  of  dliMWH  wraond  *J|itiiLbet1i»ll7.  (Irloi 
Hints  (■•(Wnoiliil  at  uwful  InOlItnUIOD,  Mact  i  UDdsr  Mrnh  ■  lUI  ot  Ul*  pnuniaaDI  drUK*  •(•- 
ally  lar  Mn^rffvnu  and  KlvM  food  Mblacf  ■(•)••■  .  I|l<>r*'l  ta  ili*  inatmwit.  whtn  ordarad,*  ll»dr 
MM  ih*r«fi*iitl«.— OnuWiai  jV*(«Hmv.  I  i(ffrr*D<wThucnUI*ii*rlfl-if>  itfnralf*«L  Tiila 

ll  It  •  muur^lcet.    Bmae-  of  Ilia  ft«uu«a  ua  i  it  a  baWra  iiaoullu  la  Uil*  Vblltas  lJH.-^p»tm 
paolttf  M  "Ttif  Madlctl   Sntt  VtaKInK  LUI."    nan  wu  ffanon,  Daoambar. 
ooMbV  <'>■  Than[>tMil'^  Ttli1<-.  i>r<]«rad  trnm  Pr.  |      For  ooara  Amv*  and  ala^ona  II  It  not  •iirrwa 
T.  IiMidar  Kpnnlon'*  bonk,  ohlr b  poolalna  tlia    aWa— OMMMt  OawHf,  Nnvtmbtr. 


ry/ii;  itEi>icAL  utews  phyhicianh'  mixiBR. 

OODtabiiae  300  page*  of  floe  liaen  "  lei^«r  "  Mp«r,  ruled  ao  thiU  all  the  accoiinta  of  t, 
lufa  piutic*  uajr  b«  cQDV«ni*oll7  kepi  in  it,  rillirt  hf  ungtc  or  <li>4l>lc  entry,  &>r  a  long 
pfrioi  Slrmglr  bonnil  in  Icatliw,  iril)i  i-Iulh  <itlM,  iimI  villi  «  |uil«iil  lleiil'U  liaefc, 
wliick  p«nniU  it  to  lie  perfectly  IIbI  wheu  upciiol  ai  any  i>U(«.     Price,  f4jXi. 


BASTSHOBJfE,  UENRT,  A.  M.,  M.  D.,  LL.  D^ 

tMt^  PnftttBr  of  ayfimt  tn  iw  IMnrtUf  of  i^uu^mnt^ 

A  Conspeotua  of  the  UedJoal  Soienoes :  Cnntaialmt  Haodboeltaod  A: 
PhjtMnfr,  (  bc<iiiiiiry,  Miilvria    Minlita.    I'rM^icr  'if  Mnlicine,  Hur^et?  ud  0)»t«lri». 
BmdihI  editioo.  llioriniulily  rcTJatU   and   Kidly  imurotod.     Id  oao  lai|a  mjti   l^o. 
nluadof  lli2»  pa)t«,wiili  477  illuMiBiioiu.    Ctotli,  HS&;  laatbar,  fthOO. 


l^a  ol^aet  ci  l^lt  i^uiutJ  It  1^  arTorJ  a  coj>iva- 
taa<  varlt  ot  nftraDoa  tu  itudanu  auri^K  >>'•>  >"t'f 
momaaiaal  iliair  commaod  «hk|p  ib  tlcvmitno* 
open  Badlaal  lannraa.  1(  it  ■  faioratila  ilea  lliit 
tt  >M  %■«•  (MOil  nanaMtrr.  lo  •  thort  apaoa  <4 


IndatUT  aad  aaticr  at  lit  able  adllor.— AMloa 
Jtahfol  and  anuafVinn<  SanL  1,  IK«. 
W«  tan  mj  with  Iha  Mrt(Ui><  irtidi  IbaJ  II  It  Iha 


Dati  wetk  at  Uia  klB4  oMIi  *tHA  «•  ar*  as- 

. . --...--    -        -    --    qualntad.    tl  ambudlM  la  a  eoodantad  torn  all 

UMa,  lo  Itma  a  naw  aad  carallilly  r«ibad  vdiUoD.  racant  eoatrlbuUont  la  anttlctJ  fnnlloiat.  and  I* 
Tka  illnaUBltoDt  an  nryDUmtmit  aad  saUM-l  lh*r*A>T«aiafUtlDa»t7liiin|inwminnarllirouCli- 
■lijr  oImc,  aad  tach  pan  taamt  to  bar*  raaal*«4 ',  oat  our  oanony.  baddat  twlnjt  a4inua)4)'  ailtfTai 
HadaaabMaot  aiMDiloa.  Wa  oao  eoaotlt*  taatt  ■  to  tha  oaa  of  atuiltnu  at  ne-Dela*.  TiM  bOc<  la 
a  *of%  (a  ka  utatal,  doi  anly  lo  ttodanM,  bnl  U  ■  UUitullr  aad  ablr  aiooiUad^-CtarlMiM  ITidiatf 
pfw uuoaan  aa  voir.  It  raRtot*  oradll  oibd  Iha  I  JWiiol,  April.  IM, 

ITEILL,  JOHN,  .V.  D.,   atul  8XITH,  F.  O.,  M.  I>., 

Uitt  Sr^tm  la  l*t  frttui.  HitrptlnL  Prof,  i^  lAi  t-<ttil%lM  tf  JfsL  Ih  Ud  Vmw.  af  nnaa. 

Ad  An&ljrtioftl  Conit)eocbam  of  the  Various  Bronohea  of  Uedlo*! 
BolOnce,  fiw  lh«  useandeiamiimtiunaf  SlodMU.  A  new  tdiliua,  reriaed  aod  iinpri>Tal, 
InoMlargeniyiJianiaToltiBiaof  g74pf  B^»iUia74  wnodooti.   Clr4li,  $4;  Itathar,  H-^S. 


I 
I 


LUDLOW,  J,  L.,  M.  D., 

OtjulUtij  r^u>u»r>  It,  U(  P*iftidtipMa  B>tp>Ui,  dc. 

A  Manual  of  Bxamiiiatioos  opoa  KvMimaj,  Plijikilciar,  t$arfl«ry,  Pnctkw  et 
Hcdldnc,  Obn«iri<i^  Materia  Mtdlr*.  Cb«a[ilMi7,PliunM(7Uid'ni»n|i«ull(a.  To  wliicb 
ii  added  a  Medli»J  Formulary.  Tlli^lellilioD,tllonwfhlJnTiaa(LBn■)K^eallTeaUr)(cd.  In 
OHO  ISmo.  vnlutneof  SIS  pago,  with  S70  illuMMttaUL    Ckdli, |3l2A ;  lentlicr,  f3.T6. 

T)i«  arranecincnt  of  thit  Toluue  IB  Ui«  form  nt  quouunt  aad  umier  render*  il  <wp»- 
dally  tiiltatila  fcir  llie  nSt<e«xaailaatio<iofHud«fila,aBillurtliawpr*iiarlivfnricnidiiallaci. 

SOBLYy,  RICHARD  »..  M.  V. 

A  DioiiODarj-  of  the  Terms  Used  in  Hedtome  and  the  Collateral 
ftclBQCes.  K-^vi-i-il.  with  ii'imcnxM  *•!>.( jti<.>Il^  t<y  Ihaac  Uavts  M-  l>.,  Intc  «litor  at 
The  Aaieriuii  Juuraiil  uf  ibc  Matkn]  Scicoce*.  ta  one  Urga  royal  IZumx  Tobiaia  of  SSO 
doul4a-«oliiiuiiod  paitca.    CIollk,tl^;  leaili«r,  (2.00. 

tl  l>  vb*  kMt  took  at  daSalUra*  <ra  bate,  aaa  e««ht  alnn  *•  k*  aaoo  On  WtfTt  V^.-aamUm 
Iftifcxu  g-d  Ja'iwal  Jttrwal. 


Bbotsxu  k  Oo.'a  Pdb: 


THE    STANDARD. 


THK 


DaiionAL  UleDidRi  dmionmY 


INCtUPINO 


£i^Ssli,  French,  Qernau.  ftaSan  and  Latin  Teckmcal  Terms  used  in  Mg 
the  Ccdataral  Sciences,  and  a  Series  of  Tables  of  Useful  Data. 


BY 


Jaho  %  Billing?,  I^.D.,  LLD.,  Ediq.  Bud  HQfV^  D.C.U  ^^ 

iltmitr  ef  IJu  .fjtiinwt  Ae»t¥'X  o/Siifua,  &irfm  D.S:.A^IU. 
WITH  TUB  COLbABOKATION  OF 


Pmu.  TT.  o.  AlWATKK. 

a.  M.  ttrKXElT,  M,I>.. 
W.T.COi;.tCiI.MAN.M.Di, 


JAMRA  JJ-  FLINT,  ».  D- 
J.  II.  KII>I>KK.  M.  K 
WILLUM  LKE,  M.U. 
R.  LOHIM,  }I.Li, 


WA)«niv<;roN  >iikTTUtir&ttB. 

C-S  XI^'T,  M.ll, 
H.  C.TAUItUW.M.Ii^ 


Id  two  very  hundaomo  royal  octavo  volumea  oonuiaiag  1874  pacM, 
with  two  colorod  plates. 

ttr  rotunr-CVDM,  $«!    lA-alA-r,  ST  1    Naif  M-^tfm,  Ar»rM«l  IW««,  O.AO.    ArM* 
bjf  8u6*cp4j*tUrH  only*    ffjiroltfiriijfrtjf^irit  uji^f(n1ff*fia    ^44^f««CA«  ^aMIjJfc— , 


Th»  MiUbh«im  han  gml  pI«Miii«  in  pnamting  to  tb<  ptoftMloo  a  n««  ptMlmt  1 
'linildiii  olctlonuj  •mbrsciiiK  Id  oa»  alphabtt  ftU  cumni  urmt  nacd  in  emy  dcfan*  I 
nicnt  «f  medicine  in  the  li>e  irrMt  lingukgn  wiulilultng  modern  medioj  lilenUon.        ' 

For  ihp  TMt  nnil  mnipWx  Inbor  inTnlTcd  in  surli  on  iinilcrtakinK  DO  one  tifitcr  (|ial^ 
fled  lluin  Dr.  Itillinjjpi  I'jiiUI  hair  brrn  evlvelwl.      Ilu  liaa  jilannxl  th«  wtirfc,  cfaoco  tb 
inoal  nccontplulied  men  to  imist  liim  in  «|i«rinl  dcpartnicat*,  and  pctsanalljr  miptt^mA  I 
and  ouuibiiiml  ilieir  wurk  into  a  conajslirnt  luiil  luiiforin  wlioto. 

6p«ciii1  rare  hii  l>Mn  tukni  M  rviiilfr  tli#  ilcGnlllnoa  clear,  sharp  nnil  um 
TI1C7  ore  gireti  in  English,  nith  ijaoii^uin  in  French,  Uetnian  aad  IIbIuid  of  lit*  1 
iupottanl  Ronla  In  Englinh  nn>1  I^ulln. 

Bepnleil  HH  >  dii'tionury,  ihercforv,  t1ii»  lUmlnnl  wndc  «i]>fili«B  the  ph;— 
■urgeoo  uiil  tiiecinlUi  with  all  iafuriiiation  ouncvming  mnlitiil  wnnli,  Hmple  a/iil 
pound,  found  in  KnttHiili,  Ki'inji  rairccl  k]>cIHnE,  rimr,  iharji  ilcfinilloiis  and  actirr 
Don,  niul  furtliennure  it  tniiblw  hint  to  n>iiHiili  forvii:"  ""rk*  and  to  Utnlentawl  ibe  bm* 
and  inccnuing  number  of  furrign  Konla  iik>1  in  nmliiral  Engtiili.  It  m  eapr^allrfan 
in  (iliiiius  ooRiptbiiTiK  two,  llinio  or  more  nurvls  uxd  in  qicciil  wnaw  in  tha  tatiaa 
(l«i>iuiiijriiu  uf  iii«ilicine. 

Tliu  Hork  in,  huwoTvr,  br  more  than  a  ditiieiuiT,  and  poiukr^  <•'  '•—  ■■-mrvc/i 
mcvcloiHnliii,  lui  it  kitc*  in  lis  body  a  larss  amoiint  01  raluaUo  iIhti-  .i..|  cfafBi-j 

oil  informntion,  mid  Kf^tipa  In  It*  tablnt.  in  a  tomlen8><l  and  omt' riu,  k  la 

anuMal  of  impurlant  iliita  wliicb  will  be  connitlinl  ilall^  t^  all  In  avtitc  juratiic^ 

The  auniilctcncB  of  (he  work  ii  luuilu  eridenl  £7  ill*  (act  that  it  drflnc*  M>Hj 
wjmnte  woiui  and  ]ihnu4i>. 

The  type  ha*  been  nia«t  cnrefully  Miected  for  Inhlnen  dikI  doaraen,  auil  avefTtluiy  j 

beco  cfooe  to  ncure  ewe,  rapidiiy  and  dnrabUitjr  in  i»a. 

thr**  tnr»l«ts  taBllDen'a)  Iubdhcm  ahltn  M* 
rlchaii  In  mtdlnl  huniikn.  To  iwl.l  u  »•  hb- 
fulnrt*  n±  «  truta  of  rrC*r*iiOf  .<im*  Tt<aiT- 
ublva  u*  BliOD.  AnoUiK  (vaiurv  <rf  ili>W",a  m 
ilm  Mciicai'y  ol  It*  drAnltInn*.  an  nt  whMb  twi* 
bna  eliackc-t  by  caDiparUon  allli  luwv  •<>■ 
*Uu4uil  votlu  Is  Ida  cR*cTt9l  lincuiiaa>  II  * 
with,    A|«rlfnni}  lAf  i '  ■i-'r<aoMn*"r 

llfin  whlDli  may  b*  K  "  xudretaa 

dleUOD*ty.unBli>»nbi  .  - .  n  k  un>Mr  kwv 

lorswllnwllljpnnjr  no;  ivrlio^fal  inailMlai 
«f  in<F  laur^tHef  ninlarn  Tinfiai  1 1     Tlm< 
aoi  bn  two  auiuldna  aa  U>  Hia  araiM  lala*  ■ 
(UUwMc4ilil>ill(«lnn*ryM«l<a4iof| 
•ooaRvall  t«t*  aad  cM>dl(lanaor«a 
BoJWr  at  m*  haTebcaaaUatotaat^  n*| 


liaabeco 

tu  aoora  M  eoa  wblob  wtll  al  nnfr  ■4llt(y  lliv 
■tii'lvnl  BDil  ntMlalliliamiiilivnHnlaoniiainfJ' 
leai  i-iwidilaaar.     ciMrand  eenivmMa>lTe  ilHI 
Din>iiii*4r  ir«nl«  *hoii)d  fbm  the  prim*  IWalur*  ol 
any  dJrilanary.  an-l  In  iMi  on*  ihf  talpl  aim 
a*>cn*bib*i"cli*  ibrriai-l  ■■■BHIoallon  ai)>l<h« 
dUIWrvut  niHDiBic*  or  l*rn>  la  lua  ia  nicilltlaa 
aod  laa  ooiraiaral  *r]tfn4<p»  lu  laoguaga  a*  Ian*  ai 
■■MBpMIUaatih  InrldttT'    Tn*  almoal  br*il(* 
aaderadbancM  ha<*  l*»akF|ii  IdtIr*.  Tbenotfe 
laniaarkatil*,  uw.  lor  lU  IUIowk.    The  aaumara- 
(WnaaBil  ■DMirltHini  uadar  aash  <rent  haadlDs 
are  airthtnslx  oomplaia,  a*  recuiUMIkt  Ui»  Kor 
llMIMngu*  anil  LM  luisuic*  cMeBy  aniiiloTail 
br  Bnl>>fal  sad  madarn  apleacK     li  l>  ImiiuiBfMa 
(a  do  }a>tloa  l«  Uia  dlBlUrtiarf  VL**>y  iwual  IIIu* 
iraHan.     tl    fraMctt  tn  th*  InstViVi  naAM 
Ikoreuahlr  wl*niinc  cnoda  ot  *«iaM\u< 
•ocabularir  andvAaii  an  aeeatM>a^tM  _ 
•f  refrrmca  la  coanitUtii  «<»\u  in  %b.i 


Vi  iwAm  iiVVMnMauud.aBdlnrMpMloCcQRiidaiaaSBM 
(mAt  «M«na\YAifAM>KwV— Thi  Lv^tw.  \nMA,v««i.VWa 


OBAT,  UEKRY,  F.  Jt,  S., 

LKlurrr  (n  A*nl<ii:iij  nl  SI.  Ott-t*'i  BnpiHII,  tri^lwi, 

Aaitomy,  Deacriptive  and  Surgicsl.  Edlud  by  T.  PtcKBnnio  PtcE, 
P.  R.  C.  8.J  Siirfctiit  til  ■ml  L«ctur«t  on  Aiutumij  M  81.  Ocorga's  HoapiUl,  Lomlon, 
Eiamiuvr  in  Annii'iiiT,  Kojnt  Cullcm  ol  SurKcoim  vl  Eoslanil.  A  now  Ameriou  from 
tb«  clcvsnlli  cii)ar]gRl  anil  iiopmioa  IjondoD  etiiiinn,  ihoroaglilj  rvvitoil  Bnil  ra^lMd 
hr  WiuUAM  W.  Kexx,  M.  D.,  frofcMiir o(  ^iir^ir?  In  lli«  JctTtinwD  Medknl  ColUge  «f 
Philulelpbik.  Tu  wliicli  la  adilcJ  (he  •cmml  ADivrican  frotu  the  Intat  Koeliah  dlllion  «f 
Lanpmahiw,  1Iu>iual  axdSi-iuiicauI'T  Lrrimt  1Ioli>k!i(,  F.B.C.S.  In  ona lunfrU 
OttnTti  viiliiin*  of  lOOSnM^  witb  iis.'>  \aifca  mnd  tUU>rmt«  «n|inTin)pi  on  mod.  PlrlM  of 
•ditKin  in  U*di!  CloUi,|$;  leather, (7;  half  RuMis,  (7.60.  I'riceof  edition  id  colon 
(wcbtlow):  Cloth, 97.2S;  lauher,9S.2.S;  iialf  Kuw«,$&7S. 

Tliitiiaiilt  ooTvnsBionaxlMuIed  ranfcwvif  nibj«ct*lhui  la  ciutomnrr  in  the  onllnu^ 
text-boolu,  gifioK  nut  unly  lilt!  delaiU  Dewnarjr  fur  ll>«  «tu<l«at,  but  >l»  t'hc  apiilicatiaD  of 
tlicav  ilelAiU  to  Ilia  iinurlicc  of  medicine  nnJ  luner;.  It  thiw  firm*  both  a  fiiiile  for  th« 
Ifanier  nnil  an  iulminlil«  wotk  ot  ntmnacm  for  ibt  ticllee  pr*(t!tl(in«r.  The  eagTavinM 
foriD  •  ifirciul  Tenture  or  tli«  work^  many  oT  them  heln^  the  siw  ot  nature,  iwarly  ul 
orig>iu].and  baTins  the  nunia  of  Ihe  vaiioiu  parti  pnntnl  on  the  bodyof  thecut,  in 
0tie*orflKureinrr*reri>iici>  wilh  itMorlntlona  at  th*  foot.  In  iKi*  clilkin  a  amr  ilcpanur* 
naa  hem  tsben  hj  the  Imio  uf  the  work  wllh  the  nrlerioi,  Tcins  ami  nerrea  diitinKuiahed 
bv  tllt&n'iit  oolorn.     The  cnpn(ingi  thiis  form  •  conipUtc  aiv)  iiploiiUiil  arrini,  «hl^  will 

Sc*iIt  kwul  theilnilenc  in  forming  ■<^tnl^  iilraof  AiuUm;,  naa  will  alfiiwrre  to  r«0«tib 
•  iiiein->ry  nf  llit«e  wlm  uinr  linil  in  tht  exiiceni'ita  uf  pnMicv  the  neccHitj  of  recatl* 
iDg  ihe  ilctniU  of  the  JiBeciiog-ruum.      Conihining,  aa  it  d(«a,  a  tmnnlele   Alloa  of 
Analuniy  willi   a   tlioroiigli   ircuuao  on  ayvleinalic,  doiripliir*    nn<l  aj'pile-l    AiiKtotuT,      J 
the  work  will  lie  foiind  of  gttM  Mrrire  Ui  all  phnicians  whu  r«*tTe  ttiideula  in  Ihelr     I 
ofiic«t,  rcliering  ^Mh  preoeptor  and  pupil  of  inuca  labor  in  laying  the  grouwlwurk  of  ■      * 
thorodgh  medical  education. 

Fnrtheconvtnleneeof  tiMae  who  pioffr  rmt  la  pay  the  alishl  inirmM  in  cml  neT«al- 
toteil  by  the  uae  <it  <xAe>n,  the  rolume  la  published  alio  in  bloidk  alone,  end  maintained 
is  ihia  uyle  at  iho  price  of  former  odilion*.  DoiHriihitandinK  ita  lancolr  inrwaaad  hm. 

Liinilnuirti,  Wtrluai anil Su'^ttal.hj  ih«iliitliitciiihlie<l  An:l^|lIlipl.  Mr.  Liilher  Iloldea, 
ha*  been  np|i«iiil<d  la  Ihe  pm«iil  eilitiuu  oa  ii  wia  to  the  prerioiis  one.  Thu  work  giree 
Id  a  clear,  conderued  and  (ynteraniic  way  all  the  information  by  which  the  pncUtioncr  can 
determlDe  from  llie  exirrnnl  mirfnre  of  Ihv  lx'\y  ihe  poeition  of  Internal  (dft*.  TTiue 
aonplete^  Ibe  work  will  furnUb  all  [he  OBiitonoe  that  can  be  rcoderei]  by  typo  and 
DhMfatiofi  in  ■nntmntcal  itndy. 


^iamf*lpaputflJ«(>rkonanat4mretv<iTTH(40, 
It  n  •ufllElvnt  10  ujr  t>r  tl  lliai  ililx  tJIiIod.  itiaak* 
•o  let  AmFflmn  adltnf,  riirpu-*B  all  ultiar  *4t- 

Uam—Jo^.-fi'uA"*^.  ii'i.  Ah'i,  |)«o  ni.ian, 

A  wwfi  whIaTi  for  morfr  than  twnly  feanha* 
kad  Uia  lMai>r  alluhrr  ttii-lioaliiioD  anaconiy 
thronallinui  tba  dvlUBatl  laortil  ^omrs  10  haoil  la 
•aell  MBUIJP  ol  •laoutlnn  und  vfaney  of  l>il 
and  llliuMUon  a*  morn  ihan  'o  mall*  eoul  ih* 
lut*  prMnlia  of  Tha  pru>|wi?iui.  It  woala  <ia  in- 
itoA  dlfflKiili  (■>  noma  ■  fiviun  itliania  Iha  pr»- 
•at  kta9t\f*ti  #H]iik>r]  "I  *ir%y  E^'iiitil  Im  mandod 
or  Miimd.  aD'l  11  ornl-  n«  rmpti*!  lo  t*r  Itiat 
Iha  roraJ  work  liddvdDcdrormaDyyvar*  tneixna 
M  hofd  tha  Irtt  plaM  amoDK  aixuoinleal  leit- 


bonkiL  Tlin  wcrrk  It  tiuMlihad  atlh  tiark  aad 
eoloKii  jilLEf-f.  It  Iva  marrel  of  t»Tk'mak[nc,— 
A^tfiffi  ['t-t^litui'iit  u'ul  ytiifi^  Jbi-  Jl,  lua. 

Oraj'n  A-iAl^irny  L«  (bo  Rinti  m ui^ ' l^fan I  work 
iipoo  aaaieniy  whlah  tiM  attr  hr*D  iioMiinvd  M 
ih«  Snallah  ft  any  oUtar  laacuaaa.— OiwMaa^l 

AaUWb«oknawD«tDlhapuiolia»r  h*  U  r«- 
ealTlas  Dia  baatworkes  aaatom*  thai  s  rulillahad 
InanyraaRiiacai.— IVgiaujr*l.JVv</tfy.liw.  IMT. 

Oray'i  •ian>l*rJ  jtmtotvv  ban  IXBU  Ba4  kUI  ba 


for  yttrt  thi  iriMaiN  for  ■iiidaate.    Ths  book 

ntMBonEy  1 

■■'m-JMMI  /VfH  1/   ITaWm  Bmt  TmK  J»e. 


on'/ 10  l>*  viamlnad^ls  a*  peclaiUy  uadar< 
WM." 


t  Auo  nm  iialx  xxrAUAT^— 

BOLDEy^  LUTUSBf  F.  Jt,  C.  A, 

awywn  lo  51.  BarlManu^i  enf  lit  AaHlVUf  gwplali.  laweaa. 

Landmarka,  Kvdical  aad  SurKJCSl.  Kemnd  American  &oa  tbe iMeat  twriwit 
Engliih  olili-'n.  with  aihlill»n«  by  \V.  \\ .  Kkkn,  M.  D,.  Pr(if«««a<r  uf  ArtiMlc  Aaalomr  lit 
Iha  I'entu.  Aowleiay  of  Fine  Art*.    la  on«  liimu.  votiiSM  uf  143  |<eeea.    Cloth,  |l.oO. 


DVNOLISOy,  ROBLEW  M,D,, 

Ltit  PrMtttjr  ^f  u,u'^r,n,f  Mi.ltti'u  in  tin  Jtfttmtt  Utdit^  QiUiff  nil^OflM, 

UEDICAL  LBXtCON:  A  Diotlooarr  of  Hedloal  Soleiio6 :  CvotAiniDc 
■  cnnnip  riplnnulionof  the  tarioiu liubjocto  aoJ  Tifruuuf  Analoniy,  I'bytiolonr,  {"aUiiM- 
ncy.  Hyf;^iFi»',  Tlicraiwiitiai,  Pliamiuolagf,  PharmairT.  Suri;ery,  OlBtetrka,  Medloal  Jori^ 


pr'^ulen'ce  an.1  DealiMry,  Nottoee  ofCllmaie  and  of  Miuenl  Walent,  Furmilv  hr  Ofldaai, 
Einpiriinlaiul  Keleiic  I*repanllcaii.  wllJitlie  AceanluailM  and  £lyinol(«T  of  ttie  TWnM, 
aiul  the  Krrodi  iiul  other  ^Twoyne*,  eo  aa  (oooiutituUa  French  lawellaaBii  Ki^bb 


Uedivl  Leiicon.  Edited  by  RictiAKti  J.  DvxaLnox,  Si.  D.  In  one  vety  larnand 
lMiAa«e  royal  octavo  Tolume  uf  1 139  lavM.  Cloth.  tUO;  leather,  nieed  baadi^  f^M; 
wtrj  liawleoaM  Lalf  Riurie,  nuaed  banda,  18.00. 

It  to*  t>ie  ran  marli  llial  M  MtWelr  ha*  no  rl*et  la  Ike  EacOak  laacwHi*  *t  aauwawt 
b4  exaal  «f  re*f«MK— XMrfM  JfaaMal  OaMla. 


I 


ALLSNf  UAMRISOy,  M.  D., 

A  System  of  Human  Anstomy,  InoIudiiiR  lu  Hediokl  and  Sorgioal 

SelAtiOnS.  t'ut  tlw  ii«e  ul  1*1*1-111  i<>mn  Rnd  SliiilniU  of  Ik(«<llctiip.  WlUi  U>  UArk 
dactiw;  fiifctkni  on  i\iAo\«gj.  B.t  E.  U.  Suaxbfkak^  U.  D.,  U|ihlWiiKiha(  U 
iJm  PkUaildphU  HmpIuiI.  C«iii[irnin{f  813  doabb-colimitiiid  iiunno  |>4«*.  wiui  M 
iitii><nitiaM  on  109  full  page  Iitli(^n|<liic  plutM,  niiua;  of  vliidi  mr*  la  ouon  *ad  MI 
•tignviM*  In  Ik*  icic  In  *ii  Scciioiw,  cuh  in  n  (xxifolkii.  SnUoo  I.  Hamunn. 
tjcdien  u.  Bones  una  foitrm.  8<vttnn  III.  Mr-tci.ra  aud  Pahis.  tUMUon  IT. 
AxTSun,  Vn.sa  ahu  LrwrHATiL-H.  t<«ciion  V.  Ninron  BrmH.  8«cUoa  VL 
OiKikm   or  Sknm,  or   Diuncrimc    axd   GtwiTo-UttiSAiiy   Oroak*,   EwoiTOUwr, 

Dm-ELOI-MIVT,  TSKATOI«OT,   StTERriCUL  ANATOKT.  PoCT-MoaTnl    BZAMUIATMIB^ 

AMi>  Ge»KKAu  AKu  CuMK-Ai.  Ivi-KXEi^  I*n(*  {icf  Section,  I3.S0;  Kteo  Iouk)  iatv* 
Tnluiii«,  clolli.  $23.00;  very  handianie  half  Rluvdn,  micctl  band*  Ubd  gfxn  Imck.  K&A 
FVr  tait  bf  nJurriptiim  only.     Ap/iiy  hi  At  PuliluluTt. 

Tliar*  U  w  hm* 


l(Ulab«  con*]  -fliTAd  Bsladyuf  ftfifiUfil  4nMoiny 
la  Ha  wIHmi  >mi>w — •  uiiiiannitii:  vi^—niniloii  o( 
mcb  «0Mi>inkBl  fipu  u  tao  >.<  t|<|ri]til  to  tlir 
Pfattloa  c4  ntillolav  a«  ««1J  aj  of  *iir|:4ty.  Qui 
Mibor  !■  MDDito,  acoiinac  aud  |jr«^ll(^  In  li> 
Malanaiita,  and  imctvad^  adi»ir&hly  la  Intuilng 
•■  iDOnM  IMO  lk*MuilT»riihat  1iK*nara]|y  cdo- 
aldara4  •  4n  tuhft*.  Tlia  ilniianniaDi  •#  Blitol- 
■■■J  la  traatod  ta>  a  DUatcrJj  niauuaf.  and  Ui* 
fmiai  b  UaraUad  mar  byaoa  IhuiHiKhly  Ikioll- 
Itddih  tL    ThalltaalnUooaaramwlainiri  (imi 


<ar^  and  ar*  atmt^y  upark. 
'  pracucal  a)4<llvMloa  or  aBMnmlnJ  pBUM 


t4 


ihr't'dirT-dB]' waoM  nf  Uia  n>«4>ra(  ftlelcNa, 
tCoUKht  kaftin  an  ao  aall  |«aa«Mad  tor 


afanllnit  nncaHi.     la  IHI   li« 

oaanvilliaMlUiannliaMoata 

•riwd  antlVaUM  Uia>  ta  man 

*oo<*rDtii(  aliich  Uiay  tnaf  na>«r  ta^ 


Ku>rat  praeUUMian 
AiiDg  o{  Hr|>riwd  intlVaUc* 

pCiDI 


•Idaratlan.    II  I*  a  *urk  vkleh  la  4aaia*4  M  la 
Uia  b«l  of  lu  kUd  l>  aay  iMUMga^-JMMK  j 


CLAnKB,W.  B.fF,R,C.8.  Jt  LOCKWOOD,C.  B.,  y,B,C.S. 

The  DlBseoUx-'i  Manual.    Inoocnoekel-aiM  12an.ToUuD0<if  8M  pa^o^wUi 
49  iUtMnUionai.     Limp  ciMli,  red  •dpai,  $)jA    H^Shii^aU  Sm»vf  llmiaU,fmftil. 
l*aaar«Clarlc*aadLMkwondbata«TMMaalaak    IntlmaU  aiMMtUlos  «Mi   iMiaata  aoaU  kva  I 

■■MM  ' 


thtl  «ui  hardly  lierlnllnlaaaHBCllutald  loika 
dliaaMar.    Ttiair  purvoaa, which  to  ' 
arrlba  tlia  tail  way  Is  dl^ay  iha 


bow  10  da- 
analomtfl 


Taa'abfurf 


atrUDiBra^"  li»b**nnillyaualnad.  Thayaualto 
a  lu«ldl<y  ol  dcmnDnlialloD  aad  tiaprilc  laraaaoia 
at  aii'itaaliiD.  whlc)r  only  a  loug  imlntog  lad 


Etna.  With  aKft  a  itaMe  a*  tbl^  a 
Ij  aa  otuaellra  a  naamaeiary  ar  1V* 
AndM  <laaliH>v<>aina  aarlail.  an  Madaai  .  __ 
iMIUMdaMlyandalMnrblacly  lotaaaMad  la IM 
■Mdy«(  laatomy^Aw  Orfaaaa  JftMaaf  aadA^ 
fItiljKtnM,  Affll,  UM. 


HIJiST,  BASTONC,  M.D.,  A  PIEBSOL,  GEO.  A.,  Jf.Xfc 

Pn-funr  tf  4biUln»H  On  Puiiril^  /HfaiMr  ../  A  •■alt'v  m-J  ft»t»iwfcm  ai 

4r  fgnHj<fi<a.  '  ■*■  (,'—nfiii>  ■■/•  fma^liiiit^ 

Homsn  ICoiUtrOBtttoB.    Hagnitiofnt  fcUo,  mnuiuing  ahnit  ISO  MgMof  HB^j 

lUuMfflUd  with  ra^vinfiL  and  nanjr  plialcignpluc  pbtc*  froaii  nature.    In  fMir  pan^  ] 

pric«,  «acb,  fS.    LimitGil  cdllioa,  for  m»  ty  aDbKriiiuan  only.    AddrwM  tii«  pHbUthmJ 

TREVM8,  FBEHEBICK,  E.  B.  C.  8., 

fif^v*-  l**mimtlT«i^  Off  AtHttty'ii,  at^  A  *mJ«<  ^'faF jw  at  lAa  £ctadm  tfa^yalaL 

Surgical  Appliod  Anatooiy.    In  «■•  podtM-aiw  ISmo.  votiuue  of  640 
Witb  ai    (llnurUioB.   Litnj)  dolh,  ni\  «(|||W,  ti.W.    8<«  SCwfniH'  5cr><a  qT  JW«wiij 
P"Be  3L  ^^ 

BELLAMY,  Bl>WARt>,  F.  B.  C.  8., 

Tho  StudoDt's  Guide  to  SnrcioBl  Anatomy:  Being  a  DoKripUoa  of  Vbi  I 
BOH  ImpenaM  Kiinioal  Kwlawof  tlwHumaa  Body,  ukI  JnltwUd  aa  an  lolradtietba  M  j 
opentirefiurgcfy.  lDo«ielXni<xTCfaiBHofSOOp<ig«s^viili  MilkutnUeoa.   CiMk.C'" 

WJLSOy,  EBAS.VUS.  /'.  R.  8. 

A  System  of  Humim  Anatomy,  Gsnonl  and  Spcckl.     EdiiBl 
QoBBScMT,  M.  D.,  Pratascn-  of  GnunI  aixT  aurglMl  Anatooiy  In  tli«  HkUoI 
Okio,    In  ooe  large  and  hmdionie  oclaTo  Tolum*  of  flltt  pogei,  wUb  SS7  lUu 
Cloth,  KOO;  l«.tbpt,  »S.OO.    

CLELANV,  JOMN,  X,  D.,  JT.  «.  8., 

JVtfwairnf  .lMi>«a^aa<rt»Mife(iyi«  Quin*!  tWfa^  Oa>i>«. 

A  Dirootory  ftor  the  Dineotion  of  tha  Hamaa  Body.     Ii 
Tolnma  of  1*8  |iacta.    (loth,  11.29. 


HARTSaoityra  bakdboor  op  axatout  i 

AVP  PHY810LOG1.  SaMod  adHlM,  nalawL 
la  «■•  m al  Umo.  ttitnua  «f  «U)  ta«ia.  <aVk  n> 
WOMMIM.    Cl«lh,tl.». 


nORtrBlfftBPECiAI.AKATOlIT  AKD   

our,  _  nckUi  adlUi^  aXMiMHly  rwrkMd 


mfTMrl 


ibMMlal.    [DM«oo(arontnMaaa(  MiTne^ 


wWlil 


I 


fMBt  JOJSWUr,  M.  />.,  LL.  D., 

Hedloal  Phjraltn.  A  Texi-book  far  !5liiilei>C>i  and  PncthiiMer*  oT  MmUcEm.  Is 
MWi>ci>iu  TL-liinii-of  734  |»);n,  villi 376  voadcuu,mnaU_*ori|[iaal.  CloUhMi 

PROM  THE  PRBPACB. 
TTi*  hct  thkl  B  Knowlwlo*  of  PliyiiiH  is  iiiiliaiiwiiable  U  %  ihocoogh  oadonUnilliiK  ti 
Medicine  lias  nut  Ivtrii  m.  fully  n-nliu.il  in  th U  oouciI(;)t  •«  in  Eiin>fi«,wMr*lli**iIiiilrahlft 
woriu  d  Dtsplai*  snd  (inijcl,  of  IbibcrtM-m  mnd  of  ounwoui  G«tiaaa  writm  OMkitilute  a 
Icwwb  ti  •ilucniioiwl  IJMnttiira  Ui  wlilch  w«  on  Atm  no  nKnUlel.  A  full  B]i|>r«cimlloa 
of  ll)l>  lh«  author  tniK*  will  be  cuffiviMit  jiinillalmi  lor  plidjis  in  bixik  IWm  th*  nb- 
Maiuia  of  fab  ledum  on  Ihii  deparuiiont  of  •nonce,  deltTcrwl  diiriiur  maa*  vmuv  >l  tbe 
DBivMaiU  of  il>«  City  of  Ke«  York. 

Braadly  siieKktiic,  lliia  wark  ainu  to  iinpan  h  knowlcdg*  of  the  raUll««w  ciiilLiif 
bMveeo  Plinis  uiil  MciIiciDe  in  their  UMI  lUtc  »f  d#r«loi>uivnI,  and  lu  l-idIhhI.t  in  lli« 
piinnit  of  lab  object  «bNt«v«r  eniwrienm  llie  aiilhor  lioa  gainnl  during  a  l<.<n|t  livrind  trf 
mcbiog  (lib  fjwclal  bnodi  uf  applinl  vcieiicb 

Wtlla  all  enllf *■«—«<  Bhytlclm.  nitl  >Kr*ail>si ;  No  maa  In  Amarli-a  «*•  btuar  fItUd  Ihaa  Xtt. 
•kBairMu  or  phjiilr*  f*  df*lt>hln  (nt  llin  rnM<l>  Pn|wr  for  Iti*  laali  li*  uodenank,  and  h*  hM  f^ 
«■!  lUiteol,  nnl^  Ihn-*  w^iiiiiHir  *iiKii|t<l  to  ih*  (MM  Ih*  ■Isdtiil  Ka<  prarlltloDar  of  aitdl«ln* 
NMftlBS  Vi  l^>■  vdifiWT  itililKU  «au  ba  hilly  wllb  ■  ntuine  M  ono*  r—  <»lil»  and  llMniU(h. 
•  M  Ih*  ditllctililr*  ■eeauaUnl  by  ■uidaOM  Rtm  la  ihg  ■iii>toa(  <rtio  haaaom*  kDowUdptoT 
atumcl  l'i>  •tii<l)t  nf  ll>*>i>  mibjaou  wlltinitl    |.1i]->laa  tlil>  bsok  la  nHltel,  w  H  •hooii  Mm  tu 

■l>pli'4i.rinii  In  Iha  prnlWolria  iliai  b«  hu  ttioMo. 
Lir.  Urk|itr.  wuivid  Iwrobar,  kn«*  iratl  Uiailin- 
cuUlBatabauirvuaUnJ  la  brlDgliig  hi*  •w^*i?t 
nlltiln  th*  |i**p  of  (h*  aranc*  ((udanl,  nod  (hat 
b*  ba*  lUHwAdvd  lo  mfl  |>roT<*  oB*e  mora  thai 
Ih*  loui  la  sTlia  Ibr  aad  eiftmlna  aiuiliwil*  I*  Iba 
OD*  oho  ha*  tariKht  uid  l>  tMchliaa  iliam.  The 
b<0k  U  mil  prinlad  and  full*  IlliwIinWil.and  tn 
*T»nt  war  d***nai  fraunil  iweomlUvB.— n* 
VinlrcnJ  ValifiilJ'eNnui^Jnly.UMu 


a  hDOKlatqia  M  •llh'sr   idi)r*l«a  or  rhamidrr. 
Ttiaaa  ar*  npeclally  C*I1  by  lb*  laochcr  of  pby*!' 

Ifl*.  how*i#r,  tmpoaalbls  for  him  I*  Imparl  a 
kooalvdga  (4  IJio  main  ttcu  uf  bi*  BQl|]ac«  and 
•itebllah  lh*n  by  raauint  and  »|iarlni*aul  dem' 
vnMnlloo,  aad  at  ih*  aama  llinv  uodtrtaka  I* 
•MVh  ■«  MM)  Ih*  prld'-lii'**  <r 
■■a.  INuM  th*  daairaBilliy. 
aially,  for  •om*  »ueh  iroru 


•awh  at  MHo  Uicprld'-lii'rof  rri*tnl>'ry  or  phyi 

daalraBlllir,  a*   mar   aay    ""> 

>rlt  aa  th*  vraHDi  on*. 


BOBEBTHON,  J.  McGBEOOR,  St.  A.,  M,  B., 

FtlVKioIogloal  PbysiCB.     In  ooe  12>iiu.  vuIium  of  537  patica,  wilh  319  illiutn- 
liotiiL     Unii>  riolh,  SIOOl    S««  StiuUnU'  Stnf  ^  ^anuaU,  pnme  31. 
Th*  ItU*  af  thia  wcrk  lulDclnDlly  rip1*lfl>  th»    mxnt*.     It  irKI   b*  fouad  of  ffwtt  rmta»  t*  Ite 


■alura  of  iaa  iwntaadL 


STot  Iha  atadanl  ot  iD*dlrln*,  u  aiitillarr  lo 
lait-boaktnphyBlDlop.Bndltvouldbrpaniao- 
r  naaCUl  ■•aculd*  la  Ua  lahunury  aipcrl- 


tinullUanar.    It  la  a  <ar«Aill7  prapand  took  uf 
■       -     .^^_  ,„j  a*  ai'  * 


Tttinnet,  wooia*  and  Meanln,  and  *•  auob  <■• 
h**r(ltT  faoMamaad  ll>— Jmr 
Xadlaal  ^uaMan^DM. «,  U*t. 


DJXTOX,  jomr  a,  jf.  j>^ 

•  rinftawi  mill  I'       '  fit  (i '  ji  II  iki  QiJfjj* nf  P^Hrtaw an* Om'tm  u,  Vae  frrk. 

DooMuM  of  tho  ClroulstioD  of  tho  Blood.  A  KblatT  of  PhTnolo^nl 
OnJnluii  and  DisniTery  in  rtgnnl  l(>  l)ie  Circiilatloo  of  Ilia  Blood.  In  on*  hawliwDt 
ISbio.  Toliimo  ol  293  page*.    Cluth,  1^. 


Vr.  Paltaa'*«nrk  ltth*(rult  of  ibad'^prMoaruh 
•C  a  enlMfad  ntad.  aad  laibebuay  prvmionx  it 
aainMIUI  tab*  a  lourea  a(  InaUvciltni.  ti  wilt 
laapli*  Mm  irll)>  a  (Mllng  orrnillluila  aad  a<tiiilr- 
atlan  tor  thota  ploditlng  «nrk*n  of  ald-a  Uma^ 
who  laid  III*  (eundailan  of  ih*maininwnll«<n>pl* 
ef  raarilcal  (niaao*  aa  lts<fa  tlaod* Xa*  Otoau 


waa 


In  \h'  pn»trw  of  phnlolosloal  aludy  do  Ibnl 
u  oC  ftr*auF  momanl,  no 


nana  mora  potnplatfly 


rvialuUooliad  Ui*  UiaiMiaa  ol  uaehan.  Uua  Ih* 
di^n**rT  of  th*  elniulailan  of  tho  UooaL  TbM 
■iplalaa  the  •itraonllnaiy  IqImm*  It  baa  to  alt 
HMillFal  hlalottuu.  Tbo  (oliUD*  bafMs  na  la  taa 
uf  iliF«  c>r  four  ahieh  hai*  b*«a  wrliMD  wKMn  a 
f**  T>ar>  by  JloafteMipbnlcaaa*.  Illalnaaiaral 
raapeou  (bo  noiit  rompMa.  Tba  tDlaotk  ttMHsfe 
amall  )a  lUa.  la  ose  of  1^  n«al  MvdlHbl*  e**- 
IrfbiilloDatromaiiAmarloaapaMlotoa^kalbMoiT 
thai  baa  afvaand^Vad. «  *r«.  Xv,  Pact  *,  IM. 


BELL 


LL.  F.  JEFFREY,  M,  A., 

tnfiuo'  1/  ClMparafiH  A  anliiy  al  Klmi^t  OiO*s;  Laodan. 

CompArUlTe  Fhysiolon  UuIAdUoiqf.   In  me  t2mn.  volumaofUl  pafai^ 
trallona.  Iiis(iclolh,  12.00.    )ietSbidti»U  Stria  af  MaiKiai*,f*t^»\. 


with  S3B  illurtralloiia. 

TtkanaaaaJ  i*p«sCinlaaDily  aiitidnnt'ibook^    ll  lb*  b*M  •ark   Id  aiMaaea  ta   Iha  Eoaluk 
<l*ar  and  •tnsla  la  laDatuwo  aiiJ  uiaoiemaDL     laaaiuca  to  Maw  lo  lb*_baB>l*  of  Ma   uadlflal 
It  b>  W4ll Hut  aliaDdwiiIy  inu>ir>i*.l.  aoll* raad-  x ^HtM^-HfiM  M 
■H*  aad  iDlanailnf.    (in  th*  vh':lo  •«  an 


I  HtUto-CtHnryuM  JovMf.  Mm. 


ELLIS,  GEORGE  VINEBf 

Aamttw  Prafmtar  uf  ^-wIiMy  •«  I'tlvtnUlf  CUI«M  Iial'*- 

Dfunoiutrtttioiu  of  Anatomy.  '  Beinc  a  finida  to  iba  Raowl«d(«  of  the 
Htunan  Bodf  bjr  IKMactioa.  Froiu  the  eighth  and  nrtiad  Lnndoo  eilitlno.  la  oim  r«n 
kUKtaccuocUto  Minna  of  710  laffo,  «ilh  349  illmtnUooa.    doth,  M-^S;  laathar,  t&M. 

BOBERT8,  JOBK  B,  A.  M.,  m7j>,, 

Tbo  Compoad  of  Aoaiomy.  For  uae  in  tha  <ll»acHng^w  and  In  jircfiailog 
Jbr  anuiiinaiiotM,     f a 'joa  tSmo.  roluoM  of  194  (•««•.     Uiuf  i^MCktlb  wwa. 


i 


8  LtA    BllOTBtBS  &   CO.'B   PUBUOATIOII»— PhfBlOloer,  Vb 

CUAPMAJft  MENBT  C,  M.  D.. 

A  TrcatiM  on  Human  FhyittoIogT.     In  om  tuuHbrnne  otum  iii1«m  %I 
926  I>agM>  villi  00%  fiD«  cnipiivinBt^     t'loili,  ^VO ;  IcaUiirr,  IlkSO. 

11  iv|-rManU  •nr  ftil>y  Uib  *iImI»(  >ui>  "t\  fuih*r,>a4  ll»Ull*rwKI  i*<  •alctulOMml  . 
phyilology,  TM  t<r(HTal<i"irk  tiua>p*i:UlT>iiir  |  inFtniallan  to  u  k4nili*U*  b«oh  a<  taArtuM— 
Mtba  •ludpnl  >Dd  {'■'■'tlilont*  k>  dffoi^'l  »><>(* 
lo  1^  t*'*^''-^!  *p|(tlp«lLoD nf  vrll^kDOKn  Imlbi 
vhlrk  (tin  adtanr*  »!  •cioDO*  liU  (l*cn  Id  Ihs 
profrotloQ  tnih)«(lv|«rtmaDt,  nhirb  may  bomii- 
■IdrtHl  Ih*  (snDdallniKif  nUtiaiil  m#dli'liii>  —But- 
fii/u  jr*lifalaHl8iHfbnl  ^MrwILDrc.ltxl. 

Mitwrs  vlileb  haV*  ■  pnctlcul  iHarlniiea  Iha 
prvclka  of  Di^iKclnoAn  lurkdljr  *i  pr*H>*(l^  l*rh- 
DtM)  (Mllrr*  tn  k"'"  <»  mtnulo  dmll^  rlRbn 
tMa  dlr*«>ODi  «■  iiiiKd  fbi  ibt  BuldkDc*  of  du- 
dtau  le  Uie  laliomAry.  In  e»ty  ntpftrl  tlia 
vork  tUlfila  [U  uracnti*,  «h*lb*r  v  ■  rCiniplMa 
W<«llw  (»[  th*  »[iiii«nt  or  fir  lli#  pnr>>''>uii  for 
tb*  fwiD«r  II  I)  fo  romplrU  ihat  K#  aecd  Iwh  no 


.Vn'IA  OmrtUwi  Mtt^i  JoirvH,  X«t.  IWI 

Tb*  votk  nnali'r  rc^mVMl*  iMal 
■ludrnlMKl  i«*MIUoot'r.  VlwilvmeM 
lij-  ilt>  ptoamBln  phjralclu  of  l*4*v 
lullan  of  phjtlolu*  tn  pncUcal  KitnimiDn,  ud 
ihltwoTk  lta4Hlde4linT(*M*BBDllDitil>MMl 
mar  oltira  mtk*  In  Ui*  nurk*)-    ll  vUl  iiiJ^f 
Ink*  p1«o«  WDonf  th*  Boat  raliuhU  >»ii  tokfc 
Jfiifwl  Ajt,  Kat. »,  UR. 

ll  la  Iha  rrodMUoD  of  Ml  knlltM  «*lltliM4«llk 
hl>  Hork.  and  atria  to  laiidra  uu4*ala  BllkM  i» 
UiDiliuin  aklnlo  biiaa 
•nd  JVnn,  Ku*.  It,  Un. 


I 


j>jXToy,  jojry  c,  at.  j>., 

A  0^«atiBe  on  Haman  Physiologr.  DadgMd  fcr  the  luc  oT  Swdeoto  mi 
Pnctitbmera  of  MfdldM.  Seventh  tdllUin,  tli'^ixxit-ltlj  mvitd  ud  rrwrilMm.  lom 
Tei7  hftDilaooDe  ocUto  Tolumeof  732p*Bc>i"'i(l>''^^-l'<'""<i'iil*ncraTliinon«Md.  CktK 
>fi.OO:  iHihcr,  Sfl.O0. 

Fn.m  rhs  nt-t  ai'iicaranra  of  Iha  l>oafc  II  ha*    hai*  natar  baao  la  a*;  doabi  aa  to  UaaMrtMf 
tiavn  a  (ati^rirr.  iitnE  "   **<l   to  tha   BiKbnr**    aDith,— .V,  f.  Madlrol  Jawvoi;  OaL  Utt, 
iWDoirn  (A  an  I'lal  U'lc^rr  a>  lo   in*  cbaim  of       Piofawot  DMon't  nalMBMni  aM  4aBarta4bi 
almplioliy   Bliti    tIMh.  at   a  *rll*r.  h»  dviiyi    ipT>i*eUwJ  work  bw  ku  faaaai  Un  Migi  ii 
■UDi^ortlji     III    inii*iBllint   Bt*n  InlrlraN  *ubJ*rL>-       '-'■■-        ■  -  •      .........       .. 

ll  Riitirt  hr  (railfjinii  To  him  In  otBan*  li>r  fi* 
qiionpf  wtih  aMcli  hit  *ork.«rlll*n  (Or  riu-laol* 
and  itrat'tLIJtiB^r*.  [a  quotad  by  othar  vrllara  ou 
phfiuliifa-  Tbla  tiv'i  aiuau  lit  •atiia.  and.  In 
gfU  cn«M'ii»,  lt»  oriKloalHv,  ll  nof  n**d(  no 
■nul.  anl  i>(  ■|>pr<ib*tion.  hnHrtti,  (or  Iha  tbnn- 
■nnda  who  haTv  tiutllcd  It  in  lu  ?ark{iuj  aditlon* 


ipT>i*aUwJ  work  bw  ku  |._    .  _      .     ._ 

wliU-l.  ilouuld  ta  mi*«»«  la  lb*  onttuaj 

Th*  «Dtk  It  amlDoally  *••  for  tha  aiadtal  |n» 
IIIIoDar.ilDro  llmabunaalfBUjroflkoaahnMat 
of  pbyvlolocr  wlilrh  hara  a  itlreM  baarlac  as  At 
■llajjninl*  and  Iwialmaut  af  dl*aa*«.  T%a  WMb  K 
onewhieh  «•  eaA  blshlr  manwiaad  i«  all  lar 
CMd*r*.-i>abNajMnattf  JfaiMalfMaaii, 


r^^^ 


FOSTER,  MICHAEL,  M.  />.,  ^.  JJ.  «., 

i\tlnfuT  et  r^vituii/vif  atui  /''eI/i.ui  uf  TVinity  Ctit%is,  OiHA'idfi,  AflaiU. 

Text-Booli  of  Fhyiiiologj.  N«w  (ruiinh)  and  cnbrBcd  Ammon  fna  lb* 
£flk  and  rovicpil  Enctiih  edition,  with  nnln  nnil  additioni^  In  one  tuadaama  ucUto  tvt 
KM  of  about  000  |M|;«^  witli  olicnit  800  IltiismlloM.     Beaif  lao/fvitay*. 

A  RKVIBW  OF   THE  FIFTH  ENOLIBH   EDITION  IS  APPKNDBD. 

II  b  ittlicblfiil  14  nixui  1 1'—V  "lilcTi  ili-r>t«a  I  Ham,  and  hia  odmxIb* ara  mi  liittrct^  awij  aid 
only  nni)uallA*d  prmlti'.    m^Ik  ••vit.  I>itiiirlir(.>r*  I  d'lK'ii'mi'.l  nn  t«lty  aad  intld  ilttalW.    IUtw* 


D>.  Ill*  In  all  C'lwou an Idtal  iv>i-Ik>o)i.  tt'lili  ■ 
f^niplata.  Acf^racaand  dvtaHod  kiioMlddjt*  of  l;la 
Butijavl,  tlie  aiiilioi   haa    aiirciwdsd  in  (ilrlni;  a 

tboroujibi)'  «nna*riihra  aod  phl!i»<-'f>l)l0  arctitint 
tf  111*  tpiaupc  \  •tudrni't  ai'.-nilon  li  hapl 
IkKVChoul  Aitd  OD  tlio  iraai  aiid  lalli-m  4^ut»- 


t«lty« 
iri  i< 'atawbolawaan  jBKlllad  liaar 

III  lit  oBly  (harauahly  mot  l*«i > iil 

.ll  .,  inihaRoftUb  buu«c*.aMtMin 

l>  i.ii>liaj.l>' ttrf  baal  laii-boa*  la  nw  liaOMB 


m 


POWEIU  HENRY,  M.  B.,  F.  Jt.  C.  8.* 

fiia>Hncr  n  ptiptieleg^  Banal  Otttrntif  Surgttiuof  ITnuIand. 

HumUQ  Ph7>lolOg7.    Second  edition.     Id  ime  handKimc  jracket^st  I2auu««)- 

niM  of  60»  |.[>,  'itli  as  ilTowwllciin.   aott.tl.lWL  SmSiuitMt'  Stritttf  Mlammalt, |i,fl. 

8IM0N,  W.,  Ph.  J>.,  M.  J>., 

nVtHOr  (rf  Ctnntfrti  onJ  Tunfolon  m  iXt  OMm  tit  npiiHani  airf  Swytpw,  aalriBi*!.  ad 
~    '       r  (gf  CAwntlry  m  Ui  J(aryl«i4  Otaaft  1/  Aormary. 


Manual  of  Chemlatry.  A  Guide  to  Lertum  and  LaboraWrr  nark  for  BccioMn 
la  Cbmintrr.  A  Ti'itti'tik.  i,|HviBl1y  ni1aptc<t  (ot  Siiidcnl*  of  Pbann«n  nnd  Mtdiclw 
New  (•ocDnil)  nllllon.  In  »iie  fl?o.  vi>).  of  V,^  tips  with  44  woodcuta  nodT  oolond  {ilM 
UIiuiralijifE  56  of  llie  mist  imjiortaiit  chemical  IMU.    Qolli,  9^iA. 


In  thlatiaak  Iha  aiilhor  liaa  andaainra^  lo  maal 
IfaawBOtaof  (horiudanlofmedlolnaor  pbaima^y 
ba  raaara  in  hit  ohamlcal  nndlaa,  aad  ha  hat  ■iic- 
oaadM  in  pratoniliiit  hl**ubj«Tt*oo1*irl]rUiat  no 
Ona  who  rnlly  wHhat  to  ai*j)UTre  a  fnlr  IrnovHdM* 
ef  rliamlalry  ran  bU  Co  do  to  «IIh  ih*  help  (4  (bit 
nvk.  The  Uttttt  aaeilon  of  iha  book  ItnalunUIy 
Ibal  ittTOIad  lo  Iha  mnililiiiallan  <d  iha  rarhon 
eattpooad*,  or  organla  ehamlMrr.    JIn  d-vllrnl 


ftaliira  It  Ih^ 
(honni  ihe  '  . 
ohrmlfal  mi- 
nf  Iha  alkalDi<l> 


■  «ui^     ia  ( 


■  I   Ll.i.  ■jriii.ij 

pan  iiMtlagof  phytlolof  InU  rbanitCfyUia 
on  uiahvl*  of  Iha  iiilaa  «ill  ba  CMa4  *«I9 
eaJ,  ana  wall  •nliadioitaaaradaatilisimi ' 
of  inadielna.— TAc  JMKalJtMarA  May  «■ 


Wdhler'a  Outlines  of  Orgaalc  Chemistry.     Edited  farf  Firno.    Tnmlalal 
I7  lu  RkM8SE,M.D^  I'b.D.     Idoqc  12aic>.  vuliuueur&Mpagt*.    ClaUi,t3. 


LBHH«N>'«MA:njAL  OF  CHEKICAI.  miTK-   Ciftpeymt'SrillZB  IMATOIITnSDSBASV 
i£yS^U  )1JS'  "^^VJ^S^  "^  ""  ***"•'.     hwwoa  buHHUe  Umm  V  HaaLTa  aa*  Dte 

by  llasn  Poata.    '-■>»- "t»%n  «Aiiw.*.  > 


In  ana  oMaio  t^Aiub*- 


\W»ft.    YKfl^lH.   OlMb.VmWk. 


htK  Beotiibm  k  Oo.'b  POBLiCATioM— ChemUtiy, 


rRANKLAyD,E.,D.  C.L.,F.R.S.,AJAPPf  F.B.,r.I.  C, 


If  AMitt,  Itmiam, 


XDOrcAnfo  Cbontebrr.    In  one  hDndiom*  octavo  folnma  cf  0TT  f»gt»  wllb  £1 
Icuu  arxl  J  plalM.     Ctolh,  fS.TA ;  laathfr,  H' S. 


wDodcuti 

Tills  wwk  (Aoairi  iiiMrMd*  Mh*r  aarka  nf  »■  i 
«■■» la  III* imJIOiI cMUgM.  111! OMUIniT  bMUr 
•daplwd  this  Bfir  vork  DpM  cbanlrtnr.vldi  whleli 
«•■■*  KqiiniDWd, M  ImpHt  ihnE  «rakr  uit  (U!l 
ImowledB*  cf  Ui*  Htano*  ahMi  itudnnu  nrnwH- 
Iglua  ■bould  k«TiL  PliriliTlkiKWlioffvlitiaKbalr 
<h*nl«l  litMSleiln  H  tab  ID  J  iho  Urn—.  ■uUlU 
4ow«n  MMUdyihT*  work.  Tht  •iMerlpiloni  anH 
dVOWfuMMteDi  m  (Ddl*  n  plilo  Uui  in»n  U 
no  dUKcultr  In  UDiler>UD(l]D|  Ihvm^OMoiiwii 
jr<>r>«t  .VtM^  J««ufT,  Ittt. 


Thti  •iMllaol  trwtlM  «(ll  mi  IUI  M  Uk*  It* 
ptii«  gu  una  of  iTi«  xry  b*M  oa  Uia  autltcl  cf 
which  It  tmtiA  W*  )dT*  bMn  nmoh  piMMd 
vfib  lh«  rAfnjir»ii«nrW*  fend  liictd  nua»4r  Id 
■hiKli  lbs  dim'-ulii"  qt  eh«mi>>l  kvtaiIMn  Ha. 
D«a«iir]ftiur«  riArt  tf*«aclav«4  u|ibrUi»«rli«1 
II  ibuwi  iin  >iar)r  pap  tbM  lUa  tnblvmi. 
r*4-lrtlni(  (ft*  oMrurlil*'  of  lhl>  KiaiiP*  taiTJ 
of  MMnpivhandOD  ha*  1"n(  uJ  tiio(*>'full7 1 
HSMaiT  Iha  aitrDilMl  ot  I'la  t\iOuin.—M»hntt 
and&rf tMt  JBdwrUr, OctoUr  11,  IML 


jPOiryBS,  GEORGE,  Ph.  D. 

A.  Manual  of  Klemenmry   Ohemlstrr;    Thcorctka)  utA  Fnetinl.    En 
badlring  Watti'  PkyticuIaii'lItutryanieCYitmuln.   Now  Ali]cr;aui,rron>til»t<««lftk  B(l||IUb^ 
•dluoa.    In  oaa  Iuk*  roj^l  I'lbno.  toIuid*  of  1061  fiftt,  wflh   168  UloMntlou  on  wood 
tad  «  oobrvd  iilaln.     Clotli,  flTS;  leather.  t3.S5. 
fWnw"  fVnutni  hw   ii*«n   ■  lUQilitnl  tait  {  work  »  ena  ef  lb*   t*ry  baal  lait-booka    «p 


upon  rh^rnl'try  fof  manf  jnar*. 

*    "    '  ham  Ilia  kn<I  phfili'lAna 


•■MTanar*  la  tlil>  Muniry  auU  Id  Eaicfuiil.  Aa 
■ba  aslanca  baa  adiwioad  hjr  ilia  RiakiBR  of  a«w 
Jticct«rt w.  Iha  wofk  ha*  haon  r<»l>''l  ao  a*  is 
kaar  U  atin«at  cf  Uia  tlln*(,  II  baa  tl*a11lT 
nalDMInad  l«i  poaitlop  aa  a  Millxwk  wltb  majl' 
olaludanU.    InUilawnrkara  ict<iI*iI  FiiIIt:  E)<ai, 

uiAlMMa  alfttad  t^  tn-r*  fvnii  in  rli-mlntl 
MItMnpM  baaUb  and  dlaea».alc..1i  ofth*  inwl 
iMpecMI  klad,  aod  abouM  ba  nunlllai  In  trtTf 
"'  '   pnwUUonar     Wa   oao   oommoDd    Iha 


lamotlU    ebamlttnr  •itaal.^O'HIaMn  Jfaf.  JirtiM.OM.11,1 
or  all  Uia  worka  on  vtiamlal^  Int^ndad  lot  Um  4 


aaa  oC  inadlaal   aludmU^  Fi>iaa«a'  C^tmuttry   '_ 
parhap*  Uia  mual  vldalr  aai-L     lu  ponulailiy  h 
baaad  uddd  It*  avntlan'W,    Tlil*  la*t  adlUoa  cdl^ 
tain*  all  of  lbs  naaarlal  found  la  tha  nnitou  , 
and  11  laalaaaiirb)b>dlv(>»«^»lom«r  WM0  ' 
Pkmtal  and  /«rinnie  Ctinitlrt.   Ail  gf  (ba  mat-i 
wr  1>  hnu|b(  lo  Ilia  praaaal  ataadpcdot  ef  <ibMnl*'l 
raJ  Imawladsa.    Wa  may  aafaljr  pndlal  IW  UiMJ 
■iiik  a«on(lnaaiuworUiefMtiaaad  k*or  11  vBlof* 
amoDS  madlcal    alDdrola.— Vim  Oiaaaa  Jlfamtal 
I  ntfAvBleal  Jnumol,  March,  IHL 


ATTFIELD,  JOILN,  M.  A.,  Ph,  D..  P.  I.  C,  P.  R.  8.,  Etc 

Chomintry,  Gonoral.  Uodicsl  and  Ph&rmBoaatioBl;  Includioc  th*  ChM^ 
iMiT  cif  the  U.  8.  l'l]iiriTiiii-i>|xrin.  A  M.iii(inl  of  ihe  Oncrml  frinciple*  of  I  In  nnifO, 
■M  their  AfiplicBiioii  tn  Molidnc  nml  I'banii.-icT.  A  no*  Atnoricui,  tmta  Utr  twilftli 
Bof  tUh  nlitioii,  apNinllr  rKviMvl  ly  iha  AuiIi't  ftir  Amfrlcit.  In  on*  hoBilaama  rojftl 
UDO.T«Uiin«ol7tt2iiit[WS  withlUt  illuttratioiui.   Cloth,  tS.TS;  leather,  t3-^SS. 

AUflald'i  Ohamlatiy  la  Iha  moat  p«p<itar  honk 
MIHHiB  atadaala  01  iDadlolDaand  nhainacy,  Thli 
popularlly  hat  a  (ood,  aobauoilal  laalt.  It  raaia 
nioD  mat  iDarlli.  Aitnald'awork  comblaaala  Ilia 
bapplaal  manB>r  a  <i*Bi  kiikbIiIod  of  Uia  tbaniy 
Otanamtairy  wllb  (ba  iriFllcal  ■pptlcailin  ofihia 
fcDOwladna  lo  tlia  afat^day  daalliiM  o'  Iba  pby- 
ateiaa  aad  pbarmuliL  HIidlKarDimal  liahowD 
est  only  lo  what  ha  pula  IdM  bla  work,  bul  alao  In 
whal  hfl  iMTaa  oal.  Kla  bnok  la  snclaely  what 
lbaUUaelalDu6>rll>  Tba  admlnblaamnaiaant 
Of  Um  Mxt  >e«fcla(  a  rvadar  ia  ^al  a  pwd  ld*a  of 
olMnlaUT  wllhmt  Iha  old  cf  •ipanineDli^  and 


a[ain  li  )■  aanod  InbAralorT  ti'da,  and  Knal^ 
roDtAlaa  auona  maatof  wvirarnAcad  iDfortnatli.  _ 
thai  11«lllalwayaaarT«MabaQiIybivk  ot  nttt- 
anor.  Ba  doaa  DM  allow  any  uauUlliAl-ia  kiiawl- 
t4f  la  altn  Iota  hia  bonk;  hi*  Idiir  y*ara  •<( 
riparlaQca  ntTo  prcducad  a  v4Tk  vbicb  t*  both 
•elautlBfl  aad  practical.  hikI  uliirli  altuu  ool 
afarylhlns  In  tha  naiilra  cf  a  ivupariluily,  and 
IherrtD  I1«*  iba  Mi-nl  nf  lla  aunWHk  ThU  laai 
adltlOD  aliowa  Ihrt  mark*  ot  Iha  liMal  pMCtaaa 
madalneliainliKy  and  ebamical  Uaetilac.— A* 
Orlfoiu  JfadicaJ  aad  A«vial  Jotmtal,  Km.  Ml 


BLOXAM,  CHARLES  L., 

Fntfitwr  ur  <.^^rvl^tfTy  ■■  Kutifi  OMtft,  Ijrtidoit, 

ChQcaiBtry,  Inorganio  and  Ori^aaiQ.  Nvw  Amerion  from  ilie  fifth  Loo* 
doa  cdilkiQ,  iburougliljr  rcriK-i  ui>t  mucn  improTciL  la  one  vctj'  bontkaUM  octaro 
vdUMof  1k7  ftgm,  with  -i-i-i  ilhwiniiioEw.    aalli,$i.OO;  Imlher,  (aoa 


ftwnKBlftnW  «■  CO  thla  -I'mUM   anik 
*««l Mfaraaoua,    IlOllknwIUrly  In  ac<>j>e  aud 
alD  fton  IliM  of  AtlflalJ.  and  la  lu  ■«•  b  atjually 

aondoMtclani.  Iia<l"[>u  Iba  mini  diml  nialh* 
la  •latlnglhr  iirlncIplaa.hypHlHata  tod  bti« 
Ot  (ha  aelaoM.  lulabHuaR*  It  an  Ian*  aodlncld, 
aod  It*  ■rrauaoiaal  of  niallar  ao  lo^lcai  la  ao- 
Bea  Ihia  (h*  atudaot  naitr  baa  unaflan  lo 
a  Ihat  chamlaUy  la  a  hard  atndy.  Haeh 
il*  foU  ID  aaparUnaaiAl  Uloitratloiu  of 

1    pAnvlplaa  and    ptiaoonaDa,   and  Iha 

»afCODd<ielinB(boaaaiparfnwn(*.   Tbabook 


mala lalaa  Iha  pOalHoa  It  haaalwija  bald  atUtaW 
Iha  liaat  maouala  nt  aaneral  cbanlalry  (a  iha  Mtr 
IM>  lanKUaaa.— i>rtrbi(  tatett.  Fab.  IWt, 

Wa  know  d  bo  liwaxt>a  en  cbamMiy  whioh 
«fintatBa  M  niub  innlnl  laSanaaUaa  In  (h&, 
■ana  Duaabtr  ef  pMaa.    Tlw  bask  Can  bo  ri 
adaoud  BDl  only  lolho  DOoMof  Uioaawho  c. 
a  Mhrably  eoniplalo  cwiiraw  of  ahanditiT,  tal  i 
•0  Iha  naaib  of  Uioaa  who  ilaatra  oot*  a  nu 
kwirtaiteaorthoaubjatt.   Illabalhai  ' 

taitbooE,  and  a  uaonil  btok  of  rafanai 
Madiral  i-d  Airjwaf  J^ivhI,  J  vaa  1^  tWL 


GSEEyE,  WZLLIAM  H.,  M,  J>.» 

Dmmutratvr  tf  OtmtU&y  ta  IM  Jtfadiasl  O^ptrMaal  tf  (M  Paliwa%  of  i^ililnala. 

AKanualorUedloalChemlsbT.  Fur tbeDMoTSiadntii  BMadnpeaiBov 
nan's  Utilitnl  Cbemulrj.  In  one  lano.  Tvlutue  t/  SIO  pagMt  wtUi  74  lUiu.  CIolli,  tUS, 
tllaanoeUa  maniia]  of  thra*  biiadrad  pMaa.  1  Ibo  tveofotliaa  of  otapenada daa  lo paUioloctral 
■lilMaa  •uallani  aummary  of  Iba  »hI  naUwda  ooadWona.  Tha  4aMaUM  of  poUoo*  U  Irtalad 
SfHBjMBiibalfqiadaaailaalMaotlkabadr.hotii  with  aanUval  Minsao  tor  iba^purwa  of ,tto  aau- 
Af  a*  atlwafif  «/  UaOr  aormal  eoDMiliioal  nd  ,  daMM  f«tMUMNnr-V*teK  It.  •i(Q«Bk  1 


IiEA  BaoTDEM  Jt  Co.'b  PuBLtoATiotrs — Cb^nilAtry. 


JtSMSSN;  IBA»  M.  J>„  Ph,  J>„ 


fiimlplea  of  ThsoreUoal  Obomlatry,  with  nwcU  nrfemm  lo  ik*  CuHtiUh 
1  of  CbnalcalOiBpoUDdA.    New  (third)  Bod  UiorDUgbtjrroviMdadlttoB. 


■OHM  rujrnl  liam.  TolunM  of  3III  pagw. 

Tkl(  Kork  of  Dr.  Bvlun  ■■  Uw  *«]r  IciVtMnk 
Mcil'd,  KBd  Ui>  ia«<lkBl  >liicl*ol  i>lu>  hu  K  ■( 
M*  ODsm*  (oilaiM  la  uuwk,  aw,  U  ba  elMiao. 
Bkk*  almHIt  biDlUu  wllh  Miy  bnui(>h  ot  oham- 
lalTT  ahleh  )iMB«r  ilatln  lo  puiHi*.  11  ■vuld  be 
dinfouli  Injtad  to  fluil  •  mots  lucid,  full,  kod  M 
Uwiana(lnt«roifipvi  aaiilJcvUun  of  ilio  plillo*- 
•pbr  OttfirlDltliy.  UiMi  Ifie  lx>i>li  bcfut*  ii>.  mid 
Vtt  racoaunaii(S  it  to  th*  rmrnfiil  ^bd  Iini«ni»J 


Innnahaod- 

«IUllBUMeOl<»llt«b«l1ll«Hf*<  MtMM^tf 


(iosl  Jnnal,  Jwinwy,  UM. 

llt*khMlthfDli(ca«kH**iHa4anud  Iv 
■  third  (dlllPBbftuchaboek  •■  Ikta.  Tlitoi*^ 
tlon  to  IftTEH  Ihao  til*  l»i  hy  aba*!  «*nnif  «•• 
Haaj,  and  much  ef  li  ha*  bVMi  mrtftfa.  IM« 
btinglag  ti  tiitir  abr*Ml  af  the  IMhi  laraaaWb 
Unoa.— S,  "   "  ' 


r.  jr««M(  /owmI,  Dvc  ■!,  IMI. 


CHARL^H,  T.  CRAN8TOVN,  M.  J).,  F.  C.  8.,  Jf.  A, 

^brmtrly  jHl.  /Vof.  mt  Daawut.  qf  Olfnii'I'v  wl  C'AfMltal  Fl^la,  Qwva't  f'trirr.  J 

Tbo  Elements  of  Pbystologlcal  snd  FarhologiatI  OhtmiKOT*  -& 
flnnillnok  (»r  MedicaJ  StudeoU  aAil  Pniriiiicnim.  OiDUuniiig  s  |tm«fml  KiraiM  of 
h' lit  rill- .01,  {''inhIi-  nnd  Diipialinn,  and  the  CliPDiulry  of  tli*  TiMtiM,  OtxMu,  t^ttMliomaai 
Kicr«<iuiu  iif  ilip  B<«ly  in  IImIiIi  kikI  in  niMiim.  TogMh«T  with  ln«  mctbod*  fcr  pt^ 
pBciag  «r  aciKraluig  Uwu  cbivT  inniilitiiciiU,  u  «l»  Tor  thtit  aTnmlMtyiai  !■  daHil,  ud 
MoiiUtiMBfUafauaofmnwaickleDnraeofiiMnictieaferctudraU.  In  on*  h»i»JM«D»  ottew 
volniM  of  468  pa^M^  with  >8  irondcuu  and  1  colored  plttt«.    CtaUi.  |3J0. 

Dr.  Chwlaa  In  l\i\tj  Impriiaid  wllti  Die  Imnor.  I  nowadara.  Dr.  Ch^a*  haa  lUaoMi  ■■r>  Man 
tanaa  and  (invUall  raoHi  a(  lila  lublHl,  wid  IiB  I  to  tlia  oludUallen  at  nrlaafT  Walatlaft  B«  aam 
tiHtrHiadUinaeompBlaatanilloalrurllTa  R»a-  thli  lakh  oiiioh  drlall.  lad  nt  la  •  fnMlatf  ••« 
wm.  W*  caDiipl  (vominaiid  a  bKtrr  book  Ihmn  lnt»niRllil«  nuumer.  la  Ate^  tM (aliM*  lM> MM 
tliaprr*«-iii.  In  bf4,  U  Allaacap  la  madical  (fii. 
bODtn,  and  Uiki  l>  a  liilag  •liivh  ema  ranly  b*  (aid 


IntMIlRlMi  ^  _     __. 

hla  look  alih  maoy  naaUcBl  Ma«a,  ■, 
■rd,  bv»ln>>ar)i\  IBM. 


nOFFMAJf]!ftt^.tA.M.,rit.l>.»  A  POWES,  F.B.,  Ph.D., 

AUftnual  of  Chetnlcikl  Analjii^-Mkrolicd  uUm  Exanufutianof  M«£dMl 
Cbanlcab  unl  ilicir  PrriNitstioiu.  Bdiw  ft  (rtiliU  Rirllic  Dolrrmiiuuionor  thatr  IdKlUf 
■nd  Quality,  nnd  fur  tha  Daurtloa  of  IdiimtIUw  unci  Ailntipnlkoia,  For  lh«  vm  m 
Phamadit*,  PbTriciaiu^  DnioiMs  and  tlanntacWring  C1ieBiL'>ia.  Mid  PharaaceirtitKl  wd 
ibdfaal  StudoMa.  Third  edition,  «iuir«l j  rewritttn  and  miidi  cabrnd.  la  oa*  *«t 
haodioiDeoclaTUTotiiineof  m  ptfita,  with  179  lUncrlratiocu.    Cloth,  tuS. 

Wa  wDOalulai*  tha  aiiihor  on  Ui*  apiaaniBn 

it  IhaUiltdadllloaariliUwDTk,  pabtMiadforllia 
nl  Uma  Id  ihia  (miiBlnr  aUi,    II  laadiwlrablaan.l 
tha  iDlinmialioa  )l  nndvnaliH  to  wppl/  la  both 
•ilaorin  and  tmMwDnhy,    Tba  aalacOoa  of  pn> 
■[nine  U>a  puflU' of  iha  nhalan. 

"   oil 


I 


tfOrdaunBlDiBC  I 
eaacf  *hlqh  HlnaU  UooIUatud  Ihadaaarip- 


llou  eT  ttaam  ulnituUtly  air*l°lt-    Ua»«m,(|> 
aE<4pll<inAjJy  fiM  frani  IjpDf  raphtc«l  arra^ 
hai>  aa  btKllailea  In  rvaommandlu  ii  u  T 
■ho  ar«  vDffMKd  bIiiim  in  tha  laaaiuSMarBoti 
iMiInNPf  iiadlcln*]  «baBilCftlL— .£•■« 
caatKoiiAiwwlland  Trtmuiittamn,  UB. 


nl  In  tha  urAirniaatfa  of  a«cb  iaal; 
>  elianiDWrlaUe*  ara  iirajirra^  la  tha  n* 
A,vhlrihvavBn  baafUly  f aPaanaaanJ  aa  i 


CLOWES,  FBAJfK,  X>.  8c,,  Ltmaon, 

An  SIem«atar7  Treatise  oq  PrAOttoal  Chet&uti7  and  QualUatini 
lOOrganlO  Anal]^.  .Sivcinlly  ■daiilcd  for  OM  in  the  Ijdnnaarica  of  Retook  mII 
OoUogca and  bf  Bagiimcn.  Third  AiMrieattfroai  tholDunhaad  lariHil  Engllab  ndlltaibl 
In  DIM  ISmo.  «oUiraa  of  !IS7  v^gt*^  with  tA  illitalntiaiw.    Cloth,  92,iO. 

Thla  arark  ba*  loaa  bcvn  a  hvorlM  vlth  Uboi» 
lary  lBam«to»  an  a«Duni  at  lla  vMcaiBlle  plaa, 
<*rrrlac  Uia  Madaol  (Mr  *•</  t\tf  bom  tbaalnplaal 
Dnaallan*  td  phHnloJ  aiialjrpu.  U  Iha  mora  ranni- 
dUa  bfablama-  fiaium  «Im  ■*  (ommMidaMc 
Mr*  tha  r*«ularii7  and  ar*lan  d*aiau<l*d  of  l)i« 

RALPE,  CHARLES  lt.,~M7^., 

Aitubnt  Pt^tvutn  at  tU  Ionian  HotpUoi. 

Cliniost  Chomutry.    In  ooo  imrkaf  !i«  l^oiu.  tdIiko*  of  314 
UlDiinliont,    Llin]>  dotJi,  red  <dg«^  f  1.60. 

Till*  U  aaa  of  Iba  moM  ta*im<HlTe  tltLla  work* 
■hat  aa  l>*ia  nial  wlUi  In  a  lunt  Udib,    The  aLiilioc 
i>  a  phjalctae  aud  uh/dutoilal,  «>  mr'A  >•  a  rlirm 
■•i,<«n>*iiu>aU>  Uia  li«  '    ' 
neol,  lalUn;      ~ 
ftsaw.af 


aludiml 
ThoMcl 
•dlUOB,  

Irthmorr  ■uldafoiiha-wdaMoriMtMala* . 

leal  aoalrite^irw   ^ar*  JVaAmJ  jMn«L  0«  % ' 

utm. 


F.  R,  C.  P., 


I'Tf' 


•mH 


■■cue  auu  un/Huiogiin,  «>  iCii  a<  a  riirni' 
*i|U>aU]i  Uia  book  l>  Boqaallllailly  inaa- 
Una  lb*  nhyalalaa  loal  ■bal  ba  mtgM  to 
r  i£a  apprieautiiw  «t  ebamlrt^  la  toadl- 


Sm  Srwfml/  Sma  of  V-tnttaU,  paga  U. 
elua.  Dr.  ttalfc  la  IbWBUBhIy  ao^ualaMd  «U  Ika 
laUKt  oDutrllialhii)*  10  hk  af'l^DI<>.  asd  li  ta  atM 
i*rrt*hlna  to  And  Uw  anbjaoi  <iaaH  wUli  ao  «mmv 
and  Blmp^,7M  laanohoManl  I 

,  modam   tDlanUfle  nMteda 

I  JiHard,  PatmiT  1  IMi. 


inl  hatwoM  "U  ** 
and  apwC    »»«■■ 


CLASSEN,  ALEXAITDRR, 

Elementary  QuttntitatiTe  Analysis.    TmulNtol.  with  notaa  and  aildilji 
EuQAit  F.SuiTii,  Pli.  Ii„  Avittani  Profmor  of  Cbemiatr;  in  the  Town*  Bci«Dtific 
Ui^T«n)lr  of  P«t>in.     Id  one  IZmo.  volume  of  334  imgtm,  wilh  S6  illiu.     Cloth,  fS^W. 
It  la  |i(«b*faly  iba  bulBiaBUklof  •D*I(irnilar7|  aad  (h«a  *dreR<-lniialhaanaJ7itl*of  BlMankwi 


ona        ■ 


OMOi*  aitaM.  iMomiub  aa  Ua  m«tti«4k  •>»  Mm  I  anah  pN>4Mt»aaat*  nial  *IUi  la  upHad  (toM* 
baL  It  laMtM  kn«SMnD)«*,«MitntMiC\ii%<inih\«j,  \\  \*  «b\b«!ag«awaMa  fcMk  fcr  aaadaMak 
ala«la   dMOfOtlaaUMW,  nnm*4  tor  »>;■»»»««».',  AaWi*ir|^»a«to.J"-—H  '»ii*nr».Oa^Mi 


LiA  ItnorHuui  Jt  Oo.'8  PnBLiOAXKWB— Ptukmi.,  Mat.  Med.* Tharap.  IT 


I 


llAHE,  HOBART  AMOBY,  B.  Sc„  3f,  !>., 

IVni'no'    nf  Vnfiril  JTHiAa  Ao/I  nn-tpii<. fxi  ■■>   It*  J-frrrt^  J(>rfiA>r  n^llffo  "f  PidnnltlpiMi 

.y4ftJ^-v'f  n^  (Vi.i...i...n  fi.'H*  AfTu«->i'  r*«  f;-.>f«i.v6«i«i  nM-*>nr.,>ai ^  titn 
A  Toxt-Book  of  Friu)tiO*l  Thorapoutio*;  Wiib  l-jit<i>cul  IMcmM*  to  tli« 
Apriintloti  of  R^ninJia)  TkCtuMir**  lo  IXkvnM  unil  iImit  ECniiiioTmrat  upcni  ■  ItMlooal 
bM&  Wilh  ■pc'UI  cliat<ii-n  ti,v  Dim.  O.  E.  De  8cniri;isin^  Rehcarp  Mariim, 
J.  DoWAlUt  RitevM  ami  Baiiton  C.  lliKn'.  N«v  (3d|  loJ  rcrianl  rdilinn.  In  one 
biBlaWM  ortaTO  viiliiciie  <•{  ^M)  |>*|c».    I.'ldb,  (:{.T-V;  Icnibcr,  $4.TA.    J<y«  rHwfjr. 

Tkl*  *wk  liM  NKWlrvit  Ih*  rar*  illitlaAIInD  niliar  iHliirM  at  Uil>  pfMilcal'*  Iwl^l  lr*alM» 
■omOK  MwJItwl  <'aft»<>if  r»»»ililnK>  iMnndrtliltai  I  irhlrh  «lll  mak*  raOnni*  >a  It  npfmlaai  t»4 
•li  modili*  ntUr  ll>  llrM  k^petiwio*.  W*  sola  { ■•rotlubtB,  an  Ui*  wnu«*n«n(  of  (UIm  «<  iliuc* 
■anoDBths  IspvrtaalK**  ftoluf**  ckancterlMDi ,  >n'l  iIImbch  In  ■IpliBbeilcd  criIh,  ■BConllBff  <a 
tl>a>M00ilnllllan,ul4lilani>lluhrai»Uiian«Hi<  ,  Uxlr  l\niili>)i  niK»Mi  Ifct  lairadMllm  a(  Ih* 
tks  iha  nmvdlM  r>v*aUr  ■<l>l*d  to  (ha  Mki>H*  pro  pant  loi.'  <Jthe  Rrllhli  riinrniwic-piiilk:  aifAw 
Hadkai  Ih*  mdlioa  «l  •mpI'VlWt  IM  MM  rnrai  I  llM  at  4Tnf*  altlclnal  mad  -ranfflrtna).  la  ad<ltlK« 
Uin  UH  or  Buiu*u>iau  Id  Ihu  usalounl  ■>(  looBmik-  I  b>  ili*  cfaanl  ladei,  a  hpIodi  uiiiI  aiiiiuttAfy 
IM  alalia  Had  oIIIhI  ■fflrcllont.  Uioy  ii*»  pr»-  In^m  tftdl»WMMi  'r«iiwJW«hM>M«apf  laiii 
MrlHloni  kat«  a)««  bMD  lOMrtvd  lo  IllaitnW  wMi'h  wiW  nndttt  Iha  ooDtaaU  vtdljr  ftiwIMfc 
iba  Mil  tnodu  <tt  aiiplTtai  r«ina4l**.      abmik  I  —TV  JVonm'  iIjk  Jiilr  In,  inL 

HARE,  nORART  AMORY,  B.  Sc,7~M.  D.,  Editor. 

A  8fat«[u  of  Practical  Therapentios ;  By  AmiriRui  an<l  I'r^rflKn  Autlt<>n. 
In  A  Mrira  of  ranuilniliiNW  bjr  MTviitj-vercn  ciaiii«nl  phjiuiaus.  In  three  uncc  wUto 
tDlotDBa  of  abcul  1000  pag«  Mch,  wilh  Uliwlmlkina.       For  lalt  by  toAtrripiBu*  mtf. 

BBuyroy,  t.  lauder^m.d,.  d-Sc,  e.r.s.,  f.r.c^p., 

A  Tflxt-Book  of  PbarmaoolosTi  Tberapontioi  uia  Htttaria  Hodio*; 
bwhidiutlM  riurnucj,  ih«  Flivuuloctnl  Aeiian  »Bd  th*  TliarapMUu)  Uwaof  Dnin. 
ThM  «duioii.    OoUfo,  1S0&  pa«««.  &ti  Uluairaiiow.    Qotk,  ^Uft;  iMlbar. 9A.NI. 

Ro  mrda  of  pralM  an  Ii**dt4  tr<r  IM*  «aili.  Iter  i  mad*  la  tarlona  dliMIHiia*  la  Ik*  an  «r  thawpaw- 
II  hai  alnadr  (IH-Iifn  lor  ilatUlii  fnrmar  ■^iUoni.  |  Una.  lod  II  vowvlandiiuiufnllBd  Ih  IU  IliotoiiChiy 
ll  •*»  by  unaolmout  «otia«>l  plB(«d  amoni  Uia  tpltnlillBpriaiilaliaaMthamodPtof  ira* awloo. 
fDrvamI  l»«li>  on  Uu  miI^ImI  (tot  pabllahad  la  Ho  on*  wnn  olaha*  in  b»  lutlv  ii»  M  th«  flmfi  ti 
laj  liTfitri.  an  It  1^  I  Vttirr  Itli  fcn  rrni  *ai1  iiiirtl»4  r  IkU  nclrntw  taa  mati  U  atcki^l  tha  atady  of  Dr. 
(ka  a«M  nlahlj  II  la  ifiprvoUlad.  Th*  praaani  i  BruMon't  ■ork.  TW  lodaia*  ara  ai«allau(.  aail 
•AUoa  coaMtoa  tnueh  naw  mallar,  (ha  1am linn  [  aiM  bdI  a  tlilla  la  (hs  pranltral  faliM  of  th*  baak. 
W  ablch  hw  baao  H«aMlta(»d  bjr  (ha  a>t>ao<wt|  — Jtah«l  ffmnt  May  »,  MK 

MAISCir,  JOONM.,  Phar.  D., 

A  KftDUal  of  Organlo  BCMerla  Hodioa;  Being  a  tiuid*  Lo  Maierii  Madica  of 
Uic  VcgeUble  mk)  AninuU  Kin^laiai.     For  (bo  ii*o  of  Sluilniu,  DnMgpM«i  VhttwMiSalM 
■nd  Phjitciaiu.     N'a«  f  4tli)  ailltiDii,  llionHtghlv  r«TWI.    In  on*  IwaiMcinM  n^*!  ISmo. 
of  J13»fiBKW.<itlliZ5i)Uliuiu«Li>ana.    ClotK.IS.U^ 


wlaaw 


'h>N*iiua',  nnt 


^      .    Ialartalf4   la    malaria  nadlcia, 

>lai*!h1.»l»iiu»1,  - 

to  lu  faurtli  odu: 

For  Iha  Amarioaa  pi ^ 

■hanitkahlrhirfll  tlf  hlmlhaptmaafj  kiHl 
MMlalfcaaMlHl*a;,H>rU7bwaiM*ll>*l>it  l> 
in*C  naelM,  and  IVaa  tram  aonaeanaiy  nMi '-  r. 


t.ua 


nnt  uublUhad  U  ua  and  dob 
ilaa,  la  aa  lodUpanMNa  book. 
■  phanna«aa(leal  ttndaat  ll  I* 


Bd  pamr  kanuM  of  (ha  piimarKM  (lliiMnlkiia,    I'lali 
■kini  brloc  hull  wnith  knoalac  ImnMlaialr  b»  j  UKL 


tuta  hki  Bjaa.  Tlial  UaaannlUporraaaalDUila 
rwHCI  UM  raplil  auMoulaa  af  sdUion*  it  Iha  haM 
aiMmt*.  Iibitafanruabaaksf (IkaJliDarliaa 
atDdani  bno  anlil^  at  MalMh'n  Mfvnl  biiii4rt>l 
;<»r«nial  Mu4«Ma.  TVa  anancemanl  at  lU  n*" 
tfaif  ihDin  Iha  praatlfal  vtoAaef  of  Iha  baalL 
Mululi'*  •TMam  of  olaatlAcMlaa  It  aaqr  aadMOi- 
it alianatra.— W »n»« imHm l«  tonutt  OWMJ. 


PARRJSn,  EDWARD, 

LaU  fVaAu>rc/  Uj  VuBrnml  Prmhftf  t^rmn^  1^  t\t  PltUuMplit*  QMm^  ^^rmart^ 

A  TreaUaa  od  PhArmaay:  Dad^icd  ■•  a  Tut-book  for  tfa*  Sradnit,  hkI  m  ■ 
Oniilc  (or  Ibo  I'hjriiicino  and  Phannaraiitiit.  Wilh  mnay  Fonuala  ukI  Pnacrlplkm. 
Pinb  •lliiuo,  tlioToiidilT  nriiiol,  \yj  Thumab  S.  Wubakd,  Plt.O.  In  mm  handaonM 
ocUTO  TohuQC  oT  1093  Jftget,  wUk  856  UlortnOJoBa.    CliiUi,t&Oa;lNlber,  16.00. 

oda  of  aomUaalloD  ara  «««**nitii,  oaa  tMmi  la 
laan  thia  vorH  aoi  of  lb*  IIM  of  UiaU  itArka  «f 
(vCifVDOa.  Tte  ttmttWf  MapUUf  ar.  alia  bum 
almin  h*  >b  a  maaaara  hb  ovn  pkatVaanltL  *ui 
Had  It  ladl«aan«ablaL  Xaim.«M  MMtaal  Jhm, 
HarehV^ML 


Xo  IkonniBb-flalDBpbannaolM  «in  lUI  lo 
hlmwlf  et  to  naaful  a  pilda  M  praelloa,  and  do 
ph)i>i(^UB  who  praparlr  ■nunaiM  Ilia  talnaof  an 
anrunia  kBoirlBdcB  of  Oia  rrmaillal  afaala  om- 
pl«X*d  bv  hlo  Iq  dall*  praMloe,  an  lar  la  Ikair 
■latlMlltjr,Mm|M>ndlltr  aad  niaaiallMUtaiDalk- 


BVBXAJrX,  J>r.  L., 

l\tfmivr  of  nytwlm  i>  lU  Painriffy  tf  2WwA. 

Sxparimeotal  Pharmaoolosy.  A  IlaniUirak  of  Ustboda  far  Pwaralalm  tk» 
Phjrtiologiol  Actiona  of  Dnict.  'nuMlotad,  with  tlia  Antbor'a  paraWo^  and  will. 
WtunalTa  addltlona,  bv  Rosanr  M  bamc  Siuth,  31  D-  DamwiwnUoc  of  Fhmlolan  in  lbs 
Unittnitj  of  Pmio^rlmila.      12nia,  IM    pasta,  with  33  iJliutntiona     Clolb,  91-Ml 

STIXlA  ALFRED,  M.  D.,  LL.  l>.p 

Tharspoatic*  KOd  Haurla  UediOL    A  STMoualio  Tnatiiaaii  ika  Acikm  and 
Data  of  Uedkinal  AxcdIk,  indudinf  tbalr  Daacriptioo  and  Bidorr.    FonitU  adlUom 
fmtimd  Mill!  faUmit.     In  ttr  luprt  and  hilHlTWiT  TntliTTi  TrftniMl.Trti^iVTi^TT.'^''^*' ' 
OoUi,  910.00:  /wibor,  |12.0(f. 


BTZLL^,  A,,  M.  J>.,  LL.  J>.,  Jb  MAISCH,  J.  Jf.,  Phar.  D^ 


#t  lit   P'-irviay 


.    _     .     MloftMT^iOTJfraj- 

Hh  <if  iri>tMH  oaJaf  OtMMt  JTtMMH 


The  National  Dispensatory.  | 


COMTAHtlMO  THEKMWRAL  HISTORT.  CM£M/ST/tT.  PUMRHACr.  ACTIONS  AMD  VS£S  »F 

MSOICIt/ES.  IKCLaDIMG  THOSE RECOGKIZED  IM  THE  PHAHMACOfailS  OF  THE 

OHfTEO  STATES,  OHCA T  BKITAIH  AHO  QtHmAHT.  WITH  UaMEROVS 

ttEFCSEHCES  TO  THE  FREHICH  CODEX. 

Fourth  tditioin  rrvLMtl,  aii'l  (v>vcniiKll»  new  ISriliili  IliruuiMopfcia.  In  oat  mtf- 
nificetit  impcri&l  ocMto  rolume  of  I'M  nigot,  trilli  31 1  tlabonle  wiKravln^  Mr* 
Is  clotli,  f::^^ :  Imtlicr,  rabed  bmtwU,  S8.00.  \»Thu  mrli  vUl  bi  ftrmuiul  nU  AUrM 
Baidy  BfferertCf  TKumk-Utlir  ta^tx  fyrt\M  in  adddim  la  tltt  print  m  amy  ily/t  v/  iMmf 

dUcnory  Kits  >*<»<<«I  dua  •ilsnUoa.— i 


1 


It  l>  ■llh  mii'^h  F'l»<"'i'  ihitl  »'p  ("Drill  pdlilon 
of  lhk*inuEiiinocDi  Hf'fL  l>r#t«lid(l.  TliBuifhtn* 
•nd  pablblian  litis  mx'ii  Ci  f«l  proad  cj  lliln, 

Um  movt  i>oinpffl»>r(i"lT»,  rlthnnu  and  aorurBU  ,  , .  .        

work  or  (he  kind  <•*'  rniiu-l  tn  ini*  rniiatrr;     ll     fhavQiuchupirclBiiciiiDttliliKiMlonkHUnll 

I"-     tui  four  ■dlltina  wMhln  ifc*  foopi 


aft  llaaml  Im^ir.  Nnr.  1»T. 
V>  itilnk  U  ■  Bmilii  fm  Rmaraii 
rlahnrua  uid  uvuiaH  .  |irohMluinrDi»llfinr  idJ  ihalW  i4iuinMT>H>a 


>  itilnk  l(  ■  Bmilii  fm  Rmaraiitlallini  Udl  It* 


M  DO  w«DdBr  IMt  II  lit>  Ixoomo  ih*  (landuil  vi-  tui  four  ■dlltina  wMhln  ifc*  fooparMmlr  WW 

Iharlty  tot  holli  IJi*  in»dl(«]  ud  phannii'-BiiKr*)  n«r[ad  at  •lahi  r*u>.   Ths  mUitrT  «Uh  vlilr*  li 

pnlVHilfni,  ui-1  thai  ftnir  fdttinna  han  h>#n  r*-  d«*l*ar*  orV  immal  a  naiei*  iIiM  .tlik^riKi 

'    lo  ilifitlj  tite  MnrUAI  and    Ii>pr«a4^nc  I'TijrtlalaD  nor  Uia  IdiarmHlM  oaA  do  i>»lli<«l  Ito 

*     "  "  "  l« 


JnlrtJ    lo  aniitlr 
•ciiajid  ilDC*  li>  llnl  afiptvianca  lu  IfTu.    Tii« 
•nlira  fttiJ  liM  hrm  kp>u9  ut^i  and  Dia  laHfju* 
I  ■rlliitt  rrrl'ad  in  wvcrdaniw   w(lli   ll>*    lalml 
I  daTalDpmanl*  rciatilmi  iha  aitrlbutat  and  than- 
pauliual  acU-iii  of  •iiiifi.    Thcrcmnllraaf  r*««il 


pimMt 

Ilia  iiliarniHlM  oaA  do  kIIIki 
UlMI  lalt-bDolo  ue  ltirm.MM«tall]rtli-<>«lluil>n 
vuacfTbnto  a*d  mupcahapalv*  B*  IfrUofiau  n* 
l-onk  la  1nFt*4Ti>arn*dlMblabMh  uihaanllian 
and  loltietmuir 
Ma/»t. 


rilihan.-JCfw  IVl  Xa4ui*l,f< 


COHEN,  SOLOMOy  80LIS.  M.  »., 

A  Handbook  of  Applied  Therupouticii.  Bdng  m  Bia^r  of  rrincirtah 
A])pllc«bl«  ■ti'l  nn  RifH^Mitinn  of  MnltCHit.  KiuplnrM  In  iho  UMingCIuttit  of  lli«  fftd. 
Id  oDe  lOTSC  ISmu.  volumi^,  wilh  illiiitlntioD>,     Preparing. 

TABQUHARSOy,  ItOBERT,  M.  D.,  F.  B.  C.  P.,  LL.  Z>^ 

f^Hfitf  rv  uM  ,\frirma  XrAttn  At  Si.  X"-y'*  Ba*t*iiAl  MBAfAt  3fJntit^  £d444K 

A  Qulde  to  Therapeatics  and  Materia  Modloa.  N«ir  ((mitII))  AiMriow, 
tram  llic  (uiinL  Kngllxli  *-1iliaa.  KiilniKuI  iixl  aiht'lnl  lu  llir  V.  S.  FliAroMmfKela.  Bj 
PiuKK  WooiMiURy,  M.  !>-,  l'r(>r«aor  of  Materia  Mcdim  and  TberapMlic*  UM  lliunl 
UoUdue  In  ^i  Mpdla>-Cliknir)|i<al  Collq*  of  Pbiliuliilpliiik.    In  net  h»»«bmn>  ISma 


I 


Ilnu>(ennrilTt*i*||Ud*d>athanoa*  modaro 
work  CI  Ita  kind,  tl  u  mndw.  tm  compli'tp. 
OoikUI&Ing  an  aofAUnt  <tf  hU  ivfri^cTin  tt<ai  hava 
m  |d*n  lo  iha  llrlrlnh  Bfid  t'olird  Stnt—  I'iiarnii 
copafftB.aa  well  a!«ron*ldf<rtiiji  all  non^nkokal  bvl 
lni|M>rlAala*«drD|f*,U  brodniC' In  fAf^l  a  mlDlaliara 
dlap*Di*(tiiT^A>iyl<  Mtlifil  Jouiital,  Juaa.  lUt. 

An  ttp^wif  acfrVtlta  fv^tnra  U  an  arranfO 
nam  ))]r  irhlch  Ihrt-bralcl "■!''■  I  and  ihatapouiNal 


•rllnn*  et  rarlnn*  nifivdi**  ir*  alwwa  la  iwiM 
MluniD*.  Tnia  alda  «ra«tly  H  «H»  XHalla*  m1 
iKlUlalaa  atuilir.  Tte  AMaMcas  ailltoi  ha*  •» 
largad  Iha  waii  w  u  la  fnalia  II  l*<luita  all  lb* 
raiiHdlM  aod  |ii«Miratlan*  fa  Iha  V.  9.  ■'lunB» 
mfala  Tbe  bMk  ItaniMI  aaluahl* adillilna  M 
tha  lk>lariraMlHanQ(hto(no*llfniK«1wii  MtfvA 
—Amwtimm  I'rasNUsMT  ■«<  JTaa^  Sot.  •,  Um. 


EltES,  BOBERT  T.,  M,  J>.y 

JiilMfH  J-rufrjiir  ;f  CTiviral  liidlciM  is  ifnmrd  I'-lr(riifv,  JMImI  OtfrrlmfM. 

A  Toxt-Book  of  ThorapeuUo  wad  Malflria  Uedloa.    ImmlMt  Inrilw  , 
the  of  Slii'lriio  nn-i  Pmrliiion^r*.    OcMto;  M4  para.    Clolh,  98.60:  I«m1i«-.  $A.att. 
Tb«pr«a(»lonrk>'«intda*llni'dIi>lali*apronl-'a'>inni*Iid  Uia  book  aad  caaBWuial*  tlia  Mtbw 


acnt  tlacaaaamt-biiDkotithainibJMIiiir  ohlati 
n  iraata.  li  pDwaaaaa  all  (ha  naiwlnla  which  wa 
aiiact  la  a  twoV  t4  tu  kind,  anab  aa  niaaltaaata, 
olaiaan,  a  ^dlalon*  rlaivllldallen.  and  a  raA*aii- 
alilii  Jiiiii  ll  inaiiiliiii  All  lhf> nawMi drufa 
Ot  fromla*  an  uiawd  OL  Tha  vllolpal  indM  al 
Uia««d  VDI  b*  fanud  nrt  atttut.    Vit  hrarilljr 


on  liaTinc  ntMnvad  ao  aood  a  an*.—  if.  T.  Uttttt 
Aw-'-iL  Frh.  IK  IML 

t'r,  Edaa'  limk  rafirvMnta  b^'.ltc  Ihan  »UT  aUw 
book  tha  pneilMl  IbanpaniUw  nt  Ika  praaaai 
day.  ThabMklaaLhanuiAlrpraMint  oua.  Tba 
■■lawlOiMlnn  nf  raniadl**  na*  tabraooa  (a  l»*k 
ihanpniilqatlon.— nnnaacnIMat  Jlra.JaB.UA 


BBUCE,  J.  MITCHELL,  3L  D.,  P.  R.  C.  P.,  ■ 

fHviiManaad  J.aNur(rfn  JTiUcwi  jrnbM*>l  nirnpnlntM  lluirt^  »a«i  8—piltl,  l^id». 

KatorisKadiOBBndTherapeutlos.    .^n  IntrodiKiioa  toIUiUniiJ  TrauiiMnt. 
FmtUi  edition.  Unia,Ulpicei^  CUh,  11.50.    Stu  SlmJmliStntnf  Uuny^  fift  tU 

eMZPPITfl.  BOBEBT  EO  LE8FIELD,  Jf.  D. 

A  UDlVOrwl  Formulary,  conuiulnK IIm  Melluidt  ot  Vetparlag  uirf  AdMilal^ 
tfrincOffidtlBlukdcAkeT  VftirinfA.  "tVe  vWA«  tAa^uAvtV^i^Uaaa  aul  PtuutnaMM- 


In  oM  ocUto  Tduiaq  c! 


.  •  a\i  a*  WuATaSioKa     0«iu.VJ«>  ■,'w«i&«i  ,V.ifc. 


■eUiBEH,  llEXEAGE,  M.  !>., 

Practical  Pathology  and  Morbid  Histology.    In nao rcrr  liandaoioo ocUta 
volume  or  31 4  {i9Hi^.  wilhGiiillii<.ifmiIi>nk,iucMll7pliobP)Eraplilc     ClutbiV^TIS.    Jiutrtady. 
t»r.  ait^M^  ■I'ltMlahAl  r«t>uUil'>a  »•  ■  invtor  I  (ha   (natul   pAalMa    >»liu   (o  tM  labont'iTr 

Th*  Koltioi'i   OKlboila  at  ll*nl*ali>| 


.•■tlcl|«(*  ■  vDik  of  icr*a>  tvu*,  and  la  inli  ■« 
•ra  Ddl  illiapfmlnwd.  Tho  obifiMT*  ila»M<l  la 
ini*  Mlbjui  an  modati  if  camplatanai*^  pon- 
~* '  tn  (uon  a  in»na«r  m  U  nodM  iham  *>( 


■MkM.      Th«  aoibori   OKlboila  or  tukni*ali>a> 
•acUtn'ODIUnic  au-l  •talnlDR  at*  Nlnn  In  iltuli. 
■    ■"      fall    * 


■nd  ar*  ■eooniMiilad  ^ 


_,      -Juabia  fDrmutv  fur 

iltdint  Xmt,  Jmiy  t.  WM. 


m./iEyy,  nicROhAS,  m.d.,  Ph.D., 

^L^  Surgical  Bacteriology.    !f«w   (icoonil)  nlUlon.    In  on*  batubmia  ocUn' 
^HMBpagw,  "iili  i:i  lilHUv,  iif  niilck  IOiir«a>lor«d,snd  D  eo^nflng^  Cloili,93.  JuCrWy. 

>  „_.i ..  __.._........  .__j,^„j  ^111^  .  ji^i  |j„  1,1^  |((»ratBr»  ef  a  ■nlt]r«,  lh<i-  •••Ina 

y  trUliiic  aiiKh  I'mr.  W*  fardlalhr  aomnitDd  ihii  )onk  <" 
aJi  |ih7Mclaaii<la*Irauj4CliaM4Df  fa»  vli/^  mn*! 
«D  IwrHllatlODs — QonaiMli  ImiccMliMt,  Hn 
.11.  IMl. 


4 


A  Mty  ihoniiRh  and  ■il>i>u>i{n  t*Tl*«n(  tnr- 
TVbl  iHrrviin  (4  that  varir.t  bu-irrlnWy  trUlinc 
lo  tllnnrf'  flaoh  Mok-  »■  llili  an  nr  IDcaleula- 
Ma  bBBatl  W  Iha  ^aurat  iirullllunvr.  n>  thmy 
■Vtog  b««K»  bim  Id  aiunilaiutJaiidDiJiiilyiniia- 


I 


GREEN,  T,  nEKRTfM.  D., 

£«hrn  on  nil Aui>vv  t-*!  JfKTbid  ^naitoMf  at  aaiiive»«a  ■d«pUa(  Jfidtcal  fttaal,  £ondaa. 

Pathology  and  Uorbid  Anatomy.    Xn  (aixth)  American  from  iha  acTsnth 
r**Ueil_EngUili  cdiiinn.    Ocuvo,  nS9  nnv""!)  107  tAjtrant^  Clolb,  fS.T& 


I 
I 


Th*  PaUiclon  tnl  M>>r'><il  Anatnmv 
[*4lrva«  Iptao  nil  liauw=  hj  mfnibvr*  of  th*  in*ill- 
4Blt«a<>Ml<>Dtnii*r'l  anf  r<>mm'oiUili-ia.  Tli>n 
laaMivalT  an  UHalllnm  phjiialwi  iaymhnr  itlm 
ha*  sot  IM  irarti  to  hl>  ItWaiy,  br  II  1>  aimo-i  an 
Mmilal,  In  tv\  II 1*  kMMr  iMapu»l  in  thr  ni-nu 
of  iI»n*ra'stMilt1pii«nlhan>nT  wnrK  "fi  halt  lad 
«iiri  whii?6  «B  ara  a/'qoalDWd.  tiis  work*  of 
Oarmau  anilien  opos  palbulugi',  shlrii  hiia  ba>a 


iranKltlcI  IDU  English,  an  loo  atatruaa  for  tti* 
physician.  Dr.  Cr*«(t'a  vork  nrHla^lj  mafia  LU 
■IrtiM.  Tha  eau  ■xJilhli  ilia  anpranucv*  of 
|i*ilialq[1o*l  Mruelona  )u(t  aa  inrr  ara  aMa 
throush  Uia  mknaeopa,      Tha  ftfi  u»l  It  !• 


(•B>rKTi}r  smplojivd  ■-  a  taithriHc  ^  mid  iial  •lu 
'idrnca  thai  *#  kAt*  aot  ff 

UanauM  Ittdimt  ,VfiH,Onk 


dMiU  li  an 
murh  In  It*  hror, 
iimL 


'  bOt  ff^tk'Q  Ida 


PA  YNE,  JOSEPH  J-".,  M.  />.,  f.  iJ,  C.  P., 

^nii<7r  riHUi'inf  /'.tyiinnn  oiul  Litiff  ua  nihali-jtca!  Analonu.  SC.  Thomas  JIMpHiC  tmdkib 

A  Manual  or  Ooneral  Pathology.     I><~ii;nol  w  >ii  liitrt'ilm-il'm  lo  ihp  Pnc- 

tiM  of  Mi'4idi)r.     (U'lnVDtif  52 1  |>iigT\  Killi  1&2  illun.  nud  ii  mlorrct  pinlc.     Ckilli,  (3.6l). 
Krkn«jr]^,  b«  a  (la^hff  and  tiaminor.  th«  tiaol  '  Ml  fjfcri^r*  lb  (}>'■•*  dIVAua*  now  *l1h  reaanna^ta 

rvflalnl)'  aK'r|1i«4  10  pMllOlieDall?  nlPmbH.  lo 
1^14  ii0|partmriii  h«.haah«*ATKy  l^iMaadaaplK*!*, 
Dni  no  If  Id  a  datnlpHM  inaaoaT,  bal  In  llMMi'h- 
alqua  at  InieallRaUM.  Tha  iaoandll,  Bl*lna 
matiibti  at  t«MW«b,l*aloB«  wcirth  ina  ivM  of  IM 
book,  aaTara!  Ilfnaa  ovar,  to  aivrT  atudaoi  of 
pWhaiav^-JLIa«uW«taMlAirg.^r„Jts.'ML 


Bfr'Li  <if  miTill4.>aJ  hiuiivuL*,  Lh«  AfjLhur  Jia>  In  1h* 
W'lrl*  tifikrv  If  iiFeidFKd  for  ITiPlf  v>^'-k«l  il-i> 
vhat  wv  doEioi  rkpp]Ea^*  Cj^ -Ar  Sih«  ho4i  Inlrttduiv 
tt«D  lo  pHTaT  [.iilTiriloiEy  Ihal  wi  hava  r*l  '■' 
amiDfid.  A  dnjiAfiuFp  «f  hii-h  vat  airihor  lia* 
taken  U  Iha  i^rraLar  aliablton  |4Jd  U>  ih*  rwinfr 
UOD  Of  dlaaaaf.  aad  iBor*  aapaalallr  lo  Uia  vtlnlngi' 


COATS,  JOSEPH,  M.  />.,  r.  r.  p.  s., 

FaUolugui  lo  IM  Obusoit  WuIt^  JnXxiui'y. 

A  Treatia*  on  Pathology.    In  nno  nn  luiulanRw  ocuto  rolam*  of  839  puw, 
^Ui  S»  bMmlfoUlliulrMUiiWL    in.>Ili,S.l.iO;  l«al)i«r,  (6.00. 

M«U*al  (tudaota  aa  ir*ll  m*  phTxIciann.  who  i  manoat.  Iha  ehaniM  tram  ft  naimal  eoDdlUOB 
i»«lf«  aiaork  fnr  iludr  or  raffrfoca,  ihti  ir<«u  I  effaoiad  In  tiraeiunt  by  diaaaaa.  aad  polnia  oiil 
llta  aoUacla  In  tha  lutou*  daparlmani*  In  a  trry  '  (ha  rharvMrli-Uoa  of  ntrlana  morbid  anoela^ 
Iboroa^b  manoar.  hiir  "iiiiaui  ptviitHy^  wLI]  <>•?.  wi  ihai  th*r  t*a  ha  aoally  ratwfniaad-  BOK  oat 
lalnlT  |lfa  IM-  onr  il»  (■[•(•rin'v  u>  an^  <rlii>  Umli^il  i^  morhld  aiatuwf,  II  aiplalni  iHltf  hna 
which  «a  ar*  atqnaloMd.  II  a»u  (onb  iha  muat  Iha  funciMuaef  arcaaiaradlMnrkad  MaboDtaul 
NMDl  dMoTtrlw,  eiblblu,   In  aa   loMnilioK  :  eondliluoi— Oncinnan  J/atiml  .VHn,do(.  Un. 


tscnlFF.n,  EDWAJin  a.,  f.  r.  s. 


Tha  EBSentlala  of  Ulatology. 
91  illiuusLioiM.    Ctoib,  S2.2& 


In  ana  octaTO  toIium  of  Hi  |ias«k,  wlili 


XLBTK,  E.,  M.  D.,  P.  It,  5., 

Jnml  Uiwur  9%  Owol  JwK.  a>l  n««.  H  lA*  Mad.  AtM<  ^T  SL  5arfh>la>M>'(  0*ap 

Elemenia  of  Hlatologr.    Founb  «iUUan,    In  ca«  Itgao,  rulunc  o(  3T«  warn, 
with  IB1  illoi.    Ump  cloth,  »i!t5.     flto  A^MI/ 6Mn ^ JfMa^  pat(«  SI. 


I 

I 


vnnniiKAD^  rntcncAL  r«rnot,oor.    ai 
HftftBal  fur  8uid(«(4  m4  PrartlUonan.    la  «na 
hMMIlal  «aU«*  Tidania  of  W  paa*V  *■<■>  U* 


PRprni-s  SmtOIOAL  PATHOI.iMV.  la  oa« 
tat(ii»M«ia  IMM  Triooa  of  Ml  p^M,  vuh  (I 
llliMWMlMa.    LMpcioih,  radad||M,tt.«a    Sm 


1 


14 


LlA  BaOTHEKS  k  Co.'b  PcBLroATion 


ofMeft. 


iVi/.  >r  '**  JVihMpIh  an«  :Pr«K><t  cf  ITtA  oM  </ CMl  JVtA  xi  JIM.'<n<  JToipNitl  HadiMI  0>U«^  .<.  f, 

A  Tro«tiw  on  the  Prinol^dM  umI  Pra«Uoe  of  Medlolne.  Itatsanl  to 
tiw  uwof  HludMU  ami  Prailiti<'n*Tit  ol  MmIIHii*.  tint  ifiith)  p<lilii«i,  IbunnMhl;  !•■ 
vlaed  Mid  Kwrlunli;  iKp  Author,  ii»iit«l  hj  Vi'ri.u*M  II.  Wcij.ii.  M.  ]>..  Vrtimmed 
Pultolcigf,  JohiM  Ho|tkina  tlnirrmiv,  Balliiuorc.  und  ALvniti  Fuiwt,  Jk.,  U.IX,LI.  U, 
ProfMnrof  PI)]rsiolo|n,  BcIWvim'  U<»)-1uI  Mwlicsl  I>i1I«e«,  N.  Y.  Inona  vHjr I 
ocUvo  volume  of  UriopagBs  with  illuBlrntkiua.    Cloth,  ^SU;  t«iber,  90,60. 

Ko  Uittuok  oa  tk*  ^ndplH  utd  |>nHlo»  of  <  In   «l(jr,  Insn,  illlics. 
ma^lelii*  iiH  ■*•(  Oial  liiUili  rsUBlry  mlUi  Mi^     TUtit't   Ftm**/*.     IT* 


UOD*n  u  ilic  vork  «(  PrafMwr  Fllal,     In  all  Ih* 


fn*4lc*J  e',nrtff  uf  M«  VnllHl  8IM«  II  Ik  Ux  fit- 
nnIM  'ark  uuin  PnoUt*;  ukd,  an  n  ka»  fUtod 
b*t>t»  la  •IIU'IIDC  10  It,  lb*n  ■■  BO  oUin  in*4lfal 
wcffe  (hniMn  I*  »  MMnlljIniod  in  tha  lu»nr 
ita  af  phi*ki*i>ii  In  onri  ttt»t  aad  UrrlMnr 
of  IM*  •■«««>  turr  tha  iMk  Itel  vmin  »ai«  tikdy 
«ob*la>nil  lBUHolfir*«(a»*ifkMBi«kirhMh«r 


or  •*  •om*  mrmt  tnnii.* 
nuk*  UtU  iiMfiMi  m  * 
MrBtiitonit4*  •  ■  laal  ftw  rarwwal  nkaviMMuM 
it  b  ihB  tMUnomy  •■•»  nr  oUian.  Ab  i^lib 
UiMi  iit»m  Uu(  *i>>7  OMiMilBnWa  ihakfii  tan 
bMD ni«di>UiUi»«liilt •dlUnn.  Tli* VMk MV<>^ 
dovModl*  bv  f«|tBnl»4  H  fklilv  r*|>raHrBU^  Ite 
prH«nl*lal*  aflb*  kIodm  uT  ■•hIiMm.mI  m 
ri»mlag  (ha  iWw*  ol  uma  Kho  Miwpllty  w 
■halj  ioMIm  Uw  prwinl  nuaa  at  wMi— «(  Ka4' 
ttnl  wt.-.«H*iMM  jr**ml  J? MM,  bfC  UN. 


BRI8TOWE,  JOHN  SYKIi,  M.  /).,  Z-i.  J>.,  JT.  It,  ft., 

gmur  Pl^niuiii  la  and  titlvtr  m  Xe'<i--\t  ir  SI.  rx*wH' Uuf^lo^  lonJiM. 

A  TtmUm  on  the  Bolonoe  and  PraoUoo  of  Uedloine.     Seventh  ed»- 
lion.    ln«M]ugaiicUfOToludMariaae|Mgc&    Ckith,$e.SO;h*tbM-,$TJQ.    J^rmlt, 

■nnrxTirkiMtnnlwtlir  wllhwhlah  M«a4l- 
tlant  "f  i-'>1i  n»k*  Uotr  ipponinM  l> 

Milkln  .   la  11*  •intlUdo*  and   •■l<i«. 

TMi,  1'  rif  tho  Diinwran*  rli)*  for  ih" 

b<r«r  i>(  UiD  ■Luilsut  nUck  hu*  hMO  pal  KirlK 
■tMln  ll>B  tltWnn  VMM  ilDM  BrWoiN^*'H*dl' 


tfiie"  nr>t  iipi>nr*4.    Kor  cu  II  t>*  MI4  U>M  u» 
■aUtst  lilBiH-U   hH   IWII*d 


10  kt«p  M< 
■>>iMl  of  wltnnclait  know'nlK  udaoui  la  Ikal 
laik  muM  rniT*,  Ho  )nn|  tn  iharo  I*  *ha«n  MMh 
•nra  t»t  *LrviiNHpa«Uott  (n  t)i*  tnctOKinn  ot  all 
navBatlar  IhMlHwiacAd  ll)"  iwi  nf  prliMiai,  •» 
tama  wtll  Ml*  iMrtI  i*lala  Ilia  taior  trhloh  It  hat 
■hiat*  mat  Pnr  il  l»  ■  wart  ilkal  la  Inlltcvft 
MabTa  IbuaOuiun,  •v>|M^all^  •etttltf  and  pnc- 
Meal,  oaMxInlnc  lh«   malcrad  ««p»H>»t<  of   k 


iihytlilBa  dho  haa  Fvwr  eWm  lotwi   

an  lAlbDrti;,  and  KipnaaJ  la  ani^la  vhaui  » 
imPU  111*  [Viir<lilimartaiMH<hakihaMiliMii.  k« 
Mia  ms  «;  iliai  iMabeok  t>u  <.t<i*irL..i  iM-aaia 
whklimaandsai>t»d,*»d  •■  iiaaaAif 

■III  lone  wMlana  i"  auf  >■  mrtmnf 

tn»b  tillUa**  lor  Uia  ailt»:  '  *  aBnina 

faaaiallaa  vt  tnadlnd  alUdaDUs.—  TM  AtaiW,jrf 

TsLuM 

Dr.  BrttU"*'-  "jw  riin'fli  if^itiu.  af^Mn  M 
III  Hraniii  '  iHaiia^ 

In  irhtah    i  '  in  t*- 

mandalkn    -  .  i  id  Bvir 

•a  XBiiafc  Wie  iihiI  <><>iiii.<in  iiu.t  >.»r'ilrfinb 
tacikiL-9i«M  JtMMat  Jbiiniat,Sa»<Mntw  R.  ■« 


OAMTSHORIfK,  It  EN  BY,  M.  !>.»  Z£.  />., 

tttlttf  pratrntar  tf.Hva"^  >*  t^  C«*Mraii»  »f  ftaiqli  aiiii, 

BaMoHalt  of  the  Principles  and  Praotloe  of  Modioine.  A  RmAo* 
for  HtiMaiM  anJ  PnclitioBan.  Fillh  »litit<n,  DiorcaiKhlj  r«TlM>l  NmI  t«writt(n.  In  <•• 
n>r>l  I'teo.  vo)llID«<>r««»t««:«^«lth  HlilliMinitkiM.    aMb,nLTA;  hi>inKaiD<l,|lJli 


niinin  Uw  oranpaM  •<  aM  MC*«  tl  IraMa  «(Uu 

y  af  andWlBt,  »ovnl  l«il 

iunaiAlo|[y,and|>riir* 

wiOO|>rt,  o|4ilJiartno*> 
aamiiM^Knaoloir.aadaMCWratiwiapjtni 
ifw.    rhara  ■•  a irnadmni  amonat  <draninnailoa 


EmHunaiAlo|[y,andpliir«te*l  dlacnealannaBdlaw 
7afeaooi«,  oiitilliarnwec^,  atc\gananl  IkM^ 


•«ralala<dln  Ihla  mvk.aM  M  b  on*  D(  lb*  bail 
t4  Na  kted  UiM  *e  lian  Maa^Qlam*  J(a«M 
JbvM'.  Nil.  iiM. 

An  liull>|»>n«Uilat>iflk>     Ko*ork**«r*iMhM*d 
a  bpllar  aiTnii^r  of  a<t<iaj  praoUaa)  Inalmeni  Ikaa 


ihia  aaa:  *»d  prukaWy  noi  on*  srlio  la  air  4* 
hail  a  hollar  <Mp«t1llli«r  Ihu  IH.  Ha  ' 
«andsn*liM  •"  'Ha  ilava  of  »'i .  r.  ■. ..  <  . 
Intaa  inti'i.    7h*  nutnoMU- 

ran  Oaaflll  In  •(odoBl*  *f 
UaU,  •■  l>i*  Baa»«  Bvinab,  i 
■opanxls  lb*  Mil-l>«nk>of  niM  mm 
tM  ilioy  *f«  Iba  iDivl  raluaMa  la 
innuii  Ki  a*«  Ma  alaikr*  Uia  atHila  IllantiiL . 
JI«*H>.an-llhaa***i<*laiMainalMH>BL— I 
3la4int  .fMrwtoad  giaii^r.  April.  IHL 


MMrtMW 
■nliii^lll 

wbl    Clip 


BETNOLDS,  J.  BUSSELL,  M,  D., 

iVa/iaHri^IM  AvinplHiMd^-arlmaf  IMiriMik  tl*MmM<t  OB«f«,  t'iiiAi> 

A  System  of  Uedlolne.  With  nut^t  and  a>Ulilocu  hj  IIkxht  HAsranonA 
A.  M.,  M.  b.,liite  Crofnaoro^HnictieiiiUM  UnivarMtr  uf  PeDn^lvuiK.  In  lliiv*  Hi* 
«acl  hMiibeimc ocUvo  voliunei^  ocauiidtig  90H (loobl»«nliimMd  p«niL  wlUi  Xti  Uhaui- 
UoiuL  Price  par  Tatunw.  clotli,  19.00;  sliMU,  VAXM):  nn  hMiibolM  halT  KlMalJ^  niiol  huA^ 
«e.M.     Per  M,  cMli,  |1A.00;  leather.  fl9.oa     AU  »>^  ty  nioripMn. 


STILhiC,  ALFRED,  M,  -».,  XX»  D., 

rv,/ubi'  JSH»ii<ur>f  Ihi  n»ryand  rVwiiAai;'  Jrnl.<i.Wfl<  Ci-aetl  MM.  It  I**  tfutr.  1^ 
Choiora:    lunrtgin,  H(Mur]r,(^aiuatiim,B7iU|itiMU,LedMi^  Pwi-entiuo  and  Tran 
nent.  In  ono  hanlaniiie  12niD,  volune  of  163  |Mga^wtth«dlMt.  CloUi.fl.SSi. 

WATSOX,  SIB  THOMA8*  M.  Z>., 

ia(*  i^paiNaa  In  OiMtaty  lo  llw  Qutm. 

Xeoturaa  on  the  Friaoiplea  and  Fraotioe  of  Phnio.  A  tmm  AiMriM 
fnia  lli«  fifth  EiikVmVi  «Auiw.  ¥Aiur&,'«\.vi&«>Uii.i<Hw,  a».l  IW  illiainukiMt  hj  Hsnt 
H*Kn.iioR!«it,  A.M„M.tl.,\iW  VTOh#«»«<*^l»amt\ft  WcV:^'(>\iTnh<.'iQCI%taqrlnaifc 


rSsornns  k  Oo.'»  I'vauoAi 


Flar  aah  bg  8%^»eripiioH  Onty. 


B    A  System  of  Practical  Medicine. 

^B  BY  A UERtCA N  A  UTUORS. 

H  Edited  BY  WILLIAM   PEPPER,  M.  D.,  LL.D., 

^V   piioTo«r  Airn 


piiOTo«r  Airn  rHoniRMR  or  thx  msORY  amd  rRAcnci  or  mhiicivz  axd  or 
c>.rHicAi.  MUiiraiiB  IK  THB  osiivKiuuTv  or  rB»nTt.vA)iiA, 


A«lueil  bj  Loots  tta ASS,  M.  P.,  Clinical  rnr«nr  of  the  DImmm  of  Cblldiw  ill  tbt 
HMjiiul  uf  lb*  UnivsnUf  of  PtiumjlnalM, 

Tht  eamfUK  mrk,  in  /at  columa.  emiaininy  5673  pnyE^  vilk  19S  iV^MtrnttMU,  ii  mw  m^y. 
I         Mm  ;Mr  rolumt,  dolA,  9^^;  Uaiittr,  $6 ;  Ao^  Kama,  rattd  bamlt  and  span  iod,  97. 


In  ll.is  erenl  work  Aincrian  tneiliciiw  n  fur  (ha  fim  time  r«ll«ct«d  hj  iU  worthiMt 
tencbcrt,  Diul  prnvnlcil  in  the  Cull  ilcvalopmmt  of  Um  ptmOieal  tuilil*  which  b  ila  pn- 
feiKirut  cIiniMcifirittici.  Tliu  lucntl  aiil«  iiitn — fruin  IM  BmI  mwI  us  WmI,  tttm  tba 
Koith  ■nil  the  Suiitli.  rriim  &U  the  iironiinMit  cvoln*  of  cduCBliotv  aiul  fann  all  tho 
hMfiiUJa  wliich  nflbra  ipecud  opponunilia  for  aludr  sikI  prvotioe— hare  mtilal  to 
fMWKU*  riralrj  in  bring  Mc«th«r  lliM  Tut  wgranM  of  •MCdMuod  «xi«rin]c«t. 

Tbi  dUiiiipiioiiMl  vdllor  hu  ao  ^ipoitunMo  th«  ynuk  that  lo  mcIi  nutlinr  hn*  bMs 
■aiODcd  Ui«  Bulyeci  wlijcb  he  ia  jKHTnlinrl;  6tl«I  to  ducUM^  >iiil  in  wbkh  hit  tiem 
wUrtw  >ccc|ilod  u  the  lattst  rijirtwiun  of  KicntiUc  and  pnctioal  kDOwlcdtc-  The 
practltioaar  will  lli«i«fur«  Gad  tlioic  vulniuai  ■  nim|>let«,  mllioritUl**  and  un&lTlng  woi)c 
of  nftnnee,  lowlildi  li*  nii;  at  all  timea  bini  with  full  L'^ntiiitr  of  tadliK  what  be  neali 
!■  Its  BKat  rcocnt  aitieet,  whethsr  ha  aaoka  Inronuniion  on  the  gmenl  pnodplMor  uadl- 
cln«,  or  uiiniil«  jtiilflnnra  in  ih*  irMtment  of  «ii«dal  dbawM.  Bo  wid«  U  lli«  kii\»  t>(  tho 
work  thai,  villi  the  vxcvplian  uf  uxuiv'dtij  aod  maUfin  aUicllr  kuigical,  it  uubrMW  the 
wbotaikiniLiinnf  nivdirin',  indwling  lliadapartnicnia  (or  which  (h*  pli/aiciaii  b  aooulnnicd 
lo  rtljr  uB  q>MJ>l  trNiiii>««s  (ucli  ai  diiewaa  Ol  womfs  asd  chlldi«n,  of  tba  gaiilta-iitlnary 
ocnua^of  ihvakitifOf  ihenerrM^hyginw  and  MiubuT  acienca^  and  awtical  ophihAliiwlop 
■M  Mologj.  Moreover,  wlhora  nava  itunUd  Ui«  rantuilaa  which  tha;  haro  (aattA  man 
«fid«nt  in  th«  trwtmMit  of  il>«  nrlotu  aAMlona.  It  mar  Ikua  be  iral;  rcganM  a*  a 
CoarLXTx  LtSKABY  or  Pkaohoal  MxDinxE,  and  the  general  [inililiniiiii  |iiiMiMliijt  It 
■Bj  fael  aacaro  that  ba  wUI  r«|«iira  liltla  aim  in  Iho  daily  touad  of  tuofaaioDal  dullaa. 

Id  apila  of  CTerj  aSbrt  lo  eondMioe  thv  rtutt  amount  of  |iractical  informittan  Utr- 
niabod,  il  liaa  Wn  iropoNible  lo  pnaeot  it  io  lea  thnn  6  JArga  ocU*o  vulunia^  anUaiaing 
aboal  WOO  btautiAilty  printad  yugat,  and  rmbodTUig  Iba  mailer  of  about  16  ofdiaaiy 
octtToa.    Iltustraiiona  ara  lalraltiotil  wh«n9T«v  re(|tiMil«  to  alucliUla  tlia  taxi. 

A  dOaiird  proipfelmi  nil  be  tent  lo  any   adJrat  an  appliealiim  to  iht  paUitktn. 

phjvliitaDi  nliu  If*  acaualaMvl  lalili  all  Uw  Twta- 
IIh  ot  ollmaui  tn  (ha  Dntwd  Su<*^  ib«  cliararMa 
at  ta*  iMI,  tb«  maanvni  and  auMom*  ot  in*  1*0- 
fla,  fto,  11  11  iieculIailT  «ilayl*<l  to  Uic  waala 
or  AnMrteas  i^rsctlUoowa  ot  mfillolB*.  and  It 
jaavf  la  ua  Ihai  «f«f)r  odd  uf  ihdni  (tuuM  d**tra 
l*h«Ta  IL  ll  tia*  li»n  uulr  rallc'l  ■  •■  fntttft*!* 
Lnmrr  at  ITapUoal  Hedlolna*  aa-l  Ilia  (iiaaral 
■neUUODar  vtll  mioir*  lliUe  alfa  U  kl*  rouad 

fiarrh.UH. 

Barh  of  ih«  tnlumM  U  pmfdHl  «tth  a  Beat 
ooplflui  lBd*i.  ud  laa  w«rk  alutathv r  f««ml(M 
lo  twoaa  ■hmti  WW  add  moeb  lo  Ui*  madldal 
Innrauin  at  tha  praoMl  oaalurr,  and  nSoO  g»M 
mdll  BpoD  Uia  Mholanlilp  and  t>rv(lnal  arunaa 
ofll*  aulaofa.— nf  {«J«  taaM,  0<4. 1,  tnt. 

Til* lHlle«Dr proud  aalbbMloo  iriiii wbieb tha 
Amarlrui  pntBHlOB  taaa  UiM,  Ila  twatanMUTa 
■rtUm  «f  pr*ftU«*l  mailliilBe  liauad  io  Iha  Medi- 
cal awl^b  ItiM  JuallDMl  tir  Ui*  rkuatw  ot  Uia 
wak.  TTie  aollra  cwl«  ot  Ih*  ajPMMk  I*  In  kaap- 
laa  with  lb*  bMt  ihonalMa  at  itaa  leatora  and  M- 
lowan  o(  our  bona  aohoed  ot  marta*.  and  Uif 
eeiMnaUoa  «d  ifca  aolwiHa  awdr  oTi 


Thai*  IwA  tolunixB  brlUR  Hi!*  admlraLlo  wAfk 
M  a  Pin*,  and  (iiJIy  aiuiun  ilio  IiIkIi  nUindard 
tvMlwd  Of  Iha  aarUM  toloinri:  m  l»<o  oaly 
tharctora  f«  ociia  the  anlc^um  f^roDoubcaJ  ui<iu 
Iban.  W*  would  ■■rmly  TuDnrMuIaM  Uiaadllor 
aad  hia  obllaibomjDrv  *i  \>i,p  mnaluBloD  ot  (hair 
lalMinon*  latk  on  iha  a'tmiimMn  mannarln  wbloh, 
(tMa  kmlo  la*l,lh*]r  liai*  iwrformed  Itialr  (aTonl 
AoUaa.  Th«y  h»*a  (uawadeit  In  urDdueloc  a 
wark  wliloh  Mil]  Iook  ramala  a  ttwidatd  work  of 
lattraoe*,  to  ■hioh  pntoillloaan  alU  lot^  tot 
MdnM,  aad  auihof*  will  laaan  Itar  Iwiu. 
rroM  a  tUaniT  polot  «4  Tlaa,  tha  WW*  I*  alUioat 
an*  MriMU  bmnlah,  aad  In  nw|>aM  ot  produMlan, 
llhMlWhMuUfUl  flnlab  ihu  Ani«ni«B>  *!■■>> 
■Ita  Uialr  aorka^— JWIiln'g^  Jtciiral  JnrwW,  Jan. 


fi?.' 


•  •  Tha  ttmusi  dliUnetlToly  Amorleu  work  on 
Iha  prw-im  rr|  mnltoln*,  tni,  la<laad,  Iha  aopar- 
IhItv  ndji-oilx  vnuld  Dot  ba  Inai-pniprlala  Kara 
avaa  all  iithar  |>ro4iiPlloDa  phKad  la  cunipUtHm. 
aa  aiamliiail'io  ut  lli*  Ata  Tolnina*  >•  ■uflloleol 
to  aoBtlucB  uod  of  Ui*  nunltu4a  of  Itio  anta^ 
pUri  aod  ot  Ui*  (iiixvaa  wEliih  ha*  auaaAid  Ila 
Iniainianl.— TW  Jtidwal  ^t",  Julf  31,  UK 

ThlB  huaa  nilafna  formi  a  Aulnsolo**  lo  the 


MMiraUm  ot  madlolD*  whtah  In  aa  ■borl  a  Dma 
baiKinao  hlabaplatalo  madloal  UUtataia,  and 
hta  4«B*  aaen  nadll  u>  the  nntaailaD  la  ihli 


aountir.  AnionR  tha  laantv-lhre*  eaniithulon 
at*  Iha  nani»  ot  Iha  laadlaa  oaureloglM  la 
itmarloa,  and  mcHlof  ihavotk  fn  ih*  rolama  li  af 
Iha  blghi-t  ordar.— JlHloa  JUadHnt  and  JIHMal 

Axoin',  Juir  11,  lan, 

Va  oAoaldat  II  osa  of  Iha  craadail  worka  ta 
Pnciteal  Madlolo*  In  Iha  KngOah  laacuaaa.  til* 
a  aark  cf  ahira  tha  proJ>Hlon  of  IMacooiltrT  can 
Mat  prnuA     W/fMaa   alcfivltalj  bf  Aa»rMan 


lb*  praMleal  •ppllMaloa  0(  aaaM  and  oaparlaMa- 
U)  kooDladKa  h>  Iha  Ifaalnaoi  of  banao   mat- 


a.li<u.  R.akai  ovary  on*  of  na  shata  [a  tha  prtde 
itiai  ^a•  aalooiBOd  Pr.  raaaor'a  lahoia.     Bhiatid 
ct  Iha  protutir  thai  waaitoa  Ih*  raadaaa  of  iha 
llannaa  aahoaL  IM  anMaa  alaaa  <mb*  < 
aaldafcr*lllhill*Tataafal».     Ill 
of  aroaalBaa  brain',  anil  la 


_    ._.      aain* 
la  tha  ouitonia 

_,  .  .  oualiod  l&nashoul 

Mr  oiueb  *4  Of  alurdr  Indaaaadane*  ot  Uiouahl 
and  orlalnaUIr  thai  l>  a  nallaaal  tkaraalarMla. 
Y*«  aovhara la  lb«r*  laefe  ot  MUd*  af  Iha  raoM 
■dtanoadrtmafthadat.-Xo'W.OvoUMHiA. 


10 


hMA  Bnornsas  A  Co.*s  PcBLRunom— CttnicKl  M«d.,«ta. 


VOTHERCILL,  J.  M.,  M.  D.,  Edltt.,  If-  R.  C.  !>.,  Xond., 

The  Pr«ctitioner's  Handbook  of  TreatmQnt;  Or,  Tbt  IVindpIo  orTh«r»> 
peuUci.    Xtr<r|llilnl)tilitiofi.    Id  mic  t^to.  vi>l.  of  (141  ]iiib«il   CUiUi,  {.S-TA^  lcaUi«r,Kl)L 

m*  it  k  iwj.flul  tMtli.  ir  IDMvbatBM* 
thl>>(  ••  "m*dIalB*  oiadii  'ur,"  ihia  u  Uw  •«%  W 
MclcwpltabthtorMiin.— I'a.  Na<.  Jhaia,  JnM.'K. 

■n(t>tnui|tM*M(Mfly  ■iiirmml.  uhAiImUh 
MuiUdI  iM  *««Da  ifnvililbuar.  |i»>lui^  ana  it 


T*  b»t*  •  4«Mrlf4lon  of  Ihs  nonnil  plinMttsl- 
«>l  pTtefM  of  wi  oritB  ut4  i^  ilr*  maihedii  of 
IrMUnaDl  of  U*  morbl-l  fan>IIL*<M  hnii|lit 
liwMliar  la  ■  idnitl*  etttittt,  ao<l  ih*  nniUM 
b*i*MiiihBliMvl«(tyMM>4,nt<>aiHnil1  M|ire>a 
■  iiaii  •■>a**DMnM  to  n>M>  UHwhtAil  bui  bHy 
pCyilclaoi.  ThalirKiWal  nJsaof  Uia  (nluBWb 
Bml^  IncMuad  hj  ilia  latnJuttMi  or  maaf 
prMVriHIon*-  TXU  in*  proftoloa  a|4«*cla)a* 
Ihat  lh«  aalkiT  ku  ■DH*rUk*ii  aa  Importanl  watfc 

Bjil  hM  ueonMHhHl  U  ■•  ihoon  iw  iho  diioiand 
r IbU IhM adlUM^ ff.  r.  Mtri. /Mr, Jane  1  l,-n. 


. _- ,-- "•'.  ■■aihaa*  i     _  .. 

W*  do  nul  tno*  a  niura  raMahl*^  fiteltimi  «M 
iiHflil  wutk  (•  ika  ifBaimvDi  of  diiaaan  UMa  ilw 
on*  «•  han  an*  b(4lu*  iit.— /^KtM  JMuaJ  .M 
Airpiial  JlHmitf .  0«utor,  Itsl. 


VAXJGUAy,  VICTOR  C.,Ph,JK  M.D., 

and  XOn\  FREDEHICK  G..  M.  D. 

Ftomalnes  and  ZiOucomataeB,  or  Putre&otlve  and  Phyaioloctcal 
Alkllloids.  Kcsnliiioa.  In  ono  bindwaia  l^nu.  voJunwoflOOiiagM.  Ckith,R.3S. 
Andy  tAow/jt.  

FINLA  YSOX,  JAJIES,  AT.  th,  EdUor, 

/*«)■•«>"  a-^  f.wfiir*'  M  dwHUiil  JMlniM  ia  (M  CthUftw  n'«<(rn  Stflrmmrt,  lU. 

'  Clinical  Hauuol  for  the  Stady  of  Hedioal  Casob.  Witli  Cha{4ta 
bT  Prot  tiftinlner  on  lll«  nijviogiwiiiijr  of  UfaWP;  VraS.  Slcptictiaoii  on  IMmmh  itf 
tha  FcoiBla  Otigui*;  Dr.  Rnbartcoci  on  InMmltjr;  Dr.  Ucniaelf  oo  Phralcal  UafaMb; 
Dr.  CmU  oa  LtfrnfMcci^  md  Pua(-UonMn  Eiuumitkouv  and  b*  tha  Editor  OH  Cm*' 
uUdg,  Fuullj  WMrj  tiA  Qtm^/Unatot  DiaorJer  in  iha  Varjoua  SfManw.  N««  editiciK 
In  oiw  ISma.  vdume  ef  682  paffcs  «3tfa  I&3  illmtnUioa*.    Cloth,  9150. 


Tba  infiHatbb  tannol  t-nt  nlMioia  IAaMO»a4 
•dUlan  ef  iliJo  nrf  laluaU*  work  o(  Plnla^MW 

Kl  Mr  oatUbaraton.  Tha  *l*a  vt  Iha  bnnh  Iih 
M  IncwH*  BOil  (ha  nuBhit  of  IliuiinUmi 
Marly dooblad.  ThaiDaDaarla«liichlIia*ub}*ci 
U  Uaalad  !■  a  fn<M  pnciictl  cna.  SymfiKaai 
alona  and  ihatr  fHanoailo  iDdintiUm*  r»rin  tfia 
baaliot  dItOBUWn.  Th«lailait<l*iD«rlMtl]paad 
fDllT  <Im  n><lh«li  of  aianlnaUou  aad  tha  Brno- 
clo«l<M  M  ba  drara  ftarn  Uw  pbj afcal  ttKaa.— 
n*  Xaftcnl  XOHL  April  ti.  Mm. 

Wa  ai*  filaaaad  la  t»*  aaacood  adMloo  or  llita 
adnlnMa  M«k.    II  ■■  aaaantbuly  a  pravUwl 


InMUaoa  awdtal  dlwaaaU,  In  vMAannttii 
ud  tfaMMB  o(  dlMsiI  U  «wMI>  BkUnad,  Ml 
Uialr  t»1all««  alcntlWuM  la  Um  diawaM  tfa^ 
tlDuilavbleiiUM'raoawpotatadaM.  PMniMr 
■jrMhaala  IM  ainJtM  oM  aoMmMv  dMMWM 
iriadlHHMirltlKabifbtiabaatodaaK  TWbat 
haa  ba  eoBiiniHnr,  nni  In  It  Itkaly  hi  ban  la  Mai 
H  hMura  aalUaBt  oialnuin  ita  fqasaal  itaiidild  m 
ataailaacia.  Tka  (aoaral  piaetUtonar  vUl  iM 
■Mny  pracdeal  bIMa  la  U>  r*cH.  vbna  a  Mnkl 
Mudvaf  ibamik  laUl  ht*  bin  (rooi  nuay  ••■■ 
la  dlacnoaU^taMrvaal  Maiim-CttntmUti  JM^ 
M^  JauoatT,  UK. 


BROAl>BEirT,  W.  H.,  Jf.  D.,  F.  R.  C.  P., 

nyilnan  la  aad  Utiynr  »  ATaAr Im  nt  SI.  JVarp'i  fftaiHMf,  ivadm, 

Th«  PulM.    In  cm*  I&dq.  toIuum  Di  812  jafM.    Clotli,  11.73. 
teal  JfdmKiti^  |Mg«8I. 
Tbia  Ititia  baob  pn>««bly  repraaiBU  Ibe  b«a( 

Celkal  UiaBRht  au  ltil>  uitil*cl  lu  Iba  Eailiab 
I  '"■ 


SttSmimafam- 


aiuiai.  A  wRMt  InUrpraiallan  <i((ha  tida*L 
ttllli  lia  altnoat  InKnila  niadin«Mlni]ii.  tirciisbl 
aMHit  by  tiotwl  uaHmlWil  bodily  Ta(taik>B>.  tan 


oolyW  adilarad  by*>parlaa«a,  ai>4, 
Uwatd  »uai>iia<Uil*B«alL  •ouilni  <■ 
•anloa  Umb  l£lt  broMtuN  nn  Iha 


puiah— n<  J 
Haptamhai.  UM. 


■■?«,  ^    ■■  wm 

•UlilniKlIf  haaTiM** 

aluM  aTttl 

laliM*^ 


BABEUSBOX,  8.  O-t  M.  J>., 

a—or  fli>am—  «»  aad  tola  ft.  —  Mtfrim  <■<  f»««lfc«  «f  Ifad.  1  e^«  BfpUat,  Im^-k 

On  tho  Diaesfles  of  the  Abdomen;  CtonpTiabiK  tbote  i^f  ib«  Stonudi,  mi 
oUirrMrtiioribeAluuentar7C(aAl,ai>0]ibwM,0KoaB,lDl«aU(ie*UHireritoa«unL  !)KMd 
Ani**leaD  fmn  tbtnl  cnlamd  And  rcvlaM  Eu4U>  wlitMD.  In  cna  hAodsoaw  ocMR 
Toliim«orftMFac«i,iTilhllliuinlIoD«.    C]otb,CLSO. 

Tbia  TllMMa  IrcatlH  nn  •llHwei  of  Iba  alonacb 
a*d  aUiMDaB  Will  ba  li>ua-l  a  i-yclopiailU  tit  Infar- 
WaWn. ayilamlleaWy  ajiaiiga-J. <ni  ulliliHamar 
Iba  alunaMair  InM,  frum  ifta  maolb  U  Uia 
iwwm.  A  t*ii  pNforitM  <4  aneh  thaplar  it 
4atal*d(oay(n>iau»,paibote«y,a«i4lhen|>tuU<». 
Tba  i<nnn[  *dlil«a  la  filler  Uiaa  liirinar  onaa  U 


!•  Iha  limat,  ■Dd  nabl»i  II  ■  minns  at  inlaraN  tl 
ry  a*M  t4  madMiaa  Ml 
Alt 


U>*  prw^li'    '   r 

•iircarTi 
aiasFlaiHl 


■imutt, 


U  In 

ha*a  ^ 


aiMiy  panlcuIaM.aBdbuhaanlbacDiic^ 
Ud  amaadad  by  Iba  aititiof,     tlatrii. 
(ara  ba«a  bara  addad.  biinRinf  iha  *  < 


laad  ' 
Af«i,un. 


<uf    l.-t-.K-h  —  -V.     i,     ijffit.. 


TAXXER,  TTIO^fJS  UAHKKH,  ^t.  J). 

AHanualof  CUmcutlUcdicmo  und  PbjBicnl  Diagnosis.  Third  AsMriau 
train  Iha  Mocaid  Luadra  Mlitiua.  Rvrianl  .irnl  fnlartMl  ^j  Tii.xtiKr  Fox,  M.  IX 
I[iuiMMMlllSiiw.TOlunMa(S62pgttt,<'i>^  ilJiii(tnili->ni.     Clodi,  ll.Sa 


LIUnrREfl  O.*)  THR  STVDT  OP  PKVKR.    By  r  LA  Ii 
A.  KcMH,  M.  IX.  M.  R.  I.  A.    !■  on*  Ocuio       .^      : 

nituma  of  9*  tap*-  c««ti,iuo.  I    _„„ 

A  TREATISE  OSrtVSK   *j  &»««.  O.  \.W\  Tlw™» 


.  RLI.OW  rCVBR,  «iau.<af»4li 
. ,  I'Mbatac*"*'.  Blli'^'Ct'a]  aat 
^BaWlMi.  laiwel.  t- 


ftuOM^P^-Rr^eiie,  Electr.,  Piact. 


BAMTHOLOW,  ROBERTS,  A.  JU.,  M.  />.,  LL,  £>., 

/V>f.  0/ JMana  JfaAca  and  Ovwrol  TXnpnina  w  M>  >(ri>^>tn  ifai.  CbIL  1/ miK, 


H»dioBl  BleotrlcitT.  A  Practkal  Ti 
10  MoliiriiM  nod  Hunctj.  N~*w  (thlnl)  tdilloa. 
SOS  pWM,  Willi  110  illiiBiniiDiu.    C'loili,  tlfiO. 


on  tho  Ai>plicaticqi»  of  EUvuldt; 
In  CMM  nrj  bmdMHue  ocuvo  rolune  of 


TiM  kM  Ibti  ihl*  <N>rk  hH  muilieil  <i<  iMnI  xll 
tlOd  ID  •li  r**"!  hikI  UiM  tl  liv  b«a  kcut  hillr 
mtn«M  aUh  ih>  incrvMing  uM  ud  kduwInditB  a( 
•l*MrVtiy.di><niir»lnM«  iHolklm  Mb*  ntntldoiwl 
•  HWtlMl  inAilH  «f  ttla4  Mill V  l«  111*  pnifewloo. 
To*  mUMT  •dil*d  talbe  iimcntttUllMicnibMCH 


UiB  mtitl  r*o*Dihl*h^o«t  lu  c4*ulrL4?h]  infttnttmi, 
Tha  iUuitniloni  w*  ■liim-Uul  *a-l  fivar.  uxl  ilia 
■«k  oaniilliilu  ktull.  a1a*r  ui-1  courut  inaniuil 
■•ll  ailiiiiiMl  to  Ui*  DHiU  <4  bnlh  t«ailvD«  uhl 
pnmuloomt^Thi  JVafMsl  A«n,  Mar  II,  IMT. 


Y£0.  I.  BVBSEY,  M.  D.,  F,  R.  C  P., 

Frtfutcr  if  Otnttal  Tlk'n^aM)  I"  A'»i/i  OWi>)PS  ^wlen,  ai^d  /^yaMwi  M  JITof't  Qh'^tm 
ffowilal, 

Food  in  Health  kod  Diseaav-    In  on*  ISma  mlunia  of  AM  pag**.   CLmli,  13. 

Ste  ^r>M  0/  (.Ii'niiiuf  Maxtiai*,  page  31. 


LtTfo  •nriillr*  In  ii-;>>mpiw<lanns*wl)rklllhM 
Uis  (.rvililonvrnquliMio  knavou  ih*  hii)*cI  i-r 
dill  Tlia  >ork  U  diiidwl  inia  In  |«iu— (uaJ  In 
tiMlili  and  (dad  In  du>»a.  Dr.  T«a  tin*  K»l)i*r*d 
■VBtlhT  (mm  ml  inartf  r*  an  Inmaaw  amuunt  of 


lutAil  tatBTinailon  nkicin  a  comiiarMliilj  unaU  I  JnwiuU,  Fab.  1,  tWO. 


•rnn^M*,  aod  ha  hu  arruiBMl  aad  ilftalad  bl* 
niatetlali  with  (kill  fat  ihauM  tit  lb«  iinMiUoDar. 
W*  hA*D  Hldom  laen  a  iKwk  whivh  mora  that- 
DU«blT  nallaaa  Ika  nldacl  br  wbUli  N  n*  vrltlaa 
(ban  thli  lltUa  work  «f  Dr.  TMu— J>riilM«  JIabtal 


h 


BICIiARDSOA',  B.  W.,  M.D.,  LL.  J>.,  F.R,S., 

Pr«T«ltiTO  HcdiOinO.    Iii(ni«ocUraroliuncol739  pa^cm.    Qulb,  M;  IcklllM   IS. 


Dr.  KlnhudMn:!  bai  luoiiipjod  In  |inKlu«lD|t  a 
VOrk  «blc«hl*al*TaladlBcouE<B(TiLoi],cfijDprBbaa. 
■It*  In  (mp*.  lelantlllc  lii«haraiit*(,>x<ManaUela 
Wnuit*ni*nt,  and  vblcli  li  wrKlva  loa«laar,mD> 
Claaand  i(*auiii  miuioar.  Uanlnoai  iba  happr 
feanlt*  oi'iinH'UnglhaplUi  of  what  i>  liu<i«u  nu 
fta  aobjvt.  mnd  n1  iifatlng  II  In  a  fDo>i  nimpln. 
tnuilltviii  and  (irHdMl  lOrm.  l'h»r*  i>  nerhan 
DO  ttmLlar  i<T}fk  vfliwn  for  ih*  nafraf  piibrio 
tbatronlaha*  iiu'-'ltaconipIflL*,rp]lablaand  Inttnio- 


iliaiwllection  of  data  upon  Uin  •tI»aM>  ecmaiaa 
li>lb*noa,ibalr9rlclnfeucau»a*.aad  tlia  in#«»ur«a 
tor  thalr  pr*>*nllaa.  Tn*  d*i«rlpllnn>  nrdtaraaaa 
a»  alaar, aba*l* and  •oholarl;;  ilia  dlaomsliinaf 
itie<)uB>ilaDa(iI  Itaua  la  eoiDBrvheoilTa,  maaWrU 
and  (ully  abrnait  allh  lb*  lalaal  and  bvii  knoitt 
Mt|>»a  iha  •iibjnci,  and  tha  prvnnU**  inrawina 
•rlittcd  ar*  BiMDraM,  tinllFlt  and  F*UaUa.-.71ta 
dmwicait  Javmaliiflii  JMimJ  SeiMiu,  April,  U»L 


TffE  I'EAB-BOOK  OF  TREATMENT  FOR  189t. 

A  Comprehensive  nnd  Critical  Beview  Tor  Praotitioaora  of  Uedi- 
Oind>     In  onv  Viiw:  viiliiiii'  iif  Is/i  |»>km.    <.:lotli, tl/i').    Jiulrtailf. 
,*a  For  ijicoinl  inmiiiiituuuiiJi  iiiili  j'enodiisia  ec«  pafiO  1  aoil  S. 
Tba  ptvirni  li-Tii-,  iho  >«T>niti.  tiu  U*n  In*'  tani'yloraeomineHdlinth*f»*aaBH«*ama,i»hleh 


eraaaa  Jby  ffi'>fBlbi*n  runir  rmu'Irt-l  and  IVfljpaKVP. 
iMst  tba  <ir]t;iEiaJ  |>Uii  njf  rha  book  li  nol  ■iurtil. 
It  «ltlL  tvmaJni  n  ixik^L*!!  fpiioiiid  ^t  ilio  ?iiL«f 
arUri*^  t>f  lJi»  pjMl  i-*4r— nrtlH^lB*  K^CtkHod  and 
■plCiimU4d  by  a  iilaff  4'if  coDlrLbul4ft  OL^cti  lA' 
eludM. many  ur  Ltia  tvit-knocn  and  ablrvl  apa- 


n  ooaitdfrr  In  t>*  aspcdor  to  anf  «f  lia  prtrtaota- 
aor*:  mora  pmstlrd.  mora  ciB*n>llr  UMful  ta 
iTanilllaDan  Ili**a«ilonBl«diMr*haTa«oaJiD*4 
thalr  aiiaailon  lo  tulfllllagih*ah|>oto(lha  booli^ 
ailiMOM— Ih*  imTliUaa  at  u  •pltaow  tt  tha 
.._..._.  _         .         ,        matt  pracHoal  and  uaafOlntlhaiDcdlealarllel**, 

OJaJliU,  and  Ihcw  i^aatUiiian  liara  wlMly  kapt  ia  i  vl  til*  pwl  r«ar,  Ibr  the  UM  or  «■■  ith>»*  prv. 
misd  litat  Ui*  1  tar  llwk  I*  lot  praoUUeaan^  and  ,  lira  doa*  not  aUaw  lima  IW  U>*  aindy  <■!  a  laig* 
Uwy  tar*  «It*o  obai  asuial  praollM  raqulraa—  nnmbMot  hDmaaod  CxalBO  RiadliW'joDrDala.— 
omJuI,  w«rGab1e  iDformaUoo.    W*  h«t*  DobMl-l  n»  IfMui  Jtifitmt  tf  MUmA  Selmft,  Hay,  Iwl. 

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aCBRETBER,  JOSEPH,  M.  J>. 

A.  Mftnual  of  Treatment  by  Massage  and  Uothodioal  XOBOlA  Bz> 
•rolM.  Tmugliilpl  I'v  VValtkk  Ue»i>klih>h,  M.  D.,  of  Sen  Yufk.  In  ou  handmns 
OMBto  raliUDc  i-r  STJ  {ages  "i*^  '^^  ^ae  cugravinifa.    Clidli,  f^lTS, 

mUXANtm  MXMCAL  itOTKSUtD  RBFLCO- 
TluNH.lT0Le*a.M.«H.    ai>lk.lUk 

PULLBB  OM  DI8KUKB  OP  THE  LCItOB  AXD 
AIR-fAaaAOBB.  l^alr  PaUiorofy,  PbnMI  U- 
•naat^  ByKptam*  and  Tr<«lin*nt  riom  tha 
•Mao4  aod  raalaad  Safllah  •dulno.  la  ••• 
onaro TCIniaa of  <tt ?«<»'•   C>mIi,IU«. 

WALBBR  OH  TBB  DUSABSS  OP  THC  HURT 
AMDORCAT  VBMRit.  Thlri  AnariCM  •dl' 
lion.     I  n  I  *nL  1*0^  <!•  pp.    Oath,  (iLMi 

9LkI>EON  blPHTDBKIAi  Ha  VaMN knd  Ttoat- 
nanl.  >lil>  aDaecMietor  tli*  BItMn  o(  lial'r*' 
ralrnvo  la  **rliiu*Caunirta'^  Swandan J  r«TUa4 

•dnioa.    la  000  UBo,  *Di.,  lu  ppk    couh,  n.ai. 

SMITH  OX  CONSUMPTlOHillaKartraad Rama- 

diabia  8la(*t.    I  <^.  1*0^  Ml  pf>.    Clolb,  (uO. 
LA  ROCnX  11.N  P.N-EVM09aA.    I  toL  «T«.«f  MP 

tut**-  (.loWitMa 

WILMAUS  O!)  PULMOiCAftT  CO!ISVIiPTIO:ii 
11*  NauiTL  Varlallaa  and  TraaUDaot.  Wllkaa 
•oatpalaofs**  than— «  (aaa*  10  *«*«>bIU>  Ub 
dntUlM.  taoQ*tT«.*al.at»in.  OaliLMai 


•niminr  isTiuii.KCTHin  to  tub  wtvox 

OPCLIMCAL  UeUIUlNK.  UBlaiaGulda  to 
Ih*  lB>«MlMUoa  uflflHaM.  Iboub  handauma 
llrao.  tolum*  ol  It!  paso.    Cleib,  fl Jtk. 

I)*V1.T  Cl.IXlCAI,  I.XCTI.<ni«  0,1  VARIOUS 
IMI1)KTA^T  MHIUHia.  Uy  S.  &  Va'to, 
U.  II-  Ediud  by  P>*a(  a.  P**«^  M.  D.  gieiai 

•duioB.   icaiD.  an  picH.  ctoUi,tLTa 

TODErSCLriKlCAL  LKCTl'RKS  OH  CNtTAlH 
ACttTR  DUSASES.    lo  ooa  o«ta*o  toluniB  U 
Olotb, 


rAVYVTRKATEBKOK  TIIS  PUHCTIDHOP  Pl- 
6B*T10Xi  ll>  Otaardan  aad  Utair  Iiaaueask 
Fncd  lk*afooad  LoDdoaBdHliio.  UoaaooiAt* 
nlDsa  «(B*  paCBL    nMh.UOO. 

RAHLO«~a  KAXVaL  OP  TIIS  PRAOTICK  OP 

MKDIcidK    With  aiHIttca*  tp  a  P.  Oioi^ 

M.  D.    I  T«l.  Iio.,  pp.  MB.    aolh,|UCL 
CBAMBEBtl-MAia'ALOP  Dm  AHKRBOIMRH 
TK   HBALTK  AHti  MlrKHUM.    In  ooa  haad 
t  Mttro  nHuBB  of  m  pp.    t^ou,  ti.n 


fnttua'  nf  Un  Pnnapla  a»<  Prttiu  if  MtUmt  m  iMIaw  flwpMal  Mt^mA  CUtft,  H.  f. 

A  Uanaal  of  Atuooltatioa  «iid  ParauMioo;  Of  iha  Phpleal  IMnfi^iil 
Di««wc*  oftW  Luii)D  Hod  IJnui,  anJ  of  Tbondc  AMoriuo.  Ncrw  (fifth)  edkte 
Elihcd  I7  Juut*  C.  wllaocL  M.  D.,  Lecturer  <m  Pbjvlcil  Diaipx*'"  '^i  ■'•<>  J'lhn* 
Mfxllcml  ColUn,  Plillnilftlplti>.  In  OM  kaMlMme  njrml  l&ao.  ruliiina  vt  274  |Mg«i,  vU 
12  i[lu>ilraili)as.  autb.fl.TG. 


Tkl*  ttUla  bMk  Uireash  tu  twImh  edition*  bu  I  onf^tam  of  ppof.  niBl^  iDTHllnUoMi.    htM*- 
~     '    doDO  moro  u>  adfium  th*  «cImio*  of  4Mto  n  li  •x(>*Uhi.    Ii*  tain*  t*  oIimi 
oiffcnUea  cf  Uio  cImM  tlika  u>y  olhar 


proistlr  doDO  moro  to  adfium  th* 
IiIi/bMiiI  oiffcnUea  cf  Uio  cImM  tlika  u>y  < 
dM*Tt»U<«  upon  UiB  niUM*,  aod  no*  la  lu  flnb 


MIllMi  II  u  *«  DMT  p«r»tol  M  ll  fan  b*. 
DoMlly  «Hh  which  ftvrlous  •dtlWaa  vera  «« 
■bu<n  no*  lb*  imftwilan  kr^neluod  ilio  tiKir- 


tte  Tritt»»*l  nt  lb*  omMtIbI  aM 
«andM  »>)•  of  axfTHalon.    J'WUw 


dMiVMUl 


drMH 
mtmtr. 


JaMary.UPI. 


BT  TBS  BAUB  ABTBQB. 

A  Practical  Trsstiae  on  the  Phjsioal  Ezploratlon  of  the  ObeM  tad 
ths  DUjpoflu  of  DiaAuea  Afltetiag  the  Baapirator;  Organs.  Scamd  atd 
nrbfd «illi]i}(i.     tnofi*  luiiuWin*<>oftavo*nIiiiii*of  Ml  pagva.    Clotb,  $4JM). 

FbUiiiris:  It*  Horbid  Anatomy,  EtfologTi  Brraptonuttlo  Evonu  and 
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TrMtmi 

Jn  oM  oouvD 


A  Practical  Trontiso  on  th»  BiaKnoaia,  Pathology  and 
IHseaaea  of  the  Heart.    Scoood  Mrianiuul mUiskI adidnD. 
of  6S0  pagM,  wUli  a  plaU.    Clolh.  H 

BauTS  OQ  CoDserratJve  Kedldne  and  Kindred  Toploa. 
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iliJOH^A'^,  LRXXOX,  IT.  n.  C.  8.p  JB., 

Si-  .!•  r^vinmt  M  l*t  Ctnlral  £«ml*«  DlrvM  out  Jfiir  ITmihm;. 

A  Praotiool  Ovide  to  Dlseaaee  of  the  Throat  and  Koee,  tnclodlng 
AMOolated  Ailbotlotu  of  the  Bar.  New  (thini)  and  enlMg«d  «dition.  In  oaa 
inivrtal  ooUitd  Taluate  af  731  pagw,  «iili  IN  illualnitioiv  in  oulor,  and  SSUi  anKtariiiy 
oa  wood.    Ctnth,  |S.aa 

n*  UilH  odlUoBcf  Mr.  Lraaoi  Snnni*'>  in- 
•trumlT*  uil  aiUtilc  <MTk  as  "TkoTfanaiuil 
lu  l>lnm«ii"  a|>p«itr>  anilar  Iha  lUla  ol  "Tb* 
ThnM  and  Ndm  wd  Tholr  RlHatM.-  ThM 
oliaoRi  tiv  beta  randwHl  d**lr*lil*  byttie  ad- 
TaacM  wio  4Uf  IDR  Uio  1m«  iIhwM  In  ildaalacy. 
Tha  nwal  (MiilAai,  wbleb  axland  M  apaafdiaf 
ltd  paa«v  ■<*•  ■■  ■  •>•«*  *pao*  Ito  bnl  aooonnt 
ot  liM  pTHanl  pcalUon  tl  thIs(iloc]r  witb  wbtth 
■•  •»  aoiaalBlod.  Tks  •ninflaa  la  IMi  laaad- 
Him*  *«taDi«  an  of  Uw  hudo  Msn  ordvr  ■•  boi*- 


Uif*.»M4  man  aammu  Ihan  ■•«;  iktj  m 

aatU  la  bo  of  tha  araaUil  •wlMaao*  u  Makr  «»• 
Id  md  nBMMlMwn.   TtiaiB'CTUM<at».  oHhof 
Sinrad  M  dowrlbod,  ara  tboM  wbub.aalb*  nrnll 


of  •■pwtf«fn,)lr  Rrt>«na  h*>  fmnit  10  bti/IU 
CtaalMtalUJITladlmBWM  aiii]  (nwUni'ali  IfevT  W 
iniw(»tenpl».fooiiioBitfwaud  —.tly  li»|W  1  ill 
patDUof  mnvh  Impanjuin*.     VTa  liaira  oa  a  ktm» 
socaiMo  aot^cMj  Uir  bMallAi)  OAd  inMo* 


ef«l  plMH  draws  on  Mooe  *  - 
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TolatS 

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cdlbM 


■nUacM.  Mr.  Uin»Mi  Br(ni»*i*u^>n>n«UM 
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•re  KlHl  (o  t*ara  Ikat  II  I*  balaat  uaaalivilM 
ri«Beh  s>4  Oerinan  —  Tht  ffVMie*U  IhM 
Jtuntnl.  \ngiut  I.  Mft 


ffr  rivji  S43IK  A  crffOA 


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Cbdh,  $1.SI).    Jurt  riui^.       

SELLER,  CJML,  M.  !>., 

A  HandbixA  of  Dtagnosla  and  Treatment  of  Disoaaea  of  the  ThMai, 
note  and  Kaito-Fharynx.  Third  edition.  Inocia  Iwadmne  njal  ISmo.  raJnaa 
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Piaeaaea  of  the  Throat  and  Naaal  Paaaagca.  A  (toiiUioilia  [Kapxafanl 
Tr«aUncnlnf  AffacliaMaflll«Pll■l7»,<fiK>pll•gD*.Tr•a■H^L>ilvnsllml  Nana.  1\M 
•dllhm,  tli<>r<"i|[bl7revlBei1  and  r«wrili««,  tritli  a  larKvanoiMroi  naw  llluttnaJaa.  la 
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0B088,  B,  B.,  BT.D.,  I.L.I>.,  MJ.C.L.  Oxtm.,  LL.D.  CMiMk 

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ans  ft  Cd.'s 


BOSS,  JAJIES,  M.Tt.,  F.R.C.r%  l.L.l>^ 

A  Bftodbook  on  Diso«*os  of  the  STorvons  Syatom.     la  oiia  ocuto 
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Til*  kocfc  bWon  UJ  ii  MiUII«d  la  Ux  hlfliMl 
WWiHwiUtai  II  !•  p«lnMi>tIa<,  mUdiiSe  kad 
•■(■•Alkc'y  «<>iiipnh*iwtit*. — iT<u  Fv*  JMant 
JlMnaJ,  J  air  ID.  IM». 

ThamUinr  luu  ranilarwl  >  riuI  Mrrlo*  to  ilm 
vntamiaa  tv  eondnnttiiK  ■»<>  *"•»  voliHaa  ttiv 

aMiHl  Am*  farulnlns  to  niaivlagjr  ud  D*r>- 
I    itflTIT-  W  DtlllCmMKi  It    III*    prXHtl  tMtltk 

Kli*  hw  (iMMBiled  loplfluclnK  ■■aikMooM 
t  *nd  Hwiloal  y*i  kImUAc,  oUhuui  •DUriiiK 
IBM  Ika  •IbmiHloD  «f  Ihcariau,  er  bardaDlof  liw 
Btoilwlih  «oui«l  qnwtlanii.— nw^h  ITaiiMliMd 

ThU  •dmlnbla  mrk  I*  lalandBd  ibc  MiKbdto  of 
■ttllcln*  an-1  (or  niph  owlloail  aira  u  !■■•*  no  ilm* 


tet  iPDKiliy  iieaUMu.  lu  ili*  pr*unt  laaUDM  ID* 
ilul;  CI  aiiMiElas  Iha  ib-t  •(«•  flf  ni*i««BJ  u  iK* 
•IllHwl  Af  Ih*  naDiat.  and  ct  ahtlitctiiR  Iha  de- 
xriptlMi  «f  Ita  •Dnnrrrii  vpHto  <4  namiu  tfl>- 
bHU  |w>rn>ni<*'l  «llti(in|(<iliiraklll,  wid 


Uw  imill  !■  ■  DtiBeix  uid  pltllaH|>lil«l  ■olA*  lo 
Uia  d«fanin*n(  ol  ncdlala*  n(  *lileli  u  mala. 
Dr.  KOH  holda  Mieft  •  hith  mIbdUHc  (oalltoD  Uial 
anr  vrlUntt*  wlilflii  Imm  hia  nma  ara  naliirallj 
•i|«ol*l  to  han  Uiafmpran  nf  a  pcwMfnl  lalal- 
1«(?L  In  anrr  put  ihl>  handlmik  m«fla  iIm 
liltthail  t<mH,aiid  will  nodauU  ba  Imid  of  Iho 
KTiaial  raloatothemiJeniaa  wli  a*  to  Uia  pnt^ 
SUuiwr.— Sttnkiity*  JV«AmI  Jearnat,  Jan.  Ufl. 


MAMJLTON,  ALLAN  McLA2fB,  M.  J>., 

Au-kdi^  Fliymtbmal  in  B—p%IM/ur  ^MiplHm  uid  pBrta^tia,  a^ttfTi  Umd.  I*,  t 

HorvouKDiaeMM;  Tbi-irDamptionuHlTreaUarot    Heooiiiledi(km,thDrcinBblr 
■vriMd  ml  rewritten.    In  oni>ocL>Tu  voluiDeofARS  |*gf^  with 72  iUiMtntiow.    CloUutl- 


Whan  UwAnO'liO'iii  nl\h\-ti~^  IhhiIi  •I'lirani'l 
«9  wtfl%  11  aur  tnipliaii'3  ehd^rHtruauL  aad  tha 
■Nml  aitllhin  •n^aDCHl"I^  >|«T*flauan  nl  Ilia 
took  anil  lu  auihoc  u  a  hIo  ruido  lo  •todaala  of 
Daa  of  tlia  baai  aa<I  nvoM 
iuroli>BloalJ(inmjklii,  ilraii^lua 


rriBraotorliad  IhU  IwoK  a>  Ih*  b*M  of  lu  klod  la 
an]'  langiiac*.  ■hl'h  I*  a  haBdwoi*  i«  iwiamanl 
trtMn  an  *lal(*d  MUM*.  Tb*  Im^vrtvaWMB  !•  Ite 
DBv  adillon.  aod  th*  aadlUoaa  (0 II.  VlU  lliaaiy  II* 
parabaa*  aiwD  Iv  Ihoaa  who  pnaaM  Dm  old.— 
A\\mltt  <md  Xmmlagut,  Ipril,  lib. 


•UaWal  aaiirolaur. 

WlUoMotKaillaliMi  ^ 

TUKEt  DAXTEL  HACKf  M.  !>., 

nioMrationa  of  the  InflottiUM  of  the  Ulnd  upon  the  Body  Id  Health 
•ad  Dlseoao.  DMWud  to  eludiUlo  Uic  Action  of  lbs  ttnaffioaUaa.  New  nlition. 
Tbnrouit h I <r  rpv bed  MM  rewritten.  lnuii«8*o.«(il.oft(IT  |i[>„«iili9a>l.  plats.   (Jloih,fX 


Ii  la  ImpciaalMa  (opHHOthaao  iDUrcallna  chap- 
Mr*  wlUKiiiibalsfffoiiTlaooil  of  lha  aulhor'kpar. 
fcrt  •lD»riIj',lmp»nlalH]r,  anil  Ihoroiigli  mantal 
n>«>  It.  Tnli*  haa  aihlblwl  lha  raquMla 
iBOOBl  Of  aclantlllD  addraiB  oo  all  ootMloai^  Ud 
•ha  «or*  luirinaio  lha  pliBaummatko  mora  Analy 
ha*  h*  ad)i*ra<l  to  a  phTrloloKiaal  and  rational 


tn^lhod  of  iMprprMMloD. 
'   daduciion.  ih< 


OaUad  t^  an  onll^ 


uWjgU, 

taOHj  ha*  rMhUmodnr 
■oianwaoiMllnWcHltniidnniBln  In  |NynholHT. 
nrailaiialir  Otwidanao  to  rharlaUna  and  •mnlrlcab 
Thla  bnak,  wnll  MSMlnd  and  aril  wrfMan.  Mnit 
eonnoad  Haalf  te  arm  UioiiiMftI  uvdaraiand' 
|08.-.V*H  r^rk  Mtdktl  AwimI,  topUDbar  <.  IMt. 


^' 


GRA  r,  LA  yDoy  carter,  31.  i>.. 

A  tactical  Treatise  oa  Dlaessee  of  the  Renroiu  Ssratem.    Prtforing. 

CLOvsToy,  xaoMAa  &,  jc  z>.,  f.  r.  c.  p.,  l.  r.  c.  s,, 

ladHrn- ua  JKaMal  iMM*a«  ia  (ka  IMf*^  4f  WkAmj*. 

CUoioal  XiMturM  on  MoaUl  DiMuee.  With  an  AnpcDdii,  oDoiAialiiK  u> 
Abatractof  tbf  HutntMoTlli*  Di^twl  Sutw  mnd  of  ihc  Sovoral  fiuiM  asil  Tcrrilorie*  t«- 
kting  to  the  CuMwlr  of  tfa*  Iimdc  Bjr  Cbarlb  P.  Foiaum,  M.  b.,  AMbunt  Prefwnr 
of  Uanlal  PiMwea.  M«d.  Dtp.  c/ Harrud  L'ni*.  In  nnehaodaonwocUTOTolusiiiorMI 
MM*,  with  «ifht  llUioctaphlc  JiUlw,  four  of  wliidi  arc  beautifiillj  cotorail.    Ctuth,  fi 


tk*  pfanlilonar  aanll  m  th*  Mndanlwlll  •» 
«*f(  lha  fUa,  tawtldal  waclilnt  of  lha  Mlhur  aan 
fcrvard  Map  in  lha  tllonliira  of  loaaoliy.  Ii  L* 
I«fraahtn(  io  And  ■  phjraiolan  of  W,  t^nutlBD'a 


llif  c**"*!  pracUMontr  In  inUlBB  hiaa  loa  diM 

UMl>  and  jndJcaUnii  the  iramnaBL  if  itlillyh 

maojr  vliatvta  and  deutntul  «*»•  et^BMBUl  -11^ 


To  Ik*  Ataarlcan  raadar  Hr.  rataaaa'a  A^ 
pnriii  »M*  fliaallr  to  Ih*  nlat  at  Iho  ««rk,  and 
wlllin>k*ll*4«afrMa*ktdMM  to  mry  llhiarv. 
-^■■■^aaa  J^rtjlnjil  JauiM,  Julj.lih. 


•RHriano*  and  hMt  Muurtion  tl*lnK  th*  twd- 
tiilt  oo«M  a»on  rtleti  hli  aiparlosoi.-  ha*  baan 

ead*d  aiuf  hi*  mauiit*  Jad(manl  aaiahtWitd. 
;h  alfnlral  obaariaiinn*  cannot  hiil  b*  upalSil  lo 

|0r-Dr.  FoIiKuo'ii  Aitlrael  tatf  aito  b*  obtninod  ncpanUlj  in  ono  octavo  Toluaw  of 

IOS|ncM     Ciolb,  11.60. 

SAVAGE,  GEOBGJB  H.,  Jf.  D., 

LMwrr  oa  U.^ial  DftittmalOi^t  Bttpttti,  Lillian. 

Inmuciity  nod  Allied  ireuroeea.  1'rBAi<»]  uid  Clinical. 


la  MM  ISnwb  ToL 


rfl»ltiuM.»ltli  ISltliM.     CIoUlRXM.     BM&Tica^aMiMf  JfuMwl^MNSt. 

■    farafUllraalaelad.andMtracudalrai 


Aa  a  h'aa'dbook,  a  fsld*  lo  lha  pni'lllliinar  and 
■     ■     ■    ftiH 
o»  ... 

•hanMorlatIo  eltaniaM,  Uia  Illiiainiitta  run  are 


aMdaot,  lha  bonk  fulltli  an  admlnbl*  piirpiM*. 
Tha  Maov  knn*  of  Intanlljr  am  dMcrlbnl  alia 


•UnODli 


I*  oiaiyahor*  BivamnL  |>T.an< 
ua  Km  >rllt*«  an  auollani  manvaJ  ^«  !»•  jmr- 
uitonotaadatadani  —Am",  Jtv,  efIntm.,Apr.Jt. 


In 


PZ.J  ITAIR,  W.  S.,  .V.  IK,  F.  R.  C.  P. 

The  Syatematio  Treatmont  of  Nerre  ProetratloD  aod  Hysteria. 
on*  handiDfue  anwU  Ittno.  voliuiM  of  97  pogw.    Clotli.llJW. 

kl-*»l>l^>fll>ON  IIORAKITT  AKDn*TUUT-IJOiagrtTLI!ll(UI.UI»EilVATt(MniO«  TVVC- 
MK^T.     I.of4UMaM  lha  TrHtMtol,  IMIsall     TIOKAL     XBkVOUS     DBORUBWI.      ' 
as(f/.*CxLa'fn>anar»UMM.  lB0MTCt*hUi«.\     AlMIMan  UMMn.     \u  oiK^iBte 
I    #M»*  opiatw  rafntna.  I     Wwn*  at  Mh  T««M.   CteNb-Vkia. 


£OA£j;r.s,  JOHJir  B.,  Jf. »., 

Tb9  PriDOiplM  ADd  Prootioo  of  Uodera  Surgory,  For  th«  w  ofWlirfiw 
and  PnetUliMMr* <>r  M*cllcliw niki  Kurj^ery.  In<uie  rtvjr  h»»iliDiBc  ticuTo  TolacMcf  TN 
[■««,  vitti  60t  illtutmioiu.    Cloili,  HM;  lMlb«r,  $V50.    JuM  rendf. 


InlUmnck  tb*  villi  ir  hM  VadMiorVd  to  cl>« 
lo  I'm  ko'*'*''^  "<  "i'"!!''*"'*''  ''"n  *'■■  doctruM* 
■■A  yfiifv^urM  ot  aiMlarn  Hur(aty.  ><•  >•«  mkt* 
(I  ■  vorli  4h^/IwI  Mor*  f«p«cUMj  lf>  ir*n  i>rv^W« 
(hail  to  <>»  UlMOi;  o(  •UF^fir.  IIl<  ftUD  tu*> 
«ip*tl*iio*  liifi  a^wd  tnuiy  nttijM'l*  fHl«r**la 
th«  ooik.  It  «ODtoJiw  miiar  ptaelWal  nttnW  la 
illii|CM»)>,  vhWIk  mdiv  il  Ih*  >D<f»  talusM*  lo 
tlu  pnMUUbnar;  viJ  l)M  artUaiMliMlon  abMi 
p«mi>4M  lb*  irliiJ*  mk,  los*l>in  irtik  11* 
litntMiiXr.  POtMOM  Id  vahi*  M  ■  ituilvnr* 
■nasiial.    Tti*  Um  (hM  Uil*  vorK  Is  amiiiMiitr 

r<-IV>l  nuuM  b*  loo  flrooitlT  ■mytmiiil.  It 
mo<<r&,  icil  K>  fl(  tMi4il<m  I*  thM  g»ii«i«l>y 
imBMil  wd  Konh  thai  kVvrit  IWI*  oppanMlV 
(grMcawlon.  Itwlil  h*  ItMinc,  It  !•  tUn  tiA 
««aalM,rMt>ilL    Thn  MOk  tt  (BtliM  lo  ■  plM* 


In  nudarn  *«r|lnl  tlMmlani, — At»nl*  tt  Bnws 
Ju  ■■•(. 

Thtawerk  It  •T(47r'>R>'>nii*ntlt«nrM*alH 
fftatnl  MirRv^y,  bh^  wiIT  <i'«i*iilrii-  nawt  «lu* 
tMOnib*  rBM|HJtuii  by  (ba  bnfwalxs.  I>  ten 
llMnHiilhIt'  \nMotl  <il>ar*oUr,  Uw  MklMUm 
Mini  >flbi«r*}*ilstii'nt.  M*  0<«<>iu4aUMiM 
WtoM  WIIA  IhOM  ol  ina  l*»illM  |ii»nlllwiinl 
lb*ail,**dlW  llisnlura  l.  riilljr  npIaMlthtia 
taoort  dactrlBH  »•!  ni*Ui^<  uf  pnaUM  ii<a< 
pr^wnl  dv-     '■>*  ([•'^•■'^<    nrivinmaal  IM 

ikli  rala,  lad  (ha  «ii' .laatn  M  HI 

ctaaaad  pra/^ilcal  laa'  <il<lv| 

Iftldt  aBllratr  alia*!"  .      i-rla^t 

bta  maamm  la  whMi  i<-  in-  iriua  ln4 

ilMMnaai  ar  U*  mrk.-jr*Kral  AatM,  t^  V, 
U»I. 


AHBHVRST,  JOltX,  Jr.,  M.  i>., 

iljrln.  /V,i/.  «f  Surftrjf  ami  QM.  Arfiry  la  FJaif.  v/ Pn«L,  Air^aM  fa  lAa  iVaaA.  ifa^M 

The  Prlncfplea  aad  Praottoe  of  Stirgery.  NVw  (liah)  ediUoo.  calaqiii 
■ad  tboroughlr  tvtHKl.  In  one  Urge  uwl  haiiilwni:  ocUtd  rolume  of  1 H4  MM  •lit 
64S  UliMtruioiM.    ClMh.fflj  UMlier,$7. 


A  camolaW  and  i 


I  aMallaat  mtk  an  ■uiytiy. 


Il  t»  esty  nacHiwy  la  aiamlua  ii  la  *aa  al  miM 

||q  uio»llaD»  and  r*at  m'rM  nithi't  M  laiVboak 

.  (h  lti«  atnlani  at  a  Enlda  tor  Ihr  (ananl  pnicll- 

■  ttftfjar    11  f-itly  ooDtidan  Id  datait  orary  iur^cal 

I  Injury  aed  dlwaia  (u  alikli  th*  b«dy  i>  [labia,  and 

'rttrty  adv^^  la  *'irir*ry  vnrlb  n^liif  la  la  ba 

bund  In  lu  proparplt-n.    Il  U  iiaqumionably  ilia 

uiaad  ntnai  mniHTti^  «FD(Eta  Tfiluniaoa  ■iiri^rr. 

.  I  Itia  RnglMi  lnnK<ia«a.  and  '■■' '  '■■•>  radlrn 

|)inlcontliiiifldap|fr*tTiatian  al: :  'luttly 

tbnand  —  j#>BiA(Fii  lyitti-turi 


"rtla  It  ona  o(l(ta  fn  — 
Um  many  «all-ka«n  i 
II  PBinl-hM  In  ■  ■-'  ' 
ooaiipFTbtealva  da*ciij-..<.r. 
tin  noil  itcnarally  anii-luy<' 
tiirglval  alTvoln^.  with  a  i 
prUi«t|d*<  an  ufalfli  l^ — 
Mafd    Tbv  aelln  >a  r  1 
■od  •  uamkcr  «f  &- 

ft   ^- 


'•:tara*d  wM  *t 
K***nl  •arrt- 

i-cT    a  dMT  •» 

iHaariti 
jnriwaw* 
Iran 


Ibal  Bnally  anbi 
QaWaantl  Lm»ttt~ 


CbfUt,  LXn.  I*.  IHi. 


.  •;  1  nruM  ••• 

raliilly  rn>  < 

HIM  la«i>iia« 

I  ef  II 


baMk- 


irnriTT,  iionr.iri.  m.  r.  c.  s.,  etc. 

Hituual  of  Hodorn  Surgurjr.  TwelUi  odltloii,  ibomighl^  revtatd  brSru- 
Lnr  ttuvi>.  M  i;,  !1.S^  !■'.  K.(:.8..  In  one  Sra.voluiM  or  9tt5  iia«M,  villi  3T$Ulu«» 
tleni.    CUii,  M;  I..>ih«r.t0. 

ItlaoHaDtlftlly  a  Ti«<ir  heat,  TairrlU''n  from  ba> 

SIbMu  M  aud,    Tha  aditw  lua  broucbt  hi*  ir«tk 
BMlKa  lairM  data,  and  oeoity  aiory  tubject  on 
nfah  Iha  alud*nl  aii'l  [trar(Uli-D*r  mfwid  <li>*li* 

ft>OA■llll  a  *urf loal  V4if(]i7i«.  ha>  fjiind  lo  plar-* 
ra.  Tha  Toluaw  rinw  aiili  alixil  larniy  ■<■■•>• 
«f  fannu-'M  (oTcrtnit  a  brotr:)  raac*  vl  pracltfal 
[Uaranuilea.  Tha  iciidanl  will  And  thai  Iha  naa 
tniltl  It  lo  thbt  B*aaniil4n  what  iha  old  CAa  ma* 
to  Iha  fermar,  aad  n»  hlcher  pndH  d»hI  b* 
m»ett4»t  to  a>r  rnluma  -XariM  &ra«ai  MtitiatI 
Jmmml,  QMobar,  1»T.  


l>nlU'*  Sii()p>ry  hai  baan  an  axpaailtncly  h^ 
IM  vork  In  ih*  prattHiMa,  li  i>  *iaia-l  ikaiawV 
raplaa  bar*  bHn  Mid  la  Ennlaucl.  aiiila  la  Ha 
t:Biwdae*i«>LaTar  •inoaluMrwi  i>tu*.iitn*l 
■ip*d  at  a  taiUbenk  la  a  Tary  larw  *>iaat  I 
lilt  Ih*  l4M  mr  to  Ihl)  «Mntry  ii  om  t>  ' 
■ppRclalad  ihat  acopy  waa  IimimI  by  UwO 
awal  (AaachtuTcaoo.  Tha  poiwni  adlUta.  • 
II  ha*  iNaawiia  ItaUrH  r^-uliar  tn  (ha  wart  a 
Anal,  (•mbn^lat  all  ranni  dtMnrartoa  la  ■MiWIJi 
an.l  11  tally  up  10  lbs  llmea— ClMMaM  MU 
.VflH,  Saptaatbar,  UBT 


OANTf  FREDERICK  JAMJB8,  F.  R.  C.  B,, 

Smiar  Air^vi'*  lo  lU  AiyaJ  Ft—  B<ttpUtl,  £anA>a. 

The  Studflnt'fl  SargtTf.    A  KaHnm  in  Pom.     Inotw  aiinuv  ocbinfoUnt 
of  mS  pagc^.  with  159  ongnTingL    doth,  tS.'&. 

OBOSS,  S.  D.,  M.  J>.»  tL.  !>.,  D.  C.  L,  Ojetnu,   LL.  !>• 
Cantab., 

*MnhM  /■'•few  ^  JiWyry  M  U4  Jtftrum  tltdmU  OMf  ^  I^MtadalpMa. 

A  Srstem  of  Surgery :    PacbolcifUal,   lHi«niAlc,  Tlitnii'mtle  mil  0|Mmllt«. 
Sixth  nliiUin,  thurwiehl;r  rvviwil  and  ^itatl?  imPTOTcd,      In  tB<7  Urge  uhI  MMUhlll 

Erinud  imperial  ocUto  roliieae*  inntBining  23n  pgei^  illuilraUd  Sij  1933  •cynutlfb 
IroBUt/  faoeiBd  in  laalber,  rabrd  Ivmln,  lift. 

BALL,  CHABLES  Ji.,  M.  Ch.,  J>ub.,  F.  R.  C.  8.,  IC, 

fi*rpt(ii  aad  rbat**'  altfir  P.  /hn't  Il*tp4i-il,  l>^U». 

Piaouca  of  the  Rectum  and  Anua.    In   one  iSiuu.  Tntunv  at  4IT  pn. 
with  M  oil*,  iin.1  4  a.\i>nd  |iUlw     <:k.lh.  gJ.SA.    Sea&rwarf  CHmmU  JCMMatt  H. 

OLBNEY,  r.  P.,  M.  D., 


Orthopcedio  8uTtraTS<  TDitV\M<meiA  Vvgst.ti.wniniand8nid«fiia. 


Inumhaa'- 


kTiOKS — 8urr«tT- 


21 


MBICHSEN,  JOHN  B,^  V.  B.  S.,  F.  R.  C.  &, 

The  8oi«aoe  ftnd  Art  of  Surfrory ;  Beinir  ■  TmilM  on  Riir(i<«l  tDJiiriM^  Vi»- 
«H«  ukI  OpcrMJoM.  From  the  ciitliili  nod  cnliir|[«(I  Eiigltili  (ditknu  Iii  Iwu  large  and 
faMUtifiil  ocUvD  TotiunM  of  3316  |uig«»,  lllualrited  wtib  9M  eafcrwTiiigt  on  wood. 
Cloih,  SU;  iMihw.  niwd  baD(bi,911. 

An  of  Sarf*r]P~  •>■   on*  of  Iha  I 
toolulo    in*   Eoc'lin   Ikngiiag*,! 


•4lllaB*Blf  toeflrn*  out  unTMoi  ot^nton. 
HJ»  KnM  clwHur*  In  csnlwly  eammanillDiE  It  U 
MI  nwUrI-r>MM**oa(  -Vw^  April  II,  InU 

For  Buay  TMn  tVU  filual'  irnrk  lui  bMD 
(niri*  bv  H«l*rMtM  At  u*«li*r>  ilti>  prlaeleU 
Mti-Mik  •>•  fur(«7  for  mtdlcal  »iuJwii^  «bil» 


■Tba  Seine*  MBd  t  thmuRh  liantlallOD*  IdIo  lb*  iMdlsc  «ODIlDaDUl 
ti**t  (Dialol  Uit-  \  lugiiiigr*  li  tnar  b*  nlil  U  fnI4*  III*  aarglaikl 
•,•04  >hl**<fhth  .Horiinaior  III*  clrllliad  vorH.  Xo  •lealfise* 
l«t)i  oMnton.    W*    of  Ui*  finnar  •dHlon  IiM  li**n  droivHl  and  ao 


of  Ui*  Rirmar  •dHlon  lia*  li**n  ActiffrA  and  ao 
dliearM),  d**lM  or  hnvn>rpm«n(  which  haa 
marli«4  (h*  pracioaa  o(  ■iinrrr  dutinc  the  laai 
dwad*  hk>  bHB  omluad.  TUa  IlluMratloaa  an 
miuty  and  riMutad  in  tha  Uahaal  aljl*  of  art. 
— J>><.i»iif>  JfefKal  gfti.  Pab.  K  UU 


BRTAlfT,  THOMAS,  F.  R.  C.  8., 

airanm  a^  tjttmmm  Surgrry  ni  Ihv''  BatptM,  Lamiam. 

Tb*  Fr«Ctico  of  Surgery,  h'otinh  AnMdaui  ftcco  tb*  ronth  ud  nrlMd  Eiw- 
licit  tdilloii.  In  one  larfte  murvfiy  liinJaoine  itnporial  octaro  TatUBM  ef  lOUpa^w^wlUi 
727  illiMtnLiooi.    Cliilb,  |IUCt;  l«uth«r.  fiM. 

Tha  hMitlb  odltiOD  of  (hla  mrk  I*  fUllT  abraaat 
or  lk«  UuM.  Tha  aulhoc  baadlaa  hla  anhtaeta 
«tUi  IhM  dapwa  o(  JuHgniaal  and  aklll  ithlali  Im 


•nalovd  tvTnn  "■  t«u>Bt  (oil  and  Tarl*d  •>' 
parte***.  Tha  ■•raarnl  odilinn  ti  a  Ihotalllb  t*- 
tWoaoflhwa  BhltA  prtccd*d  Ji.  wlih  mu«h  i.rw 
malU*  addad.  11L>  dmlnn  l>  »  k'^'''"!  and 
IHlwl,  and  hi*  axplaaatlon*  an  u  lucid,  aa  to 
AllM  laa  mwh  anoai  lli*  niiharl  ncdfr  of  (otl- 
fcaaka  tor  Ih*  nadleal  Undant,  Almoii  •rar; 
(oplo  la  lursar;  I*  proaoDWd  lu  inch  a  fbrm  aa  %a 


asablf  Ih*  bu>T  prantilcnat  lo  r«*1*>  aarmMaM 
In  *<r*rr-da)'  yrvUaa  In  a  thnrf  (ImtL    Ko  Um*  la 

lUl  II      '        " "         ' 


iMlwIui  uhIvu  Uivorla*  or  •upfftuoiu  (Wlilasa. 
In  than,  Iha  Kork  H  amlnanUr  «Mar,  loclral  and 
praoUoal.— OU«^  XaAnl  J^nal  b«I  fcawawr. 
ArrLI,  Mat, 

ThUbvali  li  aiaantlallr  irhal  U  rafporlaloba, 
•li-  a  manual  for  Ih*  frnrttH  at  aurfcry.  It  I* 
p*^u  I  iMty  vM  I  niin]  briboMudaoln  hw  matal 
l-raMliMaar— Tka  MttMit  /tnt,  AasaM  U,  U«. 


TREVES,  FREDERICK,  f.  R.  C.  S., 

/fnHlimn  Pnfutar  'l  lit  Sa]/nt  tUlm  Vf  SurywiU  af  £a^taM. 

A  VftDUal  of  Surgory.  In  Trvsliaea  hf  Vanoiin  .tattion.  In  ihtv  ISmo. 
TolumeL  oontaiainK  1S66  tinges,  wilb  S)3  en^raringa.  Price  |i«f  toIiiri*,  cinili,  ti.  S«« 
Slititm/ »ria  of  UatumU,  p««e  31. 


W*    liBT*    (i»rt  Iha   O]>lai0D>   of    ihlriT  lh(*a  ,  _    _      ..     .  . 

aqUwn.  la  aa  *aoyei«[aBHlc  term  fcr  tanjr  and  I  Jxta  ar*  aloari  pnoltd  lo   (iir»-h*aTT  tfp*.  'o 


rndr  rftoroaM.  Tha  thrao  lal'imi"  vn>hra«*  I 
•Torr  nrlalj  atunlaal  UhcilDiit  llktiy  m  I>«  | 
aol  «llli,  Iha  i«r>cnptia  *»  ahmi  and  I'lihjr,  and  I 


]  Iha  aaJiani  lalaU  and  tha  baclnalsia  <<  iirw  inb- 

k-naa 


ihal  a  pamn  majr  And  ahalarar  Infainulon  ha 
may  ti*  in  dh»i  '>f  ai  a  tnomtol'*  iiaoor.— C>a> 
nnmitii  £o'i"i-'Ti>-ir,  au|ubi  tl,  IBM. 


I 

I 

I 

I 


P« 


HOLMES,  TIMOTHY,  M.  A., 

Sar^rmm'4  Ltitt^f  v  l*.'fn  'I  ■^-  ('inf^t  fTi  ij   T.  T   i  *ill. 

ASysUmofSurgory;  Thooratical  and  Pr«otloaL  !>' TREATISES  BY 
VARIOCS  AL'TKOK.'^,  A3iKHi<\tK  cniin.jt,  TiionoroBtY  RtniCli  aho  iiK-CDiTm 
br  Joii.s  II.  pACXARit,  M.  I).,  Siiryeon  tu  lli«  BpiHopa]  md  fh.  Jtaapli'a  Hoiqiitali^ 
Pliila<l('1)<hia,ai*iit«il  I17  a  mqia  of  Uiirtr-lhree of  Uiangat  siDJntnl  Amwlcu  MitgcotM. 
la  tbn*  laiYO  imporinl  cvuvo  Tolumva  CDnUininf  3)3>  ilonU»eMunuiail  pun^  wUh 
ftrS  iUiHtntlofU  on  iro-l  miil  13  Ulhognuihle  |ilatM,  beautiAiH;  colond.  nie« 
■M,  dMb,  tlX.0O:  twlber,  (lil.OO,    &M  mJf  fry  n£*i»^ii>«n. 

WliARTOX,  HEyRY  R.,  M.  O., 

OwnwIraWr  ifSur^mt  atd  ttitii'ir  pa  Ai^iMt  /haauu  g^  CUUra*  la  IM  r/«  r,  qf  f  IH. 

ICiDor  SormiT  and  Bandaglog.    la  cue  rvrj  huidaoim*  l^no.  voIubw  of 
4n  (MRe*.  wilh  l(n  cngrsrtnsi,  nianr  twing  pliotogmpbic    Clolb,  t3.00.    Jurf  rtmdf. 

MAJS8II,  HOWARD,  F.  R.  C.  S., 

S*w  .Aauloal  JiVf*Hi  lo  m^  L^<irf  n>  ^aafo**  al  JK.  AorUalMMIi'a  Moi^iial,  LMdaa. 
DiMUa*  of  th«  Joints.     In  one  IXmo.  rulume  of  468  |Mg«^  willi  <H  wnodcau 
md  a  mliiraJ  ]>1aIp.    CIoUi.»2.00.    8ee&ri«iorClt»iiaat  JfaawiUmi^tSl. 

BUTLiy,  HENRY  T.,  F.  R.  C.  JS., 

4uMlaal  AarjtM  la  St.  SvliMMHtr'l  Btapiltl,  loflAn 

DiaetAM    of   the  ToiikuO<      In  mwi  I2in".  roliuiM  of  4M  t^gt*.  »lth  8  tolortd 
pUuB  aw)  3  vooduiita.    CloUi,  tU9.    8—  &rw  a/  OiaMo'  JfoMui/j,  |Mge  SI. 

TREVES.  FREDERICK,  F.  R.~c7s7, 

amrfmn  t*  ait  Uilt^tr  mt  Swintl  Ol  l/tmien  Htmptlal. 

Intaatlnal  Obetruotloa.    In  on*  iMckM-alse  iSroo.  volana  oT  S3Z  pt(•^  ritb  M 
Ulnttrui'iiM.  Limp  ckxli,  blue  odgei,  t^OO.    Hee  Smm  0/  CUmieal  Uamialt,  juft  31. 

GOULD,  A.  PEARCE.  M.  8.,  M.  It.,  J.  if,  C.  A, 

Jtauiail  Utrftfm  la  ittUlnu  /(.••j-.Tnl. 

Zlemonts  of  Surgioal  DiagnosU.    In  oat  pndcM-aba  IZmo.  toJimm  of  fi89 
pagCi.    Clolb,  12.00.    See  Sladi%u£rit,  af  UaiuuU,  i«gt  31. 


rtuiim  pRi9R.-n-Lf!a 

■UMMiy.    MiMd 


axd  r»Acno«  or 

3J«n  Hani.  M.  D.   ta 
thiMiiiM  rioui.nn. 


■ruLJunspjuffofpLnorspBaERr.  PDunit 

Amamw  Awn  ifa*  ittM  Bdtabnnh  •dlUoa.  la 


HILLKR-S  PIUmCB  OF  eVMSBT.     PMUlk 
•oL«i(«nw..«VftL«M«taMnU«Mk.  OM^] 


22      Lka  BKOTHBoa  &  Co.'s  PuBLiOATiONa — SurE«>T>  Fnc,  Oiiduc 


SMJTU,  STEPUEX,  M.  It., 

Tha  Prlnclptes  and  I^aouoe  or  Opanttive  BurBary.  V««  (Mooml)  ul 
Uuirviflf^tv  rcvi>«l  nlitiuii.  In  one  fvxy  liiuiiliKiiiic  oulaTo  raUine  of  SM  pMn»  wtlh 
10'  I'M.    C'loUi.  tl  DO;  l«Ui«r,  (i.au 

Ho  viinPT- '■d  UiB  lataal  tiiMtiauMiM  hMva  •• 

t<>'L  ft-r  1Ji4  >1(icj«i.  -  L.^a  I 

Mid  «p#-»  c»  M  )v>^) 

nuni^*<-tt;j)iftnBti;.... .- ; ...  ,.._.-.>iir  .._  ^. 
this  tvlama  vflriuDS  liplil  ■  bkim  Ma*tnmB 
plac*.  aad  Mldom  «lirila  ntMlMT.  oo  nuOM  lia 
aniuual  lh«  hUmlcmmiH  IM  pav**  in  tMit.  n 
cam|«M(MB,KXMlant  i-rlBV »'ni*TiM* T 
Umu,  wtd  Ma(iun>  lu  dwMMltr  tnuata 

aeWf.kll  OSMIiIm  M  PMBRMBd  M.— >«h4  J 

Mil  Atrfltal  Jovwr.  Majr  10.  UK. 


Tl.  ud  ivtr  'kliutil*  book  U  OBDQr 

Ihd  ^4'^-  --.-.  ^jh'U17  vtfrkAOD  mocldm  Dpvrmtm 
•Ufynry  yrt  pucluhvd.  Il*  aiiltiot  aad  puMUhar 
har*  •uuail  uo  ptlBi  Iv  niklto  11  aa  (lu  m  iHulUe 
■•IdraUand  Uialralliirta  ha>a  ^no  liap«lUoii 
pronitn«niamonBih«r«oanl  mrlra  tuiliEiidaparu 
maul  of  tmttett.  Tha  hoali  1>  a  MmiWDdtain  foi 
Ilia  cnnlArn  •(ifKHA.  Tha  praaMil,  tha  only  rwieJ 
•dlitnn  •ii>"D  in*,  iikmdu  muj  ehuiSM  Inua 
Ihp  iiriflnal  rnkiiLial.  Tho  Toluaia  I*  (naoh  an 
l»iKfd.kDcl  Ihrtrxt  Urn  t>Mn  UiorougblT  r**(M>l, 
•oaatORlta  ihQiDDn  impmrHl  ae\aoJt  In  laap- 


•  Mrmi 


noLMEs,  TuroTsy.  m.  a., 

A  Treatiss  OQ  Surgery ;  Its  Prmoiplea  and  Praottaa.  K«w  AnwtiM 
ftauUic  fifth  Bogliib  vJiti"ii.  oJiird  tn-T.  Picxsuna  Piux.  F.  RCH.  In  dm  mm 
TcJuliM  of  MT  toeos  «il)i  4^  illiutrntloiw.  CSotb,  9S-00;  lonthor,  ti.OCH 
Td  tba  jranopr  iD*inte<n  of  Uia  prolMrian  nnd  br  Ik*  ganinl  |>raMlilanBr.  (asDhlnc  ihrnaitliB 
'■■■'■"  thai  nr*  aH«urr  lol*  lioftwn  fur  Oi»  isaMM 
pruaeeutluD  at  lAa  phjrilf  his'*  oann,  tnp 


MoUwn 'Mt  nsqiulnlad  wllh  tho  beak  Mid  Ka 
marlu.  *b  tahs  pleuura  In  rwantmandlDf  It  a*  > 


9Ht%'*ty   DDin(i1«ea^  thoroKxh, 

lll(Uinl*d,  iDiHlara,  n  voiii 

niMU  for  Ui«  aoiiaan  ipMlnllit.  adwinMelr  conclie 


w*l1-i>rltt*n,  hilly 


oolhlnK  (hal  In  Dnrpraarai  k. 
•ml  LiiiMf*.  unHlnnttfle  or  iBvjn 
attJ,«H  Jiwytal,  July,  un. 


as" 


S 


inol  *Tnid  tiklnt  tJibtb*  oC  UaM  « 
•lansuihatarara,  ha  Ba*4*  nil  ite  atjl* 
nir*.     Iloi  «kit  bHiar  waMiMn  nn  la 


^W 


HAMOJLTON,  FRANK  A,  Jf:  D.,  LL.  D.. 

A  FrsotioBl  TrootiMi  od  Fraoturas  aod  Dialocatioiis. 

lioD,  reTi>«<l  Aotl  cdltLs)  b;  Stepiieji  Nmitii,  A.  M,,  M.  !>,,  Prufiwur  of  <       i^rj 

in  llw  Univenilrol  iboClly  of  N«v  Yoilc     In  one  <FcrT  linxnlaauw  ovUvu  twluiu*  «i 
pagM,wItlt  SOT  illuMMion*.    CloOi,  9M0;  1«m)i«i,  (u.V. 

Il  hM  rdHliail  tha  hIjhMt  andarwnantihitn 
■*(k  U|4u  a  dDpaxtmanl  c4  tumrt  ou  pcuUiljr 
raeMm.    Il  I*  ii«i>d  aa  n  mhi-Vji^V  in  eirry  Ffix.ti 
*ni  «Mi«M  of  Uui  eonnirv ,   ' : 
ten  boo  enlled  upODM  |>ri  r 
WhM  mora  nn  la  Mid  In  -. 
UtanbNn  Htd  Willi  iniih  ii.t:  ii  It  duuhiiu;  if 
aov  *nf)tlc*l  <•<»>(  l>u  np|M>r*d  diitMa  Iha  lual 
tialf  o*»luiy  wlifeii   toon  ocmplaiely  Hilcd  Uia 
»laaa  to  whlah  tl  vM  da*tsn*<L     Aj  Dt.  Saillh 
nya,  lU  (reM  martla  npp»at  moat  ronipleupBiIy 
N  lu  dltar,  I'jfi.'t-o.  an  J  yalcoinpnihaiifliTaaiala- 
maalofi'.'.       '  lUii  rin-lcnlcaBailailnbla 

(asI'lK'^k  I  I'ld  c-;](>n.  ancNn  ltaiir*allh 

Of  ellnKsi  '  '<>"'■  a-Infiii  ll(i>  iti* dally 

AManltln*  I'f   jhr»oiUl'«npF.     VraoiLirFt  and 

OBloadiDtia  *ra  liijitrHK  wlilcii  lbs  gan'ral  im.'il- 


j  Uonar,  tn  hia  tbrnnmltt  a*  ■  an  rvnn*i>* 
Up«A  I*  iraM.    They  Itm  m  paM  of 
ha  cnonnl  *Tnid  tik'   ~ 
'  iiqilaiaU 

la  •enir*.  _.   _     _ 

-ok  (ban  n  irorb  IhM  la  d^Vni'i!  atoliMiMf  n 

'  ifoatlnf  rm^mraa  ab^  'H-    -  .-     *a-l   (»** 

qn^nUy  ooauina  IiiM   Inf.  i^  pWa  •• 

|l<iaCB,taF  Uia  nianw*ai>'i        i   .  .      .  •oitrana* 
(hfti  b  liktiy  to  baakai  mu.    U   wah  MbM 


Tliaooiinttyl*  <UI*i*lth  nUlrwInMMi.^ . 

ivnaa  wliatv  aotliUat*  uv  Ci^tiuilty  aaMin* 
nnd  towhlck  innanl  prb  ,  i>ad  iw  * 

llnnUMd  lurMti.  ate  .  ilaUi  all 

ourwl     W«  aSdWItr  (.'  -  ..n  i 

•kcvid  t«  la  UM  Uhnrr  -I  fK'ry  j.nat 
OwwaMtl  JMlait  JltH,  P^Wunr/,  foL 


BTIM80N,  LEWIS  A.,  B.  A.,  M.  D., 

PkM/Iy  of  Uvr.  ^  ai»  qT  .Y.   r.,  CbrropowCiu  jTonter  qT  !<•  Aoala  dt  Cturmr^M  t'^ 

A  Uanool  of  Operativo  Burgory.    ^ew  (Komil)  editkm.     In  ooa  *«7  hi^ 
MiiM  mral  ISiDO.  T«luBia  or  ACS  p«)(«n,  with  342  iltiiatnliotift,    ClMh,  $S.AO. 


Thnra  ii  nhw*  raom  tat  ■  ipxid  botk,  to  thai 
*h<la  Maa*  ir«rk«  on  ppmita  •urvry  maal  W 
oouliUrM  (uwraunDi,  (hat  nr  lir.  IMn»on  hai 
Mil  li»n«n.  TliB  aiiilibc  kno«i  Ida  dllD^ult  an 
•t  oon^mMlfoD.  Thiu  Uia  manual  Mrna  ■■  a 
w«rtl  cC  ntfannia.  and  at  Iha  ••ma  Uma  w  a 
hnndy  auiJa.  II  iraEhnt  iihal  U  firaCuMa,  Iha 
•Up*  nr  a|<>nitlaniL  In  thia  vdltion  Dr.  NJmMn 
bMaovihiiO  l»JltaM  the  chauit«  lla(  bnvabann 

By  the  eamo  Author, 
ATreaUM  on  Fraoturos  and  Dislocatiooa.    InlwoluuulaanMMUNMt 
iMiM».    Vol.  I,  FKAI.-TUIIIS,  •'JH3  |KiK««.  3eil  baaiitifiil  illiwtnili>nu.     Vol.   II.,  Paucv 
nov^  uo  page*,  Willi  103  illiutditiuiu.     (^loplMe  work,  cloth,  $5.50  i   IcaLbar,  (T. 
Either  Yoiilinp  t«| 


ennoud  Id  (warellT*  tnathode  asd  mxitiiam  It 

SaMUlMpUe  aral'nl.anil  ha>  >dilt>d  aa  im^b 
mas*  n»ir  OHtMliMia  and  tulatlaaa  M  at 
tupa  sf  olitM  DpanllonaL  Wa  do  »->i  4a>»>a 
aiiAl  Uii*  maoaalalMva  niaojr  atfiaXoni  iiialpi 
KriUtti  publleMloUB  ol  iha  nama  nlaa^  •lUl  aaiv 
llairo  UiH  II  annialna  muoh  lliat  t*  mttnia  ri  ■» 
lallno.— JlrtluA  JfarAMrJowiMT,  J^  (^  OR. 


tponlolr,  cinili.  $3.()U ;   Irailivr.  HOO. 
fUieaaoond  ntema  muki  lb«    ol  DlBknMloo*  •<  It 


Tha  appanmneaoi 
eemnlatlon  otthaanthor'aonEloiil  plan  '-f  iiniar 
tnK  ■  *nrii  ablck  aliiMld  praaani  tn  Iba  niftfal 
Gunaar  all  Ihni  It  knoirii  on  tba  otvnate  ■ut^acti 
nt  Fraiiuiiaa  and  PltloraltoB*.  The  teluma  on 
Tnetana  aaaumad  al  ooca  Iha  poaltlon  of  nii  ihortlr 
«n  Iba  lUtijM*.  aad  lia  (MnpanloD  on  Diilooailant 
vltl  oodonMba  alnllarty  faeel>*il.  Tha  cliaInK 
TOlunio  ot  l>r.  Stlni*nn'a  work  ixhihlU  IS^aurxBry 


la  taiiaht  an 
moataanlnant  anrKasiUaorUia  praoaait  tii 
lalolnalhararallaoCauoh  *>i*aila)l  rw 
iniiai  lor  •  long  tlma  be  T*Bar<lad  ■•  a»  — 

on  all  aulilecia  pMMlnlSf  la  dlalo^hiaa. 

)iracilltlanararwrc*g7  vlll   IWI  U  lananhHI* 
lilm  to  hat*  II  for  wnalart  rvfaroaaa. 
ifalical  .V«H,  Mar,  Ml. 


nCK,  T.  PlCKERIJJO»  y.  K.  C.  S.» 

Jl«aoalo««*U*l«'«o*iS«vn.«*E«-a«i.i<.ll'3f>»»»,U— -.  ' 


I 


LxA  Bkotbreb 


BURIiTETT,  CHARLBS  H.,  A,  M,,  M.  D., 

Tbo  Ear,  lU  Anatomy,  Physiology  and  DUunaas.  A  PnctioLl  TrastiM 
Air  111*  "<•  fil  Mnlinl  i^tiiiivnw  und  I'miliiiuarn.  Sorotiil  tdillon.  In  one  hamlwDtiie 
«tUTi}  Titl<uu«  uf  6H0  pHg«,  witli  lOT  lUiWtratkiiM.  CloUi.HDO;  UotliM, l&JXL 

WanoUiTltlipliiuursihfiippMnaM*^  aHenod  e>rrl*d  out.  and  fnii(4i  a**  mailar  iMtA.    Dt. 

•dIUM)  of  (hu  T«lii*bla  woik,    Wh*n  H  dnt  eMna  Baroxi'i  aaiH  must  Iw  t*ur4M  ■■  k  vny  nlOB- 

•U  n  «M  MotpMd  by  iba  f«ii|itMi)an  *■  ona  uf  Ma  «at(IbuUc«  id  aunTnircT,  SM  miy  oa 

ik*  MHiduil  vDik*  OB  fn«lam  aiinl  lursarT  In  ascvnnt  of  lt>  fomprat— »lTi< »—.  inn  >«rain«  H 

tt*  Kagnilt  lancnuni  Mil  la  hit  Hvood  triltlnn  MoMua  Uis  mnli*  oT  Uia (araAil  panonal  obiai M- 

Dt.  Bimaii  lua  ftillT  maloBaliiad  hia  rapulaUan,  tlon  and  a>*«rlan(*or)>il>*inlB*BluinlaDni*ab 

Jar  Um  beak  I*  taplau  alih  nliulOa  lohumalioo  —LvidM  lamal,  Fak.  n,  IHft. 
•M4  •oaBHCloiu.    Tba  raiWIaa  ha*  b«*D  cvarnM* 


BBBBT,  GEOB6B  A.,  MI.  B.,  f.  R.  C.  B,,  JSd., 

Dlaeaaea  of  the  Bye.  A  PtmiImI  TtmiIm  fnr  Siuilvnu  of  oplitlialaioJonj.  In 
one  octaTo  Toluine  of  483  pages  *i>b  144  Uliuintioiii^  U  of  which  are  ImutlfUllj 
cotond.    aotli.  |T^0. 

Thia  navaal  ooadlduM  tar  ttmt  wnaBC  apnthal' 
Balo^ralaiiidanldaitnilgBadloMparatirollairal 
In  oiiaiavlar  kiid  <ha  plan  Usall  adkand  to,    Wa 


k»»Maa  toMltily  (Uack  by  tl.e  rut  loal  Uaia 
tn  lb*  MlMtiaa  or  ulial  !•  aueniw  whleh  pai^ 
■Maa  Iha  book-  Tha  aiilhor  taana  lo  iiaTo  tha 
■Doammon  IWcultjr  of  *lnln|  hia  miHan  m  • 
whole  aad  lalilDR  tha  wliaDi  polDUaBd  noloini- 
ni>lD|  hit  rvadur— preiuniably  a  Bludaul  aoil  ■ 


nodco— «l(h  a  man  of  daUJi*  irll^  no  kty  l<>  Uioli 
iirinit«rilnc,  Li  I"  HpparaDl  f  hat  lb«  Ultratiu*  af 
••ch  ■ubJoK  hai  hna  (nno  onr  tn  ■  tan  iImt- 
odO  naanar-  Tlis  tet  itiai  ha  na  ariMM  • 
Olstnii  iniillin  tm  (ipgiiiiian  and  oot  an  aaiTalO- 
H>dte  hM  ahnji  b««a  piaaoDi  alih  iha  •Dllior. 
Tha  namtar  and  alo»llanc*ar  thaoolorad  llto*- 
inilona  In  Uia  i«i*  doaarto  mora  than  a  paMlw 
ooUo*.— ilnkina  af  OrUMmvlatt.  B*pk  1M». 


NBTTLE8HIP,  EDWABBf  F.  R,  C.  S., 

QpUMMf  AifW"  a(  A.  TteMi-  Uotptftl,  Lmdim.    Surfam  10 14«  JlDiral  totdm  (JTooqleMa 
OrUtalia<fV>M}nML 

IHaeaaea  of  tho  KyO.  New  (foiinh)  Americ«n  fium  the  nrth  F.ngliih  cdilicu, 
thoroiurfitjr  revisoJ.  Willi  »  Hi]|>|>l«tii«Dl  on  lh«  Ivtm-tion  of  VajIot  BHtidiMM,  hj  Wa<- 
LUM  THOXiiOlc,  M.  !>,,  fnirnoKC  t,f  OjihthilitioUf^  in  iLe  Jefleraoii  Mmlical  <JuU«^ 
In  tmv  ISino.  Tolumvur  oOU  iioroi,  vith  161  i1lii>lralkai>,  Mlection*  from  Snellen'*  icrt- 
ITpas  Bod  fanDolBi^  uid  a  colored  plaW.    Clotli,  f2.0U. 


Thit  la  a  *«lt-kaowa  and  a  raluibla  varlc  ti 
vaa  prliiiarfl)>  iataodod  for  Ilia  u>*  <if  •lodanu, 
aad  *«ppll*»  i^Hr  naadii  admlnbly.  bui  It  if  a« 
••alWI  inr  tha  prarlltlODar.  or  IDdMd  oion  to.  li 
Maa  aot  pmuapua  itae  larRt  wiiaaui«f  ncondlla 
ksoirtodi*  10  ba  pKMnl  which  Mom*  u>  ba  aa- 
mmmd  tn  mm*  of  our  Inrcar  workiv  u  sot  Udlou* 
(ram  vrar-<<oo«la«n*nv  and  yst  eorara  iho  mora 


Impartant  patt*  ef  eltnlcal  oi'lithalBolofj.  A 
■applamaol  I*  madotolho  prasont  adltlonoo  tbo 
prwtlcal  xiunlnaiinn  vt  nlltttA  acaplo)^  ai  Is 
«alor-bJ1ad»t^aod  aoQi«no«a4^r  Tlilian  and  heof^ 
lag.  ThIa  l>  ••■>  ■illlan,  and  oeatalaa  feod 
*"n«*loni  br  ihOH  irho  uf  b«  culled  ■■  " 
maMo  (ooh  •ualnaUooa.—Jnv 
Awaal,  IMMUber  )*,  IMO. 


r*rk    MMmt 


JT7LBR,  HENRY  E>,  F.  R.  C  &, 

A  Handbook  of  Opbthahnlo  Soieaoe  and  PraeUoo.  Handtuma  »to.  ml- 
uiuror460t«igea^wii)i  IZ^  voedoiUy  117  cokircd  plnM,  Ml«ctuiiu  fiau  TeM-irpo*  of 
JM^r  and  Bn*Uni,  and  IIutmgrMi's  Oolo^bliiidiMM  TtM.     Clotli,  fiM ;  Uatlicr,  f^M. 

II  pnMOM  l«  Ika  atiidont  ooDOla*  daatrlptlniu 
•o-l  i/[>L»l  lUuMntloM  o[  all  UnpottoOlofwtflM- 
Uoo^  iteeod  In  JoiieinaltlOD.  aa  ai  la  ba  RrMiitd 
M  ■  aUnea.  nayuail  a  doiibi  ii  !•  iha  boat  lime- 
irlat  haadtook  of  Dj-ltthalmlc  •clBiii->«i,lohbaa 
•T*r  appeared.    Tlwo.mxt  U  illli  Uiler,  ihree 


llluWtaih>n*ar«nearl]F>llorlatnaI.  IV"  h«»*  ««• 
BMlacd  IhUaMJta  wvlk  >M  (Kal  tarr,  and  It 
nproMhla  Iho  mmnoolj  aeea|iicd  ilaaa  <4  a4' 
na^Hl  ophthalmolMlite.     We  ean  tnoai  haartlljr 

UUoMni 


PH««     *9tW     Infill  UfMUl/     ■■^£V|<1VU      IJOW*     Vfl      HV 

:  ophthalmolMlite.  We  ean  fno«  heartily 
ad  Ihla  book  fo  all  madloal  Modanbt.  pna- 
n  and  eiwdallaM.— Oaiirofl  t/mnt,  Jan.  It. 


yORRIS,  WSt.  r^  M.  />.,  and 

A  Text<Book  of  Opbtbolmology. 

Wllb  UltHlratMHH,    Pitformg, 


OLTFEBt  CHAS.  A.,  M.  D. 

In  OM  ocuto  volnna  ef  almui  500  pagi^ 


CARTER,  R.  BRVnEXELT^ 

.F.  K.  r. 

'  Smrfay  «r  SI.  CoriH*!  Whj"  ' 

Ophth^mlo  Surgery.    I«     ^ 
ooloT-lillndneHi  t«t,  tnt-lviia  nu'!  <  ' 
Strim  t(  Clmitml  Mtmmai;  page  31. 


&  FROST,  W.ADAMSy 
H.,  F.  R,  C.  «., 

Jh"!  QfUkalmt  Strt—K  ami  Jaitil  UiL 
oa  OpV  Sv .  Si.  Oml^'t  Hop.,  t*A«M. 

viliima  of  fiSft  ptvai,*<('>  f*'  "•'oduili^ 
1  |..'i,ilic  of  fanmOa.     Cloili,  1225.    Sm 


VRLLSDXTHKBVK.    Id  one  oouto  nlome. 

LIUUNOI  ADD  HOOK'S  IIA»UT  IWOK  OF 
UPBTBAUtlC  BUaaSRT.  for  Iha  aaeof  fnc- 
UUaaera.  Hoeoad  edlUoi.  Is  oso  oolato  nl- 
ona  at  m  fiase*.  «nh  M  lllua.    t^oth.ttH. 


I.aU-|IO!(  on  IXJUKIU  to  TBK  ET^ ORBIT 

AMI  BTKUIm'  Tbetr  Immadtdaaod  laneM 
BBacta.  Ia<iaa<ielai«mlaa»*e(«Hp«v»a,w)th 
M  IllwIfWi-aa.    Oath,  KM. 


i^. 


J 


ROBERTS.  SIR  WtLUAMf  Jtf.  D., 

A  PrftotioBl  TrstttiM  od  Urlaair  a&d  Booal  DlsaAses,  inoLtuliiu  IT» 

any  Deposita-    Foiinb  AmciiaiB  Adbi  tb«  routtfa  Lnndoa  ciliti'in.     In  tnauai- 
Moi*  ocUvu  rolunM  ot  OM  IMfM.  with  81  itltiMntloni.    CInlli,  tS..'-'< 


IlinBybaiald*Ob«<h*fc*ttlM>»k  laprlninslha 
•UtM«>  of  «)ilDh  tl  W«M&— n>  JHV4«H./*flrnal 
if  bU  M«iU»>' Sctfuo,  iiL  UM. 

TbB  iraonlkf  TkliMsnil  tiiUik  <f  (ha  book  at*  Im 
■  mawMr*  ttTt*t4  trom  H*  nMliiW  malBtanuK* 
nf  •<tiaiult*4i>rwUc>lahHV*ar.  Itk  ta  un- 
rinllM  •luMdlMs  o(  arviTthinR  which  riMn 
AtatUy  or  iDdlMMlv  •»  th«  dI>c■l«<^  l««(o«l« 
tad  iwlnwu  «C  umtf  iliMili^  ■nJ  pmmhm 


mm*lal«a*»ii  ttol  fn 
voMi-  IB  lU  a««Miiil  i-l 


•!•  >a  orr  Mr 
nt  tlliiwi 

>f  JfiHftaif*' JfaUni  <  1<U 

TiM  **l»a  of  ihti  irv..  —(Li  at 

phn4(kao   ia  ^tity  poi'  i*  '^v 

•attntlfil.  Thcl  U  U  I~..,  -r  — -..  .siMllM 
pr*MBl  ka«ltdc*l*kfHitn««M;iiB«ra«aMi 
upon  Dr.  Robam,  «h«  hiM  a  irMa  npUMMsBt 

ini*r  pf»uii««*r.-ir«tw>t  AMe>4<>Mra.t» 


S7  the  Samo  Author. 
Diot  and  Clgeatlon.    IncmelSno.  volauMofSTOpp.  C1otli,91^.    Imim^ 

PVRVr,   CaARLF.8  IF.,  jif.  i>.,  Chicago. 

Brtgbt'a  DisoftBo  and  Alllod  AfToottoiu  of  tbe  Kidneys.    In  oo*  «■> 
niliitu«  ul  U8S  lugtM,  nilli  illminiliuiB.    ^.I'-lli,  |^ 

The  aAlant  nt  IM>  ««ck  UtP'tUrnlih  >*)r>tw<  '  (hon  ■■■«•  (ha  UimMc^  IhoW  ui4  ir« ■!■■««»■< 
MM,  aneilal'aDd  omwIm  dMorlpIlM)  «f  Hie  letOR  mats  ftiHr  UUa  ttair  ■■i-.r  ■ranb^HUi 
nUJMMST  and  truatmaul  of  Ui*  <t>l«f  Orniale  un  irvUinaH  Uia  mIMr  ia  naninjlailt  ■»■! 
Alw— a»t<  Uw  kldbtr  MBrtataJ  wiUi  ■Ibunlou-  JiUatlac  c)*w  uf  sNitnlUIw.  mnA  mtttm  mi 
rtfc  nthlob  lAall  tr|tfwan(  (ha  moM  raofal  ad>  uai.  anal  (•x^'bgoK*  nanally  do,  tM  uaJupanM 
tMtaa  IP  ont  knowladw  <ia  (lm«  Hiitjaela  1"  and     ""  ""  " 

lUi  Moidbo  ut  Ilia  oCjoM  U  a  iib  4M«clr4U>n  of 
IM  bo^.    Tha  aotk  t>  ■  uh^iI  ««*,  Ki'^BE  '■>  a  1 


Uai.  ahal  ( 

IW«a  «hkh  ara  all  lanratlaot  (a  Uia  cmmM  (■» 

UUsaar^TM  JTawAMbr  MidUml  dtrMHH  tM 


MORRIS,  HEXRY,  M.  B.,  F.  B.  C.  S., 

Sorgloal  DlseaadB  of  the  Kldaer.     In  om  ISbw.  vo)iim«  of  664  pap^  'iA  V 
WMilcut*,  kod  6  (ulurrJ  flnUs.  Lim])  doth,  flSS.  Sm  &rlM  «<  Cltimoa/   "— rri'f.  p^  ft. 

.  .4  (fw««w«r 

l>a  KloalJSla 


la  IKIa  luauua)  ■•  hara  a  dMteM  mlOMta  M 
•uixtial  ilWnlUTa.  ahloli  RlTa*  laforfnalloa  aM 
vlMmharaWbamaiaHh  In  a  alalia  vork.  flueh 
■  took  ■»  dl-lln«(l]r  rHulr*d,>a4  Mr.  tUitU 
hat  rtrj  tlllcanlljr  m4  MSt  fartMOMd  th*  la)k 


h«  (oak  la  taa4.     Ii 
bcniKf  rvtwanoa,  U4 


IMoaafa  la  Harioh  of  ■"  1 

■•(iMMitand  UMflhrom'j-iiDt'-crarli*  anki__ 


Dm 


^ 


LVCAS,  CLEMENT,  M.  B.,  B.  8.,  E.  R.  C.  8., 

S«Mr^Mi*laa(K>vfini  la  ihmft  thtpiml,  lo'^t^ 

DlaoBMM  of  tbo  UrMhrft.     la  en*  lano.  roiuaw.     Prtparit^. 
tf  CViiMnJ  Xmvoit,  jmg*  4.      

TBOMESOy,  SIB  HESBT, 

LeotuTM  on  DiMUoa  of  the  uiinvr  vrgmns.    Baeood  Amerieaa  froM  iIm 
tUnl  EokUMi  adiikiu.    In  on*  Sto.  toIium  of  4Kt  pp.,  «iih  S&  UlHamUov.    CloUi,  yttt 

B7  the  Same  Author. 
On  the  Fatholoff;  and  Treatment  of  Stricture  of  the  Urethim  ud 
ITrinary  PiatuUo.    From  tha  Uiinl  EuliiJi  ediuon.    In  ooa  ocIbvq  Toloaa  «f  W 
ptgw,  wilh  47  «iu  and  3  platM.    Clixli,  $3.40. 

THE  AMERTCAX  SYSTEM  OF  DEXTISTRT. 

In  Troutisca  by  Various  Authors.  IJIiinl  hj  Wn.Drit  r.  I.rmi,  M.  D. 
D.  l>.  S^  Pntrntur  of  l*ranh«tlc  beotiMn,  M&teri*  HwUa  uil  Tb«nipmtl«  ia  lfc« 
l^niu^lfUkLa  ODtl«g«  of  DmIaI  Burgerr.  In  three  t«I7  IuumImjm  dcUto  tuluBa  o* 
laiDlnK  S10U  me*,  with  I8SS  illiiMntilotii  anil  9  liill.paitB  plawa.  Par  roliima,  ek«h,  K; 
lealbtr,  ITj  half  Uorooco,  gilt  Utp,  Pi.  Tbe  «xiiu|JcU)  wiwli  !■  mib  r«aify.  AraMtly 
M&Mn'jnIiMi  a<Jy. 
Aian  auPjvloMilJa  of  ItantlXiT  II  bM  no  hi.  ;.teuMaul*M,lu  niark  nn  opAr*  la  liw  bkMT  44 
nrlut.     U  •hoiir.t  t:rm  a  pan  of  nary  danUal'*    At^OMtr.    LwMtMi  alll  i*  ratUOmt  mU  M  m 

■•4  of  tl— 4h«*  mnii.  1(  U  iar«  to  ba  iiiulufT 
n)  naada  to  noi  ttlm  aM  lit^  hH 
ick,  Bhlla  M*  arbfrMloa  ai  toaa 


Hrlut.    U 

llbraiy.  a*  Ui*  InlorlnaUM  II  untatD*  It  of  Uia 
craataal  ralua  I*  all  auM»d  In  Uia  pcaallM  at 
&aUui7^.1>"^Ma  JowTDwiL  jSH.,  Sapl.  IMl 

A  Cand  MMMn.  bif  anough  aB4  fsod  aMoch 
■nl  i.ts4tM»*  anaugh  (or  a  monilBianl  (vklrh 


■aM»n*l  Mill  I 
pr«<*4i 

•hat  (te  oludanl 

la  lb*  ii|b(  mck,  ahlla  nia  arbfrMloa  ai  toaa 
•ill  r-<^*a  iMakuUMa  baaaM  Awa  IL  Otpfc 
givplK  Jjw  Mi;  Jan.  Un. 


COi'fiUiAJr^  ^.,  L.  R.  C.  P.t  E.  R.  C.  S.,  Eaoam.  £.  J>.  &, 

S-tar  ttml.  Am.  and  X4M.  «■  Btnl.  Avg.  n4  %  XarUotaMiri  JTsf^  and  !*•  ItoX.  Jbtf,  ^.rfn 

A  MkDual  of  Dental  Surgery  and  Pathology.  Thnmi^ilj  nrlatA  aal 
adMited  10  ih«  lue  of  AuwrKaa  Stiukau,  bj  TuoxM  cTttnLLvriOKM,  U.  A.,  M.  Ii, 
D.D.a,Pn<f.ar  PlijualoKrinllMPIilhaaiphlaDvftUlCbllM*.  latn*  kauboMoeun 
ToluDw  ot  41s  pam.  allb  381  UliaOntlona.    CIoUi,  tSJSS. 

II  ibAiiM  **  (a  IM  p«na»taa  ol  ararr  intU-    a  «*n.    II  lb*  nionB*  fM  Imo  aona  n(  iv  * 
tM**f  In  Ihb  CMtnUT.    Tfca  nan  *»toie4  la Brai       -  •  ■^...- 

and  tacoB'l  danilil-n  and  IrrticnlanUM  Ip  iha  par. 
nanaai  totih  I*  IWIl;  *ortb  ia>  prlOK  ta  mi, 
prlr«*bouUnMt«ct«tldKa4\avaRV«ataiavu« 


_j  n(iw  I 

•MM  uandM^  IMV4>aaka(!Milil  baoaMfMU 
aatb  paMli'Mlaaa  a*  1*1*,  mnah  a«*d  vunU  nadl 
-SHUin  /iv^al  Jht-A,  Har.lMa. 


Gul<l«  10  tfi*l*  lAacnoMa  aafl  tn^mtiM.  \«  \  «■»..»». 


SA  BaOTREBS  Jt  Co.'8 


6BOSS,  SAMUEL  W.»  A.  M.,  M.  7>.,X£.  2>.; 

P'ofaiv'  ttfim'niiMm^aarttr^iu^itf  OuttnUlK^r^  ••>  (A>  ^xfirwi  ««iui*(  CbUtf*  *f  rute. 

A  Prsctloal  Treatise  oo  Impotenco,  8t«rilitT,  sod  Allied  XHeorden 
of  the  Halo  Sexual  OrguiB.    >r»  ruii)  tidUkiii,  uioiauebW  revbtd  bt  K.  R. 
&mtoi«.  M.  1*.,  I'lof.  uC  DivoKaof  lh<  licuiwUrlmiy  (hs>ca  mm  M  Venereal  Dii 
H.  Y.  rt«i  Gra.1.   Med.  ScbooL    In  oop  ver;  huxlnaie  ocuvo  voIium  cf  ]<&  (ofli^ 
with  laiUiwiniMiix.    C3Mh,tl30. 


Tbn*  •AUtanBor  \'mtntor<iKit»'  nltakitUiak 
hsi*  Mao  vihkuiiwl.  lUd  ■UII  tba  daOMCxJ  ■• 
DBaiipptltd.  Ifr.  SiiirKlii  fc*>  (VTlcvd  and  addwl 
to  Ida  r<*<^n>*  *<'>*Mn^  and  Iho  aavanaappam 
Eaat«  complaw  and  men  nloabla  than  btltonL 
Faa>  lmr«fMMBud|iaaar*liyml>UD4M*ioo<l>uii- 
JacU  ar*  tnai'd— iiniMlaaM,  Marlllly,  ■pamauir- 
ftuaa,  aad  pmtulnrrniaa.  Tha  (sok  I*  a  nnmli'il 
ona  and  in  adiUiian  m  iha  •alaouflo  anii  lary  In- 
MraMIn^  dtMiualnDaonalMogT.tTnipianiihale . 
than  ara  llD*a  ef  (Naunant  laid  duau  itiat  any 
fTa«(UI«i*r  na  fallaw  and  whlvh  tiaia  mal  vlui 
niMfaa  la  lit*  hand*  of  aulDor  and  adilor,— Jftdi- 
crt  JtMvnf,  Fab.  IM»] , 

IthaiMMi  tha  aim  el  Uia  aulhor  lampplj  to  n 
«oni|iaa<  fnrm,  pra^llral  ami  ■irlc*(ljr  krivaita-j 
l&ibnnatlonr*p«ola[lj  hdnikitiii  (n  ih*  wanunf  1^4 
^AalVl  pfMlllwnar  la  r«iCBftlioaclap<4orroniDi4>n 


aad  (Tnt*  •llorim  T^*  mrk  co>lnJ»<  ftwf 
mtaj  (uru  In  n(»td  la  IW  HXaaJ  dtHTdm  «( 
naai,  «f  iiia  iiiml  ioWr*>lia|[  ghancut.  Wa  nun- 
masd  iha  ttttif  of  It  la  tnij  f*o(H*lonal  man, 
and  aaixalallr  u  thoaa  •uivDd  lo  lha  (M*ral 
pnetloBot  niadl«ID«^CIa.3M.  JTMn.  Jan.  IM1. 

Tha  oark  brfura  ua  ha>  Ixeenia  a  rtandnrd  Uil> 
Irsok  on  lha  ^ul^^cra  ot  vrhlcli  H  traaiL  In  lija 
t>rFMi>l  adliiqii  ih*  aiiiliot'a  vorh  hia  M«D«tQ' 
■Idanbljr  auKmanlal  by  tx.  Starfla,  wliciaama- 
IrthuUun*  and  Tlnn  ar«  Is  ba  taan  •taiyaltfra. 
Thay  contain  Rianj'  nioaMa  annt^Ulan*  maa  ara 
Ih*  fnill  n(  a  rip*  aipaftoiaa  irklnh  aaDMil  IxK 
pnhanca  lha  OFlKinal  MiL  Tlia  i-ntpvlnn  ti 
uulck  10  appraoiMa  tueelnel  irtalk*M  ohlrh  an 
rtill  vi<1  eompltta,  aora  aapaaiatly  wban  tba 
4>iiiiinr>  ai*  kaoTD  lo  ba  •ronh*  ot  ratpaM  hi« 
wnnjonof.-^  l«alaJf«landAr-J«''.F«b.>l, 


N 


TAYLOn,  R.  W.f  A.  M.,  Jf.  />., 

JViff.  ^  Vtinnal  and  An  Oitauii  tn  r*t  (Mii'i'iitu  n/  rnwal. 

The  Psthologjr  and  Treatmant  of  Venereal  DUeaaea.  Indmllng  i)i« 
NMjl(««r  Ncont  iflTcatigatioiw  upoo  th«  xilijcct.  Itrio^  Uiv  uxih  edtUan  of  BunuMad 
and  l^lor.  Entirclf  r^wrillfn  by  Pr.  TojIot.  Ijuhp  Stq.  Toliini^  thtmt  800  MM^ 
wtLhkMullSOenKnTiiigii,  shwvII  m  iiuini-r»i8  <'lir<im»'lill)ugni|ilu.  /n  ocliR' pnpapalt«it, 
A  ooiioe  iif  lh«  iirerioiu  edition  is  n|>))ciirJ»J. 
II  (a  ■  aplaodld  racord  o(  liooait  tabor,  hm*  uipod  lha  mbjacu  nf  wLleh  II  (raata.  Inl  alto  aba 
ruaanh,  fual  eomparliun,  nnfiil  •rruitn)'  and  1  nMcd  hu  neaqual  Id  otliirun^aa  Itar  Iti  «Mar, 
«TlalDal  *tHrlani!*,«hlah  Hill  al'ay  I*  h>lil  a<  I  i-ompiahauilta  and  cnnural  k«iidll»  or  lla 
•  hiKberMllloAiiianMinnieillul  lllrntiira  TM-  inrm".— dni.  Jour,  if  (*<  Jfaf.  IM*w«i.  MB.  UM. 
la  Dol  only  tha  ben  vork  Lu  tho  Eu«llkh  iBD^u^ct  I 

CULVER,  E.  M..  31.1>..  and  JIAYDE\.  J.  R..  M.  D. 

HdnAnlMn  BoijUtal,  X  f, 

A  Uanual  of  Veoereal  DiseaAes.  In  one  13ina.T«luaia<ir>baat  £50i«gai, 
with  illittlniiii>u>.     It"3iiii  ih'-rr!ii, 

CORXIL^  r.,  "      " 

/V^B.or  III  Ib>  >Vul(u  uTiTaMM  s/ JWt.^  a-f  fkw^naa  to  (^  I«>«<a<  itdvaial. 

Syphilid,  it«  Horbld  Atiotom;,  DlagnoBia  and  Treatment.  R])«dBl1r 
nTiMd  V  ilic  Aiitlior.  nii<l  lnin-Iiii<^<  villi  iimim.  and  addlilaiM  Iit  J.  Hkmrv  C.  Siusi, 
U.  D.,  DpDKiiulralni  or  I'alhuk'Kit.'nl  Ili'Inki^-T  in  lli«  Unit,  of  IV,  knd  J.  W1I.I.UN 
WBtTC,  M.  t>,  Lociuror  on  Veiirr«il  I>iic«6c«,  I'niT.  of  Pa.  lo  one  fautdMBDe  ocuvo 
voliimr  of  Ml  vagtK,  wJtli  S4  T«rr  l>«iiull(<il  lll<iHn>ii<MUi    CUdli.  9374. 

Tha  aoaunx,  lha  hlitnlofT,  Ih*  rainolntr  and  ,  paniial  wllhoul  tba  iMltng  UmI  hi*  nap  *t  Ika 
Ut*  pllnlnaJ  Ifatam  «t  (jrphllla  ara  rppr*HnW4  In  I  wUa  and  Important  aiibjairt  f«  whtph  H  irMt*  I* 
•bit  work  In  ihalr  twtt,  moM  praeUtsI  and  mol  a  (tronicei  and  lumr  on*.— 7>a  JDaaioa  iVain. 
lOMMcUia  turui.  ui  J  uo  oaa  will  rlM  flrom  lla  i  IHwr,  Jim.  lUX 


CKkf  nf  Oiaif   ■''nfrMl  linrntmrnt,  Haa- 


aoih. 


HVTCniysOKf  JOKATHAy,  F.  JJ.  S.,  F.  R.  C.  A, 

Qv*««-rfi'«j  Hu'^tnn  to  rhc  Lomlcn  Hotjiital. 

BTpbllla.     In  imp  ISmo.  voluiiip  uf  ^Ai  [Higea,  with  S  diromcr-lilliognptii. 
$3.36.    lit*  Stria  of  ainital  Man<atU,ygtA\. 

ThotawIiD  ban  aaan  mut  af  lb*  dUaan  and  '  an.!  ynintBl  ohaarHtlen.  bulef  hb  patianMaad 
IboM  nha  hBH  fall  Ih*  raal  4Moulll>tor  dli^niv  ■"•dTiliy  Jii  uhlan  »>*-•*  el  bla  «•<■■  aad  haap- 
■!•  aod  malni-ni  «ll)  moat  bl|hlT  appraclua  Ibe  ,  li>(  <h*m  ID  a  (<«m  amlahla  (or  >ueh  aKMllaDl 
fK-i<  asd  ■i>i|i[f-'ti'<Di  ahlch  abonnd  lu  ihua  iixia' ha  haa  put  IMmlninlhli*alaB«.— Iwndm 
fnifa.  Ii  la  ■  ■'inliy  and  Taluahia  tacotd,  not  1  JliAai  Aieard.ilM.ll:  HVI. 
onl^  of  >l^.  Hui4'hiLx*on'«  Tary  Urfa  aaparianga  i ^^ 

GROSS,  S.  />.»  X.  D.,  LL.  Z>.,  D.  C.  L.,  etc. 

A  Practical  Trontiso  on  the  Diseaaett.  Injurtoa  and  Halformations 
of  the  Vrinaij  Bladder,  tbe  Prostate  Gland  and  Iho  Urethra.  Tliinl 
edilion,  (fanroughfj  revianl  bj  Hami*CI.  W,  Uro«i,  M.  L>.  In  oai  octavo  tulnina  of  6'i 
|«g«a,  with  170  illiiamiiiorni.    CVdli.  iiJM. 

CULLBRIER,  A.,  A  BVMSTEAD.  F.  J.,  Jf.O.,  LL.D„ 

Jhrawif-IM  AtpU^du  JMi  Lf,up'«f,,-f  IW  0U.  CUL  Mm   nadAvf.X  T. 

An  Atlaa  of  Venoreal  Dleeaaea.    TmiHaMd  aad  aditad  by  faBuiAii  J.  Bum- 

m-EAD.M.Ii.  laeaaiii4MriBl  4(i>.  *oluiiwom8pagai,ilniiU»«oluinn^wltli  36  plxe^ 
onnUioioK  about  IM  flfarai^  baasllAiUT  aolamd,  ananj  of  them  the  aiae  of  life.  Strongly 
bound  inclotJi,|17.00.    A  ipaduasof  tliaplataaam)  Icitaam  b7  mail,  <inrai;<alpletfSScU. 

H"!kPJH?"l"»*'">''P<'*'-^«*T»oior«; FORMS ~or  LOCAL  pisRjsK  kmxmw 

i-BM  UWrUKSaOir  SrPBlUS15D  SOMe.TluS.    1aoo««ioiol-ot-M«acik   OMav.«Jk 


.*8  POBLWATKW*— VMM 


TAYLOR,  ROBERT  W„  A.M.,  M.I*., 

^rwan  IV  |«<  /lafHrlau^  «/  r*i*>m(  Md  Wi*  Uubmi  i/  ikt  Aiw  fart  V«*aM; 

A  CUnloal  Atlas  of  Veaereal  «iid  8kln  DkMMU:  Indudbig 
Procwaui  nml  Tnuliumit.  In  cigbt  Urg«  lolio  pwti,  BicaMiriiii[  H  X  18  IndM, 
eonafKtinx  ^  ixnaufuUj  nilorod  jilnta  wllh  S13  &(iiT«k  *»)  431  pagM  ol  uxt  «ttb  I 
CBgnvii>g&  Coinplvt*  H«ik  jW  rwu/y  Prio«  per  put,  fSJHX  Bwnd  in  one  tnloM*, 
half  Hiusik,  |£7  ;  lialf  Ttirkej  Murocoo,  f£4  Fvr  Wt  iy  «it6wT»i<ti>ii  n/y.  ^p«ciai« 
pbU»  Moa  on  receipt  of  ID  cent*.     A  full  prwnKlm  Mnt  to  my  addrw*  on  ap|'lloi(K«L 

TbceoniiMIaB  of  thU  naaanioaul  vorh  l>  >  dMM  (o  •  noUes  K  Uili  hlM.  U'l  •'.il*  «a 
■ahMtcf  asiuTUBlMlaD  dm  odIj  (o  Ih*  aiiUot  b*n  BMIitu  but  h*Im  titr  Mis  k4u>lnlUa  alli^ 
■of  paUUIikn,  bnl  lo  Ih*  pn<r<M*IOD  u  lug*;  llttiu(b*adil  la>*Mn(aUan  ihain  toMmUiM 
ladvMltlf  MUisUUcrlhx  ItdlNoUyitiMiila  M  vkmaifd  by  ili*  nwrlti  o>  tk*  wark  ~ 
k  wDoittrfallr  eleor  •iikxHIod  of  ■  nntwMily  nttfirftnl  .V««t,  Dw  14.  IHa. 
dinnilt  linnch  d(  nidlEio*     Good  lltaraMra  ha*        tl  woul-lli*  larillu  uh  KunUaiilf*'  annld  | 

Klnari  h*nil>  vnli  nod  ait  ■Itli  hIaUjr  Mttuho-  (rlmioualy  aoAUCb  mutst  lo  <ba  i*«-t>i  Ui*  antt 
r>  rwulu  for  bntb.  Than  an  dlAplhar  lU  talao  nf  llUa  C'fninl  ^iLw  Tlila  Ailw  la  i  '  - 
hturaa.nianycif  vhlcliara  life  tlMianifrtprHSDi 
IM  blulioat  Mrfntlon  «(  lAo  ohtomD'lill)^- 
Kimphtn>rl,aDdwMtaTad  th(au|bout  Ihauitua 
HiDuin«nibU  •atnrlosih  (JiiImb  pronoitlaa  o( 
Iheaa  lltiinnlloaa  an  from  lb*  aalncm^  dkd 
•ollacUau,  oiillii  od  Iho  Mbai  htbd  ilia  baat 
allaaaa  of  iha  wiirld  baa*  bran  dmn  U|»>a  fur 
■k*  meat  l^pln*]  and  niroaiaifnl  j.i'iuim  at  tha 
naajr  dlStnm  Irpa*  ot  leoeraa'  Bod  aMIn  d)* 
MMl  Va  think  m  nu  ■»  irltbaui  unduo 
•iwnnuiao UiM 111* rvprndueiliiDs  Iwih  In  oilui 
■nd  Ta  blark  and  whlM*!  itttr  »Tmn*t  litvnrlaljly 
•uv<««riil.  Tha  Icit  l>  pracilml.  Ion  at  that*- 
paDllc«J  ■UKS'*l^'iii'.  ^'1  tliu  Hlulcal  >ac«udU  of 
diaaais  ara  c]*u  and  Inclaln.  Pr.  TajlBf  U, 
habpii)-,ui*iinlCi«ntanthiirtt|'tnhDUidapaffnt*iitfr, 
and  «•  find  at  aonnuxiDpnra  thai  Ih*  lw<>  dliti- 
tODJB  k4  itit,  workuuajatt  an  e^iuU  aclanKAii  aud 
tlMnrr  merit.    Wa  haioMrtady  f««>Bdili«llinJla 


OMBV)*!*  •Tan  Ihaa  an  MiHbmjt  eiatai  •(  nlM^ 
l*i!Iuroi,  fer  In  noaaaeaUcH  av  laviAal  Mwn 
U II  al  all  |.n>baUa  IhM  aB  dF  tba  dtMwaa  hWM 
r»['na«ata<  vonld  ba  taaa.  Il  la  aiaa  mm*  aa^ 
tloaablaM  Ite  mitftU  at  aMdasU  Itaa  Mtaafr 
•a«a  Bpan  ollalcal  Ncuaraa,  Cw  »dm  at  na 
aluilanUKha  all  on  i«a»ia  aaaJa  Ui  (ba  laakn 
hall  naonM  ■•«  Iba  avb^avt  aa  wli  aa  Um  (■■■ 
tludpnlDanciamlaafhaaalnja  u»ILfb«fenipalll^ 


'Kmii'ik  Conipulo)  iha  t«>l  la  a  laMiiMr.B  k 
rnorfp  AAiUfHciory  In  BiaetQ4va  and  ftilaaaa  Itm 
h*  Koiild  t«  Ittoljp  t(-t4tn  tf  lafiacvaaraaaiili 
IndaM,  ikia  dUaa  la  latataalda  w  ■M/*» 


anj  praoUitoMr.  fat  II  ««rtt»i  ih*  *)w  '  .  _ 
■•hnfolan  Ut  Kkaka  dlaffaaala  aif  a  alTn  Mv  <( 
•klB  mulftdailno  b*  compartiil  Ilia  «a«a  •■ 
111"  piflorp  In  tha  ^Uat,  viMra  irlll  ka  mmt  Mat 
Iha  tan  nt  dlaxiwaia,|«UKil<iC]F.Md  MiMaUai 
«o  UaalaaaL—  rirtfinia  ifadtcS  Jra<KM».M«.M» 


ipii.. 


HYDE,  J.  SEVIlfS,  A.  M.,  M.  I>., 

/VitrsK-  ef  DrrmtUbin  and  Vtitv,at  JMataw)  m  Ku">  Mtditnl  CbltaBa,  Otiiitt, 

A  Pnctionl  Tre&ttse  on  DIbobbm  of  Ute  Skin.    For  lU 

Pnctilicmon.      N«w  (»cojutl)  wliiiou.     In  vat  hudMine  ocUra  Tvlnmc 

wilhSiMloml  |i1litisjUldS6licaiiufilland^abotsMllli»ir<l>(>ni.  n.iili.  t-l .' 

Wa  <an  hBtriilx  fr-rrifnt^nd  it.  not  imTy  aa  an 
litlnlnUa  UiMnok  Tnr  l>-a>:h«i  ami  nlii-lvnl,  but 

tlla  tJaarand  <4iopr«h«n*laa  rulaa  fat  dl«a»«Lla, 
•oand  and  Indapendani  doctrtoaa  tn  paiholMty, 
and  IW  mlDuit  aad  fuiHaloua  dlmUlona  lat  Ilia 
teaalaaanl  of  df'-i—  •■-  t  mosl  tail'lkaoty  and 
•Qn)Iil*Ca|ir«pl1<''  '  lifiihjrtlL'Iaa— .liaci' 

mnJlfrmiUi^th-  lihl  July,  lua. 

A  uarral  itluauai  ...-^i  i>.liiii  of  Itrnx  u  ginn. 
Tha  il»»crliillt»  i>nnnm4  at  thli  wnth  ar*  plain 
and  'ifLlf  nndvrntaoil.  and  abore  all  va  f«rv 
•ecuraiii.  Tlia  ihnrapaullcal  fiafl  li  ahandautly 
aupplled  aiih  aicallanl  raaoininnndallon*.    Tha 

eoLura  pan  I*  wall  dona,  TJ>a  Ta'Uf  ^f  Iha  laofk 
praalttianrrt  la  Erval  baciaiiaa  otUia  aaoallaniw 
af  Iha  dparrlpllona,  ilia  ■uanatftvaaaa  of  Ula 
■dflCk  and  ihaeorracluaiaurihadaiallaaad  tha 
prlnclploa  «f  Uierapanllc*  Irripratwd  npon  tha 
(•adar.— FVolaix  JVal.  VvatMK  May.  tMfc 


MMor8tud«M>an 
Inmcof  0711  pn^H 
LI  T.n  i.-.ii,r,  i&jdn 


Tlia 
r.Tlnli^al  i     '         .' 
in  dlcil'>ii.  aTiii  •ui>i'> 
TIiB  iba^tat  un  ^aaral  n-mpM'!  < 
no  olaarar  daa 
aod  OOTUMUtlra  laaloD*  •<  ■■n-  -arfi  lah 


In  It*  ■ay  : 
pilniarT  ao 

be  iiiel  vtik  laywhara. 
la  and  ihcfapauUfa  am  al*«  >on» 


Thaa*  tm  aaaatat  diana 
«  al*«  >on»]r  tt  aaaaM 
mdr-    IM.  Hr<l*  haa  abovB  hhoaal)  a  i 


hanaltaraadMof  lteliMa(HI*raUira.*nlkaa» 
oerpamtad  iDta  hla  btok  all  Iba  bcai  Kiliai  aliM 
Uia  laat  vaara  have  braucM  toiUu  Tha  ttauilr 
IlDnaaDd  fbrmtiiHtr*  )il**u  In  boib  «u«itaiwH 
matrlo  arauni*  r>il  and  tllnatrailana  af*«*S 
and  etdand  piMaa  of  far*  «aaaa  land  adiPibM 
auraMionm,  AllosHherUlaa  anxli  aiMU^aiiad 
to  Iha  na>d*o(  acananj  mttDIUtanari  •■4  aa  mm 
will  maka  a  mlalaka  tn  purchaalnB  IL— JMM^ 
Prwef  ll'aaUn  A'<*  IWtJEna.  UM  ^1 

FOX,  T.,  M.J>.,  r.R.C.r.,awlFOX,  T.C*,B,A^M*B.OJt^ 

n»*<flai>  la  («(  SaoaifaMX  riir  ^Itia  £afaaafL  l^nnnftr  Oi»aaia»rfa*<M«li«i     ^H 

(Aiirwiuv  (Wf'ja  i/aapiUI,  Zo^ba.  Kwifanoiir  WtipJit  taiMkK  ^f 

An  Bpitome  of  Skin  DiMRSM.    With  Pormuls.    For  SuiikoM  aad  n» 

Utknen.    Tliitii  ulition,  rcviMd  and  *tilait(0(l.    In  one  li;mo.r<il.uf338|i|i.  CUKfA 

Ilia  Ihlnt  edlilua  ut  Ihln  ponianlMil  handtmnU  '  ntannal  (alia upon  UiBtaUa  fcrlaaiBBi  ra*a«aa«. 

Salla(brBollMouii<i;'"i''*rt'lplooanda>|auiiilc>ti  ,  ItaBtnbatwtloal  afrangamaal  UtailaMi  MiMa*^ 

artiieli  It  haa  iimiccinne.  The  anancFmeni  nf  rkln    tot  all  one  haa  hi  koow  lalh*  aama  of  Iba  dlaaaaa^ 

loalphabtticalctfiiar.ahlch  lalbcmalhbd    aad  haia  ««  li>  daacrtpabiu  and  UiaanmpiMM 

npailoB  adnplad  la  ihla  onrk,  brruRiaa  ■  i  in>aCni<'nt  al  hand  and  taadr  ku  iBatant  aM<H» 

adranlasa  Is  tha  aludant     Th*  hsok  ta    UoD.    1'hr  pratani  adilkB  \tm  ba*B  *vr*  oarataOf 


af  elaaaUli  .      

toalUaa  adranlac*  _ 

ana  Khli^h  w*  ou  aliwiBlj  rMciDmend,  DOI  oolr 


taaCndanta  bol  alaoiopneililoDarawba  raqulra  a 
OMBpandliHia  aummari'  at  Iha   aa«aant  tUia 
iannaulon^-antut  UmUtnt . 


Sratant  •■UIMb  hm  baaa  rwrf  oar>ta>>T 
a  niimbat  tt  art  dtaaaaaa  an  d* 
Mrtbad,  *hlla  nioat  of  Iha  nnat  BdillU"aa  ta 
dwRial  ih>nr*ullca  Sad  inofiUe«i,  and  Uie  fa 


OMBpandliHia  aummari'  at  Iha   aa«aant  tUia  of, _ ^    

tarmaulon^-antut  ifadMnl  JsMwil,  JulyLIH^    laixallha  andnf  thabookhaal      _   _   _ 
WaeardWIr  m>ommand  l'oa>  Xp^awi'toUita*  lantmaiitrd.— Tbi  JfaltioJ  Aiaa.  DOMmbar, 


vhaaa  Ume  ta  llaMcd  and  whu  vUh  a  liandy  | 


id  Uie  tatma 
■DM4*fal^ 
nnbar.Hn 

m 


WJLSOy,  ERASMUS,  F.R.S,  _ 

The  Scudeat'*  Book  of  Cutaneous  Uodioino  nnd  DisoMoa  of  the  Skts. 
In  OM  huuboin*  miaU  ocUvo  votiinie  of  &35  |iae«*-    Cloth.  i-<M\ 

niLtlRR'S  lUXDdOOK  or  ftK\«  \«a6KSOM,  \  aataAWM.  Xjou^cuu.'ntanxtqt  IttHe^ 
faraadeoU  an4  I'rwlllttMWta.   MonA  VwdV  \  -Ma^i^tUm.  <>>.V.^-^ 


J 


SjMA  BuiTBnu  k  Co/fl  PuBUOATiOKa — Dis.  or  Woaicnj 


The  Arnerican  Systems  of  Gynecology  and  Obstetrics. 

S^'HtuiuH  ol'  Uyniioology  and  Obmoini?!..  iii  Ti-cbIim>b  by  Amorican 
Authors.  QyaMalogjoliKtIiiT.MAT-riiEwD.  MjkXK.  A.M^M.D^rnnrawtofObctslna 
■ul  UrnMoloxr  la  Ui«  Jt«ti^ul  l.Vimrtiiimt  of  t)i4'  (jDiTtniij  of  BuflUo;  Mild  OlwCM- 
rhs  Mii«l  \ijr  Bastox  (.Vmkk  Ilinn',  M,  D,,  A«ociai«  I'rnfasMr  ot  Obttetric*  in  ih« 
(jnlfvnllv  ol  rmwjrlvnniti,  I'hUaiielplita.  In  fMir  rery  handaoiii* ocUro  TotiiiUMi,  tea- 
talnloK  :^>M  vngM,  1092  cnftntvingii  nnd  8  plates.  Cosiiplol*  irorh  ••■  rtadf.  IVr  vol- 
une:  7:iolli,  iS-OO:  tcMlicr.  t'iM<;  h»\t  Ruw!»,  t^.Ott  Pitr  mU  hf  tuAKn^um  onlf. 
iMrat  lA*  P^M^t.  f'tll  ilnoriiitivr  pirrulor  fnv  on  applinliou. 
LIST  or  CONTIIIDUTORS, 
irit.l.lAM  K  n^KliB,  H.  V, 
ROOKKT  HATIKC,  M  I'., 
I  UMCKL.  C.  I»t  ■<KT,  M.  I), 
JAUKH  C  CitMKiCl>K  ».  Iv, 
I  HKNHV  C.  CuiK.  A  Jl_  M.  D, 


RlXVAIIU  C.  liiVlB,  Ml'- 
iG    K.  !•■  ti(niWKIMIZ.ll   t'., 
E.  C.   iJllI.'l  K^      »     I'     M    P,. 
B   WrK.  FV 
liKxH'-h  I  .SS,M-  P, 

UEMIT  J    u ..  :.s.  A   M.,N.  Dh, 

WILLIAM  0^>1>ELU  A.  M  .  M.  [■.. 
BllRKKT  H.  OKASI'lX,  A.  M,  M.  D., 

1  ri,, 

■  II. 

i-     ■  ■■     .      I..M.B- 

\.  mZv-  IX, 

KIiWAbi)  W.  JKNKb.  M   P  .  LU  tl. 

_jiliuat  ■(•nltcmiacC  lli)>  founirx  li>  il>m  d*' 
paruaenuonltDpKdBaslOQ-  Kw? hooT1trl^^la^p^P' 
I•M■■  iB«Basn>|>h  uf»B  hbaparlkl  Mpla.  mi^i 
•TnyWIaa  id  Ihr  tnj  dC  IiUMit.  Ui»rT.  mBlhoJu. 
■d4  mnlti  If  nrnvowil  lo  our  nttlHl  nwH.  A>  ■ 
•«rt  alt*n»n!l  rah  no  m,  ll  Mtl  tw  (Mind  rMnnk*- 
MylUII  knd  iBiiriictlts  In  •t*ry  dLnrUoo  W 
tDqatrj.— Tm  r>MMn<OaHtl',H*|<Minb*T,  IW 

Than  (kD  Iw  tiut  lllilo  ilniibl  u.u  Uil*  •mtfc  will 
•sdlhaMHic  (>iat  wlUi  lb^  |iror»«lon  llut  Iih 
la>D  aroimlfd  U  lh«  "fiyawm  ot  HsdIelDa  by 
Amtniui  Aatlion,"  aud  ih*  "8T*(*m  ot  Of om«1- 

XbyAnivrlcaii  AuiViorH.**  Onvlt»iitliM«loka<Ftt 
I  loAay  <if  ihii  rolunir.  I'>t  r>u  iiiM  Jail  and 
marlMil  pfalw  mi]>t<>  ml-ti>k*a  (or  flailaty.  Tba 
f0»noll>n.  Enjittinann,  M»nln,  lllnl,Jii|sard 
•■4  B«a*«  ara  lawmpanbljr  l«]rODd  anjUIDa  ihM 
(■Bbafouad  la  ubaWtrieal  HAdU.  C^rtttnrriba 
EdHor  mar  b*  coofiKlulawd  tar  laif  ag  mirJa  aueb 
a  viH  wlBMlnn  nl  hi*  matrlbuwn.— JMnml  qf 
UUiHrwar  Jlfal«*l.lMtM«i^,Snl.fiMI. 

la  em  kAIm  of  Uia  "eyMaBi  ot  rraallcal  H«dl> 
•iMlv  Aaitrkan  A<iibon,*<i«  mada  <ha  follciii- 
iBg  aUMniabd— "It  I*  •  wntk  ot  vblPh  Ih*  pIO- 


HOWARD  A.  XRLLT.  K  !>., 
I'HAKI.Ktt  lUIIKIII.I.  I.KK.N.Pw 
WILLIAM  T.  t.rSK.N.  I'.LL.  D, 
J.  )IE\LiItlE  LL'lTlJ,  Jl   f>, 
JCATTflKW  !■  »IA^ V  A.  M,  M- D, 
H    Nf.u'Kl.L  HAwnS.  r.  ft.  B.,  fl.  0- 
KICIIAIU'  IV  HAl'KT,  M.  U., 
V.  l>.  PALMKR,  H.  D.. 
HOSUEM,  P*hK,  M,  tl,. 
THE-'l'lirl  r>  CAIlVtIt,  M.  IX.  LU  Di, 
K.  A    K    I't-MlueK,  M.  K,  i.L  U. 
THAIH'Kl-S  A-  BIUMT.  A.  M,  M.  IK, 
J.  C  REEVE,  M-D- 
A.  li.  Kuc-KWKLUA  «.>!.  D.. 
ALSXAKUKR  J   r  CKKKK.  ».  IK, 
J.  LEirtBBHITH.  »   II, 
STBPHEK  SMITH. U.I>^ 
It.  aTA.SORL'HI   HtlTT>>!(,M-D>LI^IX. 
T.  OAlLLAKli  TItUMAIL  M.  !>.,  U.  D, 
ELT  VAK  PE  WARKKR,  M.  I'. 
W.  OILL  WTLIE,  «,  D. 
faul-iti  In  (liU  roiiKtrT  nk  (tal  prnutt.     VrMlaa 
•xrliuliafi  by  AniarlPaa  i^iytlalwu  ob*  •>*  a» 
«iiUDl*d  slili  all  iha  rvlaitM  it  allinaw  M  lb* 
Coliad  8ma».  ih*  obanswr  of  lb*  •oil,  lb*  mao- 
oara  aMd  rmioma  (4  ik*  p**fil*,al&.  It  li  iHmil- 
latljF  adafitnl  hi  lbs  iraAU  nf  ADMrlcaa  pni'iMaD- 
•»«(  in«>l(PlB*,aBdI>HainatuB»Ui*l  xarjruia 
at  IbeiD  HiNitil  dadn  (o  hai*  IL~     Ktary  w-rd 
lhu>  axiiniiMd  In  rMwd  Ia  Ui*  •'AnarHMi  ^a- 
lam  at  I'neU'-al  McJlela*"  la  aiqJIoabto  (a  Ota 
■■jnarm  ot  uroBnlou  by  Amarloa  Autbora.' 
II,  Ilka  tba  Dtnar.  luu  baon  vtlupn  •loluMraly 

KAmoili'aD  fhyalGlaaivtMBnaoquaiDMd  ■llli 
lb*  HiarvunaUc*  at  Asaf lean  peaiJa.  alia  ■!• 
■oil  ■•toinied  in  n-Kkii  lu  iba  paaullwllloa  of 
Amari«an  iriiaian,  Uirir  maimtra. <«»b>ma. tmsiw 
ot  IWInc  aW.  A*  rr»r]i  I'racUtiac  iihyilalan  la 
oaJlad  Dpon  lo  Ifaal  UtHuai  ot  frmal**,  and  a* 
(bay  (ciDvltlDM  a  fla->  lu  ahlcb  Ilia  Aaillr  phy- 
■Irtan  muat  fli*  alMouon.  anil  CMitioi  uu>  otat 
Id  a  apaelallM,  «■  da  BM  kno*  (4  a  aotli  to  any 
dapan»af>(  of  nadlclBe  lba<  n  ikould  MaitaoKly 
taeaniM»Dd  raadkal  oiao  eanoMly  uutvliaalua.— 
Oacpnali  Wtd.  VaaiJuly.ltn. 


THOMAS,  T.  GAILLARI),  and  MVND±,  PAVL  F., 

M.  ».,  LL.  n.,  Jl.  D.f 

firrftutrif  DUmtm  tf  f—^  •<  <«•  CM1<«<  /Vi^biid-  ^  Oyaiaabn  In  li*  X(«   rorl 

APraotioml  Trcntfno  on  tbe  Dlseaass  of  WemoD.  New  (tUth)  edttUm, 
UMnMghlT  wvbcil  in'l  tpwrhlon  by  Dh.  Mtxdk.  In  one  laixo  nnd  baiidioBia  pctaTo 
volume  of  aboiitMN)  (AM*,  vitfa  om- 300  illiHUBllaaa.    Stad^  tl^ilf. 

Tnt.  TiioKAlf  ■Unifatd  weak  En  the  origfawl  lest  ami  Iiy  tu  (nnclatinna  inlo  rthtt 


bjiSiitgai  la  aTMyiftieiw  rcRotdcd  w  tbe  b«t  wpiawiMaliTW  of  Uic  peculioj ly  AniaricaB 
■d«K*orKrDecni<^.  Ill  iliia  nrinon  tiMjofnt  aiiihon  bat*  owWrtakaa  M  nrtMm  ib» 
fnctlcal  nturr  nf  ibe  wnrk  wLkli  hu  rmil«r«d  il  ao  uwflil  (anadcnta  anf  pli7«kiaal, 


■dcncvorKmecn^iy.    Iii  iliia  nrinon  llMjofnt  aiiihon  bat*  nadtrtakan  M  i 
fnctlcal  mturr  nf  ibe  wnrk  wLkli  hu  nf>il«r«d  il  ao  uwflil  (anadcnta  aail  . 
and  alia  to  bring  it  alimU  wilb  tli«  btat  ^yDetotoffial  vi«w«  anil  pneticc  of  Ibo'  prcacal 
^j.    He  ihorni^  rliarnrl^r  of  ibt  TOTiBon  mn  l-o  iimWritixiil  fniio  lb*  fart  Ihal  t4  Iba 
itluHnUDiii  nno  litimlTttl  and  KTCnIT-lti-o  an.'  ii*w. 


EDIS,  ARTHUR  IF.,  Jf.  !>.,  ZotmI.^  f.B^CJ*..  M.Jt.C,8^ 

J>n>f    'ifrirtiii    rHimialll  In  ViiKInai  Ifniitfil   Iilfl  r>)iiriai  tl  ffilWl^  f|lla>ai  HaiBlllit 

The  Dittoaaoa  of  Women.  Indndinic  U>*ir  Patbokcr,  OauHUon,  tiiiiin*iiiin 
DiatpioMi  aifcl  TraitmcDL  A  Mnniuil  Gw  Stiidmu  aad  PnctltMiMa.  In  one  liBBilaaraa 
ocuvo  Toliiinii  ot  5Tii  riu{«i,  wilh  148  UliBtnUlmK.    Uolb,  fSJW;  ImUivt,  HOD. 

Tba  tfamliJ  qoallilH  olilrt:  ara  ooniidtnMnia 
■ra  iboNniRbaaaa  lo  ootarlni  t^•  «hula  ipwiiid. 
plnaraau  ut  daiwrlHIo"  "'■  midlwnaM  oi  rtaia 
DMM.  AooUiaT  nurlied  Iraliu*  Ot  iba  bosk  U 
Iha  *«lanilio  palil  to  tba  ilatalla  t4  any  mlDOt 
avflnl    opprallon*    aad    fasotdaiaa,    it.  tar 


teaSBoa.  Ib'a  oib  ot  Mata  BM««llon  «f  laaobaa, 
~     a*ar  lolaeUaiiih     TMaa 


•nont    tb 
maot,  ud 


tba  noiv  «aaiBwB  mMbada  «t   traat. 


maot,' aad  ya<  Ta<7  Uttta  t>  aald  abaiu  ibalD  la 
many  of  (M  taibtoaka.  Tba  booh  la  ooa  to  to 
wwnl*  ratonif  dad  tafai^aily  lo  aladaau  aad 


praenilafian,  vho  oaail  a  aiocIh  to)  «i«i. 
plalar«wa^otUia*bala>ali}fVL    SpceitlMMoab 


wUt  a»d  many  uaahl  blow  lo  Ha  , 
X*£  and  Svy.  Jaom,  MaMb  ^  INML 


26 


Lu  BftorHUB  &  Co.'a  Pdbuoatiomb— IHb.  ol' Wobmoi,  UMwt}. 


£JCjir£T,  THOMAS  ADDJS,  JH.  D.,  LL*  1>., 

The  PriDolplw  and  Praotloe  of  GTiwoolocr  i  FortlMtiMoifattidMUi 
Pnetitioaeno/  Ueilldae.  Nn>  (third)  edlilan,  tboroufhlj  rvrlaad.  In  uo*  l«rn«id  f 
butdaome  octara  volume  ct  660  jNgoL  witfa  160  Ulortntiuoi.  Clulb,|6{  UallurJ 
*tr7  haadacnw  hitU  BumU,  niMd  bandi,  f&M. 

W*  m  hi  doubt  whHhcr  i«  mnirwalue  ths ,  Iba  prlrllMI*  *>>■■  «ShM  Umoi  •!  rMadaa  ife* 
■uUiar  nor*  than  III*  prefmioa  ii|>«n  ih*  *pp*M-    tlBnwt>lpmpitM«(iA«wun<H.    Hm  wnwlANi 

aiMof  iha  Uilntt-llUoDirf  ml*  w*ll-kBoirniir«'k.  l«l  ^tV«M  *B<  oaaWtooMMMntH    ir*  iki&lhal 
nM]PUw.MII<lwa,t)>*  Ilf^l<inie(p»fli<n'-i'n(    fI>|ltHna4  talyhli  MlvMn*!  ■iiwrUn 

«M  «b«lkHCOI»piiniinu>]r4bt[uitulUioil  i <         <     <i<-Mi>n  tp  nfnnagi  IM  ill  lint  »»M*  < 

■*  •  laid  Md  raefMnk)  ap*rmi"r,  uu.L  »  :  <ela*l  (tlMM  «Ml  UL— ii4M*  .  ~ 

dtlDIW)  M  miMh   ■UcaUOO    InWa    Kiicrui'.  <  ,  UUP  U^  U& 

MIibiwUm  pnlWinu  vtll  DdiSilJio  ftpiin^itle. 


>  of  inv 


XJJT,  LAWSOy,  F.Jt.  C.8., 

Prtfttmr  of  Onarctuav  »>  Qkmh'i  CMhtM,  JIf  iii|>i|  lot*  JVirtiwI  xf  Ik*  A-MM  0*«r 

DtMMOB  of  Women  and  Abdomioal  flurgor.  ta  two  mr  luMHtMot 
octATO  TolutMs.  Voliune  I.,  6M  pag«^  tfZ  «iigni*ingi  iM  3  pUlM^  Cloth,  f3.  <V<w 
Norfy.     Voliiiii*  II.,  prtparing, 

Th*  alw  «( 1^  »rk  doM  aoi  IndloM*  lb*  r*(tt- 
I V  »yii»Mir>  <rf  ■  tKil  teok,  Mid  7*1  B*wlr  tniT- 
UilO(*tdlHMe  lanatBlos  to  Ih*  tiiHom  arai*> 
■BMrnaftbir  canM4*nllte.  Tho  dwOtpUoncf 
dWMni  «aD4ltlsu  I*  axondlnilr  diMr,  mJ  th* 
tnaUn^Dl,  ni(<dlcitt«rrariH'«I.M  nry  MlUMletj. 


MiMti  or  tbs  Mil  If  atnarin-i'*-  ' 
rau*,  wblcli  (dd  niacin*' 
|^•  tuM**>*d  fi»a*  ft  ir*>i 
B^M  llial  r»  KTHMttcliid  '  1  . 
tut  la  Mtr*  Ilia  wnrk   la  UibU 
(AtMrM  V«"l'.  M>r<ib.  Uaa 


,> -.,  (lU 

libnnaa.— na 


DAVENPORT,  F.  H.,  M.  D., 

DiMasM  of  Woman,  a  Kimual  of  Non-8ui-gioal  OyoKcolosT-  D*- 
dciwd  MpaclAlly  for  ths  Um  of  SlodMila  unI  G«imc*I  Prtctltlociare.  In  on*  SaatlwM 
ISIDO.  tdume  M  317  [«ge»,  wilb  lOS  illiMnUkog.    Cluth,  fl.SO. 

Wa  ajpwa  «fiii  iti*  aaaf  M*l9«*t*  obnta  a»  '  S**«IMac  !•  of  ih*  im*o*(,  (raaban  aad  noai 

tlo*>aonBrat*adIao(harJ<nirDalieoD| "    ~     '    ------  '-■  - 

Dr.   ittnuforl    an    Ilia   MJOaa   whlol 

■lulnad.    lis  hu  irMd  u  «ttla  a  book  (or  lb*  author 

ffiidtnt  and    ((orral    praeilitoot*  Hhkli  vonld 


leoDcrMuUillai; ,  uwiuMt,  •«  niu«h  m  that  w«  hara  weonnnwidtd 
whloh   ha   haa    lllaow  dowaf  K]roaMla«y  aUVMuUi.    TbalUw 
adTlMi  '     " 


Mil  ihem  >uii  sliai  Ihar  oURht  to  liao*  wllbaal 
dIttiacUBB  ihair  altaDllan  allh  alM«f  onaplla- 
llan*  for  ahlrh  iber  fould  bara  ao  (MMalbla  ua*. 
In  IhU  ha  b—  bun  am  inanity  lutVutOL  Thar* 
b  &M    *f*ti   a   p4ni|raph   of    UMlaia    BMMc. 


Mt  Is  llM  wwr  el  uwMieani  Iim  all 

baea  BnKtIeallr  M*te4  br  htaacll;  asil  ■■cb 
■nthou  racalia*  onl^  n  BMiah  aoamMMaUoa  ai  ba 
kaa  fanod  Itac  It  daawTaa.  W«  w«  aara  lUi 
ihaM  «o4  aaalhlifa  nlll  onnMafiil  lltr  11  •  laraa 
tala—OMda  IMtml  llMord,  Da«.  UW. 


MATf   CBAHLES  H.,  M.  D., 

A  Haaual  of  thoDlaeaaM  of  WomSD.  Balm  *  amOm  »bi1  truanutki  txf»- 

rition  of  the  Uiaorr  anJ  practica  of  gjoeoJIiigy.  Kmr  (3>l)  editioo,  «lttM  17  L  8.  lum, 
iL  D.,  AHaodinK  OjoMnlwIit  at  iha  Hiirlatn  Hotpitol.  N.  Y.  In  mm  ttmoi.  voluna  « 
SOO  pagw,  iritli  31  illuainttOK    Clotli,  tL.TS.    J«H  raady. 

r«pMI]r  bal  bu  aet  ika  Una  la  •nuaali  Ur«ar 
iMtkik  Wa  ara  niiub  MnMk  vKk  Iha  raMlaaaa 
Bkd  owianiaoea  vlUi  wblsh  «*a  an  rvhr  m  aar 
«uHaM  ruBiaload  In  ikit  Tolnna  CiaraAitly  aoB- 
Mtad  indaiaa  and  anfta  lllMimlaaa  abwaarMll 
Uie •orK.   TblBMaawl «iu  bajMikU tuMii Ma 

SUfMMa  Tarr  aaililiaMorUr.— fka  nyittHM  1 
urytM^JBaa'HML  ^^ 


Tbla  la  a  manual  t4  cKnatfolocf  in  a  very  cQiH 
4>wa4  fonn,  ^uil  iFim  Cii-i  ilitl  •  >SMnd  adllta* 
kaabaanotlfxl  (i>r  iiiili'--ii*>  ihut  11  hu  oMtirilb 
a  (il*«nbla  m.<>i.ilon.  It  I>  lut*n>lfd.llM»uihor 
talla  mt.  lA  Bid  lb*  MOdanl  who  aflat  bavbac  car*- 
Ibilv  p*rua*dlarKar  oock*  daaira*  to  rarlao  Iha 
•nl4at<,andliaa4d*th>u  Unayba  u*>M  10  iba 
finoiUloaar  i>h«  wlihaa  to  latraab  kit  atanoijr 


DVSCAy,  J.  ytATruEWSt  m.d.,  ll.  d.,  f.  r.  s.  e., 

OUnicoI  LecturtiM  on  tho  Dia«aMa  of  Women;  l)«tir«t«il   in  BaiM  B«r> 
ibolMuvir'i  ItcMpilal.     Inona  liuiilMnM  oclaTD  voliune uf  IT&pogM.    Cloth,  |I.S(X 

Ttaay  ar*  in  'tDiy  oay  •vnlir  of  Ihsir  Butbvr: 
la>t*ad,  ■■  k«k  ups«  than  a*  amonK  Iba  aaaat 


nloable  tt  hi*  canuflnUoBiL  .   _ 

mallan  ofcrtal  lotaraal  10  Ihaaananl  prvlli 


Thay  va  all  uaoo 
n  of  Krtal  lotaraal  10  Ihaaananl  prvllUonar. 
oribiimd*Bl«ltbMJb]*ola  ihaiara  na^ua 


riila,  Bda«uiit*4r  baadlad  la  Vtm  laKt-luaka ; 
of  itiaoii  abu*  baariBK  upon  inpln>  Dial  ara  t 


IftMaaof  Bl  lannli  la  iiirii  •"(k<.  yi  l>ar  1 
of  iBdlrCtMUlj  inai  mer  da»m 
IMl— X  r.  JTadwW  .bHniaJ,  H«r<^  I 


HOIKliE  OK  IX8IMH  MtCVLlARTO  WOMKK. 
lBt>*dla«  iilaptieainantaoriba  UwfiM.  iiaoand 
•Lilian,  tVTitad  and  aalarMd     In  oaa  baaau- 

Inllr  ..r."i»i  r.-(  =  m  ..,iiim.  .,f  111  t>a««^  wlik 

rUi.  .■.-..:.,..,  i.-l'JlXK     .IM» 

&t;iK>i:itV.  lu  rcltcauua  iv  Um  Proeaw  «< 
Fanuiillen.  A  Daw  anJ  aalarBtd  adUlon,  thor- 
OUaUy  nti»ti*  tn  Itia  liithnr.  Wtih  adqllUtM 
bfV.  V.  Sutoo,  H.  t>  ,Vi«(awM  «tUM«WM. 


alf..tatha  UBlntm  Madleal  rvdlaga  af  pbd^ 
datvMa  In  ana  Ibth  and  tkAn4*dnia  liar«ri^ 
oMBto  nlaoia  of  nil  i«t|«i.  ami  n«  full  paa* 
rliUa*wi4«  «om1«<ii*  ' '.  I'l"  i--ii.«n(alaka«I» 
all  aurly  aootiaauiir  -iiraasly  biaaJ 

In  laubwr.  vlth  fai^.   . 
W»rrit   UKCTt^'Ilt;'!  <      _  MRBAHM  Vt 

WOUEX  Third  Ainaili'iA  i/voa  Ih*  third  La*- 
■liaadllkia.  In  una oMara Toliuna  of  M1M«& 
C'lol^.  t*.'y.  laMltar,  HTl. 


Lba  Bkqtuxks  a  Co.'S  Pdbucations — Midwifery. 


PASmr.  THEOPHILV8,  M.  D.,  LL.  J>., 

The  Soienoo  ftud  Art  of  Obttetrioe.    Nev  (2il)  dlittoa.    lo  on*  hudmn* 


TlMMieaad*dltliiaotltiliiin]rlII>rullr  uptotbaiabMnrkllurMoneu  ta  tnikd  kooik  ■bkli  Ik 
MHntdaUor  adnDDMiwal  ct  ()i*  obaUtrle  aiL  1  te  BompnhanidH  nod  j*Keamf*Bi  wx)  |iriHil<>*L 
Tb*  wMlwr  hM  *oc<>**ilfd  *u*«<dlii(>]r  aptl  Ib  '  In  ■tn^h  iw>p>i^  Ici>h»«ImM|'bhii  bank  »rihv 

flni  mritt     Tn*  Inalngiil  ofth*  (UliiMUilmi 


tothor  hM  *oc<>**ilfd  *u*«<dlii(>]r  aptl  Ib 
iBMtvoiulDK  nSK  msltcr  •Uhniil  wpurvDIljr  Id- 


MMMhK  LbBsiM  of  kl>  oork  oi  iDUrfviluR  with    »■)  lATas  lo  ilia  v««— Uia  laillrliliiallitM  u(k 
IbaMnoDlliaua  ud  EntrsoriUlltaiHy '"'"'riiti-    T<raciji.-iil  trvtiK.  •  ikllnil  ebaWirMtiU.  •  siM* 
ifii  -     - .  .  .       .  —  .      .  _ 


Uao.  II*  I*  ftf  Itlfctuniw  In  hU  d*ii'r)|>t'BOi<  of 
(Midllloos.  ud  pKii**  hiTnMlt  tn  (nl*  f«*tw«4ii 
■ckalif  ksd  ■  UMtM.    bnly  tn  tb*  nsg*  of 


ililnk*ruid  *  rl»  •cbatu'.— JV*dual  Sio"i.)Ut. 
IT,  inl. 


PLATFJJlt,  IF.  8.,  M.  ».,  P.  »,  C.  P., 

^ t/tnar of  OftiJiing  Jf ilnwM m  AW'  OiKiji,  Lon^n,Ut. 

A  Treatise  on  tho  Scionoo  vnd  Prvctico  of  Hidnriforr.  Ne«  (GAb) 
AmxHiiin.  fnjriilli»t»vv(ith  Kniiliah  rdiiioii,  Edilol.  "illi  u.iililiuii-,  liv  Robert  P.  H*b- 
mxi,  M.  X>.  la  on*  \>am\if>%n«  [k-ioto  votiimc  of  M4  |m{[».  wiUt  207  tngnvingi  aod  & 
pUto.    aolh,  14.00;  Icmhvr,  £3.00. 

TruTy  *  wnndcrful  tio'>>L:  ad  ppllom*  of  all  ib  '  linn  frtini  th*  ni'tniaai  cT  tfonwitlun  to  ih*  II  nM 
•IMriMl  lisri*l>d|ir.  full,  elMT  add  morlir.  lo ,  u(  eomr'oM  latuluUoo  liM  hwl  tha  •ulhnt'a 
Ihlnrta  r**'<  *<  ha*  R-a'had  HTrD  vdltlwik  11 .  t>iUI*nl  allBDtloD.  Tlia  plaU*  and  lllualnlluDa, 
UpMhapa  IK*  (n«ti  inpularmrk  of  li*  kindvnt  nan-rvIlT  ntuilttd.Ktli  ivvh  it>*  rei*vti*  at  mid- 
prill  nl* J  In  Ibr  pronHlon,  BBilnaliis  «l()i  In*  otforr.  Tha  milaraf  tTilsbnok  «tll  hat*  btifM* 
— alriri]'  and  phynioIuKy  of  ihacrmuaeeauwrDed, '  him  ih*  »ry  IMHland  t«>t  uf  olsuulc  pnOlMy 
MUilst  !■  l*n  iioafltMa  that  Ui*  prastuta)  ae- 1  and  alaa  of  all  <h*  nolni'ldsnl  IrouMa*  mODaoUd 
«MOli*ar  ihnnid  kfiQ*.  It  loma  that  •nrv  tbarawltb.— SSuMm  JVoditivMr,  Uao.  un. 
•Ivkbla  phralolDBloal  or  ptthologlcal  taodI>  I 


Kiya,  A.  F.  A.,  M.  D., 

IV'Jutur  r/ f3t*lilritt  mil  AuMwaqf  Vmmkm  Ot  MttiaU  Dtparitnml  of  a<  ai—iWan  r/a4*(r> 
•uy,  H'oiAinfliH.  A  (l,«idto(ki  Danwkly  of  r>niimt.<H. 

A  Uknual  of  ObKtetriua.    Ne«  (ronrlh)  edition.    la  mm  i*rj  handiDaie  12mo. 
Tolutnw  of  4:i'j  |iH|(tK  Willi  UO  illiiMTAiiniu^    Cloth, (2.&0. 

K>r.  Rliig.  In  Th«  pr*<fjK<*  ta  (h*  Drat  tdltlon  af  I  (1)*  daapflnrl'in  or  labnr,  hnlh  normal  aiid  abnor- 
IhUmuiuI.  in'j<l<»ily  ilalH  Ihat  "Hi  purpota  I*  ,  mkl,  thai  Ur.  KlDt  Laa>  hlalwM.  Har*  hit  alTt* 
10  buDlali  a  (Vud  KiifU-ndwork  la  th*  iiiijaat  al  i  ta  au  (unnUa,  anJ  iha  Uliuttaiiuna  ara  an  itnM, 
th* ttaclBotoi nf  hiaotawirlc  nuiliaa."  lu  pur-  (hat  ih*  **ri**ilrraeould  nollulli<>r*ci*tt*aolM( 
foa*  laatMlxdi  H  iMU  firniih  ■  i^wd  (toaDd-  eoDMplIno  of  Ubor,  til  MnpttFillnia  and  lr*a^ 
oaritlo  ihe  (ludafll  aim  '^arftuUj  laada  ir:  and  mant.  Ot  Iha  111  lUualralioua  li  mar  ba  aatti* 
*    "         ~     '  >aij  ihai  <hay  atliltkufraitianditiatlhaaaKtmHri 


fUftliar.  iba  tiu^y  pruriliLuniT  thfiiiid  b^i  tc^-tn  ihi 
folam*  i^raii**  wrlrian  tor  »i4idaf]i>,**  ii  •-i^tt- 
lala*  mucli  Ttluabtc  Qlwwi/ta  koowladi*.  piin* 
•f  which  la  DM  (bund  In  rjora  alaboraia  laii- 
Moka.  Tha  chaiilan  ou  Iha  anatumr  ur  ih* 
fctnala  ^namtlr*  orgaua,  in*ni*lnja1lon,  frviiuda- 


[■Mli^  ^uvia««««  Ilia*"',  ■■■«iiri4*jaiiuM, 

IND,  th*  atria  or  prtRnanrr,  and  iha  dlaaaaaa  of   oal  Htut,  Dta.  T,  UN. 
fMfMOey, an  ail  aiotlltDiand  elcat;  built  la  In 


wnrk  !■  aicaflani.  Tha  oam*  or  1A*  puhllaiiara 
L*  a  auffl«ifDt  |u*nnt*«  thai  Ih*  aork  U  pia- 
Hnied  la  an  afliractlTa  forni.  and  fpotn  *«a*j 
■laDdfMlDt  *•«»  noai  haanlly  lacununasd  Ik* 
buuk  bslh  loptartlilonaiBod  •tudaol.— TM  JfaM- 


BAJeyss,  ROBERT,  M.  />..  and   FA2fCOVBT,  M.  2>., 

Mw.  u>  iKt  aawrol  l^tft*  JfMDs  1<<«A  Obidfru  Pla,,.  ta  SL  T»»wm'  Btty^  Lam*. 

A  Sjretem  of  Obatetiio  Hadiotoe  end  Surgery,  TbooreUcal  uid  CUn- 
tokl.    For  Ilia  Sitiilmt  •ml  llie  Prartltic«i«r.    Ti\»  Nartiuii  «n  RinbrrttlacT  br  Prof.  lliloM 

aotE.t6:  k-aih«T,|fl. 


Mm«1wU. 
TM  Imniadlala  puti»iaa(il>a  work  l>  lo  (litoiah 

^haDdbo•k  nf  ohaU'irli'  in^dioiBa  and  auraary 
tiha  IIM  ol  Ih*  aiuilrni  anil  praiTi  lUoiMr.  ll  It 
Dot  an  a.t4K]i|Brsilon  lu  >*v  of  iha  l^ak  mat  It  li 
Ika  baal  Inalti*  la  Ih*  Rnglli-h  laacuac*  )-at 
pubilahatl,  and  ihla  irlll  noi  b*  aatirprtia  lo  ilto«* 
«te  ar*  Ki|iialoiFd  allh  Uw  vork  at  th*  aldar 
Banw.     Eiarr  praclUlooar  aha  d«ttaa  M  ban 


In  one  8to.  voliime  of  873  ppL,  with  S31  illiulf>tii)Tu. 

Ui*  b**l  olxWtrlral  spfolona  of  th*  (Ima  In  • 
raadKjp  aooaaalM*  and^ooiidraaad  fOfin.  onihl  lo 
nvnaaopjaf  tha  bMH.— >/*unH'  rt  tkt  imirta»n 
Mtitaii  iMDoaUaa,  Juna  It,  ina. 

Tha  Authon  har«  ■■  It  a  laivkook  wtikh  l>  la 
ann  a'a*  qntl*  mrlliy  In  Uka  a  ala^  haald*  lb* 
l*at  irMtlaa*  «C  Dm  »ano4^.TM  Toik  JMMal 
Jutnal,  itOj  X  UT- 


F. 


WiyCKICL, 

A  Comploto  TreatiM  on  the  Patbolosy  asd  Trvatmesl  of  CbildtMd, 
For  BUuUaU  and  PnditHjiwni.  TrvotUial,  wilir  tha  oiMMnl  ot  iJia  Antbur,  froa  th* 
■MxadGcnnaaeiliUui,  l>T  J.  K.CfiAi>wicK,  M.  D.    OcUfo «H  pag«a.    Clall^HOa. 


ASaWKLL-a  PIUCTICAL  TRBATiaK  OX  TRK 
DMCAtas  rSCULIAK  TO  WOMIUt.  ThlKl 
AsMtae  bom  tba  tkM  and  iwna«l  Laadaa 
•dWan.     lDOBaan>.M.v^MDL    CiMh.  CUO. 

PARSr  ON  SrnUrOTRRIMK  PBnr.XANirr: 
lia  ClUIOil  1(liMf7,  [ilacnoilr,  l>ii)cn<»t>  Bi,>l 
Traanaaw.   (Miati^mraiah    aoiA,t>Ja 


TAniBR  ON  PRBiiNAXCT.     OMara.  4W  | 

nit  and  tlataa^.  I*  «Ma    Ololk.HJi 
OBHaOHILL  on  TBB   prxaPKRAL  rBVKB 

AMD  OTHES  DUKUES  PECULIAR  TO  «•> 

MKN.     Inonarra  ad  nrtMiaan.   ao()i,|tJ>'. 
WRI'MCSTHK  NATt'HK.SI&HaAHPTUAT- 

MSdT  or  CHILIiBBU  PRVBB.    la  Oao  Ira. 

i«)ra*otMIH«aa.    OMh.lUa 


80 


Lka  BaoTBBiu  L  Oo.'b  Pdblioai 


..  Uta.  ChllOu. 


SMITH,  J.  LEWIS,  M.  D,, 

amuM  fvyMc  *t  OuMMi  tf  c»MUf»w  <■  a*  ttm^m  BffMi  juttuu  cwi«t«,  Jr.  r. 
A  Troatiae  on  the  DiM«*M  of  luALnay  uul  Obildhood.    Sew  (mtmuIO 
•dllkm.    ibomuitiljr   nriiwd    uid    r*«rlura.  In  oo*  himbuiiv  ortsvo  volaaM  of  ttl 
p^gM,  witli  Ql  illiMntlon.     Clolh.HW:  l«Mli«r,>&«l,     JtMrtadf. 

IC*wy  4*p>rtDi*Pl  (kaw*  IhM  tl  !•«  bwo  Ilior- 
«achl]r  niwd.  ■nil  Umt  aTMjadiniiuinlMBbHB 
Uk'onrnnfMkdTiiBn  M  kniMiltdn  tobrlnsd 

<aair<*icir<ipio  itiatimM    WhBtiniikH(li**Mk 

tt  Itt.  Smhh  <4  at^a^al  nl«»  li  Uia  ■imdUod  f«lil 
MilMCucHlxand  l^•  nrtAil  daiall  of  IrMUnml. 
(*  Id  UBd(iaM*dlr  ana  a(  ih*  baM  iNaUMii  on 
(klUtH'xIlHuMkWid  us  lati  b«oh  brsuubM 


«r»4  tPiMa  fur  yonnif  BtntlHtoXCT  HhuangrpaiiaiiiL 
— Aif-fu  Jf*rl>«l  ah)  MiralAW   rraniat.  Jan.  ml 

Atn>»l]r  In  r»*lnn>  sllilna*  iha  aniii  of  Dr. 
tiniHIi  nald  puaili»B  UB4H|fliwl  al  <t>r  brad  or  lU 
cteM.  So  bwk  la  any  taiiiiuaf;a  dduIiI  ilwpuu 
•UlttlW«Ult«  lu  praMTilaaaoK  A  lt>(  of  w<irk- 
on  dlaanaaacf  ohllilraa,  inada  up  In  anyrvuMfj, 
•OMldhafa  Uil*irwKi>ilMhn'l,andfaiUa»|iair- 
■ain  «4  Uia  snal  nm/s-nly  c(  practKianan  Ih* 
lM*a■■d^a(«(rlplaI■■  vmhlhMonaalMi*.— diurl- 
M*  rniMMeawaid  .Vw,  Kay  *^  <*•■ . 

Nol««lk«laad[ua  tha  nuny  amlMM  nlama* 
lit  ■■■*•  liroii   [aaiiiM  iMantly  uo  dt*— Jat   of 


<Ail4na,  Uw  watk  (d  Ifr,  J,  Lnt*  BMUh 
hold*  ■  6«*l  •lata.      Im  (BMial  *4IUaa*  ka* 
bran  tftvouidkly  OTliM.     In  fapm— d»w 
ooUM  taal  IKtar  n(  Ui*  i>lia|rt*n  hara  tiaaaj 
llfaly  TwrftlM^      Pull  naUoa  la  Utm  Of  i  " 
raaml  adiwio**  Whi  hat*  haan  nwJaL 
aulbor  MMM  Is  Ih*  •••(»».  Ul4  ■.Waa.afy  ntii 
kMTMiMllvrradMaiaiiBnaMk.  IuUmm 
of  IniMKtllaa  rtwMMd  Uia  WWII  UMy  pr 
na  Mintldand  is  Im««  4aaU«4  fn  lUa^  ( 
eondaDiMbHi   ud   Um  aMlnalaa  nr  all  Ma 
i:.i.'>>fi.i  11^  tulsnia  hat  oM •■•d  tamtarnd  u 
■'•.f-     Maay   illi»mi  »M  prath 
iiai*  noalrtd  apMUl  ahnpwiB. 
Tfry  laaMoal  «»r.     &iia«h)  ran] 
Muu  loktii  IliM  (lia  dLrafUi'b*  lor  tnaUBaal  i 
M  HiUcntarand  tiili.    la  Dooihtr  aotk  »»■ 

*■■  -  •MUIUDllnl 

iiu  iif  l"(anl&-> 


va  pafucantrana  li^^i.    Ja  ooo^rtar 
oafifnl  latucipltod"  gltm  1a  Iha  A* 

S«lana  (Ml  Iha  anlfc-laJ  ImiIIiu 
uWrMl  «<««<  A-rW,  Fall  W( 


LEISUMAy,  WILLIAM,  M.  J>., 

ASyfltonioflCidwiflnT.IncludiiiKtIlo  DiMMUwaof  Prevuoiioyftad tiM 
X^erperat  8tat«,    Frmi-ili  «iiiil«i.    Ocuvo^ 


LAXDIS,  HENRY  G.,  A.  M.,  M.  !>., 

I^tfutartf  Ofiilttrtti  and  lAi  IhMiittiol  Vtmm  aiMaXMp  Jfatinil  Oullat,  O 

The  Kanagemaot  of  IiBbor,  and  of  tho  C>yiQ«-ln  Portod. 
hMidMiM  IZiiKi.  ralniM  of  SM  |HW«n.  *llli  S8  illuMnuiuoL    Clcdh,  $1.76, 

Tha  author  hm  dmitnad  M  plae*  la  Iba  hi»d> 
aftlMyaux  prKUUcaara  hoik  la  ahuk  hf  oui 
■nd  aae>— ry  lnlbr»atluD  In  •>  lulant    A*  fttr 


aam  oan  kh.  naUilu  l>  '<»'iii., 
aonnd.  and  lh«  ^■■caduii'  - 
C>f>lr4/Man  Mr  OmwUAt.' 
Thl«  la  •  baoti  ■■  on 
Tlia  auUiirf  ROH  nnch  i»rts  )<> 
dMall*  of  llM  naaaaamval  ul 
■aat-hoaki,  and   It  as  laaJaMn  i 


''■•  adfloa  it 

■  CWM.     . 

>-,^.m.iaiaa, 

r"  Ul* 

man 

'   I  «>  la 


Maipl  any  asa  wh. 

tba  bD*k  t»  tu 

■uiyana  •  Umi 

anil  IM*  amula^  ' 

lautk  araryihUK 

lyin^'la  laoiu.    ^< 


lyinc'la  laoiu.     ^<  •!  If  li  !■  a*  a 

teaiTM  II  dftnL-.   .  iL>  miun  lu  fm 

«MMffe  *tM«lo»  lu  Biwial— .Vm  Orlaana 
•alabl  AiiMiialJawiiil,  Uat.  KM. 


OITE-y,  EDXVKn.  M.  B.,  E.  E.  C.  &, 

Surglaal  Dlxeasea  of  Children.   In  mw  12bii>.  toIuiiw  of  GV  TWK  ■*)>'■  * 
Cbniiiii>lilliogniiikic  plates  and  86  winkIcuu.     UuUi,  K.     8m  dvia  of  dMMit  JVoaaa^ 


One  In  inim«dtu*4y  alrafk  an  fvadlai  Uik  book 
«lih  ll>  acrmbla  ityla  aad  lh«  aililvnoa  llanaT' 
■bar*  t**«oue<lia  naMloal  fMnlUxtlyot  A* 
aMMr   »II)>    hl>   mtlML      TIm   liaok    nw   ba 


fccoMflty  i*winm*»AM  la  toUi  «*uil««(*  (ad 
prMilile*cn>.  II  I*  fun  of  anuad  lalniinatu^ 
plMMUly  glTaa— 4aMii  ^avfvy,  Hay,  ItM 


STUDE^fTS'  SERrsa  or  MAirVALS. 

AtftMaoT  FHlMaM«a«B]a.A>rllH>Ua*araiUik«l*a>id  VnaUlltmn  gf  lladtM—  Ud  ttUaMT, 
vmita  bytoiiMaiTHDhennr  Ei*i»l>*n,aad  iMUad  la  vwkM-'MaUinafalaniaaalmMMpMHL 
tkhty  IIMHraMd  aod  ai  a  l««  prloo,    Tta  Mlmrlni:  nWuraaa  a»  no«  rMtdvi  TuriaT  jltmM  if  Ai" 

Ootu/*  AirTHM  OH«»a4.  m,  ll«t.n>.>-»  J-1I«AJmk«I  /^AwM,  Ki  Raan^  W" U.«m  ivd  rbni- 

KfiM  (4Ui   •dM(M),|IMi    IVb>>'>  Jfa<»a  /-KinMw  (A  tsfliloii),  |IM  i>t  Iauvmi^ 

Pima'i  AiTpitvl  fWALtoyp.lJ;  aud  Kitta**  Mtmmunt  ffHP>kfa  IMhadiO'  Hia  lcll>wta« 

lilnrnMi    ripna'>n>rM>Mc««b>i-u.    PoiMpafBlanoUmaMa  tndaxaa  UA^a^a. 


SERIES  OF  CLiyiCAL  MANUALS. 

luacnuiRlDi  ra(thl«ft*>(M  II  taaliaan  UiadMlKU  i^f  ili'iutii|in«ratefnirM*th* 

[■Ilanlan  of  aaUK«1lailT«BKiMiKnphion  in>b«tlanl( 

>talunaairllle«aMhi«kaatHil|iMa<aad«llII>aCra«l' 

VMa.     Tlia  rallovlu  miwnaaara  nnit  raanly;      \'ta 

Ik*  ^dat^lLra:  Ouna  *  Kain-a  CMIA^mc  8Mi 

■lia/t*Mu<a<i<,4a<M^  KS;    Niihh  on  Iha    *' 


'jnalbi 
•lpff« 


•iMIVIIk 

Matwm. 


ajH>II*(*l-)n  of  aaUK«1lailT«  BdMipaphi  on  in>b«tlanl  eilnioid  >uMpMa  la'a«feM>  M.  .  ,^ . 

natalunaairlllMaMlo<*aat>M|iMa<aad«llII>aO««lrlItuiinw<jlnruhram»4lttqmaiiiiad«i^ 

i.n»;  irmraiMMM  4»Ml*,aiL%    luuoa 


xAirtin.KX:  irmraiMMM  teMw.|K%  iuu  »a 
JiiMi,  IB;  wax  as  dW^Ml  XMSuM  ^  CMHr*s  K) 
nm    P>ra<«   praMamaaWOMMWiaaZtli   MmnM 


(ha  TWm,  VOi  Tutaaon /aiuiiaal  Otafrinlfi^  |!l  _...._ 
Tin  foUualaK  I*  Ip  MUra  prrparMlou:  Iadu  oB  /aum<j  k^ 
hidai  ««  iMl  MC*.  

OOKI>ir«    MACTir*L   TBEaTIBE   OS   TBKI  WEaTOXSOHl 
DtmUBBaoPCBII.UBKN.    &l>th  adllloa.t*-        OITA  HVHTKM 
n*^  Mid  ■aimautod.    laaoa  tmuo  mtaaaall     Hbh  tdIuibo  "■' 
mpaf«».    Cl««li.tt.t»:lM«hM.«Uft.  \ 


ind  SiTjLaaoB  Nwnduaad  4 
nf  tJu  oraOf^    Win  aapanu 


■    TtD 

I 


Lka  baumaa  A  Co.'8  Fubuvatioxs — Med.  Jiuis.!  Mlscol. 


TIDY,  CHARLES  MBYMOTT,  X.  B.,  F.  C.  &, 

AvIlHNr  at  C\muitra aftt  of  fWr^K  J(«mnt  ant  rMu  SmtllA  at  lit  linftm  fibt^ol,  «lb 

Loeal  Mediolne.  VoufMs  II.  Logitimaqr  ■»<1  Pnernit*,  P1WMIK7,  Abof^ 
llod,  Rapf,  IihImuM  EspoMU*,  SedonVt  BmIkUit,  LJr*  Birth,  Itianticio*.  AspliriU, 
Droitnlng,  HuiKine,  StraifulaUoc^  SBSocaiioa.  Making  a  tmrf  hunlKme  impcriB)  do- 
um  voluine  of  63»  pngM.    Cloth,  •6.00;  tcMiicr,  fl.Oa 

VoLPXK  I.  CoDlAiiitng  604  bnpcrlNJ  ocuwi  paM>,  with  two  buiitiful  mImmI 
|>l»l«.    aotlr,  $«JN;  Imihtr,  rXO. 


I 

\ 


Th*  mU«A9Um  «priM«d  «1tt  Ih*  ant  tantm 
al  Ihln  >arli  I*  tn  do  ■!■•  kaarncd  bf  >  ptniMl  a( 
Iha  •HOB-I  ToluoKi.  W*  ftod  II  fllikraciarlMd  kj 
ttia  Mrina  tula*!*  of  ilslall  aod  dImu-obw  at  ■>■ 
pravbiri  vhlivh  m  hul  orfTMif  to  hlchlf  to  «nn- 
iii*n>l  Id  <iur  fornxt  d<rtlM,atut  ■ltl«li  raodarttaD 
Taiiml-la    ie    Uin  Diedleal   fsrM.      Tlia  ci^ow 


UMn  of  «■■«■  *|ipaDdt4  ID  aMti  dlitaloa  of  111* 
■iitiJMi  muft  hkia  <<Mt  Ui*  auUKr  a  Hodlstona 
■muUBi  nflaiiof  aod  MaMtch,  bill  ihar  OMiauiula 
■'OS  uf  UiB  niaiat  •aluablo  lutun*  01  iha  bosk, 
•apaelallj  for  rahiaao*  la  MadtoD-lacaJ  Irttta.— 
J  awnnio  Jwmif  ^  Ut  JVMlnl  WauM,  A|»ll,  mi 


TAYLOR,  JIjFRED  S.,  M,  D., 

PeiBoiw  in  Bslation  to  Hodiool  Jiuiaprudenco  «nd  Hodiein*.    TUnI 
AmericuL  from  tli*  tbtrU  bimI  rariaed  P^glMh  oJitioii.     In  cine  Uii*  (KUto  tcJuum  of  7M 


By  the  Same  Author. 
A  Manual  of  UediOKl  Jurutprudooco.    RisliUi  Anvrkaiifroni  lb* Moth  LdH' 
den  •ditkin,  ibonniKfal;  rvriatd  ami  r««TiU«a.    Eiljtvil  07  Joiix  J.  ttuai^  M.  D.    In  ooe 
br^  octavo  Toliiiiic 

PEPPMS,  AVOU8TU8  J.,  M.  8^  M.  B,,  F.  JZ.  C.  8,, 


Vorwuia  XAdldiu. 

jWiM  *f  MimmU,  Maw.        

LEA,  HENJRTC.,  LL.  I>. 

Obapiur.H  from  the  RnliKioiia  Htatoir  ot  Spitin.— Coosorshtp  of  the 
PreM.— Uf-BtiOF.  and  lUummati.— The  SademonudAs.— El  Saoio  Hi&o 
de  la  Ouardia.— Brlands  de  Bardaxl.    In  om  12do.  Toltme  o(  5^2  ]>■«'"■ 

CUh,  U..'iU.     JuM  rr.<Jy. 

or  a  fraa-thlnkM.  m*  nodaraUon  doptl*a*  Uia 
loill^iniMit  of  oona  of  lu  lOtM.  TSr  [acta  nai 
Utf  dncaiuaDU^«f  whwhtlia  vuiBttraod  aotoltf 
atiaaiaraUcnlafuillilDn.ara  it»u|Oel  In  liitnlixwa 
onler  and  pnduaa  ea  ih*  nwlxan  *nMt&i|  lt>a 


Tba  width,  da^  and  HwrDncbaau  or  nHacti 
whloh  havo  aaniiad  lit.  Laa  a  W|h  Ibmfrmn  pla» 
aa  lh«  ablHl  hlMctiia  1^  InqnlalMim  ha*  T*t 
fbund  ara  bfra  appllad  toaancMOa-liaaaaof  IMI 
1  iuti)*el.    w*  lian  odI*  to  aaf  o(ibt>  Tolnma 


Afiar  aMaatltalr  r*B<ji((  tkt  work  o»«  d-x*  aot 
hanrtrhaUMtUiaaiiibaclaaOUIialle.al'rMMUiil 


«■■!  iu(>)*el.    w*  lian  ODi*  to  aaf  o(ibl>  TOlnma  onler  and  pndiiaa  ea  ih*  nwlMan  *nMt*JI  lt>a 

nal  li  *nnhll7  c«nplaiB*Bl*  tha  •mIut'*  aarllor  nor*  nnavrlVil  Is  thai  tl  tfami  ika  l*«  dMlKaad. 

Mdl«  la  •Ml*^<aU«*l  hMonr.     Ula  aitaMlta  Wkos  aaaMtaal  liia  aUI*  k*  ia*Tanr  varataal- 

■•d  mlBut*  laarata,  niMh  of  It  bnai  laadUad  laaL  that  II  I*  tiaar,  aotor  and  ar»dlia-no<olliH 

naaiuatlpu  la  MailM^  appaan  oa  **•«;  p*a*^—  ~    -      - 
••ta^alifHity,  Jan  liaf. 


r,  aotor  and  oraolia- no  <o  lull 
)aatla*lo  avothwMoli  r*a*>Ha{haklat>H(  haao 
aa  tboMltMaoI  iha  wiMaraodav  IIif  aialkad«( 
tha  ■»«•»  aehoel  af  bblDry.-AmM  Q^HnM 
d'SM*«r*  M  dt  LttWalun,  PtiU.  J«a.  IWl. 


B7  tbe  same  Antbor. 
SuponitfUOD  and  Faroe  t  Bmys  on  The  Va«er  of  Law,  The  Wacer  of 
Battln,  Tho  Ordeal  andTortur*^    Tllrd  reviwl  and  Fnliirsol  oJiiL-a.    To  one 
ban-lwiiiiu  rv/al  1  SmOi.  Telnma of  A6S  {MgM.    Ckilh,  ILUX 

'  (t^  tha  braadlh  aad  amiiT  of  kl*  rorw^ha* 
BOioni  th«  ntn  *Dimaa  •/kaewladc*.  ilia  |ir»  lit 
■ad  laairarkMaof  hliila**a»nilikMmUiir4  olUi 
(li>R<alUMtBaaia«aaa<aia>laU«a,aa4  hla  warn 
■itvliinaat  to  Uia  eauao  af  IfaadoM  tmd  la>all*«t- 
oti  procnw,— .V.  r.  TV16MW,  Aoiuata^  tin. 


Kr-  t^a'i   •niHniit   blMOrltal   noassrapka,  at 

tiiin  'lO'  nn^ffni'Hl  loipoitaM  li  hara  |md«M4 

Lb  an  »alaic*il  form,  kar*  l>>a*  klm  ■  luUqu* 

Eltloa  amoM  Baaiba  aad  Aaarloaa  mr^tlan. 
la  dlMlocaMMlut  kl*  iMoadllo  aad  alllsMt 
nlat  kla  fovar  cf  oshaaMlTa  hMorlrai  bkbIT' 


B7  the  Same  Author. 
StudiM  in  Church  Hisiory.    Tho  Riw  of  tbo  Temporal  Power— Ben- 
efit of  ClergT— ExoommunioaiioD— The  Early  Church  and  SlaroiT.   8"^ 
and  and  reriaed edition.     In  one  fata)  ticUTo  rakunrioTfllttrank.    C1m1i.S£M. 


Tha  anOiM  la  nalMlaBDily  a  •ckotan  lia  lakaa 
■pararyMffeaiiladittlk  Ika  Wadlac  ibimo  aad 
tofoalionl  toiho  miBiiim  daiall  ■Ubavaalili 
•tfkaMrlBdca  aad  laiMnulllr  ot  tntlmtM  thai 
•ompal  ada'rattoD.  Tha  wi^at «( lafifnulon 
eaaiprBusd  lata  Iba  b«ok  la  ■ilnordlaaiy,  aad 
thBrraFinaollalkwaf  awUMcHlBa  a*d  nbraaoa* 
■aakai  Uw  mrk  isrllf^lMfmluablBio  Ik*  lUMi*! 
whu  daalna  aa  aiktaMIn  raila*  fiWB  w^laal 
aaiinWB.  In  naaihar  alniil*  laliuno  la  Iba  d««loa- 
naatotlk*  pr1n>MnobiuvhlnMad*tlliaoDiuoh 
ilaamBBB  aad  with  ao  jMalla  •  pampllM  of 
Mnplai  or  owtlitlai  ttn*^   JtMii  Trmtlltr, 

Ur.  Laa  ■■  /ttd4  /irttMt  anaoc  Aakartna 
arbolar*  la  Ik*  liMory  «( Ik*  Mlddla  Aca*.  aad, 
lodMd.  wo  haow  ot  •«  Biitofwan  wrllor  wbn  hat 


abon  aoch  1  tu  ttth,  aaaaraiT  and 


^ anh,  aoaaraiT  and  ataaa  la 

lB***Unila«  imaoriaal  «M  oai-of  iha^my  iMm 
ooBiacbdwIlka^UtMRofEaropf  la  die  l(t4> 
<IbAch.-X.  r.Tlma, 

It  I*  •nsar«>r*iM«*>*r«ul  tha  lUit  sdUlna 
at  tkli  «atk  by  Mi.  L*a.  isd  ■»•  towwilra  ■  >d« 
br  It  OB  ua  at  Uio  llai*  b  eonllrate  I9  nvartiMl 
of  tl  In  thia  aaUrffd  aad  li*pf«>ad  brin :  ni>ni«lT. 
that  II  I*  a  hNliaf  (TMH  raaMrOh  an 
full  a(  tarlBd  lafonnMlna  on  rttf  ■ 
akBf  of  (burrik  llflp  aad  hMoiT.     > ' 
rth  anblMt  wHharvwmleataofdMM  aud  lo- 
MMio*>,  B*d  a  caraiUB  aumm 
llanlia  a»4  duikM    ~ 


,  B*d  a  caraiUB  o«a*«MMi*«HW**  it  *art- 
a»4  dUlkM  «r  aalfacMlaa     gd»i*iir»> 


rAIUo'SAauomr 

f  AouiVaa  logntt)  ottht  Utdlal  SttNUM  - 

uin!'.-nii)'"ii<in  i>(  Pnnilcs)  MoKelnr.  ■       U 

-N  I.  uf  IMnilurr      •  ■       **< 

.   .         ■MBt'vraain  .it' 

^.•■••-'j  P<.n' Iff  ■  -^     *l 

IBUOBUwIMnumBEld  ADO*  .Mi» 

iMkiv^tPnntcr^ltHllHnr  ...  IT 
Knua'aoMDt  orSbMMrlE  ■il«dletiia  .  .  » ' 
SrONtoK  on  Kttmtrnf  .  .  .  .  t: 
Blum  ee  hnui  DImuh  .  .  .  .  m 
BHi'aOvatranillivPlinlolofyuid  AD>laai7  ■  •." 
arrnmy'iHiirnfai  Auioaiir  ■  ■  •  * 
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